The Swiss National Bank's monetary policy concept - an example of a 'principles-based' policy framework

The practice of monetary policy has evolved a great deal since the early 1990s. This evolution was significantly influenced by rapid developments in the theory of monetary policy. A new consensus about 'principles-based' monetary policy appears to be emerging. It marries a firm long-term anchor for nominal stability, rooted in the original ideas behind inflation targeting, with short-term flexibility, based on a more discretionary and pragmatic approach to monetary policy. The SNB's monetary policy framework - with a firm nominal anchor but with an emphasis on the need for flexibility - reflects, to a considerable degree, the emerging academic consensus about best-practice monetary policy. With its successful seven-year track record, it may serve as an interesting case study for a policy aiming at an intermediate position between full discretion and rigidly defined short-term inflation targeting.Swiss National Bank, monetary policy, inflation targeting, rules, discretion

Sources of productivity growth in the American coal industry

This paper develops new techniques to assess the expanse of the geographic market under varying supply and demand conditions and applies these techniques to the current wholesale electricity market in the western United States. This paper finds that, by and large, the expanse of the geographic market extends across most of the western United States, but that conditions which create congestion along transmission lines, such as high hydroelectric flows in the Pacific Northwest, transmission line outages and deratings, and high demand for wholesale electricity, cause the expanse of the geographic market to narrow at certain times.Supported by the MIT Center for Energy and Environmental Policy Research

Step size of the rotary proton motor in single FoF1-ATP synthase from a thermoalkaliphilic bacterium by DCO-ALEX FRET

Thermophilic enzymes can operate at higher temperatures but show reduced activities at room temperature. They are in general more stable during preparation and, accordingly, are considered to be more rigid in structure. Crystallization is often easier compared to proteins from bacteria growing at ambient temperatures, especially for membrane proteins. The ATP-producing enzyme FoF1-ATP synthase from thermoalkaliphilic Caldalkalibacillus thermarum strain TA2.A1 is driven by a Fo motor consisting of a ring of 13 c-subunits. We applied a single-molecule F\"orster resonance energy transfer (FRET) approach using duty cycle-optimized alternating laser excitation (DCO-ALEX) to monitor the expected 13-stepped rotary Fo motor at work. New FRET transition histograms were developed to identify the smaller step sizes compared to the 10-stepped Fo motor of the Escherichia coli enzyme. Dwell time analysis revealed the temperature and the LDAO dependence of the Fo motor activity on the single molecule level. Back-and-forth stepping of the Fo motor occurs fast indicating a high flexibility in the membrane part of this thermophilic enzyme.Comment: 14 pages, 7 figure

Microscopic approach to pion-nucleus dynamics

Elastic scattering of pions from finite nuclei is investigated utilizing a contemporary, momentum--space first--order optical potential combined with microscopic estimates of second--order corrections. The calculation of the first--order potential includes:\ \ (1)~full Fermi--averaging integration including both the delta propagation and the intrinsic nonlocalities in the $\pi$-$N$ amplitude, (2)~fully covariant kinematics, (3)~use of invariant amplitudes which do not contain kinematic singularities, and (4)~a finite--range off--shell pion--nucleon model which contains the nucleon pole term. The effect of the delta--nucleus interaction is included via the mean spectral--energy approximation. It is demonstrated that this produces a convergent perturbation theory in which the Pauli corrections (here treated as a second--order term) cancel remarkably against the pion true absorption terms. Parameter--free results, including the delta--nucleus shell--model potential, Pauli corrections, pion true absorption, and short--range correlations are presented. (2 figures available from authors)Comment: 13 page

Designing a virtual cockpit for helicopter offshore operations

In recent years the number of offshore wind farms is rapidly increasing. Especially coastal European countries are building numerous offshore wind turbines in the Baltic, the North, and the Irish Sea. During both construction and operation of these wind farms, many specially-equipped helicopters are on duty. Due to their flexibility, their hover capability, and their higher speed compared to ships, these aircraft perform important tasks like helicopter emergency medical services (HEMS) as well as passenger and freight transfer flights. The missions often include specific challenges like ship landings or hoist operations to drop off workers onto wind turbines. However, adverse weather conditions frequently limit offshore helicopter operations. In such scenarios, the adoption of aircraft-mounted sensors and obstacle databases together with helmet-mounted displays (HMD) seems to offer great potential to improve the operational capabilities of the helicopters used. By displaying environmental information in a visual conformal manner, these systems mitigate the loss of visual reference to the environment. This helps the pilots to maintain proper situational awareness (SA). This paper presents how our previously introduced concept of an HMD-based virtual flight deck can enhance offshore helicopter missions. The advantages of this system – for instance its “see-through the airframe”-capability and its highly-flexible cockpit instrument setup – enable us to design entirely novel pilot assistance systems. The work analyzes the specific requirements on our virtual cockpit so as to assist the helicopter crew in offshore-specific tasks. The gained knowledge is used to propose and evaluate concepts for a virtual cockpit that is tailor-made for helicopter offshore maneuvers