• 제목/요약/키워드: length measuring

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음향 이방성을 고려한 티타늄 용접부의 결함길이 측정에 관한 연구 (A Study on the Defect length Measurement of Titanium Weld Zone Considering Acoustical Anisotropy)

  • 박희동;윤인식;이원
    • 한국정밀공학회지
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    • 제28권9호
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    • pp.1070-1077
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    • 2011
  • This study intends to assess the defect in the weld zone of titanium grade 2 plate in terms of acoustical anisotropy based on the angle beam method. Depending on the rolling direction, the ratio of wave velocity was found to be 1.08 and the difference in the angle of refraction was more than seven degrees, confirming the presence of acoustical anisotropy. Thus for measuring the length of defect in the weld zone of the titanium plate (thickness of 10mm), the distance amplitude characteristics curves of titanium, TDACC-R and TDACC-T were constructed for the measurements in consideration of the acoustical anisotropy on CRT of the ultrasonic testing equipment. As a result, when the distance amplitude characteristics curve corresponds to the rolling direction, the length of defect was close to the actual measurement within 1mm and when different, the difference was found to be over 4mm. It was affirmed that the acoustical anisotropy should be taken into consideration when measuring the length of defects in the weld zone of the titanium plate with the presence of acoustical anisotropy.

무인항공기를 활용한 가설구조물의 길이와 기울기 측정에 관한 연구 (A Study on Measurement of Length and Slope of Temporary Structure using UAV)

  • 강민국;신승현;박종근;원정훈
    • 한국안전학회지
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    • 제37권6호
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    • pp.89-95
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    • 2022
  • A method for measuring the length and slope of a temporary structure using an unmanned aerial vehicle (UAV) and 3D modeling method is proposed. The actual length and slope of the vertical member of the specimen were measured and compared with the measured values obtained by the proposed method for the specimens with and without the vertical protection net installed. Based on the result of measuring the length of the temporary structure specimen using the UAV and 3D modeling method, the measured value showed an error of 0.87% when compared to the actual length in the specimen without the vertical protection net installed. In addition, the error of the slope was 0.63°. It was thought that the proposed method could be usable for the purpose of finding parts in wrong installation state on the temporary structure and informing the manager in charge. However, in the case of the specimen with the vertical protection net, the measurement showed a 1.46% error in length and 2.77° difference in slope. Therefore, if a vertical protection net is to be installed in a temporary structure, the measurement accuracy should be improved by utilizing an image processing method, etc.

피로균열 성장과정에 대한 평가방법의 영향 (Influence of Evaluation Methods for Fatigue Crack Growth Process)

  • 안철봉
    • 한국생산제조학회지
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    • 제8권1호
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    • pp.119-125
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    • 1999
  • The distribution of fatigue crack growth rate is subjected to the measuring interval and calculated method of growth rate. In this paper, in order to establish the method of determining the distribution of fatigue crack growth rate, which ignores those influences, a series of fatigue crack growth experiments and measuring intervals of crack length calculated reasonable are presented. The main conclusions obtained are summarized as follows: 1) As a result of the ΔP constant test and ΔK constant test, it is thought that an approximate measuring interval of 0.3~0.7mm is reasonable, which allows for few errors and is little subjected to the calculated method of crack growth rate. 2) After generally comparing the error estimation by using the experimental data of CCT specimen with the error rating of the CT specimens, it is possible that the fatigue test has few errors within the measuring interval, ξ(Δa/W)=0.0067~0.017, regardless of the dimension of specimen geometry.

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다결정 실리콘 박막 트랜지스터의 성능에 대한 채널 길이의 영향 (Influence of Channel Length on the Performance of Poly-Si Thin-Film Transistors)

  • 이정석;장창덕;백도현;이용재
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 1999년도 춘계학술대회 논문집
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    • pp.450-453
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    • 1999
  • In this paper, The relationship between device performance and channel length(1.5-50$\mu$m) in polysilicon thin-film transistors fabricated by SPC technology was Investigated by measuring electric Properties such as 1-V characteristics, field effect mobility, threshold voltage, subthreshold swing, and trap density in grain boundary with channel length. The drain current at ON-state increases with decreasing channel length due to increase of the drain field, while OFF-state current (leakage current) is independent of channel length. The field effect mobility decrease with channel length due to decreasing carrier life time by the avalanche injection of the carrier at high drain field. The threshold voltage and subthreshold swing decrease with channel length, and then increase in 1.5 $\mu$m increase of increase of trap density in grain boundary by impact ionization.

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초음파로 신장의 크기 측정 시 미치는 영향에 관한 연구 (A Study of Factors Affecting Measurement of Kidney Size in Ultrasonography)

  • 윤석환;김연민;최준구
    • 대한방사선기술학회지:방사선기술과학
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    • 제31권2호
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    • pp.161-169
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    • 2008
  • 초음파 검사로 신장의 크기를 측정하는 일은 신 질환의 진단, 치료, 예후 예측에서 중요한 지표가 되므로, 이에 대한 정확한 계측 및 평가는 임상적으로 매우 중요하다. 이에 신장 크기 측정 시 영향을 미치는 요인들을 나열하여, 신장크기 측정의 재현성과 객관성을 높여 보고자 하였다. $21{\sim}27$세의 대한민국 성인 44명을 대상으로 하였다. 8시간 이상 금식한 상태에서 피검자의 자세(position)와 프로브(probe)의 접근방향을 변화시키면서 양측 신장이 가장 크게 보이도록 측정하였다. 이후 물 $700{\sim}1,000\;cc$를 섭취하고 30분과 1시간 후에 같은 방법으로 각각 측정하여 신장크기를 비교하였다. 옆으로 누운 자세(lateral down decubitus)에서 측면주사(lateral approach scan) 시 좌, 우측 모두 신장의 평균길이가 가장 크게 측정되었으며, 측정 시 편차도 가장 크게 나타났다. 금식상태에서 우측 신장의 평균길이는 10.19 cm, 좌측 신장의 길이는 10.33 cm이었다. 수분 섭취 후 60분에서 우측 신장의 평균길이는 10.94 cm, 좌측 신장의 길이는 11.13 cm이었다. 금식 상태에서의 신장 평균길이와 수분섭취 후 60분에 길이를 비교하면, 우측신장의 길이는 7.3%, 좌측 7.7%로 크기가 증가하여 통계적으로 유의하게 나타났다(P < 0.003). 초음파를 이용한 신장의 크기측정은 환자의 수분 섭취상태와 프로브의 접근 방향, 그리고 환자의 자세에 따라 달리 측정될 수 있다. 임상적으로 신장크기 측정이 특히 중요할 때는 수분의 섭취량과 섭취시간을 고려해야 하며, 환자의 자세와 프로브 접근방향을 기록-보관하여, 환자 추적 검사 시 이를 적용하는 것이 신장 길이 측정의 재현성을 높이는 방법이라 사료된다.

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전치장경에 관한 X-선학적 연구 (ROENTGENOLOGIC INVESTIGATIONS FOR THE ANTERIOR TOOTH LENGTH)

  • 조원표
    • 치과방사선
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    • 제2권1호
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    • pp.53-57
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    • 1972
  • The author measured the length of crown, root and tooth on the films which was taken by intraoral bisecting technic with mesh plate on the films. The films were taken from the dry skulls, dentiform and patients who had to be removed their upper incisors and the other patients who adimitted for dental care. From this serial experiment the results was made as follows: 1. By using the film and mesh plate in the oral cavity, the real tooth length can be measured easily on the film surfaces. 2. It can be avoided the film distortion in the oral cavity when taking the film using the mesh plate and film together. 3. When measuring the film, length of crown was elongated and length of root was shortened. 4. When using the well-trained bisecting technic, the real tooth length can be measured directly on the intraoral film.

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발계측 자료에 기초한 신골 할출 시스템의 검증에 관한 연구 (A Study on Verification of Shoe Last Grading System Based on Foot Measuring Data)

  • 박해수
    • 대한인간공학회지
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    • 제26권1호
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    • pp.71-77
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    • 2007
  • Shoe's size and shape are determined by the last that takes shape of foot because last is the mold of shoe in development and manufacturing process. Then adaptation between foot and shoe is dependent on the last. In mass shoe production, model size is developed in the first place, other sized lasts are made through the grading process based on model size. The most important factor in grading system is grading deviation that must be same amount induced from foot measuring database. At present, most of the last manufacturing companies in korea using 260mm as a standard foot model size. When length grading deviation is 5mm, the ball girth grading deviation is 3.7mm and the ball width grading deviation is 1.2mm. I verified existing grading system by comparing grading results with foot measuring data. Also, I proposed reasonable grading deviation and application method of grading system. From the analysis of foot measuring database, reasonable grading deviations are 1.22mm in ball width and 0.84mm in ankle height in case of length grading deviation is 5mm. I confirmed that the current grading system is very accurate. When we grade last from 230mm to 290mm by current grading system based on model size 260mm, there is grading error over 1mm in the front outside area of foot. This error level of 1mm is no problem in normal walking shoe's last, but it induces adaptation problems in sports and special purposed shoe's last. Therefore using of three standard model size is recommended in grading men's last for reducing grading deviation error under the level of 1mm. It is specifically described as 235mm in 225-245mm, 260mm in 250-270mm, 285mm in 275-295mm. According to the above recommended grading system, it is enough to measure only three foot sizes in case of foot measuring project for men's last development.

분기배관의 압력강하에 관한 연구 (A Study on the Pressure Drops of T-Branch Pipes)

  • 남준석;백창선;권순관;김동현;민경탁;김병곤;이성호
    • 한국화재소방학회논문지
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    • 제22권3호
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    • pp.272-277
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    • 2008
  • 본 연구는 분기배관을 물계통 소화설비에 적용할 경우 정확한 등가길이를 제시하고자 수행하였다. 등가길이 측정위치를 예측하고자 분기배관의 압력강하에 대해 유한체적법을 이용하여 확인한 후 측정위치를 결정하였고 그 위치에서 압력손실시험을 실시하였다. 측정된 값의 정확성을 판단하기 위해 해석결과와 비교하였고 두 값이 유사함을 알 수 있었다. 본 연구의 결과로 분기배관의 압력손실측정위치를 주방향의 입구측은 주배관 호칭의 20배, 출구측은 주배관 호칭의 10배, 분기방향의 출구측은 주배관 호칭의 20배로 제안하였다.

QSCC II 체질과 두면부 계측항목의 연관성 분석 (Analysis of the Relationship between Sasang Constitution and Measuring Items of the Head and Face)

  • 박수진;양재하;김광중;권영규
    • 동의생리병리학회지
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    • 제21권1호
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    • pp.270-280
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    • 2007
  • The objectives of study are to investigate the relationship between Sasang Constitution(四象醫學) and measuring items of the head and face and to develop useful diagnosis standard of Sasang Constitution. Subjects took QSCCII(Questionnaire for the Sasang Constitution Classification II) tests repeatedly at an interval of one year and were diagnosed as same constitutions. The 9 Items were measured by Martin-type anthropometric method in 112 subjects. Compared with measurements of 3 constitutions, the mean values in Taeeum-in(太陰人) showed highest and there were significant differences in 7 items between Taeeum-in(太陰人) and other constitutions. Especially, Measurements of Bitragus to Submandibular Arc Length(BSAL) item and Bitragus to Menton Arc Length(BMAL) item showed significant differences between Taeeum-in(太陰人) male and other constitutions male. It seems that BSAL and BMA items can differentiate Taeeum-in(太陰人) from other constitutions and these items have possibility to be a diagnosis standard of Sasang Constitution.