Air abrasion 기술을 이용한 유치 및 영구치의 수복

조현,이광희,김대업,송인경 大韓小兒齒科學會 2002 大韓小兒齒科學會誌 Vol.29 No.2

Air-abrasion 기술은 입자의 운동에너지를 이용하여 비기계적인 방법으로 치아를 처리하거나 치아표면에 존재하는 착색이나 치석을 제거하는 방법으로서, 환자의 불안이나 불편감을 증가시킬 수 있는 압력, 진동이나 열의 발생이 적고 건전한 치질의 보존이 용이하며 특히 소아환자에서 마취의 필요성을 감소시키고 시술부위에서의 타액오염을 가능성을 줄여주고 건조한 시술부위 유지에 용이하고 수복재의 결합력을 증가시켜주는 등의 여러 장점을 지니고 있어, 복합레진을 위한 와동형성, 열구전색을 위한 치아형성, 산 부식 대신 또는 산부식전 치아표면의 처리, 초기 우식증의 진단 등에 이용될 수 있다. 본 증례는 유중절치의 인접면 우식치료, 유구치의 교합면 우식치료, 제1대구치의 우식치료 및 우식 예방을 air abrasion 기술을 사용하여 수복한 바, 환자의 행동조절 및 시술부위의 완전한 건조가 어려운 소아환자에게 있어 임상적으로 유용하다고 여겨지며 양호한 결과를 얻었기에 보고하는 바이다. Air abrasion technology can prepare enamel and dentin for bonding, similar to etching by acidic gels and solutions. Longer treatment can excavate pit and fissures, preparing the tooth for immediate placement of bonded materials. Although not appropriate for every clinical situation, the air abrasive technology minimizes heat, vibration and bone-conducted noise associated with conventional means of caries removal since the cutting is accomplished by air pressure. Also, patients treated with the air-abrasion technology rarely request anesthesia. Air abrasion technology was more effective in treating early carious lesions and stains compared to lesions where caries had already progressed to produce soft dentin and the strong air stream and noise caused by the evacuation system was a major discomfort to pediatric patients, and the experience and skillfulness of clinician should be required for accurate and proper tooth preparation.

흉배혈관의 근피 천공분지에 기초한 유리피판의 임상적 이용

조규성,김대영,안호범,이삼용,조백현 大韓成形外科學會 1999 Archives of Plastic Surgery Vol.26 No.3

The latissimus dorsi muscle or musculocutaneous flap is one of the most useful flaps in reconstructive surgery. This flap has many advantages, such as its reliable anatomy, long pedicle with large caliber vessels, minimal functional deficit of the donor site, and low incidence of donor site complications. However, the bulkiness of the flap has been considered a disadvantage, so various modifications of technique have been devised. The cutaneous portion of the flap can be safely elevated based on the cutaneous perforating branch of the thoracodorsal vessel. From March 1997 to February 1998, 10 patients underwent reconstructive procedures with thoracodorsal perforator-based free flaps. The composition of the flaps varied in accordance with the nature of the defect. The variances in the flaps were as follows; 3 were cutaneous, 6 musculocutaneous, and 1 osteomusculocutaneous including the rib. All flaps survived with good contour. We concluded that this thin and reliable flap was useful for reconstruction of various defects, and that the composition of the flap, such as subcutaneous, muscle and bone, gave it considerable flexibility as needed.

D.C Magnetron sputtering법으로 제조된 GMR 스핀밸브 조성막에서 증착변수들이 증착속도에 미치는 영향

조대현,이찬규,김병수 國立 昌原大學校 産業技術硏究所 1998 産技硏論文集 Vol.12 No.-

In this study, we have investigated the influence of sputtering conditions(Ar pressure, Input power) on deposition rate of Ni81Fe19, Fe, Co, Cu, Cr86A114, Cr93Ga7 thin films produced by the method of DC magnetron sputtering. In all films, we have observed that the deposition rate increased with input power because of increasing sputter yield, and ion current density. we have found that the deposition rate was decreased with the pressure of Ar gas.

正祖의 學問觀을 통해 본 韓國學의 패러다임

조대현 경기대학교 부설 민족사상연구소 2006 민족사상연구 Vol.14 No.-

Al-Mg-Si合金의 時效擧動에 미치는 加工熱處理의 影響

趙顯麒,李基大,朴定國 慶北大學校 1980 論文集 Vol.30 No.-

Effects of Thermo-Mechanical Treatment(TMT) on ageing behaviours in Al-Mg-Si alloy is investigated by means of tensile test, hardness measurements and transmission electron microscopy. The maximum 0.2% proof stress of the TMT materials in final ageing is higher by 10%∼20% than that of the two-step aged materials. The strength of TMT materials also increases more rapidly than that of two-step aged materials. The maximum 0.2% proof stress of the TMT materials with pre-ageing is higher than that of the TMT materials without pre-ageing. The strength of TMT materials increases with rising pre-ageing temperature, and it decreases with rising final-ageing temperature. Consequently, this type of TMT would have some practical significance in improving the mechanical properties of 6061 alloy.

Chiral Cu(Ⅱ)착화합물과 촉매로 유도된 Carbenoid반응에 의한 2-phenylcyclopropane-carboxylic acid의 광화학 이성체의 합성

조남숙,신대현,이종철,나도영 충남대학교 1985 忠南科學硏究誌 Vol.12 No.2

(-)-(IR, 2R)-trans-menthyl-2-phenylcyclopropanecarboxylate has been synthesized with aid of chiral Cu(Ⅱ) complex catalyst by the addition reaction of menthyldiazoacetate to the styrene. The yield was 80%, the purity of trans-compound over 90% and optical purity 75%. These results show the possibility of synthesis of (-)-(IR, 2R)-trans-2-phenylcyclopropane-carboxylic acid with high purities of optical activity and geometric specificity.

低濃度 Al-Si系合金에 있어서의 Si 析出物의 粗大化 現象

趙顯麒,李基大,崔德淳 慶北大學校 1981 論文集 Vol.31 No.-

The coarsening behaviours of Si precipitates in dilute Al-Si alloys havs been investigated by means of scanning electron microscopy and also determined the number density of Si precipitates and activation energy for the growth of precipitates. The mean radius of Si precipitates in dilute Al-Si alloys was proportional to (time)^(1/3) and this results agree with Lifshitz-Wagner theory for the diffusion controlled mechanism. The number density of Si precipitates was decreased monotonously with increasing of ageing time. Activation energies for the coarsening of Si precipitates in Al-0.8wt% Si alloy and Al-1.2wt%Si alloy were 33.44 Kcal/mol and 32.9 Kcal/mol respectively, which agreed with that of inter-diffusion.

AE 신호의 주파수분석에 의한 Chatter진동의 감시

조대현,이상태,원종식,정윤교 韓國工作機械學會 2000 한국생산제조학회지 Vol.9 No.5

A machine tool generally has some serious stability problems in the form of tool chatter during the cutting process. Chat-ter vibration deteriorates the surface finish, reduce tool and machine life, accelerates machine tool system component wear, and may lead to an unacceptable noise sound in the working environment. In this study, the behavior of spectral density of AE signal and principal cutting force signal in order to monitor the chatter vibration in the cutting process has been investi-gated. From the results, the reliability of proposed monitoring method has been confirmed.

이족보행로봇용 통합개발환경의 구현 및 이동경로계획 알고리즘의 설계

조규현,김대원 明知大學校 産業技術硏究所 1995 産業技術硏究所論文集 Vol.14 No.-

In this paper, an integrated developing environment(IDE) for a biped robot is presented, through which a new path planning algorithm is designed. The IDE is composed of four modules, each of which is designed by using the object-oriented programming techniques. Four modules have the capability of gait control, path planning, mission-level language interpretation, and monitoring respectively. Also, each module exchanges its information each other through database. The new path planting a1gorithm is composed of an environment analysis algorithm and a path search algorithm, and is used in the IDE. In this paper, an extended visibility graph algorithm is proposed as the environment analysis algorithm and the A algorithm is used as the path search algorithm for the path planning of biped robots. Since the path planning a1gorithm is designed by using the object-oriented techniques and is also implemented within the IDE, it has a good adaptability to the changes of algorithm and construction, and also has a high reusability of the designed capabilities.

하악골에 발생된 Low grade 골육종:증례보고

조현이,정종철,김호성,최재욱,성대경,서지훈,김성범,이계혁 大韓顎顔面成形再建外科學會 2000 Maxillofacial Plastic Reconstructive Surgery Vol.22 No.1

Osteosarcoma is a primary malignant tumor arising most often in the long bone, but rare in jaw bone. Especially osteogenic sarcoma of the mandible is a rare tumor, comprising less than 0.5% of all head and neck tumors. Osteosarcoma occurs cheifly in young persons, and presenting very survival rates. Histopathologically this tumor can be classified three types, osteoblastic, fibroblastic, chondroblastic and classified from low grade to high grade by anaplasia or mitosis of the tumor cells. Sometimes, the exact diagnosis of osteosarcoma is difficult especially in low grade osteosarcoma, even if clinical or radiographical findings suggest to osteosarcoma. So suspcious to malignant bone tumor in clinical or radiological findings, biopsy should be taked from deep portion and multiple area, and sharing the patient history and radiographs with pathologist will assist in the development of the diagnosis. We report a case of low grade osteosarcoma on the mandible initially difficulty in accurate diagnosis. The patient visited our hospital for routine dental treatment but radiographic findings displayed ill-defined radiolucency with osteoid formation on the mandible. Final diagnosis was difficulty in initial biopsy but subsequent biopsy taked from deep portion presented infiltrative growth and mitosis of the tumor cell in some area with small osteoid bone formation, so we could reach final diagnosis as low grade sarcoma. We treated this patient with bloc resection of the mandible and immediate reconstruction with iliac corticocancellous block.