• 제목/요약/키워드: threshold value

검색결과 1,701건 처리시간 0.031초

다중 가변 문턱값을 이용한 복셀 칼라링 기법에 관한 연구 (A Study on the Voxel Coloring using Multi-variable Thresholding)

  • 김효성;이상욱;남기곤
    • 한국정보통신학회논문지
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    • 제9권5호
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    • pp.1102-1110
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    • 2005
  • 본 논문에서는 기존 복셀 칼라링 기법에서의 색상 일관성에 대한 문턱값 문제를 해결하기 위한 개선된 복셀 칼라링 기법을 제안하였다. 제안 기법에서는 표면 복셀에 대한 색상 일관성의 문턱값을 내부 복셀의 색상 일관성 값으로 대체함으로써 복셀 칼라링의 반복 회수가 증가함에 따라 개별 표면 복셀에 대한 최적의 문턱값을 찾아가도록 하였다. 또한 그래프 절단 기법을 적용하여 주위 복셀을 제거 판단에 함께 고려함으로써 표면 잡음을 감소시켰다.

전기화학적 및 해수 건습반복 방법에 의한 콘크리트 내의 임계 염화물량 평가 (Estimation of Chloride Corrosion Threshold Value in Concrete by Using Electrochemical and Cyclic Wet and Dry Seawater Method)

  • 배수호;이광명;정영수;김지상
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 2005년도 봄학술 발표회 논문집(II)
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    • pp.245-248
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    • 2005
  • It should be noted that the critical chloride threshold level is not considered to be a unique value for all conditions. This value is dependent on concrete mixture proportions, cement type and constituents, presence of admixtures, environmental factors, steel reinforcement surface. conditions, and other factors. In this study, the accelerated corrosion test for reinforcing steel was conducted by electrochemical and cyclic wet and dry seawater method, respectively and during the test, corrosion monitoring by half cell potential method was carried out to estimate the chloride corrosion threshold value when corrosion for reinforcing steel in concrete was perceived. For this purpose, lollypop and right hexahedron test specimens were made for 31.4$\%$, 41.5$\%$ and 49.7$\%$ of w/c, respectively and then the accelerated corrosion test for reinforcing steel was executed. It was observed from the test that the time to initiation of corrosion was found to be different with water-cement ratio and accelerated corrosion test method, respectively and the chloride corrosion threshold value was found to range from 0.91 to 1.43 kg/$m^{3}$.

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적응적 임계치와 가중치 결정 방법에 기반한 디지털 워터마킹 (Digital Watermarking Based on Adaptive Threshold and Weighting Factor Decision Method)

  • 임호;김진영
    • 대한전자공학회:학술대회논문집
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    • 대한전자공학회 2000년도 하계종합학술대회 논문집(4)
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    • pp.123-126
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    • 2000
  • In this paper, we propose new watermarking technique using weighting factor decision method in the watermark embedding step and adaptive threshold decision method in the watermark extracting step. In our method, we are determined weighting factor in simple by calculating distance between pixel coefficient and neighborhood pixel coefficients and threshold is adaptively determined by searching the minimized extract error value using histogram of difference value.

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Fast Scene Change Detection Algorithm

  • Khvan, Dmitriy;Ng, Teck Sheng;Jeong, Jechang
    • 한국방송∙미디어공학회:학술대회논문집
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    • 한국방송공학회 2012년도 추계학술대회
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    • pp.259-262
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    • 2012
  • In this paper, we propose a new fast algorithm for effective scene change detection. The proposed algorithm exploits Otsu threshold matching technique, which was proposed earlier. In this method, the current and the reference frames are divided into square blocks of particular size. After doing so, the pixel histogram of each block is generated. According to Otsu method, every histogram distribution is assumed to be bimodal, i.e. pixel distribution can be divided into two groups, based on within-group variance value. The pixel value that minimizes the within-group variance is said to be Otsu threshold. After Otsu threshold is found, the same procedure is performed at the reference frame. If the difference between Otsu threshold of a block in the current frame and co-located block in the reference frame is larger than predefined threshold, then a scene change between those two blocks is detected.

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효율적인 저전력 터보 복호기 (Efficient Low-Power Turbo Decoder)

  • 배성일;김재석
    • 대한전자공학회:학술대회논문집
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    • 대한전자공학회 1999년도 하계종합학술대회 논문집
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    • pp.73-76
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    • 1999
  • In this paper, we propose a new design of turbo decoder. It contains the simple additional unit which automatically decides the number of the iteration by detecting of the reliability value as threshold value. We investigate the relationship between the reliability value and the number of the iteration. We find the optimal threshold value without noticeable loss in performance. As a results of the simulation, it reduces the average number of the iteration compared with the conventional turbo decoder.

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기업의 규모별 특성이 사회적 책임과 기업가치 간의 비선형 관계를 유발하는 임계점에 미치는 영향에 대한 연구 (A Study on the Impact of Firm Size on the Threshold Point from Nonlinear Relationship between CSR and Firm Value)

  • 김종희
    • 아태비즈니스연구
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    • 제11권2호
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    • pp.207-233
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    • 2020
  • Purpose - The purpose of this paper analyzes the relationship between the Corporate Social Responsibility(CSR) and Corporate Value to estimate whether the characteristics of Firm can change this relationship. Design/methodology/approach - This paper utilizes the total 776 firms' data over the period 2014-2018, and develops a new ESG index which was estimated by PCA. Findings - First, the estimated ESG index implies that Large company has the highest value of CSR, while Medium sized and Small company have the relatively low one. And comparing to the case of 2014, the trend of ESG index in Large company does not decrease in 2018. Second, there is a clear and significant non linear relationship between CSR and corporate value, it implies that the U-shaped exists in the Korean Firms. Such a tendency is mush stronger in the Large company. Third, the new ESG index indicates that it takes more time to increase Firm value in the Medium sized and Small company while there is a high possibility of increasing value in Large company from the little gab between the threshold points and mean value of ESG. Research implications or Originality - The non linear tendency between the Corporate Social Responsibility and Corporate Value is strongly affected by Firm size and the relative high quintile of ESG, but it is less affected by Firm history.

An Optimal Thresholding Method for the Voxel Coloring in the 3D Shape Reconstruction

  • Ye, Soo-Young;Kim, Hyo-Sung;Yi, Young-Youl;Nam, Ki-Gon
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 2005년도 ICCAS
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    • pp.1695-1700
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    • 2005
  • In this paper, we propose an optimal thresholding method for the voxel coloring in the reconstruction of a 3D shape. Our purposed method is a new approach to resolve the trade-off error of the threshold value on determining the photo-consistency in the conventional method. Optimal thresholding value is decided to compare the surface voxel of photo-consistency with inside voxel on the optic ray of the center camera. As iterating the process of the voxels, the threshold value is approached to the optimal value for the individual surface voxel. And also, graph cut method is reduced to the surface noise on eliminating neighboring voxel. To verify the proposed algorithm, we simulated in the virtual and real environment. It is advantaged to speed up and accuracy of a 3D face reconstruction by applying the methods of optimal threshold and graph cut as compare with conventional algorithms.

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저궤도 위성 Receiver의 Threshold측정 시험 결과에 대한 분석 (Analysis about Threshold Measurement Test Result of LEO Satellite Receiver)

  • 조승원;권재욱;최종연;최석원
    • 항공우주기술
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    • 제5권2호
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    • pp.77-84
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    • 2006
  • 저궤도 위성의 시스템 시험에서는 위성의 5 대역 Receiver의 적정 수신 RF 전력 영역을 확인하기 위하여 저궤도 위성의 Receiver Tracking Threshold와 Command Threshold를 측정한다. 본 논문에서는 두 Threshold 측정의 알고리듬을 살펴보고 통합 시스템 시험 (Integrated System Test)에서 수행하였던 결과를 보여준다. 그 후에 Receiver의 성능 이외 에 Threshold 측정결과에 영향을 미칠 수 있는 요소를 알아보고 그에 따른 왜곡된 값을 분석하여 보정을 수행하였다.

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경과 시간에 따른 청색 형광 OLED의 Impedance 특성 (Impedance Characteristics of Blue Fluorescent OLED According to Elapsed Time)

  • 공도훈;양재웅;주성후
    • 한국표면공학회지
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    • 제50권5호
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    • pp.405-410
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    • 2017
  • In order to study current-voltage-luminance and impedance characteristics according to elapsed time, a blue fluorescent OLED was fabricated. The current density and luminance gradually decreased in accordance with elapsed time and did not emit light after 480 hours, and the threshold voltage increased as time elapsed. The Cole-Cole plot was a semicircular shape of a very large size at 2 V of the applied voltage below the threshold voltage, and the maximum value of the real number impedance did not change greatly from 9314.5 to $9902.2{\Omega}$ as time elapsed. Applied voltages 4, 6, and 8 V above the threshold voltage showed a large change in the real number impedance value at the semicircle end to 9,678.2, 9,826, $9,535.4{\Omega}$ according to the elapsed time from 2,222.5, 183.7, $48.2{\Omega}$ immediately after fabricating the device. By increasing the applied voltage beyond the threshold voltage just after device fabrication, the energy difference between the device and the organic layer was overcome and the current flowed, the maximum value of the real number impedance sharply decreased. As time passed, current did not flow through the element even at high applied voltage due to degradation of the element, and even when the applied voltage was higher than the threshold voltage, it showed an impedance value such as applied voltage equal to or less than the threshold voltage. As a result, it can be learned that the change in the impedance with elapsed time reflects the characteristics due to the degradation of the OLED and can predict the characteristics and lifetime of the OLED.

하천에 설치된 횡구조물의 영향 및 섬진강 수계의 어류 풍부도 예측 (Impact of the Crossed-Structures Installed in Streams and Prediction of Fish Abundance in the Seomjin River System, Korea)

  • 문운기;노다혜;유재상;임오영;김명철;김지혜;이정민;김재구
    • Ecology and Resilient Infrastructure
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    • 제9권2호
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    • pp.100-106
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    • 2022
  • 섬진강 수계 210개 지방하천을 대상으로 하천연장과 보 밀도 대비 어류 출현종 현황을 분석하였다. 하천연장에 따른 어류 출현종수는 비선형지수함수 (Nonlinear exponential relationship) 관계를 보였다. 모델에 따른 계수값 (b)은 0.03이며, 결정계수(R2)은 약 59.0%인 것으로 나타났다. 모델식에 따른 예측기대종수는 실제 출현종수와 차이를 보였으며, 대상하천 가운데 약 110개 하천 (약 52.4%)에서 실제 출현종수는 예측기대종수보다 낮게 나타났다. 한편 섬진강 수계 하천에서 나타난 평균 보 밀도는 약 2.7개/km였으며, 이는 타 수계 하천과 비교시 월등히 높은 수치였다. 보 밀도 지표 (Index of Weir's Density, IWD)에 따른 어류출현종수간의 2-DKS 분석 결과 어류 다양성에 영향을 주는 보 밀도 역치값 (Threshold value)은 약 2.5개/km인 것으로 나타났다 (Dmax=0.048, p<0.05). 실제 보 밀도 지표가 역치값 이상인 경우 어류 출현종수 대비 기대 종수비율은 70% 미만으로 낮아졌다. 따라서, 향후 수생태계 연속성 확보를 위한 보 밀도는 역치값 이하로 관리하는 것이 필요하다.