• Nuclear Engineering and Technology
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• v.45 no.5
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• pp.581-588
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• 2013

This paper deals with the Safety Analysis for $CANDU^{(R)}$ 6 nuclear reactors as affected by main Heat Transport System (HTS) aging. Operational and aging related changes of the HTS throughout its lifetime may lead to restrictions in certain safety system settings and hence some restriction in performance under certain conditions. A step in confirming safe reactor operation is the tracking of relevant data and their corresponding interpretation by the use of appropriate thermal-hydraulic analytic models. Safety analyses ranging from the assessment of safety limits associated with the prevention of intermittent fuel sheath dryout for a slow Loss of Regulation (LOR) analysis and fission gas release after a fuel failure are summarized. Specifically for fission gas release, the thermal-hydraulic analysis for a fresh core and an 11 Effective Full Power Years (EFPY) aged core was summarized, leading to the most severe stagnation break sizes for the inlet feeder break and the channel failure time. Associated coolant conditions provide the input data for fuel analyses. Based on the thermal-hydraulic data, the fission product inventory under normal operating conditions may be calculated for both fresh and aged cores, and the fission gas release may be evaluated during the transient. This analysis plays a major role in determining possible radiation doses to the public after postulated accidents have occurred.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.26 no.4
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• pp.116-121
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• 2018

According to the incresement of aging aircraft, Republic of Korea Air Force (RoKAF) conducted a teardown inspection of aircraft's EWIS (electrical wiring interconnection system) to determine the status of deterioration and the influence of failure occurrences due to it. The inspected aircraft were the retired fighter jets that had been used for more than 40 years. By analyzing defect type and the defect tendency, RoKAF can establish the necessary measures for the usage extension of their fleet and furthermore, the analysis results can be used as a basic data for the preparation of it's aircraft aging. EWIS inspection was done throughout careful visual inspection technique by removing all the ducts and pipes located in the fuselage and wings. For the aircraft wiring where no damage was found, the elongation tests were performed to determine the deterioration of wiring according to the location of the aircraft. The connectors, which is the main cause of intermittent failure, were completely disassembled and inspected for internal damage such as corrosion, abrasion, and traces of foreign objects. The detected defects were classified into 4 severity levels based on the type of damage, and the classified defects were weighted according to the criticality which may affects to it's system to establish the action plan.

• Journal of the Korean Academy of Esthetic Dentistry
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• v.13 no.2
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• pp.7-11
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• 2004

The Schwachman-Diamond syndrome is an autosomal recessive syndrome(1/20,000 births), consisting of pancreatic insufficiency, neutopenia, which may be intermittent, neutrophil chemotaxis defects, metaphyseal dysostosis, failure to thrive and short stature. Patients present in infancy with poor growth and grease, foul-smelling stools that are characteristic of malabsorption. These children can be readily differentiated from those with cystic fibrosis by their normal sweat chloride levels, lack of the cystic fibrosis gene, and characteristic metaphyseal lesions. Pathologically, the pancreatic acini are replaced by fat with little fibrosis. The neutropenia may be cyclic. Recurrent pyogenic infections otitis media, pneumonia, dermatitis(fig 1), sepsis are common and a frequent cause of death. In dental examination, these patients had a poor oral hygine and moderate generalized marginal gingivitis, also show delayed primary tooth exfoliation and oral development. This report illustrates a case that pancreatic agenesis 6 yeas-old boy with various esthetic dental problems has been served the esthetic dental restoration of 6 years.

• Proceedings of the KSR Conference
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• 2000.05a
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• pp.336-343
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• 2000

This paper proposes the failsafe control logic. which has applied to the voting on the TMR system by using FPGA The self-detection circuit is also designed for detecting a characteristic of fault at TMR system. The fault producing in the self-detection system is largely classified among an intermittent fault, a transient fault and a permanent fault. If it is happened to the permanent fault, the system can be failed. Therefore, it is designed the logic circuit which is not transferred the permanent fault to the system after shut off output. The control logic of the Fail Safe proposed in the paper is required for a circuit integrate of device to minimize the failure happened. Therefore, it makes to design FPGA with modeling of VHDL. The circuit of the Fail Safe of TMR system is able to apply to nuclear system, rail-way system, aerospace and aircraft system which is required for high reliability.

• Journal of Veterinary Clinics
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• v.38 no.6
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• pp.295-298
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• 2021

A 1-year-old spayed female Scottish Fold cat presented with a 1.5-month history of vomiting, intermittent dyspnea, and abdominal distention. Radiographic, ultrasonographic, and computed tomographic examinations suggested a tentative diagnosis of a fluid-containing cystic mass with an internal septum. The mass was surgically removed. Histological examinations revealed that the mass was a non-neoplastic hepatic cyst. The patient had no recurrence of the cystic structure but died of acute renal failure 5 years after the surgery. This report describes the unusual case of a giant hepatic cyst with clinical signs that resolved after mass removal.

• Journal of Drive and Control
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• v.20 no.4
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• pp.54-63
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• 2023

High and intermittent loading cycles induce fatigue damage to transmission components, resulting in premature gearbox failure. To identify gearbox defects, numerous vibration-based diagnostics techniques, using several artificial intelligence (AI) algorithms, have recently been presented. In this paper, an optimized deep belief network (DBN) model for gearbox problem diagnosis was designed based on time-frequency visual pattern identification. To optimize the hyperparameters of the model, a particle swarm optimization (PSO) approach was integrated into the DBN. The proposed model was tested on two gearbox datasets: a wind turbine gearbox and an experimental gearbox. The optimized DBN model demonstrated strong and robust performance in classification accuracy. In addition, the accuracy of the generated datasets was compared using traditional ML and DL algorithms. Furthermore, the proposed model was evaluated on different partitions of the dataset. The results showed that, even with a small amount of sample data, the optimized DBN model achieved high accuracy in diagnosis.

• Journal of Veterinary Clinics
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• v.33 no.1
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• pp.34-38
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• 2016

A 13-year-old castrated male mixed breed dog and a 12-year-old castrated male mixed breed cat were referred to the hospital for the treatment of pulmonary edema and azotemia at the same time. To resolve the pulmonary edema and azotemia, intermittent hemodialysis (HD) was performed using ultrafiltration (UF), and the pulmonary edema, azotemia, other electrolyte and acid-base imbalances were improved. This case study demonstrated that when we encountered pulmonary edema patients with diuretic resistance, severe electrolyte imbalance, and impaired renal function complicated by decongestive therapy using diuretics, UF therapy can be considered a life-saving intervention.

• Journal of Energy Engineering
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• v.25 no.4
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• pp.13-29
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• 2016

In this study, we analyzed the causes of major faults in the biogas plant through the case of gas engine failure when cogenerating electricity and heat using biogas as a fuel in the actual sewage treatment plant and suggested countermeasures. Hydrogen sulfide in the biogas entering the biogas engine and water caused by intermittent malfunction of the water removal system caused intercooler corrosion in the biogas engine. In addition, the siloxane in the biogas forms a silicate compound with silicon dioxide, which causes scratches and wear of the piston surface and the inner wall of the cylinder liner. The substances attached to the combustion chamber and the exhaust system were analyzed to be combined with hydrogen sulfide and other impurities. It is believed that hydrogen sulfide was supplied to the desulfurization plant for a long period of time because of the high content of hydrogen sulfide (more than 50ppm) in the biogas and the hydrogen sulfide was introduced into the engine due to the decrease of the removal efficiency due to the breakthrough point of the activated carbon in the desulfurization plant. In addition, the hydrogen sulfide degrades the function of the activated carbon for siloxane removal of the adsorption column, which is considered to be caused by the introduction of unremoved siloxane waste into the engine, resulting in various types of engine failure. Therefore, hydrogen sulfide, siloxane, and water can be regarded as the main causes of the failure of the biogas engine. Among them, hydrogen sulfide reacts with other materials causing failure and can be regarded as a substance having a great influence on the pretreatment process. As a result, optimization of $H_2S$ removal method seems to be an essential measure for stable operation of the biogas engine.

• Journal of Veterinary Clinics
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• v.24 no.1
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• pp.68-72
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• 2007

An 8-year-old, male Shih-tzu dog with clinical signs of hemorrhage from penile orifice and pain on lifting hindlimb was brought to the Veterinary Medicine Teaching Hospital, Chungnam National University. The patient was shown polyuria/polydipsia (PU/PD), more than 10 times per day, and gasterointestinal signs such as intermittent vomiting and melena. On laboratory examination, BUN, creatinine and amylase level were all highly increased. Radiographic and ultrasonographic findings included that both kidneys were abnormal, and both prostates were hyperplastic bilaterally and cysts were presented in parenchyma. Additionally, hyperechoic pancreas and intact urinary bladder were observed from ultrasonographic examination. The dog was diagnosed as pancreatitis, acute renal failure and benign prostatic hyperplasia (BPH). After the appropriate treatment for pancreatitis and acute renal failure, He dog was treated with administration of azasteroid for BPH. On day 71 after azasteroid treatment, good response to the treatment was defined by ultrasonography and clinical signs cured completely.

• Journal of Chest Surgery
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• v.34 no.10
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• pp.792-796
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• 2001

Chronic pulmonary artery thromboembolism is a relatively rare phenomenon causing hypoxia and pulmonary hypertension that eventually leads to respiratory failure and right heart failure. Patients with acute pulmonary artery thromboembolism are generally treated with antithrombotics and thrombolytics. However, in cases with chronic pulmonary artery thromboembolism the fibrinized thrombus is so strongly adhered to the pulmonary artery wall that medical treatment becomes ineffective and surgical treatment must then be considered. We report a 47year old patient, with a history of repeated admission due to unresolved chronic obstructive pulmonary disease and chronic pulmonary artery thromboembolism at a local hospital, who underwent a successful endarterectomy of pulmonary artery thromboemboli using intermittent total circulatory arrest.