Graph spaces of first-order linear partial differential operators

Symmetric positive systems of first-order linear partial differential equations were introduced by K.O. Friedrichs (1958) in order to treat the equations that change their type, like the equations modelling the transonic fluid flow. Recently, some progress in their understanding has been made by rewriting them in terms of Hilbert spaces, characterising the admisible boundary conditions by intrinsic geometric conditions in the graph spaces. In this paper we streamline the available proofs of the properties of graph spaces (most completely presented by M. Jensen (2004)), providing some additional results in the process; thus paving the way for further study of Friedrichs\u27 systems

Procurement at Local Government Level – Issues and Controversies

Local government, as administrative units, performs a broad range of services that require to establish relations with outside partners, including those belonging to the private sector. Public procurement, due to the size of the involved financial flows, is government activity especially exposed to inefficiencies, corruption and dishonesty. There is an everlasting discussion on the ideal size and the range of services to be kept ‘in-house’ of local government units (LGUs).Transaction Costs Economics (TCE) represents a theoretical paradigm specially designed to interpret the issue of efficiency in inter-institutional relations. However, even though TCE might be envisaged as a tool for building better systems and institutions, practical experience suggests that efficient organization of complex multi-institutional systems is still a goal to be met. Therefore, public procurement procedures at LGU level are suitable to analyze the transaction costs. In an attempt to determine the main organizational features of the existing scope of institutions/entities involved in delivering services to citizens, we provided an overview of the complexity of inter-organizational relations at LGU level.In this paper, we present results of an empirical research of public procurement procedures from the perspective of LGUs in Croatia. Picking up on questionnaire responses from 200 LGUs that reported having held over 350 cases of providing services through contract agreements with ‘independent’ service providers, we formed an opinion of what could be the consequences of developing more structured public procurement procedures

Specifics of Shafting Alignmentfor Ships in Service

Modern ships are means of transport which, during their entire operational lifespan, need to convey cargo and/or passengers in a safe and reliable way, without jeopardising their safety, and with least possible adverse impacts on the marine environment. The ship’s safety and functionality directly depend on the reliability of her propulsion system, the shafting being the essential unit of the system. The functionality of the ship’s shafting considerably depends on its correct installation. Installation of the ship propulsion shafting is an integral part of the overall positioning (alignment) procedure. Shafting alignment is performed in several stages, starting with the shaft line design, and includes calculating the elastic line and bearing loads, installation of shafting parts onboard ship in compliance with the calculation results, and verifying the alignment results. Procedures are different for ships in service and newly built ships. This paper deals with specific features of the propulsion shafting alignment that is carried out while a ship in service is being converted for a general reason. Unlike a newly built ship, an existing ship imposes additional constraints that should be dealt with in the calculation stage of the process as well as during shafting installation and alignment verification. A calculation approach for ships in service is always different, having specific features from case to case, depending on what is changed and what remains unchanged during the conversion of the ship. The same goes for the implementation and verification of the achieved results. The purpose of this paper is to underline the difference, its contribution being in suggesting the procedure to be followed in case of conversion of an existing vessel. KEY WORDS: ship in service, shafting, alignment, GAP, SA

Estimating Sedimentation of Glycogen through Linear Concentration Gradient of Glycerol Solution

A set of tables is presented for predicting the position of a glycogen particle in linear glycerol density gradient centrifugation. Data about the size and sedimentation coefficient are given

Estimating Sedimentation of Glycogen through Linear Concentration Gradient of Glycerol Solution

A set of tables is presented for predicting the position of a glycogen particle in linear glycerol density gradient centrifugation. Data about the size and sedimentation coefficient are given

H-Distributions: An Extension of H-Measures to an Lp-Lq Setting

We use the continuity of Fourier multiplier operators on Lp to introduce the H-distributions—an extension of H-measures in the Lp framework. We apply the H-distributions to obtain an Lp version of the localisation principle and reprove the Murat Lp-Lp′ variant of div-curl lemma

Graph spaces of first-order linear partial differential operators

Symmetric positive systems of first-order linear partial differential equations were introduced by K.O. Friedrichs (1958) in order to treat the equations that change their type, like the equations modelling the transonic fluid flow. Recently, some progress in their understanding has been made by rewriting them in terms of Hilbert spaces, characterising the admisible boundary conditions by intrinsic geometric conditions in the graph spaces. In this paper we streamline the available proofs of the properties of graph spaces (most completely presented by M. Jensen (2004)), providing some additional results in the process; thus paving the way for further study of Friedrichs\u27 systems

One-scale H-distributions and variants

H-measures and semiclassical (Wigner) measures were introduced in earlyn 1990s and since then they have found numerous applications in problems involving $\mathrm{L}^2$ weakly converging sequences. Although they are similar objects, neither of them is a generalisation of the other, the fundamental difference between them being the fact that semiclassical measures have a characteristic length, while H-measures have none. Recently introduced objects, the one-scale H-measures, generalise both of them, thus encompassing properties of both. The main aim of this paper is to fully develop this theory to the $\mathrm{L}^p$ setting, $p\in(1,\infty)$, by constructing one-scale H-distributions, a generalisation of one-scale H-measures and, at the same time, of H-distributions, a generalisation of H-measures to the $\mathrm{L}^p$ setting, without any characteristic length. We also address an alternative approach to $\mathrm{L}^p$ extension of semiclassical measures via the Wigner transform, introducing new type of objects (semiclassical distributions). Furthermore, we derive a localisation principle in a rather general form, suitable for problems with a characteristic length, as well as those without a specific characteristic length, providing some applications.Comment: 41 pages, 3 figure

Online shopping determinants of Croatian consumers

Understanding consumer behavior is one of the focal points of decision theory. Over the past decade, a substantial increase in the popularity of online shopping has been observed worldwide. The significant acceleration of this trend can be attributed to the COVID-19 pandemic, which affected consumers’ traditional shopping behavior and forced them to shop without visiting physical stores. The increasing popularity of online shopping necessitated a better understanding of the factors driving behavior. In this research, based on a sample of 394 respondents, we aimed to find influential socio-demographic factors that affect online shopping habits and decision-making. To this end, we constructed a binary logistic regression model to estimate the influence of socioeconomic factors on online purchasing decisions. To support the logistic regression model results, we examined significant differences in views on online shopping among socio-demographic subgroups. Statistically significant influences on online shopping decisions include a person’s age, education level, and employment status. Gender and urbanization level of residence showed no influence on online shopping behavior