复杂模型的快速数字化扫描

数字化扫描是最迅速地直接从给出的模型或实物中获得大量几何数据的方法。高效的计算机系统从这些几何数据中生成NC程序,用于加工和测量。

用红色印模膏取个别托盘在牙槽嵴丰满全口义齿中的临床应用

目的寻找做全口义齿制取个别托盘的更简便、更经济实用的方法。方法选择老年人牙槽嵴丰满初戴全口义齿的患者48例,年龄60~70岁,用数字表法随机分为观察组25例和对照组23例。观察组用印模膏、藻酸盐印模材和无牙合托盘取一次印模,取初模型,再用取一次印模的印模膏托盘做个别托盘取终模型,做全口义齿;对照组常规印模膏、藻酸盐印模材和无牙合托盘取一次印模,取初模型,自凝树脂做个别托盘取终模型,做全口义齿。分析两组戴牙7、14 d满意度和咀嚼效率。结果两组戴牙7 d咀嚼满意度、舒适满意度、咀嚼效率差异有统计学意义(χ2=4.510,P=0.036;χ2=4.057,P=0.044;t=2.046,P=0.046),而固位、语言、外观、坚固满意度差异无统计学意义(均P>0.05);戴牙14 d,两组各项满意度、咀嚼效率差异无统计学意义(均P>0.05)。结论印模膏与自凝树脂做全口义齿的个别托盘在满意度、咀嚼效率方面差异在戴牙早期有临床意义。牙槽嵴丰满初戴全口义齿的患者可以用印模膏代替自凝树脂做个别托盘取终印模。

Behavior Measurement Model Based on Prediction and Control of Trusted Network

In order to construct the trusted network and realize the trust of network behavior,a new multi-dimensional behavior measurement model based on prediction and control is presented.By using behavior predictive equation,individual similarity function,group similarity function,direct trust assessment function,and generalized predictive control,this model can guarantee the trust of an end user and users in its network.Compared with traditional measurement model,the model considers different characteristics of various networks.The trusted measurement policies established according to different network environments have better adaptability.By constructing trusted group,the threats to trusted group will be reduced greatly.Utilizing trusted group to restrict individuals in network can ensure the fault tolerance of trustworthiness of trusted individuals and group.The simulation shows that this scheme can support behavior measurement more efficiently than traditional ones and the model resists viruses and Trojans more efficiently than older ones.

Model predictive control synthesis algorithm based on polytopic terminal region for Hammerstein-Wiener nonlinear systems

An improved model predictive control algorithm is proposed for Hammerstein-Wiener nonlinear systems.The proposed synthesis algorithm contains two parts:offline design the polytopic invariant sets,and online solve the min-max optimization problem.The polytopic invariant set is adopted to replace the traditional ellipsoid invariant set.And the parameter-correlation nonlinear control law is designed to replace the traditional linear control law.Consequently,the terminal region is enlarged and the control effect is improved.Simulation and experiment are used to verify the validity of the wind tunnel flow field control algorithm.

A statistical end-to-end performance model for networks with complex topologies

Network calculus provides new tools for performance analysis of networks, but analyzing networks with complex topologies is a challenging research issue using statistical network calculus. A service model is proposed to characterize a service process of network with complex topologies. To obtain closed-form expression of statistical end-to-end performance bounds for a wide range of traffic source models, the traffic model and service model are expanded according to error function. Based on the proposed models, the explicit end-to-end delay bound of Fractional Brownian Motion（FBM） traffic is derived, the factors that affect the delay bound are analyzed, and a comparison between theoretical and simulation results is performed. The results illustrate that the proposed models not only fit the network behaviors well, but also facilitate the network performance analysis.

Science of empirical design in mining ground control

Many problems in rock engineering are limited by our imperfect knowledge of the material properties and failure mechanics of rock masses. Mining problems are somewhat unique, however, in that plenty of real world experience is generally available and can be turned into valuable experimental data.Every pillar that is developed, or stope that is mined, represents a full-scale test of a rock mechanics design. By harvesting these data, and then using the appropriate statistical techniques to interpret them,mining engineers have developed powerful design techniques that are widely used around the world.Successful empirical methods are readily accepted because they are simple, transparent, practical, and firmly tethered to reality. The author has been intimately associated with empirical design for his entire career, but his previous publications have described the application of individual techniques to specific problems. The focus of this paper is the process used to develop a successful empirical method. A sixstage process is described: identification of the problem, and of the end users of the final product; development of a conceptual rock mechanics model, and identification of the key parameters in that model;identification of measures for each of the key parameters, and the development of new measures(such as rating scales) where necessary; data sources and data collection; statistical analysis; and packaging of the final product. Each of these stages has its own potential rewards and pitfalls, which will be illustrated by incidents from the author's own experience. The ultimate goal of this paper is to provide a new and deeper appreciation for empirical techniques, as well as some guidelines and opportunities for future developers.

Novel IOV worm model and its corresponding hybrid anti-worm strategy in expressway interchange terminal

In order to take precaution and cure against intemet of vehicles （IOV） worm propagation in expressway, the IOV worm propagation and its corresponding anti-worm strategy were studied in expressway interchange terminal. According to omnirange driving in expressway interchange terminal and vehicular mobile communication environment, an IOV worm propagation model is constructed; and then according to the dynamic propagation law and destructiveness of IOV worm in this environment, a novel hybrid anti-worm strategy for confrontation is designed. This worm propagation model can factually simulates the IOV worm propagation in this interchange terminal environment; and this hybrid anti-worm strategy can effectively control IOV worm propagation in the environment, moreover, it can reduce the influence on network resource overhead.

Empirical Analysis on Continuous Improvement of Mobile Content Services＇ Effects on Continuance Use Intention

With the development of intelligent terminals and mobile applications,the influence of continuous improvement on mobile content services to the continuance use intention is more and more significant.Based on the expectation-confirmation theory and information system continuance use theory,this paper proposes a mobile content continuance use model and puts forward related assumptions under the mobile commerce environment by introducing the continuous improvement variables.Questionnaire data are collected from 219 mobile content service users for research,and the hypothetical model is validated by the structural equation modeling.Results show that the information system continuance use model is still valid under the mobile commerce environment,and the continuous improvement on mobile content services have positive impacts on user's expectations after they have experienced certain mobile content services.

On Deciding Sustainable Distribution Center of a Supply Chain

A supply chain is a network that performs the procurement of raw material, the transportation of raw material to intermediate and end products, and the distribution of end products to retailers or customers. Installation and operation of distribution centers and all downstream members play a vital role in fulfilling the customers demand and have a great impact for supply chain management performance. In this paper we address a new approach for solving a supply chain optimization model to decide distribution centers based on environmental consideration.

Throughput Capacity of a Container Terminal Considering the Combination Patterns of the Types of Arriving Vessels

The throughput capacity of a container terminal is very important in planning and designing at container terminals.The existing methods estimated the throughput capacity without considering its change resulting from the different combination patterns of the types of arriving vessels.A simulation model is established to estimate the throughput capacities of a container terminal under different combination patterns of the types of arriving vessels.It shows that the throughput capacity of a container terminal is influenced by the utilization rates of the berth and quay cranes which result from the different combination patterns of the types of the arriving vessels.It provides a practical approach to estimate the throughput capacity of a container terminal considering the types of the vessels,and it is also helpful for the decision makers to raise the throughputs of the container terminals by optimizing the combination patterns of the types of arriving vessels.