The automatic validation tool for PDDL2.1

The 3rd International Planning Competition [1] was a great success and a cornerstone to this success was the initial definition of a semantics for the language used in the competition, PDDL2.1. This created a general understanding of the semantics of the domains defined using this language and therefore a general understanding of what constitutes a valid plan. With this consensus on what a valid plan is it was possible to implement an automatic plan validator, VAL. This tool conveys what is a valid plan in PDDL2.1 to anyone developing a planner using this language, as well as providing extra information in a L ATEX report featuring graphs of changing numerical values and a Gantt chart (see figure 2). Actions With Continuous Effects A numerical quantity that can be changed, a function in PDDL, is called a primitive numerical expression (PNE). These PNEs can have continuous change initiated with changes made to the values of their (time) derivatives by durative actions. The effect starts at the beginning of the durative action and ends at the end of the durative action. The introduction of continuous change creates two further complications to the discrete temporal model: 1) Continuous changes can interact with one another, and 2) Invariant conditions may depend on values that are continuously changing. The key extension to the discrete temporal model is that interactin

Single Z' production at CLIC based on e^- gamma collisions

We analyze the potential of CLIC based on e- gamma collisions to search for new $Z'$ gauge boson. Single Z' production at e-gamma colliders in two SU(3)_C X SU(3)_L X U(1)_N models: the minimal model and the model with right-handed (RH) neutrinos is studied in detail. Results show that new Z' gauge bosons can be observed at the CLIC, and the cross sections in the model with RH neutrinos are bigger than those in the minimal one.Comment: 11 pages, 4 figures, To appear in JET

VAL : automatic plan validation, continuous effects and mixed initiative planning using PDDL

This paper describes aspects of our plan validation tool, VAL. The tool was initially developed to support the 3rd International Planning Competition, but has subsequently been extended in order to exploit its capabilities in plan validation and development. In particular, the tool has been extended to include advanced features of PDDL2.1 which have proved important in mixed-initiative planning in a space operations project. Amongst these features, treatment of continuous effects is the most significant, with important effects on the semantic interpretation of plans. The tool has also been extended to keep abreast of developments in PDDL, providing critical support to participants and organisers of the 4th IPC

The effects of electron and gamma radiation on epoxy-based materials

Specimens of graphite/epoxy composites and epoxy resins were exposed to electron and gamma radiation, followed by mechanical property and fundamental measurements. Measurement techniques included: scanning electron microscopy, X-ray diffraction analysis, and electron spin resonance spectroscopic analysis. Results indicate little or no change in flexural properties of miniature specimens of a graphite/epoxy composite and no change in failure mode at the fiber-resin interface and in the crystallinity of the fiber and the resin. Some doubt in the observation of stable flexural properties is cast by electron paramagnetic resonance spectra of a relatively large number of radiation-generated radicals. These generally lead to a change in cross-linking and in chain-scissioning which should alter mechanical properties

Validating plans with exogenous events

We are concerned with the problem of deciding the validity of a complex plan involving interacting continuous activity. In these situations there is a need to model and reason about the continuous processes and events that arise as a consequence of the behaviour of the physical world in which the plan is expected to execute. In this paper we describe how events, which occur as the outcome of uncontrolled physical processes, can be taken into account in determining whether a plan is valid with respect to the domain model. We do not consider plan generation issues in this paper but focus instead on issues in domain modelling and plan validation

Study of filtration mechanics and sampling techniques Annual technical summary report, phase 4, 1967-1968

Filtration mechanics and fluid contamination control in hydraulic system

Study of filtration mechanics and sampling techniques, phase 4 Annual report, 1967-1968

Filtration mechanics and fluid contaminatio

Propellant material compatibility program and results

The effects of long-term (up to 10 years) contact of inert materials with earth-storable propellants were studied for the purpose of designing chemical propulsion system components that can be used for current as well as future planetary spacecraft. The primary experimental work, and results to date are reported. Investigations include the following propellants: hydrazine, hydrazine-hydrazine nitrate blends, monomethyl-hydrazine, and nitrogen tetroxide. Materials include: aluminum alloys, corrosion-resistant steels, and titanium alloys. More than 700 test specimen capsules were placed in long-term storage testing at 43 C in the special material compatibility facility. Material ratings relative to the 10-year requirement have been assigned