• Journal of Korean Society of Transportation
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• v.25 no.4
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• pp.123-133
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• 2007

This study analyzed whether a transit network with hierarchy is efficient or not, and if transit network hierarchy has cost efficiency, then which condition guarantees the efficiency of the transit network hierarchy. The authors modeled the total cost of the transit network and suggested the conditions in which the transit network hierarchy has cost efficiency through comparing the cost of the transit network with and without hierarchy. The efficiency of transit network hierarchy is guaranteed when the travel cost savings induced by using a higher hierarchy transit network is larger than the increasing non-travel cost, which is the sum of access cost, waiting cost, and operating cost, induced by the introduction of a higher hierarchy transit network. This result is consistent with common sense and with the concept of cost and benefit analysis. If a passenger traveling within the area divided by a higher hierarchy transit network uses only a lower hierarchy transit network and the passenger traveling out of the area divided by the higher hierarchy transit network uses both lower and higher hierarchy transit networks, the travel demand using the higher hierarchy transit network is inversely proportional to the square of the line spacing. This means that the transit network becomes more efficient and small increases of travel demand guarantee the efficiency of the transit network hierarchy as the connectivity of the network becomes higher. This result shows that transit networks have economies of aggregation. This study is the first analytical research on transit network hierarchy and is expected to be a basis for numerical research. However, numerical research should complement this study, since analytical research has some limitations for considering a real network.

• Journal of the Korean Society of Hazard Mitigation
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• v.8 no.6
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• pp.101-111
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• 2008

Hangang Parks have been played an important role as the source of various Civilian activities by providing a natural space near Han River ever since it was developed. Due to the local-heavy rain caused by recent climate change, the Hangang Parks tends to be easily overflowed. Evacuation of the park in emergency and its controlled system should be made for the sake of Civilian's safety. In this study, various basic data and several parameters were analyzed to simulate the hydraulic effect of Hangang Parks based on the outflow in $P1/4{\div}1/4^3$ Dam. Rising effects of flood water level were investigated through the one-dimensional and twodimensional numerical hydraulic models. Relationships of water level and travel time of flood between key station and centeral part of each park were also identified. It can be used to forecast the future flood water level of each individual park in Hangang Parks. Obtained results can be used to establish the rational plan of usage, management, citizen's safety, and emergency action plan of the Hangang Parks as the flood is occurred from the outflow of Paldang dam.

• Korean Security Journal
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• no.38
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• pp.33-56
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• 2014

This study is aim to make use of prevention of air terrorism and strengthen of air security in Korea. To achieve it. searching main feature in U.S aviation profiling. Aviation profiling in U.S used to Secure Flight, Screening Passengers by Observation Technique, Registered Travel Program. Through U.S Aviation Profiling, Prevention of air terrorism in Korea are as in the following. First, Through U.S Aviation Profiling, Information of terrorism constructed in advance and unification of constructed information. Second, Identifiying that institution exclusively for prevention of air terrorism. Third, Identifiying that human rights and privacy invasion to a minimun plan anout U.S aviation profiling. Finally, Identifiying that the spread of research development for prevention of air terrorism and strengthen of air security in Korea.

• Journal of Korean Society of Rural Planning
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• v.16 no.4
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• pp.61-75
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• 2010

Daily living area can be delimited differently depending on what area is to be focused. Based on regional interaction, the present study empirically analyzed the difference between living areas focusing on rural area and ones relying on urban area. We established two types of living areas in Busan-Ulsan mega city with different focus areas (rural versus urban), using travel OD data (2006). According to the result, the fonn of spatial clusters in urban living area differed from that of spatial clusters in rural area; the boundaries of living area were not fit to those of administrative areas in both types; and living areas in both types tended to extend over more than two administrative areas. The results cast some implications concerning spatial planning and policy for living area delimitation. First, since the spatial structure and interconnection of urban area differs to those of rural area, it is required to delimit living areas discriminatively depending on the objectives of the spatial plan. Additionally, the living area should be established more specifically and systematically by further subdividing the form of spaces depending on the objectives and types of the plan. Second, the administrative areas should be consolidated now that the difference of boundaries of administrative and living areas lead to inconvenience of residents, increased administration costs and scale diseconomy. Lastly, the living areas should be delimited by the metropolitan or mega city planning and thus be reflected to its offsprings.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.20 no.4
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• pp.106-114
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• 2012

As Incheon International Airport(IIA) is located in an island 50-km away from Seoul, various travel equipments for access are required. So far two connecting bridges are constructed funded by civilian funds. For the further bridge construction, the reduction of forecast traffic amount and the government subsidy for the civilian funds are big issues. Comparing the access traffics of IIA to those other competing airports, traffic conditions inside the airport are superior to other competing airports from the management point of view, as utilization conditions and equipment capacities are periodically monitored and evaluated to set up comprehensive countermeasures following constructing by stages. However, while the accessability to IIA is very important, as IIA is built on an island the conflicts between near-by developers and traffic facility operators make further bridge construction difficult. As improving the accessibility to an airport is not easy to achieve only by the IIA management's efforts, the central government level authorities should organize a committee with agencies concerned and analyze the characteristics of access traffic periodically to suggest reform measures for each organization concerned to implement appropriate undertakings at apt timing. For the future, central government's level empirical research on the airport accessibility for synthetic and systematic plan set-up is expected.

• Journal of Information Technology Applications and Management
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• v.21 no.1
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• pp.177-184
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• 2014

This research analyzes the effects of factors on the demands for outbound to the countries such as Japan, China, the United States of America, Thailand, Philippines, Hong Kong, Singapore and Australia, the countries preferred by many Koreans. The factors for this research are (1) economic variables such as Korea Composite Stock Price Index (KOSPI), which could have influences on outbound tourism and exchange rate and (2) unpredictable events such as diseases, financial crisis and terrors. Regression analysis was used to identify relationship based on the monthly data from January 2001 to December 2010. The results of the analysis show that both exchange rate and KOSPI have impacts on the demands for outbound travel. In the case of travels to the United States of America and Philippines, Korean tourists usually have particular purposes such as studying, visiting relatives, playing golf or honeymoon, thus they are less influenced by the exchange rate. Moreover, Korean tourists tend not to visit particular locations for some time when shock reaction happens. As the demands for outbound travels are different from country to country accompanied by economic variables and shock variables, differentiated measure to should be considered to come close to the target numbers of tourists by switching as well as creating the demands. For further study we plan to build outbound tourism forecasting models using Artificial Neural Networks.

• Structural Engineering and Mechanics
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• v.9 no.1
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• pp.17-35
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• 2000

Dynamic response of a three span continuous bridge has been determined by full scale experiments on the bridge. In the experiments, a heavy vehicle was driven across the bridge at different speeds and along different lanes of travel and the strains were recorded at different locations. The bridge was made of reinforced concrete and was asymmetric in plan and in elevation. Frequencies and modes of vibration excited by the vehicle were determined. The dependence of the dynamic amplification on bridge location and vehicle speed was investigated and dynamic amplifications up to 1.5 were recorded, which was higher than values predicted by bridge design codes. It was evident that when this asymmetric bridge was loaded by an asymmetric forcing function, higher modes, which are lateral and/or torsional in nature, were excited. Dynamic modulus of elasticity and the support stiffness influenced the natural frequencies of the bridge, which in turn influenced the dynamic amplifications. Larger than anticipated dynamic amplification factors and the excitation of lateral and/or torsional modes should be of interest and concern to bridge engineers.

• Journal of Information Technology Applications and Management
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• v.24 no.4
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• pp.187-196
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• 2017

It is urgent to prepare countermeasures for traffic congestion problems of Korea's metropolitan area where central functions such as economic, social, cultural, and education are excessively concentrated. Most users of public transportation in metropolitan areas including Seoul use the traffic cards. If various information is extracted from traffic big data produced by the traffic cards, they can provide basic data for transport policies, land usages, or facility plans. Therefore, in this study, we extract valuable information such as the subway passengers' frequent travel patterns from the big traffic data provided by the Seoul Metropolitan Government Big Data Campus. For this, we use a Hadoop (High-Availability Distributed Object-Oriented Platform) to preprocess the big data and store it into a Mongo database in order to analyze it by a sequential pattern data mining technique. Since we analysis the actual big data, that is, the traffic cards' data provided by the Seoul Metropolitan Government Big Data Campus, the analyzed results can be used as an important referenced data when the Seoul government makes a plan about the metropolitan traffic policies.

• Journal of the Korea Institute of Military Science and Technology
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• v.14 no.3
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• pp.327-334
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• 2011

It is necessary that UGV(Unmanned Ground Vehicle) should generate a real-time travesability index map by analyzing raw terrain information to travel autonomously tough terrain which has various slope and roughness values. In this paper, we propose a local path planning method, $MA^*$(Modified $A^*$) algorithm, using DVGM (Directional Velocity Grid Map) for unmanned ground vehicle. We also present a path optimization algorithm and a path smoothing algorithm which regenerate a pre-planned local path by $MA^*$ algorithm into the reasonable local path considering the mobility of UGV. Field test is conducted with UGV in order to verify the performance of local path planning method using DVGM. The local path planned by $MA^*$ is compared with the result of $A^*$ to verify the safety and optimality of proposed algorithm.

• Human Ecology Research
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• v.53 no.4
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• pp.375-390
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• 2015

This study was designed to understand the residential experience of Korean women living in tropical country. For qualitative research, interviewees were selected by snowball sampling among Korean women living in Malaysia for over 20 years. The selection criteria for interviewees included husband's nationality, occupational experience, future living plan, frequency of travel to Korea. In-depth group and individual interviews were conducted from August 23 to October 7 2014. Subsequently (1) interviewees' general residential experiences in Malaysia were summarized, (2) interviewee's identity and lifestyle with housing pathways approach were clarified, (3) interviewees' residential experiences in 5 issues, reciprocity in residential area, intention of environmental change, meaning of housing and interaction, housing adaptation, and residential satisfaction/dissatisfaction were prescribed and interpreted. In conclusion, the reflection of interviewees' experiences in tropical country, suggested variations of housing structure type within a residential complex, air well and pocket by setback in building block for improving ventilation and noise prevention from neighbors, and ceiling fans in the house were suggested for the upcoming subtropical climate in Korea. Full option and minus options were also suggested for the presale market to reduce before occupancy remodeling needs. The research results implies valuable suggestions for a multicultural society, ecological housing and stronger communities.