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Abstract

Present paper focuses on the modeling of size effect on the compressive strength of normal strength concrete with the application of discrete element method, considering specimen of different concrete mixes and shapes. An equation was derived to estimate the parallel bond strength from the compressive strength. The results showed a good agreement with the literature and the derived estimation models showed strong correlation with the measurements. The results indicated that size effect is stronger on concretes with lower strength class and that it is more significant on cube specimens than on cylinders. The relationship of model size and computational time was analyzed and a method to decrease the computational time (iterations) was proposed.

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Journal of Behavioral Addictions
Authors: Joseph Studer, Simon Marmet, Gerhard Gmel, Matthias Wicki, Florian Labhart, Céline Gachoud, Jean-Bernard Daeppen, and Nicolas Bertholet

Abstract

Background and Aims

There are concerns about the potential impact of the coronavirus disease (COVID-19) pandemic on substance use (SU) and other reinforcing behaviours (ORB). This paper investigates changes in SU and ORB among young men during the COVID-19 crisis (i.e. March–June 2020).

Methods

Before and during the COVID-19 crisis, 2,344 young Swiss men completed questionnaires covering SU (i.e. alcohol, cigarettes, illegal cannabis), ORB (i.e. gaming, watching TV series, internet pornography) and sociodemographic and work-related characteristics (i.e. deterioration in the work situation, change in working hours, change in working hours from home, healthcare workers’ and other professionals’ contacts with potentially infected people, linguistic region, call up to military or civil protection unit, living situation, age).

Results

Latent-change score models showed significant decreases of 17% for drinking volume and frequency of heavy episodic drinking, and a significant increase of 75% for time spent gaming and watching TV series. Subgroups showed greater relative increases. French-speaking participants, those who experienced a deterioration in their work situation and healthcare workers in contact with potentially infected people reported increased cigarette use. Those without children increased gaming, whereas those who worked fewer hours, experienced a deterioration in their work situation or were French-speaking did more gaming and watched more TV series. Those who lived alone or were German-speaking watched more internet pornography.

Conclusion

During the COVID-19 crisis, young Swiss men drank less alcohol and spent more time gaming and watching TV series. Changes in SU and ORB were not homogenous in the young Swiss men population.

Open access

Let (M, [g]) be a Weyl manifold and TM be its tangent bundle equipped with Riemannian g−natural metrics which are linear combinations of Sasaki, horizontal and vertical lifts of the base metric with constant coefficients. The aim of this paper is to construct a Weyl structure on TM and to show that TM cannot be Einstein-Weyl even if (M, g) is fiat.

Open access

Abstract

With the development of economic globalization and the information age, architecture has gradually become a kind of seal of politics, capital and culture, and is divorced from the spirit and life experience of the existing places in the region. Therefore, the field of architecture constantly seeks new research paradigm from the interdisciplinary perspective and reconsiders the creative activities of architecture. From the late last century, with the introduction of architecture by postmodern philosophy, semiotics, geographical psychology, phenomenology and cultural anthropology, there has been a cross-research between architecture and narratology. The recent research hopes to conduct an in-depth analysis of the theory of architectural spatial narrative and its development in the context of complex disciplines, and to research spatial narrative as a design methodology for architecture.

Open access

Abstract

Supply chain management intends to integrate supply chains' activities such as material flow, information flow and financial issues. Material flow management is the most significant issue since the inventory level in the whole supply chain could be optimized by an integrated plan. In other words, when one member of the supply chain plans to reduce its inventory level solely, despite reducing inventory in this node the inventory will be stocked in other partners' warehouses. Therefore, in this paper a new mathematical model has been developed to facilitate the process of finding the optimum solution in economic production, purchase and delivery lots and their schedules in a three-echelon supply chain environment; including raw material in suppliers, manufacturer and assembly facility as a customer. The manufacturer with a flow shop system provides its requirements from supplier, assemble multiple products, and delivers products to the customer (automotive OEM alike) on an optimum multiple delivery points. The delivery cycles would be identified through the production common cycle regarding the supply chain flexibility. Finally, a modified real-valued Genetic Algorithm (MRGA), and an Optimal Enumeration Method (OEM) are developed, and some numerical experiments have been done and compared as well.

Open access

We give all functions ƒ , E: ℕ → ℂ which satisfy the relation

ƒ(a2+b2+c2+h) =E(a) +E(b) +E(c) +K

for every a, b, c ∈ ℕ, where h ≥ 0 is an integers and K is a complex number. If n cannot be written as a2 + b2 + c2 + h for suitable a, b, c ∈ ℕ, then ƒ (n) is not determined. This is more complicated if we assume that ƒ and E are multiplicative functions.

Open access
Journal of Behavioral Addictions
Authors: Clémence Cabelguen, Bruno Rocher, Juliette Leboucher, Benoît Schreck, Gaëlle Challet-Bouju, Jean-Benoît Hardouin, and Marie Grall-Bronnec

Abstract

Background and aims

Since June 2018, gaming disorder (GD) has been recognized as a disease. It is frequently associated with attention deficit hyperactivity disorder (ADHD), as there are common vulnerability factors and bidirectional interactions between the two disorders. This study aims to evaluate the presence of ADHD symptoms and predictive factors of ADHD among patients with GD.

Methods

Ninety-seven patients ≥16 years old referred to the University Hospital of Nantes between 2012 and 2020 for GD were included. The diagnosis of GD was given a posteriori in accordance with the new ICD-11 GD definition. ADHD was screened using the Adult-ADHD Self-Report Scale and the Wender-Utah Rating Scale. A multivariate logistic regression model was used to identify explanatory factors for ADHD-GD comorbidity.

Results

The rate of GD patients who screened positive for ADHD was 39%. Predictive factors of ADHD-GD comorbidity were impulsivity (higher score on the negative urgency dimension) and low self-esteem.

Discussion

The rate of ADHD found among patients with GD is consistent with that from the literature on internet GD but higher than that found for other behavioural addictions. The identification of a higher negative urgency score and low self-esteem as predictive factors of AHDH-GD comorbidity indicates that gaming could be considered a dysfunctional way to cope with emotional dysregulation in ADHD or to virtually escape.

Conclusions

Comorbid ADHD must be taken into consideration to minimize its functional impact on GD patients and gaming-related damage. In contrast, the evaluation of gaming habits in patients with ADHD could be useful for both prevention and care.

Open access

In this article, we study a fractional control problem that models the maximization of the profit obtained by exploiting a certain resource whose dynamics are governed by the fractional logistic equation. Due to the singularity of this problem, we develop different resolution techniques, both for the classical case and for the fractional case. We perform several numerical simulations to make a comparison between both cases.

Open access

The main aim of this paper is to prove that the nonnegativity of the Riesz’s logarithmic kernels with respect to the Walsh– Kaczmarz system fails to hold.

Open access

Abstract

This paper seeks to compare the academic model of ‘militant democracy’ advocated in 1937 by Karl Loewenstein with the real political developments that had taken place only a few years before in Austria, under the responsibility of Engelbert Dollfuß. It further aims to to reveal the ‘missing link' between the actions (mere plans included) of - in particular - Catholic political leaders in Germany 1931/1933 (Heinrich Brüning, Franz v. Papen, Heinrich Held), directed at least from 1932 onwards in particular against the rise of the National Socialist movement, well-known both to Loewenstein and Dollfuß. It is argued that Loewenstein's model contains serious theoretical flaws and paves, at least when taken literally, the way to dangerous exaggerations, while the approach of the Dollfuß government was far more balanced. Any assessment of Dollfuß’ measures that – as is still the case in Austria – only focuses on the breach of the constitution then in force (the main document being the Bundes-Verfassungsgesetz, B-VG) as such, without offering a better alternative to prevent the National Socialist danger is unconvincing, not only from a moral, but also, and in particular, from a legal perspective.

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