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EN
The paper presents a new method of quantitative parameterization of net geomorphological structures with the use of random walk formalism and an analysis of Hurst exponent distribution derived from random walk experiments. As examples, horizontally developed gypsum caves were elaborated. The provided methodology is able to uniquely characterize cave systems.
PL
Przebadano model wielostanowej komórki pamięci magnetycznej. Przeprowadzono analizę ilości stanów stabilnych, wyznaczono natężenie sygnału przełączającego (pole Zeemana) pomiędzy stanami w zależności od czasu przełączania oraz wyznaczono gęstość zapisu. 3-bitowa (o 8 niezależnych stanach stabilnych) komórka pamięci magnetycznej posiadała około 100 razy większą gęstość zapisu niż aktualnie spotykane pamięci SSD o najwyższej gęstości. Badane czasy przełączania były od 1000 do 100 tys. razy mniejsze niż we współczesnych półprzewodnikowych odpowiednikach. Ważną zaletą wyznaczonego nieukierunkowanego pola przełączającego była jego jednorodność w przestrzeni oraz jedynie zmiana w czasie.
EN
The model of multi-level magnetic cell memory was examined. The analysis of stable states, a switching signal (Zeeman field) intensity and direction in dependence of switching time along with writing density were performed. The 3-bit (8 independent stable states) magnetic cell memory achieved potential writing density of about 100-times higher then actual SSD memories having actually highest writing density. The examined switching times were from 1000 to 100000 times shorter then up to date semiconductor solutions. Importantly, the advantage of discovered switching field intensity was homogeneous in space and changed in time.
EN
The paper presents a new method of quantitative parameterization of volumetric-net geomorphological structures with the use of random walk formalism and an analysis of self-similarity exponent distribution derived from random walk experiments. As examples, two American three-dimensional Wind and Lechuguilla cave networks were elaborated. The provided methodology is able to uniquely characterize the morphology of cave systems.
EN
Gypsum labyrinthine caves are characterized by a complex spatial structure, which can be treated as fractals and can be studied using appropriate mathematical tools. Capacitance and correlation fractal dimensions of largest gypsum caves of the Western Ukraine (as well as the World’s largest ones) were calculated. The results were used to predict findings of new, undiscovered cave mazes parts.
5
Content available remote Supervised and unsupervised segmentation of multispectral retina images
EN
The segmentation method of multispectral human eye images suitable in ophthalmic diagnosis of structural retinal features characteristic for glaucoma and diabetic retinopathy diseases is presented. A multispectral imaging was realized in 21 spectral windows, between 400nm and 740nm, on a base of liquid crystal tunable filter and a high sensitivity monochrome camera. Results of supervised and unsupervised segmentation procedures of retina images, adopted from a color fundus device, are presented.
PL
W pracy zaprezentowano metodę segmentacji wielospektralnych obrazów dna oka ukierunkowaną na diagnostykę schorzeń jaskry i retinopatii cukrzycowej. Akwizycja wielospektralna prowadzona jest w 21 oknach widma z zakresu 400nm do 740nm na bazie elektronicznie sterowalnego filtra ciekłokrystalicznego i wysokiej czułości monochromatycznej kamery CCD. Przedstawiono uzyskane wyniki segmentacji w podejściu nadzorowanym i nienadzorowanym (Nadzorowana i nienadzorowana segmentacja wielospektralnych obrazów dna oka).
6
Content available remote A computer-based imaging system for multispectral inspection of skin cancer
EN
Multi-band imaging computer-based system, self-designed and self-constructed, based on a liquid-crystal filter with spectral transmittance driven in 400 nm - 740 nm wavelengths range is presented. Performed tests of images dimensionality reduction, which base on different types of principal component analysis, indicated onto flexibility and usefulness of the described approach for skin cancer diagnosis.
PL
W artykule opisano samodzielnie zaprojektowany i wykonany, wspomagany komputerowo, oparty na transmisyjnym filtrze ciekłokrystalicznym pracującym w zakresie długości fal od 400 nm do 740 nm, układ do obrazowania wielospektralnego. Przeprowadzone testy redukcji wymiarowości obrazu, w oparciu o różne rodzaje analizy jego składowych głównych, wskazały na użyteczność zastosowanego podejścia w diagnostyce raka skóry. (Komputerowy system wielospektralnej analizy danych obrazowych raka skóry).
PL
Przedstawiono koncepcję magnetooptycznego procesora hybrydowego z ferromagnetycznym rdzeniem przetwarzającym opartym o elementarne operacje logiczne.
EN
The paper presents an idea of magnetooptic hybrid processor with ferromagnetic processing core, based on elementary logic operations.
8
Content available remote Ophthalmic diagnosis based on multispectral imaging
EN
We have proposed and deployed prototyped multispectral capturing device for the ophthalmic diagnosis. The main component of the device are slit lamp, liquid crystal tunable filter and high sensitive monochrome camera. The applied hardware allows to obtain 21 spectral channels in the visible light range. The device has been calibrated based on the captured images of the colorchecker colors with known RGB and spectral values. The proposed device is focused on the diagnoses of cancer, PEX, galucoma and diabetic retinopathy.
PL
W ramach pracy zaproponowano urządzenie obrazowania wielospektralnego na potrzeby diagnostyki okulistycznej. Główne komponenty urządzenia to lampa szczelinowa, elektrycznie przełączalny filtr ciekłokrystaliczny oraz wysokiej czułości kamera monochromatyczna. Wybrane rozwiązania sprzętowe pozwalają na uzyskanie 21 kanałów spektralnym w zakresie światła widzialnego. Urządzenie zostało skalibrowane na podstawie zdjęć próbnika kolorów. Przewiduje się zastosowania opracowanego urządzenia w diagnostyce zmian nowotworowych, zespołu PEX, jaskry i retinopatii cukrzycowej.
9
Content available remote Isotropic effects in exchange-biased ferromagnetic /antiferromagnetic bilayers
EN
Novel, direction-independent (rotatable) spin-wave frequency modifications in a ferromagnetic layer biased by an antiferromagnetic film, revealed recently with Brillouin light scattering, have been analyzed. Physical conditions needed for the rotatable behaviour observations in epitaxial layers have been presented. The omni-rotatable down-shift, being a function of a spin-wave frequency, was distinguished from the up-shift of spin-wave frequencies induced by the exchange-bias. Additionally, the rotatable anisotropy constant was estimated from the available BLS results.
EN
The magnetocrystalline and magnetoelastic anisotropies of epitaxial CoO/Co(hcp) bilayers with dominating (100) crystallographic in-plane orientation have been investigated by means of light scattering from spin waves. Analysis of spin-wave frequencies measured in different sample orientations enabled distinction of several anisotropy contribution to the sample energy density. The role of a demagnetizing factor, possible out-of-plane anisotropies and their influence on the in-plane anisotropies, including the magnetoelastic contribution, were discussed.
EN
The aim of this article is to present a phenomenon of acoustic waves propagation in a single layer on a semi-infinite substrate from the classical theory of elasticity point of view, and recall the description of this phenomenon by G. W. Farnell and E. L. Adler issued in 1972. Additionally, the purpose is to provide tutorial-type, step-by-step scheme for the numerical algorithm, using matrix formalism, in order to calculate frequencies, velocities and polarizations of different acoustic modes propagating within a layer. It was shown how from these calculations elastic constants of materials can be derived from fittings into dependencies between velocities and acoustic wave-vectors. The approach presented is related to Brillouin light scattering (BLS) experiments. The BLS experiments provide information about acoustic modes frequencies, velocities and wave-vectors, thus supporting the fitting procedure by reduction number of the unknown parameters.
EN
This paper provides the results of exchange-bias simulation of a single ferromagnetic (FM) layer coupled to a quenched antiferromagnetic (AFM) region using a Random Field Ising Model (RFIM) approach. Using the RFIM algorithm the shapes of exchange-biased hysteresis loops, featuring perpendicular magnetic anisotropies, were obtained. Providing a possible explanation of this effect the recognized stable part of an interface magnetisation represented by unreversed spins at the interface was evidently simulated. Obtained results are consistent with the Domain State Model (DSM) model, where a part of the AFM interface magnetisation is stable during hysteresis loop creation
EN
What is presented here are the preliminary results of exchange-bias simulation of a single ferromagnetic layer (FM) coupled to an antiferromagnetic (AFM) region with a diluted lattice using a Random Field Ising Model approach. Dilution is simulated by locally enhancement of ferromagnetic coupling constants calculated at random positions with a given dilution level. The results show a direct correlation between exchange-bias and a number of unreversed spins at the FM/AFM interface. Within a dilution level, two components were identified; a global random dilution and a local dilution efficiency. The latter is represented by the coupling constant enhancement. Interpretation of this interfacial effect
EN
The paper examines theoretically changes in the speed of an acoustic wave in crystals caused by metallic dopants. It is well known that an acoustic wave has a wavelength larger than the typical dimension of the elementary crystallographic cell, so it is sensitive only to large-scale features. The model bases on the assumption that a crystal with uniform distributed dopants can be transformed into a multiplayer virtual structure form which some conclusions can be drawn. The approach presented is valid for longitudinal acoustic waves, where the atomic displacement can be considered as a continuum field. It provides positive or negative changes in the acoustic wave speeds for different dopants in a hypothetical lithium niobate crystal.
PL
Monografia opisuje rezultaty badań podstawowych oraz dostarcza szeregu praktycznych informacji dotyczących eksperymentów wykorzystujących brillouinowskie rozpraszanie światła. Istotną właściwością książki jest to, że łączy w jedną całość opis fal akustycznych i spinowych o częstotliwościach gigahercowych. Ideą, która unifikuje ten tak bardzo szeroki zakres zjawisk, jest kierunkowy charakter spektroskopii brillouinowskiej oraz jej charakter lokalny. Praca w końcowej części relacjonuje wyniki badań nad anizotropami posiadającymi naturę magnetyczną, w supersieciach metalicznych, oraz dwuwarstwowymi strukturami podlegającymi efektowi "exchange-bias". Struktury i własności te będą miały w niedalekiej przyszłości kluczowe znaczenia dla zaawansowanych technologii elektronicznych. W supersieci Co/Cu zaobserwowano mody Damona-Eshbacha (D-E) - mody propagujące się powierzchniowo po wszystkich bokach próbki. Zaobserwowano charakterystyczne rozszczepienie modów D-E od fal objętościowych wynikających z oddziaływań dipolowych pomiędzy warstwami magnetycznymi rozdzielonymi warstwą niemagnetyczną. W strukturach Co/CoO zaobserwowano fale spinowe skwantowane w kierunku prostopadłym do warstw. Książka uzupełnia jednocześnie szeroko udokumentowane rezultaty badań rozpraszania w próbkach objętościowych. W szczególności informuje o odkrytym zjawisku przełączania kanału rozpraszania oraz donosi o nietypowym tle w widmie brillouinowskim zaobserwowanym w krysztale tlenkowym SLAO.
EN
This book reports basic-type research and provides some practical information about Brillouin light scattering experiments. What the book weaves together includes: elastic and magnetic GHz elastic waves with spin waves. The idea which unites this wide range of results is the unidirectionality of Brillouin scattering and the local-probing character of the spectroscopy. The book concludes with results of in-plane anisotropies, magnetic in nature, in metallic superlattices and bilayered exchange-biased structures. These are features which will in the future be basic to new advanced technologies. Observed in the Co/Cu superlattices surface modes of the stack as a whole, the Damon-Eshbach (D-E) waves, coherent and sensitive to surface and subsurface magnetic features. The splitting of the D-E mode from the band of the dipolar-coupled wave was observed when the magnetic layer thickness was larger than the nonmagnetic one. In the Co/CoO bilayers, spin waves of quantized perpendicular wave-vector components were observed for chosen crystallographic directions. The book updates widely documented bulk crystal results thanks to the discovery of acoustic phonon branch switch and atypical background in oxide-type crystals.
16
Content available remote Inexpensive linear scanning of the Fabry-Perot interferometer
EN
The solution presented here can be useful in optical measurements where scanning in the Fabry-Perot interferometer spectral range is needed. The key to the idea is the use of a pressure sensor equipped with stainless steel diaphragm giving voltage signal proportional to pressure in a chamber where the Fabry-Perot etalon is mounted. The method should find new fields of application, in a simple and cost effective way, in university laboratories as well as in other research institutions. The previous solution is updated here by introducing silicon membrane pressure sensor.
EN
Influence of doping effect of Cu ions on the elastic prperties of the LiNbO3 crystal in were studied by the Brilloui light scattering method. Dopant concentration of Cu was equal to 0.05mol%. Comparison with pure samples shower relative decrease in frequencies falling in the range od 4-11%. Measurements were done in defferent scattering configurations.
20
Content available remote A typical Brillouin light-scattering spectrum in the SrLaAlO4 (SLAO) crystal
EN
A new wide-band frequency component in the Brillouin spectrum, arising from absorption, has been detected in the SLAO oxide crystal. This completes the typical Brillouin spectrum, where Rayleigh lines, inelastic Stokes and anti-Stokes lines have been observed as a result of scattering from bulk acoustic phonons and, for some experimental configurations, on surface acoustic phonons. This newly discovered spectral component is distributed uniformly in frequency, independently of the light power incident on a sample, and depends on the incident wavelength.
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