• Journal of the Korea institute for structural maintenance and inspection
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• v.11 no.6
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• pp.121-130
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• 2007

In this paper, large scale experimental model tests were performed to investigate the distribution of earth pressure acting on embedded rigid pipes having different bedding conditions. For these tests, very light weighted EPS blocks were installed at top and bottom of the rigid pipe and Jumunjin Standard Sand was used as a ground material. As results of model tests, for the case of no bedding on the pipe, the measured pressure at the bottom of the pipe was $4.96_{tf/m^2}$ whereas they were in the range of $1.87{\sim}4.96_{tf/m^2}$ in the case of EPS beddings being installed at the top and the bottom of the pipe. Therefore, for the case of EPS bedding being installed, the ratio of reduced pressures acting on the pipe, compared with the case of no EPS beddings, were in the rage of 16~62%. As a result of parametric test with changing the locations of EPS bedding, the trend of reducing the stress acting on the pipe was in the order of bottom bedding, top bedding, and top and bottom bedding. Effect of bedding positions on the reduced magnitude of acting pressure on the pipe was more significant in the case of top bedding than in the case of the bottom bedding.

• Journal of Bio-Environment Control
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• v.8 no.4
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• pp.275-280
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• 1999

This study was conducted to investigate the effects of $CO_2$ concentration(310 or 950$\mu$ mol.mol$^{-1}$ ) and air current speed(0.3, 0.5, 0.7 or 0.9m.s$^{-1}$ ) on the growth and development of eggp1ant Plug seedlings (Solanum melongena L.) under artificial 1ighting. For the treatment of $CO_2$ enrichment, stem length and diameter, the ratio of stem length to stem diameter, plant height, leaf area, net photosynthetic rate, top dried weight were significantly different at 1% level. Stem length of plug seedlings decreased at the condition under enriched $CO_2$ and high air current speed above plug stand. Stem diameter of plug seedlings increased and plant height decreased with the increasing $CO_2$ concentration. Plug seedlings had maximum net photosynthetic rate at the air current speed of 0.7m.s$^{-1}$ . Net photosynthetic rate at $CO_2$ concentration of 950$\mu$mol.mol$^{-1}$ increased by 46% than those at 310$\mu$mol.mol$^{-1}$ . Thus $CO_2$ enrichment would be effective for the production of plug seedlings with high quality.

• Applied Microscopy
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• v.42 no.1
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• pp.17-26
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• 2012

Histologic and microstructural changes during the postembryonic development of the wolf spider Arctosa kwangreungensis were studied using light and scanning electron microscopy to examine the relationship between a morphological differentiation and behavioral properties. The postembryo with abdominal yolk sac was stayed inactive in the egg case because its muscular and visual systems were not fully developed to a functional level. The first instar spiderlings, developed from the postembryo by a first molting process, started to exhibit its pigmentation on their body cuticles. In particular, undifferentiated cell clusters of central nervous system (CNS) were densely distributed within the cephalothorax, and highly differentiated abdominal ganglion was observed. They had a characteristic visual system looks more like its adult counterpart, and had segmented appendages looks more like the tiny spiders containing well oriented muscular system. After 3rd instar, spiderlings grew more rapidly with accordance to their consistent growth and periodical molting processes. Thus, the relative area of CNS with respect to cephalothorax was gradually decreased, instead a pair of venom glands, musculature, and connectives occupied the residual area. It has been revealed that the early development of spider can be controled by the feeding condition of larval period, since histologic and microstructural differentiations in both appendages and optic system were completed at the second instar. In particular, behavioral properties of the wandering spiders that depend on vision and their running ability were deeply related to physiological differentiation of the microstructural development.

• Journal of Internet Computing and Services
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• v.15 no.5
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• pp.83-93
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• 2014

Providing personalized services customized to users' needs and preferences becomes highlighted as a key area of user-context computing. It is essential for context-aware technology to be developed more intelligent and meaningful services by being widely applied to a variety of sectors and domains. SDO (Standard Development Organization) such as MPEG and W3C has been actively developed to be standardized services and to improve context-awareness services. Yet current standards related to context-aware technology, such as MPEG-7, MPEG-21, MPEG-V, and emotionML, are not capable enough to support various systems and diverse services. Against this backdrop, the MPEG User Description, referred to also as MPEG-UD Standard, is to ensure interoperability among recommendation services, which take into account user's context when generating recommendations to users. In this light, we introduce standards related to the user context and propose the structure for RD-Engine and the Remote Responsive User Interface(RRUI) system in reference to MPEG-UD. This system collects unit resources matching specific condition according to the user's contexts described by MPEG-UD. In so doing, it improves adaptive user interface considering device features in real-time. By automatically generating adaptive user interfaces tailored to an individual's contexts, the proposed system aims to achieve high-quality user experience for a complex service.

• Applied Chemistry for Engineering
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• v.7 no.3
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• pp.588-596
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• 1996

The optimum conditions of the 1st and 2nd distillation had been investigated to obtaine a high quality monomeric MDI and fire reactive polymeric MDI by purification of crude MDI. Effect of additives on the monomeric MDI's color change, dimerization and the reactivity of polymeric MDI with standard polyol system has been tested. When the monomeric MDI yield is approximately 32%, 4,4'-MDI content is above 98% in the monomeric MDI at the 1st distillation. When the separation ratio of initial portion and residue percentage, reflux ratio are set at respectively, approximately 20wt%, 9wt%, above 2 in order to minimize the content of 2,4'-MDI in monomeric MDI, the freezing point of final distilled monomeric MDI is above $38.4^{\circ}C$. Since the monomeric MDI is inherently unstable in the room condition, monomeric MDI easily changes it's color and conducts self-polymerization reaction. To increase the stability of monomeric MDI, the composition of antioxidant, which is composed of phenolic 1st antioxidant, phosphorus 2nd antioxidant, UV absorbent and Hindered amine light stabilizer are used, and benzoyl chloride as antipolymerization agent test are that APHA color is less than 20, dimer content is remained less than 0.36wt% after 45 days storage of monomeric MDI.

• Applied Chemistry for Engineering
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• v.27 no.5
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• pp.495-501
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• 2016

Mineral oil has been widely used as an insulating oil for electrical transformers for a long time, but the necessity of employing new insulation oil such as vegetable oil has been increased due to urgent needs for the biodegradability when it leaks and also for the thermal stability at a higher operation temperature. Although specific periods are required between the production and consumption, there are still short of the data to prove the insulation oils' storage stability depending upon various circumstances and their resources. Thus, this paper demonstrates the insulation oils' oxidation characteristics of both mineral and vegetable oils when each was exposed to different environments for 12 weeks. From this test, some properties including total acid number, water content and dielectric breakdown were changed under specific conditions and resources. Vegetable oils showed higher hydrophilicity and water saturation than those of mineral oils due to their molecular compositions. Under sunlight exposure condition, all insulation oils oxidized and changed their properties when exposing to the direct light, regardless of the resource used.

• Korean Journal of Ecology and Environment
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• v.39 no.2 s.116
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• pp.236-244
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• 2006

Water quality fluctuation of Gyeongan water area in Paldang reservoir, which measured from the downstream sampling point of Gyeongan stream (G1) to dam sampling point (P), was examined in the light of seasonal rainfall and regional difference in the year of 2002. Annual COD, T-P and T-N concentration dropped conspicuously at the point P (in front of dam) although concentration of Gl point was high. Concentration variation of COD, T-P and T-N from Gl to P point in Gyeongan area was small in August and September. And at G l point showed relatively low concentration. Chlorophyll-a concentration varies less during the autumn season (October to December) than spring season (March to June). Water temperature of Bughangang (north Han-river) area was relatively lower in August and higher in November compared with that of other areas. COD and SS concentration showed big regional difference except in November when the concentrations of which were relatively low. The high Chlorophyll-a concentration of April fell conspicuously in rainy season. Gyeongan area, where the water depth is relatively shallow, indicated steep temperature gradient in April compared with that in August or November. High 55 concentration in April at P point characterized surface layer while the opposite was recorded in August. Mixing of upper and lower layers had taken place causing dilution of COD, T-N and T-P concentration in August. This condition was maintained throughout November. Therefore, spring-summer seasons needed more attention for water management countermeasure than summer-autumn seasons.

• Journal of the korean academy of Pediatric Dentistry
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• v.34 no.1
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• pp.73-80
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• 2007

Compomer that release fluoride could be used on proximal caries of child effectively. But oral cavity is always wet, so saliva inhibits bonding of tooth and compomer. When the saliva exist on bonding, it can be occured microleakages. The purpose of this study was to evaluate the influence of salivary contamination on compomer restoration and degree of microleakage according to restoration methods. Dyract $AP^{(R)}$ and prime and $bond^{(R)}$ NT was applied by the manufacture s instructions. Elipar Trilight was applied for light curing. Saliva pool was made for reconstruction of oral cavity. Two premolar was embedded in acrylic resin. After class II cavity preperation, Dyract $AP^{(R)}$ was restored under several condition, the specimen was thermocycled 500 times with 30 second dwell time. 0.5% methylene blue was used for microleakage test. Micoleakage was measured by the ratio of the infiltration length to occlusal and gingival side interface. Data were analyzed statistically using Kruskal Wallis Test, Mann-Whitney Test. The Result were as follows ; 1. In occlusal side, there were no statistical differences. 2. In gingival side, there were no statistical differences in Group III ($ContactMatrix^{TM}$, Rubber dam, $Oraseal^{(R)}$), Group IV (No saliva contamination). 3. In gingival side, there were no statistical differences in Group I$(ContactMatrix^{TM})$, II($ContactMatrix^{TM}$, Rubber dam). 4. In gingival side, there were statistical differences in Group I$(ContactMatrix^{TM})$, II($ContactMatrix^{TM}$, Rubber dam).

• Journal of Aquaculture
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• v.10 no.2
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• pp.219-225
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• 1997

The growth and size variation of rotifer (Brachionus plicatils) were examined at the various water temepratures ranging form 18 to $36^{\circ}C$, and under continuous light condition. Either Chlorella ellipsoidea or $\omega$-yeast were fed to rotifer as a food organism. Compared to large-type rotifer fed of $\omega$-yeast, those fed on C. ellipsoildea generally showed higher growth at 7th after starting culture under the water temperaure of less than $30^{\circ}C$. Above such temperature, the large-type rotifer fed on $\omega$-yeast showed higher growth rather than those fed on C. ellipsoidea and the maximum cell number reached 1,420 ind./m$\ell$ at $36^{\circ}C$, whereas when the small-type rotifer was fed on $\omega$-teast, its maximum cell number was to be 1,669 ind./m$\ell$at $34^{\circ}C$. The striking decrease in size was found in large-type rotifer which was to be $112.1\mu m$m(initial : 202.0${\mu}{\textrm}{m}$) when they were fed on C. ellipsoidea at $34^{\circ}C$ for 5 days after starting culture. A great increase in size from the initial of 157.0 to $201.3\mu m$mwas show in small-type rotifer fed on $\omega$-yeast at $20^{\circ}C$,for 5 days. The present results demonstrated that size variation of rotifer could be controlled by changing culture temperature.

• Korean Journal of Veterinary Research
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• v.31 no.3
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• pp.241-251
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• 1991

In order to investigate the effect of Panax ginseng extract and it's degree in mucociliary change of mice nasal septum epithelia exposured to sulfur dioxide, 96 ICR male mice were used. They were at first divided the 4th week, the 8th week or the 16th week groups according to the age after birth and 6 hour or 12 hour groups according to the $SO_2$ gas exposured hour in a day, and at control, 50mg, 100mg and 200mg injection groups according to the dosage of the freeze-drying powder of the ginseng extract which was injected into the mouse peritoneal cavities in the condition of the solution solved with physiological saline solution. Each subgroups which were divided finaly included 4 male mice. The histological tissue sections for observation were made from nasal septum, posterior nasal orfice and trachea. The results obtained by experiments were summarized as followings. 1. The loss of the nasal mucosa epithelial cilia of the mouse exponsure to the $SO_2$ gas after ginseng extract injection was apparently diminish eompare to those exposured only $SO_2$ gas without pretreatment of ginseng extract (p<0.01). 2. The inhibition effect for the loss of nasal mucocilia according to the ginseng extract dosages not found in this research (p>0.05). 3. There were differences in the loss of nasal mucosa cilia according to the $SO_2$ gas exposure time between the control group and ginseng extract pretreatment group (p<0.01). 4. According to the increase of the postnatal time, there were remarkable differences between the control group and the ginseng extract pretreatment groups in the loss of nasal mucosa cilia (p<0.01). 5. Ciliary changes of the posterior nasal orifice and trachea according to the $SO_2$ gas exposure time, mice age and ginseng dosages, were not dearly observed in this light microscopical observation.