• Journal of Family Resource Management and Policy Review
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• v.14 no.4
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• pp.323-340
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• 2010

Many social and environmental changes have emerged due to the increasing size of the aging generation. This study explored the current status of the information leisure activity of the aging generation (computer use activity, internet service participation, social community participation and blogging, UCC, etc.) and the need for serious games among elderly consumers. It analyzed the current status of serious game and information leisure span as determined by experts on elderly care at the aging welfare institute. The research methods involved applying content analysis and focus group interviews. The results were as follows: The elderly are willing to enjoy the internet and economics networks. In particular, economic investment, economic news, health, meetings, and communication are the main internet search categories. The results for serious games are less interesting than those for IT participation. The components of usefulness in terms of serious games, as identified by care experts, are simplicity, a user-friendly interface, efficacy, and certainty in using the game device. Care experts recognize that serious games represent a supplementary device to traditional physical and emotional therapy.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.2 no.3
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• pp.26-33
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• 2003

The term 'High Speed Machining' has been used for many years to describe end milling with small diameter tools at high rotational speeds, typically 10,000-100,000rpm. The process was applied in the aerospace industry for the machining of light alloys, notably aluminum. In recent year, however, the mold and die industry has begun to use the technology for the production of components, including those manufactured from hardened tool steels. With increasing cutting speed used in modern machining operation, the thermal aspects of cutting become more and mole Important. It not only directly influences in rate of tool weal, but also affects machining precision recognized as thermal expansion and the roughness of the surface finish. Hence, one needs to accurately evaluate the rate of cutting heat generation and temperature distributions on the machining surface. To overcome the heat generation, we used to cutting fluid. Cutting fluid plays a roles in metal cutting process. Mechanically coupled effectiveness of cutting fluids affect to friction coefficient at tool-workpiece interface and cutting temperature and chip control, surface finish, tool wear and form accuracy. Through this study, we examined the behavior of heat generation in high-speed machining and the cooling performance of various cooling methods.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.24 no.5 s.176
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• pp.1331-1342
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• 2000

In power generation systems a variety of structural components typically operate at high temperature and pressure. Therefore a life assessment methodology accounting for gradual creep fracture is increasingly needed for these components. The most critical defects in such structure are generally found in the form of semi-elliptical surface cracks in the welded tubular joints. Therefore the analysis of a semi-elliptical surface crack in a plate or a shell is an important problem in engineering fracture mechanics. On this background, via shell/line-spring finite element analyses of such surface cracks in the welded T and L joints under various loadings, we investigate J-integral along the crack front We first develop T and L joints auto mesh generation program providing ABAQUS input file composed of shell/line-spring finite elements. We then further develop a T and L joints life assessment program based on the experimental creep crack growth law and auto mesh generation program in a graphical user interface format Finally the remaining life of T and L joints for various analytical parameters are assessed using the developed life assessment program.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.21 no.4
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• pp.300-304
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• 2008

A novel characterization method was investigated to estimate the trap generation during the program /erase cycles in nand flash memory cell. Utilizing Fowler-Nordheim tunneling current, floating gate potential and oxide electric field, we established a quantitative model which allows the knowledge of threshold voltage (Vth) as a function of either program or erase operation time. Based on our model, the derived results proved that interface trap density (Nit) term is only included in the program operation equation, while both Nit and oxide trap density (Not) term are included in the erase operation equation. The effectiveness of our model was tested using 50 nm nand flash memory cell with floating gate type. Nit and Not were extracted through the analysis of Program/Erase speed with respect to the endurance cycle. Trap generation and cycle numbers showed the power dependency. Finally, with the measurement of the experiment concerning the variation of cell Vth with respect to program/erase cycles, we obtained the novel quantitative model which shows similar results of relationship between experimental values and extracted ones.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.22 no.6
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• pp.70-78
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• 2008

This paper deals with the simulation modeling of PV generation system for its application to utility distribution network PSCAD/EMIDC simulation model is developed for use in studying the effect of the PV generation to the distribution system. Simulation results show that the addition of the PV system improves the voltage profile of the area by decreasing the power flow from the utility substation. Case studies also show that power quality at the load side is also improved via voltage compensation at the load bus.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.08a
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• pp.69-69
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• 2013

In the area of artificial photosynthesis, particularly for the generation of hydrogen form water, much attention has been paid on organic-inorganic hybrid system. Most of all, a dye/TiO2-combined system has been suggested and its potential utility was well manifested. However, due to its complicated nature of charge interactions in between dye and TiO2 -interface there remains a great challenge to establish the charge-activity relationship, per se light driven charge generation and recombination kinetics with respect to the amount of hydrogen produced. Further complexity of that hybrid system has been witnessed when sacrificial donor and aqueous media are considered. To unveil the operating mechanism on such a dye/TiO2-combined system, we have prepared organic dyes suitable to account for the effect of sacrificial donor as well as water interactions, and prepared the typical dye-grafted TiO2 films to investigate charge-activity relationship. Femtosecond flash photolysis clearly defined the dye effects anchored on to the TiO2 platform. In addition, photodynamic data contemplated well to the dye orientation proposed by the DFT calculations. Recent findings provide fundamental understanding on the dye-grafted TiO2 system and establish a firm background how future dye-sensitized organic-inorganic hybrid system can be designed for the light driven hydrogen generation from water.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.43 no.10 s.352
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• pp.34-44
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• 2006

A system-on-a-chip (SoC) design uses pre-verified IP hardware blocks in order to reduce design time. We need interface circuits to connect IPs with different protocols. In SoC design we should design interface circuits frequently and these tasks are somewhat time-consuming and error-prone. So it is necessary to generate the interface circuits automatically. Several studies have been made on generating interface circuits only from the communication protocols of IPs. With existing approaches, it is not easy to generate interface circuits connecting two IPs only from communication protocols: connection between IP with address and W without address, connection between IP with only one port to transfer address/data and IP with different ports for address and data connection between IP that transfer address and data together and IP that transfer only one address with a number of data in a burst. No consideration of various characteristics of IPs and no changed algorithm are responsible for it. In order to solve this problem, the proposed approach categorizes communication protocols of IPs, and takes characteristics matching of IPs into account during the interface synthesis. In experiments, we show that we could correctly generate and verify interface circuits for IPs with different characteristics.

• The Journal of the Korea institute of electronic communication sciences
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• v.9 no.8
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• pp.915-919
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• 2014

Since smart phones are widely used globally, the demand for high-speed mobile communications are increasing. To accommodate the increased communication demand, the next-generation mobile communication services such as LTE-Advanced are deployed. In the LTE-Advanced base stations, the base station schemes of Digital Unit (DU) and Radio Unit (RU) are widely used. Here, the link between DU and RU is called fronthaul link. In the current fronthaul link, a digital optical communication interface is used, which is called Common Public Radio Interface (CPRI). However, the CPRI link cannot support the increased mobile traffic efficiently. Therefore, in this paper, we investigate an alternative technology based on the Radio over Fiber (RoF) to accommodate the increased mobile traffic economically.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.24 no.6B
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• pp.1183-1190
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• 1999

This paper presents an efficient hardware architecture to improve the frame memory interface occupying the largest hardware area together with motion estimator in implementing MPEG-2 video encoder as an ASIC chip. In this architecture, the memory size for internal data buffering and hardware area for frame memory interface control logic are reduced through the efficient memory map organization of the external SDRAM having dual bank and memory access timing optimization between the video encoder and external SDRAM. In this design, 0.5 m, CMOS, TLM (Triple Layer Metal) standard cells are used as design libraries and VHDL simulator and logic synthesis tools are used for hardware design add verification. The hardware emulator modeled by C-language is exploited for various test vector generation and functional verification. The architecture of the improved frame memory interface occupies about 58% less hardware area than the existing architecture[2-3], and it results in the total hardware area reduction up to 24.3%. Thus, the (act that the frame memory interface influences on the whole area of the video encoder severely is presented as a result.

• Journal of KIISE:Software and Applications
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• v.31 no.11
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• pp.1505-1518
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• 2004

We propose an extremely light DDXMI approach for semi-automated integration of both structurally and semantically heterogeneous distributed XML documents. In the proposed prototype, a DDXMI(Distributed Documents XML Metadata Interface) is defined and a user interface generator is developed. The prototype takes sources' DTDs as inputs and generates a friendly graphical user interface for the application users. The user can easily describe the semantic mapping between the integrated virtual database DTD and sources' DTDs through assigning index numbers and specifying associated function names so that the DDXMI based on the mappings is automatically generated. Quilt is selected as the XML query language which processes user queries according to the DDXMI. It is assumed that the application users know what they want from the different sources, that is, they have their own integrated database schema in their mind, and know the semantics of the involved XML databases. A small-size global DTD and a mid-size global DTB are generated to verify the rluery generation and retrieval results with 3 XML document databases, that is, Master/ph.D thesis, research reports, and journal databases. The system has been developed with JavaCC and Java Servelet.