일관성 광대역 정합장처리에 의한 수중 이동음원의 위치추적

신기철,박재은,김재수 韓國海洋大學校 附設 海洋科學技術硏究所 2002 硏究論文集 Vol.11 No.2

최근 수중음향에 대한 관심은 천해와 같은 복잡한 음파의 상호작용과 경계조건이 부정확한 해양환경으로 이동하고 있다. 천해 음향전파에 의해서 발생하는 어려움을 극복하기 위한 방법으로 음원의 광대역 스펙트럼에서 얻어지는 정보를 사용하여 견고성과 신뢰성을 증가시키는 광대역 정합장처리 기법이 사용된다. 본 논문에서는 협대역에서의 음장의 공간 일관성을 확장하여 다중 주파수를 사용한 주파수-공간 일관성 광대역 프로세서를 제안하였고, 이 프로세서를 실제 광대역 이동음원에 적용하여 음원위치추적을 수행하였다. 제안된 일관성 프로세서는 음원의 정위치 추정확률이 높았으며, 특히 정합장출력의 부엽준위에서 비일관성 프로세서와 비교해 일관성 프로세서가 상당히 낮은 준위를 나타내었다. The shallow-water environment presents additional challenges arising from the complex interaction patterns of the sound with the sea bed. In order to overcome the difficulties generated by shallow-water propagation, broad-band matched field processing has been employed in an effort to increase robustness by utilizing multiple frequency information. In this paper, a coherent broad-band matched field processor is introduced that incorporates the spatial coherence of the acoustic field not only over one frequency but across frequencies. The incoherent and coherent processors are applied to the experimental data where it is shown that both processors give a high probability of correct localization. Also it is found that a coherent processor has better performance in the sidelobe pattern of ambiguity surfaces.

기하광학영역에서의 능동소나 표적신호합성

신기철,박재은,김재수,최상문,김우식 한국해양대학교 해양과학기술연구소 2001 硏究論文集 Vol.10 No.1

능동소나 시스템에서 표적신호의 근거리 정보가 중요해짐에 따라, 표적 음향산란 신호의 고유한특성을 분석하기 위해 실험적인 방법과 시뮬레이션 기법이 사용된다. 본 논문에서는 표적신호 합성을 위해 축소표적 반향실험을 수행하였고, 자료의 분석 결과 축소표적의 음향산란은 거울면 반사의 영향이 큰 것으로 분석되어, 표적신호 합성에서 기하광학이론을 응용하였다. 복잡한 형태의 표적을 여러 표본형상으로 분리하고, 각 표본형상의 기여도를 신호의 위상과 강도를 줌으로써 계산하였으며. 표적신호 합성모델의 검증을 위해 실제 축소표적 실험 결과와 비교하였다. 혁심용어: 기하광학이론. 음향산란, 거울면반사. 축소표적, 능동소나 투고분야: 수중음향 분야 (5.2) Since the near field iformation of target signal is important in the development and verification of active sonar system experimental method and simulation technique are widely used in order to analyze the detail characteristics of target scattered echoes. Therefore, in this paper, the scale target experiment is performed to develope and improve the target signal simulation model. Since the experimental results show that the specular reflection is the major component among scattering mechanisms, the target signal simulation model based on the Geometric Optics Theory (GOT) is developed. Complex target is separated into simple shapes, known as canonical shape. The contribution from individual canonical shapes are summed with proper phase and amplitude to produse the target strength of the whole complex body. Simulated target signal is compared with the experimental results fed discussed.

수중 축소표적의 음향산란에 관한 연구 -실험과 분석

신기철,김재수 韓國海洋大學校 附設 海洋科學技術硏究所 1999 硏究論文集 Vol.8 No.-

The target detection, classification and motion analyses by active sonar system requires the detailed characteristics of scattered echoes in the near field. Because of the inherently complex scattering mechanism, experimental methods are widely used to understand the process of scattered echo formation. In this paper, the experimental approach and the date processing techniques are applied to the analyses of scattering mechanism. For this purpose, the scale target experiment in acoustic water tank is designed and the date obtained in the experiment are analyzed to characterize the echoes in time and frequency domain. Expecially, the analysis is focused on the identification of location and directivity of each HL points for parameterization of HL. In the geometric region, acoustic scattering is dominated by the specular reflection due to the shapes of target, and re-radiation is also important in certain aspect angle of the target.

최소분산 프로세서를 사용한 정합장 처리에서 신호단편 수에 따른 바이어스의 영향

박재은,신기철,김재수 韓國海洋大學校 附設 海洋科學技術硏究所 2001 硏究論文集 Vol.10 No.2

적응 정합장처리에서 어레이의 센서 수보다 부족한 신호단편 수로 표본 공분산 행렬을 구성할 경우 행렬 계수의 부족으로 행렬의 역변환에 문제가 발생된다. 이를 해결하기 위해 표본 공분산행렬의 대각성분에 일정한 값을 더하거나 고유분해와 같은 기법을 사용하나, 그 결과로 프로세서 출력에서는 바이어스가 발생된다. 본 논문은 고정음원에서 신호단편의 수에 따른 적응 프로세서 출력의 바이어스와 음원 위치 추정결과를 고찰하기 위해 표본 공분산행렬의 대각성분에 일정한 값을 첨가하는 방법으로 최소분산 기법을 사용하여 수치실험과 실측 자료를 분석하였다. 그 결과 센서 수보다 많은 신호단편을 사용하는 것이 바이어스가 적으며, 음원 위치 추정에서도 좋은 성능을 보였다. When using a sample covariance matrix data in paucity of snapshots, adaptive matched field processing will have problem in inverting covariance matrix due to the rank deficiency. The general solutions are diagonal loading and eigenanalysis methods, but there is a significant bias in the power output. This paper presents a quantitative study of bias of power output and the performance of source localization through the simulation and the measured data analysis in fixed source case using the diagonal loading method for the minimum variance processor. Results show that the bias in power output is reduced and the performance of source localization is improved when the number of snapshots is greater than the number of array sensors.

관동맥 재개통 후 QTc간격분산의 감소 : 정량적으로 측정한 심근 허혈의 호전 정도와의 연관성 Relationships with the Quantitative Degree of Improvement in Myocardial Ischemia

박상선,최기준,남기병,이철환,홍멸기,박성욱,박승정,신중우,문대혁,김유호 대한순환기학회 2000 Korean Circulation Journal Vol.30 No.8

8.3% Carbamide Peroxide 함유 펜 형 자가미백제인 BIancTis Forte의 색조개선 및 안전성에 관한 임상연구

이진경,민선홍,홍성태,오소람,정신혜,황영혜,유성엽,배광식,백승호,이우철,손원준,금기연 대한치과보존학회 2009 Restorative Dentistry & Endodontics Vol.34 No.2

This clinical study evaluated the whitening effect and safety of polymer based-pen type BlancTis Forte(NIBEC) containing 8.3% carbamide peroxide. Twenty volunteers used the BlancTis Forte whitening agent for 2 hours twice a day for 4 weeks As a control. Whitening Effect Pen (LG) containing 3% hydrogen peroxide was used by 20 volunteers using the same protocol. The change in shade (ΔE^(*) color difference) was measured using Shadepilot™ (DeguDent) before, during and after bleaching (2 weeks, 4 weeks and postbleaching 4 weeks). A clinical examination for any side effects (tooth hypersensitivity or soft tissue complications) was also performed at each check-up. The following results were obtained. 1 Both the experimental and control groups displayed a noticeable change in shade (ΔE) of over 2 No significant differences were found between the two group (p>0.05) implying that the two agents have a similar whitening effect. 2 The whitening effect was mainly due to changes in a and b values rather than in L value (brightness). The experimental group showed a significantly higher change in b value thus yellow shade than the control(p < 0.05) 3 None of the participants complained of tooth hypersensitivity or soft tissue complications confirming the safety of both whitening agents 8.3%의 carbamide peroxide를 함유한 펜형 코팅용 미백제인 BlancTis Forte (NIBEC, Seosul & JinCheon)를 실험군으로, 3% hydrogen peroxide를 함유한글 Whitening Effect Pen (LG. Seoul) 제재를 대조군으로 각각 피험자 20명에게 2시간씩 1일 2회 제조사의 지시대로 치아표면에 4주간 적용하도록 지시하고 색조개선 효능과 안전성을 평가하였다. 미백 효과는 미백 전 및 미백 2주, 4주 및 미백 종료 4주 후에 Shadopilot™을 이용하여 색 변화를 측정하였고, 매 내원시기마다 모든 환자는 치수생활력 검사와 치주 및 치태 검사를 통해 부작용 여부 (치아과민증 및 구감 내 연조직의 부작용)를 기록한 후 다음과 같은 결과를 얻었다. 1.실험군 및 대조군의 색 변화량 (ΔE)은 2이상으로 인지할 수 있는 색 변화를 보였으며, 두 제품 간에는 통계적으로 유의한 차이를 보이지 않아 (p > 0.05) 유사한 미백효능을 나타냄을 알 수 있었다. 2,미백효과는 명도의 개선보다는 주로 a. b값의 변화에 의한 것으로 특히 실험군에서 b값의 변화, 즉 황색조의 개선효과가 대조군에 비해 유의성 있게 높은 것으로 나타났다 (p <0.05). 3.치아나 치은의 과민증이나 이상증상을 호소하는 피험자는 없어 두 제품 모두 안전성을 확인할 수 있었다.

The Use of Cultured Allogenic Keratinocyte Grafting in a Patient with Epidermolysis Bullosa Simplex

Kee Cheol Shin,Bo Young Park,김한구,Woo Seob Kim,배태희 대한피부과학회 2011 Annals of Dermatology Vol.23 No.-

Epidermolysis bullosa (EB) is a rare genetic disease that is known for continuous skin blistering caused by minor trauma. The skin blisters and bullae that develop often cause skin defects. There is no definitive treatment for EB, only symptomatic relief. We report our experience with cultured allogenic keratinocyte grafting in a newborn patient with EB simplex who had unhealed raw surfaces and was not a skin grafting candidate. The skin lesions of the patient were covered with cultured allogenic keratinocyte grafts and re-epithelialized quickly with no scarring. Allogenic keratinocyte grafting reduced pain and produced noticeable improvements in the unhealed wounds. We think that allogenic keratinocyte grafting can play an important role in the management of patients with EB simplex. (Ann Dermatol 23(S3) S393∼S397, 2011)

Case Reports : The Use of Cultured Allogenic Keratinocyte Grafting in a Patient with Epidermolysis Bullosa Simplex

( Kee Cheol Shin ),( Bo Young Park ),( Han Koo Kim ),( Woo Seob Kim ),( Tae Hui Bae ) 대한피부과학회 2011 Annals of Dermatology Vol.23 No.3s

Epidermolysis bullosa (EB) is a rare genetic disease that is known for continuous skin blistering caused by minor trauma. The skin blisters and bullae that develop often cause skin defects. There is no definitive treatment for EB, only symptomatic relief. We report our experience with cultured allogenic keratinocyte grafting in a newborn patient with EB simplex who had unhealed raw surfaces and was not a skin grafting candidate. The skin lesions of the patient were covered with cultured allogenic keratinocyte grafts and re-epithelialized quickly with no scarring. Allogenic keratinocyte grafting reduced pain and produced noticeable improvements in the unhealed wounds. We think that allogenic keratinocyte grafting can play an important role in the management of patients with EB simplex. (Ann Dermatol 23(S3) S393~S397, 2011)

Hot-Wall Evaporation Technique으로 성장된 CdS 박막의 광전도 셀 특성

신영진,정태수,신현길,김택성,정철훈,이훈,신영신,유기수 全北大學校 基礎科學硏究所 1994 基礎科學 Vol.16 No.-

Hot-wall evaporation technique으로 세라믹 기판 위에 CdS 박막을 성장하였다. 이 때 증발원과 기판의 온도는 각각 570, 400℃ 이고 두께는 3μm이었다. 공기 중에서 열처리하여 감도(γ), 광전류와 암전류의 비(pc/dc), 최대허용소비전력(MAPD), spectral response 및 응답시간 등을 측정하였다. 550℃, 30분간 열처리한 경우 가장 좋은 광전도 특성을 얻어으며 γ=0.89, pc/dc?10^4, MAPD: 492 mW, rise time이 100 ms, decay time이 260ms 이었다. The CdS thin films are grown on ceramic plate by hot-wall evaporation technique. The source and substrate temperature is 570 and 400℃, respectively, and the thickness of the film is 3μm. In order to explore the applicability as a photoconductive cell we measured the sensitivity(γ), the ratio of photocurrent to darkcurrent (pc/dc), maximum allowable power dissipation (MAPD), spectral response and response time. The results indicated that for the samples annealed at 550℃ in air atmosphere for 30 minutes the photoconductive characteristics are the best. Then we obtained the sensitivity of 0.89, the value of pc/dc of about 10^4, the MAPD of 492 mW and the rise and decay time of 100 ms and 260 ms, respectively.

Usefulness of Gold Thread Implantation for Crow's Feet

Shin, Kee-Cheol,Bae, Tae-Hui,Kim, Woo-Seob,Kim, Han-Koo Korean Society of Plastic and Reconstructive Surge 2012 Archives of Plastic Surgery Vol.39 No.1

Background : Conservative techniques designed to block or delay the aging process have been utilized in various ways for many years. However, their effects can be relatively minimal and short-term in most cases compared to surgery. The objective of this study was to evaluate the efficacy and safety of gold thread implantation for the treatment of periorbital wrinkles. Methods : A total of 78 consecutive patients who showed mild to severe periorbital wrinkles were deemed appropriate candidates, including 69 women and 9 men ranging from 31 to 59 years (mean, 47 years). Six gold threads about 4 cm in length were inserted subdermally in each patient at intervals of about 0.5 cm. Follow-up assessments were performed 1, 4, and 12 weeks after the procedure. The efficacy was rated by the physician using the Wrinkle Severity Rating Scale and patients who made global assessments of changes in periorbital wrinkles using the Visual Analog Scale. Adverse events were monitored throughout the course of the study. Results : The patients showed significant improvements after the procedure. There were minor complications such as foreign body sensation in the eye (2.63%) and eye pain (1.32%) that improved spontaneously without any specific treatments. Conclusions : Subdermal implantation of gold thread improves the appearance of periorbital wrinkles and does not appear to have serious side effects. Insertion of gold thread may be an effective and safe method for facial rejuvenation.