931 research outputs found
Synthesizing Protocol Specifications from Service Specifications in Timed Extended Finite State Machines
We propose a specification model and present a method to algorithmically
derive a protocol specification from a service specification based on
the model.
Unlike the previous models based on finite state machines, the proposed
model can explicitly express concurrency, synchronization, and timing
requirements such as delays and timeouts. We assume that there exists
a reliable communication channel between any two protocol entities and
the maximum delay for each channel is bounded by a positive constant.
Because of the variable nature of the communication delays along with
the time constraints associated with events, no protocol specification
can fully simulate the service specification.
The proposed method derives a protocol specification that is optimal
in the sense that it provides the largest possible subset of the service
specification under the communication delay constraints.
We also give a method to derive a sub specification from a service
specification and a maximum communication delay of each channel such that
the sub specification, but no superset of it, can be simulated by the
derived protocol specification
Predictive Coding Strategies for Developmental Neurorobotics
In recent years, predictive coding strategies have been proposed as a possible means by which the brain might make sense of the truly overwhelming amount of sensory data available to the brain at any given moment of time. Instead of the raw data, the brain is hypothesized to guide its actions by assigning causal beliefs to the observed error between what it expects to happen and what actually happens. In this paper, we present a variety of developmental neurorobotics experiments in which minimalist prediction error-based encoding strategies are utilize to elucidate the emergence of infant-like behavior in humanoid robotic platforms. Our approaches will be first naively Piagian, then move onto more Vygotskian ideas. More specifically, we will investigate how simple forms of infant learning, such as motor sequence generation, object permanence, and imitation learning may arise if minimizing prediction errors are used as objective functions
Tsunami Flooding Probability determined by Probability Distribution Type
Source: ICHE Conference Archive - https://mdi-de.baw.de/icheArchiv
Arrhythmia surgery for atrial fibrillation associated with atrial septal defect: Right-sided maze versus biatrial maze
BackgroundAlthough it has been inferred that a biatrial maze procedure for atrial fibrillation in left-sided heart lesions may lead to better outcomes compared with a limited left atrial lesion set, it remains controversial whether the biatrial maze procedure is superior to the right atrial maze procedure in right-sided heart lesions.MethodsA retrospective review was performed for 56 adults who underwent surgical closure of atrial septal defect and various maze procedures for atrial fibrillation between June 1998 and February 2011. The median age at operation was 59 years (range, 34-79 years). Clinical manifestations of atrial fibrillation were paroxysmal in 8 patients, persistent in 15 patients, and long-standing persistent in 33 patients. A right atrial maze procedure was performed in 23 patients (group 1), and a biatrial maze procedure was performed in 33 patients (group 2). Treatment failure was defined as atrial fibrillation recurrence, development of atrial flutter or other types of atrial tachyarrhythmia, or implantation of a permanent pacemaker. The Cox proportional hazards model was used to identify risk factors for decreased time to treatment failure.ResultsDuring the median follow-up period of 49 months (range, 5-149 months), there was no early death and 1 late noncardiac death. On Cox survival model, group 1 showed a significantly decreased time to treatment failure in comparison with group 2 (hazard ratio, 5.11; 95% confidence interval, 1.59-16.44; PĀ =Ā .006). Maintenance of normal sinus rhythm without any episode of atrial fibrillation recurrence at 2 and 5 years postoperatively was 57% and 45% in group 1, respectively, and 82% and 69% in group 2, respectively.ConclusionsLeft-sided ablation in addition to a right atrial maze procedure leads to better electrophysiologic outcome in atrial fibrillation associated with atrial septal defect
Controls of Trajectories for Targeting of Magnetic Robotics in body: Magnetic Robotics of Biomedical Application
This paper presents a novel method to actively control magnetic field in a region-of-interest using three pairs electromagnetic coils system referred to here as extended distributed treatment Robotics. The developed controls of trajectories for targeting of magnetic robotics in body system contains hardware, software and magnetic Robotics/nanoscale material and the in vitro manipulation in real time. In this study, we used six identical solenoids coil placed on an XYZ-axis and the electromagnet was powered by current that can generate a high-gradient magnetic field in the desired direction. Real-time video microscopy supported by the LabVIEW vision system is integrated into the developed system for real-time monitoring. Moreover, the detection of object function is done through NI Vision Assistant, tracking function is through Math Script node in the LabVIEW simulation and ROI magnetic field actual measurement is done by the real-time magnetic sensor. The motion speed and direction of the Magnetic Robotics can also be manipulated using EMM system and Joystick controller
Physiologic dentin regeneration: its past, present, and future perspectives
Regenerative dentistry has rapidly progressed since the advancement of stem cell biology and material science. However, more emphasis has been placed on the success of tissue formation than on how well the newly generated tissue retains the original structure and function. Once dentin is lost, tertiary dentinogenesis can be induced by new odontoblastic differentiation or re-activation of existing odontoblasts. The characteristic morphology of odontoblasts generates the tubular nature of dentin, which is a reservoir of fluid, ions, and a number of growth factors, and protects the inner pulp tissue. Therefore, understanding the dynamic but delicate process of new dentin formation by odontoblasts, or odontoblast-like cells, following dentinal defects is crucial. In this regard, various efforts have been conducted to identify novel molecules and materials that can promote the regeneration of dentin with strength and longevity. In this review, we focus on recent progress in dentin regeneration research with biological molecules identified, and discuss its potential in future clinical applications
Complexity of Atherosclerotic Coronary Artery Disease and Long-Term Outcomes in Patients With Unprotected Left Main Disease Treated With Drug-Eluting Stents or Coronary Artery Bypass Grafting
ObjectivesThe aim of this study was to compare treatment effects of drug-eluting stents (DES) or coronary artery bypass grafting (CABG) for left main coronary artery (LMCA) disease according to the complexity of atherosclerotic disease burden.BackgroundLimited information is available on the relationships between the extent of coronary atherosclerosis and very long-term outcomes of surgical or percutaneous LMCA revascularization.MethodsA total of 1,146 patients with unprotected LMCA disease who received DES (n = 645) or underwent CABG (n = 501) were evaluated. The extent of atherosclerotic disease burden was measured using the SYNTAX (Synergy Between PCI With Taxus and Cardiac Surgery) score; a low-risk score was defined as ā¤22, an intermediate-risk score as 23 to 32, and a high-risk score as ā„33.ResultsAfter multivariate adjustment with the inverse-probability-of-treatment weighting method, the 5-year risks for death (6.1% for DES vs. 16.2% for CABG; hazard ratio [HR]: 0.52; 95% confidence interval [CI]: 0.21 to 1.28; p = 0.15) and the composite of death, Q-wave myocardial infarction, or stroke (6.4% vs. 16.2%; HR: 0.54; 95% CI: 0.22 to 1.34; p = 0.18) favored DES in patients with low-risk SYNTAX scores; in contrast, the 5-year risks for death (26.9% vs. 17.8%; HR: 1.46; 95% CI: 0.92 to 2.30; p = 0.11) and the composite outcome (27.6% vs. 19.5%; HR: 1.36; 95% CI: 0.87 to 2.12; p = 0.18) favored CABG in patients with high-risk SYNTAX scores (interaction p = 0.047 for death, interaction p = 0.08 for composite outcome). Patients undergoing CABG consistently had lower rates of target vessel revascularization.ConclusionsAccording to the complexity of concomitant coronary disease, there were differential treatment effects on long-term mortality in patients with unprotected LMCA disease who received DES or underwent CABG
Joint Channel Estimation and Phase Noise Suppression for OFDM Systems
The joint channel estimation and phase noise
suppression scheme for orthogonal frequency-division
multiplexing (OFDM) systems is proposed for a case where
channel estimation is needed symbol by symbol. In the proposed
scheme, channel estimation and phase noise suppression are
performed iteratively via the expectation-maximization (EM)
algorithm. The proposed algorithm mitigates the performance
degradation due to phase noise effectively while providing the
accurate channel estimate with comparatively few pilot
subcarriers so that the spectral efficiency of an OFDM system is
improved
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