Project size, as measured by the amount of investment required, is a relevant parameter to be used in project selection. The evaluation of a project portfolio must consider the variety of project sizes that may be met...
详细信息
ISBN:
(纸本)9781509002078
Project size, as measured by the amount of investment required, is a relevant parameter to be used in project selection. The evaluation of a project portfolio must consider the variety of project sizes that may be met, so that a proper model should be adopted to describe that variety, especially for its use in simulation. In this paper, a log-normal probability model is suggested to describe the dispersion of project sizes within a project portfolio. The model is obtained on the basis of two real datasets spanning over ten years of observations, and after comparison with competing Gamma and Pareto models. The parameters of the log-normal model are provided as resulting from the best-fit procedure, and indications are also given for the values to use in a simulation study.
This paper focuses on novel filtering architectures for LTE-band transmit and receive RF-filters. For the first time, it is demonstrated that advanced filtering components with low insertion loss (2.8-4.9 dB) and larg...
详细信息
This paper focuses on novel filtering architectures for LTE-band transmit and receive RF-filters. For the first time, it is demonstrated that advanced filtering components with low insertion loss (2.8-4.9 dB) and large attenuation stopbands (25-50 dB) can be created by series-cascaded absorptive bandstop filters with quality factors even as low as 12-45. Transmit and receive filter modules for LTE-band 1 duplex circuits are shown. Lumped-element absorptive bandstop filters with the highest reported Q of 43 at 2 GHz are presented. Tunability of the presented filter arc hitectures is also discussed.
A spatial phaser based on all-pass metasurfaces using Interconnected dielectric resonators is proposed for real-time-analog signal processing (R-ASP). The structure is simple to fabricate and is constructed from a sin...
详细信息
A spatial phaser based on all-pass metasurfaces using Interconnected dielectric resonators is proposed for real-time-analog signal processing (R-ASP). The structure is simple to fabricate and is constructed from a single dielectric layer using standard laser hole drilling processing. Its all-pass transmission response along with its transmission delay characteristics are also demonstrated using rigorous coupled-wave analysis (RCWA).
A method to produce multiple transmission zeros (TZs) is applied to design sharp-rejection planar highpass filters (HPFs) and dual-passband filters (BPFs). It consists of adding an external transversal cell to a basic...
详细信息
A method to produce multiple transmission zeros (TZs) is applied to design sharp-rejection planar highpass filters (HPFs) and dual-passband filters (BPFs). It consists of adding an external transversal cell to a basic filter to create TZs in its response without damaging its in-band amplitude and group-delay variation. Thus, contrary to other filter design techniques, in-band requisites and stopband TZ creation can be separately addressed in the entire filter synthesis process. Such technique could have great potential in other technologies, such as waveguide filters for satellite communications, in which low in-band group-delay variation and adjustable high selectivity are necessary. Measurements for a microstrip HPF and simulations for a stripline dual-band BPF are shown.
The tight binding approach is adopted for efficient numerical analysis of a certain class of photonic crystals that have similarities to their semiconductor counterparts. A systematic approach is proposed to replicate...
详细信息
The tight binding approach is adopted for efficient numerical analysis of a certain class of photonic crystals that have similarities to their semiconductor counterparts. A systematic approach is proposed to replicate the band structure of a solid-state material in a photonic crystal.
An array of leaky-wave antennas (LWA) fed with a dispersive feeding network is proposed to decompose, in real-time, the spectral components of a broadband signal in two dimensions of space. Compared to typical real-ti...
详细信息
An array of leaky-wave antennas (LWA) fed with a dispersive feeding network is proposed to decompose, in real-time, the spectral components of a broadband signal in two dimensions of space. Compared to typical real-time decomposition systems, which are restricted to one-dimensional decomposition, such a two-dimensional system can analyze faster signals and thus provide higher frequency resolution. The operation of the proposed structure is demonstrated using array-factor theory.
A magnet-less nonreciprocal metasurface (MNMs) exhibiting enhanced transmission is presented. The metasurface is constituted of a 2D periodic array of a stacked annular pair of slots loaded with semiconductor-based un...
详细信息
A magnet-less nonreciprocal metasurface (MNMs) exhibiting enhanced transmission is presented. The metasurface is constituted of a 2D periodic array of a stacked annular pair of slots loaded with semiconductor-based unidirectional components sandwiching a dielectric slab spacer. The reflection and transmission dyadics of the metamaterial structure are computed using transmission line modeling with single-layer annular slot impedance dyadic. A parametric study is conducted in terms of the spacer permittivity and thickness to achieve enhanced transmission. Possibility of designing total transmission or total reflection magnet-less nonreciprocal metasurfaces is discussed.
An adaptive Dispersion Code Multiple Access (DCMA) system is proposed and demonstrated using numerical calculations. Compared to conventional static DCMA, where channels between access points are fixed unless adaptive...
详细信息
An adaptive Dispersion Code Multiple Access (DCMA) system is proposed and demonstrated using numerical calculations. Compared to conventional static DCMA, where channels between access points are fixed unless adaptive phasers are used, the proposed system employs a base-station which allows users with distinct but fixed phasers to form arbitrary adaptive channels between the access points. The base-station first records the channel responses in the sounding stage, and then uses this information to route the data between arbitrary user pairs in the communication stage.
We propose a new automatic procedure to generate hybrid meshes to simulate turbulent flows for wind farm design and management. In particular, numerical modeling of wind farms involves a RANS simulation of the Atmosph...
详细信息
We propose a new automatic procedure to generate hybrid meshes to simulate turbulent flows for wind farm design and management. In particular, numerical modeling of wind farms involves a RANS simulation of the Atmospheric Boundary Layer (ABL) flow and modeling the turbines using the actuator disc theory. Therefore, the generated meshes have to fulfill several geometrical requirements to answer to the different modeling features. They must: capture the topography features that can influence the wind flow; have a boundary layer close to the terrain to resolve the ABL; be conformally adapted to the disc (turbine) to simulate the turbine effects on the wind flow; be adapted around the disc to capture the wake effect; and present a smooth mesh size transition around the disc to conform the mesh size of the ABL mesh, in which the turbines are immersed. We highlight that the mesh generation procedure is fully automatic once given the mesh size, a topography description, the wind inflow direction, a list of turbine insertion points, and the turbine models. To illustrate the applicability of the proposed procedure, we present two wind farm cases: an offshore wind farm mesh where we illustrate the computed wind deficit, and an onshore farm assimilating real topography data.
Autonomous services discovery, composition and execution is an important problem in the Machine-to-Machine field. Achieving this objective requires addressing several issues: a) how to describe in a machine-understand...
详细信息
Autonomous services discovery, composition and execution is an important problem in the Machine-to-Machine field. Achieving this objective requires addressing several issues: a) how to describe in a machine-understandable format which operations and functionalities an object is able to perform;b) how to represent the interfaces in unambiguous way and allow two or more machines to understand the data exchanged with each other;c) how to make a machine able to aggregate services in order to execute a specific task. Narrowing the domain just to REST APIs, we propose to semantically describe APIs (exposed by objects or web servers) using RESTdesc descriptions and to use JSON-LD as data exchange format. In order to illustrate the straightforward services composition and invocation process, we have implemented a smart client able to generate and execute plans (sequences of HTTP requests) that satisfy the set of operations which should be done for ensuring ideal environmental conditions to plants in a garden.
暂无评论