• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.43 no.6
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• pp.488-496
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• 2015

This paper proposes a framework to determine the routes of multiple unmanned aerial vehicles (UAVs) to conduct multiple tasks in different locations considering the survivability of the vehicles. The routing problem can be formulated as the vehicle routing problem (VRP) with different cost matrices representing the trade-off between the safety of the UAVs and the mission completion time. The threat level for a UAV at a certain location was modeled considering the detection probability and the shoot-down probability. The minimal-cost path connecting two locations considering the threat level and the flight distance was obtained using the Dijkstra algorithm in hexagonal cells. A case study for determining the optimal routes for a persistent multi-UAVs surveillance and reconnaissance missions given multiple enemy bases was conducted and its results were discussed.

• Journal of Space Technology and Applications
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• v.2 no.1
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• pp.1-12
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• 2022

In this paper, we described the development of a drag augmentation device for nanosatellite. Recently, space industry has entered the New Space era, and barriers to entry into Low Earth Orbit (LEO) for artificial objects such as small rockets and nanosatellite mega constellations have been significantly lowered. As a result, the number of space debris is increasing exponentially, and it is approaching as a major threat to satellite currently in operation as well as satellites to be launched in near future. To prevent this, international organizations like Inter-Agency Space Debris Coordination Committee (IADC) have been proposed space debris mitigation guidelines. The Korea Aerospace Research Institute (KARI) conducted KARI Rendezvous & Docking demonstration SATellite (KARDSAT) project, the first nanosatellites for rendezvous and docking technology demonstration in Korea, and we also developed drag augmentation device for KARDSAT Target nanosatellite that complied with the international guideline of post-mission disposal.

• International Journal of Aeronautical and Space Sciences
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• v.13 no.1
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• pp.99-105
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• 2012

Track-before-detect techniques based on dynamic programming have provided solutions for detecting targets from a sequence of images. In its application to airborne threat detection, dynamic programming solutions should take into account the distinguishable properties of objects in a collision course. This paper describes the development of a new track scoring function that accumulates scores for airborne targets in Bayesian framework. Numerical results show that the proposed scoring function has slightly better detection capabilities.

• Journal of Environmental Science International
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• v.28 no.12
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• pp.1133-1145
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• 2019

Successful launch requires state-of-the-art launch vehicle technology and constant test operations, However, the meteorological threat to the launch vehicle flight trajectory is also an important factor for launch success. Atmospheric stability above the Naro Space Center at the this time is very important, especially because the initial flight operation can determine the success of the launch. Moreover, during the flight of launch vehicle with rapid pressure and thrust into the atmosphere, convection activity in the atmosphere may create environmental conditions that cause severe weather threats such as thunderstorms. Hence, studies of atmospheric instability characteristics over the Naro Space Center are a necessary part of successful launch missions. Therefore, the main aims of this study were to (1) verify the atmospheric stability index and convection activity characteristics over the Naro Space Center using radiosonde data observed from 2007 to 2018 by the Naro Space Center, (2) analyze changes in the atmospheric stability index according to monthly and seasonal changes, and (3) assess how the calculated atmospheric stability index is related to actual thunderstorm occurrence using statistical analysis. Additionally, we aimed to investigate the atmospheric characteristics above the Naro Space Center through the distribution chart of the atmospheric stability index during summer, when convection activity is highest. Finally, we assessed the relationship between lightning occurrence and unstable atmospheric conditions, through predictability analysis performed using the lightning observation data of the Korea Meteorological Administration.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.49 no.6
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• pp.521-528
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• 2021

In order to allocate an appropriate interceptor weapon to an air track for which the threat assessment has been completed, it is necessary to evaluate the suitability of engagement in consideration of the expected point of engagement. In this thesis, a method of calculating the kill probability is proposed according to the position in the engagement space using Bayesian theorem with multivariate attribute information such as relative distance, approach azimuth angle, and altitude of the air track when passing through the engagement space. As a result of the calculation, it was confirmed that the distribution form of the kill probability value for each point in the engagement space follows a multivariate normal distribution based on the optimal predicted intercepting point. It is expected to be applicable to the engagement suitability evaluation of the engagement space.

• Journal of Korean Society of Rural Planning
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• v.28 no.3
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• pp.111-125
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• 2022

Korea's rapid urbanization caused problems, such as destruction of the rural environment, loss of traditional culture and dissolution of communities, as the continuous outflow of the population from rural areas, aging and consequent labor shortages and deterioration of the living environment were connected like a vicious cycle. In order to solve the problems of rural areas and overcome their vulnerabilities, the ultimate goal is to find a way to reintroduce the population to the rural areas. In order to be reborn as a space with rural characteristics and pluralistic functions and various potentials in a space under threat of underdevelopment and extinction, the pushing factor from rural areas is improved, and the population inflow factor to the rural areas is improved to enhance rural attractiveness, focusing on creativity among the 4Cs of New Ruralism: Conservation, Cultivation, Community, Creativity. A case study of 'Creative space in rural areas' was studied and considered. In-depth interviews were conducted with four key stakeholders, and the research results were analyzed focusing on the grounded theory method to draw implications from the background of Gurye Natural Dream Park, characteristics that can be viewed as creative spaces, and examples of creative space creation in rural areas. The 'Creative space in rural areas' is a space that can solve the current issues and problems of rural areas. In the case of Gurye Natural Dream Park, the young population of Gurye is increasing through job creation, provision of living and cultural service facilities, and improvement of the education and medical environment. In this study, the existing rural problem-solving process in this process was viewed as creativity in rural areas.

• Korean Chemical Engineering Research
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• v.61 no.2
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• pp.208-216
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• 2023

In this study, using the Delphi method, 20 responses to 4 questions (need for launch safety control, top-priority considerations for ensuring public safety during launch, necessary improvements for securing maritime safety, and maritime safety threat factors) regarding launch vehicles and public safety were obtained from experts, and their importance was evaluated to analyze the factors that threaten the reinforcement of maritime safety around launch sites and flight paths when launching. According to the results of an analytic hierarchy process (AHP) analysis, the consistency ratio of the four questions was 4.8%, which is lower than CR ≤ 0.1(10%), and the consistency percentage of the lower measurement indicators was 3.9~5.7%. The derived importance and priority of maritime safety threat factors during launching were in the following order: Substantial human and physical damage in case of launch accidents(0.36), Prepare legal bases (e.g., penalty details) regarding maritime control(0.32), Secure the safety of personnel, equipment, and facilities in danger zone(0.31), Unauthorized entry of vessels in maritime control zones and non-compliance to restrictions(0.30). This article can serve as a reference for strengthening maritime safety in areas around launch sites and flight paths.

• Proceeding of Spring/Autumn Annual Conference of KHA
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• 2009.04a
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• pp.327-331
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• 2009

Covering structures and elevated road of Cheonggyecheon are the by-products of the developing era when functionality and efficiency were emphasized. Historic river restoration project around Cheonggyecheon which had been emerged as a threat to the safety of the citizens due to its corrosion and structural defects as time passes had been performed during the period from July, 2003 through October, 2005 under the slogan of future-oriented urban environment creation. By dint of this river restoration project, its value is being heightened as almost all the rivers of Seoul including Seongbukcheon, Chungreungcheon and Honghaecheon have been arranged by inter-active linkage. In addition, this river is becoming a place frequented by the numerous visitors at home and aborad by providing the citizens with an attractive space for utilizing leisure time. Currently in the diversified areas, an academic research on the Cheonggyecheon restoration is under progress. In this study, sampled questionnaire for the visitors was carried out by site visit with the necessity of users' satisfaction survey in terms of revitalization of pedestrian space of the city street. As a result of this, natural restoration and provision of leisure space were surveyed to be highly assessed in terms of satisfaction and insufficient provision of convenience facilities including toilet and parking space was pointed out as a matter to be improved. As Cheonggyecheon is invigorated from the obstacle of urban environment through its epochal restoration, its value provided to us will be evaluated and by supplementing the deduced problems, we intend to find its meaning in our hope that this would become a sustainable future assets providing a basic data.

• Journal of Digital Convergence
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• v.9 no.3
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• pp.11-19
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• 2011

The spread of computer and network gets various social and economic activities done quickly and efficiently. As a result, it makes a crime using network easy and increases the vulnerability of a social system. As there is a crime as a social being, we need to give careful consideration to the crime occurring in virtual space. Accordingly, the purpose of this paper is to investigate the regulatory need of the Criminal Procedure concerning the network security issues as the new legal and regulatory space that begins to be realized from the late of 20th century because of the extent of social threat. Above all, we addresses whether the amendment of existing legal regulations is necessary, based on the special characteristics of the virtual space.

• Korean Institute of Interior Design Journal
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• v.14 no.4 s.51
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• pp.106-113
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• 2005

The advancements of the society aggravate ecological problems, and it is at a point where our living environment is under a serious threat. To resolve such problems, environmental friendly design concepts are evolving through various naming conventions such as conservation of global environment, environmental symbiosis, friendly environmental, nature-friendly, environmental friendly type, green building and eco-construction. Accordingly, in this research, for the purposes of healthy living environmental construction, nature as the subject of its design and highly praised as a new design arena, floral art design theory and its functions, as well as its examples are explored. With the Information available, I was able to confirm that, in interior decorating, floral art design is used as a tool for expressing environmental friendly space, and gradually its necessity and the scope of its application have been broadened. Therefore, utilization of floral art design is to fabricate environmental friendly interior space; and it is expected as a substitute for accomplishing green amenity, and its study should continue for the years to come.