• Title/Summary/Keyword: hybrid systems

Search Result 2,646, Processing Time 0.027 seconds

Analysis of Electron Transport in InAlAs/InGaAs HBT by Hybride Monte Carlo Simulation (Hybrid Monte Carlo 시뮬레이션에 의한 InAlAs/InGaAs HBT의 전자전송 해석)

  • 송정근;황성범;이경락
    • Electrical & Electronic Materials
    • /
    • v.10 no.9
    • /
    • pp.922-929
    • /
    • 1997
  • As the size of semiconductor devices shrinks in the horizontal as well as vertical dimension it is difficult to estimate the transport-velocity of electron because they drift in non-equilibrium with a few scattering. In this paper HYbrid Monte Carlo simulator which employs the drift-diffusion model for hole-transport and Monte Carlo model for electron-transport in order to reduce the simulation time and increase the accuracy as well has been developed and applied to analyze the electron-transport in InAlAs/InGaAs HBT which is attractive for an ultra high speed active device in high speed optical fiber transmission systems in terms of the velocity and energy distribution as well as cutoff frequency.

  • PDF

A simulation study on operation strategy of residential fuel cell system for cost curtailment (운전비용 절감을 위한 가정용 연료전지 시스템의 운전전략 수립)

  • Hwang, Su-Young;Kim, Min-Jin;Lee, Jin-Ho;Lee, Won-Yong
    • 한국신재생에너지학회:학술대회논문집
    • /
    • 2008.10a
    • /
    • pp.55-58
    • /
    • 2008
  • Residential fuel cell cogeneration systems have gained much interest due to its high efficiency. In this study, we have performed numerical simulation of residential fuel cell cogeneration system which includes a fuel cell/grid hybrid system. The cogeneration system consists of 1kW PEFC, cooling system, inverter/converter and reformer. Several empirical models have been employed for respective components to improve the accuracy of the simulations. The load varies seasonally. The present simulations can successfully predict the characteristics of the hybrid cogeneration system and thus it can be utilized for establishing an optimal operating strategy of the system.

  • PDF

Increasing Secrecy Capacity via Joint Design of Cooperative Beamforming and Jamming

  • Guan, Xinrong;Cai, Yueming;Yang, Weiwei;Cheng, Yunpeng;Hu, Junquan
    • KSII Transactions on Internet and Information Systems (TIIS)
    • /
    • v.6 no.4
    • /
    • pp.1041-1062
    • /
    • 2012
  • In this paper, we propose a hybrid cooperative scheme to improve the secrecy rate for a cooperative network in presence of multiple relays. Each relay node transmits the mixed signal consisting of weighted source signal and intentional noise. The problem of power allocation, the joint design of beamforming and jamming weights are investigated, and an iterative scheme is proposed. It is demonstrated by the numerical results that the proposed hybrid scheme further improves secrecy rate, as compared to traditional cooperative schemes.

Aesthetic characteristics of fashion in the transitional period of the 21st century(Part I) : Qualitative study (21세기로의 전환기에 표현된 패션의 미학적 특성(제1보) : 정성분석을 중심으로)

  • 이봉덕;양숙희
    • Journal of the Korean Society of Clothing and Textiles
    • /
    • v.26 no.11
    • /
    • pp.1649-1659
    • /
    • 2002
  • It is anticipated that, in the 21st century, aesthetic sense will be altered radically with the introduction of new value systems and ethical standards. At the beginning of the 21st century, new aesthetic senses and identities have already emerged and exerted influence to the society, arts and fashion trends. The purpose of this study is to analyze the aesthetic characteristic of the transitional period of the 21st century. This study employed the qualitative analysis and the main aesthetic characteristics of the 21st transitional period were found as hybrid, technicism, neo-retro, new naturalism, and multi-nationalism. The transitional fashion in the 21s1 century mirrors the post-modern trends with diversity and indeterminacy as the basis of changes. It is expected that this pattern will continue to extend persistent and dominant influence to the future fashion industry. In the subsequent study, quantitative analysis wi]1 be conducted to verify the aesthetic characteristics analyzed in this study.

Joint TAS and Power Allocation for IHDAF Relaying M2M Cooperative Networks

  • Xu, Lingwei;Zhang, Hao;Gulliver, T. Aaron
    • KSII Transactions on Internet and Information Systems (TIIS)
    • /
    • v.10 no.5
    • /
    • pp.1957-1975
    • /
    • 2016
  • The outage probability (OP) performance of multiple-relay-based incremental hybrid decode-amplify-forward (IHDAF) relaying mobile-to-mobile (M2M) networks with transmit antenna selection (TAS) over N-Nakagami fading channels is investigated in this paper. The closed-form expressions for approximate OP of the optimal and suboptimal TAS schemes are derived. The power allocation problem is formulated for performance optimization. Then the OP performance under different conditions is evaluated through numerical simulations to verify the analysis. The simulation results showed that optimal TAS scheme has a better OP performance than suboptimal TAS scheme; the power-allocation parameter has an important influence on the OP performance.

Improvement of Minimum MSE Performance in LMS-type Adaptive Equalizers Combined with Genetic Algorithm

  • Kim, Nam-Yong
    • Journal of electromagnetic engineering and science
    • /
    • v.4 no.1
    • /
    • pp.1-7
    • /
    • 2004
  • In this paper the Individual tap - Least Mean Square(IT-LMS) algorithm is applied to the adaptive multipath channel equalization using hybrid-type Genetic Algorithm(GA) for achieving lower minimum Mean Squared Error(MSE). Owing to the global search performance of GA, LMS-type equalizers combined with it have shown preferable performance in both global and local search but those still have unsatisfying minimum MSE performance. In order to lower the minimum MSE we investigated excess MSE of IT-LMS algorithm and applied it to the hybrid GA equalizer. The high convergence rate and lower minimum MSE of the proposed system give us reason to expect that it will perform well in practical multi-path channel equalization systems.

Flexural behavior of reinforced concrete beams strengthened with a hybrid inorganic matrix - steel fiber retrofit system

  • Papakonstantinou, Christos G.;Katakalos, Konstantinos
    • Structural Engineering and Mechanics
    • /
    • v.31 no.5
    • /
    • pp.567-585
    • /
    • 2009
  • The aim of this study was to investigate the flexural behavior of reinforced concrete beams strengthened with a novel strengthening system. Concrete beams were strengthened with a hybrid retrofit system consisting of high strength steel cords impregnated in an inorganic fireproof matrix (Geopolymer). The strengthened reinforced concrete beams along with non-strengthened control beams were tested monotonically under four point bending loading conditions. Moreover, an analytical model is introduced, that can be used to analyze the flexural performance of the strengthened beams. The experimental results indicate that the failure of the strengthened beams was based on the yielding of the reinforcement in the tension face of the beams, followed by a local slippage of the steel cords. The flexural stiffness of the strengthened beams was significantly improved compared to the stiffness of the non-strengthened beams. In conclusion, the strengthening system can provide an effective alternative to commercially available systems.

Hybrid Memory Adaptor for OpenStack Swift Object Storage (OpenStack Swift 객체 스토리지를 위한 하이브리드 메모리 어댑터 설계)

  • Yoon, Su-Kyung;Nah, Jeong Eun
    • Journal of the Semiconductor & Display Technology
    • /
    • v.19 no.3
    • /
    • pp.61-67
    • /
    • 2020
  • This paper is to propose a hybrid memory adaptor using next-generation nonvolatile memory devices such as phase-change memory to improve the performance limitations of OpenStack-based object storage systems. The proposed system aims to improve the performance of the account and container servers for object metadata management. For this, the proposed system consists of locality-based dynamic page buffer, write buffer, and nonvolatile memory modules. Experimental results show that the proposed system improves the hit rate by 5.5% compared to the conventional system.

Isolation of Candidate Nek2-Interating Protein Genes(NIPs)

  • Yu, Jae-Cheol;Jang, Seong-Gi;Ri, Geon-Su
    • Animal cells and systems
    • /
    • v.6 no.2
    • /
    • pp.181-181
    • /
    • 2002
  • Nek2 is a mammalian protein kinase that is structurally homologous to NIMA, a mitotic regulator in Aspergillus nidulans. We recently observed that the Nek2 protein was localized in multiple sites within a cell in a cell cycle state-specific manner. This suggests that Ndk2 is involved in diverse cellular functions during the cell cycle progression. To have a better understanding on cellular functions in which Nek2 participates, we carried out yeast two-hybrid screening and isolated six candidate clones whose products interact with Nek2. Most of Nek2-interacting proteins (NIPs) appear cytoplasmic, suggesting that Nek2 is involved in cellular functions in cytoplasm. Further experiments are under progress to confirm their interactions with Nek2 and to understand their biological significance.

An Application of the Integrated Model of SPC and EPC in Hybrid Industry (하이브리드 산업에서 SPC 와 EPC통합모형의 사례연구)

  • Kim Jong-Gurl;Jung Hae-Woon
    • Proceedings of the Korean Operations and Management Science Society Conference
    • /
    • 2002.05a
    • /
    • pp.960-967
    • /
    • 2002
  • SPC와 EPC의 통합은 연속공정산업에서 성공적으로 사용되고 있다고 널리 인식되어 있다. 그러나, 이산적인 부품 제조공정의 모니터링과 연속 생산공정 모니터링 양쪽 모두를 포함하는 하이브리드(hybrid)산업에서의 이들 기법을 적용하기 위해서는 샘플링비율, 고장감지, 실시간 보정과 공정통제 등에 관한 연구가 필요하다. 본 연구에서는 SPC와 EPCD의 차이를 비교분석하고, 하이브리드 산업에서 SPC와 EPC를 성공적으로 통합하여 제품공정품질관리에 적용하는 사례연구를 제시하고자 한다.

  • PDF