• Proceedings of the Korean Vacuum Society Conference
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• 2012.02a
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• pp.580-580
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• 2012

Heterostructures has unique and important properties, which may be helpful for finding many potential applications in the field of electronic, thermoelectric, and optoelectronic devices. We synthesized CdTe/Te core-shell heterostructures by vapor-solid process at low temperatures using a quartz tube furnace. Two step vapor-solid processes were employed. First, various tellurium structures such as nanowires, nanorods, nanoneedles, microtubes and microrods were synthesized under various deposition conditions. These tellurium nanostructures were then used as substrates in the second step to synthesize the CdTe/Te core-shell heterostructures. Using this method, various sizes, shapes and types of CdTe/Te core-shell structures were fabricated under a range of conditions. These structures were analysed by scanning electron microscopy, high resolution transmission electron microscopy, and energy dispersive x-ray spectroscopy. The vapor phase process at low temperatures appears to be an efficient method for producing a variety of Cd/Te hetero-nanostructures. In addition, the hetero-nanostructures can be tailored to the needs of specific applications by deliberately controlling the synthetic parameters.

• International journal of advanced smart convergence
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• v.11 no.1
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• pp.117-126
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• 2022

Corporate social responsibility (CSR) is the basic strategy for enterprises to obtain competitive advantages, and reflects the most basic value orientation and development concept of enterprises. The purpose of this study is to explore the relationship between corporate culture, innovation ability and core competitiveness of enterprises from the perspective of corporate social responsibility, and to establish a model and analyze the survey data of 32 agricultural science and technology enterprises in Tianjin by using SPSS23.0. As a result of the study, we found that corporate social responsibility (Ethical responsibility, Philanthropic responsibility) has a significant positive impact on corporate culture and innovation ability, corporate culture has a significant positive impact on innovation ability and corporate core competitiveness, and innovation ability has a significant positive impact on corporate core competitiveness. Therefore, it is suggested that agricultural science and technology enterprises should fulfill their social responsibilities, form a unique corporate culture, serve agriculture with science and technology, and constantly improve the ability of agricultural science and technology innovation, so as to enhance the core competitiveness of enterprises.

• International Journal of Fluid Machinery and Systems
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• v.9 no.4
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• pp.325-331
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• 2016

A bathtub vortex above the outlet of a rotating barrel is simulated. By analyzing the Ekman layer theory, it can be found that the main flow circulation is inversely proportional to the thickness of Ekman layer. The thicker the Ekman boundary layer, the weaker the rotational strength and the shorter of the length of gas core is. According to this law, models of barriers with rods of different heights are established. The reduction of air-core length in this air entrainment vortex and weakening the strength of rotation field were achieved.

• Journal of The Korean Association For Science Education
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• v.41 no.2
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• pp.171-181
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• 2021

The purpose of the study is to explore the personal experiences and efforts of science teachers, who have worked in science core schools over the years, in order to evaluate the educational effects and implications of science core school policies. To achieve this purpose, we conducted semi-structured interviews with twelve individual science teachers who have operated programs and curriculum at science core schools. The results provided three case studies presenting how the teachers operated curriculum and how they perceived the benefits of science core schools and identified some commonalities in their experiences and perceptions through cross-case discussions. Three teachers in case studies presented different teaching orientations for science core schools, but they positively perceived its benefits and were very satisfied with the school environment and financial supports from government even though they had more burdens on work. In cross-case analysis among 12 teachers, the teachers commonly presented their passion and enthusiasm for organizing and implementing various extra-curriculum science activities. They believed that such efforts contributed to encouraging their students to consider their careers in science and engineering fields in college. And the differentiated school program has increased reputation and preference for the school from local parents and students. In addition, they felt that these efforts brought their own growth and professional development as science teachers.

• 한국생물공학회:학술대회논문집
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• 2005.10a
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• pp.642-643
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• 2005

• Journal of the Korean Society of Earth Science Education
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• v.16 no.3
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• pp.351-362
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• 2023

This study aimed to identify structural relationships among variables by examining the direct and indirect effects of cognitive factors such as self-regulated learning strategy and definitional factors such as attitude toward science and scientific self-efficacy on science core competency in middle school students. To this end, the researcher examined the causal relationships among the variables using data from 438 students in all grades at S middle school in a metropolitan city. The results showed that middle school students' self-regulated learning strategy, attitude toward science, and scientific self-efficacy had a direct effect on science core competency, and that self-regulated learning strategy had a direct effect on attitude toward science and scientific self-efficacy. In addition, middle school students' self-regulated learning strategy had an indirect effect on science core competency through attitude toward science and scientific self-efficacy. Therefore, it is necessary to educate students from a comprehensive perspective that considers cognitive factors such as self-regulated learning strategy and defining factors such as attitude toward science and scientific self-efficacy in order to foster science core competency in middle school students.

• 한국정보디스플레이학회:학술대회논문집
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• 2004.08a
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• pp.239-242
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• 2004

This paper presents a novel contrast enhance algorithm for images displayed with bright environment light. This algorithm is designed to preserve local contrast based on the luminance ratio of the pixel to its local surround in attention. This algorithm improves image quality of projectors in a bright room.

• Geomechanics and Engineering
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• v.10 no.6
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• pp.709-726
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• 2016

Corrugated-core sandwich panels are prevalent for many applications in industries. The researches performed with the aim of optimization of such structures in the literature have considered a deterministic approach. However, it is believed that deterministic optimum points may lead to high-risk designs instead of optimum ones. In this paper, an effort has been made to provide a reliable and robust design of corrugated-core sandwich structures through stochastic and probabilistic multi-objective optimization approach. The optimization is performed using a coupling between genetic algorithm (GA), Monte Carlo simulation (MCS) and finite element method (FEM). To this aim, Prob. Design module in ANSYS is employed and using a coupling between optimization codes in MATLAB and ANSYS, a connection has been made between numerical results and optimization process. Results in both cases of deterministic and probabilistic multi-objective optimizations are illustrated and compared together to gain a better understanding of the best sandwich panel design by taking into account reliability and robustness. Comparison of results with a similar deterministic optimization study demonstrated better reliability and robustness of optimum point of this study.

• Nuclear Engineering and Technology
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• v.55 no.2
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• pp.452-459
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• 2023

The core power control is an important issue for the study of dynamic characteristics in China initiative accelerator driven subcritical system (CiADS), which has direct impact on the control strategy and safety analysis process. The CiADS is an experimental facility that is only controlled by the proton beam intensity without considering the control rods in the current engineering design stage. In order to get the optimized operation scheme with the stable and reliable features, the variation of beam intensity using the continuous and periodic control approaches has been adopted, and the change of collimator and the adjusting of duty ratio have been proposed in the power control process. Considering the neutronics and the thermal-hydraulics characteristics in CiADS, the physical model for the core power control has been established by means of the point reactor kinetics method and the lumped parameter method. Moreover, the multi-inputs single-output (MISO) logical structure for the power control process has been constructed using proportional integral derivative (PID) controller, and the meta-heuristic algorithm has been employed to obtain the global optimized parameters for the stable running mode without producing large perturbations. Finally, the verification and validation of the control method have been tested based on the reference scenarios in considering the disturbances of spallation neutron source and inlet temperature respectively, where all the numerical results reveal that the optimization method has satisfactory performance in the CiADS core power control scenarios.

• Journal of Engineering Education Research
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• v.23 no.5
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• pp.76-85
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• 2020

The purpose of this study was to develop and validate a measurement scale of core competencies for one Institute of Science & Technology's students in South Korea. Based on the school's core value and mission, items were developed through document analysis, faculty survey, and experts' review. Initial sets of items were administered to students and results were analyzed to finalize the items for the scale, which consists of 4 core competencies (Creativity, Challenge, Collaboration, and Care) and 12 sub-competencies. Through reliability analysis and exploratory factor analysis, 56 items were selected. For a validity test, confirmatory factor analysis was conducted. Results suggest that the measurement scale is reliable and valid in measuring core competencies of students in an Institute of Science & Technology.