Dyed sensitized solar cells: A technically and economically alternative concept to p-n junction photovoltaic devices
October 2011
Nanocrystalline dyed sensitized solar cells (DSSC) are photo-electrochemical cells based on principles similar to the processes in natural photosynthesis. They are based on photo sensitization of nanocrystalline semiconductor electrodes by absorbed dyes. The DSSC provides a technically and economically credible alternative concept to present day p–n junction photovoltaic devices. The DSSC work on a different...
Mathematical models for component commonality under quality and resources breakdown in multistage production
October 2011
In the era of mass customization and supply chain rivalry, managing product diversity is essential for survival in business. The use of common part for different products is a vital method of achieving the goal. The advantages of insertion of duplicate component in a product family are stated in literatures. Simulation or conceptual beliefs is employed in the majority of the researches and mainly considered single stage...
Some iterative algorithms for trifunction equilibrium variational inequalities
October 2011
In this paper, we use the auxiliary principle technique to suggest and analyze some iterative methods for solving a new class of equilibrium problems and variational inequalities, which is called the trifunction equilibrium variational inequality. Convergence of these iterative methods is proved under very mild and suitable assumptions. Several special cases are also considered. Results proved in this paper continue to...
Direction of arrival estimation using modified orthogonal matching pursuit algorithm
October 2011
Direction of arrival (DOA) estimation is a sparse reconstruction problem. However, conventional orthogonal matching pursuit (OMP) may fail to identify the correct atoms since the redundant dictionary composed of the direction vectors is highly coherent. To mitigate the coherence problem, in this paper, we propose a modified OMP by constructing data dependent sensing dictionary for sparse reconstruction in...
Dynamical analysis of clustering-based wireless sensor networks
October 2011
In wireless sensor networks (WSNs), clustering-based algorithms have been proved to be effective techniques to save energy and improve fault tolerance. In this paper, a scale-free evolving model for clustering-based WSNs with exponential growth behavior is presented, in which the nodes arrive as a Poisson process with rate λ. This model takes into account four types of evolving events: selection of cluster-head...
The effect of geological and geotechnical factors on the project design of coastal structures (Alanya Marina case study)
October 2011
Coastal areas of Turkey are scientifically, culturally and economically very important places because of values in geomorphological, geological, biological, archeological and tourism properties. In this study, coastal structures are classified; and design phases of shore structures and required geological and geotechnical studies before design are explained. As an example, geological and geotechnical studies carried out...
Heat treatment of Al2O3-SiC-MgO nanoceramic and optimizing the fracture performance
October 2011
In this study, the procedure of sintering and heat treatment of Al2O3-SiC-MgO nanoceramic was considered. For improving the densification behavior and mechanical properties, experimental variables, such as sintering temperature and duration, which significantly influence the fracture performance of this nanocomposite body, were optimized. To obtain desired properties, several tests were conducted on the nanoceramic...
Assessment of high strength and light weight aggregate concrete properties using ultrasonic pulse velocity technique
October 2011
In this study, the ultrasonic pulse velocity technique as a non-destructive testing of concrete was used to assess the effect of some criteria on high strength and light weight aggregate concrete. The study included several concrete mix design with ages of 7, 28 and 90 days. The effect of age, cement content, water ratio and slump on two concrete types was studied and discussed. The use of...
Online inter-area oscillation monitoring in power systems using PMU data and Prony analysis
October 2011
In this paper, signals measured by phasor measurement units (PMUs) are used to monitor power system small signal stability. In the proposed method, proper signals selected based on the modes observability and Prony analysis is employed to extract signal damping information (amplitude and frequency of participated modes) in real-time. The proposed method is simulated using a test signal in ideal and noisy environment....
Dynamic stability enhancement and voltage support using UPFC tuned genetic algorithms in a multi- machine environment
October 2011
Unified power flow controller (UPFC) is one of the most important flexible AC transmission systems (FACTS) devices in power systems. It has many applications such as stability enhancement, power flow control, voltage support, etc. In this paper UPFC is used in order to control voltage. In this scope, UPFC is installed on a specified bus and the voltage of the proposed bus is controlled by using UPFC. In order to...
High voltage buried step-doping p+ layer silicon-on-insulator lateral double diffused mosfet (SOI LDMOSI) with a back-gate
October 2011
A high voltage buried step-doping p+layer (BSP+L) lateral double diffused mosfet (LDMOS) on silicon-on-insulator (SOI) with a back-gate is proposed. The new structure is characterized by a BSP+L on the buried oxide under the source. When a high positive bias is applied to the back-gate in the off-state, the depleted BSP+L greatly enhances the electric field in the buried oxide layer under the source. Compared with...
The effectiveness of using a recharge well to mitigate flood measured in a physical model
October 2011
A structural method that involves the use of a recharge well to mitigate flood in a flat area is adopted as a mitigation method for this research. The determination of the effectiveness of this method was carried out by simulating storm-water accumulation in a reduced scaled physical model. The physical model had a rainfall simulator fitted to a sand tank which contained soil materials of different grain size and...
An application of different artificial intelligences techniques for water quality prediction
October 2011
Artificial Intelligence (AI) is a new technique with a flexible mathematical structure that is capable of identifying complex non-linear relationships between input and output data when compared with other classical modelling techniques. In this study, different techniques of AI have been investigated in prediction of water quality parameters including: multi-layer perceptron neural networks...
Ecological implication of market gardenning in the old Ogoja zone of Nigeria
October 2011
Man’s attempt to improve his income and also supplement his food especially during dry season in the old Ogoja zone has led him to develop dry season farming along watershed. Man’s farming activities mainly for market gardening has impacted in no small way on the environment which has resulted in the reduction of rainfall volume, increase temperature, biodiversity depletion and soil fertility loss. In this...
An evolutionary multi-objective optimization algorithm for portfolio selection problem
October 2011
Cultural algorithms (CAs) are one of the metaheuristics which can be adapted in order to work in multi-objective optimization environments. On the other hand, portfolio selection problem (PSP) is a well-know problem in literature. However, only a few articles have applied evolutionary multi-objective (EMO) algorithms to these problems and articles presenting CAs applied to the PSP have not been found. In this article,...
Pluggable, interoperable and extensible (PIE): A grid portal for interoperability
October 2011
The main challenge grid computing environment faces today is to provide interoperability andenable collaboration between multitudes of grids. Standardization is a long term solution to enable interoperability. Grid portals and gateways have emerged to be important components in addressing interoperability challenge in grid environments to enable collaboration and expand the pool of resources available. In...
Lean software tool for lead time reduction
October 2011
Lean manufacturing, or simply lean, is a production process used to eliminate the waste from all phases of an organization’s operations and in improving the long term maximization of company resources. Finding a problem is the first step and essential part of a research process that can be investigated in the production process of a factory. For example, the major problems found in the warehouse area of a food...
On-line surface roughness recognition system by vibration monitoring in CNC turning using adaptive neuro-fuzzy inference system (ANFIS)
October 2011
This study presents a new method for modeling an adaptive neuro-fuzzy inference system (ANFIS) based on vibration for predicting surface roughness in the CNC turning process. The input parameters of the model are insert nose radius, cutting speed, feed rate, depth of cut and vibration amplitude, which determine the output parameter of the surface roughness. A Gauss type membership function was used to train on ANFIS....
A comparison between minimum-statistics and soft-decision noise estimation methods
October 2011
Speech enhancement has been used in a variety of applications such as mobile phones, hearing aids and speech recognition systems. One of the most fundamental steps in manyspeech enhancement methods is noise estimation. Inexact noise estimation results in undesired effects in the enhanced signal. While over-estimating the noise leads to speech distortion, noise under-estimation leaves some annoying noise in the enhanced...
Polymer-noble metal nanocomposites: Review
September 2011
Polymer-noble metal nanocomposites have been extensively investigated due to their potential ability to provide materials with novel mechanical, electronic or chemical behaviour for technological applications. Many preparative procedures have been proposed and detailed characterizations have been carried out on conducting polymer-noble metal nanocomposites; thanks to the rapid improvement in analytical techniques on...
Innovative countermeasure for integral bridge scour
September 2011
Advantages of integral bridges include reduction of initial construction and maintenance cost. Scour was the main problem which caused the bridges to fail and collapse during heavy rain and flooding. Most of the previous studies focused on the scouring impact on conventional and traditional bridge. Very few studies investigated on scouring effects on integral bridge and its countermeasure. This paper highlighted the...
Integrating performance indicator analysis and comparisons in NPD process re-engineering
September 2011
The purpose of the present study is to develop a strategy that integrates all output and feedback from customers (internal and external) with a view to enhancing the new product development (NPD) performance of a manufacturing company. This study combines theory and practice to develop a framework using three analytical dimensions that can be used to identify and solve the problems that arise in NPD strategy...
Ammonia loss reduction, exchangeable ammonium and available nitrate retention in soil treated with urea mixed with humic acid and acid sulphate soil
September 2011
Exchangeable ammonium (NH4+) could be recovered in soil by the application of humic acid (HA) and acid sulphate soil. The ability of humic acids to retain NH4+ has been demonstrated in our previous study. In that study, the effect of both acids on soil exchangeable NH4+, dry matter production and available nitrate (NO3-) was investigated.This laboratory study compared the effect of enhancing urea mixtures with HA...
Application of new reactive and disperse dye on textile dyeing, printing with acrylate Eco friendly copolymers
September 2011
This research work examines the process of dyeing polyester/cotton fabrics with a highly effective fiber-reactive and a disperse dyestuffs namely, (E)-4-hydroxy-5-((4-((2-sulfophenyl)amino)-1,3,5-triazin-2-yl)amino)-3-((2-sulfophenyl)diazenyl)naphthalene-2,7-disulfonic acid and (E)-5-((4-nitrophenyl)diazenyl)pyridin-2(1H)-one, respectively in one pot processes of printing and dyeing. It gives special attention to modify...
Convection from a semi-finite plate in a fluid saturated porous medium with cross-diffusion and radiative heat transfer
September 2011
The heat and mass transfer characteristics in mixed convection along a semi-infinite plate in a fluid saturated porous medium with radiative heat transfer has been investigated. Diffusion-thermo and thermo-diffusion effects are assumed to be significant. Using a similarity transformation, the governing steady boundary layer equations for the momentum, heat and mass transfer were reduced to a set of ordinary differential...
Designing a model to use solar energy for heating usages of domestic constructions in Khouzestan province
September 2011
In this research, the amount of solar radiation and its effect on domestic buildings of Ahvaz (the center of Khuzestan province) has been studied. To this end, we establish a model (dimension:), which has some pipes (Diameter: 1.375 Inch, Copper) on the outer surface of the roof, acting as a radiator. To absorb maximum amount of energy and being able to use the system in various latitudes, we set pipes on a movable...
Modeling of saturated salient pole synchronous machines in d-q axes
September 2011
This paper presents the modeling of saturated salient pole synchronous machines in standard d-q axes. First, a complete synthesis of possible d-q axes models is given.Second, the salient pole synchronous machine is transformed into an equivalent smooth air gap machine, in order to apply the main flux saturation method. Third, a description of a procedure to introduce magnetic saturation in found models is...
Urban microzonation study for Esenler district, Istanbul, Turkey
September 2011
It is necessary to prepare the microzonation maps and determine the better soil sites in settlement areas which are located on active tectonic regions. In this study, the geological, geophysical and geotechnical conditions of the Esenler district (Istanbul) were investigated and a small scales microzonation study was carried out. The northern sides of the study area generally represented by Lower Carboniferous aged...
Ricci tensors for elliptical shaped galaxies and celestial objects
September 2011
Einstein's field equations are based on Riemannian geometry. One of the great important in Riemannian geometry is the curves that minimize the distance between two given points. The Ricci curvature tensors are also broadly applicable to modern Riemannian geometry and general theory of relativity (GTR). The solution of Einstein's field equations, need Ricci tensors. The line elements based on the ellipsoidal...
Comparative analysis of fetal electrocardiogram (ECG) extraction techniques using system simulation
September 2011
This paper presents a system simulation to compare between two adaptive filters based on recursive least square (RLS) and normalized least mean square (NLMS), in their use for fetal heart rate (FHR) monitoring. The reference and primary signals are fed simultaneously to the inputs of the RLS and NLMS adaptive filters to extract the fetal signal. Each extracted signal is postprocessed using a newly developed...
Using agents to improve the usability of the PSP automated tool
September 2011
Various tools have been produced to assist personal software process (PSP) practitioners in implementing their processes, which require strong discipline from the individual software engineer. Nevertheless, most of the currently available tools still require software engineers to become involved in time-consuming manual processes and offer limited assistance. This research study presents the substantial potential for...
Fractional optimum linear receiver for quasi-static MIMO systems
September 2011
The minimum mean squared error (MMSE) based linear receiver used with multiple-input multiple-output (MIMO) systems, is considered to be the optimum as it jointly cancels out noise and interference. The MMSE receiver maximizes the signal to interference plus noise ratio (SINR) and minimizes the bit error rate (BER). In this paper, the concept of fractional domain based optimum MMSE receiver is proposed. The proposed...
Kinematic calibration of a parallel robot using coordinate measuring machine
September 2011
In the applications of parallel robots, kinematic calibration is required to eliminate the errors resulting from the manufacturing and assembly. In this paper, a new method for calibrating a parallel robot is proposed. An error model for kinematic calibration is constructed using differential geometry method. All leg length information and pose error are obtained based on measurement results coordinate measuring...
Parallel robots pose accuracy compensation using back propagation network
September 2011
In order to improve pose accuracy of a parallel robot in the application, a compensator is constructed to predict leg length errors using back propagation neural network. In this method, the back propagation neural network is used with conventional inverse kinematics computation module in parallel. A back propagation neural network is designed and implemented to learn kinematic model errors for parallel robots. The...
Search for critical failure surface in slope stability analysis by gravitational search algorithm
September 2011
Slope stability analysis of any natural or artificial slope aims at determining the factor of safety of the slip surface that possesses the lowest factor of safety. The search for the minimum factor of safety based on limit equilibrium methods is a complex optimization problem where there are several local minima. In this paper, a newly developed heuristic global optimization algorithm, called gravitational search...
Visco-elastic MHD flow of Walters liquid B fluid and heat transfer over a non-isothermal stretching sheet
September 2011
An analytic study has been carried on steady MHD flow and heat transfer in a visco-elastic fluid flow over a semi-infinite, impermeable and non-isothermal stretching sheet with internal heat generation/absorption in the presence of radiation. Thermal conductivity is assumed to vary linearly with temperature. The governing partial differential equations are converted into ordinary differential equations by a similarity...
Effect of tire footprint area in pavement response studies
September 2011
The necessity of incorporating realistic non-uniform measured contact stresses, tire footprint area, as well as other non-linear and viscoelastic behaviour within tire-pavement interaction have been suggested by many researchers in order to obtain more reliable pavement responses. However, modeling 3D contact stresses with distribution and other non-linear properties in common pavement design procedure seems difficult...
Determination of effective atomic number and electron density of chitin by gamma-ray attenuation
September 2011
The effective atomic numbers (Zeff) and effective electron density (Ne) of chitin have been calculated using the mass attenuation coefficients (m/r) obtained via XCOM (COMpilation of X-ray Cross Sections) in the photon energy range between 1 keV and 1 GeV. The results were compared with the measured values at the photon energy of 662, 1173 and 1332 keV. Both measured and calculated results were in good...
A weak blind signature based on quantum cryptography
September 2011
In general, a weak blind signature has the characteristics of no-counterfeiting, no-disavowing, blindness and traceability. In this paper, a weak blind signature scheme based on the correlation of Einstein-Padolsky-Rosen (EPR) pairs (Xiaojun et al., 2009) is revisited, and it will be shown that the scheme in its original form does not complete the task of a blind signature fairly. Key words: Quantum...
Impact of land-use changes toward base-flow regime in Lui and Langat Dengkil sub-basin
September 2011
Lui River and Langat-Dengkil River sub-basin are one of the large portions of Langat River catchment, known as the prime and important water source for Kuala Lumpur, Petaling Jaya, Shah Alam, Klang as well as domestic and industries usage in the Langat River basin itself. Unfortunately, the land-use change has greatly impacted the base-flow regimes particularly for the upstream area of Lui...
Review of Erbium-doped fiber amplifier
September 2011
Data communication systems are increasingly employing optical fiber communication systems (OFCS) as the transmission paths for information. Various types of optical amplifiers have been developed in OFCS to amplify optical signals. In particular, the Erbium-doped fiber amplifier (EDFA) is one example of an optical fiber amplifier that is widely known for use in amplifying optical signals. The most significant points in...
Lubricating grease from spent bleaching earth and waste cooking oil: Tribology properties
September 2011
The recovery of waste from many industrial production plants and its applicability in product development may be an incentive to industry, since the use of such squander could represents a cheaper source of raw material for many of the important processes utilized in further manufacturing. This paper presents the incorporated of wastes in industries particularly palm oil industries for new multi-purpose grease. Spent...
Weakened Mannheim curves
September 2011
In the discussion of Bertrand and Mannheim curves, it is always assumed (explicitly or implicitly) that the curvature is nowhere zero. In this paper, we adapt this requirement on the Mannheim curves and investigate into the properties of two types of similar curves (the Frenet-Mannheim curves and the weakened Mannheim curves) under weakened conditions. Key words: Mannheim curves, Frenet-Mannheim...
Natural lift curves and the geodesic sprays for the spherical indicatrices of the involutes of a timelike curve in Minkowski 3-space
September 2011
The aim of this paper is to determine criteria of being integral curve for the geodesic spray of the natural lift curves of the spherical indicatrices of the involutes of a given timelike curve in Minkowski 3-space. Key words: Minkowski space, involute-evolute curve couple, geodesic spray, natural lift curve
Review of Erbium-doped fiber amplifier
September 2011
Data communication systems are increasingly employing optical fiber communication systems (OFCS) as the transmission paths for information. Various types of optical amplifiers have been developed in OFCS to amplify optical signals. In particular, the Erbium-doped fiber amplifier (EDFA) is one example of an optical fiber amplifier that is widely known for use in amplifying optical signals. The most significant points in...
A novel algorithm for solving fuzzy differential inclusions based on reachable set
September 2011
In this paper, a numerical method for solving th-order fuzzy differential inclusions with fuzzy initial conditions is considered. A scheme based on the classical Taylor method is discussed in full details, which is followed by a complete error analysis. The method is illustrated by solving some linear and nonlinear fuzzy initial value problems. Key words: Differential inclusions,...
An efficient two step Laplace decomposition algorithm for singular Volterra integral equations
September 2011
The aim of this article is to introduce a new reliable algorithm, namely two-step Laplace decomposition algorithm (TSLDA). This new algorithm provides us with a convenient way to find exact solution with less computation as compared with standard Laplace decomposition algorithm (LDA). The proposed algorithm is use to solve Abel's second kind integral equations efficiently. Key words: Two...
Seismic response control of sliding isolated buildings using adaptive fuzzy sliding mode control
September 2011
The purpose of this paper is to apply adaptive fuzzy sliding mode control for structurally controlling buildings with sliding bearing isolation. Combining fuzzy control and robust control such as sliding mode control, reduces fuzzy rule bases complexity and ensures stability and robustness. We use Lyapunov theory to develop a self-tuning law. Stiffness uncertainty and time delay is used to demonstrate the robustness of...
Second law based optimization of a plate fin heat exchanger using Imperialist Competitive Algorithm
September 2011
This study explores the application of Imperialist Competitive Algorithm (ICA) in thermodynamic optimization of a cross-flow plate fin heat exchanger. The optimization aims at finding the minimum number of total entropy generation units under a given heat duty and pressure drop constraints. Seven design parameters namely, hot side length, cold side length, fin height, fin frequency, fin thickness, number of fin layers...
Geophysical investigation of barite deposit in Tunga, Northeastern Nigeria
September 2011
Gravity and electromagnetic methods were combined to characterize known veins and possibly unveil other concealed veins in Tunga, Northeastern Nigeria. Barite occurs in the study area as vein deposits hosted in clean sandstone rocks. Laboratory analyses of samples show average specific gravity of the variety to vary between 3.16 and 4.24 while the host sandstone rock is 2.63. The study is focused on an area of 0.5...
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