• Korean Journal of Cognitive Science
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• v.10 no.4
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• pp.71-83
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• 1999

Conventional symbolic inference systems lack flexibility because they do not well reflect flexible semantic structure of knowledge and use symbolic logic for their basic inference mechanism. For solving this problem. we have recently proposed the 'Connectionist Semantic Network(CSN)' as a model for flexible knowledge representation and inference based on neural networks. The CSN is capable of carrying out both approximate reasoning and commonsense reasoning based on similarity and association. However. we have difficulties in representing general and structured high-level knowledge and variable binding using the connectionist framework of the CSN. In this paper. we propose a hybrid system called SymCSN(Symbolic CSN) that combines a symbolic module for representing general and structured high-level knowledge and a connectionist module for representing and learning low-level semantic structure Simulation results show that the SymCSN is a plausible model for human-like flexible knowledge representation and inference.

• Korean Institute of Interior Design Journal
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• v.26 no.5
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• pp.135-142
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• 2017

Recently, as human-centered design and humanization of space accelerates, the concept of physical space is changing to user-centered space. In particular, in the case of exhibition space to utilize digital media, visitors' actively experiencing exhibits and participating exhibition are regarded as an important factor, thus affordance design serves as a crucial factor to afford satisfaction with exhibition space to the visitors. Accordingly, the study is to understand the concept of the affordance and the digital media exhibition environment and to analyze the preference for each affordance design factor in the digital exhibition environment. The survey is conducted to people in the twenties who inhabit Seoul and the metropolitan area, familiar with the digital media. The results of the survey show that the most important role of the digital media in the exhibition environment is to create the atmosphere for concentration and complexity is the most preferable among interactivity, network ability and complexity, the feature of the digital media. Additionally, the results reveal that cognitive affordance presenting the feature of design to help the user when he/she want to know something is the most preferable among sensory affordance, physical affordance, cognitive affordance and functional affordance and as the time exposed to the digital media increases the importance of the affordance design is high. As the digital environment is common now in many fields, it will be regarded as a crucial factor to the visitors of an exhibit hall from now on whether affordance design is used.

• Korean Journal of Cognitive Science
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• v.19 no.1
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• pp.57-74
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• 2008

This study aimed to investigate the preferential brain activations involed in the set size during random number generation (RNG). The BNG condition gave more increased activations in the anterior cingulate cortex (ACC), inferior frontal gyrus (IFG), inferior parietal lobule (IPL), and superior temporal gyrus (STG) than the simple counting condition, which was a control rendition. When the activations were compared by the small set size condition versus the large set size condition, broad areas covering tempore-occipital network, ACC, and postcentral gyrus were more highly activated in the small set size condition than in the large set size condition, while responses of areas including medial frontal gyrus, superior parietal lobule, and lingual gyrus were more increased in the large set size condition than in the small set size condition. The capacity hypothesis of working memory fails to explain the results. On the contrary, strategy selection hypothesis seems to explain the current observations properly.

• Korean Journal of Cognitive Science
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• v.20 no.4
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• pp.535-554
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• 2009

Information collected on mobile devices might be utilized to support user's memory, but it is difficult to effectively retrieve them because of the enormous amount of information. In order to organize information as an episodic approach that mimics human memory for the effective search, it is required to detect important event like landmarks. For providing new services with users, in this paper, we propose the prediction model to find landmarks automatically from various context log information based on attributed Bayesian networks. The data are divided into daily and weekly ones, and are categorized into attributes according to the source, to learn the Bayesian networks for the improvement of landmark prediction. The experiments on the Nokia log data showed that the Bayesian method outperforms SVMs, and the proposed attributed Bayesian networks are superior to the Bayesian networks modelled daily and weekly.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.39C no.12
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• pp.1289-1297
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• 2014

In this paper, we use the ECMA-392 standard, the first cognitive radio networks to meet the demand for IT services in the ship. We propose a ECMA-392 cooperative MAC protocol to ensure QoS to support multimedia services in the ship area in a multi-hop wireless bridge using ECMA-392 networks. Because the proposed protocol transmits directly or relay transmission by selecting efficient routes based on the information of the ECMA-392 devices, it provides communication to ensure QoS of the device. The simulation results show that the proposed cooperative MAC protocol improves a throughput of devices compared to the existing method.

• Journal of KIISE:Computing Practices and Letters
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• v.16 no.7
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• pp.794-798
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• 2010

Assuming that a wireless link is mostly used at the network edge and the wireless NIC driver keeps monitoring the error rate of its link, this paper proposes an enhanced TCP congestion control, TCP-L (TCP Link-Aware). TCP-L predicts true congestion losses occurred inside the wired link area by utilizing the wireless link error rate. As a result, it mitigates performance degradation caused from TCP congestion control actions when segments losses occur in a wireless link. Experimental results show that TCP-L provides better performance and fairness in lossy wireless links than existing TCP congestion control schemes. Our approach utilizing the characteristic of the link at TCP could be well adapted to new wireless environments such as Cognitive Radio and ACK-less IEEE 802.11, where a frame may be delivered with a very long delay or lost in the link.

• Korean Journal of Cognitive Science
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• v.6 no.2
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• pp.47-79
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• 1995

Since the early age of computer graphics, facial animation has been applied to various fields, and nowadays it has found several novel applications such as virtual reality(for representing virtual agents), teleconference, and man-machine interface.When we want to apply facial animation to the system with multiple participants connected via network, it is hard to animate facial expression as we desire in real-time because of the size of information to maintain an efficient communication.This paper's major contribution is to adapt 'Level-of-Detail'to the facial animation in order to solve the above problem.Level-of-Detail has been studied in the field of computer graphics to reperesent the appearance of complicated objects in efficient and adaptive way, but until now no attempt has mode in the field of facial animation. In this paper, we present a systematic scheme which enables this kind of adaptive control using Level-of-Detail.The implemented system can generate speech synchronized facial expressions with various types of user input such as text, voice, GUI, head motion, etc.

• Korean Journal of Cognitive Science
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• v.7 no.3
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• pp.37-60
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• 1996

From the biopsychological point of view,learning could be defined as the processes to transfer the information that we obtain from environment to the neural circuits in the brain.In the studies to determine the biological substrates of learning and memory,there was a remarkable effort to identify neural circuits related with a specific type of learning and to describe the mechanixm of neural plasticity of learning and memory,under the assumption that the memory orinformation may be stored as a modificationof neural synapes in the central nerviys system.On the other hand,there was a different kind of tendency to analyze the mechanism of interactions between neural substrates involved in learning and memory,under the assumption that a specific information may be represented in the patterns of comples neural network of the central nervous system.The present review,in the former position.focused on the research methods and the chracteristics and finding of the investigations employing animal model systems to indentify the essential site of engram for learning and memory.Specifically,the review presents major advances in ourunderstanding of the memory trace circuit for a specific type of learning,with the use of animal model system,the detemination of the critical lodi of neuaral plastic chabges In learing abd memory,and the neurophysiological an biocemical mechanixms of the neural modifia by learint.

• Korean Journal of Cognitive Science
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• v.9 no.1
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• pp.1-11
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• 1998

In this paper, the features which are thought to be used by humans based on the psychological experiment of human information processing are applied to character recognition problem. Man will deal with a little large area information as well as pixel by pixel information. Therefore we define the feature that represents a little wide region I information called region feature, and combine the features derived from region feature and pixel by pixel features that have been used by now. The features we used are the result of region feature based preanalysis, mesh with region attributes, cross distance difference and gradient. The training and test data in the experiment are handwritten Korean alphabets, digits and English alphabets, which are trained on neural network using back propagation algorithm and recognition results are 90.27-93.25%, 98.00% and 79.73-85.75%, respectively Experimental results show that the feature we are suggesting in this paper is 1-2% better than UDLRH feature similar in attribute to region feature, and the tendency of misrecognition is more easily acceptable by humans.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.37 no.2A
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• pp.83-94
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• 2012

Various wireless communication devices or network such as WRAN and WLAN will coexist in the TVWS(TV White Space). Because of this coexistence, the wireless devices which use the TVWS have to avoid interfering to not only licensed TV receiver and wireless microphone but also homogeneous or heterogeneous TVBD(TV Band Device)s. In this paper, we propose two frequency sharing methods for the coexistence of WLAN and WRAN in terms of interference reduction and throughput enhancement in both homogeneous and heterogeneous networks. One is the WRAN spectrum etiquette to provide more wide bandwidth for WLAN users and the other is the WLAN frequency selection methods to improve the throughput performance. The simulation results have confirmed the throughput improvement of the proposed methods. Moreover, the proposed methods is also applicable to improve the throughput performance and reduce interference of similar systems working in a cognitive manner.