Minutiae detection algorithm for fingerprint recognition

Among the main innovation prospects within the so-called Information Society, and in the framework of future communications systems, we find the design of database-access integral services, e-commerce and communication systems, together with remote control of terminals and devices, being the result of global services derived from last generation integration of mobile telephony and internet. Some features standout from such future services: security (guaranteeing user's privacy while in operation) in human-machine interacting (thus offering the same degree of spontaneity found in human communication through speech). To deal with security problems, the use of biometric-based technology (specifically through face, fingerprint, and speech) is proposed, because those technologies have reached a high degree of maturity, such as allowing successful application on secure authentication     

Optimum spectral bands for land cover discrimination

An experiment was undertaken to select the optimum spectral bands for the discrimination of land use/cover for proposed Indian Remote Sensing Satellite. A feature selection method was used for the discrimination analysis on the multiband data collected by Bendix 11-channel Modular Multiband Scanner over Tirupati test site of Chittoor district, Andhra Pradesh, South India. Of the various combinations of bands analysed, the optimum combination of four bands was defined as that one which provided the greatest divergence distances to discriminate the specific land covers in the test sites. On the basis of the above studies the optimum bands so chosen are 0.49–0.54 μm, 0.62–0.66 μm, 0.66–0.70 μm and 0.77–0.86 μm.     

IR circuit board and IC failure detection

This paper describes research and development efforts in the use of infrared (IR) laser beams for detecting failures in integrated circuits resident on printed circuit boards. This work involves taking advantage of the transparency of the silicon substrate of ICs to radiation in the near infrared (NIR) spectrum to devise a non-invasive method for imaging the component circuitry of the IC. The implication is that a means to see into the physical structure of an integrated circuit can be created by using lasers tuned to these wavelengths. While the silicon substrate is transparent to the laser, the circuit paths and devices embedded within the substrate are readily visible since their metallic composition is opaque to laser energy at this wavelength. A laser test fixture consisting of a 1064 nm continuous wave laser, CCD camera, and image acquisition board is used to generate images from flip-chip integrated circuits. Multiresolution image processing techniques are then applied to the resulting images to identify potential defects.     

Hematopoietic responses under protracted exposures to low daily dose gamma irradiation.

In attempting to evaluate the possible health consequences of chronic ionizing radiation exposure during extended space travel (e.g., Mars Mission), ground-based experimental studies of the clinical and pathological responses of canines under low daily doses of 60Co gamma irradiation (0.3-26.3 cGy d-1) have been examined. Specific reference was given to responses of the blood forming system. Results suggest that the daily dose rate of 7.5 cGy d-1 represents a threshold below which the hematopoietic system can retain either partial or full trilineal cell-producing capacity (erythropoiesis, myelopoiesis, and megakaryopoiesis) for extended periods of exposure (>1 yr). Trilineal capacity was fully retained for several years of exposure at the lowest dose-rate tested (0.3 cGy d-1) but was completely lost within several hundred days at the highest dose-rate (26.3 cGy d-1). Retention of hematopoietic capacity under chronic exposure has been demonstrated to be mediated by hematopoietic progenitors with acquired radioresistance and repair functions, altered cytogenetics, and cell-cycle characteristics. Radiological, biological, and temporal parameters responsible for these vital acquisitions by hematopoietic progenitors have been partially characterized. These parameters, along with threshold responses, are described and discussed in relation to potential health risks of the space traveler under chronic stress of low-dose irradiation.     

The position sensitive low energy detector on board the ZEBRA telescope

In order to improve the low energy capability (15 ÷ 150 KeV) of the balloon borne “ZEBRA” low energy gamma imaging telescope (150 KeV-20 MeV), a large area, high spectral resolution (5% at 60 KeV), low background detector has been designed and is now under development.It consists of two MultiWire Spectroscopic Proportional Counter (SPC), escape gated, that have a sensitive area of 6000 cm², and are placed above the large area array of sodiumiodide position sensitive elements.     

Convection and impurity distribution in crystal growth in low-gravity environments

Investigations conducted earlier by the authors have established that due to the steady-state field of body forces, convection is capable of giving rise to macroinhomogeneity in transverse impurity distribution in crystals. In the case of semiconductor materials the maximal value of this inhomogeneity is due to a weak convection in the melt, typical of low-gravity conditions. However, in addition to steady gravitational convection, other factors ignored previously, may also be employed in conducting experiments in low-g environments. The present paper discusses the results of theoretical studies of some factors influencing impurity distribution in the melt and the crystal.     

Conception of spacecraft centralized power supply

A reliable power supply for spacecraft is one of the central problems determining the future development of space technology. The traditional solution to this problem implies having an autonomous power plant on board each spacecraft. The most widely used are power plants with solar cells. However, there exists an alternative power supply concept of using a centralized power supply system (CPSS) and power transmission to the user satellites by laser or microwave beams. Use of a CPSS has a number of advantages. In particular, it allows the spacecraft to increase power supply level and service life as well as to decrease the spacecraft mass and cost. However, it sets new physical and technical problems associated with long distance power transmission and requires some changes in spacecraft structure and concepts. The feasibility study of CPSS development and use has to rely on existing or firmly forecastable technologies. An attempt of such an analysis has been done by a group of scientists at Moscow State Aviation Institute during 1994-1996. The very first results have already been published. This paper discusses new results obtained lately regarding a space based CPSS     

On the shape of rapidly rotating asteroids

By means of a statistical analysis of the rotational properties of asteroids, we define a class of large amplitude and short period objects (LASPA). A possible interpretation of their collisional evolution and present physical status, in terms of ellipsoidal figures of equilibrium, is proposed.     

Vertical distribution of SO2 in upper cloud layer of Venus and Origin of U.V.-absorption

It is shown that decline of spherical albedo of Venus toward the ultraviolet can be explained by the presence of two absorbing agents: a) SO₂, for which abundance is 10¹¹ cm^?3 at height 68 km and scale height is about 1 km; b) some unknown aerosol absorbent, possibly a 1% FeCl₃ admixture in a sulfuric acid concentrated solution. A mechanism of aerosol formation is proposed.     

Mass and heat exchange in liquids enclosed in containing walls at zero gravity

The dominant phenomena in miscible binary mixtures of melts are the four transport processes (thermal diffusion, heat transfer, concentration diffusion and diffusive heat transfer). In binary melts with no perfect solubility of the components in solid and liquid phase also internal Marangoni convections driven by interfacial forces seem to be possible.