• Proceedings of KOSOMES biannual meeting
• /
• 2017.04a
• /
• pp.84-84
• /
• 2017

• Journal of information and communication convergence engineering
• /
• v.15 no.4
• /
• pp.244-249
• /
• 2017

Wearable sensor-based gait analysis has been widely conducted to analyze various aspects of human ambulation abilities under the free-living condition. However, there have been few research efforts on using wearable sensors to analyze human walking on an unstable surface such as on a ship during a sea voyage. Since the motion of a ship on the unstable sea surface imposes significant differences in walking strategies, investigation is suggested to find better performing wearable sensor-based gait analysis algorithms on this unstable environment. This study aimed to compare two representative gait event algorithms including time domain and frequency domain analyses for detecting heel strike on an unstable platform. As results, although two methods did not miss any heel strike, the frequency domain analysis method perform better when comparing heel strike timing. The finding suggests that the frequency analysis is recommended to efficiently detect gait event in the unstable walking environment.

• Journal of Information Technology and Architecture
• /
• v.9 no.2
• /
• pp.143-154
• /
• 2012

With the realization of the importance of the NWI, iterated by the Cheonan Ship sink and the YP-Do shelling, this thesis separates the NWI from the peninsula, regarding it separate from the Korea Theater of Operations, and suggests the method to establish NCOE with consideration to the characteristics of separated theater as well as the current situation. Although the NWI holds strategic value, systematical NCOE of surveillance and reconnaissance system, command and control system, and precision strike system is not yet established. Pertaining to this issue, Architecting was utilized to identify improvement measures and of the identified improvement measures, improvement on the "strike on nK hardened artillery sites with K-9 Self-Propelled Artillery in correlations with theater ISR" shows greatly improved strike effects when conducting simulations based on the Operation-Plan Analysis Model. Such a method of NCOE establishment will serve as a standard model for military force building and operation execution system for separated theater operations such as the NWI.

• Strategy21
• /
• s.34
• /
• pp.178-206
• /
• 2014

The battlefield environment in the maritime has been changed by advanced IT technology, variation of naval warfare condition, and developed military science and technology. In addition, state-of-the-art surface combatants has become to multi-purpose battleship that is heavily armed in order to meet actively in composed future sea battlefield condition and perform multi-purpose missions as well as having capability of strategic strike. To maximize the combat strength and survivability of ship, it is not only possible for Zumwalt(DDG-1000) class combatant to conduct multi-purpose mission with advanced weapon system installation, innovative hull form and upper structure such as deckhouse, shipboard high-powered sensor, total ship computing environment, and integrated power control but it was designed so that can be installed with energy based weapon systems in immediate future. Zumwalt class combatant has been set a high value with enormous threatening surface battleship in the present, it seems to be expected that this ship will be restraint means during operation in the littoral. The advent of Zumwalt class battleship in the US Navy can be constructed as a powerful intention of naval strength building for preparing future warfare. It is required surface ship that can be perform multi-purpose mission when the trend of constructed surface combatants was analyzed. In addition, shipboard system has been continuously modernized to keep the optimized ship and maximize the survivability with high-powered detection and surveillance sensor as well as modularity of combat system to efficient operation.

• International Journal of Naval Architecture and Ocean Engineering
• /
• v.8 no.6
• /
• pp.563-576
• /
• 2016

The flight deck of an aircraft carrier is relatively vulnerable compared to its hull, as the damage of some subsystems on the flight deck may cause the carrier losing its operational capability. Therefore, this work aims to represent a simulative method for evaluating the resistance of the flight deck's operational capability in the condition that the aircraft carrier is together with its strike group and the enemy uses the anti-ship missiles with the cluster warheads to attack. In the simulations, the susceptibility of the carrier and the vulnerability of the aircraft guarantee resources are gained. Then, with the help of the closed queuing network, the residual sortie generation rate can be solved, which reflects the flight deck's residual operational capability. The results have proven that the flight deck is of strong resistance to these attacks while it is very sensitive to the loss of some key aircraft guarantee resources.

• Journal of Korea Ship Safrty Technology Authority
• /
• s.28
• /
• pp.4-18
• /
• 2010

자연 현상중의 하나인 낙뢰는 대기중에서 일어나는 뇌운과 보호대상 물체간의 방전현상으로 그 발생 빈도와 피해를 예측할 수 없으며, 국내에서 선박이 낙뢰로 인한 피해가 보고된 경우는 거의 없는 실정이지만 매년 정보화 통신장비 등의 보급확대와 더불어 낙뢰에 의한 피해가 증가할 것으로 판단되며 국내 대부분의 소형선박들은 낙뢰에 취약한 비금속 재질인 FRP선 또는 목선으로 건조되어 있어 낙뢰에 의한 사고에 취약한 현실이다. 본 연구는 근래에 무선설비 항해용구 등의 선박에 초소형의 집적회로를 사용하는 전자장비의 보급이 증대됨에 따라 낙뢰가 선박에 입사하였더라도 부적절한 피뢰설비 때문에 과도전압이 발생하여 제어 감시설비 등을 파손시키는 직 간접적인 피해를 감소시키기 위해서 비금속제 소형 선박에 적합한 피뢰시스템을 제시하여 낙뢰에 의한 피해의 최소화를 위한 대책 마련을 목적으로 수행하였다. KS, ISO, NFPA 및 각 국의 피뢰설비기준에서는 비금속제 선박의 피뢰설비 규정을 제시하고 있으나 국내 규정에서는 비금속제 소형선박에 관한 피뢰설비의 설치기준이 마련되어 있지 않은 실정이므로 이번 연구결과를 통해서 비금속제 소형 선박의 피뢰설비에 대한 합리적인 피뢰설비 설치기준을 설정하는 자료로 활용할 수 있을 것이다.

• Journal of Navigation and Port Research
• /
• v.29 no.4
• /
• pp.299-304
• /
• 2005

A simulation system is needed to train students and mariners in order that they can take suitable actions to evade typhoon's strike promptly and sufficiently. In order to make such kind of system, three kinds of models about the typhoon are necessary, typhoon prediction model to generate typhoon's track, wind & wave-field model to make sea conditions around the typhoon and evaluation model of trainee's action whether their actions were suitable or not during simulation. We have developed the prediction and wind & wave-field models of typhoon, but the evaluation model has not been developed yet. In this paper, after making a method for evaluating trainee's actions by seakeeping performance, we propose an typhoon avoidance simulation system for training mariners so that they can promote their abilities to evade the typhoons at sea.

• Geophysics and Geophysical Exploration
• /
• v.8 no.1
• /
• pp.50-58
• /
• 2005

Recently, the imaging of geological structures beneath water-covered areas has been in great demand because of numerous tunnel and bridge construction projects on river or lake sites. An electrical resistivity survey can be effective in such a situation because it provides a subsurface image of faults or weak zones beneath the water layer. Even though conventional resistivity surveys in water-covered areas, in which electrodes are installed on the water bottom, do give high-resolution subsurface images, much time and effort is required to install electrodes. Therefore, an easier and more convenient method is sought to find the strike direction of the main zones of weakness, especially for reconnaissance surveys. In this paper, we investigate the applicability of the streamer resistivity survey method, which uses electrodes in a streamer cable towed by ship or boat, for delineating a fault zone. We do this through numerical experiments with models of water-covered areas. We demonstrate that the fault zone can be imaged, not only by installing electrodes on the water bottom, but also by using floating electrodes, when the depth of water is less than twice the electrode spacing. In addition, we compare the signal-to-noise ratio and resolving power of four kinds of electrode arrays that can be adapted to the streamer resistivity method. Following this numerical study, we carried out both conventional and streamer resistivity surveys for the planned tunnel construction site located at the Han River in Seoul, Korea. To obtain high-resolution resistivity images we used the conventional method, and installed electrodes on the water bottom along the planned route of the tunnel beneath the river. Applying a two-dimensional inversion scheme to the measured data, we found three distinctive low-resistivity anomalies, which we interpreted as associated with fault zones. To determine the strike direction of these three fault zones, we used the quick and convenient streamer resistivity.