• KSCE Journal of Civil and Environmental Engineering Research
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• v.30 no.5D
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• pp.477-483
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• 2010

The existing mass transport system, with its limited capacity and the saturated road networks, has given cause for a new means of transport to be developed, and strong demands for such new means of transport are observed more than ever. However, the traffic authority is seeking a new transport system that focuses more on LRT(Light Rail Transit), a downsized version of the existing urban railroad, rather than one that is appropriate to solve the traffic problems. Moreover, local governments are experiencing difficulties in planning their own mass transportation(bus or urban railroad) as they have no specified criteria for selecting a mass transport system. Accordingly, there has been an increasingly loud voice that calls for criteria to determine which mass transport system befits each transportation corridor. This paper develops a mass-transport demand forecasting model based on the GIS Buffering analysis of each transportation corridor in the city, sets up the capacity for each mass transport system and presents the criteria for selecting an optimal mass transport system for each transportation corridor. It also presents a methodology that identifies necessary and sufficient conditions for selection and evaluation, since it is most important to select the optimal mass-transport system that can meet the demand by each mass-transportation corridor.

• Journal of the Korea Society for Simulation
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• v.33 no.2
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• pp.37-44
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• 2024

The Korean Helicopter Development Program has successfully introduced the Surion helicopter, a versatile multi-domain operational aircraft that replaces the aging UH-1 and 500MD helicopters. Specifically designed for maneuverability, the Surion plays a crucial role in low-altitude tactical maneuvers for personnel transportation and specific missions, emphasizing the helicopter's survivability. Despite the significance of its low-altitude tactical maneuver capability, there is a notable gap in research focusing on multi-mission tactical maneuvers that consider the risk factors associated with deploying the Surion in the presence of enemy air defenses. This study addresses this gap by exploring a method to enhance the Surion's low-altitude maneuvering paths, incorporating information about enemy air defenses. Leveraging the Proximal Policy Optimization (PPO) algorithm, a reinforcement learning-based approach, the research aims to optimize the helicopter's path planning. Visualized experiments were conducted using a Surion model implemented in the Unity environment and ML-Agents library. The proposed method resulted in a rapid and stable policy convergence for generating optimal maneuvering paths for the Surion. The experiments, based on two key criteria, "operation time" and "minimum damage," revealed distinct optimal paths. This divergence suggests the potential for effective tactical maneuvers in low-altitude situations, considering the risk factors associated with enemy air defenses. Importantly, the Surion's capability for remote control in all directions enhances its adaptability in complex operational environments.

• Journal of Korean Society of Transportation
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• v.24 no.2 s.88
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• pp.91-100
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• 2006

This paper examines the situation and tasks of UK rail privatization, especially focusing on after the Hatfield rail accident. Earlier research which focused on the UK's Privatization had little knowledge of the explanations for recent changes. Moreover they had difficulty making a direct comparison between national rail and the privatized rail. Therefore we aye left without a good explanation which has a comprehensive perspective. I attempt to show the change in the rail privatization Process and its outcome, focusing on after the Hatfield rail accident. This Paper argues that the UK's vail privatization process has a regulatory framework which is too complicated with overlapping responsibilities that brought about inefficiency, increasing costs and a superficial safety regime. Especially the planning of rail and infrastructure maintenance did not come to play an appropriate role. However after 2000, the government took charge of setting the strategy for railways, and the Office of Rail Regulation covered safety performance and cost. explain that these changes present a good opportunity to solve the problem of passing the buck for poor performance. Through the analysis, I find that the passenger rail network is well-suited to deliver long distance business and commuters and that the subsidy from the government is decreasing. However, performance, for example punctuality and reliability. should be improved. Especially the Hatfield rail accident caused a reduction in the satisfaction of passengers. In future. the problems of rising costs and monopoly franchise system should be addressed.

• Korean Journal of Agricultural and Forest Meteorology
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• v.12 no.4
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• pp.307-316
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• 2010

Complex terrain refers to irregular surface properties of the earth that influence gradients in climate, lateral transfer of materials, landscape distribution in soils properties, habitat selection of organisms, and via human preferences, the patterning in development of land use. Complex terrain of mountainous areas represents ca. 20% of the Earth's terrestrial surface; and such regions provide fresh water to at least half of humankind. Most major river systems originate in such terrain, and their resources are often associated with socio-economic competition and political disputes. The goals of the TERRECO-IRTG focus on building a bridge between ecosystem understanding in complex terrain and spatial assessments of ecosystem performance with respect to derived ecosystem services. More specifically, a coordinated assessment framework will be developed from landscape to regional scale applications to quantify trade-offs and will be applied to determine how shifts in climate and land use in complex terrain influence naturally derived ecosystem services. Within the scope of TERRECO, the abiotic and biotic studies of water yield and quality, production and biodiversity, soil processing of materials and trace gas emissions in complex terrain are merged. There is a need to quantitatively understand 1) the ecosystem services derived in regions of complex terrain, 2) the process regulation occurred to maintain those services, and 3) the sensitivities defining thresholds critical in stability of these systems. The TERRECO-IRTG is dedicated to joint study of ecosystems in complex terrain from landscape to regional scales. Our objectives are to reveal the spatial patterns in driving variables of essential ecosystem processes involved in ecosystem services of complex terrain region and hence, to evaluate the resulting ecosystem services, and further to provide new tools for understanding and managing such areas.

• The Korean Journal of Air & Space Law and Policy
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• v.33 no.2
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• pp.3-34
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• 2018

Korea's air transport industry has a 70-year history since Korea National Airline was establishment in October 1948. Korea has 9 airlines which have international air transport business licenses, and as of 2017, air transport performance(Domestic & International) is ranked 8th in the world. Through analysis of Korea's air transport industry, this paper examines the essential problems of the domestic air transport industry and what policies and laws should be supplemented, and presents an "Policy Directions for the Air Transport Industry" that can continue to grow into a global aviation leading country in the future. Analysis of aviation statistics shows that the nation's air transport industry has a very high growth rate, and national airlines continue to invest in sustainable growth. Furthermore, new companies are also trying to enter the market. As of November 2018, four companies applied for licenses for international air transport business, one for international air transport business (cargo) license, and the Ministry of Land, Infrastructure and Transport is expected to decide whether to issue the license by first quarter of 2019. While some expect price reductions and consumer benefits through competition promotion, others worry about worsening airline financial structures and reducing safety investment due to competition. To sum up the problems of the nation's air transport industry, first, low-cost airlines focus only on attracting domestic demand, and thus have a weak foundation for continued growth. Second, the rapid growth in recent years has led to the lack of aviation professionals such as pilots and technicians and the saturation of slots at major airports. Third, since the financial soundness of airlines is not systematically managed, the financial situation of airlines can quickly deteriorate and the damage can be attributed to consumers. In order for the national airlines to continue to develop, the first is to focus on the endless demand of the global aviation market and to secure international competitiveness. Second, the government should support the airline infrastructure according to the size of the air transport industry, third, we will systematically nurture aviation experts who will lead the future of the nation's air transport industry, and finally, the government will have to continuously manage the financial status of airlines to prevent consumer damage in advance. Nowadays the air transport industry has become very competitive. Not only do airlines have to work hard for the sustainable development of national airlines, but all government agencies must support our airline companies in policy to win international competition.

• The Journal of Engineering Geology
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• v.28 no.2
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• pp.217-246
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• 2018

During the selection and characterization of target formations in the Small-scale Offshore $CO_2$ Storage Demonstration Project in the Pohang Basin, we have carefully investigated the possibility of induced earthquakes and leakage of $CO_2$ during the injection, and have designed the storage processes to minimize these effects. However, people in Pohang city have a great concern on $CO_2$-injection-intrigued seismicity, since they have greatly suffered from the 5.4 magnitude earthquake on Nov. 15, 2017. The research team of the project performed an extensive self-investigation on the safety issues, especially on the possible $CO_2$ leakage from the target formation and induced earthquakes. The target formation is 10 km apart from the epicenter of the Pohang earthquake and the depth is also quite shallow, only 750 to 800 m from the sea bottom. The project performed a pilot injection in the target formation from Jan. 12 to Mar. 12, 2017, which implies that there are no direct correlation of the Pohang earthquake on Nov. 15, 2017. In addition, the $CO_2$ injection of the storage project does not fracture rock formations, instead, the supercritical $CO_2$ fluid replaces formation water in the pore space gradually. The self-investigation results show that there is almost no chance for the injection to induce significant earthquakes unless injection lasts for a very long time to build a very high pore pressure, which can be easily monitored. The amount of injected $CO_2$ in the project was around 100 metric-tonne that is irrelevant to the Pohang earthquake. The investigation result on long-term safety also shows that the induced earthquakes or the reactivation of existing faults can be prevented successfully when the injection pressure is controlled not to demage cap-rock formation nor exceed Coulomb stresses of existing faults. The project has been performing extensive studies on critical stress for fracturing neighboring formations, reactivation stress of existing faults, well-completion processes to minimize possible leakage, transport/leakage monitoring of injected $CO_2$, and operation procedures for ensuring the storage safety. These extensive studies showed that there will be little chance in $CO_2$ leakage that affects human life. In conclusion, the Small-scale Offshore $CO_2$ Storage Demonstration Project in the Pohang Basin would not cause any induced earthquakes nor signifiant $CO_2$ leakage that people can sense. The research team will give every effort to secure the safety of the storage site.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.31 no.6D
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• pp.771-778
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• 2011

Preliminary feasibility study on Busan metro line #1 in Yangsan line (Nopo-Bukjeong) depending on active volume of mass transportation between Yangsan city and Busan city was conducted. As the study concluded that it's valid, the necessity to establish the metro railroad network connecting to Busan, Ulsan and Gyeongnam Province is demanded to improve the transportation issues in Ungsang area vulnerable to metro service and to drive the balanced development between metropolitan cities. In addition, the volume of transportation depending on methods in target areas and road traffic assignment are surveyed to put a stress on the necessity to establish the metro railroad network. As the demand of transportation for alternative lines is predicted, the budget and benefits for construction for each alternative line set for the rough economic analysis depending on traffic volume for each method and traffic assignment results. The total project budget necessary for construction of proposal line #1 set as effective one among target three lines in this project is calculated in 794.32 billion won. Construction accounts for the most expensive in expenses for project and contingency allowances, purchases for vehicles and collateral expense are followed in orders. However, compensation for lands is not counted. In particular, according to economic analysis in proposal #1, ratio of benefit/cost (B/C) is 0.584, net present value (NPV) is -217.47 billion won, the internal rate of return (IRR) is analyzed in 0.604 %. At the current stage, it is not economically feasible, but the B/C is 0.737 in long-term upon construction of Yangsan line between Wolpheong and Yongdang which is proposal line #3. Therefore, when Busan metro basic plan is reorganized to aim the benefit of residents in Ungsang area vulnerable to the metro service, we think it must be necessary to establish the metro railroad network connecting to Busan-Yangsan-Ulsan which is proposal line #2 by extending the existing Sinjeong line and including this task line in high-ranked plan related to metro railroad.

• The Korean Journal of Air & Space Law and Policy
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• v.31 no.2
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• pp.3-35
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• 2016

The United States Constitution gives power to the federal district courts to hear admiralty cases. 28 U.S.C. §.133, which states that "The district courts shall have original jurisdiction, exclusive of the Courts of the States, of any civil case of admiralty or maritime jurisdiction." However, the determination of whether a case is about admiralty or maritime so that triggers admiralty jurisdiction was not a simple question. Through numerous legal precedents, the courts have drawn a line to clarify the boundary of admiralty cases. This unique jurisdiction is not determined by the mere involvement of a vessel in the case or even by the occurrence of an event on a waterway. As a general rule, a case is within admiralty jurisdiction if it arises from an accident on the navigable waters of the United States (locus test) and involves some aspect of maritime commerce (nexus test). With regarding to the maritime nexus requirement, the US Supreme Court case, Executive Jet Aviation, Inc. v. City of Cleveland, held that federal courts lacked admiralty jurisdiction over an aviation tort claim where a plane during a flight wholly within the US crashed in Lake Erie. Although maritime locus was present, the Court excluded admiralty jurisdiction because the incident was "only fortuitously and incidentally connected to navigable waters" and bore "no relationship to traditional maritime activity." However, this historical case left a milestone question: whether an aircraft disaster occurred on navigable water triggers the admiralty jurisdiction, only for the reason that it was for international transportation? This article is to explore the meaning of admiralty jurisdiction over aviation accidents at US courts. Given that the aircraft engaged in transportation of passenger and goods as the vessels did in the past, the aviation has been linked closely with the traditional maritime activities. From this view, this article reviews a decision delivered by the Seventh Circuit regarding the aviation accident occurred on July 6, 2013 at San Francisco International Airport.

• The Korean Journal of Air & Space Law and Policy
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• v.35 no.3
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• pp.95-126
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• 2020

In 2017, the world's first WIG ship (WIG: Wing In-Ground) pilot's license written test was conducted in Korea. The WIG ship is a ship that combines the characteristics of ships and airplanes. Therefore, the pilot of the WIG ship was allowed to apply only for those who had the aircraft pilot's license and the 6th class marine nautical license. The WIG ship pilot's license system was first introduced by Korea, so there are no international standards for the license system, and the introduction of a domestic qualification system also requires institutional arrangements due to various restrictions such as pilot training. However, in order to become a valuable industry as a future growth engine for the ocean, several urgent problems need to be solved, and that is the training of manpower for WIG ships. Therefore, I reviewed the institutional issues related to pilot training as this subject. Since 2001, various countries around the world have been discussing this issue, centering on IMO, and Korea has continued to participate and cooperate in IMO meetings. And the national qualification test for surface flying ships was conducted in Korea from 2011. However, there are still problems to be solved, and I pointed out the advancement of the manpower training system, the education and training system, and the designated national educational institution system. As a solution to this, it was suggested through the improvement of the license system and the operation of designated educational institutions. Among these solutions, I believe that the best way is to entrust the operation of designated national educational institutions to private educational institutions. However, I propose a plan that the government entrusts to private educational institutions, but the government is responsible for licensing and supervision. WIG ship will be a new market for the aviation industry and aviation workers.

• Journal of Korean Home Economics Education Association
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• v.17 no.4 s.38
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• pp.133-156
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• 2005

This study clarifies the concept of the education content relevance in order to evaluate the content relevance of Technology & Home Economics in a secondary school, and design its standards based on the preceding study. In other words, four standards such as the amount of studying content, the degree of difficulty, the validity of contents and the sequence of contents are established. Also, a survey on the current status of nationwide units targeting students, teachers, and professors was conducted to collect actual data about relevance evaluation. The results are as follows. First, as for the evaluation in terms of the amount of studying content, the majority of respondents answered that it decreased by about $30\%$ when compared to the 6th Technology & Home Economics Curriculum However, middle school teachers pointed out that the number of classes is not enough considering the fact that it's an activity-oriented subject. So, they acknowledged that the amount of study time during a Technology Sl Home Economics class is 'quite a lot.' Second, the evaluation in the degree of difficulty is divided into two responses. Teachers responded that it's reasonable overall, but according to students, it's difficult. Especially, the chapters that students don't understand well including 'The Elements of Draftsmanship,"' 'Understanding of Machinery,' 'Electronics & Electricity Technology,' and 'Energy & Transportation Technology.' In the Home Economics area, 'The Design of Home Life' is the only chapter that students don't understand well. Third, as for the validity of contents, the chapters that were not considered as important considering the objective of Technology Sl Home Economics Curriculum include 'The Elements of Draftsmanship,' 'Computer & Processing,' and 'The Management of Resources and Environment.' Fourth, as for the sequence of contents, the survey was conducted including the name of the course asone of the survey items. The majority of teachers wanted it as it is, but the Professors of education colleges who wanted the 3rd name to connect the course with the elementary school course was a little more $(50.5\%)$ than the ones who don't want any changes $(45.5\%)$. The follow-up study should correct and complement the standards that this study suggested through analytic and critical review according to the character & goal of the subject. Based on such standards, the evaluation of content relevance should be continued to realize the quality control of the curriculum systematically.