• 한국수산과학회지
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• 제44권5호
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• pp.516-523
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• 2011

To compare four populations of sea squirt Halocynthia roretzi adults, their egg quality and larval development were investigated in the hatchery. The populations were: south sea wild (SSW), south sea cultured (SSC), east sea wild (ESW) and Iwate Japan cultured (IJC). Egg quality and larval development were compared using 13 factors (fertilization rate and diameter, proximate composition, amino acid and fatty acid contents of eggs, hatching rate and various sizes of tadpole larvae) which were obtained from each population. Fertilized egg diameter, hatching rate and size of tadpole larvae were significantly different among the four populations (P<0.05). Eggs were produced with higher crude protein ($5.20{\pm}0.00%$ SSW, $4.71{\pm}0.01%$ ESW, $4.66{\pm}0.01%$ SSC and $3.96{\pm}0.01%$ IJC) and lipid ($1.22{\pm}0.01%$ ESW, $1.01{\pm}0.00%$ SSW, $0.77{\pm}0.01%$ SSC and $0.69{\pm}0.00%$ IJC,) contents from domestic wild populations than from Japanese or cultured populations. Also amino acid and fatty acid contents were different. The extent of similarity between domestic and Japanese populations (30.5% IJC:SSW, 34.3% IJC:SSC and 40.7% IJC:ESW) was relatively low but was very high between SSW and SSC (73.9%). These results may have been due to differences in the abundance of food types and environmental conditions in the four localities and consequent differences in the diets of the sea squirts.

• 수산경영론집
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• 제53권2호
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• pp.58-72
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• 2022

Fishery products play an important role in Korean food culture, and awareness of the safety of fishery products is increasing in the seafood market. Against this backdrop, Japan has announced a plan to release radioactive water to the sea from 2023. In the case of Korea, it is adjacent to the area to be discharged, so there are concerns about securing the safety of marine products. Therefore, it is necessary to analyze the change in perception and impact of marine product consumers due to the discharge of contaminated water and to study appropriate countermeasures when discharging contaminated water from nuclear power plants. In this study, the current status of radioactive contaminated water discharge in Japan was summarized, and a survey was conducted on the change in the consumption perception of marine products according to the discharge of contaminated water to analyze the factors affecting the consumption change of domestic consumers. According to the survey, 85.3% of the respondents said that it will affect the purchase of domestic marine products if Japan starts discharging contaminated water from nuclear power plants. Moreover, 85.5% of the respondents said it will affect the purchase of imported marine products.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2019년도 추계 학술논문 발표대회
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• pp.195-196
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• 2019

The purpose of this study is to analyze the scale of overseas design orders in Korea, China and Japan by region and type of work, and to draw implications. As a result of analyzing the overseas design sales market of Korea, China and Japan, all three countries have the highest percentage of overseas sales in the Asian market, and the overseas design sales are the highest in power generation, chemical plant and transportation sectors. In addition to the Middle East and Asian markets, Japan and China have also diversified their strategies to diversify their markets by taking orders in various regions such as Europe, Africa and the United States. In particular, China is promoting the "New Silk Road Project" (One belt, One road), linking land and sea to a total of 25 countries and actively supporting aid projects in Africa and Asia, have. In addition, Japan has been actively supporting the government's expansion of ODA projects to expand overseas market entry. Therefore, it is necessary for Korea to increase its market share through diversification of overseas design market and diversification of industrial type, and to participate in overseas design market by expanding customized R&D investment.

• 한국환경과학회지
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• 제18권8호
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• pp.841-845
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• 2009

In this paper, offshore wind resources within the Japan's EEZ (Exclusive Economic Zone) are assessed using wind speed data from the microwave scatterometer SeaWinds onboard QuikSCAT. At first, from the 10m-height wind speed from QuikSCAT, 60 m-height wind speed is estimated by using an empirical equation for height correction. Based on the 60 m-height wind speeds, annual energy Production is calculated under an assumption of installing 2 MW wind turbines every $0.64km^2$. The annual energy production is then accumulated for the entire Japan's territorial waters and EEZ ($4.47{\times}10^6km^2$). As a result, it is shown that the total energy Production is estimated to be $4.86{\times}10^4$ TWh/yr. This offshore wind energy Potential within the EEZ is approximately 50 times higher than the actual annual electricity production in Japan.

• 한국해양학회지
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• 제26권1호
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• pp.59-66
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• 1991

동해 심해분지 시추퇴적물 (수심, 1850 m 에서 수평(H), 수직(V) 방향에 대한 음 속(V/SUB p/)과 감쇠계수 (q/SUB p/)가 실내분석방법으로 측정되었다. 채취된 시추퇴 적물이 길이는 약 250 m 이었으며, 측정 음원은 중심주파수 500 m 의 초음파 변환기 (ultrasonic p-wave transducer)가 사용되었다. 1,480~1,500 m/sec 정도의 변화를 보 이는 V/SUB p/의 비동방성 (A/SUB p/)은 $\pm$1.0% 이내로써, 수평 또는 수직 그 어느 쪽 이 빠르다고 판단하기는 어렵다. 이는 시료의 대부분이 균질 (homogeneous) 한 니질퇴 적상이며, 심한 생물교란 (bioturbation)과 함께 높은 공극율(85% 이상)에 따른 다량 의 해수 함유에 기인하는 것으로 판단된다. Q/SUB p/의 분포범위는 5~10 정도이며 전 반적으로 퇴적물 하부로 내려갈수록 감소하는 경향은 탄산염 (CaC0$_3$)과 유기물 함량 의 증가와 함께 silt가 증가하고 clay가 감소하는 퇴적물 입도 (texture)의 변화로 해 석된다. 그러나 화산재(volcanic ash)가 나타나는 최하부층에서는 14.9 의 높은 Q/SUB PH/값도 보이고 있다. V/SUB PH/와 Q/SUB PH/의 역상관관계는 퇴적물 물성변화 뿐만 아니라 높은 함수율로 인한 해수특성(높은 Q/SUB p/, 낮은 V/SUB p/)의 영향도 크게 작용하고 있음을 시사한다.

• 아태비즈니스연구
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• 제14권4호
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• pp.319-330
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• 2023

Purpose - The purpose of this paper is to examine the connectedness between categorical economic policy uncertainty (monetary, fiscal, trade and foreign exchange policy uncertainty) indexes and option-implied volatility index in Korea, Japan and the US. Design/methodology/approach - This paper employs the Diebold-Ylmaz (2012) model based on a VAR and generalized forecast error variance decomposition. This paper also conducts regression analyses to investigate whether the volatility indexes are explained by categorical policy uncertainty indexes. Findings - First, we find the total connectedness is stronger in Korea and Japan relative to the US. Second, monetary, fiscal, and foreign exchange policy uncertainty indexes are connected to each other but trade policy uncertainty index is not. Third, the volatility index in Japan and the US is mainly associated with monetary policy uncertainty while the volatility index in Korea is explained by fiscal policy uncertainty index. Research implications or Originality - To our knowledge, this is the first study to investigate the connectedness among categorical policy uncertainty indexes and the volatility index in Korea, Japan, and the US. The empirical results on the connectedness suggest that transparent policy and communication with the market in one type of policy would reduce the uncertainty in other policies.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2008년 영문 학술대회
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• pp.109-114
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• 2008

This paper presents the development status of a subscale precooled turbojet engine "S-engine" for the hypersonic cruiser and space place. S-engine employs the precooled-cycle using liquid hydrogen as fuel and coolant. It has $23cm{\times}23cm$ of rectangular cross section, 2.6 m of the overall length and about 100 kg of the target weight employing composite materials for a variable-geometry rectangular air-intake and nozzle. The design thrust and specific impulse at sea-level-static(SLS) are 1.2 kN and 2,000 sec respectively. After the system design and component tests, a prototype engine made of metal was manufactured and provided for the system firing test using gaseous hydrogen in March 2007. The core engine performance could be verified in this test. The second firing test using liquid hydrogen was conducted in October 2007. The engine, fuel supplying system and control system for the next flight test were used in this test. We verified the engine start-up sequence, compressor-turbine matching and performance of system and components. A flight test of S-engine is to be conducted by the Balloon-based Operation Vehicle(BOV) at Taiki town in Hokkaido in October 2008. The vehicle is about 5 m in length, 0.55 m in diameter and 500 kg in weight. The vehicle is dropped from an altitude of 40 km by a high-altitude observation balloon. After 40 second free-fall, the vehicle pulls up and S-engine operates for 60 seconds up to Mach 2. High altitude tests of the engine components corresponding to the BOV flight condition are also conducted.

• 한국환경과학회지
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• 제22권10호
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• pp.1363-1371
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• 2013

In this study, we estimate the interannual spatial and temporal distributions of fishing grounds at night in the East Sea based on satellite and in-situ data. We observe that the $15^{\circ}C$ thermal front moves in the north-south direction according to the movement of the warm water (above $18^{\circ}C$) in the Tsushima Warm Current (TWC) area, forcing the cold water area (below $10^{\circ}C$) to either expand or shrink. The interannual variations of sea surface temperature (SST) in winter represented by the indicator SST of $6^{\circ}C$ are consistent with the east-west zonal areas in the central East Sea which represented over $1^{\circ}C$ standard deviation of SST in February during 1990-2000. Annual SST in the fishing grounds of common squid fishing vessels, observed both by fishing vessels and satellites range from 9-$22^{\circ}C$, with the satellite-observed data having a larger range than the fishing vessel-based ones. The interannual distributions of the common squid fishing grounds in the East Sea are mostly concentrated in the TWC area in the southwestern part of the East Sea and in the coast of southern Honshu and Hokkaido in Japan. The interannual distributions of the nighttime fishing vessels are consistent with the catches investigated from the fishing vessel.

• Ocean and Polar Research
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• 제38권4호
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• pp.259-270
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• 2016

Sea Surface Salinity (SSS) observations from the Aquarius satellite in the East Sea show large systematic biases mainly caused by the surrounding lands and Radio Frequency Interferences (RFI) along the descending orbits on which the satellite travels from the Asian continent to the East Sea. To develop a technique for correcting the systematic biases unique to the East Sea, the least square regression between in situ observations of salinity and the reanalyzed salinities by HYCOM is first performed. Then monthly mean reanalyzed salinities fitted to the in situ salinities are compared with monthly mean Aquarius salinities to calculate mean biases in $1^{\circ}{\times}1^{\circ}$ boxes. Mean biases in winter (December-March) are found to be considerably larger than those in other seasons possibly caused by the inadequate correction of surface roughness in the sea surrounded by the land, and thus the mean bias corrections are performed using two bias tables. Large negative biases are found in the area near the coast of Japan and in the areas with islands. In the northern East Sea, data sets using the ascending orbit only (SCIA) are chosen for correction because of large RFI errors on the descending orbit (SCID). Resulting mean biases between the reanalysis salinities fitted to in situ observations and the bias corrected Aquarius salinities are less than 0.2 psu in all areas. The corrected mean salinity distributions in March and September demonstrate marked improvements when compared with mean salinities from the World Ocean Atlas (WOA [2005-2012]). In September, salinity distributions based on the corrected Aquarius and on the WOA (2005-2012) show similar distributions of Changjiang Diluted Water (CDW) in the East Sea.

• 한국전자거래학회:학술대회논문집
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• 한국전자거래학회 2003년도 종합학술대회 논문집
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• pp.197-203
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• 2003

The purpose of the study is to develop an integrated knowledge structuring system for the domain of engineering, in which ontology-based literature mining, knowledge acquisition, knowledge integration, and knowledge retrieval are combined using XML-based tag information and ontology management. The system supports combining different types of databases (papers and patents, technologies and innovations) and retrieving different types of knowledge simultaneously. The main objective of the system is to facilitate knowledge acquisition and knowledge retrieval from documents through an ontology-based dynamic similarity calculation and a visualization of automatically structured knowledge. Through experimentations we conducted using 100,000 words economic documents reported in the "Go！ Japan" project for analyzing Japanese industrial situation, and 100,000 words molecular biology Papers, we show the system is Practical enough for accelerating knowledge acquisition and knowledge discovery from the information sea.