scholarly journals Hybrid Deduction-Refutation Systems for FDE-Based Logics

2021 ◽  
Vol 18 (6) ◽  
pp. 599-615
Author(s):  
Eoin Moore

Hybrid deduction-refuation systems are presented for four first-degree entailment based logics. The hybrid systems are shown to be deductively and refutationally sound with respect to their logics. The proofs of completeness are presented in a uniform way. The paper builds on work by Goranko, who presented a deductively and refutationally sound and complete hybrid system for classical logic.

Author(s):  
Wulf Loh ◽  
Janina Loh

In this chapter, we give a brief overview of the traditional notion of responsibility and introduce a concept of distributed responsibility within a responsibility network of engineers, driver, and autonomous driving system. In order to evaluate this concept, we explore the notion of man–machine hybrid systems with regard to self-driving cars and conclude that the unit comprising the car and the operator/driver consists of such a hybrid system that can assume a shared responsibility different from the responsibility of other actors in the responsibility network. Discussing certain moral dilemma situations that are structured much like trolley cases, we deduce that as long as there is something like a driver in autonomous cars as part of the hybrid system, she will have to bear the responsibility for making the morally relevant decisions that are not covered by traffic rules.


2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Paul Kröger ◽  
Martin Fränzle

Abstract Hybrid system dynamics arises when discrete actions meet continuous behaviour due to physical processes and continuous control. A natural domain of such systems are emerging smart technologies which add elements of intelligence, co-operation, and adaptivity to physical entities. Various flavours of hybrid automata have been suggested as a means to formally analyse dynamics of such systems. In this article, we present our current work on a revised formal model that is able to represent state tracking and estimation in hybrid systems and thereby enhancing precision of verification verdicts.


2009 ◽  
Author(s):  
W. J. Sembler ◽  
S. Kumar

The reduction of shipboard airborne emissions has been receiving increased attention due to the desire to improve air quality and reduce the generation of greenhouse gases. The use of a fuel cell could represent an environmentally friendly way for a ship to generate in-port electrical power that would eliminate the need to operate diesel-driven generators or use shore power. This paper includes a brief description of the various types of fuel cells in use today, together with a review of the history of fuel cells in marine applications. In addition, the results of a feasibility study conducted to evaluate the use of a fuel-cell hybrid system to produce shipboard electrical power are presented.


Author(s):  
Abdellah Benallal ◽  
◽  
Nawel Cheggaga ◽  

Renewable energy hybrid systems give a good solution in isolated sites, in the Algerian desert; wind and solar potentials are considerably perfect for a combination in a renewable energy hybrid system to satisfy local village electrical load and minimize the storage requirements, which leads to reduce the cost of the installation. For a good sizing, it is essential to know accurately the solar potential of the installation area also wind potential at the same height where wind electric generators will be placed. In this work, we optimize a completely autonomous PV-wind hybrid system and show the techno-economical effects of the height of the wind turbine on the sizing of the hybrid system. We also compare the simulation results obtained from using wind speed measured data at 10 meters and 40 meters of height with the ones obtained from using wind speed extrapolation on HOMER software.


2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Aiping Jiang ◽  
Zhenni Huang ◽  
Jiahui Xu ◽  
Xuemin Xu

PurposeThe purpose of this paper is to propose a condition-based opportunistic maintenance policy considering economic dependence for a series–parallel hybrid system with a K-out-of-N redundant structure, where a single component in series is denoted as subsystem1, and K-out-of-N redundant structure is denoted as subsystem2.Design/methodology/approachBased on the theory of Residual Useful Life (RUL), inspection points are determined, and then different maintenance actions are adopted in the purpose of minimizing the cost rate. Both perfect and imperfect maintenance actions are carried out for subsystem1. More significantly, regarding economic dependence, condition-based opportunistic maintenance is designed for the series–parallel hybrid system: preemptive maintenance for subsystem1, and both preemptive and postponed maintenance for subsystem2.FindingsThe sensitivity analysis indicates that the proposed policy outperforms two classical maintenance policies, incurring the lowest total cost rate under the context of both heterogeneous and quasi-homogeneous K-out-of-N subsystems.Practical implicationsThis model can be applied in series–parallel systems with redundant structures that are widely used in power transmission systems in electric power plants, manufacturing systems in textile factories and sewerage systems. Considering inconvenience and high cost incurred in the inspection of hybrid systems, this model helps production managers better maintain these systems.Originality/valueIn maintenance literature, much attention has been received in repairing strategies on hybrid systems with economic dependence considering preemptive maintenance. Limited work has considered postponed maintenance. However, this paper uses both condition-based preemptive and postponed maintenance on the issue of economic dependence bringing opportunities for grouping maintenance activities for a series–parallel hybrid system.


Author(s):  
Alireza Gheiratmand ◽  
Reza Effatnejad ◽  
Mahdi Hedayati

Incremental consumption of electrical energy, reduction of fossil fuel resources and environmental pollution problems caused by them are the main reasons, which tend the managers and officials in countries energy sector to develop use of renewable systems. In the not-too-distant future the use of renewable energy such as wind and solar will be very important and will play predominant role in economic indices of power systems. In recent years, technological advances in renewable energy and increasing price of petroleum products promote system managers to use low-cost and low-emission energy resources in form of hybrid systems and widespread propagation of electricity generation have been developed in remote areas. In Hybrid systems two or more sources of renewable energy is typically adopted, which increases the reliability of these systems. In this paper, the technical and economical consideration of a wind and solar hybrid system to supply electrical energy for a number of remote users (aid and medical emergency Shelter in Yazd) is provided. In order to investigate optimization and economic analysis of the proposed hybrid system, the HOMER software is used.  The results of Simulation in HOMER software show that Solar cells and wind systems with average generation power of 896 kWh/yr. and 343 kWh/yr., consist proportion of 72 and 28 percent of the total generated energy respectively, which are dedicated to satisfy the loads


Author(s):  
A. Franzoni ◽  
L. Magistri ◽  
O. Tarnowsky ◽  
A. F. Massardo

This paper investigates options for highly efficient SOFC hybrid systems of different sizes. For this purpose different models of pressurised SOFC hybrids systems have been developed in the framework of the European Project “LARGE SOFC - Towards a Large SOFC Power Plant”. This project, coordinated by VTT Finland, counts numerous industrial partners such as Wartsila, Topsoe and Rolls-Royce FCS ltd. Starting from the RRFCS Hybrid System [1], considered as the reference case, several plant modifications have been investigated in order to improve the thermodynamic efficiency. The main options considered are (i) the integration of a recuperated micro gas turbine and (ii) the replacement of the cathodic ejector with a blower. The plant layouts are analysed in order to define the optimum solution in terms of operating parameters and thermodynamic performances. The study of a large size power plant (around 110 MWe) fed by coal and incorporated with SOFC hybrid systems is also conducted. The aim of this study is to analyse the sustainability of an Integrated Gasification Hybrid System from the thermodynamic and economic point of view in the frame of future large sized power generation. A complete thermoeconomic analysis of the most promising plants is carried out, taking into account variable and capital costs of the systems. The designed systems are compared from the thermodynamic and the thermoeconomic point of view with some of the common technologies used for distributed generation (gas turbines and reciprocating engines) and large size power generation (combined cycles and IGCC). The tool used for this analysis is WTEMP software, developed by the University of Genoa (DIMSET-TPG) [2], able to carry out a detailed thermodynamic and thermoeconomic analysis of the whole plants.


2014 ◽  
Vol 643 ◽  
pp. 90-95
Author(s):  
Shu Rong Sun ◽  
Wei Song Chen ◽  
Yan Zhao ◽  
Zhen Lai Han

In this paper, we study the strict practical stability for the discrete hybrid systems in terms of two measures. Using Lyapunov-like functions, we obtain some comparison theorems first and then by them get a sufficient condition on the strict practical stability of the hybrid system.


Author(s):  
Sung Ho Park ◽  
Young Duk Lee ◽  
Sang Gyu Kang ◽  
Kook Young Ahn

Fuel cell systems are currently regarded as a promising type of energy conversion system. Various types of fuel cell have been developed and investigated worldwide for portable, automotive, and stationary applications. In particular, in the case of large-scale stationary applications, the high-temperature fuel cells known as the molten carbonate fuel cell (MCFC) and the solid oxide fuel cell (SOFC) have been used as a power source due to their higher efficiency compared to low-temperature fuel cells. Because SOFCs have many advantages, including a high power density, low corrosion, and operability without a metal catalyst, many efforts to develop a SOFC hybrid system have been undertaken. SOFC hybrid systems with a gas turbine or engine show improved system efficiency through their utilization of waste heat and unreacted fuel. Especially, the internal combustion engine has the advantage of robustness, easy maintenance, and a low cost compared to gas turbines, this type is more adaptable for use in a hybrid system with a SOFC. However, the engine should be operated stably at a high air fuel ratio because the SOFC anode exhaust gas has a low fuel concentration. The homogeneous charge compression ignition (HCCI) engine has both the advantages of SI and CI engines. Moreover, the lean burn characteristics of the HCCI engine make it a strong candidate for SOFC hybrid systems. The objective of this work is to develop a novel cycle composed of a SOFC and a HCCI engine. In order to optimize the SOFC-HCCI hybrid system, a system analysis is conducted here using the commercial software Aspen Plus®. The SOFC model is validated with experimental data. The engine model is developed based on an empirical equation that considers the ignition delay time. The performance of the hybrid system is compared with that of a SOFC stand-alone system to confirm the optimization of the system. This study will be useful for the development of a new type of hybrid system which uses a fuel cell and an optimized system.


2013 ◽  
Vol 437 ◽  
pp. 306-312 ◽  
Author(s):  
Jarosław Milewski ◽  
Marcin Wołowicz ◽  
Rafał Bernat ◽  
Lukasz Szablowski ◽  
Janusz Lewandowski

The paper presents a variant analysis of the structure of SOFC hybrid system. The systems are divided into two gropus: atmospheric and pressurized. The main parameter of such systems are indicated and commented. The comparison of various configurations is shown in a view of efficiency obtained. The ultra high efficiency (65% HHV, 72% LHV) of electricity production seems to be possible by systems like these.


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