Abstract: Delamination between layers in composite materials is a major structural failure. The delamination resistance is quantified by the critical strain energy release rate (SERR). The present investigation deals with the strain energy release rate of two woven fabric composites. Materials used are made of two types of glass fiber (360 gsm and 600 gsm) of plain weave and epoxy as matrix. The fracture behavior is studied using the mode I, double cantilever beam test and the mode II, end notched flexure test, in order to determine the energy required for the initiation and growth of an artificial crack. The delamination energy of these two materials is compared in order to study the effect of weave and reinforcement on mechanical properties. The fracture mechanism is also analyzed by means of scanning electron microscopy (SEM). It is observed that the plain weave fabric composite with lesser strand width has higher inter laminar fracture properties compared to the plain weave fabric composite with more strand width.
Abstract: In the LFC problem, the interconnections among some areas are the input of disturbances, and therefore, it is important to suppress the disturbances by the coordination of governor systems. In contrast, tie-line power flow control by TCPS located between two areas makes it possible to stabilize the system frequency oscillations positively through interconnection, which is also expected to provide a new ancillary service for the further power systems. Thus, a control strategy using controlling the phase angle of TCPS is proposed for provide active control facility of system frequency in this paper. Also, the optimum adjustment of PID controller's parameters in a robust way under bilateral contracted scenario following the large step load demands and disturbances with and without TCPS are investigated by Particle Swarm Optimization (PSO), that has a strong ability to find the most optimistic results. This newly developed control strategy combines the advantage of PSO and TCPS and has simple stricture that is easy to implement and tune. To demonstrate the effectiveness of the proposed control strategy a three-area restructured power system is considered as a test system under different operating conditions and system nonlinearities. Analysis reveals that the TCPS is quite capable of suppressing the frequency and tie-line power oscillations effectively as compared to that obtained without TCPS for a wide range of plant parameter changes, area load demands and disturbances even in the presence of system nonlinearities.
Abstract: The effects of dynamic subgrid scale (SGS) models are
investigated in variational multiscale (VMS) LES simulations of bluff
body flows. The spatial discretization is based on a mixed finite
element/finite volume formulation on unstructured grids. In the VMS
approach used in this work, the separation between the largest and the
smallest resolved scales is obtained through a variational projection
operator and a finite volume cell agglomeration. The dynamic version
of Smagorinsky and WALE SGS models are used to account for
the effects of the unresolved scales. In the VMS approach, these
effects are only modeled in the smallest resolved scales. The dynamic
VMS-LES approach is applied to the simulation of the flow around a
circular cylinder at Reynolds numbers 3900 and 20000 and to the flow
around a square cylinder at Reynolds numbers 22000 and 175000. It
is observed as in previous studies that the dynamic SGS procedure
has a smaller impact on the results within the VMS approach than in
LES. But improvements are demonstrated for important feature like
recirculating part of the flow. The global prediction is improved for
a small computational extra cost.
Abstract: This paper makes an attempt to solve the problem of
searching and retrieving of similar MRI photos via Internet services
using morphological features which are sourced via the original
image. This study is aiming to be considered as an additional tool of
searching and retrieve methods. Until now the main way of the
searching mechanism is based on the syntactic way using keywords.
The technique it proposes aims to serve the new requirements of
libraries. One of these is the development of computational tools for
the control and preservation of the intellectual property of digital
objects, and especially of digital images. For this purpose, this paper
proposes the use of a serial number extracted by using a previously
tested semantic properties method. This method, with its center being
the multi-layers of a set of arithmetic points, assures the following
two properties: the uniqueness of the final extracted number and the
semantic dependence of this number on the image used as the
method-s input. The major advantage of this method is that it can
control the authentication of a published image or its partial
modification to a reliable degree. Also, it acquires the better of the
known Hash functions that the digital signature schemes use and
produces alphanumeric strings for cases of authentication checking,
and the degree of similarity between an unknown image and an
original image.
Abstract: Speckle noise affects all coherent imaging systems
including medical ultrasound. In medical images, noise suppression
is a particularly delicate and difficult task. A tradeoff between noise
reduction and the preservation of actual image features has to be made
in a way that enhances the diagnostically relevant image content.
Even though wavelets have been extensively used for denoising
speckle images, we have found that denoising using contourlets gives
much better performance in terms of SNR, PSNR, MSE, variance and
correlation coefficient. The objective of the paper is to determine the
number of levels of Laplacian pyramidal decomposition, the number
of directional decompositions to perform on each pyramidal level and
thresholding schemes which yields optimal despeckling of medical
ultrasound images, in particular. The proposed method consists of the
log transformed original ultrasound image being subjected to contourlet
transform, to obtain contourlet coefficients. The transformed
image is denoised by applying thresholding techniques on individual
band pass sub bands using a Bayes shrinkage rule. We quantify the
achieved performance improvement.
Abstract: This paper presents a novel approach for optimal
reconfiguration of radial distribution systems. Optimal
reconfiguration involves the selection of the best set of branches to
be opened, one each from each loop, such that the resulting radial
distribution system gets the desired performance. In this paper an
algorithm is proposed based on simple heuristic rules and identified
an effective switch status configuration of distribution system for the
minimum loss reduction. This proposed algorithm consists of two
parts; one is to determine the best switching combinations in all loops
with minimum computational effort and the other is simple optimum
power loss calculation of the best switching combination found in
part one by load flows. To demonstrate the validity of the proposed
algorithm, computer simulations are carried out on 33-bus system.
The results show that the performance of the proposed method is
better than that of the other methods.
Abstract: This research study the application of the immobilized
TiO2 layer and Cu-TiO2 layer on graphite substrate as a negative
electrode or anode for Li-ion battery. The titania layer was produced
through chemical bath deposition method, meanwhile Cu particles
were deposited electrochemically. A material can be used as an
electrode as it has capability to intercalates Li ions into its crystal
structure. The Li intercalation into TiO2/Graphite and Cu-
TiO2/Graphite were analyzed from the changes of its XRD pattern
after it was used as electrode during discharging process. The XRD
patterns were refined by Le Bail method in order to determine the
crystal structure of the prepared materials. A specific capacity and the
cycle ability measurement were carried out to study the performance
of the prepared materials as negative electrode of the Li-ion battery.
The specific capacity was measured during discharging process from
fully charged until the cut off voltage. A 300 was used as a load.
The result shows that the specific capacity of Li-ion battery with
TiO2/Graphite as negative electrode is 230.87 ± 1.70mAh.g-1 which is
higher than the specific capacity of Li-ion battery with pure graphite
as negative electrode, i.e 140.75 ±0.46mAh.g-1. Meanwhile
deposition of Cu onto TiO2 layer does not increase the specific
capacity, and the value even lower than the battery with
TiO2/Graphite as electrode. The cycle ability of the prepared battery
is only two cycles, due to the Li ribbon which was used as cathode
became fragile and easily broken.
Abstract: Multimedia distributed systems deal with heterogeneous
data, such as texts, images, graphics, video and audio. The specification
of temporal relations among different data types and distributed
sources is an open research area. This paper proposes a fully
distributed synchronization model to be used in multimedia systems.
One original aspect of the model is that it avoids the use of a common
reference (e.g. wall clock and shared memory). To achieve this, all
possible multimedia temporal relations are specified according to
their causal dependencies.
Abstract: Mercury is a natural occurring element and present in
various concentrations in the environment. Due to its toxic effects, it
is desirable to research mercury sensitive materials to adsorb
mercury. This paper describes the preparation of Au nanoparticles for
mercury adsorption by using a microwave (MW)-polyol method in
the presence of three different Sodium Chloride (NaCl)
concentrations (10, 20 and 30 mM). Mixtures of spherical, triangular,
octahedral, decahedral particles and 1-D product were obtained using
this rapid method. Sizes and shapes was found strongly depend on the
concentrations of NaCl. Without NaCl concentration, spherical,
triangular plates, octahedral, decahedral nanoparticles and 1D
product were produced. At the lower NaCl concentration (10 mM),
spherical, octahedral and decahedral nanoparticles were present,
while spherical and decahedral nanoparticles were preferentially form
by using 20 mM of NaCl concentration. Spherical, triangular plates,
octahedral and decahedral nanoparticles were obtained at the highest
NaCl concentration (30 mM). The amount of mercury adsorbed using
20 ppm mercury solution is the highest (67.5 %) for NaCl
concentration of 30 mM. The high yield of polygonal particles will
increase the mercury adsorption. In addition, the adsorption of
mercury is also due to the sizes of the particles. The sizes of particles
become smaller with increasing NaCl concentrations (size ranges, 5-
16 nm) than those synthesized without addition of NaCl (size ranges
11-32 nm). It is concluded that NaCl concentrations affects the
formation of sizes and shapes of Au nanoparticles thus affects the
mercury adsorption.
Abstract: In recent years a number of applications with multirobot
systems (MRS) is growing in various areas. But their design
is in practice often difficult and algorithms are proposed for the
theoretical background and do not consider errors and noise in real
conditions, so they are not usable in real environment. These errors
are visible also in task of target localization enough, when robots
try to find and estimate the position of the target by the sensors.
Localization of target is possible also with one robot but as it was
examined target finding and localization with group of mobile robots
can estimate the target position more accurately and faster. The
accuracy of target position estimation is made by cooperation of
MRS and particle filtering. Advantage of usage the MRS with particle
filtering was tested on task of fixed target localization by group of
mobile robots.
Abstract: Passive systems were born with the purpose of the
greatest exploitation of solar energy in cold climates and high
altitudes. They spread themselves until the 80-s all over the world
without any attention to the specific climate and the summer
behavior; this caused the deactivation of the systems due to a series
of problems connected to the summer overheating, the complex
management and the rising of the dust.
Until today the European regulation limits only the winter
consumptions without any attention to the summer behavior but, the
recent European EN 15251 underlines the relevance of the indoor
comfort, and the necessity of the analytic studies validation by
monitoring case studies.
In the porpose paper we demonstrate that the solar wall is an
efficient system both from thermal comfort and energy saving point
of view and it is the most suitable for our temperate climates because
it can be used as a passive cooling sistem too. In particular the paper
present an experimental and numerical analisys carried out on a case
study with nine different solar passive systems in Ancona, Italy.
We carried out a detailed study of the lodging provided by the
solar wall by the monitoring and the evaluation of the indoor
conditions.
Analyzing the monitored data, on the base of recognized models
of comfort (ISO, ASHRAE, Givoni-s BBCC), is emerged that the
solar wall has an optimal behavior in the middle seasons. In winter
phase this passive system gives more advantages in terms of energy
consumptions than the other systems, because it gives greater heat
gain and therefore smaller consumptions. In summer, when outside
air temperature return in the mean seasonal value, the indoor comfort
is optimal thanks to an efficient transversal ventilation activated from
the same wall.
Abstract: School homework has been synonymous with students- life in Chinese national type primary schools in Malaysia. Although many reports in the press claimed that students were burdened with too much of it, homework continues to be a common practice in national type schools that is believed to contribute to academic achievement. This study is conducted to identify the relationship between the burden of school homework and academic achievement among pupils in Chinese National Type Primary School in the state of Perak, Malaysia. A total of 284 students (142 from urban and 142 from rural) respectively were chosen as participants in this study. Variables of gender and location (urban/rural areas) has shown significant difference in student academic achievement. Female Chinese student from rural areas showed a higher mean score than males from urban area. Therefore, the Chinese language teachers should give appropriate and relevant homework to primary school students to achieve good academic performance.
Abstract: As the data-driven economy is growing faster than
ever and the demand for energy is being spurred, we are facing
unprecedented challenges of improving energy efficiency in data
centers. Effectively maximizing energy efficiency or minimising the
cooling energy demand is becoming pervasive for data centers. This
paper investigates overall energy consumption and the energy
efficiency of cooling system for a data center in Finland as a case
study. The power, cooling and energy consumption characteristics
and operation condition of facilities are examined and analysed.
Potential energy and cooling saving opportunities are identified and
further suggestions for improving the performance of cooling system
are put forward. Results are presented as a comprehensive evaluation
of both the energy performance and good practices of energy
efficient cooling operations for the data center. Utilization of an
energy recovery concept for cooling system is proposed. The
conclusion we can draw is that even though the analysed data center
demonstrated relatively high energy efficiency, based on its power
usage effectiveness value, there is still a significant potential for
energy saving from its cooling systems.
Abstract: Earthquakes produce some of the most violent loading
situations that a structure can be subjected to and if a structure fails
under these loads then inevitably human life is put at risk. One of the
most common methods by which a structure fails under seismic
loading is at the connection of structural elements. The research
presented in this paper investigates the interlock systems as a novel
method for building structures. The main objective of this
experimental study wasto determine the dynamic characteristics and
the seismic behaviour of the proposed structures compared to
conventional structural systemsduring seismic motions. Results of
this study indicate that the interlock mechanism of the panels
influences the behaviour of lateral load-resisting systems of the
structures during earthquakes, contributing to better structural
flexibility and easier maintenance.
Abstract: Before performing polymerase chain reactions (PCR), a feasible primer set is required. Many primer design methods have been proposed for design a feasible primer set. However, the majority of these methods require a relatively long time to obtain an optimal solution since large quantities of template DNA need to be analyzed. Furthermore, the designed primer sets usually do not provide a specific PCR product. In recent years, evolutionary computation has been applied to PCR primer design and yielded promising results. In this paper, a particle swarm optimization (PSO) algorithm is proposed to solve primer design problems associated with providing a specific product for PCR experiments. A test set of the gene CYP1A1, associated with a heightened lung cancer risk was analyzed and the comparison of accuracy and running time with the genetic algorithm (GA) and memetic algorithm (MA) was performed. A comparison of results indicated that the proposed PSO method for primer design finds optimal or near-optimal primer sets and effective PCR products in a relatively short time.
Abstract: The mathematical modeling of storm surge in sea and
coastal regions such as the South China Sea (SCS) and the Gulf of
Thailand (GoT) are important to study the typhoon characteristics.
The storm surge causes an inundation at a lateral boundary exhibiting
in the coastal zones particularly in the GoT and some part of the SCS.
The model simulations in the three dimensional primitive equations
with a high resolution model are important to protect local properties
and human life from the typhoon surges. In the present study, the
mathematical modeling is used to simulate the typhoon–induced
surges in three case studies of Typhoon Linda 1997. The results
of model simulations at the tide gauge stations can describe the
characteristics of storm surges at the coastal zones.
Abstract: In this article, a high vacuum system for the evaporation of organic semiconductors is introduced and a mathematical model is given. Based on the exact input output linearization a deposition rate controller is designed and tested with different evaporation materials.
Abstract: Shrunken patterning for integrated device
manufacturing requires surface cleanliness and surface smoothness in
wet chemical processing [1]. It is necessary to control all process
parameters perfectly especially for the common cleaning technique
RCA clean (SC-1 and SC-2) [2]. In this paper the characteristic and
effect of surface preparation parameters are discussed. The properties
of RCA wet chemical processing in silicon technology is based on
processing time, temperature, concentration and megasonic power of
SC-1 and QDR. An improvement of wafer surface preparation by
the enhanced variables of the wet cleaning chemical process is
proposed.
Abstract: In recent years application of natural antimicrobials
instead of conventional ones, due to their hazardous effects on health,
has got serious attentions. On the basis of the results of different
studies, chitosan, a natural bio-degradable and non-toxic
biopolysaccharide derived from chitin, has potential to be used as a
natural antimicrobial. Chitosan has exhibited high antimicrobial
activity against a wide variety of pathogenic and spoilage
microorganisms, including fungi, and Gram-positive and Gramnegative
bacteria. The antimicrobial action is influenced by intrinsic
factors such as the type of chitosan, the degree of chitosan
polymerization and extrinsic factors such as the microbial organism,
the environmental conditions and presence of the other components.
The use of chitosan in food systems should be based on sufficient
knowledge of the complex mechanisms of its antimicrobial mode of
action. In this article we review a number of studies on the
investigation of chitosan antimicrobial properties and application of
them in culture and food mediums.
Abstract: In this paper, a novel system
recognition of human faces without using face
different color photographs is proposed. It mainly in
face detection, normalization and recognition. Foot
method of combination of Haar-like face determined
segmentation and region-based histogram stretchi
(RHST) is proposed to achieve more accurate perf
using Haar. Apart from an effective angle norm
side-face (pose) normalization, which is almost a might be important and beneficial for the prepr
introduced. Then histogram-based and photom
normalization methods are investigated and ada
retinex (ASR) is selected for its satisfactory illumin
Finally, weighted multi-block local binary pattern
with 3 distance measures is applied for pair-mat
Experimental results show its advantageous perfo
with PCA and multi-block LBP, based on a principle.