• 한국임상수의학회지
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• 제40권3호
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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.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2004년도 추계학술대회
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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.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1996년도 한국자동제어학술회의논문집(국내학술편); 포항공과대학교, 포항; 24-26 Oct. 1996
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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.

• 전자공학회논문지
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• 제54권3호
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• pp.15-21
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• 2017

능동 소나시스템에서 수신 신호의 해상도를 높이기 위한 방법은 다양하게 연구되어 왔다. 본 논문에서는 착저 물체의 탐지 해상도를 높이기 위한 방법으로 소나의 평면 배열 (planar array) 설계를 수행하였다. 해상력이 높은 좁은 형태의 빔 패턴을 얻기 위해서는 평면 형태의 어레이를 고려하는 것이 필요하다. 어레이를 구성하는 개별 음향 트랜스듀서의 송신 주파수는 13 kHz를 사용하였다. 비대칭 크기를 갖는 목표물의 효율적인 탐지를 위해 어레이 디자인에서 방위각(azimuth angle)과 고도각(elevation angle)에 따른 해상도를 동시에 고려하기 위해 areal angle 개념을 사용하였다. 그에 따라 목표 해상도를 만족하는 areal angle을 먼저 구하고 이를 역산하여 각각 목표 방위각과 고도각을 계산하여 어레이의 설계를 진행하였다.

• 한국컴퓨터정보학회논문지
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• 제22권11호
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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.

• KIEE International Transaction on Electrical Machinery and Energy Conversion Systems
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• 제11B권4호
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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.

• 한국시뮬레이션학회논문지
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• 제13권2호
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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.

• 대한원격탐사학회지
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• 제26권6호
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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.

• 제어로봇시스템학회논문지
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• 제4권1호
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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.

• 한국전자통신학회논문지
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• 제7권5호
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• pp.999-1004
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• 2012

본 논문에서는 광각렌즈기반의 WDR(Wide Dynamic Range)인 2M(Mega)급 CMOS 이미지 센서를 통해 왜곡영상을 보정하는 카메라 모듈의 설계와 렌즈영상의 성능을 분석한다. 또한, 설계한 광각렌즈모듈의 광각렌즈($176^{\circ}$) 특성으로 인한 왜곡영상의 보정된 결과를 분석하였으며, 카메라 모듈의 스마트 NUX(Natural User eXprience) 활용방안을 제안하였다.