• Title/Summary/Keyword: Inventory models

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Component Procurement Planning with Demand Uncertainty Under Assemble-to-Order Environments (불확실한 수요를 갖는 주문 조립 환경에서의 부품 조달 계획에 관한 연구)

  • Lee, Geun-Cheol;Kim, Jung-Ug;Hong, Jung Man
    • Korean Management Science Review
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    • v.29 no.3
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    • pp.121-134
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    • 2012
  • In this study, we consider a component procurement planning problem where the procurement amounts of components are determined under assemble-to-order systems with demand uncertainty. In the problem, procurement amount of each component is decided before the demands of finished products are known and after the demands are identified the assembly amounts of the finished products are decided. In this study, the objective function of the problem is minimizing the total costs which are composed of purchase and inventory costs of the components and the backorder costs of the finished products. We assume that the uncertain demand information is given as multiple scenarios of the demands, and we propose procurement planning methods based on stochastic models which considering the multiple demand scenarios. To evaluate the performances of the proposed methods, computational experiments were carried out on the proposed methods as well as benchmarks including a method based on deterministic mathematical model and a heuristic. From the results of the computational tests, the superiorities of the proposed methods were shown.

Development of paint area estimation software for ship compartments and structures

  • Cho, Doo-Yeoun;Swan, Sam;Kim, Dave;Cha, Ju-Hwan;Ruy, Won-Sun;Choi, Hyung-Soon;Kim, Tae-Soo
    • International Journal of Naval Architecture and Ocean Engineering
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    • v.8 no.2
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    • pp.198-208
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    • 2016
  • The painting process of large ships is an intense manual operation that typically comprises 9-12% of the total shipbuilding cost. Accordingly, shipbuilders need to estimate the required amount of anti-corrosive coatings and painting resources for inventory and cost control. This study aims to develop a software system which enables the shipbuilders to estimate paint area using existing 3D CAD ship structural models. The geometric information of the ships structure are extracted from the existing shipbuilding CAD/CAM system and used to create painting zones. After specifying the painting zones, users can generate the paint faces by clipping structural parts inside each zone. Finally, the paint resources may be obtained from the product of the paint areas and required paint thickness. Implementing the developed software system to real shipbuilders' operations has contributed to improved productivity, faster resource estimation, better accuracy, and fewer coating defects over their conventional manual calculation methods for painting resource estimation.

Review of Self-Administered Instruments to Measure Cultural Competence of Nurses - Focused on IAPCC · CCA (간호사의 문화적 역량 측정도구에 대한 고찰 - IAPCC와 CCA를 중심으로)

  • Chae, Duck Hee;Kang, Kyeong Hwa
    • Journal of Korean Academy of Nursing Administration
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    • v.19 no.1
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    • pp.48-62
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    • 2013
  • Purpose: As Korean society has rapidly become multicultural in the last few decades, it is essential for nurses to become culturally competent to provide effective care for ethnically and culturally diverse populations. Considering the advantages of standardized instrument, there is a need to evaluate current cultural competence instruments to assess adaptability to Korean nurses. Methods: Using Macdowell's instrument evaluation guideline, a review and evaluation was done of the Inventory for Assessing the Process of Cultural Competence among Healthcare Professionals (IAPCC) and Cultural Competence Assessment (CCA), which were both developed based on cultural competence theoretical models and have been commonly used in nursing research. Two other Korean instruments were also evaluated. Results: The instruments reviewed have limitations in reliability and validity, as well as cultural background and development process, for measurement of cultural competence in Korean nurses. Conclusion: The results of this study indicate that it is necessary to discuss and agree on a definition of what cultural competence is and to develop instruments to measure cultural competence in Korean nurses.

Calculation of The Core Damage & FP Release Behavior for The PHEBUS FPT0 Similar to Cold Leg Break Accident Using MELCOR

  • Park, Jong-Hwa;Cho, Song-Won;Kim, Hee-Dong
    • Proceedings of the Korean Nuclear Society Conference
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    • 1996.05b
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    • pp.637-642
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    • 1996
  • This paper presents the analysis results for the core degradation processes and the fission product release of the PHEBUS FPT0 experiment using MELCOR1.8.3. The objective of this study is to assess models associated with the core damage and fission product behavior in MELCOR. The calculation results were much improved through sensitivity studies. Thermal/hydraulic behavior in the core and the circuit was well predicted under the intact core geometry. In non-eutectic model case. the UO$_2$ dissolution model in the MELCOR always showed such a tendency that the resulting dissolved UO$_2$ mass was small at the highly oxidized condition due to the model logic. Total H$_2$ generation mass was underpredicted because the stiffner was not modeled and the liner in the shroud was not allowed to be oxidized in MELCOR. Some difficulties were found in modeling the activation product were solved by manipulating the RN input associated with the initial fission product inventory. These problem were occurred because there are no control rod model in MELCOR. Generally the fission product release ratio showed a similar trend compared with the measured data except the activation product. which have no model to simulate in MELCOR.

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Control Theory and Managerial Accouting (통제이론(統制理論)과 관리회계(管理會計))

  • Byun, Yong-Hwan
    • Korean Business Review
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    • v.1
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    • pp.249-271
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    • 1987
  • Applicability of control theories to the efficient operation of accounting system is studied in this paper. Since managerial accounting has been developed along the progrees of control theory, management control theories are essential to explain important attributes of diverse accounting system. Basic concept of control is studied in depth and control systems are classified on the base of their special characteristics. And then the applicability of those control methods to accounting systems are discussed based on behavioral as well as management science approach. In the management science approach, accounting control models of production management, inventory management and R&D are designed with its unique quantitative characteristics. It, however, is very difficult to implement quantified control standards on the behavioral management side. Since most of variables considered on behavioral approach are non-quantitative, only discussion of the theoratical definition has been a main issue on previous studies. In this paper, practicability of the behavioral approach to the accounting control system is studied analyzing state variables and behavior variables of the control system. Theoratical base of the discussion are provided from control theories developed in organization theory and Economics. Basic objective of accounting control practice is to control qualitative human behavior represented by quantified figures while quantitative methods are prevailing over general accounting practice. Therefore, this paper tried to develope and integrate accounting control systems applicable to the behavioral management area as well as management science control side.

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Review of Quick Response: Investigation on its Fundamental Role of Supply Chain Collaboration

  • RYU, Chungsuk
    • Journal of Distribution Science
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    • v.17 no.9
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    • pp.5-13
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    • 2019
  • Purpose - This study investigates the key features of Quick Response as the fundamental form of supply chain collaboration by reviewing the selected past studies. Based on the findings from the literature review, this study provides the guideline for future researchers and business practitioners who search for more advanced collaboration programs. Research design, data, and methodology - This study conducts the literature review on the past studies that had researched Quick Response. The selected studies are analyzed in terms of how to represent Quick Response in the models and which issue to address. Results - This study finds that the past studies lack a unified concept of Quick Response, and they fail to provide the consistent guideline on how to run this program in practices. The literature review also shows that only a small number of research issues has been addressed by most researchers. Conclusions - On the purpose of figuring out the real value of Quick Response, this study suggests that future studies apply its extensive application to the entire supply chain system. This study also shed light on the potential of Quick Response to be a more advanced supply chain collaboration program with additional collaborative functions other than information sharing.

Data Mining-Aided Automatic Landslide Detection Using Airborne Laser Scanning Data in Densely Forested Tropical Areas

  • Mezaal, Mustafa Ridha;Pradhan, Biswajeet
    • Korean Journal of Remote Sensing
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    • v.34 no.1
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    • pp.45-74
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    • 2018
  • Landslide is a natural hazard that threats lives and properties in many areas around the world. Landslides are difficult to recognize, particularly in rainforest regions. Thus, an accurate, detailed, and updated inventory map is required for landslide susceptibility, hazard, and risk analyses. The inconsistency in the results obtained using different features selection techniques in the literature has highlighted the importance of evaluating these techniques. Thus, in this study, six techniques of features selection were evaluated. Very-high-resolution LiDAR point clouds and orthophotos were acquired simultaneously in a rainforest area of Cameron Highlands, Malaysia by airborne laser scanning (LiDAR). A fuzzy-based segmentation parameter (FbSP optimizer) was used to optimize the segmentation parameters. Training samples were evaluated using a stratified random sampling method and set to 70% training samples. Two machine-learning algorithms, namely, Support Vector Machine (SVM) and Random Forest (RF), were used to evaluate the performance of each features selection algorithm. The overall accuracies of the SVM and RF models revealed that three of the six algorithms exhibited higher ranks in landslide detection. Results indicated that the classification accuracies of the RF classifier were higher than the SVM classifier using either all features or only the optimal features. The proposed techniques performed well in detecting the landslides in a rainforest area of Malaysia, and these techniques can be easily extended to similar regions.

SAFETY ANALYSIS METHODOLOGY FOR AGED CANDU® 6 NUCLEAR REACTORS

  • Hartmann, Wolfgang;Jung, Jong Yeob
    • Nuclear Engineering and Technology
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    • v.45 no.5
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    • pp.581-588
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    • 2013
  • This paper deals with the Safety Analysis for $CANDU^{(R)}$ 6 nuclear reactors as affected by main Heat Transport System (HTS) aging. Operational and aging related changes of the HTS throughout its lifetime may lead to restrictions in certain safety system settings and hence some restriction in performance under certain conditions. A step in confirming safe reactor operation is the tracking of relevant data and their corresponding interpretation by the use of appropriate thermal-hydraulic analytic models. Safety analyses ranging from the assessment of safety limits associated with the prevention of intermittent fuel sheath dryout for a slow Loss of Regulation (LOR) analysis and fission gas release after a fuel failure are summarized. Specifically for fission gas release, the thermal-hydraulic analysis for a fresh core and an 11 Effective Full Power Years (EFPY) aged core was summarized, leading to the most severe stagnation break sizes for the inlet feeder break and the channel failure time. Associated coolant conditions provide the input data for fuel analyses. Based on the thermal-hydraulic data, the fission product inventory under normal operating conditions may be calculated for both fresh and aged cores, and the fission gas release may be evaluated during the transient. This analysis plays a major role in determining possible radiation doses to the public after postulated accidents have occurred.

Effect of Working Capital Management on the Profitability of Steel Companies on Vietnam Stock Exchanges

  • PHAM, Kien Xuan;NGUYEN, Quang Ngoc;NGUYEN, Cong Van
    • The Journal of Asian Finance, Economics and Business
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    • v.7 no.10
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    • pp.741-750
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    • 2020
  • This study examines the influence of working capital management (WCM) factors on the profitability of steel companies listed on the Stock Exchange of Vietnam. Data was collected from audited financial statements of companies for a period of 10 years, from 2010 to 2019. The number of samples eligible for research is 20 out of 26 companies, which is equivalent to 76.9%. With the help of dedicated software Stata version 14, the impact determination of WCM (through 8 independent variables: DIO, DPO, DSO, CCC, SIZ, CR, LEV, GRO) to the firm's profitability (through the dependent variable) is performed through multivariate regression models. Research results from companies in the steel industry in Vietnam during this period indicate that WCM has a strong impact on the profitability of businesses. Among 8 factors affecting the profitability of steel enterprises, factors DPO, DIO, DSO, CR, SIZ, GRO have a positive impact, boosting profitability; 2 factors CCC and LEV have a negative impact on profitability; in which, the effect of CCC is negligible. This conclusion is almost in contrast to many previously published studies due to the specifics of the industry as well as the different stages of economic development associated with the economic management policies of the State.

The Effect on a Delivery Time Window Dispatching Policy for 3PL Distribution Center (제3자 물류센터 납품시간창 디스패칭 정책에 관한 효과)

  • Lee, Woon-Seek;Kim, Byung Soo
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.37 no.1
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    • pp.60-67
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    • 2014
  • This paper considers an inbound ordering and outbound dispatching problem for multi-products and multi-vehicles in a third-party distribution center. The demands are dynamic over a discrete and finite time horizon, and replenishing orders are shipped in various transportation modes and the freight cost is proportional to the number of vehicles used. Any mixture of products is loaded onto any type of vehicles. The objective of the study is to simultaneously determine the inbound lot-sizes, the outbound dispatching sizes, and the types and numbers of vehicles used to minimize total costs, which consist of inventory holding cost and freight cost. Delivery time window is one of the general dispatching policies between a third-party distribution center and customers in practice. In the policy, each demand of product for a customer must be delivered within the time window without penalty cost. We derive mixed integer programming models for the dispatching policy with delivery time windows and on-time delivery dispatching policy, respectively and analyze the effect on a dispatching policy with delivery time windows by comparing with on-time delivery dispatching policy using various computational experiments.