• Korean Journal of Materials Research
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• v.20 no.4
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• pp.210-216
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• 2010

This paper investigates the dependence of a-Si:H/c-Si passivation and heterojunction solar cell performances on various cleaning processes of silicon wafers. It is observed that the passivation quality of a-Si:H thin-films on c-Si wafers depends highly on the initial H-termination properties of the wafer surface. The effective minority carrier lifetime (MCLT) of highly H-terminated wafer is beneficial for obtaining high quality passivation of a-Si:H/c-Si. The wafers passivated by p(n)-doped a-Si:H layers have low MCLT regardless of the initial H-termination quality. On the other hand, the MCLT of wafers incorporating intrinsic (i) a-Si:H as a passivation layer shows sensitive variation with initial cleaning and H-termination schemes. By applying the improved cleaning processes, we can obtain an MCLT of $100{\mu}sec$ after H-termination and above $600{\mu}sec$ after i a-Si:H thin film deposition. By adapting improved cleaning processes and by improving passivation and doped layers, we can fabricate a-Si:H/c-Si heterojunction solar cells with an active area conversion efficiency of 18.42%, which cells have an open circuit voltage of 0.670V, short circuit current of $37.31\;mA/cm^2$ and fill factor of 0.7374. These cells show more than 20% pseudo efficiency measured by Suns-$V_{oc}$ with an elimination of series resistance.

• Korean Journal of Construction Engineering and Management
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• v.12 no.3
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• pp.121-130
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• 2011

Real option values of early termination payment for selected BTO PPI projects are studied using binomial models. Two cases of early termination payments are considered; an option with the condition of private participants' default, and an option without the condition. Values vary depending upon parameter values such as revenues, costs, discount rates, debt ratio, and volatility of revenues. For selected projects, the option values without the default condition are estimated as 1%~7% of total project costs, whereas the option values with the default condition are estimated as 0%~1.89% of total project cost. When actual revenues differ from the forecasted revenues, apparently the option values deviate from the values based upon the forecasted revenues. When actual revenues fall short of the forecasted revenues, the option values increase by a large amount whereas the option values decrease by a small amount in the opposite case. This implies that the option values can be quite bigger than the values based upon the forecasted revenue especially when the revenue forecast uncertainty is large. This study is expected to play an important role in improving the early termination payment option policy of the government in PPI projects in Korea.

• Proceedings of the Korean Society for Language and Information Conference
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• 1996.02a
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• pp.317-326
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• 1996

• Proceedings of the Korean Magnetic Resonance Society Conference
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• 1999.06a
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• pp.37-37
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• 1999

• Proceedings of the KSR Conference
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• 2011.10a
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• pp.1444-1452
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• 2011

At present, Kyungbu high-speed railway is operated with 300km/h, Honam high-speed railway is being constructed with 350km/h, and the development for the overhead contact line system is to be conducted for the next-generation high-speed railway with the speed of 400km/h. It is necessary to set up the specification and criteria for the key parts such as dropper, termination clamp and tension insulator for the 400km/h railway line. In this paper, the specification and the criteria for dropper, termination clamp and tension insulator has been reviewed and proposed in order to secure long-term reliability and stability under the maximum speed of 400km/h. Also, the specification, criteria and international standards for 300km/h class and 350km/h class railway line system and the international standards related with the insulators have been reviewed, compared and analysed.

• Journal of Korea Multimedia Society
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• v.17 no.8
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• pp.961-967
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• 2014

Raptor codes are a class of rateless codes originally designed for binary erasure channels. This paper presents a compact set of mathematical expressions for iterative soft decoding of raptor codes. In addition, an early termination scheme is employed, and it is embedded in a single algorithm with the formula. In the proposed algorithm, the performance is enhanced by adopting iterative decoding, both in each inner and outer code and in the concatenated code itself between the inner and outer codes. At the same time, the complexity is reduced by applying an efficient early termination scheme. Simulation results show that our proposed method can achieve better performance with reduced decoding complexity compared to the conventional schemes.

• Journal of Aerospace System Engineering
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• v.1 no.3
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• pp.37-42
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• 2007

The flight safety system for the satellite launch vehicles is required in order to minimize the risk due to launch vehicle failure. For prompt and reliable decision of flight termination, the flight safety system usually uses multiple sensors to estimate launch vehicle's flight trajectory. In that case, multiple types of observed tracking data makes it difficult to identify the flight termination condition. Therefore, a fusion tracking filter handling the multiple tracking data is necessary for the flight safety system. This research developed a simulation software for generating multiple types of launch vehicle tracking data, and then processed the data with fusion filters.

• Proceedings of the IEEK Conference
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• 2004.08c
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• pp.463-467
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• 2004

A FTS (Flight Termination System) is a system that resides in a flying object such as a rocket, unmanned airplane, helicopter, missile, etc., receives commands from ground stations or detects coordinates automatically, and accomplishes a destruction command in case the object does not follow the presumed orbit. In this paper, we address the implementation of a communication modem for the FTS modem. We present general theory, simulation results using Matlab, and several results on the implementation using VHDL.

• The Transactions of the Korean Institute of Electrical Engineers D
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• v.51 no.9
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• pp.381-388
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• 2002

This paper suggests the activation-only VSIMM estimator, applied mainly to target tracking problems. This algorithm is much simpler and easier to implement than the ordinary VSIMM algorithm. Also the activation-only VSIMM algorithm provides a substantial reduction in computation while having identical performance with the ordinary VSIMM estimator and the FSIMM estimator. More importantly, the drawbacks related to the improper termination and activation inherent to the VSIMM algorithm are eliminated in this algorithm. The performance of this estimator will be shown through a Monte Carlo simulation for maneuvering target tracking in comparison with the FSIMM and the VSIMM.

• Journal of Veterinary Clinics
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• v.21 no.2
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• pp.109-114
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• 2004

The effect of Human Menopausal Gonadotropin(hMG) on the implantation, pregnancy, and the concentration of plasma progesterone were studied in pregnant rats. HMG 75 or 150 IU were administered once on day 1, 2, 3, 4, 9, 12 or 14 of gestation, respectively. Rats were autopsied on day 7 or 18. A single dose of hMG prevented implantation and terminated pregnancy in all of the rats by injecting on either day 1 or day 2 and this abortifacient action was effective 82-98% of pregnant rats on day 3 or 4 and 14-20% on day 9 or 12. Administration of hMG had no effect on termination of pregnancy on day 14. Plasma progesterone concentration by injecting hMG on day 1, 2, 3 or 4 were very decreased.