• Proceedings of the KIEE Conference
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• 2004.11a
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• pp.107-109
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• 2004

It is well known that on-site corona and various noises make severe problems on the PD(partial discharge) measurement. In this paper, for the improvement of the on-site PD measuring performance, the applicability of TF(Time-Frequency) map was investigated. For the purpose, PDs that can be generated from the defect in the power cables as well as corona discharges and ground noises were measured. And through the TF analysis for the measured data, we have tried to distinguish the real PDs, corona discharges and noises. As a result, it is confirmed that the data of PDs can be clustered themselves separable from other data such as corona and noises on the TF map.

• Proceedings of the KIEE Conference
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• 2005.07c
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• pp.2126-2128
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• 2005

In this paper, it was investigated the applicability of TF analysis for the discrimination of air corona in on-site PD measurement. For the purpose, single and multiple discharges combined with oil discharges and air corona were generated and measured by use of artificial models and HFPD pulse detector. Through the TF analysis, data clusters could be classified each other in the TF Map, even in the case of multiple discharges. Therefore, it is known that TF analysis could be applied for the improvement of on-site PD measurement.

• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.1457_1458
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• 2009

지난 10년여간의 국내외 연구 결과 배전 케이블에 대한 부분방전 측정기술의 정확성은 상당히 향상되었고 그 결과물로서 수많은 측정 장비와 기법이 개발되어 오늘날 널리 보급되고 있다. 하지만 여전히 측정된 Data에 대한 해석은 일부 전문가들에게 조차 복잡하고 어려운 일로 남아 있다, 자칫 그릇된 해석은 향후 큰 사고로 이어질 수 있으므로 선로 운영자의 입장에서는 측정결과의 신뢰성에 민감할 수밖에 없다. 이러한 신뢰성을 높이 고자 기존에 많이 사용되고 있는 PRPDA기법의 단점을 보안 할 수 있는 TF-MAP을 활용한 배전 케이블 부분방전 측정 시스템을 개발 하였다.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.54 no.11
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• pp.508-514
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• 2005

In this paper, it was investigated the characteristics of PD(partial discharge) pulse shapes in oil and the possibility of TF(Time-Frequency) analysis for the discrimination of air corona in on-site PD measurement of oil transformers. For the purpose, single and multiple discharges combined with oil discharges and air corona were generated and measured by use of artificial models through the HFPD pulse detector and the oscilloscope. PD pulse shapes were different according to the type of defects, especially including air corona- pulses. Also, through the TF analysis, data clusters could be classified each other in the TF Map, even in the case of multiple discharges. Therefore, it is known that TF analysis could be aprlied for the improvement of on-site PD measurement in oil transformers.

• Journal of the Korea Society of Computer and Information
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• v.25 no.12
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• pp.173-186
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• 2020

In this paper, we design and implement a service system for mobile devices to utilize the integrated underground geospatial information map in underground exploration fields. The field utilization service system for mobile devices is designed to visualize tiled maps, 3D terrain information, underground structures, underground facilities, and ground information provided by the Integrated Underground Geospatial Information Map Management System according to current position. And It is designed to reflect the results obtained from field exploration in real time. Also, the proposed system is implemented to transfer and visualize the integrated underground geospatial information map in the form of a glTF format due to constraints on wireless networks and device characteristics of mobile devices. Implemented mobile service systems can prevent accidents in underground exploration field from occurring by providing users with accurate and integrated underground geospatial data by visualizing maps and geospatial objects in three dimensions at underground exploration fields. In addition, updated underground geospatial data is transmitted in real time to the Integrated Underground Geospatial Information Map Management Systems, which can maintain up to date and accuracy.

• Korean Journal of Plant Tissue Culture
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• v.27 no.5
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• pp.367-373
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• 2000

We have constructed a molecular linkage map of chili pepper (Capsicum spp.) in an interspecific (C. annuum cv. TF68 x C. chinense cv. Habanero) F$_2$ population of 107 plants with 150 RFLP and 430 AFLP markers. The resulting linkage map consists of 11 large (206-60.3 cM) and 5 small (32.6- 10.3 cM) linkage groups cover-ing 1,320 cM with an average map distance between framework markers of 7.5 cM. Most (80%) of the RFLP markers were pepper-derived clones and these markers were evenly distributed across the genome. By using 30 primer combinations, 444 AFLP markers were generated in the F$_2$population. The majority of the AFLP markers clustered in each linkage group, although PstI/MseI markers were more evenly distributed than Eco RI/MseI markers within the linkage groups. Genes for biosynthesis of carotenoids and capsaicinoids were mapped on our linkage map. This map will provide the basis of studying secondary metabolites in pepper.

• The Korean Journal of Nuclear Medicine Technology
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• v.16 no.2
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• pp.68-80
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• 2012

Purpose : More recently, combined PET/MR scanners have been developed in which the MR data can be used for both anatometabolic image formation and attenuation correction of the PET data. For quantitative PET information, correction of tissue photon attenuation is mandatory. The attenuation map is obtained from the CT scan in the PET/CT. In the case of PET/MR, the attenuation map can be calculated from the MR image. The purpose of this study was to assess the quantitative differences between MR-based and CT-based attenuation corrected PET images. Materials and Methods : Using the uniform cylinder phantom of distilled water which has 199.8 MBq of $^{18}F$-FDG put into the phantom, we studied the effect of MR-based and CT-based attenuation corrected PET images, of the PET-CT using time of flight (TOF) and non-TOF iterative reconstruction. The images were acquired from 60 minutes at 15-minute intervals. Region of interests were drawn over 70% from the center of the image, and the Scanners' analysis software tools calculated both maximum and mean SUV. These data were analyzed by one way-anova test and Bland-Altman analysis. MR images are segmented into three classes(not including bone), and each class is assigned to each region based on the expected average attenuation of each region. For clinical diagnostic purpose, PET/MR and PET/CT images were acquired in 23 patients (Ingenuity TF PET/MR, Gemini TF64). PET/CT scans were performed approximately 33.8 minutes after the beginnig of the PET/MR scans. Region of interests were drawn over 9 regions of interest(lung, liver, spleen, bone), and the Scanners' analysis software tools calculated both maximum and mean SUV. The SUVs from 9 regions of interest in MR-based PET images and in CT-based PET images were compared. These data were analyzed by paired t test and Bland-Altman analysis. Results : In phantom study, MR-based attenuation corrected PET images generally showed slightly lower -0.36~-0.15 SUVs than CT-based attenuation corrected PET images (p<0.05). In clinical study, MR-based attenuation corrected PET images generally showed slightly lower SUVs than CT-based attenuation corrected PET images (excepting left middle lung and transverse Lumbar) (p<0.05). And percent differences were -8.01.79% lower for the PET/MR images than for the PET/CT images. (excepting lung) Based on the Bland-Altman method, the agreement between the two methods was considered good. Conclusion : PET/MR confirms generally lower SUVs than PET/CT. But, there were no difference in the clinical interpretations made by the quantitative comparisons with both type of attenuation map.

• The Korea Journal of Herbology
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• v.32 no.2
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• pp.107-114
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• 2017

Objectives : Tribulus terrestris $Linn{\acute{e}}$ (Tribuli Fructus; TF) has been used to treat hypochondrium, agalactia, nebula, itching and vitiligo in traditional Korean medicine. In this study, we investigated the effects of TF 30% ethanol extract on inflammatory responses in IgE-stimulated RBL-2H3 mast cells. Methods : TF extract was prepared by 30% ethanol. RBL-2H3 cells, a rat mast cell line, were treated with TF extract at different concentrations for 1 hr and then stimulated with DNP-IgE/HSA for indicated times. Cell viability was measured by WST-1 assay. The expression of inflammatory cytokines (IL-4, IL-13 and $IFN-{\gamma}$) mRNA was determined by reverse transcriptase-PCR, and the phosphorylation of ERK1/2, p38 and JNK MAP kinases (MAPKs) was determined by Western blot. The nuclear expression of $NF-{\kappa}B$ p65 in the cells was detected by Western blot and immunocytochemistry, respectively. Results : The treatment of TF extract at 0.1 and $0.2mg/m{\ell}$ significantly decreased the expression of IL-4 and IL-13 mRNA in IgE-stimulated RBL-2H3 mast cells, while significantly increased the expression of $IFN-{\gamma}$ mRNA. TF extract treatment was also inhibited the phosphorylation of ERK1/2, p38 and JNK MAPKs in IgE-stimulated RBL-2H3 mast cells in a dose-dependent manner. In addition, TF extract significantly blocked the translocation of $NF-{\kappa}B$ p65 into the nuclear of cells after IgE stimulation. Conclusions : These results indicate that TF extract inhibits inflammatory response in IgE-stimulated mast cells through blocking MAPKs/$NF-{\kappa}B$ pathway. This suggests that TF extract has an anti-inflammatory activity in mast cell activation.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.25 no.3
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• pp.229-235
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• 2012

This paper dealt with the fabrication of a partial discharge (PD) analyzer for insulation diagnosis of power facilities like transformers, cables and gas-insulated switchgears. An analytic algorithm for the phase (${\phi}$), the magnitude (q), and the pulse count (n) of PD pulse was designed and a time-frequency (TF) map algorithm was applied in the system to eliminate noises by analyzing the time and the frequency component of signals. All the algorithms were operated by a LabView graphical program. The detection circuit consists of a coupling capacitor, a detection impedance, and a low noise amplifier. A plane-plane and a point-plane electrode system were fabricated to simulate different types of insulation defects. In the experiment, we could easily understand the characteristics of PD pulses using the prototype PD analyzer.

• KIPS Transactions on Software and Data Engineering
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• v.7 no.12
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• pp.477-484
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• 2018

Due to the advancement of computer and information technologies, numerous papers have been published. As new research fields continue to be created, users have a lot of trouble finding and categorizing their interesting papers. In order to alleviate users' this difficulty, this paper presents a method of grouping similar papers and clustering them. The presented method extracts primary keywords from the abstracts of each paper by using TF-IDF. Based on TF-IDF values extracted using K-means clustering algorithm, our method clusters papers to the ones that have similar contents. To demonstrate the practicality of the proposed method, we use paper data in FGCS journal as actual data. Based on these data, we derive the number of clusters using Elbow scheme and show clustering performance using Silhouette scheme.