Abstract: In this paper cognitive radio is presented and the
spectrum overlay cognitive radio antenna system is detailed. A UWB
antenna with frequency reconfigurable characteristics is proposed.
The reconfigurability is achieved when the filter is integrated to the
feeding line of the single port overlay cognitive radio. When
activated, the filter can transform the UWB frequency response into a
reconfigurable narrowband one, which is suitable for the
communication operation of the CR system. Here single port overlay
cognitive radio antenna is designed and simulated using Ansoft High
Frequency Structure Simulator (HFSS).
Abstract: There is decagram of strategic decisions of operations
and production/service management (POSM) within operational
research (OR) which must collate, namely: design, inventory, quality,
location, process and capacity, layout, scheduling, maintain ace, and
supply chain. This paper presents an architectural configuration
conceptual framework of a decagram of sets decisions in a form of
mathematical complete graph and abelian graph.
Mathematically, a complete graph is undirected (UDG), and
directed (DG) a relationship where every pair of vertices is
connected, collated, confluent, and holomorphic.
There has not been any study conducted which, however,
prioritizes the holomorphic sets which of POMS within OR field of
study. The study utilizes OR structured technique known as The
Analytic Hierarchy Process (AHP) analysis for organizing, sorting
and prioritizing(ranking) the sets within the decagram of POMS
according to their attribution (propensity), and provides an analysis
how the prioritization has real-world application within the 21st
century.
Abstract: In this study, the performance analyses of the twenty
five Coal-Fired Power Plants (CFPPs) used for electricity generation
are carried out through various Data Envelopment Analysis (DEA)
models. Three efficiency indices are defined and pursued. During the
calculation of the operational performance, energy and non-energy
variables are used as input, and net electricity produced is used as
desired output (Model-1). CO2 emitted to the environment is used as
the undesired output (Model-2) in the computation of the pure
environmental performance while in Model-3 CO2 emissions is
considered as detrimental input in the calculation of operational and
environmental performance. Empirical results show that most of the
plants are operating in increasing returns to scale region and Mettur
plant is efficient one with regards to energy use and environment.
The result also indicates that the undesirable output effect is
insignificant in the research sample. The present study will provide
clues to plant operators towards raising the operational and
environmental performance of CFPPs.
Abstract: One of the major difficulties introduced with wind
power penetration is the inherent uncertainty in production originating
from uncertain wind conditions. This uncertainty impacts many
different aspects of power system operation, especially the balancing
power requirements. For this reason, in power system development
planing, it is necessary to evaluate the potential uncertainty in future
wind power generation. For this purpose, simulation models are
required, reproducing the performance of wind power forecasts.
This paper presents a wind power forecast error simulation models
which are based on the stochastic process simulation. Proposed
models capture the most important statistical parameters recognized
in wind power forecast error time series. Furthermore, two distinct
models are presented based on data availability. First model uses
wind speed measurements on potential or existing wind power plant
locations, while the seconds model uses statistical distribution of wind
speeds.
Abstract: The Simulation based VLSI Implementation of
FELICS (Fast Efficient Lossless Image Compression System)
Algorithm is proposed to provide the lossless image compression and
is implemented in simulation oriented VLSI (Very Large Scale
Integrated). To analysis the performance of Lossless image
compression and to reduce the image without losing image quality
and then implemented in VLSI based FELICS algorithm. In FELICS
algorithm, which consists of simplified adjusted binary code for
Image compression and these compression image is converted in
pixel and then implemented in VLSI domain. This parameter is used
to achieve high processing speed and minimize the area and power.
The simplified adjusted binary code reduces the number of arithmetic
operation and achieved high processing speed. The color difference
preprocessing is also proposed to improve coding efficiency with
simple arithmetic operation. Although VLSI based FELICS
Algorithm provides effective solution for hardware architecture
design for regular pipelining data flow parallelism with four stages.
With two level parallelisms, consecutive pixels can be classified into
even and odd samples and the individual hardware engine is
dedicated for each one. This method can be further enhanced by
multilevel parallelisms.
Abstract: In previous study, technique to estimate a self-location by using a lunar image is proposed.We consider the improvement of the conventional method in consideration of FPGA implementationin this paper. Specifically, we introduce Artificial Bee Colony algorithm for reduction of search time.In addition, we use fixed point arithmetic to enable high-speed operation on FPGA.
Abstract: The most important component affecting the
efficiency of photovoltaic power systems are solar panels. In other
words, efficiency of these systems are significantly affected due to
the being low efficiency of solar panel. Thus, solar panels should be
operated under maximum power point conditions through a power
converter. In this study, design of boost converter has been carried
out with maximum power point tracking (MPPT) algorithm which is
incremental conductance (Inc-Cond). By using this algorithm,
importance of power converter in MPPT hardware design, impacts of
MPPT operation have been shown. It is worth noting that initial
operation point is the main criteria for determining the MPPT
performance. In addition, it is shown that if value of load resistance is
lower than critical value, failure operation is realized. For these
analyzes, direct duty control is used for simplifying the control.
Abstract: Given the importance of ports as links in the global
supply chains and because they are key elements to induce
competitiveness in their hinterlands, the number of studies devoted to
port governance, management and operations has increased in the last
decades. Some of these studies address the port governance model as
an element to improve coordination among the actors of the portlogistics
chain and to generate a better port performance. In this
context, the present study analyzes the governance of Port of Santos
through individual interviews with port managers, based on a
conceptual model that considers the key dimensions associated with
port governance. The results reinforce the usefulness of the applied
model and highlight some existing improvement opportunities in the
port studied.
Abstract: Operations research science (OR) deals with good
success in developing and applying scientific methods for problem
solving and decision-making. However, by using OR techniques, we
can enhance the use of computer decision support systems to achieve
optimal management for institutions. OR applies comprehensive
analysis including all factors that effect on it and builds mathematical
modeling to solve business or organizational problems. In addition, it
improves decision-making and uses available resources efficiently.
The adoption of OR by universities would definitely contributes to
the development and enhancement of the performance of OR
techniques. This paper provides an understanding of the structures,
approaches and models of OR in problem solving and decisionmaking.
Abstract: e-Service has moved from the usual manual and
traditional way of rendering services to electronic service provision
for the public and there are several reasons for implementing these
services, Airline ticketing have gone from its manual traditional way
to an intelligent web-driven service of purchasing. Many companies
have seen their profits doubled through the use of online services in
their operation and a typical example is Hewlett Packard (HP) which
is rapidly transforming their after sales business into a profit
generating e-service business unit.
This paper will examine the various challenges confronting e-
Service adoption and implementation in Nigeria and also analyse
lessons learnt from e-Service adoption and implementation in Asia to
see how it could be useful in Nigeria which is a lower middle income
country. From the analysis of the online survey data, it has been
identified that the public in Nigeria are much aware of e-Services but
successful adoption and implementation have been the problems
faced.
Abstract: Over the last few decades, oilfield service rolling
equipment has significantly increased in weight, primarily because of
emissions regulations, which require larger/heavier engines, larger
cooling systems, and emissions after-treatment systems, in some
cases, etc. Larger engines cause more vibration and shock loads,
leading to failure of electronics and control systems.
If the vibrating frequency of the engine matches the system
frequency, high resonance is observed on structural parts and mounts.
One such existing automated control equipment system comprising
wire rope mounts used for mounting computers was designed
approximately 12 years ago. This includes the use of an industrialgrade
computer to control the system operation. The original
computer had a smaller, lighter enclosure. After a few years, a newer
computer version was introduced, which was 10 lbm heavier. Some
failures of internal computer parts have been documented for cases in
which the old mounts were used. Because of the added weight, there
is a possibility of having the two brackets impact each other under
off-road conditions, which causes a high shock input to the computer
parts. This added failure mode requires validating the existing mount
design to suit the new heavy-weight computer.
This paper discusses the modal finite element method (FEM)
analysis and experimental modal analysis conducted to study the
effects of vibration on the wire rope mounts and the computer. The
existing mount was modelled in ANSYS software, and resultant
mode shapes and frequencies were obtained. The experimental modal
analysis was conducted, and actual frequency responses were
observed and recorded.
Results clearly revealed that at resonance frequency, the brackets
were colliding and potentially causing damage to computer parts. To
solve this issue, spring mounts of different stiffness were modeled in
ANSYS software, and the resonant frequency was determined.
Increasing the stiffness of the system increased the resonant
frequency zone away from the frequency window at which the engine
showed heavy vibrations or resonance. After multiple iterations in
ANSYS software, the stiffness of the spring mount was finalized,
which was again experimentally validated.
Abstract: Cross flow water tube heat exchanger can be designed
and made operational using methods of model building and
simulation of the system. This paper projects the design and
development of a model of cross flow water tube heat-exchanger
system, simulation and validation of control analysis of different
tuning methods. Feedback and override control system is developed
using inputs acquired with the help of sensory system. A
mathematical model is formulated for analysis of system behaviour.
The temperature is regulated at the desired set point automatically.
Abstract: At present, the evaluation of voltage stability
assessment experiences sizeable anxiety in the safe operation of
power systems. This is due to the complications of a strain power
system. With the snowballing of power demand by the consumers
and also the restricted amount of power sources, therefore, the system
has to perform at its maximum proficiency. Consequently, the
noteworthy to discover the maximum ability boundary prior to
voltage collapse should be undertaken. A preliminary warning can be
perceived to evade the interruption of power system’s capacity. The
effectiveness of line voltage stability indices (LVSI) is differentiated
in this paper. The main purpose of the indices used is to predict the
proximity of voltage instability of the electric power system. On the
other hand, the indices are also able to decide the weakest load buses
which are close to voltage collapse in the power system. The line
stability indices are assessed using the IEEE 14 bus test system to
validate its practicability. Results demonstrated that the implemented
indices are practically relevant in predicting the manifestation of
voltage collapse in the system. Therefore, essential actions can be
taken to dodge the incident from arising.
Abstract: Logistics distributors face the issue of having to
provide increasing service levels while being forced to reduce costs at
the same time. Same-day delivery, quick order processing and rapidly
growing ranges of articles are only some of the prevailing challenges.
One key aspect of the performance of an intra-logistics system is how
often and in which amplitude congestions and dysfunctions affect the
processing operations. By gaining knowledge of the so called
‘performance availability’ of such a system during the planning stage,
oversizing and wasting can be reduced whereas planning
transparency is increased. State of the art for the determination of this
KPI is simulation studies. However, their structure and therefore their
results may vary unforeseeably. This article proposes a concept for
the establishment of ‘certified’ and hence reliable and comparable
simulation models.
Abstract: This paper designs the four-phase Boost Converter
which overcomes the problem of high input ripple current and output
ripple voltage. Digital control is more convenient for such a topology
on basis of synchronization, phase shift operation, etc. Simulation
results are presented for open-loop and closed-loop for four phase
boost converter. This control scheme is applicable for PFC rectifiers
as well. Thus a comparative analysis based on the obtained results is
performed.
Abstract: Supply chain (SC) is an operational research (OR)
approach and technique which acts as catalyst within central nervous
system of business today. Without SC, any type of business is at
doldrums, hence entropy. SC is the lifeblood of business today
because it is the pivotal hub which provides imperative competitive
advantage. The paper present a conceptual framework dubbed as
Homomorphic Conceptual Framework for Effective Supply Chain
Strategy (HCEFSC).The term Homomorphic is derived from abstract
algebraic mathematical term homomorphism (same shape) which
also embeds the following mathematical application sets:
monomorphisms, isomorphism, automorphisms, and endomorphism.
The HCFESC is intertwined and integrated with wide and broad sets
of elements.
Abstract: Axial flow fans, while incapable of developing high
pressures, they are well suitable for handling large volumes of air at
relatively low pressures. In general, they are low in cost and possess
good efficiency, and can have blades of airfoil shape. Axial flow fans
show good efficiencies, and can operate at high static pressures if
such operation is necessary. Our objective is to model and analyze
the flow through AXIAL FANS using CFD Software and draw
inference from the obtained results, so as to get maximum efficiency.
The performance of an axial fan was simulated using CFD and the
effect of variation of different parameters such as the blade number,
noise level, velocity, temperature and pressure distribution on the
blade surface was studied. This paper aims to present a final 3D CAD
model of axial flow fan. Adapting this model to the available
components in the market, the first optimization was done. After this
step, CFX flow solver is used to do the necessary numerical analyses
on the aerodynamic performance of this model. This analysis results
in a final optimization of the proposed 3D model which is presented
in this article.
Abstract: Fuzzy inference method based approach to the
forming of modular intellectual system of assessment the quality of
communication services is proposed. Developed under this approach
the basic fuzzy estimation model takes into account the
recommendations of the International Telecommunication Union in
respect of the operation of packet switching networks based on IPprotocol.
To implement the main features and functions of the fuzzy
control system of quality telecommunication services it is used
multilayer feedforward neural network.
Abstract: The demand of high quality services has fueled
dimensional research and development in wireless communications
and networking. As a result, different wireless technologies like
Wireless LAN, CDMA, GSM, UMTS, MANET, Bluetooth and
satellite networks etc. have emerged in the last two decades. Future
networks capable of carrying multimedia traffic need IP convergence,
portability, seamless roaming and scalability among the existing
networking technologies without changing the core part of the
existing communications networks. To fulfill these goals, the present
networking systems are required to work in cooperation to ensure
technological independence, seamless roaming, high security and
authentication, guaranteed Quality of Services (QoS). In this paper, a
conceptual framework for a cooperative network (CN) is proposed
for integration of heterogeneous existing networks to meet out the
requirements of the next generation wireless networks.
Abstract: Ontologies offer a means for representing and sharing
information in many domains, particularly in complex domains. For
example, it can be used for representing and sharing information
of System Requirement Specification (SRS) of complex systems
like the SRS of ERTMS/ETCS written in natural language. Since
this system is a real-time and critical system, generic ontologies,
such as OWL and generic ERTMS ontologies provide minimal
support for modeling temporal information omnipresent in these SRS
documents. To support the modeling of temporal information, one
of the challenges is to enable representation of dynamic features
evolving in time within a generic ontology with a minimal redesign
of it. The separation of temporal information from other information
can help to predict system runtime operation and to properly design
and implement them. In addition, it is helpful to provide a reasoning
and querying techniques to reason and query temporal information
represented in the ontology in order to detect potential temporal
inconsistencies. To address this challenge, we propose a lightweight
3-layer temporal Quality of Service (QoS) ontology for representing,
reasoning and querying over temporal and non-temporal information
in a complex domain ontology. Representing QoS entities in separated
layers can clarify the distinction between the non QoS entities
and the QoS entities in an ontology. The upper generic layer of
the proposed ontology provides an intuitive knowledge of domain
components, specially ERTMS/ETCS components. The separation of
the intermediate QoS layer from the lower QoS layer allows us to
focus on specific QoS Characteristics, such as temporal or integrity
characteristics. In this paper, we focus on temporal information that
can be used to predict system runtime operation. To evaluate our
approach, an example of the proposed domain ontology for handover
operation, as well as a reasoning rule over temporal relations in this
domain-specific ontology, are presented.