Solving the Quadratic Assignment Problem by a Hybrid Algorithm

This paper presents a hybrid algorithm to solve the Quadratic Assignment Problem (QAP). The proposed algorithm involves using the Greedy Randomized Adaptive Search Procedure (GRASP) to obtain an initial solution, and then using a combined Simulated Annealing (SA) and Tabu Search (TS) algorithm to improve the solution. Experimental results  indicate that the hybrid algorithm is able to obtain good quality solutions for QAPLIB test problems within reasonable computation time

Solving the quadratic assignment problem by a Hybrid Algorithm

This paper presents a hybrid algorithm to solve the Quadratic Assignment Problem (QAP). The proposed algorithm involves using the Greedy Randomized Adaptive Search Procedure (GRASP) to obtain an initial solution, and then using a combined Simulated Annealing (SA) and Tabu Search (TS) algorithm to improve the solution. Experimental results  indicate that the hybrid algorithm is able to obtain good quality solutions for QAPLIB test problems within reasonable computation time

Solving the teacher assignment-course scheduling problem by a hybrid Algorithm

This paper presents a hybrid algorithm for solving a timetabling problem, which is commonly encountered in many universities. The problem combines both teacher assignment and course scheduling problems simultaneously, and is presented as a mathematical programming model. However, this problem becomes intractable and it is unlikely that a proven optimal solution can be obtained by an integer programming approach, especially for large problem instances. A hybrid algorithm that combines an integer programming approach, a greedy heuristic and a modified simulated annealing algorithm collaboratively is proposed to solve the problem. Several randomly generated data sets of sizes comparable to that of an institution in Indonesia are solved using the proposed algorithm. Computational results indicate that the algorithm can overcome difficulties of large problem sizes encountered in previous related works

Identification of bradycardia following remdesivir administration through the US Food and Drug Administration American College of Medical Toxicology COVID-19 Toxic Pharmacovigilance Project

IMPORTANCE: The rapid spread and mortality associated with COVID-19 emphasized a need for surveillance system development to identify adverse events (AEs) to emerging therapeutics. Bradycardia is a remdesivir infusion-associated AE listed in the US Food and Drug Administration-approved prescribing information. OBJECTIVE: To evaluate the magnitude and duration of bradycardic events following remdesivir administration. DESIGN, SETTING, AND PARTICIPANTS: A multicenter cohort study of patients with recorded heart rate less than 60 beats per minute within 24 hours after administration of a remdesivir dose was conducted between November 23, 2020, and October 31, 2021. Participants included patients hospitalized with COVID-19 at 15 medical centers across the US. Patients excluded had AEs unrelated to bradycardia, AEs in addition to bradycardia, or first onset of bradycardia after 5 remdesivir doses. EXPOSURES: Remdesivir administration. MAIN OUTCOMES AND MEASURES: Linear mixed-effect models for the minimum HR before starting remdesivir and within 24 hours of each dose included doses as fixed effects. Baseline covariates were age (≥65 years vs \u3c65 years), sex (male vs female), cardiovascular disease history (yes vs no), and concomitant use of bradycardia-associated medications. The interactions between variables and doses were considered fixed-effects covariates to adjust models. RESULTS: A total of 188 patients were included in the primary analysis and 181 in the secondary analysis. The cohort included 108 men (57.4%); 75 individuals (39.9%) were non-Hispanic White and mean (SD) age was 61.3 (15.4) years. Minimum HR after doses 1 to 5 was lower than before remdesivir. Mean minimum HR was lowest after dose 4, decreasing by -15.2 beats per minute (95% CI, -17.4 to -13.1; P \u3c .001) compared with before remdesivir administration. Mean (SD) minimum HR was 55.6 (10.2) beats per minute across all 5 doses. Of 181 patients included in time-to-event analysis, 91 had their first episode of bradycardia within 23.4 hours (95% CI, 20.1-31.5 hours) and 91 had their lowest HR within 60.7 hours (95% CI, 54.0-68.3 hours). Median time to first bradycardia after starting remdesivir was shorter for patients aged 65 years or older vs those younger than 65 years (18.7 hours; 95% CI, 16.8-23.7 hours vs 31.5 hours; 95% CI, 22.7-39.3 hours; P = .04). Median time to lowest HR was shorter for men vs women (54.2 hours; 95% CI, 47.3-62.0 hours vs 71.0 hours; 95% CI, 59.5-79.6 hours; P = .02). CONCLUSIONS AND RELEVANCE: In this cohort study, bradycardia occurred during remdesivir infusion and persisted. Given the widespread use of remdesivir, practitioners should be aware of this safety signal

The Toxicology Investigators Consortium 2020 Annual Report.

The Toxicology Investigators Consortium (ToxIC) Registry was established by the American College of Medical Toxicology in 2010. The registry collects data from participating sites with the agreement that all bedside and telehealth medical toxicology consultation will be entered. This eleventh annual report summarizes the Registry\u27s 2020 data and activity with its additional 6668 cases. Cases were identified for inclusion in this report by a query of the ToxIC database for any case entered from January 1 to December 31, 2020. Detailed data was collected from these cases and aggregated to provide information which included demographics, reason for medical toxicology evaluation, agent and agent class, clinical signs and symptoms, treatments and antidotes administered, mortality, and whether life support was withdrawn. Gender distribution included 50.6% cases in females, 48.4% in males, and 1.0% identifying as transgender. Non-opioid analgesics were the most commonly reported agent class, followed by opioid and antidepressant classes. Acetaminophen was once again the most common agent reported. There were 80 fatalities, comprising 1.2% of all registry cases. Major trends in demographics and exposure characteristics remained similar to past years\u27 reports. Sub-analyses were conducted to describe race and ethnicity demographics and exposures in the registry, telemedicine encounters, and cases related to the COVID-19 pandemic

Permit Allocation in Emissions Trading using the Boltzmann Distribution

In emissions trading, the initial allocation of permits is an intractable issue because it needs to be essentially fair to the participating countries. There are many ways to distribute a given total amount of emissions permits among countries, but the existing distribution methods, such as auctioning and grandfathering, have been debated. In this paper we describe a new method for allocating permits in emissions trading using the Boltzmann distribution. We introduce the Boltzmann distribution to permit allocation by combining it with concepts in emissions trading. We then demonstrate through empirical data analysis how emissions permits can be allocated in practice among participating countries. The new allocation method using the Boltzmann distribution describes the most probable, natural, and unbiased distribution of emissions permits among multiple countries. Simple and versatile, this new method holds potential for many economic and environmental applications.Comment: 25 pages of main text, 3 figures, 3 table