• Proceedings of the Korean Institute Of Construction Engineering and Management
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• autumn
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• pp.180-185
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• 2003

The increase of traffic over a bridge has been emerged as one of the most severe problems in view of bridge maintenance, since the load effect caused by the vehicle passage over the bridge has brought out a long-term damage to bridge structure, and it is nearly impossible to maintain operational serviceability of bridge to user's satisfactory level without any concern on bridge maintenance at the phase of completion. Moreover, bridge maintenance operation should be performed by regular inspection over the bridge to prevent structural malfunction or unexpected accidents front breaking out by monitoring on cracks or deformations during service. Therefore, technical breakthrough related to this uninterested field of bridge maintenance leading the public to the turning point of recognition is desperately needed. This study has the aim of development on automated inspection system to lower surface of bridge superstructures to replace the conventional system of bridge inspection with the naked eye, where the monitoring staff is directly on board to refractive or other type of maintenance .vehicles, with which it is expected that we can solve the problems essentially where the results of inspection are varied to change with subjective manlier from monitoring staff, increase stabilities in safety during the inspection, and make contribution to construct data base by providing objective and quantitative data and materials through image processing method over data captured by cameras. By this system it is also expected that objective estimation over the right time of maintenance and reinforcement work will lead enormous decrease in maintenance cost.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.36 no.5
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• pp.847-856
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• 2016

Recently, with a high level of economic growth, rapid urbanization, population, environment and housing problems were accompanied in Korea. In particular, the traffic problem has become a serious social problem. As the current transportation policy has been carried out, concentrating on traffic flow, in 2015, death rate for pedestrians while walking (1,795 persons) is 38.8% compared to entire death rate in car accident (4,621 persons), so there is need to solve it. Although, crosswalk should make pedestrian cross it safely, it has been made on the basis of the width of road without exact standard for current width of the crosswalk and the location of stop line. Moreover, in the area around many campuses or commercial facilities, crosswalks are set with not considering pedestrian passage, but designed uniformly. Therefore, the purpose of this study is to estimate reasonable dimension of crosswalk considering pedestrian traffic and walking speed and it makes the accident rate lower in the crosswalk, which has a lot of problems including decisions of vehicle traffic signal time, lack of pedestrian's signal timing, pedestrian's crossing of long-distance. The following are the methodology of the study. Firstly, for crosswalk calculation of specifications, examination relating existing regulations and researches dealing with crosswalk, pedestrians and stop line is needed. After analyzing problems of current width of crosswalk and stop line, present the methodology to calculation of specifications and basing on these things, calculation of specifications for crosswalk will be decided. In conclusion, the calculation of specification and improvement of stop line for crosswalk laid out in this study are expected to be utilized as base data in case of establishing relevant safety facilities and standards.

• Journal of Animal Science and Technology
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• v.49 no.1
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• pp.109-120
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• 2007

CLA was chemically synthesized by alkaline isomerization method using corn oil. CLA-TG was synthesized by chemical reaction using sodium methoxide. For the control, 10% of back fat among the total component was only added without the annex of CLA-TG. For the first treatment, 5% of CLA-TG among the lard component added into the press ham was replaced. For the 2nd, 3rd and 4rd treatments, 10%, 15% and 20% of CLA-TG was respectively replaced. Manufacture press ham using CLA-TG were vacuum packaged and then stored during 1, 7, 14, 21 and 28 days at 4℃. Samples were analyzed for shear force value, sensory evaluation, TBARS, fatty acid composition and CLA content. Shear force value of control was significantly higher than that of CLA-TG treatment groups(P<0.05). All treatments were increased by the passage of storage time. No remarkable differences were found in sensory properties among control and CLA-TG treatment groups. CLA-TG treatment groups showed significantly(P<0.05) lower TBARS value than the control. TBARS value was increased significantly during storage in all treatment. In the change of fatty acid composition, the contents of C14:0～C20:4 were decreased significantly by CLA-TG additive. Whereas the increase level of CLA-TG additive resulted in the significantly higher unsaturated fatty acid and CLA content. Summing up the a forementioned results, press ham manufacturing with CLA-TG additive was not affected in sensory evaluation. Also, it may be assumed that the high quality press ham can be manufactured with the extent of storage period and CLA accumulation.

• The Korean Journal of Pesticide Science
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• v.13 no.3
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• pp.190-196
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• 2009

The residues of abamectin 1.8% EC, resisted for control of pine wood nematode, Bursaphelenchus xylophilus in pine tree were surveyed in tissue of Pinus thunbergii and P. koraiensis after injection of a liquid formulation. Limits of detection of abamectin in tissue of P. thunbergii were $0.05\;mg\;kg^{-1}$ and mean recoveries at $0.5\;mg\;kg^{-1}$ trunk injection were 90.9% and 93.1% respectively in stem and trunk of P. thunbergii. Abamectin 1.8% EC, trunk injected in 15 m height P. thunbergii were detected in all stem (edible part of carrier insect of pine wood nematode, Monochamus alternatus) from 0.29 to $0.73\;mg\;kg^{-1}$ after 150 days injection. Amount of residue of abamectin 1.8% EC in 12.6 cm mean breast height diameter (DBH) P. thunbergii were variable depending on individual trees in natural forest. Amount of residues in lower and middle part of trunk were reduced with the passage of the injection time. In upper part of trunk were detected $1.84\;mg\;kg^{-1}$ on 30 days after injection however $0.65\;mg\;kg^{-1}$ on 15 days after injection and under detection limit on 100 and 180 days after injection in P. thunbergii. Bottom and middle parts of crown were detected $0.183\;mg\;kg^{-1}$ and $0.173\;mg\;kg^{-1}$ respectively on 180 days after injection in P. thunbergii. Mean residues of abamectin in crown and trunk were $0.80\;mg\;kg^{-1}$ and $0.30\;mg\;kg^{-1}$ on 170 days after trunk injection in 20 cm DBH and 9 m height P. koraiensis. Mean residues of abamectin in crown and trunk were $0.67\;mg\;kg^{-1}$ and $0.36\;mg\;kg^{-1}$ on 170 days after trunk injection in 15 cm DBH and 6 m height P. koraiensis.

• Korean Journal of Soil Science and Fertilizer
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• v.34 no.3
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• pp.178-184
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• 2001

A study was carried out to investigate the effect of rice bran and charcoal meal application on growth in rice and bacterial population in paddy soil. Four different treatments were applied ; at whole layer placement of rice bran 1.8Mg/ha(1.8WR), surface of rice bran 1.8Mg/ha(1.8SR), charcoal meal 3.0Mg/ha(3.00M), and combined rice bran 1.8Mg/ha and charcoal meal 3.0Mg/ha (1.8R+3.0C) through field experiment. $NH_4-N$ and $NO_3-N$ in soil were high in the application of 1.8SR and 1.8R+3.0C until heading stage after rice bran application. Amount of nitrogen absorbed by rice plant were the highest in application of 1.8R+3.0C, and the lowest in application of 3.0CM. Rice yield was no differences among treatments. A number of total aerobic bacteria were the highest in application of 1.8R+3.0C at panicle formation stage of rice. Cellulose decomposers were high in application of 1.8SR at tillering stage and in application of 1.8R+3.0C at harvesting stage. The microorganisms of ammonia-oxidizing and denitrifying bacteria showed higher number in the application of 1.8R+3.0C and 1.8SR at tillering stage than heading stage. Azotobacter had tendency to decreased with the passage of time, but increased when rice bran was added. Athiorhodacea were numerous in the application of 1.8WR, but a few in the application of 3.0CM through growing period of rice plant.

• The Journal of the Korea Contents Association
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• v.12 no.5
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• pp.311-322
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• 2012

Restoration materials used to investigate effects of fluorine such as enamel strengthening and anti-caries effects in several types of dental restoration materials were five kinds including Ionoseal(VOCO GmbH, Cuxhaven, Germany), Fuji Filling LC(GC Co. Tokyo, Japan), Quadrant Universal LC(CAVEX Holland BV, Netherlands), PermaCem$^{(R)}$(DMG, Hamburg, Germany) and Dyract$^{(R)}$ AP(Dentsply GmbH, Germany), and the amount of fluorine-releasing was measured with ICS-5000 Reagent-FreeTM Ion Chromatography(RFICTM, Dionex, U.S.A.). The results of this study are as follows. 1. In all types of restoration materials, the amount of fluoride-releasing was reduced with time passage and it was declined sharply to show significance in four weeks. Fuji Filling LC(12.445PPM) or resin-reinforced glass ionomer and PermaCem$^{(R)}$(16.121PPM) or compomer were found to release fluorine for a long term(P<.001). 2. Ionoseal(0.887PPM) or glass ionomer and Quadrant Universal LC(0.957PPM) or composite resin released a few fluorine of 1PPM or less than 1PPM after one week, and Dyract$^{(R)}$ AP or compomer released fluorine of 8.631PPM in one week and its amount of releasing decreased dramatically in two and four week by recording 0.175PPM and 0.116PPM, respectively. Therefore, the effect of releasing fluorine in four weeks was observed to be poor (P<.001). 3. Fuji Filling LC or resin-reinforced glass ionomer and PermaCem$^{(R)}$ or compomer released fluorine of 33.372 and 1.902PPM, respectively in one week and their amount of releasing increased to be 36.371 and 18.223PPM, respectively in two weeks. So, their amount of fluorine-releasing recorded the highest levels in two weeks(P<.001).

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.25 no.3
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• pp.55-66
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• 2020

Near-inertial waves (NIW) which are primarily generated by wind can contribute to vertical mixing in the ocean. The energetic NIW can be generated by typhoon due to its strong wind and preferable wind direction changes especially on the right-hand side of the typhoon. Here we investigate the generation and distribution of NIW using the output of a real-time ocean forecasting system. Five-year model outputs during 2013-2017 are analyzed with a focus on cases of energetic NIW generation by the passage of three typhoons (Halong, Goni, and Chaba) over the East Sea. Calculations of wind energy input (${\bar{W}}_I$), and horizontal kinetic energy in the mixed layer (${\bar{HKE}}_{MLD}$) reveal that the spatial distribution of ${\bar{HKE}}_{MLD}$, which is strengthened at the right-hand side of typhoon tracks, is closely related with ${\bar{W}}_I$. Horizontal kinetic energy in the deep layer (${\bar{HKE}}_{DEEP}$) shows patch-shaped distribution mainly located at the southern side of the East Sea. Spatial distribution of ${\bar{HKE}}_{DEEP}$ shows a close relationship with negative relative vorticity regions caused by warm eddies in the upper layer. Monthly-mean ${\bar{HKE}}_{MLD}$ and ${\bar{HKE}}_{DEEP}$ during a typhoon passing over the East Sea shows about 2.5-5.7 times and 1.2-1.6 times larger values than those during summer with no typhoons, respectively. In addition, their magnitudes are respectively about 0.4-1.0 and 0.8-1.0 times from those during winter, suggesting that the typhoon-induced NIW can provide a significant energy to enhance vertical mixing at both the mixed and deep layers during summer.

• The Korean Journal of Malacology
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• v.15 no.1
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• pp.31-39
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• 1999

This study was aimed to describe the population dynamics and secondary production of Tapes philppinarum on Chohwa and Toksan tidal flats in Kwangyang Bay, from June 1994 to July 1995. The size distributions in shell length showed bimodal patterns from June 1994 to April 1995. Thereafter the distribution changed to the passage of time, indicating an increase in shell length. The mean densities decreased gradually with month. Chohwa A sustained highestdensity, followed by Chohwa B, Toksan C, and Toksan D. The recruitment of new year class occurred first on the upper tidal flat, and then moved to the lower tidal flat. The mean biomass in flesh dry weight of each year class increased in spring just before the spawning period, and thereafter decreased progressively. Annual mean biomass wasrecorded as 170.7 g m$\^$-2/ at Chohwa A, 220.7 g m$\^$-2/ at Chohwa B, 21.8 g m$\^$-2/ at Toksan C, and 45.2 g m$\^$-2/ at toksan D. Annual productions of Ruditapes philippinarum were estimated as 259.72 g m$\^$-2/ yr$\_$-1/ at Chohwa A, 359.79 g m$\^$-2/ yr$\_$-1/ at Chohwa B, 45.02 g m$\^$-2/ yr$\_$-1/ at Toksan c, 68.88 g m$\^$-2/ yr$\_$-1/ at Toksan D. Annual productions were much higher on Chohwa tidal flat than those on Toksan tidal flat. While P:B ratio were higher on Toksan tidal flat as 1.70 than those on Chohwa tidal flat as 1.58. In conclusion, the Chohwa tidal flat showed higher biomass and producion of Ruditapes philippinarum, whereas the Toksan tidal flat showed higher P:B ratio. The total amount of potential food might influence on the density, biomass nad produciton, whereas the amount of food and space per individual might influence on the growth rate and P:B ratio.

• Korean Journal of Agricultural Science
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• v.14 no.2
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• pp.263-271
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• 1987

The cyclical trend and seasonal variations of chestnut prices have been analyzed to find out the chestnut price fluctuation in Korea during 1966-1985. The optimum prices, production, and plantation area for the next twenty five years (1986-2010) have been forcasted by the derived equation models. The results of study can be summarized as follows: 1. The chestnut prices were increased by 14.67 percent per annum during 1966-1972, an d decreased by 9.24 percent during 1973-1985, due to the excessive production of chestnut. 2. The chestnut prices showed the lowest price during the harvesting season, especially in October (89.1), and highest in July (109.1). Seasonal fluctuation of chestnut prices were 0.0837 (C.V value) during 1966-1975, and 0.0706 during 1976-1985. Such a seasonal fluctuation of chestnut prices tends to be even with the passage of time. 3. The equation model of predicted chestnut prices was derived as follows : PR=117788.088 - 7.60 TC/Pop + 6.585 GNP/Pop The chestnut prices will be the lowest in 1988, but increased rapidly thereafter. 4. The equation model of optimum chestnut production was derived as follows : $${\ell}n\;PD/Pop=-8.5147-0.8267{\ell}n\;PR+3.3063{\ell}n\;GNP/Pop$$ To maintain optimum chestnut prices according to this model, chestnut production should be 133,000 ton for 1988, and 1,899,000 ton for 2010. 5. Optimum chestnut plantation area will be 4,000 ha in 1988, and thereafter total plantation area will be up to 57,400 ha in 2010.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.29 no.3
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• pp.197-205
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• 2007

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.