Mobility-Aware, Correlation-Based Node Grouping and Selection for Cooperative Spectrum Sensing, Journal of Telecommunications and Information Technology, 2014, nr 2

Cooperative spectrum sensing has been proposed as a solution to increase the sensing function accuracy in cognitive radio networks, but the research has, so far, mainly focused on static scenarios, all but neglecting the impact of mobility on spectrum sensing. In this work a novel cooperative spectrum sensing scheme for mobile cognitive networks, based on a correlation-based, mobility-aware node selection algorithm is proposed. Correlation among sensing decisions is used to divide nodes into groups, and mobility is taken into account in the group leaders selection by means of a node selection metric that considers both sensing performance and mobility. Performance of the proposed algorithm is evaluated by computer simulations taking into account mobility and a detailed modeling of temporal and spatial correlation of fading and shadowing components in the channel path loss, going way beyond the performance evaluation carried out in previous works on correlation-based cooperative sensing schemes. Simulation results highlight that the proposed metric leads to a signi cant increase of the update period required to maintain acceptable sensing performance, and correspondingly to a strong reduction in the overhead caused by the grouping and node selection procedure

DVB-T Channels Measurements for the Deployment of Outdoor REM Databases, Journal of Telecommunications and Information Technology, 2014, nr 3

In this paper the analysis of the spectrum occupancy in the TV band is provided based on the outdoor measurements campaigns carried out in Poznań, Poland in 2013 and 2014. The goal of this work is to discuss the stability and other important features of the observed spectrum occupancy in the context of outdoor Radio Environment Maps database deployment. Reliable deployment of these databases seems to be one of the critical points in practical utilization of the TV White Spaces for cognitive purposes inside buildings and in densely populated cities. The results obtained for outdoor scenario are briefly compared with the previous measurements conducted indoors in Barcelona, Spain, and in Poznań, Poland

Positive left atrial remodeling in patients with paroxysmal atrial fibrillation after a successful radiofrequency pulmonary vein isolation

Background: The potential relationship between the initial left atrial (LA) echocardiographic parameters and LA remodeling after pulmonary vein isolation with RF energy (PVI) with effectiveness of this treatment is discussed. Aim: To determine the influence of initial and after follow-up transthoracic echocardiography derived predictors of successful PVI in patients with paroxysmal atrial fibrillation (AF). Methods: 80 patients with paroxysmal AF (58 [interquartile range, IQR], 50–63] years, males: 58 [IQR, 50–63]), hospitalized for the first time PVI procedure were included. Before and after a minimum of 6 months of follow-up period a clinical and echocardiographic evaluation were performed. LA morphological parameters (diameter, volumes and other detailed LA parameters), as well as LA peak segmental and global longitudinal strains (PLS) and LA wall strain synchrony were assessed. Results: In the whole group after a follow-up period, patients presented higher mean LA Volconduit. Patients with no AF recurrences had lower post-PVI LA volumes, higher LA ejection fraction and LA expansion index, when compared to the patients after ineffective PVI. Patients who maintained sinus rhythm after PVI procedure were characterized by a higher initial segmental strains: LA PLSbasal-inferior and PLSapical-septal, as well as higher LA wall strain dispersion in time. Conclusions: Some echocardiographic parameters related to LA morphology improve after successful PVI treatment. LA strains and wall strain dispersion in time are not related to LA remodeling after successful PVI procedure. However the baseline LA standard and novel echocardiographic parameters cannot be used as a remote evaluation of the effectiveness of the PVI procedure

Renalase is associated with adverse left atrial remodelling and disease burden in patients with atrial fibrillation undergoing pulmonary vein isolation

Background: Renalase is a catecholamine-metabolising enzyme, but its possible association with atrial fibrillation (AF) remains unknown. Aim: We sought to evaluate plasma renalase concentration in patients with AF undergoing pulmonary vein isolation (PVI) with respect to AF clinical characteristics, left atrial (LA) remodelling, and PVI efficacy. Methods: This case-control study included 69 patients (median age 58 years) with either paroxysmal (89%) or persistent (11%) AF, referred for PVI, and a control group consisting of 15 patients without AF, matched for age, sex, and comorbidi­ties. An evaluation of transthoracic echocardiography with LA speckle tracking and plasma renalase concentration using an enzyme-linked immunosorbent assay was performed. AF recurrence was defined as any AF episode on seven-day electro­cardiographic monitoring at six-month follow-up. Results: Renalase level was higher in the study group than in the control group (mean 27.99 vs. 21.48 μg/mL, p = 0.004), but it was lower in patients with persistent AF (19.05 vs. 28.77 μg/mL; p = 0.023) and among patients with AF episodes di­rectly preceding PVI (24.50 vs. 29.66 μg/mL; p = 0.04). Renalase concentration within the first quartile was associated with higher mean heart rate (70 vs. 61 bpm, p = 0.029), greater AF burden (36.9% vs. 9.3%, p = 0.027), greater LA diameter (41.1 vs. 37.9 mm, p = 0.011), and a trend towards less negative global LA strain (–9.4 vs. –13.5, p = 0.082). Logistic regres­sion revealed that global four-chamber LA strain was the only independent predictor of renalase variability (p = 0.0045). Renalase concentration did not predict AF recurrence at six-month follow-up (area under curve [AUC] = 0.614, p = 0.216). Conclusions: Low renalase level may be associated with impaired rate control, higher AF burden, and advanced LA remodel­ling in AF patients undergoing PVI, but it does not predict sinus rhythm maintenance

Canon Tables - Symbolism of the Architectural Decoration

Wydanie publikacji dofinansowane przez Komitet Badań NaukowychThis paper deals with the history of the development of canon tables in early medieval manuscripts. The author concentrates on the role of the architectural decoration of canon tables. This type of decoration was very important for the development of iconography, especially in Byzantium, where one can observe the tendency to expand the role of calligraphy on the cost of illumination. Canon tables were instrumental in propagation of the type oi composition (originating probably from astronomical codices of late antiquity) in which text is enclosed by an architectural frame. For the canon tables created after the 10th century characteristic is transition from tectonic to ornamental treatment of the frame. The motifs of antithetic animals (usually birds) and pair of trees placed next to the arcades ar? obligatory elements of the frame. This pattern deriving from the canon tables compositions belongs to the most widespread schemes in medieval illuminations.Zadanie pt. Digitalizacja i udostępnienie w Cyfrowym Repozytorium Uniwersytetu Łódzkiego kolekcji czasopism naukowych wydawanych przez Uniwersytet Łódzki nr 885/P-DUN/2014 zostało dofinansowane ze środków MNiSW w ramach działalności upowszechniającej naukę

Dookoła marginesu w osiemdziesiąt światów i dwadzieścia lat. Uwagi na temat paradoksalnej natury marginalności

This article obviously aims at messing around, checking if borderlines of disciplines can be ignored, so as not to lose sight of their margins. The increase in the interest in margins may be associated with the change of the cultural paradigm at the turn of 1980s and 1990s, the so-called “spatial turn”, i.e. a rediscovery of the cognitive indispensability of spatial meta-phors. This turn was also influenced by intrinsically ex-centric and centrifugal strivings of the avant-garde. However, a much greater incentive to deal with the topic is provided by the common uncertainty of our own position, role and usefulness in the global circulation of culture. A strong sense of marginalization or marginality in the culture described as global is paradoxical in the light of geometry’s “intuition-free” generalizations. There is no margin on the surface of a sphere, at most each point of the spherical space can be described as peripheral locality. And in each such locality, peripheral vicissitudes may occur and do occur, as dramatic as they are uninteresting to anyone outside the locality. It is quite a precise model – more geometrico – of the cultural processes which are most frequently called alienation, defamiliar-ization, disillusion, enstrangement or estrangement. Only having referred a margin to a triangle formed by the three terms остранение, Verfremdung, dépaysement, can we can fully under-stand the reasons for the constant fascination with the marginal.Celem artykułu jest oczywiście wprowadzenie bałaganu, sprawdzenie, czy możliwe jest igno-rowanie granic dyscyplin choćby po to, by ani na moment nie tracić z oczu marginesu. Wzrost zainteresowania marginesami, marginaliami da się powiązać z kolejną zmianą paradygmatu kultury na przełomie lat osiemdziesiątych i dziewięćdziesiątych XX wieku, tzw. zwrotem przestrzennym, czyli (ponownym) odkryciem dogodności poznawczej metafor przestrzennych. Rolę w przygotowaniu tego zwrotu odegrały też z natury eks-centryczne, odśrodkowe dążenia Awangardy. Choć o wiele silniej działającym bodźcem skłaniającym do zajmowania się tym tematem jest powszechna niepewność własnego usytuowania, własnej pozycji, roli i przydat-ności w globalnej cyrkulacji kultury. Silne poczucie marginalizacji czy marginalności w kul-turze określanej jako globalna jest – gdybyśmy chcieli konsekwentnie posługiwać się „wolną od intuicji” zdolnością geometrii do uogólniania – paradoksalne. Na powierzchni sfery nie jest możliwe wskazanie żadnego marginesu, co najwyżej da się każdy punkt kulistej powierzchni opisywać jako peryferyjną lokalność. I w każdej takiej lokalności mogą rozgrywać się i roz-grywają peryferyjne perypetie. Równie dramatyczne co nikogo spoza obrębu lokalności nie-obchodzące. Jest to dość dokładny model – more geometrico – procesów kulturowych, jakie najczęściej nazywa się alienacją czy atomizacją. Dopiero odniesienie marginesu do trójkąta utworzonego z tych trzech terminów: остра-нение Verfremdung, dépaysement, pozwala w pełni zrozumieć przyczyny ciągłej fascynacji tym, co marginalne. Margines to nazwa opisująca miejsca szczególnie atrakcyjne dla awangar-dowej chęci wzbudzania zaciekawienia i zdumienia. Powraca zagadnienie Awangardy jako formy kultury mającej samoświadomość własnego wyobcowania, czy własnej nieuniknionej odśrodkowej marginalności. Pojęcia Verfremdung, dépaysement i остранение ułatwiają zro-zumienie, co łączy tak typowe dla sztuki XX i XXI wieku zjawiska jak kolaż, montaż, defor-macja z marginesem i marginalnością. Dla lepszego określenia, jakie są dzisiejsze kulturowe kontury marginesu warto dodać jeden jeszcze termin w dwóch wariantach językowych: das Unheimliche/uncanny. Ludzką skłonność do przestrzennego wyobrażenia sobie abstrakcyjnej transcendencji jako czegoś podobnego, ale „sięgającego dalej” niż margines, wykraczającego poza marginalność, trzeba uznać za przyczynę z jednej strony fascynacji, z drugiej problematyczności marginesu i marginalności. Zastanawiając się nad granicami pojęcia margines można posłużyć się prostym modelem, w którym margines jest każdym miejscem przecięcia płaszczyzny postrzeganej diachronicznie z drugą, jaką odbieramy jako obszar synchronicznie pojawiających się zjawisk. Pierwsza z nich bliższa jest narracji, językowi, historii i upływowi czasu, druga ikoniczności, geometrii i rozległości przestrzeni. W takim modelu każdy punkt jest marginesem, kłopot pojawia się, gdy chcemy określić, czym jest w nim centrum

About Clever Ways of Being on the Watch for the Spirit. A Contribution to the Iconography of Liquidity

Answering the question whether it is possible to respect the spiritual, intelligi-ble, and rational while describing only what is visible, the author says yes, but only where both immaterial and material sides of the reality are objectified. One can use the intuition which once made J. W. Goethe admit in his Faust to be a “Peer of the spirit that you comprehend.” To be a peer of looks like to identify with. Identity, however, seems to be very airy. Almost like a ghost. The author then tries to “entangle” identity in matter by undertaking an attempt of liquefy-ing it. He notes that in culture the border between the spiritual and the liquid is leaky like a sieve due to linguistic metaphors. His proposal then is to archeolo-gize the human language in order to find out arguments for human intrinsic needs of imagining, speaking, and ruling over the whole which is in movement

Stereoselfie with mandrake

I have used a photo depicting Prof. Wanda Nowakowska hidden behind the mandrake as a pretext for considerations regarding a person herself and problems associated with “going in for” art history. An attribute may not only be an object distinguishing a particular person, but an ambiguous symbol, whose subsequent levels of understanding may be searched by immersing more and more deeply in tradition and history; looking for connections between what we see and what is characteristic of the human race. Reflection on the picture may only take form of its description, but it may also become a source of cognition, depending on competence and intention of both a researcher and a reader. Consistent following the trace left in culture by any selected motif makes it necessary to deal with both textual (recorded in writing) and visual cultural layers. And during this “following the motif” it frequently appears that we are moving along the arch of a hermeneutic (ph i lological) circle bent like reflection.Publikacja dofinansowana przez Fundację Uniwersytetu Łódzkiego oraz Katedrę Historii Sztuk