Impact of denial of service solutions on network quality of service

The Internet has become a universal communication network tool. It has evolved from a platform that supports best-effort traffic to one that now carries different traffic types including those involving continuous media with quality of service (QoS) requirements. As more services are delivered over the Internet, we face increasing risk to their availability given that malicious attacks on those Internet services continue to increase. Several networks have witnessed denial of service (DoS) and distributed denial of service (DDoS) attacks over the past few years which have disrupted QoS of network services, thereby violating the Service Level Agreement (SLA) between the client and the Internet Service Provider (ISP). Hence DoS or DDoS attacks are major threats to network QoS. In this paper we survey techniques and solutions that have been deployed to thwart DoS and DDoS attacks and we evaluate them in terms of their impact on network QoS for Internet services. We also present vulnerabilities that can be exploited for QoS protocols and also affect QoS if exploited. In addition, we also highlight challenges that still need to be addressed to achieve end-to-end QoS with recently proposed DoS/DDoS solutions. © 2010 John Wiley & Sons, Ltd.

Performance measurement of intensive care services in hospitals:The case of Barbados

The Intensive Care Unit (ICU) being one of those vital areas of a hospital providing clinical care, the quality of service rendered must be monitored and measured quantitatively. It is, therefore, essential to know the performance of an ICU, in order to identify any deficits and enable the service providers to improve the quality of service. Although there have been many attempts to do this with the help of illness severity scoring systems, the relative lack of success using these methods has led to the search for a form of measurement, which would encompass all the different aspects of an ICU in a holistic manner. The Analytic Hierarchy Process (AHP), a multiple-attribute, decision-making technique is utilised in this study to evolve a system to measure the performance of ICU services reliably. This tool has been applied to a surgical ICU in Barbados; we recommend AHP as a valuable tool to quantify the performance of an ICU. Copyright © 2004 Inderscience Enterprises Ltd.

A simulation study of service differentiation for the bandwidth request scheme in fixed IEEE 802.16 network

Various flexible mechanisms related to quality of service (QoS) provisioning have been specified for uplink traffic at the medium access control (MAC) layer in the IEEE 802.16 standards. Among the mechanisms, contention based bandwidth request scheme can be used to indicate bandwidth demands to the base station for the non-real-time polling and best-effort services. These two services are used for most applications with unknown traffic characteristics. Due to the diverse QoS requirements of those applications, service differentiation (SD) is anticipated over the contention based bandwidth request scheme. In this paper we investigate the SD with the bandwidth request scheme by means of assigning different channel access parameters and bandwidth allocation priorities at different packets arrival probability. The effectiveness of the differentiation schemes is evaluated by simulations. It is observed that the initial backoff window can be efficient in SD, and if combined with the bandwidth allocation priority, the SD performances will be better.

Call admission control algorithms in OFDM-based wireless multiservice networks

Orthogonal frequency division multiplexing (OFDM) is becoming a fundamental technology in future generation wireless communications. Call admission control is an effective mechanism to guarantee resilient, efficient, and quality-of-service (QoS) services in wireless mobile networks. In this paper, we present several call admission control algorithms for OFDM-based wireless multiservice networks. Call connection requests are differentiated into narrow-band calls and wide-band calls. For either class of calls, the traffic process is characterized as batch arrival since each call may request multiple subcarriers to satisfy its QoS requirement. The batch size is a random variable following a probability mass function (PMF) with realistically maximum value. In addition, the service times for wide-band and narrow-band calls are different. Following this, we perform a tele-traffic queueing analysis for OFDM-based wireless multiservice networks. The formulae for the significant performance metrics call blocking probability and bandwidth utilization are developed. Numerical investigations are presented to demonstrate the interaction between key parameters and performance metrics. The performance tradeoff among different call admission control algorithms is discussed. Moreover, the analytical model has been validated by simulation. The methodology as well as the result provides an efficient tool for planning next-generation OFDM-based broadband wireless access systems.

A survey of semantic web services formalisms

The field of Semantic Web Services (SWS) has been recognized as one of the most promising areas of emergent research within the Semantic Web initiative, exhibiting an extensive commercial potential and attracting significant attention from both industry and the research community. Currently, there exist several different frameworks and languages for formally describing a Web Service: Web Ontology Language for Services (OWL-S), Web Service Modelling Ontology (WSMO) and Semantic Annotations for the Web Services Description Language (SAWSDL) are the most important approaches. To the inexperienced user, choosing the appropriate platform for a specific SWS application may prove to be challenging, given a lack of clear separation between the ideas promoted by the associated research communities. In this paper, we systematically compare OWL-S, WSMO and SAWSDL from various standpoints, namely, that of the service requester and provider as well as the broker-based view. The comparison is meant to help users to better understand the strengths and limitations of these different approaches to formalizing SWS, and to choose the most suitable solution for a given application. Copyright © 2015 John Wiley & Sons, Ltd.

A survey of semantic web services formalisms

The field of Semantic Web Services (SWS) has been recognized as one of the most promising areas of emergent research within the Semantic Web (SW) initiative, exhibiting an extensive commercial potential, and attracting significant attention from both industry and the research community. Currently, there exist several different frameworks and languages for formally describing a Web Service: OWL-S (Web Ontology Language for Services), WSMO (Web Service Modeling Ontology) and SAWSDL (Semantic Annotations for the Web Services Description Language) are the most important approaches. To the inexperienced user, choosing the appropriate paradigm for a specific SWS application may prove to be challenging, given a lack of clear separation between the ideas promoted by the associated research communities. In this paper, we systematically compare OWL-S, WSMO and SAWSDL from various standpoints, namely that of the service requester and provider as well as the broker based view. The comparison is meant to help users to better understand the strengths and limitations of these different approaches to formalising SWS, and to choose the most suitable solution for a given use case. © 2013 IEEE.

Perceptions of journal quality and research paradigm:results of a web-based survey of British accounting academics

This paper reports the results of a web-based perception study of the ranking of peer reviewed accounting journals by UK academics. The design of the survey instrument allows an interactive selection of journals to be scored. The webbased format is unique in that it also includes a step in which respondents classify the journals according to methodological perspective (paradigm). This is depicted graphically in the paper in a bubble diagram that shows the "positioning" of journals according to perceptions of both paradigm and quality.

A profile of low vision services in England the Low Vision Service Model Evaluation (LOVSME) project

In the UK, low vision rehabilitation is delivered by a wide variety of providers with different strategies being used to integrate services from health, social care and the voluntary sector. In order to capture the current diversity of service provision the Low vision Service Model Evaluation (LOVSME) project aimed to profile selected low vision services using published standards for service delivery as a guide. Seven geographically and organizationally varied low-vision services across England were chosen for their diversity and all agreed to participate. A series of questionnaires and follow-up visits were undertaken to obtain a comprehensive description of each service, including the staff workloads and the cost of providing the service. In this paper the strengths of each model of delivery are discussed, and examples of good practice identified. As a result of the project, an Assessment Framework tool has been developed that aims to help other service providers evaluate different aspects of their own service to identify any gaps in existing service provision, and will act as a benchmark for future service development.

Towards an operations strategy for the infusion of product-centric services into manufacturing:service systems implementation

The work in this chapter is concerned with product-centric servitization. This is where a portfolio of services are formed and integrated to support product availability and use. Such servitization can be a valuable source of revenue for a manufacturer, yet little attention has been given to the configuration of the wider operations strategy that needs to be in place to deliver integrated products and services successfully. Therefore, the purpose of this chapter is to put forward a generic set of characteristics for such operations. Our intention is that these characteristics will be valuable to practitioners contemplating sophisticated forms of servitization, as they suggest the likely and significant changes that will be needed to the operations strategy of a conventional manufacturing organisation.

The relative influence of organisational commitment and job-satisfaction on service quality of customer-contact employees in banking call centres

An inter-disciplinary approach is adopted to provide a deeper understanding of the human resource-service quality relationship. The paper tests the relationships organisational commitment and job satisfaction have with service quality of customer-contact employees. Hypotheses are constructed by reviewing literature in the areas of human resource management and services marketing. A study comprising 342 employees was conducted in four telephone call centres of a major UK retail bank. Investigates how different forms of organisational commitment and job satisfaction influence the service quality delivered by contact employees. Findings indicate that job satisfaction and organisational commitment of employees have a significant impact on service quality delivered. The affective component of commitment was found to be more important than job satisfaction in determining service quality of customer-contact employees.

A comprehensive approach to quality management of intensive care services

Purpose – The purpose of this paper is to develop a comprehensive framework for improving intensive care unit performance. Design/methodology/approach – The study introduces a quality management framework by combining cause and effect diagram and logical framework. An intensive care unit was identified for the study on the basis of its performance. The reasons for not achieving the desired performance were identified using a cause and effect diagram with the stakeholder involvement. A logical framework was developed using information from the cause and effect diagram and a detailed project plan was developed. The improvement projects were implemented and evaluated. Findings – Stakeholders identified various intensive care unit issues. Managerial performance, organizational processes and insufficient staff were considered major issues. A logical framework was developed to plan an improvement project to resolve issues raised by clinicians and patients. Improved infrastructure, state-of-the-art equipment, well maintained facilities, IT-based communication, motivated doctors, nurses and support staff, improved patient care and improved drug availability were considered the main project outputs for improving performance. The proposed framework is currently being used as a continuous quality improvement tool, providing a planning, implementing, monitoring and evaluating framework for the quality improvement measures on a sustainable basis. Practical implications – The combined cause and effect diagram and logical framework analysis is a novel and effective approach to improving intensive care performance. Similar approaches could be adopted in any intensive care unit. Originality/value – The paper focuses on a uniform model that can be applied to most intensive care units.

Management of services differentiation and guarantee in IEEE 802.11e wireless LANs

In this paper, we study the management and control of service differentiation and guarantee based on enhanced distributed function coordination (EDCF) in IEEE 802.11e wireless LANs. Backoff-based priority schemes are the major mechanism for Quality of Service (QoS) provisioning in EDCF. However, control and management of the backoff-based priority scheme are still challenging problems. We have analysed the impacts of backoff and Inter-frame Space (IFS) parameters of EDCF on saturation throughput and service differentiation. A centralised QoS management and control scheme is proposed. The configuration of backoff parameters and admission control are studied in the management scheme. The special role of access point (AP) and the impact of traffic load are also considered in the scheme. The backoff parameters are adaptively re-configured to increase the levels of bandwidth guarantee and fairness on sharing bandwidth. The proposed management scheme is evaluated by OPNET. Simulation results show the effectiveness of the analytical model based admission control scheme. ©2005 IEEE.

Evaluation of low vision services on the quality of life of individuals with age-related macular degeneration

Background: Age-related macular degeneration (ARMD) is a major cause of irreversible visual loss in the elderly and a significant threat to their quality of life. Although low vision services often improve the functional outcomes of individuals with macular disease, it remains unclear whether or not they have any impact on quality of life. The principal aim of this study was to determine the effect of a hospital-based low vision clinic on the quality of life of individuals with ARMD. Methods: Forty patients with ARMD attended the low vision clinic at Milton Keynes University Hospital. Quality of life was measured with the vision-specific Low Vision Quality of Life (LVQOL) questionnaire and the general health EuroQol (EQ-5D-5L) questionnaire. Measures were completed at baseline (time zero, T0), and at three- (T3) and six-month (T6) follow-up visits. Results: The near visual acuity of individuals attending the low vision clinic for the first time improved significantly between visits T0 and T3 (p=0.005), reflecting the practiced use of their newly-dispensed low vision aids. As expected, there was no significant change in near acuity over this time period for existing patients. For both new and existing patients, a significant increase in LVQOL score was evident between visits T0 and T3, with a further significant improvement between T3 and T6. Similarly, there was a significant decrease in EQ-5D-5L questionnaire scores between visits T0 and T6. Conclusions: The higher LVQOL scores obtained at the end of the study period (T6) provide evidence that low vision services at Milton Keynes University Hospital served to improve patient quality of life. The reduction in EQ-5D-5L scores over the same time period suggests that low vision services also provide for an improvement in general health-related quality of life. Impact: The findings support the cause of low vision services to improve not only the vision and functional outcomes of individuals with macular disease but also their quality of life. Moreover, the findings suggest that a more efficient allocation of resources at low vision clinics may be possible through the standardisation of patient follow-up frequency.