자가 Fibrin Glue와 연골세포를 이용한 연골조직 공학 기법에 관한 연구

홍성표,범진식,박재경,김진영,이두형 大韓成形外科學會 1999 Archives of Plastic Surgery Vol.26 No.3

Neomorphogenesis of cartilage using chondrocyte-polymer constructs is a potential source for development of cartilage reconstruction. Current tissue engineering techniques of neocartilage rely on in vivo implantation of polymer-chondrocyte constructs. The purpose of this study was to find a way to bioengineer cartilage in vitro by entrapping chondrocytes in a molded autologous fibrin glue. Chondrocytes isolated from the cartilage of rabbit joints were combined with fibrinogen extracted by a single cryoprecipitation of autologous plasma, and they were then polymerized with thrombin to create a fibrin glue with a final cell density of 2.5x10?? cells/ml. The collagen for a control study was used as a polymer. The polymer-chondrocyte constructs were cultured for 4 weeks and the fibrin-chondrocyte constructs molded in the shape of a human ear were cultured for 6 weeks in vitro. Morphometric, histochemical, and histomorphometric analysis including glycosaminoglycan quantitation confirmed the following results: 1) Highly-concentrated autologous fibrinogen was easily extracted by a single cryoprecipition of autologous olasma. 2) The fibrin-chondrocyte constructs demonstrated the presence of actively proliferating chondrocytes with the production of cartilaginous matrix(collagen and glycosaminoglycan) at 1 week after culture, as well as gross and histologic evidence similar to those of normal cartilage at 3∼4 weeks after culture. 3) The collagen-chondrocyte constructs demonstrated lower degrees of hardness and transparency, as well as a lower density of cells and glycosaminoglycan during the culture period. 4) Neocartilage generated from fibrin-chondrocyte constructs in the shape of a human ear nearly retained their original configuration and size without degeneration for 6 weeks of culture in vitro. This study demonstrated a novel method for bioengineering the molded cartilage in vitro using autologous fibrin glue as a matrix scaffold. The generated cartilage showed gross and histologic evidence similar to those of normal cartilage, retaining the original gross dimension. With further refinement, this may be a new application of tissue engineering for the reconstruction of cartilage.

자외선 경화형 불포화 폴리에스테르 수지의 합성과정이 저장안정성에 미치는 영향

洪錫杓,崔相久 全北大學校 1992 論文集 Vol.34 No.-

Storage stability of UV curable unsaturated polyester was studied in accordance with synthesis process and inhilitor charging. When resin was synthesized at 160∼170℃, storage stability was mainly influencd by reaction time. THQ showed best storage stability among inhibitors. Appropriate charge of THQ was 150ppm in initial of first reaction, 350ppm in initial of second reaction and 350ppm in SM thinning.

미취업 이공계 석·박사 지원정책의 경제적 효과분석 : 인적자본 투자수익률을 중심으로

홍성표,이성규 한국노동경제학회 2003 勞動經濟論集 Vol.26 No.3

본 연구는 Mincer와 Ben-Porath의 최적인적자본 축적모형을 이용해서 외환위기 이후 급증한 이공계 석·박사 학위 졸업자들의 미취업 사태를 완화하고자 도입된 정부의 인턴연구원 지원사업이 동 사업으로 혜택을 받은 석·박사 학위자들의 인적자본 축적에 어느 정도의 영향을 미쳤는지를 분석하였다. Tobit 모형을 사용한 추정 결과에 따르면 인턴사업에 의한 인적자본 투자수익률이 인턴사업의 특성과 지원 대상인 고급과학기술인력을 분석 대상으로 하고 있다는 점을 감안한다면 투자수익률이 큰 것으로 나타났다. 이러한 결과는 정부가 미취업 고급인력의 인적자본의 진부화(obsolescnence) 속도를 늦추고 더 나아가서 현장실습을 통해서 새로운 인적자본을 축적할 수 있는 기회를 제공했던 인턴사업이 성공적이었음을 의미한다. 따라서 지식기반사회에서 국가경쟁력의 핵심인 고급인력의 구조적 실업을 완화시킴으로써 인적자본 축적에 큰 기여를 하고 있는 인턴사업의 경제적 효과를 극대화시킬 수 있는 여러 가지 방안들이 정책적으로 강구되어야 할 것이다. The study analyzes how effective the Government Internship Program has been on accumulation of the human capital. The Program was designed under the foreign exchange crisis to support the new, but unemployed graduates with MA or Ph.D degree in the science and the engineering fields. The survey data is collected from the participa nts in the Program. The Tobit model is estimated to find the economic effects of t he Program in terms of the rate of return of investment in the human capitals of the intern researchers. Considering that the Program is tentative and that the h uman capitals of the participants are easily obsolescent, the rate of return is observ ed to be substantially large. These results imply that the Internship Program has been successful in terms of providing not only the researchers with the opp ortunity to accumulate the human capital by means of the on-the -jop-training, the also the institutes or the firms with the opportunity to utili ze the high-quality researchers at the low cost.

NATM 통신구터널 지보패턴에 관한 연구

홍원표,한중근,이상곤 중앙대학교 기술과학연구소 1998 기술과학연구소 논문집 Vol.28 No.-

우리나라에서 NATM 통신구터널에 적용되고 있는 암반분류형태 및 지보패턴은 지하철 도시터널과 같이 대형단면 터널에 적용되는 기준을 그대로 적용하고 있는 실정이다. 그러나 NATM 통신구터널은 대개 소형단면터널이며 깊은 tal도에서 시공되는 것이 일반적이다. 따라서 NATM 통신구터널의 설계 및 시공시에는 적절한 지반암반의 정량화 및 공학적 분류법을 별도로 마련하여 이 분류에 근거한 적합한 지보모델을 제시할 필요가 있다. 본 연구에서는 NATM 통신터널에 적합한 표준지보패턴과 암반분류모델을 7등급으로 구분 제시하며 제시된 암반 분류등급별 지보패턴에 대한 합리성이 터널시공사례에 대한 유한차분해석을 통해 검증된다. The classification of rock-mass and its reinforcement pattern used for Communication Cable Vault in Korea have been actually used such methods that applied to largesectional tunnel construction such as Subway urban-tunneling. However, in the case of small sized tunnel works for Communication Cable Vault which are generally adopted at deep depth, the proper reinforcing support model should be suggested on the basis of quantitative classification of rock-mass for design and construction. This paper presented standard reinforcement pattern and classification model of rock-mass for NATM of Communication Cable Vault. They are divided in to 7-categories of grades and reasonability of these suggestion is ascertained from numerical analysis for the construction of these suggestion is ascertained from numerical analysis for the construction of Tunnel.

메모리 공유형 다중 프로세서의 동기화를 위한 Spin-Lock 기법의 성능 분석

홍춘표,이종임,남상균 대구대학교 과학기술연구소 1997 科學技術硏究 Vol.4 No.3

Most of the shared-memory multiprocessor system provide a hardware primitive for supporting mutually exclusive accesses to shared data. The hardware primitive consists of instructions that atomically read and write a single memory location. When a processor is accessing a shared data, the lock is set to busy, and other processors must wait until the lock is released. This paper analyse the characteristics of four spin-lock alternatives, and compare the performance of the proposed scheme through the simulation on shared-memory multiprocessor (Sequent-Balance). The simulation results show that all the spin-lock alternatives for synchronization degrade overall performance as the number of spinning processors increases. In addition, a variant of Ethernet backoff scheme shows good performance even for large numbers of spinning processors. Because of its simplicity, backoff scheme has better performance when there is no contention for the lock.

카본블랙의 종류 및 배합제의 혼합방법에 따른 NR/HNBR 블렌드의 특성

洪錫勻,庾吉祥,金鍾石,崔相久 全北大學校 1992 論文集 Vol.34 No.-

It was studied how physical properties, heat resistance, oil resistance, ozone resistance of NR(natural rubber)/HNBR(hydrogenated acrylonitrile butadiene rubber) blends influenced by different mixing methods and various carbon black types. Of the various mixing methods, masterbatch mixing method was better than others in considering the overall stabilities of the compounds. The most important parameter which influenced on heat, oil and ozone resistance was rubber material than sorts of carbon black. The resistance for heat, oil and ozone of NR compounds were improved by blending HNBR and these effects were revealed clearly at elevated temperatures.

佛國寺 造景의 諸 問題

洪光杓,李相潤 동국대학교 사찰조경연구소 1999 寺刹造景硏究 Vol.7 No.-

The purpose of this study was to grasp the problem and suggest the answer in the landscape of Pulguksa Temple. The result of this study can be summarized as follows: 1. The oval Kupumryonji(ninth rank lotus pond) in Pulguksa temple is the lotus pond and shodow reflection pond. It was symbolized heavenly paradise and was reflected the shadows of Buddha, pagoda and mountain on its surfaces. It must be reconstruct for the identity of the landscape of Pulguksa Temple. 2. Although the stone platforms of Pulguksa temple were constructed with traditional construction method, particularly the one of west corridor in Kuekrakjon territory had many problems. It must be reconstruct with the traditional construction method. 3. It were 2 ponds differed with the traditional pond pattern in the entrance space from Iljumoon to main building. These must be reconstruct with the traditional pond pattern.

환경위해성평가기법의 응용방안

홍상표 청주대학교 산업과학연구소 2003 産業科學硏究 Vol.20 No.2

Most EIA(environmental impact assessment) programs require the consideration of human health impacts This paper examines how, why, and to what extent health impacts are analysed in environmental impact assessments An empirical study of EIS(environmental impact statements) found that more than half didn't mention about health impacts. This paper investigates these problems and provides recommendations to improve human health impact assessment, using strategic environmental assessment, qualitative health data, health outcomes in addition to cancer, and precautionary approach to risk

수도권 매립지 粘土遮水膜의 透水特性에 관한 연구

洪相杓,金丁勖 서울大學校 環境大學院 1993 環境論叢 Vol.31 No.-

0.412 MeV 감마선에 대한 원주형 NaI(Tl) 섬광체의 총 절대검출효율 계산

홍권표,신희성,이상윤,노성기 대한방사선 방어학회 2002 방사선방어학회지 Vol.27 No.4

Total absolute detection efficiencies of a 7.62 cm(dia.) and 7.62 cm(height) cylindrical NaI(Tl) crystal have been calculated for 0.412 MeV r -rays from a source(point, circular disk, square and line type). In this calculation the linear energy-absorption coefficients based on Hubbell's data have been considered and then calculated total absolute detection efficiencies compared with those from Grosjean and Bossaert. Besides, the source axis-to-detector axis shift distance which, could give rise to about 0.05% deviation in the total absolute detection efficiencies has been calculated for a line-type source of 0.5 cm in its length when a source-to-detector distance is 5 cm. It is revealed that the total absolute detection efficiencies obtained in this study are considerably different from those of Grosjean and Bossaert. In addition it is found that the deviation induced due to an imperfect center of a line type source may be within 0.05% if the shifted discrepancy is no larger than 1.74mm.