• Journal of Preventive Medicine and Public Health
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• v.29 no.3 s.54
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• pp.529-538
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• 1996

We investigated the occurrence of color vision loss in 70 organic solvent mixtures exposed workers and in 47 controls. Color Vision was assessed with a color arrangement test designed to identify the defective color sense, the Han Double 15-Hue Test. The results of the test were no significant difference between exposed workers and controls in the proportion of subjects who committed one or two errors. Quantitative analysis, using color confusion index(CCI), showed no signicant difference between exposed workers and controls. A significant linear correlation was present between age and CCI in both exposed workers (CCI=0.0056age + 0.94; r=0.23; p<0.05) and controls(CCI=0.0066age + 0.86; r=0.33; p<0.05). Qualitative analysis of the patterns on the hue circle showed that the prevalence of acquired dyschromatopsia was 21% in both and no significant difference. Multiple regression analyses showed that age was significantly related to color vision loss. These results did not provide evidence of a relationship between organic solvents exposure and incidence of color vision loss. In field studies for monitor the people at risk of the acquired color vision loss involving low-dose organic solvents exposed workers, both quantitative and qualitative information should be considered.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.10 no.4
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• pp.506-519
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• 1999

An adaptive array antennal and a CCI canceller have been considered as techniques for cancelling Multi-User Interference(MUI) in Direct Sequence Code Division Multiple Access(DS-CDMA) system. These techniques have different problems respectively in the process of cancelling MUI as the number of users increases. For that reason, the scheme which can cancel MUI effectively by compensating for the problems of each of the techniques has been required. For the scheme, the technique to connect an adaptive array antenna and a CoChannel Interference(CCI) canceller in cascade form has been studied. In the existing study about the cascade connection method, the effect of cancelling MUI about two interference signals is analyzed, but the analysis for the quantitative BER(Bit Error Rate) improvement according to the number of users is not considered. Therefore, in this paper, we have analyzed the degree of BER performance improvement quantitatively according to the number of users by introducing the receiving system, which connects an adaptive array antenna and a CCI canceller to a DS-CDMA system in cascade form. For the method of analyzing the performance, we have performed the theoretical analysis and the simulation, considering the case of adopting only an adaptive array antenna and of cascade connection respectively, and having compared and analyzed the results. From the results, it is confirmed that in the case of adopting only an adaptive array antenna, the problems occur in the process of cancelling MUI according to the number of users and the receiving direction of interference signals, and can be compensated by the cascade connection method. In conclusion, we have known that MUI is cancelled effectively by using the cascade connection method, and the much better BER performance improvement is obtained.

• Journal of Korean Dental Science
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• v.8 no.2
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• pp.82-88
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• 2015

Purpose: To evaluate the effect of light-curing on the immediate and delayed micro-shear bond strength (${\mu}SBS$) between yttria-tetragonal zirconia polycrystal (Y-TZP) ceramics and RelyX Ultimate when using Single Bond Universal (SBU). Materials and Methods: Y-TZP ceramic specimens were ground with #600-grit SiC paper. SBU was applied and RelyX Ultimate was mixed and placed on the Y-TZP surface. The specimens were divided into three groups depending on whether light curing was done after adhesive (SBU) and resin cement application: uncured after adhesive and uncured after resin cement application (UU); uncured after adhesive, but light cured after resin cement (UC); and light cured after adhesive and light cured resin cement (CC). The three groups were further divided depending on the timing of ${\mu}SBS$ testing: immediate at 24 hours (UUI, UCI, CCI) and delayed at 4 weeks (UUD, UCD, CCD). ${\mu}SBS$ was statistically analyzed using one-way ANOVA and Student-Newman-Keuls multiple comparison test (P<0.05). The surface of the fractured Y-TZP specimens was analyzed under a scanning electron microscope (SEM). Result: At 24 hours, ${\mu}SBS$ of UUI group ($8.60{\pm}2.06MPa$) was significantly lower than UCI group ($25.71{\pm}4.48MPa$) and CCI group ($29.54{\pm}3.62MPa$) (P<0.05). There was not any significant difference between UCI and CCI group (P>0.05). At 4 weeks, ${\mu}SBS$ of UUD group ($24.43{\pm}2.88MPa$) had significantly increased over time compared to UUI group (P<0.05). The SEM results showed mixed failure in UCI and CCI group, while UUI group showed adhesive failure. Conclusion: Light-curing of universal adhesive before or after application of RelyX Ultimate resin cement significantly improved the immediate ${\mu}SBS$ of resin cement to air-abrasion treated Y-TZP surface. After 4 weeks, the delayed ${\mu}SBS$ of the non-light curing group significantly improved to the level of light-cured groups.

• Journal of Microbiology and Biotechnology
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• v.26 no.6
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• pp.1140-1147
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• 2016

The plasma and serum of Crocodylus siamensis have previously been reported to exhibit potent antimicrobial, antioxidant, and anti-inflammatory activities. During wound healing, these biological properties play a crucial role for supporting the formation of new tissue around the injured skin in the recovery process. Thus, this study aimed to evaluate the wound healing properties of C. siamensis plasma and serum. The collected data demonstrate that crocodile plasma and serum were able to activate in vitro proliferation and migration of HaCaT, a human keratinocyte cell line, which represents an essential phase in the wound healing process. With respect to investigating cell migration, a scratch wound experiment was performed which revealed the ability of plasma and serum to decrease the gap of wounds in a dose-dependent manner. Consistent with the in vitro results, remarkably enhanced wound repair was also observed in a mouse excisional skin wound model after treatment with plasma or serum. The effects of C. siamensis plasma and serum on wound healing were further elucidated by treating wound infections by Staphylococcus aureus ATCC 25923 on mice skin coupled with a histological method. The results indicate that crocodile plasma and serum promote the prevention of wound infection and boost the re-epithelialization necessary for the formation of new skin. Therefore, this work represents the first study to demonstrate the efficiency of C. siamensis plasma and serum with respect to their wound healing properties and strongly supports the utilization of C. siamensis plasma and serum as therapeutic products for injured skin treatment.

• Korean Journal of Remote Sensing
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• v.37 no.5_1
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• pp.1199-1206
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• 2021

Accordingly, attention is also being paid to the agricultural use of remote sensing technique that non-destructively and continuously detects the growth and physiological status of crops. However, when remote sensing techniques are used for crop monitoring, it is possible to continuously monitor the abnormality of crops in real time. For this, standard growth information of crops is required and relative growth considering the cultivation environment must be identified. With the relationship between GDD (Growing Degree Days), which is the cumulative temperature related to crop growth obtained from ideal cultivation management, and the vegetation index as standard growth information, compared with the vegetation index observed with the spectralreflectance sensor(SRS_NDVI & SRS_PRI) in each rice paddy treated with standard cultivation management and non-fertilized, it was quantitatively identified as a time series. In the future, it is necessary to accumulate a database targeting various climatic conditions and varieties in the standard cultivation management area to establish a more reliable standard growth information.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.11
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• pp.126-136
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• 2018

The purpose of this study was to develop a severity-adjustment model for predicting mortality in acute stroke patients using machine learning. Using the Korean National Hospital Discharge In-depth Injury Survey from 2006 to 2015, the study population with disease code I60-I63 (KCD 7) were extracted for further analysis. Three tools were used for the severity-adjustment of comorbidity: the Charlson Comorbidity Index (CCI), the Elixhauser comorbidity index (ECI), and the Clinical Classification Software (CCS). The severity-adjustment models for mortality prediction in patients with acute stroke were developed using logistic regression, decision tree, neural network, and support vector machine methods. The most common comorbid disease in stroke patients were hypertension, uncomplicated (43.8%) in the ECI, and essential hypertension (43.9%) in the CCS. Among the CCI, ECI, and CCS, CCS had the highest AUC value. CCS was confirmed as the best severity correction tool. In addition, the AUC values for variables of CCS including main diagnosis, gender, age, hospitalization route, and existence of surgery were 0.808 for the logistic regression analysis, 0.785 for the decision tree, 0.809 for the neural network and 0.830 for the support vector machine. Therefore, the best predictive power was achieved by the support vector machine technique. The results of this study can be used in the establishment of health policy in the future.

• The Journal of the Korea Contents Association
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• v.21 no.4
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• pp.487-497
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• 2021

The purpose of this study is to identify factors affecting length of stay(LOS) and death in tuberculosis(TB) patients by disease type, patient characteristic, admission and disease characteristic, and hospital characteristic from 2008 to 2017. Survey data was using Korean national hospital discharge in-depth survey data produced by Korea Disease Control and Prevention Agency. Study subjects were 10,634 inpatients with TB(A15, A16, A17, A18, A19, U88.0, U88.1, U84.30, U84.31) and analyzed frequency, chi-square test, Fisher's exact test, and logistic regression by using STATA 13.0. As a study result, the type of TB(extrapulmonary TB, multidrug-resistant TB, extensively drug-resistant TB), sex(woman), age(35-49, 50-64, 65-74, 75 years old or older), admission type(outpatient department), CCI(1-2 point, 3 point over), hospital location(metropolitan city) and bed size(300-499, 500-999, over 1000) were significantly influence LOS. Also, the type of TB(extrapulmonary TB, extensively drug-resistant TB), sex(woman), age(50-64, 65-74, 75 years old or older), residence(small town/rural), admission type(outpatient department), CCI(1-2 point, 3 point over), hospital location(provincial) were significantly influence death. In conclusion, the existing tuberculosis management has been patient management with rapid diagnosis and treatment following early detection. But other studies should be carried out for the system that identifies and supports high-risk groups of the long-term length of stay in hospital or high mortality rates as a result of treatment.

• Research in Community and Public Health Nursing
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• v.31 no.2
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• pp.143-155
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• 2020

Purpose: This study aimed to explore the difficulties and coping that advanced practice nurses (APNs) experience in home health nursing field. Methods: The participants were 12 APNs who had experience in home health nursing for over 5 years. Data were collected through two focus group interviews between August and September, 2017. The results were analyzed using a qualitative content analysis. Results: Out of 10 sub-categories and 29 codes, 4 categories emerged: "crushed by the responsibilities as the only healthcare professional", "worn out by family who interfere with work", "anxiety about my safety being threatened" and "using self-learned know-hows". Conclusion: APNs face difficulties due to the environmental characteristics of the homes, the characteristics of chronically critically ill (CCI) patients and their families, and legal or systematical limitations when dealing with problems based on their personal competence. In order to ensure that professional nursing care is more readily provided to CCI patients through home health nursing services in local communities, it is imperative that support systems at the organizational and institutional levels be established in a systematic way to resolve the issues faced by APNs.

• YAKHAK HOEJI
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• v.37 no.3
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• pp.270-277
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• 1993

It is well known that lipidperoxide, formed in vivo, induced the denaturation of enzyme and destruction of cell membrane to acute injury of tissue. Aralia elata have physiological activates, the improvement of lipid metabolism, antidiabetic activity etc., which was thought to have the relationship to lipid peroxidation. The anti-lipidperoxidative effect of Aralia elata have not yet established. In this study, we examined the anti-lipidperoxidative effects of Aralia elata (Butanol fraction) on CCI$_{4}$ induced lipidperoxidation in rats, and elucidated the anti-lipidperoxidative mechanism. In rat liver homogenate intoxicated with CCI$_{4}$ (0.5 ml/100g), BuOH fraction of Aralia elata (80 mg/Kg/day) exhibited 85.41% anti-lipidperoxidative effect but in serum 69.63% inhibitory effects, respectively. In mitochondrial and microsomal fraction showed inhibition of 55.85% and 69.30%, respectively. In order to elucidate the mechanism of anti-lipidperoxidation effects of Aralia elata, enzymatic (NADPH dependent) and non-enzymatic (Ascorbic acid catalyzed) reaction, in vitro, were performed. In enzymatic reation, Aralia elata exhibited 59.43% anti-lipidperoxidation effects, but in non-enzymatic reaction exhibited 43.27% inhibition. Therefore, it is noteworthy that antioxidative power of them may mainly results from the inhibition by enzymatic reaction.

• Computers and Concrete
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• v.14 no.1
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• pp.91-107
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• 2014

Using the principle of damage mechanics, zero-thickness pore pressure cohesive elements (PPCE) are used to simulate the casing-cement interface (CCI) and cement-rock interface (CRI). The traction-separation law describes the emergence and propagation of the PPCE. Mohr-coulomb criteria determines the elastic and plastic condition of cement sheath and rock. The finite element model (FEM) of delamination fractures emergence and propagation along the casing-cement-rock (CCR) interfaces during hydraulic fracturing is established, and the emergence and propagation of fractures along the wellbore axial and circumferential direction are simulated. Regadless of the perforation angle (the angle between the perforation and the max. horizontal principle stress), mirco-annulus will be produced alonge the wellbore circumferential direction when the cementation strength of the CCI and the CRI is less than the rock tensile strength; the delamination fractures are hard to propagate along the horizontal wellbore axial direction; emergence and propagation of delamination fractures are most likely produced on the shallow formation when the in-situ stresses are lower; the failure mode of cement sheath in the deep well is mainly interfaces seperation and body damange caused by cement expansion and contraction, or pressure testing and well shut-in operations.