In this paper we analyzed the performance of Aggressive Packet Combining (APC) scheme. Various researchers have already suggested some protocols or schemes for the improvement of performance and correction capability ...
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ISBN:
(纸本)9781479980826
In this paper we analyzed the performance of Aggressive Packet Combining (APC) scheme. Various researchers have already suggested some protocols or schemes for the improvement of performance and correction capability of APC. Here we proposed four new protocols for improving the correction capability of APC. The four new protocols have been studied numerically and presented in this paper.
作者：
Yousra AbudaqqaAhmed PatelaSchool of Computer Science
Centre of Software Technology and Management (SOFTAM) Faculty of Information Science and Technology (FTSM) Universiti Kebangsaan Malaysia 43600 UKM Bangi Selangor Malaysia bSchool of Computer Science
Centre of Software Technology and Management (SOFTAM) Faculty of Information Science and Technology (FTSM) Universiti Kebangsaan Malaysia 43600 UKM Bangi Selangor Malaysia cVisiting Professor School of Computing and Information Systems
Faculty of Science Engineering and Computing Kingston University Kingston upon Thames KT1 2EE United Kingdom
Indisputably, search engines (SEs) abound. The monumental growth of users performing online searches on the Web is a contending issue in the contemporary world nowadays. For example, there are tens of billions of sear...
Indisputably, search engines (SEs) abound. The monumental growth of users performing online searches on the Web is a contending issue in the contemporary world nowadays. For example, there are tens of billions of searches performed everyday, which typically offer the users many irrelevant results which are time consuming and costly to the user. Based on the afore-going problem it has become a herculean task for existing Web SEs to provide complete, relevant and up-to-date information response to users’ search queries. To overcome this problem, we developed the Distributed Search Engine Architecture (DSEA), which is a new means of smart information query and retrieval of the World Wide Web (WWW). In DSEAs, multiple autonomous search engines, owned by different organizations or individuals, cooperate and act as a single search engine. This paper includes the work reported in this research focusing on development of DSEA, based on topic-specific specialised search engines. In DSEA, the results to specific queries could be provided by any of the participating search engines, for which the user is unaware of. The important design goal of using topic-specific search engines in the research is to build systems that can effectively be used by larger number of users simultaneously. Efficient and effective usage with good response is important, because it involves leveraging the vast amount of searched data from the World Wide Web, by categorising it into condensed focused topic -specific results that meet the user’s queries. This design model and the development of the DSEA adopt a Service Directory (SD) to route queries towards topic-specific document hosting SEs. It displays the most acceptable performance which is consistent with the requirements of the users. The evaluation results of the model return a very high priority score which is associated with each frequency of a keyword.
作者：
H. TourajizadehS. ManteghiS. R. NekooAssistant professor
Department of Mechanical Engineering Faculty of Engineering Kharazmi University Tehran Iran M. Sc.
College of Computer and Mechatronics Engineering Islamic Azad University Branch of Science and Research Tehran Iran PhD Student
School of Mechanical Engineering Iran University of Science and Technology (IUST) Tehran Iran
In this paper, parametric and numerical model of the motors of a robot are extracted. A method is proposed here to control the torque and velocity of the motor simultaneously using the extracted dynamics of the motor ...
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ISBN:
(纸本)9781467372350
In this paper, parametric and numerical model of the motors of a robot are extracted. A method is proposed here to control the torque and velocity of the motor simultaneously using the extracted dynamics of the motor and consequently control the robot motion more accurately. Parametric model of the motors are derived by conducting standard tests like locked rotor test and step and sine wave input test. In order to derive the neural network and numerical models, a set of sinusoidal, triangular, and random steps signal, are applied as the input to the motor and its speed is recorded as the output. Neural network model of the motors is extracted by using these dataset and considering the MLP neural network structure with Levenberg _Marquardt training method. Results of the numerical model and parametric models are compared and validated by experimental tests.
In this paper,we present a hybrid method,which integrates PIC/FLIP and vortex particle methods into a unified framework,to efficiently simulate vortex shedding that happens when fluids flow around internal *** improve...
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In this paper,we present a hybrid method,which integrates PIC/FLIP and vortex particle methods into a unified framework,to efficiently simulate vortex shedding that happens when fluids flow around internal *** improve efficiency and reduce the numerical dissipations,we first solve the governing equations on a coarse grid using PIC/FLIP,and then interpolate the intermediate results to a finer grid to obtain the base *** the regular particles in PIC/FLIP enter the boundary layer,if the specified conditions are satisfied to cause vortex shedding,they are selected as vortex particles by assigning additional vorticity related *** vortex particle dynamics are controlled by the vorticity form of NS equations,and several efficient methods are proposed to solve them on the finer ***,the obtained turbulence flow is added to the base *** a result,we are able to simulate turbulent water with rich wake details around the internal obstacles.
A torque estimation method with adaptive robustness and optimality adjustment according to the load for modular and reconfigurable robot joint with harmonic drive transmission is proposed, on the basis of harmonic dri...
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A torque estimation method with adaptive robustness and optimality adjustment according to the load for modular and reconfigurable robot joint with harmonic drive transmission is proposed, on the basis of harmonic drive compliance model and redundant adaptive robust extended Kalman filter (RAREKF). The proposed approach can adapt torque estimation filtering optimality and robustness to the load variations by self-tuning the filtering gain and self-switching the filtering modes between optimal and robust. The redundant factor of RAREKF is designed as a function of the load to provide desirable tolerant capability to the modeling error and load-dependent filtering mode switching. The proposed joint torque estimation method has been experimentally studied in comparison with a commercial sensor, and the results have demonstrated the effectiveness of the proposed torque estimation technique.
Thresholding-based techniques have been widely used in image segmentation. The selection of appropriate threshold is a very significant issue for image thresholding. In this paper, a new image histogram thresholding m...
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Thresholding-based techniques have been widely used in image segmentation. The selection of appropriate threshold is a very significant issue for image thresholding. In this paper, a new image histogram thresholding method based on fuzzy partition and maximum correlation criterion is presented. In the proposed approach, the regions, i.e. object and background, are considered ambiguous in nature, and hence the regions are transformed into fuzzy domain with membership functions. Then, the fuzzy correlations about regions are constructed and the optimal threshold is determined by searching an optimal parameter combination of the membership functions such that the correlation of the fuzzy partitions is maximized. Since the exhaustive search for all fuzzy parameter combinations is too costly, the differential evolution algorithm is introduced into fuzzy correlation image segmentation to solve this optimal problem adaptively. Experimental results on general images and infrared images demonstrate the effectiveness of the proposed method.
As the next generation of networking computing, cloud computing can offer both software and hardware as on-demand resources and services over the Internet and therefore reduce the capital expenditure and operational e...
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In this paper, Gas-liquid two phase flow mathematic models of incompressible fluid were proposed to explore the feature of fluid under certain centrifugal force in vertical centrifugal casting (VCC). Modified projecti...
In this paper, Gas-liquid two phase flow mathematic models of incompressible fluid were proposed to explore the feature of fluid under certain centrifugal force in vertical centrifugal casting (VCC). Modified projection-level-set method was introduced to solve the mathematic models. To validate the simulation results, two methods were used in this study. In the first method, the simulation result of basic VCC flow process was compared with its analytic solution. The relationship between the numerical solution and deterministic analytic solution was presented to verify the correctness of numerical algorithms. In the second method, systematic water simulation experiments were developed. In this initial experiment, special experimental vertical centrifugal device and casting shapes were designed to describe typical mold-filling processes in VCC. High speed camera system and data collection devices were used to capture flow shape during the mold-filling process. Moreover, fluid characteristic at different rotation speed (from 40rpm, 60rpmand 80rpm) was discussed to provide comparative resource for simulation results. As compared with the simulation results, the proposed mathematical models could be proven and the experimental design could help us advance the accuracy of simulation and further studies for VCC.
The research on the simulation for the through process of low-pressure casting and heat treatment is conducive to combine information technology and advanced casting technology, which will help to predict the defects ...
The research on the simulation for the through process of low-pressure casting and heat treatment is conducive to combine information technology and advanced casting technology, which will help to predict the defects and mechanical properties of the castings in the through process. In this paper, we focus on the simulation for through process of low-pressure casting and heat treatment of ZL114A Bending beam. Firstly, we analyzethe distribution of the shrinkage and porosities in filling and solidification process, and simulate the distribution of stress and strain in the late solidification of casting. Then, the numerical simulation of heat treatment process for ZL114A Bending beam is realized according to the heat treatment parameters and the corresponding simulation results of temperature field, stress, strain, and aging performance are given. Finally, we verify that simulation platform for the through process of low-pressure casting and heat treatment can serve the production practice perfectly and provide technical guidance and process optimization for the through process of low-pressure casting and heat treatment.
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