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Tytuł:
Optimal configurations of wave energy converter arrays with a floating body
Autorzy:
Zhang, W.
Liu, H.
Zhang, X.
Zhang, L.
Ashraf, M. A.
Powiązania:
https://bibliotekanauki.pl/articles/260084.pdf
Data publikacji:
2016
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
wave energy
cylinder array
power take-off
hydrodynamic analysis
Opis:
An array of floating point-absorbing wave energy converters (WECs) is usually employed for extracting efficiently ocean wave energy. For deep water environment, it is more feasible and convenient to connect the absorbers array with a floating body, such as a semi-submersible bottom-moored disk, whose function is to act as the virtual seabed. In the present work, an array of identical floating symmetrically distributed cylinders in a coaxial moored disk as a wave energy device is proposed The power take-off (PTO) system in the wave energy device is assumed to be composed of a linear/nonlinear damper activated by the buoys heaving motion. Hydrodynamic analysis of the examined floating system is implemented in frequency domain. Hydrodynamic interferences between the oscillating bodies are accounted for in the corresponding coupled equations. The array layouts under the constraint of the disk, incidence wave directions, separating distance between the absorbers and the PTO damping are considered to optimize this kind of WECs. Numerical results with regular waves are presented and discussed for the axisymmetric system utilizing heave mode with these interaction factors, in terms of a specific numbers of cylinders and expected power production.
Źródło:
Polish Maritime Research; 2016, S 1; 71-77
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Biomechanical and fluid flowing characteristics of intervertebral disc of lumbar spine predicted by poroelastic finite element method
Autorzy:
Guo, L.-X
Li, R.
Zhang, M.
Powiązania:
https://bibliotekanauki.pl/articles/307246.pdf
Data publikacji:
2016
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
kręgosłup lędźwiowy
poroelastyczność
FEM
lumbar spine
poroelastic finite element model
intermittent compressive load
permeability of cartilage endplate
Opis:
Purpose: This study is to reveal the deformation of intervertebral disc (IVD), the stress distribution of solid phase and liquid phase, the variation of fluid flux and flow velocity in lumbar spine and the influence of different permeability parameters on them under intermittent compressive loading. Methods: A poroelastic FEM of L4-L5 is assigned with different permeability parameters to analyze the deformation, stress distribution and fluid convection under intermittent compressive loads. Results: The results show that the pore pressure of IVD decreases with time, but the effective stress increases under intermittent compressive loads. The axial and radial strain will increase and fluid loss will recover at a more rapid rate if the permeability of endplate increases during unloading period. The velocity vectors show that most of the liquid in the disc flows into vertebrae through endplates and only a small quantity of liquid flows through the annulus fibrosus at the loading step, however, at the unloading step, almost all the liquid flowing into IVD is through the endplates. Conclusions: The changing rate of pore pressure and effective stresses of nucleus pulposus and annulus fibrosus with higher permeability is smaller than that with smaller permeability. The degenerated endplate (with low permeability) yields high flow velocity decreasing gradient, which might impede liquid inflowing/outflowing smoothly through the endplates. The fluid flowing velocity in loading phase is faster than that in unloading phase, so a short resting time can relieve fatigue, but could not recover to the original liquid condition in IVDs.
Źródło:
Acta of Bioengineering and Biomechanics; 2016, 18, 2; 19-29
1509-409X
2450-6303
Pojawia się w:
Acta of Bioengineering and Biomechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
An integrated model of production scheduling and maintenance planning under imperfect preventive maintenance
Model zintegrowany harmonogramowania produkcji i planowania obsługi technicznej w ramach niepełnej konserwacji zapobiegawczej
Autorzy:
Chen, X.
Xiao, L.
Zhang, X.
Xiao, W.
Li, J.
Powiązania:
https://bibliotekanauki.pl/articles/301817.pdf
Data publikacji:
2015
Wydawca:
Polska Akademia Nauk. Polskie Naukowo-Techniczne Towarzystwo Eksploatacyjne PAN
Tematy:
aperiodic imperfect preventive maintenance
production scheduling
maintenance planning
immune clonal selection algorithm
total profit
nieokresowa niepełna konserwacja zapobiegawcza
harmonogramowanie produkcji
planowanie konserwacji
algorytm odpornościowej selekcji klonalnej
całkowity zysk
Opis:
For a successful company, machines are always required to work continuously to make more profit in a certain period. However, machines can be unavailable due to the scheduled maintenance activities or unexpected failures. Hence, a model connected production scheduling with maintenance planning for a production line which is composed of multiple machines is developed. Suppose preventive maintenance is imperfect and cannot renew all the machines. Age reduction factor and hazard rate increase factor are introduced to illustrate the imperfect character. Aperiodic preventive maintenance policy is adopted. Replacement as perfect maintenance could restore the machine “as good as new”. When and whether to perform replacement is based on a cost-time rate function which is defined to judge whether or not the preventive maintenance is economical. The objective of the joint model is to maximize the total profit which is composed of production value, production cost, maintenance cost (including the preventive maintenance cost and replacement cost), and tardiness cost (which is related to the job sequence and maintenance activities). To optimize the objective, immune clonal selection algorithm is utilized. The proposed model is validated by a numerical example.
Aby firma mogła działać z powodzeniem i przynosić większe zyski w danym okresie czasu, zainstalowane w niej maszyny muszą pracować w sposób nieprzerwany. Niestety, z powodu planowych działań obsługowych lub nieoczekiwanych awarii, maszyny są czasami wyłączane z produkcji. Dlatego też w niniejszym artykule opracowano model łączący harmonogramowanie produkcji z planowaniem obsługi technicznej dla linii produkcyjnej złożonej z wielu maszyn. W pracy założono, że konserwacja zapobiegawcza jest niepełna i nie prowadzi do odnowy wszystkich maszyn. Aby zilustrować jej niepełny charakter, wprowadzono pojęcia czynnika redukcji wieku oraz czynnika wzrostu wskaźnika zagrożenia. Przyjęto politykę nieokresowej konserwacji zapobiegawczej. Wymiana jako forma pełnej konserwacji pozwala na przywrócenie maszyny do stanu "fabrycznej nowości". Kiedy i czy należy przeprowadzić wymianę zależy od funkcji wskaźnika kosztu w stosunku do czasu, który pozwala ocenić, czy konserwacja zapobiegawcza jest opłacalna. Model zintegrowany ma na celu maksymalizację całkowitego zysku, który jest wypadkową wartości produkcji, kosztów produkcji, kosztów obsługi (w tym kosztów konserwacji zapobiegawczej oraz kosztów wymiany) i kosztów nieterminowego zakończenia zadania (ang. lateness, związanych z kolejnością wykonywanych zadań i czynności obsługowych). Aby zoptymalizować opisany cel, wykorzystano algorytm odpornościowej selekcji klonalnej Proponowany model zweryfikowano na przykładzie liczbowym.
Źródło:
Eksploatacja i Niezawodność; 2015, 17, 1; 70-79
1507-2711
Pojawia się w:
Eksploatacja i Niezawodność
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Fast near-infrared palmprint recognition using nonnegative matrix factorization extreme learning machine
Autorzy:
Xu, X.
Zhang, X.
Lu, L.
Deng, W.
Zuo, K
Powiązania:
https://bibliotekanauki.pl/articles/173572.pdf
Data publikacji:
2014
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
extreme learning machine
palmprint recognition
superior speed
support vector machine (SVM)
Opis:
Support vector machine and artificial neural network are widely used in classification applications. Extreme learning machine (ELM) is a novel and efficient learning algorithm based on the generalized single hidden layer feed forward networks, which performs well in classification applications. The research results have shown the superiority of ELM with the existing classical algorithms: support vector machine (SVM) and back propagation neural network. In this study, we firstly propose a novel nonnegative matrix factorization extreme learning machine (NMFELM) to improve the performance of standard ELM method. Then we propose a novel near-infrared palmprint recognition approach based on NMFELM classifier. As the test data, we use the near-infrared palmprint database provided by Hong Kong Polytechnic University. The experimental results demonstrate that the proposed NMFELM method outperforms the standard ELM- and SVM-based methods.
Źródło:
Optica Applicata; 2014, 44, 2; 285-298
0078-5466
1899-7015
Pojawia się w:
Optica Applicata
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Scale effect of cement mortar specimens subjected to high temperatures using uniaxial compressive and splitting tensile tests
Autorzy:
Xiong, L. X.
Zhang, X. J.
Xu, Z. Y.
Geng, D. X.
Powiązania:
https://bibliotekanauki.pl/articles/230921.pdf
Data publikacji:
2020
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
zaprawa cementowa
temperatura wysoka
ściskanie jednoosiowe
rozciąganie przy rozłupywaniu
efekt skali
cement mortar
high temperature
uniaxial compression
splitting tensile
scale effect
Opis:
In this study, cubic and cylindrical cement mortar specimens were first subjected to high temperatures, then the cubic and cylindrical specimens were taken out and conducted with uniaxial compressive test and splitting tensile test, respectively. The effect of the length to side ratio on the uniaxial compressive properties and the effect of thickness-to-diameter ratio on the splitting tensile properties of cement mortar specimens after high temperature were studied. Test results show that: (1) With temperature increasing from 25 ºC (room temperature) to 400 ºC, the compressive strength and elastic modulus of cubic specimens with three kinds of side lengths decrease; the decreasing rates of compressive strength and elastic modulus of cubic specimen with side length of 70.7 mm is higher than those of cubic specimens with side length of 100 mm and 150 mm, and the strain at the peak stress of cubic specimens with three kinds of side lengths increase. (2) After the same temperature, the tensile strength of cylindrical specimen decreases with the thickness-to-diameter ratio increasing from 0.5 to 1.0. The decreasing rate of tensile strength of cylindrical specimen with thickness-to-diameter ratio is highest when the temperature is 25 ºC (room temperature), followed by that after the temperature of 200 ºC, and that after the temperature of 400 ºC is the lowest.
Źródło:
Archives of Civil Engineering; 2020, 66, 3; 139-155
1230-2945
Pojawia się w:
Archives of Civil Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effects of Polymeric Binders on the RDX-based Explosive Response Character under Slow Cook-off Conditions
Autorzy:
Yan, X.
Li, X. D.
Zhang, Y. R.
Liu, L.
Zhang, X. M.
Tan, Y. X.
Wang, H.
Wang, X. Q.
Powiązania:
https://bibliotekanauki.pl/articles/358419.pdf
Data publikacji:
2018
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Przemysłu Organicznego
Tematy:
RDX-based explosive
slow cook-off experiment
binder content
binder type
Opis:
Due to safety requirements, insensitive behaviour under slow thermal heating (cook-off) conditions is a desirable behaviour for today’s munitions. In this paper a cook-off device is designed to test two groups of RDX-based PBX explosives. In the first group the binder type was varied and in the second group the binder content of the RDX-based explosive was changed. Eleven samples were examined in order to evaluate the influence of four different binders and seven different binder contents on the shell deformation and the degree of the involved reaction. The test results showed that the degree of the reaction can be improved by changing the binder content, but not by the binder type. This phenomenon was explained by the thermal-conduction theory.
Źródło:
Central European Journal of Energetic Materials; 2018, 15, 2; 339-350
1733-7178
Pojawia się w:
Central European Journal of Energetic Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The Preparation of Soluble Cellouronic Acid Sodium Salt by 4-Acetamide-TEMPO Mediated Oxidation of Ultrasound-Pretreated Parenchyma Cellulose from Bagasse Pith
Autorzy:
Gao, X.
Chen, K.
Zhang, H.
Peng, L.
Powiązania:
https://bibliotekanauki.pl/articles/177150.pdf
Data publikacji:
2014
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
ultrasonic pretreatment
bagasse pith
parenchyma cellulose
cellouronic acid sodium salt
4-acetamide-TEMPO
Opis:
The parenchyma cellulose isolated from bagasse pith was used as an alternative resource for preparation of water-soluble cellouronic acid sodium salt (CAS). The influence of ultrasound treatment on the cellulose was investigated for obtaining CAS by regioselective oxidization using 4-acetamide-TEMPO and NaClO with NaClO2 as a primary oxidant in an aqueous buffer at pH 6.0. The yield, carboxylate content and polymerization degree (DP) of CAS were measured as a function of ultrasonic power, agitating time and cellulose consistency by an orthogonal test. The ultrasound-treated conditions were further improved by discussion of ultrasonic power, the most important factor influencing the yield and DP. An optimized CAS yield of 72.9% with DP value (DPv) of 212 was found when the ultrasonic strength is 550 W, agitating time is 3 h and cellulose consistency is 2.0%. The oxidation reactivity of cellulose was improved by ultrasonic irradiation, whereas no significant changes in crystallinity of cellulose were measured after ultrasonic treatment. Moreover, the ultrasound treatment has a greater effect on yielding CAS from parenchyma cellulose than from bagasse fibrous’ one. The CAS was further characterized by Fourier transform infrared spectroscopy (FT-IR) and Scanning electron microscopy (SEM).
Źródło:
Archives of Acoustics; 2014, 39, 2; 267-275
0137-5075
Pojawia się w:
Archives of Acoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Mechanical Properties and Fracture Analysis of Clinched Joints in Titanium Sheet Materials
Autorzy:
He, X.
Lei, L.
Zhang, Y.
Xing, B.
Powiązania:
https://bibliotekanauki.pl/articles/1030360.pdf
Data publikacji:
2017-01
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
46.70.-p
Opis:
Mechanical fastening techniques are used extensively in different industry fields for joining various materials in the assembly of components and structures. The use of mechanical clinching is of interest to different industries such as aerospace, automotive, packaging and domestic appliance. This, together with increasing use of light-weight materials, has produced a significant increase in the use of mechanical clinching in light-weight structures in recent years. This paper deals with the mechanical properties and fracture analysis of extensible die clinched joints in the dissimilar metal sheets combinations of titanium sheet material and aluminum sheet material. Tensile-shear tests were carried out to characterize the mechanical properties of different clinched joints made of the dissimilar metal sheets combinations. The normal hypothesis tests were performed to examine the rationality of the test data. The load-bearing capacity and failure modes of different titanium sheets clinched joints were studied. Results showed that most titanium sheets clinched joints failed in the neck fracture mode. Results also showed that the load-bearing capacity of clinch joints with titanium as upper sheets is higher than that of the clinched joints with titanium as lower sheets.
Źródło:
Acta Physica Polonica A; 2017, 131, 1; 16-19
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analysis of large particle sizes using a machine vision system
Autorzy:
Zhang, Z.
Yang, J.
Su, X.
Ding, L.
Powiązania:
https://bibliotekanauki.pl/articles/109404.pdf
Data publikacji:
2013
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
machine vision
particle size distribution
equivalent ellipse
best-fit rectangle
representing analysis
Opis:
Many methods based on machine vision were used to estimate coarse particles size distribution in recent years, but comparison of accuracy parameters representing particle size has not been carried out and a related representing analysis has not been yet proposed. Nine parameters were investigated. The results indicated the minor axis of equivalent ellipse and breadth of the best-fit rectangle were the most suitable for representing particle size. The former accuracy ratio was 86.43% and the latter accuracy ratio was 85.39%, while the accuracy of other parameters was less than 70%. A related representing analysis was proposed to explain this phenomenon. This research is instructive and meaningful for the size distribution estimation by machine vision.
Źródło:
Physicochemical Problems of Mineral Processing; 2013, 49, 2; 397-405
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Thermal conductivity of a Brown Earth soil as affected by biochars derived at different temperatures: Experiment and prediction with the Campbell model
Autorzy:
Zhao, B.
Li, L.
Zhao, Y.
Zhang, X.
Powiązania:
https://bibliotekanauki.pl/articles/2082959.pdf
Data publikacji:
2020
Wydawca:
Polska Akademia Nauk. Instytut Agrofizyki PAN
Tematy:
biochar
bulk density
thermal conductivity
Brown Earth soil
Campbell model
Opis:
Thermal conductivity is a significant heat transfer property of soil. However, the influence of biochar on this property is not well known. In this research, the influence of corn straw biochars prepared at 300, 500 and 700oC on the thermal conductivity of a Brown Earth (Hapli-Udic Cambisol, FAO) soil and its prediction using a Campbell model was examined. The outcomes revealed that the bulk densities of the soil markedly decreased with increases in the biochar amendment rates of 1, 3, and 5% in linear patterns. The reduction in bulk density was mainly attributed to an increase in soil porosity and organic carbon content. With increasing volumetric water contents (10, 20, 30 and 40%), the thermal conductivity of the soils significantly increased, whereas those of soils with biochar amendment were obviously less than that of the CK and the differences increased with the biochar application rates. The pyrolysis temperature of biochar exhibited a negligible effect on the bulk density and thermal conductivity of soils at large. Combining the linear reduction of bulk density with the biochar amendment rate into the Campbell model, well-fitting results for the variation inthermal conductivity versus volumetric water content were obtained and accurate values could be predicted.
Źródło:
International Agrophysics; 2020, 34, 4; 433-439
0236-8722
Pojawia się w:
International Agrophysics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A novel in-phase disposition SPWM pulse allocation strategy for cascaded H-bridge inverter
Autorzy:
Zhang, Y.
Xiong, J.
Kong, L.
Wang, X.
Powiązania:
https://bibliotekanauki.pl/articles/141155.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
in-phase disposition SPWM
Inverter
CHB
THD
Opis:
A novel in-phase disposition (IPD) SPWM pulse allocation strategy applied to a cascaded H-bridge (CHB) converter is presented in this paper. The reason causing the power of the CHB converter imbalance is analyzed according to the traditional structure, the conception of power imbalance degree is introduced and the principle of the novel in-phase disposition SPWM allocation strategy is deduced in detail. The new pulse allocation scheme can ensure the power balance in 3/4 cycles through interchanging the PWM pulse sequence of the different CHB cell, meanwhile it makes the full advantage of the IPD control strategy, lower the total harmonic distortion (THD) of line voltage compared to a carrier phase shifted (CPS) control strategy, which is verified by theoretical derivation. A seven-level cascaded inverter composed by three H-bridge cells is taken as the example. The simulation and experiment is performed. The results indicate the validity of the analysis and verify the effectiveness of the proposed SPWM allocation strategy.
Źródło:
Archives of Electrical Engineering; 2018, 67, 2; 361--375
1427-4221
2300-2506
Pojawia się w:
Archives of Electrical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analysis of vibration transfer characteristics of vehicle suspension system employing inerter
Autorzy:
Shen, Y.
Chen, L.
Liu, Y.
Zhang, X.
Powiązania:
https://bibliotekanauki.pl/articles/281766.pdf
Data publikacji:
2017
Wydawca:
Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
Tematy:
vehicle
suspension
inerter
vibration analysis
Opis:
In this paper, the force transfer mechanism of three mechanical elements “inerter, spring and damper” is analyzed based on the “force-current” analogy theory. The vibration isolation performance of the two types of simple three-element vehicle suspensions S1 (inerter is in parallel with damper) and S2 (inerter is in series with damper) are studied. The dual-mass system model of the suspensions is built by means of using the mechanical impedance method. The influence of parameters variation on vibration transfer characteristics is also investigated.
Źródło:
Journal of Theoretical and Applied Mechanics; 2017, 55, 4; 1245-1256
1429-2955
Pojawia się w:
Journal of Theoretical and Applied Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Maintenance grouping optimization for offshore wind turbine considering opportunities based on rolling horizon approach
Autorzy:
Lua, Y.
Suna, L.
Kanga, J.
Zhang, X.
Powiązania:
https://bibliotekanauki.pl/articles/260415.pdf
Data publikacji:
2018
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
offshore wind turbine
opportunistic maintenance
rolling horizon
imperfect maintenance
preventive maintenance durations
Opis:
In future, offshore wind turbines may be consider a crucial part in the supply of energy. Maintenance processes are directed to attain a safe and reliable operation of offshore machines and wind turbines. In this paper, an opportunistic maintenance strategy for offshore wind turbine is proposed, considering imperfect maintenance and the preventive maintenance durations. Reliability Centric Maintenance serves as a proactive tactic to operations and maintenance by inhibiting the possible reasons of poor performance and controlling failures. Other components can implement the opportunistic preventive maintenances if one component has reached its reliability threshold. According to the rolling horizon approach, it is of great importance to update the maintenance planning for the sake of the short-term information. By figuring out the best combination, the maintenance schedule in the mission time has been finally determined. Failure information are obtained from previous studies to accomplish the calculations. The outcomes indicate that the maintenance cost has been dramatically reduced through the application of opportunistic maintenance.
Źródło:
Polish Maritime Research; 2018, 2; 123-131
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Solution of some problems of single-scale wavelet transform processor using a magnetostatic surface wave device
Autorzy:
Lu, W.
Kuang, L.
Lü, X.
Zhu, C.
Zhang, T.
Zhang, J.
Powiązania:
https://bibliotekanauki.pl/articles/221174.pdf
Data publikacji:
2012
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
wavelet transform processor
magnetostatic surface wave (MSSW)
interdigital transducer
direct coupling
insertion loss
Opis:
In this paper, we investigate the implementation schemes of a single-scale wavelet transform processor using magnetostatic surface wave (MSSW) devices. There are three implementation schemes: the interdigital transducer, the meander line transducer and the grating transducer. Because the interdigital transducer has excellent properties, namely, good frequency characteristic and low insertion loss, we use the interdigital transducer as the implementation scheme of a single-scale wavelet transform processor using MSSW device. In the paper, we also present the solutions to the three key problems: the direct coupling between the input transducer and the output transducer, the insertion loss, and the loss characteristics of the gyromagnetic film having an influence on the wavelet transform processor. There are two methods of reducing the direct coupling between the input transducer and the output transducer: increasing the distance between the input transducer and the output transducer, and placing a metal "wall" between the input transducer and the output transducer. There also are two methods of reducing the insertion loss of a single-scale wavelet transform processor using a MSSW device for scale: the appropriate thickness of the yttrium iron garnet (YIG) film and the uniform magnetic field. The smaller the ferromagnetic resonance linewidth of the gyromagnetic film, the smaller the magnetostatic wave propagation loss.
Źródło:
Metrology and Measurement Systems; 2012, 19, 4; 685-692
0860-8229
Pojawia się w:
Metrology and Measurement Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Understanding Farmers’ Adoption Decisions for New Cash Crops: Evidence from Xishuangbanna in Tropical China
Uwarunkowania zainteresowania rolników nowymi uprawami komercyjnymi: przykład rejonu Xishuangbanna w Chinach
Autorzy:
Zhang, L.
Kono, Y.
Hua, X.
Zheng, L.
Zhou, R.
Powiązania:
https://bibliotekanauki.pl/articles/370995.pdf
Data publikacji:
2017
Wydawca:
Polska Akademia Nauk. Komitet Człowiek i Środowisko PAN
Tematy:
land use
crop choice
livelihood transition
tropical agriculture
farmland leasing
zagospodarowanie terenu
wybór uprawy
przekwalifikowywanie
rolnictwo tropikalne
leasing pól uprawnych
Opis:
On a global basis, cash cropping is usually identified as an important enterprise undertaken by farmers to increase incomes. However, the responses of farmers to these new enterprises vary greatly. Through a case study of a Dai village in Xishuangbanna, China, this paper examines how farmers make decisions about adopting new cash crops by focusing on the farm economy and land conditions. The results show that farmers did not adopt watermelons due to poor irrigation and accessibility conditions, and then they did not adopt bananas due to a transient collapse of banana market, induced by a rumor suggesting that eating bananas causes cancer. Consequently, although these non-adopters benefited from commercial exchanges with external businessmen in terms of ecological experiments and management diversification, and leasing lowlands to external businessmen is a livelihood choice that is based on the outcome of the farmer’s trade-off between profitability and risk, they missed opportunities to substantially increase incomes through cash cropping, as evidenced by the success of the farmers who adopted the cash crops. These findings suggest that the government ought to design tailored extension programs for villages, implement efficient refutation strategies to prevent rumor-induced market collapse and promote extension services as early as possible in the initial stages of transition to cash cropping.
Patrząc z perspektywy globalnej za uprawy komercyjne uznaje się istotne działania podejmowane przez rolników w celu zwiększenia swoich dochodów. Jednakże zainteresowanie rolników nowymi rozwiązaniami jest bardzo zróżnicowane. Niniejszy artykuł na przykładzie doliny Dai w należącym do Chin rejonie Xishuangbanna pokazuje jakie czynniki finansowe i środowiskowe wpływają na podjęcie przez rolników decyzji odnoszących się do nowych upraw komercyjnych. Otrzymane wyniki pokazują, że za odrzuceniem arbuzów stały ograniczone możliwości nawadniania i ograniczony dostęp, a za odrzuceniem bananów chwilowe załamanie rynku zbytu tych owoców, związane z szerzącą się pogłoską, jakoby konsumpcja bananów mogło być przyczyną nowotworów.Konsekwentnie, chociaż rolnicy odrzucający nowe uprawy korzystali z wymiany handlowej z zewnętrznymi przedsiębiorcami pod kątem eksperymentów ekologicznych i dywersyfikacji zarządzania, a ponadto biorąc pod uwagę, że przeznaczanie pól dla zewnętrznych przedsiębiorców jest decyzją opartą na ocenie możliwych zysków i strat, ci rolnicy stracili szansę na znaczące zwiększenie przychodów z upraw komercyjnych. Pokazuje to przykład rolników, którzy jednak zdecydowali się na nowe uprawy. Uzyskane rezultatu wskazują, że rząd powinien przygotować dostosowane do potrzeb rolników programy i strategie odnoszące się do tych zagadnień.
Źródło:
Problemy Ekorozwoju; 2017, 12, 2; 99-108
1895-6912
Pojawia się w:
Problemy Ekorozwoju
Dostawca treści:
Biblioteka Nauki
Artykuł
Wyświetlanie 16-30 z 85

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