• Journal of the Korean Society of Marine Environment & Safety
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• v.17 no.4
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• pp.301-306
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• 2011

This study was determined to analysis the characteristics of water mass in the Bottol Bada, Yeosu in August, 2010 based on the data from the distribution of water temperature and salinity. Sampling was carried out a total of three times (i.e. July 29, August 13, and August 30, 2010) and performed at three stations. Observation was done during the period of time 10:00-15:00, indicating the decreasing tidal height and turn of tide. In July 29, thermocline was found at 4 m in St. 1, but the stratification did not observe in August 13 and August 30. The remarkable water temperature between surface and bottom was found in St. 2 and St. 3, whereas St. 1 did not find. A particular finding during this study showed a cold water mass at bottom layer from St. 2 and St. 3, which was first occurred in July 29 and persisted in August 30 without any of destruction. Water temperature had a remarkable fluctuation between surface and bottom, whereas salinity had a unique in St. 1. St. 2 and St. 3 showed the increasing salinity according to water depth in August 13 and August 30. Transparency had considerable fluctuations in St. 1 and St. 3 depending to sampling date, but St. 2 did not fluctuate. Consequently, the Bottol Bada had a significantly different water mass between inner and outer waters. Furthermore, strong irradiance and weak wind play an important role in developing the stratification between surface and bottom, in particular the introduction of offshore waters contribute to highly developing the stratification in the Bottol Bada during the period of August in 2010.

• Journal of Fisheries and Marine Sciences Education
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• v.10 no.2
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• pp.211-225
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• 1998

A field experiment was carried out for fishes on entering time to a set-net, swimming speed, current speed and direction at the Dongbok-Ri coast on Cheju Island. The results of the experiment are as follows : 1. The observation results from 07:00 to 18:00 showed that coral fish, flying fish, horse mackerel, drub mackerel and striped mullet enter the set-net from 07:00 to 14:00 mainly. 2. From the result of analyzing relationships between entering time and tide, coral fish and horse mackerel tend to enter the set-net on turn of tidal current and ebb respectively. 3. The leaving rates of coral fish, flying fish, drub mackerel, and striped mullet from the set-net were 13%, 45%, 50%, and 100%, respectively but all horse mackerel remained in the net. 4. The swimming speed of coral fish, flying fish, horse mackerel and drub mackerel are 5~25cm/sec, 20~50cm/sec, 15~45cm/sec and 10~30cm/sec, respectively and their dominant speeds are 10~15cm/sec(55%), 30~35cm/sec(30%), 30~40cm/sec(60%), and 15~20cm/sec(60%), respectively.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.41 no.1
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• pp.17-26
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• 2005

There are several problems in the commercial pound net in the heavy tide ; the breaking and loss of net, steeply variation of net shape and decreasing of fishing efficiency, etc. In order to solve these problems, we introduced method of added sinker used to coastal cultivating cage of Japan and investigated the possibility of application to the Korean pound net. The results are obtained as follows; 1. In case of the upperward flow with fish court net, tension of the frame line was increased about 10${\sim}$25% than that of prototype according to the added sinker from 1.3gf to 5.2gf. The tension of A-type and B-type was similar to the case of the prototype, the tension of C-type and D-type was increased about 10${\sim}$15% than that of prototype. 2. The variation of deformed angle of fish court net was from 0$^{\circ}$ to 70$^{\circ}$ and that of the slope net was from 0$^{\circ}$ to 64$^{\circ}$ and that of the second bag net was from 0$^{\circ}$ to 46$^{\circ}$ and the depth of the second bag net was increased about 10% when the added sinker was changed from 1.3gf to 5.2gf. The depth of the first bag net and the second bag net were decreased about 50% than that of initial depth. 3. For the deformed angle of fish court net according to the attached point of the added sinker, A-type and B-type were decreased about 25% and 10% than the prototype, respectively. C-type was similar to the case of the prototype and D-type was increased about 15% than that of the prototype. The depth of slope net became deep in turn of A-type, B-type, C-type and D-type. For the depth of the second bag net, A-type, B-type, C-type and D-type were increased about 10${\sim}$15% than that of prototype. The depth of the slope net was changed from 0$^{\circ}$ to 63$^{\circ}$ and that of the second bag net was changed from 0${\sim}$44$^{\circ}$ according to the increase of velocity. 4. The optimal weight of added sinker was about 2.6${\sim}$3.6gf and the optimal attached point of added sinker was the case of C-type and D-type.

• Journal of Life Science
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• v.15 no.2 s.69
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• pp.225-230
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• 2005

The aim of this study was to examine the fluctuation in phytoplankton assemblages with regarding to environmental conditions and nutrients, which were surveyed quarterly over the fours seasons (February, May, July, and October). In turn, an understanding of biological effects should provide insights into a wide range of initiated Cochlodinium blooms in Narodo. Sampling was carried out throughout 2001 on the coasts of Busan (St. 1), Yeosu (St. 2), Narodo (St. 3), Kohung (St. 4), and Kwangdo (St. 5). The maximum surface water temperature was recorded in July, and it ranged from 20 to $22^{\circ}C$. Salinity showed no great variation, which maintained itself in the range of 29-34 psu. The maximum surface salinity was recorded in February, which was about 34 psu. The chlorophyll $\alpha$ concentration of the surface water ranged from 0.01 to $1.3\;{\mu}g\;1^{-1}$. The concentrations of $NH_{4}-N $ were persistently high from February to October; in particular, the peak was observed at St. 1 in February and May (0.15 and $0.19\;{\mu}mol\;1^{-1}$, respectively), while it was detected at St. 2 in July and October (0.22 and $2.2\;{\mu}mol\;1^{-1}$ respectively). Similar trends to those for $NH_4-N $ were observed in the concentrations of $NO_{2}-N$ and $NO_{3}-N$. In contrast to nitrogen, a distinct peak of $NO_{4}-P$ at St. 3, 4, and 5 was observed throughout year $(0.01-0.1\;{\mu}mol\;1^{-1}$ except for October. At St. 1 encounter a peak of cell number of 30,000 and $13{\times}10^3$ cells $1^{-1}$, respectively, in July and October. During the period of this study, the majority of the taxa were diatoms. The dinoflagellates were rather abundant after February, in particular at St. 3, 4, and 5 which attained an abundance of $10\~20\%$without marked fluctuation during the period of this study. At St. 3, the highest average cell width, $178.11\;{\mu}m$, was recorded: the highest cell length, $337.72\;{\mu}m$, was measured in July. Consequently, dinoflagellates bloom in July at Narodo influenced by warm water current are not only associated with a desirable development of cell morphometric characteristics, but also with the health growth of C. polykrikoides. During the period of this study, warm water currents caused an increased water temperature in Narodo, but did not change the amount of nutrients.

• The Korean Journal of Air & Space Law and Policy
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• v.35 no.1
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• pp.153-180
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• 2020

This study is meaningful in finding out what legal and policy issues need to be improved in order to foster the aircraft industry, which is relatively underdeveloped compared to the fact that some heavy industries, such as the automobile industry and shipbuilding industry, have achieved a high level of production and technology globally. Korea's aircraft industry has been growing at a slower pace than other industries, largely due to the country's economic growth and the lack of a market structure to properly use variables such as the level of development in related industries, aircraft technology and demand for aircraft manufacturing. While most industries are privately led by the market structure of the competition system, heavy industries such as the aircraft industry generally grow under the market structure of the incomplete competition system, because only by securing huge initial investment costs, high technology, and sufficient demand, they can maintain minimum economic feasibility. The Korean aircraft industry was focused on developing and mass-producing military aircraft focusing on military demand, but it sought to turn the tide by signing the BASA (Bileral Aviation Safety Agreement) with the U.S. A preliminary feasibility study was conducted in 2010 to develop next-generation medium-sized aircraft, but was cancelled due to differences in position with Canada's Bombardier, which is subject to the concourse, and Korea Aerospace Industries (KAI) is pushing for the production of Bombardier's Q400 license on its own. Compared to the mid-to-large sized civil aircraft that are facing difficulties in development, KAI and KARI are successfully developing technologies to unmanned aerial vehicles and civil helicopters. In addition, the unmanned aerial vehicle sector is not yet suitable for manufacturers that have an exclusive global influence, so we believe that it is necessary to pursue government-led research and development projects with a focus on the areas of commercial helicopters and unmanned aerial vehicles in order to foster the aircraft industry in the future. In addition, since military aircraft such as KT-1 and T-50 are currently being exported smoothly, and it cannot be overlooked that the biggest demand for aircraft manufacturing in the Korea is the military, it is necessary to push forward national R&D projects and defense R&D program simultaneously to enable both civilian-military development. However, there are many differences between the two projects in the way they are implemented, the department in charge and the royalty system. Through this study, we learned about the technology ownership and implementation rights of national R&D projects and defense R&D programs, as well as the royalty system. In addition, problems with the system were identified and improvement measures were derived.