• KSII Transactions on Internet and Information Systems (TIIS)
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• v.8 no.4
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• pp.1307-1323
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• 2014

With the exhaustion of global IPv4 addresses, IPv6 technologies have attracted increasing attentions, and have been deployed widely. Meanwhile, new applications running over IPv6 networks will change the traditional traffic characteristics obtained from IPv4 networks. Traditional models obtained from IPv4 cannot be used for IPv6 network monitoring directly and there is a need to investigate those changes. In this paper, we explore the flow features of IPv6 traffic and compare its difference with that of IPv4 traffic from flow level. Firstly, we analyze the differences of the general flow statistical characteristics and users' behavior between IPv4 and IPv6 networks. We find that there are more elephant flows in IPv6, which is critical for traffic engineering. Secondly, we find that there exist many one-way flows both in the IPv4 and IPv6 traffic, which are important information sources for abnormal behavior detection. Finally, in light of the challenges of analyzing massive data of large-scale network monitoring, we propose a group flow model which can greatly reduce the number of flows while capturing the primary traffic features, and perform a comparative measurement analysis of group users' behavior dynamic characteristics. We find there are less sharp changes caused by abnormity compared with IPv4, which shows there are less large-scale malicious activities in IPv6 currently. All the evaluation experiments are carried out based on the traffic traces collected from the Northwest Regional Center of CERNET (China Education and Research Network), and the results reveal the detailed flow characteristics of IPv6, which are useful for traffic management and anomaly detection in IPv6.

• The Journal of Advanced Prosthodontics
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• v.6 no.1
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• pp.39-45
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• 2014

PURPOSE. The aim of the present study was to evaluate the accuracy of three techniques for correction of cast implant bars. MATERIALS AND METHODS. Thirty cast implant bars were fabricated on a metal master model. All cast implant bars were sectioned at 5 mm from the left gold cylinder using a disk of 0.3 mm thickness, and then each group of ten specimens was corrected by gas-air torch soldering, laser welding, and additional casting technique. Three dimensional evaluation including horizontal, vertical, and twisting measurements was based on measurement and comparison of (1) gap distances of the right abutment replica-gold cylinder interface at buccal, distal, lingual side, (2) changes of bar length, and (3) axis angle changes of the right gold cylinders at the step of the post-correction measurements on the three groups with a contact and non-contact coordinate measuring machine. One-way analysis of variance (ANOVA) and paired t-test were performed at the significance level of 5%. RESULTS. Gap distances of the cast implant bars after correction procedure showed no statistically significant difference among groups. Changes in bar length between pre-casting and post-correction measurement were statistically significance among groups. Axis angle changes of the right gold cylinders were not statistically significance among groups. CONCLUSION. There was no statistical significance among three techniques in horizontal, vertical and axial errors. But, gas-air torch soldering technique showed the most consistent and accurate trend in the correction of implant bar error. However, Laser welding technique, showed a large mean and standard deviation in vertical and twisting measurement and might be technique-sensitive method.

• Journal of the Korean Geophysical Society
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• v.10 no.1
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• pp.27-35
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• 2007

There are many risks in constructing tunnel-structure. To prevent these risks from occurring and secure safety, the precise and rapid survey of inside displacement of the tunnel is required. But nowadays the measurement of the crown settlement, convergency, and surface settlement depends on general kinds of method which use total station or level. In the way to provide data about maintaining structure according to recent improvement and progress of measuring technology, 3D laser scanning is used. It solves the problem of reliability in measuring displacement of existing structure, provides material that enables to estimate shape change of structure visually, and makes it possible to deliberate speedy countermeasure. By this three dimensioning it is possible to make efficient use of structure maintenance and field measurement.

• Journal of The Korean Society of Integrative Medicine
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• v.11 no.2
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• pp.129-140
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• 2023

Purpose : This study was conducted to investigate and analyze the physical health of older Koreans with sarcopenia and locomotive syndrome and identify the related factors. Methods : In this study, the sarcopenia and locomotive syndrome evaluations were applied to 210 elderly people, and the sarcopenia group was 36, the locomotive syndrome group was 164, and the normal group was 10. After group selection, a physical health status survey was conducted. The physical health status was assessed via body composition analysis, physical characteristics survey including measurement of waist and calf circumference, investigation of diseases currently being diagnosed by a doctor, and frailty measurements. The collected data were statistically analyzed using one-way ANOVA, the Kruskal-Wallis test, and the Chi-square test. Results : There were significant differences between groups in all elements of physical characteristics including body mass index, waist circumference, and calf circumference. Among them, a consistent result was found that the normal group had the largest amount of muscle mass and the sarcopenia group had the least amount of muscle mass in the factors related to muscle mass. However, the factors relating to fat mass and obesity also showed significant differences between the groups, but the results were not consistent. Considering the group differences in current diseases, a significant difference was only detected for osteoporosis among 12 diseases. Moreover, those in the sarcopenia group had the highest rate of osteoporosis. And there was no significant difference between the groups in the total score of the frailty measurement, but there was a significant difference between the groups in the frailty measurement levels. Conclusion : This study on physical health status confirmed that muscle mass-related factors, osteoporosis, and frailty levels were significantly related to sarcopenia and locomotive syndrome.

• Journal of Korean Public Health Nursing
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• v.23 no.2
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• pp.273-284
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• 2009

Purpose: The study examined obesity conditions and related factors in middle aged Korean women who had been diagnosed as obese based body mass index (BMI) or waist circumference (WC) measurement. Presently, BMI alone, WC alone, or BMI + WC were used as obesity measures. Methods: Subjects were 488 women 40~64 years of age living in one city, Korea. Structured questionnaires concerning general characteristics, health behavior practices, and chronic disease history were completed by each subject. Results: The proportions of obesity were 42.4% by BMI, 39.3% by WC, and 51.3% by the combination of both measurements. Chi-square test revealed significant associations of obesity with age, education level, menopausal status, frequency of excessive eating, and history of diabetes mellitus or hypertension. These associations were similar for the three measurement schemes. There was significant positive relationship between BMI and WC, whereas the relationship between BMI and WHR (waist-hip ratio) was not significant. Conclusions: The combination of BMI and WC measurement may be a valid way to evaluate the obesity status in middle-aged women. Developing an obesity management program that includes control of excessive eating, and consideration of menopausal status and history of chronic diseases would be prudent.

• The Journal of the Acoustical Society of Korea
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• v.42 no.6
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• pp.511-518
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• 2023

Accurate ranging is one of the key factors in the test and evaluation process of underwater vehicles. In particular, when estimating range using Time of Arrival (ToA) values, signals such as Linear Frequency Modulation (LFM), a chirp signal, are highly applicable due to their correlated nature. However, in a Doppler shift environment with mobility, measurement errors may occur due to the range-Doppler coupling effect. In this paper, we propose a signal that compensates for the distance-Doppler coupling effect to reduce the measurement error of the arrival time value. The proposed signal is constructed by superimposing two types of LFM signals, and the range-Doppler coupling effect can be minimized. Through simulations, it is confirmed that the proposed signal is a way to compensate for the distance-Doppler coupling effect in the distance estimation of underwater mobile bodies, reducing the measurement error of the arrival time value.

• The Journal of the Convergence on Culture Technology
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• v.10 no.2
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• pp.439-446
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• 2024

The purpose of this study was to investigate relationship among sexual knowledge, sexual attitudes, and reproductive health promoting behaviors of nursing college students. The research tools utilized were sexual knowledge measurement tool by Jeon(2004), sexual attitudes measurement tool by Ho(2009), and reproductive health promoting behaviors measurement tool by Jo(2014). A total of 300 nursing college students were surveyed, and 229 responses were analyzed. Data analysis was performed using descriptive statistics, t-test, ANOVA, Scheffe's post hoc test and pearson's correlation coefficients with IBM SPSS Statistics 21.0. Female students exhibited higher sexual knowledge, and it was evident that reproductive health promoting behavior education is appropriate during lower academic years. Additionally, the indication that higher sexual knowledge corresponds to higher reproductive health promoting behaviors suggests the ongoing necessity for sexual education to enhance reproductive health promoting behaviors. Therefore, this study could serve as foundational data for developing educational materials on reproductive health promoting behaviors for counseling and education aimed at improving nursing college students' reproductive health.

• The Journal of Korean Academy of Prosthodontics
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• v.59 no.3
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• pp.261-270
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• 2021

Purpose. The aim of this study was (1) to compare the reverse engineering technique with other existing measurement methods and (2) to analyze the effect of implant angulations and impression coping types on implant impression accuracy with reverse engineering technique. Materials and methods. Three different master models were fabricated and the distance between the two implant center points in parallel master model was measured with different three methods; digital caliper measurement (Group DC), optical measuring (Group OM), and reverse engineering technique (Group RE). The 90 experimental models were fabricated with three types of impression copings for the three different implant angulation and the angular and distance error rate were calculated. One-way ANOVA was used for comparison among the evaluation methods (P < .05). The error rates of experimental groups were analyzed by two-way ANOVA (P < .05). Results. While there was significant difference between Group DC and RE (P < .05), Group OM had no significant difference compared with other groups (P > .05). The standard deviations in reverse engineering were much lower than those of digital caliper and optical measurement. Hybrid groups had no significant difference from the pick-up groups in distance error rates (P > .05). Conclusion. The reverse engineering technique demonstrated its potential as an evaluation technique of 3D accuracy of impression techniques.

• The Journal of the Convergence on Culture Technology
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• v.10 no.2
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• pp.365-371
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• 2024

The purpose of this study was to investigate the effect of leisure satisfaction according to calligraphy activities of the elderly on self-efficacy and psychological well-being. In order to conduct this study, the researchers surveyed 306 elderly people aged 65-76 or older from late November to early December 2023 in Anyang City and Xinxiang City, Henan Province, China. In order to verify the research hypothesis, the researchers performed frequency analysis, descriptive statistics analysis, and Pearson correlation analysis using IBM SPSS Statistics 25, and then performed independent sample T-test and one-way analysis of variance (One-Way ANOVA). To verify the hypothesis through the measurement concept, related verification was conducted for Hayes PROCESS macro and Bootstrap. As a result of the study, first, there is a gender difference in leisure satisfaction, leisure satisfaction, self-efficacy, and psychological well-being, and leisure satisfaction and psychological well-being differ significantly according to age. Second, it was found that leisure satisfaction had a positive effect on self-efficacy. Third, it was found that leisure satisfaction had a positive effect on psychological well-being. Fourth, leisure satisfaction was found to have a positive effect on psychological well-being. Therefore, in order to increase the leisure satisfaction and psychological well-being of the elderly, it is necessary to carefully develop a calligraphy activity system to increase self-efficacy.

• The Journal of Korean Academy of Prosthodontics
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• v.59 no.1
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• pp.11-17
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• 2021

Purpose: This study was to find out whether the rendering screen difference affect to measuring distance in a CAD program according to three types of CAD programs. Materials and methods: The model presented in ISO 12836 for dental scanner evaluation was reduced by 70%. This model was repeatedly scanned 15 times using Trios II (3Shape, Denmark). Using the output STL file, 3Shape CAD, inLab 15, and ExoCAD programs were used to measure the horizontal distance (H) and vertical distance (V) between adjacent point angle, and for each experiment, three groups were set according to the CAD program type. Statistical analysis was performed using One-way ANOVA test and post hoc was performed using Dunnett T3 test. Results: In the horizontal and vertical distance measurement, there was no difference in the average of the measured values between the three groups according to the CAD program (P>.05). Conclusion: There were no effect of the difference in the rendering screen in the horizontal and vertical linear distance measurements of the inlay model on the dental CAD program.