• 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.

• Education of Primary School Mathematics
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• v.20 no.2
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• pp.143-151
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• 2017

An increasing number of students are giving up on learning mathematics at all grade levels, including elementary school. The study in this paper considers seven non-cognitive student characteristics to identify which are strongly correlated with giving up on mathematics at the elementary school level. Data were collected with a survey on the non-cognitive domain of mathematics learning that was developed by the Korea Foundation for the Advancement of Science and Creativity in 2015. The data were collected from 3,636 elementary school students in Korea, and we analyzed the data using the statistical computing program R. Of the seven components, efficacy and interest have a strong correlation with students' tendency to profess that they have given up trying to learn mathematics. The findings of the study shed light on which non-cognitive domain areas mathematics teachers need to pay more attention to in order to make their teaching effective. This study further investigated the correlation between responses to each of the 24 survey items and students' claim that they have given up on mathematics. Using the 8 items with the highest correlations, we have developed a shorter, 8-item version of the survey, which will be useful for similar future studies.

• Journal of the Korea Convergence Society
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• v.13 no.4
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• pp.71-78
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• 2022

Parkinson's disease (PD) is clinically characterized by a variety of motor and non-motor symptoms, including cognitive and neuropsychiatric symptoms. Integrating a large variety of symptoms into a small number of clinical subtypes could be valuable for appropriate and early therapeutic intervention. As a first step toward this aim, this study attempted to identify correlation patterns among motor, cognitive and neuropsychiatric symptoms in PD without dementia. One hundred four non-demented patients with PD underwent a comprehensive motor, neuropsychological, and neuropsychiatric assessments. Factor analysis was performed to identify correlation patterns among demographic, motor, cognitive and neuropsychiatric variables. The eight factors were extracted: 1 motor-related, 3 cognitive-related and 4 neuropsychiatric factors. We indentified that characteristics of correlation can have associated symptom pattern in the disease process of Parkinson's disease. The current results suggest that a broad range of motor and non-motor symptoms in PD may be reducible to a small number of clinical parameters, which may be useful for identifying clinical subtypes of PD for individual patients.

• Journal of Industrial Convergence
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• v.20 no.10
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• pp.39-49
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• 2022

The purpose of this study was to systematic review about randomized controlled trials the characteristics and effect of non-pharmacological intervention on depressive symptom in elderly with mild cognitive impairment. We searched studies published from January 2011 to July 2021 in 3 databases. A total 1,455 studies were found and included 11 studies in final analysis. Methodological quality was assessment with the Cochrane's RoB(risk of bias) tool. Geriatric Depression Scale(GDS) was the most used as the assessment tool for identifying the depressive symptom. Intervention were yoga, psychosocial intervention, cognitive training, health education, multi-component intervention, game training, aerobic/pulmonary physiotherapy, art therapy, music reminiscence activity, memory specificity training, cognitive stimulation therapy and SWTW(sleep well, think well) program. Among the intervention programs, yoga, multi-component intervention and game training were effective in improving depressive symptom. This study provided a clinical evidence for planning and implementing intervention on depressive symptom in elderly with mild cognitive impairment.

• Journal of Biomedical Engineering Research
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• v.43 no.4
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• pp.185-192
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• 2022

Early detection of mild cognitive impairment can help prevent the progression of dementia. The purpose of this study was to design and validate a machine learning model that automatically differential diagnosed patients with mild cognitive impairment and identified cognitive decline characteristics compared to a control group with normal cognition using resting-state quantitative electroencephalogram (qEEG) with eyes closed. In the first step, a rectified signal was obtained through a preprocessing process that receives a quantitative EEG signal as an input and removes noise through a filter and independent component analysis (ICA). Frequency analysis and non-linear features were extracted from the rectified signal, and the 3067 extracted features were used as input of a linear support vector machine (SVM), a representative algorithm among machine learning algorithms, and classified into mild cognitive impairment patients and normal cognitive adults. As a result of classification analysis of 58 normal cognitive group and 80 patients in mild cognitive impairment, the accuracy of SVM was 86.2%. In patients with mild cognitive impairment, alpha band power was decreased in the frontal lobe, and high beta band power was increased in the frontal lobe compared to the normal cognitive group. Also, the gamma band power of the occipital-parietal lobe was decreased in mild cognitive impairment. These results represented that quantitative EEG can be used as a meaningful biomarker to discriminate cognitive decline.

• Research in Community and Public Health Nursing
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• v.7 no.2
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• pp.216-228
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• 1996

The purposes of this study were to investigate levels of physical, cognitive, and social functioning in institutionalized elderly. The subjects were 78 residents of a nursing home for the elderly in Pusan. The data were collected from June 24th to July 8th, 1996 using interview and observational method. The structured questionnaires developed by Kim, by Kwon & Park, and by researcher were adopted to measure physical, cognitive, and social function, respectively. The data were analyzed using percentages, means, t test, ANOVA, Pearson correlation coefficient, Cronbach's alpha with the SPSS PC programs. The results were summarized as follows: 1. 34.2% of the subjects had a paralysis, strokes 26.3%, hearing impairment 15.9%, vision impairment 11.8%, mental disturbance 11.8%, cognitive disturbance 10.5%. 2. The mean score on the physical function for the subjects was 73.14, and the items with low functioning levels were 'ascending the stairs', 'bathing' in that order. There was no significant difference in physical function according to the following demographic characteristics: sex, age, and education level. 3. 50.0% of subjects was categorized 'definite dementia', 'questionable dementia' 11.5%, 'definite non-dementia' 38.5%. There was a significant difference in cognitive function according to sex, but were no significant differences according to following demographic characteristics: age and education level. 4. The mean score on the social function for the subjects was 17.60. The items with comparatively high score were in simple activities such as 'enjoying talking with his friends', 'watching TV or listening to the radio', and the items with low score were in complex activities such as 'enjoying a hobby',. 'enjoying a game', 'reading the newspaper or book'. There were no significant differences in social function according to sex and age, but was a significant difference according to education level. 5. Social function was positively correlated with both physical function and cognitive function.

• Journal of the military operations research society of Korea
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• v.23 no.2
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• pp.45-71
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• 1997

There has been considerable research recently on uncertainty handling in the fields of artificial intelligence and knowledge-based system. Various numerical and non-numerical methods have been proposed for representing and propagating uncertainty in knowledge-based system. The Bayesian method, the Dempster-Shafer's Evidence Theory, the Certainty Factor model and the Fuzzy Set Theory are most frequently appeared in the knowledge-based system. Each of these four methods views uncertainty from a different perspective and propagates it differently. There is no single method which can handle uncertainty properly in all kinds of knowledge-based systems' domain. Therefore a knowledge-based system will work more effectively when the uncertainty handling method in the system fits to the system's environment. This paper proposed a framework for selecting proper uncertainty handling methods in knowledge-based system with respect to characteristics of problem domain and cognitive styles of experts. A schema with strategic/operational and unstructured/structured classification is employed to differenciate domain. And a schema with systematic/intuitive and preceptive/receptive classification is employed to differenciate experts' cognitive style. The characteristics of uncertainty handling methods are compared with characteristics of problem domains and cognitive styles respectively. Then a proper uncertainty handling method is proposed for each category.

• Journal of Digital Convergence
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• v.19 no.4
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• pp.49-55
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• 2021

This study analyzed the relationship between the characteristics of learners and the achievement level according to the language they learn in programming education for non-major students. The learner's characteristics were set as mastery goal, situaltional interest, cognitive engagement, and self-efficacy for performance, and path analysis was conducted to understand the relationship between the language used and the learning achievement. Situaltional interest and cognitive engagement were found to have an effect on self-efficacy for performace, and self-efficacy for performance had an effect on academic achievement. At this time, the type of programming language to be studied showed a moderating effect on learning achievement. Based on the results of this study, it is suggested that appropriate instruction is needed for each language used in programming lessons for software non-majors.

• Research in Mathematical Education
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• v.12 no.4
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• pp.251-258
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• 2008

This paper deals with factors discriminating mathematically gifted and non-gifted students. Discussion of some characteristics of mathematically gifted students is done in the first session. Several factors distinguish mathematically gifted from the non-gifted students. High mathematical creativity, high intelligence and opinion of teachers are some of the key factors that can be used for discriminating mathematically gifted and non-gifted students. Research studies have revealed that cognitive as well as affective factors will enhance giftedness. In this study the investigator wishes to look in detail about the characteristics of mathematically gifted students and how they can be identified. Anyway, teachers can change environmental factors and maximum outcome of giftedness can be ensured."

• Korean Institute of Interior Design Journal
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• v.19 no.1
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• pp.37-45
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• 2010

Children likes to play and learn by playing at anywhere as a psychological trait. Children's museum is designed for limited age of 'children,' they learn more actively by playing at the museum with interactive display. In this paper, we analyze Movement of Based on the Psychological Characteristics of Children and Analysis of Preferred Experience of Children's Museum according to Piaget's cognitive development process. It is significant study to investigate user's needs space proposal by grasping user's mentality. After itinerary tracking, we found children's preferred and non-preferred experience displays and as a result, we divided children's Museums into three types, M museum is represented by preoperational period, called 'Go around play' type ; Y museum is represented by 'concrete operational period', called 'Smart road play' type ; and H museum is represented by 'formal operational period' called 'Open search play' type. The conclusions are children's cognitive development stages depending on the age discrimination that the development of play, and preferred plays are different by children cognitive development process. In order to take advantage of children playing in the children's museum by taking into account the developmental aspects will have to be designed. Efficient for viewing by age should be different on the basis. This study has shown that, when planning a children's museum, Planners should discriminate the movements of children and analysis of preferred experience of children's museum according to three museum types friendly to children's cognitive development process.