The Potential Dual Use of Online Pharmacies

The technological advances of the 20th century resulted in the creation of the Internet and its introduction into everyday life on a global scale. The Internet provides access to information and the sale and purchase of goods. Medications are also subject to trade. Their sale is conducted by online pharmacies and their global turnover amounts to hundreds of billions of dollars. Medications ordered over the Internet are sent by mail all over the world. Considering the events of recent years, we cannot exclude the risk of a terrorist attack through online pharmacies. Terrorists can establish such companies, legally or illegally, or acquire ones already existing. Parcels, which are highly trusted by the customers of online pharmacies, can, for example, be contaminated with dangerous materials. The sale of online medications in the international system is potentially dangerous and requires international regulation.     

Socratic Proofs

Journal of Philosophical Logic - Our aim is to express in exact terms the old idea of solving problems by pure questioning. We consider the problem of derivability: “Is A derivable from...     

A Method of Generating Modal Logics Defining Jaśkowski’s Discussive Logic D<Subscript>2</Subscript>

Ja?kowski’s discussive logic D₂ was formulated with the help of the modal logic S5 as follows (see [7, 8]): \({A \in {D_{2}}}\) iff \({\ulcorner\diamond{{A}^{\bullet}}\urcorner \in {\rm S}5}\), where (–)^? is a translation of discussive formulae from For^d into the modal language. We say that a modal logic L defines D₂ iff \({{\rm D}_{2} = \{A \in {\rm For^{\rm d}} : \ulcorner\diamond{{A}^{\bullet}}\urcorner \in {\it L}\}}\). In [14] and [10] were respectively presented the weakest normal and the weakest regular logic which (?): have the same theses beginning with ‘\({\diamond}\)’ as S5. Of course, all logics fulfilling the above condition, define D₂. In [10] it was prowed that in the cases of logics closed under congruence the following holds: defining D₂ is equivalent to having the property (?). In this paper we show that this equivalence holds also for all modal logics which are closed under replacement of tautological equivalents (rte-logics).We give a general method which, for any class of modal logics determined by a set of joint axioms and rules, generates in the given class the weakest logic having the property (?). Thus, for the class of all modal logics we obtain the weakest modal logic which owns this property. On the other hand, applying the method to various classes of modal logics: rte-logics, congruential, monotonic, regular and normal, we obtain the weakest in a given class logic defining D₂.     

A Study in Grzegorczyk Point-Free Topology Part II: Spaces of Points

Studia Logica - In the second installment to Gruszczyński and Pietruszczak (Stud Log, 2018. https://doi.org/10.1007/s11225-018-9786-8 ) we carry out an analysis of spaces of points of...     

Two-dimensional Langevin approach to the human stabilogram

Two-dimensional Langevin equation is considered as a model of the center of pressure (COP) random walk at quiet standing condition. The matrix of the mean square displacement describes quantitatively the COP random walk. Twenty-six young subjects were included in the study. Elements of the matrix of the mean square displacement derived from experimental data are well approximated by theoretical expressions derived from the Langevin equation, in the short-term regime. We have studied statistical properties of the COP displacements. Non-Gaussian behaviour of the displacements is indicated by the characteristic functions. New coordinate system constituted and utilised by the postural control system (PCS) was found for every subject. This new coordinate system is turned with respect to the system defined by the anatomy of the body. In this new coordinate system the matrix of the mean square displacement takes the form close to diagonal. The status of PCS in this new coordinate system can be quantified by the elements of the diffusion matrix, which are the measure of the stochastic activity of that system, rotation angle of new coordinate system and the friction coefficient. We have applied this analysis to examine how the visual inputs affect the PCS. We have found that the stochastic activity of the PCS increases after exclusion of the visual inputs. We have also shown that the visual system does not affect the friction coefficient. Furthermore, we have found that orientation of the new coordinate system chosen by PCS at included visual inputs differs from the orientation at excluded visual inputs.     

The Distance Function in Commutative ℓ-semigroups and the Equivalence in Łukasiewicz Logic

The equivalence connective in ukasiewicz logic has its algebraic counterpart which is the distance function d(x,y) =|x–y| of a positive cone of a commutative -group. We make some observations on logically motivated algebraic structures involving the distance function.     

The impact of emotions on shopping behavior during epidemic. What a business can do to protect customers

The study investigated how the perception of in‐shop COVID‐19 contraction influences emotions in decision‐making and how they further effect actions undertaken by consumers to control the situation within a store. Structural equation modeling was used to study the relationship between the risk of in‐store infection, emotions and in‐shop behavior, based on data retrieved from 914 questionnaires. Results showed, that the perceived risk of becoming infected in a store causes an increase in arousal and, at the same time, a decrease in perceived pleasure during shopping. The rise in arousal led to an increase in consumers taking actions to decrease their risk of contagion, while an increase in noticeable pleasure lowered interest of following recommendations for pandemic behavior. The findings imply that through changes regarding in‐store atmosphere, stationary shops can provide consumers with a sense of urgency and awareness of infection risk so that they may do their shopping more efficiently.     

A Study in Grzegorczyk Point-Free Topology Part I: Separation and Grzegorczyk Structures

This is the first, out of two papers, devoted to Andrzej Grzegorczyk’s point-free system of topology from Grzegorczyk (Synthese 12(2–3):228–235, 1960.  https://doi.org/10.1007/BF00485101). His system was one of the very first fully fledged axiomatizations of topology based on the notions of region, parthood and separation (the dual notion of connection). Its peculiar and interesting feature is the definition of point, whose intention is to grasp our geometrical intuitions of points as systems of shrinking regions of space. In this part we analyze (quasi-)separation structures and Grzegorczyk structures, and establish their properties which will be useful in the sequel. We prove that in the class of Urysohn spaces with countable chain condition, to every topologically interpreted representative of a point in the sense of Grzegorczyk’s corresponds exactly one point of a space. We also demonstrate that Tychonoff first-countable spaces give rise to complete Grzegorczyk structures. The results established below will be used in the second part devoted to points and topological spaces.