• Solar Energy
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• v.19 no.1
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• pp.77-86
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• 1999

The optimal thermal design of a single heat source on one wall of a vertical open top cavity was studied experimentally. The temperature and flow fields in the cavity were visualized. The objectives of this study is to obtain the best location of the single heat source and to examine the effects of heat source protrusion, substrate thermal conductivity and cavity aspect ratio on the natural convection cooling due to a single heat source. As the results, the cooling effect for the copper substrate is superior to that of the epoxy-resin substrate and is improved with increasing cavity width. For the epoxy-resin substrate of lower conductivity, the protrusion of the heaters plays a role in decreasing the cooling effect. The best location was the mid-height of the substrate.

• Proceedings of the KIEE Conference
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• 1994.11a
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• pp.284-286
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• 1994

This paper describes the dielectric characteristics of $SF_6$ gas in non-uniform electric filed under lightning under lightning impulse and oscillating impulse voltages. The breakdown voltage-time characteristics and the breakdown voltage-pressure characteristics are measured over a pressure range extending from 0.1 to 0.5 [MPa] fur the coaxial electrode with a needle protrusion. The curvature radius of needle protrusion is 0.3[mm]. Also, the growth of the predischarge is simultaneously observed. As a result the polarity effect is pronounced, and the breakdowns voltage under the oscillating impulse voltage are higher than those under the lightning impulse voltage. It is found that the breakdown mechanism md predischarge phenomena ate closely related with the polarity and waveforms of the testing voltage.

• The korean journal of orthodontics
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• v.49 no.3
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• pp.194-201
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• 2019

When a patient shows severe crowding, premolar extraction should be considered to provide required available space for alignment. If the third molars have already erupted and demonstrate a poor prognosis, third molar extraction and distalization of the posterior dentition can be used instead of premolar extraction to obtain space. Interproximal stripping (IPS) may also be used to gain space in cases of crowding. This case report describes the treatment of a 25-year-old man with severe crowding and mild lip protrusion. Although the crowding in the lower arch was severe enough to require first premolar extraction, distalization of the entire lower dentition with orthodontic mini-implants, extraction of the lower third molars, and IPS could successfully resolve the crowding and lip protrusion.

• Journal of information and communication convergence engineering
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• v.21 no.3
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• pp.233-238
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• 2023

This study presents a method for identifying partial discharge defects in an eco-friendly gas insulated system using a backpropagation algorithm. Four partial discharge (PD) electrode systems, namely, a free-moving particle, protrusion on the conductor, protrusion on the enclosure, and voids, were designed to simulate PD defects that can occur during the operation of eco-friendly gas-insulated switchgear. The PD signals were measured using an ultrahigh-frequency sensor as a nonconventional method based on IEC 62478. To identify the types of PD defects, the PD parameters of single PD pulses in the time and frequency domains and the phase-resolved partial discharge patterns were extracted, and a back-propagation algorithm in the artificial neural network was designed using a virtual instrument based on LabVIEW. The backpropagation algorithm proposed in this paper has an accuracy rate of over 90% for identifying the types of PD defects, and the result is expected to be used as a reference database for asset management and maintenance work for eco-friendly gas-insulated power equipment.

• The Journal of the Korean dental association
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• v.33 no.8 s.315
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• pp.536-537
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• 1995

• The Journal of Korea Assosiation for Disability and Oral Health
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• v.10 no.1
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• pp.43-46
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• 2014

Cerebral Palsy is a genetic term referring to abnormalities of motor control caused by damage to a child's brain early in the course of development. Due to the impairment of balanced perioral muscle development, the prevalence of malocclusions in patients with cerebral palsy such as maxillary protrusion is high. But most clinicians may feel uncomfortable to treatment of these problems. Here a case report about mitigation of maxillary anterior teeth protruded in patient with cerebral palsy. 8y 4m old boy who have cerebral palsy visited our dental hospital. He showed severely protrusive maxillary anterior teeth with mouth breathing and could not close his mouth. He and his mother wanted to improve dental and facial esthetic problem. Specially designed or modified intraoral fixed appliance and rubber elastic chain was used in the therapy. Treatment carried out for 8 months and we could observe maxillary incisor angle was improved and mouth breathing habit was stopped. In conclusion, modified fixed appliance therapy for the patients with cerebral palsy might be useful. Continuous rehabilitation training of lips should be followed after treatment to correct imbalance of muscle tone.

• Journal of radiological science and technology
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• v.22 no.1
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• pp.27-33
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• 1999

The classification of herniated intervertebral lumbar disc type is clinically important, as treatment method may be slightly different according to the type of herniated intervertebral disc. When 450 patients who suffered from herniated intervertebral lumbar disc were tested with Magnetic Resonance Imaging (MRI) to find out the type of herniated disc, the following findings were given : 1. The age of the patients investigated ranged from 15 to 83, and their mean age was 40. 2. The male patients were twice as many as the female patients, since the ratio of males to females was 300 : 150. 3. 118 patients suffered from a single herniated disc, and 332 patients were attacked with multi-herniated disc. 4. The types of single herniated disc were a protrusion for 50 patients (40%) and an extrusion for 40 patients (34%). The part of being herniated was an intervertebral disc between $L_4-L_5$ for 95 patients(80%) and the same disc between $L_5-S_1$ for 22 patients(19%). 5. The types of multi : -herniated disc were an protrusion for 67 patients(20%) and an extrusion for 70 patients(21%). Besides, 90 patients (28%) were the case that protrusion and extrusion coexisted simultaneously. The parts of being herniated were $L_3-L_4,\;L_4-L_5$ and $L_5-S_1$ for 53 patients(16%), $L_3-L_4$ and $L_4-L_5$ for 57 patients(17%), and $L_4-L_5$ and $L_5-S_1$ for 139 patients(42%).

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.34 no.5
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• pp.537-542
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• 2008

BSSRO is most frequently operated among orthognathic surgery techniques for repairment of maxillofacial deformities. In case of patients with maxillofacial asymmetry accompanying mandibular protrusion who are operated by BSSRO, this study considers the recovering time for masticatory force of each tooth and Masseteric EMG and the adequate time enabling normal occlusion. The patients who are operated with BSSRO under general anesthesia in Dankook Dental Hospital, Department of OMS are selected for this study. The control group is devided into 2. 26 patients with facial asymmetry accompanying mandibular protrusion are selected for group 1 and their maximum voluntary bite force and masseteric EMG are measured. Group 2 is formed by volunteers with healthy dentition who are measured maximum bite force and masseteric EMG on both sides of the mouth. At the week of 3rd, 5th, 7th, 9th and 11th, Mann-Whitney U test is carried on for statistical analysis and the result is as follows. 1. Patients with mandibular protrusion showed apparently low maximum bite force and masseteric EMG than patients with normal occlusion. 2. In comparison with control group 1, Occlusal force is regained in incisors and canines at the 9th week and in premolars and molars, 11th week and masseteric EMG is regained at 11th week. 3. Comparing to normal occlusal patients, no recovery could be found in experimental group in every parts of the mouth.

• Archives of Plastic Surgery
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• v.45 no.5
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• pp.411-417
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• 2018

Background Accessory auricles (AAs) are common congenital anomalies. We present a new classification according to location and shape, and propose a system for coding the classifications. Methods This study was conducted by reviewing the records of 502 patients who underwent surgery for AA. AAs were classified into three anatomical types: intraauricular, preauricular, and buccal. Intraauricular AAs were divided into three subtypes: intracrural, intratragal, and intralobal. Preauricular AAs were divided into five subtypes: precrural, superior pretragal, middle pretragal, inferior pretragal, and prelobal. Buccal AAs were divided into two subtypes: anterior buccal and posterior buccal. AAs were also classified according to their protrusion pattern above the surrounding surface: pedunculated, sessile, areolar, remnant, and depressed. Pedunculated and sessile AAs were subclassified as spherical, ovoid, lobed, and nodular, according to their body shape. Cartilage root presence and family history of AA were reviewed. A coding system for these classifications was also proposed. Results The total number of AAs in the 502 patients was 1,003. Among the locations, the superior pretragal subtype (27.6%) was the most common. Among the protrusion patterns and shapes, pedunculated ovoid AAs were the most common in the preauricular (27.8%) and buccal areas (28.0%), and sessile lobed AAs were the most common in the intraauricular area (48.7%). The proportion of AAs with a cartilage root was 78.4%, and 11% of patients had a family history. The most common type of preauricular AA was the superior pretragal pedunculated ovoid AA (13.2%) with a cartilage root. Conclusions This new system will serve as a guideline for classifying and coding AAs.

• Journal of the korean academy of Pediatric Dentistry
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• v.11 no.1
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• pp.41-56
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• 1984

The purpose of this study is to obtain the normal range of mandibular movement for 13 year old boys and girls, and to compare it to the range of mandibular movement of class III patient and normal adult for diagnosis and prognosis of class III malocclusion and TMJ dysfunction. The subjects were 20 normal boys 20 normal girls 22 class III boys and 18 class III girls. The author measured the ranges and shapes of movement of the mandible in the frontal, sagittal and horizontal trajectories using Saphon visitrainer C II (Tokyo Shizaisha Inc.) for the subjects. The results obtained are as follows: 1) The mean for maximum right laterotrusion in the frontal trajectory were 11.96mm in N.B., 11.10mm in N.G., 11.32mm in III. B., 11.24mm in III G. The mean for maximum left laterotrusion were 11.48mm, 11.0mm, 10.91mm, 10.44mm respectively, Area of border movement were 7.16cm in N.B., 6.59cm in N.G., 7.29cm in III. B., 7.50cm in III. G. 2) The mean for maximum protrusion in the sagittal trajectory were 11.7mm in N.B., 11.4mm in N.G.,11.87mm in III B., and 11.02mm in III. G. 3) The mean for maximum protrusion in the horizontal trajectory were 10.20mm in N.B.,10.00 mm in N.G., 9.12mm for III. B. and 9.36mm in III. G. 4) The mean for maximum protrusion of Class III subjects were shorter than those of normal subjects. 5) There was no sexual difference in the range of mandibular movement for 13 year old subjects. N.B; Normal boys N.G.; Normal girls III.B.; Class III boys III. G.; Class III girls.