• Journal of Korean Neurosurgical Society
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• v.41 no.2
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• pp.120-122
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• 2007

Meningiomas arise from meningothelial cells that line the arachnoid membrane. So most meningiomas are dural-based lesion. But meningiomas without dural-attachment do occur and are less common. We report our experience of intraparenchymal sylvian fissure menigioma. A 21-year-old female presented with a one-month history of headache that was associated with long-term intermittent partial seizure. CT revealed about $4.5{\times}4.3{\times}5.5cm$ sized calcified mass with enhancement in right temporal lobe. On MR imaging, the lesion was observed in the right temporal lobe that was low-signal intensity on T2WI and iso-signal intensity on T1WI with well enhancement. Operation was performed via right orbitocranial approach. The internal surface of dura was intact. Tumor was totally removed except the capsule of tumor adhered to main trunk of middle cerebral artery. The histopathology showed meningioma, psammomatous type. Intraparenchymal meningioma should be considered in the differential diagnosis of intraaxial lesions in patients of any age group.

• Journal of the Korean Society for Precision Engineering
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• v.23 no.4 s.181
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• pp.124-131
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• 2006

A gerotor pump is suitable for oil hydraulics of machine tools, automotive engines, compressors, constructions and other various applications. Especially the pump is an essential machine element of an automotive engine to feed lubricant oil. The subject of this paper is the theoretical analysis of internal lobe pump whose the main components are the rotors: usually the outer one is characterized by lobes with circular shape, while the inner rotor profile is determined as conjugate to the other. For this reason the first topic presented here is the definition of the geometry of the rotors starting from the design parameters. The choice of these parameters is subject to some limitations in odor to limit the pressure angle between the rotors. Now we will consider the design optimization. The first step is the determination of the instantaneous flow rate as a function of the design parameter. This allows us to calculate three performance indexes commonly used far the study of positive displacement pumps: the flow rate irregularity, the specific flow rate, and the specific slipping. These indexes are used to optimize the design of the pump and to obtain the sets of optimum design parameter. Results obtained from the analysis enable the designer and manufacturer of oil pump to be more efficient in this field, and the system could serve as a valuable one for experts and as a dependable training aid for beginners.

• Journal of Chest Surgery
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• v.34 no.8
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• pp.640-643
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• 2001

A case of endobronchial tuberculosis with left main bronchial stenosis and atelectasis of left lower lobe in a 26-year-old female is reported. She had taken antituberclous agents for 9 months, but she complained of chest pain and coughing. Bronchoscopy revealed patency of left upper bronchus and bronchiectasis of left lower lobe. She underwent left lower lobectomy with bronchoplasty. After the operation she had significant improvement of pulmonary function. Although surgical treatment of endobronchial tuberculosis is controversial, bronchoplastic surgery can be an effective treatment of tuberculous bronchial stenosis because it relieves patients from symptoms by preserving lung functions.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.44 no.3
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• pp.39-44
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• 2007

In this paper, satellite searching and tracking method for the satellite antenna in naval vessels system are proposed. For fast searching satellite, Wide Range Search(WRS) algorithm is proposed where the signal strength of side-lobe is utilized as well as that of main-lobe. Satellite tracking algorithm to stabilize satellite antenna is based on conical-scanning which is accomplished by the use of the sub-reflector located in front of the focus of the reflector. The sub-reflector rotates about a slightly tilted axis by means of a motor and shapes the antenna beam to utilize stabilization. To show the validity of the proposed method, an experimental example is represented.

• Journal of the Korea Institute of Military Science and Technology
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• v.16 no.6
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• pp.811-818
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• 2013

In this paper, we have designed the elliptical dual offset gregorian antenna which can use Ka band earth station antennas in the fixed-satellite service. The structure of antenna is increasing the antenna gain by decreasing blockage areas and decreasing wind effects by shortening height of the antenna. The corrugate horn antenna for this antenna has symmetric radiation patterns and low side lobe levels that can meet ITU-R envelope. The distribution of electric field on a aperture of main reflector is calculated by an ray-tracing method that use the radiation pattern of the feed horn. The final geometric of antena is decided by choosing the distribution that comply with antenna requirement. The FEKO analysed electrical performance of this antenna. The fabricated antenna has 45.0dBi(@30.0GHz)/41.7dBi(@20.2GHz), high efficiency and low side lobe level that meet ITU-R S. 580-6 envelope.

• Journal of Korean Neurosurgical Society
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• v.45 no.5
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• pp.289-292
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• 2009

Objective : Although there are several descriptions of this vessel, there is no detailed angiographic study of the accessory middle cerebral artery (AMCA) in Korea. We describe the angiographic characteristics of the cortical territory and origin of AMCA and discuss the clinical significance of this anomaly. Methods : We searched for patients with AMCAs from a retrospective review of 1,250 conventional cerebral angiograms. We determined the origins, diameters and cortical territories of these AMCAs. Results : Fifteen patients (15 of 1250 = 1.2%) had 16 AMCAs (one patient had bilateral AMCAs). AMCAs originated from the distal A1 in eleven cases, middle A1 in two, proximal A1 in two, and proximal A2 in one case. All AMCAs followed a course parallel to the main middle cerebral artery (MCA). All but three of these arteries were smaller than the main MCA. Thirteen of the smaller diameter AMCAs had cortical distribution to the orbito-frontal and prefrontal, and precentral areas. Three AMCAs had diameter as large as the main MCA. These three supplied the orbito-frontal, prefrontal, precentral, central and anterior-parietal arteries. Conclusion : The AMCAs originated from A1 or A2. Most had smaller diameter than the main MCA. The AMCAs coursed along the horizontal portion of the MCA, but supplied the orbital surface, the anterior frontal lobe and sometimes wider cortical territory, including the precentral, central, anterior-parietal areas.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.20 no.1
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• pp.91-102
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• 1990

The aim of this study was to establish the diagnostic criteria of normal parotid glands in adults revealing the anatomical shape, its variations and the postitional relationships of the gland. Materials included 96 lateral and anterior-posterior sialograms of selected person from 23 to 28 years of age. Results were as follows: 1. The average length and lateral displacement of main duct was 48.43㎜ and l6.88㎜. The mean lumen diameter of that was 0.91㎜ in distal end and 1.40㎜ in hilar end in parotid glands. 2. The average angle of main duct to the inferior border of mandib was 34.32 degree. In configurations of main duct, modified curvilinear type was. most prevalent and followed by curvilinear, reverse sigmoid, sigmoid type. 3. The mean caliber of parotid gland was the longest in superior-inferior. 4. The interlobar ducts showed relatively well defined in all cases, its average number was 5.72. Arrangement of these ducts showed at random. Accessory lobe showed 87.5% in the all cases, its average number was 1.7. 5. There were no difference between the well and poorly defined acinar fillings in the glandular parenchyme. 6. There were no differences between right and left parotid glands in size and shape of main duct and parenchymal portion, but there were great variations in each individuals.

• Proceedings of the KOR-BRONCHOESO Conference
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• 1978.06a
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• pp.5.1-5
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• 1978

Since Ikeda in traduced flexible fiberoptic bronchoscope in 1968, use of bronchoscopy was expanded rapidly. Wide use of flexible bronchoscopy enabled us to get tissue diagnosis with more ease and safety. Authors analyzed 71 cases of tissue biopsy of 233 bronchoscopies from June '76 to. Jan. '78 and concluded as following : 1. 233 bronchoscopies af 20 Month duration, cases which needed tissue biopsy were 71 cases (30.5%). 2. Chief complaints af above cases are coughing, dyspnea, sputum, chest pain, hemoptysis in frequency. 3. Biopsy sites were as following in frequency: Rt.upper lobe, Lt. main bronchus, Lt. upper lobe, Rt. main bronchus, Lt. lower lobe. 4. The final diagnosis of biopsied cases were cancer 80%, tuberculosis 15%, and malignant mesothelioma, anthracosis, aspergillosis, were one case each. 5. Among 57 case of lung cancer, biopsy confirmed cases were 36 cases (63%). 6. Pathologic finding of 36 case of Biopsy confirmed lung cancer was as following: Squamous cell ca : 64% Anaplastic ca : 25% Adeno ca : 2.8% Unclassified: 2.8% 7. Bronchographies were done in 36cases (51%), one quarter of cases before biopsy, and three quarters of cases after biopsy. 8. Cytology was requested in 76% of cases with following results; PAP class V 15%, class IV 7.5%, class III 1.8%.

• Korean Journal of Cognitive Science
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• v.21 no.3
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• pp.409-427
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• 2010

Psychological research on the relationships between creativity and knowledge can be divided into two main streams, called tension view and foundation view. However most of the studies in this area have been too much focused on creative products which had a limit in investigating creative processes. In this study, to identify the relationships, we employed neuro-scientific approaches to investigating EEG (electroencephalogram) activity from professional computer programmers(n=10). Also the EEG alpha TRP (task related power) was compared with each other. The procedures including resting conditions with eye closed were followed by ordinary thinking process, creative thinking processes in a professional domain and a nonprofessional domain. As a result of EEG activity analysis, alpha deactivation was observed mainly in temporal lobe, especially in left-temporal lobe during creative thinking process of professional domain. The findings suggest that neuro-scientific approach supports the tension view, suggesting that the knowledge could hinder creativity.

• Journal of the Korean Geotechnical Society
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• v.33 no.11
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• pp.21-34
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• 2017

The ground penetrating radar (GPR) signal can be measured with different amplitudes according to the directivity, so the directivity of the antenna should be considered. The objective of this study is to investigate the directivity of antenna by analyzing the reflection characteristics of electromagnetic waves radiated from the antenna, and to evaluate effective range of angle that can inspect an abnormal area according to the directivity of antenna. For the measurement of the directivity, a circular metal bar is used as reflector and the signals are measured by changing the angle and the distance between reflector and antenna in the E- and H-plane. The boundary distance between the near field and the far field is determined by analyzing the amplitudes of reflected signals, and two points with different distances from each of near and far fields are designated to analyze radiation patterns in near and far fields. As a result of radiation pattern measurement, in the near field, minor lobes are observed at angle section at more than $50^{\circ}$ in both E- and H-plane. Therefore, antenna has the directivity for the direction of main lobe and minor lobes in near field. In the far field, antenna has the directivity for a single direction of main lobe because minor lobes are not observed. The amplitude of the signal reflected from the near field is unstable, but it can be distinguished from noise. Therefore, in the near field, the ground anomaly can be detected with high reliability. On the other hand, the amplitude of the signal reflected from the far field is stable, but it is hard to distinguish between reflected signal and noise because of the excessive loss of electromagnetic wave. The analyses of directivity in the near and the far fields performed in this study may be effectively used to improve the reliability of the analyses of abnormal area.