• Journal of The Korean Society of Grassland and Forage Science
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• v.37 no.2
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• pp.140-144
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• 2017

This study was conducted to investigate the effect of microbial inoculation as additive consisting of novel lactic acid bacteria on quality and fermentation characterization of Miscanthus sinnensis silages. The contents of crude protein, acid detergent fiber, neutral detergent fiber in treatments of additive of lactic acid bacteria (ALAB) inoculation had similar to control. pH of Miscanthus sinnensis (MS) silage in treatments of ALAB inoculation significantly decreased as compared to control (p<0.05). The content of lactic acid in in treatments of ALAB inoculation significantly increased (p<0.05), but the content of acetic acid in treatments of ALAB inoculation decreased. In addition, number of lactic acid bacteria in treatments of ALAB inoculation significantly increased as compared to control (p<0.05). Therefor, we suggest that MS silage improved by inoculation of additive consisting of novel lactic acid bacteria.

• Journal of The Korean Society of Grassland and Forage Science
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• v.37 no.4
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• pp.332-336
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• 2017

This study was conducted to investigate the effect of addition of lactic acid bacteria inoculants on quality of rye silage harvested at early heading stage. The nutritive values in lactic acid bacteria (LAB) inoculated group showed similar results to control. The pH of rye silage in LAB inoculation significantly decreased as compared to control (p<0.05). In addition, the content of lactic acid in LAB inoculation significantly increased (p<0.05), but the content of acetic acid in LAB treatments decreased. In addition, lactic acid bacterial counts in LAB inoculation significantly increased as compared to control (p<0.05). Therefore, we suggest that rye silage could be improved by LAB inoculation.

• Journal of The Korean Society of Grassland and Forage Science
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• v.40 no.1
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• pp.1-6
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• 2020

This study was conducted to evaluate feed value of imported hays and examine current situation of species and hay grade. To evaluate the quality of the imported hay, 133 pieces including 9 species of roughage types were collected at the national hay importers, the TMR companies and livestock farms from 2016 to 2018. The quality grades of imported hay were 3~4 and most imported hay were considered to had low. The ADF, Ash, TDN and DDM in feed composition of alfalfa by quality grades presented significant differences(p<0.05). The quality grade on alfalfa was not similar to the actual quality grades calculated through feed composition. The feed composition of grasses by quality degrees presented significant differences in all contents except DM and CP (p<0.05). As the distributed grasses of the unmarked quality grade was low quality and accounted for 49%, it is urgent to present quality standards based on feed composition. As these results, the grades of imported hays were lower than the marked quality grades. Therefore, the imported roughage's(hay) price that considered to only quality grades on the marked imported roughages(hay) package can cause a loss to the livestock farms as economic damage. An institutional arrangement should be established to review the quality grades of imported hay.

• Journal of Elementary Mathematics Education in Korea
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• v.14 no.3
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• pp.789-806
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• 2010

As calls for more attention toward social minority group increases in our society recently, in the field of mathematics education more attention toward an issue about mathematics underachievers is being amplified. Thus, the present study is to examine the effects of teaching method considering students' cognitive characteristics on mathematical underachievers' problem solving and mathematical disposition. For this study, 10 fifth graders identified as mathematical underachievers based on the results of the national level diagnosis assessment and school based assessment were voluntarily selected from an elementary school in Seoul. The results of this study found out the fact that students participating in this program improved in terms of an ability both to solve problems in various ways and to explain an process of problem solving using spoken or written language and drawings. In addition, learning environment respecting students' own mathematical ideas seems to positively influence students' attitudes toward mathematics learning and mathematical dispositions. Furthermore, this study pointed out that mathematical underachievers tend to have difficulty in expressing their own mathematical thinking by reason of linguistic limitation. Finally, the findings of this study imply that for effective teaching of mathematics underachievers, these students' own informal experience and knowledge about mathematics as well as their characteristics regarding learning difficulties should be strongly considered.

• The Journal of the Korea Contents Association
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• v.12 no.2
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• pp.331-338
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• 2012

The purpose of this study is to investigate the cardiopulmonary function and the energy metabolism of stroke patients and normal persons of graded load exercise using lower ergometer. Targeting 11 normal persons(male: 6, female: 5) and 9 stroke patients (male: 4, female: 5), an graded load exercise was performed with the use of lower ergometer by increasing 25 watts every 6 minute and Quark $b_2$ were used for the cardiopulmonary function and the energy metabolism. With respect to normal persons, there were significant increases in the phase of graded load exercise, maximum oxygen uptake time, exercise time with respect to the cardiopulmonary function. In addition, there was a significant correlation between cardiopulmonary function and energy metabolism, but there was no significant difference energy metabolism. As a result, there were no significant differences between stroke patients and normal persons of the cardiopulmonary function and the energy metabolism within 18 minutes, but it had significant differences between maximum oxygen uptake and exercise time. Moreover, it was possible to identify that the cardiopulmonary function and the energy metabolism of stroke patients and normal persons are related with maximum oxygen uptake.

• Korean Journal of Construction Engineering and Management
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• v.8 no.6
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• pp.150-158
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• 2007

As the amount of $CO_2$ emission in Korea is ranked 9th and the increasing rate of $CO_2$ emissions highest in the world, it is strongly necessary to devise methods to decrease the amount of $CO_2$ in each industry as the basis of establishing environmentally sustainable production system. This paper aims to identify the characteristics of $CO_2$ emissions from construction wastes throughout the simplified LCA (Life Cycle Assessment) and suggest the strategic guideline for the construction waste management plan to decrease $CO_2$. As a result of LCA on the case of a high-rise residential building project, total sum of $CO_2$ emission generated from construction wastes appeared as 6,818,123kg-$CO_2$ and $CO_2$ emission per unit floor area as 21.01kg-$CO_2/{\beta}{\ge}$. The principal waste materials generating more than 95% of $CO_2$ are materials such as reinforcing bar, temporary materials, cement, ready-mixed-concrete, concrete products, and tile, which have relatively high unit emission rate of $CO_2$ in the process of production. Besides, more than 92% of $CO_2$ was generated from the activities such as structure work, plaster work, temporary work, and tile and stone work, which are generally executed in the early phase of the whole construction period. Reflecting these results, the guideline for the construction waste management plan was recommended. If the waste management plan is established considering the guideline suggested, there would be high potential to decrease the amount of $CO_2$ generated from construction wastes.

• The Journal of Korean Academy of Prosthodontics
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• v.43 no.1
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• pp.52-60
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• 2005

Purpose. The intent of this study was to evaluate the effects of curing conditions on self-curing denture base resins to find out proper condition in self-curing resin polymerization. Materials and methods, In this study, 3 commercial self-curing denture base resins are used Vertex SC, Tokuso Rebase and Jet Denture Repair Acrylic. After mixing the self curing resin, it was placed in a stainless steel mold(3$\times$6$\times$60mm). The mold containing the resin was placed under the following conditions: in air at 23$^{\circ}C$; or in water at 23$^{\circ}C$; or in water at 23$^{\circ}C$ under pressure(20psi); or in water at 37$^{\circ}C$ under pressure(20psi) or in water at 50$^{\circ}C$ under pressure(20psi) , or in water at 65$^{\circ}C$ under pressure(20psi), respectively. Also heat-curing denture base resin is polymerized according to manufactures' instructions as control. Fracture toughness was measured by a single edge notched beam(SENB) method. Notch about 3mm deep was carved at the center of the long axis of the specimen using a dental diamond disk driven by a dental micro engine. The flexural test was carried out at a crosshead speed 0.5mm/min and fracture surface were observed under measuring microscope. Results and conclusion . The results obtained were summarized as follows : 1. The fracture toughness value of self-curing denture base resins were relatively lower than that of heat-curing denture base resin. 2. In Vertex SC and Jet Denture Repair Acrylic, higher fracture toughness value was observed in the curing environment with pressure but in Tokuso Rebase, low fracture toughness value was observed but there was no statistical difference. 3. Higher fracture toughness value was observed in the curing environment with water than air but there was no statistical difference. 4. Raising the temperature in water showed the increase of fracture toughness.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.15 no.2
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• pp.152-158
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• 2004

A low phase noise frequency synthesizer at X-Band which employs the subharmonic injection locking was designed and tested. The designed frequency synthesizer consists of a 1.75 GHz master oscillator - which also operates as a harmonic generator - and a 10.5 GHz slave oscillator. A 1.75 GHz master oscillator based on PLL technique used two transistors - one constitutes the active part of VCO and the other operates as a buffer amplifier as well as harmonic generator. The first stage operates a fixed locked oscillator and using the BJT transistor whose cutoff frequency is 45 GHz, the second stage is designed, operating as a harmonic generator. The 6th harmonic which is produced from the harmonic generator is injected into the following slave oscillator which also behaves as an amplifier having about 45 dB gain. The realized frequency synthesizer has a 7.4 V/49 mA, -0.5 V/4 mA of the low DC power consumption, 4.53 dBm of output power, and a phase noise of -95.09 dBc/Hz and -108.90 dBc/Hz at the 10 kHz and 100 kHz offset frequency, respectively.

• Journal of dental hygiene science
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• v.17 no.6
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• pp.481-486
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• 2017

The study aimed to compare the whitening efficacy of a strip and gel containing 2.9% hydrogen peroxide, using a tooth whitening light activator. The whitening effect was compared through in vitro and in vivo studies. In the in vitro study, we used stained hydroxyapatite (HAP) specimens as artificial teeth. HAP specimens were made using HAP powder and polyvinyl alcohol solution, and stained by modified Stookey's method. A whitening gel and whitening strip were applied to the respective specimens for 20 minutes, with a light activator. The color changes were measured using a colorimeter. In the in vivo study, one group (test 1) used the gel with a light activator and the other group (test 2) used a strip with the same activator for 15 minutes a day, for four consecutive days. An organoleptic evaluation using a Vita shade guide and instrumental evaluation using a Shade eye-NCC (Shofu Co., Japan) were performed. The color change values (${\Delta}E^*$) in the in vitro study revealed the strip with the light activator to be more effective than the gel with the same activator (p<0.001). In the in vivo study, even though there was no significant difference between the groups with respect to the ${\Delta}E^*$, using either the Shade eye-NCC or the Vita shade guide, the change in yellowness (${\Delta}b^*$) was statistically significant (p=0.024). In conclusion, test 2 group that used 2.9% hydrogen peroxide strip with a light activator, showed a tendency towards increased whitening than test 1 group that used the gel with the same activator; however further studies are needed to validate the above finding.

• Journal of dental hygiene science
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• v.15 no.6
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• pp.794-799
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• 2015

In recent years, there has been a global trend toward the importance of natural extracts for the prevention and treatment of human diseases. ${\beta}$-glucan is known to have anti-inflammatory activity, anti-cancer, and improvement of immune system. Polycan is purified ${\beta}$-glucan from Aureobasidum pullulans SM-2001. The anti-cancer effects of ${\beta}$-gluconsan calcium, polycan and calcium gluconate complex, were evaluated in human oral cancer YD-10B cells. YD-10B cells were cultured in the presence of 0, 0.5, 0.75, 1 mg/ml ${\beta}$-gluconsan calcium for 48 hours. MTT assay, cell counting, and observation of cell morphology were conducted. The number of cells decreased and cell morphology changed in the 0.5 mg/ml of ${\beta}$-gluconsan calcium. Almost all cells were dead in the 0.75 and 1 mg/ml. MTT assay showed a dose-dependent reduction in cell proliferation (p<0.05). These results indicate that ${\beta}$-gluconsan calcium exhibiting anti-cancer effects in YD-10B cells through changes in cell morphology and cell death.