321 research outputs found
Atomistic subsemirings of the lattice of subspaces of an algebra
Let A be an associative algebra with identity over a field k. An atomistic
subsemiring R of the lattice of subspaces of A, endowed with the natural
product, is a subsemiring which is a closed atomistic sublattice. When R has no
zero divisors, the set of atoms of R is endowed with a multivalued product. We
introduce an equivalence relation on the set of atoms such that the quotient
set with the induced product is a monoid, called the condensation monoid. Under
suitable hypotheses on R, we show that this monoid is a group and the class of
k1_A is the set of atoms of a subalgebra of A called the focal subalgebra. This
construction can be iterated to obtain higher condensation groups and focal
subalgebras. We apply these results to G-algebras for G a group; in particular,
we use them to define new invariants for finite-dimensional irreducible
projective representations.Comment: 14 page
Multi-stage linear programming optimization for pump scheduling
Open Access journalCopyright © 2013 The Authors. Published by Elsevier Ltd.12th International Conference on Computing and Control for the Water Industry, CCWI2013This study presents a methodology based on Linear Programming for determining the optimal pump schedule on a 24-hour basis, considering as decision variables the continuous pump flow rates which are subsequently transformed into a discrete schedule. The methodology was applied on a case study derived from the benchmark Anytown network. To evaluate the LP reliability, a comparison was made with solutions generated by a Hybrid Discrete Dynamically Dimensioned Search (HD-DDS) algorithm. The cost associated with the result derived from the LP initial solution was shown to be lower than that obtained with repeated HD-DDS runs with differing random seeds
Privacy in geo-social networks: proximity notification with untrusted service providers and curious buddies
A major feature of the emerging geo-social networks is the ability to notify a user when any of his friends (also called buddies) happens to be geographically in proximity. This proximity service is usually offered by the network itself or by a third party service provider (SP) using location data acquired from the users. This paper provides a rigorous theoretical and experimental analysis of the existing solutions for the location privacy problem in proximity services. This is a serious problem for users who do not trust the SP to handle their location data and would only like to release their location information in a generalized form to participating buddies. The paper presents two new protocols providing complete privacy with respect to the SP and controllable privacy with respect to the buddies. The analytical and experimental analysis of the protocols takes into account privacy, service precision, and computation and communication costs, showing the superiority of the new protocols compared to those appeared in the literature to date. The proposed protocols have also been tested in a full system implementation of the proximity service
Novel strategies for preventing dysbiosis in the oral cavity
Oral diseases affect over three billion people worldwide, making it one of the most common infections. Recent studies show that one approach to reducing the risk of chronic infections, such as caries, gingivitis, periodontitis, and halitosis, is to control the ecology of the oral microbiome instead of completely removing both the harmful and beneficial microorganisms. This is based on the knowledge that oral diseases are not caused by a single pathogen but rather by a shift in the homeostasis of the entire microbiota, a process known as dysbiosis. Consequently, it is of the utmost importance to implement strategies that are able to prevent and control oral dysbiosis to avoid serious complications, including heart, lung, and other systemic diseases. Conventional treatments include the use of antibiotics, which further disrupt the equilibrium in the oral microbiota, together with the mechanical removal of the decayed cavity area following its formation. Therefore, it is imperative to implement alternative strategies with the potential to overcome the disadvantages of the current therapy, namely, the use of broad-spectrum antibiotics. In this sense, probiotics and postbiotics have received particular attention since they can modulate the oral microbiota and decrease the dysbiosis rate in the oral cavity. However, their mechanisms of action need to be addressed to clarify and drive their possible applications as preventive strategies. In this sense, this review provides an overview of the potential of probiotics and postbiotics, focusing on their antimicrobial and antibiofilm activities as well as their ability to modulate the inflammatory response. Finally, it also showcases the main advantages and disadvantages of orodispersible films—a promising delivery mechanism for both probiotics and postbiotics to target oral dysbiosis.info:eu-repo/semantics/publishedVersio
Penggunaan Informasi Keuangan untuk Memprediksi Keuntungan Investasi Bagi Investor di Pasar Modal (Studi Kasus pada Perusahaan Manufaktur Barang Konsumsi Sub Sektor Makanan dan Minuman di Bei Periode 2011-2012)
Tujuan penelitian ini adalah menguji apakah pertumbuhan laba, perputaran kas, perputaran persediaan dan perputaran piutang, merupakan prediktor keuntungan investasi (laba per lembar saham) di masa mendatang. Variabel penelitian terdiri dari Pertumbuhan Laba (X1), Perputaran Kas (X2) dan Perputaran Persediaan (X3), Perputaran Piutang (X4) dan Laba Per Lembar Saham (Y). Populasi penelitian ini adalah data laporan keuangan Perusahaan manufaktur sektor industri barang konsumsi sub sektor makanan dan minuman dan terdaftar di Bursa Efek Indonesia pada periode 2011 – 2014 dengan penentuan sampel menggunakan purposive sampling sedangkan teknik analisis yang digunakan adalah regresi linier berganda. Hasil dari penelitian ini bahwa pertumbuhan laba berpengaruh negatif dan tidak signifikan terhadap laba per lembar saham (EPS), sedangkan perputaran kas, perputaran persediaan dan perputaran piutang berpengaruh negatif dan signifikan terhadap laba per lembar saham. Berdasarkan hasil pengujian di hasilkan bahwa variabel bebas yang dominan berpengaruh terhadap laba per lembar saham adalah perputaran kas
Development, Validation and Preliminary Experiments of a Measuring Technique for Eggs Aging Estimation Based on Pulse Phase Thermography
Assessment of the freshness of hen eggs destinated to human consumption is an extremely important goal for the modern food industry and sale chains, as eggs show a rapid natural aging which also depends on the storage conditions. Traditional techniques, such as candling and visual observation, have some practical limitations related to the subjective and qualitative nature of the analysis. The main objective of this paper is to propose a robust and automated approach, based on the use of pulsed phase thermography (PPT) and image processing, that can be used as an effective quality control tool to evaluate the freshness of eggs. As many studies show that the air chamber size is proportional to the egg freshness, the technique relies on the monitoring of the air chamber parameters to infer egg aging over time. The raw and phase infrared images are acquired and then post-processed by a dedicated algorithm which has been designed to automatically measure the size of the air chamber, in terms of normalized area and volume. The robustness of the method is firstly assessed through repeatability and reproducibility tests, which demonstrate that the uncertainty in the measure of the air chamber size never exceeds 5%. Then, an experimental campaign on a larger sample of 30 eggs, equally divided into three size categories (M, L, XL), is conducted. For each egg, the main sizes of the air chamber are measured with the proposed method and their evolution over time is investigated. Results have revealed, for all the egg categories, the existence of an analytic relationship and a high degree of correlation (R-2 > 0.95) between the geometric data of the air chamber and the weight loss, which is a well-known marker of egg aging
Insights into the effect of chitosan upon biofilm formation of several oral pathogenic microorganisms
Experimental testing of an adsorption thermal energy storage system
The objective of this work is to test and characterize a lab-scale silica gel/water test bench realized at POLIMI labs and operating as Thermal Energy Storage (TES) system for domestic applications. Several charging and discharging cycles were performed setting 20-35, 30-50, and 80-90 °C as heat transfer fluid temperatures for the evaporation, condensation/adsorption and desorption processes. The system performance is evaluated in terms of energy efficiency, charge and discharge rate, and operating cost
Immune response: the Achilles’ heel of the stem cell-based regenerative therapies
Besides trauma, several pathological conditions which directly affect the normal functioning of organs, require new therapeutic strategies to repair damaged or diseased tissues. Tissue regeneration is a complex and spatiotemporal process involving a plethora of cell types, including various immune cells and stem cells in a synchronized relationship. However, individual parameters, namely ageing, obesity, diabetes, and chronic conditions, have been intrinsically correlated with poor regenerative properties of adult tissues. While vast progress has been made regarding stem cell-based therapy to direct self-healing, the immune response is still the Achilles’ heel of such strategies. Whereas the role of effector immune cells has been well defined along the regenerative process, an understanding of the behavior of the main adult stem cells, namely mesenchymal stem cells (MSCs) and hematopoietic stem and progenitor cells (HSPCs), along the different phases of the regenerative process could clarify how these stem cells can be used to positively influence the immune response. In this scope, this review highlights the main interactions between these stem cells and immune cells during tissue repair, exploring the most important regenerative properties of stem cells and correlating them with the modulation of the immune response during tissue regeneration. Furthermore, the utmost strategies used to explore how the behavior and stem cell fate are affected by specific microenvironments and/or stimuli usually found during a regenerative process, are emphasized. This clarification may provide critical insight into the molecular mechanisms by which stem cells modulate the immune response in a positive feedback loop toward tissue repair
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