Special Coverage


Non-Binary Protograph-Based LDPC Codes for Short Block Lengths

The constrained protograph-based LDPC codes are a new class of codes proposed for low-complexity implementation of decoders. NASA’s Jet Propulsion Laboratory, Pasadena, California Short block codes are in demand by international space agencies for transmission of command and control data to spacecraft in the uplink channel. Codes that outperform currently used binary codes with the same block lengths and code rates are desirable. A design method constructs non-binary LDPC (low-density parity-check) codes both for unconstrained non-binary protograph-based codes and the new class of constrained protograph-based codes. The non-binary short block codes outperform the binary version by at least 1 dB for the same block size and code rate.

Posted in: Information Sciences, Electronics & Computers, Briefs


Method Resolves Algebraic Loops While Improving Accuracy and Reducing Runtime

Higher accuracies are achieved while running at the lower base sample rate. Armstrong Flight Research Center, Edwards, California A method has been developed for resolving algebraic loops that occur in closed-loop systems when using MathWorks Simulink modeling and simulation tools. This variable fidelity method improves accuracy and reduces runtime significantly for users of Simulink Coder applications. The method improves the Simulink Coder tool’s ability to more efficiently and quickly generate C code based on algorithms modeled in the simulation tool. By replacing transfer functions that require high sampling rates with embedded function integration schemes, users can achieve continuous transfer function accuracy at almost no computational cost. The innovation also enables computationally intensive block diagrams to run faster in real time, and satisfies Nyquist frequency requirements in models. Algebraic loops are resolved through fast sampling, making the innovation especially applicable to high-speed systems with saturation limits, dead-bands, and other constraints that create fast dynamics.

Posted in: Information Sciences, Electronics & Computers, Briefs


The Next Mars Journey

The next rover NASA will send to Mars in 2020 will carry seven instruments to conduct unprecedented science and exploration technology investigations on the Red Planet. The instruments were selected recently from 58 proposals from researchers and engineers worldwide. The Mars 2020 mission will be based on the design of the Mars Science Laboratory rover, Curiosity.

Posted in: UpFront


Product of the Month: September 2014

Dewetron, Wakefield, RI, has introduced the TrendCorder series of instruments designed for basic data acquisition applications in industry. They feature intuitive, multi-touch operation, enabling them to be operated 100% by touch, including alphanumeric entry, channel setup, and display configuration. When the instrument is turned on, an app loads and shows incoming data immediately. The DejaVIEW™ feature enables a user to scroll back on the recorder graph to any place in the recording, and pinch/zoom on the graph to see any detail, no matter how far back in time, without interrupting current recording. This is designed for operators conducting long-term testing that cannot be interrupted. The instruments feature a 15.4" wide aspect multi-touch display, and data is streamed continuously to disk at rates up to 200 MB/s. The TrendCorder has four slots for TRION series plug-in modules. Three 6-channel modules are included in the TRC-18, with one slot free; the TRC-6 has one 6-channel module, with three slots free. The system weighs 18.7 pounds, including the input modules.

Posted in: Products


Unique Camera Gauge System Controls Spring Manufacturing

Efficient and accurate operations are vital to the success of today’s manufacturer. Newcomb Spring, a manufacturer of custom springs, wire forms and stampings, is continually working to improve their production processes. The company has also seen an increasing number of requests for reports that detail the compliance of completed orders. Newcomb’s in-house Research and Development (R&D) Department is tasked with developing and building new technologies and equipment to solve unique challenges as well as improve overall operations and efficiency. Recently, Newcomb Spring introduced its own camera gauge system, developed by its R&D team, which was designed to provide high-speed manufacturing with automatic adjustments, extremely high levels of compliance, and reportable accuracy unmatched in the industry.

Posted in: Features, Photonics, Articles


Securing and Validating Critical Vision Data

Manufacturing companies are placing increasing emphasis on data security throughout their operations to protect confidential data and to validate that their systems are protected against unauthorized and unwanted changes. The critical role that vision plays in many manufacturing processes makes it essential that system security be improved for vision applications. A new generation of vision-specific security tools offers improvements in access control, change tracking, auditing, and general network security to help ensure the integrity of vision applications while at the same time protecting data confidentiality.

Posted in: Applications, Photonics, Application Briefs


Solar Pumped Fiber Laser for Solar Sail Propulsion and Remote Power Transfer

The photovoltaic capability of any instrument can be enhanced by delivering extra power via a space-based, broadband laser beam. Goddard Space Flight Center, Greenbelt, Maryland A new method has been developed to create coherent laser light efficiently with direct optical coupling of the Sun’s energy into the gain medium for multiple uses. New advances in solar cell photovoltaic (PV) technologies have greatly improved their efficiencies, mostly by improving their ability to convert many wavelengths or wider bands of the solar spectrum to electricity. New advances in actively doped fibers and optical glasses have been shown to produce very broad, multi-line absorption bands as well as stimulated emission lines, or laser lines. By designing the optical cavity system to feed back all emission bands into the gain media for amplification, a multi-wavelength source can be generated requiring no electronics.

Posted in: Tech Briefs, Physical Sciences, Photonics, Briefs


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