The Incremental Cost Matrix Procedure for Locating Repair Service Centers in Multinational Reverse Logistics

Hsin Min Chen,Chih Kuang Hsieh,Ming Cheng Wu,Shin Wei Luo 대한산업공학회 2009 Industrial Engineeering & Management Systems Vol.8 No.3

This study provides a heuristic algorithm to solve the locating problem of repair service centers (RSCs). To enhance the customer service level with more satisfaction and quicker responsiveness, the locating problem of RSCs has become one of the important issues in reverse supply chain management. This problem is formulated as a zero-one mixed integer programming in which an exiting distributor will be considered to be an un-capacitated repair service center for the objective of cost-minimizing. Since logistical costs are highly interrelated with the multinational location of distributors and RSCs, the fixed cost for setting a repair service center, variable cost, transportation cost, and exchange rates are considered in this study. Recognizing the selection of un-capacitated RSCs’ locations is a combinatorial optimization problem and is a zero-one mixed integer programming with NP-hard complexity, we provide a heuristic algorithm named as incremental cost matrix procedure (ICMP) to simplify the solving procedure. By using the concise and structural cost matrix, ICMP can efficiently screen the potential location with cost advantage and effectively decide which distributor should be a RSC. Results obtained from the numerical experiments conducted in small scale problem have shown the fact that ICMP is an effective and efficient heuristic algorithm for solving the RSCs locating problem. In the future, using the extended ICMP to solve problems with larger industrial scale or problems with congestion effects caused by the variation of customer demand and the restriction of the RSC capacity is worth a further investigation.

The Incremental Cost Matrix Procedure for Locating Repair Service Centers in Multinational Reverse Logistics

Chen, Hsin Min,Hsieh, Chih Kuang,Wu, Ming Cheng,Luo, Shin Wei Korean Institute of Industrial Engineers 2009 Industrial Engineeering & Management Systems Vol.8 No.3

This study provides a heuristic algorithm to solve the locating problem of repair service centers (RSCs). To enhance the customer service level with more satisfaction and quicker responsiveness, the locating problem of RSCs has become one of the important issues in reverse supply chain management. This problem is formulated as a zero-one mixed integer programming in which an exiting distributor will be considered to be an un-capacitated repair service center for the objective of cost-minimizing. Since logistical costs are highly interrelated with the multinational location of distributors and RSCs, the fixed cost for setting a repair service center, variable cost, transportation cost, and exchange rates are considered in this study. Recognizing the selection of un-capacitated RSCs' locations is a combinatorial optimization problem and is a zero-one mixed integer programming with NP-hard complexity, we provide a heuristic algorithm named as incremental cost matrix procedure (ICMP) to simplify the solving procedure. By using the concise and structural cost matrix, ICMP can efficiently screen the potential location with cost advantage and effectively decide which distributor should be a RSC. Results obtained from the numerical experiments conducted in small scale problem have shown the fact that ICMP is an effective and efficient heuristic algorithm for solving the RSCs locating problem. In the future, using the extended ICMP to solve problems with larger industrial scale or problems with congestion effects caused by the variation of customer demand and the restriction of the RSC capacity is worth a further investigation.

The Relationship Between Night Shift Work and the Risk of Abnormal Thyroid-Stimulating Hormone: A Hospital-Based Nine-Year Follow-up Retrospective Cohort Study in Taiwan

Chen, Hsin-Hao,Chiu, Hsiao-Hui,Yeh, Tzu-Lin,Lin, Chi-Min,Huang, Hsin-Yi,Wu, Shang-Liang Occupational Safety and Health Research Institute 2021 Safety and health at work Vol.12 No.3

Background: Health-care providers typically undergo shift work and are subjected to increased stress. Night shift work may induce disturbed sleep cycles and circadian rhythm. The objective of this study was to explore if night shift workers (NSWs) show an increased risk of abnormal thyroid-stimulating hormone (TSH). Methods: We conducted a retrospective cohort study of 574 employees without thyroid disease and abnormal TSH at baseline who underwent annual check-ups between 2007 and 2016 in a medical center. NSWs were defined as those with working time schedules other than daytime hours. We calculated the incidence rate and estimated the adjusted hazard ratio (HR) for incident abnormal TSH and subclinical hypothyroidism compared with non-NSWs using a Cox regression model. Results: A total of 56 incident abnormal TSH cases and 39 subclinical hypothyroidism cases in NSWs were identified during 3000 person-years of follow-up. In models adjusted for age, sex, obesity, and working departments, we found no increased relative risk for incident abnormal TSH (HR: 0.72, 95% confidence interval: 0.33-1.60) or subclinical hypothyroidism (HR: 0.52, 95% confidence interval: 0.19-1.45) when comparing NSWs to non-NSWs; nor were incidence rates significantly different among exclusively medical employees after excluding administrative staff. Conclusion: In this hospital-based nine-year follow-up retrospective cohort study, NSWs were not associated with increased relative risk of incident abnormal TSH and subclinical hypothyroidism, in contrast to previous cross-sectional studies.

A retrospective analysis of 20-year data of the surgical management of ulcerative colitis patients in Taiwan: a study of Taiwan Society of Inflammatory Bowel Disease

( Chun-chi Lin ),( Shu-chen Wei ),( Been-ren Lin ),( Wen-sy-tsai ),( Jinn-shiun Chen ),( Tzu-chi Hsu ),( Wei-chen Lin ),( Tien-yu Huang ),( Te-hsin Chao ),( Hung-hsin Lin ),( Jau-min Wong ),( Jen-kou 대한장연구학회 2016 Intestinal Research Vol.14 No.3

Background/Aims: With the recent progress in medical treatment, surgery still plays a necessary and important role in treating ulcerative colitis (UC) patients. In this study, we analyzed the surgical results and outcomes of UC in Taiwan in the recent 20 years, via a multi-center study through the collaboration of Taiwan Society of IBD. Methods: A retrospective analysis of surgery data of UC patients from January 1, 1995, through December 31, 2014, in 6 Taiwan major medical centers was conducted. The patients’ demographic data, indications for surgery, and outcome details were recorded and analyzed. Results: The data of 87 UC patients who received surgical treatment were recorded. The median post-operative follow-up duration was 51.1 months and ranged from 0.4 to 300 months. The mean age at UC diagnosis was 45.3±16.0 years and that at operation was 48.5±15.2 years. The 3 leading indications for surgical intervention were uncontrolled bleeding (16.1%), perforation (13.8%), and intractability (12.6%). In total, 27.6% of surgeries were performed in an emergency setting. Total or subtotal colectomy with rectal preservation (41.4%) was the most common operation. There were 6 mortalities, all due to sepsis. Emergency operation and low pre-operative albumin level were significantly associated with poor survival (P =0.013 and 0.034, respectively). Conclusions: In the past 20 years, there was no significant change in the indications for surgery in UC patients. Emergency surgeries and low pre-operative albumin level were associated with poor survival. Therefore, an optimal timing of elective surgery for people with poorly controlled UC is paramount.

Biodegradation Kinetics of Diesel in a Wind-driven Bioventing System

Min-Hsin Liu,Cyuan-Fu Tsai,Bo-Yan Chen 한국지하수토양환경학회 2016 지하수토양환경 Vol.21 No.5

Bioremediation, which uses microbes to degrade most organic pollutants in soil and groundwater, can be used in solving environmental issues in various polluted sites. In this research, a wind-driven bioventing system is built to degrade about 20,000 mg/kg of high concentration diesel pollutants in soil-pollution mode. The wind-driven bioventing test was proceeded by the bioaugmentation method, and the indigenous microbes used were Bacillus cereus, Achromobacter xylosoxidans, and Pseudomonas putida. The phenomenon of two-stage diesel degradation of different rates was noted in the test. In order to interpret the results of the mode test, three microbes were used to degrade diesel pollutants of same high concentration in separated aerated batch-mixing vessels. The data derived thereof was input into the Haldane equation and calculated by non-linear regression analysis and trial-and-error methods to establish the kinetic parameters of these three microbes in bioventing diesel degradation. The results show that in the derivation of μm (maximum specific growth rate) in biodegradation kinetics parameters, Ks (half-saturation constant) for diesel substance affinity, and Ki (inhibition coefficient) for the adaptability of high concentration diesel degradation. The Ks is the lowest in the trend of the first stage degradation of Bacillus cereus in a high diesel concentration, whereas Ki is the highest, denoting that Bacillus cereus has the best adaptability in a high diesel concentration and is the most efficient in diesel substance affinity. All three microbes have a degradation rate of over 50% with regards to Pristane and Phytane, which are branched alkanes and the most important biological markers.

Biodegradation Kinetics of Diesel in a Wind-driven Bioventing System

Liu, Min-Hsin,Tsai, Cyuan-Fu,Chen, Bo-Yan Korean Society of Soil and Groundwater Environment 2016 지하수토양환경 Vol.21 No.5

Bioremediation, which uses microbes to degrade most organic pollutants in soil and groundwater, can be used in solving environmental issues in various polluted sites. In this research, a wind-driven bioventing system is built to degrade about 20,000 mg/kg of high concentration diesel pollutants in soil-pollution mode. The wind-driven bioventing test was proceeded by the bioaugmentation method, and the indigenous microbes used were Bacillus cereus, Achromobacter xylosoxidans, and Pseudomonas putida. The phenomenon of two-stage diesel degradation of different rates was noted in the test. In order to interpret the results of the mode test, three microbes were used to degrade diesel pollutants of same high concentration in separated aerated batch-mixing vessels. The data derived thereof was input into the Haldane equation and calculated by non-linear regression analysis and trial-and-error methods to establish the kinetic parameters of these three microbes in bioventing diesel degradation. The results show that in the derivation of μ_m (maximum specific growth rate) in biodegradation kinetics parameters, K_s (half-saturation constant) for diesel substance affinity, and K_i (inhibition coefficient) for the adaptability of high concentration diesel degradation. The K_s is the lowest in the trend of the first stage degradation of Bacillus cereus in a high diesel concentration, whereas K_i is the highest, denoting that Bacillus cereus has the best adaptability in a high diesel concentration and is the most efficient in diesel substance affinity. All three microbes have a degradation rate of over 50% with regards to Pristane and Phytane, which are branched alkanes and the most important biological markers.

Outcomes of limited period of adalimumab treatment in moderate to severe Crohn’s disease patients: Taiwan Society of Inflammatory Bowel Disease Study

( Wei-chen Lin ),( Jen-wei Chou ),( Hsu-heng Yen ),( Wen-hung Hsu ),( Hung-hsin Lin ),( Jen-kou Lin ),( Chiao-hsiung Chuang ),( Tien-yu Huang ),( Horng-yuan Wang ),( Shu-chen Wei ),( Jau-min Wong ) 대한장연구학회 2017 Intestinal Research Vol.15 No.4

Background/Aims: In Taiwan, due to budget limitations, the National Health Insurance only allows for a limited period of biologics use in treating moderate to severe Crohn’s disease (CD). We aimed to access the outcomes of CD patients following a limited period use of biologics, specifically focusing on the relapse rate and remission duration; also the response rate to second use when applicable. Methods: This was a multicenter, retrospective, observational study and we enrolled CD patients who had been treated with adalimumab (ADA) according to the insurance guidelines from 2009 to 2015. Results: A total of 54 CD patients, with follow-up of more than 6 months after the withdrawal of ADA, were enrolled. The average period of treatment with ADA was 16.7±9.7 months. After discontinuing ADA, 59.3% patients suffered a clinical relapse. In the univariate analysis, the reason for withdrawal was a risk factor for relapse (P=0.042). In the multivariate analysis, current smoker became an important risk factor for relapse (OR, 3.9; 95% CI, 1.2-14.8; P=0.044) and male sex was another risk factor (OR, 2.9; 95% CI, 1.1-8.6; P=0.049). For those 48 patients who received a second round of biologics, the clinical response was seen in 60.4%, and 1 anaphylaxis occurred. Conclusions: Fifty-nine percent of patients experienced a relapse after discontinuing the limited period of ADA treatment, and most of them occurred within 1 year following cessation. Male sex and current smoker were risk factors for relapse. Though 60.4% of the relapse patients responded to ADA again. (Intest Res 2017;15:487-494)

Monacolin K affects lipid metabolism through SIRT1/AMPK pathway in HepG2 cells

Chia-Hsin Huang,Shin-Mau Shiu,Min-Tze Wu,Wei-Lu Chen,Shyang-Guang Wang,Horng-Mo Lee 대한약학회 2013 Archives of Pharmacal Research Vol.36 No.12

Monacolin K is the secondary metabolite isolatedfrom Monascus spp. It is the natural form of lovastatin,which is clinically used to reduce the synthesis of cholesterolby inhibiting 3-hydroxy-3-methylglutaryl coenzyme Areductase. In the present study, monacolin K increased proteinexpression of SIRT1 and phosphorylation level of AMPactivatedprotein kinase (AMPK) in HepG2 cells. Throughactivation of SIRT1/AMPK pathway, monacolin Kincreased phosphorylation of acetyl CoA carboxylase andcaused nuclear translocation of forkhead box O1. The westernblotting results showed that monacolin K increasedexpression of adipose triglyceride lipase but decreasedabundances of fatty acid synthase (FAS) and sterol regulatory element-binding protein 1 (SREBP1). MonacolinK also decreased the intracellular accumulation of lipids asdemonstrated by Oil Red O staining. In addition, theimmunostaining showed that monacolin K prevented thenuclear translocation of SREBP1, indicating the associationwith down-regulation of FAS. All the demonstrated effectsof monacolin K were counteracted by nicotinamide orcompound C, the inhibitors of SIRT1 orAMPK. In summary,monacolin K reduces the lipid content through SIRT1/AMPK pathway in HepG2 cells, which promotes catabolismand inhibits anabolism of lipid.

Haloperidol and Other Antipsychotics Exposure before Endometrial Cancer Diagnosis: A Population-based Case-control Study

Wei-Ling Chen,Srinivasan Nithiyanantham,Yan-Chiao Mao,Chih-Hsin Muo,Chih-Pin Chuu,Shih-Ping Liu,Min-Wei Huang,Kuan-Pin Su 대한정신약물학회 2022 CLINICAL PSYCHOPHARMACOLOGY AND NEUROSCIENCE Vol.20 No.3

Objective: Endometrial cancer is the most common malignancy of the female genital tract worldwide, and the associated relationship between endometrial cancer formation and various antipsychotics need to be confirmed. Methods: We conducted a case-control study by using data from Taiwan National Health Insurance Research Database to compare individual antipsychotic exposure between females with and without endometrial cancer. Among 14,079,089 females in the 12-year population-based national dataset, 9,502 females with endometrial cancer were identified. Their medical records of exposure to antipsychotics, including quetiapine, haloperidol, risperidone, olanzapine, amisulpride, clozapine, and aripiprazole, for up to 3 years before endometrial cancer diagnosis were reviewed. Daily dosage and cumulative exposure days were analyzed in the risky antipsychotic users. Additionally, the subsequent 5-year mortality rate of endometrial cancer among users of the risky antipsychotic were also analyzed. Results: Among endometrial cancer patients, the proportion of those who have used haloperidol before being diagnosed with endometrial cancer is significantly higher than other antipsychotic users. The significant odds ratio (OR) and a 95% confidence interval of 1.75 (1.31−2.34) were noted. Furthermore, haloperidol users were associated with a significantly higher 5-year mortality rate after getting endometrial cancer than non-users. Conclusion: There is a high correlation between the use of haloperidol and endometrial cancer formation. However, the underlying pathological biomechanisms require additional investigations.

Persistent Charge-Density-Wave Order in Single-Layer TaSe₂

Ryu, Hyejin,Chen, Yi,Kim, Heejung,Tsai, Hsin-Zon,Tang, Shujie,Jiang, Juan,Liou, Franklin,Kahn, Salman,Jia, Caihong,Omrani, Arash A.,Shim, Ji Hoon,Hussain, Zahid,Shen, Zhi-Xun,Kim, Kyoo,Min, Byung Il,H American Chemical Society 2018 NANO LETTERS Vol.18 No.2

<P>We present the electronic characterization of single-layer 1H-TaSe2 grown by molecular beam epitaxy using a combined angle-resolved photoeinission spectroscopy, scanning tunneling microscopy/spectroscopy, and density functional theory calculations. We demonstrate that 3 x 3 charge-density-wave (CDW) order persists despite distinct changes in the low energy electronic. structure highlighted by the reduction in the number of-bands crossing the Fermi energy and the corresponding modification Of Fermi surface topology. Enhanced, spin-orbit coupling and lattice distortion in the single-layer play a crucial role in the formation of CDW order. Our findings provide a deeper understanding of the nature of COW order in the two-dimensional limit.</P>