A rich hierarchy of functionals of finite types

We are considering typed hierarchies of total, continuous functionals using complete, separable metric spaces at the base types. We pay special attention to the so called Urysohn space constructed by P. Urysohn. One of the properties of the Urysohn space is that every other separable metric space can be isometrically embedded into it. We discuss why the Urysohn space may be considered as the universal model of possibly infinitary outputs of algorithms. The main result is that all our typed hierarchies may be topologically embedded, type by type, into the corresponding hierarchy over the Urysohn space. As a preparation for this, we prove an effective density theorem that is also of independent interest.Comment: 21 page

Comparing hierarchies of total functionals

In this paper we consider two hierarchies of hereditarily total and continuous functionals over the reals based on one extensional and one intensional representation of real numbers, and we discuss under which asumptions these hierarchies coincide. This coincidense problem is equivalent to a statement about the topology of the Kleene-Kreisel continuous functionals. As a tool of independent interest, we show that the Kleene-Kreisel functionals may be embedded into both these hierarchies.Comment: 28 page

Signaling in deterministic and stochastic settings

We contrast a standard deterministic signaling game with one where the signal-generating mechanism is stochastic. With stochastic signals a unique equilibrium emerges that involves separation and has intuitive comparative-static properties as the degree of signaling depends on the prior type distribution. With deterministic signals both pooling and separating configurations occur. Laboratory data support the theory: In the stochastic variant, there is more signaling behavior than with deterministic signals, and less frequent types distort their signals relatively more. Moreover, the degree of congruence between equilibrium and subject behavior is greater in stochastic settings compared to deterministic treatments. --experiments,learning,noise,signaling,stochastic environments

Job Market Signalling and Screening: An Experimental Comparison

We analyze the Spence education game in experimental markets.We compare a signaling and a screening variant, and we analyze the e®ect of increasing the number of employers from two to three.In all treatments, there is a strong tendency to separate.More efficient workers invest more often and employers bid higher for workers who have invested.More efficient workers also earn higher wages.Employers' pro¯ts are usually not different from zero.Increased competition leads to higher wages only in the signaling sessions.We ¯nd that workers in the screening sessions invest more often and earn higher wages when there are two employers.labour market;games

Gain control in molecular information processing: Lessons from neuroscience

Statistical properties of environments experienced by biological signaling systems in the real world change, which necessitate adaptive responses to achieve high fidelity information transmission. One form of such adaptive response is gain control. Here we argue that a certain simple mechanism of gain control, understood well in the context of systems neuroscience, also works for molecular signaling. The mechanism allows to transmit more than one bit (on or off) of information about the signal independently of the signal variance. It does not require additional molecular circuitry beyond that already present in many molecular systems, and, in particular, it does not depend on existence of feedback loops. The mechanism provides a potential explanation for abundance of ultrasensitive response curves in biological regulatory networks.Comment: 10 pages, 5 figure

Dipole Field, Tune and Chromaticity Correction at the SPS: from Converter Tracking to Eddy Currents

Good control of key parameters like dipole field, tune and chromaticity is a basic requirement for fast cycle commissioning and for good beam transmission through the SPS ramp. The reproducibility of those parameters depends on power converter tracking, eddy currents and remnant fields. The new SPS control system was used to study some of the problems in the low energy ramp segment of the fixed target beam. A small modification of the function generation for the main converters is shown to reduce residual converter tracking errors by more than one order of magnitude. Tune and chromaticity corrections have been analyzed and summarized for different cycles, both for the ramp as well for the injection plateau where eddy current may play a significant role

Charting service quality gaps

Some of the most influential models in the service management literature (Parasuraman et al., 1985; Grönroos, 1990) focus on the concept of service quality gap (SQG). Parasuraman et al. (1985) define a pioneering model with five SQGs, the concepts of which are amplified in Brogowicz et al.’s (1990) model. The latter has five types of encompassing gaps: information and feedback-related gaps; design-related gaps; implementation-related gaps; communication-related gaps; and customers’ perceptions and expectations related gaps. Additionally to this model amplification, other authors (e.g., Brown & Swartz, 1989) have pointed to relevant SQGs that have not been considered previously. This paper integrates current models and a group of SQGs dispersed through the literature in a new comprehensive model. It draws a link between the model and the stages of a strategy process, emphasising the SQGs’ impact on the process and raising relevant research questions.FCT, FEUALG, UALG

Computational interpretations of analysis via products of selection functions

We show that the computational interpretation of full comprehension via two wellknown functional interpretations (dialectica and modified realizability) corresponds to two closely related infinite products of selection functions