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101.
The ability of private conservation organizations to remain financially viable is a key factor influencing their effectiveness. One‐third of financially motivated private‐land conservation areas (PLCAs) surveyed in South Africa are unprofitable, raising questions about landowners’ abilities to effectively adapt their business models to the socioeconomic environment. In any complex system, options for later adaptation can be constrained by starting conditions (path dependence). We tested 3 hypothesized drivers of path dependence in PLCA ecotourism and hunting business models: (H1) the initial size of a PLCA limits the number of mammalian game and thereby predators that can be sustained; (H2) initial investments in infrastructure limit the ability to introduce predators; and (H3) rainfall limits game and predator abundance. We further assessed how managing for financial stability (optimized game stocking) or ecological sustainability (allowing game to fluctuate with environmental conditions) influenced the ability to overcome path dependence. A mechanistic PLCA model based on simple ecological and financial rules was run for different initial conditions and management strategies, simulating landowner options for adapting their business model annually. Despite attempts by simulated landowners to increase profits, adopted business models after 13 years were differentiated by initial land and infrastructural assets, supporting H1 and H2. A conservation organization's initial assets can cause it to become locked into a financially vulnerable business model. In our 50‐year simulation, path dependence was overcome by fewer of the landowners who facilitated natural ecological variability than those who maintained constant hunting rates and predator numbers, but the latter experienced unsustainably high game densities in low rainfall years. Management for natural variability supported long‐term ecological sustainability but not shorter term socioeconomic sustainability for PLCAs. Our findings highlight trade‐offs between ecological and economic sustainability and suggest a role for governmental support of the private conservation industry.  相似文献   
102.
The authors analysed a proportional valve with electrical position feedback for its failure behaviour. Severalfailures were introduced into the feedback loop, especially into the 2 solenoids and the inductive positiontransducer. The behaviour of the valve for square and ramp reference signals was recorded and systematicallyanalysed. It was shown that failures could be detected by monitoring the residual signal from the equipmentunder control or the residual signal from the sensor. It was possible to achieve the safe position within twice thenormal response time of the valve by switching off the current of both solenoids. The application of these resultsfor a new generation of safe proportional valves is discussed. The use of the results of these investigationsobviates the need for redundancy of the electrical position monitoring arrangement in a safe proportionalvalve.  相似文献   
103.
Abstract

Participatory GIS (geographic information systems) is designed to use community mapping exercises to produce spatial representations of local knowledge. The ideals of Participatory GIS revolve around the concept of public participation in the use of spatial data leading to increased community involvement in policy-setting and decision-making (Weiner et al., Community participation and geographic information systems, in: Craig et al., Community participation and geographic information systems, London: Taylor & Francis, 2002). This paper reports on findings from two case studies, one relating to assessments of air quality and how Participatory GIS has been used in the UK to improve local government policy, and the second on assessments of noise pollution. It concludes by discussing a caveat on the use of Participatory GIS for environmental governance, which is that, ideally, only issues on which participants are likely to have direct experiential knowledge should be targeted.  相似文献   
104.
Citizen science initiatives encourage volunteer participants to collect and interpret data and contribute to formal scientific projects. The growth of virtual citizen science (VCS), facilitated through websites and mobile applications since the mid‐2000s, has been driven by a combination of software innovations and mobile technologies, growing scientific data flows without commensurate increases in resources to handle them, and the desire of internet‐connected participants to contribute to collective outputs. However, the increasing availability of internet‐based activities requires individual VCS projects to compete for the attention of volunteers and promote their long‐term retention. We examined program and platform design principles that might allow VCS initiatives to compete more effectively for volunteers, increase productivity of project participants, and retain contributors over time. We surveyed key personnel engaged in managing a sample of VCS projects to identify the principles and practices they pursued for these purposes and led a team in a heuristic evaluation of volunteer engagement, website or application usability, and participant retention. We received 40 completed survey responses (33% response rate) and completed a heuristic evaluation of 20 VCS program sites. The majority of the VCS programs focused on scientific outcomes, whereas the educational and social benefits of program participation, variables that are consistently ranked as important for volunteer engagement and retention, were incidental. Evaluators indicated usability, across most of the VCS program sites, was higher and less variable than the ratings for participant engagement and retention. In the context of growing competition for the attention of internet volunteers, increased attention to the motivations of virtual citizen scientists may help VCS programs sustain the necessary engagement and retention of their volunteers.  相似文献   
105.
We present a framework of resource characteristics critical to the design and assessment of citizen science programs that monitor natural resources. To develop the framework we reviewed 52 citizen science programs that monitored a wide range of resources and provided insights into what resource characteristics are most conducive to developing citizen science programs and how resource characteristics may constrain the use or growth of these programs. We focused on 4 types of resource characteristics: biophysical and geographical, management and monitoring, public awareness and knowledge, and social and cultural characteristics. We applied the framework to 2 programs, the Tucson (U.S.A.) Bird Count and the Maui (U.S.A.) Great Whale Count. We found that resource characteristics such as accessibility, diverse institutional involvement in resource management, and social or cultural importance of the resource affected program endurance and success. However, the relative influence of each characteristic was in turn affected by goals of the citizen science programs. Although the goals of public engagement and education sometimes complimented the goal of collecting reliable data, in many cases trade‐offs must be made between these 2 goals. Program goals and priorities ultimately dictate the design of citizen science programs, but for a program to endure and successfully meet its goals, program managers must consider the diverse ways that the nature of the resource being monitored influences public participation in monitoring.  相似文献   
106.
Abstract: Evidence suggests that the involvement of local people in conservation work increases a project's chances of success. Involving citizen scientists in research, however, raises questions about data quality. As a tool to better assess potential participants for conservation projects, we developed a knowledge gradient, K, along which community members occupy different positions on the basis of their experience with and knowledge of a research subject. This gradient can be used to refine the citizen–science concept and allow researchers to differentiate between community members with expert knowledge and those with little knowledge. We propose that work would benefit from the inclusion of select local experts because it would allow researchers to harness the benefits of local involvement while maintaining or improving data quality. We used a case study from the DeHoop Nature Preserve, South Africa, in which we conducted multiple interviews, identified and employed a local expert animal tracker, evaluated the expert's knowledge, and analyzed the data collected by the expert. The expert animal tracker J.J. created his own sampling design and gathered data on mammals. He patrolled 4653 km in 214 days and recorded 4684 mammals. He worked from a central location, and his patrols formed overlapping loops; however, his data proved neither spatially nor temporally autocorrelated. The distinctive data collected by J.J. are consistent with the notion that involving local experts can produce reliable data. We developed a conceptual model to help identify the appropriate participants for a given project on the basis of research budget, knowledge or skills needed, technical literacy requirements, and scope of the project.  相似文献   
107.
控制论在煤矿安全管理中的应用研究   总被引:1,自引:0,他引:1  
在对近几年我国煤矿死亡事故及安全管理现状分析的基础上,采用安全管理与控制论相结合的方法,提出煤矿安全管理封闭模式,建立煤矿安全管理反馈式信息控制系统模型和煤矿企业安全信息管理系统模型。指出建立并保证信息反馈系统的健全畅通,是我国煤矿安全管理工作的重点。  相似文献   
108.
杜丽冰 《环境技术》1998,16(3):30-34
提出一种三值滤波器输入和权值修正中均采用判决值的非线性判决反馈干扰抑制器,用于抑制CADM中的单频干扰。  相似文献   
109.
《组织行为杂志》2017,38(6):833-855
Drawing on sociometer theory, we argue that when 360 degree feedback is used in a work setting, being ostracized by coworkers has a stronger negative influence on employees' state self‐esteem, which promotes interpersonal deviance and demotivates helping directed toward coworkers, as compared to settings in which 360 feedback is not used. We tested our hypotheses using data collected from North American employees (Study 1) and a two‐wave survey of employees in China (Study 2). Results from both studies support the hypothesized interaction between workplace ostracism and 360 degree feedback on interpersonal deviance and helping behavior. Results from Study 2 further show that lower state self‐esteem accounts for the stronger negative association of ostracism with helping behavior among employees who are exposed to 360 degree feedback. Ostracism is not related to subsequent state self‐esteem or behavior when 360 degree feedback is absent. We discuss the implications for theory and research concerning employee exclusion. Copyright © 2016 John Wiley & Sons, Ltd.  相似文献   
110.
高水分蔬菜和花卉废物序批式进料联合堆肥的中试   总被引:8,自引:3,他引:5  
以滇池流域典型蔬菜废物(西芹、白菜)和花卉废物(石竹)为原料,进行了序批式联合堆肥的试验研究.以西芹和石竹作为初始物料,控制初始混合物料的含水率在60%~70%,每隔4d添加一次白菜;采用温度反馈通气量控制的好氧静态堆肥技术,在堆体温度40℃左右时停止通风.试验分析了堆肥过程中堆体温度、通风速率、水分、pH值、有机质、灰分、体积、NH4+-N,NO3--N等指标随时间的变化特征.结果表明:采用序批式进料、温度反馈通气量控制的静态好氧堆肥技术进行蔬菜和花卉废物联合堆肥可以有效控制堆肥过程,实现有机物料的快速稳定和去除水分,解决了滇池流域蔬菜废物量远大于花卉废物量时堆肥难以有效进行的技术难题.  相似文献   
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