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Start Times (start + time)
Selected AbstractsJust in Time: Improving Scheduled Cesarean Start TimesJOURNAL OF OBSTETRIC, GYNECOLOGIC & NEONATAL NURSING, Issue 2010Professional Issues No abstract is available for this article. [source] Operative Start Times and Complications After Liver TransplantationAMERICAN JOURNAL OF TRANSPLANTATION, Issue 8 2010B. E. Lonze The recent national focus on patient safety has led to a re-examination of the risks and benefits of nighttime surgery. In liver transplantation, the hypothetical risks of nighttime operation must be weighed against either the well-established risks of prolonging cold ischemia or the potential risks of strategies to manipulate operative start times. A retrospective review was conducted of 578 liver transplants performed at a single institution between 1995 and 2008 to determine whether the incidence of postoperative complications correlated with operative start times. We hypothesized that no correlation would be observed between complication rates and operative start times. No consistent trends in relative risk of postoperative wound, vascular, biliary, or other complications were observed when eight 3-h time strata were compared. When two 12-h time strata (night, 3 p.m.,3 a.m., and day, 3 a.m.,3 p.m.) were compared, complications were not significantly different, but nighttime operations were longer in duration, and were associated a twofold greater risk of early death compared to daytime operations (adjusted OR 2.9, 95% CI 1.16,7.00, p = 0.023), though long-term survival did not differ significantly between the subgroups. This observation warrants further evaluation and underscores the need to explore and identify institution-specific practices that ensure safe operations regardless of time of day. [source] Resource reservations with fuzzy requestsCONCURRENCY AND COMPUTATION: PRACTICE & EXPERIENCE, Issue 13 2006T. Röblitz Abstract We present a scheme for reserving job resources with imprecise requests. Typical parameters such as the estimated runtime, the start time or the type or number of required CPUs need not be fixed at submission time but can be kept fuzzy in some aspects. Users may specify a list of preferences which guide the system in determining the best matching resources for the given job. Originally, the impetus for our work came from the need for efficient co-reservation mechanisms in the Grid where rigid constraints on multiple job components often make it difficult to find a feasible solution. Our method for handling fuzzy reservation requests gives the users more freedom to specify the requirements and it gives the Grid Reservation Service more flexibility to find optimal solutions. In the future, we will extend our methods to process co-reservations. We evaluated our algorithms with real workload traces from a large supercomputer site. The results indicate that our scheme greatly improves the flexibility of the solution process without having much affect on the overall workload of a site. From a user's perspective, only about 10% of the non-reservation jobs have a longer response time, and from a site administrator's view, the makespan of the original workload is extended by only 8% in the worst case. Copyright © 2006 John Wiley & Sons, Ltd. [source] Self evolution algorithm to minimize earliness and tardiness penalties with a common due date on a single machineIEEJ TRANSACTIONS ON ELECTRICAL AND ELECTRONIC ENGINEERING, Issue 6 2008Wei Weng Non-member Abstract Earliness and tardiness penalties are designed for such scheduling problems where the popular Just-In-Time (JIT) concept is considered to be of significant importance. In this paper, a self evolution (SE) algorithm is proposed to solve the problem of single-machine total earliness and tardiness penalties with a common due date. Up to now, no specific attention has been paid to straddling V-shaped schedules of such problems, which may be better than pure V-shaped schedules for the early due date cases; and no specific discussions have been made on the start time setting of the first job in a schedule. Therefore, in this research, efforts have been made on digging out the straddling V-shaped schedules, improving the efficiency of setting the start time of a schedule, and reducing the execution time. In addition, a new RHRM approach is proposed to create the initial solution for evolution, which helps in achieving the fast contingency of the algorithm. The performance of the proposed algorithm has been tested on 280 benchmark instances ranging from 10 to 1000 jobs from the OR Library, and the results show that the proposed SE algorithm delivers much higher efficiency in finding optimal or near-optimal solutions with both better results in total penalties and significant execution time reduction. Copyright © 2008 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc. [source] Centering the projection reconstruction trajectory: Reducing gradient delay errors,MAGNETIC RESONANCE IN MEDICINE, Issue 1 2003Dana C. Peters Abstract The projection reconstruction (PR) trajectory was investigated for the effect of gradient timing delays between the actual and requested start time of each physical gradient. Radial trajectories constructed with delayed gradients miss the center of k -space in an angularly dependent manner, causing effective echo times to vary with projection angle. The gradient timing delays were measured in phantoms, revealing delays on the x, y, and z gradients which differed by as much as 5 ,sec. Using this one-time calibration measurement, the trajectories were corrected for gradient delays by addition of compensatory gradient areas to the prephasers of the logical x and y readout gradients. Effective projection-to-projection echo time variability was reduced to less than 1 ,sec for all imaging orientations. Using corrected trajectories, artifacts were reduced in phantom images and in volunteer studies. This correction should potentiate greater clinical use of the PR trajectory. Magn Reson Med 50:1,6, 2003. Published 2003 Wiley-Liss, Inc. [source] Estimating time dependent O-D trip tables during peak periodsJOURNAL OF ADVANCED TRANSPORTATION, Issue 3 2000Srinivas S. Pulugurtha Intelligent transportation systems (ITS) have been used to alleviate congestion problems arising due to demand during peak periods. The success of ITS strategies relies heavily on two factors: 1) the ability to accurately estimate the temporal and spatial distribution of travel demand on the transportation network during peak periods, and, 2) providing real-time route guidance to users. This paper addresses the first factor. A model to estimate time dependent origin-destination (O-D) trip tables in urban areas during peak periods is proposed. The daily peak travel period is divided into several time slices to facilitate simulation and modeling. In urban areas, a majority of the trips during peak periods are work trips. For illustration purposes, only peak period work trips are considered in this paper. The proposed methodology is based on the arrival pattern of trips at a traffic analysis zone (TAZ) and the distribution of their travel times. The travel time matrix for the peak period, the O-D trip table for the peak period, and the number of trips expected to arrive at each TAZ at different work start times are inputs to the model. The model outputs are O-D trip tables for each time slice in the peak period. 1995 data for the Las Vegas metropolitan area are considered for testing and validating the model, and its application. The model is reasonably robust, but some lack of precision was observed. This is due to two possible reasons: 1) rounding-off, and, 2) low ratio of total number of trips to total number of O-D pair combinations. Hence, an attempt is made to study the effect of increasing this ratio on error estimates. The ratio is increased by multiplying each O-D pair trip element with a scaling factor. Better estimates were obtained. Computational issues involved with the simulation and modeling process are discussed. [source] Adolescents' Sleep Behaviors and Perceptions of SleepJOURNAL OF SCHOOL HEALTH, Issue 5 2009Heather Noland MEd ABSTRACT Background:, Sleep duration affects the health of children and adolescents. Shorter sleep durations have been associated with poorer academic performance, unintentional injuries, and obesity in adolescents. This study extends our understanding of how adolescents perceive and deal with their sleep issues. Methods:, General education classes were randomly selected from a convenience sample of three high schools in the Midwest. Three hundred eighty-four ninth- to twelfth-grade students (57%) completed a self-administered valid and reliable questionnaire on sleep behaviors and perceptions of sleep. Results:, Most respondents (91.9%) obtained inadequate sleep (, 9 hours) on most school nights of the week, with 10% reporting less than 6 hours of sleep each week night. The majority indicated that not getting enough sleep had the following effects on them: being more tired during the day (93.7%), having difficulty paying attention (83.6%), lower grades (60.8%), increase in stress (59.0%), and having difficulty getting along with others (57.7%). Some students reported engaging in harmful behaviors to help them sleep: taking sleeping pills (6.0%), smoking a cigarette to relax (5.7%), and drinking alcohol in the evening (2.9%). Students who received fewer hours of sleep were significantly more likely to report being stressed (p = .02) and were more likely to be overweight (p = .04). Conclusions:, Inadequate sleep time may be contributing to adolescent health problems such as increased stress and obesity. Findings indicate a need for sleep hygiene education for adolescents and their parents. A long-term solution to chronic sleep deprivation among high school students could include delaying high school start times, such as was done successfully in the Minneapolis Public School District. [source] Operative Start Times and Complications After Liver TransplantationAMERICAN JOURNAL OF TRANSPLANTATION, Issue 8 2010B. E. Lonze The recent national focus on patient safety has led to a re-examination of the risks and benefits of nighttime surgery. In liver transplantation, the hypothetical risks of nighttime operation must be weighed against either the well-established risks of prolonging cold ischemia or the potential risks of strategies to manipulate operative start times. A retrospective review was conducted of 578 liver transplants performed at a single institution between 1995 and 2008 to determine whether the incidence of postoperative complications correlated with operative start times. We hypothesized that no correlation would be observed between complication rates and operative start times. No consistent trends in relative risk of postoperative wound, vascular, biliary, or other complications were observed when eight 3-h time strata were compared. When two 12-h time strata (night, 3 p.m.,3 a.m., and day, 3 a.m.,3 p.m.) were compared, complications were not significantly different, but nighttime operations were longer in duration, and were associated a twofold greater risk of early death compared to daytime operations (adjusted OR 2.9, 95% CI 1.16,7.00, p = 0.023), though long-term survival did not differ significantly between the subgroups. This observation warrants further evaluation and underscores the need to explore and identify institution-specific practices that ensure safe operations regardless of time of day. [source] Audit of the utilization of time in an orthopaedic trauma theatreANZ JOURNAL OF SURGERY, Issue 4 2010Christopher L. Delaney Abstract Background:, The efficient use of operating theatres is important to ensure optimum cost,benefit for the hospital and to clear waiting lists. This audit uses the orthopaedic trauma theatre as a model to assess the theatre efficiency at our institution. Methods:, We performed a retrospective audit using data gathered from the operating theatre database at our institution. We considered each component of the operating theatre process and integrated them to give a combined value for surgical and anaesthetic time (end utilization) and total theatre efficiency (operating theatre utilization). Results:, Results showed that relative to the standards set, changeover time and start times were sub-standard, with consistently prolonged changeovers and late starts. End utilization and operating theatre utilization were 78.8 and 81%, against a standard of 77 and 85,90%, respectively. However, these figures may be misleading due to sub-standard performance in changeover time and other variables. Conclusions:, We have highlighted inefficiency in the orthopaedic trauma theatre at our institution and suggest various strategies to improve this that may be applied universally. [source] | |||||||||||||