• Title/Summary/Keyword: angle resolution

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Primary Angle-Closure Glaucoma in a Maltipoo Dog

  • Jiwoo Park;Manbok Jeong
    • Journal of Veterinary Clinics
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    • v.40 no.3
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    • pp.221-224
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    • 2023
  • A two-year-old spayed female Maltipoo dog was presented with a two-month duration of glaucoma in the right eye. On the first presentation, menace response and dazzle reflex were absent in the right eye, but it was present in the left eye. Slit-lamp biomicroscopy showed buphthalmia, mild corneal edema, and conjunctival and episcleral hyperemia in the right eye. The intraocular pressures were 70 mmHg and 30 mmHg in the right and left eyes, respectively. On the gonioscopic and high-resolution ultrasound examinations, both the iridocorneal angle and ciliary cleft were completely closed in the right eye. However, gonioscopy revealed an opened iridocorneal angle even with some broader base of pectinate ligament fiber, but high-resolution ultrasound showed a narrowed ciliary cleft and increased contact of the iris base with the limbal cornea in the left eye. Based on these results, a diagnosis of primary angle-closure glaucoma was made in both eyes. This case report highlighted the importance of evaluating the ciliary cleft with high-resolution ultrasound as a critical diagnostic and prognostic role in canine glaucoma.

Spectral Resolution Enhancement of Acousto-Optic Tunable Filter(AOTF) using Incident Angle Variation (음향광학변조필터의 입사각 변화를 이용한 분해능 향상 방법)

  • You, Jang-Woo;Ahn, Jeong-Ho;Kim, Dae-suk;Kwak, Yoon-Keun;Kim, Soo-Hyun;Lee, Yun-Woo;Whang, In-Duk
    • Proceedings of the KSME Conference
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    • 2004.11a
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    • pp.607-612
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    • 2004
  • Spectral resolution enhancement method of Acousto-Optic Tunable Filter (AOTF) using incident light angle variation is described. AOTF is a small, mechanically rigid, high speed and spectral resolution light tunable filter. The basic theory of AOTF and its experimental verification is described. AOTF can generate two opposite polarized light simultaneously which wavelength can be changed by incident angle variation. We focused on the common region of two filtered light at the specific incident angle. This region can be used to enhance the spectral resolution of AOTF.

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Neural network based distortion correction of wide angle lens (신경회로망을 이용한 광각렌즈의 왜곡보정)

  • 정규원
    • 제어로봇시스템학회:학술대회논문집
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    • 1996.10b
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    • pp.299-301
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    • 1996
  • Since a standard lens has small sight angle, a fish-eye lens can be used in order to obtain wide sight angle for the robot vision system. In spite of the advantage, the image through the lens has variable resolution; the central information of the lens is of high resolution, but the peripheral information is of low resolution. Owing to this difference of resolution, the variable resolution image should be transformed to a uniform resolution image in order to determine the positions of the objects in the image. In this work, the correction method for the distorted image is presented and the performance is analyzed. Furthermore, the camera with a fish eye lens can be used to determine the real world coordinates. The performance is shown through experiments.

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Design of SONAR Array for Detection of Bottoming Cylindrical Objects (착저 원통형 물체 탐지를 위한 소나 어레이 설계)

  • Kim, Sunho;Jung, Jangwon;On, Baeksan;Im, Sungbin;Seo, Iksoo
    • Journal of the Institute of Electronics and Information Engineers
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    • v.54 no.3
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    • pp.15-21
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    • 2017
  • In the active SONAR system, various studies have been carried out to enhance the resolution of a received signal. In order to obtain higher resolution for detecting a bottoming cylindrical object, the design of a planar array for SONAR is investigated in this paper. It is necessary to employ planar structures for SONAR array to obtain narrower beam pattern which gives high resolution. In this study, the transmit frequency of each acoustic transducer, which consists of an array is 13 kHz. For efficient detection of a target of an asymmetric size, the concept of areal angle is applied, which considers resolution according to both azimuth and elevation angles in array design. In the design, the areal angle is first investigated to satisfy the resolution requirements, and then based on the value of areal angles, the azimuth angle and the elevation angle are calculated respectively to design an array.

Wide-angle optical design using high-resolution uncooled thermal detector

  • Lee, Jonghoon
    • Journal of the Korea Society of Computer and Information
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    • v.22 no.11
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    • pp.31-37
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    • 2017
  • In this paper, we propose efficient design and construction of an infrared wide angle optical system with low distortion utilizing a high resolution detector for automobile application. The operational convenience and the recognition ability have been improved significantly by applying the high resolution uncooled thermal detector with wide angle optical design. The active ahtermalization mechanism is implemented so that the adjustment of the optical component of the system is to be made automatically according to the temperature change by motorized control. The modulation transfer function (MTF) is about 50% at the Nyquist frequency close the diffraction limit. The distortion is less than 5% at the edge field. As a result, a high-resolution uncooled thermal optical system with wide field of view (FOV) is assembled, aligned and its performance is tested successfully.

Linerly Graded Encoder for High Resolution Angle Control of SRM Drive

  • Lee, Sang-Hun;Lim, Heon-Ho;Park, Sung-Jun;Ahn, Jin-Woo;Kim, Cheul-U
    • KIEE International Transaction on Electrical Machinery and Energy Conversion Systems
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    • v.11B no.4
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    • pp.185-192
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    • 2001
  • In SRM drive, the ON·OFF angles of each phase switch should be accurately controlled in order to control the torque and speed stably. The accuracy of the switching angles is dependent upon the resolution of the encoder and the sampling period of the microprocessor, that are used to provide the information of the rotor position and to control the SRM power circuit, respectively. However, as the speed increases, the amount of the switching angle deviation from the preset values is also increased. Therefore, the low cost encoder suitable for the practical and stable SRM drive is proposed and the control algorithm to provide the switching signals using the simple digital logic circuit is also presented in this paper, As a result, a stable high speed SRM drive can be achieved by the high resolution switching angle control and it is verified from the experiments that the proposed encoder the logic controller can be a powerful candidate for the practical low cost SRM drive.

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A Study on DOA and Delay Time Presumption based on Average Method (평균방법에 근거한 DOA와 지연시간추정에 관한 연구)

  • 이관형;송우영
    • Journal of the Korea Society for Simulation
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    • v.13 no.2
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    • pp.1-12
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    • 2004
  • This paper estimated the arrival angle and electric wave delay time using the space method law and the directions of arrival (DOA) estimation algorithm in case of signal correlation. Space method law is the method used to repress cross correlation before applying the weight value to the receiving signal. The values of the diagonal elements in the correlation matrix were averaged to replace as the diagonal elements value. In the area of wireless communication or mobile communication, there are high correlations in case of low delay time difference in multiple waves. This causes the quality of the communication to drop due to interference with the desired signal elements. This paper estimated the arrival angle and electric wave delay time using the space method law and the MUSIC algorithm. With the arrival angle algorithm, the arrival angle cannot be estimated below 5 in case of signal correlations because the angle resolution capacity decreases accordingly. The super resolution capacity was estimated to determine the arrival angle below 5 in this paper. In addition, the proposed algorithm estimated the short delay time difference to be below 20ns.

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Analysis of BRD Components Over Major Land Types of Korea

  • Kim, Sang-Il;Han, Kyung-Soo;Park, Soo-Jea;Pi, Kyoung-Jin;Kim, In-Hwan;Lee, Min-Ji;Lee, Sun-Gu;Chun, Young-Sik
    • Korean Journal of Remote Sensing
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    • v.26 no.6
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    • pp.653-664
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    • 2010
  • The land surface reflectance is a key parameter influencing the climate near the surface. Therefore, it must be determined with sufficient accuracy for climate change research. In particular, the characteristics of the bidirectional reflectance distribution function (BRDF) when using earth observation system (EOS) are important for normalizing the reflected solar radiation from the earth's surface. Also, wide swath satellites like SPOT/VGT (VEGETATION) permit sufficient angular sampling, but high resolution satellites are impossible to obtain sufficient angular sampling over a pixel during short period because of their narrow swath scanning. This gives a difficulty to BRDF model based reflectance normalization of high resolution satellites. The principal objective of the study is to add BRDF modeling of high resolution satellites and to supply insufficient angular sampling through identifying BRDF components from SPOT/VGT. This study is performed as the preliminary data for apply to high-resolution satellite. The study provides surface parameters by eliminating BRD effect when calculated biophysical index of plant by BRDF model. We use semi-empirical BRDF model to identify the BRD components. This study uses SPOT/VGT satellite data acquired in the S1 (daily) data. Modeled reflectance values show a good agreement with measured reflectance values from SPOT satellite. This study analyzes BRD effect components by using the NDVI(Normalized Difference Vegetation Index) and the angle components such as solar zenith angle, satellite zenith angle and relative azimuth angle. Geometric scattering kernel mainly depends on the azimuth angle variation and volumetric scattering kernel is less dependent on the azimuth angle variation. Also, forest from land cover shows the wider distribution of value than cropland, overall tendency is similar. Forest shows relatively larger value of geometric term ($K_1{\cdot}f_1$) than cropland, When performed comparison between cropland and forest. Angle and NDVI value are closely related.

A study on the resolution of the laser range finder (레이저 거리계의 분해능에 관한 연구)

  • Cha, Yeong-Yeop;Yu, Chang-Mok
    • Journal of Institute of Control, Robotics and Systems
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    • v.4 no.1
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    • pp.82-87
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    • 1998
  • In this study, the theoretical resolution analysis of an active vision system using laser range finder is performed for surrounding recognition and 3D data acquisition in unknown environment. In the result, the resolution of range data in laser range finder is depend on the distance between lens center of CCD camera and light emitter, view angle, beam angle, and parameters of CCD camera. The theoretical resolutions of the laser range finders of various types which are based on parameters effected resolution are calculated and experimental results are obtained in real system.

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Design of High-resolution Wide-angle Lenz Module, and Image Distortion Compensation for Smart NUX (스마트 NUX용 고해상도 광각렌즈모듈 및 영상왜곡보정 설계)

  • Lee, Jae-Gon;Kang, Min-Goo;Kim, Won-Kyu;Lee, Kyung-Taek
    • The Journal of the Korea institute of electronic communication sciences
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    • v.7 no.5
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    • pp.999-1004
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    • 2012
  • In this paper, camera modules and lens's images were analyzed for the compensation of distortion image by wide angle lens based WDR(Wide Dynamic Range) with high resolution sensor(2-Mega CMOS Image sensor). Due to wide angle ($176^{\circ}$) of designed wide angle camera modules, the compensation result of distorted image was analyzed, and the application of these modules was proposed for smart NUX(Natural User eXprience).