Query inseparability by games

We investigate conjunctive query inseparability of description logic knowledge bases (KBs) with respect to a given signature, a fundamental problem for KB versioning, module extraction, forgetting and knowledge exchange. We develop a game-theoretic technique for checking query inseparability of KBs expressed in fragments of Horn-ALCHI, and show a number of complexity results ranging from P to ExpTime and 2ExpTime. We also employ our results to resolve two major open problems for OWL 2 QL by showing that TBox query inseparability and the membership problem for universal UCQ-solutions in knowledge exchange are both ExpTime-complete for combined complexity

Investigation of the vibration isolation of commercial jet transport pilots during turbulent air penetration

Electrohydraulic pilot seat isolation system of commercial transport pilots during turbulent air penetratio

GeMs/GSAOI observations of La Serena 94: an old and far open cluster inside the solar circle

Physical properties were derived for the candidate open cluster La Serena 94, recently unveiled by the VVV collaboration. Thanks to the exquisite angular resolution provided by GeMS/GSAOI, we could characterize this system in detail, for the first time, with deep photometry in JHK$_{s}$ - bands. Decontaminated JHK$_{s}$ diagrams reach about 5 mag below the cluster turnoff in H. The locus of red clump giants in the colour - colour diagram, together with an extinction law, was used to obtain an average extinction of $A_V =14.18 \pm 0.71$. The same stars were considered as standard - candles to derive the cluster distance, $8.5 \pm 1.0$ kpc. Isochrones were matched to the cluster colour - magnitude diagrams to determine its age, $\log{t(yr)}=9.12\pm 0.06$, and metallicity, $Z=0.02\pm0.01$. A core radius of $r_{c}=0.51\pm 0.04$ pc was found by fitting King models to the radial density profile. By adding up the visible stellar mass to an extrapolated mass function, the cluster mass was estimated as $M=(2.65\pm0.57) \times 10^3$ M$_{\odot}$, consistent with an integrated magnitude of $M_{K}=-5.82\pm0.16$ and a tidal radius of $r_{t}=17.2\pm2.1$ pc. The overall characteristics of La Serena 94 confirm that it is an old open cluster located in the Crux spiral arm towards the fourth Galactic quadrant and distant $7.30\pm 0.49$ kpc from the Galactic centre. The cluster distorted structure, mass segregation and age indicate that it is a dynamically evolved stellar system.Comment: 16 pages, 24 figures, 2 Tables, accepted by MNRAS; corrected typo

Geometric Hamilton-Jacobi Theory

The Hamilton-Jacobi problem is revisited bearing in mind the consequences arising from a possible bi-Hamiltonian structure. The problem is formulated on the tangent bundle for Lagrangian systems in order to avoid the bias of the existence of a natural symplectic structure on the cotangent bundle. First it is developed for systems described by regular Lagrangians and then extended to systems described by singular Lagrangians with no secondary constraints. We also consider the example of the free relativistic particle, the rigid body and the electron-monopole system.Comment: 40 page

Euler Polynomials and Identities for Non-Commutative Operators

Three kinds of identities involving non-commutating operators and Euler and Bernoulli polynomials are studied. The first identity, as given by Bender and Bettencourt, expresses the nested commutator of the Hamiltonian and momentum operators as the commutator of the momentum and the shifted Euler polynomial of the Hamiltonian. The second one, due to J.-C. Pain, links the commutators and anti-commutators of the monomials of the position and momentum operators. The third appears in a work by Figuieira de Morisson and Fring in the context of non-Hermitian Hamiltonian systems. In each case, we provide several proofs and extensions of these identities that highlight the role of Euler and Bernoulli polynomials.Comment: 20 page

Sensitive imaging of electromagnetic fields with paramagnetic polar molecules

We propose a method for sensitive parallel detection of low-frequency electromagnetic fields based on the fine structure interactions in paramagnetic polar molecules. Compared to the recently implemented scheme employing ultracold $^{87}$Rb atoms [B{\"o}hi \textit{et al.}, Appl. Phys. Lett. \textbf{97}, 051101 (2010)], the technique based on molecules offers a 100-fold higher sensitivity, the possibility to measure both the electric and magnetic field components, and a probe of a wide range of frequencies from the dc limit to the THz regime

Geometric Hamilton-Jacobi Theory for Nonholonomic Dynamical Systems

The geometric formulation of Hamilton--Jacobi theory for systems with nonholonomic constraints is developed, following the ideas of the authors in previous papers. The relation between the solutions of the Hamilton--Jacobi problem with the symplectic structure defined from the Lagrangian function and the constraints is studied. The concept of complete solutions and their relationship with constants of motion, are also studied in detail. Local expressions using quasivelocities are provided. As an example, the nonholonomic free particle is considered.Comment: 22 p

Energy loss through the steam trap in a steam system

This thesis is about the energy loss through the steam trap in the steam system. In industry, steam traps frequently fail but they are not noticed except when they are leaking. If steam trap fail in failed open, live steam can escape to surrounding. High amount of energy will loss from the steam system. It takes weeks or months before it being repaired or replaced. The first objective of this study is to measure the heat loss for normal thermodynamic steam trap in respond to operating pressure for different condensate load. The second objective is to measure the heat loss for failed open thermodynamic steam trap in respond to operating pressure for different condensate load. The last objective is to compare energy loss between normal and failed open steam trap. From the last objective, the actual energy loss if failed steam trap is not repaired is determined. Thermodynamic steam trap has been tested in the experiment and the operating pressure is below 1 bar. Condensate that discharges from steam trap is collected to record the reading of its temperature and weight. These data is used to determine the energy loss through the steam trap. For normal steam trap, energy loss for high condensate load is higher than low condensate load. For failed open steam trap, energy loss for high condensate load is lower than low condensate load. Finally, after comparing the result, steam system that has low condensate load has higher energy loss compare to high condensate load

Formal Verification of Pure Production Systems Programs

Reliability, defined as the guarantee that a program satisfies its specifications, is an important aspect of many applications for which rule-based expert systems are suited. Executing rule-based programs on a series of test cases. To show a program is reliable, it is desirable to construct formal specifications for the program and to prove that it obeys those specifications. This paper presents an assertional approach to the verification of a class of rule-based programs characterized by the absence of conflict resolution. The proof logic needed for verification is already in use by researchers in concurrent programming. The approach involves expressing the program in a language called Swarm, and its specifications as assertions over the Swarm program. Among models that employ rules-based notation, Swarm is the first to have an axiomatic proof logic. A brief review of Swarm and its proof logic is given, along with an illustration of the formal verification method used on a simple rule-based program

Formal Derivation of Rule-Based Program

This paper describes a formal approach to developing concurrent rule-based programs. Our program derivation strategy starts with a formal specification of the problem. Specification refinement is used to generate an initial version of the program. Program refinement is then applied to produce a highly concurrent and efficient version of the same program. Techniques for the deriving concurrent programs through either specification or program refinement have been described in previous literature. The main contribution of this paper consists of extending the applicability of these techniques to a broad class of rule-based programs. The derivation process is supported by a powerful proof logic, a logic that recently has been extended to cover rule-based programs. The presentation centers around a rigorous and systematic derivation of a concurrent rule-based solution to a classic problem