Time-limited Service Research Articles

Social Innovation and Social Work: A Case Study of the Early Intervention Support Service

AbstractIn a national and international context where there is a concern about the effectiveness of social care services for children and families to address chronic, enduring social problems and where there are finite resources available, the concept of social innovation in social work policy and practice to address need in new ways is receiving increased attention. Whilst an attractive term, social innovation in child and family services is not without its challenges in terms of conceptualisation, operationalisation, implementation and evidencing impact. This article reports on the development and evaluation of the Early Intervention Support Service (EISS), a newly designed family support service in Northern Ireland set up as part of a government-supported innovation and transformation programme that aims to deliver a voluntary, targeted, flexible and time-limited service to families experiencing emergent problems. Using the EISS as a case study, the challenges, benefits in terms of addressing policy imperatives and future direction of social innovation in social work practice are reflected upon.

Analysis of Queueing System with Non-Preemptive Time Limited Service and Impatient Customers

We consider a single-server queueing system with server vacations as the important component of the polling queueing model of a real-world system. Period of continuous operation of the server (the maximum server attendance time) is restricted, but the service of a customer cannot be interrupted when this period expires. Such features are inherent for many real-world systems with resource sharing. We assume that the customers arrival is described by the Markovian Arrival Process and service, vacation and maximum server attendance times have a phase-type distribution. We derive the stationary distributions of the system states and waiting time. Taking in mind the necessity of further application of the results to modeling the polling queueing systems, the distribution of the server visiting time is derived. Extensive numerical results are presented. They highlight that an account of the coefficient of variation of vacation and maximum attendance time is very important for exact evaluation of the key performance measures of the system, while only the results for the coefficient of variation equal to zero or one are known in the literature. Impact of the possible customers impatience, which is intuitively important because the time-limited service is considered, is confirmed by the results of the numerical experiments. Optimization problem of matching the durations of vacation and maximum attendance time is considered.

Stability of a two-queue cyclic polling system with BMAPs under gated service and state-dependent time-limited service disciplines

The stability of a cyclic polling system, with a single server and two infinite-buffer queues, is considered. Customers arrive at the two queues according to independent batch Markovian arrival processes. The first queue is served according to the gated service discipline, and the second queue is served according to a state-dependent time-limited service discipline with the preemptive repeat-different property. The state dependence is that, during each cycle, the predetermined limited time of the server's visit to the second queue depends on the queue length of the first queue at the instant when the server last departed from the first queue. The mean of the predetermined limited time for the second queue either decreases or remains the same as the queue length of the first queue increases. Due to the two service disciplines, the customers in the first queue have higher service priority than the ones in the second queue, and the service fairness of the customers with different service priority levels is also considered. In addition, the switchover times for the server traveling between the two queues are considered, and their means are both positive as well as finite. First, based on two embedded Markov chains at the cycle beginning instants, the sufficient and necessary condition for the stability of the cyclic polling system is obtained. Then, the calculation methods for the variables related to the stability condition are given. Finally, the influence of some parameters on the stability condition of the cyclic polling system is analyzed. The results are useful for engineers not only checking whether the given cyclic polling system is stable, but also adjusting some parameters to make the system satisfy some requirements under the condition that the system is stable.

Access to opportunities for bilingualism for individuals with developmental disabilities: Key informant interviews

The purpose of this article is to describe the results of a thematic analysis of 79 semi-structured interviews collected at six research sites in four countries in relation to the inclusion and exclusion of students with developmental disabilities (DD) in and from special education and bilingual opportunities. The participants were individuals with expertise either in special needs and/or language education to support bilingualism (e.g., second language (L2) instruction), who served as key informants about service delivery and/or policy in these areas. Six themes emerged as salient during the analysis: we include all kids, special needs drives it, time/scheduling conflicts, IEP/IPP/statement drives it, it’s up to the parents, and service availability. The results suggested that access to language programs and services is limited for children with DD, even though participants at all sites reported adherence to a philosophy of inclusion. A priority on special education services over language services was identified, as well as barriers to providing children with DD access to programs and services to support bilingual development. Some of these barriers included time and scheduling conflicts and limited service availability. Additionally, the role of parents in decision making was affirmed, although, in contrast to special education services, decision-making about participation or exemption from language programs was typically left up to the parents. Overall, the results suggest a need for greater attention to providing supports for both first (L1) and L2 language development for bilingual children with DD and greater access to available language programs.

Transitional Care After Hospitalization for Acute Stroke or Myocardial Infarction

Transitional care is a time-limited service to prevent discontinuous care and adverse outcomes, including rehospitalization. To describe transitional care interventions and evidence of benefit or harm in patients hospitalized for acute stroke or myocardial infarction (MI). Cumulative Index to Nursing and Allied Health Literature, MEDLINE, Cochrane Database of Systematic Reviews, and EMBASE, supplemented with manual searches of reference lists of relevant studies and review articles (January 2000 to March 2012). 6 reviewers screened 5857 citations to identify English-language reports of trials or observational studies that compared transitional care with usual care among adults hospitalized for stroke or MI and that reported patient, caregiver, process, or systems outcomes within 1 year of hospital discharge. Data on study design, quality, population, intervention characteristics, and patient- and system-level outcomes were extracted by 3 reviewers and confirmed by 1 additional reviewer. 62 articles representing 44 studies of transitional care for either acute stroke (27 studies) or MI (17 studies). Four intervention types were studied: hospital-initiated support (n = 14), patient and family education (n = 7), community-based support (n = 20), and chronic disease management (n = 3). Most studies (68%) were of fair quality. Overall, moderate-strength evidence showed that hospital-initiated support reduced length of stay for patients who had a stroke, and low-strength evidence showed that it reduced mortality for patients who had an MI. Evidence about benefits of other interventions and harms from transitional care services was insufficient. Few studies had high-quality research designs. The usual care comparator was often poorly defined. Applicability to U.S. clinical practice was limited; only 6 studies were conducted in the United States. Available evidence shows that hospital-initiated transitional care can improve some outcomes in adults hospitalized for stroke or MI. Finding additional transitional care interventions that improve functional outcomes and prevent rehospitalizations and adverse events is a high priority for the growing population of patients who have an MI or a stroke. Agency for Healthcare Research and Quality.

The NECVN PIN-T study: A time-limited service development programme in stroke

The North East Cardiovascular Network (NECVN) Psychological Intervention by Nurse/Therapist (PIN-T) study was conducted over a 12-month period. The primary aim was to improve the assessment of psychological problems post-stroke, for patients in the Gateshead locality. In line with the NICE guidelines for stroke, the aim was to conduct standardised assessments for both mood and cognition for all patients within six weeks post-stroke. Additional aims were to improve the psychological knowledge of the inpatient team and to improve the appropriateness of referrals to the Clinical Psychology service.A high proportion of patients were inappropriate for assessment within the time-frame (49 per cent) due to factors such as severity of physical health problems. Of those who were deemed appropriate to assess, the number of stroke admissions who received a standardised cognitive assessment within six-weeks post-stroke was 75 per cent, with 71 per cent for standardised mood assessments. Subsequently, there was a 300 per cent increase in referrals to the Older Person’s Psychology department.

Time-limited polling systems with batch arrivals and phase-type service times

In this paper, we develop a general framework to analyze polling systems with either the autonomous-server or the time-limited service discipline. According to the autonomous-server discipline, the server continues servicing a queue for a certain period of time. According to the time-limited service discipline, the server continues servicing a queue for a certain period of time or until the queue becomes empty, whichever occurs first. We consider Poisson batch arrivals and phase-type service times. It is known that these disciplines do not satisfy the well-known branching property in polling systems. Therefore, hardly any exact results exist in the literature. Our strategy is to apply an iterative scheme that is based on relating in closed-form the joint queue-lengths at the beginning and the end of a server visit to a queue. These kernel relations are derived using the theory of absorbing Markov chains.

Queuing Analysis of HCCA for Multi-Rate Wireless LANs with Truncated ARQ Protocol

In this paper, a novel queuing analytical framework is introduced to analyze the performance of the HCF controlled channel access designed as a medium access mechanism in wireless local area networks. The queuing model defines a multi-rate medium using adaptive modulation and coding which is a key point in wireless networks to increase effective transmission rate. Based on a MAP (Markovian arrival process)/PH (phase type)/1 queue with vacation and time-limited service, the model considers a limited node buffer and non-ideal channel with the automatic repeat request protocol. Using a MAP for traffic arrival process and PH distribution for packet service process, the inclusion of the non-transmission and vacation processes makes our analysis very general and comprehensive to support various types of practical traffic streams. To formulate the model, the powerful matrix-geometric method is employed, and the mutual impacts of some parameters in the MAC and the PHY layers are then evaluated to improve system performance. Finally, optimization of parameter settings to maximize throughput is discussed.

Time-Limited Service Alternatives: Reply to Commentators

The commentators' responses to the viability of open groups using Therapeutic Enactment (TE) in a university setting are important. This reply addresses four main points: (a) single versus multiple sessions; (b) principles of brief therapy; (c) issues around training for group leaders; and (d) further research. The author agrees with commentators that we need to take steps toward studying the therapeutic effects of our model for participants and suggests ways of moving forward with the work.

A Response to “Time-Limited Service Alternatives: Using Therapeutic Enactment in Open Group Therapy”: A Dramatic Effort to Redefine Short-Term and Time-Limited Services

Therapeutic Enactment (TE) groups, as presented in the article, “Time-Limited Service Alternatives: Using Therapeutic Enactment in Open Group Therapy,” offer an exciting and promising addition to the types of groups traditionally offered in university counseling centers. The brevity of member participation, the lack of empirical evidence of effectiveness, and the significant level of leader competency required for effective facilitation of the groups are notable limitations that deserve attention.

Time-Limited Service Alternatives: Using Therapeutic Enactment in Open Group Therapy

The current college counseling literature reports increases in the number of requests for counseling services on campuses, as well as increases in the complexity and severity of client problems. These changes have lead counselors to search for alternative means of providing effective and efficient therapeutic assistance to students in need. In this article, we introduce an innovative group counseling approach that combines the open group therapy format with therapeutic enactment (TE) intervention techniques for students with psychosocial issues. The approach is introduced, a group example illustrating the method is presented, and important ethical and clinical considerations are discussed.

A Response to “Time-Limited Service Alternatives: Using Therapeutic Enactment in Open Group Therapy”

This article offers comments on the Keats and Sabharwal article, “Time-Limited Service Alternatives: Using Therapeutic Enactment in Open Group Ttherapy,” including the rationale for the approach, its conceptual base, the group process and ethical issues. Suggestions for further research on this approach are presented, including examination of its application to specific populations like Native college students.

Analysis of a time-limited service priority queueing system with exponential timer and server vacations

We consider a multi-class priority queueing system with a non-preemptive time-limited service controlled by an exponential timer and multiple (or single) vacations. By reducing the service discipline to the Bernoulli schedule, we obtain an expression for the Laplace-Stieltjes transform (LST) of the waiting time distribution via an iteration procedure, and a recursive scheme to calculate the first two moments. It is noted that we have to select embedded Markov points based on the service beginning epochs instead of the service completion epochs adopted for most of M/G/1 queueing analyses. Through the queue-length analysis, we obtain a decomposition form for the LST of the waiting time in each queue having the exhaustive service.

A pseudoconservation law for a time-limited service polling system with structured batch poisson arrivals

We consider a cyclic-service queueing system (polling system) with time-limited service, in which the length of a service period for each queue is controlled by a timer, i.e., the server serves customers until the timer expires or the queue becomes empty, whichever occurs first, and then proceeds to the next queue. The customer whose service is interrupted due to the timer expiration is attended according to the nonpreemptive service discipline. For the cyclic-service system with structured batch Poisson arrivals ( M x/G /1) and an exponential timer, we derive a pseudoconservation law and an exact mean waiting time formula for the symmetric system.

Level-crossing approach to a time-limited service system with two types of vacations

We consider an M X / G / 1 queue with nonpreemptive time-limited service and timer and exhaustive vacations. We analyze the waiting time distribution in this multiple vacation model by applying the level-crossing method to a workload process with two types of vacations.

Study on the modeling of timed-token protocol

The study on the modeling of timed-token protocol (TTP) in metropolitan area network is presented in this paper. The classification of queueing models of TTP is given, and the mathematical analysis as well as numerical emulation for one of the queueing models i.e. L/G/1 [Intermittent, Station priority, TTP, Time-limited service] are presented.

Waiting time analysis for a queueing system with time‐limited service and exponential timer

AbstractWe consider a single‐queue with exhaustive or gated time‐limited services and server vacations, in which the length of each service period at the queue is controlled by a timer, i.e., the server serves customers until the timer expires or the queue becomes empty, whichever occurs first, and then takes vacations. The customer whose service is interrupted due to the timer expiration may be attended according to nonpreemptive or preemptive service disciplines. For the M/G/1 exhaustive/gated time‐limited service queueing system with an exponential timer and four typical preemptive/nonpreemptive service disciplines, we derive the Laplace—Stieltjes transforms and the moment formulas for waiting times and sojourn times through a unified approach, and provide some new results for these time‐limited service disciplines. © John Wiley & Sons, Inc. Naval Research Logistics 48: 638–651, 2001.

The Deployment of Information Technology in an International Rural Health Care Project

SUMMARY This paper presents a case study of the utilization of Information Technology (IT) in a cataract surgery eye camp held outside a remote village in India. Detailed here are the organizational and technological context of the project, the steps taken in the development and deployment of a patient medical database, the data collection procedures employed during the eye camp, and the resultant information products of these endeavors. Discussed are the implications for the application of IT in the documentation and evaluation of time-limited health and social service delivery projects.

Analysis of a discrete time table polling system with MAP input and time-limited service discipline

An iterative procedure based on the MAP/PH/1 and MAP/PH/1/K queues with vacation is presented for approximating the performance measures of a table polling system. Each queue has a time limit after which it relinquishes the server. This is formally known as the token holding time (THT) in IEEE 802.5 and IEEE 802.4 standards. The polling table can be tailored such that queues with limits on the cycle time are visited more frequently, thus, limiting the delays for real time applications. The visit period and vacation period distributions were obtained based on the properties of the discrete phase distribution. Several examples are presented and they show that the algorithm converges fairly fast and gives reasonable results.

Analysis of a time-limited polling system

In this paper, we consider a cyclic polling system in which arrivals are governed by the Markovian arrival process. Each queue is visited according to the exhaustive time-limited service discipline to coincide with IEEE 802.5 and 802.4 standards. Using the decomposition approach, each queue is analyzed as a single server queue with vacation. By exploiting the properties of the discrete time phase distribution we construct the vacation period from the visit period of the other queues in the polling system. Using an iterative procedure we were able to compute the queue length distribution and the average waiting time for polling systems with finite capacity (or infinite capacity) in all queues. Comparison of the mean waiting time with simulation results shows that the proposed models give reasonable results.