• Journal of Advanced Marine Engineering and Technology
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• v.39 no.4
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• pp.468-472
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• 2015

Recently, there has been increasing interest in the efficient use of energy due to policies related to the reduction of greenhouse gas. This paper suggests a highly efficient sea water cooling system for the load-dependent control of a seawater pump depending on the load, to improve energy efficiency of the warship. This study models the propulsion diesel engine and simulation reflecting the characteristics of the warship operation state that checked the performance of high efficiency sea water cooling system. The simulation results revealed the cooling system of high efficiency with energy savings of approximately 53% compared to the existing cooling systems. These results can be used to improve the performance of the cooling system of the warship propulsion diesel engine in the future.

• Journal of the Korea Society for Simulation
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• v.28 no.1
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• pp.67-79
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• 2019

A warship equipped with Multi Function Radar(MFR) performs operations by evaluating the degree of threats based on threats' symptom and allocating the resource of MFR to the corresponding threats. This study suggests a simulation-based approach and greedy algorithm in order to effectively allocate the resource of an MFR for warships, and compares these two approaches. As a detection probability function depending on the amount of allocations to each threat, we consider linear and exponential functions. Experimental results show that both the simulation-based approach and greedy algorithm allocate resource similarly to the randomly generated threats, and the greedy algorithm outperforms the simulation-based approach in terms of computational perspective. For a various cases of threats, we analyze the results of MFR resource allocation using the greedy algorithm.

• Korean Journal of Family Social Work
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• no.43
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• pp.87-110
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• 2014

This study is to understand the psychosocial experience in 'Cheonan Warship Incident Survivors'. The study question was how psychosocial experience in The Union of Family Bereaved by Cheonan Warship had been progressed. To answer this question 4 representers ofthe group and 2 reporters had been interviewed using a qualitative research method based on Phenomenology method. From this study the group's experience in had been revealed that they first crisis intervention are to identify and reinforce the strengths and coping skills of a one's family. Second, they gathered their opinion together and assigned the roles to the members, and then, requested what they want responding reasonably. The families' love, the representers' quick judgements and decisions, and the embarrassment of the military and media for the dead, who had been abandoned for long and decayed under the cold ocean, made the national support and respectful treatment possible for the dead and the family. The results of study will be applicable for individuals and groups, who need social work service as an empowerment intervention approach and crisis intervention are to identify and reinforce the strengths and coping skills of a one's family. The social worker's ability to anticipate, understand, and give therapeutic direction to the crisis reaction and the concerns of family members helps to bring around a successful crisis resolution. It is clear to us that wars, suicides, homicides in school settings, disaster and other events are providing unique challenges to social workers who are interested in learning more about the effects such events have on victims of traumatic events.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.25 no.8
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• pp.1103-1109
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• 2021

ECS is a control device so that the warship can perform the mission stably by controlling and monitoring the entire propulsion system. As the recent provisions of the warship, it's propelling system is complicated than past, as the demand performance and mission of the warships are diverse. In accordance with the complicated propulsion system configuration, the demand for automatic control function of the ECS is increasing for convenient and stable propulsion system control for convenient and stable. As a result, verification of ECS stability and reliability is required. In this paper, we develop an interlocking signal simulator for verifying ECS control logic and communication protocol for warship with CODLOG propulsion systems. The simulator developed was implemented to simulate a signal of gas turbine, propulsion motors, diesel generator and 11 kinds of auxiliary equipment. The reliability of ECS was verified through the ECS communication program and the I/O signal static test with the simulator.

• Proceedings of the Korean Society of Marine Engineers Conference
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• 2012.06a
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• pp.224-224
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• 2012

• Journal of the Korea Institute of Military Science and Technology
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• v.17 no.6
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• pp.733-743
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• 2014

Since the technology of anti-ship missiles has advanced rapidly, defending battleships from the threat of anti-ship missiles is a crucial factor for the survival of warships. In this paper, we analyze the performance of an anti-ship missile defense system whose name is Close-In-Weapon-System. We show the survival probability of a warship equipped with the Close-In-Weapon-System as the number of anti-ship missiles attacking the warship varies. Because of the complex and dynamic operational characteristics surrounding the Close-In-Weapon-System such as speed of missiles, different range of an individual weapon in the weapon system, and the continuous change of the kill probability of the missiles corresponding to the distance of missiles from ships, few work has been done for the performance of Close-In-Weapon-System. We present a model to incorporate all the dynamic characteristics of the system using absorbing Markov Chain. With our results, we expect commanders of warships equipped with Close-In-Weapon-System to be provided with more helpful information on how to deal with the anti-ship missiles.

• Journal of Computational Design and Engineering
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• v.1 no.4
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• pp.266-271
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• 2014

The survivability of the naval ship is the capability of a warship to avoid or withstand a hostile environment. The survivability of the naval ship assessed by three categories (susceptibility, vulnerability and recoverability). The magnitude of susceptibility of a warship encountering with threat is dependent upon the attributes of detection equipment and weapon system. In this paper, as a part of a naval ship's survivability analysis, an assessment process model for the ship's susceptibility analysis technique is developed. Naval ship's survivability emphasizing the susceptibility is assessed by the probability of detection, and the probability of hit. Considering the radar cross section (RCS), the assessment procedure for the susceptibility is described. It's emphasizing the simplified calculation model based on the probability density function for probability of hit. Assuming the probability of hit given a both single-hit and multiple-hit, the susceptibility is accessed for a RCS and the hit probability for a rectangular target is applied for a given threat.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.25 no.4
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• pp.426-433
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• 2014

The high-altitude electromagnetic pulse(HEMP) generated by a high-altitude nuclear explosion. This paper presents the comparison of electric field penetration in Bell laboratories and IEC 61000-2-9 standard when HEMP source penetrates through Naval Warship conducted coupling path and radiated coupling path. Also we analyze the effects of two kinds of coupling and propose Protective measures. Simulation results confirm IEC 61000-2-9 standard is more strict than the Bell Laboratories standard except for a lower frequency band, so we proposed IEC 61000-2-9 standard as a Naval HEMP standard. Finally, we offer the protective measures such as the shielding coating, Honeycomb ventilation, TVS in order to meet the military criteria.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2015.10a
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• pp.53-54
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• 2015

The maritime industry is expanding at an alarming rate and as such there is a perpetual need to improve situation awareness in the maritime environment using new and emerging technology. Tracking is one of the numerous ways of enhancing situation awareness by providing information that may be useful to the operator. The tracking system described herein comprises determining existing states of own ship, state prediction and state compensation caused by random noise. The purpose of this paper is to analyze the process of tracking and develop a tracking algorithm by using ${\alpha}-{\beta}-{\gamma}$ tracking filter under a random noise or irregular motion for use in a warship. The algorithm involves initializing the input parameters of position, velocity and course. The actual positions are then computed for each time interval. In addition, a weighted difference of the observed and predicted position at the nth observation is added to the predicted position to obtain the smoothed position. This estimation is subsequently employed to determine the predicted position at (n+1). The smoothed values, predicted values and the observed values are used to compute the twice distance root mean square (2drms) error as a measure of accuracy of the tracking module.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.68 no.1
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• pp.108-121
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• 2019

This paper presents the study results on the design of the correction filter to improve the azimuth error estimation of the high-speed guided missile launched from the warship after the transfer alignment. We theoretically proved that the transfer alignment performance is determined by the accuracy of the marine inertial navigation system and the observability of the attitude error state variable in the transfer alignment filter, and that most of navigation errors in high-speed guided missile are caused by azimuth error. In order to improve the azimuth estimation performance of the correction filter, the multiple adaptive estimation method and the adaptive filters adapting the measurement noise covariance or the process noise covariance are proposed. The azimuth estimation performance of the proposed adaptive filter and the existing Kalman filter are compared and analyzed each other for 8 different transfer alignment accuracy cases. As a result of comparison and analysis, it was confirmed that the adaptive filter adapting the process noise covariance has the best azimuth estimation performance. These results can be applied to the design of correction filters for high-speed guided missile.