• The Mathematical Education
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• v.57 no.2
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• pp.137-155
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• 2018

From the assumption that an individual's working memory capacity is limited, the cognitive load theory is concerned with providing adequate instructional design so as to avoid overloading the learner's working memory. Based on the cognitive load theory, this study aimed to provide implications for effective problem-based collaborative teaching and learning design by analyzing the level of middle school students' cognitive load which is perceived according to the problem types(short answer type, narrative type, project) in the process of collaborative problem solving in middle school function part. To do this, this study analyzed whether there is a relevant difference in the level of cognitive load for the problem type according to the math achievement level and gender in the process of cooperative problem solving. As a result, there was a relevant difference in the task burden and task difficulty perceived according to the types of problems in both first and second graders in middle schools students. and there was no significant difference in the cognitive effort. In addition, the efficacy of task performance differed between first and second graders. The significance of this study is as follows: in the process of collaborative problem solving learning, which is most frequently used in school classrooms, it examined students' cognitive load according to problem types in various aspects of grade, achievement level, and gender.

• Journal of the Korean Society of Safety
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• v.14 no.3
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• pp.174-180
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• 1999

The objective of this study was to investigate the effects of carrying postures and weight of load carried one time on a worker when carrying heavy loads. Six male students participated in this study to perform a manual materials carrying task as subjects. To make comparison of work loads with physical work capacity, maximal oxygen uptake measurement tests were performed with submaximal test. The average oxygen consumption for the tasks of this study was 27.59~31.93% $VO_2$max. The results showed that the weight of load carried one time affects on working heart rate and oxygen consumption($VO_2$). It was found that the workload was significantly lower when handling a 20kg load at a frequency rate of 3times/min than when handling a 40kg load at a frequency rate of 1.5 times/min. There was no difference between carrying postures. It is concluded from the results of this study that the workload can be reduced by controlling conditions of a manual materials handling task.

• Journal of Korea Society of Digital Industry and Information Management
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• v.13 no.4
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• pp.153-162
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• 2017

Advances in communication technologies and the decreasing cost of computers have made distributed computer systems an attractive alternative for satisfying the information needs of large organizations. This paper presents a distributed algorithm for performance improvement through load balancing and file migration in distributed systems. We employed a sender initiated strategy for task migration and used learning automata with several internal states for file migration. A task can be migrated according to the load information of a computer. A file is migrated to the destination processor when it is in the right boundary state. We also described an analytical model for load balancing with file migration to verify the proposed algorithm. Analytical and simulation results show that our algorithm is very well-suited for distributed system environments.

• International Journal of Contents
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• v.3 no.1
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• pp.34-38
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• 2007

Load redistribution is a critical resource in computer system. In sender-initiated load redistribution algorithms, the sender continues to send unnecessary request messages for load transfer until a receiver is found while the system load is heavy. These unnecessary request messages result in inefficient communications, low CPU utilization, and low system throughput in distributed systems. To solve these problems, we propose a genetic algorithm based approach for improved sender-initiated load redistribution in distributed systems. Compared with the conventional sender-initiated algorithms, the proposed algorithm decreases the response time and task processing time.

• Journal of the HCI Society of Korea
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• v.14 no.2
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• pp.31-39
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• 2019

This research examined the changes that fast-growing voice-based devices would bring in the media multitasking environment. Based on the theoretical background that information processing efficiency improves when performing multiple tasks requiring different resource structures at the same time, we conducted an experiment where participants searched for information with voice-based or screen-based devices while performing an additional visual task. Results showed that both task performance environment and interface modality had significant main effects on cognitive load. The overall cognitive load level was higher in the voice interface group, but the difference in cognitive load between the two groups decreased in a multitasking environment where the additional visual resources was required. The visual task performance was significantly higher when using the voice interface than the screen interface. Our findings suggest that voice interfaces offered advantages in the cognitive load and task performance by distributing two tasks to the auditory and visual channels. The results of this study imply that voice-based devices have the potential to facilitate efficient information processing in the screen-centric environment where visual resources collide. We provided theoretical evidence of resource distribution using multiple resource theory and tried to identify the advantages of the voice interface more specifically based on the threaded cognition model.

• Science of Emotion and Sensibility
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• v.12 no.3
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• pp.279-288
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• 2009

The purpose of this study was to verify the impact of cognitive factors and GSR on the task performance. For this study 64 students participated. Multiple regression and repeated measures were applied to analyze the data. The result for the survey indicated that previous knowledge, physical efforts, and task difficulty had significant impacts on task performance. Particularly, task difficulty has a negative impact. This can be interpreted as someone who has high prior knowledge inputs higher physical efforts with low task difficulty perception will show high performance. On the other hand, the low arousal level of GSR in the evaluation stage is a prediction variable of task performance. This result shows that high prior knowledge and low arousal level of GSR produces high performance. However, the analysis of difference in GSR between learning and evaluation stages does not show significant difference. It suggests that physiological measure such as GSR is reliable index of cognitive load; however, it partially represents cognitive load. Other crucial factors should be added for comprehensive measures.

• Journal of Biomedical Engineering Research
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• v.43 no.1
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• pp.52-60
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• 2022

Purpose: For now, cognitive load is assessed based on survey-based methods, which can be difficult to track the amount of cognitive load in real-time. In this study, we investigated the difference in electrophysiological activation due to different levels of cognitive load not only at sensor-level but also at source-level using electroencephalogram that might be potentially used for quantitative cognitive load evaluation. Materials and Methods: In this study, ten healthy subjects (mean age 24.3 ± 2.1, three female) participated the experiment. All participants performed 4 sessions of n-back task in different difficulties: 0-, 1-, 2-, and 3-back during electroencephalogram recording. For sensor-level analysis, we calculated the event-related potential and event-related spectral perturbation while low resolution brain electromagnetic tomography (LORETA) to estimate the source activation. Each result was compared between different workload conditions using statistical analysis. Results: Statistical results revealed that the accuracy of the task performance was significantly different between different cognitive loads (p = 0.018). The post-hoc analysis confirmed that the accuracy of the 3-back task was significantly decreased compared to 1-back condition (p = 0.018), but not with 2-back condition (p = 0.180). ERP results showed that P300 target amplitude between 1-back and 3-back had a marginal difference in Cz (p = 0.059) and Pz(p = 0.093). A significant inhibition in Cz high-beta activation (p = 0.017) and decrease in source activation of right parahippocampal gyrus was found in 3-back condition compared to 1-back condition (p < 0.05). Conclusion: In this study, we compared the sensor- and source-level differences in electroencephalogram between different levels of cognitive load, that were found to be in line with the previous reports related to cognitive load evaluation. We expect that the outcome of the current study can be used as a feature to establish a quantitative cognitive load assessment system.

• Journal of The Korean Association of Information Education
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• v.20 no.6
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• pp.629-644
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• 2016

The purpose of this study was to investigate the effects of whole-task sequencing emphasis manipulation on expertise acquisition in web based complex task. To achieve the purpose, emphasis manipulation sequencing type is composed of a simple emphasis manipulation, a snowballing manipulation, and a full emphasis manipulation sequencing and participants was drawn from a pool of 93 undergraduate students sampled for the study. According to the findings, a snowballing manipulation group invested significantly lower cognitive load than a full emphasis manipulation group but did not a simple emphasis manipulation group. Based on these findings, though complex task is included of high interactivity owing to real task, learner cannot suffer cognitive overload because emphasis manipulation which can view the whole task and the part task in parallel provides meta cognition for learner. And whole-task sequencing emphasis manipulation affects to transfer. The snowballing emphasis manipulation group invested significantly higher than simple emphasis manipulation group and full emphasis manipulation group. Based on these findings, the snowballing manipulation which learner use whole-task sequencing and part-task sequencing simultaneously contribute to understandings and ability to solve problems for complex task and it will in turn, lead to expertise acquisition.

• Proceedings of the Korean Society for Emotion and Sensibility Conference
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• 2002.11a
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• pp.114-119
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• 2002

In driving situation, driver’s performance can be divided into primary task and secondary task. Many studies of primary task have been in progress, but those of secondary task are not implemented sufficiently. However, the driver’s error is greatly influenced by secondary task. In this study, an experiment was assessed to determine the relationship between the driver's operation time for the secondary task and mental workload due to speed changes in a driving simulation. The time to perform the secondary task was analyzed with Fitts’ Law, and mental workload was analyzed with RNASA-TLX(Revision of NASA-Task Load Index). The results has showed that the higher speed, the weaker the explanation by the use of Fitts' Law and the result of analyzing mental workload using RNASA-TLX was similar to the result of Fitts’ Law.

• Journal of Korean Institute of Industrial Engineers
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• v.37 no.3
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• pp.209-215
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• 2011

The objective of this study was to determine whether there are differences in hand muscle activities (APB : abductor pollicis brevis, ED : extensor digitorum, ECU : extensor carpi ulnaris, and EI : extensor indicis) and subjective discomfort according to the three mouse sizes (small, medium, large) and two task types (pointing and scrolling). The mouse size and task type showed significant interaction effects on the total NEMG (p = 0.004) and on the NEMG of the abductor pollicis brevis muscle (p = 0.001). The total NEMG and the NEMG of APB showed the highest value in the 'scrolling' task using the 'small' mouse. However, the NEMG of the EI was different according to the mouse size, and the 'small' mouse showed the lowest value. The subjective discomfort was the lowest in the 'medium' mouse, and all nine subjects preferred the 'medium' size. The hand-size related anthropometric variables showed different correlations according to the task type and mouse size with the NEMGs and subjective discomfort. The results of this study could be used as a basic information for the determination of the proper mouse size according to the hand size.