Informacja

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

English (EN)·Polski (PL)·Yкраїнський (UK)
Przejdź do strony domowej biblioteki Centralna Biblioteka Wojskowa Link otwiera się w nowym oknie Logo biblioteki Prolib Integro - strona głównaCentralna Biblioteka Wojskowa

Wyszukujesz frazę "Zhang, Hao" wg kryterium: Autor

  Lista filtrów
Wyrównaj
Wyświetlanie 1-15 z 28
Tytuł:
An accurate and stable pose estimation method for planar cases considering the line constraints between every two points
Autorzy:
Zhang, Zimiao
Zhang, Hao
Zhang, Fumin
Zhang, Shihai
Powiązania:
https://bibliotekanauki.pl/articles/27311739.pdf
Data publikacji:
2023
Wydawca:
Polska Akademia Nauk. Czasopisma i Monografie PAN
Tematy:
pose estimation
line constraints
coplanar
non-iterative
Opis:
The current solutions for pose estimation problems using coplanar feature points (PnP problems) can be divided into non-iterative and iterative solutions. The accuracy, stability, and efficiency of iterative methods are unsatisfactory. Therefore, non-iterative methods have become more popular. However, the non-iterative methods only consider the correspondence of the feature points with their 2D projections. They ignore the constraints formed between feature points. This results in lower pose estimation accuracy and stability. In this work, we proposed an accurate and stable pose estimation method considering the line constraints between every two feature points. Our method has two steps. In the first step, we solved the pose non-iteratively, considering the correspondence of the 3D feature points with their 2D projections and the line constraints formed by every two feature points. In the second step, the pose was refined by minimizing the re-projection errors with one iteration, further improving accuracy and stability. Simulation and actual experiment results show that our method’s accuracy, stability, and computational efficiency are better than the other existing pose estimation methods. In the -45° to +45° measuring range, the maximum angle measurement error is no more than 0.039°, and the average angle measurement error is no more than 0.016°. In the 0 mm to, 30 mm measuring range, the maximum displacement measurement error is no more than 0.049 mm, and the average displacement measurement error is no more than 0.012 mm. Compared to other current pose estimation methods, our method is the most efficient based on guaranteeing measurement accuracy and stability.
Źródło:
Metrology and Measurement Systems; 2023, 30, 2; 235--258
0860-8229
Pojawia się w:
Metrology and Measurement Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Electrokinetic remediation technology of heavy metal contaminated soil based on improving soil electrical conductivity
Autorzy:
Liu, Jiangang
Zhang, Wei
Liu, Mingwei
Zhang, Hao
Powiązania:
https://bibliotekanauki.pl/articles/2032843.pdf
Data publikacji:
2021
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
soil pollution
heavy metals
NaCl
electrical conductivity
soil remediation
skażenie gleby
metale ciężkie
przewodność elektryczna
remediacja gleb
Opis:
An electrokinetic remediation technique taking Cr(VI) as an example is proposed to improve the conductivity of contaminated soil, which significantly increases the current density in the soil. The improvement of soil conductivity was achieved by continuous spraying of NaCl solution with a concentration of 4 g·dm–3 on the soil surface. The distances of electrode pairs were 2.0 m and 1.5 m, respectively. The heavy metal-contaminated soil thickness was 25 cm, and the DC power supply voltage was 90 V. The experiment demonstrated that under the condition of continuous spraying of NaCl solution on the soil surface, the current density variation was related to the salt content in the soil, and the current density in the soil generally increased linearly with time. The effectiveness of soil remediation is related to the electric field strength and current density, and there exists an optimal electric field that can reduce the heavy metal content in the soil at any point by minimizing the electric field strength and current density. Most of the heavy metals can be concentrated within a diameter of about 15 cm around the anode under the optimal electric field, which can be remediated after removing the soil.
Źródło:
Environment Protection Engineering; 2021, 47, 4; 5-17
0324-8828
Pojawia się w:
Environment Protection Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Research on beam supply control strategy based on sliding mode control
Autorzy:
Zhang, Hao
Dong, Haiying
Zhang, Baoping
Wu, Tong
Chen, Changwen
Powiązania:
https://bibliotekanauki.pl/articles/141014.pdf
Data publikacji:
2020
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
beam supply
DC/DC converter
robustness
sliding mode control
Opis:
In the hybrid multiple H-bridge topology of beam supply, the load change of a DC/DC full-bridge converter can greatly affect the output voltage during onsite operation. An improved sliding mode control (SMC) strategy is thus proposed in this paper, where the rate of switching control is added to the law of system equivalent control to create a law that can realize a complete sliding mode control. Considering the special operating conditions of the load can have an influence on the performance of the controller, the impact of uncertainty existing in onsite conditions is suppressed with the proposed strategy utilized. The validity of the proposed strategy, finally, is verified by simulation, which proves the outperformance of the system in both robustness and dynamics.
Źródło:
Archives of Electrical Engineering; 2020, 69, 2; 349-364
1427-4221
2300-2506
Pojawia się w:
Archives of Electrical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Tool wear condition monitoring in milling process based on data fusion enhanced long short-term memory network under different cutting conditions
Autorzy:
Zheng, Guoxiao
Sun, Weifang
Zhang, Hao
Zhou, Yuqing
Gao, Chen
Powiązania:
https://bibliotekanauki.pl/articles/2038054.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Polskie Naukowo-Techniczne Towarzystwo Eksploatacyjne PAN
Tematy:
tool wear condition monitoring
empirical mode decomposition
variational mode decomposition
fourier synchro squeezed transform
neighborhood component analysis
long short-term memory network
Opis:
Tool wear condition monitoring (TCM) is essential for milling process to ensure the machining quality, and the long short-term memory network (LSTM) is a good choice for predicting tool wear value. However, the robustness of LSTM- based method is poor when cutting condition changes. A novel method based on data fusion enhanced LSTM is proposed to estimate tool wear value under different cutting conditions. Firstly, vibration time series signal collected from milling process are transformed to feature space through empirical mode decomposition, variational mode decomposition and fourier synchro squeezed transform. And then few feature series are selected by neighborhood component analysis to reduce dimension of the signal features. Finally, these selected feature series are input to train the bidirectional LSTM network and estimate tool wear value. Applications of the proposed method to milling TCM experiments demonstrate it outperforms significantly SVR- based and RNN- based methods under different cutting conditions.
Źródło:
Eksploatacja i Niezawodność; 2021, 23, 4; 612-618
1507-2711
Pojawia się w:
Eksploatacja i Niezawodność
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Strain measurement based on fixed wavelength transmission of tapered long-period fiber grating
Autorzy:
Tang, Yong
Zhang, Hao
Zhang, Li
Yu, Xin Feng
Bai, Yun Feng
Powiązania:
https://bibliotekanauki.pl/articles/2172862.pdf
Data publikacji:
2022
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
tapered fiber
long-period fiber
fiber grating
strain sensor
fixed dual-wavelength ratio
Opis:
This paper studies the relationship between transmission intensity and strain based on tapered long-period fiber grating at a fixed wavelength. In experiments, tapered long-period fiber grating was prepared by the electric melting method. Experimental results show that two resonance peaks appeared at 1482 and 1537 nm, respectively. Here is the elaboration of the relationship between the resonant wavelength and the strain, its wavelength-strain sensitivity is 20 pm/με, and the linearity was negative. Then our next study was about the relationship between transmission intensity and strain at a fixed wavelength. The results show that the transmission intensity at a fixed wavelength is related to the exponent with strain. The coupled-mode theory is applied to simulate the relationship between fixed wavelength and strain. The simulation results matched the experimental results. Two fixed wavelength transmission intensity ratio was used, and the ratio showed a linear relationship with the strain, and the slope is –0.018 dB/με. Therefore, within the 0.01% resolution of our detector, we could resolve a 0.16 με strain change. We can select the appropriate light source and detector to achieve higher measurement accuracy. Thus, there is a great potential in fiber grating strain sensors.
Źródło:
Optica Applicata; 2022, 52, 4; 511--519
0078-5466
1899-7015
Pojawia się w:
Optica Applicata
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Comparative experiment study on nitrogen injection and free desorption of methane-rich bituminous coal under triaxial loading
Eksperymenty i badania porównawcze efektów wstrzykiwania azotu i swobodnej desorpcji na węglu bitumicznym o wysokiej zawartości metanu w warunkach obciążeń trójosiowych
Autorzy:
Zhang, L.
Ye, Z.
Tang, J.
Hao, D.
Zhang, C.
Powiązania:
https://bibliotekanauki.pl/articles/219975.pdf
Data publikacji:
2017
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
wstrzykiwanie gazu
metan
tempo wypierania
swobodna desorpcja
gas injection
methane
displacement ratio
free desorption
Opis:
As a kind of associated geological gas, coalbed methane (CBM) is mainly adsorbed in the coal seam. The coal-methane adsorption phenomenon can be described by Langmuir monolayer adsorptio n model, BET multilayer adsorption model and the Theory of Volume Filling of Micropore (TVFM), whereas the binary gas adsorption phenomenon can be described by the extended Langmuir Model. For the CBM in the low permeability coal seam, the amount of gas released by direct drainage is relatively limited, which cannot eliminate the gas explosion and outburst hazards. Gas injection is an effective method to promote methane drainage. In this paper, the free desorption and nitrogen injection displacement experiments are comparatively analyzed, which allows verifying the effectiveness of nitrogen injection’s enhancement to gas drainage. The experiment of injecting nitrogen gas into the coal body shows that the coal fracture can be maintained or expanded by the injected gas pressure so that more methane can be released. The nitrogen injection has a higher time efficiency than that of free desorption as well. The displacement ratio of N2/CH4 is in the range of 1-3. Both the injection pressure and confining pressure affect the displacement ratio. The analysis of the desorbed gas components shows that the relationship between the methane component and gas flooding time is an “inverted S” shape curve, and the appropriate time for the methane collection can be inferred by the time interval of the rapid decline of the curve.
Metan zawarty w złożu węgla występuje w głównej mierze w postaci zaadsorbowanej, jako gaz związany. Zjawisko adsorpcji metanu na węglu opisuje model adsorpcji jednowarstwowej Langmuira, model adsorpcji wielowarstwowej BET oraz teoria objętościowego wypełniania mikroporów. Z kolei procesy desorpcji mieszanin dwóch gazów opisuje rozszerzony model Langmuira. W przypadku metanu zawartego w złożu węgla o niskiej przepuszczalności, ilość gazu uwalnianego poprzez proste odgazowanie jest ograniczona i wciąż nie eliminuje ryzyka wybuchu gazu oraz wyrzutu skał i gazu. Wstrzykiwanie gazów jest jedną ze skutecznych metod odgazowania. W pracy tej przeprowadzono badanie porównawcze rezultatów swobodnej desorpcji gazu oraz wstrzyknięcia do złoża azotu, w celu zademonstrowania skuteczności odgazowania poprzez wprowadzenie azotu. Eksperyment polegający na wstrzykiwaniu azotu do calizny węglowej pokazuje możliwość zachowania lub powiększenia pęknięć w strukturze węgla pod działaniem ciśnienia wstrzykiwanego gazu, co umożliwi uwolnienie większych ilości metanu. Ponadto, wprowadzenie azotu okazuje się rozwiązaniem skuteczniejszym w dłuższym okresie czasu niż swobodna desorpcja. Stosunek wypierającego metan N2 do CH4 wynosi w przybliżeniu 1:3. Zarówno ciśnienie wstrzykiwanego gazu jak i wielkość ciśnienia złożowego mają wpływ na tempo wypierania metanu przez azot. Analiza składników desorbowanego gazu wskazuje, że zależność ilości metanu od czasu wypływu gazu opisywana jest na wykresie krzywą w postaci odwróconej litery S, zaś odpowiedni czas na odzysk metanu odczytujemy jako przedział odpowiadający nagłemu obniżeniu widocznemu na wykresie.
Źródło:
Archives of Mining Sciences; 2017, 62, 4; 911-928
0860-7001
Pojawia się w:
Archives of Mining Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The 1/3rd subharmonic and 3rd superharmonic resonance of a shape memory alloy (SMA) laminated beam
Autorzy:
Zhang, Xia Hui
Gao, Ming
Hao, Ying
Powiązania:
https://bibliotekanauki.pl/articles/1839701.pdf
Data publikacji:
2021
Wydawca:
Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
Tematy:
SMA laminated beam
subharmonic resonance
superharmonic resonance
transition set
Opis:
This paper examines the 1/3rd subharmonic resonance and the 3rd superharmonic resonance of simply-supported shape memory alloy (SMA) laminated beams. First, the dynamic equation for SMA laminated beams under transverse load is established using physical equations, force equilibrium conditions, the compatibility equation of deformation, and a constitutive model of SMA polynomial functions. Then, a differential equation for transverse vibration of the SMA laminated beams is derived by the Galerkin process assuming the boundary conditions for simply-supported beams. Next, the amplitude-frequency response equations for the 1/3rd subharmonic resonance and the 3rd superharmonic resonance of these beams are derived by an averaging method before their respective transition sets are calculated, and their amplitude-frequency response diagrams were plotted using singularity theory. The results show two different types of amplitude-frequency responses to nonlinear vibration under the 1/3rd subharmonic resonance and the 3rd superharmonic resonance: quasi-linear and hard characteristic. In the quasi-linear area, SMA thickness A does not make much difference to the response of the system, whereas in the hard-characteristics area, under the same excitation amplitude f, the resonance frequency increases with A. In the nonlinear area, SMA can obviously reduce vibration amplitude, but it is not obvious for the 1/3rd subharmonic resonance. The nonlinear solution of both the 1/3rd subharmonic resonance and 3rd superharmonic resonance are stable.
Źródło:
Journal of Theoretical and Applied Mechanics; 2021, 59, 1; 27-41
1429-2955
Pojawia się w:
Journal of Theoretical and Applied Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Compressive-sensing-based double-image encryption algorithm combining double random phase encoding with Josephus traversing operation
Autorzy:
Jiang, Hao
Nie, Zhe
Zhou, Nanrun
Zhang, Wenquan
Powiązania:
https://bibliotekanauki.pl/articles/173461.pdf
Data publikacji:
2019
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
image encryption
compressive sensing
double random phase encoding
Josephus traversing
Opis:
A double-image encryption scheme based on compressive sensing is designed by combining a double random phase encoding technique with Josephus traversing operation. Two original images are first compressed and encrypted by compressive sensing in the discrete wavelet domain and then connected into a complex image according to the order of the alternate rows. Moreover, the resulting image is re-encrypted into stationary white noise by a double random phase encoding technique. Lastly, Josephus traversing method is utilized to scramble the transformed image. The initial states of the Henon chaotic map are the secret keys of this double-image encryption algorithm, which can be used to control the construction of the measurement matrix in compressive sensing and generation of the random-phase mask in double random phase encoding. Simulation results show that the proposed double-image encryption algorithm is effective and secure.
Źródło:
Optica Applicata; 2019, 49, 3; 445-459
0078-5466
1899-7015
Pojawia się w:
Optica Applicata
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Variation of strata pressure and axial bolt load at a coal mine face under the effect of a fault
Zmienność ciśnienia górotworu i obciążenia osiowe działające na segmenty obudowy w rejonie przodka spowodowane obecnością uskoków
Autorzy:
Shi, Hao
Zhang, Houquan
Song, Lei
Wu, Yu
Powiązania:
https://bibliotekanauki.pl/articles/218749.pdf
Data publikacji:
2019
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
symulacje numeryczne FLAC 3D
naprężenia osiowe działające na obudowę
zachowanie górotworu
górnictwo
efekt uskoku
model odprężania
FLAC3D numerical simulation
axial bolt load
strata behavior
mining and fault effect
strain-softening model
Opis:
The cohesion and internal friction angle were characterized as quadratic functions of strain and were assumed to follow the Mohr-Coulomb criterion after the yield of peak strength. These mechanical parameters and their variations in post-peak softening stage can be exactly ascertained through the si-multaneous solution based on the data points of stress-strain curves of triaxial compression tests. Taking the influence of the fault into account, the variation of strata pressure and roadway convergence with coal advancement, the temporal and spatial distribution of axial bolt load were numerically simulated by FLAC3D (Fast Lagrangian Analysis of Continua) using the ascertained post-peak mechanical parameters according to the cohesion weakening and friction strengthening model. The change mechanism of axial load of single rock bolt as abutment pressure changes was analyzed, through the comparison analysis with the results of axial bolt load by field measurements at a coal mine face. The research results show that the simulated results such as the period of main roof weighting, temporal and spatial distribution of axial bolt load are in accordance with field measurement results, so the validity of the numerical model is testified. In front of the working face, the front abutment pressure increases first and then decreases, finally tends to be stable. A corresponding correlation exists between the variation of axial bolt load and rock deformation along the bolt body. When encountered by a fault, the maximum abutment pressure, the influential range of mining disturbance and the roadway convergence between roof and floor before the working face are all increased. In the roadways along the gob, axial bolt loads on the side of the working face decrease, while the other side one increases after the collapse of the roof. As superficial surrounding rock mass is damaged, the anchoring force of rock bolts will transfer to inner rock mass for balancing the tensile load of the bolts.
Zwięzłość skał oraz kąt tarcia wewnętrznego zdefiniowano jako kwadratowe funkcje naprężenia, następnie przyjęto że ich rozkład po osiągnięciu naprężenia granicznego opisany jest wzorem Mohra-Coulomba. Wymienione parametry mechaniczne i ich zmienność po osiągnięciu naprężenia granicznego obliczyć można dokładnie poprzez jednoczesne rozwiązanie oparte o analizę punktów na krzywej wykresu rozciągania uzyskanych w testach ściskania trójosiowego. Uwzględniając wpływ obecności uskoku, zmienność ciśnienia w górotworze i konwergencji chodnika wraz z postępem przodka, rozkłady naprę-żeń i obciążeń działających na segmenty obudowy i ich zmienność w czasie i przestrzeni modelowano w oparciu o pakiet FLAC3D (Fast Lagrangian Analysis of Continua), wykorzystując uprzednio obliczone wielkości parametrów mechanicznych dla stanu po osiągnięciu naprężenia granicznego, zgodnie z mo-delem słabnącej zwięzłości i wzmocnionego tarcia. Mechanizm zmiany naprężeń osiowych działających na pojedynczy segment obudowy analizowano w odniesieniu do ciśnienia warstw sąsiadujących, poprzez analizę porównawczą wyników pomiarów obciążeń segmentów obudowy w rejonie przodka. Wykazano, że wyniki symulacji: okresy obciążenia stropu, rozkłady naprężeń i obciążeń działających na elementy obudowy i ich zmienność w czasie i przestrzeni zgodne są z wynikami pomiarów w miejscu, w ten sposób potwierdzając wiarygodność modelu numerycznego. W rejonie przodka ciśnienie warstw sąsiadujących w górotworze najpierw rośnie, następnie maleje, a w końcu stabilizuje się. Istnieje odpowiednia korelacja pomiędzy zmiennością rozkładu naprężeń i obciążeń działających na elementy obudowy a odkształceniem warstw skalnym wzdłuż konstrukcji obudowy. W przypadku wystąpienia uskoku, występuje maksymalne ciśnienie warstw otaczających- poważny czynnik powodujący wszelkiego rodzaju zaburzenia a także nasilenie konwergencji chodnika pomiędzy stropem a podłożem w rejonie przed przodkiem. W chodnikach wzdłuż zrobów, obciążenia osiowe obudowy działające z jednej strony maleją, po drugiej zaś stronie rejonu przodkowego rosną po zawale stropu. Płytka warstwa otaczającego górotworu ulega zniszczeniu, siła podtrzymująca obudowę przeniesiona zostanie wewnątrz górotworu, tak by zrównoważyć naprężenia rozciągające działające na obudowę.
Źródło:
Archives of Mining Sciences; 2019, 64, 2; 351-374
0860-7001
Pojawia się w:
Archives of Mining Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Dynamic and resonance response analysis for a turbine blade with varying rotating speed
Autorzy:
Wang, D.
Hao, Z.
Chen, Y.
Zhang, Y.
Powiązania:
https://bibliotekanauki.pl/articles/280027.pdf
Data publikacji:
2018
Wydawca:
Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
Tematy:
varying rotating speed
van der Pol oscillation
ultiple scale methodnonlinear response
bifurcation curve
Opis:
A coupling model between turbine blades with a varying rotating speed and oncoming vortices is constructed, where the coupling of the structure and the fluid is simulated by the van der Pol oscillation. Partial differential governing equations of motions for the coupled system are obtained and discretized by using the Galerkin method. The 1:2 subharmonic resonance and the 1:1 internal resonance are investigated with the multiple scale method and first-order averaged equations are then derived. Nonlinear responses and bifurcation characteristics are studied by a numerical integration method. Stability of bifurcation curves is determined by utilizing the Routh-Hurwitz criterion. The effect of system parameters including the detuning parameter, steady-state rotating speed, amplitude of periodic perturbation for the rotating speed and freestream velocity on vibration responses are investigated.
Źródło:
Journal of Theoretical and Applied Mechanics; 2018, 56, 1; 31-42
1429-2955
Pojawia się w:
Journal of Theoretical and Applied Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The effect of sodium carboxymethyl cellulose on the entrainment of zoisite in flotation
Autorzy:
Zhang, Zhengjun
Ou, Leming
Jin, Saizhen
Zhou, Hao
Powiązania:
https://bibliotekanauki.pl/articles/1448039.pdf
Data publikacji:
2021
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
entrainment
zoisite
froth stability
flotation
CMC flocculation
Opis:
During flotation, fine gangue minerals can enter the concentrate through mechanical entrainment, which seriously affects the quality of concentrate. In this work, the effect of sodium carboxymethyl cellulose (CMC) on the flotation performance of zoisite, a silicate mineral, was studied. The role of CMC in reducing zoisite entrainment was investigated by dynamic foaming tests, surface tension measurements, rheology measurements, sedimentation tests, and optical microscopy experiments. The flotation results showed that zoisite mainly entered the concentrate by entrainment; the addition of low dosages of CMC decreased zoisite entrainment and efficiently separated cassiterite from zoisite; moreover, the concentrate grade and recovery of SnO2 increased by 1.27 % and 5.63 %, respectively, by using CMC in closed-circuit flotation tests. Dynamic foaming studies on the two-phase and three-phase foam/froth revealed that the presence of CMC decreased the froth ability and froth stability, and greatly altered the three-phase froth structure. Basically, the bubbles in the foam were larger after adding CMC. For the two-phase foam, the change of foam property had little to do with surface activity and bulk viscosity. For the three-phase froth, the froth property was strongly affected by the interaction of CMC and zoisite. The results of the sedimentation test and microscopy experiment demonstrated that CMC can cause zoisite to flocculate and enlarge the particle size, which was the main reason for the decrease of froth stability and entrainment. This study indicates that the side effects of depressants should not be overlooked when discussing the role of depressants in flotation.
Źródło:
Physicochemical Problems of Mineral Processing; 2021, 57, 2; 34-47
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Automatic pavement macrotexture depth calculation using a statistical approach based on the tire/road noise signal by directional microphones
Autorzy:
Liu, Hao
Zhang, Yiying
Xu, Zhengwei
Liu, Xiaojiang
Powiązania:
https://bibliotekanauki.pl/articles/2173668.pdf
Data publikacji:
2022
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
statistical approach
directional microphone
pavement
macrotexture depth
automation
podejście statystyczne
mikrofon kierunkowy
chodnik
głębokość makrotekstury
automatyzacja
Opis:
This paper develops an automatic method to calculate the macrotexture depth of pavement roads, using the tire/road noise data collected by the two directional microphones mounted underneath a moving test vehicle. The directional microphones collect valid tire/road noise signal at the travel speed of 10–110 km/h, and the sampling frequency is 50 kHz. The tire/road noise signal carries significant amount of road surface information, such as macrotexture depth. Using bandpass filter, principal component analysis, speed effect elimination, Gaussian mixture model, and reversible jump Markov Chain Monte Carlo, the macrotexture depth of pavement roads can be calculated from the tire/road noise data, automatically and efficiently. Compared to the macrotexture depth results by the sand-patch method and laser profiler, the acoustic method has been successfully demonstrated in engineering applications for the accurate results of macrotexture depth with excellent repeatability, at the test vehicle’s travel speed of 10-110 km/h.
Źródło:
Bulletin of the Polish Academy of Sciences. Technical Sciences; 2022, 70, 3; art. no. e140519
0239-7528
Pojawia się w:
Bulletin of the Polish Academy of Sciences. Technical Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Reliability modeling for dependent competing failure processes with phase-type distribution considering changing degradation rate
Autorzy:
Lyu, Hao
Wang, Shuai
Zhang, Xiaowen
Yang, Zaiyou
Pecht, Michael
Powiązania:
https://bibliotekanauki.pl/articles/2038056.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Polskie Naukowo-Techniczne Towarzystwo Eksploatacyjne PAN
Tematy:
dependent competing failure processes
phase type distribution
changing degradation rate
reliability modeling
survival function
Opis:
In this paper, a system reliability model subject to Dependent Competing Failure Processes (DCFP) with phase-type (PH) distribution considering changing degradation rate is proposed. When the sum of continuous degradation and sudden degradation exceeds the soft failure threshold, soft failure occurs. The interarrival time between two successive shocks and total number of shocks before hard failure occurring follow the continuous PH distribution and discrete PH distribution, respectively. The hard failure reliability is calculated using the PH distribution survival function. Due to the shock on soft failure process, the degradation rate of soft failure will increase. When the number of shocks reaches a specific value, degradation rate changes. The hard failure is calculated by the extreme shock model, cumulative shock model, and run shock model, respectively. The closed-form reliability function is derived combining with the hard and soft failure reliability model. Finally, a Micro-Electro-Mechanical System (MEMS) demonstrates the effectiveness of the proposed model.
Źródło:
Eksploatacja i Niezawodność; 2021, 23, 4; 627-635
1507-2711
Pojawia się w:
Eksploatacja i Niezawodność
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Homogenization phenomena of surface components of fluorite and calcite
Autorzy:
Sun, Ruofan
Liu, Dan
Zhang, Benyue
Lai, Hao
Wen, Shuming
Powiązania:
https://bibliotekanauki.pl/articles/1448969.pdf
Data publikacji:
2021
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
homogenization phenomena
surface composition
fluorite
calcite
mixed grinding
Opis:
The flotation separation of fluorite and calcite poses one of the most difficult problems in the mineral processing industry. In particular, the surface homogenization of fluorite and calcite worsens the result of fluorite flotation. In this paper, time of flight secondary ion mass spectrometry and principal component analysis are used to study the surface homogenization of fluorite and calcite during grinding and in solution using X-ray photoelectron spectroscopy, infrared spectroscopy, and solution chemical calculations. The results show that the surface composition of calcite converts to fluorite after mixed grinding and that the surface composition of fluorite also converts to calcite in clarified calcite solution.
Źródło:
Physicochemical Problems of Mineral Processing; 2021, 57, 1; 250-258
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Faeces As an Important Pollution Source of Airborne Pathogens in Traveling from Swine Farm
Autorzy:
Liangbin, Zhao
Wenjin, Zhang
Dongmei, Jiang
Lin, Bai
Xiaoxia, Hao
Powiązania:
https://bibliotekanauki.pl/articles/27315760.pdf
Data publikacji:
2023
Wydawca:
Politechnika Koszalińska. Wydawnictwo Uczelniane
Tematy:
air microorganism
16SrRNA high-throughput sequencing
manure
piggery
swine
Opis:
Airborne pathogens are the most important factor causing environmental issues on pig farms. Research on airborne swine-derived microbes has mainly concentrated on several specific microbes or pathogens. The present work was conducted to detect and identify the entire microbial community in piggery air and their dispersion by 16SrRNA sequencing. Fifteen faeces and eighty-four air samples were collected in swine barns and from different distances away from the barns, respectively. The results showed that the faeces and air share the most dominant bacteria. The top 10 genera belonged to Fimicutes, Proteobacteria and Bacteroidetes, and accounted for 54% and 76-84% of the total sequences. Moreover, great higher (P < 0.01) microbial diversity was detected in the faeces. This study indicated that a hygienic interval of 50 m should be set on swine farms to prevent the spreading infectious disease caused by airborne pathogens.
Źródło:
Rocznik Ochrona Środowiska; 2023, 25; 55--67
1506-218X
Pojawia się w:
Rocznik Ochrona Środowiska
Dostawca treści:
Biblioteka Nauki
Artykuł
Wyświetlanie 1-15 z 28

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