• KSII Transactions on Internet and Information Systems (TIIS)
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• v.7 no.7
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• pp.1533-1546
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• 2013

Wireless multicast is considered as an effective transmission mode for the future mobile social contact services supported by Long Time Evolution (LTE). Though wireless multicast has an excellent resource efficiency, its performance suffers deterioration from the channel condition and wireless resource availability. Cognitive Radio (CR) and Device to Device (D2D) are two solutions to provide potential resource. However, resource allocation for cognitive wireless multicast based on D2D is still a great challenge for LTE social networks. In this paper, a joint sub-carriers and power allocation model based on D2D for general cognitive radio multicast (CR-D2D-MC) is proposed for Orthogonal Frequency-Division Multiplexing (OFDM) LTE systems. By opportunistically accessing the licensed spectrum, the maximized capacity for multiple cognitive multicast groups is achieved with the condition of the general scenario of imperfect spectrum sensing, the constrains of interference to primary users (PUs) and an upper-bound power of secondary users (SUs) acting as multicast source nodes. Furthermore, the fairness for multicast groups or unicast terminals is guaranteed by setting a lower-bound number of the subcarriers allocated to cognitive multicast groups. Lagrange duality algorithm is adopted to obtain the optimal solution to the proposed CR-D2D-MC model. The simulation results show that the proposed algorithm improves the performance of cognitive multicast groups and achieves a good balance between capacity and fairness.

• Journal of Satellite, Information and Communications
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• v.10 no.3
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• pp.1-5
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• 2015

Recently, RF energy harvesting technology is a promising technology for small-size IoT(Internet of Things) devices such as sensor to resolve battery scarcity problem. When applied to existing cognitive radio networks, this technology can be expected to increase network throughput through the increase of cognitive user's operating time. This paper proposes a optimal channel-selection policy for RF energy harvesting CR networks model where cognitive users in harvesting zone harvest ambient RF energy from transmission by nearby active primary users and the others in non-harvesting zone choose the channel and communicate with their receiver. We consider that primary users and secondary users are distributed as Poisson point processes and contact with their intended receivers at fixed distances. Finally we can derive the optimal frame duration, transmission power and density of secondary user from the proposed model that can maximize the secondary users's throughput under the given several conditions and suggest future directions of research.

• Korean Journal of Culture and Social Issue
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• v.11 no.spc
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• pp.97-115
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• 2005

This study investigated the factors that influence the attitude, trust, and acceptance toward the North Korean residents by South Koreans. Three hundred and ninety-two South Koreans, including 222 with no contact experience with North Korean residents and 170 with contact experience, answered a questionnaire. The experience group included police officers who provide protection and settlement service, labor counsellors, social workers, church people, college classmates and tutors, and teachers in alternative schools for North Korean youths. The results indicated that protecting police officers have highly negative attitudes in both cognitive and affective dimensions and also show low trust and acceptance. Teachers in alternative schools, on the other hand, were found to have both positive and negative cognitive evaluations of North Korean residents, but still maintained positive affect and high trust and acceptance. People with no contact experience had negative affect along with pity, and showed medium level trust and acceptance. The distinctive difference between the police officers and teachers were attributed to the individual characteristics such as authoritarian personality and uncertainty avoidance rather than to the frequency or depth of contact. The most important determinant of trust and acceptance were found to be the affective component. The implications of these findings on the selection and training of interface personnel and peace education were discussed.

• Journal of Satellite, Information and Communications
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• v.10 no.3
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• pp.6-10
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• 2015

RF energy harvesting technology is a promising technology for generating the electrical power from ambient RF signal to operate low-power consumption devices(eg. sensor) in wireless communication networks. This paper, motivated by this and building upon existing CR(Cognitive Radio) network model, proposes a optimal control policy for RF energy harvesting CR networks model where secondary users that have low power consumption harvest ambient RF energy from transmission by nearby active primary users, while periodically sensing and opportunistically accessing the licensed spectrum to the primary user's network. We consider that primary users and secondary users are distributed as Poisson point processes and contact with their intended receivers at fixed distances. Finally we can derive the optimal frame duration, transmission power and density of secondary user from the proposed model that can maximize the secondary users's throughput under the given several conditions and suggest future directions of research.

• Korean Journal of Health Education and Promotion
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• v.20 no.3
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• pp.145-170
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• 2003

The purpose of this study was to clarity the concept of health insensitivity using Hybrid model, which consists of three phases： theoretical, empirical, and analytic. In the theoretical phase, the definitions of health insensitivity were searched in korean dictionary and examples used in the websites because the concept of health insensitivity has never been studied before. Two dimensions of health insensitivity emerged out from this investigation were cognitive and behavioral. And then a working definition of health insensitivity was established. The sub-concepts and related factors of health insensitivity were identified through the extensive reviews of the literature focusing on two dimensions of cognitive and behavioral. In the empirical phase, in order to obtain description of health insensitivity, face-to-face in-depth interviews were conducted with nine persons who are not related to professional health care. Grounded theory approach was applied to analyze these qualitative data. In the final analytic phase, theoretical results and empirical results were analyzed in the integrated way and a theoretical framework of health insensitivity was established. A refined definition of health insensitivity was that decreased health risk perception in cognitive dimension and conduction of the unhealthy behaviors in behavioral dimension. Sub-concepts of decreased health risk perception were optimistic bias and decreased general fear. Sub-concepts of unhealthy behavior were doing health threatening behavior and not doing desirable health behavior. The contact of health information was a causal condition of health insensitivity. Optimistic disposition, health locus of control, and avoidance coping style were intervening conditions of health insensitivity. Three types of health insensitivity were identified： unconcern or ignorance type, optimistic bias type, and cognitive dissonance type. Finally, The implications of these findings for further research and nursing practice are discussed.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.8 no.1
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• pp.91-107
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• 2014

Device-to-device (D2D) communication is an excellent technology to improve the system capacity by sharing the spectrum resources of cellular networks. Multicast service is considered as an effective transmission mode for the future mobile social contact services. Therefore, multicast based on D2D technology can exactly improve the spectrum resource efficiency. How to apply D2D technology to support multicast service is a new issue. In this paper, a resource allocation scheme based on cognitive radio (CR) for D2D underlay multicast communication (CR-DUM) is proposed to improve system performance. In the cognitive cellular system, the D2D users as secondary users employing multicast service form a group and reuse the cellular resources to accomplish a multicast transmission. The proposed scheme includes two steps. First, a channel allocation rule aiming to reduce the interference from cellular networks to receivers in D2D multicast group is proposed. Next, to maximize the total system throughput under the condition of interference and noise impairment, we formulate an optimal transmission power allocation jointly for the cellular and D2D multicast communications. Based on the channel allocation, optimal power solution is in a closed form and achieved by searching from a finite set and the interference between cellular and D2D multicast communication is coordinated. The simulation results show that the proposed method can not only ensure the quality of services (QoS), but also improve the system throughput.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
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• v.8 no.1
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• pp.70-82
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• 1997

Objective：This study was performed to identify and understand the characteristics of adolescents who had a history of police arrest and/or were adjudicated unruly/delinquent by the juvenile court. Method：The study employed a retrospective reivew of coumputer-recorded data set on 210 consecutive admissions to an adolescent psychiatric inpatient unit. Three groups(No Police Contact, N=115；Police Contact Only, N=60；Adjudicated, N=35) were compared on the areas of a) cognitive and educational performance b) emotion：anxiety, depression, suicidality c) personality d) family and life experiences. Standardized assessments were administered to all subjects using WISC-Ⅲ, Kaufman Test of Educational Achievement, Millon Adolescent Personality Inventory, Reynolds Adolescent Depression Scale, Revised-Chilren’s Manifest Anxiety Scale, Suicide Ideation Questionnarie, Suicide Behavior Interive, Life Events Checklist, and Family Environmental Scale. A subgroup of the subjects, 60 cases also received a standardized interview by Child Assessment Schedule. Results：The characteristic findings of the delinquent group(the police contact only and adjudicated subjects combined) included (1) a high rate of adoption, sexual promiscuity, out of home placement, and repeated psychiatric hospitalization, (2) low verbal IQ scores and educational achievements, (3) high impulsivity, low social conformity, and high forcefulness in personality inventory, (4) low activityrecreation orientation and low moral religious emphasis in family environment, (5)a high frequency of adverse life experiences, (6) among 3 groups, the Police Contact Only group showed the lowest depression, anxiety and suicidal ideation scores, (7) a high diagnostic frequency of conduct disorder, ODD, and ADHD. Conclusions：The adolescent psychiatric inpatients with a delinquent history presented with a certain clinical, family, psychometric characteristics that warrant specific clinical intervention strategies for their cognitive deficits, an impulsive personality style, family dysfunction with adverse life experiences and disruptive behavioral disorders, different from the rest of adolescent psychiatric inpatients.

• Journal of Korean Elementary Science Education
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• v.19 no.1
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• pp.131-143
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• 2000

The unit of a buoyant force included in the 7th national science curriculum for 6th grade students. On the contrary, it seldom that students' conception about buoyant phenomena is studied, even though there has been many studies of students' conceptions of basic science contents. The purpose of this study was to survey the elementary school students' conceptions of a buoyant force, to analyze their cognitive levels, and to explore the relationships between them. Sixth grade students (total numbers is 192) were selected .from 5 .lasses in two elementary schools in a local city of Kyungsangdo. They were asked to respond two kinds of test, which are the Logical Thinking Ability (GALT) to investigate students' cognitive levels and the Buoyant Force Questionnaire (BFQ). We developed BFQ test, based on the 7th national science curriculum for 6th grade and the previous researches of a buoyant force. We, qualitatively, analysed students' frequency of responses about a buoyant force and their types of explanation, and, quantitatively, analysed the relationships between cognitive levels and conceptions of a buoyant force with SPSS/ PC 7.0 programmes. The results of cognitive level showed that half of 6th grade students were in the concrete operational stage, 43.2% in the transitional stage, 6.8% in the formal stage. However, their sub-logical thinking abilities in a combinational, conservational, controlling variables, proportional, probability and correlational logic were very fluctuated from 91% to 8%. The results that only 4.8% of elementary students had correct conceptions of a buoyant force suggest that 6th grade students had great difficulties in understanding of that concept. Their difficulties would originated from the frequent common-sense explanations of a buoyant phenomena in terms of the weight or the unique properties or the contact area of an object or with/without air. Furthermore students' explanations, frequently, changed with context of problems of a buoyant force. Scheffe test of quantitative results that elementary students in the concrete level had 50.6% of concept formation in a buoyant force, the transitional level 54.5%, and in the formal operational level 62.8% showed significant differences of conceptions of a buoyant force with cognitive levels. Therefore the concrete operational elementary students had more difficulties of understanding of a buoyant force than the transitional and formal level, which is required to higher cognitive levels. This conclusion have implications that the unit of a buoyant force have to be presented with concrete activities for majority of students who are in concrete and transitional levels.

• Science of Emotion and Sensibility
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• v.21 no.4
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• pp.43-54
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• 2018

The aim of this study is to determine the effect of motion sickness on pupil rhythm. Sixteen volunteers of both genders (8 male, 8 female, mean age $25.67{\pm}2.43$ years) experienced VR contents in both 2D and HMD versions for 15 minutes, and their pupillary rhythms were compared. The irregular pattern of the pupillary rhythms, as demonstrated by increasing mean pupil diameter (mPD) and standard deviation of the pupil diameter (sPD), revealed motion sickness after experiencing HMD condition. The pupillary response is strongly related to the cognitive load, and the motion sickness can be interpreted as a change in the cognitive load caused by the increasing volume of visual information that must be processed and the conflict or inconsistency between different sensory modalities. The method proposed in this study could be a non-contact measurement method for the monitoring of motion sickness using a web-camera rather than previous sensor-based methods.

• Korean Institute of Interior Design Journal
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• v.26 no.3
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• pp.91-100
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• 2017

The rapid growth of Korean-style buffet in recent years has increased the size of corporate investment. Under this circumstance, businesses make various marketing efforts while highlighting the features and advantages of their brands. Against this backdrop, this study aims to understand which space branding has been applied to the Korean-style buffet through case studies and to propose a method of application of space branding to increase sales in an effective manner in the future. First, the research is theoretical examination and case studies with focus on the characteristics of expressions of Korean-style buffet space branding. Basically, upon completion of examining the concept and the characteristics of expressions of the Korean-style buffet and analyzing the concept of space branding, the components of space branding have been reconstructed based on preceding studies on space branding and then have been applied to each brand space. Also, the hands-on experience of the characteristics of expression of the Korean-style buffet with space branding incorporated in it and prepared a checklist via visual inspections. And then, the field surveys based on these examinations and took approach of drawing a conclusion based on the results analysis conducted by using the SPSS statistical program. Through preceding studies, the three components of space branding, that is, sensory element, emotional element, and cognitive element have been reconstructed before proceeding with this study, which has obtained five major findings as a conclusion. First, the sensory element should be given elements differentiated enough to attract consumers' attention along with a sustainable effort to have brand image imprinted in their mind. Second, in terms of emotional element, the study has found that the brand experience oriented toward interest and participation results in higher utility frequency. Third, the study has found that the cognitive element should seek consistency in communicating with consumers with focus on face-to-face contact on the display in space. Fourth, it has been found that arranging independent spaces is necessary to attract consumers' participation. Finally, the study has identified in which location area of buffet the sensory, emotional, and cognitive elements have placed a significant weight.