• The korean journal of orthodontics
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• v.29 no.3 s.74
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• pp.361-374
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• 1999

Intraoral filled type of orthodontic appliance can cause reversible or irreversible damages such as gingivitis, periodontitis, enamel decalcification, dental caries, root resorption, and pulpal changes. Such adverse effects are brought by increase in dental plaque as well as oral flora. Such an increase causes gingival inflammation and enamel decalcification. The purpose of this study is to get klowledge on initial changes in dental plaque, gingivitis, and enamel decalcification after bonding fixed orthodontic appliances according to time flow, gender, and sides(right/left) of premolar region. For control group, 48 students of dental college, Yonsei university(26 males, 22 females) were chosen; for experimental group, 73 orthodontic patients(36 males, 37 females) who will be treated with fixed appliances were chosen. All the subjects had no systemic disease, juvenile periodontitis and all the females had passed their ,menarche. Tooth brushing instruction was given to all the subjects prior to the experiment. For control group, plaque index, gingival index, and decalcification index were measured twice at 3 weeks interval ; for experimental group, the same was done prior to, 3, 6, 9 weeks after bonding fixed appliances. The following results were obtained: 1. In plaque index 3 weeks after placement of appliances, and it showed gradual increase afterwards. 2. In gingival index3 weeks after placement of appliances, and afterwards it showed increase at a faster rate than plaque index. 3. Enamel decalcification began to show between 3 and 6 weeks after bonding fixed appliances. Decalcification index began to increase 6 weeks after appliance placement, but there was no statistical significance. 4. When the comparison was made between two sides of premolar region, the right side showed greater index in plaque and gingival index of experimental group.

• Proceedings of the Korean Society of Computer Information Conference
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• 2016.07a
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• pp.337-338
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• 2016

본 논문에서는 TJ 커플러 제작용 멀티 절삭기에 대해 제안하였다. TJ 커플러 제작용 멀티 절삭기는 동시에 2개 이상의 커플러를 절삭할 수 있는 기능을 수행하면서 안전성을 확보할 수 있는 절삭기이다. 커플러의 종류에 따른 절삭이 이루어 질 수 있도록 절단석과 연마석을 고정하는 장치를 개발하였다. 또한 작업 환경에 대한 안전성을 확보하기위해 비상정지와 기능상의 정지 기능을 추가하여 안전하면서 빠르게 절삭 작업 수행이 가능하도록 하였다. 절단된 커플러에 대해 반자동으로 수거가 되며 쉽게 새로운 커플러를 고정시킬 수 있도록 고정 및 수거 장치를 포함하여 현재의 절삭기보다 빠르고 효과적인 작업이 가능할 것이다.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2003.06a
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• pp.705-708
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• 2003

To observe a hydrated biological specimen, an environmental chamber was necessary to keep the specimen in a wet state under vacuum surroundings. The specimen holder is as follows designed consequently. The specimen holder consisted of two Si wafers, the centers of which were Si$_3$N$_4$(100nm thickness) windows of a 0.3mm square. The windows were made by a photo-lithographic method. The transmission of a window at 400eV is about 70%. A hydrated biological specimen was put between the two windows. When the chamber was closed, two wafers were contact at the metal mesh by the pressure of O-rings, and the specimen holder moved by the three micrometers.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1995.04b
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• pp.251-255
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• 1995

정밀위치결정 기구는 정밀가공기, 계측기기, 반도체 제조장치등의 각종산업기기에 있어 중요 장치로 많이 이용되고 있다. 반도체 회로의 고정밀화, 고집적화, 가공기의 고정도화와 함께 위치결정기구의 기술은 매년 엄격해지고 있다. 현재는 0.1 -0.01 .$\mu$ m의 정도가 요구되고 있어 이에 대응할 수 있는 고정밀 미동제어 위치결정 제어에 대한 연구가 활발히 진행되고 있다. 또한 고정도와 함께 대스트로크(Stroke)를 가지며, 동시에 고속동작의 실현이필요하다. 따라서 이런 여러 성능을 만족시키는 것은 고부가가치 산업에 있어 매우 중요한 조건 중의 하나이다.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2013.11a
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• pp.143-144
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• 2013

Unit module system produce units in the factory and assemble in the field. This unit module system has advantages of shortening the process of construction. However, it is still in the early research related to setting the unit module which is transported by truck to the field. Therefore, when transporting the unit module, this goal of study develops fixed devices. And suggesting device were performed that simulations analyzed maximum stress and assessed the safety.

• Proceedings of the KIEE Conference
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• 2003.07b
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• pp.1259-1261
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• 2003

고정밀 와이어컷 방전가공기는 높은 정밀도를 갖는 금형제작에 사용되고 있는 공작기계로서 최근 나노단위의 가공기술이 요구되는 산업추세에 발맞추어 고속, 고정밀 가공특성을 갖추도록 전반적인 성능개선이 이루어지고 있다. 본 논문에서는 기존 Thyristor를 이용한 위상제어 방식보다 우수한 특성을 갖는 스위칭모드 방식의 10kW급 직류 전원장치의 개발에 대해 기술하고있다.

• Proceedings of the KIEE Conference
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• 2011.07a
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• pp.1201-1203
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• 2011

이 논문은 가속기에 사용되는 전자석용 전원장치 개발에 대해서 기술하였다. 이 전원장치는 DSP TMS320F2808과 ADCs, FPGA를 이용한 디지털 신호처리 기술을 적용하여 5ppm 이하의 출력 전류 안정도를 가진다. 여기서는 전원장치의 입력 및 출력 필터, 비례적분 보상기 등에 대한 설계, 전원장치 모의실험 결과 및 제작 후 출력 전류의 안정도, 시스템의 주파수 특성 등 여러 성능의 측정 결과에 대하여 기술하였다.

• Journal of the Korean Society for Precision Engineering
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• v.13 no.5
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• pp.15-29
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• 1996

공작기계의 성능향상의 기본과제인 고정도화, 고능률화, 그리고 자동화를 더욱 강력히 추진하기 위해서는 FMS의 핵심이 되는 Machining Center(MC)에서, 공작물의 자동교환장치, 공구관리장치, 자동계측장치, 절삭상태 감시장치를 보유하고, System의 자동화를 신뢰성있게 하기 위한 자동진단 장치를 포함하는 종합적인 System이 절실히 요구되고 있다. 이와같은 System으로서의 높은 정도 안정성과 신뢰성을 전제로 한다.

• Journal of the Korean Orthopaedic Association
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• v.54 no.5
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• pp.457-462
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• 2019

The treatment of a brachymetacarpia using conventional distraction osteogenesis requires holding an external fixator following distraction for stability, which causes prolonged discomfort that adversely affects the patient's daily activities. This paper reports a case of a 20-year-old male of brachymetacarpia treated with distraction osteogenesis combined with a plate reducing the period of an external fixator, allowing rapid return to the daily activities, and presenting good clinical results.

• 한국HCI학회:학술대회논문집
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• 2008.02a
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• pp.573-578
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• 2008

Recently, we should control various devices such as TV, audio, DVD player, video player, and set-top box simultaneously to manipulate home theater system. To execute the function the user want in this situation, user should know functions and positions of the buttons in several remote controllers. Normally, people feel difficult due to these realistic problems. Besides, the number of the devices that we can control shall increase, and people will confuse more if the ubiquitous home environment is realized. Therefore, user adaptive interface that provides the summarized functions is required. Moreover there can be a lot of mobile and stationary controller devices in ubiquitous computing environment, so user interface should be adaptive in selecting the functions that user wants and in adjusting the features of UI to fit in specific controller. To implement the user and controller adaptive interface, we modeled the ubiquitous home environment and used modeled context and device information. We have used Bayesian network to get the degree of necessity in each situation. Behavior selection network uses predicted user situation and the degree of necessity, and it selects necessary functions in current situation. Selected functions are used to construct adaptive interface for each controller using presentation template. For experiments, we have implemented ubiquitous home environment and generated controller usage log in this environment. We have confirmed the BN predicted user requirements effectively as evaluating the inferred results of controller necessity based on generated scenario. Finally, comparing the adaptive home UI with the fixed one to 14 subjects, we confirmed that the generated adaptive UI was more useful for general tasks than fixed UI.