RNA secondary structure prediction using large margin methods

The secondary structure of RNA is essential for its biological role. Recently, Do, Woods, Batzoglou, (ISMB 2006) proposed a probabilistic approach that generalizes SCFGs using conditional maximum likelihood to estimate the model parameters. We propose an alternative approach to parameter estimation which is based on an SVM-like large margin method

The Generalized Dirichlet to Neumann map for the KdV equation on the half-line

For the two versions of the KdV equation on the positive half-line an initial-boundary value problem is well posed if one prescribes an initial condition plus either one boundary condition if $q_{t}$ and $q_{xxx}$ have the same sign (KdVI) or two boundary conditions if $q_{t}$ and $q_{xxx}$ have opposite sign (KdVII). Constructing the generalized Dirichlet to Neumann map for the above problems means characterizing the unknown boundary values in terms of the given initial and boundary conditions. For example, if $\{q(x,0),q(0,t) \}$ and $\{q(x,0),q(0,t),q_{x}(0,t) \}$ are given for the KdVI and KdVII equations, respectively, then one must construct the unknown boundary values $\{q_{x}(0,t),q_{xx}(0,t) \}$ and $\{q_{xx}(0,t) \}$, respectively. We show that this can be achieved without solving for $q(x,t)$ by analysing a certain ``global relation'' which couples the given initial and boundary conditions with the unknown boundary values, as well as with the function $\Phi^{(t)}(t,k)$, where $\Phi^{(t)}$ satisifies the $t$-part of the associated Lax pair evaluated at $x=0$. Indeed, by employing a Gelfand--Levitan--Marchenko triangular representation for $\Phi^{(t)}$, the global relation can be solved \emph{explicitly} for the unknown boundary values in terms of the given initial and boundary conditions and the function $\Phi^{(t)}$. This yields the unknown boundary values in terms of a nonlinear Volterra integral equation.Comment: 21 pages, 3 figure

Failure Analyses of Two Gas Turbine Wheels

AbstractThe results of the analysis of the catastrophic failures of two high pressure turbine wheels are discussed in this study. Fractographic and metallographic analyses on both the wheel and a set of failed blades of both wheels were performed to determine the possible events that led to failure. Both wheel materials had an austenitic microstructure, while blade materials were different for each case. One blade material is similar to INCONEL 738 nickel-based superalloy, while the other study is a single-crystal with dendritic growth microstructure. Facing two failures with apparently similar characteristics, once fractographic and metallographic analysis were performed, it was proved that failure modes respond to quite different origins in each case. This led to different corrective actions, according to each particular main contributing factor

Almost-stationary motions and gauge conditions in General Relativity

An almost-stationary gauge condition is proposed with a view to Numerical Relativity applications. The time lines are defined as the integral curves of the timelike solutions of the harmonic almost-Killing equation. This vector equation is derived by a variational principle, by minimizing the deviations from isometry. The corresponding almost-stationary gauge condition allows one to put the field equations in hyperbolic form, both in the free-evolution ADM and in the Z4 formalisms.Comment: Talk presented at the Spanish Relativity Meeting, September 6-10 2005 Revised versio

Localising iceberg inconsistencies

In artificial intelligence, it is important to handle and analyse inconsistency in knowledge bases. Inconsistent pieces of information suggest questions like “where is the inconsistency?” and “how severe is it?”. Inconsistency measures have been proposed to tackle the latter issue, but the former seems underdeveloped and is the focus of this paper. Minimal inconsistent sets have been the main tool to localise inconsistency, but we argue that they are like the exposed part of an iceberg, failing to capture contradictions hidden under the water. Using classical propositional logic, we develop methods to characterise when a formula is contributing to the inconsistency in a knowledge base and when a set of formulas can be regarded as a primitive conflict. To achieve this, we employ an abstract consequence operation to “look beneath the water level”, generalising the minimal inconsistent set concept and the related free formula notion. We apply the framework presented to the problem of measuring inconsistency in knowledge bases, putting forward relaxed forms for two debatable postulates for inconsistency measures. Finally, we discuss the computational complexity issues related to the introduced concepts

Preliminary realization of an electric-powered hydraulic pump system for a waste compactor truck and a techno-economic analysis

Most industrial trucks are equipped with hydraulic systems designed for specic operations, for which the required power is supplied by the internal combustion engine (ICE). The largest share of the power consumption is required by the hydraulic system during idling operations, and, consequently, the current literature focuses on energy saving strategies for the hydraulic system rather than making the vehicle traction more efficient. This study presents the preliminary realization of an electric-powered hydraulic pump system (e-HPS) that drives the lifting of the dumpster and the garbage compaction in a waste compactor truck, rather than traditional ICE-driven hydraulic pump systems (ICE-HPSs). The different components of the e-HPS are described and the battery pack was modelled using the kinetic battery model. The end-of-life of the battery pack was determined to assess the economic feasibility of the proposed e-HPS for the truck lifespan, using numerical simulations. The aim was twofold: To provide an implementation method to retrofit the e-HPS to a conventional waste compactor truck and to assess its economic feasibility, investigating fuel savings during the use phase and the consequent reduction of CO2 emissions. Results show that the total lifespan cost saving achieved a value of 65,000. Furthermore, total CO2 emissions for the e-HPS were about 80% lower than those of the ICE-HPS, highlighting that the e-HPS can provide significant environmental benefits in an urban context

Monitoring two small catchments to evaluate effects of no-tillage agricultural management in São Paulo state, Brazil.

In recent years, declines in water and soil quality have been observed in areas of Brazil where no-till agriculture had been previously implemented. Poor soil management associated with the absence of public policies has caused soil erosion, because many farmers are moving back from no-till to traditional cultivation for faster economic gains. A research project ? SoloVivo Project - leaded by Embrapa (Brazilian Agricultural Research Corporation) in partnership with Itaipu Binacional aims to develop and validate, in a participatory way, tools to evaluate the technical performance of soil and water management at the rural properties that practice notill agriculture. In this context we have selected two paired small (< 100 ha) catchments in the Paranapanema region, São Paulo State, where no-till management is practiced at two different degrees of effectiveness. In the figure bellow it can be seen a scene of one of the two studied catchments. For monitoring rainfall, soil solution and stream water, each catchment will be equipped with a programmable datalogger (with cell phone communication for data collection) linked to: a high intensity tipping bucket rain gage; a reflectometer to monitor soil volumetric water content, bulk electric conductivity and temperature; a radar water level sensor; a turbidity sensor; and an electric conductivity-temperature probe. We expect that stream flow and sediment generation, besides water quality (measured by conductivity) may serve as indicators of the benefits of no-tillage agriculture done more or less well. The results of this study will be used to stimulate discussions at workshops with the farmers who participate in a rural producers association in the region. In addition this and other results can be used to help the Brazilian National Water Agency (ANA) decide about applying no-till agricultural management systems in its programs of payment for environmental services

Quality Checks Logit Human Reliability (LHR): A New Model to Evaluate Human Error Probability (HEP)

In the years, several approaches for human reliability analysis (HRA) have been developed. The aim of the present research is to propose a hybrid model to evaluate Human Error Probability (HEP). The new approach is based on logit-normal distribution, Nuclear Action Reliability Assessment (NARA), and Performance Shaping Factors (PSFs) relationship. In the research, shortcomings related to literature approaches are analyzed, especially the limitations of the working time. For this reason, PSFs after 8 hours (work standard) during emergency conditions were estimated. Therefore, the correlation between the advantages of these three methodologies allows proposing a HEP analysis during accident scenarios and emergencies; a fundamental issue to ensure the safety and reliability in industrial plants is emergency Mmnagement (EM). Applying EM methodology, two main aspects are analyzed: system reliability and human reliability. System reliability is strongly related to the reliability of its weakest component. During incidental situations, the weakest parts of the whole system are workers (human reliability) and accidental scenarios influence the operator's ability to make decisions. This article proposes a new approach called Logit Human Reliability (LHR) that considers internal and external factors to estimate human reliability during emergencies. LHR has been applied in a pharmaceutical accident scenario, considering 24 hours of working time (more than 8 working hours). The results highlighted that the LHR method gives output data more in conformity with data banks than the conventional methods during the stress phase in an accident scenario