• The Journal of the Korea Contents Association
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• v.9 no.11
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• pp.289-296
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• 2009

In this study, I presented power control unit with potential use in the magnetic stimulation of biological systems. The effect of the magnetic stimulation depends on the geometry and orientation of the induced electric field as well as on the current pulse waveform delivered by the stimulator coil. TMS is achieved from the outside of the head using pulses of electromagnetic field that induce an electric field in the brain. There are numerous possibities in the applications TMS, such as diagnosis and therapy through the brain stimulation. These factors are very important to define the equipment requirements and characteristics in that the topology of the power supply and the size and geometry of the coil. The proposed solution is the generation of current pulses with variable amplitude and duration, according to a user defined input. Another solution is the topology that uses elements to store and transfer energy from the power source to the load. In addition to proposed topology, an adequate control strategy and right set of the power circuit parameters made possible to obtain unipolar waves and bipolar waves.

• The korean journal of orthodontics
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• v.38 no.6
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• pp.437-455
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• 2008

Condylar hyperplasia is a pathologic condition showing 3-dimensional skeletal hyperplasia of the mandible. The reason for condylar hyperplasia is not yet known, but the effects of hormone, trauma, infection, genetics, fetal condition, and hypervascularity are known as possible reasons. When we diagnose a patient as having condylar hyperplasia, it is important to decide if it is in progress or not. Treatment for facial asymmetry due to condylar hyperplasia are decided accordingly, including condylectomy, that is removal of growth site of the affected condyle, and conventional orthognathic surgery only or condylectomy with orthognathic surgery after the completion of growth. Therefore, it is important to determine the growth state of condylar hyperplasia in treatment stability. This is verified through bone scan and regular check-ups with 3D CT or PA cephalogram. This case report introduces an improved case of facial asymmetry with condylectomy together with orthognathic surgery.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.29 no.2
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• pp.135-139
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• 2003

A dentigerous cyst is an epithelium-lined sac that surrounds the crown of an unerupted tooth or odontoma. And the most common sites of this cyst are the mandibular and maxillary third molar and maxillary cuspid a areas. Clinically, expansion of bone with subsequent facial asymmetry, extreme displacement of teeth, severe root resorption of adjacent teeth and pain are all possible sequelae of this cyst. The standard treatment for a dentigerous cyst is enucleation and extraction of the involved tooth. But in large cysts, this can lead to functional, cosmetic and psychologic consequences to the patients. So recently, more conservative methods are used. We report 5 cases of dentigerous cysts in pediatric patient which were treated by a conservative approach, By this methods, we can preserve teeth and guide eruption of the teeth which are involved in cystic area.

• The Journal of Korean Academy of Prosthodontics
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• v.55 no.4
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• pp.444-450
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• 2017

Prosthetic decision-making is complex because of various factors, and involves a combination of the individual dentist's interpretation of the objective clinical data and his or her interaction with the patient. Increasing therapeutic options and emerging outcome data demand the constant re-evaluation of our decision-making process. In this case, fixed prosthetic restorations were selected as a treatment method to reconstruct the occlusal plane of a patient with disharmonious occlusal plane. And the occlusal plane was re-established by establishing a treatment plan through diagnostic wax-up. Provisional restorations obtained by continuous re-evaluation for a sufficient period of time was replicated to definitive restorations using CAD/CAM technology. The results were satisfactory when they were observed through clinical follow-up for 3 months after the end of treatment.

• Journal of the Korea Convergence Society
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• v.6 no.6
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• pp.131-137
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• 2015

To study the effects of oral health education on children, weekly education sessions and surveys were held for 214 preschoolers, 6-7 years of age, in 2 K-area kindergartens for 4 weeks in July 2015. Statistics on oral health behaviors such as children with regular dental checkups(p<0.05), children who underwent fluoride application(p<0.05), children without dental caries diagnosis(p<0.001), children with mothers who underwent oral health education(p<0.05) showed significant difference. Oral health knowledge scores(6 being perfect) increased from pre-education scores of 4.96 to post-education score of 5.54. oral health behavior scores(11 being perfect) also increased from pre-education scores of 7.18 to post-education score of 7.75(p<0.001). Therefore, it is the author's opinion that the development of oral health education programs with relatively short cycles, alongside systematic, practical, and repeated education would be beneficial.

• Journal of the Korean Data and Information Science Society
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• v.24 no.2
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• pp.267-275
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• 2013

Among data mining techniques, the association rule is the most recently developed technique, and it finds the relevance between two items in a large database. And it is directly applied in the field because it clearly quantifies the relationship between two or more items. When we determine whether an association rule is meaningful, we utilize interestingness measures such as support, confidence, and lift. Interestingness measures are meaningful in that it shows the causes for pruning uninteresting rules statistically or logically. But the criteria of these measures are chosen by experiences, and the number of useful rules is hard to estimate. If too many rules are generated, we cannot effectively extract the useful rules.In this paper, we designed a variety of non-linear regression equations considering all association thresholds between the number of rules and three interestingness measures. And then we diagnosed multi-collinearity and autocorrelation problems, and used analysis of variance results and adjusted coefficients of determination for the best model through numerical experiments.

• The Journal of Korea Assosiation for Disability and Oral Health
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• v.6 no.1
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• pp.10-14
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• 2010

Vitamin D-resistant rickets(VDRR) is hereditary disease manifesting marked hypophosphatemia caused by renal tubular loss of phosphate into urine and an associated decrease in the calcium and phosphorous ion product. VDRR is identified by clinical symptoms, such as in the limbs, gait disturbance, dwarfism, familial occurrence, bowlegs, and knock-knees, as well as by laboratory findings. Dental findings are enlarged chambers and extension of the pulp horns into the cusp tips in both the primary and the permanent dentition in contrast to the vitamin D-deficient rickets. The major oral manifestations are multiple spontaneous abscesses in a caries-free dentition. We reported the clinical features and treatment of a 6-year-old boy with vitamin D-resistant rickets referred to the department of pediatric dentistry in Kyung Hee University for multiple spontaneous periapical abscesses and gingival fistula without severe dental caries.

• Journal of The Korean Association For Science Education
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• v.19 no.2
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• pp.173-184
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• 1999

The longitudinal trend of elementary and secondary students' science process skills were investigated to monitor the progress of science learning. Science process skill test, developedin an earlier study on developing a national science process skills assessment system,was revised and administered for the study on March, 1999. Subjects were sampled nation wide according to sex and region. The results of this assessments were compared to those administered on February, 1997. The results showed little difference on science process skills among elementary school students. However, secondary students showed marked increase in science process skills. More systematic and long-term research for assessing science process skills should be planned and performed periodically to provide empirical and foundational data for educational policy making.

• Journal of the Korean Society for Nondestructive Testing
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• v.35 no.2
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• pp.128-133
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• 2015

This paper describes the construction of a static 3D ultrasonography image by tracking the radiation beam position during the handy operation of a 1D array probe to enable point-of-care use. The theoretical model of the transformation from the translational and rotational information of the sensor mounted on the probe to the reference Cartesian coordinate system was given. The signal amplification and serial communication interface module was made using a commercially available sensor. A test phantom was also made using silicone putty in a donut shape. During the movement of the hand-held probe, B-mode movie and sensor signals were recorded. B-mode images were periodically selected from the movie, and the gray levels of the pixels for each image were converted to the gray levels of 3D voxels. 3D and 2D images of arbitrary cross-section of the B-mode type were also constructed from the voxel data, and agreed well with the shape of the test phantom.

• Journal of Chest Surgery
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• v.31 no.7
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• pp.725-729
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• 1998

Endobronchial leiomyoma is extremely rare and accounts for less than 2% of benign tumors of the lower respiratory tract. Leiomyomas are predominantly found in the young and the middle aged : of the average age being 35 years for bronchial and lung parenchymal lesions and 40.6 years for tracheal lesions. The symptom depends on the location of the tumor, its size, and changes in the lung distal to the lesion. A 37-year-old woman was admitted to our hospital complaining of coughing. Bronchoscopy revealed complete obstruction of the right main bonchus at the carina by an oval-shaped, nonulcerative, smooth, and pinkish-tan tumor with a broad margin and extended to the left main bronchus. A biopsy was performed and showed a benign spindle cell tumor. A right pneumonectomy was performed because of chronic infection, and the lung could not expanded during aeration. The histological diagnosis of the resected specimen was leiomyoma. The postoperative course was uneventful.