Abstract: The standard approach to image reconstruction is to stabilize the problem by including an edge-preserving roughness penalty in addition to faithfulness to the data. However, this methodology produces noisy object boundaries and creates a staircase effect. The existing attempts to favor the formation of smooth contour lines take the edge field explicitly into account; they either are computationally expensive or produce disappointing results. In this paper, we propose to incorporate the smoothness of the edge field in an implicit way by means of an additional penalty term defined in the wavelet domain. We also derive an efficient half-quadratic algorithm to solve the resulting optimization problem, including the case when the data fidelity term is non-quadratic and the cost function is nonconvex. Numerical experiments show that our technique preserves edge sharpness while smoothing contour lines; it produces visually pleasing reconstructions which are quantitatively better than those obtained without wavelet-domain constraints.
Abstract: The reservoir of Kowsar dam supply water for
different usages such as aquaculture farms , drinking, agricultural and
industrial usages for some provinces in south of Iran. The Kowsar
dam is located next to the city of Dehdashat in Kohgiluye and
Boyerahmad province in southern Iran. There are some towns and
villages on the Kowsar dam watersheds, which Dehdasht and Choram
are the most important and populated twons in this area, which can to
be sources of pollution for water reservoir of the Kowsar dam . This
study was done to determine of water pollution of the Kowsar dam
reservoir which is one of the most important water resources of
Kohkiloye and Boyerahmad and Bushehr provinces in south-west
Iran. In this study , water samples during 12 months were collected to
examine Biochemical Oxygen Demand (BOD) and Dissolved
Oxygen(DO) as a criterion for evaluation of water pollution of the
reservoir. In summary ,the study has shown Maximum, average and
minimum levels of BOD have observed 25.9 ,9.15 and 2.3 mg/L
respectively and statistical parameters of data such as standard
deviation , variance and skewness have calculated 7.88, 62 and 1.54
respectively. Finally the results were compared with Iranian national
standards. Among the analyzed samples, as the maximum value of
BOD (25.9 mg/L) was observed at the May 2010 , was within the
maximum admissible limits by the Iranian standards.
Abstract: An efficient and green protocol for the synthesis of α-
aminonitriles derivatives by one-pot reaction of different aldehydes
with amines and trimethylsilyl cyanides has been developed using
natural alumina, alumina sulfuric acid (ASA), nano-γ-alumina, nanoalumina
sulfuric acid (nano-ASA) under microwave irradiation and
solvent-free conditions. The advantages of methods are short reaction
times, high yields, milder conditions and easy work up. The catalysts
can be recovered for the subsequent reactions and reused without any
appreciable loss of efficiency.
Abstract: A liquid curved jet has many applications in different
industrial and engineering processes, such as the prilling process
for generating small spherical pellets (fertilizer or magnesium). The
liquids used are usually molten and contain small quantities of
polymers and therefore can be modelled as non-Newtonian liquids. In
this paper, we model the viscoelastic liquid jet by using the Oldroyd-
B model. An asymptotic analysis has been used to simplify the
governing equations. Furthermore, the trajectory and a linear temporal
stability in the presence of gravity and rotation have been determined.
Abstract: In this study, the two dimensional heat conduction
problem for the dry friction clutch disc is modeled mathematically
analysis and is solved numerically using finite element method, to
determine the temperature field when band contacts occurs between
the rubbing surfaces during the operation of an automotive clutch.
Temperature calculation have been made for contact area of different
band width and the results obtained compared with these attained
when complete contact occurs. Furthermore, the effects of slipping
time and sliding velocity function are investigated as well. Both
single and repeated engagements made at regular interval are
considered.
Abstract: Natural ventilation has played an important role for
many low energy-building designs. It has been also noticed as a
essential subject to persistently bring the fresh cool air from the
outside into a building. This study carried out the computational fluid
dynamics (CFD)-based simulations to examine the natural ventilation
development of a work area in a public building. The simulated results
can be useful to better understand the indoor microclimate and the
interaction of wind with buildings. Besides, this CFD simulation
procedure can serve as an effective analysis tool to characterize the
airing performance, and thereby optimize the building ventilation for
strengthening the architects, planners and other decision makers on
improving the natural ventilation design of public buildings.
Abstract: In this paper, we propose a multiple objective optimization model with respect to portfolio selection problem for investors looking forward to diversify their equity investments in a number of equity markets. Based on Markowitz-s M-V model we developed a Fuzzy Mixed Integer Multi-Objective Nonlinear Programming Problem (FMIMONLP) to maximize the investors- future gains on equity markets, reach the optimal proportion of the budget to be invested in different equities. A numerical example with a comprehensive analysis on artificial data from several equity markets is presented in order to illustrate the proposed model and its solution method. The model performed well compared with the deterministic version of the model.
Abstract: This study aims at investigating the empirical
relationships between risk preference, internet preference, and
internet knowledge which are known as user characteristics, in
addition to perceived risk of the customers on the internet purchase
intention. In order to test the relationships between the variables of
model 174, a questionnaire was collected from the students with
previous online experience. For the purpose of data analysis,
confirmatory factor analysis (CFA) and structural equation model
(SEM) was used.
Test results show that the perceived risk affects the internet
purchase intention, and increase or decrease of perceived risk
influences the purchase intention when the customer does the internet
shopping. Other factors such as internet preference, knowledge of the
internet, and risk preference affect the internet purchase intention.
Abstract: This hypothesis shows that the induction and the
remanent of magnetic properties govern the mechanism processes of
DNA replication and the shortening of the telomere.
The solenoid–like formation of each parental DNA strand, which
exists at the initial stage of the replication process, enables an electric
charge transformation through the strand to produce a magnetic field.
The magnetic field, in turn, induces the surrounding medium to form
a new (replicated) strand by a remanent magnetisation. Through the
remanent [residual] magnetisation process, the replicated strand
possesses a similar information pattern to that of the parental strand.
In the same process, the remanent amount of magnetisation forms the
medium in which it has less of both repetitive and pattern
magnetisation than that of the parental strand, therefore the replicated
strand shows a shortening in the length of its telomeres.
Abstract: The influence of humidity and low temperature on the α- amylase activity and isoenzyme composition of grains of different wheat varieties have been studied. The identified samples of varieties have significant difference in the level of enzyme induction under the impact of high humidity and low temperature. It is proposed to use this methodological approach for testing genotypes and wheat breeding lines for resistance to pre-harvest sprouting (PHS).
Abstract: This paper presents the elastic buckling of
homogeneous beams with a pair of piezoelectric layers surface
bonded on both sides of the beams. The displacement field of beam is
assumed based on the Engesser-Timoshenko beam theory.
Applying the Hamilton's principle, the equilibrium equation is
established. The influences of applied voltage, dimensionless
geometrical parameter and piezoelectric thickness on the critical
buckling load of beam are presented. To investigate the accuracy of
the present analysis, a compression study is carried out with a known
data.
Abstract: We propose a novel prioritized limited
processor-sharing (PS) rule and a simulation algorithm for the performance evaluation of this rule. The performance measures of practical interest are evaluated using this algorithm. Suppose that there
are two classes and that an arriving (class-1 or class-2) request encounters n1 class-1 and n2 class-2 requests (including the arriving
one) in a single-server system. According to the proposed rule, class-1
requests individually and simultaneously receive m / (m * n1+ n2) of the service-facility capacity, whereas class-2 requests receive 1 / (m *n1 + n2) of it, if m * n1 + n2 ≤ C. Otherwise (m * n1 + n2 > C), the arriving request will be queued in the corresponding class waiting
room or rejected. Here, m (1) denotes the priority ratio, and C ( ∞), the service-facility capacity. In this rule, when a request arrives at [or
departs from] the system, the extension [shortening] of the remaining
sojourn time of each request receiving service can be calculated using
the number of requests of each class and the priority ratio. Employing
a simulation program to execute these events and calculations enables
us to analyze the performance of the proposed prioritized limited PS
rule, which is realistic in a time-sharing system (TSS) with a
sufficiently small time slot. Moreover, this simulation algorithm is
expanded for the evaluation of the prioritized limited PS system with
N 3 priority classes.
Abstract: ORC (Organic Rankine Cycle) has potential of
reducing consumption of fossil fuels and has many favorable
characteristics to exploit low-temperature heat sources. In this work
thermodynamic performance of ORC with regeneration is
comparatively assessed for various working fluids. Special attention is
paid to the effects of system parameters such as the turbine inlet
pressure on the characteristics of the system such as net work
production, heat input, volumetric flow rate per 1 MW of net work and
quality of the working fluid at turbine exit as well as thermal
efficiency. Results show that for a given source the thermal efficiency
generally increases with increasing of the turbine inlet pressure
however has optimal condition for working fluids of low critical
pressure such as iso-pentane or n-pentane.
Abstract: The scale dependence of the strength of virtually homogeneous rock is usually considered to be insignificant but the spectrum of discontinuities plays a very important role for the strength of differently sized rock elements and also controls the rock creep strain. Large-scale load tests comprised recording of the creep strain rate that was found to be strongly retarded and negligible for stresses lower than about 1/3 of the failure load. For higher stresses creep took place according to a log time law representing secondary creep that ultimately changed to tertiary creep and failure.
Abstract: Various mechanisms providing mutual exclusion and
thread synchronization can be used to support parallel processing
within a single computer. Instead of using locks, semaphores, barriers
or other traditional approaches in this paper we focus on alternative
ways for making better use of modern multithreaded architectures
and preparing hash tables for concurrent accesses. Hash structures
will be used to demonstrate and compare two entirely different
approaches (rule based cooperation and hardware synchronization
support) to an efficient parallel implementation using traditional
locks. Comparison includes implementation details, performance
ranking and scalability issues. We aim at understanding the effects
the parallelization schemes have on the execution environment with
special focus on the memory system and memory access
characteristics.
Abstract: Psoriasis is a widespread skin disease affecting up to 2% population with plaque psoriasis accounting to about 80%. It can be identified as a red lesion and for the higher severity the lesion is usually covered with rough scale. Psoriasis Area Severity Index (PASI) scoring is the gold standard method for measuring psoriasis severity. Scaliness is one of PASI parameter that needs to be quantified in PASI scoring. Surface roughness of lesion can be used as a scaliness feature, since existing scale on lesion surface makes the lesion rougher. The dermatologist usually assesses the severity through their tactile sense, therefore direct contact between doctor and patient is required. The problem is the doctor may not assess the lesion objectively. In this paper, a digital image analysis technique is developed to objectively determine the scaliness of the psoriasis lesion and provide the PASI scaliness score. Psoriasis lesion is modelled by a rough surface. The rough surface is created by superimposing a smooth average (curve) surface with a triangular waveform. For roughness determination, a polynomial surface fitting is used to estimate average surface followed by a subtraction between rough and average surface to give elevation surface (surface deviations). Roughness index is calculated by using average roughness equation to the height map matrix. The roughness algorithm has been tested to 444 lesion models. From roughness validation result, only 6 models can not be accepted (percentage error is greater than 10%). These errors occur due the scanned image quality. Roughness algorithm is validated for roughness measurement on abrasive papers at flat surface. The Pearson-s correlation coefficient of grade value (G) of abrasive paper and Ra is -0.9488, its shows there is a strong relation between G and Ra. The algorithm needs to be improved by surface filtering, especially to overcome a problem with noisy data.
Abstract: Drought is one of the most important natural disasters which is probable to occur in all regions with completely different climates and in addition to causing death. It results in many economic losses and social consequences. For this reason. Studying the effects and losses caused by drought which include limitation or shortage of agricultural and drinking water resources. Decreased rainfall and increased evapotranspiration. Limited plant growth and decreased agricultural products. Especially those of dry-farming. Lower levels of surface and ground waters and increased immigrations. Etc. in the country is statistical period (1988-2007) for six stations in Roudbar town were used for statistical analysis and calculating humid and dry years. The dependable rainfall index (DRI) was the main method used in this research. Results showed that during the said statistical period and also during the years 1996-1998 and 2007. more than half of the stations had faced drought. With consideration of the conducted studies. Drawing diagrams and comparing the available data with those of dry and humid years it was found that drought affected agricultural products (e.g.olive) in a way that during the year 1996 1996 drought. Olive groves of Roudbar suffered the greatest damages. Whereupon about 70% of the crops were lost.
Abstract: Corporate Social Responsibility (CSR) has become a
new trend of business governance. Few research studies on CSR
published in Taiwanese academia, especially for medical settings, we
were interested in probing the relationship of CSR and financial
performance in medical settings in Taiwan. The results illustrate that:
(1) a time delay effect exists with a lag between CSR effort and its
performance in the hospital foundation, (2) input into the internal
domains of CSR will be helpful to improve employee productivity in
the hospital foundation, and (3) input into the external domains of CSR
will be helpful in improving financial performance in the hospital
foundation. This study overviews CSR in the medical industry in
Taiwan and the relationship of CSR and financial performance.
Discussions of possible implications from the study results are applied
to consult the CSR concept that will be transferred into a business
strategy for the organization manager.
Abstract: To compute dynamic characteristics of nonlinear viscoelastic springs with elastic structures having huge degree-of-freedom, Yamaguchi proposed a new fast numerical method using finite element method [1]-[2]. In this method, restoring forces of the springs are expressed using power series of their elongation. In the expression, nonlinear hysteresis damping is introduced. In this expression, nonlinear complex spring constants are introduced. Finite element for the nonlinear spring having complex coefficients is expressed and is connected to the elastic structures modeled by linear solid finite element. Further, to save computational time, the discrete equations in physical coordinate are transformed into the nonlinear ordinary coupled equations using normal coordinate corresponding to linear natural modes. In this report, the proposed method is applied to simulation for impact responses of a viscoelastic shock absorber with an elastic structure (an S-shaped structure) by colliding with a concentrated mass. The concentrated mass has initial velocities and collides with the shock absorber. Accelerations of the elastic structure and the concentrated mass are measured using Levitation Mass Method proposed by Fujii [3]. The calculated accelerations from the proposed FEM, corresponds to the experimental ones. Moreover, using this method, we also investigate dynamic errors of the S-shaped force transducer due to elastic mode in the S-shaped structure.
Abstract: The proper selection of the AC-side passive filter
interconnecting the voltage source converter to the power supply is
essential to obtain satisfactory performances of an active power filter
system. The use of the LCL-type filter has the advantage of
eliminating the high frequency switching harmonics in the current
injected into the power supply. This paper is mainly focused on
analyzing the influence of the interface filter parameters on the active
filtering performances. Some design aspects are pointed out. Thus,
the design of the AC interface filter starts from transfer functions by
imposing the filter performance which refers to the significant current
attenuation of the switching harmonics without affecting the
harmonics to be compensated. A Matlab/Simulink model of the entire
active filtering system including a concrete nonlinear load has been
developed to examine the system performances. It is shown that a
gamma LC filter could accomplish the attenuation requirement of the
current provided by converter. Moreover, the existence of an optimal
value of the grid-side inductance which minimizes the total harmonic
distortion factor of the power supply current is pointed out.
Nevertheless, a small converter-side inductance and a damping
resistance in series with the filter capacitance are absolutely needed
in order to keep the ripple and oscillations of the current at the
converter side within acceptable limits. The effect of change in the
LCL-filter parameters is evaluated. It is concluded that good active
filtering performances can be achieved with small values of the
capacitance and converter-side inductance.