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Tytuł:
Variable structure observer design for a class of uncertain systems with a time-varying delay
Autorzy:
Liu W., J.
Powiązania:
https://bibliotekanauki.pl/articles/330119.pdf
Data publikacji:
2012
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
obserwator
niezmienniczość
uogólniona odwrotność macierzy
variable structure observer
invariance property
generalized matrix inverse approach
Opis:
Design of a state observer is an important issue in control systems and signal processing. It is well known that it is difficult to obtain the desired properties of state feedback control if some or all of the system states cannot be directly measured. Moreover, the existence of a lumped perturbation and/or a time delay usually reduces the system performance or even produces an instability in the closed-loop system. Therefore, in this paper, a new Variable Structure Observer (VSO) is proposed for a class of uncertain systems subjected to a time varying delay and a lumped perturbation. Based on the strictly positive real concept, the stability of the equivalent error system is verified. Based on the generalized matrix inverse approach, the global reaching condition of the sliding mode of the error system is guaranteed. Also, the proposed variable structure observer will be shown to possess the invariance property in relation to the lumped perturbation, as the traditional variable structure controller does. Furthermore, two illustrative examples with a series of computer simulation studies are given to demonstrate the effectiveness of the proposed design method.
Źródło:
International Journal of Applied Mathematics and Computer Science; 2012, 22, 3; 575-583
1641-876X
2083-8492
Pojawia się w:
International Journal of Applied Mathematics and Computer Science
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Building the B2B customer loyalty : a role of relationship quality
Budowanie lojalności klienta B2B : rola jakości relacji
Autorzy:
Liu, L.-W.
Yang, W.-G.
Liu, W.-H.
Powiązania:
https://bibliotekanauki.pl/articles/405772.pdf
Data publikacji:
2017
Wydawca:
Politechnika Częstochowska
Tematy:
information sharing
customer orientation
B2B relationship
PLS-SEM
relationship marketing
wymiana informacji
orientacja na klienta
relacje B2B
marketing relacji
Opis:
The purpose of this study was to investigate the E-Commerce relationship quality and loyalty in B2B supplier and client’s relationships. This study tries to conceptualize a model based on the relationship quality that is applied to understand loyalty in B2B environment. The subjects of this study, from whom 81 valid questionnaires were collected, were the clients of the supplier’s ERP system in the Taiwan. When descriptive statistics and partial least squares (PLS) were adopted to analyse the collected valid data, we obtained the following findings. Relationship quality was perceived through the behavior of both supplier and clients and the quality of their interaction. Relationship quality antecedents include the information sharing and customer orientation. The finding suggests that supplier with strong levels of customer orientation, the supplier and clients were built a stronger relationship and high loyalty. Surprisingly, information sharing shown no significant effects on the relationship quality. This study implies that using information sharing and customer orientation strengthen their relationship quality, thereby enhancing loyalty. The finding of this study implies that it is important for a B2B supplier management to understand clients’ needs and responses. B2B suppliers can learn from this study, that customer orientation, relationship quality, commitment, have a positive impact on loyalty in both direct and indirect ways.
Celem artykułu była analiza jakości relacji z klientami i lojalności w handlu elektronicznym u dostawcy B2B. Niniejsze badanie jest próbą konceptualizacji modelu opartego na jakości relacji, który jest próbą zrozumienia lojalności w środowisku B2B. Przedmiotem badania byli wybrani klienci systemu ERP w oparciu na zebranych 81 kwestionariuszach firm na Tajwanie. Przyjęto statystyki opisowe i w oparciu o metodę najmniejszych kwadratów (PLS) w celu przeanalizowania zebranych istotnych danych. Jakość relacji postrzegano poprzez zachowanie zarówno dostawcy, jak i klientów oraz jakość ich interakcji. Jakość relacji przede wszystkim obejmuje dzielenie się informacjami i orientację na klienta. Wyniki sugerują, że dostawcy z silnym poziomem orientacji na klienta, zbudowali silniejszą więź i wysoką lojalność relacji z dostawcami i klientami. Co zaskakujące, wymiana informacji nie wykazała znaczącego wpływu na jakość relacji. Badanie zakłada, że korzystanie z wymiany informacji i orientacja na klienta wzmacnia ich jakość relacji, zwiększając przez to lojalność. Odkrycie tego badania implikuje, że dla dostawcy usług B2B ważne jest zrozumienie potrzeb i odpowiedzi klientów. Dostawcy B2B winni zauważyć, że orientacja na klienta, jakość relacji, zaangażowanie, mają pozytywny wpływ na lojalność zarówno w sposób bezpośredni, jak i pośredni.
Źródło:
Polish Journal of Management Studies; 2017, 16, 1; 105-114
2081-7452
Pojawia się w:
Polish Journal of Management Studies
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Robotic rehabilitation of stroke patients using an expert system
Autorzy:
Natarajan, P.
Agah, A.
Liu, W.
Powiązania:
https://bibliotekanauki.pl/articles/384968.pdf
Data publikacji:
2011
Wydawca:
Sieć Badawcza Łukasiewicz - Przemysłowy Instytut Automatyki i Pomiarów
Tematy:
rehabilitation robots
intelligent systems
human-robot interaction
expert systems
stroke therapy
Opis:
Approximately 50 to 60 percent of the more than five million stroke survivors are moderately or minimally impaired, and may greatly benefit from rehabilitation. There is a strong need for cost-effective, long-term rehabilitation solutions, which require the therapists to provide repetitive movements to the affected limb. This is a suitable task for specialized robotic devices; however, with the few commercially available robots, the therapists are required to spend a considerable amount of time programming the robot, monitoring the patients, analyzing the data from the robot, and assessing the progress of the patients. This paper focuses on the design, development, and clinically testing an expert systembased post-stroke robotic rehabilitation system for hemiparetic arm. The results suggest that it is not necessary for a therapist to continuously monitor a stroke patient during robotic training. Given the proper intelligent tools for a rehabilitation robot, cost-effective long-term therapy can be delivered with minimal supervision.
Źródło:
Journal of Automation Mobile Robotics and Intelligent Systems; 2011, 5, 1; 47-57
1897-8649
2080-2145
Pojawia się w:
Journal of Automation Mobile Robotics and Intelligent Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Szybki wzrost kryształów jako metoda postępowania z odpadowym Mg(OH)2
Rapid growth approaches from nano-Mg(OH)2 to bulk materials and their application in the environment
Autorzy:
Liu, W.
Huang, F.
Lin, Z.
Powiązania:
https://bibliotekanauki.pl/articles/1218409.pdf
Data publikacji:
2012
Wydawca:
Stowarzyszenie Inżynierów i Techników Przemysłu Chemicznego. Zakład Wydawniczy CHEMPRESS-SITPChem
Tematy:
metale ciężkie
nanosorbenty
regeneracja
zatężanie
ścieki rozcieńczone
heavy metal
nono-adsorbents
regeneration
preconcentrate
dilute wastewater
Opis:
Istnieje duże zapotrzebowanie na badania nad detoksykacją nanoodpadów i recyklingiem zużytych nanosorbentów. W niniejszym artykule dokonano przeglądu badań prowadzonych w tej dziedzinie przez naszą grupę. Przetwarzanie nano-Mg(OH)2 z ładunkiem Cr(VI) stanowi nową strategię zagospodarowania nanoodpadów. Nanoodpady zostały przetworzone w nietoksyczny materiał masowy i stężony roztwór zawierający Cr(VI) na drodze szybkiego wzrostu nanokryształów, który spowodował desorpcję i całkowite oddzielenie Cr(VI) od substancji stałej. Stężony roztwór Cr(VI) można poddać recyklingowi przemysłowemu, a oczyszczony produkt stały można stosować w produkcji materiałów ceramicznych, powłok do metali i ognioodpornych tworzyw sztucznych. Przedstawiono też strategię recyklingu nanosorbentu Mg(OH)2 do stosowania go do usuwania Cr(VI) z roztworów o małym stężeniu Cr(VI).
There is a strong demand for the investigations on the detoxification of the nano-wastes or recycling of the loaded nanoadsorbents. This article reviews the studies of our group in this field. The treatment of Cr(VI) loaded nano-Mg(OH)2 introduces a new strategy for nano-waste disposal. The nano-wastes were converted into a nontoxic bulk material and a concentrated solution containing Cr(VI) by the rapid growth of nano-cystals which leads to the desorption and complete separation of Cr(VI) from the solid. The concentrated Cr(VI) solution can be recycled in the industry and the detoxified solid product can be reutilized in ceramics, metal coatings or flame-retardant plastics. Finally, a recycling strategy of Mg(OH)2 nano-adsorbent was provided for the enrichment of Cr(VI) from aqueous solutions of low-concentration Cr(VI).
Źródło:
Chemik; 2012, 66, 9; 919-928
0009-2886
Pojawia się w:
Chemik
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Stope stability assessment and effect of horizontal to vertical stress ratio on the yielding and relaxation zones around underground open stopes using empirical and finite element methods
Ocena stabilności przodka wybierkowego i wpływ relacji naprężeń poziomych do pionowych na strefy osiadania i odprężenia w okolicy przodka prowadzonego bez obudowy w kopalniach podziemnych przy zastosowaniu metody empirycznej oraz metody elementów skończonych
Autorzy:
Sepehri, M.
Apel, D.
Liu, W.
Powiązania:
https://bibliotekanauki.pl/articles/219566.pdf
Data publikacji:
2017
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
stability graph
open stope design
numerical modeling
rock mechanics
relaxation zone
underground mining
wykres stabilności
projektowanie przodka wybierkowego
modelowanie numeryczne
mechanika skał
strefa odprężona
górnictwo podziemne
Opis:
Predicting the stability of open stopes can be a challenging task for underground mine engineers. For decades, the stability graph method has been used as the first step of open stope design around the world. However, there are some shortcomings with this method. For instance, the stability graph method does not account for the relaxation zones around the stopes. Another limitation of the stability graph is that this method cannot to be used to evaluate the stability of the stopes with high walls made of backfill materials. However, there are several analytical and numerical methods that can be used to overcome these limitations. In this study, both empirical and numerical methods have been used to assess the stability of an open stope located between mine levels N9225 and N9250 at Diavik diamond underground mine. It was shown that the numerical methods can be used as complementary methods along with other analytical and empirical methods to assess the stability of open stopes. A three dimensional elastoplastic finite element model was constructed using Abaqus software. In this paper a sensitivity analysis was performed to investigate the impact of the stress ratio “k” on the extent of the yielding and relaxation zones around the hangingwall and footwall of the understudy stope.
Prognozowanie stabilności przodka wybierkowego stanowi poważne wyzwanie dla inżynierów górnictwa. Przez dziesięciolecia na całym świecie do projektowania przodka wybierkowego prowadzonego bez obudowy wykorzystywano metodę graficzną jako pierwszy etap prac. Jednakże metoda ta ma pewne niedogodności. Przykładowo, nie uwzględnia występowania stref odprężania wokół przodka. Innym ograniczeniem metody graficznej jest to, iż nie może być ona wykorzystana do oceny stabilności przodków w których ściany zawierają materiał podsadzany. Istnieją jednak metody analityczne i numeryczne, które pozwalają na przezwyciężenie tych ograniczeń. W pracy tej wykorzystano zarówno metody empiryczne jak i numeryczne do oceny stabilności przodka wybierkowego zlokalizowanego pomiędzy poziomami N9225 i N9250 w podziemnej kopalni diamentów w Diavik. Wykazano, że metody numeryczne stanowią znakomite uzupełnienie metod analitycznych i empirycznych wykorzystywanych do oceny stabilności przodków wybierkowych. Opracowano trójwymiarowy model elastyczno-plastycznych elementów skończonych z wykorzystaniem oprogramowania Abaqus. W pracy tej przeprowadzono analizę wrażliwości i zbadano wpływ wskaźnika stosunku naprężeń "k" na zasięg osiadania i powstanie stref odprężenia wokół warstw stropu i spągu w badanym przodku wybierkowym.
Źródło:
Archives of Mining Sciences; 2017, 62, 3; 653-669
0860-7001
Pojawia się w:
Archives of Mining Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A review of progress in current research on Chinese flowering cabbage (Brassica campestris L. ssp. chinensis var. utilis Tsen et Lee)
Autorzy:
Liu, W.
Liu, Y.
Kleiber, T.
Powiązania:
https://bibliotekanauki.pl/articles/1192785.pdf
Data publikacji:
2021
Wydawca:
Uniwersytet Warmińsko-Mazurski w Olsztynie / Polskie Towarzystwo Magnezologiczne im. Prof. Juliana Aleksandrowicza
Tematy:
Chinese flowering cabbage
nutritional value
yield
breeding
Opis:
Chinese flowering cabbage (Brassica campestris L. ssp. chinensis var. utilis Tsen et Lee) is an important leafy vegetable species, which originates from Guangdong province in southern China. There is a variety called purple Chinese flowering cabbage (Brassica campestris L. ssp. chinensis L. Makino var. purpurea Bailay), which is popular in the Yangtze River basin, e.g. in Wuhan and Sichuan provinces. This manuscript is a review of recent studies on the nutritional value, breeding methods and factors affecting the yield of Chinese flowering cabbage. This vegetable is rich in glucosinolates, polyphenols, amino acids, fatty acids, soluble sugar and vitamin C. It also exhibits some antioxidative activity, e.g. the TEAC value was 16.93 μmol Trolox g-1 and the FRAP value was 12.01 µmol Fe(II) g-1 in total. Controlling the Cd level in Chinese flowering cabbage is important due to the fact that it can easily accumulate Cd in its edible leaves and flowering stems. To reduce the effect given by Cd, foliar spray with trace elements had been studied. Moreover, nitrogen fertilizer, biofertilizer and several cultivation methods have been implemented to improve the yielding and nutritional value of Chinese flowering cabbage. Depending on the conditions, fertilisation increased the yield from 19.1% to 168%, whereas the fresh weight of a single plant varied from 0.835 kg to 1.683 kg and the average yielding in the field ranged from 7.857 t ha-1 to 19.1 t ha-1. In the last part of this paper, we reviewed the different breeding methods that have been used to develop new varieties of Chinese flowering cabbage meeting specific requirements, such as selecting a hybrid with kale to enrich the genotype, increase the resistance or discover a specific bolting gene. In brief, Chinese flowering cabbage has the potential for future research and commercial market.
Źródło:
Journal of Elementology; 2021, 26, 1; 149-162
1644-2296
Pojawia się w:
Journal of Elementology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Quantitative analysis of the relationship between shear strength and fractal dimension of solidified dredger fill with different fly ash content under monotonic shear
Autorzy:
Yang, S.
Liu, W.
Liu, H.
Powiązania:
https://bibliotekanauki.pl/articles/258498.pdf
Data publikacji:
2018
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
curing agent
fly ash
shear strength
fractal dimension
SEM
Opis:
The dredger fill of Shanghai Hengsha Island Dongtan is solidified by curing agents with different fly ash content, and the shear strength index of solidified dredger fill is measured by the direct shear test. The microscopic images of solidified dredger fill are obtained by using SEM. The microscopic images are processed and analyzed by using IPP, and the fractal dimension including particle size fractal dimension Dps, aperture fractal dimension Dbs and particle surface fractal dimension Dpr is calculated by fractal theory. The quantitative analysis of the relationship between shear strength index and fractal dimension of solidified dredger fill is done. The research results show that the internal friction angle and the cohesion are closely related to the fly ash content λ and the curing period T, and the addition of fly ash can improve the effect of curing agent; There is no obvious linear relationship between the internal friction angle and the three fractal dimensions; The smaller particle surface fractal dimension Dpr and particle size fractal dimension Dps, the larger aperture fractal dimension Dbs, the greater the cohesion, and the cohesion has a good linear relationship with three fractal dimensions, and the correlation coefficient R2 is above 0.91.
Źródło:
Polish Maritime Research; 2018, S 2; 132-138
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Degradation mechanism study of amine collectors in Fenton process by quantitative structure-activity relationship analysis
Autorzy:
Wang, X.
Liu, W.
Duan, H.
Powiązania:
https://bibliotekanauki.pl/articles/110363.pdf
Data publikacji:
2018
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
amine collectors
Fenton process
QSAR
degradation mechanism
quantum chemistry
Opis:
In this study, advanced oxidation processes (AOPs), Fenton process, was applied to degrade ten amine collectors. The experimental results indicated that most of the tested amines could be removed rapidly and effectively at pH=4, while the degradation of quaternary ammonium compounds was less than others. To research the Fenton oxidation process, the degradation-rate constants of amine collectors were calculated by the pseudo-second order kinetic model, then which was used as the dependent variable to establish a quantitative structure activity relationship (QSAR) model. Meanwhile, 16 molecular structure descriptors and quantum mechanical parameters for amine collectors were simulated and analyzed by using Materials Studio software. The optimum QSAR model was established based on the partial least squares regression (PLS) method and confirmed by the statistics analysis. The model revealed that hydrogen bond acceptor (HBA) and the maximum values of electrophilic attack in C atom sites (f(-)c) were the major effect factors for the degradation-rate constants of amine collector.
Źródło:
Physicochemical Problems of Mineral Processing; 2018, 54, 3; 713-721
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Experimental study on amplitude-frequency characteristic and basin stability of horizontally driven pendulum
Autorzy:
Jia, J.
Wu, Y.
Liu, W.
Xiao, J.
Powiązania:
https://bibliotekanauki.pl/articles/281610.pdf
Data publikacji:
2016
Wydawca:
Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
Tematy:
horizontally driven pendulum system
bifurcation
basin stability
Opis:
In this article, an inverted pendulum system is set up to explore the dynamics of a horizontally driven pendulum which exhibits a great variety of dynamical behavior and appears in a wide range of applications in the field of engineering. The facility is efficient to experimentally explore two kinds of coexisting movement patterns in the horizontally driven pendulum, i.e. in-phase and anti-phase patterns between the angular velocity of the pendulum rod and the direction of the driving forces. Theoretical analysis is applied to reveal the regimes of the coexistence of the two movement patterns, which is promising to control the system to a desired pattern.
Źródło:
Journal of Theoretical and Applied Mechanics; 2016, 54, 3; 839-846
1429-2955
Pojawia się w:
Journal of Theoretical and Applied Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The port service ecosystem research based on the Lotka-Volterra model
Autorzy:
Li, W.
Liu, W.
Xu, X.
Gao, Z.
Powiązania:
https://bibliotekanauki.pl/articles/259265.pdf
Data publikacji:
2017
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
port service ecosystem
niche breadth
competitive co-evolution
mutually beneficial co-evolution
Opis:
Under the new normal of China’s economy, the competition among the port enterprises is not only the competition of the core competence of the port, the port industry chain or the port supply chain, but also the competition of the port service ecosystem. In this paper, the concept and characteristics of the port service ecosystem is discussed, a hierarchical model of the port service ecosystem is constructed. As an extended logistic model, Lotka-Volterra model is applied to study the competitive co-evolution and mutually beneficial co-evolution of enterprises in the port service ecosystem. This paper simulates the co-evolution of enterprises in the port service ecosystem by using MATLAB programming. The simulation results show that the breadth of the niche of the enterprises is changing with the change of the competition coefficient and the coefficient of mutual benefit in the port service ecosystem. Based on that, some proposals are put forward to ensure the healthy and orderly development of the port service ecosystem.
Źródło:
Polish Maritime Research; 2017, S 3; 86-94
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Conjugate numerical investigation of a miniature flat-plate evaporator of a capillary pumped loop for electronics cooling
Autorzy:
Wan, Z.
Liu, W.
Tu, Z.
Nakayama, A.
Powiązania:
https://bibliotekanauki.pl/articles/1933189.pdf
Data publikacji:
2008
Wydawca:
Politechnika Gdańska
Tematy:
capillary pumped loop
flat plate evaporator
sidewall effect heat transfer limit
cooling of electronic devices
Opis:
A capillary pumped loop (CPL) is a two-phase thermal control device applied in cooling electronic devices. A two-dimensional conjugate numerical model of a miniature flat-plate capillary evaporator is presented in order to describe liquid and vapor flow, heat transfer and phase change in the porous wick structure, liquid flow and heat transfer in the compensation cavity and heat transfer in the vapor grooves and the metallic wall. The entire evaporator is solved with the SIMPLE algorithm as a conjugate problem. The shape and location of the vapor-liquid interface inside the wick are calculated, and a side wall effect heat transfer limit is introduced to estimate the evaporator's heat transport capability. The influence of various wall materials on the evaporator's performance is discussed in detail. The results suggest that an evaporator with a combined wall is capable of dissipating high heat flux and stabilizing the temperature of electronic devices at a moderate temperature level.
Źródło:
TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk; 2008, 12, 1-2; 5-19
1428-6394
Pojawia się w:
TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Electrorefining of High Carbon Ferromanganese in Molten Salts to Produce Pure Ferromanganese
Autorzy:
Xiao, S.J.
Liu, W.
Gao, L.
Zhang, J.
Powiązania:
https://bibliotekanauki.pl/articles/353411.pdf
Data publikacji:
2017
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
high carbon ferromanganese
electrorefining
molten salts
pure ferromanganese
Opis:
High carbon ferromanganese is used as a starting material to prepare pure ferromanganese by electrorefining in molten salts. High carbon ferromanganese was applied as the anode, molybdenum was the cathode and Ag/AgCl was the reference electrode. The anodic dissolution was investigated by linear polarization in molten NaCl-KCl system. Then potentiostatic electrolysis was carried out to produce pure ferromanganese from high carbon ferromanganese. The cathodic product was determined to be a mixture of manganese and iron by x-ray diffraction (XRD). The content of carbon in the product was analyzed by carbon and sulfur analyzer. The post-electrolysis anode was characterized by scanning electron microscope (SEM). The mechanism of the anode dissolution and the distribution of the main impurity of carbon and silicon after electrolysis were discussed.
Źródło:
Archives of Metallurgy and Materials; 2017, 62, 3; 1505-1509
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
3-D simulation of vertical-axial tidal current turbine
Autorzy:
Zhang, Z.
Ma, Y.
Jiang, J.
Liu, W.
Ma, Q.
Powiązania:
https://bibliotekanauki.pl/articles/260421.pdf
Data publikacji:
2016
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
tidal current energy
vertical-axial turbine
hydrodynamic performance
CFD
numerical simulation
3-D effect
Opis:
Vertical-axial tidal current turbine is the key for the energy converter, which has the advantages of simple structure, adaptability to flow and uncomplex convection device. It has become the hot point for research and application recently. At present, the study on the hydrodynamic performance of vertical-axial tidal current turbine is almost on 2-D numerical simulation, without the consideration of 3-D effect. CFD (Computational Fluid Dynamics) method and blade optimal control technique are used to improve accuracy in the prediction of tidal current turbine hydrodynamic performance. Numerical simulation of vertical-axial tidal current turbine is validated. Fixed and variable deflection angle turbine are comparatively studied to analysis the influence of 3-D effect and the character of fluid field and pressure field. The method, put the plate on the end of blade, of reduce the energy loss caused by 3-D effect is proposed. The 3-D CFD numerical model of vertical-axial tidal current turbine hydrodynamic performance in this study may provide theoretical, methodical and technical reference for the optimal design of turbine.
Źródło:
Polish Maritime Research; 2016, 4; 73-83
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Measurable realistic image-based 3D mapping
Autorzy:
Liu, W.
Wang, J.
Wang, J. J.
Ding, W.
Almagbile, A.
Powiązania:
https://bibliotekanauki.pl/articles/130115.pdf
Data publikacji:
2011
Wydawca:
Stowarzyszenie Geodetów Polskich
Tematy:
three-dimensional map
multi-sensor
measurable image
virtual reality
mapa trójwymiarowa
multisensor
rzeczywistość
Opis:
Maps with 3D visual models are becoming a remarkable feature of 3D map services. High-resolution image data is obtained for the construction of 3D visualized models.The3D map not only provides the capabilities of 3D measurements and knowledge mining, but also provides the virtual experienceof places of interest, such as demonstrated in the Google Earth. Applications of 3D maps are expanding into the areas of architecture, property management, and urban environment monitoring. However, the reconstruction of high quality 3D models is time consuming, and requires robust hardware and powerful software to handle the enormous amount of data. This is especially for automatic implementation of 3D models and the representation of complicated surfacesthat still need improvements with in the visualisation techniques. The shortcoming of 3D model-based maps is the limitation of detailed coverage since a user can only view and measure objects that are already modelled in the virtual environment. This paper proposes and demonstrates a 3D map concept that is realistic and image-based, that enables geometric measurements and geo-location services. Additionally, image-based 3D maps provide more detailed information of the real world than 3D model-based maps. The image-based 3D maps use geo-referenced stereo images or panoramic images. The geometric relationships between objects in the images can be resolved from the geometric model of stereo images. The panoramic function makes 3D maps more interactive with users but also creates an interesting immersive circumstance. Actually, unmeasurable image-based 3D maps already exist, such as Google street view, but only provide virtual experiences in terms of photos. The topographic and terrain attributes, such as shapes and heights though are omitted. This paper also discusses the potential for using a low cost land Mobile Mapping System (MMS) to implement realistic image 3D mapping, and evaluates the positioning accuracy that a measureable realistic image-based (MRI) system can produce. The major contribution here is the implementation of measurable images on 3D maps to obtain various measurements from real scenes.
Źródło:
Archiwum Fotogrametrii, Kartografii i Teledetekcji; 2011, 22; 297-310
2083-2214
2391-9477
Pojawia się w:
Archiwum Fotogrametrii, Kartografii i Teledetekcji
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Low-Frequency Mechanical Spectroscopy of Lanthanum Cobaltite Based Mixed Conducting Oxides
Autorzy:
Wu, X. S.
Cao, J. F.
Chen, Z. J.
Liu, W.
Powiązania:
https://bibliotekanauki.pl/articles/355599.pdf
Data publikacji:
2016
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
mixed conducting oxides
mechanical properties
domain structure
phase transition
mechanical spectroscopy
internal friction
Opis:
The low-frequency mechanical spectra of lanthanum cobaltite based mixed conducting oxides have been measured using a computer-controlled inverted torsion pendulum. The results indicate that the internal friction spectra and shear modulus depend on the Sr doping contents (x). For undoped samples, no internal friction peak is observed. However, for La0.8Sr0.2CoO3-δ, three internal friction peaks (P2, P3 and P4) are observed. In addition to these peaks, two more peaks (P0 and P1) are observed in La0.6Sr0.4CoO3‒δ. The P0 and P1 peaks show characteristics of a phase transition, while the P2, P3 and P4 peaks are of relaxation-type. Our analysis suggests that the P0 peak is due to a phase separation and the P1 peak is related to the ferromagnetic–paramagnetic phase transition. The P2, P3 and P4 peaks are associated with the motion of domain walls. The formation of this kind of domain structure is a consequence of a transformation from the paraelastic cubic phase to the ferroelastic rhombohedral phase. With partial substitution of Fe for Co, only one peak is observed, which is discussed as a result of different microstructure.
Źródło:
Archives of Metallurgy and Materials; 2016, 61, 3; 1733-1738
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
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