• 제목/요약/키워드: Short axis

검색결과 343건 처리시간 0.033초

Shape model and spin state of non-principal axis rotator (5247) Krylov

  • Lee, Hee-Jae;Durech, Josef;Kim, Myung-Jin;Moon, Hong-Kyu;Kim, Chun-Hwey
    • 천문학회보
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    • 제44권2호
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    • pp.45.2-45.2
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    • 2019
  • The main-belt asteroid (5247) Krylov is known as a Non-Principal Axis (NPA) rotator. However, the shape model and spin state of this asteroid were not revealed. The physical model of an asteroid including spin state and shape is regarded to be important to understand its physical properties and dynamical evolution. Thus, in order to reconstruct the physical model of Kryolv, we applied the light curve inversion method using not only the optical light curves observed with ground-based telescopes in three apparitions during 2006, 2016, and 2017, but also the infrared light curves obtained with the Wide-field Infrared Survey Explorer (WISE) in 2010. We found that it is rotating in Short Axis Mode (SAM) with the rotation and precession periods of 368.71 hr and 67.277 hr, respectively. The orientation of the angular momentum vector is (298°, -58°) in the ecliptic coordinate system. The ratio of moments of inertia of the longest axis to the shortest axis is Ia/Ic = 0.36; the ratio of moments of inertia of the intermediate axis to the shortest axis is Ib/Ic = 0.96. Finally, the excitation level of this asteroid is found to be rather low with a ratio of the rotational kinetic energy to the basic spin state energy as E/E0 ≃ 1.024. We will briefly discuss the possible evolutionary process of Krylov in this presentation.

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통기성 상자 구조물에 대한 유한요소 해석 (Finite Element Analysis of a Ventilating Box Structure)

  • 박종민;권순구
    • Journal of Biosystems Engineering
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    • 제27권6호
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    • pp.557-564
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    • 2002
  • Corrugated board is an efficient low-cost structure material fur the boxes that are widely used for transporting, storing and distributing goods. Corrugated board is also considered as an orthotropic because the principal material directions are the same as in paperboard. The purpose of this study was to elucidate the principal design parameters of ventilating box through the FEA on the various types of ventilating hole. From the viewpoint of the stress distribution and stress level, the optimum pattern and location of the ventilating hole were vertically oblong, and symmetry position with a short distance to the right and left from the center of front and rear panel. And, the optimum location and pattern of hand hole were a short distance to the top from the center of both side panels, and modified shape to increase the radius of curvature of both side in horizontal oblong. In general, the optimum pattern and location of both the ventilating hole and hand hole based on the FEM analysis were well verified by experimental investigation. It is suggested that decrease in compressive strength of the box could be minimized in the same ventilating hole area under the condition of the length of major axis of ventilating hole is less than 1/4 of box length, the ratio of minor axis/major axis is 113.5∼l/2.5, and number of the ventilating holes is even and symmetrical.

B 모드 단축 심초음파 영상의 좌심실 내벽 윤곽선 자동 검출 (Automatic Detection of Left Ventricular Endocardial Boundary on B-mode Short Axis Echocardiography)

  • 김명남;원철호;조진호
    • 전자공학회논문지B
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    • 제32B권10호
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    • pp.1294-1304
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    • 1995
  • In this paper, a method has been proposed for the fully automatic detection of left ventricular endocardial boundary in B-mode short axis echocardiography without manual intervention by human operator. The proposed method makes use of the weighted model that approximates to endocardium and incomplete edge information for echocardiography. Therefore, this method is more effective than boundary detection by only edge information. The implementation of this method is as follows. First, the proposed algorithms are used in order to detect the approximate boundary, then a weighted model with the approximate boundary is constructed. Finally, the cavity center of the left ventricle performing the Hough transform with the weighted model and edge image can be found automatically, and then the endocardial boundary using detected center, original image, weighted model, and edge image can be detected. validations of this method with experimental results on echo image of dog's heart and clinical echocardiography is verified.

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유도전동기의 권선 단락 상에 따른 팍스 벡터 패턴 왜곡률의 영향 해석 (Interpretation of Influence Winding Short Phase of Induction Motor to Distortion Ratio of Park's Vector Pattern)

  • 양철오;김종선;김준영;박규남;송명현
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2011년도 제42회 하계학술대회
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    • pp.2075-2076
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    • 2011
  • The stator winding faults diagnosis technique based on MCSA is as follows. Firstly, collecting the 3 phase motor currents, that signal is transformed by (d-q transform, $i_d$, $i_q$). Park's vector pattern, the circle that is down by d-q transformed currents($i_d$, $i_q$). The circle is widely used for stator winding faults detection. The current distortion ratio(DR), defined by the ratio of max-axis and min-axis of ellipse of Park's vector's pattern. In this study, distortion ratio of Park's vector pattern is suggested for Auto diagnosis of stator winding short fault and usefulness of distortion ratio is verified through simulation using LabVIEW program.

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틸트제어를 위한 하이브리드형 광픽업 구동기에 대한 연구 (Study on Hybrid type Optical Pickup Actuator for Tilt Control)

  • 김철진;이경택;신창훈;박노철;박영필
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2002년도 추계학술대회논문집
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    • pp.782-787
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    • 2002
  • In optical disk drives (ODD), the demands of high data density and high speed have been increasing rapidly to achieve high data capacity and data transfer rate. The short wavelength laser, High NA objective lens, and high track following performance are needed to raise data density and data rate. For high-performance actuator, the improvement of linearity and acceleration become more important. Also, 3-axis actuator for active tilt compensation is introduced to overcome the decrease in disk tilt tolerance which is induced by short wavelength laser. In this paper, a hybrid type 3-axis actuator is presented and a new yoke structure, which can reduce the interaction between yoke and moving magnet, is designed to keep the efficiency of magnetic circuit. Experimental results show the validity of the yoke in the hybrid type actuator.

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개심장사상충 중감염에 따른 심실중격기이운동과 대정맥증후군의 심장초음파상 (Echocardiograpical Findings of Heartworm Disease with Paradoxic septum motion and Caval Syndrome in a Pug Dog)

  • 박인철
    • 한국임상수의학회지
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    • 제18권3호
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    • pp.297-303
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    • 2001
  • A female pug was presented with severe anemia, dyspnea and hemoglobinuria. By B- and M-mode echocardiography, the large number of heartworm were founded in the right ventricle, right atrium and pulmonary artery. The heartworm mass was moved from the right ventricle to the right atrium with the motion of the tricuspid value. Paradoxic septum motion were visible in M-mode of left ventrcular outflow tract and chordae tendineae level short-axis view. Flattened interventricular septum was find in B-mode of papillary muscle level short-axis view. In autopsy, 81 adult heartworms and 7 filarial debris were found. Most of adult heartworm were found in the right ventricle and pulmonary artery. 3 of them were found in the venaca and right atrium, respectively.

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AFLC의 배열특성에 관한 연구 (Aligning properties of antiferroelectric liquid crystals (AFLC))

  • 강진우;박원상;최덕운;구경상;황용석;이서헌;이기동;윤태훈;김재창
    • 한국광학회지
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    • 제12권5호
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    • pp.414-417
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    • 2001
  • Experimentally, the aligned direction of AFLCs in electro-optic cells having both the substrates rubbed along the same direction is skewed by a few degrees from the rebbing direction. To explain why, we proposed "Torsional Rigid Body Model" and interpreted their skewing angle as the action of short pitch with the large shear stress. That is, the azimuthal an anchoring strength (about 35 dyn/cm) in the cell is much larger than the maximum shear stress (about 10$^{-6}$ dyn/cm) for the original pitch and so forbids the optic axis to skew. On the side hand, the strength is smaller than the maximum shear stress (about 42 dyn/cm) for short pitch and then allows the optic axis to skew.

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Dpp Represses eagle Expression at Short-Range, but Can Repress Its Expression at a Long-Range via EGFR Signal Repression

  • Kim, Se Young;Jung, Keuk Il;Kim, Sang Hee;Jeon, Sang-Hak
    • Molecules and Cells
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    • 제26권6호
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    • pp.576-582
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    • 2008
  • Nervous system development takes place after positional information has been established along the dorsal-ventral (D/V) axis. The initial subdivision provided by a gradient of nuclear dorsal protein is maintained by the zygotic genes expressed along the D/V axis. In this study, an investigation was conducted to determine the range of Dpp function in repressing the expression of eagle (eg) that is present in intermediate neuroblasts defective (ind) and muscle specific homeobox (msh) gene domain. eg is expressed in neuroblast (NB) 2-4, 3-3 and 6-4 of the msh domain, and NB7-3 of the ind domain at the embryonic stage 11. In decapentaplegic (dpp) loss-of-function mutant embryos, eg was ectopically expressed in the dorsal region, while in dpp gain-of-function mutants produced by sog or sca-GAL4/UAS-dpp, eg was repressed by Dpp. It is worthy of note that Dpp produced from sim;;dpp embryos showed that Dpp could function at long range. However, Dpp produced from en-GAL4/UAS-dpp or wg-GAL4/UAS-dpp primarily acted at short-range. This result demonstrated that this discrepancy seems to be due to the repression of Dpp to EGFR signaling in sim;;dpp embryos. Taken together, these results suggest that Dpp signaling works at short-range, but can function indirectly at long-range by way of repression of EGFR signaling during embryonic neurogenesis.

3축 가속 센서의 가공 파라미터를 장단기 메모리에 적용한 낙상감지 시스템 연구 (Study of the Fall Detection System Applying the Parameters Claculated from the 3-axis Acceleration Sensor to Long Short-term Memory)

  • 정승수;김남호;유윤섭
    • 한국정보통신학회:학술대회논문집
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    • 한국정보통신학회 2021년도 추계학술대회
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    • pp.391-393
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    • 2021
  • 본 논문에서는 일상생활에서의 고령자에게 나타날 수 있는 낙상상황을 감지할 수 있는 텐서플로우를 이용한 장단기 메모리 기반 낙상감지 시스템에 대하여 소개한다. 낙상감지를 위해서 3축 가속도 센서 데이터를 이용하고, 이를 처리하여 다양한 파라미터화하며 일상생활 패턴 4가지, 낙상상황 패턴 3가지로 분류한다. 파라미터화한 데이터는 정규화 과정을 따르며, 학습이 진행된다. 학습은 Loss값이 0.5 이하가 될 때까지 진행된다. 각각의 파라미터인 θ, SVM (Sum Vector Magnitude), GSVM (gravity-weight SVM)에 대하여 결과를 산출한다. 가장 좋은 결과는 GSVM으로 Sensitivity 98.75%, Specificity 99.68%, Accuracy 99.28%로 가장 좋은 결과를 보였다.

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