• Title/Summary/Keyword: Incremental coefficient

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Incremental Best Relay Selection System with Outdated CSI in Rayleigh Fading Channels (레일레이 페이딩 채널에서 CSI 지연을 갖는 증가 최적 릴레이 선택 시스템)

  • Kim, Nam-Soo
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.12 no.5
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    • pp.17-23
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    • 2012
  • Recently, for spectral efficiency and power saving, an incremental best relay selection of a cooperative diversity scheme is proposed. However during the best relay selection process, there may exist a delay between channel estimation and actual data transmission. Consequently, this delay causes outdated channel state information (CSI). We analytically derive the effect of the outdated CSI to an incremental best relay selection diversity scheme. It is noted that the system performance deteriorates with decreasing the value of the correlation coefficient sensitively. When the correlation coefficient reduces from 1 to 0.9, the most performance degradation is denoted. However, the performance degradation is diminished with decreasing the correlation coefficient.

PREDICTION OF AIRCRAFT FLOW FIELD EFFECT BY DIRECT CALCULATION OF INCREMENTAL COEFFICIENTS (증가 계수의 직접 계산법을 이용한 항공기 유동장 효과의 예측)

  • Kim, Eu-Gene;Kwon, Jang-Hyuk
    • 한국전산유체공학회:학술대회논문집
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    • 2006.10a
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    • pp.41-46
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    • 2006
  • When new weapons are introduced, the target points estimation is one of the important objectives in the flight test as well as the safe separation. The prediction methods help to design the flight test schedule. However, the incremental aerodynamic coefficients in the aircraft flow field so-called BSE are difficult to predict. Generally, the semiempirical methods such as the grid methods, IFM and Flow TGP using database are used for estimation of BSE. However, these methods are quasi-steady methods using static aerodynamic loads. Nowadays the time-accurate CFD method is often used to predict the store separation event. In the current process, the incremental aerodynamic coefficients in BSE regime are calculated directly, and the elimination of delta coefficients is checked simultaneously. This stage can be used for the initial condition of Flow TGP with freestream database. Two dimensional supersonic and subsonic store separation problems have been simulated and incremental coefficients are calculated. The results show the time when the store gets out of BSE region.

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The Speaker Identification Using Incremental Learning (Incremental Learning을 이용한 화자 인식)

  • Sim, Kwee-Bo;Heo, Kwang-Seung;Park, Chang-Hyun;Lee, Dong-Wook
    • Journal of the Korean Institute of Intelligent Systems
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    • v.13 no.5
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    • pp.576-581
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    • 2003
  • Speech signal has the features of speakers. In this paper, we propose the speaker identification system which use the incremental learning based on neural network. Recorded speech signal through the Mic is passed the end detection and is divided voiced signal and unvoiced signal. The extracted 12 order cpestrum are used the input data for neural network. Incremental learning is the learning algorithm that the learned weights are remembered and only the new weights, that is created as adding new speaker, are trained. The architecture of neural network is extended with the number of speakers. So, this system can learn without the restricted number of speakers.

Strain-rate-dependent consolidation characteristics of Busan clay (부산점토의 변형률 속도 의존적인 압밀특성)

  • Kim, Yun-Tae;Jo, Sang-Chan;Jo, Gi-Young
    • Proceedings of the Korean Geotechical Society Conference
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    • 2005.03a
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    • pp.240-247
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    • 2005
  • In order to analyze effects of strain rate on consolidation characteristics on Busan clay, a series of constant rate of strain(CRS) consolidation tests with different strain rate and incremental loading test(ILT) were performed. From experimental test results, it was found that the preconsolidation pressure was dependent on the corresponding strain rate occurred during consolidation process. Also, consolidation curves normalized with respect to preconsolidation pressure gave a unique stress-strain curve. Coefficient of consolidation and permeability estimated from CRS test had a tendancy to converge to a certain value at normally consolidated range regardless of strain rate. An increase in excess pore pressure without change of total stress was noted on the incremental loading test after the end of loading.

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ABEP Performance of ISDF Relaying M2M Cooperative Networks

  • Xu, Lingwei;Wang, Jingjing;Wang, Han;Gulliver, T. Aaron
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.10 no.12
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    • pp.5129-5148
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    • 2016
  • In this paper, the average bit error probability (ABEP) performance of the incremental-selective decode-and-forward (ISDF) relaying mobile-to-mobile (M2M) cooperative networks over N-Nakagami fading channels is investigated. The exact ABEP expressions are derived, and the power allocation problem is formulated.The derived ABEP expressions are verified by Monte Carlo simulations. The simulation results showed that the propagation parameters, such as the fading coefficient, and the power-allocation parameter, have a significant influence on the ABEP performance.

Performance Analysis of IDF Relaying M2M Cooperative Networks over N-Nakagami Fading Channels

  • Xu, Lingwei;Zhang, Hao;Gulliver, T. Aaron
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.9 no.10
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    • pp.3983-4001
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    • 2015
  • Exact average bit error probability (BEP) expressions for mobile-relay-based mobile-to-mobile (M2M) cooperative networks with incremental decode-and-forward (IDF) relaying over N-Nakagami fading channels are derived in this paper. The average BEP performance under different conditions is evaluated numerically to confirm the accuracy of the analysis. Results are presented which show that the fading coefficient, the number of cascaded components, the relative geometrical gain, and the power allocation parameter have a significant influence on the average BEP performance.

Thermal Expansion Coefficient Measurement of STS430 by Laser Speckle Interferometry (레이저 스페클간섭법에 의한 STS430의 열팽창계수 측정)

  • 김경석;이항서;정현철;양승필
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2004.10a
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    • pp.29-33
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    • 2004
  • This paper presents ESPI system for the measurement of thermal expansion coefficient of STS430 up to 1,000$^{\circ}C$. Existing methods, strain gauge and moire have the limitation of contact to object and do not supply the coefficient up to 800$^{\circ}C$. There needs to measure the data up to 800$^{\circ}C$, because heat resistant materials have high melting temperature up to 1,000$^{\circ}C$. In previous studies related to thermal strain analysis, the quantitative results are not reported by ESPI at high temperature, yet. In-plane ESPI and vacuum chamber for the reduction of air turbulence and oxidation are designed for the measurement of the coefficient up to 1,000$^{\circ}C$and speckle correlation fringe pattern images are processed by commercial image filtering tool-smoothing, thinning and enhancement- to obtain quantitative results, which is compared with references data. The comparison shows two data are agreed within 4.1% blow 600$^{\circ}C$ however, there is some difference up to 600$^{\circ}C$. Also, the incremental ratio of the coefficient is changed up to 800$^{\circ}C$. The reason is the phase transformation of STS430 probably begins at 800$^{\circ}C$.

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Thermal Expansion Coefficient Measurement of STS430 at High Temperature by In-plane ESPI (In-plane ESPI를 이용한 고온에서 STS430의 열팽창계수 측정)

  • 김경석;강기수;장호섭
    • Journal of the Korean Society for Precision Engineering
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    • v.21 no.11
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    • pp.69-74
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    • 2004
  • This paper presents ESPI system for the measurement of thermal expansion coefficient of STS430 up to 1,00$0^{\circ}C$ . Existing methods, strain gauge and moire have the limitation of contact to object and do not supply the coefficient up to 80$0^{\circ}C$ . There needs to measure the data up to 80$0^{\circ}C$, because heat resistant materials have high melting temperature up to 1,000'E In previous studies related to thermal strain analysis, the quantitative results have not reported by ESPI at high temperature, yet. In-plane ESPI and vacuum chamber for the reduction of air turbulence and oxidation are designed for the measurement of the coefficient up to 1,00$0^{\circ}C$ and speckle correlation fringe pattern images are processed by commercial image filtering tool-smoothing, thinning and enhancement- to obtain quantitative results, which is compared with references data. The comparison shows two data are agreed within 4.1% blow $600^{\circ}C$ however, there is some difference up to $600^{\circ}C$. Also, the incremental ratio of the coefficient is changed up to 80$0^{\circ}C$ . The reason is the phase transformation of STS430 probably begins at 80$0^{\circ}C$

Evaluation of local and global ductility relationships for seismic assessment of regular masonry-infilled reinforced concrete frames using a coefficient-based method

  • Su, R.K.L.;Tang, T.O.;Lee, C.L.
    • Earthquakes and Structures
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    • v.5 no.1
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    • pp.1-22
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    • 2013
  • Soft storey failure mechanism is a common collapse mode for masonry-infilled (MI) reinforced concrete (RC) buildings subjected to severe earthquakes. Simple analytical equations correlating global with local ductility demands are derived from pushover (PO) analyses for seismic assessments of regular MI RC frames, considering the critical interstorey drift ratio, number of storeys and lateral loading configurations. The reliability of the equations is investigated using incremental dynamic analyses for MI RC frames of up to 7 storeys. Using the analytical ductility relationship and a coefficient-based method (CBM), the response spectral accelerations and period shift factors of low-rise MI RC frames are computed. The results are verified through published shake table test results. In general applications, the analytical ductility relationships thus derived can be used to bypass the onerous PO analysis while accurately predicting the local ductility demands for seismic assessment of regular MI RC frames.

Optimal Strain Rate of Unloading-Reloading Cycle in Constant Rate of Strain Consoildation Test (제하-재재하 시 CRS 압밀 시험의 최적 변형률 속도)

  • Park, Ka-Hyun;Yune, Chan-Young;Chung, Choong-Ki
    • Proceedings of the Korean Geotechical Society Conference
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    • 2010.09a
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    • pp.1156-1167
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    • 2010
  • The constant rate of strain (CRS) consolidation test has been widely used to evaluate consolidation characteristics of soils instead of the standard Incremental Loading Test. In practical problems, after the ground improvement, the condition of the soil is over-consolidated. Therefore, it is important to determine the recompression indices and the coefficient of consolidation(or the coefficient of swelling) of unloading-reloading cycle to predict the settlement behavior. However, since standard testing procedures or studies related with strain rate are insufficient especially in unloading-reloading cycle, it is difficult to predict the settlement field behavior accurately from the CRS consolidation test results in spite of its lots of strengths. The several CRS consolidation tests were performed changing the unloading strain rate from 0.2%/hr to 20%/hr with vertical drainage condition using the reconstituted kaolinite sample. For the reconstituted kaolinite sample in CRS consolidation test, the recompression indices are insensitive to the strain rate. It is revealed that the coefficient of consolidation of reloading is affected by the developed pore pressure during unloading. Additionally, the test should be conducted in the positive pore pressure ratio range (3~15%) to obtain the reasonable coefficient of consolidation in the whole range(loading, unloading and reloading).

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