Uniform Service Research Articles

A note on joining strategies for two queues in parallel

The present chapter deals initially with M/ (M+U)/1)2. By allowing one of the two servers to have a continuous uniform service time distribution, we make our model much realistic. We consider various strategies for a smart customer. Finally an interesting generalization of it in the form M/((H2+U) /2)2has been presented, where (H2+U) is a mixture of two distributions, one hyper-gamma and second uniform continuous so that the customer gets faster and better service.

Clustering and sharing incentives in BitTorrent systems

Peer-to-peer protocols play an increasingly instrumental role in Internet content distribution. It is therefore important to gain a complete understanding of how these protocols behave in practice and how their operating parameters affect overall system performance. This paper presents the first detailed experimental investigation of the peer selection strategy in the popular BitTorrent protocol. By observing more than 40 nodes in instrumented private torrents, we validate three protocol properties that, though believed to hold, have not been previously demonstrated experimentally: the clustering of similar-bandwidth peers, the effectiveness of BitTorrent's sharing incentives, and the peers' high uplink utilization. In addition, we observe that BitTorrent's modified choking algorithmin seed state provides uniform service to all peers, and that an underprovisioned initial seed leads to absence of peer clustering and less effective sharing incentives. Based on our results, we provide guidelines for seed provisioning by content providers, and discuss a tracker protocol extension that addresses an identified limitation of the protocol.

Global strategies in the international hotel industry

A two stage qualitative research methodology is used to evaluate the forces driving the adoption of global strategies in the hotel industry and the strategic response of international hotel chains to those “drivers”. Information gathered from industry experts is used to develop a set of hypotheses which are then tested against evidence provided by interviews with senior executives and other data.The results indicate that global strategy is most influenced by market factors, other drivers having much less influence. Cost drivers are constrained by limited economies of scale and standardization opportunities. Globalization is most marked in the thrust for a broad geographic presence in key overseas markets, the pursuit of global branding, positioning and uniform service standards. At the same time, customers expect “responsive” policies in areas such as facilities and services provided. Opportunities for greater integration and concentration of “back-office” functions, where information-based systems allow for cost economies and enhanced coordination, often remain relatively unexploited, primarily due to institutionalized management practice and control constraints.

CAR: a low latency video-on-demand broadcasting scheme for heterogeneous receivers

As different types of wireless networks are converging into an all-IP network, i.e., the Internet, it can be expected that in the near future video-on-demand (VoD) will be widely applied to many interesting services, and users can access these services using heterogeneous terminals via heterogeneous wired/wireless access networks. Many periodic broadcasting protocols have been proposed to reduce the implementation cost of VoD systems. However, most of the protocols assumed homogeneity for user terminals, while in practice, user terminals are usually quite different in their processing power, buffer space, and power. To address this problem, a few periodic broadcasting protocols providing the same video quality for all heterogeneous clients have been proposed recently. In this paper, we proposed a novel heterogeneous VoD broadcasting technique called Catch and Rest (CAR) to accommodate bandwidth heterogeneity without sacrificing user video quality. Then, we provide mathematic analysis to calculate the client bandwidth and buffer space requirements of CAR. Finally, we present our performance evaluation results for CAR. Our results show that under the same system resources (i.e., server and network bandwidth), CAR provides more uniform and acceptable service latency for all heterogeneous clients compared to previous works

Chapter 4. Lending

Lending to other libraries completes the ILL cycle. Chapter 4 includes a sample “daily timeline” of the activities of the lending section of an ILL department. Additional detailed information on managing the lending workflow is provided along with a sample lending policy document which lending libraries can use to provide uniform service to borrowing libraries.

Intelligent client for integrating bioinformatics services

In addition to existing bioinformatics software, a lot of new tools are being developed world wide to supply services for an ever growing, widely dispersed and heterogeneous collection of biological data. The integration of these resources under a common platform is a challenging task. To this end, several groups are developing integration technologies, in which services are usually registered in some sort of catalogue to allow novel discovering and accessing mechanisms to be implemented. However, each service demands specific interfaces to accommodate their parameters and it is a complicated task linking the different service inputs and outputs to solve a biological problem. In this work we address the design and implementation of a versatile web client to access BioMOBY compatible services (a system by which a client can interact with multiple sources of biological data regardless of the underlying format or schema) using the service description stored in the BioMOBY catalogue. The automatic interface generator significantly reduces developing time and produces uniform service access mechanisms. The design and proof of concept (for such a client) including the generic interface generator have been developed and implemented in the National Institute for Bioinformatics in Spain. The INB (National Institute for Bioinformatics, Spain) platform is available at www.inab.org/MOWServ

Feasibility study of a XML-based software environment to manage data acquisition hardware devices

A Software environment to describe configuration, control and test systems for data acquisition hardware devices is presented. The design follows a model that enforces a comprehensive use of an extensible markup language (XML) syntax to describe both the code and associated data. A feasibility study of this software, carried out for the CMS experiment at CERN, is also presented. This is based on a number of standalone applications for different hardware modules, and the design of a hardware management system to remotely access to these heterogeneous subsystems through a uniform web service interface.

An observational study to identify predictors of acute stress disorder and depressive symptoms in adult female victims of sexual assault

Study objectives: The objective of this prospective study is to determine what psychosocial characteristics affect outcomes at 1 month in female victims of sexual assault. The main outcomes are the presence of acute stress disorder as measured by the Impact of Events Scale and the presence of depressive symptoms measured by the Center for Epidemiologic Studies Depression Scale (CES-D). Additional outcomes are the victim's satisfaction with care received in the emergency department (ED) as measured by the Satisfaction scale and patient follow-up. Our hypotheses are as follows. Patients with lower socioeconomic status, history of being a victim of a violent crime, and less social support will have more depressive symptoms and an increased incidence of acute stress disorder 1 month after a sexual assault. Greater satisfaction with ED services will result in increased compliance with follow-up and decreased symptoms of depression and inhibition. Centers that have a designated rape response team will have increased compliance with nationally recommended guidelines. Methods: Patients were recruited from 2 urban centers, 1 with a regional Sexual Assault Response Team with certified health care providers, advocates, and law enforcement, and 1 with 3 trained forensic examiners. Female victims who were 18 years or older and presenting to the ED for evaluation after a sexual assault were eligible for the study. Baseline demographic data, clinical data, and services received in the ED were documented. Social support was measured by administering the Duke Social Support and Stress Scale, and patient satisfaction was determined by the Satisfaction Scale. One month later, 2 instruments were administered to determine the presence of acute stress disorder, the Impact of Events Scale, a 15-item scale that measures symptoms of avoidance and inhibition, and the CES-D scale, a 20-item scale that measures the presence of depressive symptoms. Results: Fourteen patients from site 1 and 36 patients from site 2 were enrolled. The average age was 29 years. The racial distribution was 80% black, 13% white, and the remaining 7% Asian or Latino; 61% of the patients had at least 1 child, 78% were single mothers, and 55% of the patients were employed. Forty-eight percent of patients had scores of 16 or higher, consistent with presence of depressive symptoms. Patients with symptoms of depression had less social support. However, patients who were less-educated single mothers and had lower incomes were less likely to be depressed. For acute stress disorder, 10% of the patients scored greater than 26 on the inhibition subscale, and 14% of patients scored greater than 26 on the avoidance subscale. Our analysis found that the center with a sexual assault response team had higher compliance with guidelines (100% versus 63%) and increased patient satisfaction (87.4% versus 66%) and follow-up (75% versus 14%). Conclusion: The results of this study provide preliminary analysis that by identifying factors that predispose to acute stress disorder and depressive symptoms, an intervention can be developed to improve patient outcome. Health care providers should generate guidelines to provide a uniform service of care in the ED that results in increased patient satisfaction that can be replicated and implemented nationally.

Web100

TCP has become the dominant protocol for all network data transport because it presents a simple uniform data delivery service which is sufficient for most applications over all types of lower network layers. By its very nature, TCP's adaption and retransmission strategies hide all of the details of the lower layers from the application. For example the only symptom of spurious packet loss (or nearly any other network problem) is longer elapsed time and lower performance.This information hiding is fundamentally important to the growth of the Internet because it decouples the evolution of applications from the evolution of link layers. However it also hides valuable information from researchers, educators, network administrators, and other people who would benefit from insight into the inner workings of TCP and the lower layers.In this paper, we present an architecture and infrastructure that provides for per-connection TCP instrumentation to expose otherwise hidden protocol events. We show examples how the infrastructure can be used in support of research, education and advanced network diagnostic tools.Our work was motivated by the observation that since about 1985 network data rates for typical novice network users have fallen by about three orders of magnitude behind expert users (who have kept up with Moore's Law). We use the term "Wizard Gap" to describe this phenomenon. The Web100 and Net100 projects were formed as one step in closing the Wizard Gap.

Developing early intervention services in the NHS: a survey to guide workforce and training needs

Aims and Method We conducted a questionnaire study to establish the incidence, specialist staff availability, treatment provision and socio-demographic profile of patients with first-episode psychosis referred to all adult and child and adolescent community mental health teams in south and west London. Results All 39 teams completed the questionnaire, identifying 295 cases of first-episode psychosis (annual incidence 21/100 000/year) referred in the year 2000. Teams manage to engage most patients with first-episode psychosis. A total of 73% of cases of first-episode psychosis were on some form of Care Programme Approach. However, many teams did not have adequately trained staff to provide psychosocial interventions. Even where such staff were available, care was focused mainly on monitoring medication and risk assessment, with only half the teams providing psycho-educational programmes and only a quarter offering individual cognitive–behavioural therapy to those with first-episode psychosis. Clinical Implications Establishing early intervention services nationwide will require significant new resources, including specialist trained staff, which could prove difficult to provide in inner-city areas. Rather than a single, uniform service model, several models of early intervention services based on locally determined need might be more realistic and appropriate, and also allow research into their relative efficacy.

Developing early intervention services in the NHS: a survey to guide workforce and training needs

Aims and MethodWe conducted a questionnaire study to establish the incidence, specialist staff availability, treatment provision and socio-demographic profile of patients with first-episode psychosis referred to all adult and child and adolescent community mental health teams in south and west London.ResultsAll 39 teams completed the questionnaire, identifying 295 cases of first-episode psychosis (annual incidence 21/100 000/year) referred in the year 2000. Teams manage to engage most patients with first-episode psychosis. A total of 73% of cases of first-episode psychosis were on some form of Care Programme Approach. However, many teams did not have adequately trained staff to provide psychosocial interventions. Even where such staff were available, care was focused mainly on monitoring medication and risk assessment, with only half the teams providing psycho-educational programmes and only a quarter offering individual cognitive–behavioural therapy to those with first-episode psychosis.Clinical ImplicationsEstablishing early intervention services nationwide will require significant new resources, including specialist trained staff, which could prove difficult to provide in inner-city areas. Rather than a single, uniform service model, several models of early intervention services based on locally determined need might be more realistic and appropriate, and also allow research into their relative efficacy.

Diabetes care in childhood and adolescence

The presentation of diabetes in young people has changed significantly over recent years. Not only has there been a rising incidence of Type 1 diabetes, especially in young children, but also there is an increasing recognition of Type 2 diabetes. Young people are also increasingly being diagnosed with genetic defects of B-cell function and with diabetes in association with cystic fibrosis and other chronic diseases. There have also been significant changes in the pattern of paediatric diabetes care. This is increasingly being provided by a specialized paediatric multidisciplinary team in each health district working to agreed national standards. Despite improvements, diabetes control is still suboptimal with a high incidence of complications being reported in young adults. The challenge over the next few years is the provision of a uniform, equitable and first class paediatric service throughout the UK together with the introduction of new approaches to care, aiming to improve individual diabetic control and reduce long-term complications. Increased collaboration with adult colleagues is needed to enable the transition of care in adolescence to a service that young adults perceive to meet their needs, encourage their attendance and improve their diabetes control and quality of life. A national paediatric diabetes register together with regular audit will encourage these objectives.

The impact of an assisted conception unit on the workload of a general gynaecology unit.

The burden placed on a hospital by the presence of an assisted conception unit has been emphasised only in terms of its impact on neonatal services. This paper examines the previously neglected subject of the gynaecological workload generated by a tertiary fertility centre that provides treatments by assisted conception. As many IVF units operate independently this additional workload may not be appreciated. It has, however, significant practical and financial implications for neighbouring hospitals and trusts. This is of particular relevance in view of the move towards more uniform health service funding of assisted conception throughout the United Kingdom.

Implementing Guidelines for Interdisciplinary Care of Low Back Pain: A Critical Role for Pre-Appointment Management of Specialty Referrals

Improving health care will require more effective guideline implementation and redesign of delivery processes and systems. Patient referral for specialty care is a key component of health system function that needs to be improved. Low back pain care is a widely documented example of the need for improvement. An interdisciplinary systemwide back pain program was developed using process improvement methods. Proactively managing referrals for specialty care-a departure from traditional referral processes-played a critical role in implementing the program. Program components included guidelines for care, defined provider roles, uniform service coding, provider and patient education, pre-appointment specialty referral management, and monitoring of management processes. To evaluate program performance, system back pain visits were compared before, during, and after implementation of referral management. A case series study was performed on 581 consecutive patients with low back pain or lumbar radiculopathy referred for consultative spine care between April 1998 and March 1999. A shift of care was accomplished for acute back pain from spine orthopedists to primary physicians and for chronic back pain from spine orthopedists to medical specialists. More than 95% of initial assignments were accurate. Seventy-six percent of surveyed chronic back pain patients improved, and 90% were highly satisfied with the referral management process. This program has saved an estimated $400,000 per year in manpower cost and has reduced specialty service billings by 20%. Pre-appointment referral management offers an approach for improving guideline implementation, access to specialty services, and the effectiveness of care for complex health problems. It deserves broader study and adoption.

Clinical Characteristics of Youths With Substance Use Problems and Implications for Residential Treatment

Despite high rates of dual diagnosis among children and adolescents and evidence that adults with coexisting substance use disorders require specialized services, many children are placed in residential settings and are offered uniform service packages regardless of their individual clinical profiles. The authors examined the rate of substance use problems in a sample of children and adolescents with severe emotional or behavioral disturbances who were in residential treatment. Differences in clinical characteristics and placement outcomes between children with and without coexisting substance use disorders were evaluated. This retrospective study analyzed clinical data obtained by chart review using the Child Severity of Psychiatric Illness, a rating scale for symptom severity. The study subjects were 564 children and adolescents in residential treatment and state custody in Florida and Illinois who had serious emotional or behavioral disturbances. Twenty-six percent of boys and 37 percent of girls had substance use problems in addition to serious emotional or behavioral disturbances. Residents with co-occurring substance use disorders were significantly more likely than those with serious emotional or behavioral disturbances only to be at risk for suicide, elopement from residential placement, delinquent behavior, and institutional discharge placement. Children and adolescents with coexisting substance use problems require individualized service packages to address their greater need for supervision and higher rate of risk behaviors and to facilitate community discharge placements.

An authorization framework for metacomputing applications

To span administrative boundaries, metacomputing systems require the integration of strong authentication and authorization methods. The problem is complicated because different components of the system may have different security policies. This paper presents a distributed model for authorization that we have integrated with the Prospero Resource Manager, a metacomputing resource allocation system developed at USC. The integration of authorization with PRM was accomplished through the specification of a policy language and the use of a Generic Authorization and Access-control API (GAA API). The language supports the specification of diverse authorization policies including ACLs, capabilities and lattice-based access controls. The GAA API provides a uniform authorization service interface for facilitating access control decisions and requesting authorization information about a particular resource. We describe a prototype of our system.

INDUSTRY AND PRACTICE

Electronic commerce is a generic term that encompasses numerous information technologies and services used to improve business practices ranging from customer service to inter-corporation coordination. One of the most common instances of electronic commerce is the exchange of goods and services over the Internet but there are many other forms of electronic commerce such as controlled electronic purchase or virtual malls. Electronic commerce is not a futuristic dream; it is happening now with many wellestablished success stories. However, the electronic commerce services that are established so far are still far from being mature. There is no real integration of the underlying technologies, and the provided services lack many important but also more challenging features. Electronic commerce is not a single uniform service, but rather characterized by a wide range of services and operations, including: establishment of initial contacts, suppliers search and negotiation; exchange of information; sales; pre- and post-sales support; electronic payment; distribution logistics; establishment and coordination of virtual enterprises; shared business processes; etc. In all of its forms, electronic commerce makes use of information technologies from very different areas: databases, transaction processing, interoperability of heterogeneous information resources, intelligent agents, multimedia systems, security and workflow systems. In this paper, the current-state-of the art as well as research issues related with enabling information technologies for electronic commerce are briefly discussed.

A critical review of the role of neonatal hearing screening in the detection of congenital hearing impairment.

This review was commissioned because of the increasing doubt about the ability of existing screening programmes (mainly the health visitor distraction test (HVDT) at 7-8 months) to identify children with congenital hearing impairment, and technological advances which have made neonatal hearing screening an alternative option. To review the available literature on the screening of permanent childhood hearing impairment. To provide commissioners and providers of health care with information about how to deliver a more uniform service, better outcomes, and more cost-effective screening. To identify areas for further research and service development. The research involved a review of the available published and unpublished literature, and a comprehensive survey of current pre-school hearing screening provision in the UK coupled with a health economics study of hearing screening costs. The research also included a number of focus groups and visits to key centres in the UK and North America. EPIDEMIOLOGY OF PERMANENT CHILDHOOD HEARING IMPAIRMENT: There are approximately 840 children a year born in the UK with significant permanent hearing impairment likely to affect their own and their family's quality of life. Present services will miss about 400 of these children by 1 1/2 years of age, and about 200 of these children by 3 1/2 years of age. Such late identification of hearing impairment greatly reduces the responsiveness of the services for individual children. Hearing-impaired children identified late are at risk of substantial delay in their acquisition of language and communication skills, with consequent longer-term risk to education achievement, mental health and quality of life. Theoretical arguments on neural development support the limited evidence here for the increased benefit for child and family associated with very early identification. In general, parents and professionals want very early identification, which, if implemented properly, does not cause undue anxiety. The survey of current practice indicated a major problem with poor information systems. This problem was further highlighted as a major concern by the multi-disciplinary focus groups. Practice varies. There are two District-wide programmes in which all newborn babies are neonatally screened, a large number of ad hoc programmes for neonatal screening of 'at-risk' babies, a variety of early surveillance programmes, and widespread use of the HVDT. Intervention and habilitation for the majority of those screened neonatally is routinely undertaken within 6 months of birth. For those screened only by the health visitor, identification was on average at about 26 months of age with intervention at about 32 months on average. (ABSTRACT TRUNCATED)

Heavy Traffic Asymptotics for a Gated, Infinite-Server Queue with Uniform Service Times

The authors consider a gated, infinite-server queue with uniform service times. Using perturbation methods they construct asymptotic formulas for the probability that k customers are served during a stage. The authors assume that the Poisson arrival rate $\lambda $ is large and consider the two space scales $k = \lambda + O( {\sqrt \lambda } )$ and$k = O( \lambda )$. This leads to very simple approximations to the probability distribution, which are shown to be in excellent agreement with numerical results.

A fuzzy sets modelling approach for ergonomic workload stress analysis

The Ergonomic Workload Stress Index (EWSI) model was developed to predict the existence and level of the ergonomic workload stress via the concept of the fuzzy sets theory. The linguistic values (e.g., “heavy”, “uncomfortable”, etc.) of the tasks and workplace variables (e.g., physical job demand, postural, environmental stressors, etc.) which have most influential factors on stress were defined. The computerized system was developed to investigate the inappropriate tasks and workplaces and to suggest alternative solutions to problems. The EWSI model was implemented in three industrial environments (i.e., grocery store distribution warehouse, drilling tools manufacturer, and linen and uniform rental service industry) from the epidemiological and physiological viewpoints to validate the model. The following results were obtained from the validation process: (1) a positive relationship between the EWSI value and the severity of injury and illness rate (coefficient of correlation = 0.716, 0.917, and 0.854 for the three different industries); (2) a close linear relationship between the EWSI value and heart rate (coefficient of correlation = 0.845); and (3) a close linear relationship between the EWSI value and blood pressure (coefficient of correlation = 0.804 and 0.775 for the systotic and diastolic blood pressure, respectively).