The asymmetric unit of the title compound, C(14)H(17)N(3)O(3)·0.25H(2)O, comprises two independent organic mol-ecules and a water mol-ecule lying on a crystallographic twofold rotation axis with 50% site occupancy. In both independent mol-ecules, the cyclo-hexene rings adopt envelope conformations but superposition of the two molecules shows that the flap atoms point in opposite directions. In ...

The asymmetric unit of the title compound, [Mn(2)Cl(4)(C(30)H(36)N(6))], contains one-half of the formula unit; a centre of inversion is located at the mid-point of the mol-ecule. The two Mn(2+) ions are bridged by the dual tri-dentate N,N,N',N'-tetra-kis(2-pyridylmeth-yl)hexane-1,6-diamine ligand to form a dinuclear complex. Each Mn atom is five-coordinated in an approximately square-pyramidal...

In the title compound, 2C(4)H(7)N(2) (+)·C(4)H(2)O(4) (2-)·2H(2)O, the asymmetric unit consists of one 2-methyl-imidazolium cation, half a fumarate dianion and one water mol-ecule. There is an inversion center at the mid-point of the central C-C bond of the fumarate anion. In the crystal structure, mol-ecules are linked into a three-dimensional network by inter-molecular N-H⋯O, O-H⋯O and weak C...

A new algorithm is presented for detecting the global reflection symmetry of geometric objects. The works 2D and 3D objects which may be open or closed not contain holes. accepts a point cloud obtained by sampling object’s surface at input. points are inserted into uniform grid so-called boundary cells identified. centroid determined, testing axis/plane set through it. In this way, split two pa...

There are a large number of approaches to clustering problems, including optimization-based methods involving mathematical programming models develop efficient and meaningful schemes. Clustering is one the data labeling techniques. K-means partition algorithm that starts by selecting k representative points as initial centroid. Each point then assigned nearest centroid based on selected specifi...

The Exeter point of a given triangle ABC is the center perspective tangential and circummedial triangle. process from centroid serves as base for defining transformation with respect to ABC, which maps all points plane. We show that point, its image, symmedian, three exsymmedian are on same conic. general line fourth-order curve passing through points. each image can be four different aim deter...

in this paper, by considering a squint angle for synthetic aperture radar in the strip-map mode, a method is proposed for estimating parameters of a fixed acceleration moving target. non-zero doppler centroid and range-azimuth coupling in the squint mode add complexity to estimation equations of moving target parameters and cause doppler ambiguity. this, in turn, causes to lose the efficiency o...

In three studies, we investigated to what extent a geometrical representation in a psychological space succeeds in predicting typicality in animal, natural food and artifact concepts and whether contrast categories contribute to the prediction. In Study 1, we compared the predictive value of a family resemblance-based prototype model with a geometrical centroid model in which similarity is defi...