• Journal of Fisheries and Marine Sciences Education
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• v.23 no.1
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• pp.67-74
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• 2011

The study was constructed an analysis of postures of a expert diver's wearing and taking off with skinscuba equipment using ergonomics tools(REBA, RULA, OWAS) for prevention of Musculoskeletal injuries. This survey is consisted of 4 postures in terms of wearing and taking off : Crouching(alone), Standing(alone), Helping of assistance, Using of stanchion. Their rate of injuries is getting higher due to instability postures, exposed dangers and excessive physical actions. So this study provides basic and educational information for prevention of that. The result is as follows : The result of crouching postures of wearing alone was REBA 9(Ac Level 3), RULA 7(Ac Level 4), OWAS AC 2, and crouching postures of taking off alone was REBA 12(Ac Level 4), RULA 7(Ac Level 4), OWAS AC 4. The result of standing postures of wearing alone was REBA 8(Ac Level 3), RULA 7(Ac Level 4), OWAS AC 3, and standing postures of taking off alone was REBA 8(Ac Level 3), RULA 7(Ac Level 4), OWAS AC 3. The result of helping of assistance postures of wearing was REBA 4(Ac Level 2), RULA 3(Ac Level 2), OWAS AC 2, and standing postures of taking off alone was REBA 4(Ac Level 2), RULA 4(Ac Level 2), OWAS AC 1. The result of using of stanchion postures of wearing was REBA 3(Ac Level 1), RULA 3(Ac Level 2), OWAS AC 1, and standing postures of taking off alone was REBA 3(Ac Level 1), RULA 3(Ac Level 2), OWAS AC 1. Especially both postures of wearing and taking off alone showed high results in the analysis of postures using ergonomics tools(REBA, RULA, OWAS).

• Journal of the Computational Structural Engineering Institute of Korea
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• v.36 no.3
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• pp.173-184
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• 2023

Presently, the general seismic fragility evaluation method for a bridge system composed of member elements with different nonlinear behaviors against strong earthquakes has been to evaluate at the element-level. This study aims to develop a system-level seismic fragility evaluation method that represents a structural system. Because the seismic behavior of bridges is generally divided into transverse and longitudinal directions, this study evaluated the system-level seismic fragility in both directions separately. The element-level seismic fragility evaluation in the longitudinal direction was performed for piers, bridge bearings, pounding, abutments, and unseating. Because pounding, abutment, and unseating do not affect the transverse directional damages, the element-level seismic fragility evaluation was limited to piers and bridge bearings. Seismic analysis using nonlinear models of various structural members was performed using the OpenSEES program. System-level seismic fragility was evaluated assuming that damage between element-levels was serially connected. Pier damage was identified to have a dominant effect on system-level seismic fragility than other element-level damages. In other words, the most vulnerable element-level seismic fragility has the most dominant effect on the system-level seismic fragility.

• Korean Journal of Soil Science and Fertilizer
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• v.51 no.1
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• pp.50-60
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• 2018

This study was to evaluate the effect of organic amendments incorporation on soil properties and plant growth under two different soil salinity levels and various cultivated crops at Saemangeum reclaimed tidal land for three years from 2012 to 2014. The soil texture of the experimental site was sandy loam. Four different crops, sesbania (Sesbania grandiflora), sorghum-sudangrass hybrid (Sorghum bicolor-Sorghum sudanense), rice (Oryza sativa L.) and barley (Hordeum vulgare) were cultivated at low (< $1dS\;m^{-1}$) and high (> $4dS\;m^{-1}$) soil salinity levels. The soil salinity was significantly lowered at the rice cultivation site compared to continuous upland crops cultivation site in high soil salinity level. But the soil salinity was increased as cultivating sesbania coutinuously in low soil salinity level. The soil organic matter content was increased with the incorporation of straw at the continuous site of rice and barley, and the average of soil organic matter was increased by $0.9g\;kg^{-1}$ per year which was effective in soil aggregate formation. The highest biomass yield plot was found in barley (high salinity level) and sesbania (low salinity level) cultivation site, respectively. Our research indicates that rice cultivation in paddy field with high salinity level was effective in lowering soil salinity and sesbania cultivation was useful to biomass production at upland with low salinity. In conclusion, soil salinity and organic matter content should be considered for multiple land use in newly reclaimed tidal land.

• Journal of Periodontal and Implant Science
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• v.41 no.2
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• pp.92-97
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• 2011

Purpose: The present study was performed to compare the treatment outcomes of non-surgical periodontal treatment according to the distribution of attachment loss of a given patient. Methods: Forty-five patients with moderate to severe periodontitis were divided in two subgroups; Group I patients with teeth manifesting attachment loss of ${\geq}$ 6 mm at one or more sites on the buccal/labial aspect while maintaining an attachment level ${\leq}$ 5 mm at the lingual/palatal aspect, Group II patients with teeth manifesting an attachment level ${\geq}$ 6 mm at more than one site on the lingual/palatal aspect while maintaining an attachment level ${\leq}$ 5 mm at the buccal/labial aspect. The probing pocket depth, probing attachment level, tooth mobility, and chewing discomfort were recorded at baseline and 6 months examinations following non-surgical periodontal therapy. Results: The buccal/ abial surfaces of teeth with moderate to severe periodontitis in Group I patients demonstrated a greater amount of pocket reduction, gain of attachment level, and tooth mobility reduction than the lingual/palatal aspects of teeth examined in Group II patients. Conclusions: Within the limits of the present study, the patients demonstrating attachment loss ${\geq}$ 6 mm at buccal/labial surfaces responded better to the nonsurgical periodontal therapy than those demonstrating comparable attachment loss at lingual/ palatal surfaces.

• Journal of Preventive Medicine and Public Health
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• v.47 no.2
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• pp.104-112
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• 2014

Objectives: To date, studies have not comprehensively demonstrated the relationship between stroke incidence and socioeconomic status. This study investigated stroke incidence by household income level in conjunction with age, sex, and stroke subtype in Korea. Methods: Contributions by the head of household were used as the basis for income levels. Household income levels for 21 766 036 people were classified into 6 groups. The stroke incidences were calculated by household income level, both overall within income categories and further by age group, sex, and stroke subtype. To present the inequalities among the six ranked groups in a single value, the slope index of inequality and relative index of inequality were calculated. Results: In 2005, 57 690 people were first-time stroke patients. The incidences of total stroke for males and females increased as the income level decreased. The incidences of stroke increased as the income level decreased in those 74 years old and under, whereas there was no difference by income levels in those 75 and over. Intracerebral hemorrhage for the males represented the highest inequality among stroke subtypes. Incidences of subarachnoid hemorrhage did not differ by income levels. Conclusions: The incidence of stroke increases as the income level decreases, but it differs according to sex, age, and stroke subtype. The difference in the relative incidence is large for male intracerebral hemorrhage, whereas the difference in the absolute incidence is large for male ischemic stroke.

• Korean Journal of Remote Sensing
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• v.37 no.1
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• pp.85-95
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• 2021

Recently, as data mining and artificial neural network techniques are developed, analyzing large amounts of data is proposed to reduce the dimension of the data. In general, empirical orthogonal function (EOF) used to reduce the dimension in the ocean data and recently, Self-organizing maps (SOM) algorithm have been investigated to apply to the ocean field. In this study, both algorithms used the monthly Sea level anomaly (SLA) data from 1993 to 2018 around the East Asia Coasts. There was dominated by the influence of the Kuroshio Extension and eddy kinetic energy. It was able to find the maximum amount of variance of EOF modes. SOM algorithm summarized the characteristic of spatial distributions and periods in EOF mode 1 and 2. It was useful to find the change of SLA variable through the movement of nodes. Node 1 and 5 appeared in the early 2000s and the early 2010s when the sea level was high. On the other hand, node 2 and 6 appeared in the late 1990s and the late 2000s, when the sea level was relatively low. Therefore, it is considered that the application of the SOM algorithm around the East Asia Coasts is well distinguished. In addition, SOM results processed by SLA data, it is able to apply the other climate data to explain more clearly SLA variation mechanisms.

• Journal of The Korean Society of Agricultural Engineers
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• v.63 no.1
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• pp.27-35
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• 2021

KRC (Korea Rural Community Corporation) is in charge of about 3,400 agricultural reservoirs out of 17,240 agricultural reservoirs, and automatic water level gauges in reservoirs and canals were installed to collect reservoir and canal water level data from 2010. In this study, 10-minute water level data of 173 reservoir irrigation canals from 2016 to 2018 are collected, and discharge during irrigation season was calculated using rating curves. For estimation of water supply, irrigation water requirement was calculated with HOMWRS (Hydrological Operation Model for Water Resources System), and the summation of reservoir water storage decrease was calculated with daily reservoir storage data from RAWRIS (Rural Agricultural Water Resource Information System). From the results, the total yearly amount of irrigation water supply showed less than 10% difference than the irrigation water requirement. The regional analysis revealed that reservoirs in Jeollanam-do and Chungcheongnam-do supply greater irrigation water than average. On the contrary, reservoirs in Gyeongsangnam-do and Chungcheongbuk-do supply less than others. This study was conducted with a limited number of reservoirs compared to total agricultural reservoirs. Nevertheless, it can indicate irrigation water supply from agricultural reservoirs to provide information about agricultural water use for irrigation.

• Journal of The Korean Society of Agricultural Engineers
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• v.65 no.1
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• pp.15-26
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• 2023

This study aimed to evaluate the performance of water level classification from CCTV images in agricultural facilities such as reservoirs. Recently, the CCTV system, widely used for facility monitor or disaster detection, can automatically detect and identify people and objects from the images by developing new technologies such as a deep learning system. Accordingly, we applied the ResNet-50 deep learning system based on Convolutional Neural Network and analyzed the water level of the agricultural reservoir from CCTV images obtained from TOMS (Total Operation Management System) of the Korea Rural Community Corporation. As a result, the accuracy of water level detection was improved by excluding night and rainfall CCTV images and applying measures. For example, the error rate significantly decreased from 24.39 % to 1.43 % in the Bakseok reservoir. We believe that the utilization of CCTVs should be further improved when calculating the amount of water supply and establishing a supply plan according to the integrated water management policy.

• Journal of Bio-Environment Control
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• v.22 no.2
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• pp.162-166
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• 2013

The objective of this study was to investigate the influence of fertilization levels by soil testing on plant growth and fruit quality of musk melon in greenhouse cultivation. Leaf area and fruit weight were severely affected by fertilization level. Leaf areas were significantly reduced by 54.1% and 24.5% at 0 and 50% fertilization level compared to the 100% fertilization level, respectively. Fruit weights were reduced by 38.2% and 19.9% at 0 and 50% fertilization level compared to the 100% fertilization level, respectively. However, soluble solids and sucrose contents were increased by 1.8% and 23.3% at 50% fertilization level compared to the 100% fertilization level, respectively. These results suggest that reduction of 50% fertilization level by soil testing seem to be effective methods to reduce salt accumulation in the soil as well as increasing of fruit quality such as soluble solids and sucrose contents.

• Journal of Preventive Medicine and Public Health
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• v.39 no.6
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• pp.493-498
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• 2006

Objectives : Diabetes has been reported as a risk factor for several cancers. However, the association between diabetes and gastric cancer has been inconsistent. The aim of this study was to evaluate the association between the fasting serum glucose level and gastric cancer risk in Korea. Methods : Among the members of the Korean Multi-Center Cancer Cohort (KMCC) from 1993 to 2004, a total of 100 incident gastric cancer cases were ascertained until December 31, 2002 and 400 controls were matched according to age, sex, and year and area of enrollment. Of the eligible subjects, those without fasting serum glucose level information were excluded, with a total of 64 cases and 236 controls finally selected. On enrollment, all subjects completed a baseline demographic and lifestyle characteristics questionnaire, and had their fasting serum glucose level measured. The Helicobacter pylori infection status was determined by an immunoblot assay using long-term stored serum. The odds ratios (ORs) were estimated using conditional and unconditional logistic regression models adjusted for the H. pylori infection status, smoking, drinking, education, follow-up period and matching variables. Results : The ORs for risk of gastric cancer according to the serum glucose level were 1.33 [95% CI=0.50-3.53] and 1.66 [95% CI=0.55-5.02] for the categories of 100-125 and 126 mg/dL or greater, respectively, compared to the category of less than 100 mg/dL. No increased risk of gastric cancer according to the serum glucose level was found (p-trend=0.337). Conclusions : This study provides no evidence for an association of the serum glucose level with gastric cancer.