• Journal of the Korea Knowledge Information Technology Society
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• v.12 no.4
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• pp.539-550
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• 2017

In this paper, we designed, fabricated and tested an UHF band cylindrical dipole array antenna. In the proposed antenna, cylindrical dipoles were vertically arranged in four stages. A parallel structure feeding circuit was installed inside the cylindrical dipole and mounted so as to be broadband matching. The feeding circuit was installed at the center of the cylindrical dipole to optimize the gain flatness characteristic of the azimuth direction omnidirectional radiation pattern. Minimizing the difference between the signals branched from the feeding circuit and realizing the symmetry of the radiation pattern. The required specifications are more than 11.2% bandwidth in UHF band, above 6dBi antenna gain, standing wave ratio of 2:1 or less, less than ${\pm}1dB$ gain flatness in azimuth radiation pattern, more than 13 degrees in elevation radiation pattern of 3dB beamwidth. We confirmed the possibility of implementation through M&S and verified the result of M&S through production and testing. The test results are 11.2% bandwidth in the UHF band, 6.30 to 8.31 dBi gain, 1.53:1 standing wave ratio or less, within ${\pm}0.2dB$ gain flatness in the azimuth radiation pattern, elevation radiation pattern of 3dB beam width was 15.62 to 15.84 degrees. The test result meets all requirements specifications.

• Journal of the Korean Society of Marine Environment & Safety
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• v.28 no.2
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• pp.297-306
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• 2022

AtoN is an acronym for aids to navigation that indicate the position or direction of navigable areas and obstructions. AtoN should be arranged in consideration of unfamiliar navigator's convenience when it is indicated as the limits of navigable areas. Several narrow channels exist on the SW coast of Korea owing to the geographical effect, and the lateral or cardinal marks by the IALA maritime buoyage system are arranged along the narrow channels. This is an actual case study that analyzed the AtoN's role for safety navigation after changes in the maritime traffic environment owing to aquarfarm's development on narrow channels in the Korean SW coast. The analysis results of 5 narrow channels indicated that certain marks did not function properly as lateral or cardinal marks owing to the aquarfarm's location on navigable areas. Therefore, the following were suggested to improve AtoN on narrow channels: changing the position of marks, installing aquafarm's marks, and expressing the aquafarm's position on the nautical chart.

• The Journal of the Convergence on Culture Technology
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• v.10 no.4
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• pp.483-494
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• 2024

This study is a study on influencing factors to derive considerations when establishing a large drone integrated protection system targeting important national facilities. Currently, drone protection is implemented by piecemeal installation of drone protection equipment developed on the market in response to the needs of government agencies, the military, and national important facilities. For this reason, there is a waste of resources, such as duplicate installation or overlapping operation of equipment, and institutional and legal problems between operations are emerging. Accordingly, we sought to identify factors influencing the establishment of an efficient and systematic anti-drone protection system targeting national important facilities. Considering the research purpose and scope, this study derived 3 influencing factors and 12 detailed influencing factors through case analysis, protection theory research, and analysis of related laws. If the results of this study are used as considerations when building an integrated anti-drone protection system in the future, all national defense elements will be integrated and systematic integrated anti-drone protection will be possible according to their respective roles. In addition, it will provide a theoretical foundation for building an integrated anti-drone protection system. The results of this study are valuable in that they present logical and systematic influencing factors for establishing an integrated anti-drone protection system.

• Journal of Korean Society for Geospatial Information Science
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• v.24 no.3
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• pp.29-38
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• 2016

As publicizing of electromagnetic devices such as smart_phone and drone etc. which are relate with geomagnetic direction, and recognition about the importance to space weather effect and their hazards rises up recently, it is required heavily that the study on the effective measurement of geomagnetic declination and geomagnetic field effects of space weather. The purpose of this study is that the investigation of the feasibility of the absolute geomagnetic measurement in a place, where man-made geomagnetic contamination is low or negligible, with replacing the azimuth marks used for the absolute geomagnetic declination measurement with unified control points(UCP) which established at suburb. Further to this, have first derived the correlation of daily variations and disturbance level between the published indices($K_P$ and $K_K$) and geomagnetic element calculated from geomagnetic data of Cheongyang observatory located at the middle stage in Korea and is a member of INTERMAGNET. In addition, have carried out that the absolute measurement for the geomagnetic declination at three places near unified control point and one place with wide open field in Korea. The world magnetic models(WMMs) are selected as the criteria for comparison on the feasibility of geomagnetic declination investigation near unified control points. We compared deviations of declination from absolute measurement with that obtained from WMMs, also those from WMMs inter-comparison. The result through examination and analysis show that the feasibility of the absolute geomagnetic declination measurement with replacing the azimuth marks with UCP which established at suburb is possible.

• Korean Security Journal
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• no.16
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• pp.229-241
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• 2008

he guarding system of the "Choson" era is completed by the Gyeongguk-daejeon(an administrative canon) at the kings "Sejong" and "Yejong", and it is supplemented at the King "Seongjong". "Geum-gun" is composed of "Naegeum-wi", "Gyeombok-sa", "Wirim-wi" and "Jeongro-wi" in the period before the Japanese Aggression of Korea in 1952, and in the period after the aggression war, the organization of the "Geum-gun" is changed repeatedly according to circumstances in the period after the aggression. They("Geum-gun") devote themselves to the protection of kings and the capital defense in the first period of the "Choson" era. The most important change of the "Geum-gun" is the practice of five military units system, three military units of them, "Hunryeon-dogam", "Eoyeong-cheong" and "Geumwi-yeong", take charge of the guard of kings and the capital defense, and "Chongyung-cheong" and "Sueo-cheong" take charge of the defense of the outer areas of the capital region with key positions located at "Namhan-sanseong" and "Bukhan-sanseong"(mountain fortress Walls). The function of the "Geum-gun" is extended through the aggressions, therefore the number of soldiers is increased greatly. The guarding system for the country and its royal family is frequently changed according to the improvement of the people's position with themselves-awakening and their understanding of realities. The reorganization of the "Geum-gun" including "Howi-cheong", "Geumgun-cheong", "Sukwi-so" and "Jangyong-yeong" is unavoidable to strengthen the royal rights that are weaken by deposing the king "Injo". The standing of the existing organizations is changed many times with financial problems. The enthronement of the king "Jeongjo" is a great epoch in the change of the guarding system.

• Journal of Bio-Environment Control
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• v.6 no.3
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• pp.176-182
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• 1997

A simulation model for the analysis of the transmissivity of direct and diffuse solar radiation In glasshouse was developed. This model would be applicable to investigate the influences of time of year, orientation and slope of glasshouse, dimensions of the frames used, and latitude of the site on the transmissivity of direct and diffuse solar radiation in single-span or multispan glasshouse. The transmissivity of diffuse solar radiation was 60.4％ for the single-span glass-house. It was independent of both orientation and time of year, During the winter season, the transmissivity of direct solar radiation was 67~69％ for the E-W orientation single-span glasshouse, which was 14~16％ higher than that for the S-N orientation. Oppositely the transmissivity of direct solar radiation for the S-N orientation was higher than that for the E-W orientation. during the autumn season. There was no influence of the latitude In the country on the transmissivity of direct solar radiation.

• Journal of Satellite, Information and Communications
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• v.10 no.1
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• pp.56-61
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• 2015

In this paper, the 3D positioning of IoT sensors with the Unity engine of android platform based home-hub was proposde for IoT(Internet of Things) users. Especially, the monitoring of IoT sensor and battery status was designed with the clustering of IoT sensor's position. The 3D positioning of RSSI(received signal strength indicator) and angle for new IoT sensor according to clustering method was described with the cooperation of beacon and received arrival signal time. This unity engine based smart hub platform can monitor the working situation of IoT sensors, and apply 3D video with texture for the life-cycling of many IoT sensors simultaneously. rs was described with RSSI(received signal strength indicator) and received angle.

• Proceedings of the Korean Society for Bio-Environment Control Conference
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• 1998.05a
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• pp.39-44
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• 1998

현재 국내에 보급되어 있는 현대화 온실 203개를 대상으로 냉난방과 관련된 설비현황을 조사하여 분석한 결과를 요약하면 다음과 같다. \circled1 온실의 건설방위는 남북동(58.1%)과 동서동(26.8%)이 대부분이었고, 철골온실은 Wide-span형이 81.8%, 플라스틱온실은 1-2W형 온실이 97.5%였다. 휴작하는 온실은 약 41%정도였고, 재배작물은 채소류가 약 80%, 화훼류가 약 20%정도였으며, 재배방식은 철골온실의 경우 양액재배가 57.2%, 플라스틱온실에서는 토양재배가 88.5%였다. \circled2 온실의 외부 피복재는 철골온실은 유리가 92.2%, 플라스틱온실에서는 PE가 43.3%, EVA가 51.9%로 대부분이었다. 철골온실은 1중피복이 98.7%로 거의 전부이었고, 플라스틱온실에서는 2중피복이 78.7%로 나타나, 철골온실에서 보온커튼을 통한 보온성 향상과 밀폐성이 더욱 중요함을 알 수 있다. \circled3 보온용 피복재는 부직포가 64.9%로 가장 많았고 대부분 2층커튼(85.9%)이었으며, 개폐방식은 대부분 예인식(92.7%)의 자동개폐방식(75.2%)이었다. 한편 바닥을 피복한 온실은 약 30% 정도로 나타나, 바닥피복으로 인한 축열이나 반사효과를 감안할 때 효율적인 바닥처리가 요망된다. \circled4 온실의 난방방식은 철골온실에서는 온수안방(47.3%)이 온풍난방(33.8%)보다 다소 많았으며, 플라스틱온실에서는 대부분 온풍난방(90.8%)이었다. 온실의 난방위치는 대부분 지상난방(89.8%)이었고 지중난방은 극소수로 나타나, 앞으로 지중난방을 통한 난방비 절감과 품질향상에 관한 실용화 연구가 요망된다. 난방용 연료는 대부분 경유(83.9%)로 나타나, 난방비를 절감할 수 있는 저가의 연료를 사용할 수 있는 난방시스템의 개발이 요청된다. \circled5 온실의 냉방방법은 차광(51.8%)과 지붕살수(33.9%)가 대부분이었으며 미스트와 포그시스템을 설치한 온실은 소수에 불과하였고, 극소수의 온실에서는 지붕위나 온실내에 지붕면과 평행하게 설치한 경우도 있었다.

• Spatial Information Research
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• v.15 no.3
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• pp.335-346
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• 2007

Road sign is one of the road attached facilities to provide conveniences to motor drivers. The setup of location information according to the related regulation and the inclusion of various attributes such as place names, route numbers, symbols, bearings, distances to the place of interest distinguish the road sign from other facilities. These features give advantages to the informationization of road sign. Presently there established about 130,000 road signs on each class of roads, and about 280 road management offices have controlled these road signs independently, but there are plethora of ineffectiveness such as the lack of consistency, recognition, connectivity, and location suitability etc. These are the major factor of confusions rather than providing conveniences, and arisen a lot of public grievances. Accordingly, in this research the road signs throughout the nation were databased and the web-GIS based road sign management system was established to ameliorate the problems reveled. Since the road sign management system we developed reflected the demands of the persons in charge and users, the management effectiveness might be enhanced and the public inconveniences will be reduced.

• Korean Journal of Remote Sensing
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• v.34 no.5
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• pp.763-775
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• 2018

In this study, the effects of wind fences on the dispersion of the particles emitted from a constructing site located in the building-congested area in Busan, Korea, using geographic information system (GIS) and a computational fluid dynamics (CFD) model. We averaged the wind speeds observed for 10 years at the Busan automated synoptic observing system (ASOS) and we used the averaged wind speed as the wind speed at the reference height (10 m above the ground level). The numerical simulations were performed for 16 inflow directions, before and after the construction of wind fences with the heights of 5 m and 10 m (total 48 simulations). The detailed flows were analyzed for the northeasterly and south-southwesterly cases which predominantly observed at the Busan ASOS. In the northeasterly case, high concentration appeared at the elementary school next to the construction site due to transport by the airflow coming from the northeast. In the 5-m wind fence case, the wind speeds were slightly weaker and the spread of the fugitive dust was slightly less than those in the no wind fence case. In the 10-m wind fence case, the dust concentration at the elementary school has the maximum reduction of 37%. In the south-southwesterly case, the flow pattern became complicated in the construction site due to the terrain and buildings. Fugitive dust was stagnant at the south side of the construction site but rather spread to the north, increasing the concentration at the elementary school. After the wind fence was built, the concentrations inside the construction site became high as the wind speeds decreased inside, but, the concentrations in the elementary school rather decreased.