• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2002년도 가을 학술발표회 논문집
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• pp.495-500
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• 2002

The purpose of this study is to develop and to apply this permanent cement mortar form as one of those system forms to improve existing form's problems. (1) In the fire proof test with combined specimen, the fire proof covering including form section thickness is satisfied with the fire proof criterion. It is considered that form section thickness has no problem (2) The suitable method of normal pressure steam curing for the form's mass production is 4 hours in 65℃ considering production cost, the silica fume admixture is economic.

• 산업경영시스템학회지
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• 제18권36호
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• pp.61-69
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• 1995

The diagnosis has an very important role in curing dementia. But there was not the effective method to diagnose it until now. In this paper we analyzed the EEG in Alzheimer's disease and normal control groups to differentiated them by nonlinear parameter such as the correlation dimension. And we propose the nonlinear analysis of EEG in Alzheimer's disease as a useful tool of early diagnosis of it.

• 한국농공학회지
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• 제41권6호
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• pp.75-81
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• 1999

This study is performed to evaluate theproperties of concrete using industrial wastes such as fly ash, zeolite powder and blast furnace slag powder. Seven types of concrete mixtures are made in this study. Water0reducing admixture and air entaining agent are used for all mixtures. Test results, the hydration evolution amounts are decreased by 2 ∼31 % than that of the normal portland cement and air contents of concrete are decreased by 1 ∼15% and compressive strengths are increased by 2∼10% at the curing age 28 days than that of the normal portland cement concrete. Accordingly, concrete using industrial wastes will greatly improve the properties of concrete.

• 한국식품영양과학회지
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• 제28권1호
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• pp.167-171
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• 1999

The production of emulsion sausage generally contain nitrite as a curing agent for preservative effect and color as well as flavor development. This investigation describe a study on the inhibitory effect of chitosan against some spoilage bacteria and substitution effect of nitrite in sausages. Among of the chitosan, M.W. 120KDa of chitosan has shown an antimicrobial effect. When 0.2% of chitosan and half of normal nitrite content were added to sausage, effect of preservative quality was same that added to normal content of nitrite in sausages. Sausage added to 0.5% of chitosan has been a good storage property even though without nitrite. The growth of most of bacteria was inhibited 80% or more at 0.01~0.2% of chitosan. These results indicated that M.W. 120KDa of chitosan as a natural material could provide sausage protection and very reduced or substituted amount of nitrite against spoilage bacteria.

• 대한인간공학회:학술대회논문집
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• 대한인간공학회 1996년도 춘계학술대회논문집
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• pp.160-167
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• 1996

The early diagnosis has an very important role in curing dementia. But there was not an effective method to diagnose it until now. In this paper we analyzed the EEG in Alzheimer's disease and normal control groups to compare by nonlinear parameter such as the largest Lyapunov exponent $L_{1}$. We found that patients with Alzheimer's disease have significantly lower$L_{1}$ than normal groups. And we propose the nonlinear analysis of EEG as a useful tool for the early diagnosis of Alzheimer's disease.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2004년도 추계 학술발표회 제16권2호
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• pp.281-284
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• 2004

The most important reason of using of ultra high strength concrete in super tall building is that ultra high strength concrete can reduce the section of members and control side sway effectively. However, the practical utilization of ultra high strength concrete is dependent not only on the production techniques, but also the overall preparation including proper code provisions, construction technique. The purpose of this study is to evaluate of mechanical properties of UHSC, such as modulus of elasticity, stress-strain behavior, modulus of rupture and tensile splitting strength. It is similar to normal or high strength concrete but necessary to discern the difference between normal or high strength concrete and ultra high strength concrete and modify existed equations. And in this study another important factor is to discern the difference according to member size, curing method in ultra high strength concrete experimentally.

• 산업경영시스템학회지
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• 제19권39호
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• pp.129-142
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• 1996

The early diagnosis has an very important role in curing dementia. But there was not the effective method to diagnose it until now. In this paper we analyzed the EEG of Alzheimer's disease patients and normal groups by nonlinear methods. In the analysis we calculated the correlation dimensions $D_2$ and the largest Lyapunov exponent $L_1$. We found that patients with Alzheimer's disease have significantly lower $D_2$ and TEX>$L_1$ than normal groups. It means that brains injured by Alzheimer's disease have electrophysiological inactive elements and have decreased chaotic behaviour. We propose the nonlinear analysis of the EEG as a useful tool for the early diagnosis of Alzheimer's disease.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2021년도 가을 학술논문 발표대회
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• pp.125-126
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• 2021

In order to improve the housing culture, construction changes for the utilization of diverse and multifunctional spaces are appearing in response to the increasing diverse needs of consumers. Cellular Light-weight Concrete (CLC) is being developed for use in fire-resistant heat-insulating walls and non-bearing walls. However, manufacturing non-uniformity has become a problem as a drawback due to the use of foamed bubbles and normal temperature curing, and additional research is required. Therefore, in order to suppress cracks due to drying shrinkage, silica sand is mixed with CLC to try to understand its characteristics. In the experiment, the compressive strength from 7 to 28 days of age was measured via a constant temperature and humidity chamber, and the drying shrinkage was analyzed according to each condition using a strain gauge. The compressive strength of matrix tends to decrease as the substitution rate of silica sand increases. This is judged by the result derived from the fact that the specific surface area of silica sand is smaller than that of slag. Based on KS F 2701 (ALC block), the compressive strength of 0.6 products is 4.9 MPa or more as a guide, so the maximum replacement rate of silica sand that satisfies this can be seen at 60%. Looking at the change in drying shrinkage for just 7 days, the shrinkage due to temperature change and drying is 0.7 mm, and the possibility of cracking due to shrinkage can be seen, and it seems that continuous improvement and supplementation are needed in the future.

• 한국농공학회지
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• 제24권2호
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• pp.67-75
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• 1982

A study on the effect of water reducing agent on the various characteristics of concrete has been conducted. The experimental results of the study are summarized as follows. 1. Slump test for the concrete added water reducing setretarding agent in proper quantity have been conducted. According to the test results, the decreasing rate of slump value become bigger than plain concrete with increase of the unit weight of cement and elapse of time 2. In case the proper quantity content of maximum compressive strength in Fig. 5 of water reducing set retarding agent is added, unit weight of water is decreased about 15% or so as compared with plain concrete. with the increase of water reducing set accelerating agent content unit weight of water is decreased much more, And other hand, amount of air entraining shows the increasing tendency with the increase of water reducing agent content. 3. The adding rate of water reducing agent which produce maximum strength shows that WR-CH and WR-SA which is water reducing set-starding agent is 0.2% and WR-CO is 0.5% and that WS-PO which is water reducing set accelerating agent is 0.5 4. compressive strength jof the concrete made of sulfate resistant cement shows less than the strength of normal portland cement at initial strength but the strength of both cement shows almost same at curing age of 28 days. 5. when proper quantity of water reducing set retarding agent is used, boned strength is increased about 15% at curing age of 28days. 6. According to the result of durability test, dynamic young's mudulus of elasticity at plain concrete is decreased about 50% as compared with initial step at 300 cycle of freezing and thawing after curing age of days. on the contarary the concrete used water reducing agent is decreased less than 7%.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2008년도 추계 학술논문 발표대회
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• pp.37-41
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• 2008

According to the recent rapidly increasing that construction works are gradually Manhattanized mainly the grand scaled residential buildings, the foundation of the building that is related to safety is increasing for building as a grand scaled mat concrete. Because mat concrete can not be simultaneously placing of concrete in a great quantity due to the circumstance at the field, the inequal deformation of the tensile stress that according to the time lag of hydration heat between the upper layer and the lower layer is affecting as a cause that is the possibility of crack occurrence by increasing. Accordingly, this research checked the efficiency of super retard concrete in applying real structures, and we implemented the preparatory experiment to settle up the inequal deformation of the tensile stress substantially that is according to the time lag of placement between the upper layer and the lower layer by controlling the setting time using the super retarding agent. As the result of test, the more target of delay time lengthened, the more fluidity increased and air content indicated a little differences. There was from 2 to 10 hours between the standard curing and the outside curing at the setting time and in case of calculating the rate of mixing at real structure is required that mix promotion, increasing the amount of mixing, by setting up the curing temperature. The super retard concrete showed the result that in compressive strength, early-age strength was smaller than normal concrete whereas it was same or more figures from at the aging 28days because of the super retarding agent.