• Title/Summary/Keyword: Line-focus

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Measurements of Defects after Machining CFRP Holes Using High Speed Line Scan (고속 라인 스캔 방식을 이용한 CFRP 가공 홀 표면 및 내부 결함 검사)

  • Kim, Teaggyum;Kyung, Daesu;Son, Unchul;Park, Sun-Young
    • Journal of the Korean Society for Precision Engineering
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    • v.33 no.6
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    • pp.459-467
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    • 2016
  • Using a line scan camera and a Galvano mirror, we constructed a high-speed line-scanning microscope that can generate 2D images ($8000{\times}8000pixels$) without any moving parts. The line scanner consists of a Galvano mirror and a cylindrical lens, which creates a line focus that sweeps over the sample. The measured resolutions in the x (perpendicular to line focus) and y (parallel to line focus) directions are both $2{\mu}m$, with a 2X scan lens and a 3X relay lens. This optical system is useful for measuring defects, such as spalling, chipping, delamination, etc., on the surface of carbon fiber reinforced plastic (CFRP) holes after machining in conjunction with adjustments in the angle of LED lighting. Defects on the inner wall of holes are measured by line confocal laser scanning. This confocal method will be useful for analyzing defects after CFRP machining and for fast 3D image reconstruction.

An examination of Porter`s competitive strategy on the virtual market: comparison between on-line and on-offline firms (가상시장에서 Porter의 경쟁우위전략: 온라인 기업과 온-오프라인기업간 비교를 중심으로)

  • Nam, Ki-Chan;Koo, Chul-Mo;Gee, Seung-Goo
    • Asia pacific journal of information systems
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    • v.12 no.4
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    • pp.173-192
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    • 2002
  • Internet-based on-line firms have focused on the development of new business models with an assumption that this new model would create their competitiveness. At the same time, off-line firms have opened new marketing channels on the internet in order to defend their position against on-line firms. Based on Porter's well-known generic strategy, this study compares between on-line firms and on-offline firms i) whether these two types of firms take different strategies among cost reduction, marketing differentiation, innovation differentiation, and focus and ii) how the performance of these two types of firms is affected by different strategy types. The result shows that on-offline firms prefer the strategy of marketing differentiation and innovative differentiation while the strategy of cost reduction and focus are taken without significant difference between online firms and on-offline firms. Also it is found that even though the strategy of marketing differentiation and innovation differentiation are more preferred by on-offline firms than on-line firms, these two strategy types have a significant influence on the on-line firms' performance while the focus strategy has a significant influence on the on-offline firms' performance. Other managerial implications are discussed.

Stress Evaluation by the Measurement of Acoustoelastic Effect Using a Line-Foucus Acoustic Microscope (선 집속 초음파 현미경을 이용한 음탄성효과 측정에 의한 응력 평가)

  • Kim, J.O.;Lee, Y.C.
    • Journal of the Korean Society for Precision Engineering
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    • v.14 no.10
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    • pp.119-126
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    • 1997
  • The relationship between the applied stresses and the change of elastic wave velocity has been established based on the acoustoelasticity theory. The non-uniform stress field in a loaded specimen has been evaluated from the surface acoustic wave velocity measured by the line-focus acoustic microscopy with the acoustoelastic constants obtained form a calibration test. The evaluated stresses are in good agreement with the results calculated by finite element method.

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A Study on the Declination According to Length of Utterance, Clause Boundary and Focus in Korean (한국어의 발화 길이 및 절 경계와 초점에 의한 점진하강(declination) 연구)

  • Kwak, Sook-Young
    • Phonetics and Speech Sciences
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    • v.2 no.3
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    • pp.11-22
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    • 2010
  • The present study attempts to investigate declination in Korean and its relevant aspects to the length of utterance, the clause boundary, and focus. More specifically, I examine the relation of declination with the length of utterance, the declination reset at the clause boundary, and the effect of focus on declination. Results showed that the length of utterance had no relation with the first and last pitch values of the utterance but that they were consistent regardless of the length of utterance. However, the declination slope changed to be relatively gentle from the fourth accentual phrase to the end of the whole intonational phrase. There was a reset of declination in such a way that the first pitch in the second phrase was always lower than that of the first phrase, but the first pitch in the third phrase was not always lower than that of the second phrase when the whole utterance was composed of three phrases. Finally, the pitch values of the focusing words decreased as their position went back in a sentence. One declination line was formed in the case of focused utterance, but in the case of an utterance that contained a clause boundary, a new declination line was formed at the start of each new clause. These findings can be applied to developing a Korean speech synthesizer that contains natural prosody; they can be also utilized for teaching Korean prosody.

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Focal Length Control of Line-focus Ultrasonic Transducer Using Bimorph-type Bending Actuator (바이몰프형 밴딩 액츄에이터를 이용한 선집속형 초음파 트랜스듀서의 초점 거리 제어)

  • 채민구;하강열;김무준
    • The Journal of the Acoustical Society of Korea
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    • v.22 no.3
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    • pp.202-207
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    • 2003
  • For medical ultrasonic transducer, phase-weighting method has been used for controlling focal length with electric circuit at each vibrating element. However, the electric circuit is complex as the number of vibrating elements is increased. In this paper, we fabricated line-focus transducer with a bimorph-type piezoelectric actuator. The polyvinylidene fluoride (PVDF) piezoelectric type polymer film is used for transmitting and receiving of ultrasonic signal. Using this transducer, focal length of the transducer can be controlled mechanically by changing voltage of the actuator. It is confirmed that focal length of the transducer can be controlled in range of 1095 to radius of curvature.

User-Guidable Abstract Line Drawing of 2D Images (사용자 제어가 용이한 이차원 영상의 추상화된 라인 드로잉 생성)

  • Son, Min-Jung;Lee, Yun-Jin;Kang, Hen-Ry;Lee, Seung-Yong
    • Journal of KIISE:Computer Systems and Theory
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    • v.37 no.2
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    • pp.110-125
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    • 2010
  • We present a novel scheme for generating line drawings from 2D images, aiming to facilitate effective visual communication. In contrast to conventional edge detectors, our technique imitates the human line drawing process to generate lines effectively and intuitively. Our technique consists of three parts: line extraction, line rendering, and user guidance. In line extraction, we extract lines by estimating a likelihood function to effectively find the genuine shape boundaries. In line rendering, we consider the feature scale and the blurriness of lines with which the detail and the focus-level of lines are controlled. We also employ stroke textures to provide a variety of illustration styles. User guidance is allowed to modify the shapes and positions of lines interactively, where immediate response is provided by GPU implementation of most line extraction operations. Experimental results demonstrate that our technique generates various kinds of line drawings from 2D images enabled by the control over detail, focus, and style.

A Study on Depth of Focus of Particle in Digital Particle Holography (디지털 입자 홀로그래피의 입자 초점 심도에 관한 연구)

  • Yang, Yan;Kang, Bo-Seon
    • Journal of ILASS-Korea
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    • v.14 no.2
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    • pp.77-83
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    • 2009
  • In this study, the effect of important parameters such as the pixel size and number of a CCD, the object distance, the wavelength of laser, and the particle diameter on the depth of focus in digital in-line particle holography were investigated. The depth of focus in several different cases was calculated using simulation holograms and detailed description of the depth of focus in digital particle holography was presented. The depth of focus is directly proportional to the object distance and the particle size. With the increase of the wavelength of laser, the depth of focus is decreased. The depth of focus is also inversely proportional to the pixel size and number of a CCD. Using the data of depth of focus from simulation holograms and a data-fitting software, we obtained the prediction equations of depth of focus for typical CCD cameras. Finally, the prediction equations of depth of focus in digital particle holography were verified by investigating real holograms of the calibration target in different cases and satisfied agreement between measured values and predicted values was confirmed.

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LSAW Velocity Measurement by Using a PVDF Line-Focus Ultrasonic Transducer (PVDF 직선집속 초음파 트랜스듀서에 의한 누설탄성표면파 속도 측정)

  • 윤혁준;하강열;김무준;윤종락
    • The Journal of the Acoustical Society of Korea
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    • v.20 no.1
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    • pp.62-67
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    • 2001
  • Velocities of leaky surface acoustic waves (LSAW/sub s/) were measured by using a line-focus polyvinylidene fluoride (PVDF) transducer and compared with theoretically calculated ones. Isotropic materials of Cu, Al, fused quartz, and anisotropic one of Z-cut α-quartz crystal were used as specimens. The velocities were obtained by the separation time between wave components reflected directly from the surface of specimen and LSAW components according to the defocusing distance. The measured velocities well agree with the theoretical results within 1% error, and it was shown that the leaky pseudo-surface acoustic wave (LPSAW) as well as the LSAW propagates with the typical 6-fold anisotropy on the (0,0,1) surface of α-quartz.

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The Binarization of Text Regions in Natural Scene Images, based on Stroke Width Estimation (자연 영상에서 획 너비 추정 기반 텍스트 영역 이진화)

  • Zhang, Chengdong;Kim, Jung Hwan;Lee, Guee Sang
    • Smart Media Journal
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    • v.1 no.4
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    • pp.27-34
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    • 2012
  • In this paper, a novel text binarization is presented that can deal with some complex conditions, such as shadows, non-uniform illumination due to highlight or object projection, and messy backgrounds. To locate the target text region, a focus line is assumed to pass through a text region. Next, connected component analysis and stroke width estimation based on location information of the focus line is used to locate the bounding box of the text region, and each box of connected components. A series of classifications are applied to identify whether each CC(Connected component) is text or non-text. Also, a modified K-means clustering method based on an HCL color space is applied to reduce the color dimension. A text binarization procedure based on location of text component and seed color pixel is then used to generate the final result.

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On-line Recommendation Service Algorithm using Human Sensibility Ergonomics (감성공학을 이용한 온라인 추천 서비스 알고리즘)

  • 임치환
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.27 no.1
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    • pp.38-46
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    • 2004
  • To be successful in increasingly competitive Internet marketplace, it is essential to capture customer loyalty. This paper deals with an intelligent agent approach to incorporate customer's sensibility into an one-to-one recommendation service in on-line shopping mall. In this paper the focus of interest is on-line recommendation service algorithm for development of Human Sensibility based web agent system. The recommendation agent system composed of seven services including specialized algorithm. The on-line recommendation service algorithm use human sensibility ergonomics and on-line preference matching technologies to tailor to the customer the suggestion of goods and the description of store catalog. Customizing the system's behavior requires the parallel execution of several tasks during the interaction (e.g., identifying the customer's emotional preference and dynamically generating the pages of the store catalog). Most of the present shopping malls go through the catalog of goods, but the future shopping malls will have the form of intelligent shopping malls by applying the on-line recommendation service algorithm.