• Journal of dental hygiene science
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• v.12 no.5
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• pp.511-515
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• 2012

The aim of this study was to investigate the effects of dental plaque control depending on the detergent foods. Study design was a nonequivalent control group design. Study subjects were 14 males (38.8%) and 22 females (61.1%), the age of 20.6 years old. It was conducted from March 7 to June 13, 2012. The Patient Hygiene Performance index (PHP index) was measured as a dependent variable. Detergent foods were cucumber, pear, carrot, and peach. The PHP index of detergents foods were compared using ANOVA. Paired t-test was performed. SPSS ver. 18.0 was used for the data analysis. All detergent foods which cucumber ($2.85{\pm}1.01$), pear ($2.82{\pm}0.93$), peach ($2.48{\pm}1.12$), and carrot ($2.75{\pm}0.68$) was a significant decrease in plaque index (p<0.05). However, there was no significant difference among detergent foods. Detergent foods are effective in dental plaque control. However, no difference was shown depending on the detergent foods.

• Journal of the Korea Concrete Institute
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• v.18 no.6 s.96
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• pp.801-809
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• 2006

Epoxy resin has widely been used as adhesives and corrosion-resistant paints in the construction industry for many years, since it has desirable properties such as high adhesion and chemical resistance. Until now, in the production of conventional epoxy cement mortars, the use of any hardener has been considered indispensable for the hardening of the epoxy resin. However we have noticed the fact that even without any hardener, the hardening process of the epoxy resin can proceed by the action of hydroxides in cement mortars. As a result the disadvantages of the two-component mixing of the epoxy resin and hardener have been overcome. The purpose of this study is to evaluate the mechanical properties and durability of epoxy cement mortar without a hardener exposed at indoor and outdoor for one year. The epoxy cement mortars without and with a hardener were prepared with various polymer-cement ratios, and tested for weight change, flexural and compressive strengths, water absorption, carbonation depth and pore size distribution. Especially, the basic properties of the epoxy cement mortars without hardener are discussed in comparison with ones with the hardener. From the test results, it is concluded thai the epoxy cement mortars without a hardener exposed at indoor and outdoor for one year have higher strength and better durability than ones with the hardener within the polymer-cement ratios of 10 to 20%.

• Journal of the Korean Institute of Gas
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• v.26 no.6
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• pp.30-36
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• 2022

In commercial transactions of energy sources using hydrogen charging stations, high-accuracy flow meters are needed to prevent accidents such as overcharging due to inaccurate measurements and to ensure transparency in hydrogen commercial transactions through accurate measurements. This research developed a Corioli-type flowmeter prototype and conducted a risk assessment to prevent accidents during a process change comparison experiment for existing charging stations to verify the measurement performance. A process change section was defined for the installation of measurement facilities for empirical experiments and HAZOP was conducted. In addition, JSA was also conducted to secure the safety of experimenters, such as preventing valve mis-opening during empirical experiments. Measures were established to improve the risk factors derived through HAZOP, and work procedures were established to minimize human errors and ensure the safety of workers through JSA. The design change and system manufacturing for the installation of the metering system were completed by reflecting the risk assessment results, and safety could be confirmed through the performance comparison test of the developed meter prototype. The developed prototype flow meter showed a total of 30 flow measurements under the operating conditions of 70 MPa, and the average error was -1.58% to 3.96%. Such a metering error was analyzed to have the same performance as a flow meter installed and operated for commercial use.

• The Journal of the Korea Contents Association
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• v.17 no.1
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• pp.12-24
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• 2017

The purpose of this study was to evaluate the effects of personality virtue education program using visual media for college students. This program was run in parallel with "Educational Psychology" lecture from August 30th through December 4th, 2015. The subjects of study were 348 freshmen of nursing department in J college. The methodology of this study was nonequivalent pretest-posttest control group experimental design. The researcher carried out pretest for experimental group and control group both before program execution by KEDI Personality Inventory and repeated the test afterwards to measure the effects of the program. The data analysis was implemented by SPSS 22.0. The ANCOVA was used to verify the hypothesis. The result showed that all personality virtues(self-respect, integrity, consideration communication, responsibility, etiquette, self-control, honesty courage, wisdom, justice, citizenship) scores were improved significantly after the program. In conclusion, virtue-centered personality education can make students realize and internalize the value of virtues and have motivation and will to act, when they empathized with visual media on the various situation and learned repeatedly in integrated curriculum.

• Culinary science and hospitality research
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• v.21 no.1
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• pp.15-29
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• 2015

The purpose of this study is to identify the effect of job satisfaction on job performance and to examine the moderating effects of employment type of the employees in franchised Korean restaurants. The questionnaire was distributed to the employees in Korean restaurants having abroad branches of the 300 distributed questionnaire, and 271 copies were used in the analysis by exploring factor analysis, reliability analysis, correlation analysis, multiple regression and hierarchical moderated regression analysis through SPSS ver. 18.0. The results of the study were as followed; First, job satisfaction, the work and superior factor have positive influence on job performance, but wages and promotion factor have negative influence. Second, the employment type has the partially moderating effects between job satisfaction and job performance with interactive term(superior$^*$ employment type). On the basis of these results, it is suggested that the company has fair criteria for evaluating systems and reward program to the employees regardless of employment type. This study has the limitations of simple variable and employment type.

• 한국노년학
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• v.30 no.3
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• pp.815-830
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• 2010

This study is a nonequivalent control group pretest-posttest study to determine the effects of a make up program on the self-esteem and anxiety of the elderly female dementia patients. This research was done between April 13th and May 1st, 2009. The subjects were 41 dementia patients in an elderly hospital in Honam Area. Twenty dementia patients in the experimental group got the make up measures during the two week experimental period and twenty one dementia patients in the contrast group didn't get any measure during the two week period. Make up measures were given to the experimental group 10 times for the two week period. This study used the self-esteemscale which was developed by Rosenberg(1965) and was translated and modified by Jeon Pyung Je(1974) into Korean. The anxiety status scale which this study used was developed by Spielberger(1970) and was translated and modified by Kim Jeong Taek(1991) into Korean. Collected data were analyzed with SPSS Win 12.0. T-test and multivariate analysis were done to test the hypothesis. This study also used a method of observation. The results of this study are following. After the two week make up measures, the experimental group had more self esteem and less anxiety status than the contrast group. The differences were statistically significant. The result of the observation also supported the research hypothesis. Based on this result, we suggest the make up program as an appropriate and useful nursing care intervention program for female dementia patients.

• Journal of the Korean Society of Clothing and Textiles
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• v.31 no.12
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• pp.1761-1771
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• 2007

The artificial exaggeration of stage costumes is thought to be one of the major techniques of enhancing dramatic expression on stage, whichever for visual impact or symbolic effect of dramatization. In the history of stage dressing, a variety of styles has been tried using different materials and production techniques. This may be reviewed as an effort to express dramatic effects more effectively. As this trend became obvious in Europe after the Second World War, this study analyzes the stage costume to deepen our understandings of the role of costumes in expressing dramatic effects. To accomplish this, we first summarized the history of stage costume materials and technical advance and chose five major cases representing the history of stage costume since the Second World War in Europe based on aesthetic and creative aspects: 1) Simplified stage of Jacques Copeau, 2) Stylized stage of Bertolt Brecht, 3) Essential stage of Grotowski, 4) Measured stage of Robert Wilson the Master, and 5) Post-dramatic stage of Philippe $Decoufl\'{e}$. In each of particular case, the historical, material and dramatic contexts were examined as well as different material-effects. The results are as followings: 1) Costume for Copeau's simplified stage: its simplicity plays a supporting role to the gesture of actors(intensifying effect). 2) Costume for Brecht's stylized stage: the artificial stylization integrates into the play with the importance approximately equal to the actors's acting. 3) Costumes for Grotowski's essential stage: costumes disappeared to emphasize only actor's presence on stage. 4) Costumes for Robert Wilson's measured stage: costumes made concrete impression to the extent of obtaining the same importance of actor's body among other stage art elements(lighting, sound, props, actor, text, etc). 5) Costumes for Decoufle's post-dramatic stage: costumes in the era of multi technology possess multi functional aspects that surrogate actors' body. This study suggests that stage costumes take an important part in dramaturgy to the extent that the intent of dramaturgy can be induced enough from stage costume. Thus, costume makers are expected to incorporate the appropriate dramatic factor more than before.

• Journal of the Korean Magnetics Society
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• v.26 no.6
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• pp.219-225
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• 2016

In this study, for assessment of degenerative knee joint cartilage disease we acquired images by fat suppressed 3D spoiled gradient recalled (SPGR) and fat suppressed 3D $T2^*$ weighted imaging techniques. To do a quantitative evaluation, the knee joint cartilage was divided into medial femoral cartilage (MFC), medial tibial cartilage (MTC), lateral femoral cartilage (LFC), lateral femoral cartilage (LFC) and patella cartilage (Pat) to measure their respective signal intensity values, signal-to-noise ratio, and contrast-to-noise ratio. As for the measured values, statistical significance between two techniques was verified by using Mann-Whitney U-Test. To do a qualitative evaluation, two radiologists have examined images by techniques after which image artifact, cartilage surface, tissue contrast, and depiction of lesion distinguishing were evaluated based on 4-point scaling (1: bad, 2: appropriate, 3: good, 4: excellent), and based on the result, statistical significance was verified by using Kappa-value Test. 3.0T MR system and HD T/R 8ch knee array coil were used to acquire images. As a result of a quantitative analysis, based on SNR values measured by using two imaging techniques, MFC, LFC, LTC, and Pat showed statistical significance (p < 0.05), but MTC did not (p > 0.05). As a result of verifying statistical significance for measured CNR value, MFC, LFC, and Pat showed statistical significance (p < 0.05), while MTC and LTC did not show statistical significance (p > 0.05). As a result of a qualitative analysis, by comparing mean values for evaluated image items, 3D $T2^*$ weighted Image has indicated a slightly higher value. As for conformance verification between the two observers by using Kappa-value test, all evaluated items have indicated statistically significant results (p < 0.05). 3D $T2^*$ weighted technique holds a clinical value equal to or superior to 3D SPGR technique with respect to evaluating images, such as distinguishing knee joint cartilages, comparing nearby tissues contrast, and distinguishing lesions.

• Journal of the Korea Convergence Society
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• v.7 no.4
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• pp.51-58
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• 2016

The purpose of this study was to examine the effects of clinical convergence self-directedness practice learning program on self-directedness and competency in fundamental nursing skills in undergraduate nursing students. The study design was a non-equivalent pre-post quasi-experimental design. The participants were 80 nursing students in D city. The experimental and control groups were randomly assigned with 40 participants in each group. Interventions for the experimental group were visiting clinical practice, video recording and students' self-debriefing of what they did over the 5 days. Self-directedness and competency in fundamental nursing skills were measured 2 times (pre-, and post-intervention) over the 5 days. Independent t-test, Mann-Whitney U test and chi-square test were used for data analyses. There was statistically significant difference for self-directedness(t=12.93, p=.001) and competency in fundamental nursing skills(t=8.34, p=.021). Results indicate that self-debriefing method using video recording is an effective learning way to improve Self-directedness and competency in fundamental nursing skills in nursing students.

• Proceedings of the KWS Conference
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• 2010.05a
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• pp.24-24
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• 2010

마찰교반접합법은 특정한 회전수로 회전하는 용접 툴을 이용하여 접합하고자 하는 피접합재의 맞댄면에 삽입시킨 후 툴을 이동시키거나 혹은 시편을 견고하게 고정시킨 장치(backing plate)가 움직여 고상 상태에서 접합이 이루어진다. 알루미늄, 마그네슘 등 비교적 융점이 낮은 저융점 재료의 재료에 처음 적용이 되어 많은 연구가 활발히 진행되었고 타 용접방법에 비해 우수한 접합특성을 나타내었다. 최근 이러한 마찰교반접합은 이러한 저융점 재료를 넘어서 스틸, 타이타늄, 니켈 등과 같은 고융점 재료 등에 대한 적용이 늘어나고 있다. 마찰교반접합을 이용하여 이러한 고융점 재료의 접합 경우 내마모성 및 내열성 등의 내구성이 갖추어진 툴과 이러한 툴을 냉각시킬 수 있는 냉각 장치 등이 필요로 하나 경제적 측면이나 접합부의 우수한 특성 등을 고려 할 때 그 적용 및 발전 가능성이 매우 높다고 볼 수 있다. 2상 스테인레스 강은 금속 조직적으로 페라이트와 오스테나이트 상이 거의 1:1의 동등한 비율로 매우 미세하게 결합된 구조를 가지고 있다. 또한 이상 스테인레스 강은 각상의 개개의 특성에 기인하여 염소 분위기에서 응력부식 저항성이 우수하고, 공식과 틈부식에 대한 저항성이 매우 뛰어나다. 그리고 이상 스테인레스 강은 비교적 고가인 Ni이 일반 오스테나이트 스테인리스 강의 약 1/2의 수준으로 적게 포함이 되어 경제적인 이점을 지니고 있으며 또한 용접성이 좋아 산업계의 수요는 현재 점차 증가하고 있는 상황이다. 하지만 이러한 이상 스테인리스 강은 용접 후 페라이트 상의 조대화, 그리고 페라이트 상의 분율이 오스테나이트 상의 분율보다 높아지게 되어 용접부에서의 저온 인성 감소 및 내식성 저하 등의 문제가 발생하게 된다. 그리하여 용접 시 이러한 문제점을 해결하기 위해서는 입열량의 조절이 가장 필요로 하는 것으로 알려져 있다. 본 연구에서는 마찰교반용접을 이용하여 두께 3mm의 대표적인 이상 스테인리스 강인 SAF2205 스테인리스 강에 대해 맞대기 마찰교반접합을 실시하였다. 툴 회전속도를 변수로 하여 접합을 실시하였으며 접합 시 툴은 $Si_3N_4$ 툴을 사용하였다. 접합 후 외관상태 점검, 미세조직 관찰, 경도 및 인장강도 측정 등의 실험을 실시하였고, 이러한 결과를 이용하여 미세조직과 기계적 특성과의 관련성을 조사하였다.