• Title/Summary/Keyword: notch length

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A Study on the Flaw Evaluation in the Straddle Mount Type Low Pressure Turbine Disc Using Phased Array Ultrasonic Technique (위상 배열 초음파 기법을 이용한 Straddle Mount형 저압 터빈 디스크 결함 평가에 관한 연구)

  • Yang, Seung-Han;Yoon, Byung-Sik;Kim, Yong-Sik
    • Journal of the Korean Society for Nondestructive Testing
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    • v.26 no.4
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    • pp.231-238
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    • 2006
  • Nondestructive examination for low pressure turbine disc in standard nuclear power plant using phased array technique was studied. For this purpose, disc mockups were made and notches were machined in the mockups. Detection and length sizing by different methods are compared. Depth of deep notches could be measured by using AATT(absolute arrival time technique) or RATT(relative arrival time technique) but shallow notches that must be detected in early stage couldn't be measured by these two methods. For this case, notch depth was estimated by using signal response angle range and preyed usefulness.

A Fracture Mechanic Study on Life Prediction of Surface Cracks at Elevated Temperature (고온화 표면균열의 수명예측에 관한 파괴역학적 연구)

  • Chang-Min,Suh;Young-Ho,Kim;Bung-Ho,Son;Sang-Yeub,Oh
    • Bulletin of the Society of Naval Architects of Korea
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    • v.27 no.3
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    • pp.100-106
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    • 1990
  • Microcracking of type 304 stainless steel at $593^{\circ}C(1,100^{\circ}F)$ has been studied, in particular, initiation, growth, and coalescence of fatigue and creep microcracks on smooth specimens and small notch specimens via surface replicas and photomicrographs. Quantitative information, such as, initiation period, growth, and coalescence behavior, statistical distributions of crack length, density of cracks, distribution patterns and crack growth properties, were obtained. From this study, the fracture process, fatigue life, and creep life prediction characterized by the growth of surface microcracks have been analysed by a new approach unifying the conventional approaches based on the final fracture of materials with the fracture mechanics approach. Knowledge of these parameters is critical for the application of fracture mechanics to fatigue and creep life assessment, and the damage evaluation of structures at elevated temperature.

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A Study on the Collar Construction Factors of the Women's Tailored Jacket (여성복 테일러드 재킷의 칼라제작요인에 관한 연구)

  • Kim, Gu-Young;Kim, Yeo-Sook
    • Fashion & Textile Research Journal
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    • v.10 no.6
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    • pp.947-954
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    • 2008
  • The purpose of this research is to find out related factors to obtain the best collar pattern of the women's tailored jacket by analyzing the difference of the shapes between the drafted pattern and that of being stitched. The experimental conditions established are as follows. The position and angle of its break point, the notch and the width of the collar and lapel are kept unchanged. The collar decrease in neckline edge and the top collar larger than the under collar. The crossing point of gorge line is changed to make the collar's roll line straight. When the pattern is changed to make the outline of the lapel straight, the amount of cloth is changed too. According to the experimental conditions, The experimental clothes using muslin were made to. put on the manikin and the suitable methods of making the collar pattern were decided. In order to find out the influence of fabric materials on the jacket' shapes, Three kinds of wool fabrics were used and the results were evaluated. Summary of the research is as follows. When 0.5cm of the neckline edge is shortened, the standing part of the collar has less wrinkles, and its position looks natural and lastly, the material has slightly affected the collar's condition. It is desirable to make the top collar 0.2cm longer than the under collar. But the length should be different according to the fabric material. It it is thick cloth, the length has to be extended. To make the roll line straight, 0.4cm of the crossing point of gorge line should be corrected. The thick cloth needs more correction. To make the lapel's outline straight, it needs outwardly round 0.2cm more and materials make little difference to affect the shape.

Compression Strength Size Effect on Carbon-PEEK Fiber Composite Failing by Kink Band Propagation

  • Kim, Jang-Ho
    • KCI Concrete Journal
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    • v.12 no.1
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    • pp.57-68
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    • 2000
  • The effect of structure size on the nominal strength of unidirectional fiber-polymer composites, failing by propagation of a kink band with fiber microbuckling, is analyzed experimentally and theoretically. Tests of novel geometrically similar carbon-PEEK specimens, with notches slanted so as to lead to a pure kink band (without shear or splitting cracks), are conducted. The specimens are rectangular strips of widths 15.875, 31.75. and 63.5 mm (0.625, 1.25 and 2.5 in and gage lengths 39.7, 79.375 and 158.75 mm (1.563, 3.125 and 6.25 in.). They reveal the existence of a strong (deterministic. non-statistical) size effect. The doubly logarithmic plot of the nominal strength (load divided by size and thickness) versus the characteristic size agrees with the approximate size effect law proposed for quasibrittle failures in 1983 by Bazant This law represents a gradual transition from a horizontal asymptote, representing the case of no size effect (characteristic of plasticity or strength criteria), to an asymptote of slope -1/2 (characteristic of linear elastic fracture mechanics. LEFM) . The size effect law for notched specimens permits easy identification of the fracture energy of the kink bandand the length of the fracture process zone at the front of the band solely from the measurements of maximum loads. Optimum fits of the test results by the size effect law are obtained, and the size effect law parameters are then used to identify the material fracture characteristics, Particularly the fracture energy and the effective length of the fracture process zone. The results suggest that composite size effect must be considered in strengthening existing concrete structural members such as bridge columns and beams using a composite retrofitting technique.

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Studies on Miniaturization and Notched Wi-Fi Bandwidth for UWB Antenna Using a Wide Radiating Slot (넓은 방사 슬롯을 이용한 초광대역 안테나의 소형화와 Wi-Fi 대역의 노치에 관한 연구)

  • Beom, Kyeong-Hwa;Kim, Ki-Chan;Jo, Se-Young;Ko, Young-Ho
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.22 no.2
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    • pp.265-274
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    • 2011
  • In this paper, it is studied on wide radiating slot antenna's miniaturization for ultra wide-band(UWB) technologies and notch structure to prevent interference between UWB systems and existing wireless systems for using Wi-Fi service of IEEE standards 802.11 a/n. Proposed antenna that wide slot is decreased from $\lambda/2$ to $\lambda/4$ length of resonant frequency has decreased by 72 % compared with conventional antenna. And optimized T-shaped CPW-fed stub has satisfied UWB bandwidth for 3.0~11.8 GHz. Then, creating 2-order Hilbert curve slot line in the stub's patch area, 4.9~5.6 GHz that centered frequency is 5 GHz is eliminated. Finally, the designed antenna constructed on FR4-epoxy has $20{\times}15\;mm^2$ dimension. The measured results that are obtained return loss under -10 dB through 3.2~11.8 GHz without Wi-Fi bandwidth, a linear phase characteristic, a stable group delay, and omnidirectional radiation patterns are presented.

Laryngeal Measurement on Neck CT (경부 전산화단층촬영상에서 후두계측)

  • 유영채;오재식
    • Korean Journal of Bronchoesophagology
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    • v.2 no.1
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    • pp.71-81
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    • 1996
  • The normal larynx locates to the front of the neck symmetrically and the thyroid notch lies in the center of the neck, but practically the larynx is not symmetric in all people. From a clinical point of views, there are vague cases to decide whether a disordered laryngeal structure is within normal variations or a pathologic condition. The purpose of this study is to investigate the anatomy of the laryngeal framework in normal population. Authors investigate various measures of normal laryngeal framework, such as symmetry and length of the larynx, levels of the hyoid bone and vocal cord and angle of thyroid cartilage by using calipers and protractor on 45 cases of neck CT. The results are summerized as follows. 1. The laryngeal framework was asymmetric to a greater or lesser extent in most cases with directional preponderance to the right side. The degree of asymmetry did not differ among different age groups and between seres. 2. The level of the hyoid bone ranged from C2-C3 vertebrae to C5-C6 intervertebral space with most frequent level of C5. 3. The level of the vocal cord ranged from 01 vertebra to C6-C7 intervertebral space with most frequent level of C5. 4. The angle of thyroid cartilage ranged from 58 degree to 100 degree with average of 81.5 and mean angle between both thyroid alae were 77.24 degree in male and 87.88 degree in female.

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A Comparative Study on the Sewing Teaching of Tailored Jacket (테일러드 재킷 봉제방법 비교 연구 - 의복구성 교재를 중심으로 -)

  • Shin, Jang-Hee;Sohn, Hee-Soon
    • Journal of the Korea Fashion and Costume Design Association
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    • v.11 no.2
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    • pp.75-84
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    • 2009
  • The following research analyzed the sewing teaching of the tailored jacket shown in fashion textbooks, which are currently used in universities and educational organizations in the fashion industry. To analyze the sewing teaching of tailored jackets, we analyzed 35 textbooks in the market. Among them we used 14 textbooks which dealt with the patter formation method of tailored jackets, and cutting and sewing methods. First, the stitching direction and the location of attachment varied. The type of sticking tape and its position also differed, emphasizing the need to make an institutionalized education material which is based on the characteristic of the fabric and its silhouette. Second, controlling the ease length of the right side sewing princess line, or information about the shoulder line and sleeve line of the notch as not specifically shown in the textbooks. Furthermore, not many textbooks showed how to pull the lower part of the texture out of sight, nor did they explain why this needed to be done. Third, the lining is usually slightly larger than the outer texture of the clothing, as the lining is usually tugged in the sewing process, and this method makes the clothes more comfortable. The method of sewing the princessline $0.2{\sim}0.3cm$ outside the outer pattern was the most recommended. The center-back side was usually 2cm in activity measurements, but it turned out that a textbook which required ease treatment on the shoulder line did not do so on the lining material. The textbooks used in this research dealt only with how to manufacture a tailored jacket without full explanation about textures which could influence the manufacturing. The production method and process differed between different textbooks, showing the need to make a institutionalized education material. In a quickly-changing era where there is rapid change in the dressmaking procedure, we need to help students understand the process more easily through a formalized education process.

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Measurement of rock fracture toughness under mode I, II & mixed-mode conditions by using disc-typed specimens (인장, 전단 및 혼합모드에서 디스크 시험편을 이용한 암석의 파괴인성 측정에 관한 연구)

  • 장수호;이정인
    • Tunnel and Underground Space
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    • v.9 no.4
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    • pp.315-327
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    • 1999
  • Rock fracture mechanics has been widely applied to blasting, hydraulic fracturing, rock slope and many other practical problems in rock engineering. But a measuring method for the fracture toughness of rock, one of the mort important parameters in fracture mechanics as an intrinsic property of rock, has not been yet well established. To obtain mode I rock fracture toughness, the more favorable disc-typed specimens such as CCNBD, SCB, chevron-notched SCB and BDT were used in this study. Rock fracture toughness under mixed-mode and mode II conditions was measured by using the STCA applied to the CCNBD specimen. Size effects such as specimen thickness, diameter and notch length on fracture toughness were investigated. From the mixed-mode results, fracture envelops were obtained by applying various regression curves. The mixed-mode results were also compared with three mixed-mode failure criteria. In each fracture toughness test, acoustic emission was measured to get the data for determining the load levels of different crack propagation patterns.

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A Study on the Yi Mae-Bang's Salpurichum Costume (이매방 살풀이춤[중요무형문화재 제 97호] 복식 연구)

  • Jeong, Ye-Hee
    • Journal of the Korean Society of Costume
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    • v.63 no.7
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    • pp.31-48
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    • 2013
  • It goes without saying that Yi Mae-Bang, as the sole owner of two of the intangible cultural assets including No. 27 Seungmu in 1987 and No. 97 Salpuri Chum, is a top-notch Korean traditional dancer. Moreover, in regards to traditional clothing, he is also known as the only traditional dancer who directly performs on stage as well as analyzes traditional clothing in order to apply them into his own dance performances by designing and producing them to meet his artistic spirit. In order to examine how Yi Mae-Bang's unique and creative stage clothing was developed, and what kind of process it went through to possess its unique style, which draws the attentions of people with its harmony of beauty and dance, this research first examined the change of the composition through the yearly picture data. Before 1984, the composition of the Salpuri Chum clothes changed by putting on 'Jeogori' on the 'Mudong-Bok' without the 'Kweia' (sleeveless), and in 1999 'Mudong-Bok' became widened with the decoration of embroidered hem making it more attractively colorful. after 2000 it became more splendidly adorned by embroidering hem on widened Mudong-Bok and tucking 'Kweja' in the layers which created silhouette like a dress that is seemingly wider and luxuriant than a skirt. One of notable features of Yi Mae-Bang's Salpuri is that its cloth and cuff ribbons are lightly colored in different colors enclosing the tip part. As for the ribbons, it was also changed as time went by from direct-cutting of the cloth just like the A-line of Mudong-Bok to drawing a diagonal line less than 5cm above the ribbon and 8cm below the ribbon so that it takes the form of getting widened as it gets to the lower part, and its length was also elongated in proportion to that of the bottom of Mudong-Bok.

Eddy Current Testing using Encircling Differential Probe for Research Reactor Fuel Rods (외삽 차동형 탐촉자를 사용한 연구로용 핵연료봉의 와전류탐상)

  • Lee, Yoon-Sang;Kim, Chang-Kyu
    • Journal of the Korean Society for Nondestructive Testing
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    • v.21 no.5
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    • pp.561-564
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    • 2001
  • The cladding area of HANARO Research Reactor fuel rods should be checked not to have any defects larger than the size required at QA documents by using eddy torrent testing method doting fabrication process. To apply eddy current testing inspection to the fuel rods, encircling differential probes and standard specimen were designed and fabricated. The impedance of the fabricated probes was measured with impedance analyzer in order to cheek that the probe has a suitable impedance for the inspection frequency, and with this probe and MIZ-40A eddy current equipment, the detectability of this probes was investigated. The developed probes could detect artificial notch with 2mm length 10% depth of cladding thickness in cladding area. In addition, the probe was successfully applied to detect the defects in cladding area doting fabrication of the research reactor rods.

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