橡胶沥青的输送和计量

橡胶沥青作为道路工程中的高温、高粘度介质,想要成功地将其泵送可能并不容易,而进行橡胶沥青的计量则更具挑战性。由于胶粉的磨蚀性,使用机械式的齿轮流量计已被证明是不可靠的。因为随着时间的推移,胶粉对齿轮的磨损会造成啮合齿轮打滑,由此造成的测量误差会超过精度许可范围。     

Factors Affecting Knowledge,Perceptions, and Attitudes Regarding North Carolina Coastal Reserve Management

During the period May 25–October 28, 2007, we collected data in face-to-face interviews on four sites in the North Carolina Research Reserve system. We subsequently conducted analyses on the effects of education, income, length of visitation, and frequency of visitation on visitor knowledge, perceptions, and attitudes regarding management. Visitors to the sites were well-educated, listed incomes above the state median, and were racially homogeneous. At the overall level, the majority (63%) knew who owned the sites, but only 43% correctly identified the managing agency. The majority also believed that overall conditions at the sites were stable, although those that had been visiting longer perceived conditions as deteriorating. Education was positively correlated with knowledge of ownership and management, and with support for additional rules and enforcement. Neither income, nor frequency of visitation showed any correlation with any of the dependent variables at the overall level. Some site-specific findings differed from the overall findings and varied from site to site. These differences were addressed individually.     

Reverse time-restricted shortest paths: Application to air traffic management

In this paper, we consider a particular class of network flow problems that seeks a shortest path, if it exists, between a source node s and a destination node d in a connected digraph, such that we arrive at node d at a specified time τ while leaving node s no earlier than a lower-bounding time LB, and where the availability of each network link is time-dependent in the sense that it can be traversed only during specified intervals of time. We refer to this problem as the reverse time-restricted shortest path problem (RTSP), and it arises, for example, in the context of generating flight plans within air traffic management approaches under severe convective weather conditions. We show that this problem is NP-hard in general, but is polynomially solvable under a special regularity condition. A pseudo-polynomial time dynamic programming algorithm is developed to solve Problem RTSP, along with an effective heap implementation strategy. Computational results using real flight generation test cases as well as random simulated problems are presented.     

汽车氙灯测试方法：相关性研究

1 背景 在1989年以前,汽车行业没有一个专门的氙灯加速老化测试方法的国际标准.1989年,汽车工程学会(SAE)发布了J1960"水冷式氙灯汽车外饰件加速暴露测试"和SAE J1885"水冷式氙灯汽车内饰件加速暴露测试"两项汽车材料耐候性测试标准.当时,SAE J1960和J1885有利于汽车制造商统一测试条件.但是,这些老化测试标准基于特定型号的设备构造,指定了某生产商的两种型号设备.     

Conservation and development in Oregon's coastal zone

Abstract

Coastal zone management in Oregon is based on the state's general land‐use law. This body of law is designed to deal with population increase, urbanization, and preservation of agricultural land, as well as with other problems throughout the state. Early planning and policy recommendations for the coast were in the hands of a commission having predominantly local membership. This commission produced an extensive series of studies, policies, and recommendations which were assembled as a proposed management tool for natural resources. Staff of the commission was then absorbed into the state land‐management agency, which developed final goals and guidelines for compliance with the Coastal Zone Management Act. Adoption of the coastal goals in December 1976 has triggered deadlines for local government compliance within the coastal zone. The management program is now undergoing federal review.