Automatic revision of rules used to guide the generalisation process in systems based on a trial and error strategy

Automating the generalisation process, a major issue for national mapping agencies, is extremely complex. Several works have proposed to deal with this complexity using a trial and error strategy. The performance of systems based on such a strategy is directly dependent on the quality of the control knowledge (i.e. heuristics) used to guide the trials. Unfortunately, most of the time, the definition and updation of knowledge is a fastidious task. In this context, automatic knowledge revision can not only improve the performance of the generalisation, but also allow it to automatically adapt to various usages and evolve when new elements are introduced. In this article, an offline knowledge revision approach is proposed, based on a logging of the system and on the analysis of outcoming logs. This approach is dedicated to the revision of control knowledge expressed by production rules. We have implemented and tested this approach for the automated generalisation of groups of buildings within a generalisation model called AGENT, from initial data that reference a scale of approximately 1:15,000 compared with the target map's scale of 1:50,000. The results show that our approach improves the quality of the control knowledge and thus the performance of the system. Moreover, the approach proposed is generic and can be applied to other systems based on a trial and error strategy, dedicated to generalisation or not.     

EN LANDBRUGSGEOGRAFISK ANALYSE AF GADBJERG OG GIVSKUD SOGNE

Jensen, Kr. M. and Jensen R. Helkiær: En landbrugsgeografisk analyse af Gadbjerg og Givskud sogne. Geografisk Tidsskrift 76: 34—51. København juni 1. 1977.

The agricultural development in two parishes in a former heath region in Central Jylland has been investigated. The expansion of farmland up to the turn of the century was especially in Givskud replaced by a regression period with afforestation of marginal areas. The farmers are now increasing the size of their holdings and the specialization on few crops involves a more uniform land-use.     

矿产勘查理论与实践是辩证唯物主义认识论的继承和发展

运用辩证唯物主义认识论原理,分析研究多年来的矿产勘查实践,结合国内外现阶段矿产勘查理论研究现状和未来发展趋势,认为矿产勘查理论与实践是对辩证唯物主义认识论的科学继承和发展。     

沂水县矿产资源开发利用现状及发展策略

矿产资源的开发对沂水区域经济拉动作用明显,矿业经济已成为支柱产业之一。但存在资源保障能力、开发利用水平及产品结构调整等问题,影响“十二五”期间该产业持续健康发展。因此必须制定有效对应措施,提高资源综合利用率,变资源优势为产业优势。     

A discussion on improving typhoon observation through radar by scanning the negative elevation angle

Certain feasibilities and features were discussed in typhoon detection by radar with a negative elevation angle according to the relationship between the remote detecting range and the elevation angle of the new generation weather radar, in order to rectify the disadvantages of detecting capability for remote low-level echo with a lowest elevation angle of 0.5° in the common detecting mode. The data obtained from detecting the typhoon of Haitang and Changmi with radar for their negative elevation angles and the observed data for the common lowest elevation angle of 0.5° were compared to each other. The results showed that the detection of remote low level cloud system with radar could be improved by using the negative elevation angle, and the structure and the evolution trend of a typhoon could be better judged. The increasing degree of detection for negative elevation angles in the current volume scanning mode should be helpful for predicting the intensity and developing trend of windstorms, to further improve the capability of warning and nowcasting. The detection of negative elevation angle could also help reveal the development and change of typhoon＇s low level cloud system. As far as the typhoons of Haitang and Changmi were concerned, the detecting area of Changmi was increased by 1.09 times with the negative elevation angle of 0.31°, compared with the elevation angle of 0.48° if the threshold value for the sea echo within 100 km was eliminated. Several volume scans of Haitang were increased by 2.1%-7.9% for the negative elevation angle of 0.36° compared with the elevation angle of 0.49° . Therefore, the radar detecting capability of typhoons could be improved by the detection of negative elevation angles to some extent. This could make up for the disadvantages of a low detecting capability for remote low-level echo in the common detecting mode. At the same time, a negative elevation angle could be easily influenced by the ground clutter and the close sea wave clutter which interfered with the asses     

利津县节约集约用地实践与思考

当前在国家稳增长、调结构、扩内需的背景下,深挖潜力,节约集约用地已成为土地利用工作的当务之急。利津县通过严格按照产业政策供地、加强农村集体建设用地流转、实施城乡建设用地挂钩项目等措施,提高了用地效率,促进了节约集约用地。但工作中应就土地节约集约利用水平不高、用地空间组织形式相对落后等问题,严格用地管理,优化用地模式,强化土地集约利用。     

厦门市城市内涝成因研究与对策分析

以2013年的台风＂西马仑＂带来的大范围暴雨过程导致厦门市出现严重的内涝为例,研究了暴雨、降水强度、土壤含水量、潮水顶托、地面硬化、排水管网的质量及淤积等综合因素对厦门内涝的影响,并提出厦门市城市内涝综合防御治理对策。     

中国企业"走出去"存在的问题及原因

近年来,中国不少企业已经走出国门,实施"走出去"的战略.但是从目前来看,还存在不少问题.主要表现在没有实现预期的目标、也没有给国家带来直接或间接的利益.出现这些问题的原因是中国企业竞争力还不强、投资犯有盲动的错误、违背经济规律.照目前的情形来看,中国的企业还不适宜大规模走出去.     

南岳客源市场调查与区域促销策略

南岳位于衡阳市境内，为全国五大名山之一，国家级风景名胜区。但南岳旅游市场的开拓极不理想，为了充分了解南岳客源市场的现状和存在问题，必须运用典型抽样调查法，准确分析南岳旅游客人的旅游消费行为，进而为旅游业今后的发展提供市场依据。在对南岳客源市场进行为期一年的抽样调查的基础上，从客源的结构、游客的基本特征和游客活动类型3个方面对1091份有效表格进行了系统分类整理和分析，认为南岳客源市场至少存在4个方面的问题，即旅游产品单一，文化内涵挖掘不够；接待能力不足；宣传促销力度不大；接待服务质量一般，并在此基础上对南岳客源市场提出了有针对性的重点促销区域和市场促销策略。包括：大力发展有地方情调的动态旅游；加大宣传营销力度；提高旅游从业人员素质；开发富有文化特色的旅游产品；大力营造宗教文化氛围。     

烟台市临港工业发展的战略研究

对烟台市500余家大中型企业进行问卷调查，按照临港工业标准对其中的临港工业进行统计分析，总结出烟台市临港工业发展的现状特点。同时结合烟台市发展临港工业与港口、城市和周边地区的关系，提出了烟台市发展临港工业应实施的产业发展和空间发展战略。即形成“一个突破，两个发展、三个壮大”的主导产业体系和“一条生态旅游带、五个产业组团、六大工业基地”的空间布局框架；最后围绕实现临港工业发展战略提出了配套措施。