• 제목/요약/키워드: Marine science

검색결과 9,353건 처리시간 0.035초

The design method research of the control system for Autonomous Underwater Vehicle (AUV) using Linear Matrix Inequality (LMI)

  • Nasuno, Youhei;Shimizu, Etsuro;Aoki, Taro;Yomamoto, Ikuo;Hyakudome, Tadahiro;Tsukioka, Satoshi;Yoshida, Hiroshi;Ishibashi, Shojiro;Ito, Masanori;Sasamoto, Ryoko
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 2005년도 ICCAS
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    • pp.1060-1065
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    • 2005
  • An Independent Administrative Corporation Japan Agency for Marine-Earth Science and Technology (JAMSTEC) is developing light-and-small Autonomous Underwater Vehicles (AUV)$^{1)}$, named 'MR-X1' (Marine Robot Experimental 1), which can cruise, investigate and observe by itself without human's help. In this paper, we consider the motion control problem of 'MR-X1' and derive a controller. Since the dynamic property of 'MR-X1' is changed by the influence of the speed, the mathematical model of 'MR-X1' becomes the nonlinear model. In order to design a controller for 'MR-X1', we generally apply nonlinear control theories or linear control theories with some constant speed situation. If we design a controller by applying Linear Quadratic (LQ) optimal control theory, the obtained controller only compensates t e optimality at the designed speed situation, and does not compensate the stability at another speed situations. This paper proposes a controller design method using Linear Matrix Inequalities (LMIs)$^{2),3),4)}$, which can adapt the speed variation of 'MR-X1'. And examples of numerical analysis using our designed controller are shown.

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Effect of Epigallocatechin Gallate on Viability of Kudoa septempunctata

  • Shin, Sang Phil;Hong, Hyun Ki;Jin, Chang Nam;Sohn, Hanchang;Choi, Kwang Sik;Lee, Jehee
    • Parasites, Hosts and Diseases
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    • 제58권5호
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    • pp.593-597
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    • 2020
  • Kudoa septempunctata have been reported as a causative agent for acute transient gastrointestinal troubles after eating raw olive flounder (Paralichthys olivaceus). It raised public health concerns and quarantine control in several countries. Quantitative evaluation on viability of K. septempunctata is crucial to develop effective chemotherapeutics against it. A cytometry using fluorescent stains was employed to assess effect of three compounds on viability of K. septempunctata. Epigallocatechin gallate reduced markedly viability of K. septempunctata at 0.5 mM or more, and damaged K. septempunctata spores by producing cracks.

Expressed Sequence Tags Analysis of Black Rockfish (Sebastes schlegeli) Peripheral Leukocytes Stimulated with Con A/PMA or LPS

  • Baeck, Gun-Wook;Kim, Ju-Won;Kim, Ki-Hyuk;Jun, Kwan-Yong;An, Geun-Hee;Park, Chan-Il
    • 한국어병학회지
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    • 제21권2호
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    • pp.129-137
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    • 2008
  • We constructed a black rockfish (Sebastes schlegeli) leukocyte cDNA library and a total of 386 expressed sequence tag (EST) clones were generated. Gene annotation procedures and homology searches of the sequenced ESTs were locally done by BLASTX for amino acid similarity comparisons. Of the 386 EST clones, 199 different ESTs showed significant homology to previously described genes while 97 ESTs were unidentified, hypothetical, or unnamed proteins. Encoding 38 different sequences were identified as putative bio-defense genes or genes associated with immune response.

Evaluation of the Biological Activities of Marine Bacteria Collected from Jeju Island, Korea, and Isolation of Active Compounds from their Secondary Metabolites

  • Kim, Hyun-Soo;Zhang, Chao;Lee, Ji-Hyeok;Ko, Ju-Young;Kim, Eun-A;Kang, Nalae;Jeon, You-Jin
    • Fisheries and Aquatic Sciences
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    • 제17권2호
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    • pp.215-222
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    • 2014
  • To explore marine microorganisms with medical potential, we isolated and identified marine bacteria from floats, marine algae, animals, and sponges collected from Jeju Island, Korea. We isolated and identified 21 different strains from the marine samples by 16S rRNA analysis, cultured them in marine broth, and extracted them with ethyl acetate (EtOAc) to collect secondary metabolite fractions. Next, we evaluated their anti-oxidative and anti-inflammatory effects. Among the 21 strains, the secondary metabolite fraction of Bacillus badius had both strong antioxidant and anti-inflammatory activity, and thus was selected for further experiments. An antioxidant compound detected from the secondary metabolite fraction of B. badius was purified by preparative centrifugal partition chromatography (n-hexane:EtOAc:methanol:water, 4:6:4:6, v/v), and identified as diolmycin A2. Additionally, diolmycin A2 strongly inhibited nitric oxide production. Thus, we successfully identified a significant bioactive compound from B. badius among the bacterial strains collected from Jeju Island.

A comparative study of Sargassum horneri Korea and China strains collected along the coast of Jeju Island South Korea: its components and bioactive properties

  • Kim, Hyun-Soo;Sanjeewa, K.K. Asanka;Fernando, I.P. Shanura;Ryu, BoMi;Yang, Hey-Won;Ahn, Ginnae;Kang, Min Cheol;Heo, Soo-Jin;Je, Jun-Geon;Jeon, You-Jin
    • ALGAE
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    • 제33권4호
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    • pp.341-349
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    • 2018
  • Sargassum horneri is edible brown seaweed abundant along the coasts of Jeju Island, South Korea. In addition to the native S. horneri population, a large amount of S. horneri has been found to invade Jeju Island from the east coast of China. Thus, S. horneri of both Korea (SK) and China (SC) strains now inhabits along with the shore of Jeju Island and have become a threat to the coastal biodiversity. However, they could be used in obtaining functional ingredients for industrial level applications provided an optimized cost effective strategy. In the present study, we compared SK and SC strains for the extraction efficiency, components, antioxidant, and anti-inflammatory properties of 80% methanolic extracts and their partially purified fractions. According to the results, two strains indicated similar bioactive properties such as DPPH and alkyl radical scavenging activity as well as anti-inflammatory activities on lipopolysaccharide-stimulated RAW 264.7 cells. The yield of 80% methanol extract from SC was higher than SK. However, the yields of the ethyl acetate and chloroform fractions from SK were higher than those of SC strain. The major peaks in the high-performance liquid chromatography chromatograms, which was identified as Apo-9 fucoxanthinone, indicated that both methanolic extracts of SK and SC contains major target peaks but with different amounts. This study might be useful for developing functional materials from SC and SK in future.

한국 동해 연안에 출현하는 도루묵(Arctoscopus japonicus)의 식성 (Feeding Habits of the Sandfish, Arctoscopus japonicus in the Coastal Waters of East Sea, Korea)

  • 진수연;김도균;성기창;강다연;이주은;박현솔;양혜진;서호영;백근욱
    • 한국어류학회지
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    • 제34권2호
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    • pp.113-118
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    • 2022
  • 이번 연구에 사용된 도루묵은 2020년 1월부터 2021년 12월까지 우리나라 동해에서 동해구외끌이저인망과 연안자망 어업을 통해 총 781개체를 채집하였다. 채집된 도루묵의 전장범위는 14.8~25.4 cm였다. 도루묵의 가장 중요한 먹이생물은 54.7%의 상대중요도지수비를 나타낸 단각류였으며, 그 다음으로는 각각 33.7%와 11.6%를 차지한 두족류와 난바다곤쟁이류였다. 그외 게류, 새우류, 어류, 갯지렁이류가 출현하였으나 그 양은 매우 적었다. 계절별 위내용물 조성을 살펴본 결과, 모든 계절에 단각류를 주로 섭식하였으며, 여름철에 두족류의 섭식비율이 가장 높았으며, 봄철에 난바다곤쟁이류의 비율이 가장 높았다. 크기군별 위내용물 조성을 살펴본 결과, 도루묵은 모든 크기군에서 단각류가 가장 중요한 먹이생물이었으며, 성장함에 따라 단각류와 난바다곤쟁이류의 비율은 감소하고 두족류의 비율은 증가하는 경향이 관찰되었다. 개체당 평균먹이생물 개체수는 유의한 차이를 보이지 않은 반면, 중량은 크기군이 증가함에 따라 증가하는 경향이 관찰되었다.

해양독소를 보유한 연체동물의 기관별 명칭과 생태학적 특성에 관하여 (Anatomical and Ecological Characteristics of Marine Biotoxin-Bearing Mollusks)

  • 홍현기;;김현중;이완옥;이지현;최광식
    • 한국식품위생안전성학회지
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    • 제36권6호
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    • pp.455-473
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    • 2021
  • 이 총설에서는 해양 연체동물 내 독소 분석을 하는 연구자들의 이해를 돕기 위하여, 국내에서 생산되거나 유통되는 수산물 중 해양 생물독소에 오염될 수 있는 이매패류와 복족류 종들의 공식 명칭과 생태학적 특성을 소개하였다. 또한 대표적인 생물군의 해부도를 통한 각 기관들의 위치와 공식적인 명칭을 알리고자 하였다. 향후 해양생물독소 분석 관련 식품공전, 학술논문 및 보고서에 실험생물의 정확한 종명과 분석 기관의 명칭에 대한 통일 및 규격화가 필요하다.

Haemocytes responses of the pearl oyster, Pincdata fucata, at different temperatures

  • Choi, Young-Joon;Hwang, Jee-Youn;Baeck, Gun-Wook;Kim, Mu-Chan;Park, Hyung-Jun;Choi, Byoung-Dae;Kang, Suk-Joong;Park, Chan-Il
    • 한국어병학회지
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    • 제21권3호
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    • pp.241-246
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    • 2008
  • The effects of temperatures on pearl oyster, Pincdata fucata were studied by evaluating some functional immune responses of the haemocytes. Water temperature is one of the most important factors in bivalve immune defense. Haemocytes comprise a primary line by inflammation, encapsulation and phagocytosis. These phagocytic abilities of haemocytes were observed in different temperatures. The number of the circulating haemocytes by migratory assay, phagocytic activities by MTT assay and reactive oxygen species production of haemocytes by CL assay were measured at different temperatures. Results showed that pearl oyster maintained at 20℃ and 25℃ displayed significantly higher values for all the measured immune parameters in comparison to maintained at 10, 15, and 30℃.