• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.7 no.2
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• pp.207-216
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• 1995

Flow and heat transfer characteristics of mixed convection heat transfer in a rectangular en-closure with various outlets are numerically investigated. The parameters considered here include Reynolds number, Grashof number and the position of outlet. The results show streamlines, isotherms, Nusselt numbers, velocity and temperature distributions. It has been shown that as Reynolds number increases, the size of cell decreases at Re$\leq$100 and increases at Re>100 for $Gr=10^4$. There is a minimum size of cells at Re=100, $Gr=10^4$. The maximum mean Nusselt number occurs at Re=400, $Gr=10^4$ and one right outlet. The mean Nusselt numbers can be formulated by the correlation equation $Nu=C{\cdot}Gr^a{\cdot}Re^b$.

• International Commerce and Information Review
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• v.3 no.2
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• pp.261-280
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• 2001

From the IMF(International Monetary fund) crisis, the management conditions of the trading company which run business in world market, has rapidly changed. In particular, the trading conglomerate's competitive power have declined. This study, addressing such changes, intend to analyze what factors are that have generated this changes in trading conglomerate's environment. The study specifically takes it into account that the differences between Korea trading company and Japan's. This research was confirmed by data and field survey in two country. The results of research are summarized as follow. The Korean trading company are inferior to the Japanese trading company in total volume(Korea: 24.1, Japan 100), the benefit volume(Korea: 8.7, Japan 100), the stability of turnover(Korea: 36.6, Japan 100), the network power in foreign country(Korea: 19.2, Japan 100), the power of e-business(Korea: 17.0, Japan 100). But the debt ratio of Korea company is significantly lower than that of Japan's(Korea: 160.4%, Japan 940.5%). In conclusion, providing that the Korean trading company want to be a world-class champion in trading field, they have to introduce the new management strategies which means the high-profit base trading, the long term investment and the internet business.

• Korean Journal of Materials Research
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• v.7 no.6
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• pp.522-528
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• 1997

RF-magnetron Sputtering Process를 이용하여 Pt/Ti/Si(100)기판위에 lanthanum-modified lead titanate 박막을 제작하였다. 기판온도와 증착시간이 증가함에 따라 증착율은 감소하였다. 기판온도가 증가함에 따라 fine grain들은 large grain으로 변화하였다. Perovskite구조는 기판온도 54$0^{\circ}C$, gas pressure 30mtorr에서 나타나기 시작하였다. 본 실험에서 perovskite 박막제작에 대한 조건은 기판온도 58$0^{\circ}C$, gas pressure 30mtorr였다. Pt/Ti/Si(100) 우선 배향된 박막을 얻었다. La양이 증가함에 따라 유전율, 항전계, 잔류분극량은 증가하였다. 중심주파수가 44.7MHz, 전파속도는 2680m/sec를 가지는 SAW filter 특성을 얻었다.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2019.04a
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• pp.52-52
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• 2019

Buckwheat is well-known crop for containing a high contents of flavonoids that are effective in vascular disease. The current study was performed to estimate the influence of morphological characterization of Fagopyrum esculentum (ES) germplasm for seed's two major flavonoids contents: rutin and quercetin. We found that the red stem color, pale green leaf color, arrowhead leaf shape, white flower color, pale brown seed coat color, and egg-shaped seed were significantly associated with 77%, 56.7%, 83.7%, 98.7%, 70.8% and 74.5% germplasm, respectively. Overall, the rutin contents of ES germplasm ranged from 0.30 to 47.86 mg/100g dry weight (DW) and the quercetin contents ranged from 0 to 1.22 mg/100g DW. The rutin contents of germplasm possessing red stem color, pale green leaf color, arrowhead leaves, white flower color, pale brown seed coat color and egg-shaped seed ranged from 7.22 to 47.86 mg/100g DW. However, the quercetin contents of germplasm with red stem color and pale brown seed coat color ranged from 0 to 1.15 mg/100g DW, with pale green leaves ranged from 0 to 0.96 mg/100g, with arrowhead leaves and white flower ranged from 0 to 1.22 mg/100g and with egg-shaped seed ranged from 0.32 to 1.22 mg/100g DW. In PCA analysis, the first three principal components (PCs) showed Eigen value more than 1 and accounted for 51.70% of variation. For both higher contents of rutin and quercetin, the morphological evaluation in ES shows a tendency of red stem color, arrowhead leaves, pale green leaf color, white flower color, pale brown seed coat color and egg-shaped seed. From this information, we can assume the rutin and quercetin contents by the morphological characteristics of the germplasm. And It could be useful in improving the rutin and quercetin contents and selecting proper resources for cultivation in existing buckwheat cultivars.

• The Korean Journal of Food And Nutrition
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• v.14 no.2
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• pp.161-166
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• 2001

The optimum condition for production of yeast extract by autolysis and enzymatic method were studied with waste brewers\` yeast. The major components of brewer\`s yeast in proximate compositions were carbohydrate(46.0%) and protein(41.7%). There was a little appreciable difference in the promaximate composition of waste brewers\` and bakery yeast. The major minerals were identified as K, P, Mg and Ca, and their contents were about 1,659.7%, 1,197.4mg%, 210.4mg% and 105.6mg%, respectively. The major vitamins were identified as vitamin C and vitamin B group, and their contents were about 7.9IU/100g and 4.2IU/100g, respectively. The optimum yeast concentration in the reaction suspension was 10% (w/v) waste brewer\`s yeast slurry. The protein content in brewer\`s yeast extract was increased with addition of NaCl as plasmolyzers. However, the plasmolyzer effect of ethanol a little showed as the concentration increasd from 3% ∼7%. The 5\`-nucleotides(5\`-GMP and 5\`-IMP) content in brewer\`s yeast extract was increased with addition of glucanase. The total content of 5\`-nucleotides (5\`-GMP and 5\`-IMP) increased by 160% than those by the autolysis of waste brewer\`s and bakery yeast.

• Journal of the Korean Wood Science and Technology
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• v.1 no.2
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• pp.3-10
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• 1973

This study was carried out to examine the characeristics of waste sanders(S)from. plywood and pre-finishing plywood surface sanding and double saw finishing, as a new extander in urea-formaldehyde resin(UFR) in plywood adhesive, and to focus, adhesive strength using the glue extended with milled sanders(MS) as extender, leveling the optimum amount of MS to be added, and examining the physical properties of glue extended MS & S. Also economical good feasibility of substitution for wheat flour(WF) with MS as a new extender is analyzed and presented in details. Selecting three standard samples of 80, 100 and 180 mesh, sorking them in distilled water at $20^{\circ}C$, 24 hours, redrying at $105^{\circ}C$ and rescreening the sample with standard screen, again, the 3 samples of 80, 100, and 180 mesh are passed 23 percent through 80 mesh sander standard sample 27 percent through on 100 mesh and only 10.9 percent through 180 mesh, respectively. The particle size of retained parts are greater in size of redried form. It seems undoubtly that particles to be extended in glue are got swollen and become greater in size and coarser in shape. The shape of fresh S particles are irregular thin needle with small scale, as shown in Figure 5. PFS are so finer than plywood S that only 9.8 percent of the S retained on 100 mest screen, 24. 30 percent on 100-160 mesh, and 65.9% on 160-180 mesh. But particle size of the fresh S is large enough to make the viscosity of glue direct extended with S too high to apply it glue spreader. The glue extended with milled sanders(MS). 3 hours milled PFS or 6 hours milled plywood S, having particle sizes shown in Tables 7 and 8, as ratio of Reain/MS/WF/water: 100/8/8/10, indicate good viscosity of 16 to 24 ps, as shown in Figure 5, for applying direct to glue spreader, have high tensile-shear strength (adhesive strength), 102.4 kp/$cm^2$, and 94 percent wood failure.

• Journal of the Korea institute for structural maintenance and inspection
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• v.22 no.3
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• pp.31-37
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• 2018

This study evaluates the dynamic tensile behavior of HPFRCC according to compressive strength levels of 100, 140 and 180 MPa. Firstly, the compressive stress-strain relationship of 100, 140 and 180 MPa class HPFRCC was analyzed. As a result, the compressive strengths were 112, 150 and 202 MPa, respectively, and the elastic modulus increased with increasing compressive strength. The static tensile strengths of HPFRCC of 100, 140 and 180 MPa were 10.7, 11.5 and 16.5 MPa, and tensile strength also increased with increasing compressive strength. On the other hand, static tensile strength and energy absorption capacity at 100 and 140 MPa class HPFRCC showed no significant difference according to the compressive strength level. It was influenced by the specification of specimen and the arrangement of steel fiber. As a result of evaluating the dynamic impact tensile strength of HPFRCC, tensile strength and dynamic impact factor of all HPFRCCs tended to increase with increasing strain rate from 10-1/s to 150/s. In the same strain rate range, the DIF of the tensile strength was measured higher as the compressive strength of HPFRCC was lower. It is considered that HPFRCC of 100 MPa is the best in terms of efficiency. Therefore, it is advantageous to use HPFRCC with high compressive strength when a high level of tensile performance is required, and it is preferable to use HPFRCC close to the target compressive strength for more efficient approach at a high strain rate such as explosion.

• Korean Journal of Organic Agriculture
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• v.19 no.spc
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• pp.63-66
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• 2011

An Intergenerational Horticultural Program in a rural community in Korea was tried out to enhance social interaction between elderly citizens and children, to promote the positive self-esteem of the elderly in a rural community, to change the attitude of children towards the elderly, and to create a rural community full of vitality. The clients were 20 elderly (60-80 years old) and 40 preschool children (6-7 years old). The activities in this program included seed of hope, round autumn garden, dish garden, in the vegetable patch, flower decoration for the Chuseok Festival, rainbow flower basket, heart card, fragrance of love, and a kimchi party. The results were a decrease in depression among the elderly from 44.0% to 33.7%. General satisfaction among the elderly was 100%. The desire to rejoin among the elderly was 100%. General satisfaction among the children was 100%. The desire to rejoin among the children was 93.5%.

• Journal of Advanced Marine Engineering and Technology
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• v.24 no.1
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• pp.67-74
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• 2000

Recently, PTFE-polymide composites are being used self-lubricating parts for industrial field. Thus, this study is mainly concerned with friction and wear properties for the piston ring of non-lubricating air compressor which made of PTFE-polymide composites. The friction and wear test was carried out for the different composition ratio under the atomsphere room temperature and constant load of 7.69N and their friction and wear properties were compared with each other at various sliding speed. notable results are summarized as follows. PTFE 100% showed that friction coefficient was almost same values at 0.94 and 1.88m/s but the value was decreased at 2.83m/s because the friction temperature is higher than low speed. PTFE 80%-PI 20% showed the lowest mean friction coefficient at 2.83m/s. PTFE 20-PI 80% showed the highest friction coefficient at 0.94m/s and the value was decreased at high speed but the value is higher than other materials except PTFE 100 %. PI 100% showed the highest friction coefficient at 0.94 and 1.88m/s becuase adhesive wear mainly occurred that speed. PTFE 100% showed highest specific wear rate on the whole. Specific wear rate of PTFE 80%-PI 20% was almost the same value with PTFE 20%-PI80%. PI 100%showed the lowest value at high sliding speed because the friction surface was thicken and carbonated by high friction temperature.

• Journal of Life Science
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• v.30 no.7
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• pp.592-597
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• 2020

Soybean [Glycine max (L.) Merr.] seeds contain an average of 40% protein on a dry weight basis, but they also contain antinutritional elements such as lectin, Kunitz trypsin inhibitor (KTI), and 7S α'- subunit protein. The objective of this research was to develop a new soybean genotype with triple recessive alleles for these elements. Three parents (Gaechuck#2, PI506876, and Le-16) were used to develop the genetic population, and the presence of lectin and KTI protein was detected using Western blot while 7S α' subunit protein was detected using SDS-PAGE. One F₃ plant strain with proper agronomical traits such as type, height, seed quality, and 100-seed weight was selected. The genotype of the developed strain is titilelecgy1cgy1, that is KTI, lectin, and 7S α' subunit protein free. The new strain has a purple flower, determinate growth habit, and light yellow pods at maturity. The seed has a buffer hilum and is yellow in color. The new strain's height was 58 cm compared to the Daewonkong cultivar at 46 cm, and its 100-seed weight was 27.1 g, smaller than the Daewonkong at 29.0 g. This is the first new soybean strain with the titilelecgy1cgy1 genotype, and it can be used to improve yellow soybean cultivars of high quality and function.