• Journal of the Korea Institute of Information Security & Cryptology
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• v.31 no.6
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• pp.1261-1266
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• 2021

Existing information security risk assessment methods focus on evaluating the vulnerability of information assets. However, when the form of information assets changes and new types of information assets emerge, there is a limitation in that the evaluation standards for them are also added or deleted. Existing methods have insufficient research on the path through which cyber threats are introduced. In particular, there is very little research on blocking the inflow path for web-based information systems with public IPs. Therefore, this paper introduces the main research contents of the BDLA (Blockade and Defense Level Analysis)-based information security risk assessment model. In addition, by applying the BDLA-based information security risk assessment model, the information security risk level was studied by measuring the blockade level and security equipment level of 17 public institutions.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.43 no.4
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• pp.190-197
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• 2020

Recently there was an incident that military radars, coastal CCTVs and other surveillance equipment captured a small rubber boat smuggling a group of illegal immigrants into South Korea, but guards on duty failed to notice it until after they reached the shore and fled. After that, the detection of such vessels before it reach to the Korean shore has emerged as an important issue to be solved. In the fields of marine navigation, Automatic Identification System (AIS) is widely equipped in vessels, and the vessels incessantly transmits its position information. In this paper, we propose a method of automatically identifying abnormally behaving vessels with AIS using convolutional autoencoder (CAE). Vessel anomaly detection can be referred to as the process of detecting its trajectory that significantly deviated from the majority of the trajectories. In this method, the normal vessel trajectory is gridded as an image, and CAE are trained with images from historical normal vessel trajectories to reconstruct the input image. Features of normal trajectories are captured into weights in CAE. As a result, images of the trajectories of abnormal behaving vessels are poorly reconstructed and end up with large reconstruction errors. We show how correctly the model detects simulated abnormal trajectories shifted a few pixel from normal trajectories. Since the proposed model identifies abnormally behaving ships using actual AIS data, it is expected to contribute to the strengthening of security level when it is applied to various maritime surveillance systems.

• Journal of the Korea Society for Simulation
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• v.30 no.2
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• pp.33-40
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• 2021

The situation of high-altitude electromagnetic pulses (HEMP) arises from high-altitude nuclear explosions. The HEMP situation can be simulated through the threat level investigation (TLI). In this paper, the induced voltage according to the antenna type of the tactical mobile radio communication system was measured and analyzed by TLI. Under the influence of HEMP, electronic equipment can be paralyzed or damaged. HEMP protection filters are commercially available for power lines and signal lines. However, commercialization of HEMP filters for antennas is insufficient, and even some of them exist for lightning protection. In order to make an appropriate HEMP protection filter according to the frequency and type of the antenna, the induced voltage was measured and the maximum induced voltage was analyzed through extrapolation. It was found that the measured induced voltage decreased as the frequency increased, such as in the HF, VHF and UHF bands of the measurement results.

• Journal of East-Asian Urban History
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• v.2 no.1
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• pp.113-128
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• 2020

Right before the outbreak of the War of Resistance Against Japanese Aggression (1937-1954), the Great Eastern Broadcasting Station (GEBS) was established in Shanghai under the aegis of the Ministry of Foreign Affairs of Japan (MOFA). Prior to the launching of the GEBS, Japan had not owned similar radio stations in China for years. As a result, the Embassy of Japan in China held rounds of discussions on the plan and Japanese governments, ranging from the MOFA, the Navy, the Army, the Ministry of Communications (MOC), and NHK-Japan Broadcasting Corporation (Nihon Hoso Kyoku) provided financial, technological, and equipment support. In the mid-1930s when the Sino-Japanese relations became intensified, the GEBS assumed the primary role of disseminating government policies to over 30,000 Japanese expatriates in Shanghai to make sure that they could remain settled while supporting military endeavors of the Japanese army once the war between China and Japanese broke out. After 1937, the GEBS became an essential propaganda tool to advance imperial policies of Japan. Although the station differed from the Army-controlled Greater Shanghai Broadcasting Station (Dai Shanhai Hoso Kyoku) in many aspects, it was in line with the latter in terms of advancing wartime ideology of the Japanese empire. As the Japanese-occupied areas were enlarged, target audience of the GEBS also expanded to Chinese people and foreign nationals when Japanese, English, Russian, and Shanghai-dialect news was broadcast by the station. Suffice it to say that the GEBS was closely related to wartime propaganda of the Japanese imperial expansion.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.27 no.1
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• pp.62-68
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• 2023

An aerial relay system utilizing an unmanned aerial vehicle(UAV) or drone is addressed for event-driven operations such as temporary communication services for disaster affected area, military and first responder support. UAV relay system (URS) targets to provide a reliable communication service to a remote user equipment or an operator, therefore, a fast UAV placement to guarantee a minimum quality of service(QoS) is important when an operation is requested. Researches on UAV utilization in communication systems mostly target to derive the optimal position of UAV to maximize the performance, however, fast deployment of UAV is much more important than optimal placement under emergency situations. To this end, this paper derives the feasible area for UAV placement, investigates the effect of performance requirements on that area, and suggests UAV placement to certainly guarantee the performance requirements. Simulation results demonstrate that the feasible area derived in this paper matches that obtained by an exhaustive search.

• Journal of Advanced Navigation Technology
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• v.27 no.2
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• pp.173-181
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• 2023

Aircraft carriers need to maintain an orderly flow of aircraft in order for military ships to conduct combat through aircraft. Maintaining aircraft flow is an important factor in strengthening ship and aviation safety. In order to maintain aircraft flow, it is essential to develop a state-of-the-art air control system that provides higher quality control information by simultaneously accommodating radar-based monitoring information and monitoring information based on CNS integrated technology. Based on this point, this study describes the function and operation method of specific control equipment for the operation of the Aviation Support System and Air Traffic Control System required to operate light aircraft carriers in Korea based on overseas cases.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.23 no.1
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• pp.112-122
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• 2024

Recently, as unmanned aerial vehicle technology such as drones has developed, there are many environmental, social and economic benefits, but if there is malicious intent against important national facilities such as airports, public institutions, power plants, and the military, it can seriously affect national safety and people's lives. It can cause damage. To respond to these drone threats, attempts are being made to introduce detection equipment such as RF scanners. In particular, power transmission towers installed in substations, power plants, and Korea's power system can affect detection performance if the transmission tower is located in the RF scanner detection path. In the experiment, a commercial drone was used to measure the signal intensity emitted from the drone and confirm the attenuation rate. The average and maximum attenuation rates showed similar trends in the 2.4 GHz and 5.8 GHz bands, and were also affected by the density of the structure.

• Journal of Advanced Navigation Technology
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• v.27 no.6
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• pp.763-769
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• 2023

Flight control computers for unmanned aerial vehicles are avionics that require high reliability and are generally designed to be multiplexed for margins on failures. The multiplexed flight control computer should include an interface through discrete signals and CCDL for synchronization and fault separation between channels. With the development of unmanned aerial vehicle technology, various types of platforms such as AAM and LPI are being developed in the private and military, which require advanced control performance for high-performance flight control and SWaP optimization of onboard equipment. In this paper, we designed a optimized flight control computer architecture for unmanned aerial vehicles for multiplexing processing and performed a software design for input and output control. In addition, input/output processing performance was evaluated through the implemented flight control computer and input/output software.

• Korean Security Journal
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• no.19
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• pp.105-138
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• 2009

This study's purpose is to present the improvement of effectiveness of security activity for international conference among Several Countries which can be held hereafter. On the basis of security activity problems originating in APEC that had been held in Busan in 2005. I made up questions three times to on the members of the police, military, fire figher and national intelligence service who had experienced in Busan APEC and recognition of possible problem and possibility of improvement on each item of questions was analyzed by Delphi Method. Also interviews with 4 security experts selected from each security agency were conducted to present improvement in each part of problem. The results obtained from the face to face interview with four experts of security-enforcement agency about the role and importance of site activity stage for international conference among several countries are as followings ; First, the system that experienced security-enforcement agents can be selected for the next national security event is needed, by data-basing the security-enforcement agents who were experienced in security event as man power management. Second, the middle-term plan for the introduction of high-tech equipment and joint inspection with relevant security agents are needed for the efficient explosive technical detection. Third, high-tech security equipment could be introduced through the international high-tech security equipment exhibition. Fourth, an anti-terrorism plan should be measured by sharing information through the cooperation with domestic and international intelligence agency. Fifth, public relations should be measured systematically by organization rather than agents' individual public relations. Sixth, political consideration to secure integrative coordination with other agency is needed for security activity, through normal cooperation with fire fighting related agency such as an electric, gas, elevator company. Seventh, a definite press guideline is needed for a convenient news coverage and safety during security event.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.23 no.8
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• pp.759-769
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• 2013

Electronic equipment has been applied to virtually every area associated with commercial, industrial, and military applications. Specifically, electronics have been incorporated into avionics components installed in aircraft. This equipment is exposed to dynamic loads such as vibration, shock, and acceleration. Especially, avionics components installed in a helicopter are subjected to simultaneous sine and random base excitations. These are denoted as sine on random vibrations according to MIL-STD-810F, Method 514.5. In the past, isolators have been applied to avionics components to reduce vibration and shock. However, an isolator applied to an avionics component installed in a helicopter can amplify the vibration magnitude, and damage the chassis, circuit card assembly, and the isolator itself via resonance at low-frequency sinusoidal vibrations. The objective of this study is to investigate the dynamic characteristics of an avionics component installed in a helicopter and the structural dynamic modification of its tray plate without an isolator using both a finite element analysis and experiments. The structure is optimized by dynamic loads that are selected by comparing the vibration, shock, and acceleration loads using vibration and shock response spectra. A finite element model(FEM) was constructed using a simplified geometry and valid element types that reflect the dynamic characteristics. The FEM was verified by an experimental modal analysis. Design parameters were extracted and selected to modify the structural dynamics using topology optimization, and design of experiments(DOE). A prototype of a modified model was constructed and its feasibility was evaluated using an FEM and a performance test.