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.

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.

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.

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.

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.

15-Hydroxyprostaglandin dehydrogenase inactivation as a mechanism of resistance to celecoxib chemoprevention of colon tumors.

Yan, Min,Myung, Seung-Jae,Fink, Stephen P,Lawrence, Earl,Lutterbaugh, James,Yang, Peiying,Zhou, Xiaohua,Liu, Danielle,Rerko, Ronald M,Willis, Joseph,Dawson, Dawn,Tai, Hsin-Hsiung,Barnholtz-Sloan, Jill National Academy of Sciences 2009 PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF Vol.106 No.23

<P>Pharmacologic inhibitors of the prostaglandin-synthesizing COX-2 oncogene prevent the development of premalignant human colon adenomas. However, resistance to treatment is common. In this study, we show that the adenoma prevention activity of the COX-2 inhibitor celecoxib requires the concomitant presence of the 15-hydroxyprostaglandin dehydrogenase (15-PGDH) tumor suppressor gene, and that loss of 15-PGDH expression imparts resistance to celecoxib's anti-tumor effects. We first demonstrate that the adenoma-preventive activity of celecoxib is abrogated in mice genetically lacking 15-PGDH. In FVB mice, celecoxib prevents 85% of azoxymethane-induced tumors >1 mm in size, but is essentially inactive in preventing tumor induction in 15-PGDH-null animals. Indeed, celecoxib treated 15-PGDH null animals develop more tumors than do celecoxib naive WT mice. In parallel with the loss of tumor prevention activity, celecoxib-mediated suppression of colonic PGE(2) levels is also markedly attenuated in 15-PGDH-null versus WT mice. Finally, as predicted by the murine models, humans with low colonic 15-PGDH levels also exhibit celecoxib resistance. Specifically, in a colon adenoma prevention trial, in all cases tested, individuals who developed new adenomas while receiving celecoxib treatment were also found as having low colonic 15-PGDH levels.</P>

Reduction of Physical Strength and Enhancement of Anti-Protein and Anti-Lipid Adsorption Abilities of Contact Lenses by Adding 2-Methacryloyloxyethyl Phosphorylcholine

Wan-Hsin Chang,Pei-Yi Liu,Chien-Ju Lu,Dai-En Lin,Min-Hsuan Lin,Yuan-Ting Jiang,Yuan-Hao Howard Hsu 한국고분자학회 2020 Macromolecular Research Vol.28 No.12

Biocompatible 2-methacryloyloxyethyl phosphorylcholine (MPC) can enhance the adsorption of water molecules and is therefore used for manufacturing contact lenses. This study investigated the mechanical strength, anti-protein deposition, and anti-lipid adsorption effects of MPC addition to contact lenses. Experimental contact lenses produced by copolymerizing multiple ratios of MPC to 2-hydroxyethyl methacrylate (HEMA) were analyzed. Atomic force microscopy revealed that MPC addition increased surface roughness. The anti-protein deposition and anti-lipid adsorption effects on poly(HEMA-MPC) polymers of various phosphorylcholine quantities were experimentally confirmed. The water content of the contact lenses was proportional to the MPC content in the polymer. The hydrated PC moiety of MPC drastically altered the network of the poly-HEMA polymer by inserting water molecules, which were trapped in the concave region of the surface. MPC addition had negative effects on all examined strength factors because of structural destabilization of the copolymer through water insertion. The anti-deposition effects of MPC were verified by examining the lysozyme and lipid adsorption abilities of the prepared contact lenses. Our results revealed that MPC enhanced interactions of the poly(HEMA-MPC) copolymer with water molecules; these interactions weakened the mechanical strength of the copolymer but markedly improved the anti-adsorption property of the biomolecules. The optimal proportion of HEMA–MPC for contact lenses is in the range 14.9%-28.5%.

Influencing Factors of Intention to Receive Pap Tests in Vietnamese Women who Immigrated to Taiwan for Marriage

Fang-Hsin Lee,Hsiu-Hung Wang,Yung-Mei Yang,Joh-Jong Huang,Hsiu-Min Tsai 한국간호과학회 2016 Asian Nursing Research Vol.10 No.3

Purpose: This study aimed to explore the factors associated with the intention to receive a Pap test among married immigrant women of Vietnamese origin living in Taiwan. Methods: This was a cross-sectional community-based study.We enrolled 281 women aged 30 years and over in the study, from July 2013 to January 2014. The participants' characteristics, cervical cancer knowledge, Pap test knowledge, attitudes toward cervical cancer, barriers to receiving a Pap test, fatalism, and intention to receive a Pap test, were measured using self-report questionnaires. Hierarchical multiple regression analyses were performed to examine the variables associated with participants' intentions to receive a Pap test. Results: Vietnamese women with low scores on the measures of cervical cancer knowledge and perceived barriers to receiving a Pap test were more willing to receive the test, as were those with high scores on the measures of Pap test knowledge and fatalism. Women who received a Pap test in the previous year were more willing to receive a Pap test within the next 3 years. Conclusions: Preventive healthcare for immigrant women should be a focus of nurses. The development of culturally appropriate health education and strategies should enhance their knowledge of Pap tests and reduce perceived barriers to Pap test participation. This study's results can be a reference for nurses who work with immigrant women.

Tests of reinforced concrete deep beams

Wen-Yao Lu,Hsin-Tai Hsiao,Chun-Liang Chen,Shu-Min Huang,Ming-Che Lin 사단법인 한국계산역학회 2015 Computers and Concrete, An International Journal Vol.15 No.3

This study reports the test results of twelve reinforced concrete deep beams. The deep beams were tested with loads applied through and supported by columns. The main variables studied were the shear span-to-depth ratios, and the horizontal and vertical stirrups. The shear strengths can be effectively enhanced for deep beams reinforced with both horizontal and vertical stirrups. The test results indicate the shear strengths of deep beams increase with the decrease of the shear span-to-depth ratios. The normalized shear strengths of the deep beams did not increase proportionally with an increase in effective depth. An analytical method for predicting the shear strengths of deep beams is proposed in this study. The shear strengths predicted by the proposed method and the strut-and-tie model of the ACI Code are compared with available test results. The comparison shows the proposed method can predict the shear strengths of reinforced concrete deep beams more accurately than the strut-and-tie model of the ACI Code.