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81.
This article analyzes the dynamics of motion of various setups of two multiple degree‐of‐freedom (DOF) fingers that have soft tips, in fine manipulation of an object, and shows performances of their motions via computer simulation. A mathematical model of these dynamics is described as a system of nonlinear differential equations expressing motion of the overall fingers‐object system together with algebraic constraints due to tight area contacts between the finger‐tips and surfaces of the object. First, problems of (1) dynamic, stable grasping and (2) regulation of the object rotational angle by means of a setup of dual two‐DOF fingers, are treated. Second, the problem of regulating the position of the object mass center by means of a pair of two‐DOF and three‐DOF fingers is considered. Third, a set of dual three‐DOF fingers is treated, in order to let it perform a sophisticated task, which is specified by a periodic pattern of the object posture and a constant internal force. In any case, there exist sensory‐motor coordinations, which are described by analytic feedback connections from sensing to actions at finger joints. In the cases of setpoint control problems, convergences of motion to secure grasping together with the specified object rotational angle and/or the specified object mass center position, are proved theoretically. A constraint stabilization method (CSM) is used for solving numerically the differential algebraic equations to show performances of the proposed sensory‐feedback schemes. © 2002 Wiley Periodicals, Inc. 相似文献
82.
83.
Nanometre-sized silver halides entrapped in SiO2 matrices 总被引:2,自引:0,他引:2
The formation of nanocrystals after implantation of silver alone as well as together with the halogen ions Cl, Br and I into a SiO2 layer of about 100 nm was studied by X-ray diffraction and transmission electron microscopy. The co-implantation of Ag and Cl or Br results in the formation of cubic AgX crystals which are stable in size under annealing. The co-implantation of Ag and I as well as single Ag implantation result in Ag crystallites, which grow under annealing. The annealing procedure causes a redistribution of the particles within the layer. 相似文献
84.
We describe the construction of a new DNA-modified electrode based on an electroactive film. 5-Hydroxy-1,4-naphthoquinone is coelectrooxidized with 5-hydroxy-3-thioacetic acid-1,4-naphthoquinone to give a copolymer, presenting both electroactive and chemically reactive groups. The carboxylic function acts as a precursor for the covalent grafting of ODN probes while the quinone group acts as the transduction element of hybridization. Electrochemical detection was performed by differential pulse voltammetry in the electroactivity domain of the quinone group (i.e., at very low potentials, 0 to -0.8 V vs SCE). A very clear modification of the redox activity is observed between unmodified and probe-modified films and especially upon addition of target ODN. 相似文献
85.
Cuing Pham 《今日电子》2007,(5):63
Windows XP Embedded Service Pack 2 Feature Pack 2007(以下简称FP2007)推出了用于嵌入式应用的USB启动功能。现在,用户可以通过一个USB闪存驱动器(UFD)、a.k.a.、U盘和USB密钥等来启动并构建一个Windows XPe的映像。构建这种启动Windows XP Embedded的USB设备的过程中,只要直接使用Target Designer,并准备好需要启动的UFD,就像使用ufdprep.exe(FP2007中包含的一个工具)文件一样简单。 相似文献
86.
Linh Mai Jae-Young Lee Van-Su Pham Giwan Yoon 《Microwave and Wireless Components Letters, IEEE》2007,17(12):867-869
In this letter, we present the design and fabrication of a novel ZnO-based film bulk acoustic wave resonator (FBAR) microwave devices. The novel FBAR devices employ a new-type of Bragg reflector with very thin chromium (Cr) layer formed between SiO2 and W films. The Cr layer seems to enhance the adhesion between SiO2 and W layers. The novel FBAR devices show good return losses (S11) and high Q-factors at the frequency range of 2.7-3.0 GHz. This approach will be very helpful for mobile worldwide interoperability for microwave access applications. 相似文献
87.
Anh Pham The Nguyen Duc Thang La The Vinh Young-Koo Lee Sungyoung Lee 《Applied Intelligence》2013,39(2):367-385
Spectral clustering (SC) is currently one of the most popular clustering techniques because of its advantages over conventional approaches such as K-means and hierarchical clustering. However, SC requires the use of computing eigenvectors, making it time consuming. To overcome this limitation, Lin and Cohen proposed the power iteration clustering (PIC) technique (Lin and Cohen in Proceedings of the 27th International Conference on Machine Learning, pp. 655–662, 2010), which is a simple and fast version of SC. Instead of finding the eigenvectors, PIC finds only one pseudo-eigenvector, which is a linear combination of the eigenvectors in linear time. However, in certain critical situations, using only one pseudo-eigenvector is not enough for clustering because of the inter-class collision problem. In this paper, we propose a novel method based on the deflation technique to compute multiple orthogonal pseudo-eigenvectors (orthogonality is used to avoid redundancy). Our method is more accurate than PIC but has the same computational complexity. Experiments on synthetic and real datasets demonstrate the improvement of our approach. 相似文献
88.
Since the beginning of the ‘Doi Moi’ policy in 1986, Hanoi has witnessed significant changes in its urban areas. Landsat and Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) scenes were used to identify built-up areas in Hanoi, and spatial metrics were used to characterize urban change patterns from 1975 to 2003. Firstly, a spatial metric called the ‘percentage of like adjacency’ was used to discern urban growth patterns, which were classified into three sub-patterns: expansion growth, infill growth and outlying growth. Secondly, the driving force underlying the urbanization of the city for the 1975–1984, 1984–1992, 1992–2001, 2001–2003 periods was investigated using a spatial metric analysis programme (FRAGSTATS). The expansion of urban areas along major transportation routes in the latter 1980s was identified as the main form of urbanization in Hanoi. This paper shows the potential application of spatial metrics as secondary sources of information for supporting remotely sensed data and their use to characterize urban growth patterns. 相似文献
89.
General nonlinear time-varying difference systems with time-varying delay are considered. Some new explicit criteria for global exponential stability are given. Two examples are given to illustrate the obtained results. 相似文献
90.
Tien Dat Pham Kunihiko Yoshino Nga Nhu Le Dieu Tien Bui 《International journal of remote sensing》2013,34(22):7761-7788
ABSTRACTAboveground biomass (AGB) of mangrove forest plays a crucial role in global carbon cycle by reducing greenhouse gas emissions and mitigating climate change impacts. Monitoring mangrove forests biomass accurately still remains challenging compared to other forest ecosystems. We investigated the usability of machine learning techniques for the estimation of AGB of mangrove plantation at a coastal area of Hai Phong city (Vietnam). The study employed a GIS database and support vector regression (SVR) to build and verify a model of AGB, drawing upon data from a survey in 25 sampling plots and an integration of Advanced Land Observing Satellite-2 Phased Array Type L-band Synthetic Aperture Radar-2 (ALOS-2 PALSAR-2) dual-polarization horizontal transmitting and horizontal receiving (HH) and horizontal transmitting and vertical receiving (HV) and Sentinel-2A multispectral data. The performance of the model was assessed using root mean square error (RMSE), mean absolute error (MAE), coefficient of determination (R2), and leave-one-out cross-validation. Usability of the SVR model was assessed by comparing with four state-of-the-art machine learning techniques, i.e. radial basis function neural networks, multi-layer perceptron neural networks, Gaussian process, and random forest. The SVR model shows a satisfactory result (R2 = 0.596, RMSE = 0.187, MAE = 0.123) and outperforms the four machine learning models. The SVR model-estimated AGB ranged between 36.22 and 230.14 Mg ha?1 (average = 87.67 Mg ha?1). We conclude that an integration of ALOS-2 PALSAR-2 and Sentinel-2A data used with SVR model can improve the AGB accuracy estimation of mangrove plantations in tropical areas. 相似文献