Local Interpretability of Random Forests for Multi-Target Regression

Multi-target regression is useful in a plethora of applications. Although random forest models perform well in these tasks, they are often difficult to interpret. Interpretability is crucial in machine learning, especially when it can directly impact human well-being. Although model-agnostic techniques exist for multi-target regression, specific techniques tailored to random forest models are not available. To address this issue, we propose a technique that provides rule-based interpretations for instances made by a random forest model for multi-target regression, influenced by a recent model-specific technique for random forest interpretability. The proposed technique was evaluated through extensive experiments and shown to offer competitive interpretations compared to state-of-the-art techniques.Comment: 8 pages, 1 figure, 2 tables, to be submitted to XAI conference 2023 as an extended abstrac

STE(A)M: Not only education but also a lifestyle

If science can define meanings and measure results, art can express them and give a step forward to refreshment and innovation. The artist-scientist archetype started from Archimedes going to Nikolai Tesla, in about the inventor, the seeker, the dreamer, and the thinker, both as new scientist and artist. A growing number of schools are incorporating teaching methods that are more aligned to STEAM education (Science, Technology, Engineering, Arts and Mathematics) since it has become, almost very clear and concrete, that art’s education makes learning more fun and keeps everyone involved even more engaged. As exploring new possibilities, to lead innovation in the classroom and promote leadership at all levels, encourage teachers and principals, make the school and the whole system a dynamic one. The core value is that the need for STEAM education is critical, especially because there will be related jobs ready to be filled as soon as possible. This job is about to show, when and how can a STEAM educational concept can be delivered in a system that seems to have been destroyed from its old mistakes and can give a real boost to a new oriented public school, in the best possible integrated educational system for preparing students for the university and beyond. Primary inquiry, dialogue, and critical thinking seem to lead the way for a better life in the school environment and real-life society

Experimental and Numerical Study on Single-Bolted Cold-Formed Angles under Tension and Compression

Angle sections are commonly designed to bear only axial force, usually neglecting the additional bending moments resulting from the eccentric connection and the shift of the effective centroid. The current work deals with the capacity of single-bolted equal angle sections made from cold-formed steel. The experimental investigation presented herein includes tension and compression tests that subsequently are compared with the corresponding code provisions. Numerical analyses are also presented based on a detailed finite element simulation. Finally, a reliability analysis is implemented in order to demonstrate the reliability of the design rules for cold-formed steel angle columns. Results indicate a small discrepancy on the strength prediction in general by EN 1993-1-3, as well as by the AISI for slender columns and a more conservative one by EN 1993-1-1. A comparison of the above results is clearly illustrated herein in graphical forms

A new method for interpreting Vickers indentation measurements

A new method for interpreting Vickers microindentation data is proposed, based on continuum mechanics and, more precisely, the Gradient Elasticity framework. The main feature is the elastic properties’ calculation from the initial (elastic) region of the load vs. depth indentation data, which makes the calculation independent of the maximum indentation depth. This approach deviates significantly from the semi-empirical method of Oliver and Pharr, which calculates the material properties (such as elastic modulus and hardness) from the elastic unloading region, with the calculated values of the elastic modulus and hardness being strongly dependent on the indentation depth and, therefore, giving rise to the so-called indentation size effect (ISE). The proposed framework considers the Vickers indentation as a compression test with a complex geometry, as the pyramidal indenter tip applies load to directions perpendicular to its four faces. An elastic displacement field is initially assumed following Boussinesq\u27s solution before an indent is made, while afterwards the displacement of the material in contact with the tip is assumed to follow the Vickers tip\u27s geometry. The respective von Mises equivalent strain calculated through a continuum mechanics approach can qualitatively capture thin film delamination micrographs and shear band formation, showing the potential of the present formulation to model such micro-deformation problems. The traction vector calculated on each of the four sides of the Vickers tip, leads to the generation of load-displacement data, which compare well with experimental indentation data, with the elastic properties (i.e. elastic modulus) thus calculated being in accordance with the corresponding literature values

Surgical treatment of lumbar spinal stenosis with microdecompression and interspinous distraction device insertion. A case series

<p>Abstract</p> <p>Background</p> <p>Interspinous distraction devices (IPDD) are indicated as stand-alone devices for the treatment of spinal stenosis. The purpose of this study is to evaluate the results of patients undergoing surgery for spinal stenosis with a combination of unilateral microdecompression and interspinous distraction device insertion.</p> <p>Methods</p> <p>This is a prospective clinical and radiological study of minimum 2 years follow-up. Twenty-two patients (average age 64.5 years) with low-back pain and unilateral sciatica underwent decompressive surgery for lumbar spinal stenosis. Visual Analogue Scale, Oswestry Disability Index and walking capacity plus radiologic measurements of posterior disc height of the involved level and lumbar lordosis Cobb angle were documented both preoperatively and postoperatively. One-sided posterior subarticular and foraminal decompression was conducted followed by dynamic stabilization of the diseased level with an IPDD (X-STOP).</p> <p>Results</p> <p>The average follow-up time was 27.4 months. Visual Analogue Scale and Oswestry Disability Index improved statistically significantly (p < 0.001) in the last follow-up exam. Also, the walking distance increased in all patients but two. Posterior intervertebral disc height of the diseased level widened average 1.8 mm in the postoperative radiograph compared to the preoperative. No major complication, including implant failure or spinous process breakage, has been observed.</p> <p>Conclusions</p> <p>The described surgical technique using unilateral microdecompression and IPDD insertion is a clinically effective and radiologically viable treatment method for symptoms of spinal stenosis resistant to non-operative treatment.</p

Isolation and analysis of tetracycline-resistant Mycoplasma agalactiae strains from an infected goat herd in Cyprus — short communication

A major concern with the use of tetracycline against mycoplasmas is the development of resistance. Infections in small ruminants due to tetracyclineresistant Mycoplasma agalactiae strains are becoming a frequent problem worldwide. In the present paper the detection and analysis of three tetracycline-resistant M. agalactiae strains, isolated from infected goats in Cyprus, are reported. The three field isolates were identified as M. agalactiae by polymerase chain reaction (PCR) showing 98% identity to the M. agalactiae PG2 reference strain. Furthermore, they were found sensitive to tylosin, enrofloxacin, spiramycin and lincomycin. In contrast, they were resistant to tetracycline. None of the putative genes [tet(M), tet(O) and tet(S)] that commonly contribute to high-level resistance to tetracycline could be amplified from their genome. Contrarily, the field isolates were found to carry ISMag1, an insertion sequence related to the IS30 family of mobile elements. Although ISMag1 is widely believed to induce high-frequency chromosomal rearrangements resulting in phenotypic changes of microorganisms, its potential role in tetracycline resistance of mycoplasmas requires further studies