检索结果-南通市图书馆

A simulation Research Towards Better Leverage of Sales Ranking

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Journal of Systems Science and Systems Engineering 2021年第1期30卷 105-122页

作者： Lin Tang Leilei Sun Chonghui Guo Yuqian Zuo Zhen Zhang Institute of Systems Engineering Dalian University of TechnologyDalian116024China SKLSDE and BDBC Lab Beihang UniversityBeijing100090China

As a kind of the most significantly popular information in markets,the sales ranking has great impacts on consumer choice.However,there are few discussions on how sales ranking should be provided to consumers in the literature.This paper aims to answer the following two questions:1)To what extent does the sales ranking influence consumer choices;2)When the sales ranking should be provided to consumers.To do so,this paper first constructs a sales ranking model and then provides detailed simulation experiments to demonstrate the model.The experimental results show that for markets where consumer preferences are dramatically different,such as music and movie markets,sales rankings do not have significant influences on consumer choices and should not be provided to consumers until a large number of early independent consumer choices have been accumulated.But for markets in which consumer preferences are similar,such as markets for official supplies,sales rankings have more influences on consumer choices and should be provided to consumers earlier.Furthermore,an evolution strategy is proposed to ascertain the most suitable sales rankings(characterised by suitable influence strength and suitable release time)for some specified online markets.The comparison results show that the optimized sales rankings not only can help consumers discover higher-quality products but also can improve overall sales.

关键词： Marketing sales ranking popularity information simulation experiments

Physical-property cutoffs of tight reservoirs by field and laboratory experiments: a case study from Chang 6, 8–9 in Ordos Basin

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Frontiers of Earth Science 2021年第2期15卷 471-489页

作者： Bingbing SHI Xiangchun CHANG Zhongquan LIU Ye LIU Tianchen GE Pengfei ZHANG Yongrui WANG Yue WANG Lixin MAO College of Earth Science and Engineering Shandong University of Science and TechnologyQingdao 266590China Laboratory for Marine Mineral Resources Pilot National Laboratory for Marine Science and TechnologyQingdao 266071China Petroleum Exploration and Development Research Institute Shengli Oilfield Company of SINOPECDongying 257015China Jiangsu Design Institute of Geology for Mineral Resources Xuzhou 221006China

Tight sandstone reservoirs are generally characterized by complex reservoir quality,non-Darcy flow,and strong heterogeneity.Approaches utilized for evaluating physical property cutoffs of conventional reservoirs maybe inapplicable.Thus,a comprehensive investigation on physical property cutoffs of tight sandstone reservoirs is crucial for the reserve evaluation and successful exploration.In this study,a set of evaluation approaches take advantage of field operations(i.e.,core drilling,oil testing,and wireline well logging data),and simulation experiments(i.e.,high-pressure mercury injection-capillary pressure(MICP)experiment,oil-water relative permeability experiment,nuclear magnetic resonance(NMR)experiment,and biaxial pressure simulation experiment)were comparatively optimized to determine the physical property cutoffs of effective reservoirs in the Upper Triassic Chang 6,Chang 8 and Chang 9 oil layers of the Zhenjing Block.The results show that the porosity cutoffs of the Chang 6,Chang 8,and Chang 9 oil layers are 7.9%,6.4%,and 8.6%,and the corresponding permeability are 0.08 mD,0.05 mD,and 0.09 mD,respectively.Coupled with wireline well logging,mud logging,and oil testing,the cut-off of the thickness of single-layer effective reservoirs are approximately 3.0 m,3.0 m,and 2.0 m,respectively.Depending on the cutoffs of critical properties,a superimposed map showing the planar distribution of the prospective targets can be mapped,which may delineate the effective boundary of prospective targets for petroleum exploration of tight sandstone reservoirs.

关键词： tight sandstone reservoirs cutoffs of petrophysical property field operations simulation experiments Yanchang Formation Ordos Basin

A novel compound biped locomotion algorithm for humanoid robots to realize biped walking

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

控制理论与应用（英文版） 2009年第1期7卷 23-28页

作者： Ruiwu XIN Nanfeng XIAO School of Computer Science and Engineering South China University of Technology Guangzhou Guangdong 510640 China

In this paper, a compound biped locomotion algorithm for a humanoid robot under development is presented. This paper is organized in two main parts. In the first part, it mainly focuses on the structural design for the humanoid. In the second part, the compound biped locomotion algorithm is presented based on the reference motion and reference Zero Moment Point （ZMP）. This novel algorithm includes calculation of the upper body motion and trajectory of the Center of Gravity （COG） of the robot. First, disturbances from the environment are eliminated by the compensational movement of the upper body; then based on the error between a reference ZMP and the real ZMP as well as the relation between ZMP and CoG, the CoG error is calculated, thus leading to the CoG trajectory. Then, the motion of the robot converges to its reference motion, generating stable biped walking. Because the calculation of upper body motion and trajectory of CoG both depend on the reference motion, they can work in parallel, thus providing double insurances against the robot＇s collapse. Finally, the algorithm is validated by different kinds of simulation experiments.

关键词： Humanoid robot Structural design Compound biped locomotion algorithm simulation experiments

Non-Exchangeable Error Compensation for Strapdown Inertial Navigation System in High Dynamic Environment

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Computers, Materials & Continua 2020年第8期64卷 973-986页

作者： Qi Wang Changsong Yang Shao’en Wu School of Computer and Software Nanjing University of Information Science and TechnologyNanjing210044China Jiangsu Engineering Center of Network Monitoring Nanjing University of Information Science and TechnologyNanjing210044China School of Automation Nanjing University of Information Science and TechnologyNanjing210044China Department of Computer Science Ball State UniversityMuncie47306USA

Strapdown non-exchangeable error compensation technology in high dynamic environment is one of the key technologies of strapdown inertial navigation system.Mathematical platform is used in strapdown inertial navigation system instead of physical platform in traditional platform inertial navigation system,which improves reliability and reduces cost and volume of system.The maximum error source of attitude matrix solution is the non-exchangeable error of rotation due to the non-exchangeable of finite rotation of rigid bodies.The rotation non-exchangeable error reaches the maximum in coning motion,although it can be reduced by shortening the correction period and increasing the real-time calculation.The equivalent rotation vector method is used to modify the attitude to reduce the coning error in this paper.simulation experiments show that the equivalent rotation vector method can effectively suppress the non-exchangeable error and improve the accuracy of attitude calculation.

关键词： Strapdown error compensation coning motion equivalent rotation vector simulation experiments

Experimental Investigation on Hydrothermal Reduction of Sulfates to H<sub>2</sub>S and Organic Sulfides by Ethene

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Open Journal of Yangtze Oil and Gas 2020年第4期5卷 188-199页

作者： Chao Han Kangle Ding Yan Liu Fujia Guan Mei Zou Zhenzhen Yu Yi Wu Key Laboratory of Exploration Technologies for Oil and Gas Resources Ministry of Education Yangtze University Wuhan Campus Wuhan China Shandong Provincial Key Laboratory of Depositional Mineralization & Sedimentary Mineral Shandong University of Science and Technology Qingdao China College of Chemistry and Environmental Engineering Yangtze University Jingzhou China College of Resources and Environment Yangtze University Wuhan Campus Wuhan China College of Petroleum Engineering Yangtze University Wuhan Campus Wuhan China

The kinetic characteristics of alkenes involved in thermochemical sulfate reduction (TSR) have been never reported in geological literature. In this study, TSR by ethene under hydrothermal conditions was performed in the constrained simulation experiments. Typical TSR products consisted of H2S, CO2, mercaptans, sulfides, thiophenes derivatives and benzothiophene. The apparent activation energy E and apparent frequency factor A for TSR by ethene were determined as 76.370 kJ/mol and 4.579 s-1, respectively. The lower activation energy for ethene involved in TSR relative to ethane suggested that the reactivity of ethene is much higher than that of ethane, in accordance with the thermodynamic analysis. Rate constants were determined experimentally using first-order kinetics extrapolate to MgSO4 half-lives of 67.329 years - 3.053 years in deep burial diagenetic settings (120°C - 180°C). These values demonstrate that the reaction rate for TSR by ethene is extraordinarily fast in high-temperature gas reservoirs (120°C - 180°C). Consequently, the newly formed ethene from thermal cracking and TSR alteration of natural gas and/or petroleum could not survive after TSR process and were rarely detected in natural TSR reservoirs.

关键词： Thermochemical Sulfate Reduction (TSR) Ethene simulation experiments Thermodynamic Analysis First-Order Kinetics

Experimental studies on pathway patterns of secondary oil migration

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Experimental studies on pathway patterns of secondary oil mi...