Can Programming be Liberated from the Two-Level Style? Multi-Level Programming with DeepJava

Since the introduction of object-oriented programming few programming languages have attempted to provide programmers with more than objects and classes, i.e., more than two levels. Those that did, almost exclusively aimed at describing language properties—i.e., their metaclasses exert linguistic control on language concepts and mechanisms— often in order to make the language extensible. In terms of supporting logical domain classification levels, however, they are still limited to two levels. In this paper we conservatively extend the object-oriented programming paradigm to feature an unbounded number of domain classification levels. We can therefore avoid the introduction of accidental complexity into programs caused by accommodating multiple domain levels within only two programming levels. We present a corresponding language design featuring “deep instantiation ” and demonstrate its features with a running example. Finally, we outline the implementation of our compiler prototype and discuss the potentials of further developing our language design

Matroids in OSCAR

OSCAR is an innovative new computer algebra system which combines and extends the power of its four cornerstone systems - GAP (group theory), Singular (algebra and algebraic geometry), Polymake (polyhedral geometry), and Antic (number theory). Here, we present parts of the module handeling matroids in OSCAR, which will appear as a chapter of the upcoming OSCAR book. A matroid is a fundamental and actively studied object in combinatorics. Matroids generalize linear dependency in vector spaces as well as many aspects of graph theory. Moreover, matroids form a cornerstone of tropical geometry and a deep link between algebraic geometry and combinatorics. Our focus lies in particular on computing the realization space and the Chow ring of a matroid.Comment: 13 pages, 1 figur

On the absolute thermodynamics of water from computer simulations: A comparison of first-principles molecular dynamics, reactive and empirical force fields

We present the absolute enthalpy, entropy, heat capacity, and free energy of liquid water at ambient conditions calculated by the two-phase thermodynamic method applied to ab initio, reactive and classical molecular dynamics simulations. We find that the absolute entropy and heat capacity of liquid water from ab initio molecular dynamics (AIMD) is underestimated, but falls within the range of the flexible empirical as well as the reactive force fields. The origin of the low absolute entropy of liquid water from AIMD simulations is due to an underestimation of the translational entropy by 20% and the rotational entropy by 40% compared to the TIP3P classical water model, consistent with previous studies that reports low diffusivity and increased ordering of liquid water from AIMD simulations. Classical MD simulations with rigid water models tend to be in better agreement with experiment (in particular TIP3P yielding the best agreement), although the TIP4P-ice water model, the only empirical force field that reproduces the experimental melting temperature, has the lowest entropy, perhaps expectedly. This reiterates the limitations of existing empirical water models in simultaneously capturing the thermodynamics of solid and liquid phases. We find that the quantum corrections to heat capacity of water can be as large as 60%. Although certain water models are computed to yield good absolute free energies of water compared to experiments, they are often due to the fortuitous enthalpy-entropy cancellation, but not necessarily due to the correct descriptions of enthalpy and entropy separately

Fostering Individual Learning Types On Online Learning Platforms To Strengthen Students\u27 Competencies

The availability of video lectures and hybrid formats in higher education has increased significantly due to the COVID-19 pandemic. Predominantly, however, instructional content has simply been translated 1-to-1 into video formats regardless of effectiveness and students\u27 needs. Interaction and diversity in content delivery were often missing. This practice paper presents an ongoing investigation on how lecture content can be presented within an online learning platform in order to meet the individual learning types of students and to address actual usage behaviour, potentially enabling a positive effect on learning outcomes. By creating learning paths, students can choose from different content modes, such as interactive video material, image hotspots and text material, and internalize the content according to their individual learning types. In addition, surveys are used to identify their motivation for choosing the content form as well as the extent to which this was helpful to successfully complete examination assignments. The results of the surveys will be analyzed and used for further improvements. Through the targeted use of different content modes, the positive aspects of online teaching can be furthered while strengthening the knowledge of the students individually in order to best prepare students for the complexity of a future work environment

a swarm intelligence-based optimizer for molecular geometry

We present a stochastic, swarm intelligence-based optimization algorithm for the prediction of global minima on potential energy surfaces of molecular clusterstructures. Our optimization approach is a modification of the artificial bee colony (ABC) algorithm which is inspired by the foraging behavior of honey bees. We apply our modified ABC algorithm to the problem of global geometryoptimization of molecular clusterstructures and show its performance for clusters with 2–57 particles and different interatomic interaction potentials

Micro-embossing of micro-structures in RSA-501 as mold inserts for the replication of micro-lens arrays

The production of mold inserts for the replication of micro-lens arrays through micro-embossing could be an alternative process route compared to diamond turning or milling in order to reduce time and costs. The rapidly solidified aluminum alloy RSA-501 is expected to form micro-structures with low surface roughness because of its ultra-fine grain structure. In micro-embossing challenges like elastic spring back effect, pile-ups, and forming accuracy depend on the material behavior. Therefore, RSA-501 was further characterized and the influence of polishing or flycutting on the material behavior was investigated. To further understand the grain and microstructure samples were sectioned along their cross and longitudinal directions. The grain structure of RSA-501 was oriented along the extrusion direction and the mean grain sizes were <1.00 μm. Furthermore, RSA-501 was micro-embossed to investigate the influence of the material behavior and surface preparation on the forming of micro-structures. The induced surface integrity through flycutting was not deep enough to influence the forming of micro-structures. Therefore, the workpiece surface can be prepared either by polishing or flycutting. When micro-embossing RSA-501, cross and longitudinal sections can be used. However, it is recommended to process the cross section because of its isotropic grain structure. It was shown that the curvature radius of micro-embossed concave structures differs from the tool radius. This is due to the elastic spring back effect. Since the embossed structure remains spherical, the spring back effect can be compensated by adjusting the tool radius

Contradictory antecedent debugging in bounded model checking

In the context of formal verification Bounded Model Check-ing (BMC) has shown to be very powerful for large industrial designs. BMC is used to check whether a circuit satisfies a temporal property or not. Typically, such a property is for-mulated as an implication. In the antecedent of the property the verification engineer specifies the assumptions about the design environment and joins the respective expressions by logical AND. However, the overall conjunction may have no solution, i.e. the antecedent is contradictory. Since in this case a property trivially holds this situation has to be avoided. Furthermore, the root cause of a contradictory an-tecedent has to be identified which is a manual and very time-consuming process. In this paper we propose a fully automatic approach for presenting all reasons of a contradictory antecedent to the verification engineer, i.e. the approach pinpoints to the sub-expressions in the antecedent that form a contradiction. Hence, our approach reduces the debugging time of a con-tradictory antecedent significantly