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1.
流域泥沙灾害与泥沙资源性的研究 总被引:5,自引:0,他引:5
泥沙灾害与泥沙资源性是流域泥沙的重要属性,二者在一定条件下可以相互转化。本文论述了泥沙淤积、泥沙冲刷、岸滩崩塌、山地崩塌与泥石流、粗沙淤积的土地沙化等泥沙灾害,指出泥沙灾害具有时空分布的不均匀性、渐变性或突发性、群发性、转化性及危害严重性等;流域泥沙资源化的主要途径包括填海造陆及造地、引洪淤灌、堤防淤临淤背、建筑材料、湿地形成(河流、湖泊与河口海岸)等,指出流域泥沙资源化及其优化配置既要解决思想观念、基本理论、目标效益等方面的问题,还要考虑与水资源联合配置问题。 相似文献
2.
A play-the-winner-type urn design with reduced variability 总被引:1,自引:0,他引:1
Anastasia Ivanova 《Metrika》2003,58(1):1-13
We propose a new adaptive allocation rule, the drop-the-loser, that randomizes subjects in the course of a trial comparing
treatments with dichotomous outcomes. The rule tends to assign more patients to better treatments with the same limiting proportion
as the randomized play-the-winner rule. The new design has significantly less variable allocation proportion than the randomized
play-the-winner rule. Decrease in variability translates into a gain in statistical power. For some values of success probabilities
the drop-the-loser rule has a double advantage over conventional equal allocation in that it has better power and assigns
more subjects to the better treatment.
Acknowledgments. I thank Stephen Durham, the associate editor, and the referees for their helpful suggestions. 相似文献
3.
Ph. D. Candidate:Chen Xue-fengState Key Laboratory of Offshore Coastal Engineering Dalian University of Technology Dalian China e-mail: cxfeng @ student dlut. edu.cn 《水动力学研究与进展(B辑)》2003,15(6)
The reflection coefficient of perforated caissons and the total horizontal forces acting on them were experimentally and numerically analyzed and discussed when wave propagates normally. To consider the viscosity effect of fluid and nonlinear action of waves on structures, the VOF (Volume Of Fluid) method combined with the k-ε turbulence model was used to simulate the interaction between waves and structures. Governing equations were solved with the finite difference method. Through 2D experimental study in the wave flume, the empirical relationship between the reflection coefficient of perforated caissons and the main affecting factors were obtained from the experimental data using the least square method. Also the correlation between the ratio of the total horizontal force acting on perforated caisson and the force acting on solid caisson and the main affecting factors were regressed from the experimental data. 相似文献
4.
王晓东 《吉林商业高等专科学校学报》2005,(4):77-78
本文在体育锻炼能够增强体质,提高健康水平的生物学基础上和群众体育锻炼与专业训练的区别上,提出群众体育锻炼中如何合理安排运动量。 相似文献
5.
For reasons of political feasibility, emission trading systems may have to rely on free initial allocation of emission allowances in order to ameliorate adverse production and employment effects in dirty industries. Against the background of an emerging European‐wide emission trading system, we examine the trade‐off between such compensation and economic efficiency under output‐based and emissions‐based allocation rules. We show that the emissions‐based allocation rule is more costly than the output‐based rule in terms of maintaining output and employment in energy‐intensive industries. When the international allowance price increases, the inferiority of emissions‐based allocation vis‐à‐vis output‐based allocation becomes more pronounced, as emission subsidies drastically restrict efficiency gains from international trade in emission allowances. 相似文献
6.
G. H. BURROWS 《Abacus》1994,30(1):50-64
The extent to which allocated common costs should influence business decisions remains controversial in management accounting. In the finance and investment literature this issue is generally ignored or dismissed by appeals to the'incremental' principle. This article presents an historical analysis of allocations in long-run investing and pricing decisions. It is demonstrated that seminal figures in the development of both investment and price theory were conscious of the need for firms to cover common costs and generally favoured some form of allocation. The anti-allocationist position is shown to be of relatively recent origin and to have caused an inconsistency in the management accounting literature in the treatment of common costs. European costing theory is shown to have been consistently allocationist. Evidence of a return in the recent U.S. literature to the older Anglo-American, and continuing European, allocations tradition is presented. 相似文献
7.
Efficient Liability Rules: Complete Characterization 总被引:5,自引:0,他引:5
Received May, 18, 2000; revised version received March, 19, 2001 相似文献
8.
9.
Most decision making research in management accounting remains focused on cost information in a production context. Little is known on the relevance of customer profifitability analysis (CuPA) reports, which more accurately reflect revenue and marketing support variations acrosscustomers, for marketing decisions. This study uses an experimental design to examine the impact of such reports on resource allocation decisions (that affect the firm's profits) in marketing environments varying in complexity. The main result of the experiment suggests that the value of CuPA reports depends on the complexity of the marketing setting. Only in a highly complex marketing setting do they enhance resource allocation decisions and resultant firm profitability. Conversely, in the simple marketing environment, decision makers can combine their traditional volume-based cost data with other available types of feedback to perform as well as under a more accurate CuPA report. These findings on complexity contrast with those of a prior study in a production context ( Gupta and King, 1997 ). It is argued that improvements in the current research design, in the form of regularly updated profitability reports and concerning accuracy, increase the relevance of CuPA reports in a complex marketing setting. 相似文献
10.
对合肥市房地产业现状的几点看法 总被引:1,自引:1,他引:0
特定社会的分配关系总是由该社会的生产资料所有制关系和劳动力所有制关系决定的。社会主义初级阶段不成熟、不发达的生产资料公有制和劳动者劳动力发展不充分、不平衡决定了在分配上只能实行按劳分配和按要素分配相结合的制度。这是马克思主义分配理论的重大突破和巨大发展 , 相似文献