Search results for "Simulation"

Assessment of the Usability and Accuracy of the Simplified One-Diode Models for Photovoltaic Modules

2016

Models for photovoltaic (PV) cells and panels, based on the diode equivalent circuit, have been widely used because they are effective tools for system design. Many authors have presented simplified one-diode models whose three or four parameters are calculated using the data extracted from the datasheets issued by PV panel manufactures and adopting some simplifying hypotheses and numerical solving techniques. Sometimes it may be difficult to make a choice among so many models. To help researchers and designers working in the area of photovoltaic systems in selecting the model that is fit for purpose, a criterion for rating both the usability and accuracy of simplified one-diode models is p…

WT Type 4 Benchmarks for IEC 61400-27-1

2019

Since several years there has been a constant effort at international level for the standardization and the validation of different types of wind turbine (WT) dynamic models. The paper focuses on the IEC 61400-27-1 type 4 model, proposing and fully describing two benchmark systems for the assessment of dynamic performance. The first system is a simple setup and it is designed to specifically assess the transient response of the WT controls. The second system is based on the IEEE 9-bus test system, and it is a multi-machine configuration allowing for the inclusion of the typical power system dynamics of synchronous machines and corresponding primary regulators. System configurations, models …

Capacity and Energy-Consumption Optimization for the Cluster-Tree Topology in IEEE 802.15.4

2011

International audience; 802.15.4 proposes to use a cluster-tree hierar- chy to organize the transmissions in Wireless Sensor Networks. In this letter, we propose a framework to analyze formally the capacity and the energy consumption of this structure. We derive a Mixed Integer Linear Programming (MILP) formulation to obtain a topology compliant with the standard. This formulation provides the optimal solution for the network capacity: this con- stitutes an upper bound for any distributed algorithms permitting to construct a cluster-tree. This framework can also be used to evaluate the capacity and to compare quantitatively different cluster-tree algorithms.

Salvador Beltran, F., Herrando, S., Estreder, V., Ferreres, D., Adell, M. A., i Ruiz-Soler, M. (2011). A language shift simulation based on cellular …

2016

Identifying Geographic Terms within Natural Language Text

2008

Masteroppgave i informasjons- og kommunikasjonsteknologi 2008 – Universitetet i Agder, Grimstad The huge amount of textual data available in digital form in today’s world increases the need for methods that facilitate ease of access and navigability. Automatic extraction of keywords from text bodies is one promising approach. However, the relevance of keywords are context dependent, and extracting relevant keywords often requires a semantic analysis, simply because words may have different meanings in different contexts. It is well-known that resolving such word sense ambiguity automatically can be very challenging. When the topic of interest is geographic information, important keywords wo…

WLAN 802.11 b/g interference into ZigBee networks

2008

Masteroppgave i informasjons- og kommunikasjonsteknologi 2008 – Universitetet i Agder, Grimstad ZigBee network as a low rate wireless personal area network (LR-WPANs) developed very fast nowadays. Since both ZigBee network and WLAN (802.11b/g) operate in the 2.4GHz unlicensed industrial scientific medical (ISM) frequency band, signal interference is possible to exist and result in signal degradation when devices are collocated in the same environment. This thesis analyzes, simulates and measures the interference and evaluates ZigBee network performance under the WLAN interference in terms of Packet Error Rate (PER) and Packet Loss Ratio (PLR). And the investigation emphasis of this thesis i…

Accurate Measurement and Visualization of Traffic Load in IEEE 802.11 WLANs

2008

Masteroppgave i informasjons- og kommunikasjonsteknologi 2008 – Universitetet i Agder, Grimstad Wireless Local Area Networks (WLANs) based on the IEEE 802.11 standard are getting very popular these days, due to their support for new multimedia services and VoIP, and because WLANs are appearing on more and more small devices. This causes a steadily increasing load and becomes a challenge to network administrators who want to make their WLANs run efficiently and to keep the users satisfied. This Master thesis addresses the lack of efficient and affordable monitoring tools for those running WLANs, by developing an accurate method and for the visualization of traffic patterns and bandwidth util…

Modelling of the Universe : Simulation of the GPS (The Global Positioning System)

2007

Masteroppgave i informasjons- og kommunikasjonsteknologi 2007 – Høgskolen i Agder, Grimstad ParAbel is a project at Agder University College aims at mathematics and physics on Internet. One of the sub projects named SimReal [2] (Simulation in ‘Realfag’), which currently aims at simulating behaviours and properties of universe for both mathematics and physics studying. This project focuses on simulation of the GPS which is one sub task in SimReal. In this paper, on the one hand, we will set up a GPS simulation model and use it to be a teaching material for learning mathematics and physics. On the other hand, by testing the simulation model among the college students, we will discuss about th…

A novel framework for MR image segmentation and quantification by using MedGA

2019

BACKGROUND AND OBJECTIVES: Image segmentation represents one of the most challenging issues in medical image analysis to distinguish among different adjacent tissues in a body part. In this context, appropriate image pre-processing tools can improve the result accuracy achieved by computer-assisted segmentation methods. Taking into consideration images with a bimodal intensity distribution, image binarization can be used to classify the input pictorial data into two classes, given a threshold intensity value. Unfortunately, adaptive thresholding techniques for two-class segmentation work properly only for images characterized by bimodal histograms. We aim at overcoming these limitations and…

A plant-wide energy model for wastewater treatment plants: application to anaerobic membrane bioreactor technology

2016

[EN] The aim of this study is to propose a detailed and comprehensive plant-wide model for assessing the energy demand of different wastewater treatment systems (beyond the traditional activated sludge) in both steady- and unsteady-state conditions. The proposed model makes it possible to calculate power and heat requirements (W and Q, respectively), and to recover both power and heat from methane and hydrogen capture. In order to account for the effect of biological processes on heat requirements, the model has been coupled to the extended version of the BNRM2 plant-wide mathematical model, which is implemented in DESSAS simulation software. Two case studies have been evaluated to assess t…