• Journal of Ginseng Research
• /
• v.33 no.3
• /
• pp.240-243
• /
• 2009

To better understand how to increase a ginseng grower's revenue, a 4-factor revenue determination model (RDM) of raw ginseng production (R=A Y Q P) was proposed. The total revenue (R) is a multiplicative function of four factors: cultivation area(A), unit yield (Y), quality grade (Q) and unit price (P). The A appears to be a pure capital factor. Y and Q are technological factors and P is social and market factor. When P is constant, the technological term (YQ) is the revenue per unit area (R/A) production efficiency per capital. The RDM appears to be a linear model between R and A with the slope [YQ]. RDM was applied to three farmers' raw ginseng production for assessment of its dependency on capital and technological factors.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2003.11a
• /
• pp.510-513
• /
• 2003

Our Zn diffusion into n-type $GaAs_{0.40}P_{0.60}$ used ampoule-tube method to increase IV. N-type epitaxial wafers were preferred by $H_2SO_4$-based pre-treatment. $SiO_2$ thin film was deposited by PECVD for some wafers. Diffusion times and diffusion temperatures respectability are 1, 2, 3 hr and 775, $805^{\circ}C$. LED chips were fabricated by the diffused wafers at Fab. The peak wavelength of all chips showed about $625{\sim}650\;nm$ and red color. The highest IV is about 270 mcd at the diffusion condition of $775^{\circ}C$, 3h for the wafers which didn't deposit $SiO_2$ thin films. Also, the longer diffusion time is the higher IV for the wafers which deposit $SiO_2$ thin films.

• Journal of radiological science and technology
• /
• v.35 no.1
• /
• pp.35-44
• /
• 2012

The goal of this study is to awaken about risk occurred by CT examination. For radio-technologists working at 'S medical center' located in Seoul, we investigated a recognition about dose and risk CT and normal X-ray examination according by working experience in hospital, experience about CT examination and radiation source. For subjects of investigation, radio-technologists working at 'S medical center' located in Seoul helped us. We collected 131 questionnaires for a test of hypothesis. Cronbach @ coefficients of questionnaires were 0.825988 and 0.767161 and a rejection rate of p-value was below 0.05. SAS 9.1(SAS Institute Inc., Cary, NC, USA.) statistic package was used for hypothesis test. We used Mann-Whitney test, Kruskai-Wallis test, Two sample T-test, Two sample T-test with Bonferroni's Correction and One-way ANOVA methods. P-values of hypothesis about dose of CT and normal X-ray examination were 0.2291 ~ 0.9663. p-values of hypothesis about risk were 0.1924 ~ 1.0000. All of hypothesis is over rejection rate(<0.05). This study shows that radio-technologists of S medical center recognized that CT has higher dose and risk than general X-ray examination.

• Journal of Dental Rehabilitation and Applied Science
• /
• v.21 no.2
• /
• pp.95-103
• /
• 2005

Purpose: Recently, various metal primers have been developed, and these are known to increase the bond strength between metal and relining resin. In this study, the change in bond strength according to amount of thermocycling was evaluated. Materials and Methods: In this study, 216 specimens were fabricated. Tokuyama Rebase $II^{(R)}$(Tokuyama Corp., Japan) and $Kooliner^{(R)}$(GC America Inc., Japan) as relining material, and MR. $Bond^{(R)}$(Tokuyama Corp., Japan) and Alloy $Primer^{(R)}$(Kuraray Medical Inc., Japan) as a metal primers were used. Using Ni-Cr and various metal surface treatment methods, resin was bonded and the change in bond strength during thermocycling was measured. The data was analyzed by one-way ANOVA, t-test(p<.05 level of significance). Results: When comparing the groups with only sandblasting, rapid decrease in shear bond strength could be seen. In the groups using Tokuyama Rebase $II^{(R)}$, with the exception of the 1000 and 2000 cycle groups, each group showed statistically significant decrease in shear bond strength(p<0.05). In comparison according to relining materials, $Kooliner^{(R)}$ showed higher shear bond strength than Tokuyama Rebase $II^{(R)}$ in all groups. In groups using MR $bond^{(R)}$, $Kooliner^{(R)}$ had higher shear bond strength than Tokuyama Rebase $II^{(R)}$ but, there was no statistical significance(p<0.05). In the other groups, $Kooliner^{(R)}$ showed significantly higher shear bond strength(p<0.05). There was significant difference between groups with sandblasting and metal primer treatments(p<0.05). In comparison according to metal primer materials, Alloy $Primer^{(R)}$ showed the highest shear bond strength but there was no statistical significance(p>0.05). According to the number of thermocycling cycles, when using Tokuyama Rebase $II^{(R)}$, there were no significant differences between the 0, 1000 and 2000 cycle groups regardless of the type of metal primer. There were no differences between the 2000 and 3000 cycle groups. When using $Kooliner^{(R)}$, regardless of the type of metal primer, there were no significant differences between the 0, 1000, 2000 and 3000 cycle groups(p>0.05). Conclusion: The use of metal primers showed increase in bond strength, and the stability after to thermocycling has been authenticated. Thus, the use of metal primers in relining and rebasing of metal frameworks is essential. But when selecting the material various physical properties should be considered.

• The Journal of the Korea Contents Association
• /
• v.18 no.8
• /
• pp.326-337
• /
• 2018

The purpose of this study was to investigate the levels of anxiety, empathy, ego-resilience, and clinical competency of nursing students, and to examine the relationship of the variables. The participants were 197 nursing students. Data were collected from December 3 to 15, 2017 by taking a survey and analyzed with SPSS WIN 19.0 program(SPSS Inc., Chicago, IL, USA). The results of this study were as follows: The mean score of anxiety was $2.16{\pm}.51$, empathy was $3.51{\pm}.36$, ego-resilience was $2.83{\pm}.44$, and clinical competency was $3.65{\pm}.48$. There was significant differences in clinical competency by satisfaction with major, satisfaction with clinical practice. There were a negative correlation between clinical competency and anxiety(r=-.37, p<.001), a positive correlation between clinical competency and empathy(r=.34, p<.001) and a positive correlation between clinical competency and ego-resilience(r=.49, p<.001). Variables such as ego-resilience, empathy, anxiety, satisfaction with major and satisfaction with clinical practice explained 35.6% of variance in clinical competency. According to these result, there is a need to develop interventions and programs to increase the ego-resilience and empathy and to reduce the anxiety for improving clinical competency in nursing students.

• Korean Journal of Mathematics
• /
• v.25 no.2
• /
• pp.229-246
• /
• 2017

This paper concerns barrier option of American type where the underlying price is monitored during only part of the option's life. Analytic valuation formulas of the American partial barrier options are obtained by approximation method. This approximation method is based on barrier options along with exponential early exercise policies. This result is an extension of Jun and Ku [10] where the exercise policies are constant.

• KLA journal
• /
• v.14 no.2
• /
• pp.17-21
• /
• 1973

(기자 주) 이 글은 랭캐스터(Lancaster, F.W.)교수가 미국 매리랜드주 베데스다(Bethesda)dpdlTsms 웨스타트연구소(Westat Research, Inc.)에서 발표한 논문(The Cost-Effectiveness Analysis of Information System)으로서, 미국정보과학회지(Journal of American Society for Information Science) Vol. 22, No. 1(Jan-Feb 1971), p.12-27에 수록되어 있다. 랭캐스터교수는 현재 미국 일리노이 대학교 대학원에서 도서관학을 강의하고 있다.

• Proceedings of the Korean Institute of Communication Sciences Conference
• /
• 2006.07a
• /
• pp.715-715
• /
• 2006

• Proceedings of the Korean Institute of Communication Sciences Conference
• /
• 2006.07a
• /
• pp.717-717
• /
• 2006

• Proceedings of the Korean Institute of Communication Sciences Conference
• /
• 2006.07a
• /
• pp.260-260
• /
• 2006