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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.
61

An Exploration of Wireless Networking and the Management of Associated Security Risk

Collins, Helen Loretta 01 January 2015 (has links)
The rapid expansion of wireless information technology (IT) coupled with a dramatic increase in security breaches forces organizations to develop comprehensive strategies for managing security risks. The problem addressed was the identification of security risk management practices and human errors of IT administrators, putting the organization at risk for external security intrusion. The purpose of this non-experimental quantitative study was to investigate and determine the security risk assessment practices used by IT administrators to protect the confidentiality and integrity of the organization's information. The research questions focused on whether the security risk management practices of IT administrators met or exceeded the minimally accepted practices and standards for wireless networking. The security risk assessment and management model established the theoretical framework. The sample was 114 participants from small to medium IT organizations comprised of security engineers, managers, and end users. Data collection was via an online survey. Data analysis included both descriptive and inferential statistical methods. The results revealed that greater than 80% of participants conducted appropriate risk management and review assessments. This study underscored the need for a more comprehensive approach to managing IT security risks. IT managers can use the outcome of this study as a benchmark for evaluating their current risk assessment procedures. Experiencing security breaches in organizations may be inevitable. However, when organizations and industry leaders can greatly reduce the cost of a data breach by developing effective risk management plans that lead to better security outcomes, positive social change can be realized.
62

會計資訊系統對資訊使用者及競爭策略影響之研究 / A Study on AIS's Effect on Information User and Competitive Strategy

吳東霖, Wu, Tong-Lin Unknown Date (has links)
隨著資訊科技的發展,會計資訊系統的功能愈來愈強,所提供的資訊也不限於財務報表還包括了管理報告,本研究探討會計資訊系統提供何種資訊給使用者、會計資訊系統所面臨的問題、及會計資訊系統對於企業實現其競爭策略的幫助。 本研究以台灣五家上市公司為樣本,實地訪談企業資訊部門之人員來探討上述的問題,研究結果發現: 1. 五家受訪企業會計資訊系統電腦化皆有十年以上的歷史,能夠提供企業使用者日常業務所需要的大部份資訊。 2. 資訊使用者對於會計資訊系統不滿意之處有三:(1)系統無法滿足使用者所有的資訊需求,(2)系統開發改善速度緩慢,(3)需求的申請遭到資訊部門的拒絕。 3. 受訪人員表示,會計資訊系統能提供使用者決策之攸關資訊,對企業競爭策略之實現有幫助。 / In recent yrear, the function of AIS has been improved. AIS can provide not only financial reports, but also managerial reports. This study empirically examines of 5 enterprises' AIS to understand the AIS in Taiwan. The empirical results show that: 1.AIS could provide user useful information to help decision making. 2.AIS improve process is not fast enough to satisfy users' needs. 3.AIS could help enterprises' Competitive Strategy.
63

The role of transcription factor Pitx1 and its regulation by hypoxia in Adolescent Idiopathic Scoliosis

Suvarnan, Lakshmi 06 1900 (has links)
La scoliose idiopathique de l’adolescent (SIA) est définie comme une courbure de la colonne vertébrale supérieure à 10 degrés, qui est de cause inconnue et qui affecte de façon prépondérante les adolescents. Des études précédentes sur des modèles murins ont démontré une inactivation partielle du gène Pitx1. Cette inactivation partielle provoque une déformation spinale sévère lors du développement des souris Pitx1+/-, ce qui est grandement similaire au phénotype de la SIA. En se basant sur ces observations, nous postulons que la perte de fonction de Pitx1 pourrait avoir un rôle dans la SIA et pourrait être régulée par des mécanismes moléculaires spécifiques. En effet, des études faites sur l’expression de Pitx1 révèlent une perte de son expression dans les ostéoblastes dérivés de patients SIA au niveau de l’ARNm. Nous émettons l’hypothèse que la perte de Pitx1 dans la SIA pourrait être déclenchée par des facteurs hypoxiques puisqu’il est connu que Pitx1 est réprimé par l’hypoxie et que HIF-2 alpha est surexprimés dans les ostéoblastes des patients SIA même dans des conditions normoxiques. De plus, nous avons découvert une mutation dans le domaine ODD des HIF-1 alpha chez certains patients SIA (3,1%). Une fonction connue de ce domaine est de stabiliser et d’augmenter l’activité transcriptionnelle de HIF-1 alpha dans des conditions normoxiques. Nous avons confirmé, par la technique EMSA, l’existence d’un élément de réponse fonctionnel à l’hypoxie au niveau du promoteur de Pitx1. Cependant, des co-transfections avec des vecteurs d’expression pour HIF-1 alpha et HIF-2 alpha, en présence de leur sous-unité beta ARNT, ont conduit à une activation du promoteur de Pitx1 dans la lignée cellulaire MG-63 ainsi que dans les ostéoblastes des sujets contrôles. Il est intéressant de constater qu’aucune activité du promoteur de Pitx1 dans les ostéoblastes SIA n’a été observée, même après la co-expression de HIF-2 alpha et ARNT, confirmant le fait que l’expression de Pitx1 est abrogée dans la SIA. Dans l’ensemble, nos résultats démontrent un rôle important de Pitx1 dans la SIA et une possible régulation par des facteurs hypoxiques. / Adolescent Idiopathic Scoliosis is a lateral curvature of the spine greater than 10 degrees, with an unknown cause, affecting primarily adolescents. Previous mouse model studies showed that partial inactivation of Pitx1 gene resulted in the development of severe spinal deformities in Pitx1 +/- mice, which is strikingly similar to the AIS phenotype. Based on this observation, we postulated that loss of Pitx1 function might have a role in AIS and could be regulated through specific molecular mechanisms. Indeed, expression studies revealed a loss of Pitx1 expression in osteoblasts derived from AIS patients, at the mRNA level. We hypothesized that the loss of Pitx1 in AIS could be triggered by hypoxic factors, since Pitx1 is known to be repressed by hypoxia and that HIF-2 alpha was up regulated in AIS osteoblasts even under normoxic conditions. Also, we found a mutation in the ODD domain of HIF-1 alpha in some AIS patients (3.1%), which is known to stabilize and enhance HIF-1 alpha transcriptional activity in normoxic conditions. We confirmed through EMSA the existence of a functional hypoxia response element on Pitx1 promoter. However, co-transfection assays with HIF-1 alpha and HIF-2 alpha expression vectors in the presence of their beta subunit ARNT led to the activation of Pitx1 promoter in human osteoblast cell line MG-63 cells and osteoblasts from control subjects. Interestingly, no Pitx1 promoter activity was observed in AIS osteoblasts, even after the co expression of HIF2 alpha and ARNT, consolidating the fact that Pitx1 expression is abrogated in AIS. Taken together, our findings show an important role for Pitx1 in AIS and hypoxic factors could be one of its regulators.
64

Atlantic Ais in the Sixteenth and Seventeenth Centuries: Maritime Adaptation, Indigenous Wrecking, and Buccaneer Raids on Florida’s Central East Coast

Ferdinando, Peter J 26 March 2015 (has links)
The Ais were a Native American group who lived along the Atlantic shoreline of Florida south of Cape Canaveral. This coastal population’s position adjacent to a major shipping route afforded them numerous encounters with the Atlantic world that linked Europe, Africa, the Caribbean, and the Americas. Through their exploitation of the goods and peoples from the European shipwrecks thrown ashore, coupled with their careful manipulation of other Atlantic contacts, the Ais polity established an influential domain in central east Florida during the sixteenth and seventeenth centuries. The pre-contact peoples of Florida’s east coast, including the ancestors of the Ais, practiced a maritime adaptation concentrated on the exploitation of their bountiful riverine, estuarine, and marine environments. The Ais then modified their maritime skills to cope with the opportunities and challenges that accompanied European contact. Using their existing aquatic abilities, they ably salvaged goods and castaways from the Spanish, French, English, and Dutch vessels dashed on the rocks and reefs of Florida’s coast. The Ais’ strategic redistribution of these materials and peoples to other Florida Native Americans, the Spaniards of St. Augustine, and other passing Europeans gained them greater influence. This process, which I call indigenous wrecking, enabled the Ais to expand their domain on the peninsula. Coastal Florida Native Americans’ maritime abilities also attracted the attention of Europeans. In the late seventeenth century, English buccaneers and salvagers raided Florida’s east coast to capture indigenous divers, whom they sent to work the wreck of a sunken Spanish treasure ship located in the Bahamas. The English subsequently sold the surviving Native American captives to other Caribbean slave markets. Despite population losses to such raids, the Ais and other peoples of the east coast thrived on Atlantic exchange and used their existing maritime adaptation to resist colonial intrusions until the start of the eighteenth century. This dissertation thus offers a narrative about Native Americans and the Atlantic that is unlike most Southeastern Indian stories. The Ais used their maritime adaptation and the process of indigenous wrecking to engage and exploit the arriving Atlantic world. In the contact era, the Ais truly became Atlantic Ais.
65

The potential benefit of SMART load limiters in European frontal impacts

Ekambaram, Karthikeyan January 2016 (has links)
In Europe, the deployment characteristics of frontal crash restraints are generally optimised to best protect an average young male, since a 50th percentile male dummy is used in a stylised frontal impact scenario. These single point restraint systems may not provide similar levels of effectiveness when the crash scenarios vary with respect to the regulatory and consumer crash test procedures. Previous research has demonstrated that varying restraint deployment characteristics according to occupant and crash variation can provide further injury reduction in frontal impacts. This thesis reports the investigation conducted to assess the potential real world injury reduction benefit of smart restraint systems in frontal impacts. The intelligent capability of the restraint was achieved by varying the seat belt load limiter (SBL) threshold, according to the frontal crash scenario. Real world accident data (CCIS) were analysed to identify the target population of vehicle occupants and frontal impact scenarios where employing smart load limiters could be most beneficial, particularly in reducing chest injury risk. From the accident sample, the chest was the most frequently injured body region at an AIS 2+ level in frontal impacts (7% of front seat occupants). The proportion of older vehicle front seat occupants (>64 years old) with AIS 2+ injury was also greater than the proportion of younger occupants. Additionally, older occupants were more likely to sustain seat belt induced serious chest injury in low and moderate speed frontal crashes. Numerical simulations using MADYMO software were conducted to examine the effect of varying the load limiter thresholds on occupant kinematics and injury outcome in frontal impacts. Generic baseline driver and front passenger numerical models were developed using a 50th percentile dummy and were adapted to accommodate a 5th and 95th percentile dummy. Simulations were performed where the load limiter threshold was varied in five frontal impact scenarios which were selected to cover as wide a range of real frontal crash conditions as possible. From the simulation results, it was found that for both the 50th and 95th percentile dummy in front seating positions (driver and passenger), the low SBL provided the best chest injury protection, without increasing the risk to other body regions. In severe impacts, the low SBL allowed the dummy to move further towards the front facia, thus increasing the chance of occupant hard contact with the vehicle interiors. The Smart load limiters predicted no injury risk reduction for the 5th percentile drivers, who are shorter and tend to sit closer to the steering wheel. The potential injury reduction of the smart load limiters was quantified by applying the estimated injury risk reduction from the simulation to the real world accident data sample. Thoracic injury predictions from the simulations were converted into injury probability values using AIS 2+ age dependent thoracic risk curves which were developed and validated based on a methodology proposed by Laituri et al. (2005). Real world benefit was quantified using the predicted relative AIS 2+ risk reduction and assuming an appropriate adaptive system was fitted to all the cars in the real world sample. When applying the AIS 2+ risk reduction findings to the weighted accident data sample, the risk of sustaining an AIS 2+ seat belt injury reduced from 1.3% to 0.9% for younger front seat occupants, 7.6% to 5.0% for middle aged front seat occupants and 13.1% to 8.6% for the older front seat occupants. The research findings clearly demonstrate a chest injury reduction benefit across all age groups when the load limiter characteristics are varied. It suggests that employing a smart load limiter in a vehicle would not only benefit older occupants but also middle aged and young occupants. The benefit does appear to be most pronounced for older occupants, since the older population is more vulnerable to chest injury. As the older population of car users is rapidly rising, the benefits of smarter systems can only increase in the future.
66

Comparing CNN methods for detection and tracking of ships in satellite images / Jämförelse av CNN-baserad machine learning för detektion och spårning av fartyg i satellitbilder

Torén, Rickard January 2020 (has links)
Knowing where ships are located is a key factor to support safe maritime transports, harbor management as well as preventing accidents and illegal activities at sea. Present international solutions for geopositioning in the maritime domain exist such as the Automatic Identification System (AIS). However, AIS requires the ships to constantly transmit their location. Real time imaginary based on geostationary satellites has recently been proposed to complement the existing AIS system making locating and tracking more robust. This thesis investigated and compared two machine learning image analysis approaches – Faster R-CNN and SSD with FPN – for detection and tracking of ships in satellite images. Faster R-CNN is a two stage model which first proposes regions of interest followed by detection based on the proposals. SSD is a one stage model which directly detects objects with the additional FPN for better detection of objects covering few pixels. The MAritime SATellite Imagery dataset (MASATI) was used for training and evaluation of the candidate models with 5600 images taken from a wide variety of locations. The TensorFlow Object Detection API was used for the implementation of the two models. The results for detection show that Faster R-CNN achieved a 30.3% mean Average Precision (mAP) while SSD with FPN achieved only 0.0005% mAP on the unseen test part of the dataset. This study concluded that Faster R-CNN is a candidate for identifying and tracking ships in satellite images. SSD with FPN seems less suitable for this task. It is also concluded that the amount of training and choice of hyper-parameters impacted the results.
67

Einführung eines auf DIMAG basierenden digitalen Langzeitarchivs

Seibicke, Sarah 29 March 2022 (has links)
Der Vortrag beleuchtet den Aufbau der digitalen Infrastruktur auf der Grundlage eines einheitlichen Archivinformationssystems. Alle bayrischen Universitätsarchive nutzen das AIS ActaPro. Die Umsetzung des Magazins erfolgt auf der Grundlage von DIMAG auf zwei redundanten Storage-Systemen. / The presentation highlights the development of the digital infrastructure based on a unified archive information system. All Bavarian university archives use the AIS ActaPro. The implementation of the magazine is based on DIMAG on two redundant storage systems.
68

Pursuing More Aggressive Timelines in the Surgical Treatment of Traumatic Spinal Cord Injury (TSCI): A Retrospective Cohort Study with Subgroup Analysis

Bock, Tobias, Heller, Raban Arved, Haubruck, Patrick, Raven, Tim Friedrich, Pilz, Maximilian, Moghaddam, Arash, Biglari, Bahram 04 May 2023 (has links)
Background: The optimal timing of surgical therapy for traumatic spinal cord injury (TSCI) remains unclear. The purpose of this study is to evaluate the impact of “ultra-early” (<4 h) versus “early” (4–24 h) time from injury to surgery in terms of the likelihood of neurologic recovery. Methods: The effect of surgery on neurological recovery was investigated by comparing the assessed initial and final values of the American Spinal Injury Association (ASIA) Impairment Scale (AIS). A post hoc analysis was performed to gain insight into different subgroup regeneration behaviors concerning neurological injury levels. Results: Datasets from 69 cases with traumatic spinal cord injury were analyzed. Overall, 19/46 (41.3%) patients of the “ultra-early” cohort saw neurological recovery compared to 5/23 (21.7%) patients from the “early” cohort (p = 0.112). The subgroup analysis revealed differences based on the neurological level of injury (NLI) of a patient. An optimal cutpoint for patients with a cervical lesion was estimated at 234 min. Regarding the prediction of neurological improvement, sensitivity was 90.9% with a specificity of 68.4%, resulting in an AUC (area under the curve) of 84.2%. In thoracically and lumbar injured cases, the estimate was lower, ranging from 284 (thoracic) to 245 min (lumbar) with an AUC of 51.6% and 54.3%. Conclusions: Treatment within 24 h after TSCI is associated with neurological recovery. Our hypothesis that intervention within 4 h is related to an improvement in the neurological outcome was not confirmed in our collective. In a clinical context, this suggests that after TSCI there is a time frame to get the right patient to the right hospital according to advanced trauma life support (ATLS) guidelines.
69

Addressing Challenges with Big Data for Maritime Navigation: AIS Data within the Great Lakes System

Dhar, Samir January 2016 (has links)
No description available.
70

Ombyggnation av en fördelningsstation : Övergripande konceptförslag för spänningsutförande 130-10 kV

Wahlström, John January 2020 (has links)
Detta arbete har utförts hos Varberg Energi AB och syftat till att presentera olika koncept som alternativ till konventionella 130 kV luftisolerade fördelningsstationer. Arbetet är tänkt att kunna vara en del i en uppdragsbeskrivning för en kommande ombyggnation. De alternativ som står tillbuds bygger ofta på att någon eller flera komponenter innehåller svavelhexafluorid, SF6, vilken har en stor negativ påverkan på växthuseffekten om den släpps ut i atmosfären. De alternativ av komponenter, exempelvis brytare, som inte innehåller SF6 är få och väsentligt mycket dyrare. Dock är fortfarande konceptlösningar som använder sig av luft som isolationsmedium till komponenter som inte är brytare, frånskiljare eller dylikt de billigaste.  Alternativen som framkommit i denna rapport och studerats närmare är ABB:s Urban-koncept, GIS med SF6 och Siemens Blue GIS med renad luft och vakuumbrytare. Fokus har varit lösningarnas beskaffenhet gällande säkerhet för tredje man, enkelhet i underhåll, klimatpåverkan och tillförlitlighet. Önskvärt är en helhetslösning där underhåll eller reparationer kan utföras i de olika facken i 130 kV-stationen utan att det påverkar driften och orsakar ett avbrott. Att finna en lösning som inte kräver SF6-gas i någon del av fördelningsstationen ger många lättnader i regelverk, mindre övervakning och kostnader förknippade med denna. En balansgång behöver göras mellan ekonomiska intressen, miljöpåverkan, inspektionsintervall, felavhjälpning och eventuella framtida miljökrav för högspänningsanläggningar. Det förstärkta sabotageskyddet som en byggnad ger har varit en klar fördel som lyfts fram hos de besökta anläggningarna. Vid val av konceptlösning kan storleken hos och kompetensen inom den egna organisationen vara en faktor att ta hänsyn till. Även utformning och val av lösning för tidigare och framtida stationer kan behöva tas hänsyn till.

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