• Journal of Korean Society of Industrial and Systems Engineering
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• v.20 no.43
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• pp.25-36
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• 1997

The purpose of this paper is to structure a new integrated model that can minimize the total cost for the transportation and inventory systems between m origin points, where origin i has a supply of a commodity, such as distribution centers or warehouses, and n destination points, where destination j requires the commodity. In this case, demands of the destination points are assumed random variables which have a known probability distribution. We will find optimal distribution centers which transport the commodity to the destination points and suggest optimal inventory policy to the selected distribution center which find the optimal pair $$ and safety stock level that minimize total cost with back-ordered case. This new model is formulated as a 0-1 nonlinear integer programming problem. To solve the problem, this paper proposes heuristic computational procedures and program and provides numerical examples.

• Journal of information and communication convergence engineering
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• v.17 no.3
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• pp.198-204
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• 2019

In this study, the author introduces a supply-chain management (SCM) solution that connects suppliers, manufacturers, customers, and other companies within a transactional relationship to enable efficient inventory management and timely product supply, which ultimately maximizes corporate profits. This proposed solution exploits Fourth Industrial Revolution technologies, such as artificial intelligence (AI) and the Internet of Things (IoT), which provide solutions to complex management issues generated by the broader market. The goal of the current study was to develop an advanced and intelligent smart SCM solution that complies with logistics standards, to enhance the visibility, safety, and efficiency of a supply chain made up of manufacturers and suppliers. This smart SCM solution aims at maximizing corporate profits through efficient inventory management and timely supply of products, and solves the complex management problems caused by operating within a wide range of markets.

• Safety and Health at Work
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• v.9 no.3
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• pp.339-346
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• 2018

Background: Workplace bulling is a pervasive phenomenon with negative consequences for the health of victims and the productivity of organizations. The aim of this study was to measure the prevalence and forms of workplace bullying among employees working at the public health-care sector of Cyprus using the Greek version of Leymann Inventory of Psychological Terror (LIPT) instrument. Methods: A translation process was followed from the French to the Greek version of LIPT questionnaire. Test-retest reliability expressed by Pearson's correlation coefficient was 0.98 indicating excellent reproducibility. Internal consistency reliability assessed by Cronbach ${\alpha}$ coefficient was 0.87 suggesting high reliability. LIPT instrument was distributed among 403 employees working at the primary health-care setting and at the largest public hospital of Cyprus with response rate of 73.4%. Results: Women comprised the majority of participants (71.4%). Mean age was 43.3 years. Prevalence of workplace bulling according to Leymann's definition was 5.9%. Most common forms of bullying were "Being continuously interrupted" (17.2%) and "continuously being given new work assignments" (13.5%). Women were significantly more often exposed to at least one mobbing behavior than men within the previous year (49% vs. 35.7%, p = 0.038), whereas nurses were significantly exposed to at least one mobbing behavior as compared to physicians (53.3% vs. 31.4%, p = 0.004). Conclusion: This was the first study that examined the prevalence of workplace bullying in the public health-care sector by elaborating the Greek version of LIPT instrument. Results showed that workplace bullying is a common and complex phenomenon among health-care organizations.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.39 no.4
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• pp.7-14
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• 2016

Unlike most researches that focus on single manufacturer or single buyer, this research studies the cooperation policy for two participants of supply chain such as single vendor and single buyer. Especially, this paper deals with single vendor-single buyer integrated-production inventory problem. If the buyer orders products, then the vendor will start to make products and then the products will be shipped from the vendor to the buyer many times. The buyer is supposed to order again when the buyer's inventory level hits reorder point during the last shipment and this cycle keeps repeated. The buyer uses continuous review inventory policy and customer's demand is assumed to be probabilistic. The contribution of this paper is to present a mixed approach and derive its cost function. The existing policy assumes that the size of shipping batch from single vendor to single buyer is increasing, called Type 1, or constant, called Type 2. In mixed approach, the size of shipping batch is increasing at the beginning part of the cycle, and then its size is constant at the ending part of the cycle. The number of shipping for Type 1 and Type 2 in a cycle in mixed approach is determined to minimize total cost. The relationship between parameters, for example, the holding cost per product, the set up cost per order, and the shortage cost per item and decision variables such as order quantity, safety factor, the number of shipments, and shipment increasing factor is figured out via sensitivity analysis. Finally, it is statistically proved that the mixed approach is superior to the existing approaches.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.28 no.2
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• pp.117-124
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• 2005

This study tries to develop the models of measuring the level of product availability accommodated for features of specific customers dividing customers into VIP customers and general customers. Functions of costs that the models are composed of are cost of holding safety stock and cost of lost opportunities. The existing model of measuring the level of product availability which focused on cost of holding safety stock for VIP customers should be reinforced by considering cost of lost opportunities caused by general customers' quitting trades with a company. This study tries to present realistic solutions for problems in making decisions related to the total inventory. This study concludes that the model of the level of product availability meeting general customers' needs is more efficient according to increasing of a latent demand of the general customers who quit trades with a company and the cost of lost opportunities.

• Journal of Industrial Technology
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• v.20 no.A
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• pp.219-228
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• 2000

The determination of lot sizes in prevailing inventory problems has been made with constant safety stock over the planning horizon. But, it is more profitable to accommodate the safety stock to dynamically fluctuating demands. The objective of this paper is to study the method to determine the dynamic safety stock and lot sizing rules depending on the actual customer demands. The last period or highly fluctuating period during the consumption of a lot is the most critical one to stock-out. It means that such periods must be given more attentions. Some dynamic methods to control safety stock are proposed with viewpoints of the time, quantity, and time-quantity. Simulation results show that lot sizing methods with dynamic safety stock reduce about 10% of average total cost compared to those with constant safety stock.

• Journal of the Korea Safety Management & Science
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• v.13 no.1
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• pp.23-30
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• 2011

The purpose of this study was to examine the relationships between MMPI(Minnesota Multiphasic Personality Inventory) scale and safety and health related indices in the shipbuilding workmen. The MMPI scores of the 230 shipbuilding workmen applicants and their performance records regarding safety and health were analyzed through t-test and one-way ANOVA to obtain the following results; (1) applicants intended to show the positive characteristics of their personality, and this attitude reflected a decrease on T-scores of MMPI; (2) there were significant relationships between some MMPI subscales and safety & health related indices. These results can be used to provide baseline information for more effective accident prevention programs.

• Transactions of the Korean Society of Pressure Vessels and Piping
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• v.17 no.1
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• pp.18-27
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• 2021

This study aims to develop an improved evaluation technology for assessing CANDU-6 safety. For this purpose, the multiple steam generator tube rupture (mSGTR) followed by an unmitigated station blackout (SBO) in a CANDU-6 plant was selected as a hypothetical event scenario and the analysis model to evaluate the plant responses was envisioned into the MARS-KS input model. The model includes logic models for controlling the pressure and inventory of the primary heat transport system (PHTS) decreasing due to the u-tubes' rupture, as well as the main features of PHTS with a simplified model for the horizontal fuel channels, the secondary heat transport system including the shell side of steam generators, feedwater and main steam line, and moderator system. A steady state condition was successfully achieved to confirm the stable convergence of the key parameters. Until the turbine trip, the fuel channels were adequately cooled by forced circulation of coolant and supply of main feedwater. However, due to the continuous reduction of PHTS pressure and inventory, the reactor and turbine were shut down and the thermal-hydraulic behaviors between intact and broken loops got asymmetric. Furthermore, as the conditions of low-flow coolant and high void fraction in the broken loop persisted, leading to degradation of decay heat removal, it was evaluated that the peak cladding temperature (PCT) exceeded the limit criteria for ensuring nuclear fuel integrity. This study is expected to provide the technical bases to the accident management strategy for transient conditions with multiple events.

• Proceedings of the Safety Management and Science Conference
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• 2010.11a
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• pp.365-378
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• 2010

재고(inventory positions)가 늘어나고 거래량 수입이 줄어들 때, 금융시장과 신용상태에 따른 기업들 간의 자금조달 시장에서 스프레드(spreads)가 확대되고 있다. 이러한 현상은 기업들 간의 합병(mergers)이 활발하게 일어나면서 기업들 간의 경쟁이 감소한 후에는 줄어드는 것이 일반적인 현상이다. 주식으로 볼 때 변동성(volatility)이 낮은 기업에 비하여 변동성이 높은 기업들이 재고와 거래량 수입의 변화에 민감한 반응을 나타내고 있다.

• Proceedings of the Safety Management and Science Conference
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• 2001.05a
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• pp.185-188
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• 2001

Many production management systems for increasing productivity, minimizing inventory, keeping due dates and maximizing use of resources have been proposed, and GT, MRP and JIT are frequently used among these systems. The three systems have merits and demerits through comparing with each other. Because each system has mutual dependence, a hybrid production system is necessary for using their merits maximally. In this study, a hybrid production system is designed by combining GT, MRP and JIT, which is suitable in the domestic production system.