• 정보처리학회논문지D
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• 제14D권6호
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• pp.689-700
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• 2007

정보시스템 운영리스크를 최소화하고, 장애시간 동안의 영업기회 손실비용 규모를 줄이기 위해서는 장애의 예방과 사전준비가 필요하다. 그런데 장애가 발생할 경우, 대부분의 기업에서는 장애발생 직후에 대응과 복구 조치를 취하고 있다. 프로그램 개발자나 시스템운영자들은 과거의 경험과 직관에 의존하여 장애를 관리하고 있을 뿐, 장애를 체계적으로 관리하고 사전에 예방하는 사례를 찾아보기가 힘든 실정이다. 본 논문은 정보시스템 운영리스크의 관점에서, 디스크 장애예방을 위한 피해저감모델의 개발에 초점을 맞추었다. 연구모델은 디스크장치에서 정보시스템 운영리스크가 발생하는 위험원인, 그리고 이러한 원인들을 사전에 점검하는 점검주기, 점검에 필요한 운영규정으로 구성된다. 또한 정보시스템 부문의 하드웨어 장애요인 중에서 가장 크게 나타나고 있는 디스크 장애에 대하여 피해저감모델을 적용함으로써 활용 가능성을 보여 준다.

• 항공우주시스템공학회지
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• 제12권4호
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• pp.57-63
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• 2018

적외선 온도 측정 기법은 비접촉식 방법으로 모형의 표면 온도를 가시화할 수 있는 기법이다. 그러나 획득할 수 있는 결과는 2차원 온도 결과로 정량적인 결과를 획득하기에는 한계가 있다. 본 연구는 3차원 매핑 기법을 적외선 온도 측정 기법에 적용하는 것이 목표이다. 풍동 실험은 국방과학연구소에서 보유하고 있는 중형 아음속 풍동에서 수행했으며, 대상 모형은 오자이브 실린더이다. 시험 조건은 유속 20 m/s에서 80 m/s, 받음각은 $0^{\circ}{\sim}90^{\circ}$이다. 3차원 매핑 기법은 마커를 이용하여 실제 모형의 위치정보와 적외선 이미지 상의 위치 정보를 대응시키는 방법을 사용하였다. 그 결과, 모형의 박리점이 이론적인 값과 매우 일치하는 것을 확인하였다.

• 대한전자공학회논문지SP
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• 제47권5호
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• pp.18-24
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• 2010

본 논문에서는 돌비 프로로직 II/IIx를 대체하기 위한 가상 음원 위치 정보 기반의 새로운 메트릭스 디코더 시스템을 제안하고자 한다. 제안하는 신규 메트릭스 디코더는 역행렬 계산을 통해 얻어지는 수동 메트릭스 디코딩부와 수동 메트릭스 디코딩을 통해서 얻은 신호들을 멀티채널 신호의 채널간 이미지 특성에 따라서 적응적으로 가변시키는 능동 메트릭스 디코딩부로 구성된다. 멀티채널 환경에서 채널 간에 형성되는 다수의 이미지는 실제 청각 시스템에 의해서 인지되어 만들어지는 가상의 사운드 이벤트와 연결이 되어 있다. 따라서 이 이미지의 위치와 크기에 기반하여 멀티채널 신호를 적응적으로 가변시키면, 인지적인 관점에서 우수한 성능의 메트릭스 디코더를 설계할 수 있다. 더불어 채널간 분리도를 향상시키기 위해서 비선형 삼각함수의 조합을 사용하였다.

• 한국의상디자인학회지
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• 제16권3호
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• pp.179-189
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• 2014

Peplums have a great advantage in easy styling for wearers to acquire desired physical and reminiscent images depending on the type and where it is placed on the waist line. However, the study of peplum blouses has not yet recognized. This study suggests a baseline data for visual appraisals as a determined key factor is changes. The result of this study as follows: First, peplums published between 2012 through 2014 collections are used for decorative effects on tops or bottoms as the finest decoration details of fashioning women's physical attractiveness. Its application has been extended to various fashion themes such as belts and overskirt that are made of peplum itself. Second, peplums published between 2012 through 2014 collections have close correlation of how the position, shape, and length of peplums are attached on bottoms. Peplum effects are categorized as extension of tops, expansion of bottoms, connections of tops and bottoms, and separation of tops and bottoms. Third, total of seventy nine peplum blouses that are found in the domestic online shopping mall are analyzed. The total length of peplum blouses are generally produced to 56 to 61cm, which is little shorter than or approximately equal to the hip line of women aged in between twenty to twenty four. In addition, the most popular peplum design is made of flare and cutting lines on the waist line and is 45.56% of samples. The most common location of peplums is identified as 3 to 6 cm above the natural waist line or the natural waist line and is 78.47% of samples. Fourth, the key factor of peplum blouse that can significantly influence the visual image is the total length of blouse, position of peplum, and peplum shape.

• Journal of Mechanical Science and Technology
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• 제15권12호
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• pp.1835-1844
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• 2001

The turbulent flow with wake, reattachment and recirculation is a very important problem that is related to vehicle dynamics and aerodynamics. The Smagorinsky Model (SM), the Dynamics Subgrid Scale Model (DSM), and the Lagrangian Dynamic Subgrid Scale Model (LDSM) are used to predict the three-dimensional flow field around a bluff body model. The Reynolds number used is 45,000 based on the bulk velocity and the height of the bluff body. The fully developed turbulent flow, which is generated by the driver part, is used for the inlet boundary condition. The Convective boundary condition is imposed on the outlet boundary condition, and the Spalding wall function is used for the wall boundary condition. We compare the results of each model with the results of the PIV measurement. First of all, the LES predicts flow behavior better than the k-$\xi$ turbulence model. When ew compare various LES models, the DSM and the LDSM agree with the PIV experimental data better than the SM in the complex flow, with the separation and the reattachment at the upper front part of th bluff body. But in the rear part of the bluff body, the SM agrees with the PIV experimental results better than them. In this case, the SM predicts overall flow behavior better than the DSM nd the LDSM.

• 전자공학회논문지C
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• 제36C권1호
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• pp.73-81
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• 1999

본 논문에서는 1-D DCT를 이용한 차량 영상의 번호판 영역 및 번호판의 문자 영역을 효과적으로 분할하는 방법을 제안한다. 차량 영상에서 번호판 영역과 번호판의 문자영역은 일정 크기의 고주파 성분에 의하여 구별될 수 있다. 본 방법은 이러한 고주파 성분을 DCT로써 추출하고, 추출된 고주파 성분에 의하여 번호판 영역과 문자영역을 분리하는 방법을 보인다. 또한 제안된 방법에 대한 타당성을 보이기 위하여, 다양한 영상에 대해 실험하였다. 그 결과, 간단한 전처리 만으로 비교적 정확한 번호판 영역 추출이 가능하였으며, 보다 효과적으로 문자영역을 분리할 수 있음을 확인할 수 있었다.

• 한국정밀공학회지
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• 제27권3호
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• pp.33-40
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• 2010

Multizeros(multiple order zeros) optical beams which belong to the Laguerre-Gaussian beams, have rotational phase and conically-shaped amplitude structures around multizeros points in their phase and amplitude profiles, respectively. Especially, they have their own characteristics that the multizero points do not vanish over free-space propagation. Therefore, they are expected to be adequate for the applications of long-range optical measurement by using their multizero points as optical markers for the deformation sensing. In this paper, fundamental properties of multizeros optical beams for long-range optical measurement applications are investigated and clarified. In particular, the mathematical investigations are described on the characteristics of multizeoros optical beams such as (1) separation of a multizero into isolated single order zeros, (2) topological charge of zeros distribution which are induced by superposing them. And also the outline of a fundamental experiment and its result are explained briefly.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년도 심포지엄 논문집 정보 및 제어부문
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• pp.45-47
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• 2006

Cleft palate is a congenital deformity condition with separation of the two sides of the lip resulting in nose deformity. Evaluation of surgical corrections and outcome assessments for nose deformity due to the cleft lip depends mainly on doctor's subjective judgment. An objective method for evaluation of the condition and surgical outcome of nose deformity due to the cleft palate is needed. This study aimed at objective assessment of a cleft palate nose deformity condition by analyzing the following parameters obtained from photographic images of a cleft palate patients: (1) angle difference between two nostril axes. (2) center of the nostril and distance between two centers. (3) overlapped area of two nostrils, and (4) the overlapped area ratio of the two nostrils. A regression equation of doctor's grades was obtained using the eight parameters. Three plastic surgeons gave us the grades for the each photographic image by 10 increments with maximum grade of 100. The average reproducibility of the grades given by the three plastic surgeons and the three laymen using the developed program was $10.8{\pm}4.6%$ and $7.4{\pm}1.8%$, respectively. Kappa values representing the degree of consensus of the plastic surgeons and the three laymen were 0.43 and 0.83. respectively. Correlation coefficient of the grades evaluated by the surgeons and obtained by the neural network was 0.798. In conclusion. the developed neural network model provided us better reproducibility and much better consensus than doctor's subjective evaluation in addition to objectiveness and easy application.

• 한국가구학회지
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• 제22권3호
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• pp.190-198
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• 2011

This study intended to present a new direction of differentiated and innovative furniture design for small living space overcoming the uniformity of conventional small living. In order to achieve these goals, a new piece of furniture with multi functions useful for such small space has been designed and explained in this study. This new type multi-functional furniture can be utilized as kitchen, dining table, home bar or office stand depending on the user's necessity. In particular, it provides more adaptability to changing life and spatial availabilities for small living space in terms of space division, separation and fusion features. Based on the needs of small living space brought by social changes, the conventional concept of small living space, which divides space by partitions or walls, should be changed into flexible perception of space. Also, this research proposed the features of furniture design for functional shifts in terms of its functional, structural, and systematical aspects. In this respect, space can be regarded as a variable place and the image of space can be differently appreciated by means of shift, functional transition and mobility. That is, small living space can be perceived as kitchen, living space or working space at the same time. In conclusion, the versatile use of limited space can be a solution to the issues related to small living space; the convertible and movable furniture called F4 Island presented in this study can transform such spatially limited space into a space with multiple functions to meet the requirements of its residents.

• 한국주조공학회지
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• 제23권5호
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• pp.276-285
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• 2003

In the undercooled melt of $Pd_{40}Cu_{30}Ni_{10}P_{20}$ alloy, the solidification behavior including nucleation and growth of crystals at the micrometer level has been observed in-situ by use of a confocal scanning laser microscope combined with an infrared image furnace. The $Pd_{40}Cu_{30}Ni_{10}P_{20}$ alloy specimens were cooled from the liquid state to glass transition temperature. 575 K, at various cooling late under a helium gas flow. According to the cooling rate, the morphologies of the solidification front are changed among various types, irregular jog like front, columnar dendritic front, cellular grain, star like shape jog and fine grain, etc. The velocities of the solid-liquid interface are measured to be $10^{-5}{\sim}10^{-8}$ m/s which are at least two orders higher than the theoretical crystal growth rates. Combining the morphologies observed in terms of cooling rates and their solidification behaviors, we conclude that phase separation takes place in the undercooled molten $Pd_{40}Cu_{30}Ni_{10}P_{20}$ alloy. The continuous cooling transformation (CCT) diagram was constructed from solidification onset time at various linear cooling conditions with different rate. The CCT diagram suggests that the critical cooling rate for glassy solidification is about 1.5 K/s, which is in agreement with the previous calorimetric findings.