• Journal of Life Science
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• v.32 no.2
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• pp.175-188
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• 2022

Relaxin has been demonstrated to have regulatory functions on both the smooth muscle and extracellular matrix (ECM) of blood vessels and fibrotic organs. The diverse mechanisms by which relaxin acts on small resistance arteries and fibrotic organs, including the bladder, are reviewed here. Relaxin induces vasodilation by inhibiting the contractility of vascular smooth muscles and by increasing the passive compliance of vessel walls through the reduction of ECM components, such as collagen. The primary cellular mechanism whereby relaxin induces arterial vasodilation is mediated by the endothelium-dependent production of nitric oxide (NO) through the activation of RXFP1/PI3K, Akt phosphorylation, and eNOS. In addition, relaxin triggers different alternative pathways to enhance the vasodilation of renal and mesenteric arteries. In small renal arteries, relaxin stimulates the activation of the endothelial MMPs and EtB receptors and the production of VEGF and PlGF to inhibit myogenic contractility and collagen deposition, thereby bringing about vasodilation. Conversely, in small mesenteric arteries, relaxin augments bradykinin (BK)-evoked relaxation in a time-dependent manner. Whereas the rapid enhancement of the BK-mediated relaxation is dependent on IK_Ca channels and subsequent EDH induction, the sustained relaxation due to BK depends on COX activation and PGI₂. The anti-fibrotic effects of relaxin are mediated by inhibiting the invasion of inflammatory immune cells, the endothelial-to-mesenchymal transition (EndMT), and the differentiation and activation of myofibroblasts. Relaxin also activates the NOS/NO/cGMP/PKG-1 pathways in myofibroblasts to suppress the TGF-β1-induced activation of ERK1/2 and Smad2/3 signaling and deposition of ECM collagen.

• Journal of The Korean Association of Information Education
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• v.4 no.2
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• pp.187-201
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• 2001

A project learning is the model to solve the problem in cooperation with the members of a group. The purpose of this study is to make a new learning model using a web on the traditional project learning model. A Web has the proper nature for students to make their learning environment, so that this study embodied Student Directed Web based project learning system to allow them to expand their abilities. All action of students, that is, suggesting main subject, making plans, activating and adjusting them, and evaluation can be happened in this system. According to the result of applying the system, participants in Students Directed Web based Project Learning intend to implement learning activities more positively, affirmatively and cooperatively than the existing ones.

• Journal of The Korean Association of Information Education
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• v.6 no.2
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• pp.141-153
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• 2002

A project-based learning is the model to solve the problem in cooperation with the members of group. The purpose of this study is to make level learning system using a web on the project-based learning. A Web has the proper nature for students to make their learning environment, so that this study embodied student directed to allow them to expand their abilites. All action of students, that is, suggesting main subject, making plans, activating and adjusting them, and evaluation can be happened in this system. Acoording to the result of applying the system, participants in students Directed level Web based Project Learning intend to implement learning activitis more positively, directly, cooperatively than the existing ones.

• 한국정보교육학회:학술대회논문집
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• 2010.08a
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• pp.19-25
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• 2010

Education delivers knowledge through story. On that point Storytelling is related to education. However, the problem is raised that Storytelling in school is leaning toward teachers that's why it makes students passive story listeners. Therefore, this study developed Digital Storytelling material using in the education for elementary school students. It leads them to be able to interact actively. So, I organized applicable 12 themes for 24 times training contents in after-school tutoring program because Digital Storytelling education doesn't perform in elementary school yet. If the material is used in classes, I expect to increase learners' self-expressiveness and creativity, and besides to train the ability of adapting and taking the lead in this changing society by contributing the spread of the Digital Storytelling education. Finally, in a follow-up study, it is demanded to verify an educational effect of this material and to redesign the process of these material contents through application in studying.

• The Korean Journal of Physiology
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• v.17 no.2
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• pp.143-159
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• 1983

Vanadate가 가토 신피질절편에서 PAH이동과 Na-K-ATPase활성에 미치는 효과를 관찰한 결과 다음과 같은 결론을 얻었다. 1) Vanadate는 Na-K-ATPase활성을 농도에 따라 억제하였으며 $7.94{\times}10^{-7}M$에서 이 효소의 활성이 50% 억제되었다. 2) Vanadate는 PAH의 능동적이동을 농도에 따라 억제하였으며 50%억제농도는 대략 $10^{-4}M$ 이었고, 수동적이동에는 영향을 미치지 못하였다. 조직내 Na과 K의 양도 vanadate가 PAH이동을 억제하는 농도 범위에서 같이 변화하였고 산소소모량은 $10^{-4}M$까지는 약간 감소하였으나 $10^{-3}M$에서는 오히려 증가하였다. 3) 30분간 preincubation한 후에도 15분까지의 PAH이동은 30분 이후에 비해 vanadate에 의해 적게 억제되었다. 4) $10^{-4}M$ vanadate와 $10^{-4}M$ ouabain은 가역적으로 PAH 이동을 억제하였으며 $10^{-3}M$ vanadate는 비가역적으로 억제하였고 장시간 세척후에도 거의 같은 정도의 억제양상을 나타내었다. 5) Vanadate에 의한 PAH이동의 억제정도는 incubation용액내 $Na^+$의 감소, $K^+$의 증가에 의하여 증가하였고 $Ca^{2+}$의 농도 변화에 의해서는 영향을 받지 않았다. 6) Vanadate가 존재치 않을 때 Tris완충용액 사용시는 pH 8.2까지 PAH축적정도가 증가하였고 phosphate완충용액 사용시는 pH 7.4에서 최대축적치를 보였다. pH가 증가함에 따라 억제정도는 증가하였으며 같은 pH에서도 완충용액의 종류에 따라 vanadate에 의한 억제정도가 달랐다. 7) Vanadate와 ouabain은 PAH이등과 Na-K-ATPase활성에 부가적 억제작용을 나타내었다. 이상의 결과로 vanadate는 가토신장의 세포내부에서 Na-K-ATPase를 가역적으로 억제함으로써 PAH의 이동을 억제하는 것으로 생각되며 PAH의 이동은 Na-K-ATPase활성과 기능적으로 밀접히 연결되어 있는 것으로 생각된다.

• ETRI Journal
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• v.14 no.4
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• pp.217-227
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• 1992

최근 이동통신 및 위성통신 등 마이크로웨이브를 이용하는 통신분야의 시장이 급속히 신장됨에 따라 RF(Radio Frequency) 부품의 산업적 중요성이 부각되고 있다. RF 부품은 크게 능동부품과 필터로 대표되는 수동부품으로 대별되는데, duplexer나 필터는 현재 대부분 마이크로웨이브 세라믹유전체를 사용 제조하고 있다. 본 연구에서는 이들 부품들에 사용가능한 세라믹유전체를 개발하기 위한 연구의 일환으로 BaO-$Sm_2$$O_3$-$TiO_2$계 세라믹의 마이크로웨이브 유전특성과 여기에$La_2\$$O_3$를 첨가한 계인 BaO-($Sm_1$$-_X$$La_X$$)_2$$O_3$-$TiO_2$ 세라믹유전체를 제조하여 마이크로웨이브 유전특성을 살펴보았다. RF 부품에 사용되는 세라믹유전체는 높은 유전율$\varepsilon_r$높은 품질계수 (Q) 및 안정된 온도특성 $\tau_f$ 등의 조건을 충족시켜야한다. 본 연구에서는 유전체의 $\varepsilon_r$ 및 Q의 측정에 디스크형 유전체공진기와 두개의 도체평행판을 사용한 Hakki-Coleman법을 사용하였으며, $\tau_f$는 fixture를 항온조에 넣어서 측정하였다. BaO-$Sm_2O_3-TiO_2$계의 경우 소결온도 $1350^{\circ}C$까지는 $\varepsilon_r$및 Q가 증가하나 그 이상의 소결온도에서는 감소한다. 그리고 $\tau_f$는 $-35_{ppm}/^{\circ}C$에서 소결온도에는 거의 의존하지 않았다. $La_2O_3$를 첨가한BaO-($Sm_1$$-_X$$La_X$$)_2$$O_3$-$TiO_2$ 세라믹의 마이크로웨이브 유전특성은 $La_2O_3$의 첨가량이 많을수록 $\tau_f$값이 음에서 양으로 이동함이 관찰되었으며, x=0.15에서 $\tau_f$가 0이 되어 마이크로웨이브 부품용 마이크로웨이브 세라믹유전체를 얻을 수 있음이 확인되었다.

• Journal of The Korean Society of Integrative Medicine
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• v.4 no.1
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• pp.31-39
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• 2016

Purpose : The purpose of this study was to investigate the effects of flexibility and foot pressure on stretching exercise of hamstring muscle with and without pelvis neutral position. Methods : This study was performed on 30 subjects. Thirty subjects were divided into two group; hamstring passive stretching exercise with pelvis neutral position(n=15), hamstring passive stretching exercise without pelvis neutral position(n=15). Both of the group performed the exercise 4 times a week for 6 weeks. The data was analyzed by the paired t-test for comparing before and after changes of factors in each group and the independent t-test for comparing the between groups. Results : The results were as follows. There was statistically significant difference of before and after hamstring flexibility, foot pressure in pelvis neutral position(p<0.05). There was statistically significant difference of before and after hamstring flexibility, foot pressure without pelvis neutral position group(p<0.05). There was no statistically significant difference of between the two group in hamstring flexibility, foot pressure(p>0.05). Conclusion : As a result of this study, though no statistically significant difference of the between groups, we suggest that stretching exercise of hamstring muscle with pelvic neutral may be effective more than stretching exercise of hamstring muscle without pelvic neutral in flexibility, foot pressure.

• Journal of The Korean Association of Information Education
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• v.7 no.2
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• pp.227-237
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• 2003

Conventional studies of Computer Assisted Instruction(CAI) and Intelligent Tutoring System(ITS) have been general patterns to solve problems, so to solve specialized problems, the learner which has the attitude of passiveness should to solve problems including unnecessary processing to the need of the system. Consequently, those are not support the process of creativity and individual problems for the learner to solve the fractional number operations as this study. This study is the design and implementation of ITS on the fractional number addition and subtraction for the supplementary student. Our system can diagnosis mistakes of learning and guide the student to know their errors of learning process automatically And our system assist the learners to study with self-initiative learning, replacement their lacking of learning and control the process of fractional addition and subtraction operation with creativity according to their level. We showed that this system had improved problems of lacking care to supplementary student result in are not enough teachers involved their school and that the learner had achieved the higher learning effect according to the improved self-initiative learning causing this system.

• Analytical Science and Technology
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• v.13 no.6
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• pp.693-698
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• 2000

The object of this series of experiments was aimed for the systematic and long-term radioactivity monitoring through indirect search of C-14 concentration level changes in the natural conditions around the operating nuclear facilities. The result of environmental radioactivity level through tree-ring analysis is increased after operating nuclear facilities and such a level can be proved to relate power generation closely. The measured result of ${\delta}^{13}C$ through the treatment of cellulose can be showed the level -30‰. This figure is very different from one which is measured the -17‰ of air sample by passive air sampling and -8‰ of air sample by active air sampling. And these differences can be assumed as isotope fractionation by photosynthesis, but the problem is more study as needed.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.24 no.2
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• pp.297-303
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• 2020

This study compared the perceptions of novice teachers and expert teachers on software education in the 2015 revised curriculum. Awareness comparisons were assessed by questionnaire for priorities for field support, activities for professional development, organizational hours, achievement criteria statements, and appropriateness for textbooks introduced only in 6th grade. In all questions, there was a difference in recognition between the two groups. In particular, novice teachers were '' appropriate '' in terms of organizational hours, achievement criteria, and textbooks introduced only in 6th grade. Expert teachers, on the other hand, were inadequate. In addition, as a result of analyzing the key keywords of free-response opinions about the introduction of educational robots in the curriculum and textbooks, positive keywords were obtained for both groups. However, novice teachers showed passive and passive keywords such as 'support', 'difficulty', and 'problems', and expert teachers showed differences in their educational utilization after introducing 'utilization' and 'education'.