The Tamm-Dancoff Approximation as the boson limit of the Richardson-Gaudin equations for pairing

A connection is made between the exact eigen states of the BCS Hamiltonian and the predictions made by the Tamm-Dancoff Approximation. This connection is made by means of a parametrised algebra, which gives the exact quasi-spin algebra in one limit of the parameter and the Heisenberg-Weyl algebra in the other. Using this algebra to construct the Bethe Ansatz solution of the BCS Hamiltonian, we obtain parametrised Richardson-Gaudin equations, leading to the secular equation of the Tamm-Dancoff Approximation in the bosonic limit. An example is discussed in depth.Comment: Submitted to the proceedings of the Group28 conference (Newcastle-upon-Tyne, UK). Journal of Physics: Conference Serie

A conceptual framework for circular design

Design has been recognised in the literature as a catalyst to move away from the traditional model of take-make-dispose to achieve a more restorative, regenerative and circular economy. As such, for a circular economy to thrive, products need to be designed for closed loops, as well as be adapted to generate revenues. This should not only be at the point of purchase, but also during use, and be supported by low-cost return chains and reprocessing structures, as well as effective policy and regulation. To date, most academic and grey literature on the circular economy has focused primarily on the development of new business models, with some of the latter studies addressing design strategies for a circular economy, specifically in the area of resource cycles and design for product life extension. However, these studies primarily consider a limited spectrum of the technical and biological cycles where materials are recovered and restored and nutrients (e.g., materials, energy, water) are regenerated. This provides little guidance or clarity for designers wishing to design for new circular business models in practice. As such, this paper aims to address this gap by systematically analysing previous literature on Design for Sustainability (DfX) (e.g., design for resource conservation, design for slowing resource loops and whole systems design) and links these approaches to the current literature on circular business models. A conceptual framework is developed for circular economy design strategies. From this conceptual framework, recommendations are made to enable designers to fully consider the holistic implications for design within a circular economy

Representations of the Weyl group and Wigner functions for SU(3)

Bases for SU(3) irreps are constructed on a space of three-particle tensor products of two-dimensional harmonic oscillator wave functions. The Weyl group is represented as the symmetric group of permutations of the particle coordinates of these space. Wigner functions for SU(3) are expressed as products of SU(2) Wigner functions and matrix elements of Weyl transformations. The constructions make explicit use of dual reductive pairs which are shown to be particularly relevant to problems in optics and quantum interferometry.Comment: : RevTex file, 11 pages with 2 figure

Understanding the Diversity of Interconnections between IS: Towards a New Typology of IOS

Electronic exchanges of information between Businesses have continued to grow over recent decades. Though the emergence of new technologies, firms are facing new opportunities to build Interorganizational Information Systems (IOSs) to organize electronic data exchanges to update their own information systems. In this paper, we focus on flows from suppliers to retailers of product information, a set of data that describe the product manufactured by suppliers and retailed by wholesalers to the end consumer. We propose a new methodology to analyze IOSs, by considering how suppliers build their sending systems, how retailers build their receiving systems and how their interconnections lead to the creation of IOSs. Through a qualitative research based on interviews and documentation reviews, we describe and discuss the possibilities of interconnections between sending and receiving systems based on data privacy, structural linkages and message interdependencies

ADOPTION FACTORS OF ELECTRONIC DATA EXCHANGE AND TECHNOLOGY: CAN WE DISTINGUISH TWO PHASES?

In concordance with the emergence of technologies that allow more flexible interconnections, we propose to divide Interorganizational Information Systems (IOSs) adoption into two decision processes: electronic data exchange adoption and technological choices. These are sequentially and (in extreme cases) simultaneously related, albeit distinct, since an electronic data exchange decision rarely imposes a technological choice. In this context, the research aims at distinguishing factors influencing the decision for a company to adopt electronic data exchanges with its partners, and factors influencing the decision to adopt technologies supporting these electronic data exchanges. We investigate product information exchanges in the French consumer goods and retail industries through external catalogues, internal catalogues and Extranets. Analysis of 25 case studies allows us to conclude that it is relevant to distinguish these two decisions and the factors influencing each one

From Ideal Data Synchronization to Hybrid Forms of Interconnections: Architectures, Processes, and Data

With the emergence of new technologies, companies can organize their electronic data exchanges by implementing hybrid interorganizational information systems (IOS). This paper presents a new analytical framework by considering IOS as the product of interconnections between the parts of IS developed by connected firms to support a given interorganizational process. We focus on updating internal databases through data synchronization between a set of suppliers and a set of clients. From the literature, we built types of sending and receiving systems based on three variables; namely, shared data, structural linkages, and message interdependency. Analytically, we derived possibilities of interconnections between these sending and receiving systems with asymmetric characteristics. In a field study, we empirically investigated IOS built to support product information flows from suppliers’ to retailers’ internal, databases by considering how suppliers built their sending systems, how retailers built their receiving systems, and how their interconnections led to different forms of IOS. Interconnections occurring between systems with asymmetric characteristics show the existence of several hybrid forms of IOS, both in design and use. We finally explain that, even if companies can benefit from their use, hybrid forms are less efficient than are extreme forms, those that are the result of interconnections between systems with symmetric characteristics

Adoption Factors of Electronic Data Exchanges and Technologies to Improve Data Synchronization in BtoB Relationships: Are they similar?

Because of the emergence of technologies that allow more flexible interconnections, we propose to divide Interorganizational Information Systems (IOSs) adoption into two decision processes: electronic data exchanges adoption and technological choices. Indeed they are sequentially and in extreme case simultaneously related but independent since electronic data exchanges decision rarely imposes a technological choice. In this context, the research aims at distinguishing factors influencing the decision for a company to adopt electronic data exchanges with its partners and factors influencing the decision to adopt technologies supporting these electronic data exchanges. We investigate product information exchanges in the French consumer goods and retail industry through external catalogue, internal catalogue and Extranets. Analysis of 25 case studies allows us to conclude that it is relevant to distinguish these two decisions and the factors influencing each one

The quadrupole collective model from a Cartan-Weyl perspective

The matrix elements of the quadrupole variables and canonic conjugate momenta, emerging from collective nuclear models are calculated within a $SU(1,1)\times O(5)$ basis. Using a harmonic oscillator implementation of the SU(1,1) degree of freedom, it can be shown that the matrix elements of the quadrupole phonon creation and annihilation operators can be calculated in a pure algebraic way, making use of an intermediate state method.Comment: Special issue of journal of physics for the QTS5 conferenc