• Restorative Dentistry and Endodontics
• /
• 제48권2호
• /
• pp.16.1-16.11
• /
• 2023

Objectives: The aim of this study was to evaluate the influence of peak kilovoltage (kVp) and a metal artifact reduction (MAR) tool on image quality and the diagnosis of vertical root fracture (VRF) in cone-beam computed tomography (CBCT). Materials and Methods: Twenty single-rooted human teeth filled with an intracanal metal post were divided into 2 groups: control (n = 10) and VRF (n = 10). Each tooth was placed into the socket of a dry mandible, and CBCT scans were acquired using a Picasso Trio varying the kVp (70, 80, 90, or 99), and the use of MAR (with or without). The examinations were assessed by 5 examiners for the diagnosis of VRF using a 5-point scale. A subjective evaluation of the expression of artifacts was done by comparing random axial images of the studied protocols. The results of the diagnoses were analyzed using 2-way analysis of variance and the Tukey post hoc test, the subjective evaluations were compared using the Friedman test, and intra-examiner reproducibility was evaluated using the weighted kappa test (α = 5%). Results: The kVp and MAR did not influence the diagnosis of VRF (p > 0.05). According to the subjective classification, the 99 kVp protocol with MAR demonstrated the least expression of artifacts, while the 70 kVp protocol without MAR led to the most artifacts. Conclusions: Protocols with higher kVp combined with MAR improved the image quality of CBCT examinations. However, those factors did not lead to an improvement in the diagnosis of VRF.

• 대한치과교정학회지
• /
• 제52권2호
• /
• pp.123-130
• /
• 2022

Objective: To evaluate if a remote digital monitoring system added at the end of orthodontic treatment could positively influence the retention phase by reducing the occurrence of misfit of removable appliances, number of emergency appointments (EA), and orthodontic relapse. Methods: Twenty-seven patients who completed active orthodontic treatment were divided into the study and control groups. In addition to the standard chairside follow-up appointments at month 1 (T1), month 3 (T2), month 6 (T3), the study group patients were monitored using Dental Monitoring^® with monthly intra-oral scans. Occurrence of misfit of removable retainers, number of EAs, and intercanine width change were recorded for both groups. Differences in EAs and retainer fit were assessed using the chi-square test. Intra-group and inter-group differences in the intercanine width were assessed with Friedman test and Mann-Whitney U test, respectively (α = 0.05). Results: The study group showed a significantly lower occurrence of misfit of removable retainers (p = 0.027) compared to the control group. No significant inter- and intra-group difference was found in the EAs and intercanine width change at each time-point. Conclusions: Integrating remote monitoring systems, such as Dental Monitoring^®, to the retention phase of the orthodontic treatment may lower the occurrence of misfit of removable retainers. However, a small sample size and a short observation period limit the strength of this evidence. These preliminary results tentatively suggest that remote monitoring technologies may be beneficial, especially during the COVID-19 pandemic, when the regularity of in-office visits might be disrupted.

• Korean Journal of Radiology
• /
• 제23권7호
• /
• pp.752-762
• /
• 2022

Objective: To compare a deep learning-based reconstruction (DLR) algorithm for pediatric abdominopelvic computed tomography (CT) with filtered back projection (FBP) and iterative reconstruction (IR) algorithms. Materials and Methods: Post-contrast abdominopelvic CT scans obtained from 120 pediatric patients (mean age ± standard deviation, 8.7 ± 5.2 years; 60 males) between May 2020 and October 2020 were evaluated in this retrospective study. Images were reconstructed using FBP, a hybrid IR algorithm (ASiR-V) with blending factors of 50% and 100% (AV50 and AV100, respectively), and a DLR algorithm (TrueFidelity) with three strength levels (low, medium, and high). Noise power spectrum (NPS) and edge rise distance (ERD) were used to evaluate noise characteristics and spatial resolution, respectively. Image noise, edge definition, overall image quality, lesion detectability and conspicuity, and artifacts were qualitatively scored by two pediatric radiologists, and the scores of the two reviewers were averaged. A repeated-measures analysis of variance followed by the Bonferroni post-hoc test was used to compare NPS and ERD among the six reconstruction methods. The Friedman rank sum test followed by the Nemenyi-Wilcoxon-Wilcox all-pairs test was used to compare the results of the qualitative visual analysis among the six reconstruction methods. Results: The NPS noise magnitude of AV100 was significantly lower than that of the DLR, whereas the NPS peak of AV100 was significantly higher than that of the high- and medium-strength DLR (p < 0.001). The NPS average spatial frequencies were higher for DLR than for ASiR-V (p < 0.001). ERD was shorter with DLR than with ASiR-V and FBP (p < 0.001). Qualitative visual analysis revealed better overall image quality with high-strength DLR than with ASiR-V (p < 0.001). Conclusion: For pediatric abdominopelvic CT, the DLR algorithm may provide improved noise characteristics and better spatial resolution than the hybrid IR algorithm.

• The Journal of Asian Finance, Economics and Business
• /
• 제6권4호
• /
• pp.139-145
• /
• 2019

This study examines the dynamic linkages between food price inflation and its volatility in the context of Sri Lanka. The empirical evidence derived from the monthly data for the period from 2003M1 to 2017M12 for Sri Lanka. The relationship between inflation rate and inflation volatility has attracted more attention by theoretical and empirical macroeconomists. Empirical studies on the relationship between food inflation and food inflation variability is scarce in the literature. Food price inflation is defined as log difference of food price series. The volatility of a food price inflation is measured by conditional variance generated by the FIGARCH model. Preliminary analysis showed that food inflation is stationary series. Granger causality test reveals that food inflation seems to exert positive impact on inflation variability. We find no evidence for inflation uncertainty affecting food inflation rates. Hence, the findings of the study supports the Friedman-Ball hypothesis in both cases of consumer food price inflation and wholesale food price inflation. This implies that past information on food inflation can help improve the one-step-ahead prediction of food inflation variability but not vice versa. Our results have some important policy implications for the design of monetary policy, food policy thereby promoting macroeconomic stability.

• 한국식품조리과학회지
• /
• 제19권5호
• /
• pp.581-590
• /
• 2003

The purpose of this study was to identify the combinations of factors combinations conferring the highest utility of family restaurants to university students, and establish the relative importance of these factors in terms of their contribution to total utility. 196 of 200 questionnaires were utilized for the analysis. (Eds note: to whom were the questionnaires administered) Frequencies, crosstabs, and the conjoint, max. utility, BTL and Logit models, K-means cluster and one-way ANOVA analysesis, and the Friedman test were the statistical methods used for this study. The findings from this study were as follows: 1) the Pearson's R and Kendall's tau statistics (Eds note: these were not mentioned earlier) show that the model (Eds note: which model is this) fits the data well. 2) it was found that of all the respondents, especially the first and third clusters, regarded both the type of food and the price as very important factors. 3) it was found that all the respondents, especially the third cluster, most preferred a family restaurant (design and simulation) that provided less than 6 fusion and traditional foods. The first cluster most preferred family restaurant (design) that provided over 10 traditional and less than 6 ethnic foods. The second cluster most preferred a family restaurant (design and simulation) that provided over 10 traditional foods. 4) the results of the study have provided some insights into the effective types of family restaurant designs that can be successfully developed by those who manage menu variety, quality and type of food, price, and quality of service to university students dining at family restaurants.

• Macromolecular Research
• /
• 제17권3호
• /
• pp.149-155
• /
• 2009

The thermal decomposition behavior and degradation characteristics off our different thermotropic liquid crystalline polymers (TLCPs) were studied. The thermal decomposition behavior was determined by means of thermogravimetric analysis (TGA) at different heating rates in nitrogen and air. The order of the thermal stability was as follows: multi-aromatic polyester > hydroxybenzoic acid (HBA)/hydroxynaphthoic acid (HNA) copolyester > HNA/hydroxyl acetaniline (HAA)/terephthalic acid (TA) copolyester > HBA/Poly(ethylene terephthalate) (PET) copolyester. The activation energies of the thermal degradation were calculated by four multiple heating rate methods: Flynn-Wall, Friedman, Kissinger, and Kim-Park. The Flynn-Wall and Kim-Park methods were the most suitable methods to calculate the activation energy. Samples were exposed to an accelerated degradation test (ADT), under fixed conditions of heat ($63{\pm}3^{\circ}C$), humidity ($30{\pm}4%$) and Xenon arc radiation ($1.10\;W/m^2$), and the changes in surface morphology and color difference with time were determined. The TLCPs decomposed, discolored and cracked upon exposure to ultraviolet radiation.

• 한국의류학회지
• /
• 제48권3호
• /
• pp.467-484
• /
• 2024

This study aimed to enhance the design of cropped t-shirts to improve fit satisfaction among women in their 20s by tailoring the t-shirts to diverse body types. Body types were categorized using Size Korea's 8th Human Body Measurement Data, and statistical analysis was conducted based on the Statistical Package for the Social Sciences (version 26.0). This study also reviewed the literature on t-shirts and fit, the application of pattern and design improvements for different body types, verifying fit and size for each body type, and applying virtual fit effects using geometric forms. Frequency analysis and non-parametric verification were conducted using the Friedman test. The results showed that t-shirts with a horizontal rectangular shape was an effective design and that t-shirts with an inverted triangular structure also had a positive effect. In contrast, square t-shirts exhibited minimal effectiveness. These findings are expected to contribute to the consideration of customized shapes according to body type in t-shirt design. Research on customized virtual cropped t-shirts reflecting various body types can expand fit satisfaction studies, particularly amid the increasing trend of online shopping.

• 한국융합학회논문지
• /
• 제11권5호
• /
• pp.353-361
• /
• 2020

본 연구는 신종감염병 대응 전담요원의 개인보호구 착탈의 융합 교육 효과를 확인하고자 시도되었다. Level D 개인보호구 착용 기준에 적합한 28명의 비의료인 신종감염병 대응 전담요원을 대상으로 2018년 3차에 걸쳐 교육 후 개인보호구 착탈의 점수를 수집하였으며 프리드만 검정(Friedman)과 윌콕슨 부호순위 검정(Wilcoxon's Signed-Ranks Test)으로 분석하였다. 연구결과, 교육횟수에 따른 분석에서 착의점수는 유의하게 상승하였고 탈의 점수는 유의한 차이를 보였다. 교육차수별 분석에서는 착의 점수는 1차보다 3차에서 유의하게 상승하였으며 탈의 점수는 1차보다 3차에서 점수가 상승하였으나 유의 하지 않았다. 본 연구의 대상자들은 비의료인이기 때문에 지식이 부족하지만 감염병에 접촉할 확률이 크기 때문에 교육이 필요한 점에서 의미가 크며 본 연구결과를 통하여 개인보호구 탈의 교육의 효과가 상대적으로 낮아 교육회수의 증가 혹은 주기적인 교육의 필요성이 중요하다고 파악되었다.

• 재활복지
• /
• 제21권4호
• /
• pp.195-208
• /
• 2017

본 연구는 자폐성 장애인들의 수면 문제와 수면 패턴에 대한 선행연구를 기반으로 수면에 영향을 미칠 수 있으며, 지적장애인 거주시설에서 치료적 접근으로 적용 가능한 재활승마 프로그램을 규칙적으로 제공하여 대상자들의 수면에 미치는 영향을 연구하고자 하였으며, 자폐성 장애인들의 취침시간, 기상시간, 총 수면시간, 수면 중 깨는 빈도를 분석하여 기초자료로 제공하고자 한다. 본 연구의 연구대상은 경기도 Y시 지적장애인 거주시설에서 거주하고 있는 자폐성 장애인 10명이며, 2015년 03월 01일부터, 05월 31일까지 총 12주간 재활승마 프로그램에 참여하였다. 재활승마 프로그램 참여에 따른 수면에 미치는 영향을 조사하기 위하여 수면 평가지를 통해 취침시간, 기상시간, 총 수면시간, 수면 중 깨는 빈도를 조사하였으며, 기술통계, 프리드만 검정(Friedman)을 실시하여 변화를 분석하였다. 분석결과 통계적으로 유의미하게 취침시간이 빨라졌으며, 총 수면시간이 증가하였고, 수면 중 깨는 빈도가 감소하여 재활승마 프로그램이 대상자들의 수면에 긍정적인 영향을 미친다고 나타났다. 재활승마 프로그램 적용이 참여 대상자들의 수면에 긍정적인 요인으로 작용할 수 있어 시설에 거주하고 있는 자폐성 장애인들에게 시설 내 프로그램으로 활용될 수 있을 것이다.

• 대한지역사회작업치료학회지
• /
• 제6권2호
• /
• pp.51-59
• /
• 2016

목적 : 본 연구에서는 규칙적인 재활체육 프로그램 참여에 따른 시설 거주 지적장애인들의 여가시간 사용과 여가활동 수행에 미치는 영향을 규명하여 시설 거주 지적장애인들의 여가시간 사용과 여가활동 수행에 대한 기초자료를 제공하는 데 그 목적이 있다. 연구방법 : 연구대상은 경기도 용인시 지적장애인 거주시설에서 거주하는 지적장애인 8명을 대상으로 하였으며, 2015년 09월 01일부터 11월 30일 까지 총 12주간 재활체육 프로그램을 실시하였다. 재활체육 프로그램으로 짐볼과 탄성밴드를 활용한 근력운동을 적용하였으며, 프로그램 참여에 따른 여가시간 사용의 변화를 조사하기 위해 매월 시간 조사표 기록에 따른 총시간, 운동 빈도를 조사하였고, 여가활동 수행에 미치는 영향을 분석하기 위해 프로그램 전, 후 캐나다작업수행측정(COPM)을 활용하여 동적 여가활동에서의 수행도와 만족도를 분석하였다. 수집된 자료는 SPSS ver.18.0으로 기술통계, 프리드만 검정(Friedman), 윌콕슨 부호순위 검정(Wilcoxon's Signed-Ranks Test)을 실시하였다. 결과 : 여가시간 사용의 분석 결과 총시간, 운동 빈도에서 프로그램 참여 후 통계적으로 유의미하게 지속적으로 증가하였으며, 여가활동 수행의 분석 결과 동적 여가활동에서의 수행도, 만족도에서 프로그램 참여 후 통계적으로 유의미하게 증가하였다. 결론 : 재활체육 프로그램의 참여가 대상자들의 여가시간 사용을 효과적으로 변화시킬 수 있는 긍정적인 요인으로 작용할 수 있어 시설에 거주하고 있는 지적장애인들에게 재활체육 프로그램의 참여는 필수적이다. 또한, 이러한 프로그램을 지속적으로 제공하고, 체계적으로 발전시키고 관리하여, 지적장애인들의 여가생활의 질을 높이고 시설 내 생활과 하루일과의 만족도를 높이는 데 기여할 수 있을 것이다.