• Journal of Korean Society of Industrial and Systems Engineering
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• v.40 no.4
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• pp.253-259
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• 2017

Recent development in science and technology has modernized the weapon system of ROKN (Republic Of Korea Navy). Although the cost of purchasing, operating and maintaining the cutting-edge weapon systems has been increased significantly, the national defense expenditure is under a tight budget constraint. In order to maintain the availability of ships with low cost, we need accurate demand forecasts for spare parts. We attempted to find consumption pattern using data mining techniques. First we gathered a large amount of component consumption data through the DELIIS (Defense Logistics Intergrated Information System). Through data collection, we obtained 42 variables such as annual consumption quantity, ASL selection quantity, order-relase ratio. The objective variable is the quantity of spare parts purchased in f-year and MSE (Mean squared error) is used as the predictive power measure. To construct an optimal demand forecasting model, regression tree model, randomforest model, neural network model, and linear regression model were used as data mining techniques. The open software R was used for model construction. The results show that randomforest model is the best value of MSE. The important variables utilized in all models are consumption quantity, ASL selection quantity and order-release rate. The data related to the demand forecast of spare parts in the DELIIS was collected and the demand for the spare parts was estimated by using the data mining technique. Our approach shows improved performance in demand forecasting with higher accuracy then previous work. Also data mining can be used to identify variables that are related to demand forecasting.

• Journal of the Korean housing association
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• v.16 no.5
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• pp.13-19
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• 2005

It is estimated that 2.25 million households accounting for $13.5\%$ of total households will have home networking in 2025. As the need for intelligence and sustainability of residential environment has been increasing, the growing demand for intelligent house is obvious. The purpose of this study was to investigate the perception of consumers on digital home and their needs. A web-survey was conducted and the survey participants were limited to residents living in housing built after 2003. A total of 120 responses were used for data analysis. The images of digital home were categorized into environmental friendliness, convenience, and sophistication. Also the respondents showed the strong need for functions of digital home such as safety from emergency and entertainment.

• The Journal of Fisheries Business Administration
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• v.29 no.2
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• pp.97-110
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• 1998

This paper tries to estimate Korea's import demand function for fisheries using cointegration analysis. The estimation function consists of one dependent variable-import quantity of fisheries(FTIW) and two independent variables-relative price(RP) between importable and domestic products and real income(GDP). As it has been empirically found out that almost all of time series of macro-variables such as GDP, price index are nonstationary, existing studies which ignore this fact need to be reexamined. Conventional econometric method can not analyze nonstationary time series in level. To perform the analysis, time series should be differenciated until stationarity is guaranteed. Unfortunately, the difference method removes the long run element of data, and so leads to difficulties of interpretation. But according to new developed econometric theory, cointegration approach could solve these problems. Therefore this paper proceeds the estimation on the basis of cointegration analysis, because the quartly variables from 1988 to 1997 used in the model is found out to be nonstationary. The estimation results show that all of the variables are statistically significant. Therefore Korea's import demand for fisheries has been strongly affected by the variation of real income and the relative price.

• Journal of Applied Reliability
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• v.3 no.1
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• pp.13-40
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• 2003

The seasonal adjustment is an essential process in analyzing the time series of economy and business. One of the powerful adjustment methods is X11-ARIMA Model which is popularly used in Korea. This method was delivered from Canada. However, this model has been developed to be appropriate for Canadian and American environment. Therefore, we need to review whether the X11-ARIMA Model could be used properly in Korea. In this study, we have applied the method to the annual sales of refrigerator sales in A electronic company. We appreciated the adjustment by result analyzing the time series components such as seasonal component, trend-cycle component, and irregular component, with the proposed method. Additionally, in order to improve the result of seasonal adjusted time series, we suggest the demand forecasting method base on autocorrelation and seasonality with the X11-ARIMA PROC.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.16 no.2
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• pp.13-22
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• 2017

The present study proposes a new methodology for predicting the demand for truck rest areas beside national highways. Previous demand forecasting methods were reviewed first in order to complement them with additional items. The results of the study are as follows. In the demand forecasting process, the primary task is to divide parking demands of trucks into short-term parking and long-term parking. Since short-term and long-term parking vary in utilization, congestion, and turnover rate, different influence factors should be considered according to parking time. Furthermore, the demand characteristics of rest and convenience facilities need to be reflected as well, because they in turn affect the demand for truck rest areas. In sum, the demand forecasting process for destination-type truck rest areas on national highways requires more attention than that for truck rest areas on expressways, and possible influences of various factors should be examined in this process.

• Journal of Information Technology Applications and Management
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• v.10 no.2
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• pp.61-71
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• 2003

Ad-hoc networks are characterized by multi-hop wireless links, frequently changing network topology and the need for efficient dynamic routing protocols. In an Ad-hoc network, each host assumes the role of a router and relays packets toward final destinations Because a packet is broadcast to all neighboring nodes, the optimality criteria of wireless network routing is different from that of wired network routing. tn this paper 1 point out the more important cost factor than the number of links in the Ad-hoc network. A class routing protocols called on-demand protocols has recently found attention because of their low routing overhead since it performs a blind flooding to look for a path. In this paper, 1 propose the method which reduces overhead by using the information of neighboring nodes and doing a selective flooding. Simulation results demonstrate better reduction of routing overheads with this scheme.

• Journal of Korean Institute of Industrial Engineers
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• v.31 no.3
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• pp.228-239
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• 2005

In this paper, we propose a new conceptual HVRPCR(Heterogeneous Fleet Vehicle Routing Problem with Customer Restriction) model including additional restrictions that are consisted of loadage limit and possible visit number of demand post in HVRP. We propose HVRPCR algorithm using the heuristic in order to solve speedily because VRP is NP-Hard and need many solution time. The proposed model is simulated with changing demand post location, demand weight, loading and possible visit number limitation. Results of the computational experiment are provided along with some analysis like travel cost reduction rate.

• Journal of the Korean Home Economics Association
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• v.41 no.5
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• pp.149-163
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• 2003

The deteriorated apartments make a social problem in now a days. After all a new alternative plan for deteriorated apartments such as the remodelling concept must be considered. This study aims to survey the needs levels among residents in deteriorated apartments relating to remodelling. It might provide the basic data which could be used for the analysis of consumers in the future implementation of deteriorated remodelling projects. The analytical methods applied for this study were t-test, one-way ANOVA, post-hoc estimation(Scheff test) by the SPSS 10.1 for Windows program. The analysis of the need levels for the areas of remodelling, by the family characteristic variable, residence value viewpoint, and residence satisfaction level, indicated that the demand level for ‘equipment ’was the highest, followed by the order of ‘structure’ and ‘interior’. The need levels for ‘security’, ‘parking lot’, ‘public facilities in apartment block’, and ‘landscape’ were generally low but in the group of high income, the need levels were comparatively high.

• Health Policy and Management
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• v.28 no.3
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• pp.202-209
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• 2018

Health care has two different facets. One is commodity and another is a right of human being. Health care as a commodity is utilized by demand approach in market. Demand is determined by economic factors such as price and income. From the last third of the 19th century until the early 1920s, priority of sickness insurance was replacing the income that workers lost as a result of illness and injury. By the 1920s, the capacity of applied biological and medical science was remarkably developed. Development of medical science stimulated the cost of medical care, and the burden of increased medical care cost required new role of medical care security system. In 1942, Beveridge report was published in United Kingdom, and health care was considered as a right of human being. In 1948, United Nations declared heath care as a right in the Universal Declaration of Human Right. In most countries introduced new medical care security policy based on health care as a right. The viewing health care as a commodity must be shifted toward need based care as a right. Need were understood to rest on demographic, epidemiological, scientific, and medical knowledge factors. Bring needed care to the population could best be achieved institutionally by a hierarchy of provider organizations, guided by planning bodies, which would provide comprehensive benefits. In Korea, health care in social health insurance (SHI) is considered as a commodity not a right. However, health policies under SHI must be need approach based on health care as a right. Mismatch between health policies and ideology of SHI made big troubles. It is important to realize ideology of SHI for good health policies.

• Journal of Korean Society of Transportation
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• v.27 no.4
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• pp.103-113
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• 2009

Quick accident spot reaching of 119ERU is the most important role in decrease of accident depth. If 4 minutes of wounded person pass after cardiac arrest, brain damage is begun. and If 10 minutes of wounded person pass after cardiac arrest, possibility to die rises. Accordingly, when establish 119ERU, need to consider travel time to traffic accidents spot. This treatise groped a facility location problem using SCLM and minisum location problem mutually. And existent minisum location problem has a problem that maximum travel time exceed $\lambda$. ERU to need in present situation and also can reduce average travel time. so this treatise propose modified minisum location problem. In case applying modified minisum location theory, 119ERU can arrive all demand and that is optimized about demand and travel time. Can minimise figure of 119 first aids to need in present situation applying this way, and also can reduce average passing time. Finally, this way can minimise figure of 119ERU to need in present situation and also can reduce average travel time.