• Korean Journal of Soil Science and Fertilizer
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• v.43 no.6
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• pp.954-961
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• 2010

Ground-based remote sensing can be used as one of the non-destructive, fast, and real-time diagnostic tools for quantifying yield, biomass, and nitrogen (N) stress during growing season. This study was conducted to assess biomass and nitrogen (N) status of paddy rice (Oryza sativa L.) plants under N stress using passive and active ground-based remote sensors. Nitrogen application rates were 0, 70, 100, and 130 kg N $ha^{-1}$. At each growth stage, reflectance indices measured with active sensor showed higher correlation with DW, N uptake and N concentration than those with the passive sensor. NIR/Red and NIR/Amber indices measured with Crop Circle active sensors generally had a better correlation with dry weight (DW), N uptake and N content than vegetation indices from Crop Circle passive sensor and NDVIs from active sensors. Especially NIR/Red and NIR/amber ratios at the panicle initiation stage were most closely correlated with DW, N content, and N uptake. Rice grain yield, DW, N content and N uptake at harvest were highly positively correlated with canopy reflectance indices measured with active sensors at all sampling dates. N application rate explains about 91~92% of the variability in the SI calculated from NIR/Red or NIR/Amber indices measured with Crop Circle active sensors on 12 July. Therefore, the in-season sufficiency index (SI) by NIR/Red or NIR/Amber index from Crop Circle active sensors can be used for determination of N application rate.

• Korean Journal of Soil Science and Fertilizer
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• v.42 no.1
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• pp.21-28
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• 2009

Detailed information on soil characteristics is of great importance for the use and conservation of soil resources that are essential for human welfare and ecosystem sustainability. This paper introduces soil inventory of Korea focusing on national soil database establishment, information systems, use, and future direction for natural resources management. Different scales of soil maps surveyed and soil test data collected by RDA (Rural Development Administration) were computerized to construct digital soil maps and database. Soil chemical properties and heavy metal concentrations in agricultural soils including vulnerable agricultural soils were investigated regularly at fixed sampling points. Internet-based information systems for soil and agro-environmental resources were developed based on 'National Soil Survey Projects' for managing soil resources and for providing soil information to the public, and 'Agroenvironmental Change Monitoring Project' to monitor spatial and temporal changes of agricultural environment will be opened soon. Soils data has a great potential of further application in estimation of soil carbon storage, water capacity, and soil loss. Digital mapping of soil and environment using state-of-the-art and emerging technologies with a pedometrics concept will lead to future direction.

• Korean Journal of Soil Science and Fertilizer
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• v.43 no.6
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• pp.968-974
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• 2010

We assessed the feasibility of discrete wavelet transform (DWT) applied for the spectral processing to enhance the estimation performance quality of soil organic matters using visible-near infrared spectra and mapped their distribution via block Kriging model. Continuum-removal and $1^{st}$ derivative transform as well as Haar and Daubechies DWT were used to enhance spectral variation in terms of soil organic matter contents and those spectra were put into the PLSR (Partial Least Squares Regression) model. Estimation results using raw reflectance and transformed spectra showed similar quality with $R^2$ > 0.6 and RPD> 1.5. These values mean the approximation prediction on soil organic matter contents. The poor performance of estimation using DWT spectra might be caused by coarser approximation of DWT which not enough to express spectral variation based on soil organic matter contents. The distribution maps of soil organic matter were drawn via a spatial information model, Kriging. Organic contents of soil samples made Gaussian distribution centered at around 20 g $kg^{-1}$ and the values in the map were distributed with similar patterns. The estimated organic matter contents had similar distribution to the measured values even though some parts of estimated value map showed slightly higher. If the estimation quality is improved more, estimation model and mapping using spectroscopy may be applied in global soil mapping, soil classification, and remote sensing data analysis as a rapid and cost-effective method.

• Korean Journal of Soil Science and Fertilizer
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• v.40 no.6
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• pp.435-441
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• 2007

Ground-based optical sensing over the crop canopy provides information on the mass of plant body which reflects the light, as well as crop nitrogen content which is closely related to the greenness of plant leaves. This method has the merits of being non-destructive real-time based, and thus can be conveniently used for decision making on application of nitrogen fertilizers for crops standing in fields. In the present study relationships among leaf nitrogen content of rice canopy, crop growth status, and Normalized Difference Vegetation Index (NDVI) values were investigated. We measured Green normalized difference vegetation index($gNDVI=({\rho}0.80{\mu}m-{\rho}0.55{\mu}m)/({\rho}0.80{\mu}m+{\rho}0.55{\mu}m)$) and NDVI($({\rho}0.80{\mu}m-{\rho}0.68{\mu}m)/({\rho}0.80{\mu}m+{\rho}0.68{\mu}m)$) were measured by using two different active sensors (Greenseeker, NTech Inc. USA). The study was conducted in the years 2005-06 during the rice growing season at the experimental plots of National Institute of Agricultural Science and Technology located at Suwon, Korea. The experiments carried out with randomized complete block design with the application of four levels of nitrogen fertilizers (0, 70, 100, 130kg N/ha) and same amount of phosphorous and potassium content of the fertilizers. gNDVI and rNDVI increased as growth advanced and reached to maximum values at around early August, G(NDVI) were a decrease in values of observed with the crop maturation. gNDVI values and leaf nitrogen content were highly correlated at early July in 2005 and 2006. On the basis of this finding we attempted to estimate the leaf N contents using gNDVI data obtained in 2005 and 2006. The determination coefficients of the linear model by gNDVI in the years 2005 and 2006 were 0.88 and 0.94, respectively. The measured and estimated leaf N contents using gNDVI values showed good agreement ($R^2=0.86^{***}$). Results from this study show that gNDVI values represent a significant positive correlation with leaf N contents and can be used to estimate leaf N before the panicle formation stage. gNDVI appeared to be a very effective parameter to estimate leaf N content the rice canopy.

• Korean Journal of Psychosomatic Medicine
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• v.24 no.1
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• pp.83-93
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• 2016

Objectives : The Center for Epidemiologic Studies Depression scale-Revised is a recently revised scale which has been reported as a valid tool for the assessment of depressive symptoms. It encompasses cardinal symptoms of depression described in the Diagnostic and Statistical Manual of Mental disorders, fourth edition. In this study, we assessed the reliability, validity and psychometric properties of the Korean version of the CESD-R(K-CESD-R). Methods : Forty-eight patients diagnosed as major depressive disorder, dysthymia, depressive disorder NOS according to the DSM-IV criteria using Mini International Neuropsychiatric Interview and 48 healthy controls were enrolled in this study. They were assessed with K-CESD-R, K-MADRS, PHQ-9, KQIDS-SR, STAI to check cross-validation. Statistical analyses were performed using calculation of Cronbach's alpha, Pearson correlation coefficient, Principal Component Analysis, ROC curve and optimal cut-off value. Results : The Cronbach's alpha of K-CESD-R was 0.98. The total score of K-CESD-R revealed significantly high correlations with those of K-MADRS, PHQ-9, KQIDS-SR(r=0.910, 0.966 and 0.920, p<0.001, respectively). Factor analysis showed two factors account for 76.29% of total variance. We suggested the optimal cut-off value of K-CESD-R as 13 according to analysis of the ROC curve which value sensitivity and specificity both equally. Conclusions : These Results showed that the K-CESD-R could be a reliable and valid scale to assess depressive symptoms. The K-CESD-R is expected as a useful and effective tool for screening and measuring depressive symptoms not only in outpatient clinic but also epidemiologic studies.

• Journal of Food Hygiene and Safety
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• v.36 no.5
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• pp.400-406
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• 2021

The purpose of this study was to evaluate the microbial contamination level of Korean traditional rice cakes (Garaetteok, Injeolmi, Gyeongdan), as well as manufacturing environment of small-sized businesses in Korea. The contamination levels of total aerobic bacteria, coliforms, and Bacillus cereus in raw materials were 3.76-4.48, 2.21-4.14, and 1.02-1.15 log CFU/g respectively. On the other hand, Escherichia coli was not found. It has been found that the contamination level of total aerobic bacteria, coliforms, and B. cereus in the raw material decreased after the washing process, but it increased again during the soaking and grinding process. However, after the steaming stage, the contamination level increased again during the molding and cooling process, suggesting the need to take cautions in managing cooling water and molded rice cakes in the process. These results suggest that the safe management of cooling water and taking cautions in the drying process after steaming of rice cakes are necessary for controlling cross-contamination. No E. coli was detected during the manufacturing process involving all tested rice cakes. The microbial contamination level of manufacturing environment such as rice grinder and rice cake forming machine was high. Therefore, in terms of food safety strategy, it is necessary to consider introducing systematic cleansing and disinfection procedure to processing equipment and environment for the sake of reducing microbiological risks.

• Journal of the Korean Society of Radiology
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• v.15 no.5
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• pp.629-636
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• 2021

The purpose of this study was to identify the effects of mammo pad made of different kinds of materials on the reduced inconvenience and compression pains of patients to examine plausible interchangeability of existing pads made of single kind of material, and to examine the changes in pains of patients taking mammography and various factors therein. The high-hardness and highly-elastic mammo pressure pads, capable of replacing existing mammo pad of "H" company, were manufactured, and the display quality of mammography obtained from respective mammo pad were compared to each other to appraise the availability of manufactured mammo pad. In addition, 200 patients, who came to a general hospital in Seoul, were selected as subjects for the survey employing a questionnaire which was distributed to the subjects from December 2018 to March 2020 to identify the factors involved with the mammo pad of patients while taking mammography. The results of mammography obtained from both of the existing and newly manufactured mammo pad revealed appropriate display qualities fell within the range of clinical criteria. Besides, the factors associated with changing compression pains of patients taking mammography were analyzed wherefrom the general factors in the following order of age, height, and BMI index appeared, while the experiential and female factors appeared as in the following order: presence of menstruation, experience of child-birth, experience of breast feeding, menopause, grade of breast, shape of breast, and experience of mammography. In conclusion, the following factors comprising the age, experience of breast feeding, experience of mammography, and menopause rendered approximately 54% of power of explaining the degree of changing pains during mammography. Regarding the changes in compression pains while taking mammography, the increasing experience of mammography of patients rendered approximately 0.26 times more at the intermediate range of compression pains and approximately 0.14 times more at the range of severe pains.

• Journal of Bio-Environment Control
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• v.30 no.4
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• pp.367-376
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• 2021

Strawberry cultivation in Korea is grown in greenhouse, but most farms manage their water supply using a timer control method based on the experience of growers. The timer control has problems in that it is difficult to consider the weather condition, the growth stage of crops, and the moisture content of the substrate, so that the crops cannot be managed at an optimal level, and the accuracy of cultivation management are lacking. The watering methods using integrated solar irradiance and substrate moisture contents are control systems that provide eco-friendly and precise water supply considering the growth conditions of crops. The purpose of this study was to compare the combined water supply control with integrated solar irradiance and substrate moisture contents and timer control method in hydroponic cultivation of strawberries using coir, and to set the optimal integrated solar irradiance level for complex water supply control. The irrigation system was automatically watered when it reached 100, 150, 250 J·cm^-2 based on the external solar irradiance, and forced irrigation was performed at a substrate moisture content of less than 60% in all treatments. The amount of irrigation at once was 50 mL. The timer treatment was applied as a control. The smaller the level of integrated radiation to start watering, the greater the daily amount of irrigation. Both the fresh weight and dry weight per plant were higher in the complex irrigation control method than the timer control, and the 100 and 150 J·cm^-2 treatment had the highest fresh weight, and the 100 J·cm^-2 treatment showed a significantly higher dry weight. The yield was also significantly higher in the complex control method than in the timer, and the early yield increased as the level of integrated solar irradiance was smaller. The fresh weight of fruit was the lowest in the timer-controlled irrigation. As a result of this study, the possibility of combined control irrigation method using integrated solar irradiance and substrate moisture content was confirmed for precise water supply management of strawberries in hydroponics.

• MISULJARYO - National Museum of Korea Art Journal
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• v.99
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• pp.30-49
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• 2021

Scholar Byeoksu in a Pavilion by An Jung-sik (1861-1919; sobriquet: Simjeon) was first shown to the public in the exhibition Art of the Korean Empire: The Emergence of Modern Art at the National Museum of Modern and Contemporary Art, Deoksugung. This painting bears poems and inscriptions composed by Kim Taek-yeong (1850-1927; sobriquet: Changgang) and written by Kwon Dong-su (1842-?; sobriquet: Seokun). A rare example of an actual-view landscape painting by An Jung-sik, this painting is significant in that it depicts upper-class houses in Seoul in the early twentieth century. More importantly, it demonstrates an association among intellectuals of the time. Yun Deok-yeong (1873-1940; sobriquet: Byeoksu), who asked An Jung-sik to create this painting, was an uncle of Empress Sunjeonghyo (1894-1966), the consort of Emperor Sunjong. He was one of the most prominent collaborators who promoted the Japanese colonization of Korea. When Emperor Sunjong bestowed Yun Deok-yeong with a hanging board with an inscription reading "Scholar Byeoksu in a Pavilion," Yun requested the production of this painting to mark the event. Kim Taek-yeong, a master of Chinese literature during the late Korean Empire period, sought asylum in Nantong, Jiangsu Province in China with his family a month before the Protectorate Treaty was signed between Korea and Japan in 1905. In 1909, he returned to Korea. His decision to return was greatly influenced by Yun Deok-yeong and Yi Jae-wan (1855-1922). Upon his return, Kim Taek-yeong intended to gather materials for publishing a history book. Also, Kim continuously met his old acquaintances, made new friends, and socialized with them. He built relationships with people from various backgrounds, including those living in regions like Gurye, and even in other countries like Japan. This indicates that intellectuals of the time were still forming networks through poems and prose regardless of their political inclination, social rank, or nationality. Scholar Byeoksu in a Pavilion is of great value in that it shows an aspect of the intellectual exchanges among the learned people of the late nineteenth and early twentieth centuries.

• Journal of agricultural medicine and community health
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• v.46 no.3
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• pp.162-170
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• 2021

Objectives: This study was carried out to understand the seroprevalence and risk factors for severe fever with thrombocytopenia syndrome (SFTS) among the Korea National Park Service (KNPS) workers. Methods: We used the stored serum samples (763) and survey results collected from the previous investigation on scrub typhus and Lyme disease among the KNPS workers during 2016-2017. The serum samples were analyzed by double-antigen sandwich enzyme-linked immunosorbent assay, which was used to test the total antibody including IgG and IgM. Results: The SFTS seroprevalence among the KNPS worrkers was 1.4%. In multivariate logistic analysis, the national park exploration programs (odds ratio, 3.48; 95% confidence interval, 1.01-12.01) was significantly associated with the seroprevalence of SFTS. Conclusion: This study was the first serological study of SFTS among forestry workers in South Korea. Although the KNPS workers are at a high-risk group of SFTS, the prevention activities related to the working environment and habit was insufficient. Thus, systematic prevention education and training for the KNPS workers need to be strengthened.