5-Hy­droxy­indan-1-one

In the title compound (5HIN), C9H8O2, is perfectly planar as all atoms, except the H atoms of both CH2 groups, lie on a crystallographic mirror plane. In the crystal, mol­ecules are linked by strong inter­molecular O—H⋯O hydrogen bonds, forming an infinite chain along [100], generating a C(8) motif

A Study of Machine Learning Models in Epidemic Surveillance: Using the Query Logs of Search Engines

Epidemics inevitably result in a large number of deaths and always cause considerable social and economic damage. Epidemic surveillance has thus become an important healthcare research issue. In 2009, Ginsberg et al. observed that the query logs of search engines can be used to estimate the status of epidemics in a timely manner. In this paper, we model epidemic surveillance as a classification problem and employ query statistics from Google to classify the status of a dengue fever epidemic. The query logs of twenty-three dengue-related keywords serve as observations for machine learning and testing, and a number of machine learning models are investigated to evaluate their surveillance performance. Evaluations based on a 5-year real world dataset demonstrate that search engine query logs can be used to construct accurate epidemic status classifiers. Moreover, the learned classifiers generally outperform conventional regression approaches. We also apply various machine learning models, including generative, discriminative, sequential, and non-sequential classification models, to demonstrate their applicability to epidemic surveillance

(Z)-4-(2-Hy­droxy­benzyl­idene)-1-methyl-2-phenyl-1H-imidazol-5(4H)-one

In the title compound, C17H14N2O2, the asymmetric unit comprises two mol­ecules that are comformationally similar [the dihedral angles between the phenyl rings in each are 46.35 (2) and 48.04 (3)°], with the conformation stabilized by intra­molecular O—H⋯N hydrogen bonds, which generate S(7) rings. In the crystal, inversion-related mol­ecules are linked by pairs of weak C—H⋯O hydrogen bonds, forming dimers with an R 2 2(16) graph-set motif. Weak inter-ring π–π stacking is observed in the structure, the shortest centroid-to-centroid distance being 3.7480 (13) Å

(E)-4-[(4-Diethyl­amino-2-hy­droxy­benzyl­idene)amino]­benzonitrile

The title compound, C18H19N3O, displays an E conformation with respect to the C=N double bond. The dihedral angle between the mean planes of the two benzene rings is 24.49 (3)°. An intra­molecular O—H⋯N hydrogen bond generates an S(6) ring. In the crystal, mol­ecules are linked by nonclassical inter­molecular C—H⋯O hydrogen bonds to form an infinite one-dimensional chain along [010], generating a C(8) motif

1-Hy­droxy-11H-benzo[b]fluoren-11-one

The title compound, C17H10O2, is nearly planar, the maximum atomic deviation being 0.053 (2) Å. In the mol­ecule, an intra­molecular O—H⋯O hydrogen bond generates an S(6) ring motif. In the crystal, inversion-related mol­ecules are linked by pairs of weak C—H⋯O hydrogen bonds, forming dimers. π–π stacking is observed in the crystal structure, the closest centroid–centroid distance being 3.7846 (16) Å

7-Hy­droxy­indan-1-one

In the title compound, C9H8O2, an intra­molecular O—H⋯O hydrogen bond generates an S(6) ring. The dihedral angle between the mean plane of the S(6) ring and the benzene ring is 1.89 (2)°. In the crystal, inversion-related mol­ecules are linked by pairs of O—H⋯O hydrogen bonds, forming a cyclic dimers with R 2 2(12) graph-set motif. Weak inter­molecular C—H⋯Ocarbon­yl and C—H⋯Ohy­droxy hydrogen bonds link the dimers into chains along [010], generating two C(6) motifs that overlap three C atoms, forming R 2 2(8) ring motifs