• 제목/요약/키워드: Front to back ratio

검색결과 138건 처리시간 0.018초

인체 무게 중심 분할에 따른 500m 숏트트랙 스피드 스케이팅 출발 기술 분석 (Analysis of the 500M Short track speed skating starting motion according to the center of gravity position ratio)

  • 백진호;정남주;한기훈;이용구;윤동섭;이용식
    • 한국운동역학회지
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    • 제13권3호
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    • pp.199-215
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    • 2003
  • The purpose of this study was to attempt new starting motion and supply present starting motion in the 500M short track speed skating according to the center of gravity position. The center of gravity position ratio was divided starting motion into five(type A : front 80%-back 20%, type B front 70%-back 30%, type C : front 50%-back 50%, type D : front 30%-back 70%, type E : front 20%-back 80%). The three dimension motion analysis with DLT(direct linear transformation) method was executed using two video cameras. The following conclusion was that It was appear that reaction and execution time in starting motion was the most short in type B. It was characteristic that step of skaters was shorten and center of gravity position ratio was not effect to change of the step in each event. It was appear that the displacement of type D and type E were longer than that type A and type B during the starting motion. It was appear that skill types of center of gravity position ratio to the front were lower than that to the back and contract a posture. Observing the above, it was conclusion that skill type B of center of gravity position ratio to the tent was more effect than that to the back. But it is important that these skill type was most used to the competition and estimate the result.

Front-to-Back Ratio Improvement of a Microstrip Patch Antenna Loaded with Soft Surface Structure in a Partially Removed Ground Plane

  • Lee, Hong-Min
    • Journal of electromagnetic engineering and science
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    • 제12권4호
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    • pp.247-253
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    • 2012
  • This study presents a new, simple method for improving the front-to-back (F/B) ratio of a microstrip patch antenna. The back radiation of the microstrip patch antenna is reduced by removing some metallic parts around the ground plane and placing a new soft-surface configuration, consisting of an array of stand-up split-ring resonators on a bare dielectric substrate near the two ground plane edges. Compared to the F/B ratio of a conventional microstrip patch antenna with a full ground plane of the same size, our proposed microstrip patch antenna experimentally achieves an improved F/B ratio of 9.6 dB.

고출력 혼 안테나의 후엽감쇄 연구 (Front-to-Back Ratio Improvement of a High-Power Horn Antenna)

  • 신재윤;심홍석;이병현;이정란;우종명
    • 한국전자파학회논문지
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    • 제29권5호
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    • pp.389-392
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    • 2018
  • 본 논문에서는 고출력 마이크로파 시스템에 적용하기 위해 1.57 GHz에서 단락구조물을 이용하여 최대 후엽감쇄 특성을 갖는 혼 안테나를 제안하였다. 제안된 안테나는 시뮬레이션으로 단락구조물 증가에 따른 후엽감쇄 특성을 최적화시켰고, 최종 3단 단락구조물을 설계하였다. 그 결과 제작된 혼 안테나의 FBR(Front-to-Back Ratio)은 기본형 혼 안테나 23.47 dB를 기준으로 3단 단락구조물을 부착 후 47.2 dB로 23.7 dB가 개선됨을 확인하였다.

국내 의류 업체의 바지 그레이딩 실태 조사 (A Survey on Pants Grading of the Korean Apparel Industry)

  • 이미숙
    • 한국의류산업학회지
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    • 제11권6호
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    • pp.896-903
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    • 2009
  • The purpose of this study was to compare and analyze the present condition of pants grading and the methods for the specific dimensional increments, a questionnaire has been conducted. For the questionnaire, 16 casual wear brands, which were on higher ranking of sales in Korea, were selected. The results are summarized as follows. Based on the pants grading data resulting from the research conducted on the (16) domestic clothing brands, the grading method could be classified into three different types. According to the criteria; i.e., the front and back divided by crease of pants and the deviation ratio of the grading increments of the waist and the hip girth, the grading types were (1) G1: front 5:5, back 5:5, (2) G2: front 4:6, back 4:6, and (3) G3: front 4:6, back 3:7.

Effect of Loading Split-Ring Resonators in a Microstrip Antenna Ground Plane

  • Lee, Hong-Min
    • Journal of electromagnetic engineering and science
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    • 제15권2호
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    • pp.120-122
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    • 2015
  • This study presents a new, simple method for improving the front-to-back (F/B) ratio of a microstrip patch antenna (MSA) based on surface wave suppression. The back radiation of the MSA is significantly reduced by using the meandered ground plane edges and placing split-ring resonators (SRRs) in the middle of the meandered slots. By loading SRRs near the center of the meandered ground plane edges, some parts of the diffracted back-lobe power density can be reduced further. Compared to the F/B ratio of a conventional MSA with a full ground plane of the same size, an improved F/B ratio of 18 dB has been achieved experimentally for our proposed MSA.

전후방비가 개선된 Cavity-Backed 마이크로스트립 다이폴 배열 안테나 설계 (Design of Cavity-Backed Microstrip Dipole Array Antennas with Enhanced Front-to-Back Ratio)

  • 유동균;전정익;이형기;최학근
    • 한국전자파학회논문지
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    • 제20권1호
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    • pp.37-44
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    • 2009
  • 본 논문에서는 TRS(Trunked Radio System: $806{\sim}866\;MHz$) 대역의 전후방비 특성이 우수한 이동통신 기지국용 배열 안테나를 제안하였다. 제안된 배열 안테나는 양호한 전후방비 특성을 갖도록 후면에 캐비티를 둔 마이크로스트립 다이폴 안테나를 복사 소자로 하고, 이를 $5{\times}3$ 배열한 안테나이다. 제안된 안테나의 타당성을 보이기 위하여 $5{\times}3$ 배열 안테나를 설계 제작하고 복사 특성을 측정하였다. 복사 특성 측정 결과, 제안된 배열 안테나는 사용 주파수 범위에서 이득 13.3 dBi 이상, 전후방비 40 dB 이상을 갖는 것으로 나타났다. 이로서 본 논문에서 제안된 배열 안테나는 후방 로브 특성이 우수한 기지국 안테나로 널리 이용될 수 있음이 확인되었다.

여자 500m 쇼트트랙 스피드 스케이팅의 스타트 기술분석 (Analysis of the Female 500m Sprint Starting Motion in Short Track Speed Skating)

  • 백진호;곽창수;정남주
    • 한국운동역학회지
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    • 제14권3호
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    • pp.285-299
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    • 2004
  • The purpose of this study is to identify female 500m sprint start motion by the center of gravity position in short track speed skating. The center of gravity position ratio was divided into three type(type A front : 80%-back : 20%, type B front : 70%-back 30%, type C front: 50%-back : 50%). Three video cameras were used for 3D motion analysis with DLT method and the results were as follows: The elapsed time in starting motion was appeared that type B was the shortest and type A was the longest. It was appear that the stroke length of type A was longer than that type B and C during starting phase. This result was similar to displacement of center of gravity. It was appeared that skill type of center of gravity position ratio type B' ankle and knee joint angle were lower than that of type A and C. Observing these results it was conclusion that skill type B of center of gravity position ratio was more faster than that of type A and C. But it is important that these skill type needed to verifying more subjects.

청년기 여성의 상반신 체형 연구 (A Study of the Young Aged Women′s Bust)

  • 엄정옥;문명옥
    • 복식
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    • 제50권5호
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    • pp.117-130
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    • 2000
  • The purpose of this thesis is to offer basic data for clothing design which is intended to apply appropriate shape and capacity to clothes. The following are the analyzed results of an investigation which was conducted to characterize the upper half of the female body of 193 women whose ages are 18 to 25, taking part in this investigation. According to the results of analyzing young women's bust, I came to find a large individual difference of the wide varying factor numbers at the items of the side feature, the body stance, and the dart quantity. For the analysis of the female's upper body, 11 factors are used. The are as follows: Factor 1. width of the bust Factor 2. height of the bust and length of the arm Factor 3. side thickness of the bust and the upside type Factor 4. length of the bust on the front Factor 5. length of the bust on the back Factor 6. salient ratio of the breast Factor 7. width of the neck. the armhole, and measurement of the droop Factor 8. length of the shoulder Factor 9. flat ratio of the bust Factor 10. inclination of the shoulder factor 11. form of the back The shape of young women's upper bodies can be divided into four groups. The character ization of each group are as follows : Group 1 . 28.5% of the women who take part in this investigation belong to Group 1 These women have the shortest body, with a longer length of the front than the back and more thickness on the front than the back. Group 2. 21.1% of the women who take part in this investigation belong to this group. They show a longer length of the back and more thickness of the back than the front. In addition, this group is bent forward. Group 3. This group is the mast common type, showing the shortest and thickest character. 37.8% of the women who take part in this investigation have this bust character Group 4. 12.4% of the women belong to Group 4. They possess the highest and fattest character, skewing smaller necks, armholes, and waists than the other groups. This group also shows the drooping shoulders.

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모음 인식과 벡터 양자화를 이용한 화자 인식 (Speaker Identification Based on Vowel Classification and Vector Quantization)

  • 임창헌;이황수;은종관
    • 한국음향학회지
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    • 제8권4호
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    • pp.65-73
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    • 1989
  • 본 연구에서는, VQ(vector quantization)와 모음 인식에 기초한 화자 인식 알고리즘을 제안하고, 기존의 VQ를 사용한 화자 인식 알고리즘과 성능을 비교하였다. 제안된 화자 인식 알고리즘은 모음 분리, 모음 인식 그리고 평균 distortion양을 계산하는 3개의 과정으로 구성되며, 이때 주어진 음성 신호로부터 모음 부분을 분리하기 위해 RMS 에너지, BTR(Back-to-Total cavity volume Ratio) 그리고 SFBR(Signed-Front-to-Back maximum area Ratio)이 라는 3개 의 Parameter를 사용하였다. 입력 음성 신호의 SNR이 20 dB이고 정확한 모음 분리가 수행되었을 때, 제안된 화자 인식 알고리즘의 성능이 기존의VQ를 사용한 화자 인식 알고리즘의 성능보다 대체로 좋았으며, 입력 신호가 전화선을 통과한 신호이고 잡음이 있는 경우에도 유사한 결과를 얻을 수 있었다

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20대 여성의 하반신 체형 유형에 따른 플레어스커트의 패턴 설계 (Pattern Making of the Flared Skirt According to the Lower Body Somatotype of the 20's Women)

  • 이연순;류지현;김경아
    • 한국의류산업학회지
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    • 제10권5호
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    • pp.660-667
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    • 2008
  • The purpose of this study was to modify a Flared Skirt for women according to the somatotype of lower body. The subjects for the wear test were 3 students, who were in $mean{\pm}1{\sigma}$ each somatotype. The results of this study are as follows: First, the Flared Skirt pattern was modified according to each type. The front waist line rising measurement proposed for type 1 and type 2 were 0.5cm, because of lower front silhouette with waist shape. The back waist line rising measurement proposed for type 2 was 1cm and type 3 was 0.5cm, because of lower back shape with hip. Second, the wave-height of nodes were regular at front and back in type 1. Also, the wave-height of nodes were evenly distributed side and center. The variation ratio of wave-height of back nodes were lower than existing pattern in type 2 and type 3. It means the variation ratio of wave-height of back nodes were regular in modification pattern. Altogether, modification patterns were more regular and lower than existing pattern in the number of nodes, the distribution ratio of nodes, the wave-height of node, the variation ratio of wave height of nodes.