• Journal of Hospice and Palliative Care
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• v.2 no.2
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• pp.114-124
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• 1999

Purpose : To clarify the relation between psychosocial variables and cancer in Korea. Methods : Case-control study. Participants: 239 subjects in 2 university hospitals in Seoul completed a series of psychometric instruments(the Olson's FACES III and the Lee's 98-items life event scale). Results : In bivariable analysis, there were statistically significant difference in age and economic status(income): marginal significance in education status and marital status between the cases and controls. The family function type and stress score were not significantly different. The result of multivariable logistic regression, analysis showed that the risk of cancer was associated with economic status and marital status, but neither the family function nor the life event stress. Conclusion : In this study, we cannot prove the statistical association between the family function, life event stress and cancer. It is necessary to persevere in our efforts to clarify the relation between stress and disease and to develop the useful tools to measure the Korean family function and life event stress.

• The Korean Journal of Nuclear Medicine Technology
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• v.22 no.1
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• pp.15-22
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• 2018

Purpose Respiratory motion during PET/MRI acquisition may result in image blurring and error in measurement for volume and quantification of lesion. The aim of this study was to evaluate changes of quantitative accuracy, tumor size and image quality by applying MR based respiratory motion correction technique (MBRMCT) using integrated PET/MR scanner. Materials and Methods Data of 30 patients (aged $62.5{\pm}10.2y$) underwent $^{18}F-FDG$ liver PET/MR (Biograph mMR 3.0T, Siemens) study were collected. PET listmode data for 7 minutes was simultaneously acquired with maximum average gate (MAG), minimum time gate (MTG) and non gate (NG) T1 weighted MR images. Gated PET reconstruction was performed using mu-maps generated from MAG and MTG by setting 35% of efficiency window. Maximum SUV ($SUV_{max}$), peak SUV ($SUV_{peak}$), tumor size and full width at half maximum (FWHM) in the z-axis direction of MAG, MTG and NG PET images were evaluated. Results Compared to NG, mean $SUV_{max}$ and $SUV_{peak}$ were increased in MAG 13.15%(p<0.0001), 8.66%(p<0.0001), MTG 13.27%(p<0.0001), 8.80%(p<0.0001) and mean tumor size and FWHM were decreased in MAG 14.47%(p<0.0001), 15.49%(p=0.0004), MTG 14.89%(p<0.0001), 15.79%(p=0.0003) respectively. Mean $SUV_{max}$ and $SUV_{peak}$ of MTG were increased by 0.07%(p=0.8802), 0.13%(p=0.7766). Mean tumor size and FWHM of MTG were decreased by 0.49%(p=0.2786), 0.36%(p=0.2488) compared to MAG. There was no statistically significant difference between MAG and MTG which increase total scan time for about 7 and 2 minutes. Conclusion SUV, accuracy of tumor size and spatial resolution were improved in both of MAG and MTG by applying MBRMCT without installing additional hardware in liver PET/MR study. More accurate information can be provided with the increase of 2 minutes scan time if applying MTG of MBRMCT to various abdominal PET/MR studies affected by respiratory motion.

• Korean Journal of Remote Sensing
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• v.33 no.5_1
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• pp.469-480
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• 2017

This study aims to understand the relationship between lineaments and epicenters in Geochang region, Gyungsangnam-do, South Korea. An instrumental observation of earthquakes has been started by Korea Meteorological Administration (KMA) since 1978 and there were 6 earthquakes with magnitude ranging 2 to 2.5 in Geochang region from 1978 to 2016. Lineaments were extracted from LANDSAT 8 satellite image and shaded relief map displayed in 3-dimension using Digital Elevation Model (DEM). Then, lineament density was statistically examined by hotspot analysis. Hexagonal grids were generated to perform the analysis because hexagonal pattern expresses lineaments with less discontinuity than square girds, and the size of the grid was selected to minimize a variance of lineament density. Since hotspot analysis measures the extent of clustering with Z score, Z scores computed with lineaments' frequency ($L_f$), length ($L_d$), and intersection ($L_t$) were used to find lineament clusters in the density map. Furthermore, the Z scores were extracted from the epicenters and examined to see the relevance of each density elements to epicenters. As a result, 15 among 18 densities,recorded as 3 elements in 6 epicenters, were higher than 1.65 which is 95% of the standard normal distribution. This indicates that epicenters coincide with high density area. Especially, $L_f$ and $L_t$ had a significant relationship with epicenter, being located in upper 95% of the standard normal distribution, except for one epicenter in $L_t$. This study can be used to identify potential seismic zones by improving the accuracy of expressing lineaments' spatial distribution and analyzing relationship between lineament density and epicenter. However, additional studies in wider study area with more epicenters are recommended to promote the results.

• Journal of the Earthquake Engineering Society of Korea
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• v.13 no.6
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• pp.27-37
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• 2009

A method of instrumentally estimating seismic intensity (MMI) based on the Fourier Acceleration Spectrum of earthquake ground-motion, the so-called 'FAS MMI method' of Sokolov and Wald (2002), was evaluated for its applicability to Korea based on the empirical models of mean (m) and standard deviation (${\sigma}$) for Korea according to individual seismic intensity for MMI ${\leq}$ IV (Yun et al., 2009). This evaluation showed that the error in estimating the seismic intensity using the FAS MMI method is ${\sigma}$ = 0.74 MMI, and was further reduced to ${\sigma}$ = 0.61 MMI if the dependency of the error on earthquake magnitude and distance is additionally corrected. It is also shown that FAS MMI based on the FAS semi-empirically evaluated from small earthquakes for damaging earthquakes in Korea with maximum MMI ${\geq}$ VI could predict the observed MMI with the maximum error of 0.63 by using the combined FAS m-${\sigma}$ models of Korea for MMI ${\leq}$ IV and global region for MMI ${\geq}$ V.

• Informatization Policy
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• v.27 no.3
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• pp.39-55
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• 2020

This study was designed to analyze the relationship among the motivations for the use of digital devices, attitudes toward the use of digital devices and performance resulting from the use of digital devices in middle-aged and elderly groups by using a path analysis. For an empirical analysis, the 2018 Survey on the Digital Divide by the National Information Society Agency was referenced, analyzing the data of 1,664 people, selected through listwise deletion from total 2,303 people aged 55 or over. A close examination of how measuring variables reflect potential variables (motivations for, attitudes toward and performance resulting from the use of digital devices) showed a significance of 0.001, which suggests that each individual measuring variable does reflect the potential variables. Evaluation of the pathway factors of the structural model from the motivations for the use of digital devices to the attitudes toward the use of digital devices (β=0.847) and from the attitudes toward the use of digital devices to the performance resulting from the use of digital devices (β= 0.745) revealed significant statistical effects. The results of this study suggest that the motivations for the use of digital devices does not directly enhance the digital device use performance, but that it can improve the attitudes toward the use of digital devices, which can in turn increase the performance resulting from the use of digital devices. The analysis holds significance that it has presented practical and policy implications.

• Korean Journal of Weed Science
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• v.18 no.4
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• pp.348-355
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• 1998

This study was conducted to identify allelopathic compounds in rye and oat straw extracts by HPLC analysis. These extracts were analyzed with 12 standard chemicals including salicylic acid. 11 chemicals in rye extract except for naringin and in oat extract except for catechin were identified. Salicylic acid(8.34mg/g) in rye straw extracts and naringin(7.50mg/g) in oat straw extracts among these standard chemicals were identified as the largest amount substance. The germination of Chenopodium ablum seeds was significantly inhibited by these chemicals at $10^{-3}$ and $10^{-4}M$ concentrations as compared to control. Salicylic acid in rye and naringin in oat were considered as the major allelopathic substances although allelopathy may be caused by an interaction of many substances. Yet many unidentified chemical compounds are present in both extracts.

• Journal of the Korean Geotechnical Society
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• v.21 no.9
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• pp.65-75
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• 2005

Maximum shear modulus of soil is a principal parameter for the design of earth structures under static and dynamic loads. In this study, the statistical data of maximum shear moduli of silty sands in Songdo area in the west coast of Korea evaluated by various field and laboratory tests - standard penetration test (SPT), cone penetration test (CPT), self-boring pressuremeter test (SBPT), downhole test (DH), seismic cone penetration test (SCPT) and resonant column test (RC) were analyzed. Based on the measurement of shear moduli using DH which is known as maximum value at very small strain, the new empirical correlations between shear moduli and SPT or CPT values were proposed. Predictions of maximum shear moduli using the proposed correlations were compared with the data obtained from DH. The good agreement confirmed that the proposed correlations reasonably predicted the maximum shear moduli of silty sands in the area.

• Journal of the Korean Society of Food Science and Nutrition
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• v.24 no.6
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• pp.887-891
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• 1995

Nutrient intake data collected by both dietary methods of the 24 hour recall method and the food frequency method from 538 middle school students were analysed to investigate any measurement errors occuring while using these methods. Measurement errors were observed both in terms of differences of average intake and consistancy from the two sources of data used. Wilcoxon signed ranks test was used to test the differences between the two average intakes and Speraman's rank order correlation coefficient was used to test consistancy. As a result, average intake value estimated from the food frequency method tended to be higher than that from the 24 hour recall method. The degree of overestimation varies from one nutrient to another. For instance, carotene showed not only the most significant differences in average intake but also showed the most incoisistancies between the two sets of data. This may imply the validity of nutrient intake as derived from different dietary survey methods varied from one nutrient to another, therefore the selection of dietary survey methods has to be made more cautiously in the case of certainnutrients.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.31 no.2
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• pp.199-209
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• 1995

From the results of model tests, statistical regression analysis of EHP estimation based on hull form parameters is adopted in this study. From this result, the method for estimation of EHP at the initial design stage of fishing boats is developed. This method is applied to four standard fishing boats with chine lines and two standard fishing boats with round bottom. The EHP's are estimated and compared to experimental results. In the case of six fishing boats, the estimated EHP corresponds well and approximates well with experimental results through out all the range tested. From these results it can be concluded that this numerical method is very efficient in estimating EHP of fishing boats having chine line and round bottom. Therefore, by applying the proposed method to design of fishing boats, we can improve the resistance characteristics. Further, this method can contribute to reduction of design time and thus down the total expenses.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.6
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• pp.460-471
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• 2019

The aim of this study was to examine the scale and market share of Chinese's research facility & equipment in the domestic research equipment market of basic and analytical science field for analyzing the difference of the number and amount of construction by year of acquisition, national research facility equipment standard classification code, and type of institution based on the information of the research equipment invested by the Korean government for the past 14 years. In addition, we analyzed the correlation among the year of acquisition, equipment standard classification code, and type of institution variables. As of January 1 2019, from 2005 to 2018, 50 Chinese's research facilities & equipments (main equipment with a construction cost of 30 million won or more) built in the basic and analytical science fields were selected for this study and their number of construction, amount of construction, year of acquisition, type of institution, and standard classification code were analyzed. Differences of the number and amount of construction with-in and by year of acquisition, standard classification code, and type of institution were tested using a single sample Chi-square test, Mann-Whitney U test, and Kruskal-wallis test. The correlation among the three variables was analyzed by using the Chi-square test of cross-tabulation analysis. And there was a statistically significant correlation among the year of acquisition, standard classification code, and type of institution (p<.05). Compared to the 2000s, in the 2010s, high-priced Optical Electronics/Video Equipment was installed at private universities, private enterprises, and government-affiliated research institute. Therefore, the domestic construction status of Chinese's research facility & equipment in the basic science and analytical science field is less than that of the domestic ones, but the number and the amount of construction are increasing statistically. So it is necessary for the government to be able to recognize the possibility that the Chinese's research facility and equipment can encroach on the domestic research industry market and to prepare related provision.