Wyniki wyszukiwania - Biblioteka Nauki

1

An Interval-Valued Intuitionistic Fuzzy Rough Set Model

100%

Zhang Z.

Fundamenta Informaticae

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2009

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tom Vol. 97, nr 4

471-498

EN

Given a widespread interest in rough sets as being applied to various tasks of data analysis it is not surprising at all that we have witnessed a wave of further generalizations and algorithmic enhancements of this original concept. This paper proposes an interval-valued intuitionistic fuzzy rough model by means of integrating the classical Pawlak rough set theory with the interval-valued intuitionistic fuzzy set theory. Firstly, some concepts and properties of interval-valued intuitionistic fuzzy set and interval-valued intuitionistic fuzzy relation are introduced. Secondly, a pair of lower and upper interval-valued intuitionistic fuzzy rough approximation operators induced from an interval-valued intuitionistic fuzzy relation is defined, and some properties of approximation operators are investigated in detail. Furthermore, by introducing cut sets of interval-valued intuitionistic fuzzy sets, classical representations of interval-valued intuitionistic fuzzy rough approximation operators are presented. Finally, the connections between special interval-valued intuitionistic fuzzy relations and interval-valued intuitionistic fuzzy rough approximation operators are constructed, and the relationships of this model and the others rough set models are also examined.

2

Arbuscular mycorrhizal Glomus versiforme induced bioprotection of apple tree against scar skin disease

71%

Yang S. , Zhang Z. , Zhang Z. , Shi S.

Acta Scientiarum Polonorum. Hortorum Cultus

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2014

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tom 13

|

nr 5

EN

Apple scar skin viroid (ASSVd) is a serious pathogen of apple fruits that results in severe loss in apple production. Up to nowadays, many ASSVd management options are applied to resist the disease, but the diserable resulits are not achieved. Therefore, this study was conducted in 2010–2012 at experimental field of Penglai City, Shandong Province, China (E 120°57’22’’, N 370°38’33’’) to investigate whether arbuscular mycorrhizal (AM) Glomus versiforme protects Red Fuji apple trees (Malus × domestica Borkh) against apple scar skin viroid. Red Fuji apple trees were inoculated with Glomus versiforme and then potential protection mechanism was explored and compared to noninoculated plants. The results showed that inoculation with Glomus versiforme significantly increased root length colonization rate and clearly decreased the percentage of disease severity of apple scar skin disease. Compared to non-inoculated plants, Glomus versiforme obviously enhanced total nitrogen and phosphorus concentrations in leaves. Root colonization by Glomus versiforme induced an increase in defense-related enzyme activities in fruits, such as the enhanced activities of catalase, ascorbate peroxidase, chitinase and glucanase. Significant differences in acid content of fruit and fruit yield were observed as apple roots were colonized by Glomus versiforme. It is therefore concluded that Glomus versiforme can be regarded as a biocontrol agent to protect apple trees against the infection with ASSVd.

PL

Wiroid bliznowatości skórki jabłek (ASSVd) jest poważnym patogenem jabłek powodującym znaczne straty w ich produkcji. Obecnie stosuje się wiele opcji kontrolowania ASSVd w celu uzyskania odporności na chorobę, ale nie osiągnięto jeszcze pożądanych rezultatów. Niniejsze badanie przeprowadzono w latach 2010–2012 na polu doświadczalnym miasta Penglai, prowincja Shandong w Chinach (E 120°57’22”, N 370°38’33”) w celu zbadania, czy mikoryza abuskularna (AM) Glomus versiforme chroni jabłonie Red Fuji (Malus × domestica Borkh) przed wiroidem bliznowatości skórki jabłek. Jabłonie Red Fuji zaszczepiono Glomus versiforme a następnie badano mechanizm potencjalnej ochrony oraz porównano go z roślinami nieszczepionymi. Wykazano, że inokulacja Glomus versiforme istotnie zwiększyła szybkość kolonizacji korzeni oraz wyrażnie zmniejszyła procent ostrej choroby bliznowatości skórki jabłek. W porównaniu z roślinami nieszczepionymi, Glomus versiforme wyrażnie wzmagał stężenia całkowitego azotu i fosforu w liściach. Kolonizacja korzeni przez Glomus versiforme powodowała wzrost aktywności enzymatycznej związanej z mechanizmem obronnym, np. wzmożoną aktywność katalazy, peroksydazy askorbinianowej, chitynazy oraz glukanazy. Zaobserwowano istotne różnice w zawartości kwasów oraz plonie owoców w miarę kolonizowania korzeni jabłoni przez Glomus versiforme. Można więc wyciągnąć wniosek, że Glomus versiforme może być uważany za czynnik bio-kontroli chroniący jabłonie przed zakażeniem ASSVd.

3

Reliability modeling and maintenance optimization of the diesel system in locomotives

71%

Zhang Z. , Gao W. , Zhou Y. , Zhang Z.

Eksploatacja i Niezawodność

|

2012

|

tom Vol. 14, No. 4

302-311

EN

Engine system is a prone-fault part in diesel locomotive and its malfunctions always occur regularly in different seasons in practice. However, the current maintenance policy in China has not attached deserving importance to seasonal influence, which is considered as one of the main causes for over/under-maintenance. To assess the current maintenance, in this study a double-fold Weibull competing risk model for summer and winter is developed using the real failure data (2008-2011) of locomotives from Urumqi Railway Bureau. Meanwhile, a new approach, termed as Approximately Combined Parameter Method (ACPM), is proposed to combine the initially estimated parameters into different folds, which can avoid a subjective determination of the model's parameters fold. After that, the combined parameters are used as initial values for maximum likelihood estimate (MLE) to achieve an accurate model. Necessary optimizations are introduced based on the chosen models. Results show that the maintenance period differs a lot between winter and summer, and the optimized maintenance can increase the availability and decrease cost more than the existing Policy.

PL

Układ silnikowy stanowi podatną na uszkodzenia część lokomotywy spalinowej, a w praktyce jego awarie występują zawsze regularnie w zależności od pory roku. Pomimo tego, obecna polityka obsługowa w Chinach nie przywiązuje wystarczającej wagi do wpływu pór roku, co uważa się za główną przyczynę nadmiernych lub niedostatecznych działań obsługowych. Aby ocenić bieżące działania obsługowe, w niniejszym artykule opracowano model zagrożeń konkurujących dla lata i zimy, oparty na połączeniu dwóch rozkładów Weibulla, wykorzystujący rzeczywiste dane o uszkodzeniach (2009-2011) lokomotyw używanych przez Agencję Kolejową Urumqui. Jednocześnie zaproponowano nowe podejście, o nazwie Approximately Combined Parameter Method (Metoda Przybliżonego Łączenia Parametrów, ACPM), które polega na łączeniu wstępnie obliczonych parametrów w różne wielokrotności, co pozwala na uniknięcie subiektywnego wyznaczania liczby parametrów modelu. W celu otrzymania dokładnego modelu, połączone parametry wykorzystuje się jako wstępne wartości w estymacji metodą największej wiarygodności. Konieczne optymalizacje wprowadza się na podstawie wybranych modeli. Wyniki pokazują, że letni okres obsługowy różni się zasadniczo od zimowego, a zoptymalizowana obsługa może zwiększyć gotowość systemu i zmniejszyć koszty utrzymania ruchu w większym stopniu niż dotychczasowa polityka obsługowa.

4

Probing energy-related CO2 emissions in the Beijing-Tianjin-Hebei region based on ridge regression considering population factors

63%

Wen L. , Zhang Z.

Polish Journal of Environmental Studies

|

2020

|

tom 29

|

nr 3

5

On minimax inequality and generalized quasi-variational inequality in h-spaces

63%

Wu X. , Zhang Z.

Journal of Applied Analysis

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1999

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tom Vol. 5, nr 1

59-70

EN

In this paper, we give a new minimax theorem and two new existence theorems of solutions for generalized quasi-variational inequalities in H-spaces. Our results improve and develop some famous results.

6

Optimal maintenance of a series production system with two multi-component subsystems and an intermediate buffer

63%

Zhou Y. , Zhang Z.

Eksploatacja i Niezawodność

|

2015

|

tom Vol. 17, no. 2

314--325

EN

Intermediate buffers often exist in practical production systems to reduce the influence of the breakdown and maintenance ef subsystems on system production. At the same time, the effects of intermediate buffers also make the degradation process of the system more difficult to model. Some existing papers investigate the performance evaluation and maintenance optimisation of a production system with intermediate buffers under a predetermined maintenance strategy structure. However, only few papers pay attention to the property of the optimal maintenance strategy structure. This paper develops a method based on the Markov decision process to identify the optimal maintenance strategy for a series-parallel system with two multi-component subsystems and an intermediate buffer. The structure of the obtained optimal maintenance strategy is analysed, which shows that the optimal strategy structure cannot be modelled by a limited number of parameters. However, some useful properties of the strategy structure are obtained, which can simplify the maintenance optimisation. Another interesting finding is that a large buffer capacity cannot always bring about high average revenue even through the cost of holding an item in the buffer is much smaller than the production revenue per item.

PL

W systemach produkcyjnych często stosuje się bufory pośrednie w celu zmniejszenia wpływu awarii i konserwacji podsystemów na system produkcji. Jednocześnie, oddziaływanie buforów pośrednich utrudnia modelowanie procesu degradacji systemu. Istnieją badania dotyczące oceny funkcjonowania i optymalizacji utrzymania systemów produkcyjnych wykorzystujących bufory pośrednie przy założeniu wcześniej określonej struktury strategii utrzymania ruchy. Jednak tylko nieliczne prace zwracają uwagę na własności optymalnej struktury strategii utrzymania ruchu. W przedstawionej pracy opracowano opartą na procesie decyzyjnym Markowa metodę określania optymalnej strategii utrzymania ruchu dla układu szeregowo-równoległego z dwoma podsystemami wieloskładnikowymi oraz buforem pośrednim. Przeanalizowano strukturę otrzymanej optymalnej strategii utrzymania i wykazano, że struktury takiej nie można zamodelować przy użyciu ograniczonej liczby parametrów. Jednak odkryto pewne przydatne właściwości struktury strategii, które mogą ułatwić optymalizację utrzymania ruchu. Innym interesującym odkryciem było to, że duża pojemność bufora nie zawsze daje wysoką średnią przychodów mimo iż koszty przechowywania obiektu w buforze są znacznie mniejsze niż przychody z produkcji w przeliczeniu na jeden obiekt.

7

Predicting spatial distribution of plant functional traits in a forest-steppe zone

63%

Fan S. , Zhang Z.

Polish Journal of Ecology

|

2021

|

tom 69

|

nr 1

8

Dispersal of wood mice and bank voles in an agricultural landscape

63%

Zhang Z. , Usher M. B.

Acta Theriologica

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1991

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tom 36

|

nr 3-4

9

Influence of operational sex ratio and density on the copulatory behaviour and mating system of Brandt's vole Microtus brandti

63%

Zhang J. , Zhang Z.

Acta Theriologica

|

2003

|

tom 48

|

nr 3

EN

The pattern of copulatory behaviour of Brandt's vole Microtus brandti (Radde, 1861) is similar to patterns 11 and 12 as described by Dewsbury and Dixson: no lock, single intromission, thrusting after intromission and multiple ejaculations. Under constant density, when the operational sex ratio (OSR, male to female) was skewed to the males, the mating opportunity of males decreased due to mating interference, while the mating input of female remained the same; when the OSR was skewed to the females, male voles tended to increase mating input while females did not. Under the same OSR (1:1), when density increased, the mating opportunity of both sexes dramatically decreased due to mating interference between same sex individuals; the thrusting frequency of males increased, probably due to compensation for the decreased mating opportunity. There was a considerable probability of the voles forming monogamous and polygynous mating relationships. Our results did not support the prediction that when OSR is skewed to male, the mating interval of males will shorten. We suggest that the most predominant mating system and mating interference should be taken into account when investigating an OSR effect. Our study suggested that the Brandt's vole is prone predominantly to monogamy and polygyny. However, due to limitation of observation in the laboratory, further work should be combined with studies in the field.

10

Food hoarding behaviour of large field mouse Apodemus peninsulae

63%

Lu J. , Zhang Z.

Acta Theriologica

|

2005

|

tom 50

|

nr 1

EN

An important behavioural adaptation for animal species with variable or unpredictable food availability is storing food. Food availability for large field mouseApodemus peninsulae (Thomas, 1907) is not reliable. We conducted a series of tests with the large field mouse to determine food hoarding behaviour, response when their hoarded food was removed, and whether perishable foods were treated different than non perishable foods. The study was conducted in four semi-natural enclosures (4 × 3 × 1 m), established on the Donglingshan Mountain near Beijing, China. Thirteen large field mice were placed in enclosures and offered wild apricotPrunus armeniaca seeds and Liaodong oakQuercus liaotungensis acorns. Our results indicated that although large field mice hoarded seeds in larder and scatter patterns, they more frequently exhibited larder hoarding. Liadong oak acorns were generally consumed near the feeder, whereas apricot seeds were more frequently transported to the nest box. Only apricot seeds were scattered among hoard sites. When seeds were removed from hoarding sites the mice responded by taking increased amounts of seeds to their nest for larder and scatter hoarding. Hoarding sites were not randomly distributed throughout the enclosure.

11

Soil organic carbon density spatial distribution and influencing factors in a karst mountainous basin

51%

Zhang Z. , Zhou Y. , Wang S. , Huang X.

Polish Journal of Environmental Studies

|

2017

|

tom 26

|

nr 5

EN

To illustrate the distribution pattern of soil organic carbon density (SOCD) in a small karst watershed and its main influencing factors, this research quantitatively analyzed the spatial heterogeneity and distribution characteristics of SOCD using 2,755 thoroughly investigated soil profile samples; field point sampling, laboratory determination, and geo-statistical analysis were used, and the major influencing factors of SOCD were analyzed using a principal components analysis. The results indicated that the SOCD decreased gradually with increasing soil depth in the small karst watershed; in particular, the average SOCD was equal to 12.11 kg·m⁻² at a depth of 100 cm, which is higher than the national level. An optimal fitting model for the SOCD in this Basin was a Gaussian model, which showed a moderately strong spatial correlation. A kriging interpolation suggested that the soil carbon density (SOCD) was higher in the eastern region but lower in the southern region, exhibiting an ascending trend from the middle to the exterior. In the small karst watershed, the SOCD at a depth of 100 cm differs between different vegetation types, different soil utilization types, and different soil types. The soil thickness, rock coverage and altitude were the principal influencing factors on the SOCD in the small karst watershed, among which soil thickness had the largest impact.

12

Numerical simulation of stress-relief effects of protective layer extraction

51%

Jia T. , Zhang Z. , Tang C. , Zhang Y.

Archives of Mining Sciences

|

2013

|

tom Vol. 58, no. 2

521--540

EN

Field test and laboratory analog model test on the stress-relief effects of protective layer extraction are time-consuming and laborious. In this paper, on the basis of full consideration of rock heterogeinity and in combination with gas geology at Pingdingshan Mine 5, a numerical model was estalished with the gas-solid coupling rock failure process analysis system RFPA-Gas to simulate the stress variation law, roof and floor deformation, fracture evolution law, displacement in the protected seam, change in gas permeability and gas migration law during protective layer extraction. The simulation results repoduced stress variations in coal and rock strata, roof and floor deformation and fracture evolution process during protective layer extraction. The movement of rock strata were characterized by upper three zones and lower two zones: caving zone, fracture zone and bending subsidence zone in the vertical direction in the overlying strata; floor deformation and failure zone and elasto-plastic deformation zone in the vertical direction in the underlying strata. It showed that stress relief occurred in the protected seam, which led to vertical and horizontal displacements, significant increase in gas permeability, gas desorption and migration. Hence, the outburst threat in the protected seam was eliminated. Meanwhile, with comprehensive analysis of variaition of stress state, deformation characteristics and fracture distribution in coal seam and with consideration of changes in gas leakage rate, gas pressure and permeability, according to gas leakage rate, the floor strata of the protecive layer were divided into four leakage zones. They corresponded to four zones with different stress states and fracture development: original leakage zone - slow reducing leakage zone - dramatic increasing leakage zone- steady increasing leakage zone. This classification provides a clear direction for gas control in the protective layer. The simulation results are in good agreement with the stress-relief effects in field.

PL

Badania terenowe oraz modelowanie w warunkach laboratoryjnych skutków odprężenia warstwy zabezpieczającej w trakcie wydobycia są niezwykle czasochłonne i skomplikowane. Uwzględniając niejednorodność skał i wykorzystując dane geologiczne i o obecności gazów w kopalni Pindingshan 5, opracowano model numeryczny pękania skał w układzie gaz-ciało stałe w oparciu o analizę układu RFPA-Gaz. Model wykorzystano do symulacji zmian naprężeń, odkształceń stropu i spągu, propagacji pęknięć, przemieszczeń w pokładach zabezpieczonych, zmian w przepuszczalności gazów oraz migracji gazów w trakcie wybierania warstwy zabezpieczającej. Wyniki symulacji odwzorowują zmiany naprężeń, odkształceń stropu i spągu, propagacji pęknięć w trakcie wybierania warstwy ochronnej. Ruchy warstw górotworu scharakteryzowano poprzez analizę trzech stref nadkładu i dwóch stref lezących poniżej: w warstwach nadkładu: strefy zawału, strefy spękań oraz strefy osiadania (przemieszczenia w kierunku pionowym), w warstwach leżących poniżej: strefy odkształcenia i pękania spągu, oraz strefy odkształceń elastyczno- plastycznych w kierunku pionowym. Wykazano, że odprężanie miało miejsce w pokładzie zabezpieczającym, co prowadziło do powstania przemieszczeń pionowych oraz poziomych, zanotowano także znaczny wzrost przepuszczalności gazów, desorpcji gazów oraz ich transportu. Z tych względów zagrożenie wybuchem w pokładzie ochronnym zostało wyeliminowane. Całościowa analiza zmian stanu naprężenia, charakterystyki odkształceń i rozkładu pęknięć w pokładzie węgla przeprowadzona została dla czterech stref przecieku gazów, wydzielonych w oparciu zmiany natężenia wypływu gazów, ciśnienia gazów oraz przepuszczalności w odniesieniu do natężenia przepływu gazu w spągu w warstwie ochronnej. Te cztery strefy odpowiadały czterem strefom w których zanotowano odmienne stany naprężeń i rozkładu spękań: pierwotna strefa wycieku, powoli zmniejszająca się strefa wycieku, gramatycznie powiększająca się strefa wycieku i stopniowo powiększająca się strefa wycieku. Powyższa klasyfikacja dostarcza wyraźnych wytycznych dla prowadzenia kontroli wycieku gazu w warstwach ochronnych. Wyniki symulacji skutków odprężania wykazują dużą zgodność z wynikami badań terenowych.

13

On String Languages Generated by Sequential Numerical P Systems

51%

Zhang Z. , Wu T. , Pan L.

Fundamenta Informaticae

|

2016

|

tom Vol. 145, nr 4

485--509

EN

Numerical P systems are a class of P systems inspired both from the structure of living cells and from economics. In this work, we further investigate the generative capacity of numerical P systems as language generators. The families of languages generated by non-enzymatic, by enzymatic, and by purely enzymatic (all programs are enzymatic) numerical P systems working in the sequential mode are compared with the language families in the Chomsky hierarchy. Especially, a characterization of recursively enumerable languages is obtained by using purely enzymatic numerical P systems working in the sequential mode.

14

Numerical analysis of one-dimensional nonlinear acoustic wave

51%

Zheng H. , Morozov I. B. , Zhang Z.

Acta Geophysica

|

2007

|

tom Vol. 55, no. 3

313-323

EN

Numerical investigations on one-dimensional nonlinear acoustic wave with third and fourth order nonlinearities are presented using high-order finite-difference (HFD) operators with a simple flux-limiter (SFL) algorithm. As shown by our nu-merical tests, the HFDSFL method is able to produce more stable, accurate and conservative solutions to the nonlinear acoustic waves than those computed by finite-difference combined with the flux-corrected-transport algorithm. Unlike the linear acoustic waves, the nonlinear acoustic waves have variable phase velocity and waveform both in time-space (t-x) domain and frequency-wavenumber (f-k) domain; of our special interest is the behaviour during the propagation of nonlinear acoustic waves: the waveforms are strongly linked to the type of medium nonlinearities, generation of harmonics, frequency and wavenumber peak shifts. In seismic sense, these characteristics of nonlinear wave will introduce new issues during such seismic processing as Normal Moveout and f-k filter. Moreover, as shown by our numerical experiment for a four-layer model, the nonlinearities of media will introduce extra velocity errors in seismic velocity inversion.

15

On String Languages Generated by Spiking Neural P Systems with Astrocytes

51%

Kong Y. , Zhang Z. , Liu Y.

Fundamenta Informaticae

|

2015

|

tom Vol. 136, nr 3

231--240

EN

Spiking neural P systems with astrocytes (SNPA systems, for short) are a class of distributed parallel computing devices inspired from the way spikes pass along the synapses between neurons. In this work, we investigate the computational power of SNPA systems as language generators. Specifically, representations of recursively enumerable languages and of regular languages are given by means of SNPA systems without forgetting rules. Furthermore, a simple finite language is produced which can be generated by SNPA systems, while it cannot be generated by usual spiking neural P systems. These results show that the astrocytes are a powerful ingredient for spiking neural P systems as language generators.

16

Dynamic Characteristic Analysis of a Rotor System with Rub-impact Fault Considering Rotor-stator Misalignment

51%

Ma H. , Tai X. , Zhang Z. , Wen B.

Przegląd Elektrotechniczny

|

2012

|

tom R. 88, nr 9b

145-149

EN

In this paper, taking a single span flexible rotor system with two discs as the research object, the finite element model of the rotor-bearing system is established. The stator is simplified as a group of equispaced points along the circumference and the rotor as a point based on the contact dynamic theory. The rotor-stator rubbing is simulated using multiple point-point contact elements, the separation and the contact of the rotor and stator are determined by the change of the cylindrical gap, and the rotor and stator model are coupled by nonlinear contact force. By adopting the augmented Lagrangian method to deal with contact constraint conditions, Coulomb friction model to simulate rotor-stator frictional characteristics, the responses of the rotor system with rubbing are analyzed. The effects of rotating speeds and rubbing stiffness on normal rubbing forces are discussed under asymmetrical rotor-stator clearance conditions. The results show that there may be different rubbing forms (local rubbing and full rubbing) and transient impact forces under four cases with rotating speeds. Rubbing stiffness has the greatest effects on the rubbing force, the amount of misalignment affects mainly the transient impact force and does not affect the normal rubbing force at the stable rubbing stage.

PL

Analizowano układ wirnika z dwoma dyskami. Symulowano tarcie między wirnikiem i stojanem a separacja była uwzględniana jako zmiana cylindrycznej szczeliny.

17

Synthesis, Crystal Structure and Properties of Tetra(piperidinium)bis(ethanolate) Decavanadate

51%

Li Y. , Sun F. , Wu Z. , Zhang Z.

Polish Journal of Chemistry

|

2007

|

tom Vol. 81, nr 8

1379-1386

EN

The title compound, [(C5H12N)4][V10O26(OC2H5)2] consisting of a [V10O26(OC2H5)2]4– polyanion and four protonated piperidinium [C5H12N]+ was synthesized and characterized by elemental analyses, spectroscopic (IR, UV-vis and ESR) studies and single-crystal X-ray diffraction. It crystallizes in the monoclinic system, space group P21/n and Z = 2, with a = 10.628(2) capital A, ring ,b = 12.983(2) capital A, ring , c = 16.160(3) capital A, ring , and beta = 90.74(3). Least-squares refinement gave a final R factor of 0.0559 for 4024 unique reflections having I >2sigma(I). A three-dimensional supramolecular arrangement of the polyanion and piperidinium cations in the crystal lattice is generated by hydrogen bonds. In contrast with other anionic decavanadates, there are two ethoxy groups bridging the outmost vanadium atoms in the title compound. The coordinated nature of the ethoxy-bridge is the first example among the reported decavanadates. The cyclic voltammetry behaviour of the compound is preliminarily investigated.

18

Determination of pumped storage capacity combining the entropy weighting method and principal component analysis

51%

Zhang Z. , Cai X. , Parkun D.

Journal of Power Technologies

|

2014

|

tom Vol. 94, nr 3

165--175

EN

The aim of the study is to evaluate methods for determining appropriate pumped storage capacities. This is especially relevant, since pumped storage units are, today, viewed as some of the best means of storing large amounts intermittently-produced power in order to meet peak demands on power supply grids. The determination of appropriate pumped storage capacity is a problem of integrated decision-making. The entropy weighting method and principal component analysis are combined to determine the optimum pumped storage capacity, taking into account several representative indices, whilst using the syntropy method to standardize the data indicators. The entropy weighting method is used to determine the weighting of the indicators, while principal component analysis offers reduction of the dimensions. The optimal solution is then determined by ranking the evaluation values for each design. This method can avoid subjectivity in the weighting assignment and simplifies the calculations to an evaluation problem which contains multiple evaluation indices. Using the principle of energy-saving scheduling, the peak-shaving method is applied to the dispatching over a typical daily load in order to verify the rationality of the calculated pumped storage capacity. The example analysis, here, shows that it is reasonable to determine the optimum pumped storage capacity by using this combination of the entropy weighting method and principal component analysis.

19

Optimal Placement of Traveling Wave Fault Location Equipment in Power Grid Based on Characteristic Non-singular Set

51%

Tang J. , Yin X. , Zhang Z. , Qi X.

Przegląd Elektrotechniczny

|

2013

|

tom R. 89, nr 5

30-35

EN

With the widely use of traveling wave fault location equipment (TWFLE) in power grid, network-based traveling wave fault location (NBTWFL) method has been proposed. To ensure the effectiveness and economy of NBTWFL method, based on the principle of characteristic nonsingular set, an optimal placement algorithm of TWFLE is proposed in this paper. The corresponding NBTWFL method based on maximum nonsingular subset, additional installation plan of TWFLE and some other related problems are also discussed in this paper.

PL

W artykule opisano metodą wykrywania awarii w sieci elektroenergetycznej na podstawie analizy fali wędrującej. Proponowane rozwiązanie bazuje na klasycznym algorytmie wykrywania fali wędrującej, w którym zastosowano niesingularne wartości własne. Pozwoliło to na optymalizację rozmieszczenia urządzeń do wykrywania awarii.

20

Resource reuse of waste-activated sludge as raw material of microbial flocculant preparation: methods and comparison

51%

Zhang Z. , Zhang J. , Xia S.

Polish Journal of Environmental Studies

|

2013

|

tom 22

|

nr 3

EN

Resource reuse of waste-activated sludge (WAS) from a municipal wastewater treatment plant (WWTP) was introduced as raw material of microbial flocculant (MBF) preparation. With WAS samples of three concentrations, MBF preparation by various methods – including cation exchange resin (CER), CER-ultrasonication, CER-ultrasonication-CER, ultrasonication, ultrasonication-CER, and ultrasonication-CER-ultrasonication methods – were comparatively investigated. According to the results of chemical compositions, concentrations, and flocculating activities of the prepared MBFs, the compound methods excelled the sole methods, and the CER-ultrasonication method was the best. Major compositions of the prepared MBFs contained polysaccharides, proteins, and nucleic acids. Improving sludge concentration was beneficial to extract MBF in high concentrations using the above methods. Appropriate MBF mass dosage was crucial its flocculating activity because less or more dosage would deteriorate the flocculation. The mechanism analysis indicated that CER treatment could provide a good pretreatment for ultrasonication, but became useless when it was set after ultrasonication.