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 bioassay-guided isolation and purification of an
ethyl acetate extract of Aspergillus terreus MC751 led to the
characterization of butyrolactone I as an antidiabetic and antioxidant.
The antidiabetic activity of butyrolactone I was evaluated by α-
glucosidase and α-amylase inhibition assays. Butyrolactone I
demonstrated significant concentration-dependent, mixed-type
inhibitory activity against yeast α-glucosidase with an IC50 of 54μM.
However, the compound exhibited less activity against rat intestinal
α-glucosidase and α-amylase. This is the first report on α-glucosidase
inhibitory activity of butyrolactone I. The antioxidative activity of
butyrolactone I was evaluated based on scavenging effects on 1,1-
diphenyl-2-picrylhydrazyl (DPPH) (IC50 =51 μM) and hydrogen
peroxide (IC50= 141 μM) radicals as well as a reducing power assay.
The results suggest that butyrolactone I is a promising antidiabetic as
well as antioxidant and should be considered for clinical trials.
Abstract: This research examines possible effects of climatic
change focusing on global warming and its impacts on world
agricultural product markets, by using a world food model developed
to consider climate changes. GDP and population for each scenario
were constructed by IPCC and climate data for each scenario was
reported by the Hadley Center and are used in this research to consider
results in different contexts. Production and consumption of primary
agriculture crops of the world for each socio-economic scenario are
obtained and investigated by using the modified world food model.
Simulation results show that crop production in some countries or
regions will have different trends depending on the context. These
alternative contexts depend on the rate of GDP growth, population,
temperature, and rainfall. Results suggest that the development of
environment friendly technologies lead to more consumption of food
in many developing countries. Relationships among environmental
policy, clean energy development, and poverty elimination warrant
further investigation.
Abstract: Phase locked loops (PLL) and delay locked loops (DLL) play an important role in establishing coherent references (phase of carrier and symbol timing) in digital communication systems. Fully digital receiver including digital carrier synchronizer and symbol timing synchronizer fulfils the conditions for universal multi-mode communication receiver with option of symbol rate setting over several digit places and long-term stability of requirement parameters. Afterwards it is necessary to realize PLL and DLL in synchronizer in digital form and to approach to these subsystems as a discrete representation of analog template. Analysis of discrete phase locked loop (DPLL) or discrete delay locked loop (DDLL) and technique to determine their characteristics based on analog (continuous-time) template is performed in this posed paper. There are derived transmission response and error function for 1st order discrete locked loop and resulting equations and graphical representations for 2nd order one. It is shown that the spectrum translation due to sampling takes effect at frequency characteristics computing for specific values of loop parameters.
Abstract: In this paper a new method for increasing the speed of
SAGCM-APD is proposed. Utilizing carrier rate equations in
different regions of the structure, a circuit model for the structure is
obtained. In this research, in addition to frequency response, the
effect of added new charge layer on some transient parameters like
slew-rate, rising and falling times have been considered. Finally, by
trading-off among some physical parameters such as different layers
widths and droppings, a noticeable decrease in breakdown voltage
has been achieved. The results of simulation, illustrate some features
of proposed structure improvement in comparison with conventional
SAGCM-APD structures.
Abstract: In this paper multivariable predictive PID controller has
been implemented on a multi-inputs multi-outputs control problem
i.e., quadruple tank system, in comparison with a simple multiloop
PI controller. One of the salient feature of this system is an
adjustable transmission zero which can be adjust to operate in both
minimum and non-minimum phase configuration, through the flow
distribution to upper and lower tanks in quadruple tank system.
Stability and performance analysis has also been carried out for this
highly interactive two input two output system, both in minimum
and non-minimum phases. Simulations of control system revealed
that better performance are obtained in predictive PID design.
Abstract: The speech signal conveys information about the
identity of the speaker. The area of speaker identification is
concerned with extracting the identity of the person speaking the
utterance. As speech interaction with computers becomes more
pervasive in activities such as the telephone, financial transactions
and information retrieval from speech databases, the utility of
automatically identifying a speaker is based solely on vocal
characteristic. This paper emphasizes on text dependent speaker
identification, which deals with detecting a particular speaker from a
known population. The system prompts the user to provide speech
utterance. System identifies the user by comparing the codebook of
speech utterance with those of the stored in the database and lists,
which contain the most likely speakers, could have given that speech
utterance. The speech signal is recorded for N speakers further the
features are extracted. Feature extraction is done by means of LPC
coefficients, calculating AMDF, and DFT. The neural network is
trained by applying these features as input parameters. The features
are stored in templates for further comparison. The features for the
speaker who has to be identified are extracted and compared with the
stored templates using Back Propogation Algorithm. Here, the
trained network corresponds to the output; the input is the extracted
features of the speaker to be identified. The network does the weight
adjustment and the best match is found to identify the speaker. The
number of epochs required to get the target decides the network
performance.
Abstract: This paper presents the impact study of GTO Controlled Series Capacitor (GCSC) parameters on measured impedance (Zseen) by MHO distance relays for single transmission line high voltage 220 kV in the presence of single phase to earth fault with fault resistance (RF). The study deals with a 220 kV single electrical transmission line of Eastern Algerian transmission networks at Group Sonelgaz (Algerian Company of Electrical and Gas) compensated by series Flexible AC Transmission System (FACTS) i.e. GCSC connected at midpoint of the transmission line. The transmitted active and reactive powers are controlled by three GCSC-s. The effects of maximum reactive power injected as well as injected maximum voltage by GCSC on distance relays measured impedance is treated. The simulations results investigate the effects of GCSC injected parameters: variable reactance (XGCSC), variable voltage (VGCSC) and reactive power injected (QGCSC) on measured resistance and reactance in the presence of earth fault with resistance fault varied between 5 to 50 Ω for three cases study.
Abstract: The dynamics of User Datagram Protocol (UDP) traffic
over Ethernet between two computers are analyzed using nonlinear
dynamics which shows that there are two clear regimes in the data
flow: free flow and saturated. The two most important variables
affecting this are the packet size and packet flow rate. However,
this transition is due to a transcritical bifurcation rather than phase
transition in models such as in vehicle traffic or theorized large-scale
computer network congestion. It is hoped this model will help lay
the groundwork for further research on the dynamics of networks,
especially computer networks.
Abstract: High speed networks provide realtime variable bit rate
service with diversified traffic flow characteristics and quality
requirements. The variable bit rate traffic has stringent delay and
packet loss requirements. The burstiness of the correlated traffic
makes dynamic buffer management highly desirable to satisfy the
Quality of Service (QoS) requirements. This paper presents an
algorithm for optimization of adaptive buffer allocation scheme for
traffic based on loss of consecutive packets in data-stream and buffer
occupancy level. Buffer is designed to allow the input traffic to be
partitioned into different priority classes and based on the input
traffic behavior it controls the threshold dynamically. This algorithm
allows input packets to enter into buffer if its occupancy level is less
than the threshold value for priority of that packet. The threshold is
dynamically varied in runtime based on packet loss behavior. The
simulation is run for two priority classes of the input traffic –
realtime and non-realtime classes. The simulation results show that
Adaptive Partial Buffer Sharing (ADPBS) has better performance
than Static Partial Buffer Sharing (SPBS) and First In First Out
(FIFO) queue under the same traffic conditions.
Abstract: This paper presents a mathematical model and a
methodology to analyze the losses in transmission expansion
planning (TEP) under uncertainty in demand. The methodology is
based on discrete particle swarm optimization (DPSO). DPSO is a
useful and powerful stochastic evolutionary algorithm to solve the
large-scale, discrete and nonlinear optimization problems like TEP.
The effectiveness of the proposed idea is tested on an actual
transmission network of the Azerbaijan regional electric company,
Iran. The simulation results show that considering the losses even for
transmission expansion planning of a network with low load growth
is caused that operational costs decreases considerably and the
network satisfies the requirement of delivering electric power more
reliable to load centers.
Abstract: The notion of Next Generation Network (NGN) is
based on the Network Convergence concept which refers to
integration of services (such as IT and communication services) over
IP layer. As the most popular implementation of Service Oriented
Architecture (SOA), Web Services technology is known to be the
base for service integration. In this paper, we present a platform to
deliver communication services as web services. We also implement
a sample service to show the simplicity of making composite web
and communication services using this platform. A Service Logic
Execution Environment (SLEE) is used to implement the
communication services. The proposed architecture is in agreement
with Service Oriented Architecture (SOA) and also can be integrated
to an Enterprise Service Bus to make a base for NGN Service
Delivery Platform (SDP).
Abstract: With the advance in wireless networking, IEEE 802.16 WiMAX technology has been widely deployed for several applications such as “last mile" broadband service, cellular backhaul, and high-speed enterprise connectivity. As a result, military employed WiMAX as a high-speed wireless connection for data-link because of its point to multi-point and non-line-of-sight (NLOS) capability for many years. However, the risk of using WiMAX is a critical factor in some sensitive area of military applications especially in ammunition manufacturing such as solid propellant rocket production. The US DoD policy states that the following certification requirements are met for WiMAX: electromagnetic effects on the environment (E3) and Hazards of Electromagnetic Radiation to Ordnance (HERO). This paper discuses the Recommended Power Densities and Safe Separation Distance (SSD) for HERO on WiMAX systems deployed on solid propellant rocket production. The result of this research found that WiMAX is safe to operate at close proximity distances to the rocket production based on AF Guidance Memorandum immediately changing AFMAN 91-201.
Abstract: HSDPA is a new feature which is introduced in
Release-5 specifications of the 3GPP WCDMA/UTRA standard to
realize higher speed data rate together with lower round-trip times.
Moreover, the HSDPA concept offers outstanding improvement of
packet throughput and also significantly reduces the packet call
transfer delay as compared to Release -99 DSCH. Till now the
HSDPA system uses turbo coding which is the best coding technique
to achieve the Shannon limit. However, the main drawbacks of turbo
coding are high decoding complexity and high latency which makes
it unsuitable for some applications like satellite communications,
since the transmission distance itself introduces latency due to
limited speed of light. Hence in this paper it is proposed to use LDPC
coding in place of Turbo coding for HSDPA system which decreases
the latency and decoding complexity. But LDPC coding increases the
Encoding complexity. Though the complexity of transmitter
increases at NodeB, the End user is at an advantage in terms of
receiver complexity and Bit- error rate. In this paper LDPC Encoder
is implemented using “sparse parity check matrix" H to generate a
codeword at Encoder and “Belief Propagation algorithm "for LDPC
decoding .Simulation results shows that in LDPC coding the BER
suddenly drops as the number of iterations increase with a small
increase in Eb/No. Which is not possible in Turbo coding. Also same
BER was achieved using less number of iterations and hence the
latency and receiver complexity has decreased for LDPC coding.
HSDPA increases the downlink data rate within a cell to a theoretical
maximum of 14Mbps, with 2Mbps on the uplink. The changes that
HSDPA enables includes better quality, more reliable and more
robust data services. In other words, while realistic data rates are
only a few Mbps, the actual quality and number of users achieved
will improve significantly.
Abstract: This paper mainly about the study on one of the
widely used error correcting codes that is Low parity check Codes
(LDPC). In this paper, the Regular LDPC code has been discussed
The LDPC codes explained in this paper is about the Regular Binary
LDPC codes or the Gallager.
Abstract: In image processing and visualization, comparing two
bitmapped images needs to be compared from their pixels by matching
pixel-by-pixel. Consequently, it takes a lot of computational time
while the comparison of two vector-based images is significantly
faster. Sometimes these raster graphics images can be approximately
converted into the vector-based images by various techniques. After
conversion, the problem of comparing two raster graphics images
can be reduced to the problem of comparing vector graphics images.
Hence, the problem of comparing pixel-by-pixel can be reduced to
the problem of polynomial comparisons. In computer aided geometric
design (CAGD), the vector graphics images are the composition of
curves and surfaces. Curves are defined by a sequence of control
points and their polynomials. In this paper, the control points will be
considerably used to compare curves. The same curves after relocated
or rotated are treated to be equivalent while two curves after different
scaled are considered to be similar curves. This paper proposed an
algorithm for comparing the polynomial curves by using the control
points for equivalence and similarity. In addition, the geometric
object-oriented database used to keep the curve information has also
been defined in XML format for further used in curve comparisons.
Abstract: Many experimental results suggest that more precise
spike timing is significant in neural information processing. We
construct a self-organization model using the spatiotemporal patterns,
where Spike-Timing Dependent Plasticity (STDP) tunes the
conduction delays between neurons. We show that the fluctuation of
conduction delays causes globally continuous and locally distributed
firing patterns through the self-organization.
Abstract: Tourism and coastal lines are the business sectors
since centuries especially in the European Nations and Albania is one
such spots. However, in recent decades tourism is experienced as
vulnerability of the surrounding ecological conditions of air, soil,
water, land and the communities that are dependant and sharing the
ecosystem among flora and fauna. Experts opine that apart from the
maintenance of near-originality of ecological biodiversity the tourism
rather known as ecotourism an indigenous socio-cultural
maintenance of indigenous/traditional knowledge of the local people
must be well cared in order to sustain on sustainable grounds. As a
general tendency, growth of tourism has been affected by the deterioration in the economic conditions on one aspect and unsustainable ecological areas affected since human interventions
earlier to this has negative impact on futuristic tourist spots. However, tourism in Albania as of now is 11% of GDP and coastal regions accounting to 2-4%. An amicable Mediterranean
climate with 300 sunny days similar parameters of Greece and Spain
throws up sustainable ecotourism in future decades provided public services namely, transportation, road safety, lodging, food
availability, recreational regiments, banking accessibility are as per
the World Tourism Organizations- protocols. Thus as of Albanian
situation, classification of ecotourism activities to safe-guard the localities with its maintenance of ecological land, water and climate
has become a paramount importance with a wanting and satisfactory options through harnessing human energy for profit and fitness of
ecological flora and fauna. A check on anthropogenic wastes and
their safer utilizations inclusive of agricultural and industrial
operations in line with Lalzi Bay Coastal Line are of utmost importance for the reason that the Adriatic Sea Coast is the one long
stretch of Albanian Lifeline. The present work is based on the methodology of the sustainable management of the same issue.
Abstract: In this paper, an analytical approach for free vibration
analysis of four edges simply supported rectangular Kirchhoff plates
is presented. The method is based on wave approach. From wave
standpoint vibration propagate, reflect and transmit in a structure.
Firstly, the propagation and reflection matrices for plate with simply
supported boundary condition are derived. Then, these matrices are
combined to provide a concise and systematic approach to free
vibration analysis of a simply supported rectangular Kirchhoff plate.
Subsequently, the eigenvalue problem for free vibration of plates is
formulated and the equation of plate natural frequencies is
constructed. Finally, the effectiveness of the approach is shown by
comparison of the results with existing classical solution.
Abstract: Data stream analysis is the process of computing
various summaries and derived values from large amounts of data
which are continuously generated at a rapid rate. The nature of a
stream does not allow a revisit on each data element. Furthermore,
data processing must be fast to produce timely analysis results. These
requirements impose constraints on the design of the algorithms to
balance correctness against timely responses. Several techniques
have been proposed over the past few years to address these
challenges. These techniques can be categorized as either dataoriented
or task-oriented. The data-oriented approach analyzes a
subset of data or a smaller transformed representation, whereas taskoriented
scheme solves the problem directly via approximation
techniques. We propose a hybrid approach to tackle the data stream
analysis problem. The data stream has been both statistically
transformed to a smaller size and computationally approximated its
characteristics. We adopt a Monte Carlo method in the approximation
step. The data reduction has been performed horizontally and
vertically through our EMR sampling method. The proposed method
is analyzed by a series of experiments. We apply our algorithm on
clustering and classification tasks to evaluate the utility of our
approach.