• Title/Summary/Keyword: length measuring

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

  • Park, Hee-Dong;Yun, In-Sik;Yi, Won
    • Journal of the Korean Society for Precision Engineering
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    • v.28 no.9
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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.

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

  • Min-Guk, Kang;Seung-Hyeon, Shin;JongKeun, Park;Jeong-Hun, Won
    • Journal of the Korean Society of Safety
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    • v.37 no.6
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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.

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

  • 안철봉
    • Journal of the Korean Society of Manufacturing Technology Engineers
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    • v.8 no.1
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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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Influence of Channel Length on the Performance of Poly-Si Thin-Film Transistors (다결정 실리콘 박막 트랜지스터의 성능에 대한 채널 길이의 영향)

  • 이정석;장창덕;백도현;이용재
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 1999.05a
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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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A Study of Factors Affecting Measurement of Kidney Size in Ultrasonography (초음파로 신장의 크기 측정 시 미치는 영향에 관한 연구)

  • Yoon, Seok-Hwan;Kim, Yun-Min;Choi, Jun-Gu
    • Journal of radiological science and technology
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    • v.31 no.2
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    • pp.161-169
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    • 2008
  • Since measuring the size of kidney with sonography becomes an important index for diagnosis, treatment, and prognostic prediction in kidney disease, the accurate measurement and evaluation on this are clinically very important. Accordingly, the purpose of this study was to increase reproducibility and objectivity in measuring the size of kidney by enumerating factors that have an impact for measurement. It targeted 44 adults in Korea at the age of 21-27. It measured in order for both kidneys to be seen most largely while changing a subject-examiner's position in a state of fasting for 8 hours and a transducer's approaching direction. It compared a size of kidney by measuring, respectively, with the same method in 30 minutes and in 1 hour after drinking water in 700-1,000cc. In case of the lateral approach scan in decubitus position, the average length of the kidney both to the right and the left and the deviation of measurement to be the largest. In NPO(None Per Oral) state, the average length in the right kidney was 10.19cm, and the average length in the left kidney was 10.33cm. In 60 minutes after taking moisture, the average length in the right kidney was 10.94cm, and the average length in the left kidney was 11.13cm. In comparing the average length of the kidney in NPO state and its average length in 60 minutes after taking moisture, the size swelled by 7.3% for the length in the right kidney and by 7.7% in the left, thereby having been indicated to be statistically significant(P<0.003). The measurement in a size of kidney by using ultrasound may be measured differently depending on a patient's state of taking moisture and a transducer's approaching direction. It is thought that when the measurement in a size of kidney is especially important clinically, the intake and intake time in moisture need to be considered and that measuring with the posterior approach in prone position is a good method aiming to increase reproducibility in measuring length of the kidney.

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

  • Cho Won Pyo
    • Journal of Korean Academy of Oral and Maxillofacial Radiology
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    • v.2 no.1
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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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A Study on Verification of Shoe Last Grading System Based on Foot Measuring Data (발계측 자료에 기초한 신골 할출 시스템의 검증에 관한 연구)

  • Park, Hae-Soo
    • Journal of the Ergonomics Society of Korea
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    • v.26 no.1
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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.

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

  • Nam, Jun-Seok;Baek, Chang-Sun;Kwon, Soon-Kwan;Kim, Dong-Hyun;Min, Kyung-Tak;Kim, Byoung-Gon;Lee, Sung-Ho
    • Fire Science and Engineering
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    • v.22 no.3
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    • pp.272-277
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    • 2008
  • This study is performed for propose that exactly equivalent length of TBP in the applied at water-based fire protection system. For predict the measuring position of equivalent length, we determined the measuring position using the FVM about pressure drop of TBP. For the reckon of the exact about measured value we compared with the result of FVM and we knew the similar value each other. Using the results we proposed the friction loss measuring position that inlet of main dirction is 20 times of appellation diameter in main pipe, outlet of main dirction is 10 times of appellation diameter in main pipe and outlet of branched direction is 20 times of appellation diameter.

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

  • Park, Soo-Jin;Yang, Chae-Ha;Kim, Kwang-Joong;Kwon, Young-Kyu
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.21 no.1
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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.