• Journal of Korea Multimedia Society
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• v.8 no.1
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• pp.79-87
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• 2005

In e-commerce applications, a public key cryptosystem is an important and indispensible element for the basic security operations such as authentication, digital signaturing, and key distribution. In wired network environments, the public key infrastructure certificate, which is based on X.509 specification, has been widely used. On the other hand, it still remains difficult to use the certificate information in wireless network environments due to the inherent limitations of the hand-held devices such as low computational power and short battery life. In this paper, we facilitate a codesign approach by implementing a software public-key cryptosystem and classifying its internal computation overheads quantitatively using a software profiling technique. Moreover, we propose a method to analyze the profiled data and apply it to the problem of software/hardware partitioning in a codesign approach. As an illustrative example, we analyze the computational overheads of an EC-Elfagamal application and examine a critical computational path.

• Polymer(Korea)
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• v.33 no.5
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• pp.509-513
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• 2009

For examining an effect of lithium bromide on structure and property of chitosan/fibroin blend, we investigated the structural characteristic of chitosan/fibroin blend films using solution with lithium bromide which was removed during a casting. The chitosan/fibroin blend formed a complex with the dissolved bromine/lithium ions. The crystalline phase of the complex was found in the blend film at LiBr concentration of 0.6 mol/L. The degree of crystallization was decreased with increasing the concentration of LiBr. The hydrated crystalline phase of chitosan was formed in the blend film that lithium bromide was removed in the process of casting by neutralization and osmotic action. The crystallinity of this film was increased largely as compared with that of the film without lithium bromide. The complexed blend film formed hydrogel absorbing plenty of water.

• Korean journal of food and cookery science
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• v.25 no.5
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• pp.545-556
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• 2009

The purposes of this study were to understand the influence of perceived service quality in Korean food restaurants on customer satisfaction and behavioral intention and to empirically analyze whether trust plays a mediating role between both the relations of the perceived service quality and customer satisfaction and the perceived service quality and behavioral intention. Based on total 303 samples obtained from empirical research, this study reviewed the reliability and fitness of the research model and verified a total of 5 hypotheses using the Amos program. The hypothesized relationships in the model were tested simultaneously by using a structural equation model(SEM). The proposed model provided an adequate fit to the data, $X^2{_{(df131)}}$ = 536.566, p<.01, RMR .126, GFI .841, NFI .896, CFI .919, RMSEA .101. The SEM results showed that the perceived service quality(${\beta}$= .823, t = 9.392, p<.001) had a significant positive effect on trust had a significant positive effect on trust, and trust had a significant positive effect on customer satisfaction(${\beta}$ = .730, t = 14.202, p<.001) and behavioral intention(${\beta}$ = .239, t = 3.362, p<.001). Also, customer satisfaction had a significant positive effect on behavioral intention(${\beta}$ = .509, t = 6.978, p<.001). In addition, the effect of the perceived service quality in Korean food restaurants upon behavioral intention was found to be partially mediated by the trust.

• Journal of the Korean Society of Food Culture
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• v.9 no.5
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• pp.509-524
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• 1995

Consumer's perceptions of the quality of food and food-related servcie were surveyed through questionnaires by 672 adults randomly selected from 20 industrial foodservice in Pusan Kyeung Nam area. Data from consumers were analyzed by using $SPSSPC^+$ program in terms of $x^2-test$, oneway ANOVA, t-test. The results are as follows: 1) Among the food characteristics, the mean rating for temperature of food was 3.18 over 5, for quality of food vs. food price 2.97, for fresshness 2.96, for taste 2.86, and for combination of colors 2.73; 2) In the food-related service, the mean rating was 3.20 for cleanliness of dishes, 3.18 for quality of dishes, 3.01 for varity of food items, 2.95 for courtesy of employees, and 2.57 for availability of favorite food. 3) Self-operated foodservice showed higher mean ratings in nutrition of food, quality of food vs. food price, and availability of favorite food than does the contracted one. 4) The rice (85.0%) and the kimchi (81.4%) were right in amount, but the soup (42.5%) and the side dish (49.0%) were not enough. 5) In seasoning of food, 45.2% of the respondents agreed that the salty taste and the amount of MSG were just right. However, 38.0% and 37.9% of them responded that the salty tast was strong and the amount of MSG was much. 6) The respondents mostly required the improvement of the taste of side dish, nutrition of food, sanitation of food, and variety of menu items.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.31 no.7
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• pp.502-509
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• 2018

Epitaxial ZnO nanowires (NWs) were synthesized on sapphire (001) substrates using a hydrothermal process. The effects of the pH value of the precursor solution on the structural and optical properties of the resulting NWs was studied. The epitaxial relationship and the domain matching configuration between the sapphire (001) substrate and the as-grown ZnO NWs were determined using synchrotron X-ray diffraction measurements. The (002) plane of $w{\ddot{u}}rtzite$ ZnO NW grows in the surface normal direction parallel to the sapphire (001) direction. However, three types of in-plane domain matching configurations were observed, such as the on-position, $30^{\circ}$-rotated position, and ${\pm}8.5^{\circ}$-rotated position relative to the on-position, which might be attributed to inheriting the in-plane domain configuration of the ZnO seed layer.

• The Journal of Information Technology
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• v.7 no.1
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• pp.43-56
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• 2004

The purpose of this paper is to study the send and receive of the message in the TEDI System. The TEDI System replaces a series of trade documents with electronic date, and it realizes secure and reliable transactions of data among parties by means of open networks, such as the Internet. The TEDI system is composed of Web browsers, TC Serves, a RSP Server, and Certification Servers. TEDI has development the system and legal frame work. Exporters, importers, carriers, banks insurance and companies those who engage in the trade releated business have tested TEDI system and evaluated the legal frame work from the practical point of view. TEDI is now refining the system and preparing for the service. A fundamental feature of the TEDI System is the attribution to participants of data messages through public key certificates issued by certification authorities that allow for verification of digital signatures. Access to servers maintained by such certification authorities also takes place through the internet. In principle, certificates used by any reputable certification authority may be employed as long as they are compatible with X.509 V3.

• Journal of Korean society of Dental Hygiene
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• v.11 no.4
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• pp.499-509
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• 2011

Objectives : The purpose of this study was to provide some information on down-to-earth oral health policy to improve the systemic health involving oral health and the quality of life in Korean adults. Methods : The third-year data of the 4th National Health and Nutrition Survey in 2009 were analyzed, and $x^2$(Chi-square) test was carried out to see whether there would be any gaps in subjective oral health status according to demographic characteristics, systemic health state, frequency of eating between meals and oral health behavior. In terms of the DMFT index, one-way ANOVA was utilized, and then Scheffe post-hoc analysis was conducted. Besides, multiple regression analysis was made to grasp the relationship of oral health behavior to subjective oral health state and the DMFT index. Results : The demographic characteristics, systemic health status and oral health behavior had a significant relationship to both of subjective oral health status and the DMFT index. As a result of analyzing the relationship of oral health behavior to subjective oral health state and the DMFT index, the subfactors of oral health behavior exerted a significant independent influence on subjective oral health status and the DMFT index. Conclusions : The findings of the study suggest that in order to promote the oral health of adults, preventive measures should be taken, and systematic oral health education should be provided. As there is an increase in the elderly population in Korea, the successful implementation of senior oral health plans and the development of oral health programs geared toward adults are both required.

• Korean Journal of Materials Research
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• v.7 no.6
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• pp.505-509
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• 1997

FRAM(Ferroelectric Random Access memory)에의 응용을 위해 rf magnetron sputtering법을 이용하여 SrB $i_{2}$T $a_{2}$ $O_{9}$(SBT)박막을 증착하였다. 사용된 기판은 Pt/Ti/Si $o_{2}$Si이었으며 50$0^{\circ}C$에서 증착한 후 80$0^{\circ}C$의 산소 분위기 하에서 1시간 동안 열처리하였다. 증착시 증착 압력을 변화시켜 가면서 이에 따른 특성의 변화를 고찰하였다. 박막내의 Bi와 Sr의 부족을 보상하기 위해 20mole%의 Bi $O_{2}$와 30mole%의 SrC $O_{3}$를 과잉으로 넣어 타겟을 제조후 사용하였고 박막들의 두께는 300nm의 두께를 가지며 증착압력에 따라 다른 미세 구조르 보였다. 10mtorr에서 증착한 박막의 조성은 S $r_{0.6}$B $i_{3.8}$Ta/ sub 2.0/ $O_{9.0}$이었다. 이 SBT 박막의 잔류 분극(2 $P_{r}$)과 보전계(2 $E_{c}$)값은 각각 인가 전압 5V에서 18.5 $\mu%C/$\textrm{cm}^2$과 150kV/cm이었고, signal/noise비는 3V에서 4.6을 나타내었다. 5V의 bipolar pulse하에서 $10^{10}$cycle까지 피로 현상이 나타나지 않았으며, 누설 전류 밀도는 133kV/cm에서 약 1x$10^{-7A}$$\textrm{cm}^2$의 값을 보였다.을 보였다.

• Journal of Radiation Industry
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• v.6 no.3
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• pp.223-229
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• 2012

In this study, we investigated the biological damage and stress responses induced by ion beam (proton beam) irradiation as a basis for the development of protective measures against space radiation. We examined the biological effects of proton beam produced by MC-50 cyclotron at KIRAMS on the cultured cells and mice. The proton beam energy used in this study was 34.9 MeV and the absorption dose rate for cells and mice were $0.509Gy\;sec^{-1}$ and $0.65Gy\;sec^{-1}$, respectively. The cell survival rates measured by plating efficiency showed the different sensitivity and dose-relationship between CHO cells and Balb/3T3 cells. HGPRT gene mutation frequency in Balb/3T3 was $15{\times}10^{-6}Gy^{-1}$, which was similar to the reported value of X-ray. When stress signaling proteins were examined in Balb/3T3 cells, $I{\kappa}B-{\alpha}$ decreased markedly whereas p53, phospho-p53, and Rb increased after proton beam irradiation, which implied that the stress signaling pathways were activated by proton beam irradiation. In addition, cellular senescence was induced in IMR-90 cells. In the experiments with C57BL/6 mouse, the immune cells (white blood cells, lymphocytes) in the peripheral blood were greatly reduced following proton beam irradiation whereas red blood cells and platelets showed relatively little change. These results can be utilized as basic data for studying the biological effects of proton beam using MC-50 cyclotron with respect to proton therapy research as well as space radiation research.

• Research in Community and Public Health Nursing
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• v.29 no.4
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• pp.499-509
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• 2018

Purpose: The purpose of this study is to identify differences in disaster awareness, disaster preparedness, and nursing knowledge and practices between Korean and Japanese nursing students. Methods: The study subjects were 4th grade nursing students who completed their nursing education in Korea or in Japan. 359 students from Korea and 135 students from Japan participated in this study. Data were analyzed using IBM SPSS 21.0. The $x^2$ test and the t-test were used to analyze the homogeneity of subjects' general characteristics and disaster-related characteristics. The comparison between the Korean and Japanese nursing students in disaster awareness, disaster preparedness, and nursing knowledge and practices were conducted using ANCOVA. Results: The Korean nursing students' disaster awareness, disaster preparedness, and nursing knowledge and practice were different from their Japanese counterparts'. The Korean nursing students recognized that the system of disaster management in Korea was insufficient and the negligence of management was one of the causes of the disaster. They wanted to participate in activities for disaster preparedness education and management. Conclusion: A disaster nursing curriculum dealing with disaster awareness, disaster preparedness, and nursing knowledge and practices, should be developed, implemented,and evaluated particularly for Korean nursing students.