Abstract: A frequency response estimation method to compensate for channel differences in distributed acoustic sensing systems include two compensation algorithms, online and offline, and these two compensation algorithms are presented to generate standardized mel-frequency features, as an input to neural networks. By this scheme, the variance of mel-frequency feature space is decreased and normalized among different channels, which enables to use less training data and smaller architectures for classification and anomalous event detection tasks.

Abstract: A method that detects the location of undesired levels of signal loss for DAS systems. In the method, raw data is received from a DAS system with dual photodetector. Statistics are obtained from the received raw data, then processed according to the dual photodetector. The obtained statistical data are reconstructed to remove noise and the reconstructed signal is used to form the power statistics of the DAS signal in each channel. The power statistics are expected to be linearly decreasing with the distance from the sensor. A change detection algorithm is developed to detect the possible undesired levels of signal loss and to find the location of the signal loss.

Abstract: A method for effective Height Above Terrain (HAT) analysis display in avionics software is provided. The method enables the display of height above terrain analysis with high performance by the usage of high resolution data. The method includes preparing a shader program, mapping program variables, compiling the shader program, activating the compiled shader program and executing all graphics processing instructions; transferring elevation tiles and running the shader program; transferring an aircraft altitude; and running the shader program, comparing each cell's elevation value to the aircraft altitude and interpreting the difference in values, and displaying a colour value.

Abstract: A cooling case provides cooling of electronic cards. The cooling case provides efficient cooling of electronic cards found in military electronics packaging, and includes a cold plate having a fin structure.

Abstract: A test method for determining impact effects and abrasion effects of particles such as rain, hail, dust, ice, sand, and micrometeoroids at speeds above Mach, i.e., higher than the speed of sound. The test method includes the steps of placement of balls in capsules, firing the capsules with a rifle firing system, hitting of the fired capsules and/or the balls to a target inside a firing range, recording the impact effects during a firing with a recording system, determining a durability and a lifetime of a test sample of test samples by calculating a number of the balls hitting the target and a number of shots providing an effect.

Abstract: A broadband choke inductor is used in a bias circuit for broadband high-power distributed amplifiers.

Abstract: A method for fabricating multi-layer ceramic broadband radome includes thermal-spraying layers of coating materials on the radome. The assembled structure exhibits tuned RF transparency response depending on the thickness and the dielectric constant of the deposited layers. Sub-micron thick ceramic layers, which are essential for broadband performance and hard to produce due to their fragile nature, can be deposited on big and complex objects by a fast and automated process.

Abstract: The resulting two-sided ISI effect can be migrated to an equivalent noncausal communication channel. Then, a method for mitigating two-sided ISI and compensating the noncausal channel effect is proposed. The method includes insertion and removal of CP and CS. When CS and CP are inserted at transmitter and removed at receiver in block transmission-based communication systems, it is possible to generate a circulant convolution matrix for noncausal communication channel. In addition, the method includes equalization of a noncausal communication channel in block transmission-based communication systems when the channel state information is available at the receiver.

Abstract: A method is based on the user-specific frozen bit patterns of polar codes assigned to users. At the transmitter, the binary-valued user-specific frozen bit pattern sequences to be used in frozen bit locations are determined for each user, the information bits of each user are encoded using a polar encoder, and the binary-valued user-specific frozen bit patterns are used in frozen bit locations during encoding operation to improve the performance of the downlink multi-user MIMO system. Coded bits are mapped to symbols to be transmitted, and the symbols are mapped to the MIMO layers. Then, multi-antenna precoding is applied and baseband-to-RF processing is performed onto the precoded symbols to transmit the signal. The signal of all users is transmitted at the same time-frequency resources using transmit antennas. Each receiver receives the transmitted signal which is transmitted through respective downlink channels. Each user performs RF-to-baseband processing to their respective received signal.

Abstract: A method for constructing multiple ceramic layers by winding continuous ceramic filaments of identical composition to prepare multilayer RF-transparent structures is provided. In the method, identical continuous ceramic filaments are wound to construct a layer with specific dielectric constant according to patterns, characterized by the winding angle, winding density/inter-fiber aperture and winding count/layer thickness. Layers with same or different dielectric characteristics forms a sandwich design to fulfill the desired mechanical, thermal and electrical requirements.

Abstract: A method for constructing multiple ceramic layers by winding continuous ceramic filaments of different compositions to prepare multilayer RF-transparent structures is provided. In the method, different continuous ceramic filaments are braided to construct layers with specific dielectric constants and braiding count/thickness. Layers with same or different dielectric characteristics forms a sandwich design to fulfill the desired mechanical, thermal and electrical requirements.

Abstract: A method is provided for acoustic source direction of arrival estimation and acoustic source separation, via spatial weighting of the dictionary based display of the steered response function calculated for a certain number of directions from spherical harmonic decomposition coefficients obtained from microphone array recordings of the sound field. The usage of spatial band limited functions of plane waves to represent more complex directional maps of the sound field constitutes the algorithm. These functions are calculated for pre-defined directions on an analysis surface (such as a sphere). The directions of arrival of sound sources are calculated with the same method in order to group source estimates to localize sound sources. Thereby, directions of arrival can be obtained from the recordings of the sound sources captured by means of a microphone array and following this, sound sources can be separated by using this direction information or predetermined source arrival directions.

Abstract: A method for constructing a plurality of ceramic layers by winding continuous ceramic filaments to prepare RF-transparent structures is provided. Dielectric properties of each layer of the plurality of ceramic layers are characterized by an inter-filament spacing, a filament count and thickness. Once the plurality of ceramic layers are constructed, a structure is removed from a winding surface, wherein the winding surface is a mandrel, infiltrated with a resin in a separate set up and fired.

Abstract: A dual-mode filter with a cross iris is provided. The cross iris is adjustable, and the dual-mode filter includes at least one resonator at both sides of the cross iris. The dual-mode filter includes tuning screws located on the cross iris in line with vertical and horizontal slots, changing a coupling level of the vertical and horizontal slots and changing a bandwidth. Minor design or production based errors are fixed by configuring the dual-mode filter with desired technical parameters.

Abstract: A method for a multi-channel acoustic event detection and classification for weak signals, operates at two stages; a first stage detects a power and probability of events within a single channel, accumulated events in the single channel triggers a second stage, wherein the second stage is a power-probability image generation and classification using tokens of neighbouring channels.

Abstract: A slim type universal joint used to transmit torque generated by an output/driving shaft and/or rotary motion on rotation axis on the system of engine vehicles connected thereto into the output/driving shaft of different axis and allowing independent locking of rotation axis. The slim type universal joint includes a locking hole, a central-lower part, a central-upper part, pin holes, an outer-lower part and an outer-upper part, a first short cap pin, a second short cap pin and a long cap pin.

Abstract: A method for minimizing center frequency shift and linearity errors encountered in YIG filters, comprising the following steps: automatically generating data packages in test unit depending on the user request or containing all filter characteristic states and transmitting them to the driver circuit, adjusting the desired voltage level by means of the digital to analog converters contained in the structure of the data packages received by the driver circuit, and transmitting the adjusted voltage level to the YIG filter, measuring filter characteristics (scattering parameters) corresponding to the data packages transmitted to the YIG filter in the analyser, in order to calculate the center frequency shift of the filter, determining the center frequency and linearity calculations, and recording the characteristic features measured by the analyser in the test unit.

Abstract: A hardware complexity reduction method for successive cancellation list decoders (SCL) is provided. In path pruning stages of an SCL decoding, L paths with smallest path metrics out of 2L candidate paths are chosen as surviving candidate paths as in a conventional SCL algorithm. Moreover, path indexes of L surviving candidate paths are provided in a sorted manner according to indexes at an output of a sorter module. After a path pruning, instead of L-to-1 multiplexers, (L/2+1)-to-1 multiplexers are deployed to perform copying operations of any required elements stored in dedicated registers of the L surviving candidate paths.

Abstract: A noise elimination method for detection applications to increase performance, robustness and efficiency is provided. The noise elimination method including the following steps of; initialization; candidate generation; obtain sensor data; obtain a transformation matrix; warping candidate signals into a Cumulative Signal Frame (CSF); get a next candidate; process a last candidate; query a set handler; add the candidate signals into the set handler; warp the candidate signals onto the CSF; add the candidate signals to the CSF at a warped position; process the CSF; interpret the CSF and generate target candidates; detect decisions and terminate.

Abstract: Production of multilayered ceramic missile radomes with wide frequency band and high electromagnetic permeability through three-dimensional printing technology and the use of glass inter-layer materials to minimize defects caused by thermo-mechanical incompatibility of adjacent layers during sintering are provided. The three dimensional printing of the multilayered ceramic missile radomes provide an automated, operator-independent and repeatable manufacturing technique to produce wide band ceramic missile radomes.