• Title/Summary/Keyword: focus control

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Image Noise Removal using State Estimation Filter (상태 추정 필터를 이용한 영상 잡음 제거)

  • Jang, Hoon-Seok
    • The Journal of Korea Institute of Information, Electronics, and Communication Technology
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    • v.15 no.4
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    • pp.237-242
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    • 2022
  • Acquiring high-quality images in control and measurement systems is one of the important factors. Among image acquisition technologies, SFF (Shape from Focus) is a technology for recovering a 3D shape by acquiring 2D images with different focus levels by moving an object at a predetermined step size along the optical axis. For SFF, when an object is moved at a constant step size, mechanical vibration, referred as jitter noise, occurs in each step along the optical axis. In this paper, a new state estimation filter is designed and applied for reducing the jitter noise. For the application of the proposed method, the jitter noise and focus curves are modeled as Gaussian function. Experimental results demonstrate the effectiveness of proposed method.

Analysis of Two-tier Supply Chains with Multiplicative Random Yields

  • Park, Kyungchul
    • Management Science and Financial Engineering
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    • v.22 no.1
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    • pp.1-4
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    • 2016
  • We consider a two-tier supply chain with multiplicative random yield. We focus on the supply chain performance with respect to the control scheme of determining the production lot size. The profit loss due to distributed control is analyzed to give an insight for devising efficient supply contracts.

Automatic Control of Horizontal-moving Stereoscopic Camera by Disparity Compensation (시차 보정에 의한 수평이동방식 입체카메라의 자동제어)

  • Kwon, Ki-Chul;Lee, Yong-Bum;Choi, Young-Soo;Huh, Kyung-Moo;Kim, Nam
    • Journal of the Institute of Electronics Engineers of Korea CI
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    • v.38 no.5
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    • pp.77-85
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    • 2001
  • The purpose of this study is to suggest Vergence Information Extracting Algorithm(VIEA) which enables quick and accurate vergence information achievement for automation of vergence and focus control of horizontal moving stereoscopic camera. Firstly, for this purpose, the geometric structure of horizontal moving stereoscopic camera device was analyzed and linear relation between the vergence and the focus control. Then stereoscopic camera was designed and produced with the application of vergence and focus relation formula. Finally, VIEA that uses Cepstrum filter was employed to implement Automatic Vergence and Focus Controlling Stereoscopic Camera System(AVFCSCS). VIEA showed lower vergence achievement time and error ratio in comparison with existing algorithms. The suggested system in this study substantially reduced the controlling time and error-ratio as to make it possible to achieve natural and clear images. It also simplified the handling of stereoscopic camera for the convenience of end-users.

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Shape Adaptive Searching Region to Find Focused Image Points in 3D Shape Reconstruction (3차원 형체복원에 있어서 측정면에 적응적인 초점화소 탐색영역 결정기법)

  • 김현태;한문용;홍민철;차형태;한헌수
    • 제어로봇시스템학회:학술대회논문집
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    • 2000.10a
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    • pp.77-77
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    • 2000
  • The shape of small or curved object is usually reconstructed using a single camera by moving its lens position to find a sequence of the focused images. Most conventional methods have used a window with fixed shape to test the focus measure, which resulted in a deterioration of accuracy. To solve this problem, this paper proposes a new approach of using a shape adaptive window. It estimates the shape of the object at every step and applies the same shape of window to calculate the focus measure. Focus measure is based on the variance of the pixels inside the window. This paper includes the experimental results.

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Position and Force Control Based on Fuzzy Switching Algorithm

  • Jaehyun Jin;Sungho Ahn;Park, Byungsuk;Jisup Yoon
    • 제어로봇시스템학회:학술대회논문집
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    • 2002.10a
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    • pp.85.1-85
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    • 2002
  • In this paper, a control strategy of position and force is proposed based on a switching algorithm. The main focus is the control of position and force in the same direction. The switching algorithm based on a fuzzy algorithm determines the weighting value of force control. First, the force control is dominant. If the position gets closer to the desire position, the weighting value of force control is closer to zero. The proposed algorithm is shown to be satisfactory to position and force control and the weighting factor is quite successful by simulation examples.

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Damage propagation for aircraft structural analysis of composite materials

  • Hung, C.C.;Nguyen, T.
    • Advances in aircraft and spacecraft science
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    • v.9 no.2
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    • pp.149-167
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    • 2022
  • A Modified fuzzy mechanical control of large-scale multiple time delayed dynamic systems in states is considered in this paper. To do this, at the first level, a two-step strategy is proposed to divide a large system into several interconnected subsystems. And we focus on the damage propagation for aircraft structural analysis of composite materials. As a modified fuzzy control command, the next was received as feedback theory based on the energetic function and the LMI optimal stability criteria which allow researchers to solve this problem and have the whole system in asymptotically stability. And we focus on the results which shows the high effective by the proposed theory utilized for damage propagation for aircraft structural analysis of composite materials.

Control Parameter Extraction using Wavelet Transform for Auto-Focus Control of Stereo Camera (입체 카메라의 자동 초점 제어를 위한 웨이블릿 변환을 이용한 제어 변수 추출)

  • 엄기문;허남호;김형남;조진호;이진환
    • Journal of Broadcast Engineering
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    • v.5 no.2
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    • pp.239-246
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    • 2000
  • An efficient control parameter extraction scheme required for auto-focusing control of a stereo camera is proposed. Without loss of generality, it is assumed that an interesting object exists in the center of a captured image by a stereo camera. In such a case. we apply a 2-dimensional wavelet transform to the center area with specific image size in the captured image. Next, we extract required focus control parameters using an Ll-norm for doubly high-pass filtered components. Experimental results show that the proposed scheme is effectively applicable to the auto-focusing for a stereo camera compared to the conventional control scheme using discrete cosine transform (DCT).

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The Recognition Method for Focus Level using ECG(electrocardiogram) (심전도를 이용한 집중도 인식 방법)

  • Lee, Dong Won;Park, Sangin;Whang, Mincheol
    • The Journal of the Korea Contents Association
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    • v.18 no.2
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    • pp.370-377
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    • 2018
  • Focus level has been important mental state in user study. Cardiac response has been related to focus and less clarified. The study was to determine cardiac parameters for recognizing focus level. The sixty participants were asked to play shooting game designed to control two focus levels. Electrocardiogram was measured during task. The parameters of time domain and frequency domain were determined from ECG. As a result of independent t-test, RRI, SDNN, rMSSD and pNN50 of time domain indicator were statistically significant in recognizing focus level. LF, HF, lnLF and lnHF of frequency domain were observed to be significant indicator. The rule base for recognition has been developed by the combination of RRI, rMSSD and lnHF. The rule base has been verified from another sixty data samples. The recognition accuracy were 95%. This study proposed significant cardiac indicators for recognizing focus level. The results provides objective measurement of focus in user interaction design in the fields of contents industry and service design.

Using Focus Group Interviews to Assess Food Behavior and Needs of Nutrition Education for Female University Students

  • Kim, Kyungwon;Kim, Kyung-A
    • Journal of Community Nutrition
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    • v.1 no.1
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    • pp.25-32
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    • 1999
  • In this study, focus group interviews were used to investigate female university students' eating behavior, factors related to eating behavior, information sources for nutrition, and formats for nutrition education. Thirty-six students participated in one of five focus groups during December 1998 in Seoul. Focus group discussions were video, audio-taped, transcribed and analyzed by major themes. Results showed that subjects have undesirable eating behaviors, such s eating irregular meals and skipping meals. These behaviors are caused by a lack of time, habit, or for the purpose of losing weight. The students tended to have unbalanced diets and frequently ate out. They had a large amount for dinner and frequently snaked when stressed or had an empty stomach. Most of them were interested in weight control and had attempted to lose weight, but they did not participate in regular exercise. The most frequently used source for nutrition information was the mass media, but much nutrition information was based on what they learned from home economics class during middle to high school. They received more support from mothers, elder sisters, and friends for eating behaviors, such s lowering caloric intake and losing weight. In nutrition education, they wanted to learns behaviorla skills to adopt healthy behaviors, including meal planning, applying scientific weight control methods, exercise that fit into their lives, and stress management. They also mentioned that nutrition screening and assessment should be a part of nutrition education programs. As a method for nutrition education, subjects preferred an individualized approach to group education. These results provide the qualitative information for developing nutrition education programs which will be implemented for Korean University students.

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2M Class CCM(Compact Camera Module) Defect Inspection (2M급 CCM(Compact Camera Module) 불량 검사)

  • Cho S.Y.;Ko K.W.;Lee Y.J.;Lee J.H.;Kang C.G.
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2005.06a
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    • pp.1079-1082
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    • 2005
  • This paper deals with the algorithm development that inspects defects such as Lens Focus, Focus check, Black Defect, Dark Defect, Dim Defect, Color Defect, and Line Defect, Angle Defect, IrisAgc Defect caused by the process of 2M Class Compact Camera Module (CCM). Domestic market was majorly comprised of VGA(0.3 million pixel) market. But in the middle of year 2004, camera phone with Mega Pixel has appeared, and it is estimated that the camera phone with Mega Pixel will take up to 28% of total phone sales if it is released in the end of year 2004. Since the inspection of finished products is done manually, it is major obstacle in production increment In this paper, to solve these problems, we developed the imaging processing algorithm to inspect the defects in captured image of assembled CCM. The performances of the developed inspection system and we can recognize various types of defect of CCM modules with good accuracy and high speed

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