• Journal of the Korean Society for Industrial and Applied Mathematics
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• v.19 no.3
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• pp.253-270
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• 2015

Two major simultaneous attack strategies have been introduced, as one of cooperative attack of multiple missiles. One strategy is an undesignated time attack, in which the missiles communicate among themselves to synchronize the arrival times by reducing the mutual differences of times-to-go of multiple missiles during the homing. The other is a designated time attack, in which a common impact time is commanded to all members in advance, and thereafter each missile tries to home on the target on time independently. For this individual homing, Impact-Time-Control Guidance (ITCG) law is required. After introducing cooperative proportional navigation (CPN) for the first strategy, this article presents a new closed-form ITCG guidance solution for the second strategy. It is based on the linear formulation, employing base trajectories driven by PNG with various navigation constants. Nonlinear simulation of several engagement situations demonstrates the performance and feasibility of the proposed ITCG law.

• The Korean Journal of Emergency Medical Services
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• v.19 no.3
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• pp.33-49
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• 2015

Purpose: This study aimed to investigate the work and job satisfaction of military emergency medical technicians (EMTs). Methods: We selected 122 military EMTs who participated in the refresher education in 2012. This study was conducted from November 12 to December 21, 2012. Results: The most frequent duties of military EMTs were scene assessment, cardiopulmonary resuscitation, surgical treatment, prehospital first-aid, transfer to the hospital, education, and call response. The air force and navy EMTs had better performance than the army EMTs. As for job satisfaction, the work itself ranked highest, whereas payment ranked lowest. Conclusion: The scope of the work of the military EMTs varied in the 14 fields of work but should be considered for further evaluation. In order to increase the job satisfaction of EMTs, their work conditions should be improved such as through salary increase and extra pay for those with professional certificates.

• Structural Engineering and Mechanics
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• v.19 no.2
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• pp.153-172
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• 2005

A new load/displacement parameter method is proposed for the simultaneous control of applied loads and structural displacements at one or more points. The procedure is based on a generalized Riks' method, which utilizes load/displacement parameters as scaling factors to analyze post-buckling phenomena including snap-through or snap-back. The convergence characteristics are improved by employing new relaxation factors through an incremental displacement parameter, particularly in a region that exhibits severe numerical instability. The improved performance is illustrated by means of a numerical example.

• International Journal of Air-Conditioning and Refrigeration
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• v.15 no.4
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• pp.182-190
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• 2007

Refrigeration and air-conditioning equipments are indispensable products in this civilized society. However, discharged refrigerants used in the equipments and exhausted carbon dioxide to drive the refrigeration and air-conditioning equipments are related to serious environmental problems and energy problems. Especially, the destroyed ozonosphere by the discharged refrigerants and the increased normal temperature by carbon dioxide and fluorocarbon refrigerants (green house gases) are sounded as serious global problems. For alleviating these problems, environmental-friendly refrigeration and air-conditioning equipments must be developed and will spread soon. To develop new equipment, a suitable refrigerant for each usage must be presented. In this paper, the current state of refrigerants was introduced. And, thermophysical properties of the refrigerants were introduced briefly. From the properties, the refrigerants and refrigeration cycles are promising to be used in the future, were proposed

• Journal of the Korea Society of Computer and Information
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• v.24 no.6
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• pp.11-19
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• 2019

In this paper, a new Scene-based Nonuniformity Correction (SBNUC) method is proposed by applying Image Roughness-like and Spatial Noise cost functions on deep neural network structure. The classic approaches for nonuniformity correction require generally plenty of sequential image data sets to acquire accurate image correction offset coefficients. The proposed method, however, is able to estimate offset from only a couple of images powered by the characteristic of deep neural network scheme. The real world SWIR image set is applied to verify the performance of proposed method and the result shows that image quality improvement of PSNR 70.3dB (maximum) is achieved. This is about 8.0dB more than the improved IRLMS algorithm which preliminarily requires precise image registration process on consecutive image frames.

• Journal of Energy Engineering
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• v.28 no.1
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• pp.30-36
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• 2019

The military has developed and operated a variety of military vehicles. Among them, medium tactical vehicles are developed as vehicles suitable for transporting troops, replacing existing military trucks, which have a significant impact on infantry forces' combat capability. Applying technology to increase fuel efficiency to these critical weapons systems, medium tactical vehicles, increases the distance range, which can reduce effective operational performance and oil costs. In this study, a measure was taken to improve the distance range of Medium Tactical Vehicles by applying an oil temperature control strategy to increase fuel efficiency.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2019.06a
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• pp.249-251
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• 2019

본 논문에서는 CNN 기반 스테그아날리스 방법을 이용하여 입력 영상에 비밀 메시지가 삽입되었는지를 판별하고, 비밀 메시지가 삽입되었을 경우 WOW 와 UNIWARD 방법 중에 어떤 방법으로 삽입되었는지를 분류하고자 한다. 이를 위해 입력 영상으로부터 특징 정보를 추출하기 위해 사용되는 전처리(prepropcessing) 필터의 수가 분류 성능에 미치는 영향에 대해 분석한다. SRM 필터를 사용한 실험에서 필터의 수를 단순히 증가시키는 것은 성능 향상이 도움이 되지 않으며, 효과적인 필터를 선별해서 사용하는 것이 보다 우수한 성능을 가짐을 확인하였다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.12 no.12
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• pp.5685-5700
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• 2018

Cyber intelligence, surveillance, and reconnaissance (ISR) has become more important than traditional military ISR. An agent used in cyber ISR resides in an enemy's networks and continually collects valuable information. Thus, this agent should be able to determine what is, and is not, useful in a short amount of time. Moreover, the agent should maintain a classification rate that is high enough to select useful data from the enemy's network. Traditional feature selection algorithms cannot comply with these requirements. Consequently, in this paper, we propose an effective hybrid feature selection method derived from the filter and wrapper methods. We illustrate the design of the proposed model and the experimental results of the performance comparison between the proposed model and the existing model.

• International Journal of Internet, Broadcasting and Communication
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• v.13 no.3
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• pp.42-49
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• 2021

As cyber attacks become more intelligent, there is difficulty in detecting advanced attacks in various fields such as industry, defense, and medical care. IPS (Intrusion Prevention System), etc., but the need for centralized integrated management of each security system is increasing. In this paper, we collect big data for intrusion detection and build an intrusion detection platform using deep learning and CNN (Convolutional Neural Networks). In this paper, we design an intelligent big data platform that collects data by observing and analyzing user visit logs and linking with big data. We want to collect big data for intrusion detection and build an intrusion detection platform based on CNN model. In this study, we evaluated the performance of the Intrusion Detection System (IDS) using the KDD99 dataset developed by DARPA in 1998, and the actual attack categories were tested with KDD99's DoS, U2R, and R2L using four probing methods.

• Electronics and Telecommunications Trends
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• v.37 no.1
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• pp.10-20
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• 2022

A drone without attaching guns or bombs can be a dangerous weapon, since its motor speed is greater than 3000 rpm, which is similar to that of a mower powered by a LiPo battery. The anti-drone system is the only means of detecting and neutralizing drone attacks. Many defense companies around the world provide solutions using various types of equipment (for example, radar, cameras, jamming guns, and net guns). ETRI has also developed a Low-Altitude Drone Detection (LADD) system consisting of Ku-band radar and an Electro-Optical/Infra-Red (EO/IR) camera. In this paper, we summarize recent technical advances in anti-drone systems around the world and introduce the features and describe the performance of the LADD system.