A Web Cache Replacement Strategy for Safety-Critical Systems

A Safety-Critical System (SCS), such as a spacecraft, is usually a complex system. It produces a large amount of test data during a comprehensive testing process. The large amount of data is often managed by a comprehensive test data query system. The primary factor affecting the management experience of a comprehensive test data query system is the performance of querying the test data. It is a big challenge to manage and maintain the huge and complex testing data.To address this challenge, a web cache replacement algorithm which can effectively improve the query performance and reduce the network latency is needed. However, a general-purpose web cache replacement algorithm usually cannot be directly applied to this type of system due to the low hit rate and low byte hit rate. In order to improve the hit rate and byte hit rate, a data stream mining technology is introduced, and a new web cache algorithm GDSF-DST (Greedy Dual-Size Frequency with Data Stream Technology) for the Safety-Critical System (SCS) is proposed based on the original GDSF algorithm. The experimental results show that compared with state of the art traditional algorithms, GDSF-DST achieves competitive performance and improves the hit rate and byte hit rate by about 20%

Efficient Frontier and Benchmarking Models for Energy Multicast in Wireless Network Coding

This chapter introduces efficiency frontier and benchmarking concepts to evaluate the efficiency performance of wireless networks for multicast energy. These concepts are efficiency models based on the data envelopment analysis (DEA) technique. The DEA framework allows network administrators to evaluate the technical efficiency and determine how the inefficient wireless networks will attain a targeted efficiency frontier. In order to achieve efficiency frontier and benchmark by a wireless network, this chapter presents several models including the envelopment and the slack. The envelopment model evaluates the technical efficiency scores of each wireless network, while the slack model shows how the inefficient wireless network achieves efficiency frontier. The benchmark model evaluates the efficiency reference set and the lambda values of each network. The efficiency frontier algorithm has shown that many of the wireless networks sampled are inefficient. However, the algorithm has capability to help the inefficient wireless networks to achieve efficiency frontier and benchmark with their peers that are fully efficient

The impact of credit and operational risk on islamic and conventional bank efficiency in Malaysia

In banking sector, evaluation of performance and productivity are among fundamental concepts in management to achieve firm’s goals. High levels of efficiency through performance and continuous efforts of managers are needed in order to be successful in the competitive markets. Institutions need to know their relative success according to performance in comparison with similar institutions and their performance for the past years. In this study, the economic efficiency was analyzed and compared in terms of risk factors for Islamic and conventional banks in Malaysia for the period of 2008 to 2012. The study was conducted on the banks certified by Central Bank of Malaysia (Bank Negara) which includes both Islamic and conventional branches. Data was collected from annual financial reports such as balance sheets and income statements. Data envelopment analysis (DEA) was implemented to determine and analyze the economic efficiency. Based on the intermediation approach, three inputs and two outputs were selected. Basel 2 was used to define the credit and operational risks on efficiency. In addition, DEA network model was proposed to estimate the overall efficiency (with regard to credit and operational risk) of banks and to specify the difference between Islamic and conventional banks in terms of efficiency using the nonparametric test such as Mann-Whitney and Wilcoxon. The result indicates that the credit and operational risk have significant impact on efficiency for both Islamic and conventional banking system. The non-performing loan has negative impact on efficiency in both Islamic and conventional banks which leads to undesirable output of banking system. In contrast, return on equity and return on assets show positive impact on efficiency of banks in Malaysia. The results also reveal that the efficiency of Islamic banks in Malaysia is higher than conventional and the differences are statistically significant. In addition, the efficiency is higher than the overall efficiency (efficiency with regard to credit and operational risk) of banks in Malaysia. The finding also indicates that there is no difference between overall efficiency of Islamic and conventional banks in Malaysia

Novel approaches to performance evaluation and benchmarking for energy-efficient multicast: empirical study of coded packet wireless networks

With the advancement of communication networks, a great number of multicast applications such as multimedia, video and audio communications have emerged. As a result, energy efficient multicast in wireless networks is becoming increasingly important in the field of Information and Communications Technology (ICT). According to the study by Gartner and Environmental Protection Agency (EPA) report presented to United State Congress in 2007,energy consumption of ICT nodes accounts for 3% of the worldwide energy supply and is responsible for 2% of the global Carbon dioxide (CO2) emission. However, several initiatives are being put in place to reduce the energy consumption of the ICT sector in general. A review of related literature reveals that existing approaches to energy efficient multicast are largely evaluated using a single metric and while the single metric is appropriate for effective performance, it is unsuitable for measuring efficiency adequately. This thesis studied existing coded packet methods for energy efficiency in ad hoc wireless networks and investigates efficiency frontier, which is the expected minimum energy within the minimum energy multicast framework. The energy efficiency performance was based on effective evaluation and there was no way an inefficient network could reach a level of being an efficiency frontier. Hence, this work looked at the position of how true efficiency evaluation is obtained when the entire network under examination attains their efficiency frontiers using ratios of weighted outputs to weighted inputs with multiple variables. To address these challenges and assist network operators when formulating their network policies and performing network administrations, this thesis proposed novel approaches that are based on Data Envelopment Analysis (DEA) methodology to appropriately evaluate the efficiency of multicast energy and further minimizes energy transmission in ad hoc wireless networks without affecting the overall network performance. The DEA, which was used to study the relative efficiency and productivity of systems in Economic and Operational Research disciplines, is a non-parametric method that relies on linear programming technique for optimization of discrete units of observation called the decision making units (DMUs)

Temporal meta-model framework for Enterprise Information Systems (EIS) development

This thesis has developed a Temporal Meta-Model Framework for semi-automated Enterprise System Development, which can help drastically reduce the time and cost to develop, deploy and maintain Enterprise Information Systems throughout their lifecycle. It proposes that the analysis and requirements gathering can also perform the bulk of the design phase, stored and available in a suitable model which would then be capable of automated execution with the availability of a set of specific runtime components

Sustainability and Related Factors of High Speed Railways

High-Speed Railways (HSR), which represent a safe and sustainable mode of transportation, provide access and mobility for the society, and support the growth of the economy in addition to creating new jobs, supporting welfare, and promoting local business activities. This research addresses the shortage of knowledge in evaluating the performance of selected HSR systems and in distinguishing the factors that contribute to the sustainable performance of HSRs. The aim of this study is to evaluate the sustainability of selected HSRs and identify factors that affect such sustainability. The objectives of this research are to evaluate productivity, technical and technological efficiency of the selected HSRs, define the factors that can affect productivity and efficiency scores and make suggestions for improving the sustainability of HSRs. The secondary data methodology has been used, supported by empirical evidence. Most of the data was gathered from the Internet, research in depth of the high-speed railways in the selected countries, and International Union of Railway’s websites in addition to analysing railway statistics and data from European and institutional publications. This includes the use of a multi-stage approach of applying three specialised software packages, namely, NVivo, DEA, and ISM SPSS. The main findings show that HSRs in Asia has higher productivity and higher efficiency scores than that of HSRs in Europe. The research found that the key factors among all the identified factors that affected the productivity and efficiency of HSRs are; density of population, average traction power of HSR trains, average time that passengers spend on trains and average distance that passengers travel on the HSR. The findings of this research can help develop strategic guidelines to improve the performance and, by the result, the sustainability of HSRs. The recommendations are drawn for more research expansion, including the consideration of other HSRs, particularly their best practices

Products and Services

Today’s global economy offers more opportunities, but is also more complex and competitive than ever before. This fact leads to a wide range of research activity in different fields of interest, especially in the so-called high-tech sectors. This book is a result of widespread research and development activity from many researchers worldwide, covering the aspects of development activities in general, as well as various aspects of the practical application of knowledge

Sonic interactions in virtual environments

This book tackles the design of 3D spatial interactions in an audio-centered and audio-first perspective, providing the fundamental notions related to the creation and evaluation of immersive sonic experiences. The key elements that enhance the sensation of place in a virtual environment (VE) are: Immersive audio: the computational aspects of the acoustical-space properties of Virutal Reality (VR) technologies Sonic interaction: the human-computer interplay through auditory feedback in VE VR systems: naturally support multimodal integration, impacting different application domains Sonic Interactions in Virtual Environments will feature state-of-the-art research on real-time auralization, sonic interaction design in VR, quality of the experience in multimodal scenarios, and applications. Contributors and editors include interdisciplinary experts from the fields of computer science, engineering, acoustics, psychology, design, humanities, and beyond. Their mission is to shape an emerging new field of study at the intersection of sonic interaction design and immersive media, embracing an archipelago of existing research spread in different audio communities and to increase among the VR communities, researchers, and practitioners, the awareness of the importance of sonic elements when designing immersive environments