利用干式磁选工艺回收铁矿石资源的试验研究

大孤山铁矿在矿体深部矿岩分界线处多个采矿部位出现低品位矿石或混岩，因为综合品位低，无法进行利用，只能作为岩石抛弃，造成矿石资源的流失和浪费。本试验探讨用干式磁选工艺从排岩中回收铁矿石的可行性，对于回收铁矿资源、降低采矿生产成本、提高资源利用率、保护环境具有重要意义。     

Utility optimization scheduling for multi-point video surveillance in ubiquitous network

Resource allocation is an important problem in ubiquitous network. Most of the existing resource allocation methods considering only wireless networks are not suitable for the ubiquitous network environment, and they will harm the interest of individual users with instable resource requirements. This paper considers the multi-point video surveillance scenarios in a complex network environment with both wired and wireless networks. We introduce the utility estimated by the total costs of an individual network user. The problem is studied through mathematical modeling and we propose an improved problem-specific branch-and-cut algorithm to solve it. The algorithm follows the divide-and-conquer principle and fully considers the duality feature of network selection. The experiment is conducted by simulation through C and Lingo. And it shows that compared with a centralized random allocation scheme and a cost greed allocation scheme, the proposed scheme has better per- formance of reducing the total costs by 13.0% and 30.6% respectively for the user.     

Rate-distortion optimized unequal loss protection for video transmission over packet erasure channels

Video transmission over networks often suffers from packet loss due to network congestions and stringent end-to-end delay constraints. In this paper, we develop a Rate-Distortion optimized Unequal Loss Protection (RD-ULP) scheme to combat packet loss. Based on packet-level transmission distortion modeling, we estimate the amount of contribution of each video packet to the reconstructed video quality, which defines the priority level of each packet. Unequal amounts of protection are then allocated to different video packets according to their priority levels and the dynamic channel conditions. The proposed RD-ULP resource allocation problem is formulated as a constrained nonlinear optimization problem. An optimization algorithm based on Particle Swarm Optimization (PSO) is then developed to solve the optimal resource allocation problem. Our extensive experimental results demonstrate the effectiveness of the proposed RD-ULP scheme, which outperforms existing methods by up to 2 dB in the reconstructed video quality.     

Multicoloring trees

Scheduling jobs with pairwise conflicts is modeled by the graph multicoloring problem. It occurs in two versions: in the preemptive case, each vertex may get any set of colors, while in the non-preemptive case, the set of colors assigned to each vertex has to be contiguous. We study these versions of the multicoloring problem on trees, under the sum-of-completion-times objective. In particular, we give a quadratic algorithm for the non-preemptive case, and a faster algorithm in the case that all job lengths are short, while we present a polynomial-time approximation scheme for the preemptive case.     

基于参数优化的WCDMA网络拥塞处理方法研究

中国联通广西分公司针对WCDMA网络中出现的CE资源、码资源、功率资源等网络资源拥塞导致用户感知下降的问题,通过研究无线资源调度机制和原理,制定了基于参数优化的多种创新性解决方案,最终成功地解决或改善了WCDMA网络拥塞问题.     

基于粒子群优化的负载均衡的虚拟网络映射

虚拟网络映射忽略通信路径上中间节点的资源消耗,以底层物理网络资源消耗最小或路径最短为目标,导致最优路径上中间节点资源不足而出现瓶颈,影响整个底层网络的性能及后续虚拟网络请求成功率。该文针对这一问题考虑物理路径上中间节点资源消耗,以节点负载和链路负载同时达到均衡为目标,将路径跳数限制作为约束,建立虚拟网络映射的数学模型,并采用多目标负载均衡粒子群优化算法求解,记作 LB-PSO。实验证明该算法有效地消除了资源瓶颈,为后续虚拟网络请求提供一个更为均衡的底层物理网络,从而提高了虚拟网络构建成功率、网络资源利用率以及基础设施提供商的收益。     

Numerical modeling of Basin and Range geothermal systems

Basic qualitative relationships for extensional geothermal systems that include structure, heat input, and permeability distribution have been established using numerical models. Extensional geothermal systems, as described in this paper, rely on deep circulation of groundwater rather than on cooling igneous bodies for heat, and rely on extensional fracture systems to provide permeable upflow paths. A series of steady-state, two-dimensional simulation models is used to evaluate the effect of permeability and structural variations on an idealized, generic Basin and Range geothermal system of the western U.S.Extensional geothermal systems can only exist in a relatively narrow range of basement (bulk) permeability (10⁻¹⁵ m² to 10⁻¹⁶ m²). Outside of this window, shallow subsurface fault zone temperatures decrease rapidly. Mineral self-sealing does not significantly affect the flow system until the flow path is almost completely sealed off. While topography gives an extra “kick” to convective circulation, it is not a requirement for geothermal system development. Flow from the ranges to the fault dominates the circulation, while secondary flow systems exist on the range front slopes. A permeable fault in one valley can also induce cross-range flow if there are no equally good upflow paths in the adjacent valleys. When bulk permeability is high enough, additional deep circulation cells develop in adjacent valleys, diverting heat and fluid from the fault and consequently reducing temperatures in the fault itself. Qualitative comparison between temperature–depth logs from actual geothermal systems and from the generic models is a significant aid to understanding real-world geothermal fluid flow, and suggests new or better interpretations of existing systems.     

Static and dynamic performance evaluation of a commercially-available ultra wideband tracking system

Locating and tracking resources (e.g., people, equipment, and materials) is critical in many industrial applications for monitoring productivity and safety. In construction, various technologies (e.g., global positioning systems (GPS), radio frequency identification (RFID) and radio frequency (RF) localization) have been proposed. However, the performance of these types of technologies is not well understood for this particular application. This paper presents a study for evaluating the static and dynamic performance of a commercially-available ultra wideband (UWB) tracking system in free space and under realistic construction environments. In addition, a static performance model for estimating position error as a function of receiver position and initial calibration error was also developed. Results and experiences are in particular useful for researchers or practitioners in need for adapting UWB technology for their application.     

事件之后 2010年上海世博会的可持续发展思考

文章从社会发展策略、规划策略、建筑策略、技术策略等层面对2010年上海世博会可持续发展进行全面理性思考,提出"事件"效应与社会能耗的对应关系,资源与人均资源的矛盾关系,永久与临时的平衡关系,实验与适宜的发展关系。     

武汉“城市视频监控系统建设”项目系统

分析武汉城市视频监控系统的现状,介绍武汉城市视频监控系统建设项目,总结项目建设中的创新点。