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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

A Framework for Simplified Residential Energy Consumption Assessment towards Developing Performance Prediction Models for Retrofit Decision-Making

Durak, Tolga 15 November 2011 (has links)
This research proposes to simplify the energy consumption assessment for residential homes while building the foundation towards the development of prediction tools that can achieve a credible level of accuracy for confident decision making. The energy consumption assessment is based on simplified energy consumption models. The energy consumption analysis uses a reduced number of energy model equations utilizing a critical, limited set of parameters. The results of the analysis are used to develop the minimum set of consumption influence parameters with predicted effects for each energy consumption domain. During this research study, multiple modeling approaches and occupancy scenarios were utilized according to climate conditions in Blacksburg, Virginia. As a part of the analysis process, a parameter study was conducted to: develop a comprehensive set of energy consumption influence parameters, identify the inter-relationships among parameters, determine the impact of energy consumption influence parameters in energy consumption models, and classify energy consumption influence parameters under identified energy consumption domains. Based on the results of the parameter study, a minimum set of parameters and energy consumption influence matrices were developed. This research suggests the minimum set of parameters with predicted effects to be used during the development of the simplified baseline energy consumption model. / Ph. D.
2

Parameter Importance of an Analytical Model for Transport in the Vadose Zone

Bushnell, Tanner Hans 14 March 2007 (has links) (PDF)
The American Society of Testing and Materials (ASTM) has established a three tier risk-based corrective action (RBCA) program for cleaning up petroleum release sites, which is supported by the Environmental Protection Agency. RBCA programs make the cleanup of spill sites more efficient by requiring additional site information only when a more accurate risk assessment is needed. For spill sites that do not pass the first tier general assessment, a Tier 2 evaluation involving site specific information and screening level models to assess the potential risk must be conducted. Screening level models generally require site specific input parameters. To increase efficiency it would be helpful to know which parameters have large affects on model output and which parameters do not affect the model output significantly. There have been many studies focused on model sensitivity to input parameters. For an input parameter to vary there must be uncertainty about the value. This research proposes a method of including parameter uncertainty with model sensitivity to quantify the importance of a parameter, where the term importance is a combination of parameter uncertainty and sensitivity. Using the method developed in this thesis, an importance assessment was conducted on an analytical model for vadose zone transport. It was found that for sites posing high risk, with large spill volumes and shallow water table depths, the input parameters of water table depth and spill volume were the most important. The input parameters of precipitation and contaminant biodegradation half-life showed high importance in lower risk situations; when the water table was deep. A comparison of sensitivity analysis to importance showed differences in their results. The sensitivity analysis identified those parameters that the model was sensitive to, while the importance assessment identified the parameters that were sensitive and whose range of uncertainty was large enough to affect model output values. This information could be used for resource allocation decisions when acquiring additional site specific information.
3

GREY-MODEL BASED ICE PREDICTION SENSOR SYSTEM ON WIND TURBINE SYSTEM

Feng, Chao 30 January 2012 (has links)
No description available.
4

Multi-Parameter Fluorescent Analysis and Quantitative Magnetophoresis Study as Two Different Technologies to Detect and Characterize Cells and Its Various Applications as Biomarkers

Park, Kyoung-Joo Jenny January 2017 (has links)
No description available.
5

Identificação por decomposição de sinais de consumo de energia elétrica

Dantas, Pierre Vilar 29 June 2016 (has links)
Submitted by Divisão de Documentação/BC Biblioteca Central (ddbc@ufam.edu.br) on 2017-02-21T12:37:16Z No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Dissertação - Pierre V. Dantas.pdf: 2603862 bytes, checksum: 2b203ea2bbd3a5c21421914f4f10b9fb (MD5) / Approved for entry into archive by Divisão de Documentação/BC Biblioteca Central (ddbc@ufam.edu.br) on 2017-02-21T12:37:33Z (GMT) No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Dissertação - Pierre V. Dantas.pdf: 2603862 bytes, checksum: 2b203ea2bbd3a5c21421914f4f10b9fb (MD5) / Approved for entry into archive by Divisão de Documentação/BC Biblioteca Central (ddbc@ufam.edu.br) on 2017-02-21T12:37:57Z (GMT) No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Dissertação - Pierre V. Dantas.pdf: 2603862 bytes, checksum: 2b203ea2bbd3a5c21421914f4f10b9fb (MD5) / Made available in DSpace on 2017-02-21T12:37:57Z (GMT). No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Dissertação - Pierre V. Dantas.pdf: 2603862 bytes, checksum: 2b203ea2bbd3a5c21421914f4f10b9fb (MD5) Previous issue date: 2016-06-29 / The identification by decomposition of electricity consumption signals tech- nique, we estimate the consumption of devices that form a power consumption signal. This technique, that can be called disaggregation or nonintrusive load monitoring, is important because it makes possible obtain information about the individual energy consumption of devices, allowing other approaches like power management, use in smart grids and Internet of Things (IoT). Energy disaggregation problem can be approached through dictionaries techniques, which summarize the most significant characteristics of the signals involved to signal disaggregation. In our proposal, we highlight two contributions. In the first, we modify the steady-state identi- fication (SSI) algorithm to deal with signals with variable dimensions and, then, we conducted a parameter analysis that changes the dictionaries and consequently produces different performances of disaggregation. Second, we propose a disaggrega- tion methodology using principal component analysis (PCA). The experiments were made using REDD database [1] and they demonstrate that the proposal produces results with higher accuracy when compared with other techniques. / Na técnica de identificação por decomposição de sinais de consumo de energia elétrica, inferimos o consumo dos dispositivos que compõem um sinal de consumo de energia elétrica. Essa técnica, também denominada de desagregação ou moni- toramento não intrusivo, é relevante porque viabiliza obtermos informação sobre o consumo energético individualizado de dispositivos, o que permite outras abordagens sobre o gerenciamento energético, viabiliza uso em redes inteligentes (smart grids) e internet das coisas (IoT). O problema de desagregação de energia pode ser tra- tado através de técnicas por dicionários onde extraímos representatividades de um conjunto de dados de consumo de energia elétrica e realizamos a desagregação. Em nossa proposta, podemos destacar duas contribuições. Na primeira, modificamos o algoritmo steady-state identification (SSI) para contemplar sinais com dimensões variáveis e, a seguir, realizamos uma análise de parâmetros que influenciam na for- mação dos dicionários e, por consequência, produzem diferentes desempenhos de desagregação. Na segunda, propomos uma metodologia de desagregação por análise de componentes principais. Os experimentos realizados, utilizando a base de dados REDD [1], demonstram que a proposta produz resultados de desagregação de maior acurácia, quando comparado com outras técnicas.
6

Surface and Subsurface Flow Connection and Dominating Runoff Mechanism in Hillslope of Tarfala, Northern Sweden. / Dominerande avrinningsmekanism och koppling melllan yt- och markflöde i en sluttning i Tarfaladalen, norra Sverige.

Maharjan, Namika January 2023 (has links)
The Sub artic regions are becoming increasingly important due to the effects of climate change. In northern Sweden, thawing of permafrost has led to significant increases in annual minimum flows in several catchments. This has led to studies of groundwater flow, responses to precipitation and runoff, and subsurface connectivity of springs on slopes. However, there remains a limited understanding of the interplay between surface flow and subsurface flow in the hillslopes of subarctic region. There is a need to better understand the flow pathways and connectivity of groundwater flows within the slopes. This study aims to analyze the interactions between surface flow and subsurface flow on an Sub artic mountainside. Utilizing tracer experiments and a hydrological model, the complex dynamics governing water movement within this intricate system have been studied.  Tracer experiments affirmed the hydraulic connection between hillslope and spring. The spring's response to tracer injection hinted at dominant preferential flow paths within the regolith layer's base. Nonetheless, only 40% mass recovery raised queries about factors affecting the flow in the hillslope. Thus, in this project, a model was developed using Advanced Terrestrial Simulator (ATS) to examine the dominant flow processes and evaluate the influence of various hydrogeology parameters and fluid flow properties on tracer movement. The results highlight the dominance of subsurface flows occurring close to the surface. The parameter sensitivity analysis conducted in the study showed that roughness coefficient and permeability significantly influenced specific pathways and directions that water, and tracers took as they moved through the hillslope's subsurface layers and regolith.  However, the model has limitations, such as neglecting the lateral variations of the subsurface material, seasonal freeze-thaw processes and the simplified representation of the slope and catchment. The results of this study show the need for utilizing more field-based methodologies and further refinement of the modeling approach to improve our understanding of hydrologic processes in high latitude areas.
7

Measurement and distribution of nitrogen dioxide in urban environments

Kirby, Carolyn January 1999 (has links)
No description available.
8

Analysis of Vehicle Dynamics and Control of Occupant Biodynamics using a Novel Multi-Occupant Vehicle Model

Joshi, Divyanshu January 2016 (has links)
Due to the detrimental effects of ride vibrations on occupants and increasing safety concerns, improvement in vehicle dynamic characteristics has become a key focus of researchers. Typically, ride and handling problems have been dealt with independently. There is a dearth of vehicle models capable of capturing occupant biodynamics and its implication on vehicle ride and handling. Also in general, the objective of conventional control systems has been to attenuate vertical dynamic response of the sprung mass of a vehicle. Feedback control based algorithms are predominantly used in active/semi-active suspensions that ignore the biodynamics of occupants. In the current work, a new 50 degree-of-freedom (DOF) combined nonlinear multi-occupant vehicle model is developed using the lumped parameter modelling (LPM) approach. The current model provides a platform for performing a combined study of ride, handling and occupant biodynamics. The model is capable of simulating the combined effect of sitting occupancies, road inputs and driving maneuvers on biodynamic responses. It is analyzed using MATLAB/SIMULINK functionalities and validated by independently correlating the computed responses with existing experimental results. A study is performed on ride behavior of a vehicle-occupant system under two different transient road inputs. In addition, the effect of road roughness on vehicle ride is also studied. Random road profiles are generated from road roughness spectrum given in the ISO 8608:1995 manual. Insights are developed into the ride dynamics of a vehicle traversing over roads of classes A, B, C and D at given test velocities. The effect of sitting occupancies and vehicle velocities on lateral dynamics is also studied. Results underscore the need for considering sitting occupancies while analyzing vehicle dynamics and also highlight the potential of the current model. Furthermore, a Moore-Penrose Pseudoinverse based feed-forward controller is developed and implemented in an independently acting semi-active seat suspension system. Feasibility of feed-forward control in primary suspensions is also investigated. Finally, issues of stability, performance and limitation of the controller are discussed.
9

Analysis of Performance Parameters for Service Assurance in Radio Access Networks / Analys av prestandaparametrar för service assurance I radionätverk

Raymat, Daryell, Chaker, Mohammed January 2023 (has links)
During the thesis project, an evaluation tool was developed for Telenor. This tool identifies the most reliable cell within a site based on its standard deviation and systematically ranks the performance of each cell using key performance indicators (KPIs). The tool also calculates the mean and the median to allow the user to get an overview over the network performance. The analysis underscored the importance of robust network reliability, especially when considering the deployment of home care technologies in remote areas. The tool is designed to analyse extracted data, providing Telenor with a view of network performance and ensuring top-tier service quality in even the most remote and challenging terrains. / Under examensarbetet lades fokus på skapandet av ett utvärderingsverktyg för Telenor. Detta verktyg bestämmer den mest tillförlitliga cellen inom en basstation baserat på dess standardavvikelse för den analyserade KPI och klassificerar varje cells prestanda. Utöver det räknas medelvärdet och medianen ut för att användaren ska få en bättre översikt över nätverksprestandan. Utbyggnaden av hemvårdsteknologier i avlägsna områden tas särskilt i beaktande. Verktyget är designat för analys av data och ger en översikt över nätverkets prestanda, vilket kan bidra till att säkerställa optimal servicekvalitet.
10

Modellering av grävpålar i Plaxis 2D : En parameterstudie applicerad på nya Vårbybron, Stockholm / Modelling of bored piles in Plaxis 2D : A parametric analysis applied at the new bridge Vårbybron, Stockholm

Johansson, Josefin, Wennberg, Matilda January 2021 (has links)
I samband med Förbifart Stockholm och Tvärförbindelse Södertörn förväntas en flaskhals skapas vid Vårbybron i södra Stockholm. För att förhindra överbelastning planeras en nybyggnation där pålgrundläggning med grävpålar föreslås. Markförhållanden är ovanliga i Stockholm, med över 100 meter ned till berg. Komplexa omständigheter i området gör det nödvändigt att analysera markrörelser som verkar på grundläggningen. Syftet med studien är att undersöka horisontella- och vertikala sättningar vid ett brolandfäste. Syftet är vidare att analysera vilken typ av numerisk konstitutiv modell som är lämplig med hänsyn till studiens specifika fall och område; Mohr-Coulomb (MC), Hardening Soil (HS) och Hardening Soil med small-strain stiffness (HSS). Slutligen ska jordparametrarnas väsentlighet avgöras i en parameterstudie. Sonderingsdata tillämpas i studien för att skapa en jordlagermodell i AutoCAD Civil 3D 2019 Metric och vidare simulering av sättningar i Plaxis 2D. Vid modellering av sättningar i förekommande geologi rekommenderas att en avancerad modell används, med fördel HSS. Däremot kräver mer avancerade modeller noggranna indata för tillförlitligt resultat och ytterligare tester för styvhetsparametrar bör utföras. I detta projekt kan dyrare tester tänkas sänka slutgiltig budget, eftersom underskattning av moduler i djupa och fast lagrade jordar baserade på konservativt valda moduler ger upphov till en dyrare konstruktion. / In conjunction with the opening of the Stockholm Bypass and Tvärförbindelse Södertörn, a bottleneck is expected at the bridge Vårbybron in southern Stockholm. To prevent traffic congestion, a new construction is planned where pile foundation consisting of bored piles is proposed. The ground conditions are unusual and not typical for Stockholm involving over 100 meters distance to rock. Complex circumstances in the area makes it complicated as well as necessary to analyze ground movements. The aim of the study is to investigate horizontal- and vertical settlements at a bridge abutment. The aim is further to analyze which type of numerical constitutive model that is appropriate with respect to the specific case and area; Mohr-Coulomb (MC), Hardening Soil (HS) and Hardening Soil with small-strain stiffness (HSS). Finally, the significance of the soil parameters is to be determined in a parameter analysis. Results from soundings are used to create a geological model in AutoCAD Civil 3D 2019 Metric. Furthermore, simulation of settlements in Plaxis 2D is performed. It is recommended to apply advanced models for this type of geology, advantageously HSS. However, more advanced models require accurate input data to obtain reliable results, and additional tests for stiffness parameters must be performed for accuracy in the results. In this project, more expensive tests can be thought of as lowering the final budget, as underestimation of modules in deep and stiff soils based on conservatively selected modules leads to an unnecessarily expensive construction.

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