• ETRI Journal
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• v.36 no.4
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• pp.545-553
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• 2014

This paper proposes an algorithm to sense orthogonal frequency-division multiplexing (OFDM) signals in cognitive radio (CR) systems. The basic idea behind this study is when a primary user is occupying a wireless channel, the covariance matrix is non-diagonal because of the time domain cross-correlation of the cyclic prefix (CP). In light of this property, a new decision metric that measures the power of the data found on two minor diagonals in the covariance matrix related to the CP is introduced. The impact of synchronization errors on the signal detection is analyzed. Besides this, a likelihood-ratio test is proposed according to the Neyman-Pearson criterion after deriving probability distribution functions of the decision metric under hypotheses of signal presence and absence. A threshold, subject to the requirement of probability of false alarm, is derived; also the probabilities of detection and false alarm are computed accordingly. Finally, numerical simulations are conducted to demonstrate the effectiveness of the proposed algorithm.

• Journal of Korean Institute of Industrial Engineers
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• v.39 no.3
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• pp.163-171
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• 2013

Various web browsers offer mouse gesture functions because they are convenient input methods. Mouse gestures enable users to move to the previous page or tab without clicking its relevant icon or menu of the web browser. To maximize the efficiency of mouse gestures, they should be designed to match users' mental models. Mental models of human beings are used to make accurate predictions and reactions when certain information has been recognized by humans. This means providing users with appropriate information about mental models will lead to fast understanding and response. A cognitive response test was performed in order to evaluate whether the mouse gestures easily associate with their respective functional meanings or not. After extracting mouse gestures which needed improvement, those were redesigned to reduce cognitive load via sketch maps. The methods presented in this study will be of help for evaluating and designing mouse gestures.

• Cross-Cultural Studies
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• v.32
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• pp.5-28
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• 2013

In this paper, a style-based approach to translating literary texts is introduced and used. The aim of the study is to work out a stylistic approach to translating literary texts from Arabic into English. The approach proposed in the current study is a combination of four major stylistic approaches, namely linguistic stylistics, literary stylistics, affective stylistics and cognitive stylistics. It has been shown from data analysis that by adopting a style-based approach that can draw from the four stylistic approaches, translators, as special text readers, can easily derive a better understanding and appreciation of texts, in particular literary texts. Further, it has been shown that stylistics as an approach is objective in terms of drawing evidence from the text to support the argument for the important stylistic features and their functions. However, it loses some of its objectivity and becomes dependent and subjective.

• Food Science and Industry
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• v.51 no.1
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• pp.61-71
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• 2018

The evaluation of food taste is one of the important activities of human consciousness and it is practiced by sensory analysis using 5 terminal sensorial consciousness among many other functions. These consciousness activities may be conducted by 3 way branching transformation (3-WBT) logic, which choose one out of 3 options under the multi-layered consciousness decision making system. On the basis of this logic, cognitive sensory evaluation (CSE) method was developed to carry out questionnaire survey covering objective and subjective issues during consumption of food for pregnant women. The results of the CSE for several food items was presented with the Table-pattern called CSET covering consciousness factors and their effects on the food consumers.

• Archives of design research
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• v.16 no.2
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• pp.35-48
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• 2003

Home networking technology connects individual home appliances through a wired or wireless network and makes possible new functions that were impossible when they were used independently. However, the new functions must not simply be confusing arrays of functions that are possible to implement, but those absolutely necessary to the users. To develop innovative information appliances with such functions, scenarios were used and played guiding roles in suggesting new product ideas, making design mockups, and producing videos to show natural situations where the products would be used in home of the future. In the phase of suggesting new product ideas, user action scenarios in the home, generated by a team consisting of experts in the fields of cognitive engineering, user interface, computer science, cultural anthropology, interaction design, and product design, helped the team identify user needs and design factors necessary to fulfill those needs and suggest new product ideas from the design factors. In the phase of making design mockups, the procedures of using the products were described in the scenario format. Based on the scenarios the s쇼les and the user interfaces of them were designed. In the phase of producing videos, the interactions between the user and the product were embodied in the course of professional writers'arranging the scenarios of using the products for the scripts of the videos. Videos were produced to show the actual situations where the design mockups would be used in home of the future and the dynamic aspects of interaction design.

• Journal of Korean Elementary Science Education
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• v.37 no.4
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• pp.416-429
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• 2018

In social constructivist teaching, knowledge construction is achieved through learners' collective social interaction. Vygotsky argued that this process is mediated with language use, and the development of higher order thinking is realized through the transition from inter-personal psychological functions to intra-personal psychological functions. In so doing scientific concepts are internalized to learners. This study examined the third grade elementary students' inter/intra-personal psychological functions and their internalization processes during social constructivist teaching plan about strata and fossils. The lessons were designed along with Wells' dialogic inquiry and Leach and Scott's social constructivist teaching-learning sequences. Results showed that a teacher's utterances of talking with questioning to switch attention, creating cognitive disequilibrium, and expanding the width of students' opinions could make effective inter-personal psychological function. In addition, a learner's inner speech expressed into social discourse through talking about personal experiences, comparing epistemic idea with visual representation, or applying to different situation showed his/her intra-personal psychological function. Some cases of learners' internalization through language use could be at the stage of knowledge building and understanding of the spiral of knowing, but not all. Thus it is argued that a teacher's deeper insight into Vygotskian social constructivist teaching can make elementary science classroom teaching more effective in their inter/intra-psychological functions.

• Korean Journal of Psychosomatic Medicine
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• v.27 no.2
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• pp.155-163
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• 2019

Objectives : The aim of this study was to compare severity, neurocognitive functions, and behavioral and psychological symptoms of dementia (BPSD) according to the degree of temporal lobe atrophy (MTA) in Korean patients with dementia due to Alzheimer's disease and mild cognitive impairment due to Alzheimer's disease. Methods : Participants were 114 elderly subjects diagnosed with Alzheimer's disease or mild cognitive impairment in this cross-sectional study. MTA in brain MRI was rated with standardized visual rating scales (Scheltens scale) and the subjects were divided into two groups according to Scheltens scale. Severity was evaluated with Clinical Dementia Rating (CDR) and Global Deterioration Scale (GDS). Neurocognitive functions was evaluated with the Korean version of Short Blessed Test (SBT-K) and the Korean version of the Consortium to Establish a Registry for Alzheimer's Disease assessment packet (CERAD-K). BPSD was evaluated with the Korean version of the Neuropsychiatric Inventory (K-NPI). Independent t-test was performed to compare severity, neurocognitive functions, and BPSD between two groups. Results : The group with high severity of MTA showed significantly lower scores in CDR, SBT-K, MMSE-KC, modified Boston naming test, word list recognition, and word list memory (p<0.05). There were no differences in K-NPI scores between two groups. Conclusions : Severity and neurocognitive functions of dementia had significant positive association with MTA, but BPSD had no association with MTA. Evaluating MTA seems to have potential benefit in diagnosing and treating neurocognitive impairments in the elderly. Further evaluation is needed to confirm the association between certain brain structures and BPSD.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.8
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• pp.294-303
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• 2017

As the elderly population increases, the prevalence of various geriatric chronic diseases and dementia diseases is also rapidly increasing; accordingly, dementia is becoming a major concern of our society. In this study, 48 elderly patients with mild cognitive impairment located in K district were selected from a group of experimental groups in one building and a control group in one building and evaluated for blood homocysteine levels and cognitive function changes after 4,8, and 12 weeks of taking vitamin supplements. The Chi-squared test, Fisher's Exact test, independent t-test, repeated measures ANOVA, contrast test, repeated measures ANCOVA, and Wilks' lambda test were utilized to analyze the data. The results revealed that the cognitive function of the experimental group was significantly higher than that of the control group at 12 weeks (p<0.05), and so, the experimental group higher than that of the control group (p<0.01), the effect of taking vitamins was significantly increased, indicating that homocysteine was decreased relative to the control group. Therefore, vitamin supplements may prevent decreases in cognitive functions and dementia among elderly patients with mild cognitive impairment.

• Therapeutic Science for Rehabilitation
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• v.9 no.4
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• pp.45-54
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• 2020

Objective : The purpose of this study was to identify the relationships among cognitive function, activities of daily living (ADL), participation and quality of life in community-dwelling elderly. Methods : Cognitive function, ADL, participation and quality of life were assessed in the 144 elderly people residing in the community. We used MMSE-K for measuring cognitive function, K-ADL for ADL, K-ACS for participation, and GQOL for quality of life. Results : Cognitive function was significantly correlated with social activity of participation and quality of life (physical health, psychological health, social relations and economic level). ADL was significantly correlated with participation (instrumental ADL, leisure activity) and all sub-areas of quality of life. Social activity of participation were significantly correlated with all subarea of quality of life except physical health. Among the variables, the most relevant variable was leisure activity. Conclusion : It was related to quality of life in the order of participation, ADL, and cognitive function. Among the sub-areas of participation, leisure activity was the most correlated with quality of life. This study, thus, aimed to provide basic data for successful elderly life by examining the correlation between cognitive function, daily life activity, participation and quality of life in community-dwelling elderly.

• Journal of Nutrition and Health
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• v.52 no.5
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• pp.465-474
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• 2019

Purpose: This study examined the association between the serum 25-hydroxyvitamin D concentration and the cognitive functions in Korean elderly. Methods: The subjects were 393 adults aged 60 years or older who participated in the Yangpyeong cohort between July 2009 and August 2010. The subjects were classified into deficiency, insufficiency, or adequacy groups according to the serum 25-hydroxyvitamin D concentration diagnostic criteria suggested by the US Institute of Medicine (IOM). The cognitive function was assessed based on the Korean version of the Mini-Mental State Examination (MMSE-KC). The dietary intake was assessed using the quantitative food frequency questionnaire with 106 food items. Results: The proportions of deficiency, insufficiency, or adequacy in serum 25-hydroxyvitamin D were 6.6%, 44.5%, and 48.9%, respectively. The serum 25-hydroxyvitamin D concentration was significantly higher in men than in women and in outdoor workers than in other occupations. The adequacy group had higher MMSE-KC scores than the other two groups, but not to a significant degree. The proportion of cognitive impairment tended to decrease with increasing serum vitamin D concentration to deficiency, insufficiency, and adequacy (p for trend = 0.029). The deficiency group had a 2.28 times higher risk of cognitive impairment than the adequacy group, but the difference was not statistically significant (OR, 2.28; 95% CI, 0.18 ~ 1.07, p for trend = 0.119). Conclusion: The serum vitamin D concentration tended to be associated with the cognitive function in elderly Koreans living in rural areas. To confirm the associations, further longitudinal studies with large samples were required.