@article{sahebi-fakhrabad_sadeghi_kemahlioglu-ziya_handfield_tohidi_vasheghani-farahani_2023, title={The Impact of Opioid Prescribing Limits on Drug Usage in South Carolina: A Novel Geospatial and Time Series Data Analysis}, volume={11}, ISSN={["2227-9032"]}, url={https://doi.org/10.3390/healthcare11081132}, DOI={10.3390/healthcare11081132}, abstractNote={The opioid crisis in the United States has had devastating effects on communities across the country, leading many states to pass legislation that limits the prescription of opioid medications in an effort to reduce the number of overdose deaths. This study investigates the impact of South Carolina’s prescription limit law (S.C. Code Ann. 44-53-360), which aims to reduce opioid overdose deaths, on opioid prescription rates. The study utilizes South Carolina Reporting and Identification Prescription Tracking System (SCRIPTS) data and proposes a distance classification system to group records based on proximity and evaluates prescription volumes in each distance class. Prescription volumes were found to be highest in classes with pharmacies located further away from the patient. An Interrupted Time Series (ITS) model is utilized to assess the policy impact, with benzodiazepine prescriptions as a control group. The ITS models indicate an overall decrease in prescription volume, but with varying impacts across the different distance classes. While the policy effectively reduced opioid prescription volumes overall, an unintended consequence was observed as prescription volume increased in areas where prescribers were located at far distances from patients, highlighting the limitations of state-level policies on doctors. These findings contribute to the understanding of the effects of prescription limit laws on opioid prescription rates and the importance of considering location and distance in policy design and implementation.}, number={8}, journal={HEALTHCARE}, author={Sahebi-Fakhrabad, Amirreza and Sadeghi, Amir Hossein and Kemahlioglu-Ziya, Eda and Handfield, Robert and Tohidi, Hossein and Vasheghani-Farahani, Iman}, year={2023}, month={Apr} }
 @article{guasque_tohidi_balbastre_aceituno_simo_crespo_2020, title={Integer Programming Techniques for Static Scheduling of Hard Real-Time Systems}, volume={8}, ISSN={["2169-3536"]}, DOI={10.1109/ACCESS.2020.3024698}, abstractNote={Hard real-time systems focus on obtaining a feasible schedule while satisfying different temporal requirements. In safety-critical applications, this schedule is generated offline. This article explores different integer linear programming techniques (ILP) to schedule uniprocessor hard real-time systems. The goal is to efficiently obtain a static schedule for periodic tasks and partitioned systems where temporal and spatial isolation is crucial. The advantage of the proposed ILP techniques is the possibility of choosing the optimization criteria so that deadlines are met and better performance quality is achieved. The drawback is the time spent finding an optimal solution. We propose an ILP method that reduces by 70% the time needed to obtain an optimal solution compared to basic approaches. This method is called the rolling task MILP approach and the optimization problem is addressed task by task. Experimental results show that our approach also achieves better results than heuristics when trying to reduce temporal parameters such as response times, context switches, and jitter. This makes our solution suitable for control systems and other applications.}, journal={IEEE ACCESS}, author={Guasque, Ana and Tohidi, Hossein and Balbastre, Patricia and Aceituno, Jose Maria and Simo, Jose and Crespo, Alfons}, year={2020}, pages={170389–170403} }
 @article{tohidi_algeddawy_2020, title={Optimization of Modular Fixture Setup Time in an Automated Assembly Line}, ISBN={["978-3-030-50793-0"]}, ISSN={["2195-4364"]}, DOI={10.1007/978-3-030-50794-7_33}, abstractNote={Designing and fabricating different fixtures are among the main barriers for manufacturing systems to produce a variety of products with different geometries. To overcome the time and costs associated with the frequent changes in fixture design, modular fixtures have been developed. The changeability plan of these fixtures is vital for changeable manufacturing systems, especially in automated systems in which robots are in charge of placing and securing parts in their respective places. In this paper, we are extending the model presented in the literature in two directions to further reduce the fixture setup time in a mid-volume mid-variety automated production system. First, we consider both vertical and horizontal movement of the robot to find the optimal changeability plan. Then, a new fixture design is introduced that improves the fixture modularity to hold more products with different geometries. The results prove that the newly proposed models can significantly reduce fixture setup time.}, journal={ADVANCES IN DESIGN, SIMULATION AND MANUFACTURING III: MANUFACTURING AND MATERIALS ENGINEERING, VOL 1}, author={Tohidi, Hossein and AlGeddawy, Tarek}, year={2020}, pages={336–346} }
 @article{tohidi_algeddawy_2019, title={Change management in modular assembly systems to correspond to product geometry change}, volume={57}, ISSN={["1366-588X"]}, DOI={10.1080/00207543.2018.1559374}, abstractNote={Modular assembly systems are a category of changeable manufacturing systems, which can handle the rapid change in customer demands, product design change and market fluctuations. On the operational level, jigs and fixtures are fundamental elements of assembly systems. They are used to hold parts and subassemblies in place, and directly affect assembly cost, quality and time. Therefore, modular fixtures that can adapt to different geometries are becoming a very important enabler for changeable manufacturing. In this paper, two mathematical models are presented to optimise the use of a passive modular assembly fixture plan in an automated assembly system by considering different production scenarios and constraints. These models optimise the changeability plan of the modular fixture by minimising the number of dowel replacements between different part geometries assuming that the candidate dowels locations for each part have been determined using existing methods in the literature by considering different assembly requirements. The first model, LRTE, considers all possible part rotations and translations on the fixture to minimise setup time. In addition, the second model, SLRTE, enables the system to simultaneously optimise job sequence. This paper presents various examples in different sizes, and the results show that the model can effectively reduce the fixture setup time up to %50.}, number={19}, journal={INTERNATIONAL JOURNAL OF PRODUCTION RESEARCH}, author={Tohidi, Hossein and AlGeddawy, Tarek}, year={2019}, month={Oct}, pages={6048–6060} }