Abstract: This paper deals with the synthesis of fuzzy controller
applied to a permanent magnet synchronous machine (PMSM) with a
guaranteed H∞ performance. To design this fuzzy controller,
nonlinear model of the PMSM is approximated by Takagi-Sugeno
fuzzy model (T-S fuzzy model), then the so-called parallel
distributed compensation (PDC) is employed. Next, we derive the
property of the H∞ norm. The latter is cast in terms of linear matrix
inequalities (LMI-s) while minimizing the H∞ norm of the transfer
function between the disturbance and the error ( ) ev T . The
experimental and simulations results were conducted on a permanent
magnet synchronous machine to illustrate the effects of the fuzzy
modelling and the controller design via the PDC.
Abstract: A rigorous two-dimensional model is developed for simulating the operation of a less-investigated type steam reformer having a considerably lower operating Reynolds number, higher tube diameter, and non-availability of extra steam in the feed compared with conventional steam reformers. Simulation results show that reasonable predictions can only be achieved when certain correlations for wall to fluid heat transfer equations are applied. Due to severe operating conditions, in all cases, strong radial temperature gradients inside the reformer tubes have been found. Furthermore, the results show how a certain catalyst loading profile will affect the operation of the reformer.
Abstract: The market transformation in Kazakhstan during the
last two decades has essentially strengthened a gap between
development of urban and rural areas. Implementation of market
institutes, transition from public financing to paid rendering of social
services, change of forms of financing of social and economic
infrastructure have led to strengthening of an economic inequality of
social groups, including growth of stratification of the city and the
village. Sociological survey of urban and rural households in Almaty
city and villages of Almaty region has been carried out within the
international research project “Livelihoods Strategies of Private
Households in Central Asia: A Rural–Urban Comparison in
Kazakhstan and Kyrgyzstan" (Germany, Kazakhstan, Kyrgyzstan).
The analysis of statistical data and results of sociological research of
urban and rural households allows us to reveal issues of territorial
development, to investigate an availability of medical, educational
and other services in the city and the village, to reveal an evaluation
urban and rural dwellers of living conditions, to compare economic
strategies of households in the city and the village.
Abstract: This paper presents the H-ARQ techniques comparison for OFDM systems with a new family of non-binary LDPC codes which has been developed within the EU FP7 DAVINCI project. The punctured NB-LDPC codes have been used in a simulated model of the transmission system. The link level performance has been evaluated in terms of spectral efficiency, codeword error rate and average number of retransmissions. The NB-LDPC codes can be easily and effective implemented with different methods of the retransmission needed if correct decoding of a codeword failed. Here the Optimal Symbol Selection method is proposed as a Chase Combining technique.
Abstract: The special constraints of sensor networks impose a
number of technical challenges for employing them. In this review,
we study the issues and existing protocols in three areas: coverage
and routing. We present two types of coverage problems: to
determine the minimum number of sensor nodes that need to perform
active sensing in order to monitor a certain area; and to decide the
quality of service that can be provided by a given sensor network.
While most routing protocols in sensor networks are data-centric,
there are other types of routing protocols as well, such as
hierarchical, location-based, and QoS-aware. We describe and
compare several protocols in each group. We present several multipath
routing protocols and single-path with local repair routing
protocols, which are proposed for recovering from sensor node
crashes. We also discuss some transport layer schemes for reliable
data transmission in lossy wireless channels.
Abstract: Anaerobic Digestion has become a promising
technology for biological transformation of organic fraction of the
municipal solid wastes (MSW). In order to represent the kinetic
behavior of such biological process and thereby to design a reactor
system, development of a mathematical model is essential.
Addressing this issue, a simplistic mathematical model has been
developed for anaerobic digestion of MSW in a continuous flow
reactor unit under homogeneous steady state condition. Upon
simulated hydrolysis, the kinetics of biomass growth and substrate
utilization rate are assumed to follow first order reaction kinetics.
Simulation of this model has been conducted by studying sensitivity
of various process variables. The model was simulated using typical
kinetic data of anaerobic digestion MSW and typical MSW
characteristics of Kolkata. The hydraulic retention time (HRT) and
solid retention time (SRT) time were mainly estimated by varying
different model parameters like efficiency of reactor, influent
substrate concentration and biomass concentration. Consequently,
design table and charts have also been prepared for ready use in the
actual plant operation.
Abstract: Study of soil properties like field capacity (F.C.) and permanent wilting point (P.W.P.) play important roles in study of soil moisture retention curve. Although these parameters can be measured directly, their measurement is difficult and expensive. Pedotransfer functions (PTFs) provide an alternative by estimating soil parameters from more readily available soil data. In this investigation, 70 soil samples were collected from different horizons of 15 soil profiles located in the Ziaran region, Qazvin province, Iran. The data set was divided into two subsets for calibration (80%) and testing (20%) of the models and their normality were tested by Kolmogorov-Smirnov method. Both multivariate regression and artificial neural network (ANN) techniques were employed to develop the appropriate PTFs for predicting soil parameters using easily measurable characteristics of clay, silt, O.C, S.P, B.D and CaCO3. The performance of the multivariate regression and ANN models was evaluated using an independent test data set. In order to evaluate the models, root mean square error (RMSE) and R2 were used. The comparison of RSME for two mentioned models showed that the ANN model gives better estimates of F.C and P.W.P than the multivariate regression model. The value of RMSE and R2 derived by ANN model for F.C and P.W.P were (2.35, 0.77) and (2.83, 0.72), respectively. The corresponding values for multivariate regression model were (4.46, 0.68) and (5.21, 0.64), respectively. Results showed that ANN with five neurons in hidden layer had better performance in predicting soil properties than multivariate regression.
Abstract: In this paper, the Tabu search algorithm is used to
solve a transportation problem which consists of determining the
shortest routes with the appropriate vehicle capacity to facilitate the
travel of the students attending the University of Mauritius. The aim
of this work is to minimize the total cost of the distance travelled by
the vehicles in serving all the customers. An initial solution is
obtained by the TOUR algorithm which basically constructs a giant
tour containing all the customers and partitions it in an optimal way
so as to produce a set of feasible routes. The Tabu search algorithm
then makes use of a search procedure, a swapping procedure and the
intensification and diversification mechanism to find the best set of
feasible routes.
Abstract: In this study, we report the synthesis and
characterization of nanohydroxyapatite (nHAp) in gelatin-starch
matrix via biomimetic method. Characterization of the samples was
performed using X-ray diffraction (XRD) and Fourier Transform
infrared spectroscopy (FT-IR). The Size and morphology of the
nHAp samples were determined using scanning and transmission
electron microscopy (SEM and TEM). The results reveal that the
shape and morphology of nHAp is influenced by presence of
biopolymers as template. Carbonyl and amino groups from gelatin
and hydroxyl from starch play crucial roles in HAp formation on the
surface of gelatin-starch.
Abstract: There are few studies on eggshell of leatherback turtle
which is endangered species in Thailand. This study was focusing on
the ultrastructure and elemental composition of leatherback turtle
eggshells collected from Andaman Sea Shore, Thailand during the
nesting season using scanning electron microscope (SEM). Three
eggshell layers of leatherback turtle; the outer cuticle layer or
calcareous layer, the middle layer or middle multistrata layer and the
inner fibrous layer were recognized. The outer calcareous layer was
thick and porosity which consisted of loose nodular units of various
crystal shapes and sizes. The loose attachment between these units
resulted in numerous spaces and openings. The middle layer was
compact thick with several multistrata and contained numerous
openings connecting to both outer cuticle layer and inner fibrous
layer. The inner fibrous layer was compact and thin, and composed of
numerous reticular fibers. Energy dispersive X-ray microanalysis
detector revealed energy spectrum of X-rays character emitted from
all elements on each layer. The percentages of all elements were
found in the following order: carbon (C) > oxygen (O) > calcium
(Ca) > sulfur (S) > potassium (K) > aluminum (Al) > iodine (I) >
silicon (Si) > chlorine (Cl) > sodium (Na) > fluorine (F) >
phosphorus (P) > magnesium (Mg). Each layer consisted of high
percentage of CaCO3 (approximately 98%) implying that it was
essential for turtle embryonic development. A significant difference
was found in the percentages of Ca and Mo in the 3layers. Moreover,
transition metal, metal and toxic non-metal contaminations were
found in leatherback turtle eggshell samples. These were palladium
(Pd), molybdenum (Mo), copper (Cu), aluminum (Al), lead (Pb), and
bromine (Br). The contamination elements were seen in the outer
layers except for Mo. All elements were readily observed and
mapped using Smiling program. X-ray images which mapped the
location of all elements were showed. Calcium containing in the
eggshell appeared in high contents and was widely distributing in
clusters of the outer cuticle layer to form CaCO3 structure. Moreover,
the accumulation of Na and Cl was observed to form NaCl which was
widely distributing in 3 eggshell layers. The results from this study
would be valuable on assessing the emergent success in this
endangered species.
Abstract: We present an operator for a propositional linear temporal logic over infinite schedules of iterated transactions, which, when applied to a formula, asserts that any schedule satisfying the formula is serializable. The resulting logic is suitable for specifying and verifying consistency properties of concurrent transaction management systems, that can be defined in terms of serializability, as well as other general safety and liveness properties. A strict form of serializability is used requiring that, whenever the read and write steps of a transaction occurrence precede the read and write steps of another transaction occurrence in a schedule, the first transaction must precede the second transaction in an equivalent serial schedule. This work improves on previous work in providing a propositional temporal logic with a serializability operator that is of the same PSPACE complete computational complexity as standard propositional linear temporal logic without a serializability operator.
Abstract: The radio frequency identification (RFID) is a
technology for automatic identification of items, particularly in
supply chain, but it is becoming increasingly important for industrial
applications. Unlike barcode technology that detects the optical
signals reflected from barcode labels, RFID uses radio waves to
transmit the information from an RFID tag affixed to the physical
object. In contrast to today most often use of this technology in
warehouse inventory and supply chain, the focus of this paper is an
overview of the structure of RFID systems used by RFID technology
and it also presents a solution based on the application of RFID for
brand authentication, traceability and tracking, by implementing a
production management system and extending its use to traders.
Abstract: A new method for low complexity image coding is presented, that permits different settings and great scalability in the generation of the final bit stream. This coding presents a continuoustone still image compression system that groups loss and lossless compression making use of finite arithmetic reversible transforms. Both transformation in the space of color and wavelet transformation are reversible. The transformed coefficients are coded by means of a coding system in depending on a subdivision into smaller components (CFDS) similar to the bit importance codification. The subcomponents so obtained are reordered by means of a highly configure alignment system depending on the application that makes possible the re-configure of the elements of the image and obtaining different levels of importance from which the bit stream will be generated. The subcomponents of each level of importance are coded using a variable length entropy coding system (VBLm) that permits the generation of an embedded bit stream. This bit stream supposes itself a bit stream that codes a compressed still image. However, the use of a packing system on the bit stream after the VBLm allows the realization of a final highly scalable bit stream from a basic image level and one or several enhance levels.
Abstract: During the last few decades in the academic field, the
debate has increased on the effects of social geography on the
opportunities of socioeconomic integration. On one hand, it has been
discussed how the contents of the urban structure and social
geography affect not only the way people interact, but also their
chances of social and economic integration. On the other hand, it has
also been discussed how the urban structure is also constrained and
transformed by the action of social actors. Without questioning the
powerful influence of structural factors, related to the logic of the
production system, labor markets, education and training, the
research has shown the role played by place of residence in shaping
individual outcomes such as unemployment. In the context of this
debate the importance of territory of residence with respect to the
problem of unemployment has been highlighted.
Although statistics of unemployment have already demonstrated
the unequal incidence of the phenomenon in social groups, the issue
of uneven territorial impact on the phenomenon at intra-urban level
remains relatively unknown.
The purpose of this article is to show and to interpret the spatial
patterns of unemployment in the city of Porto using GIS (Geographic
Information System - GIS) technology. Under this analysis the
overlap of the spatial patterns of unemployment with the spatial
distribution of social housing, allows the discussion of the
relationship that occurs between these patterns and the reasons that
might explain the relative immutability of socioeconomic problems in
some neighborhoods.
Abstract: Existing work in temporal logic on representing the
execution of infinitely many transactions, uses linear-time temporal
logic (LTL) and only models two-step transactions. In this paper,
we use the comparatively efficient branching-time computational tree
logic CTL and extend the transaction model to a class of multistep
transactions, by introducing distinguished propositional variables
to represent the read and write steps of n multi-step transactions
accessing m data items infinitely many times. We prove that the
well known correspondence between acyclicity of conflict graphs
and serializability for finite schedules, extends to infinite schedules.
Furthermore, in the case of transactions accessing the same set of
data items in (possibly) different orders, serializability corresponds
to the absence of cycles of length two. This result is used to give an
efficient encoding of the serializability condition into CTL.
Abstract: For broadband wireless mobile communication
systems the orthogonal frequency division multiplexing (OFDM) is a
suitable modulation scheme. The frequency offset between
transmitter and receiver local oscillator is main drawback of OFDM
systems, which causes intercarrier interference (ICI) in the
subcarriers of the OFDM system. This ICI degrades the bit error rate
(BER) performance of the system. In this paper an improved self-ICI
cancellation scheme is proposed to improve the system performance.
The proposed scheme is based on discrete Fourier transform-inverse
discrete Fourier transform (DFT-IDFT). The simulation results show
that there is satisfactory improvement in the bit error rate (BER)
performance of the present scheme.
Abstract: The huge development of new technologies and the
apparition of open communication system more and more
sophisticated create a new challenge to protect digital content from
piracy. Digital watermarking is a recent research axis and a new
technique suggested as a solution to these problems. This technique
consists in inserting identification information (watermark) into
digital data (audio, video, image, databases...) in an invisible and
indelible manner and in such a way not to degrade original medium-s
quality. Moreover, we must be able to correctly extract the
watermark despite the deterioration of the watermarked medium (i.e
attacks). In this paper we propose a system for watermarking satellite
images. We chose to embed the watermark into frequency domain,
precisely the discrete wavelet transform (DWT). We applied our
algorithm on satellite images of Tunisian center. The experiments
show satisfying results. In addition, our algorithm showed an
important resistance facing different attacks, notably the compression
(JEPG, JPEG2000), the filtering, the histogram-s manipulation and
geometric distortions such as rotation, cropping, scaling.
Abstract: In literatures, many researches proposed various
methods to reduce PAPR (Peak to Average Power Ratio). Among
those, DSI (Dummy Sequence Insertion) is one of the most attractive
methods for WiMAX systems because it does not require side
information transmitted along with user data. However, the
conventional DSI methods find dummy sequence by performing an
iterative procedure until achieving PAPR under a desired threshold.
This causes a significant delay on finding dummy sequence and also
effects to the overall performances in WiMAX systems. In this paper,
the new method based on DSI is proposed by finding dummy
sequence without the need of iterative procedure. The fast DSI
method can reduce PAPR without either delays or required side
information. The simulation results confirm that the proposed method
is able to carry out PAPR performances as similar to the other
methods without any delays. In addition, the simulations of WiMAX
system with adaptive modulations are also investigated to realize the
use of proposed methods on various fading schemes. The results
suggest the WiMAX designers to modify a new Signal to Noise Ratio
(SNR) criteria for adaptation.
Abstract: The speculative locking (SL) protocol extends the twophase locking (2PL) protocol to allow for parallelism among conflicting transactions. The adaptive speculative locking (ASL) protocol provided further enhancements and outperformed SL protocols under most conditions. Neither of these protocols consider the impact of network latency on the performance of the distributed database systems. We have studied the performance of ASL protocol taking into account the communication overhead. The results indicate that though system load can counter network latency, it can still become a bottleneck in many situations. The impact of latency on performance depends on many factors including the system resources. A flexible discrete event simulator was used as the testbed for this study.
Abstract: Effective cooling of electronic equipment has emerged
as a challenging and constraining problem of the new century. In the
present work the feasibility and effectiveness of jet impingement
cooling on electronics were investigated numerically and
experimentally. Studies have been conducted to see the effect of the
geometrical parameters such as jet diameter (D), jet to target
spacing (Z) and ratio of jet spacing to jet diameter (Z/D) on the heat
transfer characteristics. The values of Reynolds numbers considered
are in the range 7000 to 42000. The results obtained from the
numerical studies are validated by conducting experiments. From the
studies it is found that the optimum value of Z/D ratio is 5. For a
given Reynolds number, the Nusselt number increases by about 28%
if the diameter of the nozzle is increased from 1mm to 2mm.
Correlations are proposed for Nusselt number in terms of Reynolds
number and these are valid for air as the cooling medium.