• Title/Summary/Keyword: dolphin

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A Study on the Evaluation of Mooring Safety of LNG Ships (LNG선의 계류 안전성의 평가에 관한 연구)

  • 김세원
    • Journal of the Korean Institute of Navigation
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    • v.24 no.5
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    • pp.373-383
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    • 2000
  • The ship’s safe mooring stability is a principles for the safe cargo handling works at the mooring berth. Today numerous standards, guidelines and recommendations concerning mooring practices, fittings and equipments exist throughout the worldwide maritime industries. In recently, the mooring facilities were constructed as dolphin types at the open sea area apart far from shoreside instead of enclosed coastline area in accordance with increasing ship’s size and for preventing environmental pollution. Therefore the exciting wave condition must be considered as a basic environmental criteria with the wind force and current force for all of the mooring ships at the sea berth facilities. In this study, this added wave force as one of the environmental external forces by using the theoretical formula was applied to the LNG ship in Pyeongtaeg harbor needed the special mooring stability of the sea berth. Through this research, it can be confirmed that wave force is the very important factor in the mooring force and the strength of wave force works much more in the full laden condition than in the lightship condition. And also the wave force changes to non-linear states according to the wave frequency and wave length. In addition, the maximum limit criteria of environmental force of prohibiting the entering ship on the berth and loading works controlled by the port authority concerned of Pyeongtaeg port fully satisfies the condition of the mooring limit force recommended by OCIMF that the safe permitted force of the mooring line have to be within 55 % of MBL.

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Evaluation for Safe Passing of VLCC at the Incheon Port by Analyzing of the Ship Handling Simulation (VLCC의 인천항 안전 입출항을 위한 선박조종 시뮬레이션을 통한 통항안전성 평가)

  • Kim, Se-Won;Choi, Youn-Jung;Lee, Yoon-Suk
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • 2014.06a
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    • pp.46-48
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    • 2014
  • The port of Incheon is very famous of strong current and many curved fairway with exist of many islands around the fairway. Therefore the max size of calling vessel is restricted in 50K DWT with 13.0m draft. However in the near future, half cargo loaded VLCC will call SK energy Dolphin berth for discharging of crude oil. In this connection, this study will evaluate the safety of passing for Dongsudo-fairway by using the shiphandling simulation data that was produced by familiarized training & education for Incheon port pilots about VLCC's maneuvering characters and the fairway of Incheon port.

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Isolation and Characterization of an Extremely Thermophilic Sulfur-metabolizing Bacterium from a Deep-sea Hydrothermal Vent System

  • Kwak, Yi-Seong;Kobayashi, Tetsuo;Akiba, Teruhiko;Horikoshi, Koki;Kim, Young-Bae
    • Journal of Microbiology and Biotechnology
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    • v.4 no.1
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    • pp.36-40
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    • 1994
  • A water sample was taken from a black smoker chimney of a deep-sea hydrothermal vent by using an unmanned submersible "Dolphin 3K". The temperature of the hydrothermal fluid from the black smoker was $276^{\circ}C$. After isolation by repeated serial dilutions, An extremely thermophilic bacterial strain was selected. The strain designated as DT1331, was an anaerobic, non-motile, coccoid shaped bacterium with about 0.5 to $1.0\;\mu\textrm{m}$ in diameter. The strain DT1331 could grow up to $93^{\circ}C$, but the optimum temperature of this strain was $80^{\circ}C$. The growth occurred in the pH range of 4.5 to 8.5 and the optimum pH was 6.0. The strain DT1331 required 1% to 5% NaCl for growth and cell lysis was observed below 1% NaCl concentration. The bacterium could grow on polypeptides such as tryptone, peptone, soytone and on proteins such as casein or gelatin. However, no growth was observed on single amino acids, sugar and organic acids. Hydrogen gas was detected slightly during growth. This bacterium obligately required elemental sulfur and hydrogen sulfide gas was produced during growth.

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Design and Performance Characteristics of a Broadband Underwater Speaker System (광대역 수중 스피커 시스템의 설계 및 성능 특성)

  • Lee, Dae-Jae
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.44 no.5
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    • pp.543-549
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    • 2011
  • An underwater speaker was developed for use as an acoustic deterrent device that transmits acoustic energy through the water omnidirectionally over a broadband frequency range to eliminate marine mammal attacks and to prevent physical damage to the inshore and coastal fishing grounds of Korea. The underwater speaker was constructed of two vibration caps machined from 6061-T6 aluminum alloy and a stack of PZ 26 piezoelectric ceramic rings (Ferroperm Piezoceramics A/S) connected mechanically in series and electrically in parallel. The performance characteristics of the underwater speaker were measured and analyzed in an experimental water tank of $5\;m{\times}5\;m{\times}6\;m$. The peak transmitting voltage response (TVR) was measured at 11.16 kHz with 163.45 dB re $1\;{\mu}Pa$/V at 1m. The underwater speaker showed a near omnidirectional beam pattern at the peak TVR resonance frequency. The usable frequency range was 4-25 kHz with a lower TVR limit of approximately 140 dB. We conclude that this underwater speaker could be satisfactorily used as an acoustic deterrent device against marine mammals, particularly the bottlenose dolphin, to protect catches and fishing grounds as well as the mammals themselves, for example, by keeping them away from fishing gear and/or vessels.

Review of the Korean Vernacular Names of Cetaceans (한반도 근해 고래류의 한국어 일반명에 대한 고찰)

  • Sohn, Hawsun;An, Du Hae;Kim, Doo Nam
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.45 no.5
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    • pp.513-522
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    • 2012
  • This paper reviews the Korean vernacular names of 35 cetacean species found in Korean waters and mentioned in 19 references, including laws, high school textbooks, and books on whales. The vernacular names of 16 species were identical in all sources examined. Some names have their origins in old Korean books, while others have recently entered public awareness through movies, TV programs, and the mass media; some species are frequently studied by researchers. Given the nature of vernacular names, that is, names used by people who live in sympatry with the animals, priority was not given high consideration in this paper. Instead, we carefully investigated the origin, publicity, and rationale of the Korean common names for the 35 species. All of these Korean names are also listed in "The World Cetacea Database (http://www.marinespecies.org/cetacea/)," which contains the most accurate cetacean systematic information on the Web.

Trial manufacture of dual frequency acoustic pinger to minimize cetacean bycatch (고래류 혼획을 최소화하기 위한 다주파 음향 경고시스템의 시험 제작)

  • Lee, Yoo-Won;Shin, Hyeong-Il;Kim, Seok-Jae;Seo, Du-Ok;Lee, Dae-Jae;Kim, Zang-Geun;Hwang, Doo-Jin
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.41 no.3
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    • pp.207-212
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    • 2005
  • Dual frequency acoustic pinger(AP) was manufactured to reduce study effect by long-term use of developed single frequency AP to prevent cetacean bycatch. Directivity characteristic of transducer was the omnidirectional pattern which showed less than ${\pm}3dB$ the change range of sensitivity on the beam pattern of right and left. Source power level(SPL) was 1384311pa with epoxy window before casing however after casing 1170B11Pa at sea. Dual frequency Af was tested to identify the avoidance behavior of bottlenose dolphin by its working. However the efficiency of dual frequency AP about the study effect was verified experiment repeatedly using single and dual frequency AP.

Biosequestration, Transformation, and Volatilization of Mercury by Lysinibacillus fusiformis Isolated from Industrial Effluent

  • Gupta, Saurabh;Goyal, Richa;Nirwan, Jashan;Cameotra, Swaranjit Singh;Tejoprakash, Nagaraja
    • Journal of Microbiology and Biotechnology
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    • v.22 no.5
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    • pp.684-689
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    • 2012
  • In the present study, an efficient mercury-tolerant bacterial strain (RS-5) was isolated from heavy-metalcontaminated industrial effluent. Under shake flask conditions, 97% of the supplemented mercuric chloride was sequestered by the biomass of RS-5 grown in a tryptone soy broth. The sequestered mercuric ions were transformed inside the bacterial cells, as an XRD analysis of the biomass confirmed the formation of mercurous chloride, which is only feasible following the reaction of the elemental mercury and the residual mercuric chloride present within the cells. Besides the sequestration and intracellular transformation, a significant fraction of the mercury (63%) was also volatilized. The 16S rRNA gene sequence of RS-5 revealed its phylogenetic relationship with the family Bacillaceae, and a 98% homology with Lysinibacillus fusiformis, a Gram-positive bacterium with swollen sporangia. This is the first observation of the sequestration and volatilization of mercuric ions by Lysinibacillus sp.

Implementation and Performance Evaluation of a Software-based DSM Sytem for a Windows-NT Workstations Cluster (Windows-NT 워크스테이션 클러스터를위한 소프트웨어 기반 분산 공유 메모리 시스템의 구현 및 성능 평가)

  • Lee, Jong-U
    • Journal of KIISE:Computing Practices and Letters
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    • v.5 no.2
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    • pp.176-184
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    • 1999
  • 지금까지의 소프트웨어 기반 분산 공유 메모리(이하 DSM이라 칭함)시스템은 유닉스 워크스테이션 클러스터를 목표로 하는 것이 대부분이었다. 그러나 현재 Windows-NT 는 서버급 시스템과 PC 모두를 위한 운영체제로서 유닉스와 더불어 널리 사용되고 있는 실정이다. 본 논문에서는 Windows-NT 워크스테이션 클러스터 환경을 위한 DSM 시스템을 구현하고, 구현된 DSM 시스템의 성능 평가 결과를 제시한다. 구현된 DSM 시스템은 Win32 API와 표준 실행-시간 라이브러리를 이용해 구현되었기 때문에 모든 Windows-NT 워크스테이션에서 실행 가능하며 , 프로그래머는 몇 라인의 코드 추가만으로 DSM 시스템 상에서 수행되는 병렬 응용 프로그램을 작성할 수 있다. 워크스테이션 간의 상호연결망으로 범용성을 위해 이더넷 LAN을 지원하였고, 아울러 성능 향상을 위해 기가비트 SAN(System Area Network)도 지원하였다. 기가비트 SAN을 위한 하드웨어로는 Dolphin 사의 PCI-SCI 타입 제품인 Clustar를 사용하였다. 우리는 성능 평가를 통해, 구현된 DSM 시스템이 정확히 동작함은 물론 확장성이 뛰어나다는 것을 확인하였다. 특히 , 기가비트 SAN을 사용할 경우 일부 병렬 벤치 마크 프로그램에서는 노드 수 증가에 따라 성능이 거의 선형적으로 향상된다는 것을 알 수 있었다. 본 논문이 기여하는 바는 Windows-NT 기반 소프트웨어 DSM 시스템의 원천 기술을 확보함으로써 향후 Windows-NT 워크스테이션 클러스터 환경에서의 분산 및 병렬 처리 연구에 도움을 줄 수 있다는 점이다.

CO2 emissions optimization of reinforced concrete ribbed slab by hybrid metaheuristic optimization algorithm (IDEACO)

  • Shima Bijari;Mojtaba Sheikhi Azqandi
    • Advances in Computational Design
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    • v.8 no.4
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    • pp.295-307
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    • 2023
  • This paper presents an optimization of the reinforced concrete ribbed slab in terms of minimum CO2 emissions and an economic justification of the final optimal design. The design variables are six geometry variables including the slab thickness, the ribs spacing, the rib width at the lower and toper end, the depth of the rib and the bar diameter of the reinforcement, and the seventh variable defines the concrete strength. The objective function is considered to be the minimum amount of carbon dioxide gas (CO2) emission and at the same time, the optimal design is economical. Seven significant design constraints of American Concrete Institute's Standard were considered. A robust metaheuristic optimization method called improved dolphin echolocation and ant colony optimization (IDEACO) has been used to obtain the best possible answer. At optimal design, the three most important sources of CO2 emissions include concrete, steel reinforcement, and formwork that the contribution of them are 63.72, 32.17, and 4.11 percent respectively. Formwork, concrete, steel reinforcement, and CO2 are the four most important sources of cost with contributions of 67.56, 19.49, 12.44, and 0.51 percent respectively. Results obtained by IDEACO show that cost and CO2 emissions are closely related, so the presented method is a practical solution that was able to reduce the cost and CO2 emissions simultaneously.

Three-dimensional cone beam computed tomography analysis of temporomandibular joint response to the Twin-block functional appliance

  • Jiang, Yuan-yuan;Sun, Lian;Wang, Hua;Zhao, Chun-yang;Zhang, Wei-Bing
    • The korean journal of orthodontics
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    • v.50 no.2
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    • pp.86-97
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    • 2020
  • Objective: To propose a three-dimensional (3D) method for evaluating temporomandibular joint (TMJ) changes during Twin-block treatment. Methods: Seventeen patients with Class II division 1 malocclusion treated using Twin-block and nine untreated patients with a similar malocclusion were included in this research. We collected their cone beam computed tomography (CBCT) data from before and 8 months after treatment. Segmentations were constructed using ITK-SNAP. Condylar volume and superficial area were measured using 3D Slicer. The 3D landmarks were identified on CBCT images by using Dolphin software to assess the condylar positional relationship. 3D models of the mandible and glenoid fossa of the patients were constructed and registered via voxel-based superimposition using 3D Slicer. Thereafter, skeletal changes could be visualized using 3DMeshMetric in any direction of the superimposition on a color-coded map. All the superimpositions were measured using the same scale on the distance color-coded map, in which red color represents overgrowth and blue color represents resorption. Results: Significant differences were observed in condylar volume, superficial area, and condylar position in both groups after 8 months. Compared with the control group (CG), the Twin-block group exhibited more obvious condyle-fossa modifications and joint positional changes. Moreover, on the color-coded map, more obvious condyle-fossa modifications could be observed in the posterior and superior directions in the Twin-block group than in the CG. Conclusions: We successfully established a 3D method for measuring and evaluating TMJ changes caused by Twin-block treatment. The treatment produced a larger condylar size and caused condylar positional changes.