• Journal of the Korean Operations Research and Management Science Society
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• v.42 no.2
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• pp.19-34
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• 2017

In this study, we develop an optimal sourcing strategy considering compensation orders to mitigate the supply chain disruption risks. We considered two-echelon supply chain consisting of a single buyer and multiple suppliers who have fixed transaction cost and probabilistic disruption risks. Under this setting, we provide the joint optimization method to determine the number of suppliers and the order quantities. Through numerical examples, we provide managerial implications on the sourcing strategy by investigating changes in the order quantities and the number of suppliers due to the degree of supply chain disruption risks.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.18 no.34
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• pp.15-23
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• 1995

We study how to determine backorder cost at the warehouse in a one-warehouse/N-retailer distribution system such that channel efficiency (minimizing total system costs) is improved. We define backorder costs as compensation that the warehouse pays to the retailer for the number or orders delayed due to stockout at the warehouse. We answer two questions : (1) "Should the warehouse compensate for his backorder\ulcorner" and (2) "Is there any equilibrium for both the warehouse and retailer while they are seeking for their own profits\ulcorner" We show that : (1) "The warehouse should pay backorder costs for the sake of channel efficiency." and (2) "There exists an equilibrium that is infiuenced by the amount of compensation." First, we prove the existence of a mutually acceptable equilibrium for both the warehouse and the retailer, which is different from Nash equilibrium because they independently maximize their respective profits with incomplete information about each other. Second, we prove that the equilibrium moves to a point such that channel efficiency is improved if the warehouse compensates the retailers for his backorders. We show the existence of an optimal compensation that minimizes total system costs. Third, we show that the amount of optimal compensation increases as the ratio of mean lead time for the warehouse to that for the retailer increases.ouse to that for the retailer increases.

• Journal of the Korean Society for Nondestructive Testing
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• v.25 no.1
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• pp.1-8
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• 2005

This paper presents the experimental results measured by photoelastic 4-step phase shifting method for the isochromatic fringe distribution in a TV glass panel. In the conventional photoelastic method, the isochromatic fringe orders are measured manually point by point. The 4-step phase shifting method uses four images obtained from a circular polariscope by rotating the analyzer to $0^{\circ},\;45^{\circ},\;90^{\circ}$, and $135^{\circ}$. In order to use the 4-step phase shifting method, the elements of a polariscope should be aligned to isoclinic direction at a point and/or along a line where isochromatic fringe distribution is measured. Experimental results obtained from the 4-step phase shifting method are compared with those measured by the Senarmont compensation method. Both results are well agreed. Then, isochromatic fringe distributions in the TV glass panel that is heat-treated before and after are compared. Maximum and minimum isochromatic fringe orders in the TV glass panel with before- and after-heat treatment are changed approximately two times.

• Investigative Magnetic Resonance Imaging
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• v.10 no.2
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• pp.70-80
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• 2006

Spin echo gradient moment nulling pulse sequences were designed and implemented on a clinical magnetic resonance imaging system. A new technique was introduced for flow compensation that minimized echo time and effectively suppresses unwanted echoes on the slice selection gradient axis in spin echo sequences. A unified gradient shape was used in all orders of flow compensation up to the third order. A dual-purpose gradient was applied for flow compensation and to reduce unwanted artifacts. The sequences were used to generate images of phantoms and/or human brains. This technique was especially good at reducing eddy currents and artifacts related to imperfection of the refocusing pulse. The developed sequences were found to have shorter echo times and better flow compensation in through-plane flow than those of the previous models that were used by other investigators.

• Journal of Intelligence and Information Systems
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• v.27 no.1
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• pp.177-190
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• 2021

Due to the development of the fourth industrial revolution technology, efforts are being made to improve areas that humans cannot handle by utilizing artificial intelligence techniques such as machine learning. Although on-demand production companies also want to reduce corporate risks such as delays in delivery by predicting total production time for orders, they are having difficulty predicting this because the total production time is all different for each order. The Theory of Constraints (TOC) theory was developed to find the least efficient areas to increase order throughput and reduce order total cost, but failed to provide a forecast of total production time. Order production varies from order to order due to various customer needs, so the total production time of individual orders can be measured postmortem, but it is difficult to predict in advance. The total measured production time of existing orders is also different, which has limitations that cannot be used as standard time. As a result, experienced managers rely on persimmons rather than on the use of the system, while inexperienced managers use simple management indicators (e.g., 60 days total production time for raw materials, 90 days total production time for steel plates, etc.). Too fast work instructions based on imperfections or indicators cause congestion, which leads to productivity degradation, and too late leads to increased production costs or failure to meet delivery dates due to emergency processing. Failure to meet the deadline will result in compensation for delayed compensation or adversely affect business and collection sectors. In this study, to address these problems, an entity that operates an order production system seeks to find a machine learning model that estimates the total production time of new orders. It uses orders, production, and process performance for materials used for machine learning. We compared and analyzed OLS, GLM Gamma, Extra Trees, and Random Forest algorithms as the best algorithms for estimating total production time and present the results.

• Journal of Power Electronics
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• v.17 no.6
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• pp.1553-1562
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• 2017

For the purpose of enhancing the performance of the shunt active power filter (APF), this paper presents a novel Fast Weighted Compound Control (FWCC) strategy based on the synchronous frame. In this control strategy, the proposed new repetitive controller can work faster and more stably by reducing the internal model cycle and introducing a damping coefficient. In addition, the harmonic detector can be removed to simplify the structure of the APF owing to the improvements. Furthermore, a proportional-integral (PI) controller is added to work in parallel with the repetitive controller by using a weighted ratio. Then, a convergence speed analysis and design algorithm are given in detail. Simulation and experimental results show that the harmonic distortion is reduced from 2.91% to 1.89%. In addition, the content for each of the characteristic harmonic orders has decreased by more than three times.

• International conference on construction engineering and project management
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• 2022.06a
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• pp.1240-1240
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• 2022

Construction projects are fraught with risks from cost or other overruns to accidents along with other issues. This is true whether the relevant organization is an owner, general contractor, CM, specialty-trade contractor, or other entity. When cost issues or other issues confront arise, how should an organization proceed whether attempting to gain additional compensation in terms of cost/other damages or protecting the same against such claims if they do not appear to be warranted? Enter construction cost forensics. This presentation will focus on strategies/techniques with construction cost forensics in these areas in order to be successful. Covered techniques include those to develop and analyze claims including fundamental construction cost analysis techniques. When an unexpected event disrupts a construction project, using sound analytical methods to identify the cause and quantify the extent of the issue will be important for negotiating a fair result or for obtaining a successful outcome in arbitration or litigation. Key examples of uncovering issues via construction cost forensics will be covered in this presentation.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.40 no.1
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• pp.1-8
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• 2016

In this study, we propose a control algorithm for Inertially Stabilized Platforms (ISP), which combines Disturbance Observer (DOB) with conventional proportional integral derivative (PID) control algorithm. A single axis ISP system was constructed using a direct drive motor. The joint friction was modeled as a nonlinear function of joint speed while the accuracy of the model was verified through experiments and simulation. In addition, various Q-filters, which have different orders and relative degrees of freedom (DOF), were implemented. The stability and performance of the ISP were compared through experimental study. The performance of the proposed PID-plus-DOB algorithm was compared with the experimental results of the conventional double loop PID control under artificial vehicle motion provided motion simulator with six DOF.

• Journal of the Korean Society for Library and Information Science
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• v.57 no.3
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• pp.27-48
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• 2023

This study aims to investigate the impact of job stress on the job satisfaction and life satisfaction of local government officials who participated in the reading academy from January 2023 to March 2023. The research involved collecting 300 questionnaires and conducting multiple regression analysis to analyze the obtained data. The results of the study are presented below. Impact of Job Stress on Job Satisfaction: The analysis revealed that among the sub-factors of job stress, inappropriate compensation significantly increases job stress among local government officials in the reading academy. Moreover, the study found that turnover intention was particularly high when compensation was not recognized as appropriate, indicating it as the most significant source of job stress. Impact of Job Stress on Life Satisfaction: The findings demonstrate that several factors negatively influence job stress, leading to reduced life satisfaction among local government officials in the reading academy. These factors include undesirable changes in working conditions or situations, anxiety about reorganization, inconsistent work orders, gender discrimination, and an authoritative organizational atmosphere. Effect of Job Satisfaction on Life Satisfaction: The analysis of the relationship between job satisfaction and life satisfaction indicated that turnover intention and remuneration level in job satisfaction positively influenced emotional satisfaction. Conversely, the job itself and interpersonal relationships had a significant negative effect on emotional satisfaction. Furthermore, the job itself and the level of remuneration in job satisfaction showed a significant positive effect on physical satisfaction. Similarly, the job itself and the level of remuneration in job satisfaction positively affected social satisfaction, while the intention to change jobs had a significant negative impact.

• Ocean and Polar Research
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• v.31 no.1
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• pp.97-110
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• 2009

Two of the most important topics of the 21st century are ensuring harmony between man and his environment and the emerging long-tail economy in which niche markets are becoming increasingly more important. Since the Industrial Revolution in 17th century, human beings have increasingly exploited the world's natural capital, such as the natural environment and its ecosystems. Now the world is facing limits to sustainable economic growth because of limits to this natural capital. Thus, most countries are beginning to adopt a new development paradigm, the so-called"Green Development Paradigm" which pursues environmental conservation in parallel with economic growth. Recently, the Korean government announced an ambitious national policy of Low Carbon & Green Growth for the next six decades. This is an important step that transforms the existing national policy into a new future-oriented one. The fisheries sector in particular has great potential for making a substantial contribution to this national policy initiative. For example, the ocean itself with its sea plants and phytoplankton has an enormous capacity for fixing carbon, and its vast areas of tidal flats have a tremendous potential for cleaning up pollutants from both the sea and the land. Furthermore, the fishing industry has great potential for the development of fuel-saving biodegradable technologies, and a long-tail economy based on digital technologies can do much to promote the production and consumption of green goods and services derived from the oceans and the fisheries. In order for this potential to be realized, the fisheries authority needs to develop a new green-growth strategy that is practical and widely supported by fishing communities and the markets, taking into account the need for greenhouse gas reduction, conservation of the ocean environment and ecosystems, an improved system for seafood safety, the establishment of strengthened MCS (monitoring control surveillance) system, and the development of coastal ecotourism. In addition, fisheries green policies need to be implemented through a well-organized system of government aids, regulations and compensation, and spontaneous (voluntary) orders in fishing communities should be promoted to encourage far more responsible fisheries.