Der »Jahresbericht 2009 zur Luftqualität in Sachsen« beinhaltet und bewertet die Messergebnisse zur Luftqualität im Freistaat Sachsen. Das 31 Messstellen umfassende stationäre Luftmessnetz misst die Konzentration der Luftschadstoffe Schwefeldioxid, Stickstoffdioxid, Feinstaub-Partikel, Blei, Benzol und Ozon. Bei den meisten Schadstoffen lag die Belastung auf dem Niveau des Vorjahres. Sie war niedriger als in den Jahren zuvor. Eine Ausnahme bildete der 24-Stunden-Grenzwert der Partikel-Konzentration (PM10). Hier gab es einen Anstieg gegenüber dem Vorjahr. An Verkehrsmessstellen in Leipzig, Dresden und Görlitz wurde dieser Grenzwert mehr als zulässig überschritten. Ursachen waren insbesondere die kalte Witterung im Januar und die extreme Trockenheit im April. Beim Jahreswert der NO2-Konzentration wurde wie in den Vorjahren in den Städten Dresden, Chemnitz und Leipzig der ab 2010 geltende Grenzwert nach EU-Richtlinie 2008/50/EG überschritten. Messstellen in ländlichen Gebieten zeigten bei Ozon weiterhin Überschreitungen der Zielwerte zum Schutz der menschlichen Gesundheit und der Vegetation.

The thesis focuses on the management and functionality of the Network Operations Center, whose function is to maintain optimal network operations on various platforms, media and communication channels. The department is in a company that develops AAA game titles. The first part defines the theoretical basis. The next section introduces the company together with the analysis of the functioning of the department and communication. The last part is devoted to the design of the organizational structure, which includes the process of creating a new job. The process involves the division of activities, the recruitment process and the economic appreciation itself.

This dissertation is put together from a set of three journal papers. The first paper describes how satellite imagery and spacecraft autonomy are used to advance the field of near real-time detection, monitoring, and rapid response to flooding. The second paper describes the ground instrumentation of an artificial water recharge basin field site close to Tucson with a network of inter-connected sensors to study the transient process of repeated flooding in real-time, and the third paper describes an effort to link together multiple ground-based and space-based remote sensing assets to an integrated and coordinated monitoring system for floods. Collectively, the three papers describe new breakthroughs in the field of flood detection and monitoring through the use of satellite onboard automation and Sensorweb networks.

This thesis analyzes the difficulties of managing the security of an enterprise network. The problem that this thesis study deals with is the central management of a large number and variety of services that provide organization-wide network and information security. This study addresses two problem areas: how to better manage the security of a network, and how to explain the security issues to upper management better. The study proposes a Security Management System (SMS) to be used for network security management, monitoring and reporting purposes. The system is a custom made, central management solution, which combines the critical performance indicators of the security devices and presents the results via web pages.

Carbon Dioxide (CO₂) Enhanced Oil Recovery (EOR) is becoming an important bridge to commercialize geologic sequestration (GS) in order to help reduce anthropogenic CO₂ emissions. Current U.S. environmental regulations require operators to monitor operational and groundwater aquifer changes within permitted bounds, depending on the injection activity type. We view one goal of monitoring as maximizing the chances of detecting adverse fluid migration signals into overlying aquifers. To maximize these chances, it is important to: (1) understand the limitations of monitoring pressure versus geochemistry in deep aquifers (i.e., >450 m) using analytical and numerical models, (2) conduct sensitivity analyses of specific model parameters to support monitoring design conclusions, and (3) compare the breakthrough time (in years) for pressure and geochemistry signals. Pressure response was assessed using an analytical model, derived from Darcy's law, which solves for diffusivity in radial coordinates and the fluid migration rate. Aqueous geochemistry response was assessed using the numerical, single-phase, reactive solute transport program PHAST that solves the advection-reaction-dispersion equation for 2-D transport. The conceptual modeling domain for both approaches included a fault that allows vertical fluid migration and one monitoring well, completed through a series of alternating confining units and distinct (brine) aquifers overlying a depleted oil reservoir, as observed in the Texas Gulf Coast, USA. Physical and operational data, including lithology, formation hydraulic parameters, and water chemistry obtained from field samples were used as input data. Uncertainty evaluation was conducted with a Monte Carlo approach by sampling the fault width (normal distribution) via Latin Hypercube and the hydraulic conductivity of each formation from a beta distribution of field data. Each model ran for 100 realizations over a 100 year modeling period. Monitoring well location was varied spatially and vertically with respect to the fault to assess arrival times of pressure signals and changes in geochemical parameters. Results indicate that the pressure-based, subsurface monitoring system provided higher probabilities of fluid migration detection in all candidate monitoring formations, especially those closest (i.e., 1300 m depth) to the possible fluid migration source. For aqueous geochemistry monitoring, formations with higher permeabilities (i.e., greater than 4 x 10⁻¹³ m²) provided better spatial distributions of chemical changes, but these changes never preceded pressure signal breakthrough, and in some cases were delayed by decades when compared to pressure. Differences in signal breakthrough indicate that pressure monitoring is a better choice for early migration signal detection. However, both pressure and geochemical parameters should be considered as part of an integrated monitoring program on a site-specific basis, depending on regulatory requirements for longer term (i.e., >50 years) monitoring. By assessing the probability of fluid migration detection using these monitoring techniques at this field site, it may be possible to extrapolate the results (or observations) to other CCUS fields with different geological environments. / text

Der »Jahresbericht 2009 zur Luftqualität in Sachsen« beinhaltet und bewertet die Messergebnisse zur Luftqualität im Freistaat Sachsen. Das 31 Messstellen umfassende stationäre Luftmessnetz misst die Konzentration der Luftschadstoffe Schwefeldioxid, Stickstoffdioxid, Feinstaub-Partikel, Blei, Benzol und Ozon. Bei den meisten Schadstoffen lag die Belastung auf dem Niveau des Vorjahres. Sie war niedriger als in den Jahren zuvor. Eine Ausnahme bildete der 24-Stunden-Grenzwert der Partikel-Konzentration (PM10). Hier gab es einen Anstieg gegenüber dem Vorjahr. An Verkehrsmessstellen in Leipzig, Dresden und Görlitz wurde dieser Grenzwert mehr als zulässig überschritten. Ursachen waren insbesondere die kalte Witterung im Januar und die extreme Trockenheit im April. Beim Jahreswert der NO2-Konzentration wurde wie in den Vorjahren in den Städten Dresden, Chemnitz und Leipzig der ab 2010 geltende Grenzwert nach EU-Richtlinie 2008/50/EG überschritten. Messstellen in ländlichen Gebieten zeigten bei Ozon weiterhin Überschreitungen der Zielwerte zum Schutz der menschlichen Gesundheit und der Vegetation.

Wide-area measurement systems (WAMS) enable the monitoring of overall bulk power systems and provide critical information for understanding and responding to power system disturbances and cascading failures. The North American Frequency Monitoring Network (FNET) takes GPS-synchronized wide-area measurements in a low-cost, easily deployable manner at the 120 V distribution level, which presents more opportunities to study power system dynamics. This work explores the topics of power system disturbance analysis and detection by utilizing the wide-area measurements obtained in the distribution networks. In this work, statistical analysis is conducted based on the major disturbances in the North American Interconnections detected by the FNET situation awareness system between 2006 and 2008. Typical frequency patterns of the generation and load loss events are analyzed for the three North American power Interconnections: the Eastern Interconnection (EI), the Western Electricity Coordinating Council (WECC), and the Electric Reliability Council of Texas (ERCOT). The linear relationship between frequency deviation and frequency change rate during generation/loss mismatch events is verified by the measurements in the three Interconnections. The relationship between the generation/load mismatch and system frequency is also examined based on confirmed generation loss events in the EI system. And a power mismatch estimator is developed to improve the current disturbance detection program. Various types of power system disturbances are examined based on frequency, voltage and phase angle to obtain the event signatures in the measurements. To better understand the propagation of disturbances in the power system, an automated visualization tool is developed that can generate frequency and angle replays of disturbances, as well as image snapshots. This visualization tool correlates the wide-area measurements with geographical information by displaying the measurements over a geographical map. This work makes an attempt to investigate the visualization of the angle profile in the wide-area power system to improve situation awareness. This work explores the viability of relying primarily on distribution-level measurements to detect and identify line outages, a topic not yet addressed in previous works. Line outage sensitivity at different voltage levels in the Tennessee Valley Authority (TVA) system is examined to analyze the visibility of disturbances from the point of view of wide-area measurements. The sensor placement strategy is proposed for better observability of the line trip disturbances. The characteristics of line outages are studied extensively with simulations and real measurements. Line trip detection algorithms are proposed that employs the information in frequency and phase angle measurements. In spite of the limited FDR coverage and confirmed training cases, an identification algorithm is developed which uses the information in the real measurements as well as the simulation cases to determine the tripped line. / Ph. D.

abstract: Air pollution is a serious problem in most urban areas around the world, which has a number of negative ecological and human health impacts. As a result, it's vitally important to detect and characterize air pollutants to protect the health of the urban environment and our citizens. An important early step in this process is ensuring that the air pollution monitoring network is properly designed to capture the patterns of pollution and that all social demographics in the urban population are represented. An important aspect in characterizing air pollution patterns is scale in space and time which, along with pattern and process relationships, is a key subject in the field of landscape ecology. Thus, using multiple landscape ecological methods, this dissertation research begins by characterizing and quantifying the multi-scalar patterns of ozone (O3) and particulate matter (PM10) in the Phoenix, Arizona, metropolitan region. Results showed that pollution patterns are scale-dependent, O3 is a regionally-scaled pollutant at longer temporal scales, and PM10 is a locally-scaled pollutant with patterns sensitive to season. Next, this dissertation examines the monitoring network within Maricopa County. Using a novel multiscale indicator-based approach, the adequacy of the network was quantified by integrating inputs from various academic and government stakeholders. Furthermore, deficiencies were spatially defined and recommendations were made on how to strengthen the design of the network. A sustainability ranking system also provided new insight into the strengths and weaknesses of the network. Lastly, the study addresses the question of whether distinct social groups were experiencing inequitable exposure to pollutants - a key issue of distributive environmental injustice. A novel interdisciplinary method using multi-scalar ambient pollution data and hierarchical multiple regression models revealed environmental inequities between air pollutants and race, ethnicity, age, and socioeconomic classes. The results indicate that changing the scale of the analysis can change the equitable relationship between pollution and demographics. The scientific findings of the scale-dependent relationships among air pollution patterns, network design, and population demographics, brought to light through this study, can help policymakers make informed decisions for protecting the human health and the urban environment in the Phoenix metropolitan region and beyond. / Dissertation/Thesis / Ph.D. Biology 2014

Les milieux aquatiques sont les réceptacles finaux des pesticides organiques et inorganiques. Ainsi, des textes réglementaires fixant des objectifs afin de préserver et restaurer l’état des milieux aquatiques ont été établis (ex. Directive Cadre sur l’Eau). Ces textes réglementaires ou les programmes d'actions s'accompagnent de la mise en place de réseaux de suivi de la qualité des eaux. Ces suivis sont effectués via la réalisation de prélèvements ponctuels d'eau, fournissant une donnée souvent sujette à un manque de représentativité temporelle. Pour estimer de façon plus robuste une concentration moyenne dans le temps, des techniques d’échantillonnage passif ont été développées. Celles-ci permettent la pré-concentration in situ des contaminants et disposent d’une capacité intégrative sur plusieurs semaines. Ces travaux de thèse sont axés sur le Polar Organic Chemical Integrative Sampler (POCIS), largement utilisé pour l’échantillonnage des pesticides moyennement polaires et non ionisables (0<log Kow<4).Le premier volet de ces travaux de thèse avait pour objectif de tester la capacité du POCIS à intégrer de brèves variations de concentration en pesticides. Pour ce faire, une expérimentation simulant des pics de contamination d’intensités et de durées variables a été menée dans des conditions contrôlées de laboratoire. Cette expérimentation a démontré que la réactivité du POCIS face à de tels événements était dépendante des propriétés physico-chimiques des pesticides ciblés (notamment du log Kow) et de la durée d’exposition. Des profils d’accumulation différents ont été observés, avec deux phénomènes opposés survenus en début d’exposition, soit le « burst effect » ou le « lag effect ». Malgré ces deux phénomènes, le domaine d’applicabilité du POCIS a été mieux défini puisqu’il a été démontré que pour des pesticides caractérisés par un log Kow entre 2 et 4, les pics de contamination étaient bien pris en compte dans la concentration moyennée obtenue.Le second volet de ces travaux devait définir à large échelle l’apport du POCIS en complément des réseaux de suivi basés sur les prélèvements ponctuels. Dans ce contexte, 51 sites du réseau de contrôle DCE localisés sur les cours d’eau du bassin Adour-Garonne ont été échantillonnés 6 fois en 2016 via ces deux techniques. L’exploitation des données acquises pendant cette année de terrain s’est découpée en deux axes. Le premier avait pour objectif de comparer les informations fournis via les deux techniques. L’apport des caractéristiques intégratives du POCIS y a été démontré. En effet, le POCIS permet d’améliorer significativement le nombre de pesticides quantifiés ainsi que leur fréquence de quantification. De plus, il fournit une meilleure représentativité temporelle des niveaux de contamination mesurés, puisqu’il permet d’avoir une image plus réaliste des variations annuelles des concentrations en lien avec les usages des pesticides ciblés (saisonnalité). Ainsi, la combinaison de ces deux techniques a permis une meilleure caractérisation de la pression « pesticides » subie par le bassin Adour-Garonne.Le second axe visait à proposer une méthodologie d’exploitation automatisée permettant une interprétation visuelle et simple d’un jeu de données conséquent (> 10 000 données). Les données acquises avec les POCIS ont été utilisées pour réaliser des analyses multivariées, type « principal component analysis » et « hierarchical cluster analysis » afin de démontrer des liens entre occupation du sol et pesticides quantifiés. De plus, l’empreinte « pesticides » de chaque site a été établie. Ainsi, ce dernier axe a permis une meilleure caractérisation des zones les plus à risques ainsi qu’une identification rapide des sources potentielles.Ces travaux de thèse ont donc démontré des aspects fondamentaux et appliqués qui confirment l’intérêt du POCIS pour évaluer la qualité des eaux superficielles vis-à-vis des pesticides. / The aquatic environments are considered as the final receptacles of organic or inorganic pesticides. Thus, regulatory texts were established in order to preserve and restore the good status for the aquatic environments (e.g. Water Framework Directive). Currently, the conventional method for freshwater analysis is grab sampling several times per year with a lack of temporal representativeness. To overcome this issue, and in the aim of estimating a robust average concentration over time, passive sampling strategies have been developed. These samplers allow an in situ pre-concentration of contaminants and offer an integrative capacity of several weeks. This thesis focuses on the Polar Organic Chemical Integrative Sampler (POCIS), which is widely used for the sampling of moderately polar or no-ionizable pesticides (0<log Kow<4).The first part of this thesis aimed to test the POCIS capacity to integrate short pesticides contamination peaks. In this way, a laboratory controlled-conditions experiment which included pesticides contamination peaks of variable intensity and duration was performed over 14 days. This experiment proved that POCIS response depends on physico-chemical properties of the studied pesticides and also on the exposure duration. During the first part of the exposure period two different phenomena were observed, which were a “burst effect” or a “lag effect”. Despite these, short contamination peaks were well integrated in the time weighted average concentration, for pesticides with log Kow between 2 and 4.The second part of this thesis was to define, at a large scale, the contribution of POCIS as a complement to the monitoring networks based on grab samples. In this context, 51 monitoring stations located in the Adour-Garonne basin were sampled with these two techniques during 6 periods in 2016. The analysis of the large amount of data collected during this 1-year monitoring was divided into two axes. Firstly, information provided with POCIS and grab samples was compared. The contribution of the integrative capacity of POCIS was demonstrated; this capacity allowed us to obtain additional and complementary information to those of the monitoring networks. Indeed, POCIS improved significantly the number of quantified pesticides as well as their quantification frequency. Moreover, POCIS brought a better temporal representativeness of contamination levels, since it provided a more realistic picture of the annual variations in concentration levels related to the seasonality in the use of some pesticides. Thus, the combination of grab samples and POCIS provided a better assessment of pesticide contamination levels in the Adour-Garonne basin.The second axis aimed to propose an automated methodology allowing a visual and simple interpretation of a large dataset (> 10,000 data). Data acquired with POCIS were used to demonstrate correlations between land use and quantified pesticides. In this context, multivariate analyses, such as hierarchical clustering and principal component analyses, confirmed the relationship between land use in the watershed and the major pesticides quantified. Then, the "pesticide" fingerprint of each site was established. Finally, this last axis has made it possible to better characterize the sites most at risk and to quickly identify potential sources.This thesis work demonstrated fundamental and applied aspects, which confirm the interest of the POCIS in assessing the freshwater quality for pesticides.

The FDR (Frequency Disturbance Recorder) is a data acquisition device for the power system. The device is portable and can be used with any residential wall outlet for frequency data collection. Furthermore, the FDR transmits calculated frequency data to the web for access by authorized users via Ethernet connection. As a result, Virginia Tech implemented Frequency Monitoring Network (FNET) with these FDR devices. FNET is a collection of identical FDRs placed in different measurement sites to allow for data integration and comparison. Frequency is an important factor for power system control and stabilization. With funding and support provided by ABB, TVA and NSF the FDRs are placed strategically all over the United States for frequency analysis, power system protection and monitoring. The purpose of this study is to refine the current FDR hardware design and establish a new design that will physically fit all the components on one Printed Circuit Board (PCB). At the same time, the software that is to be implemented on the new board is to be kept similar if not the same as that of the current design. The current FDR uses the Axiom CME555 development board and it is interfaced to the external devices through its communication ports. Even through the CME555 board is able to meet the demands of the basic FDR operations, there are still several problems associated with this design. This paper will address some of those hardware problems, as well as propose a new board design that is specifically aimed for operations of FDR. / Master of Science