Showing papers by "University of Cyprus published in 2009"

Epistemological and methodological issues for the conceptualization, development, and assessment of ICT-TPCK: Advances in technological pedagogical content knowledge (TPCK)

Abstract: In this paper, several issues regarding the epistemology of technological pedagogical content knowledge (TPCK) are first raised for the purpose of clarifying the construct. Specifically, the transformative and integrative views are juxtaposed for exploring the epistemology of TPCK, and, at the end, the transformative view is adopted concluding that TPCK is a unique body of knowledge that is constructed from the interaction of its individual contributing knowledge bases. Then, ICT-TPCK is introduced as a strand of TPCK, and is described as the ways knowledge about tools and their affordances, pedagogy, content, learners, and context are synthesized into an understanding of how particular topics that are difficult to be understood by learners or difficult to be represented by teachers can be transformed and taught more effectively with technology in ways that signify its added value. One model for the development and another for the assessment of ICT-TPCK are then discussed. Technology Mapping is proposed as a situative methodology for the development of ICT-TPCK, and three forms of assessment, namely, expert assessment, peer assessment, and self-assessment are proposed for assessing teachers' competencies to teach with technology. The paper also reports on the empirical findings of a study that was undertaken to investigate the impact of the proposed models on student learning within the context of two design tasks in a pre-service primary teacher education course. Repeated measures within-subject effects were tested and the results indicated that ICT-TPCK competency significantly improved over the course of a semester. The results of this study clearly show that the theoretical models proposed herein can positively impact the development of ICT-TPCK. Lastly, these results can be used as baseline data in future studies that may be conducted to further validate or improve the proposed models in different contexts.

Command Filtered Backstepping

Abstract: Implementation of backstepping becomes increasingly complex as the order of the system increases. This increasing complexity is mainly driven by the need to compute command derivatives at each step of the design, with the ultimate step requiring derivatives of the same order as the plant. This article addresses a modification that obviates the need to compute analytic derivatives by introducing command filters in the backstepping design. While the concept of the command filter has previously been introduced in the literature, the main contribution of this technical note is the rigorous analysis of the effect of the command filter on closed-loop stability and performance, and a proof of stability based on Tikhonov's theorem. The implementation approach includes a compensated tracking error that retains the standard stability properties of backstepping approaches.

Cloud Computing: Distributed Internet Computing for IT and Scientific Research

Abstract: Cloud computing is a disruptive technology with profound implications not only for Internet services but also for the IT sector as a whole. Its emergence promises to streamline the on-demand provisioning of software, hardware, and data as a service, achieving economies of scale in IT solutions' deployment and operation. This issue's articles tackle topics including architecture and management of cloud computing infrastructures, SaaS and IaaS applications, discovery of services and data in cloud computing infrastructures, and cross-platform interoperability. Still, several outstanding issues exist, particularly related to SLAs, security and privacy, and power efficiency. Other open issues include ownership, data transfer bottlenecks, performance unpredictability, reliability, and software licensing issues. Finally, hosted applications' business models must show a clear pathway to monetizing cloud computing. Several companies have already built Internet consumer services such as search, social networking, Web email, and online commerce that use cloud computing infrastructure. Above all, cloud computing's still unknown "killer application" will determine many of the challenges and the solutions we must develop to make this technology work in practice.

Linking Callous-Unemotional Traits to Instrumental and Non-Instrumental Forms of Aggression

Abstract: The current study investigated the relation of callous-unemotional (CU) traits to bullying, victimization, and proactive and reactive aggression. We also examined whether CU traits will be more strongly related to groups of children exhibiting combined or pure forms of proactive and reactive aggression and combined or pure forms of bullying and victimization. The findings suggested that the presence of CU traits, which consists of three dimensions of behavior, uncaring, callousness, and unemotional, may designate important subgroups of aggressive children. Evidence suggested that the adolescents characterized by higher levels of CU traits were more likely to exhibit combined proactive and reactive aggression in comparison to pure forms of proactive or reactive aggression. Additionally, bullies scored higher on the uncaring dimension, and bully-victims (adolescents exhibiting both bullying and victimization) scored higher on the callous dimension. In contrast, victims of bullying scored lower on the uncaring dimension of behavior.

Placement of Synchronized Measurements for Power System Observability

Abstract: This paper presents a method for the use of synchronized measurements for complete observability of a power system. The placement of phasor measurement units (PMUs), utilizing time-synchronized measurements of voltage and current phasors, is studied in this paper. An integer quadratic programming approach is used to minimize the total number of PMUs required, and to maximize the measurement redundancy at the power system buses. Existing conventional measurements can also be accommodated in the proposed PMU placement method. Complete observability of the system is ensured under normal operating conditions as well as under the outage of a single transmission line or a single PMU. Simulation results on the IEEE 14-bus, 30-bus, 57-bus, and 118-bus test systems as well as on a 298-bus test system are presented in this paper.

Language-teaching methodology

Abstract: There is no standard approach to teaching which every teacher should strive to adopt, but certain strategies are valuable in the classroom. Both formal and informal teaching approaches can be very effective when these principles are observed. This paper presents some of my teaching methodologies and approaches in language teaching. My methodology tools are: Mini-lecture, Interactive lecture with student active breaks, Reading, Audio?visual materials (CD ROM, videotapes, etc.) and Group discussion. My methodologies and approaches aimed to influence, motivate and inspire students to learn. Their success is my success, thus motivating me to design challenging learning environments that provide students with the best opportunity to significantly contribute to sustaining personal development.

Greening the service profit chain: the impact of environmental management practices

Abstract: This paper explores the relationship between environmental practices and performance in services and the impact of such practices on the external portion of the service profit chain. Using structural equation modeling, it tests the hypotheses developed with data from the European hospitality industry. The findings suggest that environmental practices are positively related to performance through the mediating effect of enhanced customer satisfaction and loyalty. The paper’s contributions include: the conceptual development of the relationship between environmental practices and performance in services, the incorporation of environmental practices within the service profit chain, and the testing of their impact on customer satisfaction. (CUSTOMER LOYALTY; CUSTOMER SATISFACTION; ENVIRONMENTAL MANAGEMENT PRACTICES; SERVICE PROFIT CHAIN)

The missing mechanical circuit element

Abstract: In 2008, two articles in Autosport revealed details of a new mechanical suspension component with the name "J-damper" which had entered Formula One Racing and which was delivering significant performance gains in handling and grip From its first mention in the 2007 Formula One "spy scandal" there was much speculation about what the J-damper actually was The Autosport articles revealed that the J-damper was in fact an "inerter" and that its origin lay in academic work on mechanical and electrical circuits at Cambridge University This article aims to provide an overview of the background and origin of the inerter, its application, and its intimate connection with the classical theory of network synthesis

Incremental dynamic analysis for estimating seismic performance sensitivity and uncertainty

Abstract: SUMMARY Incremental Dynamic Analysis (IDA) is presented as a powerful tool to evaluate the variability in the seismic demand and capacity of non-deterministic structural models, building upon existing methodologies of Monte Carlo simulation and approximate moment-estimation. A nine-story steel moment-resisting frame is used as a testbed, employing parameterized moment-rotation relationships with non-deterministic quadrilinear backbones for the beam plastic-hinges. The uncertain properties of the backbones include the yield moment, the post-yield hardening ratio, the end-of-hardening rotation, the slope of the descending branch, the residual moment capacity and the ultimate rotation reached. IDA is employed to accurately assess the seismic performance of the model for any combination of the parameters by performing multiple nonlinear timehistory analyses for a suite of ground motion records. Sensitivity analyses on both the IDA and the static pushover level reveal the yield moment and the two rotational-ductility parameters to be the most in∞uential for the frame behavior. To propagate the parametric uncertainty to the actual seismic performance we employ a) Monte Carlo simulation with latin hypercube sampling, b) point-estimate and c) flrst-order second-moment techniques, thus ofiering competing methods that represent difierent compromises between speed and accuracy. The flnal results provide flrm ground for challenging current assumptions in seismic guidelines on using a median-parameter model to estimate the median seismic performance and employing the well-known square-root-sum-of-squares rule to combine aleatory randomness and epistemic uncertainty. Copyright c ∞ 2009 John Wiley & Sons, Ltd.

The high-acceptance dielectron spectrometer HADES

Abstract: HADES is a versatile magnetic spectrometer aimed at studying dielectron production in pion, proton and heavy-ion-induced collisions. Its main features include a ring imaging gas Cherenkov detector for electron-hadron discrimination, a tracking system consisting of a set of 6 superconducting coils producing a toroidal field and drift chambers and a multiplicity and electron trigger array for additional electron-hadron discrimination and event characterization. A two-stage trigger system enhances events containing electrons. The physics program is focused on the investigation of hadron properties in nuclei and in the hot and dense hadronic matter. The detector system is characterized by an 85% azimuthal coverage over a polar angle interval from 18° to 85°, a single electron efficiency of 50% and a vector meson mass resolution of 2.5%. Identification of pions, kaons and protons is achieved combining time-of-flight and energy loss measurements over a large momentum range (0.1 < p < 1.0 GeV/c). This paper describes the main features and the performance of the detector system. © Societa Italiana di Fisica / Springer-Verlag 2009.

Radio-over-fiber transport for the support of wireless broadband services [Invited]

Abstract: Some of the work carried out within the EU Network of Excellence ISIS on radio-over-fiber systems for the support of current and emerging wireless networks is reviewed. Direct laser modulation and externally modulated links have been investigated, and demonstrations of single-mode fiber and multimode fiber systems are presented. The wireless networks studied range from personal area networks (such as ZigBee and ultrawideband) through wireless local area networks to wireless metropolitan area networks (WiMAX) and third-generation mobile communications systems. The performance of the radio-over-fiber transmission is referenced to the specifications of the relevant standard, protocol operation is verified, and complete network demonstrations are implemented.

Key Technologies of WDM-PON for Future Converged Optical Broadband Access Networks [Invited]

Abstract: The wavelength-division-multiplexed passive optical network (WDM-PON) is considered to be the next evolutionary solution for a simplified and future-proofed access system that can accommodate exponential traffic growth and bandwidth-hungry new applications. WDM-PON mitigates the complicated time-sharing and power budget issues in time-division-multiplexed PON (TDM-PON) by providing virtual point-to-point optical connectivity to multiple end users through a dedicated pair of wavelengths. There are a few hurdles to overcome before WDM-PON sees widespread deployment. Several key enabling technologies for converged WDM-PON systems are demonstrated, including the techniques for longer reach, higher data rate, and higher spectral efficiency. The cost-efficient architectures are designed for single-source systems and resilient protection for traffic restoration. We also develop the integrated schemes with radio-over-fiber (RoF)-based optical-wireless access systems to serve both fixed and mobile users in the converged optical platform.

Advances in teacher emotion research : the impact on teachers' lives

Abstract: to Advances in Teacher Emotion Research: The Impact on Teachers' Lives.- Teacher Emotions in the Context of Teaching and Teacher Education.- Teacher Emotions: Well Being and Effectiveness.- Seeking Eudaimonia: The Emotions in Learning to Teach and to Mentor.- Emotion Management and Display in Teaching: Some Ethical and Moral Considerations in the Era of Marketization and Commercialization.- Entering the Emotional Practices of Teaching.- Student and Teacher Involvement.- Understanding the Role of Teacher Appraisals in Shaping the Dynamics of their Relationships with Students: Deconstructing Teachers' Judgments of Disruptive Behavior/Students.- Antecedents and Effects of Teachers' Emotional Experiences: An Integrated Perspective and Empirical Test.- Teacher Transactions with the Emotional Dimensions of Student Experiences with Cancer.- Emotional Scaffolding: The Emotional and Imaginative Dimensions of Teaching and Learning.- Educational Psychology Perspectives on Teachers' Emotions.- Teachers' Emotions in Times of Change.- Surviving Diversity in Times of Performativity: Understanding Teachers' Emotional Experience of Change.- Teachers' Emotions in a Context of Reforms: To a Deeper Understanding of Teachers and Reforms.- Implementing High-Quality Educational Reform Efforts: An Interpersonal Circumplex Model Bridging Social and Personal Aspects of Teachers' Motivation.- Beliefs and Professional Identity: Critical Constructs in Examining the Impact of Reform on the Emotional Experiences of Teachers.- Race, Gender and Power Relationships.- An Exploratory Study of Race and Religion in the Emotional Experience of African-American Female Teachers.- The Emotionality of Women Professors of Color in Engineering: A Critical Race Theory and Critical Race Feminism Perspective.- Emotions and Social Inequalities: Mobilizing Emotions for Social Justice Education.- A Future Agenda for Research on Teachers' Emotions in Education.- Research on Teachers' Emotions in Education: Findings, Practical Implications and Future Agenda.

Search for new particles decaying into dijets in proton-antiproton collisions at s=1.96TeV

Abstract: We present a search for new particles whose decays produce two jets (dijets) using proton-antiproton collision data corresponding to an integrated luminosity of 1.13 fb-1 collected with the CDF II detector. The measured dijet mass spectrum is found to be consistent with next-to-leading-order perturbative QCD predictions, and no significant evidence of new particles is found. We set upper limits at the 95% confidence level on cross sections times the branching fraction for the production of new particles decaying into dijets with both jets having a rapidity magnitude |y| < 1. These limits are used to determine the mass exclusions for the excited quark, axigluon, flavor-universal coloron, E6 diquark, color-octet technirho, W', and Z'.

Transmission of Drug-Resistant HIV-1 Is Stabilizing in Europe

Abstract: The SPREAD Programme investigated prospectively the time trend from September 2002 through December 2005 of trans- mitted drug resistance (TDR) among 2793 patients in 20 European countries and in Israel with newly diagnosed human immunodeficiency virus type 1 (HIV-1) infection. The overall prevalence of TDR was 8.4% (225 of 2687 patients; 95% confidence interval [CI], 7.4%-9.5%), the prevalence of nucleoside reverse-transcriptase inhibitor (NRTI) resistance was 4.7% (125 of 2687 patients; 95% CI, 3.9%-5.5%), the prevalence of nonucleoside reverse-transcriptase inhibitor (NNRTI) resistance was 2.3% (62 of 2687 patients; 95% CI, 1.8%-2.9%), and the prevalence of protease inhibitor (PI) resistance was 2.9% (79 of 2687 patients; 95% CI, 2.4%-3.6%). There was no time trend in the overall TDR or in NRTI resistance, but there was a statistically significant decrease in PI resistance (P = .04) and in NNRTI resistance after an initial increase (P = .02). We found that TDR appears to be stabilizing in Europe, consistent with recent reports of decreasing drug resistance and improved viral sup- pression in patients treated for HIV-1 infection.

How deep is the annuity market participation puzzle

Abstract: Using UK microeconomic data, we analyze the empirical determinants of voluntary annuity market demand. We find that annuity market participation increases with financial wealth, life expectancy and education and decreases with other pension income and a possible bequest motive for surviving spouses. We then show that these empirically-motivated determinants of annuity market participation have the same, quantitatively important, effects in a life-cycle model of annuity and life insurance demand, saving and portfolio choice. Moreover, reasonable preference parameters predict annuity demand levels comparable to the data. For stockholders, a relatively strong bequest motive is sufficient to simultaneously generate balanced portfolios and low annuity demand.

Role of Wild Suids in the Epidemiology of African Swine Fever

Abstract: There is presently no vaccine to combat African swine fever (ASF), a viral hemorrhagic fever of domestic pigs that causes up to 100% morbidity and mortality in naive, commercial pig populations. In its endemic setting, ASF virus cycles between asymptomatic warthogs and soft ticks, with persistence in exotic locations being ascribed to the almost global distribution of susceptible soft tick and suid hosts. An understanding of the role played by diverse hosts in the epidemiology of this multi-host disease is crucial for effective disease control. Unlike the intensively studied Ornithodoros tick vector, the role of many wild suids remains obscure, despite growing recognition for suid-exclusive virus cycling, without the agency of the argasid tick, at some localities. Because the four wild suid genera, Phacochoerus, Potamochoerus, Hylochoerus, and Sus differ from each other in taxonomy, distribution, ecology, reservoir host potential, virus shedding, ASF symptomology, and domestic-pig contact potential, their role in disease epidemiology is also varied. This first consolidated summary of ASF epidemiology in relation to wild suids summarizes current knowledge and identifies information gaps and future research priorities crucial for formulating effective disease control strategies.

Steering electrons on moving pathways.

Abstract: Electron transfer (ET) reactions provide a nexus among chemistry, biochemistry, and physics. These reactions underpin the “power plants” and “power grids” of bioenergetics, and they challenge us to understand how evolution manipulates structure to control ET kinetics. Ball-and-stick models for the machinery of electron transfer, however, fail to capture the rich electronic and nuclear dynamics of ET molecules: these static representations disguise, for example, the range of thermally accessible molecular conformations. The influence of structural fluctuations on electron-transfer kinetics is amplified by the exponential decay of electron tunneling probabilities with distance, as well as the delicate interference among coupling pathways. Fluctuations in the surrounding medium can also switch transport between coherent and incoherent ET mechanisms − and may gate ET so that its kinetics is limited by conformational interconversion times, rather than by the intrinsic ET time scale. Moreover, preparation of a ...

Measurements get together

Abstract: This article deals with the synchronized measurement technology that has the potential of becoming the backbone for real-time monitoring system. The secure and reliable operation of modern power systems is an increasingly challenging task due to the ever-increasing demand for electricity, the growing number of interconnections, penetration of variable renewable energy sources, and deregulated energy market conditions. Power companies in different parts of the world are therefore feeling the need for a real-time wide area monitoring, protection, and control (WAMPAC) system. Synchronized measurement technology (SMT) has the potential of becoming the backbone of this system. The major advantages of using SMT are that 1) the measurements from widely dispersed locations can be synchronized with respect to a Global Positioning System (GPS) clock, 2) voltage phase angles can be measured directly, which was so far technically infeasible, and 3) the accuracy and speed of energy management system (EMS) applications increases manifold.

Hidden Liquidity: An Analysis of Order Exposure Strategies in Electronic Stock Markets

Abstract: Many stock exchanges choose to reduce market transparency by allowing traders to hide some or all of their order size. We study costs and benefits of hidden order usage for a sample of Euronext-Paris stocks, where hidden orders represent 44% of sample order volume. All else equal, hidden orders are associated with smaller opportunity costs and lower implementation shortfall costs. However, hidden orders are less likely to execute completely and exhibit longer times to execution. The presence and magnitude of hidden orders can be predicted to a significant but imperfect degree based on observable order attributes, firm characteristics and market conditions. We find that the option to hide order size is used differently by traders who submit passive versus aggressively priced orders. Specifically, aggressively priced orders tend to be exposed, to draw out potential counterparties and allow quick execution, while larger and less aggressively priced orders tend to be hidden, to reduce the option value of standing limit orders. Overall, the results indicate that the option to hide order size is valuable, in particular to patient traders without superior information on future security price movements.

Investigating the Double-Deficit Hypothesis in Greek: Findings From a Longitudinal Study

Abstract: This study examined longitudinally the double-deficit hypothesis in Greek, an orthographically consistent language, following a group of children from kindergarten to Grade 2. Four groups were formed on the basis of two composite scores of phonological and naming-speed criterion measures: a double-deficit group (DD; n = 17), a phonological deficit group (PD; n = 33), a naming deficit group (ND; n = 33), and a control group exhibiting no deficits (CnD; n = 159). The four groups were identified in Grade 1, and they were compared retrospectively in kindergarten only on the criterion measures, and in Grades 1 and 2 on measures of word-reading fluency and accuracy, orthographic processing, and passage comprehension. The effects of verbal and nonverbal ability, age, gender, and parental education were controlled among the groups. Results showed that the DD group exhibited greater dysfunction in reading and orthographic processing compared to the single-deficit and CnD groups. Also, although the three deficit groups were not easily differentiated in kindergarten, their differences were maximized in Grade 1 and retained in Grade 2. The type and severity of reading deficits found in the ND group were mostly associated with naming speed at both the word- and text-reading levels, deficits that persisted across development. The PD group showed mostly deficient orthographic and poor decoding skills that improved across development. Implications of the findings for the double-deficit hypothesis in languages with transparent orthographies are discussed.