• Title/Summary/Keyword: CCD Method

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Study on the Improvement of Indirect Intra-Oral Dental Digital X-ray Image Sensor with Optical Coupling

  • Whang, Joo-Ho;Chung, Jin-Bum;Kim, Tae-Woo
    • Nuclear Engineering and Technology
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    • v.33 no.5
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    • pp.514-525
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    • 2001
  • Optimum characteristics of digital X-ray sensor components were analyzed to develop intra- oral dental digital X-ray image sensor using indirect method. Parametric analysis was carried out to optimize the phosphor thickness and the fiber optic plate (FOP) coupling to charge coupled device (CCD). X-ray absorption and light diffusion in the phosphor layer were analyzed by the Monte Carlo method. Real time X-ray image was obtained with prototype X- ray image sensor using general CCD camera with 1∼10 Ip/mm resolution. It has been previously shown that large resolution degradation in X-ray images was caused by miss alignment of FOP to CCD and optical adhesive selection. In this study, we reported that X-ray image quality was greatly improved by using optimized characteristics of alignment device and phosphor thickness.

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Approximate Optimization Design Considering Automotive Wheel Stress (자동차용 휠의 응력을 고려한 근사 최적 설계)

  • Lee, Hyunseok;Lee, Jongsoo
    • Journal of the Korean Society of Manufacturing Technology Engineers
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    • v.24 no.3
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    • pp.302-307
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    • 2015
  • The automobile is an important means of transportation. For this reason, the automotive wheel is also an important component in the automotive industry because it acts as a load support and is closely related to safety. Thus, the wheel design is a very important safety aspect. In this paper, an optimal design for minimizing automotive wheel stress and increasing wheel safety is described. To study the optimal design, a central composite design (CCD) and D-optimal design theory are applied, and the approximate function using the response surface method (RSM) is generated. The optimal solutions using the non-dominant sorting genetic algorithm (NSGA-II) are then derived. Comparing CCD and D-optimal solution accuracy and verified the CCD can deduce more accuracy optimal solutions.

A Clustering Method for Optimizing Spatial Locality (공간국부성을 최적화하는 클러스터링 방법)

  • 김홍기
    • Journal of KIISE:Databases
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    • v.31 no.2
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    • pp.83-90
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    • 2004
  • In this paper, we study the CCD(Clustering with Circular Distance) and the COD(Clustering with Obstructed Distance) problems to be considered when objects are being clustered in a circularly search space and a search space with the presence of obstacles. We also propose a now clustering algorithm for clustering efficiently objects that the insertion or the deletion is occurring frequently in multi-dimensional search space. The distance function for solving the CCD and COD Problems is defined in the Proposed clustering algorithm. This algorithm is included a clustering method to create clusters that have a high spatial locality by minimum computation time.

Position Determination Using Multi-lateration Method (멀티레터레이션법을 이용한 절대간섭계의 점광원 위치 결정법)

  • Kim, Byoung-Chang
    • Journal of Institute of Control, Robotics and Systems
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    • v.12 no.9
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    • pp.856-860
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    • 2006
  • A CCD camera is used to determine the position of the point sources that influence the measurement accuracy in the absolute interferometer. The principle of determination method is based on the GPS in which the position is determined by more than 3 distance information from the known positions. Two-dimensional array of photo-detectors in the CCD camera is used as known positions. Performing optimization of the cost function constructed with phase values measured at each pixel on the CCD camera, the position coordinates of each source is precisely determined.

An Experimental Study on Shear Strength of Set Anchors Installed in Plain Concrete (무근콘크리트에 매입된 셋트앵커의 전단내력평가에 관한 실험적 연구)

  • Seo, Seong Yeon;Yang, Young Sung;Kim, Kyu Suk
    • Journal of Korean Society of Steel Construction
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    • v.17 no.3 s.76
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    • pp.271-283
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    • 2005
  • This paper concerns the prediction of shear capacity, as governed by steel failure and concrete breakout failure, of set anchors installed in plain concrete. For this purpose, the methods to evaluate the shear capacity of the set anchors in concrete are summarized and the experimental data are compared with capacities by the two present methods : the method of ACI349-90 and the Concrete Capacity Design (CCD) method. (1) The constant-0.684 in the steel strength equation of set anchor was determined from shear test data at the 5 percent fractile probability. Consequently, it was concluded that the constant-0.6 and 0.5 in the steel strength equation for steel failure of ACI318-02 and EOTA were safe. The nominal shear strength of set anchor was proposed as following. $V_s=0.684 A_{se}f_{ut}$. (2) The CCD method was considered reasonable in estimating the concrete breakout strength of set anchors. In terms of the CCD method, the nominal concrete breakout strength of set anchor in shear was provided as follows; $V_b=0.609(\frac{\iota}{d_o})^{0.2}\sqrt{d_0}\sqrt{f_c}(c_1)^{1.5}$(N). (3) The CCD method was considered reasonable in estimating the concrete breakout strength for spacing of set anchors. The proposed equation was considered safe in estimating the concrete breakout strength for spacing of set anchors.

Measurement of Micro-displacement of an Object by Laser Speckle using Linear Array CCD Detection System (레이저 스펙클과 1차원 CCD소자를 이용한 물체의 미소변위측정에 관한 연구)

  • 우창헌;민동현;김수용
    • Korean Journal of Optics and Photonics
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    • v.5 no.1
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    • pp.138-143
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    • 1994
  • A speckle correlation method was applied to measure the in-plane translation of a diffuse object which has rough surface using a linear CCD sensor and personal computer. Displacement of a speckle pattern produced from the object illuminated by a laser beam was measured by the cross-correlation functions between the I-D speckle profiles before and after the object translation, which were measured by linear CCD array sensor to be sent to IBM 386 personal computer. The sensitivity of the measurement was dependent on the radius of the wavefront curvature of incident beam as well as the spatial resolution of linear CCD array. A linear CCD array had 15 Jlffi pitch and 1728 pixels. The ratio of the speckle displacement and object translation varied from 1.03 to 5.20. The object translation of $3\mu\textrm{m}$ can be measured br the linear CCD sensor of which pitch was $15\mu\textrm{m}$, when the ratio of the speckle displacement and object translation was 5.20.s 5.20.

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Emotion Recognition by Vision System (비젼에 의한 감성인식)

  • 이상윤;오재흥;주영훈;심귀보
    • Proceedings of the Korean Institute of Intelligent Systems Conference
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    • 2001.12a
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    • pp.203-207
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    • 2001
  • In this Paper, we propose the neural network based emotion recognition method for intelligently recognizing the human's emotion using CCD color image. To do this, we first acquire the color image from the CCD camera, and then propose the method for recognizing the expression to be represented the structural correlation of man's feature Points(eyebrows, eye, nose, mouse) It is central technology that the Process of extract, separate and recognize correct data in the image. for representation is expressed by structural corelation of human's feature Points In the Proposed method, human's emotion is divided into four emotion (surprise, anger, happiness, sadness). Had separated complexion area using color-difference of color space by method that have separated background and human's face toughly to change such as external illumination in this paper. For this, we propose an algorithm to extract four feature Points from the face image acquired by the color CCD camera and find normalization face picture and some feature vectors from those. And then we apply back-prapagation algorithm to the secondary feature vector. Finally, we show the Practical application possibility of the proposed method.

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Assessment of Fracture Behaviors for CIP Anchors Fastened to Cracked and Uncracked Concretes

  • Yoon, Young-Soo;Kim, Ho-Seop;Kim, Sang-Yun
    • KCI Concrete Journal
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    • v.13 no.2
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    • pp.33-41
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    • 2001
  • This paper presents the crack effect on CIP anchors and prediction of tensile capacity, as governed by concrete cone failure. Single anchors where located at center of concrete specimen. Three different types of cracks such as crack width of 0.2 mm and 0.5 mm, crack depth of 10 cm and 20cm , and crack location of center and off-center point were simulated. Static tensile load was applied to 7/8-in. CIP anchors of 10 cm and 20 cm embedment length in concrete with compressive strength of 280 kgf/$\textrm{cm}^2$. Tested pullout capacities were compared to the values determined using current design methods (such as ACI 349-97, ACI 349 revision and CEB-FIP which is based on CCD Method). The comparison of CCD Method and ACI revision showed almost the same values in uncracked concrete specimen. In cracked concrete, CCD Method predicted conservative values. Three-dimensional non-linear FEM modeling also has been performed to determine the stresses distribution and crack inclination.

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Vibration Measurements of Large-Scale Structure Using Laser and High-Speed CCD Camera (레이저와 고속 CCD 카메라를 이용한 대형구조물의 진동계측)

  • 이창복;안세호;양성훈;염정원;강동욱;김기두
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.29 no.8C
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    • pp.1104-1112
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    • 2004
  • In this paper, we establish measurement methods of vibration frequency for three-dimensional behavior measurement of large-scale structure using laser and high-speed CCD camera. We project the diode laser having a smaller fluctuation on the object plane attached to the structure and measure the displacement of the structure using a precise relative measurement algorithm. When we use high-speed(120 frames/sec) CCD camera, we can measure the vibration frequency having the uncertainty within 0.5% by taking FFT on the displacement, from 0Hz to 40Hz. And we also confirm the reliability and economical string of the suggested measurement method of vibration frequency of the structure by showing the accuracy of displacement measurement using laser is comparable to that of relative positioning methods using GPS.

Measurement of 3D Spreader Position Information using the CCD Cameras and a Laser Distance Measuring Unit

  • Lee, Jung-Jae;Nam, Gi-Gun;Lee, Bong-Ki;Lee, Jang-Myung
    • Journal of Navigation and Port Research
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    • v.28 no.4
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    • pp.323-331
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    • 2004
  • This paper introduces a novel approach that can provide the three dimensional information about the movement of a spreader by using two CCD cameras and a laser distance measuring unit in order to derive ALS (Automatic Landing System) in the crane used at a harbor. So far a kind of 2D Laser scanner sensor or laser distance measuring units are used as comer detectors for the geometrical matching between the spreader and a container. Such systems provide only two dimensional information which is not enough for an accurate and fast ALS. In addition to this deficiency in performance, the price of the system is too high to adapt to the ALS. Therefore, to overcome these defects, we proposed a novel method to acquire the three dimensional spreader information using two CCD cameras and a laser distance measuring unit. To show the efficiency of proposed method, real experiments are performed to show the improvement of accuracy in distance measurement by fusing the sensory information of the CCD cameras and a laser distance measuring unit.