2012
Authors
Styczynski, Z; Stotzer, M; Muller, G; Komarnicki, P; Belmans, R; Driesen, J; Hansen, AB; Pecas Lopes, J; Hatziargyriou, N;
Publication
44th International Conference on Large High Voltage Electric Systems 2012
Abstract
In this contribution international experiences concerning the integration of electrified cars (e-cars) into the grid in particular when there is a high penetration of renewable energies are presented. Future shortage of fossil fuels and concerns about security of supply derived the idea of electrified mobility which requires a new approach to design a complex system for future transportation. This system will be based on existing infrastructures (electricity system, road infrastructure, etc.) but it can also partially be considered as a "green field" approach. In the paper new strategies and global trends in the development of an e-mobility system will be presented, including strategies to combine the power system with the information and communication systems as well as a logistics. Practical experiences and data based on few projects e.g. Harz.EE-Mobility in Germany. European research as well as industry projects with these aims will be introduced and results will be presented. The main focus is twofold: integrating the upcoming mobile loads into the grid and likely storage possibilities that can operate bidirectional within the power grid. Simulations show that single-phase charging (3.7 kW) in the low and medium voltage grid does not lead to grid situations that require any significant adjustments in the power network regarding the loading of the assets. However, uncoordinated single-phase charging could create significant voltage deviations due to unbalanced loading of the three-phase low voltage grid. The different phases influence each other in unbalanced situations, through the common neutral conductor. These effects can already occur at low market penetration levels, due to the presence of local penetration levels being significantly higher than the average market level. For a significant amount of e-cars and high power charging (up to 22 kW in Germany) after 2020 the main concerns of investigation will be the forecasting of the requested charging power, the location of this demand and the impact on power grid operation security without active grid control (e.g. voltage, asset overloading). On the low-voltage grid Further, a full integration of renewable generation is also important as the amount of thermal power plants decrease, because they currently balance the intermittent, renewable generation. The future integration of e-cars into the power grid and the coordinated operation/charging with renewable energies (mobile electricity storage) will be one of the most important challenges. The conflict between mobility and the availability of storage capacity in contrast to the generation will be discussed and some recommendations based on the modeling and simulations will be presented in the paper, too.
2012
Authors
Silva, ML; Ferreira, JC;
Publication
MICROPROCESSORS AND MICROSYSTEMS
Abstract
Instructions for concurrent processing of smaller data units than whole CPU words are useful in areas like multimedia processing and cryptography. Since the processors used in FPGA-based embedded systems lack support for such applications, this paper proposes mapping sequences of subword operations to a set of hardware components and generating the corresponding FPGA partial configurations at run-time. The technique is aimed at adaptive embedded systems that employ run-time reconfiguration to achieve high flexibility and performance. New partial configurations for circuits implementing sets of subword operations are created by merging together the relocated partial configurations of the hardware components (from a predefined library), and the configurations of the switch matrices used for the connections between the components. The paper presents and discusses results obtained for a 300 MHz PowerPC CPU in a Virtex-II Pro platform FPGA. For the set of benchmarks analyzed, the complete configuration creation process takes between 1 s and 24 s. The run-time generated hardware versions achieve speed-ups between 11 and 73 over the software versions.
2012
Authors
Javadi, MS; Nezhad, AE; Sabramooz, S;
Publication
Sci. Iran.
Abstract
2012
Authors
Cardoso, JMP; Carvalho, T; Coutinho, JGF; Luk, W; Nobre, R; Diniz, PC; Petrov, Z;
Publication
AOSD'12 - Proceedings of the 11th Annual International Conference on Aspect Oriented Software Development
Abstract
The development of applications for high-performance embedded systems is typically a long and error-prone process. In addition to the required functions, developers must consider various and often conflicting non-functional application requirements such as performance and energy efficiency. The complexity of this process is exacerbated by the multitude of target architectures and the associated retargetable mapping tools. This paper introduces an Aspect-Oriented Programming (AOP) approach that conveys domain knowledge and non-functional requirements to optimizers and mapping tools. We describe a novel AOP language, LARA, which allows the specification of compilation strategies to enable efficient generation of software code and hardware cores for alternative target architectures. We illustrate the use of LARA for code instrumentation and analysis, and for guiding the application of compiler and hardware synthesis optimizations. An important LARA feature is its capability to deal with different join points, action models, and attributes, and to generate an aspect intermediate representation. We present examples of our aspect-oriented hardware/software design flow for mapping real-life application codes to embedded platforms based on Field Programmable Gate Array (FPGA) technology. © 2012 ACM.
2012
Authors
Silva, ST; Valente, JMS; Teixeira, AAC;
Publication
JOURNAL OF ECONOMIC INTERACTION AND COORDINATION
Abstract
By combining features from distinct theoretical approaches, namely the evolutionary and the job search, matching and bargaining literatures, we propose a model that captures the main dynamics of a world where heterogeneous firms and workers interact and co-evolve. Within a micro-meso framework, the model focuses on the influence of firms' labour choices ("institutional settings") on industry dynamics, taking into account the existence of employment adjustment costs. The consideration of endogenous matching and bargaining processes in the labour market results in significant frictions, such as the simultaneous coexistence of unfilled job vacancies and unemployment. In a setting where technological progress is not biased a stylized fact of industrialized world economies in the last few decades emerges, the increasing wage inequality. Additionally, turbulence in the industry increases after a negative demand shock. As expected, the negative demand shock causes a decrease in the number of vacancies and, consequently, unemployment rates increase considerably. Interestingly, and mimicking the recent experiences of countries such as US, Spain, Greece and Portugal, the rise in unemployment is matched by a rise in contractual wages. This outcome is explained by the lower ability of the firms to fill their posted vacancies, which results from friction in the interactions among agents.
2012
Authors
Bourke, AK; Prescher, S; Koehler, F; Cionca, V; Tavares, C; Gomis, S; Garcia, V; Nelson, J;
Publication
2012 ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY (EMBC)
Abstract
With the rapidly increasing over 60 and over 80 age groups in society, greater emphasis will be put on technology to detect emergency situations, such as falls, in order to promote independent living. This paper describes the development and deployment of fall-detection, activity classification and energy expenditure algorithms, deployed in a tele-monitoring system. These algorithms were successfully tested in an end-user trial involving 9 elderly volunteers using the system for 28 days.
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