• The Journal of Korea Robotics Society
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• v.6 no.2
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• pp.173-181
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• 2011

Recognition of traffic signs helps an unmanned ground vehicle to decide its behavior correctly, and it can reduce traffic accidents. However, low cost traffic sign recognition using a vision sensor is very difficult because the signs are exposed to various illumination conditions. This paper proposes a new approach to solve this problem using an illuminometer which detects the intensity of illumination. Using the intensity of illumination, the recognizer adjusts the parameters for image processing. Therefore, we can reduce the loss of information such as the shape and color of traffic signs. Experimental results show that the proposed method is able to improve the performance of traffic sign recognition in various weather and lighting conditions.

• Journal of Korean Neurosurgical Society
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• v.39 no.5
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• pp.347-354
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• 2006

Objective : We evaluate the role of multislice computerized tomographic angiography[MCTA] in the diagnosis of intracranial vasospasm following subarachnoid hemorrhage[SAH] in patients suspected of having vasospasm on clinical ground. Methods : Between October 2003 and June 2005, patients with ruptured cerebral aneurysms of the anterior circulation clipped within 3 days of the onset were included. We performed follow-up MCTAs in patients who were suspected to have vasospasm on transcranial doppler sonography[TCD] findings and clinical grounds. Based on the clinical presentation of symptomatic vasospasm, we investigated the correlation between clinical, TCD, and MCTA signs of vasospasm and evaluated the role of MCTA in vasospasm. Results : One hundred one patients met the inclusion criteria and symptomatic vasospasm developed in 25 patients [24.8%]. We performed follow-up MCTAs in 28 patients. MCTA revealed spasm in the vessels of 26 patients. The sensitivity of MCTA was 100%. Among the 26 patients with MCTA evidence of vasospasm, 3 patients had TCD signs of vasospasm after symptomatic vasospasm presentation. Another 3 patients with symptomatic vasospasm had no TCD signs of vasospasm in daily serial recordings. Six other patients without symptomatic vasospasm showed MCTA evidence of vasospasm [false positive result] but these patients had also positive TCD signs of vasospasm. Volume rendering[VR] images tended to show significantly more exaggerated vasospasm than maximum intensity projection[MIP] images. The mean cerebral blood flow velocity of both proximal segment of the middle cerebral artery [M1] was significantly correlated with each reduced M1 diameter on MCTA [P<005]. Conclusion : MCTA could be a useful tool for evaluation and planning management of critically ill patients suspected of having vasospasm; however, more randomized controlled trials are necessary to assess these points definitively.

• Journal of Educational Research in Mathematics
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• v.13 no.1
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• pp.25-55
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• 2003

In the school mathematics, the negative numbers have been instructed by means of intuitive models(concrete situation models, number line model, colour counter model), inductive-extrapolation approach, and the formal approach using the inverse operation relations. These instructions on the negative numbers have caused students to have the difficulty in understanding especially why the rules of signs hold. It is due to the fact that those models are complicated, inconsistent, and incomplete. So, students usually should memorize the sign rules. In this study we studied on the didactical phenomenology of the negative numbers as a foundational study for the improvement of teaching negative numbers. First, we analysed the formal nature of the negative numbers and the cognitive obstructions which have showed up in the historic-genetic process of them. Second, we investigated what the middle school students know about the negative numbers and their operations, which they have learned according to the current national curriculum. The results showed that the degree they understand the reasons why the sign rules hold was low Third, we instructed the middle school students about the negative number and its operations using the formal approach as Freudenthal suggest ed. And we investigated whether students understand the formal approach or not. And we analysed the validity of the new teaching method of the negative numbers. The results showed that students didn't understand the formal approach well. And finally we discussed the directions for improving the instruction of the negative numbers on the ground of these didactical phenomenological analysis.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.5
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• pp.86-92
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• 2017

As the elderly population increases, real-time personal health monitoring is gaining new ground with advances in wireless communications. Such an approach is particularly beneficial to elderly and physically challenged people, as well as those who live alone and are not be able to seek help in case of medical emergencies. The aim of this study is to implement a wearable band which monitors personal vital signs, such as the body temperature and heart rate, and assists with healthcare decisions using a fuzzy logic based decision support system. Since the vital sign data measured from sensors are imprecise and their normal variation with age is nonlinear and not crisp, a fuzzy system is employed to deal with this imprecise or uncertain information. The proposed wearable band is designed to continuously capture and transmit vital signs and healthcare decisions to suitable apps developed for smartphones. In this way, health alerts can be sent to the guardian or caregiver who is registered in the apps.

• Tuberculosis and Respiratory Diseases
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• v.64 no.1
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• pp.52-56
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• 2008

A pheochromocytoma is a neuroectodermal tumor that originates from the chromaffin cells of the sympathetic system. Typical symptoms or signs are periodic attacks of paroxysmal hypertension, spell, palpitation, headache and sweating. However, the clinical presentation is quite variable. Therefore, an atypical clinical presentation sometimes makes a diagnosis difficult. Hemoptysis as a presenting symptom is very rare in pheochromocytoma. We recently experienced a patient with diffuse alveolar hemorrhage due to pheochromocytoma. A chest PA showed diffuse consolidation and ground glass opacities in both lungs. A chest CT showed diffuse consolidation and ground glass opacities in the central, middle and lower portion predominance of the lungs, sparing the costophrenic angles and apices of the lungs. In Korea, a case of pheochromocytoma that presented initially as massive hemoptysis due to diffuse alveolar hemorrhage has not been previously reported. We report the case with a review of the literature.

• Journal of Yeungnam Medical Science
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• v.37 no.1
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• pp.59-62
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• 2020

Hemoptysis is a major reason for emergency department (ED) visits. Catamenial hemoptysis (CH), a rare condition of thoracic endometriosis, can cause recurrent hemoptysis but is difficult to diagnose in the ED due to the scarcity of cases and nonspecific clinical findings. We report a case of a 26-year-old woman who presented to the ED with recurrent hemoptysis since 2 years without a definite cause. Her vital signs and blood test findings were unremarkable. Chest computed tomography (CT) did not show any specific lesions other than a non-specific ground-glass opacity pattern in her right lung. She was on day 4 of her menstrual cycle and her hemoptysis frequently occurred during menstruation. Although there was no histological confirmation, based on her history of hemoptysis during menstruation and no other cause of the hemoptysis, the patient was tentatively diagnosed with CH and was administered gonadotropin-releasing hormone. She had no recurrence of hemoptysis for 3 months. While CH is difficult to diagnose in the ED, the patient's recurrent hemoptysis related to menstruation was a clue to the presence of CH. Therefore, physicians should determine the relationship between hemoptysis and menstruation for women of childbearing age presenting with repeated hemoptysis without a definite cause.

• Nuclear Engineering and Technology
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• v.53 no.5
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• pp.1612-1618
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• 2021

The fusion-barrier distribution is very sensitive to the structure of the colliding nuclei such as nuclear quadrupole and hexadecapole deformation parameters and their signs. If the nuclei that enter the fusion reaction are deformed, the barrier problem becomes complicated. Therefore the deformation parameters are taken into account in the calculations. In this study, Neuro-Fuzzy approach, ANFIS, method has been used for the estimation of ground-state quadrupole (𝜀₂) and hexadecapole (𝜀₄) deformation parameters for the nuclei. According to the results, the method is suitable for this task and one can confidently use it to obtain the data that is not available in the literature.

• Structural Monitoring and Maintenance
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• v.2 no.1
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• pp.35-48
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• 2015

The main objective of this study is to evaluate the long-term performance of various concrete composites in natural marine environment prevailing in the Gulf region. Durability assessment studies of such nature are usually carried out under aggressive environments that constitute seawater, chloride and sulfate laden soils and wind, and groundwater conditions. These studies are very vital for sustainable development of marine and off shore reinforced concrete structures of industrial design such as petroleum installations. First round of testing and evaluation, which is presented in this paper, were performed by standard tests under laboratory conditions. Laboratory results presented in this paper will be corroborated with test outcome of ongoing three years field exposure conditions. The field study will include different parameters of investigation for high performance concrete including corrosion inhibitors, type of reinforcement, natural and industrial pozzolanic additives, water to cement ratio, water type, cover thickness, curing conditions, and concrete coatings. Like the laboratory specimens, samples in the field will be monitored for corrosion induced deterioration signs and for any signs of failureover initial period ofthree years. In this paper, laboratory results pertaining to microsilica (SF), ground granulated blast furnace slag (GGBS), epoxy coated rebars and calcium nitrite corrosion inhibitor are very conclusive. Results affirmed that the supplementary cementing materials such as GGBS and SF significantly impacted and enhanced concrete resistivity to chloride ions penetration and hence decrease the corrosion activities on steel bars protected by such concretes. As for epoxy coated rebars applications under high chloride laden conditions, results showed great concern to integrity of the epoxy coating layer on the bar and its stability. On the other hand corrosion inhibiting admixtures such as calcium nitrite proved to be more effective when used in combination with the pozzolanic additives such as GGBS and microsilica.

• Transactions of the Korean Society of Automotive Engineers
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• v.3 no.1
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• pp.54-64
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• 1995

The effects of swirl on early flame development and late combustion characteristic were investigated using a high speed single-shot visualized 51 engine. LDV measurements were performed to get better understanding of the flow field in this combustion chamber. Spark plugs were located at half radius (R/2) and central location of bore. High speed schlieren photographs at 20,000 frames/sec were taken to visualize the detailed formation and development of the flame kernel with cylinder pressure measurements. This study showed that high swirl gave favorable effects on combustion-related performances in terms of the maximum cylinder pressure and flame growth rate regardless of spark position. However, at R/2 ignition the low swirl shown desirable effects at low engine speed gave worse performances as engine speed increased than without swirl. There were distinct signs of slow-down in flame growth during the period when the flame front expanded from 2.5mm in radius until it reached 5.0mm apparently due to the presence of ground electrode. There seemed to be heat transfer effect on the flame expansion speed which was evidenced in high swirl case by the slowdown of the late flame front presumably caused by relatively large heat loss from burned gas to wall compared with low- or no-swirl cases.

• Korean Journal of Veterinary Research
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• v.24 no.1
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• pp.99-104
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• 1984

Authors observed an outbreak of porcine pleuropneumonia at a piggery in Gyeongbug, Korea, which were diagnosed on the ground of clinical and pathological findings with the following results. 1. One hundred and forty weanlings out of 200 ones died suddenly without noticiable signs during the period of 15 days. All of the dead pigs showed formy, blood-tinged discharge from the nose and mouth. 2. Main clinical findings observed from 60 alive pigs from group consisted of fever, cyanosis severe degree of dyspnea and pleuritic friction rub. 3. On hematological observation for typical 5 cases leukocytes showed marked degenerative left shift with leukopenia (10500-13070/cmm), neutropenia (7-13%) and increase in the number of band neutrophils (6-27%). 4. The most prominent and constant pathological changes observed at necropsy for dead or alive pigs consisted of fibrinous pleurisy with partial adhesion, overlying of the pulmonary surface with fibrinous menbrane and necrotic pneumonic lesions with marked edema and congestion of lung parenchyma. 5. From these results the outbreak was considered to be typical porcine pleuropneumonia, although no bacteriological isolation was attempted.