Abstract: A study on the performance of TCP Vegas versus
different TCP variants in homogeneous and heterogeneous wired
networks are performed via simulation experiment using network
simulator (ns-2). This performance evaluation prepared a comparison
medium for the performance evaluation of enhanced-TCP Vegas in
wired network and for wireless network. In homogeneous network,
the performance of TCP Tahoe, TCP Reno, TCP NewReno, TCP
Vegas and TCP SACK are analyzed. In heterogeneous network, the
performances of TCP Vegas against TCP variants are analyzed. TCP
Vegas outperforms other TCP variants in homogeneous wired
network. However, TCP Vegas achieves unfair throughput in
heterogeneous wired network.
Abstract: The aim of this study was to investigate the effects of
supplementing the diluent of roosters' semen with different levels of
olive oil on motility, viability, morphology and acrosome integrity of
chicken spermatozoa after in vitro storage for up to 72 h. Semen was
collected from 60 White Layer males (62 wk of age) kept in
separated floor pens and randomly divided into six treatment groups
(10 males in each group). Experimental groups were as follows: T1
:fresh semen, T2 : semen extended 1:1 with Al – Daraji 2 diluent
(AD2D) alone, T3 – T6 :semen samples extended 1:1 with AD2D
supplemented with 2 ml, 4 ml, 6 ml or 8 ml of olive oil / 100 ml of
diluent, respectively. Semen samples were then stored at 5 °C for 24
h, 48 h or 72 h. There was a clear influence of diluent
supplementation with olive oil on the spermatozoa motility profile;
olive oil groups (T3, T4, T5 and T6) recorded the highest scores of
mass activity and individual motility during all storage periods
compared to T1 and T2 groups. In addition, the inclusion of olive oil
into semen diluent (T3, T4, T5 and T6) gave significantly higher
percentages of viable spermatozoa, normal morphologically
spermatozoa and intact acrosomes irrespective of storage period.
These results clearly show that supplementation the diluent of
roosters' semen with olive oil can improve semen quality when
semen samples in vitro stored at 5 °C for up to 72 h.
Abstract: The aim of this research is to evaluate surface
roughness and develop a multiple regression model for surface roughness as a function of cutting parameters during the turning of
flame hardened medium carbon steel with TiN-Al2O3-TiCN coated inserts. An experimental plan of work and signal-to-noise ratio (S/N)
were used to relate the influence of turning parameters to the
workpiece surface finish utilizing Taguchi methodology. The effects
of turning parameters were studied by using the analysis of variance (ANOVA) method. Evaluated parameters were feed, cutting speed,
and depth of cut. It was found that the most significant interaction among the considered turning parameters was between depth of cut and feed. The average surface roughness (Ra) resulted by TiN-Al2O3-
TiCN coated inserts was about 2.44 μm and minimum value was 0.74 μm. In addition, the regression model was able to predict values for surface roughness in comparison with experimental values within
reasonable limit.
Abstract: This paper presents a 24 watts SEPIC converter design
and control using microprocessor. SEPIC converter has advantages of
a wide input range and miniaturization caused by the low stress at
elements. There is also an advantage that the input and output are
isolated in MOSFET-off state. This paper presents the PID control
through the SEPIC converter transfer function using a DSP and the
protective circuit for fuel cell from the over-current and
inverse-voltage by using the characteristic of SEPIC converter. Then it
derives them through the experiments.
Abstract: The amplitude response of infrared (IR) sensors
depends on the reflectance properties of the target. Therefore, in
order to use IR sensor for measuring distances accurately, prior
knowledge of the surface must be known. This paper describes the
Phong Illumination Model for determining the properties of a surface
and subsequently calculating the distance to the surface. The angular
position of the IR sensor is computed as normal to the surface for
simplifying the calculation. Ultrasonic (US) sensor can provide the
initial information on distance to obtain the parameters for this
method. In addition, the experimental results obtained by using
LabView are discussed. More care should be taken when placing the
objects from the sensors during acquiring data since the small change
in angle could show very different distance than the actual one.
Since stereo camera vision systems do not perform well under some
environmental conditions such as plain wall, glass surfaces, or poor
lighting conditions, the IR and US sensors can be used additionally to
improve the overall vision systems of mobile robots.
Abstract: In this paper, an image adaptive, invisible digital
watermarking algorithm with Orthogonal Polynomials based
Transformation (OPT) is proposed, for copyright protection of digital
images. The proposed algorithm utilizes a visual model to determine
the watermarking strength necessary to invisibly embed the
watermark in the mid frequency AC coefficients of the cover image,
chosen with a secret key. The visual model is designed to generate a
Just Noticeable Distortion mask (JND) by analyzing the low level
image characteristics such as textures, edges and luminance of the
cover image in the orthogonal polynomials based transformation
domain. Since the secret key is required for both embedding and
extraction of watermark, it is not possible for an unauthorized user to
extract the embedded watermark. The proposed scheme is robust to
common image processing distortions like filtering, JPEG
compression and additive noise. Experimental results show that the
quality of OPT domain watermarked images is better than its DCT
counterpart.
Abstract: In this paper we investigate the influence of external
noise on the inference of network structures. The purpose of our
simulations is to gain insights in the experimental design of microarray
experiments to infer, e.g., transcription regulatory networks
from microarray experiments. Here external noise means, that the
dynamics of the system under investigation, e.g., temporal changes of
mRNA concentration, is affected by measurement errors. Additionally
to external noise another problem occurs in the context of microarray
experiments. Practically, it is not possible to monitor the mRNA
concentration over an arbitrary long time period as demanded by the
statistical methods used to learn the underlying network structure. For
this reason, we use only short time series to make our simulations
more biologically plausible.
Abstract: Abrasive Jet Machining is an Unconventional
machining process in which the metal is removed from brittle and
hard material in the form of micro-chips. With increase in need of
materials like ceramics, composites, in manufacturing of various
Mechanical & Electronic components, AJM has become a useful
technique for micro machining. The present study highlights the
influence of different parameters like Pressure, SOD, Time, Abrasive
grain size, nozzle diameter on the Metal removal of FRP (Fiber
Reinforced Polymer) composite by Abrasive jet machining. The
results of the Experiments conducted were analyzed and optimized
with TAGUCHI method of Optimization and ANOVA for Optimal
Value.
Abstract: Nowadays, the performance required for concrete
structures is more complicated and diversified. Self-compacting
concrete is a fluid mixture suitable for placing in structures with
congested reinforcement without vibration. Self-compacting concrete
development must ensure a good balance between deformability and
stability. Also, compatibility is affected by the characteristics of
materials and the mix proportions; it becomes necessary to evolve a
procedure for mix design of SCC.
This paper presents an experimental procedure for the design of
self-compacting concrete mixes with different water-cement ratios
(w/c) and other constant ratios by local materials. The test results for
acceptance characteristics of self-compacting concrete such as slump
flow, V-funnel and L-Box are presented. Further, compressive
strength, tensile strength and modulus of elasticity of specimens were
also determined and results are included here
Abstract: In this paper a three dimensional thermal model of a
sliding contact system is proposed for both steady-state or transient
conditions. The influence of contact force, electric current and
ambient temperature on the temperature distribution, has been
investigated. A thermal analysis of the different type of the graphite
material of fixed electric contact and its influence on contact system
temperature rise, has been performed. To validate the three
dimensional thermal model, some experimental tests have been done.
There is a good correlation between experimental and simulation
results.
Abstract: In this paper a hybrid technique of Genetic Algorithm
and Simulated Annealing (HGASA) is applied for Fractal Image
Compression (FIC). With the help of this hybrid evolutionary
algorithm effort is made to reduce the search complexity of matching
between range block and domain block. The concept of Simulated
Annealing (SA) is incorporated into Genetic Algorithm (GA) in order
to avoid pre-mature convergence of the strings. One of the image
compression techniques in the spatial domain is Fractal Image
Compression but the main drawback of FIC is that it involves more
computational time due to global search. In order to improve the
computational time along with acceptable quality of the decoded
image, HGASA technique has been proposed. Experimental results
show that the proposed HGASA is a better method than GA in terms
of PSNR for Fractal image Compression.
Abstract: Repairing of the cracks by fiber metal laminates
(FMLs) was first done by some aeronautical laboratories in early
1970s. In this study, experimental investigations were done on the
effect of repairing the center-cracked aluminum plates using the FML
patches. The repairing processes were conducted to characterize the
response of the repaired structures to tensile tests. The composite
patches were made of one aluminum layer and two woven glassepoxy
composite layers. Three different crack lengths in three crack
angles and different patch lay-ups were examined. It was observed
for the lengthen cracks, the effect of increasing the crack angle on
ultimate tensile load in the structure was increase. It was indicated
that the situation of metal layer in the FML patches had an important
effect on the tensile response of the tested specimens. It was found
when the aluminum layer is farther, the ultimate tensile load has the
highest amount.
Abstract: Along with the basic features of students\' culture
information, with its widely usage oriented on implementation of the
new information technologies in educational process that determines
the search for ways of pointing to the similarity of interdisciplinary
connections content, aims and objectives of the study. In this regard,
the article questions about students\' information culture, and also
presented information about the aims and objectives of the
information culture process among students. In the formation of a
professional interest in relevant information, which is an opportunity
to assist in informing the professional activities of the essence of
effective use of interactive methods and innovative technologies in
the learning process. The result of the experiment proves the
effectiveness of the information culture process of students in
training the system of higher education based on the credit
technology. The main purpose of this paper is a comprehensive
review of students\' information culture.
Abstract: Microarray experiments are information rich; however, extensive data mining is required to identify the patterns that characterize the underlying mechanisms of action. For biologists, a key aim when analyzing microarray data is to group genes based on the temporal patterns of their expression levels. In this paper, we used an iterative clustering method to find temporal patterns of gene expression. We evaluated the performance of this method by applying it to real sporulation data and simulated data. The patterns obtained using the iterative clustering were found to be superior to those obtained using existing clustering algorithms.
Abstract: The selective recovery of heavy metals of Cu, Zn, Ni and Cr from a mixed plating sludge by sulfidation and oxidation treatment was targeted in this study. At first, the mixed plating sludge was simultaneously subjected to an extraction and Cu sulfidation process at pH=1.5 to dissolve heavy metals and to precipitate Cu2+ as CuS. In the next step, the sulfidation treatment of Zn was carried out at pH=4.5 and the residual solution was subjected to an oxidation treatment of chromium with H2O2 at pH=10.0. After the experiments, the selectivity of metal precipitation and the chromium oxidation ratio were evaluated. As results, it was found that the filter cake obtained after selective sulfidation of Cu was composed of 96.6% of Cu (100% equals to the sum of Cu, Zn, Ni and Cr contents). Such findings confirmed that almost complete extraction of heavy metals was achieved at pH=1.5 and also that Cu could be selectively recovered as CuS. Further, the filter cake obtained at pH=4.5 was composed of 91.5% Zn and 6.83% of Cr. Regarding the chromium oxidation step, the chromium oxidation ratio was found to increase with temperature and the addition of oxidation agent of H2O2, but only oxidation ratio of 59% was achieved at a temperature of 60°C and H2O2 to Cr3+ equivalent ratio of 180.
Abstract: It is very important to determine reference temperature when convective temperature because it should be used to calculate the temperature potential. This paper deals with the development of a new method that can determine heat transfer coefficient and reference free stream temperature simultaneously, based on transient heat transfer experiments with using two narrow band thermo-tropic liquid crystals (TLC's). The method is validated through error analysis in terms of the random uncertainties in the measured temperatures. It is shown how the uncertainties in heat transfer coefficient and free stream temperature can be reduced. The general method described in this paper is applicable to many heat transfer models with unknown free stream temperature.
Abstract: This paper presents the experimental results of
comparison between leakage currents and discharge currents. The leakage currents were obtained on polluted porcelain insulator.
Whereas, the discharge currents were obtained on lightly artificial
polluted porcelain specimen. The conducted measurements were
leakage current or discharge current and applied voltage. The insulator or specimen was in a hermetically sealed chamber, and the
current waveforms were analyzed using FFT.
The result indicated that the leakage current (LC) on low RH condition the fifth harmonic would be visible, and followed by the
seventh harmonic. The insulator had capacitive property. Otherwise,
on 99% relative humidity, the fifth harmonic would also be visible,
and the phase angle reached up to 12.2 degree. Whereas, on discharge current, the third harmonic would be visible, and followed
by fifth harmonic. The third harmonic would increase as pressure reduced. On this condition, the specimen had a non-linear characteristics
Abstract: Flow-shop scheduling problem (FSP) deals with the
scheduling of a set of jobs that visit a set of machines in the same
order. The FSP is NP-hard, which means that an efficient algorithm
for solving the problem to optimality is unavailable. To meet the
requirements on time and to minimize the make-span performance of
large permutation flow-shop scheduling problems in which there are
sequence dependent setup times on each machine, this paper
develops one hybrid genetic algorithms (HGA). Proposed HGA
apply a modified approach to generate population of initial
chromosomes and also use an improved heuristic called the iterated
swap procedure to improve initial solutions. Also the author uses
three genetic operators to make good new offspring. The results are
compared to some recently developed heuristics and computational
experimental results show that the proposed HGA performs very
competitively with respect to accuracy and efficiency of solution.
Abstract: This study assessed the effects of climate change on
Thai soybeans under simulation situations. Our study is focused on
temperature variability and effects on growth, yield, and genetic
changes in 2 generations of Chiang Mai 60 cultivars. In the
experiment, soybeans were exposed to 3 levels of air temperature for
8 h day-1 in an open top chamber for 2 cropping periods. Air
temperature levels in each treatment were controlled at 30-33°C (±
2.3) for LT-treatment, 33-36°C ( ± 2.4) for AT-treatment, and 36-40
°C ( ± 3.2) for HT-treatment, respectively. Positive effects of high
temperature became obvious at the maturing stage when yield
significantly increased in both cropping periods. Results in growth
indicated that shoot length at the pre-maturing stage
(V3-R3) was more positively affected by high temperature than at the
maturing stage. However, the positive effect on growth under high
temperature was not found in the 2nd cropping period. Finally, genetic
changes were examined in phenotype characteristics by the AFLPs
technique. The results showed that the high temperature factor clearly
caused genetic change in the soybeans and showed more alteration in
the 2nd cropping period.