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      • KCI등재

        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.

      • KCI등재

        새로운 무손실 의료영상 압축방법

        지창우,박성한 한국통신학회 1996 韓國通信學會論文誌 Vol.21 No.11

        In this papr, a new lossless compression method is presented based on the Binary Adaptive Arithmetic Coder(BAAC). A simple unbalanced binary tree is created by recursively dividing the BAAC unit interval into two probability sub-inervals. On the tree the More Probable Predicted Value(MPPV) and Less Probable Predicated Value(LPPV) estimated by local statistics of the image pixels are arranged in decreasing order. The BAAC or Huffman coder is thus applied to the branches of the tree. The proposed method allows the coder be directly applied to the full bit-plane medical image without a decomposition of the full bit-planes into a series of binary bit-planes. The use of the full bit model template improves the compresion ratio. In addition, a fast computation for adjusting the interval is possible since a simple arithmetic operation based on probability interval estimation state machine is used for interval sub-division within the BAAC unit interval.

      • KCI등재

        기주에 따른 목화검정진디벌(Ephedrus plagiator (Nees))과 진디벌(Aphidius ervi Haliday)의 생물학적 특성 비교

        지창우,강은진,변영웅,김정환,최병렬,Ji, Chang Woo,Kang, Eun Jin,Byeon, Young-Woong,Kim, Jeong-Hwan,Choi, Byeong Ryeol 한국응용곤충학회 2014 한국응용곤충학회지 Vol.53 No.4

        싸리수염진딧물(Aulacorthum solani) 방제를 위해 기생성 천적으로 국내에서 선발한 목화검정진디벌(Ephedrus plagiator)과 외국에서 판매되고 있는 진디벌(Aphidius ervi)을 비교 조사하였다. 성충 수명과 산란 기간, 머미수, 우화충수 등에 대한 우열성을 싸리수염진딧물과 완두수염진딧물(Acyrthosiphon pisum)을 대상으로 온도 15, 20, 25, $30^{\circ}C$와 광주기 16(L) : 8(D)의 조건에서 조사하였다. 성충 수명은 $15^{\circ}C$에서 목화검정진디벌이 싸리수염진딧물에서 5.9일로 진디벌 3.6일에 비해 2.3일 길었다. 산란 기간도 $15^{\circ}C$의 싸리수염진딧물에서 목화검정진디벌이 5.3일인 반면, 진디벌은 2.2일로 상대적으로 짧았다. 싸리수염진딧물에서 목화검정진디벌과 진디벌의 머미수는 목화검정진디벌이 15, 20, 25, $30^{\circ}C$에서 각각 71.5, 41.0, 15.7, 7.7개로 진디벌의 22.1 16.3 6.2, 0.4 보다 많이 기생하는 것으로 나타났다. 반면에 완두수염진딧물에서 목화검정진디벌의 머미수는 70.3, 69.8, 34.3, 8.4개로 93.4, 71.2, 34.8, 14.5로 조사된 진디벌의 머미수보다 낮았다. 싸리수염진딧물에서 목화검정진디벌의 우화충수는 42.1, 36, 11.6, 0로 나타나 $30^{\circ}C$의 높은 온도에서는 우화하지 않은 것을 알 수 있었다. 진디벌의 경우에는 우화 개체수가 각 온도에서 19.6, 13.5, 3.7, 0.1로 나타나 목화검정진디벌에 비해 상대적으로 적게 우화한 것으로 조사되었다. 두 종의 비교결과, 싸리수염진딧물에서는 목화검정진디벌이, 완두수염진딧물에서는 진디벌이 우수한 것으로 조사되었다. To investigate the biological control of Aulacorthum solani, a comparative analysis was carried out using an indigenous natural enemy, Ephedrus plagiator, and an exotic parasitoid, Aphidius ervi. Lifespan, spawning periods, number of mummies, number of offspring, and developmental periods of the two parasitoids on Aulacorthum solani and Acyrthosiphon pisum were studied at 15, 20, 25, and $30^{\circ}C$ with a photoperiod 16 h (L): 8 h (D). The lifespan of E. plagiator (5.3 days) was relatively higher than that of A. ervi (2.3 days) when these parasitoids were reared on A. solani at $15^{\circ}C$. Similarly, the spawning period of E. plagiator (5.3 days) was longer than that of A. ervi (2.2 days). When the two aphid parasitoids were provisioned with A. solani, the numbers of E. plagiator mummies at 15, 20, 25, and $30^{\circ}C$ were 71.5, 41, 15.7, and 7.7, respectively, whereas at the same temperatures, the numbers of A. ervi mummies were 22.1 16.3, 6.2, and 0.4, respectively. In contrast, when provision with A. pisum, the numbers of E. plagiator mummies at 15, 20, 25, and $30^{\circ}C$ were 70.3, 69.8, 34.3, and 8.4, whereas the numbers of A. ervi mummies were 93.4, 71.2, 34.8, and 14.5, respectively. The numbers of E. plagiator offspring emerging at 15, 20, 25, and $30^{\circ}C$ were 42.1, 36, 11.6, and 0, whereas the numbers of A. ervi offspring emerging were relatively lower at 19.6, 13.5, 3.7, and 0.1, respectively. By comparing these results, it can be concluded that E. plagiator is a more efficient parasitoid of A. solani, whereas A. ervi is more efficient on A. pisum.

      • KCI등재후보

        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.

      • KCI등재

        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.

      • KCI등재

        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.

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