수질 모니터링을 위한 유해 물질 유입에 따른 생물체의 행동 반응 분석 및 인식

김철기,차의영,Kim, Cheol-Ki,Cha, Eui-Young 한국정보처리학회 2002 정보처리학회논문지B Vol.9 No.5

본 논문에서는 자동 추적 시스템을 이용하여 카바메이트 계열의 농약인 카보퓨란의 치명적인 투여에 대하여 반자연적인 조건에서 반응하는 깔따구의 움직임을 관찰하였다. 4령기에 있는 깔따구를 $6cm\times{7cm}\times{2.5cm}$ 크기의 서식 장소와 $18^\circ{C}$의 수온, 명기와 암기를 각각 10시간, 14시간의 조건에서 관찰을 하였다. 추적 시스템은 깔따구 몸체의 부분 점들을 탐지하여 추적하도록 하였다. 모든 실험은 반자연적인(semi-natural) 상태에서 진행되었으며 약제 카보퓨란(Carbofuran 0.1mg/l) 처리 전 후 이틀씩 모두 4일에 걸쳐서 연속적으로 진행되었다. 실험 결과 약제의 처리후에 압축된 지그제그 형태로 나타나는 "떨림 현상"과 같은 비정규적인 행동들이 종종 나타남을 알 수 있었다. 약제 처리된 종들의 행동 변화를 탐지하기 위하여, 웨이블릿 분석이 다른 움직임 패턴들을 특징화하기 위하여 사용되었다. 이산 웨이블릿에 기반하여 추출된 파라미터들은 약제처리 전후의 움직임에 대한 다른 유형의 패턴들을 표현하기 위하여 인공 신경망을 통하여 학습되었다. 이러한 웨이블릿과 인공 신경망의 통합 모델은 특징화된 움직임 패턴들의 발생 시점을 탐지할 수 있었으며, 수질 모니터링을 위한 독성 물질의 유입을 자동으로 탐지할 수 있는 도구로써 사용될 수 있음을 알 수 있었다.을 알 수 있었다. In this paper, Using an automatic tracking system, behavior of an aquatic insect, Chironomus sp. (Chironomidae), was observed in semi-natural conditions in response to sub-lethal treament of a carbamate insecticide, carbofuran. The fourth instar larvae were placed in an observation cage $(6cm\times{7cm}\times{2.5cm)}$ at temperature of $18^\circ{C}$ and the light condition of 10 time (light) : 14 time (dark). The tracking system was devised to detect the instant, partial movement of the insect body. Individual movement was traced after the treatment of carbofuran (0.1ppm) for four days 2days : before treatment, 2 days : after treatment). Along with the other irregular behaviors, "ventilation activity", appearing as a shape of "compressed zig-zag", was more frequently observed after the treatment of the insecticide. The activity of the test individuals was also generally depressed after the chemical treatment. In order to detect behavioral changes of the treated specimens, wavelet analysis was implemented to characterize different movement patterns. The extracted parameters based on Discrete Wavelet Transforms (DWT) were subsequently provided to artificial neural networks to be trained to represent different patterns of the movement tracks before and after treatments of the insecticide. This combined model of wavelets and artificial neural networks was able to point out the occurrence of characteristic movement patterns, and could be an alternative tool for automatically detecting presences of toxic chemicals for water quality monitoring. quality monitoring.

Additive Regression Models for Censored Data

김철기,Kim, Chul-Ki The Korean Society for Quality Management 1996 품질경영학회지 Vol.24 No.1

In this paper we develop nonparametric methods for regression analysis when the response variable is subject to censoring that arises naturally in quality engineering. This development is based on a general missing information principle that enables us to apply, via an iterative scheme, nonparametric regression techniques for complete data to iteratively reconstructed data from a given sample with censored observations. In particular, additive regression models are extended to right-censored data. This nonparametric regression method is applied to a simulated data set and the estimated smooth functions provide insights into the relationship between failure time and explanatory variables in the data.

비선형 분석에 의한 뇌파 아티펙트 검출 알고리즘

김철기,박준모,김남호,Kim, Chul-Ki,Park, Jun-Mo,Kim, Nam-Ho 한국융합신호처리학회 2020 융합신호처리학회 논문지 (JISPS) Vol.21 No.1

수술 중 마취 깊이를 측정하는 방법으로 뇌파를 이용한 다양한 파라미터들이 사용되고 있으며, 실제 임상에서는 선형분석 기법 중 하나인 SEF가 널리 사용되고 있다. 그러나 최근 EEG를 포함한 생체학적 신호는 비선형 성질을 가지고 있다는 연구결과가 발표되면서, 이를 기반으로 한 파라미터 개발이 이뤄지고 있다. 본 연구에서는 보다 정확한 EEG 측정과 분석을 위해 비선형 분석 기법 기반의 파라미터를 개발과 이에 대한 정현파 분석을 통한 데이터와의 비교 분석을 통해 수술 중 전자장비와 EEG 계측 시 혼입될 수 있는 노이즈를 추출하고자 한다. Various parameters are used to measure anesthetic depth during surgery using brain waves, and in actual clinical use, the linear analysis SEF is widely used. However, with recent studies showing that biological signals including EEG, contain nonlinear properties interest in nonlinear analysis of brain signals is increasing and parameters based on these are being developed. In this study, we are going to develop a parameter that can measure EEG using the nonlinear analysis method and extract noise that can be mixed with external electronic equipment and EEG instrumentation by comparing it with the data from the bispectrum analysis of static waves.

구조용 직교 집성판의 면내전단계수 측정방법

김지용 ( Ji-yong Kim ),임형석 ( Hyungsuk Lim ),안경선 ( Kyung-sun Ahn ),방성준 ( Sung-jun Pang ),김민정 ( Min-jeong Kim ),심국보 ( Kugbo Shim ),김건호 ( Keon-ho Kim ),김철기 ( Chul-ki Kim ),오정권 ( Jung-kwon Oh ) 한국목재공학회 2021 한국목재공학회 학술발표논문집 Vol.2021 No.2

With increasing demands for high-rise timber buildings, Cross Laminated Timber (CLT) is widely used for various structural elements. Due to the complexity in structure, tall timber buildings are extremely difficult to design by hand. Therefore, computer-based structural design is required, and in-plane shear modulus for CLT is necessary as an input. However, any test standards are not providing even method for measurement of in-plane shear modulus on CLT or other massive wood panels. In this study, a method using picture frame is proposed for measuring in-plane shear modulus. A 20mm thick acrylic sheet was also tested to determine the range of pure shear, using digital image correlation (DIC) technique. Prior to CLT test, load is transferred to the acrylic panel through dowels. Displacements were measured in both directions (active and passive), and both sides (front and back). With measured displacements and loads, in-plane shear modulus was calculated. It was found that the picture frame test method is appropriate for the stiff massive wood panel.

구조용 직교 집성판의 면내전단계수 표준측정방법 도출

김지용 ( Ji-yong Kim ),안경선 ( Kyung-sun Ahn ),김민정 ( Min-jeong Kim ),오재원 ( Jaewon Oh ),방성준 ( Sung-jun Pang ),김건호 ( Keon-ho Kim ),김철기 ( Chul-ki Kim ),심국보 ( Kugbo Shim ),오정권 ( Jung-kwon Oh ) 한국목재공학회 2022 한국목재공학회 학술발표논문집 Vol.2022 No.1

With increasing demands for high-rise timber buildings, Cross Laminated Timber (CLT) is widely used for various structural elements. Due to the complexity in structure, tall timber buildings are extremely difficult to design by hand. Therefore, computer-based structural design is required, and in-plane shear modulus for CLT is necessary as an input. However, test standards or methods for measurement of the in-plane shear modulus of CLT are currently not provided or insufficient. In this study, a method using picture frame is proposed for measuring in-plane shear modulus, since picture frame could transfer crosshead load into the pure shear stress of the specimen. In this research, acrylic sheet, plywood panel and CLT panel were used as test specimens. Load was transferred from the universal testing machine(Instron) to the acrylic sheet and plywood via dowels, CLT via lag screws because of the thickness of the CLT panel. The acrylic sheet, which is an isotropic material, was tested to determine the measuring area and verify pure shear state occurred by the picture frame. Displacements were measured in both directions (active and passive), and both sides (front and back). In-plane shear modulus of acrylic sheet was evaluated with measured displacements and loads to compare with the literature values. The plywood panel was tested to determine the test protocol, and two stage load cycle test protocol was suggested. CLT panel was tested according to the determined measuring area and test protocol. Evaluated in-plane shear modulus of CLT was 693 MPa and it was found that the picture frame test method is appropriate for the stiff massive wood panel.

Measurement of Temperature Variation on PHE sensor with Applied Currents using Infrared Thermal Microscope

김기석(G. S. Kim),브라잘알 신하(B. Sihha),유영재(Y.-J. Eu),유윤규(Y. K. Yoo),김건우(K.W. Kim),김동표(D.-P. Kim),김건희(G. H. Kim),김철기(C.G. Kim) 한국정밀공학회 2012 한국정밀공학회 학술발표대회 논문집 Vol.2012 No.5월

多發性 原發性 惡性腫瘍

金哲基(C. K. Kim),張鍾院(Jong W. Chang) 대한외과학회 1970 Annals of Surgical Treatment and Research Vol.12 No.1

디지털콘텐츠 저작권보호 도구로써의 디지털 워터마킹 성능 비교

김철기 ( Kim Cheol Ki ) 한국디자인트렌드학회 2009 한국디자인포럼 Vol.24 No.-

디지털 기술의 발전과 더불어 창작물에 대한 소유권 정보의 중요성이 강조되고 있다. 특히 디지털 콘텐츠의 복제와 변경의 용이성으로 소유권 보호를 위한 다양한 별도의 방법이 필요한 시점이다. 이러한 문제점의 해결을 위하여 워터마킹기법의 경우 특히 영상에 대한 소유권 분쟁의 해법으로 근래에 각광을 받고 있는 기술들 중 하나이다. 그러나 아직까지 이러한 워터마킹기법 및 활용에 대한 이해가 부족한 실정이다. 본 논문에서는 2D 이미지 창작물에 대한 워터마킹 기법의 올바른 선택 기준을 위하여 JPEG 압축 기술인 DCT에 기반한 방법과 JPEG2000 압축 기술인 DWT에 기반한 방법의 성능 결과를 비교하고자 한다. 이를 위하여 100장의 사진, 애니메이션, 그래픽 등 다양한 장르의 이미지에 대하여 일반적으로 이루어질 수 있는 인위적 공격을 가하여 실험을 수행하였으며, 공격 후 삽입된 워터마크의 검출 여부와 워터마크 삽입 전후의 화질 변화도를 측정하였다. 본 논문의 최종적인 목적은 실험 결과에 기반하여 디자인 관련 창작작업에 있어 저작권 문제를 해결하는데 기준을 제공하는데 있다. The importance of copyright about visual creation as a new technology in the area of visual design and image archiving is emphasizing rapidly. Especially, due to the characteristics of easy duplication and modification of digital contents such as visual design, it is necessary to develop a variety of techniques for various protection purposes such as ownership claiming and authentication. To solve above problems, the watermarking technique is one of the most concerned techniques and is solution about image ownership. But comprehension of watermarking and application is insufficient so far. In this paper, to propose a good criterion of watermarking about 2D image creation, we will compare with DCT based method and DWT based method(the DCT is used for JPEG compression, the DWT is used for JPEG2000 compression). For performance tests, we used one hundred images from several jenre such as photography, animation, graphic, and measured watermarking extraction after some attacks. And we measured image quality before and after watermark insertion. This paper aims to support base for copyright troubles in design related creation works.

多發性 原發性 惡性腫瘍

金哲基(Chull, K. Kim) 대한외과학회 1975 Annals of Surgical Treatment and Research Vol.17 No.4

양성자 자기회전비율 측정에 관한 연구

김철기(C.G. Kim),우병칠(B.C. Woo),유권상(K.S. Ryu),박포규(P.C. Park),김창석(C.S. Kim) 한국자기학회 1991 한국자기학회 학술연구발표회 논문개요집 Vol.1 No.2