MGAT: A generative graph model with expressive attention to motifs

Traditional algorithms for generating graphs are efficient, occasionally implementing heuristics to emulate specific characteristics of real-world networks. However, these algorithms fail to replicate all the complexities contained within real-world networks. In recent years, graph generative models that implement graph neural networks have shown the capability to generate output graphs which generalize to the input graphs that they were trained on. Yet, these graph generative models suffer from limitations with respect to expressiveness and scalability that stem from the graph neural networks integrated in their structure.This thesis conducted an exploratory data analysis and survey to investigate standard assumptions made in state-of-the-art frameworks regarding training data and algorithms. A comparative study was conducted on Motif-Attentive Graph Network (MGAT), a novel graph generative model, with a focus on the model's applications for capturing motifs and other graph structural properties within its training data.All three experiments demonstrated results that align with current research. The exploratory data analysis results support that to preserve graph structures, a sampling method requires around 30 percent of the original graph's nodes, any lower percentages cause a significant loss of structural information. The survey results show expressive graph generative models are not necessarily the best at generalizing to training data but can preserve motifs. The comparative study demonstrated that expressive graph generative models are more effective at preserving higher-order motifs and performance did not differ between the two preprocessing methods

Review on Superconducting Materials

Short review of the topical comprehension of the superconductor materials classes Cuprate High-Temperature Superconductors, other oxide superconductors, Iron-based Superconductors, Heavy-Fermion Superconductors, Nitride Superconductors, Organic and other Carbon-based Superconductors and Boride and Borocarbide Superconductors, featuring their present theoretical understanding and their aspects with respect to technical applications.Comment: A previous version of this article has been published in \" Applied Superconductivity: Handbook on Devices and Applications \", Wiley-VCH ISBN: 978-3-527-41209-9. The new extended and updated version will be published in \" Encyclopedia of Applied Physics \", Wiley-VC

Polymorphism and Mechanical Behavior in Hot-Pressed 3D-Printed Polyamide Composite: Effects of Pressure and Temperature

The aim of this work is to study the effect of high-temperature compaction (HTC) upon the polymorphism and the mechanical behavior of an additively manufactured (AM) carbon fiber-reinforced polyamide (PA6). Different pressure and temperature levels during HTC were tested to determine the overall effect on the mechanical behavior and material crystalline composition. Treated, carbon fiber-reinforced PA6 samples were analyzed using differential scanning calorimetry, X-ray diffraction, thermogravimetric analysis, scanning electron microscopy, and three-point bending testing. When considered with respect to as-printed samples, an HTC temperature of 190 °C combined with 80 psi pressure resulted in an increased flexural modulus and strength of 47% and 58%, respectively. This increase was attributed to the decrease in AM-induced cracking, voids (both inside and between the beads), and crystalline solid-state transition in the PA6. The effect of pressure and temperature on the crystalline structure was discussed in terms of an increased degree of crystallinity and the amount of α-phase. Therefore, HTC can help overcome some limitations of traditional annealing, which can result in recrystallization-induced cracking which can lead to material embrittlement. The proposed HTC method demonstrates the potential in improving the mechanical behavior of AM thermoplastic composites

On the two-dimensional Brillouin flow

The Brillouin flow is a rectilinear, sheared electron fluid flow in a crossed electric field (E) and magnetic field (B), in the E x B direction with zero flow velocity and zero electric field at the surface with which the flow is in contact. It is broadly considered as the equilibrium electron flow in high power crossed-field devices including the magnetron and magnetically insulated transmission line oscillators. This paper provides an examination of Brillouin flow in two dimensions, in a cylindrical geometry where the anode radius changes abruptly at a single axial location while the cathode surface has a constant radius. Our simulation confirms the proof that there is no equilibrium Brillouin flow solution for such a geometry. It further reveals that this change in the anode radius introduces novel bunching of the electrons within the Brillouin hub. This bunching occurs at low frequencies and is very pronounced if the Brillouin flow is from the small gap region to the large gap region, but is minimal if the Brillouin flow is from the large gap region to the small gap region. New insights are provided into the physical processes that initiate and sustain the bunching processes that are unique for a crossed-field diode, as compared with a non-magnetized diode. We argue that this enhanced bunching, and its concomitant formation of strong vortices, is not restricted to an abrupt change in the anode-cathode gap spacing

Post-Processing and Characterization of Additive Manufactured Carbon Fiber Reinforced Semi-Crystalline Polymers

The aim of this work is to study the effect of post-processing on additive manufactured (AM) continuous carbon fiber reinforced plastics (CFRPs) performance. As-printed AM CFRPs do not perform as well as conventionally manufactured CFRPs with the same composition. Possible improvements to AM CFRP performance include annealing and applying uniaxial pressure with elevated temperature. Samples were subjected to pressure and temperature treatments and annealing at a constant temperature. Treated materials were subjected to three-point bending tests, differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), and scanning electron microscopy (SEM) to characterize and assess sample performance. Results were assessed for flexural strength, flexural modulus, void content, fiber content, and layer thickness. Increased temperature combined with pressure in post-processing resulted in higher flexural modulus, higher maximum flexural stress, and decreased void content. Void content decreased with increasing temperature and pressure

Agricultural UAVs - A Case Study on Their Implementation in the US Market

The use of UAVs in agriculture represents a new market ready for explosive domestic growth, and could even be a game changer. Like the PC industry, many military funded technologies have been combined in products that are now just sold as a niche novelty for hobbyists. The agricultural UAV industry is near the point where the market can shift from this hobbyist, smallscale into an agricultural necessity, much like the PC industry shifted when IBM and its PC came onto the scene. Many small companies (and divisions of larger ones) are working on the use of drones in agriculture, but face unique regulatory challenges. This paper explores this budding agricultural UAV market, compares existing agricultural solutions, examines the technologies behind this new market, the regulations constraining this technology, and includes an evaluation of the field’s economic and technological likely future

Relationship between the family APGAR and behavioral problems in children

Objectives: to assess the use of the Family APGAR instrument as a supplement to usual clinical methods for the detection of psychosocial problems in children and to evaluate the relationship between the Family APGAR and physician diagnosis and elevated Child Behavior Checklist (CBCL) scores.Design: cross-sectional.Setting: ambulatory care center of a community-based, university-affiliated family medicine training program.Subject: one hundred fifty-two parents of children aged 3 to 16 years.Main outcome measures: family functioning was considered poor if Family APGAR scores were 5 or less. For the CBCL, sum total T scores greater than the 90th percentile for nonreferred children were considered clinically significant. Physicians used a checklist to indicate the presence of psychosocial problems or family dysfunction.Results: agreement between the Family APGAR scores and the physician's detection of child psychosocial problems was weak (kappa = 0.23). There was no relationship between the Family APGAR scores and physician perception of family dysfunction (kappa = -0.05). Although agreement between the Family APGAR and CBCL classifications was weak (kappa = 0.20), families with low Family APGAR scores were more than twice as likely to have children with clinically significant CBCL scores than those with higher scores (risk ratio = 2.08; 95% confidence interval = 1.02 to 4.24).Conclusions: the relationships among the Family APGAR and CBCL scores and physician detection of child psychosocial problems were weak. Child psychosocial problems were more than twice as likely to be present when the Family APGAR score was low. These findings suggest that family functioning is related to child psychosocial problems, but that the Family APGAR may not improve screening for child psychosocial problem