Service Gated Discrete-time Polling System with Bernoulli Feedback

This paper analyzes asymmetric limited gated service polling system with Bernoulli feedback. By the imbedded Markov chain theory and the probability generating function method,The authors derive the generating function of intervisit time , polling cycle time , service time of each station and queue length in the each station .Furthermore , the successive sojourn time of customer C in ith station (i=1,2,...N) and queue length after the (m-1)th service are obtained.     

基于数字图书馆的农业移动信息服务集成模式研究

本研究主要介绍了移动数字图书馆的概念、特点及服务三农的新模式,提出建设云南农业数字图书馆,全面进行数字资源建设整合;完善“三农通专家咨询服务平台”服务功能模式,深入科普基地全面进行需求分析;研究移动信息服务集成的相关理论,构建完善的理论体系;构建适合云南本地特色的移动信息服务新模式四方面研究云南农业信息移动服务集成模式,同时对移动农业信息服务面临的问题进行了讨论。     

农业信息网站服务质量评价指标优化研究

提高农业信息网站服务质量是有效解决农业信息化发展瓶颈的方法之一。科学的网站服务质量评价,可以提高用户获取信息的效率,同时网站设计者通过了解影响其服务质量的主要因素,可以优化网站资源配置。笔者参考服务质量管理的有关原理和已有的指标设计方法,构建了一个农业信息网站服务质量评价通用模型,利用R型系统聚类法探索描述性指标项优化问题,以避免指标项之间存在的相关、重复情况,最后以40个茶叶信息网为实验对象进行数据采集与分析,构建农业信息网站服务质量评价影响因素的多元回归模型,得出在信息服务系统构建过程中影响信息服务质量的重要因素。     

Service Life Prediction of Concrete Structures under Chloride Environment

The problems rendered from the conventional time marching, referring to stepwise time marching scheme (STMS) adopted in boundary element method (BEM) for chloride diffusion in concrete structures, were investigated, and a new time marching, referring to initial time marching scheme (ITMS) in BEM, was developed for evaluation of service life of the concrete structures under chloride environment. Results of the numerical examples show that the ITMS-BEM proposed can eliminate domain integral and simplify the computational model, so that the stability in iteration process can be improved, resulting in better efficiency and accuracy, compared with the STMS-BEM. It can also be concluded that the dimensions of the diffusion of chloride can affect the service life of the concrete structure significantly, which should be taken into account in structural design.     

芦苇沼泽湿地开发为稻田前后生态系统 服务价值对比研究——以丹东鸭绿江口湿地国家级自然保护区为例

芦苇沼泽湿地在调节气候、净化污水、促淤防蚀、维持生物多样性等方面有着重要的作用。但一直以来芦苇沼泽湿地被当作开发的对象，通过市场价值法、造林成本法、影子工程法、替代法对丹东鸭绿江口湿地国家级自然保护区的芦苇沼泽湿地的生态系统服务价值进行了评估，并假设其芦苇沼泽湿地全部开发为稻田，并对其生态系统服务价值进行了评估。结果表明，保护区内芦苇沼泽湿地的生态系统服务价值为12395.0万元。开发为稻田后生态服务功能价值为8925.4万元，生态系统服务价值减少了28%。芦苇沼泽湿地生态系统服务功能为8项，主要表现在水分调节功能价值和控制侵蚀、保护土壤价值分别占整个芦苇沼泽湿地生态系统服务价值的35%和32%，开发为稻田后生态系统服务价值减少为4项，主要表现为物质生产价值，占整个生态系统服务价值的75%。     

Research and Application Development Pattern Based of a Collaborative Product on Service-on-Demand Mode

According to the instant demand coming from the collaborative product development of small and medium manufacturing enterprises, this paper brings out a kind of a collaborative product development service-on-demand mode based on web-service, and a framework for this service-on-demand mode are also given. According to these, this research sets up a web based collaborative product development service platform, analyzes the function structure, service flow and the main implement techniques. The service pattern and the platform have already applied to collaborative product development in small and medium manufacturing enterprises and have helped to increase technique innovation, reduce the total time and cost in development process.     

适用于语音业务的MANET机会路由机制

传统路由机制需要在源和目的节点之间预先建立端到端路径,当链路质量较差时,频繁地建立路径会影响业务的服务质量。为支持实时语音业务,提出一种机会路由机制,该机制并不预先建立连接,而利用多个路由请求和路由应答消息建立转发列表,表中的节点利用与其他节点的相遇机会对数据包进行转发,并根据转发节点的优先级对转发数据包的数量进行限制。仿真结果表明：机会路由机制能够减小语音业务的端到端时延,提高分组投递率,可以在不稳定的信道为语音业务提供服务质量保证。     

安徽省农业生产性服务业现状及发展效率评价

旨在对安徽省农业生产性服务业现状进行了解并对其发展效率进行评价,以期为促使安徽农业生产性服务业发展提供可取的参考建议。以安徽省为案例对象,了解其农业生产性服务业的发展现状,同时从时空视角运用数据包络分析法对其发展效率进行评价。发现2007—2015年安徽省主要是因为规模效率导致DEA无效;2015年各地区农业生产性服务业综合效率值差异较大,仅宿州、蚌埠、芜湖等六市的综合效率值为1,最低值为黄山市,仅为0.365。基于此,认为产业发展层面应推进产业链融合、重视对科学技术的投入以及鼓励政策支持;空间层面应平衡各地区农业生产性服务业的发展;产业间合作层面应促使农业生产性服务业与特色农业相互融合。最后指出不足之处并展望之后的研究方向。     

Study on Connotations of Industry Park Leisure Culture in Kunming City: A Case Study of Dounan International Flower Industry Park

Taking Dounan International Flower Industry Park in Chenggong District for example, neighboring environment and other tourism resources are combined on the basis of the five planned functional areas(fl ower trade and expo area, comprehensive service and distribution area, post-harvest treatment and information service area, international fl ower research and exhibition area, international fl ower enterprise exhibition and supporting service area), and recreational functions designed to build it into a comprehensive industrial and recreational park with sightseeing, leisure, and science popularization functions. Integration and adjustment of leisure spaces in Dounan International Flower Industry Park focus on the following aspects: re-plan the layout of leisure spaces; industrial park promotes restructuring of leisure spaces; residential functions are transferred to new leisure spaces; commercial service industry promotes leisure spaces; government transforms its functions and expands functions of leisure spaces; new technology pushes forward the change of residents' leisure time structure, so as to improve leisure functions of Dounan International Flower Industry Park in an all-around way.     

Existing Frame Structure in Reconstruction and ExtensionProject in Security Analysis

Structure security is the most main structural reliability, at the request of active service in time to make a frame structure security assessment, in safe premise to prolong the service life, and has a certain social significance and economic benefits. Combining with the actual situation reconstruction projects, using the theory analysis frame structure of the active safety, the finite element SAP2000 on the original structure and rebuilt structure modal analysis, the effect of the structure security index that contrast reconstruction of the frame structure than the frame structure of the security it can improve.     

Research on QoS Strategy of Web Server Cluster Application Based on Request Classification and Request Admission Control

The increase of requests often results in performance degradation of the web server cluster. The quality of service (QoS) expected by users can't be guaranteed. This is the problem that service-level web server cluster must cope with. In this paper, two strategies are proposed including classification of the user requests and request admission control, the different quality of service can be reached and the QoS of service-level users is guaranteed. The simulation experiments proved, the load balance of the system is improved and average response time of the system is decreased.     

模糊控制系统的垂直切换判决算法分析

针对模糊控制系统中切换时延较长和切换次数较多的问题,研究了一种基于模糊控制系统的垂直切换判决算法。在基于信号强度判决时将RSS作为门限值,提高系统判决能力;同时,将网络参数和服务类型作为判决因素,结合层次分析法引入并行的模糊控制系统,缩短了切换判决的时间、选择适合用户的最佳网络,做出垂直切换。仿真结果表明,该算法减少了切换次数,降低了切换时延,增强了系统的性能。与传统的切换算法相比较,该算法对切换的判决因素考虑的更全面,兼顾了用户终端的使用环境及成本问题,有效地保证了网络的服务质量。     

日光温室小气候预报技术研究

为了提高设施农业气象服务水平,促进中国设施农业发展,通过对日光温室内外气象条件对比观测,分别采用BP神经网络、逐步回归和能量平衡原理构建了温室内气温预报模型,探讨能适用于业务服务的小气候预报技术方法。结果表明,基于BP神经网络的预报模型虽预报精度高,由于种植作物生长特性差异较大,缺乏服务的广适性;通过能量平衡原理构建的预报模型机理性强,但相关参数难以获得,预报精度差,服务时效短;采用逐步回归方法构建的温室温度预报模型较前两者具有比较优势,且预报时效可以为未来的1~7天,比较适合于目前气象部门开展设施农业气象服务。     

中国棉花生产与科技发展

阐述了我国棉花生产的发展、波动及其原因,剖析了棉区布局的演变和生产的宏观调控方法。同时对我国棉花科研的成就和问题进行了总结分析。并从生产、科研、行政和服务等领域,提出提高和发展棉花生产和科研水平的措施。     

青海省农作物品种管理数据库系统的建立及应用技术研究

青海省首次建成并使用的“青海省农作物品种管理数据库系统”是促进全省品种管理、合理推广应用优良品种，为社会提供品种咨询服务业务的信息系统工程，对发展农业生产，提高良种覆盖率具有很高的实用价值和理论意义。     

Container river services and gateway ports: Similarities between the Yangtze River and the Rhine River

Abstract: Container ports located in a delta of navigable waterways generally strive to develop the inland river services as a competitive transport mode, with a view to serving local and distant hinterland regions. The spatial and functional development of river‐based container networks is location‐specific and time‐specific. While each barging network and associated seaport system has its own dynamics, similarities in development patterns cannot be excluded. This paper discusses similarities and dissimilarities between the spatial and the functional development of the container river service networks of the Yangtze River and the Rhine River. It is shown that the Yangtze service network has the tendency to converge, in more than one aspect, with the (historical) development pattern of inland container services in the Rhine basin.     

The Suburbanization of Producer Service Employment

ABSTRACT. Washington DC is the center of the nation's ninth largest metropolitan area (PMSA), home to 4.4 million people and 2.9 million employees in a web of 25 separate, autonomous municipalities spanning three states and the District of Columbia. As such, the region is a good place to analyze the pattern of suburbanization of producer service employment over the past 25 years. In addition to overall suburbanization, the metropolitan area has seen changes in the nature and role of its dominant economic force, the federal government. Direct federal employment has stagnated while federal contracts to private companies have soared. Producer service employment seemed to increase in importance in jurisdictions away from the region's core, simultaneous with increases in total employment, following increases in federal contracting, and independent of increases in federal employment. These trends have affected the growth of producer service employment across the metropolitan area, encouraging their suburbanization. By subjecting our initial models to sub-sector data and analysis of temporal trends in the coefficients, we uncover the uniqueness of legal services and additional evidence of suburbanization over time.     

日光温室揭帘时间农业天气预报指数的确定

为了提升气象服务能力,合理掌握日光温室保温帘揭盖时间,进而提升生产水平和经济效益,利用日光温室揭开保温帘时间的数学模型,对安塞冬季日光温室保温帘揭开时间进行分析验证。根据安塞县温度和光照气候资料,计算出安塞冬季各旬平均揭帘时间,并利用数学模型和天气预报,建立了揭帘农用天气预报指数,用于指导农业生产。结果表明,数学模型适合在安塞应用,天气预报指数符合生产实际,指导意义明确,按计算所得保温帘揭开时间达到了预期效果。     

Intelligent Building Design--A Systematic Integration of Architecture and Technology

The intelligent building design needs a total new method. It is an integration of electronic technology and other related technologies such as structure, system, service and management ones. As for the architecture design itself, it should include the infrastructure accommodating telecommunication, day lighting, lighting and HVAC systems. At the same time, the security, fire safety and operation controls should be considered as well.     

农业社会化服务供给博弈分析

农业社会化服务主体在农业社会化服务体系中扮演重要角色,各服务主体提供的服务能否为农户带来长远利益并最终被农户持续接受是农业社会化服务持续发展的关键问题。本文以博弈论为基础,通过分析公共服务机构及中间服务组织与农户之间的博弈过程发现：公共服务机构和中间服务组织为农户提供的社会化服务的质量及其自身的成本收益成为影响农业社会化服务持续发展的重要因素,农业社会化服务若要持续稳定的发展,离不开服务主体高水平的服务和农户的积极参与。只有适应市场需求,真正能够给农户带来实惠的服务才会最终被农户所接受。