Informacja

Drogi użytkowniku, aplikacja do prawidłowego działania wymaga obsługi JavaScript. Proszę włącz obsługę JavaScript w Twojej przeglądarce.

Wyszukujesz frazę "Kim, M. N." wg kryterium: Autor


Wyświetlanie 1-15 z 15
Tytuł:
A New 3D Sensor System by Using Virtual Camera Model and Stereo Vision for Mobile Robots
Autorzy:
Lee, H.
Kim, M. N.
Cho, H.
Powiązania:
https://bibliotekanauki.pl/articles/384962.pdf
Data publikacji:
2008
Wydawca:
Sieć Badawcza Łukasiewicz - Przemysłowy Instytut Automatyki i Pomiarów
Tematy:
virtual camera model
stereo vision
Opis:
So many researches have been conducted to develop 3D sensing method for mobile robots. Among them, the optical triangulation, a well-known method for 3D shape measurement, is also based on active vision sensing principle for mobile robot sensor system, so that the measurement result is robust to illumination noises from environments. Due to this advantage it has been popularly used. However, to obtain the 3D information of environment needs a special scanning process and scanning actuators need. To omit this scanning process multi-line projection methods have been widely researched. However, they suffer from an inherent limitation: The results of multi-line projection method commonly have measurement errors because of 2 -ambiguity caused by regularly repeated multiline laser pattern. In this paper, to overcome 2 -ambiguity effectively, we introduce a novel sensing method for a 3D sensing system using multi-line projection and stereo cameras, based on the virtual camera model and stereovision algorithm. To verify the efficiency and accuracy of the proposed method, a series of experimental tests is performed.
Źródło:
Journal of Automation Mobile Robotics and Intelligent Systems; 2008, 2, 4; 38-44
1897-8649
2080-2145
Pojawia się w:
Journal of Automation Mobile Robotics and Intelligent Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The Effects of Experience and the Presence of a Scaffold Handrail on Postural and Spinal Stability in Construction Workers
Autorzy:
Min, S. N.
Kim, J. Y.
Parnianpour, M.
Powiązania:
https://bibliotekanauki.pl/articles/91154.pdf
Data publikacji:
2014
Wydawca:
Centralny Instytut Ochrony Pracy
Tematy:
fall
low back pain
postural stability
lumbar stability
construction
injury
ból pleców
stabilność postawy
pracownicy budowlani
rusztowanie budowlane
Opis:
The goal of this study was to quantify the effect of experience and handrail presence on trunk muscle activities, rotational spinal stiffness and postural stability of construction workers. We evaluated spinal stability, and objective and subjective postural stability in 4 expert and 4 novice construction workers who were performing a manual task in a standing position on a scaffold, with and without a safety handrail. Center of pressure was computed using measurements taken with insole pressure transducers. Muscle activity was monitored usingsurface electrodes placed on 8 trunk muscles that predicted active trunk rotational stiffness. Standard deviations of the center of pressure, back muscle activity and spinal stiffness were greater in novices and in the absence of a handrail. We infer that the risk of a fall due to postural and spinal instability may be greater with a lower level of experience and in the absence of a safety handrail.
Źródło:
International Journal of Occupational Safety and Ergonomics; 2014, 20, 3; 491-502
1080-3548
Pojawia się w:
International Journal of Occupational Safety and Ergonomics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Scanning Tunneling Spectra and Low Energy Ion Scattering Studies of the Verwey Transition in MBE Fe$\text{}_{3}$O$\text{}_{4}$ (100) Thin Film
Autorzy:
Kim-Ngan, N.-T. H.
Soszka, W.
Hietschold, M.
Powiązania:
https://bibliotekanauki.pl/articles/2024029.pdf
Data publikacji:
2001-02
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
61.16.Ch
61.18.Bn
71.30.+h
Opis:
The (100) surface of magnetite Fe$\text{}_{3}$O$\text{}_{4}$ thin film was studied by a UHV low-temperature scanning tunneling microscope and by an ion scattering spectroscopy. The tunneling spectra revealed a widening of the gap with decreasing temperature, which may be related to the metal-insulator phase transition in this material. A strong effect of this phase transition on ion scattering from such a surface was observed. The temperature dependence of the scattered ion yield, R$\text{}^{+}$(T), revealed two minima at around 100 K and at 125 K under Ne$\text{}^{+}$ bombardment with the primary energy up to 6 keV. The disappearance of the high-temperature minimum at a bombarding energy of 6.5 keV gave a further evidence for the ion velocity dependence of the character of the R$\text{}^{+}$(T) curve, which has been first observed for a MBE Fe$\text{}_{3}$O$\text{}_{4}$ (111) film surface.
Źródło:
Acta Physica Polonica A; 2001, 99, 2; 267-276
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A mixed control chart adapted to the truncated life test based on the Weibull distribution
Autorzy:
Khan, N.
Aslam, M.
Kim, K.-J.
Jun, C. -H.
Powiązania:
https://bibliotekanauki.pl/articles/406432.pdf
Data publikacji:
2017
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
life test
Weibull distribution
attribute chart
binomial distribution
average run length
Opis:
The design of a new mixed attribute control chart adapted to a truncated life test has been pre-sented. It was assumed that the lifetime of a product follows the Weibull distribution and the number of failures was observed using a truncated life test, where the test duration was specified as a fraction of the mean lifespan. The proposed control chart consists of two pairs of control limits based on a binomial distribution and one lower bound. The average run length of the chart was determined for various levels of shift constants and specified parameters. The efficiency of the chart is compared with an existing control chart in terms of the average run length. The application of the proposed chart is discussed with the aid of a simulation study.
Źródło:
Operations Research and Decisions; 2017, 27, 1; 43-55
2081-8858
2391-6060
Pojawia się w:
Operations Research and Decisions
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Superconductivity in U-T Alloys (T = Mo, Pt, Nb, Zr) Stabilized in the Cubic γ-U Structure
Autorzy:
Sowa, S.
Kim-Ngan, N.
Krupska, M.
Paukov, M.
Tkach, I.
Havela, L.
Powiązania:
https://bibliotekanauki.pl/articles/1398594.pdf
Data publikacji:
2016-08
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
81.05.Bx
74.70.Ad
72.15.Cz
Opis:
Using ultrafast cooling (with the cooling rate up to 10⁶ K/s) helps to minimize the T-alloying concentration (T = Mo, Pt, Pd, Nb, Zr) necessary to retain the γ-U phase down to low temperatures. All investigated splat-cooled U-T alloys become superconducting with $T_{c}$ in the range of 0.61-2.11 K. The bulk character of superconductivity can be concluded for some of the splats when comparing the specific-heat anomaly at $T_{c}$ with the BCS theory prediction.
Źródło:
Acta Physica Polonica A; 2016, 130, 2; 521-526
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Interface Properties of Single and Bi-Layer $Fe_3O_4$ Films Grown on MgO(001) Studied by RBS and Channeling Experiments
Autorzy:
Kim-Ngan, N.
Balogh, A.
Brötz, J.
Zając, M.
Korecki, J.
Powiązania:
https://bibliotekanauki.pl/articles/1535628.pdf
Data publikacji:
2010-10
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
34.35.+a
68.35.Ct
68.35.Fx
68.47.Gh
Opis:
Series of $Fe_3O_4$/MgO(001) and $Fe_3O_4$/Fe/MgO(001) films (single- and bi-layer films, respectively) with a total layer thickness in the range of 20 ÷ 150 nm were investigated by the Rutherford backscattering spectrometry (2 MeV $He^{+}$ ion beam), by the Rutherford backscattering spectrometry channeling experiments (1.5 MeV $He^{+}$ ion beam). Depending on the layer thickness of each layer and the film geometry, a single Fe peak and/or a double-anomaly feature was revealed in the Rutherford backscattering spectra. For all films no magnesium presence in the surface layer was observed. For both single- and bi-layer films with a total layer thickness less than 60 nm only one minimum was observed in the channeling curves, while a double minimum was revealed for the bi-layer films with a larger thickness. X-ray reflectometry measurements have revealed that the film density is the same as that of the bulk one.
Źródło:
Acta Physica Polonica A; 2010, 118, 4; 570-575
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Microstructure Development of Spark Plasma Sintered Ti-Nb Alloy by Heat Treatment
Autorzy:
Haq, M. A.
Abbas, S. F.
Eom, N. S. A.
Kim, T. S.
Lee, B.
Park, K.-T.
Kim, B. S.
Powiązania:
https://bibliotekanauki.pl/articles/355593.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
TiNb alloy
Spark plasma sintering
Heat treatment
Microstructure
β-phase titanium
Opis:
The β-phase Titanium (β-Ti) alloys have been under the spotlight in the recent past for their use as biomedical prosthetic materials owing to their excellent properties such as low elastic modulus, high corrosion resistance and tensile strength. Recently, Niobium (Nb) has gained a lot of attention as a β-phase stabilizing element in Ti alloys to replace Vanadium (V) due to its excellent solubility in Ti, low elastic modulus and biocompatibility. In this work, low cost Ti-20Nb binary alloy has been fabricated via powder metallurgy procedures. The blended powder mixtures of Ti and Nb were sintered at 900°C for 20 mins by the Spark Plasma Sintering (SPS) with an applied uniaxial pressure of 40 MPa. The heating rate was fixed at 50°C/min. The sintered alloy was subject to heat treatments at 1200°C in vacuum condition for various time durations. The characterizations of microstructure obtained during this process were done using FE-SEM, EDS and XRD. By increasing heat treatment time, as understood, the volume of residual Nb particles was decreased resulting in accelerated diffusion of Nb into Ti. Micro hardness of the alloy increased from 340 to 355 HV with the increase in β phase content from 30 to 45%. The resultant alloys had relatively high densities and homogenized microstructures of dispersed lamellar β grains in α matrix.
Źródło:
Archives of Metallurgy and Materials; 2018, 63, 3; 1429-1432
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The Development of Ship Watch Keeping Supporting Aids
Autorzy:
Im, N.
Kim, E. K.
Han, S. H.
Jeong, J. S.
Lee, S. M.
Powiązania:
https://bibliotekanauki.pl/articles/117602.pdf
Data publikacji:
2013
Wydawca:
Uniwersytet Morski w Gdyni. Wydział Nawigacyjny
Tematy:
Ship Watchkeeping
Deck Officers
Navigation Visual Supporting System
Intelligent Technology
Dangerous Floating Objects
Binocular Telescope
laser distance measuring unit
Sea Trial Test
Opis:
This study deals with the development of ship watch keeping supporting aids that will be useful for ship deck officers in recognizing navigational harmful obstacles such as sea marks and small floating objects on the sea. The developed watch keeping supporting aids is made up of four components; a composite video sensor to produce video signal, a laser distance measuring part, a Pan/Tilt part and a central control part. The system was installed in a ship in order to verify its performance of the recognition ability on the sea. The comparison was made between the recognition ability of the system and that of watch keeping deck officers’. The image from the watch keeping supporting system was found to be more recognizable than that of a binocular telescope within a 5 km distance. The newly suggested system is expected to be used to recognize small dangerous floating objects more easily when navigation deck officers have a duty of watch keeping for navigation especially near harbor area.
Źródło:
TransNav : International Journal on Marine Navigation and Safety of Sea Transportation; 2013, 7, 4; 501-506
2083-6473
2083-6481
Pojawia się w:
TransNav : International Journal on Marine Navigation and Safety of Sea Transportation
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The vortex activation method of reagent water treatment
Autorzy:
Laguntsov, N.
Kim, V.
Krasnov, P.
Neshchimenko, Y.
Borisenko, M.
Odintsov, A.
Fartunin, A.
Powiązania:
https://bibliotekanauki.pl/articles/346919.pdf
Data publikacji:
2006
Wydawca:
Politechnika Bydgoska im. Jana i Jędrzeja Śniadeckich. Wydział Technologii i Inżynierii Chemicznej
Tematy:
coagulation
flocculation
water purification
oil products
suspension particles
Opis:
The experimental study on vortex activation method of reagent water purification from oil products and suspension particles using the alumosilicon flocculant-coagulant (ASFC) was made. The numerical model of water purification was suggested according to Smoluhovsky theory of coagulation kinetics.
Źródło:
Ars Separatoria Acta; 2006, 4; 57-66
1731-6340
Pojawia się w:
Ars Separatoria Acta
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Specific Heat of RBa$\text{}_{2}$Cu$\text{}_{3}$O$\text{}_{7-x}$ and RBaSrCu$\text{}_{3}$O$\text{}_{7-x}$ Compounds (R = Sm, Dy, Er)
Autorzy:
Tarnawski, Z.
Kim-Ngan, N.-T. H.
Wang, X. Z.
Duijn, V. H. M.
Franse, J. J. M.
Powiązania:
https://bibliotekanauki.pl/articles/1968860.pdf
Data publikacji:
1998-03
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
74.70.-b
75.40.-s
Opis:
The low-temperature specific-heat C(T) data of high-T$\text{}_{c}$ superconductors RBa$\text{}_{2}$Cu$\text{}_{3}$O$\text{}_{7-x}$(R123O$\text{}_{7-x}$) were reviewed. A discussion of the C(T) data obtained on single-crystalline samples of Er123O$\text{}_{7-x}$ and Sm123O$\text{}_{7-x}$ compounds in applied magnetic fields for better evaluation of the crystal-electric-field parameters is given. The C(T) measurements of Sr-substituted compounds RBaSrCu$\text{}_{3}$O$\text{}_{7}$ revealed the λ-type of peak related to the antiferromagnetic order at 1.2 K and 0.6 K respectively for Dy- and Er-compounds. The magnetic singlet ground state in these compounds is produced by weak exchange interactions of -0.05 T/μ$\text{}_{B}$ and -0.035 T/μ$\text{}_{B}$, respectively. For Nd- and Sm-compounds, only a broad anomaly around 0.6 K was observed which is well fitted with a Schottky-type anomaly with an energy splitting of 1.4 K.
Źródło:
Acta Physica Polonica A; 1998, 93, 3; 513-522
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Oligonol prevented the relapse of dextran sulfate sodium-ulcerative colitis through enhancing Nrf2-mediated antioxidative defense mechanism
Autorzy:
Kim, K.-J.
Park, J.-M.
Lee, J.-S.
Kim, Y.S.
Kangwan, N.
Han, Y.-M.
Kang, E.A.
An, J.M.
Park, Y.K.
Hahm, K.-B.
Powiązania:
https://bibliotekanauki.pl/articles/69501.pdf
Data publikacji:
2018
Wydawca:
Polskie Towarzystwo Fizjologiczne
Tematy:
ulcerative colitis
inflammatory bowel disease
oxidative stress
oligonol
polyphenol
adaptive response
quinone oxidoreductase
relapse
nuclear factor-kappaB
tumour necrosis factor-alpha
Źródło:
Journal of Physiology and Pharmacology; 2018, 69, 3
0867-5910
Pojawia się w:
Journal of Physiology and Pharmacology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Electronic States of $UNi_2$ from Photoemission Spectroscopy
Autorzy:
Zalecki, R.
Kołodziejczyk, A.
Kim-Ngan, N.
Adamska, A.
Kowalczyk, A.
Toliński, T.
Mihalik, M.
Powiązania:
https://bibliotekanauki.pl/articles/1813761.pdf
Data publikacji:
2008-01
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
71.20.Lp
79.60.Bm
71.15.Ap
Opis:
We measured the angle-resolved ultraviolet and X-ray photoemission spectra of $UNi_2$ single crystal. The valence band angle-resolved ultraviolet photoemission spectra were compared to the accessible band structure calculations. For $UNi_2$ the lowest binding energy strong emission at about -0.1 eV comes from U 5f states and overlaps with the Fermi edge. A small feature at -0.6 eV was ascribed also to U 5f electrons with more localised character. The higher-energy two-peak structure at about -1.2 eV and -2.1 eV comes from Ni 3d states. X-ray photoemission spectroscopy shows the standard two-line spin-orbit splitting of the Ni 2p states and of the U 4f states. Some hybridisation of the Ni 3d and U 5f state was observed in the spectra. The pronounced satellites to the Ni 2p and 3p states, associated with the on-site Coulomb repulsion and other electron correlation energies, were observed.
Źródło:
Acta Physica Polonica A; 2008, 113, 1; 407-412
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Study of Ti, V and Their Oxides-Based Thin Films in the Search for Hydrogen Storage Materials
Autorzy:
Tarnawski, Z.
Zakrzewska, K.
Kim-Ngan, N.-T.
Krupska, M.
Sowa, S.
Drogowska, K.
Havela, L.
Balogh, A.
Powiązania:
https://bibliotekanauki.pl/articles/1401913.pdf
Data publikacji:
2015-09
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
81.15.Cd
68.49.-h
61.05.C-
68.60.-p
Opis:
Thin film series consisting of Ti, V, TiO₂ and V₂O₅ layer with different layer geometries, sequences and thicknesses have been prepared by the sputtering technique. The hydrogen depth profile of selected films upon hydrogen charging at 1 bar and/or hydrogenation at pressure up to 102 bar was determined by using secondary ion mass spectrometry and nuclear reaction analysis using a N-15 beam. The highest hydrogen storage with a concentration up to 50 at.% was found in the pure Ti and Ti-contained layer, while it amounts to around 30% in the metallic Ti-V-Ni layer. Hydrogen can diffuse through the TiO₂ layer without accumulation, but can be stored in the VO₂ layer in some cases. Hydrogen can remove the preferential Ti orientation in the films and induce a complete transition of V₂O₅ into VO₂ in the films.
Źródło:
Acta Physica Polonica A; 2015, 128, 3; 431-439
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Low-velocity impact characteristics of composite plates with shape memory alloy wires
Niskoprędkościowe charakterystyki uderzeniowe płyt kompozytowych zawierających włókna ze stopów z pamięcią kształtu
Autorzy:
Rim, M.-S.
Kim, E.-H.
Lee, I.
Choi, I.-H.
Ahn, S.-M.
Koo, K.-N.
Bae, J.-S.
Roh, J.-H.
Powiązania:
https://bibliotekanauki.pl/articles/279293.pdf
Data publikacji:
2011
Wydawca:
Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
Tematy:
shape memory alloy
SMAHC
composite
low-velocity impact
impact resistance
Opis:
To investigate impact characteristics of shape memory alloy hybrid com- posites (SMAHC), several experiments were performed. Tensile tests of shape memory alloy (SMA) wires were carried out to investigate thermomechanical properties, and low-velocity impact tests of SMAHC plates and conventional composite plates without SMAs at the critical energy level. low-velocity impact tests of several types of composite plates, including composite plates with embedded SMAs/Fe/Al wires and conventional composite plates, were also done. Results of these experiments show that embedding SMAs in a composite plate can improve the impact resistance. Lastly, low-velocity impact tests of SMAHC plates with SMA wires embedded at different positions through the thickness were performed in an effort to improve the impact resistance. Embedding SMA wires at a lower position in the composite plates was the most effective for improving the impact resistance.
Do analizy charakterystyk uderzeniowych hybrydowych kompozytów SMAHC zwierających włókna SMA ze stopów wykazujących efekt pamięci kształtu przeprowadzono szereg badań eksperymentalnych. Przeprowadzono próby na rozciąganie włókien SMA w celu zbadania ich właściwości termomechanicznych oraz niskoprędkościowe testy uderzeniowe płyt SMAHC oraz konwencjonalnych płyt laminowanych przy energii krytycznej. Wykonano także testy dla płyt kompozytowych zawierających włókna SMA/Fe/Al. Rezultaty doświadczeń pokazały, że wbudowanie w strukturę laminatu włókien SMA może zwiększyć odporność kompozytu na obciążenie uderzeniowe. Opisano również badania eksperymentalne płyt SMAHC z włóknami SMA wbudowanymi na różnej głębokości. Wykazano, że najlepsze parametry posiadają kompozyty z włóknami umieszczonymi możliwie daleko od uderzanej powierzchni.
Źródło:
Journal of Theoretical and Applied Mechanics; 2011, 49, 3; 841-857
1429-2955
Pojawia się w:
Journal of Theoretical and Applied Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Multistep Heat-Treatment Effects on Electrospun Nd-Fe-B-O Nanofibers
Autorzy:
Jeon, E. J.
Eom, N. S. A.
Lee, J.
Lee, B.
Cho, H. M.
On, J. S.
Choa, Y.-H
Kim, B. S.
Powiązania:
https://bibliotekanauki.pl/articles/354311.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
Nd-Fe-B
nanofibers
electrospinning
heat treatment
Opis:
Neodymium-Iron-Boron (Nd-Fe-B) magnets are considered to have the highest energy density, and their applications include electric motors, generators, hard disc drives, and MRI. It is well known that a fiber structure with a high aspect ratio and the large specific surface area has the potential to overcome the limitations, such as inhomogeneous structures and the difficulty in alignment of easy axis, associated with such magnets obtained by conventional methods. I n this work, a suitable heat-treatment procedure based on single-step and multistep treatments to synthesize sound electrospun Nd-Fe-B-O nanofibers of Φ572 nm was investigated. The single-step heat-treated (directly heat-treated at 800°C for 2 h in air) samples disintegrated along with the residual organic compounds, whereas the multistep heat-treated (sequential three-step heat-treated including three steps;: dehydration (250°C for 30 min in an inert atmosphere), debinding (650°C for 30 min in air), and calcination (800°C for 1 h in air)) fibers maintained sound fibrous morphology without any organic impurities. They could maintain such fibrous morphologies during the dehydration and debinding steps because of the relatively low internal pressures of water vapor and polymer, respectively. In addition, the NdFeO3 alloying phase was dominant in the multistep heat-treated fibers due to the removal of barriers to mass transfer in the interparticles.
Źródło:
Archives of Metallurgy and Materials; 2018, 63, 3; 1433-1437
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-15 z 15

    Ta witryna wykorzystuje pliki cookies do przechowywania informacji na Twoim komputerze. Pliki cookies stosujemy w celu świadczenia usług na najwyższym poziomie, w tym w sposób dostosowany do indywidualnych potrzeb. Korzystanie z witryny bez zmiany ustawień dotyczących cookies oznacza, że będą one zamieszczane w Twoim komputerze. W każdym momencie możesz dokonać zmiany ustawień dotyczących cookies