• KSII Transactions on Internet and Information Systems (TIIS)
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• v.14 no.6
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• pp.2709-2734
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• 2020

The growing demand to make wireless data services 5G compatible has necessitated the development of an energy-efficient approach for an effective new wireless environment. In this paper, we first propose a cognitive sensor node (CSN) based game theory for deriving energy via a primary user-transmitted radio frequency signal. Cognitive users' time was segmented into three phases based on a time switching protocol: energy harvest, spectrum sensing and data transmission. The proposed model chooses the optimal energy-harvesting phase as the effected factor. We further propose a distributed energy-harvesting model as a utility function via pricing techniques. The model is a non-cooperative game where players can increase their net benefit in a selfish manner. Here, the price is described as a function pertaining to transmit power, which proves that the proposed energy harvest game includes Nash Equilibrium and is also unique. The best response algorithm is used to achieve the green connection between players. As a result, the results obtained from the proposed model and algorithm show the advantages as well as the effectiveness of the proposed study. Moreover, energy consumption was reduced significantly (12%) compared to the benchmark algorithm because the proposed algorithm succeeded in delivering energy in micro which is much better compared to previous studies. Considering the reduction and improvement in power consumption, we could say the proposed model is suitable for the next wireless environment represented in 5G.

• Journal of the Korean Society of Food Culture
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• v.35 no.2
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• pp.156-166
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• 2020

In this study, 594 questionnaires administered to men and women residing in the capital metropolitan area who work night shifts were analyzed in order to study the effect of health information cognition on healing needs in accordance with the type of food selection criteria of the night worker. The results of confirmatory factor analysis in deriving food selection type identified four categories, a safety seeking type, a food exploratory type, a habitual seeking type, and a rational type, and the cognition types on health information were classified into physical cognition and psychological cognition. The need for healing, which was the investigated factor, was found to have a high correlation between questionnaire items with high reliable consistency. The results of this study were as follows. First, the food selection types of safety seeking type and habitual food seeking type had significant positive effects on the cognitive level of physical health information, and food exploratory type and habitual seeking type had significant positive effects on the cognitive level of psychological health information. In addition, it was shown that food exploratory type and rational type had significant positive effects on healing needs. As a result of this study, it was found that the cognition level of physical and psychological information was different according to food selection type, and the higher the cognitive level, the higher the healing needs. In particular, the result that the level of psychological health information significantly affected healing needs signifies that there is a demand to develop programs and menus that satisfy various needs related to healing and recovery from fatigue. In addition, further interest and study on the health and healing of night workers are required.

• Journal of the Korean Chemical Society
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• v.57 no.5
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• pp.640-655
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• 2013

The purpose of this study is to analyze the cognitive demands level of the description about 'changes of state' and 'kinetic theory' on the 'science 1' textbooks by the 2007 revised curriculum. The three types of curriculum analysis taxonomy have been used to analyze the cognitive demands level of those contents on the 6 kinds of 'science 1' textbooks. The most higher level of cognitive demands about the concepts have been discussed here due to the focus of the concepts. The first, the cognitive demand level about 'three states of substances' depending on the motion of their particles in 6 textbooks is a early formal operational stage because of using by the application of kinetic theory. The second, the cognitive demand level about 'diffusion' and 'evaporation' is a early formal operational stage, because the particles move around faster so they can change their position. The third, the cognitive level of the pressure and volume in a gas is a early formal operational stage because of explaining only phenomena in simple correspondence with formal model of kinetic theory. And simple functional relationships beyond linear on the graph of the volume and pressure of gas, the volume and temperature of gas is also a early formal operational stage. The fourth, the cognitive level of the energy of heat by a change of the state is also a early formal operational stage because kinetic theory picture accepted as providing explanation by the change of the state. And functional relationships beyond linear on the graph of the explanation of boiling point of water in water is also a early formal operational stage.

• School Mathematics
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• v.16 no.3
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• pp.445-469
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• 2014

This study aims to examine secondary mathematics teachers' understanding of the levels of cognitive demand on mathematical tasks suggested in mathematics textbooks. The study also attempts to investigate whether the teachers are able to characterize the tasks accordingly and to change low level tasks to high level ones. For this purpose, we developed a survey and 50 secondary mathematics teachers participated in the survey. The findings from the data analysis suggest that 59 percent of the teachers selected high level tasks as appropriate for achieving the national curricular goals, but about 1/3 of the teachers identified PNC tasks as high level ones. The results also reveal that more than half of the teachers were not able to transform low level into high level tasks and only 4 teachers out of 50 were able to transform successfully. The teachers seem to find difficulty in transforming low level tasks into high level ones.

• Journal of the Korean School Mathematics Society
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• v.14 no.1
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• pp.31-42
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• 2011

The purpose of this study is to explore how elementary mathematics teachers' adaptations of a reform-oriented mathematics curriculum material in the USA, Everyday Mathematics, influence elementary students' opportunities to learn mathematics. I illustrate how elementary mathematics teachers alter the curriculum material and how such alterations influence their students' opportunities to learn mathematics in their mathematics classrooms. Results suggest that the teachers with Everyday Mathematics did not appear to maintain the cognitive demand of mathematical tasks as appeared in the curriculum material, as set up by the teacher, and as enacted in the classrooms. The results also show that the teachers seemed to omit components including important tasks and suggestions in the curriculum material. As a consequence, the students did not have an opportunity to think and understand mathematics conceptually and meaningfully; they were exposed and encouraged to learn mathematics procedurally.

• Korean Journal of Health Education and Promotion
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• v.22 no.2
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• pp.195-213
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• 2005

Objectives: This study aims to determine fostering stress and mental health state that mothers of handicapped children perceive as primary care givers and to analyze their demand for information assistance in order to release their stress so that it can provide materials that contribute to establishment of assistance system for families with handicapped children. Methods: The research subjects were 340 mothers whose children went to a nursery for special children, 3 general nurseries and 6 special schools in Daegu, and the data were collected using structures questionnaires. The survey analyzed mothers' fostering stress, their demand for fostering information assistance, children's daily activity abilities. Component concepts of each scale was validated by adopting confirmatory factor analysis, and factors affecting demand for fostering information assistance were analyzed by adopting covariance structural analysis. Results: Younger mothers tend to have higher demand for information, and mothers with younger children or children with double handicaps also have higher demand. Mothers under 30 have the lowest demand for public health and medical care assistance and for home and community life assistance, while mothers with children with physical handicaps have the highest. The validity of component concepts was verified by categorizing as cognitive structure models fostering stress, information demand, children's daily activity abilities, and their appropriateness was evaluated through confirmatory factor analysis using structural equation modelling. And then, GFI (more than 0.9), CFI (more than 0.9), TLI (more than 0.9) and RMSAE (less than 0.08) were used to evaluate the appropriateness. It was found that all the component concepts are valid, as every item is within appropriate range. The result of analyzing information demand demonstrated that children's handicap levels significantly affect their mothers' mental health, while fostering stress significantly affect mothers' metal health, information demand. As well, it was confirmed that mothers' mental health has a significant effect on information demand. Conclusions: Therefore, to reduce special children's mothers' uncertainty, helplessness and fostering burden, it is necessary to provide them with information on children's challenges, development and fostering and to offer them quality public health, medical care and welfare assistance along with family and local community life assistance.

• Korean Journal of Human Ecology
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• v.16 no.6
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• pp.1083-1095
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• 2007

This study had been done to investigate that early childhood teacher's recognition and demand on children's language education and 20 early childhood teachers were interviewed individually who work at state-owned/ public-owned/ private-owned kindergardens residing G, I, and K cities in Jeollabuk-do. First, the purpose of language education was recognized on the formations of essence, concept, expertise, technique and attitude toward language. Second, the contents of language education must be selected by children's experience that they encounter in ordinary life based on oral language and written language. Besides, early childhood teachers strongly felt the necessity of new contents of language education, although they thought of insufficiency of their knowledge on the issue. Third, the method of language education was mainly accomplished by teaching material and objects. Besides, they were aware of looking for new organized teaching methods and also concerned of the importances of teacher's attitude and group formation method. Fourth, the evaluation of language education must be acquired by desirable evaluation method that was based on the recognition of children's unrealistic language capabilities, even though they had recognized the difficulty to do because of knowledge insufficiency. They also showed the tendency of negligence on the evaluation of language education. Fifth, the required facts for early childhood teachers on language education were development and supply of teaching materials, demand on teacher's education and appropriate evaluation method, and cognitive changes on language education by public toward the written language.

• The Journal of the Korea Contents Association
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• v.22 no.7
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• pp.89-101
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• 2022

COVID-19 is significantly changing consumers' demand and habits. In order to understand consumer characteristics and find effective advertising directions in the post-COVID-19 era, this study set young consumers who are more sensitive to market changes and technological transformation from a subjective perspective of advertising audiences. Through the Q methodology, the advertising development model in the post-COVID-19 era was derived exploratively by examining their cognitive status of advertisements in the post-COVID-19 era. The model consists of three types of advertisements: "demand mining online ads" that value consumer demand and adapt to online shopping paths, "added value creation experiential ads" that value derived value and consumer experiences, and "practical and sentimental value creative ads" based on pragmatism and emotional values. In addition, this study also suggested for the sustainable practice of advertising in the post-COVID-19 era in various aspects, such as "seeking multidimensional values," "expanding consumer experience," and "mining and leading demand.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.10 no.6
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• pp.1-8
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• 2010

Wireless multimedia service through the access to mobile telephone network or data network is a vital part of contemporary life, and the demand for frequency spectrum for new services is expected to explode as the ubiquitous computing proliferate. Cognitive radio is a technology, which automatically recognizes and searches for temporally and spatially unused frequency spectrum, then actively determines the communication method, bandwidth, etc. according to the environment, thus utilizing the limited spectrum resources efficiently. In this paper, we investigate the effects of imperfect sensing, misdetection and false alarm, on the primary and secondary users' spectrum usage through the analysis of continuous time Markov Chain. We analyzed the effects of the parameters such as sensing error, offered load on the system performance.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.15 no.1
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• pp.105-110
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• 2015

In cognitive radio networks, when the signal-to-noise ratio (SNR) of the link between a primary transmitter and receiver is sufficiently high, the primary transmission does not frequently demand cooperation because direct transmission of the primary communication is usually successful. Therefore, there are few opportunities for a secondary transmitter to cooperate with the primary user system in exchange for an opportunity to share the spectrum. This article proposes a scheme in which the secondary system can deliberately degrade the SNR of the primary transmission, making it so that the primary system needs cooperation from the secondary nodes, and thereby increases opportunities for spectrum sharing.