• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2014.10a
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• pp.280-282
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• 2014

DMB 기반 DGPS 시스템은 기존 중파 DGPS의 음영구역 해소 및 내륙에서의 DGPS 이용자 활성화를 목적으로 개발된 전달매체이다. 본 연구는 향후 유동인구와 교통량이 많아 이용 수요가 크게 예상되며, 멀티패스 등의 영향으로 측위 오차가 큰 도심에서 저가형 수신기를 이용하여 실제 기준국 및 가상 기준국의 DGPS 보정정보를 DMB 기반으로 수신하여 수신환경 수신기별 정지측량과 이동측위를 측정한 결과를 분석하였다.

• The Journal of the Acoustical Society of Korea
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• v.10 no.2
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• pp.52-60
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• 1991

Sound propagation in a sloping sea bed ocean environment demonstrates ray curvature in a direction parallel to the shoreline. The theoretical analysis of this shows that an ensonified region and a shadow region are formed, and their spatial extents depend on the spatial coordinates of source and receiver, a sloping angle and sourece frequency. The purpose of this experimental study using a sloping sea bed model is to check the theoretical prediction as a part of an ongoing investigation in the ocean environment. The sloping sea bed model used in this experiment had an ideal pressure-release boundaries and a sloping angle of $220.5{\circ}$ A single frequency signal and an impulsive signal were used as omnidirectional point sources. The spatial acoustic field characteristics in the across slope direction were measured using the former and the frequency dependent field characteristics in a specific point were obtained using the latter. It has been found that the analysis for the spatial extent of shadow zone and the frequency dependent field characteristics in the across slope direction, has a good agreement with the theoretical solution.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2022.09a
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• pp.85-85
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• 2022

영농형 태양광발전은 태양의 일사량을 전기발전과 영농에 공유하는(solar-sharing) 방식이다. 본 연구는 신재생에너지의 활용의 극대화를 위하여 추적식 영농형 태양광발전시스템을 구축하고 시설하부에서 일정 기간 재배중인 작물의 하부 환경과 생육을 조사하여 영농형태양광 하부작물개발을 위한 기초자료를 확보하고자 하였다. 구축한 추적식 영농형 태양광발전시스템은 4열 6단의 24장 모듈(8m × 6m)을 가지며, 발전시설 중심축 기둥 간 중심간격 14m로 단일지주식 스크루 공법으로 순천대학교 부속농장 답작포(순천시 죽평리)에 설치하여 하부 환경과 하부작물의 생육을 조사하였다. 태양광발전시설 하부작물의 생육을 조사하기 위하여 순천 농협육묘장에서 벼(신동진)를 육묘하여 2022년 6월 16일 이앙하였다. 태양광발전시스템 하부 지역을 4방위 방향에 따라 강음영(중심축으로부터 1~3m), 중음영(5m), 약음영(7~9m) 구역으로 설정하여 생육을 조사한 결과, 방위에 따른 초장은 남쪽에서 음영간 차이가 상대적으로 낮게 나타났으며, 1번기 태양광 발전시설에 의하여 음영이 중첩된 2번기 시설의 동쪽에서 대조구 대비 초장이 상대적으로 낮은 경향을 나타내었다. 음영강도에 따른 초장은 대체로 강음영구에서 낮게 나타났으며, 약음영구로 갈수록 높게 나타났다. 엽수는 방위에 따라서, 그리고 음영의 강도에 따른 차이가 초장에 비하여 작게 나타났다. 출수기의 경우 방위별로는 남쪽에서 음영별 차이가 작게 나타났으며, 음영강도에 따라서 차이를 보였다. 또한 태양광시설 하부에 데이터수집장치(Model 1650, Spctrum Technonogies, USA)를 설치하여 음영에 따른 토양전도도, 토양함수량, 토양온도, par light 등 생육환경을 조사, 비교하였다.

• Journal of Korean Society of Transportation
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• v.20 no.5
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• pp.55-66
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• 2002

In many countries the principle of shielding is employed to permit a more logical approach to restricting new construction and prescribing obstacle marking and lighting. It also reduces the number of cases of new construction requiring review by authorities. Shielding principles are employed when some object, an existing building or natural terrain, already penetrates above one of the obstacle limitation surfaces described in Annex 14. If it is considered that the nature of an object is such that its presence may be permanent, then additional objects within a specified area around it may be permitted to penetrate the surface without being considered as obstacle. The shielding effect of immovable obstacles laterally in final approach and missed approach areas is more uncertain. In certain circumstances, it nay be advantageous to preserve existing unobstructed cross section areas, particularly when the obstacle is close to the runway. This would guard against future changes in either approach or take-off climb area specifications or the adoption of a turned take-off procedure.

• Journal of Chest Surgery
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• v.30 no.8
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• pp.843-846
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• 1997

Congenital bronchial atresia is one of the rare bronchopulmonary anomalies which is thought to be caused by a vascular insult of uncertain timing during fefal development. It is defined as an anomaly which does not have communication between a segmental or lobar bronchus a'nd the main airway. Because of the collateral ventilation, almost all of these cases show hyperlucency of the involved segment or lobe in chest roentgenogram. We report an extremely rare case of congenita bronchial atresia with collapse of the right upper lobe which was treated by surgical resection.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.16 no.12 s.103
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• pp.1206-1212
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• 2005

In this paper, we propose a novel antenna structure which uses the electric and magnetic currents so as to eliminate nulls on their radiation pattern. The tag antenna was matched to the conjugate impedance of the commercial tag chip using the modified double T matching network. The radiation efficiency is about $90\%$, and the bandwidth($S_{11}< -10 dB$) is 848${\~}$926 MHz. Also it shows the gain deviation between the maximum and minimum gains about 4 dB at any direction of the tag antenna at the operating frequency. The readable range of the tag is 1.7${\~}$2.4 m for an arbitrary rotation angle of the tag with a commercial tag chip.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.39 no.4
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• pp.347-357
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• 2003

This paper describes on the suppression of sea clutter on marine radar display using a cell-averaging CFAR(constant false alarm rate) technique, and on the analysis of radar echo signal data in relation to the estimation of ARPA functions and the detection of the shadow effect in clutter returns. The echo signal was measured using a X -band radar, that is located on the Pukyong National University, with a horizontal beamwidth of $$3.9^{\circ}$$, a vertical beamwidth of $20^{\circ}$, pulsewidth of $0.8 {\mu}s$ and a transmitted peak power of 4 ㎾ The suppression performance of sea clutter was investigated for the probability of false alarm between $l0-^0.25;and; 10^-1.0$. Also the performance of cell averaging CFAR was compared with that of ideal fixed threshold. The motion vectors and trajectory of ships was extracted and the shadow effect in clutter returns was analyzed. The results obtained are summarized as follows；1. The ARPA plotting results and motion vectors for acquired targets extracted by analyzing the echo signal data were displayed on the PC based radar system and the continuous trajectory of ships was tracked in real time. 2. To suppress the sea clutter under noisy environment, a cell averaging CFAR processor having total CFAR window of 47 samples(20+20 reference cells, 3+3 guard cells and the cell under test) was designed. On a particular data set acquired at Suyong Man, Busan, Korea, when the probability of false alarm applied to the designed cell averaging CFAR processor was 10$^{-0}$.75/ the suppression performance of radar clutter was significantly improved. The results obtained suggest that the designed cell averaging CFAR processor was very effective in uniform clutter environments. 3. It is concluded that the cell averaging CF AR may be able to give a considerable improvement in suppression performance of uniform sea clutter compared to the ideal fixed threshold. 4. The effective height of target, that was estimated by analyzing the shadow effect in clutter returns for a number of range bins behind the target as seen from the radar antenna, was approximately 1.2 m and the information for this height can be used to extract the shape parameter of tracked target..

• Pediatric Infection and Vaccine
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• v.24 no.3
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• pp.178-182
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• 2017

Paragonimiasis was one of the most common causes of cavitary lung lesions until the 1960s, but now it has become a very rare disease in Korea. A 16-year-old boy presented with hemoptysis and several days of cough. His plain chest radiograph showed nodular opacity with a cavity in the left upper lung region. Although his symptoms disappeared after taking antituberculous drugs, his plain chest radiograph and computed tomography images after completion of therapy showed a new nodule with a cavity in the left lung field. Through video-assisted thoracoscopic wedge resection, Paragonimus eggs were found in the lung tissues.

• Journal of Korean Society for Geospatial Information Science
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• v.16 no.1
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• pp.49-55
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• 2008

The face extraction is very important to provide the images of the roads and road sides without the problem of privacy. For face extraction form roadside images, we detected the skin color area by using HSI and YCrCb color models. Efficient skin color detection was achieved by using these two models. We used a connectivity and intensity difference for grouping, skin color regions further we applied shape conditions (rate, area, number and oval condition) and determined face candidate regions. We applied thresholds to region, and determined the region as the face if black part was over 5% of the whole regions. As the result of the experiment 28 faces has been extracted among 38 faces had problem of privacy. The reasons which the face was not extracted were the effect of shadow of the face, and the background objects. Also objects with the color similar to the face were falsely extracted. For improvement, we need to adjust the threshold.

• Journal of the Korea Institute of Military Science and Technology
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• v.13 no.2
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• pp.211-217
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• 2010

This paper introduces the Hull Mounted Sonar Vertical Scanning(HMS Verscan) technique to overcome the limitation of target detection in short range shadow zone. Numerical experiments were done with the HMS Verscan taking advantage of the vertical beamforming technique for two-dimension hydrospace(range-depth). For numerical experiments, ray model and high-frequency monostatic reverberation model were used. HMS Verscan increased a sound pressure level at the short range shadow zone through reflections at the sea surface and seafloor. Inclusion of the boundary scattering improved target detection due to the sound reflected into the shadow zone.