Abstract: Free convection effects and heat transfer due to a pulsating point heat source embedded in an infinite, fluid saturated, porous dusty medium are studied analytically. Both velocity and temperature fields are discussed in the form of series expansions in the Rayleigh number, for both the fluid and particle phases based on the mean heat generation rate from source and on the permeability of the porous dusty medium. This study is carried out by assuming the Rayleigh number small and the validity of Darcy-s law. Analytical expressions for both phases are obtained for second order mean in both velocity and temperature fields and evolution of different wave patterns are observed in the fluctuating part. It has been observed that, at the vicinity of the origin, the second order mean flow is influenced only by relaxation time of dust particles and not by dust concentration.
Abstract: Clustering is a very well known technique in data mining. One of the most widely used clustering techniques is the k-means algorithm. Solutions obtained from this technique are dependent on the initialization of cluster centers. In this article we propose a new algorithm to initialize the clusters. The proposed algorithm is based on finding a set of medians extracted from a dimension with maximum variance. The algorithm has been applied to different data sets and good results are obtained.
Abstract: A challenging problem in radar signal processing is to
achieve reliable target detection in the presence of interferences. In
this paper, we propose a novel algorithm for automatic censoring of
radar interfering targets in log-normal clutter. The proposed
algorithm, termed the forward automatic censored cell averaging
detector (F-ACCAD), consists of two steps: removing the corrupted
reference cells (censoring) and the actual detection. Both steps are
performed dynamically by using a suitable set of ranked cells to
estimate the unknown background level and set the adaptive
thresholds accordingly. The F-ACCAD algorithm does not require
any prior information about the clutter parameters nor does it require
the number of interfering targets. The effectiveness of the F-ACCAD
algorithm is assessed by computing, using Monte Carlo simulations,
the probability of censoring and the probability of detection in
different background environments.
Abstract: Lighting upgrades involve relatively lower costs which
allow the benefits to be spread more widely than is possible with any
other energy efficiency measure. In order to popularize the adoption of
CFL in Taiwan, the authority proposes to implement a new energy efficient lamp comparative label system. The current study was
accordingly undertaken to investigate the factors affecting the performance and the deviation of actual and labeled performance of
commercially available integrated CFLs. In this paper, standard test
methods to determine the electrical and photometric performances of
CFL were developed based on CIE 84-1989 and CIE 60901-1987,
then 55 selected CFLs from market were tested. The results show that
with higher color temperature of CFLs lower efficacy are achieved. It
was noticed that the most packaging of CFL often lack the information of Color Rendering Index. Also, there was no correlation between
price and performance of the CFLs was indicated in this work. The results of this paper might help consumers to make more informed
CFL-purchasing decisions.
Abstract: Atlantic herring (Clupea harengus) is an important
commercial fish and shows to be more and more demanded for
human consumption. Therefore, it is very important to find good
methods for monitoring the freshness of the fish in order to keep it in
the best quality for human consumption. In this study, the fish was
stored in ice up to 2 weeks. Quality changes during storage were
assessed by the Quality Index Method (QIM), quantitative
descriptive analysis (QDA) and Torry scheme, by texture
measurements: puncture tests and Texture Profile Analysis (TPA)
tests on texture analyzer TA.XT2i, and by electronic nose (e-nose)
measurements using FreshSense instrument. Storage time of herring
in ice could be estimated by QIM with ± 2 days using 5 herring per
lot. No correlation between instrumental texture parameters and
storage time or between sensory and instrumental texture variables
was found. E-nose measurements could be use to detect the onset of
spoilage.
Abstract: The purpose of this study is to analyze the islands
tourist travel information sources, as well as for the satisfaction of the
tourist destination services. This study used questionnaires to the
island of Taiwan to the Penghu Islands to engage in tourism activities
tourist adopt the designated convenience sampling method, a total of
889 valid questionnaires were collected. After statistical analysis, this
study found that: 1. tourists to the Penghu Islands travel information
source for “friends and family came to Penghu". 2. Tourists feel the
service of the outlying islands of Penghu, the highest feelings of
“friendly local residents". 3. There are different demographic variables
affect the tourist travel information source and service satisfaction.
Based on the findings of this study not only for Penghu's tourism
industry with the unit in charge of the proposed operating and
suggestions for future research to other researchers.
Abstract: The aim of the study was to evaluate the effect of
texturizers on the rheological properties of the apple mass and
desserts made from various raw materials. The apple varieties -
‘Antonovka’, ‘Baltais Dzidrais’, and ‘Zarja Alatau’ harvested in
Latvia, were used for the experiment. The apples were processed in a
blender unpeeled for obtaining a homogenous mass. The apple mass
was analyzed fresh and after storage at –18ºC. Both fresh and thawed
apple mass samples with added gelatin, xantan gum, and sodium
carboxymethylcellulose were whisked obtaining dessert. Pectin, pH
and soluble dry matter of the product were determined. Apparent
viscosity was measured using a rotational viscometer DV–III Ultra.
Pectin content in frozen apple mass decreased significantly (p
Abstract: Security issue and the importance of the function of
police to provide practical and psychological contexts in the
community has been the main topics among researchers , police and
security circles and this subject require to review and analysis
mechanisms within the police and its interaction with other parts of
the system for providing community safety. This paper examine
national and social security in the Internet.
Abstract: Querying a data source and routing data towards sink
becomes a serious challenge in static wireless sensor networks if sink
and/or data source are mobile. Many a times the event to be observed
either moves or spreads across wide area making maintenance of
continuous path between source and sink a challenge. Also, sink can
move while query is being issued or data is on its way towards sink.
In this paper, we extend our already proposed Grid Based Data
Dissemination (GBDD) scheme which is a virtual grid based
topology management scheme restricting impact of movement of
sink(s) and event(s) to some specific cells of a grid. This obviates the
need for frequent path modifications and hence maintains continuous
flow of data while minimizing the network energy consumptions.
Simulation experiments show significant improvements in network
energy savings and average packet delay for a packet to reach at sink.
Abstract: With the fast evolution of digital data exchange, security information becomes much important in data storage and transmission. Due to the increasing use of images in industrial process, it is essential to protect the confidential image data from unauthorized access. In this paper, we analyze the Advanced Encryption Standard (AES), and we add a key stream generator (A5/1, W7) to AES to ensure improving the encryption performance; mainly for images characterised by reduced entropy. The implementation of both techniques has been realized for experimental purposes. Detailed results in terms of security analysis and implementation are given. Comparative study with traditional encryption algorithms is shown the superiority of the modified algorithm.
Abstract: Every commercial bank optimises its asset portfolio
depending on the profitability of assets and chosen or imposed
constraints. This paper proposes and applies a stylized model for
optimising banks' asset and liability structure, reflecting profitability
of different asset categories and their risks as well as costs associated
with different liability categories and reserve requirements. The level
of detail for asset and liability categories is chosen to create a
suitably parsimonious model and to include the most important
categories in the model. It is shown that the most appropriate
optimisation criterion for the model is the maximisation of the ratio
of net interest income to assets. The maximisation of this ratio is
subject to several constraints. Some are accounting identities or
dictated by legislative requirements; others vary depending on the
market objectives for a particular bank. The model predicts variable
amount of assets allocated to loan provision.
Abstract: Vacuum membrane distillation (VMD) process can be
used for water purification or the desalination of salt water. The
process simply consists of a flat sheet hydrophobic micro porous
PTFE membrane and diaphragm vacuum pump without a condenser
for the water recovery or trap. The feed was used aqueous NaCl
solution. The VMD experiments were performed to evaluate the heat
and mass transfer coefficient of the boundary layer in a membrane
module. The only operating parameters are feed inlet temperature,
and feed flow rate were investigated. The permeate flux was strongly
affected by the feed inlet temperature, feed flow rate, and boundary
layer heat transfer coefficient. Since lowering the temperature
polarization coefficient is essential enhance the process performance
considerable and maximizing the heat transfer coefficient for
maximizes the mass flux of distillate water. In this paper, the results
of VMD experiments are used to measure the boundary layer heat
transfer coefficient, and the experimental results are used to reevaluate
the empirical constants in the Dittus- Boelter equation.
Abstract: The demand of the energy management systems (EMS) set forth by modern power systems requires fast energy management systems. Contingency analysis is among the functions in EMS which is time consuming. In order to handle this limitation, this paper introduces agent based technology in the contingency analysis. The main function of agents is to speed up the performance. Negotiations process in decision making is explained and the issue set forth is the minimization of the operating costs. The IEEE 14 bus system and its line outage have been used in the research and simulation results are presented.
Abstract: In this paper, an improved technique for contingency
ranking using artificial neural network (ANN) is presented. The
proposed approach is based on multi-layer perceptrons trained by
backpropagation to contingency analysis. Severity indices in dynamic
stability assessment are presented. These indices are based on the
concept of coherency and three dot products of the system variables.
It is well known that some indices work better than others for a
particular power system. This paper along with test results using
several different systems, demonstrates that combination of indices
with ANN provides better ranking than a single index. The presented
results are obtained through the use of power system simulation
(PSS/E) and MATLAB 6.5 software.
Abstract: The value of overall oxygen transfer Coefficient
(KLa), which is the best measure of oxygen transfer in water through
aeration, is obtained by a simple approach, which sufficiently
explains the utility of the method to eliminate the discrepancies due
to inaccurate assumption of saturation dissolved oxygen
concentration. The rate of oxygen transfer depends on number of
factors like intensity of turbulence, which in turns depends on the
speed of rotation, size, and number of blades, diameter and
immersion depth of the rotor, and size and shape of aeration tank, as
well as on physical, chemical, and biological characteristic of water.
An attempt is made in this paper to correlate the overall oxygen
transfer Coefficient (KLa), as an independent parameter with other
influencing parameters mentioned above. It has been estimated that
the simulation equation developed predicts the values of KLa and
power with an average standard error of estimation of 0.0164 and
7.66 respectively and with R2 values of 0.979 and 0.989 respectively,
when compared with experimentally determined values. The
comparison of this model is done with the model generated using
Computational fluid dynamics (CFD) and both the models were
found to be in good agreement with each other.
Abstract: In Grid computing, a data transfer protocol called
GridFTP has been widely used for efficiently transferring a large volume
of data. Currently, two versions of GridFTP protocols, GridFTP
version 1 (GridFTP v1) and GridFTP version 2 (GridFTP v2), have
been proposed in the GGF. GridFTP v2 supports several advanced
features such as data streaming, dynamic resource allocation, and
checksum transfer, by defining a transfer mode called X-block mode.
However, in the literature, effectiveness of GridFTP v2 has not been
fully investigated. In this paper, we therefore quantitatively evaluate
performance of GridFTP v1 and GridFTP v2 using mathematical
analysis and simulation experiments. We reveal the performance
limitation of GridFTP v1, and quantitatively show effectiveness of
GridFTP v2. Through several numerical examples, we show that by
utilizing the data streaming feature, the average file transfer time of
GridFTP v2 is significantly smaller than that of GridFTP v1.
Abstract: Object-oriented programming is a wonderful way to
make programming of huge real life tasks much easier than by using
procedural languages. In order to teach those ideas to students, it
is important to find a good task that shows the advantages of OOprogramming
very naturally. This paper gives an example, the game
Battleship, which seems to work excellent for teaching the OO ideas
(using Java, [1], [2], [3], [4]).
A three-step task is presented for how to teach OO-programming
using just one example suitable to convey many of the OO ideas.
Observations are given at the end and conclusions about how the
whole teaching course worked out.
Abstract: The paper outlines the relevance of computational
geometry within the design and production process of architecture.
Based on two case studies, the digital chain - from the initial formfinding
to the final realization of spatial concepts - is discussed in
relation to geometric principles. The association with the fascinating
complexity that can be found in nature and its underlying geometry
was the starting point for both projects presented in the paper. The
translation of abstract geometric principles into a three-dimensional
digital design model – realized in Rhinoceros – was followed by a
process of transformation and optimization of the initial shape that
integrated aesthetic, spatial and structural qualities as well as aspects
of material properties and conditions of production.
Abstract: In this paper, we present the design and experimental
evaluation of complementary energy path adiabatic logic (CEPAL)
based 1 bit full adder circuit. A simulative investigation on the
proposed full adder has been done using VIRTUOSO SPECTRE
simulator of cadence in 0.18μm UMC technology and its
performance has been compared with the conventional CMOS full
adder circuit. The CEPAL based full adder circuit exhibits the energy
saving of 70% to the conventional CMOS full adder circuit, at 100
MHz frequency and 1.8V operating voltage.
Abstract: Heart-s electric field can be measured anywhere on
the surface of the body (ECG). When individuals touch, one person-s
ECG signal can be registered in other person-s EEG and elsewhere
on his body. Now, the aim of this study was to test the hypothesis
that physical contact (hand-holding) of two persons changes their
heart rate variability. Subjects were sixteen healthy female (age: 20-
26) which divided into eight sets. In each sets, we had two friends
that they passed intimacy test of J.sternberg. ECG of two subjects
(each set) acquired for 5 minutes before hand-holding (as control
group) and 5 minutes during they held their hands (as experimental
group). Then heart rate variability signals were extracted from
subjects' ECG and analyzed in linear feature space (time and
frequency domain) and nonlinear feature space. Considering the
results, we conclude that physical contact (hand-holding of two
friends) increases parasympathetic activity, as indicate by increase
SD1, SD1/SD2, HF and MF power (p