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Ioannis M. THOIDIS Dimitrios SOUDRIS Adonios THANAILAKIS
Novel designs of multiple-valued logic (quaternary) half adder, full adder, and carry-lookahead adder are introduced. The proposed circuits are static and operate in voltage-mode. Moreover, there is no current flow in steady states, and thus, no static power dissipation. Although the comparison in transistor count shows that the proposed quaternary circuits are larger than two respective binary ones, benefits in parallel addition arise from the use of multiple-valued logic. Firstly, the ripple-carry additions are faster because the number of carries is half compared to binary ones and the propagation delay from the input carry through the output carry is relatively small. Secondly, the carry-lookahead scheme exhibits less complexity, which leads to overall reduction in transistor count for addition with large number of bits.
Daichi WATARI Ittetsu TANIGUCHI Francky CATTHOOR Charalampos MARANTOS Kostas SIOZIOS Elham SHIRAZI Dimitrios SOUDRIS Takao ONOYE
Energy management in buildings is vital for reducing electricity costs and maximizing the comfort of occupants. Excess solar generation can be used by combining a battery storage system and a heating, ventilation, and air-conditioning (HVAC) system so that occupants feel comfortable. Despite several studies on the scheduling of appliances, batteries, and HVAC, comprehensive and time scalable approaches are required that integrate such predictive information as renewable generation and thermal comfort. In this paper, we propose an thermal-comfort aware online co-scheduling framework that incorporates optimal energy scheduling and a prediction model of PV generation and thermal comfort with the model predictive control (MPC) approach. We introduce a photovoltaic (PV) energy nowcasting and thermal-comfort-estimation model that provides useful information for optimization. The energy management problem is formulated as three coordinated optimization problems that cover fast and slow time-scales by considering predicted information. This approach reduces the time complexity without a significant negative impact on the result's global nature and its quality. Experimental results show that our proposed framework achieves optimal energy management that takes into account the trade-off between electricity expenses and thermal comfort. Our sensitivity analysis indicates that introducing a battery significantly improves the trade-off relationship.
Christos DROSOS Chrissavgi DRE Spyridon BLIONAS Dimitrios SOUDRIS
The architecture and implementation of a novel processor suitable wireless terminal applications, is introduced. The wireless terminal is based on the novel dual-mode baseband processor for DECT and GSM, which supports both heterodyne and direct conversion terminal architectures and is capable to undertake all baseband signal processing, and an innovative direct conversion low power modulator/demodulator for DECT and GSM. The state of the art design methodologies for embedded applications and innovative low-power design steps followed for a single chip solution. The performance of the implemented dual mode direct conversion wireless terminal was tested and measured for compliance to the standards. The developed innovative terminal fulfils all the requirements and specifications imposed by the DECT and GSM standards.
Konstantinos SIOZIOS George KOUTROUMPEZIS Konstantinos TATAS Nikolaos VASSILIADIS Vasilios KALENTERIDIS Haroula POURNARA Ilias PAPPAS Dimitrios SOUDRIS Antonios THANAILAKIS Spiridon NIKOLAIDIS Stilianos SISKOS
A complete system for the implementation of digital logic in a Field-Programmable Gate Array (FPGA) platform is introduced. The novel power-efficient FPGA architecture was designed and simulated in STM 0.18 µm CMOS technology. The detailed design and circuit characteristics of the Configurable Logic Block, the interconnection network, the switch box and the connection box were determined and evaluated in terms of energy, delay and area. A number of circuit-level low-power techniques were employed because power consumption was the primary concern. Additionally, a complete tool framework for the implementation of digital logic circuits in FPGA platforms is introduced. Having as input VHDL description of an application, the framework derives the reconfiguration bitstream of FPGA. The framework consists of: i) non-modified academic tools, ii) modified academic tools and iii) new tools. Furthermore, the framework can support a variety of FPGA architectures. Qualitative and quantitative comparisons with existing academic and commercial architectures and tools are provided, yielding promising results.