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Search Results: 1 - 10 of 94962 matches for " Peng Liu "
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Workflow Mining of More Perspectives of Workflow  [PDF]
Peng Liu, Bosheng Zhou
Journal of Software Engineering and Applications (JSEA) , 2008, DOI: 10.4236/jsea.2008.11012
Abstract: The goal of workflow mining is to obtain objective and valuable information from event logs .The research of workflow mining is of great significance for deploying new business process as well as analyzing and improving the already deployed ones. Many information systems log event data about executed tasks. Workflow mining is concerned with the derivation of a graphical process model out of this data. Currently, workflow mining research is narrowly focused on the rediscovery of control flow models. In this paper, we present workflow mining of more perspectives of workflow to broaden the scope of workflow mining. The mining model is described with GBMS’s VPML and we present the entire model’s workflow mining with the GBMS’s VPML.
Numerical Calculation of Dynamic Response for Multi-Span Non-Uniform Beam Subjected to Moving Mass with Friction  [PDF]
Junping Pu, Peng Liu
Engineering (ENG) , 2010, DOI: 10.4236/eng.2010.25048
Abstract: In order to simulate the coupling vibration of a vehicle or train moves on a multi-span continuous bridge with non-uniform cross sections, a moving mass model is used according to the Finite Element Method, the effect of the inertial force, Coriolis force and centrifugal force are considered by means of the additive matrices. For a non-uniform rectangular section beam with both linear and parabolic variable heights in a plane, the stiffness and mass matrices of the beam elements are presented. For a non-uniform box girder, Romberg numerical integral scheme is adopted, each coefficient of the stiffness matrix is obtained by means of a normal numerical computation. By applying these elements to calculate the non-uniform beam, the computational accuracy and efficiency are improved. The finite element method program is worked out and an entire dynamic response process of the beam with non-uniform cross sections subjected to a moving mass is simulated numerically, the results are compared to those previously published for some simple examples. For some complex multi-span bridges subjected to some moving vehicles with changeable velocity and friction, the computational results, which can be regarded as a reference for engineering design and scientific research, are also given simultaneously.
Absorption Enhanced Methanol Synthesis in a Trickle Bed Reactor over Cu/Zn/Al2O3 Catalyst  [PDF]
Peng Liu, Zhenmin Cheng
Journal of Materials Science and Chemical Engineering (MSCE) , 2015, DOI: 10.4236/msce.2015.36005
Abstract:

Methanol synthesis in a trickle bed reactor with tetraethylene glycol dimethyl ether (TEGDME) as the liquid phase over a Cu/Zn/Al2O3 catalyst was investigated. The pressure was kept constant at 5.0 MPa, while the temperature ranged from 230℃?to 260℃?and the mass space velocity varied between 294 L·Kg-1·h-1 and 1655 L·Kg-1·h-1. The effects of temperature and space velocity on CO conversion and methanol productivity were studied. Methanol synthesis processes in trickle bed with the TEGDME and paraffin oil as liquid phase were compared with the fixed bed process. The results indicated that the optimal temperature was approximately 240. When the space velocity was increased, the CO conversion decreased while the methanol productivity increased. The liquid introduced can help to keep the reactor nearly isothermal. For methanol synthesis in trickle-bed reactor, TEGDME was better than paraffin oil. Effect of TEGDME on the reaction was twofold. On one hand, it absorbs the methanol and speeds up the reaction. On the other hand, it also increases the mass transfer resistance and hinders the reaction.

Study on the Threshold Effect of Urbanization on Energy Consumption  [PDF]
Xiaoyu Liu, Duyun Peng
Theoretical Economics Letters (TEL) , 2018, DOI: 10.4236/tel.2018.811145
Abstract: Energy is an important material impetus for urbanization, while urbanization is also key factors that stimulate the energy consumption increase. The rapid development of China’s urbanization in recent years has led to changes in the total energy consumption and structure, which will inevitably affect the realization of China’s rapid and sustainable economic development goals. Therefore, this article was based on panel data from 2005 to 2016 of 30 provinces in China, used energy consumption as the explained variable, the urbanization rate as the core variable, GDP per capita as threshold variables, and selected GDP per capita, industrialization level, urban per capita disposable income, the density of urban population, the proportion of the tertiary industry as control variables. Meanwhile, the threshold model was used to study the threshold effect. We put focus on the nonlinear relationship between urbanization and energy consumption and the corresponding regional differences and hope to make reasonable suggestions for optimizing the industrial structure and finally realizing the coordinated development of urbanization and energy consumption in China. The results show that in the accelerated stage of economic development, the main impact of urbanization is to accelerate the increase of energy consumption. When the level of economic development enters the post-industrialization stage, the stimulation of urbanization on energy consumption becomes smaller, which means that the urbanization transformation will face great pressure on energy consumption. Therefore, this paper considered China in three areas, eastern, middle and western areas to transversely compare and analyze, and put forward three rationalization proposals: To speed up the marketization of construction, promote economic development of the western and middle region, and narrow the gap of urbanization development of areas; to coordinate urbanization development and energy consumption in the eastern and western regions, accelerate industrial restructure in the middle and western regions, and promote sound and rapid urbanization; to grasp the law of urbanization’s effect on energy consumption and control the trend of energy consumption.
Mono-dispersed Functional Polymeric Nanocapsules with Multi-lacuna via Soapless Microemulsion Polymerization with Spindle-like α-Fe2O3Nanoparticles as Templates
Liu Guangfeng,Liu Peng
Nanoscale Research Letters , 2009,
Abstract: The mono-dispersed crosslinked polymeric multi-lacuna nanocapsules (CP(St–OA) nanocapsules) about 40 nm with carboxylic groups on their inner and outer surfaces were fabricated in the present work. The small conglomerations of the oleic acid modified spindle-like α-Fe2O3nanoparticles (OA–Fe2O3) were encapsulated in the facile microemulsion polymerization with styrene (St) as monomer and divinyl benzene (DVB) as crosslinker. Then the templates, small conglomerations of OA–Fe2O3, were etched with HCl in tetrahydrofuran (THF). The surface carboxylic groups of the crosslinked polymeric multi-lacuna nanocapsules were validated by the Zeta potential analysis.
Allocating Collaborative Profit in Less-than-Truckload Carrier Alliance  [PDF]
Peng Liu, Yaohua Wu, Na Xu
Journal of Service Science and Management (JSSM) , 2010, DOI: 10.4236/jssm.2010.31018
Abstract: International Financial Crisis has made the less-than-truckload (LTL) industry face with severe challenges of survival and development. More and more small and medium-sized LTL carriers choose to collaborate as the potential savings are large, often in the range 5–15%. A key question is how to distribute profits/savings among the participants. Since every LTL carriers are guided by their own self-interests and their contributions to the collaboration are quite different, the proposed allocation method should be a collectively and individually desirable solution. In this paper, we firstly analyze the profit opportunities from collaboration and present mechanisms to realize these benefits by two illustrative examples. Based on the cooperative game theory, we formulate the LTL collaboration game and discuss the well-known profit allocation concepts including Proportional Allocation, Shapley value and Nucleolus. We then propose a new al-location method named Weighted Relative Savings Model (WRSM) which is in the core and minimizes the maximum difference between weighted relative savings among the participants. Simulation result for real-life instances shows the effectiveness of WRSM.
Experimental Investigation of Evolution Process of Nonlinear Characteristics from Chatter Free to Chatter  [PDF]
Fansen Kong, Peng Liu, Xiaoming Wang
Journal of Modern Physics (JMP) , 2011, DOI: 10.4236/jmp.2011.29126
Abstract: The vibration acceleration time history of the cutter holder was separated into three parts; namely, chatter free, transition and chatter processes. The reconstructed attractor and probability distribution of vibration acceleration time series were studied in order to observe the system’s behavior. The Lyapunov exponent andKolmogorov entropy were used to help judge the cutting state. Meanwhile, the relation curves of the Lyapunov exponent and entropy versus machining parameters were plotted and discussed. The research shows that Lyapunov exponent and Kolmogorov entropy are toned up when vibration acceleration time his- tory goes from chatter free, transition to chatter. When cutting state transited from chatter free to chatter, the Lyapunov exponent and Kolmogorov entropy increase with increasing amplitude. In addition, the relation curves looks like stability lobes. The experimental study allow us to select optimal machining parameters for decreasing the uncertainty of cutting vibration.
Comprehensive Benefit Analysis of Direct Expansion Ground Source Heat Pump System  [PDF]
Yuefen Gao, Yingxin Peng, Juanjuan Liu
Energy and Power Engineering (EPE) , 2013, DOI: 10.4236/epe.2013.52A009
Abstract:

Direct Expansion Ground Source Heat Pump (DXGSHP) system directly extracts heat or cold energy from ground by consuming electricity to provide for space conditioning. Compared with the currently widely-used secondary loop Ground Couple Heat Pump (GCHP) system, it has higher energy efficiency, lower operating costs, and less environmental impact. A case study is carried out in this paper. The subject is a residential building located in Beijing, China. It is assumed that the building adopts the DXGSHP system and the GCHP system respectively. Annual loads and energy consumption are simulated and computed. Then the initial cost, operating cost and CO2 emission are calculated. The economic benefit is analyzed with the Payback Time method and the Dynamic Annual Cost Value method. The environmental benefit is discussed mainly by comparing the CO2 emission savings. The results show that the DXGSHP system has higher initial costs, but lower operating costs, and less greenhouse gas emissions. The DXGSHP system has better comprehensive benefits than the GCHP system.

De novo cavernous aneurysms development after contralateral parent artery occlusion—Two cases report  [PDF]
Tangming Peng, Zenghui Qian, Aihua Liu
Open Journal of Clinical Diagnostics (OJCD) , 2013, DOI: 10.4236/ojcd.2013.34032
Abstract: A 53-year-old woman developed a de novo aneurysm after contralateral internal carotid artery occlusion, and another 42-year-old woman developed a de novo aneurysm after contralateral vertebral artery occlusion. Both patients experienced a rapid development of de novo aneurysm formation, 6 and 9 months, respectively. The development of de novo aneurysm on the contralateral artery after parent artery occlusion showed that female and medium age may be contributory factors. In addition, the hemodynamic changes may be associated with the development of de novo aneurysm after contralateral parent artery occlusion.
Analysis of R & D Capability of China’s Blockchain Technologies  [PDF]
Xiaoyu Liu, Duyun Peng, Youdong Wen
Theoretical Economics Letters (TEL) , 2018, DOI: 10.4236/tel.2018.810124
Abstract: As the pioneer of emerging technologies, China’s blockchain technology-led enterprises are crucial to R & D capabilities. Through the collection of relevant data from 2015 to 2017, the input and output indicators were constructed; the DEA analysis method was used to evaluate the R & D efficiency, and the EM iterative algorithm was used for cluster analysis. The 15 companies were divided into three categories. It was found that the company’s average pure technical efficiency was 0.68, and UFIDA’s R & D investment was the largest. There were eight companies with input redundancy and insufficient output. There is a high degree of correlation between R & D scale efficiency and EM clustering results. If a firm is increasing in size or constant in scale, it is often classified as Category 2 or Category 3, otherwise it is classified as Category 1.
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