• Title/Summary/Keyword: straight line

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구순구개열 환자에 있어 직선봉합법의 역할 (Revisited Straight Line Technique for Unilateral Cleft Lip)

  • 서병무
    • 대한구순구개열학회지
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    • 제11권1호
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    • pp.31-36
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    • 2008
  • The variations of cleft lip deformities imposed the difficulty to the surgical correction for them. Straight line technique for cleft lip surgery has been ignored quite long since other techniques were developed. Initially the straight line technique was introduced and widely accepted because it is simple and easy to perform during the period of no adequate anesthetics. But it was abandoned for its several shortcomings such as tighten lip, vermilion notching, anatomical distortion, and wound contractures. Recently, some groups advocated the usefulness of straight line technique which has a significant modification from its original form. Additionally the variable degree of cleft lip deformity allows simple straight line closure for those patients. Here a case of simple straight line technique was presented and discussed for its reliability and plausible results as well.

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구조해석에 의한 디지털 곡선의 분리 (Segmentation of Digital Curves by Structural Analysis)

  • 류승필;권오석;김태균
    • 대한전자공학회논문지
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    • 제26권12호
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    • pp.1984-1994
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    • 1989
  • Techniques for approximating digitalcurves by polygonal lines are a valuable tool for image analysis and data compression. S. Shilien proposed a method for segmenting a digital curve into digital straight line segments digital straight line segments which are not satisfied with the structural properties, and have more than one break point by Shilien's method. Here, the structural representation of digital straight lines and digital staight line segments is described. And a method for segmenting a digital curve into digital straight line segments which are not satisfied with the structural properties, and have more than one break point by Shilien's method. Here, the structural representation of digital straight lines and digital staight line segments is described. And a method for segmenting a digital curve into digital straight line segments which may be not satisfied with the structural properties is proposed. The number of break points extracted by this method is less than that by S. Shilien's method from the digital curve which includes the digital straight line segments not satisfied with the structural properties.

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편측성 불완전 구순열의 직선 봉합법에 의한 수복 - 증례 보고 및 문헌고찰 (The Straight Line Repair for Unilateral Incomplete Cleft Lip - Cases report and journal review)

  • 김학균;김재진;김은석
    • 대한구순구개열학회지
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    • 제11권2호
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    • pp.77-82
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    • 2008
  • The harmonious lip length, residual scar and Cupid's bow width and peak with a normal side are the aims of a unilateral cleft lip repair. Also, long term amelioration without necessary of revisional surgeries may be the ideal conditions. No one method can satisfy the wide varieties of cleft lip deformities. Recently with rearrangement of paraoral muscle and some modifications, a straight line repair technique has been concerned again. Straight scar line, simplicity, and short learning curve are the advantages of the straight line technique. Here two cases of the simple straight line technique were presented and discussed for its usefulness and reliability with short reviews of previous reports.

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주성분 분석과 허프 변환을 이용한 직선 검출 (Straight Line Detection Using PCA and Hough Transform)

  • 오정수
    • 한국정보통신학회논문지
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    • 제22권2호
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    • pp.227-232
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    • 2018
  • 직선 검출을 위한 대표적인 알고리즘인 허프 변환에서 잡음이 있거나 복잡한 영상에서 생성되는 방대한 에지 화소들은 상당한 계산량과 의사직선을 야기한다. 본 논문은 기존 허프변환을 개선하기 위해 2 단계 직선 검출 알고리즘을 제안한다. 첫 번째 단계에서 제안된 알고리즘은 영상을 겹치지 않는 블록들로 나누고, 주성분 분석(PCA)을 이용해 블록 내 에지 화소들의 직선과 관련된 정보를 검출한다. 두 번째 단계에서 직선과 관련된 화소들에 기울기 제한된 허프변환을 수행하여 직선들을 검출한다. 모의실험 결과들은 제안된 알고리즘이 부가적인 계산이 다소 필요하지만 불필요한 에지 화소들을 줄이고 기울기 영역을 제한하여 ${\rho}$ 계산의 평균 94.6% 줄여주고 의사직선 검출을 방지하는 것을 보여주고 있다.

에지 화소들의 직선 정보를 이용한 허프변환 (Hough Transform Using Straight Line Information of Edge Pixels)

  • 김진태;오정수
    • 한국정보통신학회:학술대회논문집
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    • 한국정보통신학회 2017년도 추계학술대회
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    • pp.674-677
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    • 2017
  • 허프변환은 에지 화소를 대상으로 직선을 검출하는 가장 대표적인 알고리즘이다. 허프변환은 단순한 직선 영상에서는 우수한 성능을 보이나 잡음이 있거나 복잡한 영상에서는 상당한 계산량을 요구하고 쉽게 의사직선을 검출하는 문제를 갖고 있다. 본 논문은 기존 허프변환의 문제를 개선하기 위한 직선 검출 알고리즘을 제안한다. 제안된 알고리즘은 허프변환을 수행하기 전에 주성분 분석을 이용해 에지 화소의 직선 정보를 검출한다. 에지 화소의 직선 정보를 근거로 유효 에지 화소에서 제한된 기울기 영역의 허프변환을 수행한다. 모의실험 결과들은 제안된 알고리즘이 계산량을 크게 줄이는 것은 물론 의사직선도 제거하는 것을 보여주고 있다.

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코너 출구속도가 직선주로 주행 소요시간에 미치는 영향 (Effect of Corner Exit Speed on the Time to Go Down a Straight)

  • 장성국
    • 한국자동차공학회논문집
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    • 제11권6호
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    • pp.141-146
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    • 2003
  • This paper calculates the elapsed time to go down a straight as a function of the corner exit speed and considers air resistance, rolling resistance, and slope resistance to figure out the force for forward acceleration. In a car racing, the most critical comer in a course is the one before the longest straight. A driver can lose a quite amount of time by taking a bad line in a corner. Taking a bad line also causes poor comer exit speed which in turn costs more elapsed time to go down a straight. The results are not so dramatic as in the case of cornering but are showing why one should take the correct corner racing line to get the maximum exit speed. Also, for the case of drag race, the elapsed time to go 1/4 mile is calculated.

Elementary School Students' Mathematical Metaphors for Line Segments, Straight Lines, and Rays

  • Sangmee Kim
    • 한국수학교육학회지시리즈D:수학교육연구
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    • 제26권4호
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    • pp.271-289
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    • 2023
  • This research investigates the development of elementary students' concepts of line segments, straight lines, and rays, employing metaphor analysis as a research methodology. By analyzing metaphorical expressions, the research aims to explore how elementary students form these geometric concepts line segments, straight lines, and lays and evolve their understanding of them across different grades. Surveys were conducted with elementary school students in grades three to six, focusing on metaphorical expressions and corresponding their reasons associated with line segments, straight lines, and rays. The data were analyzed through coding and categorization to identify the types in students' metaphorical expressions. The analysis of metaphorical expressions identified five types: straightness, infinity or direction, connections of another geometric concepts, shape and symbols, and terminology.

주성분 분석을 이용한 직선 검출에 대한 분석 (Analysis of Straight Line Detection Using PCA)

  • 오정수
    • 한국정보통신학회논문지
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    • 제19권9호
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    • pp.2161-2166
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    • 2015
  • 본 논문은 주성분 분석을 이용한 직선 검출 알고리즘을 분석하여 새로운 두 기능이 추가된 개선된 알고리즘을 제안한다. 첫 번째 기능은 검출된 직선을 통해 무효 화소를 제거하고 다시 직선을 검출하는 것이고, 두 번째 기능은 겹치지 않는 블록들에서 직선 검출을 통해 후보 직선들 선택하고, 각 후보 직선의 주변 화소들을 이용해 유효 직선을 검출하는 것이다. 제안된 알고리즘은 정제된 직선 영상에서는 기존 알고리즘보다 적은 계산량으로 더 정확한 직선을 검출하고 있다.

비대칭성이 고려된 나선형 시험 모델을 통한 손상 수상함의 직진 안정성 추정 (Estimation of Straight Line Stability of a Damaged Surface Combatant through Spiral Maneuver Test Model Considering Asymmetry)

  • 하정수;정연환
    • 시스템엔지니어링학술지
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    • 제16권2호
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    • pp.110-117
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    • 2020
  • In this paper, we estimated the straight line stability by performing a 3 degree of freedom spiral test simulation of a intact/damaged surface combatant using the hydrodynamic coefficient obtained through the PMM(Planar motion mechanism) test based on system engineering process. A model ship was ONR Tumblehome and damaged compartment was set on the starboard bow. As a result of conducting a spiral test simulation based on the experimental results of J.Ha (2018), the asymmetric straight line stability due to the damaged compartment was confirmed. In the case of a ship in which the starboard bow was damaged, it was confirmed that it had the characteristic to deflect to the left when going straight. Also, when estimating the straight line stability of a both port and starboard asymmetric surface combatant, a separated equation of motion model that sees the port and starboard as different ships seems suitable.

Shallow ground treatment by a combined air booster and straight-line vacuum preloading method: A case study

  • Feng, Shuangxi;Lei, Huayang;Ding, Xiaodong;Zheng, Gang;Jin, Yawei
    • Geomechanics and Engineering
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    • 제24권2호
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    • pp.129-141
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    • 2021
  • The vacuum preloading method has been used in many countries for soil improvement and land reclamation. However, the treatment time is long and the improvement effect is poor for the straight-line vacuum preloading method. To alleviate such problems, a novel combined air booster and straight-line vacuum preloading method for shallow ground treatment is proposed in this study. Two types of traditional vacuum preloading and combined air booster and straight-line vacuum preloading tests were conducted and monitored in the field. In both tests, the depth of prefabricated vertical drains (PVDs) is 4.5m, the distance between PVDs is 0.8m, and the vacuum preloading time is 60 days. The prominent difference between the two methods is when the preloading time is 45 days, the injection pressure of 250 kPa is adopted for combined air booster and straight-line vacuum preloading test to inject air into the ground. Based on the monitoring data, this paper systematically studied the mechanical parameters, hydraulic conductivity, pore water pressure, settlement and subsoil bearing capacity, as determined by the vane shear strength, to demonstrate that the air-pressurizing system can improve the consolidation. The consolidation time decreased by 15 days, the pore water pressure decreased to 60.49%, and the settlement and vane shear strengths increased by 45.31% and 6.29%, respectively, at the surface. These results demonstrate the validity of the combined air booster and straight-line vacuum preloading method. Compared with the traditional vacuum preloading, the combined air booster and straight-line vacuum preloading method has better reinforcement effect. In addition, an estimation method for evaluating the average degree of consolidation and an empirical formula for evaluating the subsoil bearing capacity are proposed to assist in engineering decision making.