• The Journal of Information Systems
• /
• v.17 no.4
• /
• pp.233-260
• /
• 2008

Universities have recognized e-Learning Systems as the critical IT resources which contribute to improving the competitiveness of the universities as well as the quality of the traditional class-based lectures. Instructors deliver the main contents in the class. Other supplementary activities like online discussions, sharing of teaching-learning materials, submission of homeworks, communication among the learners and between the instructors and the learners, and so on can be efficiently facilitated using e-Learning Systems. In other words, e-Learning Systems enable a blended learning combined class-based lectures and e-learning in a variety of ways. Nonetheless, compared to the level of implementation of e-Learning Systems, the usage of both the instructors and the learners is not high. Accordingly, this study examines the determinants to affect on the usage of e-Learning Systems from the learners perspective. To draw the key determinants, we review the IS literatures related to adoption or use of the IS like Media Richness Theory (MRT), Technology Acceptance Model (TAM), Social Influence Model (SIM), and Self-efficacy Model. The variables are drawn out to be expected on the usage of e-Learning like Media Richness, Ease of Use from MRT, TAM and Instructor's Influence, Co-learner's Influence from SIM, and Self-efficacy. To test our model and hypotheses, we have collected data in the class-based lectures using e-Learning System complementary. The results of the test with 192 data are as follows: Firstly, it shows that the Instructor's Influence and the Media Richness are the influential determinants to affect on the Perception of Usefulness of e-Learning Systems. Additionally, the Co-learner's Influence and Ease of Use in order is significant to the Perception of Usefulness. Secondly, as to the degree of use of the e-Learning Systems, the Co-leaner's Influence, the Media Richness, and the Ease of Use are, in that order, the significant determinants. The Perception of Usefulness, also, founded a key factor on increasing the use of e-Learning Systems. On the other hand, the Instructor's Influence is not significant to the use of e-Learning Systems. Finally, it has been found that Self-efficacy is significant to the Perception of Media Richness, Ease of Use, but not significant to the Perception of Usefulness.

• Biomedical Science Letters
• /
• v.18 no.3
• /
• pp.260-267
• /
• 2012

Obesity is associated with cardiovascular risk factors, such as dyslipidemia, hypertension and diabetes. However the presence of the obesity related deranged metabolic profiles varies widely among obese individuals. These individuals, known as 'metabolically healthy obese phenotype (MHO)', despite having excessive body fatness, display favorable metabolic profiles characterized by insulin sensitivity, no hypertension, as well as less dyslipidemia, less inflammation. The purpose of this study was to compare cardiac characterization and clinical profile of MHO and Non-MHO (nonmetabolically healthy obese) subjects in men. We measured treadmill exercise capacity (METs) and maximum blood pressure (BP) in 210 subjects through a medical checkup at J General Hospital. Metabolic syndrome was defined according to the modified Adult Treatment Panel III definition criteria. Both MHO and Non-MHO subjects showed statistically significant changes in the left ventricular mass index (P<.001, P<.01, respectively), A-velocity (P<.01, P<.001, respectively), E/A ratio (P<.01, P<.001, respectively), E'-velocity (P<.001, P<.001, respectively), HOMA-IR (P<.01, P<.001, respectively) and maximum systolic BP (P<.01, respectively) compared with the MH-NO (metabolically healthy non obese) subjects. In conclusion, MHO participants were at increased risk of cardiovascular disease and partly metabolic disorder.

• Journal of Korean Society of Water and Wastewater
• /
• v.19 no.1
• /
• pp.38-46
• /
• 2005

In this research, we tried to combine the coagulation/sedimentation process as pre-treatment with UF membrane filtration to reduce the membrane fouling and to improve the permeate water quality. We used the Jet Mixed Separator (JMS) as coagulation/sedimentation process. We observed that the HPC and E.Coli can't be removed through the direct UF memebrane filtation of surface water. The removal efficiency of dissolved organic substances, indicated by E260 and DOC, was 40% and 15%, respectively. However, the removal efficiency of it increased two time as a result of combination of JMS process as coagulation/sedimentation pre-treatment. This was resulted from the formation of high molecular humic micro-floc through JMS process. The accumulation amount of irreversible cake layer which was not removed by backwashing was less than direct UF membrane filtration of surface water. Moreover, the loading rate of fouling induced substances, such as humic substances and suspended substances, on membrane surface decreased drastically through JMS process. As a result, the accumulation amount of irreversible cake on membrane surface was decreased.

• Journal of Korean Neurosurgical Society
• /
• v.29 no.7
• /
• pp.861-867
• /
• 2000

Purpose : Neuronal migration disorder(NMD) is a major underlying pathology of patients with intractable epilepsy. The role of NMD on seizure susceptibility or epileptogenecity, however, has not been documented. Methods : External irradiation of total amount of 250 cGY was performed to the fetal rats on days 16(E16) and 17(E17) of gestation. After delivery, the rats of 230-260g were decapitated for the histopathologic study. Epileptog-enecity of the NMD was studied by observing electroclinical events after intraperitoneal kainic acid(KA) injection in the control rats and NMD rats. Results : Histopathologic findings revealed focal and/or diffuse cortical dysplasia consisting of dyslamination of the cerebral cortex and appearance of the cytomegalic neurons, neuronal heterotopia in the periventricular white matter, dispersion of the pyramidal layer and the dentate gyrus of the hippocampus, and agenesis of the corpus callosum. Abnormal expression of neurofilaments protein(NF-M/H) was characteristically observed in the dysplastic neurons of the neocortex and hippocampus. Early ictal onset and prolonged ictal activity on EEG and clinical seizures were observed from the NMD rats unlike with the control rats. Conclusions : Exteranl irradiation on the fetal rats produced NMD. And the rats with NMD were highly susceptible to kainic acid provoked seizures. This animal model would be useful to study the pathophysiology of clinically relevant NMDs.

• 한국신재생에너지학회:학술대회논문집
• /
• 2007.06a
• /
• pp.257-260
• /
• 2007

In this study, $CuInSe_{2}$ (CISe) and $CuInZnSe_{2}$ (CIZSe) thin films were prepared on Corning 1737 glass by radio frequency (RF) magnetron sputtering from binary chalcogenide mixed powder targets. The targets were initially prepared by mixing appropriate weights of CuSe, InSe powder and various ZnSe contents. From the film bulk analysis result, it is observed that Zn concentration in the films increases proportionally with the addition of ZnSe in the sputtering targets. Under optimized conditions, CISe and CIZSe thin films grow as a chalcopyrite structure with strong (112), (220/204) and (312/116) reflections. Films are found to exhibit a high absorption coefficient of $10^{4}$ $cm^{-1}$. An increasing of optical band gap from 1.0 eV (CISe) to 1.25 eV (CIZSe) is found to be proportional with an increasing of Zn concentration as expected. All films have a p-type semiconductor characteristic with a carrier concentration in the order of 1014 $cm^{-3}$, a mobility about $10^{1}$ $cm^{2{\cdot}-1}{\cdot}s^{-1}$ and a resistivity at the range of $10^{2}-10^{6}$ W${\cdot}$m.

• The Journal of Asian Finance, Economics and Business
• /
• v.6 no.4
• /
• pp.249-260
• /
• 2019

The study examines the impact of financial risk, convenience risk, non-delivery risk; return policy risk and product risk on online consumer behavior of Malaysian consumers. The research employed a self-administered survey to collect empirical data from 245 Malaysian online shoppers by using convenience sampling. Cronbach alpha was calculated to confirm the reliability of the data and then normality was assessed. Confirmatory Factor Analysis was then conducted to test the model using the goodness-of-fit tests. And finally, structural equation modeling is used to test the hypotheses and draw conclusions. IBM SPSS AMOS version 22.0 was utilized for data analysis. The research indicates that product risk, convenience risk, and return policy risk have a significant and positive impact on online shopping behavior. Financial risk is found to have insignificant and negative effects on consumer behavior. In addition, the non-delivery risk is found to have a significant and negative impact on online shopping behavior. The findings provide a useful model for measuring and managing perceived risk in online shopping which may result in an increase in participation of Malaysian consumers and reduce their cognitive deficiencies in the e-commerce environment. Several managerial implications are discussed along with the scope for future research.

• Proceedings of the KSRS Conference
• /
• v.1
• /
• pp.260-262
• /
• 2006

One of future remote sensing techniques for transportation application is vehicle detection from the space, which could be the basis of measuring traffic volume and recognizing traffic condition in the future. This paper introduces an approach to vehicle detection using image object segmentation approach. The object-oriented image processing is particularly beneficial to high-resolution image classification of urban area, which suffers from noisy components in general. The project site was Dae-Jeon metropolitan area and a set of true color aerial images at 10cm resolution was used for the test. Authors investigated a variety of parameters such as scale, color, and shape and produced a customized solution for vehicle detection, which is based on a knowledge-based hierarchical model in the environment of eCognition. The highest tumbling block of the vehicle detection in the given data sets was to discriminate vehicles in dark color from new black asphalt pavement. Except for the cases, the overall accuracy was over 90%.

• Proceedings of the Korean Vacuum Society Conference
• /
• 2014.02a
• /
• pp.461.1-461.1
• /
• 2014

본 연구진에서는 기존에 Ag2S 양자점을 흡광층으로 활용하여 양자점 감응형 태양전지(QDSC)를 제작, 그 성능과 특징을 분석하여 발표한 바 있다. 기존 연구에서 제작된 Ag2S QDSC는 11 mA/cm2의 비교적 높은 광전류와 260 mV의 비교적 낮은 전압으로 인해 1.2%의 광전환효율 성능을 나타내는 것으로 보고되었다. 추후 연구로 진행된 본 결과에서는, 기존에 Single absorber로 사용된 Ag2S의 한계를 보완하기 위해 CdS를 도입하여 co-sensitization을 활용하였다. CdS는 약 2.3 eV의 밴드갭 에너지를 갖는 물질로, 1.1 eV의 밴드갭을 갖는 Ag2S에 비해 흡광 영역은 좁지만 그만큼 전자-정공 재결합을 억제할 수 있는 장점을 가지고 있다. 또한, 전도층으로 사용한 n-type 물질인 ZnO 나노선과의 밴드구조가 매우 적합하게 조화되어, ZnO/CdS/Ag2S 순서로 이종구조를 접합시켰을 때 세 물질의 Conduction band level과 Valence band level이 순차적으로 연결되는 cascade-shaped 밴드구조를 이루게 된다. 빛을 받아 Ag2S와 CdS에서 생성된 전자는 이 cascade 모양의 conduction band를 따라 순차적으로 ZnO로 잘 전달되게 되어, 효율 향상에 큰 도움을 주었다. 이런 장점들로 인해, CdS-Ag2S co-sensitized QDSC는 Ag2S QDSC에 비해 2배나 향상된 효율인 2.4%를 기록하였으며, 이는 IPCE spectrum 측정 등으로 근거가 뒷받침되었다.

• Journal of Microbiology and Biotechnology
• /
• v.3 no.4
• /
• pp.256-260
• /
• 1993

DNA subfragments, sopA, sopB and sopC which help to maintain the stability of an ori C plasmid, were derived from a mini-F plasmid DNA (EcoRI restriction fragment f5) after digestion with restriction endonuclease, and cloned in the vector plasmid pBR322. The recombinant plasmids obtained were introduced into E. coli KY7231 and E. coli CSR603 strains, and proteins specified by the mini-F fragments were analysed by SDS-PAGE. Two proteins encoded by the F fragments were detected, and their molecular weights were 41,000 and 37,000 daltons. Fluorography after one and two dimensional gel electrophoresis of the lysates showed that these two proteins had been overproduced in the cells which were allowed to incorporate radioactive amino acid after plasmid amplification by chloramphenicol treatment. The isoelectric points of sopA and sopB proteins were 6.6 and 7.0, respectively.

• 한국지구물리탐사학회:학술대회논문집
• /
• 2007.06a
• /
• pp.257-260
• /
• 2007

Two-dimensional (2D) interpretation of MT and AMT data observed in 2004 in Jeju Island is made using two inversion schemes developed by Uchida (1993) and Lee et al. (2002). These interpretations show that the subsurface of Jeju consists of roughly three layers. Reconstructed images along lines E and W reveal that the conductive layer beneath the topmost resistive layer of lava plateau can be a sediment layer. The geoelectrical structure along line E is more complex than that along line W, especially near Mt. Halla. The Uchida’s (1993) scheme gives reasonable images, but much more time-consuming than that of Lee et al. (2002).