• Smart Structures and Systems
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• 제14권4호
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• pp.595-615
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• 2014

This study aims to investigate the relationship between structural damage and sensitivity indices using the Hilbert-Huang transform (HHT) method. Two damage detection indices are proposed: the ratio of bandwidth (RB), and the ratio of effective stiffness (RES). The nonlinear four bays multiple degree of freedom models with various predominant frequencies are constructed using the SAP2000 program. Adjusted PGA earthquake data (Japan 311, Chi-Chi 921) are used as the excitations. Next the damage detection indices obtained using the HHT and the fast Fourier transform (FFT) methods are evaluated based on the acceleration responses of the structures to earthquakes. Simulation results indicate that, the column of the 1 st floor is the first yielding position and the RB value is changed when the RES<90% in all cases. Moreover, the RB value of the 1 st floor changes more sensitive than those from the top floor. In addition, when the structural response is nonlinear (i.e., RES<100%), the RB and the RES curves indicate the incremental change in the HHT spectra. However, the same phenomenon can be found from FFT spectra only when the stiffness reduction is large enough. Therefore, the RB estimated from the smoothed HHT spectra is an effective and sensitive index for detecting structural damage.

• 동아시아식생활학회지
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• 제3권1호
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• pp.12-17
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• 1993

This book is named 'The Ryuk-Jab-Rok' because it was written in the last page of 1820's almanac. This book is written purely in Korean and has not been published yet. This book comprises twenty eight items, among which there are eight items of vegetable preserving method, ten items of Jook preparation methods(a kind of cereal soup), nine items of Pyun-Myun methods(a kind of rice cakes and noodles) and Yak-Bab(a kind of spiced rice). In vegetable preserving method, the eggplant, the cucumber and a songi mushroom were preserved with the drying method., A radish, a sorojangii, and the root of white cabbage were used with the cold temperature preservation. A garlic was dried after salting. The sprouts of DooRub, which were coming in the hot room, were used. In the Jook preparations, there were five animal materials which were lamb, chick, crudian, oyster and abalone. In nine Pyun-Myun methods, Jap-Gua-Sil was illegible because the letters were not clear. Among eight items, the stick rice was used in four cases, the regular rice in two cases. The ground pine nuts, honey and the Chinese date were used most ofter. And the sesame salt and the chestnut were next. The analysis of the terms I this book revealed that 26 items were used for cooking processes. And it also showed us that there were seven kind of cutting procedure and eight kinds of heating procedure. The shapes and size of foods were revealed at only three places in all items. The one-chi(chi ; abut three cm) and three-Ja(Ja ; about thirty cm) which the terms represent the length were revealed twice and once respectively in this book. In the taste description, 'the good', the most common word, was used in seven times, and which was the most frequently introduce case. The measuring unit is hard to revive since the measurements were taken by the container, which were Jong-Ja, Sabal and Tang-gii, then in use. Fifteen kinds of containers and cookers were used for preparing foods. And all of them are now I use.

• ETRI Journal
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• 제41권1호
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• pp.23-31
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• 2019

Since the late 20th century, there has been rapid development in the display industry. Only 30 years ago, we used big cathode ray tube displays with poor resolution, but now most people use televisions or smartphones with very high-quality displays. People now want images that are more realistic, beyond the two-dimensional images that exist on the flat screen, and digital holography-one of the next-generation displaysis expected to meet that need. The most important parameter that determines the performance of a digital hologram is the pixel pitch. The smaller the pixel pitch, the higher the level of hologram implementation possible. In this study, we fabricated the world-smallest $3-{\mu}m$-pixel-pitch holographic backplane based on the spatial light modulator technology. This panel could display images with a viewing angle of more than $10^{\circ}$. Furthermore, a comparative study was conducted on the fabrication processes and the corresponding holographic results from the large to the small pixel-pitch panels.

• 통합자연과학논문집
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• 제15권1호
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• pp.9-18
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• 2022

This research examines the power of bootstrap two-sample test, and compares it with the powers of two-sample t-test and Wilcoxon rank sum test, through simulation. For simulation work, a positively skewed and heavy tailed distribution was selected as a population distribution, the chi-square distributions with three degrees of freedom, χ²₃. For two independent samples, the fist sample was selected from χ²₃. The second sample was selected independently from the same χ²₃ as the first sample, and calculated d+ax for each sampled value x, a randomly selected value from χ²₃. The d in d+ax has from 0 to 5 by 0.5 interval, and the a has from 1.0 to 1.5 by 0.1 interval. The powers of three methods were evaluated for the sample sizes 10,20,30,40,50. The null hypothesis was the two population medians being equal for Bootstrap two-sample test and Wilcoxon rank sum test, and the two population means being equal for the two-sample t-test. The powers were obtained using r program language; wilcox.test() in r base package for Wilcoxon rank sum test, t.test() in r base package for the two-sample t-test, boot.two.bca() in r wBoot pacakge for the bootstrap two-sample test. Simulation results show that the power of Wilcoxon rank sum test is the best for all 330 (n,a,d) combinations and the power of two-sample t-test comes next, and the power of bootstrap two-sample comes last. As the results, it can be recommended to use the classic inference methods if there are widely accepted and used methods, in terms of time, costs, sometimes power.

• 보건의료산업학회지
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• 제7권3호
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• pp.95-109
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• 2013

The objective of this study is to assess the utilization and satisfactions about public health centers in Korea. For the analysis, the study utilize the nationwide data of 229,229 person on '2010 Community Health Survey' of Ministry of Health & Welfare. The statistical methodology used in the study is ${\chi}^2$, ANOVA, logistic regression model and multiple regression model. This study have four major findings. First, the significant affecting socio-demographic factors in utilizing public health center were gender, age, region, national basic living secured, married, income, education, job, state of health, chronic disease, unmet medical needs and utilization reason. Second, the most serviced category of health center user was vaccination both city and rural area and the next was certificate, primary care, health screening, other use, the mother and child in city area, primary care, health screening, certificate, home visiting health in rural area. Third, the significant affecting socio-demographic factors in satisfaction degree on health center service were age, region, national basic living secured, income, education, job, state of health, utilization degree and reason. Fourth, the most satisfied service of health service center was home visiting health in city area and mental health service in rural area and the next was nutritive control and the lowest satisfied service was user of certificate. The utilization and satisfaction on health center service were identified as different with residental area and user's characteristics. The politic effort are needed to support socially disadvantaged class and to narrow regional gap.

• 한국통신학회논문지
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• 제29권11B
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• pp.956-966
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• 2004

향후 NGN(Next Generation Network)은 패킷 기반의 QoS가 제공되는 네트웍으로 발전하고 있다. 본 논문에서는 MPLS 네트웍에서의 보다 효율적인 경로 선택에 관한 기법으로 Service interruption time을 줄이는 복구방법을 제안한다. 장애복구의 주요 성능 중의 하나인 복구자원사용의 효율성을 높이기 위해서 각 노드들 간의 state information을 fault detector 와 bandwidth broker가 서로 공유하여 장애 발생 시 복구를 위한 message transmission time을 줄였다. 또한 트래픽양의 변화에 따라 망 전체의 필요한 대역폭을 효과적으로 관리하고 변화시킴으로써 대역폭 사용의 효율성을 개선하였다. 그리고 우선순위 서비스를 제공할 수 있는 MPLS 망에서 우선순위에 따른 트래픽에 대해서도 전체 망에 도메인을 나눔으로써 우선순위가 높은 트래픽에 대한 종단간 복구방법에 대해 효율적인 자원 할당을 하며 낮은 우선순위의 트래픽에 대해서 장애가 발생한 도메인 내에서만 경로 복구를 하여 재설정을 위한 시간을 줄일 수 있고, 불필요한 메시지의 전달을 줄일 수 있다

• 대한치과의사협회지
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• 제56권5호
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• pp.254-262
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• 2018

Objectives: This study aimed to compare the postoperative pain and clinical performance after applying three different intracanal medicaments and root canal sealers. Materials and Methods: Sixty-five patients requiring root canal treatment due to symptomatic apical periodontitis were included in this study. After a glide path preparation by using PathFile, each canal was shaped with ProTaper Next file system. After the canal cleaning and shaping procedure, the canal was dried and each intracanal medicaments were adjusted (Calcipex II, TRC-paste, Metapaste). At the next visit, the patients were requested to answer the absence of the pain after the procedure. Once the patients showed no symptom, the canal was obturated with each corresponded root canal sealers (AH plus, Radic-sealer, ADseal). The patients were recalled after 1 week, 1, 3, and 6 months to check the postoperative pain or unexpected clinical signs. One-way ANOVA and Duncan's post hoc comparison, and Chi-square test were used for statistical analysis to evaluate any differences among tested materials. Results: The average number of visits for intracanal medication was 2.69, 2.65, and 2.61 for Calcipex II, TRC-paste, and Metapaste. There were no statistically differences in post-obturation pain among three groups obturated with different root canal sealers (P > 0.05). Conclusions: Under the limitations of this study, three tested intracanal medicaments and epoxy resin root canal sealers showed clinically acceptable similar results.

• 한국의상디자인학회지
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• 제14권4호
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• pp.89-98
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• 2012

The purpose of this study is to female child Han-bok reform design for body growth. Nowadays there is common the western style daily life and special day instead of traditional style Han-bok in Korea. So the decrease in the use of Han-bok have being appeared. Specially, Children's Han-bok undesirable clothes for economic, environment, and resources because of their rapid growth and changing trend. Therefor, they do away with used Han-bok without next buying of school age. Children's parents and children are decision together purchase of children's Han-bok on-line for pleasure and economic reasons on pre-school or 1st year student for their tradition-education class. After 2000year, children's Han-bok pup-up on e-market because of the fashion focus on tradition and Korean wave for parody of Korean drama. Flowing the Research of 2010 Size Korea, the elementary school age child height growth 6cm per year, the sleeve length are 3cm growth. But Chi-ma(a pice of Han-bok) from e-market, has only 5cm margin on shoulder and no margin on Jegori(a pice of Han-bok) shoulder and sleeve, reason of that the children can't wear next year. Therefor this study is development female child Han-bok reform design for body growth, for extend to wear Han-bok on school age children and flow tradition custom of Cho-sun Dynasty's clothing custom for boost tradition conscious and reduce of cloth waste for environment.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제16권1호
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• pp.153-172
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• 2022

In this study, the authors intend to analyze factors contributing to research performance using Backpropagation Neural Network and Support Vector Machine. The analyzing factors contributing to lecturer research performance start from defining the features. The next stage is to collect datasets based on defining features. Then transform the raw dataset into data ready to be processed. After the data is transformed, the next stage is the selection of features. Before the selection of features, the target feature is determined, namely research performance. The selection of features consists of Chi-Square selection (U), and Pearson correlation coefficient (CM). The selection of features produces eight factors contributing to lecturer research performance are Scientific Papers (U: 154.38, CM: 0.79), Number of Citation (U: 95.86, CM: 0.70), Conference (U: 68.67, CM: 0.57), Grade (U: 10.13, CM: 0.29), Grant (U: 35.40, CM: 0.36), IPR (U: 19.81, CM: 0.27), Qualification (U: 2.57, CM: 0.26), and Grant Awardee (U: 2.66, CM: 0.26). To analyze the factors, two data mining classifiers were involved, Backpropagation Neural Networks (BPNN) and Support Vector Machine (SVM). Evaluation of the data mining classifier with an accuracy score for BPNN of 95 percent, and SVM of 92 percent. The essence of this analysis is not to find the highest accuracy score, but rather whether the factors can pass the test phase with the expected results. The findings of this study reveal the factors that have a significant impact on research performance and vice versa.

• 유통과학연구
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• 제13권9호
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• pp.103-112
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• 2015

Purpose - This paper aims to provide a step-by-step approach to factor analytic procedures, such as principal component analysis (PCA) and exploratory factor analysis (EFA), and to offer a guideline for factor analysis. Authors have argued that the results of PCA and EFA are substantially similar. Additionally, they assert that PCA is a more appropriate technique for factor analysis because PCA produces easily interpreted results that are likely to be the basis of better decisions. For these reasons, many researchers have used PCA as a technique instead of EFA. However, these techniques are clearly different. PCA should be used for data reduction. On the other hand, EFA has been tailored to identify any underlying factor structure, a set of measured variables that cause the manifest variables to covary. Thus, it is needed for a guideline and for procedures to use in factor analysis. To date, however, these two techniques have been indiscriminately misused. Research design, data, and methodology - This research conducted a literature review. For this, we summarized the meaningful and consistent arguments and drew up guidelines and suggested procedures for rigorous EFA. Results - PCA can be used instead of common factor analysis when all measured variables have high communality. However, common factor analysis is recommended for EFA. First, researchers should evaluate the sample size and check for sampling adequacy before conducting factor analysis. If these conditions are not satisfied, then the next steps cannot be followed. Sample size must be at least 100 with communality above 0.5 and a minimum subject to item ratio of at least 5:1, with a minimum of five items in EFA. Next, Bartlett's sphericity test and the Kaiser-Mayer-Olkin (KMO) measure should be assessed for sampling adequacy. The chi-square value for Bartlett's test should be significant. In addition, a KMO of more than 0.8 is recommended. The next step is to conduct a factor analysis. The analysis is composed of three stages. The first stage determines a rotation technique. Generally, ML or PAF will suggest to researchers the best results. Selection of one of the two techniques heavily hinges on data normality. ML requires normally distributed data; on the other hand, PAF does not. The second step is associated with determining the number of factors to retain in the EFA. The best way to determine the number of factors to retain is to apply three methods including eigenvalues greater than 1.0, the scree plot test, and the variance extracted. The last step is to select one of two rotation methods: orthogonal or oblique. If the research suggests some variables that are correlated to each other, then the oblique method should be selected for factor rotation because the method assumes all factors are correlated in the research. If not, the orthogonal method is possible for factor rotation. Conclusions - Recommendations are offered for the best factor analytic practice for empirical research.