• Title/Summary/Keyword: Inventory analysis

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A Study on Risk Assessment of GHG Inventory Verification (온실가스 인벤토리 검증의 위험성평가에 대한 연구)

  • Lee, Kang-Bok;Kim, Geon-Ho;Lee, Seung-Hwan;Lee, Eun-Sook
    • Proceedings of the Safety Management and Science Conference
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    • 2009.11a
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    • pp.203-208
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    • 2009
  • Government and company are unfolding greenhouse gas reduction activity to prevent the effects of global warming. Also, verification business through greenhouse gas inventory construction is spreaded variously. Greenhouse gas verification proceeds by document examination, risk analysis, field survey. Document investigates emission information, calculation standard, emission report, data management system. And through risk assessment result, establish field verification plan. Through study on risk assessment of greenhouse gas inventory verification, wish to reduce risk of verification.

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Optimal Inventory Policy in Beer Distribution Game (Beer Distribution Game에서의 최적 재고정책)

  • 조면식;김현수
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.24 no.65
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    • pp.11-22
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    • 2001
  • Recently, many studies on the supply chain management have been published due to increasing attention placed on the design and performance analysis of the supply chain as a whole. Using the Beer distribution game introduced in Sterman[1995], we develop a simple order-up-to-R inventory model to minimize sum of the inventory holding cost and shortage cost under probabilistic demand. We show that performance of the model is robust through extensive simulation experiment. Applying the model to serially connected supply chain, we observe that, if the unit shortage cost is relatively high, R value computed independently is an optimal solution.

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A Study on Emotional Characteristics Using Upper Gastrointestinal Endoscopic Findings and The Core Seven Emotions Inventory-Short Form (상부위장관내시경 소견과 핵심칠정척도 단축형을 활용한 정서적 특성 연구)

  • Kim, Gwang Woo;Ko, Kyeong Jin;Han, Min Seok;Kang, Seong Hyeon;Kang, Hyung Won;Lyu, Yeoung Su
    • Journal of Oriental Neuropsychiatry
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    • v.33 no.1
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    • pp.21-31
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    • 2022
  • Objectives: To perform correlation analysis between the Core Seven Emotions Inventory-Short Form (CSEI-s), Beck Anxiety Inventory (BAI), Beck Depression Inventory (BDI), upper gastrointestinal symptoms, and gastroscopic findings and to compare emotional characteristics with upper gastrointestinal endoscopic findings. Methods: In this study, medical records of 38 participants who visited the hospital for examination purposes or complained upper gastrointestinal symptoms and completed the CSEI-s, BAI, BDI, and Questionnaire for upper gastrointestinal symptoms were analyzed using SPSS (Statistical Package for the Social Sciences) version 25.0. Frequency Analysis, Descriptive Analysis, Independent t-test, Mann-Whitney's U-test, and Correlation analysis were performed. Results: The upper gastrointestinal symptom group showed higher levels of anger, sorrow, depression, and anxiety than the asymptomatic group. On gastroscopy, the normal group had higher levels of Joy than the abnormal group. The reflux esophagitis group showed higher levels of thought, depression, sorrow, and anxiety than the non-reflux esophagitis group. Joy showed a negative correlation with BDI score. However, anger, depression, sorrow, BAI, and BDI score showed positive correlations. Conclusions: Results of this study suggest that CSEI-s can be used to treat patients with upper gastrointestinal symptoms and reflux esophagitis.

Effect of System Operator on Dynamic Multi-Stage Inventory Problems (System operator가 다단계재고동적(多段階在庫動的) system 에 미치는 영향(影響)에 관(關)한 연구(硏究))

  • Kim, Man-Sik
    • Journal of Korean Institute of Industrial Engineers
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    • v.3 no.1
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    • pp.39-47
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    • 1977
  • Most of the current literature on inventory theory has been devoted to the study of single stage models. A class of inventory problems which is of great interest is the multistage inventory system which involves a series and hierarchical sequence of stations. This study analyzes some aspect of the series type and multi-stage inventory system, using the fixed cycle ordering which bas a modificatory control function in the system equations. The objective of this study is to clarify the dynamic behavior of the system. The author has derived the theoretical formulas of variation of ordering quantity and stock fluctuation of each stage due to power spectral density function. Influence of parameters such as, (1) intensity of autocorrelation of demand sequence ($\lambda$), (2) forecasting exponential smoothing factors of each stage (${\alpha}_1,\;{\alpha}_2,\;{\alpha}_3$) and (3) production control factor of the 3rd stage ($\gamma$), as operators of the system on the variation of ordering quantity and stock fluctuation of the system. is also clarified. As a result of this study, the relations between the variation of ordering quantity, stock fluctuation and the parameters of the system, have been found. The principles and the theorical analysis presented here will be applicable to more complex type of discrete control systems in constructing the specific condition of the system to minimize inventory variances.

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Implement Semi-Product Commonization Design for Reduction of Inventory : Focusing on Concrete Pump Truck Frame Assemble Process (펌프카 재고 감축을 위한 반제품 공용화 설계 구현 : H사(社) 펌프카 프레임 조립 공정 중심으로)

  • Kim, Kyung-Hun;Park, Chan-Woong
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.43 no.4
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    • pp.142-149
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    • 2020
  • A manufacturing company should produce its products and make a profit to continue its management. With the adoption of a multi-category small-volume production system, manufacturers that produce concrete pump-cine products are carrying out improvement activities to increase their market share amid the business-to-customer business environment. However, the slump in the construction investment environment has led to a decline in sales of concrete pump trucks. The purpose of holding inventory is to prevent loss of sales opportunities with the rate of change in the sales plan, and reducing the rate of change in the product can reduce unnecessary inventory and, in order to realize this, the goal of reducing inventory can be achieved by reviewing the parts that can be designed for common use. Therefore, to reduce the inventory of concrete pump trucks, semi-finished publicization design is necessary. According to the analysis, the frame assembly process of the 32M model is common. Production capacity can be secured without loss of sales opportunity.

Study on the Validation of Sasang Urination Inventory (SUI) for Analyzing Pathophysiological Symptoms and Diagnosing Sasang Types (배뇨 소증 분석과 사상체질 진단을 위한 사상소변기능검사(SUI)의 타당화 연구)

  • Chae, Han;Lee, Seul;Park, Yu-Gyeong;Lee, Jeongyun
    • Journal of Sasang Constitutional Medicine
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    • v.33 no.3
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    • pp.16-28
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    • 2021
  • Introduction The Sasang Urination Defecation Inventory was developed to analyze Sasang-type specific pathophysiological clinical symptoms, and its revised Sasang Urination Inventory (SUI) illustrated its clinical usefulness in Sasang type differentiation. However, the correlation with established clinical measures for its concurrent validity were not provided yet. Methods Total of 48 healthy university students were recruited to response Urogenital Distress Inventory-6 (UDI-6) and Overactive Bladder Symptom Score (OABSS) of Western medicine along with the SUI of traditional Korean medicine. The correlation coefficients between UDI-6 and OABSS and SUI were acquired with Pearson's correlation, and Analysis of Variance (ANOVA) and Profile Analysis were used to analyze significant differences in SUI subscale profiles of each Sasang types. Results The SUI-HSS of urogenital hypersensitivity correlated positively with OABSS (r=0.442, p<0.01), and the SUI-DIS of urinary discomfort positively with UDI-6 (r=0.289, p<0.05). Interestingly, the SUI-total was correlated positively with age (r=0.326), height (r=0.318) and weight (r=0.304). The SUI-DIS for urinary discomfort of So-Yang (9.48±2.11) type was significantly (p<0.05) higher than that of Tae-Eum (7.2±2.90) type. And SUI subscale profiles of each Sasang type were significantly (Wilks' Lambda=0.792, F=2.723, p=0.034) distinctive to each other. Discussion The acceptable convergent validity of SUI was shown using established measures of urogenital symptoms. The SUI might be used as an objective traditional Korean clinical measure for Sasang type differentiation and urological patients.

Verification and validation of isotope inventory prediction for back-end cycle management using two-step method

  • Jang, Jaerim;Ebiwonjumi, Bamidele;Kim, Wonkyeong;Cherezov, Alexey;Park, Jinsu;Lee, Deokjung
    • Nuclear Engineering and Technology
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    • v.53 no.7
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    • pp.2104-2125
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    • 2021
  • This paper presents the verification and validation (V&V) of a calculation module for isotope inventory prediction to control the back-end cycle of spent nuclear fuel (SNF). The calculation method presented herein was implemented in a two-step code system of a lattice code STREAM and a nodal diffusion code RAST-K. STREAM generates a cross section and provides the number density information using branch/history depletion branch calculations, whereas RAST-K supplies the power history and three history indices (boron concentration, moderator temperature, and fuel temperature). As its primary feature, this method can directly consider three-dimensional core simulation conditions using history indices of the operating conditions. Therefore, this method reduces the computation time by avoiding a recalculation of the fuel depletion. The module for isotope inventory calculates the number densities using the Lagrange interpolation method and power history correction factors, which are applied to correct the effects of the decay and fission products generated at different power levels. To assess the reliability of the developed code system for back-end cycle analysis, validation study was performed with 58 measured samples of pressurized water reactor (PWR) SNF, and code-to-code comparison was conducted with STREAM-SNF, HELIOS-1.6 and SCALE 5.1. The V&V results presented that the developed code system can provide reasonable results with comparable confidence intervals. As a result, this paper successfully demonstrates that the isotope inventory prediction code system can be used for spent nuclear fuel analysis.

Validity and reliability of simplified subjective career success inventory for dental hygienist (치과위생사용 단축형 주관적 경력성공 측정도구의 타당도와 신뢰도)

  • Park, Soo-Auk;Cho, Young-Sik
    • Journal of Korean society of Dental Hygiene
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    • v.21 no.2
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    • pp.171-182
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    • 2021
  • Objectives: Recently, subjective career success has been used as a criterion for evaluating career success. The purpose of this study was to develop and evaluate a simplified subjective career success inventory for dental hygienists. Methods: Subfactors of the subjective career success inventory consisted of career satisfaction, employability, and job satisfaction. The validity and reliability of the existing tools were evaluated through the basic items composition, content validity index (CVI), preliminary survey, and main survey process according to dental hygienists. The preliminary survey was composed of 35 questions by verifying the content validity twice from the existing 63 questions, and the main survey was conducted with a total of 12 questions. Samples were conveniently extracted from dental hygienists with a clinical career of ≥3 years and surveyed online from March 12, 2020 to June 30, 2020. Data of 320 people were collected, of which 284 were finally analyzed. The validity and reliability were analyzed using SPSS 18.0 and AMOS 18.0 (p<0.05). Results: The subjective career success was a shortened inventory composed of nine questions, and the overall reliability was Cronbach's α=0.841. Using exploratory factor analysis, three factors were extracted. As a result of the confirmatory factor analysis, each measurement variable significantly explained the latent factor, and the fit of the model was appropriate. The fit of the model was appropriate for the structural equation model. Among the sub-factors of subjective career success, career satisfaction and job satisfaction had a significant effect on intention to stay (p<0.05). Conclusions: The simplified subjective career success inventory developed for dental hygienists was found was found to be a useful tool in terms of reliability and validity.

An Inventory Problem with Lead Time Proportional to Lot Size and Space Constraint (로트크기에 비례하는 리드타임과 공간 제약을 고려한 재고관리 정책)

  • Lee, Dongju
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.38 no.4
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    • pp.109-116
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    • 2015
  • This paper is concerned with the single vendor single buyer integrated production inventory problem. To make this problem more practical, space restriction and lead time proportional to lot size are considered. Since the space for the inventory is limited in most practical inventory system, the space restriction for the inventory of a vendor and a buyer is considered. As product's quantity to be manufactured by the vendor is increased, the lead time for the order is usually increased. Therefore, lead time for the product is proportional to the order quantity by the buyer. Demand is assumed to be stochastic and the continuous review inventory policy is used by the buyer. If the buyer places an order, then the vendor will start to manufacture products and the products will be transferred to the buyer with equal shipments many times. The mathematical formulation with space restriction for the inventory of a vendor and a buyer is suggested in this paper. This problem is constrained nonlinear integer programming problem. Order quantity, reorder points for the buyer, and the number of shipments are required to be determined. A Lagrangian relaxation approach, a popular solution method for constrained problem, is developed to find lower bound of this problem. Since a Lagrangian relaxation approach cannot guarantee the feasible solution, the solution method based on the Lagrangian relaxation approach is proposed to provide with a good feasible solution. Total costs by the proposed method are pretty close to those by the Lagrangian relaxation approach. Sensitivity analysis for space restriction for the vendor and the buyer is done to figure out the relationships between parameters.

Approximate Continuous Review Inventory Models with the Consideration of Purchase Dependence (구매종속성을 고려한 근사적 연속검토 재고모형)

  • Park, Changkyu;Seo, Junyong
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.38 no.4
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    • pp.98-108
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    • 2015
  • This paper introduces the existence of purchase dependence that was identified during the analysis of inventory operations practice at a sales agency of dealing with spare parts for ship engines and generators. Purchase dependence is an important factor in designing an inventory replenishment policy. However, it has remained mostly unaddressed. Purchase dependence is different from demand dependence. Purchase dependence deals with the purchase behavior of customers, whereas demand dependence deals with the relationship between item-demands. In order to deal with purchase dependence in inventory operations practice, this paper proposes (Q, r) models with the consideration of purchase dependence. Through a computer simulation experiment, this paper compares performance of the proposed (Q, r) models to that of a (Q, r) model ignoring purchase dependence. The simulation experiment is conducted for two cases : a case of using a lost sale cost and a case of using a service level. For a case of using a lost sale cost, this paper calculates an order quantity, Q and a reorder point, r using the iterative procedure. However, for a case of using a service level, it is not an easy task to find Q and r. The complexity stems from the interactions among inventory replenishment policies for items. Thus, this paper considers the genetic algorithm (GA) as an optimization method. The simulation results demonstrates that the proposed (Q, r) models incur less inventory operations cost (satisfies better service levels) than a (Q, r) model ignoring purchase dependence. As a result, the simulation results supports that it is important to consider purchase dependence in the inventory operations practice.