269 research outputs found
Time-Constrained Temporal Logic Control of Multi-Affine Systems
In this paper, we consider the problem of controlling a dynamical system such
that its trajectories satisfy a temporal logic property in a given amount of
time. We focus on multi-affine systems and specifications given as
syntactically co-safe linear temporal logic formulas over rectangular regions
in the state space. The proposed algorithm is based on the estimation of time
bounds for facet reachability problems and solving a time optimal reachability
problem on the product between a weighted transition system and an automaton
that enforces the satisfaction of the specification. A random optimization
algorithm is used to iteratively improve the solution
An Efficient Formula Synthesis Method with Past Signal Temporal Logic
In this work, we propose a novel method to find temporal properties that lead
to the unexpected behaviors from labeled dataset. We express these properties
in past time Signal Temporal Logic (ptSTL). First, we present a novel approach
for finding parameters of a template ptSTL formula, which extends the results
on monotonicity based parameter synthesis. The proposed method optimizes a
given monotone criteria while bounding an error. Then, we employ the parameter
synthesis method in an iterative unguided formula synthesis framework. In
particular, we combine optimized formulas iteratively to describe the causes of
the labeled events while bounding the error. We illustrate the proposed
framework on two examples.Comment: 8 pages, 5 figures, conference pape
A Formal Methods Approach to Pattern Synthesis in Reaction Diffusion Systems
We propose a technique to detect and generate patterns in a network of
locally interacting dynamical systems. Central to our approach is a novel
spatial superposition logic, whose semantics is defined over the quad-tree of a
partitioned image. We show that formulas in this logic can be efficiently
learned from positive and negative examples of several types of patterns. We
also demonstrate that pattern detection, which is implemented as a model
checking algorithm, performs very well for test data sets different from the
learning sets. We define a quantitative semantics for the logic and integrate
the model checking algorithm with particle swarm optimization in a
computational framework for synthesis of parameters leading to desired patterns
in reaction-diffusion systems
Traffic Network Control from Temporal Logic Specifications
We propose a framework for generating a signal control policy for a traffic
network of signalized intersections to accomplish control objectives
expressible using linear temporal logic. By applying techniques from model
checking and formal methods, we obtain a correct-by-construction controller
that is guaranteed to satisfy complex specifications. To apply these tools, we
identify and exploit structural properties particular to traffic networks that
allow for efficient computation of a finite state abstraction. In particular,
traffic networks exhibit a componentwise monotonicity property which allows
reach set computations that scale linearly with the dimension of the continuous
state space
Effects of Natural Products on Sugar Metabolism and Digestive Enzymes
The risk of diabetes is increasing and it is anticipated that people with diabetes will double by 2030 with about 90% of patients having type-2 diabetes. The use of herbal remedies in the treatment of diabetes has increased because of the side effects (flatulence, diarrhoea, tiredness and upset stomach) of some common drugs. To prevent or delay type-2 diabetes, the blood glucose level needs to be controlled. The objective of this research was to make a preliminary assessment of the capacity of PFS (Plant Food Supplement) extracts to reduce glucose, fructose and sucrose transport (acarbose-like activity) across the Caco-2 cell monolayers and inhibit digestive enzymes by PFS extracts. Sucrase activity is responsible for the hydrolysis of sucrose to fructose and glucose in the brush border membrane of the small intestine. Accordingly, inhibiting glucose uptake in the intestine may be beneficial for diabetic patients in controlling their blood glucose level. The initial steps of the in vitro tests development involved determining the activities of sucrase, maltase, isomaltase and human salivary α-amylase in an acetone-extract of rat intestinal tissues, improving on a previously published method by analysing glucose concentration via the hexokinase assay, and analysing the effect of PFS on sugar transporters using a previously published method using the Caco-2 cell monolayer. The literature evidence for the inhibition of cellular glucose uptake and transport by polyphenols across Caco-2 cells is limited. Also, to the best of our knowledge, this research is the first report regarding the analysis of cellular uptake and transport of 14C-sucrose and 14C-fructose using the Caco-2 cell monolayer with polyphenol-containing extracts. Additionally, 14C radioactivity was used due to its easy detection and allowed high sensitivity. Glucose, fructose and sucrose transport across the Caco-2 cell monolayer was significantly attenuated in the presence of PFS. Green tea, German chamomile and Vitis Viniferae extracts inhibited the transport of glucose, fructose and sucrose when tested independently. However, the Vitis Viniferae extracts were not able to achieve 50% inhibition for the sucrose and fructose transport. While the cellular uptake of glucose and fructose was inhibited by the PFS extracts, they were effective on the cellular uptake of sucrose. By contrast, Pelargonium and Echinacea were ineffective for both the transport and cellular uptake of sugars. Purified German chamomile and green tea extracts were found to be moderate inhibitors of α-amylase digestion of amylopectin and α-glucosidase enzymes.
Due to the acarbose-like activity of the PFS extracts, they may have a potential role to reduce the risk of diabetes by inhibiting the hydrolysis of starches and reducing post-prandial blood glucose spikes. PFS may be seen as beneficial for use by diabetics as part of a nutritional intervention and in combination with exercise and drug treatment
A Novel MDP Based Decision Support Framework to Restore Earthquake Damaged Distribution Systems
Electric power network expanded rapidly in recent decades due of the
excessive need of electricity in every aspect of life, including critical
infrastructures such as medical services, and transportation and communication
systems. Natural disasters are one of the major reasons of electricity outage.
It is extremely important to restore electrical energy in the shortest time
possible after a disaster. This paper proposes a decision support method for
electric system operators to restore electricity to the critical loads in a
distribution system after an earthquake. The proposed method employs Markov
Decision Process to find the optimal restoration scheme based on the
Probability of Failure of critical structures determined by using the Peak
Ground Acceleration values recorded by observatories and earthquake research
centers during earthquakes.Comment: Presented in ISGT 201
Comparison of Gross Motor Skills of 8-10 Years Old Students Active in Different Sport Branches
The aim of this study was to investigate the basic motor skill levels of 8-10 years old children active in different sports branches according to TGMD-III test depending on the levels of gender and sports branches. The study encompassed 239 athletes of 8-10 age groups on a voluntary basis who had been doing sports for at least one year. The data required to achieve the objectives determined in the research were obtained using TGMD-III test protocol. Kurtosis-Skewness and Kolmagorov-Smirnov analyses were performed for normality test of data and it was found that the data were not distributed normally and so nonparametric tests were used. Mann Whitney U test was used for paired groups and Kruskal Wallis analysis was used for comparison of the others. In TGMD-III gender comparison of the athletes, a significant difference was found in total Locomotor tests, total object control and total TGMD-III (p<0.01). There are significant differences in the comparison of TGMD-III sports branch of the athletes in Locomotor tests total, object control tests total and TGMD-III overall total (p<0.01). As a result, the gross motor skills of the footballers were found to be significantly better compared to the other branches. It is thought that the difference between the branches resulted from the motoric and physiological characteristics required by the structures of the branches. In addition, sports age and training styles of the athletes are thought to have affected the measurement results
Finite bisimulations for switched linear systems
In this paper, we consider the problem of constructing a finite bisimulation quotient for a discrete-time switched linear system in a bounded subset of its state space. Given a set of observations over polytopic subsets of the state space and a switched linear system with stable subsystems, the proposed algorithm generates the bisimulation quotient in a finite number of steps with the aid of sublevel sets of a polyhedral Lyapunov function. Starting from a sublevel set that includes the origin in its interior, the proposed algorithm iteratively constructs the bisimulation quotient for the region bounded by any larger sublevel set. We show how this bisimulation quotient can be used for synthesis of switching laws and verification with respect to specifications given as syntactically co-safe Linear Temporal Logic formulae over the observed polytopic subsets
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