Browsing by Subject "EQUILIBRIUM"

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  • Korpela, Ville; Lombardi, Michele; Vartiainen, Hannu (2020)
    In this paper, we re-examine the classical questions of implementation theory under complete information in a setting where coalitions are fundamental behavioral units, and the outcomes of their interactions are predicted by applying the solution concept of the core. The planner's exercise includes designing a code of rights that specifies the collection of coalitions having the right to block one outcome by moving to another. A code of individual rights is a code of rights in which only unit coalitions may have blocking powers. We provide the necessary and sufficient conditions for implementation (under core equilibria) by codes of rights, as well as by codes of individual rights. We also show that these two modes of implementation are not equivalent. The results are robust and extend to alternative notions of core, such as an externally stable core. Therefore, coalitions are shown to bring value added to institutional design. The characterization results address the limitations that restrict the relevance of the existing implementation theory. (C) 2019 Elsevier Inc. All rights reserved.
  • Annala, Eemeli; Ecker, Christian; Hoyos, Carlos; Jokela, Niko; Rodriguez Fernandez, David; Vuorinen, Aleksi (2018)
    We investigate a simple holographic model for cold and dense deconfined QCD matter consisting of three quark flavors. Varying the single free parameter of the model and utilizing a Chiral Effective Theory equation of state (EoS) for nuclear matter, we find four different compact star solutions: traditional neutron stars, strange quark stars, as well as two non-standard solutions we refer to as hybrid stars of the second and third kind (HS2 and HS3). The HS2s are composed of a nuclear matter core and a crust made of stable strange quark matter, while the HS3s have both a quark mantle and a nuclear crust on top of a nuclear matter core. For all types of stars constructed, we determine not only their mass-radius relations, but also tidal deformabilities, Love numbers, as well as moments of inertia and the mass distribution. We find that there exists a range of parameter values in our model, for which the novel hybrid stars have properties in very good agreement with all existing bounds on the stationary properties of compact stars. In particular, the tidal deformabilities of these solutions are smaller than those of ordinary neutron stars of the same mass, implying that they provide an excellent fit to the recent gravitational wave data GW170817 of LIGO and Virgo. The assumptions underlying the viability of the different star types, in particular those corresponding to absolutely stable quark matter, are finally discussed at some length.
  • Korpela, Ville; Lombardi, Michele; Vartiainen, Hannu (2021)
    The designer's exercise consists of designing a rights structure that formalizes the idea of power distribution in society. A solution is implementable in largest consistent set by a rights structure if there exists a rights structure such that for each preference profile, the largest consistent set of the game played by agents coincides with the set of outcomes that the solution would select for it. In a setting with transfers, every Maskin monotonic solution is implementable. This finding implies that the class of implementable solutions in core equilibria is unaltered by farsighted reasoning. (C) 2021 The Author(s). Published by Elsevier Inc.
  • Lumiaro, Emma; Todorović, Milica; Kurten, Theo; Vehkamäki, Hanna; Rinke, Patrick (2021)
    The formation, properties, and lifetime of secondary organic aerosols in the atmosphere are largely determined by gas-particle partitioning coefficients of the participating organic vapours. Since these coefficients are often difficult to measure and to compute, we developed a machine learning model to predict them given molecular structure as input. Our data-driven approach is based on the dataset by Wang et al. (2017), who computed the partitioning coefficients and saturation vapour pressures of 3414 atmospheric oxidation products from the Master Chemical Mechanism using the COSMOtherm programme. We trained a kernel ridge regression (KRR) machine learning model on the saturation vapour pressure (P-sat) and on two equilibrium partitioning coefficients: between a water-insoluble organic matter phase and the gas phase (K-WIOM/G) and between an infinitely dilute solution with pure water and the gas phase (K-W/G). For the input representation of the atomic structure of each organic molecule to the machine, we tested different descriptors. We find that the many-body tensor representation (MBTR) works best for our application, but the topological fingerprint (TopFP) approach is almost as good and computationally cheaper to evaluate. Our best machine learning model (KRR with a Gaussian kernel + MBTR) predicts P-sat and K-WIOM/G to within 0.3 logarithmic units and K-W/G to within 0.4 logarithmic units of the original COSMOtherm calculations. This is equal to or better than the typical accuracy of COSMOtherm predictions compared to experimental data (where available). We then applied our machine learning model to a dataset of 35 383 molecules that we generated based on a carbon-10 backbone functionalized with zero to six carboxyl, carbonyl, or hydroxyl groups to evaluate its performance for polyfunctional compounds with potentially low P-sat. The resulting saturation vapour pressure and partitioning coefficient distributions were physico-chemically reasonable, for example, in terms of the average effects of the addition of single functional groups. The volatility predictions for the most highly oxidized compounds were in qualitative agreement with experimentally inferred volatilities of, for example, alpha-pinene oxidation products with as yet unknown structures but similar elemental compositions.
  • Rahman, Md Wasikur; Nipa, Sumaya Tarannum; Rima, Sarmin Zaman; Hasan, Md Mahmudul; Saha, Raghunath; Halim, Md Abdul; Ali, Yousuf; Deb, Anjan (2022)
    In this work, pseudo-stem banana (Musa acuminata) (PBF) fiber was utilized as a potential low-cost natural adsorbent to uptake methylene blue (MB) dye from synthetic wastewater by batch adsorption process. Different adsorption factors like contact time, pH, initial concentration, and adsorbent dosage were explored and found that the separation process is strongly pH dependent. Additionally, the adsorption data were fitted with various adsorption isotherms like Langmuir, Freundlich, Temkin, and Dubinin-Radhushkevich models to detect the adsorption equilibrium phenomena. Reaction kinetics was inspected using pseudo-first-order and second-order kinetic models. Mass transfer and intra-particle diffusion analyses indicate the adsorption mechanism of the system described particularly in the context. Furthermore, scanning electron spectroscopy (SEM) and Fourier transformed infrared spectroscopy (FTIR) were conducted to get the morphology and surface properties of the adsorbent, respectively. As a result, the as-prepared banana fiber can be proposed as a cheap suitable adsorbent to separate dyestuffs from industrial wastewater.
  • Friman, Aino; Hyytia, Nina (2022)
    Food waste is economically and ecologically unsustainable; the benefits of food waste reduction are indisputable. Yet knowledge of the economic trade-offs and knock-on effects of such reduction is deficient. This study examines the economic effects of food waste reduction in a rural region that is a nationally important producer of agricultural and food products in Finland. We built a detailed social accounting matrix to trace the transactions among the economic agents. Five different simulations of food waste reduction were run by applying a computable general equilibrium model. In the simulations, households and food services halved their food waste. The results indicated that food waste reduction is economically worthwhile in terms of regional investments and gross domestic product at market prices. However, the reduction induced economic trade-offs and welfare redistribution. The value added to the agriculture and food industries and the welfare of agricultural households decreased, albeit that the simulated compensations alleviated the effects. In the long run, falling agricultural wages and factor incomes entail closedowns and, finally, decrease local food production. This aspect is worth considering in terms of policy planning under the principle of just transition of the European Green Deal.