• Title/Summary/Keyword: 2 단계축소법

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Numerical Modeling of Local Scour Around a Coffer Dam (물막이댐 주변에서의 국부세굴현상 모의)

  • Noh, Joon woo;Kim, Woo Gu
    • Proceedings of the Korea Water Resources Association Conference
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    • 2004.05b
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    • pp.419-423
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    • 2004
  • 하상변동은 유속에 의해 얻어지는 전단력에 직접적으로 영향을 받게 된다. 특히 교대나 교각, 그 밖에 수제공 등을 비롯한 수공구조물의 설치에 의하여 흐름단면이 급격히 감소되는 구간에서는 이러한 현상이 매우 활발하게 일어나게 되는데 이는 국부세굴의 직접적인 원인이 되기도 한다. 본 논문에서는 단면축소에 기인한 유속증가에 의해서 발생되는 국부세굴현상을 2차원 유한요소 모델을 사용하여 모의하고 주변의 전반적인 하상변동현상을 규명해 보았다. 먼저 2차원 흐름모형으로부터 유속성분을 구하고 전단력을 구한 다음 소류사 이동공식을 적용한 하상토 보존방정식을 풀이함으로써 국부세굴에 따른 하상의 변동을 수치모델로 예측할 수 있게 된다. 본 논문에서는 유한요소법을 이용, 하상토 보존방정식을 계산한 다음 일정시간동안 모델수행을 통해서 변동이 거의 없을 때까지 하상의 변동사항을 순차적으로 모의하고 예측해 보았다. 적합한 구간을 선정하여 단면축소에 기인한 유속증가로 인한 국부 세굴을 모의하기 위하여 본 모델을 개발, 적용하였다. 미국 미시시피 강에서 Lock & Dam No. 26을 교체하는 제 1단계 작업 중 물막이댐 건설로 인하여 흐름단면이 약 $50\%$ 감소하게 된다. 주로 단면축소 구간을 적용대상으로 선정하여 물막이댐 주변의 하상변동을 모의한 다음 실제 관측치와 비교하여 본 모델의 효용성을 입증하였다. 모형은 기본적으로 유한요소법을 이용해서 하상토 보존 방정식을 풀이한 것으로 van Rijn 소류사 이동공식을 적용하였다. 세굴현상에 기인한 수심증가로 인한 전단력 감소현상도 흐름의 연속조건을 도입하여 모의가능 하게끔 작성하였다.. 상대적으로 적은 것으로 분석되었다. 이번 연구를 통하여 WEP 모형이 유역 물순환 해석에 적절한 모형임을 확인할 수 있었으면, 향후 청계천 유역의 물리적 특성에 대한 매개변수와 인공계 물순환 자료의 보완을 통해 보다 향상된 모의가 가능할 것으로 판단된다. 하였던 Cd과 Mg이 Ca 및 Ca과 vitamin D의 동시(同時) 급여(給與)로 감소(減少)하였고 Cu는 전체적(金體的)으로 변화(變化)가 없었으며 Zn은 Cd 급여(給與)로 감소(減少)하였으나 Ca과 vitamin D의 급여(給與)에 의하여 증가(增加)하였고 Ca은 Ca과 viamin D의 급여(給輿)로 유의(有意)하게 증가(增加)하였다. 신장(腎臟)중의 무기질(無機質) 함량(含量)은 Cd급여(給輿)로 Cu, Mg은 감소(滅少)하였으나 Ca, Zn은 변화(變化)가 없었고 Ca 및 Ca과 Vitamin D의 급여(給與)로 Cd, CU, Zn은 증가(增加)하였다.ce area)는 수술 전100.8$\pm$25.6 mm/$m^{2}$에서 79.3$\pm$ 15.8 mm/$m^{2}$로 감소한 소견을 보였다. 승모판 성형술은 전 승모판엽 탈출증이 있는 두 환아에서 동시에 시행하였다. 수술 후 1년 내 시행한 심초음파에서 모든 환아에서 단지 경등도 이하의 승모판 폐쇄 부전 소견을 보였다. 수술 후 조기 사망은 없었으며, 합병증으로는 유미흉이 한 명에서 있었다. 술 후 10개월째 허혈성 확장성 심근증이 호전되지 않아 Dor 술식을 시행한 후 사망한 예를 제외한 나머지 6명은 특이 증상 없이 정상 생활 중이다 결론:

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Binary classification by the combination of Adaboost and feature extraction methods (특징 추출 알고리즘과 Adaboost를 이용한 이진분류기)

  • Ham, Seaung-Lok;Kwak, No-Jun
    • Journal of the Institute of Electronics Engineers of Korea CI
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    • v.49 no.4
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    • pp.42-53
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    • 2012
  • In pattern recognition and machine learning society, classification has been a classical problem and the most widely researched area. Adaptive boosting also known as Adaboost has been successfully applied to binary classification problems. It is a kind of boosting algorithm capable of constructing a strong classifier through a weighted combination of weak classifiers. On the other hand, the PCA and LDA algorithms are the most popular linear feature extraction methods used mainly for dimensionality reduction. In this paper, the combination of Adaboost and feature extraction methods is proposed for efficient classification of two class data. Conventionally, in classification problems, the roles of feature extraction and classification have been distinct, i.e., a feature extraction method and a classifier are applied sequentially to classify input variable into several categories. In this paper, these two steps are combined into one resulting in a good classification performance. More specifically, each projection vector is treated as a weak classifier in Adaboost algorithm to constitute a strong classifier for binary classification problems. The proposed algorithm is applied to UCI dataset and FRGC dataset and showed better recognition rates than sequential application of feature extraction and classification methods.

Ultra-Rapid Real-Time PCR for the Detection of Human Immunodeficiency Virus (HIV) (Ultra Rapid Real-Time PCR에 의한 Human Immunodeficiency Virus (HIV)의 신속진단법)

  • Lee, Dong-Woo;Kim, Eul-Hwan;Yoo, Mi-Sun;Han, Sang-Hoon;Yoon, Byoung-Su
    • Korean Journal of Microbiology
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    • v.43 no.2
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    • pp.91-99
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    • 2007
  • For the detection of Human Immunodeficiency Virus (HIV), multiple and ultra-rapid real-time PCR methods were developed. The target DNA sequences were deduced from HIV-1 specific 495bp partial env gene (gi_1184090) and from HIV-2 specific 294 bp partial env gene (gi_1332355), and were synthesized by using PCR-based gene synthesis on the reason of safety. Ultra-rapid real-time PCR was performed by $Genspector^{TM}$ using microchip-based, $1\;{\mu}l$ of reaction volume with extremely short time in each 3 step in PCR. The detection including DNA-amplification and melting temperature analysis was completed inner 15 minutes. The HIV-1 specific 117 bp-long and HIV-2 specific 119 bp-long PCR products were successfully amplified from minimum of template,2.3 molecules of each env gene. This kind of real-time PCR was designated as ultra-rapid real-time PCR in this study and it could be applied not only an alternative detection method against HIV, but also other pathogens using PCR-based detection.

Eigen Palmprint Identification Algorithm using PCA(Principal Components Analysis) (주성분 분석법을 이용한 고유장문 인식 알고리즘)

  • Noh Jin-Soo;Rhee Kang-Hyeon
    • Journal of the Institute of Electronics Engineers of Korea CI
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    • v.43 no.3 s.309
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    • pp.82-89
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    • 2006
  • Palmprint-based personal identification system, as a new member in the biometrics system family, has become an active research topic in recent years. Although lots of methods have been made, how to represent palmprint for effective classification is still an open problem and conducting researches. In this paper, the palmprint classification and recognition method based on PCA (Principal Components Analysis) using the dimension reduction of singular vector is proposed. And the 135dpi palmprint image which is obtained by the palmprint acquisition device is used for the effectual palmprint recognition system. The proposed system is consists of the palmprint acquisition device, DB generation algorithm and the palmprint recognition algorithm. The palmprint recognition step is limited 2 times. As a results GAR and FAR are 98.5% and 0.036%.

Scientific study for the standardization of the preparation methods for SULNONGTANG. (설농탕 조리법의 표준화를 위한 조리과학적 연구 -제1보 : 전래설농탕과 시판설농탕의 영양학적 비교연구-)

  • 임희수;윤서석
    • Korean journal of food and cookery science
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    • v.3 no.1
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    • pp.37-46
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    • 1987
  • SULNONGTANG is a kind of “goomkok”-korean typical soup made with beef, tone and organs, and is belived to be as a good source of portein and calcium, but there is no standard formulation for that. In order to set up the standard formulation of SULNONGTANG cooking method, I have performed a nutritional analysis of change in the components of SULNONGTANG, which contained the proximate composition, free amino acids, nucleotides, cholesterol, calium, phosphorus and iron. The conventional SULNONGTANG were cooked by conventional methods varing cooking time and ingredient. And also the current Market SULNONGTANG were cooked by the same methods for conventional SULNONGTANG and adding beef's head, hooves or knee tones. The result obtained in this study were as fallows: 1. In case of conventional SULNONGTANG, the most desirable cooking time was from 12 to 18 hours, the preparation method for group A was the best to maintain the optimal amount of nutrients and 5'-IMP. 2. In Market SULNONGTANG, nutritional contents were poorer than that of conventional SULNONGTANG. When the beef's head was added to the Market SULNONGTANG, nutritional status were more desirable than those added hooves or knee bones.

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Optimal Design of the Stacking Sequence on a Composite Fan Blade Using Lamination Parameter (적층 파라미터를 활용한 복합재 팬 블레이드의 적층 패턴 최적설계)

  • Sung, Yoonju;Jun, Yongun;Park, Jungsun
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.48 no.6
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    • pp.411-418
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    • 2020
  • In this paper, approximation and optimization methods are proposed for the structural performance of the composite fan blade. Using these methods, we perform the optimal design of the stacking sequence to maximize stiffnesses without changing the mass and the geometric shape of the composite fan blade. In this study, the lamination parameters are introduced to reduce the design variables and space. From the characteristics of lamination parameters, we generate response surface model having a high fitness value. Considering the requirements of the optimal stacking sequence, the multi-objective optimization problem is formulated. We apply the two-step optimization method that combines gradient-based method and genetic algorithm for efficient search of an optimal solution. Finally, the finite element analysis results of the initial and the optimized model are compared to validate the approximation and optimization methods based on the lamination parameters.

A Robust Design of Response Surface Methods (반응표면방법론에서의 강건한 실험계획)

  • 임용빈;오만숙
    • The Korean Journal of Applied Statistics
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    • v.15 no.2
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    • pp.395-403
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    • 2002
  • In the third phase of the response surface methods, the first-order model is assumed and the curvature of the response surface is checked with a fractional factorial design augmented by centre runs. We further assume that a true model is a quadratic polynomial. To choose an optimal design, Box and Draper(1959) suggested the use of an average mean squared error (AMSE), an average of MSE of y(x) over the region of interest R. The AMSE can be partitioned into the average prediction variance (APV) and average squared bias (ASB). Since AMSE is a function of design moments, region moments and a standardized vector of parameters, it is not possible to select the design that minimizes AMSE. As a practical alternative, Box and Draper(1959) proposed minimum bias design which minimize ASB and showed that factorial design points are shrunk toward the origin for a minimum bias design. In this paper we propose a robust AMSE design which maximizes the minimum efficiency of the design with respect to a standardized vector of parameters.

Image Reconstruction Using Poisson Model Screened from Image Gradient (이미지 기울기에서 선별된 포아송 모델을 이용한 이미지 재구성)

  • Kim, Yong-Gil
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.18 no.2
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    • pp.117-123
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    • 2018
  • In this study, we suggest a fast image reconstruction scheme using Poisson equation from image gradient domain. In this approach, using the Poisson equation, a guided vector field is created by employing source and target images within a selected region at the first step. Next, the guided vector is used in generating the result image. We analyze the problem of reconstructing a two-dimensional function that approximates a set of desired gradients and a data term. The joined data and gradients are able to work like modifying the image gradients while staying close to the original image. Starting with this formulation, we have a screened Poisson equation known in physics. This equation leads to an efficient solution to the problem in FFT domain. It represents the spatial filters that solve the two-dimensional screened Poisson model and shows gradient scaling to be a well-defined sharpen filter that generalizes Laplace sharpening. We demonstrate the results using a discrete cosine transformation based this Poisson model.

A Study on the Web Accessibility of University Library Web Sites (국내 대학 도서관 홈페이지의 웹 접근성 실태에 대한 연구)

  • Kim, Young-Gon;Oh, Chang-Gyu
    • Journal of the Korean Society for information Management
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    • v.28 no.3
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    • pp.197-217
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    • 2011
  • Web accessibility refers to the practice of providing equal access to web sites to people without and with disability. This study aims to investigate the web content accessibility of 153 university libraries in Korea, and further suggest the approach to implement an effective university library web site to meet Korean Web Content Accessibility Guidelines(KWCAG). Survey was conducted with two steps. The first step was to find out the general level of web accessibility of all university library web sites using an automatic appraisal tool, KADO-WAH2.0, and the detailed examination of web accessibility check items was limited to 19 web sites which proved excellent in automatic appraisal. Regretfully, the result says that there is no perfect web site. Therefore every university library is advisable to make good use of the findings to meet all the requirements of KWCAG. In particular, the basic requirements, such as voice service, resizing and highlighting text, must be fulfilled by priority and to almost all contents.

The Changes of Coastal Water Level due to the Development of Mokpo Harbor and Construction of Daebul Industrial Complex (목포항 개발 및 대불 산업단지 조성에 따른 연안해역 해면변화)

  • 정명선;이중우
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • 1991.06a
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    • pp.37-44
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    • 1991
  • 영산강 하구언 방조제의 건설로 인한 항만 및 이의 인접해역 해면의 변화는 예상한 바 있으며 실제 여러개소에서 월 2회정도의 주기로 목포 구항부근 상업지역에서 해면상승에 따라 주기적으로 침수되는 현상이 나타나고 있다 목포항의 영산강 하구언 방조제 조성으로 인한 조류성분중 최고기록을 가진 수로에서는 6kts 정도로 감소된 것으로 보고되고 있으나 주위자연환경 변화에 따른 수면 상승 및 해수면의 주기적인 변화 등에 대한 상세한 언급 및 깊이 있는 분석은 회피되어왔다. 수자원의 효율적관리를 위해 하구언 방조제는 이미 건설되었고 앞으로 대규모의 항만개발과 대불산업단지조성을 위해 추가 3개의 만입해안해역에 댐으로 해역을 막아 매립공사를 추진하고 있다 그러나 이 지역에 대한 분석은 타당성의 여부만을 강조한 상업적 용역이 이루어지고 있고 장래 개발에 대해 학술적이고 실질적인 문제점 추출과 해결방아네 대해서는 무시하거나 경시한 바가 많다 더구나 태풍 저기압 등과 같은 자연재해를 고려한 분석은 시도되지 못하고 있다 따라서 개발전후의 현상에 대한 상세한 자료 및 현장 조사와 극한 상태를 고려하여 개발에 따른 수위상승 부진동, 조류 수질등 이해역의 변화요소를 수집하고 분석하며 과학적 접근방법에 기초를 둔 수치모델의 실험을 포함하여 현장관측 및 측정자료를 검증하는 것이 필수적이라고 사료되어 종합분석의 한단계로 여기서는 하구언 및 하구간척(Land Reclamatic of Estuary barren)으로 해역축소에 따른 해면변화의 실제현상을 조사하여 정리하고 이를 수치모델을 통해 시뮬레이션하여 보았다 이는 종합개발의 좋은 기초자료로 이용됨은 물론이로 이지역의 개발에 기여할 것으로본다.적절하게 가정된 지반의 응력-변형률 관계와 간극수압특성에 의하여 고려되었다. 그 결과 응력 및 변위가 심하게 발생하는 지역은 황색 점토층이었으며 이로부터 황색 점토층에서 부터 파괴면이 생성되어 다른 지역으로 전파되었음을 유추할 수 있었다.form trap with 2.88[eV] deep of injected space charge from the chathode in the crystaline regions. The origin of ${\alpha}$$_2$ peak was regarded as the detrapping process of ions trapped with 0.9[eV] deep originated from impurity-ion remained in the specimen during production process of the material, in the crystalline regions. The origin of ${\beta}$ peak was concluded to be due to the depolarization process of "C=0"dipole with the activation energy of 0.75[eV] in the amorphous regions. The origin of ${\gamma}$ peak was responsible to the process combined with the depolarization of "CH$_3$", chain segment, with the activation energy of ca

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