• Restorative Dentistry and Endodontics
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• v.18 no.1
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• pp.215-226
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• 1993

Color stability of tooth colored restorative resins is an important factor, particularly in anterior teeth restoration. The purpose of this study was to evaluate the color stability and opacity change of several light curing composite resins. Specimens of eight composite resins(Prisma AP. H., Brilliant Enamel, Charisma, Durafil, Helio Progress, Herculite XR, P-50 and Silux Plus) were divided into two groups : In Group 1, the specimens were polymerized by visible light curing unit for 60 seconds on both sides and in Group 2, the post-cured specimens were heat tempered by light/heat curing unit for 45 units(about 18 min.). All specimens were stored in distilled water at $60^{\circ}C$ for 30 days. The color characteristics($L^*,a^*,b^*$) and opacity of the specimens before and after immersion were measured by spectrocolorimetry and the total color difference(${\Delta}E^*$) and opacity change (${\Delta}Y%$) were computed. The results obtained were as follows : 1. SP and APH in both groups, DF, HP and HXR in Group 1 showed ${\Delta}E^*$-value above 2.0. 2. DF, HP, SP and HXR in Group 1 showed higher ${\Delta}E^*$-value than in Group 2, but the others had no significant difference. 3. The opacity of CH and HXR in Group 1, and of CH and BE in Group 2 decreased after immersion, while that of the others increased. 4. Opacity change of BE, P50 and HXR was significantly different between Group 1 and 2. These results suggest that color change in the post-cure heat tempered specimens by light/heat curing unit was smaller than that of the specimens polymerized by visible light curing unit. No clinically detectable opacity changes were noted for any materials in either goup.

• Restorative Dentistry and Endodontics
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• v.40 no.2
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• pp.128-135
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• 2015

Objectives: This study evaluated the effects of the resin thickness on the microhardness and optical properties of bulk-fill resin composites. Materials and Methods: Four bulk-fill (Venus Bulk Fill, Heraeus Kulzer; SDR, Dentsply Caulk; Tetric N-Ceram Bulk Fill, Ivoclar vivadent; SonicFill, Kerr) and two regular resin composites (Charisma flow, Heraeus Kulzer; Tetric N-Ceram, Ivoclar vivadent) were used. Sixty acrylic cylindrical molds were prepared for each thickness (2, 3 and 4 mm). The molds were divided into six groups for resin composites. The microhardness was measured on the top and bottom surfaces, and the colors were measured using Commission Internationale d'Eclairage (CIE) $L^*a^*b^*$ system. Color differences according to the thickness and translucency parameters and the correlations between the microhardness and translucency parameter were analyzed. The microhardness and color differences were analyzed by ANOVA and Scheffe's post hoc test, and a student t-test, respectively. The level of significance was set to ${\alpha}=0.05$. Results: The microhardness decreased with increasing resin thickness. The bulk-fill resin composites showed a bottom/top hardness ratio of almost 80% or more in 4 mm thick specimens. The highest translucency parameter was observed in Venus Bulk Fill. All resin composites used in this study except for Venus Bulk Fill showed linear correlations between the microhardness and translucency parameter according to the thickness. Conclusions: Within the limitations of this study, the bulk-fill resin composites used in this study can be placed and cured properly in the 4 mm bulk.

• Korean Security Journal
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• no.10
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• pp.53-77
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• 2005

This thesis analyzes the effectiveness of master's transformational and transactional leadership on organizational commitment as well as job satisfaction of private security, scrutinizes the difference in master's leadership according to social-demographic group. The sum of this thesis is as follows. To begin with, analyzed the difference of leadership style according to social-demographic characteristics of private security, it showed that monthly income is over 2.5 million won as well as people over 30 years old have higher transformational leadership than the others. That is, the older people's age is and the more someone gains his living, the higher he esteems and trusts his master who has charisma, personal concern and shows intellectual stimulus. And examined thoroughly the difference of organizational commitment as well as job satisfaction in accordance with social-demographic characteristics of private security, people who are 20-25 years old, are college graduates and employees who have worked for 2-3 years do well calculational commitment. It means that the younger he is and the lower academic background is, the higher calculational commitment is by the profit and loss which affects them. Secondly, inquired into consequence of leadership style on job satisfaction. Leadership of intellectual stimulus has negative effect on job satisfaction, whereas it has positive effect on conditional compensation. Exactly, if the master exhibits leadership that stimulate to improve an initiative, it reduces the job satisfaction. On the contrary, for the reason that his master indicates leadership that accompanies conditional compensation, job satisfaction tends to increase. Finally, judged from the effects of leadership style on organizational commitment, the charisma, the lower factor of transformational leadership affects to emotional commitment positively and then, it shows that employees tend to become attached to the organization and have a sense of oneness with it, if their master is able to show charismatic leadership. In conclusion, the private security companies pursue employees whose school career and payment is lower because of incidence in labor expense related with the profit and loss. Owing to it, employees are not satisfied with their job much. And also there is the change in increasing rate of job satisfaction according to business performance of the conditional compensation, i.e. a consideration, a promotion, etc., and the calculational commitment. Therefore, the university should try to focus on the researches for cultivate more professional manpower for business, the companies must try to make better deal, offer welfare for their employees to develop of the private security industry, to rise the job satisfaction of private security. And then, investigation to find private security's own level ought to be done by organic industry-academic cooperation of university and industries.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.11 no.6
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• pp.99-109
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• 2016

The purpose of this study is to review the relationship between corporate entrepreneurship and performance, and the moderating effect of CEO's transformational leadership in entrepreneurs'cooperative. In order to verify and achieve the purposes mentioned above, questionnaire data were gathered and analysed from 215 employees of entrepreneurs'cooperative in Metropolitan and kangwon-do vicinity. Multiple regression and multiple hierarchical regression analysis were applied to test the proposed hypotheses: 1) the relationship between corporate entrepreneurship(innovativeness, risk-taking, and proactiveness) and performance(sales volume, profit, employment), 2) the moderating effect of CEO's transformational leadership(charisma, individual consideration, intellectual stimulation) on the relationship between corporate entrepreneurship and performance. Empirical survey's findings are as follows; First, risk-taking appeared to be positively related with sales volume, profit, and employment. Proactiveness appeared to be positively related with sales volume and profit. But innovativeness appeared not to be significantly related with sales volume, profit, and employment. Second, CEO's transformational leadership appeared to be related with financial performance(sales volume and profit), but not to be related with employment. Charisma and individual consideration moderated positively the relationship between corporate entrepreneurship and financial performance(sales volume and profit). Intellectual stimulation moderated positively only the relationship between corporate entrepreneurship and profit.

• Restorative Dentistry and Endodontics
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• v.25 no.3
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• pp.399-406
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• 2000

The effect of inlay surface treatment on bonding was investigated when resin inlay was bonded to resin-modified glass-ionomer base with resin cement. For the preparation of glass-ionomer base, resin-modified glass-ionomer cement (Fuji II LC, GC Co., Japan) was filled in class I cavities of 7mm in diameter and 2mm in depth made in plastic molds. Eighty eight resin inlay specimens were made with Charisma$^{(R)}$ (Kulzer, Germany) and then randomly assigned to the four different surface treatment conditions: Group I, $50{\mu}m$ aluminium oxide sandblasting and silane treatment ; Group II, silane treatment alone ; Group III, sandblasting alone, and Group IV (control), no surface treatment. After a dentin bonding agent with primer (One-Step$^{TM}$, Bisco Inc., IL., U.S.A.) was applied to bonding surface of resin inlay and base, resin inlay were cemented to glass-ionomer base with a resin cement (Choice$^{TM}$, Bisco Inc., IL., U.S.A.). Shear bond strengths of each specimens were measured using Instron universal testing machine (4202 Instron, lnstron Co., U.S.A.) and fractured surfaces were examined under the stereoscope. Statistical analysis was done with one-way ANOVA and Dunkan's multiple range test. The results were as follows: 1. Sandblasting and silane treatment provided the greatest bond strength(10.56${\pm}$1.95 MPa), and showed a significantly greater bond strength than sandblasting alone or no treatment (p<0.05). 2. Silane treatment provided a significantly greater bond strength(9.77${\pm}$2.04 MPa) than sandblasting alone or no treatment (p<0.05). However, there was no significant difference in bond strength between sandblasting treatment and silane one (p>0.05). 3. Sandblasting alone provided no significant difference in bond strength from no treatment (p>0.05). 4. Stereoscopic examination of fractured surface showed that sandblasting and silane treatment or silane treatment alone had more cohesive failure mode than adhesive failure mode. 5. In relationship between shear bond strength and failure mode, cohesive failure occurred more frequently as bond strength increased.

• Restorative Dentistry and Endodontics
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• v.31 no.3
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• pp.147-152
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• 2006

The purpose of this study was to evaluate the influence of the AH-26 root canal sealer on the shear bond strength of composite resin to dentin. One hundred and forty four (144) extracted, sound human molars were used. After embedding in a cylindrical mold, the occlusal part of the anatomical crown was cut away and trimmed in order to create a flat dentin surface. The teeth were randomly divided into three groups; the AH-26 sealer was applied to the AH-26 group, and zinc-oxide eugenol (ZOE) paste was applied to the ZOE group. The dentin surface of the control group did not receive any sealer. A mount jig was placed against the surface of the teeth and the One-step dentin bonding agent was applied after acid etching. Charisma composite resin was packed into the mold and light cured. After polymerization, the alignment tube and mold were removed and the specimens were placed in distilled water at $37^{\circ}C$ for twenty four hours. The shear bond strength was measured by an Instron testing machine. The data for each group were subjected to one-way ANOVA and Tukey's studentized rank test so as to make comparisons between the groups. The AH-26 group and the control group showed significantly higher shear bond strength than the ZOE group (p<0.05). There were no significant differences between the AH-26 group and the control one (p>0.05). Under the conditions of this study, the AH-26 root canal sealer did not seem to affect the shear bond strength of the composite resin to dentin while the ZOE sealer did. Therefore, there may be no decrease in bond strength when the composite resin core is built up immediately after a canal filling with AH-26 as a root canal sealer.

• Journal of Korean Academy of Nursing
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• v.27 no.1
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• pp.228-241
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• 1997

Today's healthcare environment is changing, driven by demographic, environmental, social, political and technological forces. These rapidly changing healthcare environment and increasingly professional nursing practice indicate that identifying leadership characteristic of nursing leaders and executives is a vital importance in today's time and also mandate innovative leadership for nursing service. Therefore, the purpose of this study is to examined the transformational, transactional leadership styles of the Nurse Administrators. Also described are the relationships between these leadership styles and the job satisfaction. the organizational commitment of their subordinates. The sample consisted of sixteen mid-level nurse administrators, fifty head nurses and one hundred aid fifty-three staff nurses of 4 public & private University Hospitals and 1 General Hospital. Data for this study was collected from Sep. 20 to Oct. 5 by Questionnaire(Bass' MLQ, Job Satisfaction scale developed by Paula(1978), Organizational Commitment scale by Peter et at(1979). The data was analyzed by frequency, percentage, one-way ANOVA, Pearson's Correlation Coefficient with SPSS PC/sup ＋/ program. Major findings are as follows : Appropriate one-way ANOVA tests revealed that the differences for transformational and transactional leadership styles of nurse executives. mid-level nurse administrators, head nurses as perceived by their immediate subordinates were statistically significant(P<.05), The scores of transformational and contingent reward behaviors were declined of the mid-level nurse administrators, nurse executives. The transactional scores of nurse administrators were lower than trans- formational ones, which is a desirable findings. The result of this study, the head nurses were perceived as the highest transformational leader by their subordinates, and second was the mid-level nurse administrators. The nurse executives received the lowest transformational leadership scores from their subordinates. These results were opposit to the previous studies. And significant positive correlations were founded between transformational leadership including charisma, intellectual stimulation, individual consideration and contingent reward of nurse administrators and the job satisfaction, the organizational commitment of their subordinates. From the data, it can be concluded that transformational leadership style of nurse administrators promotes the job satisfaction, the organizational commitment of thier staff nurses. Therefore leader looks for potential motives in subordinates, seeks to satisfy higher need, and engages the full person of the subordinate resulting in a relationship of mutual stimulation and elevation.

• Journal of Fashion Business
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• v.8 no.1
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• pp.16-33
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• 2004

Up to now, image of femme fatale has undergone constant transformation to be inherited and developed through various genres of movies. With few exceptions such cases have represented sensuality of women by costumes with the most distinctive and exaggerated sexuality. Temptresses in movies are mostly drawn as extravagant and gorgeous one or a gloomy and dreary woman. Such an image is reinforced with make-up, hair style, accessories, attitude and manner of talking. The movie 'Chicago' is a musical film that crosses the boundaries of reality and fantasy with dancing and singing. Its lighting, stage setting, powerful and sexy dancing augmented already exaggerated and sensual costumes. Following is the analysis of costumes for two heroines as images of femme fatale. Strong contrast of color among black, red and blue on see-through & stickingly tight body suit signifies liberal mind and arrogant charisma of Velma. The contrast, haughty gestures, cropped black hair and thick makeups represent sex appeal, aggressive image, and fearlessly determined character of femme fatale. Roxie wears decent dresses in front of public and gorgeous stage costume in fantasy to convey two images of bad girl and angel. Her body suit, showing off lustering materials and dazzling bead decoration, is rather loose but still displays her bodyline to emphasize sexiness for representation of desire in fantasy. Chastity and innocence are implied with the decency of dresses in reality. They were specially chosen to draw public sympathy and indicate cunning disguise of Roxy who desperately wants to realize her desire. These dauntless costumes, which sufficiently express inside aspirations of Velma and Roxie later denote open and realistic social yearning rather than fatal desire hidden behind sensual beauty. It doesn't exist as imperfect, unrealistic and socially disdainful ambition as the image of femme fatale of paintings and movies did before in history. Femme fatale is expressed with deep cleavage, silk dresses that explicitly display bodyline, sexiness of mesh stockings with garter belts. All of these won't be utilized as a negative tool to seduce and destroy someone anymore but rather, they should represent rightful and fair nature of humans such as men's curiosity who secretly steal a look at them or female sexuality that women spontaneously want to show off.

• Restorative Dentistry and Endodontics
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• v.24 no.4
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• pp.585-603
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• 1999

Esthetic availabilities used as an esthetic restorative maternals can be determined by the optical coincidence among materials, enamel and dentin. Enamel is highly translucent. That's why esthetic materials need to correspond the close translucency of enamel. But the translucent materials are affected by the background color. So it should be predicted that the color of estorative materials depend on the any thickness and the spectral reflectance of the background on which they are placed. The object of this investigation, under above hypothesis, was to determine and analyze how they affect the final color according to the thickness, translucency and background color (white, black and dentin) fill three commercial light cured composite resins(Charisma, Spectrum TPH and Z100). And correlation was analyzed to find out the possibility of the prediction when using the certain background color and thickness of materials. Followings are the result 1. The I shade of CHA showed the lowest contrast ratio($Co_7$) while the B3 shade of Z100 showed the highest contrast ratio(p<0.05). 2. The value of $L^*$ and $b^*$ on the white and dentin background is increased with decreasing thickness. And there are significant relationships between increasing thickness and each value(R>0.085). But there is a little change of $L^*$ and $b^*$ value on the black background regardless of the thickness(p>0.05). 3. For the $a^*$ value, there was little difference in values as a function of thickness and changed irregularly regardless of thickness in all background. 4. The pattern of increasing value of $L^*$ and $b^*$ with decreasing thickness was similar to the group of white and dentin background. In both dentin one showed lesser change of value. 5. The values of $L^*a^*b^*$ measured on the different background with same thickness showed the recognizable color difference(${\Delta}E^*$>2) when the thickness was below 2.6mm. 6. Contrast ratio was increased with increasing thickness with significant relationship (R>0.9). 7. Spectral reflectance of composite resins that calculated from Kubelka-Munk equation was showed little difference compared with observed value w1th decreasing thickness.

• Journal of the korean academy of Pediatric Dentistry
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• v.33 no.2
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• pp.281-289
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• 2006

Topical fluoride application for children is a widely performed procedure in the field of Pediatric Dentistry for its dental caries prevention effects However, it is recently recognized as having some unwanted effects on several esthetic restorative materials, the author immersed glass ionomer cement, compomer and composite resin specimens in APF gel and measured the surface roughness and also, examined the specimens under the scanning eletron microscope. The followings are the results: 1. In the specimens of glass ionomer cement and compomer, APF gel 4 minute immersion group and pH cycling group show statistically significant increased surface roughness than artificial saliva immersion group (p<0.01). 2. There was no statistically significant surface roughness for composite resin in all group (p>0.05). 3. When the specimens were examined under scanning electron microscope, the surface change were in the order of glass ionomer cement, compomer, composite resin and also in the order of pH cycling group, APF gel 4 minutes immersion group, artificial saliva immersion group.