Approximate Compliance Checking for Annotated Process Models

We describe a method for validating whether the states reached by a process are compliant with a set of constraints. This serves to (i) check the compliance of a new or altered process against the constraints base, and (ii) check the whole process repository against a changed constraints base, e.g., when new regulations come into being. For these purposes we formalize a particular class of compliance rules as well as annotated process models, the latter by combining a notion from the workflow literature with a notion from the AI actions and change literature. The compliance rules in turn pose restrictions on the desirable states. Each rule takes the form of a clausal constraint, i.e., a disjunction of literals. If for a given state there is a grounded clause none of whose literals are true, then the constraint is violated and indicates non-compliance. Checking whether a process is compliant with the rules involves enumerating all reachable states and is in general a hard search problem. Since long waiting times during process modelling are undesirable, it is important to explore restricted classes and approximate methods. We present a polynomial-time algorithm that, for a particular class of processes, computes the sets of literals that are necessarily true at particular points during process execution. Based on this information, we devise two approximate compliance checking methods. One of these is sound but not complete (it guarantees to find only non-compliance instances, but not to find all non-compliance instances); the other method is complete but not sound. We sketch how one can trace the state evolution back to the process activities which caused the (potential) non-compliance, and hence provide the user with some error diagnosis

The Maximum Scatter TSP on a Regular Grid

In the maximum scatter traveling salesman problem the objective is to find a tour that maximizes the shortest distance between any two consecutive nodes. This model can be applied to manufacturing processes, particularly laser melting processes. We extend an algorithm by Arkin et al. that yields optimal solutions for nodes on a line to a regular $m \times n$-grid. The new algorithm \textsc{Weave}(m,n) takes linear time to compute an optimal tour in some cases. It is asymptotically optimal and a $\frac{\sqrt{10}}{5}$-approximation for the $3\times 4$-grid, which is the worst case.Comment: 6 pages, 2 figures; to appear in OR Proceedings 201

Photodynamische Therapie (PDT) und wassergefiltertes Infrarot A (wIRA) bei Patienten mit therapierefraktären vulgären Hand- und Fußwarzen

Background: Common warts (verrucae vulgares) are human papilloma virus (HPV) infections with a high incidence and prevalence, most often affecting hands and feet, being able to impair quality of life. About 30 different therapeutic regimens described in literature reveal a lack of a single striking strategy. Recent publications showed positive results of photodynamic therapy (PDT) with 5-aminolevulinic acid (5-ALA) in the treatment of HPV-induced skin diseases, especially warts, using visible light (VIS) to stimulate an absorption band of endogenously formed protoporphyrin IX. Additional experiences adding waterfiltered infrared A (wIRA) during 5-ALA-PDT revealed positive effects. Aim of the study: First prospective randomised controlled blind study including PDT and wIRA in the treatment of recalcitrant common hand and foot warts. Comparison of "5-ALA cream (ALA) vs. placebo cream (PLC)" and "irradiation with visible light and wIRA (VIS+wIRA) vs. irradiation with visible light alone (VIS)". Methods: Pre-treatment with keratolysis (salicylic acid) and curettage. PDT treatment: topical application of 5-ALA (Medac) in "unguentum emulsificans aquosum" vs. placebo; irradiation: combination of VIS and a large amount of wIRA (Hydrosun® radiator type 501, 4 mm water cuvette, waterfiltered spectrum 590-1400 nm, contact-free, typically painless) vs. VIS alone. Post-treatment with retinoic acid ointment. One to three therapy cycles every 3 weeks. Main variable of interest: "Percent change of total wart area of each patient over the time" (18 weeks). Global judgement by patient and by physician and subjective rating of feeling/pain (visual analogue scales). 80 patients with therapy-resistant common hand and foot warts were assigned randomly into one of the four therapy groups with comparable numbers of warts at comparable sites in all groups. Results: The individual total wart area decreased during 18 weeks in group 1 (ALA+VIS+wIRA) and in group 2 (PLC+VIS+wIRA) significantly more than in both groups without wIRA (group 3 (ALA+VIS) and 4 (PLC+VIS)): medians and interquartile ranges: -94% (-100%/-84%) vs. -99% (-100%/-71%) vs. -47% (-75%/0%) vs. -73% (-92%/-27%). After 18 weeks the two groups with wIRA differed remarkably from the two groups without wIRA: 42% vs. 7% completely cured patients; 72% vs. 34% vanished warts. Global judgement by patient and by physician and subjective rating of feeling was much better in the two groups with wIRA than in the two groups without wIRA. Conclusions: The above described complete treatment scheme of hand and foot warts (keratolysis, curettage, PDT treatment, irradiation with VIS+wIRA, retinoic acid ointment; three therapy cycles every 3 weeks) proved to be effective. Within this treatment scheme wIRA as non-invasive and painless treatment modality revealed to be an important, effective factor, while photodynamic therapy with 5-ALA in the described form did not contribute recognisably - neither alone (without wIRA) nor in combination with wIRA - to a clinical improvement. For future treatment of warts an even improved scheme is proposed: one treatment cycle (keratolysis, curettage, wIRA, without PDT) once a week for six to nine weeks. © 2004 Fuchs et al; licensee German Medical Science. This is an Open Access article: verbatim copying and redistribution of this article are permitted in all media for any purpose, provided this notice is preserved along with the article's original URL : http://www.egms.de/en/gms/volume2.shtmlHintergrund: Vulgäre Warzen (Verrucae vulgares) sind humane Papillomvirus-Infektionen (HPV) mit einer hohen Inzidenz und Prävalenz, die am häufigsten Hände und Füße befallen und die in der Lage sind, die Lebensqualität zu beeinträchtigen. Etwa 30 in der Literatur beschriebene Therapieverfahren zeugen von einem Mangel an einer einzigen überzeugenden Strategie. Jüngste Veröffentlichungen zeigten positive Ergebnisse der Photodynamischen Therapie (PDT) mit 5-Aminolävulinsäure (5-ALA) in der Therapie von HPV-induzierten Hautkrankheiten, besonders Warzen, wobei sichtbares Licht (VIS) verwendet wird, um ein Absorptionsband des endogen aus 5-ALA gebildeten Protoporphyrin IX zu stimulieren. Weitere Erfahrungen, wassergefiltertes Infrarot A (wIRA) während der 5-ALA-PDT zusätzlich anzuwenden, offenbarten positive Wirkungen. Ziel der Untersuchung: Erste prospektive randomisierte kontrollierte Blind-Studie, die PDT und wIRA in die Behandlung von therapierefraktären vulgären Hand- und Fußwarzen einbezieht. Vergleich von "5-ALA-Salbe (ALA) vs. Placebo-Salbe (PLC)" und "Bestrahlung mit sichtbarem Licht und wIRA (VIS+wIRA) vs. Bestrahlung mit sichtbarem Licht allein (VIS)". Methoden: Vorbehandlung mit Keratolyse (Salizylsäure) und Kürettage. Photodynamische Therapie (PDT): topische Applikation von 5-ALA (Medac) in "Unguentum emulsificans aquosum" vs. Placebo; Bestrahlung: Kombination von sichtbarem Licht (VIS) und einem hohen Maß an wassergefiltertem Infrarot A (wIRA) (Hydrosun®-Strahler Typ 501, 4 mm Wasserküvette, wassergefiltertes Spektrum 590-1400 nm, kontaktfrei, typischerweise schmerzlos) vs. sichtbares Licht (VIS) allein. Nachbehandlung mit Vitamin-A-Säure-Salbe. Ein bis drei Therapiezyklen im Abstand von 3 Wochen. Hauptzielvariable: "Prozentuale Änderung der Gesamtwarzenfläche jedes Patienten über die Zeit" (18 Wochen). Globales Urteil von Patient und von Arzt sowie subjektive Einschätzung von Empfindung/Schmerz (visuelle Analogskalen). 80 Patienten mit therapierefraktären vulgären Hand- und Fußwarzen wurden randomisiert einer der vier Behandlungsgruppen (mit vergleichbarer Anzahl an Warzen in vergleichbaren Lokalisationen in allen Gruppen) zugeteilt. Ergebnisse: Die individuelle Gesamtwarzenfläche nahm während 18 Wochen in Gruppe 1 (ALA+VIS+wIRA) und in Gruppe 2 (PLC+VIS+wIRA) signifikant mehr als in den beiden Gruppen ohne wIRA (Gruppe 3 (ALA+VIS) und 4 (PLC+VIS)) ab: Mediane und Interquartil-Spannen: -94% (-100%/-84%) vs. -99% (-100%/-71%) vs. -47% (-75%/0%) vs. -73% (-92%/-27%). Nach 18 Wochen unterschieden sich die zwei Gruppen mit wIRA deutlich von den zwei Gruppen ohne wIRA: 42% vs. 7% komplett geheilte Patienten; 72% vs. 34% völlig verschwundene Warzen. Das globale Urteil von Patient und von Arzt und die subjektive Einschätzung des Empfindens waren in den zwei Gruppen mit wIRA viel besser als in den zwei Gruppen ohne wIRA. Folgerungen: Das oben beschriebene vollständige Therapieschema von Hand- und Fußwarzen (Keratolyse, Kürettage, Photodynamische Therapie, Bestrahlung mit VIS+wIRA, Vitamin-A-Säure-Salbe; drei Therapiezyklen im Abstand von 3 Wochen) erwies sich als effektiv. Innerhalb des Therapieschemas zeigte sich wIRA - als nicht-invasive und schmerzlose Therapiemodalität - als ein wichtiger, effektiver Faktor, während die Photodynamische Therapie mit 5-ALA in der beschriebenen Form nicht erkennbar - weder alleine (ohne wIRA) noch in Kombination mit wIRA - zu einer klinischen Verbesserung beitrug. Für die zukünftige Behandlung von Warzen wird ein weiter verbessertes Schema vorgeschlagen: ein Therapiezyklus (Keratolyse, Kürettage, wIRA, ohne PDT) einmal pro Woche für sechs bis neun Wochen

Reinforcement Learning for Planning Heuristics

Informed heuristics are essential for the success of heuristic search algorithms. But, it is difficult to develop a new heuris- tic which is informed on various tasks. Instead, we propose a framework that trains a neural network as heuristic for the tasks it is supposed to solve. We present two reinforcement learning approaches to learn heuristics for fixed state spaces and fixed goals. Our first approach uses approximate value iteration, our second ap- proach uses searches to generate training data. We show that in some domains our approaches outperform previous work, and we point out potentials for future improvements

Reacting Flow Prediction of the Low-Swirl Lifted Flame in an Aeronautical Combustor With Angular Air Supply

The development of lean-burn combustion systems is of paramount importance for reducing the pollutant emissions of future aero engine generations. By tilting the burners of an annular combustor in circumferential direction relative to the rotational axis of the engine, the potential of increased combustion stability is opened up due to an enhanced exhaust gas recirculation between adjacent flames. The innovative gas turbine combustor concept, called the Short Helical Combustor (SHC), allows the main reaction zone to be operated at low equivalence ratios. To exploit the higher stability of the fuel-lean combustion, a low-swirl lifted flame is implemented in the staggered SHC burner arrangement. The objective is to reach ultra-low NOx emissions by complete evaporation and extensive premixing of fuel and air upstream of the lean reaction zone. In the present work, a modeling approach is developed to investigate the characteristics of the lifted flame in an enclosed single-burner configuration, using the gaseous fuel methane. It is demonstrated that by using the Large Eddy Simulation method, the shape and lift-off height of the flame is adequately reproduced by means of the finite-rate chemistry approach. For the numerical prediction of the lean lifted flame in the SHC arrangement, the focus is on the interaction of adjacent burners. It is shown that the swirling jet flow is deflected towards the sidewall of the staggered combustor dome, which is attributed to the asymmetrical confinement. Since the stabilization mechanism of the low-swirl flame relies on outer recirculation zones, the upstream transport of hot combustion products back to the flame base is studied by the variation of the combustor confinement ratio. It turns out that increasing the combustor size amplifies the exhaust gas recirculation along the sidewall, and increases the temperature of recirculating burned gases. The present study emphasizes the capability of the proposed lean-burn combustor concept for future aero engine applications

Blütenvielfalt der Wildpflanzenarten in Getreidefeldern Europas

Die Ackerflächen Europas besitzen eine hohe floristische Artenvielfalt mit wichtigen ökologischen Funktionen der Blütenvielfalt. Im Rahmen der Kartierung von Wildpflanzenarten (Segetalflora) in Getreideanbauflächen unterschiedlicher Klimaregionen Europas wurde ein Teil der taxonomisch erfassten Arten fotografisch dokumentiert. Aus insgesamt 768 Arten wurde eine Bildtafel mit 49 Arten zusammengestellt und auf diese Weise die hohe Vielfalt der Blütenformen und der Blütenfarben visualisiert. Nur einige dieser Arten treten heute in größerer Zahl in Getreideanbauflächen mit hoher Nutzungsintensität auf, nahezu alle Arten dagegen in extensiven Systemen. Es wird auf Funktionen der Wildpflanzenarten für Invertebraten, als pflanzengenetische Ressourcen und für die Bodenmikroorganismenvielfalt hingewiesen. Für die Weiterentwicklung moderner landwirtschaftlicher Nutzungssysteme sollte Biodiversität als ein beabsichtigtes Produktionsgut integriert werden. Stichwörter: Wildpflanzen, Getreideanbau, Segetalflora, Europa, BlütenvielfaltDiversity of wild flowers in grain crop fields of EuropeSummaryEuropean arable land is home of highly diverse vegetation. Important ecological functions of this diversity include for example the diversity of pollinators. Within a project aiming at mapping the distribution of wild plants in grain crop fields in various climatic zones in Europe, a part of the species was documented by photos. Out of 768 species 49 species were selected for a photographic flower mosaic to visualize the great variety of flower types and colors. Only a few of these species actually occur abundantly within intensively managed grain crop fields, whereas all species occur in low input systems. Additional functions of wild plants within crop fields include the importance for invertebrates and soil microorganisms, and as plant genetical resources. We suggest to include biodiversity as a specific target for further development of modern agricultural productions systems.Keywords: wild plants species, grain field areas, weeds, segetalflora, Europe, diversity of flower

Reacting Flow Prediction of the Low-Swirl Lifted Flame in an Aeronautical Combustor With Angular Air Supply

The development of lean-burn combustion systems is of paramount importance for reducing the pollutant emissions of future aero engine generations. By tilting the burners of an annular combustor in circumferential direction relative to the rotational axis of the engine, the potential of increased combustion stability is opened up due to an enhanced exhaust gas recirculation between adjacent flames. The innovative gas turbine combustor concept, called the short helical combustor (SHC), allows the main reaction zone to be operated at low equivalence ratios. To exploit the higher stability of the fuel-lean combustion, a low-swirl lifted flame is implemented in the staggered SHC burner arrangement. The objective is to reach ultralow NOx emissions by complete evaporation and extensive premixing of fuel and air upstream of the lean reaction zone. In this work, a modeling approach is developed to investigate the characteristics of the lifted flame in an enclosed single-burner configuration, using the gaseous fuel methane. It is demonstrated that by using the large eddy simulation method, the shape and liftoff height of the flame are adequately reproduced by means of the finite-rate chemistry approach. For the numerical prediction of the lean lifted flame in the SHC arrangement, the focus is on the interaction of adjacent burners. It is shown that the swirling jet flow is deflected toward the sidewall of the staggered combustor dome, which is attributed to the asymmetrical confinement. Since the stabilization mechanism of the low-swirl flame relies on outer recirculation zones, the upstream transport of hot combustion products back to the flame base is studied by the variation of the combustor confinement ratio. It turns out that increasing the combustor size amplifies the exhaust gas recirculation along the sidewall, and increases the temperature of recirculating burned gases. This study emphasizes the capability of the proposed lean-burn combustor concept for future aero engine applications