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Hydrogen is starting to be mentioned as an alternative fuel to replace the fossil fuel in future transportation applica- tions due to its characteristics of zero greenhouse gas emission and high energy efficiency. Before hydrogen fuel and its facilities can be introduced to the public, relevant safety issues and its hazards must be assessed in order to avoid any chance of injury or loss. While a traditional risk assessment has difficulty in prioritizing the risk of failure modes, this paper proposes a new fuzzy-based risk evaluation technique which uses fuzzy value to prioritize the risk of various scenarios. In this study, the final risk of each failure modes was prioritized by using the MATLAB fuzzy logic tool box with a combination of two assessments. The first assessment was concerned with the criteria which affected the actual probability of occurrence. This assessment considered the availability of the standard that was applied to prevent the likelihood of the scenario occurring. On the other hand, the second assessment was focused on evaluating the consequence of the failure by taking into account the availability of detection and the complexity of the failure rather than only the severity of the scenarios. A total of 87 failure scenarios were identified using failure modes and effect analysis （FMEA） procedures on hydrogen refueling station models. Fuzzy-based assessments were performed through risk prioritizing various failure scenarios with a fuzzy value （0 to 1） and risk level （low, medium, and high） while a tra- ditional risk assessment approach presented the risks only in forms of level （low, medium, and/or high）. Availability of the fuzzy value enabled further prioritizing on the risk results that fell in the same level of risk. This study concluded that fuzzy-based risk evaluation is able to further prioritize the decisions when compared with a traditional risk assessment method. 相似文献
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陕西牛背梁自然保护区主要保护国家Ⅰ级保护动物羚牛及其栖息地。保护区位于秦岭东段主梁上的狭长区域,四周被县辖国营林场、集体林、自留山包围,近年来由于对该区域无序与过度地旅游开发,对保护区主要功能的负面影响越来越明显,不断增加的森林公园、避暑山庄、自助游线路、商业活动摊点等,使得自然保护区出现＂孤岛效应＂、生物多样性和野生动植物栖息地受到干扰和破坏、环境被污染、管理难度增加、资源开发利用和保护矛盾突出,针对这些问题,本文提出了加强对旅游项目的科学审批、加强对旅游活动的监督管理、加强对游客的宣传教育力度、引导游客文明旅游等相应的管理对策与措施。 相似文献
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目前秦岭地区森林病虫害防治工作形势严峻,仍存在一系列亟待解决的问题。本文就森林病虫害工作进行了探讨,并提出了相应的管理措施与对策。 相似文献
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Solar energy is a natural resource which can be harnessed to provide clean electricity for hydrogen production systems. However, this technology is not widely used because of control issues, particularly for hydrogen refuelling stations. At present, direct or DC-DC converter couplings are the most common system configurations for hydrogen refuelling stations. However, these system configurations are costly and suffer from gas shortage at hydrogen refuelling stations. Furthermore, the hydrogen produced by such system configurations varies considerably depending on the levels of solar radiation. In order to address these issues, a new system configuration is proposed, incorporating the feedback signal of the storage level in the control system. The photo- voltaic （PV） system, electrolyzer, and storage tank are integrated with a fuzzy logic controller （FLC） to determine the backup current compensation for electrolyzer operation in order to obtain the minimum power required for hydrogen production. The proposed FLC is constructed with three input variables which are the PV current, hydrogen storage level, and the battery state of charge. The rules-based fuzzy inference process is based on the proposed configuration which combines the advantages of direct and DC-DC converter coupling configurations. The simulation results show that the proposed configuration offers better adapta- bility to variable radiation conditions compared to other methods. This gives a more promising option for ensuring the adequacy of hydrogen supply at hydrogen refuelling stations. 相似文献
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关于自然保护区管理工作的探讨 总被引：1，自引：0，他引：1
在中国自然保护区建设与发展进程中,目前面临的首要问题不是保护区数量不足的问题,而是对现有保护区如何进行有效管理的问题。本文在对我国自然保护区建设成就、管理现状与存在问题描述的基础上,从如何充分发挥科技支撑作用的角度就自然保护区的管理工作进行了探讨,并提出了建议与对策。 相似文献
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