• Proceedings of the Korean Professional Engineer Association Conference
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• 1992.12a
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• pp.143-150
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• 1992

“The Japan Sea Rim Nations” is not one that was formed under a specific idea, as in the case of the European Community, in the respect of politics, economy and culture. At present, in particular after the Cold War, Japan has extended exchange on regional and private levels with the countries located on the other side of the Japan Sea from the first stages of friendship to economic relationships. In the future, it is necessary to promote the establishment of an international exchange network and traffic system for each of the traffic facilities in order to build up the Block that will mainly contribute to the economies of countries and regions in the area. For that purpose, it Is fundamental to reexamine the national land planning and the local development planning of each of the countries. From the standpoint of technology, the issues to be looked into are : study and development on marine civil engineering such as structures over straits : study and development on the construction engineering of express ways and express rail roads : development of vehiclessuch as cars and trains ; I propose approaches to my vision of these traffic systems from my standpoint as an engineer in this paper.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.41 no.9
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• pp.55-65
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• 2004

ATM was recommended by the ITU and ATM Forum as a means of transportation for B-ISDN. At this time, due to the comprehensive mature of ATM protocol, ATM has been adapted as the backbone system for carrying Internet traffi $c^{[1,2,3,4]}$. But major conceptsregarding the ATN protocol will be used on future technology. This paper presents preventive congestion control mechanisms for detecting HTR(Hard-To Reach) code in ATM systems, in particular for an improved HTR call registration method using network signaling information will discussed. In high speed circuit switching system environments, a fast HTR control mechanism is necessary. We present research results for improving HTR call registration and control methods using network signaling information and fuzzy control mechanisms. We concluded that it showed fast congestion avoidance mechanisms with a fewer system load maximized the efficiency of network resources by restricting ineffective machine attempts.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2017.05a
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• pp.475-481
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• 2017

In this paper, high speed camera images were used to analyze the supercritical injection behavior of liquid hydrocarbon compounds used as main components of propellant fuel. Decane and Methylcyclohexane (MCH), which have different critical points among kerosene constituents, were selected as experimental fluid and Shadowgraphy technique was used for the analysis. The difference in the temperature variation from the initial injector state of the subcritical condition until the vaporization occurs was represented by the different behaviors of Decane and MCH. However, under the Supercritical conditions, the enthalpy of vaporization near the critical point approaches zero and the phase change to the Supercritical phase occurs instead of vaporization process. In the phase change of the Supercritical system, there was no rapid density change, so the liquid state image was observed in both the Decane and MCH.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2017.05a
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• pp.131-136
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• 2017

High speed under water vehicle by using solid rocket motor, which is a natural cavitation type, was tested. The vehicle's speed and running distance was measured, and pressure sensors installed on the surface of the vehicle show pressure-time history of pressures according to the development of the supercavitation. Underwater cameras installed on the wall of the test pool recorded whole processes from the onset of the supercavitation to fully developed one. CNU-SuperCT based on 2-dimensional inviscid theoretical analysis was used to simulate the test result. In consideration of CNU-SuperCT does not include the control fins of the vehicle, simulation results agree with test results very well. Also, pictures from underwater cameras support the test results.

• Journal of the Korean Data and Information Science Society
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• v.23 no.3
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• pp.419-446
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• 2012

National statistical system in Korea has developed along with national economic agenda such as a government oriented high economic growth and has formed to a typical diversified statistical system. While the national statistics have been produced whenever they are needed, they are facing the critics that production of basic statistics were lack of balance. Grasping the statistical demand properly, enhancing the statistical concurrence with international organization, preventing the production of overlapped and similar statistics, and improving the professionalism of manpower in statistical industry are the structural problems that Korean statistical system has to get over. It is important to strengthen the coordination mechanism and the governance structure of the national statistical system to level up the integrity and credibility of statistical program. The length of Chief Statistician's tenure need to be assured.

• Journal of Biomedical Engineering Research
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• v.25 no.6
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• pp.617-621
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• 2004

In recent, researchers in the field of Bioinformatics need to analyze thousands of genome sequences efficiently according to introduce of new analysis methods and technologies such as genome expression microchip. This rapid growth in the field of bio-engineering needs computing resources to analyze rapidly for genome sequences, but it does not introduce the computing resources due to an enormous investment expense. The core factor of this study is integrated environment based PC-Cluster system & high speed access rate up to 155Mbps, continuous collection system for bio-information at home and abroad. The results of the study are establishment & stabilization of information and communication infrastructure, establishment & stabilization of high performance computer network up to 155Mbps, development of PC-Cluster system with 32 nodes, a parallel BLAST on Cluster system, which can provides scalable speedup in terms of response time, and development of collection & search system for bio-information.

• Journal of the Korean Society of Propulsion Engineers
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• v.18 no.5
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• pp.43-53
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• 2014

Shock tunnels are known to be capable of simulating flow-field environments of supersonic and hypersonic flights. They have been operated successfully world-wide for almost half a century. As a consequence of the strong interest in hypersonic vehicles in Korea, attention has been given on this type of facility and so an intermediate-sized shock tunnel has lately been built at KAIST. In the light of this, this paper presents our tunnel performance and some of the model scramjet test data. The freestream flow used in this work replicates a supersonic combustor environment for a Mach 5.7 flight speed.

• Journal of the Korean Society of Propulsion Engineers
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• v.22 no.4
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• pp.12-17
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• 2018

A natural cavitation-type high-speed underwater vehicle with solid rocket motor is tested, and its speed and running distance are measured. The outputs from pressure sensors on the surface of the vehicle reveal a pressure-time history reflecting the development of supercavitation. Underwater cameras installed on the wall of the test pool record the entire process from the onset of supercavitation to its full development. CNU-SuperCT, based on two-dimensional inviscid theoretical analysis, is used to simulate test results. Considering CNU-SuperCT does not include the control fins of the vehicle, simulation results agree with test results very well. Additionally, pictures from underwater cameras support the test results.

• Journal of the Korean Society of Propulsion Engineers
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• v.22 no.6
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• pp.11-18
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• 2018

A pulse detonation engine (PDE) requires high operating frequency greater than 100 Hz to get meaning thrust as a propulsion devise. Thus a PDE needs an ignition circuit operating precisely at high operating frequencies. In this paper AC(alternating current) and DC(direct current) types of ignition circuits were designed and compared. Each circuit was tested at operating frequencies from 16.66 to 100.00 Hz by measuring the input signal of each circuit and the voltage change in the primary coil of the transformer. Results show that the DC power circuit can attain a maximum error rate of 5.15% at higher operating frequencies, whereas the AC power circuit displays a negligible agreement with the operating signal at frequencies greater than 33.33 Hz. Therefore it is confirmed that DC-powered ignition circuit is preferable for the PDE operating at high frequencies.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.30 no.6
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• pp.1279-1289
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• 2020

To securely protect users' sensitive information and national secrets, the importance of cryptographic modules has been emphasized. Currently, many companies and national organizations are actively using cryptographic modules. In Korea, To ensure the security of these cryptographic modules, the cryptographic module has been verified through the Korea Certificate Module Validation Program(KCMVP). Most of the domestic cryptographic modules are CPU-based software (S/W). However, CPU-based cryptographic modules are difficult to use in servers that need to process large amounts of data. In this paper, we propose an S/W cryptographic module that provides a high-speed operation using GPU. We describe the configuration and operation of the S/W cryptographic module using GPU and present the changes in the cryptographic module security requirements by using GPU. In addition, we present the performance improvement compared to the existing CPU S/W cryptographic module. The results of this paper can be used for cryptographic modules that provide cryptography in servers that manage IoT (Internet of Things) or provide cloud computing.