Abstract: The goal of this paper is to segment the countries
based on the value of export from Iran during 14 years ending at 2005. To measure the dissimilarity among export baskets of different countries, we define Dissimilarity Export Basket (DEB) function and
use this distance function in K-means algorithm. The DEB function
is defined based on the concepts of the association rules and the
value of export group-commodities. In this paper, clustering quality
function and clusters intraclass inertia are defined to, respectively,
calculate the optimum number of clusters and to compare the
functionality of DEB versus Euclidean distance. We have also study
the effects of importance weight in DEB function to improve
clustering quality. Lastly when segmentation is completed, a
designated RFM model is used to analyze the relative profitability of
each cluster.
Abstract: Absorptive characteristics of polyaniline synthesized
in mixture of water and acetonitrile in 50/50 volume ratio was
studied. Synthesized polyaniline in powder shape is used as an
adsorbent to remove toxic hexavalent chromium from aqueous
solutions. Experiments were conducted in batch mode with different
variables such as agitation time, solution pH and initial concentration
of hexavalent chromium. Removal mechanism is the combination of
surface adsorption and reduction. The equilibrium time for removal
of Cr(T) and Cr(VI) was about 2 and 10 minutes respectively. The
optimum pH for total chromium removal occurred at pH 7 and
maximum hexavalent chromium removal took place under acidic
condition at pH 3. Investigating the isothermal characteristics showed
that the equilibrium adsorption data fitted both Freundlich-s and
Langmuir-s isotherms. The maximum adsorption of chromium was
calculated 36.1 mg/g for polyaniline
Abstract: Endovascular aneurysm repair is a new and minimally invasive repair for patients with abdominal aortic aneurysm (AAA). This method has potential advantages that are incomparable with other repair methods. However, the enlargement of aneurysm in the absence of endoleak, which is known as endotension, may occur as one of post-operative compliances of this method. Typically, endotension is mainly as a result of pressure transmitted to aneurysm sac by endovascular installed graft. After installation of graft the aneurysm sac reduces significantly but remains non-zero. There are some factors which affect this pressure transmitted. In this study, the geometry features of installed vascular graft have been considered. It is inferred that graft neck angle and iliac bifurcation angle are two factors which can affect the drag force on graft and consequently the pressure transmitted to aneurysm.
Abstract: The anti-lock braking systems installed on vehicles
for safe and effective braking, are high-order nonlinear and timevariant.
Using fuzzy logic controllers increase efficiency of such
systems, but impose a high computational complexity as well. The
main concept introduced by this paper is reducing computational
complexity of fuzzy controllers by deploying problem-solution data
structure. Unlike conventional methods that are based on
calculations, this approach is based on data oriented modeling.
Abstract: In this paper a novel approach for generalized image
retrieval based on semantic contents is presented. A combination of
three feature extraction methods namely color, texture, and edge
histogram descriptor. There is a provision to add new features in
future for better retrieval efficiency. Any combination of these
methods, which is more appropriate for the application, can be used
for retrieval. This is provided through User Interface (UI) in the
form of relevance feedback. The image properties analyzed in this
work are by using computer vision and image processing algorithms.
For color the histogram of images are computed, for texture cooccurrence
matrix based entropy, energy, etc, are calculated and for
edge density it is Edge Histogram Descriptor (EHD) that is found.
For retrieval of images, a novel idea is developed based on greedy
strategy to reduce the computational complexity. The entire system
was developed using AForge.Imaging (an open source product),
MATLAB .NET Builder, C#, and Oracle 10g. The system was tested
with Coral Image database containing 1000 natural images and
achieved better results.
Abstract: In this research, effect of combustion reaction
mechanism on direct initiation of detonation has been studied
numerically. For this purpose, reaction mechanism has been
simulated by using a three-step chemical kinetics model. The reaction
scheme consists sequentially of a chain-initiation and chainbranching
step, followed by a temperature -independent chaintermination.
In a previous research, the effect of chain-branching on
the direct initiation of detonation is studied. In this research effect of
chain-initiation on direct initiation of detonation is investigated. For
the investigation, first a characteristic time (τ) for each step of
mechanism, which includes effect of different kinetics parameters, is
defined. Then the effect of characteristic time of chain-initiation (τI)
on critical initiation energy is studied. It is seen that increasing τI,
causes critical initiation energy to be increased. Drawing detonation's
shock pressure diagrams for different cases, shows that in small value
of τI , kinetics has more important effect on the behavior of the wave.
Abstract: Wall-surface jet induced by the dielectric barrier
discharge (DBD) has been proposed as an actuator for active flow
control in aerodynamic applications. Discharge plasma evolution of
the DBD plasma actuator was simulated based on a simple fluid model,
in which the electron, one type of positive ion and negative ion were
taken into account. Two-dimensional simulation was conducted, and
the results are in agreement with the insights obtained from
experimental studies. The simulation results indicate that the discharge
mode changes depending on applied voltage slope; when the applied
voltage is positive-going with high applied voltage slope, the
corona-type discharge mode turns into the streamer-type discharge
mode and the threshold voltage slope is around 300 kV/ms in this
simulation. The characteristics of the electrohydrodynamic (EHD)
force, which is the source of the wall-surface jet, also change
depending on the discharge mode; the tentative peak value of the EHD
force during the positive-going voltage phase is saturated by the
periodical formation of the streamer-type discharge.
Abstract: Sixteen female Holstein calves allocated in three
treatments including: 1: control, 2: fed raw fiber concentrate (RFC)
for 45 days and 3: fed RFC for 90 days. RFC supplement (Vitacel®
200) was added to milk immediately before feeding (10 g/L milk).
Withers height and body weights of calves were measured monthly.
Individual dry matter intake was recorded daily. Blood samples were
taken monthly. The result showed that calves consumed RFC had
significantly greater weaning and final body weight. Treatment effect
on dry matter intake was not significant (p>0.05). Calves fed RFC
had better feed efficiency. Withers height of calves fed RFC were
taller than the control group (p
Abstract: In this paper we present a linear autozeroing ultra lowvoltage amplifier. The autozeroing performed by all ULV circuits is important to reduce the impact of noise and especially avoid power supply noise in mixed signal low-voltage CMOS circuits. The simulated data presented is relevant for a 90nm TSMC CMOS process.
Abstract: The volume of XML data exchange is explosively increasing, and the need for efficient mechanisms of XML data management is vital. Many XML storage models have been proposed for storing XML DTD-independent documents in relational database systems. Benchmarking is the best way to highlight pros and cons of different approaches. In this study, we use a common benchmarking scheme, known as XMark to compare the most cited and newly proposed DTD-independent methods in terms of logical reads, physical I/O, CPU time and duration. We show the effect of Label Path, extracting values and storing in another table and type of join needed for each method's query answering.
Abstract: Residue Number System (RNS) is a modular representation and is proved to be an instrumental tool in many digital signal processing (DSP) applications which require high-speed computations. RNS is an integer and non weighted number system; it can support parallel, carry-free, high-speed and low power arithmetic. A very interesting correspondence exists between the concepts of Multiple Valued Logic (MVL) and Residue Number Arithmetic. If the number of levels used to represent MVL signals is chosen to be consistent with the moduli which create the finite rings in the RNS, MVL becomes a very natural representation for the RNS. There are two concerns related to the application of this Number System: reaching the most possible speed and the largest dynamic range. There is a conflict when one wants to resolve both these problem. That is augmenting the dynamic range results in reducing the speed in the same time. For achieving the most performance a method is considere named “One-Hot Residue Number System" in this implementation the propagation is only equal to one transistor delay. The problem with this method is the huge increase in the number of transistors they are increased in order m2 . In real application this is practically impossible. In this paper combining the Multiple Valued Logic and One-Hot Residue Number System we represent a new method to resolve both of these two problems. In this paper we represent a novel design of an OHRNS-based adder circuit. This circuit is useable for Multiple Valued Logic moduli, in comparison to other RNS design; this circuit has considerably improved the number of transistors and power consumption.
Abstract: Finding the interpolation function of a given set of nodes is an important problem in scientific computing. In this work a kind of localization is introduced using the radial basis functions which finds a sufficiently smooth solution without consuming large amount of time and computer memory. Some examples will be presented to show the efficiency of the new method.
Abstract: This paper provides a framework in order to
incorporate reliability issue as a sign of disruption in distribution
systems and partial covering theory as a response to limitation in
coverage radios and economical preferences, simultaneously into the
traditional literatures of capacitated facility location problems. As a
result we develop a bi-objective model based on the discrete
scenarios for expected cost minimization and demands coverage
maximization through a three echelon supply chain network by
facilitating multi-capacity levels for provider side layers and
imposing gradual coverage function for distribution centers (DCs).
Additionally, in spite of objectives aggregation for solving the model
through LINGO software, a branch of LP-Metric method called Min-
Max approach is proposed and different aspects of corresponds
model will be explored.
Abstract: Sustainable development is a concept which was
originated in Burtland commission in 1978. Although this concept
was born with environmental aspects, it is penetrated in all areas
rapidly, turning into a dominate view of planning. Concentrating on
future generation issue, especially when talking about heritage has a
long story. Each approach with all of its characteristics illustrates
differences in planning, hence planning always reflects the dominate
idea of its age. This paper studies sustainable development in
planning for historical cities with the aim of finding ways to deal
with heritage in planning for historical cities in Iran. Through this, it
will be illustrated how challenges between sustainable concept and
heritage could be concluded in planning.
Consequently, the paper will emphasize on:
Sustainable development in city planning
Trends regarding heritage
Challenges due to planning for historical cities in Iran
For the first two issues, documentary method regarding the
sustainable development and heritage literature is considered. As the
next step focusing on Iranian historical cities require considering the
urban planning and management structure and identifying the main
challenges related to heritage, so analyzing challenges regarding
heritage is considered. As the result it would be illustrated that key
issue in such planning is active conservation to improve and use the
potential of heritage while it's continues conservation is guaranteed.
By emphasizing on the planning system in Iran it will be obvious that
some reforms are needed in this system and its way of relating with
heritage. The main weakness in planning for historical cities in Iran
is the lack of independent city management. Without this factor
achieving active conservation as the main factor of sustainable
development would not be possible.
Abstract: In the current economy of increasing global
competition, many organizations are attempting to use knowledge as
one of the means to gain sustainable competitive advantage. Besides
large organizations, the success of SMEs can be linked to how well
they manage their knowledge. Despite the profusion of research
about knowledge management within large organizations, fewer
studies tried to analyze KM in SMEs.
This research proposes a new framework showing the determinant
role of organizational dimensions onto KM approaches. The paper
and its propositions are based on a literature review and analysis.
In this research, personalization versus codification,
individualization versus institutionalization and IT-based versus non
IT-based are highlighted as three distinct dimensions of knowledge
management approaches.
The study contributes to research by providing a more nuanced
classification of KM approaches and provides guidance to managers
about the types of KM approaches that should be adopted based on
the size, geographical dispersion and task nature of SMEs.
To the author-s knowledge, the paper is the first of its kind to
examine if there are suitable configurations of KM approaches for
SMEs with different dimensions. It gives valuable information, which
hopefully will help SME sector to accomplish KM.
Abstract: Intelligent schools are those which use IT devices and
technologies as media software, hardware and networks to improve
learning process. On the other hand management improvement is
best described as the process from which managers learn and improve
their skills not only to benefit themselves but also their employing
organizations Here, we present a model Management improvement
System that has been applied on some schools and have made strict
improvement.
Abstract: Applying corona wind as a novel technique can lead
to a great level of heat and mass transfer augmentation by using very
small amount of energy. Enhancement of forced flow evaporation
rate by applying electric field (corona wind) has been experimentally
evaluated in this study. Corona wind produced by a fine wire
electrode which is charged with positive high DC voltage impinges
to water surface and leads to evaporation enhancement by disturbing
the saturated air layer over water surface. The study was focused on
the effect of corona wind velocity, electrode spacing and air flow
velocity on the level of evaporation enhancement. Two sets of
experiments, i.e. with and without electric field, have been
conducted. Data obtained from the first experiment were used as
reference for evaluation of evaporation enhancement at the presence
of electric field. Applied voltages ranged from corona threshold
voltage to spark over voltage at 1 kV increments. The results showed
that corona wind has great enhancement effect on water evaporation
rate, but its effectiveness gradually diminishes by increasing air flow
velocity. Maximum enhancements were 7.3 and 3.6 for air velocities
of 0.125 and 1.75 m/s, respectively.
Abstract: In the following text, we show that by introducing
universal kinetic scheme, the origin of rate retardation and inhibition
period which observed in dithiobenzoate-mediated RAFT
polymerization can be described properly. We develop our model by
utilizing the method of moments, then we apply our model to
different monomer/RAFT agent systems, both homo- and
copolymerization. The modeling results are in an excellent
agreement with experiments and imply the validity of universal
kinetic scheme, not only for dithiobenzoate-mediated systems, but
also for different types of monomer/RAFT agent ones.
Abstract: From the beginning of creation, human being has ever
fought against the ecosystem by changes has made in environment.
The most environmental changes on the nature have been done after
starting the concentrated life in the same region. Dams are one of the
most important buildings in water resources and transferring. These
buildings have been made from old times without access to
hydrological, hydraulically, hydro mechanical information. Dams
have positive and negative effects on environment. Constructing a
dam relatively causes equal ecological consequences. According to
different criteria, environmental effects of dams can lead short term
and long term damages. These effects may influence on the situation
and treatment of meteorology, biology, culture, ancient works, etc
and severely causes to change and complicate it. So considering
importance of positive effects of dam construction, it is necessary to
minimize negative environmental effects of dams to achieve a stable
development. In this article the considered effects and their solutions
in influencing on assessment of destructive environmental effects of
dams construction have been surveyed and presented.
Abstract: This paper presents a VLSI design approach of a highspeed
and real-time 2-D Discrete Wavelet Transform computing. The
proposed architecture, based on new and fast convolution approach,
reduces the hardware complexity in addition to reduce the critical
path to the multiplier delay. Furthermore, an advanced twodimensional
(2-D) discrete wavelet transform (DWT)
implementation, with an efficient memory area, is designed to
produce one output in every clock cycle. As a result, a very highspeed
is attained. The system is verified, using JPEG2000
coefficients filters, on Xilinx Virtex-II Field Programmable Gate
Array (FPGA) device without accessing any external memory. The
resulting computing rate is up to 270 M samples/s and the (9,7) 2-D
wavelet filter uses only 18 kb of memory (16 kb of first-in-first-out
memory) with 256×256 image size. In this way, the developed design
requests reduced memory and provide very high-speed processing as
well as high PSNR quality.