期刊文献+
共找到199篇文章
< 1 2 10 >
每页显示 20 50 100
IMPLEMENTATION AND PERFORMANCE ANALYSIS OF ACCURATE LOCALIZATION OF SHORT-RANGE TARGETS BASED ON MULTISENSOR SYSTEMS
1
作者 尹成友 徐善驾 王东进 《Chinese Journal of Aeronautics》 SCIE EI CAS CSCD 1999年第2期31-37,共7页
In this paper, the optimal estimate method is systematically investigated for estimating the position and velocity vectors of a short range target in space with a multisensor system TR n (one transmitting sensor... In this paper, the optimal estimate method is systematically investigated for estimating the position and velocity vectors of a short range target in space with a multisensor system TR n (one transmitting sensor and n receiving sensors). A suboptimal and realizable signal processing scheme is provided. The performance of the suboptimal procedure is analyzed theoretically in detail, and analytical expressions are obtained for the covariance matrix of the estimator error. Simulation results verify the theoretical prediction, which demonstrates the system is able to accurately locate a short range target. 展开更多
关键词 multisensor system state estimation performance analysis suboptimal implementation
下载PDF
Configuration Synthesis and Grasping Performance Analysis of Multi-Loop Coupling Capture Mechanism for Launch and Recovery of Torpedo-Shaped Autonomous Underwater Vehicle
2
作者 ZHANG Guo-xing XIA Xin-lu GUO Jin-wei 《China Ocean Engineering》 SCIE EI CSCD 2024年第3期453-466,共14页
Research of capture mechanisms with strong capture adaptability and stable grasp is important to solve the problem of launch and recovery of torpedo-shaped autonomous underwater vehicles(AUVs).A multi-loop coupling ca... Research of capture mechanisms with strong capture adaptability and stable grasp is important to solve the problem of launch and recovery of torpedo-shaped autonomous underwater vehicles(AUVs).A multi-loop coupling capture mechanism with strong adaptability and high retraction rate has been proposed for the launch and recovery of torpedo-shaped AUVs with different morphological features.Firstly,the principle of capturing motion retraction is described based on the appearance characteristics of torpedo-shaped AUVs,and the configuration synthesis of the capture mechanism is carried out using the method of constrained chain synthesis.Secondly,the screw theory is employed to analyze the degree of freedom(DoF)of the capture mechanism.Then,the 3D model of the capture mechanism is established,and the kinematics and dynamics simulations are carried out.Combined with the capture orientation requirements of the capture mechanism,the statics and vibration characteristics analyses are carried out.Furthermore,considering the capture process and the underwater working environment,the motion characteristics and hydraulics characteristics of the capture mechanism are analyzed.Finally,a principle prototype is developed and the torpedo-shaped AUVs capture experiment is completed.The work provides technical reserves for the research and development of AUV capture special equipment. 展开更多
关键词 capture mechanism torpedo-shaped AUVs configuration synthesis launch and recovery grasping performance analysis
下载PDF
Performance Analysis and Optimization of Energy Harvesting Modulation for Multi-User Integrated Data and Energy Transfer
3
作者 Yizhe Zhao Yanliang Wu +1 位作者 Jie Hu Kun Yang 《China Communications》 SCIE CSCD 2024年第1期148-162,共15页
Integrated data and energy transfer(IDET)enables the electromagnetic waves to transmit wireless energy at the same time of data delivery for lowpower devices.In this paper,an energy harvesting modulation(EHM)assisted ... Integrated data and energy transfer(IDET)enables the electromagnetic waves to transmit wireless energy at the same time of data delivery for lowpower devices.In this paper,an energy harvesting modulation(EHM)assisted multi-user IDET system is studied,where all the received signals at the users are exploited for energy harvesting without the degradation of wireless data transfer(WDT)performance.The joint IDET performance is then analysed theoretically by conceiving a practical time-dependent wireless channel.With the aid of the AO based algorithm,the average effective data rate among users are maximized by ensuring the BER and the wireless energy transfer(WET)performance.Simulation results validate and evaluate the IDET performance of the EHM assisted system,which also demonstrates that the optimal number of user clusters and IDET time slots should be allocated,in order to improve the WET and WDT performance. 展开更多
关键词 energy harvesting modulation(EHM) integrated data and energy transfer(IDET) performance analysis wireless data transfer(WDT) wireless energy transfer(WET)
下载PDF
Python Server Page Performance Analysis and Modeling
4
作者 Razafindraibe Marolahy Alix Randrianomenjanahary Lala Ferdinand +2 位作者 Rafamantanantsoa Fontaine Mahatody Thomas F. Angelo Raherinirina 《Communications and Network》 2024年第1期1-30,共30页
Today, in the field of computer networks, new services have been developed on the Internet or intranets, including the mail server, database management, sounds, videos and the web server itself Apache. The number of s... Today, in the field of computer networks, new services have been developed on the Internet or intranets, including the mail server, database management, sounds, videos and the web server itself Apache. The number of solutions for this server is therefore growing continuously, these services are becoming more and more complex and expensive, without being able to fulfill the needs of the users. The absence of benchmarks for websites with dynamic content is the major obstacle to research in this area. These users place high demands on the speed of access to information on the Internet. This is why the performance of the web server is critically important. Several factors influence performance, such as server execution speed, network saturation on the internet or intranet, increased response time, and throughputs. By measuring these factors, we propose a performance evaluation strategy for servers that allows us to determine the actual performance of different servers in terms of user satisfaction. Furthermore, we identified performance characteristics such as throughput, resource utilization, and response time of a system through measurement and modeling by simulation. Finally, we present a simple queue model of an Apache web server, which reasonably represents the behavior of a saturated web server using the Simulink model in Matlab (Matrix Laboratory) and also incorporates sporadic incoming traffic. We obtain server performance metrics such as average response time and throughput through simulations. Compared to other models, our model is conceptually straightforward. The model has been validated through measurements and simulations during the tests that we conducted. 展开更多
关键词 performance analysis QUEUE performance Model Web Server Internet World Wide Web Web Server performance
下载PDF
Optimization and Performance Analysis of Intelligent Video AI Dynamic
5
作者 Yu Xing 《Journal of Electronic Research and Application》 2024年第3期142-147,共6页
In today’s information age,video data,as an important carrier of information,is growing explosively in terms of production volume.The quick and accurate extraction of useful information from massive video data has be... In today’s information age,video data,as an important carrier of information,is growing explosively in terms of production volume.The quick and accurate extraction of useful information from massive video data has become a focus of research in the field of computer vision.AI dynamic recognition technology has become one of the key technologies to address this issue due to its powerful data processing capabilities and intelligent recognition functions.Based on this,this paper first elaborates on the development of intelligent video AI dynamic recognition technology,then proposes several optimization strategies for intelligent video AI dynamic recognition technology,and finally analyzes the performance of intelligent video AI dynamic recognition technology for reference. 展开更多
关键词 Intelligent video AI dynamic recognition Technology optimization performance analysis
下载PDF
Performance analysis of quantum key distribution using polarized coherent-states in free-space channel 被引量:1
6
作者 郑增特 陈子扬 +2 位作者 黄露雨 王翔宇 喻松 《Chinese Physics B》 SCIE EI CAS CSCD 2023年第3期111-119,共9页
In free space channel,continuous-variable quantum key distribution(CV-QKD)using polarized coherent-states can not only make the signal state more stable and less susceptible to interference based on the polarization n... In free space channel,continuous-variable quantum key distribution(CV-QKD)using polarized coherent-states can not only make the signal state more stable and less susceptible to interference based on the polarization non-sensitive of the free-space channel,but also reduce the noise introduced by phase interference.However,arbitrary continuous modulation can not be carried out in the past polarization coding,resulting in that the signal state can not obtain arbitrary continuous value in Poincare space,and the security analysis of CV-QKD using polarized coherent-states in free space is not complete.Here we propose a new modulation method to extend the modulation range of signal states with an optical-fiber-based polarization controller.In particular,in terms of the main influence factors in the free-space channel,we utilize the beam extinction and elliptical model when considering the transmittance and adopt the formulation of secret key rate.In addition,the performance of the proposed scheme under foggy weather is also taken into consideration to reveal the influence of severe weather.Numerical simulation shows that the proposed scheme is seriously affected by attenuation under foggy weather.The protocol fails when visibility is less than 1 km.At the same time,the wavelength can affect the performance of the proposed scheme.Specifically,under foggy weather,the longer the wavelength,the smaller the attenuation coefficient,and the better the transmission performance.Our proposed scheme can expand the modulation range of signal state,and supplement the security research of the scheme in the free-space channel,thus can provide theoretical support for subsequent experiments. 展开更多
关键词 polarized coherent-states free-space channel performance analysis
下载PDF
Performance Analysis of the Packet-Based PNT Service in NGSO Broadband Satellite Communication Systems
7
作者 Xi Chen Qihui Wei +1 位作者 Yafeng Zhan Linling Kuang 《China Communications》 SCIE CSCD 2023年第9期247-259,共13页
Providing alternative PNT service to GNSS-challenged users will be an important function of next-generation NGSO broadband satellite communication systems.Herein,a packet-based PNT service architecture in NGSO broadba... Providing alternative PNT service to GNSS-challenged users will be an important function of next-generation NGSO broadband satellite communication systems.Herein,a packet-based PNT service architecture in NGSO broadband systems is proposed in which a primary satellite and selected assistant satellites work together to provide PNT service to requesting users.Its positioning performance bounds are mathematically formulated by rigorously analyzing the bounds constrained by different waveforms.Simulations are conducted on different configurations of Walker Delta MEO constellations and Walker Star LEO constellations for corroboration,revealing the following:(1)Both MEO and LEO constellations achieve sub-meter-level positioning precision given enough satellites.(2)Compared to the GNSS Doppler-based velocity estimation method,the position advance based velocity estimation algorithm is more precise and applicable to the PNT service in NGSO broadband systems.(3)To provide PNT service to users in GNSS-challenged environments,the primary and each assistant satellite need only∼0.1‰of the time of one downlink beam. 展开更多
关键词 6G non-terrestrial network NGSO satellite positioning performance analysis
下载PDF
Evolutionary Algorithm Based Feature Subset Selection for Students Academic Performance Analysis
8
作者 Ierin Babu R.MathuSoothana S.Kumar 《Intelligent Automation & Soft Computing》 SCIE 2023年第6期3621-3636,共16页
Educational Data Mining(EDM)is an emergent discipline that concen-trates on the design of self-learning and adaptive approaches.Higher education institutions have started to utilize analytical tools to improve student... Educational Data Mining(EDM)is an emergent discipline that concen-trates on the design of self-learning and adaptive approaches.Higher education institutions have started to utilize analytical tools to improve students’grades and retention.Prediction of students’performance is a difficult process owing to the massive quantity of educational data.Therefore,Artificial Intelligence(AI)techniques can be used for educational data mining in a big data environ-ment.At the same time,in EDM,the feature selection process becomes necessary in creation of feature subsets.Since the feature selection performance affects the predictive performance of any model,it is important to elaborately investigate the outcome of students’performance model related to the feature selection techni-ques.With this motivation,this paper presents a new Metaheuristic Optimiza-tion-based Feature Subset Selection with an Optimal Deep Learning model(MOFSS-ODL)for predicting students’performance.In addition,the proposed model uses an isolation forest-based outlier detection approach to eliminate the existence of outliers.Besides,the Chaotic Monarch Butterfly Optimization Algo-rithm(CBOA)is used for the selection of highly related features with low com-plexity and high performance.Then,a sailfish optimizer with stacked sparse autoencoder(SFO-SSAE)approach is utilized for the classification of educational data.The MOFSS-ODL model is tested against a benchmark student’s perfor-mance data set from the UCI repository.A wide-ranging simulation analysis por-trayed the improved predictive performance of the MOFSS-ODL technique over recent approaches in terms of different measures.Compared to other methods,experimental results prove that the proposed(MOFSS-ODL)classification model does a great job of predicting students’academic progress,with an accuracy of 96.49%. 展开更多
关键词 Students’performance analysis educational data mining feature selection deep learning metaheuristics outlier detection
下载PDF
A CSMA/CA based MAC protocol for hybrid Power-line/Visible-light communication networks:Design and analysis
9
作者 Sheng Hao Huyin Zhang +2 位作者 Fei Yang Chenghao Li Jing Wang 《Digital Communications and Networks》 SCIE CSCD 2024年第2期481-497,共17页
Hybrid Power-line/Visible-light Communication(HPVC)network has been one of the most promising Cooperative Communication(CC)technologies for constructing Smart Home due to its superior communication reliability and har... Hybrid Power-line/Visible-light Communication(HPVC)network has been one of the most promising Cooperative Communication(CC)technologies for constructing Smart Home due to its superior communication reliability and hardware efficiency.Current research on HPVC networks focuses on the performance analysis and optimization of the Physical(PHY)layer,where the Power Line Communication(PLC)component only serves as the backbone to provide power to light Emitting Diode(LED)devices.So designing a Media Access Control(MAC)protocol remains a great challenge because it allows both PLC and Visible Light Communication(VLC)components to operate data transmission,i.e.,to achieve a true HPVC network CC.To solve this problem,we propose a new HPC network MAC protocol(HPVC MAC)based on Carrier Sense Multiple Access/Collision Avoidance(CSMA/CA)by combining IEEE 802.15.7 and IEEE 1901 standards.Firstly,we add an Additional Assistance(AA)layer to provide the channel selection strategies for sensor stations,so that they can complete data transmission on the selected channel via the specified CSMA/CA mechanism,respectively.Based on this,we give a detailed working principle of the HPVC MAC,followed by the construction of a joint analytical model for mathematicalmathematical validation of the HPVC MAC.In the modeling process,the impacts of PHY layer settings(including channel fading types and additive noise feature),CSMA/CA mechanisms of 802.15.7 and 1901,and practical configurations(such as traffic rate,transit buffer size)are comprehensively taken into consideration.Moreover,we prove the proposed analytical model has the solvability.Finally,through extensive simulations,we characterize the HPVC MAC performance under different system parameters and verify the correctness of the corresponding analytical model with an average error rate of 4.62%between the simulation and analytical results. 展开更多
关键词 Hybrid power-line/Visible light communication (HPVC)networks MAC protocol CSMA/CA IEEE 802.15.7 IEEE 1901 performance analysis
下载PDF
SIMULATION AND PERFORMANCE ANALYSIS OF NETWORK ON CHIP ARCHITECTURES 被引量:1
10
作者 葛芬 吴宁 《Transactions of Nanjing University of Aeronautics and Astronautics》 EI 2010年第4期326-332,共7页
The network on chip(NoC)is used as a solution for the communication problems in a complex system on chip(SoC)design.To further enhance performances,the NoC architectures,a high level modeling and an evaluation met... The network on chip(NoC)is used as a solution for the communication problems in a complex system on chip(SoC)design.To further enhance performances,the NoC architectures,a high level modeling and an evaluation method based on OPNET are proposed to analyze their performances on different injection rates and traffic patterns.Simulation results for general NoC in terms of the average latency and the throughput are analyzed and used as a guideline to make appropriate choices for a given application.Finally,a MPEG4 decoder is mapped on different NoC architectures.Results prove the effectiveness of the evaluation method. 展开更多
关键词 microprocessor chips ARCHITECTURE network on chip system on chip performance analysis
下载PDF
A FLEXIBLE SIMULATION TOOL FOR PERFORMANCE ANALYSIS
11
作者 舒炎泰 张平 +3 位作者 张燕 费亚中 贾明珠 金志刚 《Transactions of Tianjin University》 EI CAS 1996年第2期37+33-36,共5页
This paper presents RTSS simulation software with the capability for graphical model building and animation display. The RTSS simulation software consists of three separated parts: the simulation kernel, the model bui... This paper presents RTSS simulation software with the capability for graphical model building and animation display. The RTSS simulation software consists of three separated parts: the simulation kernel, the model building program and the result post processing program. The RTSS may run in the client/server mode. The main features of the RTSS software are more modular, more flexible and easier to upgrade. RTSS is built on object oriented technology, so it has more flexibility. The RTSS model of a system is an open queueing network. For modeling various data acquisition systems, communication networks and flexible manufacturing systems at different abstraction levels, RTSS has proven to be an extremely useful tool for performance analysis. 展开更多
关键词 SIMULATION performance analysis QUEUEING
下载PDF
Performance analysis in 3G/ad hoc integrated network
12
作者 李旭杰 沈连丰 《Journal of Southeast University(English Edition)》 EI CAS 2011年第3期233-238,共6页
An analytical approach to evaluate the performance of the 3G/ad hoc integrated network is presented. A channel model capturing both path loss and shadowing is applied to the analysis so as to characterize power fallof... An analytical approach to evaluate the performance of the 3G/ad hoc integrated network is presented. A channel model capturing both path loss and shadowing is applied to the analysis so as to characterize power falloff vs. distance. The 3G/ad hoc integrated network scenario model is introduced briefly. Based on this model, several performances of the 3G/ ad hoc integrated network in terms of outage probability, call dropping probability and new call blocking probability are evaluated. The corresponding performance formulae are deduced in accordance with the analytical models. Meanwhile, the formula of the 3G/ad hoc integrated network capacity is deduced on the basis of the formula of the outage probability. It is observed from extensive simulation and numerical analysis that the 3G/ad hoc integrated network remarkably outperforms the 3G network with regards to the network performance. This derived evaluation approach can be applied into planning and optimization of the 3G/ad hoc network. 展开更多
关键词 performance analysis 3G network ad hoc network integrated network
下载PDF
PERFORMANCE ANALYSIS AND KINEMATIC DESIGN OF PURE TRANSLATIONAL PARALLEL MECHANISM WITH VERTICAL GUIDE-WAYS 被引量:10
13
作者 LI Jianfeng WANG Xinhua +2 位作者 FEI Renyuan LIU Dezhong FAN Jinhong 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2006年第2期300-306,共7页
Performance analysis and kinematic design of the 3-PUU pure translational parallel mechanism with vertical guide-ways are investigated. Two novel performance indices, the critical slider stroke and the main section ar... Performance analysis and kinematic design of the 3-PUU pure translational parallel mechanism with vertical guide-ways are investigated. Two novel performance indices, the critical slider stroke and the main section area of workspace, are defined; The expressions of two other indices, i.e. the global dexterity and global force transfer ratio are revised based on the main section of workspace. Using these indices, performance changes versus the varieties of dimensional parameters of mechanism are investigated in detail and the graphic descriptions of change tendencies of the performance indices are illustrated. By means of these obtained graphic descriptions, kinematic parameters for the 3-PUU pure translational parallel mechanism with better characteristics can be directly acquired. 展开更多
关键词 3-PUU pure translational parallel mechanism Vertical guide-way performance analysis Kinematic design
下载PDF
Power Allocation and Performance Analysis of the Collaborative NOMA Assisted Relaying Systems in 5G 被引量:8
14
作者 Xin Liu Xianbin Wang Yanan Liu 《China Communications》 SCIE CSCD 2017年第1期50-60,共11页
Serving multiple cell-edge mobile terminals poses multifaceted challenges due to the increased transmission power and interferences, which could be overcome by relay communications. With the recent advancement of 5G t... Serving multiple cell-edge mobile terminals poses multifaceted challenges due to the increased transmission power and interferences, which could be overcome by relay communications. With the recent advancement of 5G technologies, non-orthogonal multiple access(NOMA) has been used at relay node to transmit multiple messages simultaneously to multiple cell-edge users. In this paper, a Collaborative NOMA Assisted Relaying(CNAR) system for 5G is proposed by enabling the collaboration of source-relay(S-R) and relay-destination(R-D) NOMA links. The relay node of the CNAR decodes the message for itself from S-R NOMA signal and transmits the remaining messages to the multiple cell-edge users in R-D link. A simplified-CNAR(S-CNAR) system is then developed to reduce the relay complexity. The outage probabilities for both systems are analyzed by considering outage behaviors in S-R and R-D links separately. To guarantee the data rate, the optimal power allocation among NOMA users is achieved by minimizing the outage probability. The ergodic sum capacity in high SNR regime is also approximated. Our mathematical analysis and simulation results show that CNAR system outperforms existing transmission strategies and S-CNAR reaches similar performance with much lower complexity. 展开更多
关键词 5G NOMA RELAYING performance analysis power allocation
下载PDF
Non-linear performance analysis and voltage control of MFC based on feedforward fuzzy logic PID strategy 被引量:8
15
作者 LUO Qing-zhu AN Ai-min +1 位作者 ZHANG Hao-chen MENG Fan-cheng 《Journal of Central South University》 SCIE EI CAS CSCD 2019年第12期3359-3371,共13页
Microbial fuel cell(MFC)is a kind of promising clean power supply energy equipment,but serious nonlinearities and disturbances exist when the MFC runs,and it is an important topic to guarantee that the output voltage ... Microbial fuel cell(MFC)is a kind of promising clean power supply energy equipment,but serious nonlinearities and disturbances exist when the MFC runs,and it is an important topic to guarantee that the output voltage reaches the setting value quickly and smoothly.Regulating the feeding flow is an effective way to achieve this goal,and especially,the satisfactory results can be achieved by regulating anode feeding flow.In this work,a feedforward fuzzy logic PID algorithm is proposed.The fuzzy logic system is introduced to deal with the non-linear dynamics of MFC,and corresponding PID parameters are calculated according to defuzzification.The magnitude value of the current density is used to simulate the value of the external load.The simulation results indicate that the MFC output voltage can track the setting value quickly and smoothly with the proposed feedforward fuzzy logic PID algorithm.The proposed algorithm is more efficient and robust with respect to anti-disturbance performance and tracking accuracy than other three control methods. 展开更多
关键词 microbial fuel cell feedforward fuzzy logic PID nonlinear performance analysis output voltage tracking
下载PDF
Performance analysis and optimal design for well patterns in anisotropic formations 被引量:6
16
作者 Liu Yuetian 《Petroleum Science》 SCIE CAS CSCD 2008年第3期251-257,共7页
The mechanism of the effects of anisotropic permeability on well patterns and reservoir development are investigated by coordinate transformation, fluid flow analysis, and reservoir development concepts. Anisotropy of... The mechanism of the effects of anisotropic permeability on well patterns and reservoir development are investigated by coordinate transformation, fluid flow analysis, and reservoir development concepts. Anisotropy of permeability has reconstructive effects on well patterns. The originally designed flooding units are broken up, and new pattern units are made up of the wells that belong to different original units. The behavior possesses strong randomness, and leads to a complicated relationship among the injection and production wells, and unpredictable productivity of the formations. To prevent the break-up of well patterns, well lines should be either parallel or perpendicular to the maximum principal direction of the anisotropic permeability (i.e. the fracture direction). To optimize the development effects ofanisotropic formations, the latitudinal and longitudinal well spacing of the well network are calculated from the principal values of the anisotropic permeability. 展开更多
关键词 Fractured reservoir anisotropic permeability performance analysis well pattern design
下载PDF
Performance analysis of an O_2/ CO_2 power plant based on chemical looping air separation
17
作者 顾鹏飞 向文国 《Journal of Southeast University(English Edition)》 EI CAS 2015年第2期194-199,共6页
The process of an O2//CO2 power plant based on chemical looping air separation (CLAS) is modeled using the Aspen Plus software. The operating parameters and power consumption of the CLAS unit are analyzed. The CLAS ... The process of an O2//CO2 power plant based on chemical looping air separation (CLAS) is modeled using the Aspen Plus software. The operating parameters and power consumption of the CLAS unit are analyzed. The CLAS system, thermal power generation system and flue gas cooling and compression unit (CCU) are coupled and optimized, and the temperature and flow of the flue gas extraction are determined. The results indicate that the net plant efficiency of CLAS O2/CO2 power plant is 39.2%, which is only 3.54% lower than that of the conventional power plants without carbon capture. However, the O2/CO2 power plant based on cryogenic air separation technology brings 8% to 10% decrease in the net plant efficiency. By optimizations, the net plant efficiency increases by 1.65%. The energy consumption of the CCU accounts for 59.7% and the pump accounts for 27.1%. The oxygen concentration from the chemical looping air separation unit is 12.2%. 展开更多
关键词 chemical looping air separation O2/CO2 combustion performance analysis
下载PDF
Performance analysis model for real-time Ethernet-based computer numerical control system 被引量:2
18
作者 万加富 李迪 +1 位作者 涂钰青 张春华 《Journal of Central South University》 SCIE EI CAS 2011年第5期1545-1553,共9页
In order to optimize the embedded system implementation for Ethernet-based computer numerical control (CNC) system, it is very necessary to establish the performance analysis model and further adopt the codesign met... In order to optimize the embedded system implementation for Ethernet-based computer numerical control (CNC) system, it is very necessary to establish the performance analysis model and further adopt the codesign method from the control, communication and computing perspectives. On the basis of analyzing real-time Ethemet, system architecture, time characteristic parameters of control-loop ere, a performance analysis model for real-time Ethemet-based CNC system was proposed, which is able to include the timing effects caused by the implementation platform in the simulation. The key for establishing the model is accomplished by designing the error analysis module and the controller nodes. Under the restraint of CPU resource and communication bandwidth, the experiment with a case study was conducted, and the results show that if the deadline miss ratio of data packets is 0.2%, then the percentage error is 1.105%. The proposed model can be used at several stages of CNC system development. 展开更多
关键词 computer numerical control (CNC) system real-time Ethemet time characteristic parameters performance analysis model manufacturing accuracy
下载PDF
Performance comparison and analysis of a combined power and cooling system based on organic Rankine cycle 被引量:2
19
作者 王志奇 周奇遇 +2 位作者 夏小霞 刘斌 张欣 《Journal of Central South University》 SCIE EI CAS CSCD 2017年第2期353-359,共7页
A novel power and cooling system combined system which coupled organic Rankine cycle(ORC) with vapor compression refrigeration cycle(VCRC) was proposed. R245 fa and butane were selected as the working fluid for the po... A novel power and cooling system combined system which coupled organic Rankine cycle(ORC) with vapor compression refrigeration cycle(VCRC) was proposed. R245 fa and butane were selected as the working fluid for the power and refrigeration cycle, respectively. A performance comparison and analysis for the combined system was presented. The results show that dual-pressure ORC-VCRC system can achieve an increase of 7.1% in thermal efficiency and 6.7% in exergy efficiency than that of basic ORC-VCRC. Intermediate pressure is a key parameter to both net power and exergy efficiency of dual-pressure ORC-VCRC system. Combined system can produce maximum net power and exergy efficiency at 0.85 MPa for intermediate pressure and 2.4 MPa for high pressure, respectively. However, superheated temperature at expander inlet has little impact on the two indicators. It can achieve higher overall COP, net power and exergy efficiency at smaller difference between condensation temperature and evaporation temperature of VCRC. 展开更多
关键词 dual-pressure organic Rankine cycle vapor compression refrigeration waste heat performance analysis
下载PDF
Performance analysis of active schedules in identical parallel machine 被引量:2
20
作者 Changjun WANG Yugeng XI 《控制理论与应用(英文版)》 EI 2007年第3期239-243,共5页
Active schedule is one of the most basic and popular concepts in production scheduling research. For identical parallel machine scheduling with jobs' dynamic arrivals, the tight performance bounds of active schedules... Active schedule is one of the most basic and popular concepts in production scheduling research. For identical parallel machine scheduling with jobs' dynamic arrivals, the tight performance bounds of active schedules under the measurement of four popular objectives are respectively given in this paper. Similar analysis method and conclusions can be generalized to static identical parallel machine and single machine scheduling problem. 展开更多
关键词 SCHEDULING Identical parallel machine Active schedule performance analysis
下载PDF
上一页 1 2 10 下一页 到第
使用帮助 返回顶部