• 제목/요약/키워드: Distorted circle

검색결과 12건 처리시간 0.032초

렌즈에 의해 왜곡된 원영상의 교정 (Circle calibration distorted by camera lense)

  • 최춘호;문철홍
    • 대한전자공학회:학술대회논문집
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    • 대한전자공학회 1998년도 하계종합학술대회논문집
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    • pp.721-724
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    • 1998
  • A circular image in a space don't appear as an exact circular image and appear as an oval in image buffer because distortion of camera lens, number of horizontal pixel of CCD photographing element and unmber of horizontal pixel of image buffer are not in accordance. By using familiar 3-D coordinate, know as circle's diameter, and cicle's center, you correct a pin-hole camera and get an exact circle with reprojection a circle into image buffer, according to a perspective.

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지수창함수를 사용한 임팩트햄머 실험에서 주파수응답함수의 왜곡과 개선책 (FRF Distortion Caused by Exponential Window Function on Impact Hammer Testing and Its Solution)

  • 안세진;정의봉
    • 한국소음진동공학회논문집
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    • 제13권5호
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    • pp.334-340
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    • 2003
  • Exponential window function Is widely used In impact hammer testing to reduce leakage error as well as to get a good S/N ratio. The larger its decaying rate is, the more effectively the leakage errors are reduced. But if the decay rate of the exponential window is too large, the FRF is distorted. And the modal parameters of the system can not be exactly identified by modal analysis technique. Therefore, it is a difficult problem to determine proper decay rate in impact hammer testing. In this paper, amount of the FRF distortion caused by exponential window is theoretically uncovered. A new circle fitting method is also proposed so that the modal parameters are directly extracted from impulse response spectrum distorted by the exponential-windowed impulse response data. The results by the conventional and proposed circle fitting method are compared through a numerical example.

PVA를 이용한 산업용 모터 고장진단 모니터링 시스템의 가시성을 높이는 방법 (Method for High-visibility of Online Monitoring and Fault Diagnosis System for Industrial Motor using PVA)

  • 고영진;강인원
    • 대한안전경영과학회지
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    • 제22권1호
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    • pp.15-21
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    • 2020
  • Industrial Motors diagnostic equipment is highly dependent on the automation system, so if there are defects in the automation equipment, it can only rely on the operator's intuitive judgment.To help with intuitive judgment, Park's Vactor Approach(PVA) represents the current signal as a pattern of circles, so it can tell if a fault occurs when the circle is distorted. However, the failure to judge the degree of distortion of the circle pattern is the basis of the fault, so it will face difficulties. In this paper, in order to compare the faults of PVA, the period of d-axis current of PVA pulsation was mastered, so that two phase differences occurred in the same signal source. Through experiments, it is confirmed that this is a 90 degree cross formation of PVA, which is convenient for judging from the vision that there is no fault, thus helping the operator to make intuitive judgment.

3 차원 표면의 컬러 인쇄를 위한 공정 변수 영향 분석에 관한 연구 (investigation of process parameter influence on 3D surface coloring)

  • 송민섭;이상호;김효찬;양동열
    • 한국정밀공학회:학술대회논문집
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    • 한국정밀공학회 2004년도 추계학술대회 논문집
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    • pp.1390-1393
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    • 2004
  • In the present industry, three-dimensional colored shape has required for realistic prototype in rapid manufacturing. Z-corporation developed 3D printer which can color three-dimensional prototype but this process can't be adopted to other rapid prototype products and spend much time and cost coloring 3D shape. In this study a new coloring process on three-dimensional surface is proposed for realistic prototype. Three-dimensional surface coloring apparatus is composed of HP ink jet head and X-Y plotter. Distance and angle between ink jet nozzle and 3D surface are set as process parameter. Based on the experiment of process parameters, it is shown that distance and angle affected on printed image on 3D surface. Circle and line shape are chosen as standard image shape because the shape has widely used as standard in 2D printing. Consequently, the distorted image on 3D surface is corrected by transformed input image data.

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3 차원 레이저 보조 밀링을 위한 실린더형 시편의 예열효과에 관한 해석적 연구 (An Analytical Study on the Preheating Effect of Workpiece with Cylindrical Shape for 3-Dimensional Laser-Assisted Milling)

  • 우완식;이춘만
    • 한국정밀공학회지
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    • 제32권2호
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    • pp.173-178
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    • 2015
  • Laser-assisted machining (LAM) is an effective machining method for processing difficult-to-cut materials. Prediction and estimation of preheating effect of the LAM is difficult because of moving heat source. So it is necessary to study the preheating effect of the laser heat source irradiated on the curved surfaces of workpieces of various shape. In this paper, thermal analysis of the LAM for 3-dimentional workpiece with cylindrical shape was performed. The results of this analysis can be applied to obtain the optimal preheating method and path for LAM of 3-dimensional workpiece.

2-Methyl-3-(N-trimethyl ammonium)phenol Iodide의 결정 구조 (The Crystal Structure of 2-Methyl-3-(N-trimethyl ammonium)phenol Iodide)

  • 조성일;윤혜숙;구정회
    • 약학회지
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    • 제24권2호
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    • pp.135-141
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    • 1980
  • The crystal and molecular structure of 2-methyl-3-(N-trimethyl ammonium)phenol iodide, $C_{10}H_{16}NOI, was determined by X-ray diffraction method. The compound crystallizes in the orthorhombic space group $P_{na2}_{1}$ with a=13.327(3), b=12.496(3), C=7.227(2)A and Z=4. A total of 489 independent observed reflections were collected by the automated Four-circle diffractometer and was solved by heavy atom method and refined by anisotropic block-diagonal least-squares method to the R value of 0.04. The benzene ring is slightly distorted from regular hexagon. The I atom and 2-methyl-3-(N-trimethyl ammonium)phenol group is held together by van der Waals forces in the crystal. Intermolecular hydrogen bond is of the type O-H....I with the length 3.35.angs.. Apart from the hydrogen bonding system the molecules are held together by van der Waals forces in the crystal.

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Effects and mechanisms of a mindfulness-based intervention on insomnia

  • Kim, Hye-Geum
    • Journal of Yeungnam Medical Science
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    • 제38권4호
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    • pp.282-288
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    • 2021
  • Medication alone is not sufficient to treat insomnia. In addition, the side effects of sleep medications themselves cannot be ignored during treatment. Insomnia begins with poor sleep quality and discomfort, but as it continues, patients fall into a vicious circle of insomnia with negative thoughts and dysfunctional and distorted perceptions related to sleep. Mindfulness-based intervention for insomnia corrects these sequential cognitive and behavioral processes. The mindfulness technique basically recognizes all the thoughts, feelings, and experiences that occur to us as they are, nonjudgmentally, and then trains them to return to the senses of our body. In this way, while noticing all the processes of the sequential vicious cycle and training them to return to our bodies (e.g., breathing), mindfulness determines whether we are really sleepy or just fatigued. This mindfulness-based intervention can be a useful nonpharmaceutical intervention for insomnia, and its stability and efficacy has been proven by many studies.

여성건강을 위한 개념적 모형 (Conceptual Model for Women s Health)

  • 이경혜
    • 대한간호학회지
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    • 제27권4호
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    • pp.933-942
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    • 1997
  • There has recently been an increased interest in women's health from, various disciplines, with different perspectives presented according to each profession's academic background. This has led to many instances of incorrectly defining, or misinterpretation, of the issues even among professionals. Nurse scholars as well as practitioners who work in women's health care need to have a clear conceptual understanding of women's health in order to build a body of knowledge, delineate curricular activities, and set directions for professional nursing interventions. In addition, a conceptual model that may be directly utilized in practice is needed to maintain and promote women's health issues. The purpose of this study was to apply a Hybrid model, analyzing conceptual definitions and discussions related to women's health gathered from review of the literature. Further to compare analyticals the concepts and properties observed from field work, so as to present a final definition of women's health and, build a conceptual framework for a united comprehensive perspective on the concept as well as on nursing practice. Data collection and analysis consisted of a theoretical stage, field work stage, and final analysis. A heterogeneous group of professionals and lay persons, 39 in all, participated in the field work. Study findings Include several subconcepts under the concept of women's health : a woman's whole life, holistic health, quality of life, awareness of being a woman, individual nursing, self care ability, reproductive health, and family health. Thus, a comprehensive definition was built, 1. e., "Women's health care be defined as improvement in the quality of life of women through attainment of holistic health throughout the life span. With reproductive health at the core, the concept is directly related to family and national health, and includes taking care of one's own health based on awareness of being a woman and utilizing self care activities. Women's health care issues are unique and allow various responses, therefore women's health professionals need to apply individual approaches to reach solutions in attaining holistic health and improving quality of life." The constructual factors of women's health were found to be reproductive functions, diseases more common in woman, self actualization, mental health, women's health policies, sexuality, midlife changes, and marital relations, with each factor having more than three properties. Positive factors affecting women's health were found to be a normal childbearing process, a healthy lifestyle, active health management, health information, support, and resources, and interpersonal relationships. Negative factors were found to be overwhelming role stress, cultural oppression, gender inequality, distorted sexual identity, economic difficulties, misuse and/or abuse of substances, and stress. The model of women's health may be visualized as a balance scale set upon a woman's life, supporting 4 concentric circles. The innermost circle and second circle incorporate conceptual definitions of women's health, and the outer two circles represent the constructional factors and properties of women's health. Each circle has its own color that symbolizes the conceptual meaning. Positive and negative factors are represented as weights at either end of the scale, and are affected by nursing intervention, i. e., health and wellness increase when positive factors are stronger, whereas disease and illness increase when negative factors are stronger. This model is only a preliminary effort and requires much discussion and testing to be further developed. Continuous research is also required.

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초정밀가공기용 타원 진동절삭 공구대의 설계 및 성능실험 (Design and Test of Elliptical Vibration Assisted Cutting Tool Post for Ultra-precision Machines)

  • 이대희;김호상;김의중;오창진
    • 한국정밀공학회:학술대회논문집
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    • 한국정밀공학회 2004년도 추계학술대회 논문집
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    • pp.261-264
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    • 2004
  • This paper presents the design and test of elliptical vibration assisted cutting tool post. It is actuated by two piezoelectric actuators which are connected to the moving part through the elastic hinge with its role of imposing the preliminary pressures. These two actuators are located at right angles so that the resulting tool tip moves like a two-dimensional ellipse. Also, the tool post is activated within the region of linear actuation in order to overcome the distorted elliptical motion. For the precise measurement of the displacement of the tool tip, three-dimensional experimental apparatus was designed and the strokes of the tool post in major and minor axes were measured. The results show that the tool post can produce the variety of vibration locus from a circle with a radius of 5 ${\mu}{\textrm}{m}$ to an ellipse with a major axis, a =10 ${\mu}{\textrm}{m}$, and a minor axis, b =2.5 ${\mu}{\textrm}{m}$

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CR X선 영상의 복합잡음 감소에 관한 연구 (Mixed Noise Reduction Filters for CR Images)

  • 민정환;정회원;김정민
    • 대한방사선기술학회지:방사선기술과학
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    • 제30권1호
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    • pp.1-6
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    • 2007
  • 인위적으로 noise factor를 주고 그 위에 촬영을 하여 노이즈와 영상의 복합물을 만들었다. 그 후 Low Pass Filter(LPF)와 Median Filter(MF)의 두 종류의 필터를 통하여 노이즈를 제거하고 노이즈를 나타내는 지표로 Signal To Noise Ratio(SNR), Peak Signal to Noise Ratio(PSNR), Mean Square Error(MSE)를 비교하였다. 또한 Median Filter의 kernel size에 따라서도 노이즈제거효과를 평가하였다. 각각의 처리된 영상과 원 영상을 비교하여 원 영상에 가까운 영상을 찾아봄으로서 어떤 필터가 유용하며 어떤 주파수대를 제거해야 하는가를 알고자 실험하였다. Cutoff frequency가 다른 필터를 비교 했을 때 noise power 값에는 상관없이 cutoff frequency $2/3\pi{\sim}3/4\pi$까지가 원 영상에 가까우면서 SNR, PSNR이 좋다. 따라서 높은 filter 효과를 나타낸다고 할 수 있다. Median filter의 kernel size가 커짐에 따라서 SNR 값이 커지며 반대로 MSE의 값이 작아져 filter 효과는 좋아 짐을 알 수 있다. 의료 영상에 filter를 적용하는 것에 대해서 대부분의 영상들이 filter 적용 후에 왜곡된 상이 되곤 하였다. 의료 영상은 다른 영상과는 달리 공간 분해능을 유지하면서 평활화(노이즈 제거)하는 것이 중요한 문제이다. SNR 등 정량적 지표에 의한 비교와 함께 시각적 평가가 병행되어야 할 필요가 있다.

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