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关键词： computer science   programming languages   IBM   Algol   Fortran   Cobol  

摘要： There probably has never been such a controversial programming language as Algol. In the early 1960s the disciplinary success of the so-called Algol project in helping to forge the discipline of computer science was not matched by a significant adoption of the Algol language, in any of its three versions. This contrast is even more striking when considering the contemporary success of IBM's Fortran, a language that, like Algol, was also conceived for scientific computation, but unlike Algol, initially only available for IBM computers. Through extensive archival research, this article shows how the relentless pursuit of a still better language that came to dominate the agenda of the Algol project brought to the fore the tension between the research-driven dimension of the project and the goal of developing a reliable programming language. Such a strong research-oriented agenda increased IBM's doubts about a project that the firm already felt little urge to support. Yet IBM did not want to appear as obstructing the development of either Algol or Cobol, even if these "common languages" posed a clear risk to the firm's marketing model. The US Department of Defense's endorsement of Cobol and the rising popularity of Algol in Europe convinced IBM to push for the use of Fortran in Western Europe in order to protect the domestic market. IBM's action in support of Fortran reminds us of the power imbalances that have shaped computer science.

关键词： Early childhood   Computer science   Programming app   Educational settings   Quantitative analysis   Learning analytics  

摘要： With a growing number of ScratchJr usage, over 19 million users worldwide, we examined the use in the United States of the free ScratchJr programming language, explicitly designed for young children ages 5-7, to learn how to code. Our objective was to explore children's usage of the ScratchJr tablet app at home and school settings. We analyzed usage data from Google Analytics in 1.5 years, comparing Scratchsr usage in the two different settings. Our dataset comprised a total of 4,352,802 coding sessions, generated by a daily average of 2525 home users and 9969 school users. The results suggested that, although children in both settings on average spent an equal duration with ScratchJr, children in home settings spent more time exploring advanced coding blocks and the paint editor compared to children at school. Further, children at school tended to use similar types of coding blocks across several days. In contrast, children at home were more likely to use a diversity of block categories and difficulty levels. The implications of this research are, first, that usage patterns may help us understand how children across settings learn to program differently. Second, based on these findings, it may be essential for parents at home and educators at school to consider using different approaches and strategies.

关键词： CS education   SPE   teacher learning   student learning   sociocultural views of learning   intersectionality   nepantla   emotionality   dis   ability  

摘要： This article advocates for the intersectional rights of teachers and students of computer science (CS) and special education (SPE) in urban education. Using an intersectional nepantla lens, we propose that CS education be accessible to all SPE teachers and students with dis/abilities. We argue for a focus on social-emotional intersectional rights as crucial foundations for an equitable approach to teaching and learning in CS SPE. We end with implications for educational stakeholders and teacher education programs that open pathways for socioemotional and intersectional rights of underrepresented teachers and students of CS and SPE.

关键词： Security   Cloud computing   Network slicing   5G mobile communication   Ecosystems   Symbiosis   Computer science   Cyber security   MTD   mimic defense   cloud native   network functions virtualization (NFV)   software defined network (SDN)   network slicing  

摘要： With the emergence of cloud native technology, the network slicing enables automatic service orchestration, flexible network scheduling and scalable network resource allocation, which profoundly affects the traditional security solution. Security is regarded as a technology independent of the cloud native architecture in the initial design, traditional passive defense such as "reinforced" and "stacked" is relied on to achieve system security protection. The lack of intrinsic security mechanisms makes the system capability insufficient when faces the uncertain threat brought by vulnerabilities and backdoors under the ecosystem of opening-up and sharing. The static nature of existing networks and computing systems makes them easy to be compromised and hard to defend, and thus it is urgent to provide intrinsic security and proactive protection against the unpredictable attacks. To this end, this paper proposes a novel paradigm named intrinsic cloud security (iCS) from the perspective of dynamic defense. The dynamic defense provides component-level security, and has complementary and consistency with the cloud native environment. In particular, iCS introduces mimic defense and moving target defense (MTD), and makes full use of the new features introduced by cloud native to implement an intrinsic and proactive defense mechanism with acceptable costs and efficiency. The iCS paradigm achieves seamless integration and symbiosis evolution between security and cloud native. We implement a trial of iCS based on 5GC commercial system and evaluate its performance on costs, efficiency and attack success. The result shows that the iCS enhanced mode always can provide a better and more stable defense effects.

关键词： Gender   Sexualities   Aging   Intimate relationships   Life course  

摘要： Research on aging and sexuality has proliferated in recent years. However, little is known about the genderspecific effects of aging on dating and sexuality. Using survey data from the 2014 wave of Singles in America (SIA), a comprehensive survey on adult singles' experiences with dating and sexuality, we examine whether age differentially affects heterosexual women's and men's dating and sexual attitudes and behaviors and whether gender differences persist across the life course. We find that men remain active in the dating and sexual marketplace longer than women. Although main effects of gender differences are documented in dating and sexual attitudes and behaviors, the results show that gender does not operate the same across the life course. Notably, gender differences shrink or are eliminated in attitudes and behaviors surrounding partnering in midlife and late adulthood, suggesting that age is integral to understanding gendered heterosexuality.

关键词： autism research   COVID-19   early career researchers  

摘要： The COVID-19 pandemic has disrupted autism research and services. Early career researchers (ECRs) are particularly vulnerable to the impact of the pandemic on job security and career development. The goal of this study was to capture the challenges ECRs are facing during the pandemic and the supports that are needed for career development and research. ECRs were invited to complete an online survey that focused on four major areas;the impact of COVID-19 on their research;changes in productivity due to COVID-19;changes to training due to COVID-19;and current mental health. 150 ECRs were eligible and provided sufficient data for inclusion. All but one ECRs reported their research had been negatively impacted by the pandemic. Reductions in productivity were reported by 85% of ECRs. The biggest impacts included recruitment of participants, increased needs at home and personal mental health. ECRs reported a 3-fold increase in burnout, as well as increased anxiety. ECR supports, such as funding, flexibility, and tenure extensions, are required to ensure ASD research does not suffer from a "lost generation" of researchers. Lay Summary: The COVID-19 pandemic has had negative impacts on research around the world. Loss of productivity impedes autism research discoveries. However, researchers in the earliest phases of their career, specifically postdoctoral fellows through individuals in assistant professor (or equivalent) positions, are particularly vulnerable to long-lasting effects of pandemic-related disruptions which may limit their ability to continue as autism researchers. This survey highlights the needs of this group and identifies mechanisms by which these early career researchers may be supported in this time. This is critical to ensure the next generation of ASD researchers and clinician scientists continue on the path to advancing understanding of autism in the decades to come.

关键词： Economics   Vehicular ad hoc networks   Game theory   Games   Computer science   Throughput   Stability analysis   VANET   Incentive Mechanism   Behavioral Economics   Anchoring Effect  

摘要： Vehicular Ad-hoc NETwork (VANET) is a wireless self-organized network composed of vehicles and Road Side Units (RSUs) providing users services. There are problems such as difficulty in maintaining end-to-end links between vehicles and RSUs, and limited bandwidth and channel resources. Incentive mechanisms are necessary to attract a sufficient number of vehicles to participate in data forwarding and share resources efficiently among vehicles in order to solve the above problems. There are two decision-making stages for a node. In the initial stage, a new node that has never participated decides whether to participate;in the following stage, the participating nodes decide whether to participate again. The current incentive mechanisms are based on traditional economics, which have two problems: 1) the role of anchors (that is, reference points) is not considered in both decision-making stages;2) using the same utility function to evaluate two different decision-making stages which are actually affected by two different anchors. However, anchoring effect in behavioral economics has proved that people make decisions based on the experience of others (called Experimenter-Provided Anchoring, EPA) when they are first time to participate in data forwarding. They rely on their own experience (called Self-Generated Anchoring, SGA) when they already have forwarding experience. Therefore, the users' decision-making in the existing incentive mechanisms deviates from reality. Based on anchoring effect, we propose a Dual-Process Mechanism (DPM), which includes the user Attraction mechanism based on Experimenter-Provided Anchoring (AEPA) and the user Continuous Working mechanism based on Self-Generated Anchoring (CWSGA). AEPA is used to motivate those new nodes to participate in data forwarding. CWSGA is used to motivate those nodes which have participated to forward data again. Simulations show that DPM has a 10% increase in cooperation rate compared with the currently most used in

关键词： Science education   Complex systems   Computer models   Multiple representations   Physical laboratories  

摘要： How do different components of a learning environment contribute to learning in science? The study examines the contribution of laboratory experiments and computer model explorations to the learning of chemistry through a complex-systems approach. Specifically, junior high-school students' learning of chemistry via four different methods were compared: with computer models using a complexity approach (MC);with laboratory experiments using a complexity approach (LC);with computer models and laboratory experiments using a complexity approach (MLC);and with a normative disciplinary approach that included only laboratory experiments (LN). Learning was tracked for the relevant science concepts, such as pressure, and for system component ideas, such as emergence. One hundred and fifty-nine seventh-grade students participated in a non-randomized four-group comparison quasi-experimental pre-test-intervention-post-test design with identical pre- and post-tests spaced 2-3 weeks apart. The learning activities for all modes were twelve 45-min lessons. Students' scores rose in all four groups, but to a different extent, showing a distinct and strong advantage to combining models and labs (MLC), while no differences were seen between the MC and LC conditions. There was also an advantage to learning with the complexity approach (LC) compared to learning using the normative approach (LN). More importantly, the specific concepts that were learned show distinct patterns, distinguishing the contributions of each learning environment component. These research findings have both practical implications when designing learning environments and theoretical contributions to understanding the necessary role of different experiences in learning science.

关键词： Fuzzy sets   Gravity   1   f noise   Computer science   Uncertainty   Computational complexity   Center of gravity (COG)   defuzzification   interval type-2 fuzzy set (IT2FS)   Nie-Tan defuzzifier   polygonal fuzzy set  

摘要： Defuzzification plays an important role in the applications of interval type-2 fuzzy sets (IT2FSs). However, computational complexity of existing defuzzification methods has turned this procedure into an important bottleneck toward the use of IT2FSs. It has been proved that the Nie-Tan method is an accurate discretizing-based method for calculating the center of gravity (COG) of IT2FSs. In this article, we propose a fast and accurate method for calculating the COG-Nie-Tan defuzzification-of polygonal IT2FSs on discrete and continuous domains without the need of discretization. The proposed method calculates the accurate COG for trapezoidal and triangular IT2FSs as special cases of polygonal IT2FSs. Moreover, any IT2FS can be approximated by a polygonal IT2FS-the higher the order of polygonal IT2FS, the better the approximation. Hence, using the proposed method on an IT2FS that is approximated by an appropriate polygonal IT2FS results in a more accurate COG.