Companies regularly face the challenge of deciding whether, when and to which extent they should invest in information technology (IT) innovations with different maturity. The IT innovation strategy thereby should con...
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Companies regularly face the challenge of deciding whether, when and to which extent they should invest in information technology (IT) innovations with different maturity. The IT innovation strategy thereby should consider mature as well as fashionable IT innovations as investment alternatives. As previous research's focus is rather qualitative, we develop a dynamic optimisation model that determines the optimal strategic allocation of an IT innovation budget to mature and fashionable IT innovations. Using a simulation-based approach, we analyse the essential causal relationships between the theoretical optimum and the factors of major influence. We find that companies should invest in fashionable IT innovations even if their own level of innovativeness is rather low and the technology's success probability has not reached a high threshold yet. Our findings provide a basis for further research on mindful investment decisions in fashionable IT innovations.
A compact operations research (OR) model is proposed to analyse the prospects of meeting the Paris Agreement targets when direct air capture technologies can be used or not. The main features of the OR model are (i) t...
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A compact operations research (OR) model is proposed to analyse the prospects of meeting the Paris Agreement targets when direct air capture technologies can be used or not. The main features of the OR model are (i) the representation of the economy and energy use with a nested constant elasticity of substitution production function;(ii) the representation of climate policy through the use of a safety emissions budget concept;and (iii) the representation of an international emissions trading scheme for the implementation of climate policy. Using dynamicoptimisation, several contrasting scenarios are analysed and the potential use of the model in future developments of climate/economy modelling is discussed. (c) 2022 Elsevier B.V. All rights reserved.
The authors investigate the adaptive resource allocation problem for cognitive power line communication system. The dynamic optimisation model is employed to maximise the energy-aware network utility, which is defined...
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The authors investigate the adaptive resource allocation problem for cognitive power line communication system. The dynamic optimisation model is employed to maximise the energy-aware network utility, which is defined as the difference of the weighted network throughput and the power consumption. Then, the authors decompose the stochastic optimisation into a traffic management subproblem and a joint subchannel and power allocation subproblem. Since the joint subchannel and power allocation subproblem is a mixed integer non-linear optimisation, a continuity relaxation and Lagrange dual method is proposed to obtain the optimal solution of the mixed integer non-linear optimisation subproblem. After that, the authors develop an adaptive power line communication resource allocation algorithm to cope with the power line communication network dynamics only according to the current network state information. Finally, we derive a trade-off mechanism between network utility and network delay, in which the network delay is proportional to the control parameter V and the network utility is proportional to the parameter 1/V$1/V$. Simulation results not only show the effectiveness but also verify the theoretical analysis of our proposed algorithm.
Acclimation patterns in kinetic coefficients clearly demonstrate the limits of Monod's theory for the mathematical description of microbial growth. Focusing on E. coli grown under variable glucose levels, these pa...
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Acclimation patterns in kinetic coefficients clearly demonstrate the limits of Monod's theory for the mathematical description of microbial growth. Focusing on E. coli grown under variable glucose levels, these patterns turn out to be highly diverse and sometimes even contradictory. Here, a new model based on an optimisation assumption is applied to a spectrum of adaptation phenomena, which are observed at steady-state as well as during transient situations. On the level of apparent kinetic coefficients, rates of adaptation are calculated depending on differential growth benefits. The resulting dynamics is bounded since maximum growth rate and substrate affinity are related by a non-linear trade-off. Long-term effects of phenotypic and genotypic changes under glucose limitation are robustly predicted by the model and explained in terms of their adaptive significance. Equivocal short-term recovery patterns occurring after sudden substrate excess are traced back to differences in the internal physiological state of the cells which in turn can be calculated in dependence on the inoculum history. Metabolic stress is a second determinant of short-term variations in kinetic coefficients which is here quantified in relation to external conditions as well as the internal state of cells. We demonstrate that lag phenomena and oscillations in anabolic activity exercised by E. coli under continuous growth acceleration can be reproduced without formulations being explicit in lag periods, metabolite concentrations or the timing of experimental changes. The overall predictive power of the simple approach indicates that slow as well as fast adjustments in apparent kinetic characteristics are strongly related to a dynamicoptimisation strategy. (C) 2002 Elsevier Science B.V. All rights reserved.
Land application of wastewater provides an alternative for wastewater deposition which can be both environmentally sound and economically viable. Effluent from the wastewater system of the city of Lubbock, Texas, USA ...
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Land application of wastewater provides an alternative for wastewater deposition which can be both environmentally sound and economically viable. Effluent from the wastewater system of the city of Lubbock, Texas, USA was used for crop irrigation as a study case. A dynamic optimization model was developed to determine the optimal cropping system that would utilize all the effluent supplied, remove all hazardous materials from the effluent, and maximize crop net revenues. The results indicate that the optimal crop composition contains alfalfa, wheat-corn, wheat-grain sorghum, and cotton. The study also reveals that increases of cropland area and effluent volume could increase municipal revenues.
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