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Tytuł:
Product promotional strategies on a Chinese shopping website: The multimodal fusion model
Strategie promocji produktów na stronie chińskiego sklepu internetowego: model fuzji multimodalnej
Autorzy:
Chen, Li-Chi
Hertsiuk, Khrystyna
Powiązania:
https://bibliotekanauki.pl/articles/1789344.pdf
Data publikacji:
2021-03-16
Wydawca:
Uniwersytet Gdański. Wydawnictwo Uniwersytetu Gdańskiego
Opis:
Zakupy online, jako forma elektronicznego handlu, pozwalają kupującym na bezpośredni zakup produktu lub usługi od sprzedawcy bądź sklepu internetowego za pomocą przeglądarki internetowej. W artykule porównano sto reklam ubrań z chińskiego portalu zakupowego Taobao (taobao.com), zawierających obraz/obrazy oraz tekst, co miało na celu ukazanie i wyjaśnienie, jak sprzedawcy i sklepy internetowe reklamują swoje produkty. Za analityczną ramę posłużył model fuzji multimodalnej, w którym łączą się tryby konceptualne, wizualne i werbalne. Dokonując analizy danych, zaobserwowano cztery strategie lingwistyczne używane przez sprzedawców na Taobao w celu promocji produktów. Są to: 1) wyrażanie bliskości i solidarności z obecnymi i przyszłymi klientami; 2) odwoływanie się do poczucia humoru; 3) sugerowanie korzyści wynikłych z zakupu produktu; oraz 4) podkreślanie zalet produktu. W celu wyrażenia bliskości i solidarności z obecnymi i przyszłymi klientami używane są zaimki osobowe oraz pytania. Humor tworzony jest za pomocą epizodyzacji i neologizmów. Aby zasugerować korzyści wynikające z zakupu, sprzedawcy stosują implikacje i neologizmy. Zaobserwowano także, że sprzedawcy, aby podkreślić zalety produktu, stosują metafory, asercję oraz pośredniość.
Źródło:
Gdańskie Studia Azji Wschodniej; 2021, 19; 132-151
2353-8724
Pojawia się w:
Gdańskie Studia Azji Wschodniej
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A fault location strategy based on information fusion and CODAS algorithm under epistemic uncertainty
Autorzy:
Duan, Rongxing
Chen, Li
He, Jiejun
Huang, Shujuan
Powiązania:
https://bibliotekanauki.pl/articles/2172032.pdf
Data publikacji:
2022
Wydawca:
Polska Akademia Nauk. Polskie Naukowo-Techniczne Towarzystwo Eksploatacyjne PAN
Tematy:
fault tree
expert evaluation
evidence network
information fusion
CODAS algorithm
Opis:
Application of new technology in modern systems not only substantially improves the performance, but also presents a severe challenge to fault location of these systems. This paper presents a new fault location strategy for maintenance personnel to recover them based on information fusion and improved CODAS algorithm. Firstly, a fault tree is adopted to develop the failure model of a complex system, and failure probability of components is determined by expert evaluations to handle the uncertainty problem. Moreover, a fault tree is converted into an evidence network to obtain importance degrees, which are used to construct a diagnostic decision table together with the risk priority number. Additionally, these results are updated to optimize the maintenance process using sensor information. A novel dynamic location strategy is designed based on interval CODAS algorithm and optimal fault location strategy can be obtained. Finally, a real system is analyzed to demonstrate the feasibility of the proposed maintenance strategy.
Źródło:
Eksploatacja i Niezawodność; 2022, 24, 3; 478--488
1507-2711
Pojawia się w:
Eksploatacja i Niezawodność
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Noether Theorems and Discrete Variational Integrators in Field Theory
Autorzy:
Xia, Li-Li
Chen, Li-Qun
Liu, Chang-Xin
Powiązania:
https://bibliotekanauki.pl/articles/1398640.pdf
Data publikacji:
2015-03
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
02.20.Sv
11.30.-j
Opis:
The discrete analogue of the Noether-type identities in field theory is investigated by means of the difference discrete variational principle in which the difference is regarded as an entire geometric object. The discrete counterparts of the Noether theorems are obtained. It is proved that there exists the discrete version of the Noether conservation law in field theory. The discretization for the nonlinear Schrödinger equation is presented to illustrate the results.
Źródło:
Acta Physica Polonica A; 2015, 127, 3; 669-673
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Wit and Humor in Chinese Characters - A Socio-Cultural and Historical Perspective
Elementy humorystyczne w znakach chińskich – perspektywa społeczno-kulturowa i historyczna
Autorzy:
Chen, Li-Chi
Sroka-Grądziel, Anna
Lee, Fu-Lan
Hajndrych, Eryk
Powiązania:
https://bibliotekanauki.pl/articles/1968943.pdf
Data publikacji:
2021-12-31
Wydawca:
Polska Akademia Nauk. Instytut Języka Polskiego PAN
Tematy:
Chinese characters
Chinese ligatures
homophonic puns
human behavior
humor
znaki chińskie
chińskie ligatury
homofoniczne gry słowne
zachowanie ludzkie
Opis:
Building on Bergson’s ([1911] 2014) account of laughter, as well as two recognized functions of Chinese humor – 寓教於樂 ‘wrapping instructions in entertainment/amusement’ (Liao 2001) and 會心微笑 ‘a hearty laugh or a knowing smile’ (Chen 2017) – this study intends to analyze the wit and humor found in Chinese characters from a socio-cultural and historical perspective. The data used in this analysis come from internet resources and books, as well as from the authors’ linguistic repertoire. We have observed six sources of humor in Chinese characters. These are: (a) the visual form of a Chinese character; (b) decomposing a Chinese character; (c) Chinese ligatures; (d) Chinese homophonic puns; (e) misreading of similar Chinese characters; and (f) the borrowing of Japanese kanji. Our findings suggest that funny Chinese characters should contain human behavioral attributes and wrapped instructions and will evoke a hearty laugh or knowing smile from the in-group members of a Chinese-speaking community.
Celem artykułu jest ukazanie elementów humorystycznych zawartych w znakach chińskich w perspektywie społeczno-kulturowej i historycznej. Podjęta analiza opiera się na definicji śmiechu sformułowanej przez Bergsona ([1911] 2014) oraz dwóch funkcjach chińskiego humoru – 寓教於樂 tzw. ‘zawieranie morału w rozrywce’ (Liao 2001) oraz 會心微笑 tzw. ‘szczery śmiech lub wymowny uśmiech’ (L.-C. Chen 2017). Materiał badawczy wykorzystany w badaniu pochodzi z różnorodnych źródeł internetowych i literackich, oraz z repertuaru językowego autorów. Badanie pozwoliło na wyróżnienie sześciu źródeł humoru zawartego w znakach chińskich: (a) formy wizualne znaków; (b) dekompozycja znaków; (c) chińskie ligatury; (d) chińskie gry słów na bazie homofonów; (e) błędne odczytywania podobnych znaków; oraz (f) zapożyczenia z kanji – znaków chińskich używanych w języku japońskim. Wyniki pracy sugerują, że humorystyczność poszczególnych znaków wiąże się z posiadaniem ludzkich cech behawioralnych i ukrytych pouczeń, które to prowadzą do wywołania w odbiorcy będącego członkiem społeczności chińskojęzycznej ‘szczerego śmiechu lub wymownego uśmiechu’.
Źródło:
Socjolingwistyka; 2021, 35; 41-54
0208-6808
Pojawia się w:
Socjolingwistyka
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effective sensor placement based on a VIKOR method considering common cause failure in the presence of epistemic uncertainty
Autorzy:
Duan, Rong-Xing
He, Jie-Jun
Feng, Tao
Huang, Shu-Juan
Chen, Li
Powiązania:
https://bibliotekanauki.pl/articles/1841697.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Polskie Naukowo-Techniczne Towarzystwo Eksploatacyjne PAN
Tematy:
dynamic fault tree
epistemic uncertainty
sensor placement
reliability criterion
diagnostic sensor model
Opis:
Owing to expensive cost and restricted structure, limited sensors are allowed to install in modern systems to monitor the working state, which can improve their availability. Therefore, an effective sensor placement method is presented based on a VIKOR algorithm considering common cause failure (CCF) under epistemic uncertainty in this paper. Specifically, a dynamic fault tree (DFT) is developed to build a fault model to simulate dynamic fault behaviors and some reliability indices are calculated using a dynamic evidence network (DEN). Furthermore, a VIKOR method is proposed to choose the possible sensor locations based on these indices. Besides, a sensor model is introduced by using a priority AND gate (PAND) to describe the failure sequence between a sensor and a component. All placement schemes can be enumerated when the number of sensors is given, and the largest system reliability is the best alternative among the placement schemes. Finally, a case study shows that CCF has some influence on sensor placement and cannot be neglected in the reliabilitybased sensor placement.
Źródło:
Eksploatacja i Niezawodność; 2021, 23, 2; 253-262
1507-2711
Pojawia się w:
Eksploatacja i Niezawodność
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Dynamic performance and stability analysis of an active inerter-based suspension with time-delayed acceleration feedback control
Autorzy:
Wang, Yong
Jin, Xian-Yu
Zhang, Yun-Shun
Ding, Hu
Chen, Li-Qun
Powiązania:
https://bibliotekanauki.pl/articles/2173651.pdf
Data publikacji:
2022
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
active inerter-based suspension
acceleration feedback control
dynamic performance
stability analysis
time delay
kontrola sprzężenia zwrotnego przyspieszenia
wydajność dynamiczna
aktywne zawieszenie na bazie inertera
analiza stabilności
opóźnienie
Opis:
An active inerter-based suspension with acceleration feedback control is proposed in this paper, the time delay generated in the controllers and actuators is considered, which constitutes the time-delayed active inerter-based (TDA-IB) suspension. The dynamic equation of the TDA-IB suspension is established and is a neutral type of delay differential equation (NDDE) in which the time delay exists in the highestorder derivative. The stability analysis is conducted by calculating the number of unstable characteristic roots based on the definite integral stability method, the stable and unstable regions are determined. The effect of time delay and feedback gain on the dynamic performance of the TDA-IB suspension under harmonic, random, and shock excitations is studied in detail and compared with the parallel-connected inerterbased (PC-IB) and traditional suspensions. The results show that the TDA-IB suspension is asymptotically stable for smaller feedback gain and time delay, through increasing the feedback gain, the stable regions shrink, and a smaller time delay could cause the system to become unstable. Furthermore, the time delay could regulate the resonance peak around the unsprung mass natural frequency and generate multiple high-frequency resonance peaks. If the time delay is chosen appropriately and falls into the stable range, the TDA-IB suspension could improve the dynamic performance for the suspension stroke and dynamic tire load while having a deterioration for the vehicle body acceleration compared with the PC-IB and traditional suspensions.
Źródło:
Bulletin of the Polish Academy of Sciences. Technical Sciences; 2022, 70, 2; art. no. e140687
0239-7528
Pojawia się w:
Bulletin of the Polish Academy of Sciences. Technical Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Diffraction mechanism of five-port transmission gratings
Autorzy:
Gao, Chenhao
Wang, Bo
Wen, Kunhua
Meng, Ziming
Wang, Qu
Nie, Zhaogang
Xing, Xiangjun
Chen, Li
Lei, Liang
Zhou, Jinyun
Powiązania:
https://bibliotekanauki.pl/articles/1835817.pdf
Data publikacji:
2020
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
1 × 5 splitting
single-groove grating
normal incidence
Opis:
This paper designs a five-port transmission grating under normal incidence. Rigorous coupled-wave approach is used to optimize the grating parameters. The energy of the grating is mainly dispersed to the 0th, ±1st and ±2nd orders. The efficiency of each diffraction order under both polarizations is close to 20%. The modal method is used to describe the propagation mechanism of the two polarized lights in the grating, and the diffraction behavior of the grating is analyzed. In addition, the grating has a wide range of incident characteristics and a large process tolerance. Therefore, this five-port beam splitter with a connecting layer will be a good polarization-independent beam splitting device.
Źródło:
Optica Applicata; 2020, 50, 4; 609-618
0078-5466
1899-7015
Pojawia się w:
Optica Applicata
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Generation of three-port splitter by double-layer grating in second-order Littrow configuration
Autorzy:
Gao, Chenhao
Wang, Bo
Fu, Chen
Fang, Jimin
Wen, Kunhua
Meng, Ziming
Nie, Zhaogang
Xing, Xiangjun
Chen, Li
Lei, Liang
Zhou, Jinyun
Powiązania:
https://bibliotekanauki.pl/articles/174662.pdf
Data publikacji:
2020
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
three-port splitter
second-order Littrow
double-layer grating
Opis:
In this paper, a novel double-layer three-port grating is described. The incident grating structure is in the second-order Littrow configuration. The grating region is composed of fused silica and Ta2O5.The designed grating beam splitter has high efficiency under TE polarization and TM polarization, respectively. The efficiency of two polarizations is more than 90%. In addition, compared with a single-layer three-port grating, this new beam splitter has good fabrication tolerance and incident bandwidth. Therefore, the optimized structure has a good application value.
Źródło:
Optica Applicata; 2020, 50, 2; 271-280
0078-5466
1899-7015
Pojawia się w:
Optica Applicata
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
On choosability of complete multipartite graphs $K_{4,3*t,2*(k-2t-2),1*(t+1)}$
Autorzy:
Zheng, Guo-Ping
Shen, Yu-Fa
Chen, Zuo-Li
Lv, Jin-Feng
Powiązania:
https://bibliotekanauki.pl/articles/744583.pdf
Data publikacji:
2010
Wydawca:
Uniwersytet Zielonogórski. Wydział Matematyki, Informatyki i Ekonometrii
Tematy:
list coloring
complete multipartite graphs
chromatic-choosable graphs
Ohba's conjecture
Opis:
A graph G is said to be chromatic-choosable if ch(G) = χ(G). Ohba has conjectured that every graph G with 2χ(G)+1 or fewer vertices is chromatic-choosable. It is clear that Ohba's conjecture is true if and only if it is true for complete multipartite graphs. In this paper we show that Ohba's conjecture is true for complete multipartite graphs $K_{4,3*t,2*(k-2t-2),1*(t+1)}$ for all integers t ≥ 1 and k ≥ 2t+2, that is, $ch(K_{4,3*t,2*(k-2t-2),1*(t+1)}) = k$, which extends the results $ch(K_{4,3,2*(k-4),1*2}) = k$ given by Shen et al. (Discrete Math. 308 (2008) 136-143), and $ch(K_{4,3*2,2*(k-6),1*3}) = k$ given by He et al. (Discrete Math. 308 (2008) 5871-5877).
Źródło:
Discussiones Mathematicae Graph Theory; 2010, 30, 2; 237-244
2083-5892
Pojawia się w:
Discussiones Mathematicae Graph Theory
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
La ponctuation dans quelques imprimés de Galliot du Pré
The punctuation in Galliot du Pré’s printed works
Autorzy:
LI, Huei-Chen
Powiązania:
https://bibliotekanauki.pl/articles/676213.pdf
Data publikacji:
2017
Wydawca:
Uniwersytet Łódzki. Wydawnictwo Uniwersytetu Łódzkiego
Tematy:
Galliot du Pré
ponctuation à la Renaissance
Rés. Y2-72 (Ysaie le Triste)
Rés. Y2-31 (Roman de Perceforest)
Rés. Y2-74 (Perceval le Galloys en prose)
punctuation of the sixteenth century
Ysaie le Triste
Perceforest
Perceval le Galloys in prose
Opis:
According to Annie Charon-Parent, Galliot du Pré, bookseller-publisher of the 16th century, published 330 editions during his career between 1521-1561. These editions relate essentially to the law, the literature, the history, the religion, the sciences, and the geography. As we know that the primary function of punctuation is to make the text clearer and more understandable, it also helps the silent reader to identify the sense of sentences and the structure of the text, this function of clarifying the text suits the humanist needs. Nevertheless, in comparison with the variability of the medieval punctuation, with the advent of the printing press, is the punctuation of the Renaissance more stable than the medieval punctuation? Does the Renaissance punctuation respect the rules recommended by medieval and Renaissance treaties? Our study, based on three Galliot du Pré’s printed works between 1522-1530, kept all in the National Library of France (Res. Y2-72; Res. Y2-31; Res. Y2-74), aims at presenting the practices of each printed work in order to clear up Galliot du Pré's sub-system.
D’après Annie Charon-Parent, Galliot du Pré, libraire-éditeur du XVIe siècle, publie 330 éditions durant sa carrière, entre 1521 et 1561. Elles touchent essentiellement le droit, la littérature, l’histoire, la religion, les sciences, ainsi que la géographie. Comme nous le savons bien, la ponctuation a pour principale fonction de rendre le texte plus intelligible et d’aider le lecteur à repérer le sens des phrases et la structure du texte : cette fonction de rendre le texte clair répond parfaitement au goût des humanistes. Pourtant, face à l’anarchie et à la variabilité de la ponctuation médiévale, la pratique de la ponctuation renaissante, avec l’avènement de l’imprimerie, est-elle plus stable que celle du Moyen Âge ? Respecte-elle les règles recommandées par les traités médiévaux ou ceux de l’époque ? Notre étude, basée sur trois imprimés de Galliot du Pré parus entre 1522 et 1530, tous conservés à la BNF (Rés. Y2-72 ; Rés. Y2-31 ; Rés. Y2-74), vise à présenter les pratiques de chaque imprimé afin de mettre au clair le sous-système de Galliot du Pré, un homme de la Renaissance.
Źródło:
e-Scripta Romanica; 2017, 4; 62-79
2392-0718
Pojawia się w:
e-Scripta Romanica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Correlation analysis and prevention of electrocution risk factors in the construction industry
Autorzy:
Li, Jue
Chen, Feifei
Li, Shije
Powiązania:
https://bibliotekanauki.pl/articles/2174084.pdf
Data publikacji:
2022
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Opis:
Electrocution is one of the main causes of workplace deaths in the construction industry. This paper presents a framework for identifying electrocution risk factors and exploring the correlations between them, with the aim of assisting accident prevention research. Specifically, the Haddon Matrix is used to extract the risk factors from 193 investigation reports of electrical shock accidents from 2012-2019, and the Apriori algorithm is applied to examine the potential relationships between these factors. Based on association rules using three criteria: support(S), confidence(C) and lift(L), the betweenness centrality is then introduced to optimize association rules and find the most important rules though comparison. The results show that after optimization, some of these critical rules rise significantly in rank, such as Workplace: indoor → No CPR provided. Through these ranking changes, the focus of safety management is clarified, and finally, based on a comprehensive analysis of association rules, targeted accident prevention measures are suggested.
Źródło:
Archives of Civil Engineering; 2022, 68, 4; 537--554
1230-2945
Pojawia się w:
Archives of Civil Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Linear List Coloring of Some Sparse Graphs
Autorzy:
Chen, Ming
Li, Yusheng
Zhang, Li
Powiązania:
https://bibliotekanauki.pl/articles/32083756.pdf
Data publikacji:
2021-02-01
Wydawca:
Uniwersytet Zielonogórski. Wydział Matematyki, Informatyki i Ekonometrii
Tematy:
linear coloring
maximum average degree
planar graphs
discharging
Opis:
A linear $k$-coloring of a graph is a proper $k$-coloring of the graph such that any subgraph induced by the vertices of any pair of color classes is a union of vertex-disjoint paths. A graph $G$ is linearly $L$-colorable if there is a linear coloring $c$ of $G$ for a given list assignment $L = \{L(v) : v ∈ V(G)\}$ such that $c(v) ∈ L(v)$ for all $v ∈ V(G)$, and $G$ is linearly $k$-choosable if $G$ is linearly $L$-colorable for any list assignment with $|L(v)| ≥ k$. The smallest integer $k$ such that $G$ is linearly $k$-choosable is called the linear list chromatic number, denoted by $lc_l(G)$. It is clear that \(lc_l(G)≥\Big\lceil\frac{\Delta(G)}{1}\Big\rceil+1\) for any graph $G$ with maximum degree $\Delta(G)$. The maximum average degree of a graph $G$, denoted by $mad(G)$, is the maximum of the average degrees of all subgraphs of $G$. In this note, we shall prove the following. Let $G$ be a graph, (1) if $mad(G)<\frac{8}{3}$ and $\Delta(G) ≥ 7$, then \(lc_l(G)=\Big\lceil\frac{\Delta(G)}{2}\Big\rceil+1\); (2) if $mad(G)<{18}{7}$ and $\Delta(G) ≥ 5$, then \(lc_l(G)=\Big\lceil\frac{\Delta(G)}{2}\Big\rceil+1\); (3) if $mad(G)<{20}{7}$ and $\Delta(G) ≥ 5$, then \(lc_l(G)≤\Big\lceil\frac{\Delta(G)}{2}\Big\rceil+2\).
Źródło:
Discussiones Mathematicae Graph Theory; 2021, 41, 1; 51-64
2083-5892
Pojawia się w:
Discussiones Mathematicae Graph Theory
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Copper recovery from waste printed circuit boards and the correlation of Cu, Pb, Zn by ionic liquid
Autorzy:
Li, F.
Chen, M.
Powiązania:
https://bibliotekanauki.pl/articles/208289.pdf
Data publikacji:
2017
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
electronic waste
printed circuit boards
heavy metals
waste disposal
metale ciężkie
odpady elektroniczne
odpad płytek drukowanych
miedź
Opis:
Waste printed circuit boards (WPCBs) contain not only harmful materials but also many valuable resources, especially metals, which attracts more and more attention from the public. In this study, a sulfonic acid functionalized ionic liquid ([BSO3HPy]OTf) was used to recycle copper from WPCBs. Zinc and lead, represented as typical heavy metals, were chosen to study the leaching behavior and their relation to copper. Five factors such as particle size, ionic liquid (IL) concentration, H2O dose, solid to IL ratio and temperature were investigated in detail. The results showed that copper leaching rate was high, up to 99.77%, and zinc leaching rate reached the highest value of 74.88% under the optimum conditions. Lead cannot be leached effectively and the leaching rate was mostly low than 10%, which indirectly indicated that [BSO3HPy]OTf has a good selectivity to lead. Besides, the interaction of copper, lead and zinc was characterized macroscopically by means of statistical methods. The Spearman correlation analysis showed that copper and zinc had a highly positive correlation. Lead had little relation to copper, which to some extent indicated that the effect of zinc on copper leaching behavior was bigger than that of lead.
Źródło:
Environment Protection Engineering; 2017, 43, 4; 55-66
0324-8828
Pojawia się w:
Environment Protection Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Forecasting Yield Curves in an Adaptive Framework
Autorzy:
Chen, Ying
Li, Bo
Powiązania:
https://bibliotekanauki.pl/articles/483285.pdf
Data publikacji:
2011
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
interest rates
functional principal component analysis
local parametric model
Nelson-Siegel model
Opis:
Forecasting yield curves with regime switches is important in academia and financial industry. As the number of interest rate maturities increases, it poses difficulties in estimating parameters due to the curse of dimensionality. To deal with such a feature, factor models have been developed. However, the existing approaches are restrictive and largely based on the stationarity assumption of the factors. This inaccuracy creates non-ignorable financial risks, especially when the market is volatile. In this paper, a new methodology is proposed to adaptively forecast yield curves. Specifically, functional principal component analysis (FPCA) is used to extract factors capable of representing the features of yield curves. The local AR(1) model with time-dependent parameters is used to forecast each factor. Simulation and empirical studies reveal the superiority of this method over its natural competitor, the dynamic Nelson-Siegel (DNS) model. For the yield curves of the U.S. and China, the adaptive method provides more accurate 6- and 12-month ahead forecasts.
Źródło:
Central European Journal of Economic Modelling and Econometrics; 2011, 3, 4; 237-259
2080-0886
2080-119X
Pojawia się w:
Central European Journal of Economic Modelling and Econometrics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effect of food-grade guar gum on flotation separation of chalcopyrite and monoclinic pyrrhotite in low-alkali systems
Autorzy:
Chen, Xiong
Gu, Guohua
Li, Lijuan
Chen, Zhixiang
Powiązania:
https://bibliotekanauki.pl/articles/110629.pdf
Data publikacji:
2019
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
food-grade guar gum
chalcopyrite
monoclinic pyrrhotite
flotation depressant
Opis:
The flotation separation of chalcopyrite from monoclinic pyrrhotite using food-grade guar gum (FGG) as a depressant was studied through micro flotation and flotation kinetics experiments, zeta potential, adsorption measurements and scanning electron microscope (SEM) analysis as well as infrared spectroscopy analysis. The flotation tests showed that the reagent scheme of depressant FGG 40 mg/dm3, collector PAX (potassium amyl xanthate) 10 mg/dm3 and frother MIBC (Methyl isobutyl carbinol) 10 mg/dm3 at pH 8.0 could achieve selective flotation separation of chalcopyrite from monoclinic pyrrhotite (a concentrate with Cu grade of 22.35% and recovery of 82.52% was achieved from the mixed minerals flotation), which indicated that FGG exhibited a selective depression effect on monoclinic pyrrhotite The kinetics, zeta potential, adsorption, SEM and infrared studies revealed that the depressant FGG could absorb more strongly on the surface of monoclinic pyrrhotite than chalcopyrite. Additionally, the results revealed that the interaction of FGG with the monoclinic pyrrhotite surface was governed primarily by strong chemisorption, whereas FGG mainly bonded to chalcopyrite through hydrogen bonding bonding. This property was the reason why FGG had excellent depression selectivity toward monoclinic pyrrhotite and weak depression effect on chalcopyrite flotation.
Źródło:
Physicochemical Problems of Mineral Processing; 2019, 55, 2; 437-447
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł

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