Electro-Weak Dark Matter: non-perturbative effect confronting indirect detections

We update indirect constraints on Electro-Weak Dark Matter (EWDM) considering the Sommerfeld-Ramsauer-Townsend (SRT) effect for its annihilations into a pair of standard model gauge bosons assuming that EWDM accounts for the observed dark matter (DM) relic density for a given DM mass and mass gaps among the multiplet components. For the radiative or smaller mass splitting, the hypercharged triplet and higher multiplet EWDMs are ruled out up to the DM mass ~ 10 - 20 TeV by the combination of the most recent data from AMS-02 (antiproton), Fermi-LAT (gamma-ray), and HESS (gamma-line). The Majorana triplet (wino-like) EWDM can evade all the indirect constraints only around Ramsauer-Townsend dips which can occur for a tiny mass splitting of order 10 MeV or less. In the case of the doublet (Higgsino-like) EWDM, a wide range of its mass > 500 GeV is allowed except Sommerfeld peak regions. Such a stringent limit on the triplet DM can be evaded by employing a larger mass gap of the order of 10 GeV which allows its mass larger than about 1 TeV. However, the future CTA experiment will be able to cover most of the unconstrained parameter space.Comment: 17 pages, 4 figures; result for an O(10 GeV) mass gap, future sensitivity of CTA, and references adde

Dynamics of Urban Centre and Concepts of Symmetry: Centroid and Weighted Mean

The city is a kind of complex system being capable of auto-organization of its programs and adapts a principle of economy in its form generating process. A new concept of dynamic centre in urban system, called "the programmatic moving centre”, can be used to represent the successive appearances of various programs based on collective facilities and their potential values. The absolute central point is substituted by a magnetic field composed of several interactions among the collective facilities and also by the changing value of programs through time. The center moves continually into this interactive field. Consequently, we introduce mathematical methods of analysis such as "the centroid” and "the weighted mean” to calculate and visualize the dynamics of the urban centre. These methods heavily depend upon symmetry. We will describe and establish the moving centre from a point of view of symmetric optimization that answers the question of the evolution and successive equilibrium of the city. In order to explain and represent dynamic transformations in urban area, we tested this programmatic moving center in unstable and new urban environments such as agglomeration areas around Lausanne in Switzerlan

Graceful Navigation for Mobile Robots in Dynamic and Uncertain Environments.

The ability to navigate in everyday environments is a fundamental and necessary skill for any autonomous mobile agent that is intended to work with human users. The presence of pedestrians and other dynamic objects, however, makes the environment inherently dynamic and uncertain. To navigate in such environments, an agent must reason about the near future and make an optimal decision at each time step so that it can move safely toward the goal. Furthermore, for any application intended to carry passengers, it also must be able to move smoothly and comfortably, and the robot behavior needs to be customizable to match the preference of the individual users. Despite decades of progress in the field of motion planning and control, this remains a difficult challenge with existing methods. In this dissertation, we show that safe, comfortable, and customizable mobile robot navigation in dynamic and uncertain environments can be achieved via stochastic model predictive control. We view the problem of navigation in dynamic and uncertain environments as a continuous decision making process, where an agent with short-term predictive capability reasons about its situation and makes an informed decision at each time step. The problem of robot navigation in dynamic and uncertain environments is formulated as an on-line, finite-horizon policy and trajectory optimization problem under uncertainty. With our formulation, planning and control becomes fully integrated, which allows direct optimization of the performance measure. Furthermore, with our approach the problem becomes easy to solve, which allows our algorithm to run in real time on a single core of a typical laptop with off-the-shelf optimization packages. The work presented in this thesis extends the state-of-the-art in analytic control of mobile robots, sampling-based optimal path planning, and stochastic model predictive control. We believe that our work is a significant step toward safe and reliable autonomous navigation that is acceptable to human users.PhDMechanical EngineeringUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/120760/1/jongjinp_1.pd

Bio-inspired Parametric Design for Adaptive Stadium Façades

The challenge of developing sustainable, adaptive architecture requires unconventional approaches to innovative knowledge about composition and dynamic interaction between building façades and environmental conditions. These approaches are often inspired by biology, its complex fine-tuned behaviour and integration of living systems. This paper proposes a system inspired from the optics of reflecting superposition compound eyes to create responsive façade structures that capture and distribute daylight within a building in response to the movement of the sun. This is investigated using the parametric reshaping of a building envelop as part of solar radiation and target ray simulations. The prototype façade system is capable of adapting to different functional needs, locations, times of the day, and other contextual conditions.Keywords: Biomimetics, kinetic/adaptive façades, reflecting superposition compound eye