Abstract: Design of Converter transformer insulation is a major
challenge. The insulation of these transformers is stressed by both
AC and DC voltages. Particle contamination is one of the major
problems in insulation structures, as they generate partial discharges
leading it to major failure of insulation. Similarly corona discharges
occur in transformer insulation. This partial discharge due to particle
movement / corona formation in insulation structure under different
voltage wave shapes, are different. In the present study, UHF
technique is adopted to understand the discharge activity and could
be realized that the characteristics of UHF signal generated under
low and high fields are different. In the case of corona generated
signal, the frequency content of the UHF sensor output lies in the
range 0.3-1.2 GHz and is not much varied except for its increase in
magnitude of discharge with the increase in applied voltage. It is
realized that the current signal injected due to partial
discharges/corona is about 4ns duration measured for first one half
cycle. Wavelet technique is adopted in the present study. It allows
one to identify the frequency content present in the signal at different
instant of time. The STD-MRA analysis helps one to identify the
frequency band in which the energy content of the UHF signal is
maximum.
Abstract: The performances of a thermoacoustic travelling-wave
refrigerator are presented. Developed in the frame of the European
project called THATEA, it is designed for providing 600 W at a
temperature of 233 K with an efficiency of 40 % relative to the
Carnot efficiency. This paper presents the device and the results of
the first measurements. For a cooling power of 210 W, a coefficient
of performance relative to Carnot of 30 % is achieved when the
refrigerator is coupled with an existing standing-wave engine.
Abstract: Microwave heating process has been developed about sixty years while measurement system has also progressed. Because of irradiation of high frequency of microwave, researchers have been utilized many costly technical instrument measuring parameters to evaluate the performance of microwave heating system. Therefore, this paper is intended to present an easier and feasible efficiency measurement method. It can help inspecting efficiency of microwave heating system with good accuracy, while the method can also give reference to optimizing procedure for microwave heating system for various load material
Abstract: In competitive electricity markets all over the world, an adoption of suitable transmission pricing model is a problem as transmission segment still operates as a monopoly. Transmission pricing is an important tool to promote investment for various transmission services in order to provide economic, secure and reliable electricity to bulk and retail customers. The nodal pricing based on SRMC (Short Run Marginal Cost) is found extremely useful by researchers for sending correct economic signals. The marginal prices must be determined as a part of solution to optimization problem i.e. to maximize the social welfare. The need to maximize the social welfare subject to number of system operational constraints is a major challenge from computation and societal point of views. The purpose of this paper is to present a nodal transmission pricing model based on SRMC by developing new mathematical expressions of real and reactive power marginal prices using GA-Fuzzy based optimal power flow framework. The impacts of selecting different social welfare functions on power marginal prices are analyzed and verified with results reported in literature. Network revenues for two different power systems are determined using expressions derived for real and reactive power marginal prices in this paper.
Abstract: Solid oxide fuel cells have been considered in the last years as one of the most promising technologies for very highefficiency electric energy generation from hydrogen or other hydrocarbons, both with simple fuel cell plants and with integrated gas turbine-fuel cell systems. In the present study, a detailed thermodynamic analysis has been carried out. Mass and exergy balances are performed not only for the whole plant but also for each component in order to evaluate the thermal efficiency of combined cycle. Moreover, different sources of irreversibilities within the SOFC stack have been discussed and a parametric study conducted to evaluate the effect of temperature as well as pressure on SOFC irreversibilities and its performance. In this investigation methane and hydrogen have been used for fueling the SOFC stack and combustion chamber.
Abstract: Support Vector Machine (SVM) is a statistical
learning tool that was initially developed by Vapnik in 1979 and later
developed to a more complex concept of structural risk minimization
(SRM). SVM is playing an increasing role in applications to
detection problems in various engineering problems, notably in
statistical signal processing, pattern recognition, image analysis, and
communication systems. In this paper, SVM was applied to the
detection of SAR (synthetic aperture radar) images in the presence of
partially developed speckle noise. The simulation was done for single
look and multi-look speckle models to give a complete overlook and
insight to the new proposed model of the SVM-based detector. The
structure of the SVM was derived and applied to real SAR images
and its performance in terms of the mean square error (MSE) metric
was calculated. We showed that the SVM-detected SAR images have
a very low MSE and are of good quality. The quality of the
processed speckled images improved for the multi-look model.
Furthermore, the contrast of the SVM detected images was higher
than that of the original non-noisy images, indicating that the SVM
approach increased the distance between the pixel reflectivity levels
(the detection hypotheses) in the original images.
Abstract: Collected data must be organized to be utilized efficiently, and hierarchical classification of data is efficient approach to organize data. When data is classified to multiple categories or annotated with a set of labels, users request multi-labeled data by giving a set of labels. There are several interpretations of the data expressed by a set of labels. This paper discusses which data is expressed by a set of labels by introducing orders for sets of labels and shows that there are four types of orders, which are characterized by whether the labels of expressed data includes every label of the given set of labels within the range of the set. Desirable properties of the orders, data is also expressed by the higher set of labels and different sets of labels express different data, are discussed for the orders.
Abstract: In this work, statistical experimental design was
applied for the optimization of medium constituents for Gentamicin
production by Micromsonospora echinospora subs pallida (MTCC
708) in a batch reactor and the results are compared with the ANN
predicted values. By central composite design, 50 experiments are
carried out for five test variables: Starch, Soya bean meal, K2HPO4,
CaCO3 and FeSO4. The optimum condition was found to be: Starch
(8.9,g/L), Soya bean meal (3.3 g/L), K2HPO4 (0.8 g/L), CaCO3 (4
g/L) and FeSO4 (0.03 g/L). At these optimized conditions, the yield
of gentamicin was found to be 1020 mg/L. The R2 values were found
to be 1 for ANN training set, 0.9953 for ANN test set, and 0.9286 for
RSM.
Abstract: Eight steel reinforced concrete beams (SRC), were
fabricated and tested under earthquake type cyclic loading. The
effectiveness of intermediate stiffeners, such as mid-span stiffener and
plastic hinge zone stiffeners, in enhancing composite action and
ductility of SRC beams was investigated. The effectiveness of
strengthened beam-to-column (SBC) and weakened beam-to-column
(WBC) connections in enhancing beam ductility was also studied. It
was found that: (1) All the specimens possessed fairly high flexural
ductility and were found adequate for structures in high seismic zones.
(2) WBC connections induced stress concentration which caused extra
damage to concrete near the flange tapering zone. This extra damage
inhibited the flexural strength development and the ductility of the
specimens with WBC connections to some extent. (3) Specimens with
SBC connections demonstrated higher flexural strength and ductility
compared to specimens with WBC connections. (4) The intermediate
stiffeners, especially combination of plastic hinge zone stiffener and
mid span stiffeners, have an obvious effect in enhancing the ductility
of the beams with SBC connection.
Abstract: Detection and recognition of the Human Body Composition and extraction their measures (width and length of human body) in images are a major issue in detecting objects and the important field in Image, Signal and Vision Computing in recent years. Finding people and extraction their features in Images are particularly important problem of object recognition, because people can have high variability in the appearance. This variability may be due to the configuration of a person (e.g., standing vs. sitting vs. jogging), the pose (e.g. frontal vs. lateral view), clothing, and variations in illumination. In this study, first, Human Body is being recognized in image then the measures of Human Body extract from the image.
Abstract: Use of the Internet and the World-Wide-Web
(WWW) has become widespread in recent years and mobile agent
technology has proliferated at an equally rapid rate. In this scenario
load balancing becomes important for P2P systems. Beside P2P
systems can be highly heterogeneous, i.e., they may consists of peers
that range from old desktops to powerful servers connected to
internet through high-bandwidth lines. There are various loads
balancing policies came into picture. Primitive one is Message
Passing Interface (MPI). Its wide availability and portability make it
an attractive choice; however the communication requirements are
sometimes inefficient when implementing the primitives provided by
MPI. In this scenario we use the concept of mobile agent because
Mobile agent (MA) based approach have the merits of high
flexibility, efficiency, low network traffic, less communication
latency as well as highly asynchronous. In this study we present
decentralized load balancing scheme using mobile agent technology
in which when a node is overloaded, task migrates to less utilized
nodes so as to share the workload. However, the decision of which
nodes receive migrating task is made in real-time by defining certain
load balancing policies. These policies are executed on PMADE (A
Platform for Mobile Agent Distribution and Execution) in
decentralized manner using JuxtaNet and various load balancing
metrics are discussed.
Abstract: According to investigating impact of complexity of
stereoscopic frame pairs on stereoscopic video coding and
transmission, a new rate control algorithm is presented. The proposed
rate control algorithm is performed on three levels: stereoscopic group
of pictures (SGOP) level, stereoscopic frame (SFrame) level and
frame level. A temporal-spatial frame complexity model is firstly
established, in the bits allocation stage, the frame complexity, position
significance and reference property between the left and right frames
are taken into account. Meanwhile, the target buffer is set according to
the frame complexity. Experimental results show that the proposed
method can efficiently control the bitrates, and it outperforms the fixed
quantization parameter method from the rate distortion perspective,
and average PSNR gain between rate-distortion curves (BDPSNR) is
0.21dB.
Abstract: In this paper, we consider a risk model involving two independent classes of insurance risks and random premium income. We assume that the premium income process is a Poisson Process, and the claim number processes are independent Poisson and generalized Erlang(n) processes, respectively. Both of the Gerber- Shiu functions with zero initial surplus and the probability generating functions (p.g.f.) of the Gerber-Shiu functions are obtained.
Abstract: The efficacy of the separate mixing of four tropical spicy and medicinal plant products: Dennettia tripetala Baker (pepper fruit), Eugenia aromatica Hook (clove), Piper guineense (Schum and Thonn) (black pepper) and Monodora myristica (Dunal) (African nut-meg) with a household vegetable oil was evaluated under tropical storage conditions for the control and reproductive performance of Dermestes maculatus (De Geer) (hide beetle) and Necroba rufipes (De Geer) (copra beetle) on African catfish, Clarias gariepinus (Burchell). Each of the plant materials was pulverized into powder and applied as a mix of 1ml of oil and plant powder at 2.5, 5.0, 7.5 and 10.0g per 100g of dried fish, and allowed to dry for 6h. Each of the four oil-mixed powder treatments evoked significant (P < 05) mortalities of the two insects compared with the control (oil only) at 1, 3 and 7 days post treatment. The oil-powder mixture dosages did not prevent insect egg hatchability but while the emergent larvae on the treated samples died, the emergent larvae in the control survived into adults. The application of oil-mixed powders effectively suppressed the emergence of the larvae of the beetles. Similarly, each of the oil-powder mixtures significantly reduced weight loss in smoked fish that were exposed to D. maculatus and N. rufipes when compared to the control (P < 05). The results of this study suggest that the plant powders rather than the domestic oil demonstrated protective ability against the fish beetles and confirm the efficacy of the plant products as pest control agents.
Abstract: This paper deals with the analysis of active constrained layer damping (ACLD) of doubly curved laminated composite shells using active fiber composite (AFC) materials. The constraining layer of the ACLD treatment has been considered to be made of the AFC materials. A three dimensional energy based finite element model of the smart doubly curved laminated composite shell integrated with a patch of such ACLD treatment has been developed to demonstrate the performance of the patch on enhancing the damping characteristics of the doubly curved laminated composite shells. Particular emphasis has been placed on studying the effect of variation of piezoelectric fiber orientation angle in the constraining AFC layer on the control authority of the ACLD patch.
Abstract: Solar sunspot rotation, latitudinal bands are studied based on intelligent computation methods. A combination of image fusion method with together tree decomposition is used to obtain quantitative values about the latitudes of trajectories on sun surface that sunspots rotate around them. Daily solar images taken with SOlar and Heliospheric (SOHO) satellite are fused for each month separately .The result of fused image is decomposed with Quad Tree decomposition method in order to achieve the precise information about latitudes of sunspot trajectories. Such analysis is useful for gathering information about the regions on sun surface and coordinates in space that is more expose to solar geomagnetic storms, tremendous flares and hot plasma gases permeate interplanetary space and help human to serve their technical systems. Here sunspot images in September, November and October in 2001 are used for studying the magnetic behavior of sun.
Abstract: In this paper, we propose a fixed formatting method of PPX(Pretty Printer for XML). PPX is a query language for XML database which has extensive formatting capability that produces HTML as the result of a query. The fixed formatting method is to completely specify the combination of variables and layout specification operators within the layout expression of the GENERATE clause of PPX. In the experiment, a quick comparison shows that PPX requires far less description compared to XSLT or XQuery programs doing the same tasks.
Abstract: IEEE 802.15.4a impulse radio-time hopping ultra wide
band (IR-TH UWB) physical layer, due to small duty cycle and very
short pulse widths is robust against multipath propagation. However,
scattering and reflections with the large number of obstacles in indoor
channel environments, give rise to dense multipath fading. It imposes
serious problem to optimum Rake receiver architectures, for which
very large number of fingers are needed. Presence of strong noise
also affects the reception of fine pulses having extremely low power
spectral density. A robust SRake receiver for IEEE 802.15.4a IRTH
UWB in dense multipath and additive white Gaussian noise
(AWGN) is proposed to efficiently recover the weak signals with
much reduced complexity. It adaptively increases the signal to noise
(SNR) by decreasing noise through a recursive least square (RLS)
algorithm. For simulation, dense multipath environment of IEEE
802.15.4a industrial non line of sight (NLOS) is employed. The power
delay profile (PDF) and the cumulative distribution function (CDF)
for the respective channel environment are found. Moreover, the error
performance of the proposed architecture is evaluated in comparison
with conventional SRake and AWGN correlation receivers. The
simulation results indicate a substantial performance improvement
with very less number of Rake fingers.
Abstract: Online Communities are an example of sociallyaware,
self-organising, complex adaptive computing systems.
The multi-agent systems (MAS) paradigm coordinated by
self-organisation mechanisms has been used as an effective
way for the simulation and modeling of such systems. In this
paper, we propose a model for simulating an online health
community using a situated multi-agent system approach,
governed by the co-evolution of the social and spatial
organisations of the agents.
Abstract: This paper examines the modeling and analysis of a
cruise control system using a Petri net based approach, task graphs,
invariant analysis and behavioral properties. It shows how the
structures used can be verified and optimized.