CONHECIMENTOS GEOMÉTRICOS E ALGÉBRICOS DO TETRAEDRO FRACTAL 3D

A fractal is a figure that has a unique characteristic that will be present in the entire domain of the figure. There are several different types of fractals, some of which are constructed from a simple figure such as a triangle ofplane geometry or a tetrahedron of spatial geometry. From the initial construction of a two-dimensional fractal starting with an equilateral triangle and using Napoleon's Theorem, in this article, we present a construction of a new three-dimensional fractal using ideas similar to Napoleon's Theorem in a tetrahedron. Using concepts of plane and spatial geometry, this fractal can be built from a regular tetrahedron, and from the midpoints of its edges a new tetrahedron with a 1/2 ratio side is built in relation to the initial tetrahedron. After this construction, the characteristics of the infinite application fractal are studied, such as the sum of the surface areas and the total volume of the formed figure.

The Debt Narrative and the Credit Crunch of Democracy

This paper argues that the “debt narrative,” quite like the Rosetta Stone, is a historical, symbolic, and aesthetic way for us to decipher the interfaces between the three languages of economy, politics, and ethics. Debt narrative is not a simple figure of speech, literature, or thought; it acts, powerfully, in the real world. As in Europe today, the pressure of debts is related to a lack of credit for democracy and the future. Among the many examples of this relationship, the paper highlights Resistance Is Useless (Resistere non serve a niente), a novel by Walter Siti.

Figure-ground organization in visual cortex for natural scenes

Figure-ground organization and border-ownership assignment are essential for understanding natural scenes. It has been shown that many neurons in the macaque visual cortex signal border-ownership in displays of simple geometric shapes such as squares, but how well these neurons resolve border-ownership in natural scenes is not known. We studied area V2 neurons in behaving macaques with static images of complex natural scenes. We found that about half of the neurons were border-ownership selective for contours in natural scenes and this selectivity originated from the image context. The border-ownership signals emerged within 70 ms after stimulus onset, only ~30 ms after response onset. A substantial fraction of neurons were highly consistent across scenes. Thus, the cortical mechanisms of figure-ground organization are fast and efficient even in images of complex natural scenes. Understanding how the brain performs this task so fast remains a challenge.Significance StatementHere we show, for the first time, that neurons in primate visual area V2 signal border-ownership for objects in complex natural scenes. Surprisingly, these signals appear as early as the border-ownership signals for simple figure displays. In fact, they emerge well before object selective activity appears in infero-temporal cortex, which rules out feedback from that region as an explanation. Thus, “objectness” is detected by extremely fast mechanisms that do not depend on feedback from the known object-recognition centers.

Compact, Slotted, Printed Antennas for Dual-Band Communication in Future Wireless Sensor Networks

Inverted-F antennas (IFAs) are a primary choice to implement the radiating system of portable devices. A tried and tested idea can remain topical if proven useful in modern applications. This paper shows that printed IFAs (PIFAs) are capable of forming robust, compact, dual-band radiating systems for wireless microsensors with an adjustable spacing between bands. Reactive tuning was applied by inductively loading the structures with prefractal slots; inductive slot loading degenerates higher-order resonances and increases the fractional bandwidth (FBW). The current distributions revealed that most of the element area is used for radiation at both resonances. In radiation terms, the antennas provide satisfactory gains and high efficiencies (≥82%). A simple figure of merit is used to compare the performance of the three PIFAs head to head. Operation at 2.5 GHz and 5.5 GHz indicated that changes in slot geometry almost double the FBW. The proposed antennas serve both the 5.15–5.35 GHz U-NII and the 5.8 GHz ISM bands; at the lower band, their size is less or equal to the half-wavelength dipole. This study of dual-band antennas also showed that the aggregate FBW of a PIFA is bounded; by degenerating higher-order modes, the designer redistributes whatever bandwidth is available by the antenna itself to the desired bands.

A Heuristic Algorithm on Solving the Great Group Dividing of Figure

The problem of the great group of a figure is the famous NP-difficult problem. There exists an algorithm of solving the great group of figure or only applying to some of the special figure .There need time price is index level, and is low efficiency. It puts forward a kind of solving the minimax group partition algorithm with the most magnanimous nodes for elicitation information. This algorithm can be applied to any simple figure, and the maximum time complexity of algorithm is O(sn3).