• Title/Summary/Keyword: diagnostic approach

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Early-onset epileptic encephalopathies and the diagnostic approach to underlying causes

  • Hwang, Su-Kyeong;Kwon, Soonhak
    • Clinical and Experimental Pediatrics
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    • v.58 no.11
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    • pp.407-414
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    • 2015
  • Early-onset epileptic encephalopathies are one of the most severe early onset epilepsies that can lead to progressive psychomotor impairment. These syndromes result from identifiable primary causes, such as structural, neurodegenerative, metabolic, or genetic defects, and an increasing number of novel genetic causes continue to be uncovered. A typical diagnostic approach includes documentation of anamnesis, determination of seizure semiology, electroencephalography, and neuroimaging. If primary biochemical investigations exclude precipitating conditions, a trial with the administration of a vitaminic compound (pyridoxine, pyridoxal-5-phosphate, or folinic acid) can then be initiated regardless of presumptive seizure causes. Patients with unclear etiologies should be considered for a further workup, which should include an evaluation for inherited metabolic defects and genetic analyses. Targeted next-generation sequencing panels showed a high diagnostic yield in patients with epileptic encephalopathy. Mutations associated with the emergence of epileptic encephalopathies can be identified in a targeted fashion by sequencing the most likely candidate genes. Next-generation sequencing technologies offer hope to a large number of patients with cryptogenic encephalopathies and will eventually lead to new therapeutic strategies and more favorable long-term outcomes.

On the Logistic Regression Diagnostics

  • Kim, Choong-Rak;Jeong, Kwang-Mo
    • Journal of the Korean Statistical Society
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    • v.22 no.1
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    • pp.27-37
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    • 1993
  • Since the analytic expression for a diagnostic in the logistic regression model is not available, one-step estimation is often used by a case-deletion point of view. In this paper, infinitesimal perturbation approach is used, and it is shown that the scale transformation of infinitesimal perturbation approach is eventually equal to the weighted perturbation of local influence approach and the replacement measure. Also, multiple cases deletion for the masking effect is considered.

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Local Influence of the Quasi-likelihood Estimators in Generalized Linear Models

  • Jung, Kang-Mo
    • Communications for Statistical Applications and Methods
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    • v.14 no.1
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    • pp.229-239
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    • 2007
  • We present a diagnostic method for the quasi-likelihood estimators in generalized linear models. Since these estimators can be usually obtained by iteratively reweighted least squares which are well known to be very sensitive to unusual data, a diagnostic step is indispensable to analysis of data. We extend the local influence approach based on the maximum likelihood function to that on the quasi-likelihood function. Under several perturbation schemes local influence diagnostics are derived. An illustrative example is given and we compare the results provided by local influence and deletion.

Diagnostic Approach of Hepatic Mass using Ultrasound Guided Fine Needle Aspiration in a Dog (개에서 초음파를 이용한 간 종괴의 세침흡인술 증례)

  • 최호정;이기창;최민철;윤정희
    • Journal of Veterinary Clinics
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    • v.21 no.2
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    • pp.181-183
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    • 2004
  • Hepatic mass was aspirated under the guidance with ultrasound in 9-year old female maltese with signs of anorexia, hematochezia, vomiting, depression, and abdominal distension. Radiographic and abdominal ultrasonographic examinations were performed, which revealed enlarged tubular shaped uterine mass and solitary, small round hyperechoic hepatic mass dorsal to gall bladder as an incidental finding. Ultrasound-guided fine needle aspiration was completed, but histologic confirmation should be made for definitive diagnosis by tissue core or wedge biopsy.

Review of expert system applications to chemical process fault diagnosis (화학공정 결함진단을 위한 전문가 시스템 적용에 관한 고찰)

  • 오전근;윤인섭
    • 제어로봇시스템학회:학술대회논문집
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    • 1987.10b
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    • pp.674-679
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    • 1987
  • Process failures can occur at any time during operation, so a continuous effort of fault detection, diagsis, and correction is required. Expert system paridigm has been regarded as a promising approach to real time process supervisory control especially to fault diagnosis. The most important aspects of fault diagnostic expert systems(FDES) are the problem-solving inference strategy and knowledge organizations. The necessity of FDES, the nature of diagnostic knowledge, the representation of knowledge, and the inference mechanism of FDES, et al. are described, which are announced by previous researchers. And the existing FDES are categorized and critically reviewed in this work.

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A Real-Time Method for the Diagnosis of Multiple Switch Faults in NPC Inverters Based on Output Currents Analysis

  • Abadi, Mohsen Bandar;Mendes, Andre M.S.;Cruz, Sergio M.A.
    • Journal of Power Electronics
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    • v.16 no.4
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    • pp.1415-1425
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    • 2016
  • This paper presents a new approach for fault diagnosis in three-level neutral point clamped inverters. The proposed method is based on the average values of the positive and negative parts of normalized output currents. This method is capable of detecting and locating multiple open-circuit faults in the controlled power switches of converters in half of a fundamental period of those currents. The implementation of this diagnostic approach only requires two output currents of the inverter. Therefore, no additional sensors are needed other than the ones already used by the control system of a drive based on this type of converter. Moreover, through the normalization of currents, the diagnosis is independent of the load level of the converter. The performance and effectiveness of the proposed diagnostic technique are validated by experimental results obtained under steady-state and transient conditions.

Malformations of cortical development: genetic mechanisms and diagnostic approach

  • Lee, Jeehun
    • Clinical and Experimental Pediatrics
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    • v.60 no.1
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    • pp.1-9
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    • 2017
  • Malformations of cortical development are rare congenital anomalies of the cerebral cortex, wherein patients present with intractable epilepsy and various degrees of developmental delay. Cases show a spectrum of anomalous cortical formations with diverse anatomic and morphological abnormalities, a variety of genetic causes, and different clinical presentations. Brain magnetic resonance imaging has been of great help in determining the exact morphologies of cortical malformations. The hypothetical mechanisms of malformation include interruptions during the formation of cerebral cortex in the form of viral infection, genetic causes, and vascular events. Recent remarkable developments in genetic analysis methods have improved our understanding of these pathological mechanisms. The present review will discuss normal cortical development, the current proposed malformation classifications, and the diagnostic approach for malformations of cortical development.

A real-time operation aiding expert system using the symptom tree and the fault-consequence digraph

  • Oh, Jeon-Keun;Yoon, En-Sup;Choi, Byung-Nam
    • 제어로봇시스템학회:학술대회논문집
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    • 1989.10a
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    • pp.805-812
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    • 1989
  • An efficient diagnostic approach for real-time operation aiding expert system in chemical process plants is discussed. The approach is based on the hybrid of the simplified symptom tree(SST) and the fault consequence digraph(FCD), representation of propagation patterns of fault states. The SST generates fault hypothesis efficiently and the FCD resolve the real fault accurately. Frame based knowledge representation and object-oriented programming make diagnostic system general and efficient. Truth maintenance system enables robust pattern matching and provides enhanced explain facilities. A prototype expert system for supports operation of naphtha furnaces process, called OASYS, has been built and tested to demonstrate this methodology. Utilization of diversified process symbolic data, produced using dynamic normal standards, overcomes the problem of qualitative Boolean reasoning and enhance the applicability.

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A Model-Based Fault Detection and Diagnosis Methodology for Cooling Tower

  • Ahn, Byung-Cheon
    • International Journal of Air-Conditioning and Refrigeration
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    • v.9 no.3
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    • pp.63-71
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    • 2001
  • This paper presents a model-based method for detecting and diagnosing some faults in the cooling tower of healing, ventilating, and air-conditioning systems. A simple model for the cooling tower is employed. Faults in cooling tower operation are detected through the deviations in the values of system characteristic parameters such as the heat transfer coefficient-area product, the tower approach, the tower effectiveness, and fan power. Three distinct faults are considered: cooling tower inlet water temperature sensor fault, cooling tower pump fault, and cooling tower fan fault. As a result, most values of the system characteristics parameter variations due to a fault are much higher or lower than the values without faults. This allows the faults in a cooling tower to be detected easily using above methods. The diagnostic rules for the faults were also developed through investigating the changes in the different parameter due to each faults.

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Dermoid Cyst of Nasal Tip with a Sinus Tract Extending to the Intracranium: A Case Report

  • Lee, Seungjun;Kim, Seong-Ik;Kim, Min-Seo;Kim, Jong-Ho
    • Archives of Plastic Surgery
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    • v.49 no.5
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    • pp.648-651
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    • 2022
  • Nasal dermoid cysts are rare congenital anomalies that affect one in 20,000 to one in 40,000 individuals. Herein, we report a case of an initially misdiagnosed nasal dermoid cyst with intracranial extension. Among nasal dermoids, the lesion of the nasal tip is considered uncommon. Therefore, this should always be considered as a differential diagnosis of midline nasal masses, and a proper diagnostic approach should be taken.