Small satellite platforms with television cameras onboard became popular in recent years. Many of these devices are non-commercial and are student-built. The small budget of such a mission suggests mainly educational use. Meanwhile, high-quality pre-flight radiometric calibration of onboard equipment will significantly expand the range of remote sensing tasks performed by the mission. This article describes a method and equipment for measuring the main energy characteristics of television cameras - signal transmission function, zone characteristics, noise signal of matrix detector. The proposed equipment provides a high dynamic range with good accuracy and has a low cost.
Thermal evaporation technique was used to deposit (Ga0.1In0.9)2Se3 thin films. The optical transmission spectra of (Ga0.1In0.9)2Se3 thin film were studied in the temperature range 77-300 K. Temperature behaviour of the Urbach absorption edge as well as the temperature dependencies of the energy pseudogap and Urbach energy were investigated. The influence of different types of disordering on the optical properties of (Ga0.1In0.9)2Se3 thin film was discussed. Optical parameters of (Ga0.1In0.9)2Se3 thin film and single crystal were compared.
The article describes the foundations of using method of using laser Doppler flowmetry in evaluation of the state of blood microcirculation system in students, future software engineers. By the method of laser Doppler flowmetry (LDF) individually-typological features of indicators of tissue blood flow in conventionally healthy adolescent students aged 17-20 years have been studied. Due to the results of research 3 types of LDF-grams have been defined: aperiodic, monotonous low amplitude, sinusoidal type with high perfusion. Among the examined students, future engineersprogrammers different frequency of appearing microcirculatory types with predominance of normoemic type with characteristic “aperiodic” LDF-gram has been found.
An improved mathematical model of artificial neuron with active generation of action potentials was developed, and the behavior of an artificial network consisting of thousands of described neurons was investigated. The passive part of the neuron consists of soma and asymmetric dendritic branches that provide multi-stability. The active component of the neuron is described with the help of a simplified non-linear neuron model with mechanisms for the spiking generation. The presented model reproduces all types of electrical generations of known biological neurons, e.g. neocortical. The model combines the biological similarity of the Hodgkin-Huxley type dynamics and the computational efficiency of integrative-spiking neurons. It is shown that switching between different modes of generation is possible under the condition of structural three-stability of the neuron in common. A neural network consisting of multi-stable neurons is capable of generating synchronous regular spikes if all neurons in the network are in a similar electrical state. In the case where a part of the neurons at non-similar stable condition, the network generates asynchronous regular spikes, without adding any synaptic plasticity mechanisms or modulating stimulation processes. The obtained model can be used for studying the features of real-time data processing by artificial neural networks, which can be used for such modern tasks as recognition and classification of biophysical signal patterns or for the development of elements of artificial intelligence.
An inscription of a Bragg grating on a typical telecommunications fibre is difficult to obtain. In inscribing a structure, special fibres with an increased germanium content or classic fibres subjected to the hydrogenation process are used. The following article analyses the dependence of the hydrogen pressure on the parameters of the structures produced, such as grating reflectivity, Bragg wavelength or full width at half maximum (FWHM). The article also verifies how the pressure in the hydrogenation process affects the time of inscribing structures. Two types of fibre were subjected to photosensitisation: the classic one and one with a higher content of germanium. The hydrogenation process was performed at three pressures of 50 bar, 100 bar and 190 bar. Hydrogenation took place under the ambient temperature conditions of the room in which the chamber was located.
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