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.

正祖의 學問觀을 통해 본 韓國學의 패러다임

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

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.

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.

Ruled Surface로 형성된 임펠러 블레이드 전용 CAD/CAM 시스템 개발 Ⅱ : 5-축 가공에 관한 연구 A Study on the 5-Axis Machining

조현덕,정대일,윤문철,최두선,신보성,이응숙,董玉革 한국공작기계학회 2002 한국생산제조학회지 Vol.11 No.3

This study is continuous with the study 1 (A Study on the Modeling) and the sample impeller of this study is defined by the modeling process of the exclusive CAD/CAM system developed in the study I. And, this study describes a method for the 5-axis machining of impeller blades formed by ruled surface. Therefore, the exclusive CAD/CAM system is the software for modeling and machining of impeller blades. By using the machining method suggested in this study, we could manufacture impeller blades on 5-axis CNC machining center and the machined impeller was very agreeable to the designed impeller. Thus, theories proposed in this study can be very useful for the 5-axis machining of impeller blades.

Ruled Surface로 형성된 임펠러 블레이드 전용 CAD/CAM 시스템 개발 Ⅰ : 모델링에 관한 연구 A Study on the Modeling

조현덕,정대일,윤문철,최두선,신보성,이응숙,董玉革 한국공작기계학회 2001 한국생산제조학회지 Vol.10 No.6

We have developed the exclusive CAD/CAM system for the machining of impeller blades. This study is about the modeling method for the effective machining of impeller blades formed by ruled surface. As the impeller is consisted of boss part and blade part, the boss is modeled by rotational surface of hub curve on z-axis and the blade is described by ruled-surfaces between hub curve and shroud curve. This modeling process can be carried out on the software developed in this study. And, the developed software can describe the impeller as a solid model through interface with Solid-Works software. The developed software containing the interface method proposed in this study was very effective for impeller modeling.

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.

Al-Zn合金의 時效析出에 미치는 直流電流의 영향

趙顯麒,李基大,金敎漢 慶北大學校 1980 論文集 Vol.29 No.-

The effect of direct current on precipitation in Al-Zn alloy is investigated by measurement of electrical resistance as a function of current density up to about 2400A/㎠ at a constant quenching temperature. The changing rate of electrical resistance is observed at 300°, 350°, 400° and 450℃, from which retarding coefficient is attained. It can be concluded that there exists some effects of direct electric current to retard the ageing-precipitation and this retarding effect is related to the sinking of quenched-excess vacancy into grain boundaries by electromigration. In the case of quenching temperature above 350℃, the retarding coefficient of direct electric current is less than that can be expected.

Al-Zn-Mg合金의 加工熱處理에 미치는 遷移元素의 影響

趙顯驥,李基大,金熙都 慶北大學校 1982 論文集 Vol.33 No.-

An investigation for influence of a small additions of transition metals (Mn, Zr, Cr) on the thermomechanical treatment (TMT) in Al-Zn-Mg alloys has been carried out by means of the measurements of tensile strength and micro-vickers hardness. The results obtained from this experiment are summarized as follows; 1) Hardness and strength of Al-Zn-Mg alloys are increased remarkable by a small additions of transition metals (Mn, Zr, Cr) at as-quenched state. 2) Influence of a small additions of transition metals like Mn, Zr and Cr added to Al-Zn-Mg alloys on ageing phenomena was retarding the ageing character. 3) The mechanical properties (hardness and strength) of Al-Zn-Mg alloys which were processed by TMT are increased when the deformation rate is lower than 30%, on the other hand those of Al-Zn-Mg alloys added transition metals were decreased with increasing deformation rate.

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.