Structured Mapping of Petri Net States and Events for FPGA Implementations

The paper presents a new method of structured encoding of global internal states and events in Reconfigurable Logic Controllers, which are directly mapped into Field Programmable Gate Arrays (FPGA). Modular, concurrently decomposed, colored state machine is chosen as a intermediate model, before the mapping of Petri net into an array structure of dedicated but very flexible and reliable digital system. The initial textual specification in formal Gentzen logic serves both as a design description for a rapid prototyping, as well as formal model, suitable for detailed computer-based reasoning about optimized and synthesized logic controller, implemented in configurable hardware. Only the selected linear subset from general, universal propositional Gentzen Logic is necessary to deduce several properties of the net, such as relations of nonconcurrency among structurally ordered macroplaces. The goal of this paper is to present the design methodology for modeling and synthesis of discrete controllers using related Petri net theory, rule-based theory (mathematical logic), and VHDL

Transition based synthesis with modular encoding of Petri nets into FPGAs

The paper describes a new method for the synthesis of the application specific logic controllers, targeted into the FPGA. The initial steps of the proposed control algorithm rely on the notion of a Petri net, which is an easy way to describe parallel processes. The algorithm is oriented on transition based logic description. It allows easy analysis of dynamics and functioning of the circuit. The logic circuit is also decomposed into logic blocks responsible for particular functions. It leads to the compact implementation with usage of different kind of logic elements like. Additionally such decomposition allows easy analysis of circuit

Application of an Exact Transversal Hypergraph in Selection of SM-Components

Part 9: Embedded Systems and Petri NetsInternational audienceThe paper deals with the application of the hypergraph theory in selection of State Machine Components (SM-Components) of Petri nets [1,2].As it is known, Petri nets are widely used for modeling of concurrency processes. However, in order to implement the concurrent automaton, an initial Petri net ought to be decomposed into sequential automata (SM-Components), which can be easily designed as an Finite-State-Machine (FSM) or Microprogrammed Controller [3]. The last step of the decomposition process of the Petri nets is selection of SM-Components. This stage is especially important because it determines the final number of sequential automata. In the article we propose a new idea of SM-Components selection. The aim of the method is reduction of the computational complexity from exponential to polynomial. Such a reduction can be done if the selection hypergraph belongs to the exact transversal hypergraphs (xt-hypergraphs) class. Since the recognition and generation of the first transversal in the xt-hypergraphs are both polynomial, the complete selection process can be performed in polynomial time. The proposed ideas are an extension of the concept presented in [1].The proposed method has been verified experimentally. The conducted investigations have shown that for more than 85% of examined Petri nets the selection process can be done via xt-hypergraphs

From UML specification into FPGA implementation

In the paper a method of using the Unified Modeling Language for specification of digital systems, especially logic controllers, is presented. The proposed method is based mainly on the UML state machine diagrams and uses Hierarchical Concurrent Finite State Machines (HCFSMs) as a temporary model. The paper shows a way to transform the UML diagrams, expressed in XML language, to the form that is acceptable by reconfigurable FPGAs (Field Programmable Gate Arrays). The UML specification is used to generate an effective program in Hardware Description Languages (HDLs), especially Verilog

Telomerase inhibition abolishes the tumorigenicity of pediatric ependymoma tumor-initiating cells

Pediatric ependymomas are highly recurrent tumors resistant to conventional chemotherapy. Telomerase, a ribonucleoprotein critical in permitting limitless replication, has been found to be critically important for the maintenance of tumor-initiating cells (TICs). These TICs are chemoresistant, repopulate the tumor from which they are identified, and are drivers of recurrence in numerous cancers. In this study, telomerase enzymatic activity was directly measured and inhibited to assess the therapeutic potential of targeting telomerase. Telomerase repeat amplification protocol (TRAP) (n = 36) and C-circle assay/telomere FISH/ATRX staining (n = 76) were performed on primary ependymomas to determine the prevalence and prognostic potential of telomerase activity or alternative lengthening of telomeres (ALT) as telomere maintenance mechanisms, respectively. Imetelstat, a phase 2 telomerase inhibitor, was used to elucidate the effect of telomerase inhibition on proliferation and tumorigenicity in established cell lines (BXD-1425EPN, R254), a primary TIC line (E520) and xenograft models of pediatric ependymoma. Over 60 % of pediatric ependymomas were found to rely on telomerase activity to maintain telomeres, while no ependymomas showed evidence of ALT. Children with telomerase-active tumors had reduced 5-year progression-free survival (29 +/- A 11 vs 64 +/- A 18 %; p = 0.03) and overall survival (58 +/- A 12 vs 83 +/- A 15 %; p = 0.05) rates compared to those with tumors lacking telomerase activity. Imetelstat inhibited proliferation and self-renewal by shortening telomeres and inducing senescence in vitro. In vivo, Imetelstat significantly reduced subcutaneous xenograft growth by 40 % (p = 0.03) and completely abolished the tumorigenicity of pediatric ependymoma TICs in an orthotopic xenograft model. Telomerase inhibition represents a promising therapeutic approach for telomerase-active pediatric ependymomas found to characterize high-risk ependymomas.Canadian Institutes of Health Research [MOP 82727]info:eu-repo/semantics/publishedVersio

Metabolite ratios as potential biomarkers for type 2 diabetes:a DIRECT study

Aims/hypothesis Circulating metabolites have been shown to reflect metabolic changes during the development of type 2 diabetes. In this study we examined the association of metabolite levels and pairwise metabolite ratios with insulin responses after glucose, glucagon-like peptide-1 (GLP-1) and arginine stimulation. We then investigated if the identified metabolite ratios were associated with measures of OGTT-derived beta cell function and with prevalent and incident type 2 diabetes. Methods We measured the levels of 188 metabolites in plasma samples from 130 healthy members of twin families (from the Netherlands Twin Register) at five time points during a modified 3 h hyperglycaemic clamp with glucose, GLP-1 and arginine stimulation. We validated our results in cohorts with OGTT data (n = 340) and epidemiological case–control studies of prevalent (n = 4925) and incident (n = 4277) diabetes. The data were analysed using regression models with adjustment for potential confounders. Results There were dynamic changes in metabolite levels in response to the different secretagogues. Furthermore, several fasting pairwise metabolite ratios were associated with one or multiple clamp-derived measures of insulin secretion (all p Conclusion/interpretation In this study we have shown that the Val_PC ae C32:2 metabolite ratio is associated with an increased risk of type 2 diabetes and measures of insulin secretion and resistance. The observed effects were stronger than that of the individual metabolites and independent of known risk factors.</p

Appareil de mesure de la constante diélectrique des liquides fortement conductibles

Les mesures de la constante diélectrique et des angles de pertes (tg δ) des substances fortement polaires dans les solvants polaires sont liées avec des grandes difficultés d’appareillage. Les ponts de mesure utilisés le plus fréquemment ne peuvent être appliqués qu’aux mesures de la constante diélectrique de liquides dont le tg δ ne dépasse pas 0,3. Les mesures de la constante diélectrique de certains polymères ne peuvent être exécutés qu’en solvants polaires et conductibles dont tg δ > 1. Dans ce but il fallait donc réaliser un appareil sensible de courant alternatif pour déterminer la constante diélectrique dans le domaine de 1-80. Le pont de mesure réalisé joint une simplicité de circuit électrique avec une sensibilité comparable avec celle de la méthode de battement

Prototyping of Concurrent Control Systems with Application of Petri Nets and Comparability Graphs

This paper shows a novel prototyping technique for concurrent control systems described by interpreted Petri nets. The technique is based on the decomposition of an interpreted Petri net into concurrent sequential automata. In general, minimum decomposition requires runtime that is exponential in the number of Petri net places. We show that in many cases, including the real-life ones, the minimum decomposition problem can be solved in polynomial time. The proposed method allows implementing a concurrent control system using minimal number of sequential components, which requires polynomial time and can be applied to most of the considered cases. The presented concept is illustrated by a real-life industrial example of a beverage production and distribution machine implemented in a field programmable gate array.authorsversionpublishe