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关键词： Education computing  

摘要： Data on CS graduation rates among six academic institutions in NC traces the demographics of those participating (or not) in the discipline.

关键词： Botnet   Internet of Things   Mathematical model   Malware   Heuristic algorithms   Computer science   Security   Botnet propagation   identification ability   Internet of Things (IoT)   spread capability  

摘要： The existence of botnet puts people in an extremely insecure environment, which has seriously affected the development of Internet of Things (IoT). In order to prevent the formation of a botnet, it is necessary to understand the propagation behaviors and influence factors. As IoT devices become more intelligent, they can gradually generate social characteristics by mimicking human behaviors. However, in the process of coping with the botnet problem, little consideration has been given to the potential social characteristics of IoT. In this article, we build a dynamic botnet propagation model (i.e., IoT-BSI model) to study the influences of two social characteristics (i.e., device's spread capability and device's identification ability) on botnet formation. First, in terms of device's spread capability, this article makes great improvements on the K- shell decomposition algorithm and calculates this characteristic more accurately. Second, this article divides the device's identification ability into the rational identification ability and the irrational identification ability based on the sociological theory, and the calculation of the former is mainly realized by utilizing the PageRank idea. Third, this article applies the mean-field equation theory to analyze the dynamic characteristics of botnet propagation theoretically. Finally, the comprehensive results show that our model is not merely more consistent with the actual situation but also performs better than four compared models.

关键词： In vitro cultures   Phenylalanine   Cinnamic acid   Benzoic acid   Caffeic acid   Phenolic acids  

摘要： Agitated shoot cultures of two aronias,Aronia melanocarpa(Michx.) Elliott andAronia arbutifolia(L.) Pers., were maintained on Murashige & Skoog medium (1 mg/l BA and 1 mg/l NAA), both with and without the addition of various biosynthetic precursors of phenolic acids and depsides (phenylalanine, cinnamic acid, benzoic acid and caffeic acid). Each substance was added in 5 concentrations (0.1-10 mmol/l), each concentration at two time points (at the beginning and on the 10th day of cultures). Twenty-four phenolic acids were determined in methanolic extracts of the biomasses collected after 20 days of growth cycles by means of HPLC method with DAD detection. The presence of seven compounds was confirmed in all the extracts-five depsides (neochlorogenic, chlorogenic, cryptochlorogenic, isochlorogenic and rosmarinic acids), and syringic and caffeic acids. The main metabolites inA. melanocarpashoot extracts were isochlorogenic, chlorogenic and neochlorogenic acids (max. 249.88, 450.35, 192.16 mg/100 g DW). The main metabolites inA. arbutifoliashoot extracts were: chlorogenic, isochlorogenic and cryptochlorogenic acids (max. 361.60, 224.5, 526.2 mg/100 g DW). The largest total amounts of the compounds were confirmed in the cultures of both aronias after the addition of cinnamic acid (989.79 and 661.77 mg/100 g DW, respectively) and caffeic acid (854.99 and 1098.46 mg/100 g DW, respectively) at concentrations of 5 mmol/l on 10th day of growth cycles. These maximum amounts were 3.41, 3.42, 2.95 and 5.67 times higher, respectively, than in the control cultures. This is the first report documenting the high production of depsides in shoot cultures of black and red aronias after feeding with their biosynthetic precursors. Key message The influence of feeding culture media with biogenetic precursors on high production of depsides in agitated shoot cultures ofAronia melanocarpaandAronia arbutifoliawas proved.

关键词： Videos   Data collection   Education   Mashups   Computer science   Flipped classroom   software engineering   comparative study  

摘要： This paper reports our experience in flipping a second- year undergraduate course on software architecture and integration, taught in the second course of a Software Engineering degree. We compare the application of the flipped-classroom methodology with a traditional methodology. Our study encompasses two academic courses, in the years 2017 and 2018, and involves a total number of 434 students and 6 lecturers, placing this among the largest studies on flipped-classroom to date. The paper also reports on the production of the videos used with the flipped-classroom methodology, recorded by the lecturers in informal settings, and provides several lessons learned in this regard. The results of the study, backed by a solid statistical analysis of the data, demonstrate the suitability of the flipped-classroom methodology for laboratory sessions in the subject course. Among other results, our analysis concluded that students had on average 24 more minutes per session to solve in-class exercises with the flipped-classroom methodology;more than 70% of the students considered that the quantity, duration and didactic content of the videos were (very) appropriate;and 9 out of every 10 students would prefer this methodology in the laboratory sessions of future courses rather than a traditional face-to-face approach.

关键词： Computer science   Medical imaging   Knee osteoarthritis   X-ray   Femoral-tibial angle   Active shape model  

摘要： Femoral-tibial alignment is a prominent risk factor for Knee Osteoarthritis (KOA) incidence and progression. One way of assessing alignment is by determining the Femoral-Tibial Angle (FTA). Several studies have investigated FTA determination;however, methods of assessment of FTA still present challenges. This paper introduces a new method for semi-automatic measurement of FTA as part of KOA research. Our novel approach combines preprocessing of X-ray images and the use of Active Shape Model (ASM) as the femoral and tibial segmentation method, followed by a thinning process. The result of the thinning process is used to predict FTA automatically by measuring the angle between the intersection of the two vectors of branching points on the femoral and tibial areas. The proposed method is trained on 10 x-ray images and tested on 50 different x-ray images of the Osteoarthritis Initiative (OAI) dataset. The outcomes of this approach were compared with manually obtained FTA measurements from the OAI dataset as the ground truth. Based on experiments, the difference in measurement results between the FTA of the OAI and the FTA obtained using our method is quite small, i.e., below 0.81 degrees for the right FTA and below 0.77 degrees for the left FTA with minimal average errors. This result indicates that this method is clinically suitable for semi-automatic measurement of the FTA.

关键词： Random access memory   Computer science   Consumer electronics   Performance evaluation   Tablet computers   Smart phones   Solid-state drives   address translation   hit ratio   performance   group-level mapping  

摘要： NAND flash memory has been widely used as data storage devices in consumer electronics, such as tablet computers and smart phones. Logical-to-physical address translation is important for improving the performance of NAND flash-based SSDs. Even though keeping the mapping table in a DRAM can boost the address translation, it is already infeasible to do this as the capacity of SSDs keeps increasing and only a limited part of DRAM will be used as the mapping cache. Orthogonal to the demand-based page-level FTLs, we develop a novel group-level mapping which divides the whole SSD into multiple equal-size groups. To map a logical-page-number to a physical-page-number, it will be translated into a group number and an offset. The group number can be obtained via calculation, and the offset will be retrieved from a recorded mapping entry which can correspond to any position within a group. Group-level mapping reduces the size of mapping table while obtaining the similar flexibility as the page-level mapping. We also design an effective group-level FTL (GFTL) with a block pool management approach. Our simulations show that GFTL improves the hit ratio of mapping cache and thus reduces the average response time.

关键词： crime   justice   emotion   abolition   capital punishment   police   New Brunswick  

摘要： On 13 December 1974, Moncton policemen Corporal Aurele Bourgeois and Constable Michael O'Leary were kidnapped and murdered, evoking an intense public response of grief and anger against the perpetrators. The funeral for the murdered men and the trial and conviction of Richard Ambrose and James Hutchison for the crime offers an example of how emotions evoked by sensational murders played an important role in the Canadian criminal justice system and debates on capital punishment. Examining the reactions of the police, political figures, and the media, as well as how sympathy was managed at the trial, demonstrates how certain laws aimed to regulate the emotions related to violent crime: accepting expressions of compassion and sadness, but not anger and vengeance. The murders also coincided with a majority federal Liberal government committed to changing the laws surrounding capital punishment. Even though the perpetrators elicited little public sympathy, their case was used as both an opportunity to champion hope and forgiveness in the cause of abolition and an example for retentionist calls for retribution and punishment. This article examines how the grief and anger of one community illustrated the criminal laws designed to regulate emotions in court and outside of it and intersected with the contemporary debates on abolition, highlighting the importance of the grief and anger of policemen and police associations in capital cases and in the debates over the death penalty.

关键词： Computer science   Applied computing in medical science   Tuberculosis   Deep learning   Chest X-Ray  

摘要： Background: Machine learning has been an emerging tool for various aspects of infectious diseases including tuberculosis surveillance and detection. However, the World Health Organization (WHO) provided no recommendations on using computer-aided tuberculosis detection software because of a small number of studies, methodological limitations, and limited generalizability of the findings. Methods: To quantify the generalizability of the machine-learning model, we developed a Deep Convolutional Neural Network (DCNN) model using a Tuberculosis (TB)-specific chest x-ray (CXR) dataset of one population (National Library of Medicine Shenzhen No.3 Hospital) and tested it with non-TB-specific CXR dataset of another population (National Institute of Health Clinical Centers). Results: In the training and intramural test sets using the Shenzhen hospital database, the DCCN model exhibited an AUC of 0.9845 and 0.8502 for detecting TB, respectively. However, the AUC of the supervised DCNN model in the ChestX-ray8 dataset was dramatically dropped to 0.7054. Using the cut points at 0.90, which suggested 72% sensitivity and 82% specificity in the Shenzhen dataset, the final DCNN model estimated that 36.51% of abnormal radiographs in the ChestX-ray8 dataset were related to TB. Conclusion: A supervised deep learning model developed by using the training dataset from one population may not have the same diagnostic performance in another population. Conclusion: Technical specification of CXR images, disease severity distribution, dataset distribution shift, and overdiagnosis should be examined before implementation in other settings.

关键词： Optimization   Clustering algorithms   Particle swarm optimization   Computer science   Sociology   Statistics   Trajectory   Competitive swarm optimizer (CSO)   evolutionary multiobjective optimization   large-scale multiobjective optimization problem   particle swarm optimization (PSO)  

摘要： There exist many multiobjective optimization problems (MOPs) containing a large number of decision variables in real-world applications, which are known as large-scale MOPs. Due to the ineffectiveness of existing operators in finding optimal solutions in a huge decision space, some decision variable division-based algorithms have been tailored for improving the search efficiency in solving large-scale MOPs. However, these algorithms will encounter difficulties when solving problems with complicated landscapes, as the decision variable division is likely to be inaccurate and time consuming. In this paper, we propose a competitive swarm optimizer (CSO)-based efficient search for solving large-scale MOPs. The proposed algorithm adopts a new particle updating strategy that suggests a two-stage strategy to update position, which can highly improve the search efficiency. The experimental results on large-scale benchmark MOPs and an application example demonstrate the superiority of the proposed algorithm over several state-of-the-art multiobjective evolutionary algorithms, including problem transformation-based algorithm, decision variable clustering-based algorithm, particle swarm optimization algorithm, and estimation of distribution algorithm.

关键词： Computer Science   Public Domain Software   Software Engineering   Open Source Research Software   Computer Science   Open Source Software Licenses   Reusable Research Software   Sustainable Research Software   Software Engineering   Computational Science   Software Publishing   Open Source Software   Scientific Computing   Software Engineering   Artificial Intelligence   Licenses  

摘要： For good scientific practice, research software should be open source. It should be both archived for reproducibility and actively maintained for reusability.