• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2004.05a
• /
• pp.699-704
• /
• 2004

As being inconvenient to apply reinforced concrete structure to high-rise buildings, it is applied steel structured system. Therefore light-weight wall systems are applied as partition wall to reduce the self-load of the building. But, the required performances of a light-weight wall are not evaluated systematically. As a field survey result, partition walls of house-to-house were not showed their respected performances, so the dwellers are feel so worse the quality of the whole building. In steel-structured high-rise buildings especially, occupant's dissatisfaction concerned indoor noise was high because curtain wall systems having a high air-tight performance isolate the outdoor noise making masking effect. Therefore wall systems which have high performances of sound insulation and air-tightness are required in high-rise buildings. As a result, a new drywall system was presented and the performance was verified with field test.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
• /
• v.15 no.1
• /
• pp.36-44
• /
• 2022

Reversible data hiding techniques have been developed to hide confidential data in the image by shifting the histogram of the image. These techniques have a weakness in which the security of hidden confidential data is weak. In this paper, to solve this drawback, we propose a technique of triple encrypting confidential data using pixel value information and hiding it in the cover image. When confidential data is triple encrypted using the proposed technique and hidden in the cover image to generate a stego-image, since encryption based on pixel information is performed three times, the security of confidential data hidden by triple encryption is greatly improved. In the experiment to measure the performance of the proposed technique, even if the triple-encrypted confidential data was extracted from the stego-image, the original confidential data could not be extracted without the encryption keys. And since the image quality of the stego-image is 48.39dB or higher, it was not possible to recognize whether confidential data was hidden in the stego-image, and more than 30,487 bits of confidential data were hidden in the stego-image. The proposed technique can extract the original confidential data from the triple-encrypted confidential data hidden in the stego-image without loss, and can restore the original cover image from the stego-image without distortion. Therefore, the proposed technique can be effectively used in applications such as military, medical, digital library, where security is important and it is necessary to completely restore the original cover image.

• Korean Architects
• /
• no.10 s.163
• /
• pp.63-67
• /
• 1982

• Korean Architects
• /
• no.8 s.221
• /
• pp.89-93
• /
• 1987

• Proceedings of the KIEE Conference
• /
• 2009.07a
• /
• pp.1441_1441
• /
• 2009

This paper describes performance of sealing integrity and bending strain of HV polymeric bushing with thermal mechanical test. Generally the properties of FRP tube can be influenced by the winding angle, wall thickness and winding tension. As a results, multi winding bushing shows that it has max deflection in the range of 16.5~16.9 mm.

• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2022.11a
• /
• pp.199-200
• /
• 2022

In this study, the material properties of UHPC mixed with graphene was investigated. The compressive strength, the bending strength and the permeability test was conducted. As a result, there was no improvement in compressive strength by the graphene, but the bending strength increased by 20% by the graphene. The water penetration amount decreased by 80% by the graphene.

• Journal of the Korea Society of Computer and Information
• /
• v.16 no.8
• /
• pp.77-84
• /
• 2011

In this paper we implement a 6LoWPAN protocol on the MICAz sensor platform, which could minimize packet re-transmission, and support security primitives for packet integrity and confidentiality. And we also present a performance evaluation of the implemented protocol calculated according to the cryptographic algorithms. In the re-transmission method, time stamp, nonce, and checksum are considered to protect replay attacks. As cryptographic algorithms, AES, 3DES, SHA2, and SHA1 are implemented. If transmission errors (thus, packet losses) and the number of hops are increase then, packet re-transmissions are increase exponentially from the experimental results. Also, the result shows that cryptographic operations take more time than packet re-transmission time.

• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2023.05a
• /
• pp.147-148
• /
• 2023

Steel doors, which are common in general buildings, do not seal the gap between the door and the floor, so drafts, noise, dust, and lights flow from the outside, and shielding devices are installed in various materials and methods, such as adding magnetic gate paper to the side of the door or installing a gasket under the door, but performance is limited. Accordingly, in order to fundamentally solve these problems, we researched and developed a double gap blocking device that can improve fire resistance and airtightness performance in steel doors. Unlike general products, the double gap blocking device has the advantage of maximizing airtight performance by forming an air layer in the center when the door is closed, as well as greatly improving the fire resistance performance, which is the basic performance of the fire door.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.38 no.3
• /
• pp.377-385
• /
• 2018

Super-speed vacuum tube system, where the air resistance is minimized to obtain high speed of the vehicle, is considered to be a viable alternative transportation system. Air-tightness is one of the most important design requirements of the system, because the internal pressure of the system needs to be maintained significantly lower than the atmospheric pressure. This study performed an experimental test, where a series of concrete tube specimens were applied by external loads to induce cracks and the effective air-permeability of the cracked tube structures were measured. The test results indicates that the information on the length and the width of the load-induced cracks are not enough to anticipate the system air-tightness, whereas the load-induced displacement has higher correlation with the systems air-tightness. Based on these results, a direction of future research for effect of the load-induced cracks on the system air-tightness is suggested.

• Proceedings of the Korea Information Processing Society Conference
• /
• 2006.05a
• /
• pp.967-970
• /
• 2006

정보 보호의 목표는 정보자산의 기밀성, 무결성, 가용성을 보장함으로써 정보시스템의 신뢰성과 안전성을 확보하고 이를 통하여 기관이나 조직에서 추구하는 사업에 대한 영속성 보장의 기반을 제공하는 것이다. 접근 제어는 정보 보호의 목표인 기밀성, 무결성을 하기 위한 수단으로 많이 사용된다. 즉, 인가받지 않은 주체에게는 접근을 허용하지 않고, 인가된 주체에 대해서는 신뢰성 있는 정보를 제공하기 위해 정보에 대한 접근 제어를 한다. 그러나 가용성 측면을 무시하고 기밀성과 무결성만을 지나치게 강조할 경우 사용자에게 제공되는 정보는 이미 과거의 정보가 되어 아무런 가치가 없을 수도 있다. 이에 본 논문에서는 정보 보호의 3대 목표를 모두 만족하는 접근제어 시스템을 구축하는데 있어서 바람직한 방향을 제시하고자 한다.