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Search Results: 1 - 10 of 28685 matches for " Ding Han "
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Equivalence relation and partial ordering of parallel mechanisms with applications to mechanism synthesis and mobility analysis
YuanQing Wu,Han Ding
Chinese Science Bulletin , 2010, DOI: 10.1007/s11434-009-3683-5
Abstract: Motion type (or motion pattern) of a mechanism is defined as the set of all rigid motions achievable by the mechanisms’s end-effector; the motion type of a parallel mechanism equals the intersection set of all subchain motion types. The motion type of a non-instantaneous parallel mechanism locally agrees with a regular submanifold (or a Lie subgroup in particular) of the special Euclidean group SE(3). Based on submanifold germs of SE(3), we can define an equivalence relation and a partial order relation for both motion types and parallel mechanisms: two motion types are equivalent if and only if they agree on an open neighborhood around the identity element of SE(3); two motion types are comparable if and only if one is a submanifold of the other on an open neighborhood around the identity of SE(3). It is also possible to define equivalence relation and partial ordering on the collection of parallel mechanisms. In this paper, we first study properties of the equivalence and partial order relation of both motion types and parallel mechanisms, then we discuss their application in type synthesis, mobility analysis and non-overconstrained ness realization of parallel mechanisms.
Research on the Brand Diffusion of the China Mobile Communication Industry Based on the Innovation Diffusion Theory
Shihai Ding,Zhijun Han
International Journal of Business and Management , 2009, DOI: 10.5539/ijbm.v4n2p36
Abstract: Perhaps one of the fastest growing markets in China is the mobile telecom market. The brand diffusion of China Mobile Communication Industry that has not been addressed is of great importance to the practicing brand managers. In this article, the authors forecast the potential mobile phone users of China Mobile Communication Industry with the Bass model and analyze the impact of competition on the brand diffusion of China Mobile and that of China Unicom. The study yields the good prediction and the managerial implications.
On the Asymptotics of Quantum Group Spinfoam Model
You Ding,Muxin Han
Physics , 2011,
Abstract: Recently a quantum group deformation of EPRL spinfoam model was proposed in arXiv:1012.4216 by one of the authors, and in arXiv:1012.4784 by Fairbairn and Meusburger. It is interesting to study the high spin asymptotics of the quantum group spinfoam model, to see if it gives the discrete Einstein gravity with cosmological constant as its semiclassical limit. In this article we propose a new technique, which can simplify the analysis of the high spin asymptotics for quantum group spinfoam vertex amplitude. This technique can generalize the spinfoam asymptotic analysis developed by Barrett, et al to quantum group spinfoam. As a preparation of asymptotic analysis, we define and analyze the coherent states and coherent intertwiners for quantum group, which has certain "factorization properties". We show that in the high spin limit of quantum group spinfoam, many q-deformed noncommutative ingredients become classical and commutative. In particular, the squared norm of coherent intertwiner and the (Euclidean) vertex amplitude become integrals on classical group, while there are some additional terms (written in terms of classical group variables) make quantum group corrections to the usual (classical group) coherent intertwiner and vertex amplitude. These quantum group correction terms turn out to be proportional to the deformation parameter, which hopefully gives the cosmological term as its semiclassical limit.
On time-domain methods for milling stability analysis
Han Ding,Ye Ding,LiMin Zhu
Chinese Science Bulletin , 2012, DOI: 10.1007/s11434-012-5499-y
Abstract: As a basic and advanced machining technique, the high-speed milling process plays an important role in realizing the goal of high performance manufacturing. From the viewpoint of machining dynamics, obtaining chatter-free machining parameters is a prerequisite to guaranteeing machining accuracy and improving machining efficiency. This paper gives an overview on recent progress in time domain semi-analytical methods for chatter stability analysis of milling processes. The state of art methods of milling stability prediction in milling processes and their applications are introduced in detail. The bottlenecks involved are analyzed, and potential solutions are discussed. Finally, a brief prospect on future works is presented.
Gravitation model for spatial network based on the heterogeneous node
Jiang-Hai Qian,Ding-Ding Han
Physics , 2008,
Abstract: In this paper we consider nodes in network are heterogeneous and the link between nodes is caused by the potential dynamical demand of the nodes. Such demand can be measured by gravitation which increases with the heterogeneous strength of node and decreases with the geographical distance. Based on this, we propose a new model for spatial network from the view of gravitation. The model is to maximize the potential dynamical demand of the whole network, indicating the possible maximal efficiency of the network and the highest profits that operators may gain. The model can vary its topology by changing two parameters. A simulation for the Chinese city airline network is completed. In the end of this article we discuss the significance and advantage of the heterogeneous nodes.
Developing Situations of Tea Plucking Machine  [PDF]
Yu Han, Hongru Xiao, Guangming Qin, Zhiyu Song, Wenqin Ding, Song Mei
Engineering (ENG) , 2014, DOI: 10.4236/eng.2014.66031

To acquire the developing trend and ways of mechanization of tea plucking, with analyzing the developing backgrounds and situations of tea plucking machine both at home and abroad, this paper obtains the conclusion that there are several countries that have conducted a lot of studies on tea plucking machine, such as Japan, England, France, India, Australia and Argentina. Among others, Japan goes ahead, where lots of researches have been conducted in the highest developing level. The article also analyses the reason why China has a poor mechanization of tea plucking and points out existing problems. Finally, some advices and measures for developing Chinese domestic mechanization of tea plucking are given.

Effect of feeding ratios on the structure and electrochemical performance of graphite oxide/polypyrrole nanocomposites
YongQin Han,Bing Ding,XiaoGang Zhang
Chinese Science Bulletin , 2011, DOI: 10.1007/s11434-011-4646-1
Abstract: Graphite oxide (GO)/polypyrrole (PPy) nanocomposites (GPYs) were synthesized using in situ polymerization. The effect of the feeding ratios of pyrrole and GO on the structure and electrochemical performances of GPYs was investigated. The structure was characterized via Fourier-transform infrared spectroscopy, scanning electron microscopy, transmission electron microscopy and X-ray diffraction. The electrochemical performance was characterized via cyclic voltammetry, galvanostatic charge-discharge and electrochemical impedance spectroscopy. The results indicate that the more pyrrole is added to GO (with GO concentrations of 20% and 50%), the more agglomeration of both PPy and GO layers occurs. This is detrimental to the capacitance utilization of PPy. When the feeding ratio of GO:pyrrole is 80:20, PPys with nanofibrils are dispersed homogenously in/on the exfoliated layer of GO and the conductivity is enhanced. The capacitance utilization of PPy in a composite with a GO concentration of 80% (383 F/g) is higher than that of pure PPy (201 F/g), which indicates the presence of a synergistic effect between GO and PPy.
Graphene-based hybrid materials and their applications in energy storage and conversion
Ding Zhou,Yi Cui,BaoHang Han
Chinese Science Bulletin , 2012, DOI: 10.1007/s11434-012-5314-9
Abstract: Graphene attracts more and more scientists and researchers owing to its superior electronic, thermal, and mechanical properties. For material scientists, graphene is a kind of versatile building blocks, and considerable progress has been made in recent years. Graphene-based hybrid materials have been prepared by incorporating inorganic species and/or cross-linking of organic species through covalent and/or noncovalent interactions. The graphene-based hybrid materials show improved or excellent performance in various fields. In this review, we summarize the synthesis of graphene and graphene-based hybrid materials, and their applications in energy storage and conversion.
Run by Run Control of Time-pressure Dispensing for Electronics Encapsulation
Cong-Ping Chen,Han Ding,

国际自动化与计算杂志 , 2008,
Abstract: To alleviate the influence of gas compressibility on the process performance of time-pressure dispensing for electronics encapsulation, a predictive model is developed based on power-law fluid to estimate the encapsulant amount dispensed. Based on the simple and effective model, a run by run (RbR) supervisory control scheme is delivered to compensate the variation resulting from gas volume change in the syringe. Both simulation and experiment have shown that the dispensing consistency has been greatly improved with the model-based RbR control strategy developed in this paper.
A CPW-FED UWB Antenna with Wimax/WLAN Band-Notched Characteristics
Han Chen;Yang Ding;De Shui Cai
PIER Letters , 2011, DOI: 10.2528/PIERL11062707
Abstract: A CPW-fed UWB antenna with WiMAX and WLAN band-notched characteristics is presented in this paper. The proposed antenna is fed by a CPW structure and provides the band-notched characteristics by etching an arc slot on the monopole plate and integrating the antenna with electromagnetically coupled microstrip resonator into a single module. In order to prevent interference problem due to existing nearby communication systems within the UWB operating frequency, the two band-notches are designed to reject possible interference with the existing 3.25-3.75 GHz band for IEEES02.16 WiMAX and 5.15-5.825 GHz band for IEEES02.11a WLAN and HIPERLAN/2 WLAN The two notched bands can easily be controlled by a few geometry parameters of the arc slot and the microstrip resonator. Surface current distributions and conceptual equivalent-circuit models are used to analyze the effect of the slot and the resonator. The proposed antenna is simulated and fabricated. Moreover, the performances of the antenna are demonstrated along with simulated and measured results.
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