Abstract: In the present study, the oleaginous fungus
Mortierella alpina CBS 754.68 was screened for arachidonic
acidproduction using inexpensive agricultural by-products as
substrate. Four oilcakes were analysed to choose the best substrate
among them. Sunflower oilcake was the most effective substrate for
ARA production followed by soybean, colza and olive oilcakes. In
the next step, seven variables including substrate particle size,
moisture content, time, temperature, yeast extract supply, glucose
supply and glutamate supply were surveyed and effective variables
for ARA production were determined using a Plackett-Burman
screening design. Analysis results showed that time (12 days),
substrate particle size (1-1.4 mm) and temperature (20ºC) were the
most effective variables for the highest level of ARA production
respectively.
Abstract: This paper presents an analytical method to solve
governing consolidation parabolic partial differential equation (PDE)
for inelastic porous Medium (soil) with consideration of variation of
equation coefficient under cyclic loading. Since under cyclic loads,
soil skeleton parameters change, this would introduce variable
coefficient of parabolic PDE. Classical theory would not rationalize
consolidation phenomenon in such condition. In this research, a
method based on time space mapping to a virtual time space along
with superimposing rule is employed to solve consolidation of
inelastic soils in cyclic condition. Changes of consolidation
coefficient applied in solution by modification of loading and
unloading duration by introducing virtual time. Mapping function is
calculated based on consolidation partial differential equation results.
Based on superimposing rule a set of continuous static loads in
specified times used instead of cyclic load. A set of laboratory
consolidation tests under cyclic load along with numerical
calculations were performed in order to verify the presented method.
Numerical solution and laboratory tests results showed accuracy of
presented method.
Abstract: Riprap is mostly used to prevent erosion by flows
down the steep slopes in river engineering. A total of 53 stability tests
performed on angular riprap with a median stone size ranging from
15 to 278 mm and slope ranging from 1 to 40% are used in this study.
The existing equations for the prediction of medium size of angular
stones are checked for their accuracy using the available data.
Predictions of median size using these equations are not satisfactory
and results show deviation by more than ±20% from the observed
values. A multivariable power regression analysis is performed to
propose a new equation relating the median size with unit discharge,
bed slope, riprap thickness and coefficient of uniformity. The
proposed relationship satisfactorily predicts the median angular stone
size with ±20% error. Further, the required size of the rounded stone
is more than the angular stone for the same unit discharge and the
ratio increases with unit discharge and also with embankment slope
of the riprap.
Abstract: The purposes of this research were 1) to study
consumer-based equity of luxury brands, 2) to study consumers-
purchase intention for luxury brands, 3) to study direct factors
affecting purchase intention towards luxury brands, and 4) to study
indirect factors affecting purchase intention towards luxury brands
through brand consciousness and brand equity to analyze information
by descriptive statistic and hierarchical stepwise regression analysis.
The findings revealed that the eight variables of the framework which
were: need for uniqueness, normative susceptibility, status
consumption, brand consciousness, brand awareness, perceived
quality, brand association, and brand loyalty affected the purchase
intention of the luxury brands (at the significance of 0.05). Brand
Loyalty had the strongest direct effect while status consumption had
the strongest indirect effect affecting the purchase intention towards
luxury brands. Brand consciousness and brand equity had the
mediators through the purchase intention of the luxury brands (at the
significance of 0.05).
Abstract: The purpose of this paper primarily intends to develop GIS interface for estimating sequences of stream-flows at ungauged stations based on known flows at gauged stations. The integrated GIS interface is composed of three major steps. The first, precipitation characteristics using statistical analysis is the procedure for making multiple linear regression equation to get the long term mean daily flow at ungauged stations. The independent variables in regression equation are mean daily flow and drainage area. Traditionally, mean flow data are generated by using Thissen polygon method. However, method for obtaining mean flow data can be selected by user such as Kriging, IDW (Inverse Distance Weighted), Spline methods as well as other traditional methods. At the second, flow duration curve (FDC) is computing at unguaged station by FDCs in gauged stations. Finally, the mean annual daily flow is computed by spatial interpolation algorithm. The third step is to obtain watershed/topographic characteristics. They are the most important factors which govern stream-flows. In summary, the simulated daily flow time series are compared with observed times series. The results using integrated GIS interface are closely similar and are well fitted each other. Also, the relationship between the topographic/watershed characteristics and stream flow time series is highly correlated.
Abstract: The role of corporate governance is to reduce the
divergence of interests between shareholders and managers. The role
of corporate governance is more useful when managers have an
incentive to deviate from shareholders- interests. One example of
management-s deviation from shareholders- interests is the
management of earnings through the use of accounting accruals. This
paper examines the association between corporate governance
internal mechanisms ownership concentration, board independence,
the existence of CEO-Chairman duality and earnings management.
Firm size and leverage are control variables. The population used in
this study comprises firms listed on the Tehran Stock Exchange
(TSE) between 2004 and 2008, the sample comprises 196 firms.
Panel Data method is employed as technique to estimate the model.
We find that there is negative significant association between
ownership concentration and board independence manage earnings
with earnings management, there is negative significant association
between the existence of CEO-Chairman duality and earnings
management. This study also found a positive significant association
between control variable (firm size and leverage) and earnings
management.
Abstract: In this paper, a novel approach for robust trajectory tracking of induction motor drive is presented. By combining variable structure systems theory with fuzzy logic concept and neural network techniques, a new algorithm is developed. Fuzzy logic was used for the adaptation of the learning algorithm to improve the robustness of learning and operating of the neural network. The developed control algorithm is robust to parameter variations and external influences. It also assures precise trajectory tracking with the prescribed dynamics. The algorithm was verified by simulation and the results obtained demonstrate the effectiveness of the designed controller of induction motor drives which considered as highly non linear dynamic complex systems and variable characteristics over the operating conditions.
Abstract: The purpose of this paper is to provide a practical
example to the Linear Quadratic Gaussian (LQG) controller. This
method includes a description and some discussion of the discrete
Kalman state estimator. One aspect of this optimality is that the
estimator incorporates all information that can be provided to it. It
processes all available measurements, regardless of their precision, to
estimate the current value of the variables of interest, with use of
knowledge of the system and measurement device dynamics, the
statistical description of the system noises, measurement errors, and
uncertainty in the dynamics models.
Since the time of its introduction, the Kalman filter has been the
subject of extensive research and application, particularly in the area
of autonomous or assisted navigation. For example, to determine the
velocity of an aircraft or sideslip angle, one could use a Doppler
radar, the velocity indications of an inertial navigation system, or the
relative wind information in the air data system. Rather than ignore
any of these outputs, a Kalman filter could be built to combine all of
this data and knowledge of the various systems- dynamics to
generate an overall best estimate of velocity and sideslip angle.
Abstract: Combining energy efficiency with renewable energy
sources constitutes a key strategy for a sustainable future. The wind
power sector stands out as a fundamental element for the
achievement of the European renewable objectives and Portugal is no
exception to the increase of the wind energy for the electricity
generation. This work proposes an optimization model for the long
range electricity power planning in a system similar to the
Portuguese one, where the expected impacts of the increasing
installed wind power on the operating performance of thermal power
plants are taken into account. The main results indicate that the
increasing penetration of wind power in the electricity system will
have significant effects on the combined cycle gas power plants
operation and on the theoretically expected cost reduction and
environmental gains. This research demonstrated the need to address
the impact that energy sources with variable output may have, not
only on the short-term operational planning, but especially on the
medium to long range planning activities, in order to meet the
strategic objectives for the energy sector.
Abstract: This study investigated possible ways to improve the
efficiency of the platinum precipitation process using ammonium
chloride by reducing the platinum content reporting to the effluent.
The ore treated consist of five platinum group metals namely,
ruthenium, rhodium, iridium, platinum, palladium and a precious
metal gold. Gold, ruthenium, rhodium and iridium were extracted
prior the platinum precipitation process. Temperature, reducing
agent, flow rate and potential difference were the variables controlled
to determine the operation conditions for optimum platinum
precipitation efficiency. Hydrogen peroxide was added as the
oxidizing agent at the temperature of 85-90oC and potential
difference of 700-850mV was the variable used to check the
oxidizing state of platinum. The platinum was further purified at
temperature between 60-65oC, potential difference above 700 mV,
ammonium chloride of 200 l, and at these conditions the platinum
content reporting to the effluent was reduced to less than 300ppm,
resulting in optimum platinum precipitation efficiency and purity of
99.9%.
Abstract: This paper presents the design, development and characterization of contractile water jet thruster (CWJT) for mini underwater robot. Instead of electric motor, this CWJT utilizes the Ionic Polymer Metal Composite (IPMC) as the actuator to generate the water jet. The main focus of this paper is to analyze the conceptual design of the proposed CWJT which would determine the thrust force value, jet flow behavior and actuator’s stress. Those thrust force and jet flow studies were carried out using Matlab/Simscape simulation software. The actuator stress had been analyzed using COSMOS simulation software. The results showed that there was no significant change for jet velocity at variable cross sectional nozzle area. However, a significant change was detected for jet velocity at different nozzle cross sectional area ratio which was up to 37%. The generated thrust force has proportional relation to the nozzle cross sectional area.
Abstract: The quality improvements of the environmental
elements could increase the recreational opportunities in a certain
area (destination). The technique of the need for recreation focuses
on choosing certain destinations for recreational purposes. The basic
exchange taken into consideration is the one between the satisfaction
gained after staying in that area and the value expressed in money
and time allocated. The number of tourists in the respective area, the
duration of staying and the money spent including transportation
provide information on how individuals rank the place or certain
aspects of the area (such as the quality of the environmental
elements).
For the statistical analysis of the environmental benefits offered by
an area through the need of recreation technique, the following stages
are suggested:
- characterization of the reference area based on the
statistical variables considered;
- estimation of the environmental benefit through
comparing the reference area with other similar areas
(having the same environmental characteristics), from
the perspective of the statistical variables considered.
The model compared in recreation technique faced with a series of
difficulties which refers to the reference area and correct
transformation of time in money.
Abstract: The understanding of knee movement during swing
importance for golf swing improving and preventing injury. Thirty
male professional and amateur golfers were assigned to swing time
by time for 3 times. Data from a vedio-based motion capture were
used to compute knee joint movement variables. The results showed
that professional and amateur golfers were significantly in left knee
flexion angle at the impact point and mid follow through phase.
Nevertheless, left knee external rotation in both groups was also
significant. The right knee were no significant different in all
variable. However, pattern of knee joint movement are also likely
between professional and amateur golfers.
Abstract: recurrent neural network (RNN) is an efficient tool for
modeling production control process as well as modeling services. In
this paper one RNN was combined with regression model and were
employed in order to be checked whether the obtained data by the
model in comparison with actual data, are valid for variable process
control chart. Therefore, one maintenance process in workshop of
Esfahan Oil Refining Co. (EORC) was taken for illustration of
models. First, the regression was made for predicting the response
time of process based upon determined factors, and then the error
between actual and predicted response time as output and also the
same factors as input were used in RNN. Finally, according to
predicted data from combined model, it is scrutinized for test values
in statistical process control whether forecasting efficiency is
acceptable. Meanwhile, in training process of RNN, design of
experiments was set so as to optimize the RNN.
Abstract: In this paper, we investigate dynamics of 2n almost periodic attractors for Cohen-Grossberg neural networks (CGNNs) with variable and distribute time delays. By imposing some new assumptions on activation functions and system parameters, we split invariant basin of CGNNs into 2n compact convex subsets. Then the existence of 2n almost periodic solutions lying in compact convex subsets is attained due to employment of the theory of exponential dichotomy and Schauder-s fixed point theorem. Meanwhile, we derive some new criteria for the networks to converge toward these 2n almost periodic solutions and exponential attracting domains are also given correspondingly.
Abstract: This research is to explore the satisfaction for senior
citizens on continuing education in Taiwan. The purpose of this
research aims at the difference on teacher-s teaching, personal
relationship, learning result, materials and environment. Through
different sexual and living area as the background variables, a
questionnaire is adopted as the methodology in this research. Three
results are found in this research. In overall, senior citizens taking
continuing education put the most important attention on personal
relationship but materials and leaning environment put the least. There
is a significant difference on personal relationship, teacher-s teaching
and research result between different sexes. Female senior citizens
attach more importance to teacher-s teaching and learning results but
male senior citizens value on personal relationship. Another
significant difference is shown on teacher-s teaching and personal
relationship because of senior citizens living area. Urban senior
citizens put importance on personal relationship and rural senior
citizens respect teacher-s teaching more.
Abstract: The actual grow of the infrastructure in develop country require sophisticate ways manage the operation and control the quality served. This research wants to concentrate in the operation of this infrastructure beyond the construction. The infrastructure-s operation involves an uncertain environment, where unexpected variables are present every day and everywhere. Decision makers need to make right decisions with right information/data analyzed most in real time. To adequately support their decisions and decrease any negative impact and collateral effect, they need to use computational tools called decision support systems (DSS), but now the main source of information came from common users thought an extensive crowdsourcing
Abstract: In this paper a special kind of buffer management policy is studied where the packet are preempted even when sufficient space is available in the buffer for incoming packets. This is done to congestion for future incoming packets to improve QoS for certain type of packets. This type of study has been done in past for ATM type of scenario. We extend the same for heterogeneous traffic where data rate and size of the packets are very versatile in nature. Typical example of this scenario is the buffer management in Differentiated Service Router. There are two aspects that are of interest. First is the packet size: whether all packets have same or different sizes. Second aspect is the value or space priority of the packets, do all packets have the same space priority or different packets have different space priorities. We present two types of policies to achieve QoS goals for packets with different priorities: the push out scheme and the expelling scheme. For this work the scenario of packets of variable length is considered with two space priorities and main goal is to minimize the total weighted packet loss. Simulation and analytical studies show that, expelling policies can outperform the push out policies when it comes to offering variable QoS for packets of two different priorities and expelling policies also help improve the amount of admissible load. Some other comparisons of push out and expelling policies are also presented using simulations.
Abstract: Variable digital filters are useful for various signal processing and communication applications where the frequency characteristics, such as fractional delays and cutoff frequencies, can be varied. In this paper, we propose a design method of variable FIR digital filters with an approximate linear phase characteristic in the passband. The proposed variable FIR filters have some large attenuation in stopband and their large attenuation can be varied by spectrum parameters. In the proposed design method, a quasi-equiripple characteristic can be obtained by using an iterative weighted least square method. The usefulness of the proposed design method is verified through some examples.
Abstract: It-s known that incorporating prior knowledge into support
vector regression (SVR) can help to improve the approximation
performance. Most of researches are concerned with the incorporation
of knowledge in form of numerical relationships. Little work,
however, has been done to incorporate the prior knowledge on the
structural relationships among the variables (referred as to Structural
Prior Knowledge, SPK). This paper explores the incorporation of SPK
in SVR by constructing appropriate admissible support vector kernel
(SV kernel) based on the properties of reproducing kernel (R.K).
Three-levels specifications of SPK are studies with the corresponding
sub-levels of prior knowledge that can be considered for the method.
These include Hierarchical SPK (HSPK), Interactional SPK (ISPK)
consisting of independence, global and local interaction, Functional
SPK (FSPK) composed of exterior-FSPK and interior-FSPK. A
convenient tool for describing the SPK, namely Description Matrix
of SPK is introduced. Subsequently, a new SVR, namely Motivated
Support Vector Regression (MSVR) whose structure is motivated
in part by SPK, is proposed. Synthetic examples show that it is
possible to incorporate a wide variety of SPK and helpful to improve
the approximation performance in complex cases. The benefits of
MSVR are finally shown on a real-life military application, Air-toground
battle simulation, which shows great potential for MSVR to
the complex military applications.