• Korean Journal of Heritage: History & Science
• /
• v.49 no.4
• /
• pp.64-79
• /
• 2016

The purpose of the present study is to clarify the process of change to the pond at the Jongmyo Shrine(宗廟), from the Joseon Dynasty period to the modern and contemporary era. The consequent research results can be summarized as follows. The first record of the Jongmyo pond is confirmed in the "Annals of King Sejong(世宗實錄)". The pond, which was being constructed at the time, refers to the current upper pond(上池). A pair of islets(雙島) were constructed during the Sukjong(肅宗) period, with several trees planted on the middle islet(中池). The middle pond is thick with lotuses. In particular, the middle island on the middle pond subsequently changed into a single island(單島), which is likely to be related to the pond expansion during the reign of Youngjo(英祖). When the lower pond(下池), involving dualistic arrangement, was constructed in the modern and contemporary era, the pond of the Jongmyo Shrine underwent a drastic transformation phase. The lower pond was constructed before 1947 at the latest, and when the right side of the lower pond was filled in the mid 1980s, the dualistically arranged lower pond became a unified type of lower pond. On the other hand, the bank protections of the upper and middle ponds were constructed with earth, but was subsequently modified into its current form using stone.

• Journal of the Institute of Electronics Engineers of Korea SP
• /
• v.40 no.5
• /
• pp.378-387
• /
• 2003

Digital watermarking is the technique that embeds invisible signalsincluding owner identification information, specific code, or pattern into multimedia data such as image, video and audio. Watermarking techniques can be classified into two groups; robust watermarking and fragile(semi-fragile) watermarking. The main purpose of the robust watermarking is the protection of copyright, whereas fragile(semi-fragile) watermarking prevents image or video data from illegal modifications. To achieve this goal watermark should survive from unintentional modifications such as random noise or compression, but it should be fragile for malicious manipulations. In this paper, an invertible semi-fragile watermarkingalgorithm for authentication and detection of manipulated location in MPEG-2 bit-stream is proposed. The proposed algorithm embeds two kinds of watermarks, which are embedded into quantized DCT coefficients. So it can be applied directly to the compressed bit-stream. The first watermark is used for authentication of video data. The second one is used for detection of malicious manipulations. It can distinguish transcodingin bit-stream domain from malicious manipulation and detect the block-wise locations of manipulations in video data. Also, since the proposed algorithm has an invertible property, recovering original video data is possible if the watermarked video is authentic.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.37 no.1
• /
• pp.93-103
• /
• 2017

Many countries are interested in the development of the Antarctic area because of the abundant resources and living things of high research value. Korea completed the second Antarctic research station in 2014 and spurring the development of the Antarctic area by constructing runway for the airplanes and a third Antarctic research station. However, frozen soils, unlike typical soils, are sensitive to creep behavior due to the influence of ice and unfrozen water. The creep tests for evaluating creep behaviors on the frozen soils require expensive laboratory equipments and large amount of time. Thus, various empirical models had been developed to describe the unconfined compressive creep behavior of frozen soils. In this study, new analytical creep model on frozen sands was proposed by modifying Ting's Tertiary creep model with a new parameter considering fine contents. Thus, the unconfined compressive creep tests were conducted with the frozen specimens of dense Jumoonjin sand with fine contents of 0, 5, 10 and 15% under various loads at -$5^{\circ}C$, -$10^{\circ}C$ and -$15^{\circ}C$. Consequently, the modified Tertiary creep model with a new parameter for fine contents are not enough for the description of the acutal creep behavior of the frozen sand and new framework should be developed.

• Proceedings of the Korea Information Processing Society Conference
• /
• 2010.11a
• /
• pp.1834-1836
• /
• 2010

프로테오믹스는 세포 안 또는 개체 안의 모든 단백질을 총체적으로 연구하는 분야이다. 단백질 동정은 단백질이 어떤 아미노산의 서열로 구성되었는지를 확인하는 것이다. 하지만 Post-translational modification과 같은 단백질 변형을 고려하게 되면 단백질 동정은 매우 어렵게 된다. $MOD^i$ 알고리즘은 단백질 동정을 할 때 Post-translational modification의 종류나 개수에 제한 없이 단백질 동정을 정확하게 수행한다. 하지만, 대용량 단백질 서열 데이터베이스를 사용하면 수행시간이 많이 걸리는 단점이 있다. 본 논문에서는 $MOD^i$를 보완하기 위해 대용량 데이터베이스에서 후보 단백질을 선정하는 알고리즘을 통해서 개선된 $MOD^f$ 알고리즘을 제안하고 Target-decoy search strategy를 적용하여 정확성을 분석한다. 후보 단백질 선정 알고리즘과 Target-decoy search strategy 적용 결과 $MOD^f$는 $MOD^i$에 비해 정확도를 희생하지 않으면서 수행속도는 약 2배 향상되었다.

• Journal of Korean Tunnelling and Underground Space Association
• /
• v.20 no.2
• /
• pp.375-392
• /
• 2018

The shield TBM method is widely adopted for tunneling works in urban area because it has more beneficial ways to control settlement at ground surface than conventional mined tunneling. In the shield tunneling, backfill grouting at tail void is crucial because it is supposed not only to restraint ground deformation around tail void during excavation but also to compensate precedent ground settlement by pushing up the ground with highly pressurized grout. However, the tail void grouting has been found to be ineffective for settlement compensation particularly in sandy ground, which might be caused by complicate interaction between ground and tail void grouting. In this paper, the effects of tail void grouting on behavior of ground in shield TBM tunneling were investigated based on 3-dimensional finite element analyses. The results of numerical analyses indicated that backfill grouting actually reduces settlement by degrading settlement increasing rate in excavation, which means decrease of volume loss. Meanwhile, the grouting could not contribute to compensate the precedent settlement, because reduction of volume loss by grouting was found to be counterbalanced by volume change of ground.

• Explosives and Blasting
• /
• v.39 no.1
• /
• pp.10-21
• /
• 2021

Brittle materials such as rocks and concretes exhibit large strain-rate dependency under dynamic loading conditions. This means that the mechanical properties of such materials can significantly be varied according to load velocity. Thus, the strain-rate dependency is recognized as one of the most important considerations in solving problems of blast engineering or rock dynamics. Unfortunately, however, studies for characterizing the dynamic properties of domestic rocks and other brittle materials are still insufficient in the country. In this study, dynamic tensile tests were conducted using the Hopkinson pressure bar apparatus to characterize the dynamic properties of Geochang granite and high-strength concrete specimens. The dynamic Brazilian disc test, which is suggested by ISRM, and the spalling method were applied. In general, the latter is believed to have some advantages in experiments under high-strain rate deformation. It was found from the tests that there were no significant difference between the dynamic tensile strengths obtained from the two different test methods for the two materials given. However, this was not the expected result before the tests. Actually, authors expected that there be some differences between them. Hence, it is thought that further investigations are needed to clarify this results.

• Proceedings of the Korean Vacuum Society Conference
• /
• 2012.08a
• /
• pp.135-135
• /
• 2012

차세대 가속기에 적용할 얇고 매우 긴 알루미늄 진공용기를 제작하고 그 진공특성을 조사하고 있다. 진공용기 내부단면의 크기는 4.8 mm, 두께 0.5 mm (${\pm}50u{\mu}m$), 길이 6,000 mm이며 정밀압출방법으로 제작하였다. 진공용기의 재료는 알루미늄합금 6063이며 베이크아웃하지 않고 $1{\times}10^{-7}$ mbar 이하의 평균진공도를 얻어야한다. 압출제작 직후, 박판 가공 후 진공특성(진공도 변화, 진공용기 변형, 견줌탈기체율, 압력분포)을 베이크아웃 유무에 대하여 조사하였으며 해석적으로 계산한 진공도분포도와 비교하였다.

• Proceedings of the Korean Institute of Industrial Safety Conference
• /
• 2003.05a
• /
• pp.360-365
• /
• 2003

최근 선진국에서 차세대전투기와 고속철도차량 및 자동차 동체 등 경량화를 위해 복합재료의 사용범위가 증가되고 있다. 특히 강화재로서 섬유를 직물구조의 형태를 이용한 직물구조 CFRP 복합재료는 일방향 섬유에 비해 변형능력이나 기계적 특성이 우수하여 철근 콘크리트 구조물의 보강제와 같은 구조물 등에까지 그 사용이 확대되고 있다. 하지만 직물구조 CFRP 복합재료는 내부의 손상형태나 위치를 파악하기가 어렵고 직물구조의 복잡한 강화구조를 가지기 때문에 그 역학적 손상거동과 명확한 파괴거동 해석수법은 확립되어 있지 않다.(중략)

• Proceedings of the Korean Information Science Society Conference
• /
• 2003.10a
• /
• pp.817-819
• /
• 2003

인터넷 환경의 급속한 발전으로 인하여 전자우편을 통한 메시지 교환은 급속히 증가하고 있다. 하지만 전자우편의 편리성에도 불구하고 개인이나 기업에서는 스팸메일로 인한 시간과 비용의 낭비가 크게 증가하고 있다. 기존의 스팸메일에 대한 연구는 패턴 매칭에 의한 분류나 확률에 의한 분류가 대부분인데 이와 같은 방법들은 변형된 형태의 메일에 대한 탐지에 있어서 비효율적이다. 본 논문에서는 기존의 연구에 대한 문제점을 보완하기 위하여 패턴 분류문제에 있어서 우수한 성능을 보이는 SVM을 이용하여 정상적인 메일과 스팸메일을 구분하는 방안에 대하여 제시한다.

• Proceedings of the Korean Information Science Society Conference
• /
• 2001.10b
• /
• pp.541-543
• /
• 2001

본 논문에서는 실세계에서의 사용자 동작을 가상 광간의 캐릭터를 통해 나타낼 수 있는 제어방법에 대해 논한다. 사용자의 캐릭터는 스테레오 카메라 영상으로부터 얻어지는 3차원 좌표값 5개를 이용하여 표현된다. 영상에서 구하는 3차원 좌표값은 노이즈가 들어있고 불안정하므로 자연스럽고 부드럽게 변형할 수 있도록 프레임 내에서 보간 작업이 필요하다. 안정된 데이터는 신체 제약조건을 만족하는 범위에서 inverse kinematic을 이용하여 joint angle을 계산한다. 하지만 이 방법은 수학적인 계산을 통해 나온 결과이기 때문에 가끔 사용자가 원하지 않는 동작을 만들어 내는 단점을 극복해야 한다.