KEYWORDS: Photonic integrated circuits, Data compression, Statistical analysis, Associative arrays, Data processing, Data modeling, Computer programming, Data conversion, Binary data, Algorithm development
Basic coding methods for data compression in optical transmission are considered. A parallel-hierarchical transformation is proposed as a means of addressing the shortcomings of the methods considered. Pyramid-linear and pyramid-nonlinear coding at the functional level are given. The corresponding number of elements in the masks was calculated. The efficiency of the developed method compared to known methods was analyzed. The compression ratio and data compression conditions were determined.
The work is aimed at the development and experimental testing of the polarization-spectral method for analyzing the polycrystalline structure of the synovial fluid films of a human joint. comparing the sensitivity, specificity and accuracy of the methods of polarimetry in the diagnosis and differentiation of the above pathological conditions of the joints, we can conclude: the highest sensitivity, specificity and accuracy are demonstrated by the method of spectropolarimetry, sensitivity reaches 92 - 93%, specificity - 82 - 86%, and accuracy - 88% - 89%. additionally, the possibility of diagnosing the type of brain stroke by changing the polarization spectral characteristics is considered.
Authors considered the possibility of designing a non-invasive biomedical Raman spectrophotometer for the near infrared range using an ellipsoidal reflector as a collecting and focusing optical element to evaluation the biological media components, particularly glucose level. The technical solution for creating the spectrophotometer and its prototype are presented in this paper. The research of the experimental setup was observed faster and more sensitive photodetector reaction to the dynamic blood glucose changes of concentration. Practical testing was carried out by the Raman shift signal measuring on healthy volunteers at different time intervals with food intake associated. The experimental setup principles can be used to design a portable non-invasive glucometer or to quantitatively analyses the chemical composition of biological objects by changing Raman filters.
(Cu1-хAgx)7GeS(Se)5I mixed crystals were grown by vertical zone crystallization method, they are shown to crystallize in cubic structure ( F43m space group, Z=4). Refractive indices for (Cu1-xAgx)7GeS(Se)5I mixed crystals were obtained from the spectral ellipsometry measurements. Two anomalies of refractive index in the spectrum region from 300 nm to 1000 nm are observed. One of them corresponds to the band-to-band optical transition while another one to the interband Van Hove-Phillips singularity. The dispersion dependences of refractive indices for (Cu1-хAgx)7GeS(Se)5I mixed crystals in the transparency region is well described by Wemple and DiDomenico model. The influence of the cation Cu→Ag substitution and anion S→Se substitution on the optical parameters of (Cu1-хAgx)7GeS(Se)5I mixed crystals has been investigated.
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.
Dual-channel opto-electronic surveillance systems which operate in visible and infrared spectrum ranges are widespread. Their analysis and design needs suitable tools. A simplified physics-mathematical model of a dual-channel optoelectronic surveillance system was developed to determine energy resolution of the system. Noise equivalent brightness difference and noise equivalent temperature difference were used to define the ability of television and thermal imaging systems to detect objects. As an example of applying the model an algorithm of spectral channel selection depending on the conditions of surveillance was developed.
Synthesis of (Ag2S)x(As2S3)1-x superionic glasses for x<0.2 are carried out. The spectrometric studies of optical absorption edge in (Ag2S)x(As2S3)1-x glasses are performed in the temperature range 77-390 K. Optical absorption edge of (Ag2S)x(As2S3)1-x glasses with addition of Ag2S is strongly smeared and has an exponential shape.The influence of temperature and composition on the absorption edge behavior, parameters of optical absorption edge and electronphonon interaction as well as ordering-disordering processes in (Ag2S)x(As2S3)1-x superionic glasses are studied.
The article investigated the optical-frequency gas flow meter based on a transistor structure with negative differential resistance (NDR). A schematic diagram and design of an optical-frequency gas flow transducer that operates in the microwave range (0.85 to 1.5 GHz), which consists of a bipolar and field-effect transistor with a Schottky barrier, is proposed as a photosensitive element using a photoresistor. A mathematical model of an optical-frequency gas flow meter based on a transistor structure with negative differential resistance has been developed, which allows one to obtain the main characteristics of the transducer in a wide frequency range. Theoretically and experimentally, the possibility of controlling both the reactive component and the negative differential resistance from changes in control voltage and power is shown, it extends the functionality of optical transducers and allows linearization of the conversion function within (0.1 - 0.2)%. Experimental studies have shown that the greatest sensitivity and linearity of the conversion function of an opticalfrequency gas flow transducer lies in the range from 3 V to 3.5 V. The sensitivity of the developed optical-frequency gas flow transducer based on a transistor structure with NDR is 146 kHz/liter/hour, and the measurement error is ± 1.5%.
Among the various characteristics of infrared radiation, the degree of polarization is not often used in radiation analysis. The main reason is that polarization is less informative characteristic compared to others for most practical tasks. Also obtaining polarized radiation in infrared spectrum is relative complex and expensive act. In some cases, such as remote sensing, the improvement of spatial, radiometric and spectral resolution approaches it’s physical limit. It becomes relevant to obtain additional information of a different nature, such as polarization information. Modern infrared radiation polarizers based on diffraction gratings are quite expensive. The article explores the possibility of creating infrared polarizers based on a planeparallel plate, to which radiation falls at an Brewster angle. It is shown that the polarizer operating on transmittance will be more efficient than reflecting radiation polarizer, since it does not deviate the optical axis by a significant angle. Such a polarizer provides a polarization degree of 90% and a transmittance of about 50%.
This paper is devoted to the study of methods for improving the capabilities of measuring large data arrays through the use of optically-controlled transparent and Blockchain technology. The research results are presented with the help of the developed method, which made it possible to evaluate the effectiveness of the proposed improvements ie the speed of data processing large sizes. In this paper, the main areas of application of the blockchain technology, its main properties are analyzed. During the work, the prospects for the development of this topic were determined, the main principle of the work of blockchain technologies and optically-controlled transparent. It has been determined that one of the main functions of the blockchain is its parallel processing and data analysis. With the help of the technology of the blockchain and with the help of optically controlled banners, a matrix filled with certain information was processed, we transformed each data cell with the hash-function into a hash-code. Also, the processing time and the hash function were investigated.
KEYWORDS: Image filtering, Image processing, Information technology, Image compression, Video, Image quality, Video surveillance, Video compression, Optical filters, RGB color model
This work is devoted to development of information technology for real noise image filtering and storing obtained under low light condition. The information technology is designed to reduce the size of the image (video) archive, through the use of image processing methods. The structure of information technology is proposed. It includes input data, color models, image processing methods (filtering, compression, blocking effect reduction, coding and transmission), algorithms and software. The developed information technology depending on image type, task and result requirements performs image processing with appropriate filtering methods and has the possibility of encoding and transmission obtained images. The information technology allows reducing the size of the video archive in a video surveillance system with MPEG-4 (XVID) and H.264 video codec, while maintaining acceptable quality.
KEYWORDS: Transistors, Electrons, Field effect transistors, Transducers, Resistance, Semiconductors, Microelectronics, Diffusion, Active optics, Radio optics
The paper deals with the fundamentals of the theory of photoreactive effect in bipolar and field-effect transistor structures. Photoreactive properties of semiconductor devices are widely used in a variety of radio electronics devices. Therefore, the study of these phenomena in bipolar transistor structures with negative resistance, allows us to create new sensory devices, which have better parameters than existing ones. The method of construction of radiomeasuring microelectronic transducers is offered on the base of photoreactive effect in sensing bipolar and field transistor structures, that has established premises for embodying transducers of optical radiation with a frequency output signal.
Photonic crystals, the artificially created multilayer structures with dielectric permittivity and geometric dimensions varying with a period comparable to the wavelength, were studied by the calculation of light interference in a given multilayer system. The developed calculation programs using the matrix method made it possible to obtain the optical characteristics (reflection, transmission, etc.) for any multilayer coatings. The focus was on the analysis of the influence of defects associated with the violation of the layer periodicity. Spectral dependences of the reflection coefficient, argument of Chebyshev polynomial and argument module of the Chebyshev polynomial are given. The calculation of the optical characteristics of multilayer coatings by the matrix method provided the opportunity to identify the presence of barrier zones for periodic and defective systems and to propose their use as the contrast or narrowband interference filter.
The results of an experimental study of obtaining approximate solutions of the multidimensional knapsack problem are presented in the paper. Three methods for obtaining these solutions are considered, based on branch-end-bound algorithms with a one-sided branching. One hundred test tasks of different dimensions have been solved for each method. The estimation of the approximation of the solutions obtained in relation to the best solution is provided, as well as the estimation of the computational complexity.
The paper specifies the achievable Bragg wave shift generated by pre-stressing the optical fibre in the phase mask writing process. The maximum possible shift results from the mechanical strength of the optical fibre to axial stress. Two methods are also proposed for the production of Bragg gratings with a controlled Bragg wavelength. The experiment was performed for the SMF28 fibre subjected to the hydrogenation process. The FBG fabrication was carried out in the excimer laser system using the phase mask method.
The article presents the possibilities of defects detection in the form of welds of leading steel elements, using the fiber Bragg gratings (FBG). Measurement of sensitivity to force change is ensured by shifting the FBG spectrum. Two steel samples of the same dimensions were used for the tests. The first one lacking significant defects in its structure, while the second one has been cut in the middle and it has been welded. FBG has been glued to the sample over its entire length. The results of measurements in the form of basic characteristics of the described stress sensor are presented below.
An optical method for determine the quantity of water in milk using the visible optical radiation range is proposed. On the basis of theoretical and experimental studies of the water-milk solution spectral characteristics the proposed method mathematical model was created. The mathematical modeling of passing of the visible range optical radiation through a water-milk solution on certain thickness of the solution layer is carried out. As a result of the modeling, the dependence of the output voltage of the photo-receiver based on a pair of photodiode-operating amplifier from the relative mass fraction of milk in the water-milk solution and the wavelength of the optical radiation in the visible range is obtained.
KEYWORDS: 3D image processing, Visualization, 3D visualizations, 3D displays, Computing systems, Ray tracing, 3D modeling, Computer architecture, Prototyping, Systems modeling
The article considers experience of creating of system of realistic 3D stereo visualization by raytracing method on GPU basis. The basic organization of such 3D stereo visualization systems and parallel architecture of computing systems for realistic synthesis of stereo images by raytracing method were proposed. The developed architecture of 3D stereo visualization systems is able to solve the problem associated with middle 3D scene complexity image synthesis in real-time mode.
The spectral method of the jitter parameters estimation in fiber optics transmission systems is being suggested. The suggested method is featured with high accuracy at the expense of the statistical stability improvement of the results, obtained during the implementation of overlapping fast Fourier transform.
For nowadays the main goal for using the sensors are the investigations the new gas sensitive materials. Optical gas sensors are characterized by most of the high response. Such sensors distinguished by the high sensitivity, selectivity and stability and have long-term operation1. The principle of operation is based on the absorption of NH3 gas by sensitive element of primary transducer and changing the spectral characteristics. Principle of gas sensor operation is based on the registration of shift of the wavelength minimum in spectral characteristics of cholesteric-nematic mixture (CNM). In paper as sensitive material used the CNM on the basis of BLO-61 cholesteric liquid crystal (CLC) with 5CB nematic liquid crystal (NLC) doped by single and multiwall carbon nanotubes. The optimal nanocomposite structure composition to obtain the maximum value of spectral sensitivity coefficient was determined. In paper was found the increasing the nanotubes concentration in CNM leads to increasing the spectral sensitivity coefficient independently of 5CB concentration in CNM, but the maximum nanotubes concentration was chosen to take in to account the optical transparency of experimental samples. Gas sensitive material on the basis of cholesteric-nematic mixture doped carbon nanotubes for optoelectronic NH3 gas sensor.
The aim of this work is the development of a reference source of subnanosecond pulses based on SiC breakdown LEDs. The micro-alloy technology of p-n junctions based on SiC-6H with a diameter of about 50 microns has been developed. The capacity of such structures does not exceed 10-20 pF. The high stability and current overload resistance of the samples were provided by the uniform microplasma breakdown structure. The breakdown electroluminescence spectrum of the investigated samples was flat and covered the range of 400-800 nm and the relaxation time did not exceed 0,25 ns (a time resolution of measuring system). The radiation power was about 10-6 W/A.
To prepare this paper, near 100 different LPGs were researched with simulations. Length (2cm-4cm), period (100μm- 400μm), deep of refractive index modulation (0,0001-0,0004) of LPGs and their apodization was the input variables. The changes of peaks dynamic, their full width at half maximum, location (resonance wavelength) and noise was observed. On the basis of this, transient characteristics describing searched dependences was designated.
KEYWORDS: Information technology, Picosecond phenomena, Statistical analysis, Data modeling, Databases, Instrument modeling, Data storage, Data processing, Intelligence systems, Data mining
The article contains information technology of clustering problem situations in computing and office equipment, which is based on an information model of clustering and modified clustering methods FOREL and K-MEANS such situations.
The use of the polarimetry techniques for display and study of biological tissues has gained increasing interest in recent years. This interest is related mainly to the non-invasiveness, relatively low cost, and ease of application among other characteristics. However, for full use of these advantages, the calibration methods must ensure the minimization of the effects of uncertainties related to the optical element positioning and the noise in intensities measurements.
Neurosurgical intervention is a very complicated process. Modern operating procedures based on data such as CT, MRI, etc. Automated analysis of these data is an important task for researchers. Some modern methods of brain-slice segmentation use additional data to process these images. Classification can be used to obtain this information. To classify the CT images of the brain, we suggest using local histogram and features extracted from them. The paper shows the process of feature extraction and classification CT-slices of the brain. The process of feature extraction is specialized for axial cross-section of the brain. The work can be applied to medical neurosurgical systems.
KEYWORDS: Control systems, Error analysis, Manufacturing, Fuzzy logic, Decision support systems, Raw materials, Visual process modeling, Neural networks, Algorithm development
Conditions of diversification of enterprise products are involving for changes of higher levels of management hierarchy, so it’s leading by tasks correcting and changing schedule for operating of production plans. Ordinary solve by combination of enterprise resource are planning and management execution system often has exclusively statistical content. So, the development of decision support system, that helps to use knowledge about subject for capabilities estimating and order of operation of production object is relevant in this time.
This article gives a detailed introduction of the operation of optical switches, as well as the problems that arise, and according to this, the possible solutions in theoretical approaches, in the next paper will be made a simulation to compare the new design.
The paper evaluated the diagnostic value of laser photoplethysmography when examining patients with chronic lower limb ischemia. A statistical analysis of the research results was made, and diagrams of relationship between the degrees of ischemia and blood flow are presented.
This paper presents the method of bending force and temperature measurement. For this purpose, a station with a thermal chamber has been designed and a bracket used in further measurements on which Bragg gratings have been mounted. The performance of simultaneous measurements of force and temperature was possible through the use of an appropriate layout of the sensor. The method of indirect measurements was used, using information deriving from the spectrum of the uniform Bragg gratings, placed on the cantilevers. The measuring system scheme was proposed for measuring sizes measured in the form of bending force, acting in two directions, perpendicular to the grating axis. The increase in the sensitivity of the change on the force is obtained in relation to the system, in which only information on the width of the spectrum of one of the gratings would be used. A change in the spectral width value was observed along with the increase in bending forces from 0 to 10N for two cantilever beams schemes. The head of the sensor can reach larger physical sizes, in exchange enabling a measurement of force and temperature in many places, thus determine the distribution of force and temperature.
The paper presents application of fiber optic flame monitoring system and its signals analysis for estimation thermal power and air-fuel ratio of single burner that are hard to determine. To achieve this, several combustion tests were conducted for nine different settings of the laboratory combustion facility, where thermal power and excess air coefficient were kept constant and set independently for known biomass content. Thermal power was regulated by adjusting fuel flow rate knowing the heating value of the known fuel blend. The fiber optic probe was capable to monitor several zones of the flame located along the axis of the flame. The k-NN regression algorithm was applied to determine thermal power and air-fuel ratio.
This paper presents properties of all-optical bistable fibre switch using two fibre Bragg gratings and rare earth elements doped optical fiber. It is not possible to obtain bistable properties at low switching power level in case of a single fibre grating. In this article the method of optical switching that uses all-optical switch has been proposed. It has been achieved by varying the refractive index of nonlinear optical material as a result of light signal amplitude changes. Presented optical bistable device can be used both in contemporary optically switched networks as well as in optoelectronic sensors, owing to their high achievable resolution.
This paper presents properties of all-optical bistable fibre switch using two fibre Bragg gratings and rare earth elements doped optical fiber. It is not possible to obtain bistable properties at low switching power level in case of a single fibre grating. In this article the method of optical switching that uses all-optical switch has been proposed. It has been achieved by varying the refractive index of nonlinear optical material as a result of light signal amplitude changes. Presented optical bistable device can be used both in contemporary optically switched networks as well as in optoelectronic sensors, owing to their high achievable resolution.
A microfacet distribution function is presented. This function can be used to calculate the microfacet distribution term in BRDF models. The function differs from other well-known microfacet distribution functions like Blinn or Beckmann distributions in that it doesn`t use special functions like acos, tan, exp, pow and thus has lower computational complexity.
In this work the conception of the fiber Bragg grating (FBG) application in the capacity of the temperature distribution sensor, on the grating length, is presented. In the method of temperature distribution measurement, by using of FBG element, the key issue is an estimation of the grating periods distribution (and connected with this estimation - temperature distribution) from measured grating transmission spectrum (an inverse problem). The article presents measurements results used for evaluation of selected methods for solving an inverse problem, which can be used in temperature distribution recovery from FBG spectrum. We have also presented utility evaluation results of the selected methods for numerical solution of the inverse problem for temperature distribution recovery.
The results of the fiber Bragg grating reconstruction problem were introduced in this work. This process was conducted
by using of Genetic algorithm. The proposals of the ways of modeling structures of fiber Bragg gratings by the use of
the object-oriented programming and by the use of the direct and inverse problem were introduced in this article.
In this article the proposals of the ways of modelling structures of fiber Bragg gratings by the use of the object-oriented
programming and by the use of the direct and inverse problem were introduced. The results of the inverse
problem solution, done for Bragg gratings, were also introduced in this work. This process was conducted by using of
local optimization algorithms.
In this paper, we have presented a reliable simulation of algorithm for the recovery of the fiber Bragg grating (FBG) parameters from their reflection spectrum. An accurate method for synthesizing the physical parameters of the fiber Bragg grating has been proposed and demonstrated on the bans of its reflectivity. The method is based on gradient optimization algorithms and can be applied over each type of gratings (uniform, apodized, chirped, phase shifted). We have proposed a new technique, which has overcome some of existing disadvantages and restrictions by using information about the reflection characteristics from grating, which we have examined, and also using the transmission characteristics. As an example, the proposed technique may be successfully applied to synthesize and characterize our experimental grating which is uniformed, apodized and linearly chirped, from FBG measured reflectivity. This method could be applied for distribution strain and temperature sensing applications if only we have some previous information about the
unstrained FBG and also if the possible strain profiles are known. Our algorithm for the synthesis of FBGs from reflectivity has no limitations in parameter space. We don't have to reduce the problem to small number of parameters. In most of practical cases, our technique would fast lead to accurate synthesis results. The proposed method can efficiently lead to optimal solutions and at the same time it takes into account various requirements of the examined grating. This study and simulations are supported by initial laboratory experiments, and this allow us to suppose, that there is a real possibility of complete, fast, and accurate characterization (including phase characterization) of FBG structures from reflectivity measurements.
In this paper a FBG (Fiber Bragg Grating) sensor for measuring temperature and temperature distribution is presented. We have used a phase retrieval algorithm for the temperature measurement. There is presented a method for obtaining the distributed temperature distribution along a fiber Bragg grating by measuring the reflectivity spectrum. We have also a priori knowledge about the complex coupling coefficient's magnitude.
In this article initial works to the point of examination of Fiber Bragg Grating (FBG) sensors are presented. We describe this works in the context of use FBG elements in construction of temperature sensors. We have compared theoretical assumptions and studies with practical results, which had been received in first lab examinations.
In this paper, a review is given on the principles of optical fiber Bragg grating (FBG) sensors and their applications a strain sensors. Since the discovery of photosensitivity in optical fibers there has been great interest in the fabrication of Fiber Bragg Gratings within the core of a fiber. The ability to inscribe Bragg gratings in these photosensitive fibers has revolutionized the field of optical fiber based sensor technology. This work reviews the achievements about the FBG as a strain sensor and describes the potential applications of these sensors. The present paper discusses some of the parameters of gratings, which are important for sensor's constructions. These sensors are constructed on the basis of elasto-optic effects where the deformation is coded in wavelength.
A new way leading to estimate Fiber Bragg Gratings (FBG) parameters is presented. We describe calculating influence of accuracy of FBG execution on their basic characteristics. In this paper we report and present an FBG element as an optical fiber sensor. An FBG quality characterize two mainly essential parameters. There are Full Width at Half Maximum to stand for FWHM (also presented as Δλ) and reflection index to stand for R. We examine influence of accuracy of FBG with reference to following quantity: modulation of the refraction index Δn and the grating period Λ. On the basis of well known analytical relationship which describe FWHM and R we have estimated influence of FBG construction on above parameters. After obtain final analytical dependences we make suitable graphs to depict all calculations.
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