• Journal of Life Science
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• v.17 no.8 s.88
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• pp.1068-1074
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• 2007

Parvalbumin occurs in various types of cells in the retina. We previously reported parvalbumin distribution in the inner nuclear layer of bat retina. In the present study, we identified the parvalbumin-immunoreactive neurons in the ganglion cell layer of the retina of a bat, Rhinolophus ferrumequinum, and investigated the distribution pattern of the labeled neurons. Parvalbumin immunoreactivity was found in numerous cell bodies in the ganglion cell layer. Quantitative analysis showed that these cells had medium to large-sized somas. The soma diameter of the parvalbumin-immunoreactive cells in the ganglion cell layer ranged from 12.35 to 19.12 ${\mu}m$ (n=166). As the fibers in the nerve fiber layer were also stained, the majority of parvalbumin-immunoreactive cells in the ganglion cell layer should be medium to large-sized retinal ganglion cells. The mean nearest neighbor distance of the parvalbumin-immunoreactive cells in the ganglion cell layer of the bat retina ranged from 59.57 to 62.45 ${\mu}m$ and the average regularity index was 2.95 ${\pm}$ 0.3 (n=4). The present results demonstrate that parvalbu-min is expressed in medium to large-sized retinal ganglion cells in bat retina, and they have a well-or-ganized distributional pattern with regular mosaics. These results should be important as they are applicable to a better understanding of the unsolved issue of a bat vision. This data will help to provide fundamental knowledge for the better understanding of the unique behavioral aspects of bat flight maneuverability.

• The Journal of the Korea Contents Association
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• v.8 no.5
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• pp.246-259
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• 2008

This study was to minimize the trial and error in the primary step of the C4I system(ATCIS) of the each army corps on the front line, and test the economy and efficiency was tested by reviewing related papers and the system characteristics of other countries. The relationship was researched by analyzing the collected survey data and survey data related to the user's requirement level such as the army standards, that is, commonality, timeliness, simplification, automaticity, field availability and viability, multi-stage security and interoperability, unification. The result showed that the C4I system was efficiently operated through the system reliability for the specification of the system and operation manual, maneuverability and security, adaptability of the war field and system support and management, and good education and training about system operation, and less system maintenance and supplementary element. As a result, the development plan confirmed that the continuous operator education and the construction of the maintenance, and the upgrade digitalization(C4ISR+D) with the korean characteristics based on IT of network systems, and system development of the measurement model of the operator performance must be continuously supplemented in the near future.

• Strategy21
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• s.44
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• pp.213-253
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• 2018

The Russo-Japanese War(1904-1905) in the early 20th century greatly influenced the international politics in Northeast Asia and the destiny of both countries. There are many studies on the cause of the outbreak and its effect on the Korean peninsula. The victory and defeat of the battle of Tsushima also the subject of research by renowned scholars and navy officers. Many previous studies have analyzed the process of engagement. However, There was a lack of research that analyzed at the tactical level of naval commanders. Therefore, this study tries to review the battle of Tsushima in terms of tactical level, that is formation, maneuvering, damage control. Naval operations at sea with many variables are not always done as planned. The intuitive judgement and readiness have had a decisive impact on victory and defeat. The analysis of the naval warfare on the basis of formation, maneuvering, and damage control makes the cause of the win more clearly. The conclusion of the this study can be summarized in five ways. First, victory would be achieved through the suppression of the beginning. The destiny of the Tsushima battle was determined by an 1 hour after first firing. The Japanese fleet caught fire by paralyzing the command and control capabilities of the Russian fleet. Second, the Japanese fleet's power was superior to the Russian fleet. In general, Japan and Russia had similar powers, and Admiral Togo's "T crossing tactics" decisively contributed the victory. However, when compared to the weapon system level, formation and maneuvering, Japan was much more dominant. Third, people realized that one side to be annihilated in the battle between similar powers after the Tsushima battle. The common perception before the Battle of Tsushima was that the battle ship would not sunken, and that the result of wiping out was difficult. However, there is s time for one sided victory and defeat depending on the early suppression nad the destruction of the command and control ability. Fourth, it is the importance of damage control ability. The main cause of the Russian fleet's loss of command and control ability was thick smoke from fire, and maneuverability was greatly deteriorated due to coal overload. In this way, importance is still valid after more than 100 tears. Fifth, the area of uncertainty. In the navy battles, one or two shots of clear firing in the beginning and small misconception and minor mistakes decide win or loss. Ultimately, this area of fortune can be linked to mindset of the commander. I hope this research will be help to naval researchers and naval commanders at the sea.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.2
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• pp.821-828
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• 2011

This paper developed the algorithm for improving the performance the auto pilot in the autonomous vehicle system consisting of the Track keeping control, the Automatic steering, and the Automatic mooring control. The automatic steering is the control device that could save the voyage distance and cost of fuel by reducing the unnecessary burden of driving due to the continuous artificial navigation, and avoiding the route deviation. During the step of the ship autonomic navigation control, since the wind power or the tidal force could make the ship deviate from the fixed course, the automatic steering calculates the difference between actual sailing line and the set course to keep the ship sailing in the vicinity of intended course. first, we could get the transfer function for the modeling of ship according to the Nomoto model. Considering the maneuverability, we propose it as linear model with only 4 degree of freedoms to present the heading angle response to the input of rudder angle. In this paper, the model of ship is derived from the simplified Nomoto model. Since the proposed model considers the maximum angle and rudder rate of the ship auto pilot and also designs the Fuzzy controller based on existing PID controller, the performance of the steering machine is well improved.

• Journal of the Korean Society of Marine Environment & Safety
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• v.26 no.7
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• pp.922-930
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• 2020

Marine accidents involving fishing boats, caused by a loss of stability, have been increasing over the last decade. One of the main reasons for these accidents is a sudden wind attacks. In this regard, the wind loads acting on the ship hull need to be estimated accurately for safety assessments of the motion and maneuverability of the ship. Therefore, this study aims to develop a computational model for the inlet boundary condition and to numerically estimate the wind load acting on a fishing boat. In particular, wind loads acting on a fishing boat at the wind speed profile boundary condition were compared with the numerical results obtained under uniform wind speed. The wind loads were estimated at intervals of 15° over the range of 0° to 180°, and i.e., a total of 13 cases. Furthermore, a numerical mesh model was developed based on the results of the mesh dependency test. The numerical analysis was performed using the RANS-based commercial solver STAR-CCM+ (ver. 13.06) with the k-ω turbulent model in the steady state. The wind loads for surge, sway, and heave motions were reduced by 39.5 %, 41.6 %, and 46.1 % and roll, pitch, and yaw motions were 48.2 %, 50.6 %, and 36.5 %, respectively, as compared with the values under uniform wind speed. It was confirmed that the developed inlet boundary condition describing the wind speed gradient with respect to height features higher accuracy than the boundary condition of uniform wind speed. The insights obtained in this study can be useful for the development of a numerical computation method for ships.