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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.
281

The Social Production of the Built Environment: the Case of the Townhouse in Harare, Zimbabwe

Jogi, Shasekant 21 May 2008 (has links)
This research is concerned with the social creation of built environments in the Third World. The absence of appropriate theoretical frameworks has hampered the research of Third World cities. Recently, however, the opportunity for applying concepts, that have to date been largely confined to the study of western cities, has increased provided they are organized in a suitable way. Drawing on concepts such as built environment, socio-spatial dialectic, and structure and agency, this research outlines and applies a framework for the study of Third World urbanization. In order to explore the interdependence between space and society this study "unpacks" the urban landscape of Harare, Zimbabwe. Working in the context of the culture of capitalism, the study traces the development of the southern African zonal urban system before establishing a typology of landscape ensembles through successive stages of the evolution of Zimbabwe's political economy. Within the current global epoch, the study focuses on a specific type of built environment -- the townhouse. As a repository of contested cultural ideas and practices, the townhouse stands at the center of often conflicting socio-economic groups defined collectively as a "structure of provision". Using interviews, archival research, and a survey questionnaire, an analysis of these groups which focuses on the production and consumption of the townhouse drew the following conclusions: On the production side, realtors have assumed a central co-ordinating role in the production of townhouses. Prior to the development of townhouses, the realtor played a more limited role in real estate market. With the emergence of the entrepreneurial developer and with the assistance of the architect, realtors have assumed a central co-ordinating role in the initiation, management, and marketing of the townhouse. Built within specific zones within the city and its suburbs, garden flats and townhouses occupy the wealthy areas of the city. On the consumption side, garden flats and townhouses are occupied by the "managerial bourgeoisie" who comprise wealthy Zimbabweans and expatriates who are predominantly White, managers and professionals. While they share some important similarities they can nevertheless, based on their consumption patterns, be divided into identifiable groups that are geographically distributed within Harare's wealthier areas. It was suggested that production and consumption are ultimately part of the same process that produces status symbols that drive the demand for consumer goods. Ultimately, however, garden flats and townhouses stand testimony not only to the wealth of their occupants, but to patterns of lifestyle reminiscent of the consumption ethic of their counterparts in the First World. In the context of a Third World city, however, their lifestyle with its show of wealth has, not surprisingly, generated concerns about safety and security among the community of garden flats and townhouse dwellers. These concerns are historically deeply imbedded not only in the region but in the culture of capitalism. It was ultimately concluded that, within the context of late capitalism, the southern African city shares similarities with its First World counterpart. / Ph. D.
282

Places for people: housing in historical context in Old Town Alexandria, Virginia

Marjakangas, Minna Kristiina January 1992 (has links)
The aim of this design thesis was to look carefully at the historical environment of the chosen site, and with the understanding developed from this exploration, to design a group of houses that would answer to the desires of the individual and the needs of the collective, or simply: to create places where people would wish to dwell. "Houses must be special places within places, separately the center of the world for their inhabitants, yet carefully related to the larger place in which they belong."¹ / Master of Architecture
283

<b>A multifaceted approach to weed management in organic sweetpotato systems</b>

Emmanuel Gonfatee Cooper (18405756) 18 April 2024 (has links)
<p dir="ltr">Sweetpotato (<i>Ipomoea batatas</i> L.) is a staple crop that provides nutritional benefits to humans globally, but it is subjected to yield loss when competing with weeds, especially during the early stage of establishment. Despite increased organic sweetpotato production in the United States, growers face challenges with limited weed management options and often resort to time-consuming and costly cultivation and hand-weeding. To address this challenge, experiments were developed to determine (1) the effect of sweetpotato cultivar on the critical weed-free period, (2) the effects of in-row plant spacing and cultivar selection on weed suppression and sweetpotato yield, and (3) the impact of buckwheat and silage tarps for row-middle weed control. 1) In 2022, field research was conducted at the Samuel G. Meigs Horticulture Research Farm (Meigs), Lafayette, IN, and at the Southwest Purdue Agricultural Center (SWPAC), Vincennes, IN to estimate the critical weed-free period for ‘Covington’, ‘Murasaki’, and ‘Monaco’ in the Midwest. The experiment was a split-plot design, with weed-free interval treatments as the main plot factor and cultivar as the subplot factor. Weeds were removed by hand and allowed to establish and compete with the crop beginning at 0, 14, 21, 28, 35, or 42 days after transplanting (DAP). As weed-free interval increased from 0 to 42 DAP, predicted total yield increased from 19 kg ha<sup>-1</sup> to 20,540 kg ha<sup>-1 </sup>for Covington, 3 kg ha<sup>-1</sup> to 11,407 kg ha<sup>-1</sup> for Monaco, and 125 kg ha<sup>-1 </sup>to 13,460 kg ha<sup>-1 </sup>for Murasaki at the Lafayette location. A threshold of ≤10% total yield reduction was achieved by maintaining sweetpotatoes weed-free 24 DAP for Covington, 20 DAP for Murasaki, and 33 DAP for Monaco. 2) In 2022 and 2023, studies were conducted at Meigs, Lafayette, IN and SWPAC, Vincennes, IN to evaluate in-row plant spacing and cultivars for weed control and sweetpotato yield. The experiment was a split-split plot design, with in-row spacings of 20, 30, and 40 cm as the main plot factor, weeding frequency (‘critical weed-free period’ and ‘weed free’) as the subplot factor, and sweetpotato cultivar (‘Covington’ and ‘Monaco’) as the sub-subplot factor. However, in 2022, we evaluated only in-row spacing and weeding frequency because of poor establishment of Monaco. In-row spacing had no significant effect on weed densities at 4, 5, and 6 WAP. As in-row spacing increased from 20 to 40 cm, total sweetpotato yield pooled across both locations in 2023 decreased from 30,223 to 21,209 kg ha<sup>-1</sup> for Covington and 24,370 to 20,848 kg ha<sup>-1</sup> for Monaco, however, jumbo yield increased for both cultivars. Findings from this study suggest that an in-row spacing of 20 cm may provide greater yield than the standard spacing, 30 cm, for both Monaco and Covington cultivars and could reduce weed interference through more rapid sweetpotato canopy closure. 3) The experiment was a randomized complete block design, with three row-middle treatments [tarp, buckwheat, and cultivation] and four replicates. Row-middle treatments were established immediately after transplanting ‘Covington’ slips 30 cm apart into raised bed plots consisting of a single row 6 m long and 2 m apart on-center. Buckwheat was planted three weeks after transplanting (WAP) at a rate of 108 kg ha<sup>-1</sup> in row-middle. Row-middles for the tarp treatment were covered for the entire growing season. Weed density at 6 WAP was 184 plants m<sup>-2</sup> for the buckwheat, and 162 plants m<sup>-2</sup> for the cultivation treatments. Total yield was 11,050 kg ha<sup>-1</sup> for the buckwheat, 19,790 kg ha<sup>-1</sup> for the cultivation, and 17,810 kg ha<sup>-1</sup> for the tarping treatments. Tarping effectively suppressed weeds and produced sweetpotato yields comparable to cultivation indicating potential for organic growers. Buckwheat yields were lower than those from tarping and cultivation.</p>
284

Automated Estimation of Forest Row Spacing and Detection of Clearances: An Experimental Study

Mohammad, Waled Khalid January 2024 (has links)
Background: This research explores the integration of satellite imagery and imageprocessing techniques to innovate forest monitoring methods. Traditional approachesoften fall short in scale and efficiency, necessitating enhanced techniques for accurateforest structure analysis. Objectives: The main goal is to develop a software prototype capable of automat-ing the measurement of tree row spacing and detecting clearing areas within forests,thereby facilitating more informed and efficient forest management and conservationefforts. Methods: The study employed computer vision techniques and image processingalgorithms using OpenCV to process high-resolution satellite images. The develop-ment and testing of the prototype involved iterative enhancements to refine accuracyand functionality. Results: The findings demonstrate that the prototype successfully identifies andmeasures forest structural features with high accuracy, confirming the effectivenessof integrating computational techniques with ecological monitoring practices. Conclusions: The successful application of satellite imagery and image processingsignificantly enhances forest monitoring capabilities, promoting sustainable forestmanagement. This research underscores the potential of technology to transformenvironmental conservation efforts by providing detailed, reliable data that supportsproactive management strategies. / Bakgrund: Denna forskning utforskar integrationen av satellitbilder och avanceradebildbehandlingstekniker för att innovera metoder för skogsövervakning. Traditionellatillvägagångssätt är ofta bristfälliga i skala och effektivitet, vilket kräver förbättradetekniker för noggrann analys av skogsstrukturer. Syften: Huvudmålet är att utveckla en programvaruprototyp som kan automatiseramätningen av trädradsavstånd och upptäcka kalhyggen inom skogar, vilket underlät-tar mer informerad och effektiv skogsförvaltning och bevarandeinsatser.Metoder: Studien använde datorsynstekniker och bildbehandlingsalgoritmer medOpenCV för att bearbeta högupplösta satellitbilder. Utvecklingen och testningen avprototypen involverade iterativa förbättringar för att förfina noggrannhet och funktionalitet. Resultat: Resultaten visar att prototypen framgångsrikt identifierar och mäterskogsstrukturella egenskaper med hög noggrannhet, vilket bekräftar effektivitetenav att integrera avancerade datatekniker med ekologiska övervakningsmetoder. Slutsatser: Den framgångsrika tillämpningen av satellitbilder och bildbehandlingförbättrar avsevärt möjligheterna till skogsövervakning och främjar hållbar skogsför-valtning. Denna forskning understryker teknikens potential att transformera miljöbe-varande insatser genom att tillhandahålla detaljerade, tillförlitliga data som stöderproaktiva förvaltningsstrategie
285

Design And Performance Analysis Of A New Family Of Wavelength/Time Codes For Fiber-Optic CDMA Networks

Shivaleela, E S 07 1900 (has links)
Asynchronous multiplexing schemes are efficient than synchronous schemes, in a bursty traffic environment of multiple access local area network (LAN), as fixed bandwidth is not allocated among the users and there is no access delay. Fiber- Optic Code-Division Multiple Access (FO-CDMA) is one such asynchronous multiplexing scheme suitable for high speed LAN networks. While FO-CDMA offers potential benefits it also faces challenges in three diverse areas which are 1) coding algorithms and schemes 2) advanced encoding and decoding hardware and 3) network architecture. In this thesis, as a solution to the first challenge, we propose the design and construction of a new family of codes, wavelength/time multiple-pulses-per-row (W/T MPR) codes. These codes have good cardinality, spectral efficiency and minimal cross-correlation values. Performance analysis of the W/T MPR codes is carried out and found to be superior to other codes. In unipolar 1-D Optical Orthogonal Codes (OOCs) proposed by Salehi et al., the ratio of code length/code weight grows rapidly as the number of users is increased for a reasonable weight. Hence, for a given pulse width, the data rate decreases or in other words for a given data rate very narrow pulses have to be used, because of which dispersion effects will be dominant. To overcome the drawbacks of non-linear effects in large spread sequences of 1-D unipolar codes in FO-CDMA networks, several two-dimensional codes have been proposed. Wavelength-time (W/T) encoding of the two-dimensional codes is practical in FO-CDMA networks. W/T codes reported so far can be classified mainly into two types: 1) hybrid sequences, where one type of sequence is crossed with another to improve the cardinality and correlation properties and 2) matrix codes, 1-D sequences converted to 2-D codes or 2-D codes by construc- tion, to reduce the ’time’ spread of the sequences/codes. Prime-hop and eqc/prime W/T hybrid codes have been proposed where one type of sequence is crossed with another to improve the cardinality and correlation properties. Other constructions deal with conversion of 1-D sequences to 2-D codes either by using Chinese remainder theorem or folding GoLomb rulers. W/T single-pulse-per-row (W/T SPR) codes are 2-D codes constructed using algebraic method Addition Modulo Group operation. Motivation for this work: To design a family of 2-D codes which have the design choice of length of one dimension over the other, and also have better cardinality, spectral efficiency and also low cross-correlation values (thereby have low BER) than that of the reported unipolar 2-D codes. In this thesis, we describe the design principles of W/T MPR codes, for in- coherent FO-CDMA networks, which have good cardinality, spectral efficiency and minimal cross-correlation values. Another feature of the W/T MPR codes is that the aspect ratio can be varied by trade off between wavelength and temporal lengths. We lay down the necessary conditions to be satisfied by W/T MPR codes to have minimal correlation values of unity. We analytically prove the correlation results and also verify by simulation (of the codes) using Matlab software tool. We also discuss the physical implementation of the W/T MPR FO-CDMA network with optical encoding and decoding. We show analytically that when distinct 1-D OOCs of a family are used as the row vectors of a W/T MPR code, it will have off-peak autocorrelation equal to ‘1’. An expression for the upper bound on the cardinality of W/T MPR codes is derived. We also show that 1-D OOCs and W/T SPR codes are the limiting cases of W/T MPR codes. Starting with distinct 1-D OOCs, of a family, as row vectors, we propose a greedy algorithm, for the construction of W/T MPR codes and present the repre- sentations of the results. An entire W/T MPR code family, generated using greedy algorithm, is simulated for various number of interfering users. Performance analysis of the W/T MPR codes and their limiting cases is carried out for various parameter variations such as the dimensions of wavelength, time and weight of the code. We evaluate the performance in terms of BER, capacities of the networks, temporal lengths needed (to achieve a given BER). Multiple access interference (MAI) signal can be reduced, by using a bistable optical hard-limiter device in the W/T MPR code receiver, by eliminating those signal levels which exceed a certain preset level. Performance analysis of the W/T MPR codes and their limiting cases is studied for various parameter variations. For given wavelength × time dimensions, we compare various W/T codes, whose cardinalities are known, and show that W/T MPR family of codes have better cardinality and spectral efficiency than the other (reported) W/T codes. As W/T MPR codes are superior to other W/T codes in terms of cardinality, spectral efficiency, low peak cross-correlation values and at the same time have good performance, makes it a suitable coding scheme for incoherent FO-CDMA access networks.
286

Effects of white-tailed deer herbivory on a tallgrass prairie remnant

Gooch, Scott 11 January 2010 (has links)
A study was conducted to determine what impact high white-tailed deer (Odocoileus virginianus) densities were having on the native grasslands of a tallgrass: aspen forest tract embedded within an agro-urban setting. Due to excessive spring moisture, row-crops were unavailable the first year. Using microhistological fecal analysis to determine dietary composition, deer were assessed to be placing the site’s favoured native plant species at risk of extirpation. Measuring woody stem abundance and height along and near the prairie: forest ecotone, deer were found to restructure woody growth but not directly influence encroachment rates. Indirectly, however, deer facilitated forest encroachment and prairie degradation through seed dispersal, nitrogen deposition, gap-dynamics, and trampling. Comparing dietary composition to nutritional data, deer grazed to maximize fitness, selecting foods high in IVDMD, minimizing energy expenditure, and optimizing CP. High crop CP was offset by intensively grazing particular native plants. ADF was an effective nutritional marker, not AIA.
287

Effects of white-tailed deer herbivory on a tallgrass prairie remnant

Gooch, Scott 11 January 2010 (has links)
A study was conducted to determine what impact high white-tailed deer (Odocoileus virginianus) densities were having on the native grasslands of a tallgrass: aspen forest tract embedded within an agro-urban setting. Due to excessive spring moisture, row-crops were unavailable the first year. Using microhistological fecal analysis to determine dietary composition, deer were assessed to be placing the site’s favoured native plant species at risk of extirpation. Measuring woody stem abundance and height along and near the prairie: forest ecotone, deer were found to restructure woody growth but not directly influence encroachment rates. Indirectly, however, deer facilitated forest encroachment and prairie degradation through seed dispersal, nitrogen deposition, gap-dynamics, and trampling. Comparing dietary composition to nutritional data, deer grazed to maximize fitness, selecting foods high in IVDMD, minimizing energy expenditure, and optimizing CP. High crop CP was offset by intensively grazing particular native plants. ADF was an effective nutritional marker, not AIA.
288

We're changing the way we do business a critical analysis of the Dixie Chicks and the country music industry /

Stokes, Justine Frances. January 2008 (has links)
Thesis (M.A.)--Miami University, Dept. of Communication, 2008. / Title from first page of PDF document. Includes bibliographical references (p. 97-105).
289

Workload- and Data-based Automated Design for a Hybrid Row-Column Storage Model and Bloom Filter-Based Query Processing for Large-Scale DICOM Data Management / Conception automatisée basée sur la charge de travail et les données pour un modèle de stockage hybride ligne-colonne et le traitement des requêtes à l’aide de filtres de Bloom pour la gestion de données DICOM à grande échelle

Nguyen, Cong-Danh 04 May 2018 (has links)
Dans le secteur des soins de santé, les données d'images médicales toujours croissantes, le développement de technologies d'imagerie, la conservation à long terme des données médicales et l'augmentation de la résolution des images entraînent une croissance considérable du volume de données. En outre, la variété des dispositifs d'acquisition et la différence de préférences des médecins ou d'autres professionnels de la santé ont conduit à une grande variété de données. Bien que la norme DICOM (Digital Imaging et Communication in Medicine) soit aujourd'hui largement adoptée pour stocker et transférer les données médicales, les données DICOM ont toujours les caractéristiques 3V du Big Data: volume élevé, grande variété et grande vélocité. En outre, il existe une variété de charges de travail, notamment le traitement transactionnel en ligne (en anglais Online Transaction Processing, abrégé en OLTP), le traitement analytique en ligne (anglais Online Analytical Processing, abrégé en OLAP) et les charges de travail mixtes. Les systèmes existants ont des limites concernant ces caractéristiques des données et des charges de travail. Dans cette thèse, nous proposons de nouvelles méthodes efficaces pour stocker et interroger des données DICOM. Nous proposons un modèle de stockage hybride des magasins de lignes et de colonnes, appelé HYTORMO, ainsi que des stratégies de stockage de données et de traitement des requêtes. Tout d'abord, HYTORMO est conçu et mis en œuvre pour être déployé sur un environnement à grande échelle afin de permettre la gestion de grandes données médicales. Deuxièmement, la stratégie de stockage de données combine l'utilisation du partitionnement vertical et un stockage hybride pour créer des configurations de stockage de données qui peuvent réduire la demande d'espace de stockage et augmenter les performances de la charge de travail. Pour réaliser une telle configuration de stockage de données, l'une des deux approches de conception de stockage de données peut être appliquée: (1) conception basée sur des experts et (2) conception automatisée. Dans la première approche, les experts créent manuellement des configurations de stockage de données en regroupant les attributs des données DICOM et en sélectionnant une disposition de stockage de données appropriée pour chaque groupe de colonnes. Dans la dernière approche, nous proposons un cadre de conception automatisé hybride, appelé HADF. HADF dépend des mesures de similarité (entre attributs) qui prennent en compte les impacts des informations spécifiques à la charge de travail et aux données pour générer automatiquement les configurations de stockage de données: Hybrid Similarity (combinaison pondérée de similarité d'accès d'attribut et de similarité de densité d'attribut) les attributs dans les groupes de colonnes; Inter-Cluster Access Similarity est utilisé pour déterminer si deux groupes de colonnes seront fusionnés ou non (pour réduire le nombre de jointures supplémentaires); et Intra-Cluster Access La similarité est appliquée pour décider si un groupe de colonnes sera stocké dans une ligne ou un magasin de colonnes. Enfin, nous proposons une stratégie de traitement des requêtes adaptée et efficace construite sur HYTORMO. Il considère l'utilisation des jointures internes et des jointures externes gauche pour empêcher la perte de données si vous utilisez uniquement des jointures internes entre des tables partitionnées verticalement. De plus, une intersection de filtres Bloom (intersection of Bloom filters, abrégé en ) est appliqué pour supprimer les données non pertinentes des tables d'entrée des opérations de jointure; cela permet de réduire les coûts d'E / S réseau. (...) / In the health care industry, the ever-increasing medical image data, the development of imaging technologies, the long-term retention of medical data and the increase of image resolution are causing a tremendous growth in data volume. In addition, the variety of acquisition devices and the difference in preferences of physicians or other health-care professionals have led to a high variety in data. Although today DICOM (Digital Imaging and Communication in Medicine) standard has been widely adopted to store and transfer the medical data, DICOM data still has the 3Vs characteristics of Big Data: high volume, high variety and high velocity. Besides, there is a variety of workloads including Online Transaction Processing (OLTP), Online Analytical Processing (OLAP) and mixed workloads. Existing systems have limitations dealing with these characteristics of data and workloads. In this thesis, we propose new efficient methods for storing and querying DICOM data. We propose a hybrid storage model of row and column stores, called HYTORMO, together with data storage and query processing strategies. First, HYTORMO is designed and implemented to be deployed on large-scale environment to make it possible to manage big medical data. Second, the data storage strategy combines the use of vertical partitioning and a hybrid store to create data storage configurations that can reduce storage space demand and increase workload performance. To achieve such a data storage configuration, one of two data storage design approaches can be applied: (1) expert-based design and (2) automated design. In the former approach, experts manually create data storage configurations by grouping attributes and selecting a suitable data layout for each column group. In the latter approach, we propose a hybrid automated design framework, called HADF. HADF depends on similarity measures (between attributes) that can take into consideration the combined impact of both workload- and data-specific information to generate data storage configurations: Hybrid Similarity (a weighted combination of Attribute Access and Density Similarity measures) is used to group the attributes into column groups; Inter-Cluster Access Similarity is used to determine whether two column groups will be merged together or not (to reduce the number of joins); and Intra-Cluster Access Similarity is applied to decide whether a column group will be stored in a row or a column store. Finally, we propose a suitable and efficient query processing strategy built on top of HYTORMO. It considers the use of both inner joins and left-outer joins. Furthermore, an Intersection Bloom filter () is applied to reduce network I/O cost.We provide experimental evaluations to validate the benefits of the proposed methods over real DICOM datasets. Experimental results show that the mixed use of both row and column stores outperforms a pure row store and a pure column store. The combined impact of both workload-and data-specific information is helpful for HADF to be able to produce good data storage configurations. Moreover, the query processing strategy with the use of the can improve the execution time of an experimental query up to 50% when compared to the case where no is applied.
290

Energy-Efficient Key/Value Store

Tena, Frezewd Lemma 11 September 2017 (has links) (PDF)
Energy conservation is a major concern in todays data centers, which are the 21st century data processing factories, and where large and complex software systems such as distributed data management stores run and serve billions of users. The two main drivers of this major concern are the pollution impact data centers have on the environment due to their waste heat, and the expensive cost data centers incur due to their enormous energy demand. Among the many subsystems of data centers, the storage system is one of the main sources of energy consumption. Among the many types of storage systems, key/value stores happen to be the widely used in the data centers. In this work, I investigate energy saving techniques that enable a consistent hash based key/value store save energy during low activity times, and whenever there is an opportunity to reuse the waste heat of data centers.

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