• Journal of the Korean Society for Railway
• /
• v.19 no.5
• /
• pp.576-584
• /
• 2016

In this study, we measured the air tightness of a train using pressure variation in tunnels. To estimate the air tightness of a train is essential to comprehend the pressure variation of the cabin because air tightness is strongly related with ear discomfort. If we can determine the air tightness, we can predict the pressure variation of the cabin. Also, ear discomfort is a problem that can be caused in a high speed train, as well as in Korea's Great Train Express. In this study, we compared the various international standards for ear discomfort and estimated the air tightness of each vehicle based on experimental data obtained using the ITX, KTX and KTX-sancheon(honam) vehicles. The internal pressure variation of the trains is numerically calculated using the air tightness value. The results are good compared to the experimental results. Instead of flap type ventilation, in the future, continuous ventilation equipment will be needed for speed-up.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.21 no.12
• /
• pp.2333-2340
• /
• 2017

Recently industry is suffering severe losses of important internal information, and most of the leaks result from the insiders. Thus, various technological counter measures are being studied in order to protect private organization information. In this paper, among various internal information leakage path protection mechanisms, we propose a technique for preventing files which are defined as confidential from being copied or moved through USB. The implemented confidential file loss prevention system is composed of both signature insert manager and confidential file detect manager. The signature insert manager allows a system administrator to insert a special pattern specifying a classified confidential file, while the confidential file detect manager protects confidential file leakage when a user attempts to move or copy a confidential file to the USB memory. This results would be contributed to reducing the damage caused by leakage of confidential files outside of the company via USB.

• Review of KIISC
• /
• v.16 no.5
• /
• pp.35-44
• /
• 2006

컴퓨터가 다루고 있는 정보의 기밀성(confidentiality of information)을 보호하는 일은 매우 중요하며, 그 중요성은 날이 갈수록 증가하고 있다. 그럼에도 불구하고, 실제로 정보의 기밀성과 무결성(integrity)을 완벽하게 보호해 주는 컴퓨터 시스템은 매우 찾기가 어렵다는 것이 또한 알려진 사실이다. 기존에 존재하는 이론적인 프레임워크들은 기밀성을 표현하기에는 부적절하며, 기밀성 보호를 위한 실제적인 시스템들 역시 이론적인 면에서 충분히 만족스럽지 못하다. 이와 같은 현실에서 타입시스템을 가지는 프로그래밍 언어가 정보 기밀성 보호를 위한 효과적인 방법으로 새로운 관심을 받고 있으며, 상당한 연구가 이 방향으로 진행되고 있다. 본 논문에서는 이제까지 진행되었던 연구들을 중심으로 프로그래밍 언어를 이용한 정보 기밀성 보호의 연구 동향과 주요 과제들을 소개하고자 한다.

• Convergence Security Journal
• /
• v.15 no.7
• /
• pp.39-45
• /
• 2015

Industrial secrets that companies own recently protected by various act related industrial security such as Trade Secret Act, Act on Prevention of Divulgence and Protection of Industrial Technology, etc. However, despite such protection infringement and leakage accidents of industrial secrets is increasing every year. According to a survey conducted by KAITS(Korean Association for Industrial Technology Security) annual average of estimated damage by industrial secrets leakage is estimated to be "50 trillion won." This is equivalent to the amount of annual revenue of small businesses more than 4,700 units. Following this, industrial secrets leakage causes serious damages to competitiveness of nation and companies and economic. However investment and effort to the industrial secrets leakage crime is lack of level compared to the scale of damage. Actually, most companies except some major companies are lack of response action about industrial secrets leakage because of shortage of separate organization, workforce, budget for industrial secrets leakage security. This paper aims to understand the overall flow of the industrial secrets leakage crime through various taxonomy such as cause of occurrence and leakage pathway and grasp the condition of damage from industrial secrets leakage through analyzation of internal and external industrial secrets leakage crime. This is expected to be the basis for related research.

• The Journal of the Convergence on Culture Technology
• /
• v.7 no.1
• /
• pp.632-639
• /
• 2021

In this paper, we proposed a reversible data hiding technique that greatly enhances the security of confidential data by encrypting confidential data and then spatially encrypting the encrypted confidential data and hiding it in the cover image. When a result image is generated by hiding the encrypted confidential data in the cover image using a spatial encryption technique, the quality of the result image is very good, and the original cover image and the result image cannot be visually distinguished. Since the encrypted confidential data is spatially encrypted and concealed, it is not possible to know where the encrypted confidential data is concealed in the result image, and the encrypted confidential data cannot be extracted from the result image. Even if the encrypted confidential data is extracted, the original confidential data is not known because the confidential data is encrypted. Therefore, if confidential data is concealed in images using the proposed technique, the security of confidential data is greatly improved. The proposed technique can be effectively used in medical and military applications.

• Proceedings of the Korean Society of Propulsion Engineers Conference
• /
• 2017.05a
• /
• pp.517-520
• /
• 2017

In this paper, we represented the structural design parameter effect on the sealing gap behavior of solid rocket motor case and nozzle connection under penetrated pressure through the sealing path between insulation rubber and the ablative FRP bonded on the inside convergent wall of nozzle. It is important to keep the good sealing capacity during all the combustion time of SRM. To achieve the crucial role of sealing system of SRM, designers must consider design factors for stable sealing clearance gap as the nearly unchanged initial design state as possible for sufficient compression rate of O-ring under sealing gap pressure.

• Aerospace Engineering and Technology
• /
• v.8 no.1
• /
• pp.73-81
• /
• 2009

Casing leak tests using three kinds of static seals are performed by simulating test section for a 75 ton thrust class turbopump under ambient and cryogenic temperature environment. As results of application of Conical, PTFE, and C static seals to leak tests, even though they all work in normal temperature condition, only the PTFE and C static seals show good sealing performance in cryogenic condition. However, the Conical static seal fails because of the different thermal expansion rates due to the use of different materials in a LOX pump. It is found that unlike the PTFE and C static seals with sealing surfaces in axial direction, the sealing surface of the Conical static seal is in radial direction that may cause leak when the casings thermally shrink in radial direction. Especially, the C static seal reveals excellent sealing performance even for a used seal.

• Proceedings of the Korea Institutes of Information Security and Cryptology Conference
• /
• 1996.11a
• /
• pp.336-345
• /
• 1996

정보 보안의 세 가지 목적은 기밀성, 무결성, 유용성이다. 모든 정보 시스템에서 정보 보안에 관한 필요성이 대두되면서 기밀성뿐만 아니라 무결성도 보장하는 보안 모델이 필요하다. BLP와 Biba는 각각 기밀성과 무결성을 보장하는 보안 모델로서 BLP 모델이 무결성을 고려하지 않기 때문에, Biba 모델은 기밀성을 고려하지 않기 때문에 접근할 수 있는 정보에 한계가 있다. 본 논문에서는 여러 정보시스템 중에서 주로 군사 정보 시스템으로 구현된 BLP와 Biba 모델을 이용해서 기밀성과 무결성을 만족하는 보안 모델을 제시한다. BLP 모델과 Biba 모델을 결합함으로써 BLP 모델을 통해 기밀성을, Biba 모델을 통해 무결성을 보장한다

• Review of KIISC
• /
• v.6 no.1
• /
• pp.65-78
• /
• 1996

본 논문에서는 JPEG 알고리즘을 이용하여 화상데이터를 부호화할때 디지털 서명문과 같은 기밀 데이터를 몰래 집어넣어 합성하는 방식에 대하여 고찰한다 그 기본원리는 DCT 계수를 양자화 할 때 필연적으로 생기는 오차를 이용하는 것으로 0이 아닌 양자화 계수를 합성하고자 하는 기밀데이터에 따라 근처의 정수로 조절하는 것이다. 이 방식을 SIDBA 표준화상에 적용하여 화상의 열화는 무시할 정도로 작으면서 원하는 크기의 기밀 데이터를 합성할 수 있음을 보인다. 또한, 화질의 열화를 최소화시키면서 일정량의 기밀 데이터를 합성시키기 위하여 블록당 1화소를 적절히 선택하여 제3자의 공격에 대한 안전성을 향상시키는 방법을 제시하고 컴퓨터 시뮬레이션을 통하여 성능을 분석한다.

• Review of KIISC
• /
• v.1 no.1
• /
• pp.124-129
• /
• 1991

정보 보안의 요소는 인가되지 않은 사람이 시스템에 액세스(Access)하거나 인가없 이 사용하는 것을 방지하는 액세스 통제이다. 이를 위해서 정보의 기밀정도에 따라 보호정 도를 결정하는 기밀등급분류가 이루어져 정보를 선택관리하는체계가 이루어 져야한다. 정 보를 선택관리하기 위해서는 보호할 만한 정보를 식별하고, 식별된 중요정보를 어떤 방법 으로 유지, 관리, 이용할 것인지를 규정하는 것이 필요하다. 본 논문에서는 정보 기밀등급 의 체계적인 분류방법에 대해 살펴보기로 한다.