Abstraction refinement for games with incomplete information

Counterexample-guided abstraction refinement (CEGAR) is used in automated software analysis to find suitable finite-state abstractions of infinite-state systems. In this paper, we extend CEGAR to games with incomplete information, as they commonly occur in controller synthesis and modular verification. The challenge is that, under incomplete information, one must carefully account for the knowledge available to the player: the strategy must not depend on information the player cannot see. We propose an abstraction mechanism for games under incomplete information that incorporates the approximation of the players\' moves into a knowledge-based subset construction on the abstract state space. This abstraction results in a perfect-information game over a finite graph. The concretizability of abstract strategies can be encoded as the satisfiability of strategy-tree formulas. Based on this encoding, we present an interpolation-based approach for selecting new predicates and provide sufficient conditions for the termination of the resulting refinement loop

Synthesis of fault-tolerant distributed systems

A distributed system is fault-tolerant if it continues to perform correctly even when a subset of the processes becomes faulty. Fault-tolerance is highly desirable but often difficult to implement. In this paper, we investigate fault-tolerant synthesis, i.e., the problem of determining whether a given temporal specification can be implemented as a fault-tolerant distributed system. As in standard distributed synthesis, we assume that the specification of the correct behaviors is given as a temporal formula over the externally visible variables. Additionally, we introduce the fault-tolerance specification, a CTL* formula describing the effects and the duration of faults. If, at some point in time, a process becomes faulty, it becomes part of the external environment and its further behavior is only restricted by the fault-tolerance specification. This allows us to model a large variety of fault types. Our method accounts for the effect of faults on the values communicated by the processes, and, hence, on the information available to the non-faulty processes. We prove that for fully connected system architectures, i.e., for systems where each pair of processes is connected by a communication link, the fault-tolerant synthesis problem from CTL* specifications is 2EXPTIME-complete

EVALUATION OF SOME CLINICO-LABORATORY AND CYTOPHOTOMETRIC PARAMETERS AS EARLY DIAGNOSTIC TESTS FOR LEAD INTOXICATION

The clinical manifestation and extent of intoxication by lead aerosols in 51 workers from lead-dangerous manufactures has been follow ed-up. The values of erythrocytometric and laboratory parameters have been estimated. Significant aberrations in the mean erythrocyte diameter, mean erythrocyte thickness and mean erythrocyte spherical index as well as in the urinary delta-aminolevulinic acid excretion have been established during the preclinical stage of saturnism. Morphometric parameters along with delta-aminolevulinic acid possess the highest information value concerning lead intoxication followed by blood hemoglobin values. Both moderate reticulocytosis and erythrocytes with basophilic punctations are insufficiently indicative for the early etiologic diagnosis. Cytomorphometric abnormalities which become more outlined with advancing pathological alterations are of high specificity and validity as early diagnostic tests for lead intoxication

Management Accounting In Agricultural Enterprises – The Budgeting Function

The significance of the information created through management accounting and its limited use in the management of agricultural enterprises are the main motives for writing this article. We defend the thesis that if budgeting were implemented in agricultural enterprises, this would lead to more efficient management. The purpose of the paper is – on the basis of presenting the relationship between management and accounting – to outline the capacity of the planning and budgeting system for setting management objectives and parameters which acquire various quantitative and qualitative dimensions; this shall be achieved through managerial decisions. We propose a conceptual model of the planning and budgeting system at the agricultural enterprise which shall reflect its specific characteristics and create information for its future development; forecast its financial state, the results of the activity, the cash flows, the changes in the assets and the capital

Performance Analysis of Uplink Packet Schedulers in Cellular Networks with Relaying

Deployment of intermediate relay nodes in cellular networks, e,g, UMTS/ HSPA, has been proposed for service enhancement, which is of particular importance for uplink users at the cell edge suffering from low power capacity and relatively poor channel conditions. In this paper, we propose and investigate a number of uplink packet scheduling schemes deploying the relay functionality in different ways. Using a combined packet and flow level analysis capturing the specifics of the scheduling schemes and the random behavior of the users (initiation and completion of flow transfers), the performance of the various schemes is evaluated and compared to a reference scenario where relaying is not used. The main performance measures considered in our study are the instantaneous data rate, the energy consumption and the mean flow transfer time. Interestingly, considering flow transfer times, it is found that the use of relay nodes is not only particularly beneficial for users at the cell edge but also has a strongly positive effect on the performance of users at locations close to the base station

Monitoring temporal information flow

We present a framework for monitoring information flow in security-critical reactive systems, such as communication protocols, cell phone apps, document servers and web browsers. The secrecy requirements in such systems typically vary over time in response to the interaction with the environment. Standard notions of secrecy, like noninterference, must therefore be extended by specifying precisely when and under what conditions a particular event needs to remain secret. Our framework is based on the temporal logic SecLTL, which combines the standard temporal operators of linear-time temporal logic with the modal Hide operator for the specification of information flow properties. We present a first monitoring algorithm for SecLTL specifications, based on a translation of SecLTL formulas to alternating automata, and identify open research questions and directions for future work

Generalized Arago-Fresnel laws: The EME-flow-line description

We study experimentally and theoretically the influence of light polarization on the interference patterns behind a diffracting grating. Different states of polarization and configurations are been considered. The experiments are analyzed in terms of electromagnetic energy (EME) flow lines, which can be eventually identified with the paths followed by photons. This gives rise to a novel trajectory interpretation of the Arago-Fresnel laws for polarized light, which we compare with interpretations based on the concept of "which-way" (or "which-slit") information.Comment: 14 pages, 6 figure

Advances in surface EMG signal simulation with analytical and numerical descriptions of the volume conductor

Surface electromyographic (EMG) signal modeling is important for signal interpretation, testing of processing algorithms, detection system design, and didactic purposes. Various surface EMG signal models have been proposed in the literature. In this study we focus on 1) the proposal of a method for modeling surface EMG signals by either analytical or numerical descriptions of the volume conductor for space-invariant systems, and 2) the development of advanced models of the volume conductor by numerical approaches, accurately describing not only the volume conductor geometry, as mainly done in the past, but also the conductivity tensor of the muscle tissue. For volume conductors that are space-invariant in the direction of source propagation, the surface potentials generated by any source can be computed by one-dimensional convolutions, once the volume conductor transfer function is derived (analytically or numerically). Conversely, more complex volume conductors require a complete numerical approach. In a numerical approach, the conductivity tensor of the muscle tissue should be matched with the fiber orientation. In some cases (e.g., multi-pinnate muscles) accurate description of the conductivity tensor may be very complex. A method for relating the conductivity tensor of the muscle tissue, to be used in a numerical approach, to the curve describing the muscle fibers is presented and applied to representatively investigate a bi-pinnate muscle with rectilinear and curvilinear fibers. The study thus propose an approach for surface EMG signal simulation in space invariant systems as well as new models of the volume conductor using numerical methods

Anesthetic considerations for microlaryngeal surgery

Introduction: Microlaryngeal surgery encompasses a wide range of laryngeal procedures. Patients presenting for microlaryngeal surgery frequently have a difficult airway. The chosen approach to this airway depends on the pathology and the patient’s symptoms. The Aim of the study is to determine the risk factors and anesthetic problems during microlaryngeal surgery.Materials and Methods: A prospective cohort study including 100 patients undergoing microlaryngeal surgery in the Department of Otorhinolaryngology at the University Hospital „Queen Giovanna“ – ISUL, Sofia, in the period 2020–2021; Medical University-Sofia. Preoperative examination of the larynx is performed in all patients by Storz 8402 ZX fiber optic laryngoscope with video capability.Results and discussion: In 69% of the patients the tumor mass causing obstruction is localized in the area of the larynx, and in 31% of them the tumor mass is localized in the area of the hypopharynx. From the patients with tumor mass causing laryngeal obstruction 42% are with 1st degree of obstruction, 29% are with 2nd degree, 27% are with 3rd degree and 2% are with respiratory failure at rest. Twenty six percent (26%) of the patients had pulse rate<45 beats per minute during putting on the tube of Kleinsasser. This is very dangerous reflex reaction of the heart, which we believe is caused by parasympathetic nervous system. The rate of difficult endotracheal intubation among patients presenting for microlaryngeal surgery is higher than among the general surgical patient population. Difficulties during endotracheal intubation in our study are due to higher percent of laryngeal obstruction and pharyngeal restriction because of the intraoral masses.Conclusion: Anesthesia for microlaryngeal surgery has always been demanding, as often pathology interferes with the anesthesiologist’s field of work