• KIPS Transactions on Computer and Communication Systems
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• v.1 no.3
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• pp.143-150
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• 2012

A simulation methodology and corresponding program based on it is to be discussed for analyzing the effects of the networking operation of existing DHC system in connection with CHP system on-site. The practical simulation for arbitrary areas with various building compositions is carried out for the analysis of operational features in both systems, and the various aspects of thermal energy grids with connecting operation are highlighted through the detailed assessment of predicted results. The intrinsic operational features of CHP prime movers, gas engine, gas turbine etc., are effectively implemented by realizing the performance data, i.e. actual operation efficiency in the full and part loads range. For the sake of simplicity, a simple mathematical correlation model is proposed for simulating various aspects of change effectively on the existing DHC system side due to the connecting operation, instead of performing cycle simulations separately. The empirical correlations are developed using the hourly based annual operation data for a branch of the Korean District Heating Corporation (KDHC) and are implicit in relation between main operation parameters such as fuel consumption by use, heat and power production. In the simulation, a variety of system configurations are able to be considered according to any combination of the probable CHP prime-movers, absorption or turbo type cooling chillers of every kind and capacity. From the analysis of the thermal network operation simulations, it is found that the newly proposed methodology of mathematical correlation for modelling of the existing DHC system functions effectively in reflecting the operational variations due to thermal energy grids with connecting operation. The effects of intrinsic features of CHP prime-movers, e.g. the different ratio of heat and power production, various combinations of different types of chillers (i.e. absorption and turbo types) on the overall system operation are discussed in detail with the consideration of operation schemes and corresponding simulation algorithms.

• 대한공업교육학회지
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• v.37 no.1
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• pp.125-143
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• 2012

This study aimed to identify the effect of the instruction applied with a project method for the 'Making Model by Architecture' unit in vocational High schools on the improvement of the Key competences. With this aim, the study selected as an experimental group, control group third graders in two classroom in G vocational High Schools in Goyang, Gyeonggi-do. Aiming at the selected students in the experimental group and the control group, the study conducted a pre-test of their Key competences; thus, the study confirmed that there was no statistically significant difference. Then, the study offered a class applied with a project method to the experimental group, while offering a traditional instruction to the control group. After offering the class, the study undertook a post-test, and verified the effect. In order to prove the test result, the study carried out a Hest using the SPSSWIN 12.0 statistical program, while the significance level being ${\alpha}$<.05. The conclusions obtained from this study include the following. All the six selected areas including 'problem-solving skills', 'communication skills', 'resource utilization competence', 'mathematical competence', 'interpersonal management competence' and 'self-management competence', which were supposed to be appropriate for this study among the sub-areas of Key competences, were found to show significant differences between the experimental group applied with a project method and the control group as a result of the post-test of the two groups. In summarizing the above research results, the class using a project method for the 'Making Model by Architecture' unit was discovered to be effective for improving Key competences. In particular, it may be more effective learning method for enhancing six areas greatly relevant to the project method among various sub-areas of Key competences.

• Journal of The Korean Association of Information Education
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• v.11 no.3
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• pp.339-347
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• 2007

Along with developments of information and communication technologies, internet has spread not only all over the society, but also our everyday life deeply. Recently, requirements for e-learning using internet in the educational aspect have a great influence on the changes of school educations. Cyber Home Learning System, in particular, has been implemented throughout the nation for the purpose of reducing private expenditure for education and promoting substantial improvements in quality of public education. However, there have been exposed many problems with respect to quality of operations and managements of the system comparing to its quantitative growth, and so, at this point in time, researcher conducted analysis of actuality of perceptions of both elementary and middle school teachers with a focus on the case of S System in K province. To test this, total 278 participants were sampled from the elementary schools (139 teachers) and the middle schools (139 teachers) located in K province and were asked to complete a survey and the results therefrom were analyzed accordingly. Results from the analyses revealed that elementary school teachers responded more positively than other respondents in the most areas, including supply of a variety of learning contents of S System, quality of contents, and providing for helps insomuch as to complement school works, etcetera. In addition, researcher has found out that, to make the system become all the more efficient, it shall be required to establish a strategy in order to induce students' interest in the system, as well as to construct infrastructure for facilitating the use of computer. And that there are also needs for continuous supports from both the school and the education authority concerned, and for method of flexible operation of curriculum.

• Journal of Digital Convergence
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• v.13 no.4
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• pp.227-233
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• 2015

The recent health care is growing rapidly want to receive offers users a variety of medical services, can be exploited easily exposed to a third party information on the role of the patient's hospital staff (doctors, nurses, pharmacists, etc.) depending on the patient clearly may have to be classified. In this paper, in order to ensure safe use by third parties in the health care environment, classify the attributes of patient information and patient privacy protection technique using hierarchical multi-property rights proposed to classify information according to the role of patient hospital officials The. Hospital patients and to prevent the proposed method is represented by a mathematical model, the information (the data consumer, time, sensor, an object, duty, and the delegation circumstances, and so on) the privacy attribute of a patient from being exploited illegally patient information from a third party the prevention of the leakage of the privacy information of the patient in synchronization with the attribute information between the parties.

• Journal of the Korea Convergence Society
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• v.9 no.10
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• pp.159-165
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• 2018

This study was conducted to investigate the convergence effects of key vocational competency on career decision making in dental hygiene students. To this end, 196 students with an experience of clinical field training, who were enrolled in the department of dental hygiene in universities of Busan and Ulsan area. The collected data were analyzed by frequency analysis, correlation analysis and linear regression analysis using SPSS 24.0 program. The subjects' awareness level of key vocational competency was 3.38 points, while that of career decision making was 3.30 points. Among the sub-factors of key vocational competency, the awareness level of professional ethics was 3.46 points, which was the highest. As factors of key vocational competency affecting career decision making, interpersonal skills(p<0.01), skills for understanding groups(p<0.01), resource management skills(p<0.01), self-development skills(p<0.05), problem-solving skills(p<0.05), and mathematical skills(p<0.05) were found to be significant. It is necessary to make student individual, departmental, and university level convergence efforts and to develop curriculum so that dental hygiene education can help students equip with the key vocational competency as well as major competency.

• Journal of The Korean Association For Science Education
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• v.18 no.4
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• pp.571-587
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• 1998

This paper reviews and analyzes the conceptions of science achievement in the United States and Korean reform documents, including those on science content standards(NSES, Porject 2061, and Korean 7th science curriculum), performance standards(New Standards, and Survey of Ecucational Achievement in Korean Elementary and Secondary Schools), and large-scale assessment framworks(1996 NAEP, TIMSS, The National Assessment of Science Inqury Abilities, The National Assessment of Science Knowledge, and The National Assessment of Affective Characteristics related to Science). The analysis of these documents indicates that there is an overall agreement on the conceptions of science achievement. The documents consistently emphasize high achievement in terms of knowledge and abilities in scientific, technological, social, and environmental perspectives. In addition, these documents define science achievement at different developmental levels and at certain depths of knowledge and abilities for all students. Despite the overall agreement, there are also noticeable variations among the documents because of different contexts and purposes. There is a difference in the balance of representations or emphases among content and process standards in the documents. The conceptions of science achievement in the Korean documents are not as comprehensive or inclusive as those in the United States documents. There is no representation of the mathematical world, the nature of science, historical perspectives, unifying concepts, or scientific communication. From these results, two conclusions are drawn. First, more coherent conceptions of science achievement are needed for common understanding among educators and the public. Second, efforts are needed for developing more comprehensive and inclusive conceptions of science achievement in Korea.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.11 no.2
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• pp.422-429
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• 2007

Location awareness is one of the key functionalities to build an U-city. Recently, many of works of the location-aware systems are emerging to commercially apply to on-going large-scale apartment complex based on U-city. As dwellers or cars being attached with active tags are moving in the U-city complex, the active tags periodically broadcast their own identifiers and receivers fixed along the street or in building use those information to calculate location of them. There are several issues to be considered for such an environment. The first is that the number of active tags operating in the same region are large as much as tens of thousands, and the second is that the active tags should be alive without change of batteries more than a year, hence low power consumption is very important. In this paper we propose i) a new architecture for location-aware system considering such issues, ii) technical issues to implement it using active tags, and iii) a mathematical analytic model to investigate overall performance and verify it by comparing with actual experimental results. Through the analysis we can show the theoretical boundary of the lowest packet loss rate and the maximum number of tags with acceptable performance for the systems based on active tags. The results can be applied to practical design of location-based systems of U-City projects.

• Journal of the Korean earth science society
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• v.40 no.5
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• pp.518-537
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• 2019

This study examined the implications of a place-based earth science program integrated with Mathematics. 11 pre-service earth science teachers and 22 middle school students participated in the service education activities of earth science for 30 hours focusing on the measurement of the earth's size through earth science experiments as part of the middle school curriculum. In order to minimize errors that may occur during the earth's size measurement experiments using Eratosthenes's shadows length method of the ancient Greek era, the actual data were collected after triangulation ratios were conducted in the locations of two middle schools: one in remote metropolitan and the other in rural area. The two schools' students shared the final estimate result. Through this process, they learned the mathematical method to express the actual data effectively. Participants, experienced the importance and difficulty of the repetitive and accurate data acquisition process, and also discussed the causes of errors included in the final results. It implies that a Place-Based Earth Science Program activity can contribute to students' increased-understanding of the characteristics of earth science inquiry and to developing their problem solving skills, thinking ability, and communication skills as well, which are commonly emphasized in science and mathematics in the 2015 reunion curriculum. It is expected that a place-based science program can provide a foundation for developing an integrated curriculum of mathematics and science.

• Journal of Science Education
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• v.46 no.1
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• pp.121-149
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• 2022

Descriptive assessment is a meaningful assessment method in relation to problem solving ability, reasoning ability, and communication ability as emphasized in mathematics curriculum. In Korea, as performance assessment has been emphasized since the 7th mathematics curriculum, descriptive assessment is being conducted as a method of performance assessment in schools. However, descriptive assessment has not been introduced in the university scholastic ability test for various reasons. Considering that descriptive assessment is emphasized in the mathematics classroom and has sufficient educational value, a serious discussion on the implementation of descriptive assessment in the university scholastic ability test will be necessary. In this study, we analyzed the descriptive assessment of Russia's unified state examination (USE) in the mathematics, which corresponds to Korea's university scholastic ability test. Through a literature review, we investigated how mathematics examination problems were structured in the USE and which mathematical abilities were required for the examination. In particular, the outer structure of the problems was analyzed focusing on the mathematics problems of the USE 2021, and the scoring method of the descriptive problems was also analyzed. The results of this study are expected to provide a variety of information on the possibility of introducing descriptive assessment in the Korean university scholastic ability tests.

• Journal of The Korean Association For Science Education
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• v.43 no.2
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• pp.87-98
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• 2023

In this study, we investigated the change in science core competency perception of high school students and the reason for change when science inquiry classes were conducted using eight 'skills' of the 2015 revised science curriculum. Fifteen first-year high school students in Jeollanam-do participated in the science inquiry class of this study, and the class was conducted for 20 hours (5 hours a day for four days). The inquiry activities used in the class consisted of four activity stages (research problems, research methods, research results, and conclusions) and each stage was constructed to include at least one 'skill (Problem Recognition, Model Development and Use, Inquiry Design and Performance, Data Collection, Analysis and Interpretation, Mathematical Thinking and Computer Application, Conclusion and Evaluation, Evidence-based Discussion and Demonstration, and Communication)'. As a result of the study, students' perception of the five science core competencies increased statistically significantly at the significance level of 0.01 through inquiry classes and more than 93% of students recognized that their science core competencies improved through the classes. However, since the class of this study was conducted for a small number of students, it is difficult to generalize the effect of the class, and so it is necessary to conduct a quantitative study for many students.