• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제36권5호
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• pp.408-412
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• 2010

Introduction: This study examined the depth of sedation and the usefulness of the monitoring tool in determining the level of sedation in patients undergoing third molars extraction under conscious sedation with midazolam. Materials and Methods: Twenty two patients undergoing third molars extraction at the department of Oral and Maxillofacial surgery, Ewha Womans Mokdong Hospital from February 2010 to April 2010 were analyzed. All patients were classified as American Society of Anesthesiologist (ASA) class I and had no contraindications tosedation. The bispectral index was recorded continually during surgery using a bispectral monitor. The initial sedation was accomplished using a 3 mg bolus of midazolam followed by a 2 mg bolus of midazolam until the level of sedation, at which the patient’s eyes were closed or the subject was responsive only to loud or repeated calling of their name, was reached. All subjects were surveyed with a postoperative questionnaire to evaluate the level of sedation. Results: The bispectral index (BIS) decreased approximately 5 minutes after midazolam administration, but increased at the local anesthesia injection and odontomy procedure. The amnestic effect was shown effectively in the early stages of surgery. Conclusion: Conscious sedation with intravenous midazolam is effective in achieving the effect of anxiolysis, analgesia and amnesia. The BIS is an objective and useful means of assessing the depth of sedation.

• 한국지하수토양환경학회지:지하수토양환경
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• 제23권4호
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• pp.48-59
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• 2018

Beryllium (Be), cobalt (Co), thallium (Tl) and vanadium (V) are candidates of 21 priority soil pollutants in Korea. The distribution of their concentration in soils from three contamination sources including industrial, roadside and mining areas was investigated. Concentrations of the metals were evaluated quantitatively using pollution indices and the fractionation of metals was conducted using modified SM&T (Standards Measurements and Testing programme) sequential extraction. Concentrations of the metals for all samples from industrial and roadside soils were within the range of natural background levels, while some of Be in soils from abandoned mines exceeded that the range. Enrichment Factor (EF) and Nemerow Integrated Pollution Index (NIPI) for Be, Co, Tl and V showed that there are effects or possibilities of anthropogenic activities. Pollution Load Index (PLI) analyses indicated all investigated sites needed further monitoring. The results of sequential extractions indicated mobile fractions (F1+F2) of Be, Tl and V were below 30% except some of Co in soil, which implies their low mobility to neighboring environment media. Variable tools like sequential extraction, comparison with background/actual concentration and pollution indices, as well as aqua regia extraction should be considered when evaluating Be, Co, Tl, V in soil.

• 한국정보과학회논문지:데이타베이스
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• 제30권4호
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• pp.351-361
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• 2003

단어의 연관성을 이용하여 문서의 특징을 추출하는 기존의 방법은 주기적으로 프로파일을 갱신해야하는 문제점, 명사구를 처리해야 하는 문제점, 명사구를 처리해야 하는 문제점, 색인어에 대한 화률을 계산해야 하는 문제점 등을 포함한다. 본 논문에서는 연관 단어 마이닝을 사용하여 문서의 특징을 효율적으로 추출하는 방법을 제안한다. 제안한 방법은 Apriori 알고리즘을 사용하여 문서의 특징을 단일 단어가 아닌 연관 단어 백터로 표현한다. Apriori 알고리즘을 사용하여 문서의 특징을 단일 단어가 아닌 연관 단어 벡터로 표현한다. Apriori 알고리즘을 사용하여 문서로부터 추출된 연관 단어는 이를 구성하는 수와 신뢰도와 지지도에 따라 차이를 보인다. 따라서 본 논문에서는 문서 분류의 성능을 향상 시키기 위허ㅐ 연관 단어를 구성하는 단어의 수와 지지도를 결정하는 효율적인 방법을 제안한다. 연관 단어 마이닝을 이용한 특징 추출 방법은 프로파일을 사용하지 않으므로 프로파일 갱신의 필요성이 없으며, 색인어에 대한 확률을 계산하지 않고도, Apriori 알고리즘의 신뢰도와 지지도에 따라 자동으로 명사구를 생성하므로 단어의 연관성을 이용하여 문서의 특징을 추출하는 기존 방법에 대한 문제점을 해결한다. 제안한 방법의 성능을 평가하기 위해 Naive Bayes 분류자를 이용한 문서 분류에 적용하여 정보이득, 역문헌빈도의 방법과 비교하며, 또한 색인어의 연관성과 확률 모델을 기반으로 단어의 연관성을 이용하여 문서 분류를 하는 기존의 방법과 각각 비교한다.

• 대한치과교정학회지
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• 제48권3호
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• pp.172-181
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• 2018

Objective: This study was performed to investigate buccal facial depth (BFD) changes after extraction and nonextraction orthodontic treatments in post-adolescent and adult female patients, and to explore possible influencing factors. Methods: Twelve and nine female patients were enrolled in the extraction and nonextraction groups, respectively. Changes in BFD in the defined buccal region and six transverse and two coronal measuring planes were measured after registering pretreatment and posttreatment three-dimensional facial scans. Changes in posterior dentoalveolar arch widths were also measured. Treatment duration, changes in body mass index (BMI), and cephalometric variables were compared between the groups. Results: BFD in the buccal region decreased by approximately 1.45 mm in the extraction group, but no significant change was observed in the nonextraction group. In the extraction group, the decrease in BFD was identical between the two coronal measuring planes, whereas this differed among the six transverse measuring planes. Posterior dentoalveolar arch widths decreased in the extraction group, whereas these increased at the second premolar level in the nonextraction group. The treatment duration of the extraction group was twice that of the nonextraction group. No differences were found in BMI and Frankfort horizontal-mandibular plane angle changes between the groups. BFD changes in the buccal region moderately correlated with treatment duration and dental arch width change. Conclusions: BFD decreased in adult female patients undergoing extraction, and this may be influenced by the long treatment duration and constriction of dentoalveolar arch width. However, nonextraction treatment did not significantly alter BFD.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제36권2호
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• pp.119-124
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• 2010

Introduction: Surgical extraction of third molar is one of the most frequently performed procedures in oral and maxillofacial surgery unit as the impacted wisdom teeth could cause various complications. Even though, however, extraction of the impacted wisdom teeth is an obligation for the reason of possible complication even for general practitioners, it has been avoided. Various factors concerning surgical extraction of impacted third molar are considered: general condition of patients, relationship with relative anatomies, aspects of impaction, surgeon's skill. Materials and Methods: The consideration and crossing analysis of these factors with 2,463 patients who visit Dankook University dental hospital to extract those impacted third molar. Results: 1. Gender doesn't affect. 2. Medical problems have more complications. 3. There are more complications in high difficulty index (DI) impacted teeth. 4. When inferior alveolar canal overlap mandibular third molar, complication rate is 26.92%. 5. The most common complication was swelling and pain. 6. There is no statistical difference between the incidence of complication and surgeon's experience. Conclusion: In regard to these results, it seems that clinical or radiological examination can predict potential complications of wisdom teeth, and it is helpful to bear in mind the fact.

• 대한치과교정학회지
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• 제52권2호
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• pp.102-111
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• 2022

Objective: To develop and explore the usefulness of an artificial intelligence system for the prediction of the need for dental extractions during orthodontic treatments based on gender, model variables, and cephalometric records. Methods: The gender, model variables, and radiographic records of 214 patients were obtained from an anonymized data bank containing 314 cases treated by two experienced orthodontists. The data were processed using an automated machine learning software (Auto-WEKA) and used to predict the need for extractions. Results: By generating and comparing several prediction models, an accuracy of 93.9% was achieved for determining whether extraction is required or not based on the model and radiographic data. When only model variables were used, an accuracy of 87.4% was attained, whereas a 72.7% accuracy was achieved if only cephalometric information was used. Conclusions: The use of an automated machine learning system allows the generation of orthodontic extraction prediction models. The accuracy of the optimal extraction prediction models increases with the combination of model and cephalometric data for the analytical process.

• 한국연초학회지
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• 제16권1호
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• pp.20-25
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• 1994

The volatile components were extracted from root of Cnidium officinale M. by SDE(Simultaneous steam distillation and extraction) apparatus and analyzed by GC/M.5 and GC retention index matching. The experimental results revealed the presence of over 22 volatile components. Major components were cnidilide (35.1%), neocnidilids (13.4%), ligustilide (23.2%). The essential oils were separated by silica gel column chromatography(Merck 70-230mesh), and 4 fractions among 12 fractions separated had a, good aroma character.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제41권
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• pp.4.1-4.10
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• 2019

Background: The mandibular third molar (M3) is typically the last permanent tooth to erupt because of insufficient space and thick soft tissues covering its surface. Problems such as alveolar bone loss, development of a periodontal pocket, exposure of cementum, gingival recession, and dental caries can be found in the adjacent second molars (M2) following M3 extraction. The specific aims of the study were to assess the amount and rate of bone regeneration on the distal surface of M2 and to evaluate the aspects of bone regeneration in terms of varying degree of impaction. Methods: Four series of panoramic radiographic images were obtained from the selected cases, including images from the first visit, immediately after extraction, 6 weeks, and 6 months after extraction. ImageJ software^® (NIH, USA) was used to measure linear distance from the region of interest to the distal root of the adjacent M2. Radiographic infrabony defect (RID) values were calculated from the measured radiographic bone height and cementoenamel junction with distortion compensation. Repeated measures of analysis of variance and one-way analysis of variance were conducted to analyze the statistical significant difference between RID and time, and a Spearman correlation test was conducted to assess the relationship between Pederson's difficulty index (DI) and RID. Results: A large RID (> 6 mm) can be reduced gradually and consistently over time. More than half of the samples recovered nearly to their normal healthy condition (RID ≤ 3 mm) by the 6-month follow-up. DI affected the first 6 weeks of post-extraction period and only showed a significant positive correlation with respect to the difference between baseline and final RID. Conclusions: Additional treatments on M2 for a minimum of 6 months after an M3 extraction could be recommended. Although DI may affect bone regeneration during the early healing period, further study is required to elucidate any possible factors associated with the healing process. The DI does not cause any long-term adverse effects on bone regeneration after surgical extraction.

• 대한전자공학회논문지
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• 제27권6호
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• pp.929-936
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• 1990

This paper describes the method of the Korean character recognition by means of feature points extraction. Also, the preprocessing neural chip for noise elimination, smoothing, thinning and feature point extraction has been designs. The subpatterns were separated by means of advanced index algorithm using mask, and recognized by means of feature points classification. The separation of the Korean character subpatterns was abtained about 97%, and the recognition of the Korean characters was abtained about 95%. The preprocessing neural chip was simulated on SPICE and layouted by double CMOS 2\ulcorner design rule.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1995년도 추계학술대회 논문집 학회본부
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• pp.395-397
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• 1995

To investigate the effects of solvent extraction on electrical properties of LDPE, charge distribution, electrical conduction, and FT-IR experiments are carried out for three kinds of LDPE which are same for melt index (MI) and density. The effects of short chains for the charge distribution are quite different. For the electrical conduction, the electrical conduction mechanism remains unchanged, as the solvent extraction temperature is increased.