A two-tier location management mechanism for IMS

This paper proposed a two-tier location management mechanism （TTLM） by improving the current registration mechanism （CR） in IP Multimedia Subsystem （IMS）. The TTLM includes the visited network registration and the home network registration, in which the visited network registration is responsible for re-registration in IMS. When subscriber roams, the location information of home network will be updated by the visited network based on the change of user equipment （UE）＇ s IP address. Thereibre the TTLM can reduce the times of IMS registration signaling. Using the proposed analytical model, the performance of the CR and the proposed TTLM were investigated. After the performance analysis of CR and TTLM by using proposed analytical model, the cost of CR in IMS could significantly be reduced theoretically and also was proven by simulation experiments.

基于通用黑板模型的IMSE网络中心节点识别

运用通用黑板理论和D-S证据理论探索IMSE网络中心节点识别问题。构建了基于通用黑板框架的IMSE网络中心节点识别模型,讨论了该模型体系的体系结构和实现方法,对该模型的工作流程进行了详细论述。给出了一种基于D-S证据理论的高效识别规则。该系统中专家系统直接给出了基本概率赋值,减少了计算繁琐程度,从而可大大减轻目标识别系统的压力。最后通过仿真结果具体分析了模型的工作情况。

An rFC based service triggering algorithm for IMS network

To reduce the potential signaling traffic in IP multimedia subsystem （IMS）, the session establishment procedures were investigated. The serving call session eontrol function （S-CSCF） is the major bottleneck in IMS and the existing 3GPP service triggering algorithm （STA） based on initial filter eriteria （iFC） increases the end-to-end session setup delay remarkably. To reduce the session setup delay and improve the system performanee, a SIP response message based filter criteria （rFC） was proposed. Based on the rFC, a SIP response message based STA （RSTA） was further proposed. The modeling and theoretical analysis of 3GPP STA and RSTA were presented. Simulation results show that, compared with 3GPP STA, the RSTA can avoid the additional signaling traffie load of the S-CSCF and application server （AS） effectively, reduce the session setup delay eonsiderably, increase the throughput of the S-CSCF and improve the quality of service （QoS） of IMS network.

Seamless Handover for IMS over Mobile-IPv6 Using Context Transfer

Mobility support for the next generation IPv6 networks has been one of the recent research issues due to the growing demand for wireless services over internet.In the other hand,3GPP has introduced IP Multimedia Subsystem as the next generation IP based infrastructure for wireless and wired multimedia services.In this paper we present two context transfer mechanisms based on predictive and reactive schemes,to support seamless handover in IMS over Mobile IPv6.Those schemes reduce handover latency by transferring appropriate session information between the old and the new access networks.Moreover,we present two methods for QoS parameters negotiations to preserve service quality along the mobile user movement path.The performances of the proposed mechanisms are evaluated by simulations.

ON PERFORMANCE OF APPLICATION TRIGGERING ARCHITECTURE IN IMS NETWORK

The modeling of Application Triggering Architecture （ATA） in the IP Multimedia Sub- system （IMS） is presented. The session setup delay and system throughput are employed as the measurement to investigate the performance of ATA and the Serving Call Session Control Punction （S-CSCF）. With theoretical analysis and simulation results, we find that, the number of the ASs （Application Servers）, the use of the subsequent Filter Criteria （sFC） and the arrival rate have heavy impact on the session setup delay and the S-CSCF is the major bottleneck in IMS network. The results are useful in constructing IMS network. At last, we propose several possible solutions to reduce the session setup delay and decrease the load of the S-CSCF.

STUDY ON THE ACCOUNT-SHARING STRATEGY FOR MULTI-SERVICES IN IMS ONLINE CHARGING MECHANISM

A prepaid subscriber is allowed to simultaneously implement multiple services in online charging mechanism of IP Multimedia Subsystem (IMS). It is a noteworthy discussion to effectively distribute the limited account resources among concurrent services. An account-sharing algorithm is proposed for multi-services,which introduces resource reclamation and redistribution processes based on the resource reservation of standard specifications and dynamically adjusts them according to the changes of Quality of Service (QoS). Three performance indexes are investigated in the simulation experiments, which are average number of accommodated sessions, average number of completed ses- sions, and average number of iterations per accommodated session. The results show that in the normal QoS level, the three indexes of the proposed algorithm averagely increase by 18.7%, 5.4%, and 3.1% compared with the Prepaid Credit Distribution (PCD) algorithm, and by 2.1%, 1.0%, and 1.8% compared with the Prepaid Credit Reclaim (PCR) algorithm. In the poor QoS level, the performance advantages are greater, which averagely increase by 29.1%, 7.1%, and 2.8% compared with PCD, and by 9.4%, 4.1%, and 3.6% compared with PCR.

Forage Species Suitability Mapping for China Using Topographic, Climatic and Soils Spatial Data and Quantitative Plant Tolerances

Selecting plants adapted to the climatic and soil conditions of specific locations is essential for environmental protection and economic sustainability of agricultural and pastoral systems. This is particularly true for countries like China with a diversity of climates and soils and intended uses. Currently, proper species selection is difficult due to the absence of computer-based selection tools. Climate and soil GIS layers, matched with a matrix of plant characteristics through rules describing species tolerances would greatly improve the selection process. Better matching will reduce environmental hazards and economic risks associated with sub-optimal plant selection and performance. GIS-based climate and soil maps have been developed for China. A matrix of quantitative species tolerances has been developed for example forage species and used in combination with an internet map server that allows customized map creation. A web-based decision support system has been developed to provide current information and links to original data sources, supplementary materials, and selection strategies.

继电保护装置缺陷分析及提高运行水平的建议

根据甘肃电网近几年来220kV及以上系统微机继电保护存在不正确动作的情况,结合实际故障事例对装置存在的缺陷进行了分类分析,如装置算法、装置软件、装置硬件、装置原理、装置的升级服务配合等方面的分析,并对提高继电保护装置的运行水平提出了技术措施,建议进行继电保护装置的应用检测,采用继电保护数字仿真试验系统等。

NOVEL SENSORLESS VECTOR CONTROL SYSTEM OF INDUCTION MACHINE BASED ON FLUX OBSERVER IN FIELD WEAKENING

A speed-sensorless vector control system for induction machines （IMs）is presented, According to the vector control theory of IMs, the rotor flux is estimated based on a flux observer,and the speed is estimated through the method of q-axis rotor flux converging on zero with proportional integral regulator, A 0.75 kW,50 Hz,two-pole induction machine was used in the simulation and experimental verification, The simulation model was constructed in Matlab. A series of tests were performed in the field weakening region, for both no-load and loaded operation. The estimated speed tracks the actual speed well in the based speed region and field weakening region （ 1 per unit value to 4 per unit value）. The small estimation error of residual speed is due to the existence of slip.

Integration of Individualized Management Systems （MSs） as an Aggregating Factor of Sustainable Value for Organizations An Overview Through a Review of the Literature

Nowadays, there exist various standards for individual management systems （MSs）, at least, one for each stakeholder. New ones will be published. An integrated management system （IMS） aims to integrate some or all components of the business into one coherent and efficient MS. Maximizing integration is more and more a strategic priority in that it constitutes an opportunity to eliminate and/or reduce potential factors of destruction of value for the organizations and also to be more competitive and consequently promote its sustainable success. A preliminary investigation was conducted on a Portuguese industrial company which, over the years, has been adopting gradually, in whole or in part, individualized management system standards （MSSs）. A research, through a questionnaire, was performed with the objective to develop, in a real business environment, an adequate and efficient IMS-QES （quality, environment, and safety） model and to potentiate for the future a generic IMS model to integrate other MSSs. The strategy and research methods have taken into consideration the case study. It was obtained a set of relevant conclusions resulting from the statistical analyses of the responses to the survey. Globally, the investigation results, by themselves, justified and prioritized the conception of a model of development of the IMS-QES and consequent definition and validation of a structure of an IMS-QES model, to be implemented at the small- and medium-sized enterprise （SME） where the investigation was conducted.

低苯乙烯散发性胶衣树脂的新发展

本文综述了三种低苯乙烯散发性胶衣树脂。

Impact of Ocean-Continent Distribution over Southern Asia on the Formation of Summer Monsoon

Using the CCM3/NCAR, a series of numerical experiments are designed to explore the effect of ocean-land interlaced distributions of Africa-Arabian Sea-India Peninsula-Bay of Bengal （BOB）-Indo-China Peninsula- South China Sea on the formation of the Asian summer monsoon circulation （ASMC）. The results show that the thermal difference between African or Indian Subcontinent and nearby areas including the Indian Ocean, Arabian Sea, and part of BOB is the primary mechanism that maintains the Indian monsoon circulation. In the experiment getting rid of these two continents, the Indian monsoon system （IMS） members, i.e., the Somali cross-equatorial jet （40°E） and the southwesterly monsoon over the Arabian Sea and BOB, almost disappear. Moreover, the Hadley circulation weakens dominantly. It also proves that Africa has greater effect than Indian Subcontinent on the IMS. However, the existence of Indo-China Peninsula and Australia strengthens the East Asian monsoon system （EAMS）. The thermal contrast between Indo-China Peninsula and SCS, Australia and western Pacific Ocean plays an important role in the formation of the tropical monsoon to the south of the EAMS. When the Indo-China Peninsula is masked in the experiment, the cross-equatorial flow （105°E and 125°E） vanishes, so does the southwesterly monsoon usually found over East Asia, and EAMS is enfeebled significantly. In addition, the impacts of these thermal contrasts on the distribution of the summer precipitation and surface temperature are investigated.