• Title/Summary/Keyword: Roberts

Search Result 154, Processing Time 0.025 seconds

Antenna factors of short dipole antennas with roberts balun (Roberts밸런을 갖는 단축 다이폴 안테나의 안테나 인자)

  • 김기채
    • The Journal of Korean Institute of Communications and Information Sciences
    • /
    • v.22 no.3
    • /
    • pp.532-538
    • /
    • 1997
  • Exactly aclculated antenna factors are requeired for determining EMI levels in an actual radiated emission test. In this paper, the antenna factors of short dipole antennas above the ground plane are calculated theoretically for the antenna with Roberts balun specified ANSI C63.5 regulation. Also treated is a half-wavelength dipole antenna with Roberts balun to compare the antenna factors with those of resonant dipole antenna. In formulationof antenna factors the antenna is treated as the boundary value problem of Maxwells equations and is analyzed by the Galerkins method of moments. The balun is treated using circuit theory based on power transmission mismatch.

  • PDF

Measurement of Surface Energy and Intrinsic Work of Adhesion Using Johnson-Kendall-Roberts (JKR) Technique (Johnson-Kendall-Roberts (JKR) 기법을 이용한 표면 에너지 및 고유접착에너지 측정)

  • Lee, Dae Ho;Lee, Dong Yun;Cho, Kilwon
    • Journal of Adhesion and Interface
    • /
    • v.5 no.3
    • /
    • pp.18-22
    • /
    • 2004
  • By using JKR technique, the surface energy of a solid material and the intrinsic work of adhesion between two materials were determined. JKR technique is based on the contact mechanics, and is now being accepted as a new method which can overcome the demerits of the existing test methods such as contact angle measurement and other adhesion test. In this study, the surface energy of polydimethylsiloxane (PDMS) is measured by JKR method and the experimental results and the applicability of JKR apparatus were discussed.

  • PDF

A Study on Pixel Brightness Transfer Function for Low Light Edge Detection (저조도 에지 검출을 위한 화소 휘도 변환 함수에 관한 연구)

  • Ko, You-Hak;Kwon, Se-Ik;Kim, Nam-Ho
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
    • /
    • 2017.05a
    • /
    • pp.787-789
    • /
    • 2017
  • Edge detection is used in many applications such as image analysis, pattern recognition and computer vision. Existing edge detection methods, there is such Sobel, Prewitt, Roberts, and LoG(Laplacian of Gaussian). In the conventional edge detection method, edge detection is insufficient because the change of the pixel brightness is small when the original image is in low illumination. Therefore, in this paper, we proposed a function to convert the pixel brightness of low illumination image to solve this problem. And it was compared by applying the conventional methods Sobel, Prewitt, Roberts, LoG(Laplacian of Gaussian) to determine the performance of the pixel brightness transform function.

  • PDF

A Study on Edge Detection using Pixel Brightness Transfer Function in Low Light Level Environments (저조도 환경에서 화소의 휘도 변환 함수를 이용한 에지 검출에 관한 연구)

  • Lee, Chang-Young;Kim, Nam-Ho
    • Journal of the Korea Institute of Information and Communication Engineering
    • /
    • v.19 no.7
    • /
    • pp.1680-1686
    • /
    • 2015
  • Edge detection is an essential preprocessing for most image processing application, and there are several existing detection methods such as Sobel, Roberts, Laplacian, LoG(Laplacian of Gaussian) operators, etc. Those existing edge detection methods have not given satisfactory results since they do not offer enough pixel brightness change in low light level environment. Therefore, in this study new algorithms using brightness transfer function in the preprocessing and for edge detection applying standard deviation and average-weighted local masks are proposed. In addition, the performance of proposed algorithms was evaluated in comparison with the existing edge detection methods such as Sobel, Roberts, Prewitt, Laplacian, LoG operators.

A Comparative Study on the Similarities and Differences between Western Christianity and Chinese Culture in Taiping Religion (태평천국운동에 있어서 서양 기독교와 중국 문화의 상관관계에 대한 비교 연구)

  • Kim, Sukjoo
    • Cross-Cultural Studies
    • /
    • v.42
    • /
    • pp.475-503
    • /
    • 2016
  • This paper explores the extent of the Christian influence of Liang Fa's Quanshiliangyan and Isaachar J. Roberts on Hong Xiuquan and the Taiping Movement. Hong's religious background was in Confucianism, but when he encountered Liang Fa's Quanshiliangyan, he identified with Christianity. Subsequently, he studied with Roberts for two or three months. The religious experiences of Hong served as motives for the establishment of the Society of God Worshippers and the Taiping Movement. Therefore, this paper develops Liang's key ideas and Roberts' main teachings, describes Hong's beliefs and the actual practices of the Taiping Movement, as found in official documents of the Taipings, and compares their similarities and differences. Hong and his leaders received the new ideas of Christianity at the expense of their traditional culture. Furthermore, they attempted to combine Chinese culture with Christianity, as well as believe in Christianity to the limits of their understanding. Finally, this study finds that even though the Quanshiliangyan and Isaachar J. Roberts may have given the Taiping Movement its religious form and driving force, the theological vision of both Liang and Hong that also emerged from their Chinese culture energized the Taipings. The Taiping Movement resulted from a deliberate synthesis of Christian ideas and native Chinese practices in China.

A Study on Edge Detection using Gray-Level Transformation Function (그레이 레벨 변환 함수를 이용한 에지 검출에 관한 연구)

  • Lee, Chang-Young;Kim, Nam-Ho
    • Journal of the Korea Institute of Information and Communication Engineering
    • /
    • v.19 no.12
    • /
    • pp.2975-2980
    • /
    • 2015
  • Edge detection is one of image processing techniques applied for a variety of purposes in a number of areas and it is used as a necessary pretreatment process in most applications. Detect this edge has been conducted in various fields at domestic and international. In the conventional edge detection methods, there are Sobel, Prewitt, Roberts and LoG, etc using a fixed weights mask. Since conventional edge detection methods apply the images to the fixed weights mask, the edge detection characteristics appear somewhat insufficient. Therefore in this study, to complement this, preprocessing using gray-level transformation function and algorithm finding final edge using maximum and minimum value of estimated mask by local mask are proposed. And in order to assess the performance of proposed algorithm, it was compared with a conventional Sobel, Roberts, Prewitt and LoG edge detection methods.

A Study on Edge Detection Algorithm using Mask Shifting Deviation (마스크 이동 편차를 이용한 에지 검출 알고리즘에 관한 연구)

  • Lee, Chang-Young;Kim, Nam-Ho
    • Journal of the Korea Institute of Information and Communication Engineering
    • /
    • v.19 no.8
    • /
    • pp.1867-1873
    • /
    • 2015
  • Edge detection is one of image processing techniques applied for a variety of purposes in a number of areas and it is used as a necessary pretreatment process in most applications. In the conventional edge detection methods, there are Sobel, Prewitt, Roberts and LoG, etc using a fixed weights mask. Since conventional edge detection methods apply the images to the fixed weights mask, the edge detection characteristics appear somewhat insufficient. Therefore in this study, an algorithm for detecting the edge is proposed by applying the cross mask based on the center pixel and up, down, left and right mask based on the surrounding pixels of center pixel in order to solve these problems. And in order to assess the performance of proposed algorithm, it was compared with a conventional Sobel, Roberts, Prewitt and LoG edge detection methods.

A Study on Mask-based Edge Detection Algorithm using Morphology (모폴로지를 이용한 마스크 기반 에지 검출 알고리즘에 관한 연구)

  • Lee, Chang-Young;Kim, Nam-Ho
    • Journal of the Korea Institute of Information and Communication Engineering
    • /
    • v.19 no.10
    • /
    • pp.2441-2449
    • /
    • 2015
  • In this digital information era, utilization of images are essential for various media, and the edge is an important characteristical information of an object in images that includes the size, location, direction and etc. Many domestic and international studies are being conducted in order to detect these edge. Existing edge detection methods include Sobel, Prewitt, Roberts, Laplacian, LoG and etc. which apply fixed weight value. As these existing edge detection methods apply fixed weight mask to the image, edge detection characteristic appears slightly insufficient. Accordingly, in order to supplement these problems, this study used bottom-hat transformation from mathematical morphology and opening operation in improving the image and proposed an algorithm that detects for the edge after calculating mask-based gradient. And to evaluate the performance of the proposed algorithm, a comparison was made against the existing Sobel, Roberts, Prewitt, Laplacian, LoG edge detection methods, in illustrating visual images, and similarities were compared by calculating the MSE value based on the standard of each image.