ANALYTICAL REPRESENTATIONS FOR THE TRUNCATED SPECTRAL CHARACTERISTICS OF THE FOUR-POINT COHERENCE FUNCTION OF A LASER BEAM IN A TURBULENT MEDIUM

New analytical representations for the truncated spectral characteristics of the four-point coherence function of a laser beam propagating in a turbulent medium are obtained. These representations are valid for any level of fluctuations of the refractive index in air. For two particular cases they turn into exact analytical representations previously derived by the authors with using of an integro-functional equation for truncated spectral characteristic of the four-point coherence function. A constructive procedure for obtaining approximate analytical expressions of the four-point coherence function of a laser beam propagating in a turbulent medium is proposed.

EXPRESS: Correlation and Difference Between Raman Spectral Characteristic and Feature Evaluation for Leukocytes and Tumor Cells

Tumor detection supported by Raman spectroscopy is becoming increasingly popular, yet the relevance of spectral variation and feature selection retains unclear. Here we determined the correlation and difference between spectral characteristic and feature evaluation for leukocytes and tumor cells. Some peaks were found to show noticeable spectral differences, and their intensity distributions were investigated, finding using Log-Normal distribution to describe Raman intensity pattern may be more appropriate. Further the importance of all Raman features was calculated, where some other peak features occupied the top status. By surveying the intensity variation and feature evaluation for those peaks, we concluded the peak with the highest importance does not correspond to the peak location with the most noticeable intensity difference in spectra. Moreover, the peak-intensity-ratio of I₁₅₁₇/I₇₁₉ associated with protein to nucleic acid level presented the maximum separation, thus it can be recognized as a special indicator to develop an alternative cancer detection. It is inspiring to introduce advanced statistical models into bio-spectroscopic fields but those intrinsic spectral variations rather than classification performance should be valued. Our explorations can provide possibilities to reveal the essences within tumor carcinogenesis based on Raman spectroscopy, further overwhelming the obstacles during the translation into clinical applications.

Iterative FFT-algorithms with high frequency resolution

В работе представлены три итерационных алгоритма быстрого преобразования Фурье с прореживанием по времени, имеющие алгоритмическую сложность O (N·R·log2N), где R — частотное разрешение спектральной характеристики (отношение длины набора частот к длине N набора отсчетов исходного сигнала). Алгоритмы отличаются способами организации вычислений: некоторые используют обратную перестановку битов, другие — дополнительные массивы. Приведены подробные вычислительные графы, а также блок-схемы разработанных алгоритмов. Полученные результаты можно использовать для улучшения отечественной электроники и программного обеспечения, а также включать в учебный процесс при подготовке инженеров в области цифровой обработки сигналов. This paper presents three iterative algorithms for fast Fourier transform with decimation in time; these algorithms have the algorithmic complexity O (N·R·log2N), where R is the frequency resolution of the spectral characteristic (the ratio of the length of the frequency set to the length of the N set of samples of the source signal). The algorithms differ in the way they organize calculations: some use reverse bit permutation, while the others use additional arrays. Detailed computational graphs and flowcharts of the developed algorithms are provided. The results obtained can be used to improve domestic electronics and software as well as may be included in the training process for engineers in the field of digital signal processing.

Color Characteristics and Stability of Anthocyanin in Fresh Thunbergia erecta Flower Extract

The main purpose of the present research was to evaluate the color characteristics of anthocyanin in Thunbergia erecta flower extract at various pH to know its potentiality as a food colorant. The fresh petal was macerated in 0.1 N HCl-Ethanol 96% (1:9) for an hour, filtrated and diluted in a buffer solution pH 1 to 12, then scanned by a spectrophotometer at 400 – 700 nm. The extract was almost colorless at pH 4 to 6 and show extremely low color stability at pH 7 and 8 (the half-life was 6.69 and 16.66 minutes, respectively). In contrast, the extract was very stable at pH 3. There was no significant color decrease after the extract being stored for 14 days at pH 3. An important spectral characteristic of Thunbergia erecta flower extract appeared at pH 7 to 10 by showing all the three colored species of anthocyanin. At pH 8, the red flavylium cation detected as λshoulder at around 537 nm, the purple quinonoidal base as the λpeak at 577 nm and blue anionic quinonoidal base as the λpeak at 614 nm. The unique spectral characteristic promoted the Thunbergia erecta flower as a potential anthocyanin-source to be used in the study of anthocyanin transformation in an aqueous system.

A Cost-Effective Illuminance Sensor for DaylightHarvesting Lighting Control Systems

A cost-effective two-wire industrial standard illuminance sensor (4–20) mA has been proposed. It can be used for daylight harvesting control of indoor illuminance and other applications. The basic sensor used is a cadmium sulphide (CdS) light dependent resistor, whose relative spectral characteristic almost corresponds to the human eye. The method of sensor calibration has been presented and static and dynamic performance characteristics of the sensor have been experimentally determined.

Fault Recovery Path Analysis of a Software Dynamic Image Based on a Fuzzy Control Algorithm

In order to improve the ability of software dynamic image fault detection, a software dynamic image fault recovery path detection algorithm based on a fuzzy control algorithm is proposed. A software dynamic image fault signal model of a software dynamic image fault was constructed by adopting an embedded feature extraction and a fuzzy control algorithm, and the dynamic image fault signal of the embedded software under the multi-load was subjected to frequency spectrum decomposition and blind source separation. The method comprises the following steps: (1) carrying out noise reduction processing on a software dynamic image fault signal by adopting a multi-dimensional wavelet decomposition method, (2) carrying out wavelet entropy feature extraction on the software dynamic image fault signal of the noise reduction output, and (3) combining the wavelet structural feature recombination method to carry out the recombination of the software dynamic image fault feature. The high-order spectral characteristic of the software dynamic image fault signal was extracted and the high-order spectral characteristic of the extracted embedded software dynamic image fault recovery path was automatically matched, and the automatic identification and detection of the fault part of the software dynamic image was realized.