• 제목/요약/키워드: Low effective index

검색결과 540건 처리시간 0.032초

InGaAsP/InP RWG MQW-LD의 최적 설계 (The optimum design of InGaAsP/InP RWG MQW-LD)

  • 하홍춘;오수환;이석정;박윤호;오종환;홍창희
    • 한국광학회지
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    • 제7권4호
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    • pp.375-385
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    • 1996
  • 본 연구에서는 InGaAsP/InP RWG MQW-LD를 제작하기 앞서 이론해석으로부터 RWG MQW-LD의 도파로규격에 따른 측방향 유효굴절율차와 index-guided LD로 동작하는 임계 유효굴절율차의 값, 그리고 이러한 굴절율차에 따른 측방향에서의 단일모드 발진조건과 임계전류를 최소로 하기 위한 ridge 폭을 구하여 도파로를 설계하였다. 이론해석으로 부터는 순수한 index-guided LD로 동작하기 위한 측방향 임계 유효굴절율차 값은 일반적인 bulk층 보다는 약 2배 정도 큰 값인 약 0.015이었으며 도파로 설계에 있어서는 유효굴절율차가 0.015이며 측방향단일모드로 동작하기 위해서는 ridge 폭은 약 4.mu.m이하가 되어야 함을 알 수 있었다. 그리고 이때 임계전류값이 최소가 됨을 지적하였다.

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경제동물의 주요 경제형질에 대한 표지인자를 이용한 선발(MAS)의 효율성 (Efficiency of Marker Assisted Selection(MAS) over The Phenotypic Selection for Economic Traits in Economic Animals)

  • 전광주
    • Journal of Animal Science and Technology
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    • 제44권6호
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    • pp.669-676
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    • 2002
  • 유전표지인자를 이용한 선발(marker assisted selection; MAS)과 전통적인 표현형기록에 근거한 반응의 비교분석을 위하여 고정효과모델(deterministic model)을 이용하여 시뮬레이션을 하였다. 자신의 단일 기록을 이용한 경우와 자신의 기록과 자신의 표지인자 정보를 이용할 경우 유전력이 높을수록 MAS의 효율성이 38%정도 높게 나타났다. 그러나 유전력이 높은 경우(50%) MAS의 효율성은 약 1%정도로서 효율성이 대단히 낮은 것으로 나타났다. 자신의 기록과 부모의 표현형 정보에 표지인자 정보를 추가할 경우 MAS의 효율성은 27% 정도였으며 마찬가지로 유전력이 높은 경우에는 효율성이 0에 가깝게 나타났다. MAS의 효율성은 유전력이 낮을수록 그리고 이용한 표지인자의 유전적 변이가 클수록 효율성이 높아지는 것으로 나타났다.

Optimal Design of Dielectric-loaded Surface Plasmon Polariton Waveguide with Genetic Algorithm

  • Jung, Jae-Hoon
    • Journal of the Optical Society of Korea
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    • 제14권3호
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    • pp.277-281
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    • 2010
  • We propose a design and optimization method for a dielectric-loaded surface plasmon polariton waveguide using a genetic algorithm. This structure consists of a polymer ridge on top of two layers of substrate and gold film. The thickness, width and refractive index of the ridge are designed to optimize the figures of merit including mode confinement and propagation length. The modal analysis combined with the effective index method shows that the designed waveguide exhibits a fundamental propagation mode with high mode confinement while ensuring that the propagation loss remains relatively low.

오스웨스트리 장애지수를 이용한 홍화약침(CF)의 효과 (The Effect of CF Herbal Acupuncture by Oswestry Disability Index)

  • 조태성;손인석;권혜연;윤현민;장경전;송춘호;안창범;서정철
    • 대한약침학회지
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    • 제4권3호
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    • pp.15-20
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    • 2001
  • Objective: The aim of this study was to assess the effect of CF herbal acupuncture for low back pain by Oswestry Disability Index Methods: Ten patients with back pain were selected and CF herbal acupuncture was administered one time per 5 days after admission. The degree of improvement was evaluated by Oswestry Disability Index and visual analogue scale(VAS). Oswestry Disability Index consisted of eleven items and they were scored as 5 or 6 points per one item. Results: All of the 10 patients, after CF herbal acupuncture, showed decreased score by Oswestry Disability Index and VAS. It means that the patient's satisfaction increased after treatment. Conclusion: These results suggest that the CF herbal acupuncture was effective for low back pain

척추세움근 매선침치료가 만성요통환자에 미치는 효과 (Effects of the Embedding Acupuncture Treatments for Chronic Low Back Pain Patients)

  • 유덕주;정재영;정석희
    • 한방재활의학과학회지
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    • 제25권4호
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    • pp.105-112
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    • 2015
  • Objectives To investigate clinical effects of needle embedding acupuncture treatments for chronic low back pain patients. Methods 30 patients with chronic low back pain were recruited and randomized into two groups-the embedding acupuncture group or the placebo. At baseline, the age, height, weight, visual analogue scale (VAS), Oswestry disability index (ODI) scores were measured. And surface electromyography (SEMG) data of both erector spinae at L2, L4 level were also measured on both groups and asymmetry index (AI) were calculated. The embedding or placebo acupuncture treatment was performed on the erector spinae according to SEMG values; immediately after the first evaluation and 48 hours after the first visit. After 96 hours of intervention, the VAS, ODI score and SEMG of both erector spinae were measured again. Statistical significance was determined using the Wilcoxon signed ranks test or the Wilcoxon rank sum test. Results The mean VAS, ODI score after treatment was decreased significantly compared with baseline on both groups. And the VAS, ODI score and AI of the embedding acupuncture group was more decreased significantly than the placebo (p<0.05). Conclusions The results suggest that embedding acupuncture for chronic low back pain patients was effective on the VAS pain score, ODI score and AI of the erector spinae.

황련해독탕 약침 치료를 병행한 임신 중 좌골신경통을 동반한 요통 환자의 증례보고 (A Clinical Case Report on Traditional Korean Medical Treatment Including Hwangryunhaedok-tang Pharmacopuncture for Low Back Pain with Sciatica during Pregnancy)

  • 김선경;강수진;홍가경;최창민
    • 대한한방부인과학회지
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    • 제32권2호
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    • pp.138-147
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    • 2019
  • Objectives: This study was to report clinical effect and safety of Traditional Korean Medical Treatment including Hwangryunhaedok-tang Pharmacopuncture for pregnant woman with low back pain with sciatica. Methods: The patient who suffered from sudden low back pain with sciatica was treated with Hwangryunhaedok-tang Pharmacopuncture, acupuncture, moxibustion, herbal medication and cupping therapy during admission. Visual Analog Score (VAS), Oswestry Disability Index (ODI), McGill pain questionnaire-short form (SF-MPQ) were checked to measure the outcome. Results: After treatment, Visual Analog Score (VAS), Oswestry disability index (ODI), McGill pain questionnaire-short form (SF-MPQ) were considerably improved in this case. Conclusions: The results indicate that Traditional Korean Medical Treatment including Hwangryunhaedok-tang Pharmacopuncture is the effective therapy for low back pain with sciatica during pregnancy.

Photonic Quasi-crystal Fiber for Orbital Angular Momentum Modes with Ultra-flat Dispersion

  • Kim, Myunghwan;Kim, Soeun
    • Current Optics and Photonics
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    • 제3권4호
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    • pp.298-303
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    • 2019
  • We propose a photonic quasi-crystal fiber (PQF) for supporting up to 14 orbital angular momentum (OAM) modes with low and ultra-flat dispersion characteristics over the C+L bands. The designed PQF which consists of a large hollow center and quasi structural small air holes in the clad region exhibits low confinement losses and a large effective index separation (>$10^{-4}$) between the vector modes. This proposed fiber could potentially be exploited for mode division multiplexing and other OAM mode applications in fibers.

Impact of Pulmonary Arterial Elastance on Right Ventricular Mechanics and Exercise Capacity in Repaired Tetralogy of Fallot

  • Soo-Jin Kim;Mei Hua Li;Chung Il Noh;Seong-Ho Kim;Chang-Ha Lee;Ja-Kyoung Yoon
    • Korean Circulation Journal
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    • 제53권6호
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    • pp.406-417
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    • 2023
  • Background and Objectives: Pathophysiological changes of right ventricle (RV) after repair of tetralogy of Fallot (TOF) are coupled with a highly compliant low-pressure pulmonary artery (PA) system. This study aimed to determine whether pulmonary vascular function was associated with RV parameters and exercise capacity, and its impact on RV remodeling after pulmonary valve replacement. Methods: In a total of 48 patients over 18 years of age with repaired TOF, pulmonary arterial elastance (Ea), RV volume data, and RV-PA coupling ratio were calculated and analyzed in relation to exercise capacity. Results: Patients with a low Ea showed a more severe pulmonary regurgitation volume index, greater RV end-diastolic volume index, and greater effective RV stroke volume (p=0.039, p=0.013, and p=0.011, respectively). Patients with a high Ea had lower exercise capacity than those with a low Ea (peak oxygen consumption [peak VO2] rate: 25.8±7.7 vs. 34.3±5.5 mL/kg/min, respectively, p=0.003), while peak VO2 was inversely correlated with Ea and mean PA pressure (p=0.004 and p=0.004, respectively). In the univariate analysis, a higher preoperative RV end-diastolic volume index and RV end-systolic volume index, left ventricular end-systolic volume index, and higher RV-PA coupling ratio were risk factors for suboptimal outcomes. Preoperative RV volume and RV-PA coupling ratio reflecting the adaptive PA system response are important factors in optimal postoperative results. Conclusions: We found that PA vascular dysfunction, presenting as elevated Ea in TOF, may contribute to exercise intolerance. However, Ea was inversely correlated with pulmonary regurgitation (PR) severity, which may prevent PR, RV dilatation, and left ventricular dilatation in the absence of significant pulmonary stenosis.

소아 CT 촬영시 방사선 피폭과 저감화 방법 (Medical Radiation Exposure in Children CT and Dose Reduction)

  • 이정근;장성주;장영일
    • 한국콘텐츠학회논문지
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    • 제14권1호
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    • pp.356-363
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    • 2014
  • 소아 CT 촬영시 피폭선량을 저감시킬 수 있는 조건을 찾기 위하여 pediatric phantom을 이용하여 소아 방사선량을 비교 분석하였다. 관전류변동제어(tube current modulation:TCM) 방식과 low dose CT protocol(LDCTP)에 따라 소아 검사를 시행하였으며, 검사는 brain, chest, abdomen-pelvis 부위를 전산화 단층촬영 장치를 이용한 3개의 검사 프로토콜을 사용하였다. 거의 모든 MDCT 장치는 volume CT dose index(CTDIvol), dose length product(DLP)와 유효선량 평가 결과를 기록, 보관하고 있으며, 이러한 정보들은 환자들의 방사선 노출 및 위험도를 평가하는 데 필수적이다. 방사선 노출 위험도를 감소시키기 위해서 적정화 및 정당화 원칙을 반드시 준수해야 한다. 관전압(kV)에 따른 TCM 방식을 사용하였을 경우 kV가 낮아질수록 유효선량이 낮아지는 경향을 나타내었으며, low dose CT protocol을 사용한 경우가 유효선량이 상대적으로 더 적은 것을 알 수 있었다. 또한 평균 유효선량은 brain, chest, abdomen-pelvis CT의 결과가 독일의 reference dose 보다 각각 47%, 13.8%, 25.7%로 더 낮게 나타났고. 영국의 reference dose와 비교해도 55.7%, 10.2%, 43.6%에 불과했다. 결론적으로 선량 감소를 위해 주의할 것은 body-weight based tube current adaption을 포함한 TCM, 그리고 LDCTP 등 모든 선량 감소 방안을 이용하여야 한다.

브로거 운동을 병행한 산전운동프로그램이 임산부의 허리 통증 및 균형에 미치는 영향 단일 사례 연구 (Effect of prenatal exercise program combined with Brugger's exercise on low back pain and balance in pregnant women: A single-subject study)

  • 김선민;장상훈
    • 대한물리치료과학회지
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    • 제28권1호
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    • pp.85-96
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    • 2021
  • Background: The purpose of this study was to effect of prenatal exercise program combined with Brugger's exercise on low back pain and balance in pregnant women. Design: A Single-Subject Study. Methods: This study was applied to 28 weeks of pregnant women who complained of low back pain for a total of 4 weeks. A total of 10 prenatal exercise programs in this study consists of sessions, and each session was applied with a Bruger exercise for 1 minute before the start. For the fatigue and safety of pregnant women, a break for 1 minute was provided for each session and was conducted under the supervision of the therapist The visual analogue scale (VAS), Oswestry disability index (ODI), and static balance (BT-4) were measured to evaluate the pregnant women's low back pain and balance ability before and after the intervention Results: The change in back pain after the intervention was VAS 5 before the intervention, but the VAS gradually decreased at 4 weeks after the intervention. Reduced to VAS 2 after 4 weeks of intervention. The Oswestry Disability Index (ODI) was 54%, which was at the level of severe disability, but the dysfunction index gradually decreased 4 weeks after intervention, reaching 19% in 4 weeks, and there were no problems with daily life. As for the static balance ability, the sway area and the sway distance values gradually decreased after the intervention in both the eyes open and closed state, showing an improvement in the static balance ability of pregnant women after the intervention than before the intervention. Conclusion: The prenatal exercise program combined with Brugger's exercise was effective to improve low back pain and static balance in pregnant women. The result of this study may helpful as basic data for obstetric physical therapy.