Architectural Control of Hierarchical Nanobelt Superstructures in Catanionic Reverse Micelles

BaXO₄ (X = Mo, W) nanobelts and a variety of hierarchical superstructures assembled from the nanobelts have been synthesized in a catanionic reverse‐micelle system. The effects of various factors, such as the mixing ratio (r) between the anionic and cationic surfactants, the temperature, and the presence of polymeric additives, on the formation of the nanobelts and their hierarchical assembly have been examined in detail. In particular, r has been shown to be powerful in modulating the formation and assembly of the BaMoO₄ and BaWO₄ nanobelts. Architectural control of the penniform nanobelt superstructures has been readily achieved by changing the experimental parameters. A plausible two‐stage growth mechanism has been proposed for the formation of penniform BaXO₄ nanobelt superstructures in catanionic reverse micelles.     

Delamination Analysis for Laminated Composites. II: Numerical Verification

A validation of the delamination analysis models developed in a companion paper is provided through comparisons of predictions with finite‐element and elasticity solutions. The models are applied to the analysis of composite compression specimens reinforced with end tabs. An elasticity solution for the gage section of the specimens is developed. A comparison of the characteristic roots shows that the predictions of the models include the material and geometric parameters that control the behavior, and the roots corresponding to the basic stretching and bending modes are accurately predicted. The stress distribution at the interface between tabs and specimen is in good agreement with a finite‐element simulation. The interlaminar shear and peel stresses show an exponential increase with a maximum intensity at the free edges of the tabs. The behavior of previously tested specimens is explained; and practical guidelines for specimen design are provided to avoid unwanted extraneous modes of failure. The influence of the deformation modes associated with each model is investigated. An assessment of the accuracy and level of complexity is presented.     

Modelling spatio-temporal environmental data

A conceptual model for environmental data is presented with special emphasis on the ability to store spatio-temporal references of the data. Other aspects of the model are the ability to handle hierarchical data and semantics of the measurements. The model was tested with an implementation on an object-relational database management system. As a part of the test implementation, a forestry data set covering 75 years and 4900 hectares was loaded onto the database.     

计算机控制的SEESR实验系统的研制

SEESR(Simultaneous Electrochemical ESR)是研究电极过程中的自由基中间体行为的理想和方便的手段。在以前研制的ESR仪数据系统的基础上,我们应用IBM-PC/XT微机与JES-FE1XG型(JEOL产)ESR谱仪及HDV-7型恒电位仪研制了一套由计算机控制的SEESR实验装置。该系统可以完成包括循环伏安法、电流阶跃、电位阶跃及电位反转等多种电化学方法的SEESR实验。系统还具有包括数据平滑、曲线拟合等功能的多种数据处理软件,使用方便。我们应用模型化合物对该系统进行了实际测量,所得结果与文献报道一致。     

An efficient hierarchicaltraversal algorithm for ray tracing

Ray tracing has been shown to be an excellent technique for rendering realistic images. However, it is important to reduce the lengthy computation time resulting from the brute-force nature of the original ray-tracing algorithms. In this paper, two ideas are proposed to speep up the well-known hierarchical subdivision method. First, a new hierarchy traversal scheme is described to reduce the number of raybounding volume intersection tests for secondary rays. Then, a plane-sweep method is proposed to make fewer intersection checks for eye rays. Experiments and discussions are presented to prove the feasibility of our methods.     

储层识别模式的研究

用数学方法建立气测井油气储层识别模式,以解决录井中实时软件在判别依据少的条件下,及时识别油气显示假异常的难题。该判别式经实用,正到率达90％。     

Application of a Three-dimensional Wind Driven Circulation Model to Assess the Locations of New Drinking Water Intakes in Lake Ontario

A 3D transport model is used to perform a comparative analysis of several potential drinking water intakes located along the northwest shore of Lake Ontario between Toronto and Oshawa. The model is specifically used to assess each intake under both long- and short-term transport of a potential pollutant release from the Pickering Nuclear Generating Station and potential and actual pollutant releases from local land sources respectively. A model based on a 500 m grid resolution is calibrated using data collected in the aftermath of the 1992 tritium spill at the Pickering Nuclear Generation Station and subsequently used to simulate long-term transport. A model based on a 100 m grid resolution is verified using drogue studies and used to simulate short-term transport events. Both models are used to assess pollutant levels at each of nine potential intake locations under different wind scenarios and pollutant releases. Field data for the study included water quality and flow measurements from local sewers and rivers, and estimates of pollutant levels from the local waste water treatment plants. This paper describes the model setup for both the long-term and short-term transport models, calibration using field data, long-term transport modeling, short-term transport modeling, and the comprehensive analysis approach used to evaluate the nine potential intake locations proposed. Results indicated that four intakes in particular outperformed other intake locations by maintaining bottom pollutant levels within governmental standards and warning times that exceeded 20 hours.     

Model checker aided design of a controller for a wafer scanner

For a case-study of a wafer scanner from the semiconductor industry it is shown how model checking techniques can be used to compute (1) a simple yet optimal deadlock avoidance policy, and (2) an infinite schedule that optimizes throughput. in the absence of errors. Deadlock avoidance is studied based on a simple finite state model using Smv, and for throughput analysis a more detailed timed automaton model has been constructed and analyzed using the Uppaal tool. The Smv and Uppaal models are formally related through the notion of a stuttering bisimulation. The results were obtained within 2 weeks, which confirms once more that model checking techniques may help to improve the design process of realistic, industrial systems. Methodologically, the case study is interesting since two models were used to obtain results that could not have been obtained using only a single model. Supported by the European Community Project IST-2001-35304 (Ametist), http://ametist.cs.utwente.nl/.     

The formal-CAFE methodology and model checking patterns in the specification of e-commerce systems

Electronic commerce is an important application that has evolved significantly recently. However, electronic commerce systems are complex and difficult to be correctly designed. Guaranteeing the correctness of an e-commerce system is not an easy task due to the great amount of scenarios where errors occur, many of them very subtle. In this work we presents a methodology that uses formal-method techniques, specifically symbolic model checking, to design electronic commerce applications and to automatically verify them. Also, a model checking pattern hierarchy has been developed—it specifies patterns to construct and verify the formal model of e-commerce systems. We consider this research the first step to the development of a framework, which will integrate the methodology, an e-commerce specification language based on business rules, and a model checker. Adriano Pereira received the B.S. and M.S. degrees in computer science in 2000 and 2002, respectively, and he is currently pursuing the Ph.D. degree in computer science from the Federal University of Minas Gerais, Belo Horizonte, Brazil. His current interests are on performance analysis and modeling of e-business and distributed systems, and formal methods. Mark Song received the B.S., M.S. and Ph.D. degrees in computer science from the Federal University of Minas Gerais, Belo Horizonte, Brazil. His current interests are on distributed systems and formal methods – especially BMC (Bounded Model Checking). Gustavo Franco received the B.S. and M.S. degrees in computer science in 2001 and 2004, respectively, from the Federal University of Minas Gerais, Belo Horizonte, Brazil. His research was on modeling the user behavior of e-business and distributed systems, and formal methods. Actually his current interests are on software engeneering and project management of IT projects.     

Adaptive predictive control algorithm based on Laguerre Functional Model

Laguerre Functional Model has many advantages such as good approximation capability for the variances of system time‐delay, order and other structural parameters, low computational complexity, and the facility of online parameter identification, etc., so this model is suitable for complex industrial process control. A series of successful applications have been gained in linear and non‐linear predictive control fields by the control algorithm based on Laguerre Functional Model, however, former researchers have not systemically brought forward the theoretical analyses of the stability, robustness, and steady‐state performance of this algorithm, which are the keys to guarantee the feasibility of the control algorithm fundamentally. Aimed at this problem, we introduce the principles of the Incremental Mode Linear Laguerre Predictive Control (IMLLPC) algorithm, and then systemically propose the theoretical analyses and proofs of the stability and robustness of the algorithm, in addition, we also put forward the steady‐state performance analysis. At last, the control performances of this algorithm on two different physical industrial plants are presented in detail, and a number of experimental results validate the feasibility and superiority of IMLLPC algorithm. Copyright © 2005 John Wiley & Sons, Ltd.