• 제목/요약/키워드: diagnostic tests

검색결과 807건 처리시간 0.027초

식도 외 역류의 도그마 (Dogma of Extraesophaghgeal Reflux)

  • 박일석
    • 대한후두음성언어의학회지
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    • 제27권2호
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    • pp.78-83
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    • 2016
  • Laryngopharyngeal reflux (LPR) disease is an extraoesophageal variant of gastro-esophageal reflux disease that can affect the larynx and pharynx. LPR is associated with symptoms of laryngeal irritation such as throat clearing, coughing, and hoarseness. The main diagnostic methods currently used are laryngoscopy and pH monitoring. The most common laryngoscopic signs are redness and swelling of the throat. However, these findings are not specific of LPR and may be related to other causes or can even be found in healthy individuals. Furthermore, the role of pH monitoring in the diagnosis of LPR is controversial. A therapeutic trial with proton pump inhibitors (PPIs) has been suggested to be cost-effective and useful for the diagnosis of LPR. However, the recommendations of PPI therapy for patients with a suspicion of LPR are based on the results of uncontrolled studies, and high placebo response rates suggest a much more complex and multifactorial pathophysiology of LPR than simple acid reflux. Laryngoscopy and pH monitoring have failed as reliable tests for the diagnosis of LPR. Empirical therapy with PPIs is widely accepted as a diagnostic test and for the treatment of LPR. However, further research is needed to develop a definitive diagnostic test for LPR.

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적외선, 생물광자 및 GDV 측정의 한의학적 비교 소개 (Comparative Introduction of IR, Biophoton, and GDV on the Application of Korean Medicine Based on Their Recent Progress)

  • 이승호;이혜정
    • Korean Journal of Acupuncture
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    • 제27권2호
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    • pp.159-181
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    • 2010
  • Objectives : The purpose of this study is to introduce and examine the possibilities of infrared (IR) imaging, biophoton detection and gas discharge visualization(GDV) as diagnostic tools in Korean Medicine. Methods : To review the basic mechanism and measurement methods of three modalities, concepts in physics were introduced. Physical backgrounds of IR, biophoton and GDV were briefly explained based on recent research papers. Simple electronics was employed for relevant detectors. In order to find the relation between Korean Medicine and these methods, papers on their applications were reviewed. Opinions from the experts on each modality were obtained from their papers and private communications. Results and Conclusions : IR imaging has been used as an auxiliary diagnostic tool but there are some rooms for the improvement for clinical applications. Experimental confirmation of the meridian activation by a moxa cigar is necessary for its verification. Biophoton is not correlated with human skin temperature but it has a circadian rhythm. Biophoton and GDV have a negligible relation if any. Therefore there are no correlations among three modalities in terms of basic mechanisms. But their clinical relations are yet to be scrutinized. Biophoton and GDV need more rigorous clinical tests before they can be used as diagnostic tools.

Graph neural network based multiple accident diagnosis in nuclear power plants: Data optimization to represent the system configuration

  • Chae, Young Ho;Lee, Chanyoung;Han, Sang Min;Seong, Poong Hyun
    • Nuclear Engineering and Technology
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    • 제54권8호
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    • pp.2859-2870
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    • 2022
  • Because nuclear power plants (NPPs) are safety-critical infrastructure, it is essential to increase their safety and minimize risk. To reduce human error and support decision-making by operators, several artificial-intelligence-based diagnosis methods have been proposed. However, because of the nature of data-driven methods, conventional artificial intelligence requires large amount of measurement values to train and achieve enough diagnosis resolution. We propose a graph neural network (GNN) based accident diagnosis algorithm to achieve high diagnosis resolution with limited measurements. The proposed algorithm is trained with both the knowledge about physical correlation between components and measurement values. To validate the proposed methodology has a sufficiently high diagnostic resolution with limited measurement values, the diagnosis of multiple accidents was performed with limited measurement values and also, the performance was compared with convolution neural network (CNN). In case of the experiment that requires low diagnostic resolution, both CNN and GNN showed good results. However, for the tests that requires high diagnostic resolution, GNN greatly outperformed the CNN.

Development of a flexible composite based on vulcanized silicon casting with bismuth oxide and characterization of its radiation shielding effectiveness in diagnostic X-ray energy range and medium gamma-ray energies

  • Ibrahim Demirel;Haluk Yucel
    • Nuclear Engineering and Technology
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    • 제56권7호
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    • pp.2570-2575
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    • 2024
  • The study aims to develop a novel, lead-free, flexible and lightweight composite shielding material against ionizing radiation. For this, it was used bismuth oxide (Bi2O3) in RTV-2 silicon matrix. The shielding tests were carried out in both diagnostic X-ray energies and intermediate gamma-ray energy range of up to 662 keV to determine the radiation attenuation properties of this material in terms of attenuation ratio, half value layer, tenth value layer, mean free path and lead equivalency of samples in weight of 30%, 40%, 50% in Bi2O3. In the diagnostic X-ray energy range, half value layer, tenth value layer and lead equivalency (in mm Pb) of the produced samples were measured at 80 and 100 kVp narrow beam conditions according to the requirements of EN IEC 61331-1 standard. The results show that lead equivalent values of the produced novel sheets was measured to be 0.16 mm Pb, corresponding to a 6 mm thickness of the flexible sample when it contains 30% wt. Bi2O3 in RTV matrix. The experimental findings for durability and flexibility also indicated that this new RTV-based flexible, lead -free shielding composite can be used safely for especially for manufacturing aprons, garments and thyroid guards used in mammography, radiology, nuclear medicine and dental applications in practice.

A comparison of tests for homoscedasticity using simulation and empirical data

  • Anastasios Katsileros;Nikolaos Antonetsis;Paschalis Mouzaidis;Eleni Tani;Penelope J. Bebeli;Alex Karagrigoriou
    • Communications for Statistical Applications and Methods
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    • 제31권1호
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    • pp.1-35
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    • 2024
  • The assumption of homoscedasticity is one of the most crucial assumptions for many parametric tests used in the biological sciences. The aim of this paper is to compare the empirical probability of type I error and the power of ten parametric and two non-parametric tests for homoscedasticity with simulations under different types of distributions, number of groups, number of samples per group, variance ratio and significance levels, as well as through empirical data from an agricultural experiment. According to the findings of the simulation study, when there is no violation of the assumption of normality and the groups have equal variances and equal number of samples, the Bhandary-Dai, Cochran's C, Hartley's Fmax, Levene (trimmed mean) and Bartlett tests are considered robust. The Levene (absolute and square deviations) tests show a high probability of type I error in a small number of samples, which increases as the number of groups rises. When data groups display a nonnormal distribution, researchers should utilize the Levene (trimmed mean), O'Brien and Brown-Forsythe tests. On the other hand, if the assumption of normality is not violated but diagnostic plots indicate unequal variances between groups, researchers are advised to use the Bartlett, Z-variance, Bhandary-Dai and Levene (trimmed mean) tests. Assessing the tests being considered, the test that stands out as the most well-rounded choice is the Levene's test (trimmed mean), which provides satisfactory type I error control and relatively high power. According to the findings of the study and for the scenarios considered, the two non-parametric tests are not recommended. In conclusion, it is suggested to initially check for normality and consider the number of samples per group before choosing the most appropriate test for homoscedasticity.

Exploration and Development of SERVQUAL

  • Kim, Yong-Pil;Kim, Kye-Wan;Yun, Deok-Gyun
    • International Journal of Quality Innovation
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    • 제4권1호
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    • pp.116-130
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    • 2003
  • The gap-based SERVQUAL model is a popular service quality determinant due to its superior diagnostic capacity over alternative explanatory frameworks. However, some researchers criticize the performance of the SERVQUAL model and propose alternative service Quality measurement constructs. Nevertheless, it is argued that the superior diagnostic capacity of SERVQUAL is its key strength; and that any criticism made of it when making comparison with alternative models does not reflect the differing nature of scales of statistical analysis. Arguably, the only limitation of a gap-based model is misinterpretation of customers' evaluation and perception of a service. In this research, the gap score is transformed into a ratio score. Also, empirical tests and implications are presented to support this alternative contribution to the body of knowledge.

Application of Joint Electro-Chemical Detection for Gas Insulated Switchgear Fault Diagnosis

  • Li, Liping;Tang, Ju;Liu, Yilu
    • Journal of Electrical Engineering and Technology
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    • 제10권4호
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    • pp.1765-1772
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    • 2015
  • The integrity of the gas insulated switchgear (GIS) is vital to the safety of an entire power grid. However, there are some limitations on the techniques of detecting and diagnosing partial discharge (PD) induced by insulation defects in GIS. This paper proposes a joint electro-chemical detection method to resolve the problems of incomplete PD data source and also investigates a new unique fault diagnosis method to enhance the reliability of data processing. By employing ultra-high frequency method for online monitoring and the chemical method for detecting SF6 decomposition offline, the acquired data can form a more complete interpretation of PD signals. By utilizing DS evidence theory, the diagnostic results with tests on the four typical defects show the validity of the new fault diagnosis system. With higher accuracy and lower computation cost, the present research provides a promising way to make a more accurate decision in practical application.

양수발전소 발전-전동기 운전중 감시 시스템의 개발 (Development of On-Line Monitoring System for Pumped Storage Generator/Motor)

  • 김희동;주영호
    • 대한전기학회논문지:전기물성ㆍ응용부문C
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    • 제53권3호
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    • pp.168-174
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    • 2004
  • On-line monitoring system(OMS) has been developed for the pumped storage generator/motor The OMS is applied to diagnosis of the PD(partial discharge) activity of stator insulation, the shorted-turn of rotor winding and the variation of the air-gap between stator and rotor. The OMS consists of DAS(data acquisition system), main server system, gateway and display PC. The DAS measures the PD, the shorted-turn and air-gap from three sensors installed on the generator/motor. The gateway controls the data which sent by DAS. The main server system saves the data, analyzes the data and conducts the diagnostic algorithm. The display PC shows the diagnostic results of partial discharge, shorted-turn and air-gap. Field tests were conducted using PDA(partial discharge analyzer). The results of the OMS and PDA measurements can be directly correlated with normalized quantity number(NQN), PD magnitude(Qm) and PD pattern.

변전소 예방진단시스템 모니터링 프로그램 개발 (Development of a Monitoring Program for the Substation Preventive Diagnostic System)

  • 권동진;최인혁;신한철;이호진;정용준
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2001년도 하계학술대회 논문집 C
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    • pp.1623-1625
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    • 2001
  • This paper describes a monitoring program for a substation preventive diagnostic system. The monitoring program announces the condition of the transformer and GIS like normal, warning, abnormal and danger from the absolute value of data or change trend to user. The developed system is operating in 345kV U-Ryung substation for performance and environment tests.

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Obligatory Control and Coordinated Deletion as Korean Subject Diagnostics: An Experimental Approach

  • Kim, Ji-Hye;Lee, Yong-hun;Kim, Eunah
    • 한국언어정보학회지:언어와정보
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    • 제19권1호
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    • pp.75-101
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    • 2015
  • This study investigated the distribution of subject properties in Korean. Based on the previous studies on so-called 'subjecthood diagnostics' in Korean Multiple Subject Constructions (MSCs), the current study investigates how different subject properties are distributed in single subject constructions (Non-MSCs) and MSCs. Focusing on two distinct subject properties - obligatory control (OC) of PRO and coordinated deletion (CD) - an empirical syntactic experiment was designed to test how these two subjecthood diagnostics behave in the Non-MSC and MSC environments. Seventy Korean native speakers were tested over magnitude estimation task, composed of 80 Korean sentences representing different subject properties in single or multiple subject constructions. Overall results showed (i) both OC and CD can be used as subjecthood diagnostic tests in the Non-MSC environments, but (ii) that only OC can be used as a subjecthood diagnostic test in the MSC environments.

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