• Journal of KIISE:Computer Systems and Theory
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• v.27 no.1
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• pp.61-67
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• 2000

Digital controllers found in many industrial real-time systems consist of a number of interacting periodic tasks. To sustain the required control quality, these tasks possess the maximum activation periods as performance constraints. An essential step in developing a real-time system is thus to assign each of these tasks a constant period such that the maximum activation requirements are met while the system utilization is minimized [1]. Given a task graph design allowing producer/consumer relationships among tasks [2], resource demands of tasks, and range constraints on periods, the period assignment problem falls into a class of nonlinear optimization problems. This paper proposes a ploynomial time approximation algorithm which produces a solution whose utilization does not exceed twice the optimal utilization. Our experimental analysis shows that the proposed algorithm finds solutions which are very close to the optimal ones in most cases of practical interest.

• Journal of the Ergonomics Society of Korea
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• v.34 no.2
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• pp.191-198
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• 2015

Objective: As a cue for desired mood, we attempted to identify types of sitting postures when people are involved in various tasks during their working hours. Background: Physical behaviors in reaction to user contexts were studied, such as automated posture analysis for detecting a subject's emotion. Sitting postures have high feasibility and can be detected robustly with a sensing chair, especially when it comes to an office. Method: First, we attached seven sensors, including six pressure sensors and one distance sensor, to an office chair. In Part 1, we recorded participants' postures while they took part in four different tasks. From the seven sensors, we gathered five sets of data related to the head, the lumbar, the hip, thigh pressure and the distance between the backrest and the body. We classified them into four postures: leaning forward, upright, upright with the lumbar supporting, and leaning backward. In part 2, we requested the subjects to take suitable poses for the each of the four task types. In this way, we compared the matches between postures and tasks in a natural setting to those in a controlled situation. Results: We derived four types of sitting postures that were mapped onto the different tasks. The comparison yielded no statistical significance between Parts 1 and 2. In addition, there was a significant association between the task types and the posture types. Conclusion: The users' sitting postures were related to different types of tasks. This study demonstrates how human emotion can interact with lighting, as mediated through physical behavior. Application: We developed a posture-based lighting system that manipulates the quality of office lighting and is operated by changes in one's posture. Facilitated by this system, color temperatures ranging between 3,000K and 7,000K and illuminations ranging between 300lx and 700lx were modulated.

• Journal of the Korean Society of Physical Medicine
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• v.15 no.2
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• pp.23-30
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• 2020

PURPOSE: The purpose of this study was to examine the effects of dual-task training with cognitive tasks on cognitive functions and β-amyloid levels in the elderly with mild dementia. METHODS: The subjects were 36 elderly inpatients diagnosed with mild dementia at S Hospital located in Gyeongsangbuk-do, South Korea. The patients were randomly divided into a dual-task training group (DTG; n = 18) or a single-task training group (STG; n = 18). DTG performed dual-task training with cognitive tasks while STG performed only exercise tasks. These groups performed their respective exercises during a 30-minute session occurring three times a week over an 8-week period. MMSE-K and GDS were used to measure the subjects' cognitive function. To assess the subjects' dementia-related factors, their β-amyloid levels were measured by blood analysis. RESULTS: The results of the experiment were as follows: DTG showed statistically significant differences between their MMSE-K scores and β-amyloid levels before and after training (p < .05), whereas they exhibited no statistically significant differences in their GDS scores. MMSE-K scores and β-amyloid levels were significantly different between DTG and STG after training. CONCLUSION: The present study's overall results indicate that dual-task training with cognitive tasks is more effective than single-task training in improving cognitive functions and β-amyloid levels in the elderly with mild dementia. In other words, regular dual-task training can be considered as effective in improving cognitive function and dementia-related factors in the elderly with mild dementia and thus may be suggested as an effective exercise method for the treatment and early prevention of dementia.

• International Journal of Internet, Broadcasting and Communication
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• v.10 no.1
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• pp.31-39
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• 2018

The purpose of this study was to examine the meaning and structure of nurses' computer using experience. To do this, we conducted a total of three interviews with 11 nurses working between the ages of 26 and 48. Interview data were interpreted using Giori method (1985) and Lincoln & Guba method (1985). As a result, 112 semantic units were derived, and then 18 sub-components were divided into 5 final components. As a result of the analysis, the computer experience that the nurses used in the hospital consisted of 'used for almost every task', 'usefulness', 'important', 'convenience', 'burden', 'anxiety', desire', simple work level', 'no problems', 'eye, muscle and movement discomfort', 'depends on task', 'more complex', 'accuracy', 'organize contents', 'simple', 'incomparable', and 'easy'. Based on the above conclusions, the nurses' experiences of using the computer in the hospital could be concluded as follows. Currently, almost all nursing jobs in hospitals are using computers. However, most of the tasks related to simple computer tasks related to the ability to use the computer was low, and because of this, the computer did not work properly, or when new programs were introduced to feel the burden and anxiety, want more systematic computer education Found. Especially, according to the career, the difference between computer and hand work was different, Nurses over 20 years said that computers can handle simple tasks that are a bit more complicated than manual tasks, whereas emotional tasks were handicapped, in the 10 to 20 years of experience, computer work was more accurate and appropriate to organize content, Nurses under 10 years were not only easy to work with computers but also have no experience in manual work, they could not compare the computer and the hand work. This study suggests that the use of computers in nurses' work is essential and that more systematic computer-based education should be provided. In addition, due to the nature of the nursing service, the professional opinions of the nurses should be reflected in the development of programs for the emotional nursing work.

• School Mathematics
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• v.16 no.1
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• pp.1-17
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• 2014

Mathematical creativity in school mathematics is connected with problem solving. The purpose of this study was to analyse elementary students' the mathematical creativity using multiple solution tasks which required to solve a mathematical problem in different ways. For this research, I examined and analyzed the response to four multiple solution tasks according to the evaluation system of mathematical creativity which consisted of the factors of creativity(fluency, flexibility, originality). The finding showed that mathematical creativity was different between students with greater clarity. And mathematical creativity in tasks was different. So I questioned the possibility of analysis of students' the mathematical creativity in mathematical areas. According to the evaluation system of mathematical creativity of this research, mathematical creativity was proportional to the fluency. But the high fluency and flexibility was decreasing originality because it was easy for students to solve multiple solution tasks in the same ways. So, finding of this research can be considered to make the criterion in both originality in rare and mathematical aspects.

• Archives of design research
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• v.16 no.1
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• pp.261-270
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• 2003

This paper focuses on the navigation methods which users select in different websites or for different tasks. Identifying the preferred navigation methods used for each case would help developers to construct the structure of website more effectively and confidently. To achieve the goal, this paper presents a framework on the classification of links as S_link and C_link. Then experiment is designed in order to evaluate the type of preferred link in each case. For the experiment, two different types of prototype websites such as news sites and shopping sites were constructed for which two different types of tasks such as goal-centered tasks and process-centered tasks were given to users. Particularly, to minimize the effects of visual elements and technical difference, prototype websites were produced with only HTML, not JavaScript nor Shockwave Flash. The result showed dearly that type of tasks had more significant effects on users navigation patterns than type of website. And users are more dependent on the S_link in the goal-centered task and on the C_link in the process-centered task. These findings were more apparent at the Qualitative test which was conducted for the comparative analysis between prototype site and real site.

• Journal of Korean Public Health Nursing
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• v.26 no.1
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• pp.101-112
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• 2012

Purpose: The purposes of this study were to identify differences of duties, tasks, and task elements of care helpers between long term care (LTC) facilities and client's home (CH), and to provide data for the development of educational programs and policies. Methods: This study was a descriptive investigation; the subjects of the study were 418 care helpers. Duties, tasks, and task elements were measured using the framework proposed by Shin et al. (2012). Data were analyzed by t-test using PASW 18.0. Results: All of the jobs were statistically significant differences between LTC and CH. Dietary assistance and Daily work assistance were more frequently in CH, and the frequency of other tasks was higher in LTC than CH. Tasks with higher-reported difficulty by those who worked in LTC were as follows: personal hygiene, position change and movement, exercise and activity assistance, safety care, communication assistance, dietary assistance, environment management, daily work assistance, emergency prevention, early detection and speedy reporting, and dementia patient care. Conclusion: These findings suggest that training for care helpers of each facility type will be differentiated. Tasks and task elements reported by care helpers were modified and added to the standard textbook.

• Korean Journal of Construction Engineering and Management
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• v.20 no.2
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• pp.60-67
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• 2019

The main purpose of this study is to identify the tasks performed at the construction stage of apartment houses and analyze the major construction tasks that may affect the performance indicators and analyze the impact on project performance. Based on expert opinions through preliminary research, pilot data, construction database, and other research trends, domestic and foreign research trends are divided into five major tasks, and each is divided into process management (P'1 ~ P'6), construction management (C'1 ~ C'5), environmental management (E'1 ~ E'4), quality control (Q'1 ~ Q'5), safety management (S'1 ~ S'5). Subsequently, each major task was subdivided into 24 detailed tasks. An independent t-test was conducted to analyze the impact on cost. We compared the importance of achieving the project goal and identified the construction work of concrete important construction which affects not only the cost but also the schedule performance index for the degree of significance of less than 0.05.

• The Mathematical Education
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• v.58 no.1
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• pp.55-77
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• 2019

Textbooks play a very important role as a medium for implementing curriculum in the school. This study aims to analyze tasks for mathematical competencies in the high school 'mathematics' textbooks based on the 2015 revised mathematics curriculum emphasizing competencies. And our study is based on the following two research question. 1. What is the relationship between core competencies and mathematical competencies? 2. What is the distribution of competencies of tasks for mathematical competencies presented in the textbooks? 3. How does the tasks for mathematical competencies reflect the meaning of the mathematical competencies? For this study, the tasks, marked mathematical competencies, were analyzed by elements of each mathematical competencies based on those concept proposed by basic research for the development of the latest mathematics curriculum. The implications of the study are as follows. First, it is necessary to make efforts to strengthen the connection with core competencies while making the most of characteristics of subject(mathematics). Second, it needs to refine the textbook authorization standards, and it should be utilized as an opportunity to improve the textbook. Third, in order to realize competencies-centered education in the school, there should be development of teaching and learning materials that can be used directly.

• The Mathematical Education
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• v.62 no.2
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• pp.237-255
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• 2023

The objective of this study is to explore the meaning generated through discourse in three different types of 1st-grade middle school textbooks in Korea and CMP textbook in the United States, specifically focusing on histograms. Through a discursive perspective, the study aims to analyze the characteristics of questioning within the stages of statistical problem-solving found in histogram tasks. The findings highlight several significant points. Firstly, variations exist in the definitions of histograms between Korean and US CMP textbooks. Secondly, diverse discursive structures contribute to the interpretation and understanding of histograms in textbooks. Thirdly, limitations are observed in the stages of statistical problem-solving reflected in histogram tasks. Lastly, distinctions are identified in the types of questioning employed in histogram tasks between Korean and US CMP textbooks. Building on these insights, the study suggests concrete ideas for enhancing the process of defining histograms and refining the questioning in histogram tasks.