• Title/Summary/Keyword: Domain switching

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Advanced LER to Improve Performance of IP over MPLS (IP기반 MPLS망의 성능향상을 위한 Advanced LER)

  • 박성진;김진무;이병호
    • Proceedings of the IEEK Conference
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    • 2000.11a
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    • pp.37-40
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    • 2000
  • Multi Protocol Label Switching (MPLS) is a high performance method for forwarding packets (frames) through a network. It enables routers at the edge of a network to apply simple labels to packets (frames). we use MPLS in the core network for internet. MPLS provide high speed switching and traffic engineering in MPLS domain but at the Label Edge Router(LER) there is frequently cell discarding via congestion and buffer management method. It is one of the most important reasons retransmission and congestion. In this paper we propose advanced LER scheme that provide less cell loss rate also efficient network infrastructure.

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MAC Scheduling Scheme for VoIP Traffic Service in 3G LTE (3G LTE VoIP 트래픽 서비스를 위한 MAC 스케줄링 기법)

  • Jun, Kyung-Koo
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.32 no.6A
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    • pp.558-564
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    • 2007
  • 3G Long Term Evolution, which aims for various mobile multimedia service provision by enhanced wireless interface, proposes VoIP-based voice service through a Packet Switching (PS) domain. As delay and loss-sensitive VoIP traffic flows through the PS domain, more challenging technical difficulties are expected than in Circuit Switching (CS) domain based VoIP services. Moreover, since 3G LTE, which adopts the OFDM as its physical layer, introduces Physical Resource Block (PRB) as a unit for transmission resources, new types of resource management schemes are needed. This paper proposes a PRB scheduling algorithm of MAC layer for VoIP service in 3G LTE and shows the simulation results. The proposed algorithm has two key parts; dynamic activation of VoIP priority mode to satisfy VoIP QoS requirements and adaptive adjustment of the priority mode duration in order to minimize the degradation of resource utilization.

Switching Dynamics Analysis by Various Models of Hf0.5Zr0.5O2 Ferroelectric Thin Films (Hf0.5Zr0.5O2 강유전체 박막의 다양한 분극 스위칭 모델에 의한 동역학 분석)

  • Ahn, Seung-Eon
    • Korean Journal of Materials Research
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    • v.30 no.2
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    • pp.99-104
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    • 2020
  • Recent discoveries of ferroelectric properties in ultrathin doped hafnium oxide (HfO2) have led to the expectation that HfO2 could overcome the shortcomings of perovskite materials and be applied to electron devices such as Fe-Random access memory (RAM), ferroelectric tunnel junction (FTJ) and negative capacitance field effect transistor (NC-FET) device. As research on hafnium oxide ferroelectrics accelerates, several models to analyze the polarization switching characteristics of hafnium oxide ferroelectrics have been proposed from the domain or energy point of view. However, there is still a lack of in-depth consideration of models that can fully express the polarization switching properties of ferroelectrics. In this paper, a Zr-doped HfO2 thin film based metal-ferroelectric-metal (MFM) capacitor was implemented and the polarization switching dynamics, along with the ferroelectric characteristics, of the device were analyzed. In addition, a study was conducted to propose an applicable model of HfO2-based MFM capacitors by applying various ferroelectric switching characteristics models.

Digital Control of Phase-Shifted Full-Bridge PWM Converter

  • Lim, Jeong-Gyu;Chung, Se-Kyo
    • Journal of Power Electronics
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    • v.8 no.3
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    • pp.201-209
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    • 2008
  • This paper presents the modeling and design of a digital controller for a phase-shifted full-bridge converter (PSFBC) in a discrete-time domain. The discretized PSFBC model is first derived and then analyzed considering the sampling effect and the system parameters. Based on this model, the digital controller is directly designed in a discrete-time domain. The simulation and experimental results are provided to show the validity of the proposed modeling and controller design.

Energy barrier of nanomagnet with perpendicular magnetic anisotropy

  • Song, Kyungmi;Lee, Kyung-Jin
    • Proceedings of the Korean Magnestics Society Conference
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    • 2014.05a
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    • pp.120-121
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    • 2014
  • We investigate the field-dependence of energy barrier for various cell diameters and two type of geometry through the NEB method. We find that the energy barrier can depend strongly on the cell size when the switching is governed by the domain wall motion. Moreover we also examine the cell size dependence of energy barrier for two type of cell geometry. In the presentation, we will discuss the effect of domain wall formation and more various cell size on the energy barrier in detail.

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Design of Impulse generator Using Gain-Switched Semiconductor Laser for UWB (반도체 레이저의 이득스위칭을 이용한 UWB 임펄스 발생기 설계)

  • Kwon Soon-young;Kim Bum-in;Park Chong-dae
    • Journal of the Institute of Electronics Engineers of Korea TC
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    • v.42 no.6 s.336
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    • pp.61-66
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    • 2005
  • In this paper, we implemented a impulse generator, the one of the part in UWB(Ultra Wide Band) system using step recovery diode(SRD) and gain-switced semiconductor laser. The impulse generator was consisted of four stages; The first stage used SRD to generate the first impulse for gain switching. The second stage controled current for the suitable gain switching condition. The third was the second impulse generator to generate gaussian pulse. For gain switching, the first impulse was applied to semiconductor laser. In the last stage the gain switched impulse was converted into mono-gaussian pulse. The measured mono-gaussian pulse was 360 psec pulse-width and $-70mV \~ +50mV$ amplitude in time domain. In frequency domain its magnitude and bandwidth was, respectively, -41dBm and 3.6GHz. Accordingly, the impulse generator that we suggested was suitable for UWB systems.

Time-Domain Analog Signal Processing Techniques

  • Kang, Jin-Gyu;Kim, Kyungmin;Yoo, Changsik
    • Journal of Semiconductor Engineering
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    • v.1 no.2
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    • pp.64-73
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    • 2020
  • As CMOS technology scales down, the design of analog signal processing circuit becomes far more difficult because of steadily decreasing supply voltage and smaller intrinsic gain of transistors. With sub-1V supply voltage, the conventional analog signal processing relying on high-gain amplifiers is not an effective solution and different approach has to be sought. One of the promising approaches is "time-domain analog signal processing" which exploits the improving switching speed of transistors in a scaled CMOS technology. In this paper, various time-domain analog signal processing techniques are explained with some experimental results.

Magnetization Reversal Behavior of Submicron-sized Magnetic Films in Response to Sub-ns Longitudinal Field Pulses Along the Easy Axis (1 ns 이하의 자화 용이축 펄스 자기장에 의한 자성박막의 자화 반전 거동)

  • Lee, Jin-Won;Han, Yoon-Sung;Lee, Sang-Ho;Hong, Jong-Ill
    • Journal of the Korean Magnetics Society
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    • v.17 no.5
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    • pp.188-193
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    • 2007
  • We simulated the magnetization reversal behavior of submicron-thickness magnetic films by applying pulses of sub-ns-long durations and amplitudes along the easy axis. The films were rectangular and elliptical $Ni_{80}Fe_{20}$, and their thickness was 2 nm and 4 nm. We observed different behaviors depending upon the shape and thickness of the films and found a normal non-switching in regions in which we expected complete switching after relaxation. In the elliptical film, the non-switching regions were found to be random and to be widely distributed throughout the switching map. The strong demagnetization field along the z-axis, the film thickness direction, is likely responsible for this abnormal behavior. In the rectangular film, the abnormal non-switching regions were less distributed than they were in the elliptical film due to edge domains resulting from the small $M_z$ or demagnetization field during the switching. Our simulation confirms that large demagnetization is detrimental to the ultra-fast magnetization reversal of magnetic ultra-thin films.

Magnetic properties of micro-patterned array of anti-dots in Co/Ni bilayer

  • Deshpande, N.G.;Seo, M.S.;Zheng, H.Y.;Lee, S.J.;Rhee, J.Y.;Kim, K.W.;Lee, Y.P.
    • Proceedings of the Korean Vacuum Society Conference
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    • 2010.08a
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    • pp.276-276
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    • 2010
  • Large-area micropatterned array of Co/Ni bilayer anti-dots was fabricated using photolithography and wet etching process. The surface morphology as well as the surface topography was checked by scanning electron microscopy and atomic force microscopy, whereas the magnetic properties were studied by magneto-optical Kerr effect (MOKE) and magnetic force microscopy (MFM). Systematic studies of the magnetic-reversal mechanism, the in-plane anisotropy and the switching field properties were carried out. To get a comprehensive knowledge about the domain configuration, we also employed OOMMF simulations. It was found from the MOKE measurements that a combined effect of configurational and the magneto-crystalline anisotropy simultaneously works in such micropatterned bilayer structures. In addition, the inclusion of holes in the uniform magnetic film drastically affected the switching field. The MFM images show well-defined domain structures which are periodic in nature. The micromagnetic simulations indicate that the magnetization reversal of such a structure proceeds by formation and annihilation of domain walls, which were equally manifested by the field-dependent MFM images. The observed changes in the magnetic properties are strongly related to both the patterning that hinders the domain-wall motion and to the magneto-anisotropic bilayered structure.

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