bluuebunny/crossref_metadata_2025 huggingface dataset:
PROPAGATION CHARACTERISTICS OF MICROSTRIP LINES (MTLs) WITH DEFECTED GROUND STRUCTURE SLOTS: THEORY AND APPLICATION
Authors: LIU HAIWEN , SUN LINGLING , LI ZHENGFAN , SUN XIAOWEI
Published: March 2008

Propagation characteristics, including scattering, dispersion, and loss modeling, of some microstrip lines (MTLs) with defected ground structure (DGS) slots were investigated in this paper. A simple approach was firstly introduced to calculate the slow-wave factors (SWF) of these MTLs with DGS. Based on the above-mentioned theory, a meander MTL structure with periodic DGS slots was proposed and analyzed. The improved SWF and characteristic impedances have been demonstrated, while the bandgap performances have been proved by experimental results. Further, a type of nonuniform DGS slots, which are composed of dual-periodic photonic bandgap structures, was applied to reduce the second-order harmonics and improve the output power of a Ku-band voltage-controlled oscillator. Measurements showed that the second-order harmonics are suppressed by more than - 20 dB and the output power is improved by 3–5%.
PERTURBATION TECHNIQUES IN IRREGULAR SPLINE-TYPE SPACES
Authors: FEICHTINGER HANS G. , MOLTER URSULA , ROMERO JOSÉ LUIS
Published: March 2008

In this paper we study various perturbation techniques in the context of irregular spline-type spaces. We first present the sampling problem in this general setting and prove a general result on the possibility of perturbing sampling sets. This result can be regarded as a spline-type space analogue in the spirit of Kadec's Theorem for bandlimited functions (see Refs. 14 and 15). We further derive some quantitative estimates on the amount by which a sampling set can be perturbed, and finally prove a result on the existence of optimal perturbations (with the stability of reconstruction being the optimality criterion). Finally, the techniques developed in the earlier parts of the paper are used to study the problem of disturbing a basis for a spline-type space, in order to derive a sufficient criterion for a space generated by irregular translations to be a spline-type space.
Synthesis and evaluation of linear motion transitions
Authors: Wang Jing , Bodenheimer Bobby
Published: March 2008

This article develops methods for determining visually appealing motion transitions using linear blending. Motion transitions are segues between two sequences of animation, and are important components for generating compelling animation streams in virtual environments and computer games. Methods involving linear blending are studied because of their efficiency, computational speed, and widespread use. Two methods of transition specification are detailed, center-aligned and start-end transitions. First, we compute a set of optimal weights for an underlying cost metric used to determine the transition points. We then evaluate the optimally weighted cost metric for generalizability, appeal, and robustness through a cross-validation and user study. Next, we develop methods for computing visually appealing blend lengths for two broad categories of motion. We empirically evaluate these results through user studies. Finally, we assess the importance of these techniques by determining the minimum sensitivity of viewers to transition durations, the just noticeable difference, for both center-aligned and start-end specifications.
Real-time rendering of textures with feature curves
Authors: Parilov Evgueni , Zorin Denis
Published: March 2008

The standard bilinear interpolation on normal maps results in visual artifacts along sharp features, which are common for surfaces with creases, wrinkles, and dents. In many cases, spatially varying features, like the normals near discontinuity curves, are best represented as functions of the distance to the curve and the position along the curve. For high-quality interactive rendering at arbitrary magnifications, one needs to interpolate the distance field preserving discontinuity curves exactly.

We present a real-time, GPU-based method for distance function and distance gradient interpolation which preserves discontinuity feature curves. The feature curves are represented by a set of quadratic Bezier curves, with minimal restrictions on their intersections. We demonstrate how this technique can be used for real-time rendering of complex feature patterns and blending normal maps with procedurally defined profiles near normal discontinuities.
Gesture modeling and animation based on a probabilistic re-creation of speaker style
Authors: Neff Michael , Kipp Michael , Albrecht Irene , Seidel Hans-Peter
Published: March 2008

Animated characters that move and gesticulate appropriately with spoken text are useful in a wide range of applications. Unfortunately, this class of movement is very difficult to generate, even more so when a unique, individual movement style is required. We present a system that, with a focus on arm gestures, is capable of producing full-body gesture animation for given input text in the style of a particular performer. Our process starts with video of a person whose gesturing style we wish to animate. A tool-assisted annotation process is performed on the video, from which a statistical model of the person's particular gesturing style is built. Using this model and input text tagged with theme, rheme and focus, our generation algorithm creates a gesture script. As opposed to isolated singleton gestures, our gesture script specifies a stream of continuous gestures coordinated with speech. This script is passed to an animation system, which enhances the gesture description with additional detail. It then generates either kinematic or physically simulated motion based on this description. The system is capable of generating gesture animations for novel text that are consistent with a given performer's style, as was successfully validated in an empirical user study.
Realistic rendering of birefringency in uniaxial crystals
Authors: Weidlich Andrea , Wilkie Alexander
Published: March 2008

In this article we derive the complete set of formulas needed to generate physically plausible images of uniaxial crystals. So far no computer graphics publication contains all the formulas one needs to compute the interaction of light with such crystals in a form that is useable by a graphics application, especially if a polarization-aware rendering system is being used.

This paper contains the complete derivation of the Fresnel coefficients for birefringent transparent materials, as well as for the direction cosines of the extraordinary ray and the Mueller matrices necessary to describe polarization effects. The formulas we derive can be directly used in a ray based renderer, and we demonstrate these capabilities in test scenes.
Authority-based keyword search in databases
Authors: Hristidis Vagelis , Hwang Heasoo , Papakonstantinou Yannis
Published: March 2008

Our system applies authority-based ranking to keyword search in databases modeled as labeled graphs. Three ranking factors are used: the relevance to the query, the specificity and the importance of the result. All factors are handled using authority-flow techniques that exploit the link-structure of the data graph, in contrast to traditional Information Retrieval. We address the performance challenges in computing the authority flows in databases by using precomputation and exploiting the database schema if present. We conducted user surveys and performance experiments on multiple real and synthetic datasets, to assess the semantic meaningfulness and performance of our system.
On static and dynamic methods for condensation-based privacy-preserving data mining
Authors: Aggarwal Charu C. , Yu Philip S.
Published: March 2008

In recent years, privacy-preserving data mining has become an important problem because of the large amount of personal data which is tracked by many business applications. In many cases, users are unwilling to provide personal information unless the privacy of sensitive information is guaranteed. In this paper, we propose a new framework for privacy-preserving data mining of multidimensional data. Previous work for privacy-preserving data mining uses a perturbation approach which reconstructs data distributions in order to perform the mining. Such an approach treats each dimension independently and therefore ignores the correlations between the different dimensions. In addition, it requires the development of a new distribution-based algorithm for each data mining problem, since it does not use the multidimensional records, but uses aggregate distributions of the data as input. This leads to a fundamental re-design of data mining algorithms. In this paper, we will develop a new and flexible approach for privacy-preserving data mining that does not require new problem-specific algorithms, since it maps the original data set into a new anonymized data set. These anonymized data closely match the characteristics of the original data including the correlations among the different dimensions. We will show how to extend the method to the case of data streams. We present empirical results illustrating the effectiveness of the method. We also show the efficiency of the method for data streams.
Fault-tolerance in the borealis distributed stream processing system
Authors: Balazinska Magdalena , Balakrishnan Hari , Madden Samuel R. , Stonebraker Michael
Published: March 2008

Over the past few years, Stream Processing Engines (SPEs) have emerged as a new class of software systems, enabling low latency processing of streams of data arriving at high rates. As SPEs mature and get used in monitoring applications that must continuously run (e.g., in network security monitoring), a significant challenge arises: SPEs must be able to handle various software and hardware faults that occur, masking them to provide high availability (HA). In this article, we develop, implement, and evaluate DPC (Delay, Process, and Correct), a protocol to handle crash failures of processing nodes and network failures in a distributed SPE.

Like previous approaches to HA, DPC uses replication and masks many types of node and network failures. In the presence of network partitions, the designer of any replication system faces a choice between providing availability or data consistency across the replicas. In DPC, this choice is made explicit: the user specifies an availability bound (no result should be delayed by more than a specified delay threshold even under failure if the corresponding input is available), and DPC attempts to minimize the resulting inconsistency between replicas (not all of which might have seen the input data) while meeting the given delay threshold. Although conceptually simple, the DPC protocol tolerates the occurrence of multiple simultaneous failures as well as any further failures that occur during recovery.

This article describes DPC and its implementation in the Borealis SPE. We show that DPC enables a distributed SPE to maintain low-latency processing at all times, while also achieving eventual consistency, where applications eventually receive the complete and correct output streams. Furthermore, we show that, independent of system size and failure location, it is possible to handle failures almost up-to the user-specified bound in a manner that meets the required availability without introducing any inconsistency.
Algorithms and metrics for processing multiple heterogeneous continuous queries
Authors: Sharaf Mohamed A. , Chrysanthis Panos K. , Labrinidis Alexandros , Pruhs Kirk
Published: March 2008

The emergence of monitoring applications has precipitated the need for Data Stream Management Systems (DSMSs), which constantly monitor incoming data feeds (through registered continuous queries), in order to detect events of interest. In this article, we examine the problem of how to schedule multiple Continuous Queries (CQs) in a DSMS to optimize different Quality of Service (QoS) metrics. We show that, unlike traditional online systems, scheduling policies in DSMSs that optimize for average response time will be different from policies that optimize for average slowdown, which is a more appropriate metric to use in the presence of a heterogeneous workload. Towards this, we propose policies to optimize for the average-case performance for both metrics. Additionally, we propose a hybrid scheduling policy that strikes a fine balance between performance and fairness, by looking at both the average- and worst-case performance, for both metrics. We also show how our policies can be adaptive enough to handle the inherent dynamic nature of monitoring applications. Furthermore, we discuss how our policies can be efficiently implemented and extended to exploit sharing in optimized multi-query plans and multi-stream CQs. Finally, we experimentally show using real data that our policies consistently outperform currently used ones.
A Framework for Identifying Compromised Nodes in Wireless Sensor Networks
Authors: Zhang Qing , Yu Ting , Ning Peng
Published: March 2008

Sensor networks are often subject to physical attacks. Once a node's cryptographic key is compromised, an attacker may completely impersonate it and introduce arbitrary false information into the network. Basic cryptographic mechanisms are often not effective in this situation. Most techniques to address this problem focus on detecting and tolerating false information introduced by compromised nodes. They cannot pinpoint exactly where the false information is introduced and who is responsible for it.

In this article, we propose an application-independent framework for accurately identifying compromised sensor nodes. The framework provides an appropriate abstraction of application-specific detection mechanisms and models the unique properties of sensor networks. Based on the framework, we develop alert reasoning algorithms to identify compromised nodes. The algorithm assumes that compromised nodes may collude at will. We show that our algorithm is optimal in the sense that it identifies the largest number of compromised nodes without introducing false positives. We evaluate the effectiveness of the designed algorithm through comprehensive experiments.
A conceptual approach to teaching induction for computer science
Authors: Polycarpou Irene , Pasztor Ana , Adjouadi Malek
Published: March 2008

In this paper, we present an approach to teaching induction that we call the "conceptual route" of teaching induction. Proofs by induction are central to the study of computer science and students come across them in many courses of their curricula. It is documented in the literature that in general students have difficulties with proofs by induction. Even though through the years some solutions were proposed to improve the situation, recent studies show that students are still having difficulties. Currently, proofs by induction take up too little of the computer science curriculum, and they are taught as a step-by-step procedure to be followed, which is not sufficient for students to gain conceptual understanding. In contrast, our approach aims at students' conceptual understanding by shifting their focus from the syntactic form of proofs by induction to their substance. The theoretical underpinning of our approach is an operationalization of the Induction Principle.
Language design and implementation using ruby and the interpreter pattern
Authors: Ortiz Ariel
Published: March 2008

In this paper, the S-expression Interpreter Framework (SIF) is presented as a tool for teaching language design and implementation. The SIF is based on the interpreter design pattern and is written in the Ruby programming language. Its core is quite small, but it can be easily extended by adding primitive procedures and special forms. The SIF can be used to demonstrate advanced language concepts (variable scopes, continuations, etc.) as well as different programming styles (functional, imperative, and object oriented).
Process improvement of peer code review and behavior analysis of its participants
Authors: WANG Yanqing , Yijun LI , Collins Michael , LIU Peijie
Published: March 2008

The software industry is urging on universities and colleges to cultivate software engineers who can write high quality programs. Peer code review (PCR) is accepted as an ideal way to maximize the learning outcome of students in writing quality code. Using this learning process, students improve their skills while scientific and efficient management removes the extra burden from instructors such as checking programs written by every student. In this paper, the previous PCR process was improved and the definitions of the relevant roles and documents were refined as well. After implementing this process in two academic years, some problems were found. By means of summarizing the email submissions by the students and also interviewing a few students, the behavior of all participants was preliminarily analyzed. With regards to the further quality assurance and high efficiency, a web-based management information system with a built-in blind review mechanism was discussed for solving the problems with process control, and also a game theory model was proposed for addressing the ethical issues in the whole PCR process.
The effects of pair-programming on individual programming skill
Authors: Braught Grant , Eby L. Martin , Wahls Tim
Published: March 2008

Previous studies have reported significant educational benefits from the use of pair-programming, in which two students program together at the same computer. Here, we report the results of a controlled study designed to measure the effects of pair-programming on the development of individual programming ability. Our findings indicate significant improvements in individual programming skill for students with lower SAT scores. Additionally, we found that all students are more likely to complete the course successfully when using pair-programming.
Problem solving in community
Authors: Pulimood Sarah Monisha , Wolz Ursula
Published: March 2008

Supporting a workforce that can create, not simply consume, computing technology requires a shift in pedagogy toward problem solving in a gender neutral, culturally and ethnically diverse community. It requires an authentic learning environment in which students solve real problems as a collaborative community with their peers from other disciplines. We report on three pedagogical approaches, namely student selected projects in a CS course, a multidisciplinary project-based course, and courses that partner across disciplines that provide on-demand content.
Games
Authors: Haller Susan , Ladd Brian , Leutenegger Scott , Nordlinger John , Paul Jody , Walker Henry , Zander Carol
Published: March 2008

In this special session we present arguments for and against a game-centric computing curriculum. To highlight the issues and ensure equal time for arguments on either side, our session is staged as a debate with three speakers on each side. Our audience is educators and educational researchers interested in the role of game development in the CS curriculum.
From sockets and RMI to web services
Authors: Holliday Mark A. , Houston J. Traynham , Jones E. Matthew
Published: March 2008

Traditional coverage of network programming techniques in a computer networking course addresses sockets, remote procedure call, and object-oriented remote procedure call. We propose two innovations to that coverage. The first is to emphasize the historical development of those techniques as a sequence with each technique evolving from the previous one. The second innovation is to extend the historical development and the techniques to the important current technique of web services.
Undergraduate data communications and networking projects using opnet and wireshark software
Authors: Hnatyshin Vasil Y. , Lobo Andrea F.
Published: March 2008

The national importance of creating "content reflecting cutting edge developments in STEM fields" has been recognized the National Science Foundation. The National Research Council has also noted that creating engaging laboratory and classroom experiences is a challenge to effective undergraduate education in STEM disciplines. In this paper we present our endeavors to address these issues in the field of computer networks. We discuss our experiences with novel laboratory and classroom projects using OPNET and Wireshark software products in undergraduate networking courses. These laboratories help undergraduate students understand fundamental networking concepts through modeling and simulation of computing systems. We have found that their use enhances student learning and interest in the subject of computer networks.
Game-themed programming assignments
Authors: Sung Kelvin , Panitz Michael , Wallace Scott , Anderson Ruth , Nordlinger John
Published: March 2008

We have designed and implemented game-themed programming assignment modules targeted specifically for adoption in existing introductory programming classes. These assignments are self-contained, so that faculty members with no background in graphics or gaming can selectively pick and choose a subset to combine with their own assignments in existing classes. This paper begins with a survey of previous results. Based on this survey, the paper summarizes the important considerations when designing materials for elective adoption. The paper then describes our design, implementation, and assessment efforts. Our result is a road map that guides faculty members in experimenting with game-themed programming assignments by incrementally adopting/customizing suitable materials for their classes.
Teaching cryptography with open-source software
Authors: McAndrew Alasdair
Published: March 2008

Cryptography has become an important topic in undergraduate curricula in mathematics and computer science, not just for its intrinsic interest---``about the most fun you can have with mathematics''\cite{ferg04, but for its current standing as the basis for almost all computer security. From wireless networking to secure email to password protection, cryptographic methods are used to secure information, to protect users, and to protect data.

At Victoria University, cryptography has been taught as part of a mathematics and computer science degree for several years. The students all have had at least a year of tertiary mathematics, and some exposure to a computer algebra system (Maple). However, the cost of Maple, and the current licensing agreement, means that students are unable to experiment with the software away from the computer laboratories at the University. For this reason we have decided to investigate the use of open-source computer algebra systems Maxima and Axiom. Although not as full-featured and powerful as the commercial systems Maple and Mathematica, we show they are in fact admirably suited for a subject such as cryptography. In some ways Maxima and Axiom even surpass Maple and Mathematica. Student response to the introduction of these systems has been very positive.
Student understanding of object-oriented programming as expressed in concept maps
Authors: Sanders Kate , Boustedt Jonas , Eckerdal Anna , McCartney Robert , Moström Jan Erik , Thomas Lynda , Zander Carol
Published: March 2008

In this paper, we present the results of an experiment in which we sought to elicit students' understanding of object-oriented (OO) concepts using concept maps. Our analysis confirmed earlier research indicating that students do not have a firm grasp on the distinction between "class" and "instance." Unlike earlier research, we found that our students generally connect classes with both data and behavior. Students rarely included any mention of the hardware/software context of programs, their users, or their real-world domains. Students do mention inheritance, but not encapsulation or abstraction. And the picture they draw of OO is a static one: we found nothing that could be construed as referring to interaction among objects in a program. We then discuss the implications for teaching introductory OO programming.
Increasing diversity in k-12 computer science
Authors: Goode Joanna
Published: March 2008

In this paper, I describe features of computer science programs which have successfully attracted underrepresented students to study CS. Drawing from my own teaching experiences, research, and teacher education work; I provide strategies which have diversified K-12 CS courses. The paper also points out how many of these features rely on committed partnerships between schools, school districts, universities, and the CS industry.
Grid computing at the undergraduate level
Authors: Ma he Jens , Apon Amy , Feilhauer Thomas , Wilkinson Barry
Published: March 2008

In 2003, MIT Technology Review listed Grid computing as one of 'Ten Emerging Technologies That Will Change the World' [5]. Five years later, is Grid computing ready for the undergraduate classroom? In this panel, a group of educators share their experiences in teaching Grid computing over the past several years and in various settings, and discuss how the subject materials should be developed for the future. Key points under discussion include the place in the undergraduate curriculum, the role of programming exercises, bottom-up versus top-down approaches, and the necessary Grid computing platform. This panel will be of interest to those who teach the subject, and those who wish to introduce Grid computing into their programs. It will also interest those who do not want to offer a full Grid computing course but may wish to introduce Grid computing into existing distributed systems, networking, or parallel programming courses.
Will they stay or will they go?
Authors: Cohoon J. McGrath , Wu Zhen , Luo Luo
Published: March 2008

The research reported here confirms and deepens our understanding of factors that affect women's confidence in their ability to complete a computer science or computer engineering (CSE) doctoral degree. Analysis of data from a longitudinal study of women participating in the Computing Research Association's Graduate Cohort for Women identifies the conditions or experiences that women perceive as influential. More importantly, we found that women who are not confident in their ability to complete their programs are about four times more likely to think about leaving CSE than those who begin confidently.
Security education
Authors: Taylor Carol , Shumba Rose
Published: March 2008

The topic of this proposed special session is security education with an emphasis on increasing the number of schools and programs that teach it. We will review the current status of security education as it is taught within the CS discipline including funding, curriculum standards and government programs. We will also address misconceptions people may have regarding teaching security and how these views hinder the development of programs and curriculum. Another area we cover which we feel is critical to increasing participation in security education is resources for teaching security including existing curriculum, expert assistance from Centers of Excellence schools and other resources. The format of the session will consist of both presentation periods with at least half the session devoted to participant question and answer. Session participants will be encouraged to share experiences and common concerns to the benefit of everyone attending.
State-Dependent Changes in Glutamate, Glycine, GABA, and Dopamine Levels in Cat Lumbar Spinal Cord
Authors: Taepavarapruk N. , Taepavarapruk P. , John J. , Lai Y. Y. , Siegel J. M. , Phillips A. G. , McErlane S. A. , Soja P. J.
Published: March 2008

Recent studies have indicated that the glycine receptor antagonist strychnine and the γ-aminobutyric acid type A (GABAA) receptor antagonist bicuculline reduced the rapid-eye-movement (REM) sleep-specific inhibition of sensory inflow via the dorsal spinocerebellar tract (DSCT). These findings imply that the spinal release of glycine and GABA may be due directly to the REM sleep-specific activation of reticulospinal neurons and/or glutamate-activated last-order spinal interneurons. This study used in vivo microdialysis and high-performance liquid chromatography analysis techniques to provide evidence for these possibilities. Microdialysis probes were stereotaxically positioned in the L3 spinal cord gray matter corresponding to sites where maximal cerebellar-evoked field potentials or individual DSCT and nearby spinoreticular tract (SRT) neurons could be recorded. Glutamate, glycine, and GABA levels significantly increased during REM sleep by approximately 48, 48, and 14%, respectively, compared with the control state of wakefulness. In contrast, dopamine levels significantly decreased by about 28% during REM sleep compared with wakefulness. During the state of wakefulness, electrical stimulation of the nucleus reticularis gigantocellularis (NRGc) at intensities sufficient to inhibit DSCT neuron activity, also significantly increased glutamate and glycine levels by about 69 and 45%, respectively, but not GABA or dopamine levels. We suggest that the reciprocal changes in the release of glutamate, glycine, and GABA versus dopamine during REM sleep contribute to the reduction of sensory inflow to higher brain centers via the DSCT and nearby SRT during this behavioral state. The neural pathways involved in this process likely include reticulo- and diencephalospinal and spinal interneurons.
Effect of Compatibilizers on the Morphological Properties of ABS and LCP Blends
Authors: Das T. , Pal K. , Adhikari B. , Das C. K.
Published: March 2008

The blends of acrylonitrile butadiene styrene (ABS) polymer and liquid crystalline polymer (LCP) were prepared using a melt-blending technique in presence and absence of different types of nanosilica. The effect ofZn++coated nanosilica on thermal, dynamic mechanical, and morphological properties of ABS/LCP blends was studied. TheZn++coated nanosilica showed a significant effect on the above-mentioned properties of ABS/LCP blends by reacting at the interface between ABS and LCP. A substantial improvement in storage modulus of ABS/LCP blends was observed in presence ofZn++coated nanosilica. Epoxy encapsulated nanosilica was also used as a compatibilizer in this blend system. It is known that the epoxy end group reacts with the LCP reacting groups. But in this case, we cannot find desirable results, may be due to the presence of ABS as the matrix. So Zn-ion-coated nanosilica proved to be better than that epoxy encapsulated nanosilica for the ABS/LCP containing blends. The SEM morphology also corroborates the above-mentioned argument.
Comparison of Single-Stage and Staged Progression Models for HIV/AIDS Transmission
Authors: Baryarama F. , Mugisha J. Y. T.
Published: March 2008

A single-staged (SS) model and a staged progression (SP) model for HIV/AIDS with the same variable contact rate over time were formulated. In both models, analytical expressions for the HIV prevalence were obtained. A comparison of the two models was undertaken. It is shown that prevalence projections from the SS model are lower than projections from the SP model up to and beyond the peak prevalence, although the SS model prevalence may be higher than that of the SP model much later in the epidemic. A switch from faster SP model prevalence changes to faster SS prevalence changes occurs beyond the SP model peak prevalence. Hence using the SS model underestimates HIV prevalence in the early stages of the epidemic but may overestimate prevalence in the declining HIV prevalence phase. Our comparison suggests that the SP model provides better prevalence projections than the SS model. Moreover, the extra parameters that would make the SP model appear difficult to implement may not be sought from national survey data but from existing HIV/AIDS literature.
Cesàro Statistical Core of Complex Number Sequences
Authors: Alotaibi Abdullah M.
Published: March 2008

We establish some core inequalities for complex bounded sequences using the concept of statistical(C,1)summability.
Synthesis and Characterization of Ceramic Nanoparticles System Based on Anatase-Doped Hematite
Authors: Sorescu Monica , Diamandescu L. , Sanns A. , Proch D. , Wood J. , Teodorescu V. S.
Published: March 2008

ThexTiO2-(1−x)α-Fe2O3ceramic nanoparticles system has been obtained by mechanochemical activation forx= 0.1 and 0.5 and for ball milling times ranging from 2 to 12 hours. Structural and morphological characteristics of the anatase-doped hematite system were investigated by X-ray diffraction (XRD), Mössbauer spectroscopy, and transmission electron microscopy (TEM) combined with electron diffraction (ED). In the XRD patterns, we could evidence the dissolution of anatase in hematite, more pronounced forx= 0.1. The Rietveld structure of the XRD patterns yielded the dependence of the particle size and lattice constants on the amountxof Ti substitutions and as function of the ball milling time. Forx= 0.1, we observed line broadening of the Mössbauer resonances and corresponding fit with several subspectra. Forx= 0.5, it can be observed that the central doublet corresponding to superparamagnetic particles becomes more prominent. The ball milling route allowed us to reach nanometric particle dimensions, which would make the materials very promising for catalytic and gas sensing applications.
Generalized Persistency of Excitation
Authors: Nikitin Sergey
Published: March 2008

The paper presents the generalized persistency of excitation conditions. Not only they are valid for much broader range of applications than their classical counterparts but also they elegantly prove the validity of the latter. The novelty and the significance of the approach presented in this publication is due to employing the time averaging technique.
Spectrum of a Differential Operator with Periodic Generalized Potential
Authors: Sahin Mehmet , Manafov Manaf Dzh.
Published: March 2008

We study some spectral problems for a second-order differential operator with periodic potential. Notice that the given potential is a sum of zero- and first-order generalized functions. It is shown that the spectrum of the investigated operator consists of infinite number of gaps whose length limit unlike the classic case tends to nonzero constant in some place and to infinity in other place.
Behavior of the Trinomial ArcsB(n,k,r)when0<α<1
Authors: Uahabi Kaoutar Lamrini , Zaoui Mohammed
Published: March 2008

We deal with the familyB(n,k,r)of trinomial arcs defined as the set of roots of the trinomial equationzn=αzk+(1−α), wherez=ρeiθis a complex number,nandkare two integers such that0<k<n, andαis a real number between0and1. These arcsB(n,k,r)are continuous arcs inside the unit disk, expressed in polar coordinates(ρ,θ). The question is to prove thatρ(θ)is a decreasing function, for each trinomial arcB(n,k,r).
Antirandom Testing: A Distance‐Based Approach
Authors: Wu ShenHui , Jandhyala Sridhar , Malaiya Yashwant K. , Jayasumana Anura P.
Published: March 2008

Random testing requires each test to be selected randomly regardless of the tests previously applied. This paper introduces the concept of antirandom testing where each test applied is chosen such that its total distance from all previous tests is maximum. This spans the test vector space to the maximum extent possible for a given number of vectors. An algorithm for generating antirandom tests is presented. Compared with traditional pseudorandom testing, antirandom testing is found to be very effective when a high‐fault coverage needs to be achieved with a limited number of test vectors. The superiority of the new approach is even more significant for testing bridging faults.
PPAR Agonists and Cardiovascular Disease in Diabetes
Authors: Calkin Anna C. , Thomas Merlin C.
Published: March 2008

Peroxisome proliferators activated receptors (PPARs) are ligand‐activated nuclear transcription factors that play important roles in lipid and glucose homeostasis. To the extent that PPAR agonists improve diabetic dyslipidaemia and insulin resistance, these agents have been considered to reduce cardiovascular risk. However, data from murine models suggests that PPAR agonists also have independent anti‐atherosclerotic actions, including the suppression of vascular inflammation, oxidative stress, and activation of the renin angiotensin system. Many of these potentially anti‐atherosclerotic effects are thought to be mediated by transrepression of nuclear factor‐kB, STAT, and activator protein‐1 dependent pathways. In recent clinical trials, PPARα agonists have been shown to be effective in the primary prevention of cardiovascular events, while their cardiovascular benefit in patients with established cardiovascular disease remains equivocal. However, the use of
PPARγ agonists, and more recently dual PPARα/γ coagonists, has been associated with an excess in cardiovascular events,
possibly reflecting unrecognised fluid retention with potent agonists of the
PPARγ receptor. Newer pan agonists, which retain their anti‐atherosclerotic activity without weight gain, may provide one solution to this problem. However, the complex biologic effects of the PPARs may mean that only vascular targeted agents or pure transrepressors will realise the goal of preventing atherosclerotic vascular disease.
Texture and Mechanical Anisotropy of Ultrafine-Grained Aluminum Alloy AA6016 Produced by Accumulative Roll Bonding
Authors: Skrotzki Werner , Hünsche Ingwar , Hüttenrauch Juliane , Oertel C.-G. , Brokmeier Heinz-Günter , Höppel Heinz Werner , Topic Irena
Published: March 2008

The texture of ultrafine-grained Al alloy AA6016 produced by accumulative roll bonding (ARB) has been measured by neutron diffraction. The starting texture consists of a strong cube component. During ARB, this texture breaks down and a texture typical for rolling of face-centered cubic metals with high stacking fault energy develops. The texture after 8 ARB cycles is characterised by the β-fiber with the Cu component dominating. Moreover, the rotated cube component is formed. This component is typical for simple shear, which takes place during rolling on the surfaces of the sheets. Based on the Taylor factor and calculated Lankford parameter, the mechanical anisotropy of the advanced metal sheets is discussed.
Characterization of an Implicitly Resistively‐Loaded Monopole Antenna in Lossy Liquid Media
Authors: Fox Colleen J. , Meaney Paul M. , Shubitidze Fridon , Potwin Lincoln , Paulsen Keith D.
Published: March 2008

Microwave tomographic imaging of the breast for cancer detection is a topic of considerable interest because of the potential to exploit the apparent high‐dielectric property contrast between normal and malignant tissue. An important component in the realization of an imaging system is the antenna array to be used for signal transmission/detection. The monopole antenna has proven to be useful in our implementation because it can be easily and accurately modeled and can be positioned in close proximity to the imaging target with high‐element density when configured in an imaging array. Its frequency response is broadened considerably when radiating in the liquid medium that is used to couple the signals into the breast making it suitable for broadband spectral imaging. However, at higher frequencies, the beam patterns steer further away from the desired horizontal plane and can cause unwanted multipath contributions when located in close proximity to the liquid/air interface. In this paper, we have studied the behavior of these antennas and devised strategies for their effective use at higher frequencies, especially when positioned near the surface of the coupling fluid which is used. The results show that frequencies in excess of 2 GHz can be used when the antenna centers are located as close as 2 cm from the liquid surface.
Growth of ZnO Nanowires in Aqueous Solution by a Dissolution‐Growth Mechanism
Authors: Bu Shaojing , Cui Chunxiang , Wang Qingzhou , Bai Ling
Published: March 2008

A novel methodology based on the dissolution‐growth mechanism was developed to prepare ZnO nanowires films. The film morphology and structure were investigated by using field emission scanning electron microscopy, high‐resolution transmission electron microscopy and X‐ray diffraction analysis methods. The results show that the ZnO nanowires are single crystalline c‐oriented wurtzite. The ZnO rod crystals were eroded to provide the growth primitive of ZnO nanowires, which formed on top of the rod crystals when the erosion reaction got the equilibrium. The length of the resultant nanowires is rather large because the successive erosion of the rod crystals maintains the low concentration of Zn2O(OH) 2n−2 in the aqueous solution.
Validation of Infinite Impulse Response Multilayer Perceptron for Modelling Nuclear Dynamics
Authors: Cadini F. , Zio E. , Pedroni N.
Published: March 2008

Artificial neural networks are powerful algorithms for constructing nonlinear empirical models from operational data. Their use is becoming increasingly popular in the complex modeling tasks required by diagnostic, safety, and control applications in complex technologies such as those employed in the nuclear industry. In this paper, the nonlinear modeling capabilities of an infinite impulse response multilayer perceptron (IIR-MLP) for nuclear dynamics are considered in comparison to static modeling by a finite impulse response multilayer perceptron (FIR-MLP) and a conventional static MLP. The comparison is made with respect to the nonlinear dynamics of a nuclear reactor as investigated by IIR-MLP in a previous paper. The superior performance of the locally recurrent scheme is demonstrated.
Use of Recombinant Antigens for the Diagnosis of Invasive Candidiasis
Authors: Laín Ana , Elguezabal Natalia , Amutio Elena , Fernández de Larrinoa Iñigo , Moragues María Dolores , Pontón José
Published: March 2008

Invasive candidiasis is a frequent and often fatal complication in immunocompromised and critically ill patients. Unfortunately, the diagnosis of invasive candidiasis remains difficult due to the lack of specific clinical symptoms and a definitive diagnostic method. The detection of antibodies against differentCandidaantigens may help in the diagnosis. However, the methods traditionally used for the detection of antibodies have been based on crude antigenic fungal extracts, which usually show low-reproducibility and cross-reactivity problems. The development of molecular biology techniques has allowed the production of recombinant antigens which may help to solve these problems. In this review we will discuss the usefulness of recombinant antigens in the diagnosis of invasive candidiasis.
Actuator Fault Diagnosis with Robustness to Sensor Distortion
Authors: Zhang Qinghua
Published: March 2008

Actuator fault diagnosis is often studied under strong assumptions on available sensors.
Typically, it is assumed that the sensors are either fault free or sufficiently redundant. The
purpose of this paper is to present a new method for actuator fault diagnosis which is robust
to sensor distortion. It does not require sensor redundancy to compensate sensor distortion.
The essential assumption is that sensor distortions are strictly monotonous. Despite the
nonlinear and unknown nature of distortions, such sensors still provide useful information
for fault diagnosis. The robustness of the presented diagnosis method is analyzed, as well
as its ability to detect actuator faults. A numerical example is provided to illustrate its efficiency.
Activity Classification for Interactive Game Interfaces
Authors: Darby John , Li Baihua , Costen Nick
Published: March 2008

We present a technique for modeling and recognising human activity from moving light displays using hidden Markov models. We extract a small number of joint angles at each frame to form a feature vector. Continuous hidden Markov models are then trained with the resulting time series, one for each of a variety of human activity, using the Baum‐Welch algorithm. Motion classification is then attempted by evaluation of the forward variable for each model using previously unseen test data. Experimental results based on real‐world human motion capture data demonstrate the performance of the algorithm and some degree of robustness to data noise and human motion irregularity. This technique has potential applications in activity classification for gesture‐based game interfaces and character animation.
Intestinal Infarctus following Dilatation and Uterine Curettage
Authors: Ngowe N.M. , Atangana R. , Eyenga V.C. , Sosso M.A.
Published: March 2008

We present a case of intestinal infarctus through the vagina. This was a consequence of induced abortion done clandestinely. The main objective was to point out the surgical complications of uterine dilatation and curettage by means of this rare case.
Treatment for Chronic Prostatitis/ Chronic Pelvic Pain Syndrome: Levofloxacin, Doxazosin and Their Combination
Authors: Jeong Chang Wook , Lim Dae Jung , Son Hwancheol , Lee Sang Eun , Jeong Hyeon
Published: March 2008

Introduction: We performed a prospective, randomized study to examine the efficacies of levofloxacin and doxazosin alone and as a combination therapy in patients with National Institutes of Health (NIH) category III chronic prostatitis/chronic pelvic pain syndrome. Patients and Methods: Men with a NIH diagnosis of category III chronic prostatitis/chronic pelvic pain syndrome and who had experienced pelvic pain for more than 3 months during the last 6 months were enrolled. All patients underwent treatment for 6 weeks. The patients were assessed at baseline and after 2 and 6 weeks by using the NIH Chronic Prostatitis Symptom Index. Eighty-one men (average age 40.1 years) were randomized to either the levofloxacin group (n = 26), the doxazosin group (n = 26), or the combination group (n = 29). Results: The average baseline NIH Chronic Prostatitis Symptom Index total scores were 22.6, 22.4, and 24.1, respectively. At 6 weeks, the total scores were 11.2 (response rate 50.3%), 17.7 (response rate 21.1%), and 13.1 (response rate 45.6%), respectively. The levofloxacin group showed a higher response rate than the doxazosin group, not at 2 weeks but at 6 weeks (p < 0.001). Conclusions: For a 6-week short-term treatment levofloxacin is more effective than doxazosin for chronic prostatitis/chronic pelvic pain syndrome. In addition, levofloxacin monotherapy was also more effective when compared with the combination therapy.
Effect of Finasteride Treatment on Suburethral Prostatic Microvessel Density in Patients with Hematuria Related to Benign Prostate Hyperplasia
Authors: Memis Ali , Ozden Cuneyt , Ozdal Ozdem Levent , Guzel Ozer , Han Ozge , Seckin Selda
Published: March 2008

Introduction: In the present study we evaluated the effect of short-term finasteride treatment on microvessel density (MVD)which is an indicator of prostatic angiogenesis in patients with hematuria secondary to benign prostatic hyperplasia (BPH). Materials and Methods: 30 patients who were candidates for BPH surgery were prospectively included in the study. All patients had history of gross hematuria and evaluated by ultrasonography and cystoscopy. The patients were randomized two groups before surgery. The treatment group consisted of 13 patients who were given 5 mg finasteride daily for 4 weeks before surgery. The control group consisted of 17 patients who did not receive finasteride before surgery. During surgery, resected suburethral and hyperplastic prostate specimens were sent for histopathologic MVD determination separately. Results: Mean MVD in the suburethral portion of prostate was significantly lower in patients treated with finasteride when compared with controls (9.08 ± 5.6 and 13.94 ± 5.90, respectively, p < 0.05). Mean MVD for the hyperplastic portion of prostate was similar for the finasteride and control groups (14.21 ± 7.10 and 19.75 ± 9.73, respectively, p > 0.05). Conclusion: The potential role of finasteride on hematuria related to BPH may be the suppressive effect on MVDin the suburethral tissue of prostate.