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关键词： Benchmark testing   Optimization   Heuristic algorithms   Generators   Computer science   Performance analysis   Optimization methods   Continuous dynamic real-world problems   dynamic benchmark problems   evolutionary algorithms   future directions   performance indicators   unconstrained continuous dynamic optimization  

摘要： This article presents the second Part of a two-Part survey that reviews evolutionary dynamic optimization (EDO) for single-objective unconstrained continuous problems over the last two decades. While in the first part, we reviewed the components of dynamic optimization algorithms (DOAs);in this part, we present an in-depth review of the most commonly used benchmark problems, performance analysis methods, static optimization methods used in the framework of DOAs, and real-world applications. Compared to the previous works, this article provides a new taxonomy for the benchmark problems used in the field based on their baseline functions and dynamics. In addition, this survey classifies the commonly used performance indicators into fitness/error-based and efficiency-based ones. Different types of plots used in the literature for analyzing the performance and behavior of algorithms are also reviewed. Furthermore, the static optimization algorithms that are modified and utilized in the framework of DOAs as the optimization components are covered. We then comprehensively review some real-world dynamic problems that are optimized by EDO methods. Finally, some challenges and opportunities are pointed out for future directions.

关键词： Tools   Real-time systems   Task analysis   Education   Computer science   Cognition   Standards   Critical thinking   digital intervention   human-computer interaction design   mobile learning   research projects  

摘要： Digital behavior change interventions (DBCIs) provide customized advice, ongoing support, and Web- and mobile-based platforms for learners who want to change their undesirable behaviors. DBCIs have been successful in the past for delivering interventions that support sustained changes to health behaviors, such as disease prevention and health promotion. During research tasks, university students can require interventions associated with critical thinking skills and behaviors. By using a DBCI, educators can assist students with improving their learning skills in research projects. This study aims to understand student interactions and engagement with mobile-based DBCIs with the objective of improving their critical thinking skills. An experimental group was used to explore the effects of students' interactions with an engaging mobile-based DBCI with real-time feedback and it was designed using the LifeGuide Toolbox platform, which supports their critical thinking skills over a period of two months while they conduct a research project. A comparison between formative expert assessments and self-reported evaluation was also performed. This experiment reveals that using a DBCI to encourage critical thinking skills within a research project context can significantly improve engagement with intervention components, as well as recommend areas that require further exploration where specific critical thinking skills and digital interventions components are the most promising.

关键词： Task analysis   Sensors   Resource management   Crowdsensing   Mobile handsets   Computational modeling   Computer science   Assignment duration time   incentive mechanism   mobile crowdsensing (MCS)   truthful payment  

摘要： Mobile crowdsensing (MCS) has gained much attention due to the proliferation of smart devices equipped with powerful sensors. Large-scale users are the foundation of MCS, so designing incentive mechanisms to motivate users to participate in MCS is necessary. Existing works on incentive mechanisms usually assume a scenario where a group of tasks arrive at the platform at the same time and are immediately assigned to users. We argue that a more realistic MCS scenario can delay a task, which is called the assignment duration time, to wait for appropriate users. In this scenario, we focus on proposing a truthful incentive mechanism to reduce the overall social cost. Due to the uncertainty of coming users, the problems of selecting the appropriate users and calculating the payment for each recruited user (winner) are more complicated. To overcome these challenges, we design a dynamic truthful incentive mechanism (DTIM) including winner selection and payment decision processes. The former uniformly recruits users before the assignment deadline of tasks and dynamically readjusts the recruiting frequency of other tasks to select winners iteratively, which achieves an approximation ratio. Furthermore, the latter determines truthful payment for each winner to encourage user participation as well as avoid being deceived, which achieves truthfulness, individual rationality, and computational efficiency. Finally, massive simulations based on a real dataset roma/taxi validate the DTIM, which can effectively reduce the overall social cost and make a truthful payment for each winner.

关键词： Cloud computing   Maintenance engineering   Data models   Delays   Computer science   Social networking (online)   Power system reliability   Cloud storage   replication   data availability   cost-effectiveness  

摘要： Data availability is one of the most important performance factors in cloud storage systems. To enhance data availability, replication is a common approach to handle the machine failures. However, previously proposed replication schemes cannot effectively handle both correlated and non-correlated machine failures, especially while increasing the data availability with limited resources. The schemes for correlated machine failures must create a constant number of replicas for each data object, which often neglects diverse data popularities and does not utilize the resource to maximize the expected data availability. Also, the previous schemes neglect the consistency maintenance cost and the storage cost caused by replication. It is critical for cloud providers to maximize data availability (hence minimize SLA violations) while minimizing costs caused by replication in order to maximize the revenue. In this paper, we build a nonlinear integer programming model to maximize data availability in both types of failures, and therefore minimize the cost caused by replication. Based on the model's solution for the replication degree of each data object, we propose a low-cost multi-failure (correlated and non-correlated machine failures) resilient replication scheme (MRR). MRR can effectively handle both correlated and non-correlated machine failures, considers data popularities to enhance data availability, and also tries to minimize consistency maintenance and storage cost. Extensive numerical results from trace parameters and experiments from real-world Amazon S3 demonstrate that MRR achieves high data availability, low data loss probability and low consistency maintenance and storage costs when compared to previous replication schemes.

关键词： black soldier fly   amplicon sequencing   16S rRNA gene   culturable microbiome   genotyping   core microbiome   pathogen inhibition  

摘要： Black soldier fly larvae (BSFL) are fast-growing, resilient insects that can break down a variety of organic substrates and convert them into valuable proteins and lipids for applications in the feed industry. Decomposition is mediated by an abundant and versatile gut microbiome, which has been studied for more than a decade. However, little is known about the phylogeny, properties and functions of bacterial isolates from the BSFL gut. We therefore characterized the BSFL gut microbiome in detail, evaluating bacterial diversity by culture-dependent methods and amplicon sequencing of the 16S rRNA gene. Redundant strains were identified by genomic fingerprinting and 105 non-redundant isolates were then tested for their ability to inhibit pathogens. We cultivated representatives of 26 genera, covering 47% of the families and 33% of the genera detected by amplicon sequencing. Among these isolates, we found several representatives of the most abundant genera: Morganella, Enterococcus, Proteus and Providencia. We also isolated diverse members of the less-abundant phylum Actinobacteria, and a novel genus of the order Clostridiales. We found that 15 of the isolates inhibited at least one of the tested pathogens, suggesting a role in helping to prevent colonization by pathogens in the gut. The resulting culture collection of unique BSFL gut bacteria provides a promising resource for multiple industrial applications.

关键词： Optimization   Statistics   Sociology   Search problems   Convergence   Sorting   Computer science   Directed sampling (DS)   evolutionary multiobjective optimization   large-scale multiobjective problems (LSMOPs)   nondominated sorting   reference vectors  

摘要： It is particularly challenging for evolutionary algorithms to quickly converge to the Pareto front in large-scale multiobjective optimization. To tackle this problem, this article proposes a large-scale multiobjective evolutionary algorithm assisted by some selected individuals generated by directed sampling (DS). At each generation, a set of individuals closer to the ideal point is chosen for performing a DS in the decision space, and those nondominated ones of the sampled solutions are used to assist the reproduction to improve the convergence in evolutionary large-scale multiobjective optimization. In addition, elitist nondominated sorting is adopted complementarily for environmental selection with a reference vector-based method in order to maintain diversity of the population. Our experimental results show that the proposed algorithm is highly competitive on large-scale multiobjective optimization test problems with up to 5000 decision variables compared to five state-of-the-art multiobjective evolutionary algorithms.

关键词： Feature extraction   Roads   Convolution   Semantics   Benchmark testing   Computer science   Convolutional neural networks   Lane marking detection   structure-aware   deep neural network   intelligent transportation system  

摘要： Lane marking detection is a fundamental task, which serves as an important prerequisite for automatic driving or driver-assistance systems. However, the complex and uncontrollable driving road environment as well as the discontinuous lane marking appearance make this task challenging. In this work, a novel deep neural network architecture is presented to detect lane markings in a complex environment by analyzing their structure information. There are two contributions to the network design. Firstly, a semantic-guided channel attention (SGCA) module is developed to select the low-level features of a deep convolutional neural network by taking the high-level features as the guidance. Secondly, a pyramid deformable convolution (PDC) module is formulated to enlarge the receptive fields and to capture the complex structures of lane markings by applying deformable convolutions on multiple feature maps with different scales. Hence, our network can better reduce false detection and enhance lane marking structures simultaneously. The experimental results on three benchmark datasets for lane marking detection show that our method outperforms other methods on all the benchmark datasets.

关键词： Security   Cyber-physical systems   Cloud computing   Data privacy   Computer science   Anomaly detection   Monitoring  

摘要： N/A

关键词： black middle-class   cultural capital   Cultural consumption   elites   strategic assimilation  

摘要： This article provides a case study of race and big-gift cultural patronage, a theoretically and empirically understudied phenomenon, by investigating million-dollar donations to the Smithsonian Institution by black patrons. I find that large donations by black supporters are concentrated at one Smithsonian museum – the National Museum of African American History and Culture. To explain this distinctive pattern of cultural consumption, I draw on ethnographic data and archival texts related to patronage at African American museums. Gifts to the National Museum of African American History and Culture can be partly explained by strategic acculturation, or an impulse to articulate and nurture black identity through consuming black culture. However, cultural steering also played a key role. Black donors were identified and cultivated via a robust fundraising infrastructure where market research cast them as key constituents of the National Museum of African American History and Culture and taste-making strategies that constructed the museum as worthy reinforced their attraction to the museum. By conceptually and empirically elaborating cultural steering, this analysis offers a more complete model of black middle- and upper-class consumption of black culture. © The Author(s) 2019.

关键词： Students  

摘要： Proven practices to recruit domestic computer science graduate students.