• Current Optics and Photonics
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• 제7권4호
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• pp.354-361
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• 2023

We present the optical design and experimental verification of resolving performance of a 3× long wavelength infrared (LWIR) zoom camera for drones. The effective focal length of the system varies from 24.5 mm at the wide angle position to 75.1 mm at the telephoto position. The design specifications of the system were derived from ground resolved distance (GRD) to recognize 3 m × 6 m target at a distance of 1 km, at the telephoto position. To satisfy the system requirement, the aperture (f-number) of the system is taken as F/1.6 and the final modulation transfer function (MTF) should be higher than 0.1 (10%). The measured MTF in the laboratory was 0.127 (12.7%), exceeds the system requirement. Outdoor targets were used to verify the comprehensive performance of the system. The system resolved 4-bar targets corresponding to the spatial resolution at the distance of 1 km, 1.4 km and 2 km.

• 에너지공학
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• 제19권3호
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• pp.195-202
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• 2010

최근 국내 연간 1차 에너지 사용량의 약 30% 이상이 폐열로 손실되어지고 있다. 이러한 현실을 타개하기 위하여, 본 논문에서는 장거리 열수송시 에너지 손실을 최소화할 수 있는 신기술로 화학 열변환을 이용한 장거리 열수송 기술을 채택하여, 화학 열변환에 있어서의 최적조건 도출을 목적으로 하였다. 화학 열변환을 위한 반응에 대해서는 많은 연구와 기술개발이 이루어지고 있으며, 그 중 물질이 안정하고, 값이 저렴하며, 생성물이 가스인 메탄올 분해 합성 반응이 가장 타당한 것으로 판단되었다. 본 연구에서는 장거리 열수송 기술 개발에 필요한 메탄올 분해 합성 반응 촉매를 각각 선정하여, 열수송 시스템 구축을 위한 메탄올 분해 합성 반응의 최적화 조건 도출을 위한 실험 연구를 수행하였다. 메탄올 합성 반응에서는 온도, 압력, $H_2$/CO ratio, 공간 속도, 촉매 형태에 따른 영향을 보았고, 메탄올의 분해 반응에서는 온도, 공간속도, 촉매 형태를 변수로 하여 상압에서 영향을 분석하여 메탄올 분해 합성 반응의 최적화 조건을 제시하였다.

• 농촌계획
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• 제17권3호
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• pp.55-65
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• 2011

Long distance trail or trail system planning is the first important step in transforming your vision into reality. Planning presents a vision for a trail or trail system and brings a comprehensive, long-range perspective. The master plan provides solid, credible recommendations for developing a trail or trail system that is safe, convenient, well used, supported by local residents, practicality to implement, and customized to meet the needs of the community, you will need to follow a logical planning. The key elements of master planning includes site assessment, vision, goals and objectives, routing and design, implementation strategies. Trails or trail systems should provide linkages to popular destinations, safely accommodate a variety of users, and be sensitive to any negative impacts on the natural environment and wildlife. Trails planners also need to think about how the trail, or trail system will function in the future as areas are developed or trail population increases. All of these factors during the planning process will ensure the existence of high-quality facilities for years to come. Project for Nakdong-jungmaek trail planning combine long distance trail with circuit way. That project is a planning brought out the best in each of Tokai natural way and Cotswold way. That is planning which is combined a wooded trail in Tokai natural way with access and facilities improving economy in Cotswold way. Also That planning embraces a core cultural center which is concerned forest or wood to come more people.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제11권1호
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• pp.78-101
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• 2017

High-quality industrial control is critical to ensuring production quality, reducing production costs, improving management levels and stabilizing equipment and long-term operations. WiFi-based Long Distance (WiLD) networks have been used as remote industrial control networks. Real-time performance is essential to industrial control. However, the original mechanism of WiLD networks does not minimize end-to-end delay and restricts improvement of real-time performance. In this paper, we propose two algorithms to obtain the transmitting/receiving phase cycle length for each node such that real time constraints can be satisfied and phase switching overhead can be minimized. The first algorithm is based on the branch and bound method, which identifies an optimal solution. The second is a fast heuristic algorithm. The experimental results show that the execution time of the algorithm based on branch and bound is less than that of the heuristic algorithm when the network is complex and that the performance of the heuristic algorithm is close to the optimal solution.

• 복식문화연구
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• 제18권5호
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• pp.1048-1061
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• 2010

The purpose of the study was to compare the culture and the clothing value between Korean and American college students, especially men. Also, this study was to analyze the culture effect on the clothing value. The survey was performed and 200 questionnaires were utilized for this study. The SPSS 12.0 was used to analyze the technical statistics like average, frequency, t-test, factor analysis, multiple regression analysis. The result showed, first, there were some 2 major cultural differences such as power distance and long-term orientation between Korean and American college men. Comparatively, Korean college men showed higher masculinity and lower power distance and long-term orientation. Second, there were differences in the clothing value aspect. Both of them considered the economic clothing value to be most important. Third, there were some differences in the clothing value because of the cultural differences. For Korean college men, there were masculinity and long term orientation that had an effect on the social and religious clothing values, however, for American college men, power distance, masculinity and long term orientation that had an effect on the social, religious, theoretical and economic values.

• Journal of Biosystems Engineering
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• 제41권4호
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• pp.319-327
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• 2016

Purpose: Automated guidance systems (AGSs) for mobile farm machinery have several advantages over manual operation in the crop production industry. Many researchers and companies have tried to develop such a system. However, it is not easy to evaluate the performance of an AGS because there is no established device used to evaluate it that complies with the ISO 12188 standard. The objective of this study was to develop a tracking sensor system using five laser distance measurement sensors. Methods: One sensor-for long-range distance measurement-was used to measure travel distance and velocity. The other four sensors-for mid-range distance measurement-were used to measure lateral deviation. Stationary, manual driving, and A-B line tests were conducted, and the results were compared with the real-time kinematic differential global positioning system (RTK-DGPS) signal used by the AGS. Results: For the stationary test, the average error of the tracking sensor system was 1.99 mm, and the average error of the RTK-DGPS was 15.19 mm. For the two types of driving tests, the data trends were similar. A comparison of the changes in lateral deviation showed that the data stability of the developed tracking system was better. Conclusions: Although the tracking system was not capable of measuring long travel distances under strong sunlight illumination because of the long-range sensor's limitations, this dilemma could be overcome using a higher-performance sensor.

• 한국운동역학회지
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• 제13권1호
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• pp.63-72
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• 2003

This study is examine and analysis of the most flying and run distance during swing three times with six balls between two amateurs and pro-golfers in golf field in Sungnam airport. During down swing, kinetics variances are velocity of club-head and balls, vertical angular velocity. this scientic data present amateur golfers with recognition of long flying distances for golf balls. Through this study, the conclusions are as follows. 1. Before impact the balls, The club-head velocity of amateur golfers and pro-golfers show 33.34 - 39.53m/s, 39.04 - 42.82m/s respectively during the down swing. But The club-head velocity, flight and Run distances comparative $K_1$ amateur golfer with the pro-golfer are similar. 2. After impact the balls, The balls velocity if amateur golfers show 53.04 - 61.57m/s, The pro-golfers show 62.32 - 63.4m/s respectively during the down swing. In case of $K_3$,$K_4$, After the impact balls velocity comparative The RA brand with other brand are similar, Flight and Run distance are difference. 3. After impact the balls, The balls velocity are difference to other brand but The long flight and Run distance arrange RA, BIG, TITL. 4. In the vertical flight angle of the ball after impact, amateur golfer showed 16.75 - $18.73^{\circ}$. The pro-golfer showed 15.03 - $16.04^{\circ}$. In the vertical flight angle of the balls ideal $12-13^{\circ}$, The long flight and Run distance approach In the vertical flight angle the balls $12-13^{\circ}$.

• 한국광학회지
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• 제32권2호
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• pp.79-85
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• 2021

본 논문에서는 빔 확산각 최소화를 통해 장거리에서 측정이 가능하도록 한 ToF 레이저 거리센서 광학계 설계에 대한 연구를 진행하였다. 거리센서는 장거리 측정 시 거리가 멀어질수록 레이저 빔의 확산각으로 인해 물체 표면에 도달하는 빔의 광량이 급격히 저하되며, 이로 인해 센서에 수신되는 광량도 감소되어 측정이 되지 않거나 측정 오차가 발생하게 된다. 일반적으로 빔 확산각을 최소화하는 광학계로 실린더 렌즈가 사용된다. 그러나 실린더 렌즈를 이용한 광학계는 광학계 크기가 커지는 문제뿐만 아니라 조립 공차의 어려움으로 인해 성능이 저하된다는 문제점이 있어 최근 비구면 렌즈를 사용하는 추세가 증가하고 있다. 따라서 본 연구에서는 실린더 렌즈를 이용한 광학계와 비구면 렌즈를 이용한 광학계의 광효율과 조립공차를 비교 분석하고자 한다.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2000년도 추계종합학술대회 논문집(1)
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• pp.133-136
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• 2000

Generally in the case of mobil communication service for long distance sea, unlike heavily populated residential areas, providers need to minimize the service area per base station. Therefore, in this thesis, the 800 ㎒ CDMA system should be extended to give better long distance communication service. This model is used to predict the occurring receiving power of the mobile stations that we simulated and analyzed. As a result, the experiment demonstrated the appropriateness of predicting receiving power using this model.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1997년도 추계학술대회 논문집
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• pp.504-506
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• 1997

CCD camera is usually used for monitoring device. In most cases, he monitoring is performed from long distance. In this study, a camera system controlled through internet is developed. Using the system, not only we can get image information in real time but also we can control the orientation of the camera from long distance. Furthermore wireless communication is carried out between the camera and the server computer for verity of the application.