• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 2
  • 1
  • 1
  • 1
  • 1
  • Tagged with
  • 7
  • 3
  • 3
  • 3
  • 2
  • 2
  • 2
  • 2
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 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

Effects of Automoblie Tailpipe Emissions in the Hsuehshan Tunnel on the Air Quality of Neighboring Areas Using ADMS Model

Wang, Chen-wen 30 June 2009 (has links)
The Hsuehshan tunnel, whose length is about 12.9 kilometers, is the longest tunnel in Taiwan and Southeast Asia. Since the tunnel is used, it reduces the traveling time from Taipei to Ilan and brings the convenience of transportation; but the vehicles and pollution sources are added. Furthermore, the concentrations of pollutants are increased by accumulation in the long tunnel. This study estimates the effects of automobile tailpipe emissions in the Hsuehshan tunnel on the air quality of neighboring areas by using Atmospheric Dispersion Modelling System for Roads (ADMS-Roads). This work simulates carbon monoxide (CO), nitrous oxides (NOx) and sulfur dioxide (SO2) at two sites (Pin-Ling and Tou-Cheng management centers) in northern Taiwan in winter of 2008. The average concentrations of CO, NOx and SO2 at Pin-Ling (Tou-Cheng) management centers respectively are 0.49 (0.55) ppm, 10.60 (14.83) ppb and 4.80 (7.47) ppb on non-holiday and 0.66 (0.64) ppm, 16.88 (15.12) ppb and 4.70 (4.20) ppb on holiday. It shows that the concentrations of pollutants on holiday are higher than on non-holiday by increasing vehicles. Simulated results show that effects of traffic exhaust in the tunnel on the air quality of neighboring areas are less. Estimations using the ADMS-Roads suggest that the emissions are not the predominant contributors at two sites. The effect is the highest with northern (northeastern) winds at the southern (northern) area of the Hsuehshan tunnel. Comparisons between simulations and measurements at both sites are satisfactory. Simulated values are generally in agreement with measured values, with a correlation coefficient of R = 0.37 ¡V 0.81, the index of agreement (IOA) = 0.58 ¡V 0.77, and the normalized mean square error (NMSE) = 0.03 ¡V 0.25. The ADMS-Roads will be applied to assess the environmental impact while the tunnel will be allowed more types of vehicles to drive in the future.
2

Parametrické CAD systémy a databáze součástí / Parametric CAD systems and parts database

Szoltys, Kryštof January 2009 (has links)
Autodesk Inventor is a full 3D CAD system. This system includes tools for working environment tool, component design tool including information data management and technical support. The target of the first part is to describe the most important new features brought by Autodesk Inventoru 2009 version. In of next chapters the work describes creation common iPart, which is basically different variants set (proportions, material …) of one entity, and preparation before correct publication to the content center, which is a virtual database of all iPart. Also there is presented how to create the content center, how to work with it and adjust data. The aim of work is then the creation database a stator and a rotor packet for the firm ATAS electromotor Náchod Inc. In the thesis there is described creation of the lamination as an iPart and their publication to the new content center.
3

Napredni distributivni menadžment sistem zasnovan na Cloud infrastrukturi / Cloud Infrastructure-based Advanced Distribution Management System

Popović Nemanja 24 May 2018 (has links)
<p>U ovoj doktorskoj disertaciji ispitana je mogućnost prebacivanja Naprednog Distributivnog Menadžment Sistema (NDMS) zasnovanog na zajedničkoj operaciono tehnološkoj platformi na virtualno Cloud infrastrukturno okruženje. Prvo je odabrano tradicionalno NDMS rešenje zasnovano na fizičkoj računarskoj arhitekturi i identifikovani su funkcionalni blokovi. Zatim su profilirane njihove performanse prema četiri ključna resursa: procesor, operativna memorija, računarska mreža i stalna memorija. Dalje predloženo je virtualno rešenje zasnovano na Cloud infrastrukturi koje je verifikovano na dve zamišljene elektrodistributivne mreže realnih veličina (maloj i velikoj) i u dva testna scenarija (stabilnog stanja i visoke aktivnosti). Na kraju predstavljeni su rezultati testiranja koji pokazaju da se NDMS može prebaciti u virtualno Cloud okruženje bez negativnog uticaja na funkcionalne i nefunkcionalne zahteve NDMS rešenja.</p> / <p>This dissertation inspects the possibility of transferring the Advanced Distribution Management System (ADMS) based on a common operating technology platform to the virtual Cloud Infrastructure Environment. First, a traditional ADMS solution based on physical computing architecture was chosen and functional blocks were identified. Furthermore, their performances were profiled to four key resources: processor, operating memory, computer network, and storage. Then, virtual cloud-based solution was proposed based on Cloud infrastructure which is verified on two imaginary power distribution networks of real size (small and large) and in two test scenarios (steady state and high activity). Finally, the test results show that ADMS can be transferred to a virtual Cloud environment without adversely affecting the functional and non-functional requirements of the ADMS solution.</p>
4

The impact of Beirut Rafic Hariri International Airport’s activities on the air quality of Beirut & its suburbs : measurements and modelling of VOCs and NO2 / Impact de l'aéroport Rafic Hariri sur la qualité de l'air de Beyrouth : mesure de modélisation des COVs et NO2

Mokalled, Tharwat 23 September 2016 (has links)
Cette thèse étudie l’impact de l’Aéroport international de Beyrouth sur la qualité de l’air de Beyrouth et ses banlieues par mesures et modélisation des COVs et NO2. Il s’agit de la première étude qui identifie les signatures des émissions (COVs) issues des avions sous opération réelle. Grâce aux signatures détectées lors de 4 campagnes réalisées, nous constatons que l’aéroport a un impact sur la qualité de l’air de son voisinage, la zone côtière (trajectoire d’atterrissage), et les zones montagneuses. Ces résultats sont confirmés via le modèle ADMS-Airport, utilisé pour la première fois au Moyen-Orient et validé pour les conditions libanaises (r = 0.86). Par ailleurs, les concentrations de 47 COVs ont été mesurées pour la première fois à l'intérieur d’un bâtiment de l'aéroport. Les teneurs en COVs qui sont corrélées au nombre d’avions sont en dessous des valeurs seuils sauf pour l'acroléine alors que la celle de NO2 peut constituer un danger pour la santé. / This work mainly investigated the impact of Beirut Airport on the air quality of Beirut and its suburbs via both measurements and modeling of VOCs and NO2. This is the first study to determine VOC signatures of exhaust emissions from aircraft under real operation. Using these signatures, the impact of the airport activities was tracked in 4 transect campaigns, where it was found that the airport impacts air quality not only in its vicinity, but also on the seashore (landing jet trajectory) and in mountainous areas. These results were confirmed via modeling with ADMS-Airport, implemented for the first time in the Middle East, after being validated in the Lebanese conditions (r = 0.86). As a secondary goal, and for the first time, 47 VOCs were assessed inside an airport building. Measured VOC levels did not present any risks except for acrolein. In the arrivals hall, NO2 levels indicated a health hazard; while a direct relationship was found between aircraft number and VOC concentrations.
5

Platforma za transformaciju softverskih rešenja pametnih elektroenergetskih mreža na cloud bazirani višeorganizacijski SaaS / A Platform for Smart Grid Software Solution Migration to Cloud Based SaaS

Dalčeković Nikola 13 September 2019 (has links)
<p>Sve češćom upotrebom cloud okruženja dolazi do potrebe da se postojeća softverska rešenja migriraju. Metodologija za migraciju na cloud postoji više, gde se u finalnim fazama planiraju modifikacije nad arhitekturom softvera tako da se iskoriste prednosti cloud sistema. Za ekonomsku efikasnost usled uštede resursa je neophodna višeorganizacijska osobina. Svrha ovog istraživanja je da pojasni višeorganizacijsko svojstvo i da predloži rešenje za migraciju postojećih softvera na višeorganizacijski SaaS ali sa što manje neophodnih modifikacija ciljnog softvera. S toga je predloženo rešenje platforma koja omogućuje lakšu migraciju. Nakon faze istraživanja i sagledavanja domena pametnih elektroenergetskih mreža, kreiran je prototip predloženog rešenja kao i niz eksperimenata u skladu sa definisanim naučnim pitanjima. Eksperimenti su izvršeni u privatnom cloud okruženju. Hipoteze su adresirane kroz viziju primene rešenja na NDMS (Napredni distributivni menadžment sistem) u slučaju šest organizacija, a doneti su sledeći zaključci: višeorganizacijskim modelom se ostvaruju uštede u resursima od 32%, za tri reda veličine veća visoka dostupnost, ali uz usporenja do 20 milisekundi po svakom servisnom zahtevu. Takođe, aplikativni model učesnika modernih PaaS usluga nije primeren gde je sinhronizam zahtevan, niti u slučajevima gde se očekuju odgovori nad skupom učesnika u realnom vremenu. Istraživanje ukazuje na mogućnost primene višeorganizacijskog modela čak i u slučaju kompleksnih rešenja kakva se sreću u domenu pametnih elektroenergetskih mreža, a akademskom validacijom potvrđuju način implementacije važnog finalnog koraka u procesu migracije softvera na cloud bazirani SaaS.</p> / <p>Progressive cloud adoption requires migration of existing software solutions. Today, many cloud adoption methodologies exist. Usually, the final phase in cloud adoption include software architecture modifications to make the most of the benefits of cloud computing, like multi-tenancy which enables economic efficiency. The aim of this research is to explain the multi-tenancy and to provide a solution for migration of existing software to multi-tenant SaaS while modifying the target software as little as possible. Therefore, the research proposes a platform that enables easier cloud adoption. After the research phase focused on a smart grid domain, the prototype was created with experiments targeting formulated research questions. The experiments were conducted in a private cloud environment. Research hypotheses were analyzed using hypothetical multi-tenant ADMS (Advanced Distribution Management System) in case of six tenants, with the following conclusions: multi-tenancy saves 32% of resources, it provides three orders of magnitude higher availability, but affects performances by introducing a delay of up to 20 milliseconds per service request. Also, reliable actors programing model used in modern PaaS services is not suitable in use cases with needs for synchronous behavior, nor in in use cases where querying a set of actors is needed in real time. The research demonstrates feasibility of applying multi-tenancy even in cases of complex software solutions like the ones in the smart grid domain. The proposed solution is academically validated and it can be used as a final important step in migration of existing software to cloud based multi-tenant SaaS.</p>
6

Optimal nätdesign : Utvärdering och jämförelse av nätstrukturer i Stockholms mellanspänningsnät / Optimal grid design : Evaluation and comparison of network structures in Stockholm's MV-grid

Wennberg, Simon January 2017 (has links)
In today’s society the electric grid has become one of the most important infrastructures and industries as well as other infrastructures, and individuals rely on its functionality. The unavailability of electricity caused by outages is increasingly rare but when it occurs it can have serious consequences. An electric grid’s reliability is now a requirement, not only from customers but also from the regulatory authority.The electric grid in Stockholm is owned and operated by Ellevio AB. Over the past decade the reliability, measured in SAIDI (System Average Interruption Duration Index), in the area has deterioated, mainly due to failures of the medium voltage grid (11- kV, MV). The network structure on the MV- grid consists primarily of two parallel medium voltage cables each of which acts redundantly to its pair cable. The technique, called dual cable structure, works most optimally with substations with automatic switching, which automaticly switch over to the redundant cable when failure occurs. However substations without this automatic switching are widely used resulting in a longer interruption time. Another network structure is the ring or loop structure, which still has redundancy, but when failure occurs a load- break switch must close so that the grid can be fed from another direction. The substation in the loop structure can also be remotely controlled, making the load-break swith operable from the control center, resulting in a shorter interruption time.This thesis evaluates and compares different network structures consisting of dual cable with automatic switching and loop structure with remotely controlled substations, based on economy and reliability, on Stora Essingen. The two structures have been designed in the network information system program Trimble NIS and divided into two different environments; one developed and one undeveloped environment. The results show that the technical solutions in network structures of MV- grid do not necessarily mean major differences in economy nor reliability, rather the choice between few but long interruptions and many but short interruptions is central. Results show however that a combination of the dual cable structure with remotely controlled substations in the undeveloped environment is economically motivated while the reliability can be maintained at the same tame.
7

Assessing urban air quality through measurements and modelling and its implications for human exposure assessment

Wu, Hao January 2017 (has links)
Outdoor air pollution is a major contributor to adverse health effects of citizens, in particular those living in urban environments. Air quality monitoring networks are set up to measure air quality in different environments in compliance with national and European legislation. Generally, only a few fixed monitoring sites are located within a city and thus cannot represent air pollutant concentrations in urban areas accurately enough to allow for a detailed human exposure assessment. Other approaches to derive detailed urban air pollutant concentration estimates exist, such as dispersion models and land-use regression (LUR) models. Low-cost portable air quality monitors are also emerging, which have the potential to add value to existing monitoring networks by providing measurements at greater spatial resolution and also to provide individual-level exposure assessment. The aim of this thesis is to demonstrate how measurements and modelling in combination allow detailed investigations of the variability of air pollutants in space and time in urban area, and in turn improve on the current exposure assessment methods. Three types of low-cost portable monitors measuring NO2, O3 (Aeroqual monitors) and PM2.5 (microPEM monitor) were evaluated against their respective reference instruments. The Aeroqual O3 monitor showed very good correlation (r2 > 0.9) with the respective reference instruments, but biases in the slope and intercept coefficients indicated that calibration of Aeroqual O3 monitor was needed. The Aeroqual NO2 monitor was subject to cross-sensitivity from O3, which, as demonstrated, can be effectively corrected by making O3 and NO2 measurements in tandem. Correlation between the microPEM monitor and its reference instrument was poor (r2 < 0.1) when PM2.5 concentrations were low (< 10 μg m-3), but significantly improved (r2 > 0.69) during periods with elevated PM2.5 concentrations. Relative humidity was not found to affect the raw results of PM2.5 measurements in a consistent manner. All three types of monitors cannot be used as equivalent or indicative methods instead of reference methods in studies that require quantification of absolute pollutant concentrations. However, the generally good correlations with reference instruments reassure their application in studies of relative trends of air pollution. Concentrations of PM2.5, ultrafine particles (UFP) and black carbon (BC) were quantified using portable monitors through a combination of mobile and static measurements in the city of Edinburgh, UK. The spatial variability of UFP and BC was large, of similar magnitude and about 3 times higher than the spatial variability of PM2.5. Elevated concentrations of UFP and BC were observed along streets with high traffic volumes whereas PM2.5 showed less variation between streets and a footpath without road traffic. Both BC and UFP significantly correlated with traffic counts, while no significant correlation between PM2.5 and traffic counts was observed. The relationships between UFP, NO2 and inorganic components of PM2.5 were further investigated through long-term measurements at roadside, urban background and rural sites. UFP moderately correlated with NOx (NO2 + NO) and showed varying relationships with NOx depending on the particle size distribution. Principal component analysis and air-mass back trajectory analysis revealed that PM2.5 concentrations were dominated by long-range transport of secondary inorganic aerosols, whereas UFP were mainly related to varying local emissions and meteorological conditions. These findings imply the need for different policies for managing human exposure to these different particle components: control of much BC and UFP appears to be manageable at local scale by restricting traffic emissions; however, abatement of PM2.5 requires a more strategic approach, in cooperation with other regions and countries on emissions control to curb long-range transport of PM2.5 precursors. A dispersion model (ADMS-Urban) was used to simulate high resolution NO2 and O3 concentrations in Edinburgh. The effects of different emission and meteorological input datasets on the resulting modelled NO2 concentrations were investigated. The modelled NO2 and O3 concentrations using the optimal model setup were validated against reference instrument and diffusion tube measurements. Temporal variability of NO2 was predicted well at locations that were not heavily influenced by local effects, such as road junctions and bus stops. Temporal variability of O3 was predicted better than for NO2. Long-term spatial variability of NO2 was found to correlate well with diffusion tube measurements, while modelled spatial variability of O3 in ADMS-Urban compared poorly with diffusion tube measurements. However, it was found that the O3 diffusion tube measurements may be subject to some unidentified biases affecting their accuracy. Land-use regression (LUR) models are widely used to estimate exposure to air pollution in urban areas. An appropriately sized and designed monitoring network is an important component for the development of a robust LUR model. Concentrations of NO2 were simulated by ADMS-Urban at ‘virtual’ monitoring sites in 54 different network designs of varying numbers and types of site, using a 25 km2 area including much of the Edinburgh city area. Separate LUR models were developed for each network. These LUR models were then used to estimate ambient NO2 concentrations at all residential addresses, which were evaluated against the ADMS-Urban modelled concentration at these addresses. The improvement in predictive capability of the LUR models was insignificant above ~30 monitoring sites, although more sites tended to yield more precise LUR models. Monitoring networks containing sites located within highly populated areas better estimated NO2 concentrations across all residential locations. LUR models constructed from networks containing more roadside sites better characterised the high end of residential NO2 concentrations but had increased errors when considering the whole range of concentrations. No particular composition of monitoring network resulted in good estimation simultaneously across all residential NO2 concentration and of the highest NO2 levels implying a lack of spatial contrast in LUR-modelled pollution surface compared with the dispersion model. Finally, the results from the measurement and modelling studies presented in thesis are synthesised in the context of current exposure assessment studies. Low-cost air-quality monitors currently do not possess and are unlikely in the near future to provide the robustness and accuracy to replace the existing routine monitoring network. Development of the low-cost air-quality should be aiming at upgrading them as the indicative method as defined in the data quality objective in the EU directive. The monitoring sites used to build LUR models should capture well the population distribution in the study area as opposed to capturing the greatest pollution contrast. The traditional methods of evaluating LUR models are also ineffective in characterising the models’ capability at estimating pollutant concentration at residential address. Given that the dispersion models are also subject to the availability and uncertainties in the input data, future air quality model development should endeavour to incorporate both dispersion and land-use regression models, where the uncertainty in the input data can be reduced by using LUR models built on actual measurements, and the limitation in the statistical modelling can be replaced by adopting the deterministic approach used in the dispersion model.

Page generated in 0.0233 seconds