bluuebunny/crossref_metadata_2025 huggingface dataset:
Postexercise hypotension after maximal short-term incremental exercise depends on exercise modality
Authors: Cunha Felipe A. , Midgley Adrian W. , Soares Pedro P. , Farinatti Paulo T.V.
Published: February 2015

This study investigated postexercise hypotension (PEH) after maximal cardiopulmonary exercise testing (CPET) performed using different exercise modalities. Twenty healthy men (aged 23 ± 3 years) performed 3 maximal CPETs (cycling, walking, and running), separated by 72 h in a randomized, counter-balanced order. Systolic (SBP) and diastolic blood pressure (DBP), heart rate, cardiac output, systemic vascular resistance (SVR), autonomic function (spontaneous baroreflex sensitivity (BRS) and heart rate variability (HRV)), and energy expenditure (EE) were assessed during a 60-min nonexercise control session and for 60 min immediately after each CPET. Total exercise volume (EE during CPET plus 60 min recovery) was significantly higher in running versus cycling and walking CPETs (P ≤ 0.001). Compared with control, only SBP after running CPET was significantly reduced (Δ = −6 ± 8 mm Hg; P < 0.001). Heart rate and cardiac output were significantly increased (P < 0.001) and SVR significantly decreased (P < 0.001) postexercise. BRS and HRV decreased after all CPETs (P < 0.001), whereas sympatho-vagal balance (low- and high-frequency (LF:HF) ratio) increased significantly after all exercise conditions, especially after running CPET (P < 0.001). Changes in SVR, BRS, sympathetic activity (low-frequency component of HRV), and LF:HF ratio were negatively correlated to variations in SBP (range −0.69 to −0.91; P < 0.001) and DBP (range −0.58 to −0.93; P ≤ 0.002). These findings suggest that exercise mode or the total exercise volume are major determinants of PEH magnitude in healthy men. Because of the running CPET, the PEH was primarily related to a decrease in SVR and to an increase in sympatho-vagal balance, which might be a reflex response to peripheral vasodilatation after exercise.
Addendum to “Managing wolves (Canis lupus) to recover threatened woodland caribou (Rangifer tarandus caribou) in Alberta”
Authors: Hervieux Dave , Hebblewhite Mark , Stepnisky Dave , Bacon Michelle , Boutin Stan
Published: February 2015

Managing predators to restore threatened or endangered species is often controversial. Hervieux et al. (2014; Can. J. Zool. 92(12): 1029–1037) report on the efficacy of wolf (Canis lupus L., 1758) reduction as a recovery strategy in the Little Smoky population of boreal woodland caribou (Rangifer tarandus caribou (Gmelin, 1788)) range in Alberta, which generated a lot of media attention. As such, the authors were invited by the journal editor who handled the original paper to write this addendum to provide clarification regarding the methodology used in the original paper. Wolf reduction was conducted by Government personnel in accordance with appropriate policy and laws (i.e., federal and provincial Species at Risk Acts; Alberta Wildlife Act; Alberta Woodland Caribou Policy). University-based researchers were involved only in data analysis and writing, and thus did not require approval by a university-based animal welfare board. Collaboration between independent university-based scientists and government biologists is essential to effective assessment of such controversial management practices. Hervieux et al. (2014; Can. J. Zool. 92(12): 1029–1037) in fact concluded that such wolf reductions, by themselves, would only “buy time” and would not restore woodland caribou alone without effective habitat protection.
A study of different horizons in inhomogeneous LTB cosmological model
Authors: Chakraborty Subenoy , Saha Subhajit
Published: February 2015

This work deals with a detailed study of the dynamics of the apparent, event and particle horizons in the background of the inhomogeneous LTB spacetime. The comparative study among these horizons shows a distinct character for apparent horizon compared to the other horizons. The apparent horizon will be a trapping horizon if its acceleration is positive. The Kodama vector is also defined and its causal character is found to be similar to that in the FRW model.
Higgs model coupled to dark photons
Authors: Carcamo D. , Gamboa J. , Pino M.
Published: February 2015

A dark sector containing a Higgs field and a dark photon coupled to visible photons via a small kinetic mixing is considered. The mass of the dark gauge boson becomes rescaled by the parameter involved in the kinetic mixing. We also calculate the total annihilation cross-section for scalar Higgs interacting with an external field and show that exhibits Sommerfeld enhancement. The model can be extended to a SU(3) × SU(2) × U(1) dark sector. The mass of the dark Z boson increases due to the kinetic mixing.
Charge separation in supramolecular ferrocene(s)-zinc porphyrin-fullerene triads: A femtosecond transient absorption study
Authors: Lim Gary N. , Webre Whitney A. , D'Souza Francis
Published: February 2015

Mechanistic aspects of photoinduced charge separation in supramolecular triads, constructed using covalently linked zinc porphyrin-ferrocene(s) dyads — self-assembled via axial coordination to either pyridine or phenylimidazole appended fulleropyrrolidine ( Fc x- ZnP : PyC 60 or Fc x- ZnP : ImC 60; x = 1 or 2), has been investigated using femtosecond pump-probe transient spectroscopy. Upon photoexcitation of ZnP , charge separation from ferrocene to 1 ZnP * to yield the initial Fc +- ZnP •-: C 60 radical ion-pair or charge separation from 1 ZnP * to C 60 to yield the initial Fc - ZnP •+: C 60•- radical ion-pair, depending upon the ferrocene-zinc porphyrin intermolecular distance, was observed. These radical ion-pairs resulted in the formation of ultimate distantly separated Fc +- ZnP : C 60•- radical ion-pairs either via an electron migration (former case) or hole shift (latter case) process. Kinetics of charge separation as a function of spacer connecting the ferrocene and porphyrin, and spacer between the porphyrin and fullerene is reported. In agreement with our earlier study (J. Phys. Chem. B 2004; 108: 11333–11343), the Fc +- ZnP : C 60•- radical ion-pair persisted beyond the monitoring time window of our instrument, suggesting charge stabilization in these supramolecular triads.
A Semantic++ MapReduce Parallel Programming Model
Authors: Zhang Guigang , Li Chao , Zhang Yong , Xing Chunxiao
Published: February 2015

Big data is playing a more and more important role in every area such as medical health, internet finance, culture and education etc. How to process these big data efficiently is a huge challenge. MapReduce is a good parallel programming language to process big data. However, it has lots of shortcomings. For example, it cannot process complex computing. It cannot suit real-time computing. In order to overcome these shortcomings of MapReduce and its variants, in this paper, we propose a Semantic++ MapReduce parallel programming model. This study includes the following parts. (1) Semantic++ MapReduce parallel programming model. It includes physical framework of semantic++ MapReduce parallel programming model and logic framework of semantic++ MapReduce parallel programming model; (2) Semantic++ extraction and management method for big data; (3) Semantic++ MapReduce parallel programming computing framework. It includes semantic++ map, semantic++ reduce and semantic++ shuffle; (4) Semantic++ MapReduce for multi-data centers. It includes basic framework of semantic++ MapReduce for multi-data centers and semantic++ MapReduce application framework for multi-data centers; (5) A Case Study of semantic++ MapReduce across multi-data centers.
Natural Language Generation from Graphs
Authors: Dong Ngan T. , Holder Lawrence B.
Published: February 2015

The Resource Description Framework (RDF) is the primary language to describe information on the Semantic Web. The deployment of semantic web search from Google and Microsoft, the Linked Open Data Community project along with the announcement of schema.org by Yahoo, Bing and Google have significantly fostered the generation of data available in RDF format. Yet the RDF is a computer representation of data and thus is hard for the non-expert user to understand. We propose a Natural Language Generation (NLG) engine to generate English text from a small RDF graph. The Natural Language Generation from Graphs (NLGG) system uses an ontology skeleton, which contains hierarchies of concepts, relationships and attributes, along with handcrafted template information as the knowledge base. We performed two experiments to evaluate NLGG. First, NLGG is tested with RDF graphs extracted from four ontologies in different domains. A Simple Verbalizer is used to compare the results. NLGG consistently outperforms the Simple Verbalizer in all the test cases. In the second experiment, we compare the effort spent to make NLGG and NaturalOWL work with the M-PIRO ontology. Results show that NLGG generates acceptable text with much smaller effort.
Ion Colliders
Authors: Fischer Wolfram , Jowett John M.
Published: February 2015

High energy ion colliders are large research tools in nuclear physics for studying the quark–gluon–plasma (QGP). The collision energy and high luminosity are important design and operational considerations. The experiments also expect flexibility with frequent changes in the collision energy, detector fields, and ion species. Ion species range from protons, including polarized protons in RHIC, to heavy nuclei like gold, lead, and uranium. Asymmetric collision combinations (such as protons against heavy ions) are also essential. For the creation, acceleration, and storage of bright intense ion beams, limits are set by space charge, charge change, and intrabeam scattering effects, as well as beam losses due to a variety of other phenomena. Currently, there are two operating ion colliders: the Relativistic Heavy Ion Collider (RHIC) at BNL and the Large Hadron Collider (LHC) at CERN.
Electron–Proton and Electron–Ion Colliders
Authors: Ben-Zvi Ilan , Ptitsyn Vadim
Published: February 2015

The physics motivation, accelerator science, plans for future facilities and major accelerator systems of electron–ion colliders are presented. The science enabled by these machines motivates the machine design with high luminosity and flexibility, and thus leads to new challenges in accelerator science. Innovative solutions, developed in order to achieve the objectives set for these machines, are described. Major accelerator systems and accelerator physics issues are also described, and references are provided for readers interested in greater detail.
Collider Beam Physics
Authors: Zimmermann Frank
Published: February 2015

I review some accelerator physics topics for circular as well as linear colliders, considering both lepton and hadron beams.
Collision Technologies for Circular Colliders
Authors: Levichev Eugene
Published: February 2015

For several decades already, particle colliders have been essential tools for particle physics. From the very beginning, such accelerators have been among the most complicated scientific instruments ever built, including a number of innovative technological developments. Examples are ultrahigh vacuum systems, magnets with a very high magnetic field, and equipment for sub-ns synchronization and sub-mm precision alignment of equipment inside multi-km underground tunnels. Some key technologies are related to the focusing of the beam down to a scale of sub-μm at the collision point to obtain high luminosity. This review provides an overview of collision concepts and technologies for circular particle colliders, starting from the first ideas. In particular, it discusses such novel schemes and related technologies as crab waist collision and round beam collision.
Chemostratigraphy and magnetic susceptibility of the Late Devonian Frasnian–Famennian transition in western Canada and southern China: implications for carbon and nutrient cycling and mass extinction
Authors: Whalen Michael T. , Śliwiński Maciej G. , Payne Joshua H. , Day James E. , Chen Daizhao , Da Silva Anne-Christine
Published: February 2015

We investigate the Late Devonian Frasnian–Famennian extinction interval in western Alberta and south China to shed light on the palaeoecological and palaeoceanographic conditions that characterize this biotic crisis. Both the Lower and Upper Kellwasser events are documented in western Canada. Only the Upper Kellwasser event has been evaluated in south China. Our multiproxy geochemical approach reveals that these events are characterized by positive δ
13
C and δ
15
N excursions and increasing magnetic susceptibility (Canada/China) and increases in detrital (Al, Si, Ti, Zr), productivity (Cu, Ni, Zn) and redox (Mo, U, V) elemental proxies (Canada). We interpret these trends as part of a systemic palaeoecological shift associated with the development of widespread terrestrial forests and their alteration of chemical–mechanical weathering patterns. Increase in detrital proxies is thus interpreted as resulting from pedogenically driven weathering on the continents that nutrified epeiric and continental margin seas. High biological productivity led to eutrophication and development of suboxic to anoxic conditions during both events and probably euxinic conditions during the Upper Kellwasser event in western Canada. Positive δ
13
C excursions are the telltale signature of excessive carbon burial, while redox proxies and δ
15
N records indicate suboxic–anoxic denitrifying conditions.
The role of local societies in early modern geotourism: a case study of the Chester Society of Natural Science and the Woolhope Naturalists’ Field Club
Authors: Burek Cynthia V. , Hose Thomas A.
Published: February 2015

Local voluntary natural science societies played an important role in the development of early modern geotourism. This chapter explores the development of field, especially geological, excursions and their popularity in two local natural science societies – The Chester Society of Natural Science and the Woolhope Naturalists’ Field Club – from the 1850s to the 1950s. Both societies were established in the borderlands between England and Wales and had a strong emphasis on local and regional scientific studies. They exemplify broader trends in public engagement in the natural sciences and associated fieldwork consequent upon the British socio-political environment. Further, they draw out comparisons between the attitudes of society to excursions and scientific fieldwork, as well as involvement by social status and gender.
FSAIPACK
Authors: Janna Carlo , Ferronato Massimiliano , Sartoretto Flavio , Gambolati Giuseppe
Published: February 2015

The Factorized Sparse Approximate Inverse (FSAI) is an efficient technique for preconditioning parallel solvers of symmetric positive definite sparse linear systems. The key factor controlling FSAI efficiency is the identification of an appropriate nonzero pattern. Currently, several strategies have been proposed for building such a nonzero pattern, using both static and dynamic techniques. This article describes a fresh software package, called FSAIPACK, which we developed for shared memory parallel machines. It collects all available algorithms for computing FSAI preconditioners. FSAIPACK allows for combining different techniques according to any specified strategy, hence enabling the user to thoroughly exploit the potential of each preconditioner, in solving any peculiar problem. FSAIPACK is freely available as a compiled library at http://www.dmsa.unipd.it/~janna/software.html, together with an open-source command language interpreter. By writing a command ASCII file, one can easily perform and test any given strategy for building an FSAI preconditioner. Numerical experiments are discussed in order to highlight the FSAIPACK features and evaluate its computational performance.
Solving Basis Pursuit
Authors: Lorenz Dirk A. , Pfetsch Marc E. , Tillmann Andreas M.
Published: February 2015

The problem of finding a minimum ℓ
1
-norm solution to an underdetermined linear system is an important problem in compressed sensing, where it is also known as
basis pursuit
. We propose a heuristic optimality check as a general tool for ℓ
1
-minimization, which often allows for early termination by “guessing” a primal-dual optimal pair based on an approximate support. Moreover, we provide an extensive numerical comparison of various state-of-the-art ℓ
1
-solvers that have been proposed during the last decade, on a large test set with a variety of explicitly given matrices and several right-hand sides per matrix reflecting different levels of solution difficulty. The results, as well as improvements by the proposed heuristic optimality check, are analyzed in detail to provide an answer to the question which algorithm is the best.
DAESA—A Matlab Tool for Structural Analysis of Differential-Algebraic Equations
Authors: Pryce John D. , Nedialkov Nedialko S. , Tan Guangning
Published: February 2015

daesa
, Differential-Algebraic Equations Structural Analyzer, is a M
atlab
tool for structural analysis of differential-algebraic equations (DAEs). It allows convenient translation of a DAE system into M
atlab
and provides a small set of easy-to-use functions.
daesa
can analyze systems that are fully nonlinear, high-index, and of any order. It determines structural index, number of degrees of freedom, constraints, variables to be initialized, and suggests a solution scheme. The structure of a DAE can be readily visualized by this tool. It also can construct a block-triangular form of the DAE, which can be exploited to solve it efficiently in a block-wise manner.

This article describes the theory and algorithms underlying the code.
Software Architecture Patterns: Reflection and Advances
Authors: Harrison Neil B. , van Heesch Uwe , Sobernig Stefan , Sommerlad Peter , Filipczyk Martin , Fülleborn Alexander , Musil Angelika , Musil Juergen
Published: February 2015

Architectural software patterns capture successful designs for recurring problems in software architecture. For the first time, a workshop in the tradition of the software-pattern conference series (e.g. PLoP, EuroPLoP) was held jointly with the European Conference on Software Architecture (ECSA 2014) in Vienna, Austria. The main objective of this workshop called MiniPLoP was to bring software architecture researchers closer to the pattern community and to introduce the writers' workshop format to them. Writers' workshop at PLoP conferences provide authors of pattern papers with high-density feedback given by peers within a limited timeframe. In addition, our workshop provided a forum to reect on the state of software architecture patterns and to discuss advances pattern research. This report contains an extended keynote abstract and summaries of the papers discussed during the workshop.
Improving Software Quality and Productivity Leveraging Mining Techniques
Authors: Li Ming , Zhang Hongyu , Lo David , Lucia
Published: February 2015

The second International Workshop on Software Mining (Soft-mine) was held on the 11th of November 2013. The workshop was held in conjunction with the 28th IEEE/ACM International Conference on Automated Software Engineering (ASE) in Silicon Valley, California, USA. The workshop has facilitated researchers who are interested in mining various types of software-related data and in applying data mining techniques to support software engineering tasks. During the workshop, seven papers on software mining and behavior models, execution trace mining, and bug localization and fixing were presented. One of the papers received the best paper award. Furthermore, there were two invited talk sessions presented by two active researchers from software engineering and data mining community.
Interaction Traces Mining for Efficient System Responses Generation
Authors: Du Miao , Versteeg Steve , Schneider Jean-Guy , Han Jun , Grundy John
Published: February 2015

Software service emulation is an emerging technique for creating realistic executable models of server-side behaviour. It is particularly useful in quality assurance and DevOps, replicating production-like conditions for large-scale enterprise software systems. Existing approaches can automatically build client-server and server-server interaction models of complex software systems directly from analysis of service interaction trace data. However, when these interaction traces become large, searching an entire trace library to generate a run-time responses can become very slow. In this paper we describe a new technique that utilises data mining, specifically clustering algorithms, to pre-process large amounts of recorded interaction trace data. With the obtained clusters we facilitate efficient yet well-formed runtime response generation in our Enterprise System emulation environment. We evaluate our approach using two common application-layer protocols: LDAP and SOAP. Our experimental results show that by utilising clustering techniques in the pre-processing step, the response generation time can be reduced by 99% on average compared with existing approaches.
On Incomplete Bug Fixes in Eclipse and Programmers' Intuition on These
Authors: Agbaria Sabih , Gil Joseph (Yossi)
Published: February 2015

Recent studies indicate that multiple patches to software are found in a hefty portion of resolved bugs. It is also known that bugs that require multiple patches take longer to resolve, that their severity tends to be higher than the average and that they induce programmers to engage more in bug discussions. This work is concerned with the ability of programmers to predict a bug will be of this sort, and in particular that it may require future patches and greater refixing effort at the time the bug is fixed at the first time. A mathematical model is developed for a retrospective analysis of bugs maintenance history. In this model we compute the impact of an array of bug properties on the likelihood that a specific bug is chosen, among all open bugs, to receive its first fix. The studies we conduct on a sizable portion of the history of the Eclipse code base indicate that programmers tend to attend first to bugs which are easier to fix. The results further suggest that some of the criteria that programmers apply (probably unknowingly) to determine whether a bug is easy to fix, is the number of future patches it would require, and the amount of work involved in these patches. This is despite the fact that this information is not supposed to be available to the programmers at the time the first fix is made. It is anticipated that the method of analysis introduced in this work would have other applications in software engineering, but also outside of computer science.
A Measures and Metrics Framework for Software Safety
Authors: Acharyulu P.V. Srinivas , Seetharamaiah P.
Published: February 2015

A set of software-safety metrics is presented in this paper. The proposed metrics framework is intended to address software-safety risk assessment and can be used to evaluate the software-safety quality of a process. The framework attempts to assess safety risks from the beginning of the software development lifecycle and helps to implement efficient solutions. The complete framework is based on McCall's Factors, Criteria and Metrics approach and useful for assessing the degree of safety risk prevalence. The objective is to identify software elements that can lead to accidents if not properly addressed with the support of the safety engineering and software engineering disciplines. Various safety analysis methods including hazard analysis, standards, and guidelines are reviewed for their limitations and practical problems are considered. The framework considers measures that contribute to safety assessment through metrics in each of the Software Development Life Cycle phase. An experimental laboratory setup as 'Safety-Critical System' called Railroad Crossing Critical System (RCCS), which implements a safety-critical software, is used for demonstration and to validate the utility of the framework.
Software Architecture Recovery using Genetic Black Hole Algorithm
Authors: Jeet Kawal , Dhir Renu
Published: February 2015

Software clustering is a technique that is used to manage a software system by partitioning it into smaller subsystems containing highly related modules. Search-based software clustering techniques are found to be beneficial in effective partitioning of software systems. In this paper, we propose a search-based technique that is based on a combination of a nature-inspired black-hole algorithm and a genetic algorithm for software clustering. In order to evaluate the success of this approach, it has been applied to some real-world software systems. It is observed that this approach deduces a structure similar to the original architecture of the software system concerned.
A Proactive Procedure to Mitigate the BYOD Risks on the Security of an Information System
Authors: Kumar Rakesh , Singh Hardeep
Published: February 2015

During the last ten years, security attacks on information systems have led to a huge number of data breaches all over the globe. Information security risks are causing massive damage to organizations. The security risk could be costlier to handle if not given due attention. We need to build a security culture in which everyone can recognize and evaluate the risks. In the current scenario the risks due to BYOD have emerged as a new challenge to information-security practitioners. The present study focuses on evaluating BYOD risks and their causes well before they become a threat to an organization. A new procedure is proposed to tackle the threats from BYOD and an empirical analysis is provided for validation of the proposed procedure.
Use of Semi-Formal and Formal Methods in Requirement Engineering of ILMS
Authors: Sengupta Souvik , Dasgupta Ranjan
Published: February 2015

A systematic approach in requirement engineering helps in discovering and understanding the requirements at different levels of abstraction as well as makes the requirements traceable and verifiable early in the project. This paper presents a methodology for requirement engineering by using a combination of formal and semiformal techniques to model software requirements for analysis and verification. The proposed framework incorporates requirement-analysis and requirement-verification models, which are guided by the Domain Model represented by a Conceptual Class diagram and the defined Ontology. The proposed approach is particularly useful when requirements are defined in hierarchical levels of abstraction and traceability between a requirement at a detailed level and its correspondence at an abstract level is required. The proposed framework also allows verification of the accordance of the requirements with respect to the Domain Model. The requirement analysis model at each level of abstraction is represented by a combination of three different modeling techniques: Conceptual Graph, Use-Case diagram and VDM-SL specification. A verification model to ensure traceability between the requirements at different abstraction levels, using a three-dimensional schema, is also proposed. The Requirements of an Intelligent Learning Management System are used as an example to illustrate the proposal.
From Test Purposes to Formal JPF Properties
Authors: Hanazumi Simone , de Melo Ana C.V. , Păsăreanu Corina S.
Published: February 2015

Software quality is traditionally achieved by applying testing techniques and/or formal verification to the system under development. Formal testing techniques have been defined to assure the software quality based on a set of test purposes the users want to observe on the system under testing (SUT). This paper proposes the use of Java PathFinder (JPF) to observe test purposes, defined as properties, over the whole program behavior. To make this approach available to test community, a user-friendly interface to define test purposes as properties is provided, together with a JPF extension to observe the test purposes. To define a property, the user only needs to select a property pattern, its scope, and the events of interest. Then, a finite-state automaton is generated and can be submitted to JPF to verify the defined property. As a result, JPF provides a report including a property verdict (pass/fail), and the program traces and percentage of the traversed automaton during the verification process. This coverage information can be used to analyze the performed verification and guide a complementary test suite generation.
Symbolic Execution for Checking the Accuracy of Floating-Point Programs
Authors: Ramachandran Jaideep , Păsăreanu Corina , Wahl Thomas
Published: February 2015

Programs with oating-point calculations tend to give rise to hard-to-predict behavior. Such uncertainty cannot be ignored: oating-point errors can have catastrophic consequences, as it happened with the Patriot missile accident in 1991. The likelihood of such incidents can be decreased by using automated technology to reliably analyze numerical code. We present a symbolic execution approach to checking the accuracy of numerical programs, investigating how much a oating-point computation deviates from the "ideal" computation on real values. Our method is implemented in the Symbolic PathFinder tool and leverages and extends the floating-point decision procedure Realizer to check symbolic path constraints and to perform the accuracy checks. We further illustrate the possibility of using our tools to enhance abstract interpretation-based analyses to obtain tighter bounds on the numerical error introduced by oating-point computations. Initial experiments show the promise of our approach.
Improving Coverage of Test Cases Generated by Symbolic PathFinder for Programs with Loops
Authors: Kersten Rody , Person Suzette , Rungta Neha , Tkachuk Oksana
Published: February 2015

Symbolic execution is a program analysis technique that is used for many purposes, one of which is test case generation. For loop-free programs, this generates a test set that achieves path coverage. Program loops, however, imply exponential growth of the number of paths in the best case and non-termination in the worst case. In practice, the number of loop unwindings needs to be bounded for analysis.

We consider symbolic execution in the context of the tool Symbolic Pathfinder. This tool extends the Java Pathfinder model-checker and relies on its bounded state-space exploration for termination. We present an implementation of k-bounded loop un- winding, which increases the amount of user-control over the symbolic execution of loops.

Bounded unwinding can be viewed as a naive way to prune paths through loops. When using symbolic execution for test case generation, branch coverage will likely be lost when paths are naively pruned. In order to improve coverage of branches within a loop body, we present a technique that semi-automatically concretizes variables used in a loop. The basic technique is limited and we therefore present annotations to manually steer symbolic execution towards certain branches, as well as ideas on how the technique can be extended to be more widely applicable.
A Report on Software Engineering Education Workshop (SEEW) 2014 Co-Located with Asia-Pacific Software Engineering Conference 2014
Authors: Sureka Ashish , Reddy Y. Raghu , Muenchaisri Pornsiri , Tsunoda Masateru
Published: February 2015

The Software Engineering Education Workshop (SEEW) 2014 was held on 1st December 2014 at Jeju (South Korea). The worksho was co-located with The 21st Asia-Pacific Software Engineering Conference (APSEC 2014). The objective of SEEW is to create an annual discussion forum on Software Engineering (SE) Education in the Asia-Pacific region. The workshop was organized by experienced Software Engineering educators (working in Academia and Industry) from three different countries in the Asia-Pacific region: India, Japan, and Thailand. The total number of participants were 18 spread across 7 countries. The workshop consisted of 7 position paper presentations consisting of a wide range of topics and research questions. The paper presentation was followed by a group discussion which resulted in identifying important aspects and future research directions on Software Engineering Education. The workshop was a successful endeavor and the response in terms of the contributions by participants is a clear indicator and confirmation of the need of having a focused discussion forum for brainstorming on software engineering education in Asia-Pacific region.
Robust Color Image Watermarking Using Geometric Invariant Quaternion Polar Harmonic Transform
Authors: Yang Hong-Ying , Wang Xiang-Yang , Niu Pan-Pan , Wang Ai-Long
Published: February 2015

It is a challenging work to design a robust color image watermarking scheme against geometric distortions. Moments and moment invariants have become a powerful tool in robust image watermarking owing to their image description capability and geometric invariance property. However, the existing moment-based watermarking schemes were mainly designed for gray images but not for color images, and detection quality and robustness will be lowered when watermark is directly embedded into the luminance component or three color channels of color images. Furthermore, the imperceptibility of the embedded watermark is not well guaranteed. Based on algebra of quaternions and polar harmonic transform (PHT), we introduced the quaternion polar harmonic transform (QPHT) for invariant color image watermarking in this article, which can be seen as the generalization of PHT for gray-level images. It is shown that the QPHT can be obtained from the PHT of each color channel. We derived and analyzed the rotation, scaling, and translation (RST) invariant property of QPHT. We also discussed the problem of color image watermarking using QPHT. Experimental results are provided to illustrate the efficiency of the proposed color image watermarking against geometric distortions and common image processing operations (including color attacks).
EngageCSEdu
Authors: Monge Alvaro E. , Fadjo Cameron L. , Quinn Beth A. , Barker Lecia J.
Published: February 2015

While the number of students interested in computer science is rising, the percentage of women and underrepresented minorities remains low. Many things influence whether a student will pursue a degree in computer science, but having a great experience in introductory courses is essential. The National Center for Women & Information Technology (NCWIT) has partnered with Google to create EngageCSEdu, a comprehensive and growing collection of instructional materials and pedagogical strategies for engaging and retaining undergraduate students in introductory computing courses. This article introduces the key features of EngageCSEdu and the peer-reviewed system for creating and growing the collection.
Algorithm Differentiation in Lisp
Authors: Fateman Richard
Published: February 2015

Algorithm differentiation (AD) is a technique used to transform a program F computing a numerical function of one argument F(x) into another program G(p) that returns a pair, hF(p), F0(p)i where by F0(p) we mean the derivative of F with respect to its argument x, evaluated at x = p. That is, we have a program AD that takes as input a program, and returns another: G := AD(F). Over the years AD programs have been developed to allow F to be expressed in some specialized variant of a popular programming language L (FORTRAN, C, Matlab, Python) and where G is delivered in that language L or some other. Alternatively, executing F(p) is some environment will deliver hF0(p), F(p)i directly. AD tools have also been incorporated in computer algebra systems (CAS) such as Maple. A CAS is hardly necessary for the task of writing the AD program, since the main requirement is a set of tools for manipulation of an internal (typically tree) form of a program. In Lisp, a normal program is already in this form and so the AD program in Lisp (ADIL), the target F and the product G can all be expressed compactly in Lisp. In spite of the brevity and extensibility of the ADIL program, we can provide features which are unsupported in other AD programs. In particular, recursive functions are easily accommodated. Our perspective here is to point out that for scientists who write programs in Lisp or any language that can be converted to Lisp, AD is easily at hand.
Detecting Nonexistence of Rational Solutions of Linear Difference Equations in Early Stages of Computation
Authors: Gheffar Amal
Published: February 2015

We discuss some changes of the traditional scheme for finding rational solutions of linear difference equations (homogeneous or inhomogeneous) with rational coefficients. These changes in some cases allow one to detect the absence of rational solutions in an early stage of computation and to stop the work. The corresponding strategy may be useful for the algorithms based on finding rational solutions of equations of considered form, e.g., for some symbolic summation algorithms.
A Truncated Fourier Transform middle product
Authors: Arnold Andrew , Schost Éric
Published: February 2015

The middle product computes the middle
n
terms of a (2
n
--1)xn polynomial product, with effectively the same cost as computing an
n
x
n
polynomial product. The middle product allows for faster power series operations and Newton iteration. Middle product variants of classical, Karatsuba, and FFT-based multiplication algorithms are known. We present a middle product algorithm based on the Truncated Fourier Transform.
A Comparison of Three Heuristics to Choose the Variable Ordering for Cylindrical Algebraic Decomposition
Authors: Huang Zongyan , England Matthew , Wilson David , Davenport James H. , Paulson Lawrence C.
Published: February 2015

Cylindrical algebraic decomposition (CAD) is a key tool for problems in real algebraic geometry and beyond. When using CAD there is often a choice over the variable ordering to use, with some problems infeasible in one ordering but simple in another. Here we discuss a recent experiment comparing three heuristics for making this choice on thousands of examples.
Quantum Fourier Transform over Symmetric Groups
Authors: Kawano Yasuhito , Sekigawa Hiroshi
Published: February 2015

This paper improves the main result in our paper "Quantum Fourier Transform over Symmetric Groups, Proceedings of the International Symposium on Symbolic and Algebraic Computation (ISSAC), pp. 227--234, Northeastern University, Boston, USA (June 26-29, 2013)." In that paper, we presented an O(n4) quantum Fourier transform (QFT) algorithm over symmetric group Sn, which was faster than the existing algorithm. This paper proposes an O(n3 log n) QFT algorithm over Sn by relieving bottlenecks of our previous algorithm.
Fraction-Free Factoring Revisited
Authors: Middeke Johannes , Jeffrey David J.
Published: February 2015

We revisit fraction-free Gaussian elimination as a method for finding exact solutions of linear systems over integral domains, specifically integers and univariate polynomials. We conducted several experiments regarding common folklore about these methods such as pivoting strategies. Moreover, we find that the classical algorithms produce a unsettlingly high amount of common factors in the rows of the resulting matrices which they seem unable to detect let alone remove. We present preliminary results on remedying this fact. Finally, we apply fraction-free elimination to compute matrix inverses and to solve linear systems, and compare that to the use of fractional methods.
Calculation of Rational Numbers in an Interval Whose Denominator is the Smallest by using FP Interval Arithmetic
Authors: Murakami Hiroshi
Published: February 2015

The continued fraction expansion method is a fast solver to find a rational number in a given real interval whose denominator is the smallest. A simple implementation of the CF expansion method which uses floating point numbers as real numbers has a possibility to give a wrong answer by the effect of numerical round-off errors. In this paper, we show a modification of the algorithm of the CF expansion method so that it uses floating point (FP) intervals as replacements of real numbers. By this modified algorithm, the answer is obtained only when its correctness is guaranteed and the possibility to give a wrong answer is eliminated.
The Design of Maple's Sum-of-Products and POLY Data Structures for Representing Mathematical Objects
Authors: Monagan Michael , Pearce Roman
Published: February 2015

The principal data structure Maple uses to represent polynomials and general mathematical expressions involving functions like sin

x, e
2x
, y'(x),(n/k)

etc., is known to the Maple developers as the sum-of-products data structure. Gaston Gonnet, as the primary author of the Maple kernel, designed and implemented this data structure in the early 1980s. As part of the process of simplifying a mathematical formula, he represented every Maple object and every sub-object uniquely in memory. This makes testing for equality of expressions very fast. In this article, on occasion of Gonnet's retirement, we present details of his design, its pros and cons, and changes we and others have made to it over the years. One of the cons of the sum-of-products data structure is it is not as efficient at multiplying multivariate polynomials as other special purpose computer algebra systems. We describe a new data structure called POLY that we added to Maple 17 (released in 2013) to improve performance for polynomials in Maple, and recent work done for Maple 18 (released in 2014).
Basic Polynomial Algebra Subprograms
Authors: Chen Changbo , Covanov Svyatoslav , Mansouri Farnam , Maza Marc Moreno , Xie Ning , Xie Yuzhen
Published: February 2015

The Basic Polynomial Algebra Subprograms (BPAS) provides arithmetic operations (multiplication, division, root isolation, etc.) for univariate and multivariate polynomials over prime fields or with integer coefficients. The code is mainly written in CilkPlus [11] targeting multicore processors. The current distribution focuses on dense polynomials and the sparse case is work in progress. A strong emphasis is to put on adaptive algorithms as the library aims at supporting a wide variety of situations in terms of problem sizes and available computing resources. One of the purposes of the BPAS project is to take advantage of hardware accelerators in the development of polynomial systems solvers. The BPAS library is publicly available in source at www.bpaslib.org.
Diverse Stomatal Signaling and the Signal Integration Mechanism
Authors: Murata Yoshiyuki , Mori Izumi C. , Munemasa Shintaro
Published: February 2015

Guard cells perceive a variety of chemicals produced metabolically in response to abiotic and biotic stresses, integrate the signals into reactive oxygen species and calcium signatures, and convert these signatures into stomatal movements by regulating turgor pressure. Guard cell behaviors in response to such complex signals are critical for plant growth and sustenance in stressful, ever-changing environments. The key open question is how guard cells achieve the signal integration to optimize stomatal aperture. Abscisic acid is responsible for stomatal closure in plants in response to drought, and its signal transduction has been well studied. Other plant hormones and low-molecular-weight compounds function as inducers of stomatal closure and mediators of signaling in guard cells. In this review, we summarize recent advances in research on the diverse stomatal signaling pathways, with specific emphasis on signal integration and signal interaction in guard cell movement.
Knowledge-Based Hierarchies: Using Organizations to Understand the Economy
Authors: Garicano Luis , Rossi-Hansberg Esteban
Published: February 2015

Incorporating the decision of how to organize the acquisition, use, and communication of knowledge into economic models is essential to understand a wide variety of economic phenomena. We survey the literature that has used knowledge-based hierarchies to study issues such as the evolution of wage inequality, the growth and productivity of firms, economic development, and the gains from international trade, as well as offshoring and the formation of international production teams. We also review the nascent empirical literature that has, so far, confirmed the importance of organizational decisions and many of their more salient implications.
An Amazing Journey
Authors: McKay Larry
Published: February 2015

This article describes my early life and the chance events leading to my becoming a microbiologist and then my embarking on a career developing the plasmid biology and genetics of lactococci used in milk fermentations.
Stress Adaptation in Foodborne Pathogens
Authors: Begley Máire , Hill Colin
Published: February 2015

Foodborne bacterial pathogens encounter many environmental insults or stresses during food production, processing, storage, distribution, and preparation. However, these pathogens can sense changes in their surroundings and can respond by altering gene expression. A protective response may follow that increases tolerance to one or more stresses. This phenomenon is referred to as stress adaptation and has been shown to aid in the survival of pathogens in food products and in the food processing environment. Furthermore, stress adaptation may alter the virulence properties of pathogens and can contribute to survival in vivo during infection. Elucidating the molecular mechanisms underlying stress adaptation in bacterial food pathogens is essential for the development and implementation of more effective control measures and will permit the design of optimal processing regimes that combine maximum safety with consumer demands for more fresh-like, minimally processed foods.
Early Events of DNA Photodamage
Authors: Schreier Wolfgang J. , Gilch Peter , Zinth Wolfgang
Published: February 2015

Ultraviolet (UV) radiation is a leading external hazard to the integrity of DNA. Exposure to UV radiation triggers a cascade of chemical reactions, and many molecular products (photolesions) have been isolated that are potentially dangerous for the cellular system. The early steps that take place after UV absorption by DNA have been studied by ultrafast spectroscopy. The review focuses on the evolution of excited electronic states, the formation of photolesions, and processes suppressing their formation. Emphasis is placed on lesions involving two thymine bases, such as the cyclobutane pyrimidine dimer, the (6-4) lesion, and its Dewar valence isomer.
Sodium Channel β Subunits: Emerging Targets in Channelopathies
Authors: O'Malley Heather A. , Isom Lori L.
Published: February 2015

Voltage-gated sodium channels (VGSCs) are responsible for the initiation and propagation of action potentials in excitable cells. VGSCs in mammalian brain are heterotrimeric complexes of α and β subunits. Although β subunits were originally termed auxiliary, we now know that they are multifunctional signaling molecules that play roles in both excitable and nonexcitable cell types and with or without the pore-forming α subunit present. β subunits function in VGSC and potassium channel modulation, cell adhesion, and gene regulation, with particularly important roles in brain development. Mutations in the genes encoding β subunits are linked to a number of diseases, including epilepsy, sudden death syndromes like SUDEP and SIDS, and cardiac arrhythmia. Although VGSC β subunit–specific drugs have not yet been developed, this protein family is an emerging therapeutic target.