1,720 research outputs found
Triple implementation by sharing mechanisms in production economics with unequal labor skill
labor sovereignty, triple implementation, different labor skills
Nash Implementation in Production Economies with Unequal Skills: A Complete Characterization
In production economies with unequal labor skills, where the planner is ignorant to the set of feasible allocations in advance of production, the paper firstly introduces a new axiom, Nonmanipulability of Irrelevant Skills (NIS), which together with Maskin Monotonicity constitute the necessary and sufficient conditions for Nash implementation. Secondly, the paper defines natural mechanisms, and then fully characterizes Nash implementation by natural mechanisms, using a slightly stronger variation of NIS and Supporting Price Independence. Following these characterizations, it is shown that there is a Maskin monotonic allocation rule which is not implementable when information about individual skills is absent. In contrast, many fair allocation rules, which are known to be non-implementable in the present literature, are implementable by the natural mechanisms.Unequal labor skills, Nash implementation, Nonmanipulability of Irrelevant Skills
Nash Implementation in Production Economies with Unequal Skills : A Complete Characterization
In production economies with unequal labor skills, one of the intrinsic features for Nash implementation problems is the lack of information about individual skills, which makes the planner ignorant to the set of feasible allocations in advance of production. Given this intrinsic feature, the paper firstly introduces a new axiom, Non-manipulability of Irrelevant Skills (NIS), which together with Maskin Monotonicity constitute the necessary and sufficient conditions for Nash implementation. Secondly, the paper defines some conditions for natural mechanisms which seem relevant, and then shows that any efficient allocation rule is Nashimplementable by the natural mechanisms if and only if it satisfies a slightly stronger variation of NIS and Supporting Price Independence. Following these characterizations, it is shown that there is a Maskin monotonic allocation rule which is not implementable when information about individual skills is absent. In contrast, there are many fair allocation rules which are known to be non-implementable in the present literature, but are implementable by the natural mechanisms given in this paper.Unequal labor skills, Nash implementation, Nonmanipulability of Irrelevant Skills
Modified Laplace transformation method and its application to the anharmonic oscillator
We apply a recently proposed approximation method to the evaluation of
non-Gaussian integral and anharmonic oscillator. The method makes use of the
truncated perturbation series by recasting it via the modified Laplace integral
representation. The modification of the Laplace transformation is such that the
upper limit of integration is cut off and an extra term is added for the
compensation. For the non-Gaussian integral, we find that the perturbation
series can give accurate result and the obtained approximation converges to the
exact result in the limit ( denotes the order of perturbation
expansion). In the case of anharmonic oscillator, we show that several order
result yields good approximation of the ground state energy over the entire
parameter space. The large order aspect is also investigated for the anharmonic
oscillator.Comment: 26 pages including tables, Late
Guiding Center Derivation of the Generalized Hasegawa-Mima Equation for Drift Wave Turbulence in Curved Magnetic Fields
Recently, a generalized Hasegawa-Mima (gHM) equation describing drift wave
turbulence in curved magnetic fields has been derived in [N. Sato and M.
Yamada, J. Plasma Phys. (2022), vol. 88, 905880319] for an ion-electron plasma
modeled as a two-fluid system. In this work, we show that a mathematically
equivalent GHM equation can be obtained within the kinetic framework of guiding
center motion, and that the relevant drift wave turbulence ordering can be
further relaxed, effectively generalizing the applicability of the equation to
any magnetic field geometry and electron spatial density, in the sense that no
ordering requirements involve spatial derivatives of the magnetic field or the
electron spatial density.Comment: 13 pages, 5 table
Spray Combustion Chamber: History and Future of a Unique Test Facility
[EN] Large marine two-stroke diesel engines still represent the major propulsion system for merchant shipping. With
steadily increasing transport demands, rising operational costs and stricter environmental legislations, the global
marine shipping industry finds itself facing the challenge to future-proof its fleet. In order to comply with international
maritime organizations emission standards (TIER II and TIER III), highly sophisticated and flexible combustion
systems are demanded. With the help of spray and combustion research such systems can be developed and
continuously improved. A highly valuable tool to investigate sprays of large marine diesel injectors under engine
relevant conditions is the Spray Combustion Chamber (SCC). This paper reviews the history of the SCC, shows
todays possibilities and looks into the near future of research involving large marine two-stroke engines. The SCC
was built during the first Hercules project (I.P.-HERCULES, WP5, [1]). The initial setup focused on fundamental
investigations comprising the application of highly flexible thermodynamic conditions. During follow-up projects
(Hercules beta [2] and Hercules C [3]) the SCC was continuously developed, and a variety of influences on spray
and combustion were experimentally assessed. The initial SCC design focused on maximum optical access as well
as the applicability of a wide span of optical techniques. Single-hole nozzles were utilized to generate reference
data to optimize existing spray and combustion simulation models. Different fuel types and fuel qualities were
investigated and effects of the in-nozzle flow on spray morphology was identified. A sound set of results was
achieved and published in several (internal and public) reports. Over the years, spray research at Winterthur Gas
& Diesel has turned its focus from basic spray investigations to more detailed cavitation and in-nozzle flow
examinations [4], [5]. Future research on the SCC will focus on investigations of more engine related topics, as, for
example, the application of a fuel flexible injection system as is currently developed in the HERCULES-2 project
[6]. Significant design modifications of the initial setup were necessary, as the injector positions and therefore
exposure of the spray relative to the swirl were not fully congruent with real engine conditions. As a consequence,
the new setup includes some minor drawbacks, e.g. the optical access of the nozzle tip is only visible from one side
of the chamber. This means that line-of-sight methods are currently only possible at selected positions in the centre
of the chamber. Therefore, a new setup was installed to illuminate the spray, consisting of a high speed, high energy
laser (100 kHz, 100 W) and special optics. In order to obtain enhanced optical access, tangential windows were rearranged,
now pointing directly at the nozzle. With this setup, a first set of images was realized, showing a real
spray as it occurs in large marine two-stroke diesel engines.The installation of such a complex setup would not have been possible without the support of several partners over
the past years. The design, setup and continuous improvement of the SCC has been conducted within the
framework of different projects:
· I.P. HERCULES project within EC's 6th Framework Program: Contract TIP3-CT-2003-506676
· HERCULES-β project within EC's 7th Framework Program: Contract SCP7-GA-2008-217878
· HERCULES-C project within EC's 7th Framework Program: Contract SCP1-GA-2011-284354
· HERCULES-2 project within European Union’s Horizon 2020 research and innovation programme under
grant agreement No 634135
The additional financial support by the Swiss Federal Government during several projects:
· Contract 154269, Project 103241,
· SFOE Contract SI/500940, TP Nr 8100075, Project name “FlexFuel Combustion”
· SFOE Contract SI/501299-01, TP Nr 8100075, Project name “INFLOSCOM”
is gratefully acknowledged.
Over the past years, a fantastic collaboration has been established with and among the different partners. The
sincere thank therefore goes to the experts and people who took part in the long journey and are still invaluable
allies:
· ETH Zürich
· PSI Villigen
· EMPA Dübendorf
· FHNW Brugg-Windisch
· IFPEN Paris
· NTUA Athens
· Chalmers University of Technology GothenburgSchmid, A.; Yamada, N. (2017). Spray Combustion Chamber: History and Future of a Unique Test Facility. En Ilass Europe. 28th european conference on Liquid Atomization and Spray Systems. Editorial Universitat Politècnica de València. 863-870. https://doi.org/10.4995/ILASS2017.2017.4734OCS86387
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