• The Journal of the Korea institute of electronic communication sciences
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• v.11 no.1
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• pp.59-64
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• 2016

This paper aims at the prototype-making of the intelligent switchgear with arc fault diagnosis function required to prevent the electrical fire. The main control unit of the intelligent switchgear consists of a single-phase power management device and a arc fault diagnosis device. The prototype of the single-phase power management device and the prototype of the arc fault diagnosis device in this paper. In the device, the cooperation function with the arc fault diagnosis device is developed to transmit the cause of the electrical fire to the remote server system.

• International Journal of Naval Architecture and Ocean Engineering
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• v.8 no.3
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• pp.243-251
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• 2016

Autonomous Underwater Vehicles (AUVs) generally work in complex marine environments. Any fault in AUVs may cause significant losses. Thus, system reliability and automatic fault diagnosis are important. To address the actuator failure of AUVs, a fault diagnosis method based on the Gaussian particle filter is proposed in this study. Six free-space motion equation mathematical models are established in accordance with the actuator configuration of AUVs. The value of the control (moment) loss parameter is adopted on the basis of these models to represent underwater vehicle malfunction, and an actuator failure model is established. An improved Gaussian particle filtering algorithm is proposed and is used to estimate the AUV failure model and motion state. Bayes algorithm is employed to perform robot fault detection. The sliding window method is adopted for fault magnitude estimation. The feasibility and validity of the proposed method are verified through simulation experiments and experimental data.

• Journal of Sensor Science and Technology
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• v.23 no.1
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• pp.58-65
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• 2014

We developed a low-cost automatic diagnosis system for water quality in cooling towers to measure the concentrations of key ingredients such as $Ca^{2+}$, $Cl^-$, $PO{_4}^{3-}$, and $Fe^{2+}$. $Ca^{2+}$, and $Cl^-$ are the main factors that cause the generation of scale, corrosion, and sludge in water pipes. $PO{_4}^{3-}$ prevents corrosion, sludge and scale by inhibiting the ions (i.e., $Ca^{2+}$, $Cl^-$) from sticking to the pipes. $Fe^{2+}$ is an indicator of pipe corrosion. The proposed system consists of a microprocessor, a specimen container and heater, a precision pump, relays and valves, LED optical sources, and photo detectors. It automatically collects water samples and carries out pretreatment for determining the concentration of each chemical, and then estimates the concentration of each ion using low-cost LED optical sources and detectors. Experimental results showed that the accuracy of the proposed system is sufficiently high for water quality diagnosis and management of cooling towers, demonstrating the possibility of the proposed system's wide usage in real environments.

• Advances in pediatric surgery
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• v.8 no.1
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• pp.54-61
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• 2002

Hirschsprung's disease (HD) is usually diagnosed in the newborn period and early infancy. The common presentation of HD in newborns consists of a history of delayed passage of meconium within the first 48 hours of life. The differential diagnosis in newborns is one of the clinical challenges of this disorder. A number of medical conditions which cause functional obstruction of the intestines are easily excluded. Neonates with meconium ileus, meconium plug syndrome, distal ileal atresia and low imperforate anus often present in a manner similar to those with HD in the first few days of life. Abdominal radiographs may help to diagnose complete obstruction such as intestinal atresia. Microcolon on contrast enema can be shown in cases with total colonic aganglionosis, ileal atresia or meconium ileus. Suction rectal biopsy or frozen section biopsy at operation is essential for differential diagnosis in such cases. HD is also considered in any child who has a history of constipation regardless of age. Older children with functional constipation may have symptoms that resemble those of HD and contrast enema is usually diagnostic. However, children with other motility disorders generally referred to as chronic idiopathic intestinal pseudoobstruction present with very similar symptoms and radiographic findings. These disorders are classified according to their histologic characteristics.; visceral myopathy, visceral neuropathy, intestinal neuronal dysplasia (IND), hypoganglionosis, immature ganglia, internal sphincter achalasia. Therefore, the workup for motility disorders should include rectal biopsy not only to confirm the presence of ganglion cells but also evaluate the other pathologic conditions.

• Korean Journal of Cleft Lip And Palate
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• v.15 no.2
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• pp.83-88
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• 2012

Macroglossia is a relatively uncommon condition that occurs in pediatric patients for several reasons and contributes to variety of functional problems. Most of macroglossia arises from tissue overgrowth and tongue muscle hypertrophy. There are no definite guideline in prenatal management or diagnosis in this conditions. However, macroglossia is often associated with syndrome or congenital disease, prenatal diagnosis is important in early detection. There are difficulty in measurement of tongue size, and standardization. Macroglossia can be risky in some aspects, such as airway obstruction. In this review, the author suggest prenatal ultrasonographic findings of macroglossia, investigate differential diagnosis of conditions associated with macroglossia, and management in clinical situation. Macroglossia, when present, can cause a number of functional and aesthetic problems for individuals. Treatment of this problem is challenging and controversial.

• The Journal of the Korea Contents Association
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• v.7 no.3
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• pp.25-33
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• 2007

The unexpected failure may cause a break in power system and loss of profits. Therefore it Is important to prevent abrupt faults by monitoring the condition of power systems. In this paper, we develop intelligent diagnosis technique for predicting faults of power transformer which plays an important role in the transmission and distribution systems among the various power facilities by using FCM and SOM. More specifically, FCM is used to select the efficient training data and reducing learning process time and SOM is used to diagnosis the power transformer. The proposed technique makes it possible to measures the possibility of aging as well as the faults occurred in transformer To demonstrate the validity of proposed method, various experiments are performed and their results are presented.

• The Journal of the Acoustical Society of Korea
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• v.38 no.3
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• pp.363-369
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• 2019

Various studies have been conducted for the diagnosis of noise condition of complex rotary machines. In this study, diagnosis index using vibration signal is developed for the efficient and objective assessment of noise condition of a blower motor. The noise most commonly caused by the abnormal blower motor are Tick/Click noise and Tone noise. According to cause and noise characteristics, time-frequency analysis is used to diagnose Tick/Click noise, and smoothing in frequency domain is used to diagnose tone noise condition. The noise condition of the blower motors were diagnosed using the developed index and these results are compared with the diagnostic results by the experts. As a result, the agreement rate was about 95 %.

• International Journal of Internet, Broadcasting and Communication
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• v.13 no.2
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• pp.136-144
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• 2021

Railroad Systems, which are national infrastructure industries, cause unexpected property and human damage if they fail to function while operating. Accordingly, railroad facilities supporting the railroad system are areas where high reliability and safety are required. However, it is time for systematic and scientific maintenance to be taken away from the traditional maintenance methods, as the nation's railroad facilities are now aging seriously. The purpose of this study was to secure the safety and reliability of the aging railroad communication facilities and to improve their performance. The research subjects were selected as a precision diagnosis process for railroad communication facilities, and improvement points were derived through detailed precision diagnosis process analysis. It is deemed that this study can contribute based on securing stability, improving reliability, and continuous improvement of railroad communication facilities should be conducted in the operation of the entire railroad system.

• Archives of Plastic Surgery
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• v.50 no.1
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• pp.101-105
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• 2023

Benign cartilaginous tumors, known as chondrogenic tumors, show cartilage components in the microscopic diagnosis. We present two clinical cases with cartilaginous tumors of the toes showing distinctive clinical manifestations. Two juvenile patients visited our outpatient clinic due to tumors with toenail deformities. A 10-year-old girl presented with a palpable mass with a nail deformity on the left third toe. The initial pathology report was soft tissue chondroma until complete resection. Another 15-year-old male patient visited the dermatology department with a toenail deformity and underwent a punch biopsy. The pathology report was fibrosis with myxoid degeneration. Excisional biopsies were performed for both patients. In the operative field, we observed exophytic tumors connected to the distal phalangeal bones. The final pathology reports were subungual osteochondroma on both patients. The specimen exhibited mature bone trabeculae with a focal cartilaginous cap. Benign cartilaginous tumors have a slow, progressive course and do not show significant symptoms. However, tumors in subungual areas are accompanied by toenail deformities and they can cause pain. Their clinical characteristics lead to a delayed diagnosis. Surgeons can be confused between soft tissue and chondrogenic tumors. When they conduct physical examinations, these categories should be considered in the differential diagnosis.

• Journal of Oral Medicine and Pain
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• v.47 no.4
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• pp.217-221
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• 2022

Neurogenic muscular atrophy is muscle wasting and weakness caused by trauma or disease of the nerve that innervates the muscle. We describe a case of unilateral trigeminal neuropathy and neurogenic muscular atrophy of the masticatory muscle caused by a tumor in the foramen ovale. A 59-year-old man visited our clinic complaining of difficulty in right-sided mastication. There were no evident clinical signs and symptoms of temporomandibular disorder. However, severe atrophy of the right masseter and temporalis muscles and hypesthesia of the right side mandibular nerve area were confirmed. Through T1 and T2 signals on magnetic resonance imaging (MRI), a mass suspected of a neurogenic tumor was observed in the foramen ovale and cavernous sinus. Severe atrophy of all masticatory muscles on the right side was observed. This rare case shows trigeminal neuropathy caused by a tumor around the foramen ovale and atrophy of the ipsilateral masticatory muscles. For an accurate diagnosis, it is essential to identify the underlying cause of muscle atrophy with neurologic symptoms present. This can be done through a more detailed clinical examination, including sensory testing and brain MRI, and consider a referral to neurology or neurosurgery for the differential diagnosis of the intracranial disorder.