New and emerging use cases, such as the interconnection of geographically distributed data centers(DCs), are drawing attention to the requirement for dynamic end-to-end service provisioning, spanning multiple and hete...New and emerging use cases, such as the interconnection of geographically distributed data centers(DCs), are drawing attention to the requirement for dynamic end-to-end service provisioning, spanning multiple and heterogeneous optical network domains. This heterogeneity is, not only due to the diverse data transmission and switching technologies, but also due to the different options of control plane techniques. In light of this, the problem of heterogeneous control plane interworking needs to be solved, and in particular, the solution must address the specific issues of multi-domain networks, such as limited domain topology visibility, given the scalability and confidentiality constraints. In this article, some of the recent activities regarding the Software-Defined Networking(SDN) orchestration are reviewed to address such a multi-domain control plane interworking problem. Specifically, three different models, including the single SDN controller model, multiple SDN controllers in mesh, and multiple SDN controllers in a hierarchical setting, are presented for the DC interconnection network with multiple SDN/Open Flow domains or multiple Open Flow/Generalized Multi-Protocol Label Switching( GMPLS) heterogeneous domains. I n addition, two concrete implementations of the orchestration architectures are detailed, showing the overall feasibility and procedures of SDN orchestration for the end-to-endservice provisioning in multi-domain data center optical networks.展开更多
In this work, we consider device-to-device (D2D) direct communication underlaying a 3GPP LTE-A network. D2D communication enables new service opportunities, provides high throughput and reliable communication while re...In this work, we consider device-to-device (D2D) direct communication underlaying a 3GPP LTE-A network. D2D communication enables new service opportunities, provides high throughput and reliable communication while reducing the base station load. For better total performance, D2D links and cellular links share the same radio resource and the management of interference becomes a crucial task. We propose a radio resource allocation for D2D links based on interference avoidance approach. For system with multiple transmit antennas, we apply beamforming technique based on signal to leakage criterion to reduce the co-channel interference. The results show that, D2D transmission with the resource allocation and beamforming technique provides significant gain compared to that of the regular cellular network.展开更多
Reusing business process models and best practices can improve the productivity, quality and agility in the early development phases of enterprise software systems. To help developers reuse the business process models...Reusing business process models and best practices can improve the productivity, quality and agility in the early development phases of enterprise software systems. To help developers reuse the business process models and best practices, we propose a methodology and an integrated environment for business process modeling driven by the metamodel. Furthermore, we propose a process-template design method to unify the granularity and separate the commonality and variability of business processes so that business process models can be reused across different enterprise software systems. The proposed methodology enables to create reuse-oriented business process templates before the business process modeling. To support the proposed methodology, we developed an integrated environment for creating, reusing and verifying the business process models. As the key techniques, we describe the methodology and its integrated environment, including a metamodel and notations. We applied the methodology and integrated environment to an actual enterprise software development project, and evaluated that the productivity of business process modeling is improved by at least 46%. As the conclusion, this paper contributes to prove the effectiveness of the meta-model driven business process modeling methodology for the reuse of business process models.展开更多
we have developed ferroelectric capacitor fabrication technique to realize low-voltage and high-density ferroelectric random access memory （FRAM）. High temperature deposited IrOxtop electrode reveals high crystallin...we have developed ferroelectric capacitor fabrication technique to realize low-voltage and high-density ferroelectric random access memory （FRAM）. High temperature deposited IrOxtop electrode reveals high crystalline quality which drastically reduces the degradation of ferroelectric film by preventing hydrogen diffusion into ferroelectric film. This improvement enables us to commercialize highly-reliable 1T 1C FRAM with memory density of 4 Mb or larger.展开更多
Two-dimensional （2D） layered materials, transition-metal dichalcogenides, and black phosphorus have attracted considerable interest from the viewpoints of fundamental physics and device applications. The establishme...Two-dimensional （2D） layered materials, transition-metal dichalcogenides, and black phosphorus have attracted considerable interest from the viewpoints of fundamental physics and device applications. The establishment of new functionalities in anisotropic layered 2D materials is a challenging but rewarding frontier, owing to the remarkable optical properties of these materials and their prospects for new devices. Herein, we report the anisotropic and thickness- dependent optical properties of a 2D layered monochalcogenide of germanium sulfide （GeS）. Three Raman-scattering peaks corresponding to the B3g,, A1g, and A2g modes with a strong polarization dependence are demonstrated in the GeS flakes, which validates polarized Raman spectroscopy as an effective method for identifying the crystal orientation of anisotropic layered GeS. Photoluminescence （PL） is observed with a peak at -1.66 eV that originates from the direct optical transition in GeS at room temperature. The polarization-dependent characteristics of the PL, which are revealed for the first time, along with the demonstration of anisotropic absorption, indicate an obvious anisotropic optical transition near the band edge of GeS, which is supported by density functional theory calculations. The significantly thickness-dependent PL is observed and discussed. This anisotropic layered GeS presents opportunities for the discovery of new physical phenomena and will find applications that exploit its anisotropic properties, such as polarization-sensitive photodetectors.展开更多
Here we summarize multi-terabit long-haul transmission experiment and distributed Raman amplification (DRA) technologies. As well, we investigate the configuration of dispersion-managed fibers for the DRA-based system...Here we summarize multi-terabit long-haul transmission experiment and distributed Raman amplification (DRA) technologies. As well, we investigate the configuration of dispersion-managed fibers for the DRA-based system from the viewpoint of the fiber non-linear effect and required pumping power.展开更多
Polarization division multiplexing (PDM) can double the spectral efficiency of an optical transmission system. By means of simulation, the 2x40Gbit/s NRZ PDM system performance under polarization mode dispersion (PMD)...Polarization division multiplexing (PDM) can double the spectral efficiency of an optical transmission system. By means of simulation, the 2x40Gbit/s NRZ PDM system performance under polarization mode dispersion (PMD) and chromatic dispersion has been investigated. To realize the best performance, the bit slots of the two channels should be synchronized.展开更多
We demonstrated 2.16-Tbit/s (43 Gbit/s x 54 ch) WDM transmission over 600 km of standard single-mode fiber with high spectral efficiency 0.53 bit/s/Hz using optimized optical mux/demux filters for 75-GHz channel spaci...We demonstrated 2.16-Tbit/s (43 Gbit/s x 54 ch) WDM transmission over 600 km of standard single-mode fiber with high spectral efficiency 0.53 bit/s/Hz using optimized optical mux/demux filters for 75-GHz channel spacing in a simple NRZ modulation scheme.展开更多
We have demonstrated that the AGC signals generated in a master EDFA can be used to drive a slave EDFA, thus to make the slave EDFA work in AGC mode without its own AGC control electronics. This idea can be used to re...We have demonstrated that the AGC signals generated in a master EDFA can be used to drive a slave EDFA, thus to make the slave EDFA work in AGC mode without its own AGC control electronics. This idea can be used to reduce the amplifier costs in a WDM network node.展开更多
We have demonstrated a flexible twin open ring WDM network for metro applications. A pair of optical switches in the network keeps the fiber rings open to prevent signal circulation. Traffics are broadcast to every no...We have demonstrated a flexible twin open ring WDM network for metro applications. A pair of optical switches in the network keeps the fiber rings open to prevent signal circulation. Traffics are broadcast to every node and selected at the receiving side. Superior transmission and protection switching are proved.展开更多
文摘New and emerging use cases, such as the interconnection of geographically distributed data centers(DCs), are drawing attention to the requirement for dynamic end-to-end service provisioning, spanning multiple and heterogeneous optical network domains. This heterogeneity is, not only due to the diverse data transmission and switching technologies, but also due to the different options of control plane techniques. In light of this, the problem of heterogeneous control plane interworking needs to be solved, and in particular, the solution must address the specific issues of multi-domain networks, such as limited domain topology visibility, given the scalability and confidentiality constraints. In this article, some of the recent activities regarding the Software-Defined Networking(SDN) orchestration are reviewed to address such a multi-domain control plane interworking problem. Specifically, three different models, including the single SDN controller model, multiple SDN controllers in mesh, and multiple SDN controllers in a hierarchical setting, are presented for the DC interconnection network with multiple SDN/Open Flow domains or multiple Open Flow/Generalized Multi-Protocol Label Switching( GMPLS) heterogeneous domains. I n addition, two concrete implementations of the orchestration architectures are detailed, showing the overall feasibility and procedures of SDN orchestration for the end-to-endservice provisioning in multi-domain data center optical networks.
文摘In this work, we consider device-to-device (D2D) direct communication underlaying a 3GPP LTE-A network. D2D communication enables new service opportunities, provides high throughput and reliable communication while reducing the base station load. For better total performance, D2D links and cellular links share the same radio resource and the management of interference becomes a crucial task. We propose a radio resource allocation for D2D links based on interference avoidance approach. For system with multiple transmit antennas, we apply beamforming technique based on signal to leakage criterion to reduce the co-channel interference. The results show that, D2D transmission with the resource allocation and beamforming technique provides significant gain compared to that of the regular cellular network.
文摘Reusing business process models and best practices can improve the productivity, quality and agility in the early development phases of enterprise software systems. To help developers reuse the business process models and best practices, we propose a methodology and an integrated environment for business process modeling driven by the metamodel. Furthermore, we propose a process-template design method to unify the granularity and separate the commonality and variability of business processes so that business process models can be reused across different enterprise software systems. The proposed methodology enables to create reuse-oriented business process templates before the business process modeling. To support the proposed methodology, we developed an integrated environment for creating, reusing and verifying the business process models. As the key techniques, we describe the methodology and its integrated environment, including a metamodel and notations. We applied the methodology and integrated environment to an actual enterprise software development project, and evaluated that the productivity of business process modeling is improved by at least 46%. As the conclusion, this paper contributes to prove the effectiveness of the meta-model driven business process modeling methodology for the reuse of business process models.
文摘we have developed ferroelectric capacitor fabrication technique to realize low-voltage and high-density ferroelectric random access memory （FRAM）. High temperature deposited IrOxtop electrode reveals high crystalline quality which drastically reduces the degradation of ferroelectric film by preventing hydrogen diffusion into ferroelectric film. This improvement enables us to commercialize highly-reliable 1T 1C FRAM with memory density of 4 Mb or larger.
文摘Two-dimensional （2D） layered materials, transition-metal dichalcogenides, and black phosphorus have attracted considerable interest from the viewpoints of fundamental physics and device applications. The establishment of new functionalities in anisotropic layered 2D materials is a challenging but rewarding frontier, owing to the remarkable optical properties of these materials and their prospects for new devices. Herein, we report the anisotropic and thickness- dependent optical properties of a 2D layered monochalcogenide of germanium sulfide （GeS）. Three Raman-scattering peaks corresponding to the B3g,, A1g, and A2g modes with a strong polarization dependence are demonstrated in the GeS flakes, which validates polarized Raman spectroscopy as an effective method for identifying the crystal orientation of anisotropic layered GeS. Photoluminescence （PL） is observed with a peak at -1.66 eV that originates from the direct optical transition in GeS at room temperature. The polarization-dependent characteristics of the PL, which are revealed for the first time, along with the demonstration of anisotropic absorption, indicate an obvious anisotropic optical transition near the band edge of GeS, which is supported by density functional theory calculations. The significantly thickness-dependent PL is observed and discussed. This anisotropic layered GeS presents opportunities for the discovery of new physical phenomena and will find applications that exploit its anisotropic properties, such as polarization-sensitive photodetectors.
文摘Here we summarize multi-terabit long-haul transmission experiment and distributed Raman amplification (DRA) technologies. As well, we investigate the configuration of dispersion-managed fibers for the DRA-based system from the viewpoint of the fiber non-linear effect and required pumping power.
文摘Polarization division multiplexing (PDM) can double the spectral efficiency of an optical transmission system. By means of simulation, the 2x40Gbit/s NRZ PDM system performance under polarization mode dispersion (PMD) and chromatic dispersion has been investigated. To realize the best performance, the bit slots of the two channels should be synchronized.
文摘We demonstrated 2.16-Tbit/s (43 Gbit/s x 54 ch) WDM transmission over 600 km of standard single-mode fiber with high spectral efficiency 0.53 bit/s/Hz using optimized optical mux/demux filters for 75-GHz channel spacing in a simple NRZ modulation scheme.
文摘We have demonstrated that the AGC signals generated in a master EDFA can be used to drive a slave EDFA, thus to make the slave EDFA work in AGC mode without its own AGC control electronics. This idea can be used to reduce the amplifier costs in a WDM network node.
文摘We have demonstrated a flexible twin open ring WDM network for metro applications. A pair of optical switches in the network keeps the fiber rings open to prevent signal circulation. Traffics are broadcast to every node and selected at the receiving side. Superior transmission and protection switching are proved.
