• Journal of the Korean Data and Information Science Society
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• v.11 no.2
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• pp.189-199
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• 2000

A major deficiency of laboratory testing of rock structure is that the structures are limited in size and therefore present a very small and highly selective sample of the rock mass from which were removed. In a typical engineering project, the samples tested in the laboratory represent only a very small fraction of one percent of the volume of the rock mass. In this paper, we calculate the representative orientation of the resultant vector, the measure of the degree of clustering, the volume of rock mass, the trace length of discontinuity spacing under underlying distributions. And we generate the random fracture networks using real data. We propose the calculating the trace length.

• Nuclear Engineering and Technology
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• v.55 no.8
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• pp.2823-2834
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• 2023

Austenitic stainless steel welds (ASSWs) of nuclear components undergo aging-related degradations caused by high temperature and neutron radiation. Since irradiation leads to the change of material characteristics, relevant quantification is important for long-term operation, but limitations exist. Although ion irradiation is utilized to emulate neutron irradiation, its penetration depth is too shallow to measure bulk properties. In this study, a systematic approach was suggested to estimate mechanical properties of ion irradiated 308 ASSW. First of all, weld specimens were irradiated by 2 MeV proton to 1 and 10 dpa. Microstructure evolutions due to irradiation in δ-ferrite and austenite phases were characterized and micropillar compression tests were performed. In succession, dislocation density based stress-strain (S-S) relationships and quantification models of irradiation defects were adopted to define phases in finite element analyses. Resultant microscopic S-S curves were compared to verify material parameters. Finally, macroscopic behaviors were calculated by multiscale simulations using real microstructure based representative volume element (RVE). Validity of the approach was verified for the unirradiated specimens such that the estimated S-S curves and 0.2% offset yield strengths (YSs) which was 363.14 MPa were in 10% agreement with test. For irradiated specimens, the estimated YS were 917.41 MPa in 9% agreement.

• The Journal of Korean Association of Computer Education
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• v.8 no.1
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• pp.81-91
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• 2005

In this paper we present a novel approach for image retrieval using color and edge information. We take into account the HSI(Hue, Saturation and Intensity) color space instead of RGB space, which emphasizes more on visual perception. In our system colors in an image are clustered into a small number of representative colors. The color feature descriptor consists of the representative colors and their percentages in the image. An improved cumulative color histogram distance measure is defined for this descriptor. And also, we have developed an efficient edge detection technique as an optional feature to our retrieval system in order to surmount the weakness of color feature. During the query processing, both the features (color, edge information) could be integrated for image retrieval as well as a standalone entity, by specifying it in a certain proportion. The content-based retrieval system is tested to be effective in terms of retrieval and scalability through experimental results and precision-recall analysis.

• Journal of Korean Society on Water Environment
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• v.26 no.6
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• pp.943-947
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• 2010

Runoff ratio of paddy fields for the application of Event Mean Concentration (EMC) method was studied. To measure actual runoff ratio of paddy fields, a field monitoring was conducted for 2008 ~ 2009 period. Long-term rainfall data of four cities in major river basins were analyzed and weighting factors were developed to consider temporal and spatial variation of rainfall distribution of Korean peninsula. The observed runoff ratio ranged 0.00 ~ 1.20 and arithmetic mean were 0.25, respectively. However, the representative runoff ratio for paddy fields was determined as 0.41 according to the method suggested by National Institute of Environmental Research (NIER).

• Archives of design research
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• v.19 no.1 s.63
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• pp.191-200
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• 2006

A design representation is reflected in the typicality of branch representation as a syntagm in combination with design factors. And the design factors form up paradigm as an attributive category which is reflected object and value of branch representations, and they are consisted of selection and combination in representative process. Selection and combination of the design attributive category also reflect the representation consciousness of operating in representative process, and they imply a cognizance about object and value of the representation. Therefore, branch representation appears an attributive structure which is required of a given field by means of the representative object and value. This is made up of the divided differentiation according to a combined mode. This study is to investigate the fact verification between typicality of attributive structure and each divided differentiation to measure consideration degree of attributive category which is consisted in the design representation. The attributive structure of representation which is affected the industrial design, the visual communication design, and the environmental design fields identifies to take the typical differentiation by means of evaluations and results of this study.

• Journal of KIISE
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• v.43 no.1
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• pp.40-46
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• 2016

Digital road map generation is primarily based on artificial satellite photographing or in-site manual survey work. Therefore, these map generation procedures require a lot of time and a large budget to create and update road maps. Consequently, people have tried to develop automated map generation systems using GPS trajectory data sets obtained by public vehicles. A fundamental problem in this road generation procedure involves the extraction of representative trajectory such as main roads. Extracting a representative trajectory requires the base data set of piecewise line segments(GPS-trajectories), which have close starting and ending points. So, geometrically similar trajectories are selected for clustering before extracting one representative trajectory from among them. This paper proposes a new divide- and-conquer approach by partitioning the whole map region into regular grid sub-spaces. We then try to find similar trajectories by sweeping. Also, we applied the $Fr{\acute{e}}chet$ distance measure to compute the similarity between a pair of trajectories. We conducted experiments using a set of real GPS data with more than 500 vehicle trajectories obtained from Gangnam-gu, Seoul. The experiment shows that our grid partitioning approach is fast and stable and can be used in real applications for vehicle trajectory clustering.

• Journal of the Korean Geographical Society
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• v.40 no.3 s.108
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• pp.274-284
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• 2005

On the subject of Yeoungsan River Yeoungbon c and Seumjin River Seumbon e site discussing as the measuring points of discharge and Quality by the Department of Environment, this study executes the tests of proprieties and examines the methods of flow measuring and assessment. The result of this study may summarize as belows. According to the hydrogeomorphological aspects and artificial effects, Yeoungbon c and Seumbon e site are not proper for the measuring points of the water levels. Also, the methods of river discharge measuring by the specific discharge method, first tried in this study, has an enough reliability which can be used to measure the site where is difficult to measure the flow directly or to select the representative site to measure on the up and downstream. In case of accumulating the specific discharge data throughout the flow observation by seasons and periods for a long time, these may be used to measure the flow as well.

• The Journal of the Acoustical Society of Korea
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• v.27 no.3
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• pp.119-128
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• 2008

This paper analyzes the relationship between two representative statistical methods for bandwidth extension (BWE): Gaussian Mixture Model (GMM) and Hidden Markov Model (HMM) ones, and compares their performances. The HMM method is a memory-based system which was developed to take advantage of the inter-frame dependency of speech signals. Therefore, it could be expected to estimate better the transitional information of the original spectra from frame to frame. To verify it, a dynamic measure that is an approximation of the 1st-order derivative of spectral function over time was introduced in addition to a static measure. The comparison result shows that the two methods are similar in the static measure, while, in the dynamic measure, the HMM method outperforms explicitly the GMM one. Moreover, this difference increases in proportion to the number of states of HMM model. This indicates that the HMM method would be more appropriate at least for the 'blind BWE' problem. On the other hand, nevertheless, the GMM method could be treated as a preferable alternative of the HMM one in some applications where the static performance and algorithm complexity are critical.

• Journal of the Institute of Electronics Engineers of Korea TE
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• v.37 no.2
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• pp.41-53
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• 2000

In this paper, the Maekjin and the Yangdorak Diagnosis algorithm by using a neuro-fuzzy method is proposed and it is implemented on the DSP-based system. Maekjin is measured by 3-channels of the Maekjin board through Maekjin probe which is attached on Chon, Kwan and Chuk of patient's wrist. First, we experiment Chon, Kwan and Chuk, 3-parts simultaneously and second perform one part of Chon, Kwan and Chuk respectively, The experimental results show that the Maekjin signal is measured precisely with any Maekjin probe. In Yangdorak diagnosis, the pulse generated by electric stimulator stimulates a portion of body and the response signal is measured through electrodes which is attached on representative points of 12 kyungmaks. The experimental methods are (1) 1 channel-measure, (2) 2 channels-measure, (3) 6 channels-measure and (4) 24 channels-measure. A fuzzy diagnosis is performed and neural networks is learned using fuzzy values as inputs, and we show that neuro-fuzzy diagnosis method is performed well.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.20 no.5
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• pp.51-56
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• 2020

Measurement accuracy and required time is important to make ATE(Automatic test equipment) system in Ka band, and SCPI commands of power meter which is a representative RF test equipment are studied in this paper. Comparison data between FETCH and MEASURE which are SCPI commands are measured in 30 G ~ 31 GHz and -70 ~ +20 dBm using two power sensor. The data show that FETCH which is the fastest SCPI is able to get reliable data in linear interval above noise level. MEASURE which is the best accurate command takes longer time than FETCH, and the longest time is 13.2 seconds. These results offer that measurement accuracy and required time of the two SCPI for power meter and would be used as a guideline for efficient ATE system in Ka band.