• Industrial Engineering and Management Systems
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• v.12 no.1
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• pp.23-29
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• 2013

This paper presents inventory models for fresh agriculture products with time-varying deterioration rate. Due to the particularity of fresh agriculture products, the demand rate is a function that depends on sale price and freshness. The deterioration rate increases with time and is assumed to be a time-varying function. In the models, the inventory cycle may be constant or variable. The optimal solutions of models are discussed for different freshness and the deterioration rate. The results of experiments show that the profit depends on the freshness and deterioration rate of products. With the increasing inventory cycle, the sale price and profit increase at first and then start decreasing. Furthermore, when the inventory cycle is variable, the total profit is a binary function of the sale price and inventory cycle. There exist unique sale price and inventory cycle such that the profit is optimal. The results also show that the optimal sale price and inventory cycle depend on the freshness and the deterioration rate of fresh agriculture products.

• Korean Management Science Review
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• v.31 no.2
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• pp.1-13
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• 2014

In almost all of the organizations, the cost for acquiring and maintaining the inventory takes a considerable portion of the management budget, and thus a certain constraint is set upon the budget itself. The previous studies on inventory control for each item that aimed to improve the fill rate, backorder, and the expenditure on inventory are fitting for the commercially-operated SCM, but show some discrepancies when they are applied to the spare parts for repairing disabled systems. Therefore, many studies on systematic approach concept considering spare parts of various kinds simultaneously have been conducted to achieve effective performance for the inventory control at a lower cost, and primarily, METRIC series models can be named. However, the past studies were limited when dealing with the probability distributions for representing the situation on demand and transportation of the parts, with the (S-1, S) inventory control policy, and so on. To address these shortcomings, the Continuous Time Markov Chain (CTMC) model, which considers the phase-type distributions and the (s, Q) inventory control policies to best describe the real-world situations inclusively, is presented in this study. Additionally, by considering the cost versus the system availability, the optimization of the inventory level, based on this model, is also covered.

• Korean Journal of Adult Nursing
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• v.24 no.1
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• pp.31-37
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• 2012

Purpose: This Study was to examine to applicability of the Maslach Burnout Inventory on measuring burnout of the nurses who works in Korean university hospitals. Methods: The sample included 200 nurses and nurse managers. We used 22-item Maslach Burnout Inventory to evaluate the reported burnout. We evaluated the convergent validity through the factor analysis, and evaluated the discriminant validity through the Pearson's correlation analysis. Also, we evaluated the reliability for three subscales of Maslach Burnout Inventory with the Cronbach's ${\alpha}$, which assesses the internal consistency. Results: Factor analysis revealed three factors being extracted from the 22-item Maslach Burnout Inventory, and item loading for each factor is higher than 0.5. Therefore, the Maslach Burnout Inventory demonstrated high convergent validity. Also, emotional exhaustion, personal accomplishment, and depersonalization showed low correlation leading to the conclusion that there was discriminant validity. The Cronbach's ${\alpha}$ coefficients in the 22-item Maslach Burnout Inventory and three subscales were higher than 0.7. Conclusion: Maslach Burnout Inventory can be used as a valid instrument to measure the burnout level of the nurses working in Korean university hospitals.

• Journal of the Korea Safety Management & Science
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• v.20 no.3
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• pp.37-46
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• 2018

According to enhancement of roles and functions of enterprises' distribution centers, recent trend of distribution centers are specialization and diversification which have generated lots of new distribution center building or expansion of the existing ones and led attention on stock transfer importance in case of distribution center relocation. This thesis is a study for how to reduce stock transfer leadtime in order to minimize business risk and how to increase inventory accuracy when stock ownership is transferred in case of distribution center relocation, and to provide inventory accuracy management methods and inventory in/out management types, detailed definition to evaluate level for inventory accuracy management and pros/cons by inventory in/out management type assuming 'the higher inventory accuracy before stock transfer, the shorter stock transfer leadtime when distribution center is relocated'. This thesis provides detailed procedure to secure an absolute stock transfer leadtime and process to confirm hugh inventory accuracy by stakeholders which should be sloved by Task Force Team for stock transfer in case of distribution center relocation.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.46 no.4
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• pp.93-100
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• 2023

In this paper, an alternative inventory policy that trades off the bullwhip effect at an upstream facility with cost minimization at a current facility, with the goal of reducing system wide total expected inventory costs, when external demand distributjon is autocorrelated, is considered. The alternative inventory policy has a form that is somewhere between one that completely neglects the autocorrleation and one that actively utilizes the autocorrelation. For this purpose, a mathematical model that allows us to evaluate system wide total expected inventory costs for a periodic review system is developed. This model enables us to identify an optimal inventory policy at a current facility that minimizes system wide total expected inventory costs by the best tradeoff of the bullwhip effect at an upstream facility with cost minimization at a current facility. From numerical experiments, it has been found that (i) when the autocorrelation is negative, the optimal policy is one that actively utilizes the autocorrelation, (ii) when the autocorrelation is small and positive, the optimal policy is one that neglects the autocorrelation, and (iii) when the autocorrelation is large and positive, the optimal policy is somewhere between one that actively utilizes the autocorrelation and one that neglect the autocorrelation.

• Journal of Oral Medicine and Pain
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• v.20 no.2
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• pp.385-397
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• 1995

The purpose of this study is to document the stress symptoms (Anxiety and depression) among dental students and the difference of stress level between classes and by gender. All students in dental college, Seoul National University, in the 1995 academic year, were tested with the Spielberger's State-Trait Anxiety Inventory and Beck Depression Inventory just before the first semestral examination when the stress levels of students are expected to be the highest. 303 students answered the test. The obtained results were as follows : 1. State Anxiety inventory scores of the second-year and first-year students were significantly higher than those of the fourth -year and third-year(p(0.01), and all classes showed mean state anxiety scores more than mild. 2. Trait Anxiety inventory scores of the second-year and first-year students were significantly higher than those of the third-year and forth-year(p(0.01), and all classes showed mean Trait Anxiety scores more than mild. 3. Beck Depression inventory scores of the second -year students were significantly higher than those of the third-year and fourth-year(p(0.01), and twenty two students(7.3%) among the fourth classes showed depression symptoms. 4. In the comparison of the mean scores of the State-Trait Anxiety Inventory and Beck Depression Inventory between male and female students, State Anxiety Inventory scores of the second-year female students were significantly higher than those of the second year male students(p(0.05), and there was no significant difference elsewhere.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.18 no.5
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• pp.237-244
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• 2018

The Smart Factory level of manufacturing factories of SMEs now lacks a system for grasping the accurate inventory amount associated with inventory movements in managing warehouses at the basic level. Also, it is difficult to manage accurate materials for loss of data due to worker manual work and production method due to experience. In order to solve this problem, in this paper, automatic acquisition of inventory to minimize manual work to grasp workers' Inventory and improve automation is done. In the smart warehouse management system using the IoT-based autonomous mobile module, the autonomous mobile module acquires the data of the inventory storage while moving through the line. In order to grasp the material of the Inventory storage, The Camera module recognizes the name of the inventory storage. And Then, If output matches, the data measured by the sensor is transferred to the server. This data can be processed, saved in a database, and real-time inventory quantity and location can be grasped in a web-based monitoring environment for administrators. The Real-time Automatic Inventory (RAIC) systems is reduce manual tasks and expect the effects of automated inventory management systems.

• Korea Journal of Hospital Management
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• v.3 no.1
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• pp.83-99
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• 1998

The purpose of this study is to investigate factors influencing the attitude and satisfaction with inventory management of hospitals. Data were collected from 344 employees in two hospitals located in Seoul and one hospital located in Choong-Chung Do, Korea, using a self-administered questionnaire. Items included in the self-administered questionnaire were hospital and socioeconomic characteristics of personnels such as the level of knowledge, practice, attitude, and satisfaction with inventory management of hospitals. Major findings were as follows; Job position was significantly associated with satisfaction with inventory management. According to age, sex, type of position and aptitude of personnel the level of positive attitude to and satisfaction with inventory management showed significant association. Generally, those who had higher level of knowledge and practice showed a higher tendency toward positive attitude of inventory management, except for those in medical support post. A higher tendency of satisfaction with inventory management was also observed, with the exception of personnel in nurse post. This study showed that major factors affecting attitude toward inventory management are level of knowledge and practice, and factors affecting satisfaction are job position and aptitude. The level of attitude and satisfaction explained by these factors were 46.8% and 12.2%, respectively. According to the results of this study, higher level of knowledge and practice, job position and aptitude appear to be essential for the implementation of effective inventory management. Factors affecting attitude and satisfaction of inventory management should be studied more in depth systematically so that other objective test and measurements can be developed.

• Journal of Korea Society of Industrial Information Systems
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• v.24 no.3
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• pp.1-21
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• 2019

The objective of this study is three-fold: to investigate the relationship between information technology (IT) investment and inventory turnover, using 98 U.S. firms spanning eleven years (from 1999 to 2009); to analyze the correlation of inventory turnover with firm and industry characteristics, where vertical integration and growth options are chosen to reflect the features of the firm's internal characteristics, and industry dynamism and industry concentration are selected to represent the industry's competitive environment; and to examine time trends in inventory turnover. The significant findings include the following: (i) both IT investment and growth options have a positive impact on inventory turnover; (ii), but vertical integration and industry concentration have a negative impact on inventory turnover; (iii) the impact of industry dynamism on inventory turnover positive; and (iv) the time trends in inventory turnover and 'adjusted inventory turnover' have been increased during the sample period from 1999 to 2009.

• Journal of the Korean Operations Research and Management Science Society
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• v.38 no.2
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• pp.95-115
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• 2013

In traditional inventory models, purchase prices of raw materials are assumed to be fixed and have no effect on the optimal choice of inventory policies. However, when purchase prices fluctuate continuously over time, inventory costs are heavily affected by purchasing prices. Risk-averse inventory model decides order quantity and ordering time by considering not just purchase prices but also the risk from the discrepancy between estimated prices and realized prices. In this paper, we propose a myopic inventory policy which incorporates price risk into deciding ordering time and quantities. While the existing risk-averse model has no mechanism to reallocate inventories already purchased for a specific future period, the revised one reallocates initial inventories of each period to other future periods so that it can avoid purchasing raw materials at high prices. Experimental results demonstrate that the revised model outperforms the existing one in respect of total cost and variability.