bluuebunny/crossref_metadata_2025 huggingface dataset:
A Broadband Dielectric Measurement Technique: Theory, Experimental Verification, and Application
Authors: Dong Xiaobo , Wang Yu-Hsing
Published: March 2009

A wide-frequency dielectric spectrum can provide meaningful information that is intimately related to the properties of soils. A small-sized sensor allows the assessment of local dielectric characteristics of soils and is conducive for long-term monitoring as it can be buried in the soil sample without causing significant perturbations. Considering these advantages, the objective of this study is to explore the broadband measurement of complex permittivity ranging from kHz up to GHz using a slim-form open-ended coaxial probe with an outside diameter of [Formula: see text]. The measurements are conducted in three different frequency ranges, i.e., high frequency (HF, [Formula: see text]), medium frequency (MF, [Formula: see text]), and low frequency (LF, [Formula: see text]), in view of pertinent aperture admittance models, feasible measurement principles, and required calibrations for system biases. These considerations are described and discussed in turn from the high-frequency measurements to the low-frequency tests. Verification of the associated measurement techniques in the three operating frequency regimes is provided by experiments on pure ethanol and methanol liquids as well as on sodium chloride solutions of different concentrations. These testing techniques are also applied to measure the broadband dielectric spectrum of kaolinite sediment. Simple analyses focusing on multiple relaxations, which are associated with bulk water polarization, bound water polarization, and spatial polarization are presented.
Do People Mix at Mixers? Structure, Homophily, and the “Life of the Party”
Authors: Ingram Paul , Morris Michael W.
Published: March 2009

We used electronic name tags to conduct a fine-grained analysis of the pattern of socializing dynamics at a mixer attended by about 100 business people, to examine whether individuals in such minimally structured social events can initiate new and different contacts, despite the tendency to interact with those they already know or who are similar to them. The results show that guests did not mix as much as might be expected in terms of making new contacts. They were much more likely to encounter their pre-mixer friends, even though they overwhelmingly stated before the event that their goal was to meet new people. At the same time, guests did mix in the sense of encountering others who were different from themselves in terms of sex, race, education, and job. There was no evidence of homophily (attraction to similar others) in the average encounter, although it did operate for some guests at some points in the mixer. Results also revealed a phenomenon that we call “associative homophily,” in which guests were more likely to join and continue engagement with a group as long as it contained at least one other person of the same race as them. We consider the implications of these results for organizations and individuals seeking to develop their networks and for theories of network dynamics.
Contingent Political Capital and International Alliances: Evidence from South Korea
Authors: Siegel Jordan
Published: March 2009

Though prior research has suggested that a company's ties to political networks have only a positive value or no value, this study examines whether political network ties can also be a significant liability for companies. Analyzing South Korea as a representative emerging economy, I find that being tied through elite sociopolitical networks to the regime in power significantly increased the rate at which South Korean companies formed cross-border strategic alliances, but also that being tied through elite sociopolitical networks to the political enemies of the regime in power significantly decreased that rate. Results show that an unexpected change in political regime could quickly change a political liability into an asset and that network ties continued to be important determinants of cross-border alliance activity as South Korea proceeded with liberalization. The present study sheds further light on the so-called dark side of embeddedness by focusing on who is negatively targeted by having the “wrong friends” at the wrong time. Just as positive ties can lead to favor exchange and other benefits for companies, negative ties can lead companies to be the victims of discrimination, resource exclusion, and even occasional expropriation and sabotage between rival sociopolitical networks.
The Network Structure of Exploration and Exploitation
Authors: Lazer David , Friedman Allan
Published: March 2009

Whether as team members brainstorming or cultures experimenting with new technologies, problem solvers communicate and share ideas. This paper examines how the structure of communication networks among actors can affect system-level performance. We present an agent-based computer simulation model of information sharing in which the less successful emulate the more successful. Results suggest that when agents are dealing with a complex problem, the more efficient the network at disseminating information, the better the short-run but the lower the long-run performance of the system. The dynamic underlying this result is that an inefficient network maintains diversity in the system and is thus better for exploration than an efficient network, supporting a more thorough search for solutions in the long run. For intermediate time frames, there is an inverted-U relationship between connectedness and performance, in which both poorly and well-connected systems perform badly, and moderately connected systems perform best. This curvilinear relationship between connectivity and group performance can be seen in several diverse instances of organizational and social behavior.
Radiographie evaluation of restaurations of endodontically treated teeth with individual post
Authors: Zivkovic Slavoljub , Jefic Bojana , Miletic Vesna , Lazic Vojkan
Published: March 2009

Timely und quality restauration of endodontically treated teeth is one of the major conditions for success of endodontic therapy. The aim of this study was to determine the efficiency of individual post cemented in endodontically treated teeth using radiographie parameters. 142 endodontically treated teeth restored with individual posts and permanent prosthetic restaurations were included in the clinical and radiographie research. The results of radiographie analysis reveled correctly made and cemented posts in 64% of the cases, inadequately placed posts in 14,4% and inadequate obturation between the tip of the post and radiographie apex, in 19,9% of the case. As a conclusion, correct course of endodontic treatment, clinicians knowing of anatomomorphological characteristics of root canals, correct gutta-percha removal and clinicians adaptibility to a specific case, are essential for the correct restauration of endodonticaly treated teeth with individual posts.
Correction of incisor malpositions in mixed dentition with 2x4 orthodontic appliance
Authors: Karadjinovic Drasko , Vidovic Branislav
Published: March 2009

Depending of indication, malocclusion in mixed dentition can be treated by removable or fixed orthodontic appliances. Malpositions of permanent incisors are successfully treated with 2x4 orthodontic appliance representing economical, safer and simple solution for contemporary general dentists, paedodontists and orthodontists.
Application of different light sources for polymerization of restorative resins
Authors: Blazic Larisa , Zivkovic Slavoljub , Stojsin Ivana
Published: March 2009

The aim of this work was the introduction of the basic characteristics of contemporary polymerization light sources for composite resin curing. Two basic groups of available curing technologies are introduced. First are those that produce white light (conventional halogen lamps and plasma arc polymerization units). The second group comprises "blue light" curing devices that produce blue light at the origin of the light source. Lights belonging to this group include the blue LEDs and argon laser. Information about main characteristics of light sources (irradiance, wavelength range) and their proper choice could have a significant impact on polymerization quality and on long-life of composite restoration.
Publications in English in biomedical sciences - Part I: Proper use of prepositions
Authors: Todorovic Gordana , Todorovic Ljubomir
Published: March 2009

It is well known that English represents the main language of communication in contemporary biomedical sciences. One of the major problems that occur in communication (both oral and written) in English, which should not be underestimated, is the correct usage of the language by authors whose mother tongue is not English. Our aim was to single out the most common and frequent mistakes made in the use of prepositions so that they could be avoided by authors of scientific papers in English.
Finding Homologs in Amino Acid Sequences Using Network BLAST Searches
Authors: Ladunga Istvan (Steve)
Published: March 2009

The Basic Local Alignment Search Tool (BLAST) is the most fundamental (and most misused) algorithm and software in bioinformatics/computational biology for functional assessment of unknown proteins or discovery of similar proteins with potentially common evolutionary origins. We show how to balance sensitivity with selectivity (without generating massive output) by selecting and demonstrating proper database, algorithm, and alignment display options of the user‐friendly Web sites of the National Center for Biotechnology Information (NCBI). We discuss protein query searches against protein databases and submission of all combinations of translated searches. Careful biological and statistical inferences are drawn to possible functions, taking into account the highly nonrandom nature of proteins. Guidelines for such inferences, using real‐life biological examples (e.g., protein kinases with widely distributed structural and functional domains), are provided. We show how to avoid incorrect functional inference from misleading similarities, using the divergent evolution of a serine protease domain that erodes the protease function in haptoglobins. Curr. Protoc. Bioinform. 25:3.4.1‐3.4.34. © 2009 by John Wiley & Sons, Inc.
Using RepeatMasker to Identify Repetitive Elements in Genomic Sequences
Authors: Tarailo‐Graovac Maja , Chen Nansheng
Published: March 2009

RepeatMasker is a popular software tool widely used in computational genomics to identify, classify, and mask repetitive elements, including low‐complexity sequences and interspersed repeats. RepeatMasker searches for repetitive sequence by aligning the input genome sequence against a library of known repeats, such as Repbase. Here, we describe two Basic Protocols that provide detailed guidelines on how to use RepeatMasker, either via the Web interface or command‐line Unix/Linux system, to analyze repetitive elements in genomic sequences. Sequence comparisons in RepeatMasker are usually performed by the alignment program cross_match, which requires significant processing time for larger sequences. An Alternate Protocol describes how to reduce the processing time using an alternative alignment program, such as WU‐BLAST. Further, the advantages, limitations, and known bugs of the software are discussed. Finally, guidelines for understanding the results are provided. Curr. Protoc. Bioinform. 25:4.10.1‐4.10.14. © 2009 by John Wiley & Sons, Inc.
Artificial Neural Networks
Authors: Wang Lipo , Fu Kiuju
Published: March 2009

Artificial neural networks (ANNs) are computational models inspired from the thinking pattern of human brain. ANNs can learn and generalize from experiences, and they can abstract essential information from data. ANNs are trained to “think” like humans by strengthening or weakening interconnected weights that connect processing elements of ANNs. In the literature, the terms “neuron,” “cell,” and “unit” are usually used interchangeably for representing processing elements of neural networks.
Authentication, Access Control, and Information Flow
Authors: Ray Arnab
Published: March 2009

With the enormous quantity of sensitive information (financial and personal data, medical records) that is being stored inside computer‐based systems on a daily basis, the survival of our modern economy depends critically on the storage of these data and the intergrity of the transactions that operate on it. When trying to analyze whether a certain computer‐based system is “secure,” engineers typically question the authentication, message authentication, intergrity, and access control, In this article, we discuss each concept in detail with special attention paid to their actual implementation in real‐world software systems.
Clusters and Grids
Authors: Prodan Rodu
Published: March 2009

Over the past 10–15 years,cluster computinghas emerged as a viable alternative to MPPs by offering a significantly superior price/performance ratio. Normally, a cluster consists of hundreds or thousands of personal computers (PCs) or workstations interconnected through commodity network cards. One can recognize the difference between a cluster and an MPP similar to that between a mainframe computer and a Personal Computer (PC). Both possess a Central Processing Unit (CPU), random access memory, disks, one operating system, and so on. On the mainframe, everything works a lot faster than on the PC, but it lags behind in terms of quality and requires additional effort and cost for maintenance and administration. The same holds true between MPPs and clusters. Originally, MPPs excelled mostly because of the proprietary high‐performance interconnections between standard processors, such as Intel Pentium, Sun UltraSPARC, or PowerPC. Following the analogy with mainframes being replaced by PCs, cluster architectures are nowadays a viable replacement for MPPs, the driving force that enabled this transition being the rapid improvement in the availability of commodity high‐performance components for PCs/workstations and networks. These technologies are making a network/cluster of computers an appealing vehicle for cost‐effective parallel processing, and it is consequently leading to low‐cost commodity supercomputing.
Data Mining
Authors: Wu Xindong , Zhang Yan , Zhu Xingquan
Published: March 2009

Data mining, or knowledge discovery in databases (KDD), is an interdisciplinary field that integrates techniques from several research areas, which include machine learning, statistics, database systems, and pattern recognition, for the analysis of large volumes of possibly complex, highly distributed and poorly organized data. The increasing volumes of data collections in all fields of human endeavors as well as the imminent need of discovering useful knowledge are two factors that promote the popularity of this field. In this article, we discuss the major steps in a data‐mining process and the main topics in data‐mining research and development, and we review the challenging problems and influential algorithms.
Design Patterns
Authors: Ku Cyril S.
Published: March 2009

This manuscript describes design patterns in the object‐oriented software design and development process. It discusses software reusability and the benefits of design patterns. The Gang‐of‐Four patterns and examples of their usage are presented extensively. A detailed example of the observer pattern is given, and other patterns are briefly described.
Algorithm‐Based Fault‐Tolerant Cryptography
Authors: Zhang C. N. , Liu Xiao Wei
Published: March 2009

The algorithm‐based fault‐tolerant (ABFT) scheme has been applied to computation‐intensive tasks for couple of years. This technique mainly deals with matrix operations that are capable of using the ready‐made ALUs in certain protocol architectures. Besides, the ABFT‐based fault‐tolerant scheme can be performed concurrently with the cryptographic processes. In that case, overhead associated with the additional redundancy can be reduced. Because of the advantages compared with other fault‐tolerant methods, we adjust and integrate the ABFT technique into error detection and correction schemes for symmetric key encryption/decryption and hash function cryptosystem. RC4, AES, and SHA‐512 are specified examples set for conventional stream ciphers, block ciphers, and hash functions, respectively, to show our claim. These proposed approaches can provide simple computation, robust fault tolerance, reasonable overhead, and fast error detection/correction also, which make ABFT‐based schemes practical and useful.
Financial Applications: Stock Markets
Authors: Chen Shu‐Heng
Published: March 2009

The integration of computer science, computer technology, and finance has given rise to the field known as computational finance. Depending on its involvement in economic theory and its contribution to economic theory, computational finance can be divided into financial engineering and agent‐based computational finance. Financial engineering can be defined as the application of computational tools or algorithms to tackle some already existing financial optimization problems, such as forecasting, investment, portfolios, trading, and pricing. These applications usually do not challenge the fundamental principles (assumptions or axioms) from which the optimization problems are derived. They simply take advantage of the increasing computational power to address great technical difficulties inherent in financial optimization, such as nonlinearities and high dimensionality. Compared to financial engineering, agent‐based computational finance has a more general goal. It questions the foundations up on which mainstream economics and finance are built, and it reexamines some missing elements, which were absent mainly due to the limited computational resources. Then, by bringing back these elements, agent‐based computational finance attempts to provide us with a better understanding of the financial market dynamics.
Input Devices
Authors: LaViola Joseph J.
Published: March 2009

Input devices are fundamental to interaction with computer systems. They provide users with the ability to communicate effectively with machines by sensing information about the real world. In this article, we examine several types of input devices in use today, which include pointing devices, joysticks, and motion trackers. We also explore input device characteristics, how they can be classified and categorized, their internal workings, and their strengths and weaknesses.
Intelligent Power System
Authors: Vale Zita A.
Published: March 2009

Artificial intelligence has been used to address a wide range of problems in power systems. A large set of artificial intelligence techniques has been used for addressing several problems in power systems. Knowledge‐based systems and decision‐support systems have been applied in the power and energy industry. A wide range of technologies is used, like expert systems, machine learning and data mining, computational intelligence, and bio‐inspired computing, planning, and multi agent systems.

Currently Al‐based applications are used daily in power system planning and operation, as well as in electrigity market‐related activities. With secure steps, these applications are contributing towards the future implementation of the concept of an intelligent power system.

This article is intended to offer an undated overview of the application of artificial intelligence in power systems. It is organized in a way so that readers can easily understand the problems and the adequacy of the proposed solutions. Because of space constraints, this approach can be neither complete nor sufficiently deep to satisfy all readers' needs. As this is a multidisciplinary area able to attract both software and computer engineering and power system people, this article to give an insight in to most important concepts involved in these applications. Complementary material can be found in the reference list, providing deeper and more specific approaches.
Microcomputers
Authors: Stachniak Zbigniew
Published: March 2009

This article is a historical survey that covers the first two and a half decades of microcomputing.
Model Checking
Authors: Peled Doron , Pelliccione Patrizio , Spoletini Paola
Published: March 2009

Model checking is an automatic technique for verifying models of software or hardware systems against their specification. This analysis is based on an exploration of the checked system's state space, hence, it is in general affected by the state explosion problem. In this article, we present the classic model checking approaches and different techniques to deal with the complexity problem. We also describe some popular model checking systems.
Object‐Oriented Analysis and Design
Authors: Cooper Kendra M. L.
Published: March 2009

Software engineering has established activities used in developing systems, which include requirements engineering, analyzing and designing the software, implementing, testing, and so on. Object‐oriented design has been evolving as a discipline for over 25 years and is now a set of established activities in software engineering. The object‐oriented design activities transform the requirements into multiple levels of design (architecture, analysis, and detailed). The detailed design is then realized in code. This article provides an overview of two design activities: analysis and detailed design.
Parallel Programming Tools
Authors: Evans Jeffrey J.
Published: March 2009

High performance computing (HPC) hardware has evolved from (but not eliminated) vector supercomputer platforms to PC cluster and other scalable parallel systems. This architectural change is exciting because large‐scale parallelism can be more easily realized and expanded as hardware component performance evolves and component costs decrease. Moreover, the notion of large scale has grown from describing hundreds to now meaning up to hundreds of thousands of processors. This evolution also implies that hardware and software interactions have grown in number and complexity, which dramatically increased debugging and performance tuning problems for parallel application developers.

Today's HPC systems are also exposing natural tensions between the operations and user domains. Complex hardware and systems software interactions are often dependent on subtle timing conditions that can be difficult and time consuming to reproduce. Add to this one or more parallel applications that simultaneously execute on a HPC system it becomes clear that locating and eliminating undesired interactions or software bugs can be extraordinarily tedious, and it may also require expertise from across domains that have different interests and objectives. In these situations, system administrators may tend to suspect the parallel application, whereas the application developer often suspects some performance degradation of the underlying system.

This article discusses key perspectives for parallel programming tools:basics, which includes a classification of tool types,challenges and opportunitiesfor parallel programming tools,libraries, like NetLib, PetSc, and PAPI, andperformance analysis environments, including Jumpshot, Pablo, Tau, and Paradyn. Because the trend over the past 5 years has been toward clusters the discussion and examples will primarily focus on the single‐program–multiple‐data (SPMD) parallel programming model using message passing to exchange data and provide program synchronization.
Program Interpreters
Authors: Alfonseca Manuel
Published: March 2009

This article summarizes the characteristics, structure, advantages, disadvantages, and applications of program interpreters. Interpreters may be used, in preference to compilers, for portability or security reasons, for the ability to use powerful dynamic constructs, or for fast building of easy‐to‐debug prototypes. It must be taken into account, however, that interpreters and compilers have converged: Current interpreters use many optimization techniques originally developed for compilers, whereas some compilers reach typical advantages of interpreters through the use of sophisticated techniques.
Hardware Based Rapid Prototyping
Authors: Glesner Manfred , Murgan Tudor , Hollstein Thomas
Published: March 2009

The development of complex microelectronic systems confronts the design teams with a large variety of problems. Looking at the overall design time, validation requires in general significantly more than 50% of the resources. Furthermore, the composition of the design teams have noticeably changed: Although at the beginning of the 1990s, about one third of the design team was involved in validation issues, one decade later already over two thirds of the team was dealing with these issues. Two fundamental trends are observed in the VLSI community that contribute to the continuous increase of this effect in the future. On one hand, increasing system complexity because of tremendous advances in integration technology, and on the other hand, tighter time‐to‐market constraints.
Real‐Time Systems: An Introduction and the State‐of‐the‐Art
Authors: Kavi Krishna , Akl Robert , Hurson Ali
Published: March 2009

Real‐time systemscover a broad spectrum of automated platforms in which the correctness of the system not only requires functionally (or logical) correct operation but also produces results within prespecified “real‐time constraints.” By contrast, anon–real‐time systemis one for which there is no deadline, even if fast response or high performance is desired or even preferred. Real‐time systems are usually “situated” in an environment and involve in sensing apparatus to detect, control, and adapt to the environmental conditions. Real‐time systems can be networked and distributed (e.g., sensor networks) or embedded (e.g., automotive control systems, cell phones).
Side Effects
Authors: Sabry Amr
Published: March 2009

Side effects occur when a computation performs some actions “behind the scene.” Such actions complicate programming activities and the process of maintaining and reasoning about program components. To address these complications, it is first beneficial to expose the side effects as explicit actions whose propagation then can be checked explicitly and enforced by programs and program analysis tools. Additionally, side effects could be confined to specialized sublanguages, which have been designed to deal generically, and in a modular way, with a heterogeneous collection of side effects. Such specialized languages simplify—but do not completely solve—the tricky problems that occur when different side effects interact.
Software Configuration Management
Authors: Nguyen Tien N.
Published: March 2009

Software development is a dynamic process in which engineers constantly modify and refine their systems. Fundamental sources of change are usually associated with error correction, adaptations required to accommodate changes to external environments, and changes caused by changing requirements, design, or extensions of system functionality. Confusion among software engineers will develop when changes are not analyzed before they are made, recorded before they are implemented, reported to those with a need to know or controlled in a manner that will improve quality and reduce error. The discipline of identifying, organizing, and controlling modifications to a software system is called software configuration management (SCM). The ultimate goal of SCM is to maximize productivity by minimizing mistakes and to maintain software integrity, traceability, and accountability. This article summarizes the state of the art in both research and practice, as well as the well‐established and advanced technologies in the area of SCM.
Software Metrics
Authors: Sinha Avik , Yilmaz Cemal
Published: March 2009

Software metric is a generalized term used to express a measure that assesses some property of a software product, a software development process, or some artifact produced during a software development process. Measurement and experimentation have been the basis for studies in almost all scientific disciplines. The importance of measurement can be underlined by the oftea‐quoted statement from Lord Kelvin

When you can measure what you are speaking about, and express it in numbers, you know something about it; but when you cannot measure it, when you cannot express it in numbers, your knowledge of it is of a meager and unsatisfactory kind; it may be the beginning of knowledge, but you have scarcely, in your thoughts, advanced it to the stage of science.

‐Sir William Thompson, Lord Kelvin (1824–1907)
Spreadsheet Programming
Authors: Abraham Robin , Burnett Margaret , Erwig Martin
Published: March 2009

Spreadsheets are among the most widely used programming systems in the world. Individuals and businesses use spreadsheets for a wide variety of applications, ranging from performing simple calculations to building complex financial models. In this article, we first discuss how spreadsheet programs are actually functional programs. We then describe concepts in spreadsheet programming, followed by a brief history of spreadsheet systems. Widespread use of spreadsheets, coupled with their high error‐proneness and the impact of spreadsheet errors, has motivated research into techniques aimed at the prevention, detection, and correction of errors in spreadsheets. We present an overview of research effort that seeks to rectify this problem.
Women in Computing
Authors: Gürer Denise , Light Jennifer , Björkman Christina , Davies Rhian , Hancock Mark , Condon Anne , Craig Annemieke , Galpin Vashti , Martin Ursula , Pohl Margit , Wiltner Sylvia , Suriya M. , Spertus Ellen , Cohoon J. McGrath , Townsend Gloria Childress , Gabbert Paula
Published: March 2009

The history of computer science is composed mainly of male achievements and involvements, even though women have played substantial roles. Although women are a significant part of computing history, the numbers of women in computing still have yet to reach parity with men. This article covers women's experiences and impact in the computing history of the United States and in several other nations and explores some of the reasons for the disparities between the number of men and women in this field.
Managing and Mining Multimedia Data, Animations and Annotations
Authors: Thuraisingham Bhavani , Prabhakaran B. , Khan Latifur , Wang Lei
Published: March 2009

Several advances have been made on managing multimedia data stores. We now have products for multimedia data management. This article provides an overview of managing multimedia databases and describes techniques for managing multimedia animations and annotations as well as mining multimedia data.
Human–Computer Interaction
Authors: Cooperstock Jeremy R.
Published: March 2009

Human–computer interaction (HCI) is a discipline concerned with the design, evaluation, and implementation of interactive computing systems for human use. The field formally emerged out of computer science, cognitive psychology, and industrial design through the 1960s, formulating guidelines for the development of interactive computer systems, highlighting usability concerns, and providing the impetus for improved interfaces. Computing devices are becoming more prevalent and integrated into both our social and work spaces, and in some cases, they are already essential elements of these environments. HCI therefore plays an increasingly important role in ensuring that computer systems are not only functional but also respect the needs and capabilities of the humans that use them.
Program Compilers
Authors: Sloane Anthony M.
Published: March 2009

Program compilers implement translations from the high‐level language world of programmers to the low‐level world of hardware. A compiler reads program text written in a source language and translates it into an equivalent program written in a different target language. A standard pipeline architecture for compiler construction consists of lexical analysis, syntax analysis, semantic analysis, translation, and code generation phases, with optional optimization phases interspersed. Support for the phases is provided by a symbol table containing the properties of program entities. Some compiler phases can be automatically generated from formal specifications.
Video Databases
Authors: Qing Li , Xiao Wu , Chong‐Wah Ngo
Published: March 2009

As video data is widely used over the Internet, how to manage video efficiently is a challenging problem to many researchers. In this article, we examine various issues and techniques applicable to video databases (VDBs). In particular, we start with examining VDB low‐level features, which include feature extraction, similarity measures, and video indexing. We then study the conceptual level facilities embodied by data models and query languages.
Digital Arithmetic
Authors: de Dinechin Florent , Ercegovac Miloš D. , Muller Jean‐Michel , Revol Nathalie
Published: March 2009

Digital arithmetic includes all aspects of the specification, analysis, and implementation of arithmetic operations (±, ×, ÷,, etc.) in digital systems such as general‐purpose processors, digital signal processors, graphics, and various embedded systems. These aspects include number systems, arithmetic algorithms, hardware implementation of arithmetic operators (adders, multipliers, dividers), elementary function implementation, and floating‐point arithmetic. The implementors of arithmetic units and systems must compromise between various objectives: speed, area (cost), power consumption, accuracy, reusability… hence, no “best solutions” exist in general, but solutions that can be significantly different depending on whether you are designing a circuit for a cellular phone or for a supercomputer.
3‐DPoint Correspondence and Registration
Authors: Liu Yonghuai
Published: March 2009

Establishing point correspondences between overlapping data sets is a fundamental yet challenging problem in the machine vision and pattern recognition literature. In this article, the reason the traditional closest point criterion has become a standard approach for establishing possible point correspondences between overlapping range images and why three‐dimension point correspondence and registration is challenging are first discussed. Then the classic quaternion method with and without taking the reliabilities of given point correspondences into account for camera motion estimation is outlined. To establish the possible point correspondences between overlapping range images, the improved version, SoftICP, of the SoftAssign algorithm is outlined. To gain an idea of the performance of the SoftICP algorithm, some experimental results based on both synthetic data and real range images have been presented. Although the SoftICP algorithm focuses on pairwise overlapping range image registration, some techniques for efficient point correspondence establishment and multiview range image registration are also outlined. Finally, some concluding remarks are made.
Document Image Analysis and Recognition
Authors: Manmatha R.
Published: March 2009

Paper archives need to be converted to electronic form to enable the search and organization of documents. This article provides a brief introduction to the basic ideas and the remaining challenges. Essentially, this involves first scanning the image, then discovering the page layout to separate text segments and finally recognizing characters and words. The basics of scanning, image preprocessing steps, page segmentation and recognition are described for printed documents followed by a brief discussion of large vocabulary handwriting recognition. Other issues discussed include the detection of text against image backgrounds, language identification and datasets and evaluation. Modern good quality documents with printed fonts can be well recognized but poorer quality print recognition as well as handwriting recognition still remain major research challenges.
Robotic Tactile Sensors
Authors: Ohka Masahiro
Published: March 2009

In robotics, tactile sensation is also important to perform manipulation, especially in recent robotic research related to cooperative work between robots and human beings, where tactile sensation is required to prevent accidental contact. So far, various tactile sensors have been developed based on several physical phenomena, such as the piezoelectric effect, the resistance variation of conductive rubber, magnetic variation, and the optical effect. Since every tactile sensor has both merits and demerits, realizing tactile sensors for general use would have remained very difficult. In the last decade, advanced tactile sensors for limited use have appeared gradually, such as new MEMS‐based tactile sensors, PVDF tactile sensors, a stick‐slip tactile sensor, a human mimetic tactile sensor, a wireless tactile sensor, an advanced conductive rubber type tactile sensor, and image data‐based tactile sensors. As work on these tactile sensors advances, future combined designs will probably compensate for their current respective demerits. Cooperative interaction between robots and human beings will be a common situation. Since tactile sensation is required to prevent accidental contact between them in humanoid robotics, the importance of tactile sensors will continue to increase.
Quantum Computing
Authors: Gruska Jozef
Published: March 2009

This article presents very basic concepts concerning quantum information processing and deals with the main areas of quantum computation: quantum algorithms, quantum automata, quantum computational complexity, and quantum error‐correcting codes.
Distance Education in Computer Science
Authors: Pullen J. Mark , McDaniel J. Goodlett
Published: March 2009

The Southern Association of Colleges and Schools defines distance education (DE) as a “formal educational process in which most of course instruction (51% or more of instruction and interaction among students and faculty, as measured by contact hours) occurs when students and instructors are not in the same location. Instruction may be synchronous or asynchronous, including mixed delivery formats”. Distance education extends access to students who trade off the ability to participate in a traditional classroom setting against time saved by not commuting to class. DE is especially appealing to students who need a long time to travel to class, whether that is because of long distances in sparsely settled areas or because of traffic congestion in densely urban areas. Because of their high familiarity with computers and the fact that most information in the disciplines already exists in automated form, students in computer science and computer engineering find themselves among the “early adopters” of DE. The technologies and methods involved are broadly applicable, so they form an interesting application study in these disciplines as well as an important emerging mode of technical education.
Computing Pre‐University: Primary Computing Education
Authors: Bell Tim , Bianco Giovanni M.
Published: March 2009

This article focuses on computing education for students at the K–8 grade range, when students are not only learning the skills they will need in their careers, but forming opinions and attitudes that will influence what their career choices will be.
Structure–Property Relationship of Pyridine‐Containing Triphenyl Benzene Electron‐Transport Materials for Highly Efficient Blue Phosphorescent OLEDs
Authors: Su Shi‐Jian , Takahashi Yasuyuki , Chiba Takayuki , Takeda Takashi , Kido Junji
Published: March 2009

Three triphenyl benzene derivatives of 1,3,5‐tri(m‐pyrid‐2‐yl‐phenyl)benzene (Tm2PyPB), 1,3,5‐tri(m‐pyrid‐3‐yl‐phenyl)benzene (Tm3PyPB) and 1,3,5‐tri(m‐pyrid‐4‐yl‐phenyl)benzene (Tm4PyPB), containing pyridine rings at the periphery, are developed as electron‐transport and hole/exciton‐blocking materials for iridium(III) bis(4,6‐(di‐fluorophenyl)pyridinato‐N,C2′)picolinate (FIrpic)‐based blue phosphorescent organic light‐emitting devices. Their highest occupied molecular orbital and lowest unoccupied molecular orbital (LUMO) energy levels decrease as the nitrogen atom of the pyridine ring moves from position 2 to 3 and 4; this is supported by both experimental results and density functional theory calculations, and gives improved electron‐injection and hole‐blocking properties. They exhibit a high electron mobility of 10−4–10−3 cm2 V−1 s−1 and a high triplet energy level of 2.75 eV. Confinement of FIrpic triplet excitons is strongly dependent on the nitrogen atom position of the pyridine ring. The second exponential decay component in the transient photoluminescence decays of Firpic‐doped films also decreases when the position of the nitrogen atom in the pyridine ring changes. Reduced driving voltages are obtained when the nitrogen atom position changes because of improved electron injection as a result of the reduced LUMO level, but a better carrier balance is achieved for the Tm3PyPB‐based device. An external quantum efficiency (EQE) over 93% of maximum EQE was achieved for the Tm4PyPB‐based device at an illumination‐relevant luminance of 1000 cd m−2, indicating reduced efficiency roll‐off due to better confinement of FIrpic triplet excitons by Tm4PyPB in contrast to Tm2PyPB and Tm3PyPB.
Magnetic Field‐Induced Phase Transformation in NiMnCoIn Magnetic Shape‐Memory Alloys—A New Actuation Mechanism with Large Work Output
Authors: Karaca Haluk E. , Karaman Ibrahim , Basaran Burak , Ren Yang , Chumlyakov Yuny I. , Maier Hans J.
Published: March 2009

Magnetic shape memory alloys (MSMAs) have recently been developed into a new class of functional materials that are capable of magnetic‐field‐induced actuation, mechanical sensing, magnetic refrigeration, and energy harvesting. In the present work, the magnetic &!hyphen;field‐induced martensitic phase transformation (FIPT) in Ni45Mn36.5Co5In13.5 MSMA single crystals is characterized as a new actuation mechanism with potential to result in ultra‐high actuation work outputs. The effects of the applied magnetic field on the transformation temperatures, magnetization, and superelastic response are investigated. The magnetic work output of NiMnCoIn alloys is determined to be more than 1 MJ m−3 per Tesla, which is one order of magnitude higher than that of the most well‐known MSMAs, i.e., NiMnGa alloys. In addition, the work output of NiMnCoIn alloys is orientation independent, potentially surpassing the need for single crystals, and not limited by a saturation magnetic field, as opposed to NiMnGa MSMAs. Experimental and theoretical transformation strains and magnetostress levels are determined as a function of crystal orientation. It is found that [111]‐oriented crystals can demonstrate a magnetostress level of 140 MPa T−1 with 1.2% axial strain under compression. These field‐induced stress and strain levels are significantly higher than those from existing piezoelectric and magnetostrictive actuators. A thermodynamical framework is introduced to comprehend the magnetic energy contributions during FIPT. The present work reveals that the magnetic FIPT mechanism is promising for magnetic actuation applications and provides new opportunities for applications requiring high actuation work‐outputs with relatively large actuation frequencies. One potential issue is the requirement for relatively high critical magnetic fields and field intervals (1.5–3 T) for the onset of FIPT and for reversible FIPT, respectively.
Functionalized, Swellable Hydrogel Layers as a Platform for Cell Studies
Authors: Marí‐Buyé Núria , O'Shaughnessy Shannan , Colominas Carles , Semino Carlos E. , Gleason Karen K. , Borrós Salvador
Published: March 2009

This paper reports the design, synthesis and characterization of thin films as a platform for studying the separate influences of physical and chemical cues of a matrix on the adhesion, growth and final phenotype of cells. Independent control of the physical and chemical properties of functionalized, swellable hydrogel thin films is achieved using initiated chemical vapor deposition (iCVD). The systematic variation in crosslink density is demonstrated to control the swelling ability of the iCVD hydrogel films based on 2‐hydroxyethyl methacrylate (HEMA). At the same time, the incorporation of controllable concentrations of the active ester pentafluorophenyl methacrylate (PFM) allows easy immobilization of aminated bioactive motifs, such as bioactive peptides. Initial cell culture results with human umbilical vein endothelial cells (HUVEC) indicate that the strategy of using PFM to immobilize a cell‐adhesion peptide motif onto the hydrogel layers promotes proper HUVEC growth and enhances their phenotype.
Integration of a Rib Waveguide Distributed Feedback Structure into a Light‐Emitting Polymer Field‐Effect Transistor
Authors: Gwinner Michael C. , Khodabakhsh Saghar , Song Myoung Hoon , Schweizer Heinz , Giessen Harald , Sirringhaus Henning
Published: March 2009

Ambipolar light‐emitting organic field‐effect transistors (LEFETs) possess the ability to efficiently emit light due to charge recombination in the channel. Since the emission can be made to occur far from the metal electrodes, the LEFET structure has been proposed as a potential architecture for electrically pumped organic lasers. Here, a rib waveguide distributed feedback structure consisting of tantalum pentoxide (Ta2O5) integrated within the channel of a top gate/bottom contact LEFET based on poly(9,9‐dioctylfluorene‐alt‐benzothiadiazole) (F8BT) is demonstrated. The emitted light is coupled efficiently into the resonant mode of the DFB waveguide when the recombination zone of the LEFET is placed directly above the waveguide ridge. This architecture provides strong mode confinement in two dimensions. Mode simulations are used to optimize the dielectric thickness and gate electrode material. It is shown that electrode absorption losses within the device can be eliminated and that the lasing threshold for optical pumping of the LEFET structure with all electrodes (4.5 µJ cm−2) is as low as that of reference devices without electrodes. These results enable quantitative judgement of the prospects for realizing an electrically pumped organic laser based on ambipolar LEFETs. The proposed device provides a powerful, low‐loss architecture for integrating high‐performance ambipolar organic semiconductor materials into electrically pumped lasing structures.
Elevated AF1q expression is a poor prognostic marker for adult acute myeloid leukemia patients with normal cytogenetics
Authors: Strunk Crawford J. , Platzbecker Uwe , Thiede Christian , Schaich Markus , Illmer Thomas , Kang Zizhen , Leahy Patrick , Li Chunbiao , Xie Xiuyan , Laughlin Mary J. , Lazarus Hillard M. , Gerson Stanton L. , Bunting Kevin D. , Ehninger Gerhard , Tse William
Published: March 2009

Nearly half of the patients with newly diagnosed acute myeloid leukemia have normal cytogenetics (NC‐AML) and are classified as intermediate risk, but their 5‐year overall survival (OS) ranges from 24 to 42%. Therefore, molecular biomarkers to identify poor‐risk patients are needed. Elevated AF1q expression in the absence of specific poor cytogenetics is associated with poor outcomes in pediatric patients with AML and adult patients with myelodysplastic syndrome. We examined AF1q expression in 290 patients with NC‐AML. We found that patients with low AF1q (n = 73) expression (AF1qlow) have better OS (P = 0.026), disease‐free survival (P = 0.1), and complete remission rate (P = 0.06) when compared with patients with high AF1q expression (AF1qhigh n = 217). The patients with AF1qhigh had significantly greater incidence of concurrent tyrosine kinase3 internal tandem duplication. A subgroup of the patients with AF1qhigh who received allogeneic stem cell transplantation (SCT) had a significant better relapse‐free survival when compared with patients who received chemotherapy/autologous SCT (P = 0.04). This study suggests that high AF1q expression is a poor prognostic marker for adult patients with NC‐AML.