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Sample records for wdm tdm local

  1. Proposta de rede de interconexão WDM com controle TDM Proposal of WDM interconnection network with TDM control

    Directory of Open Access Journals (Sweden)

    João Angelo Martini

    1999-05-01

    Full Text Available Este artigo apresenta uma proposta de rede de interconexão WDM com controle TDM e discute os princípios da tecnologia WDM. O artigo também classifica as redes de interconexão WDM e discute as arquiteturas de redes de interconexão e os protocolos de controle.This article presents a proposal for a WDM interconnection network with TDM control and discusses principles of WDM technology. It also classifies WDM interconnection networks and discusses interconnection network architectures as well as the protocols for control.

  2. Proposta de rede de interconexão WDM com controle TDM

    Directory of Open Access Journals (Sweden)

    João Angelo Martini

    1999-05-01

    Full Text Available Este artigo apresenta uma proposta de rede de interconexão WDM com controle TDM e discute os princípios da tecnologia WDM. O artigo também classifica as redes de interconexão WDM e discute as arquiteturas de redes de interconexão e os protocolos de controle.

  3. Massive WDM and TDM Soliton Transmission Systems : a ROSC Symposium

    CERN Document Server

    2002-01-01

    This book summarizes the proceedings of the invited talks presented at the “International Symposium on Massive TDM and WDM Optical Soliton Tra- mission Systems” held in Kyoto during November 9–12, 1999. The symposium is the third of the series organized by Research Group for Optical Soliton C- munications (ROSC) chaired by Akira Hasegawa. The research group, ROSC, was established in Japan in April 1995 with a support of the Japanese Ministry of Post and Telecommunications to promote collaboration and information - change among communication service companies, communication industries and academic circles in the theory and application of optical solitons. The symposium attracted enthusiastic response from worldwide researchers in the field of soliton based communications and intensive discussions were made. In the symposium held in 1997, new concept of soliton transmission based on dispersion management of optical fibers were presented. This new soliton is now called the dispersion managed soliton. The p...

  4. Energy-Saving Mechanism in WDM/TDM-PON Based on Upstream Network Traffic

    Directory of Open Access Journals (Sweden)

    Paola Garfias

    2014-08-01

    Full Text Available One of the main challenges of Passive Optical Networks (PONs is the resource (bandwidth and wavelength management. Since it has been shown that access networks consume a significant part of the overall energy of the telecom networks, the resource management schemes should also consider energy minimization strategies. To sustain the increased bandwidth demand of emerging applications in the access section of the network, it is expected that next generation optical access networks will adopt the wavelength division/time division multiplexing (WDM/TDM technique to increase PONs capacity. Compared with traditional PONs, the architecture of a WDM/TDM-PON requires more transceivers/receivers, hence they are expected to consume more energy. In this paper, we focus on the energy minimization in WDM/TDM-PONs and we propose an energy-efficient Dynamic Bandwidth and Wavelength Allocation mechanism whose objective is to turn off, whenever possible, the unnecessary upstream traffic receivers at the Optical Line Terminal (OLT. We evaluate our mechanism in different scenarios and show that the proper use of upstream channels leads to relevant energy savings. Our proposed energy-saving mechanism is able to save energy at the OLT while maintaining the introduced penalties in terms of packet delay and cycle time within an acceptable range. We might highlight the benefits of our proposal as a mechanism that maximizes the channel utilization. Detailed implementation of the proposed algorithm is presented, and simulation results are reported to quantify energy savings and effects on network performance on different network scenarios.

  5. A Hybrid TDM/WDM-PON System With FWM-Generated Source of Multiwavelength Optical Signals

    Science.gov (United States)

    Lyashuk, I.; Shchemelev, A.; Ivanov, G.

    2010-01-01

    A new approach to FTTx solutions is proposed, in the framework of which a hybrid TDM/WDM system using cascaded FWM-generated optical signals is evaluated by calculating the BER parameter and the optical power budget. Computer simulation is employed as the main method of calculations, with the results presented both in numerical and graphical forms. The results show that the use of a forward error correction allows the power margin of 4 dB to be achieved for the system to work reliably. The system can provide the total number of users up to 128 (8γx16 TDM users) with a bandwidth of multiple hundreds of Mbit/s p.u. by means of the existing passive optical networking infrastructure, with only minor improvements needed.

  6. Multi-granularity Bandwidth Allocation for Large-Scale WDM/TDM PON

    Science.gov (United States)

    Gao, Ziyue; Gan, Chaoqin; Ni, Cuiping; Shi, Qiongling

    2017-12-01

    WDM (wavelength-division multiplexing)/TDM (time-division multiplexing) PON (passive optical network) is being viewed as a promising solution for delivering multiple services and applications, such as high-definition video, video conference and data traffic. Considering the real-time transmission, QoS (quality of services) requirements and differentiated services model, a multi-granularity dynamic bandwidth allocation (DBA) in both domains of wavelengths and time for large-scale hybrid WDM/TDM PON is proposed in this paper. The proposed scheme achieves load balance by using the bandwidth prediction. Based on the bandwidth prediction, the wavelength assignment can be realized fairly and effectively to satisfy the different demands of various classes. Specially, the allocation of residual bandwidth further augments the DBA and makes full use of bandwidth resources in the network. To further improve the network performance, two schemes named extending the cycle of one free wavelength (ECoFW) and large bandwidth shrinkage (LBS) are proposed, which can prevent transmission from interruption when the user employs more than one wavelength. The simulation results show the effectiveness of the proposed scheme.

  7. Optical chaos and hybrid WDM/TDM based large capacity quasi-distributed sensing network with real-time fiber fault monitoring.

    Science.gov (United States)

    Luo, Yiyang; Xia, Li; Xu, Zhilin; Yu, Can; Sun, Qizhen; Li, Wei; Huang, Di; Liu, Deming

    2015-02-09

    An optical chaos and hybrid wavelength division multiplexing/time division multiplexing (WDM/TDM) based large capacity quasi-distributed sensing network with real-time fiber fault monitoring is proposed. Chirped fiber Bragg grating (CFBG) intensity demodulation is adopted to improve the dynamic range of the measurements. Compared with the traditional sensing interrogation methods in time, radio frequency and optical wavelength domains, the measurand sensing and the precise locating of the proposed sensing network can be simultaneously interrogated by the relative amplitude change (RAC) and the time delay of the correlation peak in the cross-correlation spectrum. Assisted with the WDM/TDM technology, hundreds of sensing units could be potentially multiplexed in the multiple sensing fiber lines. Based on the proof-of-concept experiment for axial strain measurement with three sensing fiber lines, the strain sensitivity up to 0.14% RAC/με and the precise locating of the sensors are achieved. Significantly, real-time fiber fault monitoring in the three sensing fiber lines is also implemented with a spatial resolution of 2.8 cm.

  8. Protocol and networking design issues for local access WDM networks

    NARCIS (Netherlands)

    Salvador, M.R.; Heemstra de Groot, S.M.; Niemegeers, I.G.M.M.

    This report gives an overview of some of the protocol and networking design issues that have been addressed in Flamingo, a major ongoing project which investigates the use of WDM optical technology in local access networks. Quality of service delivery and wavelength assignment are focused on in this

  9. FAULT LOCALIZATION AND ALARM CORRELATION IN OPTICAL WDM NETWORKS

    Directory of Open Access Journals (Sweden)

    G.Ramesh

    2010-06-01

    Full Text Available For several high speed networks, providing resilience against failures is an essential requirement. The main feature for designing next generation optical networks is protecting and restoring high capacity WDM networks from the failures. Quick detection, identification and restoration make networks more strong and consistent even though the failures cannot be avoided. Hence, it is necessary to develop fast, efficient and dependable fault localization or detection mechanisms. In this paper we propose a new fault localization algorithm for WDM networks which can identify the location of a failure on a failed lightpath. Our algorithm detects the failed connection and then attempts to reroute data stream through an alternate path. In addition to this, we develop an algorithm to analyze the information of the alarms generated by the components of an optical network, in the presence of a fault. It uses the alarm correlation in order to reduce the list of suspected components shown to the network operators. By our simulation results, we show that our proposed algorithms achieve less blocking probability and delay while getting higher throughput.

  10. Demonstration of a WDM/TDM hybrid PON based on a colorless frame-level reach extender

    Science.gov (United States)

    Kim, Kwang-Ok; Lee, Jie-Hyun; Lee, Sang-Soo; Jang, Youn-Seon

    2012-07-01

    We propose a hybrid passive optical network (PON) consisting of a 2.5 Gb/s reflective semiconductor optical amplifier (RSOA)-based 32 channel loopback wavelength division multiplexing-passive optical network (WDM-PON) and a colorless OEO-based frame-level reach extender (RE). This hybrid PON is designed to support a 128-way split over a 50 km transmission distance per single wavelength channel. We experimentally demonstrate the feasibility of this design through downstream and upstream packet transmission with a commercial gigabit-capable PON (GPON) product. Even if the colorless frame-level RE uses active devices at the remote node, it is still possible to increase the optical link budget through backward compatibility with existing GPON products. This design also provides wavelength conversion and an upstream burst-to-continuous mode conversion between the WDM-PON and GPON. The proposed hybrid PON can satisfy a packet loss ratio (PLR) of 10-10 at the downstream and upstream transmission including the use of forward error correction (FEC).

  11. Recent progress in WDM passive optical networks

    Science.gov (United States)

    Chung, Y. C.

    2005-11-01

    Recently, FTTH has finally emerged from the R&D stage and became a commercial reality. For example, in Japan, it has been reported that the total number of FTTH subscribers exceeded 1.5 million in 2004. In US, there have been numerous announcements of FTTH deployments by both operating companies and municipalities. It appears that this trend is rapidly spreading all over the world. At present, most of the FTTH deployments utilize TDM PON (such as GPON and EPON). However, WDM PON is beginning to attract significant attention, as Korea started a large-scale field traial this year. In fact, WDM PON has long been considered as an ultimate solution for the access networks due to its large capacity, easy management, network security, and upgradeability. In this paper, we review the current issues in WDM PON and report the relevant technical progresses achieved at KAIST. The subjects to be covered include low-cost WDM light sources (such as spectrum-sliced incoherent light sources and ASE-injected Fabry-Perot lasers), techniques for the delivery of broadcast services in WDM PON, wavelength-tracking technique for the wavelength-selective devices placed at the un-powered remote node, survivable WDM PON architectures, and fault monitoring and localization techniques.

  12. The emerging WDM EPON

    CERN Document Server

    Radivojević, Mirjana

    2017-01-01

    This book proposes dynamic wavelength and bandwidth allocation (DWBA), a hybrid of time-division multiplexing (TDM) and wavelength-division multiplexing (WDM), which offers a solution for service providers faced with multiservice networks. It discusses different models, architectures and implementations and evaluates their performance.

  13. Synchronization Algorithm for SDN-controlled All-Optical TDM Switching in a Random Length Ring Network

    DEFF Research Database (Denmark)

    Kamchevska, Valerija; Cristofori, Valentina; Da Ros, Francesco

    2016-01-01

    We propose and demonstrate an algorithm that allows for automatic synchronization of SDN-controlled all-optical TDM switching nodes connected in a ring network. We experimentally show successful WDM-SDM transmission of data bursts between all ring nodes.......We propose and demonstrate an algorithm that allows for automatic synchronization of SDN-controlled all-optical TDM switching nodes connected in a ring network. We experimentally show successful WDM-SDM transmission of data bursts between all ring nodes....

  14. Safety and efficacy of the addition of pertuzumab to T-DM1 ± taxane in patients with HER2-positive, locally advanced or metastatic breast cancer: a pooled analysis

    Directory of Open Access Journals (Sweden)

    Zhang J

    2017-11-01

    Full Text Available Jing Zhang,1,2,* Jinying Li,3 Chenjing Zhu,1 Yanlin Song,1 Fan Xia,1 Xuelei Ma1,* 1Cancer Center, West China Hospital, Collaborative Innovation Center for Biotherapy, 2Department of Neurosurgery, West China Hospital, Sichuan University, Chengdu, 3The Second Affiliated Hospital of Medical College of Qingdao University, Qingdao Central Hospital, Qingdao, People’s Republic of China *These authors contributed equally to this work Background: The aim of this review was to systematically evaluate the safety and efficacy of the addition of pertuzumab to trastuzumab emtansine (T-DM1 ± taxane in patients with human epidermal growth factor receptor 2 (HER2-positive, locally advanced breast cancer (LABC or metastatic breast cancer (MBC.Materials and methods: Several databases were searched for relevant clinical trials. The study characteristics, details of adverse events (AEs and details of treatment efficacy were extracted for analysis.Results: Six studies with 996 patients were included. Common AEs of T-DM1 + pertuzumab ± taxane included fatigue, diarrhea, nausea, epistaxis, peripheral neuropathy, increased aspartate transaminase (AST, increased alanine transaminase (ALT and thrombocytopenia. Major grade ≥3 AEs of T-DM1 + pertuzumab ± taxane included thrombocytopenia, neutropenia, fatigue, increased ALT, anemia and peripheral neuropathy. The addition of pertuzumab to T-DM1 ± taxane led to higher risks of diarrhea (especially grade ≥3 diarrhea, rash and vomiting, and decreased risks of thrombocytopenia and grade ≥3 increased AST. The relative risks of the addition of pertuzumab to T-DM1 ± taxane for objective response (1.068, 95% CI 0.945–1.207 and clinical benefit (1.038, 95% CI 0.974–1.106 were not statistically significant.Conclusion: Common AEs should be carefully monitored in HER2-positive LABC or MBC patients treated with T-DM1 + pertuzumab ± taxane. The addition of pertuzumab to T-DM1 ± taxane showed noninferior, but not superior

  15. Physical enhanced security strategy implementation in WDM PON

    Science.gov (United States)

    Bai, K. Kalyani; Ashik T., J.; Kachare, Nitin; Kumar, D. Sriram

    2017-06-01

    The enormous growth in data traffic in optical networks has raised the requirement of broadband access networks. Passive Optical Networks (PON) is capable of solving the power, bandwidth and cost problems. Time Division Multiplexed PON (TDM PON) uses a point to multipoint design which is currently being used for data transmission that initiated the requirement of maintaining customer's security in the downstream direction. These security impairments trigger the need of scrutiny for fault monitoring and eavesdropping in PONs. This paper demonstrates the Wavelength Division Multiplexed PONs (WDM-PON) using scrambling and fault monitoring to provide security which is absent in TDM passive optical networks. Results have been validated at 10 Gbps data rate using OPTISYSTEM12 simulation tool.

  16. Destiny of Destinations: Can TDM Help?

    Directory of Open Access Journals (Sweden)

    Zsuzsanna Bacsi

    2014-06-01

    Full Text Available Tourism destination management (TDM is a popular catchword of current tourism research. A research, co-financed by the European Union through the Hungary-Croatia IPA Cross-border Co-operation Programme, within the project ’Health &Rural Tourism DM Model’ (project no.: HUHR/1101/2.1.3/0006, was carried out in 2013 to analyse the specialities of TDM in health tourism destinations, the physical and human resources of such destinations, aspects of sustainability and competitiveness, the main factors of success. Primary data were collected by surveys and interviews carried out in six spa towns of Western Hungary. The main findings indicated, that the major natural natural endowment is medicinal water in the research area, tourism infrastructure and superstructure are sufficient, although the range of services, and marketing of health tourism services should be improved. Destination management organisations perform least efficiently in attracting investors. The attitudes of stakeholders of the tourism sector towards the idea of TDM differ, while in less successful destinations they are more inclined to cooperate this way, they are rather reluctant to do so in successful destinations. Assessing the traits of tourism service providers, the natural assets, the local community and the targeted tourist segments a general model of health tourism destinations is outlined by the four componenets of the well-known VICE model.

  17. WDM PONs based on colorless technology

    Science.gov (United States)

    Saliou, Fabienne; Simon, Gael; Chanclou, Philippe; Pizzinat, Anna; Lin, Huafeng; Zhou, Enyu; Xu, Zhiguang

    2015-12-01

    Wavelength Division Multiplexing (WDM) Passive Optical Network (PON) is foreseen to be part of the Next Generation Passive Optical Networks. Business and mobile fronthaul networks already express the need to develop WDM PONs in the access segment. Fixed wavelength transceivers based on Coarse WDM are already available to respond to today's market needs but Dense WDM technologies will be needed and colorless technologies are essential to provide simple and cost-effective WDM PON systems. We propose in this paper to demonstrate the capabilities of a DWDM PON system prototype based on self-seeded RSOAs and designed to transmit CPRI over 60 km of fiber at 2.5 Gbit/s.

  18. Ultrafast Hierarchical OTDM/WDM Network

    Directory of Open Access Journals (Sweden)

    Hideyuki Sotobayashi

    2003-12-01

    Full Text Available Ultrafast hierarchical OTDM/WDM network is proposed for the future core-network. We review its enabling technologies: C- and L-wavelength-band generation, OTDM-WDM mutual multiplexing format conversions, and ultrafast OTDM wavelengthband conversions.

  19. Institutional Assessment for Effective WDM Implementation ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    IDRC CRDI

    In MENA, much work has been advanced on the technical side and through public awareness. Yet,. WDM, though .... Recognition of this rural‐urban distinction is a vitally important conclusion, but not one that can be ..... In many MENA nations, it will not be possible to create a brand new agency with responsibility for. WDM.

  20. The Argo NOC: Combining TDM and GALS

    DEFF Research Database (Denmark)

    Kasapaki, Evangelia; Sparsø, Jens

    2015-01-01

    Argo is a network-on-chip developed for use in a multi-core platform designed specifically for hard real-time applications and it supports message passing across virtual end-to-end channels. Argo implements these channels using time-division-multiplexing (TDM) of the resources in the NOC following...... of the network interfaces we have managed to combine TDM and GALS and obtain a very hardware-efficient implementation of the NOC. The paper gives a brief overview of the Argo NOC and focuses on two important issues: how to safely bring the NOC out of reset and timing analysis of the network of asynchronous...

  1. Active plasmonics in WDM traffic switching applications

    National Research Council Canada - National Science Library

    Papaioannou, Sotirios; Kalavrouziotis, Dimitrios; Vyrsokinos, Konstantinos; Weeber, Jean-Claude; Hassan, Karim; Markey, Laurent; Dereux, Alain; Kumar, Ashwani; Bozhevolnyi, Sergey I; Baus, Matthias; Tekin, Tolga; Apostolopoulos, Dimitrios; Avramopoulos, Hercules; Pleros, Nikos

    2012-01-01

    .... In this article, we introduce active plasmonics into Wavelength Division Multiplexed (WDM) switching applications, using the smallest TO DLSPP-based Mach-Zehnder interferometric switch reported so far and showing its successful performance in 4×10...

  2. WDM network and multicasting protocol strategies.

    Science.gov (United States)

    Kirci, Pinar; Zaim, Abdul Halim

    2014-01-01

    Optical technology gains extensive attention and ever increasing improvement because of the huge amount of network traffic caused by the growing number of internet users and their rising demands. However, with wavelength division multiplexing (WDM), it is easier to take the advantage of optical networks and optical burst switching (OBS) and to construct WDM networks with low delay rates and better data transparency these technologies are the best choices. Furthermore, multicasting in WDM is an urgent solution for bandwidth-intensive applications. In the paper, a new multicasting protocol with OBS is proposed. The protocol depends on a leaf initiated structure. The network is composed of source, ingress switches, intermediate switches, edge switches, and client nodes. The performance of the protocol is examined with Just Enough Time (JET) and Just In Time (JIT) reservation protocols. Also, the paper involves most of the recent advances about WDM multicasting in optical networks. WDM multicasting in optical networks is given as three common subtitles: Broadcast and-select networks, wavelength-routed networks, and OBS networks. Also, in the paper, multicast routing protocols are briefly summarized and optical burst switched WDM networks are investigated with the proposed multicast schemes.

  3. WDM Network and Multicasting Protocol Strategies

    Directory of Open Access Journals (Sweden)

    Pinar Kirci

    2014-01-01

    Full Text Available Optical technology gains extensive attention and ever increasing improvement because of the huge amount of network traffic caused by the growing number of internet users and their rising demands. However, with wavelength division multiplexing (WDM, it is easier to take the advantage of optical networks and optical burst switching (OBS and to construct WDM networks with low delay rates and better data transparency these technologies are the best choices. Furthermore, multicasting in WDM is an urgent solution for bandwidth-intensive applications. In the paper, a new multicasting protocol with OBS is proposed. The protocol depends on a leaf initiated structure. The network is composed of source, ingress switches, intermediate switches, edge switches, and client nodes. The performance of the protocol is examined with Just Enough Time (JET and Just In Time (JIT reservation protocols. Also, the paper involves most of the recent advances about WDM multicasting in optical networks. WDM multicasting in optical networks is given as three common subtitles: Broadcast and-select networks, wavelength-routed networks, and OBS networks. Also, in the paper, multicast routing protocols are briefly summarized and optical burst switched WDM networks are investigated with the proposed multicast schemes.

  4. Working Paper 2: WDM, Poverty & Equity | IDRC - International ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Despite the growing practical and policy-level engagement with WDM, there has been little analytical or empirical effort devoted to its potential social implications. Establishing a better foundation for understanding the linkages between WDM and poverty is, therefore, very important. This paper shows that WDM can ...

  5. Institutional Assessment for Effective WDM Implementation ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    nkhaled

    1 Water demand management (WDM) refers to “any measure that aims to improve the efficiency of water used to achieve ..... demand-side management” and that “this bias for 'ribbon cutting' projects is maintained by political .... with lack of institutional capacity, capability and motivation- barriers that arise mainly from.

  6. Water brief-WDM & wastewater reuse

    International Development Research Centre (IDRC) Digital Library (Canada)

    aalfouns

    Water Demand Management (WDM) is a water management approach that aims to promote water- use efficient, equitable and ... freshwater, wastewater supply is cheap, reliable, and available to farmers on demand allowing them to grow crops they ... Tunisia, there exists 98 water treatment plants, around. 190 million m3 ...

  7. WDM in Courses of Communication Technologies

    Directory of Open Access Journals (Sweden)

    Miloslav Filka

    2008-01-01

    Full Text Available This conference paper shows and demonstrates how modern technologies (such as WDM – Wavelength Division Multiplex were introduced to students of Optical Networks lectured at Brno University of Technology, Faculty of Electrical Engineering and Communication, Dept. of Telecommunications.

  8. The Wavelength Conversion in WDM Networks

    Directory of Open Access Journals (Sweden)

    Miroslav Bahleda

    2004-01-01

    Full Text Available In this article we deal with a problem of wavelength conversion in WDM networks and with the wavelength conversion impact on throughput of network. The throughput of networks is determined in terms of blocking probability. The optical networks can be built without wavelength conversion or with full or limited wavelength conversion. Different traffic models are designed for different types of wavelength conversions, which describe performance of wavelength conversion. I describe some results of these models.

  9. Demonstration of flexible and reconfigurable WDM multicast scheme supporting downstream emergency multicast communication for WDM optical access network

    Science.gov (United States)

    Li, Ze; Zhang, Min; Wang, Danshi; Cui, Yue

    2017-09-01

    We propose a flexible and reconfigurable wavelength-division multiplexing (WDM) multicast scheme supporting downstream emergency multicast communication for WDM optical access network (WDM-OAN) via a multicast module (MM) based on four-wave mixing (FWM) in a semiconductor optical amplifier. It serves as an emergency measure to dispose of the burst, large bandwidth, and real-time multicast service with fast service provisioning and high resource efficiency. It also plays the role of physical backup in cases of big data migration or network disaster caused by invalid lasers or modulator failures. It provides convenient and reliable multicast service and emergency protection for WDM-OAN without modifying WDM-OAN structure. The strategies of an MM setting at the optical line terminal and remote node are discussed to apply this scheme to passive optical networks and active optical networks, respectively. Utilizing the proposed scheme, we demonstrate a proof-of-concept experiment in which one-to-six/eight 10-Gbps nonreturn-to-zero-differential phase-shift keying WDM multicasts in both strategies are successfully transmitted over single-mode fiber of 20.2 km. One-to-many reconfigurable WDM multicasts dealing with higher data rate and other modulation formats of multicast service are possible through the proposed scheme. It can be applied to different WDM access technologies, e.g., time-wavelength-division multiplexing-OAN and coherent WDM-OAN, and upgraded smoothly.

  10. Hybrid Microoptical WDM Receiver for PON Communication

    Directory of Open Access Journals (Sweden)

    Vitezslav Jerabek

    2012-01-01

    Full Text Available The paper presents the design, simulation and construction results of the wavelength division multiplex (WDM optical hybrid receiver module for the passive optical network (PON. The optical WDM receiver was constructed using system of three micromodules in the new circle topology. The optical micromodule contains multimode fiber pigtail 50/125 µm, VHGT filter with collimation lens and two microwave optoelectronics receiver micromodules (OE receiver micromodules. OE receiver micromodules were designed by use small signal equivalent electrical circuit model and noise model, from which the mathematically solved the transmittance function, which was used for calculation and simulation of the optimal frequency characteristics and signal to noise ratio. For determine the limit frequency of OE receiver micromodule, the transcendent equation with transmittance function was numerically solved. OE receiver micromodule was composed of decollimation lenses and microwave optoelectronics receivers with bandwidth 2,5 GHz and alternatively in SMD technology with bandwidth 1,25 GHz, using the thin layer hybrid technology. WDM receiver use radiation 1490 nm for internet and 1550 nm for digital TV signals download information.

  11. Working Paper 2: WDM, Poverty & Equity | IDRC - International ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    2012-01-23

    Jan 23, 2012 ... Despite the growing practical and policy-level engagement with WDM, there has been little analytical or empirical effort devoted to its potential social implications. Establishing a better foundation for understanding the linkages between WDM and poverty is, therefore, very important. This paper shows that ...

  12. Working Paper 2: WDM, Poverty & Equity | CRDI - Centre de ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Despite the growing practical and policy-level engagement with WDM, there has been little analytical or empirical effort devoted to its potential social implications. Establishing a better foundation for understanding the linkages between WDM and poverty is, therefore, very important.

  13. Programme Code for Projecting of WDM Fiber Optic Sensor Systems

    Directory of Open Access Journals (Sweden)

    R. Probstner

    1993-04-01

    Full Text Available Wavelength division multiplex (WDM offers a potentially powerful technique for use within optical fibre sensor systems. The paper deals with short description of methodology and a programme code for WDM fiber optic sensor system projecting with use of CAD.

  14. A Concept of a Hybrid WDM/TDM Topology Using the Fabry-Perot Laser in the Optiwave Simulation Environment

    Directory of Open Access Journals (Sweden)

    Radek Poboril

    2011-01-01

    Full Text Available The aim of this article is to point out the possibility of solving problems related to a concept of a flexible hybrid optical access network. The entire topology design was realized using the OPTIWAVE development environment in which particular test measurements were carried out as well. Therefore, in the following chapters, we will subsequently focus on individual parts of the proposed topology and will give reasons for their functions whilst the last part of the article consists of values measured in the topology and their overall evaluation.

  15. TDM1 Regulation Determines the Number of Meiotic Divisions.

    Directory of Open Access Journals (Sweden)

    Marta Cifuentes

    2016-02-01

    Full Text Available Cell cycle control must be modified at meiosis to allow two divisions to follow a single round of DNA replication, resulting in ploidy reduction. The mechanisms that ensure meiosis termination at the end of the second and not at the end of first division are poorly understood. We show here that Arabidopsis thaliana TDM1, which has been previously shown to be essential for meiotic termination, interacts directly with the Anaphase-Promoting Complex. Further, mutations in TDM1 in a conserved putative Cyclin-Dependant Kinase (CDK phosphorylation site (T16-P17 dominantly provoked premature meiosis termination after the first division, and the production of diploid spores and gametes. The CDKA;1-CYCA1.2/TAM complex, which is required to prevent premature meiotic exit, phosphorylated TDM1 at T16 in vitro. Finally, while CYCA1;2/TAM was previously shown to be expressed only at meiosis I, TDM1 is present throughout meiosis. These data, together with epistasis analysis, lead us to propose that TDM1 is an APC/C component whose function is to ensure meiosis termination at the end of meiosis II, and whose activity is inhibited at meiosis I by CDKA;1-TAM-mediated phosphorylation to prevent premature meiotic exit. This provides a molecular mechanism for the differential decision of performing an additional round of division, or not, at the end of meiosis I and II, respectively.

  16. Wavelength-agnostic WDM-PON System

    DEFF Research Database (Denmark)

    Wagner, Christoph; Eiselt, Michael; Zou, S.

    2016-01-01

    Next-generation WDM-PON solutions for metro and access systems will take advantage of remotely controlled wavelength-tunable ONUs to keep system costs as low as possible. For such a purpose, each ONU signal can be labeled by a pilot tone modulated onto the optical data stream. We report...... on the standardization status of this lowcost system in the new ITU-T G.metro draft recommendation, in the context of autonomous tuning. We also discuss some low-effort implementations of the pilot-tone labels and investigate the impact of these labels on the transmission channels....

  17. A Loosely Synchronizing Asynchronous Router for TDM-Scheduled NOCs

    DEFF Research Database (Denmark)

    Kotleas, Ioannis; Humphreys, Dean; Sørensen, Rasmus Bo

    2014-01-01

    This paper presents an asynchronous router design for use in time-division-multiplexed (TDM) networks-on-chip. Unlike existing synchronous, mesochronous and asynchronous router designs with similar functionality, the router is able to silently skip over cycles/TDM-slots where no traffic...... is scheduled and hence avoid all switching activity in the idle links and router ports. In this way switching activity is reduced to the minimum possible amount. The fact that this relaxed synchronization is sufficient to implement TDM scheduling represents a contribution at the conceptual level. The idea can...... only be implemented using asynchronous circuit techniques. To this end, the paper explores the use of “click-element” templates. Click-element templates use only flipflops and conventional gates, and this greatly simplifies the design process when using conventional EDA tools and standard cell...

  18. Characterisation of random DFB Raman laser amplifier for WDM transmission

    National Research Council Canada - National Science Library

    Rosa, Paweł; Rizzelli, Giuseppe; Tan, Mingming; Harper, Paul; Ania-Castañόn, Juan Diego

    2015-01-01

    We perform a full numerical characterisation of half-open cavity random DFB Raman fibre laser amplifier schemes for WDM transmission in terms of signal power variation, noise and nonlinear impairments...

  19. Gaussian Process Regression for WDM System Performance Prediction

    DEFF Research Database (Denmark)

    Wass, Jesper; Thrane, Jakob; Piels, Molly

    2017-01-01

    Gaussian process regression is numerically and experimentally investigated to predict the bit error rate of a 24 x 28 CiBd QPSK WDM system. The proposed method produces accurate predictions from multi-dimensional and sparse measurement data....

  20. Export policies for multi-domain WDM networks

    DEFF Research Database (Denmark)

    Manolova, Anna Vasileva; Ruepp, Sarah Renée

    2010-01-01

    We analyze the performance of six export policies for a multi-domain routing protocol in WDM networks. We show that providing many AS-disjoint paths for survivability and load-balancing does not necessarily guarantee the lowest connection blocking......We analyze the performance of six export policies for a multi-domain routing protocol in WDM networks. We show that providing many AS-disjoint paths for survivability and load-balancing does not necessarily guarantee the lowest connection blocking...

  1. WDM-PON Architecture for FTTx Networks

    Science.gov (United States)

    Iannone, E.; Franco, P.; Santoni, S.

    Broadband services for residential users in European countries have until now largely relied on xDSL technologies, while FTTx technologies have been mainly exploited in Asia and North America. The increasing bandwidth demand and the growing penetration of new services are pushing the deployment of optical access networks, and major European operators are now announcing FTTx projects. While FTTH is recognized as the target solution to bring broadband services to residential users, the identification of an FTTx evolutionary path able to seamlessly migrate to FTTH is key to enabling a massive deployment, easing the huge investments needed. WDM-PON architecture is an interesting solution that is able to accommodate the strategic need of building a new fiber-based access infrastructure with the possibility of adapting investments to actual demands and evolving to FTTH without requiring further interventions on fiber infrastructures.

  2. Ultimate DWDM format in fiber-true bit-parallel solitons on WDM beams

    Science.gov (United States)

    Yeh, C.; Bergman, L. A.

    2000-01-01

    Whether true solitons can exist on WDM beams (and in what form) is a question that is generally unknown. This paper will discuss an answer to this question and a demonstration of the bit-parallel WDM transmission.

  3. Modelling and evaluation of optical WDM transport networks

    Science.gov (United States)

    Wauters, Nico

    1997-10-01

    In this PhD thesis optical WDM transport networks are investigated that use novel optical components to transmit simultaneously multiple datasignals using WDM and which route in their nodes incoming datasignals to one of the outlet fibers without converting these signals to the electrical domain. The goal of the thesis is twofold. On the one hand developing new models that lead to a classification of components, nodes, network architectures and network management techniques such as monitoring and signalling. On the other hand to investigate to which extent wavelength convertors are required for an optimal use of the available wavelength channels. At the same time the tuneability of the WDM terminal multiplexers is questioned. Part 1 gives a general introduction to optical transmission and network techniques by an extensive study of the literature and a limited market survey. In part 2 we propose a number of new models to represent WDM networks and their main building blocks. This leads to a black box model and a classification of all the OXC architectures. Secondly we extend the G.803 layer structure with new layers allowing the representation of hybrid WDM and SDH networks. Finally the model is used to classify different signalling and monitoring options that can be followed. In part 3 we investigate the requirement of wavelength convertors and the tuneability of the WDM terminal multiplexers. The main conclusion of this part is that wavelength translation is not a conditio sine qua non to achieve low blocking probabilities. This contrasts to the much larger difference that appeared between WPa and WPb and which allowed us to conclude that tuneability of the WDM terminal multiplexers is thoroughly required. We do not want to disregard other consequences of not using wavelength convertors in the network as e.g., simplified wavelength management in networks with wavelength convertors and the regeneration capabilities of new all- optical wavelength conversion devices.

  4. An extended differentiated optical services model for WDM optical networks

    Science.gov (United States)

    Ouyang, Yong; Zeng, Qingji; Wei, Wei

    2004-04-01

    The need to provide QoS-guaranteed services in the WDM optical networks is becoming increasingly important because of a variety of candidate client networks (e.g., IP, ATM, SONET/SDH) and the requirement for QoS-delivery within the transport layers. This article addresses the QoS problem and presents a framework of QoS provisioning in the WDM optical network. We first characterize the QoS problem in the WDM optical network by comparing with that in the traditional networks. Then we propose a QoS service model in the optical domain called extended differentiated optical services (E-DoS) model based on a set of optical parameters that captures the quality, the reliability and the priority of an optical connection. Each component of the E-DoS model has been analyzed in detail in this article.

  5. Impact of transmission parameters on Nyquist WDM system

    Science.gov (United States)

    Kowalczyk, Agnieszka; Perlicki, Krzysztof

    2015-09-01

    In this paper the analysis of the transmission quality in Nyquist WDM transport system is presented. Results are presented of a system simulation carried out for different modulation format, symbol rates, channel spacing and filter characteristics of the transmitter and receiver. This paper also contains the comparison between results obtained for the N-WDM (Nyquist Wavelength Division Multiplexing) and DWDM (Dense Wavelength Division Multiplexing) system. Two quality indicators are taken into consideration: interchannel crosstalk and symbol error rate for both different system configurations.

  6. Investigation of SPM in WDM System with EDFA

    Directory of Open Access Journals (Sweden)

    Tomáš Ivaniga

    2016-12-01

    Full Text Available The article describes a nonlinear phenomenon SPM (Self Phase Modulation, which occurs in the all-optical communications systems. In the 21st century, the WDM (Wavelength Division Multiplex system cannot be created without the software that simulates the system under real conditions. The most important WDM components include the EDFA (Erbium Doped Fiber Amplifier, in which amplification occurs at all wavelengths. The 10 Gbps optical line DWDM (Dense Wavelength Division Multiplex system is created according to the ITU-T.G.694.1, in which the SPM phenomenon is observed.

  7. 100G WDM Transmission over 100 meter Multimode Fiber

    DEFF Research Database (Denmark)

    Cimoli, Bruno; Estaran Tolosa, Jose Manuel; Rodes Lopez, Guillermo Arturo

    We present a comparative performance analysis for wavelength-grid selection in WDM shortrange multimode-fibers. We study 100Gbps links over OM2, OM3 and OM4 fibers and show it is feasible to reach over 100 m transmission distances.......We present a comparative performance analysis for wavelength-grid selection in WDM shortrange multimode-fibers. We study 100Gbps links over OM2, OM3 and OM4 fibers and show it is feasible to reach over 100 m transmission distances....

  8. The AGNP-TDM expert group consensus guidelines: therapeutic drug monitoring in psychiatry.

    Science.gov (United States)

    Baumann, P; Hiemke, C; Ulrich, S; Eckermann, G; Gaertner, I; Gerlach, M; Kuss, H-J; Laux, G; Müller-Oerlinghausen, B; Rao, M L; Riederer, P; Zernig, G

    2004-11-01

    Therapeutic Drug Monitoring (TDM) is a valid tool to optimise pharmacotherapy. It enables the clinician to adjust the dosage of drugs according to the characteristics of the individual patient. In psychiatry, TDM is an established procedure for lithium, some antidepressants and antipsychotics. In spite of its obvious advantages, however, the use of TDM in everyday clinical practice is far from optimal. The interdisciplinary TDM group of the Arbeitsgemeinschaft fur Neuropsychopharmakologie und Pharmakopsychiatrie (AGNP) has therefore worked out consensus guidelines to assist psychiatrists and laboratories involved in psychotropic drug analysis to optimise the use of TDM of psychotropic drugs. Five research-based levels of recommendation were defined with regard to routine monitoring of plasma concentrations for dose titration of 65 psychoactive drugs: (1) strongly recommended, (2) recommended, (3) useful, (4) probably useful and (5) not recommended. A second approach defined indications to use TDM, e. g. control of compliance, lack of clinical response or adverse effects at recommended doses, drug interactions, pharmacovigilance programs, presence of a genetic particularity concerning the drug metabolism, children, adolescents and elderly patients. Indications for TDM are relevant for all drugs either with or without validated therapeutic ranges. When studies on therapeutic ranges are lacking, target ranges should be plasma concentrations that are normally observed at therapeutic doses of the drug. Therapeutic ranges of plasma concentrations that are considered to be optimal for treatment are proposed for those drugs, for which the evaluation of the literature demonstrated strong evidence. Moreover, situations are defined when pharmacogenetic (phenotyping or genotyping) tests are informative in addition to TDM. Finally, practical instructions are given how to use TDM. They consider preparation of TDM, analytical procedures, reporting and interpretation of results

  9. Grant management procedure for energy saving TDM-PONs

    Science.gov (United States)

    Alaelddin, Fuad Yousif Mohammed; Newaz, S. H. Shah; AL-Hazemi, Fawaz; Choi, Jun Kyun

    2018-01-01

    In order to minimize energy consumption in Time Division Multiplexing-Passive Optical Network (TDM-PON), IEEE and ITU-T have mandated sleep mode mechanism for Optical Network Units (ONUs) in the latest TDM-PON standards (e.g. IEEE P1904.1 SIEPON, ITU-T G.sup45). The sleep mode mechanism is a promising mean for maximizing energy saving in an ONU. An ONU in sleep mode flips between sleep and active state depending on the presence or absent of upstream and downstream frames. To ensure Quality of Service (QoS) of upstream frames, the recent TDM-PON standards introduced an early wake-up mechanism, in which an ONU is forced to leave the sleep state on upstream frame arrival. When the Optical Line Terminal (OLT) of a TDM-PON allows early wake-up of its connected ONUs, it allocates gratuitous grants for the sleeping ONUs along with allocating upstream grants for the ONUs in active state. Note that, the gratuitous grants control message sent periodically by the OLT on Inter-Gratuitous grant Interval (IGI) time. After leaving sleep state due to the arrival of upstream frame, the ONU uses its allocated gratuitous grant to send a control message mentioning the amount of upstream bandwidth (upstream grant) required in order to forward the remaining frames in its buffer. However, the existing early wake-up process of ONU can lead to increase the energy consumption of an ONU. It is because of the ONU wakes-up immediately from the sleep state on arrival of the upstream frame, but even so, it needs to wait for forwarding the frame until its allocated gratuitous grant period, resulting in spending energy unnecessarily. In addition, current energy saving solution for TDM-PONs do not provide a clear solution on how to manage different types of grants (e.g. listening grant, upstream transmission grant) within a Dynamic Bandwidth Allocation (DBA) polling cycle. To address this problem, we propose a state-of-art Grant Management Procedure (GMP) in order to maximize energy saving in a TDM

  10. Advanced integrated WDM system for POF communication

    Science.gov (United States)

    Haupt, M.; Fischer, U. H. P.

    2009-01-01

    Polymer Optical Fibres (POFs) show clear advantages compared to copper and glass fibres. In essence, POFs are inexpensive, space-saving and not susceptible to electromagnetic interference. Thus, the usage of POFs have become a reasonable alternative in short distance data communication. Today, POFs are applied in a wide number of applications due to these specific advantages. These applications include automotive communication systems and in-house-networks. State-of-the-art is to transmit data with only one channel over POF, this limits the bandwidth. To solve this problem, an integrated MUX/DEMUX-element for WDM over POF is designed and developed to use multiple channels. This integration leads to low costs, therefore this component is suitable for mass market applications. The fundamental idea is to separate the chromatic parts of the light in its monochromatic components by means of a grating based on an aspheric mirror. Due to the high NA of the POF the setup has to be designed in a 3D-approach. Therefore this setup cannot be compared with the planar solutions available on market, they would result high losses in the 3rd dimension. To achieve a fast and optimized design an optical simulation program is used. Particular attention has to be paid to the design of the POF as a light source in the simulation program and the optimisation of the grating. The following realization of the demultiplexer is planed to be done with injection molding. This technology offers easy and very economical processing. These advantages make this technology first choice for optical components in the low-cost array.

  11. A TDM link with channel coding and digital voice.

    Science.gov (United States)

    Jones, M. W.; Tu, K.; Harton, P. L.

    1972-01-01

    The features of a TDM (time-division multiplexed) link model are described. A PCM telemetry sequence was coded for error correction and multiplexed with a digitized voice channel. An all-digital implementation of a variable-slope delta modulation algorithm was used to digitize the voice channel. The results of extensive testing are reported. The measured coding gain and the system performance over a Gaussian channel are compared with theoretical predictions and computer simulations. Word intelligibility scores are reported as a measure of voice channel performance.

  12. Oral recombinant human or mouse lactoferrin reduces Mycobacterium tuberculosis TDM induced granulomatous lung pathology.

    Science.gov (United States)

    Hwang, Shen-An; Kruzel, Marian L; Actor, Jeffrey K

    2017-02-01

    Trehalose 6'6-dimycolate (TDM) is the most abundant glycolipid on the cell wall of Mycobacterium tuberculosis (MTB). TDM is capable of inducing granulomatous pathology in mouse models that resembles those induced by MTB infection. Using the acute TDM model, this work investigates the effect of recombinant human and mouse lactoferrin to reduce granulomatous pathology. C57BL/6 mice were injected intravenously with TDM at a dose of 25 μg·mouse -1 . At day 4 and 6, recombinant human or mouse lactoferrin (1 mg·(100 μL) -1 ·mouse -1 ) were delivered by gavage. At day 7 after TDM injection, mice were evaluated for lung pathology, cytokine production, and leukocyte populations. Mice given human or mouse lactoferrin had reduced production of IL-12p40 in their lungs. Mouse lactoferrin increased IL-6 and KC (CXCL1) in lung tissue. Increased numbers of macrophages were observed in TDM-injected mice given human or mouse lactoferrin. Granulomatous pathology, composed of mainly migrated leukocytes, was visually reduced in mice that received human or mouse lactoferrin. Quantitation of granulomatous pathology demonstrated a significant decrease in mice given human or mouse lactoferrin compared with TDM control mice. This report is the first to directly compare the immune modulatory effects of both heterologous recombinant human and homologous mouse lactoferrin on the development of TDM-induced granulomas.

  13. Transportation Demand Management Planning At Multi-Tenant Buildings, An Example Of Tdm Planning During Project

    Science.gov (United States)

    1988-09-01

    THIS GUIDE FOR DEVELOPERS, BUILDING OWNERS AND BUILDING MANAGERS IS ONE IN A SERIES OF SAMPLES OF TDM PLANS THAT ILLUSTRATE THE DESIGN AND PROPOSED APPLICATION OF TDM STRATEGIES. THIS SAMPLE PLAN WAS PREPARED FOR A FICTITIOUS BUILDING MANAGER NEAR DO...

  14. Characterisation of random DFB Raman laser amplifier for WDM transmission

    OpenAIRE

    Rosa, Paweł; Rizzelli, Giuseppe; Tan, Mingming; Harper, Paul; Ania-Castañón, Juan Diego

    2015-01-01

    We perform a full numerical characterisation of half-open cavity random DFB Raman fibre laser amplifier schemes for WDM transmission in terms of signal power variation, noise and nonlinear impairments, showcasing the excellent potential of this scheme to provide amplification for DWDM transmission with very low gain variation. © 2015 Optical Society of America

  15. Mode-Locked Laser Arrays for WDM Applications

    Science.gov (United States)

    Forouhar, S.

    1997-01-01

    Colliding pulse mode-locked laser arrays are being developed at 20 GHz for WDM applications. Arrays with 5 wavelengths in the EDFA gain bandwidth have already been demonstrated, with the final goal being a packaged, 10 wavelength mode-locked laser array.

  16. Temporal Probabilistic Constellation Shaping for WDM Optical Communication Systems

    DEFF Research Database (Denmark)

    Yankov, Metodi Plamenov; Forchhammer, Søren

    2016-01-01

    Finite state machine sources transmitting QPSK are studied as input to WDM optical fiber systems with ideal distributed Raman amplification. The probabilities of successive constellation symbols are shaped for nonlinear transmission and gains of around 500km (5-10%) are demonstrated...

  17. POLICY BRIEF 1 - WDM Criteria | IDRC - International Development ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    2012-01-18

    Jan 18, 2012 ... ... of technology, it is about managing and moderating our demands for good quality fresh water. It is less a matter of piping and pumps and more a tool for changing the ways we use water and the rates at which we use it. In practice, WDM comes down to three key goals: efficiency, equity and sustainability.

  18. Mitigation of inter-channel nonlinear interference in WDM systems

    CERN Document Server

    Dar, Ronen; Feder, Meir; Mecozzi, Antonio; Shtaif, Mark

    2014-01-01

    We demonstrate mitigation of inter-channel nonlinear interference noise (NLIN) in WDM systems for several amplification schemes. Using a practical decision directed recursive least-squares algorithm, we take advantage of the temporal correlations of NLIN to achieve a notable improvement in system performance.

  19. Characterisation of random DFB Raman laser amplifier for WDM transmission.

    Science.gov (United States)

    Rosa, Paweł; Rizzelli, Giuseppe; Tan, Mingming; Harper, Paul; Ania-Castañόn, Juan Diego

    2015-11-02

    We perform a full numerical characterisation of half-open cavity random DFB Raman fibre laser amplifier schemes for WDM transmission in terms of signal power variation, noise and nonlinear impairments, showcasing the excellent potential of this scheme to provide amplification for DWDM transmission with very low gain variation.

  20. POLICY BRIEF 1 - WDM Criteria | CRDI - Centre de recherches pour ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    18 janv. 2012 ... Water demand management ― WDM ― can be hard to define. More an issue of policy than of technology, it is about managing and moderating our demands for good quality fresh water. It is less a matter of piping and pumps and more a tool for changing the ways we use water and the rates at which we ...

  1. Flexible Transport Network Expansion via Open WDM Interfaces

    DEFF Research Database (Denmark)

    Fagertun, Anna Manolova; Skjoldstrup, Bjarke

    2013-01-01

    This paper presents a successful test-bed implementation of a multi-vendor transport network interconnection via open WDM interfaces. The concept of applying Alien Wavelengths (AWs) for network expansion was successfully illustrated via deployment of multi-domain/multi-vendor end-to-end OTN...

  2. Network Architecture of a Packet-switched WDM

    NARCIS (Netherlands)

    Dey, D.; Koonen, A.M.J.; Salvador, M.R.

    2000-01-01

    We propose a packet-switched WDM slotted ring network with destination release. The total bandwidth of each channel is divided into a fixed number of equal-sized slots. The nodes are equipped with fixed transmitters and tunable receivers. Control information, which is transmitted on a specific

  3. The AGNP-TDM Expert Group Consensus Guidelines: focus on therapeutic monitoring of antidepressants.

    Science.gov (United States)

    Baumann, Pierre; Ulrich, Sven; Eckermann, Gabriel; Gerlach, Manfred; Kuss, Hans-Joachim; Laux, Gerd; Müller-Oerlinghausen, Bruno; Rao, Marie Luise; Riederer, Peter; Zernig, Gerald; Hiemke, Christoph

    2005-01-01

    Therapeutic drug monitoring (TDM) of psychotropic drugs such as antidepressants has been widely introduced for optimization of pharmacotherapy in psychiatric patients. The interdisciplinary TDM group of the Arbeitsgemeinschaft für Neuropsychopharmakologie und Pharmakopsychiatrie (AGNP) has worked out consensus guidelines with the aim of providing psychiatrists and TDM laboratories with a tool to optimize the use of TDM. Five research-based levels of recommendation were defined with regard to routine monitoring of drug plasma concentrations: (i) strongly recommended; (ii) recommended; (iii) useful; (iv) probably useful; and (v) not recommended. In addition, a list of indications that justify the use of TDM is presented, eg, control of compliance, lack of clinical response or adverse effects at recommended doses, drug interactions, pharmacovigilance programs, presence of a genetic particularity concerning drug metabolism, and children, adolescents, and elderly patients. For some drugs, studies on therapeutic ranges are lacking, but target ranges for clinically relevant plasma concentrations are presented for most drugs, based on pharmacokinetic studies reported in the literature. For many antidepressants, a thorough analysis of the literature on studies dealing with the plasma concentration-clinical effectiveness relationship allowed inclusion of therapeutic ranges of plasma concentrations. In addition, recommendations are made with regard to the combination of pharmacogenetic (phenotyping or genotyping) tests with TDM. Finally, practical instructions are given for the laboratory practitioners and the treating physicians how to use TDM: preparation of TDM, drug analysis, reporting and interpretation of results, and adequate use of information for patient treatment TDM is a complex process that needs optimal interdisciplinary coordination of a procedure implicating patients, treating physicians, clinical pharmacologists, and clinical laboratory specialists. These

  4. Building WDM wide area resilient transport network from 4-node semi-mesh and mesh sub-networks

    DEFF Research Database (Denmark)

    Limal, Emmanuel; Mikkelsen, Benny; Stubkjær, Kristian

    1997-01-01

    This paper deals with optical transport network design using wavelength division multiplexing (WDM) facilities. It proposes a method for building networks from sub-network combinations. Two types of 4-node sub-networks and their properties are presented. For each sub-network, any fiber break can...... be recovered using re-routing paths. A European network set-up illustrates the method capabilities. The network has 19 nodes connected through 39 links distributed within 9 semi-mesh sub-networks. Comparison is made between local and non-local re-routing and between channel capacities of 2.5 and 10 Gb...

  5. 2R regeneration based on Dispersion-Imbalanced Loop Mirror and its Applications in WDM systems

    DEFF Research Database (Denmark)

    Chi, Nan; Carlsson, Birger; Jeppesen, Palle

    2002-01-01

    2R regeneration based on dispersion-imbalanced loop mirror is investigated including the characteristics of transfer function, output extinction ratio, initial chirp, predispersion, and WDM signals transfer functions. Theoretical results show that the input peak power is a critical parameter for ...... regenerator based on a DILM consisting of a single mode fiber (SMF) and a highly nonlinear dispersion-shifted fiber (DSF) after WDM transmission over 40 km SMF of the WDM signals....

  6. Dynamic traffic grooming for port number optimization in WDM optical mesh networks

    Science.gov (United States)

    Huang, Jun; Zeng, Qingji; Liu, Jimin; Xiao, Pengcheng; Liu, Hua; Xiao, Shilin

    2004-04-01

    In this paper, the objective was optimizing the port number with dynamic traffic grooming of SDH/SONET WDM mesh networks to give useful referenced data to networks design and the cost control of networks. The performances of different path select routing algorithms were evaluated in WDM grooming networks by considering traffic of different bandwidth requests. Finally, the results were presented and compared with in distributed-controlled WDM mesh networks.

  7. Dynamic traffic grooming with multigranularity traffic in WDM optical mesh networks

    Science.gov (United States)

    Huang, Jun; Zeng, Qingji; Liu, Jimin; Xiao, Pengcheng; Liu, Hua; Xiao, Shilin

    2004-04-01

    In this paper, a traffic-grooming problem for multi-granularity traffic of SDH/SONET in WDM grooming mesh networks is investigated. We propose a path select routing algorithm to solve this problem. The performances of this traffic grooming path select routing algorithm are evaluated in WDM grooming networks. Finally, we presented and compared the simulation results of this algorithm in dynamic traffic grooming WDM mesh networks with that of other algorithms.

  8. All-optical WDM Regeneration of DPSK Signals using Optical Fourier Transformation and Phase Sensitive Amplification

    DEFF Research Database (Denmark)

    Guan, Pengyu; Røge, Kasper Meldgaard; Kjøller, Niels-Kristian

    2015-01-01

    We propose a novel all-optical WDM regeneration scheme for DPSK signals based on optical Fourier transformation and phase sensitive amplification. Phase regeneration of a WDM signal consisting of 4x10-Gbit/s phase noise degraded DPSK channels is demonstrated for the first time.......We propose a novel all-optical WDM regeneration scheme for DPSK signals based on optical Fourier transformation and phase sensitive amplification. Phase regeneration of a WDM signal consisting of 4x10-Gbit/s phase noise degraded DPSK channels is demonstrated for the first time....

  9. All-optical ultra-high-speed OFDM to Nyquist-WDM conversion

    DEFF Research Database (Denmark)

    Guan, Pengyu; Røge, Kasper Meldgaard; Mulvad, Hans Christian Hansen

    2015-01-01

    We propose an all-optical ultra-high-speed OFDM to Nyquist-WDM conversion scheme based on complete OFT. An 8-subcarrier 640 Gbit/s DPSK OFDM super-channel is converted to eight 80-Gbit/s Nyquist-WDM channels with BER <10−9 performance for all channels.......We propose an all-optical ultra-high-speed OFDM to Nyquist-WDM conversion scheme based on complete OFT. An 8-subcarrier 640 Gbit/s DPSK OFDM super-channel is converted to eight 80-Gbit/s Nyquist-WDM channels with BER

  10. Solutions for 400 Gbit/s inter data center WDM transmission

    DEFF Research Database (Denmark)

    Dochhan, Annika; Eiselt, Nicklas; Griesser, Helmut

    2016-01-01

    We review some currently discussed solutions for 400 Gbit/s inter-data center WDM transmission for up to 100 km. We focus on direct detected solutions, namely PAM4 and DMT, and present two WDM systems based on these formats.......We review some currently discussed solutions for 400 Gbit/s inter-data center WDM transmission for up to 100 km. We focus on direct detected solutions, namely PAM4 and DMT, and present two WDM systems based on these formats....

  11. The Gain of Performance of Optical WDM Networks

    Directory of Open Access Journals (Sweden)

    Miroslav Bahleda

    2008-01-01

    Full Text Available We study the blocking probability and performance of single-fiber and multifiber optical networks with wavelength division multiplexing (WDM. We extend the well-known analytical blocking probability model by Barry and Humblet to the general model, which is proposed for both single-fiber and multifiber network paths with any kind of wavelength conversion (no, limited, or full wavelength conversion and for uniform and nonuniform link loads. We investigate the effect of the link load, wavelength conversion degree, and the number of wavelengths, fibers, and hops on blocking probability. We also extend the definition of the gain of wavelength conversion by Barry and Humblet to the gain of performance, which is fully general. Thanks to this definition and implementation of our model, we compare different WDM node architectures and present interesting results.

  12. A SURVEY ON WAVELENGTH DIVISION MULTIPLEXING (WDM NETWORKS

    Directory of Open Access Journals (Sweden)

    G. Ramesh

    2010-03-01

    Full Text Available Communication networks have emerged as a source of empowerment in today’s society. At the global level, the Internet is becoming the backbone of the modern economy. The new generations in developed countries cannot even conceive of a world without broadband access to the Internet. The inability of the current Internet infrastructure to cope with the wide variety and ever growing number of users, emerging networked applications, usage patterns and business models is increasingly being recognized worldwide. The dynamic growth of Internet traffic and its bursty nature requires high transmission rate. With the advances and the progress in Wavelength Division Multiplexing (WDM technology, the amount of raw bandwidth available in fiber links has increased to high magnitude. This paper presents a survey on WDM networks from its development to the current status. Also an analysis on buffer size in optical networks for real time traffic was performed.

  13. WDM Systems and Networks Modeling, Simulation, Design and Engineering

    CERN Document Server

    Ellinas, Georgios; Roudas, Ioannis

    2012-01-01

    WDM Systems and Networks: Modeling, Simulation, Design and Engineering provides readers with the basic skills, concepts, and design techniques used to begin design and engineering of optical communication systems and networks at various layers. The latest semi-analytical system simulation techniques are applied to optical WDM systems and networks, and a review of the various current areas of optical communications is presented. Simulation is mixed with experimental verification and engineering to present the industry as well as state-of-the-art research. This contributed volume is divided into three parts, accommodating different readers interested in various types of networks and applications. The first part of the book presents modeling approaches and simulation tools mainly for the physical layer including transmission effects, devices, subsystems, and systems), whereas the second part features more engineering/design issues for various types of optical systems including ULH, access, and in-building system...

  14. WDM Phase-Modulated Millimeter-Wave Fiber Systems

    DEFF Research Database (Denmark)

    Yu, Xianbin; Prince, Kamau; Gibbon, Timothy Braidwood

    2012-01-01

    This chapter presents a computer simulation case study of two typical WDM phase-modulated millimeter-wave systems. The phase-modulated 60 GHz fiber multi-channel transmission systems employ single sideband (SSB) and double sideband subcarrier modulation (DSB-SC) schemes and present one...... of the latest research efforts in the rapidly emerging Radio-over-Fiber (RoF) application space for in-house access networks....

  15. Dispersion management of holographic grating filter for WDM applications

    Science.gov (United States)

    Han, Seunghoon; Kim, Taesu; Chung, Seunghwan; Lee, Byoungho

    2004-10-01

    We propose a model of a holographic grating (HG) filter for WDM applications and provide a method to control the chromatic dispersion of WDM demultiplexer as one of its specific applications. The general filter characteristics can be described as a correlation between the scattered mode from the HG and the out-coupling optic mode. We note that the HG phase distribution and lens aberration of out-coupling optics provide effective phase modulation for the chromatic dispersion of the filtered output. Also the amplitude distributions of the two modes perform a kind of weighting function (i.e., apodization), which controls the overall filter spectrum. This filter scheme can exploit wavelength dependent diffraction angle transition (i.e., spatial dispersion) and can be used for multi-channel demultiplexer in WDM system. In this case, lens aberrations of the out-coupling optics cause chromatic dispersion problems in each separated channel and among the channels. The problems can be managed by controlling the HG phase distribution so that the overall chromatic dispersion of the demultiplexer can be reduced and managed over the demultiplexed channels. We characterize the chromatic dispersion properties according to the third order lens aberrations and propose methods to control them by using HG phase distribution.

  16. A single comb laser source for short reach WDM interconnects

    Science.gov (United States)

    Wojcik, Gregory L.; Yin, Dongliang; Kovsh, Alexey R.; Gubenko, Alexey E.; Krestnikov, Igor L.; Mikhrin, Sergey S.; Livshits, Daniil A.; Fattal, David A.; Fiorentino, Marco; Beausoleil, Raymond G.

    2009-02-01

    High-channel-count WDM will eventually be used for short reach optical interconnects since it maximizes link bandwidth and efficiency. An impediment to adoption is the fact that each WDM wavelength currently requires its own DFB laser. The alternative is a single, multi-wavelength laser, but noise, size and/or expense make existing options impractical. In contrast, a new low-noise, diode comb laser based on InAs/GaAs quantum dots provides a practical and timely alternative, albeit in the O-band. Samples are being evaluated in short reach WDM development systems. Tests show this type of Fabry-Perot laser permits >10 Gb/s error-free modulation of 10 to over 50 separate channels, as well as potential for 1.25 Gb/s direct modulation. The paper describes comb laser requirements, noise measurements for external and direct modulation, O-band issues, transmitter photonic circuitry and components, future CMP applications, and optical couplers that may help drive down packaging costs to below a dollar.

  17. Improving the cost effectiveness of financial incentives in managing travel demand management (TDM).

    Science.gov (United States)

    2013-10-01

    Providing financial incentives to commuters to use alternative modes is a common element of managing transportation demand. Although these incentives have become common during the past two decades as elements of transportation demand management (TDM)...

  18. Synchronization in a Random Length Ring Network for SDN-Controlled Optical TDM Switching

    DEFF Research Database (Denmark)

    Kamchevska, Valerija; Cristofori, Valentina; Da Ros, Francesco

    2016-01-01

    In this paper we focus on optical time division multiplexed (TDM) switching and its main distinguishing characteristics compared with other optical subwavelength switching technologies. We review and discuss in detail the synchronization requirements that allow for proper switching operation. In ...

  19. Key lessons — Twelve factors critical to the success of WDM at the ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    2010-12-22

    Key lessons — Twelve factors critical to the success of WDM at the policy and at the operational levels. December 22, 2010. IDRC Communications. Water demand management (WDM) programs have been widely implemented across the MENA region and elsewhere, with varying degrees of success. The criteria below are ...

  20. Key lessons: Twelve factors critical to the success of WDM at the ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    ... elsewhere, with varying degrees of success. The criteria below are intended to help policymakers determine how best to develop institutions with the capacity and capability to design, implement and monitor WDM activities and to further the concept of WDM as central to efficient, equitable and sustainable water policy.​

  1. Longest Path Reroute to Optimize the Optical Multicast Routing in Sparse Splitting WDM Networks

    National Research Council Canada - National Science Library

    Liu, Huanlin; Dai, Hongyue; Zhai, Fei; Chen, Yong; Wei, Chengying

    2015-01-01

    ... of the optical fiber and WDM networks [1-6]. The classical multicast requests are realized by the way of repeating unicast in optical layer because of the constraint by network node light-splitting and leading to the problem of low wavelength resource utilization. Therefore, how to support multicast application in optical WDM networks is becoming a ...

  2. A robust optical phase modulated 60 GHz RoF WDM system

    DEFF Research Database (Denmark)

    Yu, Xianbin; Kozuch, Wojciech; Turkiewicz, Jaroslaw

    2010-01-01

    robust 4-channel WDM optical phase modulated 60GHz wireless fiber system is proposed and simulated. In this system, a Fabry-Perot (FP) frequency interleaver is designed to suppress optical carriers for 60GHz signal generation. The simulated results show that this phase modulated WDM system is not...

  3. Therapeutic drug monitoring (TDM of atazanavir in pregnancy

    Directory of Open Access Journals (Sweden)

    S Khoo

    2012-11-01

    Full Text Available Purpose of the study: Pregnant women experience physiological changes during pregnancy resulting in clinically significant alterations in antiretroviral pharmacokinetics (PK. Therefore, achieving and maintaining optimal plasma concentrations of antiretroviral drugs is essential for maternal health and minimising the risk of mother-to-child transmission of HIV. The aim of this study is to describe atazanavir/ritonavir (ATV/r PK during pregnancy. Methods: Pregnant HIV-positive women received ATV/r as part of their routine pre-natal care. Demographic and clinical data were collected, and ATV plasma concentrations [ATV] were determined in the first (T1, second (T2 and third (T3 trimester using HPLC-MS/MS (LLQ=0.05 µg/mL. Postpartum (PP sampling was performed where applicable. Antepartum (AP and PP PK parameters were compared using a one-way ANOVA. Summary of results: From January 2007, 44 women (37 black African were enrolled in the study. All received ATV/r at a standard dose of 1 tablet once daily (300/100 mg od. 24 women were receiving ART prior to pregnancy, and 20 women initiated ATV/r during pregnancy. Median (range gestation at treatment initiation in these patients was 23.5 weeks (7–35. At the time nearest to delivery 31 patients had an undetectable plasma viral load (pVL, 6 patients had detectable pVL and 2 were unavailable. [ATV] were determined in 11/44 (T1; 25/44 (T2; 35/44 (T3 and 28/44 (PP patients. Time of TDM sampling, gestation time and [ATV] (geometric mean; 95% CI are given in the Table. 6 patients were either below or approaching the ATV MEC (0.15 µg/mL during pregnancy; of these, 4/6 achieved undetectable pVL at the time of delivery (1=pVL of 291 copies/mL; 1 unavailable. [ATV] were significantly lower at T2/T3 relative to T1/PP. Equally, in a paired analysis of 28 patients (T2/T3 vs. PP, [ATV] were significantly reduced at T2/T3 (P=0.003. Conclusions: This study represents one of the larger cohorts of women undergoing TDM

  4. Experimental demonstration of wavelength domain rogue-free ONU based on wavelength-pairing for TDM/WDM optical access networks.

    Science.gov (United States)

    Lee, Jie Hyun; Park, Heuk; Kang, Sae-Kyoung; Lee, Joon Ki; Chung, Hwan Seok

    2015-11-30

    In this study, we propose and experimentally demonstrate a wavelength domain rogue-free ONU based on wavelength-pairing of downstream and upstream signals for time/wavelength division-multiplexed optical access networks. The wavelength-pairing tunable filter is aligned to the upstream wavelength channel by aligning it to one of the downstream wavelength channels. Wavelength-pairing is implemented with a compact and cyclic Si-AWG integrated with a Ge-PD. The pairing filter covered four 100 GHz-spaced wavelength channels. The feasibility of the wavelength domain rogue-free operation is investigated by emulating malfunction of the misaligned laser. The wavelength-pairing tunable filter based on the Si-AWG blocks the upstream signal in the non-assigned wavelength channel before data collision with other ONUs.

  5. Feasibility analysis of WDM links for radar applications

    Directory of Open Access Journals (Sweden)

    D. Meena

    2015-03-01

    Full Text Available Active phased array antennas enhances the performance of modern radars by using multiple low power transmit/receive modules in place of a high power transmitter in conventional radars. Fully distributed phased array radars demand the distribution of various signals in radio frequency (RF and digital domain for real time operation. This is normally achieved through complex and bulky coaxial distribution networks. In this work, we intend to tap the inherent advantages of fiber links with wavelength division multiplexed (WDM technology and a feasibility study to adapt these links for radar applications is carried out. This is done by analysing various parameters like amplitude, delay, frequency and phase variation response of various radar waveforms over WDM links. This also includes performance evaluation of non-linear frequency modulation (NLFM signals, known for better signal to noise ratio (SNR to specific side lobe levels. NLFM waveforms are further analysed using pulse compression (PC technique. Link evaluation is also carried out using a standard simulation environment and is then experimentally verified with other waveforms like RF continuous wave (CW, pulsed RF and digital signals. Synchronization signals are generated from this variable duty cycle digital signals during real time radar operation. During evaluation of digital signals, variable transient effects for different duty cycles are observed from an amplifier configuration. A suppression method is proposed to eliminate this transient effects. Further, the link delay response is investigated using different lengths of fiber spools. It can be inferred from the experimental results that WDM links are capable of handling various signals significant to radar applications.

  6. Traffic Grooming on WDM Rings Using Optical Burst Transport

    Science.gov (United States)

    Hsueh, Yu-Li; Kim, Jaedon; Su, Ching-Fong; Rabbat, Richard; Hamada, Takeo; Tian, Cechan; Kazovsky, Leonid G.

    2006-01-01

    A sublambda traffic-grooming scheme on wavelength-division-multiplexed (WDM) rings, which is called optical burst transport (OBT), is proposed. The network protocol and architecture allow increased flexibility to tailor the transport network behavior for efficient delivery of bursty data traffic. Using different network parameters, its performance is analyzed via simulation, and the implementation issues including the media-access-control (MAC) protocol, tunable-filter controller, and burst-mode receiver are addressed. Finally, the feasibility of the OBT with an experimental testbed built by the authors is demonstrated and a streaming-video application is used to present its overall functionality.

  7. Bidirectional hybrid CATV/radio-over-fiber WDM transport system.

    Science.gov (United States)

    Lu, Hai-Han; Peng, Hsiang-Chun; Tsai, Wen-Shing; Lin, Chun-Cheng; Tzeng, Shah-Jye; Lin, Yi-Zsai

    2010-02-01

    A bidirectional hybrid cable antenna television (CATV)/radio-over-fiber (ROF) wavelength-division-multiplexing (WDM) transport system using injection locking technique to suppress the rf power degradation, tunable optical bandpass filter to generate optical single-sideband format for the CATV signal or only one optical sideband format for the ROF one, and photonic crystal fiber to reduce the net dispersion is proposed and demonstrated. Impressive performances of the carrier-to-noise ratio, the composite second-order, the composite triple beat, and the bit error rate were obtained in our proposed systems.

  8. Practical Quantum Communication and Cryptography for WDM Optical Networks

    Science.gov (United States)

    Kumar, Prem

    2004-11-01

    Keeping in mind the ubiquitous standard optical fiber for long-distance transmission and the widespread availability of efficient active and passive fiber devices, we have been developing telecom-band resources for practical quantum communication and cryptography in wave-division-multiplexed (WDM) optical networks. In this talk I present our recent results on two fronts: i) telecom-band in-fiber entanglement generation, storage, and long-distance distribution and ii) quantum-noise protected high-speed data encryption through an optically-amplified WDM line. Along the first front, with our in-fiber entanglement source all four Bell states can be readily produced and we have demonstrated violation of Bell's inequalities by up to 10 standard deviations of measurement uncertainty. With such a source we have demonstrated storage of entanglement for up to 1/8 of a millisecond. Furthermore, when each photon of the entangled pair is propagated in separate 25km-long standard fibers, high visibility quantum interference is still observed, demonstrating that this system is capable of long-distance (> 50 km) entanglement distribution. Along the second front, we have implemented a new quantum cryptographic scheme, based on Yuen's KCQ protocol, in which the inherent quantum noise of coherent states of light is used to perform the cryptographic service of data encryption. In this scheme a legitimate receiver, with use of a short, shared, secret-key, executes a simple binary decision rule on every transmitted bit. An eavesdropper, on the other hand, who does not possess the secret-key, is subjected to an irreducible quantum uncertainty in each measurement, even with the use of ideal detectors. We have implemented this scheme to demonstrate quantum-noise-protected data encryption at 650 Mbps through a 200 km, in-line amplified, WDM line. The line simultaneously carried two 10 Gbps standard data channels, 100 GHz on either side of the encrypted channel, which shows that this scheme

  9. Performance analyses of hybrid WDM/OCDM optical networks

    Directory of Open Access Journals (Sweden)

    Fábio Renan Durand

    2005-02-01

    Full Text Available In this work, optical networks using the hybrid technology of wavelength division multiplexing and optical code division multiplexing (WDM/OCDM are investigated. The architecture of the network is described and it is shown the main advantages of applied optical paths with wavelengths and optical orthogonal codes (OOC to routing and switching virtual optical paths. The main results show that the use of OOC codes together with optical codes converters have a great impact on the decrease of blocking probability for establishing virtual optical paths, increasing network use.

  10. An OTDM-To-WDM Converter Using Optical Fourier Transformation

    Directory of Open Access Journals (Sweden)

    Khin Su Myat Min

    2015-08-01

    Full Text Available We demonstrate serial-to-parallel conversion of 40 Gbps optical time division multiplexed OTDM signal to 4x10 Gbps wavelength division-multiplexed WDM individual channels by using Optical Fourier Transformation OFT method. OFT is also called time lens technique and it is implemented by the combination of dispersive fiber and phase modulation. In this research electro-optic phase modulator EOM is used as time lens. As our investigations simulation results and bit error rate BER measurements are expressed.

  11. New Heuristic Algorithm for Dynamic Traffic in WDM Optical Networks

    Directory of Open Access Journals (Sweden)

    Arturo Benito Rodríguez Garcia

    2015-12-01

    Full Text Available The results and comparison of the simulation of a new heuristic algorithm called Snake One are presented. The comparison is made with three heuristic algorithms, Genetic Algorithms, Simulated Annealing, and Tabu Search, using blocking probability and network utilization as standard indicators. The simulation was made on the WDM NSFNET under dynamic traffic conditions. The results show a substantial decrease of blocking, but this causes a relative growth of network utilization. There are also load intervals at which its performance improves, decreasing the number of blocked requests.

  12. Dynamic wired-wireless architecture for wdm stacking access networks

    OpenAIRE

    Gustavo Adolfo Puerto-Leguizamón; Laura Camila Realpe-Mancipe; Carlos Arturo Suárez-Fajardo

    2014-01-01

    Este artículo presenta una arquitectura dinámica para redes de acceso convergentes fijas e inalámbricas en red óptica pasiva ( PON) basada en multiplexación en división de tiempo (TDM) bajo el pa radigma de apilamiento de longitudes de onda. Cuatro longitudes de onda para servicios fijos transportando una carga de tráfico de 10 Gb/s, una longitud de onda reconfigurable extra y una longi tud de onda común a todas las unidades de red óptica (ONU) para el transpor te de servicios inalámbricos se...

  13. SOA Based Photonic Integrated WDM Cross-Connects for Optical Metro-Access Networks

    Directory of Open Access Journals (Sweden)

    Nicola Calabretta

    2017-08-01

    Full Text Available We present a novel optical metro node architecture that exploits the Wavelength Division Multiplexing (WDM optical cross-connect nodes for interconnecting network elements, as well as computing and storage resources. The photonic WDM cross-connect node based on semiconductor optical amplifiers (SOA allows switching data signals in wavelength, space, and time for fully exploiting statistical multiplexing. The advantages of using an SOA to realize the WDM cross-connect switch in terms of transparency, switching speed, photonic integrated amplification for loss-less operation, and gain equalization are verified experimentally. The experimental assessment of a 4 × 4 photonic integrated WDM cross-connect confirmed the capability of the cross-connect chip to switch the WDM signal in space and wavelength. Experimental results show lossless operation, low cross-talk <−30 dB, and dynamically switch within few nanoseconds. Moreover, the operation of the cross-connect switch with multiple WDM channels and diverse modulation formats is also investigated and reported. Error-free operation with less than a 2 dB power penalty for a single channel, as well as WDM input operation, has been measured for multiple 10/20/40 Gb/s NRZ-OOK, 20 Gb/s PAM4, and data-rate adaptive DMT traffic. Compensation of the losses indicates that the modular architecture could scale to a larger number of ports.

  14. Influence of trehalose 6,6'-dimycolate (TDM) during mycobacterial infection of bone marrow macrophages.

    Science.gov (United States)

    Indrigo, Jessica; Hunter, Robert L; Actor, Jeffrey K

    2002-07-01

    The relative role of surface lipids in the innate macrophage response to infection with mycobacteria remains unknown. Trehalose 6,6'-dimycolate (TDM), a major component of the mycobacterial cell wall, can elicit hypersensitive as well as T-cell-independent foreign body responses. The T-cell-independent contribution of TDM to the primary macrophage response to mycobacterial infection was investigated. Bone-marrow-derived macrophages isolated from C57BL/6 mice were infected with native Mycobacterium tuberculosis (MTB) or with MTB delipidated using petroleum ether extraction methods. The removal of surface lipids caused decreased bacterial survival in macrophages, but there was no loss of bacterial growth in broth culture. Bacterial survival within macrophages was restored upon reconstitution of the bacteria with purified TDM. The cytokine and chemokine parameters of the macrophage responses were also investigated. The amounts of IL-1beta, TNF-alpha, IL-6 and MIP-1alpha produced were significantly reduced following delipidation, but were restored upon reconstitution with TDM. The amount of IL-12 produced, but not the amount of IL-10 produced, was also significantly reduced upon macrophage infection with delipidated MTB. Furthermore, nitric oxide responses were not impaired upon infection with delipidated MTB, suggesting that intracellular survival and macrophage secretion of cytokines and chemokines are differentially controlled. These studies indicate that TDM is a major component contributing to the innate macrophage responses to MTB infection.

  15. WDM up-conversion employing frequency quadrupling in optical modulator.

    Science.gov (United States)

    Shih, Po-Tsung; Lin, Chun-Ting; Jiang, Wen-Jr; Chen, Jason Jyehong; Huang, Han-Sheng; Chen, Yu-Hung; Peng, Peng-Chun; Chi, Sien

    2009-02-02

    This work presents an optical up-conversion system with frequency quadrupling for wavelength-division-multiplexing (WDM) communication systems using a dual-parallel Mach-Zehnder modulator without optical filtering. Four-channel 1.25-Gb/s wired fiber-to-the-x (FTTx) and wireless radio-over-fiber (RoF) signals are generated and transmitted simultaneously. Moreover, the decline in receiver sensitivities due to Mach-Zehnder modulator bias drifts is also investigated. Receiver power penalties of the 20-GHz up-converted WDM signals and baseband (BB) FTTx signals are less than 1 dB when bias deviation voltage is less the 20% of the half-wave voltage. After transmission over a 50-km SSMF, the receiver power penalties of both the BB and 20-GHz RF OOK signals are less than 1 dB. Notably, 60-GHz optical up-conversion can be achieved using 15-GHz radio frequency (RF) components and equipment.

  16. Optimization of spectral band utilization in gridless WDM optical network

    Science.gov (United States)

    Martins, Indayara B.; Aldaya, Ivan; Perez-Sanchez, G.; Gallion, Philippe

    2014-02-01

    In this paper, the effects of gridless spectrum allocation in Wavelength Division Multiplexed (WDM) optical networks are examined. The advanced modulation formats and multi-rate transmissions of the signals, which are key parameters in the optical system project, are taken into account. The consumed spectrum, as well as the impact of linear and nonlinear impairments on the signal transmission, are compared to WDM network adopting standard grid and gridless ITU. To analyze the influence of these physical effects, some key network design parameters are monitored and evaluated, such as the guard band size, the signal occupied bandwidth, the laser power and the quality of channels. The applied signal modulation formats were On/Off Keying (OOK), Quadrature Phase Shift keying (QPSK), and Dual Polarization State Phase Modulation (DP-QPSK), whereas the transmission rate per wavelength was varied from 10 Gb/s to 100Ghz. The guard band, signal band, and laser power were swept and the resulted Bit Error Rate (BER) was estimated from the eye-diagram. Analytical calculations and simulations are conducted in order to evaluate the impact of the gridless spectrum allocation on both the spectral consumption and the signal quality of transmission (QoT). Results reveal that a gridless transmission system reduces the spectral consumption while offering an acceptable QoT. This work was carried out with both analytical modeling and numerical calculation using the Optisystem as well as Matlab.

  17. Digital non-linear equalization for flexible capacity ultradense WDM channels for metro core networking

    DEFF Research Database (Denmark)

    Arlunno, Valeria; Zhang, Xu; Larsen, Knud J.

    2011-01-01

    An experimental demonstration of Ultradense WDM with advanced digital signal processing is presented. The scheme proposed allows the use of independent tunable DFB lasers spaced at 12.5 GHz for ultradense WDM PM-QPSK flexible capacity channels for metro core networking. To allocate extremely closed...... carriers, we demonstrate that a digital non-linear equalization allow to mitigate inter-channel interference and improve overall system performance in terms of OSNR. Evaluation of the algorithm and comparison with an ultradense WDM system with coherent carriers generated from a single laser are also...

  18. Validation of a Commercial Assay and Decision Support Tool for Routine Paclitaxel Therapeutic Drug Monitoring (TDM).

    Science.gov (United States)

    Joerger, Markus; Kraff, Stefanie; Jaehde, Ulrich; Hilger, Ralf A; Courtney, Jodi B; Cline, Daniel J; Jog, Sonali; Baburina, Irina; Miller, M Craig; Salamone, Salvatore J

    2017-12-01

    The value of therapeutic drug monitoring (TDM) for paclitaxel (PTX) was recently demonstrated in the largest TDM trial ever conducted in oncology. The trial demonstrated significant reduction in neuropathy when using TDM. Dose adjustment for PTX was based on time above a threshold concentration (Tc>0.05). Tc>0.05 must be calculated with a pharmacokinetic model and complex nonlinear mixed-effects software. The use of the software and chromatographic methods to measure PTX requires specialized expertise. User-friendly methods to quantitate PTX and calculate Tc>0.05 could simplify the introduction of TDM into routine clinical practice. The immunoassay (MyPaclitaxel) was used to quantitate PTX in samples from the clinical trial; the results were used to calculate Tc>0.05 using a stand-alone computer program with a simple, friendly graphical user interface for nonlinear mixed-effects pharmacokinetic calculations (MyCare Drug Exposure Calculator). The resulting dose recommendations from the calculated Tc>0.05 were compared with those using liquid chromatography-ultraviolet detection and NONMEM to examine the efficacy of the simpler tools for TDM. There was a good agreement between the immunoassay and liquid chromatography-ultraviolet detection: Passing-Bablok regression slope was 1.045 and intercept was -6.00, R was 0.9757, and mean bias was -1.77 ng/mL (-2.07 nmol/L). Dosing recommendations were identical for 70% of the cycles and within 10% for 89% of the samples. All Tc>0.05 values were at the same or adjacent medical decision points. MyPaclitaxel assay and MyCare Drug Exposure Calculator are convenient, user-friendly tools that may be suitable for routine TDM of PTX in clinical care.

  19. SDN-enabled dynamic WDM networks to address routing information inaccuracy

    CSIR Research Space (South Africa)

    Ravhuanzwo, Lusani

    2016-11-01

    Full Text Available International Conference on Advances in Computing, Communication, & Engineering (ICACCE-2016), Coastlands Umhlanga Hotel & Resorts, Durban, 28-29 November 2016 SDN-enabled dynamic WDM networks to address routing information inaccuracy L. Ravhuanzwo, A...

  20. Constellation Shaping for WDM systems using 256QAM/1024QAM with Probabilistic Optimization

    DEFF Research Database (Denmark)

    Yankov, Metodi Plamenov; Da Ros, Francesco; Porto da Silva, Edson

    2016-01-01

    In this paper, probabilistic shaping is numerically and experimentallyinvestigated for increasing the transmission reach of wavelength divisionmultiplexed (WDM) optical communication system employing quadrature amplitudemodulation (QAM). An optimized probability mass function (PMF) of the QAMsymb...

  1. Energy-efficient WDM-OFDM-PON employing shared OFDM modulation modules in optical line terminal

    National Research Council Canada - National Science Library

    Hu, Xiaofeng; Zhang, Liang; Cao, Pan; Wang, Kongtao; Su, Yikai

    2012-01-01

    We propose and experimentally demonstrate a scheme to improve the energy efficiency of wavelength division multiplexing - orthogonal frequency division multiplexing - passive optical networks (WDM-OFDM-PONs). By using an N...

  2. On Finding the Multicast Protection Tree Considering SRLG in WDM Optical Networks

    National Research Council Canada - National Science Library

    Li, Yonggang; Jin, Yaohui; Li, Lemin; Li, Longjiang

    2006-01-01

    ...) in a primary light tree to share protections in WDM optical networks. In previous studies, how to share spare resources with SRLG constraints has not been studied in multicast optical networks...

  3. Polarization Insensitive One-to-Six WDM Multicasting in a Silicon Nanowire

    DEFF Research Database (Denmark)

    Pu, Minhao; Hu, Hao; Peucheret, Christophe

    2012-01-01

    We present polarization insensitive one-to-six WDM multicasting based on nondegenerate four-wave mixing in a silicon nanowire with angled-pump scheme. Bit-error rate measurements are performed and error-free operation is achieved....

  4. Remotely controllable WDM-PON technology for wireless fronthaul/backhaul application

    DEFF Research Database (Denmark)

    Eiselt, Michael H.; Wagner, Christoph; Lawin, Mirko

    2016-01-01

    Low-cost WDM-PON solutions for fronthaul and backhaul applications will include remotely controlled tail-end transceivers. We report on control aspects of these transceivers and how standardization is evolving to enable these applications.......Low-cost WDM-PON solutions for fronthaul and backhaul applications will include remotely controlled tail-end transceivers. We report on control aspects of these transceivers and how standardization is evolving to enable these applications....

  5. Real time algorithm temperature compensation in tunable laser / VCSEL based WDM-PON system

    DEFF Research Database (Denmark)

    Iglesias Olmedo, Miguel; Rodes Lopez, Roberto; Pham, Tien Thang

    2012-01-01

    We report on a real time experimental validation of a centralized algorithm for temperature compensation of tunable laser/VCSEL at ONU and OLT, respectively. Locking to a chosen WDM channel is shown for temperature changes over 40°C.......We report on a real time experimental validation of a centralized algorithm for temperature compensation of tunable laser/VCSEL at ONU and OLT, respectively. Locking to a chosen WDM channel is shown for temperature changes over 40°C....

  6. Optical fronthauling for 5G mobile: A perspective of passive metro WDM technology

    DEFF Research Database (Denmark)

    Zou, Shihuan Jim; Wagner, Christoph; Eiselt, Michael

    2017-01-01

    We discuss the necessity of passive WDM technology in the 5G fronthaul application. The proof-of-concept field trial showed that the proposed system integrated seamlessly with the current wireless equipment and had no impact on services.......We discuss the necessity of passive WDM technology in the 5G fronthaul application. The proof-of-concept field trial showed that the proposed system integrated seamlessly with the current wireless equipment and had no impact on services....

  7. Digital Non-Linear Equalization for Flexible Capacity Ultradense WDM Channels for Metro Core Networking

    DEFF Research Database (Denmark)

    Arlunno, Valeria; Zhang, Xu; Larsen, Knud J.

    2011-01-01

    We experimentally demonstrate that digital non-linear equalization allows for using independent tunable DFB lasers spaced at 12.5 GHz for ultradense WDM PM-QPSK flexible capacity channels for metro core networking.......We experimentally demonstrate that digital non-linear equalization allows for using independent tunable DFB lasers spaced at 12.5 GHz for ultradense WDM PM-QPSK flexible capacity channels for metro core networking....

  8. Novel OSNR Monitoring Technique in Dense WDM Systems using Inherently Generated CW Monitoring Channels

    DEFF Research Database (Denmark)

    Petersen, Martin Nordal

    2007-01-01

    We present a simple, yet effective OSNR monitoring technique based on an inherent effect in the optical modulator. Highly accurate OSNR monitoring is demonstrated in a 40 Gb/s dense WDM system with 50 GHz channel spacing.......We present a simple, yet effective OSNR monitoring technique based on an inherent effect in the optical modulator. Highly accurate OSNR monitoring is demonstrated in a 40 Gb/s dense WDM system with 50 GHz channel spacing....

  9. An optical WDM link simulation at 4·10 Gb/s with the COMSIS software

    Directory of Open Access Journals (Sweden)

    Benameur S.

    2009-01-01

    Full Text Available The evolution of data transmission using optical fiber media has been accelerated since the advent of technical multiplexing wavelengths (WDM, which helps to achieve bit rates of a few Tb/s transported by a single fiber. In this context, we propose in this work, to make a simulation of a system WDM, at 4·10Gb/s with the COMSIS simulator system. We will interest especially to demultiplexing. .

  10. Compact Wireless Access Nodes for WDM Bidirectional Radio-over-Fiber System Based on RSOA

    DEFF Research Database (Denmark)

    Yu, Xianbin; Gibbon, Timothy Braidwood; Tafur Monroy, Idelfonso

    2009-01-01

    We demonstrate a RSOA based WDM radio-over-fiber, bidirectional system for wireless access networks. The multi-functionalities of a RSOA, such as colorless operation, re-modulation and envelope detection, make wireless access nodes more compact.......We demonstrate a RSOA based WDM radio-over-fiber, bidirectional system for wireless access networks. The multi-functionalities of a RSOA, such as colorless operation, re-modulation and envelope detection, make wireless access nodes more compact....

  11. Comparison of WDM/Pulse-Position-Modulation (WDM/PPM) with Code/Pulse-Position-Swapping (C/PPS) Based on Wavelength/Time Codes

    Energy Technology Data Exchange (ETDEWEB)

    Mendez, A J; Hernandez, V J; Gagliardi, R M; Bennett, C V

    2009-06-19

    Pulse position modulation (PPM) signaling is favored in intensity modulated/direct detection (IM/DD) systems that have average power limitations. Combining PPM with WDM over a fiber link (WDM/PPM) enables multiple accessing and increases the link's throughput. Electronic bandwidth and synchronization advantages are further gained by mapping the time slots of PPM onto a code space, or code/pulse-position-swapping (C/PPS). The property of multiple bits per symbol typical of PPM can be combined with multiple accessing by using wavelength/time [W/T] codes in C/PPS. This paper compares the performance of WDM/PPM and C/PPS for equal wavelengths and bandwidth.

  12. An efficient mechanism for dynamic multicast traffic grooming in overlay IP/MPLS over WDM networks

    Science.gov (United States)

    Yu, Xiaojun; Xiao, Gaoxi; Cheng, Tee Hiang

    2014-08-01

    This paper proposes an efficient overlay multicast provisioning (OMP) mechanism for dynamic multicast traffic grooming in overlay IP/MPLS over WDM networks. To facilitate request provisioning, OMP jointly utilizes a data learning (DL) scheme on the IP/MPLS layer for logical link cost estimation, and a lightpath fragmentation (LPF) based method on the WDM layer for improving resource sharing in grooming process. Extensive simulations are carried out to evaluate the performance of OMP mechanism under different traffic loads, with either limited or unlimited port resources. Simulation results demonstrate that OMP significantly outperforms the existing methods. To evaluate the respective influences of the DL scheme and the LPF method on OMP performance, provisioning mechanisms only utilizing either the IP/MPLS layer DL scheme or the WDM layer LPF method are also devised. Comparison results show that both DL and LPF methods help improve OMP blocking performance, and contribution from the DL scheme is more significant when the fixed routing and first-fit wavelength assignment (RWA) strategy is adopted on the WDM layer. Effects of a few other factors, including definition of connection cost to be reported by the WDM layer to the IP/MPLS layer and WDM-layer routing method, on OMP performance are also evaluated.

  13. Bit Error Rate Performance Limitations Due to Raman Amplifier Induced Crosstalk in a WDM Transmission System

    Science.gov (United States)

    Tithi, F. H.; Majumder, S. P.

    2017-06-01

    Analysis is carried out for a single span wavelength division multiplexing (WDM) transmission system with distributed Raman amplification to find the effect of amplifier induced crosstalk on the bit error rate (BER) with different system parameters. The results are evaluated in terms of crosstalk power induced in a WDM channel due to Raman amplification, optical signal to crosstalk ratio (OSCR) and BER at any distance for different pump power and number of WDM channels. The results show that the WDM system suffers power penalty due to crosstalk which is significant at higher pump power, higher channel separation and number of WDM channel. It is noticed that at a BER 10-9, the power penalty is 8.7 dB and 10.5 dB for the length of 180 km and number of WDM channel N=32 and 64 respectively when the pump power is 20 mW and is higher at high pump power. Analytical results are validated by simulation.

  14. Study on working vacation polling system for WDM

    Science.gov (United States)

    Chen, Haiyan; Tian, Naishuo; Lu, Donghua

    2008-11-01

    In the paper, we propose a digital working vacation scheme cyclic polling system for wavelength division multiplexing (WDM). This system consists of multi-queues (terminals) whose service rate is one of the fast speed and lower speed. the fast speed mode moves cyclically from queue to queue with an exhaustive schedule. Using the decomposition approach, each queue is analyzed as a single server queue with working vacation, which works at a different rate, rather than completely stops during the vacation polling period. Using quasi birth and death chain and matrix geometric solution method, we give some performance parameters, such as the mean number of packet in the queue, throughput, busy period etc. Finally, we analyze the effect of the parameters on the mean queue length and sojourn time through numerical examples.

  15. A Simple Analytical Model for Dense WDM/OOK Systems

    Science.gov (United States)

    1994-06-01

    partial fulfillment of the requirements for the degree of MASTER OF SCIENCE IN ELECTRICAL ENGINEERING from the NAVAL POSTGRADUATE SCHOOL June, 1994...Electrical and Computer Engineering ii ABSTRACT We derive the closed form expression for the bit error probability of dense WDM systems employing an...L 2 Af2 -m.+2jRe{ 2jZ ~Z k*O m$O 47 T 1A2A.d.&I(- e 2cT)I _Ajl (e11c __e__) JISACIK ,A- ’’_ 11- A.:T + ± A1 2 1=-L bk+oba 0~ k*0 m*0 +2PRe T~ If2 -3b

  16. Multilayer recovery mechanism for IP over WDM networks

    Science.gov (United States)

    Liu, Xin; Zeng, Qingji; Wang, Yun

    2004-04-01

    In this article, we mainly focus on the integrated dynamic survivability in IP/MPLS/WDM networks under the peer-modeled architecture. We systematically investigated various integrated dynamic protection and restoration schemes combining knowledge of resource and topology information in both the IP/MPLS and WDM layers. To allocate the restorable bandwidth-guaranteed paths, we propose an integrated routing algorithm: Load-Balanced Physical Resource Minimum Hop (LBPRMH) integrated routing algorithm. In this algorithm, we present a new link cost function used in Dijkstra"s algorithm considering both physical resource and load balancing factors and employ a parameter (relevant to traffic intensity) to control the influence of two kind of information. When network load is low (traffic intensity is small), the main factor in the proposed link cost function is physical resource, which leads to high resource utilization. When network load is high, the idea of load balance becomes more important in routing, which avoids connection requests conflict and increases the efficiency of resource usage. Then extensive simulations are done to analyze and compare the dynamic survival performance of various integrated survival strategies. Resource utilization, protection efficiency, restoration efficiency are employed as metrics to evaluate the survivable performance. We demonstrate that the proposed integrated routing algorithm performs better than some existing approaches in terms of the above three metrics. The simulation results show the high resource utilization in optical layer recovery with wavelength granularity and the high restoration flexibility in IP/MPLS layer recovery with finer granularity. If the recovery action is implemented first in lower layer and then higher layer if the first action failed, the integrated protection and restoration schemes can combine the advantages of both layers and perform better than recovery schemes in either single layer.

  17. Carcinome cutané de Merkel: apport de la TEP-TDM au18FDG ...

    African Journals Online (AJOL)

    Carcinome cutané de Merkel: apport de la TEP-TDM au18FDG. Guensi Amal, Taleb Sara, Cherkaoui Salhi Ghofrane, Ait Idir Malika, Houjami Majdouline, Sahraoui Souha, Benider Abdelatif, Touil Najoua, Benmoussa Ghita, Baroudi Zineb, Chikhaoui Nabil ...

  18. Perencanaan Arrayed Waveguide Grating (AWG untuk Wavelength Division Multiplexing (WDM pada C-Band

    Directory of Open Access Journals (Sweden)

    Frezza Oktaviana Hariyadi

    2015-12-01

    Full Text Available Teknologi Arrayed Waveguide Grating (AWG, salah satu solusi membagi kanal menjadi sub kanal lebih kecil dengan mengatur selisih panjang array tetap. Dalam Makalah ini, dilakukan perencanaan desain parameter AWG beroperasi pada kanal C-Band (1530-1560 nm, untuk mendukung kebutuhan kanal WDM, baik coarse-WDM (CWDM, dense-WDM (CWDM maupun very high density-WDM (VHDWDM. Perencanaan dilakukan lewat perhitungan teoritis dan menggunakan bantuan tool berupa WDM_Phasar.Perhitungan parameter AWG secara teoritis bertujuan menghasilkan  parameter desain ideal, sementara lewat  WDM_phasar dengan menambahkan batasan ukuran devais, crosstalk dan nonuniformity, diharapkan akan diperoleh parameter desain yang lebih realistis. Adapun parameter yang diamati meliputi besarnya orde difraksi (m, panjang free propagation range (FPR, perbedaan panjang array (ΔL, jumlah array (Narray, jumlah kanal I/O (Nmax  dan free spectral range (FSR.Dengan contoh spasi kanal 100 GHz pada C-band,  dihasilkan parameter hitungan teoritis sebesar 1308,61 μm, 25,1698 μm, 43,7143, 108 buah, 27 kanal dan 21,211 nm, masing-masing untuk nilai FPR, ΔL, m, Narray, Nmax dan FSR. Sedangkan lewat bantuan WDM_Phasar dengan batasan ukuran devais (15000x9000 μm2, crosstalk (-35 dB dan nonuniformity (0,5, menghasilkan parameter AWG 1197,347 μm(FSR, 23,764 μm(ΔL, 41(m, 56 (Narray, 16(Nmax dan 11,2 nm(FSR. Semakin besar spasi kanal, jumlah bit yang bisa diangkut juga semakin banyak.

  19. Un encadrement éthique du TDM par une « charte éthique »

    OpenAIRE

    Direction de l’Information Scientifique et Technique - CNRS,

    2017-01-01

    Les résultats obtenus par TDM doivent évidemment être interprétés et analysés avec un esprit critique. Un risque serait, par exemple, d’établir des liens de causalité abusifs pour expliquer les statistiques obtenues par TDM, menant à des corrélations fallacieuses. Le TDM ouvre ainsi des nouvelles questions méthodologiques. L’intégrité de la recherche par TDM passe également par un respect de règles d’éthique. En particulier, le traitement des données personnelles doit s’effectuer dans le resp...

  20. BER analysis of SS-WDM based FSO system for Vellore weather conditions

    Science.gov (United States)

    Prabu, K.; Charanya, S.; Jain, Mehul; Guha, Debapriya

    2017-11-01

    Spectrum Slicing Wavelength Division Multiplexing (SS-WDM) has been advanced to boost the long distance communication in FSO channel which assists immense bit rate due to its high capacity and efficiency. It is a substitute to WDM systems having multiple coherent lasers with different wavelengths which is expensive. This paper is subjected to investigate the characteristics and quality of communication links of data rate 1.56 GB/s and wavelength of 1550 nm. The SS-WDM technique has been inspected for 4, 8 and 16 channels to increase the performance of communication under various weather conditions. The proposed model is susceptible to system degradation due to turbulences where wind velocity, refractive index and height of buildings have been majorly focused. A case study has been experimented on how the height of buildings around VIT, Vellore campus interfere the transmission of light in free space. Based on the above study, the results shows that the benefits of spectrum slicing wavelength division multiplexing (SS-WDM) have been worked up on for the climatic conditions which enhance performance of system. Moreover, the graphs plotted against bit error rate (BER), attenuation and distance makes the analysis better which highlights the characteristic features of SS-WDM.

  1. Dynamic link load balancing based integrated routing algorithm in IP-over-WDM networks

    Science.gov (United States)

    Zhang, Zhizhong; Zhang, Yunlin; Zeng, Qingji; Wang, Jianxin; Ye, Tong; Zhou, Yuli

    2004-04-01

    Integrated routing is a routing approach to support the peer interconnection model in IP over WDM networks. To have a better network link load distribution and network usage in IP over WDM networks, in which network nodes may have the ability to handle traffic in fine granularities, it is important to take into account the combined routing at the IP and WDM layers. Based upon this, this paper develops an algorithm for integrated dynamic routing of bandwidth guaranteed paths in IP over WDM networks. For newly dynamic arriving requests, as the developed algorithm takes into account the combined topology and resource usage information at the IP and WDM layers, and the routing procedure makes full use of the statistic information of the users" bandwidth requirement and considers carefully both the routing cost and the corresponding length of the routing path, thus a better link load balancing and network usage can be achieved. Simulation results show that the developed scheme performs well in terms of performance metrics such as the number of rejected demands and the network link load balancing.

  2. All-optical 40Gbit/s OTDM to 2x20Gbit/s WDM signal-format translation

    DEFF Research Database (Denmark)

    Jørgensen, Carsten; Danielsen, Søren Lykke; Mikkelsen, Benny

    1996-01-01

    40Gbit/s OTDM to 2 x 20 Gbit/s WDM signal-format translation is demonstrated using a cross-gain modulation in a semiconductor optical amplifier designed for high-speed operation. Excellent performance is demonstrated by polarisation-independent operation, showing clear eye diagrams and high...... extinction ratios for the translated WDM-channels....

  3. Experimental Investigation of WDM transmission properties for optical labeled signals using orthogonal IM/FSK modulation format

    DEFF Research Database (Denmark)

    Holm-Nielsen, Pablo Villanueva; Zhang, Jianfeng; Olmos, J. J. Vegas

    2004-01-01

    In this paper we report on WDM transmission of optical labeled signals using the orthogonal IM/FSK modulation format aimed for optical packet/burst switching. WDM transmission in both a point-to-point transmission system and a demonstration network with a label-swapping node are implemented....

  4. All-Optical Ultra-High-Speed OFDM to Nyquist-WDM Conversion Based on Complete Optical Fourier Transformation

    DEFF Research Database (Denmark)

    Guan, Pengyu; Røge, Kasper Meldgaard; Mulvad, Hans Christian Hansen

    2016-01-01

    We propose a novel all-optical ultra-high-speed orthogonal frequency-division multiplexing (OFDM) to Nyquist wavelength-division multiplexing (Nyquist-WDM) conversion scheme, achieved by exchanging the temporal and spectral profiles using a complete optical Fourier transformation (OFT). This scheme...... enables high-speed OFDM to Nyquist-WDM conversion without complex optical/electrical/optical conversion. The all-optical OFDM transmitter is based on the generation of OFDM symbols with a low duty cycle by rectangular temporal gating, which in combination with optical time-division multiplexing yields...... a higher symbol-rate OFDM signal. In the receiver, the converted Nyquist-WDM super-channel is WDM demultiplexed into individual Nyquist-WDM channels using a rectangular optical bandpass filter, followed by optical sampling at the intersymbol-interference free point. In the experimental demonstration...

  5. WDM extended reach passive optical networks using OFDM-QAM.

    Science.gov (United States)

    Chow, Chi-Wai; Yeh, Chien-Hung; Wang, Chia-Hsuan; Shih, Fu-Yuan; Pan, Ci-Ling; Chi, Sien

    2008-08-04

    In order to reduce the cost for delivering future broadband services, network operators are inclined to simplify the network architectures by integrating the metro and access networks into a single system. Hence, extended reach passive optical networks (ER-PONs) have been proposed. ER-PON usually has four new features: high data rate in both upstream and downstream signals (>1 Gb/s); reach extension to >100 km; a high split ratio (>100); and using wavelength division multiplexing (WDM). In this work, we propose and demonstrate a highly spectral efficient ER-PON using 4 Gb/s OFDM-QAM for both upstream and downstream signals, while achieving a high split-ratio of 256. The ER-PON employs optical components optimized for GPON (bandwidth of approximately 1 GHz) and reaches 100 km without dispersion compensation. Numerical analysis using 16, 64 and 256-QAM OFDM are also performed to study the back-to-back receiver sensitivities and power penalties at different electrical driving ratios.

  6. Fiber-optic perimeter security system based on WDM technology

    Science.gov (United States)

    Polyakov, Alexandre V.

    2017-10-01

    Intelligent underground fiber optic perimeter security system is presented. Their structure, operation, software and hardware with neural networks elements are described. System allows not only to establish the fact of violation of the perimeter, but also to locate violations. This is achieved through the use of WDM-technology division spectral information channels. As used quasi-distributed optoelectronic recirculation system as a discrete sensor. The principle of operation is based on registration of the recirculation period change in the closed optoelectronic circuit at different wavelengths under microstrain exposed optical fiber. As a result microstrain fiber having additional power loss in a fiber optical propagating pulse, which causes a time delay as a result of switching moments of the threshold device. To separate the signals generated by intruder noise and interference, the signal analyzer is used, based on the principle of a neural network. The system detects walking, running or crawling intruder, as well as undermining attempts to register under the perimeter line. These alarm systems can be used to protect the perimeters of facilities such as airports, nuclear reactors, power plants, warehouses, and other extended territory.

  7. A Dynamic Resilience Approach for WDM Optical Networks

    Science.gov (United States)

    Garg, Amit Kumar

    2017-12-01

    Optical fibres have been developed as a transmission medium to carry traffic in order to provide various services in telecommunications platform. Failure of this fibre caused loss of data which can interrupt communication services. This paper has been focused only on survivable schemes in order to guarantee both protection and restoration in WDM optical networks. In this paper, a dynamic resilience approach has been proposed whose objective is to route the flows in a way which minimizes the total amount of bandwidth used for working and protection paths. In the proposed approach, path-based protection is utilized because it yields lower overhead and is also suitable for global optimization where, in case of a single link failure, all the flows utilizing the failed link are re-routed to a pre-computed set of paths. The simulation results demonstrate that proposed approach is much more efficient as it provides better quality of services (QoS) in terms of network resource utilization, blocking probability etc. as compared to conventional protection and restoration schemes. The proposed approach seems to offer an attractive combination of features, with both ring like speed and mesh-like efficiency.

  8. Photonic bandgap quasi-crystals for integrated WDM devices

    Science.gov (United States)

    Yankov, Vladimir V.; Babin, Sergey; Ivonin, Igor; Goltsov, Alexander Y.; Morozov, Anatolii; Polonskiy, Leonid; Spector, Michael; Talapov, Andrei; Kley, Ernst-Bernhard; Schmidt, Holger; Dahlgren, Robert P.

    2003-06-01

    A novel concept of Photonic Bandgap Quasi-Crystal (PBQC) as a platform for planar integrated WDM optical devices is proposed. The PBQC can be lithographically fabricated in a planar waveguide as a computer-generated two-dimensional hologram. In this approach the spectral selectivity of Bragg gratings, focusing properties of elliptical mirrors, superposition properties of thick holograms, photonic bandgaps of periodic structures, and flexibility of lithography on planar waveguides are combined. In distinction to conventional combination of independent planar Bragg gratings, in PBQC we create multiple bandgaps by synthesizing a synergetic super-grating of a number of individual sub-gratings. The device spectral selectivity is determined by those of the sub-gratings. The super-grating comprises million(s) of dashes etched on an interface of a planar waveguide. Each dash is a binary feature placed by a computer program to serve simultaneously many channels. For realization of PBQC devices the software for generating super-gratings (GDS-II format) and 2-D simulation of its transfer function was developed. Direct e-beam writing and photolithography were used for manufacturing PBQC structures. For verification of the ideas behind the concept a number of multichannel MUX/DEMUX devices have been manufactured and experimentally tested. The results of detailed experimental study of 4- and 16-channel devices will be presented. Channel isolation ~30 dB was achieved in the 4-channel devices. The applications of PBQC platform for integrated light wave circuits are discussed.

  9. Efficient traffic grooming in SONET/WDM BLSR Networks

    Energy Technology Data Exchange (ETDEWEB)

    Awwal, A S; Billah, A B; Wang, B

    2004-04-02

    In this paper, we study traffic grooming in SONET/WDM BLSR networks under the uniform all-to-all traffic model with an objective to reduce total network costs (wavelength and electronic multiplexing costs), in particular, to minimize the number of ADMs while using the optimal number of wavelengths. We derive a new tighter lower bound for the number of wavelengths when the number of nodes is a multiple of 4. We show that this lower bound is achievable. All previous ADM lower bounds except perhaps that in were derived under the assumption that the magnitude of the traffic streams (r) is one unit (r = 1) with respect to the wavelength capacity granularity g. We then derive new, more general and tighter lower bounds for the number of ADMs subject to that the optimal number of wavelengths is used, and propose heuristic algorithms (circle construction algorithm and circle grooming algorithm) that try to minimize the number of ADMs while using the optimal number of wavelengths in BLSR networks. Both the bounds and algorithms are applicable to any value of r and for different wavelength granularity g. Performance evaluation shows that wherever applicable, our lower bounds are at least as good as existing bounds and are much tighter than existing ones in many cases. Our proposed heuristic grooming algorithms perform very well with traffic streams of larger magnitude. The resulting number of ADMs required is very close to the corresponding lower bounds derived in this paper.

  10. Wavelength dimensioning for wavelength-routed WDM satellite network

    Directory of Open Access Journals (Sweden)

    Liu Zhe

    2016-06-01

    Full Text Available Internet and broadband applications driven by data traffic demand have become key drivers for satellite constellations. The key technology to satisfy the high capacity requirements between satellites is optical satellite networks by means of wavelength division multiplexing inter-satellite links (ISLs with wavelength routing (WDM-OSN. Due to the limited optical amplifier bandwidth onboard the satellite, it is important to minimize the wavelength requirements to provision requests. However, ISLs should be dynamically established and deleted for each satellite according to its visible satellites. Furthermore, different link assignments will result in different topologies, hence yielding different routings and wavelength assignments. Thus, a perfect match model-based link assignment scheme (LAS-PMM is proposed to design an appropriate topology such that shorter path could be routed and less wavelengths could be assigned for each ISL along the path. Finally, simulation results show that in comparison to the regular Manhattan street network (MSN topology, wavelength requirements and average end-to-end delay based on the topology generated by LAS-PMM could be reduced by 24.8% and 12.4%, respectively.

  11. Ion beam focusing with cone optics for WDM experiments

    Energy Technology Data Exchange (ETDEWEB)

    Hasegawa, Jun, E-mail: jun.hasegawa@es.titech.ac.jp [Department of Energy Sciences, Tokyo Institute of Technology, 4259 Nagatsuta-cho, Midori-ku, Yokohama 226-8502 (Japan); Kondo, Kotaro; Oguri, Yoshiyuki [Research Laboratory for Nuclear Reactors, 2-12-1 Ookayama, Meguro-ku, Tokyo 152-8550 (Japan); Horioka, Kazuhiko [Department of Energy Sciences, Tokyo Institute of Technology, 4259 Nagatsuta-cho, Midori-ku, Yokohama 226-8502 (Japan)

    2014-01-01

    Beam focusing properties of cone optics were systematically investigated by Monte Carlo simulations under various combinations of beam and cone parameters. To optimize the cone optic design for accelerator-driven WDM experiments, the beam intensity gains after cone focusing were evaluated from the simulation results as functions of cone wall material and shape parameters such as taper angle and wall curvature. The uniformity of the cone-focused beam was also examined by considering not only various cone parameters but also the cases involving the misalignment of the cone optic. From the results, a parabolic gold cone was found to be the best choice at least for relatively light ions such as lithium having MeV energies. It is also found that although smaller taper angle improves the total beam transport efficiency in the optic, it brings more difficulties in the alignment of the optic because the alignment accuracy should be less than a half of the taper angle to obtain acceptable uniformity in the beam energy deposition on the target.

  12. An area-efficient network interface for a TDM-based Network-on-Chip

    DEFF Research Database (Denmark)

    Sparsø, Jens; Kasapaki, Evangelia; Schoeberl, Martin

    2013-01-01

    Network interfaces (NIs) are used in multi-core systems where they connect processors, memories, and other IP-cores to a packet switched Network-on-Chip (NOC). The functionality of a NI is to bridge between the read/write transaction interfaces used by the cores and the packet-streaming interface...... used by the routers and links in the NOC. The paper addresses the design of a NI for a NOC that uses time division multiplexing (TDM). By keeping the essence of TDM in mind, we have developed a new area-efficient NI micro-architecture. The new design completely eliminates the need for FIFO buffers...... and credit based flow control - resources which are reported to account for 50–85% of the area in existing NI designs. The paper discusses the design considerations, presents the new NI micro-architecture, and reports area figures for a range of implementations....

  13. Throughput of Type II HARQ-OFDM/TDM Using MMSE-FDE in a Multipath Channel

    Directory of Open Access Journals (Sweden)

    Haris Gacanin

    2009-01-01

    Full Text Available In type II hybrid ARQ (HARQ schemes, the uncoded information bits are transmitted first, while the error correction parity bits are sent upon request. Consequently, frequency diversity cannot be exploited during the first transmission. In this paper, we present the use of OFDM/TDM with MMSE-FDE and type II HARQ to increase throughput of OFDM due to frequency diversity gain.

  14. Dynamic wired-wireless architecture for WDM stacking access networks

    Directory of Open Access Journals (Sweden)

    Gustavo Adolfo Puerto-Leguizamón

    2014-01-01

    Full Text Available Este artículo presenta una arquitectura dinámica para redes de acceso convergentes fijas e inalámbricas en red óptica pasiva ( PON basada en multiplexación en división de tiempo (TDM bajo el pa radigma de apilamiento de longitudes de onda. Cuatro longitudes de onda para servicios fijos transportando una carga de tráfico de 10 Gb/s, una longitud de onda reconfigurable extra y una longi tud de onda común a todas las unidades de red óptica (ONU para el transpor te de servicios inalámbricos se enviaron a una PON con un relac ión de división de 1:64. En la ONU un filtro sintonizable basado en óp tica de Fourier de espacio libre selecciona una de las longitud es de onda que transporta servicios fijos y un filtro basado en redes de d ifracción de Bragg (FBG extrae la longitud de onda que transpo rta servicios inalámbricos. En el enlace de subida se utilizó multiplexación por división de subportadora (SCM para el transporte combinado de señales en banda base e inalámbricas a la oficina central (CO.

  15. Bi-directional small form pluggable optical transceiver using an integrated WDM optical subassembly

    Science.gov (United States)

    Yoon, Hyun-Jae; Cho, Hyun-Woo; Cho, Young-Uk; Kim, Ki-Dae

    2006-09-01

    The 1.3/1.55 μm bi-directional small form pluggable (SFP) optical transceiver with an integrated wavelength division multiplexing (WDM) subassembly using accurate ceramic blocks has been developed. The WDM subassembly on which a laser diode (LD), a receiver photodiode (r-PD), a WDM filter, and two micro lenses are integrated is only 2.0 x 2.1 x 0.6 mm 3 in size and inserted in a TO-CAN package. The SFP transceiver coupled with single mode fiber has been operated at a 622Mbps data rate. The transmitted optical output power is -2.8 dBm and the measured value of sensitivity is -32 dBm at 10 -10 Bit Error Rate (BER).

  16. Energy-efficient WDM-OFDM-PON employing shared OFDM modulation modules in optical line terminal.

    Science.gov (United States)

    Hu, Xiaofeng; Zhang, Liang; Cao, Pan; Wang, Kongtao; Su, Yikai

    2012-03-26

    We propose and experimentally demonstrate a scheme to improve the energy efficiency of wavelength division multiplexing - orthogonal frequency division multiplexing - passive optical networks (WDM-OFDM-PONs). By using an N × M opto-mechanic switch in optical line terminal (OLT), an OFDM modulation module is shared by several channels to deliver data to multiple users with low traffic demands during non-peak hours of the day, thus greatly reducing the number of operating devices and minimizing the energy consumption of the OLT. An experiment utilizing one OFDM modulation module to serve three optical network units (ONUs) in a WDM-OFDM-PON is performed to verify the feasibility of our proposal. Theoretical analysis and numerical calculation show that the proposed scheme can achieve a saving of 23.6% in the energy consumption of the OFDM modulation modules compared to conventional WDM-OFDM-PON.

  17. [Cost-effectiveness analysis of active TDM in elderly patients treated with aminoglycosides].

    Science.gov (United States)

    Leon-Djian, Cécile Burgos; Bourguignon, Laurent; Späth, Hans-Martin; Maire, Pascal

    2011-01-01

    Aminoglycoside antibiotics use has been limited by the risk of toxicity and their pharmacokinetic variability, thus requiring therapeutic drug monitoring (TDM). As elderly patients are particularly at risk of accumulation, active therapeutic drug monitoring (ATM) can be performed using a Bayesian method. The objective was to analyse the clinical and economic impact of ATM in elderly patients. A two-year retrospective study was performed to compare two geriatric hospitals, one using ATM (SG1) and the other using non-guided TDM (SG2). Efficacy was evaluated by internal reference to target concentration. Direct medical costs were research. Cost-effectiveness results expressed as ratios. In SG1 56 patients received aminoglycosides and 47 patients in SG2. The cost per patient was 114 € for ATM and 165 € for non-guided TDM. The sensitivity analysis confirmed these results. ATM for aminoglycoside is better on three criteria: efficacy, toxicity and cost. © 2011 Société Française de Pharmacologie et de Thérapeutique.

  18. On Channel Estimation for OFDM/TDM Using MMSE-FDE in a Fast Fading Channel

    Directory of Open Access Journals (Sweden)

    Gacanin Haris

    2009-01-01

    Full Text Available Abstract MMSE-FDE can improve the transmission performance of OFDM combined with time division multiplexing (OFDM/TDM, but knowledge of the channel state information and the noise variance is required to compute the MMSE weight. In this paper, a performance evaluation of OFDM/TDM using MMSE-FDE with pilot-assisted channel estimation over a fast fading channel is presented. To improve the tracking ability against fast fading a robust pilot-assisted channel estimation is presented that uses time-domain filtering on a slot-by-slot basis and frequency-domain interpolation. We derive the mean square error (MSE of the channel estimator and then discuss a tradeoff between improving the tracking ability against fading and the noise reduction. The achievable bit error rate (BER performance is evaluated by computer simulation and compared with conventional OFDM. It is shown that the OFDM/TDM using MMSE-FDE achieves a lower BER and a better tracking ability against fast fading in comparison with conventional OFDM.

  19. Field Trial of 40 Gb/s Optical Transport Network using Open WDM Interfaces

    DEFF Research Database (Denmark)

    Fagertun, Anna Manolova; Ruepp, Sarah Renée; Petersen, Martin Nordal

    2013-01-01

    An experimental field-trail deployment of a 40Gb/s open WDM interface in an operational network is presented, in cross-carrier interconnection scenario. Practical challenges of integration and performance measures for both native and alien channels are outlined.......An experimental field-trail deployment of a 40Gb/s open WDM interface in an operational network is presented, in cross-carrier interconnection scenario. Practical challenges of integration and performance measures for both native and alien channels are outlined....

  20. Study of converged 60 GHz radio over fiber with WDM-PON access networks

    OpenAIRE

    Shao, Tong

    2012-01-01

    Recently, convergence of 60 GHz radio over fiber (RoF) technique with wavelength division multiplexing (WDM) passive optical networks (PON) has raised great interests because it provides the possibility for simultaneous broadband 60 GHz signal generation and multi-gigabit per second wireline transmission. The objective of the thesis is to study the solutions for converged 60 GHz RoF and WDM-PON technique.In this thesis, we have made the following achievements for RoF technology and the integr...

  1. Combined Optical and Electrical Spectrum Shaping for High-Baud-Rate Nyquist-WDM Transceivers

    DEFF Research Database (Denmark)

    Porto da Silva, Edson; Borkowski, Robert; Preussler, Stefan

    2016-01-01

    . To investigate the benefits of the proposed approach, we demonstrate 32 the first WDM Nyquist-OTDM signal generation based on the periodic train of sinc pulses 33 and electrical spectrum shaping. Straight line transmission of five 112.5-Gbd Nyquist- 34 OTDM dual-polarization quadrature phase-shift keying (QPSK...... bandwidth is related to the optical comb parameters 25 and the pulse shaping of the modulating waveforms in the electrical domain. Such de- 26 pendence may result in broadening of the modulated spectra, which can degrade the 27 performance of Nyquist-WDM systems due to interchannel crosstalk penalties...

  2. 16 channel WDM regeneration in a single phase-sensitive amplifier through optical Fourier transformation

    DEFF Research Database (Denmark)

    Guan, Pengyu; Da Ros, Francesco; Lillieholm, Mads

    2016-01-01

    We demonstrate simultaneous phase regeneration of 16-WDM DPSK channels using optical Fourier transformation and a single phase-sensitive amplifier. The BERs of 16-WDM×10-Gbit/s phase noise degraded DPSK signals are improved by 0.4-1.3 orders of magnitude......We demonstrate simultaneous phase regeneration of 16-WDM DPSK channels using optical Fourier transformation and a single phase-sensitive amplifier. The BERs of 16-WDM×10-Gbit/s phase noise degraded DPSK signals are improved by 0.4-1.3 orders of magnitude...

  3. Investigation of Cross-Phase Modulation in WDM Systems with NRZ and RZ Modulation Formats

    DEFF Research Database (Denmark)

    Yu, Jianjun; Jeppesen, Palle

    2000-01-01

    Our experimental and numerical results show that there is no large difference of XPM-induced intensity interferences between NRZ and RZ format with a duty cycle larger than a certain value in WDM systems of multi-span SMF or TW fibers.......Our experimental and numerical results show that there is no large difference of XPM-induced intensity interferences between NRZ and RZ format with a duty cycle larger than a certain value in WDM systems of multi-span SMF or TW fibers....

  4. Fiber nonlinearity compensation of an 8-channel WDM PDM-QPSK signal using multiple phase conjugations

    DEFF Research Database (Denmark)

    Hu, Hao; Jopson, R. M.; Dinu, M.

    2013-01-01

    We demonstrate compensation of fiber nonlinearities using optical phase conjugation of an 8-chamiel WDM 32-Gbaud PDM QPSK signal. Conjugating phase every 600 km in a fiber loop enabled a 6000 km transmission over True Wave fiber. © 2013 Optical Society of America.......We demonstrate compensation of fiber nonlinearities using optical phase conjugation of an 8-chamiel WDM 32-Gbaud PDM QPSK signal. Conjugating phase every 600 km in a fiber loop enabled a 6000 km transmission over True Wave fiber. © 2013 Optical Society of America....

  5. Performance analysis of TCP traffic and its influence on ONU's energy saving in energy efficient TDM-PON

    Science.gov (United States)

    Alaelddin, Fuad Yousif Mohammed; Newaz, S. H. Shah; Lee, Joohyung; Uddin, Mohammad Rakib; Lee, Gyu Myoung; Choi, Jun Kyun

    2015-12-01

    The majority of the traffic over the Internet is TCP based, which is very sensitive to packet loss and delay. Existing research efforts in TDM-Passive Optical Networks (TDM-PONs) mostly evaluate energy saving and traffic delay performances under different energy saving solutions. However, to the best of our knowledge, how energy saving mechanisms could affect TCP traffic performance in TDM-PONs has hardly been studied. In this paper, by means of our state-of-art OPNET Modular based TDM-PON simulator, we evaluate TCP traffic delay, throughput, and Optical Network Unit (ONU) energy consumption performances in a TDM-PON where energy saving mechanisms are employed in ONUs. Here, we study the performances under commonly used energy saving mechanisms defined in standards for TDM-PONs: cyclic sleep and doze mode. In cyclic sleep mode, we evaluate the performances under two well-known sleep interval length deciding algorithms (i.e. fixed sleep interval (FSI) and exponential sleep interval deciding (ESID)) that an OLT uses to decide sleep interval lengths for an ONU. Findings in this paper put forward the strong relationship among TCP traffic delay, throughput and ONU energy consumption under different sleep interval lengths. Moreover, we reveal that under high TCP traffic, both FSI and ESID will end up showing similar delay, energy and throughput performance. Our findings also show that doze mode can offer better TCP throughput and delay performance at the price of consuming more energy than cyclic sleep mode. In addition, our results provide a glimpse on understanding at what point doze mode becomes futile in improving energy saving of an ONU under TCP traffic. Furthermore, in this paper, we highlight important research issues that should be studied in future research to maximize energy saving in TDM-PONs while meeting traffic Quality of Service requirements.

  6. Clinical efficacy and safety of T-DM1 for patients with HER2-positive breast cancer

    Directory of Open Access Journals (Sweden)

    Ma B

    2016-02-01

    Full Text Available Bo Ma,1 Qianqian Ma,2 Hongqiang Wang,3 Guolei Zhang,1 Huiying Zhang,1 Xiaohong Wang1 1Affiliated Central Hospital of Huzhou Teachers College, Huzhou, Zhejiang, People’s Republic of China; 2University Hospital of Tuebingen, Tuebingen, Germany; 3Department of Oncology, Hospital of Zhoushan, Zhoushan, Zhejiang, People’s Republic of China Purpose: The aim of this study was to evaluate the therapeutic efficacy and safety of trastuzumab emtansine (T-DM1 for the treatment of patients with human epidermal growth factor receptor 2-positive breast cancer.  Methods: We performed a systemic review and meta-analysis of the relevant published clinical studies. A computerized search was performed for controlled clinical trials of T-DM1 in targeted treatment. Overall survival, progression-free survival, objective response rate, symptom progression free, and adverse events (AEs were evaluated.  Results: Eight eligible trials with a total of 2,016 patients with breast cancer were included in the present meta-analysis. The treatment of patients with breast cancer with T-DM1 was associated with significantly increased overall and progression-free survival when compared with controls (P<0.0001. An analysis of the objective response rate and symptom progression free also demonstrated favorable results for T-DM1 treatment (P≤0.0001. There was no significant difference between the T-DM1 and control groups with respect to nonhematologic or hematologic AEs (P=0.99 and P=0.30, respectively.  Conclusion: Overall, T-DM1 is efficacious in the treatment of patients with human epidermal growth factor receptor 2-positive breast cancer and low rates of AEs compared with controls. Keywords: breast cancer, meta-analysis, HER2, T-DM1, efficacy

  7. Evaluation expérimentale des performances d'un système hybride WDM/DS-OCDMA

    OpenAIRE

    Cordette, Steevy; Fsaifes, Ihsan; Kibler, Bertrand; Ware, Cédric; Lepers, Catherine; Finot, Christophe; Millot, Guy

    2010-01-01

    National audience; Nous étudions expérimentalement une solution hybride WDM/DS-OCDMA pour l'application réseau d'accès optique haut débit. Cette solution permet d'augmenter la capacité de multiplexage du réseau WDM en y ajoutant une dimension supplémentaire : le code temporel. Le système est réalisé dans une configuration mono-canal WDM. Les performances de la transmission, en termes de taux d'erreurs binaires, sont évaluées après 20 km de transmission.

  8. Power consumption comparison between point-to-point WDM and OTDM systems

    DEFF Research Database (Denmark)

    Xu, Jing; Peucheret, Christophe; Jeppesen, Palle

    2010-01-01

    an energy efficiency point of view. Our analysis shows that in order to be comparable to WDM systems in power consumption aspect, the topology of the demultiplexing unit in OTDM systems must be carefully chosen and optimized and trade-offs have to be made between speed and power consumption using state...

  9. OTDM to WDM format conversion based on cascaded SHG/DFG in a single PPLN waveguide

    OpenAIRE

    Liu, S.; Lee, K. J.; Parmigiani, F.; Ibsen, M.; Petropoulos, P.; Richardson, D.J.; K Gallo

    2010-01-01

    We propose and experimentally demonstrate error-free OTDM to WDM format conversion based on cSHG/DFG within a 30mm-long PPLN waveguide and a time-to-frequency domain conversion approach, which relies upon switching a linearly chirped pulse.

  10. Demonstration of digital fronthaul over self-seeded WDM-PON in commercial LTE environment.

    Science.gov (United States)

    Ma, Yiran; Xu, Zhiguang; Zhang, Chengliang; Lin, Huafeng; Wang, Qing; Zhou, Min; Wang, Heng; Yu, Jingwen; Wang, Xiaomu

    2015-05-04

    CPRI between BBU and RRU equipment is carried by self-seeded WDM-PON prototype system within commercial LTE end-to-end environment. Delay and jitter meets CPRI requirements while services demonstrated show the same performance as bare fiber.

  11. GigaWaM—Next-Generation WDM-PON Enabling Gigabit Per-User Data Bandwidth

    DEFF Research Database (Denmark)

    Prince, Kamau; Gibbon, Timothy Braidwood; Rodes Lopez, Roberto

    2012-01-01

    The “Gigabit access passive optical network using wavelength division multiplexing” project aims to implement 64-Gb/s data transmission over 20-km single-mode fiber. Per-user symmetric data rates of 1-Gb/s will be achieved using wavelength division multiplexing passive optical network (WDM...

  12. Twelve factors critical to the success of WDM at the policy and at the ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    IDRC CRDI

    generally causes only minor economic disruption, but similar rural initiatives can be more disruptive. 5. Urban WDM agencies can be independent and prioritize pricing. ... is no single model that works for all audiences in all countries or regions. Finding the right model is likely to involve a careful process of trial and error.

  13. Experimental Study of Nonlinear Phase Noise and its Impact on WDM Systems with DP-256QAM

    DEFF Research Database (Denmark)

    Yankov, Metodi Plamenov; Da Ros, Francesco; Porto da Silva, Edson

    2016-01-01

    A probabilistic method for mitigating the phase noise component of the non-linear interference in WDM systems with Raman amplification is experimentally demonstrated. The achieved gains increase with distance and are comparable to the gains of single-channel digital back-propagation....

  14. Key lessons: Twelve factors critical to the success of WDM at the ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Water demand management (WDM) programs have been widely implemented across the MENA region and elsewhere, with varying degrees of success. The criteria below are intended to help policymakers determine how best to develop institutions with the capacity and capability to design, implement and monitor WDM ...

  15. Tailored design of WDM filters in BCB embedded PhC membranes

    DEFF Research Database (Denmark)

    Malaguti, Stefania; Bellanca, Gaetano; Ottaviano, Luisa

    2013-01-01

    We propose a design strategy for wavelength division multiplexing (WDM) filters in BCB embedded photonic crystal membranes. Due to the weaker vertical confinement determined by the material embedding the whole structure, accurate tailoring of the resonant cavity and of both bus and drop waveguide...

  16. Integration of Optically Generated Impulse Radio UWB Signals into Baseband WDM-PON

    DEFF Research Database (Denmark)

    Pham, Tien Thang; Yu, Xianbin; Dittmann, Lars

    2011-01-01

    We propose a compact integration system to simultaneously provide wireline and wireless (baseband and ultra-wide band (UWB)) services to end-users in a WDM-PON. A 1-Gbps UWB signal is optically generated and shares the same wavelength with the baseband signal. Error-free performance was achieved ...

  17. MIMO-OFDM WDM PON with DM-VCSEL for femtocells application

    DEFF Research Database (Denmark)

    Binti Othman, Maisara; Deng, Lei; Pang, Xiaodan

    2011-01-01

    We report on experimental demonstration of 2x2 MIMO-OFDM 5.6-GHz radio over fiber signaling over 20 km WDM-PON with directly modulated (DM) VCSELs for femtocells application. MIMO-OFDM algorithms effectively compensate for impairments in the wireless link. Error-free signal demodulation of 64...

  18. Increasing the cost-constrained availability of WDM Networks with Degree-3 Structured Topologies

    DEFF Research Database (Denmark)

    Gutierrez Lopez, Jose Manuel; Georgakilas, Kostas; Katrinis, Kostas

    2010-01-01

    This paper studies the impact of node degree distribution to availability and capital and deployment expenditure of optical WDM transport networks. Three structured degree-3 graphs with fair node degree distribution are proposed in this context. Using a realistic network optimization framework...

  19. Electronic post-compensation of WDM transmission impairments using coherent detection and digital signal processing.

    Science.gov (United States)

    Li, Xiaoxu; Chen, Xin; Goldfarb, Gilad; Mateo, Eduardo; Kim, Inwoong; Yaman, Fatih; Li, Guifang

    2008-01-21

    A universal post-compensation scheme for fiber impairments in wavelength-division multiplexing (WDM) systems is proposed based on coherent detection and digital signal processing (DSP). Transmission of 10 x 10 Gbit/s binary-phase-shift-keying (BPSK) signals at a channel spacing of 20 GHz over 800 km dispersion shifted fiber (DSF) has been demonstrated numerically.

  20. On-chip, CMOS-compatible, hardware-compressive integrated photonic beamformer based on WDM

    NARCIS (Netherlands)

    Burla, M.; Zhuang, L.; Marpaung, D.A.I.; Khan, M.R.H.; Leinse, Arne; Beeker, Willem; Hoekman, M.; Heideman, Rene; Roeloffzen, C.G.H.

    2013-01-01

    We propose and experimentally demonstrate a novel, hardware-compressive architecture for broadband and continuously tunable integrated optical true-time-delay beamformers. The architecture is based on on-chip wavelength division multiplexing (WDM) that, in conjunction with the frequency-periodic

  1. A 80 km reach fully passive WDM-PON based on reflective ONUs

    DEFF Research Database (Denmark)

    Presi, Marco; Proietti, Roberto; Prince, Kamau

    2008-01-01

    We propose a novel line coding combination (Inverse RZ coding in downlink and RZ in uplink) that extends the reach of WDM Passive Optical Networks based on Reflective SOAs with no in-line amplification. We achieved full downstream remodulation even when feeding the reflective SOA with power level...

  2. Simultaneous regeneration of two 160 Gbit/s WDM channels in a single highly nonlinear fiber

    DEFF Research Database (Denmark)

    Wang, Ju; Ji, Hua; Hu, Hao

    2013-01-01

    We experimentally demonstrate simultaneous all-optical regeneration of two 160-Gbit/s wavelength-division multiplexed (WDM) channels in a single highly nonlinear fiber (HNLF). The multi-channel regeneration performance is confirmed by bit-error rate (BER) measurements. The receiver powers at a BER...

  3. WDM packet switch architectures and analysis of the influence of tunable wavelength converters on the performance

    DEFF Research Database (Denmark)

    Danielsen, Søren Lykke; Mikkelsen, Benny; Jørgensen, Carsten

    1997-01-01

    A detailed analytical traffic model for a photonic wavelength division multiplexing (WDM) packet switch block is presented and the requirements to the buffer size is analyzed. Three different switch architectures are considered, each of them representing different complexities in terms of component...

  4. Multi-granularity grooming using timing information in optical networks with waveband and TDM switching

    OpenAIRE

    Tabarak allah Ali Mohamed; Salwa El-Sabban; Gamal Abdel Fadeel Mohamed Khalaf

    2014-01-01

    In this paper, we incorporate the idea of waveband switching in Mixed Line Rates (MLR) network design to address the problem of dynamic traffic grooming in waveband switching networks by investigating a cost function which take the effect of call holding time on the time slot assignment process of in WDM–TDM. Use has been made of Markov model in order to predict the wavelength congestion. A routing algorithm is developed based on the Markov modeling. The results are compared with existing rou...

  5. Online traffic grooming using timing information in WDM–TDM networks

    Directory of Open Access Journals (Sweden)

    Tabarak allah Ali Mohamed

    2013-03-01

    Full Text Available In this paper, the effect of holding time awareness on the process of time slot assignment in WDM–TDM is considered. Use has been made of Markov model in order to predict the wavelength congestion. A routing algorithm is developed based on the Markov modeling. The results are compared with existing algorithms—ASP, WSP and OTGA. Validation results have shown that the performance of the system is significantly improved in terms of bandwidth blocking ratio, network utilization and fairness.

  6. Time lens based optical fourier transformation for advanced processing of spectrally-efficient OFDM and N-WDM signals

    DEFF Research Database (Denmark)

    Guan, Pengyu; Røge, Kasper Meldgaard; Morioka, Toshio

    2016-01-01

    We review recent progress in the use of time lens based optical Fourier transformation for advanced optical signal processing, with focus on all-optical generation, detection and format conversion of spectrally-efficient OFDM and N-WDM signals.......We review recent progress in the use of time lens based optical Fourier transformation for advanced optical signal processing, with focus on all-optical generation, detection and format conversion of spectrally-efficient OFDM and N-WDM signals....

  7. Photonic crystal fibers used in a multi-wavelength source and as transmission fiber in a WDM system

    DEFF Research Database (Denmark)

    Andersen, Peter Andreas; Zsigri, Beata; Peucheret, Christophe

    2004-01-01

    We present a WDM system based entirely on photonic crystal fibers. It includes a novel dispersion flattened highly nonlinear PCF to generate supercontinuum used in a multiwavelength pulse source and a 5.6 km transmission PCF.......We present a WDM system based entirely on photonic crystal fibers. It includes a novel dispersion flattened highly nonlinear PCF to generate supercontinuum used in a multiwavelength pulse source and a 5.6 km transmission PCF....

  8. Exploring crosstalk noise generated in the N-port router used in the WDM-based ONoC

    Science.gov (United States)

    Zhang, Zhendong; Xie, Yiyuan; Song, Tingting; He, Chao; Li, Jiachao; Liu, Yong

    2017-07-01

    Compared with optical network-on-chip (ONoC) with single wavelength, ONoC adopting wavelength division multiplexing (WDM) technology possesses a very prominent advantage-higher bandwidth. Therefore, WDM-based ONoC has been considered one of the most promising ways to relieve the rapidly increasing traffic load in communication systems. A WDM-based router, as the core equipment of WDM-based ONoC, is influenced by crosstalk noise, especially the nonlinear crosstalk noise generated by the four-wave mixing effect. Thus, to explore the performance of the N-port nonblocking optical router using WDM, we propose a universal analytic model to analyze the transmission loss, crosstalk noise, optical signal-to-noise ratio (OSNR), and bit error ratio (BER). The research results show that crosstalk noise varies along with signals at different wavelengths in the same channel. For signals with the same wavelength, the noises generated in the different transmission paths are obviously different from each other. For research of transmission loss, OSNR, and BER, similar results can be obtained. Based on the eye diagrams, we can learn that crosstalk noise will cause signal distortion to a certain extent. With this model, capability of this kind of multiport optical router using WDM can be understood conveniently.

  9. An integrated routing protocol in next-generation IP over WDM networks

    Science.gov (United States)

    Yin, Yong; Kuo, Geng-Sheng

    2004-09-01

    In next-generation IP over WDM networks, lightpaths are set up or torn down dynamically. Traditionally, OSPF in IP layer and OSPF-TE in optical layer disseminate routing information independently. Obviously, this 2-layer routing mechanism is complex and O&M cost is high. Furthermore, in a dynamic environment, both OSPF-TE and OSPF have very heavy control overheads when lightpaths change frequently. In this paper, an integrated routing protocol is proposed. The link state information of both IP layer and optical layer is disseminated simultaneously using the same routing protocol messages. The proposed protocol also advertises wavelength availability information if necessary in order to reduce the blocking probability of routing and wavelength assignment (RWA) algorithm. This proposed integrated protocol is very simple. Furthermore, its control overhead can be reduced from several to about ten times. In addition, RWA's performance is also improved. Hence, the performance of the IP over WDM networks will be improved greatly and significantly.

  10. All-optical code routing in interconnected optical CDMA and WDM ring networks.

    Science.gov (United States)

    Deng, Yanhua; Fok, Mable P; Prucnal, Paul R; Wang, Ting

    2010-11-01

    We propose an all-optical hybrid network composed of optical code division multiple access (CDMA) rings interconnecting through a reconfigurable wavelength division multiplexing (WDM) metro area ring. This network retains the advantages of both the optical CDMA and WDM techniques, including asynchronous access and differentiated quality of service, while removing the hard limit on the number of subscribers and increasing network flexibility. The all-optical network is enabled by using nonlinear optical loop mirrors in an add/drop router (ADR) that performs code conversion, dropping, and switching asynchronously. We experimentally demonstrate the functionalities of the ADR in the proposed scheme asynchronously and obtain error-free performance. The bit-error rate measurements show acceptable power penalties for different code routes.

  11. Transmission performance analysis of WDM systems based on bismuth-doped phosphate glass fiber amplifiers

    Science.gov (United States)

    Ji, Jianhua; Huang, Qian; Wang, Ke; Xu, Ming; Jiang, Chun

    2018-01-01

    In this paper transmission performance of Allwave fiber WDM systems cascaded by bismuth-doped phosphate glass fiber amplifiers pumped by 808 nm lasers is analyzed for the first time, to the best of our knowledge. The rate and power propagation equations of a three-level system are used to model the signal amplification and noise figure in the doped fibers. The simulation results show that the channels in the 1460-1470 nm wavelength region in 32 × 40 Gbit/s WDM system with 10 nm channel space can reach a BER less than 1 × 10-9 with the transmission distance more than 600 km, but when the channel space is reduced to 1 nm, the performance of the system is degraded greatly.

  12. Remote interrogation of WDM fiber-optic intensity sensors deploying delay lines in the virtual domain.

    Science.gov (United States)

    Montero, David Sánchez; Vázquez, Carmen

    2013-05-07

    In this work a radio-frequency self-referencing WDM intensity-based fiber-optic sensor operating in reflective configuration and using virtual instrumentation is presented. The use of virtual delay lines at the reception stage, along with novel flexible self-referencing techniques, and using a single frequency, avoids all-optical or electrical-based delay lines approaches. This solution preserves the self-referencing and performance characteristics of the proposed WDM-based optical sensing topology, and leads to a more compact solution with higher flexibility for the multiple interrogation of remote sensing points in a sensor network. Results are presented for a displacement sensor demonstrating the concept feasibility.

  13. Optical diversity transmission using WDM signal and phase-conjugate lights through multi-core fiber.

    Science.gov (United States)

    Koga, Masafumi; Moroi, Mitsuki; Takara, Hidehiko

    2016-05-02

    This paper proposes a maximum-ratio combining (MRC) scheme for a WDM signal and phase-conjugate pair (PCP) diversity transmission to cancel nonlinear phase-shift. A transfer function approximation for nonlinear phase-shift cancellation is formulated. It shows, with the help of a numerical calculation, that span-by-span chromatic dispersion compensation is more effective than the lumped equivalent at the receiver. This is confirmed in a 2-core diversity 5 channel WDM transmission experiment over 3-spans of 60km MCF with 25 Gbit/s-QPSK PCP. The peak Q-value was enhanced by 3.6dB through MRC, resulting in superior bitrate-distance product and optical power density limit, compared to twice the single core transmission.

  14. Tradeoffs in process strategy games with application in the WDM reconfiguration problem

    DEFF Research Database (Denmark)

    Cohen, Nathann; Coudert, David; Mazauric, Dorian

    2011-01-01

    We consider a variant of the graph searching games that models the routing reconfiguration problem in WDM networks. In the digraph processing game, a team of agents aims at processing, or clearing, the vertices of a digraph D. We are interested in two different measures: (1) the total number...... of agents used, and (2) the total number of vertices occupied by an agent during the processing of D. These measures, respectively, correspond to the maximum number of simultaneous connections interrupted and to the total number of interruptions during a routing reconfiguration in a WDM network. Previous...... works have studied the problem of independently minimizing each of these parameters. In particular, the corresponding minimization problems are APX-hard, and the first one is known not to be in APX. In this paper, we give several complexity results and study tradeoffs between these conflicting...

  15. Fiber nonlinearity-insensitive OSNR monitoring for coherent PM-QPSK-Nyquist-WDM system

    Science.gov (United States)

    Zhang, Peiyu; Xi, Lixia; Yuan, Jin; Tang, Xianfeng; Zhang, Wenbo; Li, Jianping; Zhang, Xiaoguang

    2017-07-01

    We propose a promising fiber nonlinearity-tolerant optical signal-to-noise ratio (OSNR) monitoring technique for high speed long haul polarization multiplexed-quadrature phase shift keying (PM-QPSK) Nyquist wavelength division multiplexing (WDM) coherent optical fiber transmission system, in which the correlation function between the symbols in all states of polarization as well as neighboring channels are exploited instead of the traditional GN model, thus it does not need the prior knowledge of the fiber transmission link nor the complicated integrals. The method is demonstrated to have the OSNR measurement error below 1.28 dB over a wide OSNR range from 10 dB to 28 dB in 100 Gb/s per channel PM-QPSK-Nyquist-WDM system when the launch power is up to 4 dBm and transmission distance is as long as 1600 km.

  16. A Grooming Nodes Optimal Allocation Method for Multicast in WDM Networks

    Directory of Open Access Journals (Sweden)

    Chengying Wei

    2016-01-01

    Full Text Available The grooming node has the capability of grooming multicast traffic with the small granularity into established light at high cost of complexity and node architecture. In the paper, a grooming nodes optimal allocation (GNOA method is proposed to optimize the allocation of the grooming nodes constraint by the blocking probability for multicast traffic in sparse WDM networks. In the proposed GNOA method, the location of each grooming node is determined by the SCLD strategy. The improved smallest cost largest degree (SCLD strategy is designed to select the nongrooming nodes in the proposed GNOA method. The simulation results show that the proposed GNOA method can reduce the required number of grooming nodes and decrease the cost of constructing a network to guarantee a certain request blocking probability when the wavelengths per fiber and transmitter/receiver ports per node are sufficient for the optical multicast in WDM networks.

  17. Remote Interrogation of WDM Fiber-Optic Intensity Sensors Deploying Delay Lines in the Virtual Domain

    Directory of Open Access Journals (Sweden)

    Carmen Vázquez

    2013-05-01

    Full Text Available In this work a radio-frequency self-referencing WDM intensity-based fiber-optic sensor operating in reflective configuration and using virtual instrumentation is presented. The use of virtual delay lines at the reception stage, along with novel flexible self-referencing techniques, and using a single frequency, avoids all-optical or electrical-based delay lines approaches. This solution preserves the self-referencing and performance characteristics of the proposed WDM-based optical sensing topology, and leads to a more compact solution with higher flexibility for the multiple interrogation of remote sensing points in a sensor network. Results are presented for a displacement sensor demonstrating the concept feasibility.

  18. Simultaneous Regeneration of Two 160 Gbit/s WDM Channels in a Single Highly Nonlinear Fiber

    DEFF Research Database (Denmark)

    Wang, Ju; Ji, Hua; Hu, Hao

    2012-01-01

    We experimentally demonstrate simultaneous all-optical regeneration of two 160 Gbit/s WDM channels in a single HNLF using fiber optical parametric amplification. Receiver sensitivities at a BER of 10-9 are improved by about 2.1 dB and 4.9 dB for the two channels, respectively. The BER is not degr......We experimentally demonstrate simultaneous all-optical regeneration of two 160 Gbit/s WDM channels in a single HNLF using fiber optical parametric amplification. Receiver sensitivities at a BER of 10-9 are improved by about 2.1 dB and 4.9 dB for the two channels, respectively. The BER...

  19. Determination of venlafaxine and O-desmethylvenlafaxine in dried blood spots for TDM purposes, using LC-MS/MS

    NARCIS (Netherlands)

    Berm, E J J; Brummel-Mulder, E; Paardekooper, J; Hak, E; Wilffert, B; Maring, J G

    Dried blood spot (DBS) sampling and quantitative analyses of many current therapeutic drug monitoring (TDM)-guided drugs are advantageous because of the minimal invasive sampling strategy. Here, a fast and robust LC-MS/MS method was developed and analytically validated for simultaneous determination

  20. Nonlinear Phase Noise Compensation in Experimental WDM Systems with 256QAM

    DEFF Research Database (Denmark)

    Yankov, Metodi Plamenov; Da Ros, Francesco; Porto da Silva, Edson

    2017-01-01

    Nonlinear phase noise (NLPN) is studied in an experimental wavelength division multiplexed (WDM) system operating at 256QAM. Extremely narrow linewidth lasers (... on the experimental data, the autocorrelation function of the NLPN is estimated and it matches the theoretical predictions. Several algorithms are examined as candidates for tracking and compensating the NLPN. It is shown that algorithms which exploit the distribution of the NLPN achieve higher gains than standard...

  1. Wavelength locking of silicon photonics multiplexer for DML-based WDM transmitter

    OpenAIRE

    Grillanda, Stefano; Ji, Ruiqiang; Morichetti, Francesco; Carminati, Marco; Ferrari, Giorgio; Guglielmi, Emanuele; Peserico, Nicola; Annoni, Andrea; Dede, Alberto; Nicolato, Danilo; Vannucci, Antonello; Klitis, Charalambos; Holmes, Barry; Sorel, Marc; Fu, Shengmeng

    2017-01-01

    We present a wavelength locking platform enabling the feedback control of silicon (Si) microring resonators (MRRs) for the realization of a 4 × 10 Gb/s wavelength-division-multiplexing (WDM) transmitter. Four thermally tunable Si MRRs are employed to multiplex the signals generated by four directly modulated lasers (DMLs) operating in the L-band, as well as to improve the quality of the DMLs signals. Feedback control is achieved through a field-programmable gate array controller by monitoring...

  2. INVESTIGATION ON HYBRID WDM (DWDM+CWDM FREE SPACE OPTICAL COMMUNICATION SYSTEM

    Directory of Open Access Journals (Sweden)

    S. Robinson

    2015-12-01

    Full Text Available Free Space Optical (FSO communication is being realized as an effective solution for future accessing networks, offering light passed through air. The performance of FSO can be primarily degraded by various atmospheric attenuation namely, rain, fog, haze and snow. At present, hybridization of Dense Wavelength Division Multiplexing (DWDM with Coarse Wavelength Division Multiplexing (CWDM becomes necessary to scale the speed and high bandwidth of the services. In this paper, hybrid WDM system is proposed, designed and the network parameters such as Bit Error Rate (BER, Quality Factor and receiver sensitivity are analyzed with respect to link distance for various weather conditions. For investigation, 4 CWDM and 8 DWDM channels are considered whose corresponding channel spacing is 20nm and 0.8nm, respectively. From the simulation, it is investigated that the average link distance of proposed hybrid WDM-FSO system for DWDM and CWDM system at very clear condition are around 810km and 780km. The proposed hybrid WDM based FSO system is designed to handle the quality of transmission for 12 users, each at a data rate of 2.5Gbps.

  3. Multi-granularity grooming using timing information in optical networks with waveband and TDM switching

    Directory of Open Access Journals (Sweden)

    Tabarak allah Ali Mohamed

    2014-06-01

    Full Text Available In this paper, we incorporate the idea of waveband switching in Mixed Line Rates (MLR network design to address the problem of dynamic traffic grooming in waveband switching networks by investigating a cost function which take the effect of call holding time on the time slot assignment process of in WDM–TDM. Use has been made of Markov model in order to predict the wavelength congestion. A routing algorithm is developed based on the Markov modeling. The results are compared with existing routing algorithms – Available Shortest Path (ASP and Online Traffic Grooming Algorithm (OTGA. Validation results have shown that the performance of the proposed system is significantly improved in terms of bandwidth blocking ratio, network utilization as well as port saving due to wavebanding.

  4. Single-PPLN-assisted wavelength-/time-selective switching/dropping/swapping for 100-GHz-spaced WDM signals.

    Science.gov (United States)

    Wang, Jian; Fu, Hongyan; Geng, Dongyu; Willner, Alan E

    2013-02-11

    We propose an approach to implementing wavelength- and time-selective optical switching, dropping and swapping based on the sum-frequency generation (SFG) or cascaded sum- and difference-frequency generation (cSFG/DFG) in a periodically poled lithium niobate (PPLN) waveguide. Analytical solutions are derived, showing the parametric depletion effect for optical switching and the narrow-band operation due to quasi-phase matching (QPM) condition of PPLN. Using parametric depletion effect of SFG process, we demonstrate wavelength- and time-selective optical switching for ITU-grid compatible 40-Gbit/s wavelength-division multiplexed (WDM) signals with a channel spacing of 100 GHz. Less than 1-dB power penalty at a bit-error rate (BER) of 10(-9) is measured for the wavelength- and time-selective switching channel. Negligible impacts are observed on other channels of WDM signals. Using combined effects of parametric depletion and wavelength conversion of cSFG/DFG processes, we demonstrate wavelength- and time-selective optical dropping for ITU-grid compatible 100-GHz-spaced 40-Gbit/s WDM signals. Moreover, we demonstrate optical swapping between two 100-GHz-spaced 40-Gbit/s signals. The obtained theoretical and experimental results confirm single-PPLN-assisted wavelength- and time-selective optical switching, dropping and swapping for 100-GHz-spaced WDM signals, which might potentially be extended to WDM signals with narrower channel spacing.

  5. A receiver-initiated WDM multicast tree construction protocol to support IP dense mode multicast routing in all-optical Lambda-switched networks

    NARCIS (Netherlands)

    Niemegeers, I.G.M.M.; Salvador, M.R.; Heemstra de Groot, S.M.; Dey, D.

    We describe a source-rooted WDM multicast tree construction protocol to support IP dense mode multicast routing protocols in all-optical lambda-switched networks. Using a receiver-initiated approach, the protocol relies on a mechanism that collects information on the capabilities of WDM nodes. This

  6. Preclinical safety profile of trastuzumab emtansine (T-DM1): Mechanism of action of its cytotoxic component retained with improved tolerability

    Energy Technology Data Exchange (ETDEWEB)

    Poon, Kirsten Achilles, E-mail: achilles.kirsten@gene.com [Genentech, Inc., South San Francisco, CA (United States); Flagella, Kelly; Beyer, Joseph [Genentech, Inc., South San Francisco, CA (United States); Tibbitts, Jay [UCB, Brussels (Belgium); Kaur, Surinder; Saad, Ola; Yi, Joo-Hee; Girish, Sandhya; Dybdal, Noel; Reynolds, Theresa [Genentech, Inc., South San Francisco, CA (United States)

    2013-12-01

    Trastuzumab emtansine (T-DM1) is the first antibody-drug conjugate (ADC) approved for patients with human epidermal growth factor receptor 2 (HER2)-positive metastatic breast cancer. The therapeutic premise of ADCs is based on the hypothesis that targeted delivery of potent cytotoxic drugs to tumors will provide better tolerability and efficacy compared with non-targeted delivery, where poor tolerability can limit efficacious doses. Here, we present results from preclinical studies characterizing the toxicity profile of T-DM1, including limited assessment of unconjugated DM1. T-DM1 binds primate ErbB2 and human HER2 but not the rodent homolog c-neu. Therefore, antigen-dependent and non-antigen-dependent toxicity was evaluated in monkeys and rats, respectively, in both single- and repeat-dose studies; toxicity of DM1 was assessed in rats only. T-DM1 was well tolerated at doses up to 40 mg/kg (∼ 4400 μg DM1/m{sup 2}) and 30 mg/kg (∼ 6000 μg DM1/m{sup 2}) in rats and monkeys, respectively. In contrast, DM1 was only tolerated up to 0.2 mg/kg (1600 μg DM1/m{sup 2}). This suggests that at least two-fold higher doses of the cytotoxic agent are tolerated in T-DM1, supporting the premise of ADCs to improve the therapeutic index. In addition, T-DM1 and DM1 safety profiles were similar and consistent with the mechanism of action of DM1 (i.e., microtubule disruption). Findings included hepatic, bone marrow/hematologic (primarily platelet), lymphoid organ, and neuronal toxicities, and increased numbers of cells of epithelial and phagocytic origin in metaphase arrest. These adverse effects did not worsen with chronic dosing in monkeys and are consistent with those reported in T-DM1-treated patients to date. - Highlights: • T-DM1 was well tolerated in preclinical studies in rats and cynomolgus monkeys. • T-DM1 is associated with bone marrow/hematologic, hepatic, and neuronal toxicities. • T-DM1 toxicities are related to DM1 mechanisms of action and pharmacologic

  7. T-DM1, a novel antibody-drug conjugate, is highly effective against uterine and ovarian carcinosarcomas overexpressing HER2

    Science.gov (United States)

    Nicoletti, Roberta; Lopez, Salvatore; Bellone, Stefania; Cocco, Emiliano; Schwab, Carlton L.; Black, Jonathan D.; Centritto, Floriana; Zhu, Liancheng; Bonazzoli, Elena; Buza, Natalia; Hui, Pei; Mezzanzanica, Delia; Canevari, Silvana; Schwartz, Peter E.; Rutherford, Thomas J.; Santin, Alessandro D.

    2014-01-01

    Introduction Ovarian and uterine carcinosarcoma (CS) are characterized by their aggressive clinical behavior and poor prognosis. We evaluated the efficacy of trastuzumab-emtansine (T-DM1), against primary HER2 positive and HER2 negative CS cell lines in vitro and in vivo. Methods Eight primary CS cell lines were evaluated for HER2 amplification and protein expression by FISH, immunohistochemistry, flow cytometry and qRT-PCR. Sensitivity to T-DM1-induced antibody-dependent-cell-mediated-cytotoxicity (ADCC) was evaluated in 4-hr-chromium-release-assays. T-DM1 cytostatic and apoptotic activities were evaluated using flow cytometry based proliferation assays. In vivo activity of T-DM1 was also evaluated. Results HER2 protein overexpression and gene amplification were detected in 25% (2/8) of the primary CS cell lines. T-DM1 and T were similarly effective in inducing strong ADCC against CS overexpressing HER2 at 3+ levels. In contrast, T-DM1 was dramatically more effective than T in inhibiting cell proliferation (P<0.0001) and in inducing G2/M phase cell cycle arrest in the HER2 expressing cell lines (shift of G2/M: mean ± SEM from 14.87 ± 1.23% to 66.57 ± 4.56%, P<0.0001). Importantly, T-DM1 was highly active at reducing tumor formation in vivo in CS xenografts overexpressing HER2 (P=0.0001 and P<0.0001 compared to T and vehicle respectively) with a significantly longer survival when compared to T and vehicle mice (P=0.008 and P=0.0001 respectively). Conclusion T-DM1 may represent a novel treatment option for the subset of HER2 positive CS patients with disease refractory to chemotherapy. PMID:25398397

  8. Compression of 200 GHz DWDM channelized TDM pulsed carrier from optically modelocking WRC-FPLD fiber ring at 10 GHz.

    Science.gov (United States)

    Lin, Yu-Chan; Peng, Guo-Hsuan; Lin, Gong-Ru

    2009-03-30

    The compression of 200GHz DWDM channelized optically mode-locking WRC-FPLD fiber ring pulse of at 10 GHz is performed for high-capacity TDM application. To prevent temporal and spectral cross-talk, the duty-cycle of the DWDM channelized WRC-FPLD FL pulse needs to be shortened without broadening its linewidth. With dual-cavity configuration induced DWDM channelization, a shortest single-channel WRC-FPLD FL pulsewidth of 19 ps is generated, which can be linearly compensated to 10 ps and fifth-order soliton compressed to 1.4 ps. Under a maximum pulsewidth compression ratio up to 14 and a +/-100 m tolerance on compressing fiber length, the single-channel pulsewidth remains DWDM channelized WRC-FPLD FL pulsed carrier is approaching 1% to satisfy at least 256 optical TDM channels.

  9. GreenCommute : the Nortel Networks Transportation Demand Management (TDM) Program on how employers can reduce travel

    Energy Technology Data Exchange (ETDEWEB)

    Lewinson, S. [Nortel Networks, Ottawa, ON (Canada)

    2003-07-01

    This PowerPoint presentation described the GreenCommute, world class commuter option program offered at Nortel Networks in Ottawa, Ontario. Nortel's Ottawa Carling Campus has incorporated popular commuter options in its' site design. These include walking, cycling, transit, car-pooling and teleworking. The Transportation Demand Management (TDM) program was launched to mitigate traffic congestion, minimize infrastructure requirements, and minimize parking areas. The program also acted as a pilot for the region and demonstrated the benefits of public/private sector partnership. The benefits of TDM programs to the employer, employee and community were also highlighted in this presentation. Nortel Networks has launched a comprehensive Internet site which offers commuting information, a self-serve ride matching system, critical links and promotions. It was noted that ongoing government support is critical for modal shifts to occur. Transit service improvements are necessary for transit to be competitive with driving. figs.

  10. Directly-Modulated VCSELs for 2x2 MIMO-OFDM Radio over Fiber in WDM-PON

    DEFF Research Database (Denmark)

    Binti Othman, Maisara; Deng, Lei; Pang, Xiaodan

    2011-01-01

    We demonstrate directly- modulated VCSELs supporting 2x2 MIMO-OFDM 5.6-GHz radio over fiber signaling over 20-km WDM-PON. Error-free signal demodulation of 64-subcarrier 4-QAM signals modulated at 198.5-Mb/s is achieved after fiber and 2-m indoor wireless transmission.......We demonstrate directly- modulated VCSELs supporting 2x2 MIMO-OFDM 5.6-GHz radio over fiber signaling over 20-km WDM-PON. Error-free signal demodulation of 64-subcarrier 4-QAM signals modulated at 198.5-Mb/s is achieved after fiber and 2-m indoor wireless transmission....

  11. Bidirectional 120 Gbps SDM-WDM-PON with colourless ONU using 10 Gbps optical components without DSP

    DEFF Research Database (Denmark)

    Hu, Hao; Asif, Rameez; Ye, Feihong

    2016-01-01

    We demonstrate an SDM-WDM-PON system with symmetric aggregated capacity of 120 Gbps (3×scores, 4×wavelengths, 10 Gbps each). The light sources are distributed through the center core of the 7-core fiber, facilitating colorless ONU.......We demonstrate an SDM-WDM-PON system with symmetric aggregated capacity of 120 Gbps (3×scores, 4×wavelengths, 10 Gbps each). The light sources are distributed through the center core of the 7-core fiber, facilitating colorless ONU....

  12. Perspectives of Long-Haul WDM Transmission Systems Based on Phase-Insensitive Fiber-Optic Parametric Amplifiers

    DEFF Research Database (Denmark)

    Jazayerifar, M.; Sackey, I.; Elschner, R.

    2015-01-01

    The deployment of phase-insensitive fiber-opticparametric amplifiers (PI-FOPAs) as inline amplifiers in longhaul WDM transmission systems is discussed, and it is outlined how to design PI-FOPAs to be a valuable upgrade option for this application.......The deployment of phase-insensitive fiber-opticparametric amplifiers (PI-FOPAs) as inline amplifiers in longhaul WDM transmission systems is discussed, and it is outlined how to design PI-FOPAs to be a valuable upgrade option for this application....

  13. Experimental analysis of pilot-based equalization for probabilistically shaped WDM systems with 256QAM/1024QAM

    DEFF Research Database (Denmark)

    Yankov, Metodi Plamenov; Porto da Silva, Edson; Da Ros, Francesco

    2017-01-01

    Pilot based equalization is studied in a 5x10 Gbaud WDM transmission experiment. The equalization is independent of the modulation format and is demonstrated for 256/1024QAM with uniform and probabilistically optimized distribution using an optimized pilot insertion rate of 2-5%.......Pilot based equalization is studied in a 5x10 Gbaud WDM transmission experiment. The equalization is independent of the modulation format and is demonstrated for 256/1024QAM with uniform and probabilistically optimized distribution using an optimized pilot insertion rate of 2-5%....

  14. Solving the RWA Problem in WDM Optical Networks Using the BCO Meta-Heuristic

    Directory of Open Access Journals (Sweden)

    V. S. Aćimović-Raspopović

    2010-06-01

    Full Text Available This paper researches the routing and wavelength assignment (RWA problem in wavelength routed optical WDM networks with the wavelength conversion capability at different network nodes. We studied the static case in which all connection requests are known in advance, thus a routing decision can be made based on the complete knowledge of the traffic to be served by the network. The Bee Colony Optimization (BCO metaheuristic is applied to solve the RWA problem. We carried out a comprehensive simulation study of the performance of the proposed BCORWA algorithm for different network topologies and traffic scenarios. The obtained simulation results are analyzed and compared.

  15. Single channel and WDM transmission of 28 Gbaud zero-guard-interval CO-OFDM.

    Science.gov (United States)

    Zhuge, Qunbi; Morsy-Osman, Mohamed; Mousa-Pasandi, Mohammad E; Xu, Xian; Chagnon, Mathieu; El-Sahn, Ziad A; Chen, Chen; Plant, David V

    2012-12-10

    We report on the experimental demonstration of single channel 28 Gbaud QPSK and 16-QAM zero-guard-interval (ZGI) CO-OFDM transmission with only 1.34% overhead for OFDM processing. The achieved transmission distance is 5120 km for QPSK assuming a 7% forward error correction (FEC) overhead, and 1280 km for 16-QAM assuming a 20% FEC overhead. We also demonstrate the improved tolerance of ZGI CO-OFDM to residual inter-symbol interference compared to reduced-guard-interval (RGI) CO-OFDM. In addition, we report an 8-channel wavelength-division multiplexing (WDM) transmission of 28 Gbaud QPSK ZGI CO-OFDM signals over 4160 km.

  16. Cost and Availability Analysis of 2- and 3-Connected WDM Networks Physical Interconnection

    DEFF Research Database (Denmark)

    Gutierrez Lopez, Jose Manuel; Riaz, M. Tahir; Pedersen, Jens Myrup

    2012-01-01

    Our future in personal and professional lives is becoming more attached to the evolution of communication technologies and their applications. Consequently, the way Next Generation Network are currently being planned and deployed, might have a great impact on common people depending on how networks...... for the best trade-off among the relevant parameters for the network. In this paper we analyze this trade-off by studying 2-and 3-connected graphs to be used as WDM (Wavelength Division Multiplexing) networks physical infrastructure. The experiments show how the way links are distributed to interconnect...

  17. A Fibre Bragg Grating Interrogation Technique Based on High Birefringence Fibre Loop Mirror and WDM

    Directory of Open Access Journals (Sweden)

    Zhang Xun

    2016-01-01

    Full Text Available In this paper, a fibre Bragg grating (FBG interrogation technique based on high Birefringence fibre loop mirror (Hi-Bi FLM and wavelength division multiplexer (WDM is proposed and demonstrated. The approximate linear edge of the transmittance of the Hi-Bi FLM, which is a sinusoidal function of wavelength, is used to interrogate the sensing FBGs and WDMs is used to realize wavelength discrimination .Suitable for both static and dynamic sensing, this interrogation method has the advantages of all fibre design and high stability.

  18. Experimental Analysis and Reduction of FWM Using Optical Rectangle Filter for WDM

    Directory of Open Access Journals (Sweden)

    Ghulam Fizza

    2016-01-01

    Full Text Available Nonlinearities implanted by refractive index and scattering degrade the performance of optical networks. In this paper, FWM (Four Wave Mixing has been analyzed for four different channels with 10 nm spacing. Due to the presence of resonant frequency, FWM interface of different channels in WDM (Wavelength Division Multiplexing hinders the performance of the system. The system is affected by nonlinear cross talk. A system with the bandwidth of 10 Gbps has been investigated using External Modulation and an optical rectangle filter as a key parameter to improve the system performance with respect to FWM effect

  19. The Chromatin Protein DUET/MMD1 Controls Expression of the Meiotic Gene TDM1 during Male Meiosis in Arabidopsis.

    Science.gov (United States)

    Andreuzza, Sébastien; Nishal, Bindu; Singh, Aparna; Siddiqi, Imran

    2015-09-01

    Meiosis produces haploid cells essential for sexual reproduction. In yeast, entry into meiosis activates transcription factors which trigger a transcriptional cascade that results in sequential co-expression of early, middle and late meiotic genes. However, these factors are not conserved, and the factors and regulatory mechanisms that ensure proper meiotic gene expression in multicellular eukaryotes are poorly understood. Here, we report that DUET/MMD1, a PHD finger protein essential for Arabidopsis male meiosis, functions as a transcriptional regulator in plant meiosis. We find that DUET-PHD binds H3K4me2 in vitro, and show that this interaction is critical for function during meiosis. We also show that DUET is required for proper microtubule organization during meiosis II, independently of its function in meiosis I. Remarkably, DUET protein shows stage-specific expression, confined to diplotene. We identify two genes TDM1 and JAS with critical functions in cell cycle transitions and spindle organization in male meiosis, as DUET targets, with TDM1 being a direct target. Thus, DUET is required to regulate microtubule organization and cell cycle transitions during male meiosis, and functions as a direct transcription activator of the meiotic gene TDM1. Expression profiling showed reduced expression of a subset comprising about 12% of a known set of meiosis preferred genes in the duet mutant. Our results reveal the action of DUET as a transcriptional regulator during male meiosis in plants, and suggest that transcription of meiotic genes is under stagewise control in plants as in yeast.

  20. An Area-Efficient TDM NoC Supporting Reconfiguration for Mode Changes

    DEFF Research Database (Denmark)

    Sørensen, Rasmus Bo; Pezzarossa, Luca; Sparsø, Jens

    2016-01-01

    This paper presents an area-efficient time-division-multiplexing (TDM) network-on-chip (NoC) intended for use in a multicore platform for hard real-time systems. In such a platform, a mode change at the application level requires the tear-down and set-up of some virtual circuits without affecting...... the virtual circuits that persist across the mode change. Our NoC supports such reconfiguration in a very efficient way, using the same resources that are used for transmission of regular data. We evaluate the presented NoC in terms of worst-case reconfiguration time, hardware cost, and maximum operating...... frequency. The results show that the hardware cost for an FPGA implementation of our architecture is a factor of 2.2 to 3.9 times smaller than other NoCs with reconfiguration functionalities, and that the worst-case time for a reconfiguration is shorter or comparable to those NoCs....

  1. Research on Transmission Performance of Different Modulation Formats Based on Re-modulation WDM-PON

    Science.gov (United States)

    Li, Li; Feng, He

    2017-05-01

    Dispersion and nonlinear effects will increase the effect on the system when the optical information transmits in high speed and long distance. The new optical modulation technology can reduce the attenuation caused by transmission procedure. In this paper, OptiSystem and Matlab were combined to set a model by comparing the dispersion tolerance and nonlinear effect of different code modulation formats. After that, the better performance code of IRZ (Inverse Return-to-Zero) and DQPSK (Differential Quadrature Phase Shifted Keying) will be used to study their properties in 10Gbit/s re-modulation WDM-PON access model. The DQPSK was used in downlink, IRZ modulation was used in uplink adopts the IRZ modulation was used in 10 Gbit/s re-modulation WDM passive optical network access model uplink on the basis of the above method. A simulation analysis is also made between the different duty ratios of the DQPSK and IRZ. Compared with the NRZ type, the IRZ has a better anti-dispersion property, channel crosstalk suppression ability and higher spectrum efficiency although it costs 3 dB powers. At the same time, it simplifies the structure of the ONU on the premise of not increasing the power and the cost. So, it fits the large capacity requirements between user stations and the central office in the future.

  2. An agent-based QoS provisioning mechanism for WDM optical networks

    Science.gov (United States)

    Ouyang, Yong; Zeng, Qingji; Yue, Ling

    2004-04-01

    This paper addresses QoS provisioning mechanisms in the WDM optical networks. With the appearance of metropolitan optical network, a hierarchical metro and wide area optical network will be envisioned in the near future. This hierarchical optical transport network is often divided into optical domains by geography, administration and technology, which usually employ different QoS routing algorithms and policies. To provide end-to-end optical QoS is becoming a new challenge for the optical network design. In this paper, we first give an overview of issues on the QoS provisioning in data, control and management planes of the WDM optical network. And then three provisioning approaches are analyzed and compared. Finally, we propose an agent-based hybrid centralized/distributed QoS provisioning mechanism based on the concept of domain agent. This agent-based hybrid mechanism employs centralized approach in the domain and distributed approach between domains. It offers scalability and intra-domain optimal QoS routing. It also keeps independence and interoperability between domains.

  3. P-cycle-based protection design for IP over WDM networks

    Science.gov (United States)

    Zhang, Zhizhong; Zhang, Yunlin; Zeng, Qingji; Zhao, Zhengfu; Luo, Jiangtao; Cao, Junwen

    2004-04-01

    P-cycle based protection has been proved to be an effective way for WDM networks" survivability design. In IP over WDM networks, p-cycle can also be constructed through GMPLS technology to protect a number of IP links. In this paper, we demonstrate that there are some drawbacks associated with the current p-cycle searching algorithms, e.g., 1) none of the them take the hop-count constraint into account, which means some requests may not able to be protected by their associated p-cycles; 2) to protect those failures occurred on the straddling links, the algorithms demand the traffic to be split in half over each p-cycle segment, which may not be a resource efficient solution, and the routing procedure may be prohibited by hop-count constraints, also, it may introduce extra link propagation delays and causes IP packets to arrive out of order. We propose an improved object function, and give a novel p-cycle searching algorithm. Simulation results obtained from CERNET-like physical topology and the national backbone networks show that the developed algorithm performs well in terms of performance metrics such as the connection blocking probability and the success rate of the protection.

  4. An Optical Multicast Routing with Minimal Network Coding Operations in WDM Networks

    Directory of Open Access Journals (Sweden)

    Huanlin Liu

    2014-01-01

    Full Text Available Network coding can improve the optical multicast routing performance in terms of network throughput, bandwidth utilization, and traffic load balance. But network coding needs high encoding operations costs in all-optical WDM networks due to shortage of optical RAM. In the paper, the network coding operation is defined to evaluate the number of network coding operation cost in the paper. An optical multicast routing algorithm based on minimal number of network coding operations is proposed to improve the multicast capacity. Two heuristic criteria are designed to establish the multicast routing with low network coding cost and high multicast capacity. One is to select one path from the former K shortest paths with the least probability of dropping the multicast maximal capacity. The other is to select the path with lowest potential coding operations with the highest link shared degree among the multiple wavelength disjoint paths cluster from source to each destination. Comparing with the other multicast routing based on network coding, simulation results show that the proposed multicast routing algorithm can effectively reduce the times of network coding operations, can improve the probability of reaching multicast maximal capacity, and can keep the less multicast routing link cost for optical WDM networks.

  5. Transmission Performance Analysis of Fiber Optical Parametric Amplifiers for WDM System

    Directory of Open Access Journals (Sweden)

    Xiaohong Jiang

    2009-01-01

    Full Text Available A numerical analysis is presented on the long-haul wavelength-division multiplexing (WDM transmission system employing fiber-optic parametric amplifier (FOPA cascades based on one-pump FOPA model with Raman Effect taken into account. The end-to-end equalization scheme is applied to optimize the system features in terms of proper output powers and signal-to-noise ratios (SNRs in all the channels. The numerical results show that—through adjusting the fiber spans along with the number of FOPAs as well as the channel powers at the terminals in a prescribed way—the transmission distance and system performance can be optimized. By comparing the results generated by different lengths of fiber span, we come to the optimal span length to achieve the best transmission performance. Furthermore, we make a comparison among the long-haul WDM transmission systems employing different inline amplifiers, namely, FOPA, erbium-doped fiber amplifier (EDFA, and Fiber Raman Amplifier (FRA. FOPA demonstrates its advantage over the other two in terms of system features.

  6. THEORETICAL EVALUATION OF NONLINEAR EFFECTS ON OPTICAL WDM NETWORKS WITH VARIOUS FIBER TYPES

    Directory of Open Access Journals (Sweden)

    YASIN M. KARFAA

    2010-09-01

    Full Text Available A theoretical study is carried out to evaluate the performance of an opticalwavelength division multiplexing (WDM network transmission system in the presenceof crosstalk due to optical fiber nonlinearities. The most significant nonlinear effects inthe optical fiber which are Cross-Phase Modulation (XPM, Four-Wave Mixing (FWM,and Stimulated Raman Scattering (SRS are investigated. Four types of optical fiber areincluded in the analysis; these are: single-mode fiber (SMF, dispersion compensationfiber (DCF, non-zero dispersion fiber (NZDF, and non-zero dispersion shifted fiber(NZDSF. The results represent the standard deviation of nonlinearity induced crosstalknoise power due to FWM and SRS, XPM power penalty for SMF, DCF, NZDF, andNZDSF types of fiber, besides the Bit Error Rate (BER for the three nonlinear effectsusing standard fiber type (SMF. It is concluded that three significant fiber nonlinearitiesare making huge limitations against increasing the launched power which is desired,otherwise, lower values of launched power limit network expansion including length,distance, covered areas, and number of users accessing the WDM network, unlesssuitable precautions are taken to neutralize the nonlinear effects. Besides, various fibertypes are not behaving similarly towards network parameters.

  7. Constellation Shaping for WDM systems using 256QAM/1024QAM with Probabilistic Optimization

    CERN Document Server

    Yankov, Metodi P; da Silva, Edson P; Forchhammer, Søren; Larsen, Knud J; Oxenløwe, Leif K; Galili, Michael; Zibar, Darko

    2016-01-01

    In this paper, probabilistic shaping is numerically and experimentally investigated for increasing the transmission reach of wavelength division multiplexed (WDM) optical communication system employing quadrature amplitude modulation (QAM). An optimized probability mass function (PMF) of the QAM symbols is first found from a modified Blahut-Arimoto algorithm for the optical channel. A turbo coded bit interleaved coded modulation system is then applied, which relies on many-to-one labeling to achieve the desired PMF, thereby achieving shaping gain. Pilot symbols at rate at most 2% are used for synchronization and equalization, making it possible to receive input constellations as large as 1024QAM. The system is evaluated experimentally on a 10 GBaud, 5 channels WDM setup. The maximum system reach is increased w.r.t. standard 1024QAM by 20% at input data rate of 4.65 bits/symbol and up to 75% at 5.46 bits/symbol. It is shown that rate adaptation does not require changing of the modulation format. The performanc...

  8. Sampled fiber grating for WDM signal queuing with picosecond time interval

    Science.gov (United States)

    Zhao, Weiqian; Liu, Shuai; Qi, Haifeng; Peng, Gangding; Shen, Mingya

    2017-12-01

    A new sampled fiber grating scheme is investigated for WDM signal queuing in time domain. The queuing is aimed at achieving very short constant time intervals down to picoseconds (ps) for many wavelength channels by a single fiber device. Theory and modeling predict that a consistence of linear spectral profiles exists between reflectivity or transmission spectrum and time delay spectrum. A sampled fiber grating based on Gaussian beam writing is proposed to offer a large number of wavelength channels and time delays within an approximate linear profile. Results for simulating a Gaussian sampled fiber grating show that the time delay minima of 8 channels within a section of the spectral profile have an average time delay step of 2.83 ps and standard deviation of 7.4% from linearity. Fiber gratings were successfully written by Gaussian laser beam in fabrication. A Gaussian sampled fiber grating was measured for time delay spectrum of 4 wavelength channels. An average time delay step of 9.67 ps is obtained. Some issues and related analysis and discussion are given. Our preliminary experiment suggests that the sampled fiber grating scheme can achieve ps-time steps for WDM signal queuing such as high-resolution time delay lines.

  9. Testing FSO WDM communication system in simulation software optiwave OptiSystem in different atmospheric environments

    Science.gov (United States)

    Vanderka, Ales; Hajek, Lukas; Bednarek, Lukas; Latal, Jan; Vitasek, Jan; Hejduk, Stanislav; Vasinek, Vladimir

    2016-09-01

    In this article the author's team deals with using Wavelength Division Multiplexing (WDM) for Free Space Optical (FSO) Communications. In FSO communication occurs due to the influence of atmospheric effect (attenuation, and fluctuation of the received power signal, influence turbulence) and the WDM channel suffers from interchannel crosstalk. There is considered only the one direction. The behavior FSO link was tested for one or eight channels. Here we will be dealing with modulation schemes OOK (On-Off keying), QAM (Quadrature Amplitude Modulation) and Subcarrier Intensity Modulation (SIM) based on a BPSK (Binary Phase Shift Keying). Simulation software OptiSystem 14 was used for tasting. For simulation some parameters were set according to real FSO link such as the datarate 1.25 Gbps, link range 1.4 km. Simulated FSO link used wavelength of 1550 nm with 0.8 nm spacing. There is obtained the influence of crosstalk and modulation format for the BER, depending on the amount of turbulence in the propagation medium.

  10. Multipath Routing and Wavelength Assignment Technique in Optical WDM Mesh Networks

    Science.gov (United States)

    Kavitha, T.; Shiyamala, S.; Rajamani, V.

    2017-12-01

    A routing and wavelength assignment (RWA) technique for supporting multipath traffic in optical wavelength-division multiplexing (WDM) mesh network is proposed in this paper. The network can be preceded by accomplishing two processes: one is establishing connection node and the second one is identifying the multipath and assigning wavelength. The connection node is selected based on the load and current traffic-carrying capacity of that node. During wavelength allocation mechanism, cost function is considered as the major criterion. Based on the cost involved in every path, the wavelengths are selected such that wavelength with the minimum cost is allocated to that particular path. This technique efficiently allocates the wavelength to the selected multiple paths and the traffic is routed to the destination using multiple paths with wavelength allocation. For simulation, NS2 simulator is used by applying the optical WDM network simulator patch. The proposed multipath RWA technique is compared with the existing RWA technique. We achieved a throughput of 12,625 packets for ten numbers of wavelengths. But the existing approach achieved a throughput of 10,189 packets only for the same numbers of wavelengths. Channel utilization is more, and delay is less compared with the existing technique. Hence, the proposed method is very efficient, since the router effectively routes the traffic within the network.

  11. Transmission of OFDM wired-wireless quintuple-play services along WDM LR-PONs using centralized broadband impairment compensation.

    Science.gov (United States)

    Alves, Tiago M F; Morant, Maria; Cartaxo, Adolfo V T; Llorente, Roberto

    2012-06-18

    The simultaneous transmission of four orthogonal frequency-division multiplexing (OFDM)-based signals used to provide quintuple-play services along wavelength division multiplexing (WDM) long-reach passive optical networks (LR-PONs) is demonstrated experimentally. Particularly, the transmission performance of custom signal bearing Gigabit Ethernet data, Worldwide Interoperability for Microwave Access, Long Term Evolution and Ultra Wideband (sub-bands 2 and 3) signals is evaluated for different LR-PONs reaches, considering single-wavelength and WDM transmission, and using a centralized impairment compensation technique at the central office that is transparent to the services provided.It is shown that error vector magnitude-compliant levels are obtained for all the OFDM-based signals in WDM LR-PONs reaching 100 km and that negligible inter-channel crosstalk is obtained for a channel spacing of 100 GHz regardless the OFDM-based signal considered. The successful multi-format OFDM transmission along the 100 km-long WDM LR-PON is achieved in the absence of optical dispersion compensation or single sideband modulation, and it is enabled by the performance improvement provided by the centralized impairment compensation realized.

  12. 1.2 Tb/s Ultredense WDM Long Reach and Spectral Efficiency Access Link with Digital Detection

    DEFF Research Database (Denmark)

    Zhang, Xu; Arlunno, Valeria; Jensen, Jesper Bevensee

    2011-01-01

    We experimentally demonstrate an ultradense WDM system with sub-channel spacing at the baud rate, achieving 4.0 b/s/Hz spectral efficiency and aggregate capacity of 1.2 Tb/s data transmission over 80-km SMF, for long reach access networking....

  13. Root cause analysis and solution to the degradation of wavelength division multiplexing (WDM) couplers in high power fiber amplifier system.

    Science.gov (United States)

    Peng, Xiang; Kim, Kyungbum; Gu, Xinhua; Mielke, Michael; Jennings, Stephen; Rider, Andy; Fisher, Norman; Woodbridge, Toby; Dionne, Rene; Trepanier, Francois

    2013-08-26

    In the evaluation a fused biconical taper 1480/1580 nm WDM's ability to handle high power cascaded Raman laser throughput (>100 W) a significant degradation in performance was observed. A systematic root cause investigation was conducted and it is experimentally confirmed that the WDM degradation was caused by an interaction between the high power 1480 nm line, an out-of-band Stokes line, and the -OH content of the glass optical fiber. Slanted fiber Bragg grating (SFBG) was introduced to filter out the 1390 nm out-of-band Stokes line in an attempt to avoid this interaction. Ultimately a series of tests were conducted and it was confirmed that the addition of a 1390 nm SFBG in between a high power Raman laser and the high power WDM has successfully prevented the degradation which therefore allowed the continued high power operation of the WDM. NAVAIR Public Release SPR 2013-469 Distribution Statement A-"Approved for Public release; distribution is unlimited".

  14. Carrierless amplitude phase modulation of VCSEL with 4 bit/s/Hz spectral efficiency for use in WDM-PON

    DEFF Research Database (Denmark)

    Rodes Lopez, Roberto; Wieckowski, Marcin; Pham, Tien Thang

    2011-01-01

    We experimentally demonstrate successful performance of VCSEL-based WDM link supporting advanced 16-level carrierless amplitude/phase modulation up to 1.25 Gbps, over 26 km SSMF with spectral efficiency of 4 bit/s/Hz for application in high capacity PONs. © 2011 Optical Society of America....

  15. Carrierless amplitude phase modulation of VCSEL with 4 bit/s/Hz spectral efficiency for use in WDM-PON.

    Science.gov (United States)

    Rodes, Roberto; Wieckowski, Marcin; Pham, Thang Tien; Jensen, Jesper Bevensee; Turkiewicz, Jarek; Siuzdak, Jerzy; Monroy, Idelfonso Tafur

    2011-12-19

    We experimentally demonstrate successful performance of VCSEL-based WDM link supporting advanced 16-level carrierless amplitude/phase modulation up to 1.25 Gbps, over 26 km SSMF with spectral efficiency of 4 bit/s/Hz for application in high capacity PONs.

  16. Parametric Amplification, Wavelength Conversion, and Phase Conjugation of a 2.048-Tbit/s WDM PDM 16-QAM Signal

    DEFF Research Database (Denmark)

    Hu, Hao; Jopson, R. M.; Gnauck, A. H.

    2015-01-01

    We demonstrate polarization-independent parametric amplification of a 2.048-Tbit/s 8-WDM PDM 16-QAM signal and simultaneous wavelength conversion and phase conjugation in a highly nonlinear fiber. Two high-power continuous-wave pumps with orthogonal polarizations and counter-phase modulation...

  17. Highly Effective Crosstalk Mitigation Method Using Counter-Propagation in Semiconductor Optical Amplifier for Remodulation WDM-PONs

    Directory of Open Access Journals (Sweden)

    Quang Thai Pham

    2014-01-01

    Full Text Available Remodulation-induced crosstalk mitigation in WDM-PON using remodulation approach is presented in this paper. Utilizing all-optical signal processing, the proposed method has been able to significantly improve system performance in terms of bit error rate (BER and bit rate distance product. Moreover, the proposed method could be used for both baseband and modulated downstream electrical signals.

  18. An improved approximate network blocking probability model for all-optical WDM Networks with heterogeneous link capacities

    Science.gov (United States)

    Khan, Akhtar Nawaz

    2017-11-01

    Currently, analytical models are used to compute approximate blocking probabilities in opaque and all-optical WDM networks with the homogeneous link capacities. Existing analytical models can also be extended to opaque WDM networking with heterogeneous link capacities due to the wavelength conversion at each switch node. However, existing analytical models cannot be utilized for all-optical WDM networking with heterogeneous structure of link capacities due to the wavelength continuity constraint and unequal numbers of wavelength channels on different links. In this work, a mathematical model is extended for computing approximate network blocking probabilities in heterogeneous all-optical WDM networks in which the path blocking is dominated by the link along the path with fewer number of wavelength channels. A wavelength assignment scheme is also proposed for dynamic traffic, termed as last-fit-first wavelength assignment, in which a wavelength channel with maximum index is assigned first to a lightpath request. Due to heterogeneous structure of link capacities and the wavelength continuity constraint, the wavelength channels with maximum indexes are utilized for minimum hop routes. Similarly, the wavelength channels with minimum indexes are utilized for multi-hop routes between source and destination pairs. The proposed scheme has lower blocking probability values compared to the existing heuristic for wavelength assignments. Finally, numerical results are computed in different network scenarios which are approximately equal to values obtained from simulations. Since January 2016, he is serving as Head of Department and an Assistant Professor in the Department of Electrical Engineering at UET, Peshawar-Jalozai Campus, Pakistan. From May 2013 to June 2015, he served Department of Telecommunication Engineering as an Assistant Professor at UET, Peshawar-Mardan Campus, Pakistan. He also worked as an International Internship scholar in the Fukuda Laboratory, National

  19. Technology Maturation in Preparation for the Cryogenic Propellant Storage and Transfer (CPST) Technology Demonstration Mission (TDM)

    Science.gov (United States)

    Meyer, Michael L.; Doherty, Michael P.; Moder, Jeffrey P.

    2014-01-01

    In support of its goal to find an innovative path for human space exploration, NASA embarked on the Cryogenic Propellant Storage and Transfer (CPST) Project, a Technology Demonstration Mission (TDM) to test and validate key cryogenic capabilities and technologies required for future exploration elements, opening up the architecture for large in-space cryogenic propulsion stages and propellant depots. Recognizing that key Cryogenic Fluid Management (CFM) technologies anticipated for on-orbit (flight) demonstration would benefit from additional maturation to a readiness level appropriate for infusion into the design of the flight demonstration, the NASA Headquarters Space Technology Mission Directorate (STMD) authorized funding for a one-year technology maturation phase of the CPST project. The strategy, proposed by the CPST Project Manager, focused on maturation through modeling, concept studies, and ground tests of the storage and fluid transfer of CFM technology sub-elements and components that were lower than a Technology Readiness Level (TRL) of 5. A technology maturation plan (TMP) was subsequently approved which described: the CFM technologies selected for maturation, the ground testing approach to be used, quantified success criteria of the technologies, hardware and data deliverables, and a deliverable to provide an assessment of the technology readiness after completion of the test, study or modeling activity. The specific technologies selected were grouped into five major categories: thick multilayer insulation, tank applied active thermal control, cryogenic fluid transfer, propellant gauging, and analytical tool development. Based on the success of the technology maturation efforts, the CPST project was approved to proceed to flight system development.

  20. Optical phase conjugation for nonlinearity compensation in WDM PDM 16-QAM transmission over dispersion-compensated and dispersion-uncompensated links

    DEFF Research Database (Denmark)

    Da Ros, Francesco; Sackey, I.; Jazayerifar, M.

    2015-01-01

    Kerr nonlinearity compensation by optical phase conjugation is demonstrated in a WDM PDM 16-QAM system. Improved received signal quality is reported for both dispersion-compensated and dispersion-uncompensated transmission and a comparison with digital backpropagation is provided.......Kerr nonlinearity compensation by optical phase conjugation is demonstrated in a WDM PDM 16-QAM system. Improved received signal quality is reported for both dispersion-compensated and dispersion-uncompensated transmission and a comparison with digital backpropagation is provided....

  1. One-to-six WDM multicasting of DPSK signals based on dual-pump four-wave mixing in a silicon waveguide

    DEFF Research Database (Denmark)

    Pu, Minhao; Hu, Hao; Ji, Hua

    2011-01-01

    We present WDM multicasting based on dual-pump four-wave mixing in a 3-mm long dispersion engineered silicon waveguide. One-to-six phase-preserving WDM multicasting of 10-Gb/s differential phase-shiftkeying (DPSK) data is experimentally demonstrated with bit-error rate measurements. All the six...... multicast signals show error-free performance with power penalty less than 3.8 dB....

  2. Fiber nonlinearity compensation by repeated phase conjugation in 2.048-Tbit/s WDM transmission of PDM 16-QAM channels

    DEFF Research Database (Denmark)

    Hu, Hao; Jopson, R. M.; Gnauck, A. H.

    2016-01-01

    We demonstrate compensation of fiber nonlinearities using repeated optical phase conjugation (OPC) in a WDM system with eight 32-Gbaud PDM 16-QAM channels, showing improved performance over a single mid-span OPC and no OPC.......We demonstrate compensation of fiber nonlinearities using repeated optical phase conjugation (OPC) in a WDM system with eight 32-Gbaud PDM 16-QAM channels, showing improved performance over a single mid-span OPC and no OPC....

  3. All-optical equalization of power transients on four 40 Gbit/s WDM channels using a fiber-based device

    DEFF Research Database (Denmark)

    Kjær, Rasmus; Oxenløwe, Leif Katsuo; Palsdottir, Bera

    2008-01-01

    Simultaneous transient suppression of four transient-impaired 40 Gbit/s RZ-ASK WDM channels is demonstrated. Sensitivity improvements are in excess of 5 dB and transmission penalties are significantly reduced.......Simultaneous transient suppression of four transient-impaired 40 Gbit/s RZ-ASK WDM channels is demonstrated. Sensitivity improvements are in excess of 5 dB and transmission penalties are significantly reduced....

  4. Mathematical Verification for Transmission Performance of Centralized Lightwave WDM-RoF-PON with Quintuple Services Integrated in Each Wavelength Channel

    Directory of Open Access Journals (Sweden)

    Shuai Chen

    2015-01-01

    Full Text Available Wavelength-division-multiplexing passive-optical-network (WDM-PON has been recognized as a promising solution of the “last mile” access as well as multibroadband data services access for end users, and WDM-RoF-PON, which employs radio-over-fiber (RoF technique in WDM-PON, is even a more attractive approach for future broadband fiber and wireless access for its strong availability of centralized multiservices transmission operation and its transparency for bandwidth and signal modulation formats. As for multiservices development in WDM-RoF-PON, various system designs have been reported and verified via simulation or experiment till now, and the scheme with multiservices transmitted in each single wavelength channel is believed as the one that has the highest bandwidth efficiency; however, the corresponding mathematical verification is still hard to be found in state-of-the-art literature. In this paper, system design and data transmission performance of a quintuple services integrated WDM-RoF-PON which jointly employs carrier multiplexing and orthogonal modulation techniques, have been theoretically analyzed and verified in detail; moreover, the system design has been duplicated and verified experimentally and the theory system of such WDM-RoF-PON scheme has thus been formed.

  5. Single and Dual Physical Link Failures Stability Effect on Degree Three WDM Networks

    DEFF Research Database (Denmark)

    Gutierrez Lopez, Jose Manuel; Georgakilas, Konstantinos; Riaz, M. Tahir

    2010-01-01

    This paper studies the effects of Single and Dual physical link failures to the stability of WDM networks when deployed as regular 3-degree structures. The failure impact on the source-destination pair connections is evaluated for the different topology scenarios. In this way it is possible...... to provide an overview of the failure effects and their relation to network metrics such as availability or cost. The results quantify how much the different network interconnection designs are affected by Single and Dual Physical link failures. The case study treats a realistic scenario, the interconnection...... of the NSFNET topology nodes. The main conclusions show that, when networks are designed under the same conditions, there is a linear relation between average downtime and ratio of connections affected by failures. Moreover, the most expensive optimized topologies to deploy provide higher availability....

  6. Mitigation of time-varying distortions in Nyquist-WDM systems using machine learning

    Science.gov (United States)

    Granada Torres, Jhon J.; Varughese, Siddharth; Thomas, Varghese A.; Chiuchiarelli, Andrea; Ralph, Stephen E.; Cárdenas Soto, Ana M.; Guerrero González, Neil

    2017-11-01

    We propose a machine learning-based nonsymmetrical demodulation technique relying on clustering to mitigate time-varying distortions derived from several impairments such as IQ imbalance, bias drift, phase noise and interchannel interference. Experimental results show that those impairments cause centroid movements in the received constellations seen in time-windows of 10k symbols in controlled scenarios. In our demodulation technique, the k-means algorithm iteratively identifies the cluster centroids in the constellation of the received symbols in short time windows by means of the optimization of decision thresholds for a minimum BER. We experimentally verified the effectiveness of this computationally efficient technique in multicarrier 16QAM Nyquist-WDM systems over 270 km links. Our nonsymmetrical demodulation technique outperforms the conventional QAM demodulation technique, reducing the OSNR requirement up to ∼0.8 dB at a BER of 1 × 10-2 for signals affected by interchannel interference.

  7. Quality Analysis in Phase Modulated Radio over Fiber in WDM/DWDM Network

    Science.gov (United States)

    Sahoo, S.; Kiran, K. V.; Kumar, V.; Yadav, D.; Barpanda, N. K.; Das, Santos Kumar

    2017-05-01

    There has been increasing demand for connection setup with a higher quality of service (QoS) in WDM/DWDM networks, especially in fields like radio over fiber, where phase modulation affects the link quality. Hence to meet guaranteed QoS in a phase modulated link, the effects of phase modulation on link quality are very much needed. The link quality is termed as quality factor (Q-factor). The primary objective is to use effectively the connections available to optimize the computed number of connections and reduce the blocked connections but at the same time guaranteeing QoS as per client's need. The analysis has been done by taking care of routing and wavelength assignment (RWA) techniques. The performance analysis is presented in terms of blocking probability.

  8. Integration of FBG Strain Sensors in WDM Networks, Effects on Quality Factor

    Directory of Open Access Journals (Sweden)

    Ali Al-Lawati

    2009-06-01

    Full Text Available A study of the effect of integrating an FBG sensor in a four wavelength WDM communications system operating at 1550 nm is presented. The simulations considered focus on the mutual effects of both the sensing and the communications systems. The effect of power levels of the interrogating optical source on the performance of the two systems is also investigated under excitation levels of up to 10 dBm. The network layout used in the simulations is based on an actual optical link in Oman having a variety of spans. The results obtained at data rates of 2.5 and 10 Gbps with variable strains up to ±600 μs show a good tolerance in terms of quality of transmission for the two systems. However, the greater the strain values, the more noticeable are the degradations of transmission quality parameters of the communications system.

  9. Low-Complexity Tracking of Laser and Nonlinear Phase Noise in WDM Optical Fiber Systems

    DEFF Research Database (Denmark)

    Yankov, Metodi Plamenov; Fehenberger, Tobias; Barletta, Luca

    2015-01-01

    In this paper, the wavelength division multiplexed (WDM) fiber optic channel is considered. It is shown that for ideal distributed Raman amplification (IDRA), the Wiener process model is suitable for the non-linear phase noise due to cross phase modulation from neighboring channels. Based...... on this model, a phase noise tracking algorithm is presented. We approximate the distribution of the phase noise at each time instant by a mixture of Tikhonov distributions, and derive a closed form expression for the posterior probabilities of the input symbols. This reduces the complexity dramatically...... compared to previous trellis-based approaches, which require numerical integration. Further, the proposed method performs very well in low-to-moderate signal-to-noise ratio (SNR), where standard decision directed (DD) methods, especially for high-order modulation, fail. The proposed algorithm does not rely...

  10. MIMO-OFDM WDM PON with DM-VCSEL for femtocells application.

    Science.gov (United States)

    Othman, M B; Deng, Lei; Pang, Xiaodan; Caminos, J; Kozuch, W; Prince, K; Yu, Xianbin; Jensen, Jesper Bevensee; Monroy, I Tafur

    2011-12-12

    We report on experimental demonstration of 2x2 MIMO-OFDM 5.6-GHz radio over fiber signaling over 20 km WDM-PON with directly modulated (DM) VCSELs for femtocells application. MIMO-OFDM algorithms effectively compensate for impairments in the wireless link. Error-free signal demodulation of 64 subcarrier 4-QAM signals modulated at 198.5 Mb/s net data rate is achieved after fiber and 2 m indoor wireless transmission. We report BER of 7x10(-3) at the receiver for 16-QAM signals modulated at 397 Mb/s after 1 m of wireless transmission. Performance dependence on different wireless transmission path lengths, antenna separation, and number of subcarriers have been investigated. © 2011 Optical Society of America

  11. Restorability on 3-connected WDM Networks Under Single and Dual Physical Link Failures

    DEFF Research Database (Denmark)

    Gutierrez Lopez, Jose Manuel; Jensen, Michael; Riaz, Tahir

    2013-01-01

    This work studies the influence the network interconnection has over restoration techniques. The way physical links are distributed to interconnect network nodes has a great impact on parameters such as path distances when failures occur and restoration is applied. The work focuses on single...... and dual physical link failures restorability on WDM transport networks. This failure scenarios are tested over several 3-connected topologies, and studied in graph theory and network planning terms. In connection with the graphs, the resulting hop path distances and lengths are evaluated. In relation...... to network planning, the trade-off network length vs. performance of the different topological options is studied. The results show how 3-connected graphs could provide a reasonable trade-off between costs, link failure rates, and restored path parameters....

  12. Influence of Transmitting Pointing Errors on High Speed WDM-AMI-Is-OWC Transmission System

    Science.gov (United States)

    Shatnawi, Abdallah Ahmad; Bin Mohd Warip, Mohd Nazri; Safar, Anuar Mat

    2017-12-01

    Inter-satellite communication is one of the revolutionary techniques that can be used to transmit the high speed date between satellites. However, space turbulences such as transmitting pointing errors play a significant role while designing inter-satellite communication systems. Those turbulences cause shutdown of inter-satellite link due to increase of attenuation during data transmission through link. The present work aims to develop an integrated data transmission system incorporating alternate mark inversion (AMI), wavelength division multiplexing (WDM), and polarization interleaving (PI) scheme for transmitting data 160 Gbps over inter-satellite link of 1,000 km under the influence of space turbulences. The performance of the integrated data transmission of 160 Gbps data up to 1,000 km will be evaluated under the influence of space turbulences by means of signal to noise ratio (SNR), total received power, bit error rate and eye diagram.

  13. A large capacity time division multiplexed (TDM) laser beam combining technique enabled by nanosecond speed KTN deflector

    Science.gov (United States)

    Yin, Stuart (Shizhuo); Chao, Ju-Hung; Zhu, Wenbin; Chen, Chang-Jiang; Campbell, Adrian; Henry, Michael; Dubinskiy, Mark; Hoffman, Robert C.

    2017-08-01

    In this paper, we present a novel large capacity (a 1000+ channel) time division multiplexing (TDM) laser beam combining technique by harnessing a state-of-the-art nanosecond speed potassium tantalate niobate (KTN) electro-optic (EO) beam deflector as the time division multiplexer. The major advantages of TDM approach are: (1) large multiplexing capability (over 1000 channels), (2) high spatial beam quality (the combined beam has the same spatial profile as the individual beam), (3) high spectral beam quality (the combined beam has the same spectral width as the individual beam, and (4) insensitive to the phase fluctuation of individual laser because of the nature of the incoherent beam combining. The quantitative analyses show that it is possible to achieve over one hundred kW average power, single aperture, single transverse mode solid state and/or fiber laser by pursuing this innovative beam combining method, which represents a major technical advance in the field of high energy lasers. Such kind of 100+ kW average power diffraction limited beam quality lasers can play an important role in a variety of applications such as laser directed energy weapons (DEW) and large-capacity high-speed laser manufacturing, including cutting, welding, and printing.

  14. Development of Compact and Low-Crosstalk PLC-WDM Filters for Hybrid-Integrated Bidirectional Optical Transceivers

    Science.gov (United States)

    Kim, Kyoung-Youm; Kim, Se Yoon; Kim, Myoung Won; Jung, Suntae

    2005-05-01

    This paper reports on the development of planar-lightwave-circuit wavelength-division-multiplexing (PLC-WDM) filters based on double polynomial curve directional couplers, which will be integrated into compact and low-cost bidirectional optical transceivers for FTTx systems. Silica-based PLC-WDM filters smaller than 5 mm x 100 m for Ethernet passive optical network (E-PON) applications were designed and fabricated to have low bidirectional crosstalk (lower than -40 dB) as well as low insertion losses (lower than 1 dB) within the operating temperatures of -40 to 80 ° C. Several features and design guides that can reduce the size of directional couplers and improve the level of bidirectional crosstalk are discussed.

  15. Parametric amplification and wavelength conversion of a 2.048-Tbit/s WDM PDM 16-QAM signal

    DEFF Research Database (Denmark)

    Hu, Hao; Jopson, R. M.; Gnauck, A. H.

    2014-01-01

    We demonstrate polarisation-insensitive parametric amplification in highly nonlinear fibre of a 2.048-Tbit/s dense WDM PDM 16-QAM signal with ∼10 dB on-off gain and simultaneous wavelength conversion and phase conjugation, with mean Q2 penalties of only 0.6 dB and 0.4 dB.......We demonstrate polarisation-insensitive parametric amplification in highly nonlinear fibre of a 2.048-Tbit/s dense WDM PDM 16-QAM signal with ∼10 dB on-off gain and simultaneous wavelength conversion and phase conjugation, with mean Q2 penalties of only 0.6 dB and 0.4 dB....

  16. 2x2 MIMO-OFDM Gigabit fiber-wireless access system based on polarization division multiplexed WDM-PON

    DEFF Research Database (Denmark)

    Deng, Lei; Pang, Xiaodan; Zhao, Ying

    2012-01-01

    -based zero forcing (ZF) channel estimation algorithm is designed to compensate the polarization rotation and wireless multipath fading. A 797 Mb/s net data rate QPSK-OFDM signal with error free (OFDM signal with BER performance of 1.2 × 10......We propose a spectral efficient radio over wavelength division multiplexed passive optical network (WDM-PON) system by combining optical polarization division multiplexing (PDM) and wireless multiple input multiple output (MIMO) spatial multiplexing techniques. In our experiment, a training...

  17. Mitigation of Nonlinear Effects on WDM QAM Signals Enabled by Optical Phase Conjugation with Efficient Bandwidth Utilization

    OpenAIRE

    Yoshima, S.; Sun, Y.; Liu, Z.; Bottrill, K. R. H.; Parmigiani, F.; Richardson, D J; Petropoulos, P.

    2016-01-01

    We present nonlinear impairment mitigation of wavelength division multiplexed (WDM) signals, through optical phase conjugation (OPC). We conduct our experiments on a 400-km long installed fiber link equipped with erbium-doped fiber amplifiers (EDFAs), with the OPC placed close to the middle of the link. Our OPC configuration realizes efficient reuse of the signal bandwidth, avoiding the loss of half of the spectral band typical of most phase conjugating schemes. We demonstrate the operation o...

  18. 8×40 Gb/s 55-km WDM transmission over conventional fiber using a new RZ optical source

    OpenAIRE

    Yu, Jianjun; Zheng, Xueyan; Liu, Fenghai; Peucheret, Christophe; Jeppesen, Palle

    2000-01-01

    A multiwavelength RZ optical source with equal amplitudes and pulsewidths is successfully obtained by using wavelength conversion in a nonlinear optical loop mirror consisting of a common dispersion shifted fiber. The converted wavelengths of the eight signal pulses are in agreement with the ITU-T proposal and a commercial arrayed-waveguide grating is used for demultiplexing in the frequency-domain. By using the new source 8×40 Gb/s WDM transmission over 55 km conventional fiber was realized.

  19. 8×40 Gb/s 55-km WDM transmission over conventional fiber using a new RZ optical source

    DEFF Research Database (Denmark)

    Yu, Jianjun; Zheng, Xueyan; Liu, Fenghai

    2000-01-01

    A multiwavelength RZ optical source with equal amplitudes and pulsewidths is successfully obtained by using wavelength conversion in a nonlinear optical loop mirror consisting of a common dispersion shifted fiber. The converted wavelengths of the eight signal pulses are in agreement with the ITU-......-T proposal and a commercial arrayed-waveguide grating is used for demultiplexing in the frequency-domain. By using the new source 8×40 Gb/s WDM transmission over 55 km conventional fiber was realized....

  20. 10-m 9.51-Gb/s RGB laser diodes-based WDM underwater wireless optical communication.

    Science.gov (United States)

    Kong, Meiwei; Lv, Weichao; Ali, Tariq; Sarwar, Rohail; Yu, Chuying; Qiu, Yang; Qu, Fengzhong; Xu, Zhiwei; Han, Jun; Xu, Jing

    2017-08-21

    The availability of the underwater wireless optical communication (UWOC) based on red (R), green (G) and blue (B) lights makes the realization of the RGB wavelength division multiplexing (WDM) UWOC system possible. By properly mixing RGB lights to form white light, the WDM UWOC system has prominent potentiality for simultaneous underwater illumination and high-speed communication. In this work, for the first time, we experimentally demonstrate a 9.51-Gb/s WDM UWOC system using a red-emitting laser diode (LD), a single-mode pigtailed green-emitting LD and a multi-mode pigtailed blue-emitting LD. By employing 32-quadrature amplitude modulation (QAM) orthogonal frequency division multiplexing (OFDM) modulation in the demonstration, the red-light, the green-light and the blue-light LDs successfully transmit signals with the data rates of 4.17 Gb/s, 4.17 Gb/s and 1.17 Gb/s, respectively, over a 10-m underwater channel. The corresponding bit error rates (BERs) are 2.2 × 10-3, 2.0 × 10-3 and 2.3 × 10-3, respectively, which are below the forward error correction (FEC) threshold of 3.8 × 10-3.

  1. Meiotic Progression in Arabidopsis Is Governed by Complex Regulatory Interactions between SMG7, TDM1, and the Meiosis I–Specific Cyclin TAM[W][OA

    Science.gov (United States)

    Bulankova, Petra; Riehs-Kearnan, Nina; Nowack, Moritz K.; Schnittger, Arp; Riha, Karel

    2010-01-01

    Meiosis is a modified cell division that produces four haploid nuclei from a single diploid cell in two rounds of chromosome segregation. Here, we analyze the role of Arabidopsis thaliana SUPPRESSOR WITH MORPHOGENETIC EFFECTS ON GENITALIA7 (SMG7), THREE DIVISION MUTANT1 (TDM1), and TARDY ASYNCHRONOUS MEIOSIS (TAM) in meiotic progression. SMG7 is a conserved nonsense-mediated mRNA decay factor that is also, in Arabidopsis, essential for completion of meiosis. Examination of activating CYCLIN DEPENDENT KINASE A;1 phosophorylation at Thr-161 suggests that the meiotic arrest observed in smg7 mutants is likely caused by a failure to downregulate cyclin-dependent kinase (CDK) activity at the end of the second meiotic division. Genetic analysis indicates that SMG7 and TDM1 act in the same pathway to facilitate exit from meiosis. We further demonstrate that the cyclin TAM is specifically expressed in meiosis I and has both stimulatory and inhibitory effects on progression to meiosis II. TAM knockouts skip the second meiotic division producing unreduced gametes, but inactivation of SMG7 or TDM1 alleviates TAM’s requirement for entry into meiosis II. We propose a model that meiotic progression in Arabidopsis pollen mother cells is driven by a yet to be identified cyclin-CDK activity that is modulated by regulatory interactions between TDM1, SMG7, and TAM. PMID:21119056

  2. Heuristic approaches for energy-efficient shared restoration in WDM networks

    Science.gov (United States)

    Alilou, Shahab

    In recent years, there has been ongoing research on the design of energy-efficient Wavelength Division Multiplexing (WDM) networks. The explosive growth of Internet traffic has led to increased power consumption of network components. Network survivability has also been a relevant research topic, as it plays a crucial role in assuring continuity of service with no disruption, regardless of network component failure. Network survivability mechanisms tend to utilize considerable resources such as spare capacity in order to protect and restore information. This thesis investigates techniques for reducing energy demand and enhancing energy efficiency in the context of network survivability. We propose two novel heuristic energy-efficient shared protection approaches for WDM networks. These approaches intend to save energy by setting on sleep mode devices that are not being used while providing shared backup paths to satisfy network survivability. The first approach exploits properties of a math series in order to assign weight to the network links. It aims at reducing power consumption at the network indirectly by aggregating traffic on a set of nodes and links with high traffic load level. Routing traffic on links and nodes that are already under utilization makes it possible for the links and nodes with no load to be set on sleep mode. The second approach is intended to dynamically route traffic through nodes and links with high traffic load level. Similar to the first approach, this approach computes a pair of paths for every newly arrived demand. It computes these paths for every new demand by comparing the power consumption of nodes and links in the network before the demand arrives with their potential power consumption if they are chosen along the paths of this demand. Simulations of two different networks were used to compare the total network power consumption obtained using the proposed techniques against a standard shared-path restoration scheme. Shared

  3. Research of differentiated QoS routing in GMPLS-based IP/WDM networks

    Science.gov (United States)

    Wang, YiYun; Zeng, QingJi; Cao, JunWen

    2004-04-01

    At this point in technology's evolution, the simplicity, elegance, extensibility, and broad compatibility of the Internet protocol suite has made it the automatic choice for most forms of communication. The attempts at resolution of this apparent dichotomy consist of a collection of technologies and philosophies known as Quality of Service. In an IP network, QoS defines the ability to compensate for traffic characteristics without compromising average throughput. Clearly, optimizing QoS performance for all traffic types on an IP network presents a daunting challenge. To partially address this challenge, several Internet Engineering Task Force groups have been working on standardized approaches for IP-based QoS technologies. The IETF"s approaches fall into four categories: prioritization using differentiated services, reservation using integrated services, label switching using multi-protocol label switching, bandwidth management using the subnet bandwidth manager. Differentiated services classify per-hop behaviors on the basis of a Diffserv code point attached to the type of service byte in each packet"s IP header. This DSCP approach represents a form of soft QoS that rather coarsely classifies services through packet marking. The differentiated QoS routing in GMPLS-based IP/WDM Networks are a promising candidate for the next generation optical Internet networks. By using a unified control plane, such networks make more efficient usage of network resources both at the IP layer and the WDM optical layer. In this paper, we consider prioritized routing of bandwidth-guaranteed Label Switched paths (LSPs) providing service differentiation between classes of high and normal priority traffic. The QoS delay requirements are assumed to be translated into bandwidth and O-E-O conversion requirements. We present a graphical representation of the integrated network state which is different from other conventional graphical representations in that it models the cost of usage of

  4. Vaccination with liposomal leishmanial antigens adjuvanted with monophosphoryl lipid-trehalose dicorynomycolate (MPL-TDM) confers long-term protection against visceral leishmaniasis through a human administrable route.

    Science.gov (United States)

    Ravindran, Rajesh; Maji, Mithun; Ali, Nahid

    2012-01-01

    The development of a long-term protective subunit vaccine against visceral leishmaniasis depends on antigens and adjuvants that can induce an appropriate immune response. The immunization of leishmanial antigens alone shows limited efficacy in the absence of an appropriate adjuvant. Earlier we demonstrated sustained protection against Leishmania donovani with leishmanial antigens entrapped in cationic liposomes through an intraperitoneal route. However, this route is not applicable for human administration. Herein, we therefore evaluated the immune response and protection induced by liposomal soluble leishmanial antigen (SLA) formulated with monophosphoryl lipid-trehalose dicorynomycolate (MPL-TDM) through a subcutaneous route. Subcutaneous immunization of BALB/c mice with SLA entrapped in liposomes or with MPL-TDM elicited partial protection against experimental visceral leishmaniasis. In contrast, liposomal SLA adjuvanted with MPL-TDM induced significantly higher levels of protection in liver and spleen in BALB/c mice challenged 10 days post-vaccination. Protection conferred by this formulation was sustained up to 12 weeks of immunization, and infection was controlled for at least 4 months of the challenge, similar to liposomal SLA immunization administered intraperitoneally. An analysis of cellular immune responses of liposomal SLA + MPL-TDM immunized mice demonstrated the induction of IFN-γ and IgG2a antibody production not only 10 days or 12 weeks post-vaccination but also 4 months after the challenge infection and a down regulation of IL-4 production after infection. Moreover, long-term immunity elicited by this formulation was associated with IFN-γ production also by CD8⁺ T cells. Taken together, our results suggest that liposomal SLA + MPL-TDM represent a good vaccine formulation for the induction of durable protection against L. donovani through a human administrable route.

  5. Femoral chondrosarcoma discovered by SPECT-T.D.M. osseous scintigraphy; Chondrosarcome femoral decouvert par scintigraphie osseuse SPECT-TDM

    Energy Technology Data Exchange (ETDEWEB)

    Bourahla, K.; Nguyen, L.; Rolling, P.; Schott, A.; Di Salvo, R. [CLCC Paul-Strauss, Strasbourg, (France)

    2009-05-15

    Objectives: the SPECT/T.D.M. imaging can allow a quick diagnosis direction by the concomitant exploitation of scintigraphy data and morphological data brought by the T.D.M.. We present the case of a chondrosarcoma diagnosed in nuclear medicine thanks to the exploitation of the data supplied by the SPECT/T.D.M. that allowed to direct rapidly the later explorations while reducing the time of the patient coverage. Conclusions: A knowledge of the most characteristic morphological data allows to give some diagnosis at first sight during the scintigraphy explorations coupled SPECT/T.D.M. and this in the interest of the patient by reducing his coverage while including the nuclear doctor more broadly in some diagnosis approaches previously remote from his reach. (N.C.)

  6. Hybrid imaging (SPECT/CT, PET/CT) in differentiated thyroid cancer; Imagerie hybride (TEMP/TDM, TEP/TDM) et cancer differencie de la thyroide

    Energy Technology Data Exchange (ETDEWEB)

    Bardet, S.; Ciappuccini, R.; Aide, N. [Unite de concertation pluridisciplinaire thyroide, service de medecine nucleaire, centre Francois-Baclesse, 14 - Caen (France); Barraux, V. [Unite de radiophysique, centre Francois-Baclesse, 14 - Caen (France); Rame, J.P. [Chirurgie ORL, centre Francois-Baclesse, 14 - Caen (France)

    2010-08-15

    Differentiated thyroid cancer (DTC) is generally associated with a good prognosis. Local recurrences, mainly lymph-node involvement, account for 15-20% of cases and are surgically treated. Distant metastases, mostly in lungs and more rarely in bones, are present in 5% of patients. When iodine uptake is sufficient (in approximately 60% of patients), distant metastases can be destroyed by iterative activities of iodine 131. Serum thyroglobulin (Tg), which can be assessed either on hormonal treatment or on TSH stimulation is considered as the tumour marker in DTC. Functional (iodine 131 scintigraphy, FDG PET, bone scintigraphy) or anatomical (neck ultrasound, thoracic CT, bone MRI) imaging methods can be performed when Tg increases in order to show residual/recurrent disease. In recent years, new hybrid equipments integrating both a gamma camera and CT scan (SPECT/CT) have been commercialized while positron emission tomography cameras associated with CT (PET/CT) have been installed on the whole French territory. These equipments, which allow us to directly correlate functional and anatomical images, greatly improve the interpretation of planar scintigraphy or that of PET alone. Hybrid imaging enables us to precisely localize scintigraphic foci and most often, to immediately verify whether they correspond to tumour lesions. The aim of this article is to review the role of SPECT/CT and PET/CT in the management of patients with DTC in 2010. (authors)

  7. Provision of IR-UWB wireless and baseband wired services over a WDM-PON.

    Science.gov (United States)

    Pan, Shilong; Yao, Jianping

    2011-12-12

    A simple scheme to simultaneously generate an on-off keying or bi-phase modulation (BPM) impulse radio ultra wideband (IR-UWB) signal and a baseband wired signal in the optical domain using a dual-drive modulator is proposed and demonstrated. Although the two signals have spectral overlap in the optical spectrum, they are located at different frequency bands when converted to electrical signals at a photodetector (PD), which can be well separated by an electrical filter. An experiment is carried out. Eye diagrams, electrical spectra and BER measurements show that the co-channel interference between the UWB and the wired signals is small for a single-channel 36-km fiber link to provide 1.25-Gb/s UWB wireless and 1.25-Gb/s baseband wired services. The inter-channel interference is also small and negligible when the link is operated together with two other 1.25 Gb/s baseband wired links, which demonstrates that a conventional WDM-PON can be upgraded to provide additional UWB services without affecting the existing services by modifying the modulators in the center office and inserting UWB antennas in the optical network units. © 2011 Optical Society of America

  8. Novel iterative P-cycle configure model in WDM intelligent optical network

    Science.gov (United States)

    Li, Bin; Huang, Shanguo; Zhang, Yongjun; Gu, Wanyi; Zu, Yunxiao

    2009-11-01

    In this paper, a p-cycle generation algorithm is proposed that can protect service of static traffic model in WDM network. As the basic p-cycle sets calculated by algorithm such as the straddle link algorithm (SLA) always contain a straddle link in it. That is why the protection efficiency is higher than bidirectional line switch ring (BLSR). Any idle resource can be used for traffic restoration. But if the resource is not configured carefully then not all the resource of idle state can be utilized efficiently. Some extensions of algorithms are brought into effect to improve the protection capability. Based on these extensions, a novel iterative expanding p-cycle is introduced. A platform is constructed in OPNET modeler to verify the performance of this algorithm. Simulation results show that after several expansions for the basic p-cycle sets, the efficiency is improved. The pre-configured resource is deployed before any requests come. Comparison between different network topologies is studied. Finally, the results are analyzed and some directivity is given for further research.

  9. Optimization of WDM optical packet switches with sparse wavelength converters and nondegenerate fiber delay lines

    Science.gov (United States)

    Zhang, Zhizhong; Cheng, Fang; Yuan, Shufang; Zhao, Huandong; Zeng, Qingji; Wang, Jianxin

    2004-05-01

    In this paper, we investigate the somewhat untraditional approach of contention resolution in WDM optical packet switches. The most striking characteristics of the developed switch architecture are that (1) contention resolution is achieved by a combined sharing of fiber delay-lines (FDLs) and tunable optical wavelength converters (TOWCs); (2) FDLs used for contention resolution is in non-degenerate form, i.e., buffers are achieved by non-uniform distribution of the delay lines; (3) TOWCs just can achieve wavelength conversion in partial continuous wavelength channels, i.e., sparse wavelength conversion. We describe and analyze the concrete configuration of FDLs and TOWCs under non-bursty and bursty traffic scenarios. Simulation results demonstrate that for a prefixed packet loss probability constraint, e.g., 10-6, the developed architecture provides a different point of view in the optical packet switching (OPS) design. That is, combined sharing of FDLs and TOWCs can, effectively, obtain a good tradeoff between the switch size and the cost, and TOWCs which are achieved in sparse form can also decrease the implementing complexity.

  10. Improving performance of channel equalization in RSOA-based WDM-PON by QR decomposition.

    Science.gov (United States)

    Li, Xiang; Zhong, Wen-De; Alphones, Arokiaswami; Yu, Changyuan; Xu, Zhaowen

    2015-10-19

    In reflective semiconductor optical amplifier (RSOA)-based wavelength division multiplexed passive optical network (WDM-PON), the bit rate is limited by low modulation bandwidth of RSOAs. To overcome the limitation, we apply QR decomposition in channel equalizer (QR-CE) to achieve successive interference cancellation (SIC) for discrete Fourier transform spreading orthogonal frequency division multiplexing (DFT-S OFDM) signal. Using an RSOA with a 3-dB modulation bandwidth of only ~800 MHz, we experimentally demonstrate a 15.5-Gb/s over 20-km SSMF DFT-S OFDM transmission with QR-CE. The experimental results show that DFTS-OFDM with QR-CE attains much better BER performance than DFTS-OFDM and OFDM with conventional channel equalizers. The impacts of several parameters on QR-CE are investigated. It is found that 2 sub-bands in one OFDM symbol and 1 pilot in each sub-band are sufficient to achieve optimal performance and maintain the high spectral efficiency.

  11. Fiber nonlinearity mitigation of WDM-PDM QPSK/16-QAM signals using fiber-optic parametric amplifiers based multiple optical phase conjugations

    DEFF Research Database (Denmark)

    Hu, Hao; Jopson, Robert M.; Gnauck, Alan H.

    2017-01-01

    We demonstrate fiber nonlinearity mitigation by using multiple optical phase conjugations (OPCs) in the WDM transmission systems of both 8 x 32-Gbaud PDM QPSK channels and 8 x 32-Gbaud PDM 16-QAM channels, showing improved performance over a single mid-span OPC and no OPC in terms of nonlinear...... threshold and a best achievable Q(2) factor after transmission. In addition, after an even number of OPCs, the signal wavelength can be preserved after transmission. The performance of multiple OPCs for fiber nonlinearity mitigation was evaluated independently for WDM PDM QPSK signals and WDM PDM 16QAM...... to 1 dB compared to the case of mid-span OPC. The improvements in the best achievable Q(2) factors were more modest, ranging from 0.2 dB to 1.1 dB for the results presented. (C) 2017 Optical Society of America...

  12. Experimental Comparison of Gains in Achievable Information Rates from Probabilistic Shaping and Digital Backpropagation for DP-256QAM/1024QAM WDM Systems

    DEFF Research Database (Denmark)

    Porto da Silva, Edson; Yankov, Metodi Plamenov; Da Ros, Francesco

    2016-01-01

    Gains in achievable information rates from probabilistic shaping and digital backpropagation are compared for WDM transmission of 5 × 10 GBd DP-256QAM/1024QAM up to 1700 km of reach. The combination of both techniques its shown to provide gains of up to ∼0.5 bits/QAM symbol......Gains in achievable information rates from probabilistic shaping and digital backpropagation are compared for WDM transmission of 5 × 10 GBd DP-256QAM/1024QAM up to 1700 km of reach. The combination of both techniques its shown to provide gains of up to ∼0.5 bits/QAM symbol...

  13. Multi-channel WDM RZ-to-NRZ format conversion at 50 Gbit/s based on single silicon microring resonator

    DEFF Research Database (Denmark)

    Ding, Yunhong; Peucheret, Christophe; Pu, Minhao

    2010-01-01

    We comprehensively analyze multiple WDM channels RZ-to- NRZ format conversion using a single microring resonator. The scheme relies on simultaneous suppression of the first order harmonic components in the spectra of all the RZ channels. An optimized silicon microring resonator with free spectral...... range of 100 GHz and Q value of 7900 is designed and fabricated for this purpose. Multi-channel RZ-to-NRZ format conversion is demonstrated experimentally at 50 Gbit/s for WDM channels with 200 GHz channel spacing using the fabricated device. Bit error rate (BER)measurements show very good conversion...

  14. Experimental 2.5 Gbit/s QPSK WDM coherent phase modulated radio-over-fibre link with digital demodulation by a K-means algorithm

    DEFF Research Database (Denmark)

    Guerrero Gonzalez, Neil; Caballero Jambrina, Antonio; Amaya Fernández, Ferney Orlando

    2009-01-01

    Highest reported bit rate of 2.5 Gbit/s for optically phase modulated radio-over-fibre link employing coherent detection is demonstrated. Demodulation of 3·2.5 Gbit/s QPSK modulated WDM channels, is achieved after 79km of transmission through deployed fiber.......Highest reported bit rate of 2.5 Gbit/s for optically phase modulated radio-over-fibre link employing coherent detection is demonstrated. Demodulation of 3·2.5 Gbit/s QPSK modulated WDM channels, is achieved after 79km of transmission through deployed fiber....

  15. 4x10Gb/s WDM Bi-directional Gating in a Semiconductor Optical Amplifier by Using Polarization Multiplexing Technique

    DEFF Research Database (Denmark)

    Yu, Jianjun; Jeppesen, Palle

    2000-01-01

    Bi-directional SOA gating can further reduce the number of gating elements in the space switch, we demonstrate that a conventional SOA employing polarization multiplexing technique (PMT) can be used for bi-directional WDM gating operation at 10Gb/s.......Bi-directional SOA gating can further reduce the number of gating elements in the space switch, we demonstrate that a conventional SOA employing polarization multiplexing technique (PMT) can be used for bi-directional WDM gating operation at 10Gb/s....

  16. Kerr nonlinearity compensation in a 5×28-GBd PDM 16-QAM WDM system using fiber-based optical phase conjugation

    DEFF Research Database (Denmark)

    Da Ros, Francesco; Sackey, I.; Elschner, R.

    2014-01-01

    Effective Kerr nonlinearity mitigation is experimentally demonstrated using optical phase conjugation in the middle of an 800-km dispersion-compensated link for a 5-channel WDM 28-GBd PDM 16-QAM signal. A Q-factor improvement of 0.9 dB over no mitigation allows a BER......Effective Kerr nonlinearity mitigation is experimentally demonstrated using optical phase conjugation in the middle of an 800-km dispersion-compensated link for a 5-channel WDM 28-GBd PDM 16-QAM signal. A Q-factor improvement of 0.9 dB over no mitigation allows a BER...

  17. SOLUTION METHOD OF DYNAMIC ROUTING AND WAVE LENGTH ASSIGNMENT PROBLEM FOR WDM NETWORKS WITH TAKING INTO ACCOUNT FOUR-WAVE MIXING EFFECT

    Directory of Open Access Journals (Sweden)

    D. V. Ageyev

    2016-05-01

    Full Text Available The problem of dynamic route selection and wavelengths assignment in WDM networks is solved. This problem is important in WDM network management when requests are serviced for short-term connection installation and excess traffic is transferred. The proposed solution method is heuristic and is an improvement of the previously known method by taking into account the influence of four-wave mixing and using the new metric for finding the routes prospective for application. This makes it possible to reduce the probability of blocking calls during the connections at the average of 13% and the value of Q factor at 0.812.

  18. 10 Gb/s 1550 nm VCSEL transmission over 23.6 km SMF with no Dispersion Compensation and no Injection Locking for WDM PONs

    DEFF Research Database (Denmark)

    Gibbon, Timothy Braidwood; Prince, Kamau; Neumeyer, Christian

    2010-01-01

    demonstrate 10Gb/s VCSEL transmission for WDM PON over 23.6km single mode fiber. Dispersion penalty is limited to 2.9dB by introducing a wavelength offset with respect to the remote array waveguide grating to reduce chirp.......demonstrate 10Gb/s VCSEL transmission for WDM PON over 23.6km single mode fiber. Dispersion penalty is limited to 2.9dB by introducing a wavelength offset with respect to the remote array waveguide grating to reduce chirp....

  19. Quad 14Gbps L-Band VCSEL-based System for WDM Migration of 4-lanes 56 Gbps Optical Data Links

    DEFF Research Database (Denmark)

    Estaran Tolosa, Jose Manuel; Rodes Lopez, Roberto; Pham, Tien Thang

    2012-01-01

    We report on migrating multiple lane link into a single WDM L-band VCSEL-based system. Experimental validation successfully achieves 10 km of SMF reach with 4x14Gbps and less than 0.5dB inter-channel crosstalk penalty.......We report on migrating multiple lane link into a single WDM L-band VCSEL-based system. Experimental validation successfully achieves 10 km of SMF reach with 4x14Gbps and less than 0.5dB inter-channel crosstalk penalty....

  20. A New Wavelength Optimization and Energy-Saving Scheme Based on Network Coding in Software-Defined WDM-PON Networks

    Science.gov (United States)

    Ren, Danping; Wu, Shanshan; Zhang, Lijing

    2016-09-01

    In view of the characteristics of the global control and flexible monitor of software-defined networks (SDN), we proposes a new optical access network architecture dedicated to Wavelength Division Multiplexing-Passive Optical Network (WDM-PON) systems based on SDN. The network coding (NC) technology is also applied into this architecture to enhance the utilization of wavelength resource and reduce the costs of light source. Simulation results show that this scheme can optimize the throughput of the WDM-PON network, greatly reduce the system time delay and energy consumption.

  1. Non-Degenerate Four-Wave Mixing in a Silicon Nanowire and its Application for One-to-Six WDM Multicasting

    DEFF Research Database (Denmark)

    Pu, Minhao; Hu, Hao; Ji, Hua

    2011-01-01

    We present WDM multicasting based on non-degenerate four-wave mixing in a silicon nanowire. A one-to-six phase-preserving wavelength multicasting of 10 Gb/s differential phase-shift-keying data is experimentally demonstrated with bit-error rate measurements.......We present WDM multicasting based on non-degenerate four-wave mixing in a silicon nanowire. A one-to-six phase-preserving wavelength multicasting of 10 Gb/s differential phase-shift-keying data is experimentally demonstrated with bit-error rate measurements....

  2. Optimal Golomb Ruler Sequences Generation for Optical WDM Systems: A Novel Parallel Hybrid Multi-objective Bat Algorithm

    Science.gov (United States)

    Bansal, Shonak; Singh, Arun Kumar; Gupta, Neena

    2017-02-01

    In real-life, multi-objective engineering design problems are very tough and time consuming optimization problems due to their high degree of nonlinearities, complexities and inhomogeneity. Nature-inspired based multi-objective optimization algorithms are now becoming popular for solving multi-objective engineering design problems. This paper proposes original multi-objective Bat algorithm (MOBA) and its extended form, namely, novel parallel hybrid multi-objective Bat algorithm (PHMOBA) to generate shortest length Golomb ruler called optimal Golomb ruler (OGR) sequences at a reasonable computation time. The OGRs found their application in optical wavelength division multiplexing (WDM) systems as channel-allocation algorithm to reduce the four-wave mixing (FWM) crosstalk. The performances of both the proposed algorithms to generate OGRs as optical WDM channel-allocation is compared with other existing classical computing and nature-inspired algorithms, including extended quadratic congruence (EQC), search algorithm (SA), genetic algorithms (GAs), biogeography based optimization (BBO) and big bang-big crunch (BB-BC) optimization algorithms. Simulations conclude that the proposed parallel hybrid multi-objective Bat algorithm works efficiently as compared to original multi-objective Bat algorithm and other existing algorithms to generate OGRs for optical WDM systems. The algorithm PHMOBA to generate OGRs, has higher convergence and success rate than original MOBA. The efficiency improvement of proposed PHMOBA to generate OGRs up to 20-marks, in terms of ruler length and total optical channel bandwidth (TBW) is 100 %, whereas for original MOBA is 85 %. Finally the implications for further research are also discussed.

  3. Comparison of the left ventricular function measured by SPECT, PET and computed tomography among the coronary patient; Comparaison de la fonction ventriculaire gauche mesuree par TEMP, TEP et TDM chez le patient coronarien

    Energy Technology Data Exchange (ETDEWEB)

    Fleury, E.; Imperiano, H.; Cabral, D.; Da Silva, J.; Seiler, J. [Radiologie medicale, haute ecole de Sante, Geneve (HEdS), (Switzerland); Nkoulou, R. [cardiologie, hopitaux universitaires, Geneve (HUG), (Switzerland); Wissmeyer, M.; Seimbille, Y.; Schindler, T.; Ratib, O. [medecine nucleaire, hopitaux universitaires, Geneve (HUG), (Switzerland)

    2009-05-15

    The comparable results of the left ventricle extraction fraction (L.V.E.F.) got by PET and T.D.M. confirm that the L.V.E.F. calculated by synchronized PET can be surely employed for the patients having a dysfunction of the left ventricle. However, we observed a systematic overestimation of left ventricle volume by T.D.M. in comparison with the SPECT and PET due to the differences of automatic segmentation techniques. (N.C.)

  4. Application of a PK-PD Modeling and Simulation-Based Strategy for Clinical Translation of Antibody-Drug Conjugates: a Case Study with Trastuzumab Emtansine (T-DM1).

    Science.gov (United States)

    Singh, Aman P; Shah, Dhaval K

    2017-07-01

    Successful clinical translation of antibody-drug conjugates (ADCs) can be challenging due to complex pharmacokinetics and differences between preclinical and clinical tumors. To facilitate this translation, we have developed a general pharmacokinetic-pharmacodynamic (PK-PD) modeling and simulation (M&S)-based strategy for ADCs. Here we present the validation of this strategy using T-DM1 as a case study. A previously developed preclinical tumor disposition model for T-DM1 (Singh and Shah, AAPSJ. 2015; 18(4):861-875) was used to develop a PK-PD model that can characterize in vivo efficacy of T-DM1 in preclinical tumor models. The preclinical data was used to estimate the efficacy parameters for T-DM1. Human PK of T-DM1 was a priori predicted using allometric scaling of monkey PK parameters. The predicted human PK, preclinically estimated efficacy parameters, and clinically observed volume and growth parameters for breast cancer were combined to develop a translated clinical PK-PD model for T-DM1. Clinical trial simulations were performed using the translated PK-PD model to predict progression-free survival (PFS) and objective response rates (ORRs) for T-DM1. The model simulated PFS rates for HER2 1+ and 3+ populations were comparable to the rates observed in three different clinical trials. The model predicted only a modest improvement in ORR with an increase in clinically approved dose of T-DM1. However, the model suggested that a fractionated dosing regimen (e.g., front loading) may provide an improvement in the efficacy. In general, the PK-PD M&S-based strategy presented here is capable of a priori predicting the clinical efficacy of ADCs, and this strategy has been now retrospectively validated for all clinically approved ADCs.

  5. WDM Optical Access Network for Full-Duplex and Reconfigurable Capacity Assignment Based on PolMUX Technique

    Directory of Open Access Journals (Sweden)

    Jose Mora

    2014-12-01

    Full Text Available We present a novel bidirectional WDM-based optical access network featuring reconfigurable capacity assignment. The architecture relies on the PolMUX technique allowing a compact, flexible, and bandwidth-efficient router in addition to source-free ONUs and color-less ONUs for cost/complexity minimization. Moreover, the centralized architecture contemplates remote management and control of polarization. High-quality transmission of digital signals is demonstrated through different routing scenarios where all channels are dynamically assigned in both downlink and uplink directions.

  6. Tilted fibre Bragg grating based 800nm WDM interrogation system for strain, temperature and refractive index sensing

    OpenAIRE

    Suo, Rui; Chen, Xianfeng F.; Zhou, Kaiming; Zhang, Lin; Bennion, Ian; Liu, Bo

    2008-01-01

    We report the implementation of a low-cost high-resolution WDM interrogation system operating around 800nm region with bandwidth up to 60 nm and resolution of 13 pm by utilising a tilted fibre Bragg grating as an out-coupling device and a CCD-array detector. The system has been evaluated for interrogating fibre Bragg grating based strain, temperature sensors, giving sensitivities of 0.6 pm/µe and 5.6 pm/°C which are in good agreement with previously reported values. Furthermore, the system ha...

  7. Rede convergente IP com tecnologia WDM e SDH utilizando cabos OPGW em linhas de transmissão de energia

    OpenAIRE

    Silva, Rosemberg Lobato

    2011-01-01

    Esse trabalho trata de uma contribuição para o desenvolvimento de Redes Convergentes com tecnologia WDM e SDH utilizando cabos OPGW em linhas de transmissão de energia. O objetivo desse estudo é mostrar um caso ímpar no cenário nacional de uma rede convergente gerenciada por uma Empresa do setor elétrico; bem como essa Empresa justificou a migração de vários serviços e as vantagens e desvantagens. Neste trabalho é mostrado também uma ferramenta de calculo de enlace desenvolvida para o planeja...

  8. Constraining the Nature of Dark Matter with the Star-formation History of the Faintest Local Group Dwarf Galaxy Satellites

    Energy Technology Data Exchange (ETDEWEB)

    Chau, Alice; Mayer, Lucio [Center for Theoretical Astrophysics and Cosmology, Institute for Computational Science, University of Zurich, Winterthurerstrasse 190, CH-8057 Zürich (Switzerland); Governato, Fabio [Astronomy Department, University of Washington, Box 351580, Seattle, WA 98195-1580 (United States)

    2017-08-10

    Λ warm dark matter (ΛWDM), realized by collisionless particles of 1–3 keV, has been proposed as an alternative scenario to Λ-Cold-Dark Matter (ΛCDM) for the dwarf galaxy scale discrepancies. We present an approach to test the viability of such WDM models using star-formation histories (SFHs) of the dwarf spheroidal galaxies (dSphs) in the Local Group. We compare their high-time-resolution SFHs with the collapse redshift of their dark halos in CDM and WDM. Collapse redshift is inferred after determining the subhalo infall mass. This is based on the dwarf current mass inferred from stellar kinematics, combined with cosmological simulation results on subhalo evolution. WDM subhalos close to the filtering mass scale, forming significantly later than CDM, are the most difficult to reconcile with early truncation of star formation ( z ≥ 3). The ultra-faint dwarfs (UFDs) provide the most stringent constraints. Using six UFDs and eight classical dSphs, we show that a 1 keV particle is strongly disfavored, consistently with other reported methods. Excluding other models is only hinted for a few UFDs. Other UFDs for which the lack of robust constraints on halo mass prevents us from carrying out our analysis rigorously, show a very early onset of star formation that will strengthen the constraints delivered by our method in the future. We discuss the various caveats, notably the low number of dwarfs with accurately determined SFHs and the uncertainties when determining the subhalo infall mass, most notably the baryonic physics. Our preliminary analysis may serve as a pathfinder for future investigations that will combine accurate SFHs for local dwarfs with direct analysis of WDM simulations with baryons.

  9. Efficacy and safety of trastuzumab emtansine (T-DM1) in the treatment of HER2-positive metastatic breast cancer (MBC): a meta-analysis of randomized controlled trial.

    Science.gov (United States)

    Yan, Hongjing; Yu, Kewei; Zhang, Kaile; Liu, Linxia; Li, Yue

    2017-11-24

    Trastuzumab emtansine (T-DM1), an antibody-drug conjugate against human epidermal growth factor receptor 2 (HER2), has been used in the treatment of patients with HER2-positive metastatic breast cancer (MBC). We conducted a meta-analysis to evaluate the efficacy and toxicity of T-DM1 for the treatment of patients with HER2-positive MBC. Randomized controlled trials (RCTs), published in Pubmed, Embase, and Web of Science were systematically reviewed to assess the survival benefits and toxicity profile of HER2-positive patients with MBC who were treated with T-DM1. Outcomes included progression-free survival (PFS), overall survival (OS), overall response rate (ORR), and toxicities. Results were expressed as the hazard ratio (HR) with 95% confidence intervals (CIs). A total of 5 RCTs involving 3,720 patients met the inclusion criteria and were included in this meta-analysis. T-DM1 significantly prolonged PFS (HR = 0.73, 95% CI: 0.61, 0.86; P HER2 therapies. Based on the current evidence, T-DM1 significantly prolonged PFS and OS with a tolerated toxicity than other anti-HER2 therapies in patients with HER2-positive MBC. These findings confirm the use of T-DM1 for the treatment of patients with HER2-positive MBC. Further well-designed, multi-center RCTs needed to identify these findings.

  10. Efavirenz-therapy in HIV-patients with underlying liver disease: importance of continuous TDM of EFV.

    Science.gov (United States)

    Katsounas, A; Frank, A; Klinker, H; Langmann, P

    2007-08-16

    Many HIV-patients have a chronic liver disease due to HBV-/HCV-coinfections and/or consume of alcohol. In these patients therapy with EFV is often problematic because of NNRTI associated liver toxicity. Measurement of EFV plasmalevels and dose adjustment using TDM should be evaluated in this study. EFV-plasmasamples were standardized drawn 12h after ingestion. Measurement of 576 EFV plasmalevels was performed by HPLC. EFV plasmalevels as well as ALT-, AST- and GGT-values of 64 patients treated with EFV (5206 weeks) were measured regularly. 16 patients had a HCV-coinfection, 3 had a HBV-coinfection and 5 had an concomitant alcoholic liver disease. Maximal changes of ALT-, AST- and GGT-values (DeltaALT, DeltaAST, DeltaGGT), CD4-/CD8 cells and HIV-RNA were registered during therapy. Dose adjustment was performed for EFV plasmalevels out of target range 1000-4000 ng/ml. EFV plasmalevels of 40 HIV-patients (2288 +/- 1199 ng/ml) showed no significant differences compared to plasmalevels of HIV/HCV-patients (2391 +/- 976 ng/ml) or to plasmalevels of HIV/HBV-patients (1913 +/- 288 ng/ml) or to those of HIV-patients with alcoholic liver disease (1702 +/- 506 ng/ml). In 24 HIV-patients with underlying liver disease median DeltaGGT was +25 IU/l, median DALT was +13 IU/l and median DeltaAST was +8 IU/l. Dose adjustment was performed in 1 patient during study period. Increasing rates of ALT-, AST- and GGT-values showed no significant differences between liver healthy HIV-patients and those with a liver disease. 44 patients with continuous EFV plasmalevels in target range reached a viral suppression EFV-plasmalevels of HIV-infected patients showed no significant differences compared to EFV-plasmalevels of coinfected patients with concomitant liver disease. In those patients DeltaALT, DeltaAST and DeltaGGT were not significantly different than in liver-healthy HIV-patients with normal EFV-plasmaconcentrations. EFV plasmalevels in target range of 1000-4000 ng/ml correlate to a

  11. Cryogenic Propellant Storage and Transfer (CPST) Technology Maturation: Establishing a Foundation for a Technology Demonstration Mission (TDM)

    Science.gov (United States)

    Doherty, Michael P.; Meyer, Michael L.; Motil, Susan M.; Ginty, Carol A.

    2014-01-01

    As part of U.S. National Space Policy, NASA is seeking an innovative path for human space exploration, which strengthens the capability to extend human and robotic presence throughout the solar system. NASA is laying the groundwork to enable humans to safely reach multiple potential destinations, including asteroids, Lagrange points, the Moon and Mars. In support of this, NASA is embarking on the Technology Demonstration Mission Cryogenic Propellant Storage and Transfer (TDM CPST) Project to test and validate key cryogenic capabilities and technologies required for future exploration elements, opening up the architecture for large cryogenic propulsion stages (CPS) and propellant depots. The TDM CPST project will provide an on-orbit demonstration of the capability to store, transfer, and measure cryogenic propellants for a duration which is relevant to enable long term human space exploration missions beyond low Earth orbit (LEO). Recognizing that key cryogenic fluid management technologies anticipated for on-orbit (flight) demonstration needed to be matured to a readiness level appropriate for infusion into the design of the flight demonstration, the NASA Headquarters Space Technology Mission Directorate authorized funding for a one-year (FY12) ground based technology maturation program. The strategy, proposed by the CPST Project Manager, focused on maturation through modeling, studies, and ground tests of the storage and fluid transfer Cryogenic Fluid Management (CFM) technology sub-elements and components that were not already at a Technology Readiness Level (TRL) of 5. A technology maturation plan (TMP) was subsequently approved which described: the CFM technologies selected for maturation, the ground testing approach to be used, quantified success criteria of the technologies, hardware and data deliverables, and a deliverable to provide an assessment of the technology readiness after completion of the test, study or modeling activity. This paper will present

  12. A new design of WDM-based optical inter-satellite links in modern small satellite constellations

    Science.gov (United States)

    Yu, Zhihua; Luo, Fengguang; Zong, Liangjia; Tao, Qing

    2008-12-01

    Through the detail analysis of inter-satellites links in modern small satellite constellations, a new optical filters-based four-channel wavelength division multiplexer was designed and fabricated. This WDM device working at 0.85, 1.06, 1.31 and 1.55μm is designed to build an optical inter-satellites link, which provide two data streams at 0.85 and 1.55μm, an inter-satellite tracking channel at 1.06μm, and an different orbit communication channel at 1.31μm. Through experiments, we got the channel download efficiencies at 0.85, 1.06, 1.31 and 1.55μm are 49.7%, 42.3%, 33.4% and 25.1% and the channel interval is 5mm. The features of small size and light weight make this WDM device quite attractive for space borne applications and the big channel interval could also accommodate the wavelength shifts due to Doppler Effect, temperature variations and radiation effects in space.

  13. Simulation and Comparison of Advanced Modulation Formats for Wavelength Reuse in High-SpeedWDM-PON System

    Energy Technology Data Exchange (ETDEWEB)

    Han Chenyang; Hong Wei, E-mail: younghan@live.cn [Room B209, Wuhan National Lab.for Optoelectronics, Huazhong University of Science and Technology, Loyu Road 1037, Wuhan, Hubei Province (China)

    2011-02-01

    In recent years, the innovation in devices and schemes of physical layer plays an important role in promoting the development of WDM-PON (Wavelength Division MultiplexingPassive Optical Network). Among the key technologies adopted in the WDM-PON system, advanced modulation formats at downstream and remodulations at upstream attract the most attention. DPSK (Differential Phase Shift Keying Modulation), FSK(Frequency-Shift Keying), IRZ(Inverted Return-to-Zero) and Manchester are four of the most common formats and each of them was studied before, but, however, nobody compared and analyzed them together.So, we will do the job by numeralsimulation in this paper. During our simulation, the 40-Gbit/s FSK is generated through the demodulation of two DPSK signals and 40-Gbit/s Manchester signal bases of employing a delay interferometer (DI) and an optical delay line as format conversion device to convert RZ-DPSK(Return to Zero-Differential Phase Shift Keying Modulation) coding to Manchester coding, both of the two format generation schemes are novel.Meanwhile,this paper emphasizes the input optical power and dispersion tolerance, which both related to the sensitivity of the system. Analyze the sensitivity with DPSK, FSK, IRZ and Manchester, and then compare the four advanced modulation formats.

  14. Practical 12.5-Gb/s, 12.5-GHz spaced ultra-dense WDM PON.

    Science.gov (United States)

    Shim, H K; Kim, Hoon; Chung, Y C

    2014-11-17

    We report a practical 12.5-Gb/s, 12.5-GHz-spaced ultra-dense wavelength-division-multiplexed passive optical network (UD-WDM PON). For the cost-effectiveness, we implement the downstream links by using electro-absorption modulated lasers (EMLs) in the 4-level pulse amplitude modulation (4PAM) format and PIN receivers, and the upstream links by using reflective semiconductor optical amplifiers (RSOAs) modulated in the quadrature phase-shift-keying (QPSK) format and low-cost self-homodyne receivers. To further enhance its cost-effectiveness, we also utilize an optical frequency comb generator, instead of a large number of wavelength-selected lasers, to provide the seed light for these colorless RSOAs. We optimize the operating conditions of the EMLs and RSOAs to maximize the power margins in the presence of the crosstalk arising from closely spaced neighboring channels and the inter-symbol interference (ISI) caused by the narrow passband of the cascaded arrayed-waveguide gratings (AWGs) as well as the limited modulation bandwidths of RSOAs. The experimental results show that we can secure the power margins of >2.5 dB for both upstream and downstream links of the proposed UD-WDM PON.

  15. DS-8201a, a new HER2-targeting antibody-drug conjugate incorporating a novel DNA topoisomerase I inhibitor, overcomes HER2-positive gastric cancer T-DM1 resistance.

    Science.gov (United States)

    Takegawa, Naoki; Nonagase, Yoshikane; Yonesaka, Kimio; Sakai, Kazuko; Maenishi, Osamu; Ogitani, Yusuke; Tamura, Takao; Nishio, Kazuto; Nakagawa, Kazuhiko; Tsurutani, Junji

    2017-10-15

    Anti-HER2 therapies are beneficial for patients with HER2-positive breast or gastric cancer. T-DM1 is a HER2-targeting antibody-drug conjugate (ADC) comprising the antibody trastuzumab, a linker, and the tubulin inhibitor DM1. Although effective in treating advanced breast cancer, all patients eventually develop T-DM1 resistance. DS-8201a is a new ADC incorporating an anti-HER2 antibody, a newly developed, enzymatically cleavable peptide linker, and a novel, potent, exatecan-derivative topoisomerase I inhibitor (DXd). DS-8201a has a drug-to-antibody-ratio (DAR) of 8, which is higher than that of T-DM1 (3.5). Owing to these unique characteristics and unlike T-DM1, DS-8201a is effective against cancers with low-HER2 expression. In the present work, T-DM1-resistant cells (N87-TDMR), established using the HER2-positive gastric cancer line NCI-N87 and continuous T-DM1 exposure, were shown to be susceptible to DS-8201a. The ATP-binding cassette (ABC) transporters ABCC2 and ABCG2 were upregulated in N87-TDMR cells, but HER2 overexpression was retained. Furthermore, inhibition of ABCC2 and ABCG2 by MK571 restored T-DM1 sensitivity. Therefore, resistance to T-DM1 is caused by efflux of its payload DM1, due to aberrant expression of ABC transporters. In contrast to DM1, DXd payload of DS-8201a inhibited the growth of N87-TDMR cells in vitro. This suggests that either DXd may be a poor substrate of ABCC2 and ABCG2 in comparison to DM1, or the high DAR of DS-8201a relative to T-DM1 compensates for increased efflux. Notably, N87-TDMR xenograft tumor growth was prevented by DS-8201a. In conclusion, the efficacy of DS-8201a as a treatment for patients with T-DM1-resistant breast or gastric cancer merits investigation. © 2017 UICC.

  16. On the influence of optical accuracy of the band-pass thin-film filter design for coexistence-type colorless WDM-PON

    Science.gov (United States)

    Korček, Dušan; Müllerová, Jarmila

    2010-12-01

    The future coexistence of Gigabit-capable passive optical networks (GPON) and wavelength division multiplexing PON (WDM-PON) requires the wavelength band separation of optical signals for GPON downstream (1480 - 1500 nm) and WDM-PON (1500 - 1620 nm). A new multi-layer thin-film structure of the band separation filter is proposed and numerically investigated to separate these spectral bands at the wavelength of 1500 nm with the spectral transmittance edge as steep as possible and at least of 32 dB insertion loss at 1500 nm. This article is focused on modeling transmission characteristics of the design of a GPON and WDM-PON band separation thin-film filter with the aim of detecting the impact of optical properties of materials involved, namely the number of the designed layers and material dispersion. Additionally, we report on the investigation of the influence of layer thickness deviations on the transmission characteristics of the band-pass filter aimed for separating GPON and WDM-PON wavelength regions.

  17. Quad 14 Gbps L-band VCSEL-based system for WDM migration of 4-lanes 56 Gbps optical data links

    DEFF Research Database (Denmark)

    Estaran Tolosa, Jose Manuel; Rodes Lopez, Roberto; Pham, Tien Thang

    2012-01-01

    We report on migrating multiple-lane link into an L-band VCSEL-based WDM system. Experimental validation achieves successful transmission over 10 km of SMF at 4x14Gbps. Inter-channel crosstalk penalty is observed to be less than 0.5 dB and a transmission penalty around 1 dB. The power budget margin...

  18. Integration of GaAs-based VCSEL array on SiN platform with HCG reflectors for WDM applications

    Science.gov (United States)

    Kumari, Sulakshna; Gustavsson, Johan S.; Wang, Ruijun; Haglund, Emanuel P.; Westbergh, Petter; Sanchez, Dorian; Haglund, Erik; Haglund, Åsa; Bengtsson, Jörgen; Le Thomas, Nicolas; Roelkens, Gunther; Larsson, Anders; Baets, Roel

    2015-02-01

    We present a GaAs-based VCSEL structure, BCB bonded to a Si3N4 waveguide circuit, where one DBR is substituted by a free-standing Si3N4 high-contrast-grating (HCG) reflector realized in the Si3N4 waveguide layer. This design enables solutions for on-chip spectroscopic sensing, and the dense integration of 850-nm WDM data communication transmitters where individual channel wavelengths are set by varying the HCG parameters. RCWA shows that a 300nm-thick Si3N4 HCG with 800nm period and 40% duty cycle reflects strongly (HCG's influence on the VCSEL wavelength, allowing for a 15-nm-wide wavelength setting range with low threshold gain (<1000 cm-1).

  19. Impacts of environmental factors to bi-directional 2×40 Gb/s WDM free-space optical communication

    Science.gov (United States)

    Liaw, Shien-Kuei; Hsu, Kuang-Yu; Yeh, Jai-Ger; Lin, Yu-Ming; Yu, Yi-Lin

    2017-08-01

    Bi-directional short-range free-space optical (FSO) communication with bi-directional 2×4×10 Gb/s wavelength division multiplexing (WDM) channel signals is demonstrated by using a transmission distance of 25 m. The single-mode-fiber components are used in the optical terminals for both optical transmitting and receiving functions. The measured power penalties for the 25-m bi-directional four-channel FSO communication compared with the back-to-back link and uni-directional transmission system are less than 0.8 dB and 0.2 dB, respectively. The environmental factor effects, including the oblique incidence through the building window glasses, thermally induced non-uniform air index as well as rainfall on the FSO performance are investigated and analyzed. The experimental results show that rainfall is influential for free space optical transmission.

  20. Silicon/III-V laser with super-compact diffraction grating for WDM applications in electronic-photonic integrated circuits.

    Science.gov (United States)

    Wang, Yadong; Wei, Yongqiang; Huang, Yingyan; Tu, Yongming; Ng, Doris; Lee, Cheewei; Zheng, Yunan; Liu, Boyang; Ho, Seng-Tiong

    2011-01-31

    We have demonstrated a heterogeneously integrated III-V-on-Silicon laser based on an ultra-large-angle super-compact grating (SCG). The SCG enables single-wavelength operation due to its high-spectral-resolution aberration-free design, enabling wavelength division multiplexing (WDM) applications in Electronic-Photonic Integrated Circuits (EPICs). The SCG based Si/III-V laser is realized by fabricating the SCG on silicon-on-insulator (SOI) substrate. Optical gain is provided by electrically pumped heterogeneous integrated III-V material on silicon. Single-wavelength lasing at 1550 nm with an output power of over 2 mW and a lasing threshold of around 150 mA were achieved.

  1. Towards a SFP+ module for WDM applications using an ultra-widely-tunable high-speed MEMS-VCSEL

    Science.gov (United States)

    Paul, Sujoy; Cesar, Julijan; Malekizandi, Mohammadreza; Haidar, Mohammad T.; Heermeier, Niels; Ortsiefer, Markus; Neumeyr, Christian; Gréus, Christoph; Eiselt, Michael H.; Ibrahim, Irfan; Schmidt, Henning; Schmidt, Jörg; Küppers, Franko

    2017-02-01

    In this work, we have used a tunable VCSEL for high-speed optical data transmission. To obtain wide tunability, a MEMS-DBR is surface micromachined onto a short-cavity high-speed VCSEL operating at 1550 nm. Ultra-wide continuous tuning is realized with electro-thermal actuation of the MEMS with built-in stress gradient within SiOx/SiNy dielectric layers. The MEMS-VCSEL operates in single-mode with SMSR > 40 dB across the entire tuning range. Quasi-error-free transmission of direct-modulation at record 15 Gbps is reported for 20 nm tuning, showing the potential towards the standard requirements for the SFP+ modules in the tail-ends of the WDM transmission system.

  2. Bandwidth efficient bidirectional 5 Gb/s overlapped-SCM WDM PON with electronic equalization and forward-error correction.

    Science.gov (United States)

    Buset, Jonathan M; El-Sahn, Ziad A; Plant, David V

    2012-06-18

    We demonstrate an improved overlapped-subcarrier multiplexed (O-SCM) WDM PON architecture transmitting over a single feeder using cost sensitive intensity modulation/direct detection transceivers, data re-modulation and simple electronics. Incorporating electronic equalization and Reed-Solomon forward-error correction codes helps to overcome the bandwidth limitation of a remotely seeded reflective semiconductor optical amplifier (RSOA)-based ONU transmitter. The O-SCM architecture yields greater spectral efficiency and higher bit rates than many other SCM techniques while maintaining resilience to upstream impairments. We demonstrate full-duplex 5 Gb/s transmission over 20 km and analyze BER performance as a function of transmitted and received power. The architecture provides flexibility to network operators by relaxing common design constraints and enabling full-duplex operation at BER ∼ 10(-10) over a wide range of OLT launch powers from 3.5 to 8 dBm.

  3. WDM mid-board optics for chip-to-chip wavelength routing interconnects in the H2020 ICT-STREAMS

    Science.gov (United States)

    Kanellos, G. T.; Pleros, N.

    2017-02-01

    Multi-socket server boards have emerged to increase the processing power density on the board level and further flatten the data center networks beyond leaf-spine architectures. Scaling however the number of processors per board puts current electronic technologies into challenge, as it requires high bandwidth interconnects and high throughput switches with increased number of ports that are currently unavailable. On-board optical interconnection has proved the potential to efficiently satisfy the bandwidth needs, but their use has been limited to parallel links without performing any smart routing functionality. With CWDM optical interconnects already a commodity, cyclical wavelength routing proposed to fit the datacom for rack-to-rack and board-to-board communication now becomes a promising on-board routing platform. ICT-STREAMS is a European research project that aims to combine WDM parallel on-board transceivers with a cyclical AWGR, in order to create a new board-level, chip-to-chip interconnection paradigm that will leverage WDM parallel transmission to a powerful wavelength routing platform capable to interconnect multiple processors with unprecedented bandwidth and throughput capacity. Direct, any-to-any, on-board interconnection of multiple processors will significantly contribute to further flatten the data centers and facilitate east-west communication. In the present communication, we present ICT-STREAMS on-board wavelength routing architecture for multiple chip-to-chip interconnections and evaluate the overall system performance in terms of throughput and latency for several schemes and traffic profiles. We also review recent advances of the ICT-STREAMS platform key-enabling technologies that span from Si in-plane lasers and polymer based electro-optical circuit boards to silicon photonics transceivers and photonic-crystal amplifiers.

  4. Safety Profile and Costs of Related Adverse Events of Trastuzumab Emtansine for the Treatment of HER2-Positive Locally Advanced or Metastatic Breast Cancer Compared to Capecitabine Plus Lapatinib from the Perspective of the Canadian Health-Care System.

    Science.gov (United States)

    Piwko, Charles; Prady, Catherine; Yunger, Simon; Pollex, Erika; Moser, Aurelie

    2015-08-01

    Trastuzumab emtansine (T-DM1, KADCYLA(®)) is an antibody-drug conjugate comprised of the cytotoxic agent DM1 and trastuzumab (HERCEPTIN(®)). The safety profile of T-DM1 in human epidermal growth factor receptor 2 (HER2)-positive locally advanced or metastatic breast cancer previously treated with trastuzumab and a taxane was investigated in the phase III EMILIA trial. The trial demonstrated clinically and statistically meaningful differences in the safety profile between T-DM1 and capecitabine plus lapatinib (CAP + LAP). The objective of this study was to estimate the costs of managing treatment-related grade ≥ 3 adverse events (AEs) that occurred in ≥ 2% of patients and grade 2 AEs that occurred in ≥ 5% of patients taking T-DM1 compared with patients taking CAP + LAP based on the EMILIA trial, from the perspective of Canadian public payers. An Excel-based model was utilized to estimate the relevant costs. Clinical data were obtained from the EMILIA trial. Cost information was obtained from the literature, clinical experts, and standard cost sources. The analysis was conducted from the Canadian public-payer perspective and reported in 2014 Canadian dollars (CAD). The management of included treatment-related AEs resulted in higher estimated per-patient costs of CAD6901 for CAP + LAP versus CAD3380 for T-DM1, resulting in savings of CAD3521. From a Canadian perspective, this analysis demonstrated that utilizing T-DM1 for the management of HER2-positive metastatic breast cancer results in substantial savings to the public health-care system when considering the costs of treatment-related AEs, due to fewer amount of toxicities compared with CAP + LAP. Results of various sensitivity analyses investigating changes in number and costs of AEs confirmed the findings; however, the magnitude of cost savings varied. Further analyses are necessary to determine whether these cost savings would occur in other countries and health-care systems.

  5. Subscriber loop optical distribution architecture: a cost-effective TDM/TDMA subscriber loop system

    Science.gov (United States)

    Rueda, Javier; Eldering, Charles A.

    1992-02-01

    While it is clear that the development of the laser and low loss optical fiber has had an unmistakable impact on the field of telecommunications, the deployment of optical fiber in the subscriber (local) loop is an especially challenging task. It requires development of low cost equipment that will initially be used at low bit rates (Transmission of TV data, in either analog or digital form, will make more efficient use of the fiber bandwidth and generate additional revenues. But as seen from the perspective of the telephony industry, basic telephone services are the principal source of revenue and economic justification for the installation of subscriber loop fiber systems. For large scale deployment in the subscriber loop, the fiber optic system must provide basic telephone services with equal or better performance at a cost that is competitive with that of existing copper pair technology. In this paper we examine a number of possible fiber-to-the-home (FTTH) and fiber-to-the-curb (FTTC) architectures, and present an architecture for urban areas that is best classified as fiber-to-the-building (FTTB). We examine the costs and performance characteristics of the various networks. We show how demographic information can be used to optimize the capacity of the remote terminals. It is shown that for the demography of Spain (where in urban areas the majority of the population resides in apartment buildings with 10 or more dwellings) a remote terminal with a variable subscriber capacity presents a cost savings over remote terminals with a fixed number of subscriber channels.

  6. Optical phase conjugation by an As(2)S(3) glass planar waveguide for dispersion-free transmission of WDM-DPSK signals over fiber.

    Science.gov (United States)

    Pelusi, M D; Luan, F; Choi, D-Y; Madden, S J; Bulla, D A P; Luther-Davies, B; Eggleton, B J

    2010-12-06

    We report the first demonstration of optical phase conjugation (OPC) transmission of phase encoded and wavelength-division multiplexed (WDM) signals by the Kerr effect in a planar structured waveguide. The phase conjugated electric field of the signal is produced by four wave mixing pumped by a CW laser during co-propagating with the signal in a highly nonlinear waveguide fabricated in As(2)S(3) glass. Experiments demonstrate the capability of the device to perform dispersion-free transmission through up to 225 km of standard single mode fiber for a 3 × 40 Gb/s WDM signal, with its channels encoded as return-to-zero differential phase shift keying and spaced either 100 or 200 GHz apart. This work represents an important milestone towards demonstrating advanced signal processing of high-speed and broadband optical signals in compact planar waveguides, with the potential for monolithic optical integration.

  7. A WDM-PON with DPSK modulated downstream and OOK modulated upstream signals based on symmetric 10 Gbit/s wavelength reused bidirectional reflective SOA

    Science.gov (United States)

    El-Nahal, Fady I.

    2017-01-01

    We investigate a wavelength-division-multiplexing passive optical network (WDM-PON) with centralized lightwave and direct detection. The system is demonstrated for symmetric 10 Gbit/s differential phase-shift keying (DPSK) downstream signals and on-off keying (OOK) upstream signals, respectively. A wavelength reused scheme is employed to carry the upstream data by using a reflective semiconductor optical amplifier (RSOA) as an intensity modulator at the optical network unit (ONU). The constant-intensity property of the DPSK modulation format can keep high extinction ratio ( ER) of downstream signal and reduce the crosstalk to the upstream signal. The bit error rate ( BER) performance of our scheme shows that the proposed 10 Gbit/s symmetric WDM-PON can achieve error free transmission over 25-km-long fiber transmission with low power penalty.

  8. Multifunctional switching unit for add/drop, wavelength conversion, format conversion, and WDM multicast based on bidirectional LCoS and SOA-loop architecture.

    Science.gov (United States)

    Wang, Danshi; Zhang, Min; Qin, Jun; Lu, Guo-Wei; Wang, Hongxiang; Huang, Shanguo

    2014-09-08

    We propose a multifunctional optical switching unit based on the bidirectional liquid crystal on silicon (LCoS) and semiconductor optical amplifier (SOA) architecture. Add/drop, wavelength conversion, format conversion, and WDM multicast are experimentally demonstrated. Due to the bidirectional characteristic, the LCoS device cannot only multiplex the input signals, but also de-multiplex the converted signals. Dual-channel wavelength conversion and format conversion from 2 × 25Gbps differential quadrature phase-shift-keying (DQPSK) to 2 × 12.5Gbps differential phase-shift-keying (DPSK) based on four-wave mixing (FWM) in SOA is obtained with only one pump. One-to-six WDM multicast of 25Gbps DQPSK signals with two pumps is also achieved. All of the multicast channels are with a power penalty less than 1.1 dB at FEC threshold of 3.8 × 10⁻³.

  9. A rigorous analysis of digital pre-emphasis and DAC resolution for interleaved DAC Nyquist-WDM signal generation in high-speed coherent optical transmission systems

    Science.gov (United States)

    Weng, Yi; Wang, Junyi; He, Xuan; Pan, Zhongqi

    2018-02-01

    The Nyquist spectral shaping techniques facilitate a promising solution to enhance spectral efficiency (SE) and further reduce the cost-per-bit in high-speed wavelength-division multiplexing (WDM) transmission systems. Hypothetically, any Nyquist WDM signals with arbitrary shapes can be generated by the use of the digital signal processing (DSP) based electrical filters (E-filter). Nonetheless, in actual 100G/ 200G coherent systems, the performance as well as DSP complexity are increasingly restricted by cost and power consumption. Henceforward it is indispensable to optimize DSP to accomplish the preferred performance at the least complexity. In this paper, we systematically investigated the minimum requirements and challenges of Nyquist WDM signal generation, particularly for higher-order modulation formats, including 16 quadrature amplitude modulation (QAM) or 64QAM. A variety of interrelated parameters, such as channel spacing and roll-off factor, have been evaluated to optimize the requirements of the digital-to-analog converter (DAC) resolution and transmitter E-filter bandwidth. The impact of spectral pre-emphasis has been predominantly enhanced via the proposed interleaved DAC architecture by at least 4%, and hence reducing the required optical signal to noise ratio (OSNR) at a bit error rate (BER) of 10-3 by over 0.45 dB at a channel spacing of 1.05 symbol rate and an optimized roll-off factor of 0.1. Furthermore, the requirements of sampling rate for different types of super-Gaussian E-filters are discussed for 64QAM Nyquist WDM transmission systems. Finally, the impact of the non-50% duty cycle error between sub-DACs upon the quality of the generated signals for the interleaved DAC structure has been analyzed.

  10. Quad 14 Gbps L-band VCSEL-based system for WDM migration of 4-lanes 56 Gbps optical data links.

    Science.gov (United States)

    Estaran, Jose; Rodes, Roberto; Pham, Tien Thang; Ortsiefer, Markus; Neumeyr, Christian; Rosskopf, Jürgen; Monroy, Idelfonso Tafur

    2012-12-17

    We report on migrating multiple-lane link into an L-band VCSEL-based WDM system. Experimental validation achieves successful transmission over 10 km of SMF at 4x14Gbps. Inter-channel crosstalk penalty is observed to be less than 0.5 dB and a transmission penalty around 1 dB. The power budget margin ranges within 6 dB and 7 dB.

  11. [New Hope for HER2-Positive Metastatic Breast Cancer Treatment: Trastuzumab Emtansine (T-DM1) From the Perspective of Nursing Care].

    Science.gov (United States)

    Kuo, Hsiao-Hsuan; Chen, Wei-Wu

    2016-10-01

    Human epidermal growth factor receptor (HER2)-positive breast cancer is associated with a more aggressive disease and poor prognosis. The development of trastuzumab, a HER2-targeted agent, has changed the paradigm of HER2-positive breast cancer treatment and improved survival rates dramatically. However, metastatic HER2-positive breast cancer patients eventually develop resistance to this treatment regimen eventually. A new anti-HER2 antibody-drug conjugate, Trastuzumab emtansine (T-DM1), has been shown to improve treatment efficacy. However, side effects that differ from trastuzumab, including thrombocytopenia, liver dysfunction, fatigue, cardiotoxicity, pneumonitis, and peripheral neuropathy, may occur. Clinical nurses must understand the mechanism of this new agent and be aware of the symptoms and signs related to its side effects. Furthermore, clinical nurses should understand the varying degrees of these side effects, their probable causes, and the potential approaches to their management. Finally, clinical nurses must understand how to administer this agent in order to ensure patient safety. Understanding the side effects of T-DM1 and their management will help elevate nursing quality and caring efficacy.

  12. Molecular imaging as a tool to investigate heterogeneity of advanced HER2-positive breast cancer and to predict patient outcome under trastuzumab emtansine (T-DM1) : the ZEPHIR trial

    NARCIS (Netherlands)

    Gebhart, G.; Lamberts, L. E.; Wimana, Z.; Garcia, C.; Emonts, P.; Ameye, L.; Stroobants, S.; Huizing, M.; Aftimos, P.; Tol, J.; Oyen, W. J. G.; Vugts, D. J.; Hoekstra, O. S.; Schroder, C. P.; van Oordt, C. W. Menke-van der Houven; Guiot, T.; Brouwers, A. H.; Awada, A.; de Vries, E. G. E.; Flamen, P.

    Molecular imaging of metastatic human epidermal growth factor receptor 2 (HER2)-positive breast cancer reveals marked intra- and interpatient heterogeneity in HER2 mapping, which correlates with clinical outcome under T-DM1 therapy.Only human epidermal growth factor receptor (HER)2 status determined

  13. Molecular imaging as a tool to investigate heterogeneity of advanced HER2-positive breast cancer and to predict patient outcome under trastuzumab emtansine (T-DM1): the ZEPHIR trial

    NARCIS (Netherlands)

    Gebhart, G.; Lamberts, L.E.; Wimana, Z.; Garcia, C.; Emonts, P.; Ameye, L.; Stroobants, S.; Huizing, M.; Aftimos, P.; Tol, J.; Oyen, W.J.G.; Vugts, D.J.; Hoekstra, O.S.; Schroder, C.P.; Oordt, C.W. Menke-van der H; Guiot, T.; Brouwers, A.H.; Awada, A.; Vries, E.G. de; Flamen, P.

    2016-01-01

    BACKGROUND: Only human epidermal growth factor receptor (HER)2 status determined by immunohistochemistry (IHC) and fluorescence in situ hybridization (FISH) has been validated to predict efficacy of HER2-targeting antibody-drug-conjugate trastuzumab emtansine (T-DM1). We propose molecular imaging to

  14. Superior in vitro and in vivo activity of trastuzumab-emtansine (T-DM1) in comparison to trastuzumab, pertuzumab and their combination in epithelial ovarian carcinoma with high HER2/neu expression.

    Science.gov (United States)

    Menderes, Gulden; Bonazzoli, Elena; Bellone, Stefania; Altwerger, Gary; Black, Jonathan D; Dugan, Katherine; Pettinella, Francesca; Masserdotti, Alice; Riccio, Francesco; Bianchi, Anna; Zammataro, Luca; de Haydu, Christopher; Buza, Natalia; Hui, Pei; Wong, Serena; Huang, Gloria S; Litkouhi, Babak; Ratner, Elena; Silasi, Dan-Arin; Azodi, Masoud; Schwartz, Peter E; Santin, Alessandro D

    2017-10-01

    Epithelial ovarian cancer (EOC) remains the most lethal gynecologic malignancy. The objective of this study was to compare the anti-tumor activity of HER2/neu-targeting monoclonal antibodies, trastuzumab (T), pertuzumab (P), combination of trastuzumab and pertuzumab (T+P) and trastuzumab-emtansine (T-DM1) in EOC with high HER2/neu expression. Primary EOC cell lines were established and cell blocks were analyzed for HER2/neu expression. Cytostatic, apoptotic and antibody-dependent cell-mediated cytotoxicity (ADCC) activities of T, P, T+P and T-DM1 were evaluated in vitro. The in vivo antitumor activity was tested in xenograft models with 3+ HER2/neu expression. High (3+) HER2/neu expression was detected in 40% of the primary EOC cell lines. T, P, T+P, and T-DM1 were similarly effective in inducing strong ADCC against primary EOC cell lines expressing 3+ HER2/neu. The combination of T and P was more cytostatic when compared with that of T or P used alone (pHER2/neu when compared to T alone, P alone and T+P (p=0.04). In vitro and in vivo experiments with 3+ HER2/neu expressing EOC revealed limited anti-tumor activity of T or P. T-DM1 showed superior anti-tumor activity to T and P as single agents and as a combination. Our preclinical data support the design of clinical studies with T-DM1 for the treatment of chemotherapy-resistant EOC overexpressing HER2/neu. Copyright © 2017 Elsevier Inc. All rights reserved.

  15. Impairments Computation for Routing Purposes in a Transparent-Access Optical Network Based on Optical CDMA and WDM

    Science.gov (United States)

    Musa, Ahmed

    2016-06-01

    Optical access networks are becoming more widespread and the use of multiple services might require a transparent optical network (TON). Multiplexing and privacy could benefit from the combination of wavelength division multiplexing (WDM) and optical coding (OC) and wavelength conversion in optical switches. The routing process needs to be cognizant of different resource types and characteristics such as fiber types, fiber linear impairments such as attenuation, dispersion, etc. as well as fiber nonlinear impairments such as four-wave mixing, cross-phase modulation, etc. Other types of impairments, generated by optical nodes or photonic switches, also affect the signal quality (Q) or the optical signal to noise ratio (OSNR), which is related to the bit error rate (BER). Therefore, both link and switch impairments must be addressed and somehow incorporated into the routing algorithm. However, it is not practical to fully integrate all photonic-specific attributes in the routing process. In this study, new routing parameters and constraints are defined that reflect the distinct characteristics of photonic networking. These constraints are applied to the design phase of TON and expressed as a cost or metric form that will be used in the network routing algorithm.

  16. Using single side-band modulation for colorless OFDM-WDM access network to alleviate Rayleigh backscattering effects.

    Science.gov (United States)

    Yeh, Chien-Hung; Chow, Chi-Wai

    2016-05-16

    In this investigation, we demonstrate a new colorless orthogonal-frequency-division-multiplexing (OFDM) wavelength-division-multiplexing passive optical network (WDM-PON) system with Rayleigh backscattering (RB) noise mitigation. Here, only a single laser source at the central office (CO) is needed to produce the downstream signal and distributed continuous-wave (CW) carrier, which will then be modulated at the optical networking unit (ONU) to produce the upstream signal. Single side-band (SSB) modulation is used to wavelength-shift the distributed CW carrier, which will be launched into a reflective semiconductor optical amplifier (RSOA) based ONU for directly modulation of 5.15 Gbps OFDM upstream signal. To avoid the radio-frequency (RF) power fading and chromatic fiber dispersion, the four-band OFDM modulation is proposed to generate a 40 Gbps downstream when a Mach-Zehnder modulator (MZM) with -0.7 chirp parameter is used. Hence, the RB circumvention can be centralized in the CO. Moreover, the signal performances of downstream and upstream are also studied and discussed in this measurement.

  17. A flexible decision-aided maximum likelihood phase estimation in hybrid QPSK/OOK coherent optical WDM systems

    Science.gov (United States)

    Zhang, Yong; Wang, Yulong

    2016-04-01

    Although decision-aided (DA) maximum likelihood (ML) phase estimation (PE) algorithm has been investigated intensively, block length effect impacts system performance and leads to the increasing of hardware complexity. In this paper, a flexible DA-ML algorithm is proposed in hybrid QPSK/OOK coherent optical wavelength division multiplexed (WDM) systems. We present a general cross phase modulation (XPM) model based on Volterra series transfer function (VSTF) method to describe XPM effects induced by OOK channels at the end of dispersion management (DM) fiber links. Based on our model, the weighted factors obtained from maximum likelihood method are introduced to eliminate the block length effect. We derive the analytical expression of phase error variance for the performance prediction of coherent receiver with the flexible DA-ML algorithm. Bit error ratio (BER) performance is evaluated and compared through both theoretical derivation and Monte Carlo (MC) simulation. The results show that our flexible DA-ML algorithm has significant improvement in performance compared with the conventional DA-ML algorithm as block length is a fixed value. Compared with the conventional DA-ML with optimum block length, our flexible DA-ML can obtain better system performance. It means our flexible DA-ML algorithm is more effective for mitigating phase noise than conventional DA-ML algorithm.

  18. 10 Gbps WDM transmission performance limits using in-line SOAs and an optical phase conjugator based on four-wave mixing in SOAs as a mid-span spectral inversion technique.

    Science.gov (United States)

    Hur, Sub; Kim, Yonggyou; Jang, Hodeok; Jeong, Jichai

    2006-05-29

    We have theoretically investigated the transmission performance limits of all semiconductor optical amplifiers (SOA)-based 10 Gb/s wavelength division multiplexing (WDM) systems using in-line SOAs and an optical phase conjugator (OPC) based on four-wave mixing in SOAs as a mid-span spectral inversion technique. With a verified numerical model of SOAs, we have found that the crosstalk from SOAs in OPC is a dominant factor to limit the number of channels in WDM systems. In order to increase the available number of channels, we optimize the input optical power and the injection current to SOAs in OPC with using a reservoir channel in in-line SOAs. All SOA-based 10 Gb/s WDM systems using the OPC can transmit 16 channel signals up to 240 km distance with a 3 dB power penalty.

  19. FLAMINGO: A Packet-switched IP-over-WDM All-optical MAN

    NARCIS (Netherlands)

    Dey, D.; van Bochove, A.C.; Koonen, A.M.J.; Geuzebroek, D.H.; Salvador, M.R.; Verbeek, B.H.; prof.dr.ir. Demeester, P.

    2001-01-01

    FLAMINGO (flexible multiwavelength optical local access network supporting multimedia broadband services) is a research project supported by the Dutch Technology Foundation, STW. We describe the architecture for the all-optical wavelength-and-time-slotted MAN. Key aspects of this architecture

  20. Generation of 1.024-Tb/s Nyquist-WDM phase-conjugated twin vector waves by a polarization-insensitive optical parametric amplifier for fiber-nonlinearity-tolerant transmission

    OpenAIRE

    Liu, Xiang(Research Center for Hadron and CSR Physics, Lanzhou University, Institute of Modern Physics of CAS, Lanzhou 730000, China); Hu, Hao; Chandrasekhar, S.; Jopson, R. M.; Gnauck, A. H.; Dinu, M.; Xie, C; Winzer, P. J.

    2014-01-01

    We experimentally demonstrate the generation of 1.024-Tb/s Nyquist-WDM phase-conjugated vector twin waves (PCTWs), consisting of eight 128-Gb/s polarization-division-multiplexed QPSK signals and their idlers, by a broadband polarization-insensitive fiber optic parametric amplifier. This novel all-optical signal processing approach to generate WDM-PCTWs enables a 2-fold reduction in the needed optical transmitters as compared to the conventional approach where each idler is generated by a dedi...

  1. Evaluation of correlated digital back propagation and extended Kalman filtering for non-linear mitigation in PM-16-QAM WDM systems

    Science.gov (United States)

    Pakala, Lalitha; Schmauss, Bernhard

    2017-01-01

    We investigate the individual and combined performance of correlated digital back propagation (CDBP) and extended Kalman filtering (EKF) in mitigating inter and intra-channel non-linearities in wavelength division multiplexed (WDM) systems. The afore-mentioned algorithms are verified through numerical simulations on 28 Gbaud polarization multiplexed (PM) 16-quadrature amplitude modulation (16-QAM) 9-channel WDM system with 50 GHz spacing. A single channel CDBP with one-step-per-span based on asymmetric split step Fourier method (A-SSFM) with optimized non-linear coefficient has been employed. We also study an amplitude dependent optimization (AO) of the non-linear coefficient for CDBP which shows an improvement of ≍ 0.8 dB compared to the conventional optimized CDBP, in the non-linear regime. Moreover, our proposed carrier phase and amplitude noise estimation (CPANE) algorithm based on EKF outperforms AO-CDBP in both linear and non-linear regimes with an enhanced performance besides significantly reduced complexity. We further investigate the combined performance of AO-CDBP and EKF which results in an enhanced non-linear tolerance at the expense of increased computational cost trading off to the number of required CDBP steps per span. Furthermore, we also analyze the impact of cross phase modulation (XPM) on the combined performance of AO-CDBP and EKF by varying the number of WDM channels. Numerical results show that the obtained gain from employing AO-CDBP prior to EKF reduces with increasing effects of XPM. Additionally, we also discuss the computational complexity of the aforementioned algorithms.

  2. Watershed Data Management (WDM) database for West Branch DuPage River streamflow simulation, DuPage County, Illinois, January 1, 2007, through September 30, 2013

    Science.gov (United States)

    Bera, Maitreyee

    2017-10-16

    The U.S. Geological Survey (USGS), in cooperation with the DuPage County Stormwater Management Department, maintains a database of hourly meteorological and hydrologic data for use in a near real-time streamflow simulation system. This system is used in the management and operation of reservoirs and other flood-control structures in the West Branch DuPage River watershed in DuPage County, Illinois. The majority of the precipitation data are collected from a tipping-bucket rain-gage network located in and near DuPage County. The other meteorological data (air temperature, dewpoint temperature, wind speed, and solar radiation) are collected at Argonne National Laboratory in Argonne, Ill. Potential evapotranspiration is computed from the meteorological data using the computer program LXPET (Lamoreux Potential Evapotranspiration). The hydrologic data (water-surface elevation [stage] and discharge) are collected at U.S.Geological Survey streamflow-gaging stations in and around DuPage County. These data are stored in a Watershed Data Management (WDM) database.This report describes a version of the WDM database that is quality-assured and quality-controlled annually to ensure datasets are complete and accurate. This database is named WBDR13.WDM. It contains data from January 1, 2007, through September 30, 2013. Each precipitation dataset may have time periods of inaccurate data. This report describes the methods used to estimate the data for the periods of missing, erroneous, or snowfall-affected data and thereby improve the accuracy of these data. The other meteorological datasets are described in detail in Over and others (2010), and the hydrologic datasets in the database are fully described in the online USGS annual water data reports for Illinois (U.S. Geological Survey, 2016) and, therefore, are described in less detail than the precipitation datasets in this report.

  3. Design of universal fiber with demonstration of full system reaches over 100G SR4, 40G sWDM, and 100G CWDM4 transceivers.

    Science.gov (United States)

    Chen, Xin; Hurley, Jason E; Stone, Jeffery S; Zakharian, Aramais R; Coleman, Doug; Li, Ming-Jun

    2016-08-08

    Universal fiber has an LP01 mode field diameter approximately matched to that of standard single mode fiber, while being a multimode fiber. We analyzed the dependence of the mode field diameter on the core diameter for different core delta values. Guided by the analysis, a universal fiber having a delta of 1.2% was fabricated, showing significantly reduced coupling loss of ~2.3 dB with conventional multimode fiber. We demonstrated that the fiber can transmit with full system reach in both single mode and VCSEL-based multimode transmissions, including 100G SR4, 40G sWDM, and 100G CWDM4 for the first time.

  4. Improvement of input power dynamic range for 20 Gbit/s optical WDM switch nodes using an integrated Michelson wavelength converter

    DEFF Research Database (Denmark)

    Danielsen, Søren Lykke; Hansen, Peter Bukhave; Jørgensen, Carsten

    1997-01-01

    The implementation of photonic wavelength-division multiplexing (WDM) switch nodes with wavelength converters allows for higher throughput and easier management, as well as wavelength reuse. Furthermore, semiconductor optical amplifiers (SOAs) are attractive for space switching in the nodes because...... saturation. We show that even at a high bit-rate of 20 Gbit/s the latter imperfection can be compensated by the extinction ratio enhancing capability of interferometric wavelength converters (IWCs). Consequently, the input power dynamic range for switch blocks using IWCs together with SOA gates can...

  5. Efectos no lineales y su relación con los parámetros de transmisión de una red WDM

    Directory of Open Access Journals (Sweden)

    Juan Pablo Agredo

    2011-07-01

    Full Text Available Se analizan las degradaciones ópticas en una red de Multiplexación por División de Longitud de Onda (WDM –Wavelength Division Multiplexing– y se estudia el impacto de los parámetros de transmisión en los efectos no lineales; además, se determinan las variaciones que se deben llevar a cabo en dichos parámetros, con la finalidad de minimizar este tipo de degradaciones y optimizar el desempeño de la red.

  6. Efectos no lineales y su relación con los parámetros de transmisión de una red WDM

    Directory of Open Access Journals (Sweden)

    José Giovanny López Perafán

    2012-05-01

    Full Text Available Se analizan las degradaciones ópticas en una red de Multiplexación por División de Longitud de Onda (WDM –Wavelength Division Multiplexing– y se estudia el impacto de los parámetros de transmisión en los efectos no lineales; además, se determinan las variaciones que se deben llevar a cabo en dichos parámetros, con la finalidad de minimizar este tipo de degradaciones y optimizar el desempeño de la red.

  7. Local Foods, Local Places

    Science.gov (United States)

    The Local Foods, Local Places technical assistance program protects human health and the environment, spurs revitalization, increases access to healthy foods, and creates economic opportunities by promoting local foods.

  8. INFLUENCE OF POLARIZATION MODE DISPERSION ON THE EFFECT OF CROSS-PHASE MODULATION IN INTENSITY MODULATION-DIRECT DETECTION WDM TRANSMISSION SYSTEM

    Directory of Open Access Journals (Sweden)

    M S Islam

    2010-03-01

    Full Text Available Cross-phase modulation (XPM changes the state-of-polarization (SOP of the channels through nonlinear polarization rotation and induces nonlinear time dependent phase shift for polarization components that leads to amplitude modulation of the propagating waves in a wavelength division multiplexing (WDM system. Due to the presence of birefringence, the angle between the SOP changes randomly and as a result polarization mode dispersion (PMD causes XPM modulation amplitude fluctuation random in the perturbed channel. In this paper we analytically determine the probability density function of the random angle between the SOP of pump and probe, and evaluate the impact of polarization mode dispersion on XPM in terms of bit error rate, channel spacing etc for a two channel intensity modulation-direct detection WDM system at 10 Gb/s. It is found that the XPM induced crosstalk is polarization independent for channel spacing greater than 3 nm or PMD coefficient larger than 2 ps/√km. We also investigate the dependence of SOP variance on PMD coefficient and channel spacing.

  9. Single Source 5-dimensional (Space-, Wavelength-, Time-, Polarization-, Quadrature-) 43 Tbit/s Data Transmission of 6 SDM × 6 WDM × 1.2 Tbit/s Nyquist-OTDM-PDM-QPSK

    DEFF Research Database (Denmark)

    Hu, Hao; Ye, Feihong; Medhin, Ashenafi Kiros

    2014-01-01

    We demonstrate 43-Tbit/s transmission over 67.4-km seven-core fiber using a single source. Each of the 6 outer cores carries 6 Nyquist-WDM channels using 320-Gbaud Nyquist- OTDM-PDM-QPSK 330-GHz spaced, and the center core carries 10-GHz clock pulses....

  10. Generation of 1.024-Tb/s Nyquist-WDM phase-conjugated twin vector waves through polarization-insensitive optical parametric amplification enabling transmission over 4000-km dispersion-managed TWRS fiber

    DEFF Research Database (Denmark)

    Liu, Xiang; Hu, Hao; Chandrasekhar, S.

    2013-01-01

    We experimentally demonstrate the first Tb/s Nyquist-WDM phase-conjugated twin waves, consisting of eight 128-Gb/s PDM-QPSK signals and their idlers, by a broadband polarization-insensitive fiber optical parametric amplifier, enabling more than doubled reach in dispersion-managed transmission...

  11. DWDM channel spacing tunable optical TDM carrier from a mode-locked weak-resonant-cavity Fabry-Perot laser diode based fiber ring.

    Science.gov (United States)

    Peng, Guo-Hsuan; Chi, Yu-Chieh; Lin, Gong-Ru

    2008-08-18

    A novel optical TDM pulsed carrier with tunable mode spacing matching the ITU-T defined DWDM channels is demonstrated, which is generated from an optically injection-mode-locked weak-resonant-cavity Fabry-Perot laser diode (FPLD) with 10%-end-facet reflectivity. The FPLD exhibits relatively weak cavity modes and a gain spectral linewidth covering >33.5 nm. The least common multiple of the mode spacing determined by both the weak-resonant-cavity FPLD and the fiber-ring cavity can be tunable by adjusting length of the fiber ring cavity or the FPLD temperature to approach the desired 200GHz DWDM channel spacing of 1.6 nm. At a specific fiber-ring cavity length, such a least-common- multiple selection rule results in 12 lasing modes between 1532 and 1545 nm naturally and a mode-locking pulsewidth of 19 ps broadened by group velocity dispersion among different modes. With an additional intracavity bandpass filter, the operating wavelength can further extend from 1520 to 1553.5 nm. After channel filtering, each selected longitudinal mode gives rise to a shortened pulsewidth of 12 ps due to the reduced group velocity dispersion. By linear dispersion compensating with a 55-m long dispersion compensation fiber (DCF), the pulsewidth can be further compressed to 8 ps with its corresponding peak-to-peak chirp reducing from 9.7 to 4.3 GHz.

  12. A Energy-Saving Path-Shared Protection Based on Diversity Network Coding for Multi-rate Multicast in WDM Mesh Networks

    Science.gov (United States)

    Zheng, Danling; Lv, Lei; Liu, Huanlin

    2017-08-01

    For improving the survivability and energy saving of multi-rate multicast, a novel energy-saving path-shared protection based on diversity network coding (EPP-DNC) for multi-rate multicast in wavelength division multiplexing (WDM) mesh networks is proposed in the paper. In the EPP-DNC algorithm, diversity network coding on the source node for multi-rate multicast is adopted to reduce the coding energy consumption by avoiding network coding on the network's intermediate nodes. To decrease the transmission energy, shortest path shared based on heuristic is proposed to transmit the protection information for the request. To provision request's working paths efficiency, the working paths are routed on the preselected P-cycles with minimum required links and minimum energy consumption. Simulation results show that the proposed EPP-DNC can save energy consumption and improve bandwidth utilization.

  13. On-the-field performance of quintuple-play long-reach OFDM-based WDM-PON optical access networks.

    Science.gov (United States)

    Llorente, Roberto; Morant, Maria; Pellicer, Eloy; Herman, Milan; Nagy, Zsolt; Alves, Tiago; Cartaxo, Adolfo; Herrera, Javier; Correcher, Jose; Quinlan, Terence; Walker, Stuart; Rodrigues, Cláudio; Cluzeaud, Pierre; Schmidt, Axel; Piesiewicz, Radoslaw; Sambaraju, Rakesh

    2014-03-24

    In this paper the on-the-field performance of a WDM-PON optical access providing quintuple-play services using orthogonal frequency division multiplexing (OFDM) modulation is evaluated in a real fiber-to-the-home (FTTH) network deployed by Towercom operator in Bratislava (Slovakia). A bundle of quintuple-play services comprising full-standard OFDM-based signals (LTE, WiMAX, UWB and DVB-T) and an ad-hoc OFDM-GbE signal is transmitted in coexistence per single user. Both downstream and upstream transmission performances are evaluated in different on-the-field long-reach optical link distance configurations. Four wavelength multi-user transmission of quintuple-play OFDM services is demonstrated exceeding 60.8 km reach in standard single mode fiber.

  14. Directly modulated and fully tunable hybrid silicon lasers for future generation of coherent colorless ONU.

    Science.gov (United States)

    de Valicourt, G; Le Liepvre, A; Vacondio, F; Simonneau, C; Lamponi, M; Jany, C; Accard, A; Lelarge, F; Make, D; Poingt, F; Duan, G H; Fedeli, J-M; Messaoudene, S; Bordel, D; Lorcy, L; Antona, J-C; Bigo, S

    2012-12-10

    We propose and demonstrate asymmetric 10 Gbit/s upstream--100 Gbit/s downstream per wavelength colorless WDM/TDM PON using a novel hybrid-silicon chip integrating two tunable lasers. The first laser is directly modulated in burst mode for upstream transmission over up to 25 km of standard single mode fiber and error free transmission over 4 channels across the C-band is demonstrated. The second tunable laser is successfully used as local oscillator in a coherent receiver across the C-band simultaneously operating with the presence of 80 downstream co-channels.

  15. Simultaneous generation of independent wired and 60-GHz wireless signals in an integrated WDM-PON-RoF system based on frequency-sextupling and OCS-DPSK modulation.

    Science.gov (United States)

    Zhang, Liang; Hu, Xiaofeng; Cao, Pan; Chang, Qingjiang; Su, Yikai

    2012-06-18

    We propose a simple and cost-effective scheme to integrate a wavelength division multiplexed-passive optical network (WDM-PON) with a 60-GHz radio-over-fiber (RoF) system. In optical line terminal/central station (OLT/CS), 10-GHz electronic devices and single-drive Mach-Zehnder modulators (MZMs) are used to generate 60-GHz wireless signals based on frequency-sextupling and optical carrier suppression-differential phase shift keying (OCS-DPSK) modulation. By designing a new architecture, only N + 1 single-drive MZMs are required for an N-channel WDM-PON-RoF converged system. The proposed scheme is experimentally demonstrated with 1.25-Gb/s independent wired, wireless and upstream data. Error-free performances are achieved for all these signals after transmission of 25-km single mode fiber (SMF).

  16. Generation of 1.024-Tb/s Nyquist-WDM phase-conjugated twin vector waves by a polarization-insensitive optical parametric amplifier for fiber-nonlinearity-tolerant transmission

    DEFF Research Database (Denmark)

    Liu, Xiang; Hu, Hao; Chandrasekhar, S.

    2014-01-01

    We experimentally demonstrate the generation of 1.024-Tb/s Nyquist-WDM phase-conjugated vector twin waves (PCTWs), consisting of eight 128-Gb/s polarization-division-multiplexed QPSK signals and their idlers, by a broadband polarization-insensitive fiber optic parametric amplifier. This novel all...... reach in a dispersion-managed transmission link. We further study the impact of polarization-mode dispersion on the performance gain brought by the phase-conjugated twin waves, showing a gain of ∼3.8 dB in signal quality factors.......-optical signal processing approach to generate WDM-PCTWs enables a 2-fold reduction in the needed optical transmitters as compared to the conventional approach where each idler is generated by a dedicated transmitter. Digital coherent superposition of the twin waves at the receiver enables more than doubled...

  17. Monitoring burst (M-burst) — A novel framework of failure localization in all-optical mesh networks

    KAUST Repository

    Ali, Mohammed L.

    2011-10-10

    Achieving instantaneous and precise failure localization in all-optical wavelength division multiplexing (WDM) networks has been an attractive feature of network fault management systems, and is particularly important when failure-dependent protection is employed. The paper introduces a novel framework of real-time failure localization in all-optical WDM mesh networks, called monitoring-burst (m-burst), which aims to initiate a graceful compromise between consumed monitoring resources and monitoring delay. Different from any previously reported solution, the proposed m-burst framework has a single monitoring node (MN) which launches optical bursts along a set of pre-defined close-loop routes, called monitoring cycles (m-cycles), to probe the links along the m-cycles. Bursts along different m-cycles are kept non-overlapping through any link of the network. By identifying the lost bursts due to single link failure events only, the MN can unambiguously localize the failed link in at least 3-connected networks. We will justify the feasibility and applicability of the proposed m-burst framework in the scenario of interest. To avoid possible collision among optical bursts launched by the MN, we define the problem of collision-free scheduling and formulate it into an integer linear program (ILP) in order to minimize the monitoring delay. Numerical results demonstrate the effectiveness of the proposed framework and the proposed solution.

  18. Évaluation d’un module électro-optique hybride combinant la photonique sur silicium et sur verre pour des applications de multiplexage en longueur d’onde (WDM)

    OpenAIRE

    Ayi-Yovo, Folly Eli

    2017-01-01

    The ever-increasing demand for telecommunications needs has highlighted the intrinsic limitations of electronics. Photonics has proven to be a suitable solution to its limitations. STMicroelectronics has developed a silicon photonic platform called PIC25G that allows single-channel transmission at 25 Gb/s. The data rate increase with wavelength division multiplexing (WDM) encounter some constraints. The proposed solution is based on a hybrid approach integrating silicon photonics and glass io...

  19. Performance analysis of a threshold-based parallel multiple beam selection scheme for WDM-based systems for Gamma-Gamma distributions

    KAUST Repository

    Nam, Sung Sik

    2017-03-02

    In this paper, we statistically analyze the performance of a threshold-based parallel multiple beam selection scheme (TPMBS) for Free-space optical (FSO) based system with wavelength division multiplexing (WDM) in cases where a pointing error has occurred for practical consideration over independent identically distributed (i.i.d.) Gamma-Gamma fading conditions. Specifically, we statistically analyze the characteristics in operation under conventional heterodyne detection (HD) scheme for both adaptive modulation (AM) case in addition to non-AM case (i.e., coherentnon-coherent binary modulation). Then, based on the statistically derived results, we evaluate the outage probability (CDF) of a selected beam, the average spectral efficiency (ASE), the average number of selected beams (ANSB), and the average bit error rate (BER). Some selected results shows that we can obtain the higher spectral efficiency and simultaneously reduce the potential increasing of the complexity of implementation caused by applying the selection based beam selection scheme without a considerable performance loss.

  20. Performance analysis of 112 Gb/s×4-channel WDM PDM-DQPSK optical label switching system with spectral amplitude code labels

    Science.gov (United States)

    Aboagye, Isaac Adjaye; Chen, Fushen; Cao, Yongsheng

    2017-03-01

    We present the performance analysis of 112 Gb/s×4 wavelength division multiplexing (WDM) 100 GHz channel spacing polarization division multiplexed-differential quadrature phase shift keying (PDM-DQPSK) optical label switching system with frequency swept coherent detected spectral amplitude code labels. Direct detection is chosen to demodulate the payload by applying a polarization tracker, while 4-bits of 156 Mb/s spectral amplitude code label is coherently detected with a scheme of frequently-swept coherent detection. We optimize the payload laser linewidth as well as the frequency spacing between the payload and label. The label and payload signal performances are assessed by the eye-diagram opening factor (EOF) and bit-error rate (BER) at 10-9 as a function of the received optical power (ROP) and the optical signal to noise ratio (OSNR). The payload could well be demodulated after 900 km at a bit error rate of 10‒3 using forward error correction (FEC).

  1. Generation and transmission of 8 × 112-Gb/s WDM PDM-16QAM on a 25-GHz grid with simplified heterodyne detection.

    Science.gov (United States)

    Dong, Ze; Li, Xinying; Yu, Jianguo; Yu, Jianjun

    2013-01-28

    We propose and experimentally demonstrate a coherent receiver based on simplified heterodyne detection for 100 G polarization division multiplexing (PDM) signal. Compared to the conventional homodyne detection, only two balanced photo detectors (PDs) and two analog-to-digital converters (ADCs) are used in the simplified heterodyne detection. Compared to the conventional hybrid for homodyne detection, the polarization-diversity hybrid here is also simplified. The in-phase/quadrature (I/Q) separation and corresponding digital signal processing (DSP) following downconversion are realized in digital domain after ADCs. Using this scheme, we successfully demonstrated 8 × 112-Gb/s wavelength-division-multiplexing (WDM) polarization-division-multiplexing 16-ary quadrature amplitude modulation (PDM-16QAM) over 720-km single-mode fiber (SMF)-28 with heterodyne detection based on DSP and erbium-doped fiber amplifier (EDFA)-only amplification. Although the required analog bandwidth and sampling speed of the PDs and ADCs are significantly increased for heterodyne detection, the benefits from the simplified coherent receiver architecture and effective DSP in digital frequency domain are experimentally demonstrated.

  2. All-VCSEL based digital coherent detection link for multi Gbit/s WDM passive optical networks.

    Science.gov (United States)

    Rodes, Roberto; Jensen, Jesper Bevensee; Zibar, Darko; Neumeyr, Christian; Roenneberg, Enno; Rosskopf, Juergen; Ortsiefer, Markus; Monroy, Idelfonso Tafur

    2010-11-22

    We report on experimental demonstration of a digital coherent detection link fully based on vertical cavity surface emitting lasers (VCSELs) for the transmitter as well as for the local oscillator light source at the receiver side. We demonstrate operation at 5 Gbps at a 1550 nm wavelength with record receiver sensitivity of -36 dBm after transmission over 40 km standard single mode fiber. Digital signal processing compensates for frequency offset between the transmitter and the local oscillator VCSELs, and for chromatic dispersion. This system allows for uncooled VCSEL operation and fully passive fiber transmission with no use of optical amplification or optical dispersion compensation. The proposed system demonstrates the potential of multi-gigabit coherent passive optical networks with extended reach and increased capacity. Moreover, this is, to the best of our knowledge, the first demonstration of coherent optical transmission systems using a low-cost VCSEL as the local oscillator as well as for the transmitter.

  3. All-VCSEL based digital coherent detection link for multi Gbit/s WDM passive optical networks

    DEFF Research Database (Denmark)

    Rodes Lopez, Roberto; Jensen, Jesper Bevensee; Zibar, Darko

    2010-01-01

    We report on experimental demonstration of a digital coherent detection link fully based on vertical cavity surface emitting lasers (VCSELs) for the transmitter as well as for the local oscillator light source at the receiver side. We demonstrate operation at 5 Gbps at a 1550 nm wavelength...... with record receiver sensitivity of -36 dBm after transmission over 40 km standard single mode fiber. Digital signal processing compensates for frequency offset between the transmitter and the local oscillator VCSELs, and for chromatic dispersion. This system allows for uncooled VCSEL operation and fully...

  4. Local food:

    DEFF Research Database (Denmark)

    Sundbo, Donna Isabella Caroline

    2013-01-01

    Recently there has been more focus on food in general and local food in particular. But what is local food? And what are the perceptions of this concept according to theory and to providers and consumers of local food? This article first summarises and compares three different theoretical perspec...... the providers and consumers studied on what local food is. However, this may change in time.......Recently there has been more focus on food in general and local food in particular. But what is local food? And what are the perceptions of this concept according to theory and to providers and consumers of local food? This article first summarises and compares three different theoretical...... perspectives on local food, namely experience economy, local food systems and what is termed pro-industrialism. These have differing and sometimes opposite conceptualisations and aims for the concept of local food. Using the perspective of experience economy as theoretical background, the concept of local food...

  5. Local Content

    CSIR Research Space (South Africa)

    Gibberd, Jeremy

    2016-10-01

    Full Text Available is also delineated in order to demonstrate the implications of local content on building design, construction and operation. The advantages and disadvantages of local content approaches are discussed and illustrated through examples. Finally, broad...

  6. Local complications

    NARCIS (Netherlands)

    van den Akker, H.P.; Baart, J.A.; Baart, J.A.; Brand, H.S.

    2017-01-01

    Local anaesthesia is frequently used in dentistry and seldom leads to serious local complications. Nevertheless, it is of great importance to be aware of the causes of each local complication and – if necessary – implement correct treatment. The patient must be informed extensively and, if

  7. Local Helioseismology

    Directory of Open Access Journals (Sweden)

    Gizon Laurent

    2005-11-01

    Full Text Available We review the current status of local helioseismology, covering both theoretical and observational results. After a brief introduction to solar oscillations and wave propagation through inhomogeneous media, we describe the main techniques of local helioseismology: Fourier-Hankel decomposition, ring-diagram analysis, time-distance helioseismology, helioseismic holography, and direct modeling. We discuss local helioseismology of large-scale flows, the solar-cycle dependence of these flows, perturbations associated with regions of magnetic activity, and solar supergranulation.

  8. Localized Scleroderma

    Science.gov (United States)

    ... scleroderma, or who are experts at examining the skin, can arrive at the diagnosis without much difficulty after a careful examination. In ... especially in patients who continue to have active skin problems or develop new ... Diagnosis of Localized Scleroderma? The diagnosis of localized scleroderma ...

  9. Net Locality

    DEFF Research Database (Denmark)

    de Souza e Silva, Adriana Araujo; Gordon, Eric

    Provides an introduction to the new theory of Net Locality and the profound effect on individuals and societies when everything is located or locatable. Describes net locality as an emerging form of location awareness central to all aspects of digital media, from mobile phones, to Google Maps...... of emerging technologies, from GeoCities to GPS, Wi-Fi, Wiki Me, and Google Android....

  10. Implementation of a cost-effective optical comb source in a WDM-PON with 10.7 Gb/s data to each ONU and 50 km reach.

    Science.gov (United States)

    Maher, Robert; Shi, Kai; Barry, Liam P; O'Carroll, John; Kelly, B; Phelan, R; O'Gorman, J; Anandarajah, Prince M

    2010-07-19

    The performance of a cost-effective optical comb source using commercial off the shelf (COTS) components in a WDM passive optical network is demonstrated. Eight comb modes are individually modulated at 10.7 Gb/s and transmitted over 50 km of single mode fiber for downlink transmission. Error free performance is obtained for each comb line and a maximum performance difference of 1.4 dB is experienced between the eight channels. Colorless operation of the optical network unit is achieved by utilizing an integrated module consisting of a tunable laser and an electro-absorption modulator as an uplink transmitter. Finally the predicted downstream performance of the system, when all the channels are transmitted simultaneously, is numerically simulated.

  11. Modelo de asignación predictivo de longitudes de ondas en redes WDM teniendo en cuenta dispersión residual y tráficos unicast/multicast con QoS

    Directory of Open Access Journals (Sweden)

    Javier Sierra

    2009-01-01

    Full Text Available El tráfico de Internet está en constante crecimiento y con él las aplicaciones del tipo unicast/multicast con diferentes requerimientos de Calidad de Servicio (QoS. Esto es motivo para que las Redes de Transporte Ópticas (OTN deban continuar su evolución hacia redes completamente ópticas (sin conversiones Óptico-Electrónico-Óptico: OEO. S/G Light-tree es una arquitectura de los nodos de las redes all-OTN que permite el optimo enrutamiento y/o manejo de tráficos unicast/multicast empleando el concepto de Traffic Grooming (TG, granularidad de tráfico en un ambiente óptico. Las técnicas de grooming así como los algoritmos de asignación y enrutamiento propuestos hasta el momento no tienen en cuenta los fenómenos que se pueden prestar en la fibra óptica, los cuales atenúan o alteran las diferentes longitudes de onda en las redes WDM (Wavelength Division Multiplexing. La dispersión cromática es un fenómeno que deforma los pulsos transmitidos en una fibra óptica y el efecto depende de la longitud de onda empleada en la transmisión. En este artículo, se propone un modelo predictivo de asignación de longitudes de ondas basado en cadenas de Markov que tiene en cuenta la dispersión residual en redes WDM que soportan traffic grooming y tráficos unicast/multicast con requerimientos de QoS. Los resultados de las simulaciones realizadas muestran que el modelo propuesto mejora la probabilidad de bloqueo de tráficos con requerimientos de QoS.

  12. Local Foods, Local Places Toolkit

    Science.gov (United States)

    Toolkit to help communities that want to use local foods to spur revitalization. The toolkit gives step-by-step instructions to help communities plan and host a workshop and create an action plan to implement.

  13. Locals Collection

    Directory of Open Access Journals (Sweden)

    Stephen Hastings-King

    2010-03-01

    Full Text Available A locals collection is a set of parameters that are used to delimit data-mining operations. This piece uses a collection of locals from around Essex Massachusetts to shape and delimit an interrogation of post-reality in contemporary America. It explores the notion of crisis, the possibility of a crisis of empire that may or may not emerge in a media-space that does not allow crisis of empire to be mentioned and relations this maybe-crisis to the various levels of economic dysfunction that have become evident since late 2008. But mostly this piece explores ways in which particular stories about particular people do and do not link/link to these larger-scale narratives. This is the first of a potential series of locals collections that will mine the American post-real.

  14. Desarrollo local

    Directory of Open Access Journals (Sweden)

    Luciano Palmitesta

    2001-12-01

    Full Text Available Tras explicar la génesis del concepto de desarrollo y a quien se le aplica la necesidad de desarrollarse, el autor de este ensayo hace un recorrido por las escuelas más representativas de pensamiento sobre el tema. A continuación, entra a reflexionar el concepto de lo local y de sociedad local y sus elementos. En la segunda parte, se analiza la Economía Local y se hace un intento de aplicar esta teoría a la realidad nicaragüense. En esta parte se examinan las diferentes formas empresariales más comunes en Nicaragua. Igualmente, se estudian las dificultades y ventajas de este tipo de empresas en un mundo globalizado y se plantean algunos posibles mecanismos para afrontar los problemas. El trabajo cierra con algunas breves conclusiones.

  15. Gender & WDM in MENA region

    International Development Research Centre (IDRC) Digital Library (Canada)

    nkhaled

    WaDImena) is funded and coordinated by the International Development Research Centre1 (IDRC), with financial support from the. International Fund for Agricultural Development2 (IFAD) and the Canadian International Development. Agency3 ...

  16. Transmission analysis in WDM networks

    DEFF Research Database (Denmark)

    Rasmussen, Christian Jørgen

    1999-01-01

    This thesis describes the development of a computer-based simulator for transmission analysis in optical wavelength division multiplexing networks. A great part of the work concerns fundamental optical network simulator issues. Among these issues are identification of the versatility and user......-friendliness demands which such a simulator must meet, development of the "spectral window representation" for representation of the optical signals and finding an effective way of handling the optical signals in the computer memory. One important issue more is the rules for the determination of the order in which...... the different component models are invoked during the simulation of a system. A simple set of rules which makes it possible to simulate any network architectures is laid down. The modelling of the nonlinear fibre and the optical receiver is also treated. The work on the fibre concerns the numerical solution...

  17. Localized shocks

    Energy Technology Data Exchange (ETDEWEB)

    Roberts, Daniel A. [Center for Theoretical Physics and Department of Physics,Massachusetts Institute of Technology, Cambridge, MA (United States); Stanford, Douglas [Stanford Institute for Theoretical Physics and Department of Physics,Stanford University, Stanford, CA (United States); School of Natural Sciences, Institute for Advanced Study,Princeton, NJ (United States); Susskind, Leonard [Stanford Institute for Theoretical Physics and Department of Physics,Stanford University, Stanford, CA (United States)

    2015-03-10

    We study products of precursors of spatially local operators, W{sub x{sub n}}(t{sub n})…W{sub x{sub 1}}(t{sub 1}), where W{sub x}(t)=e{sup −iHt}W{sub x}e{sup iHt}. Using chaotic spin-chain numerics and gauge/gravity duality, we show that a single precursor fills a spatial region that grows linearly in t. In a lattice system, products of such operators can be represented using tensor networks. In gauge/gravity duality, they are related to Einstein-Rosen bridges supported by localized shock waves. We find a geometrical correspondence between these two descriptions, generalizing earlier work in the spatially homogeneous case.

  18. Localized shocks

    OpenAIRE

    Stanford, Douglas; Susskind, Leonard; Roberts, Daniel Adam

    2014-01-01

    We study products of precursors of spatially local operators, W[subscript xn](tn)⋅⋅⋅W[subscript x1](t[subscript 1]), where W [subscript x] (t) = e [superscript − iHt] W [subscript x] e [superscript iHt]. Using chaotic spin-chain numerics and gauge/gravity duality, we show that a single precursor fills a spatial region that grows linearly in t. In a lattice system, products of such operators can be represented using tensor networks. In gauge/gravity duality, they are related to Einstein-Rosen ...

  19. Demonstration of 575-Mb/s downlink and 225-Mb/s uplink bi-directional SCM-WDM visible light communication using RGB LED and phosphor-based LED.

    Science.gov (United States)

    Wang, Yuanquan; Wang, Yiguang; Chi, Nan; Yu, Jianjun; Shang, Huiliang

    2013-01-14

    We propose and experimentally demonstrate a novel full-duplex bi-directional subcarrier multiplexing (SCM)-wavelength division multiplexing (WDM) visible light communication (VLC) system based on commercially available red-green-blue (RGB) light emitting diode (LED) and phosphor-based LED (P-LED) with 575-Mb/s downstream and 225-Mb/s upstream transmission, employing various modulation orders of quadrature amplitude modulation (QAM) orthogonal frequency division multiplexing (OFDM). For the downlink, red and green colors/wavelengths are assigned to carry useful information, while blue chip is just kept lighting to maintain the white color illumination, and for the uplink, the low-cost P-LED is implemented. In this demonstration, pre-equalization and post-equalization are also adopted to compensate the severe frequency response of LEDs. Using this scheme, 4-user downlink and 1-user uplink transmission can be achieved. Furthermore, it can support more users by adjusting the bandwidth of each sub-channel. Bit error rates (BERs) of all links are below pre-forward-error-correction (pre-FEC) threshold of 3.8x 10(-3) after 66-cm free-space delivery. The results show that this scheme has great potential in the practical VLC system.

  20. Quantum Locality?

    Energy Technology Data Exchange (ETDEWEB)

    Stapp, Henry

    2011-11-10

    vagaries that he cites do not upset the proof in question. It is show here in detail why the precise statement of this theorem justifies the specified application of CQT. It is also shown, in response to his challenge, why a putative proof of locality that he has proposed is not valid.

  1. Off ramp : a secondary school TDM program

    Energy Technology Data Exchange (ETDEWEB)

    Haq, F. [Better Environmentally Sound Transportation (BEST), Vancouver, BC (Canada)

    2002-07-01

    The cities of Vancouver and Victoria in British Columbia have implemented a high school vehicle trip reduction program entitled Off-Ramp. The program, created by BEST, is about youth empowerment to help youths lead their peers to walk, cycle, skateboard, in-line skate, or carpool to school for a sustainable environment. Students raise awareness through media and drama to counter pop images of driving as being cool. Sponsorship is very important to the success of the program.

  2. A novel wavelength reused bidirectional RoF-WDM-PON architecture to mitigate reflection and Rayleigh backscattered noise in multi-Gb/s m-QAM OFDM SSB upstream and downstream transmission over a single fiber

    Science.gov (United States)

    Patel, Dhananjay; Dalal, U. D.

    2017-05-01

    A novel m-QAM Orthogonal Frequency Division Multiplexing (OFDM) Single Sideband (SSB) architecture is proposed for centralized light source (CLS) bidirectional Radio over Fiber (RoF) - Wavelength Division Multiplexing (WDM) - Passive Optical Network (PON). In bidirectional transmission with carrier reuse over the single fiber, the Rayleigh Backscattering (RB) noise and reflection (RE) interferences from optical components can seriously deteriorate the transmission performance of the fiber optic systems. These interferometric noises can be mitigated by utilizing the optical modulation schemes at the Optical Line Terminal (OLT) and Optical Network Unit (ONU) such that the spectral overlap between the optical data spectrum and the RB and RE noise is minimum. A mathematical model is developed for the proposed architecture to accurately measure the performance of the transmission system and also to analyze the effect of interferometric noise caused by the RB and RE. The model takes into the account the different modulation schemes employed at the OLT and the ONU using a Mach Zehnder Modulator (MZM), the optical launch power and the bit-rates of the downstream and upstream signals, the gain of the amplifiers at the OLT and the ONU, the RB-RE noise, chromatic dispersion of the single mode fiber and optical filter responses. In addition, the model analyzes all the components of the RB-RE noise such as carrier RB, signal RB, carrier RE and signal RE, thus providing the complete representation of all the physical phenomena involved. An optical m-QAM OFDM SSB signal acts as a test signal to validate the model which provides excellent agreement with simulation results. The SSB modulation technique using the MZM at the OLT and the ONU differs in the data transmission technique that takes place through the first-order higher and the lower optical sideband respectively. This spectral gap between the downstream and upstream signals reduces the effect of Rayleigh backscattering and

  3. Diagnosis and evaluation of the treatment by PET-T.D.M. with 18 F.D.G. of the digestive origin of an infectious endocarditis complicated with stroke (C.V.A.); Diagnostic et evaluation du traitement, par la TEP-TDM au 18 FDG, de l'origine digestive d'une endocardite infectieuse compliquee d'AVC

    Energy Technology Data Exchange (ETDEWEB)

    Tessonnier, L.; Guedj, E.; Mundler, O. [Service central de medecine nucleaire, CHU de La-Timone, Marseille, (France); Maurel, B. [c service deneuroradiologie, CHU de La-Timone, Marseille, (France); Habib, G. [service de cardiologie, CHU de La-Timone, Marseille, (France); Nicoli, F. [service de neurologie, CHU de La-Timone, Marseille, (France)

    2009-05-15

    (We report the case of a seventeen years old patient sent for an etiological evaluation of an endocarditis, complicated with a cerebral vascular accident, for who the results of conventional imaging examinations were negative. The PET T.D.M. with {sup 18}F.D.G. was realized for the detection of a front door. Effectively, this examination allowed to find a digestive front door in the frame of an infectious endocarditis and direct the complementary adequate explorations. The following of studies will allow to give correctly the contribution of the PET-T.D.M. in infectious and inflammatory pathologies, whether it is in terms of diagnosis, of extension assessment or therapeutic evaluation. (N.C.)

  4. Local duality for 2-dimensional local ring

    Indian Academy of Sciences (India)

    We prove a local duality for some schemes associated to a 2-dimensional complete local ring whose residue field is an -dimensional local field in the sense of Kato–Parshin. Our results generalize the Saito works in the case =0 and are applied to study the Bloch–Ogus complex for such rings in various cases.

  5. VT Certified Local Governments

    Data.gov (United States)

    Vermont Center for Geographic Information — Vermont established its Certified Local Government (CLG) program in 1985 to better help local governments integrate historic preservation concerns with planning and...

  6. Local food and tourism

    DEFF Research Database (Denmark)

    Boesen, Morten; Sundbo, Donna; Sundbo, Jon

    2017-01-01

    is on the actions and attitude logics of local food networks and tourism actors, and whether their respective logics fit as a factor to explain why or why not development of local food concepts lead to increased local tourism. Six local food networks and their collaboration with local tourism actors are studied......This article investigates the question: Why local food networks succeed or fail in collaborating with local tourism actors to create more tourism based on local food? The article focuses on entrepreneurial local food networks and their collaboration with local tourism actors. Emphasis......, which emphasises the community aspect (i.e. that both parties want to support the local community and brand it). The non-fitting logics that mostly hinder this are dominant market and industry logic, which emphasise egoistic economic gain....

  7. Locally orderless registration

    DEFF Research Database (Denmark)

    Darkner, Sune; Sporring, Jon

    2013-01-01

    approach is based on local intensity histograms and built upon the technique of Locally Orderless Images. Histograms by Locally Orderless Images are well posed and offer explicit control over the 3 inherent and unavoidable scales: the spatial resolution, intensity levels, and spatial extent of local...

  8. Local duality for 2-dimensional local ring

    Indian Academy of Sciences (India)

    dimensional complete local ring whose residue field is an n-dimensional local field in the sense of. Kato–Parshin. Our results generalize the Saito works in the case n = 0 and are applied to study the Bloch–Ogus complex for such rings in various cases.

  9. carcinomes nasopharynges localement avances locally advanced ...

    African Journals Online (AJOL)

    East Asia and North Africa. The prognosis remains poor for locally advanced stages (IIB -IVB), more than one third of cases presented locally recurrent and ..... Lee A.W.M, Poon Y.F, Foo W et al. Retrospective analysis of 5 037 patients with nasopharyngeal carcinoma treated during 1976-85: ove- rall survival and patterns of ...

  10. Wavelength division multiplexed local area networks

    Science.gov (United States)

    Kazovsky, L. G.; Barry, C.; Hickey, M.; Noronha, C.; Poggiolini, P.

    The advent of new services, such as multimedia communications, high-volume file transfer, high-definition image transmission, video/audio retrieval, and others, has created a need for high speed data networks. Future networks are expected to support, in an integrated fashion, services with highly diverse traffic requirements. Due to the high data rates involved, such networks will use optical fiber as the transmission medium. It has been recognized that current network topologies, employing single shared channels to provide connectivity between the nodes, are not adequate to provide these new services, thus, creating the need for multichannel networks. One way to realize multiple channels on the optical fiber is through the use of Wavelength-Division Multiplexing (WDM); this method has the additional advantage that, by employing tunable transmitters and/or receivers, the network topology can change dynamically in time. This paper focuses on WDM Networks. Following a discussion of the possible network topologies, we investigate the technological issues related to the implementation of such topologies, and describe some experimental implementations reported in the literature.

  11. Defining local food

    DEFF Research Database (Denmark)

    Eriksen, Safania Normann

    2013-01-01

    Despite evolving local food research, there is no consistent definition of “local food.” Various understandings are utilized, which have resulted in a diverse landscape of meaning. The main purpose of this paper is to examine how researchers within the local food systems literature define local...... food, and how these definitions can be used as a starting point to identify a new taxonomy of local food based on three domains of proximity....

  12. Locally analytic vectors in representations of locally

    CERN Document Server

    Emerton, Matthew J

    2017-01-01

    The goal of this memoir is to provide the foundations for the locally analytic representation theory that is required in three of the author's other papers on this topic. In the course of writing those papers the author found it useful to adopt a particular point of view on locally analytic representation theory: namely, regarding a locally analytic representation as being the inductive limit of its subspaces of analytic vectors (of various "radii of analyticity"). The author uses the analysis of these subspaces as one of the basic tools in his study of such representations. Thus in this memoir he presents a development of locally analytic representation theory built around this point of view. The author has made a deliberate effort to keep the exposition reasonably self-contained and hopes that this will be of some benefit to the reader.

  13. How local is the local field potential?

    Science.gov (United States)

    Kajikawa, Yoshinao; Schroeder, Charles E

    2011-12-08

    Local field potentials (LFPs) are of growing importance in neurophysiological investigations. LFPs supplement action potential recordings by indexing activity relevant to EEG, magnetoencephalographic, and hemodynamic (fMRI) signals. Recent reports suggest that LFPs reflect activity within very small domains of several hundred micrometers. We examined this conclusion by comparing LFP, current source density (CSD), and multiunit activity (MUA) signals in macaque auditory cortex. Estimated by frequency tuning bandwidths, these signals' "listening areas" differ systematically with an order of MUA local contributions. Direct measurements indicate passive spread of LFPs to sites more than a centimeter from their origins. These findings appear to be independent of the frequency content of the LFP. Our results challenge the idea that LFP recordings typically integrate over extremely circumscribed local domains. Rather, LFPs appear as a mixture of local potentials with "volume conducted" potentials from distant sites. Copyright © 2011 Elsevier Inc. All rights reserved.

  14. An improved and fully implicit multi-group non-local electron transport model and its validations

    Science.gov (United States)

    Sijoy, C. D.; Mishra, V.; Chaurasia, S.

    2017-09-01

    The combined effect of thermal flux inhibition and non-local electron heat flux in the radiation hydrodynamics (RHD) simulation of laser-driven systems can be accurately predicted by using non-local electron transport (NLET) models. These models can avoid commonly used space and time-independent ad-hoc flux-limiting procedures. However, the use of classical electron collision frequency in these models is rigorously valid for high temperature non-degenerate plasmas. In laser-driven systems, the electron thermal energy transport is important in regions between the critical density and ablation surface where the plasma is partially degenerate. Therefore, an improved model for electron collision frequency in this regime is required to accurately predict the thermal energy transport. Previously, we have reported an improved single group non-local electron transport model by using a wide-range electron collision frequency model valid from warm-dense matter (WDM) to fully ionized plasmas. In this work, we have extended this idea into a two-dimensional multi-group non-local electron transport (MG-NLET) model. Moreover, we have used a fully implicit numerical integration scheme in which the models for multi-group thermal radiation transport, laser absorption, electron-ion thermal energy relaxation and ion heat conduction are included in a single step. The performance of this improved MG-NLET model has been assessed by comparing the simulated foil trajectories with the reported experimental data for laser-driven plastic foils. The results indicate that the improved model yields results that are in better agreement with the experimental data.

  15. Clarifying local integration

    Directory of Open Access Journals (Sweden)

    Sarah Meyer

    2006-08-01

    Full Text Available Ana Low’s article in FMR 251 highlights the need to reexamineand re-invigorate debate on local integration as adurable solution for refugees. However, the Self-RelianceStrategy (SRS in Uganda which she describes does notprovide an adequate model of local integration as adurable solution – in fact, local integration is not its aim.

  16. Disorder-Free Localization

    Science.gov (United States)

    Smith, A.; Knolle, J.; Kovrizhin, D. L.; Moessner, R.

    2017-06-01

    The venerable phenomena of Anderson localization, along with the much more recent many-body localization, both depend crucially on the presence of disorder. The latter enters either in the form of quenched disorder in the parameters of the Hamiltonian, or through a special choice of a disordered initial state. Here, we present a model with localization arising in a very simple, completely translationally invariant quantum model, with only local interactions between spins and fermions. By identifying an extensive set of conserved quantities, we show that the system generates purely dynamically its own disorder, which gives rise to localization of fermionic degrees of freedom. Our work gives an answer to a decades old question whether quenched disorder is a necessary condition for localization. It also offers new insights into the physics of many-body localization, lattice gauge theories, and quantum disentangled liquids.

  17. Aging in Sweden: local variation, local control.

    Science.gov (United States)

    Davey, Adam; Malmberg, Bo; Sundström, Gerdt

    2014-08-01

    Aging in Sweden has been uniquely shaped by its history-most notably the long tradition of locally controlled services for older adults. We considered how local variations and local control shape the experience of aging in Sweden and organized the paper into 3 sections. First, we examine aging in Sweden along demography, economy, and housing. Next, we trace the origins and development of the Swedish welfare state to consider formal supports (service provision) and informal supports (caregiving and receipt of care). Finally, we direct researchers to additional data resources for understanding aging in Sweden in greater depth. Sweden was one of the first countries to experience rapid population aging. Quality of life for a majority of older Swedes is high. Local control permits a flexible and adaptive set of services and programs, where emphasis is placed on improving the quality and targeting of services that have already reached a plateau as a function of population and expenditures. © The Author 2013. Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  18. Active plasmonics in WDM traffic switching applications

    DEFF Research Database (Denmark)

    Papaioannou, S.; Kalavrouziotis, D.; Vyrsokinos, K.

    2012-01-01

    . The first active Dielectric-Loaded Surface Plasmon Polariton (DLSPP) thermo-optic (TO) switches with successful performance in single-channel 10 Gb/s data traffic environments have led the inroad towards bringing low-power active plasmonics in practical traffic applications. In this article, we introduce...

  19. WDM Question and Answers | IDRC - International Development ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    2011-01-04

    Jan 4, 2011 ... It seeks to improve water-use efficiency, equity and sustainability through a series of applied research and pilot projects, capacity development, policy dialogue and knowledge networking with strong regional anchorage and ownership. WaDImena operates in many countries and in English, French and ...

  20. WDM Research Series: Working Paper No. 2

    International Development Research Centre (IDRC) Digital Library (Canada)

    IDRC CRDI

    resource management (sustainability, food security, conflict resolution) in leading to, and reinforcing, poverty. ... reforms within a highly centralized water sector to decentralize authority, provide technical information, guidance ..... conservation signals to farmers and shifting the focus of irrigation management to ensure user.

  1. Photonic quasicrystals for application in WDM systems

    DEFF Research Database (Denmark)

    Romero-Vivas, J.; Chigrin, D. N.; Lavrinenko, Andrei

    2005-01-01

    Photonic quasicrystals can possess an isotropic (complete) photonic bandgap even in the case of low refractive indices of the constitutive materials, which makes them atrractive optical materials with important technological applications. In this work, several aspects related to the design of wav...

  2. WDM networking on a European Scale

    DEFF Research Database (Denmark)

    Parnis, Noel; Limal, Emmanuel; Hjelme, Dag R.

    1998-01-01

    Four different topological approaches to designing a pan-European optical network are discussed. For such an ultra-high capacity large-scale network, it is necessary to overcome physical path length limitations and to limit Optical Cross-Connect (OXC) complexity.......Four different topological approaches to designing a pan-European optical network are discussed. For such an ultra-high capacity large-scale network, it is necessary to overcome physical path length limitations and to limit Optical Cross-Connect (OXC) complexity....

  3. WDM Questions and Answers-Eng

    International Development Research Centre (IDRC) Digital Library (Canada)

    rsamir

    Farmers tend to over-irrigate, pipes tend to leak, taps tend to drip and little is done to prevent water pollution. Fourth: Water is the right of all people: rich and poor, men and women, small farmers and large farmers, etc.. Without explicit responsive policy based on scientific evidence that actively ensures everyone's rights to ...

  4. [Local anaesthesia in ruminants].

    Science.gov (United States)

    Nuss, Karl; Schwarz, Andrea; Ringer, Simone

    2017-06-20

    The use of local anaesthesia in ruminants allows many surgical procedures to be conducted free of pain, efficiently and inexpensively in the field. Local anaesthesia combined with sedation and immobilisation of the animal can replace general anaesthesia for many procedures (e. g. castration, claw amputation). The level of difficulty differs among various local anaesthetic techniques: local infiltration of tissue or anaesthesia of the cornual nerve are easily performed, whereas local anaesthesia of the eye, regional anaesthesia in limbs or anaesthesia for umbilical surgery are more difficult to carry out. This article presents an illustrated overview of the most common local anaesthetic procedures in cattle as well as in small ruminants and serves as a practical guide for veterinarians in the field. In principle, these techniques can likewise be applied in other ruminants or artiodactyls.

  5. Local Worlds of Activation

    DEFF Research Database (Denmark)

    Jacobsson, Kerstin; Hollertz, Katarina; Garsten, Christina

    2017-01-01

    . This article studies local activation policy and practice in three Swedish municipalities, representing three distinct ‘local worlds of activation’. The analysis shows that policy orientations in the municipalities studied ranged from ‘work-first’ to ‘life-first’ approaches to activation. Governance...... of Coordination Unions, as multi-party collaborate organisational structures established for activation policy implementation for certain target groups. Thus, activation must be approached not as a fixed and universal policy for social inclusion, but as susceptible to local practice and hence open to influence...... from local politics, established local traditions, patterns of networking and modes of collaborating, as the notion of ‘local words of activation’ intends to capture....

  6. Local Social Networks

    OpenAIRE

    Sapuppo, Antonio; Sørensen, Lene Tolstrup

    2011-01-01

    Online social networks have become essential for many users in their daily communication. Through a combination of the online social networks with opportunistic networks, a new concept arises: Local Social Networks. The target of local social networks is to promote social networking benefits in physical environment in order to leverage personal affinities in the users' surroundings. The purpose of this paper is to present and discuss the concept of local social networks as a new social commun...

  7. Local Social Networks

    DEFF Research Database (Denmark)

    Sapuppo, Antonio; Sørensen, Lene Tolstrup

    2011-01-01

    in physical environment in order to leverage personal affinities in the users' surroundings. The purpose of this paper is to present and discuss the concept of local social networks as a new social communication system. Particularly, the preliminary architecture and the prototype of local social networks......Online social networks have become essential for many users in their daily communication. Through a combination of the online social networks with opportunistic networks, a new concept arises: Local Social Networks. The target of local social networks is to promote social networking benefits...

  8. Local Democracy in Myanmar

    DEFF Research Database (Denmark)

    Kyed, Helene Maria; Harrisson, Annika Pohl; McCarthy, Gerard

    local elections of village tract and urban ward administrators and reflects on the future of local democracy and decentralization in Myanmar. Local administrators are the primary point of contact between the state and citizens. How they are elected and how they govern in the everyday are essential....... However, often overlooked in this larger picture of transition is the state of local democracy, including village level governance and everyday state-citizen engagements. Political changes at this level are equally crucial for the wider democratization process. This roundtable summary discusses the 2016...

  9. Localization of magnetic pills

    Science.gov (United States)

    Laulicht, Bryan; Gidmark, Nicholas J.; Tripathi, Anubhav; Mathiowitz, Edith

    2011-01-01

    Numerous therapeutics demonstrate optimal absorption or activity at specific sites in the gastrointestinal (GI) tract. Yet, safe, effective pill retention within a desired region of the GI remains an elusive goal. We report a safe, effective method for localizing magnetic pills. To ensure safety and efficacy, we monitor and regulate attractive forces between a magnetic pill and an external magnet, while visualizing internal dose motion in real time using biplanar videofluoroscopy. Real-time monitoring yields direct visual confirmation of localization completely noninvasively, providing a platform for investigating the therapeutic benefits imparted by localized oral delivery of new and existing drugs. Additionally, we report the in vitro measurements and calculations that enabled prediction of successful magnetic localization in the rat small intestines for 12 h. The designed system for predicting and achieving successful magnetic localization can readily be applied to any area of the GI tract within any species, including humans. The described system represents a significant step forward in the ability to localize magnetic pills safely and effectively anywhere within the GI tract. What our magnetic pill localization strategy adds to the state of the art, if used as an oral drug delivery system, is the ability to monitor the force exerted by the pill on the tissue and to locate the magnetic pill within the test subject all in real time. This advance ensures both safety and efficacy of magnetic localization during the potential oral administration of any magnetic pill-based delivery system. PMID:21257903

  10. Localization of Interference Fringes.

    Science.gov (United States)

    Simon, J. M.; Comastri, Silvia A.

    1980-01-01

    Discusses a proof for determining the localized fringes position arrived at when one considers the interference of two extended sources when one is able to observe fringes only at certain points in space. Shows how the localized fringes may be found in a device used to observe Newton's rings. (Author/CS)

  11. Local Exhaust Ventilation

    DEFF Research Database (Denmark)

    Madsen, Ulla; Breum, N. O.; Nielsen, Peter V.

    Capture efficiency of a local exhaust system, e.g. a kitchen hood, should include only contaminants being direct captured. In this study basic concepts of local exhaust capture efficiency are given, based on the idea of a control box. A validated numerical model is used for estimation...

  12. Local anesthesia in dentistry

    National Research Council Canada - National Science Library

    Bahl, Ritu

    2004-01-01

    ... upon achieving adequate local anesthesia. Research has shown that the fear of pain associated with dentistry is closely associated with the most common method for blocking pain during dental procedures-intraoral administration of local anesthetics. This is considered aversive due to the pain associated with the injection and the perceived threat ...

  13. Locally orderless registration code

    DEFF Research Database (Denmark)

    2012-01-01

    This is code for the TPAMI paper "Locally Orderless Registration". The code requires intel threadding building blocks installed and is provided for 64 bit on mac, linux and windows.......This is code for the TPAMI paper "Locally Orderless Registration". The code requires intel threadding building blocks installed and is provided for 64 bit on mac, linux and windows....

  14. Time to Go Local!

    Science.gov (United States)

    ... example, a person who has found information about breast cancer on MedlinePlus would be able to click on GoLocal and be instantly connected to information about local screening services, cancer care facilities, support groups, exercise and yoga classes, providers of wigs ...

  15. Clustering by Local Gravitation.

    Science.gov (United States)

    Wang, Zhiqiang; Yu, Zhiwen; Chen, C L Philip; You, Jane; Gu, Tianlong; Wong, Hau-San; Zhang, Jun

    2017-05-02

    The objective of cluster analysis is to partition a set of data points into several groups based on a suitable distance measure. We first propose a model called local gravitation among data points. In this model, each data point is viewed as an object with mass, and associated with a local resultant force (LRF) generated by its neighbors. The motivation of this paper is that there exist distinct differences between the LRFs (including magnitudes and directions) of the data points close to the cluster centers and at the boundary of the clusters. To capture these differences efficiently, two new local measures named centrality and coordination are further investigated. Based on empirical observations, two new clustering methods called local gravitation clustering and communication with local agents are designed, and several test cases are conducted to verify their effectiveness. The experiments on synthetic data sets and real-world data sets indicate that both clustering approaches achieve good performance on most of the data sets.

  16. Local sleep and learning.

    Science.gov (United States)

    Huber, Reto; Ghilardi, M Felice; Massimini, Marcello; Tononi, Giulio

    2004-07-01

    Human sleep is a global state whose functions remain unclear. During much of sleep, cortical neurons undergo slow oscillations in membrane potential, which appear in electroencephalograms as slow wave activity (SWA) of sleep. It has been suggested that SWA homeostasis may reflect synaptic changes underlying a cellular need for sleep. If this were so, inducing local synaptic changes should induce local SWA changes, and these should benefit neural function. Here we show that sleep homeostasis indeed has a local component, which can be triggered by a learning task involving specific brain regions. Furthermore, we show that the local increase in SWA after learning correlates with improved performance of the task after sleep. Thus, sleep homeostasis can be induced on a local level and can benefit performance.

  17. Granulomatous reaction to a foreign body mimicking bronchogenic tumor. CT findings with virtual endoscopy; Granulome a corps etranger mimant une tumeur bronchique. Aspects en TDM avec vue par endoscopie virtuelle

    Energy Technology Data Exchange (ETDEWEB)

    Mignon, F.; Chambellan, A.; Duboucher, C.; Dangeard-Chikhani, S.; Leclerc, P.; Lemesle, J. [Centre Hospitalier, 78 - Saint-Germain-en-Laye (France); Mesurolle, B. [Hopital Ambroise-Pare, 92 - Boulogne (France)

    1997-11-01

    The aim of this study is to report the spiral CT findings of an endobronchial foreign body (chicken`s bone) unknown on the postero-anterior chest radiograph and on the first bronchoscopy. The double originality of this case is the association with endobronchial actinomycosis mimicking a bronchial neoplasm and the utilization of virtual endoscopy by endo-luminal 3D reconstruction in this context which has never been reported. The endo-luminal 3D reconstruction of the bronchial tree could help guide the endoscopic procedure by better localization of the lesions. (authors)

  18. Explosion localization via infrasound.

    Science.gov (United States)

    Szuberla, Curt A L; Olson, John V; Arnoult, Kenneth M

    2009-11-01

    Two acoustic source localization techniques were applied to infrasonic data and their relative performance was assessed. The standard approach for low-frequency localization uses an ensemble of small arrays to separately estimate far-field source bearings, resulting in a solution from the various back azimuths. This method was compared to one developed by the authors that treats the smaller subarrays as a single, meta-array. In numerical simulation and a field experiment, the latter technique was found to provide improved localization precision everywhere in the vicinity of a 3-km-aperture meta-array, often by an order of magnitude.

  19. Local Anesthetic Microencapsulation.

    Science.gov (United States)

    1983-11-04

    local anesthetic by Freud and Koller in 1884 (Ritchie and Grune 1980), local anes- thetics have played an important role in clinical medicine. Local...J * ana , NCO C L) ..0C%j U C - r_ c 00 4- C) LU- V~~ 0 )a IrL LUI ii;:7-7 73 -04 &001 EE 4-- 4)4 m’ CJ ou u o 0>’. U L o_ 0 0 -l -L 0 4) U U 0 0 4-L

  20. Contribution of the PET/CT with {sup 18}F.D.G. in the evaluation of rhabdomyosarcomas in pediatrics; Apport de la TEP/TDM au {sup 18}FDG dans l'evaluation des rhabdomyosarcomes en pediatrie

    Energy Technology Data Exchange (ETDEWEB)

    Ricard, F.; Giammarile, F. [Centre hospitalier Lyon-Sud, Pierre-Benite, 69 - Lyon (France); Mognetti, T.; Cimarelli, S. [Centre Leon-Berard, 69 - Lyon (France); Deshayes, E. [Hopital Edouard-Herriot, 69 - Lyon (France)

    2010-07-01

    purpose: evaluate the contribution of PET/CT with {sup 18}F.D.G. in complement of conventional imaging in the initial assessment and the assessment of follow-up of rhabdomyosarcomas in the pediatrics population. Conclusions: the PET/CT with {sup 18}F.D.G. is an efficient technique to evaluate the child rhabdomyosarcomas, in complement of conventional imaging, especially for the bone, osteo-medullary ganglion staging as well as the therapy strategy and the research of the primitive site. We suggest the use of the PET/CT to replace the bone scintigraphy, in complement of local MRI and CT for the initial assessment, the follow-up assessment of pediatrics rhabdomyosarcomas. (N.C.)

  1. Focus on Local Reaction.

    Science.gov (United States)

    Howe, Rod

    1999-01-01

    Discusses how the student newspaper "The Lance" (at Westside High School in Omaha, Nebraska) covered the shootings at Columbine High School. Notes that the staff localized the event and brought the student body into the story. (RS)

  2. Stereotype locally convex spaces

    Energy Technology Data Exchange (ETDEWEB)

    Akbarov, S S

    2000-08-31

    We give complete proofs of some previously announced results in the theory of stereotype (that is, reflexive in the sense of Pontryagin duality) locally convex spaces. These spaces have important applications in topological algebra and functional analysis.

  3. Stereotype locally convex spaces

    Science.gov (United States)

    Akbarov, S. S.

    2000-08-01

    We give complete proofs of some previously announced results in the theory of stereotype (that is, reflexive in the sense of Pontryagin duality) locally convex spaces. These spaces have important applications in topological algebra and functional analysis.

  4. rural y conocimiento local

    Directory of Open Access Journals (Sweden)

    Teresa Acampora

    2007-01-01

    Full Text Available En el contexto de la crisis de los modelos alimentarios en el siglo XXI, las producciones agroalimentarias están en un período de redescubrimiento. Las autoras analizan las principales estrategias que tienen los actores locales para perseguir la valorización de los recursos locales con identidad territorial; para luego ahondar en las políticas de diferenciación de los productos con marcas colectivas certifi-cadas. Finalmente, se ponen en evidencia las relaciones entre productos típicos, conservación de la agrobiodiversidad y conocimientos locales. Aquí se articula el debate sobre valorización de los productos típicos con el debate internacional sobre el conocimiento tradicional y el folclor, que se ha generado a partir de la preocupación internacional sobre la erosión de la biodiversidad y los conocimientos locales.

  5. Characterizing local EMS systems.

    Science.gov (United States)

    2013-08-01

    Emergency medical services (EMS) systems are configured differently depending on several factors, including the size, demographics, geography, and politics of the local communities they serve. Although some information exists about the organization, ...

  6. nuevo gobierno local

    Directory of Open Access Journals (Sweden)

    José Vargas Hernández

    2005-01-01

    Full Text Available Este trabajo tiene como objetivo analizar las funciones y estructura de ingeniería social del nuevo gobierno local para dar respuesta a las demandas sociales, promover el desarrollo y regular los nuevos servicios públicos. A partir de una delimitación de los conceptos de soberanía y autonomía del nuevo gobierno local, se reconfigura una nueva estructura de gobernabilidad de los gobiernos locales que implica una mayor participación ciudadana en los procesos de toma de decisiones y la formulación de las políticas públicas, mediante la facilitación de procesos de descentralización de funciones y mecanismos coordinadores de servicios públicos. Finalmente se analizan las implicaciones en la gobernabilidad de la ingeniería social del nuevo gobierno local.

  7. Local Authority Compensatory Policy

    NARCIS (Netherlands)

    M.C.M. Turkenburg

    1999-01-01

    Original title: Gemeentelijke onderwijsachterstandenbeleid. The introduction in the Netherlands of the Municipal Compensatory Policy (Education) Act on 1 August 1998 made the former educational priority policy a responsibility of local authorities. The intention is that the educational

  8. RNA Localization in Astrocytes

    DEFF Research Database (Denmark)

    Thomsen, Rune

    2012-01-01

    Messenger RNA (mRNA) localization is a mechanism by which polarized cells can regulate protein synthesis to specific subcellular compartments in a spatial and temporal manner, and plays a pivotal role in multiple physiological processes from embryonic development to cell differentiation......, regulation of the blood brain barrier and glial scar tissue formation. Despite the involvement in various CNS functions only a limited number of studies have addressed mRNA localization in astrocytes. This PhD project was initially focused on developing and implementing methods that could be used to asses mRNA...... localization in astrocyte protrusions, and following look into the subcellular localization pattern of specific mRNA species of both primary astrocytes isolated from cortical hemispheres of newborn mice, and the mouse astrocyte cell line, C8S. The Boyden chamber cell fractionation assay was optimized, in a way...

  9. Mining local process models

    OpenAIRE

    Tax, Niek; Sidorova, Natalia; Haakma, Reinder; van der Aalst, Wil M.P.

    2016-01-01

    In this paper we describe a method to discover frequent behavioral patterns in event logs. We express these patterns as \\emph{local process models}. Local process model mining can be positioned in-between process discovery and episode / sequential pattern mining. The technique presented in this paper is able to learn behavioral patterns involving sequential composition, concurrency, choice and loop, like in process mining. However, we do not look at start-to-end models, which distinguishes ou...

  10. On Minds' Localization

    OpenAIRE

    Crocco, Prof M

    2004-01-01

    A confluence of clues from a range of academic topics suggests that minds localization in nature consists of relativistically moving microphysical particles, whose motion is physiologically modulated. Here those clues are shown to imply that the localization of the operations of observers (minds or existentialities) in nature are the actions carriers of a force field, which action carriers are slightly slowed from near-c speed motion by electroneurobiological variations in brain physiology – ...

  11. Local Authority Compensatory Policy

    OpenAIRE

    M.C.M. Turkenburg

    1999-01-01

    Original title: Gemeentelijke onderwijsachterstandenbeleid. The introduction in the Netherlands of the Municipal Compensatory Policy (Education) Act on 1 August 1998 made the former educational priority policy a responsibility of local authorities. The intention is that the educational compensatory policy should be developed and implemented at local level in the coming years in collaboration with school boards. The predominant argument for the decentralisation of the educational compensatory ...

  12. Desempleo y justicia local

    Directory of Open Access Journals (Sweden)

    Elster, Jon

    2003-04-01

    Full Text Available In this paper Jon Elster presents a set of criteria of local justice that regulate dismissals. In situations where work is limited and companies adopt means of employment redundancy, the decision of dismissing certain workers —when this one tries not to be arbitrary— can be based on local criteria of fairness like merit, efficiency, age or other analysed in this work. So, after defining the concept of local justice and presenting some examples, the paper focuses on the importance of the work to organize and structure the life of people. Unemployment has serious consequences for the persons who suffer it and the author advises that it is necessary to subordinate dismissals to criteria of local justice.

    En este artículo se presentan una serie de criterios de justicia local para regular los despidos. En situaciones en las que el trabajo es escaso y las empresas adoptan medidas de regulación de empleo, la decisión de despedir a unos trabajadores o a otros se puede basar, cuando se intenta que no sea arbitraria, en criterios locales de equidad como el mérito, la eficacia, la edad u otros que se analizan en este trabajo. Así, tras definir el concepto de justicia local y presentar algunos ejemplos, el artículo se centra en la importancia del trabajo para organizar y estructurar la vida de la gente. Las graves consecuencias que tiene, por ello, el desempleo para quien lo sufre, aconseja que los despidos se sometan a criterios de justicia local.

  13. Locally Weighted Naive Bayes

    OpenAIRE

    Frank, Eibe; Hall, Mark; Pfahringer, Bernhard

    2012-01-01

    Despite its simplicity, the naive Bayes classifier has surprised machine learning researchers by exhibiting good performance on a variety of learning problems. Encouraged by these results, researchers have looked to overcome naive Bayes primary weakness - attribute independence - and improve the performance of the algorithm. This paper presents a locally weighted version of naive Bayes that relaxes the independence assumption by learning local models at prediction time. Experimental results s...

  14. TOURISM AND LOCAL DEVELOPMENT

    Directory of Open Access Journals (Sweden)

    BORMA AFRODITA

    2015-04-01

    Full Text Available The paper presents a theoretical approach of the relation between tourism and local development. The research method used is based on documenting and summarizing aspects related to the importance of tourism on local development. According to data provided by the World Tourism Organization (WTO, 2014, compared to 2010, a 91% increase of the number of international tourist arrivals is forecasted in 2030, from 948 million arrivals (2010 to 1,810 million arrivals (2030. Therefore, it is no surprise that tourism is viewed as a development strategy in many national economies. Tourism literature captures a series of arguments that emphasize the contribution of tourism to local development by: creating new jobs, revitalizing cultural traditions, improving infrastructure, environmental protection, etc. For Romania, as well, it may be noted that tourism strategies included in the 2013-2016 Government Programme are oriented towards local tourism by: decentralizing the authorization and approval activity, developing an integrated tourism by capitalizing all the local resources (cultural, agricultural, handicraft, etc., connecting Romanian tourism to international trends, etc. In order to achieve the aforementioned objectives, the 2013-2016 Government Program provides the clarification on the issue of decentralization, since the current government believes that a balanced development of Romania can only be achieved through transfer of authority to the local, county and regional levels.

  15. Local Lorentz covariance in finite-dimensional local quantum physics

    Science.gov (United States)

    Raasakka, Matti

    2017-10-01

    We show that local Lorentz covariance arises canonically as the group of transformations between local thermal states in the framework of local quantum physics, given the following three postulates: (i) Local observable algebras are finite-dimensional. (ii) Minimal local observable algebras are isomorphic to M2(C ) , the observable algebra of a single qubit. (iii) The vacuum restricted to any minimal local observable algebra is a nonmaximally mixed thermal state. The derivation reveals a new and surprising relation between spacetime structure and local quantum states. In particular, we show how local restrictions of the vacuum can determine the connection between different local inertial reference frames.

  16. An osteomalacia related to phosphate diabetes - bone scintigraphy with SPECT/CT contribution; Une osteomalacie liee a un diabete phosphore - role de la scintigraphie osseuse couplee a la TEMP-TDM

    Energy Technology Data Exchange (ETDEWEB)

    Ruyer, A.; Granier, P.; Mourad, M. [Centre Hospitalier Antoine-Gayraud, Service de Medecine Nucleaire, 11 - Carcassonne (France)

    2009-12-15

    We report the case of a 59-year-old woman, investigated for disabling pain of the left thigh, unrelated to any traumatic event. Interrogation had found diffuse pain of myalgia-type and arthralgia-type for approximately a year without local inflammatory signs and insufficiency fractures of both calcaneus two years before. The Technetium {sup 99m}-labeled hydroxy-methylene diphosphonate ({sup 99m}Tc-H.D.P.) whole-body bone scintigraphy evidenced multiple hot spots on the higher third of left femur, rib cage, sternum, scapula, pelvis, right hip and both calcaneus. Moreover, a more diffuse and heterogeneous prominent uptake appeared on rib cage, spine and pelvis. These images suggested a diffuse metastatic disease of the skeleton. The single photon emission computerized tomography guided by computerized tomography (SPECT/CT), centered on lumbar spine, pelvis and the upper end of femurs showed that the multiple hot spots were in fact bone fractures. These findings pointed diagnosis to a metabolic disease. The clinical context was in favour of an osteomalacia. Further explorations showed an osteomalacia related to phosphate diabetes. A thorough work-up did not reveal any known aetiology. To date, idiopathic phosphate diabetes seems the most likely diagnosis. Nuclear medicine input in osteomalacia is discussed. (authors)

  17. Beyond local climate

    DEFF Research Database (Denmark)

    D'haen, Sarah Ann Lise; Nielsen, Jonas Østergaard; Lambin, Eric F.

    2014-01-01

    as a safety net against adverse local rainfall events. Results show that household decisions to participate in the nonfarm economy could not be directly linked with local rainfall events during the study period in the mid-2000s. However, household participation was determined by adverse rainfall conditions......At the household level, nonfarm activities are thought to help rural poor households buffer against agricultural risks related to local climate variability by providing them with cash to buy food in the case of harvest shortfalls. Over the recent decades, households in rural Sub-Sahara have been...... found less dependent on land and subsistence agriculture and an increasing number of households here derive their income from nonfarm activities. This study tests the hypothesis that rural households in Burkina Faso have diversified to the extent that they no longer rely on nonfarm activities...

  18. Tackling Health Inequalities Locally

    DEFF Research Database (Denmark)

    Diderichsen, Finn; Scheele, Christian Elling; Little, Ingvild Gundersen

    equality and growth (64). Health equity has been anexplicit political goal in Scandinavia for decades. Nevertheless, in the health domain, average improvement has not been followed by reduced inequality – at least not between socioeconomic groups. It has in other words turned out to be a challenge...... of translating small inequalities in wealth into small inequalities in health. Denmark, Norway and Sweden all have legislation that indifferent ways offers local governments key roles in public health. This is partly due to local governments’ responsibility for many policy areas of great relevance to health...... and health equity. National governments have thus largely made the WHO and EU recommendation of ‘Health in All Policies’a local responsibility. In his analysis for the Nordic Council of Ministers, former Swedish Minister of Health Bo Könberg identifies tackling health inequalities as one of 14 prioritised...

  19. Development of Local Chicken Production Based on Local Feed Ingredients

    Directory of Open Access Journals (Sweden)

    Cecep Hidayat

    2012-06-01

    Full Text Available Development of local chicken production based on local feed ingredient is in line with the vision of Indonesian goverment to fulfill meat and egg national requirement based on local resources. There are two big problem which become stumblingblock in developing local chicken production. The first problem is the difficulty to get day old chick of local chicken. This problem can be solved by integrating breeder institutions belong to goverment with research institution and with local chicken producer association. The second problem is the low performance of local chicken. To improve local chicken performance, it can be done by improving the breed, feed and management. Several research results show that good performance of local chicken were obtained by inclusion of local feed ingredients in the ration. Therefore, development of local chicken production based an local feed resources can be applied.

  20. Frequently Asked Questions (FAQs) About Local Foods, Local Places

    Science.gov (United States)

    Answers to frequently asked questions about EPA's Local Foods, Local Places planning assistance program to help communities revitalize downtowns, create economic opportunities, and improve access to healthy food by promoting local foods.

  1. Photon Localization Revisited

    Directory of Open Access Journals (Sweden)

    Izumi Ojima

    2015-09-01

    Full Text Available In the light of the Newton–Wigner–Wightman theorem of localizability question, we have proposed before a typical generation mechanism of effective mass for photons to be localized in the form of polaritons owing to photon-media interactions. In this paper, the general essence of this example model is extracted in such a form as quantum field ontology associated with the eventualization principle, which enables us to explain the mutual relations, back and forth, between quantum fields and various forms of particles in the localized form of the former.

  2. Local versus national

    DEFF Research Database (Denmark)

    Milan, Christian; Nielsen, Mads Pagh; Bojesen, Carsten

    2014-01-01

    of individual energy supply systems based on on-site weather and building conditions, as well as considering the expected energy consumption profile. However, local planning processes are problematic if they do not take regional or national impacts into account. Given the grid connection, the local building...... is to adapt the earlier proposed methodology by integrating flexible national electricity prices and thus taking account for the aforementioned effects. The methodology is applied in a case study for a single family house under Danish conditions. The results show that the system configuration might...

  3. Health monitoring of unmanned aerial vehicle based on optical fiber sensor array

    Science.gov (United States)

    Luo, Yuxiang; Shen, Jingshi; Shao, Fei; Guo, Chunhui; Yang, Ning; Zhang, Jiande

    2017-10-01

    The unmanned aerial vehicle (UAV) in flight needs to face the complicated environment, especially to withstand harsh weather conditions, such as the temperature and pressure. Compared with conventional sensors, fiber Bragg grating (FBG) sensor has the advantages of small size, light weight, high reliability, high precision, anti-electromagnetic interference, long lift-span, moistureproof and good resistance to causticity. It's easy to be embedded in composite structural components of UAVs. In the paper, over 1000 FBG sensors distribute regularly on a wide range of UAVs body, combining wavelength division multiplexing (WDM), time division multiplexing (TDM) and multichannel parallel architecture. WDM has the advantage of high spatial resolution. TDM has the advantage of large capacity and wide range. It is worthful to constitute a sensor network by different technologies. For the signal demodulation of FBG sensor array, WDM works by means of wavelength scanning light sources and F-P etalon. TDM adopts the technology of optical time-domain reflectometry. In order to demodulate efficiently, the most proper sensor multiplex number with some reflectivity is given by the curves fitting. Due to the regular array arrangement of FBG sensors on the UAVs, we can acquire the health state of UAVs in the form of 3D visualization. It is helpful to master the information of health status rapidly and give a real-time health evaluation.

  4. Global and Local Textuality.

    Science.gov (United States)

    Campbell, B. G.

    Coherence and cohesion are fundamental considerations of the composing process that help to define the global and local components of texuality. Global text coherence centers on those aspects of the familiar rhetorical situation. Coherence operates at the paragraph and essay levels, answering questions about focus, tone, mode, topic, and thesis.…

  5. Local Color Correction

    Directory of Open Access Journals (Sweden)

    Juan Gabriel Gomila Salas

    2011-09-01

    Full Text Available In this paper we present a local algorithm for contrast enhancement developed by N. Moroney at Hewlett-Packard Laboratories and presented at the IS&T/SID Eight Color Imaging Conference, in 2000. The algorithm uses a non-linear masking, is fast and does not require any manual parameter adjustments.

  6. Local anaesthetic toxicity

    African Journals Online (AJOL)

    The Austrian pharmacologist Karl Damian Ritter von Schorff was the first to think of cocaine as a narcotic. He noticed skin insensibility after the application of cocaine and postulated a central nervous system effect as mechanism of action. In 1884,. Sigmund Freud proposed the use of cocaine as local anaesthetic to his friend ...

  7. Robust and Secure Localization

    Science.gov (United States)

    2009-06-03

    attacker-chosen location to the nodes as they are deployed.  establish wormhole links and tunnel legitimate messages to distant locations in the...network which are beyond the radio range of the source nodes. The wormhole attack can potentially introduce significant localization error of any node

  8. Local government in Ethiopia

    African Journals Online (AJOL)

    LAW

    farmers would find themselves being rounded up at gun point by the local defence squad, and forcibly dispatched...”69. The involvement of UDAs and PAs in the forceful conscription of young people into the government's army was another control oriented action. Derg was forcefully conscripting young Ethiopians for the ...

  9. Stroke? Localized, otogenic meningitis!

    DEFF Research Database (Denmark)

    Ingolfsdottir, Harpa Maria; Thomasen, Per Caye

    2011-01-01

    We report the case of a patient admitted with aphasia, treated for a stroke. Subsequently, it was revealed that the symptoms were caused by complicated otitis media with localized meningitis. This case draws attention to the possible intracranial spread of infection when neurological symptoms occur...

  10. HOW PARTICIPATION SHAPES LOCAL DEVELOPMENT

    Directory of Open Access Journals (Sweden)

    Muhadjir Darwin

    2016-12-01

    Full Text Available This article elaborates citizens’ participation in shaping local development in the Indonesian context. The main question is how to make local development more participatory as a guarantee that citizens’ rights are fully realized. In that respects, social accountability is a key that should be improved from supply and demand sides simultaneously. From the supply side, there is a need to reform local governance, in order to improve the quality of local regulations, local planning, local budgeting, and local public service provision. While from the demand side, there is a need to empower local citizens so that they are engaged in five forms or local development efforts: local regulation formulation, local development planning, local budgeting, community driven development, and public service provision.

  11. Double localization of neuro lymphomatosis in an early relapse of non-Hodgkin lymphoma and ({sup 18}F)-F.D.G. PET-CT: Case report;Double localisation de neurolymphomatose d'une rechute prcoce d'un lymphome non hodgkinien en TEP-TDM au ({sup 18}F)-FDG: a propos d'un cas

    Energy Technology Data Exchange (ETDEWEB)

    Cazaentre, T.; Pascal-ortiz, D. [Hopital Saint-Jean, Service de medecine nucleaire, 66 - Perpignan (France); Sanhes, L.; Vallantin, X. [Hopital Saint-Jean, Service d' hematologie, 66 - Perpignan (France); Cassarini, J.F. [Hopital Saint-Jean, Service de neurologie, 66 - Perpignan (France)

    2010-06-15

    In a patient suffering from left lower limb pain and chin anesthesia, fused PET-CT imaging showed an ({sup 18}F)-F.D.G. uptake along the left sciatic nerve and the mandibular branch of the left trigeminal nerve corresponding to neuro lymphomatosis due to an early relapse of a B-cell non-Hodgkin's lymphoma. (authors)

  12. Electron localization functions and local measures of the covariance

    Indian Academy of Sciences (India)

    The electron localization measure proposed by Becke and Edgecombe is shown to be related to the covariance of the electron pair distribution. Just as with the electron localization function, the local covariance does not seem to be, in and of itself, a useful quantity for elucidating shell structure. A function of the local ...

  13. Brane-Localized Gravity

    CERN Document Server

    Mannheim, Philip D

    2005-01-01

    This timely and valuable book provides a detailed pedagogical introduction and treatment of the brane-localized gravity program of Randall and Sundrum, in which gravitational signals are able to localize around our four-dimensional world in the event that it is a brane embedded in an infinitely-sized, higher dimensional anti-de Sitter bulk space. A completely self-contained development of the material needed for brane-world studies is provided for both students and workers in the field, with a significant amount of the material being previously unpublished. Particular attention is given to issues not ordinarily treated in the brane-world literature, such as the completeness of tensor gravitational fluctuation modes, the causality of brane-world propagators, and the status of the massless graviton fluctuation mode in brane worlds in which it is not normalizable.

  14. Photonic local oscillator development

    Science.gov (United States)

    Kimberk, Robert; Tong, Edward; Hunter, Todd R.; Christensen, Robert; Blundell, Ray

    2006-12-01

    In the receiver lab, we have developed a 200 GHz to 230 GHz local oscillator constructed from mostly commercially available 1550 nm laser communication components. Theoretical and experimental work show that the laser adds negligible phase noise to this photonic local oscillator system and that spectral purity and phase stability are similar to Gunn oscillator based local oscillator output. The optical path consists of a single 1550 nm diode laser, a lithium niobate optical phase modulator, a Mach Zehnder interferometer (MZI) with a free spectral range of 75 GHz, and a 160 GHz to 260 GHz photomixer whose output is connected to a horn antenna. All of the optical devices and connections are polarization maintaining, and the photomixer was designed and fabricated at the CCLRC Rutherford Appleton Laboratory. The electrical path consists of a YIG synthesizer, operating in the frequency range 14-20 GHz, a frequency doubler, and a power amplifier connected to the RF port of the phase modulator. At the SMA on Mauna Kea, we incorporated the photonic LO into one element (Antenna 6) of a five antenna array for test observations of CO J=2-1 made towards the ultracompact HII region G138.295+1.555. Spectral features of comparable width occur on baselines with and without antenna 6, and noise increases with baseline length independent of antenna number. Continuum observations were also made toward the quasar 3c454.3 for a period of about one hour. In summary, the SMA has proven that the photonic local oscillator operates with adequate phase and frequency stability for radio-interferometry.

  15. Rationalising localism and brokerage

    DEFF Research Database (Denmark)

    Kusche, Isabel

    2017-01-01

    . The article employs the notion of global scripts and the concept of domestication of global trends in order to analyse how the question of the appropriate relationship between deputies and voters is informed both by a general trend towards the professionalisation of politicians and a domestic tradition...... of the domestic setting on the other. In this way the article contributes to a better understanding of the entanglement of the global and the local....

  16. Local Rotational Symmetries.

    Science.gov (United States)

    1985-08-01

    way to choose among them. Spirals can occur in natural figures, e.g. a spiralled tail or a coil of rope or vine tendril, and in line drawings. Since...generated and removes it and all regions similar to it from the list of regions. The end result is a pruned list of distinct optimal regions. 4.7...that, at least to a first approximation, the potential symmetry regions pruned by the locality restriction are not perceptually salient. For example

  17. Local Noncollinear Spin Analysis.

    Science.gov (United States)

    Abate, Bayileyegn A; Joshi, Rajendra P; Peralta, Juan E

    2017-12-12

    In this work, we generalize the local spin analysis of Clark and Davidson [J. Chem. Phys. 2001 115 (16), 7382] for the partitioning of the expectation value of the molecular spin square operator, ⟨Ŝ 2 ⟩, into atomic contributions, ⟨Ŝ A ·Ŝ B ⟩, to the noncollinear spin case in the framework of density functional theory (DFT). We derive the working equations, and we show applications to the analysis of the noncollinear spin solutions of typical spin-frustrated systems and to the calculation of magnetic exchange couplings. In the former case, we employ the triangular H 3 He 3 test molecule and a Mn 3 complex to show that the local spin analysis provides additional information that complements the standard one-particle spin population analysis. For the calculation of magnetic exchange couplings, J AB , we employ the local spin partitioning to extract ⟨Ŝ A ·Ŝ B ⟩ as a function of the interatomic spin orientation given by the angle θ. This, combined with the dependence of the electronic energy with θ, provides a methodology to extract J AB from DFT calculations that, in contrast to conventional energy differences based methods, does not require the use of ad hoc S A and S B values.

  18. Many-box locality

    Science.gov (United States)

    Zhou, Yuqian; Cai, Yu; Bancal, Jean-Daniel; Gao, Fei; Scarani, Valerio

    2017-11-01

    There is an ongoing search for a physical or operational definition for quantum mechanics. Several informational principles have been proposed which are satisfied by a theory less restrictive than quantum mechanics. Here, we introduce the principle of "many-box locality," which is a refined version of the previously proposed "macroscopic locality." These principles are based on coarse graining the statistics of several copies of a given box. The set of behaviors satisfying many-box locality for N boxes is denoted LNM B. We study these sets in the bipartite scenario with two binary measurements, in relation with the sets Q and Q1 +A B of quantum and "almost quantum" correlations, respectively. We find that the LNM B sets are, in general, not convex. For unbiased marginals, by working in the Fourier space we can prove analytically that LNM B⊈Q for any finite N , while L∞M B=Q . Then, with suitably developed numerical tools, we find an example of a point that belongs to L16M B but not to Q1 +A B. Among the problems that remain open is whether Q ⊂L∞M B .

  19. Local dependency in networks

    Directory of Open Access Journals (Sweden)

    Kudĕlka Miloš

    2015-06-01

    Full Text Available Many real world data and processes have a network structure and can usefully be represented as graphs. Network analysis focuses on the relations among the nodes exploring the properties of each network. We introduce a method for measuring the strength of the relationship between two nodes of a network and for their ranking. This method is applicable to all kinds of networks, including directed and weighted networks. The approach extracts dependency relations among the network’s nodes from the structure in local surroundings of individual nodes. For the tasks we deal with in this article, the key technical parameter is locality. Since only the surroundings of the examined nodes are used in computations, there is no need to analyze the entire network. This allows the application of our approach in the area of large-scale networks. We present several experiments using small networks as well as large-scale artificial and real world networks. The results of the experiments show high effectiveness due to the locality of our approach and also high quality node ranking comparable to PageRank.

  20. Factors Affecting Quality of Life at Different Intervals After Treatment of Localized Prostate Cancer: Unique Influence of Treatment Decision Making Satisfaction, Personality and Sexual Functioning.

    Science.gov (United States)

    Victorson, David E; Schuette, Stephanie; Schalet, Benjamin D; Kundu, Shilajit D; Helfand, Brian T; Novakovic, Kristian; Sufrin, Nathaniel; McGuire, Michael; Brendler, Charles

    2016-11-01

    Using patient reported outcomes measures we identified the most informative set of factors associated with quality of life in a large sample of men treated for localized prostate cancer. We examined relationships with quality of life using FACIT (Functional Assessment of Chronic Illness Therapy). We also hypothesized variables in a sample of men diagnosed with localized prostate cancer who represented different time points since treatment, including less than 12 months in 70, 1 to 3 years in 344, greater than 3 to 5 years in 291 and greater than 5 years in 97. Correlative measures included subscales of MAX-PC (Memorial Anxiety Scale for Prostate Cancer), short forms of PROMIS® and SOMS (Surgical Outcomes Measurement System), TDM-SATS (Treatment Decision-Making Satisfaction Scale) and subscales of the BFI (Big Five Inventory) of personality. Quality of life was significantly associated with hypothesized variables across different time cohorts. In regression models several factors accounted for most of the variability in quality of life scores depending on time since treatment, including 47%, 22%, 29% and 27% at less than 12 months, 1 to 3 years, greater than 3 to 5 years and greater than 5 years, respectively. Upon examining the unique contribution of these variables, treatment decision making satisfaction was the only variable to have a significant and unique contribution to quality of life across all 4 time cohorts (standardized coefficients 0.33, 0.27, 0.31 and 0.49, respectively, p style also had unique associations with quality of life (standardized coefficients 0.25 and -0.20, respectively). When considering the short-term and the longer term quality of life of a man after treatment for localized prostate cancer, our findings highlight the importance of treatment decision making satisfaction, erectile function and personality. Copyright © 2016 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.

  1. New Communication Technologies, Local Journalism and the Perception of Locality

    Directory of Open Access Journals (Sweden)

    Ali ÖZCAN

    2016-12-01

    Full Text Available Studies on local journalism as an important element of participatory democracy generally focus on the history of the local press, the financial insufficiencies of local newspapers as well as technical/ technological incompetency that occurs as a result of these factors. This research analyzes local newspapers with a new scientific point of view by focusing on the perception of locality as a mental projection of geographical constraint. Perspectives regarding the transformations on perceptions of locality as a result of the disappearance of time and space constraints due to new communication technologies, and the opportunities that new communication environments offer to local newspapers will be provided. Moreover, the ways in which local newspapers reflect on locality with their printed versions under time and space constraints will be analyzed. The research scope of the study has been limited to 15 newspapers in Konya. Structured interviews and content analysis methods were used for data collection and analysis.

  2. Localized defects in ophthalmic lenses.

    Science.gov (United States)

    Stroud, J S

    1989-03-01

    Ophthalmic lenses made from glass, hard resin, and polycarbonate are inspected with a shadowgraph to determine the nature, frequency, and severity of localized defects, including power aberrations. The most common localized defects are scratches and pits left by incomplete polishing and localized power aberrations caused by variations in the thickness of scratch-resistant coatings. Localized defects are more likely in polycarbonate lenses than in glass or hard resin lenses. The compliance of lenses with standards that limit localized defects is discussed.

  3. Localization of CANDU technology

    Energy Technology Data Exchange (ETDEWEB)

    Alizadeh, Ala

    2010-09-15

    The CANDU pressurized heavy water reactor's principal design features suit it particularly well for technology transfer and localization. When the first commercial CANDU reactors of 540 MWe entered service in 1971, Canada's population of less than 24 million supported a 'medium' level of industrial development, lacking the heavy industrial capabilities of larger countries like the USA, Japan and Europe. A key motivation for Canada in developing the CANDU design was to ensure that Canada would have the autonomous capacity to build and operate nuclear power reactors without depending on foreign sources for key components or enriched fuel.

  4. Local analytic geometry

    CERN Document Server

    Abhyankar, Shreeram Shankar

    1964-01-01

    This book provides, for use in a graduate course or for self-study by graduate students, a well-motivated treatment of several topics, especially the following: (1) algebraic treatment of several complex variables; (2) geometric approach to algebraic geometry via analytic sets; (3) survey of local algebra; (4) survey of sheaf theory. The book has been written in the spirit of Weierstrass. Power series play the dominant role. The treatment, being algebraic, is not restricted to complex numbers, but remains valid over any complete-valued field. This makes it applicable to situations arising from

  5. Localized Acoustic Surface Modes

    KAUST Repository

    Farhat, Mohamed

    2015-08-04

    We introduce the concept of localized acoustic surface modes (ASMs). We demonstrate that they are induced on a two-dimensional cylindrical rigid surface with subwavelength corrugations under excitation by an incident acoustic plane wave. Our results show that the corrugated rigid surface is acoustically equivalent to a cylindrical scatterer with uniform mass density that can be represented using a Drude-like model. This, indeed, suggests that plasmonic-like acoustic materials can be engineered with potential applications in various areas including sensing, imaging, and cloaking.

  6. Spatially localized magnetoconvection

    Energy Technology Data Exchange (ETDEWEB)

    Lo Jacono, D; Bergeon, A [Universite de Toulouse (France); INPT, UPS, Institut de Mecanique des Fluides de Toulouse (IMFT), Allee Camille Soula, F-31400 Toulouse (France); Knobloch, E, E-mail: lojacono@imft.fr, E-mail: bergeon@imft.fr, E-mail: knobloch@berkeley.edu [Department of Physics, University of California, Berkeley, CA 94720 (United States)

    2012-06-01

    Numerical continuation is used to compute branches of time-independent, spatially localized convectons in an imposed vertical magnetic field focusing on values of the Chandrasekhar number Q in the range 10 < Q < 10{sup 3}. The calculations reveal that convectons initially grow by nucleating additional cells on either side, but with the build-up of field outside owing to flux expulsion, the convectons are able to transport more heat only by expanding the constituent cells. Thus, at large Q and large Rayleigh numbers, convectons consist of a small number of broad cells. (paper)

  7. 'Joined Up' Local Governments?

    DEFF Research Database (Denmark)

    Bjørnå, Hilde; Casale, Donatella; Hajnal, Gyorgy

    of such studies and comparative studies are lacking. With this, we ask how can local JUG initiatives be explained and what lessons can be drawn from a comparative perspective? Drawing on some components from the framework by Pollitt and Bouckaert (2011) for public management reforms, we analyse JUG reforms in six....... forthc. 2015, Lægreid et al. 2014, Pollitt 2003). A growing body of research analyses JUG initiatives in several countries, but often in the form of single-case studies with central government focus (see e.g. Talbot 2011 or Lægreid et al. 2014). On municipal level, however, there is only a scarce number...

  8. The Local Fractional Bootstrap

    DEFF Research Database (Denmark)

    Bennedsen, Mikkel; Hounyo, Ulrich; Lunde, Asger

    new resampling method, the local fractional bootstrap, relies on simulating an auxiliary fractional Brownian motion that mimics the fine properties of high frequency differences of the Brownian semistationary process under the null hypothesis. We prove the first order validity of the bootstrap method...... and in simulations we observe that the bootstrap-based hypothesis test provides considerable finite-sample improvements over an existing test that is based on a central limit theorem. This is important when studying the roughness properties of time series data; we illustrate this by applying the bootstrap method...

  9. Changing local land systems

    DEFF Research Database (Denmark)

    Friis, Cecilie; Reenberg, Anette; Heinimann, Andreas

    2016-01-01

    This paper investigates the direct and cascading land system consequences of a Chinese company's land acquisition for rubber cultivation in northern Laos. Transnational land acquisitions are increasingly acknowledged as an important driver of direct land use conversion with implications for local...... land-based livelihoods. The paper presents an empirical case study of the village of Na Nhang Neua in Nambak District, Luang Prabang Province, using a mixed methods approach to investigate the positive and negative implications for household agricultural strategies, income generation and food security...

  10. Local Laplacian Coding From Theoretical Analysis of Local Coding Schemes for Locally Linear Classification.

    Science.gov (United States)

    Pang, Junbiao; Qin, Lei; Zhang, Chunjie; Zhang, Weigang; Huang, Qingming; Yin, Baocai

    2015-12-01

    Local coordinate coding (LCC) is a framework to approximate a Lipschitz smooth function by combining linear functions into a nonlinear one. For locally linear classification, LCC requires a coding scheme that heavily determines the nonlinear approximation ability, posing two main challenges: 1) the locality making faraway anchors have smaller influences on current data and 2) the flexibility balancing well between the reconstruction of current data and the locality. In this paper, we address the problem from the theoretical analysis of the simplest local coding schemes, i.e., local Gaussian coding and local student coding, and propose local Laplacian coding (LPC) to achieve the locality and the flexibility. We apply LPC into locally linear classifiers to solve diverse classification tasks. The comparable or exceeded performances of state-of-the-art methods demonstrate the effectiveness of the proposed method.

  11. Locality and reality

    Energy Technology Data Exchange (ETDEWEB)

    Stapp, Henry P.

    1980-10-01

    Einstein's principle that no signal travels faster than suggests that observations in one spacetime region should not depend on whether or not a radioactive decay is detected in a spacelike separated region. This locality property is incompatible with the predictions of quantum theory, and this incompatibility holds independently of the questions of realism, objective reality, and hidden variables. It holds both in the pragmatic quantum theory of Bohr and in realistic frameworks. It is shown here to hold in a completed realistic quantum theory that reconciles Einstein's demand for a description of reality itself with Bohr's contention that quantum theory is complete. This completed realistic quantum theory has no hidden variables, and no objective reality in which observable attributes can become definite independently of observers. The, theory is described in some detail, with particular attention to those aspects related to the question of locality. This completed realistic quantum theory is in principle more comprehensive than Bohr.' s pragmatic quantum theory because it is not limited in principle by the requirement that the observed system be physically separated from the observing one. Applications are discussed.

  12. Pattern Driven Stress Localization

    Science.gov (United States)

    Croll, Andrew; Crosby, Alfred

    2010-03-01

    The self-assembly of patterns from isotropic initial states is a major driver of modern soft-matter research. This avenue of study is directed by the desire to understand the complex physics of the varied structures found in Nature, and by technological interest in functional materials that may be derived through biomimicry. In this work we show how a simple striped phase can respond with significant complexity to an appropriately chosen perturbation. In particular, we show how a buckled elastic plate transitions into a state of stress localization using a simple, self-assembled variation in surface topography. The collection of topographic boundaries act in concert to change the state from isotropic sinusoidal wrinkles, to sharp folds or creases separated by relatively flat regions. By varying the size of the imposed topographic pattern or the wavelength of the wrinkles, we construct a state diagram of the system. The localized state has implications for both biological systems, and for the control of non-linear pattern formation.

  13. Local moduli and singularities

    CERN Document Server

    Laudal, Olav Arnfinn

    1988-01-01

    This research monograph sets out to study the notion of a local moduli suite of algebraic objects like e.g. schemes, singularities or Lie algebras and provides a framework for this. The basic idea is to work with the action of the kernel of the Kodaira-Spencer map, on the base space of a versal family. The main results are the existence, in a general context, of a local moduli suite in the category of algebraic spaces, and the proof that, generically, this moduli suite is the quotient of a canonical filtration of the base space of the versal family by the action of the Kodaira-Spencer kernel. Applied to the special case of quasihomogenous hypersurfaces, these ideas provide the framework for the proof of the existence of a coarse moduli scheme for plane curve singularities with fixed semigroup and minimal Tjurina number . An example shows that for arbitrary the corresponding moduli space is not, in general, a scheme. The book addresses mathematicians working on problems of moduli, in algebraic or in complex an...

  14. A digital local studies collection

    Directory of Open Access Journals (Sweden)

    Simona Resman

    2005-01-01

    Full Text Available Local studies and local studies departments reflect the entire spectrum of knowledge within the local community. Transition to the new digital environment means just continuing the basic functions of local studies collections: acquisition, cataloguing and preservation of materials in different formats on different media. The background of each digital library is the technical architecture of system that enables interaction between the user and the library, saving digital material and building a platform for searching and indexing digital objects. Using advanced ICT requests from librarians, designers of digital local studies collections a reflection about traditional roles. A digital local studies collection with new technology enlarges local boarders, local contents become more and more interesting for a wider sphere of people. In collecting of local materials a collaboration with archives and museums, with academic community, with community groups and with individuals comes in forefront. Digital local studies collections with their contents support local diversity, lifelong learning and social inclusion. The crucial elements of a digital local studies collection are attractive local contents with fast and simple access from one place – a portal. In the digital age public libraries become managers of knowledge also by establishing digital local studies collections.

  15. Local government reform: problematic aspects

    Directory of Open Access Journals (Sweden)

    Y. P. Sharov

    2014-06-01

    Full Text Available In the article the actual problems aspects of realization of reform of local self-government are worked up, namely: reformation of institute of local state administrations, creation of executive branches of local Rada, «technology» of realization of administrative-territorial device, place and role of strategic and project approaches, statutory and regulatory support of integrative forms of territorial communities activity, modern forms of professional communication of local government’s personal, using the potential of associations of local government’s practitioners; directions of development of human factor of reform and administrative system are analyzed in local self-government on principles of management achievements.

  16. Natural resources management by local associations in Ifedore local ...

    African Journals Online (AJOL)

    Management of natural resource by local associations not only in its socio ecological but also in its socio economic context will go a long way in reducing environmental degradation in some local communities. This study examined the operational capacity for natural resource management by local associations in Ifedore ...

  17. Local Agenda 21 - from global idea to local action

    DEFF Research Database (Denmark)

    Hoffmann, Birgitte

    1999-01-01

    The article give a status of the Danish works with Local Agenda 21 and discusses Local Agenda 21 as a planning tool. It describes the idea of Local Agenda 21 as a large meeting, which everybody attends. This picture is elaborated and discussed form different angles: the items on the agenda...

  18. Finance reform under local integration

    Directory of Open Access Journals (Sweden)

    S. S. Seryohin

    2016-06-01

    Full Text Available Abstract Revealed the essence of local finance manifested in economic relations, and their structure is a combination of local budgets, special purpose budget funds; budget funds of local governments; public funds of funds banks if their share capital formed at the expense of local governments; fund municipal enterprises, institutions and organizations. The analysis on fundamental scientific research on local budgets.Defined-purpose local governments.Systematized theoretical definition of municipal finances. Formed impact of reform of local finance to ensure the improvement of socio-economic status of the region to the European Union for more confident of Ukraine’s integration into Europe. Found that implementing fiscal policy in terms of spending, local authorities are guided by the priorities of socio-economic development of the region or administrative unit in line with national principles defined government policy document. Discovered topical issues of local budgets as the existence of significant differences in the regulatory and legislative framework - the excessive centralization of local budgets unstable sources of local revenues inadequacy of intergovernmental relations. It was found that to radically change the existing system of functioning of local budgets, as required considerable time gap and improving the theoretical and methodological and regulatory framework of the local budgets.

  19. Apport de la tomodensitometrie (TDM) cerebrale chez le sujet adulte ...

    African Journals Online (AJOL)

    Methodology : It is about a descriptive and analytical retrospective study over one 36 months period (Mars 1998 at Mars 2001) relating to 68 files of adult patients HIV positive, having made the cerebral. CT with the CHU-Campus or the International Polyclinic Joseph Saint. Result: The contribution or cerebral examination CT ...

  20. Optical Systems for Ultra-High-Speed TDM Networking

    DEFF Research Database (Denmark)

    Galili, Michael; Hu, Hao; Mulvad, Hans Christian Hansen

    2014-01-01

    This paper discusses key results in the field of high speed optical networking with particular focus on packet-based systems. Schemes for optical packet labeling, packet switching and packet synchronization will be discussed, along with schemes for optical clock recovery, channel identification...... and detection of ultra-high-speed optical signals....

  1. Optical Systems for Ultra-High-Speed TDM Networking

    Directory of Open Access Journals (Sweden)

    Michael Galili

    2014-04-01

    Full Text Available This paper discusses key results in the field of high speed optical networking with particular focus on packet-based systems. Schemes for optical packet labeling, packet switching and packet synchronization will be discussed, along with schemes for optical clock recovery, channel identification and detection of ultra-high-speed optical signals.

  2. Headphone localization of speech

    Science.gov (United States)

    Begault, Durand R.; Wenzel, Elizabeth M.

    1993-01-01

    Three-dimensional acoustic display systems have recently been developed that synthesize virtual sound sources over headphones based on filtering by head-related transfer functions (HRTFs), the direction-dependent spectral changes caused primarily by the pinnae. In this study, 11 inexperienced subjects judged the apparent spatial location of headphone-presented speech stimuli filtered with nonindividualized HRTFs. About half of the subjects 'pulled' their judgments toward either the median or the lateral-vertical planes, and estimates were almost always elevated. Individual differences were pronounced for the distance judgments; 15 to 46 percent of stimuli were heard inside the head, with the shortest estimates near the median plane. The results suggest that most listeners can obtain useful azimuth information from speech stimuli filtered by nonindividualized HRTFs. Measurements of localization error and reversal rates are comparable with a previous study that used broadband noise stimuli.

  3. Local Stellarator Equilibrium Model

    Science.gov (United States)

    Hudson, Stuart R.; Hegna, Chris C.; Lewandowski, Jerome W.

    2000-10-01

    Extensive calculations of ballooning and drift waves spectrums in asymmetric toroidal configurations (e.g. stellarators) to appreciate the role of magnetic geometry and profile variations are usually are usually prohibitive as the evaluation of the magneto-hydrodynamic (MHD) equilibrium is in itself a non-trivial problem. Although simple analytical MHD model equilibria do exist for tokamak configurations, their stellarator counterparts are usually crude or very approximate. In order to make more extensive stability calculations (of both ideal ballooning and drift-type modes), a technique for generating three-dimensional magneto-static equilibria, localized to a magnetic surface, has been developed. The technique allows one to easily manipulate various 3-D shaping and profile effects on a magnetic surface avoiding the need to recompute an entire three dimensional solution of the equilibrium. The model equilibrium has been implemented into existing ideal MHD ballooning and drift wave numerical codes. Marginal ballooning stability diagrams and drift wave calculations will be reported.

  4. Support your local species

    DEFF Research Database (Denmark)

    Stärk, Johanna

    Nearly a quarter of all animal species within the European Union are threatened with extinction. Protecting many of these species will require the full spectrum of conservation actions from in-situ to ex-situ management. Holding an estimated 44% of EU Red Listed terrestrial vertebrates, zoos hereby...... play an important role in protecting local species. However, outcomes of conservation actions are often highly uncertain and if European zoos want to support the conservation of threatened species, they are faced with the question of which species to target first and which conservation strategy...... to choose. Current decision-making in resource allocation and conservation planning is often, as in many other disciplines, based on little scientific ground. Here, we propose a Decision Analysis framework to support the Ex-situ guidelines of the Species Survival Commission of the IUCN. In which we assessed...

  5. Narcotics and local anesthetics.

    Science.gov (United States)

    Kamerling, S G

    1993-12-01

    The recognition and alleviation of animal pain is a growing veterinary and public concern. Pain can be of an acute or chronic nature with different behavioral manifestations. Physiologically, pain is a dynamic and complex phenomenon that produces changes in the central and autonomic nervous systems as well as in the endocrine system. Horses and other animals appear to possess an endogenous pain-suppressing system involving the brainstem and spinal cord. This system can modulate pain perception and the responses to it. The recently discovered endogenous opioid peptides (endorphins and enkephalins) appear to play a role in this system, which is activated by stress. Opioids (narcotic analgesics) act to selectively depress pain-sensitive cells. Opioid analgesics may act via multiple opioid receptors. Each subclass of opioid receptor has a different pharmacologic profile. Classical opioids that act at mu (morphine) receptors typically produce analgesia, increased locomotor activity, cardiorespiratory stimulation, and a decrease in intestinal peristalsis in the horse. Opioids that act at kappa receptors produce analgesia, sedation, ataxia, and minimal autonomic effects in the horse. Owing to their lack of excitatory actions, the kappa opioids represent a potentially useful class of analgesics for use in equine species. Local anesthetics depress all excitable cells and can diminish sensory, motor, and muscular function. They do not act selectively on pain fibers, although pain is among the first sensations lost following a nerve block. Local anesthetic activity is enhanced by increased extraneuronal pH, nerve cooling, increased nervous activity, coadministration of a vasoconstrictor or hyaluronidase, delayed systemic absorption, prolonged drug metabolism, and by using agents with high lipid solubility. Procaine, lidocaine, and mepivacaine are among the most widely used and studied agents in horses. These agents and/or their metabolites can be readily detected in urine; in

  6. Local communities as meso structures.

    Directory of Open Access Journals (Sweden)

    Ferrand, Alexis

    2002-09-01

    Full Text Available In between micro and macro levels: meso. If macro is defined by national, state or market regulation, and micro by relational interpersonnal regulation, a major agency of intermediate regulation has been defined as "local communities" (Wellmann, Fischer. Apart the organizational (local organizations, clubs, shops... and institutional (local power, parties,... dimensions of localities, it is possible to define some pertinent structural properties of systems of private interpersonal relations : one is the degree of local closure (Barnes : local vs transversal networks, or the "duality" of these systems. Grounded on the idea that the efficiency of "bridges" rest upon the kind of cliques they connect (Lin, it is possible to define various types of micro-structures, the distributions of which in different localities are proxy indicators of the different meso structures of relational systems as combinations of "local" and "unlocal" networks.

  7. Local Climatological Data ACSII Format

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Comma-delimited text files used to create the Local Climatological Data PDF files found in the Local Climatological Data library. Period of record begins in 1998,...

  8. Inference for local autocorrelations in locally stationary models.

    Science.gov (United States)

    Zhao, Zhibiao

    2015-04-01

    For non-stationary processes, the time-varying correlation structure provides useful insights into the underlying model dynamics. We study estimation and inferences for local autocorrelation process in locally stationary time series. Our constructed simultaneous confidence band can be used to address important hypothesis testing problems, such as whether the local autocorrelation process is indeed time-varying and whether the local autocorrelation is zero. In particular, our result provides an important generalization of the R function acf() to locally stationary Gaussian processes. Simulation studies and two empirical applications are developed. For the global temperature series, we find that the local autocorrelations are time-varying and have a "V" shape during 1910-1960. For the S&P 500 index, we conclude that the returns satisfy the efficient-market hypothesis whereas the magnitudes of returns show significant local autocorrelations.

  9. [Local treatment of liver tumors

    DEFF Research Database (Denmark)

    Pless, T.K.; Skjoldbye, Bjørn Ole

    2008-01-01

    Local treatment of non-resectable liver tumors is common. This brief review describes the local treatment techniques used in Denmark. The techniques are evaluated according to the evidence in literature. The primary local treatment is Radiofrequency Ablation of both primary liver tumors and liver...

  10. Business Models for Local Foods

    DEFF Research Database (Denmark)

    Esbjerg, Lars; Pedersen, Maja; Pederson, Robert

    2014-01-01

    Interest in local foods is growing, but there has been limited research on who and why producers of local foods thrive or struggle. A particularly important problem for local food producers is how to reach end consumers, as they often find it difficult to work with the retail chains that dominate...

  11. Local community, mobility and belonging

    DEFF Research Database (Denmark)

    Jørgensen, Anja; Arp Fallov, Mia; Knudsen, Lisbeth B.

    2011-01-01

    the marginalised groups as contained in local neighbourhoods,while ascribing freedom and reflexivity exclusively to the middle and upper classes.The study of local communities in urban environments has a long tradition in the science of sociology and it is concluded that revitalizing and methodologically updating...... the classic Chicago school of sociology can create a productive approach to the study of local community, mobility and belonging.......The purpose of this article is to pose some theoretical questions to the relations between local community, mobility and belonging.In continuation the methodological implications of the theoretical debate are discussed.The article also outlines different perspectives on local neighbourhoods...

  12. Turismo y desarrollo local

    Directory of Open Access Journals (Sweden)

    Guillermo Díaz

    2017-01-01

    Full Text Available El turismo constituye motor de desarrollo local en áreas rurales, según se desprende de la experiencia del municipio de San Francisco Zapotitlán, en el departamento de Retalhuleu, en Guatemala, donde se ubica el centro recreativo IRTRA, que recibe tantos visitantes como turistas extranjeros el país. Dicho municipio registra una reducción importante, mayor a los demás municipios, en el nivel de incidencia de la pobreza, entre 1998 y 2006. La hipótesis que se sostiene en este artículo es que dicha caída se asocia al derrame económico que genera el turismo, en especial interno. A efecto de comprobar dicha hipótesis, se realiza un contraste de diferencia de medias proporcionales, del municipio analizado respecto a los otros municipios del departamento, en lo que respecta al nivel de pobreza y su reducción. Los resultados no permiten rechazar la hipótesis formulada.

  13. Locally conformal symplectic manifolds

    Directory of Open Access Journals (Sweden)

    Izu Vaisman

    1985-01-01

    Full Text Available A locally conformal symplectic (l. c. s. manifold is a pair (M2n,Ω where M2n(n>1 is a connected differentiable manifold, and Ω a nondegenerate 2-form on M such that M=⋃αUα (Uα- open subsets. Ω/Uα=eσαΩα, σα:Uα→ℝ, dΩα=0. Equivalently, dΩ=ω∧Ω for some closed 1-form ω. L. c. s. manifolds can be seen as generalized phase spaces of Hamiltonian dynamical systems since the form of the Hamilton equations is, in fact, preserved by homothetic canonical transformations. The paper discusses first Hamiltonian vector fields, and infinitesimal automorphisms (i. a. on l. c. s. manifolds. If (M,Ω has an i. a. X such that ω(X≠0, we say that M is of the first kind and Ω assumes the particular form Ω=dθ−ω∧θ. Such an M is a 2-contact manifold with the structure forms (ω,θ, and it has a vertical 2-dimensional foliation V. If V is regular, we can give a fibration theorem which shows that M is a T2-principal bundle over a symplectic manifold. Particularly, V is regular for some homogeneous l. c. s, manifolds, and this leads to a general construction of compact homogeneous l. c. s, manifolds. Various related geometric results, including reductivity theorems for Lie algebras of i. a. are also given. Most of the proofs are adaptations of corresponding proofs in symplectic and contact geometry. The paper ends with an Appendix which states an analogous fibration theorem in Riemannian geometry.

  14. Indigeneity: global and local.

    Science.gov (United States)

    Merlan, Francesca

    2009-06-01

    The term indigenous, long used to distinguish between those who are "native" and their "others" in specific locales, has also become a term for a geocultural category, presupposing a world collectivity of "indigenous peoples" in contrast to their various "others." Many observers have noted that the stimuli for internationalization of the indigenous category originated principally from particular nation-states-Anglo-American settler colonies and Scandinavia. All, I argue, are relevantly political cultures of liberal democracy and weighty (in different ways) in international institutional affairs. However, international indigeneity has not been supported in any unqualified way by actions taken in the name of several nation-states that were among its main points of origin. In fact, staunch resistance to the international indigenous project has recently come from four of them. In 2007, the only four voting countries to reject the main product of international indigenist activity over the past 30 years, the Declaration on the Rights of Indigenous Peoples, were Australia, the United States, Canada, and New Zealand. In these locations, forms of "indigenous relationship" emerged that launched international indigeneity and that strongly influenced international perceptions of what "indigeneity" is and who "indigenous peoples" may be. Some other countries say the model of indigenous relationship that they see represented by the "establishing" set is inapplicable to themselves (but have nonetheless had to take notice of expanding internationalist indigenism). The apparently paradoxical rejection of the draft declaration by the establishing countries is consistent with the combination of enabling and constraining forces that liberal democratic political cultures offer.

  15. Local fiscal distress and investment efficiency of local SOEs

    Directory of Open Access Journals (Sweden)

    Xinxin Liao

    2014-06-01

    Full Text Available In this paper, we use A-share listed firms between 2002 and 2010 to investigate the relationship between local fiscal distress and the investment efficiency of local SOEs, along with the effect of corporate tax payments on this relationship. We find a positive relationship between the extent of local SOEs’ overinvestment and the fiscal distress of the corresponding local government where the enterprise and this relationship become stronger for firms that pay fewer taxes. The pattern of underinvestment among local SOEs was in contrast, and these relationships do not exist for non-SOEs or central SOEs. Moreover, we find that expanding a firm’s investment scale leads to an increase in total taxes paid, including income and turnover taxes, which further result in more local fiscal revenue. Overall, we conclude that local governments have an incentive to increase fiscal revenue when faced with fiscal distress by raising the investment scale of local SOEs and that the incentives and effects of such interventions appear to be stronger among firms that contribute less to local fiscal revenue.

  16. A Local Galilean Invariant Thermostat.

    Science.gov (United States)

    Groot, Robert D

    2006-05-01

    The thermostat introduced recently by Stoyanov and Groot (J. Chem. Phys. 2005, 122, 114112) is analyzed for inhomogeneous systems. This thermostat has one global feature, because the mean temperature used to drive the system toward equilibrium is a global average. The consequence is that the thermostat locally conserves energy rather than temperature. Thus, local temperature variations can be long-lived, although they do average out by thermal diffusion. To obtain a faster local temperature equilibration, a truly local thermostat must be introduced. To conserve momentum and, hence, to simulate hydrodynamic interactions, the thermostat must be Galilean invariant. Such a local Galilean invariant thermostat is studied here. It is shown that, by defining a local temperature on each particle, the ensemble is locally isothermal. The local temperature is obtained from a local square velocity average around each particle. Simulations on the ideal gas show that this local Nosé-Hoover algorithm has a similar artifact as dissipative particle dynamics:  the ideal gas pair correlation function is slightly distorted. This is attributed to the fact that the thermostat compensates fluctuations that are natural within a small cluster of particles. When the cutoff range rc for the square velocity average is increased, systematic errors decrease proportionally to rc(-)(3/2); hence, the systematic error can be made arbitrary small.

  17. Localized structure of Euglena bioconvection

    Science.gov (United States)

    Iima, Makoto; Shoji, Erika; Awazu, Akinori; Nishimori, Hiraku; Izumi, Shunsuke; Hiroshima University Collaboration

    2013-11-01

    Bioconvection of a suspension of Euglena gracilis, a photosensitive flagellate whose body length is approximately 50 micrometers, was experimentally studied. Under strong light intensity, Euglena has a negative phototaxis; they tend to go away from the light source. When the bright illumination is given from the bottom, a large scale spatio-temporal pattern is generated as a result of interaction between Euglena and surrounding flow. Recently, localized convection pattern had been reported, however, the generation process and interaction of the localized convection cells has not been analyzed. We performed experimental study to understand the localization mechanism, in particular, the onset of bioconvection and lateral localization behavior due to phototaxis. Experiments started from different initial condition suggests a bistability near the onset of the convection as binary fluid convection that also shows localized convection cells. Dynamics of localized convections cells, which is similar to the binary fluid convection case although the basic equations are not the same, is also reported.

  18. Local initiative extrapolated to nation

    DEFF Research Database (Denmark)

    Wittchen, Kim Bjarne; Kragh, Jesper; Brøgger, Morten

    In the municipality of Sønderborg, in the southern part of Jutland, there is a shining example initiated in 2007, ProjectZero, of a local initiative that have resulted in extensive energy savings in residential buildings and at the same time created local workplaces. The intension with the pilot...... is to investigate the possible energy reduction in Denmark if the same approach was made for the entire Danish building stock. Deployment of this methodology on national scale will not be straight forward as it requires strong local support. In Sønderborg the local business and clean-tech companies have strongly...... supported the project. Additionally, one of the driving forces has been the creation of something unique among the local residents and feeling to be able to create local unity. This cannot easily be made nationally. Never the less, playing with the idea about a nationwide dissemination will demonstrate...

  19. Global/Local Dynamic Models

    Energy Technology Data Exchange (ETDEWEB)

    Pfeffer, A; Das, S; Lawless, D; Ng, B

    2006-10-10

    Many dynamic systems involve a number of entities that are largely independent of each other but interact with each other via a subset of state variables. We present global/local dynamic models (GLDMs) to capture these kinds of systems. In a GLDM, the state of an entity is decomposed into a globally influenced state that depends on other entities, and a locally influenced state that depends only on the entity itself. We present an inference algorithm for GLDMs called global/local particle filtering, that introduces the principle of reasoning globally about global dynamics and locally about local dynamics. We have applied GLDMs to an asymmetric urban warfare environment, in which enemy units form teams to attack important targets, and the task is to detect such teams as they form. Experimental results for this application show that global/local particle filtering outperforms ordinary particle filtering and factored particle filtering.

  20. Locality of entangled polymer dynamics

    Science.gov (United States)

    Tsang, Chi Hang Boyce; Jiang, Lingxiang; Granick, Steve

    2014-03-01

    A combination of sparse and full fluorescence labeling of entangled actin solutions (filaments about 15 μm long at 1 mg/ml concentration) allowed us to probe both filament-scale polymer dynamics and effectively monomer dynamics. On the filament scale, the reptation tube idea of classical polymer physics works well. However, on a local scale comparable to mesh size, local tube width fluctuation becomes important. For the first time, the dependence of longitudinal diffusion on local tube width was quantified.

  1. Non-local cosmological evolutions

    Science.gov (United States)

    Carreras, M. Sanfrutos; Cembranos, J. A. R.

    2012-07-01

    The cosmological evolution of a non-local model is investigated. As it is standard in the early Universe, we assume the thermalization of the source of the Friedmann equation. In such a case, the non-local correction to the classic Einstein-Hilbert action can be locally represented by a non-standard thermal fluid. We give a particular realization of this idea by using the p-adic string model.

  2. Reversible Destruction of Dynamical Localization

    OpenAIRE

    Lignier, Hans; Chabé, Julien; Delande, Dominique; Garreau, Jean Claude; Szriftgiser, Pascal

    2005-01-01

    4 pages, 2 eps figures (color); Dynamical localization is a localization phenomenon taking place, for example, in the quantum periodically-driven kicked rotor. It is due to subtle quantum destructive interferences and is thus of intrinsic quantum origin. It has been shown that deviation from strict periodicity in the driving rapidly destroys dynamical localization. We report experimental results showing that this destruction is partially reversible when the deterministic perturbation that des...

  3. Local Government System in Japan

    Directory of Open Access Journals (Sweden)

    Vladimir V. Redko

    2016-12-01

    Full Text Available The article is devoted to the issues of the activities of the local government of Japan. Particular attention is drawn to the legal framework and the material basis for the functioning of local self-government bodies. The system of local self-government is considered as a special form of self-government with a specific functional and meaning; system of municipal management and delegation of authority, as well as features of interaction between civil and imperious levels. The allocation of the city with a special status, as well as the financial structure of the local government of Japan, is considered in detail.

  4. A Parameter Study of Localization

    Directory of Open Access Journals (Sweden)

    Sandor Stephen Mester

    1996-01-01

    Full Text Available Extensive work has been done on the vibration characteristics of perfectly periodic structures. Disorder in the periodic pattern has been found to lead to localization in one-dimensional periodic structures. It is important to understand localization because it causes energy to be concentrated near the disorder and may cause an overestimation of structural damping. A numerical study is conducted to obtain a better understanding of localization. It is found that any mode, even the first, can localize due to the presence of small imperfections.

  5. Local democracy in large municipalities

    DEFF Research Database (Denmark)

    Thuesen, Annette Aagaard

    2017-01-01

    development plans. Based on a concrete study of plan development by two sub-municipal local councils in two Danish municipalities, drawing upon insights from outcome-oriented deliberate democratic theory, this article provides recommendations for a potential structure for sub-municipal democracy in large......Municipal amalgamations in Denmark in 2007 led to concern for local rural democracy, as the number of politicians from rural areas dropped after the reform. To preserve rural democracy, local councils at the village level were established in some municipalities, and they have begun to prepare local...

  6. Local government autonomy and development of localities in Nigeria

    African Journals Online (AJOL)

    The topical issue of local government (LG) autonomy in Nigeria in relation to the development of the localities, the raison d'etre of LGs, has been examined in this paper. Proceeding from theoretical framework and conceptualizations for clearer understanding, the paper discusses some dominant autonomy issues.

  7. Globalization vs. localization: global food challenges and local sollutions

    NARCIS (Netherlands)

    Quaye, W.; Jongerden, J.P.; Essegbey, G.; Ruivenkamp, G.T.P.

    2010-01-01

    The objective of this study was to examine the effect of global-local interactions on food production and consumption in Ghana, and identify possible local solutions. Primary data were collected using a combination of quantitative-qualitative methods, which included focus group discussions and

  8. "Local" politics in Jakarta: anomaly from Indonesia's local politics?

    OpenAIRE

    Okamoto, Masaaki; Honna, Jun

    2014-01-01

    "This special issue attempts to go beyond short essays and conduct a deeper analysis of Jakarta’s local politics. Some of the contributions show the peculiarities of Jakartan politics, while others identify similarities with other local politics in Indonesia." (author's abstract)

  9. Local government autonomy and development of localities in Nigeria

    African Journals Online (AJOL)

    OSA IDEHEN

    Proceeding from theoretical framework and conceptualizations for clearer ... Introduction. The definition of local government (LG) by the Nigerian Federal Government leaves one with no iota of doubt that it is ... the substantial control of local governments (LGs) is aimed at staff, institutional and financial matters, among others.

  10. String-localized quantum fields and modular localization

    Energy Technology Data Exchange (ETDEWEB)

    Mund, J. [Juiz de Fora Univ., MG (Brazil). Dept. de Fisica; Schroer, B. [FU-Berlin, Berlin (Germany). Inst. fuer Theoretische Physik; Yngvason, J. [Erwin Schroedinger Institute for Mathematical Physics, Vienna (Austria)

    2005-12-15

    We study free, covariant, quantum (Bose) fields that are associated with irreducible representations of the Poincare group and localized in semi-infinite strings extending to spacelike infinity. Among these are fields that generate the irreducible representations of mass zero and infinite spin that are known to be incompatible with point-like localized fields. For the massive representation and the massless representations of finite helicity, all string-localized free fields can be written as an integral, along the string, of point-localized tensor or spinor fields. As a special case we discuss the string-localized vector fields associated with the point-like electromagnetic field and their relation to the axial gauge condition in the usual setting. (author)

  11. Tongue Twisters and Local Beliefs

    OpenAIRE

    Bkra shis bzang po

    2009-01-01

    O rgyan dban phyugs provides examples of tongue twisters and discusses local folk beliefs This collection of 77 audio files focuses on weddings and weddings speeches but also contains: folk tales, folk songs, riddles, tongue twisters, and local history from Bang smad Village and Ri sne Village, Bang smad Township, Nyag rong County World Oral Literature Project

  12. 'Global' norms and 'local' agency

    DEFF Research Database (Denmark)

    Björkdahl, Annika; Gusic, Ivan

    2015-01-01

    in post-conflict Kosovo provides the backdrop for the theoretical discussion that identifies friction in norm diffusion processes and the different agencies that are generated through encounters between global norms and local practices. We unpack the interplay between the 'global' and the 'local...

  13. Space-based RSS localization

    NARCIS (Netherlands)

    Havinga, Paul J.M.; Dil, B.J.

    2014-01-01

    The present invention relates to a method and a device for localization of a node having an unknown position. More in particular, the present invention relates 5 to a method and a device in which a mobile blind node is used to determine the position of a fixed blind node within a localization area,

  14. Is Local Community the Answer?

    DEFF Research Database (Denmark)

    Bruun, Ole; Olwig, Mette Fog

    2015-01-01

    This article critically examines claims that “local community” and “local/traditional knowledge” are vital contributions to safeguarding socio-economic stability and securing sustainable resource uses in times of stress. The empirical focus is on Central Vietnam, but the argument is relevant...

  15. Regional power and local ecologies

    DEFF Research Database (Denmark)

    Lawrence, D.; Philip, G.; Wilkinson, K.

    2017-01-01

    Archaeological data tend to be gathered at the local level: human agency also operates at this scale. By combining data from multiple surveys conducted within a larger area, it is possible to use local datasets to obtain a perspective on regional trends in settlement, population, and human activi...

  16. Global Policies and Local Practice

    DEFF Research Database (Denmark)

    Rasche, Andreas

    2012-01-01

    networks that are embedded in a wider global network, I argue that tighter couplings (within local networks) and looser couplings (between local networks) coexist. Second, I suggest that this coexistence of couplings enables MSIs to generate policy outcomes which address the conditions of a transnational...

  17. Global Policies and Local Practice

    DEFF Research Database (Denmark)

    Rasche, Andreas; Gilbert, Dirk Ulrich

    networks that are embedded in a wider global network, I argue that tighter couplings (within local networks) and looser couplings (between local networks) coexist. Second, I suggest that this coexistence of couplings enables MSIs to generate policy outcomes which address the conditions of a transnational...

  18. A geometrical perspective on localization

    NARCIS (Netherlands)

    Dulman, S.O.; Baggio, A.; Havinga, Paul J.M.; Langendoen, K.G.; Zhang, Ying; Ye, Yinyu

    2008-01-01

    A large number of localization algorithms for wireless sensor networks (WSNs) are evaluated against the Cramer-Rao Bound (CRB) as an indicator of how good the algorithm performs. The CRB defines the lower bound on the precision of an unbiased localization estimator. The CRB concept, borrowed from

  19. Fine-scale geographic variation in photosynthetic-related traits of Picea glauca seedlings indicates local adaptation to climate.

    Science.gov (United States)

    Benomar, Lahcen; Lamhamedi, Mohammed S; Villeneuve, Isabelle; Rainville, André; Beaulieu, Jean; Bousquet, Jean; Margolis, Hank A

    2015-08-01

    Climate-related variations in functional traits of boreal tree species can result both from physiological acclimation and genetic adaptation of local populations to their biophysical environment. To improve our understanding and prediction of the physiological and growth responses of populations to climate change, we studied the role of climate of seed origin in determining variations in functional traits and its implications for tree improvement programs for a commonly reforested boreal conifer, white spruce (Picea glauca (Moench) Voss). We evaluated growth, root-to-shoot ratio (R/S), specific leaf area (SLA), needle nitrogen (N(mass)), total non-structural carbohydrates (NSC) and photosynthetic traits of 3-year-old seedlings in a greenhouse experiment using seed from six seed orchards (SO) representing the different regions where white spruce is reforested in Québec. Height and total dry mass (TDM) were positively correlated with photosynthetic capacity (A(max)), stomatal conductance (g(s)) and mesophyll conductance (g(m)). Total dry mass, but not height growth, was strongly correlated with latitude of seed origin (SO) and associated climate variables. A(max), g(s), g(m) and more marginally, photosynthetic nitrogen-use efficiency (PNUE) were positively associated with the mean July temperature of the SO, while water use efficiency (WUE) was negatively associated. Maximum rates of carboxylation (V(cmax)), maximum rates of electron transport (J(max)), SLA, N(mass), NSC and R/S showed no pattern. Our results did not demonstrate a higher Amax for northern seed orchards, although this has been previously hypothesized as an adaptation mechanism for maintaining carbon uptake in northern regions. We suggest that gs, gm, WUE and PNUE are the functional traits most associated with fine-scale geographic clines and with the degree of local adaptation of white spruce populations to their biophysical environments. These geographic patterns may reflect in situ adaptive genetic

  20. Strategy for Developing Local Chicken

    Directory of Open Access Journals (Sweden)

    Sofjan Iskandar

    2006-12-01

    Full Text Available Chicken industry in Indonesia offer jobs for people in the village areas . The balance in development industry of selected and local chicken has to be anticipated as there has been threat of reducing importation of grand parent stock of selected chicken due to global avian influenza . In the mean time, high appreciation to the local chicken has been shown by the existence of local chicken farms in the size of business scale . For local chicken business, the government has been built programs, projects, and infrastructures, although the programs and projects were dropped scattered in to several institutions, which were end up with less significant impact to the people. Therefore, it is the time that the government should put more efforts to integrate various sources . focusing in enhancing local chicken industry .

  1. Compact Local Directional Texture Pattern for Local Image Description

    Directory of Open Access Journals (Sweden)

    Hui Zeng

    2015-01-01

    Full Text Available This paper presents an effective local image feature region descriptor, called CLDTP descriptor (Compact Local Directional Texture Pattern, and its application in image matching and object recognition. The CLDTP descriptor encodes the directional and contrast information in a local region, so it contains the gradient orientation information and the gradient magnitude information. As the dimension of the CLDTP histogram is much lower than the dimension of the LDTP histogram, the CLDTP descriptor has higher computational efficiency and it is suitable for image matching. Extensive experiments have validated the effectiveness of the designed CLDTP descriptor.

  2. An Open Localization and Local Communication Embodied Sensor

    Directory of Open Access Journals (Sweden)

    Alvaro Gutiérrez

    2008-11-01

    Full Text Available In this paper we describe a localization and local communication system which allows situated agents to communicate locally, obtaining at the same time both the range and the bearing of the emitter without the need of any centralized control or any external reference. The system relies on infrared communications with frequency modulation and is composed of two interconnected modules for data and power measurement. Thanks to the open hardware license under which it is released, the research community can easily replicate the system at a low cost and/or adapt it for applications in sensor networks and in robotics.

  3. Local Anesthetic-Induced Neurotoxicity

    Directory of Open Access Journals (Sweden)

    Mark Verlinde

    2016-03-01

    Full Text Available This review summarizes current knowledge concerning incidence, risk factors, and mechanisms of perioperative nerve injury, with focus on local anesthetic-induced neurotoxicity. Perioperative nerve injury is a complex phenomenon and can be caused by a number of clinical factors. Anesthetic risk factors for perioperative nerve injury include regional block technique, patient risk factors, and local anesthetic-induced neurotoxicity. Surgery can lead to nerve damage by use of tourniquets or by direct mechanical stress on nerves, such as traction, transection, compression, contusion, ischemia, and stretching. Current literature suggests that the majority of perioperative nerve injuries are unrelated to regional anesthesia. Besides the blockade of sodium channels which is responsible for the anesthetic effect, systemic local anesthetics can have a positive influence on the inflammatory response and the hemostatic system in the perioperative period. However, next to these beneficial effects, local anesthetics exhibit time and dose-dependent toxicity to a variety of tissues, including nerves. There is equivocal experimental evidence that the toxicity varies among local anesthetics. Even though the precise order of events during local anesthetic-induced neurotoxicity is not clear, possible cellular mechanisms have been identified. These include the intrinsic caspase-pathway, PI3K-pathway, and MAPK-pathways. Further research will need to determine whether these pathways are non-specifically activated by local anesthetics, or whether there is a single common precipitating factor.

  4. Local cases of institutional entrepreneurship:

    DEFF Research Database (Denmark)

    Gretzinger, Susanne

    2018-01-01

    Population ageing and population decline are two contemporary phenomena that imply a tremendous transformation of local markets across many European regions and challenge their economic growth and development in the longer run. In such contexts of market change and, perhaps, crisis, institutional....... In this chapter, the focus is on the initiatives of local “change agents” that will be described as local cases of institutional entrepreneurship in the context of the contemporary demographic challenges. The chapter portrays bottom-up initiatives in Germany that are set up by agents who systematically work...

  5. Human localization and performance measures

    DEFF Research Database (Denmark)

    Hammershøi, Dorte

    2009-01-01

    Localization is for some scenarios and situations vital for the success of hearing, e. g. when listening out single sources in multi-source environments, or when navigating primarily by audible information. It is therefore of interest to know the limits of the human localization capacity, and its...... dependence on e.g. direction and distance. When addressed in laboratory experiments, the significance of other modalities are controlled in different ways, yet figures will inherently reflect properties of the test situation as well. The present paper will discuss the methodologies of localization...

  6. Building Local Governance in Denmark

    DEFF Research Database (Denmark)

    Damgaard, Bodil

    Local partnerships have become an important strategic element in active social policy in Denmark. In order to progress towards the parallel objectives of increasing employment rates and creating a more open and inclusive labour market, improving local collaboration is considered paramount....... Accordingly, the municipalities (which in Denmark are in charge of implementing most social policies and carry a large share of the financial burdens) have since 1999 been obliged to have a local coordination committee. Law determines the composition, the competences, and the main tasks of these committees...

  7. The Local-Cosmopolitan Scientist

    Directory of Open Access Journals (Sweden)

    Barney G. Glaser, Ph.D., Hon. Ph.D.

    2011-12-01

    Full Text Available In contrast to previous discussions in the literature treating cosmopolitan and local as two distinct groups of scientists, this paperi demonstrates the notion of cosmopolitan and local as a dual orientation of highly motivated scientists. This dual orientation is derived from institutional motivation, which is a determinant of both high quality basic research and accomplishment of non-research organizational activities. The dual orientation arises in a context of similarity of the institutional goal of science with the goal of the organization; the distinction between groups of locals and cosmopolitans derives from a conflict between two goals.

  8. Morbidity, mortality and local anaesthesia.

    Science.gov (United States)

    Malamed, S F

    1999-01-01

    Two cases of local anaesthetic overdose and death are described. The patients, a four-year-old child and a 68-year old female, received local anaesthetic doses greatly in excess of those recommended. Their overdose reactions are described as well as subsequent management. The paper reviews the causes of local anaesthetic overdose, its signs and symptoms, and the recommended management of these reactions. Specific discussion as to the cause of death of these two patients and of the means to prevent such occurrences in the future concludes the paper.

  9. Buying Local or Imported Goods?

    DEFF Research Database (Denmark)

    Ayob, Abu H.; Hussain, Wan Mohd Hirwani Wan

    2016-01-01

    This study attempts to profile non-income consumers by examining their decisions to buy local or imported products. Hypotheses were drawn from discussions on the comparative advantages of advanced and developing countries, as well as the effects of a product’s country-of-origin on customers...... encourage students to buy local products because they are perceived as being less expensive. Also, students who receive scholarships are more likely to buy local products than self-sponsored students. This research offers insights into ex-ante purchasing behavior in developing countries particularly among...

  10. Quantum theory and local causality

    CERN Document Server

    Hofer-Szabó, Gábor

    2018-01-01

    This book summarizes the results of research the authors have pursued in the past years on the problem of implementing Bell's notion of local causality in local physical theories and relating it to other important concepts and principles in the foundations of physics such as the Common Cause Principle, Bell's inequalities, the EPR (Einstein-Podolsky-Rosen) scenario, and various other locality and causality concepts. The book is intended for philosophers of science with an interest in the formal background of sciences, philosophers of physics and physicists working in foundation of physics.

  11. GOBIERNO LOCAL: AUTONOMIA Y GOBERNABILIDAD

    OpenAIRE

    José Vargas Hernández

    2011-01-01

    Este trabajo, tiene como objetivo analizar las funciones del nuevo gobierno local para dar respuesta a las demandas sociales, promover el desarrollo y regular los nuevos servicios públicos. A partir de una delimitación de los conceptos de soberanía y autonomía del nuevo gobierno local, se reconfigura una nueva estructura de gobernabilidad de los gobiernos locales que implica una mayor participación ciudadana en los procesos de toma de decisiones y la formulación de las políticas públicas, m...

  12. High capacity fiber optic sensor networks using hybrid multiplexing techniques and their applications

    Science.gov (United States)

    Sun, Qizhen; Li, Xiaolei; Zhang, Manliang; Liu, Qi; Liu, Hai; Liu, Deming

    2013-12-01

    Fiber optic sensor network is the development trend of fiber senor technologies and industries. In this paper, I will discuss recent research progress on high capacity fiber sensor networks with hybrid multiplexing techniques and their applications in the fields of security monitoring, environment monitoring, Smart eHome, etc. Firstly, I will present the architecture of hybrid multiplexing sensor passive optical network (HSPON), and the key technologies for integrated access and intelligent management of massive fiber sensor units. Two typical hybrid WDM/TDM fiber sensor networks for perimeter intrusion monitor and cultural relics security are introduced. Secondly, we propose the concept of "Microstructure-Optical X Domin Refecltor (M-OXDR)" for fiber sensor network expansion. By fabricating smart micro-structures with the ability of multidimensional encoded and low insertion loss along the fiber, the fiber sensor network of simple structure and huge capacity more than one thousand could be achieved. Assisted by the WDM/TDM and WDM/FDM decoding methods respectively, we built the verification systems for long-haul and real-time temperature sensing. Finally, I will show the high capacity and flexible fiber sensor network with IPv6 protocol based hybrid fiber/wireless access. By developing the fiber optic sensor with embedded IPv6 protocol conversion module and IPv6 router, huge amounts of fiber optic sensor nodes can be uniquely addressed. Meanwhile, various sensing information could be integrated and accessed to the Next Generation Internet.

  13. Local Climatological Data (LCD) Publication

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Local Climatological Data (LCD) contains summaries from major airport weather stations that include a daily account of temperature extremes, degree days,...

  14. Local Authority and Town Planning.

    Science.gov (United States)

    Duder, Bruce

    1987-01-01

    Provides an overview and definition of local authority and town planning in New Zealand. Demonstrates the relevance of planning matters to the teaching of geography. Reviews objectives of geography and specific planning methods used in several districts. (BR)

  15. Lunar Localization System (LLS) Project

    Data.gov (United States)

    National Aeronautics and Space Administration — In support of NASA's vision for space, the goal of this project is to research and prototype a multi-component localization system which uses radiometry and vision...

  16. GOBIERNO LOCAL: AUTONOMIA Y GOBERNABILIDAD

    Directory of Open Access Journals (Sweden)

    José Vargas Hernández

    2011-01-01

    Full Text Available Este trabajo, tiene como objetivo analizar las funciones del nuevo gobierno local para dar respuesta a las demandas sociales, promover el desarrollo y regular los nuevos servicios públicos. A partir de una delimitación de los conceptos de soberanía y autonomía del nuevo gobierno local, se reconfigura una nueva estructura de gobernabilidad de los gobiernos locales que implica una mayor participación ciudadana en los procesos de toma de decisiones y la formulación de las políticas públicas, mediante la facilitación de procesos de descentralización de funciones y mecanismos coordinadores de servicios públicos. Finalmente se analizan las implicaciones en la gobernabilidad de la ingeniería social del nuevo gobierno local.

  17. Wallah. Indexing the new locality

    DEFF Research Database (Denmark)

    Skovse, Astrid Ravn

    This paper aims to add new, empirically based insights to the understanding of the dynamics by which linguistic features come to index locality. It does so through examining the indexicalities of the term wallah among adolescents living in the suburban, multi-ethnic Danish neighborhood Vollsmose....... The paper shows how the term wallah, by being emblematic of the enregistered voices of somewhat competing, locally constructed characterological figures (Agha 2005), comes to serve as an index of highly specific kinds of locality. The data comes from an experimental mapping method tapping into informants...... in a wide range of multi-ethnic settings in Scandinavia – wallah is nevertheless capable of indexing both local and supralocal sociolinguistic scales at once, reflecting the multiscalarity of the “new localities” of globalization (Blommaert 2010). By considering the possibility of features indexing a range...

  18. Local Area Defense (LAD) Demonstration

    National Research Council Canada - National Science Library

    Mackenzie, Colin F

    2004-01-01

    This pilot program is funded by the Army Medical Department (AMEDD) to demonstrate a real-time detection and rapid response system for local area defense using the University of Maryland Baltimore (UMB...

  19. Simulating the Local Interstellar Medium

    Science.gov (United States)

    Slavin, Jonathan D.

    2017-05-01

    The Local Interstellar Medium (LISM) in many ways exemplifies the diffuse ISM of the Galaxy and star forming galaxies in general. Though devoid of molecular gas, it includes warm gas, hot, supernova-heated gas and even cold neutral gas clouds. The complex of local interstellar clouds (CLIC), which includes the cloud that directly surrounds the heliosphere, is made up of warm, low density, partially ionized gas. These clouds have somehow come to be embedded within the hot Local Bubble, apparently having survived the passage of the shock that heated the gas. We describe our attempts to understand this surprising situation and to explain the thermal and ionization state of the CLIC as well as the state of the Local Bubble via hydrodynamical and photoionization modeling. We also discuss the broader implications of our results for the interaction of the different temperature-density phases in the diffuse ISM of galaxies.

  20. Local Water Conflict and Cooperation

    DEFF Research Database (Denmark)

    Hermann, Roberto Rivas; Hooper, Catherine; Munk Ravnborg, Helle

    2011-01-01

    In 2007 the Danish Institute for International Studies (DIIS) launched the research programme “Competing for Water: Understanding conflict and cooperation in local water governance”. Along with partners in five developing countries (Bolivia, Mali, Nicaragua, Vietnam and Zambia), the programme aims...... to contribute to “sustainable local water governance in support of the rural poor and otherwise disadvantaged groups in developing countries by improving the knowledge among researchers and practitioners of the nature, extent and intensity of local water conflict and cooperation and their social, economic...... al, 2007; Nguyen, 2007; Mweemba, C.E. 2007). The purpose of these overviews was to position the research findings on the extent and nature of local-level water-related conflict and cooperation in the context of ongoing efforts to improve the policy, legal and administrative water governance framework...