Abstract: In this paper, a new efficient method for load balancing in low voltage distribution systems is presented. The proposed method introduces an improved Leap-frog method for optimization. The proposed objective function includes the difference between three phase currents, as well as two other terms to provide the integer property of the variables; where the latter are the status of the connection of loads to different phases. Afterwards, a new algorithm is supplemented to undertake the integer values for the load connection status. Finally, the method is applied to different parts of Tabriz low voltage network, where the results have shown the good performance of the proposed method.
Abstract: Many IT projects come to failure because of having
technical approach, focusing on the final product and lack of proper
attention to strategic alignment. Project management models quite
often have technical management view [4], [8], [13], [14]. These
models focus greatly on the finalization of the project product and the
delivery of the product to the customer. However, many project
problems are due to lack of attention to the needs and capabilities of
the organizations or disregarding how to deploy and use the product
in the organization. In this regard, in the current research we are
trying to present a solution with the purpose of raising the value of
the project in an organization. This way, the project outputs will be
properly deployed in the organization. Therefore, a comprehensive
model is presented which takes into account the whole processes
from initial step of project definition to the deployment of the final
outputs in the organization and then the definition of all roles and
responsibilities to put the model into practice. Taking into account
the opinions of experts and project managers, to prove the
performance of the model, the project problems were recognized and
based on the model, categorized and analyzed. And at the end it is
made clear that ignoring the proper definition of the project and not
having a proper understanding of the expected value on the one hand
and not supervising the emerged value in the process of production
and installment are among the most important factors that bring a
project to failure.
Abstract: The multiple traveling salesman problem (mTSP) can be used to model many practical problems. The mTSP is more complicated than the traveling salesman problem (TSP) because it requires determining which cities to assign to each salesman, as well as the optimal ordering of the cities within each salesman's tour. Previous studies proposed that Genetic Algorithm (GA), Integer Programming (IP) and several neural network (NN) approaches could be used to solve mTSP. This paper compared the results for mTSP, solved with Genetic Algorithm (GA) and Nearest Neighbor Algorithm (NNA). The number of cities is clustered into a few groups using k-means clustering technique. The number of groups depends on the number of salesman. Then, each group is solved with NNA and GA as an independent TSP. It is found that k-means clustering and NNA are superior to GA in terms of performance (evaluated by fitness function) and computing time.
Abstract: This paper presents an optimization technique to economic load dispatch (ELD) problems with considering the daily load patterns and generator constraints using a particle swarm optimization (PSO). The objective is to minimize the fuel cost. The optimization problem is subject to system constraints consisting of power balance and generation output of each units. The application of a constriction factor into PSO is a useful strategy to ensure convergence of the particle swarm algorithm. The proposed method is able to determine, the output power generation for all of the power generation units, so that the total constraint cost function is minimized. The performance of the developed methodology is demonstrated by case studies in test system of fifteen-generation units. The results show that the proposed algorithm scan give the minimum total cost of generation while satisfying all the constraints and benefiting greatly from saving in power loss reduction
Abstract: This paper proposed a nonlinear model predictive
control (MPC) method for the control of gantry crane. One of the main
motivations to apply MPC to control gantry crane is based on its
ability to handle control constraints for multivariable systems. A
pre-compensator is constructed to compensate the input nonlinearity
(nonsymmetric dead zone with saturation) by using its inverse
function. By well tuning the weighting function matrices, the control
system can properly compromise the control between crane position
and swing angle. The proposed control algorithm was implemented for
the control of gantry crane system in System Control Lab of University
of Technology, Sydney (UTS), and achieved desired experimental
results.
Abstract: We propose a formal framework for the specification of
the behavior of a system of agents, as well as those of the constituting
agents. This framework allows us to model each agent-s effectoric
capability including its interactions with the other agents. We also
provide an algorithm based on Milner-s "observation equivalence" to
derive an agent-s perception of its task domain situations from its
effectoric capability, and use "system computations" to model the
coordinated efforts of the agents in the system . Formal definitions
of the concept of "behavior equivalence" of two agents and that of
system computations equivalence for an agent are also provided.
Abstract: Infrared communication in the wavelength band 780-
950 nm is very suitable for short-range point-to-point communications.
It is a good choice for vehicle-to-vehicle communication in several
intelligent-transportation-system (ITS) applications such as cooperative
driving, collision warning, and pileup-crash prevention. In this
paper, with the aid of a physical model established in our previous
works, we explore the communication area of an infrared intervehicle
communication system utilizing a typical low-cost cormmercial lightemitting
diodes (LEDs) as the emitter and planar p-i-n photodiodes
as the receiver. The radiation pattern of the emitter fabricated by
aforementioned LEDs and the receiving pattern of the receiver are
approximated by a linear combination of cosinen functions. This
approximation helps us analyze the system performance easily. Both
multilane straight-road conditions and curved-road conditions with
various radius of curvature are taken into account. The condition of
a small car communicating with a big truck, i.e., there is a vertical
mounting height difference between the emitter and the receiver, is
also considered. Our results show that the performance of the system
meets the requirement of aforementioned ITS applications in terms
of the communication area.
Abstract: This paper presents a new method of fault detection and isolation (FDI) for polymer electrolyte membrane (PEM) fuel cell (FC) dynamic systems under an open-loop scheme. This method uses a radial basis function (RBF) neural network to perform fault identification, classification and isolation. The novelty is that the RBF model of independent mode is used to predict the future outputs of the FC stack. One actuator fault, one component fault and three sensor faults have been introduced to the PEMFC systems experience faults between -7% to +10% of fault size in real-time operation. To validate the results, a benchmark model developed by Michigan University is used in the simulation to investigate the effect of these five faults. The developed independent RBF model is tested on MATLAB R2009a/Simulink environment. The simulation results confirm the effectiveness of the proposed method for FDI under an open-loop condition. By using this method, the RBF networks able to detect and isolate all five faults accordingly and accurately.
Abstract: In recent years the large scale use of the power electronic equipment has led to an increase of harmonics in the power system. The harmonics results into a poor power quality and have great adverse economical impact on the utilities and customers. Current harmonics are one of the most common power quality problems and are usually resolved by using shunt active filter (SHAF). The main objective of this work is to develop PI and Fuzzy logic controllers (FLC) to analyze the performance of Shunt Active Filter for mitigating current harmonics under balanced and unbalanced sinusoidal source voltage conditions for normal load and increased load. When the supply voltages are ideal (balanced), both PI and FLC are converging to the same compensation characteristics. However, the supply voltages are non-ideal (unbalanced), FLC offers outstanding results. Simulation results validate the superiority of FLC with triangular membership function over the PI controller.
Abstract: Speed sensorless systems are intensively studied during recent years; this is mainly due to their economical benefit and fragility of mechanical sensors and also the difficulty of installing this type of sensor in many applications. These systems suffer from instability problems and sensitivity to parameter mismatch at low speed operation. In this paper an analysis of adaptive observer stability with stator resistance estimation is given.
Abstract: Random Oracle Model (ROM) is an effective method
for measuring the practical security of cryptograph. In this paper, we
try to use it into information hiding system (IHS). Because IHS has its
own properties, the ROM must be modified if it is used into IHS.
Firstly, we fully discuss why and how to modify each part of ROM
respectively. The main changes include: 1) Divide the attacks that IHS
may be suffered into two phases and divide the attacks of each phase
into several kinds. 2) Distinguish Oracles and Black-boxes clearly. 3)
Define Oracle and four Black-boxes that IHS used. 4) Propose the
formalized adversary model. And 5) Give the definition of judge.
Secondly, based on ROM of IHS, the security against known original
cover attack (KOCA-KOCA-security) is defined. Then, we give an
actual information hiding scheme and prove that it is
KOCA-KOCA-secure. Finally, we conclude the paper and propose the
open problems of further research.
Abstract: This paper proposes new algorithms for the computeraided
design and manufacture (CAD/CAM) of 3D woven multi-layer
textile structures. Existing commercial CAD/CAM systems are often
restricted to the design and manufacture of 2D weaves. Those
CAD/CAM systems that do support the design and manufacture of
3D multi-layer weaves are often limited to manual editing of design
paper grids on the computer display and weave retrieval from stored
archives. This complex design activity is time-consuming, tedious
and error-prone and requires considerable experience and skill of a
technical weaver. Recent research reported in the literature has
addressed some of the shortcomings of commercial 3D multi-layer
weave CAD/CAM systems. However, earlier research results have
shown the need for further work on weave specification, weave
generation, yarn path editing and layer binding. Analysis of 3D
multi-layer weaves in this research has led to the design and
development of efficient and robust algorithms for the CAD/CAM of
3D woven multi-layer textile structures. The resulting algorithmically
generated weave designs can be used as a basis for lifting plans that
can be loaded onto looms equipped with electronic shedding
mechanisms for the CAM of 3D woven multi-layer textile structures.
Abstract: In this paper, supply policy and procurement of
shared resources in some kinds of concurrent construction projects
are investigated. This could be oriented to the problems of holding
construction companies who involve in different projects
concurrently and they have to supply limited resources to several
projects as well as prevent delays to any project. Limits on
transportation vehicles and storage facilities for potential
construction materials and also the available resources (such as cash
or manpower) are some of the examples which affect considerably on
management of all projects over all. The research includes
investigation of some real multi-storey buildings during their
execution periods and surveying the history of the activities. It is
shown that the common resource demand variation curve of the
projects may be expanded or displaced to achieve an optimum
distribution scheme. Of course, it may cause some delay to some
projects, but it has minimum influence on whole execution period of
all projects and its influence on procurement cost of the projects is
considerable. These observations on investigation of some
multistorey building which are built in Iran will be presented in this
paper.
Abstract: The neural network's performance can be measured by efficiency and accuracy. The major disadvantages of neural network approach are that the generalization capability of neural networks is often significantly low, and it may take a very long time to tune the weights in the net to generate an accurate model for a highly complex and nonlinear systems. This paper presents a novel Neuro-fuzzy architecture based on Extended Kalman filter. To test the performance and applicability of the proposed neuro-fuzzy model, simulation study of nonlinear complex dynamic system is carried out. The proposed method can be applied to an on-line incremental adaptive learning for the prediction of financial time series. A benchmark case studie is used to demonstrate that the proposed model is a superior neuro-fuzzy modeling technique.
Abstract: A newly designed gas-distributor for granulation of powdery materials in equilibrated fluidized bed and a system for collecting the granules prepared are suggested. The aim of these designs is to solve the problems arising by the granulation of powdery materials in fluidized bed devices. The gasdistributor and the collection system proved to be reliable at operation; they reduce the size of still zones, effectively disperse the binding solution in the bed and ensure the collection of granules of given diameter
Abstract: In the current research, we present an operation framework and protection mechanism to facilitate secure environment to protect mobile agents against tampering. The system depends on the presence of an authentication authority. The advantage of the proposed system is that security measures is an integral part of the design, thus common security retrofitting problems do not arise. This is due to the presence of AlGamal encryption mechanism to protect its confidential content and any collected data by the agent from the visited host . So that eavesdropping on information from the agent is no longer possible to reveal any confidential information. Also the inherent security constraints within the framework allow the system to operate as an intrusion detection system for any mobile agent environment. The mechanism is tested for most of the well known severe attacks against agents and networked systems. The scheme proved a promising performance that makes it very much recommended for the types of transactions that needs highly secure environments, e. g., business to business.
Abstract: The authors present a mixed method for reducing the order of the large-scale dynamic systems. In this method, the denominator polynomial of the reduced order model is obtained by using the modified pole clustering technique while the coefficients of the numerator are obtained by Pade approximations. This method is conceptually simple and always generates stable reduced models if the original high-order system is stable. The proposed method is illustrated with the help of the numerical examples taken from the literature.
Abstract: In this paper, the modelling and design of artificial neural network architecture for load forecasting purposes is investigated. The primary pre-requisite for power system planning is to arrive at realistic estimates of future demand of power, which is known as Load Forecasting. Short Term Load Forecasting (STLF) helps in determining the economic, reliable and secure operating strategies for power system. The dependence of load on several factors makes the load forecasting a very challenging job. An over estimation of the load may cause premature investment and unnecessary blocking of the capital where as under estimation of load may result in shortage of equipment and circuits. It is always better to plan the system for the load slightly higher than expected one so that no exigency may arise. In this paper, a load-forecasting model is proposed using a multilayer neural network with an appropriately modified back propagation learning algorithm. Once the neural network model is designed and trained, it can forecast the load of the power system 24 hours ahead on daily basis and can also forecast the cumulative load on daily basis. The real load data that is used for the Artificial Neural Network training was taken from LDC, Gujarat Electricity Board, Jambuva, Gujarat, India. The results show that the load forecasting of the ANN model follows the actual load pattern more accurately throughout the forecasted period.
Abstract: The process of constructing a scale measuring the attitudes of youth toward violence on televisions is reported. A 30-item draft attitude scale was applied to a working group of 232 students attending the Faculty of Educational Sciences at Ankara University between the years 2005-2006. To introduce the construct validity and dimensionality of the scale, exploratory and confirmatory factor analysis was applied to the data. Results of the exploratory factor analysis showed that the scale had three factors that accounted for 58,44% (22,46% for the first, 22,15% for the second and 13,83% for the third factor) of the common variance. It is determined that the first factor considered issues related individual effects of violence on televisions, the second factor concerned issues related social effects of violence on televisions and the third factor concerned issues related violence on television programs. Results of the confirmatory factor analysis showed that all the items under each factor are fitting the concerning factors structure. An alpha reliability of 0,90 was estimated for the whole scale. It is concluded that the scale is valid and reliable.
Abstract: The cost of damage to the non-structural systems in
critical facilities like nuclear power plants and hospitals can exceed
80% of the total cost of damage during an earthquake. The failure of
nonstructural components, especially, piping systems led to leakage of
water and subsequent shut-down of hospitals immediately after the
event. Consequently, the evaluation of performance of these types of
structural configurations has become necessary to mitigate the risk and
to achieve reliable designs.
This paper focuses on a methodology to evaluate the static and
dynamic characteristics of complex actual piping system based on
NFPA-13 and SMACNA guidelines. The result of this study revealed
that current piping system subjected to design lateral force and design
spectrum based on UBC-97 was failed in both cases and mode shapes
between piping system and building structure were very different