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Статті в журналах з теми "Overall energy efficiency":
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Water, Thames, Simon Whatley, and Angus Berry. "Overall energy efficiency practices." World Pumps 2008, no. 500 (May 2008): 56–58. http://dx.doi.org/10.1016/s0262-1762(08)70154-8.
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Schäfer, Winfried. "Energy crops and renewable energy: overall and process efficiency." Suomen Maataloustieteellisen Seuran Tiedote, no. 23 (January 31, 2008): 1–6. http://dx.doi.org/10.33354/smst.75866.
Анотація:
Introduction and Objectives The crop scientist focuses his research on high quantity and quality of yield based on a sustainable tilth. The engineer is interested in maximisation of the process efficiency. He interprets the crop scientist’s ap-proach as maximisation of photosynthesis efficiency. Objective of this paper is to support the assessment of energy crop production applying engineering sciences methods in energy accounting. Methods and results The sustainability of energy crop production is assessed by calculating the overall efficiency using rape as example. The results show that the high process energy efficiency of the rapeseed cultivation fosters com-mon acceptance of rape as energy crop. Even under Finnish climate conditions, exergy of rape crop ex-ceeds up to 11-times the energy input for production and exergy of seed up to 3.7 times. Conversion of rapeseed into fuel decreases the energy surplus. Rape methyl ester (RME) delivers still 1.2-fold the energy input for cultivation and conversion. The whole rape crop (root, straw, seed) contains 3 to 6 ‰ of the overall energy input, RME 1 to 2 ‰ only. Animal production converts rape meal feed into manure, which is suitable for anaerobic digestion together with glycerine. The biogas augments the overall efficiency additionally 0.2 to 0.5 ‰. Rape cultivation requires a 4 to 7-year crop rotation. This and the low overall efficiency make it difficult in Finland to achieve energy self-sufficiency replacing diesel fuel by RME. The technical efficiency of the photosynthesis limits the maximum energy yield and reaches up to 0.8 % in Finland. By comparison, the efficiency of a photovoltaic collector is 165 to 248-fold better than the con-version efficiency of biomass or biogas produced from rapeseed and rape straw into electric power. The efficiency of the thermal collector exceeds heat production from burning the rape crop 157 to 443-fold. However, storage and continuous production of power and heat from sun energy is very limited. For that reason, the storage of sun energy in liquid carbon hydrates is subject of present research. Conclusion Energy crop production is captivating with many win-win situations: environmentally neutral bio-fuels replace polluting fossil fuels, farmers get better prices for energy crops, the agrochemical industry gains from intensification of energy crop production, and turn over of power industry grows due to increasing energy consumption to produce agrochemicals and to process biomass into fuel. As a following, the state tax income improves too. However, better prices for mainstream energy crops may trigger export of envi-ronmental pollution at the expense of food production because higher overall efficiency in tropical coun-tries favours the import of organic raw material for bio fuel production. Yet, high process efficiencies of technical processes to convert biomass into fuel justify the production of renewable energy from organic waste and residues. Thus, agriculture should not focus on energy crop production but produce high quality food environment-friendly. The overall efficiency of energy production from energy crops will never be competitive with solar techniques. Solar collectors replace fossil fuels for heat production outside agricul-ture already now sustainable and more efficient. Research on solar-technical processes to produce liquid carbon hydrates from methane, carbon dioxide, and water powered by solar energy without diversion into photosynthesis offers much a greater potential than research on energy crop production. As a measure for sustainability of renewable energy production, the energy surplus from sun energy conversion per capita and square meter is proposed.
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Шастун, Світлана Вікторівна. "Overall assessment of the energy efficiency in Ukraine." Technology audit and production reserves 6, no. 5(32) (November 24, 2016): 36–41. http://dx.doi.org/10.15587/2312-8372.2016.87541.
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Radosavljevic, Dusan, Aleksandar Manojlovic, Olivera Medar, and Nebojsa Bojovic. "Vehicle fleet energy efficiency: Influence on overall vehicle effectiveness." Thermal Science 22, no. 3 (2018): 1537–48. http://dx.doi.org/10.2298/tsci170926074r.
Анотація:
This paper presents the research on vehicle fleet energy efficiency impact upon overall vehicle effectiveness. Transport companies and companies with own vehicle fleets tend to enhance their resource effectiveness, and to increase their transport service quality with the objective of attaining a competitive position on the market. Since energy consumed for transport operations is an important transport process resource, a method for assessing transport process effectiveness has been developed with the objective of increasing vehicle fleet effectiveness and its energy efficiency, and the overall vehicle effectiveness human indicator has been defined accordingly. The developed method was then implemented in an actual vehicle fleet and variations of the overall vehicle effectiveness human indicator were researched, as well as specific energy consumptions for respective net transport volumes depending on the following indicators: vehicle payload capacity utilization rate and mileage utilization rate. It is shown that specific energy consumption influences overall vehicle effectiveness depending on both the payload capacity utilization rate and mileage utilization rate.
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Wang, Hui, Xiu Ji, Liao Xu, Hong Zhang, and Yinping An. "Analysis on overall energy efficiency and flexibility of thermal integrated energy system." Thermal Science 27, no. 2 Part A (2023): 975–81. http://dx.doi.org/10.2298/tsci2302975w.
Анотація:
In order to solve the problem of energy consumption, improve the efficiency of energy utilization and develop new energy, the total energy consumption and fluctuation of thermal integrated energy were analyzed. Four suggestions are put forward for the integrated power system of flexible thermal power plant, namely, electric heat storage system, electric heat pump heat storage system, g, heating system and high pressure heating system via steam turbine, which can improve the air energy consumption capacity of the system and reduce the total coal consumption of the system. Among them, in the case of small air conditioning units or small air conditioning units do not use electric heating furnace and electric heat pump furnace. Heat storage technology of thermal power unit is not suitable for daily exhaust. In contrast, the high pressure/IP bypass heating process of steam turbine is more flexible and less restrictive, which is the best method for comparison. Compared with other schemes discussed by the author, this scheme has the highest flexibility and the least restrictions, and is the best one among the four.
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Haglid, Klas C. "Two Approaches to Using Energy Recovery to Improve Overall System Energy Efficiency Rating." Energy Engineering 106, no. 4 (July 2009): 7–28. http://dx.doi.org/10.1080/01998590909509184.
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Et.al, Raghunandan G. H. "Energy-Efficient Hybrid Hierarchical Routing scheme for overall Efficiency in WSN." Turkish Journal of Computer and Mathematics Education (TURCOMAT) 12, no. 3 (April 11, 2021): 3581–88. http://dx.doi.org/10.17762/turcomat.v12i3.1635.
Анотація:
Wireless Sensor Network are spatially distributed sensors intended to monitor different physiological conditions. Sensing and communicating data from one place to another consumes more energy, therefore the management of sensor energy is a very important factor. Energy utilization, synchronization, and a lifetime of the network are the main criteria in WSN. More energy is utilized by sensors that are distant from the base station. The gateway nodes are deployed to collect and relay information from nodes to the base station to resolve this problem. To decrease energy consumption, gateway nodes are deployed in the network. In this paper, a hybrid approach is used to increase the overall efficiency of the network in WSNs with time synchronization which increases the throughput of the network. The efficiency of proposed protocol based network has shown improvements in network lifetime, residual energy, data packets, and the throughput of the network. The performance of WSN of the proposed scheme is compared to other classical routing schemes and the proposed algorithm has proved its merit.
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Vouros, Alexandros, Emmanouil Mathioulakis, Elias Papanicolaou, and Vassilis Belessiotis. "Modelling the overall efficiency of parabolic trough collectors." Sustainable Energy Technologies and Assessments 40 (August 2020): 100756. http://dx.doi.org/10.1016/j.seta.2020.100756.
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Alhaisoni, Majed. "IoT Energy Efficiency through Centrality Metrics." Annals of Emerging Technologies in Computing 3, no. 2 (April 1, 2019): 14–21. http://dx.doi.org/10.33166/aetic.2019.02.002.
Анотація:
The Internet of Things is the current and next revolution in integrating various technologies and wireless communications. It has been shown to make an important contribution in various modes of communication, in homes, offices and other buildings. However, certain research issues are still remain, such as life span of the network and a definition of the most influential nodes in communications, which affect the overall energy distribution. This paper introduces a new approach to enhance the communication over the internet of things, by combining two different domains, the computer network and network science. Various scenarios have been thoroughly implemented and tested over different network topologies. The results show clear enhancements on network centrality and overall energy distribution.
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Nadimi, Reza, and Koji Tokimatsu. "Potential energy saving via overall efficiency relying on quality of life." Applied Energy 233-234 (January 2019): 283–99. http://dx.doi.org/10.1016/j.apenergy.2018.10.039.
Дисертації з теми "Overall energy efficiency":
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Zheng, Zhanghua. "Overall CO2 efficiency assessment for a low carbon energy system." Thesis, University of Bath, 2014. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.619233.
Анотація:
Decarbonization of the power sector is of great importance for the transition to a sustainable and low-carbon world economy. Estimating carbon efficiency in the power sector is a key step to grasp the impact of demand-side usage changes and evaluate their potential environmental benefits. In order to quantify the environmental benefits of demand-side usage changes, Average Emission Factor (AEF) and Marginal Emission Factor (MEF) have been proposed in the electrical power sector. AEF is defined as the ratio of the total CO2 emitted in the system to the total electricity generated. It is an effective factor for reporting on CO2 emissions at system level and on an average basis, but the current AEF model lacks clarity on the factors actually affecting the estimation. MEF is defined as the incremental change in carbon emissions as a result of a change in demand. However, previous MEF assessments did not consider key technical limitations, such as ramp-rate constraint for generators and network constraints, and carbon trading mechanisms. This thesis improves the estimation for both AEF and MEF and key achievements can be summarized as: 1). A novel model of estimating AEF, with its application to GB, US and China’s electricity system. 2). Improvement on conventional MEF model by considering ramp-rate constraint in dispatch order. 3). Sensitivity studies on MEF using current fuel prices and future fuel prices. 4). A new model of estimating MEF considering both the utilization level of generators and the carbon costs when determining the dispatch order. 5). The effect of power network on MEF estimation, with a comparison of congested scenarios and non-congested scenario.
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Kumari, Epa. "Analysis of Building Envelops to Optimize Energy Efficiency as per Code of Practice for Energy Efficient Buildings in Sri Lanka - 2008." Thesis, KTH, Tillämpad termodynamik och kylteknik, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-117984.
Анотація:
Residential and commercial buildings consume approximately 20% of the global energy generation. This value is continuously growing and the governments across the globe have realized the importance of regulating the building construction to optimize the energy utilization. Energy efficient building codes have been developed to optimize the energy efficiency in buildings. OTTV (Overall Thermal Transfer Value) is a key parameter for evaluating energy efficiency of building envelops in the present building code of Sri Lanka. In this research, the prescriptive requirements mentioned in the building code for the building envelops to optimize the energy efficiency of five (05) commercial buildings has been analyzed. The indoor climate was modeled and the annual cooling energy variation with Overall Thermal Transfer Value was studied using “DesignBuilder” software. A cost benefit analysis was carried out for enhanced energy efficiency building envelops applications. It was attempted to develop a general relationship between the OTTV and annual cooling energy requirement for each building. It has been observed that a second order polynomial relationship with R2 of 0.861 exists for RDA building, linear relationship with R2 of 0.838 exists for AirMech building. However a specific relationship could not be observed for BMICH, SLSI and WTC buildings. The impact on cooling energy requirement from envelop parameter modification is unique for each building. In some instances the reduction of OTTV has not resulted in any reduction of the cooling energy requirement. There is a combined effect from each building component which affects the final cooling energy requirement. A simulation based technique to be used to find the optimum building envelops design.
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Khazaii, Javad. "Effects of sub-optimal component performance on overall cooling system energy consumption and efficiency." Diss., Georgia Institute of Technology, 2012. http://hdl.handle.net/1853/43707.
Анотація:
Predicted cooling system performance plays an important role in choices among alternative system selections and designs. When system performance is expressed in proper indicators such as "overall system energy consumption" or "overall system efficiency", it can provide the decision makers with a quantitative measure of the extent to which a cooling system satisfies the system design requirements and objectives. Predictions of cooling system energy consumption and efficiency imply assumptions about component performance. Quantitative appraisal of the uncertainty (lack of knowledge) in these assumptions can be used by design practitioners to select and design systems, by energy contractors to guarantee future system energy cost savings, and codes and standards officials to set proper goals to conserve energy.
Our lack of knowledge has different sources, notably unknown tolerances in equipment nameplate data, and unpredictable load profiles. Both cause systems to under-perform current predictions, and as a result decrease the accuracy of the outcomes of energy simulations that commonly are used to verify system performance during the design and construction stages. There can be many other causes of unpredictable system behavior, for example due to bad workmanship in the installation, occurrence of faults in the operation of certain system parts, deterioration over time and other. These uncertainties are typically much harder to quantify and their propagation into the calculated energy consumption is much harder to accomplish. In this thesis, these categories of failures are not considered, i.e. the treatment is limited to component tolerances and load variability.
In this research the effects of equipment nameplate tolerances and cooling load profile variability on the overall energy consumption and efficiency of commonly used commercial cooling systems are quantified. The main target of this thesis is to present a methodology for calculating the chances that a specific cooling system could deviate from a certain efficiency level by a certain margin, and use these results to guide practitioners and energy performance contractors to select, and guarantee system performances more realistically. By doing that, the plan is to establish a systematic approach of developing expressions of risk, in commercial cooling system consumption and efficiency calculations, and thus to advocate the use of expressions of risk as design targets.
This thesis makes a contribution to improving our fundamental understanding of performance risk in selecting and sizing certain HVAC design concepts.
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Negumbo, Rosalia. "Analysis for electrical energy and overall efficiency in distribution networks with harmonic distortion." Thesis, Cape Peninsula University of Technology, 2009. http://hdl.handle.net/20.500.11838/1103.
Анотація:
Thesis (MTech (Electrical Engineering))--Cape Peninsula University of Technology, 2009Traditionally, harmonics are ignored in overall efficiency and energy usage studies. However, in the modern era, power systems contain levels of harmonics which can no longer be ignored by engineers, planners, energy conservationists and economists. The directions of power flows have to be considered when harmonics are present in the power network. A methodology and new formulae for individual and overall efficiency and energy usage is developed at each frequency (f1, h and H) and forms the main contribution to research in this field. Two case studies were conducted; a measurement based laboratory experiment set-up and a simulated case study. In the set-up, measurements of current, voltage and power at different points in the network for the 1st, 5th and 7th frequencies were taken. Current and voltage results were used for hand calculations to prove the measured power flows and directions. The measurements were taken with a Fluke 345 three-phase harmonic power quality analyzer. For the simulated case study, a network was investigated using the DIgSILENT and SuperHarm software packages. Their results were compared and it was found that DIgSILENT is the preferred package for power results. It was found that the total harmonic distortion limit for voltage in the simulated network exceeded an acceptable level. The harmonic mitigation solution chosen was to design a passive filter to decrease the distortion by shifting the resonance point of the network. The method to design the passive filter and its impact on efficiency and energy usage is included in the thesis. Unique power flow direction diagrams are developed as part of the methodology and form an essential step in the derivation of the new formulae. Efficiencies, power losses and energy usage at individual and combined frequencies were determined. Results showed the negative effects of harmonics on overall efficiency, energy usage and power losses of the system. The methodology and new formulae developed was found to be effective and their application is recommended for use by industry.
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Mitrokhin, Alexey. "Energy saving in the process of gas pipeline overhaul." Thesis, KTH, Kraft- och värmeteknologi, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-149322.
Анотація:
The problem of energy saving during overhaul of a linear part of gas trunkline is regarded in this paper. This issue has been analyzed from different perspectives. Thermodynamic analysis of gas evacuation from a string that is off operation for the overhaul to a parallel or adjacent string with the use of mobile compressor systems was made. Economical attractiveness of mobile compressor systems applications was proved. Various methods of gas trunklines linear parts overhaul have been considered. For each of the methods problems of minimization of necessary for the overhaul amount of energy consuming machines have been solved. The results can be used in the development of overhaul projects of the gas trunklines linear parts.
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Lv, Jing. "Resource Allocation in Underlay and Overlay Spectrum Sharing." Doctoral thesis, Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2015. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-159087.
Анотація:
As the wireless communication technologies evolve and the demand of wireless services increases, spectrum scarcity becomes a bottleneck that limits the introduction of new technologies and services. Spectrum sharing between primary and secondary users has been brought up to improve spectrum efficiency. In underlay spectrum sharing, the secondary user transmits simultaneously with the primary user, under the constraint that the interference induced at the primary receiver is below a certain threshold, or a certain primary rate requirement has to be satisfied. Specifically, in this thesis, the coexistence of a multiple-input single-output (MISO) primary link and a MISO/multiple-input multiple-output (MIMO) secondary link is studied. The primary transmitter employs maximum ratio transmission (MRT), and single-user decoding is deployed at the primary receiver. Three scenarios are investigated, in terms of the interference from the primary transmitter to the secondary receiver, namely, weak interference, strong interference and very strong interference, or equivalently three ranges of primary rate requirement. Rate splitting and successive decoding are deployed at the secondary transmitter and receiver, respectively, when it is feasible, and otherwise single-user decoding is deployed at the secondary receiver. For each scenario, optimal beamforming/precoding and power allocation at the secondary transmitter is derived, to maximize the achievable secondary rate while satisfying the primary rate requirement and the secondary power constraint. Numerical results show that rate splitting at the secondary transmitter and successive decoding at the secondary receiver does significantly increase the achievable secondary rate if feasible, compared with single-user decoding at the secondary receiver. In overlay spectrum sharing, different from underlay spectrum sharing, the secondary transmitter can utilize the knowledge of the primary message, which is acquired non-causally (i.e., known in advance before transmission) or causally (i.e., acquired in the first phase of a two-phase transmission), to help transmit the primary message besides its own message. Specifically, the coexistence of a MISO primary link and a MISO/MIMO secondary link is studied. When the secondary transmitter has non-causal knowledge of the primary message, dirty-paper coding (DPC) can be deployed at the secondary transmitter to precancel the interference (when decoding the secondary message at the secondary receiver), due to the transmission of the primary message from both transmitters. Alternatively, due to the high implementation complexity of DPC, linear precoding can be deployed at the secondary transmitter. In both cases, the primary transmitter employs MRT, and single-user decoding is deployed at the primary receiver; optimal beamforming/precoding and power allocation at the secondary transmitter is obtained, to maximize the achievable secondary rate while satisfying the primary rate requirement and the secondary power constraint. Numerical results show that with non-causal knowledge of the primary message and the deployment of DPC at the secondary transmitter, overlay spectrum sharing can achieve a significantly higher secondary rate than underlay spectrum sharing, while rate loss occurs with the deployment of linear precoding instead of DPC at the secondary transmitter. When the secondary transmitter does not have non-causal knowledge of the primary message, and still wants to help with the primary transmission in return for the access to the spectrum, it can relay the primary message in an amplify-and-forward (AF) or a decode-and-forward (DF) way in a two-phase transmission, while transmitting its own message. The primary link adapts its transmission strategy and cooperates with the secondary link to fulfill its rate requirement. To maximize the achievable secondary rate while satisfying the primary rate requirement and the primary and secondary power constraints, in the case of AF cooperative spectrum sharing, optimal relaying matrix and beamforming vector at the secondary transmitter is obtained; in the case of DF cooperative spectrum sharing, a set of parameters are optimized, including time duration of the two phases, primary transmission strategies in the two phases and secondary transmission strategy in the second phase. Numerical results show that with the cooperation from the secondary link, the primary link can avoid outage effectively, especially when the number of antennas at the secondary transceiver is large, while the secondary link can achieve a significant rate. Power is another precious resource besides spectrum. Instead of spectrum efficiency, energy-efficient spectrum sharing focuses on the energy efficiency (EE) optimization of the secondary transmission. The EE of the secondary transmission is defined as the ratio of the achievable secondary rate and the secondary power consumption, which includes both the transmit power and the circuit power at the secondary transmitter. For simplicity, the circuit power is modeled as a constant. Specifically, the EE of a MIMO secondary link in underlay spectrum sharing is studied. Three transmission strategies are introduced based on the primary rate requirement and the channel conditions. Rate splitting and successive decoding are deployed at the secondary transmitter and receiver, respectively, when it is feasible, and otherwise single-user decoding is deployed at the secondary receiver. For each case, optimal transmit covariance matrices at the secondary transmitter are obtained, to maximize the EE of the secondary transmission while satisfying the primary rate requirement and the secondary power constraint. Based on this, an energy-efficient resource allocation algorithm is proposed. Numerical results show that MIMO underlay spectrum sharing with EE optimization can achieve a significantly higher EE compared with MIMO underlay spectrum sharing with rate optimization, at certain SNRs and with certain circuit power, at the cost of the achievable secondary rate, while saving the transmit power. With rate splitting at the secondary transmitter and successive decoding at the secondary receiver if feasible, a significantly higher EE can be achieved compared with the case when only single-user decoding is deployed at the secondary receiver. Moreover, the EE of a MIMO secondary link in overlay spectrum sharing is studied, where the secondary transmitter has non-causal knowledge of the primary message and employs DPC to obtain an interference-free secondary link. Energy-efficient precoding and power allocation is obtained to maximize the EE of the secondary transmission while satisfying the primary rate requirement and the secondary power constraint. Numerical results show that MIMO overlay spectrum sharing with EE optimization can achieve a significantly higher EE compared with MIMO overlay spectrum sharing with rate optimization, at certain SNRs and with certain circuit power, at the cost of the achievable secondary rate, while saving the transmit power. MIMO overlay spectrum sharing with EE optimization can achieve a higher EE compared with MIMO underlay spectrum sharing with EE optimizationAufgrund der rasanten Entwicklung im Bereich der drahtlosen Kommunikation und der ständig steigenden Nachfrage nach mobilen Anwendungen ist die Knappheit von Frequenzbändern ein entscheidender Engpass, der die Einführung neuer Funktechnologien behindert. Die gemeinsame Benutzung von Frequenzen (Spektrum-Sharing) durch primäre und sekundäre Nutzer ist eine Möglichkeit, die Effizienz bei der Verwendung des Spektrums zu verbessern. Bei der Methode des Underlay-Spektrum-Sharing sendet der sekundäre Nutzer zeitgleich mit dem primären Nutzer unter der Einschränkung, dass für den primären Nutzer die erzeugte Interferenz unterhalb eines Schwellwertes liegt oder gewisse Anforderungen an die Datenrate erfüllt werden. In diesem Zusammenhang wird in der Arbeit insbesondere die Koexistenz von Mehrantennensystemen untersucht. Dabei wird für die primäre Funkverbindung der Fall mit mehreren Sendeantennen und einer Empfangsantenne (MISO) angenommen. Für die sekundäre Funkverbindung werden mehrere Sendeantennen und sowohl eine als auch mehrere Empfangsantennen (MISO/MIMO) betrachtet. Der primäre Sender verwendet Maximum-Ratio-Transmission (MRT) und der primäre Empfänger Einzelnutzerdecodierung. Für den sekundären Nutzer werden außerdem am Sender eine Datenratenaufteilung (rate splitting) und am Empfänger entweder eine sukzessive Decodierung – sofern sinnvoll – oder andernfalls eine Einzelnutzerdecodierung verwendet. Im Unterschied zur Methode des Underlay-Spektrum-Sharing kann der sekundäre Nutzer beim Verfahren des Overlay-Spektrum-Sharing die Kenntnis über die Nachrichten des primären Nutzers einsetzen, um die Übertragung sowohl der eigenen als auch der primären Nachrichten zu unterstützen. Das Wissen über die Nachrichten erhält er entweder nicht-kausal, d.h. vor der Übertragung, oder kausal, d.h. während der ersten Phase einer zweistufigen Übertragung. In der Arbeit wird speziell die Koexistenz von primären MISO-Funkverbindungen und sekundären MISO/MIMO-Funkverbindungen untersucht. Bei nicht-kausaler Kenntnis über die primären Nachrichten kann der sekundäre Sender beispielsweise das Verfahren der Dirty-Paper-Codierung (DPC) verwenden, welches es ermöglicht, die Interferenz durch die primären Nachrichten bei der Decodierung der sekundären Nachrichten am sekundären Empfänger aufzuheben. Da die Implementierung der DPC mit einer hohen Komplexität verbunden ist, kommt als Alternative auch eine lineare Vorcodierung zum Einsatz. In beiden Fällen verwendet der primäre Transmitter MRT und der primäre Empfänger Einzelnutzerdecodierung. Besitzt der sekundäre Nutzer keine nicht-kausale Kenntnis über die primären Nachrichten, so kann er als Gegenleistung für die Mitbenutzung des Spektrums dennoch die Übertragung der primären Nachrichten unterstützen. Hierfür leitet er die primären Nachrichten mit Hilfe der Amplify-And-Forward-Methode oder der Decode-And-Forward-Methode in einer zweitstufigen Übertragung weiter, währenddessen er seine eigenen Nachrichten sendet. Der primäre Nutzer passt seine Sendestrategie entsprechend an und kooperiert mit dem sekundären Nutzer, um die Anforderungen an die Datenrate zu erfüllen. Nicht nur das Spektrum sondern auch die Sendeleistung ist eine wichtige Ressource. Daher wird zusätzlich zur Effizienz bei der Verwendung des Spektrums auch die Energieeffizienz (EE) einer sekundären MIMO-Funkverbindung für das Underlay-Spektrum-Sharing-Verfahren analysiert. Wie zuvor wird für den sekundären Nutzer am Sender eine Datenratenaufteilung (rate splitting) und am Empfänger entweder eine sukzessive Decodierung oder eine Einzelnutzerdecodierung betrachtet. Weiterhin wird die EE einer sekundären MIMO-Funkverbindung für das Overlay-Spektrum-Sharing-Verfahren untersucht. Dabei nutzt der sekundäre Nutzer die nicht-kausale Kenntnis über die primären Nachrichten aus, um mittels DPC eine interferenzfreie sekundäre Funkverbindung zu erhalten
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Sánchez, González Luis. "Contribution to the cross-layer optimization of intra-cluster communication mechanisms in personal networks (Contribución a la optimización intercapa de los mecanismos de comunicación intra-cluster en redes personales)." Doctoral thesis, Universidad de Cantabria, 2009. http://hdl.handle.net/10803/10672.
Анотація:
En el futuro, los dispositivos digitales formarán parte del entorno en el que las personas se desenvuelvan, participarán en nuestros objetivos y necesidades y nos ayudarán a "hacer más haciendo menos". A través de los dispositivos portátiles o aquellos que estén embebidos a nuestro alrededor el usuario será capaz de interactuar con el futuro universo de servicios e infraestructuras ubicuas. El principal paradigma que se seguirá se basa en que este universo estará centrado en el usuario ya que éste demandará los servicios que más le convengan en cualquier momento y lugar, todo ello preservando nuestra privacidad y seguridad. Este nuevo concepto no sólo se aplica a un entorno de ocio sino que en el campo profesional las redes inalámbricas de próxima generación permitirán incrementar nuestra productividad, reduciendo el peso de tareas repetitivas, poniendo a nuestra disposición la información relevante en el momento adecuado y según sean las necesidades particulares del usuario en ese momento y permitiéndonos trabajar con otras personas independientemente de donde se encuentren. En particular, se intuye que las redes de próxima generación se diseñen de forma que aglutinen todos los servicios disponibles a través de los diferentes sistemas que existan de forma que las posibles deficiencias de alguno de ellos se vean compensadas por otro. Lo que se pretende conseguir es que el usuario pueda disfrutar en todo momento y lugar de los servicios que desee sin que ello suponga un esfuerzo.Este concepto implica diferentes retos tecnológicos y la integración de múltiples sistemas. Dentro de estos retos tecnológicos esta Tesis aborda los siguientes: soporte de la heterogeneidad en lo referente a las tecnologías de acceso radio que existen y que eventualmente aparecerán en el futuro y que coexistirán en un mismo terminal; desarrollo de técnicas de optimización basadas en la cooperación entre diferentes capas de la pila de protocolos; implementación de estrategias de selección de la red que mejor pueda soportar un determinado servicio ante la posibilidad de utilización de múltiples tecnologías de acceso; optimización del uso de recursos energéticos en las comunicaciones dentro de la red; protección de la privacidad y la seguridad de las comunicaciones personales del usuario.Desde el punto de vista de las aportaciones, en esta Tesis se ha contribuido mediante el diseño, implementación y validación de una serie de técnicas de optimización de las comunicaciones en redes de dispositivos móviles basadas en información intercapa. Para ello, se propone una arquitectura de protocolos novedosa que permite soportar la heterogeneidad en términos de tecnologías de acceso dentro del mismo terminal. El concepto de aislar las capas superiores de la pila de protocolos de las tecnologías de acceso subyacentes se consigue a través de una Capa de Convergencia Universal (UCL, en sus siglas en inglés). El diseño y la especificación esta arquitectura así como de los bloques funcionales que la componen son la primera contribución que se hace en esta Tesis. La UCL supone el marco en el que el resto de técnicas de optimización que se presentan han sido desarrolladas.Igualmente, se desarrollan una serie de técnicas basadas en optimización intercapa que permiten una gestión eficiente de los recursos disponibles así como una mejora en el uso de la energía. Finalmente, se implementan los mecanismos de autenticación y encriptación que permiten asegurar las comunicaciones dentro de la red. El diseño, implementación y validación de estos mecanismos supone la segunda contribución en esta Tesis. El empleo de técnicas de optimización basadas en información procedentes de diferentes capas de la pila de protocolos es la base de los dos mecanismos que se han propuesto. El primero de ellos se basa en la selección dinámica de la tecnología de acceso a utilizar para obtener un rendimiento óptimo del sistema. La segunda estrategia de optimización consiste en el uso simultáneo de varias tecnologías de acceso para conseguir una mejora en las prestaciones de la red. Aparte de la optimización en cuanto al rendimiento en términos de ancho de banda y calidad de servicio, se ha evaluado la mejora de la eficiencia energética conseguida gracias a las soluciones propuestas. Los resultados obtenidos permiten concluir que las propuestas realizadas en el marco de esta Tesis representan una optimización tanto en parámetros de calidad de servicio como en la eficiencia energética del sistema.El mayor avance respecto del estado del arte se centra en habilitar al usuario para que utilice de manera transparente, eficiente y segura los dispositivos que tiene a su alrededor independientemente de la heterogeneidad que presenten y sin requerir de un conocimiento intensivo de la tecnología. El usuario podrá comunicarse haciendo un uso óptimo de los recursos a su alcance sin preocuparse de tener que gestionarlos él mismo.In the future, computation will be human-centred: it will enter the human world, handling our goals and needs and helping us to do more by doing less. Next generation wireless systems should provide the user access with a broad range of services in a transparent way, independently of user location, by making the technology invisible and embedded in the natural surroundings. New systems will boost our productivity. They will help us automate repetitive human tasks, control a wide range of physical devices in our environment, find the information we need (when we need it, without obliging us to examine thousands of search-engine hits), and enable us to work together with other people through space and time.The achievement of this paradigm led to the identification of a set of optimizations in intra-cluster communications that were needed to fully support it. Firstly, heterogeneity will be a fundamental characteristic of next generation wireless communications since more and more personal devices are equipped with multiple network access technologies so that the user can have access to the different services that the different operational environments provide. However, Next Generation Networks (NGN) will comprise such a diverse number of possibilities that the users cannot be expected to take technical decisions on their own. It is necessary to provide mechanisms that intelligently select the optimal available access network based on context information such as user preferences, power consumption, link quality, etc. Finally, users need to trust the system that supports their personal communications. Within a personal network the most confidential information might be exchanged and the user need to be sure that this will never be disclosed. If the system fails in these features, NGN in general and PNs in particular will never happen.This Thesis has contributed with the development of the mechanisms that tackle the abovementioned challenges. The design and specification of a convergence framework, the so-called Universal Convergence Layer (UCL), has been the first topic addressed. This framework aims to manage all the network access interfaces with which a device is equipped so that they can be transparently used by upper layers as if the node were equipped with a single access technology. On the other hand, the UCL enables the cross-layer optimization paradigm. Its privileged location within the protocol stack gives the UCL the possibility to support both bottom-up and top-down information flow. In this sense, two different solutions based on cross-layer optimization have been proposed to enhance the performance and energy efficiency of the system. The first one deals with the selection at run-time of the most appropriate wireless interface to be used in order to improve the system performance. The second one leverages the striping concept in order to exploit all the network interfaces available. Finally, the UCL also plays a key role in security issues as an enabler for providing link-layer security mechanisms that ensure data confidentiality and integrity, authenticity and non-repudiation. The techniques implemented for node authentication combined with traffic encryption in ad-hoc networks have been thoroughly assessed and have demonstrated their appropriateness.The biggest advance in the state-of-the-art comes from enabling the user to have easy, affordable and seamless control of their devices over heterogeneous communications networks. They are empowered to communicate efficiently and securely with their selected interaction groups, no matter what kind of access is available for them to use.
8
Nkomo, Lihle Immaculate. "Overall vehicle stability for a non-linear multi-varied suspension aimed at disturbance attenuation, energy efficiency and robustness." Thesis, 2020. https://hdl.handle.net/10539/31105.
Анотація:
A dissertation submitted to the Faculty of Engineering and the Built Environment, University of the Witwatersrand, Johannesburg, in fulfilment of the requirements for the degree of Master of Science in Engineering, 2020This dissertation presents the design and implementation of a half-car active suspension system with a pre-disturbance detection algorithm that aims at reducing driver experienced vibrations. The first research contribution is slack-based state constrained optimal control which is used to address the limitations of the penalty function methodology. The performance index is designed so that it optimises for the control actuation energy and the driver’s ride comfort. The optimal control results demonstrate displacement attenuation of 97.5 % and acceleration of up to 80 %, which is practically feasible if high performance sensors and actuators are utilised to enable a fast and efficient response of the active suspension system. The second research contribution is derived from extending the slack variable state constrained optimal control to the linearised half-car suspension system by addressing the limitations of input output feedback linearisation as the state transformation often results in hidden state dynamics. The results from the completely linearised controller show a displacement attenuation of up to 81.82 %. The third research contribution is through the application of an adaptive sliding backstepping controller to the con-structed test-rig, that ensures robust control on non-smooth road surfaces consisting of white noise. The results from the adaptive sliding backstepping demonstrate improved attenuated displacement and smoother accelerations of up to 71.3 % and 60 % respectively. Although the adaptive sliding backstepping trade-offs disturbance attenuation performance, it demonstrates adaptive properties when tested on rough road surfaces. To achieve overall vehicle stability, the use of these controllers can be integrated to benefit from the targeted performances such as robustness
CK2021
9
Lv, Jing. "Resource Allocation in Underlay and Overlay Spectrum Sharing." Doctoral thesis, 2014. https://tud.qucosa.de/id/qucosa%3A27444.
Анотація:
As the wireless communication technologies evolve and the demand of wireless services increases, spectrum scarcity becomes a bottleneck that limits the introduction of new technologies and services. Spectrum sharing between primary and secondary users has been brought up to improve spectrum efficiency.
In underlay spectrum sharing, the secondary user transmits simultaneously with the primary user, under the constraint that the interference induced at the primary receiver is below a certain threshold, or a certain primary rate requirement has to be satisfied. Specifically, in this thesis, the coexistence of a multiple-input single-output (MISO) primary link and a MISO/multiple-input multiple-output (MIMO) secondary link is studied. The primary transmitter employs maximum ratio transmission (MRT), and single-user decoding is deployed at the primary receiver. Three scenarios are investigated, in terms of the interference from the primary transmitter to the secondary receiver, namely, weak interference, strong interference and very strong interference, or equivalently three ranges of primary rate requirement. Rate splitting and successive decoding are deployed at the secondary transmitter and receiver, respectively, when it is feasible, and otherwise single-user decoding is deployed at the secondary receiver. For each scenario, optimal beamforming/precoding and power allocation at the secondary transmitter is derived, to maximize the achievable secondary rate while satisfying the primary rate requirement and the secondary power constraint. Numerical results show that rate splitting at the secondary transmitter and successive decoding at the secondary receiver does significantly increase the achievable secondary rate if feasible, compared with single-user decoding at the secondary receiver.
In overlay spectrum sharing, different from underlay spectrum sharing, the secondary transmitter can utilize the knowledge of the primary message, which is acquired non-causally (i.e., known in advance before transmission) or causally (i.e., acquired in the first phase of a two-phase transmission), to help transmit the primary message besides its own message. Specifically, the coexistence of a MISO primary link and a MISO/MIMO secondary link is studied. When the secondary transmitter has non-causal knowledge of the primary message, dirty-paper coding (DPC) can be deployed at the secondary transmitter to precancel the interference (when decoding the secondary message at the secondary receiver), due to the transmission of the primary message from both transmitters. Alternatively, due to the high implementation complexity of DPC, linear precoding can be deployed at the secondary transmitter. In both cases, the primary transmitter employs MRT, and single-user decoding is deployed at the primary receiver; optimal beamforming/precoding and power allocation at the secondary transmitter is obtained, to maximize the achievable secondary rate while satisfying the primary rate requirement and the secondary power constraint. Numerical results show that with non-causal knowledge of the primary message and the deployment of DPC at the secondary transmitter, overlay spectrum sharing can achieve a significantly higher secondary rate than underlay spectrum sharing, while rate loss occurs with the deployment of linear precoding instead of DPC at the secondary transmitter.
When the secondary transmitter does not have non-causal knowledge of the primary message, and still wants to help with the primary transmission in return for the access to the spectrum, it can relay the primary message in an amplify-and-forward (AF) or a decode-and-forward (DF) way in a two-phase transmission, while transmitting its own message. The primary link adapts its transmission strategy and cooperates with the secondary link to fulfill its rate requirement. To maximize the achievable secondary rate while satisfying the primary rate requirement and the primary and secondary power constraints, in the case of AF cooperative spectrum sharing, optimal relaying matrix and beamforming vector at the secondary transmitter is obtained; in the case of DF cooperative spectrum sharing, a set of parameters are optimized, including time duration of the two phases, primary transmission strategies in the two phases and secondary transmission strategy in the second phase. Numerical results show that with the cooperation from the secondary link, the primary link can avoid outage effectively, especially when the number of antennas at the secondary transceiver is large, while the secondary link can achieve a significant rate.
Power is another precious resource besides spectrum. Instead of spectrum efficiency, energy-efficient spectrum sharing focuses on the energy efficiency (EE) optimization of the secondary transmission. The EE of the secondary transmission is defined as the ratio of the achievable secondary rate and the secondary power consumption, which includes both the transmit power and the circuit power at the secondary transmitter. For simplicity, the circuit power is modeled as a constant. Specifically, the EE of a MIMO secondary link in underlay spectrum sharing is studied. Three transmission strategies are introduced based on the primary rate requirement and the channel conditions. Rate splitting and successive decoding are deployed at the secondary transmitter and receiver, respectively, when it is feasible, and otherwise single-user decoding is deployed at the secondary receiver. For each case, optimal transmit covariance matrices at the secondary transmitter are obtained, to maximize the EE of the secondary transmission while satisfying the primary rate requirement and the secondary power constraint. Based on this, an energy-efficient resource allocation algorithm is proposed. Numerical results show that MIMO underlay spectrum sharing with EE optimization can achieve a significantly higher EE compared with MIMO underlay spectrum sharing with rate optimization, at certain SNRs and with certain circuit power, at the cost of the achievable secondary rate, while saving the transmit power. With rate splitting at the secondary transmitter and successive decoding at the secondary receiver if feasible, a significantly higher EE can be achieved compared with the case when only single-user decoding is deployed at the secondary receiver.
Moreover, the EE of a MIMO secondary link in overlay spectrum sharing is studied, where the secondary transmitter has non-causal knowledge of the primary message and employs DPC to obtain an interference-free secondary link. Energy-efficient precoding and power allocation is obtained to maximize the EE of the secondary transmission while satisfying the primary rate requirement and the secondary power constraint. Numerical results show that MIMO overlay spectrum sharing with EE optimization can achieve a significantly higher EE compared with MIMO overlay spectrum sharing with rate optimization, at certain SNRs and with certain circuit power, at the cost of the achievable secondary rate, while saving the transmit power. MIMO overlay spectrum sharing with EE optimization can achieve a higher EE compared with MIMO underlay spectrum sharing with EE optimization.Aufgrund der rasanten Entwicklung im Bereich der drahtlosen Kommunikation und der ständig steigenden Nachfrage nach mobilen Anwendungen ist die Knappheit von Frequenzbändern ein entscheidender Engpass, der die Einführung neuer Funktechnologien behindert. Die gemeinsame Benutzung von Frequenzen (Spektrum-Sharing) durch primäre und sekundäre Nutzer ist eine Möglichkeit, die Effizienz bei der Verwendung des Spektrums zu verbessern. Bei der Methode des Underlay-Spektrum-Sharing sendet der sekundäre Nutzer zeitgleich mit dem primären Nutzer unter der Einschränkung, dass für den primären Nutzer die erzeugte Interferenz unterhalb eines Schwellwertes liegt oder gewisse Anforderungen an die Datenrate erfüllt werden. In diesem Zusammenhang wird in der Arbeit insbesondere die Koexistenz von Mehrantennensystemen untersucht. Dabei wird für die primäre Funkverbindung der Fall mit mehreren Sendeantennen und einer Empfangsantenne (MISO) angenommen. Für die sekundäre Funkverbindung werden mehrere Sendeantennen und sowohl eine als auch mehrere Empfangsantennen (MISO/MIMO) betrachtet. Der primäre Sender verwendet Maximum-Ratio-Transmission (MRT) und der primäre Empfänger Einzelnutzerdecodierung. Für den sekundären Nutzer werden außerdem am Sender eine Datenratenaufteilung (rate splitting) und am Empfänger entweder eine sukzessive Decodierung – sofern sinnvoll – oder andernfalls eine Einzelnutzerdecodierung verwendet. Im Unterschied zur Methode des Underlay-Spektrum-Sharing kann der sekundäre Nutzer beim Verfahren des Overlay-Spektrum-Sharing die Kenntnis über die Nachrichten des primären Nutzers einsetzen, um die Übertragung sowohl der eigenen als auch der primären Nachrichten zu unterstützen. Das Wissen über die Nachrichten erhält er entweder nicht-kausal, d.h. vor der Übertragung, oder kausal, d.h. während der ersten Phase einer zweistufigen Übertragung. In der Arbeit wird speziell die Koexistenz von primären MISO-Funkverbindungen und sekundären MISO/MIMO-Funkverbindungen untersucht. Bei nicht-kausaler Kenntnis über die primären Nachrichten kann der sekundäre Sender beispielsweise das Verfahren der Dirty-Paper-Codierung (DPC) verwenden, welches es ermöglicht, die Interferenz durch die primären Nachrichten bei der Decodierung der sekundären Nachrichten am sekundären Empfänger aufzuheben. Da die Implementierung der DPC mit einer hohen Komplexität verbunden ist, kommt als Alternative auch eine lineare Vorcodierung zum Einsatz. In beiden Fällen verwendet der primäre Transmitter MRT und der primäre Empfänger Einzelnutzerdecodierung. Besitzt der sekundäre Nutzer keine nicht-kausale Kenntnis über die primären Nachrichten, so kann er als Gegenleistung für die Mitbenutzung des Spektrums dennoch die Übertragung der primären Nachrichten unterstützen. Hierfür leitet er die primären Nachrichten mit Hilfe der Amplify-And-Forward-Methode oder der Decode-And-Forward-Methode in einer zweitstufigen Übertragung weiter, währenddessen er seine eigenen Nachrichten sendet. Der primäre Nutzer passt seine Sendestrategie entsprechend an und kooperiert mit dem sekundären Nutzer, um die Anforderungen an die Datenrate zu erfüllen. Nicht nur das Spektrum sondern auch die Sendeleistung ist eine wichtige Ressource. Daher wird zusätzlich zur Effizienz bei der Verwendung des Spektrums auch die Energieeffizienz (EE) einer sekundären MIMO-Funkverbindung für das Underlay-Spektrum-Sharing-Verfahren analysiert. Wie zuvor wird für den sekundären Nutzer am Sender eine Datenratenaufteilung (rate splitting) und am Empfänger entweder eine sukzessive Decodierung oder eine Einzelnutzerdecodierung betrachtet. Weiterhin wird die EE einer sekundären MIMO-Funkverbindung für das Overlay-Spektrum-Sharing-Verfahren untersucht. Dabei nutzt der sekundäre Nutzer die nicht-kausale Kenntnis über die primären Nachrichten aus, um mittels DPC eine interferenzfreie sekundäre Funkverbindung zu erhalten.
10
Hähnel, Markus. "Vermeidung von Interferenzen bei der Konsolidierung von Diensten auf zeitlich geteilten Ressourcen." 2019. https://tud.qucosa.de/id/qucosa%3A34459.
Анотація:
Der steigende Bedarf an Internettraffic, Speicher und Verarbeitung benötigt immer mehr Hardwareressourcen. Zusätzlich überdimensionieren Datenzentrumbetreiber ihre Infrastruktur, um auch bei Bedarfsspitzen hinreichend Leistung zur Verfügung stellen zu können. Das führt zu einer geringen Ressourcenauslastung und damit zu einem erhöhten Energieverbrauch. Durch Konsolidierung der aktiven Dienste auf einer Teilmenge der physischen Server zu Zeiten geringer Auslastung können zum einen nicht benötigte Server ausgeschaltet werden und zum anderen sind die verbleibenden Server besser ausgelastet. Jedoch müssen sich Dienste nach der Konsolidierung die physischen Ressourcen mit anderen Diensten teilen. Durch Wechselwirkungen auf gemeinsam genutzten Ressourcen, sogenannten Interferenzen, verschlechtert sich die Performanz der Dienste.
In dieser Arbeit wird auf Interferenzen eingegangen, die aufgrund des zeitlich variierenden Ressourcenverbrauchs von Diensten entstehen. Am Beispiel von der Rechenzeit einzelner Prozessorkerne wird mit Hilfe des Cutting Stock Problems mit nichtdeterministischen Längen (ND-CSP) der Energieverbrauch durch die Zahl der benötigten Ressourcen um bis zu 64,1% gesenkt. Durch Berücksichtigung der zeitlichen Variation des Ressourcenverbrauchs verbessert sich die Performanz um bis zu 59,6% gegenüber anderen Konsolidierungsstrategien.
Außerdem wird das Konzept des Überlappungskoeffizienten eingeführt. Dieser beschreibt die probabilistische Beziehung zweier parallel laufender Dienste, inwiefern sie gleichzeitig aktiv sind. Sind Dienste nicht gleichzeitig aktiv, können sie ohne zu erwartende Interferenzen konsolidiert werden. Umgekehrt sollte die Konsolidierung gleichzeitig aktiver Dienste vermieden werden. Die Analyse eines Datenzentrums von Google zeigt, dass beide Szenarien einen signifikanten Anteil darstellen. Zur Berücksichtigung des Überlappungskoeffizienten wird das ND-CSP erweitert und näherungsweise gelöst. Hier zeigt sich jedoch weder eine Verbesserung noch eine Verschlechterung der Performanz der Dienste bei gleichem Energieverbrauch. Perspektivisch, bei der exakten Lösung und weiterer Optimierung, können aber damit Dienste eventuell so allokiert werden, dass ihre Interferenzen reduziert oder im Idealfall sogar weitgehend ausgeschlossen werden können.An increasing portion of IP traffic is processed and stored in data centers. However, data center providers tend to over-provision their resources. Therefore, underutilized resources unnecessarily waste energy. Consolidating services allows them to be executed within a subset of the entire data center and to turn off the unnecessary, idling machines. Additionally, the remaining machines are properly utilized and, hence, more energy-efficient. Nevertheless, this has to be balanced against degrading the quality of service due to the shared resources of the physical machines after the consolidation. This thesis focuses on the above mentioned interferences due to fluctuating workloads. These are treated in the framework of the Cutting Stock Problem, where items with non-deterministic length are introduced. This reduces the power consumption by minimizing the necessary, active resources by up to 64.1% for the exemplary CPU time of individual cores. Thanks to the awareness of workload fluctuations, it improves the performance of services by up to 59.6% compared to other allocation schemes. Additionally, the concept of 'overlap coefficients' is introduced, which describes the probabilistic relation between two services which run in parallel. The more often these services are active at the same time the higher the overlap coefficient and vice versa. Services which are not active at the same time can be consolidated without any expected interference effects, while these with common activity periods should not be consolidated. The analysis of one of Google's data centers unveils that most of the services can be mapped onto one of the two patterns, while few with undetermined relation remain. The ND-CSP is extended by the 'overlap coefficient' and approximatively solved. In contrast to the former ND-CSP, neither an improvement nor a deterioration of the consolidation results is obtained. In the future, the services can be allocated with reduced or even without interference effects if an exact solution or a multi-objective optimization is applied.
Книги з теми "Overall energy efficiency":
1
Dukert, Joseph M. Energy. Greenwood, 2008. http://dx.doi.org/10.5040/9798400646065.
Анотація:
Energy: We want it affordable, we want it available in ample quantities and from reliable sources, and we want it to be produced and used in ways that are safe and environmentally benign. In other words, we want plenty of energy too cheap to meter and with no impact on the environment. Ha! With a refreshing lack of bias, this book dissects all major sources of energy, from oil and coal to renewables like solar and wind power. In an easy, understandable style, energy expert Joseph Dukert explains how each fits into the overall global energy mix that powers everything from automobiles and appliances to assembly lines and space stations. As Dukert details, all energy sources have pluses and minuses. Those who champion any single energy source (or even energy efficiency by itself) as the sole answer to our energy problems are off track, he argues, as are the cynics who condemn one source or another or pooh-pooh the threat of global warming. In short, we need every significant source of energy we have today, while also making greater efforts to improve the efficiency of energy production and energy consumption. Dukert also explores the choices made by individuals, businesses, and society as each group juggles conflicting, interconnected factors: affordability, reliability, adequacy of supply, environmental concerns, and time. In explaining why there's no magic bullet solution to the energy crisis, the author blends simple technical descriptions, economics, and real-world politics. Besides providing a cogent overview of a huge—and hugely important—industry, this short, comprehensive volume helps readers decide for themselves which choices are in their best interest. As Dukert suggests, energy independence is probably not a realistic goal for any country, but the search for a dynamic, practical energy balance can nonetheless result in a wiser national energy policy.
2
González Huerta, R. G., J. M. Sandoval Pineda, N. Hernández Pérez, and E. Álvarez del Rio. Interconnection to the network and energy storage systems. State of the art. EPOMEX-UAC, 2017. http://dx.doi.org/10.26359/epomex.cemie022017.
Анотація:
For technical reasons, the amount of electricity fed to the electrical grid must always remain at the same level of the demand requested by theconsumers to prevent blackouts and damage to the network. This leads to situations where production is greater than consumption and vice versa. This is where storage system technologies and interconnection to the network play a key role in balancing these disadvantages. Untilrecently, the utility of energy storage systems was focused on improving the efficiency of conventional generation systems, such as the use of pumped hydroelectricity to supplement the supply to the network in periods of extra demand or for plant start-ups. This type of storage technology is today the most reliable and in many ways the only one economically available. However, its use it is limited to specific cases that meet strict characteristics. Currently globally, the approach to storage technologies of energy, is to help improve the overall sustainability of large quantities of renewable energies, coming from intermittent sources such like the sun, the sea or the wind
3
Schurr, Sam H., Calvin C. Burwell, Warren S. Devine, and Sidney Sonenblum. Electricity in the American Economy. Greenwood Publishing Group, Inc., 1990. http://dx.doi.org/10.5040/9798216186588.
Анотація:
Electricity has penetrated deeply into virtually every aspect of American life, be it in industry, the home, or in the rapidly growing commercial and service sectors. This book documents and analyzes the existence of a strong, and growing, synergy between technological progress and the use of electrified production techniques in the United States during the twentieth century. The authors use two types of information in their work: case studies of the ways in which technological progress in particular industries and economic sectors has depended upon the adoption of electrified methods of production and aggregative long-term national economic statistics that measure the changing relationship over time between increases in the use of electricity and other factor inputs and the growth in industrial productivity. Eleven of the book's thirteen chapters cover the case studies, while the remaining two chapters and the statistical appendix contain the broad quantitative findings and supporting data. In their analysis, the authors address three inter-related questions from a long-term evolutionary perspective: Why has electricity's share of total energy risen so sharply over the years? How has this rise been related to productivity growth? and Why has the rise in electricity led to long-term improvements in the efficiency of overall energy use despite the thermal energy losses sustained when fuels are converted into electricity? The answer to these questions, they contend, is the technological progress represented by electrified production technologies, and in the new ways of organizing production that are now possible. The different ways in which electrical energy has been put to work, and with what results, are examined in the various case studies presented, and further documented in the aggregative statistical analysis. This study reveals the important role that the electrification of production operations has played in supporting productivity growth in manufacturing and other economic sectors in the past, and the important part that it can continue to play in the future. This book will appeal to a broad spectrum of readers; those interested in productivity issues, energy policy, electricity in general, historians of technology, economic historians, and those interested in current technological issues. It will be a necessary acquisition for college and university libraries, as well as those individuals interested in energy, technology, economic growth, history, and the interfaces among them.
4
Fitzgerald, Joan. Greenovation. Oxford University Press, 2020. http://dx.doi.org/10.1093/oso/9780190695514.001.0001.
Анотація:
Collectively, cities take up a relatively tiny amount of land on the earth, yet emit 72 percent of greenhouse gas emissions. Clearly, cities need to be at the center of any broad effort to reduce climate change. This book argues that too many cities are only implementing random acts of greenness that will do little to address the climate crisis. It instead calls for “greenovation”—using the city as a test bed for adopting and perfecting green technologies for more energy-efficient buildings, transportation, and infrastructure more broadly. Further, the text contends that while many city mayors cite income inequality as a pressing problem, few cities are connecting climate action and social justice—another aspect of greenovation. Focusing on the biggest producers of greenhouse gases in cities, buildings, energy, and transportation, the book examines how greenovating cities are reducing emissions overall and lays out an agenda for fostering and implementing urban innovations that can help reverse the path toward irrevocable climate damage. Drawing on interviews with practitioners in more than 20 North American and European cities, the book identifies the strategies and policies they are employing and how support from state, provincial, and national governments has supported or thwarted their efforts.
5
Andrews, Rob, and Clare England. Poor diets. Edited by Patrick Davey and David Sprigings. Oxford University Press, 2018. http://dx.doi.org/10.1093/med/9780199568741.003.0335.
Анотація:
Apart from breast milk, no single food contains all the essential nutrients the body needs to be healthy and function efficiently. The nutritional value of a person’s diet depends on the overall balance of foods eaten over a period of time, as well as on the needs of the individual. Over the last 60 years, there has been increasing agreement about the balance of nutrients and foods that make up a ‘good’ diet. This consists primarily of wholegrains (i.e. cereal grains, or foods made from them, containing bran, germ, and endosperm, e.g. wholemeal breads, oatmeal, and dark rye); vegetables and fruit, including nuts and pulses; moderate amounts of fish and low-fat dairy foods; and limited amounts of meat. The consumption of saturated fat should be low, with saturated fat being replaced by mono- and polyunsaturated vegetable fats and fish oils. Trans-fatty acids should be minimized, and added sugar should provide no more than 10% of energy intake. However, as omnivores, humans can survive on a wide range of different foods, and many people worldwide eat diets that fall far short of this ideal.
6
Stefańska, Magdalena, ed. Sustainability and sustainable development. Wydawnictwo Uniwersytetu Ekonomicznego w Poznaniu, 2021. http://dx.doi.org/10.18559/978-83-8211-074-6.
Анотація:
The aim of this book is to present the most important issues related to sustainable development (SD) and corporate social responsibility (CSR). They are discussed from a macro and micro perspective, both in the form of theoretical foundations of these concepts and practical examples of companies operating in Central and Eastern European countries that have implemented these ideas in their daily operations and translated them into corporate and functional strategies. The book consists of four parts. The first one is theoretical in its assumptions and is devoted to explaining the key concepts of sustainable development (SD) and corporate social responsibility (CSR). The authors describe the determinants of sustainable development in the contemporary world, including the most important ones, such as globalization, climate change, poverty, unlimited consumption, as well as limited access to natural resources - all in relation to the goals of sustainable development. The chapter also discusses the concept of corporate social responsibility (CSR), which is now recognized as the process by which business contributes to the implementation of sustainable development. How sustainable development (SD) and corporate social responsibility (CSR) are incorporated into the organization's strategies and influence the corporate strategy on the corporate and functional areas of the organization is presented in the last chapter of the first part of the e-book. The next part of the e-book helps readers understand the concepts of SD and CSR in the field of organizational strategy - in strategic management, and at the level of functional strategies—marketing, human resources, marketing research, accounting and operational management. The authors explain the reasons why companies need to consider the local and global perspective when setting SDGs, and the existence of potential conflicts within them. Taking into account the area of marketing, the authors point to the increase in environmental and social awareness of all stakeholders, which translates into changes in the criteria for decision-making by managers and risk assessment. The issue of sustainability is also the subject of market research. Companies producing products and services, institutions dealing with environmental or consumer protection, scientists and students conduct many research projects related to, inter alia, much more. How to use secondary data for analysis and how to prepare, conduct, analyze and interpret the results of primary research in that area are discussed in detail in the next chapter of this section. The concept of SD also refers to the basic functions of human resource management (HRM)—recruitment, motivation, evaluation and control. They should take into account SD not only for the efficiency of the organization and long-term economic benefits, but also for ethical reasons. Thanks to the SHRM, the awareness and behavior of the entire organization can strongly express sustainable goals in the planning and implementation of the overall corporate strategy. The growing importance of the idea of SD and the concept of CSR also resulted in the need for accounting and finance to develop solutions enabling the provision of information on the methods and results of implementing these concepts in entities operating on the market. This part of the book also examines manufacturing activities in the context of sustainability. As a result, many problems arise: waste of resources, mismanagement, excessive energy consumption, environmental pollution, use of human potential, etc. The chapter presents such concepts as: zero-waste, lean-manufacturing, six-sigma, circular production, design and recycling products in the life cycle as well as ecological and environmentally friendly production. The next two parts of the e-book contain examples of companies from Central and Eastern Europe that used SD goals in their strategies, questions and tasks for readers.
Частини книг з теми "Overall energy efficiency":
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Yang, Ming, and Xin Yu. "Overall Methodology in This Study." In Energy Efficiency, 43–48. London: Springer London, 2015. http://dx.doi.org/10.1007/978-1-4471-6666-5_5.
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Nomura, Koji. "Energy Productivity and Overall Efficiency." In Energy Productivity and Economic Growth, 121–76. Singapore: Springer Nature Singapore, 2022. http://dx.doi.org/10.1007/978-981-19-6494-7_4.
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Salvia, Amanda Lange, and Lucas Leandro Schneider. "Overall Energy Efficiency and Sustainable Development." In Encyclopedia of Sustainability in Higher Education, 1231–38. Cham: Springer International Publishing, 2019. http://dx.doi.org/10.1007/978-3-030-11352-0_463.
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Salvia, Amanda Lange, and Lucas Leandro Schneider. "Overall Energy Efficiency and Sustainable Development." In Encyclopedia of Sustainability in Higher Education, 1–8. Cham: Springer International Publishing, 2019. http://dx.doi.org/10.1007/978-3-319-63951-2_463-1.
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Maeda, Kazuhiko, Tsuyoshi Takata, and Kazunari Domen. "(Oxy)nitrides and Oxysulfides as Visible-Light-Driven Photocatalysts for Overall Water Splitting." In Energy Efficiency and Renewable Energy Through Nanotechnology, 487–529. London: Springer London, 2011. http://dx.doi.org/10.1007/978-0-85729-638-2_14.
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Dharmowijoyo, Dimas B. E., and Tri Basuki Joewono. "Mobility and Health: The Interaction of Activity-Travel Patterns, Overall Well-Being, Transport-Related Social Exclusion on Health Parameters." In Energy Efficiency in Mobility Systems, 53–83. Singapore: Springer Singapore, 2019. http://dx.doi.org/10.1007/978-981-15-0102-9_4.
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Ioshchikhes, Borys, Daniel Piendl, Henrik Schmitz, Jasper Heiland, and Matthias Weigold. "Development of a Holistic Framework for Identifying Energy Efficiency Potentials of Production Machines." In Lecture Notes in Mechanical Engineering, 431–39. Cham: Springer International Publishing, 2023. http://dx.doi.org/10.1007/978-3-031-28839-5_48.
Анотація:
AbstractA prerequisite to identify energy efficiency potentials and to improve energy efficiency is the measurement and analysis of the energy demand. However, in industrial practice, approaches to identify energy efficiency measures of production machines are associated with high costs for metering equipment and time consuming analysis requiring expertise. Against this background, this paper describes a comprehensive and cost-efficient framework from acquisition to analysis of energy data to serve as a starting point to increase energy efficiency in manufacturing. For this purpose, an energy transparency and analysis system is being developed that can measure, record and analyze electrical quantities. The validity of the data acquisition can be verified by utilizing a Raspberry Pi as a low-cost edge analyzer device. Measurement data is stored with associated metadata in a SQLite database for subsequent processing in a Python-based web application, in which machine learning algorithms can be deployed. The algorithms can be used to process vast amounts of data and to provide a basis for calculating energy performance indicators to reveal energy efficiency potentials. The overall workflow is validated using a lathe and a cleaning machine within the ETA Research Factory at the Technical University of Darmstadt.
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Mose, Christian, and Nils Weinert. "Evaluation of Process Chains for an Overall Optimization of Manufacturing Energy Efficiency." In Advances in Sustainable and Competitive Manufacturing Systems, 1639–51. Heidelberg: Springer International Publishing, 2013. http://dx.doi.org/10.1007/978-3-319-00557-7_132.
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Mpawenayo, Prosper. "Study of the Overall Efficiency of a 7 pkw Solar Photovoltaic Pumpng System at Mugombwa (Rwanda)." In Tenth E.C. Photovoltaic Solar Energy Conference, 1122–25. Dordrecht: Springer Netherlands, 1991. http://dx.doi.org/10.1007/978-94-011-3622-8_287.
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Salim, Sherna, and Amin Al-Habaibeh. "Exploring Windows Opening Behaviour of Occupants of Residential Buildings Using Artificial Intelligence." In Springer Proceedings in Energy, 311–21. Cham: Springer Nature Switzerland, 2023. http://dx.doi.org/10.1007/978-3-031-30960-1_29.
Анотація:
AbstractThe residential sector contributes significantly to the overall energy consumption in the UK. Occupant’s behaviour is a major factor that sometimes could be overlooked when considering energy efficiency of buildings. Although building simulations play a major role in the design of energy efficient buildings, significant discrepancies have been seen between the actual and predicted energy values in simulation models. This is because simulation does not consider occupant behaviour in many cases or finds it difficult to present such behaviour. This study attempts to investigate the reason behind occupant’s behaviour of windows opening; to analyse the collected data, to understand the occurrences that lead to an occupant opening window in a residential building. In this paper, data were collected from a selected house in Nottingham. Data were experimentally collected in peak winter of 2020, from end of Nov/20 to March/21 during Covid-19 pandemic. Sensors were fitted to measure radiator temperature, room temperature, room humidity and near-window temperature both upstairs and downstairs. Outdoor ambient temperature for the same period was also collected. Stochastic models were implemented with datasets with window opening behaviour as response. The input parameters to the model were the radiator temperature, room temperature, outside ambient temperature, and time. The predicated output was the window status (open/close). The prognostic precision of the suggested model was verified by testing the models with the rest of the collected data. The predicted values were compared with the actual measured values. The results show a strong prediction with success rate of 76.2%. The findings from this investigation have been found to be able to identify the factors that contribute to the ‘performance gap’ in energy efficiency of a building.
Тези доповідей конференцій з теми "Overall energy efficiency":
1
Kost, Alan R. "Comparison of the Overall Efficiency of Fresnel and Prismatic Solar Concentrators." In Optics for Solar Energy. Washington, D.C.: OSA, 2013. http://dx.doi.org/10.1364/ose.2013.rt2d.4.
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Wong, Adam J., Jorge E. Gonza´lez, Sergio Escobar, and Mark Aschheim. "On the Overall Energy Efficiency of a High-Performance Solar Energy Residential Building." In ASME 2010 International Mechanical Engineering Congress and Exposition. ASMEDC, 2010. http://dx.doi.org/10.1115/imece2010-39662.
Анотація:
This paper describes the energy performance of a solar house over its first year of monitoring. The 2007 Solar Decathlon house currently sits on Santa Clara University’s campus at 60.4 m2. The house is powered entirely by solar PV and solar thermal off the grid. This solar energy house is heavily instrumented with more than 100 sensors to measure temperatures, humidity, power consumption of electric appliances, lighting, water, and performance of a 7.2 kW solar PV array and a sophisticated HVAC system. The instrumentation includes a full weather station. The house is divided into two interconnected modules, and constructed with high thermal insulation and sustainable materials. The instrumentation also allows quantifying energy performance of individual components as well as the overall energy performance of the house. The paper focuses on the complete energy balance of the house as a function of weather conditions, and of the performance of individual components. Of particular interest is the performance of the solar PV and solar thermal systems. The solar thermal system includes an absorption air conditioning unit, integrated with a thermal storage tank to provide all energy needs for water consumption and heating. The I-V curves of the full PV array are reported, demonstrating peak, off-peak, and seasonal performance and deviations from manufacturers’ conditions. Similarly, the overall COP of the solar-driven HVAC system is reported for both cooling and heating modes. Finally, it is shown how data can be used to demonstrate improvement of simulation tools for solar building energy performance. Although data has been collected since March 2009, this paper focuses on performance during summer 2009.
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Tao, Yong X., Joseph Woods, and Julian Lamb. "EFFECT OF UNDELIVERED ENERGY AND DYNAMIC DEMAND ON OVERALL DISTRICT ENERGY SYSTEM EFFICIENCY." In 7th Thermal and Fluids Engineering Conference (TFEC). Connecticut: Begellhouse, 2022. http://dx.doi.org/10.1615/tfec2022.est.041027.
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Zhang, Yeming, Maolin Cai, and Dewen Kong. "Overall Energy Efficiency of Lubricant-Injected Rotary Screw Compressors and Aftercoolers." In 2009 Asia-Pacific Power and Energy Engineering Conference. IEEE, 2009. http://dx.doi.org/10.1109/appeec.2009.4918581.
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Gbenga, Ayegbusi Olutobi, Abdullah Sani Ahmad, Yaik Wah Lim, and Dilshan Remaz Ossen. "Understanding Overall Thermal Transfer Value as a Building Energy Efficiency Indicator." In 1st Annual International Conference on Urban Planning and Property Development (UPPD 2015). Global Science & Technology Forum (GSTF), 2015. http://dx.doi.org/10.5176/2425-0112_uppd15.14.
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Gromov, Yuri, Yuri Minin, Aleksey Eliseev, Ali Abdulkarem Habib Alrammahi, and Farah Abbac Sari. "Overall Score of Information System Perfomance and Selection of Synthesis Problem." In 2019 1st International Conference on Control Systems, Mathematical Modelling, Automation and Energy Efficiency (SUMMA). IEEE, 2019. http://dx.doi.org/10.1109/summa48161.2019.8947606.
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Hasanzadeh, Saeed, and Sadegh Vaez-Zadeh. "Enhancement of overall coupling coefficient and efficiency of contactless energy transmission systems." In Technologies Conference (PEDSTC). IEEE, 2011. http://dx.doi.org/10.1109/pedstc.2011.5742498.
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Alameri, S., M. Ali, A. Alkaabi, and M. Alrwashdeh. "Effect of Thermal Energy Storage Integration on Overall Nuclear Power Plant Efficiency." In Tranactions - 2019 Winter Meeting. AMNS, 2019. http://dx.doi.org/10.13182/t30837.
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Nasrin, Rehena, and Tasmin Akter Tripty. "Numerical Evaluation of Overall Efficiency for Solar Photovoltaic and Thermal Hybrid System." In 2023 IEEE Conference on Power Electronics and Renewable Energy (CPERE). IEEE, 2023. http://dx.doi.org/10.1109/cpere56564.2023.10119575.
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Yina Xu and Lei Zhang. "Study on energy efficiency design of public building base on overall consideration of energy consumption factors." In 2011 International Conference on Multimedia Technology (ICMT). IEEE, 2011. http://dx.doi.org/10.1109/icmt.2011.6002767.
Звіти організацій з теми "Overall energy efficiency":
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Pedraza, Arturo, Paola Méndez, and Rodrigo Riquelme. Energy Efficiency in Water Utilities: The Case of Guyana. Inter-American Development Bank, October 2016. http://dx.doi.org/10.18235/0009315.
Анотація:
Energy consumption in the water sector is extremely important. Energy is needed throughout the entire process of drinking water generation and treatment. Estimates indicate that electricity expenses may represent as much as 40% of the total operating costs of a water and sanitation (W&S) utility. Conversely, energy consumption of W&S utilities often represent animportant proportion of the total electricity generated in a country. Yet, energy consumed by W&S utilities is not always used efficiently. This technical note aims to highlight how water and sanitation utilities can increase their energy efficiency, reducing operational costs and impacting positively the overall operational efficiency of W&S utilities. To illustrate this, the technical note takes as an example a pilot project carried out in the Guyana Water and Sanitation Utility - Guyana Water Incorporated (GWI).
2
Salmeri, Micol, Richard Rugg, Paul Wedgwood, and Roberto Gabriel Aiello. Developing Clean Energy Solutions in Latin America’s Major Cities: An Introduction for Subnational Energy Policy Decision-Makers. Inter-American Development Bank, December 2017. http://dx.doi.org/10.18235/0006480.
Анотація:
This publication is intended to help sub-national energy policy decision-makers of major Latin American cities as they look to develop and implement clean energy solutions. Our aim is to help local actors to understand, plan and execute initiatives successfully which, over time, will: save money, while increasing energy security, increase standards of living and the supply of more efficient and sustainable energy solutions, and reduce the overall use of energy and greenhouse gas emissions. While each city has its own individual circumstances, many common challenges are faced by major cities which can prevent the uptake of opportunities for improved energy management, energy efficiency and innovation in their energy systems. Due to the sheer size and complexity of large and megacities such challenges are typically exacerbated; yet the scale of the opportunities and related potential benefits are also much more significant. Clean energy solutions have delivered substantial benefits to millions of citizens and thousands of businesses and civic institutions, providing material positive social, economic and environmental impacts. Latin America is one of the world’s most urbanised regions, with over 80 percent of its population living in cities. The region is currently home to five megacities (Buenos Aires, Lima, Mexico City, Rio de Janeiro and São Paolo). It is anticipated that by 2050 over 86 percent of Latin America’s population will live in urban areas.
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Mizrahi, Itzhak, and Bryan A. White. Uncovering rumen microbiome components shaping feed efficiency in dairy cows. United States Department of Agriculture, January 2015. http://dx.doi.org/10.32747/2015.7600020.bard.
Анотація:
Ruminants provide human society with high quality food from non-human-edible resources, but their emissions negatively impact the environment via greenhouse gas production. The rumen and its resident microorganisms dictate both processes. The overall goal of this project was to determine whether a causal relationship exists between the rumen microbiome and the host animal's physiology, and if so, to isolate and examine the specific determinants that enable this causality. To this end, we divided the project into three specific parts: (1) determining the feed efficiency of 200 milking cows, (2) determining whether the feed- efficiency phenotype can be transferred by transplantation and (3) isolating and examining microbial consortia that can affect the feed-efficiency phenotype by their transplantation into germ-free ruminants. We finally included 1000 dairy cow metadata in our study that revealed a global core microbiome present in the rumen whose composition and abundance predicted many of the cows’ production phenotypes, including methane emission. Certain members of the core microbiome are heritable and have strong associations to cardinal rumen metabolites and fermentation products that govern the efficiency of milk production. These heritable core microbes therefore present primary targets for rumen manipulation towards sustainable and environmentally friendly agriculture. We then went beyond examining the metagenomic content, and asked whether microbes behave differently with relation to the host efficiency state. We sampled twelve animals with two extreme efficiency phenotypes, high efficiency and low efficiency where the first represents animals that maximize energy utilization from their feed whilst the later represents animals with very low utilization of the energy from their feed. Our analysis revealed differences in two host efficiency states in terms of the microbial expression profiles both with regards to protein identities and quantities. Another aim of the proposal was the cultivation of undescribed rumen microorganisms is one of the most important tasks in rumen microbiology. Our findings from phylogenetic analysis of cultured OTUs on the lower branches of the phylogenetic tree suggest that multifactorial traits govern cultivability. Interestingly, most of the cultured OTUs belonged to the rare rumen biosphere. These cultured OTUs could not be detected in the rumen microbiome, even when we surveyed it across 38 rumen microbiome samples. These findings add another unique dimension to the complexity of the rumen microbiome and suggest that a large number of different organisms can be cultured in a single cultivation effort. In the context of the grant, the establishment of ruminant germ-free facility was possible and preliminary experiments were successful, which open up the way for direct applications of the new concepts discovered here, prior to the larger scale implementation at the agricultural level.
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Birchmore, Roger. Medium-density Dwellings in Auckland and the Building Regulations. Unitec ePress, July 2018. http://dx.doi.org/10.34074/ocds.0822.
Анотація:
National thermal standards have historically been set to minimise winter heating energy in detached houses. It is uncertain whether these standards are optimal for the increasing number of joined, medium-density dwellings when summer and winter conditions are considered. Using freely available software, annual heating energy use and summertime peak temperatures were calculated for a number of versions of detached and joined dwellings offering the same occupied volume and window areas. Initial results indicated that, as expected, the joined dwellings required less heating energy. The detached house exhibited a higher peak summertime temperature but a lower overall average daily temperature. Interventions such as changing insulation, glazing areas and ventilation were calculated to reduce summertime temperatures in the joined dwelling. Increasing ventilation provided the greatest improvement particularly during the sensitive sleeping hours. Changes to clauses H1 Energy Efficiency, G4 ventilation and G6 Airborne and Impact Sound are recommended if these early findings are confirmed in a more complex simulation.
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Jesper, M., and F. Pag. Integration Concepts and Design Guidelines. IEA SHC Task 63, March 2024. http://dx.doi.org/10.18777/ieashc-task64-2024-0002.
Анотація:
The defossilization of the industrial heat supply is crucial for achieving the Paris climate targets. For the defossilization of heat with supply temperatures of at least 150 °C, solar thermal heat for industrial processes (SHIP) and heat pumps (HP) are technically mature technologies that allow a complete substitution of fossilfueled systems already today [1]. However, the individual potential of these technologies is often limited by restrictions regarding the availability of renewable energy sources, e.g., solar radiation, environmental or excess heat, or by technical limitations, e.g., the available space for solar thermal collectors. The combination of both technologies could, therefore, be a solution to maximize the degree of defossilization and overall efficiency.
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Hicks, Jacqueline. Environmental Challenges of Digital Transformation in Developing Countries. Institute of Development Studies (IDS), July 2021. http://dx.doi.org/10.19088/k4d.2021.107.
Анотація:
This rapid review synthesises the literature on the environmental risks of four different aspects of digital transformation in developing countries: ICT adoption, digitally-enabled energy efficiency, ride-hailing apps, and big data use. The overall message which runs throughout the diverse literatures and results is that it is not digital technologies that create environmental risks or opportunities, but how they are used. Efficiency gains derived from digital transformation may yet lead developing countries down existing unsustainable development paths if not accompanied by careful, context-dependent policy. For policy-makers seeking to mitigate environmental risks, this means putting the context of digital use at the centre of analysis rather than the technologies themselves. However, the research literature covers more specific aspects of digital transformation. In practice, this report defines digital transformation as: ICT adoption, digitally-enabled energy efficiency, ride-hailing apps, and big data use. These topics were chosen after an initial scoping review of available literature, and because they exemplify a range of the different types of potential digital effects. The literature on the environmental risks of digital transformation is huge and conflicting. This is problematic because it could be easy to cherry pick preferred research results. Several studies noted that there is less research on developing countries than developed countries, but the evidence base is still large. As an evidence review, this report focused on the academic literature, but there is also a large grey literature. Some of the literature has a gender aspect, not covered in this report.
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Shan, Yina, Praem Mehta, Duminda Perera, and Yurissa Yarela. Cost and Efficiency of Arsenic Removal from Groundwater: A Review. United Nations University Institute for Water, Environment and Health, February 2019. http://dx.doi.org/10.53328/kmwt2129.
Анотація:
Hundreds of millions of people worldwide are exposed to arsenic-contaminated drinking water, leading to significant health complications, and social and economic losses. Currently, a wide range of technologies exists to remove arsenic from water. However, despite ongoing research on such technologies, their widespread application remains limited. To bridge this gap, this review aims to compare the effectiveness and costs of various arsenic remediation technologies while considering their practical applicability. A search conducted using the Medline and Embase databases yielded 31 relevant articles published from 1996 to 2018, which were categorized into laboratory and field studies. Data on the effectiveness of technologies in removing arsenic and associated costs were extracted and standardized for comparison as much as was possible, given the diversity of ways that studies report their key results. The twenty-three (23) technologies tested in laboratory settings demonstrated efficiencies ranging from 50% to ~100%, with the majority reaching relatively high removal efficiencies (>90%). Approximately half achieved the WHO standard of 10 µg/L. Laboratory studies used groundwater samples from nine (9) different countries – Argentina, Bangladesh, Cambodia, China, Guatemala, India, Thailand, the United States, and Vietnam. The fourteen (14) technologies tested in the field achieved removal efficiency levels ranging between 60% and ~99%, with ten (10) attaining above 90% removal efficiency. Of these, only five (5) reached established the WHO standard. Some of the technologies under-performed when their influent water contained excessive concentrations of arsenic. Only six (6) countries (Argentina, Bangladesh, Chile, China, India, and Nicaragua) were represented among the studies that implemented and tested technologies in the field, either at household or community level. For technologies tested in the laboratory, the cost of treating one cubic meter of water ranged from near-zero to ~USD 93, except for one technology which cost USD 299/m³. For studies conducted in the field, the cost of treating one cubic meter of water ranged from near-zero to ~USD 70. Key factors influencing the removal efficiencies and their costs include the arsenic concentration of the influent water, pH of the influent water, materials used, the energy required, absorption capacity, labour used, regeneration period and geographical location. Technologies that demonstrate high removal efficiencies when treating moderately arsenic-contaminated water may not be as efficient when treating highly contaminated water. Also, the lifetime of the removal agents is a significant factor in determining their efficiency. It is suggested that remediation technologies that demonstrate high arsenic removal efficiencies in a laboratory setting need to be further assessed for their suitability for larger-scale application, considering their high production and operational costs. Costs can be reduced by using locally available materials and natural adsorbents, which provide near zero-cost options and can have high arsenic removal efficiencies. A notable feature of many arsenic removal approaches is that some countries with resource constraints or certain environmental circumstances – like typically high arsenic concentrations in groundwater –aim to reach resultant arsenic concentrations that are much higher than WHO’s recommended standard of 10 µg/L. This report maintains that – while this may be a pragmatic approach that helps progressively mitigate the arsenic-related health risks – it is unfortunately not a sustainable solution. Continuing exposure to higher levels of arsenic ingestion remains harmful for humans. Hence arsenic-removal technology should only be seen efficient if it can bring the water to the WHO standard. A less radical approach effectively shifts the attention from the origin of the problem in addressing the impacts and postpones achieving the best possible outcome for populations. The quantitative summary of costs and effectiveness of arsenic remediation technologies reviewed in this report can serve as a preliminary guideline for selecting the most cost-effective option. It may also be used as an initial guideline (minimum standard) for summarising the results of future studies describing arsenic remediation approaches. Looking ahead, this study identifies four priority areas that may assist in commercializing wide-scale implementation of arsenic removal technologies. These include: i) focusing efforts on determining market viability of technologies, ii) overcoming practical limitations of technologies, iii) determining technology contextual appropriateness and iv) concerted effort to increase knowledge sharing in and across regions to accelerate the implementation of research on the ground. Overall, the current science and knowledge on arsenic remediation technologies may be mature enough already to help significantly reduce the global numbers of affected populations. The missing link for today’s arsenic removal challenge is the ability to translate research evidence and laboratory-level successes into quantifiable and sustainable impacts on the ground. Achieving this requires a concerted and sustained effort from policymakers, engineers, healthcare providers, donors, and community leaders.
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Walker, S., A. Gross, D. Jassby, and W. Tester. Energy, nutrient and water recovery from dairy waste. Israel: United States-Israel Binational Agricultural Research and Development Fund, 2020. http://dx.doi.org/10.32747/2020.8134167.bard.
Анотація:
The overall goal of this project was to investigate an innovative integrated approach to extracting energy, clean water, and valuable nutrients efficiently from the estimated 180-190 million cubic meters of effluent left behind after anaerobic digestion (AD) of dairy manure and related food wastes. In addition to producing new value streams, this process can reduce or eliminate the need for application of anaerobic digestate on land, which can pollute air and water.
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Pradhananga, Manisha, David A. Raitzer, Iva Sebastian-Samaniego, and Daryll Naval. Decarbonization Pathways in Developing Asia: Evidence from Modeling Scenarios. Asian Development Bank, December 2023. http://dx.doi.org/10.22617/wps230593-2.
Анотація:
The Sixth Assessment Report of the Intergovernmental Panel on Climate Change incorporated an ambitious model intercomparison effort that compiled thousands of model-scenario combinations to consider low carbon development pathways. This paper explores the evidence within that database to consider decarbonization pathways for developing Asia. Overall, a comparison of the major models finds strong consistency in the transformation of the energy sector required to achieve Paris Agreement goals. This includes a rapid decline in the share of coal—a mainstay of the power sector in developing Asia— and a substantial rise in renewable energy. The cost of the transition can be relatively low if mitigation efforts are efficient, as assumed in the models.
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Cahaner, Avigdor, Sacit F. Bilgili, Orna Halevy, Roger J. Lien, and Kellye S. Joiner. effects of enhanced hypertrophy, reduced oxygen supply and heat load on breast meat yield and quality in broilers. United States Department of Agriculture, November 2014. http://dx.doi.org/10.32747/2014.7699855.bard.
Анотація:
Original objectivesThe objectives of this project were to evaluate the growth performance, meat yield and quality attributes of broiler strains widely differing in their genetic potential under normal temperature vs. warm temperature (short and long-term) conditions. Strain differences in breast muscle accretion rate, metabolic responses under heat load and, gross and histopathological changes in breast muscle under thermal load was also to be characterized. BackgroundTremendous genetic progress has been made in broiler chicken growth rate and meat yield since the 1950s. Higher growth rate is driven by higher rates of feed intake and metabolism, resulting in elevated internal heat production. Hot rearing conditions negatively affect broiler growth by hindering dissipation of heat and may lead to a lethal elevation in body temperature. To avoid heat-induced mortality, broilers reduce feed intake, leading to depressed growth rate, lower weight gain, reduce breast meat yield and quality. Thus, the genetic potential of contemporary commercial broilers (CCB) is not fully expressed under hot conditions. Major conclusions, solutions, and achievementsResearch conducted in Israel focused on three broiler strains – CCB, Featherless, Feathered sibs (i.e., sharing similar genetic background). Complimentary research trials conducted at Auburn utilized CCB (Cobb 500, Cobb 700, Ross 308, Ross 708), contrasting their performance to slow growing strains. Warm rearing conditions consistently reduced feed intake, growth rate, feed efficiency, body weight uniformity and breast muscle yield, especially pronounced with CCB and magnified with age. Breast meat quality was also negatively affected, as measured by higher drip loss and paler meat color. Exposure to continuous or short-term heat stress induced respiratory alkalosis. Breast muscle histomorphometrics confirmed enhanced myofiber hypertrophy in CCB. Featherless broilers exhibited a significant increase in blood-vessel density under warm conditions. Rapid growth and muscle accretion rate was correlated to various myopathies (white striping, woody and necrotic) as well as to increases in plasma creatinekinase levels. Whether the trigger(s) of muscle damage is loss of cellular membrane integrity due to oxidative damage or tissue lactate accumulation, or to loss of inter-compartmental cation homeostasis is yet to be determined. Based on genome-wide single-nucleotide polymorphism array genotyping, identification of the gene with the recessive mutation Scaleless (sc) facilitated the development a dCAPS assay to discriminate between sc carrier (sc/+) and non-carrier (+/+) individuals. ImplicationsThis project confirmed that featherless broiler strains grow efficiently with high yield and quality of breast meat, even under warm rearing conditions that significantly depress the overall performance of CCB. Therefore, broiler meat production in hot regions and climates can be substantially improved by introducing the featherless gene into contemporary commercial broiler stocks. This approach has become more feasible with the development of dCAPS assay. A novel modification of the PCR protocol (using whole blood samples instead of extracted DNA) may contribute to the efficient development of commercial featherless broiler strains. Such strains will allow expansion of the broiler meat production in developing countries in warm climates, where energy intensive environmental control of rearing facilities are not economical and easily achievable.