基于MATLAB的直流调速数字控制系统的分析和设计

直流调速系统的数字化控制已得到广泛应用。文中简单介绍了直流调速系统数字控制的特点和直流调速系统模型的建立,重点介绍了数字PI控制器和利用Z域根轨迹的设计方法,以及用MATLAB进行了设计过程的仿真和稳定性、动态特性的分析。     

粮食加工厂集散控制系统的设计与实现

集散控制系统是将各自独立的智能仪表,数据采样控制单元用于现场数据采集控制,并能通过现场总线与上位计算机相连,形成的分布式控制系统（DCS）。该系统集计算机技术、控制技术、通信技术、图形显示技术于一体,采用分散控制技术、极大地提高了系统的可靠性、灵活性;采用总线技术集中管理,大大提高了系统的管理功能,并克服了PLC运算能力与存储能力有限及计算机集中式控制可靠性低等缺陷,     

农村集体经营性建设用地出让和作价入股的 交易成本控制研究 ——基于上海市的案例证据

研究目的：对比农村集体经营性建设用地出让和作价入股两种供地方式的交易成本控制措施,提出控制交易成本、优化管理政策的建议,为完善农村集体经营性建设用地管理政策提供参考。研究方法：案例分析法、比较分析法。研究结果：（1）探索构建了“供应（交易）→制度环境→交易属性→交易成本→供应（交易）”闭环式的农村集体经营性建设用地交易成本控制理论分析框架。（2）农村集体经营性建设用地出让制度相对完善,交易成本控制效果好于作价入股;在缺乏规范制度安排情况下,政府背书或担保、建立利益联结体等非正式制度安排一定程度上可以降低交易成本。（3）缺乏交易平台、交易程序和规则不完善、交易合同不规范、基准地价与价格评估不完善、监管程序缺乏等是影响交易成本控制的重要制度因素。研究结论：应当加快农村集体经营性建设用地市场交易平台建设、完善交易程序和规则、规范交易合同文本、完善用地管理政策体系等,以降低交易不确定性,有效控制交易成本。     

FWK—300安全稳定控制装置在河源站的典型应用

南京南瑞集团公司稳定技术分公司FWK—300是一种分布式、模块化、拼装式结构的通用性很强的稳定控制装置,能适应电网暂态稳定控制、频率稳定与电压稳定控制、系统主变或线路过负荷控制。FWK是升级后的安全稳定控制装置。2005年广东粤东电网安稳控制系统进行了改造工程,220KV河源站作为粤东电网北通道的一个执行站,安装了该装置。本文对该装置在河源站的典型应用作了介绍。     

FWK-300安全稳定控制装置在河源站的典型应用

南京南瑞集团公司稳定技术分公司FWK-300是一种分布式、模块化、拼装式结构的通用性很强的稳定控制装置，能适应电网暂态稳定控制、频率稳定与电压稳定控制、系统主变或线路过负荷控制。FWK-是升级后的安全稳定控制装置。2005年广东粤东电网安稳控制系统进行了改造工程，220KV河源站作为粤东电网北通道的一个执行站，安装了该装置。本文对该装置在河源站的典型应用作了介绍。     

完善企业内部财务控制体系

由于契约的不完备性、代理和信息不对称问题的存在,导致财务控制的需要。财务控制系统的设计及其运行都会导致企业资源的消耗,这就是财务控制成本。财务控制成本包括设计成本、运行成本以及经营管理者的机会成本等有关内容。     

面向治理转型的国土空间用途管制制度完善路径探讨

研究目的：明确国土空间用途管制的转型逻辑,探究国土空间用途管制制度完善路径。研究方法：文献梳理法与综合分析法。研究结果：（1）国土空间用途管制属于在地化的空间管制创新模式,是在新的价值理念与治理需求引导下的空间治理转型实践。（2）国土空间用途管制的治理目标是实现国土空间系统性、激励性与高效能管制,其治理逻辑是将国土空间用途管制小闭环嵌入到国土空间治理大闭环之中,实现自然资源部内部治理“小协同”与以自然资源部为核心的多部门治理“大协同”联动。（3）可从构建全域全要素全过程的国土空间用途管制体系、优化系统治理的“三条控制线”划定及管制规则、规范与创新国土空间用途管理政策体系、建立健全多部门权力协同机制以及利益调节机制等方面探索国土空间用途管制完善路径。研究结论：国土空间用途管制涉及多学科交叉、需要理论联系实践,将来研究要加强理论综合支撑顶层设计、关注区域差异鼓励地方创新以及尊重主体利益提高管制效能。     

完善小型单位内部会计控制

2001年6月，财政部颁布《内部会计控制规范——基本规范（试行）》和《内部会计控制规范——货币资金（试行）》，2002年12月又颁布了《内部会计控制规范——采购与付款（试行）》，《内部会计控制规范——销售与收款（试行）》等多个规范，并规定：各单位应建立适合本单位业务特点和管理要求的内部会计控制制度，并组织实施。2007年3月，企业内部控制标准委员会发布《企业内部控制规范——基本规范》及17项具体规范的征求意见稿。     

农金速览

四川农信“双11”支付宝交易额突破千万元 截至11月12日0点，“双11”购物狂欢节宣告结束，总成交额350．19亿元。通过全国农村信用社（农商行）支付宝卡通及快捷支付完成的“双11”网上购物交易总量达6051．10万元，其中四川农信创造出1007．01万元的交易额，占全国农村信用社（农商行）交易额的16．64％，在有交易数据的13家农信社（农商行）中排名第一，是全国唯一一家交易额破千万的农信社。     

基于SWOT视角的SS股份内部控制探析

本文对内部控制在现代企业管理中发挥出的重要作用进行简要阐述,基于SWOT视角详细分析SS股份有限公司的内部控制制度设计,探讨当代家族企业在建设内部控制系统时面临的难题,就内部控制存在缺陷而可能导致的企业风险提出相关建议,为内部控制的设计和更新提供相应措施,期望能为家族企业的可持续发展提供参考。     

Is spatial planning a collaborative learning process? A case study from a rural–urban gradient in Sweden

International and national policies stress the importance of spatial planning for the long-term sustainability of regions. This paper identifies the extent to which the spatial planning in a Swedish region can be characterised as a collaborative learning process. By combining qualitative interviews and systems thinking methods we analysed the main attributes of public-led spatial (i.e. comprehensive) planning in nine municipalities representing a steep urban–rural gradient in the Bergslagen region of Central Sweden. We show that the attributes of strategic spatial planning needed for collaborative learning were absent or undeveloped. All studied municipalities experienced challenges in coordinating complex issues regarding long-term planning to steer territorial development and help to solve conflicts among competing interests. Stakeholder participation was identified as a basic condition for social learning in planning. Together with stakeholders we identified the causal structure behind stakeholder participation in municipal planning processes, including main drivers and feedback loops. We conclude that there is a need for arenas allowing and promoting stakeholder activity, participation and inclusion that combines both bottom-up and top-down approaches, and where evidence-based collaborative learning can occur.     

流量可调燃气发生器压力闭环模糊控制算法

为了改进流量可调燃气发生器的调节精度,引入燃气发生器压力闭环控制,针对流量可调燃气发生器压力闭环控制特点,在压力闭环中引入了模糊积分控制,此控制算法响应速度快,超调量较小,不同工况及长时间工作下系统仍然有较好的动态特性。      

Price transmission between products at different stages of manufacturing in forest industries

The theory of demand and supply implies a positive relationship, or “price transmission” between the prices of products at different stages of manufacturing. This relationship was investigated with quarterly prices of softwood stumpage in the US South, and national prices of forest products, from 1977 to 2002. All prices, net of inflation, were found to be nonstationary and there was no evidence of co-integration between prices. Vector autogressive models, augmented by Granger causality tests and multiplier analysis showed that there was a one-to-one permanent positive response of the southern sawtimber stumpage price to a permanent change in the national lumber price. There was also a one-third permanent positive response of the national paper price to a permanent change in the national pulp price. There was no relation between regional pulpwood prices and national pulp or paper prices. When price transmission was significant, the full adjustment took about 2 years.     

The Effect of the Structural Adjustment Program on the Output,Prices and Exports of Major Agricultural Export Crops in Nigeria

The primary objective of this paper is to examine changes in the level of output, prices and exports of major export crops resulting from the Structural Adjustment Program (SAP) in Nigeria. THere two main sources of data: the Central Bank of Nigeria (CBN) through its annual reports, Economic and Financial Review, and the Nigerian Federal Office of Statistics (FOS) through its Trade Summaries. Although the SAP led to appreciable increases in output and producer prices, its effects on exports were insignificant. The implications of these for the implementation of the program are explored.     

Application of an ecosystem function framework to perceptions of community woodlands

Owners, local residents, government, and conservation organisations can express divergent preferences in the development and management of local woodlands. The perceptions of these four groups were examined, in the context of three community woodlands in Eastern England, using an ecosystem function framework. In a pilot study, residents were able to allocate a relative importance to woodland ecosystem services which were then related to “regulation”, “habitat”, and “production” or “information” functions. However residents also placed importance on negative services or “dis-services” associated with the woodland ecosystem. Therefore a fifth category of “dis-services” was included in the main survey which included 84 local residents, three woodland owners, three government institutions, and six representatives from conservation groups. Each of the four groups placed greatest importance on services associated with habitat (16–39% of the total importance) and information (30–50%) functions suggesting, in this example, mutual interest in the use of woodlands as a habitat or recreational resource. By contrast a potential area of difference was the particularly high importance placed by one owner on dis-services such as fly tipping. In addition the woodland owners placed higher importance (10–20%), than local residents and conservation groups (7–9%), on the productive services of the wood. This suggests a need for communication when production-related operations affect recreation. The ecosystem function framework appears to be a useful approach for highlighting potential tensions and areas of mutual interest in the management of semi-natural ecosystems.     

In Vino ‘No’ Veritas: impacts of fraud on wine imports in China

China is one of the largest wine importing countries in the world and is poised for continued import growth in the future. Increased wine purchases throughout China have given rise to persistent fraud where fake wines are packaged and sold with counterfeit contents and labels. For exporting countries like France, counterfeit wines displace market share, damage foreign brand reputation, and cause distrust in consumers who are aware of counterfeiting problems throughout the country. We examine the impact of fraudulent wine events (as measured by negative media reports) on Chinese wine demand differentiated by supplying country. We employ the Rotterdam demand system and a switching regression procedure to estimate import demand and compare results across different media variable specifications. Results consistently show that negative reports disproportionately affect French wine regardless of how the media variable is specified. This is not surprising because most fraudulent events involve French wine counterfeits.     

Revealing different understandings of soil held by scientists and farmers in the context of soil protection and management

This paper aims to analyse and draw together results from similar studies in England, Switzerland and France which investigated farmers’ understanding of soil and compared it with that of scientists, researchers and advisors (collectively called scientists in this analysis). A range of methods were used across the three studies and different theoretical approaches, looking at forms of knowledge, local practice of knowledge production and conceptions of reality, were employed to explain the results. Despite the different contexts, methodologies and theoretical approaches in the three studies, the results reveal similar patterns of difference in farmer and scientist understanding of soil. In the English study, farmers demonstrate a ‘know-how’ form or intuitive working knowledge of soil while advisors rely on scientifically established forms of ‘know-why’ and seek to understand and explain soil processes. Similarly in the Swiss study farmers’ and scientists’ differing perceptions are directed and shaped by their respective aims, methods and context of work. In the French study, farmers and researchers are shown to have different conceptions of soil, they attribute different meaning to the same activities, and use different words and language to describe the same features. In all three studies understanding is shown to be cultural and contextual, as such an integrative theoretical framework is proposed.     

An evaluation framework for earthquake-responsive land administration

In recent years earthquakes and their secondary hazards have claimed the largest number of lives of all large natural disasters. Some of the world’s most earthquake-prone zones are also areas of high population density. The impact is magnified by vulnerability factors including non-enforcement of building codes, knowledge gaps, urban poverty and poor governance capacity to manage and reduce earthquake risks. Poor security of land tenure and property rights increases the vulnerability of people and affects their ability to respond to natural disasters.Earthquake recovery and reconstruction provides very significant challenges for land agencies, with these challenges differing from one country to the next due to differences in the local context. Drawing on contrasting case studies in Haiti, Nepal and New Zealand this paper identifies the common post-earthquake land administration functions and challenges that may apply to many contexts. These lessons provide land agencies and other key stakeholders with a summary of the challenges an earthquake poses for land administration at different post-disaster stages. We also discuss the policy and regulatory, institutional, operational and preparedness lessons for land administration. From these lessons we propose a framework for evaluating the earthquake-responsiveness of a land administration system. This framework can be used by a land agency in an earthquake prone region, or where an earthquake has recently occurred, to assess what challenges to land administration might occur in the event of an earthquake, and the preparedness of their land administration system.     

森林生物多样性评价模型的改进

针对2002年的评价模型中的不足,提出了新的改进后的森林生物多样性变化的评价模型,并在我国第六次森林资源清查(1999～2003)资料的基础上,对1973～2003年我国森林生物多样性的变化进行了补充评价。评价结果表明:我国森林生物多样性的压力越来越大,压力指数由1973年的100,上升到2003年的199.10,上升了1.99倍;森林物种多样性总体的下降趋势已有一定幅度的改变,森林物种多样性指数增加了31.12%。森林生态系统多样性和森林生物多样性先逐渐上升,尔后又下降,第六次森林资源清查时又有所恢复,并分别上升了4.67个百分点和17.90个百分点。     

转变地质工作发展与服务方式的实践和建议

天津市地矿局注重加快转变经济发展方式,发挥地质工作优势,推进低碳清洁能源的开发利用创新和技术进步,紧紧依托地质工作的人才、技术和行业优势,加大清洁环保资源的勘查、研究、开发、利用。针对天津市水资源缺乏的情况,积极加强后备和应紧水源勘查。按照“两种资源,两个市场”的思路,通过实施中外合作勘查项目,以境外勘查工作为载体和平台,实施引进来和走出去战略,为天津市经济社会发展提供地质技术支撑。