13,561 research outputs found
A Three-Term Conjugate Gradient Method with Sufficient Descent Property for Unconstrained Optimization
Conjugate gradient methods are widely used for solving large-scale unconstrained optimization problems, because they do not need the storage of matrices. In this paper, we propose a general form of three-term conjugate gradient methods which always generate a sufficient descent direction. We give a sufficient condition for the global convergence of the proposed general method. Moreover, we present a specific three-term conjugate gradient method based on the multi-step quasi-Newton method. Finally, some numerical results of the proposed method are given
A Curvature Flow Unifying Symplectic Curvature Flow And Pluriclosed Flow
Streets and Tian introduced pluriclosed flow and symplectic curvature flow in
recent years. Here we construct a curvature flow to unify these two flows. We
show the short time existence of our flow and exhibit an obstruction to long
time existence.Comment: Corrected minor errors and updated references. Accepted in Pacific
Journal of Mathematic
'Ndrangheta dzisiaj - „włoska spółka jawna” czy międzynarodowy koncern przestępczy?
The purpose of this paper is to provide a book review of Giovanni Tizian’s literary debut entitled in Italian “Gotica, 'Ndrangheta, mafia e camorra oltrepassano la linea”, which was published in Italy in 2011 and in Poland in autumn 2013, after being translated into Polish by Karlina Dyjas-Fizzi. The book has been enthusiastically received by both critics and readers not only on the Italian Peninsula. Polish media have reported that Giovanni Tizian have been hailed a hero in Italy and thousands of citizens, politicians and social activists have expressed their solidarity with him. Il presente articolo è una recensione di un esordio letterario di Giovanni Tizian initolato in italiano “Gotica, ‘Ndrangheta, mafia e camorra oltrepassano la linea”, pubblicato in Italia in 20111 e in Polonia in autunno 2013, dopo essere tradotto in lingua polacca da Karlina Dyjas-Fizzi. Il libro è stato accolto con entusiasmo dai lettori e dai critici non solo sulla penisola italiana. I media polacchi hanno riferito che Giovanni Tizian è stato salutato come un eroe in Italia e che migliaia di cittadini, politici e attivisti sociali gli hanno espresso la loro solidarietà.Recenzowana praca to wydany jesienią 2013 r. polski przekład, dokonany przez Karolinę Dyjas-Fizzi, literackiego debiutu Giovanniego Tiziana, zatytułowanego w oryginale Gotica, 'ndrangheta, mafia e camorra oltrepassano la linea, publikacji, która ukazała się we Włoszech w 2011 roku. Książka ta została entuzjastycznie przyjęta przez krytykę i rzesze czytelników zarówno w Italii jak i poza jej granicami
A Comparison of Reform-Era Labor Force Participation Rates of China’s Ethnic Minorities and Han Majority
Previous research suggests that minorities are not faring well in China’s transition—both income and occupational attainment gaps are widening. We are particularly interested in whether the differences in majority and minority economic outcomes are the result of ethnicity per se, or whether they are artifacts of local economic conditions. In this paper, we employ data from the three most recent population censuses of China to explore differences in the labor force participation rates of a number of China’s important ethnic groups. We estimate urban labor force participation rates using probit regressions controlling for sex, marital status, educational attainment, age, ethnicity, and location. We also account for the geographic concentration of particular ethnic minorities and compare the participation rates of different ethnic groups within geographic regions that represent the areas of principal residence for each minority. We concentrate on seven important minority groups: Hui, Koreans, Manchu, Mongolians, Uygurs, Yi and Zhuang. We find that location has limited explanatory power in explaining differences in the probability of labor force participation between these important Chinese ethnic minorities and the majority Han.http://deepblue.lib.umich.edu/bitstream/2027.42/40181/3/wp795.pd
Tissue engineering of co-cultured skin substitutes using biocomposite membranes based on collagen and polycaprolactone
The preparation and characterisation of collagen: PCL, gelatin: PCL and gelatin/collagen:PCL biocomposites for manufacture of tissue engineered skin substitutes are reported. Films of collagen: PLC, gelatin: PCL (1:4, 1:8 and 1:20 w/w) and gelatin/collagen:PCL (1:8 and 1:20 w/w) biocomposites were prepared by impregnation of lyophilised collagen and/or gelatin mats by PCL solutions followed by solvent evaporation. In vitro assays of total protein release of collagen:PCL and gelatin: PCL biocomposite films revealed an expected inverse relationship between the collagen release rate and the content of synthetic polymer in the biocomposite samples that may be exploited for controlled presentation and release of biopharmaceuticals such as growth factors. Good compatibility of all biocomposite groups was proven by interaction with 3T3 fibroblasts, normal human epidermal keratinocytes (NHEK), and primary human epidermal keratinocytes (PHEK) and dermal fibroblasts (PHDF) in vitro respectively. The 1:20 collagen: PCL materials exhibiting good cell growth curves and mechanical characteristics were selected for engineering of skin substitutes in this work. The tissue-engineered skin model based on single-donor PHEK and PHDF with differentiated confluent epidermal layer and fibrous porous dermal layer was then developed successfully in vitro proven by SEM and immunohistochemistry assay. The following in vivo animal study on athymic mice revealed early complete wound healing in 10 days and good integration of co-cultured skin substitutes with adjacent mice skin structures. Thus the co-cultured skin substitutes based on 1:20 collagen: PCL biocomposite membranes was proven in principle. The approach to skin modelling reported here may find application in wound treatment, gene therapy and screening of new pharmaceuticals
Kilka uwag na temat usunięcia posła lub senatora z grupy parlamentarnej
The MP's expulsion from the parliamentary group is the issue examined in the paper. The most recent italian parliamentary chronicle has registered different cases of MP's expulsion. Furthermore the rising of the M5S party has contributed to emphasize the relevance of the issue. Indeed some members of the M5S have been expelled through consultation procedures via Internet. Finally the reform of the statute enacted to regulate the parliamentary election of the 'Camera dei deputati' (Italicum) could represent another opportunity to rethink the relationship between MPs and parliamentary groups. The author tries to identify formal guarantees and substantive conditions for the MP's expulsion l'articolo si occupa dell'espulsione del parlamentare dal gruppo parlamentare. Nei tempi più recenti la cronaca istituzionale ha registrato episodi di espulsione che hanno fatto discutere i costituzionalisti italiani. L'emersione del Movimento 5 Stelle ha inoltre dato nuova linfa al tema. La modifica della legge elettorale (c.d. Italicum), infine, potrebbe rappresentare un'ulteriore occasione di ripensamento del rapporto tra parlamentare e gruppo.Nell'intervento l'Autore prova a individuare alcune garanzie formali e alcuni presupposti sostanziali per l'adozione della misura di espulsione.Niniejszy artykuł poświęcony jest kwestii usunięcia (wydalenia) posła lub senatora z grupy parlamentarnej. Zaistniałe w ostatnim czasie we Włoszech przypadki wydalenia wywołały ożywione dyskusje wśród konstytucjonalistów. Ponadto pojawienie się na scenie politycznej Ruchu Pięciu Gwiazd przyczyniło się do dalszego zwiększenia znaczenia tej kwestii, bowiem decyzje o wydaleniu niektórych członków tej partii zapadły po dokonaniu konsultacji za pośrednictwem Internetu. Wreszcie nowa ordynacja wyborcza do Izby Reprezentantów (tzw. Italicum) może stanowić kolejną okazję do przemyśleń na temat relacji, jakie zachodzą między deputowanymi a grupami parlamentarnymi. Autor wskazuje również gwarancje formalne i materialne przesłanki związane z omawianą kwestią
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