Abstract: Short circuit currents plays a vital role in influencing the design and operation of equipment and power system and could not be avoided despite careful planning and design, good maintenance and thorough operation of the system. This paper discusses the short circuit analysis conducted in KSO briefly comprising of its significances, methods and results. A result sample of the analysis based on a single transformer is detailed in this paper. Furthermore, the results of the analysis and its significances were also discussed and commented.
Abstract: Phase locked loops for data links operating at 10 Gb/s
or faster are low phase noise devices designed to operate with a low
jitter reference clock. Characterization of their jitter transfer function
is difficult because the intrinsic noise of the device is comparable to
the random noise level in the reference clock signal. A linear model
is proposed to account for the intrinsic noise of a PLL. The intrinsic
noise data of a PLL for 10 Gb/s links is presented. The jitter transfer
function of a PLL in a test chip for 12.8 Gb/s data links was
determined in experiments using the 400 MHz reference clock as the
source of simultaneous excitations over a wide range of frequency.
The result shows that the PLL jitter transfer function can be
approximated by a second order linear model.
Abstract: In the traditional theory of non-uniform torsion the
axial displacement field is expressed as the product of the unit twist
angle and the warping function. The first one, variable along the
beam axis, is obtained by a global congruence condition; the second
one, instead, defined over the cross-section, is determined by solving
a Neumann problem associated to the Laplace equation, as well as for
the uniform torsion problem.
So, as in the classical theory the warping function doesn-t punctually
satisfy the first indefinite equilibrium equation, the principal aim of
this work is to develop a new theory for non-uniform torsion of
beams with axial symmetric cross-section, fully restrained on both
ends and loaded by a constant torque, that permits to punctually
satisfy the previous equation, by means of a trigonometric expansion
of the axial displacement and unit twist angle functions.
Furthermore, as the classical theory is generally applied with good
results to the global and local analysis of ship structures, two beams
having the first one an open profile, the second one a closed section,
have been analyzed, in order to compare the two theories.
Abstract: This paper undertakes the problem of optimal
capacitor placement in a distribution system. The problem is how to
optimally determine the locations to install capacitors, the types and
sizes of capacitors to he installed and, during each load level,the
control settings of these capacitors in order that a desired objective
function is minimized while the load constraints,network constraints
and operational constraints (e.g. voltage profile) at different load
levels are satisfied. The problem is formulated as a combinatorial
optimization problem with a nondifferentiable objective function.
Four solution mythologies based on algorithms (GA),tabu search
(TS), and hybrid GA-SA algorithms are presented.The solution
methodologies are preceded by a sensitivity analysis to select the
candidate capacitor installation locations.
Abstract: This research focuses on the use of a recommender
system in decision support by means of a used car dealer case study
in Bangkok Metropolitan. The goal is to develop an effective used car
purchasing system for dealers based on the above premise. The
underlying principle rests on content-based recommendation from a
set of usability surveys. A prototype was developed to conduct
buyers- survey selected from 5 experts and 95 general public. The
responses were analyzed to determine the mean and standard
deviation of buyers- preference. The results revealed that both groups
were in favor of using the proposed system to assist their buying
decision. This indicates that the proposed system is meritorious to
used car dealers.
Abstract: The effect of cassava root ensiled with cassava top or
legumes on voluntary feed intake and milk production were
determined in 12 dairy cows using a 4×3 change-over design.
Experimental period were 30 days long and consisted of 14 days of
adaptation. Silage was prepared from cassava root mixed with
cassava top or legumes at ratio 60:40. Cows were allotted at random
to receive ad libitum one of four rations: T1) control, T2) cassava
root +cassava top-silages, T3) cassava root +hamata - silages and T4)
cassava root +Thapra stylo-silages.
The dry matter intake (BW0.75) was higher (P< 0.05) in cow fed
with silages diets compared with T1. However, the intake of T2 was
higher among treatments. Milk production was lowest in cow fed
with T1. Among silages based diets, milk production was not
significantly different but 4%FCM was higher in cow fed T2. Milk
compositions were not affected by feeding diets.
It is concluded that feeding cassava root ensiled with its leaves as
a supplement increased dry matter intake and significantly improved
4%FCM. The combination of cassava root and legume silages did not
improve the feed intake but did increase the milk production.
Abstract: The objectives of this study are to determine the role of media that influence the values, attitudes and behaviors of Thai youths. Analytical qualitative research techniques were used for this purpose. Data collection based techniques was used which were individual interviews and focus group discussions with journalists, sample of high school and university students, and parents. The results show that “Social Media" is still the most popular media for Thai youths. It is also still in the hands of the marketing business and it can motivate Thai youths to do so many things. The main reasons of media exposure are to find quality information that they want quickly, get satisfaction and can use social media to get more exciting and to build communities. They believe that the need for media and information literacy skills is defined as making judgments, personal integrity, training of family and the behavior of close friends.
Abstract: In this paper we introduce three watermarking methods that can be used to count the number of times that a user has played some content. The proposed methods are tested with audio content in our experimental system using the most common signal processing attacks. The test results show that the watermarking methods used enable the watermark to be extracted under the most common attacks with a low bit error rate.
Abstract: Voltage flicker is a disturbance in electrical power
systems. The reason for this disturbance is mainly the large nonlinear
loads such as electric arc furnaces. Synchronous static
compensator (STATCOM) is considered as a proper technique to
mitigate the voltage flicker. Application of more suitable and precise
power electronic converter leads to a more precise performance of the
compensator. In this paper a three-level 12-pulse voltage source
inverter (VSI) with a 12-terminal transformer connected to the ac
system is studied and the obtained results are compared with the
performance of a STATCOM using a simple two-level VSI and an
optimal and more precise performance of the proposed scheme is
achieved.
Abstract: Multi-residue analysis method for penicillins was
developed and validated in bovine muscle, chicken, milk, and flatfish.
Detection was based on liquid chromatography tandem mass
spectrometry (LC/MS/MS). The developed method was validated for
specificity, precision, recovery, and linearity. The analytes were
extracted with 80% acetonitrile and clean-up by a single
reversed-phase solid-phase extraction step. Six penicillins presented
recoveries higher than 76% with the exception of Amoxicillin
(59.7%). Relative standard deviations (RSDs) were not more than
10%. LOQs values ranged from 0.1 and to 4.5 ug/kg. The method was
applied to 128 real samples. Benzylpenicillin was detected in 15
samples and Cloxacillin was detected in 7 samples. Oxacillin was
detected in 2 samples. But the detected levels were under the MRL
levels for penicillins in samples.
Abstract: High voltage generators are being subject to higher
voltage rating and are being designed to operate in harsh conditions.
Stator windings are the main component of generators in which
Electrical, magnetically and thermal stresses remain major failures
for insulation degradation accelerated aging. A large number of
generators failed due to stator winding problems, mainly insulation
deterioration. Insulation degradation assessment plays vital role in the
asset life management. Mostly the stator failure is catastrophic
causing significant damage to the plant. Other than generation loss,
stator failure involves heavy repair or replacement cost. Electro
thermal analysis is the main characteristic for improvement design of
stator slot-s insulation. Dielectric parameters such as insulation
thickness, spacing, material types, geometry of winding and slot are
major design consideration. A very powerful method available to
analyze electro thermal performance is Finite Element Method
(FEM) which is used in this paper. The analysis of various stator coil
and slot configurations are used to design the better dielectric system
to reduce electrical and thermal stresses in order to increase the
power of generator in the same volume of core. This paper describes
the process used to perform classical design and improvement
analysis of stator slot-s insulation.
Abstract: The recurring decimal of rural and urban poverty in
Nigeria, resulting from lack of sustainable livelihood activities by
the people due to non-diversification of the economy, necessitated
this study. One hundred snail farmers were randomly selected in
Akure North and Akure South Local Government areas of Ondo
State, Southwest Nigeria where snail farming is widely practised.
Data collection was through questionnaires administration and onsite
observation of farms. Data obtained were subjected to
descriptive statistics, Student-s t-test and regression analysis. Cost
benefit ratio (CBR) and rate of return on investment (RORI) were
calculated in order to determine the poverty alleviation potentials of
snail farming in the study areas. Although snail farming was
profitable and viable, it was below poverty line. With time and more
knowledge in its farming activities, and with more people taking to
snail production, its poverty alleviation and reduction potentials will
increase.
Abstract: Polymers are one of the most widely used materials in our every day life. The subject of renewable resources has attracted great attention in the last period of time. New polymeric materials derived from renewable resources, like carbohydrates draw attention to public eye especially because of their biocompatibility and biodegradability. The aim of our paper was to obtain environmentally compatible polymers from monosaccharides. Novel glycopolymers based on D-glucose have been obtained from copolymerization of a new monomer carrying carbohydrate moiety with methyl methacrylate (MMA) via free radical bulk polymerization. Differential scanning calorimetry (DSC) was performed in order to study the copolymerization process of the monomer into the chosen co-monomer; the activation energy of this process was evaluated using Ozawa method. The copolymers obtained were characterized using ATR-FTIR spectroscopy. The thermal stability of the obtained products was studied by thermogravimetry (TG).
Abstract: The goal of this paper is to find Wardrop equilibrium
in transport networks at case of uncertainty situations, where the
uncertainty comes from lack of information. We use simulation tool
to find the equilibrium, which gives only approximate solution, but
this is sufficient for large networks as well. In order to take the
uncertainty into account we have developed an interval-based
procedure for finding the paths with minimal cost using the
Dempster-Shafer theory. Furthermore we have investigated the users-
behaviors using game theory approach, because their path choices
influence the costs of the other users- paths.
Abstract: The research study is carried out to determine the efficiency of the Biofilm sewage treatment plant which is located at the Engineering Complex-s. Wastewater analyses have been carried out at the Environmental Engineering laboratory to study the six parameters: Biochemical Oxygen Demand BOD, Chemical Oxygen Demand COD l, and Total Suspended Solids TSS, Ammoniac Nitrogen NH3-N and Phosphorous P which have been selected to determine the wastewater quality. The plant was designed to treat 750 Pe (population equivalent) at hydraulic retention time of 5 hours in the aerobic zone. The results show that Biofilm wastewater treatment plant was able to treat sewage successfully at different flow condition. The discharge has fulfilled the Malaysia Environmental of Standard A water quality. The achieved BOD removal is more than 85%, COD is more than 80%, TSS is more than 80%, NH3-N is more than 70%, and P was more than 70%. The Biofilm system provides a very efficient process for sewage treatment and it is compact in structure thus minimizes the required land area.
Abstract: Commercial nanocomposite food packaging type nano-silver containers were characterised using scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDX). The presence of nanoparticles consistent with the incorporation of 1% nano-silver (Ag) and 0.1% titanium dioxide (TiO2) nanoparticle into polymeric materials formed into food containers was confirmed. Both nanomaterials used in this type of packaging appear to be embedded in a layered configuration within the bulk polymer. The dimensions of the incorporated nanoparticles were investigated using X-ray diffraction (XRD) and determined by calculation using the Scherrer Formula; these were consistent with Ag and TiO2 nanoparticles in the size range 20-70nm both were spherical shape nanoparticles. Antimicrobial assessment of the nanocomposite container has also been performed and the results confirm the antimicrobial activity of Ag and TiO2 nanoparticles in food packaging containers. Migration assessments were performed in a wide range of food matrices to determine the migration of nanoparticles from the packages. The analysis was based upon the relevant European safety Directives and involved the application of inductively coupled plasma mass spectrometry (ICP-MS) to identify the range of migration risk. The data pertain to insignificance levels of migration of Ag and TiO2 nanoparticles into the selected food matrices.
Abstract: This paper presents the exergy analysis of a
desalination unit using humidification-dehumidification process.
Here, this unit is considered as a thermal system with three main
components, which are the heating unit by using a solar collector, the
evaporator or the humidifier, and the condenser or the dehumidifier.
In these components the exergy is a measure of the quality or grade
of energy and it can be destroyed in them. According to the second
law of thermodynamics this destroyed part is due to irreversibilities
which must be determined to obtain the exergetic efficiency of the
system.
In the current paper a computer program has been developed using
visual basic to determine the exergy destruction and the exergetic
efficiencies of the components of the desalination unit at variable
operation conditions such as feed water temperature, outlet air
temperature, air to feed water mass ratio and salinity, in addition to
cooling water mass flow rate and inlet temperature, as well as
quantity of solar irradiance.
The results obtained indicate that the exergy efficiency of the
humidifier increases by increasing the mass ratio and decreasing the
outlet air temperature. In the other hand the exergy efficiency of the
condenser increases with the increase of this ratio and also with the
increase of the outlet air temperature.
Abstract: The increasingly sophisticated technologies have now been able to provide assistance for surgeons to improve surgical
performance through various training programs. Equally important to learning skills is the assessment method as it determines the learning and technical proficiency of a trainee. A consistent and
rigorous assessment system will ensure that trainees acquire the specific level of competency prior to certification. This paper
reviews the methods currently in use for assessment of surgical
skill and some modern techniques using computer-based
measurements and virtual reality systems for more quantitative
measurements
Abstract: It is a challenge to provide a wide range of queries to
database query systems for small mobile devices, such as the PDAs
and cell phones. Currently, due to the physical and resource
limitations of these devices, most reported database querying systems
developed for them are only offering a small set of pre-determined
queries for users to possibly pose. The above can be resolved by
allowing free-form queries to be entered on the devices. Hence, a
query language that does not restrict the combination of query terms
entered by users is proposed. This paper presents the free-form query
language and the method used in translating free-form queries to
their equivalent SQL statements.
Abstract: Gradual patterns have been studied for many years as
they contain precious information. They have been integrated in
many expert systems and rule-based systems, for instance to reason
on knowledge such as “the greater the number of turns, the greater
the number of car crashes”. In many cases, this knowledge has been
considered as a rule “the greater the number of turns → the greater
the number of car crashes” Historically, works have thus been
focused on the representation of such rules, studying how implication
could be defined, especially fuzzy implication. These rules were
defined by experts who were in charge to describe the systems they
were working on in order to turn them to operate automatically. More
recently, approaches have been proposed in order to mine databases
for automatically discovering such knowledge. Several approaches
have been studied, the main scientific topics being: how to determine
what is an relevant gradual pattern, and how to discover them as
efficiently as possible (in terms of both memory and CPU usage).
However, in some cases, end-users are not interested in raw level
knowledge, and are rather interested in trends. Moreover, it may be
the case that no relevant pattern can be discovered at a low level of
granularity (e.g. city), whereas some can be discovered at a higher
level (e.g. county). In this paper, we thus extend gradual pattern
approaches in order to consider multiple level gradual patterns. For
this purpose, we consider two aggregation policies, namely
horizontal and vertical.