비선형 특징추출 기법에 의한 머리전달함수 ( HRTE ) 의 저차원 모델링 및 합성

서상원(Sang Won Suh),김기홍(Ki Hong Kim),김현석(Ki Hong Kim),김현빈(Hyun Suk Kim),이의택(Ee Taek Lee) 한국정보처리학회 2000 정보처리학회논문지 Vol.7 No.5

For the implementation of 3D Sound Localization system, the binaural filtering by HRTFs is generally employed. But the HRTF filter is of high order and its coefficients for all directions have to be stored, which imposes a rather large memory requirement. To cope with this, research works have centered on obtaining low dimensional HRTF representations without significant loss of information and synthesizing the original HRTF efficiently, by means of feature extraction methods for multivariate data including PCA. In these researches, conventional linear PCA was applied to the frequency domain HRTF data and using relatively small number of principal components the original HRTFs could be synthesized in approximation. In this paper we applied neural network based nonlinear PCA model (NLPCA) and the nonlinear PLS regression model (NLPLS) for this low dimensional HRTF modeling and analyze the results in comparison with the PCA. The NLPCA that performs projection of data onto the nonlinear surfaces showed the capability of more efficient HRTF feature extraction than linear PCA and the NLPLS regression model that incorporates the directional information in feature extraction yielded more stable results in synthesizing general HRTFs not included in the model training.

Trichophyton verrucosum에 의한 두부독창

김현석(Hyung Sug Kim),최종수(Jong Soo Choi),김기홍(Ki Hong Kim) 대한피부과학회 1989 대한피부과학회지 Vol.27 No.1

We report a case of kerion celsi caused by Trichophyton verrucosum in a 4-year-old male. He presented painful, tender, indurated, boggy masses discharing pus on the vertex and occiput. Kerion celsi caued by T. verrucosum was diagnosed by the characteristic gross and microscopic findings of the colony on the Sabourauds glucose. agar. The possible source of infection was searched and wq found that he raised the cattles in his house. They had multiple, scaly, whitish plaques on the skin and T. verrucosum was identified from the hairs of the lesions. He had been treated with griseofulvin and prednisolone, and all lesions were cleared leaving partial alopecia in 2 months.

뇌 악성 흑색종이 병발된 거대 선천성 색소성 모반

신동훈(Dong Hoon Shin),김현석(Hyun Suk Kim),최종수(Jong Soo Choi),김기홍(Ki Hong Kim),조수호(Soo Ho Jo) 대한피부과학회 1989 대한피부과학회지 Vol.27 No.6

We report a case of congenital giant pigmented nevus with malignant melanoma of brain in a 14-year-old male patient. He had giant pigmented nevus on the back and neck, and multiple satellite lesions over the whole body since birth. One year prior to visit to our hospital, the patient suffered from various neurologie symptoms including headache, nausea, vomiting, seizure and right side motor weakness. Flistologic findings of skin lesions were benign nevocytic nevi. Computed tomogram of brain demonstrated increased densities in the both fronto-parietal leptameninges and brain parenchyme. Histologic findings of brain parenchyme by stereotaxic long needle biopsy showed the infiltration of melanin containing atypical melanocytes. There was no evidence of malignant melanoma at other organs. All of these findings suggested that origin of malignant melanoma of brain parenchyme was leptomeninges rather than skin.

간섭계 레이더 고도계를 활용한 지형참조항법의 성능 분석

정승환(Seung-Hwan Jeong),윤주홍(Ju-Hong Yoon),박민규(Min-Gyu Park),김대영(Dae-Young Kim),성창기(Chang-Ki Sung),김현석(Hyun-Suk Kim),김윤형(Yoon-Hyung Kim),곽희준(Hee-Jun Kwak),선웅(Woong Sun),윤국진(Kuk-Jin Yoon) 한국항공우주학회 2012 韓國航空宇宙學會誌 Vol.40 No.4

본 논문에서는 간섭계 레이더 고도계를 활용한 지형참조항법의 성능을 분석하고자 한다. 간섭계 레이더 고도계는 항체의 주변 지형의 고도 중 가장 높은 값을 측정값으로 취함으로써 항법의 정확성을 향상시키고 있다. 이에 본 연구에서는 간섭계 레이더 고도계의 적용에 따른 새로운 측정 모델을 제시하고 이에 따른 지형참조항법 시스템을 구축하려 한다. 또한 필터에 따른 지형참조항법의 성능 분석을 위하여 확장형 칼만 필터, 무향 칼만 필터, 파티클 필터를 적용하며 여러 환경의 변화에 따른 지형참조항법의 성능을 도출고자 한다. The paper experimentally verifies the performance of Terrain-Aided Navigation (TAN) using an interferometric radio altimeter, which is recently used due to its accuracy. First, we propose a TAN system that utilizes an interferometric radio altimeter as a measurement system. Second, we implement extended Kalman filter, unscented Kalman filter, and particle filter to evaluate the performance of TAN according to the selection of filters and the difference of environments.

연하장애를 동반한 나반응 나 1례

김현석,황계영,문병천,최종수,김기홍,윤석근 大韓癩學會 1987 癩學 會誌 Vol.20 No.1

배양중 건선 각질형성세포의 증식과 분화양상

김기홍,신동훈,김현석,최종수,김성용,김미진,성언기 대한피부과학회 1999 大韓皮膚科學會誌 Vol.37 No.2

Background : Psoriasis is a common, scaly erythematous disease of unknown etiology, marked by remissions and exacerbations of unpredictable onset and duration. Among many etiologic factors, psoriatic keratinocyte is found to play the most important role. Objeetive : The purpose of this study is to evaluate the hypothesis that the mechanisms) responsible for the almormal proliferation of psoriatic keratinocytes may be located within the cell themselves. Methods : Human epidermal keratinocytes were isolated from lesion(PL) and from uninvolved skin (PN) with chronic plaque-like psoriasis and from the normal skin(NN). Keratinocytes were passaged onto culture vessels without the feeder layer and maintained with serum free medium. Growth rates were measured in secondary cultures by MTT assay and ultrastructural findings of cell differentiation were evaluated with a transmission electron microscope. Results : 1. Keratinocytes from PL reached 50%m confluency in one week compared to two weeks of PN and NN in primary cultures. 2. By the MTT assay, keratinocyte proliferation from PL showed a significantly faster rate than those from PN and NN(p$lt;0.01). But there was no significant difference of keratinocyte proliferation rate between PN and NN(p$gt;0.05). 3. All of the three cell populations(PL, PN, NN) showed variable degrees of cell differentiation during secondary culturing in a serum-free medium. In the PL, however, small, compact basal cells were more prevalent than PN and NN. 4. When keratinocytes underwent differentiation by culturing in DMEM with senun, keratinocytes from PL formed more cell layers with incomplete formation of cornified envelopes suggests the presence of some unknown factors that induce or promote psoriasis. While keratinacytes from PN and NN were characterized by a complete cornified layer as in normal skin. Conclusion : These results indicated that the characteristic hyperproliferation and the defective terminal differentiation of keratinocytes of PL were maintained throughout the culture period.

Kaposi 수두양 발진 3예

김기홍,김현석,최종수,황계영 영남대학교 의과대학 1987 Yeungnam University Journal of Medicine Vol.4 No.2

저자들은 기존피부질환으로 아토피 피부염을 가진 환자에서 발생한 herpes virus에 의한 것으로 추정되는 Kaposi 수두양 발진 3예를 경험하였고 acyclovir를 사용하여 현저한 치유효과를 보았다. Kaposi's varicelliform eruption is a more or less generalized infection of the skin, and sometimes of internal organs, with herpes simplex, vaccinia or Coxsackie virus A 16; it appears in people who have atopic dermatitis or some other skin diseases. There is a predilection for infants and children, but no age-group is exempt. We reported 3 cases of Kaposi's varicelliform eruption with atopic dermatitis. They had characteristic multiple umbilicated vesicles on the sites that atopic dermatitis had been involved. A 14-year-old boy and a 2-month-old infant had fever. A 17-year-old boy had wide-spread vesicles. All three patients showed multinucleated giant cells on Tzanck test, that suggests herpes simplex virus origin. They were treated with acyclovir. Within 1 to 2 days after the initiation of the therapy, new lesions had ceased to develop. Most of the lesions were cleared in 7 days without complication.

Guinea Pig에 유발시킨 Trichopyton Verrucosum감염증의 경과

김현석,최종수,김기홍 영남대학교 의과대학 1989 Yeungnam University Journal of Medicine Vol.6 No.1

T.verrucosum에 의한 피부사상균증의 임상 및 병리조직학적 경과를 이해하여 진단과 치료에 도움이 되고자, 환자와 그 감염원으로 추정되는 한우에서 채취한 T.verrucosum을 Sabouraud 포도당 한천배지에서의 성장속도를 비교하고, 기니픽에 접종한 후 다음과 같은 결과를 얻었다. Sabouraud포도당 한천배지에서의 성장속도는 한우주가 환자주에 비해 빨랐으며 25℃보다 37℃에서 더 빨리 자랐으나, 환자주는 온도에 따른 차이가 없었다. 홍반과 인설이 6일 경부터 증가하여 14-16일경에 황선과 유사한 병변을 형성하였으며 이후 점차 감소하여 30일 경에는 부분적인 탈모를 남기고 치유되었다. 환자주와 한우주에서 병변의 진행과정은 큰 차이가 없었으며 그 정도에서는 환자주에서 한우주보다 약간 더 심하게 나타났다. 병리조직학적인 변화는 접종 3일째에 극세포증과 혈관의 확장 및 증식이 나타나기 시작하여 12일 경에 최고에 도달했으며 이때에 과각화증, 이상각화증, 표피내 미세농양, 해면증과 더불어 진피의 혈관증식 및 확장, 세포침윤이 가장 심하였고 이러한 표피와 진피의 변화는 25일 경까지 지속된후 감소되어 33일째는 가벼운 과각화증과 극세포증을 보였으며 진피내에는 부분적으로 약간의 혈관 확장과 단핵구의 침윤을 나타내었다. PAS염색상 접종 6일에 균사가 각질층하부와 모낭개구부에서 보인 후 9일째는 외내측 모근초와 모간에서도 관찰되었으며 21일째는 완전히 소실되었다. Trichophytin 피부반응검사에서는 평균 9.83±1.17일에 24마리의 기니픽 모두에서 양성반응을 나타내었다. 이상의 결과로 미루어 볼 때 T.verrucosum에 의한 피부사상균증은 조기에 세포면역을 유도하여 특히 모낭에 심한 염증을 일으키며 병변의 빠른 치유와 연관이 있을 것으로 사료된다. T.verrucosum infection has been reported for the first time in 1986 in Korean and has been increasing progressively. To evaluate the progress of clinical and histopathological change of dermatophytosis caused by T.verrucosum, inoculation study, using T.verrucosum isolated from infected human(human strain) and from infected cattle(cattle strain), was done in 24 male albino Hartley guinea pig. Their clinical and histopathological changes were evaluated. In addition, comparison for the growth rate between human strain and cattle strain on Sabouraud's glucose agar was made. The results were as follows : 1. Growth rate on Sabouraud's glucose agar : Cattle strain showed significantly more rapid growth rate than human strain on Sabouraud's glucose rate at 25℃ and 37℃. And cattle strain showed more rapid growth rate at 37℃ than 25℃. But human strain showed no significant difference of growth rate at both temperature. 2. Clinical findings : Initial erythema, scale and crust were developed about 8th after inoculation. All three findings reached maximum severity about 12th to 16th day and disappeared about 30th to 34th day after inoculation. There was no significant difference in progress of erytheman, scale and crust between cattle strain and human strain. 3. Histopathological findings : Although mild acanthosis was noticed on the 3rd day after inoculation, the other findings including parakeratosis, intraepidermal abscess, spongiosis and vascular change, cellular infiltration were found on 9th day after inoculation. They reached maximum severity on the 12th day and lasted to the 25th day after inoculation. After that, all three findings were decreased gradually between 29th day and 33th day. On the PAS stainings, hyphae and spores were found on the 6th day and disappeared on the 21th day after inoculation. 4. In trichophytin skin test, all of the 24 guinea pigs became positive within average 9.83±1.17 days. These findings suggested that dermatophytosis caused by T.verrucosum induced rapid cell mediated immunity and contributed to rapid resolution of the lesion.

1997년 여름에 유행한 성인 장바이러스성 뇌막염

최휘철,송홍기,고임석,김형철,김현석,권기한,이병철 대한신경과학회 1998 대한신경과학회지 Vol.16 No.6