• The Journal of Korean Institute of Communications and Information Sciences
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• v.39C no.11
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• pp.1132-1138
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• 2014

In this paper, we proposed three types of binomial filter for spectrum sensing in cognitive radio system. Three filters are binomial, negative binomial and composite binomial filters and the frequency responses of their transfer functions are analyzed and the numbers of stages to meet the required attenuation are driven. As a result of performance analysis in terms of the number of stages, negative and composite binomial filters are superior to the binomial filter. Since the proposed three filters have a unified cascaded structure and are easy to be implemented without any multiplier, it is expected that they will have wide applications.

• Korean Institute of Interior Design Journal
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• no.39
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• pp.116-123
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• 2003

The purpose of this study is to demonstrate the relationship between the results of the analysis of the overseas railroad station buildings, which was conducted using the factors of environmental cognition for the purpose of designing an interior environment for the Incheon International Airport Railroad station that will be newly constructed, and the plan that could be applied to the design of interior environment for the airport railroad station. The station with a complex interior space layout and relatively larger space tends to be difficult to predict or forecast passenger's needs or recognition element in approaching stage of intoner environment design since the human's biological memory system is greatly affected by such factors. Cognitive approach at empirical standpoint would possibly create the design, of which elements will Implement the functions of their own as such approach enables necessary information to be structured in a systematical way and manner In implementing interior environment design for such stations to be built for the first time in Korea, behavioral approach based on systematic theory proved to be very crucial. Under such a background, the study was aimed at extracting the assessment elements for interior environment design, then setting the frame of cognitive approach to eventually propose the guideline in approaching to interior environment design.

• Korean Institute of Interior Design Journal
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• v.21 no.5
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• pp.189-199
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• 2012

The interest and expenditure for children is increasing than in the past because the number of nuclear family is growing, the children's space is configured independently in most homes from infancy, therefore, the market of children's furniture is expanding in spite of the reduction in the population of children. There are not many products considering age, gender, and play behavior in children's furniture market in Korea. The bed, desk, chair, and closet for children under 2 years hold a large majority of children's furniture, there are not a lot of preschool children's furniture for the children aged 4 to 7. As the children aged 4 to 7 experience physical, emotional, and cognitive growth at the same time, the space configuration and furniture choice for these children is educationally very important. Therefore, in this study, we present the importance and necessity of playable furniture to promote the physical, social, emotional, linguistic, and cognitive development of the children aged 4 to 7 among preschool children. We found the concept and basic condition of playable furniture to collect the base data for developing playable furniture and provided the basic data for the development of an ideal playable furniture by comparing and analyzing the cases of 157 items of 14 domestic playable furniture companies and 365 items of 30 overseas in aspect of play functions, forms, materials and colors.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.13 no.6
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• pp.2838-2858
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• 2019

Traditional channel models for vehicle-to-vehicle (V2V) communication usually assume fixed velocity in static scattering environment. In the realistic scenarios, however, time-variant velocity for V2V results in non-stationary statistical properties of wireless channels. Dynamic scatterers with random velocities and directions have been always utilized to depict the non-stationary statistical properties of the channel. In this paper, a non-stationary geometry-based cooperative scattering channel model is proposed for multiple-input multiple-output (MIMO) V2V communication systems, where a birth-death process is used to capture the appearance and disappearance dynamic properties of moving scatterers that reflect the time-variant time correlation and Doppler spectrum characteristics. Moreover, our model has more straight and concise to study the impact of the vehicular traffic density on channel characteristics and thus avoid complicated procedure in deriving the analytical expressions of the channel parameters and functions. The numerical results validate our analysis and demonstrate that setting important parameters of our model can appropriately build up more purposeful measurement campaigns in the future.

• Journal of The Korean Society of Clinical Toxicology
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• v.2 no.1
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• pp.31-36
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• 2004

Three workers, field operators in lubricating oil processing of petroleum refinery industry were found unconscious by other worker. One of them who were exposed to an high concentration of H2S was presented with Glasgow Coma Score of 5, severe hypoxemia on arterial blood gas analysis, normal chest radiography, and normal blood pressure. On hospital day 7, his mental state became clear, and neurologic examination showed quadriparesis, profound spasticity, increased tendon reflexes, abnormal Babinski response, and bradykinesia. He was also found to have decreased memory, attention deficits and blunted affect which suggest general cognitive dysfunction, which improved soon. MRI scan showed abnormal signals in both basal ganglia and motor cortex, compatible with clinical findings of motor dysfunction. Neuropsychologic testing showed deficits of cognitive functions. SPECT showed markedly decreased cortical perfusion in frontotemporoparietal area with deep white matter. Another case was recovered completely, but the other expired the next day.

• Korean Journal of Biological Psychiatry
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• v.30 no.1
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• pp.1-6
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• 2023

Many psychiatric disorders are associated with brain functional dysfunctions and neuronal degeneration. According to the research so far, enhanced brain plasticity reduces neurodegeneration and recovers neuronal damage. Brain-derived neurotrophic factor (BDNF) is one of the most extensively studied neurotrophins in the mammalian brain that plays major roles in neuronal survival, development, growth, and maintenance of neurons in brain circuits related to emotion and cognitive function. Also, BDNF plays an important role in brain plasticity, influencing dendritic spines in the hippocampus neurogenesis. Changes in neurogenesis and dendritic density can improve psychiatric symptoms and cognitive functions. BDNF has potent effects on brain plasticity through biochemical mechanisms, cellular signal pathways, and epigenetic changes. There are pharmacological and non-pharmacological interventions to increase the expression of BDNF and enhance brain plasticity. Non-pharmacological interventions such as physical exercise, nutritional change, environmental enrichment, and neuromodulation have biological mechanisms that increase the expression of BDNF and brain plasticity. Non-pharmacological interventions are cost-effective and safe ways to improve psychiatric symptoms.

• The Journal of Korean Physical Therapy
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• v.35 no.6
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• pp.190-194
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• 2023

Purpose: Traumatic brain injury (TBI) refers to brain damage caused by external forces or trauma. TBIs can vary in severity and result from accidents, falls, sports injuries, assaults, or other forms of physical trauma. The prefrontal cortex (PFC) is known have roles in various cognitive functions. We report on a patient with traumatic brain injury who showed prefrontal symptoms after injury of thalamocortical connections between mediodorsal nuclei (MD) of thalamus and PFC. Methods: A 54-year-old, male patient suffered a TBI as a result of a heavy object falling on his head. After onset of TBI, he showed typical symptoms of prefrontal lobe injury, including personality changes, memory impairment, and general cognition problem. The thalamocortical connections between MD and PFC (ventrolateral prefrontal cortex (VLPFC), dorsolateral prefrontal cortex (DLPFC), and obrbitofrontal cortex (OFC)) were reconstructed using diffusion tensor tractography. In terms of fractional anisotropy value, the right thalamocortical connections to the OFC were significantly lower than those of control subjects. Results: The value of mean diffusivity in the right thalamocortical connections to the DLPFC was significantly higher than that of control subjects. By contrast, both VLPFC and left OFC showed significant decrement in the tract volume of thalamocortical connections compared with that of control subjects. Conclusion: We reported on a patient who showed cognitive and neuropsychiatric impairment due to global injury of the thalamocoritcal connections between MD and PFC following TBI.

• Journal of Web Engineering
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• v.19 no.2
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• pp.139-166
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• 2020

The functions, capabilities, and effects produced by the application services of cyber physical systems (CPS) are usually consumed by users performing their daily activities in a variety of environmental conditions. Thus, it is critical to ensure that those systems neither interfere with human activities nor harm the users involved. In this paper, we propose a framework for testing and verifying the safety and reliability of CPS services from the perspectives of CPS environments and users. The framework provides an environmentaware testing method by which the efficiency of testing CPS services can be improved by prioritizing CPS environments and by applying machinelearning techniques. The framework also includes a metric by which we can automate the test of the most effective services that deliver effects from physical devices to users. Additionally, the framework provides a computational model that assesses mental workloads to test whether a CPS service can cause cognitive depletion or contention problems for users. We conducted a series of experiments to show the effectiveness of the proposed approaches for ensuring the safety and reliability of CPS application services during the development and operation phases.

• Fashion & Textile Research Journal
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• v.16 no.6
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• pp.908-920
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• 2014

As social networking service (SNS) users' needs and wants have become more diverse, SNS is designed to provide various services and functions. As a result, an image based SNS with the purpose of sharing various interests has emerged. More and more fashion companies are using image based SNS to use it as a medium to better communicate with their customers. This study investigates the effect of usage motivation of image based SNS with the emotion of pleasure as the mediator and its impact towards flow and brand attitude. In order to verify the research model and to test the proposed hypotheses, we conducted a pilot test on 8 image based SNS heavy users, and followed through with 215 questionnaires which were collected via online survey. The results of this study are as follows. Each usage motivation of image based SNS had significant effect on each pleasure. The visual impact had a positive effect on sensory pleasure and the common interest significantly influenced on user's affective preference. Curating, simplicity and interconnecting had a positive effect on cognitive pleasure. Affective and cognitive pleasures except sensory pleasure positively impacted the user on flow. The cognitive pleasure had a positive effect on the brand attitude. Lastly, flow had a positive effect on the brand attitude. This study is the foundation of the image based SNS academically in the new media research. Furthermore, it suggests managerial implications of a company to provide effective marketing strategy to make the best use of image based SNS.

• 한국HCI학회:학술대회논문집
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• 2006.02a
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• pp.918-925
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• 2006

Recent development of teachable agent provides learners with active roles as knowledge constructors and focuses on the individualization. The aim of this adaptive agent is not only to maximize the learner's cognitive functions but also to enhance the interests and motivation to learn. In order to establish the relationships among user characteristics and response patterns and to extract the algorithm among variables, we measured the individual characteristics and analyzed logs of the teachable agent named KORI (KORea university Intelligent agent) through the student modeling. A correlation analysis was conducted to identify the relationships among individual characteristics, user responses, and learning outcomes. Among hundreds of possible relationships between numerous variables in three dimensions, nine key user responses were extracted, which were highly correlated with either individual characteristics and learning outcomes. The results suggest that certain type of learner responses or the combination of the responses would be useful indices to predict the learners' individual characteristics and ongoing learning outcome. This study proposed a new type of dynamic assessment for individual differences and ongoing cognitive/motivational learning outcomes through the computation of responses without measuring them directly. The construction of individualized student model based on the ongoing response pattern of the user that are highly correlated with the individual differences and learning outcome may be the useful methodology to understand the learner's dynamic change during learning.