• Title/Summary/Keyword: diagnostic error

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Artifacts in Digital Radiography (디지털 방사선 시스템에서 발생하는 Artifact)

  • Min, Jung-Whan;Kim, Jung-Min;Jeong, Hoi-Woun
    • Journal of radiological science and technology
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    • v.38 no.4
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    • pp.375-381
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    • 2015
  • Digital Radiography is a big part of diagnostic radiology. Because uncorrected digital radiography image supported false effect of Patient's health care. We must be manage the correct digital radiography image. Thus, the artifact images can have effect to make a wrong diagnosis. We report types of occurrence by analyzing the artifacts that occurs in digital radiography system. We had collected the artifacts occurred in digital radiography system of general hospital from 2007 to 2014. The collected data had analyzed and then had categorize as the occurred causes. The artifacts could be categorized by hardware artifacts, software artifacts, operating errors, system artifacts, and others. Hardware artifact from a Ghost artifact that is caused by lag effect occurred most frequently. The others cases are the artifacts caused by RF noise and foreign body in equipments. Software artifacts are many different types of reasons. The uncorrected processing artifacts and the image processing error artifacts occurred most frequently. Exposure data recognize (EDR) error artifacts, the processing error of commissural line, and etc., the software artifacts were caused by various reasons. Operating artifacts were caused when the user didn't have the full understanding of the digital medical image system. System artifacts had appeared the error due to DICOM header information and the compression algorithm. The obvious artifacts should be re-examined, and it could result in increasing the exposure dose of the patient. The unclear artifact leads to a wrong diagnosis and added examination. The ability to correctly determine artifact are required. We have to reduce the artifact occurrences by understanding its characteristic and providing sustainable education as well as the maintenance of the equipments.

An Efficient Correction Process of CT-Simulator Couch with Current Diagnostic CT Scanners (진단용 CT-모의치료기 테이블의 효율적인 교정 방법)

  • Goo, Eun-Hoe;Lee, Jae-Seung;Cho, Jung-Keun;Moon, Seong-Kwon
    • The Journal of the Korea Contents Association
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    • v.9 no.11
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    • pp.254-261
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    • 2009
  • This study suggested that the table of CT-simulator and the laser alignment system using diagnostic CT scanner have an efficient method for improvement in alignment between the planned target center of traverse image with CT scanner. It was conducted on the daily QA when presented in the AAPM TG66 with correcting the laser alignment system using geometric trigonometric functions and investigated the effectiveness of correction methods as compared with those before and after correction. Before correction error was 3.82mm between the planned target center of image, the table longitudinal axis was twisted with 0.436o. The laser alignment system using geometric trigonometric functions in after correction was satisfied with tolerance limits of ${\pm}2mm$ when occurred about 0.7mm in errors between the planned target center. The table correction to satisfy the geometric accuracy is very inefficient over against the time and economic loss as well as technical limits in the case of application as only radiation therapy associated with CT-simulator with diagnostic CT scanner in use. But, the method which corrects the laser alignment system is economic and relatively simple with possibility of getting well geometric accuracy and we suppose that it is efficient method for applying in the clinic.

The effects of Jajun-maum-dom-movement program on the attention and hyperactivity of middle school students (자전 동작이 중학생의 주의력 및 행동에 미치는 영향)

  • Kim, Se-Won;Jung, Young-Su;Chu, Key-One;Kim, Geun-Woo;Kim, Seung-Hyeon;Ko, Byung-Soo
    • Journal of Oriental Neuropsychiatry
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    • v.21 no.4
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    • pp.79-97
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    • 2010
  • Objectives : The objective of this study is to investigate the effects of Jajun-maum-dom-movement program on the attention and hyperactivity of middle school students, Methods: Jajun-maum-dom-movement program was applied to 14 middle school students for 8 weeks, To measure the improvement of attention and decrease of hyperactivity, these tests were used - ADHD Diagnostic System(hereinafter ADS), Parent's Abbreviated Conners Rating Scale(hereinafter ACRS), Teacher's Korean ADHD Rating Scale(hereinafter K-ARS). For each variable in the 3 test methods, the results of before and after program were measured and then, the results were assessed by paired t-test, Interrelations between the resulted values of 10 variables were analyzed in these three groups: scores before program, scores after program, and change in scores before and after program, Among 10 variables, for variable showing significant difference by t-test, it was assessed by ANCOVA whether change in scores before and after program is affected by the grade and gender. Results: As for the changed score between before-the-program and after-the-program, in the ADS test, it was found that there is a significant effect in the "commission error" which is one of the indices showing the degree of hyperactivity, and "sensitivity(d')" which is one of the indices showing attention, and it was found that there is a significant effect in ACRS and K -ARSC total), Among the correlations of the 4 variables, "ACRS" and "K-ARSC total) ", which show the comprecessive criteria, have the positive correlation of significance in before-the-program, after-the-program and the changed score between before-the-program and after-the-program, However, there was no specific correlations among sub-variables about attention or hyperactivity, and in all of 4 variables, there was no significant degree of change according to grade or gender. Conclusions : As the results of assessment by ADHD Diagnostic System, Parent's Abbreviated Conners Rating Scale, Teacher's Korean ADHD Rating Scale to study the effects of Jajun-maum-dom-movement program on attention and hyperactivity, it is known that the program is helpful for improvement of attention and decrease of hyperactivity for the participated students.

Estimation of Compressive Strength of Reinforced Concrete Vertical and Horizontal Members Using Ultrasonic Pulse Velocity Method (초음파속도법을 이용한 철근콘크리트 수직 및 수평부재의 압축강도 추정)

  • Hong, Seonguk;Lee, Yongtaeg;Kim, Seunghun;Kim, Jonghyun
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.22 no.6
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    • pp.197-205
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    • 2018
  • Recently, remodeling is increasing due to aging of buildings. Therefore, the importance of quality control of structures has been raised, and interest in safety diagnosis and evaluation of structures has been increasing. In order to accurately diagnose old buildings, a diagnostic evaluation technique is needed to evaluate the defects of structures in advance. In addition, as the safety diagnostic criteria for reconstruction are improved and the weight of structural safety is increased, researches on safety diagnosis techniques of structures that are faster and more reliable are needed. In this study, we tried to estimate the compressive strength by examining the correlation between ultrasonic pulse velocity and compressive strength of a 1 story structure consisting of vertical and horizontal members of reinforced concrete using ultrasonic pulse velocity method, which is one of the nondestructive testing methods. The purpose of this study is to examine the applicability in the field. As a result, the estimated average error rate of the compressive strength of the structure using the ultrasonic pulse velocity method was 28.7%, which confirmed the applicability in the field. However, in order to increase the accuracy of the estimation, the necessity of the reliable diagnostic method using the composite nondestructive testing method was confirmed.

Somatic cell counts determination in cow milk by near infrared spectroscopy: A new diagnostic tool

  • Tsenkova, R.;Atanassova, S.;Kawano, S.;Toyoda, K.
    • Proceedings of the Korean Society of Near Infrared Spectroscopy Conference
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    • 2001.06a
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    • pp.4104-4104
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    • 2001
  • Milk somatic cell count (SCC) is a recognized indicator of cow health and milk quality. The potential of near infrared (NIR) spectroscopy in the region from 1100 to 2500nm to measure SCC content of cow milk was investigated. A total of 196 milk samples from 7 Holstein cows were collected for 28 days, consecutively, and analyzed for fat, protein, lactose and SCC. Three of the cows were healthy, and the rest had mastitis periods during the experiment. NIR transflectance milk spectra were obtained by the InfraAlyzer 500 spectrophotometer in a wavelength range from 1100 to 2500 nm. The calibration for logSCC was performed using partial least square (PLS) regression and different spectral data pretreatment. The best accuracy of determination was found for equation, obtained using smoothed absorbance data and 10 PLS factors. The standard error of calibration was 0.361, calibration coefficient of multiple correlation 0.868, standard error of prediction for independent validation set of samples 0.382, correlation coefficient 0.854 and the variation coefficient 7.63%. The accuracy of logSCC determination by NIR spectroscopy would allow health screening of cows, and differentiation between healthy and mastitic milk samples. When the spectral information was studied it has been found that SCC determination by NIR milk spectra was indirect and based on the related changes in milk composition. In the case of mastitis, when the disease occurred, the most significant factors that simultaneously influenced milk spectra were alteration of milk proteins and changes in ionic concentration of milk.

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Usefulness of Sputum Cytology as a Diagnostic Tool of Lung Cancer (폐암 진단방법으로서 객담검사의 유용성)

  • Cho, Eun-Yoon;Park, Hee-Dae;Kim, Sun-Hee;Park, Woon-Sun;Chae, Seoung-Wan;Kim, Eo-Jin;Sohn, Jin-Hee
    • The Korean Journal of Cytopathology
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    • v.15 no.2
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    • pp.75-80
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    • 2004
  • To analyze the accuracy and usefulness of sputum cytology as a screening method, 103 cases of histologically proven lung cancer registered from 1998 to 2000 at Kangbuk Samsung Hospital were retrospectively examined. We reviewed the original cytologic and surgical diagnoses for the cases, and the cytology slides of all cytologically negative cases. The overall sensitivity of sputum cytology was 0.83 ; the sensitivity of prebronchoscopy sputum cytology for bronchogenic carcinoma was 0.87. Central tumor location (P=0.002), tumor size (>2.4 cm), (P=0.027) and the number of sputum samples $(\geq3)$ (P=0.001) were associated with a positive cytologic diagnosis. Of the 18 cytologically negative cases, 9 cases(38% of smears) were determined to be insufficient for diagnosis, due strictly to low cellularity and saliva. After a review of the cytology slides of cytologically negative cases, we identified several atypical clusters in one case of bronchioloalveolar carcinoma. This negativity was thus attributed to an interpretation error (1/18, 5.6%). Our results suggest that its sensitivity is more strongly related to the specimen adequacy and the times of sampling than to interpretation error. In terms of sensitivity, specificity, accessibility, cost, and morbidity associated with the screening tests, sputum cytology was found to be an accurate effective screening method for lung cancer.

The method of in-situ ASTR method diagnosing wall U-value in existing deteriorated houses - Analysis of influence of internal surface total heat transfer rate -

  • Kim, Seo-Hoon;Kim, Jong-Hun;Jeong, Hakgeun;Song, Kyoo-dong
    • KIEAE Journal
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    • v.17 no.4
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    • pp.41-48
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    • 2017
  • Purpose : Currently, 25% of the domestic energy consumption structure is used as building energy, and more than 18% of this energy is consumed in the residential. Accordingly, various efforts and policies that can save energy of the building is being performed. The various researchers are conducting research to diagnose the thermal performance of existing buildings. This study is to apply in the field of precision thermal insulation performance diagnostic method for thermal performance analysis of existing detached house in Seoul, Gangreung, Gyeongju, Pohang. And this paper is analyzed quantitatively measure the existing detached house energy performance. Method: Research methodology analyzed the thermal performance over the Heat Flow Meter method by applying the measurement process and method by applying the criteria of ISO 9869-1 & ASTR method. In this study, the surface heat transfer coefficient was calibrated by applying indoor surface heat transfer resistance with reference to ISO 6946 standard. The measurement error rate between the HFM diagnosis method and the ASTR diagnosis method was reduced and the measurement reliability was obtained through measurement method error verification. Result : As a result of the study, the thermal performance vulnerable parts of the building were quantitatively analyzed, and presented for methods which can be improved capable of efficient energy use buildings.

Coda Sounds Acquisition at Word Medial Position in Three and Four Year Old Children's Spontaneous Speech (자발화에 나타난 3-4세 아동의 어중종성 습득)

  • Woo, Hyekyeong;Kim, Soojin
    • Phonetics and Speech Sciences
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    • v.5 no.3
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    • pp.73-81
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    • 2013
  • Coda in the word-medial position plays an important role in acquisition of our speech. Accuracy of the coda in the word-medial position is important as a diagnostic indicator since it has a close relationship with degrees of disorder. Coda in the word-medial position only appears in condition of connecting two vowels and the sequence causes diverse phonological processes to happen. The coda in the word-medial position differs in production difficulty by the initial sound in the sequence. Accordingly, this study aims to examine the tendency of producing a coda in the word-medial position with consideration of an optional phonological process in spontaneous speech of three and four year old children. Data was collected from 24 children (four groups by age) without speech and language delay. The results of the study are as follows: 1) Sonorant coda in the word-medial position showed a high production frequency in manner of articulation, and alveolar in place of articulation. When the coda in the word-medial position is connected to an initial sound in the same place of articulation, it revealed a high frequency of production. 2) The coda in word-medial position followed by an initial alveolar stop revealed a high error rate. Error patterns showed regressive assimilation predominantly. 3) The order of difficulty that Children had producing codas in the word-medial position was $/k^{\neg}/$, $/p^{\neg}/$, /m/, /n/, /ŋ/ and /l/. Those results suggest that in targeting coda in the word-medial position for evaluation, we should consider optional phonological process as well as the following initial sound. Further studies would be necessary which codas in the word-medial position will be used for therapeutic purpose.

Forecasting the Seaborne Trade Volume using Intervention Multiplicative Seasonal ARIMA and Artificial Neural Network Model (개입 승법계절 ARIMA와 인공신경망모형을 이용한 해상운송 물동량의 예측)

  • Kim, Chang-Beom
    • Journal of Korea Port Economic Association
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    • v.31 no.1
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    • pp.69-84
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    • 2015
  • The purpose of this study is to forecast the seaborne trade volume during January 1994 to December 2014 using the multiplicative seasonal autoregressive integrated moving average (ARIMA) along with intervention factors and an artificial neural network (ANN) model. Diagnostic checks of the ARIMA model were conducted using the Ljung-Box Q and Jarque-Bera statistics. All types of ARIMA process satisfied the basic assumption of residuals. The ARIMA(2,1,0) $(1,0,1)_{12}$ model showed the lowest forecast error. In addition, the prediction error of the artificial neural network indicated a level of 5.9% on hidden layer 5, which suggests a relatively accurate forecasts. Furthermore, the ex-ante predicted values based on the ARIMA model and ANN model are presented. The result shows that the seaborne trade volume increases very slowly.

A Status Report on Dual Energy X-ray Absorptiometry Quality Control in Korea (이중에너지 방사선흡수 골밀도 장치의 품질관리 현황)

  • Kim, Jung-Su;Rho, Young-Hoon;Lee, In-Ju;Kim, Sung-Su;Kim, Kyoung-Ah;Kim, Jung-Min
    • Journal of radiological science and technology
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    • v.39 no.4
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    • pp.527-534
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    • 2016
  • Dual-energy X-ray absorptiometry (DEXA) is the most widely used technical instrument for evaluating bone mineral content (BMC) and density (BMD) in patients of all ages. In 2016, DEXA devices operating is 5617 in Korea. In this study we investigated the quality of management practices survey for DEXA equipment and we analyzed it. We got a survey response rate of 12.6%. Accurate bone densitometry test is used data for estimation a patient's risk of fracture. However, improper bone densitometry will increase the possibility of causing a false positive. Therefore. it is essential to use the proper aids accurate bone densitomenty to be performed, and the quality control of the device to reduce the error factor of the tester through the training to reduce error for the device and the attitude.