Hough Transform을 이용한 일부 파손된 영상복원 알고리즘 구현

유봉길,정종필 順天靑巖大學 1995 論文集-順天靑巖大學 Vol.19 No.-

This paper presents a method of restore lines and ellipses from the image by using Hough transform. For ellipse restoration parameters of the ellipse are restored by Least Square Method using particular points that contain geometric properties of the ellipse, instead of accumulating Hough array. Lines and ellipses are restoration, lines are first restored by conventional Hough transform, then the data of lines are eliminated to reduce the calculation cost and also to ease restoration of ellipses.

음원 방향각 추정에 관한 계산기 시뮬레이션

이채봉,김정국,김길중 東西大學校 1998 동서논문집 Vol.4 No.-

In this paper describes the optimum beamforming algorithm when it estimates source signal localization. It is proposed many methods for the identification of a sound source localization. But in this study, compares and ivestigates the angle resolution and sharp peak value by the simulation. The simulation perform to each of DSA(Delay Sum Arry), MV(Minimum Variance), MUSIC(MUltiple SIgnal Classification) method when signals with two or three frequency exist. In result, the MUSIC method has excellent angle resolution and sharp peak value in estimating the derection of arrival signals at each microphone for arbitrary direction of the sound source singnal.

확대 영상의 해상도 향상에 관한 연구

강길봉,김장형,김정효 제주대학교 공과대학 첨단기술연구소 2004 尖端技術硏究所論文集 Vol.15 No.1

Generally, the still image magnification uses image growing, interpolation and restoration in order to get magnificated image. Still image Magnification does not get high-resolution image because, amount of information is not sufficient. In this thesis, we proposed the hybrid method of high resolution image magnification. that is, to get high resolution image, the image processed by both lowpass filtering and highboost filtering. Result of apply proposed method to Lena image, we gained result of enhancement more better than formerly simple technique.

교량 바닥판 보수공사에서 발생하는 콘크리트 폐수처리 방안

이봉학,최판길,김정기 江原大學校 産業技術硏究所 2008 産業技術硏究 Vol.28 No.A

As of 2003, construction waste has been produced at the level of 130,614.8 tons/day, in which the amount of waste concrete was 92,639.1 tons/day and accounted for about 66.4% of the amount of construction waste. Waste concrete is mainly produced in construction work and civil engineering work. Especially, road surface crushing method using a large amount of water requires thorough management of concrete wastewater. The aim of this study was to analyze water pollution due to concrete wastewater generated in repair of bridge deck using road surface crushing equipment and to suggest reasonable countermeasures for solve the problem. In this study, it was surveyed current conditions of produced concrete wastewater in bridge deck repair, analyzed physical features of concrete wastewater, expected effects of water pollution on inflow rivers if it is not treated, established treatment plan of water pollution by categories, and calculated capacity of each treatment process and required amount of necessary chemicals. As a result of sampling wastewater generated in field sites and testing it at a lab scale, it was revealed that the original wastewater was produced in removing concrete from bridge deck slabs using surface crushing equipment whose pH was 12.53, CODMn was 12.910mg/L, SS was 547.0mg/L, and other heavy metals were included in extremely small quantities.

國稅의 優先權에 관한 硏究

崔鳳吉 건국대학교 행정대학원 1989 建國大學校 行政大學院 硏究論叢 Vol.17 No.-

현장실험을 통한 VES-LMC 균열발생 원인분석

최판길,이봉학 강원대학교 산업기술연구소 2006 産業技術硏究 Vol.26 No.B

Many concrete bridge decks develop transverse cracking shortly after construction. These cracks accelerate corrosion of reinforcing steel and lead to concrete deterioration, damage to components beneath the deck, unsightly appearance. These cracks shorten the service life and increase maintenance costs of bridge structures. In this study, VES-LMC overlay, which provides the same benefits as a conventional overlay, is designed to cure very quickly. Although the materials for VES overlays are more expensive, the cost is more than offset by the savings on traffic control and work zone safety measures. Otherwise, reaction of hydration occurs very rapidly in beginning step(concrete placing). As a results, thermal cracking can be occur by thermal stress in accordance with hydration-heat The purpose of this study was to estimate diagnosis of crack occurrence of VES-LMC through field tests at early-age.

경계 영역 검출을 이용한 이미지데이터 압축에 관한 연구

유봉길 順天靑巖大學 1999 論文集-順天靑巖大學 Vol.23 No.-

In this papers, we proposes a efficient compression method of an image using the extraction of boundary region of DCT in MPEG-1. DCT coefficients have from low frequency to high frequency various components. After performing DCT to an image, the data is compressed to contain the boundary Region by quantization, and the information of boundary Region can be extracted by inverse DCT. In those, I chose frequency components susceptible to the boundary through the many experiences. In this paper, boundary can be selected by dividing low frequency by big quantization coefficient and dividing high frequency by small quantization coefficient without degrading visual quality in MPEG-1. Also it is predicted that to reduce high frequency value will be good in noisy environments.

배관결함 검출을 위한 자왜형 초음파 센서의 특성

안봉영,김영주,김영길,이승석 한국비파괴검사학회 2000 한국비파괴검사학회지 Vol.20 No.1

석유화학 설비 등과 같은 노출 배관의 결함을 검출하는데 효율적으로 이용될 수 있는 자왜형 초음파 센서를 제작하였다. 최대의 초음파 발생 효율을 얻기 위한 최적 조건을 설정하였으며, 실험에 사용된 배관의 경우 250~350Oe의 정자기장이 최적이었으며, 180kHz의 주파수를 갖는 초음파를 발생시키기 위해서는 15mm 폭의 코일을 사용하는 것이 가장 좋았다. 최적의 조건에서 발생된 초음파는 50m 이상을 충분히 진행할 수 있으며, 결함의 단면적이 증가함에 따라 수신된 결함 신호는 직선적으로 증가함을 확인하였다. Magnetostrictive sensors which can be used effectively to detect flaws in pipe were fabricated. The optimal conditions to obtain the maximum generation efficiency of the ultrasonic wave were established. In case of the used steel pipe the optimal magnetic field was 250~350Oe and the coil width of 15mm showed the best efficiency for generating a wave with the frequency of 180 kHz. In the best condition, the wave can propagate further than 50m without serious attenuation. The amplitude of the ultrasonic wave reflected from artificial flaw had a good linear relationship to the cross-sectional area of the flaw.

VES-LMC의 열 특성을 고려한 자기수축

최판길,이봉학 강원대학교 산업기술연구소 2005 産業技術硏究 Vol.25 No.B

Durability of concrete structures is seriously compromised by cracking at early-age concrete, particularly in high-strength or high-performance concrete structures. Since early-age cracking is influenced by various factors that affect the hydration process, early-age shrinkage and stress/strain development, the behavior at early-age is highly complex and no rational methodologies for its control have yet been established. Concrete structures often present volumetrical changes particularly due to thermal and moisture related shrinkages. Volumetric instability is detrimental to the performance and durability of concrete structures because structural elements are usually restrained. These restrained shrinkages develop tensile stresses which often results in cracking in combination with the low fracture resistance of concrete. Early-age defects in high-performance concrete due to thermal and autogenous deformation shorten the life cycle of concrete structures. Thus, it is necessary to examine the behavior of early-age concrete at the stages of design and construction. The purpose of this study was to propose a shrinkage models of VES-LMC (very-early strength latex-modified concrete) at early-age considering thermal deformation and autogenous shrinkage.

구조적 분석과 DP정합 방법에 의한 한글인식에 관한 연구

유봉길,문창수 順天靑巖大學 1994 論文集-順天靑巖大學 Vol.18 No.-

In this paper, an on-line recognition system for hand-written Korean characters using Structure Analysis and DP Matching Method was implemented. Korean "Hangul" consists of a phonetic alphabet containing consonants and vowels. The consonants were divided into two groups: the standard fourteen simple consonants and five double consonants. Similarly, eleven double vowels have been added to the standard ten simple vowels. These forty make up the basic letters of the Korean alphabet for the purpose of this research. The proposed algorithm, invariant to size and distance, reduces greatly the computational requirement of dynamic programming by matching phonemes rather than character patterns. where the angle difference and the ratio of lengths between input and reference patterns are adopted as matching features. it converts the mouse input into character vector composed of stroke type and relative start position.