• Journal of the Korean Society of Visualization
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• v.17 no.2
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• pp.67-72
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• 2019

In this study, we investigate the non-reacting and reacting performance of single nozzle for post H class gas turbine by using commercial CFD tool, CONVERGE, based on adaptive mesh refinement. By varying swirl number and mixing length of base nozzle design. Through the numerical analysis, basic phenomena can be well described with respect to fuel concentration for non-reacting flow, temperature distribution, velocity vector and combustion outlet temperature distribution for reacting flow. However, there are rooms for improvements in model accuracy by comparing test results. Comparison between numerical analysis are planning for further study.

• Proceedings of the Korean Society of Computer Information Conference
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• 2023.07a
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• pp.675-678
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• 2023

본 연구는 팀기반학습을 활용한 교과목을 수강한 간호대학생 56명을 대상으로 동료평가와 학업성취도와의 관계에서 수업몰입의 매개효과를 검정하였다. 매개효과 분석은 PROCESS macro Program의 model 4를 부트스트래핑(bootstrapping)을 이용하여 검정하였다. 분석 결과는 첫째, 동료평가, 수업몰입과 학업성취도 간에 유의한 정적 상관이 있는 것으로 나타났다. 둘째, 수업몰입은 동료평가가 학업성취도에 미치는 영향을 부분매개 하는 것으로 확인되었다. 동료평가가 간호대학생을 위한 TBL 과정에서 수업몰입과 팀워크를 촉진하고 궁극적으로 학업성취도를 향상시키는 효과적인 도구가 될 수 있음을 시사하며, 교수자가 학생의 학습성과를 개선할 수 있는 보다 효과적인 교육 전략 및 개입을 개발하는 데 도움이 될 수 있다.

• Journal of the Korea Convergence Society
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• v.9 no.4
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• pp.331-339
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• 2018

The purpose of this study was to know the effects of flow in line dance class on happiness and continuous participation intention in elementary student. By using purposive sampling 271 questionnaires had been used for practical analysis. Collected data were put to frequency analysis, exploratory factor analysis reliability analysis, correlation analysis, and multiple regression analysis using the SPSS Win Ver. 22.0 program. The results of these analyses were as follows. First, the autotelic experience, the concentration, the sense of control and the sense of achievement which are the subordinate variables of the flow, were all found to have significant effects on the confidence, the autotelic experience, the sense of control and the sense of achievement which are the subordinate variables of the flow, were found to have significant effects on the self-realization, the autotelic experience, the concentration, and the sense of achievement which are the subordinate variables of the flow, were found to have significant effects on the enjoyment. Second, the autotelic experience, the concentration, and the sense of achievement which are the subordinate variables of the flow, were found to have significant effects on the continuous participation intention. Third, the confidence and the enjoyment, which are the subordinate variables of the happiness, were found to have significant effects on the continuous participation intention.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2011.11a
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• pp.807-812
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• 2011

Fuel-side cold-flow tests were performed on the technology demonstration model of a 75 ton-class liquid rocket engine combustion chamber for the first stage of the Korea space launch vehicle II. Pressure drop in the cooling channels of the combustion chamber was measured by changing fuel mass flow rate through a pressure regulating system. Pressure drop in each segment of the chamber could be obtained and a lot of pressure drop was caused by high flow velocity in the nozzle throat segment. The accuracy of a hydraulic analysis method for calculating a pressure loss in cooling channels could be verified by applying it to the cold-flow test conditions.

• Journal of the Korean Society of Propulsion Engineers
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• v.16 no.6
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• pp.56-61
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• 2012

Fuel-side cold-flow tests were performed on the technology demonstration model of a 75 ton-class liquid rocket engine combustion chamber for the first stage of the Korea space launch vehicle II. Pressure drop in the cooling channels of the combustion chamber was measured by changing fuel mass flow rate through a pressure regulating system. Pressure drop in each segment of the chamber could be obtained and a lot of pressure drop was caused by high flow velocity in the nozzle throat segment. The accuracy of a hydraulic analysis method for calculating a pressure loss in cooling channels could be verified by applying it to the cold-flow test conditions.

• The Journal of Internal Korean Medicine
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• v.21 no.3
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• pp.433-441
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• 2000

Objective : To analyze the effects of Yukmijihwang-tang, Taeksa-tang, Silbi-um on mesangial cell proliferation, fibronectin synthesis and MHC-class II expression. Methods : Laboratory studies were performed with the method of surface enzyme immunoassays or flow cytometry after addition of peripheral blood mononuclear cells(PBMC) supernatants treated with medications using the cultured human mesangial cells. Results : 1. Silbi-um produces more suppressive effect than control group and hydrocortisone group on the mesangial cell proliferation. In Yukmijihwang-tang, Taeksa-tang and Silbi-um, mesangial cell proliferation significantly decreased than in hydrocortisone group 2. In the 'without fetal bovine serum' study, Yukmijihwang-tang take more suppressive effect than Control group on the fibronectin synthesis. In the 'with fetal bovine serum' study, Yukmijihwang-tang, Taeksa-tang, Silbi-um all have suppressive effect, but it hasn' t any statistical significance. 3. Yukmijihwang-tang, Taeksa-tang, Silbi-um all have a suppressive effect on the MHC-class II expression. Conclusions : Herb medicine generally show a suppressive effect on the suppression of the mesangial cell proliferation, fibronectin synthesis and MHC-class II expression.

• The Journal of Internal Korean Medicine
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• v.26 no.2
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• pp.398-408
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• 2005

Objective: Graves' disease encompasses hyperthyroidism and diffused goiter associated with auto-antibodies to the thyroid stimulating hormone(TSH) receptors. In clinical environment, treatments of Graves' disease have many side effects such as recurrence and hypothyroidism. We've studied the effects of Sipyukmiyukieum on DNA synthesis, cAMP synthesis, and MHC-class II expression of FRTL-5 thyroid cells were studied. Methods: DNA synthesis was investigated by using BrdU staining and cAMP synthesis by ELISA kit, and expression of $interferon-{\gamma}$ activated MHC class II by Flow cytometer. Results: After introduction of Sipyukmiyukieum, significant inhibition of DNA synthesis. cAMP synthesis, and expression of $interferon-{\gamma}$ activated MHC class II of FRTL-5 thyroid cells was observed. Conclusions: Judging from these results, Sipyukmiyukieum has potential as a potent herbal treatment for inhibiting the enlargement of goiter, synthesis of abnormal thyroidal hormones, and autoimmuine responses of Graves' disease.

• Proceedings of the KIEE Conference
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• 1999.07d
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• pp.1876-1878
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• 1999

Developed was a 5kW-class polymer electrolyte membrane fuel cell(PEMFC) system comprised of fuel cell stack, fuel processing, thermal and water management subsystems and ancillary equipments. Several large single cells have been fabricated with different gas flow field patterns and paths, and the gas flow field pattern for the stack has been determined based on the single cell performance of thin film membrane electrode assembly (MEA). The PEMFC stack was consisted of 100 cells with an electrode area of $300cm^2$, having serpentine flow pattern. Fuel processing was developed including an autothermal methanol reformer and two preferential CO oxidation reactors. The fuel processing was combined to PEMFC operation system consisted of air compressor and thermal and water management subsystems. The PEMFC stack showed performance of 5kW under the supply of $H_2$ and air, but its performance was lowered to 3.5kW under the supply of reformed gas.

• Journal of the Korean Society of Propulsion Engineers
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• v.19 no.3
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• pp.89-95
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• 2015

Performance test was conducted for an oxidizer pump and a fuel pump for a 7 ton class rocket engine, by using water. The pumps were driven by an electric motor. The hydrodynamic performance and the suction performance were measured at flow ratio of the design and off-design conditions. Head-flow curve, efficiency-flow curve, and head-cavitation number curve were obtained. It is confirmed that the pumps can satisfy the design requirements of hydrodynamic performance in terms of the head and the efficiency. The pumps also satisfied the design requirements of suction performance.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2012.05a
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• pp.180-186
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• 2012

A water-flow test for acceptance verification is carried out for a nonimpinging-type injector prior to the design-performance verification of 70 N-class liquid-rocket engine under development. It is observed that there exist varying characteristics of atomization among the injector-orifices caused by a fabrication crudeness of orifice holes which can be judged from a microscopic standpoint. The flow shedding phenomenon and ruffle on the surface of liquid column (or droplet) could be caught from the instantaneous spray images.