• 한국공간정보시스템학회:학술대회논문집
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• 2007.06a
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• pp.139-144
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• 2007

Recording data in hundreds of narrow contiguous spectral intervals, hyperspectral images have provided the opportunity to detect small differences in material composition. But a limitation of a hyperspectral image is the signal to noise ratio (SNR) lower than that of a multispectral image. This paper presents the efficiency of Spectral Similarity Scale (SSS) in change detection of hyperspectral image and the experiment was performed with Hyperion data. SSS is an algorithm that objectively quantifies differences between reflectance spectra in both magnitude and direction dimensions. The thresholds for detecting the change area were determined through Expectation-Maximization (EM) algorithm. The experimental result shows that the SSS algorithm and EM algorithm are efficient enough to be applied to the unsupervised change detection of hyperspectral images.

• The Bulletin of The Korean Astronomical Society
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• v.44 no.1
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• pp.43.2-43.2
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• 2019

In many astrophysical systems, smooth large-scale variations coexist with small-scale fluctuations. For example, a large-scale velocity or density gradient can exist in molecular clouds that have small-scale fluctuations by turbulence. In redshifted 21cm observations, we also have two types of signals - the Galactic foreground emissions that change smoothly and the redshifted 21cm signals that fluctuate fast in frequency space. In many cases, the large-scale variations make it difficult to extract information on small-scale fluctuations. We propose a simple technique to remove smooth large-scale variations. Our technique relies on multi-point structure functions and can obtain the magnitudes of small-scale fluctuations. It can also be used to design filters that can remove large-scale variations and retrieve small-scale data. We discuss how to apply our technique to irregularly spaced data, such as rotation measure observations toward extragalactic radio point sources.

• Journal of the Korean earth science society
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• v.32 no.6
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• pp.525-536
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• 2011

In any applications using various types of spatial data, it is very important to account for the scale differences among available data sets and to change the scale to the target one as well. In this paper, we propose to use a geostatistical downscaling approach based on vaiorgram deconvloution and block simulation to generate fine-scale categorical thematic maps from coarse-scale fraction data. First, an iterative variogram deconvolution method is applied to estimate a point-support variogram model from a block-support variogram model. Then, both a direct sequential simulation based on area-to-point kriging and the estimated point-support variogram are applied to produce alternative fine-scale fraction realizations. Finally, a maximum a posteriori decision rule is applied to generate the fine-scale categorical thematic maps. These analytical steps are illustrated through a case study of land-cover mapping only using the block fraction data of thematic classes without point data. Alternative fine-scale fraction maps by the downscaling method presented in this study reproduce the coarse-scale block fraction values. The final fine-scale land-cover realizations can reflect overall spatial patterns of the reference land-cover map, thus providing reasonable inputs for the impact assessment in change of support problems.

• Korean Journal of Culture and Social Issue
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• v.29 no.4
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• pp.595-616
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• 2023

The Critical Consciousness Scale (CCS) is a scale developed by Diemer and colleagues (2017) that can measure the capacity of the oppressed or marginalized people to critically analyze their social and political conditions, support societal equality, and take action to change the perceived inequities. In this study, we validated the CCS for Korea by adapting and localizing the scale and validating it among university students. Content validity was verified by having five individuals with master's and doctoral degrees in psychology evaluate the suitability of the translated items. Afterwards, reliability and validity were verified through a survey of 314 university students nationwide using the CCS, along with the opportunity inequality recognition scale, recognition of the need for environmental change scale, social participation scale, and belief in a just world scale. To verify the scale's validity, exploratory factor analysis was conducted, confirming three subfactors. Then, a confirmatory factor analysis was carried out, where 14 items out of the original 22 were retained. The construct validity and reliability of these 14 items were found to be satisfactory. Additionally, in the correlation analysis between the CCS and similar scales, a significant clear relationship was found. The CCS showed a positive correlation with scales such as opportunity inequality recognition, need for environmental change recognition, and social participation, and a negative correlation with the belief in a just world scale. Based on these results, the CCS can be considered valid and reliable. Finally, the limitations and significance of this study were discussed.

• Journal of the Korean Association of Geographic Information Studies
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• v.11 no.1
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• pp.116-124
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• 2008

This study presents the application of multi-temporal and multi-scale panchromatic aerial photos for change detection in a small urban area. For aerial photos of the scale of 1:20,000 taken in 1987 and 1996 and the scale of 1:37,500 taken in 2000. Pre-processing that make the same conditions to all of the aerial photos was carried out through geometric correction, registration, contrasting, resamplimg, and mosaicking and then change detection were carried out respectively by image differencing and image ratio techniques. As a result, the change of urban features and landcover were able to be detected from panchromatic aerial photos that is single-band images and then the detected change results were compared between both techniques.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.25 no.2
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• pp.521-533
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• 1995

This study was performed to develop and evaluate the method to detect Quantitatively the serial changes in the size of artificial lesion in the spongious bone by automatic color image analyzer. 15 intraoral radiograms taken before and after endodontic treatment of 5 cases were used for contour line analysis. 30 intraoral radiograms taken by geometrically standardized apparatus before and after serially the formation of artificial lesions of 0.80, 1.20, 1.75, 2.00mm in diameter at the periapical area and interdental area of spongious bone were used. The analysis of image according to the variance of lesion size by 0.25, 0.35, 0.55, and 0.85mm serially was performed by the histogram and the color enhancement with subtraction. The images inputted by CCDcamera were digitized and analyzed by NEXUS QUBE program with NEC PC-9801 computer. The obtained results were as follows: 1. There was no reliability in the analysis of lesions by contour line 2 .. The mean difference of the grey scale at each pixel was 1 step between reference image and the corrected images. 3. In the analysis by histogram of the artificial lesion in spongeous bone, the change over 0.55mm in the mesiodistal size was detectable by the change of the numbers of pixel showing the change in grey scale. 4. In the analysis by histogram of the artificial lesion in spongeous bone, the change over 0.25mm in the buccolingual size was detectable by the change in grey scale. 5. By color enbancement with- subtraction, each lesion was able to be isolated and the change in it's mesiodistal size was detectable visually , but not in it's buccolingual size.

• The Journal of Fisheries Business Administration
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• v.41 no.3
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• pp.21-44
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• 2010

The paper estimates changes in total factor productivity and technical efficiency change index and technical change index using Malmquist productivity index(MPI) in fisheries wholesale products over the time period of 2006 through 2008. The model considers a number of employees and operating costs as input factors, and sales and EBIT(earnings before tax and interest) as output factors. The results indicate that, between 2006 and 2007, there is in general technical progress in which TCI(Technical Change Index) indicates 2.7994 in the sale scale of 50 million won through 100 million won, while there are no efficiency in TECI(Technical Efficiency Change Index), PECI(Pure Efficiency Change Index) and SECI(Scale Efficiency Change Index) which are estimated to be around 1. Between 2007 and 2008 technical efficiency and technical progress are generally declined, compared to those of 2006 and 2007. Wilcoxon's rank-sum test shows that there are statistically significant difference of TCI and MPI between two periods at the level of 5%, while there are statistically significant difference of TECI, PECI and SECI between two periods at the level of 5%.

• International journal of advanced smart convergence
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• v.11 no.2
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• pp.171-184
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• 2022

The purpose of this paper is output oriented, in order to maximize the output level of sustainable development efficiency of foreign trade in western China with limited input. This paper adopts the relevant input-output indicators of sustainable foreign trade development of 11 provinces and cities in western China from 2016 to 2020, and uses DEA model to measure their technical efficiency, pure technical efficiency and scale efficiency. Malmquist index was used to calculate the total factor productivity change index of each province in western China from 2016 to 2020. We found that, on the whole, the average values of technical efficiency, pure technical efficiency and scale efficiency of provinces and cities in western China from 2016 to 2020 are greater than 0.8, indicating that the western region has high technical efficiency, relatively high management and institutional level and high existing scale level. Scale efficiency is lower than pure technical efficiency on the whole, indicating that the current sustainable development efficiency of foreign trade in western China is mainly limited by its scale level. The technological progress index is higher than the technological efficiency change index, indicating that the total factor productivity of the sustainable development of foreign trade in western China is mainly driven by technological progress and more influenced by external factors. We think the conclusion of this study can provide important reference information for the sustainable development of foreign trade of provinces and cities in western China.

• Journal of Acupuncture Research
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• v.39 no.3
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• pp.202-212
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• 2022

Background: The aim of this study was to evaluate the effectiveness and safety of Cheong-A-Won Gagambang (JCE003) treatment for degenerative knee osteoarthritis. Methods: This was a single-center, randomized, double-blind, placebo-controlled pilot clinical trial. There were 36 adults with degenerative knee osteoarthritis who were randomly allocated into JCE003 1,000 mg, JCE003 2,000 mg, or the placebo group (in a 1:1:1 ratio). The participants received 12 weeks of treatment and had scheduled tests every 6 weeks. The primary outcomes were measured using the Korean Western Ontario and McMaster Universities scale, and the secondary outcomes were measured using the visual analog scale, European quality of life-5-dimensions, patient global impression of change, C-reactive protein, and erythrocyte sedimentation rate. Changes between baseline scores and scores following study completion were analyzed. Results: There were 29 participants whose data were analyzed in this study. The change of Korean Western Ontario and McMaster Universities, visual analog scale, European quality of life-5-dimensions scores showed significant improvement in the JCE003 1,000 mg group. The change of patient global impression of change was significantly improved in the placebo group. There were 14 adverse events, but there was no clinically significant relationship with the intake of JCE003 compared with the placebo. Conclusion: Taking JCE003 may be effective at improving knee pain in patients with degenerative knee osteoarthritis and appears to be safe. Based on this study, the concentration and feasibility of the test group may be used when conducting a large-scale clinical trial of degenerative knee osteoarthritis in the future.

• Journal of Korea Port Economic Association
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• v.22 no.3
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• pp.59-78
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• 2006

The purpose of this paper is to analyze the trend on scale efficiency of the Port of Gwangyang from 1994 to 2004 using CCR, BCC, and Malmquist index approaches. The main results are as follows. first, scale efficiency shows a 50% similar [5(94/95, 95/96, 97/98, 2001/2002, 2003/2004) out of 10] pattern to technical efficiency change. Second, total factor productivity increased at 48.57% rate of growth on average in 6 out of 10 periods except 96/97, 97/98, 99/2000, and 2000/2001. 2003/2004 period is the one period experiencing rapid total factor productivity changes, mainly due to technical progress. Third, the ranking order of accumulative indices is scale efficiency change, TFP change, efficiency change, technical change, and pure efficiency change. The main policy implication of this paper is that according to the CCR, BCC, and Malmquist results, the Port of Gwangyang should develop the plan for enhancing the 5 Malmquist indices with following the management way of benchmarking ports.