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Study on a resource-saving cloud based long-term ECG monitoring system using machine learning algorithmsCheng, Ping 19 April 2018 (has links)
Electrocardiogram (ECG) records the electrical impulses from myocardium, reflects the underlying dynamics of the heart and has been widely exploited to detect and identify cardiac arrhythmias. This dissertation examines a resource-saving cloud based long-term ECG (CLT-ECG) monitoring system which consists of an ECG raw data acquisition system, a mobile device and a serve. Three issues that are critically pertaining to the effectiveness and efficiency of the monitoring system are studied: the detection of life-threatening arrhythmias, the discrimination of normal and abnormal heartbeats to facilitate the resource-saving operation and the multi-class heartbeat classification algorithm for non-life-threatening arrhythmias.
The detection algorithm for life-threatening ventricular arrhythmias, which is critical
to saving patients’ lives, is investigated by exploiting personalized features. Two new personalized features, namely, aveCC and medianCC, are extracted based on the correlation coefficients between a patient-specific regular QRS-complex template and his/her real-time ECG data, characterizing subtle differences in the QRS complexes among different people. A small set of the most effective features is selected for efficient performance and real-time operation using Support Vector Machines (SVMs). The effectiveness of the proposed algorithm is validated in enhancing the performance under both the record-based and database-based data divisions. The classification algorithm achieves results outperforming the existing classification performances using top-two or top-three features.
A novel patient-specific arrhythmia detection algorithm, which discriminates the normal
and abnormal heartbeats, is proposed using One-Class SVMs. Conventionally, CLT-ECG systems are used to solve problems such as the portable problem and the difficulty of capturing the intermittent arrhythmias. However, CLT-ECG systems are subject to several practical limitations: battery power restriction, network congestion and heavily redundant ECG data. To overcome these problems, a resource-saving CLT-ECG system is studied, in which a novel arrhythmia detection algorithm closely related to the resource-saving rate is proposed and examined in detail. The proposed arrhythmia detection algorithm explores two types of variations: waveform change indicator (WCI), which reflects a change within one heartbeat; modified RR interval ratio (modRRIR), which characterizes the successive heartbeat interval variation. The overall classification result is obtained from combining the results separately adopting WCI and modRRIR. The proposed algorithm is validated using the public ECG database with a result outperforming others in the literature, as well as using the data collected from the ECG platform HeartCarer built in our research group.
Considering the multi-class classification in the cloud server, a patient-specific single-lead ECG heartbeat classification strategy is proposed to discriminate ventricular ectopic beats (VEBs) and Supraventricular Ectopic Beats (SVEBs). Two types of features are extracted: Intra-beat features characterize the distortion of the waveform within one heartbeat, while inter-beat features reflect the variation between successive heartbeats. A novel fusion strategy consisting of a global classifier and a local classifier is presented. The local classifier is obtained using the high-confidence heartbeats extracted from the first 5-minute data of a specific patient, while the global classifier is trained by the public training data. The advantage of the developed strategy is that fully automatic classification is realized without the intervention of physicians. Finally, simulation results show that comparable or even better classification performance is achieved, which validates the effectiveness of the proposed strategy. / Graduate / 2019-03-19
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Computer tools for designing self-sufficient military base campsPutnam, Nathan Hassan 19 November 2012 (has links)
Military Forward Operating Base Camps (FOBs) support and enable sustained military operations abroad by providing safe locations for soldiers and supporting contractors to eat, sleep, and maintain personal hygiene. FOBs need some amount of energy and water to provide these services but are often located in austere environments that do not have access to grid utilities. Off-grid FOBs are not self-sufficient; they are dependent on supply chains for the services they provide to camp occupants. The challenge of supplying FOBs with fuel and water and removing waste (resource resupply and waste removal comprise logistical requirements) is associated with very high human, monetary, strategic, and environmental costs. There are many research efforts across the U.S. Department of Defense (DoD) that seek to reduce FOB logistical requirements, but it is currently very difficult to identify the research efforts that are most beneficial to DoD goals. There are also many factors that make designing FOBs to be more self-sufficient challenging including varying missions, environments, and legacy equipment at currently-fielded FOBs, a lack of baseline data on FOB logistical requirements, an unclear relationship between design changes and resource use behavior, and an unclear valuation of saved resources. This research seeks to develop computer tools and contribute to a methodology that can be used to design FOBs that are more self-sufficient. More self-sufficient FOBs provide high quality services to occupants but do so with mitigated logistical requirements. To this end, a detailed computer model of specific type of FOB (a single 150-person Force Provider module) is developed, and baseline levels of resource requirements are established. Potentially resource-saving devices and other design changes are incorporated into the FOB model and simulated to assess each design change's effect on resource use and waste production. Then, estimated resource savings are weighed against required investment for each design change to arrive at design recommendations. The results of this research effort are specific design recommendations for making the Force Provider system more self-sufficient, as well as computer tools and a methodology that are applicable to other off-grid habitation redesign problems. / text
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Development of a flexible turntable for storage of subsea cable : A Systems Engineering approachIsac, Andersson January 2022 (has links)
Infrastructure for electricity and telecommunication, such as subsea cables, are critical in modern society. Future estimates also indicate an increased demand. Subsea cables enable the use of offshore wind power farms, transnational energy distribution and global data transfer. It is therefore considered important for a continuous development toward a sustainable future. Consistently, long and seamless cables, with complex inner structure, are requested. This makes the manufacturing and recurrent storing process challenging. Present cable storage systems, namely carousels, are a vital part of the manufacturing. In this case study, a present manufacturing system of subsea cables was presented, whereby a possible improvement for a more flexible manufacturing process was suggested. The work focused on developing a new turntable, which is a subsystem, within the main system, the carousel. A Systems Engineering approach was used in order to develop the manufacturing system. This development resulted in three conceptual turntable solutions with improved flexibility and resource efficiency. The solutions generated consist of a turntable with two independently rotatable compartments. Although the focus of this case study was to develop a solution toward the subsea power cable industry, it is possible to up- or downscale depending on the required weight capacity, area and number of compartments.
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Textila material av bananavfall : En undersökning om för- och nackdelar för bananavfall som textiltmaterial i modebranschen. / Textile material of banana waste : A review study in regards to the advantages and disadvantages for banana waste as textile material within the fashion industry.Hamp, Cajsa, Nilsson, Emelie January 2020 (has links)
Denna studie undersöker för- och nackdelar med textilier gjorda av bananavfall applicerat inom modebranschen. Studien granskas ur ett miljöperspektiv med ett fokus utifrån mål 12: Hållbarkonsumtion och produktion från de Globala målen. De Globala målen är en del avhandlingsplanen Agenda 2030 som är uppsatt av United Nation Development Program, där det eftersträvas att fram till och med år 2030 ha uppnått en mer hållbar värld. Vidare kommer bananfiberns egenskaper att granskas ur ett teoretiskt perspektiv för att se om detta är ett lämpligt val inom modebranschen. Studien ger också en inblick i hur modebranschen i Sverige förhåller sig till textilt material av bananavfall. Studien utgör en viktig del för att sprida kunskap om bananfiberns för- och nackdelar medmöjligheter att ge bättre förutsättningar till modeindustrin att kunna använda en hållbar fiber. Studiens resultat visar att det finns möjligheter för att detta ska kunna uppnås i framtiden sett ur ett hållbarhetsperspektiv, samt utifrån bananfiberns egenskaper. / This thesis examines the advantages and disadvantages regarding textiles made out of bananawaste within the fashion industry. An environmental perspective is applied based on goal 12:Responsible consumption and production from the Sustainable Development Goals (SDGs).SDGs is a part of the 2030 Agenda set by United Nation Development Programs, which aims tocreate a better world by 2030. Furthermore, the characteristics of the banana fiber and itsadequacy for the fashion industry will be theoretically examined. An aspect regarding thematerial from the fashion industries point of view will also be processed. Only swedishcompanies are included in the thesis.The thesis constitutes an important part for disseminate knowledge regarding the advantages anddisadvantages of the banana fiber. This with an expectation to provide better conditions withinthe fashion industry using a more sustainable fiber. Based on the results of the thesis, theopportunities to achieve this in the future are significant, due to the fact that both an sustainableperspective and the characteristics of the banana fiber shows a positive outcome. Furthermore,the thesis indicates a split result regarding the fashion companies point of view in the matter.
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