39,308 research outputs found
Log Skeletons: A Classification Approach to Process Discovery
To test the effectiveness of process discovery algorithms, a Process
Discovery Contest (PDC) has been set up. This PDC uses a classification
approach to measure this effectiveness: The better the discovered model can
classify whether or not a new trace conforms to the event log, the better the
discovery algorithm is supposed to be. Unfortunately, even the state-of-the-art
fully-automated discovery algorithms score poorly on this classification. Even
the best of these algorithms, the Inductive Miner, scored only 147 correct
classified traces out of 200 traces on the PDC of 2017. This paper introduces
the rule-based log skeleton model, which is closely related to the Declare
constraint model, together with a way to classify traces using this model. This
classification using log skeletons is shown to score better on the PDC of 2017
than state-of-the-art discovery algorithms: 194 out of 200. As a result, one
can argue that the fully-automated algorithm to construct (or: discover) a log
skeleton from an event log outperforms existing state-of-the-art
fully-automated discovery algorithms.Comment: 16 pages with 9 figures, followed by an appendix of 14 pages with 17
figure
Absence of Gluonic Components in Axial and Tensor Mesons
A quarkonium-gluonium mixing scheme previously developed to describe the
characteristic of the pseudoscalar mesons is applied to axial and tensor
mesons. The parameters of the model are determined by fitting the eigenvalues
of a mass matrix. The corresponding eigenvectors give the proportion of light
quarks, strange quarks and glueball in each meson. However the predictions of
the model for branching ratios and electromagnetic decays are incompatible with
the experimental results. These results suggest the absence of gluonic
components in the states of axial and tensor isosinglet mesons analyzed here.Comment: 12 page
2012 Census of California Water Transit Services ,MTI Report 12-02
The U.S. Bureau of Transportation Statistics conducts a nationwide census of ferry boat operators for the U.S. Department of Transportation and the collected information is used for statistical purposes. The Caltrans Division of Local Assistance has been asked by the Federal Highway Administration (FHWA) to gather data regarding ferry operations under MAP-21, the Moving Ahead for Progress in the 21st Century Act. MAP-21 includes a new formula program for ferry boats and ferry terminal facilities eligible under 23 USC 129(c) which authorizes federal participation in toll roads, bridges, tunnels, and ferries. FHWA has asked that Caltrans assure the ferry boat data is current for MAP-21. The Mineta Transportation Institute was contacted by Caltrans to conduct this research. The research team compiled a spreadsheet and accompanying maps that include ferry boats, routes, and operators along with a number of related characteristics including ownership (public or private), daily trip counts, regulation of fares, terminal locations (street address and coordinates), boarding statistics, and route segment lengths. The spreadsheet contains fields that will allow it to be linked in a Geographic Information System to Caltrans Earth software for further analysis. Additionally, where relevant, the report includes a brief description of expansion plans for certain ferry service providers
Understanding thio-effects in simple phosphoryl systems : role of solvent effects and nucleophile charge.
Recent experimental work (J. Org. Chem., 2012, 77, 5829) demonstrated pronounced differences in measured thio-effects for the hydrolysis of (thio)phosphodichloridates by water and hydroxide nucleophiles. In the present work, we have performed detailed quantum chemical calculations of these reactions, with the aim of rationalizing the molecular bases for this discrimination. The calculations highlight the interplay between nucleophile charge and transition state solvation in SN2(P) mechanisms as the basis of these differences, rather than a change in mechanism
Experimental Reexamination of Transverse Tensile Strength for IM7/8552 Tape-Laminate Composites
Due to the observed dependence of transverse-tensile strength, YT, on test geometry and specimen size, there is no consensus regarding a test method that can uniquely measure YT. This study reexamines characterization of YT by comparing results from established flexure tests with results from a new tensile test that exhibits consistent failure in the gage region. Additionally, the effects of surface preparation and direction of transverse fracture are investigated. Results show that YT is inversely proportional to specimen volume and surface roughness, and is insensitive to direction of transverse fracture. The relationship between specimen volume and YT is adequately captured by Weibull strength-scaling theory, except at the tails of the YT distributions. However, specimens exhibited microcracking prior to failure, which violates the weak-link assumptions of the Weibull theory. These findings highlight the challenges of using deterministic YT values in progressive damage analysis
Venture Capital as Human Resource Management
Venture capitalists add value to portfolio firms by obtaining and transferring information about senior managers across firms over time. Information transfer occurs on a significant scale and takes place both among a single venture capitalist%u2019s portfolio firms and between different venture capitalists%u2019 firms via a network of venture capitalists, which venture capitalists use to locate and relocate managers. Cross-sectional differences are associated with differences in the intensity with which venture capitalists network. The observable factors relevant in explaining the intensity with which venture capitalists network include: 1) the value of the information transmitted through the network, 2) the riskiness of the activities of portfolio firms, 3) the size of the venture capital fund, 4) the degree of difficulty in enticing executives to manage portfolio firms, and 5) the reputation of the venture capitalist for successfully recycling managers. These factors reflect costs and benefits to venture capitalists of participating in the network.
Berry phases and zero-modes in toroidal topological insulator
An effective Hamiltonian describing the surface states of a toroidal
topological insulator is obtained, and it is shown to support both bound-states
and charged zero-modes. Actually, the spin connection induced by the toroidal
curvature can be viewed as an position-dependent effective vector potential,
which ultimately yields the zero-modes whose wave-functions harmonically
oscillate around the toroidal surface. In addition, two distinct Berry phases
are predicted to take place by the virtue of the toroidal topology.Comment: New version, accepted for publication in EPJB, 6 pages, 1 figur
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