• 한국마린엔지니어링학회:학술대회논문집
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• 한국마린엔지니어링학회 2005년도 후기학술대회논문집
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• pp.224-225
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• 2005

The lightness of components required on marine and shipbuilding industry is requiring high strength of components. In particular, fatigue failure phenomena, which happen in metal, bring on danger in human life and property. Therefore, antifatigue failure technology takes an important part of current industries. In this study, it was investigated about endurance and fatigue crack propagation rate of according to stress ratio of SMAW commonly using for welding structures in present. Fatigue crack propagation rate(da/dN) of low load(R=0.1) was lower than of high load(R=0.6) for piping weld. And in stage I, ${\Delta}$Kth, the threshold stress intensity factor of the weld under heavy load is higher than under small load. Fatigue life shows more improvement in the weld of stress ratio R=0.l than in the weld of stress ratio R=0.6.

• Journal of the Korean Data and Information Science Society
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• 제25권2호
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• pp.431-438
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• 2014

Type I hybrid censoring scheme is the combination of the Type I and Type II censoring scheme introduced by Epstein (1954). Epstein considered a hybrid censoring sampling scheme in which the life testing experiment is terminated at a random time $T^*$ which is the time that happens rst among the following two; time of the kth unit is observed or time of the experiment length set in advance. The likelihood function of this scheme from the Rayleigh distribution cannot be solved in a explicit solution and thus we approximate the function by the Taylor series expansion. In this process, we propose four dierent methods of expansion skill.

• 한국멀티미디어학회논문지
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• 제21권4호
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• pp.478-484
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• 2018

The choice of the motion features influences the result of the human action recognition method directly. Many factors often influence the single feature differently, such as appearance of the human body, environment and video camera. So the accuracy of action recognition is restricted. On the bases of studying the representation and recognition of human actions, and giving fully consideration to the advantages and disadvantages of different features, the Dense Trajectories(DT) algorithm is a very classic algorithm in the field of behavior recognition feature extraction, but there are some defects in the use of optical flow images. In this paper, we will use the improved Dense Trajectories(iDT) algorithm to optimize and extract the optical flow features in the movement of human action, then we will combined with Support Vector Machine methods to identify human behavior, and use the image in the KTH database for training and testing.

• 디지털콘텐츠
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• 5호통권132호
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• pp.22-27
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• 2004

게임, 포털 등 디지털콘텐츠 시장을 주도하고 있는 분야에 대한 인수합병(M&A)이 본격화되면서 국내 디지털콘텐츠 시장이 뜨겁게 달아오르고 있다. 업계에서는 이제 과거와 같이 킬러콘텐츠 1~2개로 업계 선두권을 유지할 수 있는 시기는 지났으며, 다양한 분야에 대한 통합 콘텐츠를 가진 대기업형 콘텐츠 기업 시대가 도래할 것이라는 전망이 대두되고 있다. 실제로 그간 영화와 방송, 쇼핑 채널 등을 운영해온 CJ그룹은 플레너스를 인수하면서 전격적으로 온라인 시장에 뛰어들었고, SK는 지난 2002년 라이코스에 이어 지난해 싸이월드까지 인수하면서 자사의 포털사이트 네이트닷컴을 단번에 업계 3위권까지 올려놨다. KT그룹 역시 최근 KTH를 중심으로 한 콘텐츠 사업강화를 위해 M&A를 고려하고 있다고 밝히고 있다. 최근 디지털콘텐츠 기업들을 둘러싼 M&A 움직임을 통해 시장구도의 흐름을 살펴봤다.

• Wind and Structures
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• 제7권2호
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• pp.131-144
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• 2004

A technique for the simulation of atmospheric boundary layers in wind tunnels is developed and tested experimentally. The device consists of a grid made of seven horizontal and vertical evenly distributed bars in which air injection holes are drilled in order to influence the flow in the wind tunnel. The air flow in each bar can be controlled independently. Firstly, the device is used together with a rough carpet, which covers the test section floor, in order to simulate the boundary-layer characteristics over an open rural area. Hot-wire measurements, performed at different positions in the test-section, show the capability of the grid in generating the required boundary layer. An acceptable agreement with statistical values of mean velocity and turbulence profiles has been achieved, together with a good span-wise homogeneity. The results are also compared with those of a passive simulation technique based on the use of spires.

• 디지털콘텐츠
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• 8호통권135호
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• pp.54-59
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• 2004

인터넷 포털 대전쟁이 시작됐다. 한국 통신시장을 사실상 양분하고 있는 KT와 SK텔레콤이 인터넷 포털 사업에 포문을 열고 시장재편을 위한 움직임을 본격화하면서다. KTH의‘파란’이 최근 공식 오픈하면서 포털 시장에 파란을 예고하고 있고, 미니홈피로 돌풍을 일으킨 싸이월드를 합병한 SK커뮤니케이션즈의 네이트닷컴은 업계 선두를 넘보고 있다. 여기에 최근 한발 물러서긴 했으나 영화.음악.게임 콘텐츠에서 막강한 지배력을 갖춘 CJ까지 가세해 벤처 텃밭이었던 포털 시장에 대기업을 등에 업은 공룡 등장을 알렸다. 하지만 터줏대감인 NHN.다음.야후코리아 등 전문 포털업체들도 쉽게 물러서지 않을 태세다. 이들 업체들은 검색, 커뮤니티, 메일 등 다양한 신규 서비스를 경쟁적으로 선보이며 전면전을 준비하고 있다. 이에 따라 하반기 포털 시장은 기존 인터넷 전문 포털들과 시장지배력을 갖춘 대기업 포털간의 피할 수 없는 진검승부가 예고되고 있다. 하반기 혈전이 예고되는 공룡기업과 벤처의 싸움이‘골리앗과 다윗’싸움이 될지,‘ 고래싸움에 새우등 터지는’격이 될지 주목된다.

• 한국세라믹학회지
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• 제40권11호
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• pp.1027-1046
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• 2003

Nanostructured materials can be engineered by the controlled assembly of several suitable nano-objects as the building blocks. While, materials properties are determined by their atomic and molecular constituents and structure, their functionalities emerge when the microstructure of these early ensembles is in the nanometer regime. The properties and functionalities of these ensembles may be different as their size grows from the nano-regime to the micron regime and bulk structures. Nanotechnology, offers a unique possibility to manipulate the properties through the fabrication of materials using the nano-objects as building blocks. Nanotechnology is therefore considered an enabling technology by which existing materials, virtually all man-made materials, can acquire novel properties and functionalities making them suitable for numerous novel applications varying from structural and functional to advanced biomedical in-vivo and in-vitro applications.

• Computers and Concrete
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• 제4권1호
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• pp.67-82
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• 2007

The discrete crack-concept is applied to study the 3D propagation of tensile-dominated failure in plain concrete. To this end the Partition of Unity Finite Element Method (PUFEM) is utilized and the strong discontinuity approach is followed. A consistent linearized implementation of the PUFEM is combined with a predictor-corrector algorithm to track the crack path, which leads to a robust numerical description of concrete cracking. The proposed concept is applied to study concrete failure during the PCT3D test and the predicted numerical results are compared to experimental data. The proposed numerical concept provides a clear interface for constitutive models and allows an investigation of their impact on concrete cracking under 3D conditions, which is of significant scientific interests to interpret results from 3D experiments.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1996년도 하계학술대회 논문집 B
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• pp.1301-1303
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• 1996

A new automatic frequency control(AFC) tracking algorithm, which we call a rotational decision directed AFC(RDDAFC) is proposed for QPSK demodulation at the digital direct broadcasting satellite(DBS). In order to prevent the presence of the residual phase difference between symbols received at k and k-l by the CPAFC[1] as well as the AFC based on $tan^{-1}$ circuit[2], the RDDAFC rotates the decision boundary for the kth received symbol by the frequency detector output of the (k-1)th received symbol before passing through the cross product discriminator. Test results show that the total pull-in time of the RDDAFC and PLL was 0.13msec under a carrier frequency offset of 2.4MHz when S/N equals 2dB.

• 한국멀티미디어학회논문지
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• 제21권12호
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• pp.1473-1480
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• 2018

The extraction and recognition of human motion characteristics need to combine biometrics to determine and judge human behavior in the movement and distinguish individual identities. The so-called biometric technology, the specific operation is the use of the body's inherent biological characteristics of individual identity authentication, the most noteworthy feature is the invariance and uniqueness. In the past, the behavior recognition technology based on the single characteristic was too restrictive, in this paper, we proposed a mixed feature which combined global silhouette feature and local optical flow feature, and this combined representation was used for human action recognition. And we will use the KTH database to train and test the recognition system. Experiments have been very desirable results.