• 제목/요약/키워드: Symmetrical

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일 강우량 및 기온 자료의 모의를 위한 GCM 모형의 평가 (Simulation Assessment of GCM Model in Case of Daily Precipitation and Temperature)

  • 손민우;변지선
    • 한국수자원학회:학술대회논문집
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    • 한국수자원학회 2019년도 학술발표회
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    • pp.307-307
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    • 2019
  • General Ciculation Model (GCM) 모형에 대한 평가를 본 연구에서 수행한다. 모형의 적용을 위해서는 국지적 일 강우량 및 기온자료를 이용한다. 31개의 GCM 모의를 통해 도출되는 결과가 성능 평가에서 활용되었다. 일 최대, 최소 기온와 강우량이 파키스탄 지역을 대상으로 모의되었다. 모의를 위해서는 Gridded 데이터가 적용되었으며 각각 Asian Precipitation-Highly-Resolved Observational Data Integration Toward Evaluation, Berkeley Earth Surface Temperature, Princeton Global Meteorological Forcing, Climate Prediction Centre에 해당된다. GCM의 순위를 결정하기 위해서는 Symmetrical Uncertainty 방법이 이용된다. 결과를 통해서 Gridded 데이터의 종류에 따라 가장 높은 효율을 나타내는 GCM의 공간 분포가 달라진다는 점을 확인하였다. 이러한 특성은 기온과 강우량 자료 모두에서 확인된다. 기온의 경우에는 Commonwealth Scientific and Industrial Research Organization, Australia-MK3-6-0과 Max Planck Institute-ESM-LR이 우수한 결과를 모의하는 것으로 나타났다. 반면 강우량의 경우에는 EC-Earth와 MIROC가 우수한 것으로 나타났다. 파키스탄 지역에서의 기온 및 강우량 자료의 합리적 반영을 위해서는 ACCESS1-3, CESM1-BGC, CMCC-CM, HadGEM2-CC, HadGEM2-ES, MIRCO5와 같은 6개 GCM을 이용하였을 때 다양한 기상 인자를 고려한 모의가 가능한 것으로 평가된다.

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First Korean Record of Porcellanopagurus japonicus (Decapoda: Paguroidea), a Hermit Crab Living in Bivalve Shells

  • Jung, Jibom;Lee, Sang-Hui
    • Animal Systematics, Evolution and Diversity
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    • 제36권4호
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    • pp.391-395
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    • 2020
  • This study reports the pagurid hermit crab Porcellanopagurus japonicus in Korean waters for the first time. This species has a right cheliped larger than the left one, reduced and globular abdomen, and symmetrical uropods. Porcellanopagurus japonicus is similar to P. nihonkaiensis, a previously reported congeneric species in Korea, but also has distinguished morphological and ecological characters. There are currently issues with the Korean scientific name for P. japonicus, we suggest a reasonable Korean scientific name of this organism with its etymology. In addition, this species inhabits bivalve shells, which is not a typical habitat for hermit crabs, and the unique habitats of this and several other Korean hermit crabs are reviewed.

일반인과 뇌졸중 편마비 환자의 연령별 선 자세에서 눕기 시 동작유형의 비교 (Movement Patterns for Lying from Erect Stance to Supine Position of Healthy Adults and Hemiplegia Patients Aged from 50 to 70)

  • 전춘배;김상진;김중선
    • The Journal of Korean Physical Therapy
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    • 제23권5호
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    • pp.7-14
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    • 2011
  • Purpose: The purpose of this study was to describe the movement patterns when lying from an erect stance to a supine position of healthy adults and hemiplegia patients in the age group from 50 to 70. Methods: The subjects used in this study were 230 patients (144 healthy adults and 86 hemiplegia patients). Movement patterns were classified using categorical descriptions of the action of three body regions: the upper extremity, lower extremity, and the head-trunk region. Results: In the most common supine lying position in healthy adults (29.7%), the female fifties age group performed a symmetrical pattern using the upper extremity region, a symmetrical squat pattern using the lower extremity region, and a symmetrical pattern using the head-trunk region (1-1-1). However, in the most supine lying position in hemiplegia patients (32.0%), the female sixties age group usually performed this pattern by using the upper extremity and lower extremity regions in a squat position by raising the leg, and performing rotation of the head-trunk region (3-4-3). Conclusion: Using this clinical therapy, and considering the patients ability to exercise when lying from an erect stance to a supine position, the proper care could be provided. Moreover, this therapy introduces action based on a variety of training methods and on the effects which might result from any changes.

Seismic response of active or semi active control for irregular buildings based on eigenvalues modification

  • Pnevmatikos, Nikos G.;Hatzigeorgiou, George D.
    • Earthquakes and Structures
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    • 제6권6호
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    • pp.647-664
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    • 2014
  • A reduction of the response of irregular structures subjected to earthquake excitation by control devices equipped by suitable control algorithm is proposed in this paper. The control algorithm, which is used, is the pole placement one. A requirement of successful application of pole placement algorithm is a definition-selection of suitable poles (eigen-values) of controlled irregular structures. Based on these poles, the required action is calculated and applied to the irregular structure by means of control devices. The selection of poles of controlled irregular structure, is a critical issue for the success of the algorithm. The calculation of suitable poles of controlled irregular structure is proposed herein by the following procedure: a fictitious symmetrical structure is considered from the irregular structure, adding vertical elements, such as columns or shear walls, at any location where is necessary. Then, the eigen-values of symmetrical structure are calculated, and are forced to be the poles of irregular controlled structure. Based on these poles and additional damping, the new poles of the controlled irregular structure are calculated. By pole placement algorithm, the feedback matrix is obtained. Using this feedback matrix, control forces are calculated at any time during the earthquake, and are applied to the irregular structure by the control devices. This procedure results in making the controlled irregular structure to behave like a symmetrical one. This control strategy can be applied to one storey or to multi-storey irregular buildings. Furthermore, the numerical results were shown that with small amount of control force, a sufficient reduction of the response of irregular buildings is achieved.

순시적인 전압 sag 보상기에 대한 제어 알고리즘의 해석 (Analysis of Control Algorithm for Instantaneous Voltage Sag Corrector)

  • 이상훈;김재식;최재호
    • 전력전자학회논문지
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    • 제6권2호
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    • pp.173-179
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    • 2001
  • 본 논문은 배전계통의 전력품질 개선을 위한 순시 전압강하 보상기의 제어 알고리즘에 대한 연구를 수행하였다. 특별히 순시적인 전압강하의 원인중 가장 대표적인 1선 지락사고 시에 발생하는 불평형과 비대칭 문제를 해석하기 위하여 새로운 대칭성분 검출 기법을 제안하였다. 제안되 방법은 간단한 연산만을 사용하며, 전압보상을 위한 대칭성분의 제어 기준값이 별도의 위상검출 과정을 거치지 않고도 직류 값으로 표현되도록 하였다. 그리고 기준전압의 발생 시에 IEC에서 규정하고 있는 UF와 MF를 사용하도록 하였다. 제안된 제어기법을 사용하면 보상장치는 매우 빠른 응답특성을 가지고 보상된 전압 파형의 총고조파왜형률(THD)도 매우 낮게 된다. 마지막으로 EMTDC 시뮬레이션과 실험을 통하여 제안된 방법의 타당성을 입증하였다.

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포화를 방지하기 위한 보호용 철심 변류기 설계 방법 (A Design Method of Iron-cored CTs To Prevent Satruation)

  • 이주훈;강상희;강용철;이승재;배주천;안준기;이청학;이정택
    • 대한전기학회논문지:전력기술부문A
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    • 제48권2호
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    • pp.119-126
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    • 1999
  • Current transformer (CT) saturation may cause a variety of protective relays to malfunction. The conventional CT is designed that it can carry up to 20 times the rated current without exceeding 10% ratio error. However, the possibility of CT saturation still remains if the fault current contains substantial amounts of ac and/or dc components. This paper presents a design method of iron-cored CTs for use with protective relays to prevent CT saturation. The proposed design method determines the core cross section of the CT; it employs the transient dimensioning factor to consider relay's operating time (duty cycle) and dc component as well as ac components contained in the fault current, and symmetrical short-circuit current factor to consider as well as ac components contained in the fault current, and symmetrical short-circuit current factor to consider the biggest fault current. The method designs the cross section of CTs in cases of reclosure and no reclosure.

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OPTIMUM MANDIBULAR POSITION GUIDE BY USE OF EMG ACTIVITY AND INTRA-ORAL TRACER

  • Lee Seung-Ho;Kang Dong-Wan
    • 대한치과보철학회지
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    • 제40권6호
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    • pp.560-571
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    • 2002
  • Jaw relations and the recording methods have been controversial aspects of dentistry. The purpose of this study was to quantify the relative muscle activity of the masseter and temporal muscles in relation to different intermaxillary relations recorded by intra-oral tracer during maximal clenching and to decide the optimal mandibular position. Ten volunteers with healthy TMJ were studied. Intra-oral tracer was assembled and bite block was fabricated in the articulator. Intra-oral tracer was placed in the mouth, and four mandibular positions were recorded. EMG activity was recorded on a BIO-PAK system (Bio-Research Associates, Inc. USA.) in masseter and temporal muscle and compared in each mandibular positions. The results were as follows: 1. In comparison with maximum intercuspation, the chewing position was the most similar followed by tapping position, myocentric position and posterior border position. However the differences were not statistically significant. 2. In comparison of bilateral symmetry of masseter muscle, tapping position was the most symmetrical followed by chewing position and maximum intercuspation. Myocentric position and posterior border position were not symmetrical. (P<.05). 3. In comparison of bilateral symmetry of anterior temporal muscle, chewing position was the most symmetrical followed by posterior border position, maximum intercuspation, myocentric position and tapping position. However the differences were not statistically significant. 4. In comparison of proportionality of anterior temporal muscle to masseter muscle activity on left side, posterior border position was the greatest followed by myocentric position, taping position, chewing position and maximum intercuspation. And the proportionality of posterior border position was greater than that of maximum intercuspation. (P<.05). 5. In comparison of proportionality of anterior temporal muscle to masseter muscle activity on right side, myocentric position was the greatest followed by posterior border position, tapping position, maximum intercuspation and chewing position. However the differences were not statistically significant.