• Proceedings of the Korean Institute of Communication Sciences Conference
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• 2006.07a
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• pp.610-610
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• 2006

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.31 no.4
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• pp.350-361
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• 1995

For the Purpose of the measurement of drifting condition of the anchovy drift gill net, some experiments were carried out in M. S Seong-Yang at the near sea of Kampo harbor in Korean east sea from August to October 1994, by using three set of GPS equipped with her net. The main results obtained are as follows : 1) In fixed position by GPS at Taebyon, the radius of 95% probability and shifted distance from standard position were respectively 79.8m, 21.0m. 2) The mean values of PDOP and HDOP of GPS at Taebyon were respectively 3.5, 1.9 and the stability of the position by GPS at Taebyon was found to be very high. 3) In the fishing ground of the position from Lat. $35^{\circ}$ 41.5'N to $Lat^{\circ}$. 43.5', from Long. $129^{\circ}$ 32.0'E to Long. $129^{\circ}$ 32.5'E, the direction of the whole stretched drift gill net was $190^{\circ}$ and the direction of the whole casted net was $200^{\circ}$ when casting the net was finished. When whole net was found to be drifting into the direction of $170^{\circ}\;to\;180^{\circ}$, and the mean drifting speed of that was 0.82kt. 4) In the fishing ground of the position from Lat. $35^{\circ}$ 44.0'N to Lat. $35^{\circ}$ 45.2'N, from Long. $129^{\circ}$ 30.1'E to Long. $129^{\circ}$ 31.2'E, the direction of the whole stretched net was 20$^{\circ}$ and the direction of the whole stretched net was $20^{\circ}$ when casting the net was finished. When hauling the net, the direction of the spreaded net appeared from the North into the South and the whole net was found to be drifting into the direction of $210^{\circ}\;to\;220^{\circ}$, and the mean drifting speed of that was 0.75kt. 5) In the fishing ground of the positioning from Lat. $35^{\circ}$ 44.9'N to Lat. $35^{\circ}$ 46.0'N, Long. $129^{\circ}$ 33.0'E to Long. $129^{\circ}$ 34.0'E, the direction to the whole stretched net was $35^{\circ}$ and the direction of the whole casted net was $50^{\circ}$ when casting the net was finished. When hauling the net, the direction of the spreaded net appeared into the South from the East and the whole net was found to be drifting into the direction of $330^{\circ}\;to\;40^{\circ}$, and the mean drifting speed of the was 0.63kt.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.31 no.1
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• pp.54-62
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• 1995

In order to telemeter the behavior and distribution of fishes. the telesounder was manufactured and it was examined to verify its performance and effects in the gape nets with wings located around Gokunsan islands. Yellow Sea. on August 8. 18~19 and September 8~9, 1994. The behavior of fish entering the net was observed with the buoy station at sea which was installed at the entrance of the gape nets with wing and its echosignal was transmitted remotely to the base station on ship at distance of about 1 km away from the buoy station at sea. The fishes catched by the gape nets with wings were 12 species and Anchovy(Engraulis japonica), Beka squid(Loligo beka), Herring(Harengula zunasi) was 95% of total catches. The images of color display monitor at the base station on ship were very well coincident with the records of fish finder from the buoy station located at sea. When the current velocity was less than 0.6 kt and slight fluctuation, the fishes entered into the gape net were much more in comparision with over 1.0kt and heavy fluctuation, and then the average swimming depth was about 4 m. The catches per one hauling was about 10~30 kg and when the current velocity was too weak and the current direction did not coincident with the direction of net or the current velocity was too strong, the catches was a few. It is concluded that telesounder system is very useful for investigating the distribution and the swimming behavior of fishes entering in the gape nets with wings.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.42 no.3
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• pp.148-157
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• 2006

A model experiment, simulation test using personal computer and real sea trial fishing were carried out to investigate the basic efficiency of bottom trawl net which can be used in the sea mount of North West Pacific, and experimental values were analyzed as the values of full-scale bottom trawl net. Hydrodynamic resistance for the full-scale trawl net according to the Koyama equation was 2.1 times higher than that of simulation and 2.4 times higher than that of model experiment at the average towing velocity. At the 3.5kt's of towing speed, net width of the full-scale trawl net was 2.5% smaller than that of simulation and 8.2% larger than that of model experiment. On the fishing experiment of the full-scale trawl net for the 3.5kt's of average towing speed, average net height of A group(same direction with external force) was 423.5% higher than that of model experiment and 457.1% higher than that of simulation and that of B group(opposite direction with external force) were 283.8% and 306.3% higher than in case of model experiment and Simulation respectively. Net mouth of the full-scale trawl net was 338.1-504.6% higher than those of model experiment and simulation in A group, and 525.2-745.3% higher in B group.

• Proceedings of KOSOMES biannual meeting
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• 2007.11a
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• pp.91-95
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• 2007

It tries to develop a collect system for floating garbage flowed into the sea Based on the study on the characteristics of floating garbage in rainy season, it confirmed the structure and specification of each device and tested its performance on the sea It showed tint the collection device of this system could sweep more than 15 meters of sea area at a time when a ship moves with the efficiency of the spreading device. It means tint it is more efficient in collecting garbage than now in use garbage collecting ships. The water height of the net to which the garbage is finally input maintained more 50cm within the towing speed of 5kt. It indicates tint the garbage input performance is good The collect system of this research showed good performance collecting 200kg of garbage into the net for each test of collecting floating garbage.

• Bulletin of the Korean Chemical Society
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• v.27 no.10
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• pp.1557-1561
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• 2006

The use of chemically modified silica-salen$(NEt_2)_2$ was studied for the separation and concentration of the metal ions from an aqueous solution by a solid phase extraction. After the salen(NEt2)2 was synthesized, it was chemically bonded to silica gel by a diazonium coupling reaction. The adsorption capacities and binding constants were obtained with respect to Cu(II), Mn(II), Pb(II) and Zn(II) by a graphical method. Some experimental conditions were optimized for the determination of the trace elements. After the silica-salen(NEt2)2 was pulverized in a sample solution of which the pH was adjusted, the solution was stirred to pre-concentrate the metal ions. The metal ions adsorbed were desorbed with nitric acid solution. And the concentrated analytes were determined by a flame AAS. The method proposed here was so rarely influenced by a sample matrix that the procedure was applied to 3 types of water samples. The reproducible results of less than 10% RSD were obtained at the concentration level of ca. 100 ng/mL and the recoveries of 95-109% were obtained in the spiked samples in which given amounts of analytes were added.

• Bulletin of the Korean Chemical Society
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• v.29 no.5
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• pp.969-973
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• 2008

Solvent extraction using a Schiff-base, salen$(NEt_2)_2$, as a chelating agent has been conducted on several water samples to study the determination of trace Cu(II), Mn(II) and Zn(II). Experimental conditions for the formation and extraction of metal complexes were optimized with an aqueous solution similar in composition to the samples. The matrix difference between the sample and standard solutions was approximately matched, and the pH of each sample solution was adjusted to 9.5 with $NaHCO_3/NaOH$ buffer. The concentration of salen$(NEt_2)_2$ was $7.3\;{\times}\;10^{-3}$ mol/L, and the complexes were extracted into MIBK solvent followed by the measurement of AAS absorbance. The potential interference of concomitant ions was investigated, but no interference from alkaline and alkali earth ions was shown in this procedure. The given procedure is precise, as judged from the relative standard deviation of less than 5% for five measured data. The recovery of 93-103% shows that this method is quantitative for such trace metal analysis.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.42 no.3
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• pp.134-147
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• 2006

A model experiment using circulation water channel was carried out to investigate the dynamic characteristics of bottom trawl net which can be used in sea mount of North Pacific. Hydrodynamic resistance and shape variation according to the flow velocity and angle of hand rope transformation for net were measured, and experimental value was analyzed as the value of full-scale bottom trawl net. The results summarized are as follows; At the $30^{\circ}$ of angle of hand rope to net, hydrodynamic resistance varied from 0.5kgf to 2.68kgf as the flow velocity increased between 0.31m/s and 0.92m/s, and formula of hydrodynamic resistance for the model net was $F_m=3.04\;{\cdot}\;{\upsilon}^{1.53}$. At the fixed angle of hand rope, Net height was low and Net width was high according to the increase of flow velocity, and in addition, vertical opening was low and Net width was high by the increase of angle of hand rope at the fixed flow velocity. At the $30^{\circ}$ of angle of hand rope to net, net opening area was $0.214m^2$ as flow velocity was 0.61m/s, and formula of net opening area for the model net was $S_m=-0.22{\upsilon}+0.35$. At the $30^{\circ}$ of angle of hand rope to net, catch efficiency seemed to be highest as $0.319m^3/s$ of filtering volume at the 0.76m/s(51kt's) of flow velocity. Shape variation of net showed the gradual laminar transform for the variation of flow velocity but there needed some improvements due to the occurrence of shortening at the ahead of wing net.

• Nuclear Engineering and Technology
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• v.40 no.6
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• pp.517-526
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• 2008

The widespread concern regarding the management of spent fuel that mainly contributes to nuclear waste has led to the development of the sodium-cooled fast reactor (SFR) as one of the most promising future types of reactors at both national and international levels. Various reactor deployment scenarios with SFR introductions with different conversion ratios in the existing PWR-dominant nuclear fleet have been assessed to optimize the SFR deployment strategy to replace PWRs with the view toward a reduction in the level of spent fuel as well as efficient uranium utilization through its reuse in a closed fuel cycle. An efficient reactor deployment strategy with the SFR introduction starting in 2040 has been drawn based on an SFR deployment strategy in which burners are deployed prior to breakeven reactors to reduce the amount of PWR spent fuel substantially at the early deployment stage. The PWR spent fuel disposal is reduced in this way by 98% and the cumulative uranium demand for PWRs to 2100 is projected to be 445 ktU, implying a uranium savings of 115 ktU. The SFR mix ratio in the nuclear fleet near the year 2100 is estimated to be approximately 35-40%. PWRs will remain as a main power reactor type until 2100 and SFRs will support waste minimization and fuel utilization.

• Nuclear Engineering and Technology
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• v.46 no.1
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• pp.63-72
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• 2014

Pyroprocess technology has been considered as a fuel cycle option to solve the spent fuel accumulation problems in Korea. The Korea Atomic Energy Research Institute has been studying pyroprocess technology, and the conceptual design of an engineering-scale pyroprocess facility, called the Advanced Fuel Cycle (AFC) facility, has been performed on the basis of a 10tHM throughput per year. In this paper, the concept of the AFC facility was introduced, and its safety evaluations were performed. For the safety evaluations, anticipated accident events were selected, and environmental safety analyses were conducted for the safety of the public and workers. In addition, basic radiation shielding safety analyses and criticality safety analyses were conducted. These preliminary safety studies will be used to specify the concept of safety systems for pyroprocess facilities, and to establish safety design policies and advance more definite safety designs.