• 제목/요약/키워드: the left-handed

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A Broadband Half-Mode Substrate Integrated Waveguide Quadrature Wilkinson Power Divider Using Composite Right/Left-Handed Transmission Line

  • Eom, Dong-Sik;Lee, Hai-Young
    • Journal of electromagnetic engineering and science
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    • 제17권1호
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    • pp.9-13
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    • 2017
  • In this work, a broadband composite right/left-handed (CRLH) half-mode substrate integrated waveguide (HMSIW) quadrature Wilkinson power divider is proposed. The proposed CRLH-HMSIW quadrature power divider includes a microstrip Wilkinson power divider on the transition structure between the microstrip and HMSIW, and two thru transmission lines for the HMSIW and the CRLH-HMSIW. The measured amplitude, phase difference and isolation between the two output ports of the proposed structure have 1 dB, ${\pm}5^{\circ}$ and less than -15 dB in a wide frequency range of 4.1-6.68 GHz with 47.9% bandwidth, respectively.

Considerable Size Reduction of Dipole Antenna with a Compact and Broadband Balun

  • Han, Heeje;Kim, Hyungpyo;Kim, Hongjoon
    • Journal of Electrical Engineering and Technology
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    • 제11권6호
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    • pp.1777-1782
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    • 2016
  • A compact and broadband balun is designed using a conventional right-handed transmission line (RHTL) and a left-handed transmission line (LHTL) with lumped elements only. The proposed balun maintains a phase difference of $180^{\circ}{\pm}12^{\circ}$ at the output ports for the frequency range of 1.27 GHz-2.69 GHz. Nevertheless, the circuit size is merely $9.5mm{\times}12.7mm$. To verify the performance of the proposed balun, we attached it to a dipole-type antenna and observed that the return loss is greater than 10 dB for the frequency range between 1.86 GHz and GHz. The radiation pattern and peak gain are similar to those of the dipole antenna with a conventional balun.

股關節外轉の時の中臀筋の筋力及び活動電位の變化に關する硏究 (A Myometric and Electromyographic Analysis of Hip Abductor Musculature in Healthy Right-Handed Persons)

  • 권혁철
    • 한국전문물리치료학회지
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    • 제5권4호
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    • pp.41-51
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    • 1998
  • The right hip abductor musculature has been reported to demonstrate "stretch weakness" attributable to chronic elongation imposed by standing posture common to right-handed healthy persons. Kendall and associates have described the concept of "stretch weakness",. The purpose of this study was to assess isometric hip abduction torque and surface electromyographic activity (using MYOMED 432) in a sample of 40 healthy right-handed persons (20 male, 20 female), all of whom agreed to participate in the study, and compare side difference in the hip abductor musculature. In order to assure the statistical significance of the results, the paired t test was applied at the .05 level of significance. The results were as follows: 1) The difference in apparent leg length of right and left legs was significant at the .05 level. 2) There was a significant difference between right and left pelvic height (standing position) at the 05 level measurements, and scapula height at the .05 level. 3) Power measurements and action potentials of right hip abductor were greater than the left hip abductor regardless of the range of joint motion (inner range, outer range) 4) The difference in muscle power and action potentials according to inner or outer range of both hip abductor were significant at the .05 level. 5) In supine during active left hip abduction, the appearance of action potentials in the right hip abductors is indicative of contra-lateral effect (p<.05) These results suggest: In healthy right-handed persons, the apparent leg length on the right is longer than on the left, and pelvic height is elevated on the right side. Muscle those and muscle action potentials of the right hip abductor are higher than those of the left hip abductor in the lengthened position. Therefore, the results in this study are contrary to Kendall's. This type of study should be carried out in many physical therapy departments.

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인간행동습성과 피난계단의 설계에 관한 연구 (A Study on Human Behavioral Pattern and the Design of Escape Stair)

  • 이강훈
    • 한국화재소방학회논문지
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    • 제12권4호
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    • pp.3-12
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    • 1998
  • 이 연구는 인간의 중요한 행동습성 중의 하나언 좌회전숨성윷 건축설계에 고려활 경우, 고총건 불의 지상총 피난계단은 좌회전계판(피난층으로 내려갈 때 좌회전하여 내려가도록 설계원 계딴) 으료 설계하는 것이 재실자가 보다 더 안전하고 빠료게 피난하는 데 효과적이라는 것윷 현장조사 및 실험을 통하여 규명하고자 한 것이다. 2 20충 규모의 고층건불윷 이용하여 펴난자가 펴난총으로 내려갈 때의 펴난속도를 측정한 결과, 오른손잡이의 경우는 좌회전계단의 사용이 우회전계탄(피난층£로 내려갈 때 우회전하여 내려가 도흑 설계된 계란)의 사용시보다 편하고 빠른 반면, 왼손잡이의 경우는 우회전계란의 사용이 좌회 전계딴의 사용시보다 편하고 빠르다는 것윷 확인하였다, 그려고 우려나라논 94% 이상의 사람이 오른손잡이인 것으로 조사되었다 그러나 현재 우려나라 고층건울의 지상총 펴난계단은 조사결과 7 76% 이상이 우회전계딴임을 알 수 있었다. 이렇게 잘못 설계원 펴난계딴의 실태를 감안해 볼 때 이의 시정을 위해서는 판원볍규의 피난계딴 구조기푼에 고총건물의 지상층 펴난계딴은 좌회전계 딴요로 설계하도록 규정할 펼요가 있다.

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건강한 오른손잡이 남성의 자세분석에 따른 추나치료의 효과 (Posture Analysis of Healthy Right-handed Male and the Effect of Chuna Treatment)

  • 김민수;이지영;신희라;염승룡;권영달
    • 한방재활의학과학회지
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    • 제27권3호
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    • pp.125-136
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    • 2017
  • Objectives The present study was designed to analyze the posture pattern of healthy right-handed male and to investigate the effect of Chuna treatment. Methods Twenty healthy right-handed male were selected in this study. Body posture was measured by Body $Style^{(R)}$. After that, subjects received Chuna treatment on lumbar and pelvis area. Finally, the 2nd measurement was carried out. Results In shoulder height, left shoulder was higher than right one. In pelvic height, right iliac crest was higher than left, followed by longer right leg than left. In lower limb angle suggesting valgus or varus knee. In height of scapula inferior angle, right seemed higher than left. After the Chuna treatment, shoulder height, pelvic height, and leg length difference showed significant improvement. Other variables showed improvement but it was not significant. Conclusions These results suggest that right-handed male have some characteristic posture pattern because of their daily life habits, and Chuna treatment can be effective in correcting bad posture.

고관절 외전시 중둔근의 근력 및 활동전위 변화에 관한 연구 (A Myometric and Electromyographic Analysis of Hip Abductor Musculature in Healthy Right-Handed Persons)

  • 권혁철
    • The Journal of Korean Physical Therapy
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    • 제2권1호
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    • pp.35-46
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    • 1990
  • The right hip adbuctor musculature has been reported to demonstrate 'stretch weakness' attributable to chronic elongation imposed by standing posture common to right-handed healthy persons. Kendall and associates have described the concept of 'stretch weakness'. The purpose of this study was to assess isometric hip abduction torque and surface electro-myographic activity (using MYOMED 432) in a sample of 40 healthy right-handed persons (20 male, 20 female), all of whom agreed to participate in the study, and compare side difference in the hip abductor musculature. In order to assure the statistical significance of the results, the paired t-test was applied at the .05 level of significance. The results were as follows : 1. The difference in apparent leg length of right and left legs was significant at the .05 leve1. 2. There was a significant difference between right and left pelvic height (standing position) at the .005 level measurements, and scapula height at the .05 level. 3. Power measurements and action potentials of right hip adbuctor were greater than the left hip adbuctor regardless of the range of joint motion (inner range, outer range). 4. The difference in muscle power and action potentials according to inner or outer range of both hip abductor were significant at the .05 level. 5. In supine during active left hip abduction, the appearance of action potentials in the right hip abductors is indicative of contra-lateral effect (p<.005). These results suggest : In healthy right-handed persons. the apparent leg length on the right is longer than on the left, and pelvic height is elevated on the right side. Muscle torque and muscle action potentials of the right hip adbuctor art higher than those of the hip abductor in the lengthened position. Therefore, the results in this study are contrary to Kendall's. This type of study should be carried out in many physical therapy departments.

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Left handed Z-DNA helices and B-Z junctions

  • 나도선
    • 미생물과산업
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    • 제12권1호
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    • pp.4-8
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    • 1986
  • DNA is a flexible molecule that adopts a variety of conformations. Left-handed helices have been demonstrated in synthetic DNA polymers (reviewed in Ref.1-2) and in segments of DNA restriction fragments (3) and recombinant plasmids (4-8). Other DNA conformations such as cruci forms and bent structures have also been demonstrated. Thus DNA micro heterogeneity has been demonstrated in a variety of systems (9-11). The role of the static and dynamic structures and properties of DNA in gene expression has been reviewed(1,12).

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유효 매질 접근법과 분산 FDTD법을 이용한 LHN 해석 (Using a Dispersive FDTD Method Effective Medium Analysis about Left Handed Material)

  • 황세훈;이정엽;정현교
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2005년도 제36회 하계학술대회 논문집 C
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    • pp.2348-2350
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    • 2005
  • LHM (Left Handed Material)은 특정 주파수 범위에서 음의 유전율과 투자율을 가지는 물질이며 유효 유전율과 투자율은 분산 특성을 가지고 로렌츠(Lorentz) 물질과 비슷한 형태를 가진다. 본 논문에서는 FDTD (Finite Difference Time Domain) 법을 바탕으로 한 PLRC (Piecewise Linear Recursive Convolution) 법을 이용하여 LHM 내의 유효 전파특성을 모의한다. 모의실험 결과는 음의 유전율과 투자율을 가지는 주파수 범위를 보여준다.

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금속과 왼손잡이 메타-물질의 경계면에서 형성되는 표면 폴라리톤의 전파 특성 (Propagation of surface polaritons at the interface of metal and left-handed metamaterial)

  • 윤재웅;송석호;오차환;김필수
    • 한국광학회지
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    • 제15권2호
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    • pp.89-99
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    • 2004
  • 금속에서의 흥미로운 광학적 특성들은 주로 표면 폴라리톤(surface polaritons: SP)의 기여에 의해 나타난다. 물질상수(유전율과 투자율)가 모두 음수인 왼손잡이 물질(left-handed materials: LHM)의 표면에서도 두 종류의 SP인 표면 전기-폴라리톤(surface electric-polariton: SEP), 또는, 표면 자기-폴라리톤(surface magnetic-polariton: SMP)이 형성되어 군속도와 위상속도가 서로 반전되는 경우가 발생한다. 본 논문에서는 금속물질과 LHM와 같은 메타물질(metamaterials)의 경계면에서 발생하는 SP의 전파특성을 분산관계를 통하여 분석하였다. 임의의 물질상수를 갖는 두 매질의 경계면에서 SEP와 SMP가 생성될 수 있는 일반화된 조건을 도출하였으며, 양쪽 매질을 통해 전파하는 에너지 비율의 차이에 의해 군속도와 위상속도가 반전된다는 물리적인 원인을 제안하였다. 도출된 SP 생성조건을 이용하여 금속물질과 메타물질의 경계면에서 전파하는 SEP와 SMP의 분산관계를 구하고, 주파수에 따라 다양한 SP의 전파특성이 나타날 수 있음을 보였다. SEP 및 SMP 분산관계로부터 구한 정량화 된 전파특성은 SP가 존재하기 위한 매질의 일반화된 조건과 에너지 전파 비율의 계산으로부터 얻은 결과와 일치함을 확인하였다. 특히, 두 매질 중 어느 한 매질이 LHM이 아니더라도 SP은 위상속도와 군속도가 반전되어 전파될 수 있음을 밝혀내었다.

분산 CRLH 전송선로 4중 모드 공진기를 이용한 이중-광대역 대역통과 여파기 설계 (Dual-Wideband Bandpass Filter Using Distributed Composite Right/Left-Handed Transmission Line Quad-Mode Resonators)

  • 성규제;김영
    • 한국항행학회논문지
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    • 제21권1호
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    • pp.84-89
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    • 2017
  • 본 논문은 CRLH (composite right/left handed) 전송선로 구조의 4중 모드 공진기를 이용하여 높은 대역간 격리도를 갖는 이중-광대역 대역통과 여파기를 설계하는 방법을 제안한다. CRLH 전송선로 구조를 해석하여 4중 모드 공진기의 s-패러미터와 공진 주파수를 유도하였다. 유도된 s-패러미터를 이용하여 새로운 구조의 이중-광대역 대역통과 여파기를 설계, 제작하였다. 측정 결과는 2.8-5.52 GHz, 9.68-12.26 GHz의 이중 통과대역에서 각각 1.08 dB, 2.01 dB의 삽입손실을 갖고, 6.34-8.42 GHz의 중간대역에서 38dB의 대역 격리도를 가져 설계 결과와 잘 일치하는 특성을 보여 주었다.