Dataset Information

Single-machine scheduling to minimize total completion time and tardiness with two competing agents.

ABSTRACT: We consider a single-machine two-agent problem where the objective is to minimize a weighted combination of the total completion time and the total tardiness of jobs from the first agent given that no tardy jobs are allowed for the second agent. A branch-and-bound algorithm is developed to derive the optimal sequence and two simulated annealing heuristic algorithms are proposed to search for the near-optimal solutions. Computational experiments are also conducted to evaluate the proposed branch-and-bound and simulated annealing algorithms.

SUBMITTER: Lee WC

PROVIDER: S-EPMC3915531 | biostudies-other | 2014

REPOSITORIES: biostudies-other

ACCESS DATA

Similar Datasets

Project description:ObjectiveEvaluate completion of partial or total salpingectomy during Cesarean delivery based on intended procedure.Study designWe conducted a retrospective study of women who had a permanent contraception procedure during Cesarean delivery at an urban, academic hospital from November 2015 through April 2017. We reviewed all charts of women who had a Cesarean delivery to identify those who underwent concomitant tubal surgery, including both completed and attempted procedures. We compared demographic, medical, and obstetric characteristics of participants by planned and completed method using univariate analysis.ResultsWe identified 122 women who underwent Cesarean delivery with planned concurrent permanent contraception procedure. Thirty-two (26.2%) women preferred partial salpingectomy and 90 (73.8%) preferred total salpingectomy. All women who desired partial salpingectomy had the procedure performed. However, 17 (18.9%) women desiring total salpingectomy could not have the procedure performed bilaterally: nine underwent a mixed procedure and seven underwent bilateral partial salpingectomy because of adhesions, engorged vasculature, or unspecified reasons. One woman had significant adhesive disease preventing any procedure. Among women who planned a total salpingectomy, having ≥3 Cesarean deliveries was the only factor associated with needing an alternative procedure (P=.04).ConclusionAs interest in total salpingectomy for permanent contraception increases, surgeons should counsel women who are interested in total salpingectomy at time of Cesarean delivery that adhesions and tubal proximity to adjacent vessels may preclude completion of bilateral tubal removal and discuss alternative options prior to surgery.ImplicationsInterest in bilateral total salpingectomy for permanent contraception at the time of Cesarean delivery is increasing; accordingly, surgeons should counsel patients that adhesions and proximity to large vessels may preclude completion of bilateral total salpingectomy, especially in women who have had multiple prior Cesarean deliveries.

Project description:BACKGROUND:Effective strategies for contacting and recruiting study participants are critical in conducting clinical research. In this study, we conducted two sequential randomized controlled trials of mail- and telephone-based strategies for contacting and recruiting participants, and evaluated participant-related variables' association with time to survey completion and survey completion rates. Subjects eligible for this study were survivors of acute lung injury who had been previously enrolled in a 12-month observational follow-up study evaluating their physical, cognitive and mental health outcomes, with their last study visit completed at a median of 34 months previously. METHODS:Eligible subjects were contacted to complete a new research survey as part of two randomized trials, initially using a randomized mail-based contact strategy, followed by a randomized telephone-based contact strategy for non-responders to the mail strategy. Both strategies focused on using either a personalized versus a generic approach. In addition, 18 potentially relevant subject-related variables (e.g., demographics, last known physical and mental health status) were evaluated for association with time to survey completion. RESULTS:Of 308 eligible subjects, 67% completed the survey with a median (IQR) of 3 (2, 5) contact attempts required. There was no significant difference in the time to survey completion for either randomized trial of mail- or phone-based contact strategy. Among all subject-related variables, age ?40 years and minority race were independently associated with a longer time to survey completion. CONCLUSION:We found that age ?40 years and minority race were associated with a longer time to survey completion, but personalized versus generic approaches to mail- and telephone-based contact strategies had no significant effect. Repeating both mail and telephone contact attempts was important for increasing survey completion rate. TRIAL REGISTRATION:NCT00719446.

Dataset Information

Single-machine scheduling to minimize total completion time and tardiness with two competing agents.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets