• The Korea Journal of Herbology
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• v.29 no.6
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• pp.63-71
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• 2014

Objectives : Lonicerae japonicae Flos(LJF) has been reported to exhibit anti-oxidant, anti-inflammatory, anti-viral, anti-rheumatoid properties. However, it is still largely unknown whether LJF inhibits the ultraviolet(UV)B-induced oxidative damage in human HaCaT keratinocytes. Therefore in this paper, we investigated the anti-oxidative capacity and protective effect of LJF against UVB-induced oxidative demage in human HaCaT keratinocytes. Methods : To evaluate the anti-oxidative activity of LJF extracts, we measured total phenolic contents, total flavonoid contents, antioxidant capacity, and superoxide scavenging activity. To give an oxidative stress to HaCaT cells, UVB was irradiated with $200mJ/cm^2$ to HaCaT cells. To detect the protective effect of LJF against UVB, we measured cell viability, DNA fragmentation and reactive oxygen species (ROS) production. In addition, we performed high-performance liquid chromatography (HPLC) analysis to find a major component of LJF. Results : LJF contained phenolic and flavonoid contents, and showed the anti-oxidant and superoxide scavenging activity. The UVB-induced oxidative conditions led to the cell death, DNA fragmentation and reactive oxygen species (ROS) production. However, pretreatment with LJF reduced oxidative conditions, including inhibition of cell death, DNA fragmentation and ROS production. In addition, we found out chlorogenic acid as major component of LJF. Conclusions : These results could suggest that LJF contained anti-oxidative contents and exhibited protective effects against UVB on human HaCaT keratinocytes. And the effective compound of LJF which could show protective activities against UVB is chlorogenic acid. Thus, LJF and chlorogenic acid would be useful for the development of drug or cosmetics treating skin troubles.

• Korean Journal of Food Science and Technology
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• v.48 no.2
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• pp.172-177
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• 2016

The phenolic compounds, antioxidant activity and neuronal cell protective effect of Cirsium japonicum extract were evaluated in this study. High performance liquid chromatography mass analysis showed that C. japonicum was composed of chlorogenic acid, linarin, and pectolinarin. C. japonicum extract showed its antioxidant activity with half-maximal inhibitory concentrations of 567 and $130{\mu}g/mL$ by DPPH and ABTS radical scavenging activity, respectively. The total antioxidant capacities of C. japonicum via DPPH, ABTS, and FRAP assays were 11.32, 100.15, and $12.76{\mu}g/mL$ trolox equivalents, respectively. In addition, the neuroprotective effect of C. japonicum extract was investigated by measuring cell viability via MTT, LDH and DCF-DA assay using $H_2O_2-damaged$ PC12 cells. C. japonicum extract showed neuronal cell protective effects in a dose-dependent manner. These results indicated that C. japonicum extract has potent antioxidant and neuronal protective effects. Therefore, C. japonicum can be regarded as an effective and safe functional food resource as natural antioxidants, and may decrease the risk of neurodegenerative disorders.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.4
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• pp.93-102
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• 2018

This paper reports a Surge Protective Device (SPD) that is used to protect an automatic metering interface (AMI) power supplies of communication equipment on a low-voltage distribution system from a lightning current. The surge protective device (SPD) can be classified as one-port SPDs and two-port SPDs with decoupling elements depending on the connection type. The protection of internal systems against the lightning current may require a systematic approach consisting of coordinated SPDs. To deal with this, the definition of a lightning protection zone (LPZ) was studied and interpreted through a theoretical review. Because the lightning current resulting from a lightning surge is considerably high, there is limited protection from one SPD; therefore, coordinated cascaded MOV-based SPDs are installed to solve this problem. Regarding the power grid mentioned in this paper, a class II SPD for the low-voltage distribution system installed on the border of LPZ1 and LPZ2, which establish a protection coordination with the Arrester (LA, SA) that corresponds to the LPZO installed on the MOF stage connected to one system were designed to protect various communication (control) equipment, including the automatic meter reading system inside the branch-type electric supply panel of a building, not the incoming side of one system. In addition, performance-related tests were done by a comparison with the existing method through testing, and the optimal design was achieved for the 1-port SPD that uses a series connection and can bleed load current without any decoupling element.

• Korean Journal of Childcare and Education
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• v.8 no.1
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• pp.25-44
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• 2012

The purpose of this study was to conduct a systematic review of the previous studies done on the child-care teacher's turnover intentions. From 2001 to 2011, 33 articles which reforted primary empirical data met the criteria for inclusion in the meta-analysis. The results of this study are as follo ws: First, included in the main factors related to child-care teachers' turnover intentions were a job-related variable, an organizational internal variable and an organizational external variable. Second, the most influential protective variable related to the child-care teacher's turnover intentions among the set of organizational external variables was work-time followed by welfare, education and training, remuneration, social recognition and promotion system. Third, the most influential protective variable related to child-care teachers' turnover intentions among the set of job-related variables was teacher efficacy followed by job satisfaction, participation of decision making, performance, work-autonomy and work-professionalism. Fourth, the most influential protective variable related to the child-care teacher's turnover intentions among the set of organizational internal variables was personal relations followed by relationships with the director and relationships with colleagues. The effect size of these variables was large. Fifth, the results of meta-regression analysis revealed that the survey area and years had no significant effect on overall effect sizes.

• Journal of the Korean Society of Clothing and Textiles
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• v.20 no.2
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• pp.350-361
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• 1996

The objectives of this study mere 1) to investigate whether the different nonwoven fabric types influenced on the objective and subjective wear performances of the experimental pesticide protective pants, 2) to detect whether the different finishes treated to the nonwoven fabrics influenced on the objective and subjective wear performances of the experimental pants, and 3) to detect the relationships between objective wear performances and subjective wear sensation. Three types of nonwoven fabrics (T (Tyvek$\textregistered$), 5 (Sontara$\textregistered$) and K (Kimlon$\textregistered$)) were used as test specimens. By pad-dry.cure method, each of the specimen was treated with fluorocarbon compound for water-oil repellent finish (Tw, Sw, Kw). And each of specimen was treated with organic silicon quarternary ammonium salts and then treated with fluorocabon compound for dual functional finish (76, 50, Kd). Using the three water-oil repellent finished fabrics and the three dual functional finished fabrics, six experimental protective pants (Cl (Tw), C2 (Sw), C3 (Kw), C4 (76), C5 (56), C6 (Kd)) were made according to the same pattern suggested by the Rual Guidance Office. The wear trials of experimental pesticide protective pants were performed in a conditioned vinyl plastic hothouse ($30\pm1^{\circ}C$, $70\pm5%$R.H., 0.25m/sec air velocity). The measurements of skin temperature, microclimate temperature and humidity on the subjects were obtained by the themohygromenter. The subjective wear sensations were measured using previously developed thermal, humidity and overall comfort scales. The results obtained from this study were as follows: 1) There were siginificant differences among nonwoven fabric types on the objective and subjective wear performances, therefore, the skin temperature, microclimate temperature and humidity of subjects who wore the experimental pants made with Sontara were siginificantly lower than those who wore the others. And, the experimental pants made with Sontara were assessed as more comfortable than the others in terms of the subjective thermal, humidity and overall wear sensations. 2) There were no significant differences between two finish types on the objective and subjective wear Performances. 3) The microclimate humidity on the thigh was highly correlated with the overall subjective comfort sensations and the next highly correlated one was the mean skin temperature. That is, the higher the microclimate humidity and the mean skin temperature, the higher the overall subjective comfort sensation ratings which mean the overall subjective sensation was very uncomfortable.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.6
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• pp.573-582
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• 2021

In this study, a series of processes for evaluating the effective protection against barriers that should be equipped in institutions that perform reliability tests on high-risk ammunition, such as high-explosive ammunition, were introduced. The impact that high-explosive bombs can have on personnel includes damage to the eardrum and lungs caused by explosion overpressure and penetrating wounds that can be received by fragments generated simultaneously with the explosion. Therefore, a high-explosive with COMP B explosives as its contents were set up, and an explosion protection theory investigation to calculate the degree of damage, numerical calculations and simulations were performed to verify the protection power. A numerical calculation revealed the maximum explosion overpressure on the protective wall when the high-explosive exploded and the penetration force of the fragment against a 50 mm-thick protective wall to be 77.74 kPa and 41.34 mm, respectively. In the simulation verification using AUTODYN, the maximum explosion overpressures affecting the firewall and personnel were 56.68 kPa and 18.175 kPa, respectively, and the penetration of fragments was 35.56 mm. This figure is lower than the human damage limit, and it was judged that the protective power of the barrier would be effective.

• The Journal of the Korea Contents Association
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• v.21 no.2
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• pp.227-235
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• 2021

The purpose of this study was to investigate the association factors of dental infection control by applying the health belief model in the dental hygienists. This study subject was 142 dental hygienists from 15 to July 5, 2020. Data were analyzed by chi-square test ANOVA, correlation analysis, and multiple regression analysis using SPSS version 23.0. The performance of dental infection control in accordance with the general characteristics of research subjects was high in case when they had educational experiences of infection control, and when they 'always' did medical examinations by interview about infectious diseases(p<0.01). The group of dental hygienists working for dental clinics with less than average 50 patients a day showed the highest rate of wearing a mask and latex gloves as personal protective gears(p<0.05),(p<0.01). When the wearing of protective goggles(face shield) and the frequency of exchanging masks after the outbreak of COVID-19 were more, the performance for infection control was increasing(p<0.05),(p<0.01),(p<0.001). In this study, it is difficult to generalize the results of the study because the research area and the subject are limited by selecting the subjects by convenience extraction, and focusing on the degree of awareness of infection control by dental hygienists, the actual status of infection control in dentistry is carefully illuminated. What you didn't do can be seen as a limitation. Considering the results of this study, the performance of infection control could be increased by removing obstacles and increasing the importance and perceived benefits of infection control of dental hygienists.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.23 no.10
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• pp.75-80
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• 2009

In order to prevent loss of communication packets and drop of transmission speed owing to the network fault occurrence, it should be considered network redundancy. That is why a messages of IED GOOSE is the critical signal in charge of protection and control of the substation. So most of users implement the substation automation system with Hybrid network topology ant IED supporting double ethernet ports. Because IEC 61850 GOOSE conformance test is limited in the functional test, this paper suggests how to test the performance of IED GOOSE transmission considering Network redundancy, and describes the analysis of an example test on real IEDs and how to impact the IED GOOSE performance to the substation automation system.

• Proceedings of the KIEE Conference
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• 2005.07a
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• pp.510-512
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• 2005

This paper introduces the development of automatic system for estimation of digital relay performance. We have developed an automatic estimation system "HRV2004(Himap Relay function Verifier 2004)" for digital relay in 2004 and it has been verified in the field for one years. This paper describes the development details and field experience of HRV2004. HRV2004 can perform a series of jobs required for the relay testing in one environment and could handle most of all models of protective relay currently produced by Hyundai Heavy Industries. The functionality of this program consists of GUI of relay setting for beginner, fault record analysis and relay performance estimation. The core of this system is an automatic reporting of estimation test. If user is only click a button for relay estimation and one will received testing report to deliver customer. Additional benefit is fast response than the manual estimation. For example, the manual estimation takes spending 6 hours but this system is about 15 minutes.

• Korean Journal of Occupational Health Nursing
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• v.15 no.1
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• pp.40-49
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• 2006

Purpose: This study was designed to investigate nursing students' exposure experience to infectious diseases and their knowledge and performance for the nosocomial infection control. Method: The data was obtained from 292 nursing students having clinical experience at two university hospitals in Seoul from November 2005 to February 2006. Specific questionnaire was constructed and used for this study. The obtained data was analyzed by using the SPSS window program. Result: The results were as follow : 1. Among the evaluation scores of knowledge for the nosocomial infection control, the score of sterilization and the score of the intravenous therapy management were low(.14). 2. Among the evaluation scores of performance for the nosocomial infection control, the score of hand washing is low(1.63). 3. 86.3 percent of the nursing students had exposure experience to infectious disease. Many of them did not use the protective equipments in clinical experience nor took any treatment after the exposure to infectious diseases. Conclusion: Based on these results, we suggest that the programs for the nosocomial infection control should be developed for nursing students. It is also suggested that nursing students should be educated before their clinical experience to keep protected from the infection. In particular, the hand washing, sterilization and intravenous therapy management should be emphasized in the educational programs.