• 제목/요약/키워드: Nodal

검색결과 1,243건 처리시간 0.03초

전압 강하 협조 그래프(VSCC)를 이용한 수용가 모선 가격 계산 (Customer Nodal Cost Calculation using Voltage Sag Coordination Charts)

  • 정성원;이현철;이근준;김재현
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2008년도 제39회 하계학술대회
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    • pp.298-299
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    • 2008
  • In this paper, supposed that can measure power quality of bus and can calculate this cost in case electric charges about customer are imposed by each bus. When reflected this in system planning, expected cost proposed following method through sample system. We calculated the nodal cost by OPF(optimal power flow) in system and the drop numbers that happen during year of loads utilizing VSCC. Also calculated BPQC using the disruption numbers. As a result, calculated bus total cost including power quality cost through case study.

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Matching of Physical Experiments and Multibody Dynamic Simulation for Large Deformation Problems

  • Yoo, Wan-Suk;Lee, Jeong-Han;Sohn, Jeong-Hyun;Park, Su-Jin;Oleg Dmitrochenko;Dmitri Pogorelov
    • Journal of Mechanical Science and Technology
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    • 제18권5호
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    • pp.742-752
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    • 2004
  • Many papers have studied computer simulations of elastic bodies undergoing large deflections and large deformations. But there have not been many attempts to check the validity of the numerical formulations because the simulation results could not be matched without correct input data such as material properties and damping effects. In this paper, these values are obtained from real experiment with a high-speed camera and a data acquisition system. The simulation results with the absolute nodal coordinate formulation (ANCF) are compared with the results of real experiments. Two examples, a thin cantilevers beam and a thin plate, are studied to verify whether the simulation results are well matched to experimental results.

SIMP 기반 절점밀도법에 의한 3 차원 위상최적화 (3-D Topology Optimization by a Nodal Density Method Based on a SIMP Algorithm)

  • 김철;팡난
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2008년도 추계학술대회A
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    • pp.412-417
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    • 2008
  • In a traditional topology optimization method, material properties are usually distributed by finite element density and visualized by a gray level image. The distribution method based on element density is adequate for a great mass of 2-D topology optimization problems. However, when it is used for 3-D topology optimization, it is always difficult to obtain a smooth model representation, and easily appears a virtualconnect phenomenon especially in a low-density domain. The 3-D structural topology optimization method has been developed using the node density instead of the element density that is based on SIMP (solid isotropic microstructure with penalization) algorithm. A computer code based on Matlab was written to validate the proposed method. When it was compared to the element density as design variable, this method could get a more uniform density distribution. To show the usefulness of this method, several typical examples of structure topology optimization are presented.

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3 밸브형 맥동관 냉동기의 작동 해석 (Analysis of the Operation of a 3 Valve-type Pulse Tube Refrigerator)

  • 송영식;조경철;정평석
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2000년도 춘계학술대회논문집B
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    • pp.335-340
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    • 2000
  • A 3 valve-type pulse tube refrigerator optains its cooling effect from pressure drop by releasing the part of the charged gas through hot end nozzle. The objective of this study is to analyze the performance and to find an optimal expansion pressure of the 3 valve-type pulse tube refrigerator. It is assumed that gas lumps are not mixed and periodically repeat the adiabatic compression and expansion processes. And the nodal model is applied for the analysis of the regenerator. As the result of analysis, the optimum pressure at the end of expansion process was about 80-90% of the maximum pressure.

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회전형 복합마찰댐퍼 구조거동에 대한 실험적 연구 (Experimental Study on the Structural Behaviour of Rotary Friction Damper)

  • 김도현;김지영;김명한
    • 한국공간구조학회논문집
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    • 제15권4호
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    • pp.73-80
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    • 2015
  • The new rotary friction damper was developed using several two-nodal rotary frictional components with different clamping forces. Because of these components, the rotary friction damper can be activated by building movements due to lateral forces such as a wind and earthquake. In this paper, various dependency tests such as displacement amplitude, forcing frequency and long term cyclic loading were carried out to evaluate on the structural performance and the multi-slip mechanism of the new damper. Test results show that the multi-slip mechanism is verified and friction coefficients are dependent on displacement amplitute and forcing frequency except long term cyclic loading.

유체로 채워진 원통형 쉘의 고유진동수에미치는 수위의 영향 (The Effect of Liquid Level on the Natural Frequencies of a Partially Liquid-Filled Circular Cylindrical Shell)

  • 정경훈;이성철
    • 한국정밀공학회:학술대회논문집
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    • 한국정밀공학회 1995년도 춘계학술대회 논문집
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    • pp.314-319
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    • 1995
  • The effect of liquid level on the natural frequencies and mode shapes of a partially liquid-filled circular cylindrical shell with various boundary conditions is investigated by means of a theoretical analysis based upon Fourier series expansion method and a finite element analysis using ANSYS computer program. Two dimensional mode shapes of the liquid-coupled shell structure are obtained by the ANSYS finite element analysis and show that the liquid level affect the nodal point movement. It is found that the variation of normalized naturalfrequencies (natural frequencies of liquid-filled shell/antural frequencies ofempty shell) to the liquid level is depend on the axial mode numbers and circumferential wave numbers. Additionally, it is found that the number of variational steps of normalized natural frequencies is identicial to that of axial nodal points of the mode shape.

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ESPI를 이용한 평판의 Nodal Pattern 해석 (Nodal pattern analysis of plane plate by using ESPI)

  • 김경석;정현철;양승필;김정호;이도윤;김태열;김형택
    • 한국정밀공학회:학술대회논문집
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    • 한국정밀공학회 1996년도 추계학술대회 논문집
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    • pp.377-383
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    • 1996
  • Recently, a new technique called Electronic Speckle Pattern Inteferometry(ESPI) has been developed to overcome the drawbacks of existing holography. This technique enable real-time interference fringes to be displayed directly on TV monitor without recourse to any form of photographic processing. This research was carried out for the purpose of applying the vibration analysis method employing Electronic Speckle Pattern Interference technique to the vibration analysis of uniform rectangular cantilever plate, The natural vibration frequencies found by ESPI were in fair agreement with theoretical eigen frequencies acquired using theoretical formula G. B. Warburton proposed.

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갇힌 유체로 연성된 두 원판의 고유진동 해석 (Natural Vibration Analysis of Two Circular Plates Coupled with Bounded Fluid)

  • 정명조;정경훈
    • 한국소음진동공학회논문집
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    • 제11권9호
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    • pp.439-453
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    • 2001
  • This study deals with the free vibration of two identical circular plates coupled with a bounded fluid. An analytical method based on the finite Fourier-Bessel series expansion and Rayleigh-Ritz method is suggested. In the theory, it is assumed that the ideal fluid in a rigid cylindrical container and the two plates are clamped along the plate edges. The proposed method is verified by the finite element analysis using commercial program with a good accuracy. Two transverse vibration modes, namely in-phase and out-of-phase, are observed alternately in the fluid-coupled system when the number of nodal circles increases for the fixed nodal diameter. The effect of gap between the plates on the fluid-coupled natural frequencies sis also investigated.

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예방적 경부청소술의 임상적 의의에 관한 연구 (A Clinical Study of the Elective Neck Dissection)

  • 김면주;이광선;최종욱
    • 대한두경부종양학회지
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    • 제7권1호
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    • pp.10-16
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    • 1991
  • Elective neck dissection (END), provide proper information on nodal status and stage which are significant prognosticator in head and neck cancers with clinically $N_{(0)}$ neck. But there are many controversies for the extents, methods of surgery, moreover, whether normal lymph nodes, local defencer, have to be removed or not. The authors performed 47 END in 39 patients of head and neck squamous cell carcinoma from 1984 to 1989 and a retrospective study of the cases was conducted. Eighteen percent of nodal metastasis and five percent of extracapsular spread were found in END specimens. We concluded that END provide significant information for the management and evaluation of prognosis in head and neck cancer.

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Imaging characteristics of diffuse large cell extra nodal non-Hodgkin's lymphoma involving the palate and maxillary sinus: a case report

  • Nadendla, Lakshmi Kavitha;Meduri, Venkateswarlu;Paramkusam, Geetha
    • Imaging Science in Dentistry
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    • 제42권2호
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    • pp.111-114
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    • 2012
  • Non-Hodgkin's lymphomas are a group of highly diverse malignancies and have a strong tendency to affect organs and tissues that do not ordinarily contain lymphoid cells. Primary extra nodal lymphoma of the hard palate is rare. Here, we present a case of diffuse large B cell lymphoma in a 60-year-old male patient that manifested as slightly painful ulcerated growth on the edentulous right maxillary alveolar ridge extending onto the palate, closely resembling carcinoma of the alveolar ridge. Computed tomography images showed the involvement of the maxillary sinus and right nasal cavity, along with destruction of hard palate, superiorly extending into the orbit. This case report highlights the importance of imaging to evaluate the exact extent of such large malignant lesions, which is essential for treatment planning.