팩시밀리 통신을 위한 JBIG 부호화 방식 ( A JBIG Coding Scheme to Facsimile Communication Application )

지창우,김용석,이종수,박성한 대한전자공학회 1994 대한전자공학회 워크샵 Vol.1994 No.-

수위 변동에 따른 호소의 연안대와 심저대의 저서성대형무척추동물 군집 변화 분석

지창우,유태식,이선호,박영석,곽인실 한국하천호수학회 2022 생태와 환경 Vol.55 No.3

The macroinvertebrate community in the Singal reservoir, Yedang and Juam lake was investigated three times from April 2021 to October 2021. Each lake was investigated by dividing it into inflow, middleflow, and outflow. Additionally, sampling was conducted again by dividing it into the edge and center parts at each inflow, middle-flow, and outflow. Eight families of benthic macroinvertebrates were collected except for chironomids in the sampling sites. Dominant macroinvertebrates were investigated as chironomids, and Tubificidae was sub-dominant organisms. The density of macroinvertebrate community was higher in the edge area than in the center bottom of the lakes. The density of chironomids was low when the water level was high but was high when the water level was low. In the edge area of the middle-flow in Singal reservoir, the density of chironomids was 1,208 ind. m-2 in April when the water level was high, but it increased to 1,401 ind. m-2 in July when the water level was low. Similarly, the density of chironomids at the outflow of Yedang lake was high (1,990 ind. m-2 ) in July when the water level was low. The density of chironomids also decreased along with the increasing water level at all edge areas of Juam lake. These results indicated that it will be necessary to consider the water level when studying macroinvertebrate communities in the lake.

대화형 멀티미디어 서비스를 위한 ATM 기반 VoD 시스템 ( VoD System based on ATM for Interactive Multimedia Services )

지창우,이형수,유준재,조병학 대한전자공학회 1997 대한전자공학회 학술대회 Vol.1997 No.01

강화된 최소 평균 제곱 학습법을 사용한 양방향 연상 메모리에 관한 연구 ( A Study on The Bidirectional Associative Memory Using Reinforced Least Mean Square Learning )

지창우,조유섭,김덕령,박성한 대한전자공학회 1991 대한전자공학회 학술대회 Vol.1991 No.1

G4 팩시밀리 응용을 위한 JBIG 코딩기술의 개선 ( Enhancement of the JBIG Coding Scheme for G4 FAX Application )

지창우,김덕령,안창범,김용석,박성한,이종수 대한전자공학회 1992 대한전자공학회 학술대회 Vol.1992 No.7

무손실 의료 영상 압축을 위한 적응적 심볼 교환에 기반을 둔 이진 적응 산술 부호화 방법

지창우,박성한 한국통신학회 1997 韓國通信學會論文誌 Vol.22 No.12

본 논문은 디지탈 의료 영상을 효과적으로 무손실 압축하기 위한 적용적 심볼 교환에 기반을 둔 새로운 부호화 방법을 제안한다. 제안하는 알고리즘은 먼저 원영상에 차분 규칙 또는 적용 예측기를 적용하여 차분 영상값을 구하며, 이러한 차분 영상값에 대한 개별 context를 결정한다. 다음 단계에서 context하에서 현재 부호화될 차분 영상값과 모델 템플리트상의 차분 영상값들 사이의 극성 일치를 갖는 심볼의 추정을 기반으로 한 적응적인 심볼 교환 과정을 적용하여 예측 심볼을 얻는다. 예측 심볼은 부호화 될 차분 영상값에 대해 가장 빈번하게 발생하리라고 예측되는 심볼을 가리키며, 예측 심볼이 차분 영상값과 동일할 때 부호화 효율이 높게 유지된다. 마지막 부호화 단계에서 이진 적응 산술 부호기는 특정 context가 주어진 차분 영상값의 예측 여부를 판단하는 이진 판단 트리를 사용하여 차분 영상값을 부호화 한다. 차분 영상값 예측 적중율 향상을 통하여 제안된 알고리즘의 부호화 효율은 ISO JPEG 무손실 예측기를 산술 부호기에 적용한 경우보다 약 33% 정도 높아지고, 차분 예측기 또는 적용 예측기를 산술 부호기에 적용한 경우에 비해 약 23% 정도 높아짐을 알 수 있다. 제안된 부호화 방법은 단위 구간 부분할시 곱셈 연산이 아닌 덧셈 연산을 사용하기 때문에 부호기의 복잡성이 낮고 다중 비트 공간의 영상을 이진 공간 열로 분할하지 않고 바로 다중 비트 의료 영상을 부호기에 적용 할 수 있기 때문에 의료 PACS의 영상 압축부에서 사용될 수 있다. In this paper, adaptive symbol changes-based medical image compression method is presented. First, the differenctial image domain is obtained using the differentiation rules or obaptive predictors applied to original mdeical image. Also, the algorithm determines the context associated with the differential image from the domain. Then prediction symbols which are thought tobe the most probable differential image values are maintained at a high value through the adaptive symbol changes procedure based on estimates of the symbols with polarity coincidence between the differential image values to be coded under to context and differential image values in the model template. At the coding step, the differential image values are encoded as "predicted" or "non-predicted" by the binary adaptive arithmetic encoder, where a binary decision tree is employed. The simlation results indicate that the prediction hit ratios of differential image values using the proposed algorithm improve the coding gain by 25% and 23% than arithmetic coder with ISO JPEG lossless predictor and arithmetic coder with differentiation rules or adaptive predictors, respectively. It can be used in compression part of medical PACS because the proposed method allows the encoder be directly applied to the full bit-planes medical image without a decomposition of the full bit-plane into a series of binary bit-planes as well as lower complexity of encoder through using an additions when sub-dividing recursively unit intervals.

팩시밀리 통신을 위한 JBIG 부호화방식 ( JBIG Coding Scheme to Facsimile Communication Application )

지창우,김용석,이종수,박성한 한국통신학회 1994 한국통신학회 워크샵 Vol.- No.-

Computational Analysis of Movement Behaviors of Medaka (Oryzias latipes) in Response to Chemical and Thermal Stressors

지창우,전태수,박영석,김흥수 한국물리학회 2012 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.60 No.4

Response behaviors of medaka (Oryzias latipes) were computationally analyzed after exposure to a temperature increase and toxic treatments. The temperature was increased from 25 C to 35 C while individual organisms of medaka were treated with copper at a low concentration (1.0mg/L). Movement tracks were continuously recorded for 6 hours before and for 6 hours after the treatments. Parameters (e.g., speed and stop number) and entropy values (e.g., Shannon entropy and R´eyni entropy) characterizing the movement tracks were calculated before and after the treatments. After the temperature increase, parameters and entropy values remained in the same range. Test organisms appeared to adapt to a gradual temperature increase to maintain the same behavioral state. After the treatments with copper, however, parameters such as speed, acceleration and stop number substantially decreased while the turning rate increased. Entropy values such as Shannon and R´eyni entropies were lower while Simpson index was higher after the chemical treatments. Complexity residing in the movement tracks appeared to decrease after the treatment with a chemical. According to the self-organizing map results, entropy values were associated with speed and acceleration. The parameter (speed) and the entropy value (Shannon entropy) changed in different time periods after the chemical treatment. The periodicity in entropy was not different between the early and the late periods after the treatments according to fast Fourier transform. The feasibility of computational monitoring and the structure property in the behavioral data were further discussed regarding ecological assessment of environmental stressors.

비메트릭 다변량 척도법과 네트워크 분석을 통한 멸종위기 국내 담수어류 20종의 먹이원 분석

지창우,이대성,이다영,박영석,곽인실 한국하천호수학회 2021 생태와 환경 Vol.54 No.2

By reviewing previous literature, we analyzed the food sources of 20 out of 29 endangered fish species from freshwater ecosystems in South Korea. A total of 19 studies reported that food sources of 20 endangered fish species included 20 phyla, 31 classes, 58 orders, 116 families, and 154 genera. Arthropod, insecta, diptera, and chironomidae were the most fed animal food sources according to different resolution of taxa index on phylum, class, order and family. Similarity, bacillariophyta, bacillariophyceae, naviculales, and cymbellaceae were the most fed abundant plant sources. A larger number of fish species were reliant on animal food sources than plant food sources. 18 of the endangered fish preyed on arthropods, whereas only 6 species consumed bacillariophyta. To characterize the feeding groups of the 20 fish species, a hierarchical clustering analysis and non-metric multidimensional scaling analysis were conducted. The fish species were divided into two groups: 1) insectivores and 2) planktivores. A network analysis, which associated the link between endangered fishes and food sources, also revealed the same two groups. The highest hub score of food sources was for macroinvertebrates, including diptera (0.47), ephemeroptera (0.42), and trichoptera (0.38), based on the network analysis. Niche breadth was used to calculate the diversity of the food sources. Phoxinus phoxinus (0.57) showed thehighest food source diversity among the fish species, whereas Iksookimia pacifica (0.01) showed the lowest. This study will be utilized for the conservation and restoration of the endangered fish species.

국내 담수어류 45종의 먹이원 분석(문헌자료 분석을 중심으로)

지창우,이대성,이다영,곽인실,박영석,Ji, Chang Woo,Lee, Dae-Seong,Lee, Da-Yeong,Kwak, Ihn-Sil,Park, Young-Seuk 한국하천호수학회 2020 생태와 환경 Vol.53 No.4

We analyzed food sources of 45 fish species in 28 genera of 12 families based on literature data in freshwater ecosystems of South Korea. The food sources of 45 fish species included in a total of 26 phyla, 42 classes, 94 orders, 189 families and 294 genera. Among them, animal food sources were 16 phyla, 24 classes, 54 orders, 126 families and 212 genera, whereas plant food sources were relatively small with 10 phyla, 18 classes, 42 orders, 63 families and 82 genera. The animal food sources were classified into Arthropod, Insecta, Diptera and Chironomidae according to taxa. Meanwhile, Bacillariophyta, Bacillariophyceae, Cymbellales and Cymbellaceae were the most abundant among the plant sources. Self-Organized Map (SOM) and network analysis were conducted the food sources were classified into taxonomic groups and the feeding types of fish : 45 fish species were divided into five groups, characterizing 1) fishvores, 2) invertebratevores, planktivores including 3) zooplankton and 4) phytoplankton, and 5) omnivores. The network analysis presented link association between fishes and food sources. Macroinvertebrate including diptera and ephemeroptera were revealed as hub food sources based on network analysis. This literature study would expect that the application model with the food source of fish could be utilized for the evaluation of the food network or chain in freshwater ecosystems. 국내 담수 어류 12과, 28속, 45종의 먹이원을 문헌 조사한 결과, 동물류 먹이원은 16문, 24강, 54목, 126과, 212속으로 조사되었으며 식물류 먹이원은 10문, 18강, 42목, 63과, 82속으로 나타났다. 동물류 먹이원 중 가장 많은 어류가 섭식한 먹이원은 분류군에 따라 절지동물문, 곤충강, 파리목, 깔따구과로 조사되었으며, 식물류 먹이원은 돌말문, 윷돌말강, 반달돌말목, 반달돌말과로 조사되었다. SOM을 이용하여 45종 어류의 유형화 결과, 어류를 주로 포식하는 어류와 저서무척추동물을 포식하는 어류, 동물플랑크톤을 섭식하는 어류, 식물플랑크톤을 섭식하는 어류, 잡식성 어류 5가지 유형으로 나타났다. 네트워크 분석의 허브 점수가 높은 상위 5종의 어류는 블루길, 몰개, 수수미꾸리, 남방종개, 새코미꾸리 순으로 나타났으며 먹이원 중 허브 점수가 높은 상위 5 종류의 먹이원은 파리목, 하루살이목, 이지목, 김발돌말목, 쪽배돌말목 순으로 조사되었다.