• Proceedings of the Korean Vacuum Society Conference
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• 2010.02a
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• pp.252-252
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• 2010

적외선 센서는 빛의 유무에 관계없이 주 야간 전방의 물체에서 발산하는 미약한 적외선(열선)을 감지하여 영상으로 재현하는 열상시스템은 자동차 야간 운전자 보조용 나이트 비젼, 핵심 시설의 감시 관리, 군수 등의 분야에 적용되어지고 있는 최첨단, 고부가가치를 지니고 있는 기술이다. 양자형은 센서 특성은 좋으나 냉각기(작동온도: $-196^{\circ}C$) 및 고진공 패키지인 dewar를 사용하는 반면에, 열형은 대부분 상온에서 동작되는 온도안정화를 위한 전자냉각모듈만을 구비하면 되므로 저가형으로 제작이 가능한 비냉각형 적외선 센서이다. 본 연구에서는 적외선 센서용 진공패키지 조립공정 및 패키지된 센서의 측정기술을 개발하였다. 금속 메탈패키지를 제작하였으며, 금속 진공패키지는 소자냉각용 TE Cooler와 장수명 진공유지를 위한 getter, 그리고 센서칩, 온도센서를. 장착하여 칩을 조립하였다. Cap ass'y와 base envelop의 솔더링 공정을 수행하였으며, 진공패키지의 진공유지를 위해 TMP를 이용하여 진공을 유지하고, 약 5일동안 패키지 bake-out을 수행하였다. 진공압력은 $10^{-7}\;torr$ 이하를 유지하였으며, getter를 활성화시키고, pinch-off 공정으로 조립 ass'y를 완성하였다. 진공 패키지의 기밀성은 He leak tester를 이용하여 측정하였으며, ${\sim}10^{-9}\;std.cm^3/sec$로 기밀성을 유지하였다. TE cooler를 작동한 온도안정성은 0.05 K 이하였다. 볼로미터 센서의 반응도는 $10^2\;V/W$ 이상을 나타내었으며, 탐지도는 $2{\times}10^8cm-Hz^{1/2}/W$를 나타내었다. 본 연구를 통하여 얻어진 결과는 향후 2차원 열영상용 어레이 검출기 및 웨이퍼수준의 패키징 공정에 유용하게 응용될 것으로 판단된다.

• Journal of Advanced Navigation Technology
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• v.8 no.2
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• pp.112-119
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• 2004

This paper proposes an attitude determination GPS/INS integrated system scheme for a UAV and presents experimental flight test results. The proposed system is designed as a part of an autopilot system and comprises a GPS attitude determination receiver, an off-the-shelf inertial measurement unit (IMU), and a navigation computer unit (NCU). UAV requires accurate attitude information for stable automatic flight control. The proposed system can provide accurate attitude information for the flight control computer (FCC) so that stable automatic flight control can be achieved. In order to verify the performance of the proposed scheme, an integrated navigation system has been developed. In order to evaluate the developed navigation system, the flight test has been performed. In the flight test, the developed system was shown to provide the position, the velocity and the attitude satisfactorily enough for stable flight control. The accuracy of the attitude information of the developed system was confirmed by comparing attitude of vertical gyro.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.19 no.5
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• pp.181-186
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• 2019

In order to reduce the fossil fuels consumed in conventional commercial independent diesel generators in the same environment as the island area, it is necessary to develop a photovoltaic system that will bear more than 40% of the independent system capacity. For this development, it is necessary to develop a high-capacity inverter that can improve the stability of the independent system installed in the island area and supply high-quality power to the load. In addition, the EMS power generation control system for the independent grid photovoltaic power generation system is a parallel operation power control system of the diesel generator connected with the solar power generation system. It controls the output of the diesel generator according to the load ratio and the solar power generation, A stable supply system is needed. This independent grid photovoltaic generation system can increase the solar power supply to the independent system area and increase the power stability of the independent system and further reduce the use of fossil fuel due to the ineffective power control of the independent system. It is expected that the economy will be secured early.

• Health Policy and Management
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• v.31 no.4
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• pp.518-530
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• 2021

Background: This study examined the effect of having a usual source of care on the degree of patient-centered communication among persons with disability. The role of the usual source of care has been emphasized to improve patient experience, especially for patients with complex health conditions. Methods: This study used the 2017-2018 Korean Health Panel data, and the final study observations were 22,475 (20,806 people without disability and 1,669 people with disability). We applied generalized estimating equation model to show the effect of having a usual source of care on patient-centered communication, and subgroup analysis considering the types and severity of disabilities. Results: Persons who have disabilities, compared with ones without it, significantly had more usual sources of care (32.4% vs. 24.6%). By type of disability, persons with mental (51.4%), internal organ (43.8%), visual (37%), and physical disabilities (31.6%) had more usual sources of care than hearing/speech (26.6%), and developmental disabilities (18.6%). The average score of patient-centered communication was higher among who had a usual sources of care (3.2 vs. 2.7), and the regression analysis showed that having a usual sources of care was positively associated with higher patient-centered communication score (𝛽=0.476, p<0.05). However, the positive effects of usual sources of care was not observed among persons with severe hearing/speech, developmental, and mental disabilities. Conclusion: This study showed that role of patient-centered communication was limited in persons with severe hearing/speech disabilities, developmental, and mental disabilities. The education programs and supports are needed to improve communication skills between medical staff and persons with specific types of disabilities.

• Journal of Technologic Dentistry
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• v.40 no.4
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• pp.273-281
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• 2018

목적: 본 연구는 실무 현장과 교육 현장의 조사를 통한 종합적인 의견을 수렴하여 합리적인 치과기공사 양성 및 배출을 위한 개선안을 도출하고자 한다. 방법: 3회에 걸쳐 설문조사가 진행되었으며, 1차는 개방형 문항으로 조사되었고, 2차, 3차는 폐쇄형 문항으로 조사되었다. 델파이 조사를 위한 조사 인원 선정을 100명(정책집단: 20명, 교육집단: 20명, 임상가 집단: 60명)으로 지정하였다. 1차 개방형 조사결과를 토대로 2차 설문문항을 작성하였으며, 2차 설문조사 결과를 토대로 3차 설문문항을 작성 후 조사하였다. 수집된 자료의 분석은 통계패키지 프로그램 SPSS Ver. 21.0를 활용하여 델파이 기법(Delphi Method)을 활용한 연구 결과에서 전문가 집단의 의견을 수렴하기 위해 빈도분석과 기술통계분석을 실시하였다. 결과: 현 교육체계의 문제점은 임상현장과의 차이와 실무능력저하, 국가시험위주의 교육이 문제점으로 대두되었으며, 현행 평가제도의 문제점은 임상현장을 충분히 반영하지 못한 점, 실무능력이 미 반영된 실기평가로 지적되었다. 결론: 결론적으로 치과기공사의 교육과정과 평가제도는 현실적인 내용을 고려하면서 임상 실무와의 연계성을 높이는 방향으로 개선되어야 할 것으로 사료된다.

• Journal of the Korean Society of Marine Environment & Safety
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• v.27 no.2
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• pp.369-376
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• 2021

The International Maritime Organization has developed the Energy Efficiency Design Index, an index related to carbon dioxide emissions, to enforce regulations on newly built ships. In this study, a new type of energy-saving device called the ring stator was used for 158k crude oil carriers, whose hull form was developed as a very thin after-body hull to reduce the resistance by delaying separation. The Energy-Saving Device (ESD) particularly involving the duct, is not adapted to the thin-after body hull form-like container ship. This new ring stator was developed considering these characteristics. A parametric study was conducted through Computational Fluid Dynamics (CFD) analysis using the Star-CCM+ program, and approximately 3.4 % improvement in propulsion efficiency was achieved. Further optimization investigations and experimental studies should be conducted in the future.

• Journal of Internet Computing and Services
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• v.23 no.3
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• pp.1-12
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• 2022

As the performance of Unmanned Aerial Vehicles (UAVs) are improving and the prices are lowering, it is expected that the use of UAVs will continuously grow in the future. It is important to always maintain control signal and video communication to operate remote UAVs stably, especially in military UAV operations, as unexpected jamming attacks can result in fatal UAV crashes. In this paper, to improve the network reliability and low latency when supporting UAV operations, the anti-jamming performance of Second generation Anti-jam Tactical UHF Radio for NATO (SATURN) networks is analyzed and enhanced by applying Forward Error Correction (FEC) and Minimum Shift Keying (MSK) modulation as well as Hamming code based multiple transmission techniques.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.39 no.6
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• pp.401-408
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• 2021

With the proposal of amendments to the Pedestrian Safety Act in 2021, when the amendment bill is passed in the near future, a general dimensional investigation of the sidewalks' physical condition, which is the basis of pedestrian safety, is expected to be legislated and made mandatory. Therefore, this study presented a affordable methodology for street environment survey using entry-level drones and examined the feasibility of conducting a complete survey of pedestrian paths by local governments nationwide. To this end, various street facilities in the experimental site were measured to compare and analyze the accuracy of the point cloud data. As a result of the analysis, it was found that the measurement error range satisfies the public surveying guidelines. If the methodology presented in this study is applied, it is expected that individual local governments will be able to make a significant contribution to monitoring the physical conditions of streets to improve the pedestrian environment in the near future.

• Asia-pacific Journal of Multimedia Services Convergent with Art, Humanities, and Sociology
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• v.8 no.1
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• pp.867-874
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• 2018

This study aims to develop a sort of expert system to simulate Internet of Things (IoT) service in architectural design alternatives and enhance the simulation performance using building information. The proposed protype system, named iotBIM, visualizes human behaviors and IoT services in a virtual place that is automatically generated from among design alternatives. We use commercial building information modeling (BIM) authoring tool for the development of iotBIM. The decision to develop iotBIM on the BIM platform was made because BIM tools already generate precise 3D models of design alternatives; iotBIM is plugged into the BIM tool as a simulation module. In the midst of the design process, architectural designers can activate iotBIM to investigate and establish IoT services that accord visually with design alternatives. The purpose of this study is to provide a theoretical and technological basis for the ultimate goal of this study.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.30 no.3D
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• pp.271-278
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• 2010

Semi rigid pavement is a pavement type using advantages of both flexibility of asphalt pavement and rigidity of concrete pavement by infiltrating cement paste into voids of open graded asphalt mixtures. The semi rigid pavement has better smoothness and smaller driving vibration or noise comparing to the concrete pavement, and has smaller permanent deformation and has temperature falling effect comparing to the asphalt pavement. The temperature falling effect were investigated at a semi rigid overlay pavement test section, and the temperature falling and water retaining effects were verified by measuring the temperature and weight of specimens at a housetop. Horizontal and vertical stresses and strains were compared by structural analysis of the semi rigid pavement and asphalt pavement using the Abaquser o, a commercial 3D finite element analysis program. The results were verified by Bisar 3.0, a multi-layered elastic analysis program. Performance of the semi rigid pavement and asphalt pavement were compared by predicting fatigue cracking based on the structural analysis results.