• 구강회복응용과학지
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• 제25권4호
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• pp.417-429
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• 2009

골유착성 임플란트가 소개된 이후로 부분 및 무치악 부위에서 사용되어 높은 성공률과 함께 예지성 있는 결과를 보여주는 치료방법으로 인정받고 있다. 그러나 국내에서 개발된 임플란트에 대해서는 임상적이고 객관적인 연구 자료가 불충분하다. 본 연구에서는 31명의 환자에게서 임플란트 경부에 미세나사를 지닌 임플란트 식립 후 평균 21개월의 기간 동안 임플란트의 생존율에 관한 조사를 시행하였고 부하가 가해지는 시점을 기준으로 12개월 간 변연골의 변화를 파노라마사진을 이용하여 측정 관찰하여 다음의 결과를 도출하였다. 총 96개의 임플란트에서 3개의 임플란트가 실패하여 96.9%의 생존율을 보였다. 50대 환자에서 85.7%로 가장 작은 생존율을 보였으며 성별 및 연령에 따른 생존율 및 변연골 흡수량에 대한 통계적 유의성은 존재하지 않았다. 상악에서는 95.7% 하악에서는 100%의 생존율을 보였다. 골이식 여부, 보철물의 종류, 매식체의 길이 및 직경에 따른 생존율의 차이는 통계적으로 유의한 차이를 보이지 않았다. 기능 부하 후 임플란트 변연골 흡수량은 단일 금관 보철물이 연결 고정 보철물에 비해 증가된 양상을 보였으나 임플란트의 직경, 길이, 골이식의 유무, 식립위치에 의해서는 통계적으로 유의한 차이를 보이지 않았다. 이 연구를 통해 경부에 미세나사를 지닌 임플란트 식립 후에 임플란트 변연골 흡수량은 비교적 적게 일어났으며 또한 안정적으로 유지되는 것이 관찰될 수 있었고 이에 따른 장기적인 추적관찰이 필요할 것으로 사료된다.

• 대한치과보철학회지
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• 제30권4호
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• pp.611-621
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• 1992

저자는 두개의 브로네마트 임플란트를 지대치로 하는 가공의치를 제작할 때 임플란트의 길이에 따른 임플란트 주위 조직의 응력분산양상을 평가하기 위하여 임플란트의 길이가 각각 10mm, 7mm, 5mm인 여섯가지의 실험모형을 제작하고 가공의치 중아부에 64kg의 수직하중을 가하여 2차원적 광탄성응력분석 실험을 행하여 비교 분석 해본 바, 다음과 같은 결론을 얻었다. 1. 여섯가지 실험모형 중 응력분산 양상은 실험모형 I (10mm, 10mm)일 경우가 가장 좋았다. 2. 근심과 원심에 같은 길이의 임플란트를 매식하였을 경우, 응력은 대체로 임플란트 표면적의 감소에 비례하여 증가하였다. 3. 근심과 원심에 다른 길이의 임플란트를 매식하였을 경우, 짧은 쪽 임플란트의 경부에 응력이 집중되었다.

• 대한물리치료과학회지
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• 제11권2호
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• pp.18-26
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• 2004

The purpose of this study was to compare difference of the static and dynamic balance in normal subject and LBP subject and recognizes about postural sway. The subjects of this study included 30 normal subjects and 30 LBP subjects. By using Active balance system, the static balance was measured by unit path length, circumference area, weight bearing, stabilometry length, while the dynamic balance was measured by step evaluation. Statistically analyzed using independent t-test to search static balance and dynamic balance difference in two groups. Postural sway appeared greatly in patient group than normal group in analysis result of static balance and postural sway was big in patient group of when closed eye and normal group and patient group did show statistical significance in unit path length, circumference area. Weight support of normal group was shared equally in weight bearing rate, but weight support of patient group stewed less to pain side. Anterior step time and Task achieve time of dynamic balance were spent more in patient group than normal group. Desire to be used to useful information to lay treatment policy about set-up and action of when quantification result of valued postural balance treats low back pain patient by objective tool, in the fixture, more researches in postural estimation desire that is enforced abuzz.

• 대한치과보철학회지
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• 제48권3호
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• pp.181-188
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• 2010

연구 목적: 내부연결형 임플란트 고정체에 연결 방식이 다른 4종류의 지대주를 연결하여 교합력을 가하였을 때 각 구조에 발생하는 응력의 차이를 비교하고, 이들 연결방식이 임플란트 주위조직의 응력분포에 미치는 영향을 3차원 유한요소법을 통하여 알아보고, 지대주의 선택 기준을 마련하고자 하였다. 연구 재료 및 방법: 고정체로는 직경 4 mm, 길이 11.5 mm의 SS-$III^{(R)}$ (Osstem, Korea)를 사용하였으며, 사용된 지대주는 각각, 모델 1에서 Solid abutment, 모델 2에서 Com-Octa abutment, 모델 3에서 ComOcta Gold abutment, 모델 4에서 Octa abutment를 사용하였고, 네 가지 하중조건으로 치관중심와 (central fossa)에 fixture 장축에 평행하게 점하중으로100N의 수직하중, 협측교두에 대하여 fixture 장축에 평행하게 점하중으로 100N 수직하중, 치관중심와에서 설측으로 100N의 $30^{\circ}$ 경사하중, 협측교두 (buccal cusp)에 치아의 바깥쪽에서 내측으로 100N의 $30^{\circ}$ 경사하중을 주었고 3G.Author (Plasso Tech, USA)를 이용하여 분석하였다. 결과: 1. 골조직에서는 모든 모델에서 하중조건에 관계없이 가장 큰 응력이 고정체 상부에 집중되었고, 고정체 하부에서는 근단 부위에서 응력 집중을 보였으며, 그 외의 부위에서는 큰 응력 집중은 보이지 않았다. 2. 고정체에서의 응력은 모든 모델에서 하중조건에 관계없이 neck 부위에서 최대의 양상을 보였다. 3. 응력은 골에서보다 임플란트 내부에서 훨씬 높았다. 4. 중심와에 수직하중인 하중조건 1에서 가장 낮은 응력이 관찰되었으며, 이 때의 응력집중 현상도 가장 적게 나타났다. 서로 다른 지대주에서 응력분포 양상을 살펴본 결과, 같은 고정체를 사용한 경우에 지대주의 연결 형태에 따른 골조직에서의 응력 분포의 차이는 없었다.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2005년도 추계종합학술대회
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• pp.785-788
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• 2005

In this study, micro-scale, high-performance, solenoid-type RF chip inductors were investigated. The size of the RF chip inductors fabricated in this work was $1.0{\times}0.5{\times}0.5mm^3$ The material and shape of the core were 96% $Al_2O_3$ and I-type. The material and number of turn of coil were copper (Cu) and 6. The diameter ($40{\mu}m$) of coil and length (0.35mm) of solenoid were determined by a Maxwell three-dimensional field simulator to maximize the performance of the inductors. High frequency characteristics of the inductance (L) and quality-factor (Q) of developed inductors were measured using an RF Impedance/Material Analyzer (HP4291B with HP16193A test fixture). The inductors developed have inductances of 10.8nH and quality factors of 25.2 at 250MHz, and show results comparable to those measured for the inductors prepared by CoilCraftTm that is one of the best chip inductor company in the world. The simulated data predicted the high-frequency data of the Land Q of the inductors developed well.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제27권1호
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• pp.39-47
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• 2005

The purpose of this study is to review the prognosis of the TG Osseotite implant(3i Co, USA) placed in partial edentulous area of oral cavity and to suspect the possible causes leading to failure. 124 TG Osseotite implants that had been inserted between 2000 - 2002 were followed up for 2 years(avg : 9.5 months) in function. Medical records, and radiographs were evaluated and analyzed by the over all success rate, gender and age factor, general disease, implant fixture length and diameter, implant site, bone density, and various surgical methods. Chi square test was used statistically. Of the 124 TG Osseotite implants, 9 implants(7.3%) were removed in early phase and 3 implants(2.4%) were in late phase. The cumulative survival rate was 90.2%. The failure of the TG Osseotite implant was closely related with the use of bone graft techniques such as sinus elevation or immediate implantation and not with the age, sex, general disease, implant site, bone density of implanted site. The failure of the TG Osseotite implant was well developed when it was the wide type of implant and it was inserted for single tooth replacement. The developement of peri-implantitis was the most important factor in the failure of the TG Osseotite implant.

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제52권11호
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• pp.501-507
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• 2003

In this study, microscale, high-performance, solenoid-type RF chip inductors were investigated. The size of the RF chip inductors fabricated in this work was 1.0${\times}$0.5${\times}$0.5㎣. 96% $Al_2$ $O_3$and I-type were used as the material and shape of the core, respectively. The copper (Cu) wire with 6 turns was employed as the coils. The diameter (40${\mu}{\textrm}{m}$) and position (middle) of the coil and the length (0.35mm) of solenoid were determined by a high-frequency structure simulator (HFSS) to maximize the performance of the inductors. High frequency characteristics of the inductance (L) and quality-factor (Q) of developed inductors were measured using an RF Impedance/Material Analyzer (HP4291B with HP16193A test fixture). The inductors developed have inductances of 10.8nH and quality factors of 25.2 to 50 over the frequency ranges of 250MHz to l GHz, and show results comparable to those measured for the inductors prepared by CoilCraf $t^{Tm}$ . The simulated data predicted the high-frequency data of the L and Q of the inductors developed well.l.

• 제어로봇시스템학회논문지
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• 제20권12호
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• pp.1267-1271
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• 2014

There have been many autonomous robot calibration methods which form closed loop structures through the various attached sensors and mechanical fixtures. Single point calibration among them has been used for on-site calibration due to its convenience of implementation. The robot can reach a single point with infinitely many configurations so that single point calibration algorithm can be set up and easily implemented relative to the other methods. However, it is not still easy to drive the robots' sharp edge to its corresponding edge of the fixture. This is error-prone process. In this paper, we propose a 3 dimensional small displacement measuring sensor and a robot calibration algorithm based on this sensor. This method relieves the difficulty of matching two edges in the single point calibration and improves the resulting robot accuracy. Simulated study is carried out on a Hyundai HA06 robot to show the effectiveness of the proposed method over the single point calibration. And also, the resulting robot accuracy is compared with that from 3D laser tracker based calibration to show the dependency of robot accuracy on range of the workspace where the measurement data are collected.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제36권5호
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• pp.224-229
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• 2014

The maxillary posterior area is the most challenging site for the dental implant. Although the sinus graft is a predictable and successful technique for rehabilitation of atrophic and pneumatized posterior maxilla, when there is severe destruction of alveolar bone, a very long crown length remains challenging after successful dental implants installation with sinus graft. We performed vertical augmentation of the maxillary posterior alveolar ridge using the allogenic block bone graft with a simultaneous sinus graft using allogenic and heterogenic bone chips. After about six months, we installed the dental implant. After this procedure, we achieved a more favorable crown-implant fixture ratio and better results clinically and biomechanically. This is a preliminary report of vertical augmentation of maxillary posterior alveolar ridge using allogenic block bone graft and simultaneous maxillary sinus graft. Further research requires longer observation and more patients.

• 대한용접접합학회:학술대회논문집
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• 대한용접접합학회 2002년도 Proceedings of the International Welding/Joining Conference-Korea
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• pp.181-186
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• 2002

Laser welding application for car body manufacturing has many advantages in the stiffness and the lightness of vehicle, the productivity of assembly line, and the degree of freedom in design. This presentation will express the innovation of car body manufacturing including parameter optimization, process modeling, and system integration. In this application the investment for systems was cut down dramatically by real time switching over the laser path between two welding stations. Points of technical discussion are as follows: optimization of parameters such as laser power, robot speed and trajectory, compact and useful design of jig & fixture to assure welding quality for 3 sheet-layer zinc-coated steel, system integration between 4kW Nd:YAG laser device and the other systems, on-line real time welding quality monitoring system, perfect safety standards for high power laser, minimization of consumption costs such as arc lamp, protective glass for optic, etc. Laser welding has found a place on Hyundai's production plant in conjunction with the startup of mass production of new sports car, and this production system is the result of a collaboration of its engineers. Outer side sheets are joined to inner side sheets by 122 stitch welds totally. And the length is about 2.4meter.