• Journal of the Computational Structural Engineering Institute of Korea
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• v.33 no.4
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• pp.255-261
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• 2020

This study proposes a method of constructing an effective shock absorber. The existing shock absorber is fabricated only with polyethylene; however, the new shock absorber comprises polyethylene on the outside and a high-density material on the inside. The shock was mostly reduced when the density difference between the inner and outer materials was large. Aluminum, titanium, and copper were chosen as the outer structure of two-layer. Shock reduction was most effective in copper with the highest density, and the maximum deceleration was reduced by 43% while the impulse was reduced by 51% in the proposed shock absorber than the traditional shock absorber. In the cases of four-layer and six-layer shock absorbers, the impulse was reduced, but the maximum deceleration was increased. The fuze must survive from the biggest shock and the remaining shock waves should not exceed the threshold. Thus, a two-layer structure shock absorber using polyethylene-copper was proposed.

• The Korean Journal of Emergency Medical Services
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• v.15 no.2
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• pp.43-54
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• 2011

Purpose: The purpose of this study was to explore EMT-paramedic students' experience of simulation education and analyze the confidence before and after education, learning attitude and course evaluation. Method: Research survey was conducted on 38 EMT-paramedic students during November, 2011 and EMT-paramedic students' experience of simulation education was analyzed after applying head, spinal, and chest injury scenario. The confidence before and after education, learning attitude and course evaluation in gender were analyzed by Mann-Whitny U test and the difference of confidence before and after education was analyzed by Wilcoxon signed rank test and learning attitude & course evaluation were analyzed by evaluating frequency, percentage, mean, standard deviation by using SPSS WIN 17.0 program. Results: 1. Students experienced various advantages such as increasing interest and self-reflection on learning, critical thinking ability, and EMT-paramedic-role experience and recognition of importance of teamwork. Students also pointed out disadvantages such as gap between real situation and simulation, limit of time and equipments, and burden of demonstration. 2. The confidence between before and after education, learning attitude and course evaluation in gender were not significant different statistically. 3. Confidence mean score elevated from 5.53(before education) to 5.87(after education), but the difference in their confidence did not show significant difference statistically. 4. Total mean score in learning attitude after simulation education was 3.70 out of 5.00, which is considerably very high. 5. Total mean score in course evaluation was 3.89 with score of 3.83 in evaluation in learning environment and 3.99 in evaluation of debriefing. Conclusion: The finding of this study demonstrate that the simulation education can provide a safe and repetitive practice environment, improve problem-solving ability and critical thinking, and increase the confidence in prehospital emergency care; therefore, simulation may be the new effective EMT-paramedic education strategy.

• The Journal of Advanced Prosthodontics
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• v.5 no.3
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• pp.296-304
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• 2013

PURPOSE. The aim of this study was to evaluate the effect of polishing and glazing on the color and spectral distribution of monolithic zirconia. MATERIALS AND METHODS. Forty-five monolithic zirconia specimens ($16.3mm{\times}16.4mm{\times}2.0mm$) were fabricated and divided into 5 groups according to the number of A2-coloring liquid applications (Group I to V). Each group was divided into 3 subgroups according to the method of surface treatments (n=3): N: no treatment; P: polishing; G: glazing. Color and spectral distribution of five different areas of each specimen were measured according to CIELAB color space in the reflectance mode relative to the standard illuminant D65 on a reflection spectrophotometer. Data were analyzed using one-way ANOVA followed by Tukey's HSD test, Pearson correlation and regression analysis (${\alpha}$=.05). RESULTS. There was a significant difference in CIE $L^*$ between Subgroup N and P, and in CIE $b^*$ between Subgroup P and G in each group. Spectral reflectance generally decreased in Subgroup P and G in comparison with Subgroup N. Color differences between Subgroup P and G were within the perceptibility threshold (${\Delta}E{^*}_{ab}$ < 3.7) in most groups. Highly significant correlation was found between CIE $b^*$ and each subgroups as the number of coloring liquid applications increased ($R^2$ >0.88, P<.001). CONCLUSION. A perceptible color difference can be detected after polishing of monolithic zirconia. Polishing decreases the lightness, and glazing also decreases the lightness, but increases the yellowness of monolithic zirconia.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.26 no.5
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• pp.445-454
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• 2015

In this paper, we propose an optimal design method for a dual reflector antenna(DRA) using the Genetic algorithm. In order to reduce the computational burden during the optimal design, we exploit the iterative physical optics(IPO) to calculate the surface current distribution at each reflector antenna. To improve the accuracy, we consider the shadow effect by the structure and the coupling effect by the multi-reflection based on the iterative MFIE(Magnetic Field Integral Equation). To reduce the number of design variables and generate a smooth surface, we use the Bezier function with the control points, which become the design variables in this paper. We adopt the HPBW(Half Power Beam Width), the FNBW(First Null Beam Width), and the SLL(Side Lobe Level) as the objective or cost functions. To verify the results, we compare them with the those of the commercial tool.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.25 no.4
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• pp.442-450
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• 2014

This paper is a study of the propagation characteristic of matching liquids in the skin-covered breast model. In order to evaluate the matching liquids, we investigated six kinds of matching liquids applied to proposed 1-D breast model from frequency range of 3~6 GHz. A uniform plane wave is projected / transmitted inside the multi-layered breast model. Then the propagation characteristics inside the model and the transmission loss of each matching liquids were analyzed. The studying method presented in the paper can be used in the breast cancer detection system, the field of cancer detection using human tissue and the field of other medical devices. This paper was applied to the breast cancer detection system. Consequently, these studies could be used to determine the suitable type of matching liquids for breast cancer detection system and to apply useful for performance analysis.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.18 no.6
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• pp.241-250
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• 2019

Road signs are guide facilities for road users, and the Ministry of Land, Infrastructure and Transport has established and operated a system to enhance the convenience of managing these road signs. The role of road signs will decrease in the future autonomous driving, but they will continue to be needed. For the accurate mechanical recognition of texts on road signs, automatic road sign recognition equipment has been developed and it has applied image-based text recognition technology. Yet there are many cases of misrecognition due to irregular specifications and external environmental factors such as manual manufacturing, illumination, light reflection, and rainfall. The purpose of this study is to derive location-based destination names for finding misrecognition errors that cannot be overcome by image analysis, and to improve the automatic recognition of road signs destination names by using Levenshtein similarity verification method based on phoneme separation.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.16 no.4
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• pp.133-140
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• 2006

The growth characteristics and properties of large size $SrAlF_5$ single crystals are described and compared with those of $BaMgF_4$. Transmission spectra in the vacuum ultraviolet wavelength region indicate a high transparency of $SrAlF_5$ (about 90% without considering surface reflection loses) down to 150 nm, on contrast to the optical loses observed for $BaMgF_4$. The ferroelectric character of $SrAlF_5$ is evidenced by the reversal of the spontaneous polarization in a hysteresis loop. The higher potential of $SrAlF_5$ in comparison with $BaMgF_4$ for the realization of all-solid-state lasers in the ultraviolet wavelength region by the quasi-phase matching (QPM) technique is pointed out. $SrAlF_5$, besides a higher grade of transparency, shows a nonlinear effective coefficient similar to that of quartz and uniaxial nature, on contrast to the one order smaller nonlinear coefficient and biaxial character of $BaMgF_4$. The refractive index of $SrAlF_5$ from the ultraviolet to the near-infrared wavelength region is measured by the minimum deviation method. The Sellmeier and Cauchy coefficients are obtained from the fits to the curves of the ordinary and extraordinary refractive indices, and the grating period for the first order QPM is estimated as a function of the wavelength. The poling periodicity for 193 nm SHG from 386 nm is $4{\mu}m$.

• Journal of Korean Academy of Fundamentals of Nursing
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• v.12 no.1
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• pp.91-100
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• 2005

Purpose: This research used quantitative research to identify differences in death consciousness between pre and post education. The study was also designed to further understanding of the effects of nursing education by using a qualitative analysis to examine hospice education experience. Method: This study a one group pre-post test design. Results: 1 The mean score for the students' death consciousness before the hospice education averaged $2.15{\pm}\;.33$, a medium level for death Consciousness. The Score after education was $2.25{\pm}\;.36$, that is, there was higher score for death consciousness after education. 2. The result of classification, giving their names and categorizing the experience of being in a coffin shown to be self-reflection, regret, recognition to death, death as discontinuation of life, the last closing from everything, death as a sad and cruel event, death as another world, specialist intuition of nursing. Conclusion: This research provided an opportunity for nursing students to consider death earnestly and realistically through hospice nursing education. We also discovered affirmative changes in the students' viewpoint of death, students who in future clinical practice may work with elders. We also found increases in motives to develop ability to present effective aid to dying patients.

• Korean Journal of Oriental Medicine
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• v.14 no.3
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• pp.97-102
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• 2008

The tongue diagnosis is a diagnostic method in the oriental medicine that uses shape, substance, coating, and movement of the tongue to determine the condition of health and disease characteristics in human. Since this information, however, could be affected by subjective sense and visual information, it is difficult to obtain the objective and reproducible results. This research aims at building a reproducible tongue diagnosis system using color chart that is attached close to the face contact region. The picture of color chart is taken simultaneously with a tongue and applied to color revision. The system, in addition, is focused on providing a clear tongue image through securing a sufficient photographing distance with a surface coating mirror. The lightning part which can suppress the reflection by sputum in maximum is implemented for the objectification and quantification of the tongue diagnosis system. The face contact region is designed for consideration of a testee's convenience. To evaluate the reproducibility of the system, the CVs (coefficient of variance, %) of $L{\ast}$, $a{\ast}$ and $b{\ast}$ of red, green and blue regions in color chart are calculated, respectively. The results of all CVs shows that the tongue diagnosis system is re liable and those consequences contribute to the objectification and quantification of the tongue diagnosis system.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.21 no.1
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• pp.1-7
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• 2017

In this paper, a design method for a compact stepped open slot antenna for an operation in the UWB band is studied. The proposed antenna is miniaturized by inserting L-shaped slots on the ground plane of the stepped open slot antenna through the creation of a resonance in the low frequency, and a strip director is appended to the antenna in order to increase the gain in the middle and high frequency regions. The effects of varying the length of the L-shaped slots, the distance between the director and the slot antenna, and the director length on input reflection coefficient and realized gain characteristics of the proposed antenna are analyzed. The optimized antenna with the size of $30mm{\times}30mm$ is fabricated on an FR4 substrate, and the experiment results show that the antenna has a frequency band of 3.02-11.04 GHz for a VSWR < 2, which assures the operation in the UWB band.