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21.
With the rapid increase of the Internet user and widely application of Web,the current network technology is facing great challenge. More and more multimedia operations occupy plenty of bandwidth,and result in the network congestion. Therefore,people begin to use QoS to utilize the bandwidth effectively,and ensure the transport of the emergent operation data. The paper introduces the protocols and basic components of QoS,then expatiates the conception and the basic principles of policy control QoS, moreover,emphasizes the structure model of policy control QoS and how it runs. At last,it introduces the transport process of data packets under the control of policies in a policy control QoS system,and how to make the policies in the real world. 相似文献
22.
The standard Linux is a typical time-sharing system, it has a poor real-time performance. But according to the applications of the Linux OS are expanding on real-time domain, it becomes necessary to enhance the performance of the Linux system. This paper analyses the schedule policies and schedule algorithms of the Linux kernel, and discusses several different kinds of methods about enhancing real-time performance of the Linux system from the total Linux system. They authors summarizes the current research's developments of the Linux system. 相似文献
23.
This paper researches the behavior difference among government,banks and enterprises and how it affects soft budget constraints of enterprises and non-performing loans of banks based with dynamic game.The game model suggests that government will give banks some assistance and let them refinance enterprises,especially government has strong(incentive) to sustain SOEs in China's transitional economy.Banks will do it if the assistance from government is more than the loss from refinance enterprises.In addition the value of liquidation of enterprises and the new loans affect banks' refinancing old enterprises. 相似文献
24.
25.
The analysis of China wind power industry 总被引:6,自引:0,他引:6
The development course of China wind power industry is reviewed by six stages. National policies on wind power industry are elaborated from the aspects of laws & regulations, planning, finance & taxation and electrovalence policy. And these policies have played an important supporting and regulating role in the development of wind power industry. The development status of China wind power industry is analyzed based on wind turbine installed capacity, wind power output and their growth rate. It is explained that national wind turbine manufacturers have kept developing and become strong by the data of new global installed capacity share of mainland wind turbine manufacturers in 2013 and the new global market share of 8 domestic enterprises among the world top 15 wind turbine manufacturers. But there are still 5 key problems which influence the development of national wind turbine need to be solved, including lack of top-level design, abandon and restriction wind power seriously, lack of R&D abilities, some of the key parts relying on imports and wind turbine facing a quality guarantee dilemma. Taking Sinovel Wind Group Co. Ltd. and Xinjiang Goldwind Sci & Tech Co. Ltd., the two leading companies as an example, their performance is analyzed and it’s pointed out that the wind industry must keep vigilant after the overspeed development. The enterprises should try to avoid neglecting cultivating their inner core competitive ability, including technology advancements and products reliability. Occupying the market with low price competition and expanding blindly is also not desirable. At last, the development prospects of our country’s wind power industry are analyzed and three proposals are put forward. 相似文献
26.
Irrigation and food security in the 21st century 总被引:1,自引:0,他引:1
Global food projections indicate that food prices in the next threedecades will likely be stable or decline, but progress inreducing malnutrition in developing countries will be slow. Smallshortfalls in crop productivity growth would lead to rising foodprices and worsening malnutrition. Increased food production fromirrigation is essential, and will require expansion of irrigatedarea and water supplies, and improved efficiency of use of existingwater supplies. Neither of these growth factors will prove easy, andboth will require complex institutional and policy reforms. Failureto meet food production needs through efficient expansion andintensification of irrigated agriculture would increase pressure onland resources and hasten the process of environmental degradation.Irrigation and water development strategies have been hampered bya lack of understanding of the links between water scarcity, foodproduction, food security, and environmental sustainability.Research to improve this understanding would have high payoffs. 相似文献
27.
周鹏飞 《中国农村水利水电》2004,(11):108-110
农村水电是国家重点支持的农村公共基础建设,农村水电的发展可有效改善农村地区基础设施建设水平,促进当地经济社会发展;对缓解我国生态环境压力,改善人民生存条件和质量意义重大。分析了农村水电公益性、生态性、永续性等农村水电特点,按不同时期回顾分析了过去几十年中政策措施环境对农村水电发展的影响,并针对目前农村水电发展存在的问题,提出新时期农村水电发展所需的政策措施环境建议。 相似文献
28.
Evaluating the Impact of Irrigation and Drainage Policies on Agricultural Sustainability 总被引:3,自引:0,他引:3
Farmers in the Broadview Water District in central Californiahave been improving irrigation practices in response to risingirrigation water prices and reductions in water supply since1989, when incentive policies were first implemented to reducethe volume of subsurface drain water generated in theDistrict. The average salinity of water deliveries hasincreased, over time, as the District has recycled largeamounts of drainage water to achieve regional restrictions ondrainage water discharge. We review irrigation and drainageactivities in Broadview since 1986 with an emphasis on thesustainability of crop production when drainage discharge islimited. Average cotton yields in Broadview have declined inrecent years, both nominally and in comparison with averageyields reported for the large county in which Broadview islocated. Average tomato yields in Broadview have increased inrecent years, but county-wide yields have exceeded Broadviewyields with greater frequency than in the late 1980s. Theseobservations suggest that average crop yields in Broadview maybe starting to reflect the increasing salinity of soil andwater resources, which may be due in part to persistentrestrictions on drainage water discharge. 相似文献
29.
中国是渔业大国,但与其他渔业大国相比,存在显著不同的发展环境、条件和特点。本文在以往讨论我国渔业大国的基础上,综合学者的研究成果,以"大国效应"为视点,讨论我国渔业大国现象特征、研究其规律;归纳分析了秘鲁、日本和前苏联等渔业大国的"优势陷阱";对我国渔业战略发展提出积极运用渔业大国效应、保持领先发展战略的政策建议。 相似文献
30.
孙永侠 《国家林业局管理干部学院学报》2013,12(1):47-50
我国森林资源总量居世界第五位。当前,由于法律的缺位、体制的不健全、监管的缺失和资金短缺等因素造成了我国森林保险体制停滞不前甚至萎缩的现象。建议完善林权流转体系,出台专门法律法规,建立林区数据检测共享制度,设立政策性农业保险公司等措施,促进我国的森林保险体制的可持续发展。 相似文献