• Title/Summary/Keyword: POD analysis

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Genetic Diversity of Soybean Pod Shape Based on Elliptic Fourier Descriptors

  • Truong Ngon T.;Gwag Jae-Gyun;Park Yong-Jin;Lee Suk-Ha
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.50 no.1
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    • pp.60-66
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    • 2005
  • Pod shape of twenty soybean (Glycine max L. Merrill) genotypes was evaluated quantitatively by image analysis using elliptic Fourier descriptors and their principal components. The closed contour of each pod projection was extracted, and 80 elliptic Fourier coefficients were calculated for each contour. The Fourier coefficients were standardized so that they were invariant of size, rotation, shift, and chain code starting point. Then, the principal components on the standardized Fourier coefficients were evaluated. The cumulative contribution at the fifth principal component was higher than $95\%$, indicating that the first, second, third, fourth, and fifth principal components represented the aspect ratio of the pod, the location of the pod centroid, the sharpness of the two pod tips and the roundness of the base in the pod contour, respectively. Analysis of variance revealed significant genotypic differences in these principal components and seed number per pod. As the principal components for pod shape varied continuously, pod shape might be controlled by polygenes. It was concluded that principal component scores based on elliptic Fourier descriptors yield seemed to be useful in quantitative parameters not only for evaluating soybean pod shape in a soybean breeding program but also for describing pod shape for evaluating soybean germplasm.

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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Stability Analysis of an Mounting Equipment for External Pod on Aircraft by Road Test (항공기 외장형 포드 장착장비의 주행 안정성 분석)

  • Lee, Jong-Hak;Jang, Jong-Youn;Kang, Young-Sik;Choi, Ji-Ho;Kang, Dong-Seok
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2013.10a
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    • pp.424-429
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    • 2013
  • The trolley carrying the pod moves along by the airfield runway. The pod through the trolley are subjected to vibration arising from the ground state, the precision optical components in the pod can have a significant impact. The road tests were conducted by using the measurement pod to remove the risk for the project. The measurement pod was composed with the ACRA, sensors, battery. The accelerometers were attached to get the acceleration through the road condition. The PSD envelop was calculated by FFT from the acceleration. The driving safety was proven through comparing the measurement data and MIL-STD-810G specification.

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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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Performance Analysis According to The Number of Pods Managed by Kubelet in Kubernetes (Kubernetes의 kubelet이 관리하는 pod의 수에 따른 성능 영향 분석)

  • Kwon, Min-su;Lee, Jae-Hak;Myung, Rohyoung;Yu, Heonchang;Gil, Joon-Min
    • Proceedings of the Korea Information Processing Society Conference
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    • 2018.10a
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    • pp.74-76
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    • 2018
  • 클라우드 벤더들은 많은 컨테이너를 효율적으로 배포하기 위해 컨테이너 관리 도구를 사용한다. 컨테이너 관리 도구는 Availability, Self-healing, Automated rollouts and rollback 등 여러 기능을 제공한다. 많은 관리 도구 중 Kubernetes는 가장 최소 단위로 컨테이너의 추상적인 모임 pod을 배포한다. pod에 대한 정보는 마스터에서 정의되며 슬레이브 노드에 배포된다. 슬레이브 노드에는 마스터의 명령을 받아 pod을 관리하는 노드 에이전트 kubelet이 생성된다. 하나의 노드에 할당된 자원과 상관없이 kubelet이 관리하는 pod의 개수가 많아지게 되면 작업 중인 pod이 CPU를 훔치는 오버헤드가 발생한다. 따라서 본 논문에서는 pod의 개수에 따른 CPU사용률 실험을 통해 kubelet이 효율적으로 관리할 수 있는 pod의 개수를 분석한다.

Proper Orthogonal Decomposition Analysis of Dynamic Wind Pressures Acting on a Tall Tower Model (고층 타워에 작용하는 동적 풍압력의 POD 방법을 이용한 시공간적 특성 해석)

  • Yi, Mee-Hwa;Ham, Hee-Jung
    • Journal of Industrial Technology
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    • v.24 no.B
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    • pp.29-36
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    • 2004
  • The wind and wind-induced dynamic wind pressures fluctuate irregularly according to time and space. In this study, the proper orthogonal decomposition(POD) technique is applied to wind pressures acting on a tall tower model, and the following results are found: the along-wind and across-wind forces can be reconstructed by only four dominant POD modes, and the reconstructed errors are 4.71% and 22%, respectively for across-wind and along-wind directions. The physical meanings for dominant modes are also presented in the paper. The POD analysis can compress complex wind pressure data only by a few dominant modes and interpret spatio-temporal characteristics of wind pressure by novel way while existing statistical methods do not have such benefits.

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Analysis and Reconstruction of the 2-D Cylinder Wake Flow Using POD (적합직교분해를 이용한 2차원 실린더 후류 유동장 분석 및 재구성)

  • Rhee, Hui-Nam;Kim, Gi-Hee
    • Journal of the Korea Institute of Military Science and Technology
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    • v.13 no.1
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    • pp.164-169
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    • 2010
  • Proper Orthogonal Decomposition (POD) is applied to the analysis of 2-dimensional cylinder wake flow. Time histories of flow variables were obtained by the incompressible CFD analysis. By using the method of snapshots the correlation matrix was constructed, and then eigenvalues, POD modes and time coefficients were calculated. Finally the flow field was reconstructed by using a few of the lower POD modes, and compared to the original ones.

Design and Analysis for the POD Type Waterjet System (POD형 물분사 추진장치의 설계 및 성능해석)

  • Kim, Moon-Chan;Chun, Ho-Hwan;Park, Won-Kyu;Byun, Tae-Young;Kim, Jong-Hyun;Suh, Sung-Bu
    • Journal of the Society of Naval Architects of Korea
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    • v.42 no.3
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    • pp.290-298
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    • 2005
  • A study of design and analysis for the POD type waterjet is conducted. The analysis and design of waterjet system are more difficult than that of conventional propulsor because waterjet is complicatedly composed of many parts which are impeller, stator, inlet, nozzle, etc. The streamline method is traditionally used in the design of pump whose characteristics are similar to those of waterjet. This streamline method, however, has some limitation in analysis of a viscous flow as well as the interaction of inlet part of hull. In the present study, the developed CFD program is applied to the analysis of POD type waterjet. The developed program is first validated by comparing the existed experimental results. The designed waterjet system is also analyzed by the developed CFD program and analyzed results show that the performance of the present POD type waterjet is above the requirement.

Improving Nutritional Quality of Cocoa Pod (Theobroma cacao) through Chemical and Biological Treatments for Ruminant Feeding: In vitro and In vivo Evaluation

  • Laconi, Erika B.;Jayanegara, Anuraga
    • Asian-Australasian Journal of Animal Sciences
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    • v.28 no.3
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    • pp.343-350
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    • 2015
  • Cocoa pod is among the by-products of cocoa (Theobroma cacao) plantations. The aim of this study was to apply a number of treatments in order to improve nutritional quality of cocoa pod for feeding of ruminants. Cocoa pod was subjected to different treatments, i.e. C (cocoa pod without any treatment or control), CAm (cocoa pod+1.5% urea), CMo (cocoa pod+3% molasses), CRu (cocoa pod+3% rumen content) and CPh (cocoa pod+3% molasses+Phanerochaete chrysosporium inoculum). Analysis of proximate and Van Soest's fiber fraction were performed on the respective treatments. The pods were then subjected to an in vitro digestibility evaluation by incubation in rumen fluid-buffer medium, employing a randomized complete block design (n = 3 replicates). Further, an in vivo evaluation of the pods (35% inclusion level in total mixed ration) was conducted by feeding to young Holstein steers (average body weight of $145{\pm}3.6kg$) with a $5{\times}5$ latin square design arrangement (n = 5 replicates). Each experimental period lasted for 30 d; the first 20 d was for feed adaptation, the next 3 d was for sampling of rumen liquid, and the last 7 d was for measurements of digestibility and N balance. Results revealed that lignin content was reduced significantly when cocoa pod was treated with urea, molasses, rumen content or P. chrysosporium (p<0.01) with the following order of effectiveness: CPh>CAm>CRu>CMo. Among all treatments, CAm and CPh treatments significantly improved the in vitro dry matter and organic matter digestibility (p<0.05) of cocoa pod. Average daily gain of steers receiving CAm or CPh treatment was significantly higher than that of control (p<0.01) with an increase of 105% and 92%, respectively. Such higher daily gain was concomitant with higher N retention and proportion of N retention to N intake in CAm and CPh treatments than those of control (p<0.05). It can be concluded from this study that treatment with either urea or P. chrysosporium is effective in improving the nutritive value of cocoa pod.

POD analysis of crosswind forces on a tall building with square and H-shaped cross sections

  • Cheng, L.;Lam, K.M.;Wong, S.Y.
    • Wind and Structures
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    • v.21 no.1
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    • pp.63-84
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    • 2015
  • The shape of a tall building has significant impact on wind force generation and wind-induced dynamic response. To study the effect of recessed cavities, wind excitations on a wind-tunnel model of an H-section tall building were compared with those on a square-section building model. Characteristics of the fluctuating wind pressures on the side faces of the two tall buildings and their role in the generation of crosswind forces on the buildings were investigated with the space-time statistical tool of proper orthogonal decomposition (POD). This paper also compares the use of different pressure data sets for POD analysis in situations where pressures on two different surfaces are responsible for the generation of a wind force. The first POD mode is found to dominate the generation of crosswind excitation on the buildings.