Abstract: In this paper the reference current for Voltage Source
Converter (VSC) of the Shunt Active Power Filter (SAPF) is
generated using Synchronous Reference Frame method,
incorporating the PI controller with anti-windup scheme. The
proposed method improves the harmonic filtering by compensating
the winding up phenomenon caused by the integral term of the PI
controller.
Using Reference Frame Transformation, the current is transformed
from om a - b - c stationery frame to rotating 0 - d - q frame. Using
the PI controller, the current in the 0 - d - q frame is controlled to
get the desired reference signal. A controller with integral action
combined with an actuator that becomes saturated can give some
undesirable effects. If the control error is so large that the integrator
saturates the actuator, the feedback path becomes ineffective because
the actuator will remain saturated even if the process output changes.
The integrator being an unstable system may then integrate to a very
large value, the phenomenon known as integrator windup.
Implementing the integrator anti-windup circuit turns off the
integrator action when the actuator saturates, hence improving the
performance of the SAPF and dynamically compensating harmonics
in the power network. In this paper the system performance is
examined with Shunt Active Power Filter simulation model.
Abstract: In this paper bi-annual time series data on unemployment rates (from the Labour Force Survey) are expanded to quarterly rates and linked to quarterly unemployment rates (from the Quarterly Labour Force Survey). The resultant linked series and the consumer price index (CPI) series are examined using Johansen’s cointegration approach and vector error correction modeling. The study finds that both the series are integrated of order one and are cointegrated. A statistically significant co-integrating relationship is found to exist between the time series of unemployment rates and the CPI. Given this significant relationship, the study models this relationship using Vector Error Correction Models (VECM), one with a restriction on the deterministic term and the other with no restriction.
A formal statistical confirmation of the existence of a unique linear and lagged relationship between inflation and unemployment for the period between September 2000 and June 2011 is presented. For the given period, the CPI was found to be an unbiased predictor of the unemployment rate. This relationship can be explored further for the development of appropriate forecasting models incorporating other study variables.
Abstract: Phishing, or stealing of sensitive information on the
web, has dealt a major blow to Internet Security in recent times. Most
of the existing anti-phishing solutions fail to handle the fuzziness
involved in phish detection, thus leading to a large number of false
positives. This fuzziness is attributed to the use of highly flexible and
at the same time, highly ambiguous HTML language. We introduce a
new perspective against phishing, that tries to systematically prove,
whether a given page is phished or not, using the corresponding
original page as the basis of the comparison. It analyzes the layout of
the pages under consideration to determine the percentage distortion
between them, indicative of any form of malicious alteration. The
system design represents an intelligent system, employing dynamic
assessment which accurately identifies brand new phishing attacks
and will prove effective in reducing the number of false positives.
This framework could potentially be used as a knowledge base, in
educating the internet users against phishing.
Abstract: In cellular networks, limited availability of resources
has to be tapped to its fullest potential. In view of this aspect, a
sophisticated averaging and voting technique has been discussed in
this paper, wherein the radio resources available are utilized to the
fullest value by taking into consideration, several network and radio
parameters which decide on when the handover has to be made and
thereby reducing the load on Base station .The increase in the load
on the Base station might be due to several unnecessary handover
taking place which can be eliminated by making judicious use of the
radio and network parameters.
Abstract: The term private equity usually refers to any type of
equity investment in an asset in which the equity is not freely
tradable on a public stock market. Some researchers believe that
private equity contributed to the extent of the crisis and increased
the pace of its spread over the world. We do not agree with this.
On the other hand, we argue that during the economic recession
private equity might become an important source of funds for firms
with special needs (e.g. for firms seeking buyout financing, venture
capital, expansion capital or distress debt financing). However,
over-regulation of private equity in both the European Union and
the US can slow down this specific funding channel to the
economy and deepen credit crunch during global crises.
Abstract: The purpose of this study is to present a non invasive
method for the marginal adaptation evaluation in class V composite
restorations. Standardized class V cavities, prepared in human
extracted teeth, were filled with Premise (Kerr) composite. The
specimens were thermo cycled. The interfaces were examined by
Optical Coherence Tomography method (OCT) combined with the
confocal microscopy and fluorescence. The optical configuration
uses two single mode directional couplers with a superluminiscent
diode as the source at 1300 nm. The scanning procedure is similar to
that used in any confocal microscope, where the fast scanning is enface
(line rate) and the depth scanning is much slower (at the frame
rate). Gaps at the interfaces as well as inside the composite resin
materials were identified. OCT has numerous advantages which
justify its use in vivo as well as in vitro in comparison with
conventional techniques.
Abstract: Corporate credit rating prediction using statistical and
artificial intelligence (AI) techniques has been one of the attractive
research topics in the literature. In recent years, multiclass
classification models such as artificial neural network (ANN) or
multiclass support vector machine (MSVM) have become a very
appealing machine learning approaches due to their good
performance. However, most of them have only focused on classifying
samples into nominal categories, thus the unique characteristic of the
credit rating - ordinality - has been seldom considered in their
approaches. This study proposes new types of ANN and MSVM
classifiers, which are named OMANN and OMSVM respectively.
OMANN and OMSVM are designed to extend binary ANN or SVM
classifiers by applying ordinal pairwise partitioning (OPP) strategy.
These models can handle ordinal multiple classes efficiently and
effectively. To validate the usefulness of these two models, we applied
them to the real-world bond rating case. We compared the results of
our models to those of conventional approaches. The experimental
results showed that our proposed models improve classification
accuracy in comparison to typical multiclass classification techniques
with the reduced computation resource.
Abstract: In this paper, a new approach based on the extent of
friendship between the nodes is proposed which makes the nodes to
co-operate in an ad hoc environment. The extended DSR protocol is
tested under different scenarios by varying the number of malicious
nodes and node moving speed. It is also tested varying the number of
nodes in simulation used. The result indicates the achieved
throughput by extended DSR is greater than the standard DSR and
indicates the percentage of malicious drops over total drops are less
in the case of extended DSR than the standard DSR.
Abstract: Speedups from mapping four real-life DSP
applications on an embedded system-on-chip that couples coarsegrained
reconfigurable logic with an instruction-set processor are
presented. The reconfigurable logic is realized by a 2-Dimensional
Array of Processing Elements. A design flow for improving
application-s performance is proposed. Critical software parts, called
kernels, are accelerated on the Coarse-Grained Reconfigurable
Array. The kernels are detected by profiling the source code. For
mapping the detected kernels on the reconfigurable logic a prioritybased
mapping algorithm has been developed. Two 4x4 array
architectures, which differ in their interconnection structure among
the Processing Elements, are considered. The experiments for eight
different instances of a generic system show that important overall
application speedups have been reported for the four applications.
The performance improvements range from 1.86 to 3.67, with an
average value of 2.53, compared with an all-software execution.
These speedups are quite close to the maximum theoretical speedups
imposed by Amdahl-s law.
Abstract: Non-saturated soils that while saturation greatly
decrease their volume, have sudden settlement due to increasing
humidity, fracture and structural crack are called loess soils. Whereas
importance of civil projects including: dams, canals and
constructions bearing this type of soil and thereof problems, it is
required for carrying out more research and study in relation to loess
soils. This research studies shear strength parameters by using
grading test, Atterberg limit, compression, direct shear and
consolidation and then effect of using cement and lime additives on
stability of loess soils is studied. In related tests, lime and cement are
separately added to mixed ratios under different percentages of soil
and for different times the stabilized samples are processed and effect
of aforesaid additives on shear strength parameters of soil is studied.
Results show that upon passing time the effect of additives and
collapsible potential is greatly decreased and upon increasing
percentage of cement and lime the maximum dry density is
decreased; however, optimum humidity is increased. In addition,
liquid limit and plastic index is decreased; however, plastic index
limit is increased. It is to be noted that results of direct shear test
reveal increasing shear strength of soil due to increasing cohesion
parameter and soil friction angle.
Abstract: the aim of this study was to analyze ethnopsychological content of “Aitys" as a process of creative competition in Kazakh traditional folklore by means of Transaction analysis (three types of Ego states are Parent, Adult and Child). “Aitys" is as sources of Kazakh national self-consciousness and form of oral Kazakh national creativity. Comparative psychological analysis of classical and modern “aityses" is carried out. Empirical proved that the victory in “Aitys" is provided with a position of egostate “Adult".
Abstract: The paper presents the potential of fuzzy logic (FL-I)
and neural network techniques (ANN-I) for predicting the
compressive strength, for SCC mixtures. Six input parameters that is
contents of cement, sand, coarse aggregate, fly ash, superplasticizer
percentage and water-to-binder ratio and an output parameter i.e. 28-
day compressive strength for ANN-I and FL-I are used for modeling.
The fuzzy logic model showed better performance than neural
network model.
Abstract: Power cables are vulnerable to failure due to aging or
defects that occur with the passage of time under continuous
operation and loading stresses. PD detection and characterization
provide information on the location, nature, form and extent of the
degradation. As a result, PD monitoring has become an important
part of condition based maintenance (CBM) program among power
utilities. Online partial discharge (PD) localization of defect sources
in power cable system is possible using the time of flight method.
The information regarding the time difference between the main and
reflected pulses and cable length can help in locating the partial
discharge source along the cable length. However, if the length of
the cable is not known and the defect source is located at the extreme
ends of the cable or in the middle of the cable, then double ended
measurement is required to indicate the location of PD source. Use of
multiple sensors can also help in discriminating the cable PD or local/
external PD. This paper presents the experience and results from
online partial discharge measurements conducted in the laboratory
and the challenges in partial discharge source localization.
Abstract: Chicken fat was employed as a feedstock for
producing of biodiesel by trasesterification reaction with methanol
and alkali catalyst (KOH). In this study chicken fat biodiesel with
1.4% free fatty acid, methanol and various amount of potassium
hydroxide for 2 hour were studied. The progression of reaction and
conversion of triglycerides to methyl ester were checked by IR
spectrum method.
Abstract: In the recent years multimedia traffic and in particular
VoIP services are growing dramatically. We present a new algorithm
to control the resource utilization and to optimize the voice codec
selection during SIP call setup on behalf of the traffic condition
estimated on the network path.
The most suitable methodologies and the tools that perform realtime
evaluation of the available bandwidth on a network path have
been integrated with our proposed algorithm: this selects the best
codec for a VoIP call in function of the instantaneous available
bandwidth on the path. The algorithm does not require any explicit
feedback from the network, and this makes it easily deployable over
the Internet. We have also performed intensive tests on real network
scenarios with a software prototype, verifying the algorithm
efficiency with different network topologies and traffic patterns
between two SIP PBXs.
The promising results obtained during the experimental validation
of the algorithm are now the basis for the extension towards a larger
set of multimedia services and the integration of our methodology
with existing PBX appliances.
Abstract: Since the 80s huge efforts have been made to utilize
renewable energy sources to generate electric power. This paper
reports some aspects of integration of the distributed generators into
the low voltage distribution networks. An assessment of impact of the
distributed generators on the reliability indices of low voltage
network is performed. Results obtained from case study using low
voltage network, are presented and discussed.
Abstract: An innovative tri-axes micro-power receiver is
proposed. The tri-axes micro-power receiver consists of two sets 3-D
micro-solenoids and one set planar micro-coils in which iron core is
embedded. The three sets of micro-coils are designed to be orthogonal
to each other. Therefore, no matter which direction the flux is present
along, the magnetic energy can be harvested and transformed into
electric power. Not only dead space of receiving power is mostly
reduced, but also transformation efficiency of electromagnetic energy
to electric power can be efficiently raised. By employing commercial
software, Ansoft Maxwell, the preliminary simulation results verify
that the proposed micro-power receiver can efficiently pick up the
energy transmitted by magnetic power source.
As to the fabrication process, the isotropic etching technique is
employed to micro-machine the inverse-trapezoid fillister so that the
copper wire can be successfully electroplated. The adhesion between
micro-coils and fillister is much enhanced.
Abstract: Most of the image watermarking methods, using the properties of the human visual system (HVS), have been proposed in literature. The component of the visual threshold is usually related to either the spatial contrast sensitivity function (CSF) or the visual masking. Especially on the contrast masking, most methods have not mention to the effect near to the edge region. Since the HVS is sensitive what happens on the edge area. This paper proposes ultrasound image watermarking using the visual threshold corresponding to the HVS in which the coefficients in a DCT-block have been classified based on the texture, edge, and plain area. This classification method enables not only useful for imperceptibility when the watermark is insert into an image but also achievable a robustness of watermark detection. A comparison of the proposed method with other methods has been carried out which shown that the proposed method robusts to blockwise memoryless manipulations, and also robust against noise addition.
Abstract: In first stage of each microwave receiver there is Low
Noise Amplifier (LNA) circuit, and this stage has important rule in
quality factor of the receiver. The design of a LNA in Radio
Frequency (RF) circuit requires the trade-off many importance
characteristics such as gain, Noise Figure (NF), stability, power
consumption and complexity. This situation Forces desingners to
make choices in the desing of RF circuits. In this paper the aim is to
design and simulate a single stage LNA circuit with high gain and
low noise using MESFET for frequency range of 5 GHz to 6 GHz.
The desing simulation process is down using Advance Design
System (ADS). A single stage LNA has successfully designed with
15.83 dB forward gain and 1.26 dB noise figure in frequency of 5.3
GHz. Also the designed LNA should be working stably In a
frequency range of 5 GHz to 6 GHz.
Abstract: Seaweed farming is emerging as a viable alternative
activity in the Indonesian fisheries sector. This paper aims to
investigate people-s perceptions of seaweed farming, to analyze its
social and economic impacts and to identify the problems and
obstacles hindering its continued development. Structured and
semi-structured questionnaires were prepared to obtain qualitative
data, and interviews were conducted with fishermen who also plant
seaweed. The findings showed that fishermen in the Laikang Bay were
enthusiastic about cultivating seaweeds and that seaweed plays a major
role in supporting the household economy of fishermen. However,
current seaweed drying technologies cannot support increased
seaweed production on a farm or plot, especially in the rainy season.
Additionally, variable monsoon seasons and long marketing channels
are still major constraints on the development of the industry. Finally,
capture fisheries, the primary economic livelihood of fishermen of
older generations, is being slowly replaced by seaweed farming.