bluuebunny/crossref_metadata_2025 huggingface dataset:
THE KORSELT SET OF pq
Authors: ECHI OTHMAN , GHANMI NEJIB
Published: November 2011

Let α ∈ ℤ\{0}. A positive integer N is said to be an α-Korselt number (Kα-number, for short) if N ≠ α and N - α is a multiple of p - α for each prime divisor p of N. By the Korselt set of N, we mean the set of all α ∈ ℤ\{0} such that N is a Kα-number; this set will be denoted by [Formula: see text]. Given a squarefree composite number, it is not easy to provide its Korselt set and Korselt weight both theoretically and computationally. The simplest kind of squarefree composite number is the product of two distinct prime numbers. Even for this kind of numbers, the Korselt set is far from being characterized. Let p, q be two distinct prime numbers. This paper sheds some light on [Formula: see text].
ON THE REPRESENTATION OF THE POWERS OF INTEGERS IN ANY PRIME BASE
Authors: PREPARATA FRANCO P. , VACCA ROBERTO
Published: November 2011

This paper addresses the distribution of digits in the positional representation of powers of integers, a problem with a long history, and presents a complete solution when the representation base is a prime number. For any given base and exponent, the powers are viewed as a semi-infinite array whose rows are indexed by the nonnegative integers and whose columns are indexed by the representation positions. By using arguments of elementary number theory, the positions of the array are classified in a manner permitting their enumeration. Since each column is a periodic sequence, the distribution is expressed in terms of the number of occurrences (frequency) of each digit in a period.
国际移民的跨国主义实践与移民祖籍国的发展：
Authors: 阿列汗德罗·波特斯  , 周敏
Published: November 2011

无论在经济学或社会学界，以往有关发展学(development studies)的研究大多注重跨国资本流动和投资行为等宏观经济因素，同时强调行政制度和结构对发展中国家经济的影响。过去有关国际移民的研究不仅将人口跨国移动这一现象归咎于国家经济落后的原因，也同时视之为国家不发达的结果。近年来，对于移民国际汇款的研究开始注重微观的理论视角，强调移民个体和家庭的能动性。然而，这种在研究视角上的转变，对于研究国际移民与祖籍国发展的关系显然是不足的，因为它并没有考虑到移民群体自身所产生的组织和结构方面的效应，也没有考虑到在移民社团组织与祖籍国政府之间日益增长的交流，以及由此产生的促进发展的合力。本文的目的旨在深入探讨这一论题，通过对美国墨西哥裔和华裔两大移民社团的比较研究，描述移民与祖籍国 — 墨西哥和中国 — 墨西哥和的地区及国家层面的密切互动以及由此带来的发展。通过研究，我们发现移民跨国社团组织的成立和发展并不会使在国外永久定居的同胞完全放弃他们跟祖籍国的联系。相反的，那些在接收国已经取得较高社会地位以及在经济和法律上都得到保障的移民，更倾向于参与跨国活动，而移民个人跨国实践往往通过社团的方式来体现。现今交通工具的发达和便利，使永久迁移型的国际移民定期往返祖籍国的可能性大大增加，不仅扩展了跨国场域，也有利于他们在跨国场域中的施展，使他们身在国外也能参与祖籍国家乡的经济和社会生活，并为祖籍国汇入有形和无形的宝贵资源。对国际移民与祖籍国发展的因果进程进行系统的分析，有助于提出研究移民跨国主义的中层理论架构。本文还讨论了此项研究在实践和决策方面的启示。
BRANCHED METAL NANOPARTICLES: A REVIEW ON WET-CHEMICAL SYNTHESIS AND BIOMEDICAL APPLICATIONS
Authors: LI SI YUE , WANG MIN
Published: November 2011

Branched metal nanoparticles present a promising new class of materials, which have great potential as sensors, catalysts, drug carriers, and imaging agents, owing to their unique nanostructures, physicochemical properties, optical properties, and other characteristics. Many efforts have recently been devoted to the wet-chemical synthesis of branched metal nanoparticles. Seed-mediated growth and seedless growth are two main routes for producing branched metal nanoparticles. Most particle synthesis methods can be modified for different metal systems. In this review, various synthesis methods for the fabrication of branched monometallic, bimetallic, and multimetallic nanoparticles and also branched polymer core-metal nanoshell composite nanoparticles are summarized, catagorized, and discussed. The relevance and performance of such nanostructured materials with regard to their optical properties which arise from localized surface plasmon resonances are summarized, and their potential as excellent substrates for surface enhanced Raman scattering (SERS) is reviewed. Other applications of branched nanoparticles such as drug delivery vehicle, medical imaging agent, catalysis, and magnetism are briefly introduced.
NEGATIVE VOLTAGE ELECTROSPINNING AND POSITIVE VOLTAGE ELECTROSPINNING OF TISSUE ENGINEERING SCAFFOLDS: A COMPARATIVE STUDY AND CHARGE RETENTION ON SCAFFOLDS
Authors: TONG HO-WANG , WANG MIN
Published: November 2011

Positive voltage electrospinning (PVES) has been mainly used for forming fibrous polymer scaffolds for different applications including tissue engineering. There is virtually no report on negative voltage electrospinning (NVES) of tissue engineering scaffolds. In this study, NVES of four biopolymers, namely, gelatin, chitosan, poly(lactic-co-glycolic acid) (PLGA), and polybutylene terephthalate (PBT), to form nanofibrous membranes was systematically investigated. For comparisons, PVES of these polymers was also conducted. It was found that chitosan fibers could not be produced using NVES. Under NVES or PVES, the fiber diameter of electrospun scaffolds generally increased with increasing needle inner diameter and polymer solution concentration but decreased with increasing working distance for all four polymers. Neither NVES nor PVES altered the chemical structure of gelatin, PLGA, and PBT. PVES and NVES resulted in fibrous membranes bearing positive charges and negative charges, respectively. PLGA and PBT fibrous membranes retained around 30% and 50%, respectively, of the initial charge one week after electrospinning. Charges on gelatin and chitosan fibrous membranes were almost completely dissipated within 60 min of electrospinning. For all four polymers, under either PVES or NVES, the retained charges on fibrous membranes increased with increasing applied electrospinning voltage. This study explored a new approach for forming fibrous scaffolds by using NVES and has opened a new area for developing negatively charged fibrous scaffolds for tissue engineering applications.
NANOBIOMATERIALS LIBRARY SYNTHESIS FOR HIGH-THROUGHPUT SCREENING USING A DRY POWDER PRINTING METHOD
Authors: LI ZONGQI , YANG SHOUFENG
Published: November 2011

High-throughput (HT) screening and combinatorial searches for the discovery, development and optimization of functional materials have been widely accepted in many new materials discovery. Dry powder HT library synthesis have advantages such as using same powder materials in lab as in production, and avoiding the use of additives and/or solvents which could be harmful for cells. The VaryDose dry powder dispensing technology was adapted in this work to dispense nanobioceramic powders in quantities as low as 0.1 mg per dispensing. Nanocalcium phosphate biomaterials, including hydroxyapatite (HA) and β-tricalcium phosphate (β-TCP), were selected to demonstrate the library fabrication. The dispensing unit design and the effect of the dispensing parameters on dosage control and uniformity are discussed.
ELECTROHYDRODYNAMIC PROCESSING OF CALCIUM PHOSPHATES: COATING AND PATTERNING FOR MEDICAL IMPLANTS
Authors: MUNIR GILLIAN , HUANG JIE , EDIRISINGHE MOHAN , NANGREJO RAFIQUE , BONFIELD WILLIAM
Published: November 2011

Hydroxyapatite (HA)-coated metallic prostheses, which combine the osteoconductivity of HA and high strength of metallic alloys, have been increasingly the choice of joint replacement prostheses by surgeons as the general population lives longer. Surface modification of metallic implant surfaces is one of the key focal points to implantation technology. In addition to material chemistry, surface topography has been found to positively impact cellular response and is able to enhance the life time of the implant. Recently, a new technique, template-assisted electrohydrodynamic atomization (TAEA) spraying, developed using the principles of electrohydrodynamic atomization spraying, which is an electrically driven jet-based deposition method, is of considerable interest in surface topography formation. The process offers the attractive advantages of compatibility with micro-fabrication technology and versatility in pattern specification for advanced implant designs. This technology incorporates nanosized calcium phosphate to mimic the size and chemical composition of bone mineral in a micrometer-dimension pattern configuration to guide cellular responses. In vitro studies showed that both pillar and track nano Silicon-substituted HA (SiHA) patterns were able to encourage the attachment and growth of osteoblast cells, the track patterns provided the favourite surface for the initial cell attachment while a fast cell proliferation rate was found on the pillar pattern from day 1 to day 5 in comparison with that of a SiHA-coated surface. The alignment of actin cytoskeleton of osteoblast cells matched the orientation of the entire cell. The shear peel strength of the patterned interlocking nano-HA coating was found to be at least an order of magnitude higher than the conventional HA coating. Therefore, TAEA offers great potential for producing new coatings with a tailored surface topography, on both the micro- and nano-scale in a more cost effective way to enhance the performance of medical implants.
Simultaneous Measurement of Temperature Dependent Thermophysical Properties
Authors: Czél Balázs , Gróf Gyula , Kiss László
Published: November 2011

A new evaluation method for a transient measurement of thermophysical properties is presented in this paper. The aim of the research was to couple a new automatic evaluation procedure to the BICOND thermophysical property measurement method to enhance the simultaneous determination of the temperature dependent thermal conductivity and volumetric heat capacity. The thermophysical properties of two different polymers were measured and compared with the literature data and with the measurement results that were done by well-known, traditional methods. The BICOND method involves a step-down cooling, recording the temperature histories of the inner and the outer surfaces of a hollow cylindrical sample and the thermophysical properties are evaluated from the solution of the corresponding inverse heat conduction using a genetic algorithm-based method (BIGEN) developed by the authors. The BIGEN is able to find the material properties with any kind of temperature dependency, that is illustrated through the measurement results of poly(tetrafluoroethylene) (PTFE) and polyamide (PA) samples.
Characteristics of Si Solar Cells with the Addition of Frits and Additives to Al Pastes
Authors: Kim Dongsun , Kim Jongwoo , Lee Jungki , Kim Hyungsun
Published: November 2011

Thick Al films are used widely as the backside electrode material of Si solar cells. The formation of Al and a back surface field reduce the back-surface recombination and improve the cell performance. This study examined the characteristics of Si solar cells with the addition of frits and additives to Al pastes after firing. The reactions among Al powders, frits and additives were studied. The wetting behavior between each powder (Al powder, frit, additive) and Si, Al substrates was also measured as a function of the temperature. These preliminary studies show that the frits affect the adhesion between Al and Si. In addition, the proper additives prevent the bowing of Si wafer.
Analysis of Peeling Mechanism in Annealed Tungsten Silicide Thin Films
Authors: Chen Chun-Chi , Chuang Ming-Jie , Chien Hung-Ju
Published: November 2011

Tungsten silicide (WSi
x
) peeling is a noticeable issue from the manufacturing viewpoint, especially as WSi
x
is widely applied in very large scale integrated circuit (VLSI) fabrication as a gate and interconnecting material, even on a 25-nm-node NAND flash device. In this study, we attempt to determine the margin of the Si/W atomic ratios and the mechanism of WSi
x
film peeling after thermal annealing. The use of an as-deposited WSi
x > 2.0 film and 30 s rapid temperature annealing (RTP) at least 750 °C for a tungsten-rich WSi1.85 film are the minimal conditions for preventing peeling. Moreover, we found that silicon and phosphorus atoms diffuse upward on WSi
x
films, driven out of the underlying doped poly-Si film, while they acquire sufficient thermal budgets based on energy dispersive X-ray (EDX) analysis and secondary-ion mass spectroscopy (SIMS). During this process, the strong mutual interaction and the rough interface formation between the tetragonal phase of WSi
x
and polycrystalline silicon (poly-Si) enhance the adhesion of WSi
x
films. A strong adhesion might reduce the risk of peeling in the subsequent processes.
Substrate-Bias Assisted Hot Electron Injection Method for High-Speed, Low-Voltage, and Multi-Bit Flash Memories
Authors: An Ho-Myoung , Kim Hee-Dong , Zhang Yongjie , Seo Yu Jeong , Kim Tae Geun
Published: November 2011

The authors present a highly efficient program method for high-speed, low-voltage, and multi-bit/cell operation in the conventional silicon/oxide/nitride/oxide/silicon structure. This method uses a forward bias for collecting the electrons into the substrate whilst both substrate and drain biases are used for injecting the electrons into the nitride layer. With an aid of the substrate bias for electron injection, we obtained a program time as short as 600 ns and an ultralow-voltage operation with a drain voltage of 2 V and a substrate voltage of -3 V. In addition, a localized charge-injection near the junction edge was confirmed with a threshold voltage difference of 1 V between the forward and reverse read.
Thickness Dependences of Resistivity and Temperature Coefficient of Resistance for Ge Thin Films Sandwiched between Si Layers for Uncooled Infrared Imaging Sensor
Authors: Yamaki Kazuhiro , Tai Takashi , Kinoshita Junichi , Sekino Shoji , Nakamura Shin , Yoshitake Tsutomu , Furukawa Akio
Published: November 2011

An RF magnetron sputtering technique was used to deposit Ge and stacked Si/Ge films for infrared imaging sensors; the electrical characteristics of these films were estimated. The cross-sectional scanning electron microscope (SEM) image obtained confirmed that a layered Si/Ge structure was deposited on the SiO2 substrate. The layered film, annealed in an Ar atmosphere, exhibited a large temperature coefficient of resistance (TCR) (-3.63%/K) and a low resistivity (64.5 Ω·cm). The conductivity and TCR of Si/Ge films depend on the thickness of the Ge layer. A significant improvement in TCR was achieved by decreasing the thickness of the Ge layer. Ge thin films sandwiched between amorphous silicon layers facilitate the realization of a noncooled bolometer.
Open Government 2.0
Authors: Howard Alex
Published: November 2011

Social Mediator is a forum exploring the ways that HCI research and principles interact --- or might interact --- with practices in the social media world.

Joe McCarthy, Editor
Community and conflict
Authors: DiSalvo Carl
Published: November 2011

Community + Culture features practitioner perspectives on designing technologies for and with communities. We highlight compelling projects and provocative points of view that speak to both community technology practice and the interaction design field as a whole.

Tad Hirsch, Editor
Homeless young people and technology
Authors: Woelfer Jill Palzkill , Hendry David G.
Published: November 2011

In this forum we will celebrate research that helps to successfully bring the benefits of computing technologies to children, older adults, people with disabilities, and other populations that are often ignored in the design of mass-marketed products.

Juan Pablo Hourcade, Editor
Measuring fun, trust, confidence, and other ethereal constructs
Authors: Wixon Dennis
Published: November 2011

Evaluation and usability as a practice area has diversified its approaches, broadened the spectrum of UX issues it addresses, and extended its contribution into deeper levels of product-development decision making. This forum addresses conceptual, methodological, and professional issues that arise in the field's continuing effort to contribute robust information about users to product planning and design.

David Siegel and Susan Dray, Editors
Brave NUI world
Authors: Goth Gregory
Published: November 2011

Natural user interface developments, such as Microsoft's Kinect, may indicate the beginning of the end for the mouse.
Data trends on minorities and people with disabilities in computing
Authors: Taylor Valerie , Ladner Richard
Published: November 2011

Seeking a comprehensive view of minority student demographics to determine what programs and policies are needed to promote diversity.
Postmortem debugging in dynamic environments
Authors: Pacheco David
Published: November 2011

Many modern dynamic languages lack tools for understanding complex failures.
How will astronomy archives survive the data tsunami?
Authors: Berriman G. Bruce , Groom Steven L.
Published: November 2011

Astronomers are collecting more data than ever. What practices can keep them ahead of the flood?
Puzzled: Solutions and sources
Authors: Winkler Peter
Published: November 2011

Last month (Nov. 2011, p. 120) we posted a trio of brainteasers, including one as yet famously unsolved, concerning distances between points on the plane. Here, we offer solutions to two of them. How did you do?
Q&A: Scaling up
Authors: Hoffmann Leah
Published: November 2011

M. Frans Kaashoek talks about multicore computing, security, and operating system design.
A composite complexity measure for component-based systems
Authors: Kumari Usha , Bhasin Sucheta
Published: November 2011

The increasing importance of software measurement has led to design and development of new software measures. Controlling and minimizing software complexity is the most important objective of each software development paradigm because it affects all other software quality attributes like reusability, reliability, testability, maintainability etc. For this purpose, a number of software complexity measures have been reported to quantify different aspects of complexity. Component-based software development (CBSD) is an evolving paradigm where emphasis is laid on reuse of existing components and effective designing of new components. As the development of component-based software is rising, more and more complexity metrics are being developed for the same. In this paper, we have attempted to design a composite complexity measure to quantify important aspects of complexity of a component-based system. The proposed measure takes into account two major complexities of a component-based system : one due to individual component and the other due to its interaction with other components. Individual component complexity may arise due to size of a component, type and nesting level of control structures present in code component. Component's interaction complexity may be due to its interface with other components. Graph theoretic notions and concept of weights have been used to illustrate interaction among software components and to compute complexity. The proposed measure has been applied to four cases chosen for present study and yields quiet encouraging results which may further help in controlling the complexity of component-based systems so as to minimize both integration and maintenance efforts.
Time boxing planning
Authors: Miranda Eduardo
Published: November 2011

Time boxing is a management technique which prioritizes schedule over deliverables but time boxes which are merely a self, or an outside, imposed target without agreed partial outcomes and justified certainty are at best, an expression of good will on the part of the team. This essay proposes the use of a modified set of Moscow rules which accomplish the objectives of prioritizing deliverables and providing a degree of assurance as a function of the uncertainty of the underlying estimates.
Analyzing test case selection & prioritization using ACO
Authors: Suri Bharti , Singhal Shweta
Published: November 2011

Regression testing is primarily a maintenance activity that is performed frequently to ensure the validity of the modified software. In such cases, due to time and cost constraints, the entire test suite cannot be run. Thus, it becomes essential to select or prioritize the tests in order to cover maximum faults in minimum time. Recently, Ant Colony Optimization (ACO), which is a new way to solve time constraint prioritization problem, has been utilized. This paper presents the analysis of the regression test prioritization technique to reorder test suites in time constraint environment along with the sample runs on various programs. Our analysis concluded that the ACO finds better orderings at higher values of the time constraint (TC). The correctness of the technique has also been recorded to be near optimal at an average.
Reliability of component based systems
Authors: Tyagi Kirti , Sharma Arun
Published: November 2011

Software reliability is defined as the probability of the failure free operation of a software system for a specified period of time in a specified environment. Day by day software applications are growing more complex and with more emphasis on reuse. Component Based Software (CBS) applications have emerged. The focus of this paper is to provide an overview for the state of the art of Component Based Systems reliability estimation. In this paper, we discussed various approaches in terms of their scope, model, methods, technique and validation scheme. This comparison provides insight into determining the direction of future CBS reliability research.
How to measure and optimize reliable embedded software
Authors: Broster Ian , Coombes Andrew
Published: November 2011

This tutorial explores some of the challenges of measuring performance and timing behaviour of reliable embedded systems and explains techniques and strategies for optimization of reliable software. The tutorial explains and compares different techniques for measurement and analysis of software on embedded targets including tracing methods, in-memory analysis and using hardware support. It shows how those techniques can be used for verification of non-functional properties on-target, including in the context of DO178B/C and the new ISO26262 standard to meet the requirements for safety in automobiles. The tutorial presents optimization at a high and low level, looking at strategies and the tradeoffs that occur in reliable software development, introducing a process that helps to ensure that optimization can have the maximum benefit for the minimum effort.
Service-oriented architecture (SOA)concepts and implementations
Authors: Sward Ricky E. , Boleng Jeff
Published: November 2011

This tutorial explains how to implement a Service-Oriented Architecture (SOA) for reliable systems using Enterprise Service Bus (ESB) technologies. The first half of the tutorial describes terms of Service-Oriented Architectures (SOA) including service, service registry, service provider, service consumer, Simple Object Access Protocol (SOAP), Representational State Transfer (REST), and Web Service Description Language (WSDL). Several examples of REST and SOAP web services are provided using the Ada Web Server (AWS). This tutorial also presents principles of SOA including loose coupling, encapsulation, composibility of web services, and statelessness of web services. The tutorial covers the benefits of SOA and organizations that are supporting SOA infrastructure. The second half of the tutorial covers Enterprise Service Bus (ESB) technologies including definitions, capabilities, benefits and drawbacks. The tutorial discusses the difference between SOA and an ESB, as well as some of the commercially available ESB solutions on the market. The Mule ESB is explored in more detail and several examples are given. Several examples of using an ESB in a SOA application are given using AWS as an Ada implementation. An AWS server is built in the examples and connected to the ESB providing REST and SOAP web services. AWS allows the developer to expose services in a high-integrity system using the Ada and SPARK programming languages. This tutorial is slightly different than the one given at Ada Europe 2008 in that it will focus more on the application of SOA and ESB technology to reliable, high-integrity systems. All tutorial material will be provided to attendees and the opportunity for hands-on participation in examples will be possible.
Improving quality of Ada software with range analysis
Authors: Abraham Jay , Chapple Jeff , Preve Cyril
Published: November 2011

Ada is a strong language with built-in mechanisms that naturally lead to less risky software programs. This is possible because Ada is a structured and strongly typed language with built-in run-time protection mechanisms. For example, subtyping allows for specification of ranges for variable. The compiler can detect illegal values for these variables as well as insert run-time range checks during compilation so that violating specified ranges result in a Constraint_Error during run-time. For complex embedded systems where quality and reliabiity are imperative, the Ada programming language alone may not provide sufficient quality margins. Demonstrating run-time robustness with exhaustive dynamic testing is not possible. Formal methods with mathematical proofs enables precise determination of some properties of a complex system without the need for exhaustive analysis. This technique can be exploited statically to exhaustively determine dynamic runtime behavior of software programs. Coupling the Ada language with these state of the art verification solutions may improve the predictability of quality and safety. This tutorial examines software verification and testing approaches that have been applied to Ada programs. These techniques will be compared and contrasted with formal methods based techniques that can statically produce accurate variable range analysis of Ada programs. Concrete technical examples will be explored to see how these verification techniques, in particular the use of range analysis, can be used to improve the quality and safety of complex software systems that are developed in Ada.
Introduction to Ada
Authors: Feldman Michael
Published: November 2011

Level -- Beginner, but attendees should have some experience with a high-level programming language.

This tutorial is designed for those who have some familiarity with a programming language, but who are new to Ada. In the morning, we will discuss the basics of programming in Ada, including types, packages, syntax rules, and other Ada programming constructs. In the afternoon, we will briefly cover Ada's object-oriented programming and concurrent-programming features. Many examples will be shown; freely downloadable Ada programming environments and tools will be discussed.
Experimenting with parasail
Authors: Taft S. Tucker
Published: November 2011

This tutorial provides an opportunity to experiment with a new language designed to support the safe, secure, and productive development of parallel programs. ParaSail is a new language with pervasive parallelism coupled with extensive compile-time checking of annotations in the form of assertions, preconditions, postconditions, etc. ParaSail does all checking at compile time, and eliminates race conditions, null dereferences, uninitialized data access, numeric overflow, out of bounds indexing, etc. as well as statically checking the truth of all user-written assertions. After a short introduction to the language, attendees will receive a prototype ParaSail compiler and an accompanying ParaSail Virtual Machine interpreter for writing and testing ParaSail programs. The tutorial/workshop will finish with a group discussion and feedback on the experience of using this new language.
Everything i know i learned from ada
Authors: Booch Grady
Published: November 2011

I entered the world of Ada at a most impressionable time in my career: I knew enough to be dangerous, but not so much that I was unwilling to try new things. Ada was full of new things that have informed much of what I do today. The role of abstraction, the meaning of beauty in design, the nature of delivering ultra-large software-intensive systems, collaboration across geographic and cultural boundaries, the joys and frustrations of standards building, the process of revolution: these are all things I have learned from Ada. In this presentation, I'll offer some war stories from the past and offer speculation on the future.
A parallel programming model for ada
Authors: Ali Hazem Ismail , Pinho Luís Miguel
Published: November 2011

Over the last three decades, computer architects have been able to achieve an increase in performance for single processors by, e.g., increasing clock speed, introducing cache memories and using instruction level parallelism. However, because of power consumption and heat dissipation constraints, this trend is going to cease. In recent times, hardware engineers have instead moved to new chip architectures with multiple processor cores on a single chip. With multi-core processors, applications can complete more total work than with one core alone. To take advantage of multi-core processors, parallel programming models are proposed as promising solutions for more effectively using multi-core processors. This paper discusses some of the existent models and frameworks for parallel programming, leading to outline a draft parallel programming model for Ada.
Software vulnerabilities precluded by spark
Authors: Tokar PhD Joyce L. , Jones F. David , Black PhD Paul E. , Dupilka Chris E.
Published: November 2011

Software vulnerabilities are defined as a property of a system's security requirements, design, implementation, or operation that could be accidentally triggered or intentionally exploited and result in a security failure [1]. Many organizations throughout the world are studying software vulnerabilities and how they allow software applications to be infiltrated and corrupted. The Common Weakness Enumeration (CWE) [2] is a collection of standard, measurable weaknesses that may be used to assess software tools and services. The CWE may be also be used to document known vulnerabilities and improve communication between parties working on software assurance. The SPARK programming language and toolset [3, 4] is designed for the development of high assurance software. The SPARK programming language is a subset of the Ada programming language plus a collection of annotations intended to provide a programming language that is unambiguous, free from implementation dependencies, and formally defined. Used together, the SPARK language and toolset enable the prevention and elimination of defects in source code during the development of the code. This paper presents an analysis of the SPARK programming language against a collection of CWEs.
Enhancing spark's contract checking facilities using symbolic execution
Authors: Belt Jason , Hatcliff John , Robby  , Chalin Patrice , Hardin David , Deng Xianghua
Published: November 2011

Spark, a subset of Ada for engineering safety and security-critical systems, is one of the best commercially available frameworks for formal-methods-supported development of critical software. Spark is designed for verification and includes a software contract language for specifying functional properties of procedures. Even though Spark and its static analysis components are beneficial and easy to use, its contract language is rarely used for stating properties beyond simple constraints on scalar values due to the burdens the associated tool support imposes on developers. Symbolic execution (SymExe) techniques have made significant strides in automating reasoning about deep semantic properties of source code. However, most work on SymExe has focused on bug-finding and test case generation as opposed to tasks that are more verification-oriented such as contract checking. In previous work we have presented: (a) SymExe techniques for checking software contracts in embedded critical systems, and (b) Bakar Kiasan, a tool that implements these techniques in an integrated development environment for Spark. In this paper, we give a detailed walk-through of Bakar Kiasan as it is applied to an industrial code base for an embedded security device. We illustrate how Bakar Kiasan provides significant increases in automation, usability, and functionality over existing Spark contract checking tools, and we present results from performance evaluations of its application to industrial examples.
Making the non-executable ACATS tests executable
Authors: Eilers Dan R. , Koskinen Tero
Published: November 2011

The Ada Conformity Assessment Test Suite (ACATS) includes both positive and negative tests. The negative tests have intentional errors that a compiler is intended to diagnose with a compile-time error message. Interestingly, the negative tests also include numerous "OK" lines that the compiler must not reject. But the absence of an error message on the "OK" lines is not always a convincing demonstration that the "OK" lines were correctly compiled, since the negative tests are not executable. By removing the intentional errors from a copy of each negative test, we are able to compile and run the resulting modified tests, demonstrating more convincingly that the "OK" lines are correctly compiled.
Model Design of Piezoelectric Micromachined Modal Gyroscope
Authors: Hu Xiaojun , Wu Xiaosheng , Wang Zheng , Chen Wenyuan , Zhang Weiping
Published: November 2011

This paper reports a novel kind of solid-state microgyroscope, which is called piezoelectric micromachined modal gyroscope (PMMG). PMMG has large stiffness and robust resistance to shake and strike because there is no evident mass-spring component in its structure. This work focused on quantitative optimization of the gyroscope, which is still blank for such gyroscope. The modal analysis by the finite element method (FEM) was firstly conducted. A set of quantitative indicators were developed to optimize the operation mode. By FEM, the harmonic analysis was conducted to find the way to efficiently actuate the operational mode needed. The optimal configuration of driving electrodes was obtained. At last, the Coriolis analysis was conducted to show the relation between angular velocity and differential output voltage by the Coriolis force under working condition. The results obtained in this paper provide theoretical basis for realizing this novel kind of micromachined gyroscope.
Laplace‐Type Semi‐Invariants for a System of Two Linear Hyperbolic Equations by Complex Methods
Authors: Mahomed F. M. , Qadir A. , Ramnarain A.
Published: November 2011

In 1773 Laplace obtained two fundamental semi‐invariants, called Laplace invariants, for scalar linear hyperbolic partial differential equations (PDEs) in two independent variables. He utilized this in his integration theory for such equations. Recently, Tsaousi and Sophocleous studied semi‐invariants for systems of two linear hyperbolic PDEs in two independent variables. Separately, by splitting a complex scalar ordinary differential equation (ODE) into its real and imaginary parts PDEs for two functions of two variables were obtained and their symmetry structure studied. In this work we revisit semi‐invariants under equivalence transformations of the dependent variables for systems of two linear hyperbolic PDEs in two independent variables when such systems correspond to scalar complex linear hyperbolic equations in two independent variables, using the above‐mentioned splitting procedure. The semi‐invariants under linear changes of the dependent variables deduced for this class of hyperbolic linear systems correspond to the complex semi‐invariants of the complex scalar linear (1 + 1) hyperbolic equation. We show that the adjoint factorization corresponds precisely to the complex splitting. We also study the reductions and the inverse problem when such systems of two linear hyperbolic PDEs arise from a linear complex hyperbolic PDE. Examples are given to show the application of this approach.
Prevalence of XMRV Nucleic Acid and Antibody in HIV-1-Infected Men and in Men at Risk for HIV-1 Infection
Authors: Spindler J. , Hackett J. , Qiu X. , Wiegand A. , Boltz V. F. , Swanson P. , Bream J. H. , Jacobson L. P. , Li X. , Rinaldo C. R. , Wolinsky S. M. , Coffin J. M. , Kearney M. F. , Mellors J. W.
Published: November 2011

Xenotropic MLV-Related Virus (XMRV) was recently reported to be associated with prostate cancer and chronic fatigue syndrome (CFS). Infection was also reported in 3.7% of healthy individuals. These highly reported frequencies of infection prompted concerns about the possibility of a new, widespread retroviral epidemic. The Multicenter AIDS Cohort Study (MACS) provides an opportunity to assess the prevalence of XMRV infection and its association with HIV-1 infection among men who have sex with men. Reliable detection of XMRV infection requires the application of multiple diagnostic methods, including detection of human antibodies to XMRV and detection of XMRV nucleic acid. We, therefore, tested 332 patient plasma and PBMC samples obtained from recent visits in a subset of patients in the MACS cohort for XMRV antibodies using Abbott prototype ARCHITECT chemiluminescent immunoassays (CMIAs) and for XMRV RNA and proviral DNA using a XMRV single-copy qPCR assay (X-SCA). Although 9 of 332 (2.7%) samples showed low positive reactivity against a single antigen in the CMIA, none of these samples or matched controls were positive for plasma XMRV RNA or PBMC XMRV DNA by X-SCA. Thus, we found no evidence of XMRV infection among men in the MACS regardless of HIV-1 serostatus.
A New Method for Airborne Sound Detection Using Total Internal Reflection and Its Application to Microphone
Authors: Suzuki Yasushi , Kido Ken'iti
Published: November 2011

A new method for detecting the sound pressure in air, which uses the total internal reflection at the curved interface between glass and air, is proposed, and its application to microphone is discussed. The critical angle for total reflection changes by the refractive index of air, which depends on the air density. The density changes by the sound pressure. Therefore, the sound pressure is measurable by detecting the intensity of the reflected light from the total reflection area. The sound pressure sensitivity of the proposed method is investigated theoretically and experimentally. Experimental results show that the microphone using the method is feasible though its sensitivity is low in the present stage. When the sensitivity is improved dramatically for practical use, the microphone becomes very sensitive to the surrounding conditions. A method to compensate the fluctuation of atmospheric pressure or temperature is presented.
It Takes a Community to Raise the Prevalence of a Zoonotic Pathogen
Authors: Brisson Dustin , Brinkley Catherine , Humphrey Parris T. , Kemps Brian D. , Ostfeld Richard S.
Published: November 2011

By definition, zoonotic pathogens are not strict host-species specialists in that they infect humans and at least one nonhuman reservoir species. The majority of zoonotic pathogens infect and are amplified by multiple vertebrate species in nature, each of which has a quantitatively different impact on the distribution and abundance of the pathogen and thus on disease risk. Unfortunately, when new zoonotic pathogens emerge, the dominant response by public health scientists is to search for a few, or even the single, most important reservoirs and to ignore other species that might strongly influence transmission. This focus on the single “primary” reservoir host species can delay biological understanding, and potentially public health interventions as species important in either amplifying or regulating the pathogen are overlooked. Investigating the evolutionary and ecological strategy of newly discovered or emerging pathogens within the community of potential and actual host species will be fruitful to both biological understanding and public health.
Comparative Structures and Evolution of Vertebrate Carboxyl Ester Lipase (CEL) Genes and Proteins with a Major Role in Reverse Cholesterol Transport
Authors: Holmes Roger S. , Cox Laura A.
Published: November 2011

Bile-salt activated carboxylic ester lipase (CEL) is a major triglyceride, cholesterol ester and vitamin ester hydrolytic enzyme contained within pancreatic and lactating mammary gland secretions. Bioinformatic methods were used to predict the amino acid sequences, secondary and tertiary structures and gene locations forCELgenes, and encoded proteins using data from several vertebrate genome projects. A proline-rich and O-glycosylated 11-amino acid C-terminal repeat sequence (VNTR) previously reported for human and other higher primate CEL proteins was also observed for other eutherian mammalian CEL sequences examined. In contrast, opossum CEL contained a single C-terminal copy of this sequence whereas CEL proteins from platypus, chicken, lizard, frog and several fish species lacked the VNTR sequence. VertebrateCELgenes contained 11 coding exons. Evidence is presented for tandem duplicatedCELgenes for the zebrafish genome. Vertebrate CEL protein subunits shared 53–97% sequence identities; demonstrated sequence alignments and identities for key CEL amino acid residues; and conservation of predicted secondary and tertiary structures with those previously reported for human CEL. Phylogenetic analyses demonstrated the relationships and potential evolutionary origins of the vertebrateCELfamily of genes which were related to a nematode carboxylesterase (CES) gene and five mammalianCESgene families.
Synthesis, Property Characterization, and Photocatalytic Activity of Novel Visible Light-Responsive Photocatalyst
Authors: Luan Jingfei , Hu Zhitian
Published: November 2011

Fe2BiSbO7was synthesized by a solid-state reaction method for the first time. The structural and photocatalytic properties of Fe2BiSbO7have been characterized. The results showed that Fe2BiSbO7was crystallized with the pyrochlore-type structure, cubic crystal system, and space groupFd3m. The lattice parameter for Fe2BiSbO7was  Å. The photocatalytic degradation of methylene blue (MB) was realized under visible light irradiation with Fe2BiSbO7as catalyst. Fe2BiSbO7owned higher catalytic activity compared with Bi2InTaO7or pure TiO2or N-doped TiO2for photocatalytic degradation of MB. The photocatalytic degradation of MB with Fe2BiSbO7, Bi2InTaO7, or N-doped TiO2followed the first-order reaction kinetics, and the first-order rate constant was 0.01189, 0.00275, or 0.00333 min−1. After visible light irradiation for 230 min with Fe2BiSbO7, complete removal and mineralization of MB was observed. The reduction of the total organic carbon, the formation of inorganic products, and , and the evolution of CO2revealed the continuous mineralization of MB during the photocatalytic process. The photocatalytic degradation pathway of MB was obtained. Fe2BiSbO7/(visible light) photocatalysis system was found to be suitable for textile industry wastewater treatment.
Engineered Hybrid Scaffolds of Poly(vinyl alcohol)/Bioactive Glass for Potential Bone Engineering Applications: Synthesis, Characterization, Cytocompatibility, and Degradation
Authors: Costa Hermes S. , Mansur Alexandra A. P. , Pereira Marivalda M. , Mansur Herman S.
Published: November 2011

The synthesis, characterization, preliminary cytocompatibility, and degradation behavior of the hybrids based on 70% Poly(vinyl alcohol) and 30% bioactive glass (58SiO2–33CaO–9P2O5, BaG) with macroporous tridimensional structure is reported for the first time. The effect of glutaraldehyde covalent crosslinker in the organic‐inorganic nanostructures produced and, as a consequence, tailoring the hybrids properties was investigated. The PVA/BaG hybrids scaffolds are characterized by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), X‐ray diffraction (XRD), and X‐ray Microcomputed tomography analysis (μCT). Cytotoxicity assessment is performed by the MTT method with VERO cell culture. Additionally, the hybrid in vitro degradation assay is conducted by measuring the mass loss by soaking in deionized water at 37°C for up to 21 days. The results have clearly shown that it is possible to modify the PVA/BaG hybrids properties and degradation behavior by engineering the structure using different concentrations of the chemical crosslinker. Moreover, these hybrid crosslinked nanostructures have presented 3D hierarchical pore size architecture varying within 10–450 μm and a suitable cytocompatibility for potential use in bone tissue engineering applications.
Future Perspectives for the Development of Chemotherapy for Advanced Gastric Cancer: Japanese and Global Status
Authors: Higuchi Katsuhiko , Tanabe Satoshi , Azuma Mizutomo , Sasaki Tohru , Ishido Kenji , Koizumi Wasaburo
Published: November 2011

In Japan, gastric cancer is the second leading cause of cancer-related mortality after lung cancer. Many randomized trials of various chemotherapeutic regimens have been conducted, contributing to improved outcomes in patients with advanced gastric cancer (AGC). The standard regimen for AGC is a combination of S-1 and cisplatin in Japan. Recently, new drug development has focused on molecular target agents, and personalized therapy for AGC has just begun. In patients with human epidermal growth factor receptor 2-positive AGC, trastuzumab in combination with chemotherapy improves survival. Furthermore, abundant information about the heterogeneity and biological backgrounds of AGC patients has been compiled. New strategies for the development of personalized therapy should be studied in the future.
Functional –1149 G/T Polymorphism of the Prolactin Gene in Schizophrenia
Authors: Rybakowski Janusz K. , Dmitrzak-Weglarz Monika , Kapelski Pawel , Hauser Joanna
Published: November 2011

Background: Prolactin in schizophrenia is considered in the context of antipsychotic drug-induced hyperprolactinemia. However, the European First Episode Schizophrenia Trial showed that hyperprolacti nemia occurred in a significant proportion of drug-naïve first-episode schizophrenia patients, which shows that it may also be caused by other factors, including genetic predisposition. Therefore, we investigated the functional polymorphism of the prolactin gene in schizophrenic patients compared with control subjects. Method: The experimental group consisted of 403 patients with schizophrenia: 202 females and 201 males. The control group consisted of 653 subjects: 377 females and 276 males. The functional polymorphism –1149 G/T (rs1341239) of the prolactin gene was genotyped using the TaqMan single-nucleotide polymorphism allelic discrimination method. Results: The distribution of genotypes in schizophrenic patients was significantly different from those of the control subjects (p = 0.031). After breaking down by gender, for male patients, the difference versus control males was significant for both genotypes and alleles (p = 0.031 and p = 0.002, respectively), with allele G being observed more frequently in schizophrenic patients. Conclusion: The results may suggest a possible abnormality of the functional –1149 G/T polymorphism of the prolactin gene in schizophrenia, especially in male patients, similar to that found in autoimmune diseases such as systemic lupus erythematosus and rheumatoid arthritis. This could also correspond with an autoimmune pathogenesis of schizophrenia.