Six-degree-of-freedom missile simulation using the ADI AD 100 digital computer and ADSIM simulation language

The use of an AD 100 computer and the ADSIM language in the six-degree-of-freedom digital simulation of an air-to-ground missile is illustrated. The missile is launched from a moving platform, typically a helicopter, and is capable of striking a mobile target up to 10 kilometers away. The missile could be any tactical missile. The performance numbers of the AD 100 show that it is possible to implement a high performance missile model in a real-time simulation without the problems associated with an implementation on a general purpose computer using FORTRAN

Concepts, reflections and applications of social equity: approaches to accessibility to primary goods and services in the region of Flanders, Belgium

Mobility presents a variety of opportunities as it allows users to access locations and services, and to meet people beyond their immediate surroundings. While the concept of mobility primarily focuses on the ease of moving, accessibility delineates the actual potential to participate in out-of-home activities. As a result, accessibility is a complex concept with a multitude of foci. This complexity is presented in the first section, which explains the general concept of accessibility, how it is defined and how it is related to the notion of transport-related exclusion. This section also gives an overview of the body of literature on the measures to determine area-based as well as personal accessibility levels and points out the important contrast between the simple, easy-to-interpret methods, adopted by policy makers and the complex methods preferred by experts. The second section clarifies how the dichotomous relationship between the urban and rural environment is reflected in transport policy that emphasizes on (especially car-based) mobility rather than on accessibility. Furthermore, the environmental and economic points of view are highlighted and the common policy strategies focused on sustainability are illustrated. Subsequently, the shortcomings in the way in which the contemporary debates concerning mobility, sustainability and the social implications of transport planning are conducted, are criticized. Finally, the last part of this section is dedicated to an extensive discussion on the ability of transport policies to, on the one hand, generate spatially as well as temporally uneven accessibility effects that give preference to certain population groups above others, and on the other hand, their ability to strive for a more equitable distribution of transport services amongst the population. The third section proposes two methodologies for measuring transport-related social exclusion implemented in a literature-based case study in Flanders. These studies comprise the following topics: measuring transport gaps by relating the social to the transport disadvantage and measuring modal disparities by comparing accessibility by private and public transport. The former investigates in which areas the provision of the public transport system is not tailored to specific public transport needs. The latter examines the disparity in access by private and public transport in order to highlight the car dependency. Both case studies incorporate the temporal variability in provision through the private and public transport network, as the time-of-day strongly influences accessibility levels

Fast Damage Recovery in Robotics with the T-Resilience Algorithm

Damage recovery is critical for autonomous robots that need to operate for a long time without assistance. Most current methods are complex and costly because they require anticipating each potential damage in order to have a contingency plan ready. As an alternative, we introduce the T-resilience algorithm, a new algorithm that allows robots to quickly and autonomously discover compensatory behaviors in unanticipated situations. This algorithm equips the robot with a self-model and discovers new behaviors by learning to avoid those that perform differently in the self-model and in reality. Our algorithm thus does not identify the damaged parts but it implicitly searches for efficient behaviors that do not use them. We evaluate the T-Resilience algorithm on a hexapod robot that needs to adapt to leg removal, broken legs and motor failures; we compare it to stochastic local search, policy gradient and the self-modeling algorithm proposed by Bongard et al. The behavior of the robot is assessed on-board thanks to a RGB-D sensor and a SLAM algorithm. Using only 25 tests on the robot and an overall running time of 20 minutes, T-Resilience consistently leads to substantially better results than the other approaches

Rheological Measurements in Liquid-Solid Flows

The behavior of liquid-solid flows varies greatly depending on fluid viscosity, particle and liquid inertia, and collisions between particles. While particle collisions in inviscid fluids can be understood statistically, liquid-solid flows are complicated by the fluid viscosity and forces acting on the particles (e.g. lift, drag, added mass). These flows were first studied by Bagnold, whose investigation found two different flow regimes: a macro-viscous regime where the shear and pressure forces are proportional to the shear rate, and a grain-inertia regime defined by a dependance on the square of the shear rate [1, 2]. The scaling relations he developed have been used to model and understand natural phenomena since

Stochastic Games on a Product State Space

We examine product-games, which are n-player stochastic games satisfying: (1) the state space is a product S(1)Ãâ¦ÃS(n); (2) the action space of any player i only depends of the i-th coordinate of the state; (3) the transition probability of moving from s(i) ∈ S(i) to t(i) ∈S(i), on the i-th coordinate S(i) of the state space, only depends on the action chosen by player i. So, as far as the actions and the transitions are concerned, every player i can play on the i-th coordinate of the product-game without interference of the other players. No condition is imposed on the payoff structure of the game. We focus on product-games with an aperiodic transition structure, for which we present an approach based on so-called communicating states. For the general n-player case, we establish the existence of 0-equilibria, which makes product-games one of the first classes within n-player stochastic games with such a result. In addition, for the special case of two-player zero-sum games of this type, we show that both players have stationary 0-optimal strategies. Both proofs are constructive by nature.Economics (Jel: A)

Second order phase dispersion by optimised rotation pulses

We show that the duration of broadband universal control pulses can be halved by choosing control targets with a quadratic function of phase dispersion. This class of control pulses perform a broadband universal rotation around an axis, in the Bloch sphere representation of two-level systems, given by this phase dispersion function. We present an effective optimal control method to avoid the problem of convergence to local extrema traps.Comment: 8 pages, 4 figure

The use of geographical applications for micro-planning school locations : the @SCHOOL app for preschools in Ghent, Belgium

Parallel with the increased use of internet technology, more and more data becomes freely accessible\ However, most of this data is only available in its raw form and centrally managed and thus not legible or applicable for non-professionals. Especially for primary needs such as health care or education, the availability of relevant information for inhabitants is crucial in improving their quality of life. Because education is one of the focal points in regional as well as in local policy, a dataset containing detailed information about school locations and characteristics was compiled on the regional level Flanders. However, this data is centrally owned and not made accessible for the public by a user-friendly tool. Therefore, a geographical application was developed, aimed at improving inhabitants' access to information concerning preschool locations in Ghent (Belgium). The combination of two open source programs (Google Docs and ESRI ArcGIS Online) makes it possible to centrally update the tool and make it available for all internet users in real-time. In the first phase, local authorities as well as civilians are able to request all relevant information (i.e. school name, school address, capacity, Google street view) about the selected nursery school in Ghent by implementing this user-friendly and open source tool. Furthermore, the tool can be used to determine which preschool is closest to a specific address. In the next phase, the dataset used in the application will be extended to contain information concerning all primary schools of the Flemish community. Today, the application is used by different local authorities as a tool for policy support and is available to inhabitants in Ghent in the process of enrolment ('Central Application Register' or CAR). The convenient and intuitive interface makes the tool inclusive for poorly-educated parents or internet illiterates

Dosso's Ambiguity

In recent years ambiguity has become a matter of great interest among scholars of early modern visual art. While the declared goal of humanistically-oriented iconology was to determine a painting's "one and real" meaning from a historical point of view, the idea has come to be accepted today that many works of Renaissance art do not correspond to this unequivocalness, but are rather open, many-sided and semantically highly ambiguous. This ambiguity may be diverse and may apply equally to the illusioned content, the relationship between the painting and the viewer or the technical dimension that yields the picture as such. Taking a work of art out of its original context as well as historical distance may considerably intensify latent qualities of ambiguity. It seems to me to be essential, however, to distinguish two basic forms of ambiguity: on the one hand, the general openness of the meaning of an image, as, for example, described by so diverse authors like Umberto Eco, Theodore W. Adorno or Hans Blumenberg as being a valid quality and a normative category of every work of art. And on the other hand, the ambiguity that is deliberately produced by artists, created by the omission of significant attributes, the use of equivocal symbols or the addition of extraneous motives. As stressed by Valeska von Rosen in her recent publication on Caravaggio, this "intended (structural or strategic) ambiguity" is a phenomenon discussed since antiquity under the terms of "amphibolia" or "obscuritas". Early modern Italian art theory, however, which sought first and foremost to define norms for the effective visual conversion of a more or less clearly defined content, did not deal explicitly and dominantly with visual ambiguity