Abstract: In this paper, the cable model of dendrites have been
considered. The dendrites are cylindrical cables of various segments
having variable length and reducing radius from start point at synapse
and end points. For a particular event signal being received by a
neuron in response only some dendrite are active at a particular
instance. Initial current signals with different current flows in
dendrite are assumed. Due to overlapping and coupling of active
dendrite, they induce currents in the dendrite segments of each other
at a particular instance. But how these currents are induced in the
various segments of active dendrites due to coupling between these
dendrites, It is not presented in the literature. Here the paper presents
a model for induced currents in active dendrite segments due to
mutual coupling at the starting instance of an activity in dendrite. The
model is as discussed further.
Abstract: One of the functions of the commercial heavy vehicle
is to safely and efficiently transport goods and people. Due to its size
and carrying capacity, it is important to study the vehicle dynamic
stability during cornering. Study has shown that there are a number of
overloaded heavy vehicles or permissible Gross Vehicle Weight
(GVW) violations recorded at selected areas in Malaysia assigned by
its type and category. Thus, the objective of this study is to
investigate the correlation and effect of the GVW on heavy vehicle
stability during cornering event using simulation. Various selected
heavy vehicle types and category are simulated using IPG/Truck
Maker® with different GVW and road condition (coefficient of
friction of road surface), while the speed, driver characteristic, center
of gravity of load and road geometry are constant. Based on the
analysis, the relationship between GVW and lateral acceleration were
established. As expected, on the same value of coefficient of friction,
the maximum lateral acceleration would be increased as the GVW
increases.
Abstract: This paper reviews the model-based qualitative and
quantitative Operations Management research in the context of
Construction Supply Chain Management (CSCM). Construction
industry has been traditionally blamed for low productivity, cost and
time overruns, waste, high fragmentation and adversarial
relationships. The construction industry has been slower than other
industries to employ the Supply Chain Management (SCM) concept
and develop models that support the decision-making and planning.
However the last decade there is a distinct shift from a project-based
to a supply-based approach of construction management. CSCM
comes up as a new promising management tool of construction
operations and improves the performance of construction projects in
terms of cost, time and quality. Modeling the Construction Supply
Chain (CSC) offers the means to reap the benefits of SCM, make
informed decisions and gain competitive advantage. Different
modeling approaches and methodologies have been applied in the
multi-disciplinary and heterogeneous research field of CSCM. The
literature review reveals that a considerable percentage of the CSC
modeling research accommodates conceptual or process models
which present general management frameworks and do not relate to
acknowledged soft Operations Research methods. We particularly
focus on the model-based quantitative research and categorize the
CSCM models depending on their scope, objectives, modeling
approach, solution methods and software used. Although over the last
few years there has been clearly an increase of research papers on
quantitative CSC models, we identify that the relevant literature is
very fragmented with limited applications of simulation,
mathematical programming and simulation-based optimization. Most
applications are project-specific or study only parts of the supply
system. Thus, some complex interdependencies within construction
are neglected and the implementation of the integrated supply chain
management is hindered. We conclude this paper by giving future
research directions and emphasizing the need to develop optimization
models for integrated CSCM. We stress that CSC modeling needs a
multi-dimensional, system-wide and long-term perspective. Finally,
prior applications of SCM to other industries have to be taken into
account in order to model CSCs, but not without translating the
generic concepts to the context of construction industry.
Abstract: Hybrid electric vehicles can reduce pollution and
improve fuel economy. Power-split hybrid electric vehicles (HEVs)
provide two power paths between the internal combustion engine
(ICE) and energy storage system (ESS) through the gears of an
electrically variable transmission (EVT). EVT allows ICE to operate
independently from vehicle speed all the time. Therefore, the ICE can
operate in the efficient region of its characteristic brake specific fuel
consumption (BSFC) map. The two-mode powertrain can operate in
input-split or compound-split EVT modes and in four different fixed
gear configurations. Power-split architecture is advantageous because
it combines conventional series and parallel power paths. This
research focuses on input-split and compound-split modes in the
two-mode power-split powertrain. Fuzzy Logic Control (FLC) for an
internal combustion engine (ICE) and PI control for electric machines
(EMs) are derived for the urban driving cycle simulation. These
control algorithms reduce vehicle fuel consumption and improve ICE
efficiency while maintaining the state of charge (SOC) of the energy
storage system in an efficient range.
Abstract: In this study, the pedestrian simulation VISWALK
integration and application platform ant algorithms written program
made to construct a renovation engineering schedule planning mode.
The use of simulation analysis platform construction site when the user
running the simulation, after calculating the user walks in the case of
construction delays, the ant algorithm to find out the minimum delay
time schedule plan, and add volume and unit area deactivated loss of
business computing, and finally to the owners and users of two
different positions cut considerations pick out the best schedule
planning. To assess and validate its effectiveness, this study
constructed the model imported floor of a shopping mall floor
renovation engineering cases. Verify that the case can be found from
the mode of the proposed project schedule planning program can
effectively reduce the delay time and the user's walking mall loss of
business, the impact of the operation on the renovation engineering
facilities in the building to a minimum.
Abstract: This paper investigates simple implicit force control
algorithms realizable with industrial robots. A lot of approaches
already published are difficult to implement in commercial robot
controllers, because the access to the robot joint torques is necessary
or the complete dynamic model of the manipulator is used. In
the past we already deal with explicit force control of a position
controlled robot. Well known schemes of implicit force control are
stiffness control, damping control and impedance control. Using such
algorithms the contact force cannot be set directly. It is further
the result of controller impedance, environment impedance and
the commanded robot motion/position. The relationships of these
properties are worked out in this paper in detail for the chosen
implicit approaches. They have been adapted to be implementable
on a position controlled robot. The behaviors of stiffness control
and damping control are verified by practical experiments. For this
purpose a suitable test bed was configured. Using the full mechanical
impedance within the controller structure will not be practical in the
case when the robot is in physical contact with the environment. This
fact will be verified by simulation.
Abstract: Transportation of long turbine blades from one place
to another is a difficult process. Hence a feasibility study of
modularization of wind turbine blade was taken from structural
standpoint through finite element analysis. Initially, a non-segmented
blade is modeled and its structural behavior is evaluated to serve as
reference. The resonant, static bending and fatigue tests are simulated
in accordance with IEC61400-23 standard for comparison purpose.
The non-segmented test blade is separated at suitable location based
on trade off studies and the segments are joined with an innovative
double strap bonded joint configuration. The adhesive joint is
modeled by adopting cohesive zone modeling approach in ANSYS.
The developed blade model is analyzed for its structural response
through simulation. Performances of both the blades are found to be
similar, which indicates that, efficient segmentation of the long blade
is possible which facilitates easy transportation of the blades and on
site reassembling. The location selected for segmentation and
adopted joint configuration has resulted in an efficient segmented
blade model which proves the methodology adopted for segmentation
was quite effective. The developed segmented blade appears to be the
viable alternative considering its structural response specifically in
fatigue within considered assumptions.
Abstract: The following article presents Technology Centre of
Ostrava (TCO) in the Czech Republic describing the structure and
main research areas realized by the project ENET - Energy Units for
Utilization of non Traditional Energy Sources. More details are
presented from the research program dealing with transformation,
accumulation and distribution of electric energy. Technology Centre
has its own energy mix consisting of alternative sources of fuel
sources that use of process gases from the storage part and also the
energy from distribution network. The article will be focus on the
properties and application possibilities SiC semiconductor devices for
power semiconductor converter for photovoltaic systems.
Abstract: Recently, there is a lot of interest in the field of under
water optical wireless communication for short range because of
its high bandwidth. But in most of the previous works line of
sight propagation or single scattering of photons only considered.
In practical case this is not applicable because of beam blockage in
underwater and multiple scattering also occurred during the photons
propagation through water. In this paper we consider a non-line
of sight underwater wireless optical communication system with
multiple scattering and examine the performance of the system using
monte carlo simulation. The distribution scattering angle of photons
are modeled by Henyey-Greenstein method. The average bit error
rate is calculated using on-off keying modulation for different water
types.
Abstract: The hydrodynamics and heat transfer characteristics
of a vaporized elongated bubble in a rectangular microchannel have
been simulated based on Cahn-Hilliard phase-field method. In the
simulations, the initially nucleated bubble starts growing as it comes
in contact with superheated water. The growing shape of the bubble
compared well with the available experimental data in the literature.
Abstract: Groundwater inflow to the tunnels is one of the most
important problems in tunneling operation. The objective of this
study is the investigation of model dimension effects on tunnel inflow
assessment in discontinuous rock masses using numerical modeling.
In the numerical simulation, the model dimension has an important
role in prediction of water inflow rate. When the model dimension is
very small, due to low distance to the tunnel border, the model
boundary conditions affect the estimated amount of groundwater flow
into the tunnel and results show a very high inflow to tunnel. Hence,
in this study, the two-dimensional universal distinct element code
(UDEC) used and the impact of different model parameters, such as
tunnel radius, joint spacing, horizontal and vertical model domain
extent has been evaluated. Results show that the model domain extent
is a function of the most significant parameters, which are tunnel
radius and joint spacing.
Abstract: In this paper we propose a discrete tracking control of
nonholonomic mobile robots with two degrees of freedom. The
electromechanical model of a mobile robot moving on a horizontal
surface without slipping, with two rear wheels controlled by two
independent DC electric, and one front roal wheel is considered. We
present backstepping design based on the Euler approximate discretetime
model of a continuous-time plant. Theoretical considerations are
verified by numerical simulation.
Abstract: The key role in phenomenological modelling of cyclic
plasticity is good understanding of stress-strain behaviour of given
material. There are many models describing behaviour of materials
using numerous parameters and constants. Combination of individual
parameters in those material models significantly determines whether
observed and predicted results are in compliance. Parameter
identification techniques such as random gradient, genetic algorithm
and sensitivity analysis are used for identification of parameters using
numerical modelling and simulation. In this paper genetic algorithm
and sensitivity analysis are used to study effect of 4 parameters of
modified AbdelKarim-Ohno cyclic plasticity model. Results
predicted by Finite Element (FE) simulation are compared with
experimental data from biaxial ratcheting test with semi-elliptical
loading path.
Abstract: The check-in area of airport terminal is one of the
busiest sections at airports at certain periods. The passengers are
subjected to queues and delays during the check-in process. These
delays and queues are due to constraints in the capacity of service
facilities. In this project, the airport terminal is decomposed into
several check-in areas. The airport check-in scheduling problem
requires both a deterministic (integer programming) and stochastic
(simulation) approach. Integer programming formulations are
provided to minimize the total number of counters in each check-in
area under the realistic constraint that counters for one and the same
flight should be adjacent and the desired number of counters
remaining in each area should be fixed during check-in operations.
By using simulation, the airport system can be modeled to study the
effects of various parameters such as number of passengers on a
flight and check-in counter opening and closing time.
Abstract: The Markov decision process (MDP) based
methodology is implemented in order to establish the optimal
schedule which minimizes the cost. Formulation of MDP problem
is presented using the information about the current state of pipe,
improvement cost, failure cost and pipe deterioration model. The
objective function and detailed algorithm of dynamic programming
(DP) are modified due to the difficulty of implementing the
conventional DP approaches. The optimal schedule derived from
suggested model is compared to several policies via Monte
Carlo simulation. Validity of the solution and improvement in
computational time are proved.
Abstract: Planning of infrastructure and processes in logistic
center within the frame of various kinds of logistic hubs and
technological activities in them represent quite complex problem.
The main goal is to design appropriate layout, which enables to
realize expected operation on the desired levels. The simulation
software represents progressive contemporary experimental
technique, which can support complex processes of infrastructure
planning and all of activities on it. It means that simulation
experiments, reflecting various planned infrastructure variants,
investigate and verify their eligibilities in relation with corresponding
expected operation. The inducted approach enables to make qualified
decisions about infrastructure investments or measures, which derive
benefit from simulation-based verifications. The paper represents
simulation software for simulation infrastructural layout and
technological activities in marshalling yard, intermodal terminal,
warehouse and combination between them as the parts of logistic
center.
Abstract: Total hip replacement had been one of the most
successful operations in hip arthritis surgery. The purpose of this
research had been to develop a dynamic hip contact of Thai femoral
bone to analyze the stress distribution on the implant and the strain
distribution on the bone model under daily activities and compared
with the static load simulation. The results showed the different of
maximum von Mises stress 0.14 percent under walking and 0.03
percent under climbing stair condition and the different of equivalent
total strain 0.52 percent under walking and 0.05 percent under
climbing stair condition. The muscular forces should be evaluated
with dynamic condition to reduce the maximum von Mises stress and
equivalent total strain.
Abstract: This study is used as a definition method to the value
and function in manufacturing sector. In concurrence of discussion
about present condition of modeling method, until now definition of
1D-CAE is ambiguity and not conceptual. Across all the physic fields,
those methods are defined with the formulation of differential
algebraic equation which only applied time derivation and simulation.
At the same time, we propose semi-acausal modeling concept and
differential algebraic equation method as a newly modeling method
which the efficiency has been verified through the comparison of
numerical analysis result between the semi-acausal modeling
calculation and FEM theory calculation.
Abstract: High Peak to Average Power Ratio (PAPR) of the
transmitted signal is a serious problem in multicarrier systems (MC),
such as Orthogonal Frequency Division Multiplexing (OFDM), or in
Multi-Carrier Code Division Multiple Access (MC-CDMA) systems,
due to large number of subcarriers. This effect is possible reduce with
some PAPR reduction techniques. Spreading sequences at the
presence of Saleh and Rapp models of high power amplifier (HPA)
have big influence on the behavior of system. In this paper we
investigate the bit-error-rate (BER) performance of MC-CDMA
systems. Basically we can see from simulations that the MC-CDMA
system with Iterative algorithm can be providing significantly better
results than the MC-CDMA system. The results of our analyses are
verified via simulation.
Abstract: Physics Education Research (PER) results have shown
that students do not achieve the expected level of competency in
understanding the concepts of different domains of Physics learning
when taught by the traditional teaching methods, the concepts of
Electricity and Magnetism (E&M) being one among them.
Simulation being one of the valuable instructional tools renders an
opportunity to visualize varied experiences with such concepts.
Considering the electric force concept which requires extensive use
of vector representations, we report here the outcome of the research
results pertaining to the student understanding of this concept and the
role of simulation in using vector representation. The simulation
platform provides a positive impact on the use of vector
representation.
The first stage of this study involves eliciting and analyzing
student responses to questions that probe their understanding of the
concept of electrostatic force and this is followed by four stages of
student interviews as they use the interactive simulations of electric
force in one dimension. Student responses to the questions are
recorded in real time using electronic pad. A validation test interview
is conducted to evaluate students' understanding of the electric force
concept after using interactive simulation. Results indicate lack of
procedural knowledge of the vector representation. The study
emphasizes the need for the choice of appropriate simulation and
mode of induction for learning.