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关键词： Authorization   Complexity theory   Software   Business   Absorption   Software algorithms   Computer science   Authorisations   constraints   fixed parameter tractability   workflow satisfiability problem  

摘要： The workflow satisfiability problem (WSP) is a well-studied problem in access control seeking allocation of authorised users to every step of the workflow, subject to workflow specification constraints. It was noticed that the number kof steps is typically small compared to the number of users in the real-world instances of WSP;therefore k is considered as the parameter in WSP parametrised complexity research. While WSP in general was shown to be W[1]-hard, WSP restricted to a special case of user-independent (UI) constraints is fixed-parameter tractable (FPT). However, restriction to the UI constraints might be impractical. To efficiently handle non-UI constraints, we introduce the notion of branching factor of a constraint. As long as the branching factors of the constraints are relatively small and the number of non-UI constraints is reasonable, WSP can be solved in FPT time. Extending the results from Karapetyan et al. (2019), we demonstrate that general-purpose solvers are capable of achieving FPT-like performance on WSP with arbitrary constraints when used with appropriate formulations. This enables one to tackle most of practical WSP instances. While important on its own, we hope that this result will also motivate researchers to look for FPT-aware formulations of other FPT problems.

关键词： aggravating evidence   capital punishment   death penalty   jury decision-making   mitigating evidence  

摘要： The US Supreme Court has required that death penalty procedures narrow the class of persons eligible for a death sentence. Through the selection requirement, juries must use mitigating and aggravating evidence jointly to determine if a defendant is one of the worst of the worst, resulting in a sentence of life without parole or death. This study analyzed capital trial transcripts from the punishment phase to assess the type and amount of mitigating and aggravating evidence presented to jurors in cases resulting in life without parole and death. The main assumption of the research was that cases resulting in life without the possibility of parole (LWOP) would reveal patterns in the types of evidence presented and differing patterns in cases where the jury handed down a sentence of death. The study qualitatively examined the trial transcripts from the punishment phase of 18 capital murders (nine resulting in LWOP and nine in death). The extra-legal factors from each LWOP case were matched to a death case to eliminate sentencing discrepancies based on jurisdiction, race of defendant or victim, aggravator, age etc. The results found no consistent patterns of evidence presented in cases resulting life without parole and some relevant patterns in sentences resulting in death.

关键词： Computer science   Machine learning  

摘要： UK and US governments establish efforts to democratize access to supercomputers that will aid studies on AI systems.

关键词： Vaccines   Indexes   COVID-19   Pandemics   Analytical models   Social factors   Computer science   epidemic vulnerability index   agent-based model   clinical and social data analysis   simulation-based inference   statistical proliferation estimation   vaccine distribution strategy  

摘要： COVID-19 vaccine distribution route directly impacts the community's mortality and infection rate. Therefore, optimal vaccination dissemination would appreciably lower the death and infection rates. This paper proposes the Epidemic Vulnerability Index (EVI) that quantitatively evaluates the subject's potential risk. Our primary aim for the suggested index is to diminish both infection rate and death rate efficiently. EVI was accordingly designed with clinical factors determining the mortality and social factors incorporating the infection rate. Through statistical COVID-19 patient dataset analysis and social network analysis with an agent-based model that is analogous to a real-world system, we define and experimentally validate the capability of EVI. Our experiments consist of nine vaccination distribution scenarios, including existing indexes which estimate the risk and stochastically proliferate the contagion and vaccine in a 300,000 agent-based graph network. We compared the outcome and variation of the three metrics in the experiments: infection case, death case, and death rate. Through this assessment, vaccination by the descending order of EVI has shown to have a significant outcome with an average of 5.0% lower infection cases, 9.4% lower death cases, and 3.5% lower death rate than other vaccine distribution routes.

关键词： Computer science research   Geographical mobility of researchers   Correlation between geographical mobility and scientific productivity   Time evolution of mobility patterns  

摘要： In this article, we study the international mobility of researchers in the field of computer science (CS). Our analysis hinges upon Scopus data spanning a time period of 30 years (1991-2020) and involves a total of 969,835 researchers and 8,412,543 publications. Our contribution is two-fold. First, we characterize mobility as a fairly common phenomenon in CS, we highlight a strong correlation with standard bibliometric indicators at all seniority levels and a lower propensity of female researchers to relocate internationally than their male colleagues. Second, we analyze individual career paths building from them a mobility graph and identifying common patterns, such as the most traveled connections between different countries, whether they are equally traversed in both directions and the most frequently visited countries. The temporal evolution of the above patterns within our 30-year time frame is also investigated. The United States emerged as a preferred destination for internationally mobile authors, with strong connections to China (from the early 2000s), Canada, and several prominent European countries, most notably the United Kingdom, Germany, and France.

关键词： Computer Science   CS experiences   High school students   Predictors of future enrollment  

摘要： This study aims to examine the current experiences of high school students in computer science (CS) courses and the factors that motivated them to continue their future enrollment. The participants were 603 high school students in grades 9 through 12 in Indiana, all of whom enrolled in at least one CS course during the 2020-2021 academic year. This research revealed that fun and meaningful CS pedagogy, knowledgeable CS teachers, and relevance to their lives and future careers enabled high school students to hold positive experiences in their CS classes. These experiences impacted students to take additional CS courses. In addition to these positive experiences, gender and early exposure to CS emerge as predictors to pursue CS courses. The findings will carry significance for policymakers and educators offering insights to enhance and broaden students' participation and engagement in the CS course.

关键词： Visualization   Image synthesis   Generators   Generative adversarial networks   Electronic mail   Semantics   Computer science   Fine-grained generation   generative adversarial networks (GANs)   human poses   person image generation   text-to-image translation  

摘要： Person image generation conditioned on natural language allows us to personalize image editing in a user-friendly manner. This fashion, however, involves different granularities of semantic relevance between texts and visual content. Given a sentence describing an unknown person, we propose a novel pose-guided multi-granularity attention architecture to synthesize the person image in an end-to-end manner. To determine what content to draw at a global outline, the sentence-level description and pose feature maps are incorporated into a U-Net architecture to generate a coarse person image. To further enhance the fine-grained details, we propose to draw the human body parts with highly correlated textual nouns and determine the spatial positions with respect to target pose points. Our model is premised on a conditional generative adversarial network (GAN) that translates language description into a realistic person image. The proposed model is coupled with two-stream discriminators: 1) text-relevant local discriminators to improve the fine-grained appearance by identifying the region-text correspondences at the finer manipulation and 2) a global full-body discriminator to regulate the generation via a pose-weighting feature selection. Extensive experiments conducted on benchmarks validate the superiority of our method for person image generation.

关键词： Computer science   Information technology   Scientific data  

摘要： With the rapid development of blockchain technology, the financial and monetary (FM) blockchain fields also began to collide. Therefore, this study aims to explore the relationship between the two fields and efficiently evaluate the security of financial information. Firstly, this study introduces the theoretical basis of blockchain in the dynamic linkage mechanism of FM and gives the overall framework of digital currency based on blockchain. Meanwhile, the relationship between blockchain and digital finance is empirically analyzed and designed. Secondly, the framework of financial information service security assessment (ISSA) is created using blockchain technology, and the frame of security risk evaluation is verified by taking electronic invoice information as the research object. Finally, the results show that: (1) foreign exchange (forex) events and major stock index decline events have a significant impact on the return of Bitcoin (BTC) in the short term. Moreover, more than 70% of uncertainty events will make BTC's abnormal return (AR) significantly positive;(2) Under the influence of forex uncertainty events, only one BTC's AR is remarkably negative in short order, while the other seven times are markedly positive. In the uncertainty events of major stock indexes, only two times are significantly negative, and the other six times are positive. This indicates that uncertain events in the short run make prominent AR of BTC;the proposed blockchain-based ISSA model and assessment index are scientific, feasible, and operable.

关键词： Eye diseases   Computer science  

摘要： The objective of this retrospective study was to predict short-term efficacy of anti-vascular endothelial growth factor (VEGF) treatment in diabetic macular edema (DME) using machine learning regression models. Real-world data from 279 DME patients who received anti-VEGF treatment at Ineye Hospital of Chengdu University of TCM between April 2017 and November 2022 were analyzed. Eight machine learning regression models were established to predict four clinical efficacy indicators. The accuracy of the models was evaluated using mean absolute error (MAE), mean square error (MSE) and coefficient of determination score (R-2). Multilayer perceptron had the highest R-2 and lowest MAE among all models. Regression tree and lasso regression had similar R-2, with lasso having lower MAE and MSE. Ridge regression, linear regression, support vector machines and polynomial regression had lower R-2 and higher MAE. Support vector machine had the lowest MSE, while polynomial regression had the highest MSE. Stochastic gradient descent had the lowest R-2 and high MAE and MSE. The results indicate that machine learning regression algorithms are valuable and effective in predicting short-term efficacy in DME patients through anti-VEGF treatment, and the lasso regression is the most effective ML algorithm for developing predictive regression models.

关键词： Black girls   Computer science   Computational thinking   Dependent learning   Equity   Independent learning   Learning behaviors   Learning ecosystem   Middle school girls   STEM   STEM plus CS  

摘要： PurposeThere is a critical need to understand how to attract Black girls and other girls of color to the science, technology, engineering, math, and computer science (STEM+CS) field. This study aims to look at the design and implementation of a CS learning ecosystem that supports girls of color in acquiring critical CS skills starting in middle school. Design/methodology/approachThis mixed-method case study included 53 girls, between the ages of 11 and 13, in four US middle schools. Study methods included the analysis of a pre-program student survey, longitudinal interviews and focus groups, weekly observations and computing artifacts. FindingsProgram participants were interested in CS, were confident in their ability to learn CS, had prior coding and CS experience and had parents and teachers who encouraged them to learn CS. But some students showed dependent learning behaviors while engaging in CS activities. These included relying on instructors and being reticent to make mistakes-behaviors that limit learning. The CS learning ecosystem supported students as they shifted from applying dependent learning approaches to applying independent learning approaches. Instructors sustained a growth mindset and supported productive struggle as students learned CS skills. Originality/valueA CS learning system supported equitable learning experiences and helped students develop independent learning behaviors that led to deeper engagement in CS.