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Abstract: The paper deals with the dynamics of a resistance spot welding system. At the core of this system is a transformer, which is powered on the primary side by a pulse-width modulated inverter and has a full-wave output rectifier on the secondary side that provides a direct welding current. The entire system is nonlinear, due to magnetic hysteresis and electronics. The electronics prevent the current from flowing in all parts of the welding transformer at separate time intervals during the voltage supply period; therefore, not all the parameters affect the dynamic of currents and voltages all the time so the system is also time-variant. To design a high-performance welding system and to predict the maximum possible welding current at a specific load, it is necessary to know the welding and primary currents. The leakage inductances of the system can reduce the maximum welding current significantly at higher frequencies and the same load. There are several methods to determine these currents, each with its drawbacks. Measurements are time-consuming, using professional software is expensive and requires time to learn and free open-source software has many limitations and does not guarantee the correctness of the results. The article presents a new, fourth option—a theoretical derivation of analytical expressions that facilitate straightforward and rapid calculation of the welding and primary currents of the resistance spot welding system with symmetrical secondary branches. The derivation of the mathematical expressions is based on the equivalent circuits that describe the system in different operating states. The results of the numerical simulations confirmed the derived expressions completely.
Keywords: DC–DC converters, pulse width modulation (PWM), welding transformers, center-tapped transformers, full-wave rectifier, resistance spot welding (RSW), leakage inductance, analytical modeling, time-variant system, equivalent circuit
Published in DKUM: 08.08.2024; Views: 77; Downloads: 45
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Abstract: Purpose: The purpose of this article is to present an overview of inmates’ treatment in Slovenia. After the introduction a brief discussion of terms is presented. The overview then takes a historical focus followed by a more detailed description of current treatment in Slovenia. Design/Methodology/Approach: The paper is based on a literature review and on a conducted interview. Findings: Slovenian penal institutions are dominated by compromise between treatment and punishment policy. The treatment, however, can be implemented only to the degree that is permitted by the security measurements in the penal institution. Therefore, Slovenia was and still is confronted with a question: what kind of punishment and inmates’ treatment practice would be most effective? Research limitations/implications: The lack of literature on inmates’ treatment in Slovenia published in recent years was the main issue the authors have to deal with. Therefore the interview with treatment personnel was conducted. Practical implications: Taking into account a chronological overview of inmates’ treatment in Slovenia, the paper reflects the inmates’ treatment in Slovenian society today. Originality/Value: This paper attempts to provide a broad overview of Slovenian treatment of inmates. It may be important to non-academic policy makers, students as to academics interested in gaining some knowledge about Slovenia’s past and present prison treatment policies.
Keywords: treatment, rehabilitation, resocialization, inmates, prison, Slovenia Full article
Published in DKUM: 12.05.2020; Views: 1082; Downloads: 53
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Abstract: External aerodynamics plays an important role in improving road vehicles efficiency. In the field of computational fluid dynamics (CFD), relatively basic and often inaccurate turbulence models are typically used in the industry. In this work, the Partially-Averaged-Navier-Stokes (PANS) method is used to show its applicability for industrial purposes. An air flow past two distinct geometrical models has been simulated using AVL FIRE and results have been compared with available measurements. The results show that the accuracy is vastly improved in comparison with conventional turbulence models. In modern external aerodynamics applications, the PANS model has the potential to be more widely used.
Keywords: aerodynamics, PANS, full-scale, advanced modelling
Published in DKUM: 28.11.2019; Views: 1061; Downloads: 116
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Abstract: In December 2016, Member States need to implement the Antitrust Damages Directive. The Directive adopts the full compensation principle and expressly prohibits overcompensation. I will embark on an enquiry whether such an approach departs from the Slovene general regime of civil liability, in particular liability in damages. At face value, one might argue that the Slovene civil liability regime prohibits non- compensatory rationales for awarding damages. This article challenges this perception. It argues that there is a space for interpreting the rationale for damages in the Slovene private law, when this is justified with dissuasiveness and sufficient reasons are given, as well as embracing non- compensatory considerations, prevention and deterrence in particular. Regrettably, the judiciary does not necessarily keep in step with such an interpretation. However, there are tendencies in the legal scholarship to change the established case law. In this setting, the special liability regime based on the Directive, which prohibits overcompensation, can be seen as an exception to the general regime for damages awards in certain contexts. This approach is contrasted with damages awards regime in the labour law context, which is also based on the EU regulation. In this context, the Slovene legislator expressly embraced prevention and deterrence as rationales for the award of damages. Thus, legislation which is based on or influenced by EU law can lead to different outcomes in practice. It can either reinforce preventive tendencies of the general regime of civil liability or, as it is seen in the competition law context, undermine them. Nevertheless, the (proposed) Slovene implementing legislation opts for a solution that accommodates both the Antitrust Damages Directive and the general regime of civil liability.
Keywords: Antitrust Damages Directive, civil liability, damages, full compensation, prevention, deterrence
Published in DKUM: 02.08.2018; Views: 1149; Downloads: 81
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Abstract: Unemployment negatively affects the government budget and inflicts costs on the unemployed individuals as well as on the society as a whole in many ways. The direct costs of unemployment for the state budget arise due to the benefits paid out to the unemployed, and due to foregone direct and indirect taxes. On the level of an individual, nonmonetary costs are a multiple of the monetary ones, which indicates that employment plays a central role in a person’s well-being. Unemployment has a spill-over effect on the society as a whole and affects not only the unemployed, but also the employed population, particularly in the areas experiencing high unemployment rates. We take the case study of Germany, the country often used as a quintessence of how to overcome the problem of massive unemployment. Before the four Hartz reforms, which were implemented in years 2003, 2004 and 2005, Germany was characterized as the »sick man of Europe« owing to its exploding levels of unemployment, dysfunctional labor market, unsustainable social budget, and rising public debt. As the reforms were put into force, the situation in the German labor market underwent a 360° turnaround and became portrayed as the »German economic miracle«. The true effects of the reforms fully transpired in the economic and financial crisis of 2008/2009, when most countries experienced escalating unemployment rates, while Germany kept them at bay. Studies show that flexible working-time arrangements and short-time work have played a major role in inhibiting lay-offs in German companies during the recent crisis, and hence in preventing a spike in unemployment rates, which we use as one of the points that validate our Model of employment. The government subsidies made it possible for companies to reduce the working hours of their employees instead of laying them off. An important feature of the German labor market is a comparatively high percentage of part-time workers (around 25% in years 2006–2011), which also explains the low unemployment rates Germany has been recording since the reforms were introduced. The reforms cut the amount and duration of unemployment benefits, which gave the unemployed more incentives to find a job. A negative aspect of the reform may be an increased divide between the core work force and the marginal workers, which intensifies social differences and is currently on the agenda of German politics. Also some researches stress the importance of social cohesion and that the risks and opportunities in the labor market should be more evenly distributed. In the accompanying explanations to the Model of employment, some of the successful measures of Germany’s Hartz reforms may be spotted, while at the same time we avoid the »mistakes« of these reforms, thus making sure that social differences among people would narrow down upon the real-life implementation of the Model. When the number of job vacancies sharply exceeds the number of unemployed, and when there are poor prospects of new job openings in the near future, the only viable solution to the problem of unemployment is to reduce the working hours of the existing employees. The Model of employment that we develop represents a possible solution to the problem of unemployment and thus addresses the need to reduce the costs of unemployment to the unemployed individual, to the state budget, and to the society as a whole. The crux of the Model is a re-distribution of the total number of workplaces and total annual working hours among the »new actively employed population«, which comprises all persons having the potential to become or stay employed or self-employed in a given year. The model allows for a flexible arrangement of working hours – from four and up to eight hours per employee per day. Our solution will release the working hours, make them available to the currently unemployed, and hence ensure a more equitable distribution of income and work load amongst the population. In addition, as the workers will be less tired and stressed-out, their productivity will in
Keywords: unemployment, labor force, labor market, part-time employment, full-time employment, labor market flexibility, costs of unemployment, Hartz reforms
Published in DKUM: 30.08.2013; Views: 2601; Downloads: 176
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