bluuebunny/crossref_metadata_2025 huggingface dataset:
Lorentzian Darboux images of curves on spacelike surfaces in Lorentz–Minkowski 3-space
Authors: Ito Noriaki , Izumiya Shyuichi
Published: February 2016

For a regular curve on a spacelike surface in Lorentz–Minkowski [Formula: see text]-space, we have a moving frame along the curve which is called a Lorentzian Darboux frame. We introduce five special vector fields along the curve associated to the Lorentzian Darboux frame and investigate their singularities.
F-Index of some graph operations
Authors: De Nilanjan , Nayeem Sk. Md. Abu , Pal Anita
Published: February 2016

The F-index of a graph is defined as the sum of cubes of the vertex degrees of the graph. This was introduced in 1972, in the same paper where the first and second Zagreb indices were introduced to study the structure-dependency of total [Formula: see text]-electron energy. But this topological index was not further studied till then. Very recently, Furtula and Gutman [A forgotten topological index,J. Math. Chem. 53(4) (2015) 1184–1190.] reinvestigated the index and named it “forgotten topological index” or “F-index”. In that paper, they present some basic properties of this index and showed that this index can enhance the physico-chemical applicability of Zagreb index. Here, we study the behavior of this index under several graph operations and apply our results to find the F-index of different chemically interesting molecular graphs and nanostructures.
Characterization of zigzag De Morgan functions
Authors: Aslanyan V. A.
Published: February 2016

Post’s functional completeness theorem for Boolean functions plays an important role in discrete mathematics. In paper [A functional completeness theorem for De Morgan functions, Discrete Appl. Math. 162 (2014) 1–16, doi: 10.1016/j.dam.2013.08.006.] a functional completeness criterion for De Morgan functions is established by the present author and Yu. Movsisyan. Namely, the concepts of closed, complete and precomplete classes of De Morgan functions are introduced there and a functional completeness theorem for De Morgan functions is proven. As a result it is shown that there are five precomplete classes of De Morgan functions. Four of those are defined as sets of functions preserving some finitary relations. However, the fifth class — the class of zigzag De Morgan functions, is not defined by relations. In this paper, we prove that zigzag De Morgan functions can be defined as De Morgan functions preserving an atmost 16-ary relation.
Communication is Bounded by Root of Rank
Authors: Lovett Shachar
Published: February 2016

We prove that any total boolean function of rank
r
can be computed by a deterministic communication protocol of complexity
O
(√ ċ log(
r
)). Equivalently, any graph whose adjacency matrix has rank
r
has chromatic number at most 2

O
(√
r
ċlog(
r
))

. This gives a nearly quadratic improvement in the dependence on the rank over previous results.
Removing and Adding Edges for the Traveling Salesman Problem
Authors: Mömke Tobias , Svensson Ola
Published: February 2016

We present a framework for approximating the metric TSP based on a novel use of matchings. Traditionally, matchings have been used to add edges to make a given graph Eulerian, whereas our approach also allows for the removal of certain edges leading to a decreased cost.

For the TSP on graphic metrics (graph-TSP), we show that the approach gives a 1.461-approximation algorithm with respect to the Held-Karp lower bound. For graph-TSP restricted either to half-integral solutions to the Held-Karp relaxation or to a class of graphs that contains subcubic and claw-free graphs, we show that the integrality gap of the Held-Karp relaxation matches the conjectured ratio 4/3. The framework also allows for generalizations in a natural way and leads to analogous results for the
s
,
t
-path traveling salesman problem on graphic metrics where the start and end vertices are prespecified.
The Minset-Poset Approach to Representations of Graph Connectivity
Authors: Gabow Harold N.
Published: February 2016

Various instances of the minimal-set poset (minset-poset for short) have been proposed in the literature, e.g., the representation of Picard and Queyranne for all
st
-minimum cuts of a flow network. We begin with an explanation of why this poset structure is common. We show any family of sets
F
that can be defined by a “labelling algorithm” (e.g., the Ford-Fulkerson labelling algorithm for maximum network flow) has an algorithm that constructs the minset poset for
F
. We implement this algorithm to efficiently find the nodes of the poset when
F
is the family of minimum edge cuts of an unweighted graph; we also give related algorithms to construct the entire poset for weighted graphs. The rest of the article discusses applications to edge- and vertex connectivity, both combinatorial and algorithmic, that we now describe.

For digraphs, a natural interpretation of the minset poset represents all minimum edge cuts. In the special case of undirected graphs, the minset poset is proved to be a variant of the well-known cactus representation of all mincuts. We use the poset algorithms to construct the cactus representation for unweighted graphs in time
O
(
m
+λ
2
n
log (n/λ)) (λ is the edge connectivity) improving the previous bound
O
(λ
n
2
) for all but the densest graphs. We also construct the cactus representation for weighted graphs in time
O
(
nm
log(
n
2
/
m
)), the same bound as a previously known algorithm but in linear space
O
(
m
). The latter bound also holds for constructing the minset poset for any weighted digraph; the former bound also holds for constructing the nodes of that poset for any unweighted digraph. The poset is used in algorithms to increase the edge connectivity of a graph by adding the fewest edges possible. For directed and undirected graphs, weighted and unweighted, we achieve the time of the preceding two bounds, i.e., essentially the best-known bounds to compute the edge connectivity itself. Some constructions of minset posets for graph rigidity are also sketched.

For vertex connectivity, the minset poset is proved to be a slight variant of the dominator tree. This leads to an algorithm to construct the dominator tree in time
O
(
m
) on a RAM. (The algorithm is included in the appendix, since other linear-time algorithms of similar simplicity have recently been presented.)
Structure Design of Wireless Sensor Nodes with Energy and Cost Awareness for Multichannel Signal Measurement
Authors: Zhu Zhenhuan , Oyadiji S. Olutunde
Published: February 2016

This article aims to develop a design pattern of a wireless sensor node working in multichannel signal measurement for effectively lowering energy consumption and cost. The proposed design pattern enables the architecture of a wireless sensor node to adapt to application requirements, thus to significantly reduce system redundancy. Two multisensor structures are parameterized regarding frequency response, power consumption, and cost. The system design pattern provides flexibility through three proposed interface circuits that bridge between multisensor structures and the microprocessors inside sensor nodes. It also allows adjusting time the delay parameter that can enlarge the selection range of main electronic components, and thereby increases the robustness of the model for practical implementations. A virtual case study is provided to demonstrate how to apply this model into an application design.
An Optimal Ancestry Labeling Scheme with Applications to XML Trees and Universal Posets
Authors: Fraigniaud Pierre , Korman Amos
Published: February 2016

In this article, we solve the
ancestry
-labeling scheme problem, which aims at assigning the shortest possible labels (bit strings) to nodes of rooted trees, so ancestry queries between any two nodes can be answered by inspecting their assigned labels only. This problem was introduced more than 20 years ago by Kannan et al. [1988] and is among the most well-studied problems in the field of informative labeling schemes. We construct an ancestry-labeling scheme for
n
-node trees with label size log
2
n
+
O
(log log
n
) bits, thus matching the log
2
n
+ Ω(log log
n
) bits lower bound given by Alstrup et al. [2003]. Our scheme is based on a simplified ancestry scheme that operates extremely well on a restricted set of trees. In particular, for the set of
n
-node trees with a depth of at most
d
, the simplified ancestry scheme enjoys label size of log
2
n
+ 2log
2
d
+
O
(1) bits. Since the depth of most XML trees is at most some small constant, such an ancestry scheme may be of practical use. In addition, we also obtain an
adjacency
-labeling scheme that labels
n
-node trees of depth
d
with labels of size log
2
n
+ 3log
2
d
+
O
(1) bits. All our schemes assign the labels in linear time, and guarantee that any query can be answered in constant time.

Finally, our ancestry scheme finds applications to the construction of small
universal
partially ordered sets (posets). Specifically, for any fixed integer
k
, it enables the construction of a universal poset of size
Õ
(

n
k

) for the family of
n
-element posets with a tree dimension of at most
k
. Up to lower-order terms, this bound is tight thanks to a lower bound of
n

k
−
o
(1)

by to Alon and Scheinerman [1988].
Generating Incremental Length Summary Based on Hierarchical Topic Coverage Maximization
Authors: Ye Jintao , Ming Zhao Yan , Chua Tat Seng
Published: February 2016

Document summarization is playing an important role in coping with information overload on the Web. Many summarization models have been proposed recently, but few try to adjust the summary length and sentence order according to application scenarios. With the popularity of handheld devices, presenting key information first in summaries of flexible length is of great convenience in terms of faster reading and decision-making and network consumption reduction. Targeting this problem, we introduce a novel task of generating summaries of incremental length. In particular, we require that the summaries should have the ability to automatically adjust the coverage of general-detailed information when the summary length varies. We propose a novel summarization model that incrementally maximizes topic coverage based on the document’s hierarchical topic model. In addition to the standard Rouge-1 measure, we define a new evaluation metric based on the similarity of the summaries’ topic coverage distribution in order to account for sentence order and summary length. Extensive experiments on Wikipedia pages, DUC 2007, and general noninverted writing style documents from multiple sources show the effectiveness of our proposed approach. Moreover, we carry out a user study on a mobile application scenario to show the usability of the produced summary in terms of improving judgment accuracy and speed, as well as reducing the reading burden and network traffic.
Images of popular computing in the Eastern Mediterranean
Authors: Hemmendinger David
Published: February 2016

An exhibit of posters and a slide show of covers of popular computing magazines from Turkey, Greece, Cyprus, and Bulgaria accompanied the 2010 ItiCSE conference. This exhibit, supported by a SIGCSE Special Projects grant, provided one look at computing history in the eastern Mediterranean through the representations of covers of popular magazines for hobbyists and other computer users.
Reconciling Elastic and Equilibrium Methods for Static Analysis
Authors: Shin Hijung V. , Porst Christopher F. , Vouga Etienne , Ochsendorf John , Durand Frédo
Published: February 2016

We examine two widely used classes of methods for static analysis of masonry buildings: linear elasticity analysis using finite elements and equilibrium methods. It is often claimed in the literature that finite element analysis is less accurate than equilibrium analysis when it comes to masonry analysis; we examine and qualify this claimed inaccuracy, provide a systematic explanation for the discrepancy observed between their results, and present a unified formulation of the two approaches to stability analysis. We prove that both approaches can be viewed as equivalent, dual methods for getting the same answer to the same problem. We validate our observations with simulations and physical tilt experiments of structures.
Anytime Algorithms for Recommendation Service Providers
Authors: Ben-Shimon David , Rokach Lior , Shani Guy , Shapira Bracha
Published: February 2016

Recommender systems (RS) can now be found in many commercial Web sites, often presenting customers with a short list of additional products that they might purchase. Many commercial sites do not typically have the ability and resources to develop their own system and may outsource the RS to a third party. This had led to the growth of a recommendation as a service industry, where companies, referred to as RS providers, provide recommendation services. These companies must carefully balance the cost of building recommendation models and the payment received from the e-business, as these payments are expected to be low. In such a setting, restricting the computational time required for model building is critical for the RS provider to be profitable.

In this article, we propose anytime algorithms as an attractive method for balancing computational time and the recommendation model performance, thus tackling the RS provider problem. In an anytime setting, an algorithm can be stopped after any amount of computational time, always ensuring that a valid, although suboptimal, solution will be returned. Given sufficient time, however, the algorithm should converge to an optimal solution. In this setting, it is important to evaluate the quality of the returned solution over time, monitoring quality improvement. This is significantly different from traditional evaluation methods, which mostly estimate the performance of the algorithm only after its convergence is given sufficient time.

We show that the popular item-item top-N recommendation approach can be brought into the anytime framework by smartly considering the order by which item pairs are being evaluated. We experimentally show that the time-accuracy trade-off can be significantly improved for this specific problem.
Managing Server Clusters on Renewable Energy Mix
Authors: Li Chao , Wang Rui , Qian Depei , Li Tao
Published: February 2016

As climate change has become a global concern and server energy demand continues to soar, many IT companies have started to explore server clusters running on various renewable energy sources. Existing green data center designs often yield suboptimal performance as they only look at a certain specific type of energy source. This article explores data centers powered by hybrid renewable energy systems. We propose GreenWorks, a framework for HPC data centers running on a renewable energy mix. Specifically, GreenWorks features a cross-layer power management scheme tailored to the timing behaviors and capacity constraints of different energy sources. Using realistic workload traces and renewable energy data, we show that GreenWorks could provide a near-optimal workload performance (within 3% difference) on average. It can also reduce the worst-case performance degradation by 43% compared to the state-of-the-art design. Moreover, the performance improvements are based on carbon-neutral operations and are not at the cost of significant efficiency degradation and reduced battery lifecycle. Our technique becomes more efficient when servers become more energy proportional and can effectively handle the ever-increasing depth of renewable power penetration in green data centers.
Interactive Topic Modeling for Exploring Asynchronous Online Conversations
Authors: Hoque Enamul , Carenini Giuseppe
Published: February 2016

Since the mid-2000s, there has been exponential growth of asynchronous online conversations, thanks to the rise of social media. Analyzing and gaining insights from such conversations can be quite challenging for a user, especially when the discussion becomes very long. A promising solution to this problem is topic modeling, since it may help the user to understand quickly what was discussed in a long conversation and to explore the comments of interest. However, the results of topic modeling can be noisy, and they may not match the user’s current information needs. To address this problem, we propose a novel topic modeling system for asynchronous conversations that revises the model on the fly on the basis of users’ feedback. We then integrate this system with interactive visualization techniques to support the user in exploring long conversations, as well as in revising the topic model when the current results are not adequate to fulfill the user’s information needs. Finally, we report on an evaluation with real users that compared the resulting system with both a traditional interface and an interactive visual interface that does not support human-in-the-loop topic modeling. Both the quantitative results and the subjective feedback from the participants illustrate the potential benefits of our interactive topic modeling approach for exploring conversations, relative to its counterparts.
Well-Structured Futures and Cache Locality
Authors: Herlihy Maurice , Liu Zhiyu
Published: February 2016

In fork-join parallelism, a sequential program is split into a directed acyclic graph of tasks linked by directed dependency edges, and the tasks are executed, possibly in parallel, in an order consistent with their dependencies. A popular and effective way to extend fork-join parallelism is to allow threads to create futures. A thread creates a future to hold the results of a computation, which may or may not be executed in parallel. That result is returned when some thread touches that future, blocking if necessary until the result is ready.

Recent research has shown that although futures can, of course, enhance parallelism in a structured way, they can have a deleterious effect on cache locality. In the worst case, futures can incur Ω(
PT
∞
+
tT
∞
) deviations, which implies Ω (
CPT
∞
+
CtT
∞
) additional cache misses, where
C
is the number of cache lines,
P
is the number of processors,
t
is the number of touches, and
T
∞
is the computation span. Since cache locality has a large impact on software performance on modern multicores, this result is troubling.

In this article, we show that if futures are used in a simple, disciplined way, then the situation is much better: if each future is touched only once, either by the thread that created it or by a later descendant of the thread that created it, then parallel executions with work stealing can incur at most
O
(
CPT
2
∞
) additional cache misses—a substantial improvement. This structured use of futures is characteristic of many (but not all) parallel applications.
A Survey of Role Mining
Authors: Mitra Barsha , Sural Shamik , Vaidya Jaideep , Atluri Vijayalakshmi
Published: February 2016

Role-Based Access Control (RBAC) is the most widely used model for advanced access control deployed in diverse enterprises of all sizes. RBAC critically depends on defining roles, which are a functional intermediate between users and permissions. Thus, for RBAC to be effective, an appropriate set of roles needs to be identified. Since many organizations already have user-permission assignments defined in some form, it makes sense to identify roles from this existing information. This process, known as role mining, is one of the critical steps for successful RBAC adoption in any enterprise. In recent years, numerous role mining techniques have been developed, which take into account the characteristics of the core RBAC model, as well as its various extended features. In this article, we comprehensively study and classify the basic problem of role mining along with its several variants and the corresponding solution strategies. Categorization is done on the basis of the nature of the target RBAC system, the objective of role mining, and the type of solution. We then discuss the limitations of existing work and identify new areas of research that can lead to further enrichment of this field.
The Ethics of Computing
Authors: Stahl Bernd Carsten , Timmermans Job , Mittelstadt Brent Daniel
Published: February 2016

Computing technologies and artifacts are increasingly integrated into most aspects of our professional, social, and private lives. One consequence of this growing ubiquity of computing is that it can have significant ethical implications that computing professionals need to be aware of. The relationship between ethics and computing has long been discussed. However, this is the first comprehensive survey of the mainstream academic literature of the topic. Based on a detailed qualitative analysis of the literature, the article discusses ethical issues, technologies that they are related to, and ethical theories, as well as the methodologies that the literature employs, its academic contribution, and resulting recommendations. The article discusses general trends and argues that the time has come for a transition to responsible research and innovation to ensure that ethical reflection of computing has practical and manifest consequences.
On Memory Reuse Between Inputs and Outputs of Dataflow Actors
Authors: Desnos Karol , Pelcat Maxime , Nezan Jean-François , Aridhi Slaheddine
Published: February 2016

This article introduces a new technique to minimize the memory footprints of Digital Signal Processing (DSP) applications specified with Synchronous Dataflow (SDF) graphs and implemented on shared-memory Multiprocessor System-on-Chip (MPSoCs). In addition to the SDF specification, which captures data dependencies between coarse-grained tasks called actors, the proposed technique relies on two optional inputs abstracting the internal data dependencies of actors: annotations of the ports of actors, and script-based specifications of merging opportunities between input and output buffers of actors. Experimental results on a set of applications show a reduction of the memory footprint by 48% compared to state-of-the-art minimization techniques.
Toward Smart Embedded Systems
Authors: Dutt Nikil , Jantsch Axel , Sarma Santanu
Published: February 2016

Embedded systems must address a multitude of potentially conflicting design constraints such as resiliency, energy, heat, cost, performance, security, etc., all in the face of highly dynamic operational behaviors and environmental conditions. By incorporating elements of intelligence, the hope is that the resulting “smart” embedded systems will function correctly and within desired constraints in spite of highly dynamic changes in the applications and the environment, as well as in the underlying software/hardware platforms. Since terms related to “smartness” (e.g., self-awareness, self-adaptivity, and autonomy) have been used loosely in many software and hardware computing contexts, we first present a taxonomy of “self-x” terms and use this taxonomy to relate major “smart” software and hardware computing efforts. A major attribute for smart embedded systems is the notion of self-awareness that enables an embedded system to monitor its own state and behavior, as well as the external environment, so as to adapt intelligently. Toward this end, we use a System-on-Chip perspective to show how the CyberPhysical System-on-Chip (CPSoC) exemplar platform achieves self-awareness through a combination of cross-layer sensing, actuation, self-aware adaptations, and online learning. We conclude with some thoughts on open challenges and research directions.
EduBits
Authors: Impagliazzo John , Timanovsky Yan , Zhang Ming
Published: February 2016

Welcome to the latest installment of "EduBits," your quarterly pipeline to new and exciting happenings in the world of ACM Education. In this edition, a preview of the third ACM Learning @ Scale conference; news from Tianjin, China on a recent summit on computing education; and an update on the progress of the CE2016 curricular volume in computer engineering.
News from the SIGs
Authors: Rodger Susan H. , Zilora Steve , Kasper George M.
Published: February 2016

Welcome once again to reports highlighting trends within the computing education community from three Special Interest Groups (SIGs) within ACM. One SIG focuses on computer science education (SIGCSE), another on information technology education (SIGITE), and another on management information systems (SIGMIS).
Parallel Inverse Kinematics for Multithreaded Architectures
Authors: Harish Pawan , Mahmudi Mentar , Callennec Benoît Le , Boulic Ronan
Published: February 2016

In this article, we present a parallel prioritized Jacobian-based inverse kinematics algorithm for multithreaded architectures. We solve damped least squares inverse kinematics using a parallel line search by identifying and sampling critical input parameters. Parallel competing execution paths are spawned for each parameter in order to select the optimum that minimizes the error criteria. Our algorithm is highly scalable and can handle complex articulated bodies at interactive frame rates. We show results on complex skeletons consisting of more than 600 degrees of freedom while being controlled using multiple end effectors. We implement the algorithm both on multicore and GPU architectures and demonstrate how the GPU can further exploit fine-grain parallelism not directly available on a multicore processor. Our implementations are 10 to 150 times faster compared to a state-of-the-art serial implementation while providing higher accuracy. We also demonstrate the scalability of the algorithm over multiple scenarios and explore the GPU implementation in detail.
Online Testing, Is It Fair?
Authors: Brown Brittni
Published: February 2016

Although online education has become mainstream, many critics still fear it is an unequal form of education primarily because cheating techniques are outstripping our means of monitoring students. Cheating does pose a serious problem to online education, but new technologies are capable of limiting the threat. In combination with a proactive teaching style, anti-cheating tech can clamp down on unethical behavior and create a school environment that is as honest as any in-class setting.
Dynamic system modeling of evolutionary algorithms
Authors: Šourek Gustav , Pošík Petr
Published: February 2016

Evolutionary algorithms are population-based, metaheuristic, black-box optimization techniques from the wider family of evolutionary computation. Optimization algorithms within this family are often based on similar principles and routines inspired by biological evolution. Due to their robustness, the scope of their application is broad and varies from physical engineering to software design problems. Despite sharing similar principles based in common biological inspiration, these algorithms themselves are typically viewed as black-box program routines by the end user, without a deeper insight into the underlying optimization process. We believe that shedding some light into the underlying routines of evolutionary computation algorithms can make them more accessible to wider engineering public.

In this paper, we formulate the evolutionary optimization process as a dynamic system simulation, and provide means to prototype evolutionary optimization routines in a visually comprehensible framework. The framework enables engineers to follow the same dynamic system modeling paradigm, they typically use for representation of their optimization problems, to also create the desired evolutionary optimizers themselves. Instantiation of the framework in a Matlab-Simulink library practically results in graphical programming of evolutionary optimizers based on data-flow principles used for dynamic system modeling within the Simulink environment. We illustrate the efficiency of visual representation in clarifying the underlying concepts on executable flow-charts of respective evolutionary optimizers and demonstrate features and potential of the framework on selected engineering benchmark applications.
Optimizing swap space for improving process response after system resume
Authors: Lo Shiwu , Lin Hung-Yi , Chen Zhengyuan
Published: February 2016

The swap-before-hibernate (SBH) swaps out all swappable pages before the system enters hibernation mode, thus reducing the memory used by the system and the size of hibernation file. However, when the system resumes, the program must be reloaded into the main memory by swap-in; hence, the response time of program depends on the swap-in speed.

This study experimentally proved that the present swap-in/swap-out mechanism of Linux is not acceptable to the SBH algorithm. Moreover, it proposed the method of reordering all the requests to be written out to the swap space. The proposed method was proven to increase the efficiency of swap space by 1/2 to 1/3.
Research workshop on algebraic representations in computer-aided design for complex shapes
Authors: Emiris Ioannis
Published: February 2016

This is the Kickoff Workshop of European Network ARCADES, and also serves as a Recruitment event for the Network's 13 open PhD positions. There is funding available for student participants.
Friend or Foe
Authors: Zhang Sixuan , Yu Liang , Wakefield Robin L. , Leidner Dorothy E.
Published: February 2016

As the use of social media technologies proliferates in organizations, it is important to understand the nefarious behaviors, such as cyberbullying, that may accompany such technology use and how to discourage these behaviors. We draw from neutralization theory and the criminological theory of general deterrence to develop and empirically test a research model to explain why cyberbullying may occur and how the behavior may be discouraged. We created a research model of three second-order formative constructs to examine their predictive influence on intentions to cyberbully. We used PLS- SEM to analyze the responses of 174 Facebook users in two different cyberbullying scenarios. Our model suggests that neutralization techniques enable cyberbullying behavior and while sanction certainty is an important deterrent, sanction severity appears ineffective. We discuss the theoretical and practical implications of our model and results.
Hybrid Predictor and Field-Biased Context Pixel Selection Based on PPVO
Authors: Xiang Hongyin , Yuan Jinsha , Hou Sizu
Published: February 2016

Most pixel-value-ordering (PVO) predictors generated prediction-errors including −1 and 1 in a block-by-block manner. Pixel-based PVO (PPVO) method provided a novel pixel scan strategy in a pixel-by-pixel way. Prediction-error bin 0 is expanded for embedding with the help of equalizing context pixels for prediction. In this paper, a PPVO-based hybrid predictor (HPPVO) is proposed as an extension. HPPVO predicts pixel in both positive and negative orientations. Assisted by expansion bins selection technique, this hybrid predictor presents an optimized prediction-error expansion strategy including bin 0. Furthermore, a novel field-biased context pixel selection is already developed, with which detailed correlations of around pixels are better exploited more than equalizing scheme merely. Experiment results show that the proposed HPPVO improves embedding capacity and enhances marked image fidelity. It also outperforms some other state-of-the-art methods of reversible data hiding, especially for moderate and large payloads.
Approach in Theory of Nonlinear Evolution Equations: The Vakhnenko-Parkes Equation
Authors: Vakhnenko V. O. , Parkes E. J.
Published: February 2016

A variety of methods for examining the properties and solutions of nonlinear evolution equations are explored by using the Vakhnenko equation (VE) as an example. The VE, which arises in modelling the propagation of high-frequency waves in a relaxing medium, has periodic and solitary traveling wave solutions some of which are loop-like in nature. The VE can be written in an alternative form, known as the Vakhnenko-Parkes equation (VPE), by a change of independent variables. The VPE has anN-soliton solution which is discussed in detail. Individual solitons are hump-like in nature whereas the corresponding solution to the VE comprisesN-loop-like solitons. Aspects of the inverse scattering transform (IST) method, as applied originally to the KdV equation, are used to find one- and two-soliton solutions to the VPE even though the VPE’s spectral equation is third-order and not second-order. A Bäcklund transformation for the VPE is used to construct conservation laws. The standard IST method for third-order spectral problems is used to investigate solutions corresponding to bound states of the spectrum and to a continuous spectrum. This leads toN-soliton solutions andM-mode periodic solutions, respectively. Interactions between these types of solutions are investigated.
Severe Sepsis due toClostridium perfringensBacteremia of Urinary Origin: A Case Report and Systematic Review
Authors: Millard Michael A. , McManus Kathleen A. , Wispelwey Brian
Published: February 2016

Clostridium perfringensbacteremia is an uncommon yet serious clinical syndrome that typically arises from a gastrointestinal source. However, clinicians should consider nongastrointestinal sources as well. We present a rare case ofC. perfringensbacteremia of urinary origin that required surgical intervention for definitive treatment. A 61-year-old male presented with acute nausea and vomiting, altered mental status, and chronic diarrhea. His physical exam revealed right costovertebral tenderness and his laboratory work-up revealed acute renal failure. Percutaneous blood cultures grewC. perfringens. Cross-sectional imaging revealed a right-sided ureteral stone with hydronephrosis, which required nephrostomy placement. On placement of the nephrostomy tube, purulent drainage was identified and Gram stain of the drainage revealed Gram-variable rods. A urinary source ofC. perfringenswas clinically supported. Although it is not a common presentation, nongastrointestinal sources such as a urinary source should be considered inC. perfringensbacteremia because failure to recognize a nongastrointestinal source can delay appropriate treatment, which may include surgical intervention.
The Effect of Periodontitis on Expression of Interleukin-21: A Systematic Review
Authors: Mootha Archana , Malaiappan Sankari , Jayakumar N. D. , Varghese Sheeja S. , Toby Thomas Julie
Published: February 2016

Purpose.Inflammation and tissue breakdown are led by an array of inflammatory destructive mediators associated with initiation and progression of inflammatory diseases like periodontitis. Current evidence shows that these inflammatory mediators have a definitive role in the pathogenesis of various systemic diseases with an inflammatory component. Interleukin-21 (IL-21) has been associated with systemic diseases like rheumatoid arthritis and Crohn’s disease that follow a chronic inflammatory cascade. Similarly recent studies have associated Interleukin-21 levels with periodontitis. This systematic review was aimed to assess the levels of IL-21 in subjects with periodontitis.Methods.A complete literature search was done in PubMed, Medline, Science Direct, and Cochrane databases and Google Scholar based on the inclusion/exclusion criteria. Six relevant articles were procured. Full text was read individually by two reviewers and data extraction was done based on STROBE statement.Results.After data extraction five observational and one interventional study were obtained. All the studies showed an increased expression of IL-21 in periodontitis and the interventional study showed reduction in IL-21 levels after nonsurgical periodontal therapy (NSP).Conclusion.Interleukin-21 levels are higher in periodontitis than controls. With this limited evidence further longitudinal studies are required to consider this as a definitive inflammatory marker.
Measurements of Pupillary Diameter and Wavefront Aberrations in Pregnant Women
Authors: Altay Yesim , Altay Mehmet Metin , Demirok Gulizar , Balta Ozgur , Bolu Hulya
Published: February 2016

Purpose. To show whether pregnancy affects the measurements of pupillary diameter and wavefront (WF) aberrations.Methods. This was a case-control study including 34 healthy pregnant women in the third trimester and age-matched 34 nonpregnant women. Only women who had no ocular abnormalities and no refractive error were included. We measured photopic and mesopic pupil diameter and WF aberrations at the third trimester and at the second postpartum month. Measurements of the right eyes were used in this study. The differences between groups were analysed by pairedt-test andt-test.Results. Pregnant women’s mean photopic pupil size in the third trimester was significantly higher than in postpartum period and in control group (3.74 ± 0.77, 3.45 ± 0.53, and 3.49 ± 0.15 mm,p<0.05, resp.). Mesopic pupil size in the third trimester was also higher than in postpartum period and in control group (6.77 ± 0.52, 6.42 ± 0.55, and 6.38 ± 0.21 mm,p<0.05, resp.). RMS-3 and RMS-5 values were higher in pregnancy but these differences were not statistically significant.Conclusion. Pregnancy increased photopic and mesopic pupil size significantly but did not increase wavefront aberrations notably. Increased pupil size may be due to increased sympathetic activity during pregnancy. And this activity can be noninvasively determined by measuring pupil size.
Parallel Aspects of the Microenvironment in Cancer and Autoimmune Disease
Authors: Rahat Michal A. , Shakya Jivan
Published: February 2016

Cancer and autoimmune diseases are fundamentally different pathological conditions. In cancer, the immune response is suppressed and unable to eradicate the transformed self-cells, while in autoimmune diseases it is hyperactivated against a self-antigen, leading to tissue injury. Yet, mechanistically, similarities in the triggering of the immune responses can be observed. In this review, we highlight some parallel aspects of the microenvironment in cancer and autoimmune diseases, especially hypoxia, and the role of macrophages, neutrophils, and their interaction. Macrophages, owing to their plastic mode of activation, can generate a pro- or antitumoral microenvironment. Similarly, in autoimmune diseases, macrophages tip the Th1/Th2 balance via various effector cytokines. The contribution of neutrophils, an additional plastic innate immune cell population, to the microenvironment and disease progression is recently gaining more prominence in both cancer and autoimmune diseases, as they can secrete cytokines, chemokines, and reactive oxygen species (ROS), as well as acquire an enhanced ability to produce neutrophil extracellular traps (NETs) that are now considered important initiators of autoimmune diseases. Understanding the contribution of macrophages and neutrophils to the cancerous or autoimmune microenvironment, as well as the role their interaction and cooperation play, may help identify new targets and improve therapeutic strategies.
Measuring Entropy Change in a Human Physiological System
Authors: Boregowda Satish , Handy Rod , Sleeth Darrah , Merryweather Andrew
Published: February 2016

The paper presents a novel approach involving the use of Maxwell relations to combine multiple physiological measures to provide a measure of entropy change. The physiological measures included blood pressure (BP), heart rate (HR), skin temperature (ST), electromyogram (EMG), and electrodermal response (EDR). The multiple time-series physiological data were collected from eight subjects in an experimental pilot study conducted at the Human Engineering Laboratory of NASA Langley Research Center. The methodology included data collection during a relaxation period of eighteen minutes followed by a sixty-minute cognitive task. Two types of entropy change were computed: (a) entropy change (ΔSBP) due to blood pressure, heart rate, and skin temperature and (b) entropy change (ΔSEMG) due to electromyogram, electrodermal response, and skin temperature. The results demonstrate that entropy change provides a valuable composite measure of individual physiological response to various stressors that could be valuable in the areas of medical research, diagnosis, and clinical practice.
Enhancement of Video Streaming in Distributed Hybrid Architecture
Authors: Kanrar Soumen , Mandal Niranjan Kumar
Published: February 2016

Pure Peer to Peer (P2P) network requires enhancing transportation of chunk video objects to the proxy server in the mesh network. The rapid growth of video on demand user brings congestion at the proxy server and on the overall network. The situation needs efficient content delivery procedure, to the video on demand viewer from the distributed storage. In general scenario, if the proxy server does not possess the required video stream or the chunk of that said video, then the same can be smoothly and rapidly streamed to the viewer. This paper has shown that multitier mesh shaped hybrid architecture composed of P2P and mesh architecture increase the number of requests served by the dynamic environment in comparison with the static environment. Optimized storage finding path search reduces the unnecessary query forward and hence increases the size of content delivery to the desired location.
A Soft Rough-Fuzzy Preference Set-Based Evaluation Method for High-Speed Train Operation Diagrams
Authors: Chen Dingjun , Ni Shaoquan , Xu Chang’an , Lv Hongxia , Qin Keyun
Published: February 2016

This paper proposes a method of high-speed railway train operation diagram evaluation based on preferences of locomotive operation, track maintenance, S & C, vehicles and other railway departments, and customer preferences. The application of rough set-based attribute reduction obtains the important relative indicators by eliminating excessive and redundant evaluation indicators. Soft fuzzy set theory is introduced for the overall evaluation of train operation diagrams. Each expert utilizes a set of indicators during evaluation based on personal preference. In addition, soft fuzzy set theory is applied to integrate the information obtained via expert evaluation in order to obtain an overall evaluation. The proposed method was validated by a case study. Results demonstrate that the proposed method flexibly expresses the subjective judgments of experts while effectively and reasonably handling the uncertainty of information, which is consistent with the judgment process of humans. The proposed method is also applicable to the evaluation of train operation schemes which consist of multiple diagrams.
Optic Disc Vascularization in Glaucoma: Value of Spectral-Domain Optical Coherence Tomography Angiography
Authors: Lévêque Pierre-Maxime , Zéboulon Pierre , Brasnu Emmanuelle , Baudouin Christophe , Labbé Antoine
Published: February 2016

Purpose. To detect changes in optic nerve head (ONH) vascularization in glaucoma patients using spectral-domain OCT angiography (OCT-A).Material and Method. Fifty glaucoma patients and 30 normal subjects were evaluated with OCT-A (AngioVue®, Optovue). The total ONH vessel density and temporal disc vessel density were measured. Clinical data, visual field (VF) parameters, and spectral-domain OCT evaluation (RNFL: retinal nerve fiber layer thickness, GCC: ganglion cell complex thickness, and rim area) were recorded for glaucoma patients. Correlations among total and temporal ONH vessel density and structural and VF parameters were analyzed.Results. In the glaucoma group, total and temporal ONH vessel density were reduced by 24.7% (0.412 versus 0.547;p<0.0001) and 22.88% (0.364 versus 0.472;p=0.001), respectively, as compared with the control group. Univariate analysis showed significant correlation between rim area (mm2) and temporal ONH vessel density (r=0.623;p<0.0001) and total ONH vessel density (r=0.609;p<0.0001). Significant correlations were found between temporal and total ONH vessel density and RNFL, GCC, VF mean deviation, and visual field index.Conclusion. In glaucoma patients OCT-A might detect reduced ONH blood vessel density that is associated with structural and functional glaucomatous damage. OCT-A might become a useful tool for the evaluation of ONH microcirculation changes in glaucoma.
Changes in the Physicochemical Properties of Piperine/β-Cyclodextrin due to the Formation of Inclusion Complexes
Authors: Ezawa Toshinari , Inoue Yutaka , Tunvichien Sujimon , Suzuki Rina , Kanamoto Ikuo
Published: February 2016

Piperine (PP) is a pungent component in black pepper that possesses useful biological activities; however it is practically insoluble in water. The aim of the current study was to prepare a coground mixture (GM) of PP and β-cyclodextrin (βCD) (molar ratio of PP/βCD = 1/1) and subsequently evaluate the solubility of PP and physicochemical properties of the GM. DSC thermal behavior of the GM showed the absence of melting peak of piperine. PXRD profile of the GM exhibited halo pattern and no characteristic peaks due to PP and βCD were observed. Based on Job’s plot, the PP/βCD complex in solution had a stoichiometric ratio of 1/1. Raman spectrum of the GM revealed scattering peaks assigned for the benzene ring (C=C), the methylene groups (CH2), and ether groups (C-O-C) of PP that were broaden and shifted to lower frequencies. SEM micrographs showed that particles in the GM were agglomerated and had rough surface, unlike pure PP and pure βCD particles. At 15 min of dissolution testing, the amount dissolved of PP in the GM was dramatically increased (about 16 times) compared to that of pure PP. Moreover the interaction between PP and βCD cavity was detected by 1H-1H NMR nuclear Overhauser effect spectroscopy NMR spectroscopy.
(∈,∈∨q)-FuzzyBCK-Submodules
Authors: Altaiary M. M. , Bashammakh S. A. , Alshehri N. O.
Published: February 2016

We introduce the concept of generalized fuzzy module ofBCK-algebras and present some fundamental properties. Also, we introduce the concept of generalized interval-valued fuzzyBCK-submodule and present some fundamental properties.
Risk Factors for Foot Amputation in Patients Hospitalized for Diabetic Foot Infection
Authors: Verrone Quilici Maria Teresa , Del Fiol Fernando de Sá , Franzin Vieira Alexandre Eduardo , Toledo Maria Inês
Published: February 2016

The aim of this study was to identify and quantify risk factors for amputation in diabetic patients hospitalized for foot infections. This cross-sectional study comprised 100 patients with diabetic infectious complications in the lower limbs. The variables investigated were related to diabetes, infection, and treatment compliance. Multiple Cox regression analysis was performed to identify the variables independently associated with the outcome of amputation. The most prevalent chronic complications were neuropathy and hypertension. Most patients presented with a neuroischemic foot (86%). The Morisky test showed that 72% were not compliant with diabetes treatment. Regarding patient outcome, 61% progressed to amputation, 14% to debridement, and 9% to revascularization. The results showed a 42% higher risk for progression to amputation in patients with previous use of antimicrobials. Also, the amputation risk was 26% higher for those less compliant with diabetes treatment. An increase of one point in the Wagner ulcer classification criteria corresponded to a 65% increase in the risk of amputation. Undergoing conservative, nonsurgical procedures prior to admission provided a 63% reduction in the risk of amputation. Knowledge of these factors is critical to enable multidisciplinary teams to develop treatment plans for these patients so as to prevent the need for amputation.