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Decision-Making Method for Problem of Goal Type Based on Evaluation Criterion
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作者 蒋尚华 冯勤超 +1 位作者 江孝感 徐南荣 《Journal of Southeast University(English Edition)》 EI CAS 2002年第3期254-258,共5页
The presently existing decision making method for problem of goal type, i.e. the goal programming, is popular to some extent. In this paper we analyzed the features of the problem and the method,based on which we foun... The presently existing decision making method for problem of goal type, i.e. the goal programming, is popular to some extent. In this paper we analyzed the features of the problem and the method,based on which we found some defects of the method and pointed out these defects. To overcome these defects we absorbed the spirit and exploited concepts of evaluation criterion and the fault measure of evaluation criterion. We proposed and applied a method with an evaluation criterion, after which we also p... 展开更多
关键词 multi objective decision making evaluation criterion fault measure of evaluation criterion pre optimized objective set
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Multi Objective Decision Making Method Based on Evaluation Criterion for Problems with Linear Value Function
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作者 蒋尚华 韩勇 徐南荣 《Journal of Southeast University(English Edition)》 EI CAS 1998年第1期114-121,共8页
A class of interactive multi objective decision making method by means of evaluation criterion is proposed for problems with linear value function,in which case,the decision maker(DM) usually has only unwhole infor... A class of interactive multi objective decision making method by means of evaluation criterion is proposed for problems with linear value function,in which case,the decision maker(DM) usually has only unwhole information of weights for objectives. The concept of fault measure of the evaluation criterion is proposed to measure the deviation of the evaluation criterion from the DMs preference structure.The approach to obtain an upper boundary of fault measure of an evaluation criterion,and the approach to modify the evaluation criterion to be one with smaller fault measure,and the approach to obtain a pre optimized objective set by evaluation criterion with certain fault measure are also proposed. 展开更多
关键词 multi objective decision making evaluation criterion fault measure of evaluation criterion pre optimized objective set
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Numerical simulation of drop weight impact sensitivity evaluation criteria for pressed PBXs 被引量:1
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作者 Hong-zheng Duan Yan-qing Wu +1 位作者 Kun Yang Feng-lei Huang 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2023年第1期76-90,共15页
A thorough understanding of drop-weight impacted responses for polymer-bonded explosives(PBXs)is significant to evaluate their impact sensitivity.The characteristics of the drop-weight impacted pressed PBXs including ... A thorough understanding of drop-weight impacted responses for polymer-bonded explosives(PBXs)is significant to evaluate their impact sensitivity.The characteristics of the drop-weight impacted pressed PBXs including deforming,fracturing,forming a local high-temperature region and igniting,were simulated using a coupled mechanical-thermo-chemical model integrating micro-defects evolution.A novel evaluation method for impact sensitivity is established using the relation between the input kinetic energy and the output energy due to deformation,crushing energy,local hot spot energy and ignition.The effects of impact velocity on sensitivity were analyzed and the critical local ignition impact velocity is determined as 4.0-4.5 m/s.The simulated results show that shear-crack friction heating is the dominant ignition mechanism.The region along the boundary of PBXs sample is the most hazardous regions where ignition first occur.The propagation of stress wave in PBXs causes shear-crack hotspot and bulk temperature exhibiting an approximate 45°direction evolution path,which is the main reason that dominated damage-ignition region transits from the boundary to the central of sample. 展开更多
关键词 Polymer-bonded explosives(PBXs) Drop weight impact Numerical simulation Sensitivity evaluation criterion Hotspot mechanism
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Influence of inaccurate wavelet phase estimation on seismic inversion 被引量:18
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作者 Yuan San-Yi Wang Shang-Xu 《Applied Geophysics》 SCIE CSCD 2011年第1期48-59,95,共13页
On the assumption that the seismic wavelet amplitude spectrum is estimated accurately, a group of wavelets with different phase spectra, regarded as estimated wavelets, are used to implement linear least-squares inver... On the assumption that the seismic wavelet amplitude spectrum is estimated accurately, a group of wavelets with different phase spectra, regarded as estimated wavelets, are used to implement linear least-squares inversion. During inversion, except for the wavelet phase, all other factors affecting inversion results are not taken into account. The inversion results of a sparse reflectivity model (or blocky impedance model) show that: (1) although the synthetic data using inversion results matches well with the original seismic data, the inverted reflectivity and acoustic impedance are different from that of the real model. (2) the inversion result reliability is dependent on the estimated wavelet Z transform root distribution. When the estimated wavelet Z transform roots only differ from that of the real wavelet near the unit circle, the inverted reflectivity and impedance are usually consistent with the real model; (3) although the synthetic data matches well with the original data and the Cauchy norm (or modified Cauchy norm) with a constant damping parameter has been optimized, the inverted results are still greatly different from the real model. Finally, we suggest using the L1 norm, Kurtosis, variation, Cauchy norm with adaptive damping parameter or/and modified Cauchy norm with adaptive damping parameter as evaluation criteria to reduce the bad influence of inaccurate wavelet phase estimation and obtain good results in theory. 展开更多
关键词 PHASE seismic wavelet INVERSION evaluation criterion ROOT
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Maximum Entropy Distribution Function and Uncertainty Evaluation Criteria 被引量:5
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作者 CHEN Bai-yu KOU Yi +3 位作者 ZHAO Daniel WU Fang WANG Li-ping LIU Gui-lin 《China Ocean Engineering》 SCIE EI CSCD 2021年第2期238-249,共12页
Marine environmental design parameter extrapolation has important applications in marine engineering and coastal disaster prevention.The distribution models used for environmental design parameter usually pass the hyp... Marine environmental design parameter extrapolation has important applications in marine engineering and coastal disaster prevention.The distribution models used for environmental design parameter usually pass the hypothesis tests in statistical analysis,but the calculation results of different distribution models often vary largely.In this paper,based on the information entropy,the overall uncertainty test criteria were studied for commonly used distributions including Gumbel,Weibull,and Pearson-III distribution.An improved method for parameter estimation of the maximum entropy distribution model is proposed on the basis of moment estimation.The study in this paper shows that the number of sample data and the degree of dispersion are proportional to the information entropy,and the overall uncertainty of the maximum entropy distribution model is minimal compared with other models. 展开更多
关键词 maximum entropy distribution model UNCERTAINTY information entropy evaluation criterion
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Geological characteristics,evaluation criteria and discovery significance of Paleogene Yingxiongling shale oil in Qaidam Basin,NW China 被引量:3
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作者 LI Guoxin ZHU Rukai +7 位作者 ZHANG Yongshu CHEN Yan CUI Jingwei JIANG Yinghai WU Kunyu SHENG Jun XIAN Chenggang LIU He 《Petroleum Exploration and Development》 CSCD 2022年第1期21-36,共16页
Major breakthroughs of shale oil exploration have been made recently in the upper member of Paleogene Lower Ganchaigou Formation of Yingxiongling area, Qaidam Basin. However, the low total organic carbon content of sa... Major breakthroughs of shale oil exploration have been made recently in the upper member of Paleogene Lower Ganchaigou Formation of Yingxiongling area, Qaidam Basin. However, the low total organic carbon content of saline-lacustrine source rock, and unclear genetic mechanism, evaluation criteria and resources potential of the shale oil have restricted the exploration and evaluation of Yingxiongling shale oil. Through analysis of large amounts of cores, well drilling, seismic, laboratory test data and integrated study, focusing on the shale and mixed types of shale oil reservoirs characterized by high-frequency interbedded organic-rich laminated shale and limy dolomite, it is concluded that the shale oil in the upper member of Lower Ganchaigou Formation in the Yingxiongling area have six geological characteristics:(1) two-stage hydrocarbon generation of hydrogen-rich source rock and large amount of retained oil;(2) multiple types of reservoir space and good reservoir properties;(3)source-reservoir integration, thick “sweet spot” and high oil-bearing grade;(4) high pressure coefficient between and under salt layers, and sufficient formation energy;(5) high content of light components, high gas-oil ratio, and good quality of the crude oil;(6) high content of brittle minerals and good fracability. The evaluation criterion of shale oil is preliminarily established based on the eight parameters: total organic carbon content, maturity, effective porosity, oil saturation, brittle mineral content,pressure coefficient, lamellation density, and burial depth. Combined with parameters of E32 source rock thickness, area, vertical distribution of oil layers, and free hydrocarbon content, the shale oil resources have been preliminarily estimated as 21×10^(8) t.The structurally stable area is the predominant objective of shale oil exploration and the favorable exploration area for Yingxiongling shale oil is nearly 800 km^(2). 展开更多
关键词 Yingxiongling shale oil Qaidam Basin Paleogene Lower Ganchaigou Formation mixed sedimentation hydrogen-rich source rocks evaluation criterion
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Systematic Method of Applying Structural Characteristics of Natural Organisms to Mechanical Structures 被引量:1
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作者 行登海 陈五一 《Transactions of Tianjin University》 EI CAS 2011年第4期293-297,共5页
Structural bionic design lacks mature and scientific theories, and the excellent structural characteristics of natural organisms sometimes cannot be transferred into engineering structures effectively. Aiming at overc... Structural bionic design lacks mature and scientific theories, and the excellent structural characteristics of natural organisms sometimes cannot be transferred into engineering structures effectively. Aiming at overcoming the existing problems, this paper summarizes three related theories: similarity theory, fuzzy evaluation theory and optimization theory. Based on the related theories, a method of structural bionic design is introduced, which includes four steps: selecting the most useful structural characteristic of natural organism; analyzing the structural characteristic finally chosen for engineering problem; completing the structural bionic design for engineering structure; and verifying the structural bionic design. Similarity theory and fuzzy evaluation theory are employed to achieve Step 1. In Step 2 and Step 3, optimization theory is employed to analyze the parameters of structures. Together with the thoughts of simplification and grouping, optimization theory can reveal the relationship between organism structure and engineering structure, providing a way to structural bionic design. A general evaluation criterion is proposed in Step 4, which is feasible to evaluate the performance of different structures. Finally, based on the method, a structural bionic design of thin-walled cylindrical shell is introduced. 展开更多
关键词 structural bionic design similarity theory fuzzy evaluation OPTIMIZATION evaluation criterion
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Investigation on the Changing Characteristics of Flow-Induced Noise in a Centrifugal Pump 被引量:1
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作者 Guanpeng Li Lihui Sun +4 位作者 Zhaoyang Wang Chunguo An Chang Guo Shen Cheng Ming Gao 《Fluid Dynamics & Materials Processing》 EI 2021年第5期989-1001,共13页
Centrifugal pumps are widely used in engineering for a variety of applications.A known drawback of these devices is the high-level noise generated during operations,which can affect their stability and adversely influ... Centrifugal pumps are widely used in engineering for a variety of applications.A known drawback of these devices is the high-level noise generated during operations,which can affect their stability and adversely influence the entire working environment.By combining the Powell vortex sound theory,numerical simulations and experimental measurements,this research explores the trends of variation and the corresponding underlying mechanisms for the flow-induced noise at various locations and under different operating conditions.It is shown that the total sound source intensity(TSSI)and total sound pressure level(TSPL)in the impeller,in the region between the inlet to the outlet and along the circumferential extension of the volute,are much higher than those at pump inlet and outlet.Additionally,under various rotational speeds with the design flow rate(Condition 1),the TSSI and TSPL at pump inlet and outlet are higher than those obtained with the opening of the valve kept unchanged(Condition 2);vice versa when these two parameters are evaluated at various locations in the impeller and the volute under the Condition 2,they exceed the equivalent values obtained for the other Condition 1. 展开更多
关键词 Flow-induced noise centrifugal pump noise evaluation criterion Powell vortex sound theory numerical simulations
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Sweet spot evaluation and exploration practice of lacustrine shale oil of the second member of Kongdian Formation in Cangdong sag, Bohai Bay Basin 被引量:1
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作者 HAN Wenzhong ZHAO Xianzheng +6 位作者 JIN Fengming PU Xiugang CHEN Shiyue MU Liangang ZHANG Wei SHI Zhannan WANG Hu 《Petroleum Exploration and Development》 CSCD 2021年第4期900-910,共11页
Based on core,thin section,X-ray diffraction,rock pyrolysis,CT scanning,nuclear magnetic resonance and oil testing data,the macro and micro components,sedimentary structure characteristics,of Paleogene Kong 2 Member i... Based on core,thin section,X-ray diffraction,rock pyrolysis,CT scanning,nuclear magnetic resonance and oil testing data,the macro and micro components,sedimentary structure characteristics,of Paleogene Kong 2 Member in Cangdong sag of Huanghua depression and evaluation standard and method of shale oil reservoir were studied to sort out the best shale sections for shale oil horizontal wells.According to the dominant rock type,rhythmic structure and logging curve characteristics,four types of shale lithofacies were identified,namely,thin-layered dolomitic shale,lamellar mixed shale,lamellar felsic shale,and bedded dolomitic shale,and the Kong 21 sub-member was divided into four quasi-sequences,PS1 to PS4.The PS1 shale has a porosity higher than 6%,clay content of less than 20%,and S1 of less than 4 mg/g;the PS2 shale has well-developed laminar structure,larger pore and throat size,better connectivity of pores and throats,high contents of TOC and movable hydrocarbon,S1 of over 4 mg/g,clay content of less than 20%,and porosity of more than 4%;PS3 shale has S1 value higher than 6 mg/g and clay content of 20%-30%,and porosity of less than 4%;and PS4 shale has lower TOC content and low oil content.Shale oil reservoir classification criterion based on five parameters,free hydrocarbon content S1,shale rhythmic structure,clay content,TOC and porosity,was established.The evaluation method of shale oil sweet spot by using the weighted five parameters,and the evaluation index EI were proposed.Through comprehensive analysis,it is concluded that PS2 is best in quality and thus the dual geological and engineering sweet spot of shale oil,PS3 and PS1 come next,the former is more geologic sweet spot,the latter more engineering sweet spot,and PS4 is the poorest.Several vertical and horizontal wells drilled in the PS2 and PS3 sweet spots obtained high oil production.Among them,Well 1701 H has produced stably for 623 days,with cumulative production of over 10000 tons,showing bright exploration prospects of Kong 2 Member shale oil. 展开更多
关键词 shale lithofacies rhythmic structure weighted quantitative evaluation shale oil sweet spot shale oil evaluation criterion Cangdong sag Bohai Bay Basin PALEOGENE Kong 2 Member
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A New Evaluation Criterion for Optimizing the Mechanical Properties of Toughened Polypropylene/Silica Nanocomposites 被引量:2
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作者 Hossein Pourrahmani Mona Golparvar Mohammad Fasihi 《Chinese Journal of Polymer Science》 SCIE CAS CSCD 2020年第8期877-887,I0008,共12页
This study aims to experiment with the mechanical properties of polypropylene(PP)/thermoplastic elastomer/nano-silica/compatibilizer nanocomposite using the melt mixing method.The addition of polyolefin elastomers has... This study aims to experiment with the mechanical properties of polypropylene(PP)/thermoplastic elastomer/nano-silica/compatibilizer nanocomposite using the melt mixing method.The addition of polyolefin elastomers has proved to be an approachable solution for low impact strength of PP,while it would also reduce the Young's modulus and tensile strength.That is why reinforcement would be applied to this combination to enhance the elastic modulus.The mechanical properties of the prepared composites were devised to train an artificial neural network to predict these properties of the system in 6256 unknown points.Therefore,the sensitivity analysis was performed and the share of each input parameter on the respective output values was calculated.Additionally,a novel parameter called nanocomposite evaluation criterion(NEC)is introduced to analyze the suitability of the nanocomposites considering the mechanical properties.Accordingly,the formulation with optimal mechanical properties of toughness,elongation at break,tensile strength,Young's modulus,and impact strength was obtained. 展开更多
关键词 NANOCOMPOSITE Polypropylene(PP) SILICA Artificial neural networks Nanocomposite evaluation criterion(NEC) Sensitivity analysis
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Evaluation of criterion validity of CHF-quality of life scale of integrative medicine
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作者 万洁 《China Medical Abstracts(Internal Medicine)》 2017年第1期5-,共1页
Objective To evaluate the criterion validity of Chronic Heart Failure(CHF)-Quality of Life(QOL)Scale of Integrative Medicine(abbreviated as Scale).Methods Clinical data of 249 CHF in-patients were collected.
关键词 CHF Evaluation of criterion validity of CHF-quality of life scale of integrative medicine LVEF
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Reciprocity evaluation based adaptive CCM reconstruction in FDD multi-antenna systems
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作者 Fangyuan Liao Yuhan Ruan +3 位作者 Hangyu Zhang Rui Zhang Tao Li Yongzhao Li 《Journal of Information and Intelligence》 2023年第2期148-155,共8页
In view of the difficulty of obtaining downlink channel state information,partial reciprocity based channel covariance matrix(CCM)reconstruction has attracted a lot of attention in frequency division duplex(FDD)multi-... In view of the difficulty of obtaining downlink channel state information,partial reciprocity based channel covariance matrix(CCM)reconstruction has attracted a lot of attention in frequency division duplex(FDD)multi-antenna systems.Taking both the impact of CCM reconstruction on system performance and design complexity,we investigate an adaptive CCM reconstruction in this paper.Specifically,to effectively evaluate the validity of the reciprocity,we firstly analyze the characteristics of the partial reciprocity and define a reciprocity evaluation criterion.Then,we propose a partial antenna based angular power spectrum(APS)estimating algorithm to further reduce the complexity of the CCM reconstruction.Finally,simulation results demonstrate the superiority of our proposed schemes. 展开更多
关键词 Frequency division duplex Partial reciprocity Channel covariance matrix reconstruction Reciprocity evaluation criterion Angular power spectrum
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Underwater acoustic communication and the general performance evaluation criteria 被引量:12
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作者 Jian-guo HUANG Han WANG +2 位作者 Cheng-bing HE Qun-fei ZHANG Lian-you JING 《Frontiers of Information Technology & Electronic Engineering》 SCIE EI CSCD 2018年第8期951-971,共21页
Driven by the huge demand to explore oceans, underwater wireless communications have been rapidly developed in the past few decades. Due to the complex physical characteristics of water, acoustic wave is the only medi... Driven by the huge demand to explore oceans, underwater wireless communications have been rapidly developed in the past few decades. Due to the complex physical characteristics of water, acoustic wave is the only media available for underwater wireless communication at any distance. As a result, underwater acoustic communication(UAC) is the major research field in underwater wireless communication. In this paper, characteristics of underwater acoustic channels are first introduced and compared with terrestrial communication to demonstrate the difficulties in UAC research. To give a general impression of the UAC, current important research areas are mentioned. Furthermore, different principal modulation-based schemes for short-and medium-range communications with high data rates are investigated and summarized. To evaluate the performance of UAC systems in general,three criteria are presented based on the research publications and our years of experience in high-rate short-to medium-range communications. These three criteria provide useful tools to generally guide the design and evaluate the performance of underwater acoustic communication systems. 展开更多
关键词 Underwater acoustic communication Underwater acoustic channels High data rate Communication range Bandwidth efficiency General evaluation criterion
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Criteria for determining illegality and the theory of anti-value acts (Handlungsunwert): with a discussion of the standpoint of contemporary Chinese criminal jurisprudence 被引量:1
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作者 Zhou Guangquan 《Social Sciences in China》 2009年第3期25-40,共16页
The doctrine of illegality serves as a touchstone of criminal law theory, and research into the criteria for determining illegality is of great significance for promoting debate between different schools of thought an... The doctrine of illegality serves as a touchstone of criminal law theory, and research into the criteria for determining illegality is of great significance for promoting debate between different schools of thought and for the overall development of Chinese criminal jurisprudence. The theories of anti-value consequences (Erfolgsunwert) and anti-value acts (Handlungsunwert) take different approaches to thinking about the issue of illegality, leading to differences in the scope of establishing what constitutes a crime, the process of determining whether a crime has been committed, the relationship between crime and punishment and the correlation between criminal law and society. The (dualistic) theory of anti-value acts takes into full consideration the social reality and normative anticipations of a given period and gives due weight to the function of criminal law in guiding behavior; it is therefore a rational theory. According to this view of illegality, the act is the core issue determining illegality; infringement of legal interests is simply an element determining the "nature of the act." Criminal law does not exist only to provide restitution for injury, but also aims to cultivate citizens' consciousness of norms to prevent possible future injury. Contemporary criminal jurisprudence in China should be constructed on the basis of the (dualistic) theory of anti-value acts with a view to responding to the needs of society and promoting normative identification on the part of the general public. 展开更多
关键词 doctrine of illegality evaluation criterion infringement of legal interests violation of norms standpoint of criminal law
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Risk analysis methods of the water resources system under uncertainty 被引量:1
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作者 Zeying GUI Chenglong ZHANG +1 位作者 Mo LI Ping GUO 《Frontiers of Agricultural Science and Engineering》 2015年第3期205-215,共11页
The main characteristic of the water resources system(WRS)is its great complexity and uncertainty,which makes it highly desirable to carry out a risk analysis of the WRS.The natural environmental,social economic condi... The main characteristic of the water resources system(WRS)is its great complexity and uncertainty,which makes it highly desirable to carry out a risk analysis of the WRS.The natural environmental,social economic conditions as well as limitations of human cognitive ability are possible sources of the uncertainties that need to be taken into account in the risk analysis process.In this paper the inherent stochastic uncertainty and cognitive subjective uncertainty of the WRS are discussed first,from both objective and subjective perspectives.Then the quantitative characterization methods of risk analysis are introduced,including three criteria(reliability,resiliency and vulnerability)and five basic optimization models(the expected risk value model,conditional value at risk model,chance-constrained risk model,minimizing probability of risk events model,and the multi-objective optimization model).Finally,this paper focuses on the various methods of risk analysis under uncertainty,which are summarized as random,fuzzy and mixed methods.A more comprehensive risk analysis methodology for the WRS is proposed based on the comparison of the advantages,disadvantages and applicable conditions of these three methods.This paper provides a decision support of risk analysis for researchers,policy makers and stakeholders of the WRS. 展开更多
关键词 water resources system evaluation criterion optimization model risk analysis method UNCERTAINTY
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A Survey on Performance Optimization of High-Level Synthesis Tools
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作者 Lan Huang Da-Lin Li +2 位作者 Kang-Ping Wang Teng Gao Adriano Tavares 《Journal of Computer Science & Technology》 SCIE EI CSCD 2020年第3期697-720,共24页
Field-programmable gate arrays(FPGAs)have recently evolved as a valuable component of the heterogeneous computing.The register transfer level(RTL)design flows demand the designers to be experienced in hardware,resulti... Field-programmable gate arrays(FPGAs)have recently evolved as a valuable component of the heterogeneous computing.The register transfer level(RTL)design flows demand the designers to be experienced in hardware,resulting in a possible failure of time-to-market.High-level synthesis(HLS)permits designers to work at a higher level of abstraction through synthesizing high-level language programs to RTL descriptions.This provides a promising approach to solve these problems.However,the performance of HLS tools still has limitations.For example,designers remain exposed to various aspects of hardware design,development cycles are still time consuming,and the quality of results(QoR)of HLS tools is far behind that of RTL flows.In this paper,we survey the literature published since 2014 focusing on the performance optimization of HLS tools.Compared with previous work,we extend the scope of the performance of HLS tools,and present a set of three-level evaluation criteria,covering from ease of use of the HLS tools to promotion on specific metrics of QoR.We also propose performance evaluation equations for describing the relation between the performance optimization and the QoR.We find that it needs more efforts on the ease of use for efficient HLS tools.We suggest that it is better to draw an analogy between the HLS development process and the embedded system design process,and to provide more elastic HLS methodology which integrates FPGAs virtual machines. 展开更多
关键词 evaluation criterion field-programmable gate array(FPGA) high-level synthesis(HLS) performance optimization quality of results(QoR)
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Axially Oriented Structured Porous Layers for Heat Transfer Enhancement in a Solar Receiver Tube
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作者 DAS Shefali VERMA Neha +1 位作者 PATHAK Manabendra BHATTACHARYYA Suvanjan 《Journal of Thermal Science》 SCIE EI CAS CSCD 2021年第5期1643-1657,共15页
The present work reports a numerical investigation of heat transfer and pressure drop characteristics in a solar receiver tube with different shaped porous media for laminar and low Reynolds number turbulent flow regi... The present work reports a numerical investigation of heat transfer and pressure drop characteristics in a solar receiver tube with different shaped porous media for laminar and low Reynolds number turbulent flow regimes.Numerical simulations have been performed with finite volume-based code ANSYS(v-2017)for different shapes of porous layers axially oriented in the tube.The plain-shaped porous medium fitted up to 50%of the tube shows better performance than other-shaped porous layers.Simulations have also been performed for axially oriented structured porous media with different sizes.Axially oriented structured porous medium develops a lateral flow disturbance enhancing the intermixing of the liquid and porous medium at their interface.Structured porous medium with a 3-crest configuration shows the best heat transfer performance among all the shapes of porous media.It offers a maximum of 148%heat transfer enhancement compared to a half-filled plain porous layer,whereas it reports a maximum of 564%enhancement compared to the flow without a porous layer.The lateral flow tendency or the swirling effect helps better heat transfer performance in the axially oriented structured porous media.Performance evaluation criterion(PEC)in all types of porous media is more in the transitional flow regime than in the laminar and turbulent flow regimes.For the same operating conditions,the maximum value of the PEC in the present work is 120%higher than the maximum value of PEC for other-shaped porous media reported in the literature.Correlations for Nusselt number have been developed for both laminar and turbulent flow regimes for three crests shaped porous medium. 展开更多
关键词 porous medium structured porous layer heat transfer enhancement pressure drop performance evaluation criterion
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