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Sheng-I Chen is an associate professor at the Industrial Engineering and Management Department at National Yang Ming Chiao Tung University. He earned a Ph.D. degree from the Industrial Engineering Department, University of Pittsburgh. His research interests include mathematical programming, scheduling, routing, and healthcare applications.
This study focuses on the decisions of picking, inventory, ripening, delivering, and selling mangoes in a harvesting season. Demand, supply, and prices are uncertain, and their probability density functions are fitted based on actual trading data collected from the largest spot market in Taiwan. A stochastic programming model is formulated to minimize the expected cost under the considerations of labor, storage space, shelf life, and transportation restrictions. We implement the sample-average approximation to obtain a high-quality solution of the stochastic program. The analysis compares deterministic and stochastic solutions to assess the uncertain effect on the harvest decisions. Finally, the optimal harvest schedule of each mango variety is suggested based on the stochastic program solution.
Sheng-I Chen; Wei-Fu Chen. The Optimal Harvest Decisions for Natural and Artificial Maturation Mangoes under Uncertain Demand, Yields and Prices. Sustainability 2021, 13, 9660 .
AMA StyleSheng-I Chen, Wei-Fu Chen. The Optimal Harvest Decisions for Natural and Artificial Maturation Mangoes under Uncertain Demand, Yields and Prices. Sustainability. 2021; 13 (17):9660.
Chicago/Turabian StyleSheng-I Chen; Wei-Fu Chen. 2021. "The Optimal Harvest Decisions for Natural and Artificial Maturation Mangoes under Uncertain Demand, Yields and Prices." Sustainability 13, no. 17: 9660.
Sheng-I Chen; Yen-Che Tseng. A partitioning column approach for solving LED sorter manipulator path planning problems. Journal of Industrial & Management Optimization 2021, 1 .
AMA StyleSheng-I Chen, Yen-Che Tseng. A partitioning column approach for solving LED sorter manipulator path planning problems. Journal of Industrial & Management Optimization. 2021; ():1.
Chicago/Turabian StyleSheng-I Chen; Yen-Che Tseng. 2021. "A partitioning column approach for solving LED sorter manipulator path planning problems." Journal of Industrial & Management Optimization , no. : 1.
Accumulating evidence has shown that soy intake is associated with the prevention of cancers. However, the specific soy compound and cancer type should be considered before allocating a precise nutrient intervention.
Sheng-I Chen; Hsiao-Ting Tseng; Chia-Chien Hsieh. Evaluating the impact of soy compounds on breast cancer using the data mining approach. Food & Function 2020, 11, 4561 -4570.
AMA StyleSheng-I Chen, Hsiao-Ting Tseng, Chia-Chien Hsieh. Evaluating the impact of soy compounds on breast cancer using the data mining approach. Food & Function. 2020; 11 (5):4561-4570.
Chicago/Turabian StyleSheng-I Chen; Hsiao-Ting Tseng; Chia-Chien Hsieh. 2020. "Evaluating the impact of soy compounds on breast cancer using the data mining approach." Food & Function 11, no. 5: 4561-4570.
Sheng-I Chen; Chia-Yuan Wu. A stochastic programming model of vaccine preparation and administration for seasonal influenza interventions. Mathematical Biosciences and Engineering 2020, 17, 2984 -2997.
AMA StyleSheng-I Chen, Chia-Yuan Wu. A stochastic programming model of vaccine preparation and administration for seasonal influenza interventions. Mathematical Biosciences and Engineering. 2020; 17 (4):2984-2997.
Chicago/Turabian StyleSheng-I Chen; Chia-Yuan Wu. 2020. "A stochastic programming model of vaccine preparation and administration for seasonal influenza interventions." Mathematical Biosciences and Engineering 17, no. 4: 2984-2997.
We focus on the lot-sizing and scheduling problem with the additional considerations of machine eligibility, sequence-dependent setups, and uncertain demands. Multi-stage stochastic programming is proposed. We analyze the problem structure and suggest ways for modeling and solving large-scale stochastic integer programs. The analysis compares deterministic and stochastic model solutions to assess demand variance effects under the circumstances of increasing, fluctuating, and decreasing demands. The result shows that the expected cost performance of the stochastic programming model outperforms that of the deterministic model, in particular, when the demand is highly uncertain in the circumstance of an upward market trend. Our study can apply to the wafer fab manufacturing and other industries that heavily restricted by machine eligibility and demand uncertainties.
Sheng-I Chen; Delvinia Su. A multi-stage stochastic programming model of lot-sizing and scheduling problems with machine eligibilities and sequence-dependent setups. Annals of Operations Research 2019, 1 -16.
AMA StyleSheng-I Chen, Delvinia Su. A multi-stage stochastic programming model of lot-sizing and scheduling problems with machine eligibilities and sequence-dependent setups. Annals of Operations Research. 2019; ():1-16.
Chicago/Turabian StyleSheng-I Chen; Delvinia Su. 2019. "A multi-stage stochastic programming model of lot-sizing and scheduling problems with machine eligibilities and sequence-dependent setups." Annals of Operations Research , no. : 1-16.
This study examined the effectiveness of various vaccine policies against influenza. The transmission rate was calculated by use of the time-series influenza-like illness case during the year of 2009 and recent epidemics in Taiwan. We developed a stochastic compartmental model to analyze the transmission of influenza, where the population was stratified by location and age group, and the vaccine distribution was considered using the current policy. The simulation study compared the previous vaccine policy and a new policy with expanded coverage and various lengths of the vaccination campaign. The sensitivity analysis investigated different levels of vaccine efficacy to confirm the robustness of the recommended policies. Doubling vaccine coverage can decrease the number of infections effectively in the regular epidemic scenario. However, a peak of infections occurs if the duration of implementing vaccination is too long. In the 2009-like pandemic scenario, both increasing vaccine doses and reducing the program’s duration can mitigate infections, although the early outbreak restricts the effectiveness of vaccination programs. The finding indicates that only increasing vaccine coverage can reduce influenza infections. To avoid the peak of infections, it is also necessary to execute the vaccination activity immediately. Vaccine efficacy significantly impacts the vaccination policy’s performance. When vaccine efficacy is low, neither increasing vaccination doses nor reducing vaccination timeframe prevents infections. Therefore, the variation in vaccine efficacy should be taken into account when making immunization policies against influenza.
Sheng-I Chen; Chia-Yuan Wu; Yu-Hsuan Wu; Min-Wei Hsieh. Optimizing influenza vaccine policies for controlling 2009-like pandemics and regular outbreaks. PeerJ 2019, 7, e6340 .
AMA StyleSheng-I Chen, Chia-Yuan Wu, Yu-Hsuan Wu, Min-Wei Hsieh. Optimizing influenza vaccine policies for controlling 2009-like pandemics and regular outbreaks. PeerJ. 2019; 7 ():e6340.
Chicago/Turabian StyleSheng-I Chen; Chia-Yuan Wu; Yu-Hsuan Wu; Min-Wei Hsieh. 2019. "Optimizing influenza vaccine policies for controlling 2009-like pandemics and regular outbreaks." PeerJ 7, no. : e6340.
Recurrent influenza outbreak has been a concern for government health institutions in Taiwan. Over 10% of the population is infected by influenza viruses every year, and the infection has caused losses to both health and the economy. Approximately three million free vaccine doses are ordered and administered to high-risk populations at the beginning of flu season to control the disease. The government recommends sharing and redistributing vaccine inventories when shortages occur. While this policy intends to increase inventory flexibility, and has been proven as widely valuable, its impact on vaccine availability has not been previously reported. This study developed an inventory model adapted to vaccination protocols to evaluate government recommended polices under different levels of vaccine production. Demands were uncertain and stratified by ages and locations according to the demographic data in Taiwan. When vaccine supply is sufficient, sharing pediatric vaccine reduced vaccine unavailability by 43% and overstock by 54%, and sharing adult vaccine reduced vaccine unavailability by 9% and overstock by 15%. Redistributing vaccines obtained greater gains for both pediatrics and adults (by 75%). When the vaccine supply is in short, only sharing pediatric vaccine yielded a 48% reduction of unused inventory, while other polices do not improve performances. When implementing vaccination activities for seasonal influenza intervention, it is important to consider mismatches of demand and vaccine inventory. Our model confirmed that sharing and redistributing vaccines can substantially increase availability and reduce unused vaccines.
Sheng-I Chen. Economic benefits of sharing and redistributing influenza vaccines when shortages occurred. PLOS ONE 2017, 12, e0186418 .
AMA StyleSheng-I Chen. Economic benefits of sharing and redistributing influenza vaccines when shortages occurred. PLOS ONE. 2017; 12 (10):e0186418.
Chicago/Turabian StyleSheng-I Chen. 2017. "Economic benefits of sharing and redistributing influenza vaccines when shortages occurred." PLOS ONE 12, no. 10: e0186418.