Semantic Processing of Out-Of-Vocabulary Words in a Spoken Dialogue System

One of the most important causes of failure in spoken dialogue systems is usually neglected: the problem of words that are not covered by the system's vocabulary (out-of-vocabulary or OOV words). In this paper a methodology is described for the detection, classification and processing of OOV words in an automatic train timetable information system. The various extensions that had to be effected on the different modules of the system are reported, resulting in the design of appropriate dialogue strategies, as are encouraging evaluation results on the new versions of the word recogniser and the linguistic processor.Comment: 4 pages, 2 eps figures, requires LaTeX2e, uses eurospeech.sty and epsfi

Contributions to the chemistry of boron. Part 242. Rearrangement of bis(dimethylamino)bis(1-indenyl)diborane(4) into bis(dimethylamino)bis(3-indenyl)diborane(4)

Indenyllithium reacts with dichlorobis(dimethylamino)diborane(4) with formation of bis(dimethylamino)bis(1-indenyl)-diborane(4) which rearranges on heating to the isomer bis(dimethylamino)bis(3-indenyl)diborane(4). The mixed isomer bis(dimethylamino)(1-indenyl)(3-indenyl)diborane(4) was obtained from indenyllithium and chlorobis(dimethylamino)(3-indenyl)diborane(4). Crystal data of 1,2-bis(dimethylamino)-1,2-bis(1-indenyl)diborane(4) (I): monoclinic, space group P21/c, a 15.8977(3), b 7.5756(1), c 16.8297(3) .ANG., b 93.323(1) Deg, Z = 4, rc = 1.116 g/cm3, m(MoKa) = 0.064 mm-1, F(000) = 728, 2781 obsd. reflections with I > 4s(I), R = 0.0789, wR2 = 0.1812; 1,2-bis(dimethylamino)-1-(1-indenyl)-2-(3-indenyl)diborane(4) (II): triclinic, space group P.hivin.1, a 8.8466(1), b 10.3594(2), c 11.1737(3) .ANG., a 77.403(1), b 85.428(1), g 83.222(1) Deg, Z = 4, rc = 1.140 g/cm3, m(MoKa) = 0.065 mm-1, F(000) = 364, 2640 obsd. reflections with I > 4s(I), R = 0.0474, wR2 = 0.1141. The main structural differences between the 2 isomers I and II are a slightly shorter B-B bond in II, as well as a stronger twist about the B-B bond (89,9 Deg vs. 67.4 Deg) and, as expected, a shorter B-C bond. There is, however, no significant B-C p bonding. [on SciFinder (R)

Über einige Aluminiumbromid-Ether-Addukte: Strukturen in Lösung und im festen Zustand / Aluminium Bromide Ether Adducts: Structures in Solution and in the Solid State

Monoglyme forms a mol. 1:1 adduct with AlBr3 which dissocs. into the ions AlBr2(DME)2+ and AlBr4- in DME, CH2Br2, and CDCl3 as solvents. A hexacoordinated Al center is present in the solid adduct AlBr3.diglyme. The O and Br atoms are arranged in a meridional configuration as shown by x-ray crystallog. In soln. dissocn. occurs into AlBr2(diglyme)2+ and AlBr4-. Not unexpectedly, AlBr3 forms the adduct AlBr3.2THF with THF. The dioxane adduct AlBr3.diox is polymeric in the solid state and has a chain structure with pentacoordinated trigonal-bipyramidal Al centers. The Br atoms are arranged in a slightly distorted trigonal plane. In soln., the presence of tetracoordinated Al is indicated by 27Al NMR. AlBr3 cleaves one of the C-O bonds of 12-crown-4 leading to the dimer of w-bromo-tetra(ethyleneoxy)aluminum dibromide. This dimer contains pentacoordinated Al centers as proven by x-ray structure anal. The adduct of AlBr3 with 15-crown-5 is most likely an ionic compd., and is best described as [AlBr2(15-crown-5)]AlBr4 based on 27Al NMR and IR data. [on SciFinder (R)

Tetramethylpiperidine-alane adducts tmpH.AlX3 (X = Cl, Br, I) and tmpH.AlH2Cl. Synthesis, solution behavior, and x-ray crystal structures

2,2,6,6-Tetramethylpiperidine (tmpH) reacts smoothly with AlX3 (X = Cl, Br, I) and AlH2Cl.2THF to give the addn. compds. tmpH.AlX3 (X = Cl, Br, I) and tmpH.AlH2Cl, resp. These adducts of the secondary amine tmpH are stable and do not undergo intramol. elimination of HX or H2 with formation of the aminoalanes tmpAlX2 or tmpAl(H)Cl. In the solid state, tmpH.AlX3 (X = Cl, Br, I) and tmpH.AlH2Cl are tetracoordinated mol. adducts. While this is also true for solns. of tmpH.AlX3 (X = Br, I) and tmpH.AlH2Cl, the compd. tmpH.AlCl3 dissolves in CH2Cl2 as the salt [tmpAlCl3]-tmpH2 and the adduct tmpH.Al2Cl6, as is evident from its NMR spectra and from cond. measurements. This behavior is supported by a semiempirical AM1 calcn. [on SciFinder (R)

Functionalized 1,1-ethene dithiolates as ligands. Part 5. Synthesis and crystal structure of palladium(II) and platinum(II) complexes with dithioylidene barbituric acid ligands. Molecular structure of a 2,6-diaminopyridine-platinum(II) barbiturate complex

The 1,1-ethene dithiolato ligands (dithioylidene barbituric acids) react with L2MCl2 [M = Pd, Pt; L = PEt3, PBu3, 1/2 dppe, 1/2 (-)-DIOP, 1/2 2,9-di-Me phenanthroline] to give the 1,1-ethene dithiolato metal complexes L2M[S2C:cyclo[CC(O)NR1C(O)NR2C](O)]. I (R = H, R1 = H, L = PEt3) forms a 1:1 adduct (II) with 2,6-diaminopyridine. The compds. were characterized on the basis of their IR and NMR (1H, 13C, 31P) spectra. I (R = H, R1 = H, L = PEt3; R, R1 = H, L = 0.5 dppe; R = H, R1 = Me, L = PBu3) were further studied by x-ray structural anal. The barbituric unit in I (R = H, R1 = H, L = PEt3) undergoes self-assembly through multiple hydrogen-bonding with complementary 2,6-diaminopyridine yielding the supramol. complex II. [on SciFinder (R)

Supersilylverbindungen Der Borgruppenelemente, IV [1]. Supersilylelementhalogenide tBu3SIEX2 Und (tBu3Si)2Ex Mit E = Al, Ga, In: Synthesen, Eigenschaften, Strukturen [2] / Supersilylated Compounds of the Thirteenth Group, IV [I]. Supersilylelement Halides tBu3SIEX2 And (tBu3Si)2Ex with E = Al, Ga, In: Syntheses, Properties, Structures [2]

Water- and O-sensitive compds. (tBu3SiEX2)2, tBu3SiEX2.Do, and (tBu3Si)2EX (E = Al, Ga, In; X = (F), Cl, Br; Do = OR2, NR3) were synthesized by reaction of EX3 with tBu3SiNa in the absence or presence of donors. In addn., (tBu3Si)AlBr2, (tBu3Si)2InF, and tBu3SiInBr2 were prepd. by reaction of AlBr3 with (tBu3Si)2Zn or of (tBu3Si)2InIn(SitBu3)2 with AgF2 and HBr, resp. The adduct [tBu3SiAlBr2.AlBr3.1/2MgBr2]2 is formed from AlBr3 and (tBu3Si)2Mg(THF)2. Thermal decompn. of the compds. in soln. or in the gas phase leads to the formation of tBu3SiEX2 (from the dimers or the donor adducts) and of tBu3SiX. The Lewis acidity of tBu3SiEX2 against donors increases in the direction Do = Et2O < THF < NEtMe2. Dehalogenation of (tBu3Si)2ECl with tBu3SiNa(THF)2 in pentane at room temp. leads to clusters (tBu3Si)4Al2, (tBu3Si)3Ga2.bul., (tBu3Si)4In2, and (tBu3Si)3Ga2Na(THF)3, redn. of tBu3SiGaCl2 with Na or K in heptane at 100 Deg to the tetrahedral (tBu3Si)4Ga4. The structures of (tBu3SiGaCl2)2, (tBu3Si)2GaCl, and [tBu3SiAlBr2.AlBr3.1/2MgBr2]2 were detd. by x-ray structure anal. [on SciFinder (R)