• Title/Summary/Keyword: diagnostic indicator

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New Diagnostic Technique and Device for Lightning Arresters by Analyzing the Wave Height Distribution of Leakage Currents (누설전류의 파고분포 분석에 의한 새로운 피뢰기 진단기술 및 장치)

  • 길경석;한주섭;송재영;조한구;한문섭
    • The Transactions of the Korean Institute of Electrical Engineers C
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    • v.52 no.12
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    • pp.562-567
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    • 2003
  • Lightning arresters are deteriorated by repetition of protective operation against overvoltages or impulse currents in environments of its use. If a deteriorated arrester is left in power lines, it can lead to an accident such as a line to ground fault even in a normal system. Therefore, it is necessary to eliminate the deteriorated arrester in advance by checking the soundness of arresters on a regular basis, and to ensure the reliability of power systems by preventing accidents. Various deterioration diagnostic techniques and devices are suggested, and most of which measure leakage current components as an indicator of arrester ageing. However, the techniques based on the magnitude of leakage current measure simply RMS or peak value of leakage current components and do not provide detailed information needed in the diagnosis. In this study, we found that the wave height distributions of the total leakage currents are remarkably changed or a new wave height are produced with the progress of arrester deterioration. To propose a new technique for the diagnosis, we designed a leakage current detection unit and an analysis program which can measure leakage current magnitudes and analyze wave height distributions. From the experimental results, we confirmed that the proposed technique by analyzing the wave height distribution can simply diagnose the mode of defects such as a partial damage and an existence of punctures in arresters as well as deterioration of arresters.

Importance of Relative Comparison of Capsular Widths on the Affected and Non-Affected Sides of Temporomandibular Joint Arthralgia Patients: An Ultrasonography Study

  • Hee-Won Kim;Yong-Woo Ahn;Sung-Hee Jeong;Soo-Min Ok;Hye-Mi Jeon;Hye-Min Ju
    • Journal of Oral Medicine and Pain
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    • v.48 no.3
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    • pp.106-111
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    • 2023
  • Purpose: In this study, we evaluate the potential of the relative ratio of capsular width (RCW) between the affected side (Aff) and non-affected side (Non-aff) in patients with temporomandibular joint (TMJ) arthralgia. We assessed whether RCW may hold greater diagnostic significance than the objective capsular width (CW) reported in previous studies when diagnosing arthralgia using ultrasonography (US). Methods: Forty-nine patients were assessed using US, excluding four patients with bilateral arthralgia. The patients were divided into two groups: 40 with unilateral arthralgia (UA), and nine without arthralgia (NA). We measured CW and masseter muscle thickness using US. Moreover, we employed RCW to analyze the variances between the groups. The numerical rating scale (NRS) and RCW were compared before and after dexamethasone injection in 10 patients who underwent follow-up evaluations. Results: Within the UA group, CW on the Aff was found to be significantly larger compared to the Non-aff (p<0.001). Additionally, RCW in the UA group was greater than that in the NA group (p<0.01). Furthermore, after dexamethasone injection, a reduction in the NRS and RCW values was observed in the 10 patients who were followed up. Conclusions: While previous studies have suggested a link between arthralgia and TMJ effusion, making CW a possible indirect diagnostic indicator for arthralgia, our findings propose that RCW could hold more diagnostic value than objective CW. However, additional studies are required to standardize the protocols for interpreting US results and determining the cutoff value of RCW in diagnosing TMJ arthralgia.

Recovery Voltage Measurements of Oil-immersed Transformer

  • Li, Ming-Hua;Dong, Ming;Qu, Yan-Ming;Yan, Zhang
    • Transactions on Electrical and Electronic Materials
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    • v.7 no.5
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    • pp.230-234
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    • 2006
  • One of the methods currently being investigated as a possible non-intrusive diagnostic tool for condition monitoring of power transformer and cable is the recovery voltage measurement, which will be improving the ability to detect the content of water concentration and the ageing process in the insulation system and may thus be an indicator of insulation quality and its ageing status. The polarization phenomenon was studied using RVM with oil-paper samples. In order to interpret its mechanism, the Extended Debye model was introduced. With different circuit parameters, various simulation results were gotten. Furthermore, with the test samples of different ageing condition, measurements are accomplished in the lab. On the basis of this experiment as well as theoretical analysis, correlations between polarizations and ageing were analyzed.

Influence of Steel Bar on Ultrasonic Velocity in Concrete (콘크리트 속의 철근이 초음파 속도에 미치는 영향)

  • Kim, Do-Hyun;Rhim, Hong-Chul
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2014.05a
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    • pp.122-123
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    • 2014
  • Measurement of the strength of concrete is an important indicator of the safety of the fresh as well as old concrete structures. It is possible to evaluate the strength of the concrete by means of an ultrasonic velocity method which is a kind of non-destructive inspection method for safety diagnostic evaluation of the building structures with aging. Steel embedded in the concrete and age of the concrete may affect ultrasonic pulse velocity. In order to accurately assess the strength of the concrete, it is necessary to understand rebar embedded in the concrete, steel shapes in various forms which effect ultrasonic pulse velocity. In this study, by measuring the velocity of ultrasonic waves generated when the waves pass through the ultrasonic pulse in a direction perpendicular to the reinforcing bars embedded in concrete, the effect of reinforcing bars on ultrasonic velocity accurately was verified and used to estimate the strength of the concrete.

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Characteristics of RFCT for Partial Discharge Measurement in the Stator Winding of Rotating Machines (회전기 고정자 권선의 부분방전 측정용 RFCT 특성)

  • Kang, Dong-Sik;Yoon, Dae-Hee;Hwang, Don-Ha;Kim, Yong-Joo;Chang, Ki-Chan;Song, Sang-Ock
    • Proceedings of the KIEE Conference
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    • 2001.07c
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    • pp.1616-1618
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    • 2001
  • In recent the on-line partial discharge (PD) measurement using sensors, such as EMC, SSC, RTD and RFCT, as an indicator of stator winding insulation condition has been developed. RFCT sensor was placed arounding a grounding lead of surge capacitor to detecting PD. Trend of PD magnitude/phase angle/pulse number over time are useful parameter to diagnosis aging state. We have developed Radio Frequency Current Transformer(RFCT) sensor which is suitable for PD diagnostic measurement in 6.6kV rotating machines. In this paper, we describe the characteristics of RFCT sensor, such as frequency and PD magnitude using 6.6 kV model stator winding in Lab.

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$^{18}F-FDG-PET/CT$ in Prostate Cancer (전립선암에서 $^{18}F-FDG-PET/CT$)

  • Jeon, Tae-Joo
    • Nuclear Medicine and Molecular Imaging
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    • v.42 no.sup1
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    • pp.116-120
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    • 2008
  • Prostate cancer is the second leading cause of cancer death of men in western countries and the death related to this disease in Korea is also getting increased. Although anatomic imaging tools such as transrectal US or MRI have been playing a great role in detection of primary prostate lesion, the evaluation of regional lymph node or distant organ metastasis using these modalities is not successful. $^{18}F-FDG-PET$ scan is emerging diagnostic tool for various malignancies. Considering the usual characteristics of prostate cancer such as slow growing and osteoblastic metastasis, the application of FDG PET scan to this disease might be limited. However, in advanced prostate cancer refractory to chemotherapy, FDG PET scan show strong FDG uptake and SUV changes in serial PET scan can be a good indicator of treatment response. Although FDG PET can be useful only in limited cases of prostate cancer, its indication can be widened in future owing to rapid technical improvement and accumulated experiences in this field.

A Specific Biomarker for The Diagnosis of Equine Laminitis (말의 제엽염 진단을 위한 특이적 생물지표)

  • Lee, Seungwoo;Lee, Seung Heon;Kim, Myung-Chul;Kim, Yong-Baek;Ryu, Doug-Young
    • Journal of Veterinary Clinics
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    • v.32 no.1
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    • pp.62-68
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    • 2015
  • There is no reliable indicator available for the diagnosis of horse laminitis, although the disease is common and costly. This study was performed to develop a specific diagnostic biomarker for laminitis. We have identified 33 differentially expressed proteins in plasma of a horse suffering laminitis that is experimentally induced by an overdose of oligofructose, in comparison with normal horse plasma. Among the proteins, myosin-9 mRNA was found in RNA sequencing analysis to be expressed specifically in laminitis tissues compared to other horse tissues. It is thus suggested that expression of plasma myosin-9 may be used for the diagnosis of equine laminitis.

An Exploratory Study for Development of Self Diagnose Scale on the Healthy Family - Uses the GAMMA Model - (건강한 가정만들기를 위한 자가진단 척도 개발의 기초연구 - 감마모델을 중심으로 -)

  • Kim, Sung-Hee
    • Journal of Family Resource Management and Policy Review
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    • v.11 no.4
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    • pp.55-71
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    • 2007
  • The purpose of this study was to explore a self-diagnostic indicator for measuring a healthy family by adopting the theme of "happiness", which has surfaced as the most interesting in many academic fields recently. Though the basic concept of a healthy family may be shared by everyone, the criterion of happiness varies from one family to another. Therefore, it is desirable that the tool be made in such a way that every member of the family can check their health from a holistic perspective, rather than diagnosing health and happiness from the perspective of professionals. So, this study was aimed at diagnosing a family by using a tool named GAMMA model, so each family member can recognize problems and find the best options to solve it. This study. has a significant meaning in that it has tried to diagnose families by introducing the GAMMA model into domestic science for the first time.

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Haptoglobin as an early indicator of infection in horses (말에서 감염의 조기진단을 위한 haptoglobin 지표 연구)

  • 조길재;조광현
    • Korean Journal of Veterinary Service
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    • v.27 no.2
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    • pp.147-151
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    • 2004
  • The objective of present study was to assess the diagnostic value of the concentration of haptoglobin, one of a series of acute phase proteins that is found in the blood of both humans and animals. A total of 79 random horse sera(10 dam and 69 foals) with clinically normal were analyzed by ELISA. The mean serum concentrations of haptoglobin of dam and foals were 1.67${\pm}$0.52mg/ml(range 1.08∼2.12 mg/ml), 1.65${\pm}$0.50 mg/ml(range 0.50∼2.66 mg/ml), respectively. These results may provide basic information for developing a useful marker system to monitor infections early in horses.

Prenatal chromosomal microarray analysis of fetus with increased nuchal translucency

  • Shim, So Hyun;Cha, Dong Hyun
    • Journal of Genetic Medicine
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    • v.15 no.2
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    • pp.49-54
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    • 2018
  • Nuchal translucency is an important indicator of an aneuploid fetus in prenatal diagnostics. Previously, only the presence of aneuploid could be confirmed by conventional karyotyping of fetuses with thick nuchal translucency. With the development of genetic diagnostic techniques, however, it has been reported that subtle variations not detectable by conventional karyo-typing might occur in cases of pathologic clinical syndrome in euploid fetuses. One of the newer, high-resolution genetic methods in the prenatal setting is chromosomal microarray. The possible association between nuchal translucency thickness with normal karyotype and submicroscopic chromosomal abnormalities detectable by microarray has been studied. How and when to apply microarray in clinical practice, however, is still debated. This article reviews the current studies on the clinical application of microarray in cases of increased nuchal translucency with normal karyotype for prenatal diagnosis.