• Title/Summary/Keyword: precise reproducibility

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A Study on Method for Improving Reproducibility in the Ultrasonic Measurement of Bone Mineral Density (초음파 골밀도 측정에서 재현성 향상 방법에 관한 연구)

  • Shin, Jeong-Sik;Ahn, Jung-Hwan;Kim, Hwa-Young;Kim, Hyung-Jun;Han, Seung-Moo
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.29 no.10 s.241
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    • pp.1430-1437
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    • 2005
  • It is very important to achieve a high reproducibility in the ultrasonic measurement of bone mineral density. In this study, we examined number of sampling waveform, control of temperature, diameter of region of interest as factors to improve reproducibility. We decided the optimal number of waveforms to be converted to frequency domain as period of 1. We have minimized the effects of variable temperature and constrained generation of micro bubble by keeping temperature within a range of $32\pm0.5^{\circ}C$ with a precise temperature controlling algorithm. We also found the optimal diameter of region of interest to be 13mm. In this paper, we demonstrated the improved reproducibility by controlling various factors affecting the ultrasonic measurement of bone mineral density.

Measurement Uncertainty Estimation of Injection Temperature in Injection Molding Machine (사출성형기의 사출온도에 대한 측정 불확도 추정)

  • Jung, Hyun-Suk;Yoo, Joong-Hak
    • Journal of the Korean Society of Manufacturing Technology Engineers
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    • v.22 no.1
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    • pp.145-149
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    • 2013
  • The performance of injection molding machine's control system, such as reproducibility, repeatability, etc, is widely studied nowadays. Since screw stroke, injection cylinder body pressure and barrel temperature are the most important terms of injection unit, interval linearity and repeatability to each parameter are analyzed here. Barrel temperature is analyzed according to the repeatability of the thermocouple at $150^{\circ}C$, $210^{\circ}C$, $300^{\circ}C$ using a precise oven. The result temperature is within ${\pm}0.5^{\circ}C$ Through the reliability evaluation of the most important terms of injection unit, the method of evaluating the linearity and repeatability is proposed and verified.

Design of the Calibration System for Determining the Sensitivity of Ultrasonic Transducer (초음파 변환기의 감도 교정 시스템 구성)

  • 사공성대;조문재;최봉열
    • Journal of Institute of Control, Robotics and Systems
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    • v.5 no.2
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    • pp.200-207
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    • 1999
  • In this paper, a precise sensitivity measurement system of ultrasonic transducer in the frequency range from 1 MHz to 15 MHz, which can implement the reciprocity principle is constructed. All of the elements of this system such as the ultrasonic preamplifier, ultrasonic absorber, water tank, water degassing system, and four-axes translator and reflector are constructed. For the performance evaluation of the calibration system, a standard hydrophone precisely calibrated from PTB(Physikalisch Technische Bundesanstalt) in Germany are used. And the system parameters which affected the evaluation of the measurement accuracy and the reproducibility in various measuring conditions are considered. The measurement uncertainty of the calibration system is estimated within $\pm$ 2.0㏈.

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A Study on the Development and Precise Performance Test of a Screw Type Flowmeter (스크류 유량계의 개발 및 정밀 성능평가에 관한 연구)

  • Hwang, Jong-Dae;Oh, Ji-Young;Jung, Yoon-Gyo;Lee, Sang-Ryul
    • Journal of the Korean Society for Precision Engineering
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    • v.26 no.5
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    • pp.87-95
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    • 2009
  • This research introduces the efficient modeling and manufacturing method using reverse engineering combined with rotational simulation of a pair of screw and mill-turn machining realized a proposed NC program. Because previously developed model had insufficient flow measuring accuracy, we considered that matter in the aspect of method of modeling and performance test. For that reason we modified the modeling which could minimize a gab between male and female screw, and developed precise tester which consists of constant tank, flowmeter and load cell, etc., and then conducted the test for defining characteristic and accuracy of flowmeter and repeated same test 5-times. Consequently we could obtain satisfied measuring accuracy and reproducibility indicated in the catalog of master model. Hence we give our conclusion as to the validity of developing accurate screw type flowmeter using the proposed process such as reverse engineering, mill-turn machining and precise performance test.

Isocenter Reproducibility with Mask Fixation System in Stereotactic Radiosurgery (정위 마스크 시스템을 사용한 방사선수술시 회전중심점의 재현성)

  • 이동준;손문준;이기택;최찬영;황금철;황충진
    • Progress in Medical Physics
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    • v.13 no.3
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    • pp.135-138
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    • 2002
  • Fractionated stereotactic radiosurguy (FSRS) requires precise and reproducible patient set up. For these reasons non-invasive mask fixation methods have been used in Linac based FSRS. In this study, we measured and assessed the isocenter reproducibility using a commercial head mask fixation system based on thermoplastic materials. For the verification and the measurement of isocenter deviation a special acrylic brain phantom was designed. The designed phantom has 22 vertical rods and each rod has different lengths. At the end of the 8 rods, the monochromic film is attached and irradiated due to planned target position. Deviations of isocenter were measured separately for each direction. The mean deviation showed 0.4 mm in longitudinal direction, 0.1 mm in the lateral direction, 0.1 mm in the anterior-posterior direction of the treatment couch. The data demonstrates the high accuracy and reproducibility. This study reinforces previous literature published.

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A study on medium-low pressure gauge for domestic production (중.저기압 압력계의 국산화에 관한 연구)

  • 백용현
    • 전기의세계
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    • v.29 no.8
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    • pp.519-523
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    • 1980
  • The traditional mechanical manometer is improved to develop more convenient and precise manometer in continuous measurement of the gas pressure in medium-low vacuum range (1x10$^{-1}$ -10 Torr.) Glass (solid) is used as a detector material of the improved manometer. Using the strain gauge adhered to thin glass board, mechanical strain corresponding to variation of pressure in measurement system is converted into quantity of electricity, and the quantity of electricity is amplified. Experiments have also shown that the improved manometer have more advantages in reproducibility, measured sensibility, and responsible velocity than taditional one.

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Comparative study of two CAD software programs on consistency between custom abutment design and the output (두 가지 CAD software의 맞춤형 지대주 디자인과 출력물 일치도 비교)

  • Lim, Hyun-Mi;Lee, Kyu-Bok;Lee, Wan-Sun;Son, KeunBaDa
    • Journal of Dental Rehabilitation and Applied Science
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    • v.34 no.3
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    • pp.157-166
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    • 2018
  • Purpose: This study was aimed to compare the consistency between the custom abutment design and the output in two CAD software programs. Materials and Methods: Customized abutments were designed by using 3Shape Dental System CAD software and Delta9 CAD software on a plaster model with implants (CRM STL file). After milling of the designed abutments, the abutments were scanned with a contact method scanner (Test STL file). We overlaid the Test STL file with each CRM STL file by using inspection software, and then compared the milling reproducibility by measuring the output error of the specimens from each CAD software program. Results: The Delta9 showed better milling reproducibility than 3Shape when comparing the milling errors obtained with a full scan of all specimens (P < .05) and also when comparing the axial wall region specifically according to the axial angle. With 0.9 mm marginal radius, the Delta9 showed better consistency between the design and the output than 3Shape (P < .05). While, anti-rotation form had no significant difference in error between the two systems. When cumulative errors were compared, the Delta9 showed better milling reproducibility in almost cases (P < .05). Conclusion: Delta9 showed a significantly smaller error for most of the abutment design options. This means that it is possible to facilitate generation of printouts with reliable reproducibility and high precision with respect to the planned design.

Adaptation and validation of body maps for musculoskeletal pain location in patients with severe obesity

  • Mendonca, Carolina Rodrigues;Noll, Matias;Silveira, Erika Aparecida
    • The Korean Journal of Pain
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    • v.31 no.4
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    • pp.268-276
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    • 2018
  • Background: Although a variety of instruments implement body maps for the precise identification of pain symptoms, no instrument has been validated for use in people with obesity. This study reports the adaptation and validation of body maps for musculoskeletal pain location in people with obesity. Methods: Nine key anatomical regions were highlighted based on the original images of the Nordic Musculoskeletal Questionnaire body maps. Adult silhouettes were generated from photographs of men and women with obesity. The body dimensions were adjusted to take into account the different body fat distribution patterns of people with obesity. The validity of the images was assessed by 12 experts. Subsequently, a data collection stage was performed with 58 patients with severe obesity from both sexes. The reproducibility of the images was tested by comparison with the original images. Results: The results of the validation pilot study indicated that the adapted images facilitated the location of musculoskeletal pain in men and women with obesity. The reproducibility of the original and adapted versions of the body maps indicated good agreement for pain over the last 12 months and 7 days (80% vs. 79.7%). Pain scores in the last 12 months indicated good and high sensitivity and specificity for all body areas (60.9% vs. 89.1%). Considering pain in the last 7 days, high sensitivity and specificity for all areas of the body (85.1% vs. 70.1%). Conclusions: The body maps developed in this study are reliable and valid to identify the location of pain in people with obesity.

A study on the error of tooth size measurements (치아크기 계측오차에 관한 연구)

  • Sim, Eun-Ju;Hwang, Hyeon-Shik;Moon, Jai-Dong
    • The korean journal of orthodontics
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    • v.29 no.4 s.75
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    • pp.491-501
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    • 1999
  • Precise and accurate measuring of tooth size is essential procedure in orthodontic diagnosis. The purpose of this study was to evaluate the reproducibility and accuracy of tooth size measurements with regard to tooth and investigator. Five investigators measured the size of one side of teeth, from central incisor to first molar, on 20 sets of casts that show a moderate degree of crowding. Mesio-distal width was measured with digital vernier calipers in each tooth and this procedure was repeated three times at two weeks interval. To obtain a standard measurement for each tooth, dental casts were cut into individual tooth, and its width was measured with micrometer. The difference between the measurement from dental cast and the standard measurement was defined as the measurement error. Through various statistical analyses, following results were obtained. 1. The reproducibility did not show significant differences with regard to tooth or investigator. 2. The measurement error showed some difference with regard to tooth and investigator. 3. The magnitude of the measurement error showed increasing tendency from anterior to posterior teeth with maximum value in the first molar. 4. While the measurements obtained on study casts generally showed smaller number compared to standard measurements, the direction of the difference showed variability according to tooth or investigator. 5. The measurement errors did not show significant correlations with the degree of crowding. The results of the present study indicate that the possibility of tooth size measurement error should be taken into consideration when diagnosing an orthodontic case.

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Clinical validation of ImmuneCheck IgE for the rapid detection of serum total IgE (총 IgE의 신속한 정량 측정을 위한 ImmuneCheck IgE의 임상적 유용성)

  • Lee, Shinhaeng;Choi, Jinyoung;Choe, Eunju;Lee, Sang Chul;Park, Kyung Hee;Lee, Jae-Hyun;Park, Jung-Won
    • Allergy, Asthma & Respiratory Disease
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    • v.6 no.6
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    • pp.310-314
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    • 2018
  • Purpose: Conventional serum IgE assay was costly, required the skills of expert, and relied heavily on expensive equipment. Quantitative measurement of total IgE using Point of Care Test (POCT) device can be the solution for these limitations. This study evaluated and validated the reproducibility of ImmuneCheck IgE. Methods: This study included 120 patients of allergic diseases such as allergic rhinitis, asthma, drug allergy, food allergy, atopic dermatitis, or anaphylaxis. The reliability of POCT ImmuneCheck IgE was evaluated by comparing results from the naked eye and from the Q-Reader. Intratest reproducibility and intertest correlation were analyzed using intraclass correlation coefficient (ICC). Results: Of the 120 enrolled patients, 51 were males and 69 were females. The ages ranged from 19 to 84 years, with an average age of 51.5 years. The concentration of serum total IgE measured by Phadia ImmunoCAP IgE ranged from 5.95 to 5,000 IU/mL. ICC for Intratest reproducibility of ImmuneCheck IgE by naked eye and by Q-Reader were 0.991 (P< 0.001) and 0.989 (P< 0.001), respectively. In addition, intertest correlation between ImmuneCheck IgE and Phadia ImmunoCAP IgE results of naked eye and Q-Reader were 0.968 (P< 0.001) and 0.948 (P< 0.001), respectively. Conclusion: The ImmuneCheck IgE was reproducible and highly correlated with conventional Phadia ImmunoCAP IgE assay. This result suggests that ImmuneCheck IgE can be a useful tool for rapid and precise detection of total IgE.