in Proceedings of the third International Symposium on Communications, Control and Signal Processing (ISCCSP
01 Jan 2008-
About: The article was published on 2008-01-01 and is currently open access. It has received 6 citations till now. The article focuses on the topics: Signal processing.
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01 Jan 2007
TL;DR: In this paper, two models are proposed to describe diffusion flame extinction due to air vitiation and the emission of carbon monoxide (CO) and unburnt hydrocarbon (HC) mass in a compartment fire.
Abstract: The general objective of this research is to adapt current combustion modeling capabilities used in computational fluid dynamics solvers to the treatment of under-ventilated compartment fires. More specifically, we consider in the present study two models proposed to describe: diffusion flame extinction due to air vitiation; and the emission of carbon monoxide (CO) and unburnt hydrocarbon (HC) mass in a compartment fire. The flame extinction model is based on a flammability diagram parametrized in terms of vitiated air properties. The CO/HC mass model is based on: a transport equation for fuel mass; a comparison of this fuel mass to a Burke–Schumann chemical-equilibrium expression; and an interpretation of the difference as a measure of incomplete combustion. Both models are implemented into a large eddy simulation solver developed by the National Institute of Standards and Technology, USA. The models performance is tested via detailed comparisons with an experimental database corresponding to reduced-scale compartment fires. The study considers two cases that correspond to different values of the fire room global equivalence ratio and are representative of strikingly different flame behaviors. The comparative tests serve to evaluate the general ability of the models to describe the transition from extinction-free conditions to conditions in which the flame experiences partial or total quenching, as well as the transition from fire regimes with no or little CO emission to regimes that emit hazardous levels.
38 citations
Cites background from "in Proceedings of the third Interna..."
...The lower oxygen index is also described as an empirical input quantity and is specified as Y O2 ;c 0:17 (mass fraction) [11,12]....
[...]
...Typical values of the lower oxygen index are 10–15% and depend on fuel type [11,12]....
[...]
TL;DR: In this paper, the angular distributions of tritons are measured for about 200 excitations seen in the triton spectra up to 3.3 MeV, with assignments for four states relatively firm and another four tentative.
Abstract: The excitation spectra in the deformed nucleus {sup 230}Th were studied by means of the (p,t) reaction, using the Q3D spectrograph facility at the Munich Tandem accelerator. The angular distributions of tritons are measured for about 200 excitations seen in the triton spectra up to 3.3 MeV. Firm 0{sup +} assignments are made for 16 excited states by comparison of experimental angular distributions with the calculated ones using the CHUCK code. Additional assignments are possible, with assignments for four states relatively firm and another four tentative. Assignments up to spin 6{sup +} are made for other states. Sequences of the states are selected that can be treated as rotational bands and as multiplets of excitations. Experimental data are compared with interacting boson model (IBM) and quasiparticle-phonon model (QPM) calculations.
18 citations
TL;DR: In this paper, the electronic and structural properties of two conformations including conjugated compounds of fluorene 1,3,4 thiadiazole and the electron acceptor [6,6]-phenyl C61-butyric acid methyl ester or PCBM, (PCBM/TDA10FL) were calculated using density functional theory to assess their possible application as organic semiconductor materials in photovoltaic devices.
4 citations
Cites background from "in Proceedings of the third Interna..."
...This behavior is due to the two electron acceptor imine groups presented in the thiadiazole unit [23]....
[...]
TL;DR: In this paper, the authors make the case that recent results in real-time model predictive control, where optimization problems are solved in order to control a process that evolves in time, are likely to form the basis of scheduling algorithms of the future.
Abstract: The performance, reliability, cost, size and energy usage of computing systems can be improved by one or more orders of magnitude by the systematic use of modern control and optimization methods. Computing systems rely on the use of feedback algorithms to schedule tasks, data and resources, but the models that are used to design these algorithms are validated using open-loop metrics. By using closed-loop metrics instead, such as the gap metric developed in the control community, it should be possible to develop improved scheduling algorithms and computing systems that have not been over-engineered. Furthermore, scheduling problems are most naturally formulated as constraint satisfaction or mathematical optimization problems, but these are seldom implemented using state of the art numerical methods, nor do they explicitly take into account the fact that the scheduling problem itself takes time to solve. This paper makes the case that recent results in real-time model predictive control, where optimization problems are solved in order to control a process that evolves in time, are likely to form the basis of scheduling algorithms of the future. We therefore outline some of the research problems and opportunities that could arise by explicitly considering feedback and time when designing optimal scheduling algorithms for computing systems.
4 citations
01 Dec 2012
TL;DR: In this paper, a simple reaction mechanism, such as sequential decay from inelastic excitation, was investigated more carefully as a possible explanation of the observed phenomenon, which is a process which is observed in several (p, p ) knockout studies.
Abstract: Nucleon-induced inclusive reactions at incident energies in the 100 to 200 MeV range, in which light composite particles are emitted, are of special interest. For emission of -particles into the continuum, it appears that the yield is enhanced towards lower outgoing energies of the ejectile compared with the value predicted by a multistep model. We postulate that a simple reaction mechanism, such as sequential decay from inelastic excitation, should be investigated more carefully as a possible explanation of the observed phenomenon. The motivation for this is that the suggested mechanism is a process which is observed in several (p; p ) knockout studies.
3 citations
References
More filters
01 Jan 2007
TL;DR: In this paper, two models are proposed to describe diffusion flame extinction due to air vitiation and the emission of carbon monoxide (CO) and unburnt hydrocarbon (HC) mass in a compartment fire.
Abstract: The general objective of this research is to adapt current combustion modeling capabilities used in computational fluid dynamics solvers to the treatment of under-ventilated compartment fires. More specifically, we consider in the present study two models proposed to describe: diffusion flame extinction due to air vitiation; and the emission of carbon monoxide (CO) and unburnt hydrocarbon (HC) mass in a compartment fire. The flame extinction model is based on a flammability diagram parametrized in terms of vitiated air properties. The CO/HC mass model is based on: a transport equation for fuel mass; a comparison of this fuel mass to a Burke–Schumann chemical-equilibrium expression; and an interpretation of the difference as a measure of incomplete combustion. Both models are implemented into a large eddy simulation solver developed by the National Institute of Standards and Technology, USA. The models performance is tested via detailed comparisons with an experimental database corresponding to reduced-scale compartment fires. The study considers two cases that correspond to different values of the fire room global equivalence ratio and are representative of strikingly different flame behaviors. The comparative tests serve to evaluate the general ability of the models to describe the transition from extinction-free conditions to conditions in which the flame experiences partial or total quenching, as well as the transition from fire regimes with no or little CO emission to regimes that emit hazardous levels.
38 citations
TL;DR: In this paper, the angular distributions of tritons are measured for about 200 excitations seen in the triton spectra up to 3.3 MeV, with assignments for four states relatively firm and another four tentative.
Abstract: The excitation spectra in the deformed nucleus {sup 230}Th were studied by means of the (p,t) reaction, using the Q3D spectrograph facility at the Munich Tandem accelerator. The angular distributions of tritons are measured for about 200 excitations seen in the triton spectra up to 3.3 MeV. Firm 0{sup +} assignments are made for 16 excited states by comparison of experimental angular distributions with the calculated ones using the CHUCK code. Additional assignments are possible, with assignments for four states relatively firm and another four tentative. Assignments up to spin 6{sup +} are made for other states. Sequences of the states are selected that can be treated as rotational bands and as multiplets of excitations. Experimental data are compared with interacting boson model (IBM) and quasiparticle-phonon model (QPM) calculations.
18 citations
TL;DR: This paper makes the case that recent results in real-time model predictive control, where optimization problems are solved in order to control a process that evolves in time, are likely to form the basis of scheduling algorithms of the future.
7 citations
TL;DR: In this paper, the electronic and structural properties of two conformations including conjugated compounds of fluorene 1,3,4 thiadiazole and the electron acceptor [6,6]-phenyl C61-butyric acid methyl ester or PCBM, (PCBM/TDA10FL) were calculated using density functional theory to assess their possible application as organic semiconductor materials in photovoltaic devices.
4 citations
01 Dec 2012
TL;DR: In this paper, a simple reaction mechanism, such as sequential decay from inelastic excitation, was investigated more carefully as a possible explanation of the observed phenomenon, which is a process which is observed in several (p, p ) knockout studies.
Abstract: Nucleon-induced inclusive reactions at incident energies in the 100 to 200 MeV range, in which light composite particles are emitted, are of special interest. For emission of -particles into the continuum, it appears that the yield is enhanced towards lower outgoing energies of the ejectile compared with the value predicted by a multistep model. We postulate that a simple reaction mechanism, such as sequential decay from inelastic excitation, should be investigated more carefully as a possible explanation of the observed phenomenon. The motivation for this is that the suggested mechanism is a process which is observed in several (p; p ) knockout studies.
3 citations