“The big sweep”: On the power of the wavefront approach to Voronoi diagrams

We show that the wavefront approach to Voronoi diagrams (a deterministic line-sweep algorithm that does not use geometric transform) can be generalized to distance measures more general than the Euclidean metric. In fact, we provide the first worst-case optimal (O (n logn) time,O(n) space) algorithm that is valid for the full class of what has been callednice metrics in the plane. This also solves the previously open problem of providing anO (nlogn)-time plane-sweep algorithm for arbitraryL _k -metrics. Nice metrics include all convex distance functions but also distance measures like the Moscow metric, and composed metrics. The algorithm is conceptually simple, but it copes with all possible deformations of the diagram. Research partially supported by the Natural Sciences and Engineering Research Council of Canada. Research partially supported by the Deutsche Forschungsgemeinschaft, Grant No. Kl 655/2-1.     

Strukturanalytische Untersuchungen an Folgeprodukten aus Sulfonamiden. VIII. Zur Struktur der Reaktionsprodukte aus 1,1,3-trisubst. Thioharnstoffen und N-Tosyl-iminothiokohlensäuremethylester-chlorid

Structure-Analytical Investigations of Consecutive Products of Sulphonamides. VIII. About the Structure of Reaction Products from 1,1,3-Trisubst. Thioureas and N-Tosyl-iminothiocarbonic Acid Methylester Chlorides The structure of a variety of reaction products from 1,1,3-trisubstituted thioureas ( 1 a – e ) and N-tosyl-iminothiocarbonic acid methylester chlorides ( 2 ) is investigatigated with respect to whether a sequence  SO₂ NC S C (structure I ) or  SO₂ NC N C (structure I ) is form ed. The problem is solved by means of m.s. and i.r. spectra as well as the Feigl test. The results of these investigations show that structure I is formed.     

Substituierte N,N′-Bis(thiazol-2-yl)-diaminoalkane aus α-Thiocyanato-acetophenonen und N,N′-Dialkyl-diamino-alkanen

Substituted N,N′-Bis(thiazol-2-yl)-diaminoalkanes from α-Thiocyanato-acetophenones and N,N′-Dialkyl-diaminoalkanes α-Thiocyanato-acetophenones 1 react with N,N′-dialkyl-diaminoalkanes 2 in the presence of an appropriate weak acid (acetic acid, propionic acid, benzoic acid) to give the hitherto unknown N,N′-dialkyl-N,N′-bis(4-aryl-thiazol-2-yl)-diaminoalkanes 3 . As reaction medium aliphatic alcohols (ethanol, methanol), halogenated hydrocarbons (methylene chloride, chloroform, carbon tetrachloride) or dipolar-aprotic solvents (acetonitrile, dimethylformamide) can be used. - I.r., u.v., n.m.r. and mass spectroscopic data of the novel bisthiazoles 3 are reported.     

Strukturanalytische Untersuchungen an Folgeprodukten aus Sulfonamiden. V. Infrarotspektroskopische und thermoanalytische Untersuchungen an polymorphen Modifikationen von N-substituierten S-Methyl-N′-tosyl-isothioharnstoffen

Structure-Analytical Investigations of Consecutive Products of Sulphonamides. V. Infrared Spectroscopic and Thermoanalytical Studies of Polymorphic Modifications of N-Substituted S-Methyl-N′-tosyl-isothioureas Four compounds ( 1d, 1e, 1h, 1p ) out of twelve N-substituted S-methyl-N′-tosylisothioureas were shown to form polymorphic modifications. Attempts were made to isolate each single specimen and to characterize it by means of differential scanning calorimetry and infrared spectroscopy. The results clearly revealed that both different hydrogen bonding and conformational effects are responsible for the formation of the polymorphic species. With the help of ¹⁵N labeled compounds the presence of the sulphonylimino structure in any modification was proved. The v(NH) and δ_s(SO₂) band positions are used to divide the polymorphs into two groups A and B.     

Efficient Parallel Graph Algorithms for Coarse-Grained Multicomputers and BSP

In this paper we present deterministic parallel algorithms for the coarse-grained multicomputer (CGM) and bulk synchronous parallel (BSP) models for solving the following well-known graph problems: (1) list ranking, (2) Euler tour construction in a tree, (3) computing the connected components and spanning forest, (4) lowest common ancestor preprocessing, (5) tree contraction and expression tree evaluation, (6) computing an ear decomposition or open ear decomposition, and (7) 2-edge connectivity and biconnectivity (testing and component computation). The algorithms require O(log p) communication rounds with linear sequential work per round (p = no. processors, N = total input size). Each processor creates, during the entire algorithm, messages of total size O(log (p) (N/p)) . The algorithms assume that the local memory per processor (i.e., N/p ) is larger than p ^ε , for some fixed ε > 0 . Our results imply BSP algorithms with O(log p) supersteps, O(g log (p) (N/p)) communication time, and O(log (p) (N/p)) local computation time. It is important to observe that the number of communication rounds/ supersteps obtained in this paper is independent of the problem size, and grows only logarithmically with respect to p . With growing problem size, only the sizes of the messages grow but the total number of messages remains unchanged. Due to the considerable protocol overhead associated with each message transmission, this is an important property. The result for Problem (1) is a considerable improvement over those previously reported. The algorithms for Problems (2)—(7) are the first practically relevant parallel algorithms for these standard graph problems. Received July 5, 2000; revised April 16, 2001.     

Electric generation system design: Management,startup, and operation of IEA distributed collector solar system in Almeria,Spain

On 31 July 1981, 550 KWe were delivered to the remote village of Tabernas, Almeria, Spain from the Distributed Collector Solar Thermal-Electric Plant designed and built by an International Consortium and sponsored by nine countries of the International Energy Agency (IEA). The project is now completed and in operation. The management and startup experience are summarized.     

Implementing data structures on a hypercube multiprocessor, and applications in parallel computational geometry

In this paper, we study the problem of implementing standard data structures on a hypercube multiprocessor. We present a technique for efficiently executing multiple independent search processes on a class of graphs called ordered h-level graphs. We show how this technique can be utilized to implement a segment tree on a hypercube, thereby obtaining O(long²n) time algorithms for solving the next element search problem, the trapezoidal composition problem, and the triangulation problem.     

Charcot spinal arthropathy in congenital insensitivity to pain

Regioselective radioiodination of N-trifluoroacetyl 3,4-dimethoxy-6-trifluoroacetoxymercurio-L-phenylalanine ethyl ester 1 under no-carrier-added condition gave 6-[125I]iodo protected L-DOPA with a labeling efficiency of more than 85%, and no-carrier-added 6-[125I]I-L-DOPA was obtained with a radio-chemical purity of over 95% after hydrolysis and chromatography. A nonradioactive standard of 6-iodo protected L-DOPA was synthesized by the iododemercuration of 6-mercuric trifluoroacetate protected L-DOPA 1 using I2 in chloroform. 6-[125I]I-L-DOPA showed high brain accumulation and rapid blood clearance in mice. The rat brain slice studies indicated high affinity of 6-[125I]I-L-DOPA for carrier-mediated and stereoselective active transport systems. The tissue homogenate analysis revealed that most of the accumulated radioactivity was intact 6-[125I]I-L-DOPA. Thus, 6-[123I]I-L-DOPA appears to be a suitable single photon emission computed tomography (SPECT) tracer for the selective measurement of cerebral L-amino acid transport, having no affinity for dopamine metabolism.     

Esterification of Kraft lignin as a method to improve structural and mechanical properties of lignin‐polyethylene blends

Lignin is a promising candidate for blends with thermoplastic polymers. Still, this endeavour is a challenge due to poor compatibility between both components. In this article, the effect of lignin esterification on the improvement of the compatibility between hardwood Kraft lignin and high‐density polyethylene (PE‐HD) is investigated. For this purpose, lignin was esterified with acetic, propionic, and butyric anhydride; its amount in the blends varied from 10 to 40%. Light microscopic images of blends show a reduction in particle size and a more homogeneous distribution with increasing length of the ester carbon chains (C2 to C4). Modification of lignin enhances the moduli and strength characteristics of the blends. Butyrated lignin performs best, as tensile strength of blends can be retained near that of pure PE‐HD with up to 40% lignin content. An additional investigation of unmodified lignin with reduced particle size confirms that modification is the decisive factor to enhance blend properties; a sole reduction of particle size is insufficient. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 44582.