bluuebunny/crossref_metadata_2025 huggingface dataset:
USABILITY EVALUATION OF DIGITAL MALAYSIAN TRADITIONAL GAMES
Authors: ChePa Noraziah , Abu Bakar Nur Azzah , Mohd Azizudin
Published: December 2015

Focusing on measuring the engagement towards digital Malaysian traditional games, this paper presents usability evaluation on three digital versions of Malaysian traditional games; Dam Haji, Congkak and Gasing-X. Usability is a significant contributing factor towards engagement of digital games. Usability helps in verifying the requirements, successes and functionality of the games which are missing. The usability evaluation adopted the heuristic instruments developed by Jakob Nielson in 1990. The instrument consists of 17 heuristic component protocols based on interface design. Evaluation involved 50 respondents who are IT and domain experts. Result analysis is discussed and presented for each game. Results suggested features and aspects to be improved in the development of Digital Malaysian Traditional Games towards better engagement of the games.
THE PERFORMANCE AND SIGNIFICANCE OF ISLAMIC REITs IN A MIXED-ASSET PORTFOLIO
Authors: Rozman Ahmad Tajjudin , Azmi Nurul Afiqah , Mohd. Ali Hishamuddin , Mohamed Razali Muhammad Najib
Published: December 2015

Islamic Real Estate Investment Trusts (I-REITs) have been established to enhance the Islamic Capital Market. Almost 10 years of establishment of I-REITs, it is interesting to study the performance of this Islamic property investment vehicle because it is a potential and unique asset class that not fully explored. This paper examines the risk-adjusted performance analysis and correlation analysis between I-REITs in a mixed asset portfolio. The time period of study is from November 2008 to December 2014. I-REITs were compare in a mixed asset portfolio consists of shares and bonds. The results show that I-REITs outperform both shares market and bonds market. While I-REITs give high diversification benefits for the share and bond investors with low correlation between I-REITs, shares and bonds.
A CFD SIMULATION OF PM1 AND CO AIR CONTAMINANTS IN A BUS PASSENGER COMPARTMENT
Authors: Ahmad Shafie Noor Emilia , Mohamed Kamar Haslinda , Kamsah Nazri
Published: December 2015

Air distribution systems inside a bus compartment are important for providing healthy and comfortable environment for passengers. Lack of ventilation inside the bus passenger compartment causes an increase level of air contaminants concentration. Particulate matters and carbon monoxide are indoor air contaminants which can affect the passenger’s health such as respiratory problem and lung cancer. This article reports the results of a CFD simulation on transport of carbon monoxide and particulate matter 1 inside a passenger compartment of a university’s shuttle bus. Fluent CFD software was used to develop a simplified three-dimensional model of the bus passenger compartment. Flow analysis was carried out using RNG k-e turbulent model for air flow, discrete phase and species transport for the air contaminants. Four variations of ventilation system namely two mixing ventilation types, combined mixing with displacement ventilation and combined mixing ventilation with underfloor air distribution was examined. The CFD simulation results show that the use of the combined mixing and displacement ventilation and also the combined mixing and underfloor ventilation types are capable of reducing the concentration of carbon monoxide and particulate matter 1 inside the bus passenger compartment by 81% and 54%, respectively.
APPLICATION OF THERMAL ENERGY STORAGE SYSTEM FOR A LOWLAND GREENHOUSE
Authors: Mohamed Kamar Haslinda , Kamsah Nazri , Norull Azman Norull Ahmad
Published: December 2015

This article presents a study to estimate the potential saving in annual operating cost of a hypothetical greenhouse used for planting strawberry, in Johor Bahru, Malaysia. The greenhouse needs to be maintained at a constant temperature of 20°C at all time. The goal of this study is to select a suitable TES system that can save the annual cost of electricity usage to meet the cooling load requirement of the greenhouse, based on a 24 hours operating duration and local electricity tariff. Comparison is made with the annual cost for running a conventional air-conditioning (AC) system to meet the cooling requirement. The cooling load requirement of the greenhouse dictates the capacity and size of the potential TES systems, which was estimated based on the highest total annual cooling load. Three TES system operating arrangements were considered in this study: TES full storage combined with AC systems, TES full storage and TES partial storage. Among these three arrangements, the TES full storage was found to have the highest an annual cost saving of about RM 58,990 compared to the cost of using the conventional AC system alone. This represents about 68 % of annual operating cost saving, which is considered very significant.
ASSESSMENT OF AQUATIC ECOSYSTEM STATUS USING MACROPHYTE SPECIES AS KEY TOOLS INDICATOR FOR HEAVY METAL POLLUTION
Authors: Othman Rashidi , Shaharuddin Ruhul Izzati , Baharuddin Zainul Mukrim , Hashim Khairusy Syakirin Has-Yun , Irani Hasni Mohd Shah
Published: December 2015

Aquatic plants or macrophytes are beneficial to fresh water bodies because they produce oxygen, which assists with overall fresh water bodies functioning, and provide food and shelter for aquatic living organisms. A lack of aquatic plants in a freshwater bodies system where they are expected to occur may suggest a reduced population of macro and micro fauna. In addition, the absence of macrophytes may also indicate water quality problems as a result of excessive turbidity, herbicides, or salinization. However, an over abundance of macrophytes can result from high nutrient levels and may interfere with freshwater bodies processing, recreational activities and detract from the aesthetic appeal of the system. In this study, sixteen water samples were collected from four different places (Selangor, Perak, Pahang and Kelantan) where six different macrophytes species were abundance and dominant. All the water samples were analyzed by using Atomic absorption spectroscopy (AAS) for six types of heavy metals which are iron (Fe), lead (Pb), copper (Cu), zinc (Zn), nickel (Ni) and manganese (Mn). All six different macrophytes species which are Eichhorniacrassipes, Hydrillaverticillata, Cabombafuscata, Salvinianatans, Nelumbonuciferaand Pistiastratiotesexhibiting highly significant differences (P< 0.0001) between aquatic plant species widespread, locations and the heavy metals content. This clearly demonstrates that freshwater environment with abundance of invasive macrophyte species can have an important influence and indication on the accumulation of heavy metals content. The importance of the interaction components emphasises that the changes in heavy metals composition are complex and the responses are not consistent across all aquatic plant species. Examination of the summarised data revealed that, of the 6 macrophyte species analysed at all different locations, all exhibits as potential ecological indicator for unhealthy aquatic ecosystems or as phytoindicator for heavy metal contaminants either at low or high level contamination. Therefore, macrophyte is an effective tool in responding heavy metal in low level environmental contamination that might otherwise be difficult to detect.
SIMULATION OF ORGANIC RANKINE CYCLE THROUGH FLUEGAS TO LARGE SCALE ELECTRICITY GENERATION PURPOSE
Authors: Rowshanaie Omid , Mustapha Saari , Ahmad Kamarul Arifin , Rowshanaie Hooman
Published: December 2015

A simulation model of Organic Rankine Cycle (ORC) was developed with HYSYS software driven by R245fa, with NOVEC7000 and R141b as working fluids and Fluegas of boilers as a heat source of shell and tube Heat Exchanger to generate large scale electricity. The initial working condition was in subcooled liquid and steady state condition. R141b was found to generate the highest electricity power increment in specific mass flow rates and inlet pressures of Expander because of approaching its critical temperature to inlet Fluegas temperature. Howeever, in terms of economic considerations and cost of shell and tube Heat Exchanger that related to total heat transfer capacity, NOVEC7000 is the optimum selection. Furthermore, R245fa has the highest total effiiciency of ORC compared with other working fluids in this study.
A SYSTEMATIC REVIEW OF INTERVENTION TO REDUCE MUSCULOSKELETAL DISORDERS: HAND AND ARM DISORDERS
Authors: Alias Ayuni Nabilah , Karuppiah Karmegam , Mohd Tamrin Shamsul Bahri , Zainal Abidin Emilia , Mohd Shafiei Umi Kalsom
Published: December 2015

Despite with countless number of incidence related to musculoskeletal disorders among workers, there are lot of studies that come out with interventions in order to reduce musculoskeletal disorders. Musculoskeletal disorders continue to give a large impact and challenge towards employer and employee in many different sectors. This article had reviewed the literature that related to intervention to reduce musculoskeletal disorders of the hand and arm. 5 databases were reviewed to identify studies related to intervention to reduce musculoskeletal disorders of the hand and arm among workers. In order to identify and classify research studies, specific keywords (ergonomic, musculoskeletal disorder, hand and arm disorders, occupation, injury, intervention and prevention) were identified and used in a systematic search to guide the discovery of relevant studies. Included studies were reviewed and interventions were assessed. As overall, 312 titles were discovered during the search and only 6 studies that were related to hand and arm disorders and met inclusion criteria. Within these 6 studies, this review identified ergonomic interventions in terms of training, program and workstation redesign. The positive outcomes after the implementation of these interventions, there were significant reduction related to hand and arm disorders among workers. As conclusion, interventions that had been implemented in these 6 studies and significant reduction of musculoskeletal disorders, there is need to do further research in order to propose ergonomic designs for the workers in workplace
SOFT LEAN PRACTICES FOR SUCCESSFUL LEAN PRODUCTION SYSTEM IMPLEMENTATION IN MALAYSIA AUTOMOTIVE SMES: A PROPOSED FRAMEWORK
Authors: Che Mamat Rusalbiah , Md Deros Baba , Ab Rahman Mohd Nizam , Khalil Omar Muhamad , Abdullah Shukriah
Published: December 2015

Challenging and competitive business environment has prompted the automotive industry to restructure its manufacturing practices. Nowadays, Lean Manufacturing (LM) has been widely implemented in the automotive industry. LM supported the manufacturing companies, particularly automotive manufacturers in becoming world class manufacturers through various lean practices. However, lean implementation faced various obstacles such as the lack of management commitment and support, the absence of organizational communication, employees’ attitude and many more. It is also indicated that lean implementation success factors are not merely due to technical practices but also with the integration of non-technical aspects such as human-related practices. This paper aims to investigate the Soft Lean Practices that are necessary for the successful implementation of the Lean Production System (LPS) in the Malaysian Automotive SMEs. The result of this paper will provide a detailed review of Soft Lean Practices within the LM literature that should be considered by the organizations when implementing lean. A framework was also developed through an extensive review of Soft Lean literature.
ISOLATION AND CHARACTERIZATION POLYHYDROBUTYRATE (PHB) PRODUCING BACTERIA FROM WASTE COOKING OIL USING POMEGRANATE MOLASSES AS CARBON SOURCE
Authors: Muftah Zargoun Laila , Mohd Zain Nor Azimah , Shahir Shafinaz
Published: December 2015

In this study, a polyhydroxybutyrate (PHB) producing bacterium was isolated from waste cooking oil and characterized for its morphological and biochemical properties. Staining methods utilizing Sudan Black B and Nile Blue A were used on isolated bacterium to demonstrate good capability for synthesizing PHB. It was shown that the isolated bacterium species was related to Bacillus thuringiensis LMA by using 16S rRNA gene sequences analysis. During the stationary phase, the Bacillus strain was subjected to 10 % (w/v) of pomegranate molasses as a carbon source and 5 g/L of peptone as a nitrogen source. 2 ml of batch fermentation was collected. Samples were collected twice during the incubation period for detection of PHB using Sudan Black B. The PHB production accounted for up to 57.45% of the cell dry weight. The PHB produced was characterized using Fourier Transform Infrared Spectroscopy (FTIR) and Nuclear Magnetic Resonance Spectroscopy (NMR). The drastic absorption band at approximately 1717 cm-1 indicated the stretching vibration of C=O group in PHB polyester, while the functional groups of PHB were identified methyl (-CH3) at 1.28 ppm, methylene (-CH2) 2.0 and 2.5 ppm, and methylene doublet group (CH3) at 5.3 ppm.
Electrostatic modeling of an in-plane gated field emission cathode
Authors: Sabaut Lucie , Ponard Pascal , Mazellier Jean-Paul , Legagneux Pierre
Published: December 2015

In this study, the authors develop an electrostatic model for an in-plane gated field emission cathode. This structure is based on two electrodes lying on the same plane. One electrode (bias electrode) allows biasing the field emitter element, a whisker in present study. The other electrode (gate electrode) is being used to electrostatically control the system. Our model points out the main geometrical parameters to be bias electrode characteristic size and whisker height, as confirmed by simulations. This model gives access to the extraction field experienced by the whisker emitter on its apex, in turn giving access to emission current dependencies on the various parameters of the model. The proximity of the gate as compared to the emitter apex enables low bias voltage to modulate the current with high susceptibility.
Optimizing swept-tone protocols for recording distortion-product otoacoustic emissions in adults and newborns
Authors: Abdala Carolina , Luo Ping , Shera Christopher A.
Published: December 2015

Distortion-product otoacoustic emissions (DPOAEs), which are routinely used in the audiology clinic and research laboratory, are conventionally recorded with discrete tones presented sequentially across frequency. However, a more efficient technique sweeps tones smoothly across frequency and applies a least-squares-fitting (LSF) procedure to compute estimates of otoacoustic emission phase and amplitude. In this study, the optimal parameters (i.e., sweep rate and duration of the LSF analysis window) required to record and analyze swept-tone DPOAEs were tested and defined in 15 adults and 10 newborns. Results indicate that optimal recording of swept-tone DPOAEs requires use of an appropriate analysis bandwidth, defined as the range of frequencies included in each least squares fit model. To achieve this, the rate at which the tones are swept and the length of the LSF analysis window must be carefully considered and changed in concert. Additionally, the optimal analysis bandwidth must be adjusted to accommodate frequency-dependent latency shifts in the reflection-component of the DPOAE. Parametric guidelines established here are equally applicable to adults and newborns. However, elevated noise during newborn swept-tone DPOAE recordings warrants protocol adaptations to improve signal-to-noise ratio and response quality.
Built Environment and Walking Behavior Among Brazilian Older Adults: A Population-Based Study
Authors: Giehl Marui Weber Corseuil , Hallal Pedro Curi , Corseuil Claudia Weber , Schneider Ione J. Ceola , d’Orsi Eleonora
Published: December 2015

Background:

Understanding the built environment influence on specific domains of walking is important for public health interventions to increase physical activity levels among older adults.

Purpose:

The purpose was to investigate the association between built environment characteristics and walking among older adults.

Methods:

A population-based study was performed in 80 census tracts in Florianópolis, Brazil, including 1,705 older adults (60+ years old). Walking was measured using the International Physical Activity Questionnaire. Built environment characteristics were assessed through a geographic information system. All analyses were conducted through a multilevel logistic regression.

Results:

Individuals living in neighborhoods with a higher population density (odds ratio [OR]: 2.19; 95% confidence interval [CI], 1.40–3.42), with a higher street connectivity (OR: 1.85; 95% CI, 1.16–2.94), a higher sidewalk proportion (OR: 1.77; 95% CI, 1.11–2.83), and paved streets (medium tertile: OR: 1.61, 95% CI, 1.04–2.49; highest tertile: OR: 2.11; 95% CI, 1.36–3.27) were more likely to walk for transportation. Regarding walking for leisure, only 2 predictors were associated, area income (OR: 1.48; 95% CI, 1.04–2.12) and street density (OR: 1.47; 95% CI, 1.02–2.10).

Conclusions:

Improving the neighborhood built environment is an important step for achieving higher levels of walking in the elderly population in a middle-income country.
Two cases of small bowel obstruction secondary to a swallowed potato
Authors: Castren E , Hakeem A , Mahmood N S , Aryal K
Published: December 2015

Bowel obstruction due to bezoars (compaction of ingested material within the gastrointestinal tract) is a rare, but well documented occurrence. In this paper, we present two cases of potato-induced small bowel obstruction. Both patients were approximately 50 years old and had cerebral palsy and learning disabilities, respectively. They presented with abdominal pain and bilious vomiting, with no medical or surgical history. Diagnosis of small bowel obstruction was confirmed by CT prior to taking the patients to the operating theatre, where whole potatoes were found to be obstructing each patient's bowel lumen. Both patients underwent laparotomy with enterotomy and removal of the potato. They both made a good recovery. Through a literature review of bezoar-induced bowel obstruction, these cases highlight important diagnostic and management principles.
Use of hospital resources in the Finnish colorectal cancer screening programme: a randomised health services study
Authors: Mäklin Suvi , Hakama Matti , Rissanen Pekka , Malila Nea
Published: December 2015

Objective

To estimate the difference in use of hospital resources in the Finnish Colorectal Cancer (CRC) screening programme between those invited and controls, within the year of randomisation and the next year.

Design

CRC screening was implemented in Finland in 2004 as a population-based randomised design using biennial faecal occult blood test (FOBT) for men and women aged 60–69 years. Those randomised to screening and control groups during years 2004–2009 were included in this analysis and use of hospital resources was estimated. Data were collected from the national register on hospital discharges. Outpatient visits, inpatient episodes and colonoscopies were compared between the two groups.

Results

The screening group comprised of 123 149 and control group of 122 930 people. Most people in both groups had not used hospital resources at all. More people in the screening group than in the control group had at least one hospital-based outpatient visit (7.8% vs 7.4%), inpatient episode (3.9% vs 3.8%) and colonoscopy (1.5% vs 1.3%). In total, the screening group had 31 975 and control group 27 061 cumulative outpatient visits, 9260 and 7903 inpatient episodes, and 2686 and 1756 hospital colonoscopies, respectively. The proportion of those with a positive FOBT result with at least one outpatient visit, one inpatient episode or one colonoscopy, was 3.7 times, 2.5 times or 9 times that of those with a negative FOBT result, respectively.

Conclusions

CRC screening using the FOBT slightly increased the volume of hospital outpatient visits, inpatient episodes and hospital colonoscopies in Finland.
Hydromechanical behaviour of unsaturated soil with different specimen preparations
Authors: Gao You , Sun De’an , Zhou Annan
Published: December 2015

The effect of different specimen preparation methods (compaction, reconstitution) on the hydromechanical behaviour and microstructure of soil was studied through a series of soil-water retention tests, triaxial tests, and mercury intrusion porosimetry (MIP) tests on an unsaturated clayey silt. Key findings from this experimental study include the following. (i) The air-entry value of the reconstituted specimen is higher than that of the compacted specimen with the same initial void ratio. (ii) The reconstituted specimen exhibits a unimodal pore-size distribution and the compacted specimen exhibits a bimodal pore-size distribution, according to results of the MIP tests. (iii) The soil-water characteristic curves and residual gravimetric water content of compacted and reconstituted specimens are almost the same in the high suction range. (iv) The void ratio of a reconstituted specimen decreases sharply with increasing suction value under an isotropic net stress (such as 20 kPa), while the void ratio of a compacted specimen shows a small change for the same suction change process. (v) Under the same net confining pressure, the shear strength of both compacted and reconstituted specimens increases with the suction increase. The shear strength of the reconstituted specimen is higher than that of the compacted specimen with the same density under the same suction and net confining pressure.
Growth property at infinity of the maximum modulus with respect to the Schrödinger operator
Authors: Huang Jinjin
Published: December 2015

In this paper, we consider the growth property at infinity of the maximum modulus with respect to the Schrödinger operator in a cone, which supplement Phragmén–Lindelöf theorems for subfunctions obtained by Qiao and Pan (Generalization of the Phragmén–Lindelöf theorems for subfunctions, Internat. J. Math. 24 (2013) Article ID: 1350062).
Green matrices and continuity of the weak solutions for the elliptic systems with lower order terms
Authors: Zhuge Jinping , Zhang Zhenqiu
Published: December 2015

In this paper, we consider the second-order elliptic systems with lower order terms coefficients belonging to Kato–Stummel type classes in a bounded domain [Formula: see text], where [Formula: see text]. We establish the existence, global pointwise estimates and [Formula: see text] estimates for Green matrices. Based on these estimates, we are able to show the continuity of weak solutions for the general elliptic systems by using method of potentials. We also obtain the optimal Schauder estimates for weak solutions.
Cluster modified projective synchronization between networks with distinct topologies
Authors: Vahedi Shahed , Noorani Mohd Salmi Md
Published: December 2015

Cluster modified projective synchronization (CMPS) between two topologically distinct community networks is studied in this paper. Each cluster here has a unique dynamics at least with respect to the parameter sets. Using an adaptive feedback control gain and a matrix scaling factor, we show that CMPS between two community networks can be realized with considering minimum assumptions and imposing just few restrictions on the configuration set. We use Lyapunov stability theory for the proof and employ computer simulation to confirm our result on randomly generated community networks. Simulations also show the possibility of having hybrid synchronization between the two networks.
A multiple relaxation time extension of the constant speed kinetic model
Authors: Zadehgol Abed , Ashrafizaadeh Mahmud
Published: December 2015

In this work, a multiple relaxation time (MRT) extension of the recently introduced constant speed kinetic model (CSKM) is proposed. The CSKM, which is an entropic kinetic model and based on unconventional entropies of Burg and Tssalis, was introduced in [A. Zadehgol and M. Ashrafizaadeh, J. Comput. Phys. 274, 803 (2014)]; [A. Zadehgol Phys. Rev. E 91, 063311 (2015)] as an extension of the model of Boghosian et al. [Phys. Rev. E 68, 025103 (2003)] in the limit of fixed speed continuous velocities. The present extension improves the stability of the previous models at very high Reynolds numbers, while allowing for a more convenient orthogonal lattice. The model is verified by solving the following benchmark problems: (i) the lid driven square cavity and (ii) the Kelvin–Helmholtz instability of thin shear layers in a doubly periodic square domain.
Holonomy, quantum mechanics and the signal-tuned Gabor approach to the striate cortex
Authors: Torreão José R. A.
Published: December 2015

It has been suggested that an appeal to holographic and quantum properties will be ultimately required for the understanding of higher brain functions. On the other hand, successful quantum-like approaches to cognitive and behavioral processes bear witness to the usefulness of quantum prescriptions as applied to the analysis of complex non-quantum systems. Here, we show that the signal-tuned Gabor approach for modeling cortical neurons, although not based on quantum assumptions, also admits a quantum-like interpretation. Recently, the equation of motion for the signal-tuned complex cell response has been derived and proven equivalent to the Schrödinger equation for a dissipative quantum system whose solutions come under two guises: as plane-wave and Airy-packet responses. By interpreting the squared magnitude of the plane-wave solution as a probability density, in accordance with the quantum mechanics prescription, we arrive at a Poisson spiking probability — a common model of neuronal response — while spike propagation can be described by the Airy-packet solution. The signal-tuned approach is also proven consistent with holonomic brain theories, as it is based on Gabor functions which provide a holographic representation of the cell’s input, in the sense that any restricted subset of these functions still allows stimulus reconstruction.
Top physics at the LHC
Authors: Del Duca Vittorio , Laenen Eric
Published: December 2015

We review the present situation in top quark physics, in these early days of Run II of the LHC. We take mostly a Standard Model perspective, showing recent results, and review the key concepts and results of the associated theoretical predictions. The issues we discuss are the top quark mass, top quark pair and single top production, production in association with other particles, charge asymmetry and top quark decay.
Optimal engine performance using inference for non-identical finite source and sink
Authors: Aneja Preety , Katyayan Harsh , Johal Ramandeep S.
Published: December 2015

We quantify the prior information to infer the optimal characteristics for a constrained thermodynamic process of maximum work extraction for a pair of non-identical finite systems. The total entropy of the whole system remains conserved. The ignorance is assumed about the final temperatures of the finite systems and then a prior distribution is assigned to the unknown temperatures. We derive the estimates of efficiency for this reversible model of heat engine with incomplete information. The estimates show good agreement with efficiency at optimal work for arbitrary sizes of systems, however the estimates become exact when one of the reservoir becomes very large in comparison to the other.
A mixed-primal finite element approximation of a sedimentation–consolidation system
Authors: Alvarez Mario , Gatica Gabriel N. , Ruiz-Baier Ricardo
Published: December 2015

This paper is devoted to the mathematical and numerical analysis of a strongly coupled flow and transport system typically encountered in continuum-based models of sedimentation–consolidation processes. The model focuses on the steady-state regime of a solid–liquid suspension immersed in a viscous fluid within a permeable medium, and the governing equations consist in the Brinkman problem with variable viscosity, written in terms of Cauchy pseudo-stresses and bulk velocity of the mixture; coupled with a nonlinear advection — nonlinear diffusion equation describing the transport of the solids volume fraction. The variational formulation is based on an augmented mixed approach for the Brinkman problem and the usual primal weak form for the transport equation. Solvability of the coupled formulation is established by combining fixed point arguments, certain regularity assumptions, and some classical results concerning variational problems and Sobolev spaces. In turn, the resulting augmented mixed-primal Galerkin scheme employs Raviart–Thomas approximations of order [Formula: see text] for the stress and piecewise continuous polynomials of order [Formula: see text] for velocity and volume fraction, and its solvability is deduced by applying a fixed-point strategy as well. Then, suitable Strang-type inequalities are utilized to rigorously derive optimal error estimates in the natural norms. Finally, a few numerical tests illustrate the accuracy of the augmented mixed-primal finite element method, and the properties of the model.
A Study on Theoretical Performance of Graphene FET using Analytical Approach with Reference to High Cutoff Frequency
Authors: Fahim-Al-Fattah Md. , Rahman Md. Tawabur , Islam Md. Sherajul , Bhuiyan Ashraful G.
Published: December 2015

This paper presents a detailed study of theoretical performance of graphene field effect transistor (GFET) using analytical approach. GFET shows promising performance in terms of faster saturation as well as extremely high cutoff frequency (3.9[Formula: see text]THz). A significant shift of the Dirac point as well as an asymmetrical ambipolar behavior is observed on the transfer characteristics. Similarly, an approximate symmetrical capacitance–voltage (C–V) characteristics is obtained where it has guaranteed the consistency because it shows a significant saturation both in the accumulation and inversion region. In addition, a high transconductance of 6800[Formula: see text]uS at small channel length (20[Formula: see text]nm) along with high cutoff frequency (3.9[Formula: see text]THz) has been observed which demands for high speed field effect devices.
Knowledge Geometry
Authors: de Mello Flávio Luis , de Carvalho Roberto Lins
Published: December 2015

This paper aims to present what we call knowledge geometry, an alternative theory for spatial representation of features related to information processing, information management, and knowledge management. It is a unique geometric approach for representing intuition, reification, interpretation, and deduction processes, as well as their relations. We employ the concept of cultural filter and use what we call real, conceptual, and symbolic planes in order to support transformations which occur along the perception of a phenomenon. After that, we discuss the use of evaluation systems to judge concepts and also the use of semantic systems as a communication language. Finally, a framework of the knowledge acquisition process in the field of the proposed theory is offered, proving the feasibility of its automation.
A Two-parameter bicovariant differential calculus on the (1 + 2)-dimensional q-superspace
Authors: Yasar Ergün
Published: December 2015

We construct a two-parameter bicovariant differential calculus on [Formula: see text] with the help of the covariance point of view using the Hopf algebra structure of [Formula: see text]. To achieve this, we first use the consistency of calculus and the approach of [Formula: see text]-matrix which satisfies both ungraded and graded Yang–Baxter equations. In particular, based on this differential calculus, we investigate Cartan–Maurer forms for this [Formula: see text]-superspace. Finally, we obtain the quantum Lie superalgebra corresponding the Cartan–Maurer forms.
A note on teleparallel conformal Killing vector fields in plane symmetric non-static spacetimes
Authors: Khan Suhail , Hussain Tahir , Khan Gulzar Ali
Published: December 2015

The aim of this paper is to investigate teleparallel conformal Killing vector fields (CKVFs) in plane symmetric non-static spacetimes. Ten teleparallel conformal Killing’s equations are obtained which are linear in the components of the teleparallel CKVF [Formula: see text]. A general solution of these equations comprising the components of CKVF and conformal factor is presented, which subject to some integrability conditions. For seven particular choices of the metric functions, the integrability conditions are completely solved to get the final form of teleparallel CKVFs and conformal factor. In four different cases we get proper CKVFs, while in the remaining three cases it is shown that teleparallel CKVFs reduce to teleparallel homothetic or teleparallel Killing vector fields.
Statistical analysis and modeling of residential buildings for artificial Beijing reconstruction
Authors: Song Zhi-Chao , Meng Rong-Qing , Duan Hong , Qiu Xiao-Gang
Published: December 2015

Environment model is an important component of an artificial society. To level up the resolution of residence-building environment models in artificial Beijing, we divide residential buildings in Beijing into two categories, which are noncommunity residential buildings and community residential buildings, and statistically analyze the numbers of floors and areas of the real residential buildings. In this paper, we have exhibited the distribution of numbers of floors in noncommunity residential buildings and community residential buildings. Furthermore, we analyze the distribution of areas of noncommunity residential buildings and residence-use proportions of community zones by Nonlinear Regression. Results indicate that areas of noncommunity residential buildings in Beijing obey the log-normal distribution and residence-use proportions of community zones obey normal distribution. According to the statistical models, the virtual residential buildings in artificial Beijing can be endowed with rational attribute values.
Where code comes from
Authors: Haigh Thomas , Priestley Mark
Published: December 2015

Considering the evolving concept of programming.
Automatic scalable atomicity via semantic locking
Authors: Golan-Gueta Guy , Ramalingam G. , Sagiv Mooly , Yahav Eran
Published: December 2015

In this paper, we consider concurrent programs in which the shared state consists of instances of linearizable ADTs (abstract data types). We present an automated approach to concurrency control that addresses a common need: the need to atomically execute a code fragment, which may contain multiple ADT operations on multiple ADT instances. We present a synthesis algorithm that automatically enforces atomicity of given code fragments (in a client program) by inserting pessimistic synchronization that guarantees atomicity and deadlock-freedom (without using any rollback mechanism). Our algorithm takes a commutativity specification as an extra input. This specification indicates for every pair of ADT operations the conditions under which the operations commute. Our algorithm enables greater parallelism by permitting commuting operations to execute concurrently. We have implemented the synthesis algorithm in a Java compiler, and applied it to several Java programs. Our results show that our approach produces efficient and scalable synchronization.
On optimizing machine learning workloads via kernel fusion
Authors: Ashari Arash , Tatikonda Shirish , Boehm Matthias , Reinwald Berthold , Campbell Keith , Keenleyside John , Sadayappan P.
Published: December 2015

Exploitation of parallel architectures has become critical to scalable machine learning (ML). Since a wide range of ML algorithms employ linear algebraic operators, GPUs with BLAS libraries are a natural choice for such an exploitation. Two approaches are commonly pursued: (i) developing specific GPU accelerated implementations of complete ML algorithms; and (ii) developing GPU kernels for primitive linear algebraic operators like matrix-vector multiplication, which are then used in developing ML algorithms. This paper extends the latter approach by developing fused kernels for a combination of primitive operators that are commonly found in popular ML algorithms. We identify the generic pattern of computation (alpha * X^T (v * (X * y)) + beta * z) and its various instantiations. We develop a fused kernel to optimize this computation on GPUs -- with specialized techniques to handle both sparse and dense matrices. This approach not only reduces the cost of data loads due to improved temporal locality but also enables other optimizations like coarsening and hierarchical aggregation of partial results. We also present an analytical model that considers input data characteristics and available GPU resources to estimate near-optimal settings for kernel launch parameters. The proposed approach provides speedups ranging from 2 to 67 for different instances of the generic pattern compared to launching multiple operator-level kernels using GPU accelerated libraries. We conclude by demonstrating the effectiveness of the approach in improving end-to-end performance on an entire ML algorithm.
Fence placement for legacy data-race-free programs via synchronization read detection
Authors: McPherson Andrew J. , Nagarajan Vijay , Sarkar Susmit , Cintra Marcelo
Published: December 2015

Fence placement is required to ensure legacy parallel programs operate correctly on relaxed architectures. The challenge is to place as few fences as possible without compromising correctness. By identifying necessary conditions for a read to be an acquire we improve upon the state of the art for legacy DRF programs by up to 2.64x.
SemCache++: semantics-aware caching for efficient multi-GPU offloading
Authors: Al-Saber Nabeel , Kulkarni Milind
Published: December 2015

Offloading computations to multiple GPUs is not an easy task. It requires decomposing data, distributing computations and handling communication manually. Drop-in GPU libraries have made it easy to offload computations to multiple GPUs by hiding this complexity inside library calls. Such encapsulation prevents the reuse of the data between successive kernel invocations resulting in redundant communication. This limitation exists in multi-GPU libraries like CUBLASXT. In this paper, we introduce SemCache++, a semantics-aware GPU cache that automatically manages communication between the CPU and multiple GPUs in addition to optimizing communication by eliminating redundant transfers using caching. SemCache++ is used to build the first multi-GPU drop-in replacement library that (a) uses the virtual memory to automatically manage and optimize multi-GPU communication and (b) requires no program rewriting or annotations. Our caching technique is efficient; it uses a two level caching directory to track matrices and sub-matrices. Experimental results show that our system can eliminate redundant communication and deliver significant performance improvements over multi-GPU libraries like CUBLASXT.
A programming model and runtime system for significance-aware energy-efficient computing
Authors: Vassiliadis Vassilis , Parasyris Konstantinos , Chalios Charalambos , Antonopoulos Christos D. , Lalis Spyros , Bellas Nikolaos , Vandierendonck Hans , Nikolopoulos Dimitrios S.
Published: December 2015

We introduce a task-based programming model and runtime system that exploit the observation that not all parts of a program are equally significant for the accuracy of the end-result, in order to trade off the quality of program outputs for increased energy-efficiency. This is done in a structured and flexible way, allowing for easy exploitation of different points in the quality/energy space, without adversely affecting application performance. The runtime system can apply a number of different policies to decide whether it will execute less-significant tasks accurately or approximately. The experimental evaluation indicates that our system can achieve an energy reduction of up to 83% compared with a fully accurate execution and up to 35% compared with an approximate version employing loop perforation. At the same time, our approach always results in graceful quality degradation.
Section based program analysis to reduce overhead of detecting unsynchronized thread communication
Authors: Das Madan , Southern Gabriel , Renau Jose
Published: December 2015

We propose Section Based Program Analysis (SBPA), a novel way to decompose programs into disjoint sections to identify non-communicating loads and stores during program compilation. We implemented SBPA for a deterministic execution runtime environment and reduced 63% of dynamic memory access instrumentations. We also integrated SBPA with ThreadSanitizer, and achieved a speed-up of 2.74 on a geometric mean basis.
An optimizing compiler for a purely functional web-application language
Authors: Chlipala Adam
Published: December 2015

High-level scripting languages have become tremendously popular for development of dynamic Web applications. Many programmers appreciate the productivity benefits of automatic storage management, freedom from verbose type annotations, and so on. While it is often possible to improve performance substantially by rewriting an application in C or a similar language, very few programmers bother to do so, because of the consequences for human development effort. This paper describes a compiler that makes it possible to have most of the best of both worlds, coding Web applications in a high-level language but compiling to native code with performance comparable to handwritten C code. The source language is Ur/Web, a domain-specific, purely functional, statically typed language for the Web. Through a coordinated suite of relatively straightforward program analyses and algebraic optimizations, we transform Ur/Web programs into almost-idiomatic C code, with no garbage collection, little unnecessary memory allocation for intermediate values, etc. Our compiler is in production use for commercial Web sites supporting thousands of users, and microbenchmarks demonstrate very competitive performance versus mainstream tools.
Program synthesis: opportunities for the next decade
Authors: Bodik Rastislav
Published: December 2015

Program synthesis is the contemporary answer to automatic programming. It innovates in two ways: First, it replaces batch automation with interactivity, assisting the programmer in refining the understanding of the programming problem. Second, it produces programs using search in a candidate space rather than by derivation from a specification. Searching for an acceptable program means that we can accommodate incomplete specifications, such as examples. Additionally, search makes synthesis applicable to domains that lack correct-by-construction derivation rules, such as hardware design, education, end-user programming, and systems biology. The future of synthesis rests on four challenges, each presenting an opportunity to develop novel abstractions for "programming with search." Larger scope: today, we synthesize small, flat programs; synthesis of large software will need constructs for modularity and stepwise refinement. New interaction modes: to solicit the specification without simply asking for more examples, we need to impose a structure on the candidate space and explore it in a dialogue. Construction: how to compile a synthesis problem to a search algorithm without building a compiler? Everything is a program: whatever can be phrased as a program can be in principle synthesized. Indeed, we will see synthesis advance from synthesis of plain programs to synthesis of compilers and languages. The latter may include DSLs, type systems, and modeling languages for biology. As such, synthesis could help mechanize the crown jewel of programming languages research --- the design of abstractions --- which has so far been done manually and only by experts.
Tracing vs. partial evaluation: comparing meta-compilation approaches for self-optimizing interpreters
Authors: Marr Stefan , Ducasse Stéphane
Published: December 2015

Tracing and partial evaluation have been proposed as meta-compilation techniques for interpreters to make just-in-time compilation language-independent. They promise that programs executing on simple interpreters can reach performance of the same order of magnitude as if they would be executed on state-of-the-art virtual machines with highly optimizing just-in-time compilers built for a specific language. Tracing and partial evaluation approach this meta-compilation from two ends of a spectrum, resulting in different sets of tradeoffs. This study investigates both approaches in the context of self-optimizing interpreters, a technique for building fast abstract-syntax-tree interpreters. Based on RPython for tracing and Truffle for partial evaluation, we assess the two approaches by comparing the impact of various optimizations on the performance of an interpreter for SOM, an object-oriented dynamically-typed language. The goal is to determine whether either approach yields clear performance or engineering benefits. We find that tracing and partial evaluation both reach roughly the same level of performance. SOM based on meta-tracing is on average 3x slower than Java, while SOM based on partial evaluation is on average 2.3x slower than Java. With respect to the engineering, tracing has however significant benefits, because it requires language implementers to apply fewer optimizations to reach the same level of performance.
Disjointness domains for fine-grained aliasing
Authors: Brandauer Stephan , Clarke Dave , Wrigstad Tobias
Published: December 2015

Aliasing is crucial for supporting useful implementation patterns, but it makes reasoning about programs difficult. To deal with this problem, numerous type-based aliasing control mechanisms have been proposed, expressing properties such as uniqueness. Uniqueness, however, is black-and-white: either a reference is unique or it can be arbitrarily aliased; and global: excluding aliases throughout the entire system, making code brittle to changing requirements. Disjointness domains, a new approach to alias control, address this problem by enabling more graduations between uniqueness and arbitrary reference sharing. They allow expressing aliasing constraints local to a certain set of variables (either stack variables or fields) for instance that no aliasing occurs between variables within some set of variables but between such sets or the opposite, that aliasing occurs within that set but not between different sets. A hierarchy of disjointness domains controls the flow of references through a program, helping the programmer reason about disjointness and enforce local alias invariants. The resulting system supports fine-grained control of aliasing between both variables and objects, making aliasing explicit to programmers, compilers, and tooling. This paper presents a formal account of disjointness domains along with examples. Disjointness domains provide novel means of expressing may-alias kinds of constraints, which may prove useful in compiler optimisation and verification.