• 제목/요약/키워드: Background level

검색결과 4,519건 처리시간 0.031초

퍼지 클러스터링을 이용한 확률분포함수 기반의 다중문턱값 선정법 (Selection Method of Multiple Threshold Based on Probability Distribution function Using Fuzzy Clustering)

  • 김경범;정성종
    • 한국정밀공학회지
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    • 제16권5호통권98호
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    • pp.48-57
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    • 1999
  • Applications of thresholding technique are based on the assumption that object and background pixels in a digital image can be distinguished by their gray level values. For the segmentation of more complex images, it is necessary to resort to multiple threshold selection techniques. This paper describes a new method for multiple threshold selection of gray level images which are not clearly distinguishable from the background. The proposed method consists of three main stages. In the first stage, a probability distribution function for a gray level histogram of an image is derived. Cluster points are defined according to the probability distribution function. In the second stage, fuzzy partition matrix of the probability distribution function is generated through the fuzzy clustering process. Finally, elements of the fuzzy partition matrix are classified as clusters according to gray level values by using max-membership method. Boundary values of classified clusters are selected as multiple threshold. In order to verify the performance of the developed algorithm, automatic inspection process of ball grid array is presented.

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도시주부의 가족응집력.적응력이 가정관리 스트레스에 미치는 영향 (The Influence of Family Cohesion and Adaptability on the Stress of Housewives Resulted from Home Management)

  • 이정우
    • 가정과삶의질연구
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    • 제17권3호
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    • pp.63-82
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    • 1999
  • This study has a purpose to provide with the basis reference to decrease the housewives' stress and to improve the quality of family life by investigating the difference in the level of the stress resulted from home management according to background variables family cohesion and adaptability and by finding out relative importance of the variables which affect the stress of housewives resulted from home management. For all above the 550 self-reported questionnaires were distributed to housewives who have at least one child with their spouse in seoul. Finally 433 data were used for the final analysis. The major findings of this study are summarized as follows: First Family cohesion and adaptability show a significant difference by the housewives' education level the number of children communication satisfaction. Second housewives' stress is different significantly in accordance with the state of employment and communication satisfaction. Third it showed the lower the family coh sion and adaptability are the higher the housewives' stress is. And more influential variable of the two on home management stress is family cohesion. Fourth The background variables that influence in home management stress were education level perceived life level and age. Last As a result of looking into relative influence of the variables on the housewives' stress both psychological variable(perceived life level) and family cohesion were important variables in explaining housewives' home management stress.

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Impact of Radiotherapy on Background Parenchymal Enhancement in Breast Magnetic Resonance Imaging

  • Kim, Yun Ju;Kim, Sung Hun;Choi, Byung Gil;Kang, Bong Joo;Kim, Hyeon Sook;Cha, Eun Suk;Song, Byung Joo
    • Asian Pacific Journal of Cancer Prevention
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    • 제15권7호
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    • pp.2939-2943
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    • 2014
  • Background: While many studies have shown that hormones can influence background parenchymal enhancement (BPE) in breast magnetic resonance imaging (MRI), only few have directly address the effect of radiotherapy. The purpose of this study was to evaluate the impact of radiotherapy on BPE in breast MRI. Materials and Methods: A retrospective search identified 62 women with unilateral breast cancer who had a breast MRI both before and after radiotherapy following breast-conserving surgery. In our study, we assumed that systemic therapy affected both breasts equivalently. We rated the level of BPE of both breasts using a four-point categorical scale. A change in the level of BPE prior to and after treatment was compared in the diseased and contralateral breasts. Results: All patients received a 4256 to 6480 cGy dose of whole breast radiotherapy over 3-7 weeks. The mean timing of the follow-up study was 6.6 months after completion of radiotherapy. Although the BPE showed a decrease in both breasts after treatment, there was a significant reduction of BPE in the irradiated breast compared with the contralateral breast (1.18 versus 0.98 average reduction in BPE level, p=0.042). Conclusions: Radiotherapy is associated with decrease in BPE with MRI.

Estimation of Surface Color with Use of Subjective Feeling: On the Influence of Contrast by Complementary Color

  • Sakamoto, Kazuyoshi;Wada, Mitsuyoshi;Min, Byung-Chan
    • 감성과학
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    • 제5권2호
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    • pp.73-78
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    • 2002
  • The unique colors of paper, that is, blue, green, red, and yellow were used in the estimation of color from the subjective feeling. The monochrome with unique color or the unique color surrounded with the background color was presented. subject gazed the monochrome or the unique color, which was tailed target rotor. The target and background color were the complementary color each other. The various ratios of the area of gazed color and background were taken. Subject answered the level of subjective feeling consisted of pair of adjective items for unique color presented. With the use of the subjective feeling for the target color presented, the estimation of the unique color was cai\ulcornerlied out due to Fuzzy theory and neural networks. The results of color difference between unique color presented and the estimated color gave very small value for the case without background, while the results of the case with background color depended on the ratio of area of presented color and background color till the ration of 2:1, The relation showed the Kirschman's law, The color difference saturated In the increase of area of background with the ratio more than 2:1.

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Estimation of surface color with use of subjective feeling: On the influence of contrast by complementary color

  • Sakamoto, Kazuyoshi;Wada, Mitsuyoshi;Min, Byung-Chan
    • 한국감성과학회:학술대회논문집
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    • 한국감성과학회 2002년도 춘계학술대회 논문집
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    • pp.261-265
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    • 2002
  • The unique colors of paper, that is, blue, green, red, and yellow were used in the estimation of color from the subjective feeling. The monochrome with unique color or the unique color surrounded with the background color was presented. Subject gazed the monochrome or the unique color, which was called target color. The target and background color were the complementary color each other. The various ratios of the area of gazed color and background were taken. Subject answered the level of subjective feeling consisted of pair of adjective items for unique color presented. With the use of the subjective feeling fer the target color presented, the estimation of the unique color was carried out due to Fuzzy theory and neural networks. The results of color difference between unique color presented and the estimated color gave very small value for the case without background, while the results of the case with background color depended on the ratio of area of presented color and background color till the ration of 2:1, The relation showed the Kirschman's law. The color difference saturated in the increase of area of background with the ratio more than 2:1.

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용량성 결합 능동 전극의 내부 잡음 분석 (A Study on Intrinsic Noise of Capacitively Coupled Active Electrode)

  • 임용규
    • 융합신호처리학회논문지
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    • 제13권1호
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    • pp.44-49
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    • 2012
  • 간접접촉 심전도 측정(Indirect-Contact ECG)은 일상생활에서의 무구속 무자각 측정에 적합한 새로운 심전도 측정 방법이다. 간접접촉 심전도 측정 에 서 관측되는 큰 배경 잡음을 줄이기 위한 기초 연구로서, 본 연구에서는 간접 접촉 심전도에서 사용되는 용량성 결합 능동 전극(Capacitively coupled active electrode)의 열잡음(Thermal Noise) 모델을 구성하였다. 실험을 통해, 용량성 결합 능동 전극만의 배경 잡음의 크기가 열잡음 모델에서 예상한 수준과 거의 일치함을 확인하였다. 면으로 된 직물의 실제의 전기적 특성을 열잡음 모델에 적용하여, 면 위에서 측정된 간접접촉 심전도의 이론적 열잡음을 계산하였다. 이 연구를 통해, op-amp의 내부 잡음(intrinsic noise)은 저항에 의한 열잡음에 비해 무시할 수 있을 정도로 작음을 알 수 있었다. 그리고 열잡음의 크기와 능동 전극의 입력 저항간의 관계를 도출할 수 있게 되어, 능동 전극의 입력 저항의 최적 값 선정을 위한 향후 연구의 기반이 되었다.

국제결혼 부부의 초국적 이주배경에 대한 공간인지와 적응에 관한 연구 (A Study on the Spatial Cognition and the adjustment of Intermarriage Couples Regarding Transnational Migration Backgrounds)

  • 이경자
    • 한국지역지리학회지
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    • 제19권4호
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    • pp.712-736
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    • 2013
  • 1990년대 이후 초국적 이주에 의한 국제결혼 부부가 증가하고 있다. 따라서 그동안 이에 대한 많은 연구가 있었으나 접근방법 등의 한계로 결혼이주여성의 이주배경 및 국제결혼 부부의 적응에 대한 충분한 분석이 이루어지지 않고 있다. 이러한 문제의식에 따라 본 연구는 대구, 경북지역 국제결혼 부부 대상의 설문조사 및 심층면접 자료를 바탕으로 이들의 이주배경과 적응에 대하여 분석하였다. 국제이주배경에 관한 설문조사 분석결과 국제결혼 부부의 세계적 사항에 대한 인지도는 매우 높게 나타났으나, 이러한 거시적 배경은 부부 적응에 그다지 영향을 미치지 않는 것으로 분석되었다. 그러나 그들 부부의 삶과 적응에 직접적으로 영향을 미칠 것으로 예상되는 상대방에 대한 사전 인지정도는 부부 모두 매우 낮은 것으로 분석되었다.

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한국 연안 퇴적물 내 중금속 원소의 자연적 배경농도 연구 (Natural Background Level Analysis of Heavy Metal Concentration in Korean Coastal Sediments)

  • 임동일;최진용;정회수;최현우;김영옥
    • Ocean and Polar Research
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    • 제29권4호
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    • pp.379-389
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    • 2007
  • This paper presents an attempt to determine natural background levels of heavy metals which could be used for assessing heavy metal contamination. For this study, a large archive dataset of heavy metal concentration (Cu, Cr, Ni, Pb, Zn) for more than 900 surface sediment samples from various Korean coastal environments was newly compiled. These data were normalized for aluminum (grain-size normalizer) concentration to isolate natural factors from anthropogenic ones. The normalization was based on the hypothesis that heavy metal concentrations vary consistently with the concentration of aluminum, unless these metals are of anthropogenic origin. So, the samples (outliers) suspected of receivingany anthropogenic input were removed from regression to ascertain the "background" relationship between the metals and aluminum. Identification of these outliers was tested using a model of predicted limits at 95%. The process of testing for normality (Kolmogorov-Smirnov Test) and selection of outliers was iterated until a normal distribution was achieved. On the basis of the linear regression analysis of the large archive (please check) dataset, background levels, which are applicable to heavy metal assessment of Korean coastal sediments, were successfully developed for Cu, Cr, Ni, Zn. As an example, we tested the applicability of this baseline level for metal pollution assessment of Masan Bay sediments.

게임 배경그래픽과 배경맵 설계를 위한 게임 환경디자인 모델 연구 (Model of Game Environment Design for Adanced Game Background Graphic and Map Design)

  • 주정규
    • 한국게임학회 논문지
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    • 제4권3호
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    • pp.77-84
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    • 2004
  • 게임의 게임성, 재미의 제공, 볼거리 및 배경그래픽 제공하고, 게임플레이의 활동 무대인 배경-맵과 배경그래픽 디자인을 구현하기 위해서는 게임 배경환경은 매우 중요한 요소이다. 본 연구에서는 게임 배경환경의 구성요소를 정의하고, 시대적 및 역사적인 환경요소, 자연적인 환경요소, 인공적인 환경요소, 문화적인 환경요소, 가상적인 환경요소를 문헌과 사료를 통하여 고찰 연구하였으며, 실제 게임 배경맵에 적용할 수 있는 배경그래픽의 환경디자인 모델을 제시한다.

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Laver Farm Feature Extraction From Landsat ETM+ Using Independent Component Analysis

  • Han J. G.;Yeon Y. K.;Chi K. H.;Hwang J. H.
    • 대한원격탐사학회:학술대회논문집
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    • 대한원격탐사학회 2004년도 Proceedings of ISRS 2004
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    • pp.359-362
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    • 2004
  • In multi-dimensional image, ICA-based feature extraction algorithm, which is proposed in this paper, is for the purpose of detecting target feature about pixel assumed as a linear mixed spectrum sphere, which is consisted of each different type of material object (target feature and background feature) in spectrum sphere of reflectance of each pixel. Landsat ETM+ satellite image is consisted of multi-dimensional data structure and, there is target feature, which is purposed to extract and various background image is mixed. In this paper, in order to eliminate background features (tidal flat, seawater and etc) around target feature (laver farm) effectively, pixel spectrum sphere of target feature is projected onto the orthogonal spectrum sphere of background feature. The rest amount of spectrum sphere of target feature in the pixel can be presumed to remove spectrum sphere of background feature. In order to make sure the excellence of feature extraction method based on ICA, which is proposed in this paper, laver farm feature extraction from Landsat ETM+ satellite image is applied. Also, In the side of feature extraction accuracy and the noise level, which is still remaining not to remove after feature extraction, we have conducted a comparing test with traditionally most popular method, maximum-likelihood. As a consequence, the proposed method from this paper can effectively eliminate background features around mixed spectrum sphere to extract target feature. So, we found that it had excellent detection efficiency.

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