• Title/Summary/Keyword: Reproducibility evaluation

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A Study on Reproducibility of Mandibular Movements Using Pantographic Reproducibility Index (PRI) (Pantographic Reproducibility Index(PRI)를 이용한 하악운동의 재현성에 관한 연구)

  • Lee, Sang-Don;Park, Charn-Woon
    • The Journal of Korean Academy of Prosthodontics
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    • v.24 no.1
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    • pp.105-116
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    • 1986
  • In order to determine if a relationship exists between the clinical symptoms of TMJ dysfunction and the reproducibility of mandibular movements, twenty one subjects were chosen. The control group consisted of 5 subjects who were determined to be free from signs and symptoms of dysfunction . The sixteen experimental subjects were selected on the basis of their having dysfunctional symptoms. The author obtained two sets of pantographic tracings. Each set consisted of tracings from three both lateral and one protrusive movements. A second set of tracings were recorded immediately on the new recording papers using the same procedure as the first tracing. The tracings were scored by Pantographic reproducibility index (PRI). The obtained results were as follows. 1. Mean PRI scores of groups increased as the degree of dysfunction were increased. 2. For the groups of no or slight dysfunctional symptoms the PRI scores of the second tracing were smaller than the first one, wherea the scores of the second tracing from $D_2,\;D_3$ group were larger than the first tracing. 3. Differences between the mean PRI scores of control group and those of experimental group were statistically significant. 4. The second sets of tracings were more reliable statistically than those of first ones. 5. PRI can be used as a meaningful aid for the evaluation of the diagnostic and therapeutic results of treatment modalities for the TMJ dysfunction. 6. At 3east two sets of tracings should be recorded when the PRI is to be used to detect the incoordinated movements of TMJ dysfunction patient. 7. PRI scores of control group ($D_0$) was 137.7, thus, mandibular movement was reproducible, whereas PRI scores of experimental groups ($D_1,\;D_2,\;D_3$) were 22.5, 27.7, 30.45 respectively, thus were nonreproducible.

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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.

Establishment of Analytical Method for Residues of Ethychlozate, a Plant Growth Regulator, in Brown Rice, Mandarin, Pepper, Potato, and Soybean Using HPLC/FLD

  • Kim, Jae-Young;Lee, Jin Hwan;Lee, Sang-Mok;Chae, Young-Sik;Rhee, Gyu-Seek;Chang, Moon-Ik
    • Korean Journal of Environmental Agriculture
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    • v.34 no.2
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    • pp.111-119
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    • 2015
  • BACKGROUND: Ethychlozate (ECZ) is a plant growth regulator of synthetic auxin for agricultural commodities (ACs). Accurate and sensitive method to determine ECZ in diverse ACs on global official purpose is required to legal residue regulation. As the current official method is confined to the limited type of crops with poor validation, this study was conducted to improve and extend the ECZ method using high-performance liquid chromatography (HPLC) in all the registered crops with method verification. METHODS AND RESULTS: ECZ and its acidic metabolite (ECZA) were both extracted from acidified samples with acetone and briefly purified by dichloromethane partition. ECZ was hydrolyzed to form ECZA and the combined ECZA was finally purified by ion-associated partition including hexane-washing. The instrumental quantitation was performed using HPLC/ FLD under ion-suppression of ECZA with no interference by sample co-extractives. The average recoveries of intra- and inter-day experiment ranged from 82.0 to 105.2% and 81.7 to 102.8%, respectively. The repeatability and reproducibility for intra- and inter-day measurements expressed as a relative standard deviation was less than 8.7% and 7.4%, respectively. CONCLUSION: Established analytical method for ECZ residue in ACs was applicable to the nation-wide pesticide residues monitoring program with the acceptable level of sensitivity, repeatability and reproducibility.

Development of a Pulse Wave Velocity Measurement System and Assessment of the System Reproducibility for the Diagnosis of Arteriosclerosis (동맥경화 진단을 위한 맥파전달속도 측정시스템 개발 및 재현성 평가)

  • Lee, Nak-B.;Im, Jae-J.;Park, Young-B.;Jeon, Young-J.
    • The Journal of the Society of Korean Medicine Diagnostics
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    • v.9 no.1
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    • pp.112-124
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    • 2005
  • Background: PWV is determined by dividing the distance by the time taken for the pulses traveling between two measuring sites, used as a marker of arterial stiffness and an important indicator for cardiovascular disease. Methods: A PWV measurement system, which offers a non-invasive, simple method of measurement, and simultaneous recording of six signlas(ECG, PCG and four pulse waves from carotid, femoral, radial and dorsalis pedis arteries) was developed. Seventeen healthy subjects with a mean age of 33 years(22 to 52) without any cardiovascular disease were participated for the experiment. Two observers(A and B) performed two consecutive measurements from the same subject in a random order. For the evaluation of stability and accuracy of the PWV measurement system, reproducibility of PWV from between-observer were also evaluated. Results: PWV $values(Mean{\pm}SD)$ measured by A were $7.07{\pm}1.48m/s$, $8.43{\pm}1.14m/s$ , $8.09{\pm}0.98m/s$ for aorta, arm, and leg, respectively. The values obtained from B were $6.76{\pm}1.00m/s$, $7.97{\pm}0.80m/s$, and $7.97{\pm}0.72m/s$ for aorta, arm, and leg, respectively. Between-observer $differences(mean{\pm}SEM)$ from the aorta, arm and leg were $0.14{\pm}0.15m/s$, $0.18{\pm}0.10m/s$ and $0.07{\pm}0.10m/s$. Reproducibility coefficients(2SD) from the aorta, arm, and leg were 0.62m/s, 0.84m/s and 0.86m/s. Correlation coefficients were significantly higher in aortic PWV, 0.93, compared to the coefficients for arm and leg. Coefficient of variance which reflects the reproducibility of the system ranged from $4.4{\sim}5.8%$ in all regional PWV. , Conclusion: Reproducibility of PWV in the study shows that the developed system has reliable and reproducible characteristics. The PWV measurement system used for the study offers comfortable and simple operation and provides accurate analysis and results with high reproducibility. Results of the PWV measurement system could contribute to various clinical applications in the future.

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Evaluation of RPL Glass Dosimeter Characteristics and Uncertainty Evaluation of Reading Correction Factors (유리선량계 특성평가 및 판독 보정인자에 대한 불확도 평가)

  • Seong-Yun Mok;Yeong-Rok Kang;Hyo-Jin Kim;Yong-Uk Kye;Hyun An
    • Journal of radiological science and technology
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    • v.46 no.3
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    • pp.219-229
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    • 2023
  • In this study, basic characteristics such as reproducibility, linearity, and directionality of RPL glass dosimeters were evaluated to improve the reliability of dose evaluation through RPL glass dosimeters, and uncertainty elements such as sensitivity by glass element and magazine slot sensitivity were evaluated. Using a mathematical model to calibrate the measured values of the RPL glass dosimeter, the measurement uncertainty was calculated assuming an example. As a result of the characteristic evaluation, the RPL glass dosimeter showed excellent performance with a standard deviation of ±1% (1 SD) for the reproducibility of the reading process, a coefficient of determination for linearity of 0.99997. And the read-out of the RPL glass dosimeter are affected by the circular rotation direction of the glass dosimeter during irradiation, fading according to the period after irradiation, the number of laser pulses of the reader, and response degradation due to repeated reading, it is judged that measurement uncertainty can be reduced by irradiation and reading in consideration of these factors. In addition, it was confirmed that the dose should be determined by calculating the correction factors for the sensitivity of each element and, the sensitivity of each reading magazine slot. It is believed that the reliability of dosimetry using glass dosimeters can be improved by using a mathematical model for correction of glass dosimeter readings and calculating measurement uncertainty.

Performance Characteristic of the β-Human Chorionic Gonadotropin Assay on the Access 2 for Its Use in Doping Control

  • Kang, Min-Jung;Lee, Hye-Im;Shin, Sang-Mi;Yoo, Hye-Hyun;Kwon, Oh-Seung;Jin, Chang-Bae;Chung, Bong-Chul
    • Bulletin of the Korean Chemical Society
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    • v.31 no.10
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    • pp.2889-2892
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    • 2010
  • The objective of this study was to validate performance characteristics of the Access 2 (Beckman coulter) system for hCG assays for use as a confirmation test for doping control. The Access 2 assay was linear up to 500 IU/L. The correlation coefficient was higher than 0.999, and the sensitivity of the linearity was 0.82. There were no false positive or false negative cases. LOD was 0.59 IU/L. The method was robust when performed by different people. Repeatability and reproducibility were below 7%. We compared reproducibility and recoveries of Access 2 and Elecsys 2010. Access 2 demonstrated higher reproducibility than Elecsys 2010. Recoveries (accuracy) of Access 2 were between 85 and 105%. Recoveries for Elecsys 2010 were between 91 and 104%.

Future Climate Change Impact Assessment of Chungju Dam Inflow Considering Selection of GCMs and Downscaling Technique (GCM 및 상세화 기법 선정을 고려한 충주댐 유입량 기후변화 영향 평가)

  • Kim, Chul Gyum;Park, Jihoon;Cho, Jaepil
    • Journal of Climate Change Research
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    • v.9 no.1
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    • pp.47-58
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    • 2018
  • In this study, we evaluated the uncertainty in the process of selecting GCM and downscaling method for assessing the impact of climate change, and influence of user-centered climate change information on reproducibility of Chungju Dam inflow was analyzed. First, we selected the top 16 GCMs through the evaluation of spatio-temporal reproducibility of 29 raw GCMs using 30-year average of 10-day precipitation without any bias-correction. The climate extreme indices including annual total precipitation and annual maximum 1-day precipitation were selected as the relevant indices to the dam inflow. The Simple Quantile Mapping (SQM) downscaling method was selected through the evaluation of reproducibility of selected indices and spatial correlation among weather stations. SWAT simulation results for the past 30 years period by considering limitations in weather input showed the satisfactory results with monthly model efficiency of 0.92. The error in average dam inflow according to selection of GCMs and downscaling method showed the bests result when 16 GCMs selected raw GCM analysi were used. It was found that selection of downscaling method rather than selection of GCM is more is important in overall uncertainties. The average inflow for the future period increased in all RCP scenarios as time goes on from near-future to far-future periods. Also, it was predicted that the inflow volume will be higher in the RCP 8.5 scenario than in the RCP 4.5 scenario in all future periods. Maximum daily inflow, which is important for flood control, showed a high changing rate more than twice as much as the average inflow amount. It is also important to understand the seasonal fluctuation of the inflow for the dam management purpose. Both average inflow and maximum inflow showed a tendency to increase mainly in July and August during near-future period while average and maximum inflows increased through the whole period of months in both mid-future and far-future periods.

Usability Evaluation of Foot Pedal Switch in X-ray Radiography System (진단용 엑스선 촬영장치에서 발판 스위치의 유용성 평가)

  • Kwon, Hyeokjin;Jung, Hongmoon;Jung, Jaeeun;Jung, Kyunghwan;Won, Doyeon
    • Journal of the Korean Society of Radiology
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    • v.12 no.5
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    • pp.651-658
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    • 2018
  • A foot pedal switch in the diagnosis x-ray radiography system has been researched to improve radiologic technologist works and patient satisfaction. The switch has been installed in the diagnosis x-ray radiography system used in domestic clinics. Quantitative evaluation has been conducted by measuring the exposure dose reproducibility test, tube voltage, mAs, and percentage average error. Qualitative evaluation has been conducted by analysis of the radiologic technologists questionnaire. In the quantitative evaluation for the use of the foot pedal switch, the coefficient of variation was less than 0.05 in the exposure dose reproducibility test. In the mAs test, percentage average error of ${\pm}20%$ was measured. There was no problem raised since it meets the all inspection standards of the diagnosis x-ray generator. In the qualitative evaluation, most of the opinions are that it has a clinical value for the foot pedal switch in the diagnosis x-ray radiography system. Therefore, developing the foot pedal switch for the diagnosis x-ray radiography system can improve effectively the rapidity and accuracy of the radiologic technologist work. In addition, it is effective in decreasing the x-ray exposure of patients and increasing satisfaction for the medical service due to reduction of retaking x-ray.

Evaluation of Applicability of Perovskite Dosimeter based on CsPbBr3 Material to Quality Assurance in Radiation Therapy (CsPbBr3을 기반으로 한 Perovskite 선량계의 방사선치료 Quality Assurance에 대한 적용가능성 평가)

  • Yang, Seung-Woo;Park, Sung-Kwang
    • Journal of the Korean Society of Radiology
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    • v.16 no.3
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    • pp.211-216
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    • 2022
  • In radiation therapy, accurate Quality Assurance (QA) is required to irradiate tumor tissue while minimizing damage to normal tissue. Therefore, a dosimeter that can accurately measure radiation is needed. The purpose of this study is to develop a highly efficient radiation dosimeter with high sensitivity by applying a particle in binder method that can reduce manufacturing costs and simplify processes to perovskite materials that are cheaper and simpler to manufacture. By evaluating the response characteristics to high-energy photon, the applicability of QA dosimeter to radiation therapy was evaluated. As a result of reproducibility evaluation, RSD at 6 MV energy was presented as 1.178% and 15 MV energy was presented as 1.141%. As a result of linearity evaluation according to linear regression analysis, R2 values of 0.9999 were presented under each condition of 6 MV and 15 MV energy. It was found that the CsPbBr3 dosimeter manufactured based on the results of reproducibility and linearity evaluation is highly applicable as a QA dosimeter in the field of therapeutic radiation. The CsPbBr3 dosimeter manufactured in this study presented more than the standard performance in the evaluation of reproducibility and linearity, and it can be used as a radiotherapy QA dosimeter through improvement.