On Proposing Statecharts to Specify Performance Models

This paper shows that Statecharts, a high-level specification technique, can be used to represent performance models. This is a powerful technique and is based on state-transition diagrams added with concepts of hierarchy and orthogonality to represent a system behavior. It is shown that Statecharts may conveniently be used to represent models with richness and clarity. Using an analytical approach the technique to determine performance measurements is provided. Three examples are presented and the results show Statecharts' potential for representing systems for performance evaluation.     

Mechanism of nucleation and growth of cubic boron nitride thin films

The mechanism and the crystallography of the nucleation and growth of cubic boron nitride (c-BN) films deposited on 100-oriented silicon substrate by RF bias sputtering have been studied by means of cross-sectional high-resolution transmission electron microscopy and X-ray photoelectron spectroscopy. Both methods provide experimental information showing no sp²-bonded BN layer formation in the subsurface region of c-BN phase. This is clear evidence for layer-by-layer homoepitaxial growth of cubic boron nitride without graphitic monolayers in the near-surface region of the film. The turbostratic boron nitride (t-BN) consists of thin sub-layers, 0.5–2 nm thick, growing in such a way that a sub-layer normal is almost parallel to the growth direction. t-BN also comprises a large volume fraction of the grain boundaries with high interface energies. The present result and the finding by Shtansky et al. [Acta Mater. 48, 3745 (2000)], who showed that an individual sub-layer consists of parallel lamellae in both the hexagonal (h-BN) and rhombohedral (r-BN) configurations, demonstrate that high intrinsic stress in the films is due to the complex structure of sp²-bonded BN. The crystallography of c-BN films indicates heteroepitaxial nucleation of cubic phase on the graphitic BN structural precursor. The present results are consistent with stress-induced c-BN formation.     

Pairing, Stripes, Lattice Distortions, and Superconductivity in Cuprate Oxides

We propose a model for a spatially modulated collective state of superconducting cuprates in which the electronic properties vary locally in space. In this model, the regions of higher hole density (called stripes) are described as Luttinger liquids and the regions of lower density (antiferromagnetic ladders) as an interacting bosonic gas of hole pairs. We show that the transition to the superconducting state is topologic and driven by decay processes among these elementary excitations in the presence of vibrations.     

Modelling the Effects of Climate Change on Water Resources in Central Sweden

This article describes investigationsinto the effects of climate change on flow regimes oftwenty-five catchments (from 6 to 1293 km²) incentral Sweden. Hydrological responses of fifteenhypothetical climate change scenarios (e.g.combinations of T = +1, +2 and +4 °C andP = 0, ± 10%, ± 20%) were simulated by a conceptual monthly water balance model. The results suggest thatall the hypothetical climate change scenarios wouldcause major decreases in winter snow accumulation.Significant increase of winter flow and decrease ofspring and summer runoff were resulted from mostscenarios. Attendant changes in actualevapotranspiration were also examined for all climatechange scenarios. Despite the changes in seasonaldistribution of evapotranspiration, the change inannual total evapotranspiration was relatively smallwith the maximum change of 23% compared with the 76%for mean annual snow water equivalent changes and 52%for mean annual runoff changes. Such hydrologicresults would have significant implications on futurewater resources design and management.     

A Gesture Based Interface for Human-Robot Interaction

Service robotics is currently a highly active research area in robotics, with enormous societal potential. Since service robots directly interact with people, finding natural and easy-to-use user interfaces is of fundamental importance. While past work has predominately focussed on issues such as navigation and manipulation, relatively few robotic systems are equipped with flexible user interfaces that permit controlling the robot by natural means. This paper describes a gesture interface for the control of a mobile robot equipped with a manipulator. The interface uses a camera to track a person and recognize gestures involving arm motion. A fast, adaptive tracking algorithm enables the robot to track and follow a person reliably through office environments with changing lighting conditions. Two alternative methods for gesture recognition are compared: a template based approach and a neural network approach. Both are combined with the Viterbi algorithm for the recognition of gestures defined through arm motion (in addition to static arm poses). Results are reported in the context of an interactive clean-up task, where a person guides the robot to specific locations that need to be cleaned and instructs the robot to pick up trash.     

单叶双曲迥转面等距曲面工件的轮廓线形状分析及绘制

运用解析几何、微分几何、投影理论，建立了“单叶双曲迥转面等距曲面”工件的轮廓线形状数学模型，为该类零件的ＣＡＤ，ＣＡＭ提供了理论上的依据．“包络面法”、“法线法”、“换面法”等三种仪器绘图方法，在工件精度要求不很高的情况下，也完全能够达到设计制造要求．     

城市住宅建设系统动态模型研究

本文根据系统动态学的理论和方法，建立了城市住宅建设系统动态模型。该模型就象一个住宅政策的“实验室”，对城市管理者制定住宅中长期发展规划具有重要的使用价值。     

摆动活齿传动内齿轮齿形综合及齿形参数分析

论述了摆动活齿齿轮共轭齿廓的综合方法，并就内齿轮齿形进行了综合．同时进一步分析了各齿形参数对齿廓形状及传动性能的影响，为选择齿形参数指出了方向     

非高斯噪声理论模型分析

分析了非高斯噪声（ＮＧＳ）理论模型研究发展过程，特别是作为ＮＧＳ理论模型的脉冲干扰造成的影响进行了分析，同时着重综述了ＮＧＳ理论模型发展现状，并给出了较详细的概率描述，对各种污染ＮＧＳ的接收信号的检测和处理给出了不同的方法，为在这种ＮＧＳ环境下信号的检测和处理提供了理论依据。     

电力系统仿真技术的发展和应用

简介电力系统仿真技术的发展和基本概念，并分别简述了模拟计算机、数字计算机和混合计算机在电力系统中的应用，以及电力系统仿真培训装置的作用