광조사 방식이 복합레진의 중합과 누출에 미치는 영향

박종진,박정원,박성호,박주명,권태경,김성교 大韓齒科保存學會 2002 Restorative Dentistry & Endodontics Vol.27 No.2

The aim of this study was to investigate the effect of light irradiation modes on polymerization shrinkage, degree of cure and microleakage of a composite resin. VIP^™ (Bisco Dental Products, Schaumburg, IL, USA) and Optilux 501^™(demetron/ Kerr, Danbury, CT, USA) were used for curing Filtek^™ Z-250(3M Dental Products, St. Paul., MN, USA) composite resin using following irradiation modes: VIP^™ (Bisco) 200mW/cm^2 (V2), 400mW/cm^2 (V4), 600mW/cm^2 (V6), Pulse-delay (200 mW/cm^2 3 seconds, 5 minutes wait, 600mW/cm^2 30seconds, VPD) and Optilux 501^™ (Demetron/Kerr) C-mode (OC), R-mode (OR). Linear polymerization shrinkage of the composite specimens were measured using Linometer (R&B, Daejeon, Korea) for 90 seconds for V2, V4, V6, OC, OR groups and for up to 363 seconds for VPD group (n=10, each). Degree of conversion was measured using FTIR spectrometer (IFS 120 HR, Bruker Karlsruhe, Germany) at the bottom surface of 2 mm thick composite specimens. V2, V4, V6, OC groups were measured separately at five irradiation times (5, 10, 20, 40, 60 seconds) and Or, VPD groups were measured in the above mentioned irradiation modes (n=5, each). Microhardness was measured using Digital microhardness tester (FM7, Future-Tech Co., Tokyo, Japan) at the top and bottom surfaces of 2mm thick composite specimens after exposure to the same irradiation modes as the test of degree of conversion(n=3, each). For the microleakage test, class V cavities were prepared on the distal surface of the ninety extracted human third molars. The cavities were restored with one of the following irradiation modes: V2/60 seconds. V4/40 seconds, V6/30 seconds, VPD, OC and OR. Microleakage was asessed by dye penetration along enamel and dentin marigns of cavities. Mean polymerization shrinkage, mean degree of conversion and mean microhardness values for all groups at each time were analyzed using one-way ANOVA and Duncan's multiple range test, and using chisquare test for microleakage values. The results were as follows: ·Polymerization shrinkage was increased with higher light intensity in groups using VIP^™(Bisco) : the highset with 600mW/cm^2, followed by Pulse-delay, 400mW/cm^2 and 200mW/cm^2 groups. The degree of polymerization shrinkage was higher with Continuous mode than with Ramp mode in groups using Optilux 501^™ (Demetron/Kerr). ·Degree of conversion and microhardness values were higher with higher light intensity. The final degree of conversion was in the range of 44.7 to 54.98% and the final microhardness value in the range of 34.10 to 56.340. ·Microleakage was greater in dentin margin than in enamel margin. Higher light intensity showed more microleakage in dentin margin in groups using VIP^™ (Bisco). The microleakage was the lowest with Continuous mode in enamel margin and with Ramp mode in dentin margin when Optilux 501^™ (Demetron/Kerr) was used.

戰略的 經營을 爲한 生産戰略의 內容

朴相範,李敎相,吉鍾九 동국대학교 경영관리연구소 1989 經營經濟論叢 Vol.13 No.-

The enterprise can grow up and continue to exist, when it pursues the business strategy which properly copes with the management condition and the change of industrial structure. As the business strategy is a means of attaining the goal of the enterprise, it is an all-out plan containing all parts for long - term purposes, and it is a king of operation which harmonizes supply of resources with distribution. As the ultimate goal of the business strategy lies in having an advantage over a rival company, the substances of the competition strategy are a differentiation and an advantage and a focus strategy. The cost leadership strategy can minimize costs and make profits above the average through effective economy, accumulation of experience, cartailment of indirect cost and an outlay for advertisement. However, the cost leadership strategy can't disregard the quality of the goods and service. As the differentiation strategy has an advantage over a rival company through the quality of the goods and the design based on up - to- data technology, it can also make profits above the average in business. Even by the differentiation strategy, the advantage in cost can't wholly be disregarded. But only in the order of priority, the differentiation strategy gets the lead.. While the subject matters (substances) of the business strategy are a long - term object of the enterprise and a distribution of resources, the production strategy is a long - term goal that the production parts pursue. The goals of the production fields are productivity, delivery, quality, delivery speed, adaptability, design and so on. As these subjects are related to "trade off", the establishment of the subject on the order of priority is required. In other words, when the competition strategy of the enterprise consists in the advantage in cost, the goal of the production part lies in productivity and efficiency. And when the enterprise pursues the differentiation of the competition strategy, the object of the production part lies in quality, adaptability, diversification and design. In the courses of all the policy decisions, the competition strategy and the production strategy as a goal of part must be kept consistent and be harmonized.

全北特産 동아호박(冬爪)의 品種別과 部位別 一般成分 및 無機成分 含量 比較硏究

박성준,신민교,진성용 대한본초학회 1998 大韓本草學會誌 Vol.13 No.1

The findings of comparative analysis of the content of general and mineral components of Benincasae hispida by species and applled parts can be summarized as following. 1. When compared the content of general components, it proved that the BCB(Ⅱ) and SCB were excellent species in EXOCARPIUM BENINCASAE and although it was difficult to put one above the other, the BFB(Ⅰ) and BFB(Ⅱ) were a little bit excellent in FRUCTUS BENINCASAE and the BCB(Ⅰ) and BCB(Ⅱ) excellent in the content of fat, but the WCB in the contents of carbohydrate and protein in SEMEN BENINCASAE. 2. When compared the content of mineral components, it proved that the BCB(Ⅱ) and SCB were excellent species in EXOCARPIUM BENINCASAE and the BFB(Ⅰ) and BFB(Ⅱ) in FRUUCTS BENINCASAE and the BFB(Ⅰ) and BFB(Ⅱ) in SEMEN BENINCASAE. Summing up, in that the sample BCB(Ⅱ), BFB(Ⅰ) and BSB(Ⅰ),(Ⅱ) and BCB(Ⅱ), BFB(Ⅰ) and BFB(Ⅱ) which have much minerals proved to be excellent species, there all are considered as the most excellent species as CHEONGDONGWA.

광조사 방식이 복합레진 수복물의 변연누출에 미치는 영향

박은숙,김기옥,김성교 대한치과보존학회 2001 Restorative Dentistry & Endodontics Vol.26 No.4

저광도 중합법, 펄스 지연 중합법, 초고광도 중합법 등의 광조사 방식이 광중합형 복합레진 수복물에서 의 중합수축응력에 미치는 영향을 알아보기 위해 in vitro에서 미네 누출 실험을 하였다. 80개의 발거된 소구치의 협측면에 5급 와동을 형성하고, 600mW/㎠로 30초간 광조사하는 보통 광도 중합군 300mW/㎠로 60초간 광조사하는 저광도 중합군, 400mW/㎠로 2초간 광조사하고 5분간 기다린 후 800mW/㎠로 10초간 최종 중합시키는 펄스-지연 중합군, 그리고 1930mW/㎠의 광도로 3초간 광조사하는 초고광도중합군 등의 4개의 군으로 나누어 hybrid형의 광중합 복합레진을 충전하고 각 군의 방법대로 중합한 후, 변연의 0.5mm 외부에 nail varnish를 도포하고 37℃, 2% metylene blue용액에 24시간 침적시켰다. 시편을 아크릴릭 레진에 매몰한 후 수복물의 중앙에서 종절단하여 입체현미경하에서 그 단면을 관찰한 후 법랑질과 상아질 변연으로 나누어 색소의 침투도를 측정하여 다음과 같은 결과를 얻었다. 1. 펄스 지연 중합군의 색소 침투도는 법랑질과 상아질 변연 모두에서 보통광도, 저광도 및 초고광도 중합군과 유의한 차이를 보이지 않았다(p>0.05) 2. 상아질 변연에서 초고광도 중합군은 보통광도 중합군과 저광도 중합군에 비해 유의하게 높은 색소 침투도를 보였다(p<0.05) 3. 법랑질 변연에서의 4개 군의 색소 침투도는 서로 유의한 차이를 보이지 않았다(p>0.05) 4. 모든 군에서 상아질 변연에서의 색소 침투도는 법랑질군에서의 색소 침투도에 비해 유의하게 놓았다.(p<0.05)

TMA 가스센서용 마이크로히터 발열특성 연구

박성현,최우창,김성우,류지열,최혁환,이명교,권태하 경북대학교 센서기술연구소 1997 센서技術學術大會論文集 Vol.8 No.1

The microheaters with Si_(3)N_(4)(1500Å)/SiO_(2)(3000Å)/Si_(3)N_(4)( 1500Å) diaphragm were fabricated by thin film technology and silicon micromachining techniques. Pt and poly-Si(n+) materials were used as heater materials of microheater. Pt temperature sensor was fabricated to detect the temperature of microheaters. The thermal analysis including temperature distribution on diaphragm and power consumption of the microheater were executed by the FEM method and heat transfer equations. The power consumption of the Pt and poly-Si(n+) heaters were measured and compared to that of thermal analysis by FEM simulation.

스트렙토조토신으로 유도된 당뇨백서에서 미세혈관문합술후 혈관의 조직병리학적 연구

박성진,신상훈,정인교 대한악안면성형재건외과학회 2000 Maxillofacial Plastic Reconstructive Surgery Vol.22 No.2

Purpose : The purpose of this study is to estabilish clinical guidance of microvascular anastomosis in diabetic patients. This study was performed with experimental microvascular anastomosis in streptozotocin induced diabetic rats and observed histopathologic change and endohelial healing process. Materials and Methods : 70 Sprague-Dawley rats, weighting 200 to 250grams, were used for the experiment. 35 induced diabetic rats with streptozotocin and 35 control group were selected. After end-to-end carotid artery microvascular anastomosis was done, the experimental rats were sacrificed at different time interval (1st day, 3rd day, 1st week, 2nd, 4th, 6th and 8th week) for histologic examination. Light microscope observation was used in this study. Results : 1.Histopathologic changes are nearly the same healing process in two groups. But period of tissue reaction was faster in the control than diabetic group. 2.In endotheliall healing, control group started at 1 week after and completed at 4 weeks after, but diabetic group was observed partially at 4 weeks after and complete healing was not observed still at 8 weeks after. 3.In subintimal hyperplasia, control group was observed at 6 weeks after but diabetic group was observed at 6 weeks after and partially at 8 weeks after. 4.All groups showed severe inflammatory response in the early period. This respond is decreased at 2 weeks after in control group but still remained at 8 weeks after in the diabetic group. 5.In media, inflammatory response and degeneration were observed in early period. Regeneration of smooth muscle cell was observed at 1 week after in control group but 4 weeks after in the diabetic group. Conclusions : As the results of study, it could be thought that vascular regeneration process was not failured but delayed in the diabetes. It was considered that diabetes mellitus was not absolute contraindication of microvascular anastomosis.

MOSFET 동기정류회로의 특성 고찰 : S.M.P.S.에서 In S.M.P.S.

박성교,박종백 조선대학교 동력자원연구소 1996 動力資源硏究所誌 Vol.18 No.1

To improve the rectification efficiency, designed S.M.P.S. were fabricated by replacing diodes with power MOSFETs. The characteristics between these S.M.P.S. and existing diode-type S.M.P.S. at a load of 2.5[A]and 5[A] were compared. The results represent that independent synchronous gate-driven half bridge MOSFET rectifier obtaines a little increased total rectification efficiency, that is, increased 4.84% at a load of 2.5[A] and 1.55% at a load of 5[A] and self synchronous gate-driven flyback MOSFET retifier obstaines a little incerased total rectification efficiency, that is, increased 2.49% at a load of 2.5[A] and 3.47% at a load of 5[A], than diode-type S.M.P.S..

보울피더의 位相制御에 관한 硏究

박규성,김교형 嶺南大學校 工業技術硏究所 1995 工業技術硏究所論文集 Vol.23 No.1

Recently, people have been concerned about factory automation because of the development of the technology. Increasing of labor cost, machine is substituted for the worker who works at the simple assembly line. In this paper, we developed the controller using phase control for the performance improvement of the vibratory bowl feeder. This controller consists of TRIAC as switching device and UJT as gate trigger. Phase controller successfully controlled power to the load without loss.

실적공사비 개념을 이용한 하도급 적정공사비 예측시스템

박성철,구교진,현창택 대한건축학회 2004 대한건축학회 학술발표대회 논문집 - 계획계/구조계 Vol.24 No.1

The purpose of this study was to predict the subcontract fair cost of general construction by using the index. The index is caculated by data of Price Reserch Institute and CAK(Construction Association of Korea) is used in Time Series Anaysis. Subcontract fair cost is estimated by the index which predicted by Time Series Anaysis. and then, Regerssion Analysis performed in order to consider factor impact on cost. Throughout his study, we will be able to contribute to protect dishonor of subcontractor along with improvement of accuracy of subcontract cost budget in general construction

지하구내에 설치된 변압기의 극간 거리에 따른 연면방전 특성

박하용,임윤희,심낙순,이상교,송우창 三陟大學校 産業科學技術硏究院 2005 産業科學技術硏究論文集 Vol.10 No.-

The electric equipment of the recently building is established in underground of the building, it is the actual condition where the immediacy countermeasure preparation which is special regarding an electric equipment is deficient. The dissertation which it sees the case where the mold transformer which is established in the underground enclosure will be flooded minimizes the damage regarding the 1st disaster it could occur and a 2nd disaster in the test Book of Psalms to select the mold transformer which at fundamental phase of the research for is established on th actual underground enclosure, it analyzed the surface discharge voltage which it follows in distance and the electric current corrugated back. It appears with the fact that the recording surface discharge voltage where the analysis result electrode for interval will become larger increases, peek of discharge current highly there is a possibility of knowing the burden. Also, it caused by with increase of the surface discharge hour and the recording discharge hour when the interval of electrode for will become larger to increase also the insulation scandal damage will be augmented with the fact that it is thought.