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.

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.

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.

Nd:YAG 레이저 조사와 불화물 도포가 탈회법랑질의 재광화에 미치는 영향

조현,이광희,김대업 大韓小兒齒科學會 2004 大韓小兒齒科學會誌 Vol.31 No.3

Normal pulsed Nd:YAG 레이저 조사와 불소화합물이 산성음료수에 의해 탈회된 법랑질의 표면 미세경도에 미치는 재광화 효과를 평가하고자 한다. 법랑질 시편을 제작하여 50ml 플라스틱 시험관 5개에 코카콜라를 채운 후 30개의 소구치를 6개씩 나누어 넣고 탈회시켰다. 법랑질 표면에 6W 출혁하의 50mJ 에너지 밀도, 20Hz의 pulse rate로 레이저를 조사하였다. 레이저가 조사된 법랑질 표면에 각 군별로 여러 형태의 불소화합물을 처리한 후 탈회 전, 후의 미세경도 및 Diagnodent를 측정하였다. 동일한 방법으로 탈회된 법랑질에 레이저를 조사했을 때와 레이저가 조사된 법랑질 표면에 불소화합물을 처치한 후에 미세 경도 및 Diagnodent를 측정하였다. 법랑질 표면을 산성 음료에 탈회 후, 레이저 조사 후, 불소화합물 처치 후의 각각의 시편에 대하여, 주사전자현미경으로 1500배 확대하여 관찰하였다. 1. 산성 탈회된 법랑질 표면의 미세경도(VHN)가 레이저를 조사한 수와 불소 도포 후에 증가하였으나, 레이저 조사 후의 경도와 불소 도포 후의 경도간의 차이는 유의하지 않았다. 2. 초기 경도, 탈회 후 경도, 레이저 조사 후 경도, 불소 도포 후 경도에서 불소군 간의 차이는 모두 유의하지 않았고, 불소 용액 군과 불소 젤 군에서는 레이저 조사 후의 경도와 불소 도포 후의 경도 간에 유의한 차이가 없었으나, 불소 바니쉬군에서는 유의한 차이가 있었다. 3. Diagnodent 측정치의 변화에서 초기 점수, 탈회 후 점수, 레이저 조사 후의 점수와 불소 도포 후의 점수 간에는 유의한 차이가 있었고, 레이저 조사 후 점수와 불소 도포 후의 점수가 불소 도포 군 사이에서는 유의한 차이가 없었다. 4. 산성 음료수에 탈회된 법랑질 표면에의 Nd:YAG 레이저 조사는 재광화에 효과적이며, 불소화합물의 처치는 레이저의 효과를 증가시키는 부가적인 효과를 갖는다. 5. 주사 전자 현미경상에서 Nd:YAG 레이저가 조사된 법랑질 표면은 전체 표면이 법랑소주가 녹아내려 융합된 매끈한 바닥에 균열이 생기고 분화구가 퍼져 있는 양상을 보였으며, 불소 도포 후에는 균열과 분화구 형태는 뚜렷하지 않으며 탈회된 후의 표면에 가까운 양상을 보였다. The purpose of this in vitro study was to investigate the effects of Nd:YAG laser irradiation and fluorides on acid demineralized enamel. The materials were 30 freshly extracted permanent premolars with intact smooth enamel surfaces. They were demineralized with Coca-cola at 37℃ for 12 hours and then irradiated by Nd:YAG laser with 6W power, 50mJ/㎠ energy density, and 20Hz pulse repetition. After laser irradiation, teeth were treated by three kinds of fluorides; (1) 0.05% NaF fluoride solution (2) 1.23% APF gel and (3) 0.1%F fluoride varnish, microhardness(VHN) and Diagnodent scores were measured and the surfaces of each treated specimens were also observed with SEM under 1500 magnification. The results were as follows: 1. In the change of microhardness(VHN), it decreased to 34.68% from the initial micrhardness, increased to 78.37% after laser irradiation and increased to 82.62% after fluoride treatment, there were significant differences except when it was irradiated and treated with fluoride(P<0.05). 2. In the change of Diagnodent scores, it was decreased to 28.08% from the initial scores after demineralization, and then increased to 59.81% after laser irradiation, and increased to 82.17% after fluoride treatment. Scores were different significantly between the scores of initial, demineralization, laser irradiation and fluoride treatment (P<0.05). All the scores were not different significantly between fluoride types. 3. SEM observation showed that the lased enamel surfaces after demineralization were thermally degenerated and showed molten lava-like appearance and crater with cracks and many microholes.

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.

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.

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.

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.

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.

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.