Computing with Infinite Objects: the Gray Code Case

Infinite Gray code has been introduced by Tsuiki as a redundancy-free representation of the reals. In applications the signed digit representation is mostly used which has maximal redundancy. Tsuiki presented a functional program converting signed digit code into infinite Gray code. Moreover, he showed that infinite Gray code can effectively be converted into signed digit code, but the program needs to have some non-deterministic features (see also H. Tsuiki, K. Sugihara, "Streams with a bottom in functional languages"). Berger and Tsuiki reproved the result in a system of formal first-order intuitionistic logic extended by inductive and co-inductive definitions, as well as some new logical connectives capturing concurrent behaviour. The programs extracted from the proofs are exactly the ones given by Tsuiki. In order to do so, co-inductive predicates \bS and \bG are defined and the inclusion \bS \subseteq \bG is derived. For the converse inclusion the new logical connectives are used to introduce a concurrent version $\S_{2}$ of $S$ and \bG \subseteq \bS_{2} is shown. What one is looking for, however, is an equivalence proof of the involved concepts. One of the main aims of the present paper is to close the gap. A concurrent version \bG^{*} of \bG and a modification \bS^{*} of \bS_{2} are presented such that \bS^{*} = \bG^{*}. A crucial tool in U. Berger, H. Tsuiki, "Intuitionistic fixed point logic" is a formulation of the Archimedean property of the real numbers as an induction principle. We introduce a concurrent version of this principle which allows us to prove that \bS^{*} and \bG^{*} coincide. A further central contribution is the extension of the above results to the hyperspace of non-empty compact subsets of the reals

Vorschläge für den Einstieg in einen umsatzsteuerlichen Refund bei PPP-Inhabermodellen

Bei der Auslagerung staatlicher Tätigkeiten auf private Partner kommt es für den Bereich personalintensiver Dienstleistungen durch die anfallende deutsche Umsatzsteuer zu einer zusätzlichen Kostenbelastung, die die Hoheitsträger bisher oft von Outsourcing abhält. Für den Bereich der PPP-Inhabermodelle werden Lösungen aufgezeigt, wie diese Diskriminierung bei der deutschen Umsatzsteuer gemildert werden kann. Dabei dienen ausländische Regelungen als Orientierung. Die Grundgedanken lassen sich auch auf andere Vertragsmodelle übertragen. --Umsatzsteuer,Public Private Partnership,Personalintensive Dienstleistungen

Free Speech for Tourists

In this paper we report on the application of a natural language search interface in the tourism domain for searching for accommodation throughout Austria. We describe the analysis of real-world queries obtained by a field test where our interface has been made publicly available through the largest Austrian web-based tourism platform Tiscover. This analysis shows how users formulate queries when they are not limited by search interfaces with structured forms consisting of check boxes, radio buttons and special-purpose text fields

Unexpected Hospital Admissions from a Remote Outpatient Surgicenter

Background: A remote nonhospital outpatient surgical facility in the western suburbs of Chicago has been functioning for ten years. A review of their consecutive patients and admission rate was carried out from the day of opening.Design: A retrospective study of all patients admitted from the facility to the hospital is presented.Methods: 158,408 surgical diagnostic and therapeutic procedures were performed over a ten-year period.Results: 128 patients were admitted to the hospital for treatment of their problems consequent to treatment at the Center for Surgery. The causes of admission included pain, nausea and vomiting, cardiac, respiratory and bleeding considerations.Conclusions: Outpatient surgical treatment may be provided on a large-scale basis away from the hospital with low hospital admission rates and low complication rates. The patients thus are able to return to their homes on the same day of the procedure in an efficient, economic, and less timeconsuming manner

Computing with Infinite Objects: the Gray Code Case

Infinite Gray code has been introduced by Tsuiki as a redundancy-free representation of the reals. In applications the signed digit representation is mostly used which has maximal redundancy. Tsuiki presented a functional program converting signed digit code into infinite Gray code. Moreover, he showed that infinite Gray code can effectively be converted into signed digit code, but the program needs to have some non-deterministic features (see also H. Tsuiki, K. Sugihara, "Streams with a bottom in functional languages"). Berger and Tsuiki reproved the result in a system of formal first-order intuitionistic logic extended by inductive and co-inductive definitions, as well as some new logical connectives capturing concurrent behaviour. The programs extracted from the proofs are exactly the ones given by Tsuiki. In order to do so, co-inductive predicates \bS and \bG are defined and the inclusion \bS \subseteq \bG is derived. For the converse inclusion the new logical connectives are used to introduce a concurrent version $\S_{2}$ of $S$ and \bG \subseteq \bS_{2} is shown. What one is looking for, however, is an equivalence proof of the involved concepts. One of the main aims of the present paper is to close the gap. A concurrent version \bG^{*} of \bG and a modification \bS^{*} of \bS_{2} are presented such that \bS^{*} = \bG^{*}. A crucial tool in U. Berger, H. Tsuiki, "Intuitionistic fixed point logic" is a formulation of the Archimedean property of the real numbers as an induction principle. We introduce a concurrent version of this principle which allows us to prove that \bS^{*} and \bG^{*} coincide. A further central contribution is the extension of the above results to the hyperspace of non-empty compact subsets of the reals

Regio- and stereoselective fungal oxyfunctionalisation of limonenes

Selective transformations of limonene by asco- and basidiomycetes were investigated. On the shake flask scale, Penicillium citrinum hydrated R-(+)-limonene to α-terpineol [83% regioselectivity (rs), more than 80 mg l-1 product yield], and Gongronella butleri catalysed the terminal oxidation to yield perillyl alcohol (60% rs, 16 mg l-1). On the laboratory bioreactor scale, Penicillium digitatum produced a peak concentration of 506 mg α-terpineol l-1 in the fed-batch mode, equivalent to a theoretical yield of 67%, and no volatile by-products were found. Fusarium proliferatum transformed R-(+)-limonene enantiospecifically to cis-(+)-carveol (98.6% ee, more than 35 mg l-1 product yield) and S-(-)-limonene predominantly to trans-(-)-carveol (96.3% ee). Pleurotus sapidus selectively dehydrogenised the accumulating trans-(-)-carveol to the corresponding enantiopure R-(-)-carvone. The results show that a careful selection of strain and bioprocess parameters may improve both the yield and the optical purity of a desired product