• Title/Summary/Keyword: POD technique

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EXAMPLES OF REDUCED ORDER MODELLING FOR A 3D BACKWARD FACING STEP FLOW USING POD TECHNIQUE (POD를 사용한 3차원 후향계단 유동장 분석 예제)

  • Lee, K.S.;Lee, E.S.
    • 한국전산유체공학회:학술대회논문집
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    • 2010.05a
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    • pp.40-42
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    • 2010
  • Unsteady CFD results of the backward facing step (BFS) flow field is reconstructed by the low-dimenstional modes using the POD (Proper Orthogonal Decomposition) technique. Flow responses to the blowing or suction with various frequencies and amplitudes applied at the edge of the BFS can also be analysed using the same technique. The present technique can be effectively applied to the feedback flow control device.

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Web-based POD system Using Multi-Layer Technique (멀티레이어 기법을 활용한 웹기반 POD 시스템)

  • Lee, Byung-Kwon;Kim, Hak-Jin;Jung, Hoe-Kyung
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.16 no.6
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    • pp.1193-1198
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    • 2012
  • In this paper, we design and implement A4 sized, web-based POP(Print On Demand) system using multi-layer technique. We Propose the framework of POP system, which uses multi-layer technique, uses highly accessible web-service, produces template, enables a user to easily edit, and allows the user to instantly print edited files. This system will be widely used in web-based electronic publication and e-book.

Modal Parameter Estimation of a Steel Frame Structure by Using Free Vibration Displacement Data (자유진동 변위데이터를 이용한 철골구조물의 모드인자 파악)

  • Ham, Hee-Jung
    • Journal of Industrial Technology
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    • v.29 no.A
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    • pp.19-25
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    • 2009
  • The proper orthogonal decomposition (POD) analysis of vibration of a steel frame structure is performed to extract modal parameters. The theoretical background of the POD method is introduced briefly, and this technique is further applied to free vibration displacements of one bay-two story steel frame structure to extract the modal parameters. From the POD analysis of the steel frame structure, it is found that important modal parameters such as true mode shapes, modal kinematic energy, natural frequencies, and damping ratios can be obtained for the building efficiently and in detail. Therefore, it is concluded that the POD method could be one of the useful techniques in analysis of vibration of structures.

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A REDUCED-ORDER MODELLING FOR ROSENAU-RLW EQUATION WITH B-SPLINE GALERKIN FINITE ELEMENT METHOD

  • Jia, Li-Jiao;Piao, Guang-Ri
    • Journal of the Chungcheong Mathematical Society
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    • v.32 no.3
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    • pp.261-280
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    • 2019
  • We apply a reduced-order method based on B-spline Galerkin finite elements formulation to Rosenau-RLW equation for the first time and explain their process in detail. The ensemble of snapshots is very large generally, and it is difficult to apply POD to the ensemble of snapshots directly. Hence, we try to pick up important snapshots among the whole data. In this paper, we represent three different reduced-order schemes. First, the classical POD technique is examined. Second, (equally sampled snapshots) are exploited for POD technique. Finally, afterward sampling snapshots by CVT, for those snapshots, POD technique is implemented again.

Web-based POD system Using Multi-Layer Technique (멀티레이어 기법을 활용한 웹기반 POD 시스템)

  • Wu, Jing;Liu, Hao;Park, Man-Seop;Lee, Seong-Ok;Jung, Hoe-Kyung
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2012.05a
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    • pp.498-499
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    • 2012
  • In this paper, we design and implement A4 sized, web-based POP(Print On Demand) system using multi-layer technique. We Propose the framework of POP system, which uses multi-layer technique, uses highly accessible web-service, produces template, enables a user to easily edit, and allows the user to instantly print edited files. This system will be widely used in web-based electronic publication and e-book.

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Study of Analysis Technique of Flight Compatibility Test Data using Instrumented Pod for External Store (외부장착 계측포드를 사용한 비행적합성 자료 분석기법 연구)

  • Kim, Jong-Heon;Jun, Oo-Chul;Jun, Seung-Moon
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.33 no.8
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    • pp.105-110
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    • 2005
  • Analysis technique of flight compatibility test results using instrumented pod for external store is studied. Raw data of sensors and MIL-STD-1553B acquired from instrumented pod are analyzed separately. Besides, tuning and synchronization of sensor data enable the analysis of those two type of data simultaneously. Evaluation of analysis result shows that the analyzed data represent maneuvers of the aircraft successfully and agree the values of the real flight tests.

Linearized Modeling Technique for Complex Dynamic Responses Using Proper Orthogonal Decomposition (적합직교분해법을 이용한 복잡한 동적응답의 선형화 모델링 기법)

  • Lee, Soo-Il;Hong, Sang-Hyuk
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2008.04a
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    • pp.156-159
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    • 2008
  • Proper orthogonal decomposition is a statistical pattern analysis technique for finding the dominant components, called the proper orthogonal modes, in ensembles of spatially distributed data. We present recent ideas based on proper orthogonal decomposition (POD) and detailed experiments that yield new perspectives into the microscale structures. The linearized modeling technique based on POD is very useful to show the principal characteristics of the complex dynamic responses.

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Finite Element Model Building Procedure of an External Mounting Pod for Structural Dynamic Characteristics Analysis of an Aircraft (항공기 구조 동특성 해석을 위한 외부 장착 포드의 유한요소모델 구축 절차)

  • Lee, Jong-Hak;Ryu, Gu-Hyun;Yang, Sung-Chul;Jung, Dae-Yoon
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2011.10a
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    • pp.72-77
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    • 2011
  • In this study, the natural frequencies and mode shape of an external mounting pod were verified using the modal analysis and modal testing technique for a pod mounted on an aircraft. The procedure associated with the FEM building of an external mounted pod to predict the dynamic behavior of aircraft structures is described. The simplified FEM reflecting the results of the modal testing of a pod is built through the optimization, applied to the structural dynamic model of an Aircraft, used to verified the stability of vibration and flutter of an aircraft.

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New Technical Tip for Anterior Cervical Plating : Make Hole First and Choose the Proper Plate Size Later

  • Park, Jeong-Yoon;Zhang, Ho-Yeol;Oh, Min-Chul
    • Journal of Korean Neurosurgical Society
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    • v.49 no.4
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    • pp.212-216
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    • 2011
  • Objective : It is well known that plate-to-disc distance (POD) is closely related to adjacent-level ossification following anterior cervical plate placement. The study was undertaken to compare the outcomes of two different anterior cervical plating methods for degenerative cervical condition. Specifically, the new method involves making holes for plate screws first with an air drill and then choosing a plate size. The other method was standard, that is, decide on the plate size first, locate the plate on the anterior vertebral body, and then drilling the screw holes. Our hypothesis was that the new technical tip may increase POD as compared with the standard anterior cervical plating procedure. Methods : We retrospectively reviewed 49 patients who had a solid fusion after anterior cervical arthrodesis with a plate for the treatment of cervical disc degeneration. Twenty-three patients underwent the new anterior cervical plating technique (Group A) and 26 patients underwent the standard technique (Group B). POD and ratios between POD to anterior body heights (ABH) were measured using postoperative lateral radiographs. In addition, operating times and clinical results were reviewed in all cases. Results : The mean durations of follow-up were $16.42{\pm}5.99$ (Group A) and $19.83{\pm}6.71$ (Group B) months, range 12 to 35 months. Of these parameters mentioned above, cephalad POD (5.43 versus 3.46 mm, p=0.005) and cephalad POD/ABH (0.36 versus 0.23, p=0.004) were significantly greater in the Group A, whereas operation time for two segment arthrodesis (141.9 versus 170.6 minutes, p=0.047) was significantly lower in the Group A. There were no significant difference between the two groups in caudal POD (5.92 versus 5.06 mm), caudal POO/ABH (0.37 versus 0.32) and clinical results. Conclusion : The new anterior cervical plating method represents an improvement over the standard method in terms of cephalad plate-to-disc distance and operating time.

Fluctuating Wind Pressures on High Aspect Ratio Circular Cylinder

  • Keisuke Miura;Masahiro Matsui
    • International Journal of High-Rise Buildings
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    • v.11 no.4
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    • pp.277-286
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    • 2022
  • In this study, The POD technique was applied to the fluctuating wind pressure of high aspect ratio circular cylinder to consider about its organizational structure, and considered about the characteristics of the fluctuating wind force obtained by synthesized the POD modes.