• Journal of Navigation and Port Research
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• v.35 no.7
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• pp.575-580
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• 2011

It is important to understand the trajectory of structure in launching process because of the short time of launching process may result in unexpected accidents or damage to structures. The high risk of structural failure is not avoidable without the fully comprehension of changing forces in launching procedure. The commercial software can evaluate the motion of launching event in calm water condition but there is the limitation of research application because of the programmed commercial software. The launching process of the spar hull is suggested with stage concept that is divided into 10 stages in time domain. A force equilibrium diagram is derived for each stage where the changes of force vector and motion characteristics take place. In particular, the effects of changes in buoyancy and drag force due to the progressive submergence of the spar hull are taken into account by means of a touch length concept. The results contained in this paper provide the valuable information of the trajectory motion evaluation with suggested methods in spar launching process with sliding barge. Furthermore, the presented stage concept and touch length concept will provide basic knowledge for understanding launching process and help to develop further research area for launching analysis.

• Proceedings of the IEEK Conference
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• 1998.06a
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• pp.177-180
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• 1998

In high frequency environment such as microcell, it is requried to adopt a new method different from the empirical channel modeling applied in macrocell. In this thesis, measurement for residential area in Sinrimdong and the result of the simulation are compared and analyzed. Simulation technique utilizes 3D ray launching method to consider some factors which were not included in the ray tracing method. Propagation environment in the urban area shows the typical channel characterisitics of the propagation environment. Using 3D ray launching method, pathloss of the wave and delay characteristics of the signal with respect to the height of the transmitter is researched. If the transmitter is located on the top of the building, radiowave experiences diffraction on the rooftop and it influences the total received signal strength.

• Journal of the Korean Society for Precision Engineering
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• v.14 no.4
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• pp.22-29
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• 1997

This paper presents results on dynamic analysis of the missile initial motion arising from the missile detent force. Using ADAMS (Automatic Dynamic Analysis of Mechanical Syatem) software, a non- linear46-DOF (Degree of Freedom) model is developed for the launcher system including missile and lunch tube contact problem. From the dynamic analysis, it is found that initial angular velocity of the missile incre- ases when the missile detent force increases and also when rocket exhaust plume is taken into account. To achieve the missile launching stability, it needs to reduce the missile initial detent force and exhaust plume area of the lancher. Results of the dynamic analysis on the system natural frequency agree well with those obtained from experimental modal tests. The overall results suggest that the proposed method is a useful tool for prediction of initial missile stability as well as design of the missile launcher system.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1996.11a
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• pp.1017-1022
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• 1996

This paper presents results of dynamic analysis of the missile initial motion arising from the missile detent force. Using ADAMS (Automatic Dynamic Analysis of Mechanical System) software, a non-linear 46-DOF (Degree of Freedom) model is developed for the launcher system including missile and launch tube contact problem. From the dynamic analysis, it is found that initial angular velocity of the missile increases when the missile detent force increases (more than 18 g) and also rocket exhaust plume is taken into account. To achieve the missile launching s ability, it needs to reduce the missile initial detent force and exhaust plume area of the launcher. Results of the dynamic analysis on the system natural frequency agree well with those obtained from experimental modal tests. The overall results suggest that the proposed method is a useful tool for prediction of initial missile stability as well as d :sign of the missile launcher system.

• Journal of Space Technology and Applications
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• v.2 no.2
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• pp.146-168
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• 2022

Witnessing current military conflicts in South China Sea and Eastern Europe, most defense analysts evaluate one of the most serious security threat toward the US is coming from the superpower competitions with Russia and China. The main means for such super power hegemonic competitions is military power and space power is a key enabler to maximize the efficiency and effectiveness of military employment. Reflecting above circumstances, the space hegemonic competition between the Unites States and China is spreading into all aspects of national powers. Under such an environment, R.O.K needs to significantly develop national space power to preserve life and assets of people in space. On the other hand, the R.O.K has a lot of limitations in launching space assets into orbits by land-based space rockets due to its geographic locations. The limitation of rocket launching direction, the failure to secure a significant area enough to secure safety and the limitation to secure open area enough to build associated facilities are among them. On this paper, I will suggest the need to build the 2nd space rocket launching site after analyzing a lot of short-falls the current 'Naro' space center face, compared to those of advanced space powers around the world.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2006.05a
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• pp.398-404
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• 2006

Recently in Korea, rocket technology is being taken a wide scope as government planning to build Oeinaro-do space center and to select First Korean astronaut. But compared to development in USA, there is a lack of safety rules in amateur rocket. So it is very essential to meet some powerful legal safety rules for keeping pace with increasing popularization of rocket technology. Herein we discuss, in the field of rocket design, making, launching and collecting stage with considering the rules of IRR, NURA and NAR-HIAA.

• Journal of Ocean Engineering and Technology
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• v.27 no.6
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• pp.43-55
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• 2013

In general, huge caissons for breakwaters have been constructed on land or a floating dock. In the case of the construction on a floating dock, a 4 step installation procedure is involved: i) construction on a floating dock, ii) transportation by the floating dock to an area near the target sea, iii) launching from the floating dock, and iv) transference by tug-boats to the installation site. It is especially important to pay attention to the dynamic stability of the floating dock against the conditions in the sea during steps i) and iii). In this paper, the static and dynamic stabilities of a caisson on a floating dock are evaluated based on IMO rules during the construction and launching of the caisson on a floating dock by using independent commercial S/Ws such as NAPA, WAMIT, and CHARM3D.

• Journal of Fashion Business
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• v.13 no.4
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• pp.1-20
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• 2009

The main investigation of this thesis is about the comparative analysis of the fashion style preferences in the ages of 20-30 women, according to the style, by researching the area of Dalian and Seoul, represented as outstanding fashion cities in north eastern area. Both taking pictures and recording camcoders were performed at the famous fashion street in Seoul and Dalian. The period of investigation was from 24th of July to 2nd of August 2008. The result of research are as follows. Generally, the casual style was predominant in both area. The jean casual in Seoul was somewhat tidy and conservative, while that in Dalian showed the tendency of boldly exposed their body. In terms of easy casual, T-shirts and mini-tight skirt were preferred in Seoul, while T-shirts and midi-flare skirt was popular in Dalian. In Seoul, the blouse and mini skirt were in vogue, while one-piece dress, blouse and 5/7/9 length pants were prevalent in Dalian, in case of romantic style. The sports casual was relatively low in frequency in both areas, however, it was relatively more popular in Dalian than in Seoul. The frequency of classic style was similar in both areas. The T-shirts/blouse and Chanel-line skirt were preferred in Seoul, while the combination of jacket/shirts and full-length straight pants were preferred in Dalian. The one-piece dress was predominant in feminine style, the combination of mini one-piece dress and shoulder bag prevalent in Seoul, while the combination of Chanel-line one-piece dress designed as boldly exposed body was popular in Dalian, which shows the tendency of sexy, feminine style. The clear contrast or differences of street styles in Seoul and Dalian would become evident by this research. The continuous investigations into the various regions of China would be expected as an important measure for the successful launching into the Chinese fashion market.

• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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• 2004.11a
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• pp.45-50
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• 2004

The method of caisson typed bridge-foundation fabrication and installation applied in Ul-san newport breakwater project is throughly carried out to compact QRR mound vibro-hammer step by step to minimize settlement through stability check. Floating Dock was mobilized for caisson fabrication due to limited site area. fabricated caisson on the Floating Dock was towed to the deeper area of 8m water depth to be launched, and Floating Crane assisted launching and installation work of the caisson. finally water filling was done followed by surveying work to permanent installation.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.36 no.11
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• pp.1473-1478
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• 2012

This paper presents the development of a fracture-type protector for carrying a reconnaissance robot to a remote target area. Instead of a conventional unlocking mechanism, a separation method based on the fracture of assembled parts was implemented in the proposed lightweight protector in order to improve the feasibility for a real battlefield. Simulations using the finite element model of the protector and the robot were performed to verify the fracture under the given loading conditions, and shock experiments using a drop table were performed to calculate shock transmittance through the protector to the robot. Several field tests for a 100-m flight proved that the proposed scenario (launching, flying, landing, and separation) was achieved successfully.