bluuebunny/crossref_metadata_2025 huggingface dataset:
Hybrid of ARIMA-GARCH Modeling in Rainfall Time Series
Authors: Yusof Fadhilah , Kane Ibrahim Lawal , Yusop Zulkifli
Published: September 2013

The dependence structure of rainfall is usually very complex both in time and space. It is shown in this paper that the daily rainfall series of Ipoh and Alorsetar are affected by nonlinear characteristics of the variance often referred to as variance clustering or volatility, where large changes tend to follow large changes and small changes tend to follow small changes. In most empirical modeling of hydrological time series, the focus was on modeling and predicting the mean behavior of the time series through conventional methods of an Autoregressive Moving Average (ARMA) modeling proposed by the Box Jenkins methodology. The conventional models operate under the assumption that the series is stationary that is: constant mean and either constant variance or season-dependent variances, however, does not take into account the second order moment or conditional variance, but they form a good starting point for time series analysis. The residuals from preliminary ARIMA models derived from the daily rainfall time series were tested for ARCH behavior. The autocorrelation structure of the residuals and the squared residuals were inspected, the residuals are uncorrelated but the squared residuals show autocorrelation, the Ljung-Box test confirmed the results. McLeod-Li test and a test based on the Lagrange multiplier (LM) principle were applied to the squared residuals from ARIMA models. The results of these auxiliary tests show clear evidence to reject the null hypothesis of no ARCH effect. Hence indicates that GARCH modeling is necessary. Therefore the composite ARIMA-GARCH model captures the dynamics of the daily rainfall series in study areas more precisely. On the other hand, Seasonal ARIMA model became a suitable model for the monthly average rainfall series of the same locations treated.
Variance Corrected Proportional Hazard Model for the Analysis of Recurrent Multiple Failure Modes
Authors: Amarasingh Nuwani S. e , Sunethra A. A. , Sooriyarachchi M. R.
Published: September 2013

Automobiles do fail repetitively owing to different types of failures. Modeling of such products should concern dissimilar recurrent failure types. Failure types are habitually correlated to each other. This study has utilized variance corrected proportional hazard models (VCPH) for modeling multiple failure occurrences of different failure types of automobiles taking into account the correlated nature of the failures. Though original Cox proportional hazard (PH) models require failure events to be independent, VCPH can handle non independency. In this study, this model is utilized for the analysis of multi-type, multiple occurrences of failures in automobiles, where the assumption of independence among failure times is violated. The VCPH model obtains parameter estimates by first fitting a Cox PH model that ignores the dependence structure and then replaces the naive standard errors with estimates from empirical sandwich variance estimation in order to incorporate the non-independence of times between failures. This study applies the Prentice, Williams and Petersen (PWP) models to model multiple occurrences of different failures in automobiles as proportionality among failure events were well demonstrated when risk interval is taken as ‘gap time’ and since PWP models are specified with a gap time risk interval. The Information Matrix (IM) test of White is applied for the checking of the PH model specification with multivariate failure time data. White’s paper on inference from missspecified models presented the IM test as a test for correct model specification. The objective of the study was to find out how automobile type and type of failure affect the time to failure. Applying the best suitable VCPH model to the data, it was revealed that both automobile and failure type have an impact on timing of failure however this effect doesn’t change over multiple failure occurrences of the automobile.
A Statistical Test for the Stability of Covariance Structure
Authors: Yusoff Nur Syahidah , Djauhari Maman Abdurachman
Published: September 2013

The stability of covariance matrix is a major issue in multivariate analysis. As can be seen in the literature, the most popular and widely used tests are Box M-test and Jennrich J-test introduced by Box in 1949 and Jennrich in 1970, respectively. These tests involve determinant of sample covariance matrix as multivariate dispersion measure. Since it is only a scalar representation of a complex structure, it cannot represent the whole structure. On the other hand, they are quite cumbersome to compute when the data sets are of high dimension since they do not only involve the computation of determinant of covariance matrix but also the inversion of a matrix. This motivates us to propose a new statistical test which is computationally more efficient and, if it is used simultaneously with M-test or J-test, we will have a better understanding about the stability of covariance structure. An example will be presented to illustrate its advantage
The Design of Learning Material for Poor Comprehenders: Lessons Learnt from Experts
Authors: Cofinia Vincenza , De la Prieta Fernando , Di Mascio Tania , Gennari Rosella , Marenzi Ivana , Vittorini Pierpaolo
Published: September 2013

TERENCE is an FP7 ICT European project that is developing an adaptive learning system for poor comprehenders and their educators. The learning material is made of stories and smart games for stimulating reading comprehension. The design of stories and smart games is also based on data collected from experts for the analysis of the context of use of the system, and is incrementally revised via evaluations of prototypes of stories and games, with domain experts of text comprehension or education as participants. In particular, since smart games are semi-automatically generated via artificial intelligence technologies, they contain mistakes that have to be fixed by experts of pedagogy before the games are given to learners. In this paper we focus on the design and evaluations of the TERENCE stories and smart games for poor comprehenders via lessons learnt with domain experts.
Relaxing Synchronization Constraints in Distributed Agent-based Simulations
Authors: Rihawi Omar , Secq Yann , Mathieu Philippe
Published: September 2013

In the context of situated agents simulations, when the number of agents increases, the number of their interactions will be increased too. These growths leads to higher requirements in memory and computation power. When simulations involve millions of agents, it becomes necessary to distribute the simulator on a computer network. In this paper we study the impact of synchronization policies in such context. Our claim is that when millions of agents are used in a simulation, because observations of these complex systems is made at the population level, emergent properties at the macroscopic level should not be highly impacted if some failure appears at the microscopic level. This paper is focused on the study of the impact of synchronization relaxation in the context of large scale situated agents simulations. We evaluate the cost in performance of several synchronization policies and their impact on the macroscopic properties of simulations. To that aims, we study three different time management mechanisms and evaluate them on two multi-agent applications.
Phenomenographic Study of Students’ Manipulative Skills During Transition from Primary to Secondary School
Authors: Mohd Fadzil Hidayah , Mohd Saat Rohaida
Published: September 2013

Manipulative skills include skills in handling materials and apparatus in the context of scientific investigation. Students lack exposure in “hands-on” activities at primary school lead to insufficient manipulative skills and they may carry this problem with them to secondary school. This problem will pose a greater problem during school transition. School transition is a challenging process for students whereby they have to adapt with social issues to fit into their new environment. This study resulted from a longitudinal study with the implementation of phenomenographic research design. The research was administered to 10 primary school students (Year Six) and they were re-interviewed in secondary school (Form One). Students’ capability in handling thermometer, measuring cylinder, Bunsen burner and microscope were observed in order to get comprehensive understanding of students’ manipulative skills during the process of transition from primary to secondary school. Findings revealed that students have not fully developed the basic skills in using and handling scientific apparatus. Five (5) categories of description emerged from data that represented the nature of the students’ manipulative skills, namely: (1) non-systematic operation of tasks, (2) non-effective management of time and workplace, (3) haphazard safety and precautionary measures, (4) poor technical skills, and (5) problem in numeracy and drawing specimen.
Comparison Between Characteristics of Creativity in Physics Practical Work and Physics Innovative Project Among Pre-service Physics Teacher
Authors: Mohtar Lilia Ellany , Phang Fatin Aliah
Published: September 2013

This research is intended to study the characteristics of creativity in two practical-based physics learning activities which are physics practical work (PPW) and physics innovative project (PIP) among pre-service physics teacher at Universiti Teknologi Malaysia (UTM). The study was conducted in one semester among 12 physics education undergraduates from the Faculty of Education, UTM. Two sets of survey questionnaires were used to collect data on characteristics of creativity in PPW and PIP respectively and the data was analyzed using descriptive analysis. The result of the study shows that six characteristics of creativity are highlighted more when the pre-service physics teachers performed PIP except openness which are the same in both activities.  Based on the findings, it is found that activities like inquiry based learning such as PIP can encourage more characteristics of creativity compared to PPW that is guided by manual books. Therefore, it is suggested that activities like PIP should be delivered to the pre-service teachers as one of the exercises to generate creative teachers.
Performance of Undergraduate Students in Mathematical Problem Posing Tasks
Authors: Ghasempour Zahra , Bakar Md. Nor
Published: September 2013

The mathematical problem posing tasks are relevant issues in the development of higher education curriculum and improving it for developing nations require its inclusion in the curriculum as a complement to problem solving tasks. We investigate the types of problem posing abilities, related difficulties and levels of performances in “calculus-1” among first year undergraduates in Iran. The research instrument consists of text book "integral" problems reconstructed through "add or remove condition" with structured situation and "change the problem context" with semi-structured situation. Twenty-six first year undergraduates among moderate and high achievers are participated in answering the test. Furthermore, five of them are enrolled in semi-structured interview after the test. The preliminary results reveal that the percentage of "expert" students (69%) in generating problem through "add or remove condition" strategies are higher than those (18%) implementing "change the context" which is connected to high-order-thinking skills. However, the majority of participants are greatly able to perform two-third of questions correctly. The significant weakness related to the conceptual and procedural understandings in terms of the high-order-thinking skills are observed among them. We assert that the students’ problem posing performances can be fostered by incorporating problem posing activities in teaching-learning materials.
Combined Use of Design of Experiment and Computer Simulation for Resources Level Determination in Concrete Pouring Process
Authors: Zahraee Seyed Mojib , Hatami Milad , Mohd Yusof Noordin , Mohd Rohani Jafri , Ziaei Farhad
Published: September 2013

Construction managers and planners are always involved in answering questions regarding the effects of changing the level of resources involved in construction activities on project performance. The planners strive to determine the best resource level combination that optimizes the performance measures such as productivity. In this study, a unique approach involving the combined use of a powerful Quality Engineering tool, Design of Experiment (DOE) and Simulation for determining the best combination of resources level for a real-world construction process, viz. concrete pouring process. DOE enabled the experimental plan to be designed in the form of a twice replicated, 24 full factorial designs with 5 center points. This experimental plan involved 37 experiments. Simulation has enabled the construction process investigated to be realistically modelled. Therefore, instead of performing field trials involving 37 experiments, these experiments are simulated in order to obtain the response investigated, which is productivity. A model, for predicting concrete pouring process productivity, was successfully developed and the optimum resources level was also determined.
Peranan Perkongsian Pengetahuan Terhadap Jangkaan Tempoh Graduasi Mahasiswa Pasca Ijazah
Authors: A. Rahim Nur Rifhan , Jusoh Ahmad , Said Hamdan
Published: September 2013

Kajian ini adalah bertujuan untuk mengenal pasti faktor-faktor penentu kejayaan yang mempengaruhi jangkaan tempoh tamat pengajian mahasiswa pasca ijazah. Kajian ini juga ingin melihat interaksi aktiviti perkongsian pengetahuan dengan jangkaan tempoh tamat pengajian mahasiswa pasca ijazah. Kajian ini telah melibatkan seramai 210 orang responden daripada mahasiswa pasca ijazah penyelidikan dalam bidang Sains Sosial di UTM, Johor Bahru. Fakulti yang terlibat adalah Fakulti Pengurusan dan Pembangunan Sumber Manusia (FPPSM) dan Fakulti Pendidikan (FP). Borang kaji selidik merupakan instrumen utama bagi menjawab setiap soalan yang diutarakan. Aplikasi “Google Docstoc” telah diaplikasikan dalam mengagihkan borang soal selidik kepada responden. Kesemua data dianalisis dengan menggunakan perisian Statistical Package for Social Sciences 18.0 (SPSS). Faktor-faktor penentu kejayaan yang diketengahkan adalah terdiri daripada faktor individu, faktor kualiti seliaan dan faktor sokongan organisasi. Hasil kajian menunjukkan bahawa faktor individu, faktor kualiti seliaan dan faktor sokongan organisasi mempunyai hubungan positif dengan jangkaan tempoh tamat pengajian pada tahap signifikan p<0.05. Hasil kajian juga menunjukkan bahawa aktiviti perkongsian pengetahuan merupakan moderator bagi faktor kualiti seliaan dan faktor sokongan organisasi pada tahap signifikan p<0.05.
hanasia: Melanggar Etika dan Hak Asasi Manusia
Authors: Mohd Yusof Farahwahida , Nizar Tamar Jaya , Muhammad Siti Norlina , Mohd Nazir Nurain
Published: September 2013

Dalam era moden ini kemajuan ilmu sains dan teknologi menjadi semakin pesat kerana munculnya pelbagai penemuan yang banyak memberi manfaat kepada manusia. Hampir semua aspek kehidupan manusia berkait rapat dengan sains dan teknologi. Jika dibandingkan penemuan teknologi tersebut, perkembangan teknologi dalam bidang perubatan dilihat sangat memberangsangkan. Melalui pengetahuan dan penggunaan teknologi perubatan yang sangat maju, maka diagnosis mengenai suatu penyakit dapat dilakukan dengan lebih sempurna. Hasilnya rawatan penyakit dapat dipraktikkan secara lebih efektif. Bahkan perhitungan saat kematian penderita penyakit tertentu dapat dilakukan secara lebih tepat. Kini, hasil daripada perkembangan dan kemajuan dalam bidang sains dan teknologi terutamanya kemajuan dalam bidang perubatan, nyawa manusia telah dapat dilanjutkan dengan menggunakan ubatan atau alat pernafasan moden. Manusia seakan-akan dapat menentukan sama ada ingin mematikan atau menghidupkan seseorang pesakit. Dengan perkembangan teknologi dalam bidang perubatan ini, tidak mustahil ia bakal mengundang masalah yang rumit. Keadaan ini menimbulkan beberapa isu tentang kematian yang dikaitkan dengan euthanasia yang bermakna kematian dengan aman tanpa kesakitan. Euthanasia boleh dibahagikan kepada beberapa kategori iaitu euthanasia aktif, euthanasia pasif, voluntary euthanasia, non-voluntary euthanasia dan involuntary euthanasia. Dalam Islam misalnya, kepercayaan bahawa kehidupan dan kematian manusia adalah ditentukan oleh Allah dan manusia tidak menpunyai hak untuk menamatkan hidupnya sendiri. Jelaslah isu euthanasia menerima bantahan yang tegas daripada para ulama dan syariah Islamiah. Oleh itu, isu euthanasia bukan melibatkan kebajikan pesakit sahaja tetapi juga melibatkan sensitiviti ahli keluarga, ahli perubatan, agama dan lain-lain. Dengan ini, isu euthanasia harus diuruskan secara teliti supaya ia tidak menimbulkan kekeliruan dalam kalangan masyarakat.
Preferred Communication Channels to Foster Energy Conservation Behaviour among Public Office Building Users: A Study in Kota Iskandar
Authors: Lee Yee Ying , Choong Weng Wai , Mohammed Abdul Hakim , Abdullah Fatin Aliah Phang
Published: September 2013

Energy is an important source for a nation to achieve development and urbanisation. In Malaysia, the need for energy efficiency was explicitly addressed in the Ninth and Tenth Malaysia Plans. The Malaysian government has directed all government office buildings to reduce their energy usage by 10%. However, the lack of awareness and inappropriate behaviour among building users are barriers. It is believed that the successful use of appropriate communication channels can improve commitment and behaviour among building users to conserve energy. Hence, this research examines which communication channels are preferred by government office users to foster energy conservation behaviour. This research focuses on government staff working in public office building at Kota Iskandar, which is located in a new developing township of Nusajaya, one of the largest property development projects in Southeast Asia. The town is newly constructed and therefore wastage due to obsolescence factors can be minimised. Questionnaires were distributed to the staff at the State Government Department Complexes. This survey indicated that respondents highly appreciate visual communication when receiving information, while posters emerged as the most effective and preferable information-delivering channel for respondents.
Numerical Study of Transitional Rough Wall Boundary Layer
Authors: Elsner Witold , Warzecha Piotr
Published: September 2013

This paper presents the verification of the boundary layer modeling approach, which relies on a γ-Reθt model proposed by Menter et al. (2006, “A Correlation-Based Transition Model using Local Variables—Part I: Model Formation,” J. Turbomach., 128(3), pp. 413–422). This model was extended by laminar-turbulent transition correlations proposed by Piotrowski et al. (2008, “Transition Prediction on Turbine Blade Profile with Intermittency Transport Equation,” Proceedings of the ASME Turbo Expo, Paper No. GT2008-50796) as well as Stripf et al.'s (2009, “Extended Models for Transitional Rough Wall Boundary Layers with Heat Transfer—Part I: Model Formulation,” J. Turbomach., 131(3), 031016) correlations, which take into account the effects of surface roughness. To blend between the laminar and fully turbulent boundary layer over rough wall, the modified intermittency equation is used. To verify the model, a flat plate with zero and nonzero pressure gradient test cases as well as the high pressure turbine blade case were chosen. Furthermore, the model was applied for unsteady calculations of the turbine blade profile as well as the Lou and Hourmouziadis (2000, “Separation Bubbles Under Steady and Periodic-Unsteady Main Flow Conditions,” J. Turbomach., 122(4), pp. 634–643) flat plate test case, with an induced pressure profile typical for a suction side of highly-loaded turbine airfoil. The combined effect of roughness and wake passing were studied. The studies proved that the proposed modeling approach (ITMR hereinafter) appeared to be sufficiently precise and enabled for a qualitatively correct prediction of the boundary layer development for the tested simple flow configurations. The results of unsteady calculations indicated that the combined impact of wakes and the surface roughness could be beneficial for the efficiency of the blade rows, but mainly in the case of strong separation occurring on highly-loaded blade profiles. It was also demonstrated that the roughness hardly influences the location of wake induced transition, but has an impact on the flow in between the wakes.
Thermal Analysis of AlGaN/GaN HEMTs Using Angular Fourier-Series Expansion
Authors: Babić Dubravko I.
Published: September 2013

Thermal analysis of planar and near-square semiconductor device chips employing angular Fourier-series (AFS) expansion is presented for the first time. The determination of the device peak temperature using AFS requires only a single two-dimensional computation, while full three-dimensional temperature distribution can be obtained, if desired, by successively adding higher-order Fourier terms, each of which requires a separate 2D computation. The AFS method is used to compare the heat spreading characteristics of AlGaN/GaN high-electron-mobility transistors (HEMTs) fabricated on silicon, silicon carbide, and synthetic diamond. We show that AlGaN/GaN HEMTs built using GaN/diamond technology can offer better than half the thermal resistance of GaN/SiC HEMTs under worst-case cooling conditions. Furthermore, we show that, if left unmanaged, an inherent and non-negligible thermal boundary resistance due to the integration of semiconductor epilayers with non-native substrates will dampen the benefits of highly conductive substrates such as SiC and diamond.
Modeling and Optimization of Superhydrophobic Condensation
Authors: Miljkovic Nenad , Enright Ryan , Wang Evelyn N.
Published: September 2013

Superhydrophobic micro/nanostructured surfaces for dropwise condensation have recently received significant attention due to their potential to enhance heat transfer performance by shedding water droplets via coalescence-induced droplet jumping at length scales below the capillary length. However, achieving optimal surface designs for such behavior requires capturing the details of transport processes that is currently lacking. While comprehensive models have been developed for flat hydrophobic surfaces, they cannot be directly applied for condensation on micro/nanostructured surfaces due to the dynamic droplet-structure interactions. In this work, we developed a unified model for dropwise condensation on superhydrophobic structured surfaces by incorporating individual droplet heat transfer, size distribution, and wetting morphology. Two droplet size distributions were developed, which are valid for droplets undergoing coalescence-induced droplet jumping, and exhibiting either a constant or variable contact angle droplet growth. Distinct emergent droplet wetting morphologies, Cassie jumping, Cassie nonjumping, or Wenzel, were determined by coupling of the structure geometry with the nucleation density and considering local energy barriers to wetting. The model results suggest a specific range of geometries (0.5–2 μm) allowing for the formation of coalescence-induced jumping droplets with a 190% overall surface heat flux enhancement over conventional flat dropwise condensing surfaces. Subsequently, the effects of four typical self-assembled monolayer promoter coatings on overall heat flux were investigated. Surfaces exhibiting coalescence-induced droplet jumping were not sensitive (<5%) to the coating wetting characteristics (contact angle hysteresis), which was in contrast to surfaces relying on gravitational droplet removal. Furthermore, flat surfaces with low promoter coating contact angle hysteresis (<2 deg) outperformed structured superhydrophobic surfaces when the length scale of the structures was above a certain size (>2 μm). This work provides a unified model for dropwise condensation on micro/nanostructured superhydrophobic surfaces and offers guidelines for the design of structured surfaces to maximize heat transfer. Keywords: superhydrophobic condensation, jumping droplets, droplet coalescence, condensation optimization, environmental scanning electron microscopy; micro/nanoscale water condensation, condensation heat transfer.
Steady and Unsteady Air Impingement Heat Transfer for Electronics Cooling Applications
Authors: Arik Mehmet , Sharma Rajdeep , Lustbader Jason , He Xin
Published: September 2013

This paper focuses on two forced convection methods—steady jet flow and pulsating flow by synthetic jets—that can be used in applications requiring significant amounts of heat removal from electronics components. Given the dearth of available data, we have experimentally investigated steady jets and piezoelectrically driven synthetic jets that provide pulsating flow of air at a high coefficient of performance. To mimic a typical electronics component, a 25.4-mm × 25.4-mm vertical heated surface was used for heat removal. The impingement heat transfer, in the form of Nusselt number, is reported for both steady and unsteady jets over Reynolds numbers from 100 to 3000. The effect of jet-to-plate surface distance on the impingement heat transfer is also investigated. Our results show that synthetic jets can provide significantly higher cooling than steady jets in the Reynolds number range of 100 to 3000. We attribute the superior performance of synthetic jets to vortex shedding associated with the unsteady flow.
Topology Optimization for an Internal Heat-Conduction Cooling Scheme in a Square Domain for High Heat Flux Applications
Authors: Dirker Jaco , Meyer Josua P.
Published: September 2013

Conductive heat transfer is of importance in the cooling of electronic equipment. However, in order for conductive cooling to become effective, the use of high-conducting materials and the correct distribution thereof is essential, especially when the volume which needs to be cooled has a low thermal conductivity. An emerging method of designing internal solid-state conductive systems by means of topology optimization is considered in this paper. In this two-dimensional study, the optimum distribution of high conductive material within a square-shaped heat-generating medium is investigated by making use of the “method or moving asymptotes” (MMA) optimization algorithm coupled with a numerical model. The use of such a method is considered for a number of cost (driving) functions and different control methods to improve the definiteness of the boundaries between the heat-generating and high-conduction regions. It is found that the cost function used may have a significant influence on the optimized material distribution. Also of interest in this paper are the influences of thermal conductivity and the proportion of the volume occupied by the high-conducting solid on the resulting internal cooling structure distribution and its thermal conduction performance. For a square domain with a small exposed isothermal boundary centered on one edge, a primary V-shaped structure was found to be predominantly the most effective layout to reduce the peak operating temperature and to allow for an increase in the internal heat flux levels.
Experimental Investigation of Microscale Effects in Perforated Plate Aerodynamics
Authors: Szwaba Ryszard , Ochrymiuk Tomasz , Lewandowski Tomasz , Czerwinska Justyna
Published: September 2013

This paper contains an extensive analysis of the flow in microholes based on an experimental investigation. Experiments of the gas flow past a perforated plate with microholes (110μm) were carried out. A wide range of pressure differences between the inlet and the outlet were investigated for that purpose. Two distinguishable flow regimes were obtained: the laminar flow with the slip effects and the turbulence transition regime for a very low Reynolds number. The results are in good agreement with the theory, simulations, experiments for large scale perforated plates, and compressible flows in microtubes. The relation between the mass flow rate and the Knudsen, Reynolds, and Mach numbers for the laminar and transitional regime was obtained. It is a quadratic function of the Reynolds and Knudsen numbers (ReKn) based on the hole's diameter. The value of the first order tangential momentum accommodation coefficient was estimated. It shows a strong relation to the inlet Knudsen number.
PHASE EVOLUTION IN Fe–Mn–Si SHAPE MEMORY ALLOYS DUE TO FORGING SPEED
Authors: ESKIL MURAT , KANCA ERDOGAN
Published: September 2013

The objective of this investigation is to compare the crystallographic characteristics of two different compositions of Fe – Mn – Si alloys forged with the newly designed and constructed High Energy Rate Forming (HERF) hammer with conventional hydraulic and mechanical presses. The degree of martensite formation may depend on metal forming conditions. For both of the alloys, one of the specimens was investigated in as "prepared form", the other specimen was investigated after air cooling with homogenization treatment and three specimens were deformed in different velocities after homogenization treatments. The changes which occurred in the transformation parameters of two FeMnSi alloys with different compositions due to the effects of thermal and mechanical procedures have been studied by using X-ray diffraction. In the alloy specimens cooled to different conditions from the high-temperature γ phase region, γ→ε and γ→ε→α′ martensitic transformations were observed. The lattice parameters (LP) of fcc γ and hcp ε structures were determined, and changes in forging speed on the LPs were found.
STUDY OF BAND STRUCTURE OF TWO-DIMENSIONAL ANISOTROPIC HONEYCOMB PHOTONIC CRYSTALS
Authors: SEDGHI A. , SOUFIANI A. ROUNAGHI
Published: September 2013

Using the plane wave expansion method, we have calculated, for both E and H polarizations, the band structure of 2D anisotropic photonic crystals with honeycomb lattice composed of anisotropic tellurium ( Te ) rods embedded in air background. The two rods in the unit cell are chosen square and circular in shape. Here, from a practical point of view, in order to obtain maximum band gaps, we have also studied the band structure as a function of size of rods.
Low-latency adaptive mode transitions and hierarchical power management in asymmetric clustered cores
Authors: Shifer Eran , Weiss Shlomo
Published: September 2013

Recently, engineering solutions that include asymmetric multicores have been fabricated for low form-factor computing devices, indicating a potential direction for future evolution of processors. In this article we propose an asymmetric clustered core architecture, exhibiting low-latency switching between modes relative to asymmetric multicores, and having similarities with the same asymmetric multicore architecture in the context of a wider dynamic range of the processor power-performance characteristic. Asymmetric clustered cores incur additional microarchitectural complexity and area cost inside a core but exhibit better chip-level integration characteristics compared to asymmetric multicores. Focusing on power efficiency of asymmetric clustered cores, we describe: (1) a hierarchical power management partitioning between the operating system and on-die firmware for coarse-grain switch policies, and (2) core-internal tracking hardware for fine-grain switching. The mode switch policies of the core's tracking hardware are dependent on higher-level directives and hints from the operating system, on-die firmware, and compiler or profiling software. We further explore the potential power management benefits of asymmetric clustered cores relative to asymmetric multicores, demonstrating that the ability of asymmetric clustered cores to use tight training periods for adaptive behavior, with low overhead switching between modes, results in a more efficient utilization of power management directives.
A Practical Liquidity-Sensitive Automated Market Maker
Authors: Othman Abraham , Pennock David M. , Reeves Daniel M. , Sandholm Tuomas
Published: September 2013

Automated market makers are algorithmic agents that enable participation and information elicitation in electronic markets. They have been widely and successfully applied in artificial-money settings, like some Internet prediction markets. Automated market makers from the literature suffer from two problems that contribute to their impracticality and impair their use beyond artificial-money settings: first, they are unable to adapt to liquidity, so that trades cause prices to move the same amount in both heavily and lightly traded markets, and second, in typical circumstances, they run at a deficit. In this article, we construct a market maker that is both sensitive to liquidity and can run at a profit. Our market maker has bounded loss for any initial level of liquidity and, as the initial level of liquidity approaches zero, worst-case loss approaches zero. For any level of initial liquidity we can establish a boundary in market state space such that, if the market terminates within that boundary, the market maker books a profit regardless of the realized outcome.
Preallocation instruction scheduling with register pressure minimization using a combinatorial optimization approach
Authors: Shobaki Ghassan , Shawabkeh Maxim , Rmaileh Najm Eldeen Abu
Published: September 2013

Balancing Instruction-Level Parallelism (ILP) and register pressure during preallocation instruction scheduling is a fundamentally important problem in code generation and optimization. The problem is known to be NP-complete. Many heuristic techniques have been proposed to solve this problem. However, due to the inherently conflicting requirements of maximizing ILP and minimizing register pressure, heuristic techniques may produce poor schedules in many cases. If such cases occur in hot code, significant performance degradation may result. A few combinatorial optimization approaches have also been proposed, but none of them has been shown to solve large real-world instances within reasonable time. This article presents the first combinatorial algorithm that is efficient enough to optimally solve large instances of this problem (basic blocks with hundreds of instructions) within a few seconds per instance. The proposed algorithm uses branch-and-bound enumeration with a number of powerful pruning techniques to efficiently search the solution space. The search is based on a cost function that incorporates schedule length and register pressure. An implementation of the proposed scheduling algorithm has been integrated into the LLVM Compiler and evaluated using SPEC CPU 2006. On x86-64, with a time limit of 10ms per instruction, it optimally schedules 79% of the hot basic blocks in FP2006. Another 19% of the blocks are not optimally scheduled but are improved in cost relative to LLVM's heuristic. This improves the execution time of some benchmarks by up to 21%, with a geometric-mean improvement of 2.4% across the entire benchmark suite. With the use of precise latency information, the geometric-mean improvement is increased to 2.8%.
Scalable high-radix router microarchitecture using a network switch organization
Authors: Ahn Jung Ho , Son Young Hoon , Kim John
Published: September 2013

As the system size of supercomputers and datacenters increases, cost-efficient networks become critical in achieving good scalability on those systems.
High
-radix routers reduce network cost by lowering the network diameter while providing a high bisection bandwidth and path diversity. The building blocks of these large-scale networks are the routers or the switches and they need to scale accordingly to the increasing port count and increasing pin bandwidth. However, as the port count increases, the high-radix router microarchitecture itself needs to scale efficiently. Hierarchical crossbar switch organization has been proposed where a single large crossbar used for a router switch is partitioned into many small crossbars and overcomes the limitations of conventional router microarchitecture. Although the organization provides high performance, it has limited scalability due to excessive power and area overheads by the wires and intermediate buffers.

In this article, we propose scalable router microarchitectures that leverage a network within the switch design of the high-radix routers themselves. These alternative designs lower the wiring complexity and buffer requirements. For example, when a folded-Clos switch is used instead of the hierarchical crossbar switch for a radix-64 router, it provides up to 73%, 58%, and 87% reduction in area, energy-delay product, and energy-delay-area product, respectively. We also explore more efficient switch designs by exploiting the traffic-pattern characteristics of the
global
network and its impact on the
local
network design within the switch for both folded-Clos and flattened butterfly networks. In particular, we propose a
bilateral butterfly
switch organization that has fewer crossbars and global wires compared to the topology-agnostic folded-Clos switch while achieving better low-load latency and equivalent saturation throughput.
Alpha-Methyldopa-Induced Autoimmune Hemolytic Anemia in the Third Trimester of Pregnancy
Authors: Grigoriadis Charalampos , Tympa Aliki , Liapis Angelos , Hassiakos Dimitrios , Bakas Panagiotis
Published: September 2013

Alpha-methyldopa has been demonstrated to be safe for use during pregnancy and is now used to treat gestational hypertension. In pregnancy, alpha-methyldopa-induced autoimmune hemolytic anemia does not have typical features and the severity of symptoms ranges from mild fatigue to dyspnea, respiratory failure, and death if left untreated. A case of alpha-methyldopa-induced autoimmune hemolytic anemia in a 36-year-old gravida 2, para 1 woman at 37+6weeks of gestation is reported herein along with the differential diagnostic procedure and the potential risks to the mother and the fetus.
A Giant Pseudoaneurysm of the Forearm as Unusual Complication of Bacterial Endocarditis
Authors: Arcopinto Michele , Russo Teresa , Ruvolo Antonio , Cittadini Antonio , Saccà Luigi , Napoli Raffaele
Published: September 2013

A 59-year-old man with fever was diagnosed with endocarditis due toStreptococcus bovis. Two weeks after antibiotic therapy was started, he presented with red and painful swelling of the forearm without any sign of systemic inflammation. A giant hematoma connected to the radial artery was detected with ultrasound. Surgical intervention with the removal of multiple, sterile clots from the hematoma was performed, and the multiple lacerations of the artery detected were corrected. This is the first case reporting rupture of the radial artery as a complication of infective endocarditis.
Pullback𝒟-Attractor of Nonautonomous Three-Component Reversible Gray-Scott System on Unbounded Domains
Authors: Gu Anhui
Published: September 2013

The long time behavior of solutions of the nonautonomous three-components reversible Gray-Scott system defined on the entire spaceℝnis studied when the external forcing terms are unbounded in a phase space. The existence of a pullback global attractor for the equation is established inL2ℝn3andH1ℝn3, respectively. The pullback asymptotic compactness of solutions is proved by using uniform estimates on the tails of solutions on unbounded domains.
JIS Definition Identified More Malaysian Adults with Metabolic Syndrome Compared to the NCEP-ATP III and IDF Criteria
Authors: Ramli Anis Safura , Daher Aqil Mohammad , Noor Khan Nor-Ashikin Mohamed , Mat-Nasir Nafiza , Keat Ng Kien , Miskan Maizatullifah , Ambigga Krishnapillai S. , Ariffin Farnaza , Yasin Mazapuspavina Md , Abdul-Razak Suraya , Abdul-Hamid Hasidah , Abd-Majid Fadhlina , Abu-Bakar Najmin , Nawawi Hapizah , Yusoff Khalid
Published: September 2013

Metabolic syndrome (MetS) is a steering force for the cardiovascular diseases epidemic in Asia. This study aimed to compare the prevalence of MetS in Malaysian adults using NCEP-ATP III, IDF, and JIS definitions, identify the demographic factors associated with MetS, and determine the level of agreement between these definitions. The analytic sample consisted of 8,836 adults aged ≥30 years recruited at baseline in 2007–2011 from the Cardiovascular Risk Prevention Study (CRisPS), an ongoing, prospective cohort study involving 18 urban and 22 rural communities in Malaysia. JIS definition gave the highest overall prevalence (43.4%) compared to NCEP-ATP III (26.5%) and IDF (37.4%),P<0.001. Indians had significantly higher age-adjusted prevalence compared to other ethnic groups across all MetS definitions (30.1% by NCEP-ATP III, 50.8% by IDF, and 56.5% by JIS). The likelihood of having MetS amongst the rural and urban populations was similar across all definitions. A high level of agreement between the IDF and JIS was observed (Kappa index = 0.867), while there was a lower level of agreement between the IDF and NCEP-ATP III (Kappa index = 0.580). JIS definition identified more Malaysian adults with MetS and therefore should be recommended as the preferred diagnostic criterion.
The Fold Variant BM4 Is Beneficial in a Therapeutic Bet v 1 Mouse Model
Authors: Pichler Ulrike , Asam Claudia , Weiss Richard , Isakovic Almedina , Hauser Michael , Briza Peter , Ferreira Fatima , Wallner Michael
Published: September 2013

Background. Specific immunotherapy using recombinant allergens is clinically effective; still wild-type allergens can provoke treatment-induced side effects and often show poor immunogenicityin vivo. Thus, we tested the low IgE-binding, highly immunogenic fold variant BM4 in a Bet v 1 mouse model.Methods. Recombinant BM4 was used as active vaccine ingredient to treat mice sensitized to Bet v 1. As controls, mice were treated with either Bet v 1 or sham, and the humoral as well as cellular immune response was monitored. Moreover, lung function and lung inflammation were analysed.Results. BM4 was more effective than wild-type Bet v 1 in inducing Bet v 1-specific blocking antibodies as well as IFN-γand IL-10 producing T cells. Further, birch pollen induced lung inflammation could be ameliorated significantly by BM4 treatment as demonstrated by a reduction of airway hyperresponsiveness and drastically decreased eosinophil counts in bronchoalveolar lavage fluids.Conclusion. The study outlines the high potential of BM4 as vaccine candidate for the treatment of Bet v 1-mediated birch pollen allergies.
Performativity and affectivity
Authors: Edgington Ursula
Published: September 2013

Teaching and learning observations (TLOs) are used in educational environments worldwide to measure and improve quality and support professional development. TLOs can be positive for teachers who enjoy opportunities to ‘perform’ their craft and/or engage in professional dialogue. However, if this crucial, collaborative developmental element is missing, a TLO becomes intrinsically evaluative in nature and creates complex emotions – within and beyond the classroom. For some teachers, affective reactions to perceived managerial intrusion into their professional space has a negative impact on them and, in turn, their students’ learning. International research on TLOs has focused on schools or universities. My research centres specifically on England’s Further Education colleges (FE). Through Interpretive Interactionism, I investigate the different expectations, relationships and identities of teachers and (mis)conceptions of ‘authenticity’ in TLOs. Teaching involves our unique (dis)embodied ‘performativity’ (Butler, 2004) or ‘emotional practice’, which is interpreted and judged by others (Denzin, 1989). Using the concept of ‘aesthetic labour’ (Witz et al., 2003), I argue that rather than promoting positive transformation through reflection, TLOs promote a rejection of emotional ‘genuineness’ which causes anxiety through a fracturing of personal and professional identities. Improving the effectiveness of TLOs should perhaps encompass explicit dialogue about the affectivity involved in the process?
Leading charters
Authors: Carpenter Dick Michael , Peak Charity
Published: September 2013

Charter schools have been studied from numerous perspectives. One topic that remains under-researched, however, is charter school leadership. Therefore, we examine how charter administrators define their leadership roles and their ability to lead. Results indicate that charter principals see three primary functions in their leadership—building and moving the internal school community in a common direction, managing staff, and school safety. Charter school principals expressed general confidence in their ability to lead in these areas but less confidence in leading in the areas of math and literacy. Charter leaders spend more time conducting meetings and handling parent issues and less time on hiring staff and fundraising. Finally, time differential statistics revealed that, although principals recognize the value of instructional leadership, less time than desired is spent on this area. Implications from the research indicate that charter boards and aspiring leaders should pay attention to alignment between how each defines leadership and what each party expects of the role.
Towards a new privacy
Authors: Hanley Christopher
Published: September 2013

This article reviews some leadership and management literature dealing with emotional demands in professional contexts. An image of the ‘real self’, requiring emotional privacy, is highly valued by individuals subjected to intense emotional demands. It is argued that the ‘real self’ and emotional privacy ought to be defended against emotional ‘totalitarianism’ at work in high performance education contexts.

The writings of George Orwell are employed both to develop an understanding of totalitarianism and consider how it can be resisted. Orwell prized the ideal of the ‘real self’, and it is argued that recent management literature does not give sufficient consideration to understanding and protecting ‘private’ emotions. It is argued that management discourse, demanding increasing levels of ‘emotional labour’, might be working from an imperfect or incomplete understanding of emotional experience as it is actually lived. An analysis of an article from The Academy of Management Review exemplifies managerial preoccupation with emotional effectiveness, without considering how such effectiveness connects with other life contexts.

Ideas taken from Orwell are proposed to develop and fortify an ideal of emotional privacy, making explicit links between emotions and the society in which emotions are nurtured and understood.
A powerful latent variable method for detecting and characterizing gene-based gene-gene interaction on multiple quantitative traits
Authors: Li Fangyu , Zhao Jinghua , Yuan Zhongshang , Zhang Xiaoshuai , Ji Jiadong , Xue Fuzhong
Published: September 2013

Background

On thinking quantitatively of complex diseases, there are at least three statistical strategies for analyzing the gene-gene interaction: SNP by SNP interaction on single trait, gene-gene (each can involve multiple SNPs) interaction on single trait and gene-gene interaction on multiple traits. The third one is the most general in dissecting the genetic mechanism underlying complex diseases underpinning multiple quantitative traits. In this paper, we developed a novel statistic for this strategy through modifying the Partial Least Squares Path Modeling (PLSPM), called mPLSPM statistic.

Results

Simulation studies indicated that mPLSPM statistic was powerful and outperformed the principal component analysis (PCA) based linear regression method. Application to real data in the EPIC-Norfolk GWAS sub-cohort showed suggestive interaction (γ) between TMEM18 gene and BDNF gene on two composite body shape scores (γ = 0.047 and γ = 0.058, with P = 0.021, P = 0.005), and BMI (γ = 0.043, P = 0.034). This suggested these scores (synthetically latent traits) were more suitable to capture the obesity related genetic interaction effect between genes compared to single trait.

Conclusions

The proposed novel mPLSPM statistic is a valid and powerful gene-based method for detecting gene-gene interaction on multiple quantitative phenotypes.