• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.37 no.4
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• pp.278-286
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• 2011

Introduction: This study examined the predictability of new bone formation in the pneumatized maxillary sinus using only fibrin-rich blocks with concentrated growth factors as an alternative to bone grafts. Materials and Methods: Maxillary sinus augmentation was performed in thirty-three patients with a deficient alveolar bone height (mean 3.9 mm). All patients were treated consecutively with sinus membrane elevation via the lateral window approach and panoramic radiograms and cone-beam computed tomograms were taken to evaluate the remaining bone height and the new bone formation in the maxillary sinus, before and after surgery. Four biopsy specimens were taken at the time of implant consolidation (after an average of five months healing) and were stained by H & E and Trichrome staining. Results: None of the patients had postoperative complications during implant consolidation. After an average of 5 months since sinus augmentation, newly formed bone was observed in all cases by a radiographic evaluation. In 4 biopsy samples, newly formed bone was observed along the floor of the replaced bony window. The osteoblast lining and well distinguished Osteocytes in the lacunas were observed in the newly formed bone. Of the 74 implants (4 different surfaced implants - resorbable blast media-surfaced (RBM), Hydroxyapatite (HA) coated, acid-etched, sintered porous-surfaced implant) placed, one RBM implant failed. The success rate was 98.6% after a mean of 15 months. Discussion: These results suggest that maxillary sinus augmentation using fibrin rich block with concentrated growth factors is a successful and predictable technique.

• Journal of dental hygiene science
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• v.12 no.6
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• pp.689-695
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• 2012

The aim of this study was to elucidate the effects of concentrated growth factors (CGFs) on human gingival fibroblasts in vitro. Blood was collected from three male volunteers (average age 27 years). CGFs were prepared using standard protocols. The CGF exudates were collected at the following culture time points: 1, 7, 14, and 21 days. The levels of platelet-derived growth factor BB (PDGF-BB) and transforming growth factor ${\beta}1$ (TGF-${\beta}1$) in CGFs were quantified. The CGF exudates were then used to culture human gingival fibroblasts. The biologic characteristics of these fibroblasts were analyzed in vitro for 21 days. Platelet-rich plasma released the highest amounts of TGF-${\beta}1$ and PDGF-BB on the first day. The level of TGF-${\beta}1$ had decreased slightly by day 7, although the difference compared to levels at day 1 was not statistically significant. However, by days 14 and 21, levels of TGF-${\beta}1$ had dropped significantly compared to day 1 levels. The levels of PDGF-BB at days 7, 14, and 21 did not differ significantly from that measured on day 1. CGFs maintained the release of autologous growth factors for a reasonable period of time (7 days for TGF-${\beta}1$ and 21 days for PDGF-BB). Gingival fibroblasts treated with CGF exudates collected at day 14 reached peak viability and synthesized type I collagen. Furthermore, the CGF exudates exerted positive effects on the proliferation and differentiation of these cells at days 1, 7, 14, and 21. The findings of this study suggest that treatment with CGFs represents a promising method of enhancing mucosal healing following surgical procedures.

• Archives of Plastic Surgery
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• v.40 no.5
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• pp.530-535
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• 2013

Background Platelet-rich plasma (PRP) has more concentrated platelets than normal plasma (approximately 150-400${\times}10^3$ cell/dL). Platelets excrete several growth factors and cytokines that are associated with the healing and regeneration process. However, even though PRP is widely used, the mechanism or actual effect is presently unclear. Therefore, this study was performed to investigate the levels of growth factors and platelet concentration rate. Methods Autologous blood for preparing PRP was obtained from healthy subjects aged 25 to 35 years. The samples were divided into 4 experimental groups (inactivated whole blood, inactivated PRP, activated whole blood with thrombin and calcium chloride, and activated PRP). The platelet counts in the blood were analyzed and the growth factors were quantitatively measured. A statistical analysis was performed by using Dunn's multiple comparison test. Results In the blood cell analysis, the platelet count of the PRP group was approximately 4.25 times higher than that of the whole blood group. In the quantitative analysis of growth factors, the platelet-derived growth factor (PDGF)-AB, PDGF-BB, and transforming growth factor-${\beta}$ of the inactivated and activated PRP groups were higher than those of the inactivated and activated whole blood groups (P<0.05). Conclusions In this study, the platelet count and the levels of PDGF-AB and PDGF-BB in the PRP were determined. Further, more research is required on the bioactivity level of the growth factors secreted during the process of PRP preparation and the potency of growth factors that can be exerted physiologically in vivo.

• Journal of Korea Port Economic Association
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• v.28 no.1
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• pp.123-142
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• 2012

The purpose of this paper is to suggest a plan on succeeding together-Busan New Port & BJFEZ(that is, port hinterland development). This study deals with the terms of three connection growth factors which are a firm's subjective factors, a industrial environment factors, and a governmental policy factors. According to analysis results of the factors, a firm's subjective factors(4.11 score) are scored the most ones of connection growth factors of Busan New Port & BJFEZ, to be compared with a governmental policy factors(4.01 score). with a industrial environment factors(3.92 score). Therefore, first of all, Busan New Port & BJFEZ have to promote connection growth through as follows, a firm's subjective factors : (1) to procure competitiveness through establishment of connection growth model, (2) to promote concentrated marketing strategy & market response ability, (3) speedy meeting to customer's needs, (4) to procure reliability of Busan New Port & BJFEZ. And, the next, Busan New Port & BJFEZ have to promote connection growth through considering a governmental policy factors, a industrial environment factors.

• Journal of Korea Port Economic Association
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• v.31 no.1
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• pp.51-68
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• 2015

Recently, it has been emphasized that 'marine special economic zone' need to be designated and developed. Therefore, the purpose of this paper is to analyse on successful growth factors of 'marine special economic zone'. This study deals with the terms of three connection success factors which are a firm's subjective factors, a industrial environment factors, and a governmental policy factors. According to analysis results of the three successful growth factors, a firm's subjective factors(4.11 score) are scored at the most ones of the three successful growth factors, to be compared with a industrial environment factors(3.89 score). with a government policy factors(3.72 score). Therefore, first of all, it is important to enhance competitiveness of 'marine special economic zone' through as follows, a firm's subjective factors : (1) to procure concentrated market strategy and real market capacity, (2) to promote customer service, (3) to procure speedy satisfaction of customer needs and confidence, (4) to enhance competitiveness through standing in a trio of connection growth model. And, the next, we have to enhance competitiveness of 'marine special economic zone' through considering a industrial environment factors, that is, sustainable growth of marine industry, clustering of marine industry, expansion of infrastructure, etc., and a government policy factors, that is, leading law improvement and policy of leading 'marine special economic zone' designation and development, etc.,

• Journal of the Korean Society of Safety
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• v.14 no.4
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• pp.28-36
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• 1999

In this paper, A circular arc crackered plate in biaxially stretched sheets was investigated in the boundary element method. The applications of fracture mechanics have traditionally concentrated on crack problems under an mode I, straight crack. However, many service failures occur from growth of cracks subjected to mixed mode loadings. A rectangular plate with arc crack or slanted central crack, under biaxial tensile loading, was treated analytically and also solved numerically. The Results from BEM applying different loading conditions, crack length (a/W), arc angle($\alpha$) are presented and discussed. The stress intensity factors are evaluated by the techniques of the J-integral. The decomposition method, used to decouple the stress intensity factors in mixed mode problems, is implemented by a considering a small circular contour path around each crack tip. The BIE method was successfully applied to a circular arc crackerd plate problem, also slanted centre cracked plate under mixed mode.

• Journal of Korea Port Economic Association
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• v.17 no.2
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• pp.61-87
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• 2001

The purpose of this paper is to analyze the location, population growth. and cargo concentration of Korean port-cities. In the location theory, Sommer (1976) and McGee (1967) models are newly introduced, as are the Rimmer (1967), Bird (1965), Hoyle (1981) models. which were already introduced in previous studies from Korea. Analysis of population growth in the Korean port-cities is conducted using data from 1966 to 1998. Rimmer and Hoyle's concentration models are used to measure cargo concentration from 1966 to 2000. The main results of this paper are as follows: First, Korean ports are concentrated on the East Sea, the Southern Sea, and the West Sea. Their locations are closely related with the hinterland. the inland city, and growth of port-cities. In considering the foreign countrys' cases, Korean port-cities are similar to the models of Bird and Hoyle. Second, the populations of Ulsan and Pohang grew at the fastest rate in 1966-1998, while the port cities in the Honam and Jeiu region grew at much lower ratios. Most port cities are located near large industrial complexes. Third the growth rates of Gwangyang, Daesan, Pohang, Pyungtaeg, and Samchunpo increased, while those of Busan. Mukho, Masan, Mogpo, Yeosu, and Sokcho declined. Of particular note, the growth rate of Busan remained negative after the late 1980s. Fourth. empirical results using the Rimmer (1967) model indicate that Gwangyang, Daesan, Pyungtag, and Pohang have shown the concentration. But the deconcentration was shown from the Busan, Mukho, Janghang, Gunsan, Mogpo, Yeosu, Masan, Sokcho. and Jeju. Fifth, the concentration of ports located in West coast region has shown the mixed results between concentration and deconcentration except the concentration of early 1970s and 1990s. The concentration of ports located in East coast region has shown the concentration before the middle of 1980s. And deconcentration after the middle of 1980s have appeared. The Southern coast region has shown the continuous deconcentration except the partial concentration of early 1986. and 1991. Planners of Korean ports should find out the factors of concentration and deconcentration of each ports and should determine factors such as investment priority level. size and scope in order to ensure the balanced development of regional ports and port-cities.

• Microbiology and Biotechnology Letters
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• v.17 no.3
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• pp.231-235
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• 1989

Possibility of using microcarriers for the growth of a transformed human embryonic kidney cell line 293 was investigated. The cell grew well in a static culture such as T-flasks with medium of DME/F12 (3:1) mixture supplemented with 5% FBS, but it was most difficult to make the cells grow on microcarriers mainly due to the low attachment efficiency and poor spreading at initial stage of the culture. Consequently, 30-50% of the cells were lost upon inoculation into microcarrier suspension and significant fraction of the mirrocarrier became bald. The medium supplemented with the concentrated conditioned medium by hepatoma cell line HpG2 supported the active growth of the cells on microcarrier and the cells showed a very healthy and well spreading morphology. It was probable that some spreading and attachment factors of HpG2 conditioned medium were effective for 293 cells.

• Proceedings of the Technology Innovation Conference
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• 2006.02a
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• pp.226-247
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• 2006

Korea has accomplished remarkable economic growth based on the accumulating technological capability. Science and Technology policy aiming at quantitative growth has concentrated on S&T hardware infra-structure construction but it overemphasizes technological factors. This policy has not sufficiently reflected social and cultural elements that should be incorporated in S&T development process. Therefore many experts have been emphasizing the importance of science culture as an important ingredient of S&T policy. This paper aims at investigating how science culture could be diffused. Nowadays, many countries have a strong interest in science shop as an important instrument of science culture. Science shop, however, has been activated in European area so it is not familar to Korea. However there are already a few science shops in Korea. In this paper, we will investigate the Korea science shops. In particular, we will analyze the current status, organizational structure and problems of Korea science shops. we will draw some important policy implications to activate science shops and to strengthen S&T policies in Korea.

• Korean Journal of Remote Sensing
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• v.36 no.5_4
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• pp.1153-1166
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• 2020

The purpose of this study was to analyze the spatial correlation between the heat distribution map of the satellite imaging base and the factors that deepen the heat wave, and to explore the heat concentration area and the space where the risk of future heat wave may increase. The global Moran's I of population, land use, and buildings, which are the causes of heat concentration and heat wave deepening, is found to be high and concentrated in specific spaces. According to the analysis results of local Moran's I, heat concentration areas appeared mainly in large cities such as metropolitan and metropolitan areas, and forests were dominant in areas with relatively low temperatures. Areas with high population growth rates were distributed in the surrounding areas of Gyeonggi-do, Daejeon, and Busan, and the use of land and buildings were concentrated in the metropolitan area and large cities. Analysis by Bivarate Local Moran's I has shown that population growth is high in heat-intensive areas, and that artificial and urban building environments and land use take place. The results of this research can lead to the ranking of heat concentration areas and explore areas with environments where heat concentration is concentrated nationwide and deepens it, so ultimately it is considered to contribute to the establishment of preemptive measures to deal with extreme heat.