title:
Interactive Traceability Querying and Visualization for Coping With
  Development Complexity

abstract:
  Requirements traceability can in principle support stakeholders coping with
rising development complexity. However, studies showed that practitioners
rarely use available traceability information after its initial creation. In
the position paper for the Dagstuhl seminar 1242, we argued that a more
integrated approach allowing interactive traceability queries and
context-specific traceability visualizations is needed to let practitioner
access and use valuable traceability information. The information retrieved via
traceability can be very specific to a current task of a stakeholder,
abstracting from everything that is not required to solve the task.


title: Exploring Quantum Contextuality to Generate True Random Numbers

abstract:
  Random numbers represent an indispensable resource for many applications. A
recent remarkable result is the realization that non-locality in quantum
mechanics can be used to certify genuine randomness through Bell's theorem,
producing reliable random numbers in a device independent way. Here, we explore
the contextuality aspect of quantum mechanics and show that true random numbers
can be generated using only single qutrit (three-state systems) without
entanglement and non-locality. In particular, we show that any observed
violation of the Klyachko-Can-Binicioglu-Shumovsky (KCBS) inequality [Phys.
Rev. Lett. 101, 20403 (2008)] provides a positive lower bound on genuine
randomness. As a proof-of-concept experiment, we demonstrate with photonic
qutrits that at least 5246 net true random numbers are generated with a
confidence level of 99.9%.


title:
Possible quantum phase-manipulation of a two-leg ladder in
  mixed-dimensional fermionic cold atoms

abstract:
  The recent realization of mixed-dimensional systems of cold atoms has
attracted much attention from both experimentalists and theorists. Different
effective interactions and novel correlated quantum many-body phases may be
engineered in these systems, with the different phases being tunable via
external parameters. In this article we investigate a two-species Fermi atom
mixture: one species of atom exists in two hyperfine states and is confined to
move in a two-leg ladder, interacting with an on-site interaction, and the
other moves freely in a two dimensional square lattice that contains the
two-leg ladder. The two species of atoms interact via an on-site interaction on
the ladder. In the limit of weak inter-species interactions, the
two-dimensional gas can be integrated out, leading to an effective long-range
mediated interaction in the ladder, generated by to the on-site inter-species
interaction. We show that the form of the mediated interaction can be
controlled by the density of the two-dimensional gas and that it enhances the
charge density wave instability in the two-leg ladder after the renormalization
group transformation. Parameterizing the phase diagram with various
experimentally controllable quantities, we discuss the possible tuning of the
macroscopic quantum many-body phases of the two-leg ladder in this
mixed-dimensional fermionic cold atom system.


title: Electromagnetic Wave Source Conditions

abstract:
  This chapter discusses the relationships between current sources and the
resulting electromagnetic waves in FDTD simulations. First, the
"total-field/scattered-field" approach to creating incident plane waves is
reviewed and seen to be a special case of the well-known principle of
equivalence in electromagnetism: this can be used to construct "equivalent"
current sources for any desired incident field, including waveguide modes. The
effects of dispersion and discretization are discussed, and a simple technique
to separate incident and scattered fields is described in order to compensate
for imperfect equivalent currents. The important concept of the local density
of states (LDOS) is reviewed, which elucidates the relationship between current
sources and the resulting fields, including enhancement of the LDOS via mode
cutoffs (Van Hove singularities) and resonant cavities (Purcell enhancement).
We also address various other source techniques such as covering a wide range
of frequencies and incident angles in a small number of simulations for waves
incident on a periodic surface, sources to excite eigenmodes in rectangular
supercells of periodic systems, moving sources, and thermal sources via a Monte
Carlo/Langevin approach.


title: Constraints on relativity violations from gamma-ray bursts

abstract:
  Tiny violations of the Lorentz symmetry of relativity and the associated
discrete CPT symmetry could emerge in a consistent theory of quantum gravity
such as string theory. Recent evidence for linear polarization in gamma-ray
bursts improves existing sensitivities to Lorentz and CPT violation involving
photons by factors ranging from ten to a million.


title: Variability in Optical Spectra of epsilon Orionis

abstract:
  We present the results of a time-series analysis of 130 echelle spectra of
epsilon Ori (B0 Ia), acquired over seven observing seasons between 1998 and
2006 at Ritter Observatory. The equivalent widths of Halpha (net) and He I 5876
were measured and radial velocities were obtained from the central absorption
of He I 5876. Temporal variance spectra (TVS) revealed significant wind
variability in both Halpha and He I 5876. The He I TVS have a double-peaked
profile consistent with radial velocity oscillations. A periodicity search was
carried out on the equivalent width and radial velocity data, as well as on
wavelength-binned spectra. This analysis has revealed several periods in the
variability with time scales of 2-7 d. Many of these periods exhibit sinusoidal
modulation in the associated phase diagrams. Several of these periods were
present in both Halpha and He I, indicating a possible connection between the
wind and the photosphere. Due to the harmonic nature of these periods, stellar
pulsations may be the origin of some of the observed variability. Periods on
the order of the rotational period were also detected in the He I line in the
98-99 season and in both lines during the 04-05 season. These periods may
indicate rotational modulation due to structure in the wind.


title:
Comparative study of tight-binding and ab initio electronic structure
  calculations focused on magnetic anisotropy in ordered CoPt alloy

abstract:
  An empirical multiorbital (spd) tight binding (TB) model including magnetism
and spin-orbit coupling is applied to calculations of magnetic anisotropy
energy (MAE) in CoPt L1_0 structure. A realistic Slater-Koster parametrisation
for single-element transition metals is adapted for the ordered binary alloy.
Spin magnetic moment and density of states are calculated using a
full-potential linearized augmented plane-wave (LAPW) ab initio method and our
TB code with different variants of the interatomic parameters. Detailed mutual
comparison of this data allows for determination of a subset of the compound TB
parameters tuning of which improves the agreement of the TB and LAPW results.
MAE calculated as a function of band filling using the refined parameters is in
broad agreement with ab initio data for all valence states and in quantitative
agreement with ab initio and experimental data for the natural band filling.
Our work provides a practical basis for further studies of relativistic
magnetotransport anisotropies by means of local Green's function formalism
which is directly compatible with our TB approach.


title: Existence of ground states for negative ions at the binding threshold

abstract:
  As the nuclear charge Z is continuously decreased an N-electron atom
undergoes a binding-unbinding transition at some critical Z_c. We investigate
whether the electrons remain bound when Z=Z_c and whether the radius of the
system stays finite as Z_c is approached. Existence of a ground state at Z_c is
shown under the condition Z_c<N-K, where K is the maximal number of electrons
that can be removed at Z_c without changing the ground state energy.

categories: math-ph math.AP math.MP math.SP physics.atom-ph


title: Dark Matter; Modification of f(R) or Wimps Miracle

abstract:
  The identity of dark matter is one of the key outstanding problems in both
particle and astrophysics. In this thesis, I review some candidates of dark
matter, especially WIMPs (weakly interacting massive particles) which is one of
the best candidate so it is called that WIMPs miracle. In addition of this,
there are also some theories of modification of gravity, by changing the law of
gravity, it could be possible that the dark matter observations are explained.
Until the dark matter particle is detected, there is some room for uncertainty.
So we should consider every part of the problem and solve it. Dark matter
problem is covering a large area so every possibility is important. So f(R)
gravity is also reviewed in this thesis and some theories are considered as a
possible solution of dark matter problem. Finally we highlight that, even in
the case of WIMPs or another particles solution, f(R) gravity is also can be
used for this problem. However, last words will be said by experiments.


title: Critical Heegaard surfaces obtained by self-amalgamation

abstract:
  Critical surfaces can be regarded as topological index 2 minimal surfaces
which was introduced by David Bachman. In this paper we give a sufficient
condition and a necessary condition for self-amalgamated Heegaard surfaces to
be critical.


title:
Spreading and vanishing in nonlinear diffusion problems with free
  boundaries

abstract:
  We study nonlinear diffusion problems of the form $u_t=u_{xx}+f(u)$ with free
boundaries. Such problems may be used to describe the spreading of a biological
or chemical species, with the free boundary representing the expanding front.
For special $f(u)$ of the Fisher-KPP type, the problem was investigated by Du
and Lin [8]. Here we consider much more general nonlinear terms. For any $f(u)$
which is $C^1$ and satisfies $f(0)=0$, we show that the omega limit set
$\omega(u)$ of every bounded positive solution is determined by a stationary
solution. For monostable, bistable and combustion types of nonlinearities, we
obtain a rather complete description of the long-time dynamical behavior of the
problem; moreover, by introducing a parameter $\sigma$ in the initial data, we
reveal a threshold value $\sigma^*$ such that spreading ($\lim_{t\to\infty}u=
1$) happens when $\sigma>\sigma^*$, vanishing ($\lim_{t\to\infty}u=0$) happens
when $\sigma<\sigma^*$, and at the threshold value $\sigma^*$, $\omega(u)$ is
different for the three different types of nonlinearities. When spreading
happens, we make use of "semi-waves" to determine the asymptotic spreading
speed of the front.


title:
Voltage and Energy-Delay Performance of Giant Spin Hall Effect Switching
  for Magnetic Memory and Logic

abstract:
  In this letter, we show that Giant Spin Hall Effect (GSHE) MRAM can enable
better energy- delay and voltage performance than traditional MTJ based spin
torque devices at scaled nanomagnet dimensions (10-30 nm). Firstly, we derive
the effect of dimensional scaling on spin injection efficiency, voltage-delay
and energy-delay of spin torque switching using MTJs and GSHE and identify the
optimum electrode geometry for low operating voltage (<0.1 V), high speed (>10
GHz) operation. We show that effective spin injection efficiency >100 % can be
obtained using optimum spin hall electrode thickness for 30 nm nanomagnet
widths. Finally, we derive the energy-delay trajectory of GSHE and MTJ devices
to calculate the energy-delay product of GSHE and MTJ devices with an energy
minimum at the characteristic time of the magnets. Optimized GSHE devices when
combined with PMA can enable MRAM with scaled nanomagnets (30 nm X 60 nm),
ultra-low voltage operation (< 0.1 V), fast switching times (10 ps) and
switching energy as low as 100 aJ/bit.


title: A Single Journal Study : Malaysian Journal of Computer Science

abstract:
  Single journal studies are reviewed and measures used in the studies are
highlighted. The following quantitative measures are used to study 272 articles
published in Malaysian Journal of Computer Science, (1) the article
productivity of the journal from 1985 to 2007, (2) the observed and expected
authorship productivity tested using Lotka's Law of author productivity,
identification and listing of core authors; (3) the authorship, co-authorship
pattern by authors' country of origin and institutional affiliations; (4) the
subject areas of research; (5) the citation analysis of resources referenced as
well as the age and half-life of citations; the journals referenced and tested
for zonal distribution using Bradford's law of journal scattering; the extent
of web citations; and (6) the citations received by articles published in MJCS
and impact factor of the journal based on information obtained from Google
Scholar, the level of author and journal self-citation.


title:
Robust Photon Entanglement via Quantum Interference in Optomechanical
  Interfaces

abstract:
  Entanglement is often the key element in quantum information protocols. Here,
we present schemes to generate robust photon entanglement in optomechanical
interfaces via quantum interference. The schemes explore the excitation of the
Bogoliubov dark mode and the destructive quantum interference between the
bright modes of the interface, similar to electromagnetically induced
transparency, to eliminate leading-order effects of the mechanical noise. Both
continuous-variable and discrete-state entanglements that are robust against
the mechanical noise can be achieved.


title:
Creation of Helical Dirac Fermions by Interfacing Two Gapped Systems of
  Ordinary Fermions

abstract:
  Topological insulators (TIs) are a unique class of materials characterized by
a surface (edge) Dirac cone state of helical Dirac fermions in the middle of
bulk (surface) gap. When the thickness (width) of TIs is reduced, however,
interaction between the surface (edge) states will open a gap removing the
Dirac cone. Using density function theory calculation, we demonstrate the
creation of helical Dirac fermions from interfacing two gapped TI films, a
single bilayer Bi grown on a single quintuple layer Bi2Se3 or Bi2Te3. The
theoretical prediction is directly confirmed by experiment. We further show
that the extrinsic helical Dirac fermions consists of predominantly Bi bilayer
states, which are created by a giant Rashba effect due to interfacial charge
transfer. Our findings provide a promising new method to create novel TI
materials by interface engineering.


title: Three dimensions of knot coloring

abstract:
  This survey article discusses three aspects of knot colorings. Fox colorings
are assignments of labels to arcs, Dehn colorings are assignments of labels to
regions, and Alexander-Briggs colorings assign labels to vertices. The labels
are found among the integers modulo n. The choice of n depends upon the knot.
Each type of coloring rules has an associated rule that must hold at each
crossing. For the Alexander Briggs colorings, the rules hold around regions.
The relationships among the colorings is explained.


title:
Auditing scholarly journals published in Malaysia and assessing their
  visibility

abstract:
  The problem with the identification of Malaysian scholarly journals lies in
the lack of a current and complete listing of journals published in Malaysia.
As a result, librarians are deprived of a tool that can be used for journal
selection and identification of gaps in their serials collection. This study
describes the audit carried out on scholarly journals, with the objectives (a)
to trace and characterized scholarly journal titles published in Malaysia, and
(b) to determine their visibility in international and national indexing
databases. A total of 464 titles were traced and their yearly trends, publisher
and publishing characteristics, bibliometrics and indexation in national,
international and subject-based indexes were described.


title:
Publication productivity and citation analysis of the Medical Journal of
  Malaysia: 2004 - 2008

abstract:
  We analysed 580 articles (original articles only) published in Medical
Journal of Malaysia between 2004 and 2008, the resources referenced by the
articles and the citations and impact received. Our aim was to examine article
and author productivity, the age of references used and impact of the journal.
Publication data was obtained from MyAIS database and Google Scholar provided
the citation data. From the 580 articles analyzed, contributors mainly come
from the hospitals, universities and clinics. Contributions from foreign
authors are low. The useful lives of references cited were between 3 to 11
years. ISI derived Impact factor for MJM ranged between 0.378 to 0.616. Journal
self-citation is low. Out of the 580 sampled articles, 76.8% have been cited at
least once over the 5 years and the ratio of total publications to citations is
1: 2.6.


title:
Exploring the needs of Malay manuscript studies community for an
  e-learning platform

abstract:
  Philology studies are often associated with traditional methods of teaching
and learning. This study explores the possibility of e-learning adoption
amongst Malay manuscripts learning community. The Soft System Methodology (SSM)
is used to guide the investigation. SSM emphasises on understanding the problem
situations faced by Malay manuscript learning community and expresses the
situations in rich pictures. The manuscript learning community comprises
lecturers, students and researchers in the field of philology. Data were
gathered from interviews, focus group discussions and observations. Academy of
Malay Studies, University of Malaya is the case study setting, focusing on
lecturers who teach and students who enrol in a philology course as well as
doctoral students researching on manuscript studies. The findings highlight
problems faced by the various stakeholders and propose solutions in the form of
a conceptual model for a collaborative electronic platform to improve teaching
and learning as well as utilizing digitized manuscript surrogates held in a
digital library of Malay manuscripts.


title: Nonlinear electrohydrodynamics of a viscous droplet

abstract:
  A classic result due to G.I.Taylor is that a drop placed in a uniform
electric field becomes a prolate or oblate spheroid, which is axisymmetrically
aligned with the applied field. We report an instability and symmetry-breaking
transition to obliquely oriented, steady and unsteady shapes in strong fields.
Our experiments reveal novel droplet behaviors such as tumbling, shape
oscillations, and chaotic dynamics even under creeping flow conditions. A
theoretical model, which includes anisotropy in the polarization relaxation due
to drop asphericity and charge convection due to drop fluidity, elucidates the
interplay of interfacial flow and charging as the source of the rich nonlinear
dynamics.


title: Measuring the influence of a journal using impact and diffusion factors

abstract:
  Presents the result of the calculated IS! equivalent Impact Factor, Relative
Diffusion Factor (RDF), and Journal Diffusion Factor (JDF) for articles
published in the Medical Journal of Malaysia (MJM) between the years 2004 and
2008 in both their synchronous and diachronous versions. The publication data
are collected from MyAis (Malaysian Abstracting & Indexing system) while the
citation data are collected from Google Scholar. The values of the synchronous
JDF ranges from 0.057 - 0.14 while the diachronous JDF ranges from 0.46 - 1.98.
The high diachronous JDF is explained by a relatively high number of different
citing journals against the number of publications. This implies that the
results of diachronous JDF is influenced by the numbers of publications and a
good comparison may be one of which the subject of analysis have similar number
of publications and citations period. The yearly values of the synchronous RDF
vary in the range of 0.66 - 1.00 while diachronous RDF ranges from 0.62 - 0.88.
The result shows that diachronous RDF is negatively correlated with the number
of citations, resulting in a low RDF value for highly cited publication years.
What this implies in practice is that the diffusion factors can be calculated
for every additional year at any journal level of analysis. This study
demonstrates that these indicators are valuable tools that help to show
development of journals as it changes through time.


title: International Contribution to Nipah Virus Research 1999-2010

abstract:
  This study examines 462 papers on Nipah virus research published from 1999 to
2010, identifying the active authors, institutions and citations received. Data
was extracted from SCI-Expanded database, (Web of Science) and analyzed using
descriptive figures and tables. The results show the growth of publication is
incremental up to 2010 even though the average citations received is
decreasing. The ratio of authors to articles is 1330: 426. The active
contributing countries are USA (41.0%), Australia (19.3%), Malaysia (16.0%),
England (6.5%) and France (5.6%). The productive authors are mainly affiliated
to the Centre for Disease Control and Prevention, USA and Commonwealth
Scientific and Industrial Research Organization (CSIRO) in Australia and
University of Malaya Medical Centre, Malaysia. A total of 10572 citations were
received and the ratio of articles to citation is 1: 24.8. Collaboration with
the bigger laboratories in USA and Australia is contributive to the sustained
growth of published literature and to access diverse expertise.


title:
Collection security management at university libraries: assessment of
  its implementation status

abstract:
  This study examines the literature on library security and collection
security to identify factors to be considered to develop a collection security
management assessment instrument for university libraries. A "house" model was
proposed consisting of five factors; collection security governance, operations
and processes, people issues, physical and technical issues and the security
culture in libraries. An assessment instrument listing items covering the five
factors was pilot tested on 61 samples comprising chief librarians, deputy
librarians, departmental, sectional heads and professional staff working in
four university libraries in Nigeria. The level of security implementation is
assessed on a scale of 1=not-implemented, 2=planning stage, 3=partial
implementation, 4=close to completion, and 5=full implementation. The
instrument was also tested for reliability. Reliability tests indicate that all
five factors are reliable with Cronbach's alpha values between 0.7 and 0.9,
indicating that the instrument can be used for wider distribution to explore
and assess the level of collection security implementation in university
libraries from a holistic perspective.


title:
Information systems security in special and public libraries: an
  assessment of status

abstract:
  Explores the use of an assessment instrument based on a model named library
information systems security assessment model (LISSAM) to assess the 155 status
in special and public libraries in Malaysia. The study aims to determine the
implementation status of technological and organizational components of the
LISSAM model. An implementation index as well as a scoring tool is presented to
assess the IS safeguarding measures in a library. Data used was based on
questionnaires distributed to a total of 50 individuals who are responsible for
the information systems (IS) or IT in the special and public libraries in
Malaysia. Findings revealed that over 95% of libraries have high level of
technological implementation but 54% were fair poorly on organizational
measures, especially on lack of security procedures, administrative tools and
awareness creation activities.


title:
Open Access repositories and journals for visibility: Implications for
  Malaysian libraries

abstract:
  This paper describes the growth of Open Access (OA) repositories and journals
as reported by monitoring initiatives such as ROAR (Registry of Open Access
Repositories), Open DOAR (Open Directory of Open Access Repositories), DOAJ
(Directory of Open Access Journals), Directory of Web Ranking of World
Repositories by the Cybermetrics Laboratory in Spain and published literature.
The performance of Malaysian OA repositories and journals is highlighted. The
strength of OA channels in increasing visibility and citations are evidenced by
research findings. It is proposed that libraries champion OA initiatives by
making university or institutional governance aware; encouraging institutional
journal publishers to adopt OA platform; collaborating with research groups to
jumpstart OA institutional initiatives and to embed OA awareness into user and
researcher education programmes. By actively involved, libraries will be free
of permission, licensing and archiving barriers usually imposed in traditional
publishing situation.


title:
Boundedness for Second Order Differential Equations with Jumping
  p-Laplacian and an Oscillating Term

abstract:
  In this paper, we are concerned with the boundedness of all the solutions for
a kind of second order differential equations with p-Laplacian and an
oscillating term $(\phi_p(x'))'+a\phi_p(x^+)-b\phi_p(x^-)=G_x(x,t)+f(t)$,
where$x^+=\max (x,0)$,$x^- =\max(-x,0)$,$\phi_p(s)=|s|^{p-2}s$,$p\geq2$, $a $
and $b$ are positive constants $(a\not=b)$, the perturbation $f(t)\in {\cal
C}^{23}(\RR/2\pi_p \ZZ)$, the oscillating term $G\in {\cal
C}^{21}(\RR\times\RR/2\pi_p \ZZ)$,where
$\pi_p=\frac{2\pi(p-1)^{\frac{1}{p}}}{p\sin\frac{\pi}{p}},$ and $G(x,t)$
satisfies $\label{G} |D_x^iD_t^jG(x,t)|\le C,\quad 0\le i+j\le 21,$ and
$\label{hatG} |D_t^j\hat{G}|\le C,\quad 0\le j\le 21$ for some $C>0$, where
$\hat{G}$ is some function satisfying $\frac{\pa \hat{G}}{\pa x}=G$.


title:
Stability of analytical and numerical solutions of nonlinear stochastic
  delay differential equations

abstract:
  This paper concerns the stability of analytical and numerical solutions of
nonlinear stochastic delay differential equations (SDDEs). We derive sufficient
conditions for the stability, contractivity and asymptotic contractivity in
mean square of the solutions for nonlinear SDDEs. The results provide a unified
theoretical treatment for SDDEs with constant delay and variable delay
(including bounded and unbounded variable delays). Then the stability,
contractivity and asymptotic contractivity in mean square are investigated for
the backward Euler method. It is shown that the backward Euler method preserves
the properties of the underlying SDDEs. The main results obtained in this work
are different from those of Razumikhin-type theorems. Indeed, our results hold
without the necessity of constructing of finding an appropriate Lyapunov
functional.


title:
Semiparametric Bayesian Density Estimation with Disparate Data Sources:
  A Meta-Analysis of Global Childhood Undernutrition

abstract:
  Undernutrition, resulting in restricted growth, and quantified here using
height-for-age z-scores, is an important contributor to childhood morbidity and
mortality. Since all levels of mild, moderate and severe undernutrition are of
clinical and public health importance, it is of interest to estimate the shape
of the z-scores' distributions.
  We present a finite normal mixture model that uses data on 4.3 million
children to make annual country-specific estimates of these distributions for
under-5-year-old children in the world's 141 low- and middle-income countries
between 1985 and 2011. We incorporate both individual-level data when
available, as well as aggregated summary statistics from studies whose
individual-level data could not be obtained. We place a hierarchical Bayesian
probit stick-breaking model on the mixture weights. The model allows for
nonlinear changes in time, and it borrows strength in time, in covariates, and
within and across regional country clusters to make estimates where data are
uncertain, sparse, or missing.
  This work addresses three important problems that often arise in the fields
of public health surveillance and global health monitoring. First, data are
always incomplete. Second, different data sources commonly use different
reporting metrics. Last, distributions, and especially their tails, are often
of substantive interest.


title:
The Equipartition Magnetic Field Formula in Starburst Galaxies:
  Accounting for Pionic Secondaries and Strong Energy Losses

abstract:
  Equipartition arguments provide an easy way to find a characteristic scale
for the magnetic field from radio emission, by assuming the energy densities in
cosmic rays and magnetic fields are the same. Yet most of the cosmic ray
content in star-forming galaxies is in protons, which are invisible in radio
emission. Therefore, the argument needs assumptions about the proton spectrum,
typically that of a constant proton/electron ratio. In some environments,
particularly starburst galaxies, the reasoning behind these assumptions does
not necessarily hold: secondary pionic positrons and electrons may be
responsible for most of the radio emission, and strong energy losses can alter
the proton/electron ratio. We derive an equipartition expression that should
work in a hadronic loss-dominated environment like starburst galaxies.
Surprisingly, despite the radically different assumptions from the classical
equipartition formula, numerically the results for starburst magnetic fields
are similar. We explain this fortuitous coincidence using the energetics of
secondary production and energy loss times. We show that these processes cause
the proton/electron ratio to be ~100 for GHz-emitting electrons in starbursts.


title:
Internationalization of Malaysian Mathematical and Computer Science
  Journal

abstract:
  The internationalization characteristics of two Malaysian journals, Bulletin
of the Malaysian Mathematical Sciences Society (indexed by ISI) and the
Malaysian Journal of Computer Science (indexed by Inspec and Scopus) is
observed. All issues for the years 2000 to 2007 were looked at to obtain the
following information, (i) total articles published between 2000 and 2007; (ii)
the distribution of foreign and Malaysian authors publishing in the journals;
(iii) the distribution of articles by country and (iv) the geographical
distribution of authors citing articles published in the journals. Citation to
articles is derived from information given by Google scholar. The results
indicate that both journals exhibit average internationalization
characteristics as they are current in their publications but with between 19%
-30% international composition of reviewers or editorials, publish between
36%-79% of foreign articles and receive between 60%-70% of citations from
foreign authors.


title: Stochastic Nonlinear Electrical Characteristics of Graphene

abstract:
  A stochastic nonlinear electrical characteristic of graphene is reported.
Abrupt current changes are observed from voltage sweeps between the source and
drain with an on/off ratio up to 10^(3). It is found that graphene channel
experience the topological change. Active radicals in an uneven graphene
channel cause local changes of electrostatic potential. Simulation results
based on the self-trapped electron and hole mechanism account well for the
experimental data. Our findings illustrate an important issue of reliable
electron transports and help for the understanding of transport properties in
graphene devices.


title: Quantum discord in spin systems with dipole-dipole interaction

abstract:
  The behavior of total purely quantum correlation (discord) in dimers
consisting of dipolar-coupled spins 1/2 is studied. We found that the discord
Q=0 at the absolute zero temperature. With increasing the temperature $T$, at
first the quantum correlations in the system increase, smoothly reach the
maximum, and then turn again into zero according to the asymptotic law
$T^{-2}$. It is also shown that in absence of external magnetic field $B$, the
classical correlation $C$ at $T\to0$ is, vice versa, maximal. Our calculations
predict that in crystalline gypsum ${\rm CaSO_4\cdot2H_2O}$ the value of
natural (B=0) quantum discord between nuclear spins of hydrogen atoms is
maximal at the temperature of 0.644 $\mu$K, and for 1,2-dichloroethane ${\rm
H_2ClC-CH_2Cl}$ the discord achieves the largest value at $T=0.517 \mu$K. In
both cases, the discord equals $Q\approx0.083$ bit/dimer what is 8.3% of its
upper limit in two-qubit systems. We estimate also that for gypsum at room
temperature $Q\sim10^{-18}$ bit/dimer, and for 1,2-dichloroethane at T=90 K the
discord is $Q\sim10^{-17}$ bit per a dimer.


title:
Characterization of magnetostatic surface spin waves in magnetic thin
  films: evaluation for microelectronic applications

abstract:
  The authors have investigated the possibility of utilizing spin waves for
inter- and intra-chip communications, and as logic elements using both
simulations and experimental techniques. Through simulations it has been shown
that the decay lengths of magnetostatic spin waves are affected most by the
damping parameter, and least by the exchange stiffness constant. The damping
and dispersion properties of spin waves limit the attenuation length to several
tens of microns. Thus, we have ruled out the possibility of inter-chip
communications via spin waves. Experimental techniques for the extraction of
the dispersion relationship have also been demonstrated, along with
experimental demonstrations of spin wave interference for amplitude modulation.
The effectiveness of spin wave modulation through interference, along with the
capability of determining the spin wave dispersion relationships electrically
during manufacturing and testing phase of chip production may pave the way for
using spin waves in analog computing wherein the circuitry required for
performing similar functionality becomes prohibitive.


title:
Electric-field-induced magnetization changes in Co/Al2O3 granular
  multilayers

abstract:
  We study experimentally the effect of electric field on the magnetization of
Co/Al2O3 granular multilayers. We observe two distinct regimes: (a) low-field
regime when the net magnetization of the system changes in a reversible way
with the applied electric field and (b) high-field regime when the
magnetization decreases irreversibly. The former is attributed to the changes
in the relative 3d-orbital occupation of the minority and majority bands in the
Co granules. A theoretical model has been developed to explain the electric
field induced changes in the band structure of the granular system and hence
the magnetic moment. The latter result may be understood assuming the electric
field induces oxygen migration from Al2O3 to the Co granules, since an increase
in oxidation state of the Co granules is shown, through ab-initio calculations,
to give rise to a reduced magnetization of the system.


title: Nucleon mass and strange content from (2+1)-flavor Domain Wall Fermion

abstract:
  We report on our ongoing study of nucleon properties, the nucleon mass and
the strange quark content (<N|ss|N>) in particular. These calculations are done
on (2+1)-flavor Domain Wall Fermion (DWF) ensembles with Iwasaki gauge action
with 2 different lattice spacings (a ~ 0.08, 0.11fm) and DWF with Dislocation
Suppressing Determinant Ratio(DSDR) (a ~ 0.14fm), generated by RBC/UKQCD
collaborations.


title:
Collaborative digital library of historical resources: Evaluation of
  first users

abstract:
  This paper describes the digital library of historical resources, a research
project which involves building a testbed for the purpose of developing and
testing new collaborative digital library functionality and presents an initial
analysis of the digital library's public use on the web. The digital library is
modeled to focus on serving secondary students information needs in conducting
history projects. As such, in the implementation of the digital library, the
use of online resources would be an integral part of history project based
learning activities. Students should be enabled to access digital resources,
create and publish their own documents in the digital library and share them
with others. As a testbed system, the collaborative digital library known as
CoreDev has demonstrated its capabilities in serving an educational community
as has been reflected by the positive feedback on the functional requirements
from 44 users. Over 75% of the respondents in the user survey considered
themselves capable of using the digital library easily. The beta tester
demographics (n = 105) indicate that the digital library is reaching its target
communities.


title:
Incorporating Betweenness Centrality in Compressive Sensing for
  Congestion Detection

abstract:
  This paper presents a new Compressive Sensing (CS) scheme for detecting
network congested links. We focus on decreasing the required number of
measurements to detect all congested links in the context of network
tomography. We have expanded the LASSO objective function by adding a new term
corresponding to the prior knowledge based on the relationship between the
congested links and the corresponding link Betweenness Centrality (BC). The
accuracy of the proposed model is verified by simulations on two real datasets.
The results demonstrate that our model outperformed the state-of-the-art CS
based method with significant improvements in terms of F-Score.


title:
The Pattern of E-Book Use amongst Undergraduates an Malaysia: A Case of
  to Know is to Use

abstract:
  This exploratory study focuses on identifying the usage pattern of e-books
especially on how, when, where and why undergraduates at the Faculty of
Computer Science and Information Technology (FCSIT), University of Malaya (UM),
Kuala Lumpur use or do not use the e-books service provided by the University
of Malaya library. A total of 206 (82%) useable questionnaires form the basis
of analysis. The results indicate even though the students are heavy users of
the Internet, rate themselves as skilled in Internet use and have positive
attitude towards the e-book service, the level of e-book use is still low
(39%). The students become aware of the e-book service mainly while visiting
the University of Malaya Library Website, or are referred to it by their
lecturers, friends or the librarians. About 70% rate positively on the e-book
service. Those who are users of e-books find e-books easy to use and their
usages are mainly for writing assignment or project work. Most respondents
prefer to use e-versions of textbooks and reference sources. Generally, both
users and non-users of e-books prefer to use the printed version of textbooks
especially if the text is continuously used. There are significant difference
between the frequency of e-book use and gender; between past usage of e-book
and preference for electronic textbooks and reference books. The possible
factors which may be related to e-book use are categorized into 4 groups and
presented in a model, which comprises the ICT competencies of the students,
their cognitive makeup, the degree of user access to the e-books and the
functional or use factors.


title:
Weingarten calculus for matrix ensembles associated with compact
  symmetric spaces

abstract:
  A method for computing integrals of polynomial functions on compact symmetric
spaces is given. Those integrals are expressed as sums of functions on
symmetric groups.


title: Energy exchange in Weyl geometry

abstract:
  We study homogeneous and isotropic cosmologies in a Weyl spacetime. We show
that the field equations can be reduced to the Einstein equations with a
two-fluid source and analyze the qualitative, asymptotic behavior of the
models. Assuming an interaction of the two fluids we impose conditions so that
the solutions of the corresponding dynamical system remain in the physically
acceptable phase space. We show that in Weyl integrable spacetime, the
corresponding scalar field acts as a phantom field and therefore, it may give
rise to a late accelerated expansion of the Universe.


title: Unconventional states of bosons with synthetic spin-orbit coupling

abstract:
  Spin-orbit coupling with bosons gives rise to novel properties that are
absent in usual bosonic systems. Under very general conditions, the
conventional ground state wavefunctions of bosons are constrained by the
"no-node" theorem to be positive-definite. In contrast, the linear-dependence
of spin-orbit coupling leads to complex-valued condensate wavefunctions beyond
this theorem. In this article, we review the study of this class of
unconventional Bose-Einstein condensations focusing on their topological
properties. Both the 2D Rashba and 3D $\vec{\sigma} \cdot \vec{p}$-type Weyl
spin-orbit couplings give rise to Landau-level-like quantization of
single-particle levels in the harmonic trap. The interacting condensates
develop the half-quantum vortex structure spontaneously breaking time-reversal
symmetry and exhibit topological spin textures of the skyrmion type. In
particular, the 3D Weyl coupling generates topological defects in the
quaternionic phase space as an SU(2) generalization of the usual U(1) vortices.
Rotating spin-orbit coupled condensates exhibit rich vortex structures due to
the interplay between vorticity and spin texture. In the Mott-insulating states
in optical lattices, quantum magnetism is characterized by the
Dzyaloshinskii-Moriya type exchange interactions.


title: Inferring the nature of the boson at 125-126 GeV

abstract:
  The presence of a bosonic resonance near 125 GeV has been firmly established
at the Large Hadron Collider. Understanding the exact nature of this boson is a
priority. The task now is to verify whether the boson is indeed the scalar
Higgs as proposed in the Standard Model of particle physics, or something more
esoteric as proposed in the plethora of extensions to the Standard Model. This
requires a verification that the boson is a $J^{PC}=0^{++}$ state with
couplings precisely as predicted by the Standard Model. Since a non Standard
Model boson can in some cases mimic the Standard Model Higgs in its couplings
to gauge bosons, it is essential to rule out any anomalous behavior in its
gauge couplings. We present a step by step methodology to determine the
properties of this resonance without making any assumptions about its
couplings. We present the analysis in terms of uni-angular distributions which
lead to angular asymmetries that allow for the extraction of the couplings of
the 125-126 GeV resonance to Z bosons. We show analytically and numerically,
that these asymmetries can unambiguously confirm whether the new boson is
indeed the Standard Model Higgs boson.


title:
Observation of spontaneous quantum fluctuations in photon absorption by
  atoms

abstract:
  Fluctuations in light absorption by atoms are observed by applying laser
light on rubidium atoms and measuring the transmitted light intensity
fluctuations. These fluctuations are spontaneous noise, which are generic to
photon atom interactions. By making use of the sub-shot noise random signal
detection technology, we have measured the spectra at sub-shot noise levels to
reveal their rich nature, which had previously been unobserved. The effects of
atoms transiting the laser beam, Rabi flopping in the optical transitions and
Larmor precession of the magnetic moment are observed in the spectra. The
properties of the fluctuations reflect not only the quantum behavior of atoms,
but also that of light.


title:
Assemblathon 2: evaluating de novo methods of genome assembly in three
  vertebrate species

abstract:
  Background - The process of generating raw genome sequence data continues to
become cheaper, faster, and more accurate. However, assembly of such data into
high-quality, finished genome sequences remains challenging. Many genome
assembly tools are available, but they differ greatly in terms of their
performance (speed, scalability, hardware requirements, acceptance of newer
read technologies) and in their final output (composition of assembled
sequence). More importantly, it remains largely unclear how to best assess the
quality of assembled genome sequences. The Assemblathon competitions are
intended to assess current state-of-the-art methods in genome assembly. Results
- In Assemblathon 2, we provided a variety of sequence data to be assembled for
three vertebrate species (a bird, a fish, and snake). This resulted in a total
of 43 submitted assemblies from 21 participating teams. We evaluated these
assemblies using a combination of optical map data, Fosmid sequences, and
several statistical methods. From over 100 different metrics, we chose ten key
measures by which to assess the overall quality of the assemblies. Conclusions
- Many current genome assemblers produced useful assemblies, containing a
significant representation of their genes, regulatory sequences, and overall
genome structure. However, the high degree of variability between the entries
suggests that there is still much room for improvement in the field of genome
assembly and that approaches which work well in assembling the genome of one
species may not necessarily work well for another.


title:
The catalogue of positions of optically bright extragalactic radio
  sources OBRS-2

abstract:
  It is anticipated that future space-born missions, such as Gaia, will be able
to determine in optical domain positions of more than 100,000 bright quasars
with sub-mas accuracies that are comparable to very long baseline
interferometry (VLBI) accuracies. Comparisons of coordinate systems from
space-born missions and from VLBI will be very important, first for
investigation of possible systematic errors, second for investigation of
possible shift between centroids of radio and optical emissions in active
galaxy nuclea. In order to make such a comparison more robust, a program of
densification of the grid of radio sources detectable with both VLBI and Gaia
was launched in 2006. In the second observing campaign a set of 290 objects
from the list of 398 compact extragalactic radio sources with declinations
greater -10 deg was observed with the VLBA+EVN in 2010-2011 with the primary
goal of producing their images with milliarcsecond resolution. These sources
are brighter than 18 magnitude at V band. In this paper coordinates of observed
sources have been derived with milliarcsecond accuracies from analysis of these
VLBI observations following the method of absolute astrometry and their images
were produced. The catalogue of positions of 295 target sources and estimates
of their correlated flux densities at 2.2 and 8.4 GHz is presented. The
accuracies of source coordinates are in a range of 2 to 200 mas, with the
median 3.2 mas.


title: Theoretical study of lithium clusters by electronic stress tensor

abstract:
  We study the electronic structure of small lithium clusters Li_n (n=2-8)
using the electronic stress tensor. We find that the three eigenvalues of the
electronic stress tensor of the Li clusters are negative and degenerate, just
like the stress tensor of liquid. This leads us to propose that we may
characterize a metallic bond in terms of the electronic stress tensor. Our
proposal is that in addition to the negativity of the three eigenvalues of the
electronic stress tensor, their degeneracy characterizes some aspects of the
metallic nature of chemical bonding. To quantify the degree of degeneracy, we
use the differential eigenvalues of the electronic stress tensor. By comparing
the Li clusters and hydrocarbon molecules, we show that the sign of the largest
eigenvalue and the differential eigenvalues could be useful indices to evaluate
the metallicity or covalency of a chemical bond.


title:
Algebraic Unsolvability of Problem of Absolute Stability of
  Desynchronized Systems Revisited

abstract:
  In the author's article "Algebraic unsolvability of problem of absolute
stability of desynchronized systems" (Automat. Remote Control 51 (1990), no. 6,
pp. 754--759), it was shown that in general for linear desynchronized systems
there are no algebraic criteria of absolute stability. In this paper, a few
misprints occurred in the original version of the article are corrected, and
two figures are added.


title: Cancellativization of dimer models

abstract:
  We show that any dimer model can be made cancellative without changing the
characteristic polygon.


title: Hopping thermoelectric transport in finite systems: boundary effects

abstract:
  It is shown that for the hopping regime, the thermopowers in both finite
two-terminal and three-terminal systems are governed by the edges of the
samples. This is due to the fact that the energy transfer between a transport
electron and a conducting terminal is determined by the site most strongly
coupled to that terminal. One-dimensional systems with both nearest-neighbor
and variable-range transport as well as certain types of two-dimensional
systems, are considered. For a given sample, the changes in the thermopowers
due to modifying the bulk are quite limited, compared with those of the
conductance. When the small thermopower changes exist, their average over a
large ensemble of mesoscopic samples will vanish. We also obtain the
distribution of the thermopower in such an ensemble and show that its width
approaches a finite limit with increasing sample length. This contrasts with
the distribution of conductances in such systems, whose width vanishes in the
long sample limit. Finally, we find that the thermal conductances in the
three-terminal case have a boundary-dominated contribution, due to
non-percolating conduction paths. This contribution can become dominant when
the usual conductance is small enough. All our theoretical statements are
backed by numerical computations.


title: A2ILU: Auto-accelerated ILU Preconditioner for Sparse Linear Systems

abstract:
  The ILU-based preconditioning methods in previous work have their own
parameters to improve their performances. Although the parameters may degrade
the performance, their determination is left to users. Thus, these previous
methods are not reliable in practical computer-aided engineering use. This
paper proposes a novel ILU-based preconditioner called the auto-accelerated
ILU, or A2ILU. In order to improve the convergence, A2ILU introduces
acceleration parameters which modify the ILU factorized preconditioning matrix.
A$^2$ILU needs no more operations than the original ILU because the
acceleration parameters are optimized automatically by A2ILU itself. Numerical
tests reveal the performance of A2ILU is superior to previous ILU-based methods
with manually optimized parameters. The numerical tests also demonstrate the
ability to apply auto-acceleration to ILU-based methods to improve their
performances and robustness of parameter sensitivities.


title:
Chaos : Butterflies also generate phase transitions and parallel
  universes

abstract:
  We exhibit examples of mixing subshifts of finite type and potentials such
that there are phase transitions but the pressure is always strictly convex.
More surprisingly, we show that the pressure can be analytic on some interval
although there exist several equilibrium states.


title: Complexity Estimates for Two Uncoupling Algorithms

abstract:
  Uncoupling algorithms transform a linear differential system of first order
into one or several scalar differential equations. We examine two approaches to
uncoupling: the cyclic-vector method (CVM) and the
Danilevski-Barkatou-Z\"urcher algorithm (DBZ). We give tight size bounds on the
scalar equations produced by CVM, and design a fast variant of CVM whose
complexity is quasi-optimal with respect to the output size. We exhibit a
strong structural link between CVM and DBZ enabling to show that, in the
generic case, DBZ has polynomial complexity and that it produces a single
equation, strongly related to the output of CVM. We prove that algorithm CVM is
faster than DBZ by almost two orders of magnitude, and provide experimental
results that validate the theoretical complexity analyses.


title: State labelling Wannier-Stark atomic interferometers

abstract:
  Using cold 87Rb atoms trapped in a 1D-optical lattice, atomic interferometers
involving coherent superpositions between different Wannier-Stark atomic states
are realized. Two di fferent kinds of trapped interferometer schemes are
presented: a Ramsey-type interferometer sensitive both to clock frequency and
external forces, and a symmetric accordion-type interferometer, sensitive to
external forces only. We evaluate the limits in terms of sensitivity and
accuracy of those schemes and discuss their application as force sensors. As a
first step, we apply these interferometers to the measurement of the Bloch
frequency and the demonstration of a compact gravimeter.


title: Spintronics and spincaloritronics in topological insulators

abstract:
  We study spintronics and spincaloritronics in topological insulators. We show
spintronics effects in 2D topological insulator junctions and 3D topological
insulators coupled to ferromagnets. We also investigate spin polarization on
the surface of a topological insulator induced by a circularly polarized light
and refraction at the junction between two topological insulators. As for
spincaloritronics effects, we show transverse magnetic heat transport and
thermoelectric transport in topological insulators. Finite-size effect in
topological insulators and band structure engineering of interface states of
topological insulators are also discussed.


title:
Intracavity trace molecular detection with a broadband mid-IR frequency
  comb source

abstract:
  Ultrasensitive detection of methane, isotopic carbon dioxide, carbon
monoxide, formaldehyde, acetylene and ethylene is performed in the spectral
range 2.5 - 5 \mu m using intracavity spectroscopy in broadband optical
parametric oscillators (OPOs). The OPOs were operated near degeneracy and
synchronously pumped either by a mode-locked erbium (1560 nm) or thulium (2050
nm) fiber laser. A large instantaneous bandwidth of up to 800 cm$^{-1}$ allows
for simultaneous detection of several gases. We observe an effective path
length enhancement due to coherent interaction inside the OPO cavity and
achieve part-per-billion sensitivity levels. The measured spectral shapes are
in good agreement with a model that takes into account group delay dispersion
across the broad OPO frequency band.


title:
Extremely low-frequency electromagnetic fields cause DNA strand breaks
  in normal Vero cells

abstract:
  Extremely low frequency electromagnetic fields aren't considered as a real
carcinogenic agent despite the fact that some studies have showed impairment of
the DNA integrity in different cells lines. The aim of this study was
evaluation of the late effects of a 100 Hz and 5.6 mT electromagnetic field,
applied continuously or discontinuously, on the DNA integrity of Vero cells
assessed by alkaline Comet assay and by cell cycle analysis. Normal Vero cells
were exposed to extremely low frequency electromagnetic fields (100 Hz, 5.6 mT)
for 45 minutes. The Comet assay and cell cycle analysis were performed 48 hours
after the treatment. Exposed samples presented an increase of the number of
cells with high damaged DNA as compared with non-exposed cells. Quantitative
evaluation of the comet assay showed a significantly ($<$0.001) increase of the
tail lengths, of the quantity of DNA in tail and of Olive tail moments,
respectively. The analysis of the registered comet indices showed that an
extremely low frequency electromagnetic field of 100 Hz and 5.6 mT had a
genotoxic impact on Vero cells. Cell cycle analysis showed an increase of the
frequency of the cells in S phase, proving the occurrence of single strand
breaks. The most probable mechanism of induction of the registered effects is
the production of different types of reactive oxygen species.


title: Quantum view on contextual logic of composite intelligent devices

abstract:
  Based on the ideas of quantum theory of open systems (QTOS) we propose the
consistent approach to study probabilistic many-valued propositional logic of
intelligent devices that are composed from separate but interconnected logical
units. In this preliminary communication we consider only the simplest example
of such systems, namely, four- valued probabilistic logical device composed of
two logical subsystems. We demonstrate that similar devices can generate two
classes of probabilistic propositions:1) decomposable propositions, which in
fact are equivalent to certain ordered pair of propositions in device
subsystems and 2) indecomposable propositions which are connected with inherent
logical interaction between device units. The indecomposable propositions are
undoubtedly of greatest interest since they, as shown in the paper, provide
powerful additional logical resource compared to standard parallel processing
in composite intelligent systems. The contextual logic of composite devices
proposed in this paper, as we believe, can be also used for analysis of highly
organized systems in cognitive sciences specifically in neuropsychology and
linguistics.


title:
A Non-Perturbative Construction of the Fermionic Projector on Globally
  Hyperbolic Manifolds I - Space-Times of Finite Lifetime

abstract:
  We give a functional analytic construction of the fermionic projector on a
globally hyperbolic Lorentzian manifold of finite lifetime. The integral kernel
of the fermionic projector is represented by a two-point distribution on the
manifold. By introducing an ultraviolet regularization, we get to the framework
of causal fermion systems. The connection to the "negative-energy solutions" of
the Dirac equation and to the WKB approximation is explained and quantified by
a detailed analysis of closed Friedmann-Robertson-Walker universes.


title: Formality of certain CW complexes

abstract:
  Let $X$ be a simply connected path connected topological space which is
formal in the sense of rational homotopy theory. Let
$Y=X\cup_\alpha\mathbb{D}^{n}$ where $\alpha:\mathbb{S}^{n-1}\to X$ is a
non-torsion element. Then we obtain a condition on $\alpha$ for the formality
of $Y$. We give several illustrative examples concerning the formality of a
finite CW complex having only even dimensional cells. This is the corrected
version of the earlier version which contained a serious error in Theorem 1.4.
This theorem, which now Theorem 1.1 of this version, has now been corrected.
The proofs of Theorems 1.1, 1.2, and 1.3 of the first version are not valid as
they used the erroneous result. In fact, we provide here a counterexample to
the assertion of Theorem 1.1. (See Example 3.1 below.) We do not know if the
statement of Theorem 1.2, which asserted the formality of Schubert varieties in
a generalized flag variety $G/B$, is valid. Theorem 1.3 is correct as stated as
it had been proved previously by Panov and Ray using entirely different
techniques.


title: Functional inequalities for the Bickley function

abstract:
  In this paper our aim is to deduce some complete monotonicity properties and
functional inequalities for the Bickley function. The key tools in our proofs
are the classical integral inequalities, like Chebyshev, H\"older-Rogers,
Cauchy-Schwarz, Carlson and Gr\"uss inequalities, as well as the monotone form
of l'Hospital's rule. Moreover, we prove the complete monotonicity of a
determinant function of which entries involve the Bickley function.


title: Functional inequalities for modified Struve functions

abstract:
  In this paper, by using a general result on the monotonicity of quotients of
power series, our aim is to prove some monotonicity and convexity results for
the modified Struve functions. Moreover, as consequences of the above mentioned
results, we present some functional inequalities as well as lower and upper
bounds for modified Struve functions. Our main results complement and improve
the results of Joshi and Nalwaya [11].


title: A generalization of Taub-NUT deformations

abstract:
  We introduce a generalization of Taub-NUT deformations for large families of
hyper-Kaehler quotients including toric hyper-Kaehler manifolds and quiver
varieties, and apply them to the case of the Hilbert schemes of k points on
C^2.


title: DVA for Assets

abstract:
  The effect of self-default on the valuation of liabilities and derivatives
(DVA) has been widely discussed but the effect on assets has not received
similar attention. Any asset whose value depends on the status, or existence,
of the firm will have a DVA. We extend (Burgard and Kjaer 2011) to provide a
hedging strategy for such assets and provide an in-depth example from the
balance sheet (Goodwill). We calibrate our model to seven US banks over the
crisis period of mid-2007 to 2011. This suggests that their reported profits
would have changed significantly if DVA on assets, as well as liabilities, was
included - unless the DVA was hedged.


title: Populations of Young Stellar Objects in Nearby Molecular Clouds

abstract:
  We develop a new method to identify YSOs from star-forming regions using the
photometry data from Spitzer's c2d Legacy Project. The aim is to obtain YSO
lists as complete as possible for studying the statistical properties, such as
Star Formation Rate (SFR) and lifetimes of YSOs in different evolutionary
stages. The largest obstacle for identifying YSOs comes from background
galaxies with similar SEDs to YSOs. Traditionally, selected color-color and
color-magnitude criteria are used to separate YSOs and galaxies. However, since
there is no obvious boundary between YSOs and galaxies in Color-Color Diagrams
(CCDs) and Color-Magnitude Diagrams (CMDs), those criteria may exclude faint
YSOs near the boundary. In this paper, we separate the YSOs and galaxies in
multi-dimensional (Multi-D) magnitude space, which is equivalent to using all
variations of CMDs simultaneously. Comparing sources from molecular clouds to
Spitzer's SWIRE data, which have negligible amount of YSOs, we can naturally
identify YSO candidates locating outside of the galaxy populated regions in the
Multi-D space. In the five c2d-surveyed clouds, we select 322 new YSO
candidates (YSOc), miss/exclude 33 YSOc compared to Evans et al. 2009 and
result in 1313 YSOc in total. As a result, SFR increases 28% correspondingly,
but the lifetimes of YSOs in different evolutionary stages remain unchanged.
Comparing to theories Krumholz & McKee 2005, our derived SFR suggests that star
formation in large scale is dominated by supersonic turbulence rather than
magnetic fields. Furthermore, we identify 7 new Very Low Luminosity Objects.


title:
Mie scattering analog in graphene: lensing, particle confinement, and
  depletion of Klein tunneling

abstract:
  Guided by the analogy to Mie scattering of light on small particles we show
that the propagation of a Dirac-electron wave in graphene can be manipulated by
a circular gated region acting as a quatum dot. Large dots enable electron
lensing, while for smaller dots resonant scattering entails electron
confinement in quasibound states. Forward scattering and Klein tunneling can be
almost switched off for small dots by a Fano resonance arising from the
interference between resonant scattering and the background partition.


title: Tachyon motion in a black hole gravitational field

abstract:
  The motion of superluminal particles in the gravitational field of a
non-rotating black hole is analyzed. The relativistic Hamilton-Jacobi equation
is solved for particles with imaginary rest mass. It is shown that there are no
stable circular orbits and generally no finite motions for tachyons in the
Schwarzschild metric and that all unstable circular tachyon orbits lie in a
region extending from the gravitational radius to 1.5 times that radius. The
particles with speeds exceeding the speed of light are noticed to be able to
escape from the space limited by the gravitational radius. The results also
indicate that low-energy tachyons near a black hole may acquire higher energies
and that this in turn may lead to observable effects.


title: On a sum of modified Bessel functions

abstract:
  In this paper we consider a sum of modified Bessel functions of the first
kind of which particular case is used in the study of Kanter's sharp modified
Bessel function bound for concentrations of some sums of independent symmetric
random vectors. We present some monotonicity and convexity properties for that
sum of modified Bessel functions of the first kind, as well as some Tur\'an
type inequalities, lower and upper bounds. Moreover, we point out an error in
Kanter's paper [Ka] and at the end of the paper we pose an open problem, which
may be of interest for further research.


title: Del Pezzo Surfaces in Weighted Projective Spaces

abstract:
  We study singular del Pezzo surfaces that are quasi-smooth and well-formed
weighted hypersurfaces. We give an algorithm how to classify all of them.


title:
The effect of inertia on the Dirac electron, the spin Hall current and
  the momentum space Berry curvature

abstract:
  We have studied the spin dependent force and the associated momentum space
Berry curvature in an accelerating system. The results are derived by taking
into consideration the non relativistic limit of a generally covariant Dirac
equation under the presence of electromagnetic field where the methodology of
Foldy-Wouthuysen transformation is applied to achieve the non relativistic
limit. Spin currents appear due to the combined action of the external electric
field, crystal field and the induced inertial electric field via the total
effective spin-orbit interaction. In an accelerating frame, the crucial role of
momentum space Berry curvature in the spin dynamics has also been addressed
from the perspective of spin Hall conductivity. For time dependent
acceleration, the expression for the spin polarization has been derived.


title: Integral representations and summations of modified Struve function

abstract:
  It is known that Struve function $\mathbf H_\nu$ and modified Struve function
$\mathbf L_\nu$ are closely connected to Bessel function of the first kind
$J_\nu$ and to modified Bessel function of the first kind $I_\nu$ and possess
representations through higher transcendental functions like generalized
hypergeometric ${}_1F_2$ and Meijer $G$ function. Also, the NIST project and
Wolfram formula collection contain a set of Kapteyn type series expansions for
$\mathbf L_\nu(x)$. In this paper firstly, we obtain various another type
integral representation formulae for $\mathbf L_\nu(x)$ using the technique
developed by D. Jankov and the authors. Secondly, we present some summation
results for different kind of Neumann, Kapteyn and Schl\"omilch series built by
$I_\nu(x)$ and $\mathbf L_\nu(x)$ which are connected by a Sonin--Gubler
formula, and by the associated modified Struve differential equation. Finally,
solving a Fredholm type convolutional integral equation of the first kind,
Bromwich--Wagner line integral expressions are derived for the Bessel function
of the first kind $J_\nu$ and for an associated generalized Schl\"omilch
series.


title: Far-ultraviolet Observations of the Taurus-Perseus-Auriga Complex

abstract:
  We have constructed a far-ultraviolet (FUV) continuum map of the
Taurus-Auriga-Perseus complex, one of the largest local associations of dark
clouds, by merging the two data sets of GALEX and FIMS, which made observations
at similar wavelengths. The FUV intensity varies significantly across the whole
region, but the diffuse FUV continuum is dominated by dust scattering of
stellar photons. A diffuse FUV background of $\sim$1000 CU is observed, part of
which may be attributable to the scattered photons of foreground FUV light,
located in front of the thick clouds. The fluorescent emission of molecular
hydrogen constitutes $\sim$10% of the total FUV intensity throughout the
region, generally proportional to the local continuum level. We have developed
a Monte Carlo radiative transfer code and applied it to the present clouds
complex to obtain the optical properties of dust grains and the geometrical
structures of the clouds. The albedo and the phase function asymmetry factor
were estimated to be $0.42^{+0.05}_{-0.05}$, and $0.47^{+0.11}_{-0.27}$,
respectively, in accordance with theoretical estimations as well as recent
observations. The distance and thickness of the four prominent clouds in this
complex were estimated using a single slab model applied individually to each
cloud. The results obtained were in good agreement with those from other
observations in the case of the Taurus cloud, as its geometrical structure is
rather simple. For other clouds, which were observed to have multiple
components, the results gave distances and thicknesses encompassing all
components of each cloud. The distance and thickness estimations were not
crucially sensitive to the exact values of the albedo and the phase function
asymmetry factor, while the locations of the bright field stars relative to the
clouds as initial photon sources seem to be the most important factor in the
process of fitting.


title:
Design of Compandor Based on Approximate the First-Degree Spline
  Function

abstract:
  In this paper, the approximation of the optimal compressor function using
spline function of the first-degree is done. For the companding quantizer
designed on the basis of the approximative spline function of the first-degree,
the support region is numerically optimized to provide the minimum of the total
distortion for the last segment. It is shown that the companding quantizer with
the optimized support region threshold provides the signal to quantization
noise ratio that is very close to the one of the optimal companding quantizer
having an equal number of levels.


title:
On the $\mathbb{F}_2$-linear relations of Mersenne Twister pseudorandom
  number generators

abstract:
  Sequence generators obtained by linear recursions over the two-element field
$\mathbb{F}_2$, i.e., $\mathbb{F}_2$-linear generators, are widely used as
pseudorandom number generators. For example, the Mersenne Twister MT19937 is
one of the most successful applications. An advantage of such generators is
that we can assess them quickly by using theoretical criteria, such as the
dimension of equidistribution with $v$-bit accuracy. To compute these
dimensions, several polynomial-time lattice reduction algorithms have been
proposed in the case of $\mathbb{F}_2$-linear generators.
  In this paper, in order to assess non-random bit patterns in dimensions that
are higher than the dimension of equidistribution with $v$-bit accuracy,we
focus on the relationship between points in the Couture--L'Ecuyer dual lattices
and $\mathbb{F}_2$-linear relations on the most significant $v$ bits of output
sequences, and consider a new figure of merit $N_v$ based on the minimum weight
of $\mathbb{F}_2$-linear relations whose degrees are minimal for $v$. Next, we
numerically show that MT19937 has low-weight $\mathbb{F}_2$-linear relations in
dimensions higher than 623, and show that some output vectors with specific
lags are rejected or have small $p$-values in the birthday spacings tests. We
also report that some variants of Mersenne Twister, such as WELL generators,
are significantly improved from the perspective of $N_v$.


title: Horrocks Correspondence on a Quadric Surface

abstract:
  We extend the Horrocks correspondence between vector bundles and cohomology
modules on the projective plane to the product of two projective lines. We
introduce a set of invariants for a vector bundle on the product of two
projective lines, which includes the first cohomology module of the bundle, and
prove that there is a one to one correspondence between these sets of
invariants and isomorphism classes of vector bundles without line bundle
summands.


title: Bimodular rubber buckles early in bending

abstract:
  A block of rubber eventually buckles under severe flexure, and several axial
wrinkles appear on the inner curved face of the bent block. Experimental
measurements reveal that the buckling occurs earlier ---at lower compressive
strains--- than expected from theoretical predictions. This paper shows that if
rubber is modeled as being bimodular, and specifically, as being stiffer in
compression than in tension, then flexure bifurcation happens indeed at lower
levels of compressive strain than predicted by previous investigations (these
included taking into account finite size effects, compressibility effects, and
strain-stiffening effects.) Here the effect of bimodularity is investigated
within the theory of incremental buckling, and bifurcation equations, numerical
methods, dispersion curves, and field variations are presented and discussed.
It is also seen that Finite Element Analysis software seems to be unable to
encompass in a realistic manner the phenomenon of bending instability for
rubber blocks.


title:
The Importance of Continuous Value Based Project Management in the
  Context of Requirements Engineering

abstract:
  Despite several scientific achievements in the last years, there are still a
lot of IT projects that fail. Researchers found that one out of five
IT-projects run out of time, budget or value. Major reasons for this failure
are unexpected economic risk factors that emerge during the runtime of
projects. In order to be able to identify emerging risks early and to
counteract reasonably, financial methods for a continuous IT-project-steering
are necessary, which as of today to the best of our knowledge are missing
within scientific literature.


title: Neutrino emissivity of anisotropic neutron superfluids

abstract:
  We examine the influence of the anisotropy of the superfluid energy gap and
residual Fermi-liquid interactions in the triplet-correlated neutron liquid
onto neutrino energy losses through neutral weak currents. The neutrino-pair
emission caused by the pair breaking and formation processes and by the
spin-wave decays is considered for the case of the $^{3}P_{2}$ pairing in the
state with $m_{j}=0$. The simple analytical formulae are obtained. A comparison
with the previous results of the average-angle approach shows that the gap
anisotropy leads to quenching of the neutrino emissivity caused by the pair
recombination processes on about 15% and to substantial suppression of the
spin-wave decays. Residual particle-hole interactions increase the energy
losses in both the channels on about 5%.


title: Orbital magnetism of graphene flakes

abstract:
  Orbital magnetism is studied for graphene flakes with various shapes and edge
configurations using the tight-binding approximation. In the low-temperature
regime where the thermal energy is much smaller than to the energy level
spacing, the susceptibility rapidly changes between diamagnetism and
paramagnetism as a function of Fermi energy, in accordance with the energy
level structure. The susceptibility at charge neutral point is generally larger
in armchair flake than in zigzag flake, and larger in hexagonal flake than in
triangular flake. As the temperature increases, the discrete structures due to
the quantum confinement are all gone, and the susceptibility approximates the
bulk limit independently of the atomic configuration. The diamagnetic current
circulates entirely on the graphene flake at zero temperature, while in
increasing temperature it is localized near the edge with the characteristic
depth proportional to 1/T. We predict that the diamagnetism of graphene can be
observed using the alignment of graphene flakes in a feasible range of magnetic
field.


title: Multi-Planet Destabilisation and Escape in Post-Main Sequence Systems

abstract:
  Discoveries of exoplanets orbiting evolved stars motivate critical
examinations of the dynamics of $N$-body systems with mass loss. Multi-planet
evolved systems are particularly complex because of the mutual interactions
between the planets. Here, we study the underlying dynamical mechanisms which
can incite planetary escape in two-planet post-main sequence systems. Stellar
mass loss alone is unlikely to be rapid and high enough to eject planets at
typically-observed separations. However, the combination of mass loss and
planet-planet interactions can prompt a shift from stable to chaotic regions of
phase space. Consequently, when mass loss ceases, the unstable configuration
may cause escape. By assuming a constant stellar mass loss rate, we utilize
maps of dynamical stability to illustrate the distribution of regular and
chaotic trajectories in phase space. We show that chaos can drive the planets
to undergo close encounters, leading to the ejection of one planet. Stellar
mass loss can trigger the transition of a planetary system from a stable to
chaotic configuration, subsequently causing escape. We find that mass loss
non-adiabatically affects planet-planet interaction for the most massive
progenitor stars which avoid the supernova stage. For these cases, we present
specific examples of planetary escape.


title: Extending structures for Lie algebras

abstract:
  Let $\mathfrak{g}$ be a Lie algebra, $E$ a vector space containing
$\mathfrak{g}$ as a subspace. The paper is devoted to the \emph{extending
structures problem} which asks for the classification of all Lie algebra
structures on $E$ such that $\mathfrak{g}$ is a Lie subalgebra of $E$. A
general product, called the unified product, is introduced as a tool for our
approach. Let $V$ be a complement of $\mathfrak{g}$ in $E$: the unified product
$\mathfrak{g} \,\natural \, V$ is associated to a system $(\triangleleft, \,
\triangleright, \, f, \{-, \, -\})$ consisting of two actions $\triangleleft$
and $\triangleright$, a generalized cocycle $f$ and a twisted Jacobi bracket
$\{-, \, -\}$ on $V$. There exists a Lie algebra structure $[-,-]$ on $E$
containing $\mathfrak{g}$ as a Lie subalgebra if and only if there exists an
isomorphism of Lie algebras $(E, [-,-]) \cong \mathfrak{g} \,\natural \, V$.
All such Lie algebra structures on $E$ are classified by two cohomological type
objects which are explicitly constructed. The first one ${\mathcal
H}^{2}_{\mathfrak{g}} (V, \mathfrak{g})$ will classify all Lie algebra
structures on $E$ up to an isomorphism that stabilizes $\mathfrak{g}$ while the
second object ${\mathcal H}^{2} (V, \mathfrak{g})$ provides the classification
from the view point ofthe extension problem. Several examples that compute both
classifying objects ${\mathcal H}^{2}_{\mathfrak{g}} (V, \mathfrak{g})$ and
${\mathcal H}^{2} (V, \mathfrak{g})$ are worked out in detail in the case of
flag extending structures.


title: An Essay on the Double Nature of the Probability

abstract:
  Classical statistics and Bayesian statistics refer to the frequentist and
subjective theories of probability respectively. Von Mises and De Finetti, who
authored those conceptualizations, provide interpretations of the probability
that appear incompatible. This discrepancy raises ample debates and the
foundations of the probability calculus emerge as a tricky, open issue so far.
Instead of developing philosophical discussion, this research resorts to
analytical and mathematical methods. We present two theorems that sustain the
validity of both the frequentist and the subjective views on the probability.
Secondly we show how the double facets of the probability turn out to be
consistent within the present logical frame.


title: Periodic ordering of clusters in a one-dimensional lattice model

abstract:
  A generic lattice model for systems containing particles interacting with
short-range attraction long-range repulsion (SALR) potential that can be solved
exactly in one dimension is introduced. We assume attraction J_1 between the
first neighbors and repulsion J_2 between the third neighbors. The ground state
of the model shows existence of two homogeneous phases (gas and liquid) for
J_2/J_1<1/3. In addition to the homogeneous phases, the third phase with
periodically distributed clusters appears for J_2/J_1>1/3. Phase diagrams
obtained in the self-consistent mean-field approximation for a range of values
of J_2/J_1 show very rich behavior, including reentrant melting, and
coexistence of two periodic phases (one with strong and the other one with weak
order) terminated at a critical point. We present exact solutions for the
equation of state as well as for the correlation function for characteristic
values of J_2/J_1. Based on the exact results, for J_2/J_1>1/3 we predict
pseudo-phase transitions to the ordered cluster phase indicated by a rapid
change of density for a very narrow range of pressure, and by a very large
correlation length for thermodynamic states where the periodic phase is stable
in mean field. For 1/9<J_2/J_1<1/3 the correlation function decays
monotonically below certain temperature, whereas above this temperature
exponentially damped oscillatory behavior is obtained. Thus, even though
macroscopic phase separation is energetically favored and appears for weak
repulsion at T=0, local spatial inhomogeneities appear for finite T. Monte
Carlo simulations in canonical ensemble show that specific heat has a maximum
for low density \rho that we associate with formation of living clusters, and
if the repulsion is strong, another maximum for \rho = 1/2.


title: The mass and radius evolution of globular clusters in tidal fields

abstract:
  We present a simple theory for the evolution of initially compact clusters in
a tidal field. The fundamental ingredient of the model is that a cluster
conducts a constant fraction of its own energy through the half-mass radius by
two-body interactions every half-mass relaxation time. This energy is produced
in a self-regulative way in the core by an (unspecified) energy source. We find
that the half-mass radius increases during the first part (roughly half) of the
evolution and decreases in the second half, while the escape rate is constant
and set by the tidal field. We present evolutionary tracks and isochrones for
clusters in terms of cluster half-mass density, cluster mass and
galacto-centric radius. We find substantial agreement between model isochrones
and Milky Way globular cluster parameters, which suggests that there is a
balance between the flow of energy and the central energy production for almost
all globular clusters. We also find that the majority of the globular clusters
are still expanding towards their tidal radius. Finally, a fast code for
cluster evolution is presented.


title:
Two-parametric hyperbolic octagons and reduced Teichmueller space in
  genus two

abstract:
  It is explored a model of compact Riemann surfaces in genus two, represented
geometrically by two-parametric hyperbolic octagons with an order four
automorphism. We compute the generators of associated isometry group and give a
real-analytic description of corresponding Teichm\"uller space, parametrized by
the Fenchel-Nielsen variables, in terms of geometric data. We state the
structure of parameter space by computing the Weil-Petersson symplectic
two-form and analyzing the isoperimetric orbits. The results of the paper may
be interesting due to their applications to the quantum geometry, chaotic
systems and low-dimensional gravity.


title: One-dimensional degenerate diffusion operators

abstract:
  The aim of this paper is to present some results about generation,
sectoriality and gradient estimates both for the semigroup and for the
resolvent of suitable realizations of the operators [\Ab u(x)=\gamma xu"(x) + b
u'(x),] with constants $\gamma >0$ and $b\geq 0$, in the space $C([0,\infty])$


title:
Experimental Verification of the Spectral Shift between Near- and
  Far-Field Peak Intensities of Plasmonic Nanoantennas

abstract:
  Theory predicts a distinct spectral shift between the near- and far-field
optical responses of plasmonic antennas. Here we combine near-field optical
microscopy and far-field spectroscopy of individual infrared-resonant
nanoantennas to verify experimentally this spectral shift. Numerical
calculations corroborate our experimental results. We furthermore discuss the
implications of this effect in surface-enhanced infrared spectroscopy (SEIRS).


title:
Analyticity for some degenerate evolution equations defined on domains
  with corners

abstract:
  We study the analyticity of the semigroups generated by some classes of
degenerate second order differential operators in the space of continuous
function on a domain with corners. These semigroups arise from the theory of
dynamics of populations.


title:
Recurrence and transience of critical branching processes in random
  environment with immigration and an application to excited random walks

abstract:
  We establish recurrence and transience criteria for critical branching
processes in random environment with immigration. These results are then
applied to discuss recurrence and transience of a recurrent random walk in a
random environment on Z that will be disturbed by cookies inducing a drift to
the right of strength 1.


title:
Spread spectrum compressed sensing MRI using chirp radio frequency
  pulses

abstract:
  Compressed sensing has shown great potential in reducing data acquisition
time in magnetic resonance imaging (MRI). Recently, a spread spectrum
compressed sensing MRI method modulates an image with a quadratic phase. It
performs better than the conventional compressed sensing MRI with variable
density sampling, since the coherence between the sensing and sparsity bases
are reduced. However, spread spectrum in that method is implemented via a shim
coil which limits its modulation intensity and is not convenient to operate. In
this letter, we propose to apply chirp (linear frequency-swept) radio frequency
pulses to easily control the spread spectrum. To accelerate the image
reconstruction, an alternating direction algorithm is modified by exploiting
the complex orthogonality of the quadratic phase encoding. Reconstruction on
the acquired data demonstrates that more image features are preserved using the
proposed approach than those of conventional CS-MRI.


title:
Decoherence of a single-ion qubit immersed in a spin-polarized atomic
  bath

abstract:
  We report on the immersion of a spin-qubit encoded in a single trapped ion
into a spin-polarized neutral atom environment, which possesses both continuous
(motional) and discrete (spin) degrees of freedom. The environment offers the
possibility of a precise microscopic description, which allows us to understand
dynamics and decoherence from first principles. We observe the spin dynamics of
the qubit and measure the decoherence times (T1 and T2), which are determined
by the spin-exchange interaction as well as by an unexpectedly strong
spin-nonconserving coupling mechanism.


title: On $p$-adic colligations and 'rational maps' of Bruhat-Tits trees

abstract:
  Consider matrices of order $k+N$ over $p$-adic field determined up to
conjugations by elements of $GL$ over $p$-adic integers. We define a product of
such conjugacy classes and construct the analog of characteristic functions
(transfer functions), they are maps from Bruhat-Tits trees to Bruhat-Tits
buildings. We also examine categorical quotient for usual operator
colligations.


title: Seidel elements and potential functions of holomorphic disc counting

abstract:
  Let M be a symplectic manifold equipped with a Hamiltonian circle action and
let L be an invariant Lagrangian submanifold of M. We study the problem of
counting holomorphic disc sections of the trivial M-bundle over a disc with
boundary in L through degeneration. We obtain a conjectural relationship
between the potential function of L and the Seidel element associated to the
circle action. When applied to a Lagrangian torus fibre of a semi-positive
toric manifold, this degeneration argument reproduces a conjecture (now a
theorem) of Chan-Lau-Leung-Tseng relating certain correction terms appearing in
the Seidel elements with the potential function.


title: Data Storage: Review of Heusler Compounds

abstract:
  In the recent decade, the family of Heusler compounds has attracted
tremendous scientific and technological interest in the field of spintronics.
This is essentially due to their exceptional magnetic properties, which qualify
them as promising functional materials in various data-storage devices, such as
giant-magnetoresistance spin valves, magnetic tunnel junctions, and
spin-transfer torque devices. In this article, we provide a comprehensive
review on the applications of the Heusler family in magnetic data storage. In
addition to their important roles in the performance improvement of these
devices, we also try to point out the challenges as well as possible solutions,
of the current Heusler-based devices. We hope that this review would spark
further investigation efforts into efficient incorporation of this eminent
family of materials into data storage applications by fully arousing their
intrinsic potential.


title:
SPORT: A new sub-nanosecond time-resolved instrument to study swift
  heavy ion-beam induced luminescence - Application to luminescence degradation
  of a fast plastic scintillator

abstract:
  We developed a new sub-nanosecond time-resolved instrument to study the
dynamics of UV-visible luminescence under high stopping power heavy ion
irradiation. We applied our instrument, called SPORT, on a fast plastic
scintillator (BC-400) irradiated with 27-MeV Ar ions having high mean
electronic stopping power of 2.6 MeV/\mu m. As a consequence of increasing
permanent radiation damages with increasing ion fluence, our investigations
reveal a degradation of scintillation intensity together with, thanks to the
time-resolved measurement, a decrease in the decay constant of the
scintillator. This combination indicates that luminescence degradation
processes by both dynamic and static quenching, the latter mechanism being
predominant. Under such high density excitation, the scintillation
deterioration of BC-400 is significantly enhanced compared to that observed in
previous investigations, mainly performed using light ions. The observed
non-linear behaviour implies that the dose at which luminescence starts
deteriorating is not independent on particles' stopping power, thus
illustrating that the radiation hardness of plastic scintillators can be
strongly weakened under high excitation density in heavy ion environments.


title: Obtaining |V(ub)| exclusively: a theoretical perspective

abstract:
  We briefly review the recent progress in the exclusive determination of
|V(ub)| using QCD sum rules on the light cone.


title: A class of conformal curves in the Reissner-Nordstr\"om spacetime

abstract:
  A class of curves with special conformal properties (conformal curves) is
studied on the Reissner-Nordstr\"om spacetime. It is shown that initial data
for the conformal curves can be prescribed so that the resulting congruence of
curves extends smoothly to future and past null infinity. The formation of
conjugate points on these congruences is examined. The results of this analysis
are expected to be of relevance for the discussion of the Reissner-Nordstr\"om
spacetime as a solution to the conformal field equations and for the global
numerical evaluation of static black hole spacetimes.


title: Revival times at quantum phase transitions

abstract:
  The concept of quantum revivals is extended to many-body systems and the
implications of traversing a quantum phase transition are explored. By
analyzing two different models, the vibron model for the bending of polyatomic
molecules and the Dicke model for a quantum radiation field interacting with a
system of two-level atoms, we show evidence of revival behavior for wave
packets centered around energy levels as low as the fundamental state. Away
from criticality, revival times exhibit smooth, nonsingular behavior, and are
proportional to the system size. Upon approaching a quantum critical point,
they diverge as a power law and scale with the system size, although the
scaling is no longer linear.


title: Horava-Lifshitz early universe phase transition beyond detailed balance

abstract:
  The early universe is believed to have undergone a QCD phase transition to
hadrons at about $10\mu s$ after the big bang. We study such a transition in
the context of the non-detailed balance Horava-Lifshitz theory by investigating
the effects of the dynamical coupling constant $\lambda$ in a flat universe.
The evolution of the relevant physical quantities, namely the energy density
$\rho$, temperature $T$, scale factor $a$ and the Hubble parameter $H$ is
investigated before, during and after the phase transition, assumed to be of
first order. Also, in view of the recent lattice QCD simulations data, we study
a cross-over phase transition of the early universe whose results are based on
two different sets of lattice data.


title: A fluctuation relation for weakly ergodic aging systems

abstract:
  A fluctuation relation for aging systems is introduced, and verified by
extensive numerical simulations. It is based on the hypothesis of partial
equilibration over phase space regions in a scenario of entropy-driven
relaxation. The relation provides a simple alternative method, amenable of
experimental implementation, to measure replica symmetry breaking parameters in
aging systems. The connection with the effective temperatures obtained from the
fluctuation-dissipation theorem is discussed.


title:
Temperature control of local magnetic anisotropy in multiferroic
  CoFe/BaTiO3

abstract:
  This paper reports on the temperature evolution of local elastic interactions
between ferromagnetic CoFe films and ferroelectric BaTiO3 substrates.
Polarization microscopy measurements indicate that growth-induced stripe
domains in the CoFe films are preserved and strengthened during cooling and
heating through the structural phase transitions of BaTiO3. Moreover, rotation
of the magnetic easy axes at the tertragonal-to-orthorhombic transition (T =
278 K) and at T = 380 K simultaneously switches the local magnetization of both
uniaxial domains by 90 degrees. Irreversible changes in the ferromagnetic
domain pattern are induced when the room-temperature ferroelectric domain
structure is altered after temperature cycling.


title:
The rise of an ionized wind in the Narrow Line Seyfert 1 Galaxy Mrk 335
  observed by XMM-Newton and HST

abstract:
  We present the discovery of an outflowing ionized wind in the Seyfert 1
Galaxy Mrk 335. Despite having been extensively observed by most of the largest
X-ray observatories in the last decade, this bright source was not known to
host warm absorber gas until recent XMM-Newton observations in combination with
a long-term Swift monitoring program have shown extreme flux and spectral
variability. High resolution spectra obtained by the XMM-Newton RGS detector
reveal that the wind consists of three distinct ionization components, all
outflowing at a velocity of 5000 km/s. This wind is clearly revealed when the
source is observed at an intermediate flux state (2-5e-12 ergs cm^-2 s^-1). The
analysis of multi-epoch RGS spectra allowed us to compare the absorber
properties at three very different flux states of the source. No correlation
between the warm absorber variability and the X-ray flux has been determined.
The two higher ionization components of the gas may be consistent with
photoionization equilibrium, but we can exclude this for the only ionization
component that is consistently present in all flux states (log(xi)~1.8). We
have included archival, non-simultaneous UV data from HST (FOS, STIS, COS) with
the aim of searching for any signature of absorption in this source that so far
was known for being absorption-free in the UV band. In the COS spectra obtained
a few months after the X-ray observations we found broad absorption in CIV
lines intrinsic to the AGN and blueshifted by a velocity roughly comparable to
the X-ray outflow. The global behavior of the gas in both bands can be
explained by variation of the covering factor and/or column density, possibly
due to transverse motion of absorbing clouds moving out of the line of sight at
Broad Line Region scale.


title: Almost reduction and perturbation of matrix cocycles

abstract:
  In this note, we show that if all Lyapunov exponents of a matrix cocycle
vanish, then it can be perturbed to become cohomologous to a cocycle taking
values in the orthogonal group. This extends a result of Avila, Bochi and
Damanik to general base dynamics and arbitrary dimension. We actually prove a
fibered version of this result, and apply it to study the existence of
dominated splittings into conformal subbundles of general matrix cocycles.


title:
Optimizing the search for resources by sharing information: Mongolian
  gazelles as a case study

abstract:
  We investigate the relationship between communication and search efficiency
in a biological context by proposing a model of Brownian searchers with
long-range pairwise interaction. After a general study of the properties of the
model, we show an application to the particular case of acoustic communication
among Mongolian gazelle, for which data are available, searching for good
habitat areas. Using Monte Carlo simulations and density equations, our results
point out that the search is optimal (i.e. the mean first hitting time among
searchers is minimum) at intermediate scales of communication, showing that
both an excess and a lack of information may worsen it.

categories: physics.bio-ph cond-mat.stat-mech nlin.AO q-bio.PE


title: Superconductivity in Sulfur-Doped Amorphous Carbon Films

abstract:
  Following our previous investigations on superconductivity in amorphous
carbon (aC) based systems; we have prepared thin composite aC-W films using
electron-beam induced deposition. The films did not show any sign for
superconductivity above 5 K. However, local, non-percolative, superconductivity
emerged at Tc = 34.4 K after treatment with sulfur at 250 C for 24 hours. The
superconducting features in the magnetization curves were by far sharper
compared to our previous results, and the shielding fraction increased by about
an order of magnitude. Our data suggest that pairing and localized
superconductivity take place in the aC-S regions, whereas phase coherence,
assisted by the W inclusions, was enhanced compared to our previous samples,
yet still not to the degree of achieving global phase-coherence and percolating
superconductivity.