iTIMP: isotriplet Technicolor Interacting Massive Particle as Dark Matter

We suggest that a weak isotriplet composite scalar possessing an unbroken U(1) global symmetry naturally arises in technicolor models leading to an interesting type of dark matter candidate: the iTIMP. We propose explicit models of the iTIMP, study earth based constraints and suggest possible collider signals.Comment: 4 pages, 4 Figures, added content, added reference

Two-dimensional Pareto frontier forecasting for technology planning and roadmapping

Technology evolution forecasting based on historical data processing is a useful tool for quantitative analysis in technology planning and roadmapping. While previous efforts focused mainly on one-dimensional forecasting, real technical systems require the evaluation of multiple and conflicting figures of merit at the same time, such as cost and performance. This paper presents a methodology for technology forecasting based on Pareto (efficient) frontier estimation algorithms and multiple regressions in presence of at least two conflicting figures of merits. A tool was developed on the basis of the approach presented in this paper. The methodology is illustrated with a case study from the automotive industry. The paper also shows the validation of the methodology and the estimation of the forecast accuracy adopting a backward testing procedure

A game-theoretic framework for concurrent technology roadmap planning using best-response techniques

Technology roadmapping provides a tool for technology planning and selecting what to pursue in what timeframes. In this paper, a game-theoretic framework for technology roadmap planning is proposed to address the enumeration, selection and evaluation of possible evolution paths for technology roadmapping characterized by an iterative and competitive technology development process between companies within one tradespace. More specifically, the framework including companies as game players demonstrates the most favorable reactions to each other's technology development by approximated best response functions. Next, the selection process of optimal development paths is carried out to evaluate the possible payoffs using backward induction. Finally, a case is studied to demonstrate the feasibility of the proposed approach

Identifying retrofitting opportunities for Federated Satellite Systems

This work aims to facilitate deployment of novel distributed space systems architectures such as Federated Satellite Systems (FSS). In particular, the purpose of the work is to identify retrofitting possibilities to incorporate existing satellites into a network. For the satellite case, the paper presents a systematic review of possible retrofitting options such as direct modifications, which include replacement and addition of interfaces, and indirect modifications with adding an intermediary (FSS Negotiator). While the paper concludes that direct modifications of existing satellites are non-feasible from the technical point of view, it also identifies a possible scenario of retrofitting by adding as an intermediary a Negotiator satellite. The link budget for the inter-satellite link between an existing satellite mission such as SPOT-6 and FSS Negotiator was estimated. The work concludes that from the link budget point of view with the existing communication technologies such configuration can provide a slant range limited from several hundred to thousands kilometers. Through analysis of open data of satellite characteristics, including ITU information concerning planned or existing space stations, the work comes up with several models for the further trade-off analysis, identifying how parameters of FSS Negotiator such as an operated bandwidth and frequency, types of supported modulations and cumulative throughput correlate with the covered number of satellites. These results might be used for the tradeoff analysis for the FSS Negotiator mission design. Eventually paper proposes several possible FSS Negotiator architectures and its high-level technical requirements based on analysis of characteristics of existed and planned satellites

Measures and approch for modernization of existing systems

International audienceDue to accelerating technological progress any engineered system eventually becomes obsolete and the question arises as to its modernization. Disciplines such as change and configuration management propose methods to maintain system at operational level by incorporating relatively small changes. When major rebuild is required to the system, existing literature proposes to follow the same System Engineering processes as during new system design and development. Systems Engineering, traditionally focused on design and development of new systems, paying limited attention to modernization of existing ones and its processes need to be specially tailored to the modernization of existing system. In the case of straightforward application of Systems Engineering processes, the step of new system formulation is often neglected and considered as something already granted. This paper gives an overview of approaches and methods in the field of system modernization. It proposes a metrics for classification of different types of system modernization. To facilitate system modernization this work introduces a framework based on proposed metrics, Design Structure Matrixes and functional analysis. The framework consists of decomposition and synthesis phases and aims to define new (modified) system, by providing a set of alternatives. The proposed framework anticipates application of traditional System Engineering approach. The paper is illustrated with an example in the field of car retrofitting

Introduction to the Special Section on Advances in Federated and Fractionated Satellite Systems

THIS Special Section of the Journal on Spacecraft and Rockets was created based on the 5th International Workshop on Federated and Fractionated Satellite Systems (FSS Workshop) that has taken place in at ISAE-SUPAERO, Toulouse, France, on 2 and 3 November 2017. The Fifth edition of the Workshop came after four events that had previously taken place at MIT (Boston) in 2012, at the Skolkovo Institute of Science and Technology (Moscow) in 2014, at Cornell University (Ithaca) in 2015, and at La Sapienza University (Rome) in 2016. The workshop aimed at forging links to create a multidisciplinary and international research and industrial community that will follow novel approaches to innovate the way in which spacecraft missions are conceived, designed, implemented, and operated. During the two-day workshop in Toulouse, a keynote address was delivered by Grazia Vittadini, at that time Head of Engineering at Airbus Defence and Space, and a keynote address was delivered by Giancarlo Filippazzo, Copernicus Programme Coordinator of the European Space Agency (ESA). In addition, 10 scientific contributions were made by a variety of contributors from all over the world. For this Special Section, 4 of those contributions have been further developed into full journal papers, that have then been reviewed and handled according to AIAA’s Journal of Spacecraft and Rockets (JSR) standards. Federated Satellite Systems (FSS) is a new concept in space systems design aiming at creating a commercial cloud-computing environment enabling sharing and trading of in-space resources between spacecraft. FSS is an instance of distributed satellite systems; DSS encompass concepts such as fractionated spacecraft, satellite constellations, and other systems architectures looking at distributing decision-making, functionality and ownership across multiple flying units. Federated satellites exchange resources such as link capacity, downlink capacity, processing capability and storage capacity. This exchange improves the efficiency utilization of spacecraft resources and makes use of unallocated resource margins of participating missions. The research community started to explore benefits and costs of a federated approach to spacecraft design, and several research avenues have just started opening in this field. From a commercial perspective, the federated satellite systems concept allows the creation of new markets of in-space resources, among other benefits in spacecraft cost, performance, and reliability. The commercial viability of federated satellite system concepts started to emerge in 2017–2018, when we started seeing important investments in space startups developing distributed systems for commercial data relay and cloud data storage, implementing some of the ideas that were originally envisioned in the federated satellite system paradigm. It seems clear that the time is ripe for the exploitation of federative concepts in space. To do so, several technical questions on space systems design and architecture, connectivity, and related research areas need to be solved. This special section addresses some of the abovementioned technical issues, looking at both technology and system layers of federated systems in space. The first paper, “Architectural optimization results for a network of Earth-observing satellite nodes” by Carles Araguz et al., describes part of the results of the ONION project, a European research project devoted to study distributed satellite systems and their architecting characteristics. The paper in particular addresses the challenge of designing novel space systems. Very strict requirements, combined with the consolidation of small-satellite platforms and novel distributed architecture approaches, are stressing the need to study the design of new, heterogeneous and heavily networked satellite systems that can potentially replace or complement traditional space assets. This paper presents a design-oriented framework that allows selecting optimal architectures for a given user needs. The second paper, “Cluster-keeping Algorithms for the Satellite Swarm Sensor Network Project” by Eviatar Edlerman and Pini Gurfil, looks into cluster control algorithms for the satellite swarms, illustrated by the Satellite Swarm Sensor Network (S3Net) project. A methodological development of orbit control algorithms is presented, with emphasis on outlining the algorithms structure, information flow, and software implementation. The methodology enables operation of multiple satellites in coordination, to enable fractionation of space sensors and augmentation of data provided therefrom. In the paper “Identifying retrofitting opportunities for Federated Satellite Systems” by Rustam Akhtyamov et al. the authors address the possibilities of including FSS-like capabilities in existing satellite structures. Such retrofitting possibilities, for this particular case or in general, are important items for industry today. In this paper, a systematic review of possible retrofitting options such as direct modifications, which include replacement and addition of interfaces, and indirect modifications with adding an intermediary (FSS Negotiator) are addressed. And finally, in the paper “Impact of Delayed Acknowledgment on TCP performance over LEO satellite constellations” by Bastien Tauran et al., the authors aim at quantifying the impact of a default TCP option, Delayed Acknowledgment (DelAck), in the context of LEO satellite constellations. To cope with high channel impairment that may affect such satellite constellations, physical and link layer reliability schemes have been introduced, at the price of an increase of the end-to-end delay seen by the transport layer (e.g. TCP). Although DelAck is used to decrease the feedback path load and for overall system performance, the use of this option conjointly with satellite link layer recovery schemes might increase the delay and might be counterproductive. The Guest Editors would like to thank all the reviewers that helped to evaluate the papers and, indeed, bring them to a higher level. Their constructive support was very much appreciated. A. Golkar and R. Vingerhoeds Toulouse, April 201

Model-based representational similarity analysis of blood-oxygen-level-dependent fMRI captures threat learning in social interactions

Past research has shown that attributions of intentions to other's actions determine how we experience these actions and their consequences. Yet, it is unknown how such attributions affect our learning and memory. Addressing this question, we combined neuroimaging with an interactive threat learning paradigm in which two interaction partners (confederates) made choices that had either threatening (shock) or safe (no shock) consequences for the participants. Importantly, participants were led to believe that one partner intentionally caused the delivery of shock, whereas the other did not (i.e. unintentional partner). Following intentional versus unintentional shocks, participants reported an inflated number of shocks and a greater increase in anger and vengeance. We applied a model-based representational similarity analysis to blood-oxygen-level-dependent (BOLD)-MRI patterns during learning. Surprisingly, we did not find any effects of intentionality. The threat value of actions, however, was represented as a trial-by-trial increase in representational similarity in the insula and the inferior frontal gyrus. Our findings illustrate how neural pattern formation can be used to study a complex interaction

Introduction to the Special Section on Advances in Federated and Fractionated Satellite Systems

This Special Section of the Journal on Spacecraft and Rockets was created based on the 5th International Workshop on Federated and Fractionated Satellite Systems (FSS Workshop) that has taken place in at ISAE-SUPAERO, Toulouse, France, on 2 and 3 November 2017. The Fifth edition of the Workshop came after four events that had previously taken place at MIT (Boston) in 2012, at the Skolkovo Institute of Science and Technology (Moscow) in 2014, at Cornell University (Ithaca) in 2015, and at La Sapienza University (Rome) in 2016. The workshop aimed at forging links to create a multidisciplinary and international research and industrial community that will follow novel approaches to innovate the way in which spacecraft missions are conceived, designed, implemented, and operated