title: Production and characterization of a monoclonal antibody against the sialidase of Gardnerella vaginalis using a synthetic peptide in a MAP8 format

text: ABSTRACT: Bacterial vaginosis is one of the most frequent vaginal infections. Its main etiological agent is Gardnerella vaginalis, which produces several virulence factors involved in vaginal infection and colonization, in particular, sialidase (SLD), a potential clinical biomarker that participates in immune response modulation and mucus degradation. The main objective of this work was the production and evaluation of a monoclonal antibody against G. vaginalis sialidase and its validation in immunoassays. For immunization of mice, a synthetic multiantigenic peptide was used, and hybridomas were generated. After fusion, hybridomas were evaluated for antibody production and cloned by limited dilution. One clone producing IgG1 was selected and characterized by indirect ELISA, dot blot, and Western blot, and we also tested clinical isolates and HeLa cells infected with G. vaginalis. The results showed that the anti-SLD antibody recognized a single protein of ~90 kDa that correlated with the estimated molecular weight of SLD. In addition, anti-SLD antibody recognized SLD from complete bacteria and from culture supernatants of infected Hela cells. In conclusion, our results showed that the anti-SLD antibody recognized SLD from different sources and could be considered a new tool for the diagnosis of bacterial vaginosis. KEY POINTS: • Anti-sialidase mAb was generated using a synthetic peptide • The mAb recognizes synthetic peptide and intact protein from multiple sources • The antibody was characterized by several immunological methods


title: Managing enduring public health emergencies such as COVID-19: lessons from Uganda Red Cross Society’s Ebola virus disease response operation

text: BACKGROUND: In this piece, we translate insights from our study of routine coordination in the Ebola virus disease response operation by Uganda Red Cross Society (URCS) for managing long-lasting public health emergencies. We further show how these lessons are relevant to the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic. Commonly, emergency response organisations, like the URCS or hospitals, are ill equipped to handle longer lasting emergencies. These emergencies require special measures that combine ad-hoc action, continuous awareness over longer time periods, and the collaboration of multiple actors such as the government, public health institutions and other non-governmental organisations (NGOs). RESULTS: From our study we can translate seven lessons learnt which are important for managing long-term public health emergencies such as pandemics: (1) centralised pooling and management of resources; (2) engagement of local communities in response efforts; (3) the need to continuously recruit and train staff; (4) the establishment of adjusted working patterns to prevent staff exhaustion; (5) cooperation of involved agencies with security for enforcing measures; (6) the revision of funding frameworks; and (7) the use of global positioning system (GPS) data to identify population movement patterns. CONCLUSION: Although still speculative at this stage, we apply these lessons to the current SARS-CoV-2 pandemic. We argue that immediate action in the areas of resource pooling and control over critical resources, in the engagement of trusted and respected individuals in risk communication, in the continuous training and hiring of new staff, and in the appropriation of GPS tracking data is called for in managing SARS-CoV-2 by policy makers, NGOs and other involved agencies.


title: Pneumothorax with Liposuction: Spreading Awareness

text: Complications with liposuction are not uncommon; some of these are very serious and can be life-threatening. In this case report we present a case of pneumothorax following liposuction.


title: Biotechnologie und Umweltschutz

text: Die Belange einer umweltgemäßen Schädlingsbekämpfung führen in zunehmendem Maße zur Suche nach Mikroorganismen, die als Antagonisten gegen sogenannte Schadinsekten eingesetzt werden können oder deren Stoffwechselprodukte sich als neue Wirkstoffe eignen.


COVID-19 and XXI Century Pulmonology: Challenge or Opportunity?()


title: What Is Crisis Leadership?

text: Crisis leadership is a very important part of leading in today’s world. Every organization goes through some form of crisis on a fairly regular basis. This chapter is intended to define what a crisis is and what its impact may be on the organization. Additionally, a distinction between crisis management and crisis leadership will be made and an overview of crisis leadership research will be provided. The Bible provides us guidance on how we should view the various crises we experience. We are told, “For I know the plans I have for you, declares the LORD, plans for welfare and not for evil, to give you a future and a hope” (Jeremiah 29:11, NIV). These words tell us that the Lord already knows the trouble we will have to endure and that we should have faith that we can overcome them. While this is very comforting news, this does not mean that we can sit idly by and hope that things work out. Rather, we are to do as instructed in 1 Peter and in other parts of scripture and serve as leaders and examples for others during tough times.


title: Visualizing Business Process Evolution

text: Literature in business process research has recognized that process execution adjusts dynamically to the environment, both intentionally and unintentionally. This dynamic change of frequently followed actions is called process drift. Existing process drift approaches focus to a great extent on drift point detection, i.e., on points in time when a process execution changes significantly. What is largely neglected by process drift approaches is the identification of temporal dynamics of different clusters of process execution, how they interrelate, and how they change in dominance over time. In this paper, we introduce process evolution analysis (PEA) as a technique that aims to support the exploration of process cluster interrelations over time. This approach builds on and synthesizes existing approaches from the process drift, trace clustering, and process visualization literature. Based on the process evolution analysis, we visualize the interrelation of trace clusters over time for descriptive and prescriptive purposes.


title: Supporting Early Phases of Digital Twin Development with Enterprise Modeling and Capability Management: Requirements from Two Industrial Cases

text: Industry 4.0 is a concept that has attracted much research and development over the last decade. At its core is the need to connect physical devices with their digital representations which essentially means establishing a digital twin. Currently, the technological development of digital twins has gathered much attention while the organizational and business aspects are less investigated. In response, the suitability of enterprise modeling and capability management for the purpose of developing and management of business-driven digital twins has been analyzed. A number of requirements from literature are summarized and two industrial cases have been analyzed for the purpose of investigating how the digital twin initiatives emerge and what forces drive the start of their implementation projects. The findings are discussed with respect to how Enterprise Modeling and the Capability-Driven Development method are able to support the business motivation, design and runtime management of digital twins.


title: Conceptualizing Capability Change

text: Organizations are operating within dynamic environments that present changes, opportunities and threats to which they need to respond by adapting their capabilities. Organizational capabilities can be supported by Information Systems during their design and run-time phases, which often requires the capabilities’ adaptation. Currently, enterprise modeling and capability modeling facilitate the design and analysis of capabilities but improvements regarding capability change can be made. This design science research study introduces a capability change meta-model that will serve as the basis for the development of a method and a supporting tool for capability change. The meta-model is applied to a case study at a Swedish public healthcare organization. This application provides insight on possible opportunities to improve the meta-model in future iterations.


title: Factors Impacting Successful BPMS Adoption and Use: A South African Financial Services Case Study

text: Business Process Management Suites (BPMS) are being adopted in organisations to increase business process agility across a diverse application landscape. Yet many organisations struggle to achieve agile business processes when using a BPMS. This South African financial services case study explains factors found to negatively impact successful BPMS adoption and use. The Alter work system’s framework and the Rosemann and vom Brocke core BPM elements were used as theoretical lenses to understand the case. The paper describes frustrations of an IT team trying to increase process agility with a BPMS in a large legacy application landscape. The main factors driving this frustration were the difficulty of integrating with other applications and staff bypassing design and code approval procedures. The impact of BPM strategy, culture and governance on BPM methods, resourcing and technology is explained. The paper presents an explanatory model which should be useful for practitioners wanting to adopt a BPMS. The BPM literature lacks empirical qualitative case studies and theoretical models and this paper aimed to contribute to both.


title: Non-Functional Requirements Orienting the Development of Socially Responsible Software

text: Nowadays, software is ubiquitous and present in almost everything we buy and use. Artificial intelligence (AI) is becoming prevalent in software products. The use of AI entices consumer inquisitiveness, promising software products that can make our lives easier, productive, and in some mission-critical applications safer. Similar reasoning can be applied to systems exploring Internet of Things, cloud services, and mobile technologies. However, there is a trust deficit when it comes to accepting AI as well as the other above-mentioned features, as a reliable technology platform. This paper argues that the more critical the domain is, the less consumers seem to trust software to make decisions on their behalf or even to be used. Aspects such as safety, privacy, and ethics challenges the perception of trustworthy computing. In the past two decades, several works have suggested that Corporate Social Responsibility (CSR) may play an essential role in creating a trust paradigm between customers and businesses promoting loyalty, customer retention and thus enhancing customer trust and increasing corporate profit. We believe that the software industry will need soon rather than later to encourage trust in their embedded software. A promising approach lies in adapting principles associated with CSR to guide the software development processes. Such an approach could help to achieve two goals: Deliver trustworthy software and, if desired, deliver socially responsible software. We believe that Non-Functional Requirements (NFR) will play a crucial role in this endeavor. This paper highlights a first approach to establishing a basic set of NFRs that should always be carefully considered when developing software, as to aim socially responsible software.


title: Can We Design Software as We Talk?: A Research Idea

text: In the context of digital transformation, speeding up the time-to-market of high-quality software products is a big challenge. Main challenges. Software quality correlates with the success of requirements engineering (RE) sessions. RE sessions demand software analysts to collect all relevant material usually specified on written notes, flip charts, pictures, etc. Afterwards comprehensible requirements need to be specified for software implementation and testing. These activities are mostly performed manually, which causes process delays and software quality attributes like reliability, usability, comprehensibility, etc., are diminished causing software devaluation. Innovative aspects. This research idea paper proposes a framework for automating the tasks of requirements specification. The proposed framework involves computational mechanisms to enable the automatic generation of software design while requirements are discussed. The innovative aspect of this research comes from digitally transforming the software development life cycle (SDLC) where requirements are generated “on the fly” and virtual reality systems are in place. Potential to make change. The proposed framework has the potential to renovate the role of software analysts, which can experience substantial reduction of manual tasks, more efficient communication, dedication to more analytical tasks, and assurance of software quality from conception phases. This research idea paper introduces the framework for automating the task of requirements specification, and report our progress. We conclude the paper by outlining lessons learnt and future lines of work.


title: Exception Handling in the Context of Fragment-Based Case Management

text: Case Management supports knowledge workers in defining, executing, and monitoring the handling of their cases, e.g. in healthcare or logistics. Fragment-based case management (fCM) allows to define a case model with the help of several process fragments, which can be flexible combined at run-time based on case characteristics and the case worker’s intuition. Cases are often influenced by unknown exception, e.g., the sudden change of patient condition’s or a storm delaying transports. So far, fCM only reacts to known circumstances. In this paper, we want to extend fCM by an exception handling approach. Thereby, existing exception patterns for workflow systems are used and extended by the fragment-level for handling unknown events. In order to enable direct integration and avoid a duplication of semantics, precise rules are specified in order to clarify how to extend which pattern in detail. The applicability of the developed exception handling technique is exemplified on a last mile delivery for parcels.


title: Does Enterprise Architecture Support Customer Experience Improvement? Towards a Conceptualization in Digital Transformation Context

text: Customer Experience (CE) is often presented as a competitive battlefield in the new digital context. However, it is defined so broadly, so holistically, that companies find it challenging to improve it through well-defined projects with an impact analysis of the different changes that could be brought about. Enterprise Architecture Management (EAM) is supposed to be a suitable means to support the management of such transformation projects. However, the depth and disruptive nature of these changes raise multiple questions concerning the adequacy of EAM for Customer Experience Improvement (CEI). In current corporate practice, there seems to be no regular application of EAM as a central support service for CEI in the digital context. In this paper, we explore how EAM can support CEI and examine how digitalization transforms the customer experience. We further identify the required information inputs for these transformations. Based on this foundation, we identify content elements that EAM can provide by analyzing EAM meta-models. Comparing the requirements by CEI projects and the supply by EAM shows that EAM, in general, provides valuable inputs for organizational issues and roles but shows weaknesses when it comes to information about trends, contextual and environmental information.


title: A Multi-concern Method for Identifying Business Services: A Situational Method Engineering Study

text: Business services are offerings that enable organizations to achieve their strategic objectives by making their functionality accessible to their customers and business partners. Thus, organizations pay significant attention to and invest in the explicit identification and definition of their business services. This is, however, not a trivial endeavor as multiple concerns that are intrinsic to the concept of business service should be taken into consideration in identifying services. Existing business service identification methods used in isolation do not offer adequate coverage for these concerns. Addressing this issue, we propose a novel method assembled by situational method engineering from a set of existing service identification methods, taking the best aspects from each of them. In this paper, we present an instantiation of the situational method engineering approach alongside the details of the constructed method. We also provide a demonstration of the method with an illustrative scenario based on a real-life business case.


title: Enforcing a Cross-Organizational Workflow: An Experience Report

text: Today business processes often exceed organizational boundaries and the participants may not fully trust each other. In the past, this trust was guaranteed solely through legal contracts. To digitally establish trust without requiring a trusted third party, Blockchain technology together with Smart Contracts is used to ensure that involved organizations can not break their agreements. This experience report introduces a workflow enforcement method for a particular use case, the certification of the construction of industrial plants. The method comprises the modelling of the workflow, the verification of the models and the translation into Smart Contracts.


title: A New DEMO Modelling Tool that Facilitates Model Transformations

text: The age of digitization requires rapid design and re-design of enterprises. Rapid changes can be realized using conceptual modelling. The design and engineering methodology for organizations (DEMO) is an established modelling method for representing the organization domain of an enterprise. However, heterogeneity in enterprise design stakeholders generally demand for transformations between conceptual modelling languages. Specifically, in the case of DEMO, a transformation into business process modelling and notation (BPMN) models is desirable to account to both, the semantic sound foundation of the DEMO models, and the wide adoption of the de-facto industry standard BPMN. Model transformation can only be efficiently applied if tool support is available. Our research starts with a state-of-the-art analysis, comparing existing DEMO modelling tools. Using a design science research approach, our main contribution is the development of a DEMO modelling tool on the ADOxx platform. One of the main features of our tool is that it addresses stakeholder heterogeneity by enabling transformation of a DEMO organization construction diagram (OCD) into a BPMN collaboration diagram. A demonstration case shows the feasibility of our newly developed tool.


title: A Formal Basis for Business Model Evaluation with Linguistic Summaries: (Work-in-Progress Paper)

text: Given its essential role in understanding, explaining and structuring digital innovation, we see the increased prevalence of the business model concept as a unit of analysis in IS research. In contemporary, fast-paced markets, business models are volatile in nature and should be continuously innovated to accommodate new customer needs and technology developments. Business model innovation can be considered as an iterative process to guide business models from ideation towards implementation, in which the proper evaluation of business model prototypes is essential. For this evaluation, we need normative guidance, tools and rules to understand the relative performance of a new business model design. In the early design phases, this implies dealing with high levels of uncertainty. A few techniques and methods have been proposed for this purpose, but these lack the formal basis required for systematical application and development of automated evaluation tools. As a novel approach, we have earlier proposed the application of linguistic summarization to support early-phase, soft-quantitative business model evaluation. In this paper, we focus on a structural formalization of this approach as the basis for the development of well-defined user guidelines and automated evaluation tools. In doing so, we bridge the existing gap between qualitative and quantitative business model evaluation. We demonstrate the formalization by means of a running case inspired by a real-world project in the highly dynamic urban mobility domain.


title: Application of Noninvasive Ventilation in the ObstetricalPatient

text: Acute respiratory failure in pregnancy is considered a common indication for ICU admissions in the obstetrical population. NIV (i.e., NIPPV and HFNC), although controversial, have been shown to be safe and effective in the treatment of acute respiratory failure and can help prevent invasive mechanical ventilation during pregnancy in a variety of scenarios. However, evidence is limited with mainly case reports and case series reported in the literature, NIV modalities have similar indications and contraindications in the pregnant patient as the general population. Methodology: Case reports, prospective RCTs, and meta-analysis involving adult patients with the application of NIPPV as a support strategy for obstetric patients with acute respiratory failure were reviewed. To increase the sensitivity of the search, a combination of terms was utilized such as “high flow nasal canula” with “noninvasive ventilation” and “pregnancy” or “obstetrics” and “acute respiratory failure” or “Acute hypoxic respiratory failure” or “Acute hypercapnic respiratory failure” as keywords. Three electronic databases were searched (Google Scholar, PubMed, and Cochrane Library) from 2017 to 2019. Abstracts and full text publications were screened to fit the search criteria.


title: Integrated On-demand Modeling for Configuration of Trusted ICT Supply Chains

text: Digital enterprises and their networks increasingly rely on advanced decision-making capabilities, however, development of decision-making models requires significant effort and is often performed independently of other digitalization activities. Additionally, dynamic nature of many decision-making problems requires rapid ramp-up of decision-making capabilities. To addresses these challenges, this position paper proposes to elaborate a method for integrated on-demand decision modeling. The method combines mathematical programming and data analytics models to create case specific models on the basis of generic decision-making models. The integrated model and its data supply pipelines are configured using enterprise models allowing for consistent and rapid model deployment. The integrated model is intended for the trusted ICT supply chain configuration problem though it can be used for solving various types of decision-making problems. The main expected results are formulation of the new type decision-making model and the method for on-demand configuration of such models.


title: Reference Method for the Development of Domain Action Recognition Classifiers: The Case of Medical Consultations

text: Advances in human action recognition and interaction recognition enable the reliable execution of action classification tasks through machine learning algorithms. However, no systematic approach for developing such classifiers exists and since actions vary between domains, appropriate and usable datasets are uncommon. In this paper, we propose a reference method that assists non-experts in building classifiers for domain action recognition. To demonstrate feasibility, we instantiate it in a case study in the medical domain that concerns the recognition of basic actions of general practitioners. The developed classifier is effective, as it shows a prediction accuracy of 75.6% for the medical action classification task and of more than 90% for three related classification tasks. The study shows that the method can be applied to a specific activity context and that the resulting classifier has an acceptable prediction accuracy. In the future, fine-tuning of the method parameters will endorse the applicability to other domains.


title: Business Process Monitoring on Blockchains: Potentials and Challenges

text: The ability to enable a tamper-proof distribution of immutable data has boosted the studies around the adoption of blockchains also in Business Process Management. In this direction, current research work primarily focuses on blockchain-based business process design, or on execution engines able to enact processes through smart contracts. Although very relevant, less studies have been devoted so far on how the adoption of blockchains can be beneficial to business process monitoring. This work goes into this direction by providing an insightful analysis to understand the benefits as well as the hurdles of blockchain-enabled business process monitoring. In particular, this work considers the adoption of programmable blockchain platforms to manage the generation, distribution, and analysis of business process monitoring data.


title: An Empirical Investigation of the Intuitiveness of Process Landscape Designs

text: Process landscapes define the scope and relationships between an organization’s business processes and are therefore essential for their management. However, in contrast to business process diagrams, where nowadays BPMN prevails, process landscape diagrams lack standardization, which results in numerous process landscape designs. Accordingly, our goal was to investigate how intuitive are current landscape designs to users with low expertise, as well as users having expertise in BPMN and landscape modeling. A total of 302 subjects participated in the research showing that previous expertise impacts the interpretation of landscape elements and designs whereas, in the case of having contextual information, subjects responded more consistently. The results also show that the basic relationships between processes are intuitive to users, also in the case when only proximity between shapes is facilitated. Our findings may imply future designs of languages for process landscapes. They also may be useful for those who actually model process landscape diagrams and search for suitable notations.


title: A Modeling Method for Systematic Architecture Reconstruction of Microservice-Based Software Systems

text: Microservice Architecture (MSA) is an approach to architecting service-based software systems, which aims for decreasing service coupling to enable independent service development and deployment. Consequently, the adoption of MSA is expected to particularly benefit the scalability, maintainability, and reliability of monolithic systems. However, MSA adoption also increases architectural complexity in service design, implementation, and operation. As a result, Software Architecture Reconstruction (SAR) of microservice architectures is aggravated. This paper presents a modeling method that systematizes SAR of microservice architectures with the goal to facilitate its execution. The method yields reconstruction models for certain architecture viewpoints in MSA to enable efficient architecture analysis. We validate the method’s applicability by means of a case study architecture and the assessment of its risk in technical debt using derived reconstruction models.


title: Chatting About Processes in Digital Factories: A Model-Based Approach

text: Using chatbots in digital factories, to interact with devices through instant messages and voice commands, can make the understanding of underlying manufacturing, logistic and business processes easier for workers. Intelligent chatbots can provide flexible conversations and tailor them to the specific users who are interacting. The iCHAT framework conceptually represents all the aspects related to a conversation, with different facets for the user, the conversation flow, and the conversation contents, and combining them to obtain a flexible interaction with the user. In digital factories, flexible production is driven by processes combining different services. In this paper, we present an original approach extending iCHAT to be able to chat about processes, aiming at instructing a worker about a process.


title: Cherry-Picking from Spaghetti: Multi-range Filtering of Event Logs

text: Mining real-life event logs results into process models which provide little value to the process analyst without support for handling complexity. Filtering techniques are specifically helpful to tackle this problem. These techniques have been focusing on leaving out infrequent aspects of the process which are considered outliers. However, it is exactly in these outliers where it is possible to gather important insights on the process. This paper addresses this problem by defining multi-range filtering. Our technique not only allows to combine both frequent and non-frequent aspects of the process but it supports any user-defined intervals of frequency of activities and variants. We evaluate our approach through a prototype based on the PM4Py library and show the benefits in comparison to existing filtering techniques.


title: Modeling Complex Business Environments for Context Aware Systems

text: Context awareness in complex business environments has been recognized as a major challenge for enterprise information systems. Although, the development of a context aware system in different application domains is convincingly documented in current literature, the design of such systems requires greater attention. Particularly, investigating the context of a context aware system. In this paper, we present a step-wise method to model a complex business environment. The method provides an approach for investigating a context and using the investigation results in subsequent design steps.


title: Automated Planning for Supporting Knowledge-Intensive Processes

text: Knowledge-intensive Processes (KiPs) are processes characterized by high levels of unpredictability and dynamism. Their process structure may not be known before their execution. One way to cope with this uncertainty is to defer decisions regarding the process structure until run time. In this paper, we consider the definition of the process structure as a planning problem. Our approach uses automated planning techniques to generate plans that define process models according to the current context. The generated plan model relies on a metamodel called METAKIP that represents the basic elements of KiPs. Our solution explores Markov Decision Processes (MDP) to generate plan models. This technique allows uncertainty representation by defining state transition probabilities, which gives us more flexibility than traditional approaches. We construct an MDP model and solve it with the help of the PRISM model-checker. The solution is evaluated by means of a proof of concept in the medical domain which reveals the feasibility of our approach.


title: Secure Multi-party Computation for Inter-organizational Process Mining

text: Process mining is a family of techniques for analyzing business processes based on event logs extracted from information systems. Mainstream process mining tools are designed for intra-organizational settings, insofar as they assume that an event log is available for processing as a whole. The use of such tools for inter-organizational process analysis is hampered by the fact that such processes involve independent parties who are unwilling to, or sometimes legally prevented from, sharing detailed event logs with each other. In this setting, this paper proposes an approach for constructing and querying a common artifact used for process mining, namely the frequency and time-annotated Directly-Follows Graph (DFG), over multiple event logs belonging to different parties, in such a way that the parties do not share the event logs with each other. The proposal leverages an existing platform for secure multi-party computation, namely Sharemind. Since a direct implementation of DFG construction in Sharemind suffers from scalability issues, we propose to rely on vectorization of event logs and to employ a divide-and-conquer scheme for parallel processing of sub-logs. The paper reports on experiments that evaluate the scalability of the approach on real-life logs.


title: A Journey to BSO: Evaluating Earlier and More Recent Ideas of Mario Bunge as a Foundation for Information Systems and Software Development

text: A prominent theoretical foundation for IT analysis, design and development is general ontology - a branch of philosophy which studies what exists in reality. A widely used general ontology is BWW (Bunge-Wand-Weber) – based on ideas of the philosopher and physicist Mario Bunge, synthesized by Wand and Weber. It is regarded as a major contribution to conceptual modeling, database design, data collection design and information quality, as well as theory of IT. At the same time, the ontology was founded on an early subset of Bunge’s philosophy and Bunge’s ideas have evolved since then. An important question, therefore, is: do the more recent ideas expressed by Bunge call for a new ontology? In this paper we conduct an analysis of research by Bunge aiming at addressing this question. We compare the constructs of BWW with what we call Bunge’s Systemist Ontology (BSO) – a new ontology based on broader and more recent ideas developed by Bunge. Informed by this comparison we offer suggestions for ontology studies as well as future applications of Bunge in conceptual modeling and other areas of IT.


title: An Evaluation of the Intuitiveness of the PGA Modeling Language Notation

text: The Process-Goal Alignment (PGA) modeling method is a domain-specific modeling language that aims to achieve strategic fit of the business strategy with the internal infrastructure and processes. To ensure the acceptance and correct understanding of PGA models by business-oriented end-users, an intuitively understandable notation is of paramount importance. However, the current PGA notation was not formally tested up to now. In the paper at hand, we apply an evaluation technique for testing the intuitiveness of domain-specific modeling languages to bridge that research gap. Based on an analysis of the tasks, we propose improvements to six elements of the initial PGA notation. Our research contributes a comprehensive description of the empirical modeling language evaluation, which enables the reproducibility of the evaluation procedure by the conceptual modeling community.


title: Dynamically Switching Execution Context in Data-Centric BPM Approaches

text: In contemporary business process management software, the context in which a process is executed is largely static. While the execution of the process itself may be flexible, on-the-fly changes to the context, i.e., physical or logical surroundings, are either limited or impossible. This paper presents concepts for enabling context switching at runtime for the object-aware process management paradigm. Such context switches are enabled at various granularity levels, such as shifting entire process instances to different systems, or migrating sub-processes between different parent processes. We further contribute the algorithms employed in our proof-of-concept implementation and discuss use cases in which context switching capabilities can be utilized. Implementing these advanced concepts helps showcase the maturity of data-centric BPM.


title: Truncated Trace Classifier. Removal of Incomplete Traces from Event Logs

text: We consider truncated traces, which are incomplete sequences of events. This typically happens when dealing with streaming data or when the event log extraction process cuts the end of the trace. The existence of truncated traces in event logs and their negative impacts on process mining outcomes have been widely acknowledged in the literature. Still, there is a lack of research on algorithms to detect them. We propose the Truncated Trace Classifier (TTC), an algorithm that distinguishes truncated traces from the ones that are not truncated. We benchmark 5 TTC implementations that use either LSTM or XGBOOST on 13 real-life event logs. Accurate TTCs have great potential. In fact, filtering truncated traces before applying a process discovery algorithm greatly improves the precision of the discovered process models, by 9.1%. Moreover, we show that TTCs increase the accuracy of a next event prediction algorithm by up to 7.5%.


title: Scheduling Processes Without Sudden Termination

text: Dynamic controllability is the most general criterion to guarantee that a process can be executed without time failures. However, it admits schedules with an undesirable property: starting an activity without knowing its deadline. We analyze the specific constellations of temporal constraints causing such a sudden termination. Consequently, we introduce the somewhat stricter notion of semi-dynamic controllability, and present necessary and sufficient conditions to guarantee that a process can be executed without time failures and without sudden termination. A sound and complete algorithm for checking whether a process is semi-dynamically controllable complements the approach.


title: Towards Automating the Synthesis of Chatbots for Conversational Model Query

text: Conversational interfaces (also called chatbots) are being increasingly adopted in various domains such as e-commerce or customer service, as a direct communication channel between companies and end-users. Their advantage is that they can be embedded within social networks, and provide a natural language (NL) interface that enables their use by non-technical users. While there are many emerging platforms for building chatbots, their construction remains a highly technical, challenging task. In this paper, we propose the use of chatbots to facilitate querying domain-specific models. This way, instead of relying on technical query languages (e.g., OCL), models are queried using NL as this can be more suitable for non-technical users. To avoid manual programming, our solution is based on the automatic synthesis of the model query chatbots from a domain meta-model. These chatbots communicate with an EMF-based modelling backend using the Xatkit framework.


title: Mining BPMN Processes on GitHub for Tool Validation and Development

text: Today, business process designers can choose from an increasing number of analysis tools to check their process model with respect to defects or flaws, before, e.g., deploying the model in a process engine. Answering questions about the tools’ effectiveness though is difficult, as their validation often lacks empirical evidence. In particular, for a modeling language like BPMN, where the process is the product, tools are validated by means of case studies or even artificial process examples. We here advocate instead an approach to systematically mine software repositories on GitHub.com for a large corpus of BPMN business process models and discuss how it can be used for tool validation and guiding tool development, using the example of the linting tool BPMNspector.


title: Ordering a Sparse Graph to Minimize the Sum of Right Ends of Edges

text: Motivated by a warehouse logistics problem we study mappings of the vertices of a graph onto prescribed points on the real line that minimize the sum (or equivalently, the average) of the coordinates of the right ends of all edges. We focus on graphs whose edge numbers do not exceed the vertex numbers too much, that is, graphs with few cycles. Intuitively, dense subgraphs should be placed early in the ordering, in order to finish many edges soon. However, our main “calculation trick” is to compare the objective function with the case when (almost) every vertex is the right end of exactly one edge. The deviations from this case are described by “charges” that can form “dipoles”. This reformulation enables us to derive polynomial algorithms and NP-completeness results for relevant special cases, and FPT results.


title: Two Robots Patrolling on a Line: Integer Version and Approximability

text: Suppose that two robots can move at unit speed on a line and must visit certain points called stations infinitely often. Every station allows some maximal waiting time between two visits. The problem is to construct an optimal schedule for the robots. While the one-robot problem is easy to solve in linear time, already for two robots the complexity is open. Chuangpishit, Czyzowicz, Gasieniec, Georgiou, Jurdzinski, and Kranakis (SOFSEM 2018) found a [Formula: see text]-approximation algorithm. Here we provide a PTAS, accomplished by rounding and (perhaps more surprisingly) by using the well-quasi ordering of vectors of positive integers. The result is not very practical in the present form, but further investigation of the integer version may make it more usable.


title: The Steiner Problem for Count Matroids

text: We introduce and study a generalization of the well-known Steiner tree problem to count matroids. In the count matroid [Formula: see text], defined on the edge set of a graph [Formula: see text], a set [Formula: see text] is independent if every vertex set [Formula: see text] spans at most [Formula: see text] edges of F. The graph is called (k, l)-tight if its edge set is independent in [Formula: see text] and [Formula: see text] holds. Given a graph [Formula: see text], a non-negative length function [Formula: see text], a set [Formula: see text] of terminals and parameters k, l, our goal is to find a shortest (k, l)-tight subgraph of G that contains the terminals. Since [Formula: see text] is isomorphic to the graphic matroid of G, the special case [Formula: see text] corresponds to the Steiner tree problem. We obtain other interesting problems by choosing different parameters: for example, in the case [Formula: see text], [Formula: see text] the target is a shortest rigid subgraph containing all terminals. First we show that this problem is NP-hard even if [Formula: see text], [Formula: see text], and w is metric, or [Formula: see text] and [Formula: see text]. As a by-product of this result we obtain that finding a shortest circuit in [Formula: see text] is NP-hard. Then we design a [Formula: see text]-approximation algorithm for the metric version of the problem with parameters [Formula: see text], for all [Formula: see text]. In particular, we obtain a 3-approximation algorithm for the Steiner version of the shortest rigid subgraph problem. We also show that the metric version can be solved in polynomial time for [Formula: see text], [Formula: see text], provided |T| is fixed.


title: The Micro-world of Cographs

text: Cographs constitute a small point in the atlas of graph classes. However, by zooming in on this point, we discover a complex world, where many parameters jump from finiteness to infinity. In the present paper, we identify several milestones in the world of cographs and create a hierarchy of graph parameters grounded on these milestones.


title: Between Proper and Strong Edge-Colorings of Subcubic Graphs

text: In a proper edge-coloring the edges of every color form a matching. A matching is induced if the end-vertices of its edges induce a matching. A strong edge-coloring is an edge-coloring in which the edges of every color form an induced matching. We consider intermediate types of edge-colorings, where some of the colors are allowed to form matchings, and the remaining form induced matchings. Our research is motivated by the conjecture proposed in a recent paper on S-packing edge-colorings (N. Gastineau and O. Togni, On S-packing edge-colorings of cubic graphs, Discrete Appl. Math. 259 (2019)). We prove that every graph with maximum degree 3 can be decomposed into one matching and at most 8 induced matchings, and two matchings and at most 5 induced matchings. We also show that if a graph is in class I, the number of induced matchings can be decreased by one, hence confirming the conjecture for this class of graphs.


title: Fair Packing of Independent Sets

text: In this work we add a graph theoretical perspective to a classical problem of fairly allocating indivisible items to several agents. Agents have different profit valuations of items and we allow an incompatibility relation between pairs of items described in terms of a conflict graph. Hence, every feasible allocation of items to the agents corresponds to a partial coloring, that is, a collection of pairwise disjoint independent sets. The sum of profits of vertices/items assigned to one color/agent should be optimized in a maxi-min sense. We derive complexity and algorithmic results for this problem, which is a generalization of the classical Partition and Independent Set problems. In particular, we show that the problem is strongly NP-complete in the classes of bipartite graphs and their line graphs, and solvable in pseudo-polynomial time in the classes of cocomparability graphs and biconvex bipartite graphs.


title: A Family of Tree-Based Generators for Bubbles in Directed Graphs

text: Bubbles are pairs of internally vertex-disjoint (s, t)-paths in a directed graph. In de Bruijn graphs built from reads of RNA and DNA data, bubbles represent interesting biological events, such as alternative splicing (AS) and allelic differences (SNPs and indels). However, the set of all bubbles in a de Bruijn graph built from real data is usually too large to be efficiently enumerated and analysed in practice. In particular, despite significant research done in this area, listing bubbles still remains the main bottleneck for tools that detect AS events in a reference-free context. Recently, in [1] the concept of a bubble generator was introduced as a way for obtaining a compact representation of the bubble space of a graph. Although this generator was quite effective in finding AS events, preliminary experiments showed that it is about 5 times slower than state-of-art methods. In this paper we propose a new family of bubble generators which improve substantially on the previous generator: generators in this new family are about two orders of magnitude faster and are still able to achieve similar precision in identifying AS events. To highlight the practical value of our new generators, we also report some experimental results on a real dataset.


title: Acyclic Matching in Some Subclasses of Graphs

text: A subset [Formula: see text] of edges of a graph [Formula: see text] is called a matching if no two edges of M share a common vertex. A matching M in a graph G is called an acyclic matching if G[V(M)], the subgraph of G induced by the M-saturated vertices of G is acyclic. The Acyclic Matching Problem is the problem of finding an acyclic matching of maximum size. The decision version of the Acyclic Matching Problem is known to be NP-complete for general graphs as well as for bipartite graphs. In this paper, we strengthen this result by showing that the decision version of the Acyclic Matching Problem remains NP-complete for comb-convex bipartite graphs and dually-chordal graphs. On the positive side, we present linear time algorithms to compute an acyclic matching of maximum size in split graphs and proper interval graphs. Finally, we show that the Acyclic Matching Problem is hard to approximate within a factor of [Formula: see text] for any [Formula: see text], unless [Formula: see text] and the Acyclic Matching Problem is APX-complete for [Formula: see text]-regular graphs for [Formula: see text], where k is a constant.


title: Coordinating Swarms of Objects at Extreme Dimensions

text: We describe a variety of algorithmic challenges arising from coordination and reconfiguration of swarms of potentially many objects, ranging in size from minuscule particles all the way to far-away satellite swarms. Particular results include methods for coordinating the motion of vehicles in traffic in order to avoid inefficient stop-and-go congestions; using uniform global forces for controlling particle swarms; online triangulation and structured exploration; cohesive control for swarms of robots with only local communication; coordinated motion planning for efficiently reconfiguring an arrangement of robots; and constructing and reconfiguring large-scale structures by finite automata. All presented work is based on collaborations with a variety of authors, who are named in the respective sections of this overview.


title: Bounded Degree Group Steiner Tree Problems

text: Motivated by some open problems posed in [13], we study three problems that seek a low degree subtree T of a graph [Formula: see text]. In the Min-Degree Group Steiner Tree problem we are given a collection of node subsets (groups), and T should contain a node from every group. In the Min-Degree Steiner k-Tree problem we are given a set R of terminals and an integer k, and T should contain k terminals. In both problems the goal is to minimize the maximum degree of T. In the more general Degrees Bounded Min-Cost Group Steiner Tree problem, we are also given edge costs and individual degree bounds [Formula: see text]. The output tree T should obey the degree constraints [Formula: see text] for all [Formula: see text], and among all such trees we seek one of minimum cost. When the input is a tree, an [Formula: see text] approximation for the cost is given in [10]. Our first result generalizes [10] – we give a bicriteria [Formula: see text]-approximation algorithm for Degrees Bounded Min-Cost Group Steiner Tree problem on tree inputs. This matches the cost ratio of [10] but also approximates the degrees within [Formula: see text]. Our second result shows that if Min-Degree Group Steiner Tree admits ratio [Formula: see text] then Min-Degree Steiner [Formula: see text]-Tree admits ratio [Formula: see text]. Combined with [12], this implies an [Formula: see text]-approximation for Min-Degree Steiner [Formula: see text]-Tree on general graphs, in quasi-polynomial time. Our third result is a polynomial time [Formula: see text]-approximation algorithm for Min-Degree Group Steiner Tree on bounded treewidth graphs.


title: On the Complexity of Broadcast Domination and Multipacking in Digraphs

text: We study the complexity of the two dual covering and packing distance-based problems Broadcast Domination and Multipacking in digraphs. A dominating broadcast of a digraph D is a function [Formula: see text] such that for each vertex v of D, there exists a vertex t with [Formula: see text] having a directed path to v of length at most f(t). The cost of f is the sum of f(v) over all vertices v. A multipacking is a set S of vertices of D such that for each vertex v of D and for every integer d, there are at most d vertices from S within directed distance at most d from v. The maximum size of a multipacking of D is a lower bound to the minimum cost of a dominating broadcast of D. Let Broadcast Domination denote the problem of deciding whether a given digraph D has a dominating broadcast of cost at most k, and Multipacking the problem of deciding whether D has a multipacking of size at least k. It is known that Broadcast Domination is polynomial-time solvable for the class of all undirected graphs (that is, symmetric digraphs), while polynomial-time algorithms for Multipacking are known only for a few classes of undirected graphs. We prove that Broadcast Domination and Multipacking are both NP-complete for digraphs, even for planar layered acyclic digraphs of small maximum degree. Moreover, when parameterized by the solution cost/solution size, we show that the problems are respectively W[2]-hard and W[1]-hard. We also show that Broadcast Domination is FPT on acyclic digraphs, and that it does not admit a polynomial kernel for such inputs, unless the polynomial hierarchy collapses to its third level. In addition, we show that both problems are FPT when parameterized by the solution cost/solution size together with the maximum out-degree. Finally, we give for both problems polynomial-time algorithms for some subclasses of acyclic digraphs.


title: Algorithms for Constructing Anonymizing Arrays

text: Attribute-based methods are inherently identity-less as authorization decisions are made in terms of attributes possessed by the subject rather than identity. However, anonymity against the system is not guaranteed when attribute distribution allows for the composition of a policy that few subjects can satisfy. An anonymizing array ensures that any assignment of values to t attributes that appears in the array appears at least r times. When an anonymizing array is used for subjects registered to a system and policies contain conjunctions of at most t attributes, the system cannot identify the subject using the policy to to gain authorization with greater than [Formula: see text] probability. Anonymizing arrays are similar to covering arrays with higher coverage and constraints, but have an additional desired property, homogeneity, due to their application domain. In this paper, we develop constructions for anonymizing arrays and propose a post-optimization mechanism to reduce homogeneity.


title: A Parameterized Perspective on Attacking and Defending Elections

text: We consider the problem of protecting and manipulating elections by recounting and changing ballots, respectively. Our setting involves a plurality-based election held across multiple districts, and the problem formulations are based on the model proposed recently by [Elkind et al., IJCAI 2019]. It turns out that both of the manipulation and protection problems are NP-complete even in fairly simple settings. We study these problems from a parameterized perspective with the goal of establishing a more detailed complexity landscape. The parameters we consider include the number voters, and the budgets of the attacker and the defender. While we observe fixed-parameter tractability when parameterizing by number of voters, our main contribution is a demonstration of parameterized hardness when working with the budgets of the attacker and the defender.


title: On the Complexity of Singly Connected Vertex Deletion

text: A digraph D is singly connected if for all ordered pairs of vertices [Formula: see text], there is at most one path in D from u to v. In this paper, we study the Singly Connected Vertex Deletion (SCVD) problem: Given an n-vertex digraph D and a positive integer k, does there exist a set [Formula: see text] such that [Formula: see text] and [Formula: see text] is singly connected? This problem may be seen as a directed counterpart of the (Undirected) Feedback Vertex Set problem, as an undirected graph is singly connected if and only if it is acyclic. SCVD is known to be NP-hard on general digraphs. We study the complexity of SCVD on various classes of digraphs such as tournaments, and various generalisations of tournaments such as digraphs of bounded independence number, in- and out-tournaments and local tournaments. We show that unlike the Feedback Vertex Set on Tournaments (FVST) problem, SCVD is polynomial time solvable on tournaments. In addition, we show that SCVD is polynomial time solvable on digraphs of bounded independence number, and on the class of acyclic local tournaments. We also study the parameterized complexity of SCVD, with k as the parameter, on the class of in-tournaments. And we show that on in-tournaments (and out-tournaments), SCVD admits a fixed-parameter tractable algorithm and a quadratic kernel. We also show that on the class of local tournaments, which is a sub-class of in-tournaments, SCVD admits a linear kernel.


title: Nonexistence Certificates for Ovals in a Projective Plane of Order Ten

text: In 1983, a computer search was performed for ovals in a projective plane of order ten. The search was exhaustive and negative, implying that such ovals do not exist. However, no nonexistence certificates were produced by this search, and to the best of our knowledge the search has never been independently verified. In this paper, we rerun the search for ovals in a projective plane of order ten and produce a collection of nonexistence certificates that, when taken together, imply that such ovals do not exist. Our search program uses the cube-and-conquer paradigm from the field of satisfiability (SAT) checking, coupled with a programmatic SAT solver and the nauty symbolic computation library for removing symmetries from the search.


title: Optimal In-place Algorithms for Basic Graph Problems

text: We present linear time in-place algorithms for several fundamental graph problems including the well-known graph search methods (like depth-first search, breadth-first search, maximum cardinality search), connectivity problems (like biconnectivity, 2-edge connectivity), decomposition problem (like chain decomposition) among various others, improving the running time (by polynomial multiplicative factor) of the recent results of Chakraborty et al. [ESA, 2018] who designed [Formula: see text] time in-place algorithms for some of the above mentioned problems. The running times of all our algorithms are essentially optimal as they run in linear time. One of the main ideas behind obtaining these algorithms is the detection and careful exploitation of sortedness present in the input representation for any graph without loss of generality. This observation alone is powerful enough to design some basic linear time in-place algorithms, but more non-trivial graph problems require extra techniques which, we believe, may find other applications while designing in-place algorithms for different graph problems in future.


title: Edge-Disjoint Branchings in Temporal Graphs

text: A temporal digraph [Formula: see text] is a triple [Formula: see text] where G is a digraph, [Formula: see text] is a function on V(G) that tells us the time stamps when a vertex is active, and [Formula: see text] is a function on E(G) that tells for each [Formula: see text] when u and v are linked. Given a static digraph G, and a subset [Formula: see text], a spanning branching with root R is a subdigraph of G that has exactly one path from R to each [Formula: see text]. In this paper, we consider the temporal version of Edmonds’ classical result about the problem of finding k edge-disjoint spanning branchings respectively rooted at given [Formula: see text]. We introduce and investigate different definitions of spanning branchings, and of edge-disjointness in the context of temporal graphs. A branching [Formula: see text] is vertex-spanning if the root is able to reach each vertex v of G at some time where v is active, while it is temporal-spanning if v can be reached from the root at every time where v is active. On the other hand, two branchings [Formula: see text] and [Formula: see text] are edge-disjoint if they do not use the same edge of G, and are temporal-edge-disjoint if they can use the same edge of G but at different times. This lead us to four definitions of disjoint spanning branchings and we prove that, unlike the static case, only one of these can be computed in polynomial time, namely the temporal-edge-disjoint temporal-spanning branchings problem, while the other versions are [Formula: see text]-complete, even under very strict assumptions.


title: Parameterized Algorithms for Partial Vertex Covers in Bipartite Graphs

text: In this paper, we discuss parameterized algorithms for variants of the partial vertex cover problem. Recall that in the classical vertex cover problem (VC), we are given a graph [Formula: see text] and a number K and asked if we can cover all of the edges in E, using at most K vertices from V. In the partial vertex cover problem (PVC), in addition to the parameter K, we are given a second parameter [Formula: see text] and the question is whether we can cover at least [Formula: see text] of the edges in E using at most K vertices from V. The weighted generalizations of the VC and PVC problems are called the weighted vertex cover (WVC) and the partial weighted vertex cover problem (WPVC) respectively. In the WPVC problem, we are given two parameters R and L, associated respectively with the vertex set V and edge set E of the graph [Formula: see text]. Additionally, we are given non-negative integral weight functions for the vertices and the edges. The goal then is to cover edges of total weight at least L, using vertices of total weight at most R. (In the WVC problem, the goal is to cover all the edges with vertices whose total weight is at most R). This paper studies several variants of the PVC problem and establishes new results from the perspective of fixed-parameter tractability and W[1]-hardness. We also introduce a new problem called the partial vertex cover with matching constraint and show that it is fixed-parameter tractable for a certain class of graphs.


title: Skyline Computation with Noisy Comparisons

text: Given a set of n points in a d-dimensional space, we seek to compute the skyline, i.e., those points that are not strictly dominated by any other point, using few comparisons between elements. We adopt the noisy comparison model [15] where comparisons fail with constant probability and confidence can be increased through independent repetitions of a comparison. In this model motivated by Crowdsourcing applications, Groz and Milo [18] show three bounds on the query complexity for the skyline problem. We improve significantly on that state of the art and provide two output-sensitive algorithms computing the skyline with respective query complexity [Formula: see text] and [Formula: see text], where k is the size of the skyline and [Formula: see text] the expected probability that our algorithm fails to return the correct answer. These results are tight for low dimensions.


title: Equitable d-degenerate Choosability of Graphs

text: Let [Formula: see text] be the class of d-degenerate graphs and let L be a list assignment for a graph G. A colouring of G such that every vertex receives a colour from its list and the subgraph induced by vertices coloured with one color is a d-degenerate graph is called the [Formula: see text]-colouring of G. For a k-uniform list assignment L and [Formula: see text], a graph G is equitably [Formula: see text]-colorable if there is an [Formula: see text]-colouring of G such that the size of any colour class does not exceed [Formula: see text]. An equitable [Formula: see text]-colouring is a generalization of an equitable list coloring, introduced by Kostochka et al., and an equitable list arboricity presented by Zhang. Such a model can be useful in the network decomposition where some structural properties on subnets are imposed. In this paper we give a polynomial-time algorithm that for a given (k, d)-partition of G with a t-uniform list assignment L and [Formula: see text], returns its equitable [Formula: see text]-colouring. In addition, we show that 3-dimensional grids are equitably [Formula: see text]-colorable for any t-uniform list assignment L where [Formula: see text].


title: Iterated Type Partitions

text: This paper introduces a novel parameter, called iterated type partition, that can be computed in polynomial time and nicely places between modular-width and neighborhood diversity. We prove that the Equitable Coloring problem is W[1]-hard when parametrized by the iterated type partition. This result extends to modular-width, answering an open question on the complexity of Equitable Coloring when parametrized by modular-width. On the contrary, we show that the Equitable Coloring problem is FPT when parameterized by neighborhood diversity. Furthermore, we present a scheme for devising FPT algorithms parameterized by iterated type partition, which enables us to find optimal solutions for several graph problems. While the considered problems are already known to be FPT with respect to modular-width, the novel algorithms are both simpler and more efficient. As an example, in this paper, we give an algorithm for the Dominating Set problem that outputs an optimal set in time [Formula: see text], where n and t are the size and the iterated type partition of the input graph, respectively.


title: Connectivity Keeping Trees in 2-Connected Graphs with Girth Conditions

text: Mader conjectured in 2010 that for any tree T of order m, every k-connected graph G with minimum degree at least [Formula: see text] contains a subtree [Formula: see text] such that [Formula: see text] is k-connected. This conjecture has been proved for [Formula: see text]; however, it remains open for general [Formula: see text]; for [Formula: see text], partially affirmative answers have been shown, all of which restrict the class of trees to special subclasses such as trees of order at most 8, trees with diameter at most 4, trees with at most 5 internal vertices, and caterpillars. Instead of restricting the class of trees, we consider 2-connected graphs with girth conditions. We then show that Mader’s conjecture is true for every 2-connected graph G with [Formula: see text], where g(G) and [Formula: see text] denote the girth of G and the minimum degree of a vertex in G, respectively. Besides, we show that for every 2-connected graph G with [Formula: see text], the lower bound of [Formula: see text] on [Formula: see text] in Mader’s conjecture can be improved to [Formula: see text] if [Formula: see text]. Moreover, the lower bound of [Formula: see text] (respectively, [Formula: see text]) on g(G) in these results can be improved to [Formula: see text] (respectively, [Formula: see text] with [Formula: see text]) if no six (respectively, four) cycles of length g(G) have a common path of length [Formula: see text] in G. Mader’s conjecture is interesting not only from a theoretical point of view but also from a practical point of view, since it may be applied to fault-tolerant problems in communication networks. Our proofs lead to [Formula: see text] time algorithms for finding a desired subtree in a given 2-connected graph G satisfying the assumptions.


title: On the Complexity of Stackelberg Matroid Pricing Problems

text: In a Stackelberg pricing problem a distinguished player, the leader, chooses prices for a set of items, and one or several other players, the followers, seeks to buy a feasible subset of the items with minimal costs. The leader’s goal is to maximize her revenue, which is determined by the sold items and their prices. We are interested in cases where the followers’ feasible subsets are given by a combinatorial optimization problem. For example, a pricing problem based on the shortest path problem was used by Labbé et al. [15] to model road-toll setting scenarios. In this paper, we consider Stackelberg pricing problems that are based on matroids. The followers seek to buy a subset that is a basis. More specifically, we consider uniform, partition and laminar matroids. We study the complexity of computing leader-optimal prices for a single and multiple followers. We show that optimal prices can be computed in polynomial time for all three matroids if there is one follower. In general, such pricing problems based on matroids are APX-hard (see [11]). For multiple followers, we show that computing optimal prices for uniform matroids can be done in polynomial time. However, for partition and laminar matroids the pricing problem becomes NP-hard .


title: Strongly Stable and Maximum Weakly Stable Noncrossing Matchings

text: In IWOCA 2019, Ruangwises and Itoh introduced stable noncrossing matchings, where participants of each side are aligned on each of two parallel lines, and no two matching edges are allowed to cross each other. They defined two stability notions, strongly stable noncrossing matching (SSNM) and weakly stable noncrossing matching (WSNM), depending on the strength of blocking pairs. They proved that a WSNM always exists and presented an [Formula: see text]-time algorithm to find one for an instance with n men and n women. They also posed open questions of the complexities of determining existence of an SSNM and finding a largest WSNM. In this paper, we show that both problems are solvable in polynomial time. Our algorithms are applicable to extensions where preference lists may include ties, except for one case which we show to be NP-complete.


title: Decremental Optimization of Dominating Sets Under the Reconfiguration Framework

text: Given a dominating set, how much smaller a dominating set can we find through elementary operations? Here, we proceed by iterative vertex addition and removal while maintaining the property that the set forms a dominating set of bounded size. This can be seen as the optimization variant of the dominating set reconfiguration problem, where two dominating sets are given and the question is merely whether they can be reached from one another through elementary operations. We show that this problem is PSPACE-complete, even if the input graph is a bipartite graph, a split graph, or has bounded pathwidth. On the positive side, we give linear-time algorithms for cographs, trees and interval graphs. We also study the parameterized complexity of this problem. More precisely, we show that the problem is W[2]-hard when parameterized by the upper bound on the size of an intermediary dominating set. On the other hand, we give fixed-parameter algorithms with respect to the minimum size of a vertex cover, or [Formula: see text] where d is the degeneracy and s is the upper bound of the output solution.


title: New Bounds for Maximizing Revenue in Online Dial-a-Ride

text: In the Online-Dial-a-Ride Problem (OLDARP) a server travels to serve requests for rides. We consider a variant where each request specifies a source, destination, release time, and revenue that is earned for serving the request. The goal is to maximize the total revenue earned within a given time limit. We prove that no non-preemptive deterministic online algorithm for OLDARP can be guaranteed to earn more than half the revenue earned by [Formula: see text]. We then investigate the segmented best path ([Formula: see text]) algorithm of [8] for the general case of weighted graphs. The previously-established lower and upper bounds for the competitive ratio of [Formula: see text] are 4 and 6, respectively, under reasonable assumptions about the input instance. We eliminate the gap by proving that the competitive ratio is 5 (under the same assumptions). We also prove that when revenues are uniform, [Formula: see text] has competitive ratio 4. Finally, we provide a competitive analysis of [Formula: see text] on complete bipartite graphs.


title: Polynomial Time Algorithms for Tracking Path Problems

text: Given a graph G, and terminal vertices s and t, the Tracking Paths problem asks to compute a minimum number of vertices to be marked as trackers, such that the sequence of trackers encountered in each [Formula: see text]-[Formula: see text] path is unique. Tracking Paths is NP-hard in both directed and undirected graphs in general. In this paper we give a collection of polynomial time algorithms for some restricted versions of Tracking Paths. We prove that Tracking Paths is polynomial time solvable for chordal graphs and tournament graphs. We prove that Tracking Paths is NP-hard in graphs with bounded maximum degree [Formula: see text], and give a [Formula: see text]-approximate algorithm for the same. We also analyze the version of tracking [Formula: see text]-[Formula: see text] paths where paths are tracked using edges instead of vertices, and we give a polynomial time algorithm for the same. Finally we give a polynomial algorithm which, given an undirected graph G, a tracking set [Formula: see text], and a sequence of trackers [Formula: see text], returns the unique [Formula: see text]-[Formula: see text] path in G that corresponds to [Formula: see text], if one exists.


title: Improved Budgeted Connected Domination and Budgeted Edge-Vertex Domination

text: We consider the Budgeted version of the classical Connected Dominating Set problem (BCDS). Given a graph G and a budget k, we seek a connected subset of at most k vertices maximizing the number of dominated vertices in G. We improve over the previous [Formula: see text] approximation in [Khuller, Purohit, and Sarpatwar, SODA 2014] by introducing a new method for performing tree decompositions in the analysis of the last part of the algorithm. This new approach provides a [Formula: see text] approximation guarantee. By generalizing the analysis of the first part of the algorithm, we are able to modify it appropriately and obtain a further improvement to [Formula: see text]. On the other hand, we prove a [Formula: see text] inapproximability bound, for any [Formula: see text]. We also examine the edge-vertex domination variant, where an edge dominates its endpoints and all vertices neighboring them. In Budgeted Edge-Vertex Domination (BEVD), we are given a graph G, and a budget k, and we seek a, not necessarily connected, subset of k edges such that the number of dominated vertices in G is maximized. We prove there exists a [Formula: see text]-approximation algorithm. Also, for any [Formula: see text], we present a [Formula: see text]-inapproximability result by a gap-preserving reduction from the maximum coverage problem. Finally, we examine the “dual” Partial Edge-Vertex Domination (PEVD) problem, where a graph G and a quota [Formula: see text] are given. The goal is to select a minimum-size set of edges to dominate at least [Formula: see text] vertices in G. In this case, we present a [Formula: see text]-approximation algorithm by a reduction to the partial cover problem.


title: Parameterized Complexity of [Formula: see text]-Path Packing

text: Given a graph [Formula: see text], [Formula: see text], and integers k and [Formula: see text], the [Formula: see text] -Path Packing problem asks to find k vertex-disjoint paths of length [Formula: see text] that have endpoints in A and internal points in [Formula: see text]. We study the parameterized complexity of this problem with parameters |A|, [Formula: see text], k, treewidth, pathwidth, and their combinations. We present sharp complexity contrasts with respect to these parameters. Among other results, we show that the problem is polynomial-time solvable when [Formula: see text], while it is NP-complete for constant [Formula: see text]. We also show that the problem is W[1]-hard parameterized by pathwidth[Formula: see text], while it is fixed-parameter tractable parameterized by treewidth[Formula: see text].


title: On Proper Labellings of Graphs with Minimum Label Sum

text: The 1-2-3 Conjecture states that every nice graph G (without component isomorphic to [Formula: see text]) admits a proper 3-labelling, i.e., a labelling of the edges with 1, 2, 3 such that no two adjacent vertices are incident to the same sum of labels. Another interpretation of this conjecture is that every nice graph G can be turned into a locally irregular multigraph M, i.e., with no two adjacent vertices of the same degree, by replacing each edge by at most three parallel edges. In other words, for every nice graph G, there should exist a locally irregular multigraph M with the same adjacencies and having few edges. We study proper labellings of graphs with the extra requirement that the sum of assigned labels must be as small as possible. That is, given a graph G, we are looking for a locally irregular multigraph [Formula: see text] with the fewest edges possible that can be obtained from G by replacing edges with parallel edges. This problem is quite different from the 1-2-3 Conjecture, as we prove that there is no k such that [Formula: see text] can always be obtained from G by replacing each edge with at most k parallel edges. We investigate several aspects of this problem. We prove that the problem of designing proper labellings with minimum label sum is [Formula: see text]-hard in general, but solvable in polynomial time for graphs with bounded treewidth. We also conjecture that every nice connected graph G admits a proper labelling with label sum at most [Formula: see text], which we verify for several classes of graphs.


title: Further Results on Online Node- and Edge-Deletion Problems with Advice

text: In online edge- and node-deletion problems the input arrives node by node and an algorithm has to delete nodes or edges in order to keep the input graph in a given graph class at all times. We consider graph classes that can be characterized by forbidden sets of induced subgraphs and analyze the advice complexity of getting an optimal solution. We give almost tight lower and upper bounds for the [Image: see text] , where there is one forbidden induced subgraph that may or may not be disconnected and tight bounds on the [Image: see text] , where we have an arbitrary number of forbidden connected graphs. For the latter result we present an algorithm that computes the advice complexity directly from [Formula: see text]. For the [Image: see text] the advice complexity is basically an easy function of the size of the biggest component in H.


title: Rapprochement amid readjustment: how China sees issues and trends in its changing relationship with the EU

text: The EU-China relationship is entering a period of readjustment. On the one hand, the US-China trade war has forced China to seek closer alignment with the EU, and on the other hand, the EU has chosen a more proactive approach to tame China’s global and regional assertiveness. The European readjustment has been particularly noticeable in areas like connectivity, investment and 5G. China has noticed the European change of attitude and relates it to European uncertainties and misinterpretation of China’s development. While the new European leadership was supposed to meet their Chinese counterparts in 2020 and work out a new modus operandi, the global coronavirus pandemic has exacerbated underlying tensions in the relationship. A comprehensive deepening of the EU-China strategic partnership looks unlikely and cooperation is expected to be increasingly selective.


Weltweite gesundheitspolitische Herausforderung


Pandemic underpins need for SOAR


Service improvement in public sector operations – A European comparative analysis


Wolbachia, a bacterium fighting on our side


The impact of life experiences on risk taking


Reproducibility in science: important or incremental?


Massimo Galli


title: Desmi hit by cyber-attack

text: Denmark's Desmi A/S suffered a cyber-attack in the week before Easter, with the attackers requesting a ransom for data recovery.


The mask (which we need so much is the one we would have needed)()()


Medicina Nuclear en la pandemia por COVID-19()


Asahi Kasei Corp, Japan


Larisa Rudenko


People & Appointments


DVOM: Deutscher Verband Für Osteopathische Medizin e.V.


VaOS: Vereinigung akademischer Osteopathlnnen Schweiz


hpO: Berufsvereinigung für heilkundlich praktizierte Osteopathie e.V.


COVID-19: Es el momento de estar más unidos que nunca()


To masks, citizen!


DGOM: Deutsche Gesellschaft für Osteopathische Medizin e.V.


Lessons in flexibility from a general surgery program at the epicenter of the pandemic in New York City


title: Letter to the Editor: Comment on GLP-1-based drugs and COVID-19 treatment

text: • GLP-1R is abundantly expressed in lung epithelia and certain immune cells. • GLP-1 based drugs show “therapeutic effects” in acute and chronic lung injury models. • Clinical trial is designed in testing effect of GLP-1 analogues in treating Covid-19. • Retrospective studies should be conducted in T2D subject with Covid-19.


Telemedicine applied to cardiovascular and neurovascular diseases during containment


Donaldson Co Inc, USA


Resumption of leisure sports after release from containment


title: The not-so-blue jays

text: Watching birds is great entertainment, and there's fascinating physics behind how some get their colours, says Chanda Prescod-Weinstein


The Anales de Pediatría editors annual report()


A note from the editor


title: Overcoming nonstructural protein 15-nidoviral uridylate-specific endoribonuclease (nsp15/NendoU) activity of SARS-CoV-2

text: COVID-19 has become the gravest global public health crisis since the Spanish Flu of 1918. Combination antiviral therapy with repurposed broad-spectrum antiviral agents holds a highly promising immediate treatment strategy, especially given uncertainties of vaccine efficacy and developmental timeline. Here, we describe a novel hypothetical approach: combining available broad-spectrum antiviral agents such as nucleoside analogs with potential inhibitors of NendoU, for example nsp15 RNA substrate mimetics. While only hypothesis-generating, this approach may constitute a ‘double-hit’ whereby two CoV-unique protein elements of the replicase–transcriptase complex are inhibited simultaneously; this may be an Achilles' heel and precipitate lethal mutagenesis in a coronavirus. It remains to be seen whether structurally optimized RNA substrate mimetics in combination with clinically approved and repurposed backbone antivirals can synergistically inhibit this endonuclease in vitro, thus fulfilling the ‘double-hit hypothesis’.


Elk nadeel heeft zijn voordeel


A big disparity between the demand and supply of Hand Surgeons in India


The health-related determinants of politics


Towards more balanced representation in Lancet Commissions


Virus infiziert die Kreditwirtschaft


Danke sagen


Pandemie holt die Hypovereinsbank ein


"Die Pandemie ist eine Naturkatastrophe"


Special | Trends


Die Krise kommt mit Wucht


Soziale Distanz beschleunigt digitale Dienstleistungen


title: Lithium and coronaviral infections. A scoping review.

text: The current rapid spread of the novel coronavirus (SARS-CoV-2) causing coronavirus disease 2019 (COVID-19) calls for a rapid response from the research community. Lithium is widely used to treat bipolar disorder, but has been shown to exhibit antiviral activity. This brief review took a systematic approach to identify six in vitro studies reporting on the influence of lithium on coronaviral infections. We propose mechanistic investigation of the influence of lithium - alone and with chloroquine - on the SARS-CoV-2 infection.


title: The promises and pitfalls of polysemic ideas: ‘One Health’ and antimicrobial resistance policy in Australia and the UK

text: Recent scholarship posits that ambiguous (‘polysemic’) ideas are effective for coalition building between diverse stakeholders: their capacity to be interpreted differently attracts different interests. Hence, in search of political solutions to ‘wicked’ and similarly complex problems, deploying polysemic ideas would be critical to effective policy-making. This paper scopes the policy-making potential of polysemic ideas by examining the impact of an ambiguous concept known as ‘One Health’ on responses to antimicrobial resistance (AMR) in Australia and the UK. It offers two primary arguments. Firstly, polysemic ideas can help mobilise broad attention to complex problems: since One Health became associated with AMR, political and administrative attention has grown more intense and coordinated than previously. Secondly, however, a polysemic idea alone may be insufficient to generate effective action: the contrast between Australian and UK AMR policies illustrates that polysemic ideas do not suspend interests, institutions, or ideas that can be readily deployed. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (10.1007/s11077-020-09390-3) contains supplementary material, which is available to authorised users.


title: Canadians Think that Nearly All of Us Will Be Allowed Back to Work around August

text: Business closures and work-from-home orders have been a central part of Canada's plan to slow the spread of COVID-19. The success of these measures hinges on public support, which cannot be taken for granted as the orders induce considerable economic pain. As governments consider when to re-open the economy, one relevant variable is when the public expects the economy to re-open. At minimum, if public perceptions differ from government plans then additional government messaging is required to better align expectations.


What’s new about pulmonary hyperinflation in mechanically ventilated critical patients


title: The interplay of entrepreneurial and non-entrepreneurial internationalization: an illustrative case of an Italian SME

text: This study describes SME internationalization as a process that combines entrepreneurial and non-entrepreneurial behaviour. We bring in insights from prior literature and use an illustrative case study of an Italian SME to demonstrate the interplay of entrepreneurial and non-entrepreneurial behaviour during the internationalization process. Our study shows that the combination of entrepreneurial and non-entrepreneurial internationalization cannot be fully explained with existing International Entrepreneurship literature or other internationalization theories, as they do not take into account the nonlinear nature of internationalization or explain why the process seems to reach a ‘glass ceiling’ beyond which it does not progress. The study concludes with a conceptual framework providing an alternative explanation. Based on our conceptual reasoning we propose that predominantly non-entrepreneurial internationalization can occur without developing a clearly defined internationalization strategy. Additionally, we argue that low commitment to internationalization prevents capability development and may lead to nonlinear internationalization. Furthermore, we suggest that family involvement may moderate a firm’s international entrepreneurial orientation, consequently leading to more non-entrepreneurial internationalization.


Patient portal reminders have little impact on influenza vaccination rate


title: Dynamic Network Slicing: Challenges and Opportunities

text: Network Slicing (NS) is an evolving area of research, performing a logical arrangement of resources to operate as individual networks, hence allowing for massively customizable service and tenant requirements. NS, via the respective network architecture can enable an effective deployment of 5G networks and support a great variety of emerging use cases and/or related services. In this scope and with the aim of extending all potential network and service benefits, the concept of dynamic NS becomes a prominent feature of 5G allowing for connectivity and data processing tailored to specific customers’ requirements. We discuss several essential features and fundamental designing principles that can affect the realization of a reliable dynamic NS, capable of serving an immense multiplicity of 5G-based innovations, towards structuring a fully mobile and inclusive society. Furthermore, due to its context, dynamic NS can support digital transformation and mobilization of industry vertical customers, implicating for significant commercial potential. To this aim, we also discuss related perspectives for market growth coming from proposed business models, together with regulatory concerns that could affect future growth of dynamic NS.


title: RDF Reasoning on Large Ontologies: A Study on Cultural Heritage and Wikidata

text: Large ontologies are available as linked data, and they are used across many domains, but to process them considerable resources are required. RDF provides automation possibilities for semantic interpretation, which can lower the effort. We address the usage of RDF reasoning in large ontologies, and we test approaches for solving reasoning problems, having in mind use cases of low availability of computational resources. In our experiment, we designed and evaluated a method based on a reasoning problem of inferring Schema.org statements from cultural objects described in Wikidata. The method defines two intermediate tasks that reduce the volume of data used during the execution of the RDF reasoner, resulting in an efficient execution taking on average 10.3 ± 7.6 ms per RDF resource. The inferences obtained in the Wikidata test were analysed and found to be correct, and the computational resource requirements for reasoning were significantly reduced. Schema.org inference resulted in at least one rdf:type statement for each cultural resource, but the inference of Schema.org predicates was below expectations. Our experiment on cultural data has shown that Wikidata contains alignment statements to other ontologies used in the cultural domain, which with the application of RDF and OWL reasoning can be used to infer views of Wikidata expressed in cultural domain’s data models.


title: PolicyCLOUD: Analytics as a Service Facilitating Efficient Data-Driven Public Policy Management

text: While several application domains are exploiting the added-value of analytics over various datasets to obtain actionable insights and drive decision making, the public policy management domain has not yet taken advantage of the full potential of the aforementioned analytics and data models. Diverse and heterogeneous datasets are being generated from various sources, which could be utilized across the complete policies lifecycle (i.e. modelling, creation, evaluation and optimization) to realize efficient policy management. To this end, in this paper we present an overall architecture of a cloud-based environment that facilitates data retrieval and analytics, as well as policy modelling, creation and optimization. The environment enables data collection from heterogeneous sources, linking and aggregation, complemented with data cleaning and interoperability techniques in order to make the data ready for use. An innovative approach for analytics as a service is introduced and linked with a policy development toolkit, which is an integrated web-based environment to fulfil the requirements of the public policy ecosystem stakeholders.


title: Improving Movie Recommendation Systems Filtering by Exploiting User-Based Reviews and Movie Synopses

text: This paper addresses the subject of Movie Recommendation Systems, focusing on two of the most well-known filtering techniques, Collaborative Filtering and Content-based Filtering. The first approach proposes a supervised probabilistic Bayesian model that forms recommendations based on the previous evaluations of other movies the user has watched. The second approach composes an unsupervised learning technique that forms clusters of users, using the K-Means algorithm, based on their preference of different movie genres, as it is expressed through their ratings. Both of the above approaches are compared to each other as well as to a basic method known as Weighted Sum, which makes predictions based on the cosine similarity and the euclidean distance between users and movies. In addition, Content-based Filtering is implemented through K-Means clustering techniques that focus on identifying the resemblance between movie plots. The first approach clusters movies according to the Tf/Idf weighting scheme, applying weights to the terms of movie plots. The latter identifies the likeness between movie plots, utilizing the BM25 algorithm. The efficiency of the above methods is calculated through the Accuracy metric.


title: Boosted Ensemble Learning for Anomaly Detection in 5G RAN

text: The emerging 5G networks promises more throughput, faster, and more reliable services, but as the network complexity and dynamics increases, it becomes more difficult to troubleshoot the systems. Vendors are spending a lot of time and effort on early anomaly detection in their development cycle and majority of the time is spent on manually analyzing system logs. While main research in anomaly detection uses performance metrics, anomaly detection using functional behaviour is still lacking in depth analysis. In this paper we show how a boosted ensemble of Long Short Term Memory classifiers can detect anomalies in the 5G Radio Access Network system logs. Acquiring system logs from a live 5G network is difficult due to confidentiality issues, live network disturbance, and problems to repeat scenarios. Therefore, we perform our evaluation on logs from a 5G test bed that simulate realistic traffic in a city. Our ensemble learns the functional behaviour of an application by training on logs from normal execution time. It can then detect deviations from normal behaviour and also be retrained on false positive cases found during validation. Anomaly detection in RAN shows that our ensemble called BoostLog, outperforms a single LSTM classifier and further testing on HDFS logs confirms that BoostLog also can be used in other domains. Instead of using domain experts to manually analyse system logs, BoostLog can be used by less experienced trouble shooters to automatically detect anomalies faster and more reliable.


title: Opinion Mining of Consumer Reviews Using Deep Neural Networks with Word-Sentiment Associations

text: Automated opinion mining of consumer reviews is becoming increasingly important due to the rising influence of reviews on online retail shopping. Existing approaches to automated opinion classification rely either on sentiment lexicons or supervised machine learning. Deep neural networks perform this classification task particularly well by utilizing dense document representation in terms of word embeddings. However, this representation model does not consider the sentiment polarity or sentiment intensity of the words. To overcome this problem, we propose a novel model of deep neural network with word-sentiment associations. This model produces richer document representation that incorporates both word context and word sentiment. Specifically, our model utilizes pre-trained word embeddings and lexicon-based sentiment indicators to provide inputs to a deep feed-forward neural network. To verify the effectiveness of the proposed model, a benchmark dataset of Amazon reviews is used. Our results strongly support integrated document representation, which shows that the proposed model outperforms other existing machine learning approaches to opinion mining of consumer reviews.


title: Application and Algorithm: Maximal Motif Discovery for Biological Data in a Sliding Window

text: Since the discovery of motifs in molecular sequences for real genomic data, research into this phenomenon has attracted increased attention. Motifs are relatively short sequences that are biologically significant. This paper utilises the bioinformatics application of the algorithm outlined in [5], testing it using real genomic data from large sequences. It intends to implement bioinformatics application for real genomic data, in order to discover interesting regions for all maximal motifs, in a sliding window of length ℓ, on a sequence x of length n.


title: Sentiment Analysis on Movie Scripts and Reviews: Utilizing Sentiment Scores in Rating Prediction

text: In recent years, many models for predicting movie ratings have been proposed, focusing on utilizing movie reviews combined with sentiment analysis tools. In this study, we offer a different approach based on the emotionally analyzed concatenation of movie script and their respective reviews. The rationale behind this model is that if the emotional experience described by the reviewer corresponds with or diverges from the emotions expressed in the movie script, then this correlation will be reflected in the particular rating of the movie. We collected a dataset consisting of 747 movie scripts and 78.000 reviews and recreated many conventional approaches for movie rating prediction, including Vector Semantics and Sentiment Analysis techniques ran with a variety of Machine Learning algorithms, in order to more accurately evaluate the performance of our model and the validity of our hypothesis. The results indicate that our proposed combination of features achieves a notable performance, similar to conventional approaches.


title: Indoor Localization with Multi-objective Selection of Radiomap Models

text: Over the last years, Indoor Localization Systems (ILS) evolved, due to the inability of Global Positioning Systems (GPS) to localize in indoor environments. A variety of studies tackle indoor localization with technologies such as Bluetooth Beacons and RFID that require costly installation, or techniques such as Google Wi-Fi/Cell DB and fingerprinting that leverage from the already existing Wi-FI and telecommunication infrastructure. Additionally, recent studies attempt to solve the same problem using Bio-Inspired techniques, such as Artificial Neural Networks (ANNs) and Deep Neural Networks (DNN). In this paper, we introduce a Multi-Objective Optimization Radiomap Modelling (MOO-RM) based ILS. The MOO-RM ILS divides the dataset into clusters using a K-Means algorithm and trains ANN models on the data of each cluster. The resulting models are fed into a Multi-Objective Evolutionary Algorithm based on Decomposition (MOEA/D), which minimizes the required storage space and the localization error, simultaneously. Our experimental studies demonstrate the superiority of the proposed approach on real datasets of Wi-Fi traces with respect to various existing techniques.


title: Real-Time Prediction of Online Shoppers’ Purchasing Intention Using Random Forest

text: In this paper, we suggest a real-time online shopper behavior prediction system which predicts the visitor’s shopping intent as soon as the website is visited. To do that, we rely on session and visitor information and we investigate naïve Bayes classifier, C4.5 decision tree and random forest. Furthermore, we use oversampling to improve the performance and the scalability of each classifier. The results show that random forest produces significantly higher accuracy and F1 Score than the compared techniques.


title: Tensor-Based CUDA Optimization for ANN Inferencing Using Parallel Acceleration on Embedded GPU

text: With image processing, robots acquired visual perception skills; enabling them to become autonomous. Since the emergence of Artificial Intelligence (AI), sophisticated tasks such as object identification have become possible through inferencing Artificial Neural Networks (ANN). Be that as it may, Autonomous Mobile Robots (AMR) are Embedded Systems (ESs) with limited on-board resources. Thus, efficient techniques in ANN inferencing are required for real-time performance. This paper presents the process of optimizing ANNs inferencing using tensor-based optimization on embedded Graphical Processing Unit (GPU) with Computer Unified Device Architecture (CUDA) platform for parallel acceleration on ES. This research evaluates renowned network, namely, You-Only-Look-Once (YOLO), on NVIDIA Jetson TX2 System-On-Module (SOM). The findings of this paper display a significant improvement in inferencing speed in terms of Frames-Per-Second (FPS) up to 3.5 times the non-optimized inferencing speed. Furthermore, the current CUDA model and TensorRT optimization techniques are studied, comments are made on its implementation for inferencing, and improvements are proposed based on the results acquired. These findings will contribute to ES developers and industries will benefit from real-time performance inferencing for AMR automation solutions.