Efficient Mining of Sequential Patterns in a Sequence Database with Weight Constraint

Sequence pattern mining is one of the essential data mining tasks with broad applications. Many sequence mining algorithms have been developed to find a set of frequent sub-sequences satisfying the support threshold in a sequence database. The main problem in most of these algorithms is they generate huge number of sequential patterns when the support threshold is low and all the sequence patterns are treated uniformly while real sequential patterns have different importance. In this paper, we propose an algorithm which aims to find more interesting sequential patterns, considering the different significance of each data element in a sequence database. Unlike the conventional weighted sequential pattern mining, where the weights of items are preassigned according to the priority or importance, in our approach the weights are set according to the real data and during the mining process not only the supports but also weights of patterns are considered. The experimental results show that the algorithm is efficient and effective in generating more interesting patterns

(Z)-3-(1-Benzofuran-2-yl)-2-(3,4,5-tri­meth­oxy­phen­yl)acrylonitrile

In the title compound, C20H17NO4, the double bond of the acrylonitrile group separating the 1-benzofuran moiety from the 3,4,5-trimeth­oxy­phenyl ring has Z geometry. The 1-benzofuran groups are π–π stacked with inversion-related counterparts such that the furan ring centroid–centroid distance is 3.804 (5) Å. The dihedral angle between the planes of the trimeth­oxy­phenyl ring and the acrylonitrile group is 24.2 (2)°

Smart Acknowledgement Distributed Channel Access Scheme for TCP in MANETs

TCP upon wireless networks is most challenging issue because of random losses and ACK interference. Also, TCP suffers from performance declination in terms of creating delay and overhead in network because of poor characteristics of wireless channel. In order to overcome these issues, we proposed a Smart Acknowledgement Distributed Channel Access (SADCA) scheme for TCP in MANETs. In the proposed scheme, first a separate Access Category (AC) for data less TCP acknowledgement packets is used and then it is assigned with highest priority. In this way, delay during transmission of packet can be reduced and also packet can be acknowledged immediately. Also, to increase the performance, delay window size can be adjusted by considering the parameters such as transmission rate, number of hops, and channel occupied ratio (COR). Hence the proposed scheme helps to avoid any kind of delay and overhead for sending TCP acknowledgemen

(Z)-3-(1H-Indol-3-yl)-2-(3,4,5-tri­methoxy­phen­yl)acrylonitrile

In the title compound, C20H18N2O3, the C=C bond of the acrylonitrile group that links the indole and the 3,4,5-trimeth­oxy­phenyl rings has Z geometry, with dihedral angles between the plane of the acrylonitrile unit and the planes of the benzene and indole ring systems of 21.96 (5) and 38.94 (7)°, respectively. The acrylonitrile group is planar (r.m.s. deviation from planarity = 0.037 Å). Mol­ecules are linked into head-to-tail chains that propagate along the b-axis direction by bifurcated N—H⋯O inter­molecular hydrogen bonds, which form an R 1 2(5) motif between the indole NH group and the two meth­oxy O atoms furthest from the nitrile group

Crystal Structure of (\u3cem\u3eE\u3c/em\u3e)-13-(pyrimidin-5-yl)parthenolide

The title compound, C19H22N2O3, {systematic name (1aR,4E,7aS,8E,10aS,10bR)-1a,5-dimethyl-8-[(pyrimidin-5-yl)­methylid­ene]-2,3,6,7,7a,8,10a,10b-octa­hydro­oxireno[2′,3′:9,10]cyclo­deca­[1,2-b]furan-9(1aH)-one} was obtained from the reaction of parthenolide [systematic name (1aR,7aS,10aS,10bR,E)-1a,5-dimethyl-8-methyl­ene-2,3,6,7,7a,8,10a,10b-octa­hydro­oxireno[2′,3′:9,10]cyclodeca­[1,2-b]furan-9(1aH)-one] with 5-bromo­pyrimidine under Heck reaction conditions, and was identified as an E isomer. The mol­ecule possesses ten-, five- (lactone) and three-membered (epoxide) rings with a pyrimidine group as a substituent. The ten-membered ring displays an approximate chair–chair conformation, while the lactone ring shows a flattened envelope-type conformation. The dihedral angle between the pyrimidine moiety and the lactone ring system is 29.43 (7)°

3-(2-Amino-1-methyl-4-oxo-4,5-dihydro-1H-imidazol-5-yl)-5-fluoro-3-hydr­oxy-1-methyl­indolin-2-one methanol hemisolvate

In the title compound, C13H13FN4O3·0.5CH3OH, mol­ecules are packed in the crystal structure by a series of O—H⋯N, N—H⋯O, N—H⋯F and O—H⋯O inter­molecular hydrogen bonds. The indole and creatinine units make a dihedral angle of 60.80 (4)°

3-(2-Amino-1-methyl-4-oxo-4,5-dihydro-1H-imidazol-5-yl)-3-hydr­oxy-1-phenyl­indolin-2-one ethanol solvate

In the title compound, C18H16N4O3·C2H5OH, mol­ecules are linked into chains by a series of inter­molecular N—H⋯O, N—H⋯N and O—H⋯O hydrogen bonds which stabilize the crystal structure. The indole and creatinine units make a dihedral angle of 56.45 (4)°. The title compound has two chiral centres. The crystal structure indicates the compound is racemic (RR and SS)

Crystal Structures of (\u3cem\u3eZ\u3c/em\u3e)-5-[2-(benzo[\u3cem\u3eb\u3c/em\u3e]thiophen-2-yl)-1-(3,5-dimethoxyphenyl)ethenyl]-1\u3cem\u3eH\u3c/em\u3e-tetrazole and (\u3cem\u3eZ\u3c/em\u3e)-5-[2-(benzo[\u3cem\u3eb\u3c/em\u3e]thiophen-3-yl)-1-(3,4,5-trimethoxyphenyl)ethenyl]-1\u3cem\u3eH\u3c/em\u3e-tetrazole

(Z)-5-[2-(Benzo[b]thio­phen-2-yl)-1-(3,5-di­meth­oxy­phen­yl)ethen­yl]-1H-tetrazole methanol monosolvate, C19H16N4O2S·CH3OH, (I), was prepared by the reaction of (Z)-3-(benzo[b]thio­phen-2-yl)-2-(3,5-di­meth­oxy­phen­yl)acrylo­nitrile with tri­butyl­tin azide via a [3 + 2]cyclo­addition azide condensation reaction. The structurally related compound (Z)-5-[2-(benzo[b]thio­phen-3-yl)-1-(3,4,5-tri­meth­oxy­phen­yl)ethen­yl]-1H-tetra­zole, C20H18N4O3S, (II), was prepared by the reaction of (Z)-3-(benzo[b]thio­phen-3-yl)-2-(3,4,5-tri­meth­oxy­phen­yl)acrylo­nitrile with tri­butyl­tin azide. Crystals of (I) have two mol­ecules in the asymmetric unit (Z′ = 2), whereas crystals of (II) have Z′ = 1. The benzo­thio­phene rings in (I) and (II) are almost planar, with r.m.s deviations from the mean plane of 0.0084 and 0.0037 Å in (I) and 0.0084 Å in (II). The tetra­zole rings of (I) and (II) make dihedral angles with the mean planes of the benzo­thio­phene rings of 88.81 (13) and 88.92 (13)° in (I), and 60.94 (6)° in (II). The di­meth­oxy­phenyl and tri­meth­oxy­phenyl rings make dihedral angles with the benzo­thio­phene rings of 23.91 (8) and 24.99 (8)° in (I) and 84.47 (3)° in (II). In both structures, mol­ecules are linked into hydrogen-bonded chains. In (I), these chains involve both tetra­zole and methanol, and are parallel to the b axis. In (II), mol­ecules are linked into chains parallel to the a axis by N—H⋯N hydrogen bonds between adjacent tetra­zole rings

Crystal Structure of (\u3cem\u3eE\u3c/em\u3e)-13-{4-[(\u3cem\u3eZ\u3c/em\u3e)-2-cyano-2-(3,4,5-trimethoxyphenyl)ethenyl]phenyl}parthenolide methanol hemisolvate

The title compound, C33H35NO6 [systematic name: (Z)-3-(4-{(E)-[(E)-1a,5-dimethyl-9-oxo-2,3,7,7a-tetra­hydro­oxireno[2′,3′:9,10]cyclo­deca­[1,2-b]furan-8(1aH,6H,9H,10aH,10bH)-yl­idene]meth­yl}phen­yl)-2-(3,4,5-tri­meth­oxy­phen­yl)acrylo­ni­trile methanol hemisolvate], C33H35NO6·0.5CH3OH, was prepared by the reaction of (Z)-3-(4-iodo­phen­yl)-2-(3,4,5-tri­meth­oxy­phen­yl)acrylo­nitrile with parthenolide [systematic name: (E)-1a,5-dimethyl-8-methyl­ene-2,3,6,7,7a,8,10a,10b-octa­hy­dro­oxireno[2′,3′:9,10]cyclo­deca­[1,2-b]furan-9(1aH)-one] under Heck reaction conditions. The mol­ecule is built up from fused ten-, five- (lactone) and three-membered (epoxide) rings with a {4-[(Z)-2-cyano-2-(3,4,5-tri­meth­oxy­phen­yl)ethen­yl]phen­yl}methyl­idene group as a substituent. The 4-[(Z)-2-cyano-2-(3,4,5-tri­meth­oxy­phen­yl)ethen­yl]phenyl group on the parthenolide exocyclic double bond is oriented in a trans position to the lactone ring to form the E isomer. The dihedral angle between the benzene ring of the phenyl moiety and the lactone ring mean plane is 21.93 (4)°