基于STM8的红外与超声波测距仪设计

介绍了一种基于STM8单片机的红外和超声波相结合的距离继电器的应用设计。阐述了该距离继电器的测距原理。经实际应用证明,该距离继电器的测量距离远大于10 m,克服了普通超声波测量距离只能达到5 m左右的问题,并且消除了测量的盲区。测量精度可以精确到1 cm,符合并超过实际应用要求。     

Intervention and strategy analysis for web group-learning

Abstract Owing to the lack of face-to-face interactions, students using a web-based learning system are likely to study alone and with relatively little classmate support and pressure. Teachers in a web-based learning system may apply a group-learning model to overcome this problem. Teachers first need to organise, manage and monitor the group learning and they must take appropriate actions based on teaching strategies to improve the learning achievements of the students. To perform these tasks effectively, teachers must obtain relevant information by analysing the huge volume of web-access logs or by monitoring web interactions. This paper presents novel methodologies for developing instruments to assist teachers in performing intervention and strategy analysis. The proposed methodologies apply data mining tools provided by existing database management systems. Database techniques, including the multi-dimensional cube, are then applied to make student web logs meaningful and helpful to teachers in managing group learning. The associate rule mining tool is finally employed to assist teachers in analysing their pedagogical strategies. These tools relieve teachers of tedious data collection and analysis, allowing them to focus on managing the groups to promote students' learning achievement.     

一类轧机的板形最优化控制方法

分析了常规四辊CVC轧机板形控制的原理,结合生产实际给出了板形的最优化控制策略及其数学模型,该方法具有不需对板形缺陷进行识别,不用基于最小二乘法的曲线拟合的方法进行板形缺陷的识别的特点.对调节装置的调节量及多个调节装置的调节量采用联合求解方法,具有快速达到最佳优点,可推广到其它同类轧机的板形控制中去.     

A MODIFIED METHOD FOR SUPERVISOR SPECIFICATION AND SYNTHESIS OF A CLASS OF DISCRETE EVENT SYSTEMS

In this paper, a model‐refining method is proposed to alleviate the complexity involved in specification interpretation of DES control problems. The legal constraint language is defined in terms of illegal states and events in contrast with constructing the automaton of the specification language. This method could provide a more intuitive view of the DES control problem and would be suitable for practical implementation. Two examples, which have commonly been used in the literature, are employed to show the efficiency of the proposed method. Further, under this framework, it is shown that the supremal controllable sublanguage can take a simpler form based on the concept of an illegal state set. A state‐based supervisor synthesis procedure is presented, and a simple example is provided.     

Multi-product economic lot scheduling problem with manufacturing and remanufacturing using a basic period policy

In this research we study the multi-product Economic Lot Scheduling Problem (ELSP) with manufacturing and remanufacturing opportunities. Manufacturing and remanufacturing operations are performed on the same production line. Both manufactured and remanufactured products have the same quality thus they fulfil the same demand stream. Tang and Teunter (2006) firstly studied this type of Economic Lot Scheduling Problem with Returns (ELSPR) and presented a complex algorithm for the optimal solution. More recently Teunter, Tang, and Kaparis (2009) proposed several heuristics to deal with the same problem using more computational efficient approaches. However, both studies have limited the attention to the common cycle policy with the assumption that a single (re)manufacturing lot is used for each item in each cycle. Relaxing the constraint of common cycle time and a single (re)manufacturing lot for each item in each cycle, we propose a simple, easy to implement algorithm, based on Segerstedt (1999), to solve the model using a basic period policy. Several numerical examples show the applicability of the algorithm and the cost savings.     

ISHair: Importance Sampling for Hair Scattering

We present an importance sampling method for the bidirectional scattering distribution function (bsdf) of hair. Our method is based on the multi‐lobe hair scattering model presented by Sadeghi et al. [ [SPJT10] ]. We reduce noise by drawing samples from a distribution that approximates the bsdf well. Our algorithm is efficient and easy to implement, since the sampling process requires only the evaluation of a few analytic functions, with no significant memory overhead or need for precomputation. We tested our method in a research raytracer and a production renderer based on micropolygon rasterization. We show significant improvements for rendering direct illumination using multiple importance sampling and for rendering indirect illumination using path tracing.     

基于FSM模型检验的安全测试技术研究

安全性、可靠性是计算机软硬件系统达到用户满意度的重要指标,为了保证其安全,在系统投入使用之前必须要经过严格的安全性测试。提出一种基于FSM(Finate State Machine)和FTA(fault tree analysis)的模型检测的形式化安全性测试方法来验证被测系统的安全性。该方法具有较高的通用性,能详细地分析软件模型可能出现的故障。     

构件化仿真模型研究与自动化实现

为提高仿真系统的可扩展性、适应性、可重用性和互操作性等特性,将软件构件技术引入到仿真系统的开发中,对仿真模型构件进行深入的分析与研究,主要包括仿真构件的模型分析、仿真构件的元数据描述、仿真构件的实现结构分析。最后,设计并开发了仿真构件自动化开发工具,实现了仿真构件的代码框架自动生成与仿真构件的自动化组装。     

基于光斑室内移动机器人的定位导航技术

现代建筑室内结构日益复杂化,特别是伴随人口老龄化的加剧,家庭安全问题引起人们广泛关注。为了解决室内定位与导航的问题,提出基于光斑室内移动机器人的定位与导航技术,依靠机器人自带红外发射装置与外带摄像头相结合,实现室内情况下对机器人的精确定位与准确导航,并且可以广泛应用于扫地机器人、家庭监控机器人等家庭服务机器人,为实现机器人自动路径规划、自动充电、自动巡航、自动避障等功能提供保障。     

维吾尔语词法中音变现象的自动还原模型

该文针对维吾尔语的音变现象,提出了一种自动还原模型。与以往方法不同的是,此模型中我们把音变现象泛化,先假设维吾尔语中所有语音都有音变现象,从而将还原问题转化为类似于词性标注问题,再利用标注的方法解决了还原操作。在新疆多语种信息技术重点实验室手工标注的《维吾尔语百万词词法分析语料库》上做了实验,还原模块作为维吾尔语词法分析器的一部分,把词法分析器功能的F值从84.1%提高到了91.4%,同时维吾尔语中词缀数目最多、变形情况最复杂的动词词干的还原正确率也达到了88.6%,实际应用中完全可以被接受。