QoS-Aware Power Allocation Scheme for Relay Satellite Networks

This paper investigated a QoS-aware power allocation for relay satellite networks. For the given QoS requirements, we analyzed the signal model of relay transmission and formulated the power minimization problem which is non-convex and difficult to solve. To find the optimal solution to the considered problem, we first analyzed the optimization problem and equivalently turn it into a convex optimization problem. Then, we provided a Lagrangian dual-based method to obtain the closed-form of the power allocation and provided an iterative algorithm to the optimal solution.Moreover, we also extended the results to the cooperative transmission mode. Finally, simulation results were provided to verify the superiority of the proposed algorithm.     

SRS: Spatial-tagged radio-mapping system combining LiDAR and mobile-phone data for indoor location-based services

One of the most challenging issues in radio received signal strength (RSS)-based localization systems is the generation and distribution of a radio map with a coordinate system linked with spatial information in a large indoor space. This study proposes a novel spatial-tagged radio-mapping system (SRS) that effectively combines the heterogeneous properties of LiDAR and mobile phones to simultaneously perform both spatial and radio mappings. The SRS consists of synchronization, localization, and map building processes, and enables real-time spatial and radio mapping. In the synchronization process, the distance range, motion data, and radio signals obtained through the LiDAR and mobile phone are collected in nodal units according to the sensing time. In the localization process, a feature variance filter is used to control the number of features generated from LiDAR and estimate the positions at which the nodes are generated in real time according to the motion data and radio signals. In map building, the estimated positions of the nodes are used to extract spatial and radio maps by using a unified location coordinate system. To ensure mobility, the SRS is manufactured in the form of a backpack supporting LiDAR and a mobile phone; the usefulness of the system is experimentally verified. The experiments are performed in a large indoor shopping mall with a complex structure. The experimental results demonstrated that a common coordinate system could be used to build spatial and radio maps with high accuracy and efficiency in real time. In addition, the field applicability of the SRS to location-based services is experimentally verified by applying the constructed radio map to well-known fingerprinting algorithms using the heterogeneous mobile phones.     

多中心治理视角下经济与生态共赢的路径与启示

改革开放40年来,我国经济飞速发展的同时也产生了一系列的生态环境问题,土壤重金属污染问题尤为严重。上世纪80年代,江西贵溪地区数家大中型冶炼、化工类企业在九牛岗区域逐渐集中,由于长期对资源的粗放型开发,高耗能、高污染、高排放加之低效率生产对贵溪J区域农田造成了严重污染,土壤重金属含量严重超标,生态环境遭到破坏。污染治理过程中,各相关主体从“各自为政”到“共同发力”,从长期得不到有效解决到多主体相互协作综合治理取得成效,走出了一条政府主导,企业主体,村民参与,社会支持的土壤重金属污染治理新路。本文着重就自然资源、环境保护与社会经济如何协调发展,探索运用多中心治理理论对土壤污染治理进行实践,推动经济发展与生态环境和谐共进。     

To outsource or not: The impact of information leakage risk on information security strategy

Emerging studies advocate that firms shall completely outsource their information security for cost and technical advantages. However, the risk of information leakage in outsourcing to managed security service providers (MSSPs) is overlooked and poses a confidentiality threat. We develop analytical models to describe several strategies for firms to consider when they decide to outsource to MSSPs. Based on our results, we suggest partial outsourcing as an alternative strategy when the firm faces information leakage risk. Besides, we suggest that in-house information security strategy is the optimal solution when the risk of being attacked is low regardless of the risk of information leakage. We then extend scenarios to the competitive environment where firms that are in the same market are highly likely to choose the same strategy.     

基于QFD的社区老年人慢性病管理产品服务系统设计研究

以老年慢性病患者为研究对象,以提高社区居家养老模式下的老年慢性病管理水平为研究目标,以提供社区卫生机构慢性病管理产品服务方案为实践目标。在数据收集和分析阶段,采用定性研究的方法收集用户数据,通过构建典型人物模型总结现有问题;通过分解典型场景中的用户需求,得出对应的具体服务需求和服务内容;并以KANO模型的结果为依据,划分服务需求的类型。在服务模型构建阶段,以QFD方法及相关理论为指导,构建质量屋,输出用户需求对应的服务特性重要度排序,并依照设计原则评估。构建基于不同类型用户需求的质量屋,得出慢性病管理有关的服务特性在社区场景下的重要度排序,并提出面向社区老年人的慢性病管理产品服务系统设计策略。     

油气开采用钛合金石油管材料耐腐蚀性能研究

选取5种油气开发常用钛合金材料(Ti-6Al-4V、Ti-6Al-4V-0.1Ru、Ti-6Al-2Sn-4Zr-6Mo、Ti-3Al-8V-6Cr-4Zr-4Mo和Ti-5.5Al-4.5V-2Zr-1Mo)为研究对象,使用高温高压釜模拟国内典型严酷服役工况环境,研究了不同钛合金材料耐均匀腐蚀、局部腐蚀、点蚀、应力腐蚀开裂(SCC)及缝隙腐蚀的性能,通过使用扫描电镜和能谱分析等手段对腐蚀形貌和腐蚀产物进行了分析,并使用电化学方法对不同合金的耐腐蚀机理进行了研究。结果显示,在所测试工况条件下,所有钛合金材料腐蚀反应均为阳极控制过程,均匀腐蚀速率均低于0.001mm/a,并且对应力腐蚀开裂均有良好的抗力。Ti-6Al-4V和Ti-5.5Al-4.5V-2Zr-1Mo合金出现明显的点蚀和缝隙腐蚀问题。对腐蚀机理研究表明,在工况条件温度下,随着pH值的降低,所有钛合金均发生自腐蚀电位降低,极化电阻减小,腐蚀电流增大,耐腐蚀性能下降,其中Ti-6Al-4V耐腐蚀性能下降的最为明显,研究结果为油气开发工况下钛合金石油管的选材和缝隙腐蚀问题防治提供理论基础。     

“We are All Refugees”: Camps and Informal Settlements as Converging Spaces of Global Displacements

ABSTRACT

This paper is in conversation with two important bodies of literature: one on informal settlements (informal and insurgent grassroots practices) and another on camps (spatial practices and governance of refugees). Reading inhabitants’ experiences in Korail, an informal settlement in Dhaka, Bangladesh, through the literature grounded in the experiences of refugees, we seek to contribute to the relational theorization of informal settlements and camps as an expanding and overlapping reality in the era of intensified global displacements. Weaving back and forth between the camp literature and Korail’s reality, we bring to light the comparable spatial practices and governance of the so-called citizens and the so-called stateless. We present the insights we gain from this analytical conversation under three organizing themes: experiential to highlight the precarious relationship of the two groups to citizenship and place, what we call a state of “citizenship in wait” and “in-situ displacement”; institutional to highlight the humanitarian matrices of care that provide governmental structures in both contexts; and micropolitical, to characterize dwellers’ contestations with state and humanitarian governance that constitute the processes of life-making in informal settlements, much as in the camps. Conceptually the paper lends a forceful voice to the mounting critiques of the state-centered canon in planning theories and the needed Southern turn in planning theorization. Politically, it lends a hand to the efforts of activists working to overcome exclusions and erasures that are endemic to the politics of citizenship, that pit refugees against the poor, and to gesture toward forging solidarities for a humane urbanism.     

江淮丘陵区马槽河流域污染源调查分析及治理建议

随着区域城市人口增加和人民生活水平提高，江淮丘陵区中小河流水环境污染问题日益突出，成为区域社会经济发展的主要制约因素之一。本文以位于江淮丘陵区马槽河流域为研究对象，通过资料收集、问卷调查、实地勘察等手段，查明该地区入河污染物指标 COD、氨氮、TN、TP 主要贡献因素及占比，其中生活污染（51%，40%，54%，28%）、面源污染(6%，38%，9%，42%)、畜禽养殖（39%，15%，17%，25%）三类型贡献占比 90%以上，内源污染和水产养殖较少。针对污染源调查结果特征，提出镇区管网完善、农村分散处理、畜禽粪污处理、养殖废水农田消纳、污染缓冲带设置、径流拦截与再利用、河流生态化改造等治理建议，可为今后中小河流污染源调查与治理提供借鉴。     

Current condition and future directions for lean construction in highways projects: A small and medium-sized enterprises (SMEs) perspective

The aim of this study is to identify the parameters defining how Lean Construction (LC) is being implemented (current condition) and how LC can be further promoted (future direction) from a Small-Medium Sized Enterprises (SMEs) perspective. Although SMEs constitute the largest group in construction supply chains, LC, as an emerging phenomenon in civil construction project management, has been rarely investigated from an SMEs perspective. Also, overlooking the more macro factors like project governance and supply chain management, LC deployments have been mainly discussed from a production process perspective to date. After a review of the extant literature and 20 interviews with managers from the highways sector, a list of 31 current condition and 40 future direction statements were produced, classified under the delivery, process, training, project governance and supply chain related headings and used in a questionnaire survey with 110 responses. The current condition highlights problems like a short-term relations structure, competitive tendering mechanisms, fragmentation, problems in engaging with SMEs for LC, unstandardised LC techniques, and issues with convincing SMEs to deploy LC by demonstrating the business case on mutual benefits. Action items relating to the current project delivery structure were given the highest importance by the supply chain, alongside the LC training and project governance issues for the future of LC at highways SMEs. Additionally, a statistically significant correlation was identified among many future action items.     

SLA-driven container consolidation with usage prediction for green cloud computing

Since service level agreement(SLA)is essentially used to maintain reliable quality of service between cloud providers and clients in cloud environment,there has been a growing effort in reducing power consumption while complying with the SLA by maximizing physical machine(PM)-level utilization and load balancing techniques in infrastructure as a service.However,with the recent introduction of container as a service by cloud providers,containers are increasingly popular and will become the major deployment model in the cloud environment and specifically in platform as a service.Therefore,reducing power consumption while complying with the SLA at virtual machine(VM)-level becomes essential.In this context,we exploit a container consolidation scheme with usage prediction to achieve the above objectives.To obtain a reliable characterization of overutilized and underutilized PMs,our scheme jointly exploits the current and predicted CPU utilization based on local history of the considered PMs in the process of the container consolidation.We demonstrate our solution through simulations on real workloads.The experimental results show that the container consolidation scheme with usage prediction reduces the power consumption,number of container migrations,and average number of active VMs while complying with the SLA.