• Biomolecules & Therapeutics
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• v.20 no.4
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• pp.357-370
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• 2012

Radiation therapy, the most commonly used for the treatment of brain tumors, has been shown to be of major significance in tumor control and survival rate of brain tumor patients. About 200,000 patients with brain tumor are treated with either partial large field or whole brain radiation every year in the United States. The use of radiation therapy for treatment of brain tumors, however, may lead to devastating functional deficits in brain several months to years after treatment. In particular, whole brain radiation therapy results in a significant reduction in learning and memory in brain tumor patients as long-term consequences of treatment. Although a number of in vitro and in vivo studies have demonstrated the pathogenesis of radiation-mediated brain injury, the cellular and molecular mechanisms by which radiation induces damage to normal tissue in brain remain largely unknown. Therefore, this review focuses on the pathophysiological mechanisms of whole brain radiation-induced cognitive impairment and the identification of novel therapeutic targets. Specifically, we review the current knowledge about the effects of whole brain radiation on pro-oxidative and pro-inflammatory pathways, matrix metalloproteinases (MMPs)/tissue inhibitors of metalloproteinases (TIMPs) system and extracellular matrix (ECM), and physiological angiogenesis in brain. These studies may provide a foundation for defining a new cellular and molecular basis related to the etiology of cognitive impairment that occurs among patients in response to whole brain radiation therapy. It may also lead to new opportunities for therapeutic interventions for brain tumor patients who are undergoing whole brain radiation therapy.

• Proceedings of the CALSEC Conference
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• 2004.02a
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• pp.134-149
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• 2004

This paper is aimed at proposing a fuzzy inference mechanism to enhancing the quality of cognitive map-based inference. Its main virtue lies in the two mechanisms： (1) a mechanism for avoiding a synchronization problem which is often observed during inference process with traditional cognitive map, and (2) a mechanism for fuzzifying decision maker's subjective judgment. Our proposed fuzzy inference mechanism (FIM) is basically based on the cognitive map stratification algorithm which can stratify a cognitive map into number of strata and then overcome the synchronization problem successfully. Besides, the proposed FIM depends on fuzzy membership function which is administered by decision maker. With an illustrative B2B negotiation problem, we applied the proposed FIM, deducing theoretical and practical implications. Implementation was conducted by Matlab language.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.7 no.2
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• pp.81-91
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• 2008

In mobile wireless communications, there is a new approach that uses the lacking spectrum efficiently. A cognitive radio is a device that can changes its transmitter parameters based on interaction with the environment in which it operates. At present, the wireless communication standard for wireless device contains power-saving modes or energy efficient mechanisms which cuts off the power of transmitter and receiver for power-saving. However, in cognitive radio environment, every device has the Quiet Period for searching channel and existing energy-saving method is not appropriate to be adjust to cognitive radio environment. In this paper, we propose an energy-efficient MAC protocol of mobile device in cognitive radio environment and prove the improvement of proposed method.

• Journal of Gifted/Talented Education
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• v.25 no.4
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• pp.469-491
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• 2015

The present study investigated the inhibition mechanisms of gifted children, which is one of the main executive functions in human cognitive system. The inhibition process was subdivided into cognitive and emotion aspects in order to examine the interplay between these two aspects with respect to inhibition processing. In Experiment 1, word-color Stroop task was used to study the cognitive inhibition process of 100 gifted children(Gender: 62 males, 38 females; Academic grade: 46 Elementary school students, 54 Secondary school students). In addition, emotional Stroop task was utilized in Experiment 2 to examine the effect of emotional component during cognitive inhibition process. Results revealed a significant cognitive cost (i.e., word-color Stroop effect) when participants had to withhold automatic response during cognitive inhibition task in Experiment 1. Such cognitive cost was reduced as the chronological age of the participants increased, with no difference in gender. The results in Experiment 2 showed no significant emotional inhibition cost (i.e., emotional Stroop effect) during cognitive inhibition task, and there was no effect of gender nor age. This suggests that the emotional component conveyed in words did not lead to cognitive bias effects. This study proposes that the cognitive and emotional inhibition processes are seemingly independent mechanisms that engage in complex interactions during inhibition processing of behavioral response.

• The Journal of the Korean dental association
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• v.56 no.4
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• pp.218-230
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• 2018

According to the burst of aged people, researchers have focused on aging-related diseases. Cognitive impairment including Alzheimer's disease (AD), one of the representative diseases related to aging, has no treatment option until now. Recently, it has been revealed that systemic inflammation plays a fundamental role in the pathogenesis of AD. Previous studies have suggested the association between poor oral health and cognitive impairment. Poor oral health can cause dental caries, chronic periodontitis, multiple tooth loss, and poor chewing ability, etc. Especially, periodontitis is a well-known chronic inflammatory disease and affects cognitive impairment directly and indirectly by inflammatory products mediators. Therefore, reduction of pathogenic microbial burden and inflammatory products by treating periodontitis can be a therapeutic modality to prevent cognitive impairment or to slow down the progression of it. Future studies are necessary to elucidate the causal relations and plausible mechanisms between poor oral health and cognitive impairment.

• International Journal of Advanced Culture Technology
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• v.6 no.4
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• pp.309-316
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• 2018

The main purpose of this study is to understand how cognitive factors influence the way people interact with information/information systems, by conducting comprehensive and in-depth literature reviews and a theoretical synthesis of related research. Adaptive systems have been built around an individual user's characteristics, such as interests, preferences, knowledge and goals. Individual differences in the ability to use new information and communication technology have been an important issue in all fields. Performance differences in utilizing new information and communication technology are sufficiently predictable that we can begin to coordinate them. Therefore, it is necessary to understand cognitive mechanisms to explain differences between individuals as well as the levels of performance. The theoretical synthesis from this study can be applied to design intelligent (i.e., human friendly) systems in our everyday lives. Further research should explore optimization design for user, by integrating user's individual traits (such as emotion and intent) and system modules to improve the interactions of human-system in data-driven environments.

• Molecules and Cells
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• v.43 no.7
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• pp.600-606
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• 2020

Numerous physiological processes in nature have multiple oscillations within 24 h, that is, ultradian rhythms. Compared to the circadian rhythm, which has a period of approximately one day, these short oscillations range from seconds to hours, and the mechanisms underlying ultradian rhythms remain largely unknown. This review aims to explore and emphasize the implications of ultradian rhythms and their underlying regulations. Reproduction and developmental processes show ultradian rhythms, and these physiological systems can be regulated by short biological rhythms. Specifically, we recently uncovered synchronized calcium oscillations in the organotypic culture of hypothalamic arcuate nucleus (ARN) kisspeptin neurons that regulate reproduction. Synchronized calcium oscillations were dependent on voltage-gated ion channel-mediated action potentials and were repressed by chemogenetic inhibition, suggesting that the network within the ARN and between the kisspeptin population mediates the oscillation. This minireview describes that ultradian rhythms are a general theme that underlies biological features, with special reference to calcium oscillations in the hypothalamic ARN from a developmental perspective. We expect that more attention to these oscillations might provide insight into physiological or developmental mechanisms, since many oscillatory features in nature still remain to be explored.

• Korean Journal of Psychosomatic Medicine
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• v.4 no.2
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• pp.262-268
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• 1996

It is important not only understanding the underlying psychodynamic mechanism of the somatization but also understanding the somatization as a process where biological and sociocultural factors are acting as maintaining and exaggerating the primary vague somatic symptoms. Recently, among mechanisms of the somatization biological and cognitive aspect became more important than psychodynamics. When the doctors see patients complain physical discomforts without organic foundation, they should give attention to the mechanism of symptom amplification, misinterpretation, individual cognitive characteristics and learned behavior. Psychiatric disorders which show somatic symptoms should be also evaluated. Autonomic dysfunctions linked with stress would give some clues of the mystery of the mind-body relationship.

• Journal of Korea Entertainment Industry Association
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• v.15 no.7
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• pp.137-143
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• 2021

This discussion can be said to be a qualitative study on the possibility of linking communication education for college students and literacy education for Korean language-linked educators based on the theory of interpretation of cognitive meaning of media text containing complex mechanisms. The implicit meaning of media content expression used as an interactive communication strategy will be accepted as a multilateral interpretation according to the individual learner's cognitive environment. If so, how is the general media content meaning intended by the content creator being accepted? These doubts are the starting point for discussion. To solve the problem, I leaned on the experimental pragmatic methodology of cognitive aesthetics and applied a model of relevance of cognitive linguistics to connect learners' creative cognitive environment and present content to find a contrast. As a result of the discussion, it was possible to establish a basic framework for learners to express their subjectivity and creative thinking that could connect the cognitive environment and present content themselves. In particular, active and positive learners also revealed direct descriptive expressions to build a new cognitive environment, such as suggesting a third alternative to argue the ability to question produced media texts and the validity of the meaning implied in the text. In the future, since media text containing complex mechanisms is an indirect and persuasive communication behavior that occurs easily through various media in modern society, the universal communication principle of reliable conversation between media text creators and audiences should exist.

• Korean Journal of Cognitive Science
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• v.10 no.3
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• pp.39-49
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• 1999

The space of IID([ndependently, Identically Distributed) textures was built with axes of mean luminance and contrast, and studied on what kind of mechanisms were required to mediate texture segregation in this space. The conjecture was tested that one of these mechanisms is sensitive to the differences between the means of textures to be discriminated, whereas the other is sensitive to the differences between variances. The probability of discrimination was measured for various pairs of textures in the lID space The data were well fit by a model in which discrimination depends on two mechanisms whose responses are combined by probability summation. The conjecture was rejected that two mechanisms respectively tuned to mean and variance of texture function in segregation. Discrimination within space is mediated by 2 independent channels however: the 2 independent channels are not exactly tuned to texture mean and variance. One m mechanism was primarily sensitive to texture mean, whereas the other was sensitive to b both texture mean and variance.