• Title/Summary/Keyword: diagnostic tool

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Measurement of Focal Spot Size of Heavy Loaded X-ray Tubes (X선관의 실효초점 측정에 관한 고찰)

  • Chang, Kwang-Hyun;Lim, Oh-Soo;Kim, Hyung-Kee;Song, Chang-Wook;Cheung, Kyung-Mo;Cheung, Hwan
    • Journal of radiological science and technology
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    • v.16 no.1
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    • pp.101-106
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    • 1993
  • In order to assure safety of both patient and operator, and to provide uniform quality radiographs, it is necessary to perform periodic calibration of diagnostic X-ray equipment. A basic parameter of diagnostic equipment's and its image sharpness is the size(and shape the energy distribution) of the focal spot as viewed along the central X-ray beam. This size determines the resolution possible with the equipment and also determines the heat characteristics of an anode. A fine focus tube gives high resolution but causes high local heating of target. In past, the pin-hole and star pattern image measurement for evaluation of resolution have been widely used, but it produced blurring and inaccuracy of image. So newly inverted Ug-meter has advantage in more convenient measurement method and less out-put bias than other image measurement. The authors intended to compare measured focal size between Ug-meter and focal spot test tool, changed state from setting to now of units.

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Application of Receiver Operating Characteristic (ROC) Curve for Evaluation of Diagnostic Test Performance (진단검사의 특성 평가를 위한 Receiver Operating Characteristic (ROC) 곡선의 활용)

  • Pak, Son-Il;Oh, Tae-Ho
    • Journal of Veterinary Clinics
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    • v.33 no.2
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    • pp.97-101
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    • 2016
  • In the field of clinical medicine, diagnostic accuracy studies refer to the degree of agreement between the index test and the reference standard for the discriminatory ability to identify a target disorder of interest in a patient. The receiver operating characteristic (ROC) curve offers a graphical display the trade-off between sensitivity and specificity at each cutoff for a diagnostic test and is useful in assigning the best cutoff for clinical use. In this end, the ROC curve analysis is a useful tool for estimating and comparing the accuracy of competing diagnostic tests. This paper reviews briefly the measures of diagnostic accuracy such as sensitivity, specificity, and area under the ROC curve (AUC) that is a summary measure for diagnostic accuracy across the spectrum of test results. In addition, the methods of creating an ROC curve in single diagnostic test with five-category discrete scale for disease classification from healthy individuals, meaningful interpretation of the AUC, and the applications of ROC methodology in clinical medicine to determine the optimal cutoff values have been discussed using a hypothetical example as an illustration.

Characteristics of Patients with Allergic Rhinitis through the Pattern Questionnaire Items (변증 설문지 문항을 통해 살펴 본 알레르기 비염 환자의 특성)

  • Son, Jae-Woong;Lee, Kyu-Jin;Jang, Bo-Hyeong;Jang, Soobin;Ko, Seong-Gyu;Choi, In-Hwa
    • Journal of Society of Preventive Korean Medicine
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    • v.18 no.3
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    • pp.81-90
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    • 2014
  • Objective : We performed a clinical study to investigate pattern characteristics in persistent allergic rhinitis depending on Korean Medicine pattern questionnaire items as a pattern identification diagnostic tool. Method : 32 patients with persistent allergic rhinitis were asked to interview with doctor of Korean Medicine and perform the 4 pattern questionnaires(Cold-Heat Pattern, Phlegm Pattern, Yin Deficiency pattern, bloodstasis pattern). Then, we analyzed the response rate of each pattern questionnaires. Results : After diagnosis of Korean Medicine Doctor's pattern identification, 17 individual items have higher response rate, 7 of 17 items have a common tendency in allergic rhinitis. The other 8 of 10 items belong to Lung qi deficiency cold and Lung-spleen qi deficiency group, these have higher tendency of deficiency. In bloodstasis pattern questionnaires, we don't decide the tendency of patients with allergic rhinitis. Conclusion : The result may provide that we don't use Korean Medicine pattern questionnaires as a major tool in the pattern identification of allergic rhinitis. Continuous studies are needed to develop the standardized pattern identification diagnostic tool.

A Study on the Development and Validation of Learning Status Diagnostic Tool (학습상황진단도구 개발 사례 연구 : K대학교를 중심으로)

  • Lee, Seong Ah
    • Journal of Christian Education in Korea
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    • v.64
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    • pp.409-444
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    • 2020
  • The purpose of this study is to develop and propose a tool for accurately diagnosing factors influencing academic activities in Christian University. The first, the evaluation area is composed of factors that influence the academic life of students. Then, by developing a tool to diagnose the status in that areas, it is intended to provide a basis for providing appropriate help for students to adjust to university life. This tool composed items through prior research and developed a draft of tool through Delphi research. The draft tool was verified for reliability and validity by analyzing the response values of 182 freshmen at K University. As a result of the analysis, the reliability showed high reliability of .869~.955 for each diagnosis area. In conclusion, through the results of EFA and CFA, a final diagnostic tool was developed and suggested.

New Diagnostic Tool for Far Lateral Lumbar Disc Herniation : The Clinical Usefulness of 3-Tesla Magnetic Resonance Myelography Comparing with the Discography CT

  • Kim, Duk-Gyu;Eun, Jong-Pil;Park, Jung-Soo
    • Journal of Korean Neurosurgical Society
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    • v.52 no.2
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    • pp.103-106
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    • 2012
  • Objective : To prospectively assess the diagnostic and clinical value of a new technique (3-tesla magnetic resonance myelography, 3T MRM) as compared to computed tomographic discography (disco-CT) in patients with far lateral disc herniation. Methods : We evaluated 3T MRM and disco-CT of 25 patients, whom we suspected of suffering from far lateral disc herniation. Using an assessment scale, 4 observers examined independently both 3T MRM and disco-CT images. We analyzed observer agreement and the accentuation of each image. Results : We found complete matching, and observer agreement, between high resolution images of 3T MRM and disco-CT for diagnosing far lateral disc herniation. Conclusion : We think noninvasive 3T MRM is an appropriate diagnostic tool for far lateral disc herniation as compared to disco-CT.

MODELING FOR PROBING THE PHYSICAL STATES OF HII REGIONS (전리수소 영역의 물리량 측정을 위한 방출선 모형연구)

  • Sung, Hyun-Il
    • Publications of The Korean Astronomical Society
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    • v.26 no.1
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    • pp.25-35
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    • 2011
  • A diagnostic tool has been proposed to convert the observed surface distribution of hydrogen recombination line intensities into the radial distributions of the electron temperature and the density in HII regions. The observed line intensity is given by an integral of the volume emission coefficient along the line of sight, which comprises the Abel type integral equation for the volume emission coefficient. As the emission coefficient at a position is determined by the temperature and density of electrons at the position, the local emission coefficient resulted from the solution of the Abel equation gives the radial distribution of the temperature and the density. A test has been done on the feasibility of our diagnostic approach to probing of HII regions. From model calculations of an HII region of pure hydrogen, we have theoretically generated the observed surface brightness of hydrogen recombination line intensities and analyzed them by our diagnostic tool. The resulting temperatures and densities are then compared with the model values. For this case of uniform density, errors in the derived density are not large at all the positions. For the electron temperature, however, the largest errors appear at the central part of the HII region. The errors in the derived temperature decrease with the radial distance, and become negligible in the outer part of the model HII region.

Novel Heptaplex PCR-Based Diagnostics for Enteric Fever Caused by Typhoidal Salmonella Serovars and Its Applicability in Clinical Blood Culture

  • Hyun-Joong Kim;Younsik Jung;Mi-Ju Kim;Hae-Yeong Kim
    • Journal of Microbiology and Biotechnology
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    • v.33 no.11
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    • pp.1457-1466
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    • 2023
  • Enteric fever is caused by typhoidal Salmonella serovars (Typhi, Paratyphi A, Paratyphi B, and Paratyphi C). Owing to the importance of Salmonella serovars in clinics and public hygiene, reliable diagnostics for typhoidal serovars are crucial. This study aimed to develop a novel diagnostic tool for typhoidal Salmonella serovars and evaluate the use of human blood for clinically diagnosing enteric fever. Five genes were selected to produce specific PCR results against typhoidal Salmonella serovars based on the genes of Salmonella Typhi. Heptaplex PCR, including genetic markers of generic Salmonella, Salmonella enterica subsp. enterica, and typhoidal Salmonella serovars, was developed. Typhoidal Salmonella heptaplex PCR using genomic DNAs from 200 Salmonella strains (112 serovars) provided specifically amplified PCR products for each typhoidal Salmonella serovar. These results suggest that heptaplex PCR can sufficiently discriminate between typhoidal and non-typhoidal Salmonella serovars. Heptaplex PCR was applied to Salmonella-spiked blood cultures directly and provided diagnostic results after 12- or 13.5-h blood culture. Additionally, it demonstrated diagnostic performance with colonies recovered from a 6-h blood culture. This study provides a reliable DNA-based tool for diagnosing typhoidal Salmonella serovars that may be useful in clinical microbiology and epidemiology.

A Bayesian Diagnostic for Influential Observations in LDA

  • Lim, Jae-Hak;Lee, Chong-Hyung;Cho, Byung-Yup
    • Journal of Korean Society for Quality Management
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    • v.28 no.1
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    • pp.119-131
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    • 2000
  • This paper suggests a new diagnostic measure for detecting influential observations in linear discriminant analysis (LDA). It is developed from a Bayesian point of view using a default Bayes factor obtained from the imaginary training sample methodology. The Bayes factor is taken as a criterion for testing homogeneity of covariance matrices in LDA model. It is noted that the effect of an observation over the criterion is fully explained by the diagnostic measure. We suggest a graphical method that can be taken as a tool for interpreting the diagnostic measure and detecting influential observations. Performance of the measure is examined through an illustrative example.

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A Bayesian Diagnostic Measure and Stopping Rule for Detecting Influential Observations in Discriminant Analysis

  • Kim, Myung-Cheol;Kim, Hea-Jung
    • Journal of the Korean Statistical Society
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    • v.29 no.3
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    • pp.337-350
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    • 2000
  • This paper suggests a new diagnostic measure and a stopping rule for detecting influential observations in multiple discriminant analysis (MDA). It is developed from a Bayesian point of view using a default Bayes factor obtained from the fractional Bayes factor methodology. The Bayes factor is taken as a discriminatory information in MDA. It is shown that the effect of an observation over the discriminatory information is fully explained by the diagnostic measure. Based on the measure, we suggest a stopping rule for detecting influential observations in a given training sample. As a tool for interpreting the measure a graphical method is sued. Performance of the method is used. Performance of the method is examined through two illustrative examples.

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Chromosomal Microarray Testing in 42 Korean Patients with Unexplained Developmental Delay, Intellectual Disability, Autism Spectrum Disorders, and Multiple Congenital Anomalies

  • Lee, Sun Ho;Song, Wung Joo
    • Genomics & Informatics
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    • v.15 no.3
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    • pp.82-86
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    • 2017
  • Chromosomal microarray (CMA) is a high-resolution, high-throughput method of identifying submicroscopic genomic copy number variations (CNVs). CMA has been established as the first-line diagnostic test for individuals with developmental delay (DD), intellectual disability (ID), autism spectrum disorders (ASDs), and multiple congenital anomalies (MCAs). CMA analysis was performed in 42 Korean patients who had been diagnosed with unexplained DD, ID, ASDs, and MCAs. Clinically relevant CNVs were discovered in 28 patients. Variants of unknown significance were detected in 13 patients. The diagnostic yield was high (66.7%). CMA is a superior diagnostic tool compared with conventional karyotyping and fluorescent in situ hybridization.