• The Transactions of the Korean Institute of Electrical Engineers P
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• v.65 no.3
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• pp.188-193
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• 2016

It has been proven that the dissolved gas analysis (DGA) is the most effective and convenient method to diagnose the transformers. The DGA is a simple, inexpensive, and non intrusive technique. Among the various diagnosis methods, IEC 60599 has been widely used in transformer in service. But this method cannot offer accurate diagnosis for all the faults. This paper proposes a fault diagnosis method of oil-filled power transformers using DGA and Intelligent Probability Model. To demonstrate the validity of the proposed method, experiment is performed and its results are illustrated.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.65 no.1
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• pp.41-46
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• 2016

It has been proven that the dissolved gas analysis (DGA) is the most effective and convenient method to diagnose the transformers. The DGA is a simple, inexpensive, and non intrusive technique. Among the various diagnosis methods, IEC 60599 has been widely used in transformer in service. But this method cannot offer accurate diagnosis for all the faults. This paper proposes a fault diagnosis method of oil-filled power transformers using IEC code based neuro-fuzzy model. The proposed method proceeds two steps. First, IEC 60599 method is applied to diagnosis. If IEC code can't determine the fault type, neuro-fuzzy model is applied to effectively classify the fault type. To demonstrate the validity of the proposed method, experiment is performed and its results are illustrated.

• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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• 2001.05a
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• pp.32-37
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• 2001

This paper describes a noble fault diagnosis method using inter node search technique in PN model. First, a complicated fault system is modeled as PN graphic expressions. Next, to find out sources for faults on which we focus, the PN model is analyzed using the backward chaining of T-invariance. In this step, the technique of inter node search is applied for reducing some range of sources in a fault. Also, colnposing method of incidence matrix in PN is proposed. Then, it makes the diagnosis system to very flelible system because new knowledges about the sources in a fault can be added easily to conventional systems. Finally, the proposed method is applied to the automobile trouble diagnosis system to confirm the validity of the method.

• Journal of Ocean Engineering and Technology
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• v.15 no.4
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• pp.101-107
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• 2001

This paper describes a fault diagnosis method by a T-invariance of Petri Net (PN). First, a complicated fault system with some failure is modeled into a PN graphic expressions. Next, the PN model is analyzed by using the backward chaining of T-invariance to find out causes of the faults. In this step, an inter-node search technique which is suggested in this paper is applied for reducing searching area in the fault system. Also, a novel idea to compose incidence matrices which have different dimension each other in PN model is proposed. As the new knowledges which is discovered newly about faults can be added easily to conventional systems, the diagnosis system will be very flexible. Finally, the proposed method is applied to the automobile fault diagnosis system to confirm the validity of the method.

• Journal of the Korean Society for Precision Engineering
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• v.15 no.1
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• pp.19-25
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• 1998

Remote fault diagnosis and maintenance system using general telecommunication network is necessary for an effective fault diagnosis and higher productivity of NC machine tools. In order to monitor machine tool condition and diagnose alarm states due to electrical and mechanical faults, a remote data communication system for monitoring of NC machine fault diagnosis and status is developed. The developed system consists of (1) remote communication module among NC's and host PC using PSTN. (2) 8 channels analog data sensing module, (3) digital I/O module for control or NC machine, (4) communication module between NC machine and remote data communication system via RS-232C, and (5) software man-machine interface. Diagnostic monitoring results generated through a successive type inference engine are displayed in user-friendly graphics. The validity and reliability of the developed system is verified to be a powerful commercial version on a vertical machining center through a series of experiments.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
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• v.22 no.2
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• pp.120-127
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• 2011

Objectives:The purpose of this study was to verify discriminant validity and the clinical cutoff score of Child Behavior Checklist 1.5-5 in the diagnosis of developmental delayed infants. Methods:The participants were screened by Denver II which includes 156 developmental delayed infants and 288 normal infants. Chi-squared test, t-test, ROC curve analysis, odds ratio analysis were performed on the data. Results:Only 47 items out of 99 items among the CBCL 1.5-5 of total groups, 36 items of boys and 48 items of girls, discriminated developmental delayed infants well. Discriminant validity was confirmed by mean differences on the subscales of Withdrawn, Sleep Problems, Attention Problems, Internalizing Problems, Externalizing Problems, Total Problems, DSM Pervasive Developmental Problems and DSM Attention Deficit/Hyperactivity Problems between the two groups. Additionally, ROC analyses demonstrated that Withdrawn, Attention Problems, Internalizing Problems, Total Behavior Problems and DSM Pervasive Developmental Problems significantly predicted developmental delayed infants compared to normal infants. Also, the clinical cutoff score criteria adopted in the Korean CBCL 1.5-5 for subscales of Withdrawn, Attention Problems, Internalizing Problems, Total Behavior Problems and DSM Pervasive Developmental Problems were shown to be valid. Conclusion:The subscales of Withdrawn, Attention Problems, Internalising Problems, Total Behavior Problems and DSM Pervasive Developmental Problems significantly discriminated in the diagnosis of developmental delayed infants well.

• The Korean Journal of Pain
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• v.22 no.2
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• pp.146-150
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• 2009

Background: A skin temperature difference is one of the variables used in the diagnosis of complex regional pain syndrome. However, there have been no reports as to whether the real (${\Delta}T$) or absolute value ($|{\Delta}T|$) of skin temperature differences should be used in the diagnosis of complex regional pain syndrome. This study was conducted to compare the diagnostic validity of ${\Delta}T$ with $|{\Delta}T|$ for complex regional pain syndrome using receiver operating characteristic curves (ROC). Methods: Infrared thermographic images were obtained from the 144 patients who were suspected to have CRPS in a unilateral limb. After ${\Delta}T$ and $|{\Delta}T|$ calculation from the thermographic image, ROCs of ${\Delta}T$ and $|{\Delta}T|$ were developed, and the areas under the curve (AUC) for the ROC curves were compared. Results: AUCs of ${\Delta}T$ and $|{\Delta}T|$ were 0.520 and 0.746 respectively, this difference was statistically significant (P < 0.001). Conclusions: Absolute skin temperature difference shows greater validity in the diagnosis of CRPS than ${\Delta}T$. Therefore, $|{\Delta}T|$ is more useful when comparing the skin temperature of CRPS patients.

• The Journal of Korean Medicine
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• v.35 no.3
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• pp.93-102
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• 2014

Objectives: This study aimed at revising the Korean Out-patient Groups for Korean Medicine (KOPG-OM, version 1.0) based on clinical similarity and resource use, by using the accumulated claims data, and evaluating the validity of the revised classification system. Methods: A clinical specialist panel involving 19 specialists from 8 Korean medicine (KM) specialty areas reviewed the classification tree, diagnosis groups and procedure groups in terms of clinical similarity. Several models of outpatient grouping were formulated, with the validity of each tested based on the $R^2$ coefficient of determination for the treatment costs of all visits. To add age splits, the variances of treatment costs by age groups were also analyzed. These statistical analyses were performed using KM claims data of National Health Insurance from 2010 to 2012. Results: The classification tree designed via panel discussions was used to allocate outpatient cases to 26 diagnosis groups, with cases involving procedures such as acupuncture, moxibustion and cupping, then allocated to 9 procedure groups in each diagnosis group. The cases without procedures were categorized into the visit index - medication group. This process resulted in 298 outpatient groups. The $R^2$ values for treatment costs of all visits ranged from 0.38 to 0.69 depending on the providers' types. Conclusions: The revised model of KOPG-KM has a higher validity for outpatient classification than the current system and can provide better management of the costs of outpatient care in KM.

• Journal of the Korean Society for information Management
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• v.41 no.1
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• pp.1-30
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• 2024

The purpose of this study is to develop a diagnostic tool to strengthen the reading competencies of children and adolescents with disabilities, analyze its validity and reliability, and present basic data for the development of a diagnostic program. For this study, it was conducted on literature and case studies, the Delphi Method, and a preliminary survey of actual disabled children/adolescents. As a result of the study, there were limitations in validity and reliability analysis due to the small number of samples, but basic data was secured along with the development of a prototype diagnostic tool for the reading ability of children and adolescents with disabilities. It was proposed to develop the future reading competency diagnostic program by expanding it to the web and mobile platforms, considering various variables such as the characteristics of each disability type, a plan for data collection and utilization through big data, diagnostic procedures, and precautions during the diagnosis.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
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• v.26 no.1
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• pp.30-37
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• 2015

Objectives: The purpose of this study was to verify the validity and clinical cutoff score of the Child Behavior Checklist for ages 1.5-5 (CBCL 1.5-5) for diagnosis of autism spectrum disorder (ASD). Methods: 44 ASD infants and 100 normal infants participated. T-test, discriminant analysis, receiver operating characteristic (ROC) curve analysis, and odds ratio analysis were performed on the data. Results: Discriminant validity was confirmed by mean differences and discriminant analysis on the subscales of Withdrawn, Attention problems, Internalizing problems, Externalizing problems, Total problems, and all Diagnostic and Statistical Manual of Mental Disorders (DSM)-oriented scales between the two groups. ROC curve analysis showed that Withdrawn, Attention problems, Internalizing problems, Externalizing problems, Total problems, DSM pervasive developmental problems, DSM attention deficit/hyperactivity problems, and DSM oppositional defiant problems significantly predicted ASD infants compared to normal infants. In addition, the clinical cutoff score criteria adopted in the Korean CBCL 1.5-5 for subscales of Withdrawn, Attention problems, Internalizing problems, Externalizing problems, Total problems, DSM pervasive developmental problems, DSM attention deficit/hyperactivity problems, and DSM oppositional defiant problems were shown to be valid. Conclusion: The subscales of Withdrawn, Attention problems, Internalizing problems, Externalizing problems, Total problems, DSM pervasive developmental problems, DSM attention deficit/hyperactivity problems, and DSM oppositional defiant problems significantly discriminated for the diagnosis of ASD.