Tutorial on Lisp Object- Oriented Programming for Blackboard Computation (Solving the Radar Tracking Problem)

This exposition is a tutorial on how object-oriented programming in Lisp can be used for programming a blackboard. Since we have used Franz Lisp and since object oriented programming in Franz is carried out via flavors, the exposition demonstrates how flavors can be used for this purpose. The reader should note that the different approaches to object-oriented programming share considerable similarity and, therefore, the exposition should be helpful to even those who may not wish to use flavors. We have used the radar tracking problem as a ‘medium’ for explaining the concepts underlying blackboard programming. The blackboard database is constructed solely of flavors which act as data structures as well as method-bearing objects. Flavor instances form the nodes and the levels of the blackboard. The methods associated with these flavors constitute a distributed monitor and support the knowledge sources in modifying the blackboard data. A rule-based planner is used to construct knowledge source activation records from the goals residing in the blackboard. These activation records are enqueued in a cyclic queueing system. A scheduler cycles through the queues and selects knowledge sources to fir

A TUTORIAL ON LISP OBJECT-ORIENTED PROGRAMMING FOR BLACKBOARD COMPUTATION (SOLVING THE RADAR TRACKING PROBLEM)

This exposition is a tutorial on how object-oriented programming (OOP) in Lisp can be used for programming a blackboard. Since we have used Common Lisp and the Common Lisp Object System (CLOS), the exposition demonstrates how object classes and the primary, before, and after methods associated with the classes can be used for this purpose. The reader should note that the different approaches to object-oriented programming share considerable similarity and, therefore, the exposition should be helpful to even those who may not wish to use CLOS. We have used the radar tracking problem as a \u27medium\u27 for explaining the concepts underlying blackboard programming. The blackboard database is constructed solely of classes which act as data structures as well as method-bearing objects. Class instances fonn the nodes and the levels of the blackboard. The methods associated with these classes constitute a distributed monitor and support the knowledge sources in modifying the blackboard data. A rule-based planner is used to construct knowledge source activation records from the goals residing in the blackboard. These activation records are enqueued in a cyclic queueing system. A scheduler cycles through the queues and selects knowledge sources to fire

Risk factors which predispose first-time traumatic anterior shoulder dislocations to recurrent instability in adults: a systematic review and meta-analysis

Recurrent instability following a first-time anterior traumatic shoulder dislocation may exceed 26%. We systematically reviewed risk factors which predispose this population to events of recurrence

In children 18 years and under, what promotes recurrent shoulder instability after traumatic anterior shoulder dislocation? A systematic review and meta-analysis of risk factors

Background Skeletal maturity and age-related changes in the composition of the glenoid labrum and joint capsule may influence rates of recurrent instability in children. We systematically review risk factors which predispose children to recurrent shoulder instability. Methods The systematic review-concerned studies published before May 2015. Statistical analysis was undertaken to compare rates of recurrence for each extracted risk factor. Pooled ORs were analysed using random effects meta-analysis. Results 6 retrospective cohort studies met the inclusion criteria. 8 risk factors were identified across the studies including age, sex, shoulder dominance and injury side, mechanism of injury, state of physis closure, and Hill-Sachs and Bankart lesions. The rate of recurrent instability was 73%. Children aged 14–18 years were 24 times more likely to experience recurrent instability than children aged 13 years and less (93% vs 40%; OR=24.14, 95% CI (3.71 to 156.99), Z=3.33, p=0.001, I2=6.83%). There was a non-significant trend indicating males were 3.4 times more likely to experience recurrent instability (OR=3.44, 95% CI (0.98 to 12.06), Z=1.93, p=0.053, I2=0%). Analysis of one study found that children with a closed physis are 14 times more likely to experience recurrent instability compared with those with an open physis (OR=14.0, 95% CI (1.46 to 134.25), Z=2.29, p=0.02, I2=0%) . Conclusions Male children aged 14 years and over had the greatest risk of recurrent shoulder instability following a first-time traumatic anterior shoulder dislocation. This meta-analysis summarises a mix of 6 acceptable and poor quality level III retrospective cohort studies. Further examination of this population with blinded prospective cohort studies will assist clinicians in the appropriate management of first-time traumatic anterior shoulder dislocation

Algebraic properties of Gardner's deformations for integrable systems

An algebraic definition of Gardner's deformations for completely integrable bi-Hamiltonian evolutionary systems is formulated. The proposed approach extends the class of deformable equations and yields new integrable evolutionary and hyperbolic Liouville-type systems. An exactly solvable two-component extension of the Liouville equation is found.Comment: Proc. conf. "Nonlinear Physics: Theory and Experiment IV" (Gallipoli, 2006); Theor. Math. Phys. (2007) 151:3/152:1-2, 16p. (to appear

A unified approach to computation of integrable structures

We expose (without proofs) a unified computational approach to integrable structures (including recursion, Hamiltonian, and symplectic operators) based on geometrical theory of partial differential equations. We adopt a coordinate based approach and aim to provide a tutorial to the computations.Comment: 19 pages, based on a talk on the SPT 2011 conference, http://www.sptspt.it/spt2011/ ; v2, v3: minor correction

(Non)local Hamiltonian and symplectic structures, recursions, and hierarchies: a new approach and applications to the N=1 supersymmetric KdV equation

Using methods of math.DG/0304245 and [I.S.Krasil'shchik and P.H.M.Kersten, Symmetries and recursion operators for classical and supersymmetric differential equations, Kluwer, 2000], we accomplish an extensive study of the N=1 supersymmetric Korteweg-de Vries equation. The results include: a description of local and nonlocal Hamiltonian and symplectic structures, five hierarchies of symmetries, the corresponding hierarchies of conservation laws, recursion operators for symmetries and generating functions of conservation laws. We stress that the main point of the paper is not just the results on super-KdV equation itself, but merely exposition of the efficiency of the geometrical approach and of the computational algorithms based on it.Comment: 16 pages, AMS-LaTeX, Xy-pic, dvi-file to be processed by dvips. v2: nonessential improvements of exposition, title change