Thermodynamic work from operational principles

In recent years we have witnessed a concentrated effort to make sense of thermodynamics for small-scale systems. One of the main difficulties is to capture a suitable notion of work that models realistically the purpose of quantum machines, in an analogous way to the role played, for macroscopic machines, by the energy stored in the idealisation of a lifted weight. Despite of several attempts to resolve this issue by putting forward specific models, these are far from capturing realistically the transitions that a quantum machine is expected to perform. In this work, we adopt a novel strategy by considering arbitrary kinds of systems that one can attach to a quantum thermal machine and seeking for work quantifiers. These are functions that measure the value of a transition and generalise the concept of work beyond the model of a lifted weight. We do so by imposing simple operational axioms that any reasonable work quantifier must fulfil and by deriving from them stringent mathematical condition with a clear physical interpretation. Our approach allows us to derive much of the structure of the theory of thermodynamics without taking as a primitive the definition of work. We can derive, for any work quantifier, a quantitative second law in the sense of bounding the work that can be performed using some non-equilibrium resource by the work that is needed to create it. We also discuss in detail the role of reversibility and correlations in connection with the second law. Furthermore, we recover the usual identification of work with energy in degrees of freedom with vanishing entropy as a particular case of our formalism. Our mathematical results can be formulated abstractly and are general enough to carry over to other resource theories than quantum thermodynamics.Comment: 22 pages, 4 figures, axioms significantly simplified, more comprehensive discussion of relationship to previous approache

Information system for operation analysis of time series

This work is devoted to modern information technology of operational analysis of time series. The main purpose of data operational analysis is replenishment, data blurring, smoothing and forecasting of time series, obtaining conclusions about periodicity, cyclicity, character of the behavior of the observed process. Also attention is paid to the task of separating noise or observational errors from real data

Kernel alternatives to aproximate operational severity distribution: an empirical application

The estimation of severity loss distribution is one the main topic in operational risk estimation. Numerous parametric estimations have been suggested although very few work for both high frequency small losses and low frequency big losses. In this paper several estimation are explored. The good performance of the double transformation kernel estimation in the context of operational risk severity is worthy of a special mention. This method is based on the work of Bolancé and Guillén (2009), it was initially proposed in the context of the cost of claims insurance, and it means an advance in operational risk research

Insight private equity : [Version 18 June 2013]

We are able to shed light on the black box of restructuring tools private equity investors use to improve the operational performance of their portfolio companies. By building on previous work considering performance evaluation of PE backed companies, we analyze whether private equity improves operating efficiency and which of the typical restructuring tools are the main performance drivers. Using a set of over 300 international leveraged buyout transactions of the last thirty years, we find that while there is vast improvement in operational efficiency, these gains vary considerably. Our top performing transactions are subject to strong equity incentives, frequent asset restructuring and tight control by the investor. Furthermore, investors’ experience has a positive influence while financial leverage has no influence on operational performance

Non universality of entanglement convertibility

Recently, it has been suggested that operational properties connected to quantum computation can be alternative indicators of quantum phase transitions. In this work we systematically study these operational properties in 1D systems that present phase transitions of different orders. For this purpose, we evaluate the local convertibility between bipartite ground states. Our results suggest that the operational properties, related to non-analyticities of the entanglement spectrum, are good detectors of explicit symmetries of the model, but not necessarily of phase transitions. We also show that thermodynamically equivalent phases, such as Luttinger liquids, may display different convertibility properties depending on the underlying microscopic model.Comment: 5 pages + references, 4 figures - improved versio

First Class Call Stacks: Exploring Head Reduction

Weak-head normalization is inconsistent with functional extensionality in the call-by-name $\lambda$-calculus. We explore this problem from a new angle via the conflict between extensionality and effects. Leveraging ideas from work on the $\lambda$-calculus with control, we derive and justify alternative operational semantics and a sequence of abstract machines for performing head reduction. Head reduction avoids the problems with weak-head reduction and extensionality, while our operational semantics and associated abstract machines show us how to retain weak-head reduction's ease of implementation.Comment: In Proceedings WoC 2015, arXiv:1606.0583

Optimizing the process of supercritical extraction of lemon balm (Melissa Officinalis L.)

This work investigates the process of extraction of lemon balm (Melissa officinalis L.) by treatment with carbon dioxide at supercritical conditions. The process kinetics is studied at different operational conditions, and the influence of some important regime parameters (pressure, temperature particle size, solvent flow-rate) on the extraction yield is experimentally determined. Besides the information for process intensity at particular operational regimes, the results are useful for selection of favourable operational conditions for better extraction, i.e. for production of larger quantity of extracted substances from unit mass of raw material

Human Activity Modelling in the Specification of Operational Requirements: Work in Progress

This paper describes our experience of integrating HCI concepts and techniques into a concurrent requirements engineering process called RESCUE. We focus on the use of a model of current human activity to inform specification of a future system. We show how human activity descriptions, written using a specially designed template, can facilitate the authoring of use case descriptions to be used in the elicitation of requirements for complex socio-technical systems. We describe our experience of using descriptions of human activity, written using the template, to support specification of operational requirements for DMAN, a system to support air traffic controllers in managing the departure of aircraft from airports. We end with a discussion of lessons learnt from our experience and present some ideas for future development of work in this area

The systemic dimension of operational decision in complex systems work

This paper refers to some of my research findings on Decision Making processes in complex systems work. Starting as a complex cognitive process strongly contextualized in the operating environment, it ends up, in complex systems work, as an equally complex network of actors and systems (human and technological) that are confronted, in real time, with uncertainty , a large amount of information and feedback and with multiple standards and operating procedures...Complex systems work; Operational Decision; Mental Model; Situational awareness; Systemic decision

Subsea approach to work systems development

Self-contained undersea working environments with applications to space station EVA environments are discussed. Physiological limitations include decompression, inert gas narcosis, high-pressure nervous system, gas toxicity, and thermal limitations. Work task requirements include drilling support, construction, inspection, and repair. Work systems include hyperbaric diving, atmospheric work systems, tele-operated work systems, and hybrid systems. Each type of work system is outlined in terms of work capabilities, special interface requirements, and limitations. Various operational philosophies are discussed. The evolution of work systems in the subsea industry has been the result of direct operational experience in a competitive market