• KSII Transactions on Internet and Information Systems (TIIS)
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• v.8 no.11
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• pp.3655-3673
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• 2014

Rendezvous is a process of two or more cognitive radio nodes gathering on the same channel at the same time for a negotiation to establish data communications. This paper discusses rendezvous issues in cognitive radio networks. It details why rendezvous is an issue in cognitive radio networks and how rendezvous works. It classifies channel access methods, and details sequence-based channel-hopping methods. It surveys existing works on blind rendezvous and compares the proposed algorithms in terms of the maximum time to rendezvous. This paper discusses the properties that an efficient channel-hopping rendezvous algorithm should have and illustrates common issues in the existing rendezvous methods. It also explains open research issues in the rendezvous area.

• Journal of Institute of Control, Robotics and Systems
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• v.16 no.1
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• pp.33-39
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• 2010

The interaction of emotion is an important factor in Human-Robot Interaction(HRI). This requires a contextual appraisal of emotion extracting the emotional information according to the events happened from past to present. In this paper an emotion appraisal system based on the cognitive context is presented. Firstly, a conventional emotion appraisal model is simplified to model a contextual emotion appraisal which defines the types of emotion appraisal, the target of the emotion induced from analyzing emotional verbs, and the transition of emotions in the context. We employ a language based cognitive system and its sentential memory and object descriptor to define the type and target of emotion and to evaluate the emotion varying with the process of time with the a priori emotional evaluation of targets. In a experimentation, we simulate the proposed emotion appraisal system with a scenario and show the feasibility of the system to HRI.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.34 no.11A
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• pp.822-830
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• 2009

The spectrum efficiency of mobile communication networks can be improved dramatically adopting multiple antennas technologies. In order to guarantee the licensed rights of primary user (PU), the cognitive radio system should perform in a relatively low interference manner when it gets access to the spectrum of licensed networks. In this paper, we explore a uniformly distributed circular antenna array to implement beamforming algorithm that is accomplished by optimization method at the base station of cognitive radio networks, and therefore we can suppress the interference to PU by steering quite low transmission power toward PU and constructing a narrow beam toward cognitive user (CU). By reducing the constraint number of the optimization problem, we also propose a null steering algorithm that steers rather low radiation power toward PU, while the other areas in the same cell are covered by radiation power except the local area around PU. It is pursued to reduce the computation load and enlarge the capacity of cognitive radio networks extremely. The simulation results demonstrate that the proposed algorithms process superior performance.

• Journal of Information Processing Systems
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• v.10 no.1
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• pp.119-131
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• 2014

In recent literature on traffic scheduling, the combination of the two-dimensional discrete-time Markov chain (DTMC) and the Markov modulated Poisson process (MMPP) is used to analyze the capacity of VoIP traffic in the cognitive radio system. The performance of the cognitive radio system solely depends on the accuracy of spectrum sensing techniques, the minimization of false alarms, and the scheduling of traffic channels. In this paper, we only emphasize the scheduling of traffic channels (i.e., traffic handling techniques for the primary user [PU] and the secondary user [SU]). We consider the following three different traffic models: the cross-layer analytical model, M/G/1(m) traffic, and the IEEE 802.16e/m scheduling approach to evaluate the performance of the VoIP services of the cognitive radio system from the context of blocking probability and throughput.

• The Mathematical Education
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• v.46 no.4
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• pp.483-492
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• 2007

The purpose of this study was to investigate the relation between the cognitive processes and the mathematical achievement of the 4th grade students. And according to the several studies, there were significant relation between cognitive processes and achievement. Based on the PASS(Planning-Attention-Simultaneous-Successive Processes) Model presented by Das and Naglieri, four cognitive process variables were selected. The results of this study as follows. First, there was not significant relation between attention and mathematical achievement. Second, there was significant relation between planning and mathematical achievement. Third, there was significant relation between simultaneous/successive processes and mathematical achievement. Fourth, the students who got higher scores in the two types (simultaneous/successive)of information processing had more mathematical achievement. Specially, the students who got higher scores in the type of simultaneous information processing had higher scores in mathematical achievement. These results indicated that planning and simultaneous information processing had influence on the mathematical achievement.

• Research in Mathematical Education
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• v.23 no.2
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• pp.63-92
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• 2020

Student engagement in high-level, cognitively demanding instruction is pivotal for student learning. However, many teachers are unable to maintain such instruction, especially in instances of non-responsive students. This case study of three middle school teachers explores prompts that aim to move classroom discussions past student silence. Prompt sequences were categorized into Progressing, Focusing, and Redirecting Actions, and then analyzed for maintenance of high levels of cognitive demand. Results indicate that specific prompt types are prone to either raise or diminish the cognitive demand of a discussion. While Focusing Actions afforded students opportunities to process information on a more meaningful level, Progressing Actions typically lowered cognitive demand in an effort to get through mathematics content or a specific method or procedure. Prompts that raise cognitive demand typically start out as procedural or concrete and progress to include students' thoughts or ideas about mathematical concepts. This study aims to discuss five specific implications on how teachers can use prompting techniques to effectively maintain cognitively challenging discourse through moments of student silence.

• Proceedings of the Korean Nuclear Society Conference
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• 1996.05a
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• pp.349-354
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• 1996

SACOM(Simulation Analyser with Cognitive Operator Model) is being developed at Korea Atomic Energy Research Institute to simulate human operator's cognitive characteristics during the emergency situations of nuclear power plans. An operator model with error mechanisms has been developed and combined into SACOM to simulate human operator's cognitive information process based on the Rasmussen's decision ladder model. The operational logic for five different cognitive activities (Agents), operator's attentional control (Controller), short-term memory (Blackboard), and long-term memory (Knowledge Base) have been developed and implemented on blackboard architecture. A trial simulation with a scenario for emergency operation has been performed to verify the operational logic. It was found that the operator model with error mechanisms is suitable for the simulation of operator's cognitive behavior in emergency situation.

• Korean Journal of Construction Engineering and Management
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• v.24 no.6
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• pp.91-98
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• 2023

Construction accidents result from a combination of factors, including both the actions of workers and the safety conditions on site. Despite advancements in enhancing construction site safety, there remains a gap in comprehending the cognitive processes underlying workers' unsafe behavior. This paper investigates and validates a qualitative model that delves into the potential causes of workers' unsafe actions by examining their cognitive processes, employing a system dynamics approach. By analyzing the interplay of various loops within this model, it offers both short- and long-term safety strategies for managers intent on minimizing unsafe behavior among workers. Specifically, safety managers should prioritize increasing workers' awareness of hazards through education and fostering a positive safety mindset. Moreover, they should task frontline supervisors with directly addressing and rectifying instances of unsafe behavior by workers. Lastly, construction safety managers ought to formulate safety strategies that take into account the cognitive states of workers to mitigate any adverse consequences of biased safety management. The outcomes of this research contribute to our comprehension of methods to enhance hazard perception among workers, curtail unsafe actions, and ultimately reduce construction accidents from a cognitive standpoint.

• Proceedings of the Korea Technology Innovation Society Conference
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• 2017.05a
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• pp.195-218
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• 2017

The paper tests the above socio-cognitive model with four empirical case studies of leading Korean science and technology research and technology transfer organizations. The case studies demonstrate clear differences in individuals' frames about the technology transfer process and arising conflicts. As a result, technology transfer process is not fully controllable and is highly contextual. We argue, whereas public policy in countries approaching technology frontier provides essential support for defining and exploiting best practices (routines/pathways) for technology transfer at organizational level, they have not matured enough to support the timely identification and resolution of conflicts between individual actors, hence the inefficiencies. Therefore, among others, public policy for technology transfer could consider allowing an inclusive approach to recognition of best practices for technology transfer and innovation processes, increased social interactions between technology transfer actors, and their training on resolution of individual level cognitive conflicts.

• Journal of the Korean Institute of Intelligent Systems
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• v.14 no.3
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• pp.342-348
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• 2004

As the advent of the Internet, B2B negotiation process on the Internet has been given attention from both researchers and practitioners. However, literature still shows that only structured conditions have been explicitly considered, despite the fact that unstructured conditions should be rendered as well. In this sense, this paper proposes a new negotiation support mechanism to incorporate causal relationships between structured and unstructured conditions in the process of B2B negotiation. Fuzzy cognitive map was used as a main source of causal knowledge as well causal inference engine. A prototype named CAKES-NEGO was developed to perform experiments with an illustrative example. Results revealed the robustness of our proposed negotiation support mechanism.