• Title/Summary/Keyword: diagnostic error

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Development of Diagnostic Expert Systems for A Rotor System (로터시스템의 이상진단시스템에 대한 연구)

  • Kim, Sung-Chul;Kim, Sang-Pyo;Kim, Young-Jin
    • Journal of Korean Institute of Industrial Engineers
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    • v.27 no.1
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    • pp.61-68
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    • 2001
  • A rotor system is composed of a rotating shaft with supporting bearings. The rotor system is widely used in every rotating machinery such as the turbine generator and the high precision machine tools. A negligible error or malfunction in the rotor, however, can cause a catastrophic failure in the system then result in the environmental and economic disasters. A diagnosis of the rotor system is important in preventing these kinds of failures and disasters. Up to now, many researchers have devoted in the development of diagnosing tools for the system. The basic principles behind the tools are to retrieve the data through the sensors for a specific state of the system and then to identify the specific state through the heuristic methods such as neural network, fuzzy logic, and decision matrix. The proper usage of the heuristic methods will enhance the performance of the diagnostic procedure when together used with the statistical signal processing. In this paper, the methodologies in using the above 3 heuristic methods for the diagnostics of the rotor system are established and also tested and validated for the data retrieved from the rolling element bearing and journal bearing supported system.

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Quantitative Study on Tongue Images according to Exterior, Interior, Cold and Heat Patterns (표리한열의 설 특성에 관한 정량적 연구)

  • Eo Yun-Hye;Kim Je-Gyun;Yoo Hwa-Seung;Kim Jong-Yeol;Park Kyung-Mo
    • The Journal of Korean Medicine
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    • v.27 no.2 s.66
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    • pp.134-144
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    • 2006
  • Tongue diagnosis is an important diagnostic method in traditional Oriental medicine. It has been especially accepted that quantitative analysis of tongue images allows the accurate diagnosis of the exterior-interior and cold-heat patterns of a patient. However, to ensure stable and reliable results, the color reproduction of such images must first be error-tree. Moreover, tongue diagnosis is much influenced by the surrounding illumination and subjective color recognition, so it has to be performed objectively and quantitatively using a digital diagnostic machine. In this study, 457 tongue images of outpatients were collected using the Digital Tongue Inspection System. Through statistical analysis, the result shows that the heat and cold patterns can be distinguished clearly based on the hue value of the tongue images. The average hue value (1.00) of the tongue's image in the cold pattern is higher than that in the heat pattern (0.99).

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Diagnosis of inherited metabolic disorders based on their diverse clinical features and laboratory tests (유전성 대사질환의 임상증상과 진단)

  • Yoo, Han-Wook
    • Clinical and Experimental Pediatrics
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    • v.49 no.11
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    • pp.1140-1151
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    • 2006
  • Inherited metabolic disorders are individually rare but as a whole, they are nor rare. Since Archibald Garrod introduced a concept of "inborn error of metabolism" or "chemical individuality", more than 500 diseases are currently known, affecting approximately one in 500 newborns cumulatively. They frequently manifest with acute, life-threatening crisis that require immediate specific intervention or they present with insidious diverse symptoms and signs involving multiple visceral organs or tissues as well as central nervous system, hampering a correct diagnosis. In addition, many pediatricians are not familiar with all diagnostic and therapeutic strategies for diverse inherited metabolic disorders. However, the prognosis of affected children are heavily dependent on rapid and effective treatment. In this lecture, practical guidelines for the specific diagnosis based on diverse clinical features of inherited metabolic disorders will be described. Many sophisticated laboratory tests are available for confirmatory diagnosis of each disease, which challenge to general pediatricians with respect to knowledge about biochemical metabolite assay test, enzymatic test and DNA diagnostic tests. Sample collections, indications, methods and interpretation of results in varying laboratory tests will be listed as well.

A Study of the Validity of and Cut-Off Scores for the Korean Version of Asperger Syndrome Diagnostic Scale (한국판 아스퍼거 증후군 진단척도의 타당화 및 진단 분할점 산출)

  • Kim, Ha-Na;Shin, Min-Sup
    • Journal of the Korean Academy of Child and Adolescent Psychiatry
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    • v.22 no.2
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    • pp.81-88
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    • 2011
  • Objectives : This study examined the reliability and validity of the Korean version of Asperger Syndrome Diagnostic Scale (K-ASDS), to calculate the cut-off score in the diagnosis of Asperger syndrome. Further, we examined classification error rate when applying cut-off scores. Methods : One hundred sixty-seven children participated in this study, including 46 with Asperger syndrome, 26 with PDD or PDD NOS, 43 with ADHD, and 52 normal children. Results : An ANCOVA demonstrated no significant differences in the K-ASDS total score between the Asperger and the PDD & PDD NOS groups. However, these groups did show significantly higher scores than the ADHD and normal groups. Among the five subscales on the K-ASDS, the Asperger group obtained significantly higher scores on the language and cognition subscales than the PDD & PDD NOS groups. Two scales were found to be useful in distinguishing the Asperger group from the PDD & PDD NOS group through a discriminant analysis. According to an analysis of ROC curve, the cut-off score on the K-ASDS for the diagnosis of PDD including Asperger syndrome was 121. Conclusion : We discussed that K-ASDS has pretty limit.

Diagnosis of Inherited Metabolic Disorders Based on Their Diverse Clinical Features and laboratory Tests (유전성 대사질환의 임상증상과 진단)

  • Yoo, Han-Wook
    • Journal of The Korean Society of Inherited Metabolic disease
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    • v.13 no.1
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    • pp.1-19
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    • 2013
  • Inherited metabolic disorders are individually rare but as a whole, they are nor rare. Since Archibald Garrod introduced a concept of "inborn error of metabolism" or "chemical individuality", more than 600 diseases are currently known, affecting approximately one in 500 newborns cumulatively. They frequently manifest with acute, life-threatening crisis that requires immediate specific intervention or they present with insidious diverse symptoms and signs involving multiple visceral organs or tissues as well as central nervous system, hampering a correct diagnosis. In addition, many pediatricians are not familiar with all diagnostic and therapeutic strategies for diverse inherited metabolic disorders. However, the prognosis of affected children are heavily dependent on rapid and effective treatment. In this lecture, practical guidelines for the specific diagnosis based on diverse clinical features of inherited metabolic disorders will be described. Many sophisticated laboratory tests are available for the confirmatory diagnosis of each disease, which is challenging to general pediatricians with respect to knowledge about biochemical metabolite assay test, enzymatic test and DNA diagnostic tests. Sample collections, indications, methods and interpretation of results in varying laboratory tests will be listed as well.

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Influence of Harmonics in Power System Voltage on Arrester Deterioration Diagnostics by Leakage Current Measurement (누설전류측정에 의한 피뢰기 열화진단에 있어 전원고조파의 영향)

  • 길경석;한주섭;주문노
    • The Transactions of the Korean Institute of Electrical Engineers C
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    • v.52 no.1
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    • pp.42-46
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    • 2003
  • Arresters are deteriorated by overvoltages or impulse currents, and the resistive leakage current of arresters increases as the deterioration of the arrester progresses, showing an increase in the 3$^{rd}$ harmonic component of the leakage current. In this reason, arrester diagnostic techniques based on the 3$^{rd}$ harmonic leakage current as a reference parameter of deterioration are widely used. The technique, however, includes an error due to the harmonics of power system voltage. Therefore, the influence of the harmonics on arrester diagnostics should be considered. In this paper, we designed a PSpice ZnO arrester model to simulate the influence of the voltage harmonics described above. A pure sinusoidal voltage and its the 3r harmonic voltage were applied to the model, and the leakage current components were analyzed. From the simulation results, it is confirmed that the peak value of resistive leakage current depends not only on the phase of the 3$^{rd}$ harmonic voltage but also on the magnitude of it. Consequently, the errors caused 1)y the harmonic voltage could be minimized by correcting the magnitude of leakage current upon analyzing the harmonics.cs.

Method of In-Vehicle Gateway to Reduce the Reprogramming Time (리프로그래밍 시간 단축을 위한 차량 게이트웨이 개선 방안)

  • Kim, Jin-Ho;Ha, Kyung-Jae
    • Journal of Convergence for Information Technology
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    • v.9 no.7
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    • pp.25-32
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    • 2019
  • This paper proposes the method of an in-vehicle gateway to reduce the reprogramming time for the ECU (Electronic Control Unit). In order to reduce the reprogramming time, the gateway must prohibit transmitting messages, that are not related to reprogramming, to the destination CAN network, and no ECU should diagnose the DTC(Diagnostic Trouble Code) that indicates CAN communication error caused by prohibiting CAN messages by the gateway. Moreover, STmin, which are the minimum time between two consecutive CAN messages, should be minimized. In order to do this, this paper proposes the method that uses the link control command specified in UDS(Unified Diagnostic Services) and hardware based gateway functionality that are supported by the latest MCU(Micro Controller Unit). The proposed method is developed using TC275 based embedded system, and its results are presented.

Robust Influenza Analysis Algorithm Based on Image Processing under Varying Radiometric Conditions (광원 환경에 강인한 영상 기반 인플루엔자 판독 기법)

  • Lee, Ji Eun
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.20 no.7
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    • pp.127-132
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    • 2019
  • Influenza is an infectious disease caused by an influenza virus with symptoms of high fever and headache. Since influenza especially mutates into multiple subtypes in the carrier's body, it is a serious threat for mankind such as Spanish influenza. The treatment of influenza infection mandates the use of antiviral drugs through rapid diagnostic test. Generally, immunochromatography-based rapid influenza diagnostic tests are used for rapid diagnosis in an emergency. In this paper, we propose an influenza analysis algorithm based on image processing to examine a large number of patients suspected of being infected with influenza. Also, we propose a robust influenza analysis algorithm based on the joint cumulative mass function under varying radiometric conditions such as illuminant and exposure differences. Simulation results show that the proposed algorithm significantly reduces the error of influenza diagnosis under different radiometric conditions.

Probabilistic-based damage identification based on error functions with an autofocusing feature

  • Gorgin, Rahim;Ma, Yunlong;Wu, Zhanjun;Gao, Dongyue;Wang, Yishou
    • Smart Structures and Systems
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    • v.15 no.4
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    • pp.1121-1137
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    • 2015
  • This study presents probabilistic-based damage identification technique for highlighting damage in metallic structures. This technique utilizes distributed piezoelectric transducers to generate and monitor the ultrasonic Lamb wave with narrowband frequency. Diagnostic signals were used to define the scatter signals of different paths. The energy of scatter signals till different times were calculated by taking root mean square of the scatter signals. For each pair of parallel paths an error function based on the energy of scatter signals is introduced. The resultant error function then is used to estimate the probability of the presence of damage in the monitoring area. The presented method with an autofocusing feature is applied to aluminum plates for method verification. The results identified using both simulation and experimental Lamb wave signals at different central frequencies agreed well with the actual situations, demonstrating the potential of the presented algorithm for identification of damage in metallic structures. An obvious merit of the presented technique is that in addition to damages located inside the region between transducers; those who are outside this region can also be monitored without any interpretation of signals. This novelty qualifies this method for online structural health monitoring.

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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    • v.31 no.1
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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.