• 제목/요약/키워드: analysis with repeated measurements

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Sex Determination Using a Discriminant Analysis of Maxillary Sinuses and Three-Dimensional Technology

  • Jeong-Hyun Lee;Hee-Jeung Jee;Eun-Seo Park;Seok-Ho Kim;Sung-Suk Bae
    • Journal of dental hygiene science
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    • v.22 no.4
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    • pp.249-255
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    • 2022
  • Background: Sexual dimorphism is important for sex determination in the field of forensics. However, sexual dimorphism is commonly assessed using cone beam computed tomography (CBCT) rather than three-dimensional (3D) modeling software; therefore, studies using a more accurate measurement approach are necessary. This study assessed the sexual dimorphism of the MS using a 3D modeling program to obtain information that could contribute to the fields of surgery and forensics. Methods: The CBCT data of 60 patients (age, 20~29 y; 30 males and 30 females) admitted to the Department of Orthodontics at the Dankook University School of Dentistry were provided in Digital Imaging and Communications in Medicine (DICOM) format. The left MS and right MS were modeled based on the DICOM files using the Mimics (version 22; Materialise, Leuven, Belgium) 3D program and converted to stereolithography (STL) files used to measure the width, length, and height of the MS, infraorbital foramen (IOF), right MS, and left MS. The average of three repeated measurements was calculated, and a reliability test was performed to ensure data reliability (Cronbach's α=0.618). A canonical discriminant analysis was performed using a standard approach (left: Box's M=0.096; right: Box's M=0.115). Results: Males had greater values for all parameters (MS width, MS length, MS height, IOF, right MS, left MS) than females. The discriminant analysis identified six independent variables (MS width, MS height, MS length, IOF, right MS, left MS) that could identify sex. The left MS and right MS correctly identified the sex of 81.7% and 71.7% of the patients, respectively, with the left MS having higher accuracy. Conclusion: This study confirmed that, for Korean individuals, the left MS has a better ability to identify sex than the right MS. These results may contribute to sex identification in the fields of surgery and forensics.

Effects of Different Chair Heights on Ground Reaction Force and Trunk Flexion during Sit-to-Stand in the Elderly

  • Lee, Na-Kyung;Lee, Myoung-Hee
    • The Journal of Korean Physical Therapy
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    • v.26 no.6
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    • pp.449-452
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    • 2014
  • Purpose: The purpose of this study was to analyze the coordination between trunk flexion and lower limb extension contributing to vertical propulsion during sit-to-stand (STS) at different chair heights in the elderly. Methods: Ten elderly subjects were asked to stand up at their natural speed from different chair heights : (1) $90^{\circ}$ knee flexion; (2) $100^{\circ}$ knee flexion; (3) $110^{\circ}$ knee flexion; and (4) $120^{\circ}$ knee flexion. A standard chair without a backrest or armrests was used in this study. To remove inertial effects of upper limb movements, subjects were asked to stand up from a chair with their arms crossed at the chest. Mean of results of three trials were used in the analysis at different knee flexion angles. Distances moved by the shoulder for compensatory trunk movement was recorded by motion analysis and vertical force was recorded under foot using force plates. Distances moved by the shoulder and vertical ground reaction force measurements were analyzed using repeated ANOVA. Results: Distances moved by the shoulder significantly decreased with higher chair (p<0.05). Vertical forces were not significant difference on chair heights (p>0.05), but results of pairwise comparisons for vertical force revealed significant difference between $90^{\circ}$ knee flexion and $120^{\circ}$ knee flexion (p<0.05). Conclusion: Trunk movement is probably used as a compensatory mechanism at low chair heights to increase lift-off from sitting by the elderly.

Maxillary first molar wear: a longitudinal study of children

  • Kim, Won-Hee;Nam, Shin-Eun;Park, Young-Seok;Lee, Seung-Pyo
    • Anatomy and Cell Biology
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    • v.51 no.4
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    • pp.251-259
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    • 2018
  • The aim of this study is to examine the correlation between tooth wear and age by quantitatively measuring maxillary first molar wear in children. A total of 150 maxillary dental models were analyzed in 30 subjects (male, 11; female, 19) with an age range of 6-14 years. Maxillary first molar wear were assessed based on area, volume and the shortest distance from the buccal occlusal plane to the central pit point (BCPH). The area and volume of the tooth cusps were measured at four different offset-plane heights (0.2, 0.4, 0.6, and 0.8 mm). Relationship between age and the amount of wear or BCPH were statistically analyzed. Correlation and regression analyses were also performed, and age estimation was obtained with linear regression analysis. Repeated measures analysis of variance (ANOVA) revealed significant differences between age and the amount of wear based on area, volume, and offset-plane height. Except age of 8 and 10, 12 and 14's 0.2-mm offset-plane-measured volume, all area and volume measurement of all ages and offset-plane height showed a significant amount of increase. Wear speeds were calculated using the BCPH. Among age and measurement variables, the correlation coefficient was strongest when the volume was measured from the 0.4-mm offset-plane. As age increases, the amount of wear, as quantified by area and volume measurements, also increases. According to this study, a regression equation that can be used for age estimation is follows: Age $(y)=0.16{\times}0.4V+0.85$ ($R^2=0.490$) using volume.

Development of a Noble Gas Isotope Dilution Mass Spectrometric System Combined with a Cryogenic Cold Trap (초저온 냉각 트랩을 결합한 비활성기체 동위원소 희석 질량분석 시스템의 제작)

  • HONG, BONGJAE;SHIN, DONGYOUB;PARK, KEYHONG;HAHM, DOSHIK
    • The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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    • v.27 no.3
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    • pp.144-157
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    • 2022
  • Noble gases, which are chemically inert and behave conservatively in marine environments, have been used as tracers of physical processes such as air-sea gas exchange, mixing of water masses, and distribution of glacial meltwater in the ocean. For precise measurements of Ne, Ar, and Kr, we developed a mass spectrometric system consisting of a quadrupole mass spectrometer (QMS), a high vacuum preparation line, an activated charcoal cryogenic trap (ACC), and a set of isotope standard gases. The high vacuum line consists of three sections: (1) a sample extraction section that extracts the dissolved gases in the sample and mixes them with the standard gases, (2) a gas preparation section that removes reactive gases using getters and separates the noble gases according to their evaporation points with the ACC, and (3) a gas analysis section that measures concentrations of each noble gas. The ACC attached to the gas preparation section markedly lowered the partial pressures of Ar and CO2 in the QMS, which resulted in a reduced uncertainty of Ne isotope analysis. The isotope standard gases were prepared by mixing 22Ne, 36Ar, and 86Kr. The amounts of each element in the mixed standard gases were determined by the reverse isotope dilution method with repeated measurements of the atmosphere. The analytical system achieved precisions for Ne, Ar, and Kr concentrations of 0.7%, 0.7%, and 0.4%, respectively. The accuracies confirmed by the analyses of air-equilibrated water were 0.5%, 1.0%, and 1.7% for Ne, Ar, and Kr, respectively.

The Effect of Body Positioning on Physiologic Index in Patients with Unilateral Lung Disease (편측성 폐질환 환자의 체위변경이 생리적 지표에 미치는 영향)

  • Cho, Jee Yeon;Lee, Hyang Yeon
    • Korean Journal of Adult Nursing
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    • v.12 no.1
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    • pp.122-133
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    • 2000
  • The purpose of this study was to identify the effect of body positioning on $PaO_2$, $SpO_2$, systolic blood pressure, diastolic blood pressure, pulse, and respiration(above all defined physiologic index), of patients with unilateral lung disease. The subjects for this study were eleven patients admitted to I.C.U. of K.H.M.C. with a diagnosis of unilateral lung disease confirmed by chest X-ray and the attending doctor, from January 30th. to April 20th. 1999. A quasi-experimental repeated-measures cross-over design was used to compare three body positions(semi-Fowler's, lateral decubitus with good lung dependent, and lateral decubitus with diseased lung dependent). Each subject spent 30 minutes in semi-Fowler's position and 2 hours in good lung dependent position and diseased lung dependent position. Starting in the semi-Fowler's position, then in the lateral position with the good lung dependent or the diseased lung dependent as assigned in random order. Thirty minutes after each positioning, arterial blood sample was analyzed. Measurements of all physiologic index were recorded at the specified intervals(0, 30, 60 90, and 120 minutes) in good lung dependent and diseased lung dependent position. Statistical comparison of $PaO_2$ value was done using the Wilcoxon Signed Rank Test, and Multivariate repeated-measures analysis of variance was performed to analyse the within-subject effect of two dependent position for 2 hours on the five dependent variables: (1) $PaO_2$ (2) $SpO_2$ (3) systolic blood pressure (4) diastolic blood pressure (5) pulse. The results obtained were as follows: 1. The $PaO_2$ value in the good lung dependent position was significantly higher than the $PaO_2$ value in the diseased lung dependent position(Z=-2.8451, p=.002). 2. The $PaO_2$ value in the good lung dependent position was significantly higher than the $PaO_2$ value in the semi-Fowler's position (Z=-2.6673, p=.003). 3. The difference between the $PaO_2$ value in the semi-Fowler's position and the $PaO_2$ value in the diseased lung dependent position was not significant(Z=-1.2448, p=.10). 4. There were no statistically significance in the trends of physiologic index in the good lung dependent position and the diseased lung dependent position. From the results, it may be concluded that the good lung dependent position is the most effective position for patients with unilateral lung disease that improve oxygenation. Identification of positioning over time may be need further studies.

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Color assessment of resin composite by using cellphone images compared with a spectrophotometer

  • Rafaella Mariana Fontes de Braganca;Rafael Ratto Moraes ;Andre Luis Faria-e-Silva
    • Restorative Dentistry and Endodontics
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    • v.46 no.2
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    • pp.23.1-23.11
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    • 2021
  • Objectives: This study assessed the reliability of digital color measurements using images of resin composite specimens captured with a cellphone. Materials and Methods: The reference color of cylindrical specimens built-up with the use of resin composite (shades A1, A2, A3, and A4) was measured with a portable spectrophotometer (CIELab). Images of the specimens were obtained individually or pairwise (compared shades in the same photograph) under standardized parameters. The color of the specimens was measured in the images using RGB system and converted to CIELab system using image processing software. Whiteness index (WID) and color differences (ΔE00) were calculated for each color measurement method. For the cellphone, the ΔE00 was calculated between the pairs of shades in separate images and in the same image. Data were analyzed using 2-way repeated-measures analysis of variance (α = 0.05). Linear regression models were used to predict the reference ΔE00 values of those calculated using color measured in the images. Results: Images captured with the cellphone resulted in different WID values from the spectrophotometer only for shades A3 and A4. No difference to the reference ΔE00 was observed when individual images were used. In general, a similar ranking of ΔE00 among resin composite shades was observed for all methods. Stronger correlation coefficients with the reference ΔE00 were observed using individual than pairwise images. Conclusions: This study showed that the use of cellphone images to measure the color difference seems to be a feasible alternative providing outcomes similar to those obtained with the spectrophotometer.

Damage detection in beam-like structures using deflections obtained by modal flexibility matrices

  • Koo, Ki-Young;Lee, Jong-Jae;Yun, Chung-Bang;Kim, Jeong-Tae
    • Smart Structures and Systems
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    • v.4 no.5
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    • pp.605-628
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    • 2008
  • In bridge structures, damage may induce an additional deflection which may naturally contain essential information about the damage. However, inverse mapping from the damage-induced deflection to the actual damage location and severity is generally complex, particularly for statically indeterminate systems. In this paper, a new load concept, called the positive-bending-inspection-load (PBIL) is proposed to construct a simple inverse mapping from the damage-induced deflection to the actual damage location. A PBIL for an inspection region is defined as a load or a system of loads which guarantees the bending moment to be positive in the inspection region. From the theoretical investigations, it was proven that the damage-induced chord-wise deflection (DI-CD) has the maximum value with the abrupt change in its slope at the damage location under a PBIL. Hence, a novel damage localization method is proposed based on the DI-CD under a PBIL. The procedure may be summarized as: (1) identification of the modal flexibility matrices from acceleration measurements, (2) design for a PBIL for an inspection region of interest in a structure, (3) calculation of the chord-wise deflections for the PBIL using the modal flexibility matrices, and (4) damage localization by finding the location with the maximum DI-CD with the abrupt change in its slope within the inspection region. Procedures from (2)-(4) can be repeated for several inspection regions to cover the whole structure complementarily. Numerical verification studies were carried out on a simply supported beam and a three-span continuous beam model. Experimental verification study was also carried out on a two-span continuous beam structure with a steel box-girder. It was found that the proposed method can identify the damage existence and damage location for small damage cases with narrow cuts at the bottom flange.

The Effects of Sciatic Nerve Mobilization on Hamstring Flexibility, Lower Limb Strength and Gait Performance in Patients With Chronic Stroke

  • Shin, Yun-hyeok;Chon, Seung-chul
    • Physical Therapy Korea
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    • v.22 no.4
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    • pp.8-16
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    • 2015
  • The purpose of this study was to evaluate the effects of mobilization of the sciatic nerve on hamstring flexibility, lower limb strength, and gait performance in patients with chronic stroke. This study was a randomized clinical trial with a crossover design. Sixteen subjects were recruited for this study. The subjects were randomly divided into two intervention groups and underwent either of the following two interventions: sciatic nerve mobilization or static stretching of the hamstring. We assessed hamstring flexibility, lower limb strength, and gait performance using a digital inclinometer, a hand-held dynamometer, and the 10-meter walk test, respectively. Subjects had a 24-hour rest period between each session in order to minimize carryover effects. Measurements for each test were assessed prior to and immediately after the intervention sessions. Using a two-way analysis of variance test with repeated measures, data from the two trials were analyzed by comparing the differences between both techniques. The level of statistical significance was set at .05. Sciatic nerve mobilization resulted in significantly better knee extensor strength (p=.023, from $15.32{\pm}5.98$ to $18.16{\pm}6.95kg$) and knee flexor strength (p=.011, from $7.80{\pm}4.80$ to $8.15{\pm}4.24kg$) in the experimental group than in the control group. However, no significant effects of static stretching of the hamstring were observed on hamstring flexibility from the ankle plantar flexion (p=.966) and ankle neutral positions (p=.210) and on gait performance (p=.396). This study indicated that the sciatic nerve mobilization technique may be more effective in muscle activation of the knee extensor muscle and knee flexor muscle than hamstring static stretching technique in patients with chronic stroke.

The Effect of Initial Cognitive Status on the Recovery of Functional Status in Patients with Subacute Stroke (초기 인지상태가 아급성기 뇌졸중 환자의 기능상태 회복에 미치는 영향)

  • Hong, Jeong-Min;Kim, Min-Hee
    • PNF and Movement
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    • v.19 no.3
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    • pp.351-359
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    • 2021
  • Purpose: This purpose of this study was to investigate the effects of initial cognitive status on the recovery of functional status in patients with subacute stroke. Methods: The participants were 111 patients with subacute stroke, divided into two groups: mini-mental state examination (MMSE) <20 (n=49) group and MMSE ≥20 (n=62) group. Clinical evaluation scores were collected before and after rehabilitation. The repeated measurements ANOVA was used to confirm the changes in functional status before and after intervention in the two groups. Changes in functional status within the group were examined through a paired test. A Pearson correlation coefficient analysis was performed to identify the correlation between MMSE change amount and functional status score. Results: In each of the two groups, according to the initial cognitive status, the clinical evaluation score increased statistically significantly, but there was no difference between the two groups in the degree of significant increase. When examining the correlation between the MMSE change amount, according to the initial cognitive state and the functional state score change amount, it was found, only in the group with MMSE <20, that the larger the change in the MMSE score, the greater the functional state change of Berg balance scale, Rivermead Mobility Index, and motor assessment scale. This did not apply to the group with MMSE ≥20. Conclusion: Initial cognitive status should be considered when setting the patient's goal, and considering cognitive improvement when constructing a rehabilitation program is thought to have a positive effect on rehabilitation services.

Clinical usefulness of facial soft tissues thickness measurement using 3D computed tomographic images (3차원 전산화단층촬영 영상을 이용한 안면 연조직 두께 계측의 임상적 유용성)

  • Jeong Ho-Gul;Kim Kee-Deog;Han Seung-Ho;Hu Kyung-Seok;Lee Jae-Bum;Park Hyok;Choi Seong-Ho;Kim Chong-Kwan;Park Chang-Seo
    • Imaging Science in Dentistry
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    • v.36 no.2
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    • pp.89-94
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    • 2006
  • Purpose : To evaluate clinical usefulness of facial soft tissue thickness measurement using 3D computed tomographic images. Materials and Methods : One cadaver that had sound facial soft tissues was chosen for the study. The cadaver was scanned with a Helical CT under following scanning protocols about slice thickness and table speed; 3 mm and 3 mm/sec, 5 mm and 5 mm/sec, 7 mm and 7 mm/sec. The acquired data were reconstructed 1.5, 2.5, 3.5 mm reconstruction interval respectively and the images were transferred to a personal computer. Using a program developed to measure facial soft tissue thickness in 3D image, the facial soft tissue thickness was measured. After the ten-time repeation of the measurement for ten times, repeated measure analysis of variance (ANOVA) was adopted to compare and analyze the measurements using the three scanning protocols. Comparison according to the areas was analyzed by Mann-Whitney test. Results : There were no statistically significant intraobserver differences in the measurements of the facial soft tissue thickness using the three scanning protocols (p>0.05). There were no statistically significant differences between measurements in the 3 mm slice thickness and those in the 5 mm, 7 mm slice thickness (p>0.05). There were statistical differences in the 14 of the total 30 measured points in the 5 mm slice thickness and 22 in the 7 mm slice thickness. Conclusion : The facial soft tissue thickness measurement using 3D images of 7 mm slice thickness is acceptable clinically, but those of 5 mm slice thickness is recommended for the more accurate measurement.

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