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거리독립 해양환경에서 고속이동 음원의 고주파 잔향음 신호모의
김선효,이원병,유승기,최지웅,김우식,박정수,박경주,Kim, Sunhyo,Lee, Wonbyoung,You, Seung-Ki,Choi, Jee Woong,Kim, Wooshik,Park, Joung Soo,Park, Kyoung Ju 한국음향학회 2013 韓國音響學會誌 Vol.32 No.2
천해 환경에서 고주파 능동소나를 운용할 경우 각 경계면에서의 잔향음 및 도플러 효과는 소나 운용에 제한요소로 작용한다. 따라서 잔향음 제한 환경에서 소나 시스템을 운용하기 위해서는 그 환경 조건에서 발생하는 잔향음 준위를 예측하는 것이 중요하다. 본 논문에서는 거리 독립 환경에서 고속으로 이동하는 음원에서 수신되는 잔향음 신호를 모의할 수 있는 고주파 잔향음 모델을 제안한다. 본 모델에서는 음선 이론과 음선 송신각 최적화 방법을 이용하여 음원에서 각 경계면까지의 고유음선 정보를 계산하고, 이동하는 음원에 의해 변화된 음원 수신 위치는 음속 그리고 음원의 방향 및 속도를 고려한 산란경로 탐색 알고리즘에 의하여 계산된다. 또한 해수면 및 해저면에서의 산란 효과는 APL-UW 산란 모델을 적용하여 고려한다. 본 논문에서 제안한 잔향음 모델은 2010 년 8월 측정된 실험과 비교 검증된다. 본 논문에서 제안된 잔향음 모델은 잔향음 신호의 통계적 특성을 잘 반영하도록 개발되었다. In a shallow water waveguide, reverberation signals and their Doppler effects form the primary limitation on sonar system performance. Therefore, in the reverberation-limited environment, it is necessary to estimate the reverberation level to be encountered under the conditions in which the sonar system is operated. In this paper, high-frequency reverberation model capable of simulating the reverberation signals received by a high-speed moving source in a range independent waveguide is suggested. In this model, eigenray information from the source to each boundary is calculated using the ray-based approach and the optimizing method for the launch angles. And the source receiving position changed by the moving source is found by a scattering path-finding algorithm, which considers the speed and direction of source and sound speed to find the path of source movement. The scattering effects from sea surface and bottom boundaries are considered by APL-UW scattering models. The model suggested in this paper is verified by a comparison to the measurements made in August 2010. Lastly, this model reflects well statistical properties of the reverberation signals.
김선효,김우중,최지웅,윤영중,박정수,Kim, Sunhyo,Kim, Woojoong,Choi, Jee Woong,Yoon, Young Joong,Park, Joungsoo 한국군사과학기술학회 2015 한국군사과학기술학회지 Vol.18 No.5
The goal of this study is to develop an algorithm to propose optimal deployment of detection sensor nodes in the target area, based on a performance surface, which represents detection performance of active and passive acoustic sonar systems. The performance surface of the active detection system is calculated from the azimuthal average of maximum detection ranges, which is estimated with a transmission loss and a reverberation level predicted using ray-based theories. The performance surface of the passive system is calculated using the transmission loss model based on a parabolic equation. The optimization of deployment configurations is then performed by a hybrid method of a virtual force algorithm and a particle swarm optimization. Finally, the effectiveness of deployment configurations is analyzed and discussed with the simulation results obtained using the algorithm proposed in this paper.
우리나라 고등학생의 식품 및 영양소 섭취 변화 추이 - 2007~2015 국민건강영양조사를 이용하여 -
김선효,Kim, Sun Hyo 한국식품영양학회 2020 韓國食品營養學會誌 Vol.33 No.5
This study assessed yearly trends of food and nutrient intake among high school students aged 16 to 18 years (n=2,377) using the 2007~2015 Korea National Health and Nutrition Examination Survey (KNHANES). Yearly trends of food or nutrient intake were analyzed via logistic regression analysis. The results showed that consumption of sugars & sweets, and beverages & alcohols was increased rapidly during this period (p<0.0001). Intake of meat & meat products, and fish & shellfish also was increased (p=0.0008). Intake of grains and grain products was increased until year 2011 but declined after 2012 (p=0.0025). Consumption of vegetables, and milk & milk products was decreased (p=0.0395). Intake of protein, fat, thiamin, riboflavin, niacin, and iron was increased (p=0.0445). Carbohydrate energy ratio was decreased, whereas fat energy ratio was increased (p=0.0235). Most nutrient intakes satisfied the dietary reference intakes for Koreans except dietary fiber (19.6~26.2%), calcium (46.9~55.2%) and sodium (more than 221.4%) during this period. There was a significant positive correlation between most food group intakes and most nutrient intakes (p=0.0468). Therefore, it is crucial to increase dietary fiber and calcium intake and decrease consumption of sugars, fats and sodium through diverse eating of food groups to ensure balanced nutrition of subjects.
수중합성환경에서 단상태 능동소나의 성능분석을 위한 표적신호 모의
김선효,유승기,최지웅,강돈혁,박정수,이동준,박경주,Kim, Sunhyo,You, Seung-Ki,Choi, Jee Woong,Kang, Donhyug,Park, Joung Soo,Lee, Dong Joon,Park, Kyeongju 한국음향학회 2013 韓國音響學會誌 Vol.32 No.6
능동소나는 일반적으로 천해에서 존재하는 표적을 탐지하기 위해 사용된다. 신호가 송신되고 표적으로부터 반향되어 되돌아올 때, 표적 반향신호는 다중경로, 거친 해저면 또는 해수면에 의한 산란 그리고 음속구조에 의한 굴절과 같은 다양한 음파전달 특성에 의해 왜곡 되어 수신되며, 이는 표적 탐지를 어렵게 만든다. 그러므로 능동소나의 운용성능 체계에서 표적 신호 모의 시 음파전달 특성을 고려하는 것이 필요하다. 본 논문에서는 단상태 능동소나 시스템을 고려하였으며, 표적 반향, 잔향음 그리고 주변소음은 각각 시계열 함수로 모의되었다. 마지막으로 전체 수신 신호를 모의하기 위해 위 신호들을 합하였다. 표적의 특징(형태, 위치, 자세각 등)을 반영한 3차원 대표반향점 모델은 음원과 표적 사이에 각각의 다중경로를 고려하여 표적 반향 신호를 모의하였다. 본 논문의 결과는 표적 신호 모의 시 직접파만을 고려한 알고리즘의 결과와 비교하였다. Active sonar has been commonly used to detect targets existing in the shallow water. When a signal is transmitted and returned back from a target, it has been distorted by various properties of acoustic channel such as multipath arrivals, scattering from rough sea surface and ocean bottom, and refraction by sound speed structure, which makes target detection difficult. It is therefore necessary to consider these channel properties in the target signal simulation in operational performance system of active sonar. In this paper, a monostatic active sonar system is considered, and the target echo, reverberation, and ambient noise are individually simulated as a function of time, and finally summed to simulate a total received signal. A 3-dimensional highlight model, which can reflect the target features including the shape, position, and azimuthal and elevation angles, has been applied to each multipath pair between source and target to simulate the target echo signal. The results are finally compared to those obtained by the algorithm in which only direct path is considered in target signal simulation.
김선효(Sun Hyo Kim),김민우(Min Woo Kim),김정호(Jung Ho Kim),왕립(Lih Wang) 대한정형외과학회 2019 대한정형외과학회지 Vol.54 No.3
간세포암은 전 세계적으로 가장 흔한 악성 종양 중의 하나로, 간세포암의 간 외 전이는 주로 폐, 림프절, 뼈, 부신 등에 발생한다. 하지만 간세포암의 골격근 전이는 매우 드물고, 보고된 문헌도 흔치 않다. 42세 여성 환자가 우측 대퇴부에 압통이 동반된 연부조직 종괴를 주소로 내원하였다. 7년 전 간세포암과 폐전이가 진단되어 치료를 받은 기록이 있었으며 영상학적 검사 및 혈액 검사 결과 등에서 간세포암의 반막양근 내 전이가 의심되어 절개 생검술을 시행하였고 전이성 간세포암으로 밝혀져 광범위 절제술을 시행하여 치료하였다. 이를 문헌고찰과 함께 보고하고자 한다. Hepatocellular carcinoma is one of the most common cancers worldwide. Extrahepatic metastasis commonly occur in the lung, lymph, nodes, bone, and adrenal glands. On the other hand, a metastasis of hepatocellular carcinoma to the skeletal muscle is rare. A 42-year-old woman presented for evaluation of a palpable mass with tenderness in her right thigh area. She has been diagnosed with hepatocellular carcinoma and pulmonary metastasis seven years ago and has received treatment. We performed incisional biopsy with suspicion of hepatocellular carcinoma metastasis from imaging studies and blood test results. The patient was finally diagnosed with metastasis of hepatocellular carcinoma in the semimembranosus muscle and treated by extensive resection. We report this case with a review of the relevant literature.