Abstract: Alumina matrix composites with addition of hexagonal boron nitride (hBN), acting as solid lubricant, were produced. Main purpose of solid lubricants is to dispose the necessity of using cooling lubricants in machining process. Hot pressing was used as a consolidating process for Al2O3-x%wt.hBN (x=1/ 2,5/ 5 /7,5 /10) composites. Properties of sinters such as relative density, hardness, Young-s modulus and fracture toughness were examined. Obtained samples characterize by high relative density. Hardness and fracture toughness values allow the use of alumina – hBN composites for machining steels even in hardened condition. However it was observed that high weight content of hBN can negatively influence the mechanical properties of composites.
Abstract: In this paper we report a study aimed at determining
the most effective animation technique for representing ASL
(American Sign Language) finger-spelling. Specifically, in the study
we compare two commonly used 3D computer animation methods
(keyframe animation and motion capture) in order to ascertain which
technique produces the most 'accurate', 'readable', and 'close to
actual signing' (i.e. realistic) rendering of ASL finger-spelling. To
accomplish this goal we have developed 20 animated clips of fingerspelled
words and we have designed an experiment consisting of a
web survey with rating questions. 71 subjects ages 19-45 participated
in the study. Results showed that recognition of the words was
correlated with the method used to animate the signs. In particular,
keyframe technique produced the most accurate representation of the
signs (i.e., participants were more likely to identify the words
correctly in keyframed sequences rather than in motion captured
ones). Further, findings showed that the animation method had an
effect on the reported scores for readability and closeness to actual
signing; the estimated marginal mean readability and closeness was
greater for keyframed signs than for motion captured signs. To our
knowledge, this is the first study aimed at measuring and comparing
accuracy, readability and realism of ASL animations produced with
different techniques.
Abstract: Methods of clustering which were developed in the
data mining theory can be successfully applied to the investigation of
different kinds of dependencies between the conditions of
environment and human activities. It is known, that environmental
parameters such as temperature, relative humidity, atmospheric
pressure and illumination have significant effects on the human
mental performance. To investigate these parameters effect, data
mining technique of clustering using entropy and Information Gain
Ratio (IGR) K(Y/X) = (H(X)–H(Y/X))/H(Y) is used, where
H(Y)=-ΣPi ln(Pi). This technique allows adjusting the boundaries of
clusters. It is shown that the information gain ratio (IGR) grows
monotonically and simultaneously with degree of connectivity
between two variables. This approach has some preferences if
compared, for example, with correlation analysis due to relatively
smaller sensitivity to shape of functional dependencies. Variant of an
algorithm to implement the proposed method with some analysis of
above problem of environmental effects is also presented. It was
shown that proposed method converges with finite number of steps.
Abstract: The Requirements Abstraction Model (RAM) helps in managing abstraction in requirements by organizing them at four levels (product, feature, function and component). The RAM is adaptable and can be tailored to meet the needs of the various organizations. Because software requirements are an important source of information for developing high-level tests, organizations willing to adopt the RAM model need to know the suitability of the RAM requirements for developing high-level tests. To investigate this suitability, test cases from twenty randomly selected requirements were developed, analyzed and graded. Requirements were selected from the requirements document of a Course Management System, a web based software system that supports teachers and students in performing course related tasks. This paper describes the results of the requirements document analysis. The results show that requirements at lower levels in the RAM are suitable for developing executable tests whereas it is hard to develop from requirements at higher levels.
Abstract: A highly optimized implementation of binary mixture
diffusion with no initial bulk velocity on graphics processors is
presented. The lattice Boltzmann model is employed for simulating
the binary diffusion of oxygen and nitrogen into each other with
different initial concentration distributions. Simulations have been
performed using the latest proposed lattice Boltzmann model that
satisfies both the indifferentiability principle and the H-theorem for
multi-component gas mixtures. Contemporary numerical
optimization techniques such as memory alignment and increasing
the multiprocessor occupancy are exploited along with some novel
optimization strategies to enhance the computational performance on
graphics processors using the C for CUDA programming language.
Speedup of more than two orders of magnitude over single-core
processors is achieved on a variety of Graphical Processing Unit
(GPU) devices ranging from conventional graphics cards to
advanced, high-end GPUs, while the numerical results are in
excellent agreement with the available analytical and numerical data
in the literature.
Abstract: In this paper, an erosion-based model for abrasive
waterjet (AWJ) turning process is presented. By using modified
Hashish erosion model, the volume of material removed by impacting
of abrasive particles to surface of the rotating cylindrical specimen is
estimated and radius reduction at each rotation is calculated.
Different to previous works, the proposed model considers the
continuous change in local impact angle due to change in workpiece
diameter, axial traverse rate of the jet, the abrasive particle roundness
and density. The accuracy of the proposed model is examined by
experimental tests under various traverse rates. The final diameters
estimated by the proposed model are in good accordance with
experiments.
Abstract: The American Health Level Seven (HL7) Reference Information Model (RIM) consists of six back-bone classes that have different specialized attributes. Furthermore, for the purpose of enforcing the semantic expression, there are some specific mandatory vocabulary domains have been defined for representing the content values of some attributes. In the light of the fact that it is a duplicated effort on spending a lot of time and human cost to develop and modify Clinical Information Systems (CIS) for most hospitals due to the variety of workflows. This study attempts to design and develop sharing RIM-based components of the CIS for the different business processes. Therefore, the CIS contains data of a consistent format and type. The programmers can do transactions with the RIM-based clinical repository by the sharing RIM-based components. And when developing functions of the CIS, the sharing components also can be adopted in the system. These components not only satisfy physicians- needs in using a CIS but also reduce the time of developing new components of a system. All in all, this study provides a new viewpoint that integrating the data and functions with the business processes, it is an easy and flexible approach to build a new CIS.
Abstract: This research studied about green logistics and the
expected benefit that organization gotten when adapted to green
logistics also the organization concerned about the important activity
in green logistics to apply in implementation from study was found
that the benefit of green logistics that organization was gotten by
logistics management which was the increased efficiency process of
management the product from producer to customer all of reduce
production cost, increased value added save energy and prevented
environment together
From study was found that the organization had green logistics to
apply in logistics activities in supply chain since downstream till
upstream to prevent environment as follow 1). Purchasing process,
trade facilitation enhance such as linking of information technology
during business to business (B2B business). 2). Productions process
improved by business logistics improvement 3). Warehouse
management process such as recycled packaging, moving goods in to
warehouse, transportation goods and inside receiving and delivery
products plan.
Abstract: Technological innovation capability (TIC) is
defined as a comprehensive set of characteristics of a firm that
facilities and supports its technological innovation strategies.
An audit to evaluate the TICs of a firm may trigger
improvement in its future practices. Such an audit can be used
by the firm for self assessment or third-party independent
assessment to identify problems of its capability status. This
paper attempts to develop such an auditing framework that
can help to determine the subtle links between innovation
capabilities and business performance; and to enable the
auditor to determine whether good practice is in place. The
seven TICs in this study include learning, R&D, resources
allocation, manufacturing, marketing, organization and
strategic planning capabilities. Empirical data was acquired
through a survey study of 200 manufacturing firms in the
Hong Kong/Pearl River Delta (HK/PRD) region. Structural
equation modelling was employed to examine the
relationships among TICs and various performance indicators:
sales performance, innovation performance, product
performance, and sales growth. The results revealed that
different TICs have different impacts on different
performance measures. Organization capability was found to
have the most influential impact. Hong Kong manufacturers
are now facing the challenge of high-mix-low-volume
customer orders. In order to cope with this change, good
capability in organizing different activities among various
departments is critical to the success of a company.
Abstract: Combustion, emission and performance
characterization of a single cylinder diesel engine using methanol
diesel blends was carried out. The blends were 5% (v/v) methanol in
diesel (MD05) and 10% (v/v) methanol in diesel (MD10). The
problem of solubility of methanol and diesel was addressed by an
agitator placed inside the fuel tank to prevent phase separation. The
results indicated that total combustion duration was reduced by15.8%
for MD05 and 31.27% for MD10compared to the baseline data.
Ignition delay was increased with increasing methanol volume
fraction in the test fuel. Total cyclic heat release was reduced by
1.5% for MD05 and 6.7% for MD10 as compared to diesel baseline.
Emissions of carbon monoxide, hydrocarbons along with smoke were
reduced and that of nitrogen oxides were increased with rising
methanol contents in the test fuel. Full load brake thermal efficiency
was marginally reduced with increased methanol composition in the
blend.
Abstract: Municipal solid waste (MSW) comprises of a wide
range of heterogeneous materials generated by individual, household
or organization and may include food waste, garden wastes, papers,
textiles, rubbers, plastics, glass, ceramics, metals, wood wastes,
construction wastes but it is not limited to the above mentioned
fractions. The most common Municipal Solid Waste pretreatment
method in use is thermal pretreatment (incineration) and Mechanical
Biological pretreatment. This paper presents an overview of these
two pretreatment methods describing their benefits and laboratory
scale reactors that simulate landfill conditions were constructed in
order to compare emissions in terms of biogas production and
leachate contamination between untreated Municipal Solid Waste and
Mechanical Biological Pretreated waste. The findings of this study
showed that Mechanical Biological pretreatment of waste reduces the
emission level of waste and the benefit over the landfilling of
untreated waste is significant.
Abstract: The paper presents new results of a recent industry
supported research and development study in which an efficient
framework for evaluating practical and meaningful power system
reliability and quality indices was applied. The system-wide
integrated performance indices are capable of addressing and
revealing areas of deficiencies and bottlenecks as well as
redundancies in the composite generation-transmission-demand
structure of large-scale power grids. The technique utilizes a linear
programming formulation, which simulates practical operating
actions and offers a general and comprehensive framework to assess
the harmony and compatibility of generation, transmission and
demand in a power system. Practical applications to a reduced
system model as well as a portion of the Saudi power grid are also
presented in the paper for demonstration purposes.
Abstract: The current of professional bicycle pedal-s
manufacturing model mostly used casting, forging, die-casting
processing methods, so the paper used 7075 aluminum alloy which is
to produce the bicycle parts most commonly, and employs the
rigid-plastic finite element (FE) DEFORMTM 3D software to simulate
and to analyze the professional bicycle pedal design. First we use Solid
works 2010 3D graphics software to design the professional bicycle
pedal of the mold and appearance, then import finite element (FE)
DEFORMTM 3D software for analysis. The paper used rigid-plastic
model analytical methods, and assuming mode to be rigid body. A
series of simulation analyses in which the variables depend on
different temperature of forging billet, friction factors, forging speed,
mold temperature are reveal to effective stress, effective strain, damage
and die radial load distribution for forging bicycle pedal. The analysis
results hope to provide professional bicycle pedal forming mold
references to identified whether suit with the finite element results for
high-strength design suitability of aluminum alloy.
Abstract: This paper presents a new method which applies an
artificial bee colony algorithm (ABC) for capacitor placement in
distribution systems with an objective of improving the voltage profile
and reduction of power loss. The ABC algorithm is a new population
based meta heuristic approach inspired by intelligent foraging behavior
of honeybee swarm. The advantage of ABC algorithm is that
it does not require external parameters such as cross over rate and
mutation rate as in case of genetic algorithm and differential evolution
and it is hard to determine these parameters in prior. The other
advantage is that the global search ability in the algorithm is implemented
by introducing neighborhood source production mechanism
which is a similar to mutation process. To demonstrate the validity
of the proposed algorithm, computer simulations are carried out on
69-bus system and compared the results with the other approach
available in the literature. The proposed method has outperformed the
other methods in terms of the quality of solution and computational
efficiency.
Abstract: Experiments have been carried out at the Latvia
University of Agriculture Department of Food Technology. The aim
of this work was to assess the effect of sous vide packaging during
the storage time of salad with meat in mayonnaise at different storage
temperature. Samples were evaluated at 0, 1, 3, 7, 10, 15, 18, 25, 29,
42, and 52 storage days at the storage temperature of +4±0.5 ºC and
+10±0.5 ºC. Experimentally the quality of the salad with meat in
mayonnaise was characterized by measuring colour, pH and
microbiological properties. The sous vide packaging was effective in
protecting the product from physical, chemical, and microbial quality
degradation. The sous vide packaging significantly reduces microbial
growth at storage temperature of +4±0.5 ºC and +10±0.5 ºC.
Moreover, it is possible to extend the product shelf life to 52 days
even when stored at +10±0.5 ºC.
Abstract: The present study was provided to examine the
vortical structures generated by two inclined impinging jets with
experimental and numerical investigations. The jets are issuing with a
pitch angle α=40° into a confined quiescent fluid. The experimental
investigation on flow patterns was visualized by using olive particles
injected into the jets illuminated by Nd:Yag laser light to reveal the
finer details of the confined jets interaction. It was observed that two
counter-rotating vortex pairs (CVPs) were generated in the near
region. A numerical investigation was also performed. First, the
numerical results were validates against the experimental results and
then the numerical model was used to study the effect of section ratio
on the evolution of the CVPs. Our results show promising agreement
with experimental data, and indicate that our model has the potential
to produce useful and accurate data regarding the evolution of CVPs.
Abstract: Direct numerical simulation (DNS) is used to study the evolution of a boundary layer that was laminar initially followed by separation and then reattachment owing to generation of turbulence. This creates a closed region of recirculation, known as the laminar-separation bubble. The present simulation emulates the flow environment encountered in a modern LP turbine blade, where a laminar separation bubble may occur on the suction surface. The unsteady, incompressible three-dimensional (3-D) Navier-Stokes (NS) equations have been solved over a flat plate in the Cartesian coordinates. The adverse pressure gradient, which causes the flow to separate, is created by a boundary condition. The separated shear layer undergoes transition through appearance of ╬ø vortices, stretching of these create longitudinal streaks. Breakdown of the streaks into small and irregular structures makes the flow turbulent downstream.
Abstract: In this paper, we proposed a novel receiver algorithm
for coherent underwater acoustic communications. The proposed
receiver is composed of three parts: (1) Doppler tracking and
correction, (2) Time reversal channel estimation and combining, and
(3) Joint iterative equalization and decoding (JIED). To reduce
computational complexity and optimize the equalization algorithm,
Time reversal (TR) channel estimation and combining is adopted to
simplify multi-channel adaptive decision feedback equalizer (ADFE)
into single channel ADFE without reducing the system performance.
Simultaneously, the turbo theory is adopted to form joint iterative
ADFE and convolutional decoder (JIED). In JIED scheme, the ADFE
and decoder exchange soft information in an iterative manner, which
can enhance the equalizer performance using decoding gain. The
simulation results show that the proposed algorithm can reduce
computational complexity and improve the performance of equalizer.
Therefore, the performance of coherent underwater acoustic
communications can be improved greatly.
Abstract: The lack of any centralized infrastructure in mobile ad
hoc networks (MANET) is one of the greatest security concerns in
the deployment of wireless networks. Thus communication in
MANET functions properly only if the participating nodes cooperate
in routing without any malicious intention. However, some of the
nodes may be malicious in their behavior, by indulging in flooding
attacks on their neighbors. Some others may act malicious by
launching active security attacks like denial of service. This paper
addresses few related works done on trust evaluation and
establishment in ad hoc networks. Related works on flooding attack
prevention are reviewed. A new trust approach based on the extent of
friendship between the nodes is proposed which makes the nodes to
co-operate and prevent flooding attacks in an ad hoc environment.
The performance of the trust algorithm is tested in an ad hoc network
implementing the Ad hoc On-demand Distance Vector (AODV)
protocol.
Abstract: In this paper, multi-processors job shop scheduling problems are solved by a heuristic algorithm based on the hybrid of priority dispatching rules according to an ant colony optimization algorithm. The objective function is to minimize the makespan, i.e. total completion time, in which a simultanous presence of various kinds of ferons is allowed. By using the suitable hybrid of priority dispatching rules, the process of finding the best solution will be improved. Ant colony optimization algorithm, not only promote the ability of this proposed algorithm, but also decreases the total working time because of decreasing in setup times and modifying the working production line. Thus, the similar work has the same production lines. Other advantage of this algorithm is that the similar machines (not the same) can be considered. So, these machines are able to process a job with different processing and setup times. According to this capability and from this algorithm evaluation point of view, a number of test problems are solved and the associated results are analyzed. The results show a significant decrease in throughput time. It also shows that, this algorithm is able to recognize the bottleneck machine and to schedule jobs in an efficient way.