• Transactions of the Korean Society of Automotive Engineers
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• v.20 no.4
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• pp.142-149
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• 2012

The reduction characteristics of $NO_2$ to NO are experimentally studied over a platinum-based catalyst, especially at lower temperatures below about $200^{\circ}C$. In the present work, two types of steady-state experiments, engine bench and synthetic gas bench tests, are carried out in sequence. Steady-state engine bench tests with the DOC mounted on a light duty 4-cylinder 2.0 liter turbocharged diesel engine are performed and prove that CO plays a major role in $NO_2$ abatement at temperatures below the light-off temperature of CO oxidation, about $200^{\circ}C$. Synthetic gas bench tests are then performed using synthetic gas mixtures with CO, $C_3H_6$, NO, $NO_2$, $O_2$, $H_2O$ and $N_2$ in the $140{\sim}450^{\circ}C$ T-range and show that both CO and $C_3H_6$ are capable of reducing $NO_2$. It is noted that the reaction rate of $NO_2$ with $C_3H_6$ is much higher than that with CO. At temperatures below about $200^{\circ}C$, the reduction of $NO_2$ to NO is promoted with increasing CO concentration and $NO_2$/$NO_X$ ratio and with decreasing $O_2$ concentration, as well as with the presence of $H_2O$.

• Archives of design research
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• v.19 no.3 s.65
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• pp.183-194
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• 2006

It is expected that the typical lifestyle of the future will be transformed into an opulent and comfortable existence as the quality of life improves due to the increase in household income and reduction in working hours. In the meantime, as the standard of living becomes increasingly more comfortable and plentiful, the toll on physical health becomes magnified as a result of obesity and insufficient exercise caused by super nutrition and change in labor conditions. This has instigated a deep awareness in fitness on the part of many people, forcing them to recognize the significance of daily exercise and physical activity. The Elliptical Cross Trainer(ECT), which has drawn wide attention recently, is a non-impact athletic apparatus that not only promotes exercise of the upper body parts in such sports as skiing but also the exercise of lower parts of the body on a treadmill. It is a type of cross training athletic gear that has been developed for aerobic exercise throughout the entire body. It has already formed a market as big as that of the treadmill in Europe, America, etc. Recently, its demand is growing sharply in the Korean markets as well as those in Northeast Asian countries. Despite such demand increase and expansion, since most of the expensive ECTs are exclusively supplied by suppliers in only a few advanced countries, localization of the ECT is urgently required in order to enhance competitiveness of Korean manufacturers and to expand the market. The ECT development project has been in full swing for approximately two year since 2004 in order to secure independent design, as well as engineering and manufacturing processes in efforts to develop a commercially viable ECT.

• Journal of Korean Neurosurgical Society
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• v.42 no.6
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• pp.455-461
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• 2007

Objective : It was hypothesized that dopamine agonist administration and subthalamic nucleus (STN) lesion in the rat might have a synergistic effect on the neuronal activities of substantia nigra pars reticulata (SNpr) as observed in patients with Parkinson's disease. The effects of SKF38393 (a $D_1$ receptor agonist) and Quinpirole (a $D_2$ receptor agonist) were compared in parkinsonian rat models with 6- hydroxydopamine (6-OHDA) after STN lesion. Methods : SKF38393 and Quinpirole were consecutively injected intrastriatally. SNpr was microrecorded to ascertain the activity of the basal ganglia output structure. The effect of SKF38393 or Quinpirole injection on the firing rate and firing patterns of SNpr was investigated in medial forebrain bundle (MFB) lesioned rats and in MFB+STN lesioned rats. Results : The administration of SKF38393 decreased SNpr neuronal firing rates and the percentage of burst neurons in the MFB lesioned rats, but did not alter them in MFB+STN lesioned rats. The administration of Quinpirole significantly decreased the spontaneous firing rate in the MFB lesioned rats. However, after an additional STN lesion, it increased the percentage of burst neurons. Conclusion : This study demonstrated that dopamine agonists and STN lesion decreased the hyperactive firing rate and the percentage of burst neurons of SNpr neurons in 6-OHDA lesioned rats, respectively. Quinpirole with STN lesion increased a percentage of burst neurons. To clear the exact interactive mechanism of $D_1$ and $D_2$ agonist and the corresponding location, it should be followed a study using a nonselective dopamine agonist and $D_1$, $D_2$ selective antagonist.

• The Korean Journal of Physiology and Pharmacology
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• v.21 no.1
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• pp.11-17
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• 2017

Crohn's disease (CD) is a chronic inflammatory bowel disease with multifactorial causes including environmental and genetic factors. Several studies have demonstrated that the organic cation/carnitine transporter 1 (OCTN1) non-synonymous variant L503F is associated with susceptibility to CD. However, it was reported that L503F is absent in Asian populations. Previously, we identified and functionally characterized genetic variants of the OCTN1 promoter region in Koreans. In that study, four variants demonstrated significant changes in promoter activity. In the present study, we determined whether four functional variants of the OCTN1 promoter play a role in the susceptibility to or clinical course of CD in Koreans. To examine it, the frequencies of the four variants of the OCTN1 promoter were determined by genotyping using DNA samples from 194 patients with CD and 287 healthy controls. Then, associations between genetic variants and the susceptibility to CD or clinical course of CD were evaluated. We found that susceptibility to CD was not associated with OCTN1 functional promoter variants or haplotypes showing altered promoter activities in in vitro assays. However, OCTN1 functional promoter haplotypes showing decreased promoter activities were significantly associated with a penetrating behavior in CD patients (HR=2.428, p=0.009). Our results suggest that the OCTN1 functional promoter haplotypes can influence the CD phenotype, although these might not be associated with susceptibility to this disease.

• Korean Journal of Agricultural Science
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• v.37 no.1
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• pp.27-35
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• 2010

A study examined visitors' satisfaction to urban arboretum in Daejeon metropolitan city, and analyzed utilization status. Also, the study was based on POE. POE is a last phase in the environmental planning and design process that follows the sequence of planning, programing, design construction, and use of a project. Urban arboretum contribute to improvement in the quality of living by providing urban citizens with places for refreshment, natural have important values on urban environment and to promote the quality of life for urbanite. So, the study aims to present data on the human activities responding to the physical environment of 'the Daejeon Hanbat Arboretum' by evaluating visitor's behavior and activity, visiting motivations, preference patterns, and the degree of visitor's satisfaction. This study is conducted by multi-method such as interviews and questionnaires surveys. On-site questionnaire surveys were conducted in the Hanbat arboretum on October 25-31 of 2009. Total of 265 questionnaires were analyzed for this study. The analysis of data was used SPSS 18.0 statistical analysis program. Data from visitors was analyzed by descriptive statistics, frequency analysis, multiple response analysis, and Anova. Then, the outcome will be compared and evaluated to install urban arboretum that reflect the desires of users in the future.

• Korean Journal of Construction Engineering and Management
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• v.6 no.4 s.26
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• pp.71-79
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• 2005

As construction projects have been extremely enormous, complex and special, risk factors have been increased consistently. Therefore, it is very important to identify and cope with the uncertain risk factors in such building constructions for successful project accomplishment. The purpose of this research is to approach practical affairs directly and show detail alternatives of risk factors by extracting the risk factors throughout construction process of curtain wall that is largely influenced on cost, quality, schedule ,safety and following activity. Also, extracting these risk factors make it possible to analyze quantitative risk and decide the priority raking of risk factors. Especially, this research is aimed to provide efficient management of scheduling risk that can make the risk minimize to practical workers who have different degree of knowledge and experience to the construction cite when the risk brings out suddenly.

• Journal of Korean Elementary Science Education
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• v.23 no.3
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• pp.192-198
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• 2004

The purpose of this study was to analysis the curriculum for educating and operating the classes of elementary science gifted in Incheon Metropolitan Office of Education. We developed the framework for curriculum content analysis based on the principles of curriculum development for gifted education. The developed framework was applied to the curricula of four classes of elementary science gifted in Incheon. And the needs of gifted students were surveyed in the classes of the elementary science gifted. The results of this study were as follows: 1. The current curriculums of two classes described the goal of the elementary gifted education, but the content and theme of the curricula of three classes were not related to the contents of the 7th national curriculum. 2. The teaching methods used in the science gifted class were mainly a lecture and an experimental activity. and there was little the process of individual instruction. 3. There was not mostly the products as the results of learning because of little performed by a project teaming, an announcement and an exhibition in gifted class. 4. Most of the students of the science gifted class were estimated by the paper tests and observation of the teacher in charge of the gifted class, not by the products and presentation etc. 5. They mostly preferred the theme of everyday life in addition to the textbook, and the instructional type of enrichment teaming and acceleration learning over the grade of themselves. 6. They mainly expected that the curriculum of the gifted class is operated during the semester.

• Biomedical Science Letters
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• v.20 no.2
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• pp.85-95
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• 2014

Activation of the epidermal growth factor receptor (EGFR) and downstream signaling pathways have been implicated in causing resistance to EGFR-targeted therapy in solid tumors, including the head and neck tumors. To investigate the mechanism of antiproliferation to EGFR inhibition in oral cancer, we compared EGFR tyrosine kinase inhibitor (Gefitinib, Iressa, ZD1839) with respect to its inhibitory effects on three kinases situated downstream of EGFR: MAPK, Akt, and glycogen synthase kinase-$3{\beta}$ (GSK-$3{\beta}$). We have demonstrated that ZD1839 induces growth arrest and apotosis in oral cancer cell lines by independent of EGFR-mediated signaling. An exposure of oral cancer cells to ZD1839 resulted in a dose dependent up-regulation of the cyclin-dependent kinase inhibitor p21 and p27, down regulation of cyclin D1, inactivation of GSK-$3{\beta}$ and of active MAPK. In resistant cells, GSK-$3{\beta}$ is constitutively active and its activity is negatively regulated primarily through Ser 9 phosphorylation and further enhanced by Tyr216 phosphorylation. These results showed that the resistance to the antiproliferative effects of ZD1839, in vitro was associated with uncoupling between EGFR and MAPK inhibition, and that GSK-$3{\beta}$ activation and degradation of its target cyclin D1 were indicators of high cell sensitivity to ZD1839. In conclusion, our data show that the uncoupling of EGFR with mitogenic pathways can cause resistance to EGFR inhibition in oral cancer.

• Journal of The Korean Association of Information Education
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• v.7 no.2
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• pp.207-217
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• 2003

Individual studying that compose knowledge and improve efficiency of studying through collection of information by various class strategy which takes advantage of web, and Cooperative learning that can elevate sense of responsibility and solve the problem through communication with another person have been developed actively. But, individuation tutoring materials that is developed present doesn't fit of causing learner's interest, and stimulating curiosity about problem because mostly studying is gone in presentation form. Also, cooperative learning materials are lacking connection with actual course of education, application is difficult in real class spot. So, this research has applied self-directed learning, centered with interested operation activity, aimed at improvement in various thought. Also, we have developed social studies tuition-learning system, purpose to the management is possible with on-line project studying which could improve mind-decision ability and ICT application ability. This system is developed for flexible management could be possible in various class circumstance, and level learning could be done through accomplishment-test and the result could be applied by feedback process.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2006.11a
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• pp.422-426
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• 2006

Productivity is one of the very important index that measures efficiency of production activities in industry, enterprises and the building industry as well. None the less, the concept of construction productivity is not so clear that productivity management in the building industry have been performed by experience or intuition, productivity related data have not been analyzed through effective productivity management, because structured definition and classification of factors influencing construction productivity did not exist so that it has not been known what information explain each of them. In order to solve this problem, at first construction productivity and factors influencing construction productivity are defined and classified into three groups; (1)Project factors influencing construction productivity (2)Management factors influencing construction productivity (3)Activity factors influencing construction productivity. To find out relation between construction productivity and factors influencing construction productivity, a questionnaire survey for construction managers in the building industry has been conducted.