• Journal of Korean Society for Quality Management
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• v.36 no.3
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• pp.102-111
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• 2008

본 연구에서는 공급리드타임이 한정된 용량을 가진 생산시스템에 의해서 내부적으로 결정되어지는 다품종 재고시스템에서의 제품의 수요변동이 미치는 영향을 조사하였다. 공급리드타임이 시스템의 외부에서 결정되어 주어지는 경우와는 달리 리드타임 수요의 변동이 제품 수요의 변동이 증가할 때 실제 감소하는 결과를 보였다. 또한, 수요의 변동이 증가할 때 전체 재고 중 안전재고의 비율이 감소되는 것도 보였다. 더 나아가서 수요 변동의 크기가 어느 정도 이상으로 커지면 안전재고가 완전히 제거되는 사실도 입증하였다. 이 같은 결과는 제품수요의 변동이 매우 클 때 리드타임 수요의 변동을 줄이기 위한 전략은 별로 효용이 없음을 보여준다.

• Journal of Korean Institute of Industrial Engineers
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• v.27 no.4
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• pp.345-351
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• 2001

We are concerned with a multiple replenishment contract with a purchase price discount in a supply chain. The chain is composed of one supplier, one buyer and consumers for a product. The replenishment contract is based upon the well-known (s, Q) policy but allows contracting several firmed orders at a time with a price discount. Due to a larger forecast error of the future demand, the buyer should keep a higher level of safety stock to provide the same level of service of the usual (s, Q) policy but can reduce his purchase cost by placing larger quantity. Thus there exists a trade-off between the price discount and inventory holding cost. We present a model for the contract and an algorithm to find the optimum number of the firmed orders. Computer experiments show that the algorithm finds the global optimum solution very fast.

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2003.11a
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• pp.261-265
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• 2003

This paper proposes acceptance requirements and the corresponding implementation strategy for the near-surface repository of low- and intermediate-level radioactive wastes. The proposed requirements include details on waste classification and radionuclide concentration limitation and inventory analysis. The strategy considers a relevant linking between predisposal waste management, disposal safety assessment and the overall disposal system.

• Journal of the Ergonomics Society of Korea
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• v.35 no.6
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• pp.611-619
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• 2016

Objective:This study aims to analyze the relationships between personality factors measured by Minnesota Multiphasic Personality Inventory (MMPI) scales and the indices of safety and health in the shipbuilding industry. Background: Many researches reported that there were significant relationships between some MMPI subscales and traffic and industrial accidents. Method: This study analyzes 230 male workers in shipyard for their MMPI scores gathered during recruitment process and their safety and health indices from the performance record during their working period. ${\chi}^2-test$ and one-way ANOVA are used for finding the statistical significance for personality factors. The conventional grouping rule for MMPI scales and other grouping criteria considering the attitude of positive answer for the MMPI test during recruitment process are used for analysis. Results: The Hypomania (Ma) and Psychopathic Deviate (Pd) scales of the MMPI are the main factors related to the safety and health related indices for most grouping rules. Depression (D), Psychasthenia (Pt), Hypochondriasis (Hs), Schizophrenia (Sc), and Masculinity and Femininity (Mf) scales are also related to the safety and health indices. Conclusion and Application: The results can be used for understanding the psychological factors in human behaviors and safety and can help professional personnel take the necessary steps in improving safety on the job and also in providing the effective teaching of safe work methods.

• Journal of Oriental Neuropsychiatry
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• v.31 no.2
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• pp.63-76
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• 2020

Objectives: The purpose of this study was to verify the clinical effects of herbal medicines on patients with depressive disorder. Methods: A prospective observational study on patients with depressive disorder was conducted. The patients were treated with herbal medicines for eight weeks. The Korean Hamilton Depression Rating Scale (K-HDRS) was evaluated as the primary outcome and the Korean Beck's Depression Inventory (K-BDI), Instrument on Pattern Identification for Depression, Korean Symptom Checklist-95 (KSCL-95), Insomnia Severity Index (ISI), Korean State-Trait Anxiety Inventory (STAI-K), Korean State-Trait Anger Expression Inventory (STAXI-K), EuroQol five-dimensional Questionnaire (EQ-5D), Minnesota Multiphasic Personality Inventory-2 (MMPI-2), Heart Rate Variability (HRV) were measured as the secondary outcome. Adverse events were assessed for safety. Results: A total of 35 participants were observed for 12 weeks. The K-HDRS improved significantly in four, eight, and 12 weeks and the K-BDI showed significant differences in four, and eight weeks. There were no significant improvements in other evaluation scales. Gyejibongnyeong-hwan was the most frequently and continuously prescribed, showing significant improvements of K-HDRS after eight weeks of treatment. Conclusions: In our observational study, herbal medicine was effective for relieving the depression of patients with depressive disorder and Gyejibongnyeong-hwan showed the most significant effectiveness.

• Nuclear Engineering and Technology
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• v.45 no.2
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• pp.179-190
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• 2013

A station blackout experiment called SBO-01 was performed at the ATLAS facility. From the SBO-01 test, the station blackout scenario can be characterized into two typical phases: A first phase characterized by decay heat removal through secondary safety valves until the SG dryouts, and a second phase characterized by an energy release through a blowdown of the primary system after the SG dryouts. During the second phase, some physical phenomena of the change over a pressurizer function, i.e., the pressurizer being full before the POSRV $1^{st}$ opening and then its function being taken by the RV, and the termination of normal natural circulation flow were identified. Finally, a core heatup occurred at a low core water level, although under a significant amount of PZR inventory, whose drainage seemed to be hindered owing to the pressurizer function by the RV. The transient of SBO-01 is well reproduced in the calculation using the MARS code.

• Nuclear Engineering and Technology
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• v.39 no.4
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• pp.257-272
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• 2007

Supercritical water-cooled reactors (SCWRs) are recognized as a Generation IV reactor concept. The Super LWR is a pressure-vessel type thermal spectrum SCWR with downward-flow water rods and is currently under study at the University of Tokyo. This paper reviews Super LWR safety. The fundamental requirement for the Super LWR, which has a once-through coolant cycle, is the core coolant flow rate rather than the coolant inventory. Key safety characteristics of the Super LWR inhere in the design features and have been identified through a series of safety analyses. Although loss-of-flow is the most important abnormality, fuel rod heat-up is mitigated by the "heat sink" and "water source" effects of the water rods. Response of the reactor power against pressurization events is mild due to a small change in the average coolant density and flow stagnation of the once-through coolant cycle. These mild responses against transients and also reactivity feedbacks provide good inherent safety against anticipated-transient-without-scram (ATWS) events without alternative actions. Initiation of an automatic depressurization system provides effective heat removal from the fuel rods. An "in-vessel accumulator" effect of the reactor vessel top dome enhances the fuel rod cooling. This effect enlarges the safety margin for large LOCA.

• The Journal of Internal Korean Medicine
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• v.35 no.2
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• pp.145-156
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• 2014

Objectives : The aim of this study was to compare Tianwangbuxin-dan to Fluoxetine for antidepressive efficacy and safety in poststroke depression (PSD). Methods : A randomized, double blinded, non-inferiority trial was conducted. 113 PSD patients were recruited from a stroke center. Except for the 25 excluded patients, 88 PSD patients were randomly given either Tianwangbuxin-dan 1100 mg or Fluoxetine 20 mg per a day for 16 weeks. PSD was evaluated using Beck's depression inventory (BDI) and Hamilton depression rating scale (HDRS) and followed every fourth week. Repeated measure analysis of variance (ANOVA) was used to compare and contrast the depression scores of the two groups and to compare them among the evaluation times, at the beginning, $4^{th}$, $8^{th}$, $12^{th}$ and $16^{th}$ weeks. In addition, independent t-tests were used to find the difference between two groups at every evaluation time. Results : Finally, 88 PSD patients were included in the study, 63 PSD patients completed the procedure and 25 PSD patients were dropped out by the incompliance or withdrawal of consent. Tianwangbuxin-dan (or Fluoxetine) improved the depression of stroke patients and the efficacy of Tianwangbuxin-dan was not inferior to that of Fluoxetine. In addition, there was no significant side effect in two groups. Conclusions : This study showed that antidepressive efficacy and safety of Tianwangbuxin-dan in PSD patients.

• Safety and Health at Work
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• v.9 no.1
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• pp.101-108
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• 2018

Background: Work and work environment have a critical influence on adolescent workers' health. They are subjected to more risks than adults. The aim of this study is to examine psychological health outcomes in adolescent workers in the areas of depression, somatization, anxiety, hostility, and negative self-concept, and to investigate any related factors. Methods: This is a descriptive and cross-sectional study. Research samples were collected from adolescent workers between 15 and 18 years old attending a 1-day mandatory education course at vocational training centers, working 5 days per week in small enterprises. Data were collected using the following instruments: Brief Symptom Inventory, Multidimensional Scale of Perceived Social Support, and Descriptive Characteristics of Children's Assessment Form. Results: The investigation covers 837 young workers, of whom 675 were males and 162 were females. The majority of the families had low incomes (68.1%). Overall, 33.5% of the adolescents had been hospitalized because of health problems. Their average weekly working hours were $78.1{\pm}10.7$. Almost 50% of adolescent workers scored above the mean average in the Brief Symptom Inventory, indicating serious pschological health symptoms. Those who scored high for hostility, depression, negative self-concept, anxiety, and somatization were between 45.4% and 48.9% of the sample. Logistic regression analysis was conducted to determine the underlying factors: a perception of "feeling very bad" health conditions was 2.07-fold whereas the rate of "no annual leave" was 0.73-fold, and both were found to be effective on psychological problems. Conclusion: In this study, it seems likely that psychological health problems are the result of multiple adverse factors including working conditions, annual leave, and health considerations.

• Journal of Oriental Neuropsychiatry
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• v.33 no.4
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• pp.389-400
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• 2022

Objectives: Depression is a highly prevalent disease, and the market for antidepressant drugs continues to grow at a steady rate. Although current antidepressants are reported to be effective, because of their low remission rate and side effects, new antidepressants are needed. The use of Banhahubak-tang (BHT) to treat the symptoms of depression is supported by experimental evidence. The proposed study will evaluate the efficacy and safety of BHT in treating depression. Methods: A randomized, waitlist-controlled, parallel clinical trial will be conducted to assess the efficacy of BHT in depression. A total of 84 participants with depression will be randomized into the intervention group or waitlist-control group at a 1:1 ratio. Patients in the intervention group will be administered BHT three times a day for four weeks and followed up for four more weeks after therapy completion. Patients in the waitlist-control group will undergo the same intervention and follow-up after a four-week waiting period. The primary outcome is change in the Korean version of the Hamilton Depression Rating Scale (K-HDRS) scores for major depressive disorders after four weeks. The secondary outcomes include scores on the K-HDRS, Korean Symptom Check List 95 (KSCL-95), Insomnia Severity Index (ISI), State-Trait Anxiety Inventory-Korean version (STAI-K), State-Trait Anger Expression Inventory-Korean version (STAXI-K), and the Instrument on Pattern Identifications for Depression and EuroQol-5 Dimension (EQ-5D). Conclusions: This trial will provide high-quality clinical evidence of the efficacy and safety of BHT in the management of depression.