• ETRI Journal
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• v.37 no.3
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• pp.491-501
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• 2015

Spectrum sensing is an elementary function in cognitive radio designed to monitor the existence of a primary user (PU). To achieve a high rate of detection, most techniques rely on knowledge of prior spectrum patterns, with a trade-off between high computational complexity and long sensing time. On the other hand, blind techniques ignore pattern matching processes to reduce processing time, but their accuracy degrades greatly at low signal-to-noise ratios. To achieve both a high rate of detection and short sensing time, we propose fast spectrum sensing with coordinate system (FSC) - a novel technique that decomposes a spectrum with high complexity into a new coordinate system of salient features and that uses these features in its PU detection process. Not only is the space of a buffer that is used to store information about a PU reduced, but also the sensing process is fast. The performance of FSC is evaluated according to its accuracy and sensing time against six other well-known conventional techniques through a wireless microphone signal based on the IEEE 802.22 standard. FSC gives the best performance overall.

• Korean Medical Education Review
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• v.12 no.2
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• pp.27-33
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• 2010

The purpose of this study was to review the definition of cognitive load (CL), the relationship between CL and instructional design, and to provide a viewpoint of CL in curriculum and instructional design in medical education. Cognitive load theory (CLT) makes use of three hypotheses about the structure of human memory: working memory (WM) is limited in terms of the amount of information it can hold, in contrast with WM, long term memory is assumed to have no limits and organizes information as schemata. CL indicates the mental load on the limitation of WM. CLT has been used to design instructional interventions that help to ease the learning process. Extraneous CL is related to irrelevant instructional interventions, while intrinsic CL is the complexity of the information itself. Germane CL is the cognitive process for acquiring schema formation. It is a necessary CL to achieve deeper comprehension and solve problems. The range of medical education includes complex, multifaceted and knowledge-rich domains with clinical skills and attitudes. Therefore, CLT may be used to guide instructional design in medical education in terms of decreasing extraneous CL, adjusting intrinsic CL and enhancing the germane CL.

• Journal of Science of Art and Design
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• v.13 no.1
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• pp.23-37
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• 2008

Recently, there are getting popular form generation-related design methodologies and scientific discourses about the nature of nature in the environmental design. The necessity of visual perception and cognitive research is growing in this respect. Accordingly, this study was designed to discuss environmental design and cognition in the ecological perspective. This study was intended to study the structural factors of cognitive ecological space. This study focused on the systematic principle of new environmental design based on cognitive ecological approaches and what kinds of design effects this design principle has on the human being in the long nm. The results are as follows. First, the results suggests that fractal pattern should be an alternative to design cognitive ecological space and new paradigm of architecture is based on the nature of nature and human sensibility. Accordingly, they have proposed that fractal design is more empirical and environment-friendly than rational linear design. Second, this study classified the variables of cognitive ecological space into nature, tradition, preference judgement, aesthetic value, and schema. Accordingly, such features as symbol, tradition, and nature restricted by modernistic ideology should be added to new paradigm-based environmental design. Third, accordingly, this study stresses that cognitive ecological environmental design doesn't include buildings of modernism and deconstruction and is based on new science of complexity.

• Journal of the Ergonomics Society of Korea
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• v.32 no.1
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• pp.59-68
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• 2013

Objective: The purpose of this paper is to introduce a task complexity model combining task design aspects and complexity dimensions and to explain an approach to identifying and organizing task complexity factors based on the model. Background: Task complexity is a critical concept in describing and predicting human performance in complex systems such as nuclear power plants(NPPs). In order to understand the nature of task complexity, task complexity factors need to be identified and organized in a systematic manner. Although several methods have been suggested for identifying and organizing task complexity factors, it is rare to find an analytical approach based on a theoretically sound model. Method: This study regarded a task as a system to be designed. Three levels of design ion, which are functional, behavioral, and structural level of a task, characterize the design aspects of a task. The behavioral aspect is further classified into five cognitive processing activity types(information collection, information analysis, decision and action selection, action implementation, and action feedback). The complexity dimensions describe a task complexity from different perspectives that are size, variety, and order/organization. Combining the design aspects and complexity dimensions of a task, we developed a model from which meaningful task complexity factors can be identified and organized in an analytic way. Results: A model consisting of two facets, each of which is respectively concerned with design aspects and complexity dimensions, were proposed. Additionally, twenty-one task complexity factors were identified and organized based on the model. Conclusion: The model and approach introduced in this paper can be effectively used for examining human performance and human-system interface design issues in NPPs. Application: The model and approach introduced in this paper could be used for several human factors problems, including task allocation and design of information aiding, in NPPs and extended to other types of complex systems such as air traffic control systems as well.

• Journal of Educational Research in Mathematics
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• v.14 no.3
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• pp.267-281
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• 2004

Many students feel the word problems are very difficult. This study analyzes the linguistic and cognitive factors that affect word problem solving so that we help students bring through the difficulty. There are a text base, a situation model, and a real world in the linguistic aspects. Students have a difficulty at the transition from text base to situation model(equation), and make lots of errors at the situation model. In the cognitive aspects, I investigated problem solving schemes, strategies, and complexity level. Students are likely to choose strategy by the contents which teacher instructed, but not by low complexity level, and mix up the amount of sugar and sugar water, and concentration. We can recognize how complex the types of word problems are to solve, which strategies students choose largely, and what errors that students make in the problem solving are.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.9 no.8
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• pp.2774-2796
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• 2015

Quality-of-service (QoS) provisioning for a cognitive mesh network (CMN) with heterogeneous services has become a challenging area of research in recent days. Considering both real-time (RT) and non-real-time (NRT) traffic in a multihop CMN, [1] studied cross-layer resource management, including joint access control, route selection, and resource allocation. Due to the complexity of the formulated resource allocation problems, which are mixed-integer non-linear programming, a low-complexity yet efficient algorithm was proposed there to approximately solve the formulated optimization problems. In contrast, in this work, we present an application of genetic algorithm (GA) to re-address the hard resource allocation problems studied in [1]. Novel initialization, selection, crossover, and mutation operations are designed such that solutions with enough randomness can be generated and converge with as less number of attempts as possible, thus improving the efficiency of the algorithm effectively. Simulation results show the effectiveness of the newly proposed GA-based algorithm. Furthermore, by comparing the performance of the newly proposed algorithm with the one proposed in [1], more insights have been obtained in terms of the tradeoff among QoS provisioning for RT traffic, throughput maximization for NRT traffic, and time complexity of an algorithm for resource allocation in a multihop network such as CMN.

• Educational Technology International
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• v.25 no.1
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• pp.27-65
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• 2024

The purpose of this study was to identify differences in learning patterns according to content complexity in video-based learning environments and to derive variables that have an important effect on learning achievement within particular learning contexts. To achieve our aims, we observed and collected data on learners' cognitive processes through perceived affordances, using behavioral logs and eye movements as specific indicators. These two types of reaction data were collected from 67 male and female university students who watched two learning videos classified according to their task complexity through the video learning player. The results showed that when the content complexity level was low, learners tended to navigate using other learners' digital logs, but when it was high, students tended to control the learning process and directly generate their own logs. In addition, using derived prediction models according to the degree of content complexity level, we identified the important variables influencing learning achievement in the low content complexity group as those related to video playback and annotation. In comparison, in the high content complexity group, the important variables were related to active navigation of the learning video. This study tried not only to apply the novel variables in the field of educational technology, but also attempt to provide qualitative observations on the learning process based on a quantitative approach.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2003.05a
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• pp.958-965
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• 2003

The rapidly changing business environment has required cooperation and coorduiation among functional units n organizations which should Involve group decision-making processes Although many group derision-making support tools and methods have provided the collaborative capabilities for organizational members, they often lack features supporting the dynamic complexity issue frequently occurring at group decision-making processes This study proposes system dynamics modeling as a group decision-making support tool to deal with the group derision-making tasks having properties of dynamic complexity in terms of cognitive fit theory.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.17 no.30
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• pp.185-192
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• 1994

The complexity and consistency are important factors that affect human information processing in use of product. In this study, complexity and consistency of product(remote controller) are measured by Task Action Grammar(TAG) model. Also, new design alternative of the user interface is presented and evaluated. The results show that the consistent system and the good correspondence between hierarchical structure of system and user's mental model lead to the reduction of errors and enhanced user's performance.

• Korean journal of communication and information
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• v.46
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• pp.75-107
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• 2009

Nevertheless reported the same events, news audience have diverse sense of sights and opinions about the events because of the different news frames. This notion was repeatedly evi nnced by several framing studies. This pa wa tried to analyse an interacting relationship between viewer’s level of elaboration likelihood and the effects of the news frames. This pa wa sfrrted with a discussion about the framing effects, then compared them with Elaboration Likelihood Ms notraming effely. And this study conducted an ex waiment selecting indivi ual dispngitions (involvement and cognitive complexity) and message characteristics(number of cues and arguments) as intermediating variables on the message framing effects. This study found out that, the more involvement about the issues the viewers had, the more their thoughts coincided with the issue's frame. On the other hand, when the viewers had low involvement about the issues and cognitive complexity, the framing effects were not found because they processed the messages through the peripheral route. Although the viewers' cognitive complexity was a factor in choosing the central route, but it was not directly connected to the framing effect. Both the number of cues and argument diversity in the messages had positive relationships with the framing effects.