• 방송공학회논문지
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• 제2권1호
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• pp.16-23
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• 1997

HDTV의 다음세대 TV로서 주목받고 있는 3D TV의 구현을 위한 주요 기술중 보는이의 시점에 해당하는 영상을 보여주는 다시점 입체영상표시가 중요한 연구대상으로 대두되고 있다. 본 논문에서는 다시점 입체영상표시를 구현하기 위한 기존방법들의 문제점으로 지적되는 많은 연산량 문제를 해결할 수 있는 새로운 알고리즘을 제안한다. 다시점 영상모음을 영상 공간축에서 을로 다운 샘플링(down sampling )하여 다해상도 영상 피라미드를 만들고, 이를 바탕으로 저해상도 EPI에서부터 대응점들을 탐색하고, 그에 해당하는 상위 해상도에서는 하위 해상도에서 탐색한 결과를 확인·교정해 가는 방법을 사용하므로써, 기존의 방법보다 고속처리가 가능하며, 잡음에도 강인한 기법을 제안한다.

• 로봇학회논문지
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• 제13권4호
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• pp.230-236
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• 2018

3D depth perception has played an important role in robotics, and many sensory methods have also proposed for it. As a photodetector for 3D sensing, single photon avalanche diode (SPAD) is suggested due to sensitivity and accuracy. We have researched for applying a SPAD chip in our fusion system of time-of-fight (ToF) sensor and stereo camera. Our goal is to upsample of SPAD resolution using RGB stereo camera. Currently, we have 64 x 32 resolution SPAD ToF Sensor, even though there are higher resolution depth sensors such as Kinect V2 and Cube-Eye. This may be a weak point of our system, however we exploit this gap using a transition of idea. A convolution neural network (CNN) is designed to upsample our low resolution depth map using the data of the higher resolution depth as label data. Then, the upsampled depth data using CNN and stereo camera depth data are fused using semi-global matching (SGM) algorithm. We proposed simplified fusion method created for the embedded system.

• JSTS:Journal of Semiconductor Technology and Science
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• 제17권3호
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• pp.438-445
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• 2017

This paper presents a low-power high-resolution band-pass ${\Sigma}{\Delta}$ ADC for accelerometer applications. The proposed band-pass ${\Sigma}{\Delta}$ ADC consists of a high-performance 6-th order feed-forward ${\Sigma}{\Delta}$ modulator with 1-bit quantization and a low-power, area-efficient digital filter. The ADC is fabricated in 180 nm 1P6M mixed-signal CMOS process with a die area of $5mm^2$. This high-resolution ADC got 90 dB peak signal to noise plus distortion ratio (SNDR) and 96 dB dynamic range (DR) over 4 kHz bandwidth, while the intermediate frequency (IF) is shifting from 100 KHz to 200 KHz. The power dissipation of the chip is 5.6 mW under 1.8 V (digital)/3.3 V (analog) power supply.

• IEIE Transactions on Smart Processing and Computing
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• 제3권1호
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• pp.19-27
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• 2014

Compressive sensing is an emerging sampling technique which enables sampling a signal at a much lower rate than the Nyquist rate. In this paper, we propose a novel framework based on Kronecker compressive sensing that provides multi-resolution image reconstruction capability. By exploiting the relationship of the sensing matrices between low and high resolution images, the proposed method can reconstruct both high and low resolution images from a single measurement vector. Furthermore, post-processing using BM3D improves its recovery performance. The experimental results showed that the proposed scheme provides significant gains over the conventional framework with respect to the objective and subjective qualities.

• 전자공학회논문지
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• 제50권3호
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• pp.113-121
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• 2013

본 논문은 학습 기반의 2D-FIR필터를 이용한 부화소 렌더링 기법을 제안한다. 제안 기법은 크게 학습 단계와 합성 단계로 나뉜다. 학습 단계에서는 충분히 많은 수의 저해상도/고해상도의 영상 블록 쌍들을 이용하여 고해상도/저해상도 블록의 관계에 따른 합성 정보를 계산하고, 그 합성 정보를 담은 소위 사전을 생성한다. 합성 단계에서는 각 입력 영상에 대응하는 후보 블록을 상기 학습된 사전에서 찾는다. 탐색된 사전 내 합성 정보를 이용하여 부화소 레벨의 축소된 블록을 합성함으로써 최종 축소 영상을 얻는다. 한편, 영상 합성 시 디스플레이 장치의 RGB 패턴을 고려한 필터링을 통해 선명도를 향상시킨다. 모의 실험을 통해 제안 기법이 일반적인 영상축소 기법에 비해 흐림 효과, 엘리어싱 등의 화질 열화없이 고화질의 축소 영상을 생성함을 확인하였다.

• Smart Structures and Systems
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• 제30권5호
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• pp.513-520
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• 2022

During the long-time service of a bolt, its preload may suffer slight perturbations or significant reductions. It is a dilemma to monitor preload changes at high resolution and full scale. Approaches for bolt preload monitoring with multi-resolution should be developed. In this paper, a simple and effective multi-resolution bolt preload monitoring approach using ultrasonic guided waves (UGW) is proposed. A linear relationship between the time-of-flight (TOF) variation of multi-reflected waves and preload is derived to theoretically reveal the multi-resolution properties of UGW. The variations of TOF before and after the slight preload perturbations are extracted by using a global evaluation method. Experimental results show that the signal-to-noise ratio (SNR) of the 1^st, 2^nd, and 3^rd-reflected UGWs is larger than 20 dB. The resolution of the 2^nd-reflected UGW is higher than that of the 1^st-reflected UGW and lower than that of the 3^rd-reflected UGW. The ultimate detectable resolutions of bolt preload (DRBP) of the 1^st and 3^th-reflected UGWs are 0.9% and 0.5%, respectively. By using the 1^st and 3^th-reflected guided waves, the bolt looseness with different degrees can be monitored simultaneously.

• 한국환경과학회지
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• 제28권11호
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• pp.1047-1059
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• 2019

To address the increase of weather hazards and the emergence of new types of such hazards, an optimization technique for three-dimensional (3D) representation of meteorological facts and atmospheric information was examined in this study as a novel method for weather analysis. The proposed system is termed as "meteorological and air quality information visualization engine" (MAIVE), and it can support several file formats and can implement high-resolution 3D terrain by employing a 30 m resolution digital elevation model. In this study, latest 3D representation techniques such as wind vector fields, contour maps, stream vector, stream line flow along the wind field and 3D volume rendering were applied. Implementation of the examples demonstrates that the results of numerical modeling are well reflected, and new representation techniques can facilitate the observation of meteorological factors and atmospheric information from different perspectives.

• 전자공학회논문지D
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• 제35D권8호
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• pp.76-81
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• 1998

This paper presents a new method to synthesize a digital hologram that meets the resolution of a currently manufactured LCD while capable of displaying a 3-D object. That is accomplished by segmenting a hologram, resulting in relaxed sampling constraint. We show that the segmentation of a hologram enables us to utilize the planewave approximation and, unlike in a holographic stereogram, it does not require projection process, but directly takes fourier transform of horizontally sliced 2-D images that constitute a 3-D object, which makes it possible to reconstruct a higher resolution image with depth information. We also show that proposed hologram contains data significantly smaller than the conventional hologram does, which is quite useful for constructing wide-viewing hologram. Finally, simulation results obtained by both methods are compared.

• 한국정보통신학회논문지
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• 제13권1호
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• pp.121-126
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• 2009

평면기반 컴퓨터 집적 영상 복원 (CIIR)기술은 3D 물체에 대한 깊이 영상복원이 가능한 기술이다. 그러나 복원되는 깊이에 따라 영상에 잡음이 발생하게 되어 해상도를 저하시키는 문제점이 있다. 본 논문에서는 이 문제점을 극복하기 위해서 CIIR 기술에 대한 신호 모델을 설명하고, 이를 통하여 CIIR 기술에 발생하는 잡음과 이를 보정하는 방법을 소개한다. 컴퓨터적 실험을 통하여 2D Gaussian 영상의 복원 영상에 대한 잡음 특성을 조사하고, 보정 과정을 통하여 고해상도의 영상을 얻을 수 있음을 보였다.

• JSTS:Journal of Semiconductor Technology and Science
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• 제13권3호
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• pp.198-206
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• 2013

This paper presents a wide band, fine-resolution digitally controlled oscillator (DCO) with an on-chip 3-D solenoid inductor using the 0.13 ${\mu}m$ digital CMOS process. The on-chip solenoid inductor is vertically constructed by using Metal and Via layers with a horizontal scalability. Compared to a spiral inductor, it has the advantage of occupying a small area and this is due to its 3-D structure. To control the frequency of the DCO, active capacitor and active inductor are tuned digitally. To cover the wide tuning range, a three-step coarse tuning scheme is used. In addition, the DCO gain needs to be calibrated digitally to compensate for gain variations. The DCO with solenoid inductor is fabricated in 0.13 ${\mu}m$ process and the die area of the solenoid inductor is 0.013 $mm^2$. The DCO tuning range is about 54 % at 4.1 GHz, and the power consumption is 6.6 mW from a 1.2 V supply voltage. An effective frequency resolution is 0.14 kHz. The measured phase noise of the DCO output at 5.195 GHz is -110.61 dBc/Hz at 1 MHz offset.