9 research outputs found

    Post-disaster waste management with carbon tax policy consideration

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    Generally, the activities of post-disaster waste management usually produce high carbon emissions, which can cause damage to the environment. However, the issue of carbon emissions in the post-disaster waste supply chain is neglected. Hence, this paper aims to propose a mixed-integer linear programming model to address the post-disaster waste processing supply chain network design problem with the consideration of a carbon tax policy. The proposed model is developed based on the concept of a mixed strategy of waste separation to reduce carbon emissions. Not only the carbon emission perspective but also the financial perspective for post-disaster waste supply chain management is determined in the objective function. The proposed model was verified and validated by employing a numerical example based on realistic data. Based on the numerical example, the results show that the implementation of a carbon tax policy with the mixed strategy for waste separation can reduce carbon emissions in the post-disaster waste supply chain efficiently. (C) 2021 The Authors. Published by Elsevier Ltd

    University course timetabling problem considering day and time pattern

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    Layout design of outpatient department: simulation study and implementation

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    Background: Hospital layout is one important factor affecting hospital service quality and, consequently, patient satisfaction. Generally, the layout is designed based on the experience of the hospital specialists without any systematic approaches. Purpose: Due to the increasing number of patients, the case study hospital has built a new multi-floor building to move its Outpatient Department (OPD) to operate there. Therefore, this study aims to apply the Activity Relationship Analysis (ARA) and simulation to design a new OPD layout. Methodology: Data of the previous system were analyzed using the ARA. The results were then used to design three scenarios (A, C, and D) and the other three scenarios (B, E, and F) were proposed by hospital specialists. Then, six layouts were evaluated using simulation tests and the efficiencies of the designs were measured by an average total service time per patient. Results: The simulation results showed that the average total service time of scenario A, D, E, and F were lower than scenario B and C. While the average total service time at the sub-service unit of D was the longest compared to scenario A, E, and F. These results demonstrated that scenario A, E, and F were the most efficient layouts. However, when considered thoroughly by the hospital specialists, scenario A was eventually selected. Conclusion: This study can contribute to scientific literature as it demonstrates the application of the ARA and simulation in the design of the multi-floor layout, an aspect under-researched in existing studies. This study also provides the practical implication suggesting that these techniques should be used together in the layout designs because they can help to determine the correctness and efficiency of the layout design before actual implementation

    Shallot Price Forecasting Models: Comparison among Various Techniques

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    Shallot is one of several horticultural products exported from Thailand to various countries. Despite an increase in shallot prices over the years, farmers face challenges in price forecasting due to fluctuations and other relevant factors. While different forecasting techniques exist in the literature, there is no universal approach due to varying problems and datasets. This study focuses on predicting shallot prices in Northern Thailand from January 2014 to December 2020. Traditional and machine learning models, including ARIMA, Holt-Winters, LSTM, and ARIMA-LSTM hybrids, are proposed. The LSTM model considers temperature and rainfall as influencing factors. Evaluation metrics include RMSE, MAE, and MAPE. Results indicate that the ARIMA-LSTM hybrid model performs best, with RMSE, MAE, and MAPE values of 10.275 Baht, 8.512 Baht, and 13.618%, respectively. Implementing this hybrid model can provide shallot farmers with advanced price information for informed decision-making regarding cultivation expansion and production management

    Poprawa systemu opieki zdrowotnej na przykładzie sieci szpitali w górnym północnym regionie Tajlandii

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    Cleft lip and/or cleft palate are the most common craniofacial congenital disability, with an estimated 2 affected babies born per thousand in Thailand. Chiang Mai University Craniofacial (CMU CF) center plays a role as the one-stop service providing this type of healthcare. This center serves as the coordinator between hospitals in the treatment network and patients. This research aims to reduce the delays throughout the patients’ treatment plan of the case study hospital as one of the hospitals in this network. Starting with problem identification, two treatment steps, including hearing testing (ABR/OAE) and Cheiloplasty, were 80% of the total delay from the data collection. Then, Root-cause analysis was conducted by interviewing specialists and studying patients’ documents. The main cause of delays was that the patients needed to be transferred from rural hospitals in the area to the hospital that is the subject of our case study. The supporting operations that help in serving patients need co-working operations between the case study hospital and the CMU CF center. Supporting operations including 4 parts were studied and improved based on the Lean concept. Standard procedures were set up when non-value-added activities were eliminated, and value-added activities were improved by IT solution implementation. Finally, when the supporting operations were performed via an IT solution, the processing time can be reduced. Moreover, the implementation of an IT solution helps in tracking and monitoring patients’ status – this advantage leads to a reduction in the number of delayed patients and a reduced delay time in the treatment plan.Rozszczep wargi i/lub rozszczep podniebienia to najczęstsze wrodzone wady twarzoczaszki. Szacuje się, że w Tajlandii corocznie ten problem dotyka dwóch spośród tysiąca dzieci. Centrum Twarzoczaszki Uniwersytetu Chiang Mai (CMU CF) realizuje kompleksową obsługę opieki zdrowotnej w tym zakresie. Ośrodek ten pełni także funkcję koordynatora wśród szpitali leczących tę dolegliwość. Niniejsze badanie ma na celu zmniejszenie opóźnienia w realizacji planów leczenia pacjentów i jest studium przypadku jednego ze szpitali w sieci. Na drodze przeprowadzonej identyfikacji problemu stwierdzono, że dwa etapy leczenia, w tym badanie słuchu (ABR/OAE) i cheiloplastyka, stanowiły 80% całkowitego opóźnienia spośród zgromadzonych danych. Następnie wykonano analizę przyczynową, przeprowadzono wywiady ze specjalistami i zbadano dokumentację pacjentów. Głównym powodem opóźnienia procesu leczenia okazało się przenoszenie pacjentów z innych szpitali na obszarach wiejskich do badanego szpitala. W szczególności newralgiczne okazały się czynności pomocnicze, które służą obsłudze pacjentów i wymagają współpracy pomiędzy badanym szpitalem a ośrodkiem CMU CF. Czynności te, obejmujące cztery fazy, zostały zbadane i udoskonalone na podstawie koncepcji Lean. Ustalono standardowe procedury, wyeliminowano działania nieprzynoszące wartości i usprawniono te, które przynoszą wartość, przez wdrożenie rozwiązania informatycznego. Ostatecznie ustalono, że gdy czynności pomocnicze są realizowane za pośrednictwem rozwiązania informatycznego, czas przetwarzania może ulec skróceniu. Ponadto wdrożenie rozwiązania informatycznego pomaga w śledzeniu i monitorowaniu stanu pacjenta, co prowadzi również do zmniejszenia liczby opóźnionych pacjentów i skrócenia czasu opóźnienia w stosunku do założonego planu leczenia

    Value estimation of end of life vehicles as a source of competitive advantage for dismantling station

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      Background: End of Life vehicles become an emerging problem because of the type of waste which they are. Each country is creating own recycling network where ELVs are well secured and recycled. Poland is a country where the system is not working correct because of a high absorption of ELVs by illegal dismantling entities which are more competitive than legal elements of recycling network. The problem is well known but there is still lack of solution. The purpose of this article is to present the concept of tools for the valuation of ELVs in order to improve the competitiveness of disassembly stations. Methods: The research methodology consists of a literature review as well as observations, surveys, BPMN and UML diagrams. On the basis of literature review and observations the problem was identified. The surveys were elaborated in order to identify requirements for the concept of the tool. BPMN and UML diagrams were used to model the processes in dismantling station and the information flow between the user and the tool. Results: There was established a concept of the tool - ELV's Calculator which support decisions of ELV's value estimation. Conclusions: Improving competitiveness of legal dismantling station is extremely important issue in order to provide safe for Environment and People and economically justified ELVs' management. Legal entities have to follow the law what makes their business cost higher. This paper provides a solution of encouraging people to return ELVs to legal dismantlers by offering them price adequate to market demand.   &nbsp

    Application of Simulation Technique for Improving Plant Layout in Ceramic Factory

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    This study aims to design and improve the plant layout of a ceramic factory by adopting Systematic Layout Planning (SLP) and the simulation technique. A ceramic company in northern Thailand is selected as a case study. Three ceramic products including roof tiles, wall tiles and dishware are studied due to their highest production volume. Through the SLP approach, information regarding the number of departments and machines, the area of the plant, the frequency of movement and the distance between each department is collected for the analysis of the relationship between departments. Two plant layout designs are then proposed; the first one is derived from the Computerized Relationship Layout Planning algorithm (CORELAP), and the second one is the process layout. For selecting the most appropriate layout design, five criteria are considered including total distance, the average total process time of each unit produced, ease of movement, material flow and safety. To determine the distance and the average total process time per unit, Distance-Based Scoring and simulation techniques are conducted while the ease of movement, material flow and safety are rated based on whether the company satisfies each criterion. Employing the weight scoring technique, the results report that the CORELAP layout is the most suitable for further implementation due to its highest weighted score equal to 2.536 while the process layout receives 2.386. Implementing the CORELAP layout can reduce the total distance by 16.76% while the average total process time per unit of the CORELAP layout is not significantly different at the significance level of 0.05 as compared to the existing layout

    Post-disaster waste management with carbon tax policy consideration

    No full text
    application/pdfGenerally, the activities of post-disaster waste management usually produce high carbon emissions, which can cause damage to the environment. However, the issue of carbon emissions in the post-disaster waste supply chain is neglected. Hence, this paper aims to propose a mixed-integer linear programming model to address the post-disaster waste processing supply chain network design problem with the consideration of a carbon tax policy. The proposed model is developed based on the concept of a mixed strategy of waste separation to reduce carbon emissions. Not only the carbon emission perspective but also the financial perspective for post-disaster waste supply chain management is determined in the objective function. The proposed model was verified and validated by employing a numerical example based on realistic data. Based on the numerical example, the results show that the implementation of a carbon tax policy with the mixed strategy for waste separation can reduce carbon emissions in the post-disaster waste supply chain efficiently. (C) 2021 The Authors. Published by Elsevier Ltd
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