• Journal of the Korea Institute of Building Construction
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• v.14 no.5
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• pp.397-405
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• 2014

There are many literatures reporting that the service life of re-bars in concrete structures is reduced in the oceanic environment due to chloride attack. To solve this problem, this study used geo-polymer as a mix material for concrete to increase its resistance to salt damage, and the external voltage method, one of the electric methods, is was applied to evaluate the likelihood of re-bars in the oceanic structure being exposed to the extreme salt environment. The items evaluated include the natural potential of re-bars and the corrosion rate. The results of the tests showed that in all of the salt environmental conditions (submerged zone, tidal zone, and crack), the tested materials were remarkably effective compared with ordinary concrete. The corrosion protective property was found not only in the evaluation of the natural potential but also in the evaluation of the corrosion rate, suggesting that the external voltage method can be used stably for geo-polymer RC structures in an extreme salt environment.

• Polymer(Korea)
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• v.26 no.1
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• pp.128-138
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• 2002

1,3-Bis(2-chloroethyl)-1-nitrosourea (BCNU, Carmustine)-loaded poly(D, L-lactide-co-glycolide) (PLGA, lactide/glycolide mole ratio 75 : 25) microparticles were prepared and fabricated into wafers in an attempt to study the possibility for the treatment of malignant glioma by direct inserting the wafers to the tumor or the cavity remained after surgical resection of the tumor. SEM observation of the microparticles prepared by spray drying method revealed that the microparticles were spherical, i. e. microspheres. Significant reduction of the crystallinity of BCNU encapsulated in PLGA was confirmed by X-ray diffraction and differential scanning calorimetry analyses of the BCNU-loaded PLGA microparticles. Release pattern of BCNU was dependent on several preparation parameters, such as the molecular weight and concentration of PLGA, and initial BCNU loading amount, etc. In vitro release of BCNU was prolonged over 8 weeks with close to zero-order release pattern after initial burst effect. Observations of morphological change of wafers and pH change of release media during release test period confirmed that hydration and degradation of PLGA would be facilitated with an increase of BCNU-loading amount.

• Journal of Energy Engineering
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• v.12 no.2
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• pp.139-144
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• 2003

Augmentation of CHF by ultrasonic vibration in water pool is experimentally investigated under pool boiling condition. The experiments are carried out using copper coated plates and distilled water. Measurements of CHF on flat plate heated surface were made with and without ultrasonic wave and with variations in inclined angle of the surface and water subcooling. Experimental apparatus consists of a bath, power supply, test section, ultrasonic generator, and data acquisition system. The measurements show that ultrasonic wave enhances CHF and its extent is dependent upon inclination angle as well as water subcooling. The rate of increase in CHF increases with an increase in water subcooling while it decreases with an increase in inclination angle. Visual observation shows that the cause of CHF augmentation is closely related with the dynamic behavior of bubble generation and departure in acoustic field.

• Review of KIISC
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• v.20 no.2
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• pp.32-43
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• 2010

클라우드 컴퓨팅 서비스의 많은 장점에도 불구하고 아직 기업들이 서비스의 가용성 및 데이터 보안, 자사 데이터에 대한 통제권 확보, 종속성 등의 문제로 클라우드 컴퓨팅 서비스의 이용을 꺼리고 있다. 이 같은 문제들은 기술개발, 표준화, 표준약관, 서비스수준협약(SLA) 등으로 어느 정도 해결이 가능하다 그러나 데이터가 여러 국가에 복제되어 분산 저장될 경우 데이터의 국외이전 금지 문제, 데이터의 보관 및 파기 의무, IT 컴플라이언스 수탁자의 불법행위에 대한 위탁자의 책임, 자신의 데이터센터에 저장된 불법정보에 대한 클라우드 서비스제공자의 책임범위, 클라우드 서비스제공자의 책임제한 등 현행법상의 법적 규제와 충돌되는 부분에 대해서는 법. 제도적 접근과 검토가 필요하다. 클라우드 컴퓨팅 산업의 촉진 및 이용 활성화를 위해서는 구체적으로 다음과 같은 사항이 법 제도적으로 검토되어야 한다. (1) 클라우드 서비스나 솔루션을 시험할 수 있는 테스트베드 구축 등 시범사업 근거 마련, (2) 분야별 특화된 클라우드 서비스 모델 개발 및 사업화를 위한정부시책 추진 및 지원 근거 마련, (3) 민 관의 포괄적 협력 기반조성 및 정부의 기술 개발연구 지원체계 마련, (4) 사전 인증 및 사후 보증체계 구축을 통한 클라우드 서비스의 신뢰성 및 안정성 제고, (5) 클라우드 서비스의 상호운용성 확보를 위한 표준화, (6) 클라우드 컴퓨팅의 정보보안, 개인정보보호 등 각종 법률 이슈와 예상되는 다양한 이해관계 충돌 문제에 대응할 수 있도록 서비스제공자와 이용자 대상의 지침 근거 마련, (7) 클라우드 속에 있는 기업의 정보지산에 대한 접근권 보장, (8) 정보자산의 실제 위치와 선택권 보장, (9) 정보자산의 부적절한 접근 방지와 오남용 방지, (10) 클라우드 서비스 제공기업 또는 서비스 자체의 영속성 보장, (11) 서비스 장애 책임범위와 분담, (12) 소프트웨어 라이선스 등에 대한 규정이 고려되어야 한다.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.21 no.1
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• pp.1-18
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• 1995

We had tested the effect of amino propane sulfonic acid(APSA) on the human skin with non-invasive technique. It was tested with four parameters that were hydration, elasticity, color and skin wrinkles. In vitro culture systems, APSA stimulated the proliferation of fibroblasts bolt it didn't stimulate that of keratinocyte. Also we obtained the similar effects in the raft culture method. So we concluded that APSA affected the dermal region than the epidermal region. In clinical tests, APSA changed the skin color, pbiomechanical properties(especially elasticity) and reduced skin wrinkles of the volunteers. And we could get the better results of skin wrinkle improvement by use of Skin Visiometer than Silflo Image analysis systems.

• The Journal of the Convergence on Culture Technology
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• v.9 no.4
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• pp.1-11
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• 2023

The purpose of this study is to develop a discussion-centered teaching and learning model for nurturing creative and convergence talents. Regarding the research method, a draft model on discussion-centered teaching and learning was devised, and the model was completed through expert validation. The final draft was revised and supplemented by verifying how valid the model was when applied in class by using the derived final draft. Compared with the draft on discussion-centered teaching and learning model, the final model focused on text-reading emphasis, methods of questioning, and question generation strategies, excluding jigsaw discussions. The discussion-centered teaching and learning model developed in this study is expected to help instructors foster creative and convergence talents. Three suggestions have been provided to effectively apply this model to the field. First, an attitude of listening and respect is required during a discussion. Second, a plan should be considered on how to induce active participation of learners participating in the discussion. Third, the importance of managing discussion time was emphasized.

• The Journal of Dong Guk Oriental Medicine
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• v.6 no.1
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• pp.91-106
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• 1997

The purpose of this study is to observe tile protective effect of Leeganpunsusan on serum reaction and hepatic tissue in galactosamine treated rats. In this study, the experimental rats divided three group(Normal, Control and sample group). Under the same condition, normal and control groups were administered water, sample group was administered Leeganpunsusan for 15 days. The last day, both normal and control goups were injected to abdomen with galactosamine. The rates of lipid peroxide, SOD(activity) and xanthine oxidase(activity) were measured. The results were obtained as follows : Effects of the extract of Leeganpnnsusan on the hepatic lipid peroxidation, xanthine oxidase activity in VITRO, as compared with control group were significantly decreased with the level of concentration of extract prepared from Leeganpunsusan. In VIVO, the hepatic content of lipid peroxide, the rate of type changing(type D to O) and xanthine oxidase activity were significantly decreased in galactosamine-treated rats. Effect of on the hepatic cytosolic superoxide dismutase activity was significantly increased.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
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• v.10 no.1
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• pp.50-63
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• 1999

Introduction：Test anxiety is a pervasive problem among high school students in Korea. While anxiety in test situations may actually facilitate the performance of some students, more often it is disruptive and leads to performance decrements. Over the past years, many child psychiatrists have become concerned with understanding the nature of test anxiety, but it is not clearly understood yet. In order to understand the nature of test anxiety, the relationship between test anxiety and depression, state anxiety, trait anxiety, temperament and family environment were examined. Methods：The Test Anxiety Inventory, Chidlren's Depression Inventory, State-Trait Anxiety Inventory, Temperamnet and Family Environment Scale Scale were administered to 576 high school students in Seoul. The relationships between test anxiety and other measures were tested using Pearson correlation coefficients and to test the causal relationship among the variables, regression analysis was performed. Results：The correlation coefficients between test anxiety and depression, state anxiety, trait anxiety, temperament and family environment scale were 0.42(p<0.01), 0.34(p<0.05), 0.38(p<0.05), 0.36(p<0.05) and -0.23(p<0.01), respectively. Regression analysis showed that only state and trait anxiety had direct causal relationship with test anxiety. Depression, temperament and family environment were indirecly related with test anxiety. Conclusions：This study indicates that the level of state and trait anxiety are directly related with test anxiety, and other variables such as temperament, family environment and depression are indirectly related with test anxiety. Thus, in order to develop the effective methods for treatment, these psychopathological characteristics should be kept in mind and the most important factors are the levels of state and trait anxiety.

• Polymer(Korea)
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• v.30 no.3
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• pp.259-265
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• 2006

Small intestinal submucosa (SIS) consists of some growth factors which can stimulate cell activity, and PVA has been widely utilized in the area of wound dressing as hydrogel which is easy to be removed from wounds. In this study, native SIS sheets were coated with PVA by immersing them into 2, 4, and 10 wt% of PVA solution and then lyophilized on two type of molds to endow the prepared wound dressing with easy removal property from wounds. The mechanical properties were examined through tensile test. Moreover, enzymatic degradation, water uptake, and in vitro test were carried out to characterize the prepared SIS sheets. The tensile strength of the SIS sheets coated with PVA (PVA-SIS) were decreased, whereas the elongation were increased. Degradation ratio of the PVA-SIS sheets was decreased compare to native SIS. Water uptake ability was improved at 2 and 4 wt% of PVA. The degree of fibroblast attachment was lower than the native SIS sheets. In conclusion, this study suggests that the PVA coated SIS sheets have a potential for the applications of wound dressing and biodegradable injectable materials.

• Applied Biological Chemistry
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• v.24 no.1
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• pp.1-6
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• 1981

Studios on the effects of rice straw amendments, soil autoclaving and repeated application related to disappearance of diazinon (diethyl 2-isopropyl -4-methyl -6-pyrimidinyl phosphorothionate) in submerged soils and paddy water were conducted under the laboratory conditions. Degradation of diazinon was slightly accelerated by the amendment of rice straw. The amended soil had 2.4 days shorter half life for diazinon than unamended soil. By autoclaving soils, diazinon degradation was greatly inhibited. The autoclaved soil had about 20 days longer half life for diazinon than the non-autoclaved soil. After repeated application of diazinon granules to the submerged soils, rapid degradation of the insecticide occured in flooded soils and paddy water. The development of diazinon degrading factors in flooded soils and paddy water after repeated application was roughly proportional to the increase of the frequency of diazinon application. By autoclaving soils and paddy water which received repeated application of diazinon, no rapid biodegradation of the insecticide occurred during the 30 days incubation period.