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《中国海洋大学学报(自然科学版)》2017,(7)
利用滑模控制方法研究了一类分数阶参数不确定混沌系统的自适应同步控制问题,基于Lyapunov稳定性理论和分数阶微积分的相关理论,给出分数阶参数不确定系统取得滑模同步的充分性条件,并给出了严格的证明,研究表明,一定条件下分数阶不确定系统是滑模混沌同步的,仿真结果表明了方法的可行性。 相似文献
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不规则海洋重磁测网的调差 总被引：2，自引：0，他引：2
不规则测网是海洋重磁调查中的重要情况之一。本文建立了利用测网中实交点处交点差的资料确定各测线资料中含有的系统偏差的方程组，证明了此方程组有无穷多组数学解，但通解公式中仅含有一个任意常数，因而需要也只需要引进一个附加的控制条件就能有确定的解；还确定了线性控制条件应满足的数学条件，并依F取极小值的原则推导出一个可用的线性控制条件，从而为不规则测网的线调差提供一条途径。 相似文献
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设计了一种新的合成路线。采取先加成后消除的两步法,使产率大幅度提高,总产率达90％,并经过条件实验,确定了最佳反应条件,选择了较理想的后处理方法,使制备工艺简单易行。 相似文献
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不规则海洋重磁测网的调差 总被引：1，自引：0，他引：1
不规则测网是海洋重磁调查中的重要情况之一。本文建立了利用测网中实交点处交点差的资料确定各测线资料中含有的系统偏差的方程组，证明了此方程组有无穷多组数学解，但通解公式中仅含有一个任意常数，因而需要也只需要引进一个附国听控制条件就能有确定的解；还确定了线性控制条件应满足的数学条件，并以极小值的原则推出一个可用的线性控制条件，从而为不规则测网的线调差提供一条途径。 相似文献
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基于RS与GIS技术的地质灾害危险性评价——以青岛市崂山区为例 总被引：1，自引：0，他引：1
以SPOT5遥感影像为主要数据源,利用GIS空间分析功能,结合遥感技术,用层次分析法确定权重,采用加权综合分析法建立了青岛市崂山区地质灾害危险性综合评价模型,从地形地貌条件、地质条件、气候植被条件、水文条件、人为活动与历史灾害情况等方面,选取9个评价因子,对崂山地区地质灾害危险性进行了定量评价,并绘制了崂山区地质灾害危险性评价分区图。评价结果与实际基本相符合。 相似文献
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针对网络控制系统中存在的不确定时滞,将网络控制系统模型转化为不确定系数的离散时间模型。利用Lya-punov稳定性理论和线性矩阵不等式技术,提出动态输出鲁棒控制器的设计方法,同时给出闭环系统鲁棒渐近稳定的充分条件。仿真例子验证了所提方法的有效性。 相似文献
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《中国海洋大学学报(自然科学版)》2015,(7)
利用响应面方法优化并确定了鼠尾藻幼苗生长的最佳生态因子组合条件。采用单因子实验方法,分别测定在不同温度、光照强度和盐度条件下鼠尾藻幼苗的特定生长率,结果发现,温度、光照强度和盐度分别为18℃、8 000lx和28时,其特定生长率最大。以单因子实验结果进行估算,确定了温度、光照强度和盐度的水平范围,根据Box-Behnken中心组合设计,采用多因子实验方法进一步测定了鼠尾藻幼苗特定生长率。利用响应面法对中心组合实验数据进行分析,结合验证实验,确定了鼠尾藻幼苗生长的最佳生态因子组合条件为温度17.74℃、光照强度7 449.27lx、盐度29.08,在该条件下鼠尾藻幼苗特定生长率为6.28%,高于单因子实验和Box-Behnken中心组合设计试验中测定的鼠尾藻幼苗特定生长率。研究表明,响应面法优化鼠尾藻幼苗生长的生态因子组合条件,可用于指导鼠尾藻幼苗早期培育,同时为鼠尾藻生态学、养殖学和鼠尾藻规模化繁育提供理论依据。 相似文献
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山东飞机人工增雨效益估算系统 总被引：3，自引：0，他引：3
王以琳 《中国海洋大学学报(自然科学版)》2000,30(3):390-396
在山东飞机人工增雨效益估算系统中 ,根据冷云催化剂扩散模式 ,以作业区内碘化银粒子扩散的浓度为依据 ,确定飞机人工增雨的影响区 ;以天气系统历史降雨量的分布等条件确定对比区 ;采用单次天气系统分层历史回归或区域对比的统计方法确定增雨量。该系统在较客观地选择对比区和影响区的问题上有较大的改进。程序操作简单 ,实现了业务化。 相似文献
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用变维分形确定海岸线长度 总被引：5，自引：0，他引：5
应用变维分形来确定海岸线的长度。根据ｒ－０时Ｄ－１的条件，及不同ｒ值时的测定结果，确定了海南岛北部一般海岸线是有限长的，而非无限长的。本文还引入长度比尺来确定海岩线的复杂程度，Ｒ值越大的海岸线越复杂。 相似文献
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Elodie J.I. LédéeStephen G. Sutton Renae C. TobinDebora M. De Freitas 《Marine Policy》2012,36(1):226-234
Fishers' responses to changes in resource access through the imposition of marine protected areas can be a critical factor influencing the likelihood of achieving management objectives.Face-to-face interviews with 114 commercial and charter fishers were conducted to investigate their responses and adaptation strategies to the increase in the size and number of no-take zones imposed by the 2004 Great Barrier Reef Marine Park zoning plan. Despite holding positive attitudes towards marine biodiversity protection, fishers were generally unsupportive of the new zoning plan 5 years after its implementation. Fishers' lack of support was related to the perception that they had not been adequately engaged in the rezoning process and the perception of significant impacts of the zoning plan on fishing businesses. Fishers generally believed that the new zoning plan had a negative impact on their access to productive fishing areas, the numbers of fish they catch, the profitability of their fishing business, and their personal income. In response to the new no-take zones, fishers tended to redistribute their fishing activity to locations closer to their home port, and to locations already known to them through their previous fishing, resulting in an increase in high density fishing locations within the park. Despite the impacts that fishers experienced, most reported that they have adapted their fishing activity and fishing business at least moderately well to the new zoning plan, suggesting that many of the impacts experienced by fishers might be short-term and may decline over time as fishers learn to adapt to the new zoning system. The information provided should prove valuable as a baseline for continued monitoring of the costs and benefits of the Great Barrier Reef Marine Park rezoning into the future. 相似文献
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A White Paper on a new integrated management plan for the Norwegian Sea was launched by the Norwegian government in May 2009. Following international guidelines for ecosystem-based management, the plan provides an overall framework for managing all human activities (mainly oil and gas industry, fishing, and shipping) in the area to ensure the continued production and function of the ecosystem. The plan is based on an assessment of the present and projected future impact of human activities and of the interactions between them, taking into account deficits in current knowledge of ecosystem state and dynamics. Areas of particular value in terms of biodiversity or biological production were identified. In each of these valuable areas, any access for substantial human activity is to be carefully managed. To monitor the overall development of the Norwegian Sea, a set of indicators with associated environmental quality objectives have been selected. The approach used builds upon experience gained from the first integrated Norwegian management plan for a marine area, the Barents Sea–Lofoten region, developed in 2002–2006. Work towards a Norwegian management plan for the North Sea, including Skagerrak, was initiated in 2009. 相似文献
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The Sea Prince accident was the first VLCC accident in Korea and a shock to the general public and government. Before the accident, any oil-spill management plan, such as National contingency plan (NCP) and regional contingency plans (RCPs), was not available and the resources for oil spills were lacking for the Sea Prince accident. About 5000 tons of oil spilled, polluting large areas of southern coastal waters, damaging the fisheries, including aquaculture. After the Sea Prince accident, Korea's government established various alternatives for dealing with oil spills, such as the NCP, RCPs, Typhoon Refuge Management Plan, and resources for oil-spill response. However, port safety management in emergency situations such as typhoons has not been solved. 相似文献
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The concept of equilibrium plan form and equilibrium profile has been widely used as an engineering tool in order to design beach nourishment projects. The scope of this paper is to further explore this “equilibrium beach” concept in crenulated bays, as a long-term tool for beach nourishment projects. The proposed methodology is based on González and Medina (2001) and combines the static equilibrium plan and profile for long-term analysis. This methodology includes a modified equilibrium plan form, which is able to define the orientation of the local wave front in the diffracting point, and also to locate the downcoast starting point of the static equilibrium beach from which the parabolic plan form of Hsu and Evans (1989) is valid. This methodology permits the application of any equilibrium profile formulation. An example of the application of this methodology and long-term formulations to the design of the Spanish nourishment project of Poniente Beach (Gijón) is presented. Ten years after its construction, the beach has still got a static equilibrium and remains pretty close to the predicted equilibrium beach in plan and profile. 相似文献
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Nikuradse roughness (ks) is very important in the sediment transport prediction because it is related to the evaluations of the velocity distribution, shear stress and erosion depth. Dimensionless Nikuradse roughness (ks/D, where D is the sediment diameter) is usually given 1–2.5 on the immobile plan bed or at low shear stress. But it behaves differently on the mobile plan bed at high shear stress with much sediment picked up to movement when the Shields parameter (Θ) is larger than 0.8–1.0. The effective Nikuradse roughness on the mobile plan bed was derived indirectly from the erosion depth correlated to the mobile plan bed thickness considering the mass conservation in the present study. The proposed erosion depth confirmed the relation to the Shields parameters with an extra factor consisting of suspended sediment and its damping to turbulence. The decrement of the erosion depth caused by the increment of the sediment diameter at large shear stress was obtained, which was usually absent in classical empirical formulas based on the bedload theory. Good agreement with experiments was achieved by the present prediction of the Nikuradse roughness, erosion depth and sediment transport rate. Discussion was mainly focused on the prediction improvement caused by considering the impact of suspended sediment and its damping to turbulence. 相似文献
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《Marine Policy》2017
The herring stock in the Celtic Sea collapsed in 2004. The stock is managed under the European Union's (EU) Common Fisheries Policy (CFP), but with a large measure of local stakeholder involvement through the Pelagic Advisory Council and a local Irish stakeholder committee. An iterative process, initiated by the local committee culminated in a formal rebuilding plan, which ran until 2012, by which time, the stock had fully recovered. Subsequent analyses of stock development over this period suggest that the stock was already recovering by the time the final plan was implemented. Did the stock rebuild by good fortune or did the governance measures put in place achieve their aims? This question is answered by way of examination of stock trends over time, analyses of the main elements of the rebuilding measures, including a management strategy evaluation (MSE) along with analyses of the legal and institutional arrangements in Ireland and in the EU CFP, including the development of the Pelagic Advisory Council. Important innovations in the CFP are revealed as having been crucial for the rebuilding process. 相似文献
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《Ocean & Coastal Management》1999,42(1):39-47
Successful coastal zone management (CZM) requires the participation of five sectors: local people, government authorities, non-governmental organizations (NGOs), scientists and investors. NGOs must play an important role in providing the opportunities for all sectors to meet and talk with each other. All the parties involved should have the chance to express and exchange their opinions. They should be able to discuss the problems they are facing and how they would like them to be solved. When all needs and problems have been discussed scientists or academics could then provide their expertise in formulating the CZM plan. The plan should reflect all the needs each sector has expressed as well as mitigation measures for implementation. Such- a co-management process should result in a satisfactory and sustainable CZM plan. This plan should be monitored and revised whenever it is seen fit. This is the pattern that Thailand is experiencing. 相似文献
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《Marine Policy》2014
Korea's coastal and offshore fisheries have experienced reduction in their catch in the early 2000. The amount of catch from coastal and offshore fisheries dropped from 1.7 million tons in 1986 to 1 million tons in 2004. To address such catch reduction, fish stock enhancement programs have been constantly developed and implemented. However, as fish stocks have been estimated to decrease since 2000 in spite of various management measures, the Korean Government genuinely acknowledges the necessity to enhance fisheries productivity through the recovery of depleted fish stocks. Based on such acknowledgement, a fish stock rebuilding plan (FSRP) combined with conventional fish stock enhancement programs was established in 2005. For stocks which have shown drastic decrease, a FSRP was set up and promoted. So far, 10 FSRPs have been established and operated, and plan is being made to expand them to 20 species by 2012. The result of pilot projects shows that stocks have been increasing after the introduction of FSRPs. For instance, the catch per unit effort (CPUE) of sandfish in the East Sea has increased from 0.44 in 2005 to 0.78 in 2011. Consequently, fishing income has increased by 15%. The key lessons learned during the implementation of FSRP are: the causes for the decrease of stock vary and are complicated and it is necessary to adjust and eliminate some conventional policies that could have unforeseen negative impacts on fish stocks. The FSRP-based fisheries management policy in Korea carries great significance, for it has changed the focus of policy from simply maintaining the status quo to stock recovery and it allows relevant stakeholders to get actively involved in the procedures of establishing and promoting the plan, leading to effective implementation of the plan. The current FSRP is operated with species, but if it can be gradually expanded to encompass the whole ecosystem, it will greatly contribute to more effective management and fish stock recovery for all species in offshore and coastal waters surrounding Korea. 相似文献