Search results for: best efficiency point.

Authors: Minghui Wang, Juntao Zhang

Abstract:

An inversion-free iterative algorithm is presented for solving nonlinear matrix equation with a stepsize parameter t. The existence of the maximal solution is discussed in detail, and the method for finding it is proposed. Finally, two numerical examples are reported that show the efficiency of the method.

Keywords: Inversion-free method, Hermitian positive definite solution, Maximal solution, Convergence.

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Authors: K. Divya, G. Sugumaran

Abstract:

This paper proposes an improved Maximum Power Point Tracking of PhotoVoltaic system using Deterministic Partical Swarm Optimization technique. This method has the ability to track the maximum power under varying environmental conditions i.e. partial shading conditions. The advantage of this method, particles moves in the restricted value of velocity to achieve the maximum power. SEPIC converter is employed to boost up the voltage of PV system. To estimate the value of the proposed method, MATLAB simulation carried out under partial shading condition.

Keywords: DPSO, Partial shading condition, P&O, PV, SEPIC.

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Authors: Marjan Mansourvar, Norizan Mohd Yasin

Abstract:

The development of Web has affected different aspects of our lives, such as communication, sharing knowledge, searching for jobs, social activities, etc. The web portal as a gateway in the World Wide Web is a starting point for people who are connecting to the Internet. The web portal as the type of knowledge management system provides a rich space to share and search information as well as communication services like free email or content provision for the users. This research aims to discover the university needs to the web portal as a necessary tool for students in the universities to help them in getting the required information. A survey was conducted to gather students' requirements which can be incorporated in to portal to be developed.

Keywords: Knowledge, Knowledge management system, Knowledge sharing, web portal.

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Authors: Min Sun, Jing Liu

Abstract:

In this paper, we focus on the alternating direction method, which is one of the most effective methods for solving structured variational inequalities(VI). In fact, we propose a proximal parallel alternating direction method which only needs to solve two strongly monotone sub-VI problems at each iteration. Convergence of the new method is proved under mild assumptions. We also present some preliminary numerical results, which indicate that the new method is quite efficient.

Keywords: structured variational inequalities, proximal point method, global convergence

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Authors: Xiangjun Li, Huaiyuan Tian, Wujie Zhang, Dianhua Liu

Abstract:

Polyoxymethylene dimethyl ethers (PODE_n) as clean diesel additive can improve the combustion efficiency and quality of diesel fuel and alleviate the problem of atmospheric pollution. Considering synthetic routes, PODE production from methanol and formaldehyde is regarded as the most economical and promising synthetic route. However, methanol used for synthesizing PODE can produce water, which causes the loss of active center of catalyst and hydrolysis of PODE_n in the production process. Macroporous strong acidic cation exchange resin catalyst was prepared, which has comparative advantages over other common solid acid catalysts in terms of stability and catalytic efficiency for synthesizing PODE. Catalytic reactions were carried out under 353 K, 1 MPa and 3mL·g_cat^-1·h^-1 in a fixed bed reactor. Methanol conversion and PODE_3-6 selectivity reached 49.91% and 23.43%, respectively. Catalyst lifetime evaluation showed that resin catalyst retained its catalytic activity for 20 days without significant changes and catalytic activity of completely deactivated resin catalyst can basically return to previous level by simple acid regeneration. The acid exchange capacities of original and deactivated catalyst were 2.5191 and 0.0979 mmol·g^-1, respectively, while regenerated catalyst reached 2.0430 mmol·g^-1, indicating that the main reason for resin catalyst deactivation is that Brønsted acid sites of original resin catalyst were temporarily replaced by non-hydrogen ion cations. A separation process consisting of extraction and distillation for PODE_3-6 product was designed for separation of water and unreacted formaldehyde from reactive mixture and purification of PODE_3-6, respectively. The concentration of PODE_3-6 in final product can reach up to 97%. These results indicate that the scale-up production of PODE_3-6 from methanol and formaldehyde solution is feasible.

Keywords: Inactivation, polyoxymethylene dimethyl ethers, separation process, sulfonic cation exchange resin.

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Authors: O. Sotolongo-Grau, D. Rodriguez-Perez, J. A. Santos-Miranda, M. M. Desco, O. Sotolongo-Costa, J. C. Antoranz

Abstract:

The use of the oncologic index ISTER allows for a more effective planning of the radiotherapic facilities in the hospitals. Any change in the radiotherapy treatment, due to unexpected stops, may be adapted by recalculating the doses to the new treatment duration while keeping the optimal prognosis. The results obtained in a simulation model on millions of patients allow the definition of optimal success probability algorithms.

Keywords: Mathematical model, radiation oncology, dynamical systems applications.

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Authors: Volodymyr Chegel

Abstract:

The computer modeling is carried out for parameter of sensitivity of optoelectronic chemical and biosensors, using phenomena of surface plasmon resonance (SPR). The physical model of SPR-sensor-s is described with (or without) of modifications of sensitive gold film surface by a dielectric layer. The variants of increasing of sensitivity for SPR-biosensors, constructed on the principle gold – dielectric – biomolecular layer are considered. Two methods of mathematical treatment of SPR-curve are compared – traditional, with estimation of sensor-s response as shift of the SPRcurve minimum and proposed, for system with dielectric layer, using calculating of the derivative in the point of SPR-curve half-width.

Keywords: Surface Plasmon Resonance, modeling, sensitivity, biosensor

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Authors: Lei Wang, Sizong Guo

Abstract:

In this paper, we study the numerical method for solving second-order fuzzy differential equations using Adomian method under strongly generalized differentiability. And, we present an example with initial condition having four different solutions to illustrate the efficiency of the proposed method under strongly generalized differentiability.

Keywords: Fuzzy-valued function, fuzzy initial value problem, strongly generalized differentiability, adomian decomposition method.

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Authors: M. Sivaiah, R. Parmar, S. K. Majumder

Abstract:

This article reports on hydrodynamic, mass transfer performances of fine bubble in a modified reactor. The quality of mixing in the modified reactor is discussed in the paper. Mass transfer efficiency based on quality of mixing is enunciated. To interpret the gas phase volume fraction and the quality of mixing is the empirical models for the modified system are developed.

Keywords: Downflow, bubble, hydrodynamics, gas-liquid, mixing, mass transfer, gas holdup

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Authors: Amir Shafeeq, Ayyaz Muhammad, Waqas Sarfraz, Ali Toqeer, Shazib Rashid, M. K. Rafiq

Abstract:

The current work focuses on rephrasing the harmful effects of mercury that is being released from a number of sources. Most of the sources are from the industrial waste water. Different techniques of mercury removal have been discussed and a brief comparison among these has been made. The experimental work has been conducted for two most widely used methods of mercury removal and comparison in terms of their efficiency has been made.

Keywords: Mercury, Waste Water, Adsorption.

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Authors: T. Abdelkrim, K. Benamrane, B. Bezza, Aeh Benkhelifa, A. Borni

Abstract:

This paper proposes a regulation method of back-to-back connected three-level converters in order to reduce the torque ripple in induction motor. First part is dedicated to the presentation of the feedback control of three-level PWM rectifier. In the second part, three-level NPC voltage source inverter balancing DC bus algorithm is presented. A theoretical analysis with a complete simulation of the system is presented to prove the excellent performance of the proposed technique.

Keywords: Back-to-back connection, Feedback control, Neutral-point balance, Three-level converter, Torque ripple.

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Authors: Mauricio Pe˜na, Adriana Luna, Carol Rodr´ıguez

Abstract:

In the following article we begin from a multi-parameter unstable nonlinear model of a Quadrotor. We design a control to stabilize and assure the attitude of the device, starting off a linearized system at the equilibrium point of the null angles of Euler (hover), which provides us a control with limited capacities at small angles of rotation of the vehicle in three dimensions. In order to clear this obstacle, we propose the identification of models in different angles by means of simulations and the design of a controller specifically implemented for the identification task, that in future works will allow the development of controllers according to fast and agile angles of Euler for Quadrotor.

Keywords: Quadrotor, model, control, identification.

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Authors: Damien Gondre, Hatem Ben Maad, Abdelkrim Trabelsi, Frédéric Kuznik, Joseph Virgone

Abstract:

The use of a radiant cooling solution would enable to lower cooling needs which is of great interest when the demand is initially high (hot climate). But, radiant systems are not naturally compatibles with humid climates since a low-temperature surface leads to condensation risks as soon as the surface temperature is close to or lower than the dew point temperature. A radiant cooling system combined to a dehumidification system would enable to remove humidity for the space, thereby lowering the dew point temperature. The humidity removal needs to be especially effective near the cooled surface. This requirement could be fulfilled by a system using a single desiccant fluid for the removal of both excessive heat and moisture. This task aims at providing an estimation of the specification requirements of such system in terms of cooling power and dehumidification rate required to fulfill comfort issues and to prevent any condensation risk on the cool panel surface. The present paper develops a preliminary study on the specification requirements, performances and behavior of a combined dehumidifier/cooling ceiling panel for different operating conditions. This study has been carried using the TRNSYS software which allows nodal calculations of thermal systems. It consists of the dynamic modeling of heat and vapor balances of a 5m x 3m x 2.7m office space. In a first design estimation, this room is equipped with an ideal heating, cooling, humidification and dehumidification system so that the room temperature is always maintained in between 21^◦C and 25^◦C with a relative humidity in between 40% and 60%. The room is also equipped with a ventilation system that includes a heat recovery heat exchanger and another heat exchanger connected to a heat sink. Main results show that the system should be designed to meet a cooling power of 42W.m⁻² and a desiccant rate of 45 g_H2O.h⁻¹. In a second time, a parametric study of comfort issues and system performances has been achieved on a more realistic system (that includes a chilled ceiling) under different operating conditions. It enables an estimation of an acceptable range of operating conditions. This preliminary study is intended to provide useful information for the system design.

Keywords: Dehumidification, nodal calculation, radiant cooling panel, system sizing.

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Authors: Mehrdad Mahdavi Boroujerdi, Soheil Nazem

Abstract:

Cloud Computing is a new technology that helps us to use the Cloud for compliance our computation needs. Cloud refers to a scalable network of computers that work together like Internet. An important element in Cloud Computing is that we shift processing, managing, storing and implementing our data from, locality into the Cloud; So it helps us to improve the efficiency. Because of it is new technology, it has both advantages and disadvantages that are scrutinized in this article. Then some vanguards of this technology are studied. Afterwards we find out that Cloud Computing will have important roles in our tomorrow life!

Keywords: Cloud Computing, Grid Computing, Internet as a Platform, On-demand Computing, Software as a Service.

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Authors: Babak Shamshiri, Najme Dastouri

Abstract:

The purpose of this study is to understand the current situation of happiness in the Iranian educational system from the perspective of students, teachers and educational administrators. This research is done in qualitative paradigm. Data collection is done by in-depth interview method. Research participants were selected purposively according to sampling rules, with maximum variation and reaching the saturation point. According to most participants in this study, schools in Iran are not usually happy. This lack of happiness is associated with and related to the educational system, curriculum, teaching method, physical environment of schools and their facilities.

Keywords: Happiness, Iran, educational system, qualitative study.

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Authors: Masao Ohta, Yoshiyuki Higuchi

Abstract:

This study analyses store layout among the many factors that underlie supermarket store design, this; in terms of what to display in a shop and where to place the items. This report examines newly-opened stores and evaluates their interior shop floor layouts, which we then attempt to categorize by various styles. We then consider the interaction between shop floor layout and customer behavior from the perspective of the supermarket as the seller. At this point, we focus on the “store magnets"–the main sections within the shop likely to attract customers into the store.

Keywords: Supermarket Store Layout, Sales magnet, Customer Circulation Rate, Section Drop-by Rates.

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Authors: Abiodun M. Aibinu, Momoh J. E. Salami, Amir A. Shafie, Athaur Rahman Najeeb

Abstract:

The use of Inverse Discrete Fourier Transform (IDFT) implemented in the form of Inverse Fourier Transform (IFFT) is one of the standard method of reconstructing Magnetic Resonance Imaging (MRI) from uniformly sampled K-space data. In this tutorial, three of the major problems associated with the use of IFFT in MRI reconstruction are highlighted. The tutorial also gives brief introduction to MRI physics; MRI system from instrumentation point of view; K-space signal and the process of IDFT and IFFT for One and two dimensional (1D and 2D) data.

Keywords: Discrete Fourier Transform (DFT), K-space Data, Magnetic Resonance (MR), Spin, Windows.

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Authors: Imane El Karaoui, Mohammed Maaroufi, Hamid Chaikhy

Abstract:

Doubly Fed Induction Generator (DFIG) is one of the most reliable wind generator. Major problem in wind power generation is to generate Sinusoidal signal with very low THD on variable speed caused by inverter two levels used. This paper presents a multi-level inverter whose objective is to reduce the THD and the dimensions of the output filter. This work proposes a three-level NPC-type inverter, the results simulation are presented demonstrating the efficiency of the proposed inverter.

Keywords: DFIG, multilevel inverter, NPC inverter , THD, Induction machine.

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Authors: Hideyuki Shintani, Ichiro Koshijima

Abstract:

In Cyber Physical System (CPS), if there are a large number of persons in the process, a role of person in CPS might be different comparing with the one-man system. It is also necessary to consider how Human-in-The-Loop Cyber Physical Systems (HiTLCPS) ensure safety of each person in the loop process. In this paper, the authors discuss a system safety framework with an illustrative example with STAMP model to clarify what point for safety should be considered and what role of person in the should have.

Keywords: Cyber Physical System, Human-in-The-Loop, Safety, STAMP model.

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Authors: Ajay V. Kolhe, R. E. Shelke, S. S. Khandare

Abstract:

The use of biodiesel in conventional diesel engines results in substantial reduction of unburned hydrocarbon, carbon monoxide and particulate matters. The performance, emission and combustion characteristics of a single cylinder four stroke variable compression ratio engine when fueled with Karanja (Pongamia) methyl ester and its 10-50 % blends with diesel (on a volume basis) are investigated and compared with standard diesel. The suitability of karanja methyl ester as a biofuel has been established in this study. The useful brake power obtained is similar to diesel fuel for all loads. Experiment has been conducted at a fixed engine speed of 1500 rpm, variable load and at compression ratios of 17.5:1 and 18.5:1. The impact of compression ratio on fuel consumption, combustion pressures and exhaust gas emissions has been investigated and presented. Optimum compression ratio which gives best performance has been identified. The results indicate longer ignition delay, maximum rate of pressure rise, lower heat release rate and higher mass fraction burnt at higher compression ratio for pongamia oil methyl ester when compared to that of diesel. The brake thermal efficiency for pongamia oil methyl ester blends and diesel has been calculated and the blend B20 is found to give maximum thermal efficiency. The blends when used as fuel results in reduction of carbon monoxide, hydrocarbon and increase in nitrogen oxides emissions. PME as an oxygenated fuel generated more complete combustion, which means increased torque and power. This is also supported with higher thermal efficiencies of the PME blends. NO_x is slightly increased due to the higher combustion temperature and the presence of fuel oxygen with the blend at full load. PME as a new Biodiesel and its blends can be used in diesel engines without any engine modification.

Keywords: Variable compression ratio CI engine, performance, combustion, emissions, biodiesel.

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Authors: Liliana Zisu

Abstract:

The first and best known quantum protocol BB84, whose security is unconditional allows the transmission of a key with a length equal to that of the message. This key used with an encryption algorithm leads to an unbreakable cryptographic scheme. Despite advantages the protocol still can be improved in at least two aspects: its efficiency which is of about 50%, only half of the photons transmitted are used to create the encryption key and the second aspect refers to the communication that takes place on the classic channel, as it must be reduced or even eliminated. The paper presents a method that improves the two aspects of the BB84 protocol by using quantum memory and eight states of polarization. The implementation of both the proposed method and the BB84 protocol was done through a C# application.

Keywords: BB84, protocol, quantum cryptography, quantum key distribution.

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Authors: Hadi Barghlame, M. A. Lotfollahi-Yaghin

Abstract:

In this paper, the torsion capacity of ultimate point on rectangular beams with spiral reinforcements in the torsion direction and its anti-direction are investigated. Therefore, models of above-mentioned beams have been numerically analyzed under various loads using ANSYS software. It was observed that, spirallyreinforced prismatic beam and beam with spiral links, show lower torsion capacity than beam with normal links also in anti-direction. The result is that the concrete regulations are violated in this case.

Keywords: RC beam, ultimate torsion, finite element, prismatic beams, spirally tie.

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Authors: Kazuaki Maeda

Abstract:

This paper proposes a new technique to detect code clones from the lexical and syntactic point of view, which is based on PALEX source code representation. The PALEX code contains the recorded parsing actions and also lexical formatting information including white spaces and comments. We can record a list of parsing actions (shift, reduce, and reading a token) during a compiling process after a compiler finishes analyzing the source code. The proposed technique has advantages for syntax sensitive approach and language independency.

Keywords: Code Clones, Source Code Representation, XML, Parser, Parser Generator

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Authors: Abdullah E. Al-Mazrooei

Abstract:

In this paper, we present a new kind of the bilinear systems in the form of state space model. The evolution of this system depends on the product of state vector by its self. The well known Lotak Volterra and Lorenz models are special cases of this new model. We also present here a generalization of Kalman filter which is suitable to work with the new bilinear model. An application to real measurements is introduced to illustrate the efficiency of the proposed algorithm.

Keywords: Bilinear systems, state space model, Kalman filter.

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Authors: Niramol Juntarachat, Romain Privat, Jean-Noël Jaubert

Abstract:

In this paper, vapour-liquid critical locus for the binary system acetone + chloroform was determined experimentally over the whole range of composition. The critical property measurements were carried out using a dynamic-synthetic apparatus, employed in the dynamic mode. The critical points are visually determined by observing the critical opalescence and the simultaneous disappearance and reappearance of the meniscus in the middle of a high-pressure view cell which withstands operations up to 673K and 20MPa. The experimental critical points measured in this work were compared to those available in literature.

Keywords: Experimental measurement, critical point, critical locus, negative azeotrope.

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Authors: Lidia Obojska

Abstract:

This paper has, as its point of departure, the foundational axiomatic theory of E. De Giorgi (1996, Scuola Normale Superiore di Pisa, Preprints di Matematica 26, 1), based on two primitive notions of quality and relation. With the introduction of a unary relation, we develop a system totally based on the sole primitive notion of relation. Such a modification enables a definition of the concept of dynamic unary relation. In this way we construct a simple language capable to express other well known theories such as Robinson-s arithmetic or a piece of a theory of concatenation. A key role in this system plays an abstract relation designated by “( )", which can be interpreted in different ways, but in this paper we will focus on the case when we can perform computations and obtain results.

Keywords: language, unary relations, arithmetic, computability

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Authors: Nicolas Zufferey

Abstract:

The vehicle routing problem (VRP) is a famous combinatorial optimization problem. Because of its well-known difficulty, metaheuristics are the most appropriate methods to tackle large and realistic instances. The goal of this paper is to highlight the key ideas for designing VRP metaheuristics according to the following criteria: efficiency, speed, robustness, and ability to take advantage of the problem structure. Such elements can obviously be used to build solution methods for other combinatorial optimization problems, at least in the deterministic field.

Keywords: Vehicle routing problem, Metaheuristics, Combinatorial optimization.

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Authors: Seongchan Kang, Hongsik Yun, Hyukgil Kim, Minwoo Park

Abstract:

For this study, this researcher conducted a precision network adjustment with QOCA, the precision network adjustment software developed by Jet Propulsion Laboratory, to perform an integrated network adjustment on the Unified Control Points managed by the National Geographic Information Institute. Towards this end, 275 Unified Control Points observed in 2008 were selected before a network adjustment is performed on those 275 Unified Control Points. The RMSE on the discrepancies of coordinates as compared to the results of GLOBK was ±6.07mm along the N axis, ±2.68mm along the E axis and ±6.49mm along the U axis.

Keywords: Network adjustment, QOCA, unified control point.

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Authors: M. Kubeitari, A. Alhusayn, M. Alnahar

Abstract:

Space Vector Pulse Width Modulation SVPWM is one of the most used techniques to generate sinusoidal voltage and current due to its facility and efficiency with low harmonics distortion. This algorithm is specially used in power electronic applications. This paper describes simulation algorithm of SVPWM & SPWM using MatLab/simulink environment. It also implements a closed loop three phases DC-AC converter controlling its outputs voltages amplitude and frequency using MatLab. Also comparison between SVPWM & SPWM results is given.

Keywords: DC-AC Converter, MatLab, SPWM, SVPWM, Vref - rotating frame.

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Authors: Talib Hashim Hasan

Abstract:

This paper describes simple implementation of homotopy (also called continuation) algorithm for determining the proper resistance of the resistor to dissipate energy at a specified rate of an electric circuit. Homotopy algorithm can be considered as a developing of the classical methods in numerical computing such as Newton-Raphson and fixed point methods. In homoptopy methods, an embedding parameter is used to control the convergence. The method purposed in this work utilizes a special homotopy called Newton homotopy. Numerical example solved in MATLAB is given to show the effectiveness of the purposed method

Keywords: electrical circuit homotopy, methods, MATLAB, Newton homotopy

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