• The Journal of the Korea Contents Association
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• v.20 no.5
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• pp.525-535
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• 2020

This study aims to evaluate the economic value of the heat wave watch/warning (HW/W) forecast provided by the KMA (Korea Meteorological Administration) for the public sector. Local govermenments of Korea currently use the HW/W forecasts as a major input variable to determine the preparative requisite level for reducing potential damage by extreme heat events. To assess the value of the HW/W, which is not a marketable commodity, a decision-making model taking into account the cost and loss was established. The 'cost' variable was defined as the heat wave countermeasures budget for Seoul and Busan in 2016, and the 'loss' variable was set as the amount of health insurance claims for those 65 and older obtained from the Health Insurance Review and Assessment Service. Using this model, the value of the HW/W in 2016 was calculated as KRW 4,133M and KRW1,090M for Seoul and Busan, respectively. In addition, if the KMA reduces the False Alarm of the HW/W by a single instance, the value will be increased by KRW 76.6M and KRW 16.8M for the two cities. The results of this study are useful in quantitatively estimation of the value of the HW/W forthe public sector.

• Journal of the Korean Operations Research and Management Science Society
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• v.12 no.1
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• pp.111-111
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• 1987

With the increasing interest of reducing process variation, statistical process control has served the pivotal tool in most industrial quality programs. In this study, system analyses have been performed associated with a cost incorporated version of a process control, a quadratic loss-based X over bar control chart model. Specifically, two issues, the capital/research investments for improvement of a system and the precision of a parameter estimation, have been addressed and discussed. Through the analysis of experimental results, we show that process variability is seen to be one of the most important sources of loss and quality improvement efforts should be directed to reduce this variability. We further derive the results that, even if the optimal designs may be sensitive, the model appears to be robust with regard to misspecification of parameters. The approach and discussion taken in this study provide a meaningful guide for proper process control. We conclude this study with providing general comments.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 1993.10a
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• pp.31-39
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• 1993

This paper considers a procedure for the economic design of a cumulative score(CUSCORE) control chart and more sensitive than X-type control chart for small shift to control the mean of a process with a exponentially distributed quality characteristic. An expected loss - cost model as a function of design variables(sample size, sampling interval, scoring limit and decision limit) is derived. Direct search techniques are used to optimize the model subject to ARL in control. Numerical examples and sensitivity analysis of the model are presented. For selected values of situation parameters a comparison study with CUSUM charts is given. CUSCORE control charts compare favourably with CUSUM charts in cost for speedy production process. The proposed control chart can be directly applied for controlling the lifetime characteristics.

• Journal of applied mathematics & informatics
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• v.12 no.1_2
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• pp.251-260
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• 2003

Generally, in deriving the solution of economic production quantity (EPQ) inventory model, we consider the demand rate and deterioration rate as constant quantity. But in case of real life problems, the demand rate and deterioration rate are not actually constant but slightly disturbed from their original crisp value. The motivation of this paper is to consider a more realistic EPQ inventory model with finite production rate, fuzzy demand rate and fuzzy deterioration rate. The effect of the loss in production quantity due to faulty/old machine have also been taken into consideration. The methodology to obtain the optimum value of the fuzzy total cost is derived and a numerical example is used to illustrate the computation procedure. A sensitivity analysis is also carried out to get the sensitiveness of the tolarance of different input parameters.

• IE interfaces
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• v.23 no.1
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• pp.12-23
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• 2010

A semiconductor market is one of the most competitive markets in the world. To survive this competition, important targets for production planning are on-time delivery and profit maximization. In our research, we modify the linear programming model for the current production planning by adding new objective functions that maximize the profit. In addition, we propose a production planning process that gives a priority to new products, reflecting daily fluctuations in demand to weekly production planning. We validate our model with real data sets obtained from a major company semiconductor manufacturer and performed the paired t-test to verify the results. The results showed that our model forecasted profit and loss with 93.2% accuracy and improved the due date satisfaction by 10%.

• The Journal of Information Systems
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• v.24 no.2
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• pp.189-208
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• 2015

Purpose While individuals have unique abilities for planned behavior, they also often act irrationally. In this study, we draw on myopic loss aversion perspective as a meta-theoretical lens to explain why mobile applications users have inertia from updating their applications, ultimately leading them to use current version of applications. Design/methodology/approach Based on a survey of 219 users, this study conducts its research model using partial least square analysis and also demonstrates that both subconscious triggers (habit and anxiety) of system 1 thinking and conscious triggers (sunk cost and transition cost) of system 2 thinking promotes user's inertia, thus leading to the willness to continue use current versions. Findings By grounding the research model in the combination of both status quo bias and dual information processing theory from the behavioral economics, this study provide an alternative theoretical lens to describe why mobile users hesitate to update their applications. The results of this research show that all triggers have significant impacts on inertia. This study also found that the relationship between inertia and willingness to continue to use current version was positively significant.

• Nuclear Engineering and Technology
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• v.52 no.7
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• pp.1429-1435
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• 2020

Applying an accurate parametric prediction model to identify abnormal or false pressurizer water levels (PWLs) is critical to the safe operation of marine pressurized water reactors (PWRs). Recently, deep-learning-based models have proved to be a powerful feature extractor to perform high-accuracy prediction. However, the effectiveness of models still suffers from two issues in PWL prediction: the correlations shifting over time between PWL and other feature parameters, and the example imbalance between fluctuation examples (minority) and stable examples (majority). To address these problems, we propose a cost-sensitive mechanism to facilitate the model to learn the feature representation of later examples and fluctuation examples. By weighting the standard mean square error loss with a cost-sensitive factor, we develop a Cost-Sensitive Long Short-Term Memory (CSLSTM) model to predict the PWL of PWRs. The overall performance of the CSLSTM is assessed by a variety of evaluation metrics with the experimental data collected from a marine PWR simulator. The comparisons with the Long Short-Term Memory (LSTM) model and the Support Vector Regression (SVR) model demonstrate the effectiveness of the CSLSTM.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.29 no.4C
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• pp.550-558
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• 2004

In order to design network node for guaranteeing availability against network based DoS attack, some restrictions such as the relationship analysis on upper and lower layer bandwidth, buffer capacity, attack resources, a number of attack session and loss probability are analyzed. And then, to make good use of network resource, the relationship between required resources for satisfying loss probability and cost is discussed. The results of this study are expected to be applied to the effective security node design against network DoS.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.18 no.1
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• pp.94-100
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• 2008

Noise barriers are being used more often to solve problems of noise pollution from traffic noise. Several types of noise barriers are being installed to increase the cost-effectiveness of noise barrier installation. In this study, the insertion loss is analyzed to evaluate the effectiveness of the noise barrier by using the BEM. In order to check the validity of the BEM, the BEM and Lam's theoretical analysis are compared with measurement, which is performed in the anechoic chamber for the 1/10 scale-down model, and good agreements are obtained. By using the two dimensional boundary element method, the insertion loss is calculated and analyzed for several typical noise barriers such as the vertical barrier, the barrier with an oblique edge on top, the T-shaped barrier and the barrier with interference device on top. With these analyses, it is possible to design more cost-effective noise barriers appropriate for a particular area.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.12 no.1
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• pp.135-158
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• 2018

High-Speed vehicles can be considered as multiple mobile nodes that move together in a large-scale mobile network. High-speed makes the time allowed for a mobile node to complete a handover procedure shorter and more frequently. Hence, several protocols are used to manage the mobility of mobile nodes such as Network Mobility (NEMO). However, there are still some problems such as high handover latency and packet loss. So efficient handover management is needed to meet Quality of Service (QoS) requirements for real-time applications. This paper utilizes the cross-layer seamless handover technique for network mobility presented in cellular networks. It extends this technique to propose QoS-aware NEMO protocol which considers QoS requirements for real-time applications. A novel analytical framework is developed to compare the performance of the proposed protocol with basic NEMO using cost functions for realistic city mobility model. The numerical results show that QoS-aware NEMO protocol improves the performance in terms of handover latency, packet delivery cost, location update cost, and total cost.