High speed fiber optics local area networks: Design and implementation

The design of high speed local area networks (HSLAN) for communication among distributed devices requires solving problems in three areas: (1) the network medium and its topology; (2) the medium access control; and (3) the network interface. Considerable progress has been made in all areas. Accomplishments are divided into two groups according to their theoretical or experimental nature. A brief summary is given in Section 2, including references to papers which appeared in the literature, as well as to Ph.D. dissertations and technical reports published at Stanford University

Embedding Requirements within the Model Driven Architecture

The Model Driven Architecture (MDA) brings benefits to software development, among them the potential for connecting software models with the business domain. This paper focuses on the upstream or Computation Independent Model (CIM) phase of the MDA. Our contention is that, whilst there are many models and notations available within the CIM Phase, those that are currently popular and supported by the Object Management Group (OMG), may not be the most useful notations for business analysts nor sufficient to fully support software requirements and specification. Therefore, with specific emphasis on the value of the Business Process Modelling Notation (BPMN) for business analysts, this paper provides an example of a typical CIM approach before describing an approach which incorporates specific requirements techniques. A framework extension to the MDA is then introduced; which embeds requirements and specification within the CIM, thus further enhancing the utility of MDA by providing a more complete method for business analysis

Design and implementation of interface units for high speed fiber optics local area networks and broadband integrated services digital networks

The design and implementation of interface units for high speed Fiber Optic Local Area Networks and Broadband Integrated Services Digital Networks are discussed. During the last years, a number of network adapters that are designed to support high speed communications have emerged. This approach to the design of a high speed network interface unit was to implement package processing functions in hardware, using VLSI technology. The VLSI hardware implementation of a buffer management unit, which is required in such architectures, is described

Nonequilibrium plasmons with gain in graphene

Graphene supports strongly confined transverse-magnetic sheet plasmons whose spectral characteristics depend on the energetic distribution of Dirac particles. The question arises whether plasmons can become amplified when graphene is pumped into a state of inversion. In establishing a theory for the dynamic non-equilibrium polarizability, we are able to determine the exact complex-frequency plasmon dispersion of photo-inverted graphene and study the impact of doping, collision loss, and temperature on the plasmon gain. We calculate the spontaneous emission spectra and carrier recombination rates self-consistently and compare the results with approximations based on Fermi's golden rule. Our results show that amplification of plasmons is possible under realistic conditions but inevitably competes with ultrafast spontaneous emission, which for intrinsic graphene, is a factor 5 faster than previously estimated. This work casts new light on the nature of non-equilibrium plasmons and may aid the experimental realization of active plasmonic devices based on graphene.Comment: 17 pages, 7 figures, published in PR

Sustainable Tourism Marketing Strategies at UNESCO World Heritage Sites

Designation as a United Nations Educational Scientific and Cultural Organization (UNESCO) World Heritage site has a significant impact on the tourism development and sustainability of a site, city, region or country. World Heritage sites bring a certain level of prestige and international recognition, but they also have an impact on the local communities as they impact day to day life and rituals of the residents. Several paradigms exist in evaluating the success of a UNESCO World Heritage site. This paper specifically examines how marketing strategies bolster sustainable tourism efforts

Advances in Surgical and Anesthetic Techniques for Cochlear Implantation

Cochlear implantation (CI) is usually performed under general anesthesia using the classic surgical approach, the mastoidectomy posterior tympanotomy approach (MPTA), which was originally described by William House in 1961. Many alternative surgical approaches have been described for CI. Robotic image-guided cochlear implantation has also been described as a new advance in CI. Also, in some situations, CI can be performed under conscious sedation with local anesthesia (CS-LA) instead of general anesthesia (GA). With the ongoing advance in CI devices and surgical techniques, CI surgery nowadays could preserve hearing in ears with preoperative residual hearing. This chapter describes different approaches and techniques in CI surgery, whether classic or alternative technique, with special attention to advantages and disadvantages of each approach or technique. Also this chapter describes, in surgical points of view, the anesthetic techniques in CI, whether GA or CS-LA, with focus on indications, advantages, and disadvantages of CS-LA in CI