• 한국수산과학회지
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• 제28권3호
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• pp.347-353
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• 1995

훈제 굴 기름담금 통조림은 우리나라의 대표적인 수출용 수산물 통조림이지만, 가열살균공정의 기준이 정립되어 있지 않아서 생산공정에서 과잉열처리와 그에 따른 에너지의 낭비 및 품질저하를 피하지 못하고 있다. 따라서 본 연구에서는 가열살균공정에서의 에너지 소비와 제품의 미생물학적 안전성을 최적화하고자 하였다. 원료 생굴에서 검출된 대부분의 미생물은 증식속도가 빠르고 부패력이 강한 것이었다. 정상적인 전처리 후에 $110^{\circ}C$에서 Fo-값 5.92min으로 살균한 훈제 굴 기름담금 통조림에서는 장기 저장중에도 미생물이 전혀 검출되지 않았다. 따라서 훈제 굴 기름담금 통조림의 Fo-값으로는 6.0min 정도가 적당한 것으로 판단되었다.

• 한국유체기계학회 논문집
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• 제17권6호
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• pp.38-43
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• 2014

In Ocean, the temperature of the deep sea water is always lower than that of the surface sea water. The temperature difference between the surface water and deep sea water is about $20^{\circ}C$. Based on thermodynamics, this temperature difference can be converted into mechanical power. The mechanical power can be converted to electricity through a generator. However, the temperature difference is relatively small compared with that of traditional steam turbines. It is difficult to apply the steam turbine technology for this small temperature difference directly. Therefore, the turbine for OTEC system using low temperature difference should be designed to meet the system requirement. The present study focuses on the development of the turbine for 20 kW OTEC system using R32. The paper includes the determination of working fluids, meridional design, turbine layout and 3D CFD results. With off-design points analysis, the full performance of 20kW OTEC turbine is investigated. Through the research, one stage radial type turbine with R32 as working fluid is successfully developed and can be applied to other high temperature heat source.

• 한국양식학회지
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• 제3권1호
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• pp.1-11
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• 1990

참돔의 산란조절은 광주기 l1L: 13D, 수온 $12.2^{\circ}C$에서 시작되어 장일조건 14L:10D, 고수온으로 처리한 결과 $16.5^{\circ}C$에서 산란이 일어났다. 사육수온 $17.0^{\circ}C$ 전후로 유지시켰을 때 산란은 56일간 계속되었고, 자연상태보다 약 1개월 조기채난할 수 있었다. 총산란양은 908만 개이었고 1일 산란양은 15만 개이었다. 명주기와 암주기의 시각별 산란은 18$\~$24시에 많았으나 비교적 분산되어 일어났다. 산란중기에 산란된 난들은 부상수정률이 $71.5\%$였고, 난경은 0.95$\~$0.98mm이었으며, 산란양과는 낮은 상관(r=0.49)을 가졌다. 유구수에 따른 부화율은 1개 $85.3\%$, 2개 $76.9\%$, 3개 $74.3\%$, 4개 $76.6\%$, 5개 이상이 $63.9\%$ 로서 유구수가 많을수록 부화율은 감소하였다. 산란된 전체 난의 산란부터 부화까지의 생존율은 $65\%$이었다.

• Ocean and Polar Research
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• 제25권spc3호
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• pp.353-360
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• 2003

Estimation of undrained shear strength $(S_u)$ of clayey soils from piezocone penetration test (CPTu), which has widely been known as one of very promising in situ test methods, requires piezocone factors. Empirical correlations are generally utilized to derive piezocone factors, but previous studies on the empirical piezocone factors are site-specific and in some cases need engineering characteristics, which should be obtained from additional laboratory tests. In this study, empirical cone factors were evaluated by comparing 6 CPTu results at Shihwa region in Korea with reference $S_u$ values obtained from field vane test (FVT). From previous CPTu results of other regions in Korea as well as the results herein, the correlations between piezocone factor, $N_{kT}$ and CPTu results were investigated and three simplified evaluation methods of $S_u$ using only CPTu results were presented. The $S_u$ values estimated by $(q_T-{\sigma}_v)/{\sigma}'_v$ method shows better matches with those obtained from laboratory tests for marine clays at Shihwa region.

• 대한원격탐사학회지
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• 제33권2호
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• pp.125-134
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• 2017

최근 위성 기반 윈격 탐사 기술의 발전과 더불어 대용량 위성 자료를 효율적으로 처리하기 위한 능력이 요구되고 있다. 이 연구에서는 대용량 GOCI 산출물을 효율적으로 재처리하기 위해 서버가상화와 분산처리를 기반으로 한 GOCI 산출물 재처리 시스템(GOCI Products Re-processing System; GPRS)을 개발하는데 집중하였다. 실험 결과 GPRS를 이용하여 메모리 및 CPU의 사용률을 각각 약 100%, 75%까지 올릴 수 있었다. 이는 제안 시스템을 통해 하드웨어 자원을 절약함과 동시에 작업 처리 속도를 향상시킬 수 있다는 것을 의미한다.

• 대한원격탐사학회지
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• 제32권6호
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• pp.703-719
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• 2016

이 연구는 여름철 동해안 냉수대의 시공간적 이동에 따른 변화 분석에 관한 것이다. 2013년 여름에 위성 및 현장자료(바람, 기온, 수온)를 이용하여 다양한 환경 요인들에 기반을 둔 자료 분석을 시도하였다. 냉수대의 생성과 소멸의 영상을 분석하기 위해 AVISO 지형류 및 하루 동안의 천리안 해양관측위성(Geostationary Ocean Color Imager; GOCI) 엽력소 농도 자료를 사용하였다. 또한, 냉수대의 이동을 추적하기 위해 Advanced Very High Resolution Radiometer-Sea Surface Temperature (AVHRR-SST) 자료를 사용하였다. 초여름에 냉수대가 발현하여 늦여름에 소멸한다는 것과 이 기간 동안 냉수대의 생성과 소멸이 지속적으로 반복되었다는 것을 확인할 수 있었다. 추가적으로 냉수대의 후속 영향으로 인해 늦여름에 엽력소 농도가 증가되었다는 것을 확인할 수 있었다.

• 해양환경안전학회지
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• 제12권1호
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• pp.15-22
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• 2006

해양은 인류가 앞으로 풀어야 할 숙명적인 문제인 식량문제, 자원문제, 환경문제를 해결할 수 있는 마지막 보루이다. 이러한 점을 감안하여 국내 산 학 연 전문가가 참여하여 추진한 $\ulcorner$해앙과학기술(MT) 개발 계획$\lrcorner$ 이 2004년 7월 28일 대통령을 위원장으로 하는 국가과학기술위원회 심의에 통과됨으로써 우리나라에서도 본격적으로 MT 개발을 추진할 기반을 마련하게 되었다. 또한, 2005년 6월부터 $\ulcorner$MT개발기획$\lrcorner$을 효율적으로 추진하기 위한 후속조치로 해양과학기술 로드맵(MTRM) 수립을 추진하여 2005년 12월에 완료하였다. 본 연구에서는 MT의 국내외 기술개발동향과 현재 직면한 현안문제 및 MTRM수립 결과를 고찰하고, MT R&D 전문기관 설치 운영 및 예산확보 등 MT 활성화 방안을 제시하였다.

• 한국해양공학회지
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• 제36권3호
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• pp.153-160
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• 2022

Moored floating platforms have great potential in ocean engineering applications because a mooring system is necessary to keep the platform in station, which is directly related to the operational efficiency and safety of the platform. This paper briefly introduces the technical and operational details of an optical sensor for measuring the tension of mooring lines of a moored platform in waves. In order to check the performance of optical sensors, an experiment with a moored floating platform in waves is carried out in the wave tank at Changwon National University. The experiment is performed in regular waves and irregular waves with a semi-submersible and triangle platform. The performance of the optical sensor is confirmed by comparing the results of the tension of the mooring lines by the optical sensor and tension gauges. The maximum tension of the mooring lines is estimated to investigate the mooring dynamics due to the effect of the wave direction and wavelength in the regular waves. The significant value of the tension of mooring lines in various wave directions is estimated in the case of irregular waves. The results show that the optical sensor is effective in measuring the tension of the mooring lines.

• Ocean and Polar Research
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• 제41권4호
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• pp.289-309
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• 2019

Marine microalgae have long been used as food additives and feeds for juvenile fish and invertebrates as their nutritional content is beneficial for humans and marine aquaculture species. Recently, they have also been recognized as a promising source for cosmeceutical, nutraceutical, and pharmaceutical products as well as biofuels. Marine microalgae of various species are rich in multiple anti-oxidant phytochemicals and their bioactive components have been employed in cosmetics and dietary supplements. Oil contents in certain groups of marine microalgae are extraordinarily rich and abundant and therefore have been commercialized as omega-3 and omega-6 fatty acid supplements and mass production of microalgae-based biodiesels has been demonstrated by diverse research groups. Numerous natural products from marine microalgae with significant biological activities are reported yearly and this is attributed to their unique adaptive abilities to the great diversity of marine habitats and harsh conditions of marine environments. Previously unknown toxin compounds from red tide-forming dinoflagellates have also been identified which opens up potential applications in the blue biotechnology sector. This review paper provides a brief overview of the biotechnological potentials of Korean marine microalgae. We hope that this review will provide guidance for future marine biotechnology R&D strategies and the various marine microalgae-based industries in Korea.

• 수산해양기술연구
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• 제47권4호
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• pp.281-289
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• 2011

The purpose of this study is to identify the flow resistance of the bottom trawl net. The bottom trawl net being used in the training ship of Chonnam National University was selected as a full-scale net, and model nets such as 1/10, 1/25 and 1/50 of the actual net were made. Total resistance of the net part, the height of the net mouth and the flow resistance of components of the net such as wing, bag and cod-end part was measured, converted into full-scale and compared. Additionally, the model rule of Tauti (1934), which has been most frequently used in fishing net modeling experiments, was applied to interpret flow resistance and scale effect of model experiment was investigated. Presumed that the flow resistance R is $R=kS{\upsilon}^2$ against the flow velocity of each net ${\upsilon}$, resistance coefficient k was calculated by substituting R, ${\upsilon}$ and S of the net. From the result, it was found that k decreases exponentially when u increases which makes $k=c{\upsilon}^{-m}$. Whereas m of each net is ranged between 0.13-0.16 and there was not significant difference between nets. c does not show big difference in 1/10 and 1/25 model and the value itself was relatively bigger than in 1/50 model. The height of the net mouth of 1/25 and 1/50 model net h decreases exponentially according as ${\upsilon}$ increases to make $h=d{\upsilon}^{-n}$. Whereas d and n values were almost same in two nets. Additionally, when resistance of cod-end, wing and bag part in 1/25 and 1/50 model nets, both nets showed big resistance in bag part when flow is 1m/s as more than 60%. Wing and cod-end part showed almost same value or wing part had little bit larger value. On the other hand, when reviewing the reasons why both models showed difference in 1/50 model while c value against the resistance coefficient k did not show big difference in 1/10 and 1/25 model, it is inferred that the difference occurred not from material difference but from the difference in net size according to scale. It was judged that they are the scale effects concomitant to the model experiments.