• Journal of Positioning, Navigation, and Timing
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• v.10 no.1
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• pp.43-48
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• 2021

Most existing studies on the wide-area differential global positioning system (WADGPS) used standard positioning service (SPS) receivers in their observation reference stations which provide the central control station global positioning system (GPS) measurements to generate augmentation data. In the present study, it is considered to apply a precise positioning service (PPS) receiver to an observation reference station which is located in the threatened jamming area. Therefore, the reference station network consists of a PPS receiver based observation reference station and SPS receiver based observation reference stations. In this case, to maintain correction performance P1C1 differential code bias (DCB) should be compensated. In this paper, P1C1 DCB estimation algorithm was applied to the PPS/WADGPS system and performance test results using measurements in the Korean Peninsula were presented.

• Proceedings of the KIEE Conference
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• 1994.07a
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• pp.498-501
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• 1994

This paper presents a digital calculation method of instantaneous reactive power component for standby power supply(SPS) system. Reactive current is defined in time domain, calculated instantaneously by using a TMS320C25. The theoretical analysis is verified by the digital simulation and experimental results.

• International Commerce and Information Review
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• v.13 no.3
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• pp.403-431
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• 2011

The environmental issues including domestic measures to protect public life or health are generally easy to bring the tension between the WTO and its member countries. The standard of review, whether de novo review, total deference, or somewhere in between, is largely important in the WTO's adjudicating mechanism because it is closely related to the appropriate balance of power between sovereign nations and the WTO: The multilateral trading regime, through the proper standard of review, could harmoniously operated without interest conflicts among the member countries and at the same time between the WTO and the member countries. Irrespective the important function of the standard of review in the WTO judicial system, applicable standard of review has not been established in the current SPS Agreement. Furthermore, the nature of the SPS Agreement related in scientific factors, such as scientific experiment, data and assessment prevents the WTO's panel from applying consistent standard of review. Considering the judicial demand for the moderate treatment of the case under the SPS Agreement, this paper explores appropriate standard of review applicable the SPS-related environmental measures, particularly, by analysing the recent SPS-related dispute, US-Hormones Suspension.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2002.11a
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• pp.369-374
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• 2002

This paper presented the development trend of UPS and SPS system has focused on large scale system and more convenient system to maintenance and management. In this paper, we proposed low price and high performance SPSs which can de voltage regulation, harmonic reduction, and capable capacity extension in power. These SPSs are composed by two SPSs in their functional structure, one is power control part including voltage regulation and instant voltage compensaton. The others part is web based monitoring and trend management part for more convenient to SPS operator.

• Journal of Powder Materials
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• v.10 no.3
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• pp.168-171
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• 2003

Interpenetrating phase composites of $TiB_2$-Cu system were produced via Spark-Plasma Sintering (SPS) oi nanocomposite powders. Under simultaneous action of pressure, temperature and electric current titanium diboride nanoparticles distributed in copper matrix move, agglomerate and form a fine-grained skeleton. Increasing SPS-temperature and he]ding time promote densification due to local melting of copper matrix When copper melting is avoided the compacts contain 17-20% porosity but titanium diboride skeleton is still formed representing the feature of SPS . High degree of densification and formation of titanium diboride network result in increased hardness of high-temperature SPS-compacts.

• Korean Journal of Materials Research
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• v.20 no.6
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• pp.326-330
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• 2010

$CoSb_3$ Skutterudites materials have high potential for thermoelectric application at mid-temperature range because of their superior thermoelectric properties via control of charge carrier density and substitution of foreign atoms. Improvement of thermoelectric properties is expected for the ternary solid solution developed by substitution of foreign atoms having different valances into the $CoSb_3$ matrix. In this study, ternary solid solutions with a stoichiometry of $Co_{1-x}Ni_xSb_3$ x = 0.01, 0.05, 0.1, 0.2, $CoSb_{3-y}Te_y$, y = 0.1, 0.2, 0.3 were prepared by the Spark Plasma Sintering (SPS) system. Before the SPS synthesis, the ingots were synthesized by vacuum induction melting and followed by annealing. For phase analysis X-ray powder diffraction patterns were checked. All the samples were confirmed as single phase; however, with samples that were more doped than the solubility limit some secondary phases were detected. All the samples doped with Ni and Te atoms showed a negative Seebeck coefficient and their electrical conductivities increased with the doping amount up to the solubility limit. For the samples prepared by SPS the maximum value for dimensionless figure of merit reached 0.26, 0.42 for $Co_{0.9}Ni_{0.1}Sb_3$, $CoSb_{2.8}Te_{0.2}$ at 690 K, respectively. These results show that the SPS method is effective in this system and Ni/Te dopants are also effective for increasing thermoelectric properties of this system.

• Science of Emotion and Sensibility
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• v.10 no.3
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• pp.481-489
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• 2007

The purpose of this study was to investigate whether there were differences in sound quality among telecommunication service providers(SPs). To avoid the influence of brand of SPs and mobile phone manufacturer, a series of structured experiments was planed. Possible source of sound difference were tested such as specific genres of music, contents providers, mp3 players for PC, and mobile phone manufacturers. The results show there are differences of sound quality among telecommunication service providers(SPs). But the difference comes from contents, mobile phone, and MP3 player for PC. The same model of mobile phone from the manufacturer sounded differently depending on telecommunication service providers(SPs). The genre of music did not show consistent difference in sound quality.

• Proceedings of the Korean Information Science Society Conference
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• 2004.04a
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• pp.16-18
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• 2004

Single system image(SSI) have been the mainstay high-performance computing for many years. SSI requires the integration and aggregation of all types of resources in a cluster to present a single interface to users. In this paper, we describe a cluster computing architecture with the concept of single process space(SPS) where all processes share a uniform process identification scheme. With SPS, a process on any node can create child process on the same or different node or communicate with any other process on a remote node, as if they are on a single node. For this purpose, SPS is built with the support of unique cluster-wide pid, signal forwarding, and remote fork. We propose a novel design of SPS cluster which addresses the scalability and flexibility problem of traditional clusterwidely unique pid implementation by using blocked pid assignment. We have implemented this new design of SPS cluster, and we demonstrate its performance by comparing it to Beowulf distributed process space. Benchmark performance results show that our design of SPS cluster realized both scalability and flexibility that are essential to building SPS cluster.

• Korean Journal of Social Welfare
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• v.50
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• pp.235-263
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• 2002

The present study is designed to explore restructuring direction of the old-age income maintenance system and development direction of the Seniority Pension Scheme(SPS) in Korea. While the SPS is trifling scheme with tiny benefit amount and small budget, the SPS has important role that function as only public income maintenance scheme for both the low income class and the excluded from public pension and public assistance at present stage because of immature National Pension. This study starts with the research question why serious mis-matching problem between needs and resources in old-age income maintenance system occur. Thus this study explores fundamental change direction of the old-age income maintenance system which is coincide with further situation change(demography, labour market, family structure). Also this study explores desirable SPS's development direction as taking into account relation with other public old-age income maintenance system. This paper suggests basic direction of old-age income maintenance system as follows: principle of universal and individual security; principle of sustainability; principle of equity. Under general principle, this paper also proposes largely two development scenario of the SPS. The one is to maintain present transitional and provisional scheme with trying scheme's substantiality. The other is to change into permanent old-age income maintenance scheme for the excluded public pension and public assistance. At this point it is the public pension's role that the SPS's development direction is determined. If the public pension keep one pension per one earner as present system, non-contribution pension as present SPS should maintain continuously. However, if the public pension reorganize into basic pension of one pension per one person and earning-related pension, the SPS should be managed temporarily until mature of public pension. Therefore whether the public pension play basic security role for all elderly or not will determine the SPS development direction.

• Proceedings of the KIEE Conference
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• 1997.07b
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• pp.422-424
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• 1997

In this paper, we characterize the whole class of vector fields that can be linearized by a given nominal state transformation and a feedback linearizing controller. The necessary and sufficient condition for a given uncertain vector field to be so-called "completely linearizable by the nominal coordinate transformation" is given in terms of Lie Bracket of uncertain vector fields and some suitable vector fields of the nominal system.