• Title/Summary/Keyword: Circular Object

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A study on Influence Parameter of Seismic Performance for Circular RC Bridge Piers (원형 철근콘크리트 교각의 내진성능 영향인자에 관한 연구)

  • Lee, Dae-Hyoung;Park, Chang-Kyu;Kim, Hyun-Jun;Chung, Young-Soo
    • Proceedings of the Earthquake Engineering Society of Korea Conference
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    • 2005.03a
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    • pp.292-299
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    • 2005
  • This paper presents evaluation of seismic design code for AASHTO, Eurocode 8, NZS 3101, and ATC-32 and influence of parameter such as confinement steel ratio, axial force ratio, aspect ratio and longitudinal steel ratio. These seismic design code prescribe confinement steel ratio for appropriate seismic performance which is considered various design parameter. But there is doubt that these parameters are considered rationally in seismic design code. The object of this research is rational evaluation of seismic performance by analysis of existing related experimental research. According to this research, most influence parameter of seismic performance is axial force ratio.

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A Study of P/2010 A2 Dust Cloud : Possibly Impact Triggered Dust Particles

  • Ishiguro, Masateru
    • The Bulletin of The Korean Astronomical Society
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    • v.35 no.1
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    • pp.87.1-87.1
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    • 2010
  • Main-belt comets (hereafter MBCs) are one of the hottest topics in the solar system astronomy. They are objects orbiting in the main asteroid belt which show cometary activity. Unlike most comets, which spend most of their orbit beyond 5AU from the Sun, MBCs follow near-circular orbits within the asteroid belt that are indistinguishable from the orbits of major population of the asteroids. P/2010 A2, the fifth MBC, was discovered by on January 6, 2010 by Lincoln Near-Earth Asteroid Research. It passed its perihelion at 2.01AU on December 3, 2009, about a month before it was discovered. With an aphelion of only 2.6 AU, P/2010 A2 spends all of its time inside of the frostline ~2.7 AU. We made observations of P/2010 A2 with Nishi-Harima Astronomical Observatory 2-m telescope only a week after the discovery. From the observed images, we found that the dust cloud was composed of large particles (>1mm) impulsively ejected between March and June, 2009. No coma was detected by our observations, suggesting that this object was no longer active. Consequently, we conjecture that these dust particles could be released by the impact collision among asteroids.

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Optimum Seismic Design of Reinforced Concrete Piers Considering Economy and Constructivity (내진설계시 경제성 및 시공성을 고려한 RC 교각의 최적설계)

  • 조병완;김영진;윤은이
    • Proceedings of the Korea Concrete Institute Conference
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    • 2000.04a
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    • pp.479-484
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    • 2000
  • In this study, optimal design of reinforced concrete piers under seismic load is numerically investigated. Object function is the area of the concreate-section. Design variables are the total area of reinforcement and concrete-section dimension(Circular section diameter). Constraints of the design strength of the column, longitudinal reinforcement ratio and lower and upper bounds on the design variables are imposed. The reinforcement concrete column is analysed and designed by the Ultimated Strength Design method and load combination involving dead, live, wind and seismic load is used. For numerical optimization, ADS(Garret N, Vanderplaats_ routine is used. From the result of numerical examples, the concrete-section dimension was reduced, but longitudinal reinforcement was not changed. The results show that confinement reinforcement was reduced and confinement reinforcement spacing is increased. The higher strength of reinforcement used, the more concrete-section area was reduced.

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A Novel Visual Servoing Approach For Keeping Feature Points Within The Field-of-View (특징점이 Field of View를 벗어나지 않는 새로운 Visual Servoing 기법)

  • Park, Do-Hwan;Yeom, Joon-Hyung;Park, Noh-Yong;Ha, In-Joong
    • Proceedings of the KIEE Conference
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    • 2007.04a
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    • pp.322-324
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    • 2007
  • In this paper, an eye-in-hand visual servoing strategy for keeping feature points within the FOV(field-of-view) is proposed. We first specify the FOV constraint which must be satisfied to keep the feature points within the FOV. It is expressed as the inequality relationship between (i) the LOS(jine-of-sight) angles of the center of the feature points from the optical axis of the camera and (ii) the distance between the object and the camera. We then design a nonlinear feedback controller which decouples linearly the translational and rotational control loops. Finally, we show that appropriate choice of the controller gains assures to satisfy the FOV constraint. The main advantage of our approach over the previous ones is that the trajectory of the camera is smooth and circular-like. Furthermore, ours can be applied to the large camera displacement problem.

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A Representation of the Nonlinear Axis in the G. C (G. C에 있어서 비선형축의 표현)

  • 조동욱;최병욱
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.13 no.4
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    • pp.309-321
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    • 1988
  • This paper proposes on the algorithm of axis equation & radius function for the G.C representation which describes the curved objects with circular cross section. Object combined with linear and nonlinear parts is detached by clustering from depth data & axis points is extracted by normal vecter of the surface mask patches. In ths case of nonlinear axis point, axis equation is described by Hermite curve & the effectiveness of this paper is demonstrated by serveral experiments.

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Improvement of corrosion resistance and hardening the back ferrule surface by plasma treatment (Back ferrule 의 내식성과 체결시 기계적특성을 만족시키는 최적의 플라즈마 침질탄화공정조건의 확립)

  • Lee, In-Seop;Debnath, Sanket
    • Proceedings of the Korean Institute of Surface Engineering Conference
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    • 2012.05a
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    • pp.179-180
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    • 2012
  • Back ferrule is a circular ring shaped metallic object which is used for fastening, joining or reinforcement during the tube fitting as well as to prevent leakage. Therefore, during tube fitting the leading edge of the back ferrule should be sufficiently hard enough to prevent leakage. In our research, we concentrated the improvement of two major factors. Firstly, to improve the surface hardness of the back ferrule made by AISI 316 Stainless Steel. Secondly, the enhancement of corrosion resistance of back ferrule after plasma treatment. Initially, the corrosion resistance and hardness of the back ferrule (both commercial and without treated) was not good enough for tube fitting but after applying plasma treatment with suitable conditions on ferrule, we improved the corrosion resistance and hardness of the back ferrule dramatically.

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A Study on the Analysis of the Error in Photometric Stereo Method Caused by the General-purpose Lighting Environment (測光立體視法에서 범용조명원에 기인한 오차 해석에 관한 연구)

  • Kim, Tae-Eun;Chang, Tae-Gyu;Choi, Jong-Soo
    • Journal of the Korean Institute of Telematics and Electronics B
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    • v.31B no.11
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    • pp.53-62
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    • 1994
  • This paper presents a new approach of analyzing errors resulting from nonideal general-purpose lighting environment when the Photometric Stereo Method (PSM) is applied to estimate the surface-orientation of a three-dimensional object. The approach introduces the explicit modeling of the lighting environment including a circular-disk type irradiance object plane and the direct simulation of the error distribution with the model. The light source is modeled as a point source that has a certain amount of beam angle, and the luminance distribution on the irradiance plane is modeled as a Gaussian function with different deviation values. A simulation algorithm is devised to estimate the light source orientation computing the average luminance intensities obtained from the irradiance object planes positioned in three different orientations. The effect of the nonideal lighting model is directly reflected in such simulation, because of the analogy between the PSM and the proposed algorithm. With an instrumental tool designed to provide arbitrary orientations of the object plane at the origin of the coordinate system, experiment can be performed in a systematic way for the error analysis and compensation. Simulations are performed to find out the error distribution by widely varying the light model and the orientation set of the object plane. The simulation results are compared with those of the experiment performed in the same way as the simulation. It is confirmed from the experiment that a fair amount of errors is due to the erroneous effect of the general-purpose lighting environment.

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Ellen Olenska as the objet petit a and the Relationship Between Man and Woman in Edith Wharton's The Age of Innocence (대상 소타자로 작용하는 엘런 올렌스카 - 『순수의 시대』에 나타난 남녀관계)

  • Lee, Misun
    • Cross-Cultural Studies
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    • v.53
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    • pp.73-102
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    • 2018
  • The purpose of this study was to explain, using Jacques Lacan's theory of desire, how Ellen Olenska functions as the object petit a in her relationship with Newland Archer and to connect the impossibility of Newland and Ellen's love with the impossibility of desire, in Edith Wharton's The Age of Innocence. In New York society in the 1870s, the unpleasant truth was avoided, personal opinions were excluded, no room for imagination existed, and other-ness was expelled. In that society, Newland realized that true love and true emotions were lacking in his life. For Newland, Ellen was the gap in New York society and the object that could fill that gap. Ellen functioned as the object petit a. But the romance between Newland and Ellen was forbidden in New York society, where everything was dominated by strict social codes, and especially because Newland was engaged to Ellen's cousin, May Welland. Ellen became inaccessible to Newland and this set Newland's desire for Ellen in motion. He idealized Ellen as the objet petit a, based on the fantasy that she would fill the void in his life. However, at every critical moment, Newland delayed unification with Ellen by resorting to social codes. His actions betrayed that the goal of his desire was not the fulfillment, but the reproduction of desire, with its circular movement. His decision not to see Ellen in Paris again at the end of the novel can be interpreted as Newland's effort to maintain Ellen as the inaccessible object, objet petit a, forever. It is this impossibility of desire that the romance of Newland and Ellen is predicated upon. Another purpose of this study was to expand this impossibility of desire to the relationship between man and woman and to interpret The Age of Innocence as a story showing the characteristics of the relationship between the sexes. The relationship between Newland and Ellen shows that there is no harmonious relationship between the sexes and that woman exists only as a fantasy object, objet petit a for man.

Development of Automatic Hole Position Measurement System using the CCD-camera (CCD-카메라를 이용한 홀 변위 자동측정시스템 개발)

  • 김병규;최재영;강희준;노영식
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2004.10a
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    • pp.127-130
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    • 2004
  • For the quality control of the industrial products, an automatic hole measuring system has been developed. The measurement device allows X-Y movement due to contact forces between a hole and its own circular cone and the device is attached to an industrial robot. Its measurement accuracy is about 0.04mm. This movement of the plate is measured by two LVDT sensor system. But this system using the LVDT sensors is restricted by high cost and precision of measurement and correspondence of environment so particularly, a vision system with CCD-Camera is discussed in this paper for the above mentioned purpose. The device consists of two of two links jointed with hinge pins basically and, they guarantee free movement of the touch prove attached on the second link in the same plane. These links are returned to home position by the spring plungers automatically after each process for the next one. On the surface of the touch prove, it has a circular white mark for camera recognition. The system detect and notify the center coordinate of capture mark image through the image processing. Its measuring accuracy has been proved to be about $\pm$0.01mm through the repeated implementation over 200 times. This technique will shows the advantage of touch-indirect image capture idea using cone-shaped touch prove in various symmetrical shaped holes particulary, like tapped holes, chamfered holes, etc As a result, we attained our object in a view of the accuracy, economical efficiency, and functionality

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General Theory for Enhancing the Transmission Efficiency through Small Apertures (소형 개구의 투과효율 향상을 위한 일반 이론)

  • Cho, Young-Ki
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.25 no.11
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    • pp.1113-1120
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    • 2014
  • In this paper, general methods for enhancing the transmission efficiency through the small subwavelength aperture in an infinite conducting plane are considered first by use of the transmission-resonant aperture like the ridged circular aperture structure, second by employing the transmission-resonant cavity structure. In particular, the maximum transmission cross section is found to be $\frac{2G{\lambda}^2}{4{\pi}}[m^2]$ for the two structures, where G is the gain of the aperture in the output half space. As experimental works, the impedance matching characteristics are investigated for the cases that above two structures are incorporated as a potential near field microscopic probe in the waveguide end. As a complementary problem to the above transmission-resonant aperture problem, some discussions are also given on the scattering resonance by the scattering object much smaller than the wavelength. This discussion may provide a good understanding of the physics for the phenomena that the maximum scattering cross section is much larger than the physical size of the atom in atomic physics area.