• 제목/요약/키워드: numerical methods

검색결과 5,297건 처리시간 0.032초

전진선택법에 의해 선택된 부분 상관관계의 유전자들을 이용한 암 분류 (Classifying Cancer Using Partially Correlated Genes Selected by Forward Selection Method)

  • 유시호;조성배
    • 대한전자공학회논문지SP
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    • 제41권3호
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    • pp.83-92
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    • 2004
  • 유전 발현 데이터는 생명체의 특정 조직에서 채취한 샘플을 마이크로어레이상에서 측정한 것으로, 유전자들의 발현 정도가 수치로 나타난 데이터이다. 일반적으로 정상조직과 이상조직에서 관련 유전자들의 발현 정도는 차이를 보이기 때문에 유전 발현 데이터를 통하여 암을 분류할 수 있다. 그러나 분류에 모든 유전자가 관여하지는 않으므로 효율적인 암의 분류를 위해서는 관련성 있는 소수의 유전자만을 선별해내는 작업인 특징선택 방법이 필요하다. 본 논문에서는 회귀분석의 변수선택방법중 하나인 전진 선택법(forward selection method)을 사용하여 유전자들을 선하고 분류하는 방법을 제안한다. 이 방법은 선택되는 유전자들의 중복된 정보를 최소화시켜 암의 분류에 있어 보다 효과적인 유전자 선택을 한다. 실험데이터는 대장암 데이터(Colon cancer dataset)를 사용하였고, 분류기는 k-최근접 이웃(KNN)을 사용하였다. 이 방법과 상관계수를 이용한 특징 선택방법인 피어슨 상관계수와 스피어맨 상관계수방법과 비교해본 결과 전진 선택법에 의한 특징선택 방법이 암의 분류에 있어서 더 효과적인 유전자 선택을 한다는 사실을 확인하였다. 실험결과 90.3%의 높은 인식률을 보였다. 추가적으로 림프종 데이터에 대한 실험을 하였고, 그 결과 전진 선택법의 유용성을 확인할 수 있었다.

색의 일관성을 고려한 색상 보간 (Color Demosaicing Algorithm Considering Color Constancy)

  • 김창원;오현묵;강문기
    • 대한전자공학회논문지SP
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    • 제47권3호
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    • pp.1-10
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    • 2010
  • 본 논문은 카메라 영상 처리에서 중요한 부분인 색상 보간과 자동 화이트 조절을 동시에 수행하는 방법을 제안한다. 대부분의 자동 화이트 조절은 색상 보간 후에 수행이 되기 때문에 색상 보간의 결과에 영향을 받는다. 자동 화이트 조절의 성능을 높이기 위해서 색상 보간 수행 중에 색의 일관성이 고려된다. 자동 화이트 조절 이득 계산과 색상 보간의 방향 결정을 위한 초기 추정치를 테일러 시리즈를 이용하여 상하좌우 방향으로 구한다. 미리 정의된 무채색 영역을 이용하여 에지 기반 자동 화이트 조절을 수행한다. 에지 기반 자동 화이트 조절의 이득을 계산하고 색상 보간의 성능을 높이기 위해서 베이어 데이터의 각 화소에서 평탄, 에지, 패턴 에지 영역으로 구분한다. 색상 보간은 초기 추정치 중에서 국부 분산을 사용하여 보간 오류의 발생을 최소화하는 방향으로 수행한다. R과 B 색상은 보간된 G 색상과 색의 일관성이 고려된 색차값을 이용해서 쉽게 보간된다. 제안된 알고리즘은 기존 알고리즘에 비해 수치적 및 영상의 화질 면에서 모두 뛰어난 결과를 보임을 실험을 통해 확인 할 수 있다.

Cytogenetic Profile of De Novo B lineage Acute Lymphoblastic Leukemia: Determination of Frequency, Distribution Pattern and Identification of Rare and Novel Chromosomal Aberrations in Indian Patients

  • Bhandari, Prerana;Ahmad, Firoz;Dalvi, Rupa;Koppaka, Neeraja;Kokate, Prajakta;Das, Bibhu Ranjan;Mandava, Swarna
    • Asian Pacific Journal of Cancer Prevention
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    • 제16권16호
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    • pp.7219-7229
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    • 2015
  • Background: Chromosomal aberrations identified in acute lymphoblastic leukemia (ALL) have an important role in disease diagnosis, prognosis and management. Information on karyotype and associated clinical parameters are essential to physicians for planning cancer control interventions in different geographical regions. Materials and Methods: In this study, we present the overall frequency and distribution patterns of chromosomal aberrations in both children and adult de novo B lineage ALL Indian patients using conventional cytogenetics, interphase FISH and multiplex RT-PCR. Results: Among the 215 subjects, cytogenetic results were achieved in 172 (80%) patients; normal karyotype represented 37.2% and abnormal 62.8% with a distribution as follows: 15.3% hypodiploidy; 10.3% hyperdiploidy; 15.8% t(9;22); 9.8% t(1;19); 3.7% t(12;21); 2.8% t(4;11); 2.8% complex karyotypes. Apart from these, we observed several novel, rare and common chromosomal rearrangements. Also, FISH studies using LSI extra-signal dual-color probes revealed additional structural or numerical changes. Conclusions: These results demonstrate cytogenetic heterogeneity of ALL and confirm that the incidence of chromosomal abnormalities varies considerably. To the best of our knowledge, this is one of the largest reported series of cytogenetic investigations in Indian B-lineage ALL cases. In addition, ongoing cytogenetic studies are warranted in larger groups of B-lineage ALL cases to identify newly acquired chromosomal abnormalities that may contribute to disease diagnosis and management.

Analysis of the variability of deflection of a prestressed composite bridge deck

  • Staquet, Stephanie;Detandt, Henri;Espion, Bernard
    • Steel and Composite Structures
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    • 제4권5호
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    • pp.385-402
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    • 2004
  • Nearly 400 composite railway bridge decks of a new kind belonging to the trough type with U-shaped cross section have been constructed in Belgium over the last fifteen years. The construction of these bridge decks is rather complex with the preflexion of precambered steel girders, the prestressing of a concrete slab and the addition of a 2nd phase concrete. Until now, they have been designed with a classical computation method using a pseudo-elastic analysis with modular ratios. Globally, they perform according to the expectations but variability has been observed between the measured and the computed camber of these bridge decks just after the transfer of prestressing and also at long-term. A statistical analysis of the variability of the relative difference between the measured camber and the computed camber is made for a sample of 36 bridge decks using no less than 10 variables. The most significant variables to explain this variability at prestressing are the ratio between the maximum tensile stress reached in the steel girders during the preflexion and the yield strength and the type of steel girder. For the same sample, the long-term camber under permanent loading is computed by two methods and compared with measurements taken one or two years after the construction. The camber computed by the step-by-step method shows a better agreement with the measured camber than the camber computed by the classical method. The purpose of the paper is to report on the statistical analysis which was used to determine the most significant parameters to consider in the modeling in order to improve the prediction of the behaviour of these composite railway bridge decks.

베이징지역 레스토랑 공간구성요소에 나타난 중국 전통성 표현 특성 연구 (The Characteristics of Chinese Traditionality Expression in View of Spatial Elements at Restaurants in Beijing Area)

  • 원단단;오혜경
    • 한국실내디자인학회논문집
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    • 제25권1호
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    • pp.163-171
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    • 2016
  • The objectives of this study is to analyze the characteristics of Chinese traditionality expression at restaurants in Beijing area. 12 restaurants were selected and visited for the investigation research. The results were as follows. First, traditional reproduction was found mainly manifested through the reproduction of traditional ornaments, in particular, the facade and interior element ornaments. Second, Traditional transformation was mainly manifested in replacement material while changing the shape slightly, or to stretch or shorten prototype shape and other negative deformation methods which did not largely out of the scope of traditional reproduction. Third, Traditional reinterpretation was expressed by abstract, symbol or metaphor on designs, usually people can not directly recognize the traditional archetype. When compare with traditional reproduction or traditional transformation, traditional reinterpretation was relatively fewer, however, in this study the traditional reinterpretation and traditional transformation have same numerical result. Reinterpretation as a positive performance method of traditional modernized, it was encouraging the phenomenon, especially in the ceiling design. Chinese traditional cloud patterns have been three-dimensional and diversification of use. And in the wall design, traditional elements have been extremely simplistic or adopted a wide variety of traditional elements, it may be preferred in diversity. In addition, furniture was tinge traditional elements in modern form, lighting was added symbolize color or picture on the traditional lighting which shape was simplified to emphasize space's traditional. But the facade, sign board, floor, and window element seems the range of variation was not wild, promote more use the positive traditional reinterpretation method.

Therapeutic effect of intraductal irrigation of the salivary gland: A technical report

  • Lee, Chena;Kim, Jo-Eun;Huh, Kyoung-Hoe;Yi, Won-Jin;Heo, Min-Suk;Lee, Sam-Sun;Choi, Soon-Chul
    • Imaging Science in Dentistry
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    • 제47권2호
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    • pp.123-127
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    • 2017
  • Purpose: Obstructive and inflammatory disease often occurs in the major salivary glands, and no predictive treatment has yet been developed for this condition. The aim of this report was to introduce an intraductal irrigation procedure and to illustrate its application to practical patient cases. Materials and Methods: Two patients complaining of pain and swelling in the parotid gland during meals who underwent sialography were diagnosed as having sialodochitis with sialadenitis. Intraductal irrigation was then performed on the parotid gland on the side of the complaint. The irrigation procedure was conducted in the same manner as the sialography procedure, except that saline was used as the filling solution. Symptom severity was evaluated with a numerical rating scale (NRS) at the initial visit and a month after the irrigation. Results: The initial NRS value of patient 1 was 10. The value decreased to 6 and then to 0 after 2 irrigation procedures. The NRS value of patient 2 regarding the symptoms involving the left parotid gland decreased from 4-5 to 1 after 4 irrigation procedures performed at 1-month intervals. Conclusion: Intraductal irrigation of the salivary gland may be a simple, safe, and effective treatment option for patients with obstructive and inflammatory disease of the salivary gland that is capable of resolving their symptoms.

지열 히트펌프 시스템의 데이터 마이닝 기반 성능 예측 기술 (Data Mining-Based Performance Prediction Technology of Geothermal Heat Pump System)

  • 황민혜;박명규;전인기;손병후
    • 대한기계학회논문집 C: 기술과 교육
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    • 제4권1호
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    • pp.27-34
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    • 2016
  • 지열 시스템을 대상으로 데이터 마이닝 기반 성능 예측 모델을 구축하였다. 지열 시스템의 실시간 성능 분석과 예측에 필요한 데이터의 기본 조건을 검토한 후, 데이터베이스의 구조를 설계하였다. 먼저 시스템 성능계수(COP)와 전력 소비량을 분석 대상으로 설정한 후, 이들 물리량의 추출 주기(1분 5분 10분 30분 60분 간격)가 예측 결과에 미치는 영향을 분석하였다. 이어서 범주형과 수치형 의사결정나무 모델을 적용하여 시스템의 성능을 예측하였다. 범주형 의사결정나무 모델을 적용했을 때, 10분 주기의 예측 결과의 정확도는 97.7%로 가장 높았다. 또한 수치형 의사결정나무 분석 결과를 통해 COP가 변하는 순간의 임계값을 찾을 수 있었다. 본 논문에서 제안한 방법은 지열 시스템의 실시간 성능 분석과 운전 상태 등에 적용할 수 있을 것으로 판단된다.

Depiction of concrete structures with seismic separation under faraway fault earthquakes

  • Luo, Liang;Nguyen, Hoang;Alabduljabbar, Hisham;Alaskar, Abdulaziz;Alrshoudi, Fahed;Alyousef, Rayed;Nguyen, Viet-Duc;Dang, Hoang-Minh
    • Advances in concrete construction
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    • 제9권1호
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    • pp.71-82
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    • 2020
  • One of the most suitable methods in structural design is seismic separator. Lead-Rubber Bearing (LRB) is one of the most well-known separation systems which can be used in different types of structures. This system mitigates the earthquake acceleration prior to transferring to the structure efficiently. However, the performance of this system in concrete structures with different heights have not been evaluated thoroughly yet. This paper aims to evaluate the performance of LRB separation system in concrete structures with different heights. For this purpose, three, 16, and 23 story concrete structures are equipped by LRB and exposed to a far-field earthquake. Next, a time history analysis is conducted on each of the structures. Finally, the performance of the concrete structures is compared with each other in the term of their response to the earthquakes and the formation of plastic hinges. The results of the paper show that the rate of change in acceleration response and the ratio of drift along the height of 8 and 23 stories concrete structures are more than those of the 16-stories, and the use of LRB reduces the formation of plastic joints.

방향성 있는 음원이 적용된 음향 포물선 방정식 모델 (Acoustic parabolic equation model with a directional source)

  • 이근화;나영남;손수욱
    • 한국음향학회지
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    • 제39권1호
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    • pp.1-7
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    • 2020
  • 해양에서 음향 포물선 방정식은 거리 의존 환경에서 단일 음원으로부터 음장을 계산하는데 효율적인 방법이다. 그렇지만 실제 문제에서는 종종 방향성 있는 음원을 사용해야하는 필요성이 있다. 본 논문에서는 포물선 방정식 모델에 손쉽게 방향성 있는 음원을 적용할 수 있는 두 가지 방법을 제안한다. 첫 번째 방법은 전 방향음원의 수학적 모델인 Delta 함수를 필터링 하는 것이다. 두 번째 방법은 포물선 방정식의 self-starter 해에 유리함수 필터를 적용하는 방법이다. 후자의 방법은 깊이 방향에 대해 상향 및 하향 음파를 분리하지 못한다는 단점이 있으나 모드 전파를 구현하는데는 유용하다. 검증을 위한 수치 예제가 Pekeris 환경과 심해 환경에서 주어졌다.

Simultaneous Unwrapping Phase and Error Recovery from Inhomogeneity (SUPER) for Quantitative Susceptibility Mapping of the Human Brain

  • Yang, Young-Joong;Yoon, Jong-Hyun;Baek, Hyun-Man;Ahn, Chang-Beom
    • Investigative Magnetic Resonance Imaging
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    • 제22권1호
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    • pp.37-49
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    • 2018
  • Purpose: The effect of global inhomogeneity on quantitative susceptibility mapping (QSM) was investigated. A technique referred to as Simultaneous Unwrapping Phase with Error Recovery from inhomogeneity (SUPER) is suggested as a preprocessing to QSM to remove global field inhomogeneity-induced phase by polynomial fitting. Materials and Methods: The effect of global inhomogeneity on QSM was investigated by numerical simulations. Three types of global inhomogeneity were added to the tissue susceptibility phase, and the root mean square error (RMSE) in the susceptibility map was evaluated. In-vivo QSM imaging with volunteers was carried out for 3.0T and 7.0T MRI systems to demonstrate the efficacy of the proposed method. Results: The SUPER technique removed harmonic and non-harmonic global phases. Previously only the harmonic phase was removed by the background phase removal method. The global phase contained a non-harmonic phase due to various experimental and physiological causes, which degraded a susceptibility map. The RMSE in the susceptibility map increased under the influence of global inhomogeneity; while the error was consistent, irrespective of the global inhomogeneity, if the inhomogeneity was corrected by the SUPER technique. In-vivo QSM imaging with volunteers at 3.0T and 7.0T MRI systems showed better definition in small vascular structures and reduced fluctuation and non-uniformity in the frontal lobes, where field inhomogeneity was more severe. Conclusion: Correcting global inhomogeneity using the SUPER technique is an effective way to obtain an accurate susceptibility map on QSM method. Since the susceptibility variations are small quantities in the brain tissue, correction of the inhomogeneity is an essential element for obtaining an accurate QSM.