• Proceedings of the Earthquake Engineering Society of Korea Conference
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• 2001.04a
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• pp.387-393
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• 2001

Installing vibration control devices in the structure rises as a solution instead of increasing structural strength considering construction cost. Especially, viscoelastic dampers show excellent vibration control performance at low cost and are easy to install in existing structures compared with other control devices. Therefore, cost-effectiveness of structure with viscoelastic dampers needs to be evaluated. Previous cost-effectiveness evaluation method for the seismically isolated structure(Koh et al., 1999;2000)is applied on the building structure with viscoelastic dampers, which combines optimal design and cost-effectiveness evaluation for seismically isolated structures based on minimum life-cycle cost concept. Input ground motion is modeled in the form of spectral density function to take into account acceleration and site coefficients. Damping of the viscoelastic damper is considered by modal strain energy method. Stiffness of shear building and shear area of viscoelastic damper are adopted as design variables for optimization. For the estimation of failure probability, transfer function of the structure with viscoelastic damper for spectral analysis is derived from the equation of motion. Results reveal that cost-effectiveness of the structure with viscoelastic dampers is relatively high in how seismic region and stiff soil condition.

• Proceedings of the Korean Geotechical Society Conference
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• 2005.03a
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• pp.49-56
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• 2005

The negative skin friction on piles, which are installed in currently consolidating soft deposits, creates significant problems on the stability of pile foundations. This study investigated whether or not the pile foundation designs were appropriate in soft deposits with large amount of consolidation settlement. The final settlements of the grounds along the pile depth were estimated by the soil parameters obtained from the laboratory tests and by the field-measured settlement curves, if they were available. The displacement of the piles along the pile depth was estimated by both the load transfer method and the numerical method. Both methods gave similar locations of neutral points and magnitudes of the maximum axial forces. The movements of the ground and the piles were compared to calculate the down drag acting on piles. For the piles whose bearing capacities were less than the design loads including the down drag, slip layer coatings and/or incrementing of the penetration depth into the bearing stratum were proposed to improve the piles capacities.

• Journal of architectural history
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• v.16 no.3
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• pp.57-74
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• 2007

Jeoksimto which was build up as the reinforcement establishment made with the soil under the cornerstone in the site of tile-capped building is the representative construction technique which become popular in the Sabi capital era after the Wungjin capital era. Especially from the fact that no site of tile-capped building with this Jeoksimto has been found in the Silla area, we can see the originality Baekje technique. We can analogize the specialization of Josagong (造寺工) (craftsman building the temple) and the diversity of technique, on the basis of the technique raising the ground level which is different with the middle gate site of Neung-sa and the Hall enshrining Buddha site in Buyeo. Moreover, we can have the confidence the dispatch of craftsman and the transmission of building technique from the Buyeo area to the Iksan area through the fact that the construction techniques of Jeoksimto in both area are almost the same. However the concerns in the construction archaeology are necessary because almost no study for Jeoksimto has been conducted and the term of Jeoksimto also is unfamiliar even if excavation of Baekje Jeoksimto in the several remains.

• Journal of Plant Biotechnology
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• v.30 no.3
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• pp.269-273
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• 2003

In order to develop an efficient micropropagation protocal for Eucalyptus pellita, on in vitro culture system has been was established by inducing axillary buds from greenhouse stock materials. Among 6different media tested, DKW medium was the best ot induce bast induce both shoot proliferation and growth. Average number of proliferated shoots of 403per explant was obtained at the concentration of 0.1mg/LBA. Most of the stem materials excreted phenolic compounds at the proximal part of the explant and caused darking of the media. Therefore, it was necessary to transfer frequently to a fresh medium and/or to add activated charcoal at the concentration of 0.02％(w/v). Generally on vitro roots were formed easily on 1/2DKW medium with NAA treatment. All the explants rooted at the medium containing 0.2mg/L NAA and displayed vigorous root growth in vitro culture conditions. After transferred to an artificial soil mixture (peatmoss: vermiculrite: perlite, 1:1:1, v/v/v) in the greenhouse, most rooted plantlets survived well without any morphological abnormalities. The results show that the species can be micropropagated effectively by the application of axillary bud culture system.

• Korean Journal of Plant Tissue Culture
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• v.22 no.6
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• pp.307-310
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• 1995

Cotyledon and epicotyl explants of P. aridum and P. zonale formed calli when cultured on MS medium supplemented with 2 mg/L NAA and 0.2 mg/L BA. Calli were subcultured on the same medium Upon transfer to MS medium with 0.1 to 0.5mg/L NAA and 0.25 to 2mg/L BA for P. aridum 0.1 to 0.5mg/L NAA and 1 to 2mg/L BA for P. zonale subcultured calli gave rise to the greatest number of shoots (0.78 shoot for P. aridum and 0.65 shoot per explant for P. zonale, respectively).Most shoots produced roots when cultured on 1/2MS basal medium. The regenerates were transferred to potting soil and grown to materity in a greenhouse.

• Journal of Plant Biotechnology
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• v.33 no.4
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• pp.263-270
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• 2006

Pongamia pinnata Pierre is a tree legume, having potential in production of raw material for biodiesel. A protocol for in wk propagation of this plant was standardized using seedling explants. Growth regulators (GR) including gibberellic acid $(GA_3),\;N^6-benzylaminopurine(BA)$, thidiazuron (TDZ), and Adenine sulphate (Ads) were tested for optimum germination of seeds. Removal of seed coat prior to germination, controlled fungal growth partially but enhanced bacterial growth. Antibiotic cefotaxime was ineffective in controlling bacterial contamination. Seedling derived nodal explants and cotyledon nodes with attached cotyledons were excised and cultured for induction of shoots. Optimum sprouting and multiplication of shoot buds were obtained in MS medium supplemented with $8.88{\mu}M$ BA. These buds differentiated and rooted on medium devoid of GR. Optimum growth of Pongamia seedling was obtained in cotton plugged culture vessels. Reculturing of the cotyledon node explants produced more shoots from the same site. This process of removing shoots and reculturing of cotyledon node was followed for eight passages yielding 4 to 8 shoots in each cycle. The shoots (75%) rooted on half strength MS basal medium supplemented with 0.22% charcoal. All plants survived on transfer to soil. This is the first report on in vitro regeneration of Pongamia pinnata. This report demonstrates the possibility of coupling more than one parameter in single experiment to hasten the process of standardization. The process of cycling the nodal explant repeatedly for production of large number of shoots from single meristem may find application in genetic transformation experiments wherein meristems are used for transformation.

• Journal of Plant Biotechnology
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• v.7 no.3
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• pp.155-160
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• 2005

Haloxylon recurvum (Locally known as Khar) is drought and salt tolerant plant of Thar Desert. This plant is a major biomass producer and has economic and ecological importance for the region. There is need for study on biology, propagation and genetic improvement for utilization of this plant for reclamation of saline soils. We report here on in vitro propagation of Haloxylon recurvum (Moq.) using nodal explant. Secretion of phenolic compound from explants was a major constraint for establishment of culture. This was checked by thorough washing and quick transfer of explant on fresh culture medium. Juvenile nodal explant with leaves was found suitable for culture establishment. Benzy-ladenine($4.0\;{\mu}M$) incorporated in Murashige and Skoog (MS) medium with additives (50 mg/L ascorbic acid and 25 mg/L each of adenine sulphate, arginine and citric acid) induced multiple shoots from nodal explant. Addition of $1.0\;{\mu}M$ naphthalene acetic acid (NAA) in combination with $4.0\;{\mu}M$ BAP improved the growth of axillary shoots. Further shoot amplification was achieved by repeated subculture of mother explants on fresh medium. Forty percent of the micropropagated shoots rooted on half-strength MS medium with $4.0\;{\mu}M$ indolebutyric acid (IBA) and 100 mg/L activated charcoal, at $28{\pm}2^{\circ}C$ and $60\%$ RH. Sixty percent of these plantlets were hardened in green house.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.21 no.6
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• pp.355-366
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• 2009

In the present study, fuel cell driven ground source heat pump system is applied to a large community building and performance of the heat pump system is computationally analyzed. Conduction heat transfer between brine pipe and ground is analyzed by TEACH code to predict the performance of heat pump system. Predicted COP of the heat pump system and the energy cost were compared with variation of the location of the objective building the water saturation rate of soil and the driven powers of heat pump system. Significant reduction of energy cost can be accomplished by employing the fuel cell driven heat pump system in comparison with the late-night electricity driven system. It is due to the low electricity production cost of fuel cell system and the application of recovered waste heat generated during electricity production process to the heating of large community building.

• Bulletin of the Korean Chemical Society
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• v.29 no.7
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• pp.1323-1325
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• 2008

The acetylene black (AB) was dispersed into water in the presence of dihexadecyl hydrogen phosphate (DHP) via ultrasonication, resulting in a stable and well-distributed AB/DHP suspension. After evaporation of water, an AB/DHP composite film-modified electrode was prepared. The electrochemical responses of $K_3$[Fe$(CN)_6$] at the unmodified electrode, DHP film-modified electrode and AB/DHP film-modified electrode were investigated. It is found that the AB/DHP film-modified electrode possesses larger surface area and electron transfer rate constant. Furthermore, the electrochemical behaviors of 1-naphthylacetic acid (NAA) were examined. At the AB/DHP film-modified electrode, the oxidation peak current of NAA remarkably increases. Based on this, a sensitive and convenient electrochemical method was proposed for the determination of NAA. The linear range is in the range from $4.0 {\times} 10^{-8}\;to\;5.0 {\times} 10^{-6}$ mol $L^{-1}$, and the detection limit is $1.0 {\times} 10^{-8}$ mol $L^{-1}$. Finally, this new sensing method was employed to determine NAA in several soil samples.

• Journal of Korean Society for Atmospheric Environment
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• v.17 no.E2
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• pp.43-51
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• 2001

A report by the national research council in the United States suggested that many lung cancer deaths each year be associated with breathing radon in indoor air. Most of the indoor radon comes directly from soil beneath the basement of foundations. Recently, radon released from groundwater is found to contribute to the total inhalation risk from indoor air. This study presents the quantitative assessment of human exposures to radon released from the groundwater into indoor air. At first, a three-compartment model is developed to describe the transfer and distribution of radon released from groundwater in a house through showering, washing clothes, and flushing toilets. Then, to estimate a daily human exposure through inhalation of such radon for an adult. a physiologically-based pharmacokinetic(PBPK) model is developed. The use of a PBPK model for the inhaled radon could provide useful information regarding the distribution of radon among the organs of the human body. Indoor exposure patterns as input to the PBPK model are a more realistic situation associated with indoor radon pollution generated from a three-compartment model describing volatilization of radon from domestic water into household air. Combining the two models for inhaled radon in indoor air can be used to estimate a quantitative human exposure through the inhalation of indoor radon for adults based on two sets of exposure scenarios. The results obtained from the present study would help increase the quantitative understanding of risk assessment issues associated with the indoor radon released from groundwater.