• 치과방사선
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• 제28권1호
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• pp.111-126
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• 1998

In this study, radiographic evaluation was made using panoramic radiography and cross-sectional tomography of SCANORA/sup (R)/ in male and female adults in their 20's on the relationship between the maxillary sinus floor and the apex of the maxillary molar, to test the accuracy and effectiveness of the cross-sectional tomography, and to use this information in the assessment of preop. and postop. root canal treatment, apical surgery, extraction and implantology. Forty-one adults with an average age of 24.4 years were studied using panoramic radiography and cross-sectional tomography. In panoramic view and cross-sectional view, the position of the apices of maxillary molars were classified as separated, contacted, or protruded type; the general shape of the maxillary sinus floor was evaluated horizontally and vertically from cross-sectional tomography. The accuracy of each radiography was tested using maxilla from 5 fresh cadavers from the Anatomy Lab at Yonsei University Dental College, and panoramic view and cross-sectional tomography were taken in the same condition as with the patients. The results were as follows: 1. Panoramic view and cross-sectional view were taken in the maxilla specimen, and the actual distance between the maxillary sinus floor and the tooth apices were measured in the specimen; the median values of the distance from the tooth apices to the maxillary sinus floor in the panoramic view, cross-sectional view and in the actual maxilla specimen were 2.83 mm, 4.51mm, and 4.l5mm, respectively. In the cross-sectional view, the measured distance was close to the actual distance but in the panoramic view, the measured distance was far from the actual distance. 2. When the results of the panoramic view and cross-sectional view were compared, 40.5％ of the results agreed with each other in the two radiographic methods and buccal roots of the 2nd molar were the closest to the maxillary sinus floor in the cross-sectional tomography. 3. In cross-sectional view, when the vertical relationship of the maxillary sinus floor and maxillary roots was assessed, in 1st molars, type II (the sinus floor that extends down to the buccolingual furcation area) was predominant, while in 2nd molars, type I (the sinus floor located above the level connecting the buccal and lingual apices) was predominant. In the horizontal relationship, in 1st molars, type II (the lowest floor of the maxillary sinus located in between the buccal and lingual roots) was predominant; in 2nd molars, type I (the lowest floor of the maxillary sinus located on the buccal side of the buccal roots) and type II appeared in similar frequency. In conclusion, the SCANORA/sup (R)/ cross-sectional tomography was more effective than the frequently used panoramic view, in that the relationship of the maxillary molars and maxillary sinus floor can be evaluated more accurately and the buccolingual cross-sectional view can also be observed. And maxillary sinus floor that was close to maxillary 2nd molar had tendency to be located on buccal side than that close to 1st molar. Therefore, cross-sectional tomography is an effective and accurate method to evaluate the position of the teeth in relation to the sinus floor preoperative and can be easily used to diagnose localized periapical lesions. Also, the image quality obtained was quite satisfactory.

• 대한치과교정학회지
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• 제28권1호
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• pp.29-41
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• 1998

교정치료란 동적인(dynamic)진료행위 임에도 불구하고 치료를 위해 사용하는 교정장치의 효과를 평가하는데 있어서는 정적인(static) 방법이 주로 이용되어왔다. 대부분의 교정의들은 동일한 치료목표를 위해 여러 종류의 장치가 제시될때 과연 어떠한 장치가 상대적으로 치료결과 및 치료기간 면에서 상대적으로 더 우수한가를 알고 싶어한다. 이에 본 저자들은 구치부 교차교합 해결을 위해 사용하고 있는 PLA중 Burstone식 PLA(single force응용)와 구치직립식 PLA(couple기전 응용) 간의 치아이동 기전과 치아이동 시간의 상대적 차이를 규명하고 얻어진 결과를 임상에 적용하기 위하여 본 교실에서 개발, 제작한 Calorific machine을 이용하여 실험한 후 정상치와 경사치의 이동양상과 치아이동시간을 계측하여 paired t-test를 한 결과 다음과 같은 결론를 얻었다. 1. 구치직립식 PLA가 Burstone식 PLA 보다 경사치의 정출량과 치근의 수평이동량이 더 큰것으로 나타났다(p=0.0000). 2. 구치직립식 PLA 사용시 정상치 (upright molar)의 치아이동은 없는 것으로 나타났으나(P=0.3475) Burstone식 PLA는 미미한 양(0.2mm)이지만 있는 것으로 관찰되었다(p=0.0001). 3. 경사치의 치아이동시간이 Burstone식 PLA의 경우 약 17.8분 정도 소요되었으나 구치직립식 PLA는 3.8분으로 나타났다(P=0.0001).

• 치과방사선
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• 제28권1호
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• pp.225-234
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• 1998

We used five adult dog mandibles embedded in resin block and six different cross-sectional planes for each mandible were choosen. According to the angle of mandibular occulsal plane to vertical plane(mandibular angle) and gantry angle of CT machine, we classified 4 experimental groups and 1 control group. The control group images were taken at the mandibular angel 0° and gantry angle 0°. The experimental images were taken at the mandibular angle 15° and gantry angle 0°(group 1); 30° and 0°(group 2); 15° and 15°(group 3) ;30° and 30°(group 4), respectively. Using the reformatted cross-sectional images, the distance from the mandibular canal to the alveolar crest and the distance from the mandibular canal to the buccal cortex and to the lingual cortex was measured and compared. The obtained results were as follows: 1. The distance from the mandibular canal to the alveolar crest of group 1 and 2 was larger than control group, but the distance of group 3 and 4 was smaller. The distance from the mandibular canal to the buccal cortex and to the lingual cortex of all experimental groups was smaller than control group. 2. The distance from the mandibular canal to the alveolar crest showed the largest difference from control group in all experimental groups, especially in group 2 and 4(p<0.05). 3. In the distance from the mandibular canal to the alveolar crest, the number of deviation value under 1 mm was 20 in group 3 and was 11 in group 2 and 4, respectively. 4. The deviation value of the distance from the mandibular canal to the buccal cortex and to the lingual cortex was under 1 mm in most cases.

• Journal of Information Processing Systems
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• 제18권4호
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• pp.535-548
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• 2022

Using a rich resource language to classify sentiments in a language with few resources is a popular subject of research in natural language processing. Burmese is a low-resource language. In light of the scarcity of labeled training data for sentiment classification in Burmese, in this study, we propose a method of transfer learning for sentiment analysis of a language that uses the feature transfer technique on sentiments in English. This method generates a cross-language word-embedding representation of Burmese vocabulary to map Burmese text to the semantic space of English text. A model to classify sentiments in English is then pre-trained using a convolutional neural network and an attention mechanism, where the network shares the model for sentiment analysis of English. The parameters of the network layer are used to learn the cross-language features of the sentiments, which are then transferred to the model to classify sentiments in Burmese. Finally, the model was tuned using the labeled Burmese data. The results of the experiments show that the proposed method can significantly improve the classification of sentiments in Burmese compared to a model trained using only a Burmese corpus.

• Journal of Periodontal and Implant Science
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• 제23권1호
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• pp.159-169
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• 1993

The thirty six mandibular second molars, which were extracted because of hopeless tooth due to advanced periodontal disease, were measured the length of mesial and distal root and the distance from cementoenamel junction to root separation. The molars were cross-sectioned every 1.5 milimeter from cementoenamel junction to root apex perpendicular to long axis and each section was photographed, projected and measured with a calibrated Digital Curvi-Meter(Com Curvi-8. Japan). The root surface area (RSA), percentage of the RSA and the linear variation of the RSA were calibrated for each 1. 5 mm section. The results were as follows. 1. The mean length of the roots was 12. 98mm for mesial root, 11.84 mm for distal root. The mesial root was longer than distal root.(p<0.01) 2. The mean distance from the cementoenamel junction to the point at which the root separate from the root trunk was 3.82mm for the buccal furcation and 4.75mm for lingual furcation. The buccal root separation was coronal than the lingual root separation.(p<0.01) 3. The total root surface area was $317.78mm^2$. 4. The mean surface area of the root trunk was $150.06mm^2$ and averaged 42.54% of the total root surface area. 5. The mean root surface area was $88.79\;mm^2$ for the mesial root, $78.93mm^2$ for distal root, The mesial root surface area was wider than the distal root surface area.(p<0.05) 6. In comparision, the mean root trunk surface area of the mandibular 2nd molar was wider than that of mandibular 1st molar(p<0.01), but each root of 2nd molar was smaller than that of 1st molar(p<0.01).

• 한국정보과학회:학술대회논문집
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• 한국정보과학회 2005년도 한국컴퓨터종합학술대회 논문집 Vol.32 No.1 (B)
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• pp.448-450
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• 2005

교차언어검색 시스템은 다양한 언어자원을 필요로 한다. 여기서는 한-일 대역어 사전과 일본어 문서의 바이그램 색인만을 이용해서 교차언어검색을 수행하는 방법을 제시한다. 한국어로 된 자연어 질의에서 형태소분석기 등의 도움 없이 간단하게 일본어 대역어 리스트를 생성할 수 있는 방법과, 검색의 성능을 올릴 수 있도록 대역어에 가중치를 부여하는 방법을 제안한다. 그리고 실험을 통해 제시한 방법을 평가하고 분석한다.

• International Journal of Control, Automation, and Systems
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• 제5권1호
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• pp.99-103
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• 2007

Translation equivalence is very important for bilingual lexicography, machine translation system and cross-lingual information retrieval. Extraction of equivalences from bilingual sentence pairs belongs to data mining problem. In this paper, discriminative learning methods are employed to filter translation equivalences. Discriminative features including translation literality, phrase alignment probability, and phrase length ratio are used to evaluate equivalences. 1000 equivalences randomly selected are filtered and then evaluated. Experimental results indicate that its precision is 87.8% and recall is 89.8% for support vector machine.

• 대한구순구개열학회지
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• 제13권2호
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• pp.43-52
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• 2010

Intraoral prosthesis (Palatal Augmentation Prosthesis, PAP) may be used to augment swallowing function in patients with dysphagia. PAP can be used to recontour the dimensions of hard palate to fit the tongue following removal of oral cancer. Use of PAP can significantly improve the patient's ability to use the tongue to propel the bolus through the pharynx. The aim of this study is to show the effects of PAP through videofluoroscope in patients with dysphagia. The results were as follows: 1. A decrease in pharyngeal transit time was detected wearing with PAP. 2. Pharyngeal cross area was decreased wearing with PAP. 3. The results indicated PAP may effectively help lingual movement in patients with dysphagia.

• 한국정보처리학회:학술대회논문집
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• 한국정보처리학회 2012년도 추계학술발표대회
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• pp.658-661
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• 2012

국제적으로 이슈가 되고있는 사건들의 뉴스는 보도당국의 입장차이에 따라 동일 이슈에 대한 관점의 차이를 나타낸다. 교차언어 연구에서는 번역하는 과정이 중요하다. 본 논문에서는 중-한 어휘번역에서 발생하는 오류 및 모호성을 해결하기 위해 키워드를 중심으로 문맥 어휘를 이용해서 번역한 후 번역결과에서 빈도가 높은 한국어 어휘를 선택하는 방법을 제안한다. 제안 방법의 유효성을 검증하기 위해 소셜 이슈 3 개에 대한 트윗 데이터에서 실험하여 추출된 중-한 이슈 뉴스 결과에서의 정확도 85.8%의 성능을 보였다. 실험을 통해 제안 방법이 중-한 교차언어 트위터 데이터에서 동일한 이슈와 관련된 뉴스를 찾는데 효과적인 방법임을 알 수 있다.

• 대한치과교정학회지
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• 제19권2호
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• pp.130-143
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• 1989

FR III에 의해 전치부 반대교합이 개선된 성장기 반대교합자 7명을 대상으로 치료전과 전치부 반대교합개선 즉시의 측모두부방사선 규격사진 및 모형을 분석 검토한 결과를 다음과 같이 요약할 수 있으나, 악골형태, 성장형태, 부정교합상태등에 따라 아주 다양한 결과를 나타내어 FR III에 의한 악안면의 변화를 한마디로 요약하는 것은 상당히 힘든 것으로 사료된다. 1. 상악골은 미약한 전상방으로의 회전 경향과 전방성장을 보였다. 2. 하악골은 개체간의 차이는 있으나 미약한 수직적 위치변화와 함께 하안면고가 증가되었다. 3. 상악전치는 치체이동 또는 순측경사되었다. 4. 모든 증례에서 하악전치는 설측경사를 보였다. 5. 상악치열궁 폭경은 증가되었으며, 하악치열궁 폭경은 개체간의 차이는 있으나 대체적으로 거의 변화되지 않았다.