SOLUTION OF A WATER RESOURCES PROBLEM WITH ECONOMIES OF SCALE BY LINEAR PROGRAMMING1

ABSTRACT Both because of its effectiveness and ease in use, linear programming has become progressively popular in water resources planning problems. Yet, the assumptions of linear construction costs can be misleading. Diseconomies of scale in construction can be handled by successive approximations to the cost function but problems with economies of scale yield paradoxical results when piecewise approximations are used. If significant economies of scale exist in only one facility, the solution to problems of this nature can be found using normal linear programming codes by successively adjusting the unit construction cost on that single facility to iteratively work toward the true optimal solution.     

Adaptive Management and Watersheds: A Social Science Perspective1

Abstract:  Adaptive management is often proposed as the most effective way to manage complex watersheds. However, our experience suggests that social and institutional factors constrain the search for, and integration of, the genuine learning that defines adaptive management. Drawing on our work as social scientists, and on a guided panel discussion at a recent AWRA conference, we suggest that watershed‐scale adaptive management must be recognized as a radical departure from established ways of managing natural resources if it is to achieve its promise. Successful implementation will require new ways of thinking about management, new organizational structures and new implementation processes and tools. Adaptive management encourages scrutiny of prevailing social and organizational norms and this is unlikely to occur without a change in the culture of natural resource management and research. Planners and managers require educational, administrative, and political support as they seek to understand and implement adaptive management. Learning and reflection must be valued and rewarded, and fora established where learning through adaptive management can be shared and explored. The creation of new institutions, including educational curricula, organizational policies and practices, and professional norms and beliefs, will require support from within bureaucracies and from politicians. For adaptive management to be effective researchers and managers alike must work together at the watershed‐scale to bridge the gaps between theory and practice, and between social and technical understandings of watersheds and the people who occupy and use them.     

在我国中小企业推广PDM时机尚未成熟

目前我国CAD的初步应用(绘图、工艺设计)在机械行业大部分企业已基本普及。在甩图板——集成化产品信息管理——网络系统集成——CIMS的技术路径上,PDM(产品数据管理)技术已进入大力推广阶段。然而,就我国目前的实际情况来看,PDM在中小企业的普及尚有一定难度。其原因在于PDM具有较高的技术成分,涉及部门范围广,从现行管理系统过渡到该方案所需时间较长,以致于其中不确定因素多,风险大,初期投资大而短期收益少。而大多数中小企业在市场竞争中处于劣势,盈利水平和流动资金有限,人才流动性大,并且难以承受长时间的二次开发过程。     

企业生态创新的维度构成与量表开发研究

生态创新是促进经济绿色增长、应对气候变化的重要手段与核心工具,但目前关于生态创新的测量量表相对缺乏。通过对国内外生态创新的文献的系统梳理,结合开放式问卷调查和内容分析,本研究初步构建了由16项条款构成的初始测量量表。运用探索性和验证性因子分析,确定了由11项条款构成的生态创新测量量表,包含生态管理创新、生态工艺创新和生态产品创新三维度。本研究识别了生态创新的内部构成与确定了其测量量表,为深入研究生态创新的前置因素、生态创新与企业绩效之间的关系奠定了良好的基础,同时也为评价与比较不同企业的生态创新水平提供了支撑。     

Predicting the Thermal Effects of Dam Removal on the Klamath River

The Klamath River once supported large runs of anadromous salmonids. Water temperature associated with multiple mainstem hydropower facilities might be one of many factors responsible for depressing Klamath salmon stocks. We combined a water quantity model and a water quality model to predict how removing the series of dams below Upper Klamath Lake might affect water temperatures, and ultimately fish survival, in the spawning and rearing portions of the mainstem Klamath. We calibrated the water quantity and quality models and applied them for the hydrometeorological conditions during a 40-year postdam period. Then, we hypothetically removed the dams and their impoundments from the models and reestimated the rivers water temperatures. The principal thermal effect of dam and reservoir removal would be to restore the timing (phase) of the rivers seasonal thermal signature by shifting it approximately 18 days earlier in the year, resulting in river temperatures that more rapidly track ambient air temperatures. Such a shift would likely cool thermal habitat conditions for adult fall chinook (Oncorhynchus tshawytscha) during upstream migration and benefit mainstem spawning. By contrast, spring and early summer temperatures could be warmer without dams, potentially harming chinook rearing and outmigration in the mainstem. Dam removal might affect the rivers thermal regime during certain conditions for over 200 km of the mainstem.     

河北省高校社会体育专业培养目标及学生满意度调查分析

运用文献资料法、问卷调查法、数理统计法和对比分析法,对我省社会体育专业本专科院校的培养目标情况、学生收获和满意度情况进行调查分析。研究结果表明,中环院社会体育专业学生对课程体系设置的满意度最高,就业信心指数最大。进一步分析可知,以社会体育产业为目标定位、以能力本位为教育模式对社会体育专业学生的培养具有一定的优越性     

PREDICTION OF TWO-YEAR PEAK STREAM-DISCHARGES USING NEURAL NETWORKS1

ABSTRACT: The cascade correlation neural network was used to predict the two-year peak discharge (Q₂) for major regional river basins of the continental United States (US). Watersheds ranged in size by four orders of magnitude. Results of the neural network predictions ranged from correlations of 0.73 for 104 test data in the Souris-Red Rainy river basin to 0.95 for 141 test data in California. These results are improvements over previous multilinear regressions involving more variables that showed correlations ranging from 0.26 to 0.94. Results are presented for neural networks trained and tested on drainage area, average annual precipitation, and mean basin elevation. A neural network trained on regional scale data in the Texas Gulf was comparable to previous estimates of Q₂ by regression. Our research shows Q₂ was difficult to predict for the Souris-Red Rainy, Missouri, and Rio Grande river basins compared to the rest of the US, and acceptable predictions could be made using only mean basin elevation and drainage areas of watersheds.     

SOCIO-ECONOMIC IMPACTS OF RURAL WATER SUPPLES1

ABSTRACT Development of community water systems in rural areas through the Farmers Home Administration, U. S. D. A., has been marked since the initiation of the program in the early 1%O's. System development in Mississippi has been very rapid and now numbers the largest among the states excepting Texas. Concurrent with this growth, however, has been a concern for operational quality and efficiency as well as questions of community impacts. The paper is purposed with describing the results of research conducted relative to these areas and methods currently being employed or considered for dealing with problematic items.