• Korean Journal of Computational Design and Engineering
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• v.4 no.1
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• pp.32-42
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• 1999

Approximate lofting or skinning is one of practical surface modeling techniques well used in CAD and reverse engineering applications. Presented in this paper is a method for approximately lofting a given set of curves wihin a specified tolereance. It is based on refitting input curves simultaneously on a common knot vector and interpolating them to get a resultant NURBS surface. A concept of reducing the number of interior knots of the common knot vector is well adopted to acquire more compact representation for the resultant surface. Energy minimization is newly introduced in curve refitting process to stabilize the solution of the fitting problem and get more fair curve. The proposed approximate lofting provides more smooth surface models and realizes more efficient data reduction expecially when the parameterization and compatibility of input curves are not good enough. The method has been successfully implemented in a new CAD/CAM product VX Vision? of Varimetrix Corporation.

• Journal of the Korean Institute of Telematics and Electronics D
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• v.34D no.2
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• pp.1-9
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• 1997

For the reduction of parasitic inductance and matching of bonding wire in the package of microwave devices, we propose multiple bonding wires buried in a dielectric material of FR-4 composite. This structure is analyzed using the method of moments (MoM) and compared with the common bondwires and ribbon interconnections. The FR-4 composite is modelled by the cole-cole model which can consider the loss and the variation of the permittivity in a frequency. At 20 GHz, the parasitic reactance is reduced by 90%, 80%, 60% compared to those of a single bonding wire in air, double bonding wires in air and ribbon interconnection in air, respectively. Also, the new bondwire shows very good matching of 60.ohm characteristic impedance and has 15dB, 10dB, 5dB improvement of the return loss and 2.5dB, 0.7dB, 0.2dB improvement of the insertion loss compared to the common interconnections. This technique can minimize the parasitic effect of bondwires in microwave device packaging.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.27 no.2
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• pp.87-90
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• 2016

Cough, the most common symptom, encountered in the outpatient clinic can be caused by various underlying diseases. It defines as chronic cough that the duration of cough is more than 8 weeks with a normal chest X-ray findings. The cause of cough can be found out for more than 90% through the appropriate diagnostic approach and Upper airway cough syndrome, Asthma and Gastroesophageal reflex disease are the most common causes of disease to non-smokers. Chronic cough can be due to not one reason but various reasons and achieve good results by a systematic approach to diagnosis and a concrete treatment on the basis of the sufficient understanding of the underlying disease.

• Korean Journal of Head & Neck Oncology
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• v.30 no.2
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• pp.71-73
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• 2014

Pleomorphic adenoma is the most common benign mixed salivary gland neoplasm that accounts for 65% of all benign salivary glands tumors. While the majority arises from the parotid, only a 10% arises from the minor salivary glands. Pleomorphic adenoma of minor salivary gland in the palate is a common entity. However, they occur in the lip, cheek, tongue oropharynx and nasal cavity etc., rarely. We experienced a case of a 80 years old female presented a 10 years history of a right cheek mass which was proved to the pleomorphic adenoma on the histopathologic examination. We resected the mass and obtained good postoperative results. We report this case with a review of literature.

• Proceedings of the KOR-BRONCHOESO Conference
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• 1983.05a
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• pp.14.1-14
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• 1983

The most common cause of the decannulation difficulty is the trauma. This may be accidental, iatrogenic such as prolonged intubation, high tracheostomy, secondary infection, formation of granulation tissue, improper use of cannula and wide resection of anterior tracheal wall. Another common cause is psychologic dependency. Treatments may be categorized into dilatation with or without injection of steroid, dilatation and prolonged stent, luminal augmentation and resection of the stenosis with primary reanastomosis. Recently authors experienced a case of the decannulation difficulty in a 2 - year - old which was developed after tracheostomy for the removal of bronchial foreign body and was treated with a silicon T -tube stent with good result.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.6 no.1
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• pp.27-38
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• 1995

It is well known that unilateral vocal cord paralysis is a sign of a disease and not a disease entity. In an attempt to evalute incidence of unilateral vocal cord paralysis related to varoius causes and to analyze our treatment results, the records of 210 patients seen at the Department of Otorhinolaryngology, Yongdong Severance Hospital during the 10-year period from March 1985 to March 1995 were reviewed. Fifty-three patients(25.2%) of the 210 patients with unilateral vocal cord paralysis had surgery-related causes, and intubations including tracheostomy was the most common etilogy among them. One hundred and fifty seven cases(74.8%) was not related to surgery and, among these most common cause was idiopathic. Spontaneous recovery took place in 17(8%) patients. Phonosurgery including type Ⅰ thyroplasty(n=16) and arytenoid adduction(n=10) and combination of them(n=3) yielded good results except intrafold teflon injection(n=4). These results of our series were compared to other series reported over the past decades.

• Bulletin of the Korean Chemical Society
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• v.19 no.1
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• pp.45-50
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• 1998

Most organophosphorus pesticides may be metabolized to yield some common phosphates in human or in animals, and these metabolites may be used as the exposure biomarkers to pesticides. In this study, we developed the extraction method of four phosphate metabolites from the spiked human urine in high recovery by the solid phase extraction with a reverse-phase cartridge (cyclohexyl silica) followed by the elution with methanol. The extracted urinary metabolites were derivatized with hexamethyldisilazane/trimethyl-chlorosilane/pyridine (2 : 1 : 10, v/v/v) and identified by gas chromatography/mass spectrometry. Calibration curve obtained from each metabolite standard using by GC/MS/SIM has shown good linearity and detection limits of metabolites were the range of 0.05-0.1 ㎍/㎖ in urine. Phenthoate, one of the organophosphorus pesticides, was orally administrated to rats. Four metabolites were detected in the rat urine. The results of this study may be applied to development of exposure biomarkers for monitoring of environmental pollutants.

• Bulletin of the Korean Chemical Society
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• v.15 no.12
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• pp.1089-1093
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• 1994

Polyesters containing enaryloxynitriles moiety have been newly prepared from p-bis[1-[4-(3-hydroxypropyl)phenoxy]-2,2-dicyano vinyl]benzene (3) and common diols with terephthaloyl chloride. The copolyesters have a good solubility in common organic solvents as well as polar aprotic solvents. They undergo a curing reaction at around 350 $^{circ}C$ and show a 50-60${\%}$ of residual weight at 500 $^{circ}C$. The enhanced thermal stabilities were due to the intramolecular cyclization or intermolecular cross-linking reaction of the dicyanovinyl group incorporated into polyester by copolymerization.

• Journal of the Korean School Mathematics Society
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• v.9 no.3
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• pp.249-263
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• 2006

The purpose of this study is to investigate the characteristics of 'best practire' in mathematics and suggest some solutions to several problems emerging in mathematics classes of secondary schools. The study was carried out by using qualitative research methods such as class observations and in-depth interviews with six teachers. Based on the collected data, we could sort out the major patterns which characterize 'the good mathematics teaching' at schools in Korea. The common characteristics of best practice in mathematics are drawn out from the six cases. The common characteristics include revising the curriculum and text books, realistic mathematics education, using ICT and meta-cognition, introduction with motivation and interest, performance assessment and managing differentiated small group. Results implied that six teachers used a variety of instructional methods and strategies which is related with the common characteristics of good mathematics teaching. Also these teachers not only improved their own classroom practices but also participated in various professional community of mathematics education and shared their practical knowledge. In conclusion assorted efforts from the government and the school principals as well as the teachers are prerequisite for practicing and spreading good mathematics teaching across the classrooms.

• Journal of Korean Neurosurgical Society
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• v.60 no.5
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• pp.584-590
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• 2017

Objective : Traumatic brain injury (TBI) in children under age 24 months has characteristic features because the brain at this age is rapidly growing and sutures are opened. Moreover, children this age are completely dependent on their parents. We analyzed the demographic data and risk factors for outcomes in TBI patients in this age group to elucidate their clinical characteristics. Methods : We retrospectively reviewed the medical records and radiological films of children under 24 months who were admitted to Kyungpook National University Hospital from January 2004 to December 2013 for TBI. Specifically, we analyzed age, cause of injury, initial Glasgow coma scale (GCS) score, radiological diagnosis, seizure, hydrocephalus, subdural hygroma, and Glasgow outcome scale (GOS) score, and we divided outcomes into good (GOS 4-5) or poor (GOS 1-3). We identified the risk factors for post-traumatic seizure (PTS) and outcomes using univariate and multivariate analyses. Results : The total number of patients was 60, 39 males and 21 females. Most common age group was between 0 to 5 months, and the median age was 6 months. Falls were the most common cause of injury (n=29, 48.3%); among them, 15 were falls from household furniture such as beds and chairs. Ten patients (16.7%) developed PTS, nine in one week; thirty-seven patients (61.7%) had skull fractures. Forty-eight patients had initial GCS scores of 13-15, 8 had scores of 12-8, and 4 had scored 3-7. The diagnoses were as follows : 26 acute subdural hematomas, 8 acute epidural hematomas, 7 focal contusional hemorrhages, 13 subdural hygromas, and 4 traumatic intracerebral hematomas larger than 2 cm in diameter. Among them, two patients underwent craniotomy for hematoma removal. Four patients were victims of child abuse, and all of them had PTS. Fifty-five patients improved to good-to-moderate disability. Child abuse, acute subdural hematoma, and subdural hygroma were risk factors for PTS in univariate analyses. Multivariate analysis found that the salient risk factor for a poor outcome was initial GCS on admission. Conclusion : The most common cause of traumatic head injury in individuals aged less than 24 months was falls, especially from household furniture. Child abuse, moderate to severe TBI, acute subdural hematoma, and subdural hygroma were risk factors for PTS. Most of the patients recovered with good outcomes, and the risk factor for a poor outcome was initial mental status.