57,191 research outputs found

    Learning from accidents : machine learning for safety at railway stations

    Get PDF
    In railway systems, station safety is a critical aspect of the overall structure, and yet, accidents at stations still occur. It is time to learn from these errors and improve conventional methods by utilizing the latest technology, such as machine learning (ML), to analyse accidents and enhance safety systems. ML has been employed in many fields, including engineering systems, and it interacts with us throughout our daily lives. Thus, we must consider the available technology in general and ML in particular in the context of safety in the railway industry. This paper explores the employment of the decision tree (DT) method in safety classification and the analysis of accidents at railway stations to predict the traits of passengers affected by accidents. The critical contribution of this study is the presentation of ML and an explanation of how this technique is applied for ensuring safety, utilizing automated processes, and gaining benefits from this powerful technology. To apply and explore this method, a case study has been selected that focuses on the fatalities caused by accidents at railway stations. An analysis of some of these fatal accidents as reported by the Rail Safety and Standards Board (RSSB) is performed and presented in this paper to provide a broader summary of the application of supervised ML for improving safety at railway stations. Finally, this research shows the vast potential of the innovative application of ML in safety analysis for the railway industry

    Performance Analysis of a Dual-Hop Cooperative Relay Network with Co-Channel Interference

    Get PDF
    This paper analyzes the performance of a dual-hop amplify-and-forward (AF) cooperative relay network in the presence of direct link between the source and destination and multiple co-channel interferences (CCIs) at the relay. Specifically, we derive the new analytical expressions for the moment generating function (MGF) of the output signal-to-interference-plus-noise ratio (SINR) and the average symbol error rate (ASER) of the relay network. Computer simulations are given to confirm the validity of the analytical results and show the effects of direct link and interference on the considered AF relay network

    Reading the Number of Extra Dimensions in the Spectrum of Hawking Radiation

    Full text link
    After a brief review of the production and decay of Schwarzschild-like (4+n)-dimensional black holes in the framework of theories with Large Extra Dimensions, we proceed to derive the greybody factors and emission rates for scalars, fermions and gauge bosons on the brane. We present and discuss analytic and numerical methods for obtaining the above results, and demonstrate that both the amount and type of Hawking radiation emitted by the black hole can help us to determine the number of spacelike dimensions that exist in nature.Comment: 8 pages, Latex file, 1 figure, to appear in the proceedings of the String Phenomenology 2003 Conference, Durham, UK, 29th July-4th August, 200

    Vibrational Modes in LiBC: Theory Compared with Experiment

    Full text link
    The search for other superconductors in the MgB2 class currently is focussed on Li{1-x}BC, which when hole-doped (concentration x) should be a metal with the potential to be a better superconductor than MgB2. Here we present the calculated phonon spectrum of the parent semiconductor LiBC. The calculated Raman-active modes are in excellent agreement with a recent observation, and comparison of calculated IR-active modes with a recent report provides a prediction of the LO--TO splitting for these four modes, which is small for the B-C bond stretching mode at ~1200 cm^{-1}, but large for clearly resolved modes at 540 cm^{-1} and 620 cm^{-1}.Comment: 4 pages, two embedded figures. Physica B (in press

    INTERNATIONAL LAW ON THE IMPLEMENTATION OF THE SEA SHIP EXECUTION RELATED TO BAD CREDIT

    Get PDF
    Purpose: As ocean transportation instrument, the ocean vessel has an important role in improving the growth of economic rate, particularly naval economic business. The high cost of ocean vessel make businessmen difficult to acquire business capital, so they propose the application of credit and ocean vessel is made into mortgage. Although Indonesia is party in International Convention on Maritime Liens and Mortgages 1993, there is not any specific regulation arranging the execution of ocean vessel registered in Indonesia up to now. International Civil Law considers efforts to settle the issues must be started up by contract and agreement in advance. Based on the description, it is necessary to analyse to which extent International Civil Law might settle issues on the execution of ocean vessel and to which extent a court must pay attention and recognize foreign legal verdicts or rights emerged based on Foreign Court Verdicts or laws. Methodology: This study uses a normative juridical approach, the study of which refers to legal norms contained in the legislation, court decisions and legal norms that exist in society. The research specifications used are descriptive analytics. The sources of legal materials used are primary and secondary data and data collection techniques carried out by means of library research, interviews and observations. Meanwhile, the data analysis technique in this paper uses qualitative analysis. Main Findings:  An international agreement or agreement must contain a legal choice that will be used later because it will be a very complex problem if it is not determined from the beginning of the law which will be used if a dispute occurs. Ships that can be secured by mortgages are registered ships and ships weighing more than 20m3. In carrying out ship executions even though Indonesia has ratified the 1993 International Convention on Liens and Mortgage, the provisions for the execution of ships in Indonesia still refer to the provisions contained in Article 224 HIR or RIB and Article 258 Rbg. Implications/Applications: This study will be helpful for practitioners and law-making authorities in formulating different policies and amendments in existing international law on the implementation of the sea ship execution related to bad credit

    GHZ-type and W-type entangled coherent states: generation and Bell-type inequality tests without photon counting

    Get PDF
    We study GHZ-type and W-type three-mode entangled coherent states. Both the types of entangled coherent states violate Mermin's version of the Bell inequality with threshold photon detection (i.e., without photon counting). Such an experiment can be performed using linear optics elements and threshold detectors with significant Bell violations for GHZ-type entangled coherent states. However, to demonstrate Bell-type inequality violations for W-type entangled coherent states, additional nonlinear interactions are needed. We also propose an optical scheme to generate W-type entangled coherent states in free-traveling optical fields. The required resources for the generation are a single-photon source, a coherent state source, beam splitters, phase shifters, photodetectors, and Kerr nonlinearities. Our scheme does not necessarily require strong Kerr nonlinear interactions, i.e., weak nonlinearities can be used for the generation of the W-type entangled coherent states. Furthermore, it is also robust against inefficiencies of the single-photon source and the photon detectors.Comment: 8 pages, 5 figures, to be published in Phys. Rev.

    Microlensing Characterization of Wide-Separation Planets

    Full text link
    With their excellent photometric precision and dramatic increase in monitoring frequency, future microlensing survey experiments are expected to be sensitive to very short time-scale, isolated events caused by free-floating and wide-separation planets with mass as low as a few lunar masses. We estimate the probability of measuring the Einstein radius \theta_E for bound and free-floating planets. We carry out detailed simulations of the planetary events expected in next-generation surveys and estimate the resulting uncertainty in \theta_E for these events. We show that, for main-sequence sources and Jupiter-mass planets, the caustic structure of wide-separation planets with projected separations of < 20 AU substantially increases the probability of measuring the dimensionless source size and thus determining \theta_E compared to the case of unbound planets. In this limit where the source is much smaller than the caustic, the effective cross-section to measure \theta_E to 10% is ~25% larger than the full width of the caustic. Measurement of the lens parallax is possible for low-mass planetary events by combined observations from the ground and a satellite located in an L2 orbit; this would complete the mass measurements for such wide-separation planets. Finally, short-duration events caused by bound planets can be routinely distinguished from those caused by free-floating planets for planet-star separations < 20 AU from either the deviations due to the planetary caustic or (more often) the low-amplitude bump from the magnification due to the parent star.Comment: 10 pages including 7 figures. ApJ, in pres

    Ku-band system design study and TDRSS interface analysis

    Get PDF
    The capabilities of the Shuttle/TDRSS link simulation program (LinCsim) were expanded to account for radio frequency interference (RFI) effects on the Shuttle S-band links, the channel models were updated to reflect the RFI related hardware changes, the ESTL hardware modeling of the TDRS communication payload was reviewed and evaluated, in LinCsim the Shuttle/TDRSS signal acquisition was modeled, LinCsim was upgraded, and possible Shuttle on-orbit navigation techniques was evaluated
    • …
    corecore