• Korean Journal of Soil Science and Fertilizer
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• v.40 no.6
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• pp.465-470
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• 2007

To evaluate the effect of companion plant (Phlox subulata and Glechoma hederacea var. longituba) on conservation of soil in slopped highland, coverage of crops and soil erosion were investigated with 3 different conditions. The coverage rate of Phlox subulata with Chinese cabbage cultivation was kept on approximately 100% from Chinese cabbage-transplanting to -harvest. The coverage rate of Glechoma hederacea var. longituba with Chinese cabbage cultivation was low at it's early stage, however, reached to approximately 100% at the time of Chinese cabbage harvest. In contrast, the coverage rate of Chinese cabbage cultivation without cover crop, and simultaneous transplanting with Chinese cabbage and cover crop were approximately 60%. Losses of soil and nitrate nitrogen were much lower in Phlox subulata with Chinese cabbage cultivation ($0.1{\sim}0.2ton\;ha^{-1}$, $0.2{\sim}0.4kg\;NO_3{^-}-N\;ha^{-1}$) than those in Chinese cabbage cultivation without cover crop ($20.8ton\;ha^{-1}$, $2.1kg\;NO_3{^-}-N\;ha^{-1}$), and simultaneous transplanting with Chinese cabbage and cover crop ($8.9{\sim}10.5ton\;ha^{-1}$, $1.5{\sim}2.2kg\;NO_3{^-}-N\;ha^{-1}$). Cover plants suppressed the weed occurrence up to about 70%. Live mulching with cover plants set a good effects on weed suppression and reduction of soil and nutrient loss. Therefore intercropping with Phlox subulata will make great contributions to soil conservation in Chinese cabbage cultivated highland.

• Therapeutic Science for Rehabilitation
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• v.11 no.2
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• pp.25-37
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• 2022

Objective : Through the bibliographic analysis method, the flow of research is grasped from a macroscopic point of view and the connection system of key words is conducted. The purpose of this is to provide basic data for conducting research on aging anxiety and lifestyle. Methods : Among the bibliographic analysis methods, a citation analysis method that identifies the association based on the number of citations and a simultaneous appearance word analysis method that identifies the association based on the number of keywords appeared was used. VOSviewer was used to cluster and chart the analyzed information. Results : The frequency of occurrence of papers by year showed a gradual increase until 2017 and a rapid increase from 2018. In the field of research paper study, research was most actively conducted in the field of psychiatry. In the citation analysis, the United States, Australia, and the United Kingdom showed high correlation with each other, and as a result of conducting simultaneous word analysis on major keywords, words with high association with aging anxiety were found to be depression. Conclusion : This study is meaningful in that it grasped the flow of aging anxiety and lifestyle research from a macroscopic point of view using a bibliographic analysis method. Based on this, it is expected to understand the importance of lifestyle from the preventive point of view of aging and to be used as basic data for intervention and related education.

• Journal of Industrial Convergence
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• v.21 no.1
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• pp.187-192
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• 2023

In this study, trends in ICT education were investigated by analyzing the frequency of appearance of keywords related to machine learning and using conversion of iteration correction(CONCOR) techniques. A total of 304 papers from 2018 to the present published in registered sites were searched on Google Scalar using "ICT education" as the keyword, and 60 papers pertaining to ICT education were selected based on a systematic literature review. Subsequently, keywords were extracted based on the title and summary of the paper. For word frequency and indicator data, 49 keywords with high appearance frequency were extracted by analyzing frequency, via the term frequency-inverse document frequency technique in natural language processing, and words with simultaneous appearance frequency. The relationship degree was verified by analyzing the connection structure and centrality of the connection degree between words, and a cluster composed of words with similarity was derived via CONCOR analysis. First, "education," "research," "result," "utilization," and "analysis" were analyzed as main keywords. Second, by analyzing an N-GRAM network graph with "education" as the keyword, "curriculum" and "utilization" were shown to exhibit the highest correlation level. Third, by conducting a cluster analysis with "education" as the keyword, five groups were formed: "curriculum," "programming," "student," "improvement," and "information." These results indicate that practical research necessary for ICT education can be conducted by analyzing ICT education trends and identifying trends.

• Journal of the Korean Data and Information Science Society
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• v.26 no.4
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• pp.857-864
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• 2015

By Wikipedia, data mining is the computational process of discovering patterns in huge data sets involving methods at the intersection of association rule, decision tree, clustering, artificial intelligence, machine learning. Clustering or cluster analysis is the task of grouping a set of objects in such a way that objects in the same group are more similar to each other than to those in other groups. The similarity measures being used in the clustering may be classified into various types depending on the characteristics of data. In this paper, we computed bounds for similarity measures based on the probabilistic interestingness measure with partially marginal probability such as Peirce I, Peirce II, Cole I, Cole II, Loevinger, Park I, and Park II measure. We confirmed the absolute value of Loevinger measure wasthe upper limit of the absolute value of any other existing measures. Ordering of other measures is determined by the size of concurrence proportion, non-simultaneous occurrence proportion, and mismatch proportion.

• Journal of the Korean earth science society
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• v.26 no.2
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• pp.149-159
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• 2005

Simultaneous observations of MODIS (Moderate-resolution Imaging Spectroradiometer) onboard the Aqua and Terra satellites and weather station at ground near the Inchon International Airport (37.2-37.7 N, 125.7-127.2 E) during the period from December 2002 to September 2004 have been utilized in order to analyze the characteristics of satellite-observed infrared (IR) and visible data under fog and clear-sky conditions, respectively. The differences $(T_{3.7-11})$ in brightness temperature between $3.75{\mu}m\;and\;11.0{\mu}m$ were used as threshold values for remote-sensing fog (or low clouds) from satellite during day and night. The $T_{3.7-11}$ value during daytime was greater by about 21 K when it was foggy than that when it was clear, but during nighttime fog it was less by 1.5 K than during nighttime clear-sky. The value was changed due to different values of emission of fog particles at the wavelength. Since the near-IR channel at $3.7{\mu}m$ was affected by solar and IR radiations in the daytime, both IR and visible channels (or reflectance) have been used to detect fog. The reflectance during fog was higher by 0.05-0.6 than that during clear-sky, and varied seasonally. In this study, the threshold values included uncertainties when clouds existed above a layer of fog.

• Journal of Korean Institute of Industrial Engineers
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• v.27 no.4
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• pp.413-423
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• 2001

Low back disorders (LBDs) are one of the most common and costly work-related musculoskeletal disorders. One of the major possible risk factors of LBDs is to work with static and awkward trunk postures, especially in a complex trunk posture involving flexion, twisting and lateral bending simultaneously. This study is to examine the effect of complex trunk postures on the postural stresses using a psychophysical method. Twelve healthy male students participated in an experiment, in which 29 different trunk postures were evaluated using the magnitude estimation method. The results showed that subjective discomfort significantly increased as the levels of trunk flexion, lateral bending and rotation increased. Significant interaction effects were found between rotation and lateral bending or flexion when the severe lateral bending or rotation were assumed, indicating that simultaneous occurrence of trunk flexion, lateral bending and rotation increases discomfort ratings synergistically. A postural workload evaluation scheme of trunk postures was proposed based on the angular deviation levels from the neutral position. Each trunk posture was assigned numerical stress index depending upon its discomfort rating, which was defined as the ratio of discomfort of a posture to that of its neutral posture. Four qualitative action categories for the stress index were also provided in order to enable practitioners to apply corrective actions appropriately. The proposed scheme is expected to be applied to several field areas for evaluating trunk postural stresses.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.60-60
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• 2017

It is important to measure the gas exchange activity of the crops in canopy scale to understand the process of biomass production and yield formation. Thermal imaging of the canopy surface temperature is a powerful tool to detect the gas exchange activity of the crop canopy. The simultaneous measurement of the canopy temperature and the meteorological data enables us to calculate the canopy diffusive conductance ($g_c$) based on the heat flux model (Monteith et al. 1973, Horie et al. 2006). It is, however, difficult to realize the long-term and continuous monitoring of $g_c$ due to the occurrence of the calculation error caused by the fluctuation of the environmental condition. This is partly because the model assumption is too simple to describe the meteorological and aerodynamic conditions of the crop canopy in the field condition. Here we report the novel method of the direct measurement of the aerodynamic resistance ($r_a$) of the crop canopy, which enables us the stable and continuous measurement of the gas exchange capacity of the crop plants. The modified heat balance model shows the improved performance to quantify $g_c$ under the fluctuating meteorological condition in the field. The relationship between $g_c$ and biomass production of rice and soybean varieties is also discussed in the presentation.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.26 no.11
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• pp.985-991
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• 2015

This paper proposes appropriate locations for site diversity to provide stable satellite communication service in Korea. For this purpose, we analyzed rainfall rate data measured by KMA for 5 years at 88 sites, and the variations of simultaneous occurrence of rainfall rate in pairs of sites using the correlation coefficient. This paper provided contour maps of the spatial ditstribution of rainfall rate correlation, and proposed information on the optimum sites/regions for the operation of muti-uplink satellite systems, in 4 cities which were principal in field of satellite communication in Korea.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.5
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• pp.1917-1921
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• 2012

Background: Colorectal cancer is one of the leading causes of mortality worldwide. Genome wide analysis studies have identified sequence mutations causing loss-of-function that are associated with disease occurrence and severity. Epigenetic modifications, such DNA methylation, have also been implicated in many cancers but have yet to be examined in the East Asian population of colorectal cancer patients. Methods: Biopsies of tumors and matched non-cancerous tissue types were obtained and genomic DNA was isolated and subjected to the bisulphite conversion method for comparative DNA methylation analysis on the Illumina Infinium HumanMethylation27 BeadChip. Results: Totals of 258 and 74 genes were found to be hyper- and hypo-methylated as compared to the individual's matched control tissue. Interestingly, three genes that exhibited hypermethylation in their promoter regions, CMTM2, ECRG4, and SH3GL3, were shown to be significantly associated with colorectal cancer in previous studies. Using heatmap cluster analysis, eight hypermethylated and 10 hypomethylated genes were identified as significantly differentially methylated genes in the tumour tissues. Conclusions: Genome-wide methylation profiling facilitates rapid and simultaneous analysis of cancerous cells which may help to identify methylation markers with high sensitivity and specificity for diagnosis and prognosis. Our results show the promise of the microarray technology in identification of potential methylation biomarkers for colorectal cancers.

• Journal of Korean Society of Rural Planning
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• v.26 no.1
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• pp.39-49
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• 2020

The study analyzed the frequency of simultaneous occurrence of keywords presented in a total of 805 papers published in domestic journals from 1995 to 2019 by social network analysis(SNS) method, and examined core keywords of each period(5 years), in order to understand the research trends of the rural residential environment. The main results are as follows. First, as a result of the analysis of centrality, 'Community', 'Tourism' and 'Comprehensive Rural Village Development Project' were the top 3 keywords. Second, examined by each period, the top keywords are 'Eco Friendly' in 2000~2004, 'Tourism' in 2005~2009 and 2010~2014, 'Community' in 2015~2019. Third, comparing the structural characteristics of core keywords 2nd, 3rd, and 4th period, a network centering on 'Tourism' was clearly formed in the 2nd period. 'Tourism' was divided into 'Community' and a movement to form a separate group appeared in the 3rd period. In the 4th period, 'Community' was found to form a network without direct connection with 'Tourism'. The results of this study suggest the trend change of viewpoint for the rural area in the domestic research on rural residential environment. It has been confirmed that while the research had been carried out with the viewpoint of rural area as a 'tourist attraction' or 'sightseeing spot' for the urban citizens until the mid-2010s, in the research of late 2010s the viewpoint has settled down as a 'residential space' or 'space for new economic activities' of a variety of rural residents.