• Journal of the Microelectronics and Packaging Society
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• v.29 no.2
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• pp.107-112
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• 2022

In this study, a silver paste capable of UV curing without using any solvent was developed. The viscosity and viscoelasticity of the silver paste developed as a solvent-free type were measured. And after printing the pattern by screen printing, an electrode coating film was formed by UV curing. Conductivity, pencil hardness, and adhesive force of the formed electrode coating film were evaluated. Finally, the curing characteristics of the electrode coating film were evaluated by TGA and FT-IR. Summarizing these results, in terms of conductivity, adhesion, and curing characteristics, it was found that Paste (4), that is, silver paste obtained by mixing 1.2 ㎛ spherical silver powder and 50 nm silver powder at 72:8% had the best physical properties.

• Nuclear Engineering and Technology
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• v.52 no.12
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• pp.2760-2770
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• 2020

A model for calculation of fuel temperature profile using binary gas mixture of Helium and Xenon for gap gas conductance is proposed here. In this model, the temperature profile of a fuel pencil from fuel centreline to fuel surface has been calculated by taking into account the dilution of Helium gas filled during fuel manufacturing due to accumulation of fission gas Xenon. In this model an explicit calculation of gap gas conductance of binary gas mixture of Helium and Xenon has been carried out. A computer code Fuel Characteristics Calculator (FCCAL) is developed for the model. The phenomena modelled by FCCAL takes into account heat conduction through the fuel pellet, heat transfer from pellet surface to the cladding through the gap gas and heat transfer from cladding to coolant. The binary noble gas mixture model used in FCCAL is an improvement over the parametric model of Lassmann and Pazdera. The results obtained from the code FCCAL is used for fuel temperature calculation in 3-D neutron diffusion solver for the coolant outlet temperature of the core at steady operation at full power. It is found that there is an improvement in calculation time without compromising accuracy with FCCAL.

• Safety and Health at Work
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• v.14 no.1
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• pp.10-16
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• 2023

Whilst Ecological momentary assessment (EMA) can provide important insights over time and across contexts among rotation workers whose work periods alternate with leave at home, it can also be challenging to implement in the resources and construction sectors. This review aimed to provide a summary of the methodological characteristics of EMA studies assessing health outcomes and related behaviors in rotation workers. Systematic searches in PubMed, Medline, EMBASE, CINAHL, PsycINFO, and Scopus were done to include 23 studies using EMA methods in assessing health-related outcomes and behaviors. EMA designs included daily diary: assessments once per day typically fixed at the end of day (47.8%), within day fixed interval time-based design: assessments on multiple times per day at certain times of day (17.4%) and combination of both designs (34.8%). Studies employed paper and pencil diaries (73.9%) and one or more electronic methods (60.9%): wrist-worn actigraphy device (52.2%) and online-based diaries (26.1%) for data collection. Most of the studies (91.3%) did not report prompting -EMAs by schedule alerts or compliance. Daily diary and within day fixed interval dairies designs are common, with the increasing use of electronic EMA delivery techniques. It is unclear how well participants adhere to assessment schedules, as these are inadequately reported. Researchers should report compliance-related information.

• Journal of The Korean Association For Science Education
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• v.28 no.7
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• pp.713-723
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• 2008

Science teaching-anxiety and science teaching-efficacy are influential factors in teachers' teaching practices and behaviors. In order to encourage elementary teachers to do better teaching practice, this study identified factors that have caused teachers' science teaching-anxiety, developed an instrument measuring science teaching-anxiety, and investigated the relationship between science teaching-anxiety and science teaching-efficacy. In addition, we attempted to suggest practical implications to enhance teachers' confidence in science teaching. The guiding research questions were 1) which factors affect science teaching-anxiety level of the preservice elementary teachers, and 2) how each factor of science teaching-anxiety is related to science teaching-efficacy. The subjects were 133 Korean preservice elementary teachers (57.1% were female) in a large city. The data sources included teachers' responses to three paper and pencil questionnaires: State-Trait Anxiety Inventory (STAI), Science Teaching-Anxiety Questionnaire (STAQ), and Science Teaching Efficacy Belief Instrument (STEBI-B). To clarify the science teaching-anxiety, we specified it into six factors: trait anxiety about nature of science and science teaching, state anxiety about instruction, science activities, student assessment, and professional responsibilities. The results indicated three significant aspects of science teaching anxiety and efficacy. First, their level of anxiety about professional responsibility and science teaching was relatively high among six factors. Second, there was a negative correlation between science teaching-anxiety and science teaching-efficacy. Third, trait anxiety about science teaching is the most influential factor for science teaching-efficacy while state anxiety about instruction and professional responsibilities were followed.

• Journal of The Korean Association For Science Education
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• v.27 no.6
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• pp.519-528
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• 2007

Although science continues to be a key subject in the education of the majority of young people throughout the world, it is becoming increasingly clear that school science is failing to win the hearts and minds of many of today's younger generation. Researchers have begun to look at ways in which the learning that takes place in museums, science centres and other informal settings can add value to science learning in schools. Four case studies are used to illustrate the potential afforded by informal contexts to research aspects of science learning. The case studies involve: the European Union PENCIL (Permanent European Resource Centre for Informal Learning) project (a network of 14 museums and science centres working with schools to enhance learning in maths and science); a large natural history museum in England; the Tate Modernart gallery in London, and the Outdoor Classroom Action Research Project which involved researchers working in school grounds, field centres and farms. The range of research questions that were asked are examined as are the methodological approaches taken and the methods used to collect and analyse data. Lessons learned from the studies about research in the informal contexts are discussed critically.

• Journal of the Korean School Mathematics Society
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• v.10 no.2
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• pp.263-288
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• 2007

The purpose of this study is to search the effective teaching-learning program by considering how affect on formation of the process-object perspective of linear function using Excel. In this study we analyzed function units in textbook and examined how Excel affect on the formation of the process-object perspective of linear function. Teaching experiment was based on qualitative case study and performed for five classes with five 8th graders. Data were gathered through observations, audio-taped interviews, video recording of the students 'work, students' worksheets, and detailed field notes. Findings indicate that exploration learning environment using Excel could supplement paper-and-pencil environment. We found that intuitive, dynamic, explorative, feedback skills via Excel can play the role of scaffolding supporting formation of process perspective object perspective of linear function.

• Journal of Adhesion and Interface
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• v.7 no.1
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• pp.10-15
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• 2006

The hard coatings on the polycarbonate plate were performed with the object of substitution the glass in the car to the polycarbonate plate. In this research, [3-(methacryloyloxy)propyl]trimethoxysilane were used to prepare the coatings by sol-gel process. Butanol was used as a solvent, HCl was used as a catalyst, and AIBN was used as an initiator. Polycarbonate plate was pretreated with PMMA, and final heating of the coating was done at $130^{\circ}C$ for 6 h. Pencil hardness of the coating was 2 H, abrasion resistance and adhesion of the coating were excellent.

• The Journal of Korean Association of Computer Education
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• v.17 no.2
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• pp.39-51
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• 2014

In high-stakes tests for large groups, the efficiency with which students' responses are distributed to raters and how systematic scoring procedures are managed is important to the overall success of the testing program. In the scoring of constructed response items, it is important to understand whether the raters themselves are making consistent judgments on the responses, and whether these judgments are similar across all raters in order to establish measures of rater reliability. The purpose of this study was to design, develop and carry out a pilot test of an online scoring system for constructed response items administered in a paper-and-pencil test to large groups, and to verify the system's reliability. In this study, we show that this online system provided information on the scoring process of individual raters, including intra-rater and inter-rater consistency, compared to conventional scoring methods. We found this system to be especially effective for obtaining reliable and valid scores for constructed response items.

• The Journal of Korean Association of Computer Education
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• v.11 no.1
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• pp.1-10
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• 2008

Web-based Assessment System is needed for Process-Oriented Evaluation to integrate instructions into evaluation frequently in Informatics Education, and considered usability for supporting teachers to test more conveniently. First of all, we analyzed usability of traditional Web-based Assessment System, and proposed PBA(Paper-Based Assessment) model by extracting usability features of paper-pencil assessment in off-line. The evaluation system based on the PBA model controls the whole processes of tests; before-test, under-test, after-test. Especially, the system readily can change the target class, and control access to the test page during each step. Thus we can get high credibility about the test results. Moreover, students can login to the paper easily by using their grade, class, number and name. Finally, we designed and implemented the Web-based Assessment System for Informatics education on the basis of PBA model; PAS(PBA-based Assessment System).

• Nuclear Engineering and Technology
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• v.52 no.9
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• pp.2064-2071
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• 2020

For proton pencil beam scanning (PBS) technology, the accuracy of the dose distribution in a patient is sensitive to the properties of the incident beam. However, mechanical deformation of the proton therapy facility may occur, and this could be an important factor affecting the proton dose distribution in patients. In this paper, we investigated the effect of deformation on an SC200 proton facility's beam isocenter properties. First, mechanical deformation of the PBS nozzle, L-shape plate, and gantry were simulated using a Finite Element code, ANSYS. Then, the impact of the mechanical deformation on the beam's isocenter properties was evaluated using empirical formulas. In addition, we considered the simplest case that could affect the properties of the incident beam (i.e. if only the bending magnet (BG3) has an error in its mounting alignment), and the effect of the beam optics offset on the isocenter characteristics was evaluated. The results showed that the deformation of the beam position in the X and Y direction was less than 0.27 mm, which meets the structural design requirements. Compared to the mechanical deformation of the L-shape plate, the deformation of the gantry had more influence on the beam's isocenter properties. When the error in the mounting alignment of the BG3 is equal to or more than 0.3 mm, the beam deformation at the isocenter exceeds the maximum accepted deformation limits. Generally speaking, for the current design of the SC200 scanning beam delivery system, the effects of mechanical deformation meet the maximum accepted beam deformation limits. In order to further study the effect of the incident beam optics on the isocenter properties, a fine-scale Monte Carlo model including factors relating to the PBS nozzle and the BG3 should be developed in future research.