• Journal of Korea Port Economic Association
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• v.32 no.4
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• pp.41-56
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• 2016

China is pushing a policy called China's Western Development in order to balance the continent's development level. They are connecting the rich natural resources of the mid-western areas and the capital of the eastern coastal areas of China. Since Korea depends on China the most for trade, it is necessary for Korea to always consider the trade scale and pattern changes of China. Response to changes in the transport and logistics system between the two countries is also demanded. This study aims to analyze the import and export trends between Korean and Chinese provinces of each item from the trade scale point of view. China's global trade routes reorganization and China's western development are considered and the corresponding direction is presented accordingly. The study also suggests strategies to expand the import and export scale with China based on the analysis.

• Journal of Digital Convergence
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• v.19 no.9
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• pp.9-18
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• 2021

Constructing the Metropolitan Railway Express (the GTX) may have an impact on consumer confidence and housing sales price located near the planned route. This study looked at how consumers' psychology and housing prices change as the large-scale transport infrastructure plane was planned. Also, it looked at the relationship between consumer sentiment and housing prices to analyze the impact of new transportation facilities inflows. Using a correlation analysis, the relationship between the consumer sentiment index and the actual transaction price of apartments was identified. The impact of GTX on the consumer sentiment index and the actual transaction price of apartments was looked at using the Difference-in-Differences methodology. Our finding shows that the construction plan of a large-scale transportation infrastructure in the metropolitan area affects the sentiment of housing consumption and actual transactions. In a situation where the government is speeding up the construction of a wide-area transportation network such as GTX with the goal of becoming a city where people can commute to downtown Seoul within 30 minutes, policies that can stabilize the housing market in transportation hubs should be suggested.

• Proceedings of the Korea Water Resources Association Conference
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• 2023.05a
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• pp.288-288
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• 2023

도로, 철도 등의 횡단통로, 오폐수관로, 지하배수관 등 연약지반에서 상재하중과 부등침하에 의한 파괴 위험을 줄이기 위해 구조적인 안전성과 내구성이 개선된 다양한 관로들이 활용되고 있다. 관은 매설특성에 따라 콘크리트관, 도관, 합성수지관, 덕타일 주철관, 파형강관, 유리섬유 강화 플라스틱과 폴리에스테르수지 콘크리트관 등의 종류로 구분된다(환경부, 2017). 수리설계 시 이러한 관의 단면 규모 결정 및 흐름 특성을 파악하기 위해 관수로 유량측정에 이용되는 Manning의 경험식을 이용하고 있으며, 관로의 주요 재질에 따른 다양한 조도계수가 제시되어 있다. 새로운 재질을 이용하여 제작된 관은 수리실험을 통해 조도계수를 결정하는 것이 바람직하지만, 조도계수 실험은 대규모의 실험시설과 유량공급이 요구되기 때문에 여러 한계가 있다. PE관의 경우, 미국의 ASTM 표준에 의해 저밀도 폴리에틸렌(LDPE), 선형 저밀도 폴리에틸렌(LLDPE), 고밀도 폴리에틸렌(HDPE) 등으로 분류되는데 본 연구에서는 HDPE 재질의 서로 직경이 다른 다중벽관 PE관을 대상으로 조도계수를 결정하기 위한 현장 실규모 수리실험을 수행하였다. 본 실험에서는 식생, 수로의 불규칙성, 수로노선, 침전과 세굴, 장애물, 계절적 변화, 부유물질과 소류사는 무시되며 표면조도, 관의 크기와 형상, 수위와 유량이 조도계수에 영향을 미치는 주요 인자라고 할 수 있다. 수리실험은 실물모형(Prototype)으로 한국농어촌공사 농어촌연구원의 대형수리모형실험장에서 수행되었으며. 길이 24 m, 직경 150 mm의 PE 관은 고정식 개수로, 직경 800 mm의 관은 대형유사순환수로에 각각 설치되었다. 관로의 전면에 차폐막을 설치하여 상류부 수위를 안정시킨 상태에서 실험을 수행하였고, 차폐막으로부터 하류방향으로 약 7 m(측정기준지점), 11 m, 13 m, 15 m, 17 m 떨어진 곳에서 각각 수위와 유속을 측정하였다. 실험 결과, φ150관은 직경대비 수심이 클수록 조도계수가 감소하는 경향이 나타났고, φ800관은 직경대비 수심의 변화에 따른 조도계수의 경향이 크게 드러나지 않았다. 결론적으로 PE관의 조도계수는 수심별로 변화하는 것으로 나타났으며, 특정 수심을 지나면 조도계수가 다시 감소할 것으로 판단된다.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.6
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• pp.614-627
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• 2018

Urban railway lines have been constructed adjacent to residential buildings and urban areas. The expansion of transportation networks and reconstruction of residential buildings in highly populated urban areas require deep excavations in areas adjacent to urban railways. Mobilized soil stresses and changes in the groundwater level induced by deep excavations results in track irregularities in urban railways. In this study, a three-dimensional finite difference model using the commercial program FLAC3D was adopted to estimate the horizontal displacements of earth retaining structures, settlements of backfill, the stability of track irregularity and underground box structure based on the criteria of each railway organization and its relationships. In deep excavations, a change in groundwater level induces relatively very small differences for track gauge irregularities, whereas relatively large differences for longitudinal irregularities of 72.5%, twist irregularities of 83.3%, cross level irregularities of 61.9%, and alignments of 43.3% were found to be the maximum differences when the horizontal displacement of earth retaining wall and settlement of backfill were 65.1% and 21.4%, respectively, because the groundwater level (GWL) on the ground surface-mobilized tensile strength of the underground box structure exceeds the allowable value. Therefore, three-dimensional numerical analysis was performed in this study. Overall, real-time monitoring should be carried out to prevent railway accidents in advance when a deep excavation adjacent to urban railway structures is constructed.

• The Journal of the Korea Contents Association
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• v.18 no.12
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• pp.456-467
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• 2018

This study analyzed the repeated causes of policy failure focusing on Yangyang International Airport cases. Yangyang International Airport, which opened in 2002, was built with about 360 billion won, but it is considered as a representative example of policy failure of local airports. According to the policy failure theory, the failure factors of Yangyang International Airport are anlyzed by rationalistic, political, and environmental complexity viewpoint. The results are as follows. First, from a rationalist point of view, Yangyang Airport failed to achieve the policy goal of securing passengers and revitalizing local economy, This is due to the pressure of politics and the lack of geographical infrastructure. Second, the failure of the stakeholders to resolve conflicts in the flow of politics can be seen as the conflict between the airline and the airport, and the failure to reconcile conflicts between the government and the airports on the low cost airline permits and subsidies. Third, from the viewpoint of environmental complexity, Yangyang International Airport can be regarded as a failure to adapt to environmental changes such as the opening of nearby expressways and railway lines, and the sharp decline of Chinese tourists. This study sugeests the establishment of an independent organization that can prevent unreasonable business promotion by politics in the case of large scale national projects, the linkage with the surrounding infrastructure and related businesses in the case of transportation facilities such as airports and railways, and institutionalization of cooperative governance for coordinating conflict among stakeholders.

• The Journal of Engineering Geology
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• v.20 no.3
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• pp.329-338
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• 2010

The foundation area for tram contains biotite gneiss, quartzo-feldspathic gneiss, calc-silicate rock, and porphyroblastic gneiss of the pre-Cambrian Kyeonggi gneiss complex. These rocks record at least three stages of deformation, as indicated by fold sets of contrasting orientations (D1-D3). Joints are generally steeply dipping and strike NW-SE to WNW-ESE. The Gonjiam Fault, which strikes WNW-ESE, follows a river in the area. The fault possesses a 3-m-wide fracture zone, a 10-m-wide damage zone, and is 15 km long. Two tunnels have been constructed through the biotite gneiss. The geometric relationship between discontinuities (e.g., joints and foliation) and tunneling direction reveals that set 3 of the AA tunnel is unstable but that BB tunnel is relatively safe.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.9 no.5
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• pp.1-13
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• 2010

In this paper, we describe the result of the test-bed on Nation-wide Interoperable Transportation System connected with Interoperable Traffic Information Collection System, which was developed by Korea Financial Telecommunications & Clearings, KOREAIL NETWORKS, HiPlusCard and Samsung SDS. we constructed Nation-wide Interoperable Transportation System on 4 downtown bus routes, 20 stations on line 1 subway, 2 stations of a train and 2 sections of the Honam highway in Gwangju and Interoperable Traffic Information Collection System in Seoul University IC Card Center. So we operated that by 480 Several staff were given a test card and asked to try it for about 6 months. This test-bed is for demonstrates the accuracy, safety and credibility of the Nation-wide Interoperability standard technology and it can be applied to all of transportation practically. When the staffs contact the card to Purchase terminal, the card performs transaction with Purchase SAM in the terminal, then transactions ara used to calculate in Settlement system and Interoperable Traffic Information Collection System. Through the test-bed, we examined this process and found unexpected problems happening during the test operation and have successfully solved them. In addition, the results of the test-bed let us know what additional improvement might be required for System. The successful run of the test-bed was verified by an evaluation of the test-bed staff and a public survey.

• Journal of the Korean association of regional geographers
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• v.8 no.3
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• pp.295-313
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• 2002

While the growth of Taegu has occurred through the land readjustment project, the public sector development project and the construction of roads, its growth pattern has been shaped by physical constraints such as mountains, streams and rail roads. The processes of urban growth of Taegu are classified into four stages: the stage of urban embryo in the Chosun Era; the formation stage of the basic urban system after the Japanese Colonial Era up to 1960; the stage of urban growth in the industrialization period from 1960s to 1980; and lastly, the stage of urban expansion and maturation, with construction of extensive newly developed districts, after the 1980s. Since its promotion to a metropolitan city with the inclusion of Seongseo, Wolbae, Gosan, Ansim and Chilgok in 1981, those regions have grown into newly developed residential districts, with its accompanying high density and high rise apartments complexes, through the public sector development project. These newly developed districts are located about six to seven kilometers away from CBD of the city along with main radial roads. The sites are also located on the route of the fourth belt way of the city. While the Sangin, Seongseo and Jisan Beommul newly developed districts have developed contiguously with the existing built-up areas, the Siji and Chilgok districts have developed separately by the green belt and the Geumho River, respectively.

• Journal of the Korea institute for structural maintenance and inspection
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• v.27 no.6
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• pp.120-129
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• 2023

To evaluate the vertical loads on railway bridges, conventional load tests are typically conducted. However, these tests often entail significant costs and procedural challenges. Railway conditions involve nearly identical load profiles due to standardized rail systems, which may appear straightforward in terms of load conditions. Nevertheless, this study aims to validate load tests conducted under operational train conditions by comparing the results with those obtained from conventional load tests. Additionally, static and dynamic structural behaviors are extracted from the measurement data for evaluation. To ensure the reliability of load testing, this research demonstrates feasibility through comparisons of existing measurement data with sensor attachment locations, train speeds, responses between different rail lines, tendency analysis, selection of impact coefficients, and analysis of natural frequencies. This study applies to the Dongho Railway Bridge and verifies the applicability of the proposed method. Ten operational trains and 44 sensors were deployed on the bridge to measure deformations and deflections during load test intervals, which were then compared with theoretical values. The analysis results indicate good symmetry and overlap of loads, as well as a favorable comparison between static and dynamic load test results. The maximum measured impact coefficient (0.092) was found to be lower than the theoretical impact coefficient (0.327), and the impact influence from live loads was deemed acceptable. The measured natural frequencies approximated the theoretical values, with an average of 2.393Hz compared to the calculated value of 2.415Hz. Based on these results, this paper demonstrates that for evaluating vertical loads, it is possible to measure deformations and deflections of truss railway bridges through load tests under operational train conditions without traffic control, enabling the calculation of response factors for stress adjustments.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.5
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• pp.131-138
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• 2018

In this study, we investigated the trend of technological development in major countries related to the propulsion equipment of railway vehicles. The propulsion system is the main equipment of electric vehicles. A lot of time and investment are required in order to ensure the development of technology. Therefore, developed countries have maximized their effort to develop technologies with safety, reliability, and convenience of maintenance. They have also done their utmost to prevent technology transfer to other countries after the development of new technologies. For example, Toshiba of Japan developed a new 3,300V/1,500 A class IGBT power device, but was reluctant to export it to foreign countries in order to protect this technology. In this study, we analyzed the patents applied for related to propulsion control systems and presented the direction of development during the technical development of these systems. The patent analysis of the core technologies was conducted using the Thomson Innovation DB. We examined the number of patents applied for by country, year and major applicant. As a result of the analysis, it was found that the proportion of patent applications per country was in the order of China, 48%, Europe 16.6%, and the United States 14.9%. The patent situation of the top 10 principal applicants revealed that (the top three were?) ABB 14%, GE 13%, and CRRC 12%. At the same time, we also conducted a qualitative analysis of the level of technical development by evaluating such factors as the influence index, quotation, market securing power and citation. Based on the result of the patent analysis, we presented the direction of technical development of the propulsion control equipment of railway vehicles. Based on the analysis results, it was found that domestic applicants considerably reduced their efforts to protect their patents from foreign companies. Nowadays, most of the electric motors used in Korea are induction motors. In advanced countries, permanent magnet electric motors are employed in new railway lines. Therefore, intensive investment is needed in new developments.