Abstract: The InAlGaN alloy has only recently began receiving
serious attention into its growth and application. High quality InGaN
films have led to the development of light emitting diodes (LEDs) and
blue laser diodes (LDs). The quaternary InAlGaN however, represents
a more versatile material since the bandgap and lattice constant can be
independently varied. We report an ultraviolet (UV) quaternary
InAlGaN multi-quantum wells (MQWs) LD study by using the
simulation program of Integrated System Engineering (ISE TCAD).
Advanced physical models of semiconductor properties were used in
order to obtain an optimized structure. The device performance which
is affected by piezoelectric and thermal effects was studied via
drift-diffusion model for carrier transport, optical gain and loss. The
optical performance of the UV LD with different numbers of quantum
wells was numerically investigated. The main peak of the emission
wavelength for double quantum wells (DQWs) was shifted from 358
to 355.8 nm when the forward current was increased. Preliminary
simulated results indicated that better output performance and lower
threshold current could be obtained when the quantum number is four,
with output power of 130 mW and threshold current of 140 mA.
Abstract: Due to the growth of the urban area towards lands
contaminated with ancient tails, in this work we evaluated if the
leaching with calcium thiosulfate (CaS2O3) for the recovery of silver,
gold and mercury from this soil, also dissolves arsenic, cadmium and
lead; for this, we determined their quantity per each fraction of size
of particle of the soil before and after the dissolution. Half of the soil
samples were leached in the plant Beneficiadora de Jales del Centro,
S. A. de C.V. and the rest of them remained in the laboratory. The
ICP-OES technique was used to determine the amounts of arsenic,
cadmium and lead, in the samples of both lots. The soil samples were
collected in a neighboring area at El Lampotal, Vetagrande,
Zacatecas, México, with an extension of 600 m2 at 22º52' 37.69'' N,
102º25' 11.73'' W. The amount of arsenic, cadmium and lead found
in nonleached soil and for a particle size of 47 μm was 203.72±3.73,
33.63±1.31 and 3480.99±20.4 mg/kg respectively.
Abstract: In the context of spectrum surveillance, a new method
to recover the code of spread spectrum signal is presented, while the
receiver has no knowledge of the transmitter-s spreading sequence. In
our previous paper, we used Genetic algorithm (GA), to recover
spreading code. Although genetic algorithms (GAs) are well known
for their robustness in solving complex optimization problems, but
nonetheless, by increasing the length of the code, we will often lead
to an unacceptable slow convergence speed. To solve this problem we
introduce Particle Swarm Optimization (PSO) into code estimation in
spread spectrum communication system. In searching process for
code estimation, the PSO algorithm has the merits of rapid
convergence to the global optimum, without being trapped in local
suboptimum, and good robustness to noise. In this paper we describe
how to implement PSO as a component of a searching algorithm in
code estimation. Swarm intelligence boasts a number of advantages
due to the use of mobile agents. Some of them are: Scalability, Fault
tolerance, Adaptation, Speed, Modularity, Autonomy, and
Parallelism. These properties make swarm intelligence very attractive
for spread spectrum code estimation. They also make swarm
intelligence suitable for a variety of other kinds of channels. Our
results compare between swarm-based algorithms and Genetic
algorithms, and also show PSO algorithm performance in code
estimation process.
Abstract: In this work, axisymetric CFD simulation of fixed bed
GTL reactor has been conducted, using computational fluid dynamics
(CFD). In fixed bed CFD modeling, when N (tube-to-particle
diameter ratio) has a large value, it is common to consider the packed
bed as a porous media. Synthesis gas (a mixture of predominantly
carbon monoxide and hydrogen) was fed to the reactor. The reactor
length was 20 cm, divided to three sections. The porous zone was in
the middle section of the reactor. The model equations were solved
employing finite volume method. The effects of particle diameter,
bed voidage, fluid velocity and bed length on pressure drop have
been investigated. Simulation results showed these parameters could
have remarkable impacts on the reactor pressure drop.
Abstract: This paper contributes to the debate on the proximate
causes of climate change. Also, it discusses the impact of the global
temperature increases since the beginning of the twentieth century
and the effectiveness of climate change models in isolating the
primary cause (anthropogenic influences or natural variability in
temperature) of the observed temperature increases that occurred
within this period. The paper argues that if climate scientist and
policymakers ignore the anthropogenic influence (greenhouse gases)
on global warming on the pretense of lack of agreement among
various climate models and their inability to account for all the
necessary factors of global warming at all levels the current efforts of
greenhouse emissions control and global warming as a whole could
be exacerbated.
Abstract: The objective of the paper was to understand the use
of an important element of design, namely color in a Semiotic
system. Semiotics is the study of signs and sign processes, it is often
divided into three branches namely (i) Semantics that deals with the
relation between signs and the things to which they refer to mean, (ii)
Syntactics which addresses the relations among signs in formal
structures and (iii) Pragmatics that relates between signs and its
effects on they have on the people who use them to create a plan for
an object or a system referred to as design. Cubism with its versatility
was the key design tool prevalent across the 20th century. In order to
analyze the user's understanding of interaction and appreciation of
color through the movement of Cubism, an exercise was undertaken
in Dept. of Design, IIT Guwahati. This included tasks to design a
composition using color and sign process to the theme 'Between the
Lines' on a given tessellation where the users relate their work to the
world they live in, which in this case was the college campus of IIT
Guwahati. The findings demonstrate impact of the key design
element color on the principles of visual perception based on image
analysis of specific compositions.
Abstract: Linear two-point boundary value problem of order two is solved using extended cubic B-spline interpolation method. There is one free parameters, λ, that control the tension of the solution curve. For some λ, this method produced better results than cubic B-spline interpolation method.
Abstract: The pollutant removal efficiency of the Intermittently
Decanted Extended Aeration (IDEA) wastewater treatment system at
Curtin University Sarawak Campus, and conventional activated
sludge wastewater treatment system at a local resort, Resort A, is
monitored. The influent and effluent characteristics are tested during
wet and dry weather conditions, and peak and off peak periods. For
the wastewater treatment systems at Curtin Sarawak and Resort A,
during dry weather and peak season, it was found that the BOD5
concentration in the influent is 121.7mg/L and 80.0mg/L
respectively, and in the effluent, 18.7mg/L and and 18.0mg/L
respectively. Analysis of the performance of the IDEA treatment
system showed that the operational costs can be minimized by 3%, by
decreasing the number of operating cycles. As for the treatment
system in Resort A, by utilizing a smaller capacity air blower, a
saving of 12% could be made in the operational costs.
Abstract: Environmental studies have expanded dramatically all
over the world in the past few years. Nowadays businesses interact
with society and the environment in ways that put their mark on both
sides. Efforts improving human standard living, through the control
of nature and the development of new products, have also resulted in
contamination of the environment. Consequently companies play an
important role in environmental sustainability of a region or country.
Therefore we can say that a company's sustainable development is
strictly dependent on the environment. This article presents a fuzzy
model to evaluate a company's environmental impact. Article
illustrates an example of the automotive industry in order to prove the
usefulness of using such a model.
Abstract: The Partitioned Global Address Space (PGAS) programming
paradigm offers ease-of-use in expressing parallelism
through a global shared address space while emphasizing performance
by providing locality awareness through the partitioning of
this address space. Therefore, the interest in PGAS programming
languages is growing and many new languages have emerged and
are becoming ubiquitously available on nearly all modern parallel
architectures. Recently, new parallel machines with multiple cores
are designed for targeting high performance applications. Most of the
efforts have gone into benchmarking but there are a few examples of
real high performance applications running on multicore machines.
In this paper, we present and evaluate a parallelization technique
for implementing a local DNA sequence alignment algorithm using
a PGAS based language, UPC (Unified Parallel C) on a chip
multithreading architecture, the UltraSPARC T1.
Abstract: The purpose of this paper is to explore the role of
cognitive decision effort in recommendation system, combined with
indicators "information quality" and "service quality" from IS success
model to exam the awareness of the user for the "recommended system
performance". A total of 411 internet user answered a questionnaire
assessing their attention of use and satisfaction of recommendation
system in internet book store. Quantitative result indicates following
research results. First, information quality of recommended system
has obvious influence in consumer shopping decision-making process,
and the attitude to use the system. Second, in the process of consumer's
shopping decision-making, the recommendation system has no
significant influence for consumers to pay lower cognitive
decision-making effort. Third, e-commerce platform provides
recommendations and information is necessary, but the quality of
information on user needs must be considered, or they will be other
competitors offer homogeneous services replaced.
Abstract: This survey highlights a number of important issues
which relate to the needs to counseling for distance learners studying
at the School of Distance Education in University science Malaysia
(DEUSM) according to their gender. Data were obtained by selfreport
questionnaire that had been developed by the researchers in
counseling and educational psychology and interviews were take
place. 116 voluntary respondents complete the Questionnaire and
returned it back during new student-s registration week.64% of the
respondents were female and 52% were males that means
55%ofthem were females and 45% were males. The data was
analyzed to find out the frequencies of respondents agreements of the
items. The average of the female was 18 and the average of the male
was 19.6 by using t- test there is no significant values between the
genders. The findings show that respondents have needs for
counseling. (22) Significant needs for mails (DEUSM) the highest
was their families complain about the amount of time they spend at
work. (11) Significant needs for females the highest was they
convinced themselves that they only need 4 to 5 hours of sleep per
night.
Abstract: This paper presents an architecture to assist in the
development of tools to perform experimental analysis. Existing
implementations of tools based on this architecture are also described
in this paper. These tools are applied to the real world problem of
fault attack emulation and detection in cryptographic algorithms.
Abstract: Ti-6Al-4V alloy has demonstrated a high strength to
weight ratio as well as good properties at high temperature. The
successful application of the alloy in some important areas depends
on suitable joining techniques. Friction welding has many
advantageous features to be chosen for joining Titanium alloys. The
present work investigates the feasibility of producing similar metal
joints of this Titanium alloy by rotary friction welding method. The
joints are produced at three different speeds and the performances of
the welded joints are evaluated by conducting microstructure studies,
Vickers Hardness and tensile tests at the joints. It is found that the
weld joints produced are sound and the ductile fractures in the tensile
weld specimens occur at locations away from the welded joints. It is
also found that a rotational speed of 1500 RPM can produce a very
good weld, with other parameters kept constant.
Abstract: For a variety of safety and economic reasons, engineering undergraduates in Australia have experienced diminishing access to the real hardware that is typically the embodiment of their theoretical studies. This trend will delay the development of practical competence, decrease the ability to model and design, and suppress motivation. The author has attempted to address this concern by creating a software tool that contains both photographic images of real machinery, and sets of graphical modeling 'tools'. Academics from a range of disciplines can use the software to set tutorial tasks, and incorporate feedback comments for a range of student responses. An evaluation of the software demonstrated that students who had solved modeling problems with the aid of the electronic tutor performed significantly better in formal examinations with similar problems. The 2-D graphical diagnostic routines in the Tutor have the potential to be used in a wider range of problem-solving tasks.
Abstract: Artificial Neural Networks (ANNs) have been used successfully in many scientific, industrial and business domains as a method for extracting knowledge from vast amounts of data. However the use of ANN techniques in the sporting domain has been limited. In professional sport, data is stored on many aspects of teams, games, training and players. Sporting organisations have begun to realise that there is a wealth of untapped knowledge contained in the data and there is great interest in techniques to utilise this data. This study will use player data from the elite Australian Football League (AFL) competition to train and test ANNs with the aim to predict the onset of injuries. The results demonstrate that an accuracy of 82.9% was achieved by the ANNs’ predictions across all examples with 94.5% of all injuries correctly predicted. These initial findings suggest that ANNs may have the potential to assist sporting clubs in the prediction of injuries.
Abstract: The wrinkling of a thin elastic bi-annular plate with piecewise-constant mechanical properties, subjected to radial stretching, is considered. The critical wrinkling stretching loading and the corresponding wrinkling patterns are extensively investigated, together with the roles played by both the geometrical and mechanical parameters.
Abstract: This paper presents an integrated case based and rule
based reasoning method for car faulty diagnosis. The reasoning
method is done through extracting the past cases from the Proton
Service Center while comparing with the preset rules to deduce a
diagnosis/solution to a car service case. New cases will be stored to
the knowledge base. The test cases examples illustrate the
effectiveness of the proposed integrated reasoning. It has proven
accuracy of similar reasoning if carried out by a service advisor from
the service center.
Abstract: This paper presents the new results of energy plant –
rye and triticale at yellow ripeness and ripe, pre-treatment in high
pressure steam reactor and monosaccharide extraction. There were
investigated the influence of steam pressure (20 to 22 bar), retention
duration (180 to 240 s) and catalytic sulphuric acid concentration
strength (0 to 0.5 %) on the pre-treatment process, contents of
monosaccharides (glucose, arabinose, xylose, mannose) and
undesirable by-compounds (furfural and HMF) in the reactor. The
study has determined that the largest amount of monosaccharides
(37.2 % of glucose, 2.7 % of arabinose, 8.4 % of xylose, and 1.3 %
of mannose) was received in the rye at ripe, the samples of which
were mixed with 0.5 % concentration of catalytic sulphuric acid, and
hydrolysed in the reactor, where the pressure was 20 bar, whereas the
reaction time – 240 s.
Abstract: Competing risks survival data that comprises of more
than one type of event has been used in many applications, and one
of these is in clinical study (e.g. in breast cancer study). The
decision tree method can be extended to competing risks survival
data by modifying the split function so as to accommodate two or
more risks which might be dependent on each other. Recently,
researchers have constructed some decision trees for recurrent
survival time data using frailty and marginal modelling. We further
extended the method for the case of competing risks. In this paper,
we developed the decision tree method for competing risks survival
time data based on proportional hazards for subdistribution of
competing risks. In particular, we grow a tree by using deviance
statistic. The application of breast cancer data is presented. Finally,
to investigate the performance of the proposed method, simulation
studies on identification of true group of observations were executed.