Different from recent probabilistic packet marking (PPM) methods, Dynamic PPM may solve many problems of traditional methods, such as loss of marking information, hard to reconstruct attack path, low accuracy, and so on. A novel DPPM approach is proposed and the network simulation software (NS2) is used to verify the performance and efficiency of the approach by constructing simulation DOS environments. In comparison with PPM methods, simulation results show that DPPM is much better.

This paper has a discussion on the new solution of IGMP management for multicast message in industrial Ethernet. It proposed a new mechanism to minimize the congestion which is based on the taking an adaptive decision during transferring multicast messages. Proposed approach is that a device requesting to start and stop the reception of the multicast streams is accomplished through IGMP join and Leave message requests. Quality of Service (QOS) as a component is supported by the Switch Manager as well as features built into the micro chip. The IGMP Snooping component monitors (snoops) these join and leave messages to allow it to know which streams to prune from which ports. it is a service provided by most managed Ethernet switches. However, the ICIE (Intelligent Controller for Industrial Ethernet) does not provide this capability and requires that another device in the network supports the querier functionality. It is through the external devices solicitation of join messages that allow the IGMP Snooping component to correctly decipher on which ports the downstream listeners are connected.

This paper mainly studies the method of static analysis techniques; discuss static analysis techniques status and progress, as well as the characteristics of static analysis.

In order to improve the comprehensive qualities of students in all respects, fully reflect and evaluate the achievements of students, inspire students to improve themselves unceasingly, encourage them to strive to be the best, develop their personalities and strive for truth and innovation, as well as achieve the institutionalization, standardization and scientificalness of students management work gradually, meanwhile, along with the development of university construction and students management, maintenance and management of students' data information has been exceptionally heavy, so it cries out for a set of reasonable and convenient students quality evaluation system. Students' quality evaluation system is designed to make better use of computer technology in managing and inquiring about total performance of students' qualities. Through analysis of the objective of system construction, combining design principle of the system, this thesis analyses and designs the quality evaluation system archite cture from the perspectives of architecture, function module and security model.

Enhancing network performance has been studied by a number of researchers. The need to provide greater throughput on network infrastructure has been the key driver for these studies. The use of jumbo frames is considered one of the methodologies that can be employed to increase data throughput on networks. In this research undertaking, the authors implement jumbo frames on a test-bed implemented with Windows Server 2003/2008 networks and performance related metrics are measured for both IPv4 and IPv6 implementations. The results obtained in this empirical study shows that performance metrics values are different in various scenarios.

A performance evaluation method of wireless sensor networks based on gray theory is proposed. Firstly the influence factors of performance are analyzed, and the index set in evaluation of wireless sensor networks' performance is built which include index of key performance and reliable characteristics. Based on AHP and gray theory, a model of evaluation of wireless sensor networks performance is given. Finally the results of example show that the evaluation model is rationality and feasibility.

This paper proposes a novel approach to emulate an arbitrary wireless multi-hop network scenario in a fixed wireless test-bed, in which every node is equipped with a variable attenuator. We take notice of the interval equivalent character of wireless communication and consider the wireless multi-hop scenario emulation problem as an interval equivalent emulation problem. We define the generalized error, which is an error of a value relative to an interval, formulate the MinGenMax (Minimize Generalized Maximum) error problem and propose an optimum algorithm.

In some oil fields of China, monitoring oil temperature during producing almost relies on manual operation. According to this, we designed a solution based on Zigbee network and sensor technology. In our design of sampling nodes, with JN5139 module as the core, uses sensor PT100 to collect temperature data and LCD module LCM141C-01 to display the final result. The whole solution has an advantage of a simple structure, low power consumption etc, therefore, it has a positive meaning in improving monitoring work efficiency in oil fields.

WiMAX based on IEEE 802.16 is known as one of effective technologies for transmission of multimedia to groups of receivers. There are two operational modes in WiMAX: point to multi point (PMP) for single hop transmission and a mesh node for multi-hop transmission. The current standard only defines unicast transmission under mesh mode thus the performance is deteriorated for multimedia applications with multicast nature. In this paper, we first propose a mechanism for source-based tree topology construction aiming at facilitating multicast transmission in WiMAX mesh network. In the proposed approach, the multicast tree is constructed considering available link's bandwidth and multicast group members. After constructing the multicast tree we propose a novel scheduling algorithm to improve the transmission throughout. In the proposed scheduling algorithm a parent node uses broadcasting when the number of its children belonging to a multicast group excesses a threshold. Extensive simulation results show that the proposed multicast mechanism improves multicast transmission efficiency and reduces scheduling time slots noticeably in comparison to the approach mandated by the IEEE 802.16 standard.

Due to the dynamics of Web services, the openness and variability of Internet, and the loosely-coupled developing approach of Web services, the development and execution process of Web service compositions becomes uncertain, which imperils the trustworthy properties. In this paper we abstract Web service compositions as multi-agent systems, propose a formal model BSTS for modeling BPEL, develop and implement two translation algorithms B2S and S2I, to translate BPEL into BSTS and translate BSTS into the input language ISPL of the model checker MCMAS for multi-agent systems, respectively. The proposed method supports not only temporal properties, but also epistemic and cooperation properties, which are supported only in multi-agent systems. We implemented the prototype tool, called MCWS, for the proposed method. We modeled and verified an example of Web service compositions. The experimental results show the validity of MCWS.