• 한국산업융합학회 논문집
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• 제26권4_2호
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• pp.629-637
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• 2023

This study aimed to evaluate the effect of post-curing equipment and time on the flexural strength of 3D printing resins produced by a liquid crystal display(LCD) printer. The three 3D printing resins(DENTCA Denture Teeth, DT; C&B 5.0 hybrid, CH; C&B Permanent A2, CP) were divided into four groups according to post-curing time(10 min and 30 min) and equipment with or without vacuum treatment. For the three-point flexural strength test and biaxial strength test were prepared by method according to ISO 10477, ISO 6872, respectively. Flexural strength was measured with universal testing machine. Comparison between post-curing time of each post-curing equipment was analyzed by independent sample t-test and Mann-Whitney U test(α=.05), and comparison between groups according to each 3D printing resin was performed by Kruskal-Wallis test and post-hoc by Bonferroni-Dunn test(α=.05). The flexural strength of the resin post-curing under vacuum was higher than that of the resin post-curing in air. In the comparison according to the post-curing time, in the case of the post-curing equipment without vacuum, the 30 minute curing time showed significantly higher flexural strength than the 10 minute curing time, except for the biaxial flexural strength of CH(P<.05). In the post-curing equipment with vacuum, the three-point flexural strength of all 3D printing resins(DT, CH, and CP) showed a higher value at 30 minute curing time than at 10 minute curing time.

• 대한물리치료과학회지
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• 제27권3호
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• pp.45-55
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• 2020

Background: The purpose of this study was to investigate the effects of WBC (whole-body cryotherapy)on the MVIC (maximal voluntary isometric contraction)and active ROM (range of motion) recovery of after EIMD (exercise-induced muscle injury). Design: Randomized Controlled Trial. Methods: Thirty subjects who are student in their 20s at a university participated in this study, these subjects were assigned into three groups, a control group (n=10), experiment group I(n=10), and experiment group II (n=10). The subjects in the experimental group II were intervened by WBC (-130℃, 3 minutes) before induced EIMD, the experimental group were intervened by WBC (-130℃, 3 minutes) after induced EIMD, and the control group weren't by any intervened after induced EIMD. Results: First, In the comparison of the MVIC, there were significant variations with the lapse the time in three groups (p<.001) and there was a significant interaction of time and group (p<.001). In the among group comparison, the MVIC of experimental group II was significantly larger than those of other groups (p<.001). Second, In the comparison of the active extension angle, there were significant variations with the lapse the time in three groups (p<.001) and there was a significant interaction of time and group (p<.001). In the among group comparison, the active extension angle of experimental group II was significantly smaller than those of other groups (p<.001). Third, In the comparison of the active flexion angle, there were significant variations with the lapse the time in three groups (p<.01) and there was a significant interaction of time and group (p<.001). In the among group comparison, the active flexion angle of experimental group II was significantly larger than those of other groups (p<.05). Conclusion: The above results revealed that the WBC intervention after an exercise had a positive effect of muscle function after EIMD. Therefore we can consider the WBC as a considerable intervention method to prevent or reduce an exercise injury.

• 한국가정과학회지
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• 제10권1호
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• pp.19-25
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• 2007

The study is attempted to help double-income families use resources efficiently and rationally by analyzing The Time Use each of working women and housewives having preschool children based on the data of The Time Use survey carried out in 2004 and promote understandings on their quality of life, lifestyle and family welfare. To this end, the study analyzes the actual The Time Use of double-income families haying preschool children. The findings of the study are as follows: First, according to the comparison of The Time Use between double-income families and single-income families in 1999 and 2004, there is no significant difference in husbands' participation time in family management or family care between 1999 and 2004. Second, according to the comparison of The Time Use between double-income families and single-income families depending on the presence or non-presence of preschool children, families haying preschool children spent much more hours in family care than families without preschool children. Third, according to the comparison of the weekend schedule between double-income families and single-income families, it is found that working women work much more than housewives not only on weekdays but also on weekends and in particular, it is found that working women having preschool children work 2 hours longer than housewives.

• International Journal of Internet, Broadcasting and Communication
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• 제12권4호
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• pp.61-70
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• 2020

As mobile device usage time increases thanks to the development of information and communication alongside the increase in the spread of smartphones, mobile shopping has become a common trend. While mobile shopping has the advantage of saving both time and money, it may also result in dissatisfaction with product differences after purchase. For online clothing shopping malls, in particular, if the size does not match after purchase, it is difficult for customers to return or exchange the goods. To address this problem, some mobile apparel shipping malls offer a virtual fitting service and a size comparison function; however, the number of such malls remains low. In this paper, a usability evaluation was performed on a mobile apparel shopping mall that provides a size comparison function. The three apps selected for evaluation have different size input methods, and a slightly different method of providing results after comparing the user's dimensions with the dimensions of the clothes to be purchased. In this paper, the evaluators were asked to select clothes at the shopping mall and perform the task of deciding the size of the clothes to be purchased through their own measurements and comparison while also evaluating the effectiveness, meaning, and satisfaction of the apps. Based on the analysis of the results, this paper aims to produce an improvement plan and help design the size comparison UI (User Interface) in the future.

• 아동학회지
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• 제26권5호
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• pp.367-377
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• 2005

Semi-structured in-depth interview method were used to test psycho-social comparison among first time offenders and repeated offenders. Data were analyzed by t-test and chi-square. Differences between first time offenders and repeated offenders were that there were more male offenders than female offenders, and violent and theft offenders were more than sex offenders fraud and traffic offenders; early starters were more repeated offenders than late starters; there were some variables such as runway of home, parents' caring attitude, school drop out and maladjustment affecting in repeated offenses; developmental environment of repeated offenders were more negative than first time offenders. Therefore, intervention and prevention program development of good parenting and schooling and forensic counseling focused on optimal developmental environment is needed.

• Journal of the Korean Data and Information Science Society
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• 제18권1호
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• pp.17-29
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• 2007

The major purpose of this article is the comparison of estimation method with Newton-Raphson, Kalman-filter, and prediction method with Kalman prediction. Conditional expectation in space time bilinear(STBL) model, which is a very powerful and parsimonious nonlinear time-series model for the space time series data can be viewed as a set of time series collected simultaneously at a number of spatial locations and time points, and which have appeared in a important applications areas: geography, geology, natural resources, ecology, epidemiology, etc.

• Structural Monitoring and Maintenance
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• 제4권4호
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• pp.365-379
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• 2017

This paper presents a comparison of the black-box and the physics based derived gray-box models for subspace identification for structures subjected to support-excitation. The study compares the damage detection capabilities of both these methods for linear time invariant (LTI) systems as well as linear time-varying (LTV) systems by extending the gray-box model for time-varying systems using short-time windows. The numerically simulated IASC-ASCE Phase-I benchmark building has been used to compare the two methods for different damage scenarios. The efficacy of the two methods for the identification of stiffness parameters has been studied in the presence of different levels of sensor noise to simulate on-field conditions. The proposed extension of the gray-box model for LTV systems has been shown to outperform the black-box model in capturing the variation in stiffness parameters for the benchmark building.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2007년도 학술발표회 논문집
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• pp.1798-1802
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• 2007

The practice of business estimate flood discharge by rainfall-flow relation that is easy collection of observation data. The important factor is rainfall, coefficient of runoff, and drainage area for analysis of runoff-flow relation.The practice of business usually use probability rainfall that use a weighted average value after each observation post estimate probability of non-same time. It has more error than same time probability rainfall, and it can excess of estimation because it can't consider space distribution of rainfall.The study of result showed similar aspect with existing ARF but width of coefficient become smaller. And the comparison of peak flow did not different what used by ARF and same time probability rainfall(A group). But non-same time probability rainfall is bigger 25% more than another(B group). Between A group and B group of the difference increased with the lapse of time.

• 산업기술연구
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• 제27권A호
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• pp.95-102
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• 2007

The practice of business estimate flood discharge by rainfall-flow relation that is easy collection of observation data. The important factor is rainfall, coefficient of runoff, and drainage area for analysis of runoff-flow relation. The practice of business usually use probability rainfall that use a weighted average value after each observation post estimate probability of non-same time. It has more error than same time probability rainfall, and it can excess of estimation because it can't consider space distribution of rainfall. The study of result showed similar aspect with existing ARF but width of coefficient become smaller. And the comparison of peak flow did not different what used by ARF and same time probability rainfall(A group). But non-same time probability rainfall is bigger 25% more than another(B group). Between A group and B group of the difference increased with the lapse of time.

• Journal of Microbiology and Biotechnology
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• 제21권1호
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• pp.100-108
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• 2011

A method for the rapid detection and quantification of Newcastle disease virus (NDV) produced in an animal cell culture-based production system was developed to enhance the speed of the NDV vaccine manufacturing process. A SYBR Green I-based real-time RT-PCR was designed with a conventional, inexpensive RT-PCR kit targeting the F gene of the NDV LaSota strain. The method developed in this study was validated for specificity, accuracy, precision, linearity, limit of detection (LOD), limit of quantification (LOQ), and robustness. The validation results satisfied the predetermined acceptance criteria. The validated method was used to quantify virus samples produced in an animal cell culture-based production system. The method was able to quantify the NDV samples from mid- or late-production phases, but not effective on samples from the early-production phase. For comparison with other quantifiable methods, immunoblotting, plaque assay, and tissue culture infectious dose 50 ($TCID_{50}$) assay were also performed with the NDV samples. The results demonstrated that the real-time RT-PCR method is suitable for the rapid quantification of virus particles produced in an animal cell-culture-based production system irrespective of viral infectivity.