• Title/Summary/Keyword: Reproducibility of the results

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Study on the Sun Screen Test Method using Elipsometer (분광타원해석기를 이용한 자외선 차단제의 평가방법 연구)

  • Kim, Joon-Woo;Lee, Jong-Soo;Lee, Ji-Hye;Choung, Suk-Jin
    • Journal of the Society of Cosmetic Scientists of Korea
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    • v.37 no.2
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    • pp.137-141
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    • 2011
  • Sunscreen is divided into the organic agent of UV absorption and inorganic agent of reflection. These are evaluated by sun protection factor (SPF) in-vivo test requiring high cost and time, while in-vitro tests are adopted commonly because of short test time, easy result collection. Generally, test method of SPF use SPF 290a by UV-vis spectrometer. The evaluate by SPF 290 has low reproducibility. Although analysis using UV-vis spectrometer has high reproducibility, it is hard to separated results of transmission, adsorption, and reflection. In this study, suggested method of elipsometer has some merit such as high reproducibility, easy separation of transmission/adsorption/re- flection, analysis using various incident angle. We tested the validity of elipsometer for SPF measurement, using commercially available sun-block (SPF 50).

Accuracy and reproducibility of landmark of cone beam computed tomography (CT) synthesized cephalograms (Cone beam computed tomography로 합성된 두부규격 방사선사진에서의 각 계측점의 정확도와 재현성에 관한 연구)

  • Kwon, Dae-Keun;Min, Seung-Ki;Jun, In-Chul;Paeng, Jun-Young
    • Journal of the Korean Association of Oral and Maxillofacial Surgeons
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    • v.36 no.2
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    • pp.78-86
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    • 2010
  • Introduction: Cone beam computed tomography (CBCT) has various advantages and is used favorably in many fields in dentistry. Especially, CBCT is being used as basic diagnostic tool for 3-dimensional analysis in orthognathic patient. Two-dimensional cephalograms can be synthesized from CBCT digital imaging and communications in medicine (DICOM) data. In this study, conventional cephalograms and CBCT were taken simultaneously, and representative landmarks were located and analyzed in its accuracy and reproducibility. Materials and Methods: Ten patients who had orthognathic surgery in Wonkwang University Daejeon Dental Hospital participated in this study. For each patient, CBCT and conventional cephalogram was taken. By using Ondemand (Cybermad, Korea), 2-dimensional cephalograms was established on CBCT. In addition, 19 landmarks were designated and measured by 3 orthodontists twice a week. After these landmarks were transferred to a coordinate, distance of landmark and axis, standard error, distribution degree were measured, compared and analyzed. Results: Comparing the CT ceph group and conventional cephalogram group, CT ceph group had shown shorter distance of landmark and axis in S, Hinge axis, Bpt, Ba, Or, Corpus left. Standard error of the mean shows that CT ceph group has better reproducibility in Or, Corpus left, Hinge axis at X axis and Na, U1R, U1T, Bpt, PNS, Ba Corpus left, Hinge axis at Y axis. In both groups, mean error was less than 1.00 mm, no significant difference were found between CT ceph group and conventional cephalogram group in all measurements. Furthermore, comparing two groups, each 17 landmarks out of 19 had its characteristic in distribution degree. Conclusion: No significant difference were found between CBCT composed cephalographic radiograph and conventional cephalograghic radiograph, clinical application may be possible if improved.

Reproducibility of Regional Pulse Wave Velocity in Healthy Subjects

  • Im Jae-Joong;Lee, Nak-Bum;Rhee Moo-Yong;Na Sang-Hun;Kim, Young-Kwon;Lee, Myoung-Mook;Cockcroft John R.
    • International Journal of Vascular Biomedical Engineering
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    • v.4 no.2
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    • pp.19-24
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    • 2006
  • Background: Pulse wave velocity (PWV), which is inversely related to the distensibility of an arterial wall, offers a simple and potentially useful approach for an evaluation of cardiovascular diseases. In spite of the clinical importance and widespread use of PWV, there exist no standard either for pulse sensors or for system requirements for accurate pulse wave measurement. Objective of this study was to assess the reproducibility of PWV values using a newly developed PWV measurement system in healthy subjects prior to a large-scale clinical study. Methods: System used for the study was the PP-1000 (Hanbyul Meditech Co., Korea), which provides regional PWV values based on the measurements of electrocardiography (ECG), phonocardiography (PCG), and pulse waves from four different sites of arteries (carotid, femoral, radial, and dorsalis pedis) simultaneously. Seventeen healthy male subjects with a mean age of 33 years (ranges 22 to 52 years) without any cardiovascular disease were participated for the experiment. Two observers (observer A and B) performed two consecutive measurements from the same subject in a random order. For an evaluation of system reproducibility, two analyses (within-observer and between-observer) were performed, and expressed in terms of mean difference ${\pm}2SD$, as described by Bland and Altman plots. Results: Mean and SD of PWVs for aorta, arm, and leg were $7.07{\pm}1.48m/sec,\;8.43{\pm}1.14m/sec,\;and\;8.09{\pm}0.98m/sec$ measured from observer A and $6.76{\pm}1.00m/sec,\;7.97{\pm}0.80m/sec,\;and\;\7.97{\pm}0.72m/sec$ from observer B, respectively. Between-observer differences ($mean{\pm}2SD$) for aorta, arm, and leg were $0.14{\pm\}0.62m/sec,\;0.18{\pm\}0.84m/sec,\;and\;0.07{\pm}0.86m/sec$, and the correlation coefficients were high especially 0.93 for aortic PWV. Within-observer differences ($mean{\pm}2SD$) for aorta, arm, and leg were $0.01{\pm}0.26m/sec,\;0.02{\pm}0.26m/sec,\;and\;0.08{\pm}0.32m/sec$ from observer A and $0.01{\pm}0.24m/sec,\;0.04{\pm}0.28m/sec,\;and\;0.01{\pm}0.20m/sec$ from observer B, respectively. All the measurements showed significantly high correlation coefficients ranges from 0.94 to 0.99. Conclusion: PWV measurement system used for the study offers comfortable and simple operation and provides accurate analysis results with high reproducibility. Since the reproducibility of the measurement is critical for the diagnosis in clinical use, it is necessary to provide an accurate algorithm for the detection of additional features such as flow wave, reflection wave, and dicrotic notch from a pulse waveform. This study will be extended for the comparison of PWV values from patients with various vascular risks for clinical application. Data acquired from the study could be used for the determination of the appropriate sample size for further studies relating various types of arteriosclerosis-related vascular disease.

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Experimental Study with Respect to Dose Characteristic of Glass Dosimeter for Low-Energy by Using Internal Detector of Piranha 657 (Piranha 657의 Internal Detector를 이용한 저에너지에서 유리선량계의 선량 특성에 관한 연구)

  • Son, Jin-Hyun;Min, Jung-Whan;Kim, Hyun-Soo;Lyu, Kwang-Yeul;Lim, Hyun-Soo;Kim, Jung-Min;Jeong, Hoi-Woun
    • Journal of radiological science and technology
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    • v.35 no.2
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    • pp.119-124
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    • 2012
  • Recently, Glass Dosimeter (GD) with thermoluminescent Dosimeter (TLD) are comprehensively used to measure absorbed dose from diagnostic field to therapy field that means from low energy field to high energy field. However, such studies about dose characteristics of GD, such as reproducibility and energy dependency, are mostly results in high energy field. Because characteristic study for measurement devices of radiation dose and radiation detector is performed using 137Cs and 60Co which emit high energy radiations. Thus, this study was evaluated the linearity according to Piranha dose which measured by changing tube voltage (50kV, 80kV and 100kV which are low energy radiations), reproducibility and reproducibility according to delay time using GD. Measurement of radiation dose is performed using internal detector of Piranha 657 which is multi-function QA device (RTI Electronic, Sweden). Condition of measurement was 25mA, 0.02sec, 2.5mAs, SSD of 100 cm and exposure area with $10{\times}10cm^2$. As above method, GD was exposed to radiation. Sixty GDs were divided into three groups (50kV, 80kV, 100kV), then measured. In this study, GD was indicated the linearity in low energy field as high energy existing reported results. The reproducibility and reproducibility according to delay time were acceptable. In this study, we could know that GD can be used to not only measure the high energy field but also low energy field.

Use of autonomous maximal smile to evaluate dental and gingival exposure

  • Wang, Shuai;Lin, Hengzhe;Yang, Yan;Zhao, Xin;Mei, Li;Zheng, Wei;Li, Yu;Zhao, Zhihe
    • The korean journal of orthodontics
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    • v.48 no.3
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    • pp.182-188
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    • 2018
  • Objective: This study was performed to validate the autonomous maximal smile (AMS) as a new reference for evaluating dental and gingival exposure. Methods: Digital video clips of 100 volunteers showing posed smiles and AMS at different verbal directives were recorded for evaluation a total of three times at 1-week intervals. Lip-teeth relationship width (LTRW) and buccal corridor width (BCW) were measured. LTRW represented the vertical distance between the inferior border of the upper vermilion and the edge of the maxillary central incisors. Intraclass correlation coefficients (ICCs) for reproducibility, and the m-value (minimum number of repeated measurements required for an ICC level over 0.75), were calculated. Results: LTRW and BCW of the AMS were 1.41 and 2.04 mm, respectively, greater than those of the posed smile (p < 0.05), indicating significantly larger dental and gingival exposure in the AMS. The reproducibility of the AMS (0.74 to 0.77) was excellent, and higher than that of the posed smile (0.62 to 0.65), which had fair-to-good reproducibility. Moreover, the m-value of the AMS (0.88 to 1.05) was lower than that of the posed smile (1.59 to 1.85). Conclusions: Compared to the posed smile, the AMS shows significantly larger LTRW and BCW, with significantly higher reproducibility. The AMS might serve as an adjunctive reference, in addition to the posed smile, in orthodontic and other dentomaxillofacial treatments.

Reproducibility and Validity of a Self-Administered Semiquantitative Food Frequency Questionnaire (자기기록식 반정량 식이섭취 빈도조사의 신뢰도 및 타당도 연구)

  • 김미경;이상선;안윤옥
    • Korean Journal of Community Nutrition
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    • v.1 no.3
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    • pp.376-394
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    • 1996
  • This study evaluated the reproducibility and validity of the self-administered semiquantitative food frequency questionnaire used in a large prospective cohort study(Korean Cancer Research Survey) in middle-aged men. The questionnaire was administered twice at an interval of approximately two years(December, 1992-January, 1995), and four or five 24-hour recalls for each subject were collected at intervals of approximately three months. The results were as follows; 1) Although the distributions of the data estimated by the questionnaire were somewhat wider, the mean nutrient intakes of group estimated by our questionnaires and the multiple 24-hour recalls were roughly comparable. 2) The reproducibility determined by correlation of absolute(unadjusted nutrient intake) and calorie adjusted nutrient intakes from two semiquantitative food frequency questionnaires were more than 0.5, and the weighted kappa values were more than 0.4. 3) The Pearson correlation coefficients between unadjusted nutrient intakes values were average 0.40 on the average(Ca, 0.13-Carbohydrate, 0.58) at the first questionnaire vs. 24-hour recalls, and 0.28 at the second questionnaire vs. 24-hour recalls. The spearman rank order correlation coefficients were similar. When energy intake was adjusted, there was a slight reduction : 0.28 at the second questionnaire, 0.25 average on the second. In order to correct the measurement error of 24-hour recall data, the deattenuated correlation coefficient was calculated. It averaged 0.53 on the first questionnaire, 0.37 on the second questionnaire for unadjusted nutrient intake. for calorie-adjusted nutrient intake, it averaged 0.44 on the first questionnaire, 0.37 on the second questionnarie. 4) There was lower agreement(k<0.4) between the questionnaries and the 24-hour recalls. And the subjects classified in the same quartile by 24-hour recalls and first questionnaire were average 37$\%$(energy-adjusted values) and 40$\%$(unadjusted values) on the average. More than k10$\%$(average) of subjects were in the extreme quartile of the questionnarie and 24-hour recall method. But 8.2$\%$(average) of subjects classified in the lowest quartile of unadjusted nutrient intake level by the 24-hour recalls were in the highest quartile by the first questionnaire. These data indicate that our self-administered semiquantitative food frequency questionnarie is reproducible. Correlation coefficients comparing nutrient intakes measured by two different dietary assessment methods were less than 0.5. The validity of our questionnarie is not high enough.

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A Study on the Aesthetics of death in Alexander McQueen's works (알렉산더 맥퀸(Alexander McQueen) 작품에 나타난 죽음의 미학)

  • Wang, Xin-yu;Kim, Hyun-joo
    • Journal of Digital Convergence
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    • v.18 no.5
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    • pp.455-463
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    • 2020
  • This researcher has sorted out the development process of death aesthetics contained in human art through advanced research. This research is a follow-up study of related research, which studies the aesthetic meaning of death in Alexander McQueen's fashion works. This study first classifies the aesthetic characteristics of death, and then analyzes and sorts out the aesthetics of death in Alexander McQueen's clothing works based on this. The results of this study are as follows: first, the aesthetic manifestations of death are divided into three categories: reproducibility, symbolic and religious. Among them, the representation of reproducibility includes the representation of real objects and the representation of virtual objects, and the symbolic performance includes two types of external performance and internal performance. Second, in Alexander McQueen's works, the reproducibility of death was mainly reflected by virtual stage scenes and costumes. Thirdly, the symbolic death is not only reflected in the skeletons and blood etc. directly related to the death of the body, but also in the various emotions and psychological states caused by the death. Fourth, the religious nature of death was represented in Alexander McQueen's works through such representative things as crosses and religious stories.

Gage R&R Study on Abdominal Sonography for Measuring Distance from Sangwan (CV13) to Pancreas - A Pilot Study - (복부초음파를 이용한 상완혈(上脘穴)-췌장 수직거리 측정시스템의 재현성 반복성 평가실험-A Pilot Study-)

  • Nam, Dong-Hyun
    • The Journal of the Society of Korean Medicine Diagnostics
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    • v.14 no.2
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    • pp.75-84
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    • 2010
  • Objectives: The objective of the current study is to determine whether an ultrasound device system is adequate for measuring distance from Sangwan (CV13) to pancreas. Methods: We recruited 3 healthy young male subjects and 2 sonographers. The each sonographer measured vertical shortest distance from CV13 to pancreas with a ultrasound device three times in random order. Because the total variation could be divided into repeatability, reproducibility and subject-to-subject variation in Gage R&R method, we compared the sources of variation associated with the measurement system with an analysis of variance model. Results & Conclusions: Number of distinct categories is calculated on the basis of standard deviation of subject-to-subject divided by standard deviation of total Gage R&R. If the number of categories is five or more, the measurement system may be acceptable for the analysis of the process. The number of distinct categories of the ultrasound device system for measuring distance from CV13 to pancreas was 6.29. So we concluded that repeatability and reproducibility of the ultrasound device system for measuring distance from CV13 to pancreas was acceptable.

Validation of Kinetic Method for the PKA Assay in Plasma-Derived Products

  • Shin, In-Soo;Hong, Choong-Man;Koh, Hyun-Chul;Hong, Seung-Hwa
    • Biomolecules & Therapeutics
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    • v.13 no.1
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    • pp.59-63
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    • 2005
  • A kinetic assay was carried out in order to compare the ability of detection for prekallikrein activator(PKA) in plasma-derived products with that of an endpoint assay and a commercial method. Using these methods, 9 human albumin preparations were assayed and compared to each other. The coefficient of variation between the Kinetic assay and the end point assay was found within 6.6% and this result showed that two methods were highly correlative and the end point assay could act as a replacement of the kinetic assay. Another important goal of this study was to investigate the reproducibility among laboratories on the kinetic assay. A collaborative study was performed to validate the kinetic method with intra and inter assays. The coefficient of variation for the intra assay of each laboratory was less than 4% and that for between individuals in the inter assay was 4.1%. These results revealed that the kinetic assay showed good reproducibility. The contents of PKA in plasma-derived products were also determined by the kinetic assay. As a result, it was found that trace amounts of PKA were present in 32 human immunoglobulin preparations, however the average concentration of PKA in 171 albumin preparations was 5.8 IU/mL.

A Study on the Effects of Immediate Side Shift to the Pantographic Reproducibility Index (Immediate Side Shift가 Pantographic Reproducibility Index에 끼치는 영향에 관한 연구)

  • Nam, Cheon Woo;Han, Kyung Soo
    • Journal of Oral Medicine and Pain
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    • v.12 no.1
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    • pp.75-83
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    • 1987
  • This study was designed to investigate the effects of TMJ incoordination to condylar movements, especially, the ISS. The sounds are one of the symptoms in TMJ incoordinated disorder, and it may cause the changes of mandibular movement trajectory. 19 students with only TMJ sounds and 16 students with no TMJ problems participated in this study. The subject performed Rt. lateral, Lt. lateral and protrusive movements, and repeated 3 times on each movement. Pantronic was used to record the measures of condylar movement paths. The obtained results were as follows : 1. The mean values of RISS and LISS in control group were 0.29mm, 0.36mm respectively, and those in experimental group were 0.49mm, 0.41mm repectively. The mean values of RISS was higher in experimental group than that of RISS in control group. 2. Correlation coefficients between PRI and RISS, LISS were slightly higher in experimental group than those in control group, therefore, PRI was more likely to be affected by ISS in experimental group. 3. In control group PRI was correlated to RISS, LORB, RPRO and LPRO, but in experimental group PRI was not correlated to those items. From the study, the author knew that the condylar movements was stable in control group.

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