Service-oriented architectural model for generating system adequacy evaluation

Effect of a pumped storage plant on the generation reliability of the Taiwan power system

Chapter 4 - Identifying And Avoiding SOA Performance Problems

Chapter 7 - Writing SOAP Servers

Simple object access protocol (SOAP) is the communication protocol used by web services to communicate between systems. Since SOAP messages have the ability to bypass firewalls and directly get processed by web servers, their security is critical to the security of the web servers. Secure transit of SOAP messages plays a critical role for the applicability of web services. At present, internet users authenticate themselves using credential are vulnerable to security threats in presence of active attackers. This imposes a burden on users to manage their credentials in different ways. Along with the thorough development and application for web services, the security of it has taken people's attention more and more. While web services security (WSS) can exchange safe SOAP message and enhance the security of web services, it will also have certain influence to the performance of web services. This paper explore the security vulnerability of SOAP message transaction and taking advantage of the existing technologies and solutions related to SOAP and web services, we developing a highly developed security model. This model is useful for solving the problem between security and performance contradiction.

Current learning approaches are teacher oriented. The teacher is in control of the elements of the entire learning process. But different students have different capabilities and constraints. The student should be able to select the teaching style and method that best meets his requirements, while taking into consideration his capabilities and constraints. Due to the wide popularity of service-oriented architecture (SOA) and cloud computing, we propose an extended SOA model. This model extends traditional SOA models to support the provision of richer services that enable service providers to reach a wide range of customers and enable service requesters to find services that best match their requirements taking into consideration their capabilities. In the context of this paper, service providers are course providers and service requesters are the students. This paper also introduces a novel formal model for the specification of our newly introduced richer services.

Cloud computing uses internet and remote servers for maintaining data and applications. It offers through internet the dynamic virtualized resources, bandwidth and on-demand software's to consumers and promises the distribution of many economical benefits among its adapters. It helps the consumers to reduce the usage of hardware, software license and system maintenance. Simple Object Access Protocol (SOAP) is the system that allows the communications interaction between different web services. SOAP messages are constructed using either HyperText Transport Protocol (HTTP) and/or Extensible Mark-up Language (XML). The new form of Distributed Denial of Service (DDoS) attacks that could potentially bring down a cloud web services through the use of HTTP and XML. Cloud computing suffers from major security threat problem by HTTP and XML Denial of Service (DoS) attacks. HX-DoS attack is a combination of HTTP and XML messages that are intentionally sent to flood and destroy the communication channel of the cloud service provider. To address the problem of HX-DoS attacks against cloud web services there is a need to distinguish between the legitimate and illegitimate messages. This can be done by using the rule set based detection, called CLASSIE and modulo marking method is used to avoid the spoofing attack. Reconstruct and Drop method is used to make decision and drop the packets on the victim side. It enables us to improve the reduction of false positive rate and increase the detection and filtering of DDoS attacks.

This paper describes the proposed smart transducer Web services (STWS) developed at the National Institute of Standards and Technology (NIST) based on the IEEE 1451.0 standard. The STWS are described in WSDL (Web service description language). A prototype system has been established to test the STWS. This prototype system consists of a service consumer, service provider (wireless network node), and wireless sensor node. The service consumer and provider can communicate with each other through SOAP (simple object access protocol) messages. The STWS were tested successfully through a case study of reading an IEEE 1451 TEDS (transducer electronic data sheet). The proposed STWS provide a standard way for IEEE 1451 applications to achieve interoperability with other sensor applications in WSDL. Hence it provides a foundation for STWS standardization.

The frequency and duration method has been developed for the evaluation of generating system reliability in the planning of electric power systems. This method makes it possible to determine all major reliability indices: probability and frequency of system deficiency states and the expected energy not supplied to the consumers. For practical applications, simple two-level daily load models have been suggested. The higher load level is taken to match with the estimated daily load peak and the lower level is usually assumed to be equal to mean value for different days. The duration of the higher load level is adopted to be the same for all days but no recommendation has been given as to how to choose it. To investigate the applicability of two-level load models for assessing generation system reliability for planning purposes, a series of comparative analyses of the IEEE Reliability Test System has been performed, applying the exact and various two-level load models. The applicability of two-level models in estimating the absolute and relative system reliability indices is analysed for various generation system structures and load diagram shapes. It has been shown that the two-level load approximation offers a very good estimation of the relative values of all main reliability indices of the prospective generation systems. It has also been established that the two-level diagrams provide fair estimates of the absolute values of the reliability frequency in most cases investigated. This good behaviour of the two-level models has also been found to hold if there are some predictable as well as unpredictable load diagram shape modifications.

Due to complex infrastructure of web application response time for different service request by client requires significantly larger time. Simple Object Access Protocol (SOAP) is a recent and emerging technology in the field of web services, which aims at replacing traditional methods of remote communications. Basic aim of designing SOAP was to increase interoperability among broad range of programs and environment, SOAP allows applications from different languages, installed on different platforms to communicate with each other over the network. Web services demand security, high performance and extensibility. SOAP provides various benefits for interoperability but we need to pay price of performance degradation and security for that. This formulates SOAP a poor preference for high performance web services. In this paper we present a new approach by enabling multi-level caching at client side as well as server side. Reference describes implementation based on the Apache Java SOAP client, which gives radically enhanced performance.

standards track protocol for the Internet community, and requests discussion and suggestions for improvements.Please refer to the current edition of the "Internet Official Protocol Standards" (STD 1) for the standardization state and status of this protocol.Distribution of this memo is unlimited.

Dynamic regulation reliability of a pumped-storage power generating system: Effects of wind power injection

The problem of reliability and exploitation analysis of power systems used in intelligent transport systems (ITS) is extremely important from the point of view of ensuring the traffic safety. The use of advanced electronic devices in ITS systems requires their power supply from properly designed power systems. To ensure the continuity of operation of electronic devices, the basic and backup power supply are most often used. They should have specific values of reliability and performance indicators. Therefore, a reliability and exploitation model of the power system has been developed, taking into account renewable energy sources (RES), such as used in intelligent transport systems. This allowed to obtain dependencies enqabling to determine the probability of staying of the power system used in the intelligent transport system in the specified reliability and exploitation states.

Power systems with high renewable energy sources: A review of inertia and frequency control strategies over time

Electromagnetic transients of a micro-turbine based distributed generation system

Electric power systems are critical infrastructures subject to the possibility of extraordinary events with high societal consequences. Although such possibilities are often associated with very low probabilities of being realized, it is nevertheless crucial to be able to identify and understand the vulnerabilities of power systems related to extraordinary events. The objective of the work presented in this article is to establish a methodological basis for vulnerability analysis that is complementary to conventional risk and reliability analysis of power systems. It presents a comprehensive framework of definitions, indicators and methods that can be used to classify, analyse and monitor vulnerabilities in power transmission and distribution systems. Its main components include (1) a conceptual framework of definitions that forms the basis for understanding and classifying vulnerabilities, (2) an assessment methodology for identifying vulnerabilities related to extraordinary events and barriers to mitigate them, and (3) vulnerability indicators for quantifying and monitoring power system vulnerabilities. The applicability of the vulnerability analysis framework is demonstrated through several studies of real power systems. Moreover, the concept of power system vulnerability elaborated in this article is also related to the concept of power system resilience.