• KIEE International Transaction on Electrical Machinery and Energy Conversion Systems
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• 제12B권1호
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• pp.1-6
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• 2002

The severe problem in improving the positioning precision of a permanent magnet linear synchronous motor (PMLSM) is the large detent farce caused by the permanent magnet arrangement. It is generally an undesired effect that contributes to the torque ripple, vibration and noise of machine. The detent force is arisen from the difference of the position of a permanent magnet end and a tooth position. In this paper, the four methods to reduce detent force were studied and analyzed. The methods are adjusting the width of permanent magnet, varying the shape of armature teeth, relocating the permanent magnet, and adjusting the width of permanent magnet and relocating the permanent magnet at the same time. To analyze the detent farce according to flour methods, a two-dimensional Finite Element Analysis [FEA] was used and we compared with the ratio of reduction of the detent farce according to the flour methods.

• 대한치과보철학회지
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• 제38권2호
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• pp.147-159
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• 2000

The purpose of this study was the evaluation of spectral transmission of the commercial three shade guides and the relationship of hue, value, and chroma according to the transmission rate. The spectral transmittance of three shade guides - Vita Lumin Shade Guide, Vintage and Unibond Shade Guide, and Vitapan 3D-Master Shade Guide - were measured. For direct transmission measurements, each shade tabs were placed at the entrance port of the 1mm diameter intergrating sphere. The intensity of the light source passing through the shade tabs to the right angle was continuously recorded for wavelength from 400 to 700 nm. A transmission spectrum and digital data were obtained for each measurement and they were evaluated using Microcal Origin program. The obtained results of this study were as follows : 1. In Vita Lumin Shade Guide, sum of the transmission rate of the shade tabs at the wavelength 400-700nm was decreased in agreement with the arrangement order at each A, B, C, D group, except D4 shade tab. However, there were no relationships between the transmission rate of the shade tabs and the value-oriented. 2. In Vintage and Unibond Shade Guide, sum of the total transmission rate of the shade tabs was decreased in agreement with the arrangement order at each A, B, C, B group. When all shade tabs arranged in value-oriented, transmission rate was accord with the order, except D4 shade tab. 3. When shade tabs of the Vitapan 3D-Master Shade Guide have the same value and hue, sum of their total transmission rate decreased in accordance with the chroma-oriented. When the shade tabs have the same value and chroma, there were no differences from the order of the transmission rate to the various hue type. However, in the 'R' tabs of reddish hue type, the transmission rate increased at the long wavelength range area. In conclusion, we need the quantitative analyzing instruments in transmission determination. Vitapan 3D-Master Shade Guide covers the tooth color space taking into account the parameters of the systematic value, chroma, hue oriented, and the transmission rate relatively accorded with that sequence.

• 대한심미치과학회지
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• 제32권2호
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• pp.54-68
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• 2023

디지털 방법을 사용한 무치악의 임플란트 치료계획은 surgical guide design으로 구체화된다. Surgical guide를 제작할 때, 우리는 먼저 최종 보철의 형태를 가상공간에 구현한 후 이를 바탕으로 식립 계획을 구체화하게 된다. 그러나 완전무치악 환자는 치아배열의 기준이 없고 악간관계가 정립되어 있지 않아 최종 보철의 형태를 짐작하기 어려워 surgical guide를 만드는 데 어려움이 있다. 이때 기존의 만족스러운 총의치나 부분의치, 잔존치 등이 존재한다면 그 치아배열이 가상적인 최종 보철의 reference가 될 수 있다. 만약 이러한 reference가 부재하거나 만족스럽지 못하다면, 진단용 목적으로 총의치를 제작하되 이를 구내에서 검증하는 과정이 필요하다. 이러한 과정을 통해 surgical guide를 제작할지라도 구내 상황에 따라 implant의 위치가 계획한 것과 다르게 식립될 수 있으며, 만약 guide의 positioning이 잘못된다면 그 오차는 모든 implant의 위치를 변위시킬 수 있으므로 guide 수술이 오히려 재앙으로 다가올 수 있다. 본 기고에서는 치아 배열의 reference가 될 수 있는 자료들을 적절한 시기에 채득하여 이를 디지털 공간에 이전 및 통일된 좌표계로 정렬하는 방법에 대해 논의하고, 또한 이렇게 수립된 식립계획을 현실의 구강에 적은 오차로 이전 및 정렬하는 방법에 대해 소개하여 일관적이고 체계적인 무치악 가이드 디자인의 프로토콜 정립에 대해 의견 개진하려 한다.

• 대한치과보철학회지
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• 제17권1호
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• pp.35-46
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• 1979

A number of experimental studies have been carried out in order to clarify the question as to how temporomandibular joint adapt to the changes of mandibular movement and occlusal equilibration. Recently, the studies on the interrelations between anatomical structure of temporomandibular joint and the state of occlusion have been actively performed in dentistry particularly in prosthodontic field. Author performed extraction of unilateral mandibular molars in 30 mature male rats, and observed histological changes of temporomandibular joint through the light microscope. Following results were obtained. 1. The loss of unilateral teeth gave rise to the changes in the location of condylar head, that is, interior displacement of condylar head in the extraction side and upper displacement in the non-extraction side. 2. Articular disk was compressed by the interior surface of condylar head, resulting in its extension below the condylar neck in the extraction side, and the histological arrangement of the compressed area showed irregular feature. 3. The extension of articular disk below the condylar neck was accompanied with the contraction of muscle fibers which were originated from the articular disk. 4. The cartilage layer of articular fossa to the exterior of the extraction side showed hypertropy. 5. Early in the experiment, the inernal extremity of condylar head of extract ion side showed bone resorption, and cartilage layer of condylar head showed hypertropy. At 12 weeks after experiment, the condylar surface showed flattened, and the cartilage layer of condylar head was replaced by the compact bone. 6. The articular disk showed the formation of pannus in the extraction side as well as in the non-extraction side. 7. The occlusal disturbance due to unilateral missing teeth has brought about the non-inflammatory retrogressive change and osteoarthrotic change late in the experiment.

• 대한치과보철학회지
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• 제33권2호
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• pp.358-394
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• 1995

The author studied the actual conditions on the production of dental prosthesis made in laboratories, and also studied interrelationships between dentists and laboratory technicians in both personal and technical aspects. Two hundred-eighty four technicians, work in dental laboratories presently, were surveyed via mail and direct contact during the period from June 1 to June 30 and August 27 to August 28 in 1994 respectively. The obtained results were as follows : 1. Among the respondents, 90.5% we re working in commercial dental laboratories and their laboratories were mainly located in the Seoul area(40.9%, P<0.05). The numbers of employees in these laboratories were less than 10 persons(70.0%, P<0.01), and 75.9% of these laboratories have been in operation less than 15 years. 2. Most laboratory procedures were accomplished according to established disciplines. However, procedures such as die trimming in fixed restorations and the qualifications of the people designing removable partial dentures were not. Other problem areas were boxing of the working cast, the person determining the posterior palatal seal area, selection and arrangement of artificial teeth, occlusion rim correction and laboratory remounting of the processed denture in complete denture restorations. 3. Only half of the requesting dentists could send work authorizations to the laboratories with their work and even so, its contents were quite lacking. Consequently, there must be some standards in writing work authorization. 4. Technicians most desired clean and accurate impressions in fixed and removable dentures, and enough tooth reduction in porcelain fused to metal restorations. 5. For the establishment of better relationships between dentist and dental technician, the respondents desired the establishment of equal footing first(33.5%), and frequent conversations and muture understanding second(25.9%).

• 식물분류학회지
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• 제32권4호
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• pp.397-416
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• 2002

한국산 제비꽃속 노랑제비꽃절 (Viola section Chamaemelanium) 식물에 대해 광학현미경 및 전자현미경을 사용하여 형태 분류학적 연구를 수행하였다. 지하경과 지상경의 특징, 자방 돌기 그리고 주두의 모양과 돌기 등의 특징에 의해 V. orientalis와 V. brevistipulata가 구별되었다. 나아가 후자는 잎의 특징에 따라 3 변종 즉 var. brevistipulata, var. minor 그리고 var. laciniata 등으로 세분되었다. Viola brevistipulata var. laciniata는 거치 수가 가장 많고, 불규칙한 치상의 복거치를 갖는다. 그러나 다른 두 변종은 규칙적인 파상 또는 치상의 거치를 갖는다. 세 변종간 잎의 크기는 V. brevistipulata var. brevistipulata가 가장 크고 V. brevistipulata var. minor가 가장 작다. 이들 중 V. brevistipulata var. laciniata는 한국 미기록 종이다. 또한 자방과 주두에 발달된 돌기물의 모양 및 배열양상은 본 절내 종을 동정할 때 중요한 표징형질로 확인되었다.

• 한국치위생학회지
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• 제10권5호
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• pp.807-817
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• 2010

Objectives : The purpose of this study was to analyzes the job implementation of dental hygienist at dental hospital(university), dental clinic and general hospital in the city of Gwangju. Methods : The subjects in this study were dental hygienists who worked at dental hospital(university), dental clinic and general hospital in the city of Gwangju. A survey was conducted by post from June 10 to August 10. Out of the collected data, 204 answer sheets were analyzed. Results : 1. 'Medical & Dental history taking', 'Extra & Intra oral examination' and 'Dental hygiene care plane' in dental clinic were significantly higher than dental hospital(university) and general hospital(p<0.001). 'Remove of extrinsic stain' and 'Treatment of hypersensitivity tooth' in dental clinic and general hospital were significantly higher than dental hospital(university)(p<0.001). 'Preventive dental caries treatment' and 'Diet control' were shown the low frequency of job implementation. 2. Almost task elements of dental assistance duty shown that dental hygienists under the 24 years old were significantly higher dental hygienists over the 30 years old(p<0.05) and dental clinic and general hospital were significantly higher than dental hospital(university)(p<0.05) in frequency of job implementation. 3. 'Dental staff supervision', 'Patient management' and 'Dental chart arrangement' shown that dental hygienists over the 30 years old were significantly higher than dental hygienists under the 24 years old in frequency of job implementation(p<0.05). 'Infection control' of dental hygienists over 30 years old was significantly lower than dental hygienists under the 24 years old(p<0.001). Conclusions : The results of this study indicate that a scope of dental hygienists' job need to extend also in order to accomplish a job efficiently, is suggested that the effort is necessary to improve a quality of dental hygienist and to change of recognition of the dentist about dental hygienists' job.

• 구강회복응용과학지
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• 제31권2호
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• pp.143-149
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• 2015

전치부는 심미적인 관점에서 치열 및 연조직과의 조화가 매우 중요하다. 상악 전치부의 심미적인 치료는 술 전 정확한 진단과 치료계획이 필수적인데 술자는 특히 치관부 크기의 적절한 비율과 치은 형태의 대칭에 대해 충분히 고려해야 한다. 만약 치은의 형태가 비심적이고 부자연스러운 경우에는 치은 절제술, 골삭제를 동반한 치관 연장술, 교정적 정출술 등을 시행할 수 있다. 치관의 형태 및 위치가 부적절한 경우에는 술 전 진단 모형 및 왁스 업을 통해 교정 치료나 완전도재관, 라미네이트 베니어 등의 심미적 보철치료를 계획할 수 있다. 본 증례들에서는 치아의 위치 이상과 연,경조직의 부조화를 가진 전치부를 교정 치료 및 치은 성형과 심미적 보철 치료를 시행함으로써 만족할만한 결과를 얻었기에 이를 보고하고자 한다.

• 대한치과보철학회지
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• 제34권3호
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• pp.457-463
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• 1996

An esthetically pleasing result in denture service is dependent upon several consideration. Esthetic considerations for the edentulous patient include tooth size, shape, arrangement, positioning, gingival contour, age, sex, personality differences, and ethnic type. Especially, the form of anterior artificial teeth is an important factor on the esthetics. The selection of artificaial teeth requires understanding and knowledge on physical and biologic factors and has to meet the indivisul esthetics and functional needs of each patient. However, the selection of artificial teeth is based on the large degree of subjective judgement of the dentist, Therefore, this is one of the most unscientific processes. Many attempts have been made to find a guideline for the selection of artificial teeth. Temperamental theory by White and Hall utillized with the physical characteristics such as body size, body form, color of eyes and hair, and disposition. SPA theory by Frush and Fisher utilized with the basis of sex, personalities, and age of the indivisual. There has not been provided for a guideline and study on the selection of artificial teeth for Koreans yet. This study was aimed to evaluate the William's typal matching theory in Koreans. 1. The facial forms of korean adult were ovoid(46.3%), square(36.7%) and tapered(17.0%) form. 2. The anatomic forms of natural maxillary incisors were ovoid(45.3%), tapered(31.3%), square(23.3%) form. 3. The forms of face and natural maxillary incisors were ovoid(21.9%), squared(11%), tapered(6.3%). 4. The natural maxillary incisors were similar in form to the facial form only in 39%. There was no correlation between the form of the face and the form of natural maxillary central inisors in Koreans. 5. Artificaial teeth which was selected according to the typal matching theory did not represent the form of the natural teeth in 61 per cents of the fatal, but it felt that they harmonized with the form of the patient's face and produced good results.

• 대한치과보철학회지
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• 제59권4호
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• pp.508-514
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• 2021

본 증례는 기존 의치를 스캔 후 프린팅한 복제 의치를 폐구인상시 개인트레이로 사용하였고 이에 기공 과정을 줄이고, 진료시간을 단축시킬 수 있었으며, 안모 평가가 용이하고 치아 배열을 비롯한 총의치 제작과정에 있어 기공 과정이 원활하게 이뤄질 수 있었다. 또한 일반적인 개구인상법을 이용한 제작과정에 비해 내원 횟수를 줄일 수 있었으며 기존 의치의 수직고경을 비롯한 여러 정보를 의치 제작 시 활용함으로써 환자의 새 의치 적응도를 높일 수 있었다.