• Title/Summary/Keyword: Internal feature

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A Study on Auto-Classification of Acoustic Emission Signals Using Wavelet Transform and Neural Network (웨이블렛 변환과 신경망을 이용한 음향방출신호의 자동분류에 관한연구)

  • Park, Jae-Jun;Kim, Meyoun-Soo;Oh, Seung-Heon;Kang, Tae-Rim;Kim, Sung-Hong;Beak, Kwan-Hyun;Oh, Il-Duck;Song, Young-Chul;Kwon, Dong-Jin
    • Proceedings of the KIEE Conference
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    • 2000.07c
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    • pp.1880-1884
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    • 2000
  • The discrete wavelet transform is utilized as preprocessing of Neural Network(NN) to identify aging state of internal partial discharge in transformer. The discrete traveler transform is used to produce wavelet coefficients which are used for Classification. The statistical parameters (maximum of wavelet coefficients, average value, dispersion, skewness, kurtosis) using the wavelet coefficients are input into an back-propagation neural network. The neurons whose weights have obtained through Result of Cross-Validation. The Neural Network learning stops either when the error rate achieves an appropriate minimum or when the learning time overcomes a constant value. The networks, after training, can decide if the test signal is Early Aging State or Last Aging State or normal state.

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Seismic assessment and retrofitting of Pombalino buildings by pushover analyses

  • Meireles, Helena;Bento, Rita;Cattari, Serena;Lagomarsino, Sergio
    • Earthquakes and Structures
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    • v.7 no.1
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    • pp.57-82
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    • 2014
  • The heritage value of the mixed wood-masonry 18th century Pombalino buildings of downtown Lisbon is recognized both nationally and internationally. The present paper focuses on the seismic assessment of global response and retrofitting of a typical Pombalino building by nonlinear static analyses, performed by the research software Tremuri, which is able to model 3D configurations. The structure is modelled using nonlinear beams for masonry panels, while in case of the internal walls (frontal walls) an original formulation has been developed in order to take into account their specific seismic behaviour. Floors are modelled as orthotropic membrane finite elements: this feature allows to simulate the presence of both flexible and rigid diaphragms, being the first ones more representative of the original state while the second ones of retrofitted configurations. Seismic assessment has been evaluated by applying nonlinear static procedure and comparing the performance of different configurations (by considering various retrofitting strategies). Finally, assuming a lognormal cumulative distribution, fragility curves are obtained to be representative of Pombalino buildings: the most important application of such curves is for seismic risk and loss estimation analyses.

A Study on the Composite Strengthening Effect in Metal Matrix Composites (단섬유 금속복합체에서의 복합강화효과에 관한연구)

  • 김홍건
    • Proceedings of the Korean Society of Machine Tool Engineers Conference
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    • 1996.03a
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    • pp.61-66
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    • 1996
  • An overall feature to simulate composite behavior and to predict closed solution has been performed for the application to the stress analysis in a discontinuous composite solid. To obtain the internal field quantities of composite, the micromechanics analysis and finite element analysis (FEA) were implemented. For the numerical illustration, an aligned axisymmetric single fiber model has been employed to assess field quantities. Further, a micromechanics model to describe the elastic behavior of fiber or whisker reinforced metal matrix composites has been developed and the stress concentrations between reinforcements were investigated using the modified shear lag model with the comparions between reinforcements were investigated using the modified shear lag model with the comparison of finite element analysis (FEA). The rationale is based on the replacement of the matrix between fiber ends with the fictitious fiber to maintain the compatibility of displacement and traction. It was found that the new model gives a good agreement with FEA results in the small fiber aspect ratio regime as well as that in the large fiber aspect ratio regime. It was found that the proposed simulation methodology for stress analysis is applicable to the complicated inhomogeneous solid for the investigation of micromechanical behavior.

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Metro Telecommunication Basis Facilities Standardization and Functional Improvement Research (도시철도 구내정보통신 기반설비 표준화 및 기능 향상방안)

  • Kim Moon-Tae;Yoon In-Young
    • Proceedings of the KSR Conference
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    • 2005.11a
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    • pp.964-968
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    • 2005
  • The standardization of information communication is doing a Internal each other connection and each other characteristic stability operation security in objective. From the low-speed network of the subway operation beginning currently it changes with the superhigh speed digital information transmission communication service environment which is a quality service, the hazard which plans the quality improvement of the efficient communication service use which hits to here and passenger service the standardization of the technical standard which stands and the improvement which hits to an engineering standard and facility must come to accomplish. The facility which existing is been old or the enclosure communication equipments which are insufficient. it improves, establishment itexpands efficiently, like this facilities it is stabilized and it is economic and rationally use maintenance it manages with the plan for the inside and outside of the country information communication relation technical standard and engineering standard service feature improvement and future expandability and economical efficiency, the possibility of having a pliability in order to be, rational technical standard and standard it takes a triangular position, efficient characteristic security of information communication service there is a place objective which promises the rational development of course city railroad communication system with character. Function improvement of enclosure communication base equipment, against an improvement and standardization plan it described trom the prosecution which it sees.

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Bisphosphonate-related osteonecrosis of the jaw in a multiple myeloma patient: A case report with characteristic radiographic features

  • Lee, Byung-Do;Park, Moo-Rim;Kwon, Kyung-Hwan
    • Imaging Science in Dentistry
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    • v.45 no.3
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    • pp.199-203
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    • 2015
  • A 59-year-old male who had suffered from multiple myeloma for nine years and had been administered bisphosphonates for seven years visited a dental hospital for pain relief due to extensive caries in his left maxillary molars. The molars were extracted, leaving an exposed wound for three months. The radiograph showed sequestra formation and irregular bone destruction in the left maxilla. Sudden pain and gingival swelling in the right mandibular molar area occurred six months later. The interseptum of the right lower second molar was observed to be necrotic during surgery. These findings coincided with the features of bisphosphonate-related osteonecrosis of the jaw (BRONJ). In this case, the long intravenous administration of bisphosphonates and tooth extraction were likely the etiologic factors of BRONJ in a patient with multiple myeloma; moreover, the bilateral occurrence of BRONJ is a characteristic feature.

A novel hardware design for SIFT generation with reduced memory requirement

  • Kim, Eung Sup;Lee, Hyuk-Jae
    • JSTS:Journal of Semiconductor Technology and Science
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    • v.13 no.2
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    • pp.157-169
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    • 2013
  • Scale Invariant Feature Transform (SIFT) generates image features widely used to match objects in different images. Previous work on hardware-based SIFT implementation requires excessive internal memory and hardware logic [1]. In this paper, a new hardware organization is proposed to implement SIFT with less memory and hardware cost than the previous work. To this end, a parallel Gaussian filter bank is adopted to eliminate the buffers that store intermediate results because parallel operations allow all intermediate results available at the same time. Furthermore, the processing order is changed from the raster-scan order to the block-by-block order so that the line buffer size storing the source image is also reduced. These techniques trade the reduction of memory size with a slight increase of the execution time and external memory bandwidth. As a result, the memory size is reduced by 94.4%. The proposed hardware for SIFT implementation includes the Descriptor generation block, which is omitted in the previous work [1]. The addition of the hardwired descriptor generation improves the computation speed by about 30 times when compared with the previous work.

Taxonomic Study of the Genus Abundisporus in Korea

  • Jargalmaa, Suldbold;Park, Myung Soo;Park, Jae Young;Fong, Jonathan J.;Jang, Yeongseon;Lim, Young Woon
    • Mycobiology
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    • v.43 no.3
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    • pp.225-230
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    • 2015
  • The polypore genus Abundisporus Ryvarden is characterized by resupinate to pileate fruitbodies with a purplish brown hymenophore, slightly thick-walled, pale yellowish and non-dextrinoid basidiospores, and causing white rot. A purple color hymenophore, an easily observable and striking character, was considered the main distinctive feature at the generic level within polypores. However, due to highly similar basidiocarp features, species identification within these purple polypores is particularly difficult. Three species of purple colored polypores have been reported in Korea (Abundisporus fuscopurpureus, A. pubertatis, and Fomitopsis rosea). Based on morphological re-examination, ecological information, and sequence analysis of the internal transcribed spacer, we showed that previous classification was incorrect and there is only one species (A. pubertatis) in Korea. We provide a detailed description of A. pubertatis in Korea, as well as a taxonomic key to distinguish wood rot fungi with a purple hymenophore.

Study on Usability of Cave Type Classification using Cluster Analysis (군집분석을 이용한 동굴 유형분류의 유용성에 관한 연구)

  • Hong, Hyun-Cheol
    • Journal of the Speleological Society of Korea
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    • no.84
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    • pp.1-9
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    • 2008
  • Since the existing cave type classification has no variety but was limited to the structural, genetical and dimensional classification, we need the new cave type classification. When we analyze the theoretical background of cluster analysis, the cave type can be classified in consideration of diverse variables depending on the selection of variables to use and the usability of such classification is very high. With the practical consideration on the internal environment of cave and surrounding environment, three classifications are available; first, numerical classification by the dimension and form of cave; second, classification by the use of land out of the cave and geographic features; third, classification by the feature of location related to the surrounding areas of cave.

A Study on Feature Extraction of Partial Discharge Type Using Wavelet Transform (웨이블렛변환을 이용한 부분방전 종류의 특징추출에 관한 연구)

  • Park, Jae-Jun
    • The Journal of Information Technology
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    • v.6 no.1
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    • pp.65-70
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    • 2003
  • In this papers, we proposed the new method in order to diagnosis partial discharge type of transformers. For wavelet transform, Daubechie's filter is used,, we can obtain wavelet coefficients which is used to extract featrue of statistical parameters(maximum value, average value, dispersion, skewness, kurtosis) about high frequency current signal per 3-electrode type(needle-plane electrode, IEC electrode and Void electrode). Also, these coefficients are used to identify signal of internal partial discharge in transformer. As a result, from compare of high frequency current signal amplitude and average value, we are obtained results of IEC electrode> Void electrode> Needle-Plane electrode. Otherwise, in case of skewness and kurtosis, we are obtained results of Void electrode> IEC electrode> Needle-Plane electrode. As improved method in order to diagnosis partial discharge type of transformers, we use neural network.

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A Study on Development of Automobile Interior Parts through Al-Insert Injection Moulding (Al-Insert 사출성형을 이용한 자동차 내장재 부품 개발에 관한 연구)

  • Lho T.J.;Kim J.Y.;Kang D.J.;Kim J.H.;Kim G.Y.
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2005.10a
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    • pp.170-175
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    • 2005
  • Generally, Aluminum is superior to durability, light, and characteristics of the material are embossed luminant. So, these characteristics of aluminum will be used automobile interior parts by aluminum injection moulding. Especially, The external of Aluminum plate is engraved differing pattern by roller working. This working can use any longer and be seen gracefully. This is the reason why aluminum insert moulding is used. This feature of research can be characterized by simple process to customize aluminum sheet of blanking and forming process with internal parts of configuration if products are injected by aluminum sheet. Besides, to analysis completed Automobile interior parts to be concerned volumetric shrinkage, best gate location, fill time analysis and so on through the mold-flow before the aluminum insert moulding is worked.

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