• 제목/요약/키워드: Changes in the position of the moon

검색결과 82건 처리시간 0.027초

Spectral-shape-controllable Chirped Fiber Bragg Grating with a Photomechanical Microactuator: Simulation and Experiment

  • Moon, Jong-Ju;Ko, Youngmin;Park, Su-Jeong;Ahn, Tae-Jung
    • Current Optics and Photonics
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    • 제4권6호
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    • pp.477-482
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    • 2020
  • Recently, one of the authors has been reported an optically tunable fiber Bragg grating (FBG) with a photomechanical polymer. It was based on a typical FBG with a downsized diameter of 60 ㎛, coated with azobenzene-containing polymer material. Azobenzene is a well-known reversibly photomechanical stretchable material under ultraviolet (UV) light. The small part of the functional-coating region on the FBG absorbed UV light, which pulled the UV-exposed part of the grating. It was selectable as tunable FBG or tunable chirped FBG, by adjusting the position of UV exposure on the grating. As proof of concept for the tunable FBG device, the characteristics just including UV-induced center-wavelength shift and spectral-width changes of the device were reported. In this paper, we report for the first time that the microactuator makes it possible to control the spectral shape of the FBG reflection, according to the specifications (shape and intensity) of the UV beam that reaches the FBG coated with the azobenzene polymer. In addition, we provide the group-delay profiles for the chirped FBG, so that the sign of its dispersion (normal or anomalous) can be tailored by simply selecting the moving direction of the UV light's displacement in the experiment.

도시철도 구내정보통신 기반설비 표준화 및 기능 향상방안 (Metro Telecommunication Basis Facilities Standardization and Functional Improvement Research)

  • 김문태;윤인영
    • 한국철도학회:학술대회논문집
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    • 한국철도학회 2005년도 추계학술대회 논문집
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    • pp.964-968
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    • 2005
  • The standardization of information communication is doing a Internal each other connection and each other characteristic stability operation security in objective. From the low-speed network of the subway operation beginning currently it changes with the superhigh speed digital information transmission communication service environment which is a quality service, the hazard which plans the quality improvement of the efficient communication service use which hits to here and passenger service the standardization of the technical standard which stands and the improvement which hits to an engineering standard and facility must come to accomplish. The facility which existing is been old or the enclosure communication equipments which are insufficient. it improves, establishment itexpands efficiently, like this facilities it is stabilized and it is economic and rationally use maintenance it manages with the plan for the inside and outside of the country information communication relation technical standard and engineering standard service feature improvement and future expandability and economical efficiency, the possibility of having a pliability in order to be, rational technical standard and standard it takes a triangular position, efficient characteristic security of information communication service there is a place objective which promises the rational development of course city railroad communication system with character. Function improvement of enclosure communication base equipment, against an improvement and standardization plan it described trom the prosecution which it sees.

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무지외반증에 대한 근위 갈매기형 절골술 시행 후 임상적 및 방사선학적 결과는 언제 안정화되는가? (When Do Clinical and Radiographic Results Stabilize after Proximal Chevron Osteotomy in Hallux Valgus?)

  • 박철현;이우천;박재우;문정재
    • 대한족부족관절학회지
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    • 제19권3호
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    • pp.91-96
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    • 2015
  • Purpose: The purpose of this study is to evaluate the sequential changes of clinical and radiographic results after proximal chevron osteotomy in patients with moderate to severe hallux valgus. Materials and Methods: Between January 2008 and December 2009, 93 patients (117 feet) were treated with proximal chevron osteotomy and distal soft tissue procedure for symptomatic moderate to severe hallux valgus deformity. The mean age of patients was 51 years (range, 19 to 71) and the mean duration of follow-up was 27.5 months (range, 24 to 35). Clinical results were evaluated using visual analogue scale (VAS) and American Orthopaedic Foot and Ankle Society (AOFAS) score preoperatively, at 3, 6, and 12 months after surgery, and at the last follow-up. Radiographic parameters including hallux valgus angle, intermetatarsal angle, and sesamoid position were evaluated preoperatively, immediately postoperatively, at 6 weeks, at 3, 6, and 12 months after surgery, and at the last follow-up. Results: VAS and AOFAS score showed significant improvement until 12 months after surgery. Hallux valgus angle and sesamoid position stabilized at 12 months after surgery and intermetatarsal angle stabilized at 6 months after surgery. Conclusion: Clinical and radiographic results were stabilized beyond 12 months after proximal chevron osteotomy in patients with moderate to severe hallux valgus.

다중 퍼지제어기를 이용한 유도전동기의 직접 토크제어 (Direct Touque Control of Induction Motor Using Multi Fuzzy Controller)

  • 문주희;고재섭;최정식;강성준;장미금;백정우;정동화
    • 전력전자학회:학술대회논문집
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    • 전력전자학회 2010년도 하계학술대회 논문집
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    • pp.585-586
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    • 2010
  • An induction motor operated with a conventional direct self controller(DSC) shows a sluggish response during startup and under changes of torque command. Fuzzy logic controller(FLC) is used in conjunction with DSC to minimize these problems. A FLC chooses the switching states based on a set of fuzzy variables. Flux position, error in flux magnitude and error in torque are used as fuzzy state variables. Fuzzy rules are determinated by observing the vector diagram of flux and currents. This paper proposes hybrid FLC for direct torque control(DTC) of induction motor drives. This controller is controlled speed using hybrid FLC. The performance of the proposed induction motor drive with hybrid FLC is verified by analysis results at various operation conditions.

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Comparison of Abdominal Muscle Thickness Using Ultrasound Imaging During Bridging Exercises With a Sling and Ball in Healthy Young Adults

  • Moon, Young;Choi, Jong-duk
    • 한국전문물리치료학회지
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    • 제27권1호
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    • pp.87-92
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    • 2020
  • Background: Bridging exercises are used to enhance the functional stability of the lumbopelvic region in clinical settings. Although most of the studies on bridging exercises have compared the complete activation of the trunk muscles, some recent studies have examined the functional stability of the trunk and the lumbopelvic region and assessed the appropriate recruitment of the local and global muscles during different task levels. Objects: The purpose of this study was to investigate the changes in muscle thickness in the transverse abdominis (TrA), internal oblique (IO), and external oblique (EO) muscles during a common bridging exercise on an unstable surface and to determine whether these changes differ based on the surface used. Methods: Twenty-five healthy young adults (8 males, 17 females) were recruited. The subjects were randomly assigned to either the exercise progression with a sling bridge group or the ball bridging exercise progression group, each with three stages of increasing difficulty. Each position was measured three times with an ultrasonic diagnostic imaging system, and the mean values were recorded for analysis. Results: No significant differences were observed between the TrA, IO, or EO muscle thickness ratios between the sling and ball exercise groups (p > 0.05). There were also no significant differences in the EO muscle thickness ratios between the tasks irrespective of whether the sling or ball was used. However, the TrA and IO thickness ratios in both groups were significantly greater during stages 2 and 3 compared to stage 1. Conclusion: The results suggest that the use of slings and balls during bridging exercises is effective in activating the deep abdominal muscles.

이전 k 개의 가장 가까운 이웃을 이용한 무리 짓기에 대한 공간분할 방법의 개선 (An Improvement Of Spatial Partitioning Method For Flocking Behaviors By Using Previous k-Nearest Neighbors)

  • 이재문
    • 한국게임학회 논문지
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    • 제9권2호
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    • pp.115-123
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    • 2009
  • 논문에서는 무리 짓기에 대한 공간분할 방법의 성능을 개선하는 알고리즘을 제안한다. 핵심 개념은 무리 속에서 움직이는 개체인 보이드가 지속적으로 자신의 방향과 위치를 변경시키나 자신의 다음 방향의 결정에 영향을 주는 k개의 가장 가까운 이웃인 kNN은 자주 바뀌지 않는다는 사실을 이용하여 성능을 개선하는 것이다. 본 논문에서 이전의 kNN을 이용하여 새로운 kNN이 변경되었는지를 판별하는 방법이 제안되었고, 제안된 방법의 정당성은 정리를 통하여 증명되었다. 제안된 방법은 구현되었으며, 기존의 공간분할 방법과 성능이 비교되었다. 비교 결과로부터 제안된 알고리즘이 초당 프레임 수 관점에서 기존의 알고리즘보다 약 30% 개선 효과를 주는 것을 알 수 있었다.

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정상 여성에게서 앞 정강근의 수축훈련방법에 따른 뇌파의 변화 (Changes of Electroencephalogram according to Contraction Training Methods of Tibialis Anterior Muscle in Healthy Women)

  • 이정우;김문정;윤세원
    • The Journal of Korean Physical Therapy
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    • 제24권2호
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    • pp.127-133
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    • 2012
  • Purpose: This study aims to examine the power changes in eletrocenphalogram (EEG) detected from the tibialis anterior muscle, during repetitive contraction exercise in normal female adults. Methods: The subjects of this study were 24 normal adult females, with no musculoskeletal or nervous system disorders. The 24 female subjects were divided into two groups: 12 subjects comprised a voluntary stimulation training group, and the other 12 subjects comprised an electrical stimulation training group. A total of thirty contractions were made repetitively by each woman, with maximal voluntary contraction exercise for six seconds, and a resting time of three seconds. During the experiment, their EEG was measured at eight positions. The eight positions were Fpz, Fz, Cz, CPz, C3, C4, P3, and P4, in accordance with the international 10~20 system. Results: The relative alpha power and beta power showed no statistically significant differences between the two groups. But the relative gamma power of the CPz, C3, C4, P3, and P4 areas showed statistically significant differences between the two groups (p<0.05). The relative theta power of the C4 area showed statistically significant differences between the two groups (p<0.05). Conclusion: Our findings show that tibialis anterior muscle contraction by electrical stimulation and by voluntary repeated contraction differentially affected brain activation. In particular, the CPz, C3, C4, P3 positions of relative gamma power showed brain activation in voluntary contraction. The C4 position of relative theta power showed different brain activation between the two groups.

이동로봇의 불확실성을 고려한 안정한 시각 랜드마크의 자동 추출 (Automatic Extraction of Stable Visual Landmarks for a Mobile Robot under Uncertainty)

  • 문인혁
    • 제어로봇시스템학회논문지
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    • 제7권9호
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    • pp.758-765
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    • 2001
  • 본 논문에서는 랜드마트 정보 없이 장해물의 위치 정도 지도만 주어졌을 때 스테레오 시작(stereo vision)을 가진 이동로봇이 관측위치와 조명의 변화에도 강인한 시각 특징을 랜드마크로써 추출하는 수법을 제안한다. 장해물의편평한 면사에서 보다 안쪽영역에 존재하는 특징이 관측위치의 변화에 영향을 덜 받기 때문에 안쪽 영역에 존재하는 수직선 세그먼트(vertical line segment) 특징을 랜드마크로 선택한다. 그러나 선택된 특징에서는 로봇의 이동과 관측이 오차에 의해 불확실성(uncertainty)이 포함되어 있기 때문에 추정해야만 한다. 이를 위해 영역기반 스테레오 정합과 특징기반 스테레오 정합법을 이용하여 정합된 특징을 선택하고 확장 칼만필터(Extended Kalman Filter)를 이용여 선택된 특징의 위치, 길이를 추정하여 랜드마크로써 등록한다. 실내 이동환경에서의 실험을 통해 제안된 수법의 유용성을 보인다.

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다래(Actinidia arguta) 및 교잡종 다래(A. arguta × A. deliciosa)의 수관층위에 따른 광합성, 엽 그리고 과실의 특성 변화 (Changes of Photosynthesis, Leaf and Fruit Characteristics of Actinidia arguta and Hybrid Kiwi (A. arguta × A. deliciosa) According to Crown Layer)

  • 박영기;한진규;황석인;김세현;강문수
    • 한국산림과학회지
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    • 제100권1호
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    • pp.8-13
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    • 2011
  • 본 연구는 다래 및 교잡종 다래의 수관층위에 따른 광환경 차이에 따른 광합성능력, 엽 그리고 과실의 특성 변화를 구명하고자 실시하였다. 수관층위별에 따른 광합성속도를 측정한 결과, 수관층위가 높아질수록 광합성 속도가 증가하여 광도 $1,000{\mu}mol{\cdot}m^{-2}s^{-1}$에서 하층($5.82{\mu}mol\;CO_2\;m^{-2}s^{-1}$), 중층($7.11{\mu}mol\;CO_2\;m^{-2}s^{-1}$), 상층($9.54{\mu}mol\;CO_2\;m^{-2}s^{-1}$)의 순으로 높은 광합성속도를 나타냈다. 엽의 경우, 수관층위가 높아질수록 엽폭과 엽장 그리고 엽면적이 감소하였다. 즉, 하층, 중층, 상층 수관층위가 증가할수록 엽면적은 162.8, 90.9, $68.3cm^2$ 로 각각 감소하였다. 과실의 경우에는 수관층위가 높아질수록 과실 중량 및 과실 폭과 과실 길이가 증가하는 경향을 나타냈다. 이러한 결과는 상층의 높은 광합성능력이 과실의 생육에 영향을 미친 것으로 수관상층부로의 결과지 유도를 통해 대립성 다래 과실생산이 가능할 것으로 여겨진다.

평류안뜰자극이 자율신경성 반응에 미치는 영향 (The Effect of Galvanic Vestibular Stimulation on Autonomic Nervous System Response)

  • 문화영;강솔;김화성;허소영;손유리;이정우
    • 대한임상전기생리학회지
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    • 제8권2호
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    • pp.19-24
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    • 2010
  • Purpose : This study aims to examine the influences of galvanic vestibular stimulation on autonomic reaction of normal adults. Methods : Participants in this research totaled 28 (14 men and 14 women). Galvanic vestibular stimulation was conducted with a binaural electrode configuration for 60 sec. Galvanic vestibular stimulation measurements were conducted with the subjects in a prone position. Measured items included skin conductance, blood flow, pulse rate, and respiratory rate. Measurements were repeated for a total of five times, before application, during application, after application, 5 minutes after application and 10 minutes after application. Results : Skin conductance reaction showed statistically significant differences in changes depending on time after galvanic vestibular stimulation and there were statistically differences in changes of blood flow, pulse rate and respiratory rate after galvanic vestibular stimulation. Conclusion : Blood flow, pulse rate and respiratory rate of autonomic reactions were not influenced by galvanic vestibular stimulation, but skin conductance reaction was influenced by it and it was found that it was reduced during and after stimulation rather than before stimulation. Consequently, it was considered that galvanic vestibular stimulation affected the autonomic reaction.