水源保护区划界的遥感与GIS技术研究

科学合理地划定水源地的保护范围是一项技术含量较高的工作。以厦门市饮用水源中的北溪引水渠(管道)和坂头水库为例,根据饮用水源保护区划分原则,研究基于数字化的地形图建立数字高程模型并自动生成汇水区盆地和流域范围的GIS技术、获取相关自然环境专题信息的遥感技术、以及综合利用社会和自然等多种数据源进行保护区范围界定的方法。重点探讨数字高程模型的建立以及汇水区盆地和流域边界自动生成的GIS方法。     

组合网--第三代网络之上的一个台阶

由于当今技术的发展 ,形形色色基于数据通信的服务也相应而出。例如 ,基于多媒体的远程教育或影视节目、可视电话以及基于网络的交互式电子游戏。然而目前所有的无线网络都是针对某种特定的服务而设计及优化的 ,各个无线网络有着不同的特性。例如 ,不同的无线网支持的带宽不同 ,对应用软件提供的服务质量不同 ,对终端移动性支持的程度不同 ,以及为传输每比特所花费的代价不同。每一个无线网可有效地支持一种或几种数据服务。然而 ,没有一个无线网络可有效地支持所有基于数据通信的服务。不仅如此 ,在欧洲、美洲及亚洲即将推出的第三代无线网络也不能满足所有数据通信的要求。因此 ,如今科技发展的方向是 :将各种用于不同服务的无线网络融合成一体来支持形形色色的数据服务[1～ 3 ] 。将阐述组合网的概念 ,描述组合网的结构 ,并且提出一个基于第三代无线网络之上的组合网。     

Linking Business Processes and Information Systems Provision in a Dynamic Environment

This paper discusses decision and communication processes which link strategic activity in a business with information systems development activity. We develop a model which illustrates these processes as observed in one company (AXA Sun Life, Bristol HQ), but we suggest there may be generalizable features. We use Role Activity Diagrams as our diagramming method.In most organizations it is impractical to achieve a fully articulated business model and IS architecture. Organizations do try to make development (or acquisition) of information systems which will serve business needs as orderly as they can, in circumstances which are inherently complex and unstable. We suggest that the degree of regularity which is achieved in IS development within the business context comes not so much from following one overarching plan, as from a continuous process of adjustment, in which local short-term plans are weighed against current understanding of the business's key interests. What is needed to aid this process is a general framework of communication and decision making within which plans can be reviewed and modified in the light of changing circumstances. This paper presents an attempt to reveal and represent such a framework.     

Assessment of breed type and ageing time effects on beef meat quality using two different texture devices

Forty-two male yearlings were used to assess the influence of breed type and ageing time on beef texture. Samples of the M. longissimus dorsi of four breed types [double muscled (DM), dual purpose (Brown Swiss, BS), fast growth (FG) and unimproved type (UT)] were aged for 1, 3, 7, 10, 14 or 21 days at 4°C and frozen at −18°C until analysed. Cooked samples (to end-point of 70°C) were assessed using a Warner–Bratzler (WB) device. Raw samples were assessed using a compression device in which transverse elongation was prevented. There were no significant differences in WB values of cooked meat due to breed type, but ageing had a significant (P<0.05) on maximum load. Ageing, but not breed type, had a significant effect on the compression values of raw meat at low compression rates (P<0.001). Compression values, of raw samples, at 80% compression differed significantly (P<0.001) between breed types, but were not affected by ageing. Compression values of raw samples, at 80% compression, were affected by breed type, probably because of genotype differences in the contribution of connective tissue.     

Predicting Chemical Parameters of River Water Quality from Bioindicator Data

We address the problem of inferring chemical parameters of river water quality from biological ones. This task is important for enabling selective chemical monitoring of river water quality. We apply machine learning, in particular regression tree induction, to biological and chemical data on the water quality of Slovenian rivers. Regression trees are constructed that predict values of chemical parameters from data on the presence of bioindicator taxa at the species and family levels.     

用夹点法合成常减压蒸馏装置的换热网络

采用夹点法对某炼油厂常减压装置的换热网络进行了优化合成，与原换热网络相比，本换热网络的加热炉热负荷大约降低了１２．７％，换热面积增大了７．８％，冷公用工程均用于发生水蒸汽．     

Behaviour of chromium-coated steels in sodium polysulphide environments

Several chromium coatings on mild steels were characterized and placed in media containing sodium polysulphides for corrosion studies. Chemical corrosion was studied up to 440°C and electrochemical corrosion at 350°C. Chromium plating with subsequent high temperature treatment was found to give the best results but chromized steels were also found to be suitable for use in cells below 350°C.     

Integrating Guidance into Relational Reinforcement Learning

Reinforcement learning, and Q-learning in particular, encounter two major problems when dealing with large state spaces. First, learning the Q-function in tabular form may be infeasible because of the excessive amount of memory needed to store the table, and because the Q-function only converges after each state has been visited multiple times. Second, rewards in the state space may be so sparse that with random exploration they will only be discovered extremely slowly. The first problem is often solved by learning a generalization of the encountered examples (e.g., using a neural net or decision tree). Relational reinforcement learning (RRL) is such an approach; it makes Q-learning feasible in structural domains by incorporating a relational learner into Q-learning. The problem of sparse rewards has not been addressed for RRL. This paper presents a solution based on the use of reasonable policies to provide guidance. Different types of policies and different strategies to supply guidance through these policies are discussed and evaluated experimentally in several relational domains to show the merits of the approach.