• Title/Summary/Keyword: comparable study

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A Study on the Wind Estimation for Unmanned Parafoil System (무인 파라포일 시스템을 위한 바람 추정 기법 연구)

  • Kim, Tae-Wook;Song, Yong-Kyu
    • Journal of the Korean Society for Aviation and Aeronautics
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    • v.23 no.1
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    • pp.8-13
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    • 2015
  • In this paper, a simple algorithm is proposed to estimate wind speed and direction which can significantly improve the landing performance of an unmanned parafoil. The proposed algorithm is applied to flight test data along with other known algorithms and the results are compared and discussed. The proposed algorithm shows comparable performance while it can still be applied to the parafoil under control.

Some historical aspects of Babylonian Mathematics (바빌로니아수학의 역사적 고찰)

  • Kim, Seong-Suk;Kim, Daniel G.
    • The Journal of Natural Sciences
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    • v.16 no.1
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    • pp.39-48
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    • 2005
  • Many researchers consider the totality of Babylonian mathematics was profoundly elementary, but some of their mathematical knowledge achieved a novel comparable to the Greeks. The aim of this article is to provide a brief overview of the environmental and social background which made mathematical development. Historically, mathematics is always a product of society. So it is valuable to study historical background which have produced mathematics.

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Growth of Korean Breast-Fed and Formula-Fed Infants (모유 영양아와 인공 영양아의 성장)

  • 임현숙
    • Journal of Nutrition and Health
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    • v.26 no.6
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    • pp.783-792
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    • 1993
  • This study examined the difference in growth rate between Korean breast-fed(BF) and formula-fed(FF) infants(n=31) at 1, 2 and 3 months postpartum. The results indicated that the growth rate was comparable between groups, but that of the BF infants tended to be slow during the first three months. The intakes of energy, protein and lipid except lactose of the FF infants were greater than those of the BF infants, however the difference in growth rate did not correlate to these variables. But these results suggest that the availability of nutrients might be different between the BF infants and the FF infants.

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Discharge characteristics of MgO layer prepared via aqueous solution process

  • Choi, Hak-Nyun;Kim, Yong-Seog
    • 한국정보디스플레이학회:학술대회논문집
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    • 2006.08a
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    • pp.379-382
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    • 2006
  • In this study, an attempt was made to form magnesium oxide layer via aqueous solution route of salt precipitation process. A layer with flake morphology was formed from the process and various dopants were added during the forming process. The films formed were characterized using SEM, XRD, and cathodoluminescence measurement. In addition, the discharge characteristics were evaluated using panel tests. The results indicate that MgO film can be formed via the aqueous solution process successfully, of which characteristics are comparable to those of MgO film formed by e-beam evaporation process.

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Real-time Aircraft Parameter Estimation using LWR

  • Song,Yongkyu;Hong, Sung-Kyung
    • 제어로봇시스템학회:학술대회논문집
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    • 2001.10a
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    • pp.141.4-141
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    • 2001
  • In this paper the Local Weighted Regression LWR technique is applied to the estimation of aircrcraft parameters. The method consists In improving the Local Weighted Regression LWR technique by adding a data Retention-and-Deletion RD strategy. The improvement comes with reduced computational effort since the two techniques can share their main computational procedures. The purpose of the study was to establish if the proposed algorithm could provide fast and reliable real-time estimations, with accuracy comparable to other well-known off-line identification schemes. The algorithm was tested using specific parameter estimation maneuvers and flight data of the NASA F/A-18 HARV. The results were compared with both the estimation obtained from ...

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Environmental factors regulating the expression of Porphyromonas gingivalis heat shock protein (Porphyromonas gingivalis의 열충격단백 발현조절 환경인자에 관한 연구)

  • Choi, Jeom-Il
    • Journal of Periodontal and Implant Science
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    • v.34 no.1
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    • pp.29-33
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    • 2004
  • The present study was done to evaluate the environmental factors responsible for the expression of Porphyromonas gingivalis heat shock protein. The intensity of the heat shock protein gene expression was comparable to those seen by the heat shock ptreatment of the bacteria $(44^{\circ}C)$ when the bacteria was grown as a mixed culture or biofilm state at $37^{\circ}C$.

Experimental investigation of the Rotating Cryogenic System (회전하는 극저온 시스템의 단열 특성에 관한 실험적 연구)

  • 이창규;정상권
    • Proceedings of the Korea Institute of Applied Superconductivity and Cryogenics Conference
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    • 2000.02a
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    • pp.63-66
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    • 2000
  • A rotating cryogenic system was designed similar to the cooling system for the rotor of a superconducting generator. The experimental rotor has an inner vessel which simulates the winding space of an actual superconducting rotor, and a torque tube of comparable design. This paper describes the evaluation of the total heat leak into the inner vessel that leads to the study of the jheat transfer characteristic of the rotating cryogenic system.

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A Study on the Development of High Performance Grinding Wheel for the Difficult-to-Grind Materials (난삭재의 고능률 연삭을 위한 연삭숫돌의 개발에 관한 연구)

  • 조기수;이종한;손기락
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 1995.04b
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    • pp.118-123
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    • 1995
  • A new grindignwheel was developed for the high performance gfinding of difficult-to-grind materials. Te grinding performance (such as grinding forces, grinding ratio, and surface roughness of ground surface) of the newly developed wheel was evaluated through experiments. Experimental results show that the performance of the newly developed wheel is superior to conventional alumina wheel and comparable to the S-G wheel.

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Routing and Forwarding with Flexible Addressing

  • Poutievski, Leonid B.;Calvert, Kenneth L.;Griffioen, James N.
    • Journal of Communications and Networks
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    • v.9 no.4
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    • pp.383-393
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    • 2007
  • We present a new network-layer architecture that provides generalized addressing. The forwarding infrastructure is independent of the addressing architecture, so multiple addressing architectures can be used simultaneously. We compare our solution with the existing Internet protocols for unicast and multicast services, given the address assignment used in the Internet. By means of an extensive simulation study, we determine the range of parameters for which the overhead costs(delay, state, and network load) of our service are comparable to those of the Internet.

Study on the Optimization of LDD MOSFET (LDD MOSFET의 최적화에 관한 연구)

  • Dal Soo Kim
    • Journal of the Korean Institute of Telematics and Electronics
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    • v.24 no.3
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    • pp.478-485
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    • 1987
  • Optimization of the sub-micron N-channel MOSFET with the LDD(Lightly Doped Drain)structure has been investigated. LDD devices with various length of n-region, n-dose and n-implantation species were fabricated for this purpose. It will be shown that LDD devices have lower substrate current by an order of magnitude and higher breakdown voltage than the conventional devices with comparable channel length. Optimized LDD structure has been found when the sidewall thickness is 2500\ulcorner and n-region is phosphorus implantd with the dose of 1.0E13/cm\ulcorner It has been found that transconductance degradation is less than 20%.

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