Corrected upper bounds for free-cut elimination

Free-cut elimination allows cut elimination to be carried out in the presence of non-logical axioms. Formulas in a proof are anchored provided they originate in a non-logical axiom or non-logical inference. This paper corrects and strengthens earlier upper bounds on the size of free-cut elimination. The correction requires that the notion of a free cut be modified so that a cut formula is anchored provided that all of its introductions are anchored, instead of only requiring that one of its introductions is anchored. With the correction, the originally proved size upper bounds remain unchanged. These results also apply to partial cut elimination. We also apply these bounds to elimination of cuts in propositional logic.If the non-logical inferences are closed under cut and infer only atomic formulas, then all cuts can be eliminated. This extends earlier results of Takeuti and of Negri and von Plato.     

Miniaturization and integration of photoacoustic detection with amicrofabricated chemical reactor system

Photoacoustic spectroscopy is a useful technique for monitoring chemical composition in mesoscale analysis systems because the detection limit scales favorably with miniaturization. The key element of a photoacoustic spectrometry system is the detector. This work focuses on the miniaturization of photoacoustic detection. In particular, we are using 3.4 μm light to detect propane in a carbon dioxide background-a system that is useful for monitoring combustion reactions. Two systems have been developed. In the first, a miniature photoacoustic cell has been machined into the mounting block of a microfabricated chemical reactor, demonstrating the integration of a photoacoustic detector with a microsystem. The cell used a hearing aid microphone and an infrared diode that was modulated at the first acoustic resonance of the cell. As the gas composition of the cell changed from carbon dioxide to propane the resonance peak was observed to shift and increase, as was expected from theory. This work also presents the first demonstration of a microfabricated photoacoustic detection cell. The cell used an optical microphone and laser excitation brought into the cell via an optical fiber. The light was modulated at a frequency far below the first acoustic resonance, and a signal of 0.05 Pa was observed in the presence of propane     

Multiple Comparisons in Induction Algorithms

A single mechanism is responsible for three pathologies of induction algorithms: attribute selection errors, overfitting, and oversearching. In each pathology, induction algorithms compare multiple items based on scores from an evaluation function and select the item with the maximum score. We call this a multiple comparison procedure (MCP). We analyze the statistical properties of MCPs and show how failure to adjust for these properties leads to the pathologies. We also discuss approaches that can control pathological behavior, including Bonferroni adjustment, randomization testing, and cross-validation.     

Evolution strategies with cumulative step length adaptation on the noisy parabolic ridge

This paper presents an analysis of the performance of the (μ/μ,λ)-ES with isotropically distributed mutations and cumulative step length adaptation on the noisy parabolic ridge. Several forms of dependency of the noise strength on the distance from the ridge axis are considered. Closed form expressions are derived that describe the mutation strength and the progress rate of the strategy in high-dimensional search spaces. It is seen that as for the sphere model, larger levels of noise present lead to cumulative step length adaptation generating increasingly inadequate mutation strengths, and that the problem can be ameliorated to some degree by working with larger populations.     

Effects of training to implement new tools and working methods to reduce knee load in floor layers

The purpose was to measure the effect of a participatory ergonomics implementation strategy consisting of information, education, and facilitation on the use of new tools and working methods in the floor laying trade. Floor layers (n=292) were trained in using new working methods. The effects were evaluated by using questionnaires, interviews, and assessments of quality and productivity. Following the training, 43% had used the new working methods weekly/daily compared to 11% before. There was a reduction in the degree of self-reported pain in the knees among the floor layers using the new working methods weekly or daily compared to those using them never or occasionally. The musculoskeletal complaints did not increase from any other region and the quality and the productivity of the work were not decreased. This indicates that within a 3-months perspective the implementation strategy succeeded.     

Simulation of cardiovascular system diseases by including the autonomic nervous system into a minimal model

Diagnosing cardiovascular system (CVS) diseases from clinically measured data is difficult, due to the complexity of the hemodynamic and autonomic nervous system (ANS) interactions. Physiological models could describe these interactions to enable simulation of a variety of diseases, and could be combined with parameter estimation algorithms to help clinicians diagnose CVS dysfunctions. This paper presents modifications to an existing CVS model to include a minimal physiological model of ANS activation. A minimal model is used so as to minimise the number of parameters required to specify ANS activation, enabling the effects of each parameter on hemodynamics to be easily understood. The combined CVS and ANS model is verified by simulating a variety of CVS diseases, and comparing simulation results with common physiological understanding of ANS function and the characteristic hemodynamics seen in these diseases. The model of ANS activation is required to simulate hemodynamic effects such as increased cardiac output in septic shock, elevated pulmonary artery pressure in left ventricular infarction, and elevated filling pressures in pericardial tamponade. This is the first known example of a minimal CVS model that includes a generic model of ANS activation and is shown to simulate diseases from throughout the CVS.     

Exploring the Interaction between Java's Implicitly Thrown Exceptions and Instruction Scheduling

The frequent occurrence of implicitly thrown exceptions poses one of the challenges present in a Java compiler. Not only do these implicitly thrown exceptions directly affect the performance by requiring explicit checks, they also indirectly impact the performance by restricting code movement in order to satisfy the precise exception model in Java. In particular, instruction scheduling is one transformation that is restricted by implicitly thrown exceptions due to the heavy reliance on reordering instructions to exploit maximum hardware performance. The goal of this study is two-fold: first, investigate the degree to which implicitly thrown exceptions in Java hinder instruction scheduling, and second, find new techniques for allowing more efficient execution of Java programs containing implicitly thrown exceptions. Experimental results show that with aggressive scheduling techniques, such as superblock scheduling, the negative performance impact can be greatly reduced.     

Optimum tracking with evolution strategies

Evolutionary algorithms are frequently applied to dynamic optimization problems in which the objective varies with time. It is desirable to gain an improved understanding of the influence of different genetic operators and of the parameters of a strategy on its tracking performance. An approach that has proven useful in the past is to mathematically analyze the strategy's behavior in simple, idealized environments. The present paper investigates the performance of a multiparent evolution strategy that employs cumulative step length adaptation for an optimization task in which the target moves linearly with uniform speed. Scaling laws that quite accurately describe the behavior of the strategy and that greatly contribute to its understanding are derived. It is shown that in contrast to previously obtained results for a randomly moving target, cumulative step length adaptation fails to achieve optimal step lengths if the target moves in a linear fashion. Implications for the choice of population size parameters are discussed.     

Quasiparticle tunneling through rare earth trihydroxide barriers

Symmetric tunneling junctions with 4000-Å-thick Pb electrodes and polycrystalline insulating barriers of Lu(OH)₃, Er(OH)₃, and Ho(OH)₃ have been fabricated. In bulk, these three rare earth trihydroxides are nonmagnetic, antiferromagnetic (T _N<1.1 K), and ferromagnetic (T_c=2.54 K), respectively. Tunneling resistances ranged from 600 to greater than 40,000 with a junction area of 6.25×10^–2 cm². Single-particle tunneling characteristics of these junctions were always broadened relative to the characteristics of Pb-PbO-Pb junctions, although the ratio of the zero-bias tunneling resistance to the normal tunneling resistance in some instances was of the order of 1000. A threefold splitting of the conductance peak at the gap was observed only in junctions with Ho(OH)₃ barriers. The gap peak of junctions with Er(OH)₃ barriers was broadened significantly relative to that of junctions with Lu(OH)₃ barriers. From measurements of the temperature and magnetic field dependences of the tunneling conductance it is argued that the splitting in junctions with Ho(OH)₃ barriers is consistent with the existence of a peak in the electronic density of states at an energy below that of the gap of each of the electrodes. This peak is believed to be the signature of a bound state near the barrier where the pair potential is depressed by virtue of the exchange coupling between the spins of the superconducting electrons and the localized spins of the barrier. Qualitative interpretations of the data support the view that the observed structure in Ho(OH)₃ barrier junctions is neither a consequence of intrinsic gap anisotropy in Pb nor of inelastic magnon-assisted tunnelling.     

Data encodings and their costs

Summary This paper is devoted to developing and studying a precise notion of the encoding of a logical data structure in a physical storage structure, that is motivated by considerations of computational efficiency. The development builds upon the notion of an encoding of one graph in another. The cost of such an encoding is then defined so as to reflect the structural compatibility of the two graphs, the (externally specified) costs of implementing the host graph, and the (externally specified) set of intended usage patterns of the guest graph. The stability of the constructed framework is demonstrated in terms of a number of results; the faithfulness of the formalism is argued in terms of a number of examples from the literature; and the tractability of the model is hinted at by several results and by further references to the literature.