Abstract: The implicit block methods based on the backward
differentiation formulae (BDF) for the solution of stiff initial value
problems (IVPs) using variable step size is derived. We construct a
variable step size block methods which will store all the coefficients
of the method with a simplified strategy in controlling the step size
with the intention of optimizing the performance in terms of
precision and computation time. The strategy involves constant,
halving or increasing the step size by 1.9 times the previous step size.
Decision of changing the step size is determined by the local
truncation error (LTE). Numerical results are provided to support the
enhancement of method applied.
Abstract: The presence of a vertical fatigue crack in the web of
a plate girder subjected to pure bending influences the bending
moment capacity of the girder. The growth of the crack may lead to
premature elastic failure due to flange local yielding, flange local
buckling, or web local buckling. Approximate expressions for the
bending moment capacities corresponding to these failure modes
were formulated. Finite element analyses were then used to validate
the expressions. The expressions were employed to assess the effects
of crack length on the capacity. Neglecting brittle fracture, tension
buckling, and ductile failure modes, it was found that typical girders
are governed by the capacity associated with flange local yielding as
influenced by the crack. Concluding, a possible use of the capacity
expressions in girder design was demonstrated.
Abstract: This paper tests the level of market integration between Malaysia and Singapore stock markets with the world market. Kalman Filter (KF) methodology is used on the International Capital Asset Pricing Model (ICAPM) and the pricing errors estimated within the framework of ICAPM are used as a measure of market integration or segmentation. The advantage of the KF technique is that it allows for time-varying coefficients in estimating ICAPM and hence able to capture the varying degree of market integration. Empirical results show clear evidence of varying degree of market integration for both case of Malaysia and Singapore. Furthermore, the results show that the changes in the level of market integration are found to coincide with certain economic events that have taken placed. The findings certainly provide evidence on the practicability of the KF technique to estimate stock markets integration. In the comparison between Malaysia and Singapore stock market, the result shows that the trends of the market integration indices for Malaysia and Singapore look similar through time but the magnitude is notably different with the Malaysia stock market showing greater degree of market integration. Finally, significant evidence of varying degree of market integration shows the inappropriate use of OLS in estimating the level of market integration.
Abstract: The Norwegian Military Academy (Army) has
initiated a project with the main ambition to explore possible avenues
to enhancing operational effectiveness through an increased use of
simulation-based training and exercises. Within a cost/benefit
framework, we discuss opportunities and limitations of vertical and
horizontal integration of the existing tactical training system. Vertical
integration implies expanding the existing training system to span the
full range of training from tactical level (platoon, company) to
command and staff level (battalion, brigade). Horizontal integration
means including other domains than army tactics and staff
procedures in the training, such as military ethics, foreign languages,
leadership and decision making. We discuss each of the integration
options with respect to purpose and content of training, "best
practice" for organising and conducting simulation-based training,
and suggest how to evaluate training procedures and measure
learning outcomes. We conclude by giving guidelines towards further
explorative work and possible implementation.
Abstract: Shrunken patterning for integrated device
manufacturing requires surface cleanliness and surface smoothness in
wet chemical processing [1]. It is necessary to control all process
parameters perfectly especially for the common cleaning technique
RCA clean (SC-1 and SC-2) [2]. In this paper the characteristic and
effect of surface preparation parameters are discussed. The properties
of RCA wet chemical processing in silicon technology is based on
processing time, temperature, concentration and megasonic power of
SC-1 and QDR. An improvement of wafer surface preparation by
the enhanced variables of the wet cleaning chemical process is
proposed.
Abstract: In present work are considered the scheme of
evaluation the transition probability in quantum system. It is based on
path integral representation of transition probability amplitude and its
evaluation by means of a saddle point method, applied to the part of
integration variables. The whole integration process is reduced to
initial value problem solutions of Hamilton equations with a random
initial phase point. The scheme is related to the semiclassical initial
value representation approaches using great number of trajectories. In
contrast to them from total set of generated phase paths only one path
for each initial coordinate value is selected in Monte Karlo process.
Abstract: In the current study, we have conducted an experimental investigation on the utilization of electronic arc furnace (EAF) reducing slag for the absorption of CO2 via wet grinding method. It was carried out by various grinding conditions. The slag was ground in the vibrating ball mill in the presence of CO2 and pure water under ambient temperature. The reaction behavior was monitored with constant pressure method, and the changes of experimental systems volume as a function of grinding time were measured. It was found that the CO2 absorption occurred as soon as the grinding started. The CO2 absorption was significantly increased in the case of wet grinding compare to the dry grinding. Generally, the amount of CO2 absorption increased as the amount of water, weight of slag and initial pressure increased. However, it was decreased when the amount of water exceeds 200ml and when smaller balls were used. The absorption of CO2 occurred simultaneously with the start of the grinding and it stopped when the grinding was stopped. According to this research, the CO2 reacted with the CaO inside the slag, forming CaCO3.
Abstract: This paper provides an exergy analysis of the multistage refrigeration cycle used for C2+ recovery plant. The behavior of an industrial refrigeration cycle with refrigerant propane has been investigated by the exergy method. A computational model based on the exergy analysis is presented for the investigation of the effects of the valves on the exergy losses, the second law of efficiency, and the coefficient of performance (COP) of a vapor compression refrigeration cycle. The equations of exergy destruction and exergetic efficiency for the main cycle components such as evaporators, condensers, compressors, and expansion valves are developed. The relations for the total exergy destruction in the cycle and the cycle exergetic efficiency are obtained. An ethane recovery unit with its refrigeration cycle has been simulated to prepare the exergy analysis. Using a typical actual work input value; the exergetic efficiency of the refrigeration cycle is determined to be 39.90% indicating a great potential for improvements. The simulation results reveal that the exergetic efficiencies of the heat exchanger and expansion sections get the lowest rank among the other compartments of refrigeration cycle. Refrigeration calculations have been carried out through the analysis of T–S and P–H diagrams where coefficient of performance (COP) was obtained as 1.85. The novelty of this article includes the effect and sensitivity analysis of molar flow, pressure drops and temperature on the exergy efficiency and coefficient of performance of the cycle.
Abstract: In determining the electromagnetic properties of
magnetic materials, hysteresis modeling is of high importance. Many
models are available to investigate those characteristics but they tend
to be complex and difficult to implement. In this paper a new
qualitative hysteresis model for ferromagnetic core is presented,
based on the function approximation capabilities of adaptive neuro
fuzzy inference system (ANFIS). The proposed ANFIS model
combined the neural network adaptive capabilities and the fuzzy
logic qualitative approach can restored the hysteresis curve with a
little RMS error. The model accuracy is good and can be easily
adapted to the requirements of the application by extending or
reducing the network training set and thus the required amount of
measurement data.
Abstract: This paper describes the development of a WLAN
propagation model, using Spectral Analyzer measurements. The
signal is generated by two Access Points (APs) on the base floor at
the administrative Communication School of ESPOL building. In
general, users do not have a Q&S reference about a wireless network;
however, this depends on the level signal as a function of frequency,
distance and other path conditions between receiver and transmitter.
Then, power density of the signal decrease as it propagates through
space and data transfer rate is affected. This document evaluates and
implements empirical mathematical formulation for the
characterization of WLAN radio wave propagation on two aisles of
the building base floor.
Abstract: This paper describes a novel and effective approach to content-based image retrieval (CBIR) that represents each image in the database by a vector of feature values called “Standard deviation of mean vectors of color distribution of rows and columns of images for CBIR". In many areas of commerce, government, academia, and hospitals, large collections of digital images are being created. This paper describes the approach that uses contents as feature vector for retrieval of similar images. There are several classes of features that are used to specify queries: colour, texture, shape, spatial layout. Colour features are often easily obtained directly from the pixel intensities. In this paper feature extraction is done for the texture descriptor that is 'variance' and 'Variance of Variances'. First standard deviation of each row and column mean is calculated for R, G, and B planes. These six values are obtained for one image which acts as a feature vector. Secondly we calculate variance of the row and column of R, G and B planes of an image. Then six standard deviations of these variance sequences are calculated to form a feature vector of dimension six. We applied our approach to a database of 300 BMP images. We have determined the capability of automatic indexing by analyzing image content: color and texture as features and by applying a similarity measure Euclidean distance.
Abstract: Today-s economy is in a permanent change, causing
merger and acquisitions and co operations between enterprises. As a
consequence, process adaptations and realignments result in systems
integration and software development projects. Processes and
procedures to execute such projects are still reliant on craftsman-ship
of highly skilled workers. A generally accepted, industrialized
production, characterized by high efficiency and quality, seems
inevitable.
In spite of this, current concepts of software industrialization are
aimed at traditional software engineering and do not consider the
characteristics of systems integration. The present work points out
these particularities and discusses the applicability of existing
industrial concepts in the systems integration domain. Consequently
it defines further areas of research necessary to bring the field of
systems integration closer to an industrialized production, allowing a
higher efficiency, quality and return on investment.
Abstract: In the present paper; an experimental and numerical
investigations of drag reduction on a grooved circular cylinder have
been performed. The experiments were carried out in closed circuit
subsonic wind tunnel (TE44); the pressure distribution on the
cylinder was conducted using a TE44DPS differential pressure
scanner and the drag forces were measured using the TE81 balance.
The display unit is linked to a computer, loaded with DATASLIM
software for data analysis and logging of result. The numerical study
was performed using the code ANSYS FLUENT solving the
Reynolds Averaged Navier-Stokes (RANS) equations. The k-ε and k-
ω SST models were tested. The results obtained from the
experimental and numerical investigations have showed a reduction
in the drag when using longitudinal grooves namely 2 and 6 on the
cylinder.
Abstract: The article examines the methods of protection of
citizens' personal data on the Internet using biometric identity
authentication technology. It`s celebrated their potential danger due
to the threat of loss of base biometric templates. To eliminate the
threat of compromised biometric templates is proposed to use neural
networks large and extra-large sizes, which will on the one hand
securely (Highly reliable) to authenticate a person by his biometrics,
and on the other hand make biometrics a person is not available for
observation and understanding. This article also describes in detail
the transformation of personal biometric data access code. It`s formed
the requirements for biometrics converter code for his work with the
images of "Insider," "Stranger", all the "Strangers". It`s analyzed the
effect of the dimension of neural networks on the quality of
converters mystery of biometrics in access code.
Abstract: This paper considers the integration of assembly
operations and product structure to Cellular Manufacturing System
(CMS) design so that to correct the drawbacks of previous researches
in the literature. For this purpose, a new mathematical model is
developed which dedicates machining and assembly operations to
manufacturing cells while the objective function is to minimize the
intercellular movements resulting due to both of them. A
linearization method is applied to achieve optimum solution through
solving aforementioned nonlinear model by common programming
language such as Lingo. Then, using different examples and
comparing the results, the importance of integrating assembly
considerations is demonstrated.
Abstract: An epidemiological cross sectional study was
undertaken in Yaoundé in 2002 and updated in 2005. Focused on
health within the city, the objectives were to measure diarrheal
prevalence and to identify the risk factors associated with them.
Results of microbiological examinations have revealed an urban
average prevalence rate of 14.5%. Access to basic services in the
living environment appears to be an important risk factor for
diarrheas. Statistical and spatial analyses conducted have revealed
that prevalence of diarrheal diseases vary among the two main types
of settlement (informal and planned). More importantly, this study
shows that, diarrhea prevalence rates (notably bacterial and parasitic
diarrheas) vary according to the sub- category of settlements. The
study draws a number of theoretical and policy implications for
researchers and policy decision makers.
Abstract: In an effort to understand the preliminary effects of aerodynamic stress on alveolar epithelial cells, we developed a multifluidic cell culture platform capable of supporting alveolar cultures at an air-liquid interface under constant air flow and exposure to varying pressure stimuli on the apical side while providing nourishment on the basolateral plane. Our current study involved utilizing the platform to study the effect of basement membrane coating and addition of dexamethasone on cellular response to pressure in A549 and H441 alveolar epithelial cells.
Abstract: The purpose of the present study is the investigation
of the relationship between knowledge management and enabling
managers based on achieving proper function. This research is
descriptive and investigative. The sample includes all male and
female high school managers of first and second regions of Urmia
including 98 school and accordingly 98 managers. The instrument
applied was a questionnaire. To sum up, there is a statistically
significant relationship between knowledge management and
empowering managers. In the end, several suggestions are provided.
Abstract: A semi-active control strategy for suspension
systems of passenger cars is presented employing
Magnetorheological (MR) dampers. The vehicle is modeled with
seven DOFs including the, roll pitch and bounce of car body, and
the vertical motion of the four tires. In order to design an optimal
controller based on the actuator constraints, a Linear-Quadratic
Regulator (LQR) is designed. The design procedure of the LQR
consists of selecting two weighting matrices to minimize the energy
of the control system. This paper presents a hybrid optimization
procedure which is a combination of gradient-based and
evolutionary algorithms to choose the weighting matrices with
regards to the actuator constraint. The optimization algorithm is
defined based on maximum comfort and actuator constraints. It is
noted that utilizing the present control algorithm may significantly
reduce the vibration response of the passenger car, thus, providing
a comfortable ride.
Abstract: In this project, a tele-operated anthropomorphic
robotic arm and hand is designed and built as a versatile robotic arm
system. The robot has the ability to manipulate objects such as pick
and place operations. It is also able to function by itself, in
standalone mode.
Firstly, the robotic arm is built in order to interface with a personal
computer via a serial servo controller circuit board. The circuit board
enables user to completely control the robotic arm and moreover,
enables feedbacks from user. The control circuit board uses a
powerful integrated microcontroller, a PIC (Programmable Interface
Controller). The PIC is firstly programmed using BASIC (Beginner-s
All-purpose Symbolic Instruction Code) and it is used as the 'brain'
of the robot. In addition a user friendly Graphical User Interface
(GUI) is developed as the serial servo interface software using
Microsoft-s Visual Basic 6.
The second part of the project is to use speech recognition control
on the robotic arm. A speech recognition circuit board is constructed
with onboard components such as PIC and other integrated circuits. It
replaces the computers- Graphical User Interface. The robotic arm is
able to receive instructions as spoken commands through a
microphone and perform operations with respect to the commands
such as picking and placing operations.