• Journal of the Institute of Electronics Engineers of Korea SD
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• v.43 no.1 s.343
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• pp.59-64
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• 2006

The slope of the ramp generator in a single slope ADC(analog-to-digital converter) suffers from process and frequency variation. This variation in ramp slope causes ADC gain variation and eventually limits the performance of the ISP(image signal processing) in a CIS(CMOS image sensor) that uses the single slope ADC. This paper proposes a ramp slope BISC(built-in-self-calibration) scheme for CIS. The CIS with proposed BISC was fabricated with a $0.35{\mu}m$ process. The measurement results show that the proposed architecture effectively calibrate the ramp slope against process and clock frequency variation. The silicon area overhead is less than $0.7\%$ of the full chip area.

• Proceedings of the Korea Multimedia Society Conference
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• 2004.05a
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• pp.802-805
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• 2004

표준 단일모드 광섬유를 전송선으로 사용하고, Raman 중폭기 없이 EDFA 증폭기 만을 사용하여, 각 채 널당 10Gb/s 의 파장다중화된 40 개 채널신호들을 3,000km 전송하는 경제적인 광 링크를 구성 한 뒤, 이 링크의 전송 성능 최적화를 위해 분산 맵 구조의 차이 에 따른 성능 차이를 분석하였다. 이 링크의 분산 맵은 전치분산보상, 구간분산보상 그리고 후치분산보상으로 나누어 지는데 이 들의 다양한 조합을 통해 15 가지의 다양한 분산 맵들을 구성한 뒤 각각의 경우를 분석하여 링크 성능을 크게 향상시키는 최적화된 분산맵 구조를 구하였다. 이 최적화된 분산 조건이, 단일 모드 광섬유와 분산보상 광섬유가 가지 는 파장에 따른 분산 기울기의 불일치로 인해 받게 되는 영향이 조사되었고 이 영향이 링크의 성능에 미치는 효과가 무시될 수 있는 분산 기울기의 허용 가능한불일치 범위를 구하였다.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.30 no.1A
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• pp.1-9
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• 2005

We have studied the dispersion properties of a 40 channel x 10 Gbit/s wavelength division multiplexer(WDM) transmission link using standard single mode fiber with all EDFA amplification over 30 x 100 km spans. The dispersion map of the link was investigated by adding fiber sections with positive or negative dispersion at the transmitter, within each amplifier span, and at the receiver. Optimum combinations of these dispersive fiber lengths were attained to significantly enhance the overall transmission performance.

• The Korean Journal of Applied Statistics
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• v.26 no.6
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• pp.1009-1018
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• 2013

Regression analysis is useful to understand the relationship of variables; however, we need to test if the slope of each regression lines is the same when comparing several populations. This paper suggests a new parallelism test for several linear regression lines. We use F-test of ANOVA and Kruskal-Wallis (1952) tests after obtaining slope estimator from a sequential slope. In addition, a Monte Carlo simulation study is adapted to compare the power of the proposed methods with those of Park and Kim (2009).

• The Journal of Korean Academy of Prosthodontics
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• v.37 no.5
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• pp.581-596
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• 1999

The purpose of this study was to investigate the stress distribution of the abutment and sup-porting tissues according to the slopes and types of the guiding plane of distal extension removable partial dentures. The 3-dimensional finite element method was used and the finite element models were prepared as follows. Model I : Kratochvil type guiding plane with $90^{\circ}$ to residual ridge Model II : Kratochvil type guiding plane with $95^{\circ}$ to residual ridge Model III : Kratochvil type guiding plane with $100^{\circ}$ to residual ridge Model IV : Krol type guiding plane with $90^{\circ}$ to residual ridge Distal extension partial denture which right mandibular first and second molar were lost was used and the second premolar was prepared as primary abutment with RPI type retainer. Then 150N of compressive force was applied to central fossae of the first and second molars and von Mises stress and displacement were measured. The results were as follows 1. Model I and Model IV showed a similar stress distribution pattern and the stress was concentrated on the apex of the root of the abutment. 2. The stress was increased and concentrated on mesial side of the root of the abutment in Model II. The stress was concentrated on buccal and mesiobuccal side of the root of the abutment in Model IV. 3. In Model I, the root of the abutment displaced and twisted a little in clockwise. In Model IV, the root of the abutment displaced to distolingually at apical region of the root and mesiobuccally at cervical region of the root. 4. In Model II, the root of the abutment displaced to mesiolingually at apical region of the root and more displaced and twisted in counterclockwise at cervical region of the root. In Model III, the root of the abutment displaced to mesiobucally at apical region of the root and more displaced and twisted in clockwise at cervical region of the root.

• Proceedings of the Korea Information Processing Society Conference
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• 2013.05a
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• pp.367-370
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• 2013

단일 영상에서 3차원 정보를 획득하기 위해 가장 많이 사용되는 단서로는 소실점이 있다. 본 논문에서는 소실점을 추정하기 위해서 허프변환을 사용하여, 단일 영상의 소실점 탐색 시 유효 직선간의 기울기 값 비교 및 근접도를 구하여 교점 생성에 필요 없는 정보를 제거함으로서 소실점 추정 정확도를 높인 보다 정확한 소실점 탐색 기법을 제안하였다.

• Journal of the Korean Society of Marine Environment & Safety
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• v.22 no.6
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• pp.750-757
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• 2016

This study presents the wave run-up height around single and multiple surface-piercing cylinders according to wave period and steepness. In order to simulate 3D incompressible viscous two-phase turbulent flow, the present study employed a volume of fluid (VOF) method with realizable $k-{\varepsilon}$ turbulence model based on commercial Computational Fluid Dynamics (CFD) software, "STAR-CCM". The wave periods at model scale were 1.269s and 1.692s for a single cylinder and 1.716s for multiple cylinders. In each case, wave steepness of has 1/30 and 1/16 were used, respectively. Consequently, the results for wave run-up height with regard to wave steepness and period were compared with those of relevant previous experimental studies. The numerical simulation results showed a good qualitative agreement with experiments.

• Journal of the Korea Society of Computer and Information
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• v.16 no.8
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• pp.57-66
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• 2011

In this paper, it is proposed for algorithm to detect human efficiently using a edge symmetry and gradient directional characteristics in realtime by the feature extraction in a single input image. Proposed algorithm is composed of three stages, preprocessing, region partition of human candidates, verification of candidate regions. Here, preprocessing stage is strong the image regardless of the intensity and brightness of surrounding environment, also detects a contour with characteristics of human as considering the shape features size and the condition of human for characteristic of human. And stage for region partition of human candidates has separated the region with edge symmetry for human and size in the detected contour, also divided 1st candidates region with applying the adaboost algorithm. Finally, the candidate region verification stage makes excellent the performance for the false detection by verifying the candidate region using feature vector of a gradient for divided local area and classifier. The results of the simulations, which is applying the proposed algorithm, the processing speed of the proposed algorithms is improved approximately 1.7 times, also, the FNR(False Negative Rate) is confirmed to be better 3% than the conventional algorithm which is a single structure algorithm.

• Journal of KIISE:Software and Applications
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• v.33 no.1
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• pp.84-94
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• 2006

The color information in an image changes as the illuminant condition varies. The mechanism to find canonical color of an object by estimating illumination color in an image is generally referred as color constancy. In color constancy, computing robust and precise dichromatic line is most important to estimate illumination chromaticity. In this paper, a novel approach to estimate the color of a single illuminant for noisy and micro-textured images is introduced. An accurate dichromatic line is found by using Dichromatic Line Space (DLS), proposed in this paper. which has information about diffuse chromaticity and illumination chromaticity.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.16 no.7
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• pp.1487-1494
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• 2012

This paper proposes an algorithm detecting the skew of the degraded as well as the clear document images using edge and correcting it. The proposed algorithm detects edges in a character region selected by image complexity and generates projection histograms by projecting them to various directions. And then it detects the document skew by estimating the edge concentrations in the histograms and corrects the skewed document image. For the fast skew detection, the proposed algorithm uses downsampling and 3 step coarse-to-fine searching. In the skew detection of the clear and the degraded images, the maximum and the average detection errors in the proposed algorithm are about 50% of one in a conventional similar algorithm and the processing time is reduced to about 25%. In the non-uniform luminance images acquired by a mobile device, the conventional algorithm can't detect skews since it can't get valid binary images, while the proposed algorithm detect them with the average detection error of 0.1o or under.