• ETRI Journal
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• 제37권3호
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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.

• 의학교육논단
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• 제12권2호
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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.

• 조형예술학연구
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• 제13권1호
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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.

• 대한인간공학회지
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• 제32권1호
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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.

• 대한수학교육학회지:수학교육학연구
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• 제14권3호
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• pp.267-281
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• 2004

방정식의 활용 문제로 다루어지는 문장제는 학생들의 흥미를 유도하고 수학의 유용성을 보여줄 수 있는 것이지만, 학생들이 해결하기에는 여러 어려움이 있다. 본 연구는 학생들이 수학 문장제를 해결하는데 영향을 줄 수 있는 요인들을 언어적 측면과 인지적 측면에서 조사하였다. 언어적 요인에는 텍스트 기반, 실세계, 상황 모델이 있었는데, 학생들은 문장의 텍스트 기반에서 방정식의 상황 모델로 해석하는 것을 어렵게 생각하고 있었으며, 상황 모델에서 학생들은 많은 오류를 보였다. 인지적 측면에서는 방정식을 세우는 스키마와 해결 전략, 식의 복잡성 수준을 조사하였는데, 방정식을 세울 때 학생들은 복잡성 수준을 고려하기보다는 교사의 지도 내용에 따라 전략을 선택하는 경향이 있었다. 그리고 설탕의 양이나 농도, 설탕물의 양을 혼동하는 경향이 강했다. 본 연구의 결과를 통해 문장제에서 학생들에게 제시되는 문제가 해결하기에 얼마나 복잡한지, 학생들이 주로 어떤 전략을 선택하는지, 방정식의 문제 유형별로 발생하는 오류에 대해 알 수 있었다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제9권8호
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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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• 제25권1호
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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.

• 한국경영과학회:학술대회논문집
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• 한국경영과학회/대한산업공학회 2003년도 춘계공동학술대회
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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.

• 산업경영시스템학회지
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• 제17권30호
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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.

• 한국언론정보학보
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• 제46권
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• pp.75-107
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• 2009

본 연구의 목적은 수용자의 인지정교화 가능성과 뉴스 프레임 효과의 관계를 분석하는 것이다. 이를 위해 서로 다른 프레임과 메시지 특성이 적용된 기사를 수용자에게 노출시키는 실험을 통해서 뉴스 프레임 효과가 수용자의 인지정교화 수준에 따라 어떻게 변화하는지를 살펴보았다. 연구 결과, 수용자의 이슈에 대한 관여도가 높을수록 뉴스 프레임에 대한 동조화 정도가 높은 반면, 수용자가 비평적으로 사고하는 성향이 강할수록 뉴스 프레임에 대한 동조화는 적거나 역방향으로 나타나고 있다. 따라서 수용자 요인 중에서 비평적 사고를 즐기는 성향은 높은 수준의 인지정교화를 결정짓는 요인이긴 하지만, 반드시 프레이밍 효과로까지 이어지는 요인은 아니었다. 관여도가 낮은 이슈일수록 수용자들은 주변경로로 정보를 처리하는 경우가 많은 것으로 확인되었다. 메시지 특성 변인으로 논증과 단서의 양이 많을수록 프레임에 대한 동조화 정도가 높은 것으로 확인되었다. 논증과 단서의 양이 적을수록 수용자들은 주변경로를 통해 정보를 처리하는 경우가 많았다. 관여도의 경우, 고관여 이슈에서는 단서보다 논증의 양에 따라서 프레이밍 효과가 결정되는 반면, 저관여 이슈에서는 단서의 양에 따라서 프레이밍의 효과의 차이가 나타나고 있다.