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Tytuł:
A model of degree of scattering polarization for oil spilling
Autorzy:
Wang, Xiao
Xu, Jiang
Qian, Weixian
Ouyang, Jingyi
Powiązania:
https://bibliotekanauki.pl/articles/1835805.pdf
Data publikacji:
2020
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
optical mechanism
surface microstructure
degree of scattering polarization
Fresnel formula
oil slick
Opis:
Oil slicks often show uncertain surface roughness and Fresnel reflection parameters. Consequently, differentiating oil spilled on the seawater in these areas using optical sensors is a challenge. Therefore, the optical mechanism of the oil film has been studied by the Maxwell equation. It is found that the polarization characteristics of the oil slicks can help us to overcome this problem. According to the Fresnel formula, the scattering coefficient and scattering rate of the homogeneous oil film have been deduced, and the phase difference of the scattering electromagnetic wave has also been calculated to verify the accuracy of the model. The parameter, a degree of scattering polarization, has been derived to identify the oil slicks on the sea wave. It depends on accurately knowing the Stokes parameter for the reflected light, and varies with the refractive index of the surface layer and viewing angles. The actual spilled oil has been measured by this model, and the oil film can be accurately identified at various angles. These preliminary results suggest that the potential of multi-angle polarization measurement of ocean surface needs further researches.
Źródło:
Optica Applicata; 2020, 50, 3; 433-445
0078-5466
1899-7015
Pojawia się w:
Optica Applicata
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Research on Yarn Diameter and Unevenness Based on an Adaptive Median Filter Denoising Algorithm
Badanie średnicy i nierówności przędzy w oparciu o algorytm odszumiania z adaptacyjnym filtrem medianowym (AMF)
Autorzy:
Wang, Xiao
Hou, Ru-Meng
Gao, Xiao-Yan
Xin, Bin-Jie
Powiązania:
https://bibliotekanauki.pl/articles/231681.pdf
Data publikacji:
2020
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Biopolimerów i Włókien Chemicznych
Tematy:
adaptive median filtering
algorithm
denoising
yarn diameter
unevenness
image processing
adaptacyjny filtr medianowy
algorytm
odszumianie
średnica przędzy
nierówności
przetwarzanie obrazu
Opis:
In this paper an adaptive median filtering denoising algorithm is proposed to measure yarn diameter and its unevenness. Images of nine different yarn samples were captured using one set of a self-developed yarn image acquisition system. Image separation of the background and yarn sections was conducted using a combination of adaptive median filtering, adaptive threshold segmentation and morphological processing. The noise-free yarn image was used for diameter detection of the subsequent yarn image and the discrimination of the yarn unevenness. Experimental results show that the testing data of yarn unevenness detection based on the adaptive median filter denoising algorithm is very consistent with the data using the traditional method. It is proved that the yarn detection method proposed, based on an adaptive median filter denoising algorithm, is feasible. It can be used to calculate yarn diameter accurately and measure yarn unevenness efficiently, so as to determine the quality of yarn appearance objectively.
W artykule zaproponowano algorytm odszumiania z adaptacyjnym filtrem medianowym (AMF) do pomiaru średnicy przędzy i jej nierówności. Obrazy dziewięciu różnych próbek przędzy zostały przechwycone przy użyciu jednego zestawu samodzielnie opracowanego systemu akwizycji obrazów przędzy. Rozdzielenie obrazu tła i odcinków przędzy przeprowadzono przy użyciu kombinacji AMF, adaptacyjnej segmentacji progowej i przetwarzania morfologicznego. Bezszumowy obraz przędzy wykorzystano do wykrywania średnicy przędzy i rozróżnienia nierówności przędzy. Wyniki eksperymentalne pokazały, że dane testowe dotyczące wykrywania nierówności przędzy w oparciu o zaproponowany algorytm miały wysoką zgodność z danymi uzyskanymi przy użyciu tradycyjnej metody. Algorytmu tego można użyć do dokładnego obliczenia średnicy przędzy i skutecznego pomiaru nierówności przędzy, aby obiektywnie określić jakość wyglądu przędzy.
Źródło:
Fibres & Textiles in Eastern Europe; 2020, 1 (139); 36-41
1230-3666
2300-7354
Pojawia się w:
Fibres & Textiles in Eastern Europe
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Combined effects of NQO1 Pro187Ser or SULT1A1 Arg213His polymorphism and smoking on bladder cancer risk: Two meta-analyses
Autorzy:
Wang, Xiao-Chun
Wang, Jian
Tao, Hui-Hui
Zhang, Chao
Xu, Li-Fa
Powiązania:
https://bibliotekanauki.pl/articles/2161894.pdf
Data publikacji:
2017-07-14
Wydawca:
Instytut Medycyny Pracy im. prof. dra Jerzego Nofera w Łodzi
Tematy:
polymorphisms
meta-analysis
NQO1
urinary bladder neoplasms
smoking
SULT1A1
Opis:
Objectives Objectives: Cigarette smoking is the major risk factor of bladder cancer via exposure to chemical carcinogens. Nicotinamide adenine dinucleotide phosphate (NADP+): quinine oxidoreductase 1 (NQO1) and sulfotransferase 1A1 (SULT1A1) have been reported to involve in the metabolism of polycyclic aromatic hydrocarbons (PAHs) and aromatic amines. Therefore, the risk of bladder cancer (BC) may be influenced by polymorphisms in the genes that modulate metabolic detoxification in particular by interacting with cigarette smoking. Considering the limited power by the individual studies with a relatively small sample size, especially when analyzing the combined effect of polymorphisms in NQO1 and SULT1A1 genes and smoking, these 2 meta-analyses have aimed to clarify the combined effects of them on BC risk by integrating related studies. Material and Methods Two meta-analyses included 1341 cases and 1346 controls concerning NQO1 Pro187Ser and smoking, and 1921 cases and 1882 controls on SULT1A1 Arg213His and smoking were performed. Odds ratios (OR) and 95% confidence intervals (CI) were used for assessing the strength of the association. Results The result has demonstrated that smokers with NQO1 Pro/Ser or Ser/Ser genotypes have a prominent association with the risk of BC as compared with non-smokers with NQO1 Pro/Pro genotype, with OR equal to 3.71 (95% CI: 2.87–4.78, $ \text{p}_\text{heterogeneity} $ = 0.376). Besides, smokers carrying SULT1A1 Arg/Arg genotypes were observed to confer 2.38 fold increased risk of BC (95% CI: 1.44–3.93, $ \text{p}_\text{heterogeneity} $ = 0.001) when compared with non-smokers with SULT1A1 Arg/Arg or His/His genotypes. Conclusions These findings have suggested that the NQO1 Pro187Ser or SULT1A1 Arg213His polymorphism combination with smoking significantly confer susceptibility to BC. Int J Occup Med Environ Health 2017;30(5):791–802
Źródło:
International Journal of Occupational Medicine and Environmental Health; 2017, 30, 5; 791-802
1232-1087
1896-494X
Pojawia się w:
International Journal of Occupational Medicine and Environmental Health
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Feasibility study on preparation of magnesium titanate in carbonthermic reduction of vanadium titanomagnetite concentrates
Autorzy:
Chen, Chao
Sun, Ti-Chang
Kou, Jue
Wang, Xiao-Ping
Zhao, Yong-Qiang
Powiązania:
https://bibliotekanauki.pl/articles/110181.pdf
Data publikacji:
2019
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
vanadium titanomagnetite
carbonthermic reduction
magnesium titanate
formation mechanism
Opis:
Effect of temperature and Mg:Ti ratio on phase composition and microstructure of reduced pellets was investigated to verify the feasibility of preparation of magnesium titanate by adding MgO in carbonthermic reduction of the vanadium titanomagnetite concentrates (VTC). Thermodynamic analysis results showed that magnesium titanate is more easily generated than FeTi2O5 or TiO2 by the reaction of FeTiO3 and MgO under the reductive atmosphere, which was confirmed by the discovery of magnesium titanate at roast experiment. It was found that the optimum conditions for reduction of VTC pellets were temperature of 1250 ºC and Mg:Ti ratio of 2, and the main phases of reduction product were metallic Fe and magnesium titanate (Mg2TiO4). However, trace iron impurities in Mg2TiO4 particles were found by energy-dispersive spectroscopy (EDS), so further purification is required.
Źródło:
Physicochemical Problems of Mineral Processing; 2019, 55, 2; 417-425
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Evolution of hierarchical structure and spatial pattern of coastal cities in China – based on the data of distribution of marine-related enterprises
Autorzy:
Wang, L.
Xiao, W.
Wang, C.
Powiązania:
https://bibliotekanauki.pl/articles/258846.pdf
Data publikacji:
2017
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
hierarchical structure
spatial pattern
city network
Opis:
In this paper, a comprehensive research of the evolution of the hierarchical structure and spatial pattern of coastal cities in China was conducted based on the data of distribution of the headquarters and subsidiaries of marine-related enterprises in 1995, 2005 and 2015 using the city network research method proposed by Taylor. The results of the empirical research showed: China’s coastal city network had an obvious hierarchical characteristics of “national coastal cityregional coastal city-sub-regional coastal city-local coastal city”, in the 20 years of development process, the hierarchies of coastal cities in China showed a hierarchical progressive evolution; in past 20 years, the spatial pattern and network structure of coastal cities in China tended to be complete, and the city network was more uniform, forming a “three tiers and three urban agglomerations” network structure; the strength of connection among the cities was obviously strengthened, and the efficiency of urban spatial connection was improved overall.
Źródło:
Polish Maritime Research; 2017, S 3; 58-64
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Research on optimum design method of cushion thickness in composite foundation under rigid base
Autorzy:
Xiao, Yaoting
Wang, Jing
Powiązania:
https://bibliotekanauki.pl/articles/27312123.pdf
Data publikacji:
2023
Wydawca:
Polska Akademia Nauk. Czasopisma i Monografie PAN
Tematy:
fundament kompozytowy
grubość
konstrukcja optymalna
rozkład naprężeń
composite foundation
cushion thickness
optimum design
stress diffusion
Opis:
At present, the cushion thickness of composite foundation under rigid base is mostly selected by the experience of the engineer, which is of great arbitrariness. In order to improve this problem, the optimum design method of cushion thickness is proposed by theoretical research. First, the stress diffusion line in the cushion is assumed to be a quadratic curve, and the critical diffusion thickness of the pile top stress is obtained. Then, by analyzing the relative deformation between soil and pile, pile top penetration into the critical cushion thickness is proposed. Finally, based on the relationship between stress ratio of pile to soil and cushion thickness, the calculation method of optimum cushion thickness is put forward. The application of engineering cases shows that the proposed method has better calculation results, which attests to the correctness of the method. The method can be used for the optimal design of cushion thickness of single-type-pile or multi-type-pile composite foundation.
Źródło:
Archives of Civil Engineering; 2023, 69, 2; 471--482
1230-2945
Pojawia się w:
Archives of Civil Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Marine industrial cluster structure and its coupling relationship with urban development: a case of Shandong province
Autorzy:
Xiao, W.
Zhao, B.
Wang, L.
Powiązania:
https://bibliotekanauki.pl/articles/259796.pdf
Data publikacji:
2016
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
marine industry
industrial cluster
urban development
coupling coordination model
Opis:
Marine economy is a new economic form, emphasizing new development concept, new operation mechanism and management mode. In recent years, marine economy shows rapid growth, and marine industry presents a clustering development trend. The industrial linkage effect, industrial agglomeration effect and industrial radiation effect of the marine industrial cluster are important motive forces for the development of coastal cities. The marine industrial cluster takes coastal cities as the development platform and space, while the coastal cities achieve rapid and sustainable development based on the marine industrial cluster. The synergetic and coupling development of the marine industrial cluster and coastal cities is an important way for the promotion of industrial competitiveness and urban competitiveness. This paper developed a measure to identify the marine industrial cluster, designed the evaluation index of coupling of marine industrial cluster and coastal cities development from two perspectives of industrial linkage and spatial agglomeration, taking Shandong province, a typical coastal province in China, as an example, it studied the situation of the marine industrial cluster based on input-output data and data of marine enterprises of coastal cities, based on which it explored the coupling relationship between marine industrial cluster and coastal cities of Shandong province.
Źródło:
Polish Maritime Research; 2016, S 1; 115-122
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Study of flotation behavior and mechanism of cervantite activation by copper ions
Autorzy:
Wang, J.
Wang, Y.
Fu, K.
Xu, L.
Wang, Z.
Sun, H.
Xiao, J.
Powiązania:
https://bibliotekanauki.pl/articles/110228.pdf
Data publikacji:
2018
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
flotation
cervantite
copper ions
activation mechanism
Opis:
Copper-ion activation plays a highly important role in cervantite (Sb2O4) flotation. Without metal-ion activation, cervantite cannot be floated by sodium oleate. In this study, flotation tests were conducted to study the effect of Cu2+ on the flotation behaviours of cervantite and quartz (SiO2) as the main gangue mineral. Metal-ion adsorption capacities, zeta potentials, solution chemistry and X-ray photoelectron spectra were analyzed to study the adsorption behavior and mechanism of copper ions and sodium oleate interaction with the minerals surfaces. The results demonstrate that under weakly acidic conditions, cervantite can be flotated and separated from quartz by the addition of copper ions. The reason is that copper ions can be selectively adsorbed on the cervantite surface under weakly acidic conditions, thereby promoting the adsorption of sodium oleate onto the cervantite surface by chemical adsorption. Conversely, copper ions are weakly adsorbed on quartz surfaces below pH 6.1, and sodium oleate cannot be adsorbed on quartz surfaces by chemical adsorption. The hydroxy copper species are integral to the selective activation of cervantite over quartz.
Źródło:
Physicochemical Problems of Mineral Processing; 2018, 54, 3; 814-825
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Horse - Expert: an aided expert system for diagnosing horse diseases
Autorzy:
Qin, H.
Xiao, J.
Gao, X.
Wang, H.
Powiązania:
https://bibliotekanauki.pl/articles/31506.pdf
Data publikacji:
2016
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Opis:
In contrast to the rapid development of the horse husbandry in China, the ability of horse veterinarians to diagnose diseases has not been improved and only a few domain experts have considerable expertise. At present, many expert systems have been developed for diseases diagnosis, but few for horse diseases diagnosis have been studied in depth. This paper presents the design and development of a computer-aided expert system for diagnosing horse diseases. We suggest an approach for diagnosis of horse diseases based on the analysis of diagnostic characteristics and the experiential knowledge of domain experts. It is based on using evidence-weighted uncertainty reasoning theory, which is a combination of evidence theory and an uncertainty pass algorithm of confidence factors. It enables drawing of inferences with atypical clinical signs and the uncertainty of the user’s subjective understanding. It reduces the influence of subjective factors on diagnostic accuracy. The system utilizes a user friendly interface for users and requests a confidence factor from users when feedback is given to the system. Horse-Expert combines the confidence factors with weight factors assigned to clinical signs by experts during the knowledge acquisition process to make diagnostic conclusions. The system can diagnose 91 common horse diseases, and provides suggestions for appropriate treatment options. In addition, users can check the medical record through statistical charts. The system has been tested in seven demonstration areas of Xinjiang province in northwestern China. By constantly maintaining and updating the knowledge base, the system has potential application in veterinary practice.
Źródło:
Polish Journal of Veterinary Sciences; 2016, 19, 4
1505-1773
Pojawia się w:
Polish Journal of Veterinary Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Assessing system impedance based on data regrouping
Autorzy:
Xu, Shuangting
Xiao, Xianyong
Wang, Yang
Wu, Jun
Powiązania:
https://bibliotekanauki.pl/articles/1848954.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
system impedance
passive method
Thevenin equivalent
power system
Opis:
In recent years, assessing supply system impedance has become crucial due to the concerns on power quality and the proliferation of distributed generators. In this paper, a novel method is shown for passive measurement of system impedances using the gapless waveform data collected by a portable power quality monitoring device. This method improves the overall measurement accuracy through data regrouping. Compared with the traditional methods that use the consecutive measurement data directly, the proposed method regroups the data to find better candidates with less flotation on the system side. Simulation studies and extensive field tests have been conducted to verify the effectiveness of the proposed method. The results indicate that the proposed method can serve as a useful tool for impedance measurement tasks performed by utility companies.
Źródło:
Metrology and Measurement Systems; 2021, 28, 1; 191-208
0860-8229
Pojawia się w:
Metrology and Measurement Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
An adaptive k nearest neighbour method for imputation of missing traffic data based on two similarity metrics
Autorzy:
Wang, Yang
Xiao, Yu
Lai, Jianhui
Chen, Yanyan
Powiązania:
https://bibliotekanauki.pl/articles/949848.pdf
Data publikacji:
2020
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
missing traffic data
similarity metrics
K-nearest neighbour method
stochastic characteristics
metoda porównywania danych
metryki podobieństwa
metoda najbliższego sąsiada
cechy stochastyczne
Opis:
Traffic flow is one of the fundamental parameters for traffic analysis and planning. With the rapid development of intelligent transportation systems, a large number of various detectors have been deployed in urban roads and, consequently, huge amount of data relating to the traffic flow are accumulatively available now. However, the traffic flow data detected through various detectors are often degraded due to the presence of a number of missing data, which can even lead to erroneous analysis and decision if no appropriate process is carried out. To remedy this issue, great research efforts have been made and subsequently various imputation techniques have been successively proposed in recent years, among which the k nearest neighbour algorithm (kNN) has received a great popularity as it is easy to implement and impute the missing data effectively. In the work presented in this paper, we firstly analyse the stochastic effect of traffic flow, to which the suffering of the kNN algorithm can be attributed. This motivates us to make an improvement, while eliminating the requirement to predefine parameters. Such a parameter-free algorithm has been realized by introducing a new similarity metric which is combined with the conventional metric so as to avoid the parameter setting, which is often determined with the requirement of adequate domain knowledge. Unlike the conventional version of the kNN algorithm, the proposed algorithm employs the multivariate linear regression model to estimate the weights for the final output, based on a set of data, which is smoothed by a Wavelet technique. A series of experiments have been performed, based on a set of traffic flow data reported from serval different countries, to examine the adaptive determination of parameters and the smoothing effect. Additional experiments have been conducted to evaluate the competent performance for the proposed algorithm by comparing to a number of widely-used imputing algorithms.
Źródło:
Archives of Transport; 2020, 54, 2; 59-73
0866-9546
2300-8830
Pojawia się w:
Archives of Transport
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Research on information content of light field on the image plane illuminated by incoherent light source
Autorzy:
Cai, Xiao-ou
Lai, Xian-jing
Wang, Hui
Powiązania:
https://bibliotekanauki.pl/articles/173681.pdf
Data publikacji:
2019
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
information content
mutual intention
degree of freedom
coherent wavelet source
independent coherent signal
Opis:
A novel approach for the measurement of information content of light field on the image plane illuminated by an incoherent light source has been proposed according to Shannon’s information theory. We put forward a hypothetical concept named "coherent wavelet source" on an incoherent light source which can form an independent coherent signal on the object surface based on the expression of mutual intensity on the object surface. As a result, the number of independent coherent signals on the object surface can be made out by dividing the whole illumination source on a coherent wavelet source size. Meanwhile, the maximum number of degree of freedom of light field which can reach the image plane is given based on the structure of imaging system. Concrete algorithm for the information content of the imaging light illuminated by a 1D linear light source and a 2D circular light source are presented.
Źródło:
Optica Applicata; 2019, 49, 2; 265-273
0078-5466
1899-7015
Pojawia się w:
Optica Applicata
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Finite element analysis of bipolar plate stamping based on a Yld2000 yield model
Autorzy:
Wang, Wenyao
Xiao, Yao
Guo, Nan
Min, Junying
Powiązania:
https://bibliotekanauki.pl/articles/29520081.pdf
Data publikacji:
2022
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Wydawnictwo AGH
Tematy:
finite element analysis
bipolar plate
yield model
stamping
Opis:
Finite element analysis is an essential means for bipolar plate design and the optimization of the manufacturing process. However, the accuracy of the finite element simulation is significantly affected by the constitutive model, especially the yield model. In this paper, uniaxial and biaxial tensile tests were conducted to obtain the yield loci of an ultra-thin austenite stainless steel. The Yld2000 yield model was calibrated using the yield loci under different equivalent plastic strains. The microchannel stamping experiment and its finite element simulations were conducted to study the effect of yield model parameters on the finite element simulation of bipolar plate stamping. The results show that the simulation with Yld2000 calibrated by 0.004 and 0.05 equivalent plastic strain has the best prediction accuracy for the microchannel springback and thickness distribution, respectively.
Źródło:
Computer Methods in Materials Science; 2022, 22, 1; 7-12
2720-4081
2720-3948
Pojawia się w:
Computer Methods in Materials Science
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A novel test case prioritization method based on problems of numerical software code statement defect prediction
Nowatorska metoda priorytetyzacji przypadków testowych oparta na prognozowaniu błędów instrukcji kodu oprogramowania numerycznego
Autorzy:
Shao, Yuanxun
Liu, Bin
Wang, Shihai
Xiao, Peng
Powiązania:
https://bibliotekanauki.pl/articles/1841862.pdf
Data publikacji:
2020
Wydawca:
Polska Akademia Nauk. Polskie Naukowo-Techniczne Towarzystwo Eksploatacyjne PAN
Tematy:
software defect prediction
test case prioritization
code statement metrics
machine learning
software testing
przewidywanie błędów oprogramowania
priorytetyzacja przypadków testowych
metryki instrukcji kodu
uczenie maszynowe
testowanie oprogramowania
Opis:
Test case prioritization (TCP) has been considerably utilized to arrange the implementation order of test cases, which contributes to improve the efficiency and resource allocation of software regression testing. Traditional coverage-based TCP techniques, such as statement-level, method/function-level and class-level, only leverages program code coverage to prioritize test cases without considering the probable distribution of defects. However, software defect data tends to be imbalanced following Pareto principle. Instinctively, the more vulnerable the code covered by the test case is, the higher the priority it is. Besides, statement-level coverage is a more fine-grained method than function-level coverage or class-level coverage, which can more accurately formulate test strategies. Therefore, we present a test case prioritization approach based on statement software defect prediction to tame the limitations of current coverage-based techniques in this paper. Statement metrics in the source code are extracted and data pre-processing is implemented to train the defect predictor. And then the defect detection rate of test cases is calculated by combining the prioritization strategy and prediction results. Finally, the prioritization performance is evaluated in terms of average percentage faults detected in four open source datasets. We comprehensively compare the performance of the proposed method under different prioritization strategies and predictors. The experimental results show it is a promising technique to improve the prevailing coverage-based TCP methods by incorporating statement-level defect-proneness. Moreover, it is also concluded that the performance of the additional strategy is better than that of max and total, and the choice of the defect predictor affects the efficiency of the strategy.
Metodę priorytetyzacji przypadków testowych (TCP) wykorzystuje się powszechnie do ustalania kolejności implementacji przypadków testowych, co przyczynia się do poprawy wydajności i alokacji zasobów w trakcie testowania regresyjnego oprogramowania. Tradycyjne techniki TCP oparte na pokryciu na poziomie instrukcji, metody/funkcji oraz klasy, wykorzystują pokrycie kodu programu tylko w celu ustalenia priorytetów przypadków testowych, bez uwzględnienia prawdopodobnego rozkładu błędów. Jednak dane o błędach oprogramowania są zwykle niezrównoważone zgodnie z zasadą Pareto. Instynktownie, im bardziej wrażliwy jest kod pokryty przypadkiem testowym, tym wyższy jest jego priorytet. Poza tym, pokrycie na poziomie instrukcji jest bardziej szczegółową metodą niż pokrycie na poziomie funkcji lub pokrycie na poziomie klasy, które mogą dokładniej formułować strategie testowe. Dlatego w artykule przedstawiamy podejście do priorytetyzacji przypadków testowych oparte na prognozowaniu błędów instrukcji oprogramowania, które pozwala zmniejszyć ograniczenia obecnych technik opartych na pokryciu. Wyodrębniono metryki instrukcji w kodzie źródłowym i zaimplementowano wstępne przetwarzanie danych w celu nauczania predyktora błędów. Następnie obliczono wskaźnik wykrywania błędów w przypadkach testowych poprzez połączenie strategii priorytetyzacji i wyników prognozowania. Wreszcie, oceniono wydajność ustalania priorytetów pod względem średnich procentowych błędów wykrytych w czterech zestawach danych typu open source. Kompleksowo porównano wydajność proponowanej metody w ramach różnych strategii ustalania priorytetów i predyktorów. Wyniki eksperymentów pokazują, że jest to obiecująca technika poprawy dominujących metod TCP opartych na pokryciu poprzez włączenie podatności na błędy na poziomie instrukcji. Ponadto stwierdzono również, że strategia dodatkowa cechuje się lepszą wydajnością niż strategie max i total, a wybór predyktora błędów wpływa na skuteczność strategii.
Źródło:
Eksploatacja i Niezawodność; 2020, 22, 3; 419-431
1507-2711
Pojawia się w:
Eksploatacja i Niezawodność
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Assessing system impedance based on data regrouping
Autorzy:
Xu, Shuangting
Xiao, Xianyong
Wang, Yang
Wu, Jun
Powiązania:
https://bibliotekanauki.pl/articles/1848965.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
system impedance
passive method
Thevenin equivalent
power system
Opis:
In recent years, assessing supply system impedance has become crucial due to the concerns on power quality and the proliferation of distributed generators. In this paper, a novel method is shown for passive measurement of system impedances using the gapless waveform data collected by a portable power quality monitoring device. This method improves the overall measurement accuracy through data regrouping. Compared with the traditional methods that use the consecutive measurement data directly, the proposed method regroups the data to find better candidates with less flotation on the system side. Simulation studies and extensive field tests have been conducted to verify the effectiveness of the proposed method. The results indicate that the proposed method can serve as a useful tool for impedance measurement tasks performed by utility companies.
Źródło:
Metrology and Measurement Systems; 2021, 28, 1; 191-208
0860-8229
Pojawia się w:
Metrology and Measurement Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Wyświetlanie 1-15 z 50

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