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2022 ◽  
Vol 6 (POPL) ◽  
pp. 1-26
Kuen-Bang Hou (Favonia) ◽  
Zhuyang Wang

Randomized property-based testing has gained much attention recently, but most frameworks stop short at polymorphic properties. Although Bernardy  et al. have developed a theory to reduce a wide range of polymorphic properties to monomorphic ones, it relies upon ad-hoc embedding-projection pairs to massage the types into a particular form. This paper skips the embedding-projection pairs and presents a mechanical monomorphization for a general class of polymorphic functions, a step towards automatic testing for polymorphic properties. The calculation of suitable types for monomorphization turns out to be logarithm .

Michael D. Collins ◽  
Elvis Han Cui ◽  
Seung Won Hyun ◽  
Weng Kee Wong

AbstractThe key aim of this paper is to suggest a more quantitative approach to designing a dose–response experiment, and more specifically, a concentration–response experiment. The work proposes a departure from the traditional experimental design to determine a dose–response relationship in a developmental toxicology study. It is proposed that a model-based approach to determine a dose–response relationship can provide the most accurate statistical inference for the underlying parameters of interest, which may be estimating one or more model parameters or pre-specified functions of the model parameters, such as lethal dose, at maximal efficiency. When the design criterion or criteria can be determined at the onset, there are demonstrated efficiency gains using a more carefully selected model-based optimal design as opposed to an ad-hoc empirical design. As an illustration, a model-based approach was theoretically used to construct efficient designs for inference in a developmental toxicity study of sea urchin embryos exposed to trimethoprim. This study compares and contrasts the results obtained using model-based optimal designs versus an ad-hoc empirical design.

Cohen R. Simpson ◽  
David S. Kirk

Abstract Objectives Understanding if police malfeasance might be “contagious” is vital to identifying efficacious paths to police reform. Accordingly, we investigate whether an officer’s propensity to engage in misconduct is associated with her direct, routine interaction with colleagues who have themselves engaged in misbehavior in the past. Methods Recognizing the importance of analyzing the actual social networks spanning a police force, we use data on collaborative responses to 1,165,136 “911” calls for service by 3475 Dallas Police Department (DPD) officers across 2013 and 2014 to construct daily networks of front-line interaction. And we relate these cooperative networks to reported and formally sanctioned misconduct on the part of the DPD officers during the same time period using repeated-events survival models. Results Estimates indicate that the risk of a DPD officer engaging in misconduct is not associated with the disciplined misbehavior of her ad hoc, on-the-scene partners. Rather, a greater risk of misconduct is associated with past misbehavior, officer-specific proneness, the neighborhood context of patrol, and, in some cases, officer race, while departmental tenure is a mitigating factor. Conclusions Our observational findings—based on data from one large police department in the United States—ultimately suggest that actor-based and ecological explanations of police deviance should not be summarily dismissed in favor of accounts emphasizing negative socialization, where our study design also raises the possibility that results are partly driven by unobserved trait-based variation in the situations that officers find themselves in. All in all, interventions focused on individual officers, including the termination of deviant police, may be fruitful for curtailing police misconduct—where early interventions focused on new offenders may be key to avoiding the escalation of deviance.

2022 ◽  
Vol 9 (1) ◽  
Grégoire Thürig ◽  
Raùl Panadero-Morales ◽  
Luca Giovannelli ◽  
Franziska Kocher ◽  
José Luis Peris ◽  

Abstract Purpose This study's main objective is to assess the feasibility of processing the MRI information with identified ACL-footprints into 2D-images similar to a conventional anteroposterior and lateral X-Ray image of the knee. The secondary aim is to conduct specific measurements to assess the reliability and reproducibility. This study is a proof of concept of this technique. Methods Five anonymised MRIs of a right knee were analysed. A orthopaedic knee surgeon performed the footprints identification. An ad-hoc software allowed a volumetric 3D image projection on a 2D anteroposterior and lateral view. The previously defined anatomical femoral and tibial footprints were precisely identified on these views. Several parameters were measured (e.g. coronal and sagittal ratio of tibial footprint, sagittal ratio of femoral footprint, femoral intercondylar notch roof angle, proximal tibial slope and others). The intraclass correlation coefficient (ICCs), including 95% confidence intervals (CIs), has been calculated to assess intraobserver reproducibility and interobserver reliability. Results Five MRI scans of a right knee have been assessed (three females, two males, mean age of 30.8 years old). Five 2D-"CLASS" have been created. The measured parameters showed a "substantial" to "almost perfect" reproducibility and an "almost perfect" reliability. Conclusion This study confirmed the possibility of generating "CLASS" with the localised centroid of the femoral and tibial ACL footprints from a 3D volumetric model. "CLASS" also showed that these footprints were easily identified on standard anteroposterior and lateral X-Ray views of the same patient, thus allowing an individual identification of the anatomical femoral and tibial ACL's footprints. Level of evidence Level IV diagnostic study

Sensors ◽  
2022 ◽  
Vol 22 (2) ◽  
pp. 571
Eric Chiejina ◽  
Hannan Xiao ◽  
Bruce Christianson ◽  
Alexios Mylonas ◽  
Chidinma Chiejina

The distributed nature of mobile ad hoc networks (MANETs) presents security challenges and vulnerabilities which sometimes lead to several forms of attacks. To improve the security in MANETs, reputation and trust management systems (RTMS) have been developed to mitigate some attacks and threats arising from abnormal behaviours of nodes in networks. Generally, most reputation and trust systems in MANETs focus mainly on penalising uncooperative network nodes. It is a known fact that nodes in MANETs have limited energy resources and as such, the continuous collaboration of cooperative nodes will lead to energy exhaustion. This paper develops and evaluates a robust Dirichlet reputation and trust management system which measures and models the reputation and trust of nodes in the network, and it incorporates candour into the mode of operations of the RTMS without undermining network security. The proposed RTMS employs Dirichlet probability distribution in modelling the individual reputation of nodes and the trust of each node is computed based on the node’s actual network performance and the accuracy of the second-hand reputations it gives about other nodes. The paper also presents a novel candour two-dimensional trustworthiness evaluation technique that categorises the behaviours of nodes based on their evaluated total reputation and trust values. The evaluation and analyses of some of the simulated behaviours of nodes in the deployed MANETs show that the candour two-dimensional trustworthiness evaluation technique is an effective technique that encourages and caters to nodes that continuously contribute to the network despite the reduction in their energy levels.

2022 ◽  
Daniel Gardner

Evolution conserves components below, and goals above, the levels for circuits and computations. This work presents evidence consistent with similar evolutionary conservation of a small, possibly canonical number of circuits and computations, and cites some historical interest in this idea. Electronic circuits are examples of what we would like to know. There are several strikingly common features of nervous systems that may be both conserved and computational essential. There is always a null hypothesis, and the work acknowledges the possibility that computation itself is ad-hoc in multiple areas and nervous systems, and not itself a conserved property. But we don’t know, and we should.

2022 ◽  
Tim Gould ◽  
Zahed Hashimi ◽  
Leeor Kronik ◽  
Stephen Dale

In calculations based on density functional theory, the "HOMO-LUMO gap" (difference between the highest occupied and lowest unoccupied molecular orbital energies) is often used as a low-cost, ad hoc approximation for the lowest excitation energy. Here we show that a simple correction based on rigorous ensemble density functional theory makes the HOMO-LUMO gap exact, in principle, and significantly more accurate, in practice. The introduced perturbative ensemble density functional theory approach predicts different and useful values for singlet-singlet and singlet-triplet excitations, using semi-local and hybrid approximations. Excitation energies are of similar quality to time-dependent density functional theory, especially at high fractions of exact exchange. It therefore offers an easy-to-implement and low-cost route to robust prediction of molecular excitation energies.

Hsuan-Ying Liu

Abstract Although Computer-Assisted Language Learning (CALL) is relied upon heavily in these disruptive times due to the COVID-19 pandemic, little is known about committed learners’ reactions to CALL as they actively voiced their questions and concerns during crisis-prompted remote learning. Employing a qualitative research method, findings reveal that their attitudes toward remote learning were ambivalent. While they viewed online tools as useful learning resources, they also expressed hesitation in adopting them. Meanwhile, they welcomed innovative ad hoc curriculum quickly developed by the instructor; however, the innovative curriculum was also viewed as less organized. These findings shed light on pedagogical implications for world language education in higher education and urge researchers to further investigate how remote language teaching and learning would affect committed students during the new normal times as foreign language enrollments continue to decline.

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