• Journal of Industrial Technology
• /
• v.24 no.B
• /
• pp.83-87
• /
• 2004

A reduced structure model of a wind turbine generator is designed and manufactured. Mode data are obtained by modal testing and analytical method. Vibration response is measured and investigated under various speed condition by using a waterfall plot. Possibility of severe resonance is observed and the mechanism is explained by using the mode data. Simplified theoretical model gives the 1st resonance frequency of wind turbine structure model. The theoretical model can be applied in the design stage of the wind turbine structure to avoid the severe resonance problem.

• Proceedings of the KIEE Conference
• /
• 1987.07b
• /
• pp.1125-1128
• /
• 1987

This paper proposes a method which distributes the structure data represented by a tree and handles it. To distribute and handle the structure data, this method partitions a structure data and distributes the partitioned structure in multiple processing element and allocates the partitioned structure. Each processing element includes the structure memory to store the partitioned structure and the structure controller to handle efficiently the distributed structure. As the structure is distributed and is stored in the structure memory and is handled by the structure controller, the processing time is reduced.

• Journal of the Korean Data and Information Science Society
• /
• v.9 no.1
• /
• pp.63-70
• /
• 1998

The singular value decomposition is a tool which is used to find a linear structure of reduced dimension and to give interpretation of the lower dimensional structure about multivariate data. In this paper the singular value decomposition is reviewed from both algebraic and geometric point of view and, is illustrated the way which the tool is used in the multivariate techniques finding a simpler geometric structure for the data.

• Smart Structures and Systems
• /
• v.10 no.4_5
• /
• pp.411-426
• /
• 2012

The Canton Tower (formerly named Guangzhou New TV Tower) of 610 m high has been instrumented with a long-term structural health monitoring (SHM) system consisting of over 700 sensors of sixteen types. Under the auspices of the Asian-Pacific Network of Centers for Research in Smart Structures Technology (ANCRiSST), an SHM benchmark problem for high-rise structures has been developed by taking the instrumented Canton Tower as a host structure. This benchmark problem aims to provide an international platform for direct comparison of various SHM-related methodologies and algorithms with the use of real-world monitoring data from a large-scale structure, and to narrow the gap that currently exists between the research and the practice of SHM. This paper first briefs the SHM system deployed on the Canton Tower, and the development of an elaborate three-dimensional (3D) full-scale finite element model (FEM) and the validation of the model using the measured modal data of the structure. In succession comes the formulation of an equivalent reduced-order FEM which is developed specifically for the benchmark study. The reduced-order FEM, which comprises 37 beam elements and a total of 185 degrees-of-freedom (DOFs), has been elaborately tuned to coincide well with the full-scale FEM in terms of both modal frequencies and mode shapes. The field measurement data (including those obtained from 20 accelerometers, one anemometer and one temperature sensor) from the Canton Tower, which are available for the benchmark study, are subsequently presented together with a description of the sensor deployment locations and the sensor specifications.

• The Pure and Applied Mathematics
• /
• v.9 no.1
• /
• pp.63-72
• /
• 2002

An inverse interpolation problem for rational matrix functions with a certain type of symmetricity in zero-pole structure is studied.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 1997.04a
• /
• pp.184-191
• /
• 1997

A method, termed as the substructural sensitivity synthesis method, which utilizes the computational merits of the component mode synthesis technique is proposed to calculate design sensitivity of modal parameters of substructurally combined structures. In this method, the sensitivity analysis is combined with component mode synthesis thchnique. thus the degrees of freedom of a combined structure can be dramatically reduced. Free-interface mode method including the residual attachment modes among the component mode synthesis methods is used to calculate the modal sensitivity of the combined structure. For the design sensitivities of modal properties of structure, the Nelson's method, which is exact solving method is used. It is shown that the modal sensitivities of the entire structure can be obtained by synthesizing the substructural modal data, and the sensitivities of the modal data about the design variables of modifiable substructure. Using the proposed method, the final degrees of freedom of entire structure can be remarkably reduced to calculate the modal parameter sensitivities. With a structure composed of beams and plates, as an example, the sensitivities of the eigenvalues and eigenvectors obtained by this proposed method were compared with the exact solutions in terms of accuracy.

• Journal of Korea Multimedia Society
• /
• v.14 no.8
• /
• pp.1010-1019
• /
• 2011

This was a preliminary research for the goal of understanding between internal structure of Osteogenesis Imperfecta Murine (OIM) bone and its fragility. 54 hyperspectral bone data sets were captured by using JASCO 2000 Raman spectrometer at UMKC-CRISP (University of Missouri-Kansas City Center for Research on Interfacial Structure and Properties). Each data set consists of 1,091 data points from 9 OIM bones. The original captured hyperspectral data sets were noisy and base-lined ones. We removed the noise and corrected the base-lined data for the final efficient classification. High dimensional Raman hyperspectral data on OIM bones was reduced by Principal Components Analysis (PCA) and Linear Discriminant Analysis (LDA) and efficiently classified for the first time. We confirmed OIM bones could be classified such as strong, middle and weak one by using the coefficients of their PCA or LDA. Through experiment, we investigated the efficiency of classification on the reduced OIM bone data by the Bayesian classifier and K -Nearest Neighbor (K-NN) classifier. As the experimental result, the case of LDA reduction showed higher classification performance than that of PCA reduction in the two classifiers. K-NN classifier represented better classification rate, compared with Bayesian classifier. The classification performance of K-NN was about 92.6% in case of LDA.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.13 no.2
• /
• pp.929-944
• /
• 2019

Many critical applications require accurate real-time human action recognition. However, there are many hurdles associated with capturing and pre-processing image data, calculating features, and classification because they consume significant resources for both storage and computation. To circumvent these hurdles, this paper presents a recognition machine learning (ML) based system model which uses reduced data structure features by projecting real 3D skeleton modality on virtual 2D space. The MMU VAAC dataset is used to test the proposed ML model. The results show a high accuracy rate of 97.88% which is only slightly lower than the accuracy when using the original 3D modality-based features but with a 75% reduction ratio from using RGB modality. These results motivate implementing the proposed recognition model on an embedded system platform in the future.

• Korean Journal of Computational Design and Engineering
• /
• v.2 no.3
• /
• pp.150-160
• /
• 1997

Existing non-manifold data structures which use the ordered topological representation method, are designed based on a "Model" which is the highest topological entity. Their non-manifold information is always included in edges and vertices even if they are in the manifold situation. Thus they require large storage spaces than manifold data structures. The proposed data structure reduces its storage space by removing unnecessary information stored in edges and vertices. Topological information is classified into manifold and non-manifold information. The main non-manifold information is radial cycles and disk cycles. The proposed data structure always stores manifold information. For the non-manifold situation, the edge stores radial cycles, and the vertex stores disk cycles. The storage space can be reduced in the later stage of CAD design when the ratio of non-manifold to manifold entities is small.

• Journal of the Korean Society of Fisheries and Ocean Technology
• /
• v.29 no.1
• /
• pp.39-55
• /
• 1993

Modal Analysis is the process of characterizing the dynamic properties of an elastic structure by identifying its modes of vibration. A mode of vibration is a global property of an elastic structure. That is, a mode has a specific natural frequency and damping factor which can be identified from response data at practically any point on a structure, and it has a characteristic mode shape which identifies the mode spatially over the entire structure. Modal testing is able to be performed on structural and mechanical structure in an effort to learn more about their elastic behavior. Once the dynamic properties of a structure are known its behavior can be predicted and therefore controlled or corrected. Resonant frequencies, damping factors and mode shape data can be used directly by a mechanical designer to pin point weak spots in a structure design, or this data can also be used to confirm or synthesize equations of motion for the elastic structure. These differential equations can be used to simulate structural response to know input forces and to examine the effects of pertubations in the distributed mass, stiffness and damping properties of the structure in more detail. In this paper the measurement of transfer functions in digital form, and the application of digital parameter identification techniques to identify modal parameters from the measured transfer function data are discussed. It is first shown that the transfer matrix, which is a complete dynamic model of an elastic plate structure can be written in terms of the structural modes of vibration. This special mathematical form allows one to identify the complete dynamics of the structure from a much reduced set of test data, and is the essence of the modal approach to identifying the dynamics of a structure. Finally, the application of transfer function models and identification techniques for obtaining modal parameters from the transfer function data are discussed. Characteristics on vibration response of elastic plate structure obtained from the dynamic analysis by Finite Element Method are compared with results of modal analysis.