MATHEMATICAL SIMULATIONS OF THE TOCCOA FALLS,GEORGIA, DAM-BREAK FLOOD1

ABSTRACT: Four dam-break models were selected for testing with an observed data set from the November 6, 1977, disaster at Toccoa Falls, Georgia. The Kelly Barnes Dam failure occurred with a 35-ft head of water and produced a peak discharge of 23,000 ft³/s. The selected models included: (1) Modified Puls (MP), (2) U. S. Army Corps of Engineers Gradually Varied Unsteady Flow Profiles (USTFLO), (3) National Weather Service's Dam-Break Flood Forecast (DBFF), and (4) U. S. Geological Survey's method of characteristics (MOC) coupled with a general purpose streamflow simulation (J879DB). Achieving a successful simulation was easiest with the MP model. The DBFF model required a moderate effort while the MOC-J879DB models required some data alterations and considerable effort. The USTFLO model failed to simulate this test case. In the stream segment near the dam, the computed peak stages were generally within 5 feet of the observed high water marks. Elsewhere, the peak stage results were much better, generally within 2 feet. The peak discharges computed by the models were generally within 20 percent of discharges estimated by slope area and contracted opening measurements, except near the dam where the MOC-J879DB model's results was 80 percent too high.     

安全工程本科的“工程型大安全”教学方案构建

“大安全”在安全科学技术教育界广为推崇。它的含义是指广泛适用于解决各个行业、各类组织安全问题的科学理论和方法。“大安全”是我国高等学校安全工程专业本科教育的基本目标之一 ,构建适当的课程教学方案是实现这一目标必需的途经。笔者围绕安全科学技术的研究对象———事故、研究内容———事故的发生发展规律、预防策略和救援方法 ,构建出一种安全工程专业本科的“大安全”课程教学方案。所构建的教学方案由通用于各行业的基础课、专业基础课和针对特定行业的专业课组成。方案中工程技术类课程占有主导地位 ,所以 ,可称为“工程型大安全”课程方案。统计分析表明 ,应用该方案所培养的学生就业面宽广 ,这种类型的课程教学方案符合市场需求     

A WATERSHED APPROACH TO ECOSYSTEM MONITORING IN DENALI NATIONAL PARK AND PRESERVE,ALASKA1

ABSTRACT: The National Park Service and the National Biological Service initiated research in Denali National Park and Preserve, a 2.4 million-hectare park in southcentral Alaska, to develop ecological monitoring protocols for national parks in the Arctic/Subarctic biogeographic area. We are focusing pilot studies on design questions, on scaling issues and regionalization, ecosystem structure and function, indicator selection and evaluation, and monitoring technologies. Rock Creek, a headwater stream near Denali headquarters, is the ecological scale for initial testing of a watershed ecosystem approach. Our conceptual model embraces principles of the hydrological cycle, hypotheses of global climate change, and biological interactions of organisms occupying intermediate, but poorly studied, positions in Alaskan food webs. The field approach includes hydrological and depositional considerations and a suite of integrated measures linking key aquatic and terrestrial biota, environmental variables, or defined ecological processes, in order to establish ecological conditions and detect, track, and understand mechanisms of environmental change. Our sampling activities include corresponding measures of physical, chemical, and biological attributes in four Rock Creek habitats believed characteristic of the greater system diversity of Denali. This paper gives examples of data sets, program integration and scaling, and research needs.     

移动Ad hoc网络路由协议的安全性分析与对策

移动Ad hoc网络是一种自组织、多跳的无线网络,由于其独特性能使移动Adhoc网络面临着比现有网络具有更大的安全挑战,其中路由安全对该网络的安全性起着关键性的作用。在介绍移动Ad hoc网络主要路由协议及其特点的基础上,笔者深入研究了移动Ad hoc网络路由协议中存在的黑洞、拒绝服务等安全漏洞;详细分析了几种主要的Ad hoc路由协议的安全性增强方案;根据不同路由协议的特点,分别提出了利用单向散列链改进距离矢量路由协议安全性的两种方案;分析了一种用于改善源路由协议安全性的方案的可行性。最后,指出了移动Ad hoc网络路由协议安全性问题的进一步改进和研究方向。     

A Routing and Scheduling System for Infectious Waste Collection

Most hospitals and clinics in Taiwan do not have on-site treatment facilities for their infectious waste and must rely on outside agencies for their collection and treatment. The problem of optimally routing and scheduling the collection of medical waste from a disperse group of facilities is recognized as a periodic vehicle routing problem. This study develops a computer system to solve the resulting optimization problem based on a two-phased approach proposed earlier. The first phase solves a standard vehicle routing problem to determine a set of individual routes for the collection vehicles. The second phase uses a mixed integer programming method to assign routes to particular days of the week. The computer system is user-friendly and consists of several Visual Basic programs while the geographical information system is incorporated to facilitate input and output interface and database management. An illustrative example for the infectious waste of 348 hospitals in the Tainan City area demonstrates the effectiveness of the system.     

CDM Projects under the Kyoto Protocol: A Methodology for Sustainability Assessment – Experiences from South Africa and Uruguay

Under the Clean Development Mechanism (CDM) of the Kyoto Protocol, industrialised countries may finance greenhouse gases mitigation projects in developing countries. The Kyoto Protocol explicitly requires that the CDM shall assist developing countries to achieve sustainable development. However, a clear definition of sustainability for CDM projects is still debatable. MATA-CDM (Multi-Attributive Assessment of CDM Projects) is an approach that facilitates a quantitative assessment of potential projects regarding their contribution to sustainable development. This paper presents applications of MATA-CDM in two different countries. In South Africa, the application was done mainly for academic and demonstrative purposes, whereas in Uruguay it was implemented together with the responsible Designated National Authority (DNA). The work in both countries included the selection of sustainability criteria and measurable indicators. Experts weighted the criteria using personal interviews and a multi-stakeholder workshop. This method was applied to three potential CDM projects in South Africa and one in Uruguay. Results show that under the conditions of this study, the MATA-CDM approach yet fails to yield a perfect quantitative overall sustainability assessment of CDM projects but that several findings could be useful to further develop the approach with the aim to translate the vague term sustainable development to a mainstream project level. Valuable experience was in particular collected with different stakeholder processes to perform criteria weighting.     

COARSE WOODY DEBRIS AND CHANNEL MORPHOLOGY: A FLUME STUDY1

ABSTRACT: In recent years, logs and other structures have been added to streams for the purposes of altering channel morphology to improve fish habitat. This flume study was conducted to evaluate the effects of coarse woody debris on local channel morphology. Wooden dowels were used to simulate the effects of individual logs in a stream, and scour depth and surface area were determined at the end of each test run. The maximum scour depth was significantly correlated (90 percent confidence level) with both the vertical orientation of the dowels and the channel opening ratio; the scour surface area was significantly correlated (90 percent confidence level) with both the flow depth and the vertical orientation. Upstream-oriented dowels caused relatively large streambed scour and also deflected flows toward the streambank. Downstream-oriented dowels generally caused less bed scour and appeared to provide better bank protection because flow was generally deflected from the bank. In conjunction with data from field studies, these results provide information on the effects of orientation, hydraulic function, and relative stability of coarse woody debris in streams.     

一种更加安全的密码技术——量子密码

信息安全技术备受世人关注,由于现有的加密方法存在着很多弊端,人们将目光转向了量子密码。根据量子力学中的海森堡不确定性原理,任何窃听者都无法窃听量子密码通信中的信息而不被发现,笔者正是从量子不确定性基本原理出发来研究量子密码技术的,结合量子密码协议在通信网络中的应用来探讨了在量子通信过程中量子密钥生成、分发的详尽过程及量子密钥的分发协议在通信中应该遵循的原则,介绍了当前实验研究的进展,分析了量子密码研究存在的问题,并针对这些问题提出了一些建设性意见,最后对量子密码的发展前景和方向进行展望。     

重大事故的应急救援预案编制技术

重大应急预案编制是安全生产的一项重要基础工作 ,对于提高应急救援能力 ,控制事故与灾害的恶化 ,保障人民安全具有重大意义。笔者从应急预案编制的技术层面上 ,论述了应急预案的基本框架和应急预案体系 ;认为该体系可以由 6个一级和 2 0个二级的核心要素构成。其中 ,应急策划是制定应急预案的技术基础 ,包括风险评价、资源分析和法律法规要求 3个二级要素 ;应急准备包括机构与职责、应急设备设施与物质、应急人员培训、预案演练、公众教育和互助协议 6个二级要素 ;应急响应是应急预案中核心的内容 ,包括现场指挥与控制等 1 1个二级要素。所提出的应急救援预案文件体系 ,建议一般按照四级文件形式的设想 ,应急预案的目标是提高整体应急能力 ;建议把应急预案的具体编制过程划分为 6个基本的步骤 ,对于预案编制与实施应实现持续改进的机制     

重大工业隐患的地域监控体系研究

系统地分析了重大工业危险源与事故隐患 ;研究了地域监控、预警、应急预案的体系建设以及隐患监控的新技术应用基础 ;提出了职业安全卫生监控体系中的工业危险源和隐患监控。笔者认为 :应该分为过程安全监控和安全目标监控两个层次