INFINITE MATRICES ASSOCIATED WITH POWER SERIES AND APPLICATION TO OPTIMIZATION AND MATRIX TRANSFORMATIONS

In this paper we first recall some properties of triangle Toeplitz matrices of the Banach algebra Sr associated with power series. Then for boolean Toeplitz matrices M we explicitly calculate the product MN that gives the number of ways with N arcs associated with M. We compute the matrix BN (i, j), where B (i, j) is an infinite matrix whose the nonzero entries are on the diagonals m &#8722; n = i or m &#8722; n = j. Next among other things we consider the infinite boolean matrix B+&#8734; that have infinitely many diagonals with nonzero entries and we explicitly calculate (B+&#8734;)N. Finally we give necessary and sufficient conditions for an infinite matrix M to map c (BN (i, 0)) to c.</p

Solving a Berth Assignment Problem

The Berth Allocation Problem (BAP) is the problem of allocating berthing spaces and scheduling container vessels on these spaces so as to minimize total weighted time. We study a version of BAP in which containers are moved between vessels and berth space is abundant. Thus, the problem reduces to optimally assign vessels to berths. We call it the Berth Assignment Problem (BASP). We formulate it as a non standard Quadratic Assignment Problem, and we show that BASP is NP-Hard. The formulation is simplified, linearized, and valid inequalities are found. Numerical results are shown

A Quadratic Model and A Heuristic for Sizing an Hybrid Renewable Energy System

Collaboration avec le laboratoire GREAH de l'université du HavreInternational audienceAn Hybrid Renewable Energy System (HRES) may be defined as a system in which various renewable energy components (solar panels, wind turbines,...,batteries) are interconnected in such a way to satisfy, at any time, a demand of electrical energy. Since electrical power supplied by each component (taking independently) depends on different environment conditions (sun, wind), and since the demand fluctuates, the objective of such system is to be able to produce energy at any time by optimally exploiting favourable weather 2 conditions for each component, and to stock available energy (for latter use in non favourable conditions) of surproduction periods. The induced problem is to compute the optimal number of each component, minimizing installation and maintenance costs. We propose an integer quadratic programming model to solve this problem. The model is linearized and solved with a heuristic scheme. Numerical results, based on data obtained on a site in Dakar (Senegal) in which the system has to be installed, are provided

Complexity of primal-dual interior-point algorithm for linear programming based on a new class of kernel functions

summary:In this paper, we first present a polynomial-time primal-dual interior-point method (IPM) for solving linear programming (LP) problems, based on a new kernel function (KF) with a hyperbolic-logarithmic barrier term. To improve the iteration bound, we propose a parameterized version of this function. We show that the complexity result meets the currently best iteration bound for large-update methods by choosing a special value of the parameter. Numerical experiments reveal that the new KFs have better results comparing with the existing KFs including $\log t$ in their barrier term. To the best of our knowledge, this is the first IPM based on a parameterized hyperbolic-logarithmic KF. Moreover, it contains the first hyperbolic-logarithmic KF (Touil and Chikouche in Filomat 34:3957-3969, 2020) as a special case up to a multiplicative constant, and improves significantly both its theoretical and practical results

Extension of primal-dual interior point method based on a kernel function for linear fractional problem

Our aim in this work is to extend the primal-dual interior point method based on a kernel function for linear fractional problem. We apply the techniques of kernel function-based interior point methods to solve a standard linear fractional program. By relying on the method of Charnes and Cooper [3], we transform the standard linear fractional problem into a linear program. This transformation will allow us to define the associated linear program and solve it efficiently using an appropriate kernel function. To show the efficiency of our approach, we apply our algorithm on the standard linear fractional programming found in numerical tests in the paper of A. Bennani et al. [4], we introduce the linear programming associated with this problem. We give three interior point conditions on this example, which depend on the dimension of the problem. We give the optimal solution for each linear program and each linear fractional program. We also obtain, using the new algorithm, the optimal solutions for the previous two problems. Moreover, some numerical results are illustrated to show the effectiveness of the method

Enhancement of the bond portfolio Immunization under a parallel shift of the yield curve

Abstract Hedging under a parallel shift of the interest rate curve is well-known for a long date in finance literature. It is based on the use of a duration-convexity approximation essentially pioneered by . However the situation is inaccurately formulated such that the obtained result is very questionable. Motivations and enhancement of such approximation have been performed in our recent working paper JEL classification numbers: G11, G12

Ziziphus nummularia attenuates the malignant phenotype of human pancreatic cancer cells: Role of ros

Pancreatic cancer (PC) is the fourth leading cause of all cancer-related deaths. Despite major improvements in treating PC, low survival rate remains a major challenge, indicating the need for alternative approaches, including herbal medicine. Among medicinal plants is Ziziphus nummu-laria (family Rhamnaceae), which is a thorny shrub rich in bioactive molecules. Leaves of Ziziphus nummularia have been used to treat many pathological conditions, including cancer. However, their effects on human PC are still unknown. Here, we show that the treatment of human pancreatic ductal adenocarcinoma cells (Capan-2) with Ziziphus nummularia ethanolic extract (ZNE) (100–300 µg/mL) attenuated cell proliferation in a time-and concentration-dependent manner. Pretreatment with N-acetylcysteine, an ROS scavenger, attenuated the anti-proliferative effect of ZNE. In addition, ZNE significantly decreased the migratory and invasive capacity of Capan-2 with a concomitant downregulation of integrin α2 and increased cell–cell aggregation. In addition, ZNE inhibited in ovo angiogenesis as well as reduced VEGF and nitric oxide levels. Furthermore, ZNE downregulated the ERK1/2 and NF-κB signaling pathways, which are known to drive tumorigenic and metastatic events. Taken together, our results suggest that ZNE can attenuate the malignant phenotype of Capan-2 by inhibiting hallmarks of PC. Our data also provide evidence for the potential anticancer effect of Ziziphus nummularia, which may represent a new resource of novel anticancer compounds, especially ones that can be utilized for the management of PC

Large expert-curated database for benchmarking document similarity detection in biomedical literature search

Document recommendation systems for locating relevant literature have mostly relied on methods developed a decade ago. This is largely due to the lack of a large offline gold-standard benchmark of relevant documents that cover a variety of research fields such that newly developed literature search techniques can be compared, improved and translated into practice. To overcome this bottleneck, we have established the RElevant LIterature SearcH consortium consisting of more than 1500 scientists from 84 countries, who have collectively annotated the relevance of over 180 000 PubMed-listed articles with regard to their respective seed (input) article/s. The majority of annotations were contributed by highly experienced, original authors of the seed articles. The collected data cover 76% of all unique PubMed Medical Subject Headings descriptors. No systematic biases were observed across different experience levels, research fields or time spent on annotations. More importantly, annotations of the same document pairs contributed by different scientists were highly concordant. We further show that the three representative baseline methods used to generate recommended articles for evaluation (Okapi Best Matching 25, Term Frequency-Inverse Document Frequency and PubMed Related Articles) had similar overall performances. Additionally, we found that these methods each tend to produce distinct collections of recommended articles, suggesting that a hybrid method may be required to completely capture all relevant articles. The established database server located at https://relishdb.ict.griffith.edu.au is freely available for the downloading of annotation data and the blind testing of new methods. We expect that this benchmark will be useful for stimulating the development of new powerful techniques for title and title/abstract-based search engines for relevant articles in biomedical research.Peer reviewe