• 제목/요약/키워드: marine investigation

검색결과 887건 처리시간 0.03초

Numerical investigation of tip clearance effects on the performance of ducted propeller

  • Ding, Yongle;Song, Baowei;Wang, Peng
    • International Journal of Naval Architecture and Ocean Engineering
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    • 제7권5호
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    • pp.795-804
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    • 2015
  • Tip clearance loss is a limitation of the improvement of turbomachine performance. Previous studies show the Tip clearance loss is generated by the leakage flow through the tip clearance, and is roughly linearly proportional to the gap size. This study investigates the tip clearance effects on the performance of ducted propeller. The investigation was carried out by solving the Navier-Stokes equations with the commercial Computational Fluid Dynamic (CFD) code CFX14.5. These simulations were carried out to determine the underlying mechanisms of the tip clearance effects. The calculations were performed at three different chosen advance ratios. Simulation results showed that the tip loss slope was not linearly at high advance due to the reversed pressure at the leading edge. Three type of vortical structures were observed in the tip clearance at different clearance size.

세일링보트 개발을 위한 한선선형 연구 (A Study on the HANSUN Boat Type for Development of Sailing Boat)

  • 박근옹;김동준
    • 한국해양공학회:학술대회논문집
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    • 한국해양공학회 2003년도 추계학술대회 논문집
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    • pp.53-59
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    • 2003
  • The Study of Hansun(Traditional Fishing Boat of Korea) is based on Fishing Bost Investigation Report which began in 1921. The Report was completed in 1927 with the conclusion of Southern sea Region and Western sea Region studies which included the investigation of the entire region. Based on this report, this paper surveys Hansun's characteristics style of boat and performance. The First couple of chapters are possibility of combining type of Hansun and modern Sailing Boat. As a result we find out that the hull form of Hansun is very similar with that of modern sailing boats and is a good candidate for the mother ship to develop the modern sailing boats for Korean sea.

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성인학습자의 자기인식을 위한 코어 다이내믹 측정도구 개발 (A Study on Development of the Core Dynamic Scale for Adult Learner)

  • 정폴진우;박현숙;김재현;김희동;강창수
    • 수산해양교육연구
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    • 제27권4호
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    • pp.1099-1108
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    • 2015
  • The purpose of this study is to develop a feasible and reliable tool to diagnose human's core dynamic. For this, 40 questions were developed based on literature analysis and interviews and through Delphi survey and validity and reliability analysis, an investigation tool comprised of 30 questions in 8 areas were developed finally. The investigation tool developed in this study can be utilized in measuring the obstacles and negativity that obstruct changes in individuals and in particular, it is expected to be useful in discovering obstacles that obstruct the development of members in actual organizations and resolving them. Moreover, this investigation tool can also be utilized in coaching organizations and individuals, mentoring and consultation.

해양 IT시스템용 적응형 모니터링 센서의 개발 및 성능 평가 (The Development and Performance Evaluation of Adaptive Monitoring sensor for the Marine IT System)

  • 조정환;노희정
    • 조명전기설비학회논문지
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    • 제29권6호
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    • pp.90-95
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    • 2015
  • This paper proposes the new adaptive gain control monitoring sensor for the marine IT system. The marine IT system sensors make it possible to conduct search missions, record climate changes, provide pollution control, study marine life, conduct survey missions, tactical surveillance, and predict natural disturbances in the ocean. In this paper, the adaptive gain control circuit which changes its parameters according to the ambient noise situation for obtaining the precise location information of marine IT system sensor is developed and analyzed. The performance characteristics for ensuring the precise location information of marine system sensor is presented and analyzed. The theoretical and experimental studies have been carried out. The presented results from the above investigation show considerably excellent performance for the monitoring of the marine system.

해양설비용 정밀 모니터링 센서의 개발 및 특성 분석 (The Development and Characteristics Analysis of High Precision Monitoring Sensor for the Marine Installation)

  • 조정환;고성원
    • 조명전기설비학회논문지
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    • 제27권10호
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    • pp.101-106
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    • 2013
  • This paper proposes the new high precision monitoring sensor for the Marine Installation. Among variety of sensor network systems, wireless information transmission through the marine is one of the enabling technologies for the development of future marine-observation systems and sensor networks. Applications of marine monitoring range from oil industry to aquaculture, and include instrument monitoring, pollution control, climate recording, prediction of natural disturbances. For these marine applications to be available, however, the provision of precise location information using monitoring sensor is essential. In this paper, the dynamic characteristics for obtaining the location information of monitoring sensor is analyzed. The theoretical and experimental studies have been carried out. The presented results from the above investigation show considerably excellent performance for the Monitoring for the Marine Installation.

해양설비용 센서의 다중 신호처리 회로 개발 및 성능 분석 (The Development and Performance Analysis of Multiple Signal Processing Circuit for Marine Installation Sensor)

  • 조정환;고성원
    • 조명전기설비학회논문지
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    • 제28권12호
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    • pp.84-89
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    • 2014
  • This paper proposes the new multiple signal processing monitoring sensor for the marine installation. The recent marine technology is focused on underwater sensors and underwater sensor networks in order to measure, monitor, surveillance of and control of underwater environments. For these marine applications to be available, however, the provision of precise location information using monitoring sensor is essential. In this paper, the multiple signal processing circuit for obtaining the precise location information of marine installation sensor is developed and analyzed. The performance characteristics for obtaining the location information of marine installation sensor is analyzed. The theoretical and experimental studies have been carried out. The presented results from the above investigation show considerably excellent performance for the monitoring for the marine installation.

Long-Term Investigation of Marine-Derived Aspergillus Diversity in the Republic of Korea

  • Jun Won Lee;Wonjun Lee;Rekhani Hansika Perera;Young Woon Lim
    • Mycobiology
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    • 제51권6호
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    • pp.436-444
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    • 2023
  • Aspergillus species play a crucial role in terrestrial environments as degraders and are well known for producing various secondary metabolites. Recently, Aspergillus species have been discovered in marine environments, exhibiting adaptability to high salinity and producing diverse secondary metabolites with valuable properties. However, limited research has focused on their marine diversity, leading to inaccurate species identification. The current study addresses this gap by investigating diverse marine habitats in the Republic of Korea, including sediment, seawater, seaweed, and marine animals. From three coasts of the Korean Peninsula, 472 Aspergillus strains were isolated from the various marine habitats. A total of 41 species were accurately identified using multigenetic markers: internal transcribed spacer, calmodulin, and b-tubulin. The findings underscore the importance of accurate identification and provide a basis for elucidating the functional role of marine-derived Aspergillus species in marine ecosystems.