338 research outputs found

    Safety Analysis of Level Crossing Surveillance Systems Using Fuzzy Petri Nets

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    [[abstract]]A backward safety analysis model that can deal with dangerous status by virtue of fuzzy theory is proposed in this paper. Fuzzy Petri Nets (FPN) is developed and applied to the safety analysis for three types of level crossing surveillance systems of Taiwan Railway Administration. The numerical results of proposed FPN models are fairly plausible.[[conferencetype]]國際[[conferencedate]]20081219~20081221[[conferencelocation]]Taipei, Taiwa

    A Modified Decomposed Theory of Planned Behaviour Model to Analyze User Intention towards Distance-Based Electronic Toll Collection Services

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    This study proposes a modified decomposed theory of planned behaviour model (DTPB) that integrates satisfaction and trust into the original DTPB model to explore what kind of factors affect the user intention towards distance-based electronic toll collection (ETC) services. The proposed model is empirically tested by using data collected from a questionnaire survey with a computer assisted telephone interview system. Empirical analysis is carried out in three stages that combine confirmatory factor analysis, structural equation modelling (SEM), and Bayesian network: (1) examination of reliability and validity of the measurement model; (2) analysis of structural model; (3) prediction of the probability of user intention change based on rigorous framework of SEM. The results confirm that the satisfaction and trust have positive effects on the behaviour intention, also validating that five constructs have indirect effects on the behaviour intention through attitude and perceived behaviour control. Compatibility is the most important influence factor, followed by perceived usefulness, facilitating conditions, self-efficacy, and perceived ease of use. The findings of this study identify potential improvements for ETC operator, such as contributing to the society to enhance the company image and trust of enterprise with charity activities, and simultaneously upgrading the information platform of website, software, and Apps.</p

    A Probability Model for Analysis of Attacks on Blockchain

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    In a blockchain, the longest chain, which has the greatest proof-of-work effort spent in it, represents the majority decision. To change the transaction data of a block, an attacker has to control more computing power than other honest nodes. This situation can happen if the attacker can hack into the systems of honest nodes. To analyze the probability of such event, we propose a probability model for analysis of attacks on blockchain. The model is based on the structure of a peer-to-peer network. We assume the state of each honest node follows a two-state (hacked or normal) Markov chains. A hacked node is assumed to be controlled by the attacker and its computing power belongs to the attacker. On the other hand, the computing power of a normal node belongs to the honest longest chain. We apply the model to study the probability of the majority decision is controlled by the attacker and the duration of such event. In addition, we analyze the magnitude of the loss for such event

    Optimal Outsourcing Strategy: a Stochastic Optimization Approach

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    As the production capacity of a company over a certain period of time is limited, enterprises must carefully consider product line development or outsourcing options. Unlike traditional studies that use static or comparative static analyses to determine optimal production strategies, this paper proposes a stochastic optimization model that can be used to determine optimum quantities of multiphase development or outsourcing. The proposed model can be used as a decision framework for future production allocation in high-tech industries that face uncertain demands. It can also be used as a financial projection tool

    NumHG: A Dataset for Number-Focused Headline Generation

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    Headline generation, a key task in abstractive summarization, strives to condense a full-length article into a succinct, single line of text. Notably, while contemporary encoder-decoder models excel based on the ROUGE metric, they often falter when it comes to the precise generation of numerals in headlines. We identify the lack of datasets providing fine-grained annotations for accurate numeral generation as a major roadblock. To address this, we introduce a new dataset, the NumHG, and provide over 27,000 annotated numeral-rich news articles for detailed investigation. Further, we evaluate five well-performing models from previous headline generation tasks using human evaluation in terms of numerical accuracy, reasonableness, and readability. Our study reveals a need for improvement in numerical accuracy, demonstrating the potential of the NumHG dataset to drive progress in number-focused headline generation and stimulate further discussions in numeral-focused text generation.Comment: NumEval@SemEval-2024 Datase

    Craniometrics reveal "two layers" of prehistoric human dispersal in eastern Eurasia

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    This cranio-morphometric study emphasizes a "two-layer model" for eastern Eurasian anatomically modern human (AMH) populations, based on large datasets of 89 population samples including findings directly from ancient archaeological contexts. Results suggest that an initial "first layer" of AMH had related closely to ancestral Andaman, Australian, Papuan, and Jomon groups who likely entered this region via the Southeast Asian landmass, prior to 65–50 kya. A later "second layer" shared strong cranial affinities with Siberians, implying a Northeast Asian source, evidenced by 9 kya in central China and then followed by expansions of descendant groups into Southeast Asia after 4 kya. These two populations shared limited initial exchange, and the second layer grew at a faster rate and in greater numbers, linked with contexts of farming that may have supported increased population densities. Clear dichotomization between the two layers implies a temporally deep divergence of distinct migration routes for AMH through both southern and northern Eurasia

    The histone H3K36 demethylase Rph1/KDM4 regulates the expression of the photoreactivation gene PHR1

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    The dynamics of histone methylation have emerged as an important issue since the identification of histone demethylases. We studied the regulatory function of Rph1/KDM4 (lysine demethylase), a histone H3K36 demethylase, on transcription in Saccharomyces cerevisiae. Overexpression of Rph1 reduced the expression of PHR1 and increased UV sensitivity. The catalytically deficient mutant (H235A) of Rph1 diminished the repressive transcriptional effect on PHR1 expression, which indicates that histone demethylase activity contributes to transcriptional repression. Chromatin immunoprecipitation analysis demonstrated that Rph1 was associated at the upstream repression sequence of PHR1 through zinc-finger domains and was dissociated after UV irradiation. Notably, overexpression of Rph1 and H3K36A mutant reduced histone acetylation at the URS, which implies a crosstalk between histone demethylation and acetylation at the PHR1 promoter. In addition, the crucial checkpoint protein Rad53 acted as an upstream regulator of Rph1 and dominated the phosphorylation of Rph1 that was required for efficient PHR1 expression and the dissociation of Rph1. The release of Rph1 from chromatin also required the phosphorylation at S652. Our study demonstrates that the histone demethylase Rph1 is associated with a specific chromatin locus and modulates histone modifications to repress a DNA damage responsive gene under control of damage checkpoint signaling

    The Sirtuin Family Members SIRT1, SIRT3 and SIRT6: Their Role In Vascular Biology and Atherogenesis

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    The sirtuins, silent mating-type information regulation 2 (SIRTs), are a family of nicotinamide adenine dinucleotide (NAD+)-dependent histone deacetylases with important roles in regulating energy metabolism and senescence. Activation of SIRTs appears to have beneficial effects on lipid metabolism and antioxidants, prompting investigation of the roles of these proteins in atherogenesis. Although clinical data are currently limited, the availability and safety of SIRT activators such as metformin and resveratrol provide an excellent opportunity to conduct research to better understand the role of SIRTs in human atherosclerosis. Encouraging observations from preclinical studies necessitate rigorous large, prospective, randomized clinical trials to determine the roles of SIRT activators on the progression of atherosclerosis and ultimately on cardiac outcomes, such as myocardial infarction and mortality
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