Microscopic Optical Beam Profile Measurement Technique for Near-Infrared Light by Using a Scanning Thermal Probe

Kim Hyuntae,Choi Soobong,Park Woongkyu,Cho Sangjoon,Kim Cheolsu 한국물리학회 2020 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.77 No.10

In this paper, we report that the beam profile of the near-infrared light from superluminescent diodes (SLDs) can be measured with a resolution below the diffraction limit by using the photothermal effect and scanning thermal microscopy (SThM). Due to the sub-diffraction resolution of SThM, the beam profile measured using SThM was much clearer than the beam profile obtained by using the knife-edge method. By stacking cross-sectional images of the optical beam profile obtained by using SThM, we were able to obtain successively the three-dimensional optical beam profile. Our novel method of using small probes to measure optical beam profiles is compatible with conventional microscopy systems and can potentially be used in various applications.

절단검색을 지원하는 전자사전 구조

김철수(Cheolsu kim) 한국정보과학회 2003 정보과학회 컴퓨팅의 실제 논문지 Vol.9 No.1

역화일을 파일구조로 이용하는 정보 검색 시스템에서는 검색자가 검색할 분야의 완전 단어를 알고 있어야 검색이 가능하다. 그러나 검색자가 완전 단어가 아닌 단어의 부분 문자열을 알고 있는 경우가 많다. 이럴 경우 부분 문자열을 포함하는 색인어들을 검색할 수 있다면 관련 문서들을 검색할 수 있다.또한 검색된 문헌 수가 너무 적을 경우 부분 문자열을 포함하는 단어를 색인어로 가지는 모든 문서들을 검색하기 위한 방법이 필요하다. 이런 요건들을 충족시키기 위해서는 사용자는 용어 절단 방법을 이용하여 질의어를 구성할 수 있어야 하고, 검색 시스템은 절단 검색을 지원할 수 있는 전자 사전이 필요하다. 본 논문에서는 절단검색을 효율적으로 지원할 수 있는 전자 사전 구조를 설계하고 구현한다. 이 전자 사전은 저장된 단어 수에 관계없이 주어진 한 개의 단어 검색 시간 및 역 문자열로 구성된 단어 검색 시간이 빠르고 일정하다. 절단검색을 효율적으로 지원하기 위하여 트라이 구조를 이용하였으며, 빠른 검색 시간을 지원하기 위해 배열을 이용한 방법을 사용하였다. 절단된 용어의 검색 과정에서 확장할 문자열의 길이를 최소화하여 검색 시간을 줄였다. In an Information Retrieval System(IRS) based on an inverted file as a file structure it is possible to retrieve related documents when the searcher know the complete words of searching fields.However, there are many cases in which the searcher may not know the complete words but a partial string of words with which to search.In this case, if the searcher can search indexes that include the known partial string, it is possible to retrieve related documents. Futhermore, when the retrieved documents are few, we need a method to find all documents having indexes which include known the partial string. To satisfy these requests, the searcher should be able to construct a query formulation that uses the term truncation method. Also the IRS should have an electronic dictionary that can support a truncated search term. This paper designs and implements an electronic dictionary(ED) structure to support a truncation search efficiently. The ED guarantees very fast and constant searching time for searching a term entry and the inversely alphabetized entry of it, regardless of the number of inserted words.In order to support a truncation search efficiently, we use the Trie structure and in order to accommodate fast searching time we use a method using array.In the searching process of a truncated term, we can reduce the searching time by minimizing the length of string to be expanded.

탄력적인 환경 지원을 위한 실시간 프로토타이핑 도구

김철수(Cheolsu Kim),하란(Rhan Ha) 한국정보과학회 1997 한국정보과학회 학술발표논문집 Vol.24 No.2Ⅳ

실세계의 보다 많은 인프라구조들이 광범위하게 실시간 컴퓨팅 기술에 의존하게됨에 따라 실시간 시스템들은 각기 다른 특성을 갖는 시간 제한 요건을 갖게 되었으며 이에 따라 주기적 태스크 모델에 기반을 두고 개발된 기존의 대다수 실시간 프로토타이핑 도구는 복합적 좝 모델, 비정확적 계산 모델 등에 포함되는 실시간 태스크를 처리할 수 있도록 도구의 확장 및 다른 태스크 모델들의 통합을 요구하게 되었다. 본 논문에서는 시스템이 예측성을 획득할 수 있도록 임의의 릴리즈 시간과 동적인 실행 시간을 갖는 좝이 거리 제한 요건과 간격 제한 요건을 갖는 복합적 좝 모델로 확장된 구조에서 최악의 경우 수행 완료 시간의 바운드를 계산하였으며, 이러한 특성을 갖는 좝의 처리를 위해 기존의 실시간 프르토타이핑 도구를 확장하였다.

랜덤 위상 마스크와 2-단계 위상 천이 디지털 홀로그래피를 이용한 이진 영상 이중 암호화

김철수(Cheolsu Kim) 한국멀티미디어학회 2016 멀티미디어학회논문지 Vol.19 No.6

지역(국가) 간 색상에 대한 인지 및 감성의 차에 대한 연구

김철수(Kim CheolSu),정도성(Chung DoSung),박영목(Park YeongMog),민규홍(Min KyuHong),김관배(Kim KwanBae) 한국디자인학회 1999 디자인학연구 Vol.- No.29

위치이동에 무관한 웨이블릿 변환을 이용한 패턴인식

김국진(Kukjin Kim),조성원(Seongwon Cho),김재민(Jaemin Kim),임철수(Cheolsu Lim) 한국지능시스템학회 2003 한국지능시스템학회논문지 Vol.13 No.3

웨이블릿 변환(Wavelet Transform)은 공간-주파수 영역에서 신호의 국소특성을 효율적으로 구현할 수 있다. 하지만, 웨이블릿 변환을 패턴 인식을 위한 특징 추출에 적용할 경우, 입력 신호의 위치 이동에 따라 추출된 특징 값이 변화하게 되어 인식률이 낮아지는 결함이 있다. 본 논문에서는 웨이블릿 변환을 패턴 인식에 적용할 경우 발생하는 입력 신호의 위치 이동에 따른 문제점을 보완하여 노이즈에 강인한 홍채인식 알고리즘을 제안한다. 실험을 통하여 제안한 알고리즘의 우수성을 보여준다. Wavelet Transform can effectively represent the local characteristics of a signal in the space-frequency domain. However, the feature vector extracted using wavelet transform is not translation invariant. This paper describes a new feature extraction method using wavelet transform, which is translation-invariant. Based on this translation-invariant feature extraction, the iris recognition method, based on this feature extraction method, is robust to noises. Experimentally, we show that the proposed method produces super performance in iris recognition.

Carbenoxolone and triterpenoids inhibited mucin secretion from airway epithelial cells

Heo, Ho Jin,Kim, Cheolsu,Lee, Hyun Jae,Kim, Young Sik,Kang, Sam Sik,Seo, Un Kyo,Kim, Yun Hee,Park, Yang Chun,Seok, Jeong Ho,Lee, Choong Jae Heyden & Son 2007 Phytotherapy research Vol.21 No.5

<P>This study investigated whether carbenoxolone, oleanolic acid and ursolic acid affect ATP-induced mucin secretion from cultured airway epithelial cells. Confluent primary hamster tracheal surface epithelial (HTSE) cells were metabolically radiolabeled using <SUP>3</SUP>H-glucosamine for 24 h and chased for 30 min in the presence of varying concentrations of each agent to assess the effects on <SUP>3</SUP>H-mucin secretion. The possible cytotoxicity of each agent was investigated with a lactate dehydrogenase assay. The results were as follows: (1) carbenoxolone, oleanolic acid and ursolic acid significantly inhibited the secretion of airway mucin induced by ATP; (2) none of the compounds showed significant cytotoxicity at any concentration. This result suggests that carbenoxolone, oleanolic acid and ursolic acid can regulate ‘mucin secretion induced by ATP’ – a phenomenon simulating mucus overproduction from inflamed airway epithelial cells – by directly acting on airway mucin-secreting cells. Copyright © 2007 John Wiley & Sons, Ltd.</P>

Inhibition of Adenosine Triphosphate-stimulated Mucin Secretion from Airway Epithelial Cells by Schizandrin

Ho Jin Heo,Hyun Jae Lee,Cheolsu Kim,Ki Hwan Bae,Young Sik Kim,Sam Sik Kang,Yang Chun Park,Yun Hee Kim,Un Kyo Seo,Jeong Ho Seok,Choong Jae Lee 대한생리학회-대한약리학회 2006 The Korean Journal of Physiology & Pharmacology Vol.10 No.5

Schizandrae Fructus has been used for controlling respiratory allergic or inflammatory diseases in folk medicine and their components, schizandrin, schizandrin-A and gomisin-A were reported to have diverse biological effects. In this study, we investigated whether schizandrin, schizandrin-A and gomisin-A affect adenosine triphosphate (ATP)-induced mucin secretion from cultured airway epithelial cells. Confluent primary hamster tracheal surface epithelial (HTSE) cells were metabolically radiolabeled using <SUP>3</SUP>H-glucosamine for 24 h and chased for 30 min in the presence of varying concentrations of each agent to assess the effects on <SUP>3</SUP>H-mucin secretion. The results were as follows: 1) schizandrin significantly inhibited ATP-induced mucin secretion; 2) However, schizandrin-A and gomisin-A did not affect ATP-induced mucin secretion, significantly. We conclude that schizandrin can inhibit ATP- induced mucin secretion by directly acting on airway mucin-secreting cells. Therefore, schizandrin should further be investigated for the possible use as mucoregulators in the treatment of inflammatory airway diseases.

Glycyrrhizin and Morroniside Stimulate Mucin Secretion from Cultured Airway Epithelial Cells

Ho Jin Heo,Hyun Jae Lee,Cheolsu Kim,Kun Ho Son,Young Choong Kim,Young Sik Kim,Sam Sik Kang,Yang Chun Park,Yun Hee Kim,Un Kyo Seo,Jeong Ho Seok,Choong Jae Lee 대한생리학회-대한약리학회 2006 The Korean Journal of Physiology & Pharmacology Vol.10 No.6

In this study, we investigated whether glycyrrhizin, prunetin and morroniside affect mucin secretion from cultured airway epithelial cells and compared the possible activities of these agents with the inhibitory action on mucin secretion by poly-L-lysine (PLL) and the stimulatory action by adenosine triphosphate (ATP). Confluent primary hamster tracheal surface epithelial (HTSE) cells were metabolically radiolabeled using <SUP>3</SUP>H-glucosamine for 24 h and chased for 30 min in the presence of varying concentrations of each agent to assess the effects on <SUP>3</SUP>H-mucin secretion. The results were as follows: 1) glycyrrhizin and morroniside increased basal mucin secretion from airway; 2) prunetin did not affect basal mucin secretion; 3) glycyrrhizin did not inhibit ATP-induced mucin secretion. We conclude that glycyrrhizin and morroniside can increase basal mucin secretion, by directly acting on airway mucin-secreting cells and suggest that two compounds be further investigated for the possible use as mild expectorants during the treatment of inflammatory airway diseases.

홀로그래픽 광메모리 시스템을 이용한 3차원 영상 표현에 대한 연구

김철수 경주대학교 1999 論文集 Vol.11 No.-

In this paper, it is a demonstrated representing three dimensional image with imaging hologram and electric hologram. And it is proposed that an holographic optical memory system for representing three dimensional image in real time. In this system. BaTiO_3 crystal is used for recording material, because of its real time processing property, and reference wave is controlled by angular multiplexing method. In the angular multiplexing method, the incident angle of the reference beam is controlled by using BPH(binary phase hologram). which is designed and optimized with SA(simulated annealing) algorithm and represented on LCTV(liquid crystal television) for real-time processing. So, I expect the proposed system to use in realizing three dimensional TV broadcasting in the future.