• Restorative Dentistry and Endodontics
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• v.28 no.2
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• pp.127-133
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• 2003

The object of this study was to compare the microleakage between various composite resin systems of multistep, one-bottle, and self-etching systems using electrical conductivity. After making class V cavities ($4{\times}3{\times}1.5{\;}mm$ around CEJ), they were bulk filled with three kinds of resins of A3. Teeth were storaged in a saline solution for one day, after then, they were finished and polished using Sof-Lex system. Another stress of thermocycling was made for 500 times from $5^{\circ}{\;}to{\;}55^{\circ}C$ with each dwelling time of 10 seconds. Electrical conductivity (microamphere, $\mu\textrm{A}$) was checked four times: before and after cavity preparation, after filing, after thermocycling. One-way ANOVA and 95% Scheffe Post Hoc test was used for checking any statistical difference among groups. Another 95% Paired Samples T-test was also used for estimating any significant difference within group after cavity filling or thermocycling. The results were as follows: 1 Every specimen showed various range of microleakage after filing. There was, however, no difference between composite resin systems. 2. All composite resin systems showed marked increase in microleakage with a thermocycling (p<0.05), there was, however, no difference between composite resin systems. 3. Although there was no significant difference between groups (p=0.078), one-bottle and self-etching systems seemed to be unstable than multistep system. Within the limits of this study, it was concluded that much more consideration should be needed when using thermally unstable one-bottle and self-etching systems that have multi-advantages from simplified step. More studies will be needed to solve these kinds of problems.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.16 no.4
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• pp.64-75
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• 2017

Previous count models using fixed parameter can not consider the unobserved heterogeneity, as the standard error of the count value is underestimated, excessive t-values are derived thereby reducing the reliability of the model. Also, the study of unsignalized intersections are inadequate because of the difficulty of collecting data and statistical limits for accurate analytical processes compared to the signalized intersections. The purpose of this study is to analyze the factors affecting traffic accidents by constructing the count model using random parameters, and it aimed to distinguish between existing studies based on the rural unsignalized intersections. As a result of the analysis, 7 variables were presented as significant variables, and 2 variables(presence of crosswalk, speed limit) were presented as random parameter.

• Journal of Korean Public Health Nursing
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• v.14 no.2
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• pp.271-280
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• 2000

The purpose of this study was to identify the health status of elderly. Subjects were 132 older people who live in home and institution located Taejon metropolitan city. Data were collected from May 1997 to April 1998. To obtain data about health status of elderly. pulse, respiration, systolic and diastolic blood pressure. grip strength. pinch pressure. flexibility, arm circumference. triceps skin fold thickness were measured. Data were analyzed for frequency. percentage. t-test using SPSS pc+ program. The results were as follows: 1. $74.4\%$ of subjects was perceived as 'good' in their health status. 2. Mean pulse, mean respiration, systolic and diastolic blood pressure were with in normal limits. There were no statistical differences between men and women in pulse, respiration, systolic and diastolic pressure. 3. Left and right grip strength were 24.89 psi and 25.23psi. The grip strength in men was higher than that of women. It showed statistically difference between men and women in grip strength. 4. Left and right pinch pressure were 7 pound and 7.32 pound. There was statistically difference of pinch pressure between men and women. 5. left flexibility was better than right flexibility of subjects. There was no statistically significant difference between men and women in flexibility. 6. Arm circumference was 24.96cm and there was no statistically significant difference between men and women. 7. Mean skin fold thickness was 12.83 em. Skin fold thickness in men was lower than that of women. It showed statistically difference between men and women. From these results, further study should be considered gender differences in health status of elders and carried in larger sample than this study.

• Journal of Agricultural Extension & Community Development
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• v.18 no.3
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• pp.351-384
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• 2011

The purpose of this study is to look at the case of the German compensation system for farmers' accidents and to build a basic scheme in our country's compensation system for farmers' accidents. When you view examples of Germany, the social insurance scheme for farmers accidents in korea should be design as an independent institution from the existing industrial accident insurance, and it comes to relationships with other social insurance system, preferably with complementary personalities. A general rule of the compensation system applies to all farmers in principle but the coverage limits part-time farmers. Financial burden consists of the mix of insurance premium and state aid. The type and level of benefits is similar to the current industrial accident insurance, which give priority to places on economic security for keeping farmworks, such as cost for using temporary farmers, rather than income loss. In terms of financial system, pay-as-you-go system would be better because of immediate payment with the introduction of the compensation system. The compensation system might be managed and administrated by the existing nationwide organization. Of course, for operating of system review and further research on the technical details such as premium issues and funding problems of government support, the exact classification of the target coverage, premiums based on estimated income for the farmers' estimation, the exact statistical data on the accumulation of agricultural disaster is needed.

• Journal of the Economic Geographical Society of Korea
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• v.13 no.1
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• pp.89-110
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• 2010

Relying on the concept of "multicultural space", this paper aims to examine the ways in which the adaptation of foreign professional migrants to the Korean society has been geographically differentiated. Due to the limits of spatial perspectives, existing studies on the adaptation of foreign migrants to the Korean society tend to ignore the geographical variations in the ways in, and the degrees at, which foreign migrants have been adapted into the Korean society. There are, however, significant regional variations in the living conditions, physical and cultural environments, and economic opportunities that are given to the foreign migrants in Korea, so that the adaptation of foreign migrants to the Korean society is regionally differentiated. In order to prove this, this paper explores whether and how the ways in which foreign professional migrants have adapted to the Korean society have been regionally differentiated on the basis of questionnaire surveys and statistical analyses.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• v.9 no.1
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• pp.524-527
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• 2005

A society has progressed rapidly toward the highly advanced digital information age. However, noise is generated by several causes, when signal is processed. Therefore, methods for eliminating those noises have researched. There were the existing FFT(fast fourier transform) and STFT(short time fourier transform) for removing noise but it's impossible to know information about time and time-frequency localization capabilities have conflictive relationship. Therefore, for overcoming these limits, wavelet-based denoising methods that are capable of multiresolution analysis are applied to the signal processing field. However, existing threshold- and correlation-based denoising methods consider only statistical characteristics for noise, accordingly a lot of noise is acceptable as an edge and are impossible to remove AWGN and impulse noise, at the same time. Hence, in this paper we proposed wavelet-based new denoising algorithm and compared existing methods with it.

• Journal of the Korean Society of Clothing and Textiles
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• v.40 no.6
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• pp.1034-1044
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• 2016

This study seeks a method to objectively evaluate sensibility based on Big Data in the field of design. In order to do so, this study examined the sensibility responses on design factors for the public through a network analysis of texts displayed in social media. 'Hanbok', a formal clothing that represents Korea, was selected as the subject for the research methodology. We then collected 47,677 keywords related to Hanbok from 12,000 posts on Naver blogs from January $1^{st}$ to December $31^{st}$ 2015 and that analyzed using social matrix (a Big Data analysis software) rather than using previous survey methods. We also derived 56 key-words related to design elements and sensibility responses of Hanbok. Centrality analysis and CONCOR analysis were conducted using Ucinet6. The visualization of the network text analysis allowed the categorization of the main design factors of Hanbok with evaluation terms that mean positive, negative, and neutral sensibility responses. We also derived key evaluation factors for Hanbok as fitting, rationality, trend, and uniqueness. The evaluation terms extracted based on natural language processing technologies of atypical data have validity as a scale for evaluation and are expected to be suitable for utilization in an index for sensibility evaluation that supplements the limits of previous surveys and statistical analysis methods. The network text analysis method used in this study provides new guidelines for the use of Big Data involving sensibility evaluation methods in the field of design.

• Restorative Dentistry and Endodontics
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• v.24 no.2
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• pp.356-363
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• 1999

The purpose of this study was to compare the apical sealing effect of Microseal obturation technique with lateral condensation technique in 26 recently extracted single rooted teeth. The root canals were instrumented using step-back technique and obturated with laterally condensed gutta-percha or Microseal. Teeth were suspended in methylene blue dye for 2 days and then longitudinary splited. The apical microleakage and the adaptability of gutta-percha to the root canal wall were examined under a stereomicroscope at ${\times}20$ magnification. The results were as follows: 1. The mean leakage was 1.38${\pm}$1.18 mm for laterally condensed gutta-percha group, and 0.71${\pm}$0.57 mm for Microseal gutta-percha group. But there was no statistical difference between two groups. 2. In Microseal gutta-percha group, they showed no gap between the master cone and Microseal gutta-percha, and showed homogeneous mass. 3. In contrast, laterally condensed gutta-percha group showed some gaps not only between gutta-percha cones, but also between gutta-percha cones and the canal walls, and the gaps were filled with some sealer. And also this group showed some amout of sealer on the root canal walls, Within the limits of the results of this experiment, Microseal gutta-percha obturation technique demonstrated relatively favorable apical sealing effect and shorter obturation time. Thus, it is thought that this obturation technique is a acceptable method for clinical use but further studies on this matter should be conducted.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2006.05a
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• pp.247-250
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• 2006

Maximizing the productivity in reactive ion etching, early detection of process equipment anomaly became crucial in current high volume semiconductor manufacturing environment. To address the importance of the process fault detection for productivity, support vector machines (SVMs) is employed to assist the decision to determine process faults in real-time. SVMs for eleven steps of etching runs are established with data acquired from baseline runs, and they are further verified with the data from controlled (acceptable) and perturbed (unacceptable) runs. Then, each SVM is further utilized for the fault detection purpose utilizing control limits which is well understood in statistical process control chart. Utilizing SVMs, fault detection of reactive ion etching process is demonstrated with zero false alarm rate of the controlled runs on a run to run basis.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.9
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• pp.4462-4466
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• 2013

In optical system, the signal and additive noise for statistical properties of a variety of ways to evaluate the performance of the system is essential for the optimization. In this paper, performance analysis of spectrum-sliced optical system in the optical pre-amplifier in the receiver the received signal by including the error limits for the bit that is, the bit error rate (BER: Bit Error Rate) required to maintain the average optical power represents the number of photons per bit is included in this paper to digital form, noticeable signal the receiver to calculate the sensitivity of the method for the calculation was performed. The general strength of the transmission of the modulated signal and digital signal transmission was required for the comparison of optical power. As shown in Figure 3, the general strength of the digital signal transmission system for transmitting a modulated signal compared with the case is improved by at least 10dB.