• Journal of Biomedical Engineering Research
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• v.11 no.2
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• pp.295-304
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• 1990

In order to use for artificial dental tooth (dental crowens) , new glass-ceramics material has been studied. Its basic composition and the condition of heat treatment for crystalization, mechanical and chemical properties were investigated. Adding of the LAS system composition in the basic glass, time and temperature for crystalization were shortened. Fracture toughness (kic)of samples heat treated at 90$0^{\circ}C$ for 2 hours is 2.5-2.6MN/m3/2, the optimum condition of heat treatment for artificial tooth is A and B samples heating to 75$0^{\circ}C$ for 2 hours, raising to 90$0^{\circ}C$ and maintaining at 90$0^{\circ}C$ for 2 hours and C sample heating to 75$0^{\circ}C$ maintaining at 75$0^{\circ}C$ for 2 hours. In acid and'alkali solution, chemical durability is excellent.

• Korean System Dynamics Review
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• v.2 no.1
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• pp.5-28
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• 2001

The advent of Electronic Commerce is raising two hypothetical questions conflicting each other in economic point of view. The one is that cyberspace will eventually resolve the problem of economic disparity by presenting equal opportunities to local companies through the removal of barriers in terms of time and space. The other is that the problem of economic disparity will be amplified by the vicious cycle of reproduction on an enlarged scale residing in the new rules of digital economy. As an initial attempt to tackle the questions listed above, by introducing systems thinking and adopting the systems dynamics simulation technique this paper puts an effort to find some tentative answers to the questions possibly raised about the impact of electronic commerce on local economy on which little research has been conducted so far. The general scheme for the dynamism of systems where two groups of electronic malls compete each other and the findings presented in the paper would perhaps provide some ideas and directions for further study.

• Fibers and Polymers
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• v.1 no.2
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• pp.83-91
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• 2000

Thermotropic liquid crystalline polymer made up of poly(p-hydroxybenzoate) (PHB)-poly(ethylene terephthalate)(PET) 8/2 copolyester, poly(ethylene 2,6-naphthalate) (PEN) and PET were mechanically blended to pursue the liquid crystalline phase of ternary blends. Complex viscosities of blends decreased with increasing temperature and PHB content. DSC thermal analysis indicated that glass transition temperature (Tg) and melting temperature (Tm) of blends increased with increasing PHB content. Both tensile strength and initial modulus increased with raising PHB content and take-up speed of monofilaments. In the WAXS diagram, only PEN crystal reflection at 2Θ=$15.5^{\circ}C$ appeared but PET crystal reflection was not shown in all compositions. The degree of transesterification and randomness of blends increased with blending time but sequential length of both PEN and PET segment decreased.

• Korean Institute of Interior Design Journal
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• no.39
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• pp.37-44
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• 2003

From long time ago, stairs are performed the central role of vertical circulation system in architectural planning for convenience of human. The purpose of this study is to find the spacial characteristics of stairs in architectural space. Two methods In this study are discussed. First, it is to extract the formal elements in its stairs shape raising an impulse of visual-perceptible recognition. Second, it is to analysis its characteristic through relationship between stairs and spacial elements. In conclusion, the characteristics of stairs in architectural space have as follows 1) spatial connection - to connect between space and other space or masses; 2) spatial separation - to separate between inner space and other space; 3) openness or closeness of space; 4) directed-tention of space.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.58 no.11
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• pp.2229-2235
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• 2009

In this paper, each specimen blended at weight proportions of 80% HDPE to 20% EVA, 70% HDPE to 30% EVA, 60% HDPE to 40% EVA, and 50% HDPE to 50% EVA was manufactured respectively. The insulation performances of the proposed insulator were compared with conventional XLPE, main insulating material of CV cable on the basis of the investigation results of DC insulation performances. From the space charge density, electric field and potential profiles with raising DC voltage and time variation in HE82, distortion of electric field distribution was improved. As EVA mixed into the bulks acts as nucleation in crystallization process of HDPE, the size of spherulites became decreased and finally formed continuous network structure. Ultimately, it resulted from extinction of space charge in the interfacial region of spherulites.

• Journal of the Semiconductor & Display Technology
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• v.22 no.4
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• pp.76-80
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• 2023

This study is about a service that allows people to naturally learn to bask in the sun, which is a habit to relieve depression. Modern people do not have enough time to bask in the sun due to their busy lives, and as a result, depression and fatigue are increasing day by day. Therefore, in order to relieve depression, there is a need for the development of technology to manage the schedule of sunlight basking so that users can experience sunlight more naturally. The sunlight service developed through this study can help you easily plan your sunlight schedule by recommending good dates, times, and locations for sunbathing. In addition, users can receive coins as much as they bask in the sun, and they can be motivated by the act of basking in the sun by raising their character with those coins.

• Journal of the Semiconductor & Display Technology
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• v.22 no.4
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• pp.172-178
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• 2023

With the expansion of metaverse content and hardware platforms, various interactions in the virtual world have been built, raising expectations for an increase in immersion which is a major element of the metaverse. However, among hardware platforms that increase virtual immersion elements, the typical HMD platform can be a barrier to new user inflows due to its high cost. Thus, this paper focused on improving virtual-to-real interactions by extracting motion data using relatively inexpensive webcam equipment in PC environments, utilizing Unity game engines, Photon unity network, multi-platform implementations, and Barracuda neural network inference libraries.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.19 no.3
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• pp.14-27
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• 2020

Pedestrian deaths account for a high percentage of deaths in traffic accidents in Korea, raising interest in pedestrian safety policy. However, since the walk signal time is applied based on the length of the crosswalk without considering the walker and the signal cycle, the walk waiting time is relatively longer than the crosswalk, causing pedestrian jaywalking. In this study, due to an unreasonable signal time plan during a road crossing where a signal is installed, the pedestrian's walk signal was given twice a cycle of crossings, and the operational and safety effects of the signal system were quantitatively and qualitatively analyzed, and the operational effects of the signal interval and jaywalking rate were assessed by different signal intervals. The results showed that jaywalking and waiting time decreased, and the shorter the interval between the application of the walk signal time, the less jaywalking is analyzed. However, there is a risk of vehicle conflict due to pedestrian exposure, and measures for expanding safety for operation were proposed.

• The Journal of the Convergence on Culture Technology
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• v.6 no.3
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• pp.211-216
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• 2020

The purpose of this study is to discover about the parenting anxiety of working mother and full-time mother with elementary school children, and to find ways to support them. All the study participants were 20 mothers with elementary school children. Data was collected from June 23, 2017 to July 8, 2017. Data was collected using in-depth group interviews. Parenting anxiety felt by working mothers is 'sorry about the child', 'burden on the role of parents', and 'difficulty in caring', 'Reemployment and career disconnection'. The conclusion is as follows. First, it is necessary to reduce the burden of raising children on elementary school children of both working and full-time mothers. Second, practical support plans are needed for working mothers and full-time mothers of elementary school children. Third, practical support plans are needed for working mothers and full-time mothers with elementary school children.

• Asian Journal of Business Environment
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• v.13 no.2
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• pp.1-7
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• 2023

Purpose: The purpose of the study is to explore the factors which influence the night-time economic development in Hanoi, Vietnam. The results can help policymakers achieve a scientific basis to plan the development of night-time economy in Hanoi. Research design, data and methodology: The research model is developed from literature review with 7 independent variables, including natural conditions and resources, infrastructure, safety, environmental issues, promotion and international integration, development of sharing economy, and institution and policy. This model is then adjusted by exploratory factors analysis to have 4 new variables: Institution and environment, Infrastructure and safety, Promotion and sharing, and Nature and resources. The model is regressed based on the data of 463 observations of night-time economy in Hanoi, Vietnam. Results: Consistent with the current literature addressing night-time economy, the results show positive impacts of all of the independent variables studied. Conclusions: It is recommended for the local authorities to strengthen advertising and promoting investment for NTE development in Hanoi city and also enhance the role of state management in NTE activities by raising awareness of the state management apparatus towards a more open-minded multi-dimensional view of the NTE, developing the NTE to overcome the barrier of thinking "if it cannot be managed, it is forbidden" in state management agencies, and defining responsibilities and authority among state management agencies in the management of NTE activities and strengthening decentralization and decentralization of powers for localities in the management and development of NTE.