Abstract: Vector quantization is a powerful tool for speech
coding applications. This paper deals with LPC Coding of speech
signals which uses a new technique called Multi Switched Split
Vector Quantization, This is a hybrid of two product code vector
quantization techniques namely the Multi stage vector quantization
technique, and Switched split vector quantization technique,. Multi
Switched Split Vector Quantization technique quantizes the linear
predictive coefficients in terms of line spectral frequencies. From
results it is proved that Multi Switched Split Vector Quantization
provides better trade off between bitrate and spectral distortion
performance, computational complexity and memory requirements
when compared to Switched Split Vector Quantization, Multi stage
vector quantization, and Split Vector Quantization techniques. By
employing the switching technique at each stage of the vector
quantizer the spectral distortion, computational complexity and
memory requirements were greatly reduced. Spectral distortion was
measured in dB, Computational complexity was measured in
floating point operations (flops), and memory requirements was
measured in (floats).
Abstract: The aim of this study is to examine the reading
comprehension scores of Turkish 5th grade students according to the
variables given in the student questionnaire. In this descriptive
survey study research participated 279 5th grade students, who
studied at 10 different primary schools in four provinces of Ankara in
2008-2009 academic year. Two different data collection tools were
made use of in the study: “Reading Comprehension Test" and
“Student Information Questionnaire". Independent sample t-test, oneway
Anova and two-way Anova tests were used in the analyses of
the gathered data. The results of the study indicate that the reading
comprehension scores of the students differ significantly according to
sex of the students, the number of books in their houses, the
frequency of summarizing activities on the reading text of free and
the frequency reading hours provided by their teachers; but, differ
not significantly according to educational level of their mothers and
fathers.
Abstract: Dynamics of a vapour bubble generated due to a high local energy input near a circular thin bronze plate in the absence of the buoyancy forces is numerically investigated in this paper. The bubble is generated near a thin bronze plate and during the growth and collapse of the bubble, it deforms the nearby plate. The Boundary Integral Equation Method is employed for numerical simulation of the problem. The fluid is assumed to be incompressible, irrotational and inviscid and the surface tension on the bubble boundary is neglected. Therefore the fluid flow around the vapour bubble can be assumed as a potential flow. Furthermore, the thin bronze plate is assumed to have perfectly plastic behaviour. Results show that the displacement of the circular thin bronze plate has considerable effect on the dynamics of its nearby vapour bubble. It is found that by decreasing the thickness of the thin bronze plate, the growth and collapse rate of the bubble becomes higher and consequently the lifetime of the bubble becomes shorter.
Abstract: This paper is a part of research, in which the way the
biomedical engineers follow in their work is analyzed. The goal of
this paper is to present a method for specification of user
requirements in the medical devices maintenance process. Data
Gathering Methods, Research Model Phases and Descriptive
Analysis is presented. These technology and verification rules can be
implemented in Medical devices maintenance management process to
the maintenance process.
Abstract: This paper presents the effect of driving a motor
vehicle on the stress levels of older drivers, indicated by monitoring
their hear rate increase whilst completing various everyday driving
tasks. Results suggest that whilst older female drivers heart rate varied
more significantly than males, the actual age of a participant did not
result in a significant change in heart rate due to stress, within the age
group tested. The analysis of the results indicates the most stressful
manoeuvres undertaken by the older drivers and highlights the tasks
which were found difficult with a view to implementing technologies
to aid the more senior driver in automotive travel.
Abstract: We theoretically investigate the effects of frequency
detuning and injection power on the nonlinear dynamics of DFB
lasers under dual external optical injection.
Abstract: The importance of good requirements engineering is well documented. Agile practices, promoting collaboration and communications, facilitate the elicitation and management of volatile requirements. However, current Agile practices work in a well-defined environment. It is necessary to have a co-located customer. With distributed development it is not always possible to realize this co-location. In this environment a suitable process, possibly supported by tools, is required to support changing requirements. This paper introduces the issues of concern when managing requirements in a distributed environment and describes work done at the Software Technology Research Centre as part of the NOMAD project.
Abstract: In this paper, penalized power-divergence test statistics have been defined and their exact size properties to test a nested sequence of log-linear models have been compared with ordinary power-divergence test statistics for various penalization, λ and main effect values. Since the ordinary and penalized power-divergence test statistics have the same asymptotic distribution, comparisons have been only made for small and moderate samples. Three-way contingency tables distributed according to a multinomial distribution have been considered. Simulation results reveal that penalized power-divergence test statistics perform much better than their ordinary counterparts.
Abstract: A passive system "Qanat" is collection of some
underground wells. A mother-well was dug in a place far from the
city where they could reach to the water table maybe 100 meters
underground, they dug other wells to direct water toward the city,
with minimum possible gradient. Using the slope of the earth they
could bring water close to the surface in the city. The source of water
or the appearance of Qanat, land slope and the ownership lines are
the important and effective factors in the formation of routes and the
segment division of lands to the extent that making use of Qanat as
the techniques of extracting underground waters creates a channel of
routes with an organic order and hierarchy coinciding the slope of
land and it also guides the Qanat waters in the tradition texture of salt
desert and border provinces of it. Qanats are excavated in a specified
distinction from each other. The quantity of water provided by
Qanats depends on the kind of land, distance from mountain,
geographical situation of them and the rate of water supply from the
underground land. The rate of underground waters, possibility of
Qanat excavation, number of Qanats and rate of their water supply
from one hand and the quantity of cultivable fertile lands from the
other hand are the important natural factors making the size of cities.
In the same manner the cities with several Qanats have multi central
textures. The location of cities is in direct relation with land quality,
soil fertility and possibility of using underground water by excavating
Qanats. Observing the allowable distance for Qanat watering is a
determining factor for distance between villages and cities.
Topography, land slope, soil quality, watering system, ownership,
kind of cultivation, etc. are the effective factors in directing Qanats
for excavation and guiding water toward the cultivable lands and it
also causes the formation of different textures in land division of
farming provinces. Several divisions such as orderly and wide, inorderly,
thin and long, comb like, etc. are the introduction to organic
order. And at the same time they are complete coincidence with
environmental conditions in the typical development of ecological
architecture and planning in the traditional cities and settlements
order.
Abstract: In this research, we study a control method of a multivehicle
system while considering the limitation of communication
range for each vehicles. When we control networked vehicles with
limitation of communication range, it is important to control the
communication network structure of a multi-vehicle system in order
to keep the network-s connectivity. From this, we especially aim to
control the network structure to the target structure. We formulate
the networked multi-vehicle system with some disturbance and the
communication constraints as a hybrid dynamical system, and then
we study the optimal control problems of the system. It is shown
that the system converge to the objective network structure in finite
time when the system is controlled by the receding horizon method.
Additionally, the optimal control probrems are convertible into the
mixed integer problems and these problems are solvable by some
branch and bound algorithm.
Abstract: Recent developments in Soft computing techniques,
power electronic switches and low-cost computational hardware have
made it possible to design and implement sophisticated control
strategies for sensorless speed control of AC motor drives. Such an
attempt has been made in this work, for Sensorless Speed Control of
Induction Motor (IM) by means of Direct Torque Fuzzy Control
(DTFC), PI-type fuzzy speed regulator and MRAS speed estimator
strategy, which is absolutely nonlinear in its nature. Direct torque
control is known to produce quick and robust response in AC drive
system. However, during steady state, torque, flux and current ripple
occurs. So, the performance of conventional DTC with PI speed
regulator can be improved by implementing fuzzy logic techniques.
Certain important issues in design including the space vector
modulated (SVM) 3-Ф voltage source inverter, DTFC design,
generation of reference torque using PI-type fuzzy speed regulator
and sensor less speed estimator have been resolved. The proposed
scheme is validated through extensive numerical simulations on
MATLAB. The simulated results indicate the sensor less speed
control of IM with DTFC and PI-type fuzzy speed regulator provides
satisfactory high dynamic and static performance compare to
conventional DTC with PI speed regulator.
Abstract: Agricultural residue such as oil palm fronds (OPF) is
cheap, widespread and available throughout the year. Hemicelluloses
extracted from OPF can be hydrolyzed to their monomers and used in
production of xylooligosaccharides (XOs). The objective of the
present study was to optimize the enzymatic hydrolysis process of
OPF hemicellulose by varying pH, temperature, enzyme and substrate
concentration for production of XOs. Hemicelluloses was extracted
from OPF by using 3 M potassium hydroxide (KOH) at temperature of
40°C for 4 hrs and stirred at 400 rpm. The hemicellulose was then
hydrolyzed using Trichoderma longibrachiatum xylanase at different
pH, temperature, enzyme and substrate concentration. XOs were
characterized based on reducing sugar determination. The optimum
conditions to produced XOs from OPF hemicellulose was obtained at
pH 4.6, temperature of 40°C , enzyme concentration of 2 U/mL and
2% substrate concentration. The results established the suitability of
oil palm fronds as raw material for production of XOs.
Abstract: The purpose of this study is to discuss the effect of the
intervention of exercise behavior change plan for high school students
on study subjects- social and psychological factors and exercise
stages. This research uses the transtheoretical model as the research
framework. One experiment group and one control group were used in
a quasi-experimental design research. The experimental group
accepted health-related physical fitness course and the traditional
course; the control group accepted traditional physical education
course. There is a significant difference before and after the
intervention in the experimental group. Karl-s test shows the
experimental group gained a better improvement than that in the
control group. The Analysis of Covariance had shown the exercise
stages (F=7.62, p
Abstract: Sensor networks are often deployed in unattended
environments, thus leaving these networks vulnerable to false data
injection attacks in which an adversary injects forged reports into the
network through compromised nodes, with the goal of deceiving the
base station or depleting the resources of forwarding nodes. Several
research solutions have been recently proposed to detect and drop such
forged reports during the forwarding process. Each design can provide
the equivalent resilience in terms of node compromising. However,
their energy consumption characteristics differ from each other. Thus,
employing only a single filtering scheme for a network is not a
recommendable strategy in terms of energy saving. It's very important
the threshold determination for message authentication to identify. We
propose the recursive contract net protocols which less energy level of
terminal node in wireless sensor network.
Abstract: Using Dynamic Bayesian Networks (DBN) to model genetic regulatory networks from gene expression data is one of the major paradigms for inferring the interactions among genes. Averaging a collection of models for predicting network is desired, rather than relying on a single high scoring model. In this paper, two kinds of model searching approaches are compared, which are Greedy hill-climbing Search with Restarts (GSR) and Markov Chain Monte Carlo (MCMC) methods. The GSR is preferred in many papers, but there is no such comparison study about which one is better for DBN models. Different types of experiments have been carried out to try to give a benchmark test to these approaches. Our experimental results demonstrated that on average the MCMC methods outperform the GSR in accuracy of predicted network, and having the comparable performance in time efficiency. By proposing the different variations of MCMC and employing simulated annealing strategy, the MCMC methods become more efficient and stable. Apart from comparisons between these approaches, another objective of this study is to investigate the feasibility of using DBN modeling approaches for inferring gene networks from few snapshots of high dimensional gene profiles. Through synthetic data experiments as well as systematic data experiments, the experimental results revealed how the performances of these approaches can be influenced as the target gene network varies in the network size, data size, as well as system complexity.
Abstract: In rail vehicles, air springs are very important isolating component, which guarantee good ride comfort for passengers during their trip. In the most new rail–vehicle models, developed by researchers, the thermo–dynamical effects of air springs are ignored and secondary suspension is modeled by simple springs and dampers. As the performance of suspension components have significant effects on rail–vehicle dynamics and ride comfort of passengers, a complete nonlinear thermo–dynamical air spring model, which is a combination of two different models, is introduced. Result from field test shows remarkable agreement between proposed model and experimental data. Effects of air suspension parameters on the system performances are investigated here and then these parameters are tuned to minimize Sperling ride comfort index during the trip. Results showed that by modification of air suspension parameters, passengers comfort is improved and ride comfort index is reduced about 10%.
Abstract: All over the world, including the Middle and East
European countries, sustainable tillage and sowing technologies are
applied increasingly broadly with a view to optimising soil resources,
mitigating soil degradation processes, saving energy resources,
preserving biological diversity, etc. As a result, altered conditions of
tillage and sowing technological processes are faced inevitably. The
purpose of this study is to determine the seedbed topsoil hardness
when using a combined sowing coulter in different sustainable tillage
technologies. The research involved a combined coulter consisting
of two dissected blade discs and a shoe coulter. In order to determine
soil hardness at the seedbed area, a multipenetrometer was used. It
was found by experimental studies that in loosened soil, a combined
sowing coulter equally suppresses the furrow bottom, walls and soil
near the furrow; therefore, here, soil hardness was similar at all
researched depths and no significant differences were established. In
loosened and compacted (double-rolled) soil, the impact of a
combined coulter on the hardness of seedbed soil surface was more
considerable at a depth of 2 mm. Soil hardness at the furrow bottom
and walls to a distance of up to 26 mm was 1.1 MPa. At a depth of 10
mm, the greatest hardness was established at the furrow bottom. In
loosened and heavily compacted (rolled for 6 times) soil, at a depth
of 2 and 10 mm a combined coulter most of all compacted the furrow
bottom, which has a hardness of 1.8 MPa. At a depth of 20 mm, soil
hardness within the whole investigated area varied insignificantly and
fluctuated by around 2.0 MPa. The hardness of furrow walls and soil
near the furrow was by approximately 1.0 MPa lower than that at the
furrow bottom
Abstract: This article presents the developments of efficient
algorithms for tablet copies comparison. Image recognition has
specialized use in digital systems such as medical imaging,
computer vision, defense, communication etc. Comparison between
two images that look indistinguishable is a formidable task. Two
images taken from different sources might look identical but due to
different digitizing properties they are not. Whereas small variation
in image information such as cropping, rotation, and slight
photometric alteration are unsuitable for based matching
techniques. In this paper we introduce different matching
algorithms designed to facilitate, for art centers, identifying real
painting images from fake ones. Different vision algorithms for
local image features are implemented using MATLAB. In this
framework a Table Comparison Computer Tool “TCCT" is
designed to facilitate our research. The TCCT is a Graphical Unit
Interface (GUI) tool used to identify images by its shapes and
objects. Parameter of vision system is fully accessible to user
through this graphical unit interface. And then for matching, it
applies different description technique that can identify exact
figures of objects.
Abstract: Potato is one of the main components of warm meals in Latvia. Consumption of fried potatoes in Latvia is the highest comparing to Nordic and other Baltic countries. Therefore acrylamide (AA) intake coming from fried potatoes in population might be high as well. The aim of the research was to determine AA content in traditionally cooked potatoes bred and cultivated in Latvia. Five common Latvian potato varieties were selected: Lenora, Brasla, Imanta, Zile and Madara. A two-year research was conducted during two periods: just after harvesting and after six months of storage. The following cooking methods were used: shallow frying (150 ± 5 °C); deep-fat frying (180 ± 5 °C) and roasting (210 ± 5 °C). Time and temperature was recorded during frying. AA was extracted from potatoes by solid phase extraction and AA content was determined by LC-MS/MS. AA content significantly differs (p
Abstract: Stream Control Transmission Protocol (SCTP) has been
proposed to provide reliable transport of real-time communications.
Due to its attractive features, such as multi-streaming and multihoming,
the SCTP is often expected to be an alternative protocol
for TCP and UDP. In the original SCTP standard, the secondary path
is mainly regarded as a redundancy. Recently, most of researches
have focused on extending the SCTP to enable a host to send its
packets to a destination over multiple paths simultaneously. In order
to transfer packets concurrently over the multiple paths, the SCTP
should be well designed to avoid unnecessary fast retransmission
and the mis-estimation of congestion window size through the paths.
Therefore, we propose an Enhanced Cooperative ACK SCTP (ECASCTP)
to improve the path recovery efficiency of multi-homed host
which is under concurrent multiple transfer mode. We evaluated the
performance of our proposed scheme using ns-2 simulation in terms
of cwnd variation, path recovery time, and goodput. Our scheme
provides better performance in lossy and path asymmetric networks.