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멀티미디어 교수 학습 설계용 DB 구축과 프리젠테이션 자동화 프로그램의 구현
김덕룡(Deok-Ryong Kim),정승봉(Seung-Bong Chung),김병철(Byung-Chul Kim),오재철(Jae-Chul Oh) 한국정보과학회 1999 한국정보과학회 학술발표논문집 Vol.26 No.1B
정보화 사회에서 핵심적인 도구로 활용하게될 멀티미디어 매체는 교육분야에서 많은 잠재력을 지니고 있다. 정보화 사회에서 요구되는 교육을 수용하기 위하여 문자, 소리, 그림, 애니메이션, 동영상 등 다양한 형태의 멀티미디어 학습 자료가 학습자의 요구가 필요에 따라 제공될 수 있어야 하며, 학습자의 취향에 맞는 설명 방식이나 내용 전개 방식 등이 풍부하게 구비된 정보 인프라가 구축되어야 한다. 또한 교사들이 현장에서 학생들을 가르칠 때 교수내용을 다양한 방법으로 설계할 수 있도록 여러 컨텐츠들이 제공되어야 한다. 특히 여러 컨텐츠들을 함께 묶을 수 있는 사용하기 편리하고 표준화된 교육용 저작도구가 개발되어야 할 것이다. 따라서 본 연구에서는 교사들이 자신의 전공과목에 대한 지식만 있으면 누구나 쉽게 멀티미디어매체를 이용하여 학습자료를 설계 할 수 있도록 멀티미디어 교수 설계 DB 시스템을 구축하고, DB를 바탕으로 한 표준화되고 지능적인 프리젠테이션 프로그램을 구현하는데 목적을 두었다.
Sn-Ag-(Cu)계 Pb-free 솔더 조인트의 고온 크리프 물성 평가
김덕룡(Deok Ryong Kim),양성모(Sung Mo Yang),유효선(Hyo Sun Yu) 대한기계학회 2012 대한기계학회 춘추학술대회 Vol.2012 No.11
Soldering is very important packaging core technology in bonding process and recently the importance of soldering technology came to the fore. Also, Depending on the trend of miniaturization, lightweight and high performance of electronic devices, mechanical property evaluation is significantly considered such as high temperature creep property of solder joints. According to the environmental policy about previously used Sn-Pb eutectic solder, many research about the Pb-free is studied in the world. In this paper, in order to investigate the high temperature creep property of the solder joints about Sn-Pb eutectic solder and Sn-Ag-(Cu) types Pb-free solder, analyzed high temperature creep behavior using a shear punch-creep test equipment with reflow time(100, 300sec) and various load(5㎫ ~ 18㎫). As a result, a creep behavior of Sn-Ag-(Cu) types Pb-free solder is more superior to Sn-Pb solder and showed different creep behavior under various solder joints.
골막기원세포의 조골세포 분화과정에서 나타나는 혈관내피전구세포의 증식
김종렬(Jong-Ryoul Kim),송정호(Jung-Ho Song),김욱규(Uk-Kyu Kim),박봉욱(Bong-Wook Park),하영술(Young-Sool Hah),김진현(Jin-Hyun Kim),김덕룡(Deok Ryong Kim),조영철(Yeong-Cheol Cho),성일용(Iel-Yong Sung),변준호(June-Ho Byun) 대한구강악안면외과학회 2009 대한구강악안면외과학회지 Vol.35 No.4
Purpose : The purpose of this study was to examine the expression of various angiogenic factors during osteoblastic differentiation of periostealderived cells and the effects of osteogenic inductive medium of periosteal-derived cells on the proliferation of endothelial progenitor cells. Materials and methods : Periosteal-derived cells were obtained from mandibular periosteums and introduced into the cell culture. After passage 3, the cells were divided into two groups and cultured for 21 days. In one group, the cells were cultured in the DMEM supplemented with osteogenic inductive agent, including 50g/ml L-ascorbic acid 2-phosphate, 10 nM dexamethasone and 10 mM -glycerophosphate. In the other group, they were cultured in DMEM supplemented without osteogenic inductive agent. VEGF isoforms, VEGFR-1, VEGFR-2, and neuropilin-1 mRNA expression was observed. Human umbilical cord blood-derived endothelial progenitor cell proliferation was also observed. Results : The expression of VEGF isoforms was higher in osteogenic inductive medium than in non-osteogenic inductive medium. The expression of VEGFR-2 was also higher in osteogenic inductive medium than in non-osteogenic inductive medium. However, the expression of VEGFR-1 and neuropilin-1 was similar in both osteogenic inductive medium and non-osteogenic inductive medium. In addition, conditioned medium from differentiated periosteal-derived cells stimulated human umbilical cord blood-derived endothelial progenitor cell numbers compared to conditioned medium from non-differentiated periosteal-derived cells. Conclusion : These results suggest that in vitro osteoblastic differentiation of periosteal-derived cells has angiogenic capacity to support endothelial progenitor cell numbers.
골막기원세포에서 strontium에 의한 조골세포 표현형의 활성
김신원,김욱규,박봉욱,하영술,조희영,김정환,김덕룡,김종렬,주현호,변준호,Kim, Shin-Won,Kim, Uk-Kyu,Park, Bong-Wook,Hah, Young-Sool,Cho, Hee-Young,Kim, Jung-Hwan,Kim, Deok-Ryong,Kim, Jong-Ryoul,Joo, Hyun-Ho,Byun, June-Ho 대한악안면성형재건외과학회 2010 Maxillofacial Plastic Reconstructive Surgery Vol.32 No.3
This study investigated the effects of strontium on osteoblastic phenotypes of cultured human periostealderived cells. Periosteal tissues were harvested from mandible during surgical extraction of lower impacted third molar. Periosteal-derived cells were introduced into cell culture. After passage 3, the periostealderived cells were further cultured for 28 days in an osteogenic induction DMEM medium supplemented with fetal bovine serum, ascorbic acid 2-phosphate, dexamethasone and at a density of $3{\times}10^4$ cells/well in a 6-well plate. In this culture medium, strontium at different concentrations (1, 5, 10, and 100 ${\mu}g$/mL) was added. The medium was changed every 3 days during the incubation period. We examined the cellular proliferation, histochemical detection and biochemical measurements of alkaline phosphatase (ALP), the RT-PCR analysis for ALP and osteocalcin, and von Kossa staining and calcium contents in the periostealderived cells. Cell proliferation was not associated with the addition of strontium in periosteal-derived cells. The ALP activity in the periosteal-derived cells was higher in 5, 10, and 100 ${\mu}g$/ml strontium-treated cells than in untreated cells at day 14 of culture. Among the strontium-treated cells, the ALP activity was appreciably higher in 100 ${\mu}g$/ml strontium-treated cells than in 5 and 10 ${\mu}g$/ml strontium-treated cells. The levels of ALP and osteocalcin mRNA in the periosteal-derived cells was also higher in strontium-treated cells than in untreated cells at day 14 of culture. Their levels were increased in a dose-dependent manner. Von Kossa-positive mineralization nodules were strongly observed in the 1 ${\mu}g$/ml strontium-treated cells at day 21 and 28 of culture. The calcium content in the periosteal-derived cells was also higher in 1 ${\mu}g$/ml strontium-treated cells at day 28 of culture. These results suggest that low concentration of strontium stimulates the osteoblastic phenotypes of more differentiated periosteal-derived cells, whereas high concentration of strontium stimulates the osteoblastic phenotypes of less differentiated periosteal-derived cells. The effects of strontium on osteoblastic phenotypes of periosteal-derived cells appear to be associated with differentiation-extent.
배지 성분에 따른 인간 지방조직기원 CD146 양성 혈관내피세포의 증식 및 기능의 평가
박봉욱,하영술,김진현,조희영,정명희,김덕룡,김신원,김욱규,김종렬,변준호,Park, Bong-Wook,Hah, Young-Sool,Kim, Jin-Hyun,Cho, Hee-Young,Jung, Myeong-Hee,Kim, Deok-Ryong,Kim, Shin-Won,Kim, Uk-Kyu,Kim, Jong-Ryoul,Byun, June-Ho 대한악안면성형재건외과학회 2010 Maxillofacial Plastic Reconstructive Surgery Vol.32 No.6
Purpose: This study was to examine the proliferation and function of the adipose tissue-derived endothelial cells according to different culture medium conditions. Materials and Methods: Adipose tissue-derived CD146 positive endothelial cells were cultured in according to different culture mediums (DMEM culture medium with or without osteogenic inductive agents and EBM-2 culture medium with or without osteogenic inductive agents). The proliferation and function of the adipose tissue-derived endothelial cells was examined in different culture medium conditions. Results: Adipose tissue-derived endothelial cells formed tube-like structures on Matrigel in EBM-2 culture medium with or without osteogenic inductive agents. However, the cells did not form tube-like structures on Matrigel in DMEM medium with or without osteogenic inductive agents. After 24 hours of culture, among the culture medium using EBM-2, the proliferation of the cells were promoted in EBM-2 medium without osteogenic inductive agents than in EBM-2 medium with osteogenic inductive agents. However, 72 hours of culture, the proliferation of the cells were promoted in EBM-2 medium with osteogenic inductive agents than in EBM-2 medium without osteogenic inductive agents. Conclusion: These results suggest that the proliferation and function of the adipose tissue-derived CD146 positive endothelial cells could be maintained in EBM-2 with osteogenic inductive agents.
박봉욱,김신원,김욱규,하영술,김진현,김덕룡,성일용,조영철,손장호,김종렬,변준호,Park, Bong-Wook,Kim, Shin-Won,Kim, Uk-Kyu,Hah, Young-Sool,Kim, Jin-Hyun,Kim, Deok-Ryong,Sung, Iel-Young,Cho, Yeong-Cheol,Son, Jang-Ho,Kim, Jong-Ryoul,Byun, 대한악안면성형재건외과학회 2011 Maxillofacial Plastic Reconstructive Surgery Vol.33 No.5
Purpose: The periosteum is a well-known source of osteogenic precursor cells for tissue-engineered bone formation. However, cultured endothelial or endothelial-like cells derived from periosteum have not yet been investigated. This study focused on endothelial-like cell culture from the periosteum. Methods: Periosteal tissues were harvested from the mandible during surgical extraction of lower impacted third molars. The tissues were treated with 0.075% type I collagenase in phosphate-buffered saline (PBS) for 1 hr at $37^{\circ}C$ to release cellular fractions. The collagenase was inactivated with an equal volume of DMEM/10% fetal bovine serum (FBS) and the infranatant was centrifuged for 10 min at 2,400 rpm. The cellular pellet was filtered through a $100{\mu}m$ nylon cell strainer, and the filtered cells were centrifuged for 10 min at 2,400 rpm. The resuspended cells were plated into T25 flasks and cultured in endothelial cell basal medium (EBM)-2. Results: Among the hematopoietic markers, CD146 was more highly expressed than CD31 and CD34. The periosteal-derived cells also expressed CD90 and CD166, mesenchymal stem cell markers. Considering that the expression of CD146 was constant and that the expression of CD90 was lower at passage 5, respectively, the CD146 positive cells in passage 5 were isolated using the magnetic cell sorting (MACS) system. These CD146 sorted, periosteal-derived cells formed tube-like structures on Matrigel. The uptake of acetylated, low-density lipoprotein, labeled with 1,1'-dioctadecyl-3,3,3',3'-tetramethylindocarbocyanine perchlorate (DiI-Ac-LDL) was also examined in these cells. Conclusion: These results suggest that the CD146-sorted positive cells can be referred to as periosteal-derived CD146 positive endothelial-like cells. In particular, when a co-culture system with endothelial and osteoblastic cells in a three-dimensional scaffold is used, the use of periosteum as a single cell source would be strongly beneficial for bone tissue engineering.
배양된 인간 골막기원세포의 조골세포 분화과정에서 골기질 형성정도와 혈관내피세포성장인자 신호와의 상관관계
박봉욱,변준호,류영모,하영술,김덕룡,조영철,성일용,김종렬,Park, Bong-Wook,Byun, June-Ho,Ryu, Young-Mo,Hah, Young-Sool,Kim, Deok-Ryong,Cho, Yeong-Cheol,Sung, Iel-Yong,Kim, Jong-Ryoul 대한악안면성형재건외과학회 2007 Maxillofacial Plastic Reconstructive Surgery Vol.29 No.3
Angiogenesis is a essential part for bone formation and bone fracture healing. Vascular endothelial growth factor (VEGF), one of the most important molecules among many angiogenic factors, is a specific mitogen for vascular endothelial cells. VEGF-mediated angiogenesis is required for bone formation and repair. However, the effect of VEGF on osteoblastic cells during osteogenesis is still controversial. In recent days, substantial progress have been made toward developing tissue-engineered alternatives to autologous bone grafting for maxillofacial bony defects. Periosteum has received considerable interest as a better source of adult stem cells. Periosteum has the advantage of easy harvest and contains various cell types and progenitor cells that are able to differentiate into a several mesenchymal lineages, including bone. Several studies have reported the bone formation potential of periosteal cells, however, the correlation between VEGF signaling and cultured human periosteal cell-derived osteogenesis has not been fully investigated yet. The purpose of this study was to examine the correlation between VEGF signaling and cultured human periosteal-derived cells osteogenesis. Periosteal tissues of $5\;{\times}\;20\;mm$ were obtained from mandible during surgical extraction of lower impacted third molar from 3 patients. Periosteal-derived cells were introduced into the cell culture and were subcultured once they reached confluence. After passage 3, the periosteal-derived cells were further cultured for 42 days in an osteogenic inductive culture medium containing dexamethasone, ascorbic acid, and ${\beta}-glycerophosphate$. We evaluated the alkaline phosphatase (ALP) activity, the expression of Runx2 and VEGF, alizarin red S staining, and the quantification of osteocalcin and VEGF secretion in the periosteal-derived cells. The ALP activity increased rapidly up to day 14, followed by decrease in activity to day 35. Runx2 was expressed strongly at day 7, followed by decreased expression at day 14, and its expression was not observed thereafter. Both VEGF 165 and VEGF 121 were expressed strongly at day 35 and 42 of culture, particularly during the later stages of differentiation. Alizarin red S-positive nodules were first observed on day 14 and then increased in number during the entire culture period. Osteocalcin and VEGF were first detected in the culture medium on day 14, and their levels increased thereafter in a time-dependent manner. These results suggest that VEGF secretion from cultured human periosteal-derived cells increases along with mineralization process of the extracellular matrix. The level of VEGF secretion from periosteal-derived cells might depend on the extent of osteoblastic differentiation.
Polydioxanone/pluronic F127 담체에 유입된 골막기원세포의 조골활성
이진호,오세행,박봉욱,하영술,김덕룡,김욱규,김종렬,변준호,Lee, Jin-Ho,Oh, Se-Heang,Park, Bong-Wook,Hah, Young-Sool,Kim, Deok-Ryong,Kim, Uk-Kyu,Kim, Jong-Ryoul,Byun, June-Ho 대한악안면성형재건외과학회 2009 Maxillofacial Plastic Reconstructive Surgery Vol.31 No.6
Three-dimensional porous scaffolds play an important role in tissue engineering strategies. They provide a void volume in which vascularization, new tissue formation, and remodeling can occur. Like any grafted materials, the ideal scaffold for bone tissue engineering should be biocompatible without causing an inflammatory response. It should also possess biodegradability, which provides a suitable three-dimensional environment for the cell function together with the capacity for gradual resorption and replacement by host bone tissue. Various scaffolds have already been developed for bone tissue engineering applications, including naturally derived materials, bioceramics, and synthetic polymers. The advantages of biodegradable synthetic polymers include the ability to tailor specific functions. The purpose of this study was to examine the osteogenic activity of periosteal-derived cells in a polydioxanone/pluronic F127 scaffold. Periosteal-derived cells were successfully differentiated into osteoblasts in the polydioxanone/pluronic F127 scaffold. ALP activity showed its peak level at 2 weeks of culture, followed by decreased activity during the culture period. Similar to biochemical data, the level of ALP mRNA in the periosteal-derived cells was also largely elevated at 2 weeks of culture. The level of osteocalcin mRNA was gradually increased during entire culture period. Calcium content was detactable at 1 week and increased in a time-dependent manner up to the entire duration of culture. Our results suggest that polydioxanone/pluronic F127 could be a suitable scaffold of periosteal-derived cells for bone tissue engineering.