• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.09a
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• pp.60-66
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• 2001

Because of internal voids in insulators give rise to partial discharge(PD), which cause local breakdown and even entire insulation breakdown. Treeing due to PD is one of the main causes of breakdown of the insulating materials and reduction of the insulation life. Therefore the necessity for establishing a method to diagnose the aging of insulation materials and to predict the breakdown of insulation has become important. From this viewpoint, our studies diagnose insulation degradation using the method of computer sensing system, which has the advantages of PD and acoustic emission(AE) sensing system. To use advantages of these two methods can be used effectively to search for treeing location and PD in some materials. In analysis method of degradation, We analyzed the PD pulse and AE pulses by regression analysis, compared to these obtained the correlation coefficient and determination coefficient by T-distribution and saw that PD and AE pulses show a similar pattern on the whole. This is in agreement with the results of the research by Yoshimura and Fujita.

• The Korean Journal of Mycology
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• v.45 no.4
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• pp.259-269
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• 2017

In order to investigate the diversity of yeasts from major rivers (the Daejeoncheon, Gapcheon and Yudeungcheon) located in Daejeon city, we isolated wild yeasts by plating diluents of samples collected during the summer and winter of 2016 onto yeast extract-peptone-dextrose (YPD) medium, then identified them using Basic Local Alignment Search Tool (BLAST) analysis to compare the nucleotide sequences of the PCR amplicons for the D1/D2 domain of 26S rDNA. In total, we isolated 191 yeast strains belonging to 104 species from 148 soil or water samples from the rivers and their junctions. Candida spp. (45 strains) including Candida tropicalis (22 strains) were the most abundantly isolated strains from the Daejeoncheon. Candida spp. (16 strains) including Candida vartiovaarae (8 strains) and Candida spp. (18 strains) such as Candida sake (4 strains) were also the dominant isolates from the Gapcheon and Yudeungcheon, respectively. In conclusion, Candida spp. and Cryptococcus spp. were the most dominant strains, corresponding to 42% and 7% of the 191 yeast strains isolated in this study, respectively.

• Journal of Acupuncture Research
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• v.33 no.1
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• pp.79-93
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• 2016

Objectives : The purpose of this study is to explore research trends in gold implantation therapy performed on the animal and human body, through a review of clinical studies focused on gold thread, gold needle and gold bead. Methods : Medical databases, including Pubmed, CENTRAL, MEDLINE, EMBASE, RISS4u, KISTI, OASIS and KTKP, were searched for relevant articles published from their launch to December 31, 2015 using the key word 'gold' with '$thread^*$', '$needle^*$', '$acupuncture^*$', '$wire^*$', '$bead^*$', '$embed^*$', '$implant^*$', or '$insert^*$'. The results were classified into in vivo studies, clinical trials and clinical reports. Analysis of the results was conducted in several research areas, from the identity of studies such as nationality and published year, to the gold preparations-features and implanted locations and to the outcomes that reflect the clinically favorable or adverse effect of gold implantation therapy. Results : A total of 30 studies including 11 in vivo studies, 4 clinical trials and 15 case reports, were found in the search. We observed certain research trends according to the research time, nationality and target indication of the studies. The studies primarily revealed a chronic local inflammatory response which could be a useful mechanism for pain-relief in musculoskeletal diseases and facial rejuvenation. Researches concerning long-term reactions or adverse effects were rare. Conclusion : The results show that the efforts to discover the level of clinical efficacy of gold implantation therapy were steady and worldwide. However, further researches on the longterm effect, and more importantly, the safety of gold implantation therapy are required.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.11 no.4
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• pp.2038-2057
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• 2017

Gaussian learning is a new technology in the computational intelligence area. However, this technology weakens the learning ability of a particle swarm and achieves a lack of diversity. Thus, this paper proposes a vector Gaussian learning strategy and presents an effective approach, named particle swarm optimization based on vector Gaussian learning. The experiments show that the algorithm is more close to the optimal solution and the better search efficiency after we use vector Gaussian learning strategy. The strategy adopts vector Gaussian learning to generate the Gaussian solution of a swarm's optimal location, increases the learning ability of the swarm's optimal location, and maintains the diversity of the swarm. The method divides the states into normal and premature states by analyzing the state threshold of the swarm. If the swarm is in the premature category, the algorithm adopts an inertia weight strategy that decreases linearly in addition to vector Gaussian learning; otherwise, it uses a fixed inertia weight strategy. Experiments are conducted on eight well-known benchmark functions to verify the performance of the new approach. The results demonstrate promising performance of the new method in terms of convergence velocity and precision, with an improved ability to escape from a local optimum.

• Journal of the Economic Geographical Society of Korea
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• v.21 no.2
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• pp.173-191
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• 2018

Taking note of growing tendency of academic interests and policy applications with regard to social economy, this study aims to suggest economic geographical agenda for social economy. It is presumed that the orientation of social economy toward pursuing social value will exhibit unique spatial characteristics. Elements containing spatial implications have been identified through a review of hierarchial concepts including social innovation, social economy organization and social enterprise. Three approached are suggested as tools of understanding the spatial context of social economy: spatial characteristics inspiring social entrepreneurship, place-based context of decision-making by social economy organizations, and spaces formulated by interactions between the demand for solving social problems and the supply of economic resources. The investigation of social innovation clusters is required to focus on the differentiated characteristics from normal industrial clusters. It is also suggested that the concept of embeddedness be applied in the search of the essence and elements of social economy's ties with local community.

• The Journal of the Korea institute of electronic communication sciences
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• v.9 no.12
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• pp.1345-1352
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• 2014

Bus architecture of SoC has been replaced by NoC in recent years. Noc uses the multi-clock domains to transmit and receive data between neighbor network interfaces and they have same frequency, but a phase difference because of clock skew. So a synchronizer is used for a mesochronous frequency in interconnection between network interfaces. In this paper the metastability is defined and analyzed in a D latch and a D flip-flop to search the possibilities that data can be lost in the process of sending and receiving data between interconnects when a local frequency and a transmitted frequency have a phase difference. 180nm CMOS model parameter and 1GHz are used to simulate them in HSpice. The simulation results show that the metastability happens in a latch and a flip-flop when input data change near the clock edges and there are intermediate states for a longer time as input data change closer at the clock edge. And the next stage can lose input data depending on environmental conditions such as temperature, processing variations, power supply, etc. The simulation results are very useful to design a mescochronous synchronizer for NoC.

• Journal of the Korean Institute of Intelligent Systems
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• v.15 no.6
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• pp.661-667
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• 2005

In this paper, we propose a new hybrid genetic algorithm for sequential ordering problem (SOP). In the proposed genetic algorithm, the Voronoi quantized crossover (VQX) is used as a crossover operator and the path-preserving 3-Opt is used as a local search heuristic. VQX is a crossotver operator that uses the epistasis information of given problem instance. Since it is a crossover proposed originally for the traveling salesman problem (TSP), its application to SOP requires considerable modification. In this study, we appropriately modify VQX for SOP, and develop three algorithms, required in the modified VQX, named Feasible solution Generation Algorithm, Precedence Cycle Decomposition Algorithm, and Genic Distance Assignment Method. The results of the tests on SOP instances obtained from TSPLIB and ZIB-MP-Testdata show that the proposed genetic algorithm outperforms other genetic algorithms in stability and solution quality.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.41 no.5
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• pp.165-173
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• 2004

Since the conventional image segmentation methods using mathematical morphology tend to yield over-segmented results, they normally need postprocess which merges small regions to obtain larger ones. To solve this over-segmentation problem without postprocess had to increase size of structuring element used marker extraction. As size of structuring element is very large, edge of region segments incorrectly. Therefore, this paper selectively applies structuring element of mathematical morphology to improve performance of image segmentation and classifies input image into texture region, edge region and simple region using averaged local variance and image gradient. Proposed image segmentation method removes the cause for over-segmentation of image as selectively applies size of structuring element to each region. Simulation results show that proposed method correctly segment for pixel region of similar luminance value and more correctly search texture region and edge region than conventional methods.

• Atmosphere
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• v.25 no.3
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• pp.529-541
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• 2015

Korea Institute of Atmospheric Prediction System (KIAPS) has been developing a global numerial prediction model and data assimilation system. We has implemented LETKF (Local Ensemble Transform Kalman Filter, Hunt et al., 2007) data assimilation system to NCAR CAM-SE (National Center for Atmospheric Research Community Atmosphere Model with Spectral Element dynamical core, Dennis et al., 2012) that has cubed-sphere grid, known as the same grid system of KIAPS Integrated Model (KIM) now developing. In this study, we have assimilated Global Positioning System Radio Occultation (GPS-RO) bending angle measurements in addition to conventional data within ensemble-based data assimilation system. Before assimilating bending angle data, we performed a vertical unit conversion. The information of vertical localization for GPS-RO data is given by the unit of meter, but the vertical localization method in the LETKF system is based on pressure unit. Therefore, with a clever conversion of the vertical information, we have conducted experiments to search for the best vertical localization scale on GPS-RO data under the Observing System Simulation Experiments (OSSEs). As a result, we found the optimal setting of vertical localization for the GPS-RO bending angle data assimilation. We plan to apply the selected localization strategy to the LETKF system implemented to KIM which is expected to give better analysis of GPS-RO data assimilation due to much higher model top.

• Journal of Korea Spatial Information System Society
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• v.8 no.3
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• pp.89-103
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• 2006

Location-Based Services(LBS) has been varied and expanded rapidly in local and overseas markets due to technology developments and expanded applications of wireless internet. Location Based Alert Service(LBA) capable of automatically furnishing data when entering or outing a specific location is expected to become one of the most important services in LBS. For LBA operation, it is essential to periodically get location information about moving object. However, this can cause a serious system load because system should continuously and largely receive location information of many moving objects. Existing and current methods for location polling of moving object are not suitable for an efficient location acquisition and a search structure required for LBA. In this study, to acquire large-scaled location information for LBA, a MDR moving object location polling algorithm will be suggested to reduce unnecessary location information and decrease system load by using mobility patterns of moving object.