• Journal of Pharmacopuncture
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• v.18 no.3
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• pp.49-56
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• 2015

Objectives: Anaphylactic shock can be fatal to people who become hypersensitive when bee venom pharmacopuncture (BVP) is used. Thus, sweet bee venom (SBV) was developed to reduce these allergic responses. SBV is almost pure melittin, and SBV has been reported to have fewer allergic responses than BVP. BVP has been administered only into acupoints or intramuscularly, but we thought that intravenous injection might be possible if SBV were shown to be a safe medium. The aim of this study is to evaluate the intravenous injection toxicity of SBV through a single-dose test in Sprague-Dawley (SD) rats. Methods: Male and female 6-week-old SD rats were injected intravenously with SBV (high dosage: 1.0 mL/animal; medium dosage: 0.5 mL/animal; low dosage: 0.1 mL/animal). Normal saline was injected into the control group in a similar method. We conducted clinical observations, body weight measurements, and hematology, biochemistry, and histological observations. Results: No death was observed in any of the experimental groups. Hyperemia was observed in the high and the medium dosage groups on the injection day, but from next day, no general symptoms were observed in any of the experimental groups. No significant changes due to intravenous SBV injection were observed in the weights, in the hematology, biochemistry, and histological observations, and in the local tolerance tests. Conclusion: The results of this study confirm that the lethal dose of SBV is over 1.0 mL/animal in SD rats and that the intravenous injection of SBV is safe in SD rats.

• Journal of Korean Dental Science
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• v.4 no.2
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• pp.52-58
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• 2011

Purpose: Modifications of implant design have been related to improving initial stability. The purpose of this study was to investigate their respective effect on initial stability between two tapered implant systems (self-tapping vs. non-self-tapping) in medium density bone using three different analytic methods. Materials and Methods: Self-tapping implant (GS III$^{(R)}$; Osstem Implant Co., Busan, Korea) and non-self-tapping implant (Replace Select$^{(R)}$; Nobel Biocare, G$\H{o}$teborg, Sweden) were investigated. In Solid rigid polyurethane blocks of artificially simulated Quality 2 bone, each of the 5 implants was inserted according to the manufacturer's instructions for medium-bone drilling protocol. Evaluation of initial stability was carried out by recording the maximum insertion torque (IT) and performing the resonance frequency analysis (RFA), and the pull-out test. Results: The IT and RFA values of self-tapping implant were significantly higher than those of non self-tapping implant (P=.009 and P=.047, respectively). In the pull-out values, no significant differences were found in implants between two groups (P=.117). Within each implant system, no statistically significant correlation was found among three different outcome variables. Conclusions: These findings suggest that design characteristics of implant geometry significantly influence the initial stability in medium bone density.

• Journal of Electrical Engineering and Technology
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• v.13 no.4
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• pp.1663-1672
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• 2018

In recent times, gas insulated medium voltage (MV) circuit breakers (CB) form a vital component in power system network, considering its advantages such as reduced size and safety margins. Gas insulation characteristics of circuit breakers are generally measured by lightning impulse (LI) test according to IEC standard 60060-1 as a factory routine test. Considering the environmental issues of $SF_6$ gas, many research works are being carried out towards the mixture of $SF_6$ gases for high voltage insulation applications. However, few reports are only available regarding the LI withstand and streamer propagation characteristics (at both positive and negative polarity of waveform) of $SF_6/N_2$ gas mixture insulated medium voltage circuit breakers. In this paper, positive and negative polarity LI tests are carried out on 22 kV medium voltage circuit breaker filled with $SF_6/N_2$ gas mixture at different gas pressures (1-5 bar) and at different gas mixture ratios. Important LI parameters such as breakdown voltage, streamer velocity, time to breakdown and acceleration voltage are evaluated with IEC standard LI ($1.2/50{\mu}s$) waveform. Weibull distribution analysis of LI breakdown voltage data is carried out and 50% probability breakdown voltage, scale parameter and shape parameter are evaluated. Results illustrate that the $25%SF_6+75%N_2$ gas filled insulation considerably enhances the LI withstand and breakdown strength of MV circuit breakers. LI breakdown voltage of circuit breaker under negative polarity shows higher value when compared with positive polarity. Results show that maintaining the gas pressure at 0.3 MPa (3 bar) with 10% $SF_6$ gas mixed with 90% $N_2$ will give optimum lighting impulse withstand performance of 22 kV MV circuit breaker.

• Journal of Korean Clinical Nursing Research
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• v.24 no.3
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• pp.336-346
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• 2018

Purpose: This study was conducted to identify nurses'critical thinking disposition, self-leadership and clinical competency in small to medium sized hospitals less than 300beds. Methods: Data were collected using the questionnaire from 227 nurses in Incheon city and Gyeonggi province from March to April, 2017. The data were analyzed using t-test, ANOVA and $Scheff{\acute{e}}^{\prime}s$ test to identify differences in critical thinking disposition, self-leadership and clinical competency. Pearson correlation coefficients were used to identify the correlation among the study variables, and multiple regression was used to identify factors contributing to clinical competency. Results: There were significant differences in critical thinking disposition according to age, marital status, clinical career, career in currently working department and education about leadership. Significant differences in self-leadership were identified according to marital status, work position, working department, work type, education about leadership, and turnover intention. Clinical competency was significantly different depending on age, education, monthly income, work position, career in currently working department, work type, education about critical thinking disposition and education about leadership. Clinical competency was positively correlated critical thinking disposition and self-leadership. Critical thinking deposition, monthly income and self-leadership explained 30.1% of clinical competency of nurses working in small to medium sized hospitals. Conclusion: The results of this study suggest that we need to improve nurses'critical thinking disposition, self-leadership, and the clinical competency.

• Journal of Convergence for Information Technology
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• v.9 no.8
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• pp.83-92
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• 2019

This descriptive convergence research aimed to explore predictors of retention intention of nurses. Participants were 207 nurses from five small and medium-sized hospital located in city G and province J. Data were analyzed with descriptive statistics, independent t-test, one-way ANOVA, pearson's corelation coefficient and stepwise multiple regression. Among predictors, nursing practice environment, age, peer group caring interaction, current hospital work experience, and assignment to desired department significantly affected retention intention and nursing practice environment had the greatest effect on retention intention(${\beta}=.35$). Based on the results of this study, it is necessary to make efforts to improve nursing practice environment, caring interaction and good relationship between organizations.

• International Journal of Clinical Preventive Dentistry
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• v.14 no.4
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• pp.228-234
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• 2018

Objective: The authors have experimented for the artificial plaque removal effect of several kinds of 360 degree rotating head typed tooth-brushes with sonic vibratory actioned by using of automatic machine for horizontal scrub method in order to find the better toothbrush type for plaque removal. Methods: The experiment was conducted on three medium to 360 degree rotating head toothbrushes, a medium sized toothbrush and a medium sized toothbrush, and a flat toothbrush consisting of 30 ordinary toothbrushes. A brushing machine with horizontal scrubbing was manufactured and had variations of the end of the bristle attached to or near the surface of the teeth, a vibrating wave action force of 16,000 or 18,000 cycles per minute, and a working time of 2 or 3 minutes. The tooth removal effect was confirmed by scanning and analyzing images with a computer program after automatic brushing with the machine. The elimination rate results for each group were analyzed using the independent t-test and one-way ANOVA test. Results: It revealed the most in removal effect for the artificial plaque in such conditions as action at near the tooth surface with 18,000 cycle for 3 minutes in case of using A, B, and C tooth-brush. And it has more removal effect rate than for using the plane tooth-brush (p<0.05). Conclusion: It was recommended to develop the 360 degree rotating head and vibratory toothbrush focusing to use near the tooth surface with 18,000 cycles of vibration for 3 minutes at one site of the teeth area.

• Journal of Digital Convergence
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• v.19 no.4
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• pp.159-166
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• 2021

This study was an attempt to develop a multidrug resistant organisms infection control simulation program for nurses at small and medium sized hospitals and to evaluate the effectiveness of said simulation program. This is a single-group, pre-post experimental design study conducted on 33 nurses working at small and medium sized hospitals. Data obtained were analyzed using the IBM SPSS 21.0 program, along with the use of descriptive statistics and paired t-test. Regarding the results of the study, multdrug resistant organisms infecion control knowledge(t=-10.764, p<.001)and performance levels(t=-4.215, p<.001) of the nurses displayed statistically significant increases following application of the simulation program. There is a need for the development of more diversified simulation programs in the future since the improvement in the infection control knowledge and performance levels of nurses is important to block the spread of multidrug resistant organisms and prevent infection outbreak thereof with medical institutions.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.16 no.5
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• pp.79-92
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• 2006

Computer virus is one of the most common information security problems in the information age. This study investigates the difference of users' perception of security elements between large companies and small-and-medium companies on the subject of computer virus. Based on t-test, no significant difference is found in users' perception on security threat and security risk While users satisfy with the level of security policy, there is a significant difference on the level of security policy recognition between the two sizes of companies. Moreover, there are significant differences on information assets, security vulnerability and security effectiveness, which implies difference in the users' perception on importance of assets, exposure to threats and computer virus prevention efforts between large and small-and-medium companies.

• Journal of the Korean Geotechnical Society
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• v.37 no.12
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• pp.33-45
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• 2021

In this study, predictive equations of the normalized shear modulus and the damping ratio curves for loose medium sands reinforced by vinyl strip-cement are proposed. Based on the results of a series of resonant-column tests (Yu, et al., 2018) conducted under the confining stresses of 15, 30, 60 kPa on sand specimens prepared with 40% relative density and reinforced by various contents of vinyl strip (0.0, 0.1, 0.3, 0.4%) and cement (0, 1, 2%), the equations estimating the normalized shear modulus and the damping ratio are proposed as functions of reinforcing conditions and confining stresses. The comparison between predicted and measured values of shear modulus and damping ratio shows a good agreement and the reliability of proposed predictive equations are validated by high R2-value greater than 0.9. Therefore, it is expected that the time and the cost required for constructing the normalized shear modulus and the damping ratio curves will be much reduced by using proposed equations in this study since those can easily be estimated without conducting resonant-column test.

• Journal of the Korean Geotechnical Society
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• v.23 no.8
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• pp.69-76
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• 2007

Axial behavior of tapered piles is affected by taper angle, stress state of soils, soil frictional angle and pile-soil interface friction angle. In this paper, a series of model pile load tests were performed using a calibration chamber in order to investigate the effect of taper angle on the axial response of cast-in-place tapered piles in sand. According to results of the tests, as taper angle of piles increased, the shaft load capacity of piles increased but its base load capacity decreased. The unit base load capacity of piles increased with increasing taper angle for medium sand but decreased for dense sand. The ratio of shaft to total load capacity increased with increasing taper angle and with decreasing relative density of soils. The test results also showed that total load capacity per unit pile volume increased with increasing taper angle for medium sand, but it decreased for dense sand. Therefore, it can be stated that tapered piles are economically more beneficial for medium sand than for dense sand.