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Search Results: 1 - 10 of 6347 matches for " Pei Yingshu "
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Guo Dongsheng,Yuan Xiaoying,Xi Yuying,Wang Aiying,Pei Yingshu,

生物物理学报 , 1999,
Abstract: 利用植物毒性试验和紫外吸收光谱法, 研究了经光物理过程修饰后的多环芳烃蒽和荧蒽对陆生单子叶植物黍的暗毒性, 以及光修饰物紫外吸收光谱的变化与植物毒性之间的关系。结果表明,在光修饰96h 范围内,蒽对黍发芽率、根长、根重、芽重的影响逐渐增大,荧蒽对黍影响的变化则不明显。利用光谱法测定蒽和荧蒽光修饰液紫外光谱的结果表明,蒽和荧蒽被光修饰的方式不同,这可能与二者的毒性变化不同相关。该结果证明,多环芳烃光毒性与在光修饰中形成毒性更强的中间化合物有关。其毒性的大小可因不同多环芳烃所具有的特定光修饰方式而改变。
Discrete Time Variable Structure Control of High Speed AMB-Milling Spindle

LIU Yingshu,

控制理论与应用 , 2002,
Abstract: This paper deals with the variable structure control of high speed milling spindle supported by active magnetic bearings (AMB-spindle). The plant model consists of electromagnetic actuators, spindle dynamics and high speed cutting process. The discrete time variable structure controller (VSC) is designed to attenuate the spindle vibration caused by the cutting process and other disturbances. Simulations show that the VSC strategy is robust against external disturbances and model perturbation. In comparison with the PID controllers, the VSC also enables a satisfactory dynamic performance to be achieved in terms of variation in depth of cut.
An Optimal Content Caching Framework for Utility Maximization
Ran Bi,Yingshu Li,Xu Zheng
- , 2016, DOI: 10.1109/TST.2016.7536715
Abstract: For desirable quality of service, content providers aim at covering content requests by large network caches. Content caching has been considered as a fundamental module in network architecture. There exist few studies on the optimization of content caching. Most existing works focus on the design of content measurement, and the cached content is replaced by a new one based on the given metric. Therefore, the performance for service provision with multiple levels is decreased. This paper investigates the problem of finding optimal timer for each content. According to the given timer, the caching policies determine whether to cache a content and which existing content should be replaced, when a content miss occurs. Aiming to maximize the aggregate utility with capacity constraint, this problem is formalized as an integer optimization problem. A linear programming based approximation algorithm is proposed, and the approximation ratio is proved. Furthermore, the problem of content caching with relaxed constraints is given. A Lagrange multiplier based approximation algorithm with polynomial time complexity is proposed. Experimental results show that the proposed algorithms have better performance.
Efficient aggregation algorithms on very large compressed data warehouses
Efficient Aggregation Algorithms on Very Large Compressed Data Warehouses

Li Jianzhong,Li Yingshu,Jaideep Srivastava,
LI Jianzhong
,LI Yingshu,Jaideep Srivastava

计算机科学技术学报 , 2000,
Abstract: Multidimensional aggregation is a dominant operation on data ware-houses for on-line analytical processing (OLAP). Many efficient algorithms to compute multidimensional aggregation on relational database based data warehouseshave been developed. However, to our knowledge, there is nothing to date in theliterature about aggregation algorithms on multidimensional data warehouses thatstore datasets in multidimensional arrays rather than in tables. This paper presentsa set of multidimensional aggregation algorithms on very large and compressed mul-tidimensional data warehouses. These algorithms operate directly on compresseddatasets in multidimensional data warehouses without the need to first decompressthem. They are applicable to a variety of data compression methods. The algorithmshave differefit performance behavior as a function of dataset parameters, sizes of out-puts and main memory availability. The algorithms are described and analyzed withrespect to the I/O and CPU costs. A decision procedure to select the most efficientalgorithm, given an aggregation request, is also proposed. The analytical and ex-perimental results show that the algorithms are more efficient than the traditionalaggregation algorithms.
IoT-Based Cost Saving Offloading System for Cellular Networks
Zhuojun Duan,Mingyuan Yan,Qilong Han,Lijie Li,Yingshu Li
- , 2017, DOI: 10.23919/TST.2017.7986941
Abstract: Nowadays, with the new techniques available in hardware and software, data requests generated by applications of mobile devices have grown explosively. The large amount of data requests and their responses lead to heavy traffic in cellular networks. To alleviate the transmission workload, offloading techniques have been proposed, where a cellular network distributes some popular data items to other wireless networks, so that users can directly download these data items from the wireless network around them instead of the cellular network. In this paper, we design a Cost Saving Offloading System (CoSOS), where the Internet of Things (IoT) is used to undertake partial data traffic and save more bandwidth for the cellular network. Two types of algorithms are proposed to handle the popular data items distribution among users. The experimental results show that CoSOS is useful in saving bandwidth and decreasing the cost for cellular networks.
Why “Ding-Dong Community” Cannot Succeed Like American Version “Nextdoor”?  [PDF]
Pei Deng
Journal of Service Science and Management (JSSM) , 2015, DOI: 10.4236/jssm.2015.84065
Abstract: The conception of community O2O is very popular currently in China, which has become the focus of attention in the field of e-commerce. However, since at the preliminary exploration stage everything in this area changes very quickly, there is not yet mature business model to mimic. Many of the problems should be studied and clarified. Taking the rise and failure of “ding-dong district” as a case, this article attempts to analyze the unsuccessful reason that “ding-dong district” imitates the US version “Nextdoor” in the context of China, and put forward the corresponding countermeasures and suggestions, aiming to provide related reference for Chinese enterprises in the exploration and development of community e-commerce.
Fiber Bragg Grating Strain Sensing Detecting Multi-Crack Damages under Vibrating Status  [PDF]
Pei Luo
Optics and Photonics Journal (OPJ) , 2017, DOI: 10.4236/opj.2017.78B002
The multi-crack damages modal of simple supported beam has been build, at the vibrating status, the multi-damage detecting method of simple supported beam measured by fiber Bragg grating strain sensing array has been studied. From 0 hz to 200 hz, using exciter vibrating simple supported beam, with different damages, resonant frequency of simple supported beam has changed. So, when the damage appears in simple supported beam, the local rigidity will decrease, the resonant frequency of simple supported beam will be affected, the damage status of simple supported beam have been determined by this. The experimental result indicates that the resonant frequency of simple supported beam has changed when there is no damage, one damage, two damages, three damages on simple supported beam. According to this, the fiber Bragg grating strain sensing array can detect multi-crack damage of simple supported beam under vibrating status.
Japanese Ways of Developing Urban Underground Recreation Space  [PDF]
Pei Zhang
World Journal of Engineering and Technology (WJET) , 2018, DOI: 10.4236/wjet.2018.62030
Abstract: This paper defines the concept of urban recreation space at first, and thenfocuses on the six aspects of experience in?functional orientation, joint development, business planning, environment designing,recreational route designing, operation and management based on reviewing the development process of the underground street in urban recreation space in Japan.The results show that the overall planning and detailed design of urban recreational space in Japan is worth learning and drawing lessons for all countries in the world.
Structure Damage Identification via Fiber Grating Strain Sensing Array Detecting and Wavelet Analysis  [PDF]
Pei Luo
Optics and Photonics Journal (OPJ) , 2018, DOI: 10.4236/opj.2018.89025
Abstract: The measuring method of structure damage during vibrating has been developed by applying simple supported beam as object of study, fiber Bragg grating strain sensing array as the measuring method, and wavelet package analysis as signal extracting tools. The damage data of simple supported beam at vibrating state has been collected. The damage characteristic indexes have been extracted based on analyzing and handling the damage data with wavelet analysis. The experiment shows that fiber Bragg grating strain sensing array can sensitively measure the experimental data of simple supported beam at vibrating state. The fiber Bragg grating strain sensing array measuring is a new method in dynamic measurement.
The Influence of Residents’ Opinions on the Redesign of Urban Underground Streets: A Case Study from Diyi Underground Street  [PDF]
Pei Zhang
Journal of Building Construction and Planning Research (JBCPR) , 2018, DOI: 10.4236/jbcpr.2018.64015
Abstract: The rapid development of urbanization and rapid growth of urban population have brought about various urban problems, and the development of cities to the ground and underground has become an inevitable choice. Underground street is a kind of underground space types, and it is also an important urban recreational resources and tourism resources. The evaluation of underground street users, especially the residents and tourists, has important reference value for the recreational resources’ redevelopment of underground street. Firstly, this paper reviews the relevant research literature on underground street and Post-Occupancy Evaluation theory, then chooses Diyi Underground Street, Chengdu, China, as the research object, and conducts a questionnaire survey and in-depth interviews on residents’ shopping intention from five dimensions of underground street environment, decoration, commercial form, public facilities and other aspects. Finally, the survey data are analyzed quantitatively. The results show that some influence factors such as air quality, daylighting, decoration style etc. greatly affect the willingness of residents to enter the street. Therefore, residents’ recreational experience should be emphasized during the underground street re-planning according to the above factors.
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