• Land and Housing Review
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• v.7 no.3
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• pp.157-164
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• 2016

Recently, the paradigm of land development has been transformed from the joint development to the step-by-step development due to changes in socio-economic conditions. Nevertheless, the introduction of large-scale transportation facilities such as new transportation system tends to employ the joint development. Although new transportation system is eco-friendly, it occasionally fails at the beginning of the project because of high installation cost. Such phenomenon is caused by not only the system did not reflect the local characteristics but also did not respond to the step-by-step development. Accordingly, in order to introduce transportation system rationally, introducing new methods corresponding to the step-by-step development should be sought. In this study, we assumed that large-scaled land development site be achieved step-by-step development. and suggested the need for a phased introduction through benefit-cost analysis. The findings illustrated that the phased introduction shows economic efficiency with 30% increase of B/C compared to the bulk introduction. It also demonstrates that the bulk introduction under step-by-step development is more efficient than the bulk introduction under joint development.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.41 no.12
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• pp.1969-1977
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• 2016

We study the connection time of vehicle-to-mobile roadside unit (V2MR) communications which can reduce the significant cost of the fixed RSU by installing a gateway of mobile network into a transit bus called the mobile RSU. In the V2MR communications, the connectivity of a commute vehicle can be improved via ad-hoc connection to a nearby mobile RSU. In this paper, we present a new analysis model to estimate the connection time between a commute vehicle and a mobile RSU, when there is a bus station in the overlapping route. Since the connection time between two vehicles is highly dynamic and unpredictable, our analysis will provide a fundamental basis of connection-time estimation of V2MR communications. Numerical results obtained from VEINS simulation show that our analysis can estimate the connection time of V2MR communications with the average error below 1.0 percent. Moreover, we show that the average connection time of V2MR communications can be extended to approximately 3.85 times of that of V2R communications.

• Korean Security Journal
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• no.39
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• pp.295-317
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• 2014

In advanced country, private investigation system is made up of private security and in domestic, there is growing need constantly to introduce private investigation but it is not passed until now in assembly so a messenger office which is run illegally is growing because of demand by subdividing business areas. That is a proof that both the police and private security don't meet demand of public peace to the public. that's why the police has own businesses like a investigation, traffic, intelligence, crime prevention and private security's business areas are limited like a facilities security, escort security, protection of a person, machine security, special security as the Private Security Act. This study attempts to know structural difference between private security system and private investigation system in case private investigation system becomes one of the private security. on some question, respondents reply like that private security and private investigation is very different(71.2%), different(22.4%), average(6.3%), similar(0.0%), very similar(0.0%). the result seems like respondents recognize private security and private investigation as different businesses. In the result of non-quantity analysis, the differences seem like a business character, expense, business scope, public power, scale of organization, object of threat, legislation. In domestic, effort to legislate private investigation system has undergone difficulty since congressman Ha Soon Bong's motion in 1999 and today, congressman Yoon Jae Ok's All Amendments Private Security Act and congressman Song Young Geun's Private Inveswtigation Act are pending in assembly. This study's result is intended for examining difference in exploration between private security and private investigation and then there is going to propose to the policy in case private investigation system is passed in assembly by amending Private Security Act like congressman Yoon Jea Ok's All Amendment Private Security Act.

• Journal of Korea Spatial Information System Society
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• v.2 no.2 s.4
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• pp.25-37
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• 2000

As computer systems of high capacity and high performance recently emerged, various researches about GISs(Geographic Information Systems) have been in progress and many GIS applications have also been developed. From the domestic situation where many people are using mobile devices, because of the recent advances in the mobile technology, we can infer that the time will come when every individual will carry a mobile device with a GPS(Global Positioning System) module resulting from the development of a miniature GPS Module. Therefore, a mobile GIS that can allows users to deal with dynamic GIS data management and perform their tasks while moving will be required. This paper discusses the design and implementation of a mobile GIS using the shareware DBMS, called postgresSQL. The Mobile GIS in which a mobile concept is utilized at the GIS data server makes it possible to insert, delete, update GIS data, to zoom in and zoom out displayed maps, and to locate the user's position on the client device. Therefore, It is possible to manage dynamic GIS data in order to deal with GIS data on the maps while moving, connect various GIS data servers through the middleware, and connected with ITS (Intelligent Transport System) which is one of applications of the Mobile GIS developed in this paper.

• Journal of Korean Home Economics Education Association
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• v.19 no.3
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• pp.19-36
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• 2007

The purpose of this study is to identify the consumer roles-gainer, allocator, buyer, user and disposer- of middle school students. The methodology that has been applied to this study was an ethnography study based on in-depth interviews with ten middle schoolers selected in Changwon, Gyeongnam. The result of this study is as follows; First, as gainers, teenagers usually gained their money from their parents. Because this tends to be not periodical, allowance education should be performed to both parents and teenagers. Second, as allocators, teenagers allocated most of their money in entertaining, shopping, traveling, leaving small amount of money for saving. Thorough education supported by school and home should be held for efficient and balanced allocation of acquired allowance. Third, teenagers as buyer should be encouraged to examine carefully in their buying goods and services thus increasing their ability in solving problems related to consume. Fourth, due to the fact that teenagers' role as user is very feeble, educations related to usually consumed products and consuming environments should be strengthened. Fifth, N generation's internet-based character is reflected in disposer rules so education for better disposal in internet world should be needed. Conclusively, education for teenagers' role as consumer will be efficient is linked with school, home, and society thus providing better standard for consumers.

• Journal of the Korea institute for structural maintenance and inspection
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• v.19 no.6
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• pp.95-102
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• 2015

Recently, the maintenance activity for aging of bridge structures was difficult because of traffic jam, environment pollution and increasing cost. And to solve these problems, modular bridge research has been studied. After static and cyclic loading test was conducted for serviceability and bending performance with one way slab, effective moment of inertia of modular specimen was analyzed to estimate the deflection by KCI(2012). To conduct the test, one integral slab and three modular slabs were made for static loading and one integral and modular slab were made for cyclic. As a result of the test, the modular slab had the similar bending performance of the integral. But the ultimate deflection showed the insufficient which was smaller than 20%. In the cyclic loading test, the modular slab has different behavior of deflection with the integral, so it was evaluated difficult for serviceability. In addition, effective moment of inertia by KCI(2012) was not estimated for modular slab with connection. The new value of m which was ratio between moments is 4.53 based on result of test for predicting deflection of modular.

• Journal of Korean Tunnelling and Underground Space Association
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• v.15 no.5
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• pp.537-546
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• 2013

Traffic congestion in existing tunnels has increased due to increased traffic volume and enlarged vehicles. Enlarging existing tunnels has advantages over constructing new tunnels by reducing land purchasing costs as well as minimizing natural environment destruction. In fact, many overseas projects for enlarging existing tunnels have been reported. Thus, it appears that the demand on enlarging existing tunnels continues to rise in Korea in near future. Nonetheless, the studies related to the enlarged tunnels have been relatively rare since there have been few tunnel enlargement projects in Korea. In the present study, the tunnel behavior and the stability of rock pillar when enlarging existing parallel tunnels were investigated by performing FE analysis and using existing theory and empirical relationships. Four different enlarging cases, depending on the enlargement types and directions, were examined in the study. According to the results, for the tunnels with the same pillar width after enlarged, the uni-laterally enlarged tunnel indicated 5 to 20% higher crown settlement compared to the bi-laterally enlarged tunnel, and for the tunnel with the narrowest pillar, the highest shotcrete stress was observed. Also, the strength/stress ratio for rock pillar was more than 1.0 for all four enlargement cases, and the Matsuda's method was found to give higher strength/stress ratio by about 50% compared to the Peck's method.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.10 no.6
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• pp.140-146
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• 2011

As the demand of Variable Message Sign(VMS) has become pervasive in fulfilling the ITS policy, the costs of maintaining the Variable Message Sign operation have also increased. This paper proposes the U-curved figure, the C-curved figure and the ventilated figure type for aerodynamic drag reduction on Variable Message Sign and shows the analysis of aerodynamic drag effects using Flow Analysis. As a results of the flow analysis for right-angled, 45 degrees from side to side and 45 degrees from up or down, the C-curved figure and the ventilated figure type show about 30% aerodynamic drag reduction in all direction. And the U-curved figure type shows vivid aerodynamic drag reduction for right-angled and 45 degree from side to side, but trivial aerodynamic drag reduction for 45 degree from up or down. It is possible to reduce not only the damage on Variable Message Sign due to typhoon because of the aerodynamic drag reduction, but also installation constraints because of lighter Variable Message Sign support structure by appling the proposed structure and analysis in this paper.

• Journal of Navigation and Port Research
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• v.34 no.5
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• pp.397-404
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• 2010

The Currently, most cargos of container transshipment between Busan Port and New Port are transported over land, and the rest is transported by barge. This study estimated firstly the traffic between those ports through simulations in order to analyze the feasibility of container transshipment by barge. It forecasted annual profitability using determinants to affect on the barge business by the traffic, and then, discussed the feasibility. This study supposed the flexible scenarios with 50%, 60%, 80%, or 100% transshipment and the 25 monthly barge service numbers between two ports, and measured the influences of different factors according to the above various scenarios. And then the sales were evaluated by the different traffics and freights scenarios provided the business would be actually operated. Finally, Net incomes were simulated to analyze the feasibility of different scenarios by various traffics and freights. The net income should be positive to get the feasibility. To achieve this, the minimum traffic should be secured and the lowest freight per TEU should be determined. While all countries of the world is controlling CO2 emissions and emphasizes the green logistics, this study contributed to solve at the same time the problems about the pollution and the efficiency of transportation by reviewing positively the feasibility of barge transportation as an alternative to transportation overland.

• Journal of Korea Port Economic Association
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• v.37 no.1
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• pp.71-85
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• 2021

A variety of methods have been proposed through a number of studies on sophisticated demand forecasting models that can reduce logistics costs. These studies mainly determine the applicable demand forecasting model based on the pattern of demand quantity and try to judge the accuracy of the model through statistical verification. Demand patterns can be broadly divided into regularity and irregularity. A regular pattern means that the order is regular and the order quantity is constant. In this case, predicting demand mainly through regression model or time series model was used. However, this demand is called "intermittent demand" when irregular and fluctuating amount of order quantity is large, and there is a high possibility of error in demand prediction with existing regression model or time series model. For items that show intermittent demand, predicting demand is mainly done using Croston or HOLTS. In this study, we analyze the demand patterns of various items of air cargo with intermittent patterns and apply the most appropriate model to predict and verify the demand. In this process, intermittent optimal demand forecasting model of air cargo is proposed by analyzing the fit of various models of air cargo by item and region.