Benchmarking Practical RRM Algorithms for D2D Communications in LTE Advanced

Device-to-device (D2D) communication integrated into cellular networks is a means to take advantage of the proximity of devices and allow for reusing cellular resources and thereby to increase the user bitrates and the system capacity. However, when D2D (in the 3rd Generation Partnership Project also called Long Term Evolution (LTE) Direct) communication in cellular spectrum is supported, there is a need to revisit and modify the existing radio resource management (RRM) and power control (PC) techniques to realize the potential of the proximity and reuse gains and to limit the interference at the cellular layer. In this paper, we examine the performance of the flexible LTE PC tool box and benchmark it against a utility optimal iterative scheme. We find that the open loop PC scheme of LTE performs well for cellular users both in terms of the used transmit power levels and the achieved signal-to-interference-and-noise-ratio (SINR) distribution. However, the performance of the D2D users as well as the overall system throughput can be boosted by the utility optimal scheme, because the utility maximizing scheme takes better advantage of both the proximity and the reuse gains. Therefore, in this paper we propose a hybrid PC scheme, in which cellular users employ the open loop path compensation method of LTE, while D2D users use the utility optimizing distributed PC scheme. In order to protect the cellular layer, the hybrid scheme allows for limiting the interference caused by the D2D layer at the cost of having a small impact on the performance of the D2D layer. To ensure feasibility, we limit the number of iterations to a practically feasible level. We make the point that the hybrid scheme is not only near optimal, but it also allows for a distributed implementation for the D2D users, while preserving the LTE PC scheme for the cellular users.Comment: 30 pages, submitted for review April-2013. See also: G. Fodor, M. Johansson, D. P. Demia, B. Marco, and A. Abrardo, A joint power control and resource allocation algorithm for D2D communications, KTH, Automatic Control, Tech. Rep., 2012, qC 20120910, http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-10205

Encapsulation of human serum albumin in submicrometer magnetic poly(lactide-co-glycolide) particles as a model system for targeted drug delivery

Two types of iron oxide nanoparticles were synthesized by coprecipitation of Fe(II) and Fe(III) chlorides: water-dispersible γ-Fe2O3 and organic solvent-dispersible oleic acid-coated Fe3O4 particles. The nanoparticles, together with human serum albumin (HSA) serving as a model for a protein-type drug, were then incorporated in poly(lactide-co-glycolide) (PLGA) particles using double emulsion solvent evaporation technique. Morphology, size and particle size distribution of the resulting particles was analyzed by electron microscopy and dynamic light scattering. Iron oxide and HSA encapsulating efficiency was determined by Prussian Blue staining and micro-BCA assay, respectively

Nem az iskolának, hanem az életnek tanulunk

The concept of psychological capital has a central role in both positive psychology and economics, and can be defined as follows: “the state of positive psychological development of an individual, which builds on the following elements: self-efficacy, optimism, hope and resilience” (Nagy, 2017). Similarly, entrepreneurial competence is also associated with human capital, and is one of the eight key competences required for lifelong learning as defined by the European Union. Both factors are at play in the individual’s performance at school and work, satisfaction and in the pursuit of a happier life. Our research aims to present the role of psychological capital and entrepreneurial competence in the labour market and education, as well as the relationship between psychological capital, entrepreneurial competence and school performance. The survey was conducted with the participation of 342 students from grammar school, economic high school or other high schools. A questionnaire was used in the survey, including multiple subparts: questions on performance, General Self-efficacy Scale, Life Orientation Test, Hope Scale, Brief Resilience Scale, Entrepreneurial competence questionnaire and test on financial knowledge. Our research found a significant positive correlation between psychological capital, entrepreneurial competence and school performance. Our cluster analysis revealed 3 separate groups with completely different psychological capital profiles. By using the SEM model, we managed to identify self-efficacy, flexibility and the combination of hope and motivation as the direct sources of entrepreneurial competence. It can be concluded that individuals possessing a higher level of psychological capital have higher entrepreneurial competence and better school achievement. In our view, public education should – by embracing the approach of positive psychology – take a prominent role in teaching students how to recognise and enrich their personal competences, whereby their performance and well-being can also be improved.Mind a pozitív pszichológiában, mind a közgazdaságtanban központi helyet foglal el a pszichológiai tőke fogalma, Nagy (2017) meghatározása szerint „egy egyén pozitív pszichológiai fejlettségi állapota, amely a következő elemekből építkezik: önhatékonyság, optimizmus, remény, reziliencia”. A humán tőkéhez kapcsolható fogalom a vállalkozói kompetencia is, amely az Európai Unió által megfogalmazott, egész életen át tartó tanuláshoz szükséges nyolc kulcskompetencia egyike. Mindkét tényező szerepet játszik az egyén iskolai és munkahelyi teljesítményében, elégedettségében, valamint a boldogabb élet elérésében. Kutatásunk célja, hogy bemutassuk a pszichológiai tőkének és a vállalkozói kompetenciának a munkaerőpiacon és az oktatásban betöltött szerepét, valamint a pszichológiai tőke, a vállalkozói kompetencia és a teljesítmény közti kapcsolatot. Az adatfelvételt 342 gimnazista, gazdasági középiskolás és egyéb középiskolába járó diák körében végeztük. A lekérdezés módszere kérdőíves felmérés volt, amely több részből épült fel: teljesítménnyel kapcsolatos kérdések, Általános Énhatékonysági Skála, Életszemlélet Teszt, Remény Skála, Rövid Reziliencia Skála, Vállalkozói kompetencia teszt, Pénzügyi ismeret teszt. Kutatásunk eredményeként pozitív szignifikáns kapcsolatot mutattunk ki a pszichológiai tőke, a vállalkozói kompetencia és az iskolai teljesítmény között. Klaszterelemzéssel sikerült beazonosítanunk 3 különböző csoportot, amelyek a pszichológiai tőke minden elemében különböztek egymástól. A SEM modell alapján meghatároztuk, hogy a vállalkozói kompetencia közvetlenül az énhatékonyságból, a rugalmasságból és a remény-hajtóerő kettőséből táplálkozik. Összegzésképpen megállapíthatjuk, hogy a pszichológiai tőke magasabb szintjével rendelkező egyének magasabb vállalkozói kompetenciával rendelkeznek és jobb teljesítmény nyújtására képesek. A közoktatás egyik fontos feladatának tartjuk, hogy a pozitív pszichológiai személetmód oktatásba történő beépítésével megtanítsuk a diákokat személyes kompetenciáik felismerésére, gyarapítására, melyen keresztül a teljesítményük és a jóllétük is növekedhet

Preparation of Veterinary Premix with Dual Active Ingredients in Granular Form

The aim of the study was to investigate the preparation of granular veterinary premix containing two different antibiotics by fluid bed granulation process. The particle size and density of the active ingredients were investigated for the proper selection of the filler material. The used antibiotics were tylosin tartarate and colistin sulfate, while isomalt sugar alcohol and cellulose materials were selected as filler and binder, respectively. The colistin sulfate was fed together with the binder solution because of its low density, fine particle size and relatively low (1.2%) concentration in the product. The type and concentration of the binder in its solution, the feeding rate and the total amount of added binder solution were optimized for obtaining dust free granules with desirable abrasion resistance and good flowability. The active ingredient content for both antibiotics was preserved even at the elevated temperature applied during the fluid granulation process