五边到场交通态势安全评估研究

为提高五边到场交通运行的安全性,基于客观、合理的评估五边到场交通态势的重要性,探讨空中交通复杂性在五边到场交通态势评估中的应用,并利用基于五边到场交通的复杂性图示方法,画出五边到场交通复杂性图,通过对复杂性图的分析来描述当前五边到场交通态势的安全特征,包括航空器与航空器之间发生冲突的可能性以及到场航空器允许插入五边的时间和位置等。结果表明:五边到场交通复杂性图能客观、准确地评估五边到场交通中航空器与航空器之间潜在的冲突大小,通过五边到场交通复杂性来对五边到场交通态势进行安全性评估是可行的。     

A Systems Based Framework to Examine The Multi-contextural Application of the Sustainability Concept

A conceptual framework is generated through systems principles to explain sustainability’s wide diversity of interpretation and contextual application. Sustainability is reduced to a literal interpretation as the ability to sustain, and then expressed in simple systems as the ability of one system to sustain another system over time. This reinforces the importance of time in the sustainability debate, and suggests the concept can be legitimately applied to timeframes that have absolute limits. The framework is expanded to complex systems as the changing ability of one or many systems to sustain the changing requirements of one or many systems, over time. This accommodates multiple relations and system dynamics, and hints at the extraordinary complexity encompassed by the sustainability concept. Practical implications relate to the evolving meaning of sustainability, the need for continual change to remain sustainable, and that the sustainability concept can be validly applied to virtually any context or situation that exhibits a dimension of continuity. Derived criteria useful for clarifying contextual applications of sustainability include stating the how, what, why, who and for how long of sustainability, along with indicating the most appropriate hierarchical tier at which the concept is being applied.     

Set-aside management: How do succession, sowing patterns and landscape context affect biodiversity?

European Union (EU) member states set aside between 5 and 15% of arable land during the last two decades, but abolition of the set-aside scheme in 2008 caused a sudden loss in habitat availability and biodiversity in agricultural landscapes. Management of set-aside has many facets and in this perspective paper we focus on the biodiversity effects of successional age, sowing strategies and landscape context. Young, 1-2-year-old set-asides have been initially considered to be too ephemeral to have any conservation value. However, when a rich seed and bud bank is available, a species-rich natural (secondary) succession can be observed. Arable (annual) weed communities in the first two years of succession can even include endangered plant species with associated rare insect consumers. Furthermore, many bird species benefit from early-successional habitats, whereas small mammal communities are richer in older habitats. If the local plant species pool is poor, sowings of diverse mixtures from regional seed collections can be recommended. Set-aside managers using species-rich sowings often experience that dominant weeds suppress the less competitive annual species. This trend to species-poor communities can be avoided by intraspecific aggregation of competitively weak species. Broadening the spatial scale from the plot to the landscape, efficiency of set-aside is highest in simple landscapes, where set-aside exhibits greatest effect in enhancement of biodiversity and associated services such as pollination and biological control. In complex landscapes, however, additional set-aside does not add much to the high level of biodiversity and ecological processes already present. Twenty percent of semi-natural, non-crop habitat appears to be a rough threshold for enhancing biodiversity and sustaining services such as pollination and biological control, but improved set-aside management should have the potential to reduce the percentage of semi-natural non-crop habitat needed. EU policy should tailor set-aside schemes for the maintenance of biodiversity and also consider that management efficiency is higher in simple than complex landscapes.     

GRNN模型在煤与瓦斯突出及瓦斯含量预测中的应用

煤与瓦斯突出的作用机理非常复杂,是诸多因素如地应力、煤层瓦斯、煤体物理力学性质等共同作用的结果。在分析广义回归神经网络(GRNN)的基本原理和算法的基础上,建立煤与瓦斯突出等级以及基于构造复杂程度定量评价的瓦斯含量GRNN模型。然后用收集到的工程实例样本训练和检验该模型。结果表明,GRNN模型具有很好的预测能力和泛化能力,能较好揭示瓦斯含量和诸影响因素间的关系,可用于煤与瓦斯突出判别以及瓦斯含量预测。同时可以看出,光滑因子的合理选取对于提高GRNN模型的预测精度非常重要,因此,在以后的实际应用中需要不断尝试,找出最合理的光滑因子。     

Towards a complex model of disaster behaviour

This paper outlines why a move towards a complex adaptive systems model of behaviour is required if the goal is to generate better understanding of how individuals and groups interact with their environment in a disaster setting. To accomplish this objective, a bridge must be built between the broader social sciences and behavioural economics to incorporate discipline‐specific insights that are needed to move towards complexity. This is only possible through a deeper understanding of behaviour and how the environment in which they occur can influence actions. It is then that one can counteract the poor behavioural predictions, flawed policies based on myth, inefficient design, and suboptimal outcomes that have flourished in the absence of a complex adaptive systems model. This paper provides a conceptual framework that draws on concepts from across the natural and social sciences, such as behavioural economics, endocrinology, psychology, sociobiology, and sociology in order to build an interactive theory of disaster behaviour.     

Coordination in theory,coordination in practice: the case of the Clusters

The atomised nature of the humanitarian system has led to frequent and repeated attempts to coordinate humanitarian activity. Since 2005, some of the best resourced, and arguably most successful, coordination mechanisms have been the humanitarian Clusters, groups of UN (United Nations) and non‐UN actors that engage in sectoral coordination of humanitarian response (such as the provision of healthcare and water) at the global and country level. Nevertheless, it is not clear exactly what ‘coordination’ means in the context of a Cluster. Formal guidance suggests that they should be aiming to create a single, joint strategy to guide the activities of members. Actual experience of the Clusters, however, indicates that looser forms of coordination are more effective. This finding resonates with organisational theory, and with the experience of emergency management professionals beyond the international humanitarian sector. To capitalise fully on the success of the Clusters, policymakers may need to rethink their attitudes to, and expectations of, coordination.     

Reframing the concept of alternative livelihoods

Alternative livelihood project (ALP) is a widely used term for interventions that aim to reduce the prevalence of activities deemed to be environmentally damaging by substituting them with lower impact livelihood activities that provide at least equivalent benefits. ALPs are widely implemented in conservation, but in 2012, an International Union for Conservation of Nature resolution called for a critical review of such projects based on concern that their effectiveness was unproven. We focused on the conceptual design of ALPs by considering their underlying assumptions. We placed ALPs within a broad category of livelihood‐focused interventions to better understand their role in conservation and their intended impacts. We dissected 3 flawed assumptions about ALPs based on the notions of substitution, the homogenous community, and impact scalability. Interventions based on flawed assumptions about people's needs, aspirations, and the factors that influence livelihood choice are unlikely to achieve conservation objectives. We therefore recommend use of a sustainable livelihoods approach to understand the role and function of environmentally damaging behaviors within livelihood strategies; differentiate between households in a community that have the greatest environmental impact and those most vulnerable to resource access restrictions to improve intervention targeting; and learn more about the social–ecological system within which household livelihood strategies are embedded. Rather than using livelihood‐focused interventions as a direct behavior‐change tool, it may be more appropriate to focus on either enhancing the existing livelihood strategies of those most vulnerable to conservation‐imposed resource access restrictions or on use of livelihood‐focused interventions that establish a clear link to conservation as a means of building good community relations. However, we recommend that the term ALP be replaced by the broader term livelihood‐focused intervention. This avoids the implicit assumption that alternatives can fully substitute for natural resource‐based livelihood activities.     

Humanitarian (in)security: risk management in complex settings

Attacks against humanitarian aid workers have received increasing attention in the media, particularly high-profile incidents such as those against the hospitals of Médecins Sans Frontières in Afghanistan, Syria, and Yemen. Concurrently, scholarly research has given rise to a number of articles, white papers, and books on humanitarian insecurity. Most of this work centres on external threats, neglecting the internal mechanisms that humanitarian organisations use to mitigate security situations. This paper builds on the existing literature by focusing on the decision-making processes of humanitarian organisations, drawing on data collected from 16 security managers or advisers. The findings reveal that several factors contribute to contextual uncertainty and complexity, including recipient perceptions, local government actions, the behaviour of other non-governmental organisations (NGOs) in the area, logistical issues, risk variance within a single location, and organisational mandate. Furthermore, the results indicate that NGOs utilise a combination of decision-making processes to determine how to manage security in high-risk environments.     

基于农业用地和地形约束的陇南山区适宜人口规模估算

陇南山区地形复杂,耕地不足,经济贫困,人口对资源环境的压力较大。研究适度人口容量对于地震灾后重建、缓解贫困以及保护长江上游的生态安全具有重要意义。以人均粮食和经济水平两个指标来估算温饱、宽裕和小康3个水平上的人口承载量,测度人口和农业资源的关系。并基于地形复杂度计算劳动用工及可抚养人口。结果表明:目前陇南10县(区)的人口在温饱生活水平下尚有超载。以小康生活为标准,适宜人口规模约为135万。经营现有的农耕地和林地需要100.81万劳动力,可抚养人口191.54万人,加上城镇人口总人口为231.03万。这个人口规模实现温饱有余而宽裕不足,难达小康目标。"人口-农业用地-劳动力"之间形成了一个怪圈,决定了陇南山区农村实现小康目标的艰巨性和复杂性。为此,陇南山区的灾后重建和区域可持续发展需要创新思路,多方并举。     

Ecological Trap for Desert Lizards Caused by Anthropogenic Changes in Habitat Structure that Favor Predator Activity

Abstract: Anthropogenic habitat perturbation is a major cause of population decline. A standard practice managers use to protect populations is to leave portions of natural habitat intact. We describe a case study in which, despite the use of this practice, the critically endangered lizard Acanthodactylus beershebensis was locally extirpated from both manipulated and natural patches within a mosaic landscape of an afforestation project. We hypothesized that increased structural complexity in planted patches favors avian predator activity and makes these patches less suitable for lizards due to a heightened risk of predation. Spatial rarity of natural perches (e.g., trees) in arid scrublands may hinder the ability of desert lizards to associate perches with low‐quality habitat, turning planted patches into ecological traps for such species. We erected artificial trees in a structurally simple arid habitat (similar to the way trees were planted in the afforestation project) and compared lizard population dynamics in plots with these structures and without. Survival of lizards in the plots with artificial trees was lower than survival in plots without artificial trees. Hatchlings dispersed into plots with artificial trees in a manner that indicated they perceived the quality of these plots as similar to the surrounding, unmanipulated landscape. Our results showed that local anthropogenic changes in habitat structure that seem relatively harmless may have a considerable negative effect beyond the immediate area of the perturbation because the disturbed habitat may become an ecological trap.