教学课程资源库 更多>>

关键词： Social network services   User-generated content   Predictive models   Cybernetics   Measurement   Computer science   Australia   Dual implicit mining   latent friend recommendation   random walk with restart   user interest topic  

摘要： The latent friend recommendation in online social media is interesting, yet challenging, because the user-item ratings and the user-user relationships are both sparse. In this paper, we propose a new dual implicit mining-based latent friend recommendation model that simultaneously considers the implicit interest topics of users and the implicit link relationships between the users in the local topic cliques. Specifically, we first propose an algorithm called all reviews from a user and all tags from their corresponding items to learn the implicit interest topics of the users and their corresponding topic weights, then compute the user interest topic similarity using a symmetric Jensen-Shannon divergence. After that, we adopt the proposed weighted local random walk with restart algorithm to analyze the implicit link relationships between the users in the local topic cliques and calculate the weighted link relationship similarity between the users. Combining the user interest topic similarity with the weighted link relationship similarity in a unified way, we get the final latent friend recommendation list. The experiments on real-world datasets demonstrate that the proposed method outperforms the state-of-the-art latent friend recommendation methods under four different types of evaluation metrics.

关键词： Diseases   Heterogeneous networks   Neoplasms   Semantics   Computer science   Reliability   Ontologies   Disease-associated miRNA prediction   heterogeneous networks   node attributes   non-negative matrix factorization  

摘要： Identification of disease-associated microRNAs (disease miRNAs) is an essential step towards discovering causal miRNAs and understanding disease pathogenesis. Two sources of information can be exploited for predicting disease miRNAs: one includes the connections between miRNAs, between diseases, and between miRNAs and diseases, and the other has the attributes of miRNA nodes. The former contains information of miRNA similarities, disease similarities, and miRNA-disease associations. The latter includes the information of the families and clusters that miRNAs belong to. Similar diseases are usually associated with miRNAs that have similar functions and common attributes. However, most of the existing methods for disease miRNA prediction focus only on the connections of miRNAs and diseases. It remains challenging to adequately integrate the connections and miRNA node attributes to identify more reliable candidate disease miRNAs. We propose a non-negative matrix factorization based method, FamCluRank, for predicting disease miRNAs in heterogeneous networks with node attributes. One of the novelties of FamCluRank is to fully utilize these two oversighted characteristics of miRNAs and focuses particularly on a deep integration of miRNA families and cluster attributes. In particular, the integration was achieved by three different means. We first constructed a miRNA-disease heterogeneous network with node attributes where the miRNA nodes have their family and cluster attributes. Second, miRNAs sharing more common families and clusters are more likely to be associated with the diseases that are also related to these families and clusters. On the basis of the biological premise, we constructed a novel prediction model of FamCluRank to deeply integrate the family and cluster attributes of miRNAs. Third, two similar diseases tend to be associated with more common miRNA families and clusters, and vice versa. Hence, FamCluRank's prediction model is constructed by concerning not

关键词： Capstone project   assessment   computer science  

摘要： A capstone project is an extensive learning experience traditionally developed during a student's final academic year. Assessing such a complex assignment involves several challenges and is usually based upon the evaluations of at least two different people: the capstone project advisor, and one or more other assessors. Quantitative studies comparing only different assessors' grades and qualitative studies investigating the origin of possible discrepancies have been conducted. In both cases, contradictory conclusions were reached. The objective of this study is to analyze the factors that are given consideration by assessors of engineering capstone projects and the influence of these factors on the discrepancies between different assessors' opinions of the same project. This study quantitatively examined 162 computer science engineering capstone projects developed by one student and supervised by one advisor. Each project was assessed by the project advisor and a committee. For each project, the advisor and the committee were asked to complete an additional questionnaire on product characteristics, student competences, and project supervision. Competences demonstrated by the student were found to be the most relevant element when a capstone project was evaluated by the advisor and the committee;product characteristics were found to be second in influence. Furthermore, advisors grant minor significance to the advisor-involvement component. Discrepancies between grades seem to be associated with those aspects to which one assessor has access, while the other does not, such as student skills demonstrated during project development or their performance in the oral defense. Both the advisor's and the committee's perspectives are important in the assessment of this complex task and they complement one another.

关键词： Computer science education   gamification   group size   higher education studies   longitudinal effect  

摘要： Gamification is the use of game elements in domains other than games. Gamification use is often suggested for difficult activities because it enhances users' engagement and motivation level. Due to such benefits, the use of gamification is also proposed in education environments to improve students' performance, engagement, and satisfaction. Computer science in higher education is a tough area of study and thus needs to utilize various already explored benefits of gamification. This research develops an empirical study to evaluate the effectiveness of gamification in teaching computer science in higher education. Along with the learning outcomes, the effect of group size on students' satisfaction level is also measured. Furthermore, the impact of gamification over time is analyzed throughout a semester to observe its effectiveness as a long-term learning technique. The analysis, covering both learning outcome and students' satisfaction, suggests that gamification is an effective tool to teach tough courses at higher education level;however, group size should be taken into account for optimal classroom size and better learning experience.

摘要： Exploring goals, perspectives, and challenges.

关键词： Electrical engineering   Computer science   Electromagnetics   Environmental risk assessment   High performance computing   Network (computer science)   Quality of life   Radiation physics   Radiology   Signal processing   Wave physics   Power constraints   EMF   Exposure limits   EMF spectral density  

摘要： Environmental exposure to man-made electromagnetic field (EMF) has been rising as modern technologies have grown and changes in social behavior have generated more synthetic sources. For safety of human health, EMF levels need to be regulated. The level of EMF should be well below levels where there might be harm, hence we do not expect to see any health effects at these levels. Current regulations fail to place a strict limit on EMF in situations where multiple nearby devices transmit simultaneously. The way these regulations are expressed needs great care because it will have an effect on the design of wireless communication systems. In this paper, it is argued that transmitted power constraints on wireless communication devices should be expressed in a different way, namely that devices should limit the EMF spectral density that they generate to the difference between the maximum allowed, by the standard, and the amount currently present, as measured by the device, in the spectral region where it is active. Note that the limit on EMF should be expressed in terms of its EMF spectral density rather than as a total EMF over each of a series of separate bands. If all devices limit their own EMF spectral density, in the spectral region where they are active, in such a way that total EMF spectral density is below the regulated limit in that region, then it is certain that the aggregate EMF spectral density will be below the regulated limit at all frequencies.

关键词： Optimization   Particle swarm optimization   Density measurement   Computer science   Atmospheric measurements   Particle measurements   Leader selection   many-objective evolutionary algorithms (MaOEAs)   many-objective optimization   particle swarm optimizer (PSO)  

摘要： The particle swarm optimizer (PSO), originally proposed for single-objective optimization problems, has been widely extended to other areas. One of them is multiobjective optimization. Recently, using the PSO to handle many-objective optimization problems (MaOPs) (i.e., problems with more than three objectives) has caught increasing attention from the evolutionary multiobjective community. In the design of a multiobjective/many-objective PSO algorithm, the selection of leaders is a crucial issue. This paper proposes an effective many-objective PSO where the above issue is properly addressed. For each particle, the leader is selected from a certain number of historical solutions by using scalar projections. In the objective space, historical solutions record potential search directions, and the leader is elected as the solution that is closest to the Pareto front in the direction determined by the nadir point and the point constructed by the objective vector of this particle. The proposed algorithm is compared with eight state-of-the-art many-objective optimizers on 37 test problems in terms of four performance metrics. The experimental results have shown the superiority and competitiveness of our proposed algorithm. The new algorithm is free of a set of weight vectors and can handle Pareto fronts with irregular shapes. Given the high performance and good properties of the proposed algorithm, it can be used as a promising tool when dealing with MaOPs.

关键词： Introductory programming   computational thinking   programming   K-12 education   instructional practices   curricula  

摘要： The number of computer science (CS) courses has been dramatically expanding in U.S. high schools (HS). In comparisonwithwell-established courses in mathematics and science, little is known about howthe decisions made by HS CS teachers regarding how and what to teach impact student performance later in introductory college CS courses. Drawing on a large sample of 2,871 introductory college CS students at 115 U.S. institutions who had taken a CS course in HS, we examined the topic coverage and prevailing instructional methods in the HS course and investigated how these experiences influenced student performance in college CS. Controlling for differences in student background, we find two predictors of higher grades in college CS: greater frequency of coding-related activities in HS (programming, debugging, studying algorithms) and lower frequency of "non-coding" computer use (e.g., data analysis, computer security). Interaction models revealed a more complex story. Coding-related activity more heavily benefited students who did not have coding help available at home. In the 28% of college CS courses in which instructors employed innovative pedagogies, students with higher ACT or SAT mathematics scores had a greater advantage than in traditionally taught courses. Finally, in the innovative college courses, students whose HS CS exams had typically included testing on vocabulary did worse than students whose exams had not included such tests.

关键词： Computer science   Molecular medicine   Prostate cancer  

摘要： Background Unsupervised learning methods, such as Hierarchical Cluster Analysis, are commonly used for the analysis of genomic platform data. Unfortunately, such approaches ignore the well-documented heterogeneous composition of prostate cancer samples. Our aim is to use more sophisticated analytical approaches to deconvolute the structure of prostate cancer transcriptome data, providing novel clinically actionable information for this disease. Methods We apply an unsupervised model called Latent Process Decomposition (LPD), which can handle heterogeneity within individual cancer samples, to genome-wide expression data from eight prostate cancer clinical series, including 1,785 malignant samples with the clinical endpoints of PSA failure and metastasis. Results We show that PSA failure is correlated with the level of an expression signature called DESNT (HR = 1.52, 95% CI = [1.36, 1.7], P = 9.0 x 10(-14), Cox model), and that patients with a majority DESNT signature have an increased metastatic risk (X-2 test, P = 0.0017, and P = 0.0019). In addition, we develop a stratification framework that incorporates DESNT and identifies three novel molecular subtypes of prostate cancer. Conclusions These results highlight the importance of using more complex approaches for the analysis of genomic data, may assist drug targeting, and have allowed the construction of a nomogram combining DESNT with other clinical factors for use in clinical management.

关键词： Race   ethnicity   gender   intersectionality  

摘要： Computer science (CS) has been identified as one of the fastest-growing professions, with demand for CS professionals far outpacing the supply of CS graduates. The necessity for a trained CS workforce has compelled industry and academia to evaluate strategies for broadening participation in CS. The current literature in CS education emphasizes the importance of social relationships and supports for individuals from under-represented groups. Unfortunately, this literature has largely been limited to either the exploration of issues of women or that of underrepresented racial/ethnic groups. These limited views generalize characteristics of specific underrepresented groups without considering intersections between these groups. This quantitative study (n = 3,206) addressed that shortcoming by leveraging inferential statistical methods to examine (i) the similarities and differences between the social CS-related experiences of Black women, Black men, and non-Black women in the United States;(ii) the relationship between these experiences and CS career choices;and (iii) the activities during which significant social experiences might occur. The results indicate that Black women's social experiences are often different from the experiences of both Black men and non-Black women. In particular, both Black men and non-Black women had more CS friends than Black women, whereas having these friends was more significant for the CS career choice for Black women. Introductions to CS in school, before college, were negatively related to career choice for all groups, whereas home support was positive for both Black women and men. This work suggests that considering intersectionality is important to understanding the needs of different individuals, as well as the importance of social supports for persistence in CS.