• The korean journal of orthodontics
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• v.36 no.3 s.116
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• pp.228-236
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• 2006

To evaluate the cephalometric and dental characteristics of obstructive sleep apnea (OSA) patients, 23 OSA patients and 15 control, non-OSA, patients who visited the Sleep Disorder Clinic Center, Keimyung University were investigated. Patients who suffered from apnea-hypopnea episodes over 10times per hour were diagnosed as having OSA after polysomnograph testing, Impressions were taken with alginate. Cephalometric radiographs were taken at maximum intercuspation. The dental cast measurements, including transpalatal width, intercanine width, intermolar width and palatal depth did not differ between the control and OAS groups and did not have a positive correlation with the apnea-hypopnea index (AHI). Upper airway width was statistically narrower than the control group. Upper airway width had a low negative correlation with AHI, but, lower airway width had a low positive correlation, and, the higher the AHI score, the longer the mandibular border to hyoid distance.

• Journal of the Korea Society of Computer and Information
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• v.14 no.6
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• pp.1-10
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• 2009

Flash memory has the advantages of nonvolatile, low power consumption, light weight, and high endurance. This enables the flash memory to be utilized as a storage of mobile computing device such as PMP(Portable Multimedia Player). Potable device with a mass flash memory can store various multimedia data such as video, audio, or image. Typical index systems for mobile computer are inefficient to search a form of text like lyric or title. In this paper, we propose a new text index system, named EMTEX(Embedded Text Index). EMTEX has the following salient features. First, it uses a compression algorithm for embedded system. Second, if a new insert or delete operation is executed on the base table. EMTEX updates the text index immediately. Third, EMTEX considers the characteristics of flash memory to design insert, delete, and rebuild operations on the text index. Finally, EMTEX is executed as an upper layer of DBMS. Therefore, it is independent of the underlying DBMS. We evaluate the performance of EMTEX. The Experiment results show that EMTEX can outperform th conventional index systems such as Oracle Text and FT3.

• Imaging Science in Dentistry
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• v.30 no.4
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• pp.235-242
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• 2000

Purpose: To evaluate the effect of the systemic osteoporosis on radiographic density of alveolar bone and cortical thickness of mandible. Materials and Methods: The bone mineral density values of lumbar and femur were measured by dual-energy X-ray absorptiometry and T scores of lumbar, femur were obtained respectively. Radiographic densities of alveolar bones and panorama mandibular index (PMI, represents as cortical thickness) were analysed statistically according to age and T score variables. Results: The radiographic density of alveolar bone of maxillary molar showed significant difference by age and femur T group. That of mandibular molar showed significant difference between femur T group. Panorama mandibular index showed significant difference between age groups. Conclusion: The radiographic density of alvealar bones was more dependent on age and femur T than lumbar T. Cortical thickness of mandible was correlated with increasing age.

• Proceedings of the Korea Information Processing Society Conference
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• 2019.05a
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• pp.556-558
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• 2019

기존 초음파 지방간 분석은 Hepatorenal sonographic index(HI)를 사용하여 지방간을 진단하여 왔다. 이러한 HI 기법에서는 Hepato(간)과 Renal(신장), 두 부분의 영상데이터를 비교 활용하였다면, 본 논문에서는 신장의 영상데이터만을 이용하여, 이의 통계적 특징 벡터만을 활용하여 지방간을 진단을 함으로서 기존의 HI기반 분석대비 편리성과 정확도를 개선코자 Kidney Index(KI) 기반의 분석 기법을 제안한다. 본 논문에서 제안된 KI는 정상간과 지방간을 가진 실제 환자의 초음파 사진(정상간, 지방간 각 30명)을 학습 데이터를 구성하고, 이들 데이터군으로부터 특징 벡터들을 선별하여 머신러닝 기법 중 서포트 벡터 머신(Support Vector Machine)을 통해 학습시켜, 제안된 알고리즘의 유효성을 입증하였다.

• Journal of Oral Medicine and Pain
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• v.38 no.2
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• pp.203-213
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• 2013

Objecives : The purpose of the study was to evaluate treatment outcome of mandibular advancement device(MAD) in obstructive sleep apnea (OSA) patients using full night polysomnography and cephalometry. Methods : Twenty-seven OSA patients were confirmed by full night, lab-attended polysomnography. Cephalometric examinations were conducted to obtain SNA, ANB, $AH{\bot}MP$, AH-C3, SPT, PNS-U, NAS, SOAS, MOAS, and HAS. Mandibular advancement devices (MADs) were fabricated and delivered for all subjects. After acclimation period of MAD, the second polysomnographic examinations were conducted in the same manner. Polysomnographic variables were compared between before and after MAD placement. Also, correlation coefficients were calculated between apnea-hypopnea index (AHI) and each item of cephalometric parameters. Results : There were significant improvements in total AHI, lowest $SpO_2$, and total arousal index after MAD therapy. Also, there were significant improvements in NREM $SpO_2$ and NREM AHI, but not in REM $SpO_2$ and REM AHI with MAD. Stratifying the sleep stage, there were significant decrease in stage I and significant increases in stage II and REM, but change in stage III was not significant. SNA and SOAS were significantly correlated with total AHI and NAS was significantly correlated with supine AHI. ANB was significantly associate with the effect of MAD. Conclusions : MAD is an effective treatment in OSA patients comparing polysomnographic variables before and after treatment. Cephalometric examination can be useful to evaluate OSA patients and predict treatment outcome of MAD.

• Journal of Technologic Dentistry
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• v.23 no.1
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• pp.95-106
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• 2001

The purpose of this study was to show the method of three-dimensional morphometry developed recently and to compare the accuracy of three-dimensional morphometry with those of PA cephalometry, The three-dimensional morphometry analysis program and device were developed. Steel balls (1.2mm in diameter) were attached in twenty five landmarks of artificial human skull. This artificial human skull was used as experimental materials. From three-dimensional morphometry and PA cephalometry of artificial human skull. eleven linear measurements were acquired and made into asymmetry index. Right-left differences of measurements were used as asymmetry index. These measurements and asymmetry index were compared respectively with those of actual. The results were as follows: 1. Mean difference between three-dimensional morphometry and actual artificial human skull in linear measurements was $1.99{\pm}0.37mm$, and mean difference between PA cephalometry and actual was $21.12{\pm}0.45mm$. Both of all were reduced more than those of actual. 2. Mean difference between three-dimensional morphometry and actual artificial human skull in asymmetry index was $0.07{\pm}0.42$, and mean difference between PA cephalometry and actual was $3.63{\pm}0.60$. Three-dimensional morphometry was reduced while PA cephalometry was magnified more than that of actual. 3. Each eleven asymmetry index of three-dimensional morphometry was the same negative sign as those of actuals while only N-Z, ANS-J, Tr-Go, Tr-ANS asymmetry index were the same in PA cephalometry. These results suggest that the method of three-dimensional morphometry is more accurate than those of PA cephalometry in asymmetry analysis.

• Journal of Digital Convergence
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• v.12 no.1
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• pp.511-518
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• 2014

The purpose of this study is to produce and distribute a smart device based educational application for culinary practice. This study was performed from Jul. 1 to Dec. 30, 2012. The design of the application is composed of the theoretical contents, making methods, practice video and evaluation questions of Western cuisine among the contents of the culinary practice education. In addition, the notice and Q&A were added for the interaction between teachers and learners. For this study, 31 main dishes' pictures, 155 pictures for making processes by menu, 31 recipes, 31 cooking tips, 372 evaluation questions and 31 cooking videos about 31 menus were produced. The contents produced as above were directly inserted at 'http://kongju-fn.dslink.co.kr/super/index.html' to produce the application. This application can be found through searching with the word of 'yoribaksa'. This study can be considered to be significant in that this application was produced in the situation of the absence of any other previous applications for culinary practice education.

• Journal of the Korean Geotechnical Society
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• v.37 no.7
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• pp.35-42
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• 2021

An experimental study was carried out on kaolinite-sand mixtures with various proportions of kaolinite content. To investigate physical behaviour of mixtures, index properties and compaction test results were analysed in various aspects. Moreover, to clearly see the interaction between kaolinite and sand particles, the observational analysis through microscopic image analysis device was conducted. The test results showed that an increase in the amount of kaolinite could create a strong bonding structure which resulted in higher specific surface available for activities of kaolinite particles. Also, an increase in the amount of the kaolinite resulted in an increase in the percentage of water sorption. Then it could accelerate the occupation rate of water which tended to take up the space that would have been occupied by solid particles, and accordingly, resulted in the decreased maximum dry unit weight and increased initial void ratio. Based on the microscopic image analysis, the samples were individually classified into three types of mixture such as sand dominant, intermediate fine content, and fine dominant. In addition, the fine and coarse grains seem to interact well in the mixtures with the fine content ranging from 25 to 40%.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.27 no.2
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• pp.157-161
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• 2001

The purpose of this study cephalometrically evaluated changes in the posterior airway space for patients with obstructive sleep apnea syndrome(OSAS) before and after surgical advancement of the maxilla and mandible. The change in calculated airway resistance was correlated with the respiratory disturbance index(RDI). Twenty cephalometric radiographs were traced before and after surgery to determine the posterior airway area and calculate resistance. Polysomnograms of each patient were obtained before and after surgery. All patients had a decrease in calculated airflow resistance in the airway. The mean amount of resistance was 865.15 before surgery, decreasing to 192.65 after surgery (p<0.01). Eighty-five percent of the patients experienced improvement in their RDI. Reduction in the RDI appears to be due to an increase in the posterior airway space and decrease in flow resistance.

• Journal of Oral Medicine and Pain
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• v.26 no.4
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• pp.369-376
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• 2001

Objectives : The purposes of the study was to evaluate cephalometric characteristics in snorers and patients with obstructive sleep apnea (OSA) and to see any relationships between the cephalometric measurements and respiratory disturbance indices (RDI). Materials and Methods : Twelve snoring patients, 11 patients with OSA, and 10 normal subjects were included for the study. After taking a screening sleep study for a night to obtain RDI, $SaO_2$, and snoring index, a detailed cephalometric analysis was conducted to obtain SNA, SNB, SN-MP, IAS, MAS, SPAS, SAAS, Mn-H, and PNS-P. All the data were compared between groups. For a group including 12 snoring patients and 11 OSA patients, correlation coefficients were calculated between respiratory disturbance index and each item of cephalometric measurements. Results : The mandible and the maxilla are retropositioned. The oropharyngeal and hypopharyngeal airway is reduced in area and is a factor that could produce or enhance OSA symptoms. The hyoid bone is displaced inferiorly. The soft palate is significantly elongated. Conclusions : These data suggest that cephalometric evaluation could be useful to evaluate snoring and OSA patients, and to assist with the planning treatment for improvement of upper airway patency.