Qualitative Methods and Hybrid Maps for Spatial Perception with an Example of Security Perception

The security/insecurity of our cities has become the subject of public debate in recent years. The individual intuitions about security or insecurity can vary with age, gender, social background, personal constitution and previous positive or negative experiences. They are also constantly (re)produced, as perceptions of space are individual and selective. Noting these variations, materialised factors also play a major role, e.g., recessed house entrances, dense or high hedges, poor orientation options, dark places, etc. Attributing meaning to these materialised factors, real constructs are formed which create positive or negative narratives about certain (urban) spaces, influencing the actual use and design of urban spaces. To investigate the importance attached to certain spaces, qualitative methods are required for examining socio-spatial situations, perceptual processes and attribution. Using different methods in an explorative and in-depth descriptive research phase, such as expert interviews, user observations, surveys on go-alongs, participatory mapping with detailed information on structural and spatial locations, the advantages and disadvantages of method selection are presented. Berlin’s Alexanderplatz was used as a case study area to determine perceptions of security in urban areas. We confirmed that despite variations, certain subjective perceptions concerning visibility, brightness, and audibility are collective. Additionally, hybrid maps are used to explain how subjective perceptions of space, combined with 3D graphics, can alert architects and city planners to uncertainty among users of public space

Spin waves and Collisional Frequency Shifts of a Trapped-Atom Clock

We excite spin-waves with spatially inhomogeneous pulses and study the resulting frequency shifts of a chip-scale atomic clock of trapped $^{87}$Rb. The density-dependent frequency shifts of the hyperfine transition simulate the s-wave collisional frequency shifts of fermions, including those of optical lattice clocks. As the spin polarizations oscillate in the trap, the frequency shift reverses and it depends on the area of the second Ramsey pulse, exhibiting a predicted beyond mean-field frequency shift. Numerical and analytic models illustrate the observed behaviors.Comment: Will appear soon in Physical Review Letters - Typos correcte

An Example from Switzerland

This article is based on comparative anthropological fieldwork conducted in the Alpine region of Switzerland on sustainable environmental knowledge about natural hazards related to climate change. It examines ways to complement the normative and technological practices of risk management by using local knowledge to improve the resilience of affected communities against climate- related risks. The study shows how agricultural practices and knowledge may contribute to sustainable behavior towards nature and the environment. It explores how local environmental knowledge, perceptions, and handling strategies of climate-related risks may be integrated within a renewed concept of environmental sustainability. Participatory GIS mapping (PGIS) is the primary research method used. Based on applied visual anthropological methods, PGIS is a cartographical approach that integrates local perceptions and strategies of action drawn from interviews and participant observation. This approach enables improved communication of local knowledge and contributes to interdisciplinary cooperation between different academic fields, such as social anthropology, geography, and civil-engineering in the context of technological risk management. The approach encourages the active participation of local people in the process of sustainable risk management through the integration of cultural meanings and local knowledge about the sustainable management of sensitive natural environments

Fiber Fabry-Perot cavity with high finesse

We have realized a fiber-based Fabry-Perot cavity with CO2 laser-machined mirrors. It combines very small size, high finesse F>=130000, small waist and mode volume, and good mode matching between the fiber and cavity modes. This combination of features is a major advance for cavity quantum electrodynamics (CQED), as shown in recent CQED experiments with Bose-Einstein condensates enabled by this cavity [Y. Colombe et al., Nature 450, 272 (2007)]. It should also be suitable for a wide range of other applications, including coupling to solid-state emitters, gas detection at the single-particle level, fiber-coupled single-photon sources and high-resolution optical filters with large stopband.Comment: Submitted to New J. Phys

Bandwidth and conversion-efficiency analysis of Kerr soliton combs in dual-pumped resonators with anomalous dispersion

Kerr frequency combs generated in high-Q microresonators offer an immense potential in many applications, and predicting and quantifying their behavior, performance and stability is key to systematic device design. Based on an extension of the Lugiato-Lefever equation we investigate in this paper the perspectives of changing the pump scheme from the well-understood monochromatic pump to a dual-tone configuration simultaneously pumping two modes. For the case of anomalous dispersion we give a detailed study of the optimal choices of detuning offsets and division of total pump power between the two modes in order to optimize single-soliton comb states with respect to performance metrics like power conversion efficiency and bandwidth. Our approach allows also to quantify the performance metrics of the optimal single-soliton comb states and determine their trends over a wide range of technically relevant parameters

Humanökologie der Krisen: Systemische Annäherungen an COVID-19

Die COVID-19-Pandemie perturbiert alle gesellschaftlichen Sektoren und führt eindrücklich vor Augen, dass sie miteinander verwoben sind. Dieser Prozess lässt sich gut als Verhältnis von Resilienz und Vulnerabilität der Teilsysteme begreifen. Aus aktuellen human ökologischen Diskursen mit systemtheoretischem Fokus leiten wir zwei Rahmenmodel le zum Struktur- und Prozessverständnis der Pandemie und ihrer Effekte ab und stellen sie hier zur Diskussion