Showing papers by "University of Cyprus published in 2007"

CMS physics technical design report, volume II: Physics performance

Abstract: CMS is a general purpose experiment, designed to study the physics of pp collisions at 14 TeV at the Large Hadron Collider (LHC). It currently involves more than 2000 physicists from more than 150 institutes and 37 countries. The LHC will provide extraordinary opportunities for particle physics based on its unprecedented collision energy and luminosity when it begins operation in 2007. The principal aim of this report is to present the strategy of CMS to explore the rich physics programme offered by the LHC. This volume demonstrates the physics capability of the CMS experiment. The prime goals of CMS are to explore physics at the TeV scale and to study the mechanism of electroweak symmetry breaking--through the discovery of the Higgs particle or otherwise. To carry out this task, CMS must be prepared to search for new particles, such as the Higgs boson or supersymmetric partners of the Standard Model particles, from the start-up of the LHC since new physics at the TeV scale may manifest itself with modest data samples of the order of a few fb−1 or less. The analysis tools that have been developed are applied to study in great detail and with all the methodology of performing an analysis on CMS data specific benchmark processes upon which to gauge the performance of CMS. These processes cover several Higgs boson decay channels, the production and decay of new particles such as Z' and supersymmetric particles, Bs production and processes in heavy ion collisions. The simulation of these benchmark processes includes subtle effects such as possible detector miscalibration and misalignment. Besides these benchmark processes, the physics reach of CMS is studied for a large number of signatures arising in the Standard Model and also in theories beyond the Standard Model for integrated luminosities ranging from 1 fb−1 to 30 fb−1. The Standard Model processes include QCD, B-physics, diffraction, detailed studies of the top quark properties, and electroweak physics topics such as the W and Z0 boson properties. The production and decay of the Higgs particle is studied for many observable decays, and the precision with which the Higgs boson properties can be derived is determined. About ten different supersymmetry benchmark points are analysed using full simulation. The CMS discovery reach is evaluated in the SUSY parameter space covering a large variety of decay signatures. Furthermore, the discovery reach for a plethora of alternative models for new physics is explored, notably extra dimensions, new vector boson high mass states, little Higgs models, technicolour and others. Methods to discriminate between models have been investigated. This report is organized as follows. Chapter 1, the Introduction, describes the context of this document. Chapters 2-6 describe examples of full analyses, with photons, electrons, muons, jets, missing ET, B-mesons and τ's, and for quarkonia in heavy ion collisions. Chapters 7-15 describe the physics reach for Standard Model processes, Higgs discovery and searches for new physics beyond the Standard Model

Crowds by Example

Abstract: We present an example-based crowd simulation technique. Most crowd simulation techniques assume that the behavior exhibited by each person in the crowd can be defined by a restricted set of rules. This assumption limits the behavioral complexity of the simulated agents. By learning from real-world examples, our autonomous agents display complex natural behaviors that are often missing in crowd simulations. Examples are created from tracked video segments of real pedestrian crowds. During a simulation, autonomous agents search for examples that closely match the situation that they are facing. Trajectories taken by real people in similar situations, are copied to the simulated agents, resulting in seemingly natural behaviors.

The Geographic Distribution of Big Five Personality Traits Patterns and Profiles of Human Self-Description Across 56 Nations

Abstract: The Big Five Inventory (BFI) is a self-report measure designed to assess the high-order personality traits of Extraversion, Agreeableness, Conscientiousness, Neuroticism, and Openness. As part of the International Sexuality Description Project, the BFI was translated from English into 28 languages and administered to 17,837 individuals from 56 nations. The resulting cross-cultural data set was used to address three main questions: Does the factor structure of the English BFI fully replicate across cultures? How valid are the BFI trait profiles of individual nations? And how are personality traits distributed throughout the world? The five-dimensional structure was robust across major regions of the world. Trait levels were related in predictable ways to self-esteem, sociosexuality, and national personality profiles. People from the geographic regions of South America and East Asia were significantly different in openness from those inhabiting other world regions. The discussion focuses on limitations of t...

Occurrence patterns of pharmaceuticals in water and wastewater environments

Abstract: The occurrence of pharmaceuticals and their metabolites and transformation products in the environment is becoming a matter of concern, because these compounds, which may have adverse effects on living organisms, are extensively and increasingly used in human and veterinary medicine and are released continuously into the environment. A variety of pharmaceuticals have been detected in many environmental samples worldwide. Their occurrence has been reported in sewage-treatment-plant effluents, surface water, seawater, groundwater, soil, sediment and fish. This paper provides an overview of recent scientific research on the sources, occurrence, and fate of pharmaceuticals in water and wastewater.

The Dynamics of Educational Effectiveness: A Contribution to Policy, Practice and Theory in Contemporary Schools

Abstract: Part 1: The Background to Educational Effectiveness Research 1. Towards the Development of the Theoretical Framework of Educational Effectiveness Research 2. Essential Characteristics of Educational Effectiveness Research 3. The Comprehensive Model of Educational Effectiveness 4. Empirical Testing of the Comprehensive Model of Educational Effectiveness: Review of Research Part 2: A Dynamic Model of Educational Effectiveness 5. The Essential Features of The Dynamic Model 6. The Dynamic Model: Factors Operating at Student and Classroom Level 7. The Dynamic Model: Factors Operating at School and Context Level Part 3: Empirical Support for the Dynamic Model of Educational Effectiveness 8. Testing the Dynamic Model: A Study Investigating the Impact of Classroom-Level Factors on Student Achievement Gains 9. Testing The Dynamic Model: A Synthesis of Studies Investigating the Impact of School Factors on Student Achievement Part 4: Implications for Research, Policy and Practice 10. Implications for Research and Evaluation 11. Implications for Policy 12. Implications for the Improvement of Educational Practice

CMS physics technical design report: Addendum on high density QCD with heavy ions

Abstract: This report presents the capabilities of the CMS experiment to explore the rich heavy-ion physics programme offered by the CERN Large Hadron Collider (LHC). The collisions of lead nuclei at energies , will probe quark and gluon matter at unprecedented values of energy density. The prime goal of this research is to study the fundamental theory of the strong interaction ? Quantum Chromodynamics (QCD) ? in extreme conditions of temperature, density and parton momentum fraction (low-x).This report covers in detail the potential of CMS to carry out a series of representative Pb-Pb measurements. These include bulk observables, (charged hadron multiplicity, low pT inclusive hadron identified spectra and elliptic flow) which provide information on the collective properties of the system, as well as perturbative probes such as quarkonia, heavy-quarks, jets and high pT hadrons which yield tomographic information of the hottest and densest phases of the reaction.

An analytical review of the factors stimulating smaller firms to export: Implications for policy‐makers

Abstract: Purpose – Although exporting can offer many benefits to smaller manufacturers, a large number of these firms refrain from export operations as a result of insufficient stimulation. This paper seeks to critically analyse and creatively synthesise the reasons that may stimulate a smaller firm to export, based on a review of 32 empirical studies conducted in various parts of the world during the period 1974‐2005.Design/methodology/approach – A total of 40 export stimuli were systematically identified from the extant empirical literature, which, for analytical purposes, were divided into internal and external, as well as proactive and reactive. Within each study, stimuli were ranked in terms of their importance, frequency, or intensity, and the aggregate impact of each stimulus in all studies under review was evaluated.Findings – The review revealed that export stimulation stems from a variety of factors, and may vary according to time, spatial, and industry contexts. Irrespective of contextual factors, there...

Key Enabling Technologies for Optical–Wireless Networks: Optical Millimeter-Wave Generation, Wavelength Reuse, and Architecture

Abstract: The integration of optical and wireless systems is considered to be one of the most promising solutions for increasing the existing capacity and mobility as well as decreasing the costs in next-generation optical access networks. In this paper, several key enabling technologies for hybrid optical-wireless access networks are described, including optical millimeter-wave (mm-wave) generation, upconversion, and transmission in a downlink direction, and full-duplex operation based on wavelength reuse by using a centralized light source in an uplink direction. By employing these enabling technologies, we design and experimentally demonstrate an optical-wireless testbed that is simultaneously delivering wired and wireless services in the integrated optical-wireless and wavelength-division-multiplexing passive-optical-network access networks. The actual applications consisting of 270-Mb/s uncompressed standard-definition TV signal and 2.5-Gb/s data channels for downstream are successfully transmitted over a 25-km fiber and a 10.2-m indoor wireless link with less than a 1.5-dB power penalty. The results show that this integrated system is a practical solution to deliver superbroadband information services to both stationary and mobile users.

Are Any Growth Theories Robust

Abstract: This paper investigates the strength of empirical evidence for various growth theories when there is model uncertainty with respect to the correct growth model. Using model averaging methods, we find little evidence that so-called fundamental growth theories play an important role in explaining aggregate growth. In contrast, we find strong evidence for macroeconomic policy effects and a role for unexplained regional heterogeneity, as well as some evidence of parameter heterogeneity in the aggregate production function. We conclude that the ability of cross-country growth regressions to adjudicate the relative importance of alternative growth theories is limited.

Comparing and combining real and virtual experimentation: an effort to enhance students' conceptual understanding of electric circuits

Abstract: The purpose of this study was to investigate value of combining Real Experimentation (RE) with Virtual Experimentation (VE) with respect to changes in students' conceptual understanding of electric circuits. To achieve this, a pre-post comparison study design was used that involved 88 undergraduate students. The participants were randomly assigned to an experimental (45 students) and a control group (43 students). Each group attended a one semester course in physics for preservice elementary school teachers. Both groups used the same inquiry-based curriculum materials. Participants in the control group used RE to conduct the study's experiments, whereas, participants in the experimental group used RE in the first part of the curriculum and VE in another part. Conceptual tests were administered to assess students' understanding of electric circuits before, during and after the teaching intervention. Results indicated that the combination of RE and VE enhanced students' conceptual understanding more than the use of RE alone. A further analysis showed that differences between groups on that part of the curriculum in which the experimental group used VE and the control group RE, in favour of VE.

Analytical methods for tracing pharmaceutical residues in water and wastewater

Abstract: The focus of environmental analysis and determination of chemicals in the environment has recently been extended from the more classical pollutants to new contaminant categories including pharmaceuticals This is attributed mainly to the development of new analytical techniques including liquid chromatography with tandem mass spectrometry (LC-MS 2 ) and gas chromatography with mass spectrometry (GC-MS), which enable the determination of such compounds down to the ng/l level This article reviews the most recent developments and applications within water and wastewater environmental matrices

Scheduling Workflows with Budget Constraints

Abstract: Grids are emerging as a promising solution for resource and computation demanding applications. However, the heterogeneity of resources in Grid computing, complicates resource management and scheduling of applications. In addition, the commercialization of the Grid requires policies that can take into account user requirements, and budget considerations in particular. This paper considers a basic model for workflow applications modelled as Directed Acyclic Graphs (DAGs) and investigates heuristics that allow to schedule the nodes of the DAG (or tasks of a workflow) onto resources in a way that satisfies a budget constraint and is still optimized for overall time. Two different approaches are implemented, evaluated and presented using four different types of basic DAGs.

Drawing on a Theoretical Model to Study Students’ Understandings of Fractions

Abstract: Teaching and learning fractions has traditionally been one of the most problematic areas in primary school mathematics. Several studies have suggested that one of the main factors contributing to this complexity is that fractions comprise a multifaceted notion encompassing five interrelated subconstructs (i.e., part-whole, ratio, operator, quotient, and measure). Kieren was the first to establish that the concept of fractions is not a single construct, but consists of several interrelated subconstructs. Later on, in the early 1980s, Behr et al. built on Kieren’s conceptualization and suggested a theoretical model linking the five subconstructs of fractions to the operations of fractions, fraction equivalence, and problem solving. In the present study we used this theoretical model as a reference point to investigate students’ constructions of the different subconstructs of fractions. In particular, using structural equation modeling techniques to analyze data of 646 fifth and sixth graders’ performance on fractions, we examined the associations among the different subconstructs of fractions as well as the extent to which these subconstructs explain students’ performance on fraction operations and fraction equivalence. To a great extent, the data provided support to the associations included in the model, although, they also suggested some additional associations between the notions of the model. We discuss these findings taking into consideration the context in which the study was conducted and we provide implications for the teaching of fractions and suggestions for further research.

Snakes based segmentation of the common carotid artery intima media.

Abstract: Ultrasound measurements of the human carotid artery walls are conventionally obtained by manually tracing interfaces between tissue layers. In this study we present a snakes segmentation technique for detecting the intima-media layer of the far wall of the common carotid artery (CCA) in longitudinal ultrasound images, by applying snakes, after normalization, speckle reduction, and normalization and speckle reduction. The proposed technique utilizes an improved snake initialization method, and an improved validation of the segmentation method. We have tested and clinically validated the segmentation technique on 100 longitudinal ultrasound images of the carotid artery based on manual measurements by two vascular experts, and a set of different evaluation criteria based on statistical measures and univariate statistical analysis. The results showed that there was no significant difference between all the snakes segmentation measurements and the manual measurements. For the normalized despeckled images, better snakes segmentation results with an intra-observer error of 0.08, a coefficient of variation of 12.5%, best Bland–Altman plot with smaller differences between experts (0.01, 0.09 for Expert1 and Expert 2, respectively), and a Hausdorff distance of 5.2, were obtained. Therefore, the pre-processing of ultrasound images of the carotid artery with normalization and speckle reduction, followed by the snakes segmentation algorithm can be used successfully in the measurement of IMT complementing the manual measurements. The present results are an expansion of data published earlier as an extended abstract in IFMBE Proceedings (Loizou et al. IEEE Int X Mediterr Conf Medicon Med Biol Eng POS-03 499:1–4, 2004).

Analysis of the quantum numbers J(PC) of the X(3872) particle.

Abstract: The authors present an analysis of angular distributions and correlations of the X(3872) in the exclusive decay mode X(3872) {yields} J/{psi}{pi}{sup +}{pi}{sup -} with J/{psi} {yields} {mu}{sup +}{mu}{sup -}. They use 780 pb{sup -1} of data from p{bar p} collisions at {radical}s = 1.96 TeV collected with the CDF II detector at the Fermilab Tevatron. They derive constraints on spin, parity, and charge conjugation parity of the X(3872) by comparing measured angular distributions of the decay products with predictions for different J{sup PC} hypotheses. The assignments J{sup PC} = 1{sup ++} and 2{sup -+} are the only ones consistent with the data.

Downsizing and Stakeholder Orientation Among the Fortune 500: Does Family Ownership Matter?

Abstract: While downsizing has been widely studied, its connection to firm ownership status and the reasons behind it are missing from extant research. We explore the relationship between downsizing and family ownership status among Fortune 500 firms. We␣propose that family firms downsize less than non-family firms, irrespective of performance, because their relationship with employees is based on normative commitments rather than financial performance alone. We suggest that their actions are related to employee- and community-friendly policies. We find that family businesses do downsize less irrespective of financial performance considerations. However, their actions are not related to their employee- or community-friendly practices. The results raise issues related to the motivations of large multinationals to␣downsize and the drivers of their stakeholder management practices.

COL4A3/COL4A4 mutations producing focal segmental glomerulosclerosis and renal failure in thin basement membrane nephropathy.

Abstract: Mutations in the COL4A3/COL4A4 genes of type IV collagen have been found in ∼40% of cases of thin basement membrane nephropathy, which is characterized by microscopic hematuria and is classically thought to cause proteinuria and chronic renal failure rarely. Here we report our observations of 116 subjects from 13 Cypriot families clinically affected with thin basement membrane nephropathy. These families first came to our attention because they segregated microscopic hematuria, mild proteinuria, and variable degrees of renal impairment, but a dual diagnosis of focal segmental glomerulosclerosis (FSGS) and thin basement membrane nephropathy was made in 20 biopsied cases. Molecular studies identified founder mutations in both COL4A3 and COL4A4 genes in 10 families. None of 82 heterozygous patients had any extrarenal manifestations, supporting the diagnosis of thin basement membrane nephropathy. During follow-up of up to three decades, 31 of these 82 patients (37.8%) developed chronic renal failure and 16 (19.5%) reached end-stage renal disease. Mutations G1334E and G871C were detected in seven and three families, respectively, and were probably introduced by founders. We conclude that these particular COL4A3/COL4A4 mutations either predispose some patients to FSGS and chronic renal failure, or that thin basement membrane nephropathy sometimes coexists with another genetic modifier that is responsible for FSGS and progressive renal failure. The findings presented here do not justify the labelling of thin basement membrane nephropathy as a benign condition with excellent prognosis.

The association between audit committees, compensation incentives, and corporate audit fees

Abstract: This study uses audit fee data from the 2001–2003 reporting periods to examine the relationship between measures of audit committee effectiveness and compensation incentives with corporate audit fees. Our results suggest that audit committee size, committee member expertise, and committee member independence are positively associated to audit fee levels, consistent with the notion that audit committees serve as a complement to external auditors in monitoring management. In contrast, CEO long-term pay and insider ownership are inversely related to audit fee levels, substituting for external audit effort in motivating management. Notwithstanding results on the full sample of firm-years, we uncover significant differences in the determinants of audit fees between the years examined. An important implication of these results is that explaining the intra-firm variation in audit fees over time is clearly necessary in order to understand the antecedents and consequences of audit fees.

Earnings behaviour of financially distressed firms:The role of institutional ownership

Abstract: Using a sample of 859 U.S. bankruptcy-filing firms over the period 1986-2004, we examine the earnings behaviour of managers during the distressed period by looking at sources of abnormal accruals prior to the bankruptcy-filing year. Results show that managers of highly distressed firms shift earnings downwards prior to the bankruptcy filing. We test and provide evidence in support of two potential contributing factors. First, top-level management turnover among distressed firms leads new managers to earnings bath choices during the distressed period. Second, qualified audit opinions exert pressure on managers to follow more conservative earnings behaviour during the distressed period. Evidence is also provided that the management of distressed firms with lower (higher) institutional ownership has greater (lesser) tendency to manage earnings downwards. Results also show that higher institutional ownership mitigates the negative abnormal returns of firms with top management turnover. To the authors' knowledge, this is the first study that attempts to examine whether institutional ownership relates to market reaction in conjunction with a top management turnover or a qualified audit opinion during the distressed period. Prior studies focused on the investigation of earnings management or institutional ownership (separately) during the distressed period, but did not examine if the effect of institutional ownership on earnings behaviour also influences subsequent returns. Thus, the results of this study should be of interest to analysts, standard setters and regulatory bodies since our results show that management turnover, qualified audit opinions and firm governance mechanisms affect the quality of earnings and the level of abnormal returns. © 2007 Accounting Foundation, The University of Sydney.

Response of seismically isolated buildings considering poundings

Abstract: Numerical simulations and parametric studies have been used to investigate the influence of potential poundings of seismically isolated buildings with adjacent structures on the effectiveness of seismic isolation. Poundings are assumed to occur at the isolation level between the seismically isolated building and the surrounding moat wall. After assessing some common force-based impact models, a variation of the linear viscoelastic impact model is proposed to avoid tensile impact forces during detachment, while enabling the consideration of permanent plastic deformations at the vicinity of the impact. A large number of numerical simulations of seismically isolated buildings with different characteristics have been conducted under six earthquake excitations in order to investigate the influence of various design parameters and conditions on the peak floor accelerations and interstorey deflections during poundings. The numerical simulations demonstrate that poundings may substantially increase floor accelerations, especially t the base floor where impacts occur. Higher modes of vibration are excided during poundings, increasing the interstorey deflections, instead of retaining an almost rigid-body motion of the superstructure, which is aimed with seismic isolation. Impact stiffness seems to affect significantly the acceleration response at the isolation level, while the displacement response is more insensitive to the variation of the impact stiffness. Finally, the results indicate that providing excessive flexibility at the isolation system to minimize the floor accelerations may lead to a building vulnerable to poundings, if the available seismic gap is limited. Copyright © 2007 John Wiley & Sons, Ltd.

A unified and general framework for argumentation-based negotiation

Abstract: This paper proposes a unified and general framework for argumentation-based negotiation, in which the role of argumentation is formally analyzed. The framework makes it possible to study the outcomes of an argumentation-based negotiation. It shows what an agreement is, how it is related to the theories of the agents, when it is possible, and how this can be attained by the negotiating agents in this case. It defines also the notion of concession, and shows in which situation an agent will make one, as well as how it influences the evolution of the dialogue.

Low-temperature H2-SCR of NO on a novel Pt/MgO-CeO2 catalyst

Abstract: The selective catalytic reduction of NO by H 2 under strongly oxidizing conditions (H 2 -SCR) in the low-temperature range of 100–200 °C has been studied over Pt supported on a series of metal oxides (e.g., La 2 O 3 , MgO, Y 2 O 3 , CaO, CeO 2 , TiO 2 , SiO 2 and MgO-CeO 2 ). The Pt/MgO and Pt/CeO 2 solids showed the best catalytic behavior with respect to N 2 yield and the widest temperature window of operation compared with the other single metal oxide-supported Pt solids. An optimum 50 wt% MgO-50wt% CeO 2 support composition and 0.3 wt% Pt loading (in the 0.1–2.0 wt% range) were found in terms of specific reaction rate of N 2 production (mols N 2 /g cat s). High NO conversions (70–95%) and N 2 selectivities (80–85%) were also obtained in the 100–200 °C range at a GHSV of 80,000 h −1 with the lowest 0.1 wt% Pt loading and using a feed stream of 0.25 vol% NO, 1 vol% H 2 , 5 vol% O 2 and He as balance gas. Addition of 5 vol% H 2 O in the latter feed stream had a positive influence on the catalytic performance and practically no effect on the stability of the 0.1 wt% Pt/MgO-CeO 2 during 24 h on reaction stream. Moreover, the latter catalytic system exhibited a high stability in the presence of 25–40 ppm SO 2 in the feed stream following a given support pretreatment. N 2 selectivity values in the 80–85% range were obtained over the 0.1 wt% Pt/MgO-CeO 2 catalyst in the 100–200 °C range in the presence of water and SO 2 in the feed stream. The above-mentioned results led to the obtainment of patents for the commercial exploitation of Pt/MgO-CeO 2 catalyst towards a new NO x control technology in the low-temperature range of 100–200 °C using H 2 as reducing agent. Temperature-programmed desorption (TPD) of NO, and transient titration of the adsorbed surface intermediate NO x species with H 2 experiments, following reaction, have revealed important information towards the understanding of basic mechanistic issues of the present catalytic system (e.g., surface coverage, number and location of active NO x intermediate species, NO x spillover).

Short Term Electric Load Forecasting: A Tutorial

Abstract: Short term load forecasting is an important tool for every electric utility A significant number of operating decisions are based on short term load forecasts The accuracy of these forecasts leads to significant savings in operating costs and to an enhanced system reliability The technical literature is abundant with techniques and approaches for performing or improving short term load forecasting A number of approaches work well with certain power systems or certain geographical areas, while they fail for some other systems due to the nature of the electric load demand: it is complex, highly nonlinear, and dependent on weather, seasonal and social factors This chapter provides a tutorial introduction to the short term load forecasting problem and a brief summary of the various approaches that have been proposed, from conventional to computational intelligence methods

The Cyprus Conflict: Root Causes and Implications for Peacebuilding

Abstract: A survey in 2000--02 in both the Greek- and Turkish-Cypriot communities examines the beliefs about the root causes of the Cyprus conflict, the political culture, social attitudes, and future solutions. This article shows that both external and internal factors, both psychological and contextual, have played an influential role in the creation and perpetuation of the conflict -- a view that challenges the selective official positions that define the problem as either a problem of external factors or merely an internal discord between the majority and minority population. The article highlights the complexity that characterizes intractable conflicts. It promotes the view that internal, contextual, and psychological factors are equally significant, as are legal and political factors, to be taken into account when addressing peacebuilding and future solutions. Some generalizations will be made with regard to the value of micro-level (i.e. societal studies) research in the field of conflict resolution and political psychology.

Measurement of the inclusive jet cross section using the kT algorithm in pp̄ collisions at s=1.96TeV with the CDF II detector

Abstract: The authors report on measurements of the inclusive jet production cross section as a function of the jet transverse momentum in p{bar p} collisions at {radical}s = 1.96 TeV, using the k{sub T} algorithm and a data sample corresponding to 1.0 fb{sup -1} collected with the Collider Detector at Fermilab in Run II. The measurements are carried out in five different jet rapidity regions with |y{sup jet}| < 2.1 and transverse momentum in the range 54 < p{sub T}{sup jet} < 700 GeV/c. Next-to-leading order perturbative QCD predictions are in good agreement with the measured cross sections.