• Journal of KIISE
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• v.45 no.3
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• pp.251-279
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• 2018

Users can experience cybersickness when interacting with virtual reality (VR). The symptoms of cybersickness are similar to those of motion sickness which include eye fatigue, disorientation, and nausea. Despite the longstanding interest of user's discomfort, inconsistent results have been drawn on the underlying mechanisms and solutions of cybersickness. In this study, we propose an integrated view of cybersickness connecting causes of the symptoms, human perception model, and measurements of cybersickness. Cybersickness-related factors of previous research are reorganized into content, hardware, and human factors as well as analyzed in terms of VR fidelity. Also, pros and cons that measure the degree of cybersickness are discussed.

• Journal of Society of Preventive Korean Medicine
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• v.7 no.2
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• pp.107-119
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• 2003

In order to study the preventive effects of hyperlipidemia depending on endogenous and exogenous methods of induction, after observing what happens when Nokyongdaebotang, a strengthening up treatment is orally administrated into the ways that cause hyperlipidemia either by the exogenous hyperlipidemia condition model method, which is the way where you orally administrate the cholesterol that was dissolved in olive oil, or the endogenous hyperlipidemia model method, where it uses the injecting the Triton WR-1339 vein method, or to the already inducted white rats, the following conclusions could be drawn. 1. The endogenous induction method, cholesterol diet, helps preventing Total Cholesterol, TG, and LDL-Cholesterol, Free Fatty Acid, Phospholipid's augmentation within the blood in the white rats that is being induced or just inducted with hyperlipidemia 2. The exogenous induction method, Triton WR injection, helps preventing Total Cholesterol, TG, and LDL-Cholesterol, Free Fatty Acid, Phospholipid's augmentation within the blood in the white rats that is being induced or just inducted with hyperlipidemia 3. The HDL-Cholesterol did not increase in regard. This is considered to be because when the geological features the HDL-Cholesterol increases proportionally. In deference to the above results, Nokyongdaebotang, which strengthens the vitality, showed that it helps prevent white rats that is being induced or just inducted with hyperlipidemia no matter whether it is endogenous or exogenous.

• Journal of The Korean Society of Agricultural Engineers
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• v.62 no.5
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• pp.63-72
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• 2020

Solar-sharing, which is an agricultural photovoltaic system installing solar panels on the upper part of crop growing field, has especially drawn attention. Because paddy fields for cultivating crops are large flat areas, there have been various attempts to utilize solar energy for solar photovoltaic as well as growth of crops in agriculture. Solar-sharing was first proposed in Japan, and has been actively studied for optimization and practical uses. The domestic climate differs from the climate conditions in which the solar-sharing has been widely studied, therefore, it is required to develop the solar-sharing technology suitable for the domestic climate. In this study, a simulation model was developed to analyze the change of solar radiation resulted from the solar-sharing installation. Monthly solar illumination intensity and the change of illumination intensity according to the various conditions of solar panel installation were simulated. The results of monthly illumination analysis differed by altitude of the sun, which was related to season. In addition, it was analyzed that the monthly illumination decreased by up to 42% due to solar-sharing. Accordingly, it is recommended that solar-sharing should be installed as a way to maximize the efficiency of solar photovoltaic system while minimizing the decrease in solar radiation reaching the crops.

• Journal of the Korean Home Economics Association
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• v.45 no.2
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• pp.1-22
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• 2007

The purpose of this study was to investigate the effect of mother's characteristics, mediated by disciplinary methods and young children's emotional regulation, on young children's aggression. Subjects of this study consisted of 342 young children drawn from seven preschools in Cheongju city. The pilot study was used to examine the applicability of survey instrument. Data were analyzed by the method of frequency, percentage, Cronbach' ${\alpha}$, factor analysis, T-test. F-test, and Duncan post-hoc test using SPSSWIN program. The test of model was done with analysis of correlational matrix in LISREL VII package using a maximum likehood estimation. The results of this research were as follows: First, there were statistically significant differences in mother's characteristics consisting of neurosis symptom and extroversions, disciplinary methods consisting of coercive-punishment and indifferent-irresponsibility, young children's emotional regulation, and young children's aggression consisting of relation and overtness according to some socio-demographic variables. Girls had the higher emotional regulation than boys. Second, the direct effects of disciplinary methods and emotional regulation on boys' aggression were different in between relational and overt aggression. Third, the variables predicting boys' emotional regulation directly were the same in both relational and overt aggression. Forth, the direct effect of mother's characteristics on disciplinary methods was different in between coercive-punishment and indifferent-irresponsibility. Fifth, the indirect effects of mother's characteristics, mediated by disciplinary methods and young children's emotional regulation, on young children's aggression were partly supported in this study. Sixth, the theoretical model of the impact of mother's characteristics, disciplinary methods, and young children's emotional regulation on young children's aggression was different according to gender.

• The Journal of Korean Academy of Prosthodontics
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• v.40 no.2
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• pp.156-171
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• 2002

The purpose of this study was to measure and compare the strains produced by screw-tightening implant frameworks fabricated by aye different fabrication methods; (1) one-piece cast using plastic sleeve, (2) one-piece cast using gold cylinder, (3) laser welding, (4) soldering, and (5) electrical discharge machining, and also to measure and compare the strains produced when the order of screw tightening was changed A research model incorporating eighteen strain gages was made to measure the fit of implant frameworks in three dimensions. Three implants aligned in an arc were fixed on the top ends of the L-shape aluminum bars of the research model, and standard abutments were joined to the implants with abutment screws. Five types of implant framework were placed on the abutments and screwed by a torque wrench using 10 Ncm. Under the conditions of this study, the following conclusions were drawn: 1. The electrical discharge machining group showed the smallest magnitude of strain, followed by the soldering group, the laser welding group, the one-piece cast group using gold cylinder, and the one-piece cast group using plastic sleeve. However, among the magnitude of strain for the remaining groups except the electrical discharge machining group, there were not significant differences. 2. When the order of screw tightening was changed, there were not significant differences in the magnitude of strain. 3. In comparison with the electrical discharge machining group, the laser welding group and the one-piece cast groups showed greater horizontal distortion and the soldering group showed greater horizontal and vertical distortion.

• Magazine of the Korean Society of Agricultural Engineers
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• v.30 no.4
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• pp.94-108
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• 1988

The use of geotextile as reinforcing materials in soil structures has become widespread throughout the world. Geotextile reinforcement has been used in retaining walls, roadbed, embankment stabilization and especially reinforcement of soft foundation, and so on, In the past, however, its design and construction have been performed empirically. In this study, laboratory model tests were carried out in order to investigate the effects of geotextile rein- forcement on vertical and horizontal displacement and other characteristics in soft founda- tions. The experiments were executed in eight treatments ;no geotextile between embank - ment and subsoils, and seven geotextiles with different tensile strength. And such factors as the loading conditions, the tensile strength of geotextiles, the ingredient of geotextiles and the elapsed time were investigate in this study. And the analytical method were executed in order to study the stress and behavior of geotextile - reinforced soil structure by the nonlinear elasto - plastic finite element model. The following conclusions were drawn from this study. 1. Geotextile reinforcement reduced the effects of banking loads on subsoils more effectively with the increase of their tensile strength. 2. As the tensile strength of geotextiles was increase, the rate of the initial vertical disp - lacements of loading plate was reduced inverse proportional to loads, Rowever, the effect of loading was reduced when the loads exceed a certain limits, 3. The effect of reinforcement of nonwoven geotextile was 1.5-4.5 times larger than that of the woven geotextile with equivalent tensile strength. 4. The increased bearing capacity and the reduced settlement are proportioned as the tensile strength of geotextile. 5. The settlement at the long time loading were developed almost all, were completed after 10 days and the additional settlement were not developed since then. 6. The nonlinear elasto - plastic finite element method are accurate to predict the stresses and behayior of geotextile - reinforced soil structures.

• Computers and Concrete
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• v.3 no.4
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• pp.235-248
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• 2006

This investigation presents an analysis procedure for simulating the compressive behavior of a rectangular concrete column confined by fiber-reinforced plastic (FRP) under uniaxial load. That is, the entire stress-strain curve can be drawn through the present analysis procedure. The modified Mander's stress-strain model (Mander, et al. 1988) and finite element method are adopted in this analysis procedure. The numerical analysis results are compared with the experimental results to verify the accuracy of the analysis procedure. This study offers a useful analysis procedure of researching the compressive behavior of rectangular concrete columns confined by FRP. Two main parameters, the number of FRP layers and the radius of the round corners of a rectangular column, are investigated. The numerical results show that non-uniform stresses occur and reduce the sectional effective area owing to the geometry of the confined rectangular column. The stresses are concentrated at the corners of the rectangular column. Compressive strength of a rectangular column increases greatly because the number of FRP layers increase. The maximum predicted compressive stress of the rectangular column has approximately 10% error as compared to the experimental results. Comparing the numerical and experimental results demonstrates that the accuracy of this analysis procedure is credible. Besides, the stress-strain curves of the R30 models, which are rectangular concrete column with large radius of round corners, are almost bilinear. This calculated results conform to the expectation and show the present analysis procedure are more suitable than Mander's model (1988) to analyze the compressive behavior of the rectangular concrete column confined by FRP.

• The Journal of the Korea Contents Association
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• v.15 no.2
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• pp.444-454
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• 2015

The purpose of this study is to investigate factors related to use-diffusion of Nscreen service as well as consumers' lifestyle and media usage of Nscreen service, which is fundamentally changing both the competitive landscape for business and the daily lives of consumers. The data of 1,524 consumers used in this study were drawn from the first Korea Media Panel Study in 2012 of Korea Information Society Development Institute. This study categorized adopters depending on the usage rate of contents and the variety of media platforms they used. Consumers using various media platforms enjoyed more categories of contents provided by Nscreen services. The variety of media platforms was useful in grouping users to explain the difference between the groups in terms of lifestyle activities. Based on the factor analysis and cluster analysis based on the consumers' lifestyle to find out different characteristics of each clusters, the result elicited some implications.

• Journal of the Korea Society of Computer and Information
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• v.15 no.6
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• pp.91-99
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• 2010

The purpose of this study is to design and develop an e-mentoring system for full inclusion. Through the literature review of related studies, the e-mentoring performance model was drawn. Based on this model, an e-mentoring system was designed and developed. Especially the horizontal mentoring was mainly considered during the procedure. To evaluate the usability of the system, 2 system managers, 5 mentors, and 5 mentees were chosen and they were interviewed by researchers. Researchers used an interview instrument(10 items) consisting of mentoring support(cognitive support, affective support, adaptability) and technical support(convenience, accuracy, look & feel) categories. On the whole affirmative responses were given in both mentoring support and technical support areas. It can be concluded that the e-mentoring system is very effective in supporting full inclusion. In future it is recommended that several empirical studies of utilizing the e-mentoring should be performed.

• The Journal of Information Systems
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• v.25 no.1
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• pp.75-104
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• 2016

Purpose The business ecosystem perspective offers a new lens in which to view customers. Customers as the member of business ecosystems influence firms by participating in both the firm level activities and the business ecosystem level activities. For example, customers participate in the business ecosystems by forming interest groups, allowing their voice to be heard the within business ecosystems. Customers can also, turn public opinion around and foster the business ecosystems favorable to firms. On the other hand, as an extreme case of customer participation, customers can engage in community activities to boycott the purchase of products or services from certain firms or business ecosystems. Design/methodology/approach This study views content creation and feedback activities as customer participation in the firm level. On the other hand, word-of-mouth (WOM) and boycott activities are considered as customer participation in the business ecosystem level. This study presents a research model regarding the relationships among customer socialization, customer participation, and psychological ownership. The proposed model is validated through an empirical analysis on online platform business ecosystems. Findings When the two business ecosystems are compared, different results were drawn. In the Facebook ecosystem, boycott and psychological ownership did not have a significant relationship. However, in the Kakao ecosystem, the two had a significant positive relationship. The mediating effect of the business ecosystem type sheds a light on the mission, purpose, vision, and other values associated with the theory of the business on the customer-firm relationship. Further implications for theory and practice were discussed in this study.