• Journal of the Korean School Mathematics Society
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• v.21 no.4
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• pp.303-326
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• 2018

Fraction has difficulties in learning because of the diversity of meanings, the ways of presenting contents and teaching methods in elementary school mathematics. Therefore, the various strategies of teaching of fraction concept is proposed as an alternative. The problem of equal sharing problem is that children can experience the concept of fractions naturally in the context of everyday distribution. Even before learning formal fractions, children can solve them in various ways based on their own experiences. The purpose of this study is to investigate the degree of problem solving and problem solving strategies for children in 2nd, 4th, and 6th grades in elementary school. As a result of the research, the percentage of correct answers increased as the grade increased, but the grade levels showed a difference depending on the numbers given to the problems. Also, there were differences in the problem solving strategies according to the grade levels. Also, according to the numbers presented in the problem, the percentage of correct answers was high in items that were easy to divide, and the percentage of correct answers was low in items that were difficult to divide. When children solved the problems, they were affected by the strategies they could use immediately according to the number presented in the problem, and their learning experiences were also affected.

• The Journal of the Korea Contents Association
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• v.9 no.12
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• pp.339-347
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• 2009

Purpose : This study was to investigate the influence of heart rate and coronary calcification on diagnostic accuracy of 64-slice multidetector CT(MDCT) in coronary artery disease. Methods : 178 patients(84 men, 94 women) undergoing cardiac CT were included in this study. 3 coronary arteries(LAD, LCX, RCA) were assessed the presence of significant stenosis($\geq50%$) and the results compared with those of coronary angiography. Results : On a patient-based analysis, the diagnostic accuracy of 64-slice MDCT was 96.6%. The diagnostic accuracy on left anterior descending, left circumflex, right coronary artery were 86.5%, 84.3%, 92.1% respectively. Body mass index and blood pressure were not influenced on diagnostic accuracy of 64-slice MDCT. In less than 60/min of heart rate, accuracy was 90.1% and $\kappa$ value was 0.78. While in more than 70/min of heart rate, accuracy was 75.8% and $\kappa$ value was 0.52. In less than 100 of coronary calcification, accuracy was 91.3% and $\kappa$ value was 0.81. While in more than 400, accuracy was 68.6% and $\kappa$ value was 0.33. Conclusion : 64-slice MDCT shows similar diagnostic accuracy as coronary angiography. But in the context of more than 70/min of heart rate and 400 of coronary calcification, diagnostic accuracy was decreased. So there needs to identify heart rate and coronary calcification in cardiac CT, and if heart rate shows more than 70/min, use beta-blocker to regulate it.

• Journal of Science and Technology Studies
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• v.18 no.2
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• pp.43-93
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• 2018

The concept of citizen science(CS) is defined as "scientific work carried out by citizens." Here, 'citizen' means someone who has knowledge of everyday life, regardless of whether they have formal expertise in a related field. This definition may encompass scientists, as many scientists participate in scientific democracy and use their expertise in a citizen-oriented manner. That work is derived from their citizenship, so their scientific work is CS. CS in Korea has expanded from the Korea Pollution Research Institute, which was founded in 1982, to the Center for Democracy in Science & Technology, which was founded in 1997. Furthermore, in recent years, government agencies have started using CS approach. In this paper, I introduce Korean CS and examine its accomplishments and difficulties through eight cases. I show that Korea's CS activities have made a significant impact on Korean society and the experience of these activities has implications for the future directions of CS. I do so by examining four modes of CS and explore practical messages for more varied roles of CS. Until now CS has been mainly considered in the context of "CS as education" or "CS as movement" in Korea. However, governance and the platform mode of social decision-making or research, though still rare, have recently emerged as additional CS activities. Although it cannot be said with certainty that CS is better, it is undoubtedly better the more varieties of its modes coexist. The four types of CS will contribute individually or complementarily to social learning. Thus, because of its distinctive potential, CS is not exhausted by the supplementary concept of science.

• Journal of Computing Science and Engineering
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• v.6 no.1
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• pp.40-50
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• 2012

Increase in the number of older people due to demographic changes poses great challenges to the social healthcare systems both in the Western and as well as in the Eastern countries. Support for older people by formal care givers leads to enormous temporal and personal efforts. Therefore, one of the most important goals is to increase the efficiency and effectiveness of today's care. This can be achieved by the use of assistive technologies. These technologies are able to increase the safety of patients or to reduce the time needed for tasks that do not relate to direct interaction between the care giver and the patient. Motivated by this goal, this contribution focuses on applications of acoustic technologies to support users and care givers in ambient assisted living (AAL) scenarios. Acoustic sensors are small, unobtrusive and can be added to already existing care or living environments easily. The information gathered by the acoustic sensors can be analyzed to calculate the position of the user by localization and the context by detection and classification of acoustic events in the captured acoustic signal. By doing this, possibly dangerous situations like falls, screams or an increased amount of coughs can be detected and appropriate actions can be initialized by an intelligent autonomous system for the acoustic monitoring of older persons. The proposed system is able to reduce the false alarm rate compared to other existing and commercially available approaches that basically rely only on the acoustic level. This is due to the fact that it explicitly distinguishes between the various acoustic events and provides information on the type of emergency that has taken place. Furthermore, the position of the acoustic event can be determined as contextual information by the system that uses only the acoustic signal. By this, the position of the user is known even if she or he does not wear a localization device such as a radio-frequency identification (RFID) tag.

• Korean Journal of Social Welfare
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• v.62 no.1
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• pp.367-389
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• 2010

The purpose of this study is to find out perception types of service practitioners working for intellectually disabled adults on the relationships with their service users who use residential and domiciliary care services. For this purpose, this study adopted two research methods: Q-methodology and survey. This study found out three major types of practitioners' perception on the relationships with their service users. The first is the type of superficial orientation for equal relationship. The second is the type of reflective recognition on the driven relationships by practitioners. The third is that of compassionate at the advocacy for service users. In the result of survey in which respondents are practitioners working in residential care homes, small group homes and community service centers, 48.2% of respondents show the first type, 40.5% the second, 11.1% the third. Recently, in the area of personal social service for the intellectually disabled people, the importance of service users' participation and self-determination in the process of service provision is gaining higher concerns. In this context, making change on relationships between service workers and users is raised as important issue. In this environment, the results of this study could be useful to develop equal and supporting relationships.

• The KIPS Transactions:PartD
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• v.11D no.2
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• pp.325-338
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• 2004

A data warehouse stores information that is collected from multiple, heterogeneous information sources for the purpose of complex querying and analysis. Information in the warehouse is typically stored In the form of materialized views, which represent pre-computed portions of frequently asked queries. One of the most important tasks of designing a warehouse is the selection of materialized views to be maintained in the warehouse. The goal is to select a set of views so that the total query response time over all queries can be minimized while a limited amount of time for maintaining the views is given(maintenance-cost view selection problem). In this paper, we propose an efficient solution to the maintenance-cost view selection problem using a genetic algorithm for computing a near-optimal set of views. Specifically, we explore the maintenance-cost view selection problem in the context of OR view graphs. We show that our approach represents a dramatic improvement in terms of time complexity over existing search-based approaches that use heuristics. Our analysis shows that the algorithm consistently yields a solution that only has an additional 10% of query cost of over the optimal query cost while at the same time exhibits an impressive performance of only a linear increase in execution time. We have implemented a prototype version of our algorithm that is used to evaluate our approach.

• Journal of the Korea Society of Computer and Information
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• v.14 no.10
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• pp.241-249
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• 2009

Recently, a number of researches related to video annotation and representation have been proposed to analyze video for searching and abstraction. In this paper, we have presented a method to provide the picture elements of conversational participants in video and the enhanced representation of the characters using those elements, collectively called Character-net. Because conversational participants are decided as characters detected in a script holding time, the previous Character-net suffers serious limitation that some listeners could not be detected as the participants. The participants who complete the story in video are very important factor to understand the context of the conversation. The picture elements for detecting the conversational participants consist of six elements as follows: subtitle, scene, the order of appearance, characters' eyes, patterns, and lip motion. In this paper, we present how to use those elements for detecting conversational participants and how to improve the representation of the Character-net. We can detect the conversational participants accurately when the proposed elements combine together and satisfy the special conditions. The experimental evaluation shows that the proposed method brings significant advantages in terms of both improving the detection of the conversational participants and enhancing the representation of Character-net.

• Journal of Korean Library and Information Science Society
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• v.54 no.4
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• pp.359-392
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• 2023

Digital citizenship includes an evolving set of knowledge and skills related to effectively and ethically using technology, especially when interacting with other people, information, and media in the online context. As public libraries have long provided access to and training with a variety of technologies, this study explores how digital citizenship has been covered in public library programming to identify potential trends and best practices. A purposive sampling of public library recipients of the American Library Association (ALA) and Information Today Inc.'s Library of the Future Award over the past 11 years (2013-2023) identified 7 case libraries to review. The titles and descriptions of 337 relevant library programs for audiences of school-aged children (5 years old and up) to seniors were collected for a 2-month period from each library's website and analyzed using Ribble & Parks (2019) 9 elements of digital citizenship. The findings suggest that programming related to digital citizenship most often addresses themes connected to digital access and digital fluency through coverage of topics related to computer and technology use. Based on themes and examples from the findings, public libraries are encouraged to expand upon existing programs to integrate all elements of digital citizenship, strive for inclusive and accessible digital citizenship education for all ages, and leverage resources and expertise from relevant stakeholders and community partnerships.

• Journal of Intelligence and Information Systems
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• v.14 no.2
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• pp.179-192
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• 2008

This case study shows constructing the knowledge-based system using a rule-based approach for detecting illegal transactions regarding money laundering in the Korea Financial Intelligence Unit (KoFIU). To better manage the explosive increment of low risk suspicious transactions reporting from financial institutions, the adoption of a knowledge-based system in the KoFIU is essential. Also since different types of information from various organizations are converged into the KoFIU, constructing a knowledge-based system for practical use and data management regarding money laundering is definitely required. The success of the financial information system largely depends on how well we can build the knowledge-base for the context. Therefore we designed and constructed the knowledge-based system for anti-money laundering by committing domain experts of each specific financial industry co-worked with a knowledge engineer. The outcome of the knowledge base implementation, measured by the empirical ratio of Suspicious Transaction Reports (STRs) reported to law enforcements, shows that the knowledge-based system is filtering STRs in the primary analysis step efficiently, and so has made great contribution to improve efficiency and effectiveness of the analysis process. It can be said that establishing the foundation of the knowledge base under the entire framework of the knowledge-based system for consideration of knowledge creation and management is indeed valuable.

• Management & Information Systems Review
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• v.29 no.4
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• pp.23-44
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• 2010

This study examines the value-relevance of accruals and discretionary accruals. Also, by examining the effects of the corporate life-cycle on these relationship, this study is able to provide evidence of the value-relevance of accruals and discretionary accruals measures in the economic context of life-cycle theory. This study uses results based on life-cycle classification methods developed by Anthony and Ramesh(1992), adjust Jones model and Dechow Dechev(2002) model. We classify firms using individuals variables(sales growth, capital expenditure growth, employee growth) and then use a composite score obtained from all variables for classification. Our sample consists of 272 firms listed in the Korean Stock Exchange during 14 years(1996-2009). Our final sample for regression variables consists of 2,448 firm-year observations. This evidence implies that the value-relevance of accruals and discretionary accruals in the growth and mature stage can have positive impact on the price but in the decline the value-relevance of accruals and discretionary accruals can have negative impact on the price. The results mean that discretionary accruals communicate managements' private information in the growth stage, but. earnings management in the decline stage. The results of this study suggest that corporate life cycle stages influence the value-relevance of accruals and discretionary accruals measures.