*Article* **Experimental Study on Seismic Behavior of Steel Frames with Infilled Recycled Aggregate Concrete Shear Walls**

#### **Lijian Sun 1,2, Hongchao Guo 1,2,\* and Yunhe Liu 1,2**

Received: 16 October 2019; Accepted: 4 November 2019; Published: 5 November 2019

**Abstract:** Experiments were performed on four specimens of steel frames with infilled recycled aggregate concrete shear walls (SFIRACSWs), one specimen of infilled ordinary concrete wall, and one pure-steel frame were conducted under horizontal low cyclic loading. The influence of the composite forms of steel frames and RACSWs (namely, infilled cast-in-place and infilled prefabricated) on the failure modes, transfer mechanisms of lateral force, bearing capacity, and ductility of SFIRACSWs is discussed, and the concrete type and connecting stiffness of beam–column joints (BCJs) are also considered. Test results showed that infilled RACSWs can increase the bearing capacity and lateral stiffness of SFIRACSWs. The connecting stiffness of BCJs slightly influences the seismic behavior of SFIRACSWs. In the infilled cast-in-place RACSWs, the wall cracks mainly extended along the diagonal direction. The bearing capacity was 2.4 times higher than in the pure steel frame, the initial stiffness was 4.3 times higher, and the displacement ductility factors were 2.44–2.69 times higher. In the infilled prefabricated RACSWs, the wall cracks mainly extended along the connection between the embedded T-shape connectors and walls before finally connecting along the horizontal direction. Moreover, shear failure occurred in the specimens. The bearing capacity was 1.44 times higher than that of the pure steel frame, the initial stiffness was 2.8 times higher, and the displacement ductility factors were 3.32–3.40 times higher. The degradation coefficients of the bearing capacity were more than 0.85, indicating that the specimens demonstrated a high safety reserve.

**Keywords:** steel frame; infilled shear walls; recycled aggregate concrete; semi-rigid connection; seismic behavior


*Alginate-Based Applications in Biotechnology with a Special Mention to Biosensors DOI: http://dx.doi.org/10.5772/intechopen.110737*

preserving the structure and conformation of the enzyme. These requirements have led to the development a hetero-functional immobilisation matrix, which can offer multi-point stabilisation of the immobilised species. Alginate contains carboxyl and hydroxyl functional groups, which can facilitate the conjugation and stabilisation of biomolecules. Moreso, via the hybrid approach, more functionalities can be introduced to the alginate for additional stabilisation.

Thiol, epoxy, and glyoxal group-containing immobilisation support matrices are documented to exhibit excellent biomolecular immobilisation and stabilisation capacity. Preparation of alginate composite with such hetero functionalities holds the prospect for exponential advancement of the application of alginate in industrial, biotechnological, and medical contexts. Thus, alginate and its derived composites hold a high prospect for the co-immobilisation and co-localisation of cells [175] and other biological payloads with emerging biotechnological uses.


*Article* **Comparison of Financial Models for Stock Price Prediction**

### **Mohammad Rafiqul Islam and Nguyet Nguyen \***

Department of Mathematics and Statistics, Youngstown State University, Youngstown, OH 44555, USA<EMAIL_ADDRESS>
**\*** Correspondence<EMAIL_ADDRESS>Tel.: +1-330-941-1805

Received: 30 July 2020; Accepted: 12 August 2020; Published: 14 August 2020

**Abstract:** Time series analysis of daily stock data and building predictive models are complicated. This paper presents a comparative study for stock price prediction using three different methods, namely autoregressive integrated moving average, artificial neural network, and stochastic process-geometric Brownian motion. Each of the methods is used to build predictive models using historical stock data collected from Yahoo Finance. Finally, output from each of the models is compared to the actual stock price. Empirical results show that the conventional statistical model and the stochastic model provide better approximation for next-day stock price prediction compared to the neural network model.

**Keywords:** stock price prediction; auto-regressive integrated moving average; artificial neural network; stochastic process-geometric Brownian motion; financial models


*5.2.1. Single model*

The full dataset is used for this analysis. There is a total number of 17 features, which are Xminutes, Yminutes, %red, %orange, relative humidity, precipitation, pressure, solar radiation, temperature, wind Speed, Xwind, Ywind, CO, NO2 , O3 , SO2 , PM2.5 (= feature to predict).

The linear regression model obtained after running the algorithm is as follows:

The prediction accuracy of the model is evaluated as

$$\mathbf{r} \qquad \qquad = \mathbf{0.81}$$


**2. Photodecomposition: kinetics and process parameters**

The heterogeneous photocatalysis shows a strong dependence on the operating temperature. The kinetics is usually dependent on the first step of the adsorption and the equilibrium modeled by Langmuir isotherms and Langmuir-Hinshelwood model. The first pseudo-order usually appears at the beginning of the reaction, just in the initial steps. As the reaction proceeds, the intermediate production could interfere with the radiation incidence. The observed decomposition rates as the pollutant start to decompose and begin the competition for the adsorption sites between the pollutants and the adsorbed species. The initial pollutant concentration starts to be the limiting reactant with mass transfer limitations with no kinetic control for lower concentrations.

The increase of the catalyst mass promotes the photodegradation rate and the active catalyst sites. If the system is a slurry, the reaction rate reaches a maximum or optimal value and after that declines. The higher suspended particle concentration enhances the light scattering, the particle agglomeration, with light opacity enhancement, and after a certain point, the photodecomposition efficiency decreases. There is an equilibrium between the available surface site and the suspended particles control.

The oxygen plays a vital role in the photodecomposition reactions; dissolved O2 reacts with the photogenerated electrons leading to O2 − radicals and preventing the recombination of the generated e− and the h+ pairs. The comparison between the kinetics of the air-saturated solutions and the pure oxygen solution often results in smaller rates for the first.

The pH values influence the catalyst aggregations and its surface charges, with the valence band (VB) and conduction band (CB) position. At low pH values, the CB holes are more effective in comparison with VB. The change in the pH values allows the surface charge modification mostly when the amphoteric groups are present [5].

The adsorption equilibrium after decomposition depends on the pollutant pH speciation and the reactive species. Considering the low pH values, the h+ can be the more oxidizing species, the amount of ˙OH increases under alkaline conditions when the OH− ions are available to react with h+ , and the ˙OH become the primary oxidant (Eqs. (1) and (2)). This effect increases the ˙OH availability at higher pH values in spite of the negatively charged catalyst surface and also the pollutant repelling action at such pH values; the ˙OH radicals' attack can explain the pH medium behavior.

$$\text{(M - OH)}\text{surface} + \text{H}^+ <= > \text{(M - OH}\_2^{\cdot \cdot}\text{)}\text{surface} \tag{1}$$

$$\text{(M - OH)}\text{surface} + \text{OH}^- <= > \text{(M - O}^-\text{)}\text{ surface} + \text{H}\_2\text{O}\tag{2}$$

The presence of some anions like chloride, nitrate, and sulfate reduces the photocatalytic performance as a result of the competition for the adsorption sites to scavenge the ˙OH radicals. Natural organic matter and humic acids are scavengers of the reactive species and usually show negative photodegradation influence. Nevertheless, the presence of the carbonate and bicarbonate increases photodecomposition efficiency.

The temperature has a limited effect in the photodecomposition efficiency until 80 Cº; after that there is the tendency to reduce the photocatalytic efficiency as a result of lower oxygen solubility in water. Different temperatures can also promote intermediaries and by-product formation.


Perfect Signal Transmission Using Adaptive Modulation and Feedback

*Anatoliy Platonov*

### **Abstract**

The research results show that adaptive adjusting of modulators over feedback enables development of the "perfect" communication system (CS) transmitting analog and digital signals in real-time without coding with a bit rate equal to the forward channel capacity and limit energy spectral efficiency. These and other feasibilities unattainable for known CS are the result of transition from the direct transmission of samples of the input signal to the transmission of sequences of their estimation errors cyclically formed at the input of forward transmitter (FT) modulator. Each transmitted error is formed as a difference between the value of input sample and its current estimate computed in the receiver in previous cycle and delivered to FT over feedback. Growing accuracy of estimates decreases estimation errors and permits their transmission permanently increasing the modulation index and maximizing the amount of information delivered to the receiver. Unlike CS with coding, adaptive feedback CS (AFCS) can be optimized using Bayesian estimation and information theory. Absence of coders simplifies the construction of FT and reduces their energy consumption and cost. Moreover, adaptive properties of AFCS permit to maintain the perfect mode of transmission in every scenario of application. The chapter presents analytical backgrounds, experiments results and research genesis including the reasons for absence of AFCS in modern communications.

**Keywords:** wireless, adaptive modulation, feedback, Bayesian optimization, perfect transmission, limit energy-spectral efficiency, channel capacity, Shannon's limits

#### **1. Introduction**

The publication of Shannon's fundamental works [1, 2] coincided with the appearance of the first computers and urgent need for the development of fast and reliable channels for digital data transmission. Shannon's theory led to the almost immediate development of backgrounds of the coding and digital CS theory. The parallel fast development of high-resolution AD-DA converters and digital technologies made digitizing and coding the basic principle of signal transmission.

The side effect of the successes of digital CS was initial lack of interest in CS with feedback channels (FCS) and codeless signals transmission, although this possibility was noted by Shannon in [1, 2]. The first work of Elias [3] in this direction was published seven years later, in 1956. The results of the work showed that ideal feedback channel and proper setting of the modulation gains permit to transmit

analog signals without coding in real time with the limit bit rate equal to the capacity of the forward channel—the result unfeasible in digital CS with coding. Moreover, the absence of coders radically simplified the construction of FCS transmitters. Initially not noticed, this work initiated a great cycle of research in the optimization of FCS (see e.g. [4–13]) carried out in 1960s in MIT, Bell Lab., Stanford University, NASA, and other research centres. The results of these investigations unambiguously confirmed that modulation and feedback enable a development of simple CS transmitting signals and short codes in real time perfectly and with minimal distortion. Moreover, analytical results of the research determined a way to design of the perfect FCS design.

networks is still relevant to the field of wireless communications? … any improvements are expected to be marginal [19]." Similar evaluations of the state of theory

Analysis of the sources of problems showed that the main reason is the lack of efficient theoretical basis permitting one to investigate the behavior of wireless CS in different scenarios and to choose the versions best suited to the goals of the

In the following sections of the chapter, we discuss these problems and their solution. To simplify the discussion, apart from CS and FCS, we use the following abbreviations: CSC—communication system with coding and AFCS—adaptive feedback communication system transmitting signals over the forward channels (FT) using analog modulators (AMs) adjusted by the controls formed in BSt and

Let us clarify the subject of discussion. The term "performance", relatively new in communications, is broader than the term "quality". Furthermore, the evaluation of CS performance has its own groups of the criteria used to compare the systems by their general utility characteristics, further called the "performance" criteria. Another, relatively narrow and stable group of "analytical" criteria is used in the research as a tool permitting to improve one or a part of the performance criteria.

The performance criteria determine the required, desired, or real characteristics of the future or existing wireless CS permitting to use these systems for solution of definite tasks in the given conditions, and to evaluate the corresponding benefits,

• resistance to industrial disturbances and changes in the environment

• possibility of supplying from renewable energy sources

**2. Sources of difficulties in improvement of short-range CS**

costs, and risks [16]. The main criteria of this group are:

• frequency range and channel bandwidth

• design, production, and deployment costs

• size, weight, price, and other characteristics.

• power and energy consumption

can be found in [20–22] and other works.

*DOI: http://dx.doi.org/10.5772/intechopen.90516*

*Perfect Signal Transmission Using Adaptive Modulation and Feedback*

delivered to FT over feedback channels.

project.

**performance**

**2.1 Basic performance criteria**

• range of reliable transmission

• data rate and throughput

• security of transmission

• interference and coexistence

• latency

**3**

However, since the mid-1970s, interest in the research in the FCS theory sharply declined, and, during subsequent decades, only a small number of academic papers were published. The main reason was the lack of practical results, as well as a pessimistic evaluation of the entire direction of research ("The subject itself seems to be a burned out case" [14], p. 324). It is worth adding that, at that time, shortrange transmission was provided by wires, and there was no special need in wireless FCS. At the same time, development of digital technologies, communications and automatics generated a lot of complex theoretical tasks, and the industry required specialists. As a result, most FCS researchers took up these tasks.

The situation changed with the appearance of mobile communications and wireless networks (WN) containing a great number of wireless end nodes (EN), each communicating with the base station (BSt) over forward and feedback channels. This renewed interest in FCS was still, however, strictly academic [15] and without any practical results. Having no alternative, currently, all the channels of WN employ only the coding principle of transmission.

Apart from the traditional requirements for CS (maximal rate, quality, reliability, range of transmission, etc.), battery-supplied or battery-less low-power transmitters of EN should be minimally complex and minimally energy-consuming, and should satisfy a large number of the other, sufficiently rigorous requirements [16] such as maximal energy efficiency of transmission, optimal utilization of the channel bandwidth, reduction of inter-channel interference, security of transmission, and others. The set of these characteristics is now defined by the general term "performance," and the main task of designers is the improvement of the systems or channels' performance.

The development of the first generations of WN and corresponding FT did not cause any particular difficulties, but each subsequent generation does pose new, increasingly complex problems. One should stress that the performance of the lower, physical (PHY) layer channels EN-BSt dramatically influences the performance of the overall network regardless of the particularities of the higher layers' organization.

The design of the PHY layer channels is carried out almost independently from that of the higher layers and software of WN, and requires thorough knowledge of mathematics, signals processing, communication and information theory, and so on. Nevertheless, even among experienced designers, "the task of changing from a cable to wireless is still seen as a daunting prospect; wireless retains its reputation of being close to black magic. For most designers, it is an area where they have very little ability to change anything, other than the output power" [16]. A similar sentiment is expressed in [17].

This is not an isolated opinion. A large number of recent publications question the capability of the modern theory to provide any noticeable improvement in wireless transmission: "Shannon limit is now routinely being approached within 1 dB on AWGN channels … So is coding theory finally dead? … there is little more to be gained in terms of performance [18]"; "Whether research at the physical layer of *Perfect Signal Transmission Using Adaptive Modulation and Feedback DOI: http://dx.doi.org/10.5772/intechopen.90516*

networks is still relevant to the field of wireless communications? … any improvements are expected to be marginal [19]." Similar evaluations of the state of theory can be found in [20–22] and other works.

Analysis of the sources of problems showed that the main reason is the lack of efficient theoretical basis permitting one to investigate the behavior of wireless CS in different scenarios and to choose the versions best suited to the goals of the project.

In the following sections of the chapter, we discuss these problems and their solution. To simplify the discussion, apart from CS and FCS, we use the following abbreviations: CSC—communication system with coding and AFCS—adaptive feedback communication system transmitting signals over the forward channels (FT) using analog modulators (AMs) adjusted by the controls formed in BSt and delivered to FT over feedback channels.


**Diarrhea: for diarrhea, they need to:**

*Nutrition and HIV/AIDS - Implication for Treatment, Prevention and Cure*

vitamins and minerals which should be added in the diet include:

and fruits including liver, whole eggs, and milk

tions should be seriously considered [30–32].

**2.2 Vitamins and minerals**

and green leafy vegetables

• Vitamin C, from citrus fruits

calcium supplements could be taken in the diet.

that HIV persons need to control: **Nausea and vomiting:**

• Eat smaller meals every 1–2 hours.

• Drink ginger tea or ginger ale or ginger.

• Eat more cold foods and less hot foods.

• Rest after meals, but not to lie down flat.

• Receive medications for nausea.

*2.2.1 Nutrition and HIV: coping with special problems*

To manage nausea and vomiting, they need to:

• Avoid greasy or spicy foods, or foods with strong odors.

will be used as a source of energy like other fats. Assuming HIV-positive individuals have no opportunity of eating fatty fish or seafood, taking omega-3 supplement to improve both physical and mental health as well as reduce the risk of disease infec-

Vitamins and minerals regulate body processes and so people who are HIVpositive need extra vitamins and minerals in the diet to repair and heal damaged cells. They need extra vitamins and minerals to boost the immune system. These

• Vitamin A and beta-carotene, from dark green, yellow, orange, or red vegetables

• Vitamin B, from meat, fish, chicken, grains, nuts, white beans, avocados, broccoli

• Vitamin E, from green leafy vegetables, peanuts and vegetable oils

• Selenium, from whole grains, nuts, poultry, fish, eggs and peanut butter

• Zinc, from meat, poultry, fish, beans, peanuts, and milk and other dairy products

Because of the difficulty for HIV-positive persons in getting enough of all the nutrients needed for optimal health from foods, it is recommended that a multivitamin/mineral tablet (without extra iron) but containing 100% of the recommended daily allowance (RDA) should be taken. If at least three servings of high-calcium food such as green leafy vegetables or dairy foods are not eaten on daily basis,

HIV-positive persons could have a variety of reactions including side effects from ART medications which should be managed. Here are some of the problems

• Eat bland, low-fat foods, such as plain pasta, canned fruit, or plain broth.

**72**