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Sergio Ulgiati - One of the best experts on this subject based on the ideXlab platform.
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Energy Quality emergy and transformity h t odum s contributions to quantifying and understanding systems
Ecological Modelling, 2004Co-Authors: Mark T. Brown, Sergio UlgiatiAbstract:Abstract We present in this article, a brief historical overview of the development of the concepts and theories of Energy Quality, and net Energy that were the precursors to emergy. The concepts evolved over decades, beginning in the 1950s with Odum’s work on tracing Energy flows in ecosystems. During the 1970s, Odum’s attention was drawn to larger scale systems that included the economies of humans and the concept of net Energy. In the 1980s, Odum quantified Energy Quality and defined it as a “donor-based” evaluation technique. In the 1990s, Energy Quality was further refined and rigorous definitions for “emergy” and “transformity” were given. The units of emergy were defined as solar emjoules (abbreviated seJ) and the units of transformity were seJ/J. In addition, we provide some insights into the types of processes and systems that have been evaluated using emergy methods.
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Energy Quality, emergy, and transformity: H.T. Odum’s contributions to quantifying and understanding systems
Ecological Modelling, 2004Co-Authors: Mark T. Brown, Sergio UlgiatiAbstract:Abstract We present in this article, a brief historical overview of the development of the concepts and theories of Energy Quality, and net Energy that were the precursors to emergy. The concepts evolved over decades, beginning in the 1950s with Odum’s work on tracing Energy flows in ecosystems. During the 1970s, Odum’s attention was drawn to larger scale systems that included the economies of humans and the concept of net Energy. In the 1980s, Odum quantified Energy Quality and defined it as a “donor-based” evaluation technique. In the 1990s, Energy Quality was further refined and rigorous definitions for “emergy” and “transformity” were given. The units of emergy were defined as solar emjoules (abbreviated seJ) and the units of transformity were seJ/J. In addition, we provide some insights into the types of processes and systems that have been evaluated using emergy methods.
Massimo Alioto - One of the best experts on this subject based on the ideXlab platform.
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CICC - Low-Swing Links with Dynamic Energy-Quality Trade-off for Error-Resilient Applications
2019 IEEE Custom Integrated Circuits Conference (CICC), 2019Co-Authors: Viveka Konandur Rajanna, Massimo AliotoAbstract:On-chip links significantly contribute to the consumption of systems on chip (SoCs), especially in highly-parallel architectures. Such architectures are widely used for several applications that are inherently error-resilient (e.g., vision, machine learning), in which the Energy-Quality tradeoff can be exploited to achieve significant reduction in Energy. This paper proposes the use of sub-word ranking and non-uniform swing to allow graceful Energy-Quality tradeoff in intra-chip communication links. The proposed techniques are demonstrated in a 28nm testchip that achieves up to 4.5X Energy saving over conventional full-Quality links, and up to 2.2X over approximate links at iso-Quality. Conventional operation with no Quality degradation is also allowed for data packets that require full Quality.
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Token-Based Security for the Internet of Things With Dynamic Energy-Quality Tradeoff
IEEE Internet of Things Journal, 2019Co-Authors: Muhammad Naveed Aman, Sachin Taneja, Biplab Sikdar, Kee Chaing Chua, Massimo AliotoAbstract:In this paper, token-based security protocols with dynamic Energy-security level tradeoff for Internet of Things (IoT) devices are explored. To assure scalability in the mechanism to authenticate devices in large-sized networks, the proposed protocol is based on the OAuth 2.0 framework, and on secrets generated by on-chip physically unclonable functions. This eliminates the need to share the credentials of the protected resource (e.g., server) with all connected devices, thus overcoming the weaknesses of conventional client–server authentication. To reduce the Energy consumption associated with secure data transfers, dynamic Energy-Quality tradeoff is introduced to save Energy when lower security level (or, equivalently, Quality in the security subsystem) is acceptable. Energy-Quality scaling is introduced at several levels of abstraction, from the individual components in the security subsystem to the network protocol level. The analysis on an MICA 2 mote platform shows that the proposed scheme is robust against different types of attacks and reduces the Energy consumption of IoT devices by up to 69% for authentication and authorization, and up to 45% during data transfer, compared to a conventional IoT device with fixed key size.
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Approximate SRAMs With Dynamic Energy-Quality Management
IEEE Transactions on Very Large Scale Integration (VLSI) Systems, 2016Co-Authors: Fabio Frustaci, David Blaauw, Dennis Sylvester, Massimo AliotoAbstract:In this paper, approximate SRAMs are explored in the context of error-tolerant applications, in which Energy is saved at the cost of the occurrence of read/write errors (i.e., signal Quality degradation). This analysis investigates variation-resilient techniques that enable dynamic management of the Energy-Quality tradeoff down to the bit level. In these techniques, the different impacts of errors on Quality at different bit positions are explicitly considered as key enabler of Energy savings that are far larger than a simple voltage scaling. The analysis is based on the experimental results in an Energy-Quality scalable 28-nm SRAM and the extrapolation to a wide range of conditions through the models that combine the individual Energy contributions. Results show that the joint adoption of multiple bit-level techniques provides substantially larger Energy gains than individual techniques. Compared with the simple voltage scaling at isoQuality, the joint adoption of these techniques can provide more than $2\times $ Energy reduction at negligible area penalty. Energy savings turn out to be highly sensitive to the choice of joint techniques, thus showing the crucial importance of dynamic Energy-Quality management in approximate SRAMs.
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SRAM for Error-Tolerant Applications With Dynamic Energy-Quality Management in 28 nm CMOS
IEEE Journal of Solid-State Circuits, 2015Co-Authors: Fabio Frustaci, David Blaauw, Dennis Sylvester, Mahmood Khayatzadeh, Massimo AliotoAbstract:In this paper, a voltage-scaled SRAM for both error-free and error-tolerant applications is presented that dynamically manages the Energy/Quality trade-off based on application need. Two variation-resilient techniques, write assist and Error Correcting Code, are selectively applied to bit positions having larger impact on the overall Quality, while jointly performing voltage scaling to improve overall Energy efficiency. The impact of process variations, voltage and temperature on the Energy-Quality tradeoff is investigated. A 28 nm CMOS 32 kb SRAM shows 35% Energy savings at iso-Quality and operates at a supply 220 mV below a baseline voltage-scaled SRAM, at the cost of 1.5% area penalty. The impact of the SRAM Quality at the system level is evaluated by adopting a H.264 video decoder as case study.
Mark T. Brown - One of the best experts on this subject based on the ideXlab platform.
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Energy Quality emergy and transformity h t odum s contributions to quantifying and understanding systems
Ecological Modelling, 2004Co-Authors: Mark T. Brown, Sergio UlgiatiAbstract:Abstract We present in this article, a brief historical overview of the development of the concepts and theories of Energy Quality, and net Energy that were the precursors to emergy. The concepts evolved over decades, beginning in the 1950s with Odum’s work on tracing Energy flows in ecosystems. During the 1970s, Odum’s attention was drawn to larger scale systems that included the economies of humans and the concept of net Energy. In the 1980s, Odum quantified Energy Quality and defined it as a “donor-based” evaluation technique. In the 1990s, Energy Quality was further refined and rigorous definitions for “emergy” and “transformity” were given. The units of emergy were defined as solar emjoules (abbreviated seJ) and the units of transformity were seJ/J. In addition, we provide some insights into the types of processes and systems that have been evaluated using emergy methods.
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Energy Quality, emergy, and transformity: H.T. Odum’s contributions to quantifying and understanding systems
Ecological Modelling, 2004Co-Authors: Mark T. Brown, Sergio UlgiatiAbstract:Abstract We present in this article, a brief historical overview of the development of the concepts and theories of Energy Quality, and net Energy that were the precursors to emergy. The concepts evolved over decades, beginning in the 1950s with Odum’s work on tracing Energy flows in ecosystems. During the 1970s, Odum’s attention was drawn to larger scale systems that included the economies of humans and the concept of net Energy. In the 1980s, Odum quantified Energy Quality and defined it as a “donor-based” evaluation technique. In the 1990s, Energy Quality was further refined and rigorous definitions for “emergy” and “transformity” were given. The units of emergy were defined as solar emjoules (abbreviated seJ) and the units of transformity were seJ/J. In addition, we provide some insights into the types of processes and systems that have been evaluated using emergy methods.
Magnus Hultén - One of the best experts on this subject based on the ideXlab platform.
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Tension between visions of science education : The case of Energy Quality in Swedish secondary science curricula
Science Education, 2017Co-Authors: Jesper Haglund, Magnus HulténAbstract:The aim of this study is to contribute to an understanding of how curricular change is accomplished in practice, including the positions and conflicts of key stakeholders and participants, and their actions in the process. As a case, we study the treatment of Energy in Swedish secondary curricula in the period 1962–2011 and, in particular, how the notion of Energy Quality was introduced in the curricula in an Energy course at upper secondary school in 1983 and in physics at lower secondary school in 1994. In the analysis, we use Roberts’ two competing visions of science education, Vision I in which school science subjects largely mirror their corresponding academic disciplines and Vision II that incorporates societal matters of science. In addition, a newly suggested Vision III represents a critical perspective on science education. Our analysis shows how Vision II and III aspects of science education have gained importance in curricula since the 1980s, but in competition with Vision I considerations. Energy Quality played a central role in providing Vision II and III arguments in the curricular debate on Energy teaching. Subsequent educational research has found that Swedish teachers and students struggle with how to relate to Energy Quality in physics teaching, which we explain as partly due to the tension between the competing visions.
Janusz Mindykowski - One of the best experts on this subject based on the ideXlab platform.
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Methods and appropriate instrumentation for estimation of electrical Energy Quality
Measurement, 1998Co-Authors: Janusz Mindykowski, Tomasz TarasiukAbstract:Abstract In this paper basic information concerning the Quality of electrical Energy in a ship's power engineering system has been presented and new concepts of measurement of its factors in the system under consideration are proposed. Criteria of selection and proposals for defining related factors describing the electrical Energy Quality are presented. The factors of active and passive power distribution for generators working in parallel and also the signal distortion factor are more widely described. Moreover, the methods and related algorithms of distortion factor digital measurements are shown. The simulation research results concerning the considered algorithms are presented. Finally, directions of further work connected with the Quality of Energy produced and used in ship's electrical power systems are drafted. The basis of the presented paper may be found in the authors' earlier papers ([1] J. Mindykowski and T. Tarasiuk, Methods and appropriate instrumentation for determining of electrical Energy factors. 9th International Symposium IMEKO TC-4 , Glasgow, 8-9 September 1997, pp. 101-104; [2] J. Mindykowski and T. Tarasiuk, The influence of electrical Energy Quality on economical exploitation of ship technical systems. 4th International Conference EPQU'97 , Cracow, 23-25 September 1997,pp. 329-334).
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Specialized analyser for electrical Energy Quality estimation in ship electrical power system
IMTC 98 Conference Proceedings. IEEE Instrumentation and Measurement Technology Conference. Where Instrumentation is Going (Cat. No.98CH36222), 1Co-Authors: Janusz Mindykowski, T. TarasinkAbstract:This paper presents the problems of electrical Energy Quality estimation in ship electrical power system and describes the appropriate factors of this. These factors were worked out with the criterion of safe operation of ship technical systems. Economical aspects of the presented problems have only auxiliary importance. Special attention has been paid to instrumentation for electrical Energy estimation. In this context, the concept of a specialized analyser for electrical Energy Quality estimation is shown. The presented device was constructed with its own safety operation criteria and destined for use under assumption of temporary lack of service. For this reason, it has in particular, a distributed structure which contains autonomous modules. Moreover, some additional, autodiagnosis and emergency functions have been introduced. Taking into account measurement needs, the application of signal processors for analyser construction has been proposed.
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Problems of electrical Energy Quality estimation in ship electrical power system
IMTC 99. Proceedings of the 16th IEEE Instrumentation and Measurement Technology Conference (Cat. No.99CH36309), 1Co-Authors: Janusz Mindykowski, Tomasz TarasiukAbstract:This paper presents the basic problems connected with reliable estimation of Quality of electrical Energy. The critique of traditional approach to these problems is included as well as the approaches based on simple parametric factors and new synthetic factors have been shortly described. Some preliminary results based on the analysis of the real registered three-phase supply voltage waveforms on ship have been worked out. The block diagram and functions of microprocessor measurement diagnosis system oriented to electrical Energy Quality estimation have been described. Finally, applicability of the proposed method and new instrumentation for solving the problem under consideration have been discussed.