• Food Science and Biotechnology
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• 제16권1호
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• pp.23-28
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• 2007

A linear correlation was found by stepwise multiple regression analysis between the sensory score of barley bran sauce aroma and the absolute gas chromatogram (GC) data transformed with square root. In spite of highly significant relationship between the quantity of the peak and the sensory score, it is difficult to estimate the aroma quality of barley bran sauce samples on the basis of only one peak. Peak 29 (methyl 9,12,15-octadecatrienoate) contributed most to the aroma of barley bran sauce. This was followed by 27 (methyl 9,12-octadecadienoate), 28 (ethyl 9,12-octadecadienoate), 12 (phenyl acetaldehyde), and 9 (methyl furfural) in terms of absolute value. When it was calculated using absolute value transformed by square root, peak 28 (ethyl 9,12-octadecadienoate) made the highest contribution to the aroma of barley bran sauce of among the peaks. It was followed by 31 (9,12-octadecadienoic acid), 27 (methyl 9,12-octadecadienoate), 12 (phenyl acetaldehyde), and 29 (methyl 9,12,15-octadecatrienoate).

• 한국정보과학회논문지:소프트웨어및응용
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• 제30권5_6호
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• pp.444-453
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• 2003

최근 생명공학(BT)에 대한 관심이 집중되면서, 새로운 생리활성 물질을 찾거나 유전자 정보를 분석하기 위한 목적으로 전기영동 젤의 영상 분석 기술에 대한 요구가 급증하고 있다. 이를 위해서는 젤 영상의 레인에서 각 밴드의 위치와 양을 정확히 측정해야 한다. 기존 연구에서는 주로 레인의 프로파일에서 피크를 탐색하는 접근방법을 사용하는데, 이 피크의 위치는 밴드에 있는 최대 자기 화소의 위치도 아니고 더욱이 밴드 무게중심의 위치도 아니기 때문에 밴드의 대표 위치로 인정하기 어렵다. 또한, 피크 추출을 쉽게 하기 위해 다양한 영상 향상 처리를 적용하기 때문에 밴드의 양을 측정하기에는 부적절한 경우가 많다. 본 논문에서는 영상의 상대적인 밝기를 변화시키지 않으면서 먼저 밴드의 영역을 추출한 후, 밴드 영역의 밝기 합으로 양을 구하고 이의 무게중심을 밴드 위치로 정하는 방식을 채택한다. 실제로, 먼저 젤 영상 히스토그램에 엔트로피기반 임계치를 설정하여 레인을 추출한 후, 밴드 영역 추출을 위해 서로 다른 세 가지 방법을 시도한다. 첫째, 추출된 레인을 이등분하는 중심선을 탐색하여 피크와 밸리를 찾고, 피크의 상하 밸리를 각 밴드의 최소 포함 박스영역으로 지정하는 방법(MER), 둘째, 앞의 방법에서와 같이 구한 피크를 영역 성장의 시드로 사용하여 이웃하는 밴드와의 중첩을 해결하면서 밴드 영역을 추출하는 방법(RG-1), 셋째, 이와 달리 레인을 삼등분하는 두 탐색선에서 피크를 찾고 동일한 밴드에 속하는 피크 쌍을 결정한 후 영역을 성장하는 방법(RG-2)을 제안한다. 이상의 세 방법을 비교하기 위해 밴드의 위치 및 양을 측정한 결과, 밴드 위치의 평균 오차는 레인의 길이를 단위 크기로 정규화 할 때, MER 방법이 6%, RG-1 방법이 3%, RG-2 방법이 1%로 나타났다. 또한, 밴드 양의 평균 오차는 레인 내 밴드들의 양의 합을 단위 크기로 정규화 할 때, MER 방법이 8%, RG-1 방법이 5%, RG-2 방법이 2%로 나타났다. 결과적으로, RG-2 방법이 밴드의 위치 및 양 추출에 있어서 정확도가 가장 높은 것으로 판명되었다.

• 한국인터넷방송통신학회논문지
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• 제8권6호
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• pp.153-157
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• 2008

최근 산업사회에서 널리 쓰이는 전자소자들은 다층구조로 제작되고 있는 실정이며 이러한 소자의 보이지 않는 층에 대한 해석은 비파괴 검사에서 중요한 일이다. 따라서 본 논문에서는 접착층이 존재하는 다층구조물에 초음파를 입사시켰을 때 반사되는 신호를 디지털 신호처리하여 가시도를 개선하였다. 이를 위하여 다층구조물에서 반사된 신호를 전력 켑스트럼 처리하여 각층에서 나타난 첫 번째 피크와 두 번째 피크를 구할 수 있었다. 실험을 위하여 일정한 두께를 갖는 에폭시층이 존재하는 다층구조물을 형성하였고 초음파 펄스-에코 방법에 의하여 얻어진 반사신호의 가시도를 개선하기 위해 전력 켑스트럼 처리하였다.

• Journal of Mechanical Science and Technology
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• 제18권11호
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• pp.2042-2048
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• 2004

A molecular dynamics study has been conducted on an external-force-field-induced isothermal crystallization process of amorphous structures as a new low-temperature athermal crystallization process. An external cyclic-force field with a dc bias is imposed on molecules selected randomly in an amorphous-phase of argon. Multiple peaks smoothed out in the radial distribution functions for amorphous states appear very clearly during the crystallization process that cannot be achieved otherwise. When the amorphous material is locally exposed to an external force field, crystallization starts and propagates from the interfacial region and crystallization growth rates can be estimated.

• 해양환경안전학회지
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• 제5권2호
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• pp.35-44
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• 1999

High negative pressure coefficient is formed in the corner of the bluff body structures. For many curtain wall designers this phenomena is of interest because this high negative pressure coefficient is adopted in structural calculation. The present study is aimed to investigate shedding vortex characteristics of two-dimensional rectangular prism flow. Unsteady calculation by finite difference method based upon SOLA is carried out for three aspect ratios(1:1, 1:2, 1:3) of Re=10$^4$ in viscous incompressible flow within infinite domain. Fluctuation of velocity components at various pick-up points and time variation of drag and lift coefficients are analysed by FFT method to reveal shedding vortex frequency patterns. At aspect ratio 1:1, one primary Strouhal number appears for about all pick-up points. At aspect ratio 1:2, two representative Strouhal numbers are classified by pick-up positions and their flows show two different reattachment patterns. For aspect ratio 1:3, frequency spectrum maintains multiple peaks.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1987년도 전기.전자공학 학술대회 논문집(II)
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• pp.1090-1093
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• 1987

In this paper, we describe the principle, the procedure and calculation of the measurement. Finally the experimental results are shown and discussions are given. Interpreting of a skewed symmetry in the image as a real symmetry in the 3-D space provides strong constraints on 3-D sharp analysis. In order to apply the idea to the real scene, a method is presented which can find the skewed symmetry in the image of the skewed symmetrical object, even if it is occluded partly. there parameters of the skewed symmetry are estimated by examining peaks in two 2-D hough spaces, onto which the parameters of all candidates of boundary line segments for skewed symmetries are voted. The method is characterized with a small amount of computation, finding of multiple symmetry axes and inference of the occluded parts of the symmetrical object.

• 한국소음진동공학회논문집
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• 제11권4호
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• pp.43-51
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• 2001

An experimental modal analysis is the process to identify structure's dynamic characteristics such as resonant frequencies, damping values and mode shapes. An experimental model was made of stainless steel in the shape of a circular cylindrical shell and installed on the test bed with jigs. For investigating vibrational characteristics of the continuous circular cylindrical shell with intermediate supports, modal testing is performed by using impact hammer, accelerometer and 8-channel FFT analyzer. The frequency response function(FRF) measurements are also made on the experimental model within the frequency range from 0 to 4kHz. Modal parameters are identified from resonant peaks in the FRF's and animated deformation patterns associated with each of the resonances are shown on a computer screen. The experimental results are compared with analytical and FEA results.

• 한국초전도ㆍ저온공학회논문지
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• 제4권1호
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• pp.50-54
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• 2002

Penetration depth of Nb electrodes in $Nb/A1O_x/Nb$ Josephson junctions has been measured by resistive method. For a given applied field, the total flux through the junction is temperature dependent because the penetration depth of Nb electrode varies with temperature. If the total flux equals an integral multiple of the flux quantum at certain temperatures, resistive peaks appear at those temperatures. The penetration depth of Nb can be determined by applying the above condition, The temperature dependence of penetration depth was found to be well described by the two-fluid model.

• Journal of Ship and Ocean Technology
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• 제8권1호
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• pp.10-30
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• 2004

High-fidelity RANS simulations are presented for a ducted marine propulsor, including verification ＆ validation (V＆V) using available experimental fluid dynamics (EFD) data. CFDSHIP-IOWA is used with $\textsc{k}-\omega$ turbulence model and extensions for relative rotating coordinate system and Chimera overset grids. The mesh interpolation code PEGASUS is used for the exchange of the flow information between the overset grids. Intervals V＆V for thrust, torque, and profile averaged radial velocity just downstream of rotor tip are reasonable in comparison with previous results. Flow pattern displays interaction and merging of tip-leakage and trailing edge vortices. In interaction region, multiple peaks and vorticity are smaller, whereas in merging region, better agreement with EFD. Tip-leakage vortex core position, size, circulation, and cavitation patterns for $\sigma=5$ also show a good agreement with EFD, although vortex core size is larger and circulation in interaction region is smaller.

• Korean Journal of Hydrosciences
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• 제2권
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• pp.1-12
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• 1991

To estimate the peak discharge from the small rural watersheds, 53 storm events of seven small watersheds from 1972 to 1989 were selected and were analyzed by the multiple regression technique. The peak values by the new prediction method developed in this study were also compared to the real data of Banwol Basins and the estimated peaks of the several watersheds which were analyzed by the Korean engineering companies. These values were also compared to the results from the other method, i.e. the Rational Method, the Kajiyama Method, the Nakayasu Unit Hydrograph companies. Through Method, the Area Routing Method, etc., which are favored by the Korean engineering companies. Through these comparisons, it is proved that the proposed method may be used for day-to-day use without any problem. However, there should be some modifications and improvements as more data are available in the future.