User engineering: A new look at system engineering

User Engineering is a new System Engineering perspective responsible for defining and maintaining the user view of the system. Its elements are a process to guide the project and customer, a multidisciplinary team including hard and soft sciences, rapid prototyping tools to build user interfaces quickly and modify them frequently at low cost, and a prototyping center for involving users and designers in an iterative way. The main consideration is reducing the risk that the end user will not or cannot effectively use the system. The process begins with user analysis to produce cognitive and work style models, and task analysis to produce user work functions and scenarios. These become major drivers of the human computer interface design which is presented and reviewed as an interactive prototype by users. Feedback is rapid and productive, and user effectiveness can be measured and observed before the system is built and fielded. Requirements are derived via the prototype and baselined early to serve as an input to the architecture and software design

Neutrinos and the synthesis of heavy elements: the role of gravity

The synthesis of heavy elements in the Universe presents several challenges. From one side the astrophysical site is still undetermined and on other hand the input from nuclear physics requires the knowledge of properties of exotic nuclei, some of them perhaps accessible in ion beam facilities. Black hole accretion disks have been proposed as possible r-process sites. Analogously to Supernovae these objects emit huge amounts of neutrinos. We discuss the neutrino emission from black hole accretion disks. In particular we show the influence that the black hole strong gravitational field has on changing the electron fraction relevant to the synthesis of elements.Comment: 5 pages, 5 figures, Invited talk at the 15th International Symposium on Capture Gamma-Ray Spectroscopy and Related Topics (CGS15), to appear in EPJ Web of Conference

NEW DEVELOPMENTS IN GROCERY MANUFACTURER AND DISTRIBUTOR MARKETING PROGRAMS: A SURVEY OF U.S. WHOLESALERS AND RETAILERS

The retail food industry has taken initiatives to improve cost and to return the focus of management to the consumer. Among these initiatives are Efficient Consumer Response (ECR) and category management. A mail questionnaire elicited perceptions on these issues from 95 executives among U.S. food wholesalers and retailers. This study found that ECR category management are being used to streamline costs and to remove logistical inefficiencies. Although it is widely recognized that category management provides a consumer focus, distributors seemingly brush aside tactics that target individual customers in favor of efforts that target logistical efficiency.Agribusiness, Marketing,

Implementable Wireless Access for B3G Networks - III: Complexity Reducing Transceiver Structures

This article presents a comprehensive overview of some of the research conducted within Mobile VCE’s Core Wireless Access Research Programme,1 a key focus of which has naturally been on MIMO transceivers. The series of articles offers a coherent view of how the work was structured and comprises a compilation of material that has been presented in detail elsewhere (see references within the article). In this article MIMO channel measurements, analysis, and modeling, which were presented previously in the first article in this series of four, are utilized to develop compact and distributed antenna arrays. Parallel activities led to research into low-complexity MIMO single-user spacetime coding techniques, as well as SISO and MIMO multi-user CDMA-based transceivers for B3G systems. As well as feeding into the industry’s in-house research program, significant extensions of this work are now in hand, within Mobile VCE’s own core activity, aiming toward securing major improvements in delivery efficiency in future wireless systems through crosslayer operation

Phase Mixing of Alfvén Waves Near a 2D Magnetic Null Point

The propagation of linear Alfvén wave pulses in an inhomogeneous plasma near a 2D coronal null point is investigated. When a uniform plasma density is considered, it is seen that an initially planar Alfvén wavefront remains planar, despite the varying equilibrium Alfvén speed, and that all the wave collects at the separatrices. Thus, in the non-ideal case, these Alfvénic disturbances preferentially dissipate their energy at these locations. For a non-uniform equilibrium density, it is found that the Alfvén wavefront is significantly distorted away from the initially planar geometry, inviting the possibility of dissipation due to phase mixing. Despite this however, we conclude that for the Alfvén wave, current density accumulation and preferential heating still primarily occur at the separatrices, even when an extremely non-uniform density profile is considered

A modified Newton-Raphson analysis of flight measurements of the trailing vortices of a heavy jet transport

A modified Newton-Raphson method has been used to determine the parameters in equations describing the vortex flow to obtain a best match with flight measurements of the flow behind the C-5A airplane. The flight measurements were made using a specially instrumented T-33 airplane which passed as closely as possible to the centers of the trailing vortices at several distances behind the C-5A airplane. The flight measurements were transformed to flow velocity relative to an inertial frame of reference. The assumed form of the flow consisted of the superposition of two counterrotating, finite core vortices. The positions of the vortex centers, their total circulation, the effective eddy viscosity and measurement bias were the parameters adjusted. The assumed form of vortex flow fit well the measured velocities for the numerous sets of data, both flaps up and down for the C-5A airplane. The resulting values of total circulation, however, were about two-thirds that expected of a wing with an elliptical loading. A partial explanation of the less than expected circulation is a dip in the spanwise lift distribution at the airplane's center line. The distance between the trailing vortices at the smallest times encountered is somewhat less than that expected for an elliptical wing loading

Induced antiferromagnetism and large magnetoresistances in RuSr2(Nd,Y,Ce)2Cu2O10-d ruthenocuprates

RuSr2(Nd,Y,Ce)2Cu2O10-d ruthenocuprates have been studied by neutron diffraction, magnetotransport and magnetisation measurements and the electronic phase diagram is reported. Separate Ru and Cu spin ordering transitions are observed, with spontaneous Cu antiferromagnetic order for low hole doping levels p, and a distinct, induced-antiferromagnetic Cu spin phase in the 0.02 < p < 0.06 pseudogap region. This ordering gives rise to large negative magnetoresistances which vary systematically with p in the RuSr2Nd1.8-xY0.2CexCu2O10-d series. A collapse of the magnetoresistance (MR) and magnetisation in the pre-superconducting region may signify the onset of superconducting fluctuations.Comment: 22 pages, 11 figure

Non-universality of dark-matter halos: cusps, cores, and the central potential

Dark-matter halos grown in cosmological simulations appear to have central NFW-like density cusps with mean values of $d\log\rho/d\log r \approx -1$, and some dispersion, which is generally parametrized by the varying index $\alpha$ in the Einasto density profile fitting function. Non-universality in profile shapes is also seen in observed galaxy clusters and possibly dwarf galaxies. Here we show that non-universality, at any given mass scale, is an intrinsic property of DARKexp, a theoretically derived model for collisionless self-gravitating systems. We demonstrate that DARKexp - which has only one shape parameter, $\phi_0$ - fits the dispersion in profile shapes of massive simulated halos as well as observed clusters very well. DARKexp also allows for cored dark-matter profiles, such as those found for dwarf spheroidal galaxies. We provide approximate analytical relations between DARKexp $\phi_0$, Einasto $\alpha$, or the central logarithmic slope in the Dehnen-Tremaine analytical $\gamma$-models. The range in halo parameters reflects a substantial variation in the binding energies per unit mass of dark-matter halos.Comment: ApJ, in press, 10 pages, 7 figure