On the Integrity of Online Testing for Introductory Statistics Courses: A Latent Variable Approach

There has been a remarkable growth in distance learning courses in higher education. Despite indications that distance learning courses are more vulnerable to cheating behavior than traditional courses, there has been little research studying whether online exams facilitate a relatively greater level of cheating. This article examines this issue by developing an approach using a latent variable to measure student cheating. This latent variable is linked to both known student mastery related variables and variables unrelated to student mastery. Grade scores from a proctored final exam and an unproctored final exam are used to test for increased cheating behavior in the unproctored exam Accessed 4,410 times on https://pareonline.net from April 11, 2015 to December 31, 2019. For downloads from January 1, 2020 forward, please click on the PlumX Metrics link to the right

Why Learning Styles Matter For Student Achievement In College Economics

This paper explores the link between student achievement and student learning styles in a college microeconomics course, based on the Dunn and Dunn model of learning styles.  The Productivity Environmental Survey (PEPS) is utilized to measure learning style preferences for twenty elements.  Factor analysis is applied to reduce the multidimensional preferences to a smaller set of common factors that identify analytic, global or indifferent learning styles.  The common factors are used as explanatory variables to measure the correlation between student achievement and their learning styles.  The empirical methodology developed in this study also provides a test of the internal validity of the Dunn and Dunn model, the construct validity of the PEPS instrument and the predictive validity of the model.  The authors explain how the results of the current research could be utilized to more generally enhance student achievement in the instruction of introductory economics and potentially other subject matter

The influence of beauty influencers' expertise on Chinese consumers' intention to purchase beauty brands

Abstract As social media continues to advance, consumers increasingly rely on social media to access information about beauty products, which has led to a proliferation of beauty influencers. Beauty influencers have become an important source of information on beauty products for many consumers by posting information and tips about beauty products on social media platforms to showcase their expertise. The content shared by beauty influencers on social media platforms is also subliminally influencing consumers' attitudes, perceptions and behaviours. The impact of social media influencers as a marketing communication tool has been extensively studied. Different scholars often use expertise as an important feature of source credibility models to measure the credibility of celebrities and social media influencers. However, most scholarship on this expertise feature has been measured on a single dimension. However, the degree of expertise of influencers in specialist domains should be measured more comprehensively. Therefore, this study draws on research from other fields to categorise expertise into two dimensions, domain depth and domain breadth, for research. This dissertation chooses to examine the expertise of beauty influencers and explore their influence on consumers' intention to purchase beauty brands along two new dimensions, domain depth and domain breadth, respectively. In addition, this study will investigate whether influencer type has a moderating role in the relationship between beauty influencers' expertise (domain depth and domain breadth) and consumers' intention to purchase beauty brands. This study focuses on Chinese consumers who are aware of or have followed any influencers on Chinese social media platforms and uses a quantitative research methodology to collect a total of 184 online questionnaires to explore the impact of beauty influencers' expertise on Chinese consumers' intention to purchase beauty brands. In addition, the study used established scales from existing research to measure the dimensions of expertise and purchase intention and used SPSS software to process the questionnaire data to test the research model and hypotheses presented in this study. The results of this study show that the domain depth of beauty influencers has a significant effect on Chinese consumers' intention to purchase beauty brands; the domain breadth of beauty influencers does not have a significant effect on Chinese consumers' intention to purchase beauty brands; the type of influencer does not moderate the relationship between the domain depth of beauty influencers and Chinese consumers' intention to purchase beauty brands, but the type of influencer does not moderate the relationship between the domain breadth of beauty influencers and Chinese consumers' intention to purchase beauty brands. Still, the type of influencer does not moderate the relationship between the domain breadth of beauty influencers. However, influencer type has a moderating effect on the relationship between the domain breadth of beauty influencers and Chinese consumers' intention to purchase beauty brands. Marketers of beauty and fashion brands can use the results to select more appropriate social media influencers for their marketing campaigns. This dissertation also concludes with some suggestions for future research

Active vibration isolation using a six-axis orthogonal vibration isolation platform with piezoelectric actuators

Piezoelectric actuators (PEA) act an important role in active vibration control area due to the advantages of fast response, high output force, small size and light weight. A 6-axis orthogonal vibration isolation platform based on PEAs is designed, which satisfies the demands of heavy payload, small installation space and multi degree of freedom vibration isolation. The dynamic model of the six-axis orthogonal vibration isolation platform with PEAs is established using Newton-Euler method. With the layout of six PEAs around the axis of symmetry, the dynamic equations could be decoupled into two single-input-single-output (SISO) subsystems and two multi-input-multi-output (MIMO) subsystems. Based on the modal superposition method, the two MIMO subsystems are further decoupled. The control strategy for each SISO system is developed with LQR control method. To evaluate the effectiveness of the control method, the simulation and verification experiment are conducted. The simulation result and experimental data indicate that the decoupling control of the proposed six-axis orthogonal vibration isolation platform with piezoelectric actuators effectively reduces the vibration response of payload within the target frequency range of 20 Hz to 200 Hz

Ethyl (2R,3S)-2-benzoyl-3-(4-bromo­phen­yl)-4-nitro­butano­ate

The title compoud, C19H18BrNO5, was synthesized by an organocatalytic reaction. The aymmetric unit contains two independent mol­ecules, in each of which the carbon between the two carbonyl groups adopts an R configuration, while the adjacent C atom has an S configuration. The dihedral angle between the two benzene rings is different in the two mol­ecules [11.64 (3) and 58.96 (4)°]

Bias-Conflict Sample Synthesis and Adversarial Removal Debias Strategy for Temporal Sentence Grounding in Video

Temporal Sentence Grounding in Video (TSGV) is troubled by dataset bias issue, which is caused by the uneven temporal distribution of the target moments for samples with similar semantic components in input videos or query texts. Existing methods resort to utilizing prior knowledge about bias to artificially break this uneven distribution, which only removes a limited amount of significant language biases. In this work, we propose the bias-conflict sample synthesis and adversarial removal debias strategy (BSSARD), which dynamically generates bias-conflict samples by explicitly leveraging potentially spurious correlations between single-modality features and the temporal position of the target moments. Through adversarial training, its bias generators continuously introduce biases and generate bias-conflict samples to deceive its grounding model. Meanwhile, the grounding model continuously eliminates the introduced biases, which requires it to model multi-modality alignment information. BSSARD will cover most kinds of coupling relationships and disrupt language and visual biases simultaneously. Extensive experiments on Charades-CD and ActivityNet-CD demonstrate the promising debiasing capability of BSSARD. Source codes are available at https://github.com/qzhb/BSSARD.Comment: accepted by AAAI 202

Transcriptome-wide high-throughput deep m6A-seq reveals unique differential m6A methylation patterns between three organs in Arabidopsis thaliana

Proportion of two types of m6A distributing feature in mRNA. (DOC 30 kb

(S)-3-Acetyl-3-[(R)-1-(4-bromo­phen­yl)-2-nitro­eth­yl]oxolan-2-one

The title compound, C14H14BrNO5, has two chiral C atoms. The quaternary C atom in the oxolanone ring has an S configuration, while the adjacent tertiary C atom has an R configuration. The oxolanone ring adopts an envelope conformation, with the flap C atom lying 0.298 (3) Å from the mean plane of the remaining four atoms. In the crystal, mol­ecules are connected into chains along [010] via weak C—H⋯O hydrogen bonds

Hysteresis linearization control of a novel hybrid vibration isolator

The undesired hysteresis exists widely in smart-material actuators, which significantly reduces the accuracy and response speed of the actuators. In this paper, the static experiment of our previously developed hybrid vibration isolator (HVI) employing piezoelectric actuator is implemented to choose appropriate preload of the HVI. The preload-dependent hysteresis of the HVI is also proved in the static experiment. To achieve the hysteresis linearization control of the HVI, two linearization methods named the feedforward linearization and feedforward compensation and PI feedback hybrid linearization control are presented, respectively, which are based on the Bouc-Wen model and corresponding parameter identification model. To evaluate the effectiveness of the proposed linearization controllers for the HVI, the experiments are implemented. The experiment results demonstrate that both linearization controllers for the HVI can linearize the hysteresis characteristics and improve the HVI control accuracy. In addition, the feedforward compensation and PI feedback hybrid linear controller can achieve higher linearity than feedforward compensation controller