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Sample records for dsp based sliding

  1. DSP based data acquisition system

    NASA Astrophysics Data System (ADS)

    Prasad, Peeyush; Subrahmanya, C. R.

    A new DSP based data acquisition system based on commercial, off-the-shelf available hardware is presented. The board features friendly high speed input and output interfaces, a powerful DSP and hardware offloading of essing to an FPGA. For flexibility of development, a soft realtime linux based kernel popular among embedded developers (uClinux) has been ported on the board.The development environment is fully open source both for the target as well as for host software. The motivation behind creating the system, the development ess and the current status is described. Some results obtained with this system as used in typical applications are also presented.

  2. Speech feature extracting based on DSP

    NASA Astrophysics Data System (ADS)

    Niu, Jingtao; Shi, Zhongke

    2003-09-01

    In this paper, for the voiced frame in the speech processing, the implementations of LPC prognosticate coefficient resolution by Levisohn-Durbin algorithm on the DSP based system was proposed, and also the implementation of L. R. Rabiner basic frequency estimation is discussed. At the end of this paper, several new methods of sound feature extraction only by voiced frame is also discussed.

  3. Hyperspectral image data compression based on DSP

    NASA Astrophysics Data System (ADS)

    Fan, Jiming; Zhou, Jiankang; Chen, Xinhua; Shen, Weimin

    2010-11-01

    The huge data volume of hyperspectral image challenges its transportation and store. It is necessary to find an effective method to compress the hyperspectral image. Through analysis and comparison of current various algorithms, a mixed compression algorithm based on prediction, integer wavelet transform and embedded zero-tree wavelet (EZW) is proposed in this paper. We adopt a high-powered Digital Signal Processor (DSP) of TMS320DM642 to realize the proposed algorithm. Through modifying the mixed algorithm and optimizing its algorithmic language, the processing efficiency of the program was significantly improved, compared the non-optimized one. Our experiment show that the mixed algorithm based on DSP runs much faster than the algorithm on personal computer. The proposed method can achieve the nearly real-time compression with excellent image quality and compression performance.

  4. Low Power Systolic Array Based Digital Filter for DSP Applications

    PubMed Central

    Karthick, S.; Valarmathy, S.; Prabhu, E.

    2015-01-01

    Main concepts in DSP include filtering, averaging, modulating, and correlating the signals in digital form to estimate characteristic parameter of a signal into a desirable form. This paper presents a brief concept of low power datapath impact for Digital Signal Processing (DSP) based biomedical application. Systolic array based digital filter used in signal processing of electrocardiogram analysis is presented with datapath architectural innovations in low power consumption perspective. Implementation was done with ASIC design methodology using TSMC 65 nm technological library node. The proposed systolic array filter has reduced leakage power up to 8.5% than the existing filter architectures. PMID:25922854

  5. Low Power Systolic Array Based Digital Filter for DSP Applications.

    PubMed

    Karthick, S; Valarmathy, S; Prabhu, E

    2015-01-01

    Main concepts in DSP include filtering, averaging, modulating, and correlating the signals in digital form to estimate characteristic parameter of a signal into a desirable form. This paper presents a brief concept of low power datapath impact for Digital Signal Processing (DSP) based biomedical application. Systolic array based digital filter used in signal processing of electrocardiogram analysis is presented with datapath architectural innovations in low power consumption perspective. Implementation was done with ASIC design methodology using TSMC 65 nm technological library node. The proposed systolic array filter has reduced leakage power up to 8.5% than the existing filter architectures.

  6. A DSP-based infrared and optical bidimensional detectors controller

    NASA Astrophysics Data System (ADS)

    Iriarte, Arturo; Martínez, Luis A.; Ángeles, Fernando; Bernal, Abel; Lara, Gerardo

    2008-07-01

    The Institute of Astronomy at the Universidad Nacional Autonoma de México have developed and tested a CCD controller based on Texas Instruments Digital Signal Processor (DSP) TMS30C31@50MHz. Images are temporally stored in a 2MB static RAM attached to the DSP and transferred to the host computer running under Linux. Both tasks, acquisition and timing, are programmable so it can be conditioned to control any bidimensional detector. Analog voltage for bias, offsets and gains are fully programmable also. The system has been tested on an infrared Hawaii detector and fast Marconi 80x80 pixels CCD.

  7. Modular uncooled video engines based on a DSP processor

    NASA Astrophysics Data System (ADS)

    Schapiro, F.; Milstain, Y.; Aharon, A.; Neboshchik, A.; Ben-Simon, Y.; Kogan, I.; Lerman, I.; Mizrahi, U.; Maayani, S.; Amsterdam, A.; Vaserman, I.; Duman, O.; Gazit, R.

    2011-06-01

    The market demand for low SWaP (Size, Weight and Power) uncooled engines keeps growing. Low SWaP is especially critical in battery-operated applications such as goggles and Thermal Weapon Sights. A new approach for the design of the engines was implemented by SCD to optimize size and power consumption at system level. The new approach described in the paper, consists of: 1. A modular hardware design that allows the user to define the exact level of integration needed for his system 2. An "open architecture" based on the OMAPTM530 DSP that allows the integrator to take advantage of unused hardware (FPGA) and software (DSP) resources, for implementation of additional algorithms or functionality. The approach was successfully implemented on the first generation of 25μm pitch BIRD detectors, and more recently on the new, 640 x480, 17 μm pitch detector.

  8. [Portable lung function parameters testing system based on DSP].

    PubMed

    Guo, Zhanshe; Yuan, Minzhong; Zhou, Hui

    2012-11-01

    Lung function monitoring is a critical technique for clinical medicine. Currently, the lung function testing devices used in our domestic hospitals are both expensive and bulky. A portable and accurate lung function parameters testing system is highly desired and is proposed in this paper. The hardware of the system is based on DSP technology. The breathing passage is designed with an aim suitable for the breathe and signal detection. We use the direct detection method to detect the gas flow, the breathing passage pressure and the breathing time. Thanks to the powerful data processing ability and the high operation speed of the DSP, breathing signals can be easily analyzed. Thus, several lung function parameters of clinical significance can be obtained. Experiments show that the accuracy of the system is better than 3%, and could meet the demand of the lung function testing.

  9. [Research on automatic external defibrillator based on DSP].

    PubMed

    Jing, Jun; Ding, Jingyan; Zhang, Wei; Hong, Wenxue

    2012-10-01

    Electrical defibrillation is the most effective way to treat the ventricular tachycardia (VT) and ventricular fibrillation (VF). An automatic external defibrillator based on DSP is introduced in this paper. The whole design consists of the signal collection module, the microprocessor controlingl module, the display module, the defibrillation module and the automatic recognition algorithm for VF and non VF, etc. This automatic external defibrillator has achieved goals such as ECG signal real-time acquisition, ECG wave synchronous display, data delivering to U disk and automatic defibrillate when shockable rhythm appears, etc.

  10. Architectures for parallel DSP-based adaptive optics feedback control

    NASA Astrophysics Data System (ADS)

    McCarthy, Daniel F.

    1999-11-01

    We have developed a digital image processing system for real-time digital image processing feedback control of adaptive optics systems and simulation of optical image processing algorithms. The system uses multi-computer architecture to capture data from an imaging device such as a charge coupled device camera, process the image data, and control a spatial light-modulator, typically a liquid crystal modulator or a micro-electro mechanical system. The system is a Windows NT Pentium-based system combined with a commercial off-the-shelf peripheral component interconnect bus multi-processor system. The multi-processor is based on the Analog Devices super Harvard architecture computer (SHARC) processor, and field programmable gate arrays (FPGAs). The SHARCs provide a scalable reconfigurable C language-based digital signal processing (DSP) development environment. The FPGAs are typically used as reprogrammable interface controllers designed to integrate several off-the- shelf and custom imagers and light modulators into the system. The FPGAs can also be used in concert with the SHARCs for implementation of application-specific high-speed DSP algorithms.

  11. A method of image multi-resolution processing based on FPGA + DSP architecture

    NASA Astrophysics Data System (ADS)

    Peng, Xiaohan; Zhong, Sheng; Lu, Hongqiang

    2015-10-01

    In real-time image processing, with the improvement of resolution and frame rate of camera imaging, not only the requirement of processing capacity is improving, but also the requirement of the optimization of process is improving. With regards to the FPGA + DSP architecture image processing system, there are three common methods to overcome the challenge above. The first is using higher performance DSP. For example, DSP with higher core frequency or with more cores can be used. The second is optimizing the processing method, make the algorithm to accomplish the same processing results but spend less time. Last but not least, pre-processing in the FPGA can make the image processing more efficient. A method of multi-resolution pre-processing by FPGA based on FPGA + DSP architecture is proposed here. It takes advantage of built-in first in first out (FIFO) and external synchronous dynamic random access memory (SDRAM) to buffer the images which come from image detector, and provides down-sampled images or cut-down images for DSP flexibly and efficiently according to the request parameters sent by DSP. DSP can thus get the degraded image instead of the whole image to process, shortening the processing time and transmission time greatly. The method results in alleviating the burden of image processing of DSP and also solving the problem of single method of image resolution reduction cannot meet the requirements of image processing task of DSP.

  12. Development of DSP and FPGA based 4-axis motion controller

    NASA Astrophysics Data System (ADS)

    He, Shuai; Gao, Xiaorong; Peng, Chaoyong; Zhang, Yu

    2010-08-01

    This paper presents a DSP and FPGA based 4-axis motion controller, which use host PC as the platform. By adopting the strategy of two stage interpolation, the proposed motion controller supports 2-axis circular interpolation and 3-axis linear interpolation, and its maximum output pulse frequency of each axis can be up to 8 MHz. The controlling algorithms, such as improved coarse interpolation based on the time division principle, T-curve and S-curve velocity profile generation and the error compensation for the position loop, are implemented by DSP to ensure the high performance of the proposed motion controller. Meanwhile, the FPGA integrates PCI bus controller, dual port RAM, second-stage interpolation, encoder feedback logic circuit etc., which allows a flexible, compact, low-cost solution for various applications. Experimental results demonstrate that the presented motion controller features the merits such as the good real-time performance and high machining precision, and it can be used for a wide range of applications in numerical control system.

  13. An endless polarization stabilizer based on DSP system

    NASA Astrophysics Data System (ADS)

    Zhao, Xinyuan; Weng, Xuan; Tian, Feng; Zhang, Xiaoguang

    2009-11-01

    An endless polarization stabilizer based on DSP system is reported. It can transform the state of polarization (SOP) of optical signal to any desired SOP and maintaining output signal at the desired SOP. Feedback controlling method is applied to the proposed polarization stabilizer. We design a target function relates to current SOP and the desired SOP in transmission link. It has only one extremum when SOP in transmission link is exactly the same with the desired SOP. Particle swarm optimization algorithm is employed to search the extremum point. To investigate performance of the proposed polarization stabilizer, HP11896A polarization controller is used as polarization scrambler. We test performance of the polarization stabilizer under rate 1 (~16 rad/s), 4 (~33 rad/s), and 8 ( ~65 rad/s), separately. Under the existing condition of our laboratory, the developed polarization stabilizer has the ability of stabilization up to 65 rad/s SOP changes (rate 8).

  14. A DSP based power electronics interface for alternative /renewable energy system.

    SciTech Connect

    1999-09-28

    This report is an update on the research project involving the implementation of a DSP-based power electronics interface for alternate/renewable energy systems, that was funded by the Department of Energy under the Inventions and Innovations program.

  15. Design of dual DC motor control system based on DSP

    NASA Astrophysics Data System (ADS)

    Shi, Peicheng; Wang, Suo; Xu, Zengwei; Xiao, Ping

    2017-08-01

    Multi-motor control systems are widely used in actual production and life, such as lifting stages, robots, printing systems. This paper through serial communication between PC and DSP, dual DC motor control system consisting of PC as the host computer, DSP as the lower computer with synchronous PWM speed regulation, commutation and selection functions is designed. It sends digital control instructions with host computer serial debugger to lower computer, to instruct the motor to complete corresponding actions. The hardware and software design of the control system are given, and feasibility and validity of the control system are verified by experiments. The expected design goal is achieved.

  16. A DSP based data acquisition module for colliding beam accelerators

    SciTech Connect

    Mead, J.A.; Shea, T.J.

    1995-10-01

    In 1999, the Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory will accelerate and store two beams of gold ions. The ions will then collide head on at a total energy of nearly 40 trillion electron volts. Attaining these conditions necessitates real-time monitoring of beam parameters and for this purpose a flexible data acquisition platform has been developed. By incorporating a floating point digital signal processor (DSP) and standard input/output modules, this system can acquire and process data from a variety of beam diagnostic devices. The DSP performs real time corrections, filtering, and data buffering to greatly reduce control system computation and bandwidth requirements. We will describe the existing hardware and software while emphasizing the compromises required to achieve a flexible yet cost effective system. Applications in several instrumentation systems currently construction will also be presented.

  17. Implementation of DSP Based Cost Effective Inverter Fed Induction Motor Drive with VisSim

    NASA Astrophysics Data System (ADS)

    Mohanty, Nalin K.; Muthu, Ranganath

    2012-03-01

    The implementation of a Digital Signal Processor (DSP) based high-performance cost effective fed Induction Motor drive with VisSim/Embedded Controls Developer (ECD) is presented in this paper. In the experimental work VisSim/ECD software automatically converts the in built block diagram to C code and compiles, links, and downloads the code to DSP processor TMS320F2812. The DSP processor generates the required PWM to a cost effective ie four switch 3-phase (FSTPI) inverter. The power circuit of FSTPI fed drive system consists of an IGBT based FSTPI bridge inverter module feeding to a 5 hp three-phase squirrel cage induction motor. In this work the speed of induction motor output is shown by the GUI of VisSim/ECD and SPWM pulses, line voltages and line current output curves are shown using digital storage oscilloscope to demonstrate the feasibility of the system.

  18. A Real-Time System for Lane Detection Based on FPGA and DSP

    NASA Astrophysics Data System (ADS)

    Xiao, Jing; Li, Shutao; Sun, Bin

    2016-12-01

    This paper presents a real-time lane detection system including edge detection and improved Hough Transform based lane detection algorithm and its hardware implementation with field programmable gate array (FPGA) and digital signal processor (DSP). Firstly, gradient amplitude and direction information are combined to extract lane edge information. Then, the information is used to determine the region of interest. Finally, the lanes are extracted by using improved Hough Transform. The image processing module of the system consists of FPGA and DSP. Particularly, the algorithms implemented in FPGA are working in pipeline and processing in parallel so that the system can run in real-time. In addition, DSP realizes lane line extraction and display function with an improved Hough Transform. The experimental results show that the proposed system is able to detect lanes under different road situations efficiently and effectively.

  19. Research of Data Acquisition and Analysis System for Internal Combustion Engine Based on DSP

    NASA Astrophysics Data System (ADS)

    Gao, Y. H.; Tian, X. L.; Cheng, P.; Chang, X.; Dou, W. J.

    2006-10-01

    In the paper, the structure, working principle, functions and characteristics of an data acquisition and analysis system for internal combustion engines (I.C. engine) based on DSP is introduced. The DSP can not only acquire and analyze the data alone, also can work with the PC together to form data acquisition and analysis system with high speed and large memory. The system takes advantages of TMS320F2812's plenty of peripherals on chip, becomes small and easy for installation. USB technique is used to translate data between DSP and PC in high speed, so the system's real time processing is proved very much. It is proved that the designed system can acquire and analyze the steady and transient parameters of the I.C. engine very well.

  20. [Design of high performance DSP-based gradient calculation module for MRI].

    PubMed

    Pan, Wenyu; Zhang, Fu; Luo, Hai; Zhou, Heqin

    2011-05-01

    A gradient calculation module based on high performance DSP was designed to meet the needs of digital MRI spectrometer. According to the requirements of users, this apparatus can achieve rotation transformation, pre-emphasis, shimming and other gradient calculation functions in a single chip of DSP. It then outputs gradient waveform data of channel X, Y, Z and shimming data of channel B0. Experiments show that the design has good versatility and can satisfy the functional, speed and accuracy requirements of MRI gradient calculation. It provides a practical gradient calculation solution for the development of digital spectrometer.

  1. Customized DSP-based vibration measurement for wind turbines

    SciTech Connect

    LaWhite, N.E.; Cohn, K.E.

    1996-12-31

    As part of its Advanced Distributed Monitoring System (ADMS) project funded by NREL, Second Wind Inc. is developing a new vibration measurement system for use with wind turbines. The system uses low-cost accelerometers originally designed for automobile airbag crash-detection coupled with new software executed on a Digital Signal Processor (DSP) device. The system is envisioned as a means to monitor the mechanical {open_quotes}health{close_quotes} of the wind turbine over its lifetime. In addition the system holds promise as a customized emergency vibration detector. The two goals are very different and it is expected that different software programs will be executed for each function. While a fast Fourier transform (FFT) signature under given operating conditions can yield much information regarding turbine condition, the sampling period and processing requirements make it inappropriate for emergency condition monitoring. This paper briefly reviews the development of prototype DSP and accelerometer hardware. More importantly, it reviews our work to design prototype vibration alarm filters. Two-axis accelerometer test data from the experimental FloWind vertical axis wind turbine is analyzed and used as a development guide. Two levels of signal processing are considered. The first uses narrow band pre-processing filters at key fundamental frequencies such as the 1P, 2P and 3P. The total vibration energy in each frequency band is calculated and evaluated as a possible alarm trigger. In the second level of signal processing, the total vibration energy in each frequency band is further decomposed using the two-axis directional information. Directional statistics are calculated to differentiate between linear translations and circular translations. After analyzing the acceleration statistics for normal and unusual operating conditions, the acceleration processing system described could be used in automatic early detection of fault conditions. 9 figs.

  2. Frequency-dependent performance analysis of a parallel DSP-based computer system

    NASA Astrophysics Data System (ADS)

    Christou, Ch. S.

    2014-11-01

    The performance of a shared-memory low-cost high-performance DSP-Based multiprocessor system [3] is investigated, by varying the frequency of the core processor from 200MHz to 1GHZ, in steps of 200 MHZ, and keeping constant parameters such as the shared-memory-access-time and the prefetching-workload-size. The innovation of this Parallel DSP-Based computer system is the introduction of two small programmable small fast memories (Twins) between the processor and the shared bus interconnect. While one memory (Twin) transfers data from/to the shared memory, the other Twin supplies the core DSP-processor with data. Results indicate an increase of the shared-bus bottleneck as the core DSP processors' clock-rate increases. Workload of the Twins is processed faster thus greater the demand of the shared-bus. Results show an effectively supported robust parallel shared-memory system where fewer but faster (clocked with higher frequency) processors produce the same execution times as a greater number of slower processors, with most system configurations achieving perfect speedups, mainly due to the twin-prefetching mechanism.

  3. Terminal sliding mode fuzzy control based on multiple sliding surfaces for nonlinear ship autopilot systems

    NASA Astrophysics Data System (ADS)

    Yuan, Lei; Wu, Han-Song

    2010-12-01

    A terminal sliding mode fuzzy control based on multiple sliding surfaces was proposed for ship course tracking steering, which takes account of rudder characteristics and parameter uncertainty. In order to solve the problem, the controller was designed by employing the universal approximation property of fuzzy logic system, the advantage of Nussbaum function, and using multiple sliding mode control algorithm based on the recursive technique. In the last step of designing, a nonsingular terminal sliding mode was utilized to drive the last state of the system to converge in a finite period of time, and high-order sliding mode control law was designed to eliminate the chattering and make the system robust. The simulation results showed that the controller designed here could track a desired course fast and accurately. It also exhibited strong robustness peculiarly to system, and had better adaptive ability than traditional PID control algorithms.

  4. The real-time complex cruise scene motion detection system based on DSP

    NASA Astrophysics Data System (ADS)

    Wu, Zhi-guo; Wang, Ming-jia

    2014-11-01

    Dynamic target recognition is an important issue in the field of image processing research. It is widely used in photoelectric detection, target tracking, video surveillance areas. Complex cruise scene of target detection, compared to the static background, since the target and background objects together and both are in motion, greatly increases the complexity of moving target detection and recognition. Based on the practical engineering applications, combining an embedded systems and real-time image detection technology, this paper proposes a real-time movement detection method on an embedded system based on the FPGA + DSP system architecture on an embedded system. The DSP digital image processing system takes high speed digital signal processor DSP TMS320C6416T as the main computing components. And we take large capacity FPGA as coprocessor. It is designed and developed a high-performance image processing card. The FPGA is responsible for the data receiving and dispatching, DSP is responsible for data processing. The FPGA collects image data and controls SDRAM according to the digital image sequence. The SDRAM realizes multiport image buffer. DSP reads real-time image through SDRAM and performs scene motion detection algorithm. Then we implement the data reception and data processing parallelization. This system designs and realizes complex cruise scene motion detection for engineering application. The image edge information has the anti-light change and the strong anti-interference ability. First of all, the adjacent frame and current frame image are processed by convolution operation, extract the edge images. Then we compute correlation strength and the value of movement offset. We can complete scene motion parameters estimation by the result, in order to achieve real-time accurate motion detection. We use images in resolution of 768 * 576 and 25Hz frame rate to do the real-time cruise experiment. The results show that the proposed system achieves real

  5. Design of a system based on DSP and FPGA for video recording and replaying

    NASA Astrophysics Data System (ADS)

    Kang, Yan; Wang, Heng

    2013-08-01

    This paper brings forward a video recording and replaying system with the architecture of Digital Signal Processor (DSP) and Field Programmable Gate Array (FPGA). The system achieved encoding, recording, decoding and replaying of Video Graphics Array (VGA) signals which are displayed on a monitor during airplanes and ships' navigating. In the architecture, the DSP is a main processor which is used for a large amount of complicated calculation during digital signal processing. The FPGA is a coprocessor for preprocessing video signals and implementing logic control in the system. In the hardware design of the system, Peripheral Device Transfer (PDT) function of the External Memory Interface (EMIF) is utilized to implement seamless interface among the DSP, the synchronous dynamic RAM (SDRAM) and the First-In-First-Out (FIFO) in the system. This transfer mode can avoid the bottle-neck of the data transfer and simplify the circuit between the DSP and its peripheral chips. The DSP's EMIF and two level matching chips are used to implement Advanced Technology Attachment (ATA) protocol on physical layer of the interface of an Integrated Drive Electronics (IDE) Hard Disk (HD), which has a high speed in data access and does not rely on a computer. Main functions of the logic on the FPGA are described and the screenshots of the behavioral simulation are provided in this paper. In the design of program on the DSP, Enhanced Direct Memory Access (EDMA) channels are used to transfer data between the FIFO and the SDRAM to exert the CPU's high performance on computing without intervention by the CPU and save its time spending. JPEG2000 is implemented to obtain high fidelity in video recording and replaying. Ways and means of acquiring high performance for code are briefly present. The ability of data processing of the system is desirable. And smoothness of the replayed video is acceptable. By right of its design flexibility and reliable operation, the system based on DSP and FPGA

  6. A portable detection instrument based on DSP for beef marbling

    NASA Astrophysics Data System (ADS)

    Zhou, Tong; Peng, Yankun

    2014-05-01

    Beef marbling is one of the most important indices to assess beef quality. Beef marbling is graded by the measurement of the fat distribution density in the rib-eye region. However quality grades of beef in most of the beef slaughtering houses and businesses depend on trainees using their visual senses or comparing the beef slice to the Chinese standard sample cards. Manual grading demands not only great labor but it also lacks objectivity and accuracy. Aiming at the necessity of beef slaughtering houses and businesses, a beef marbling detection instrument was designed. The instrument employs Charge-coupled Device (CCD) imaging techniques, digital image processing, Digital Signal Processor (DSP) control and processing techniques and Liquid Crystal Display (LCD) screen display techniques. The TMS320DM642 digital signal processor of Texas Instruments (TI) is the core that combines high-speed data processing capabilities and real-time processing features. All processes such as image acquisition, data transmission, image processing algorithms and display were implemented on this instrument for a quick, efficient, and non-invasive detection of beef marbling. Structure of the system, working principle, hardware and software are introduced in detail. The device is compact and easy to transport. The instrument can determine the grade of beef marbling reliably and correctly.

  7. An Advanced Compiler Designed for a VLIW DSP for Sensors-Based Systems

    PubMed Central

    Yang, Xu; He, Hu

    2012-01-01

    The VLIW architecture can be exploited to greatly enhance instruction level parallelism, thus it can provide computation power and energy efficiency advantages, which satisfies the requirements of future sensor-based systems. However, as VLIW codes are mainly compiled statically, the performance of a VLIW processor is dominated by the behavior of its compiler. In this paper, we present an advanced compiler designed for a VLIW DSP named Magnolia, which will be used in sensor-based systems. This compiler is based on the Open64 compiler. We have implemented several advanced optimization techniques in the compiler, and fulfilled the O3 level optimization. Benchmarks from the DSPstone test suite are used to verify the compiler. Results show that the code generated by our compiler can make the performance of Magnolia match that of the current state-of-the-art DSP processors. PMID:22666040

  8. An advanced compiler designed for a VLIW DSP for sensors-based systems.

    PubMed

    Yang, Xu; He, Hu

    2012-01-01

    The VLIW architecture can be exploited to greatly enhance instruction level parallelism, thus it can provide computation power and energy efficiency advantages, which satisfies the requirements of future sensor-based systems. However, as VLIW codes are mainly compiled statically, the performance of a VLIW processor is dominated by the behavior of its compiler. In this paper, we present an advanced compiler designed for a VLIW DSP named Magnolia, which will be used in sensor-based systems. This compiler is based on the Open64 compiler. We have implemented several advanced optimization techniques in the compiler, and fulfilled the O3 level optimization. Benchmarks from the DSPstone test suite are used to verify the compiler. Results show that the code generated by our compiler can make the performance of Magnolia match that of the current state-of-the-art DSP processors.

  9. Homology-based modeling of the Erwinia amylovora type III secretion chaperone DspF used to identify amino acids required for virulence and interaction with the effector DspE.

    PubMed

    Triplett, Lindsay R; Wedemeyer, William J; Sundin, George W

    2010-09-01

    The structure of DspF, a type III secretion system (T3SS) chaperone required for virulence of the fruit tree pathogen Erwinia amylovora, was modeled based on predicted structural homology to characterized T3SS chaperones. This model guided the selection of 11 amino acid residues that were individually mutated to alanine via site-directed mutagenesis. Each mutant was assessed for its effect on virulence complementation, dimerization and interaction with the N-terminal chaperone-binding site of DspE. Four amino acid residues were identified that did not complement the virulence defect of a dspF knockout mutant, and three of these residues were required for interaction with the N-terminus of DspE. This study supports the significance of the predicted beta-sheet helix-binding groove in DspF chaperone function.

  10. A DSP based power electronics interface for alternate/renewable energy systems. Quarterly report 3.

    SciTech Connect

    2000-03-31

    This report is an update on the research project involving the implementation of a DSP based power electronics interface for alternate/renewable energy systems that was funded by the Department of Energy under the Inventions and Innovations program 1998. The objective of this research is to develop a utility interface (dc to ac converter) suitable to interconnect alternate/renewable energy sources to the utility system. The DSP based power electronics interface in comparison with existing methods will excel in terms of efficiency, reliability and cost. Moreover DSP-based control provides the flexibility to upgrade/modify control algorithms to meet specific system requirements. The proposed interface will be capable of maintaining stiffness of the ac voltages at the point of common coupling regardless of variation in the input dc bus voltage. This will be achieved without the addition of any extra components to the basic interface topology but by inherently controlling the inverter switching strategy in accordance to the input voltage variation.

  11. Positioning approach based on Mach-Zehnder fiber sensors and a DSP processor

    NASA Astrophysics Data System (ADS)

    Wan, Xiong; Du, Tingting; Zhang, Zhimin; Zhang, Huaming; Wang, Peng

    2013-12-01

    A positioning system based on Mach-Zehnder optical fiber interferometer is proposed, which can sense vibration information along the circumference of the fiber sensor and hence be applied to positioning invasions as a safe-guard system in residence communities. A cross-correlation algorithm fulfilled with a DSP processor has been adopted to calculate the time difference of two channels of the Mach-Zehnder optical fiber interferometer. A signal identification algorithm is proposed to decrease the workload of the DSP when no vibration occurs. An experiment with 11.28 kilometers sensing fiber has been carried out, whose results show the Mach-Zehnder positioning system identifies the position of vibration instantaneously and has a 44 meters positioning error within the total sensing distance.

  12. Design of overload vehicle monitoring and response system based on DSP

    NASA Astrophysics Data System (ADS)

    Yu, Yan; Liu, Yiheng; Zhao, Xuefeng

    2014-03-01

    The overload vehicles are making much more damage to the road surface than the regular ones. Many roads and bridges are equipped with structural health monitoring system (SHM) to provide early-warning to these damage and evaluate the safety of road and bridge. However, because of the complex nature of SHM system, it's expensive to manufacture, difficult to install and not well-suited for the regular bridges and roads. Based on this application background, this paper designs a compact structural health monitoring system based on DSP, which is highly integrated, low-power, easy to install and inexpensive to manufacture. The designed system is made up of sensor arrays, the charge amplifier module, the DSP processing unit, the alarm system for overload, and the estimate for damage of the road and bridge structure. The signals coming from sensor arrays go through the charge amplifier. DSP processing unit will receive the amplified signals, estimate whether it is an overload signal or not, and convert analog variables into digital ones so that they are compatible with the back-end digital circuit for further processing. The system will also restrict certain vehicles that are overweight, by taking image of the car brand, sending the alarm, and transferring the collected pressure data to remote data center for further monitoring analysis by rain-flow counting method.

  13. Efficient RTL-based code generation for specified DSP C-compiler

    NASA Astrophysics Data System (ADS)

    Pan, Qiaohai; Liu, Peng; Shi, Ce; Yao, Qingdong; Zhu, Shaobo; Yan, Li; Zhou, Ying; Huang, Weibing

    2001-12-01

    A C-compiler is a basic tool for most embedded systems programmers. It is the tool by which the ideas and algorithms in your application (expressed as C source code) are transformed into machine code executable by the target processor. Our research was to develop an optimizing C-compiler for a specified 16-bit DSP. As one of the most important part in the C-compiler, Code Generation's efficiency and performance directly affect to the resultant target assembly code. Thus, in order to improve the performance of the C-compiler, we constructed an efficient code generation based on RTL, an intermediate language used in GNU CC. The code generation accepts RTL as main input, takes good advantage of features specific to RTL and specified DSP's architecture, and generates compact assembly code of the specified DSP. In this paper, firstly, the features of RTL will be briefly introduced. Then, the basic principle of constructing the code generation will be presented in detail. According to the basic principle, this paper will discuss the architecture of the code generation, including: syntax tree construction / reconstruction, basic RTL instruction extraction, behavior description at RTL level, and instruction description at assembly level. The optimization strategies used in the code generation for generating compact assembly code will also be given in this paper. Finally, we will achieve the conclusion that the C-compiler using this special code generation achieved high efficiency we expected.

  14. Design and Development of Laser Doppler Velocimetry Based on DSP Technique for Blood Flow Measurement

    DTIC Science & Technology

    2000-07-01

    the water to serve as scattering particles (mass concentration = 0.1 %), and a DC motor with a precise controller was also employed to pump the solution...advanced analysis could be taken. 203 Liquid Fg Laser diode ~~Photo-detector0= Pressure contr oler •Moto~r DC motor controlle, role•[_ 0-300ORPM Fig... DC motor 6. CONCLUSIONS We have developed a portable, real-time, and turn-key LDV system based on DSP techniques. Two most frequently used algoritluns

  15. [Study for phagaquosonogram acquisition module based on DSP].

    PubMed

    Lu, Qiang; Guo, Yong-Xin; Zhang, Guang-Yu; Cui, Dong; Wang, Shi-Gang; Jiao, Qing

    2009-07-01

    In this paper, a phagaquosonogram acquisition, a module with TMS320C6713 as a core, and USB as communicating pattern is introduced based on VC++6.0. The structure of the module, hardware configuration, software design and the experiment of the real phagaquosonogram signal collection are presented. It is shown that the module can extract human phagaquosonogram signal reliably and availably.

  16. [Development of a portable dynamic state ECG based on DSP].

    PubMed

    Song, Li; Meng, Qing-jian; Zhang, Guang-yu; Cao, Wei-fang

    2009-11-01

    The Portable dynamic state electrocardiogram collecting system is introduced by using TMS302VC5402, TLC320AD50C, liquid crystal display model, and so on. This dissertation describes the work principle of the system and uses the united algorithm based on wavelet to identify and locate the ECG characteristic waves. This system has as follows of advantages: big memory, low noise,high common mode rejection ratio, the low power consume,the long record time etc.

  17. The Development of a Portable ECG Monitor Based on DSP

    NASA Astrophysics Data System (ADS)

    Nan, CHI Jian; Tao, YAN Yan; Meng Chen, LIU; Li, YANG

    With the advent of global information, researches of Smart Home system are in the ascendant, the ECG real-time detection, and wireless transmission of ECG become more useful. In order to achieve the purpose we developed a portable ECG monitor which achieves the purpose of cardiac disease remote monitoring, and will be used in the physical and psychological disease surveillance in smart home system, we developed this portable ECG Monitor, based on the analysis of existing ECG Monitor, using TMS320F2812 as the core controller, which complete the signal collection, storage, processing, waveform display and transmission.

  18. A DSP-based controller for a linear actuator system with sub-angstrom resolution and 15-millimeter travel range

    SciTech Connect

    Smolyanitskiy, A.; Shu, D.; Wong, T.; Experimental Facilities Division; IIT

    2005-01-01

    We have designed and tested a new digital signal processor (DSP)-based closed-loop feedback controller for a linear actuator system with sub-angstrom resolution and 15-mm travel range. The linear actuator system consists of a laser Doppler encoder with multiple-reflection optics [1], a high-stiffness weak-link mechanism with high driving sensitivity and stability [2], and a Texas Instruments TMS320C40 DSP-based controller for high-performance closed-loop feedback control. In this paper, we discuss the DSP-based controller design, as well as recent test results yielding step sizes below 50 picometers obtained with the atomic force microprobe setup.

  19. Comparison of DSP-based nonlinear equalizers for intra-channel nonlinearity compensation in coherent optical OFDM.

    PubMed

    Giacoumidis, Elias; Mhatli, Sofien; Nguyen, Tu; Le, Son T; Aldaya, Ivan; McCarthy, Mary E; Ellis, Andrew D; Eggleton, Benjamin J

    2016-06-01

    A novel versatile digital signal processing (DSP)-based equalizer using support vector machine regression (SVR) is proposed for 16-quadrature amplitude modulated (16-QAM) coherent optical orthogonal frequency-division multiplexing (CO-OFDM) and experimentally compared to traditional DSP-based deterministic fiber-induced nonlinearity equalizers (NLEs), namely the full-field digital back-propagation (DBP) and the inverse Volterra series transfer function-based NLE (V-NLE). For a 40 Gb/s 16-QAM CO-OFDM at 2000 km, SVR-NLE extends the optimum launched optical power (LOP) by 4 dB compared to V-NLE by means of reduction of fiber nonlinearity. In comparison to full-field DBP at a LOP of 6 dBm, SVR-NLE outperforms by ∼1  dB in Q-factor. In addition, SVR-NLE is the most computational efficient DSP-NLE.

  20. DSP-based hardware for real-time video coding

    NASA Astrophysics Data System (ADS)

    de Sa, Luis A. S. V.; Silva, Vitor M.; de la Cruz, Luis J.; Faria, Sergio; Amado, Pedro J.; Navarro, Antonio; Lopes, Fernando; Silvestre, Joao C.

    1992-04-01

    An important application of digital image processing is the compression of video sequences by one or two orders of magnitude with minor picture quality degradation. In order to achieve this data compression elaborated algorithms are used. They eliminate both spatial and temporal redundancy by using transform, differential, and variable length coding techniques. Two of these algorithms are the CCITT H.261 algorithm for videotelephony and the ISO MPEG algorithm for CD-ROM motion video. The hardware implementation of these algorithms is a formidable task in view of the number of operations (more than 1GFLOPS) that may be necessary. This paper discusses the compression and decompression of real-time video using a multiprocessor system based on digital signal processors. The system is based on the partition of each picture in horizontal strips which are operated by a local processor unit made by the combination of the TMS320C30 signal processor and an A121 discrete cosine transform processor. In the encoder, each strip processor inputs raw data from a video acquisition module through a common parallel video bus and outputs compressed data to a supervisor module through a common serial supervisor bus. In the decoder, the data flows through an inverse path, i.e., the processors receive data from a supervisor module and transmit data to a display module. All operations within the horizontal strips are independent from each other except when motion estimation is used. In this case, the processing elements have to access regions of the picture that are allocated to neighboring processors. The number of processors is related to the frame rate and the resolution of the image.

  1. QUALITY ASSESSMENT OF CONFOCAL MICROSCOPY SLIDE-BASED SYSTEMS: INSTABLITY

    EPA Science Inventory

    Background: All slide-based fluorescence cytometry detections systems basically include an excitation light source, intermediate optics, and a detection device (CCD or PMT). Occasionally, this equipment becomes unstable, generating unreliable and inferior data. Methods: A num...

  2. QUALITY ASSESSMENT OF CONFOCAL MICROSCOPY SLIDE-BASED SYSTEMS: INSTABLITY

    EPA Science Inventory

    Background: All slide-based fluorescence cytometry detections systems basically include an excitation light source, intermediate optics, and a detection device (CCD or PMT). Occasionally, this equipment becomes unstable, generating unreliable and inferior data. Methods: A num...

  3. An opto-electronic joint detection system based on DSP aiming at early cervical cancer screening

    NASA Astrophysics Data System (ADS)

    Wang, Weiya; Jia, Mengyu; Gao, Feng; Yang, Lihong; Qu, Pengpeng; Zou, Changping; Liu, Pengxi; Zhao, Huijuan

    2015-02-01

    The cervical cancer screening at a pre-cancer stage is beneficial to reduce the mortality of women. An opto-electronic joint detection system based on DSP aiming at early cervical cancer screening is introduced in this paper. In this system, three electrodes alternately discharge to the cervical tissue and three light emitting diodes in different wavelengths alternately irradiate the cervical tissue. Then the relative optical reflectance and electrical voltage attenuation curve are obtained by optical and electrical detection, respectively. The system is based on DSP to attain the portable and cheap instrument. By adopting the relative reflectance and the voltage attenuation constant, the classification algorithm based on Support Vector Machine (SVM) discriminates abnormal cervical tissue from normal. We use particle swarm optimization to optimize the two key parameters of SVM, i.e. nuclear factor and cost factor. The clinical data were collected on 313 patients to build a clinical database of tissue responses under optical and electrical stimulations with the histopathologic examination as the gold standard. The classification result shows that the opto-electronic joint detection has higher total coincidence rate than separate optical detection or separate electrical detection. The sensitivity, specificity, and total coincidence rate increase with the increasing of sample numbers in the training set. The average total coincidence rate of the system can reach 85.1% compared with the histopathologic examination.

  4. Sliding mode control for chaotic systems based on LMI

    NASA Astrophysics Data System (ADS)

    Wang, Hua; Han, Zheng-zhi; Xie, Qi-yue; Zhang, Wei

    2009-04-01

    This paper investigates the chaos control problem for a general class of chaotic systems. A feedback controller is established to guarantee asymptotical stability of the chaotic systems based on the sliding mode control theory. A new reaching law is introduced to solve the chattering problem that is produced by traditional sliding mode control. A dynamic compensator is designed to improve the performance of the closed-loop system in sliding mode, and its parameter is obtained from a linear matrix inequality (LMI). Simulation results for the well known Chua's circuit and Lorenz chaotic system are provided to illustrate the effectiveness of the proposed scheme.

  5. Characteristic Analysis and DSP Realization of Fractional-Order Simplified Lorenz System Based on Adomian Decomposition Method

    NASA Astrophysics Data System (ADS)

    Wang, Huihai; Sun, Kehui; He, Shaobo

    2015-06-01

    By adopting Adomian decomposition method, the fractional-order simplified Lorenz system is solved and implemented on a digital signal processor (DSP). The Lyapunov exponent (LE) spectra of the system is calculated based on QR-factorization, and it accords well with the corresponding bifurcation diagrams. We analyze the influence of the parameter and the fractional derivative order on the system characteristics by color maximum LE (LEmax) and chaos diagrams. It is found that the smaller the order is, the larger the LEmax is. The iteration step size also affects the lowest order at which the chaos exists. Further, we implement the fractional-order simplified Lorenz system on a DSP platform. The phase portraits generated on DSP are consistent with the results that were obtained by computer simulations. It lays a good foundation for applications of the fractional-order chaotic systems.

  6. Design of DSP-based high-power digital solar array simulator

    NASA Astrophysics Data System (ADS)

    Zhang, Yang; Liu, Zhilong; Tong, Weichao; Feng, Jian; Ji, Yibo

    2013-12-01

    To satisfy rigid performance specifications, a feedback control was presented for zoom optical lens plants. With the increasing of global energy consumption, research of the photovoltaic(PV) systems get more and more attention. Research of the digital high-power solar array simulator provides technical support for high-power grid-connected PV systems research.This paper introduces a design scheme of the high-power digital solar array simulator based on TMS320F28335. A DC-DC full-bridge topology was used in the system's main circuit. The switching frequency of IGBT is 25kHz.Maximum output voltage is 900V. Maximum output current is 20A. Simulator can be pre-stored solar panel IV curves.The curve is composed of 128 discrete points .When the system was running, the main circuit voltage and current values was feedback to the DSP by the voltage and current sensors in real-time. Through incremental PI,DSP control the simulator in the closed-loop control system. Experimental data show that Simulator output voltage and current follow a preset solar panels IV curve. In connection with the formation of high-power inverter, the system becomes gridconnected PV system. The inverter can find the simulator's maximum power point and the output power can be stabilized at the maximum power point (MPP).

  7. DSP with FPGAs: a Xilinx/Simulink-based course and laboratory

    NASA Astrophysics Data System (ADS)

    Meyer-Bäse, Uwe; Vera, A.; Meyer-Bäse, A.; Pattichis, M.; Perry, R.

    2008-04-01

    This is the third paper in a series that introduces a MatLab/Simulink-based design flow for FPGAs at an undergraduate curriculum level. In the first paper presented at SPIE 2006 we analyzed the design tools, while in the second paper presented at SPIE 2007 we reported on the appropriate topics for the lectures and labs. In this third paper we first give an overview based on the 12-year EDA cycle on why FPGAs have now reached a level where SOPC design is possible and why MatLab/Simulink is favored by both leaders in the FPGA field: Altera (DSP builder) and Xilinx (System Generator). We then describe the Xilinx Blackboard educational material development (EMD) that has been used in Spring 2007 and Spring 2008 to teach a Xilinx System Generator based course and laboratory.

  8. Hardware design and implementation of fast DOA estimation method based on multicore DSP

    NASA Astrophysics Data System (ADS)

    Guo, Rui; Zhao, Yingxiao; Zhang, Yue; Lin, Qianqiang; Chen, Zengping

    2016-10-01

    In this paper, we present a high-speed real-time signal processing hardware platform based on multicore digital signal processor (DSP). The real-time signal processing platform shows several excellent characteristics including high performance computing, low power consumption, large-capacity data storage and high speed data transmission, which make it able to meet the constraint of real-time direction of arrival (DOA) estimation. To reduce the high computational complexity of DOA estimation algorithm, a novel real-valued MUSIC estimator is used. The algorithm is decomposed into several independent steps and the time consumption of each step is counted. Based on the statistics of the time consumption, we present a new parallel processing strategy to distribute the task of DOA estimation to different cores of the real-time signal processing hardware platform. Experimental results demonstrate that the high processing capability of the signal processing platform meets the constraint of real-time direction of arrival (DOA) estimation.

  9. Real-time blind image deconvolution based on coordinated framework of FPGA and DSP

    NASA Astrophysics Data System (ADS)

    Wang, Ze; Li, Hang; Zhou, Hua; Liu, Hongjun

    2015-10-01

    Image restoration takes a crucial place in several important application domains. With the increasing of computation requirement as the algorithms become much more complexity, there has been a significant rise in the need for accelerating implementation. In this paper, we focus on an efficient real-time image processing system for blind iterative deconvolution method by means of the Richardson-Lucy (R-L) algorithm. We study the characteristics of algorithm, and an image restoration processing system based on the coordinated framework of FPGA and DSP (CoFD) is presented. Single precision floating-point processing units with small-scale cascade and special FFT/IFFT processing modules are adopted to guarantee the accuracy of the processing. Finally, Comparing experiments are done. The system could process a blurred image of 128×128 pixels within 32 milliseconds, and is up to three or four times faster than the traditional multi-DSPs systems.

  10. Design of adaptive filter amplifier in UV communication based on DSP

    NASA Astrophysics Data System (ADS)

    Lv, Zhaoshun; Wu, Hanping; Li, Junyu

    2016-10-01

    According to the problem of the weak signal at receiving end in UV communication, we design a high gain, continuously adjustable adaptive filter amplifier. Based on proposing overall technical indicators and analyzing its working principle of the signal amplifier, we use chip LMH6629MF and two chips of AD797BN to achieve three-level cascade amplification. And apply hardware of DSP TMS320VC5509A to implement digital filtering. Design and verification by Multisim, Protel 99SE and CCS, the results show that: the amplifier can realize continuously adjustable amplification from 1000 to 10000 times without distortion. Magnification error is <=%4@1000 10000. And equivalent input noise voltage of amplification circuit is <=6 nV/ √Hz @30KHz 45KHz, and realizing function of adaptive filtering. The design provides theoretical reference and technical support for the UV weak signal processing.

  11. Measure and Control Technology Based on DSP for HighPrecision Scanning Motor

    NASA Astrophysics Data System (ADS)

    Yang, N.; Yang, X. Y.; Wu, B.; Ye, S. H.

    2006-10-01

    A welding seam tracking visual sensor based on laser scanning is designed to solve the problems, such as indistinct image, difficulty in processing image etc., caused by serious arc light interference during welding. This visual sensor is mainly composed of a scanning motor, a linear-array CCD, a scanning rotating mirror and a semiconductor laser. Because the sensor measurement precision relies dramatically on the rotate speed stability of the scanning motor, the crux in the sensor design is to control the rotate speed of the scanning motor. Selecting a brushless direct current motor as the scanning motor and using TMS320F2812 DSP to drive it, we adopted fuzzy algorithm to control the motor rotate speed and made the steadiness error of the rotate speed less than 0.5%, which guarantees the sensor measurement precision and is of great importance for enhancing the welding quality of the industry welding robot.

  12. DSP-based high precision real-time inline PMD monitoring

    NASA Astrophysics Data System (ADS)

    Yuan, Xueguang; Zhang, Yangan; Zhang, MingLun; Zhang, Jinnan; Huang, Yongqing

    2010-12-01

    Polarization mode dispersion is considered to be one of the main obstacles for high speed long-haul optical fiber communication systems. It is necessary to realize PMD monitoring. This paper theoretically analyzed the principle of polarization mode dispersion monitoring with degree of polarization as monitoring signal. Using the degree of polarization method, the scheme of DSP based high precision real-time inline PMD monitoring is designed and implemented. An experiment system is set up to monitor polarization mode dispersion of 40Gbit/s DQPSK system. The experiment results show that the range of input optical power is -20~0dBm, the response time is 1μs and the states of polarization accuracy degree is 1%. It has high sensitivity and can be used in a variety of modulation formats and it is independent of optical signal rate.

  13. [The acquisition and analysis of heart sound signals based on DSP].

    PubMed

    Xing, Suxia; Chen, Tianhua

    2011-04-01

    Heart sound signals acquisition is the primary basis for achieving non-invasive diagnosis of coronary heart disease. In this paper, a digital signal processor (DSP)-based on miniaturized circuit of heart sound signals acquisition and analysis platform was designed to achieve the functions of filtering, collecting, processing, displaying and the communicating with PC. With the self-developed experimental platform, we collected 228 cases of heart sounds of clinical data, and processed the signals using de-noising method with wavelet transform. These experimental results indicated that the db6 wavelet has the most obvious de-noising effect among the four most commonly used wavelets, i.e., haar, db6, sym8, and coif5. One wavelet at different levels possessed different de-noising effects, with level-5 db6 decomposition obtaining the most desirable result.

  14. DSP based lunar sampling control system for the coiling-type sampler

    NASA Astrophysics Data System (ADS)

    Ling, Yun; Song, Aiguo; Lu, Wei

    2011-12-01

    The paper develops a control system based on DSP28334 for lunar sampling, and provides the main structure of it. The critical hardware and software design of the system are introduced in detail. The emphasis is placed on the design and realization of the vibration control of the coiling-type sampler in the process of lunar sampling. A control strategy which combines manual-control and local autonomous control is applied for the lunar sampling control. And the sampling mechanism being controlled can realizes multi-motor units working at time-sharing, which reduces the power comsumption and increases the stability of the sampling system greatly. The practical application of the control strategy used for the coiling-type sampler is verified by the finite element analysis. The experiments results show that the system works with low power consumption and high efficiency, and the proposed strategy enables greater depth and better efficiency during sampling.

  15. Design of thin-film filters for resolution improvements in filter-array based spectrometers using DSP

    NASA Astrophysics Data System (ADS)

    Lee, Woong-Bi; Kim, Cheolsun; Ju, Gun Wu; Lee, Yong Tak; Lee, Heung-No

    2016-05-01

    Miniature spectrometers have been widely developed in various academic and industrial applications such as bio-medical, chemical and environmental engineering. As a family of spectrometers, optical filter-array based spectrometers fabricated using CMOS or Nano technology provide miniaturization, superior portability and cost effectiveness. In filterarray based spectrometers, the resolution which represents the ability how closely resolve two neighboring spectra, depends on the number of filters and the characteristics of the transmission functions (TFs) of the filters. In practice, due to the small-size and low-cost fabrication, the number of filters is limited and the shape of the TF of each filter is nonideal. As a development of modern digital signal processing (DSP), the spectrometers are equipped with DSP algorithms not only to alleviate distortions due to unexpected noise or interferences among filters but also reconstruct the original signal spectrum. For a high-resolution spectrum reconstruction by the DSP, the TFs of the filters need to be sufficiently uncorrelated with each other. In this paper, we present a design of optical thin-film filters which have the uncorrelated TFs. Each filter consists of multiple layers of high- and low-refractive index materials deposited on a substrate. The proposed design helps the DSP algorithm to improve resolution with a small number of filters. We demonstrate that a resolution of 5 nm within a range from 500 nm to 1100 nm can be achieved with only 64 filters.

  16. Robust observer-based adaptive fuzzy sliding mode controller

    NASA Astrophysics Data System (ADS)

    Oveisi, Atta; Nestorović, Tamara

    2016-08-01

    In this paper, a new observer-based adaptive fuzzy integral sliding mode controller is proposed based on the Lyapunov stability theorem. The plant is subjected to a square-integrable disturbance and is assumed to have mismatch uncertainties both in state- and input-matrices. Based on the classical sliding mode controller, the equivalent control effort is obtained to satisfy the sufficient requirement of sliding mode controller and then the control law is modified to guarantee the reachability of the system trajectory to the sliding manifold. In order to relax the norm-bounded constrains on the control law and solve the chattering problem of sliding mode controller, a fuzzy logic inference mechanism is combined with the controller. An adaptive law is then introduced to tune the parameters of the fuzzy system on-line. Finally, for evaluating the controller and the robust performance of the closed-loop system, the proposed regulator is implemented on a real-time mechanical vibrating system.

  17. Adaptive robust controller based on integral sliding mode concept

    NASA Astrophysics Data System (ADS)

    Taleb, M.; Plestan, F.

    2016-09-01

    This paper proposes, for a class of uncertain nonlinear systems, an adaptive controller based on adaptive second-order sliding mode control and integral sliding mode control concepts. The adaptation strategy solves the problem of gain tuning and has the advantage of chattering reduction. Moreover, limited information about perturbation and uncertainties has to be known. The control is composed of two parts: an adaptive one whose objective is to reject the perturbation and system uncertainties, whereas the second one is chosen such as the nominal part of the system is stabilised in zero. To illustrate the effectiveness of the proposed approach, an application on an academic example is shown with simulation results.

  18. Teaching Physical Based Animation via OpenGL Slides

    NASA Astrophysics Data System (ADS)

    Song, Miao; Mokhov, Serguei A.; Grogono, Peter

    This work expands further our earlier poster presentation and integration of the OpenGL Slides Framework (OGLSF) - to make presentations with real-time animated graphics where each slide is a scene with tidgets - and physical based animation of elastic two-, three-layer softbody objects. The whole project is very interactive, and serves dual purpose - delivering the teaching material in a classroom setting with real running animated examples as well as releasing the source code to the students to show how the actual working things are made.

  19. A Design of Low Frequency Time-Code Receiver Based on DSP and FPGA

    NASA Astrophysics Data System (ADS)

    Li, Guo-Dong; Xu, Lin-Sheng

    2006-06-01

    The hardware of a low frequency time-code receiver which was designed with FPGA (field programmable gate array) and DSP (digital signal processor) is introduced. The method of realizing the time synchronization for the receiver system is described. The software developed for DSP and FPGA is expounded, and the results of test and simulation are presented. The design is charcterized by high accuracy, good reliability, fair extensibility, etc.

  20. Feasibility Study on a Portable Field Pest Classification System Design Based on DSP and 3G Wireless Communication Technology

    PubMed Central

    Han, Ruizhen; He, Yong; Liu, Fei

    2012-01-01

    This paper presents a feasibility study on a real-time in field pest classification system design based on Blackfin DSP and 3G wireless communication technology. This prototype system is composed of remote on-line classification platform (ROCP), which uses a digital signal processor (DSP) as a core CPU, and a host control platform (HCP). The ROCP is in charge of acquiring the pest image, extracting image features and detecting the class of pest using an Artificial Neural Network (ANN) classifier. It sends the image data, which is encoded using JPEG 2000 in DSP, to the HCP through the 3G network at the same time for further identification. The image transmission and communication are accomplished using 3G technology. Our system transmits the data via a commercial base station. The system can work properly based on the effective coverage of base stations, no matter the distance from the ROCP to the HCP. In the HCP, the image data is decoded and the pest image displayed in real-time for further identification. Authentication and performance tests of the prototype system were conducted. The authentication test showed that the image data were transmitted correctly. Based on the performance test results on six classes of pests, the average accuracy is 82%. Considering the different live pests’ pose and different field lighting conditions, the result is satisfactory. The proposed technique is well suited for implementation in field pest classification on-line for precision agriculture. PMID:22736996

  1. Feasibility study on a portable field pest classification system design based on DSP and 3G wireless communication technology.

    PubMed

    Han, Ruizhen; He, Yong; Liu, Fei

    2012-01-01

    This paper presents a feasibility study on a real-time in field pest classification system design based on Blackfin DSP and 3G wireless communication technology. This prototype system is composed of remote on-line classification platform (ROCP), which uses a digital signal processor (DSP) as a core CPU, and a host control platform (HCP). The ROCP is in charge of acquiring the pest image, extracting image features and detecting the class of pest using an Artificial Neural Network (ANN) classifier. It sends the image data, which is encoded using JPEG 2000 in DSP, to the HCP through the 3G network at the same time for further identification. The image transmission and communication are accomplished using 3G technology. Our system transmits the data via a commercial base station. The system can work properly based on the effective coverage of base stations, no matter the distance from the ROCP to the HCP. In the HCP, the image data is decoded and the pest image displayed in real-time for further identification. Authentication and performance tests of the prototype system were conducted. The authentication test showed that the image data were transmitted correctly. Based on the performance test results on six classes of pests, the average accuracy is 82%. Considering the different live pests' pose and different field lighting conditions, the result is satisfactory. The proposed technique is well suited for implementation in field pest classification on-line for precision agriculture.

  2. The design and implementation of signal decomposition system of CL multi-wavelet transform based on DSP builder

    NASA Astrophysics Data System (ADS)

    Huang, Yan; Wang, Zhihui

    2015-12-01

    With the development of FPGA, DSP Builder is widely applied to design system-level algorithms. The algorithm of CL multi-wavelet is more advanced and effective than scalar wavelets in processing signal decomposition. Thus, a system of CL multi-wavelet based on DSP Builder is designed for the first time in this paper. The system mainly contains three parts: a pre-filtering subsystem, a one-level decomposition subsystem and a two-level decomposition subsystem. It can be converted into hardware language VHDL by the Signal Complier block that can be used in Quartus II. After analyzing the energy indicator, it shows that this system outperforms Daubenchies wavelet in signal decomposition. Furthermore, it has proved to be suitable for the implementation of signal fusion based on SoPC hardware, and it will become a solid foundation in this new field.

  3. Linear-grating triboelectric generator based on sliding electrification.

    PubMed

    Zhu, Guang; Chen, Jun; Liu, Ying; Bai, Peng; Zhou, Yu Sheng; Jing, Qingshen; Pan, Caofeng; Wang, Zhong Lin

    2013-05-08

    The triboelectric effect is known for many centuries and it is the cause of many charging phenomena. However, it has not been utilized for energy harvesting until very recently. (1-5) Here we developed a new principle of triboelectric generator (TEG) based on a fully contacted, sliding electrification process, which lays a fundamentally new mechanism for designing universal, high-performance TEGs to harvest diverse forms of mechanical energy in our daily life. Relative displacement between two sliding surfaces of opposite triboelectric polarities generates uncompensated surface triboelectric charges; the corresponding polarization created a voltage drop that results in a flow of induced electrons between electrodes. Grating of linear rows on the sliding surfaces enables substantial enhancements of total charges, output current, and current frequency. The TEG was demonstrated to be an efficient power source for simultaneously driving a number of small electronics. The principle established in this work can be applied to TEGs of different configurations that accommodate the needs of harvesting energy and/or sensing from diverse mechanical motions, such as contacted sliding, lateral translation, and rotation/rolling.

  4. Design of a hand-shape acquisition and recognition system based on DSP

    NASA Astrophysics Data System (ADS)

    Li, Wenwen; Liu, Fu; Gao, Lei

    2013-10-01

    In this paper, we design a hand-shape image acquisition and processing system based on DSP for solving the problem of hand-shape recognition. Acquisition configuration was designed, and the key parts (encoder, decoder, memory chip etc.) are selected. And a new method for hand-shape recognition based on wavelet moment is presented to overcome some shortage in present method for hand shape recognition. Firstly, image processing including binary processing and segment of hand silhouette are used, and then translation and scale normalization algorithms is implemented on the palms and fingers image. After that the wavelet moment characteristics of image are extracted. At last, support vector is achieved by training 100 images data in images database, 10 testing images were selected randomly to verify validity and feasibility of algorithms. Experimental results indicate that the 10 testing images are all classified correctly. The new method of extracting hand shape wavelet moment as characteristic matrix is easy to realize with characteristic of high utility and accuracy, and solve the problem of translation, rotation and scaling during the image acquisition process without positioning aids.

  5. Base-sequence-dependent sliding of proteins on DNA.

    PubMed

    Barbi, M; Place, C; Popkov, V; Salerno, M

    2004-10-01

    The possibility that the sliding motion of proteins on DNA is influenced by the base sequence through a base pair reading interaction, is considered. Referring to the case of the T7 RNA-polymerase, we show that the protein should follow a noise-influenced sequence-dependent motion which deviate from the standard random walk usually assumed. The general validity and the implications of the results are discussed.

  6. [Development of a video image system for wireless capsule endoscopes based on DSP].

    PubMed

    Yang, Li; Peng, Chenglin; Wu, Huafeng; Zhao, Dechun; Zhang, Jinhua

    2008-02-01

    A video image recorder to record video picture for wireless capsule endoscopes was designed. TMS320C6211 DSP of Texas Instruments Inc. is the core processor of this system. Images are periodically acquired from Composite Video Broadcast Signal (CVBS) source and scaled by video decoder (SAA7114H). Video data is transported from high speed buffer First-in First-out (FIFO) to Digital Signal Processor (DSP) under the control of Complex Programmable Logic Device (CPLD). This paper adopts JPEG algorithm for image coding, and the compressed data in DSP was stored to Compact Flash (CF) card. TMS320C6211 DSP is mainly used for image compression and data transporting. Fast Discrete Cosine Transform (DCT) algorithm and fast coefficient quantization algorithm are used to accelerate operation speed of DSP and decrease the executing code. At the same time, proper address is assigned for each memory, which has different speed;the memory structure is also optimized. In addition, this system uses plenty of Extended Direct Memory Access (EDMA) to transport and process image data, which results in stable and high performance.

  7. Simultaneous and independent multi-parameter monitoring with fault localization for DSP-based coherent communication systems.

    PubMed

    Shen, Thomas Shun Rong; Lau, Alan Pak Tao; Yu, Changyuan

    2010-11-08

    Digital signal processing (DSP)-based coherent communications have become standard for future high-speed optical networks. Implementing DSP-based advanced algorithms for data detection requires much more detailed knowledge of the transmission link parameters, resulting in optical performance monitoring (OPM) being even more important for next generation systems. At the same time, the DSP platform also enables new strategies for OPM. In this paper, we propose the use of pilot symbols with alternating power levels and study the statistics of the received power and phase difference to simultaneously and independently monitor the carrier frequency offset between transmitter and receiver laser, laser linewidth, number of spans, fiber nonlinearity parameters as well as optical signal-to-noise ratio (OSNR) of a transmission link. Analytical predictions are verified by simulation results for systems with full chromatic dispersion (CD) compensation per span and 10% CD under-compensation per span. In addition, we show that by monitoring the changes in the statistics of the received pilot symbols during network operation, one can locate faults or OSNR degradations along a transmission link without additional monitoring equipments at intermediate nodes, which may be useful for more efficient dynamic routing and network management.

  8. DSP-based control of a high frequency three cell flying capacitor inverter

    NASA Astrophysics Data System (ADS)

    Flores-Fuentes, A. A.; Rossano-Díaz, I. O.; Peña-Eguiluz, R.; López-Callejas, R.; Mercado-Cabrera, A.; de la Piedad-Beneitez, A.; Barocio, S. R.; Valencia, R.

    2010-03-01

    The design, instrumentation and early operation results of a digitally controlled voltage source inverter (VSI) are described. This inverter has been structured from a three cell flying capacitor inverter (TCFCI). Two different inverter control modes - open-loop and closed-loop - are applied by a digital system based on a Texas Instrument TMS320C6713 digital signal processor (DSP) board. The VSI is able to generate AC voltage signals up to 120 V amplitudes at a maximal 6 A current, from ∼9 kHz to ∼60 kHz in ∼900 Hz steps in both controls by varying the signal period through the square-wave command strategy. The multi-cell structure of the inverter provides an output frequency nearly three times that of the TCFCI semiconductor commutation. The power output of the TCFCI can drive a high frequency step-up transformer which, in turn, is associated with a cylindrical reactor where dielectric barrier discharges (DBD) are conducted.

  9. Design and implementation of an early warning system in vehicle for road speed control hump based on DSP and CCD

    NASA Astrophysics Data System (ADS)

    Yang, Shuyi; Zhu, Pingyu; He, Yanfang; Wang, Le

    2011-12-01

    Road speed control humps have the effect of strengthening transportation safety by preventing traffic accidents. However, vehicles will produce strong mechanical vibrations when crossing speed control humps at high speed. These vibrations affect the passenger's comfort and cause machine parts damage. Early warning systems in vehicles for road speed control humps were designed based on DSP and CCD sensors. The system uses a CCD camera to take the picture of the road speed control humps. The image information is processed and recognised by DSP. Then the related voice and image information is given quickly and accurately after the system processes. This information will remind the driver to prepare for slowing down in good time, it makes them safe and comfortable to pass over the road speed control hump.TMS320DM642DSP early warning system in vehicles was illustrated from three aspects of the image collection module, the image discernment module and the early warning export module. TMS320C6x soft develop flow was introduced in this paper. The system has strong practicality, rapid response and well directed-viewing.

  10. DSP-Based dual-polarity mass spectrum pattern recognition for bio-detection

    SciTech Connect

    Riot, V; Coffee, K; Gard, E; Fergenson, D; Ramani, S; Steele, P

    2006-04-21

    The Bio-Aerosol Mass Spectrometry (BAMS) instrument analyzes single aerosol particles using a dual-polarity time-of-flight mass spectrometer recording simultaneously spectra of thirty to a hundred thousand points on each polarity. We describe here a real-time pattern recognition algorithm developed at Lawrence Livermore National Laboratory that has been implemented on a nine Digital Signal Processor (DSP) system from Signatec Incorporated. The algorithm first preprocesses independently the raw time-of-flight data through an adaptive baseline removal routine. The next step consists of a polarity dependent calibration to a mass-to-charge representation, reducing the data to about five hundred to a thousand channels per polarity. The last step is the identification step using a pattern recognition algorithm based on a library of known particle signatures including threat agents and background particles. The identification step includes integrating the two polarities for a final identification determination using a score-based rule tree. This algorithm, operating on multiple channels per-polarity and multiple polarities, is well suited for parallel real-time processing. It has been implemented on the PMP8A from Signatec Incorporated, which is a computer based board that can interface directly to the two one-Giga-Sample digitizers (PDA1000 from Signatec Incorporated) used to record the two polarities of time-of-flight data. By using optimized data separation, pipelining, and parallel processing across the nine DSPs it is possible to achieve a processing speed of up to a thousand particles per seconds, while maintaining the recognition rate observed on a non-real time implementation. This embedded system has allowed the BAMS technology to improve its throughput and therefore its sensitivity while maintaining a large dynamic range (number of channels and two polarities) thus maintaining the systems specificity for bio-detection.

  11. Passivity-based sliding mode control for a polytopic stochastic differential inclusion system.

    PubMed

    Liu, Leipo; Fu, Zhumu; Song, Xiaona

    2013-11-01

    Passivity-based sliding mode control for a polytopic stochastic differential inclusion (PSDI) system is considered. A control law is designed such that the reachability of sliding motion is guaranteed. Moreover, sufficient conditions for mean square asymptotic stability and passivity of sliding mode dynamics are obtained by linear matrix inequalities (LMIs). Finally, two examples are given to illustrate the effectiveness of the proposed method.

  12. High performance 3D adaptive filtering for DSP based portable medical imaging systems

    NASA Astrophysics Data System (ADS)

    Bockenbach, Olivier; Ali, Murtaza; Wainwright, Ian; Nadeski, Mark

    2015-03-01

    Portable medical imaging devices have proven valuable for emergency medical services both in the field and hospital environments and are becoming more prevalent in clinical settings where the use of larger imaging machines is impractical. Despite their constraints on power, size and cost, portable imaging devices must still deliver high quality images. 3D adaptive filtering is one of the most advanced techniques aimed at noise reduction and feature enhancement, but is computationally very demanding and hence often cannot be run with sufficient performance on a portable platform. In recent years, advanced multicore digital signal processors (DSP) have been developed that attain high processing performance while maintaining low levels of power dissipation. These processors enable the implementation of complex algorithms on a portable platform. In this study, the performance of a 3D adaptive filtering algorithm on a DSP is investigated. The performance is assessed by filtering a volume of size 512x256x128 voxels sampled at a pace of 10 MVoxels/sec with an Ultrasound 3D probe. Relative performance and power is addressed between a reference PC (Quad Core CPU) and a TMS320C6678 DSP from Texas Instruments.

  13. Quality assessment of confocal microscopy slide-based systems: instability.

    PubMed

    Zucker, Robert M

    2006-07-01

    All slide-based fluorescence cytometry detections systems basically include an excitation light source, intermediate optics, and a detection device (CCD or PMT). Occasionally, this equipment becomes unstable, generating unreliable and inferior data. A number of tests have been devised to evaluate equipment performance and instability. The following four instability tests are described: galvanometer scanning, stage drift, correct wavelength spectral detection, and long-term laser power. Quality assurance tests revealed that a confocal microscope can become unstable in the following parameters, yielding inaccurate data: laser power, PMTs functionality, spectrophotometer accuracy, galvanometer scanning and laser stability, and stage drift. Long-term laser power stability has been observed to vary greatly. Confocal systems can become unstable in the following parameters: long-term laser power, galvanometer scanning, spectrophotometer accuracy, and stage stability. Instability in any of these parameters will affect image quality. Laser power fluctuations result from either a defective Acousto-optic tunable filter or improper heat dissipation. Spectrophotometer instability will generate unreliable spectra data, extra light reflections, and poor image quality. Galvanometer scanning instability yields poor image quality while microscope stage drift results in a sample going out of the plane of focus. With minor modifications, these tests may be applicable to other slide-based systems. Copyright 2006 International Society for Analytical Cytology.

  14. Analysis and Synthesis of Memory-Based Fuzzy Sliding Mode Controllers.

    PubMed

    Zhang, Jinhui; Lin, Yujuan; Feng, Gang

    2015-12-01

    This paper addresses the sliding mode control problem for a class of Takagi-Sugeno fuzzy systems with matched uncertainties. Different from the conventional memoryless sliding surface, a memory-based sliding surface is proposed which consists of not only the current state but also the delayed state. Both robust and adaptive fuzzy sliding mode controllers are designed based on the proposed memory-based sliding surface. It is shown that the sliding surface can be reached and the closed-loop control system is asymptotically stable. Furthermore, to reduce the chattering, some continuous sliding mode controllers are also presented. Finally, the ball and beam system is used to illustrate the advantages and effectiveness of the proposed approaches. It can be seen that, with the proposed control approaches, not only can the stability be guaranteed, but also its transient performance can be improved significantly.

  15. A laser self-mixing interference vibrometer based on current modulation and DSP demodulation

    NASA Astrophysics Data System (ADS)

    Xia, Wei; Wang, Ming; Guo, Wenhua

    2010-11-01

    The modulation and demodulation technique of laser self-mixing interference vibrometer is researched in this paper. Combining with triangular current modulation and DSP demodulation technique, a new-type laser self-mixing interference vibrometer is designed to achieve non-contact vibration measurement of a target. Theoretical analysis, simulation results and error evaluation are presented in this paper. The vibration waveform is reconstructed with an accuracy of 0.325 micron in a wide dynamic range. Experiments results show a good agreement with the simulative results. The vibrometer is compact, inexpensive, self-aligning and can be applied to various vibration measurements for its simplicity.

  16. DSP-based CSO cancellation technique for RoF transmission system implemented by using directly modulated laser.

    PubMed

    Kim, Byung Gon; Bae, Sung Hyun; Kim, Hoon; Chung, Yun C

    2017-05-29

    We propose and demonstrate a simple composite second-order (CSO) cancellation technique based on the digital signal processing (DSP) for the radio-over-fiber (RoF) transmission system implemented by using directly modulated lasers (DMLs). When the RoF transmission system is implemented by using DMLs, its performance could be limited by the CSO distortions caused by the interplay between the DML's chirp and fiber's chromatic dispersion. We present the theoretical analysis of these nonlinear distortions and show that they can be suppressed at the receiver by using a simple DSP. To verify the effectiveness of the proposed technique, we demonstrate the transmission of twenty-four 100-MHz filtered orthogonal frequency-division multiplexing (f-OFDM) signals in 64 quadrature amplitude modulation (QAM) format over 20 km of the standard single-mode fiber (SSMF). The results show that, by using the proposed technique, we can suppress the CSO distortion components by >10 dB and achieve the error-vector magnitude performance better than 6% even after the 20-km long SSMF transmission.

  17. Multicell actuator based on a sliding mode control

    NASA Astrophysics Data System (ADS)

    Béthoux, O.; Barbot, J.-P.; Hilairet, M.

    2008-08-01

    This paper deals with reliability of motor drive systems. It focuses on the switching power converter which is the weakest drive part. It investigates a new architecture which provides intrinsic redundancy. The method used in this fault switch detection and diagnosis is based on a sliding mode observer. The original aspect of this new approach is that the observer influences the control algorithm in order to rule out or accept the possibility of the device failure. This leads to the right decision which induces the rebuilding of the converter topology. This fault tolerant control strategy assures continuous operation even though one switch failure occurs. This article has been submitted as part of “IET Colloquium on Reliability in Electromagnetic Systems”, 24 and 25 May 2007, Paris

  18. Real-time vessel image enhancement system with forward and backward diffusion based on DSP

    NASA Astrophysics Data System (ADS)

    Zhang, Zhao; Wang, An; Sun, Jian-Zhao; Xia, Ying-Wei; Zhang, Long; Liu, Yong

    2016-10-01

    In order to help medical personnel to make accurate clinical judgment, we built a DSP real-time image enhancement system to enhance and sharpening the hand vein distribution image. First, we use 760 nm and 960 nm mixed near-infrared light as the light source to decrease the skin scattering and absorption of the incident light, and gain a distinct original image. Then, we analyzed the vascular model in the multi-scale method, and using the vascular response function to take the place of gradient in diffusion equation, constructed the Forward And Backward Diffusion (FABD) coefficients. Then, we realized it in the DM642 DSP hardware platform; finally, the proposed enhancement algorithms implemented on the hardware platform, and compared with anisotropic diffusion algorithm and forward and backward diffusion algorithm. The results showed that, the proposed system to enhance the images standard deviation than the original increased by 11.4971, and increased by 2.2530 and 1.1500 than the anisotropic diffusion algorithm and forward and backward diffusion algorithm respectively. The proposed system's processing time was 28.0ms, and met real time requirements. The system was stable, reliable and met the medical needs.

  19. Practical and cost-efficient design of fingerprint recognition system based on DSP

    NASA Astrophysics Data System (ADS)

    Ran, Chongjie; Xie, Mei

    2007-12-01

    In this paper, a practical and cost-efficient fingerprint recognition system model is proposed. It completes the functions of capturing fingerprint image, data transmission and fingerprint recognition. This system consists of six modules: Management Module (including TMS320VC5502 DSP and memories), Fingerprint Sensor Module (used to collect fingerprint image), Output Module (the interface to control electronic lock), Human-Machine Communication Module (seven-segment LED and keyboard), Debugger Interface Module (JTAG), Power Manager and Power Switchover Module. Unlike other fingerprint recognition systems, this system takes TI C5502 as core processor. It is a high-performance, low-power and fixed-point DSP and the whole system power can be supplied by batteries. The whole system can work more than 10000 times with batteries. In addition, a Power Switch Module, which can automatic switch the ways of power supply between wall adapter and batteries, is proposed in this paper. Furthermore, some software optimization makes this system practical. The design not only simplifies system's structure and reduces the cost of hardware, but also decreases the consumption of system power and resources. So, this hardware system can be used in practical applications, such as portable identification device, fingerprint lock etc. This system is mainly designed for fingerprint lock in this paper.

  20. Real-time co-registered ultrasound and photoacoustic imaging system based on FPGA and DSP architecture

    NASA Astrophysics Data System (ADS)

    Alqasemi, Umar; Li, Hai; Aguirre, Andres; Zhu, Quing

    2011-03-01

    Co-registering ultrasound (US) and photoacoustic (PA) imaging is a logical extension to conventional ultrasound because both modalities provide complementary information of tumor morphology, tumor vasculature and hypoxia for cancer detection and characterization. In addition, both modalities are capable of providing real-time images for clinical applications. In this paper, a Field Programmable Gate Array (FPGA) and Digital Signal Processor (DSP) module-based real-time US/PA imaging system is presented. The system provides real-time US/PA data acquisition and image display for up to 5 fps* using the currently implemented DSP board. It can be upgraded to 15 fps, which is the maximum pulse repetition rate of the used laser, by implementing an advanced DSP module. Additionally, the photoacoustic RF data for each frame is saved for further off-line processing. The system frontend consists of eight 16-channel modules made of commercial and customized circuits. Each 16-channel module consists of two commercial 8-channel receiving circuitry boards and one FPGA board from Analog Devices. Each receiving board contains an IC† that combines. 8-channel low-noise amplifiers, variable-gain amplifiers, anti-aliasing filters, and ADC's‡ in a single chip with sampling frequency of 40MHz. The FPGA board captures the LVDSξ Double Data Rate (DDR) digital output of the receiving board and performs data conditioning and subbeamforming. A customized 16-channel transmission circuitry is connected to the two receiving boards for US pulseecho (PE) mode data acquisition. A DSP module uses External Memory Interface (EMIF) to interface with the eight 16-channel modules through a customized adaptor board. The DSP transfers either sub-beamformed data (US pulse-echo mode or PAI imaging mode) or raw data from FPGA boards to its DDR-2 memory through the EMIF link, then it performs additional processing, after that, it transfer the data to the PC** for further image processing. The PC code

  1. DLP/DSP-based optical 3D sensors for the mass market in industrial metrology and life sciences

    NASA Astrophysics Data System (ADS)

    Frankowski, G.; Hainich, R.

    2011-03-01

    GFM has developed and constructed DLP-based optical 3D measuring devices based on structured light illumination. Over the years the devices have been used in industrial metrology and life sciences for different 3D measuring tasks. This lecture will discuss integration of DLP Pico technology and DSP technology from Texas Instruments for mass market optical 3D sensors. In comparison to existing mass market laser triangulation sensors, the new 3D sensors provide a full-field measurement of up to a million points in less than a second. The lecture will further discuss different fields of application and advantages of the new generation of 3D sensors for: OEM application in industrial measuring and inspection; 3D metrology in industry, life sciences and biometrics, and industrial image processing.

  2. Projective synchronization of nonidentical fractional-order neural networks based on sliding mode controller.

    PubMed

    Ding, Zhixia; Shen, Yi

    2016-04-01

    This paper investigates global projective synchronization of nonidentical fractional-order neural networks (FNNs) based on sliding mode control technique. We firstly construct a fractional-order integral sliding surface. Then, according to the sliding mode control theory, we design a sliding mode controller to guarantee the occurrence of the sliding motion. Based on fractional Lyapunov direct methods, system trajectories are driven to the proposed sliding surface and remain on it evermore, and some novel criteria are obtained to realize global projective synchronization of nonidentical FNNs. As the special cases, some sufficient conditions are given to ensure projective synchronization of identical FNNs, complete synchronization of nonidentical FNNs and anti-synchronization of nonidentical FNNs. Finally, one numerical example is given to demonstrate the effectiveness of the obtained results.

  3. Active magnetic bearing system based on sliding mode control

    NASA Astrophysics Data System (ADS)

    Zhang, Yanhong

    2017-07-01

    A new sliding mode variable structure control algorithm suitable for active magnetic bearing is proposed, which is widely used for nonlinear control system. The model and controller is designed, simulation and experimental parts are also made, according to the switching function and the sliding mode control law. The current of electromagnet is adjusted to realize stable levitation of the rotor. The experimental result shows that the sliding mode variable structure controller is an effective way for magnetic bearing control, and the active magnetic bearing system is a highly nonlinear and advanced control method that can reduce the setting time and the cost.

  4. Analysis of DSP-based longitudinal feedback system: Trials at SPEAR and ALS

    SciTech Connect

    Hindi, H.; Eisen, N.; Fox, J.; Linscott, I.; Oxoby, G.; Sapozhnikov, L.; Serio, M.

    1993-04-01

    Recently a single-channel prototype of the proposed PEP-II longitudinal feedback system was successfully demonstrated at SPEAR and ALS on single-bunch beams. The phase oscillations are detected via a wide-band pick up. The feedback signal is then computed using a digital signal processor (DSP) and applied to the beam by phase modulating the rf. We analyze results in the frequency- and the time-domain and show how the closed-loop transfer functions can be obtained rigorously by proper modeling of the various components of this hybrid continuous/digital system. The technique of downsampling was used in the experiments to reduce the number of computations and allowed the use of the same digital hardware on both machines.

  5. Research of real-time wavefront reconstruction and control based on multi-core DSP

    NASA Astrophysics Data System (ADS)

    Wang, Zhui; Zhou, Luchun; Li, Mei; Zhang, Haotian

    2014-09-01

    In an Adaptive Optics system, the Real Time Processor is as important as the human brain. Processing latency is a key index of Real Time Proceesors . In this paper, we propose a new processing method that significantly reduce the processing latency, which combined the design idea of multi-core parallel processing on space and time. In addition, by comparing the operating speed of CPU and the I/O speed of memory, we propose a reasonable memory allocation scheme. The experimental results show that the processing latency is 59.7us per frame using multi-core DSP TMS320C6678 as processing platform. The experiment is conducted on a system with 968 sub-apertures and 913 actuators.

  6. Robustness and Actuator Bandwidth of MRP-Based Sliding Mode Control for Spacecraft Attitude Control Problems

    NASA Astrophysics Data System (ADS)

    Keum, Jung-Hoon; Ra, Sung-Woong

    2009-12-01

    Nonlinear sliding surface design in variable structure systems for spacecraft attitude control problems is studied. A robustness analysis is performed for regular form of system, and calculation of actuator bandwidth is presented by reviewing sliding surface dynamics. To achieve non-singular attitude description and minimal parameterization, spacecraft attitude control problems are considered based on modified Rodrigues parameters (MRP). It is shown that the derived controller ensures the sliding motion in pre-determined region irrespective of unmodeled effects and disturbances.

  7. Sex determination using the Probabilistic Sex Diagnosis (DSP: Diagnose Sexuelle Probabiliste) tool in a virtual environment.

    PubMed

    Chapman, Tara; Lefevre, Philippe; Semal, Patrick; Moiseev, Fedor; Sholukha, Victor; Louryan, Stéphane; Rooze, Marcel; Van Sint Jan, Serge

    2014-01-01

    The hip bone is one of the most reliable indicators of sex in the human body due to the fact it is the most dimorphic bone. Probabilistic Sex Diagnosis (DSP: Diagnose Sexuelle Probabiliste) developed by Murail et al., in 2005, is a sex determination method based on a worldwide hip bone metrical database. Sex is determined by comparing specific measurements taken from each specimen using sliding callipers and computing the probability of specimens being female or male. In forensic science it is sometimes not possible to sex a body due to corpse decay or injury. Skeletalization and dissection of a body is a laborious process and desecrates the body. There were two aims to this study. The first aim was to examine the accuracy of the DSP method in comparison with a current visual sexing method on sex determination. A further aim was to see if it was possible to virtually utilise the DSP method on both the hip bone and the pelvic girdle in order to utilise this method for forensic sciences. For the first part of the study, forty-nine dry hip bones of unknown sex were obtained from the Body Donation Programme of the Université Libre de Bruxelles (ULB). A comparison was made between DSP analysis and visual sexing on dry bone by two researchers. CT scans of bones were then analysed to obtain three-dimensional (3D) virtual models and the method of DSP was analysed virtually by importing the models into a customised software programme called lhpFusionBox which was developed at ULB. The software enables DSP distances to be measured via virtually-palpated bony landmarks. There was found to be 100% agreement of sex between the manual and virtual DSP method. The second part of the study aimed to further validate the method by analysing thirty-nine supplementary pelvic girdles of known sex blind. There was found to be a 100% accuracy rate further demonstrating that the virtual DSP method is robust. Statistically significant differences were found in the identification of sex

  8. WEBSLIDE: A "Virtual" Slide Projector Based on World Wide Web

    NASA Astrophysics Data System (ADS)

    Barra, Maria; Ferrandino, Salvatore; Scarano, Vittorio

    1999-03-01

    We present here the design key concepts of WEBSLIDE, a software project whose objective is to provide a simple, cheap and efficient solution for showing slides during lessons in computer labs. In fact, WEBSLIDE allows the video monitors of several client machines (the "STUDENTS") to be synchronously updated by the actions of a particular client machine, called the "INSTRUCTOR." The system is based on the World Wide Web and the software components of WEBSLIDE mainly consists in a WWW server, browsers and small Cgi-Bill scripts. What makes WEBSLIDE particularly appealing for small educational institutions is that WEBSLIDE is built with "off the shelf" products: it does not involve using a specifically designed program but any Netscape browser, one of the most popular browsers available on the market, is sufficient. Another possible use is to use our system to implement "guided automatic tours" through several pages or Intranets internal news bulletins: the company Web server can broadcast to all employees relevant information on their browser.

  9. DSP control of superconducting quantum interference devices

    SciTech Connect

    Bracht, R.R.; Kung, Pang-Jen; Lewis, P.S.; Flynn, E.R.

    1994-08-01

    Superconducting quantum interference devices (SQUIDS) are used to defect very law level magnetic fields. Los Alamos National Laboratory is involved in developing digital signal processing (DSP) based instrumentation for these devices in conjunction with detecting magnetic flux from the human brain. This field of application is known as magnetoencephalography (MEG). The magnetic signals generated by the brain are on the order of a billion times smaller than the earth`s magnetic field, yet they can readily be detected with these highly ,sensitive magnetic detectors. Los Alamos National Laboratory has developed and implemented DSP control of the SQUID system. This has been accomplished by using an AT&T DSP32C DSP in conjunction with dual 18 bit a-to-d and d-to-a converters. The DSP performs the signal demodulation by synchronously sampling the recovered signal and applying the appropriate full wave rectification. The signal is then integrated and filtered and applied to the output. Also, the modulation signal is generated with the DSP system. All of the flux lock loop electronics are replaced except for the low noise analog preamplifier at the front of the recovery components. The system has been tested with both an electronic SQUID simulator and a low temperature thin film SQUID from Conductus. A number of experiments have been performed to allow evaluation of the system improvement made possible by use of DSP control.

  10. Sliding mode output feedback control based on tracking error observer with disturbance estimator.

    PubMed

    Xiao, Lingfei; Zhu, Yue

    2014-07-01

    For a class of systems who suffers from disturbances, an original output feedback sliding mode control method is presented based on a novel tracking error observer with disturbance estimator. The mathematical models of the systems are not required to be with high accuracy, and the disturbances can be vanishing or nonvanishing, while the bounds of disturbances are unknown. By constructing a differential sliding surface and employing reaching law approach, a sliding mode controller is obtained. On the basis of an extended disturbance estimator, a creative tracking error observer is produced. By using the observation of tracking error and the estimation of disturbance, the sliding mode controller is implementable. It is proved that the disturbance estimation error and tracking observation error are bounded, the sliding surface is reachable and the closed-loop system is robustly stable. The simulations on a servomotor positioning system and a five-degree-of-freedom active magnetic bearings system verify the effect of the proposed method.

  11. Multi-DSP and FPGA based Multi-channel Direct IF/RF Digital receiver for atmospheric radar

    NASA Astrophysics Data System (ADS)

    Yasodha, Polisetti; Jayaraman, Achuthan; Kamaraj, Pandian; Durga rao, Meka; Thriveni, A.

    2016-07-01

    to DDC block, which down converts the data to base-band. The DDC block has NCO, mixer and two chains of Bessel filters (fifth order cascaded integration comb filter, two FIR filters, two half band filters and programmable FIR filters) for in-phase (I) and Quadrature phase (Q) channels. The NCO has 32 bits and is set to match the output frequency of ADC. Further, DDC down samples (decimation) the data and reduces the data rate to 16 MSPS. This data is further decimated and the data rate is reduced down to 4/2/1/0.5/0.25/0.125/0.0625 MSPS for baud lengths 0.25/0.5/1/2/4/8/16 μs respectively. The down sampled data is then fed to decoding block, which performs cross correlation to achieve pulse compression of the binary-phase coded data to obtain better range resolution with maximum possible height coverage. This step improves the signal power by a factor equal to the length of the code. Coherent integration block integrates the decoded data coherently for successive pulses, which improves the signal to noise ratio and reduces the data volume. DDC, decoding and coherent integration blocks are implemented in Xilinx vertex5 FPGA. Till this point, function of all six channels is same for DBS mode and multi-receiver modes. Data from vertex5 FPGA is transferred to PC via GbE-1 interface for multi-modes or to two Analog devices make ADSP-TS201 DSP chips (A and B), via link port for DBS mode. ADSP-TS201 chips perform the normalization, DC removal, windowing, FFT computation and spectral averaging on the data, which is transferred to storage/display PC via GbE-2 interface for real-time data display and data storing. Physical layer of GbE interface is implemented in an external chip (Marvel 88E1111) and MAC layer is implemented internal to vertex5 FPGA. The MCDRx has total 4 GB of DDR2 memory for data storage. Spartan6 FPGA is used for generating timing signals, required for basic operation of the radar and testing of the MCDRx.

  12. Real-time target detection technology of large view-field infrared image based on multicore DSP parallel processing

    NASA Astrophysics Data System (ADS)

    Sun, Gang; Liu, Songlin; Wang, Weihua; Chen, Zengping

    2013-10-01

    In order to implement real-time detection of hedgehopping target in large view-field infrared (LVIR) image, the paper proposes a fast algorithm flow to extract the target region of interest (ROI). The ground building region was rejected quickly and target ROI was segmented roughly through the background classification. Then the background image containing target ROI was matched with previous frame based on a mean removal normalized product correlation (MRNPC) similarity measure function. Finally, the target motion area was extracted by inter-frame difference in time domain. According to the proposed algorithm flow, this paper designs the high-speed real-time signal processing hardware platform based on FPGA + DSP, and also presents a new parallel processing strategy that called function-level and task-level, which could parallel process LVIR image by multi-core and multi-task. Experimental results show that the algorithm can extract low altitude aero target with complex background in large view effectively, and the new design hardware platform could implement real time processing of the IR image with 50000x288 pixels per second in large view-field infrared search system (LVIRSS).

  13. Modularized reconfigurable system for target recognition with multi-DSP processing

    NASA Astrophysics Data System (ADS)

    Li, Yun; Li, Huili; Xie, Xiaoming

    2013-10-01

    A modularized reconfigurable system for target recognition with multi-DSP processing is designed to reconfigure the target recognition modules and update the distributed target feature libraries through the serial channel to adapt to the varied application. The system is separated into three independent modules and two work modes running at different time slides based on project switch. The modularized reconfiguration module is designed as a minimum security kernel separated from the target recognition module to decrease their coupling and interrelationship. This kind of multi-project design based on cyclic redundancy check presents a more independent and reliable target recognition system with modularized reconfiguration ability.

  14. Tensor product model transformation based adaptive integral-sliding mode controller: equivalent control method.

    PubMed

    Zhao, Guoliang; Sun, Kaibiao; Li, Hongxing

    2013-01-01

    This paper proposes new methodologies for the design of adaptive integral-sliding mode control. A tensor product model transformation based adaptive integral-sliding mode control law with respect to uncertainties and perturbations is studied, while upper bounds on the perturbations and uncertainties are assumed to be unknown. The advantage of proposed controllers consists in having a dynamical adaptive control gain to establish a sliding mode right at the beginning of the process. Gain dynamics ensure a reasonable adaptive gain with respect to the uncertainties. Finally, efficacy of the proposed controller is verified by simulations on an uncertain nonlinear system model.

  15. Synchronization of uncertain time-varying network based on sliding mode control technique

    NASA Astrophysics Data System (ADS)

    Lü, Ling; Li, Chengren; Bai, Suyuan; Li, Gang; Rong, Tingting; Gao, Yan; Yan, Zhe

    2017-09-01

    We research synchronization of uncertain time-varying network based on sliding mode control technique. The sliding mode control technique is first modified so that it can be applied to network synchronization. Further, by choosing the appropriate sliding surface, the identification law of uncertain parameter, the adaptive law of the time-varying coupling matrix element and the control input of network are designed, it is sure that the uncertain time-varying network can synchronize effectively the synchronization target. At last, we perform some numerical simulations to demonstrate the effectiveness of the proposed results.

  16. Projective synchronization of uncertain scale-free network based on modified sliding mode control technique

    NASA Astrophysics Data System (ADS)

    Li, Chengren; Lü, Ling; Zhao, Guannan; Li, Gang; Tian, Jing; Gu, Jiajia; Wang, Zhouyang

    2017-05-01

    We modify sliding mode control technique from the synchronization of a single dynamic system to the synchronization of complex network. Projective synchronization of uncertain scale-free network is investigated based on modified sliding mode control technique. Further, the sliding surfaces, the identification laws of uncertain parameters and the control inputs are designed, and the condition of realizing projective synchronization of uncertain scale-free network is obtained. Finally, the Logistic systems with chaotic behavior are taken as nodes to constitute the scale-free network and the synchronization target. The simulation results show that the synchronization mechanism is effective.

  17. Tensor Product Model Transformation Based Adaptive Integral-Sliding Mode Controller: Equivalent Control Method

    PubMed Central

    Zhao, Guoliang; Li, Hongxing

    2013-01-01

    This paper proposes new methodologies for the design of adaptive integral-sliding mode control. A tensor product model transformation based adaptive integral-sliding mode control law with respect to uncertainties and perturbations is studied, while upper bounds on the perturbations and uncertainties are assumed to be unknown. The advantage of proposed controllers consists in having a dynamical adaptive control gain to establish a sliding mode right at the beginning of the process. Gain dynamics ensure a reasonable adaptive gain with respect to the uncertainties. Finally, efficacy of the proposed controller is verified by simulations on an uncertain nonlinear system model. PMID:24453897

  18. A variable size sliding window based frequent itemsets mining algorithm in data stream

    NASA Astrophysics Data System (ADS)

    Li, Haiqing; Wang, Lang

    2017-05-01

    Due to the unpredictability and the concept drift character of the data stream, the traditional sliding window is difficult to adapt to frequent itemsets mining in data stream. A new variable sliding window based VSW-SCPS algorithm is proposed. The algorithm maintains a tree structure of SCPS-tree in memory, which is the storage structure of sliding window. When data flowing in, the SCPS-tree will adjust dynamically, the window size will be adjusted by the detection of concept drift according to the result of FP-growth mining algorithm. Experimental results show that the proposed algorithm has good time efficiency.

  19. Finite time control for MIMO nonlinear system based on higher-order sliding mode.

    PubMed

    Liu, Xiangjie; Han, Yaozhen

    2014-11-01

    Considering a class of MIMO uncertain nonlinear system, a novel finite time stable control algorithm is proposed based on higher-order sliding mode concept. The higher-order sliding mode control problem of MIMO nonlinear system is firstly transformed into finite time stability problem of multivariable system. Then continuous control law, which can guarantee finite time stabilization of nominal integral chain system, is employed. The second-order sliding mode is used to overcome the system uncertainties. High frequency chattering phenomenon of sliding mode is greatly weakened, and the arbitrarily fast convergence is reached. The finite time stability is proved based on the quadratic form Lyapunov function. Examples concerning the triple integral chain system with uncertainty and the hovercraft trajectory tracking are simulated respectively to verify the effectiveness and the robustness of the proposed algorithm.

  20. Robust passive control for a class of uncertain neutral systems based on sliding mode observer.

    PubMed

    Liu, Zhen; Zhao, Lin; Kao, Yonggui; Gao, Cunchen

    2017-01-01

    The passivity-based sliding mode control (SMC) problem for a class of uncertain neutral systems with unmeasured states is investigated. Firstly, a particular non-fragile state observer is designed to generate the estimations of the system states, based upon which a novel integral-type sliding surface function is established for the control process. Secondly, a new sufficient condition for robust asymptotic stability and passivity of the resultant sliding mode dynamics (SMDs) is obtained in terms of linear matrix inequalities (LMIs). Thirdly, the finite-time reachability of the predesigned sliding surface is ensured by resorting to a novel adaptive SMC law. Finally, the validity and superiority of the scheme are justified via several examples.

  1. Optimal integral sliding mode control scheme based on pseudospectral method for robotic manipulators

    NASA Astrophysics Data System (ADS)

    Liu, Rongjie; Li, Shihua

    2014-06-01

    For a multi-input multi-output nonlinear system, an optimal integral sliding mode control scheme based on pseudospectral method is proposed in this paper. And the controller is applied on rigid robotic manipulators with constraints. First, a general form of integral sliding mode is designed with the aim of restraining disturbance. Then, pseudospectral method is adopted to deal with constrained optimal control problem. In consideration of the benefits of both methods, an optimal integral sliding mode controller is given, which is based on the combination of integral sliding mode and pseudospectral method. The stability analysis shows that the controller can guarantee stability of robotic manipulator system. Simulations show the effectiveness of proposed method.

  2. Disturbance observer based sliding mode control of active suspension systems

    NASA Astrophysics Data System (ADS)

    Deshpande, Vaijayanti S.; Mohan, B.; Shendge, P. D.; Phadke, S. B.

    2014-05-01

    In this paper, a novel scheme to reduce the acceleration of the sprung mass, used in combination with sliding mode control, is proposed. The proposed scheme estimates the effects of the uncertain, nonlinear spring and damper, load variation and the unknown road disturbance. The controller needs the states of sprung mass only, obviating the need to measure the states of the unsprung mass. The ultimate boundedness of the overall suspension system is proved. The efficacy of the method is verified through simulations for three different types of road profiles and load variation and the scheme is validated on an experimental setup. The results are compared with passive suspension system.

  3. An Application of Chaotic Chua's System for Secure Chaotic Communication Based on Sliding Mode observer

    NASA Astrophysics Data System (ADS)

    Kemih, K.; Halimi, M.; Ghanes, M.; Zhang, G.

    2011-12-01

    In this paper, we study the design and implementation of analog secure communication systems via synchronized chaotic Chua's circuit with sliding mode observer. For this, we adopt an approach based on an inclusion of the message in the transmitter and in the receiver; we use a sliding mode observer with un-known input in order to recover the information. Finally, an analog electronic circuit with Multisim software is designed to physically realize the complete system (transmitter-receiver).

  4. Simulation and Research of Control-System for PMSM Based on Sliding Mode Control

    NASA Astrophysics Data System (ADS)

    Baofeng, Lv; Guoxiang, Zhang

    In this paper, permanent magnet synchronous motor rotor flux oriented control strategy is studied, for the key issues of vector control is to observe the rotor flux, the control system is given based on sliding mode observer, and the sliding mode rotor flux observer is designed, with MATLAB/SIMULINK simulation, the results of simulation show that the system with wide speed range, has a good dynamic and static performance.

  5. Buckling of a Flexible Strip Sliding on a Frictional Base

    NASA Astrophysics Data System (ADS)

    Huynen, Alexandre; Marck, Julien; Denoel, Vincent; Detournay, Emmanuel

    2013-03-01

    The main motivation for this contribution is the buckling of a drillstring sliding on the bottom of the horizontal section of borehole. The open questions that remain today are related to the determination of the onset of instability, and to the conditions under which different modes of constrained buckling occur. In this presentation, we are concerned by a two-dimensional version of this problem; namely, the sliding of a flexible strip being fed inside a conduit. The ribbon, which has a flexural rigidity EI and a weight per unit length w, is treated as an inextensible elastica of negligible thickness. The contact between the ribbon and the wall of the conduit is characterized by a friction coefficient μ. First, we report the result of a stability analysis that aims at determining the critical inserted length of the ribbon l* (μ) (scaled by the characteristic length λ =(EI / w) 1 / 3) at which there is separation between the strip and the conduit bottom, as well as the buckling mode. Next, the relationship between the feeding force F and the inserted length l after bifurcation is computed. Finally, the results of a ``kitchen table'' experiment involving a strip of silicon rubber being pushed on a plank are reported and compared with predictions.

  6. Time-varying sliding-coefficient-based decoupled terminal sliding-mode control for a class of fourth-order systems.

    PubMed

    Bayramoglu, Husnu; Komurcugil, Hasan

    2014-07-01

    A time-varying sliding-coefficient-based decoupled terminal sliding mode control strategy is presented for a class of fourth-order systems. First, the fourth-order system is decoupled into two second-order subsystems. The sliding surface of each subsystem was designed by utilizing time-varying coefficients. Then, the control target of one subsystem to another subsystem was embedded. Thereafter, a terminal sliding mode control method was utilized to make both subsystems converge to their equilibrium points in finite time. The simulation results on the inverted pendulum system demonstrate that the proposed method exhibits a considerable improvement in terms of a faster dynamic response and lower IAE and ITAE values as compared with the existing decoupled control methods.

  7. Nonlinear adaptive control based on fuzzy sliding mode technique and fuzzy-based compensator.

    PubMed

    Nguyen, Sy Dzung; Vo, Hoang Duy; Seo, Tae-Il

    2017-09-01

    It is difficult to efficiently control nonlinear systems in the presence of uncertainty and disturbance (UAD). One of the main reasons derives from the negative impact of the unknown features of UAD as well as the response delay of the control system on the accuracy rate in the real time of the control signal. In order to deal with this, we propose a new controller named CO-FSMC for a class of nonlinear control systems subjected to UAD, which is constituted of a fuzzy sliding mode controller (FSMC) and a fuzzy-based compensator (CO). Firstly, the FSMC and CO are designed independently, and then an adaptive fuzzy structure is discovered to combine them. Solutions for avoiding the singular cases of the fuzzy-based function approximation and reducing the calculating cost are proposed. Based on the solutions, fuzzy sliding mode technique, lumped disturbance observer and Lyapunov stability analysis, a closed-loop adaptive control law is formulated. Simulations along with a real application based on a semi-active train-car suspension are performed to fully evaluate the method. The obtained results reflected that vibration of the chassis mass is insensitive to UAD. Compared with the other fuzzy sliding mode control strategies, the CO-FSMC can provide the best control ability to reduce unwanted vibrations. Copyright © 2017 ISA. Published by Elsevier Ltd. All rights reserved.

  8. Continuing Medical Education Speakers with High Evaluation Scores Use more Image-based Slides.

    PubMed

    Ferguson, Ian; Phillips, Andrew W; Lin, Michelle

    2017-01-01

    Although continuing medical education (CME) presentations are common across health professions, it is unknown whether slide design is independently associated with audience evaluations of the speaker. Based on the conceptual framework of Mayer's theory of multimedia learning, this study aimed to determine whether image use and text density in presentation slides are associated with overall speaker evaluations. This retrospective analysis of six sequential CME conferences (two annual emergency medicine conferences over a three-year period) used a mixed linear regression model to assess whether post-conference speaker evaluations were associated with image fraction (percentage of image-based slides per presentation) and text density (number of words per slide). A total of 105 unique lectures were given by 49 faculty members, and 1,222 evaluations (70.1% response rate) were available for analysis. On average, 47.4% (SD=25.36) of slides had at least one educationally-relevant image (image fraction). Image fraction significantly predicted overall higher evaluation scores [F(1, 100.676)=6.158, p=0.015] in the mixed linear regression model. The mean (SD) text density was 25.61 (8.14) words/slide but was not a significant predictor [F(1, 86.293)=0.55, p=0.815]. Of note, the individual speaker [χ(2)(1)=2.952, p=0.003] and speaker seniority [F(3, 59.713)=4.083, p=0.011] significantly predicted higher scores. This is the first published study to date assessing the linkage between slide design and CME speaker evaluations by an audience of practicing clinicians. The incorporation of images was associated with higher evaluation scores, in alignment with Mayer's theory of multimedia learning. Contrary to this theory, however, text density showed no significant association, suggesting that these scores may be multifactorial. Professional development efforts should focus on teaching best practices in both slide design and presentation skills.

  9. Continuing Medical Education Speakers with High Evaluation Scores Use more Image-based Slides

    PubMed Central

    Ferguson, Ian; Phillips, Andrew W.; Lin, Michelle

    2017-01-01

    Introduction Although continuing medical education (CME) presentations are common across health professions, it is unknown whether slide design is independently associated with audience evaluations of the speaker. Based on the conceptual framework of Mayer’s theory of multimedia learning, this study aimed to determine whether image use and text density in presentation slides are associated with overall speaker evaluations. Methods This retrospective analysis of six sequential CME conferences (two annual emergency medicine conferences over a three-year period) used a mixed linear regression model to assess whether post-conference speaker evaluations were associated with image fraction (percentage of image-based slides per presentation) and text density (number of words per slide). Results A total of 105 unique lectures were given by 49 faculty members, and 1,222 evaluations (70.1% response rate) were available for analysis. On average, 47.4% (SD=25.36) of slides had at least one educationally-relevant image (image fraction). Image fraction significantly predicted overall higher evaluation scores [F(1, 100.676)=6.158, p=0.015] in the mixed linear regression model. The mean (SD) text density was 25.61 (8.14) words/slide but was not a significant predictor [F(1, 86.293)=0.55, p=0.815]. Of note, the individual speaker [χ2(1)=2.952, p=0.003] and speaker seniority [F(3, 59.713)=4.083, p=0.011] significantly predicted higher scores. Conclusion This is the first published study to date assessing the linkage between slide design and CME speaker evaluations by an audience of practicing clinicians. The incorporation of images was associated with higher evaluation scores, in alignment with Mayer’s theory of multimedia learning. Contrary to this theory, however, text density showed no significant association, suggesting that these scores may be multifactorial. Professional development efforts should focus on teaching best practices in both slide design and presentation

  10. Two-Link Flexible Manipulator Control Using Sliding Mode Control Based Linear Matrix Inequality

    NASA Astrophysics Data System (ADS)

    Zulfatman; Marzuki, Mohammad; Alif Mardiyah, Nur

    2017-04-01

    Two-link flexible manipulator is a manipulator robot which at least one of its arms is made of lightweight material and not rigid. Flexible robot manipulator has some advantages over the rigid robot manipulator, such as lighter, requires less power and costs, and to result greater payload. However, suitable control algorithm to maintain the two-link flexible robot manipulator in accurate positioning is very challenging. In this study, sliding mode control (SMC) was employed as robust control algorithm due to its insensitivity on the system parameter variations and the presence of disturbances when the system states are sliding on a sliding surface. SMC algorithm was combined with linear matrix inequality (LMI), which aims to reduce the effects of chattering coming from the oscillation of the state during sliding on the sliding surface. Stability of the control algorithm is guaranteed by Lyapunov function candidate. Based on simulation works, SMC based LMI resulted in better performance improvements despite the disturbances with significant chattering reduction. This was evident from the decline of the sum of squared tracking error (SSTE) and the sum of squared of control input (SSCI) indexes respectively 25.4% and 19.4%.

  11. Testbed for development of a DSP-based signal processing subsystem for an Earth-orbiting radar scatterometer

    NASA Technical Reports Server (NTRS)

    Clark, Douglas J.; Lux, James P.; Shirbacheh, Mike

    2002-01-01

    A testbed for evaluation of general-purpose digital signal processors in earth-orbiting radar scatterometers is discussed. Because general purpose DSP represents a departure from previous radar signal processing techniques used on scatterometers, there was a need to demonstrate key elements of the system to verify feasibility for potential future scatterometer instruments. Construction of the testbed also facilitated identification of an appropriate software development environment and the skills mix necessary to perform the work.

  12. Testbed for development of a DSP-based signal processing subsystem for an Earth-orbiting radar scatterometer

    NASA Technical Reports Server (NTRS)

    Clark, Douglas J.; Lux, James P.; Shirbacheh, Mike

    2002-01-01

    A testbed for evaluation of general-purpose digital signal processors in earth-orbiting radar scatterometers is discussed. Because general purpose DSP represents a departure from previous radar signal processing techniques used on scatterometers, there was a need to demonstrate key elements of the system to verify feasibility for potential future scatterometer instruments. Construction of the testbed also facilitated identification of an appropriate software development environment and the skills mix necessary to perform the work.

  13. Demonstration of PMD compensation by using a DSP-Based OPMDC prototype in a 43-Gb/s RZ-DQPSK, 1200 km DWDM transmission

    NASA Astrophysics Data System (ADS)

    Zhang, Xiaoguang; Weng, Xuan; Tian, Feng; Zhang, Wenbo; Zhang, Yangan; Xi, Lixia; Zhang, Guangyong; Xiong, Qianjin

    2011-08-01

    This paper reports the DSP-based prototype compensator we have made to compensate the polarization mode dispersion (PMD) in fibers . It was tested in one channel of a 40 × 43-Gb/s DWDM DQPSK system, which is the commercial product line, either in the back-to-back case by using a PMD emulator, or in a 1200-km transmission testbed. The prototype showed a good performance under the tests of fast SOP and PSP rotation, DGD jump variation, and moderate knock on the testbed in a period as long as 12 h.

  14. Key Technologies Development of Transient Signals Based Protection Device Using DSP and S-Transform

    NASA Astrophysics Data System (ADS)

    Liu, Xingmao; Zheng, Gao

    2017-05-01

    The correctness of new principle of transient signal based protection used to be verified by simulating. In order to further introduce the dynamic simulation experiments for the transient signal based protection algorithm, the key technologies of transient signal based protection device were developed. The hardware of the synchronous multi-channel data acquisition and high-speed data processing was designed with kernel of high speed floating point digital signal processor TMS320C6748 and simultaneous sampling analog-to-digital converter. The sampling program reads the AD conversion data using DMA mode, which reduce the consumption of CPU time. The S transform was used to extract the fault traveling wave signals from the sampled data. The time consumption of algorithm which extract the traveling wave was analyzed when it ran on TMS320C6748. The test result shows that the hardware and software design is feasible.

  15. Comparison of advanced DSP techniques for spectrally efficient Nyquist-WDM signal generation using digital FIR filters at transmitters based on higher-order modulation formats

    NASA Astrophysics Data System (ADS)

    Weng, Yi; Wang, Junyi; Pan, Zhongqi

    2016-02-01

    To support the ever-increasing demand for high-speed optical communications, Nyquist spectral shaping serves as a promising technique to improve spectral efficiency (SE) by generating near-rectangular spectra with negligible crosstalk and inter-symbol interference in wavelength-division-multiplexed (WDM) systems. Compared with specially-designed optical methods, DSP-based electrical filters are more flexible as they can generate different filter shapes and modulation formats. However, such transmitter-side pre-filtering approach is sensitive to the limited taps of finite-impulse-response (FIR) filter, for the complexity of the required DSP and digital-to-analog converter (DAC) is limited by the cost and power consumption of optical transponder. In this paper, we investigate the performance and complexity of transmitter-side FIR-based DSP with polarization-division-multiplexing (PDM) high-order quadrature-amplitude-modulation (QAM) formats. Our results show that Nyquist 64-QAM, 16-QAM and QPSK WDM signals can be sufficiently generated by digital FIR filters with 57, 37, and 17 taps respectively. Then we explore the effects of the required spectral pre-emphasis, bandwidth and resolution on the performance of Nyquist-WDM systems. To obtain negligible OSNR penalty with a roll-off factor of 0.1, two-channel-interleaved DAC requires a Gaussian electrical filter with the bandwidth of 0.4-0.6 times of the symbol rate for PDM-64QAM, 0.35-0.65 times for PDM-16QAM, and 0.3-0.8 times for PDM-QPSK, with required DAC resolutions as 8, 7, 6 bits correspondingly. As a tradeoff, PDM-64QAM can be a promising candidate for SE improvement in next-generation optical metro networks.

  16. DSP-Based Hands-On Laboratory Experiments for Photovoltaic Power Systems

    ERIC Educational Resources Information Center

    Muoka, Polycarp I.; Haque, Md. Enamul; Gargoom, Ameen; Negnetvitsky, Michael

    2015-01-01

    This paper presents a new photovoltaic (PV) power systems laboratory module that was developed to experimentally reinforce students' understanding of design principles, operation, and control of photovoltaic power conversion systems. The laboratory module is project-based and is designed to support a renewable energy course. By using MATLAB…

  17. Embedded DSP-based telehealth radar system for remote in-door fall detection.

    PubMed

    Garripoli, Carmine; Mercuri, Marco; Karsmakers, Peter; Jack Soh, Ping; Crupi, Giovanni; Vandenbosch, Guy A E; Pace, Calogero; Leroux, Paul; Schreurs, Dominique

    2015-01-01

    Telehealth systems and applications are extensively investigated nowadays to enhance the quality-of-care and, in particular, to detect emergency situations and to monitor the well-being of elderly people, allowing them to stay at home independently as long as possible. In this paper, an embedded telehealth system for continuous, automatic, and remote monitoring of real-time fall emergencies is presented and discussed. The system, consisting of a radar sensor and base station, represents a cost-effective and efficient healthcare solution. The implementation of the fall detection data processing technique, based on the least-square support vector machines, through a digital signal processor and the management of the communication between radar sensor and base station are detailed. Experimental tests, for a total of 65 mimicked fall incidents, recorded with 16 human subjects (14 men and two women) that have been monitored for 320 min, have been used to validate the proposed system under real circumstances. The subjects' weight is between 55 and 90 kg with heights between 1.65 and 1.82 m, while their age is between 25 and 39 years. The experimental results have shown a sensitivity to detect the fall events in real time of 100% without reporting false positives. The tests have been performed in an area where the radar's operation was not limited by practical situations, namely, signal power, coverage of the antennas, and presence of obstacles between the subject and the antennas.

  18. DSP-based optical modulation technique for long-haul transmission

    NASA Astrophysics Data System (ADS)

    Yoshida, T.; Sugihara, T.; Uto, K.

    2015-01-01

    Fiber nonlinearity and equalization-enhanced phase noise (EEPN) generate rapid perturbations and critically limit the system capacity and range of long-haul optical transmission. It is possible to cancel the rapid perturbations by introducing a particular correlation between multiple signals at the transmitter and analyzing the received signals using digital signal processing. In this paper, we review our proposed techniques to cancel rapid perturbations of polarization multiplexed signals due to fiber nonlinearity and EEPN. Numerical simulation of quaternary phase-shift keying based signals shows 1.2 dB and 0.5 dB improvement respectively from the proposed cancellation techniques for fiber nonlinearity and EEPN.

  19. Adaptive Signal Processing Testbed: VME-based DSP board market survey

    NASA Astrophysics Data System (ADS)

    Ingram, Rick E.

    1992-04-01

    The Adaptive Signal Processing Testbed (ASPT) is a real-time multiprocessor system utilizing digital signal processor technology on VMEbus based printed circuit boards installed on a Sun workstation. The ASPT has specific requirements, particularly as regards to the signal excision application, with respect to interfacing with current and planned data generation equipment, processing of the data, storage to disk of final and intermediate results, and the development tools for applications development and integration into the overall EW/COM computing environment. A prototype ASPT was implemented using three VME-C-30 boards from Applied Silicon. Experience gained during the prototype development led to the conclusions that interprocessor communications capability is the most significant contributor to overall ASPT performance. In addition, the host involvement should be minimized. Boards using different processors were evaluated with respect to the ASPT system requirements, pricing, and availability. Specific recommendations based on various priorities are made as well as recommendations concerning the integration and interaction of various tools developed during the prototype implementation.

  20. Multi-mode sliding mode control for precision linear stage based on fixed or floating stator.

    PubMed

    Fang, Jiwen; Long, Zhili; Wang, Michael Yu; Zhang, Lufan; Dai, Xufei

    2016-02-01

    This paper presents the control performance of a linear motion stage driven by Voice Coil Motor (VCM). Unlike the conventional VCM, the stator of this VCM is regulated, which means it can be adjusted as a floating-stator or fixed-stator. A Multi-Mode Sliding Mode Control (MMSMC), including a conventional Sliding Mode Control (SMC) and an Integral Sliding Mode Control (ISMC), is designed to control the linear motion stage. The control is switched between SMC and IMSC based on the error threshold. To eliminate the chattering, a smooth function is adopted instead of a signum function. The experimental results with the floating stator show that the positioning accuracy and tracking performance of the linear motion stage are improved with the MMSMC approach.

  1. Multi-mode sliding mode control for precision linear stage based on fixed or floating stator

    NASA Astrophysics Data System (ADS)

    Fang, Jiwen; Long, Zhili; Wang, Michael Yu; Zhang, Lufan; Dai, Xufei

    2016-02-01

    This paper presents the control performance of a linear motion stage driven by Voice Coil Motor (VCM). Unlike the conventional VCM, the stator of this VCM is regulated, which means it can be adjusted as a floating-stator or fixed-stator. A Multi-Mode Sliding Mode Control (MMSMC), including a conventional Sliding Mode Control (SMC) and an Integral Sliding Mode Control (ISMC), is designed to control the linear motion stage. The control is switched between SMC and IMSC based on the error threshold. To eliminate the chattering, a smooth function is adopted instead of a signum function. The experimental results with the floating stator show that the positioning accuracy and tracking performance of the linear motion stage are improved with the MMSMC approach.

  2. Disturbance observer based sliding mode control of nonlinear mismatched uncertain systems

    NASA Astrophysics Data System (ADS)

    Ginoya, Divyesh; Shendge, P. D.; Phadke, S. B.

    2015-09-01

    This paper presents a new design of multiple-surface sliding mode control for a class of nonlinear uncertain systems with mismatched uncertainties and disturbances. In the method of multiple-surface sliding mode control, it is required to compensate for the derivatives of the virtual inputs which gives rise to the so-called problem of 'explosion of terms'. In this paper a disturbance observer based multiple-surface sliding mode control is proposed to estimate the uncertainties as well as the derivative of the virtual inputs to overcome this problem. The practical stability of the overall system is proved. The effectiveness of the proposed control strategy is illustrated via simulation of a benchmark problem and comparison with other control strategies. The proposed scheme is validated by implementing it on a serial flexible joint manipulator in the laboratory.

  3. Smith predictor based-sliding mode controller for integrating processes with elevated deadtime.

    PubMed

    Camacho, Oscar; De la Cruz, Francisco

    2004-04-01

    An approach to control integrating processes with elevated deadtime using a Smith predictor sliding mode controller is presented. A PID sliding surface and an integrating first-order plus deadtime model have been used to synthesize the controller. Since the performance of existing controllers with a Smith predictor decrease in the presence of modeling errors, this paper presents a simple approach to combining the Smith predictor with the sliding mode concept, which is a proven, simple, and robust procedure. The proposed scheme has a set of tuning equations as a function of the characteristic parameters of the model. For implementation of our proposed approach, computer based industrial controllers that execute PID algorithms can be used. The performance and robustness of the proposed controller are compared with the Matausek-Micić scheme for linear systems using simulations.

  4. Model-based Sliding Mode Controller of Anti-lock Braking System

    NASA Astrophysics Data System (ADS)

    Zheng, Lin; Luo, Yue-Gang; Kang, Jing; Shi, Zhan-Qun

    2016-05-01

    The anti-lock braking system (ABS) used in automobiles is used to prevent wheel from lockup and to maintain the steering ability and stability. The sliding mode controller is able to control nonlinear system steadily. In this research, a one-wheel dynamic model with ABS control is built up using model-based method. Using the sliding model controller, the simulation results by using Matlab/Simulink show qualified data compared with optimal slip rate. By using this method, the ABS brake efficiency is improved efficiently.

  5. Combination of statistical and physically based methods to assess shallow slide susceptibility at the basin scale

    NASA Astrophysics Data System (ADS)

    Oliveira, Sérgio C.; Zêzere, José L.; Lajas, Sara; Melo, Raquel

    2017-07-01

    Approaches used to assess shallow slide susceptibility at the basin scale are conceptually different depending on the use of statistical or physically based methods. The former are based on the assumption that the same causes are more likely to produce the same effects, whereas the latter are based on the comparison between forces which tend to promote movement along the slope and the counteracting forces that are resistant to motion. Within this general framework, this work tests two hypotheses: (i) although conceptually and methodologically distinct, the statistical and deterministic methods generate similar shallow slide susceptibility results regarding the model's predictive capacity and spatial agreement; and (ii) the combination of shallow slide susceptibility maps obtained with statistical and physically based methods, for the same study area, generate a more reliable susceptibility model for shallow slide occurrence. These hypotheses were tested at a small test site (13.9 km2) located north of Lisbon (Portugal), using a statistical method (the information value method, IV) and a physically based method (the infinite slope method, IS). The landslide susceptibility maps produced with the statistical and deterministic methods were combined into a new landslide susceptibility map. The latter was based on a set of integration rules defined by the cross tabulation of the susceptibility classes of both maps and analysis of the corresponding contingency tables. The results demonstrate a higher predictive capacity of the new shallow slide susceptibility map, which combines the independent results obtained with statistical and physically based models. Moreover, the combination of the two models allowed the identification of areas where the results of the information value and the infinite slope methods are contradictory. Thus, these areas were classified as uncertain and deserve additional investigation at a more detailed scale.

  6. Collaborative Paper-Based Annotation of Lecture Slides

    ERIC Educational Resources Information Center

    Steimle, Jurgen; Brdiczka, Oliver; Muhlhauser, Max

    2009-01-01

    In a study of notetaking in university courses, we found that the large majority of students prefer paper to computer-based media like Tablet PCs for taking notes and making annotations. Based on this finding, we developed CoScribe, a concept and system which supports students in making collaborative handwritten annotations on printed lecture…

  7. Collaborative Paper-Based Annotation of Lecture Slides

    ERIC Educational Resources Information Center

    Steimle, Jurgen; Brdiczka, Oliver; Muhlhauser, Max

    2009-01-01

    In a study of notetaking in university courses, we found that the large majority of students prefer paper to computer-based media like Tablet PCs for taking notes and making annotations. Based on this finding, we developed CoScribe, a concept and system which supports students in making collaborative handwritten annotations on printed lecture…

  8. Second-order sliding mode control for DFIG-based wind turbines fault ride-through capability enhancement.

    PubMed

    Benbouzid, Mohamed; Beltran, Brice; Amirat, Yassine; Yao, Gang; Han, Jingang; Mangel, Hervé

    2014-05-01

    This paper deals with the fault ride-through capability assessment of a doubly fed induction generator-based wind turbine using a high-order sliding mode control. Indeed, it has been recently suggested that sliding mode control is a solution of choice to the fault ride-through problem. In this context, this paper proposes a second-order sliding mode as an improved solution that handle the classical sliding mode chattering problem. Indeed, the main and attractive features of high-order sliding modes are robustness against external disturbances, the grids faults in particular, and chattering-free behavior (no extra mechanical stress on the wind turbine drive train). Simulations using the NREL FAST code on a 1.5-MW wind turbine are carried out to evaluate ride-through performance of the proposed high-order sliding mode control strategy in case of grid frequency variations and unbalanced voltage sags.

  9. Sliding-triboelectric nanogenerators based on in-plane charge-separation mechanism.

    PubMed

    Wang, Sihong; Lin, Long; Xie, Yannan; Jing, Qingshen; Niu, Simiao; Wang, Zhong Lin

    2013-05-08

    Aiming at harvesting ambient mechanical energy for self-powered systems, triboelectric nanogenerators (TENGs) have been recently developed as a highly efficient, cost-effective and robust approach to generate electricity from mechanical movements and vibrations on the basis of the coupling between triboelectrification and electrostatic induction. However, all of the previously demonstrated TENGs are based on vertical separation of triboelectric-charged planes, which requires sophisticated device structures to ensure enough resilience for the charge separation, otherwise there is no output current. In this paper, we demonstrated a newly designed TENG based on an in-plane charge separation process using the relative sliding between two contacting surfaces. Using Polyamide 6,6 (Nylon) and polytetrafluoroethylene (PTFE) films with surface etched nanowires, the two polymers at the opposite ends of the triboelectric series, the newly invented TENG produces an open-circuit voltage up to ~1300 V and a short-circuit current density of 4.1 mA/m(2) with a peak power density of 5.3 W/m(2), which can be used as a direct power source for instantaneously driving hundreds of serially connected light-emitting diodes (LEDs). The working principle and the relationships between electrical outputs and the sliding motion are fully elaborated and systematically studied, providing a new mode of TENGs with diverse applications. Compared to the existing vertical-touching based TENGs, this planar-sliding TENG has a high efficiency, easy fabrication, and suitability for many types of mechanical triggering. Furthermore, with the relationship between the electrical output and the sliding motion being calibrated, the sliding-based TENG could potentially be used as a self-powered displacement/speed/acceleration sensor.

  10. A DSP-based readout and online processing system for a new focal-plane polarimeter at AGOR

    NASA Astrophysics Data System (ADS)

    Hagemann, M.; Bassini, R.; van den Berg, A. M.; Ellinghaus, F.; Frekers, D.; Hannen, V. M.; Häupke, T.; Heyse, J.; Jacobs, E.; Kirsch, M.; Krüsemann, B.; Rakers, S.; Sohlbach, H.; Wörtche, H. J.

    1999-11-01

    A Focal-Plane Polarimeter (FPP) for the large acceptance Big-Bite Spectrometer (BBS) at AGOR using a novel readout architecture has been commissioned at the KVI Groningen. The instrument is optimized for medium-energy polarized proton scattering near or at 0°. For the handling of the high counting rates at extreme forward angles and for the suppression of small-angle scattering in the graphite analyzer, a high-performance data processing DSP system connecting to the LeCroy FERA and PCOS ECL bus architecture has been made operational and tested successfully. Details of the system and the functions of the various electronic components are described.

  11. RecutClub.com: An Open Source, Whole Slide Image-based Pathology Education System.

    PubMed

    Christensen, Paul A; Lee, Nathan E; Thrall, Michael J; Powell, Suzanne Z; Chevez-Barrios, Patricia; Long, S Wesley

    2017-01-01

    Our institution's pathology unknown conferences provide educational cases for our residents. However, the cases have not been previously available digitally, have not been collated for postconference review, and were not accessible to a wider audience. Our objective was to create an inexpensive whole slide image (WSI) education suite to address these limitations and improve the education of pathology trainees. We surveyed residents regarding their preference between four unique WSI systems. We then scanned weekly unknown conference cases and study set cases and uploaded them to our custom built WSI viewer located at RecutClub.com. We measured site utilization and conference participation. Residents preferred our OpenLayers WSI implementation to Ventana Virtuoso, Google Maps API, and OpenSlide. Over 16 months, we uploaded 1366 cases from 77 conferences and ten study sets, occupying 793.5 GB of cloud storage. Based on resident evaluations, the interface was easy to use and demonstrated minimal latency. Residents are able to review cases from home and from their mobile devices. Worldwide, 955 unique IP addresses from 52 countries have viewed cases in our site. We implemented a low-cost, publicly available repository of WSI slides for resident education. Our trainees are very satisfied with the freedom to preview either the glass slides or WSI and review the WSI postconference. Both local users and worldwide users actively and repeatedly view cases in our study set.

  12. RecutClub.com: An Open Source, Whole Slide Image-based Pathology Education System

    PubMed Central

    Christensen, Paul A.; Lee, Nathan E.; Thrall, Michael J.; Powell, Suzanne Z.; Chevez-Barrios, Patricia; Long, S. Wesley

    2017-01-01

    Background: Our institution's pathology unknown conferences provide educational cases for our residents. However, the cases have not been previously available digitally, have not been collated for postconference review, and were not accessible to a wider audience. Our objective was to create an inexpensive whole slide image (WSI) education suite to address these limitations and improve the education of pathology trainees. Materials and Methods: We surveyed residents regarding their preference between four unique WSI systems. We then scanned weekly unknown conference cases and study set cases and uploaded them to our custom built WSI viewer located at RecutClub.com. We measured site utilization and conference participation. Results: Residents preferred our OpenLayers WSI implementation to Ventana Virtuoso, Google Maps API, and OpenSlide. Over 16 months, we uploaded 1366 cases from 77 conferences and ten study sets, occupying 793.5 GB of cloud storage. Based on resident evaluations, the interface was easy to use and demonstrated minimal latency. Residents are able to review cases from home and from their mobile devices. Worldwide, 955 unique IP addresses from 52 countries have viewed cases in our site. Conclusions: We implemented a low-cost, publicly available repository of WSI slides for resident education. Our trainees are very satisfied with the freedom to preview either the glass slides or WSI and review the WSI postconference. Both local users and worldwide users actively and repeatedly view cases in our study set. PMID:28382224

  13. A real-time tracking system of infrared dim and small target based on FPGA and DSP

    NASA Astrophysics Data System (ADS)

    Rong, Sheng-hui; Zhou, Hui-xin; Qin, Han-lin; Wang, Bing-jian; Qian, Kun

    2014-11-01

    A core technology in the infrared warning system is the detection tracking of dim and small targets with complicated background. Consequently, running the detection algorithm on the hardware platform has highly practical value in the military field. In this paper, a real-time detection tracking system of infrared dim and small target which is used FPGA (Field Programmable Gate Array) and DSP (Digital Signal Processor) as the core was designed and the corresponding detection tracking algorithm and the signal flow is elaborated. At the first stage, the FPGA obtain the infrared image sequence from the sensor, then it suppresses background clutter by mathematical morphology method and enhances the target intensity by Laplacian of Gaussian operator. At the second stage, the DSP obtain both the original image and the filtered image form the FPGA via the video port. Then it segments the target from the filtered image by an adaptive threshold segmentation method and gets rid of false target by pipeline filter. Experimental results show that our system can achieve higher detection rate and lower false alarm rate.

  14. Implementation of Fast-ICA: A Performance Based Comparison Between Floating Point and Fixed Point DSP Platform

    NASA Astrophysics Data System (ADS)

    Patil, Dinesh; Das, Niva; Routray, Aurobinda

    2011-01-01

    The main focus of the paper is to bring out the differences in performance related issues of Fast-ICA algorithm associated with floating point and fixed point digital signal processing (DSP) platforms. The DSP platforms consisting of TMS320C6713 floating point processor and TMS320C6416 fixed point processor from Texas Instruments have been chosen for this purpose. To study the consistency of performance, the algorithm has been subjected to three different test cases comprising of a mixture of synthetic signals, a mixture of speech signals and a mixture of synthetic signals in presence of noise, respectively. The performance of the Fast-ICA algorithm on floating point and fixed point platform are compared on the basis of accuracy of separation and execution time. Experimental results show insignificant differences in the accuracy of separation and execution time obtained from fixed point processor when compared with those obtained from floating point processor. This clearly strengthens the feasibility issue concerning hardware realization of Fast-ICA on fixed point platform for specific applications.

  15. Experimental demonstration of a DSP-based cross-channel interference cancellation technique for application in digital filter multiple access PONs.

    PubMed

    Al-Rawachy, E; Giddings, R P; Tang, J M

    2017-02-20

    A DSP-based cross-channel interference cancellation (CCIC) technique with initial condition-free, fast convergence and signal modulation format independence, is experimentally demonstrated in a two-channel point-to-point digital filter multiple access (DFMA) PON system based on intensity-modulation and direct-detection (IMDD). The CCIC-induced transmission performance improvements under various system conditions are fully investigated for the first time. It is shown that with one iteration only the CCIC technique can achieve a reduction in individual OFDM subcarrier BERs of more than 1000 times, an increase in transmission capacity by as much as 19 times and an increase in optical power budget by as much as 3.5dB. The CCIC technique thus has the potential to drastically improve the transmission performance of DFMA PONs.

  16. Synthesis and characterization of lanthanide(III) (La, Gd, Yb, Y) disalicylidene-1,2-phenylenediamine (H{sub 2}dsp) Schiff-base complexes

    SciTech Connect

    Chen, Huiyong; Archer, R.D.

    1994-11-09

    Novel rare earth (III) disalicylidene-1,2-phenylenediamine(H{sub 2}dsp) complexes with the formula M[Ln(dsp){sub 2}] (M = Li, Na, K, Cs) were prepared. UV-visible absorption and NMR were used to study the disproportionation equilibrium for these complexes in DMSO. Structures for these complexes are suggested.

  17. Content-based histopathological image retrieval for whole slide image database using binary codes

    NASA Astrophysics Data System (ADS)

    Zheng, Yushan; Jiang, Zhiguo; Ma, Yibing; Zhang, Haopeng; Xie, Fengying; Shi, Huaqiang; Zhao, Yu

    2017-03-01

    Content-based image retrieval (CBIR) has been widely researched for medical images. In application of histo- pathological images, there are two issues that need to be carefully considered. The one is that the digital slide is stored in a spatially continuous image with a size of more than 10K x 10K pixels. The other is that the size of query image varies in a large range according to different diagnostic conditions. It is a challenging work to retrieve the eligible regions for the query image from the database that consists of whole slide images (WSIs). In this paper, we proposed a CBIR framework for the WSI database and size-scalable query images. Each WSI in the database is encoded and stored in a matrix of binary codes. When retrieving, the query image is first encoded into a set of binary codes and analyzed to pre-choose a set of regions from database using hashing method. Then a multi-binary-code-based similarity measurement based on hamming distance is designed to rank proposal regions. Finally, the top relevant regions and their locations in the WSIs along with the diagnostic information are returned to assist pathologists in diagnoses. The effectiveness of the proposed framework is evaluated in a fine-annotated WSIs database of epithelial breast tumors. The experimental results show that proposed framework is both effective and efficiency for content-based whole slide image retrieval.

  18. Terminal Sliding Mode-Based Consensus Tracking Control for Networked Uncertain Mechanical Systems on Digraphs.

    PubMed

    Chen, Gang; Song, Yongduan; Guan, Yanfeng

    2016-12-29

    This brief investigates the finite-time consensus tracking control problem for networked uncertain mechanical systems on digraphs. A new terminal sliding-mode-based cooperative control scheme is developed to guarantee that the tracking errors converge to an arbitrarily small bound around zero in finite time. All the networked systems can have different dynamics and all the dynamics are unknown. A neural network is used at each node to approximate the local unknown dynamics. The control schemes are implemented in a fully distributed manner. The proposed control method eliminates some limitations in the existing terminal sliding-mode-based consensus control methods and extends the existing analysis methods to the case of directed graphs. Simulation results on networked robot manipulators are provided to show the effectiveness of the proposed control algorithms.

  19. Extended observer based on adaptive second order sliding mode control for a fixed wing UAV.

    PubMed

    Castañeda, Herman; Salas-Peña, Oscar S; León-Morales, Jesús de

    2017-01-01

    This paper addresses the design of attitude and airspeed controllers for a fixed wing unmanned aerial vehicle. An adaptive second order sliding mode control is proposed for improving performance under different operating conditions and is robust in presence of external disturbances. Moreover, this control does not require the knowledge of disturbance bounds and avoids overestimation of the control gains. Furthermore, in order to implement this controller, an extended observer is designed to estimate unmeasurable states as well as external disturbances. Additionally, sufficient conditions are given to guarantee the closed-loop stability of the observer based control. Finally, using a full 6 degree of freedom model, simulation results are obtained where the performance of the proposed method is compared against active disturbance rejection based on sliding mode control.

  20. An artificial muscle model unit based on inorganic nanosheet sliding by photochemical reaction.

    PubMed

    Nabetani, Yu; Takamura, Hazuki; Hayasaka, Yuika; Sasamoto, Shin; Tanamura, Yoshihiko; Shimada, Tetsuya; Masui, Dai; Takagi, Shinsuke; Tachibana, Hiroshi; Tong, Zhiwei; Inoue, Haruo

    2013-04-21

    From the viewpoint of developing photoresponsive supramolecular systems in microenvironments to exhibit more sophisticated photo-functions even at the macroscopic level, inorganic/organic hybrid compounds based on clay or niobate nanosheets as the microenvironments were prepared, characterized, and examined for their photoreactions. We show here a novel type of artificial muscle model unit having much similarity with that in natural muscle fibrils. Upon photoirradiation, the organic/inorganic hybrid nanosheets reversibly slide horizontally on a giant scale, and the interlayer spaces in the layered hybrid structure shrink and expand vertically. In particular, our layered hybrid molecular system exhibits a macroscopic morphological change on a giant scale (~1500 nm) compared with the molecular size of ~1 nm, based on a reversible sliding mechanism.

  1. Classical low-pass filter and real-time wavelet-based denoising technique implemented on a DSP: a comparison study

    NASA Astrophysics Data System (ADS)

    Dolabdjian, Ch.; Fadili, J.; Huertas Leyva, E.

    2002-11-01

    We have implemented a real-time numerical denoising algorithm, using the Discrete Wavelet Transform (DWT), on a TMS320C3x Digital Signal Processor (DSP). We also compared from a theoretical and practical viewpoints this post-processing approach to a more classical low-pass filter. This comparison was carried out using an ECG-type signal (ElectroCardiogram). The denoising approach is an elegant and extremely fast alternative to the classical linear filters class. It is particularly adapted to non-stationary signals such as those encountered in biological applications. The denoising allows to substantially improve detection of such signals over Fourier-based techniques. This processing step is a vital element in our acquisition chain using high sensitivity magnetic sensors. It should enhance detection of cardiac-type magnetic signals or magnetic particles in movement.

  2. Adaptive sliding mode controller based on super-twist observer for tethered satellite system

    NASA Astrophysics Data System (ADS)

    Keshtkar, Sajjad; Poznyak, Alexander

    2016-09-01

    In this work, the sliding mode control based on the super-twist observer is presented. The parameters of the controller as well as the observer are admitted to be time-varying and depending on available current measurements. In view of that, the considered controller is referred to as an adaptive one. It is shown that the deviations of the generated state estimates from real state values together with a distance of the closed-loop system trajectories to a desired sliding surface reach a μ-zone around the origin in finite time. The application of the suggested controller is illustrated for the orientation of a tethered satellite system in a required position.

  3. Implementation of fuzzy-sliding mode based control of a grid connected photovoltaic system.

    PubMed

    Menadi, Abdelkrim; Abdeddaim, Sabrina; Ghamri, Ahmed; Betka, Achour

    2015-09-01

    The present work describes an optimal operation of a small scale photovoltaic system connected to a micro-grid, based on both sliding mode and fuzzy logic control. Real time implementation is done through a dSPACE 1104 single board, controlling a boost chopper on the PV array side and a voltage source inverter (VSI) on the grid side. The sliding mode controller tracks permanently the maximum power of the PV array regardless of atmospheric condition variations, while The fuzzy logic controller (FLC) regulates the DC-link voltage, and ensures via current control of the VSI a quasi-total transit of the extracted PV power to the grid under a unity power factor operation. Simulation results, carried out via Matlab-Simulink package were approved through experiment, showing the effectiveness of the proposed control techniques. Copyright © 2015. Published by Elsevier Ltd.

  4. Biomolecular implementation of a quasi sliding mode feedback controller based on DNA strand displacement reactions.

    PubMed

    Sawlekar, Rucha; Montefusco, Francesco; Kulkarni, Vishwesh; Bates, Declan G

    2015-08-01

    A fundamental aim of synthetic biology is to achieve the capability to design and implement robust embedded biomolecular feedback control circuits. An approach to realize this objective is to use abstract chemical reaction networks (CRNs) as a programming language for the design of complex circuits and networks. Here, we employ this approach to facilitate the implementation of a class of nonlinear feedback controllers based on sliding mode control theory. We show how a set of two-step irreversible reactions with ultrasensitive response dynamics can provide a biomolecular implementation of a nonlinear quasi sliding mode (QSM) controller. We implement our controller in closed-loop with a prototype of a biological pathway and demonstrate that the nonlinear QSM controller outperforms a traditional linear controller by facilitating faster tracking response dynamics without introducing overshoots in the transient response.

  5. Functional Based Adaptive and Fuzzy Sliding Controller for Non-Autonomous Active Suspension System

    NASA Astrophysics Data System (ADS)

    Huang, Shiuh-Jer; Chen, Hung-Yi

    In this paper, an adaptive sliding controller is developed for controlling a vehicle active suspension system. The functional approximation technique is employed to substitute the unknown non-autonomous functions of the suspension system and release the model-based requirement of sliding mode control algorithm. In order to improve the control performance and reduce the implementation problem, a fuzzy strategy with online learning ability is added to compensate the functional approximation error. The update laws of the functional approximation coefficients and the fuzzy tuning parameters are derived from the Lyapunov theorem to guarantee the system stability. The proposed controller is implemented on a quarter-car hydraulic actuating active suspension system test-rig. The experimental results show that the proposed controller suppresses the oscillation amplitude of the suspension system effectively.

  6. Current Sensor Fault Diagnosis Based on a Sliding Mode Observer for PMSM Driven Systems.

    PubMed

    Huang, Gang; Luo, Yi-Ping; Zhang, Chang-Fan; Huang, Yi-Shan; Zhao, Kai-Hui

    2015-05-11

    This paper proposes a current sensor fault detection method based on a sliding mode observer for the torque closed-loop control system of interior permanent magnet synchronous motors. First, a sliding mode observer based on the extended flux linkage is built to simplify the motor model, which effectively eliminates the phenomenon of salient poles and the dependence on the direct axis inductance parameter, and can also be used for real-time calculation of feedback torque. Then a sliding mode current observer is constructed in αβ coordinates to generate the fault residuals of the phase current sensors. The method can accurately identify abrupt gain faults and slow-variation offset faults in real time in faulty sensors, and the generated residuals of the designed fault detection system are not affected by the unknown input, the structure of the observer, and the theoretical derivation and the stability proof process are concise and simple. The RT-LAB real-time simulation is used to build a simulation model of the hardware in the loop. The simulation and experimental results demonstrate the feasibility and effectiveness of the proposed method.

  7. Sliding mode disturbance observer-based adaptive integral backstepping control of a piezoelectric nano-manipulator

    NASA Astrophysics Data System (ADS)

    Zhang, Yangming; Yan, Peng

    2016-12-01

    This paper investigates a systematic modeling and control methodology for a multi-axis PZT (piezoelectric transducer) actuated servo stage supporting nano-manipulations. A sliding mode disturbance observer-based adaptive integral backstepping control method with an estimated inverse model compensation scheme is proposed to achieve ultra high precision tracking in the presence of the hysteresis nonlinearities, model uncertainties, and external disturbances. By introducing a time rate of the input signal, an enhanced rate-dependent Prandtl-Ishlinskii model is developed to describe the hysteresis behaviors, and its inverse is also constructed to mitigate their adverse effects. In particular, the corresponding inverse compensation error is analyzed and its boundedness is proven. Subsequently, the sliding mode disturbance observer-based adaptive integral backstepping controller is designed to guarantee the convergence of the tracking error, where the sliding mode disturbance observer can track the total disturbances in a finite time, while the integral action is incorporated into the adaptive backstepping design to improve the steady-state control accuracy. Finally, real time implementations of the proposed algorithm are applied on the PZT actuated servo system, where excellent tracking performance with tracking precision error around 6‰ for circular contour tracking is achieved in the experimental results.

  8. Current Sensor Fault Diagnosis Based on a Sliding Mode Observer for PMSM Driven Systems

    PubMed Central

    Huang, Gang; Luo, Yi-Ping; Zhang, Chang-Fan; Huang, Yi-Shan; Zhao, Kai-Hui

    2015-01-01

    This paper proposes a current sensor fault detection method based on a sliding mode observer for the torque closed-loop control system of interior permanent magnet synchronous motors. First, a sliding mode observer based on the extended flux linkage is built to simplify the motor model, which effectively eliminates the phenomenon of salient poles and the dependence on the direct axis inductance parameter, and can also be used for real-time calculation of feedback torque. Then a sliding mode current observer is constructed in αβ coordinates to generate the fault residuals of the phase current sensors. The method can accurately identify abrupt gain faults and slow-variation offset faults in real time in faulty sensors, and the generated residuals of the designed fault detection system are not affected by the unknown input, the structure of the observer, and the theoretical derivation and the stability proof process are concise and simple. The RT-LAB real-time simulation is used to build a simulation model of the hardware in the loop. The simulation and experimental results demonstrate the feasibility and effectiveness of the proposed method. PMID:25970258

  9. Process-Based Characterizations of Subsurface Fluid Pressures for a Devil's Slide-like System

    NASA Astrophysics Data System (ADS)

    Thomas, M.; Loague, K.

    2014-12-01

    Coastal margins commonly host slope stability hazards that are influenced by hydrologic, geologic, and / or anthropogenic perturbations. A firm foundation for rigorously understanding the component contributions and process-based linkages among hydrologic and geomorphic response is comprehensive physics-based simulation. This study is motivated by the hydrologically-driven, creeping and episodic deep-seated bedrock slides that intersect a former section of the Pacific Coast Highway in the active landslide zone at Devil's Slide near Pacifica, California. For this study, deterministic-conceptual hydrogeologic simulation was employed to estimate fluid pressures for saturated three-dimensional (3D) subsurface systems. One-dimensional (1D) vertical, transient, variably-saturated simulations were conducted to establish the position of the water table (i.e., the upper boundary condition) for the 3D steady-state saturated problems which encode the geologic information for heterogeneous and anisotropic systems. The concept-development effort undertaken here demonstrates that, for a Devil's Slide-like system: (i) specific climatic conditions facilitate variable lag times associated with water-table dynamics, (ii) recharge is the most sensitive parameter to establish risk-averse estimates of fluid pressure, (iii) nuances in the 3D flow field related to fault zone characteristics markedly influence fluid pressures, and (iv) it is unlikely that seasonal fluctuations in the regional water table account for severe failure modes. The simulated fluid pressures encourage new interdisciplinary data discovery to investigate the spatial and temporal persistence of perched water in the study area. To capture event-driven failures for the Devil's Slide site, future efforts should develop characterizations of the unsaturated near surface with a rigor similar to the treatment of the saturated zone demonstrated by this study.

  10. Time-scaling based sliding mode control for Neuromuscular Electrical Stimulation under uncertain relative degrees.

    PubMed

    Oliveira, Tiago Roux; Costa, Luiz Rennó; Catunda, João Marcos Yamasaki; Pino, Alexandre Visintainer; Barbosa, William; Souza, Márcio Nogueira de

    2017-06-01

    This paper addresses the application of the sliding mode approach to control the arm movements by artificial recruitment of muscles using Neuromuscular Electrical Stimulation (NMES). Such a technique allows the activation of motor nerves using surface electrodes. The goal of the proposed control system is to move the upper limbs of subjects through electrical stimulation to achieve a desired elbow angular displacement. Since the human neuro-motor system has individual characteristics, being time-varying, nonlinear and subject to uncertainties, the use of advanced robust control schemes may represent a better solution than classical Proportional-Integral (PI) controllers and model-based approaches, being simpler than more sophisticated strategies using fuzzy logic or neural networks usually applied in this control problem. The objective is the introduction of a new time-scaling base sliding mode control (SMC) strategy for NMES and its experimental evaluation. The main qualitative advantages of the proposed controller via time-scaling procedure are its independence of the knowledge of the plant relative degree and the design/tuning simplicity. The developed sliding mode strategy allows for chattering alleviation due to the impact of the integrator in smoothing the control signal. In addition, no differentiator is applied to construct the sliding surface. The stability analysis of the closed-loop system is also carried out by using singular perturbation methods. Experimental results are conducted with healthy volunteers as well as stroke patients. Quantitative results show a reduction of 45% in terms of root mean square (RMS) error (from 5.9° to [Formula: see text] ) in comparison with PI control scheme, which is similar to that obtained in the literature. Copyright © 2017 IPEM. Published by Elsevier Ltd. All rights reserved.

  11. Adaptive Actor-Critic Design-Based Integral Sliding-Mode Control for Partially Unknown Nonlinear Systems With Input Disturbances.

    PubMed

    Fan, Quan-Yong; Yang, Guang-Hong

    2016-01-01

    This paper is concerned with the problem of integral sliding-mode control for a class of nonlinear systems with input disturbances and unknown nonlinear terms through the adaptive actor-critic (AC) control method. The main objective is to design a sliding-mode control methodology based on the adaptive dynamic programming (ADP) method, so that the closed-loop system with time-varying disturbances is stable and the nearly optimal performance of the sliding-mode dynamics can be guaranteed. In the first step, a neural network (NN)-based observer and a disturbance observer are designed to approximate the unknown nonlinear terms and estimate the input disturbances, respectively. Based on the NN approximations and disturbance estimations, the discontinuous part of the sliding-mode control is constructed to eliminate the effect of the disturbances and attain the expected equivalent sliding-mode dynamics. Then, the ADP method with AC structure is presented to learn the optimal control for the sliding-mode dynamics online. Reconstructed tuning laws are developed to guarantee the stability of the sliding-mode dynamics and the convergence of the weights of critic and actor NNs. Finally, the simulation results are presented to illustrate the effectiveness of the proposed method.

  12. Robust current control-based generalized predictive control with sliding mode disturbance compensation for PMSM drives.

    PubMed

    Liu, Xudong; Zhang, Chenghui; Li, Ke; Zhang, Qi

    2017-09-06

    This paper addresses the current control of permanent magnet synchronous motor (PMSM) for electric drives with model uncertainties and disturbances. A generalized predictive current control method combined with sliding mode disturbance compensation is proposed to satisfy the requirement of fast response and strong robustness. Firstly, according to the generalized predictive control (GPC) theory based on the continuous time model, a predictive current control method is presented without considering the disturbance, which is convenient to be realized in the digital controller. In fact, it's difficult to derive the exact motor model and parameters in the practical system. Thus, a sliding mode disturbance compensation controller is studied to improve the adaptiveness and robustness of the control system. The designed controller attempts to combine the merits of both predictive control and sliding mode control, meanwhile, the controller parameters are easy to be adjusted. Lastly, the proposed controller is tested on an interior PMSM by simulation and experiment, and the results indicate that it has good performance in both current tracking and disturbance rejection. Copyright © 2017 ISA. Published by Elsevier Ltd. All rights reserved.

  13. Drag-based composite super-twisting sliding mode control law design for Mars entry guidance

    NASA Astrophysics Data System (ADS)

    Zhao, Zhenhua; Yang, Jun; Li, Shihua; Guo, Lei

    2016-06-01

    In this paper, the drag-based trajectory tracking guidance problem is investigated for Mars entry vehicle subject to uncertainties. A composite super twisting sliding mode control method based on finite-time disturbance observer is proposed for guidance law design. The proposed controller not only eliminates the effects of matched and mismatched disturbances due to uncertainties of atmospheric models and vehicle aerodynamics but also guarantees the continuity of control action. Numerical simulations are carried out on the basis of Mars Science Laboratory mission, where the results show that the proposed methods can improve the Mars entry guidance precision as compared with some existing guidance methods including PID and ADRC.

  14. Synchronizing chaotic dynamics with uncertainties based on a sliding mode control design.

    PubMed

    Yang, Tao; Shao, Hui He

    2002-04-01

    The synchronization of two chaotic systems with uncertainties is studied in this paper. A feedback controller is provided based on a sliding mode control design. A kind of extended state observer is used to compensate for the systems' uncertainties, such as the structure difference or parameter mismatching, using only the available synchronizing error. Then the feedback controller becomes physically realizable based on the states of the observer, and can be used to synchronize two continuous chaotic systems. Illustrative examples of the synchronization of Duffing and Van der Pol oscillators as well as two Lorenz systems with parameter mismatching are proposed to show the effectiveness of this method.

  15. GLACIER SLIDING,

    DTIC Science & Technology

    The theory of the sliding of glaciers presented in earlier papers has been generalized (1) by taking into account the resistance to sliding offered...bed at the downstream side of an obstacle. The sliding velocities and controlling obstacle sizes which are found from the generalized theory are...magnitude smaller in thickness than the height of the controlling obstacles can cause an appreciable increase in the sliding velocity. The generalized

  16. DSP: a protein shape string and its profile prediction server

    PubMed Central

    Sun, Jiangming; Tang, Shengnan; Xiong, Wenwei; Cong, Peisheng; Li, Tonghua

    2012-01-01

    Many studies have demonstrated that shape string is an extremely important structure representation, since it is more complete than the classical secondary structure. The shape string provides detailed information also in the regions denoted random coil. But few services are provided for systematic analysis of protein shape string. To fill this gap, we have developed an accurate shape string predictor based on two innovative technologies: a knowledge-driven sequence alignment and a sequence shape string profile method. The performance on blind test data demonstrates that the proposed method can be used for accurate prediction of protein shape string. The DSP server provides both predicted shape string and sequence shape string profile for each query sequence. Using this information, the users can compare protein structure or display protein evolution in shape string space. The DSP server is available at both http://cheminfo.tongji.edu.cn/dsp/ and its main mirror http://chemcenter.tongji.edu.cn/dsp/. PMID:22553364

  17. DSP: a protein shape string and its profile prediction server.

    PubMed

    Sun, Jiangming; Tang, Shengnan; Xiong, Wenwei; Cong, Peisheng; Li, Tonghua

    2012-07-01

    Many studies have demonstrated that shape string is an extremely important structure representation, since it is more complete than the classical secondary structure. The shape string provides detailed information also in the regions denoted random coil. But few services are provided for systematic analysis of protein shape string. To fill this gap, we have developed an accurate shape string predictor based on two innovative technologies: a knowledge-driven sequence alignment and a sequence shape string profile method. The performance on blind test data demonstrates that the proposed method can be used for accurate prediction of protein shape string. The DSP server provides both predicted shape string and sequence shape string profile for each query sequence. Using this information, the users can compare protein structure or display protein evolution in shape string space. The DSP server is available at both http://cheminfo.tongji.edu.cn/dsp/ and its main mirror http://chemcenter.tongji.edu.cn/dsp/.

  18. Smart Altera firmware for DSP with FPGAs

    NASA Astrophysics Data System (ADS)

    Meyer-Baese, Uwe; Vera, A.; Meyer-Baese, A.; Pattichis, M.; Perry, R.

    2007-04-01

    Design of current DSP applications using state-of-the art multi-million gates devices requires a broad foundation of engineering skills ranging from knowledge of hardware-efficient DSP algorithms to CAD design tools. The requirement of short time-to-market, however, requires to replace the traditional HDL based designs by a MatLab/Simulink-based design flow. This not only allows the over 1 million MatLab users to design with FPGAs but also to by-pass the hardware design engineer and leads therefore to shorter development time. We have evaluated the Altera/Simulink tool flow used for a University design environment and present design experience of a semester course at FAMU-FSU College of Engineering. We discuss the required background knowledge, key target smart firmware for FPGAs and possible advanced designs, e.g. FFT and multirate filter banks and wavelets designed by students with only basic logic experience.

  19. Innovative use of DSP technology in space: FORTE event classifier

    SciTech Connect

    Briles, S.; Moore, K. Jones, R.; Klingner, P.; Neagley, D.; Caffrey, M.; Henneke, K.; Spurgen, W.; Blain, P.

    1994-08-01

    The Fast On-Orbit Recording of Transient Events (FORTE) small satellite will field a digital signal processor (DSP) experiment for the purpose of classifying radio-frequency (rf) transient signals propagating through the earth`s ionosphere. Designated the Event Classifier experiment, this DSP experiment uses a single Texas Instruments` SMJ320C30 DSP to execute preprocessing, feature extraction, and classification algorithms on down-converted, digitized, and buffered rf transient signals in the frequency range of 30 to 300 MHz. A radiation-hardened microcontroller monitors DSP- abnormalities and supervises spacecraft command communications. On- orbit evaluation of multiple algorithms is supported by the Event Classifier architecture. Ground-based commands determine the subset and sequence of algorithms executed to classify a captured time series. Conventional neural network classification algorithms will be some of the classification techniques implemented on-board FORTE while in a low-earth orbit. Results of all experiments, after being stored in DSP flash memory, will be transmitted through the spacecraft to ground stations. The Event Classifier is a versatile and fault-tolerant experiment that is an important new space-based application of DSP technology.

  20. Trajectory tracking control of omnidirectional wheeled mobile manipulators: robust neural network-based sliding mode approach.

    PubMed

    Xu, Dong; Zhao, Dongbin; Yi, Jianqiang; Tan, Xiangmin

    2009-06-01

    This paper addresses the robust trajectory tracking problem for a redundantly actuated omnidirectional mobile manipulator in the presence of uncertainties and disturbances. The development of control algorithms is based on sliding mode control (SMC) technique. First, a dynamic model is derived based on the practical omnidirectional mobile manipulator system. Then, a SMC scheme, based on the fixed large upper boundedness of the system dynamics (FLUBSMC), is designed to ensure trajectory tracking of the closed-loop system. However, the FLUBSMC scheme has inherent deficiency, which needs computing the upper boundedness of the system dynamics, and may cause high noise amplification and high control cost, particularly for the complex dynamics of the omnidirectional mobile manipulator system. Therefore, a robust neural network (NN)-based sliding mode controller (NNSMC), which uses an NN to identify the unstructured system dynamics directly, is further proposed to overcome the disadvantages of FLUBSMC and reduce the online computing burden of conventional NN adaptive controllers. Using learning ability of NN, NNSMC can coordinately control the omnidirectional mobile platform and the mounted manipulator with different dynamics effectively. The stability of the closed-loop system, the convergence of the NN weight-updating process, and the boundedness of the NN weight estimation errors are all strictly guaranteed. Then, in order to accelerate the NN learning efficiency, a partitioned NN structure is applied. Finally, simulation examples are given to demonstrate the proposed NNSMC approach can guarantee the whole system's convergence to the desired manifold with prescribed performance.

  1. Evaluation of Solid Supports for Slide- and Well-Based Recombinant Antibody Microarrays.

    PubMed

    Gerdtsson, Anna S; Dexlin-Mellby, Linda; Delfani, Payam; Berglund, Erica; Borrebaeck, Carl A K; Wingren, Christer

    2016-06-08

    Antibody microarrays have emerged as an important tool within proteomics, enabling multiplexed protein expression profiling in both health and disease. The design and performance of antibody microarrays and how they are processed are dependent on several factors, of which the interplay between the antibodies and the solid surfaces plays a central role. In this study, we have taken on the first comprehensive view and evaluated the overall impact of solid surfaces on the recombinant antibody microarray design. The results clearly demonstrated the importance of the surface-antibody interaction and showed the effect of the solid supports on the printing process, the array format of planar arrays (slide- and well-based), the assay performance (spot features, reproducibility, specificity and sensitivity) and assay processing (degree of automation). In the end, two high-end recombinant antibody microarray technology platforms were designed, based on slide-based (black polymer) and well-based (clear polymer) arrays, paving the way for future large-scale protein expression profiling efforts.

  2. Two modified discrete PID-based sliding mode controllers for piezoelectric actuators

    NASA Astrophysics Data System (ADS)

    Cao, Y.; Chen, X. B.

    2014-01-01

    Hysteresis is a nonlinear effect that can result in the degraded performance of piezoelectric actuators (PEAs). To counteract the effect, several control methods have been developed and reported in the literature. One promising method for compensation is the use of a proportional-integral-derivative (PID)-based sliding mode control (SMC), in which the PEA hysteresis is treated as an unknown disturbance to the PEA input. If the hysteresis can be modelled or partially modelled, the integration of the hysteresis models into the control schemes may lead to further improved performance. On this philosophy, this paper presents the development of two modified discrete PID-based sliding mode controllers (PID-SMCs) for the PEAs, namely an inversion-based PID-SMC and a disturbance-observer (DOB)-based PID-SMC, in which the PEA hysteresis is predicted or partially predicted through the use of existing models for the PEA hysteresis. Experiments were performed to verify the effectiveness of the proposed control schemes. The results were compared to those of the nominal PID-SMC. By employing the inversion hysteresis and the DOB, the PEA performance was greatly improved.

  3. Evaluation of Solid Supports for Slide- and Well-Based Recombinant Antibody Microarrays

    PubMed Central

    Gerdtsson, Anna S.; Dexlin-Mellby, Linda; Delfani, Payam; Berglund, Erica; Borrebaeck, Carl A. K.; Wingren, Christer

    2016-01-01

    Antibody microarrays have emerged as an important tool within proteomics, enabling multiplexed protein expression profiling in both health and disease. The design and performance of antibody microarrays and how they are processed are dependent on several factors, of which the interplay between the antibodies and the solid surfaces plays a central role. In this study, we have taken on the first comprehensive view and evaluated the overall impact of solid surfaces on the recombinant antibody microarray design. The results clearly demonstrated the importance of the surface-antibody interaction and showed the effect of the solid supports on the printing process, the array format of planar arrays (slide- and well-based), the assay performance (spot features, reproducibility, specificity and sensitivity) and assay processing (degree of automation). In the end, two high-end recombinant antibody microarray technology platforms were designed, based on slide-based (black polymer) and well-based (clear polymer) arrays, paving the way for future large-scale protein expression profiling efforts. PMID:27600082

  4. DSP Technology and Methods for OCT

    NASA Astrophysics Data System (ADS)

    Ali, Murtaza; Ahmad, Adeel; Boppart, Stephen A.

    Medical imaging devices are continually changing and evolving. In recent years, these devices have been evolving towards portable and handheld point-of-care systems. Innovations in the semiconductor technologies have been a major driving factor for such evolution. Today, optical coherence tomography (OCT) systems are mostly cart-based or desktop systems. Portable and hand-held OCT systems will open up new opportunities for their use. Recent advances in optics and scanning techniques have led to miniaturization of the optics used to acquire the raw data and at the same time, allow very high data acquisition rate. The signal processing chain to convert this raw acquired data into useful structural images is computationally intensive. The semiconductor industry, however, has a class of embedded processor technologies, known as digital signal processors (DSP), designed to take on such computations with very low power and size. DSP technology is a crucial enabler to create low power, low cost, handheld and portable OCT systems.

  5. Controlling chaos based on a novel intelligent integral terminal sliding mode control in a rod-type plasma torch

    NASA Astrophysics Data System (ADS)

    Safa, Khari; Zahra, Rahmani; Behrooz, Rezaie

    2016-05-01

    An integral terminal sliding mode controller is proposed in order to control chaos in a rod-type plasma torch system. In this method, a new sliding surface is defined based on a combination of the conventional sliding surface in terminal sliding mode control and a nonlinear function of the integral of the system states. It is assumed that the dynamics of a chaotic system are unknown and also the system is exposed to disturbance and unstructured uncertainty. To achieve a chattering-free and high-speed response for such an unknown system, an adaptive neuro-fuzzy inference system is utilized in the next step to approximate the unknown part of the nonlinear dynamics. Then, the proposed integral terminal sliding mode controller stabilizes the approximated system based on Lyapunov’s stability theory. In addition, a Bee algorithm is used to select the coefficients of integral terminal sliding mode controller to improve the performance of the proposed method. Simulation results demonstrate the improvement in the response speed, chattering rejection, transient response, and robustness against uncertainties.

  6. RandomSpot: A web-based tool for systematic random sampling of virtual slides.

    PubMed

    Wright, Alexander I; Grabsch, Heike I; Treanor, Darren E

    2015-01-01

    This paper describes work presented at the Nordic Symposium on Digital Pathology 2014, Linköping, Sweden. Systematic random sampling (SRS) is a stereological tool, which provides a framework to quickly build an accurate estimation of the distribution of objects or classes within an image, whilst minimizing the number of observations required. RandomSpot is a web-based tool for SRS in stereology, which systematically places equidistant points within a given region of interest on a virtual slide. Each point can then be visually inspected by a pathologist in order to generate an unbiased sample of the distribution of classes within the tissue. Further measurements can then be derived from the distribution, such as the ratio of tumor to stroma. RandomSpot replicates the fundamental principle of traditional light microscope grid-shaped graticules, with the added benefits associated with virtual slides, such as facilitated collaboration and automated navigation between points. Once the sample points have been added to the region(s) of interest, users can download the annotations and view them locally using their virtual slide viewing software. Since its introduction, RandomSpot has been used extensively for international collaborative projects, clinical trials and independent research projects. So far, the system has been used to generate over 21,000 sample sets, and has been used to generate data for use in multiple publications, identifying significant new prognostic markers in colorectal, upper gastro-intestinal and breast cancer. Data generated using RandomSpot also has significant value for training image analysis algorithms using sample point coordinates and pathologist classifications.

  7. A sliding mode-based starling-like controller for implantable rotary blood pumps.

    PubMed

    Bakouri, Mohsen A; Salamonsen, Robert F; Savkin, Andrey V; AlOmari, Abdul-Hakeem H; Lim, Einly; Lovell, Nigel H

    2014-07-01

    Clinically adequate implementation of physiological control of a rotary left ventricular assist device requires a sophisticated technique such as the recently proposed method based on the Frank-Starling mechanism. In this mechanism, the stroke volume of the heart increases in response to an increase in the volume of blood filling the left ventricle at the end of diastole. To emulate this process, changes in pump speed need to automatically regulate pump flow to ensure that the combined output of the left ventricle and pump match the output of the right ventricle across changing cardiovascular states. In this approach, we exploit the linear relationship between estimated mean pump flow (Q ̅ est) and pump flow pulsatility (PIQp) in a tracking control algorithm based on sliding mode control. The immediate response of the controller was assessed using a lumped parameter model of the cardiovascular system (CVS) and pump from which could be extracted both Q ̅ est and PIQp. Two different perturbations from the resting state in the presence of left ventricular failure were tested. The first was blood loss requiring a reduction in pump flow to match the reduced output from the right ventricle and to avoid the complication of ventricular suction. The second was exercise, requiring an increase in pump flow. The sliding mode controller induced the required changes in Qp within approximately five heart beats in the blood loss simulation and eight heart beats in the exercise simulation without clinically significant transients or steady-state errors.

  8. Sliding mode based trajectory linearization control for hypersonic reentry vehicle via extended disturbance observer.

    PubMed

    Xingling, Shao; Honglun, Wang

    2014-11-01

    This paper proposes a novel hybrid control framework by combing observer-based sliding mode control (SMC) with trajectory linearization control (TLC) for hypersonic reentry vehicle (HRV) attitude tracking problem. First, fewer control consumption is achieved using nonlinear tracking differentiator (TD) in the attitude loop. Second, a novel SMC that employs extended disturbance observer (EDO) to counteract the effect of uncertainties using a new sliding surface which includes the estimation error is integrated to address the tracking error stabilization issues in the attitude and angular rate loop, respectively. In addition, new results associated with EDO are examined in terms of dynamic response and noise-tolerant performance, as well as estimation accuracy. The key feature of the proposed compound control approach is that chattering free tracking performance with high accuracy can be ensured for HRV in the presence of multiple uncertainties under control constraints. Based on finite time convergence stability theory, the stability of the resulting closed-loop system is well established. Also, comparisons and extensive simulation results are presented to demonstrate the effectiveness of the control strategy.

  9. Adaptive stochastic resonance method for impact signal detection based on sliding window

    NASA Astrophysics Data System (ADS)

    Li, Jimeng; Chen, Xuefeng; He, Zhengjia

    2013-04-01

    Aiming at solving the existing sharp problems in impact signal detection by using stochastic resonance (SR) in the fault diagnosis of rotating machinery, such as the measurement index selection of SR and the detection of impact signal with different impact amplitudes, the present study proposes an adaptive SR method for impact signal detection based on sliding window by analyzing the SR characteristics of impact signal. This method can not only achieve the optimal selection of system parameters by means of weighted kurtosis index constructed through using kurtosis index and correlation coefficient, but also achieve the detection of weak impact signal through the algorithm of data segmentation based on sliding window, even though the differences between different impact amplitudes are great. The algorithm flow of adaptive SR method is given and effectiveness of the method has been verified by the contrastive results between the proposed method and the traditional SR method of simulation experiments. Finally, the proposed method has been applied to a gearbox fault diagnosis in a hot strip finishing mill in which two local faults located on the pinion are obtained successfully. Therefore, it can be concluded that the proposed method is of great practical value in engineering.

  10. Robust In-Flight Sensor Fault Diagnostics for Aircraft Engine Based on Sliding Mode Observers

    PubMed Central

    Chang, Xiaodong; Huang, Jinquan; Lu, Feng

    2017-01-01

    For a sensor fault diagnostic system of aircraft engines, the health performance degradation is an inevitable interference that cannot be neglected. To address this issue, this paper investigates an integrated on-line sensor fault diagnostic scheme for a commercial aircraft engine based on a sliding mode observer (SMO). In this approach, one sliding mode observer is designed for engine health performance tracking, and another for sensor fault reconstruction. Both observers are employed in in-flight applications. The results of the former SMO are analyzed for post-flight updating the baseline model of the latter. This idea is practical and feasible since the updating process does not require the algorithm to be regulated or redesigned, so that ground-based intervention is avoided, and the update process is implemented in an economical and efficient way. With this setup, the robustness of the proposed scheme to the health degradation is much enhanced and the latter SMO is able to fulfill sensor fault reconstruction over the course of the engine life. The proposed sensor fault diagnostic system is applied to a nonlinear simulation of a commercial aircraft engine, and its effectiveness is evaluated in several fault scenarios. PMID:28398255

  11. Robust In-Flight Sensor Fault Diagnostics for Aircraft Engine Based on Sliding Mode Observers.

    PubMed

    Chang, Xiaodong; Huang, Jinquan; Lu, Feng

    2017-04-11

    For a sensor fault diagnostic system of aircraft engines, the health performance degradation is an inevitable interference that cannot be neglected. To address this issue, this paper investigates an integrated on-line sensor fault diagnostic scheme for a commercial aircraft engine based on a sliding mode observer (SMO). In this approach, one sliding mode observer is designed for engine health performance tracking, and another for sensor fault reconstruction. Both observers are employed in in-flight applications. The results of the former SMO are analyzed for post-flight updating the baseline model of the latter. This idea is practical and feasible since the updating process does not require the algorithm to be regulated or redesigned, so that ground-based intervention is avoided, and the update process is implemented in an economical and efficient way. With this setup, the robustness of the proposed scheme to the health degradation is much enhanced and the latter SMO is able to fulfill sensor fault reconstruction over the course of the engine life. The proposed sensor fault diagnostic system is applied to a nonlinear simulation of a commercial aircraft engine, and its effectiveness is evaluated in several fault scenarios.

  12. An Efficient Algorithm for Sliding Window-Based Weighted Frequent Pattern Mining over Data Streams

    NASA Astrophysics Data System (ADS)

    Ahmed, Chowdhury Farhan; Tanbeer, Syed Khairuzzaman; Jeong, Byeong-Soo; Lee, Young-Koo

    Traditional frequent pattern mining algorithms do not consider different semantic significances (weights) of the items. By considering different weights of the items, weighted frequent pattern (WFP) mining becomes an important research issue in data mining and knowledge discovery area. However, the existing state-of-the-art WFP mining algorithms consider all the data from the very beginning of a database to discover the resultant weighted frequent patterns. Therefore, their approaches may not be suitable for the large-scale data environment such as data streams where the volume of data is huge and unbounded. Moreover, they cannot extract the recent change of knowledge in a data stream adaptively by considering the old information which may not be interesting in the current time period. Another major limitation of the existing algorithms is to scan a database multiple times for finding the resultant weighted frequent patterns. In this paper, we propose a novel large-scale algorithm WFPMDS (Weighted Frequent Pattern Mining over Data Streams) for sliding window-based WFP mining over data streams. By using a single scan of data stream, the WFPMDS algorithm can discover important knowledge from the recent data elements. Extensive performance analyses show that our proposed algorithm is very efficient for sliding window-based WFP mining over data streams.

  13. Real time fabric defect detection system on an embedded DSP platform

    NASA Astrophysics Data System (ADS)

    Raheja, Jagdish Lal; Ajay, Bandla; Chaudhary, Ankit

    2013-11-01

    In industrial fabric productions, automated real time systems are needed to find out the minor defects. It will save the cost by not transporting defected products and also would help in making compmay image of quality fabrics by sending out only undefected products. A real time fabric defect detection system (FDDS), implementd on an embedded DSP platform is presented here. Textural features of fabric image are extracted based on gray level co-occurrence matrix (GLCM). A sliding window technique is used for defect detection where window moves over the whole image computing a textural energy from the GLCM of the fabric image. The energy values are compared to a reference and the deviations beyond a threshold are reported as defects and also visually represented by a window. The implementation is carried out on a TI TMS320DM642 platform and programmed using code composer studio software. The real time output of this implementation was shown on a monitor.

  14. The method for detecting small lesions in medical image based on sliding window

    NASA Astrophysics Data System (ADS)

    Han, Guilai; Jiao, Yuan

    2016-10-01

    At present, the research on computer-aided diagnosis includes the sample image segmentation, extracting visual features, generating the classification model by learning, and according to the model generated to classify and judge the inspected images. However, this method has a large scale of calculation and speed is slow. And because medical images are usually low contrast, when the traditional image segmentation method is applied to the medical image, there is a complete failure. As soon as possible to find the region of interest, improve detection speed, this topic attempts to introduce the current popular visual attention model into small lesions detection. However, Itti model is mainly for natural images. But the effect is not ideal when it is used to medical images which usually are gray images. Especially in the early stages of some cancers, the focus of a disease in the whole image is not the most significant region and sometimes is very difficult to be found. But these lesions are prominent in the local areas. This paper proposes a visual attention mechanism based on sliding window, and use sliding window to calculate the significance of a local area. Combined with the characteristics of the lesion, select the features of gray, entropy, corner and edge to generate a saliency map. Then the significant region is segmented and distinguished. This method reduces the difficulty of image segmentation, and improves the detection accuracy of small lesions, and it has great significance to early discovery, early diagnosis and treatment of cancers.

  15. Immunophenotyping by slide-based cytometry and by flow cytometry are comparable

    NASA Astrophysics Data System (ADS)

    Gerstner, Andreas O.; Laffers, Wiebke; Mittag, Anja; Daehnert, Ingo; Lenz, Domnik; Bootz, Friedrich; Bocsi, Jozsef; Tarnok, Attila

    2005-03-01

    Immunophenotyping of peripheral blood leukocytes (PBLs) is performed by flow cytometry (FCM) as the golden standard. Slide based cytometry systems for example laser scanning cytometer (LSC) can give additional information (repeated staining and scanning, morphology). In order to adequately judge on the clinical usefulness of immunophenotyping by LSC it is obligatory to compare it with the long established FCM assays. We performed this study to systematically compare the two methods, FCM and LSC for immunophenotyping and to test the correlation of the results. Leucocytes were stained with directly labeled monoclonal antibodies with whole blood staining method. Aliquots of the same paraformaldehyde fixed specimens were analyzed in a FACScan (BD-Biosciences) using standard protocols and parallel with LSC (CompuCyte) after placing to glass slide, drying and fixation by aceton and 7-AAD staining. Calculating the percentage distribution of PBLs obtained by LSC and by FCM shows very good correlation with regression coefficients close to 1.0 for the major populations (neutrophils, lymphocytes, and monocytes), as well as for the lymphocyte sub-populations (T-helper-, T-cytotoxic-, B-, NK-cells). LSC can be recommended for immunophenotyping of PBLs especially in cases where only very limited sample volumes are available or where additional analysis of the cells" morphology is important. There are limitations in the detection of rare leucocytes or weak antigens where appropriate amplification steps for immunofluorescence should be engaged.

  16. Site specificity of DSP-PP cleavage by BMP1.

    PubMed

    Yang, Robert T; Lim, Glendale L; Yee, Colin T; Fuller, Robert S; Ritchie, Helena H

    2014-08-01

    Bone morphogenic protein 1 (BMP1), a metalloproteinase, is known to cleave a wide variety of extracellular matrix proteins, suggesting that a consensus substrate cleavage amino acid sequence might exist. However, while such a consensus sequence has been proposed based on P4 to P4' (i.e. the four amino acids flanking either side of the BMP1 cleavage site; P4P3P2P1|P1'P2'P3'P4') sequence homologies between two BMP1 substrates, dentin matrix protein 1 and dentin sialoprotein phosphophoryn (DSP-PP) (i.e. xMQx|DDP), no direct testing has so far been attempted. Using an Sf9 cell expression system, we have been able to produce large amounts of uncleaved DSP-PP. Point mutations introduced into this recombinant DSP-PP were then tested for their effects on DSP-PP cleavage by either Sf9 endogenous tolloid-related protein 1 (TLR-1) or by its human homolog, BMP1. Here, we have measured DSP-PP cleavage efficiencies after modifications based on P4-P4' sequence comparisons with dentin matrix protein 1, as well as for prolysyl oxidase and chordin, two other BMP1 substrates. Our results demonstrate that any mutations within or outside of the DSP-PP P4 to P4' cleavage site can block, impair or accelerate DSP-PP cleavage, and suggest that its BMP1 cleavage site is highly conserved in order to regulate its cleavage efficiency, possibly with additional assistance from its conserved exosites. Thus, BMP1 cleavage cannot be based on a consensus substrate cleavage site.

  17. LC-MS/MS analysis of diarrhetic shellfish poisoning (DSP) toxins, okadaic acid and dinophysistoxin analogues, and other lipophilic toxins.

    PubMed

    Suzuki, Toshiyuki; Quilliam, Michael A

    2011-01-01

    Diarrhetic shellfish poisoning (DSP) is a severe gastrointestinal illness caused by consumption of shellfish contaminated with DSP toxins that are originally produced by toxic dinoflagellates. Based on their structures, DSP toxins were initially classified into three groups, okadaic acid (OA)/dinophysistoxin (DTX) analogues, pectenotoxins (PTXs), and yessotoxins (YTXs). Because PTXs and YTXs have been subsequently shown to have no diarrhetic activities, PTXs and YTXs have recently been eliminated from the definition of DSP toxins. Mouse bioassay (MBA), which is the official testing method of DSP in Japan and many countries, also detects PTXs and YTXs, and thus alternative testing methods detecting only OA/DTX analogues are required in DSP monitoring. Electrospray ionization (ESI) liquid chromatography-mass spectrometry (LC-MS) is a very powerful tool for the detection, identification and quantification of DSP and other lipophilic toxins. In the present review, application of ESI LC-MS techniques to the analysis of each toxin group is described.

  18. Real-time experimental demonstrations of software reconfigurable optical OFDM transceivers utilizing DSP-based digital orthogonal filters for SDN PONs.

    PubMed

    Duan, X; Giddings, R P; Bolea, M; Ling, Y; Cao, B; Mansoor, S; Tang, J M

    2014-08-11

    Real-time optical OFDM (OOFDM) transceivers with on-line software-controllable channel reconfigurability and transmission performance adaptability are experimentally demonstrated, for the first time, utilizing Hilbert-pair-based 32-tap digital orthogonal filters implemented in FPGAs. By making use of an 8-bit DAC/ADC operating at 2GS/s, an oversampling factor of 2 and an EML intensity modulator, the demonstrated RF conversion-free transceiver supports end-to-end real-time simultaneous adaptive transmissions, within a 1GHz signal spectrum region, of a 2.03Gb/s in-phase OOFDM channel and a 1.41Gb/s quadrature-phase OOFDM channel over a 25km SSMF IMDD system. In addition, detailed experimental explorations are also undertaken of key physical mechanisms limiting the maximum achievable transmission performance, impacts of transceiver's channel multiplexing/demultiplexing operations on the system BER performance, and the feasibility of utilizing adaptive modulation to combat impairments associated with low-complexity digital filter designs. Furthermore, experimental results indicate that the transceiver incorporating a fixed digital orthogonal filter DSP architecture can be made transparent to various signal modulation formats up to 64-QAM.

  19. Accuracy of reading liquid based cytology slides using the ThinPrep Imager compared with conventional cytology: prospective study

    PubMed Central

    d'Assuncao, Jefferson; Irwig, Les; Macaskill, Petra; Chan, Siew F; Richards, Adele; Farnsworth, Annabelle

    2007-01-01

    Objective To compare the accuracy of liquid based cytology using the computerised ThinPrep Imager with that of manually read conventional cytology. Design Prospective study. Setting Pathology laboratory in Sydney, Australia. Participants 55 164 split sample pairs (liquid based sample collected after conventional sample from one collection) from consecutive samples of women choosing both types of cytology and whose specimens were examined between August 2004 and June 2005. Main outcome measures Primary outcome was accuracy of slides for detecting squamous lesions. Secondary outcomes were rate of unsatisfactory slides, distribution of squamous cytological classifications, and accuracy of detecting glandular lesions. Results Fewer unsatisfactory slides were found for imager read cytology than for conventional cytology (1.8% v 3.1%; P<0.001). More slides were classified as abnormal by imager read cytology (7.4% v 6.0% overall and 2.8% v 2.2% for cervical intraepithelial neoplasia of grade 1 or higher). Among 550 patients in whom imager read cytology was cervical intraepithelial neoplasia grade 1 or higher and conventional cytology was less severe than grade 1, 133 of 380 biopsy samples taken were high grade histology. Among 294 patients in whom imager read cytology was less severe than cervical intraepithelial neoplasia grade 1 and conventional cytology was grade 1 or higher, 62 of 210 biopsy samples taken were high grade histology. Imager read cytology therefore detected 71 more cases of high grade histology than did conventional cytology, resulting from 170 more biopsies. Similar results were found when one pathologist reread the slides, masked to cytology results. Conclusion The ThinPrep Imager detects 1.29 more cases of histological high grade squamous disease per 1000 women screened than conventional cytology, with cervical intraepithelial neoplasia grade 1 as the threshold for referral to colposcopy. More imager read slides than conventional slides were

  20. Fault tolerant control based on interval type-2 fuzzy sliding mode controller for coaxial trirotor aircraft.

    PubMed

    Zeghlache, Samir; Kara, Kamel; Saigaa, Djamel

    2015-11-01

    In this paper, a robust controller for a Six Degrees of Freedom (6 DOF) coaxial trirotor helicopter control is proposed in presence of defects in the system. A control strategy based on the coupling of the interval type-2 fuzzy logic control and sliding mode control technique are used to design a controller. The main purpose of this work is to eliminate the chattering phenomenon and guaranteeing the stability and the robustness of the system. In order to achieve this goal, interval type-2 fuzzy logic control has been used to generate the discontinuous control signal. The simulation results have shown that the proposed control strategy can greatly alleviate the chattering effect, and perform good reference tracking in presence of defects in the system.

  1. Impedance Control of the Rehabilitation Robot Based on Sliding Mode Control

    NASA Astrophysics Data System (ADS)

    Zhou, Jiawang; Zhou, Zude; Ai, Qingsong

    As an auxiliary treatment, the 6-DOF parallel robot plays an important role in lower limb rehabilitation. In order to improve the efficiency and flexibility of the lower limb rehabilitation training, this paper studies the impedance controller based on the position control. A nonsingular terminal sliding mode control is developed to ensure the trajectory tracking precision and in contrast to traditional PID control strategy in the inner position loop, the system will be more stable. The stability of the system is proved by Lyapunov function to guarantee the convergence of the control errors. Simulation results validate the effectiveness of the target impedance model and show that the parallel robot can adjust gait trajectory online according to the human-machine interaction force to meet the gait request of patients, and changing the impedance parameters can meet the demands of different stages of rehabilitation training.

  2. A counting method for density packed cells based on sliding band filter image enhancement.

    PubMed

    Sui, D; Wang, K

    2013-04-01

    Cell loss and addition is an important biological event in pathology, and it usually provides central information to the changes of biological activity in the histological sections. To develop a reliable and accurate cell counting tools in tissue section, in this paper, we proposed a novel cell nuclei detecting method based on the sliding band filter which is a member of convergence index family. We evaluated the accuracy and performance of our method on density packed retinal outer nuclear layer cell confocal multivariate fluorescence microscopy image datasets. The results show our proposed method exhibited an excellent performance with its accuracy compared with human manual counting. It is worth noting that the proposed cell counting method can clearly benefit for retinal detachment and reattachment visual diagnostics close related to cell loss and addition. © 2013 The Authors Journal of Microscopy © 2013 Royal Microscopical Society.

  3. FAT-based adaptive sliding control for flexible arms: Theory and experiments

    NASA Astrophysics Data System (ADS)

    Haung, An-Chyau; Liao, Kuo-Kai

    2006-11-01

    An adaptive sliding controller is proposed in this paper for flexible arms containing time-varying uncertainties with unknown bounds based on function approximation technique (FAT). The uncertainties are firstly represented by finite linear combinations of orthonormal basis with some unknown constant weighting vectors. Output error dynamics can thus be derived as a stable first-order filter driven by parameter error vectors. Appropriate update laws for the weighting vectors are selected using the Lyapunov method so that asymptotic convergence of the output error can be proved as long as a sufficient number of basis functions are used. Effects of the approximation error on system performance are also investigated in this paper. Both computer simulation and experimental results confirm the feasibility of the proposed control strategy.

  4. Friction and wear of iron-base binary alloys in sliding contact with silicon carbide in vacuum

    NASA Technical Reports Server (NTRS)

    Miyoshi, K.; Buckley, D. H.

    1980-01-01

    Multipass sliding friction experiments were conducted with various iron base binary alloys in contact with a single crystal silicon carbide surface in vacuum. Results indicate that the atomic size and concentration of alloy elements play important roles in controlling the transfer and friction properties of iron base binary alloys. Alloys having high solute concentration produce more transfer than do alloys having low solute concentration. The coefficient of friction during multipass sliding generally increases with an increase in the concentration of alloying element. The change of friction with succeeding passes after the initial pass also increases as the solute to iron, atomic radius ratio increases or decreases from unity.

  5. Fractional order sliding-mode control based on parameters auto-tuning for velocity control of permanent magnet synchronous motor.

    PubMed

    Zhang, BiTao; Pi, YouGuo; Luo, Ying

    2012-09-01

    A fractional order sliding mode control (FROSMC) scheme based on parameters auto-tuning for the velocity control of permanent magnet synchronous motor (PMSM) is proposed in this paper. The control law of the proposed F(R)OSMC scheme is designed according to Lyapunov stability theorem. Based on the property of transferring energy with adjustable type in F(R)OSMC, this paper analyzes the chattering phenomenon in classic sliding mode control (SMC) is attenuated with F(R)OSMC system. A fuzzy logic inference scheme (FLIS) is utilized to obtain the gain of switching control. Simulations and experiments demonstrate that the proposed FROSMC not only achieve better control performance with smaller chatting than that with integer order sliding mode control, but also is robust to external load disturbance and parameter variations.

  6. MCNP-DSP users manual

    SciTech Connect

    Valentine, T.E.

    1997-01-01

    The Monte Carlo code MCNP-DSP was developed from the Los Alamos MCNP4a code to calculate the time and frequency response statistics obtained from the {sup 252}Cf-source-driven frequency analysis measurements. This code can be used to validate calculational methods and cross section data sets from subcritical experiments. This code provides a more general model for interpretation and planning of experiments for nuclear criticality safety, nuclear safeguards, and nuclear weapons identification and replaces the use of point kinetics models for interpreting the measurements. The use of MCNP-DSP extends the usefulness of this measurement method to systems with much lower neutron multiplication factors.

  7. Quantification of virtual slides: Approaches to analysis of content-based image information.

    PubMed

    Kayser, Klaus

    2011-01-07

    Virtual microscopy, which is the diagnostic work on completely digitized histological and cytological slides as well as blood smears, is at the stage to be implemented in routine diagnostic surgical pathology (tissue-based diagnosis) in the near future, once it has been accepted by the US Food and Drug Administration. The principle of content-based image information, its mandatory prerequisites to obtain reproducible and stable image information as well as the different compartments that contribute to image information are described in detail. Automated extraction of content-based image information requires shading correction, constant maximum of grey values, and standardized grey value histograms. The different compartments to evaluate image information include objects, structure, and texture. Identification of objects and derived structure depend on segmentation accuracy and applied procedures; textures contain pixel-based image information only. All together, these image compartments posses the discrimination power to distinguish between object space and background, and, in addition, to reproducibly define regions of interest (ROIs). ROIs are image areas which display the information that is of preferable interest to the viewing pathologist. They contribute to the derived diagnosis to a higher level when compared with other image areas. The implementation of content-based image information algorithms to be applied for predictive tissue-based diagnoses is described in detail.

  8. Quantification of virtual slides: Approaches to analysis of content-based image information

    PubMed Central

    Kayser, Klaus

    2011-01-01

    Virtual microscopy, which is the diagnostic work on completely digitized histological and cytological slides as well as blood smears, is at the stage to be implemented in routine diagnostic surgical pathology (tissue-based diagnosis) in the near future, once it has been accepted by the US Food and Drug Administration. The principle of content-based image information, its mandatory prerequisites to obtain reproducible and stable image information as well as the different compartments that contribute to image information are described in detail. Automated extraction of content-based image information requires shading correction, constant maximum of grey values, and standardized grey value histograms. The different compartments to evaluate image information include objects, structure, and texture. Identification of objects and derived structure depend on segmentation accuracy and applied procedures; textures contain pixel-based image information only. All together, these image compartments posses the discrimination power to distinguish between object space and background, and, in addition, to reproducibly define regions of interest (ROIs). ROIs are image areas which display the information that is of preferable interest to the viewing pathologist. They contribute to the derived diagnosis to a higher level when compared with other image areas. The implementation of content-based image information algorithms to be applied for predictive tissue-based diagnoses is described in detail. PMID:21383926

  9. Role of kinesin-1–based microtubule sliding in Drosophila nervous system development

    PubMed Central

    Winding, Michael; Kelliher, Michael T.; Lu, Wen; Wildonger, Jill

    2016-01-01

    The plus-end microtubule (MT) motor kinesin-1 is essential for normal development, with key roles in the nervous system. Kinesin-1 drives axonal transport of membrane cargoes to fulfill the metabolic needs of neurons and maintain synapses. We have previously demonstrated that kinesin-1, in addition to its well-established role in organelle transport, can drive MT–MT sliding by transporting “cargo” MTs along “track” MTs, resulting in dramatic cell shape changes. The mechanism and physiological relevance of this MT sliding are unclear. In addition to its motor domain, kinesin-1 contains a second MT-binding site, located at the C terminus of the heavy chain. Here, we mutated this C-terminal MT-binding site such that the ability of kinesin-1 to slide MTs is significantly compromised, whereas cargo transport is unaffected. We introduced this mutation into the genomic locus of kinesin-1 heavy chain (KHC), generating the KhcmutA allele. KhcmutA neurons displayed significant MT sliding defects while maintaining normal transport of many cargoes. Using this mutant, we demonstrated that MT sliding is required for axon and dendrite outgrowth in vivo. Consistent with these results, KhcmutA flies displayed severe locomotion and viability defects. To test the role of MT sliding further, we engineered a chimeric motor that actively slides MTs but cannot transport organelles. Activation of MT sliding in KhcmutA neurons using this chimeric motor rescued axon outgrowth in cultured neurons and in vivo, firmly establishing the role of sliding in axon outgrowth. These results demonstrate that MT sliding by kinesin-1 is an essential biological phenomenon required for neuronal morphogenesis and normal nervous system development. PMID:27512046

  10. Least square based sliding mode control for a quad-rotor helicopter and energy saving by chattering reduction

    NASA Astrophysics Data System (ADS)

    Sumantri, Bambang; Uchiyama, Naoki; Sano, Shigenori

    2016-01-01

    In this paper, a new control structure for a quad-rotor helicopter that employs the least squares method is introduced. This proposed algorithm solves the overdetermined problem of the control input for the translational motion of a quad-rotor helicopter. The algorithm allows all six degrees of freedom to be considered to calculate the control input. The sliding mode controller is applied to achieve robust tracking and stabilization. A saturation function is designed around a boundary layer to reduce the chattering phenomenon that is a common problem in sliding mode control. In order to improve the tracking performance, an integral sliding surface is designed. An energy saving effect because of chattering reduction is also evaluated. First, the dynamics of the quad-rotor helicopter is derived by the Newton-Euler formulation for a rigid body. Second, a constant plus proportional reaching law is introduced to increase the reaching rate of the sliding mode controller. Global stability of the proposed control strategy is guaranteed based on the Lyapunov's stability theory. Finally, the robustness and effectiveness of the proposed control system are demonstrated experimentally under wind gusts, and are compared with a regular sliding mode controller, a proportional-differential controller, and a proportional-integral-differential controller.

  11. Dynamic boundary layer based neural network quasi-sliding mode control for soft touching down on asteroid

    NASA Astrophysics Data System (ADS)

    Liu, Xiaosong; Shan, Zebiao; Li, Yuanchun

    2017-04-01

    Pinpoint landing is a critical step in some asteroid exploring missions. This paper is concerned with the descent trajectory control for soft touching down on a small irregularly-shaped asteroid. A dynamic boundary layer based neural network quasi-sliding mode control law is proposed to track a desired descending path. The asteroid's gravitational acceleration acting on the spacecraft is described by the polyhedron method. Considering the presence of input constraint and unmodeled acceleration, the dynamic equation of relative motion is presented first. The desired descending path is planned using cubic polynomial method, and a collision detection algorithm is designed. To perform trajectory tracking, a neural network sliding mode control law is given first, where the sliding mode control is used to ensure the convergence of system states. Two radial basis function neural networks (RBFNNs) are respectively used as an approximator for the unmodeled term and a compensator for the difference between the actual control input with magnitude constraint and nominal control. To improve the chattering induced by the traditional sliding mode control and guarantee the reachability of the system, a specific saturation function with dynamic boundary layer is proposed to replace the sign function in the preceding control law. Through the Lyapunov approach, the reachability condition of the control system is given. The improved control law can guarantee the system state move within a gradually shrinking quasi-sliding mode band. Numerical simulation results demonstrate the effectiveness of the proposed control strategy.

  12. Wavefront Sensing via High Speed DSP

    NASA Technical Reports Server (NTRS)

    Smith, J. Scott; Dean, Bruce

    2004-01-01

    Future light-weighted and segmented primary mirror systems require active optical control to maintain mirror positioning and figure to within nanometer tolerances. Current image-based wavefront sensing approaches rely on post-processing techniques to return an estimate of the aberrated optical wavefront with accuracies to the nanometer level. But the lag times between wavefront sensing, and then control, contributes to a significant latency in the wavefront sensing implementation. In this analysis we demonstrate accelerated image-based wavefront sensing performance using multiple digital signal processors (DSP's). The computational architecture is discussed as well as the heritage leading to the approach.

  13. Sliding mode observer based incipient sensor fault detection with application to high-speed railway traction device.

    PubMed

    Zhang, Kangkang; Jiang, Bin; Yan, Xing-Gang; Mao, Zehui

    2016-07-01

    This paper considers incipient sensor fault detection issue for a class of nonlinear systems with "observer unmatched" uncertainties. A particular fault detection sliding mode observer is designed for the augmented system formed by the original system and incipient sensor faults. The designed parameters are obtained using LMI and line filter techniques to guarantee that the generated residuals are robust to uncertainties and that sliding motion is not destroyed by faults. Then, three levels of novel adaptive thresholds are proposed based on the reduced order sliding mode dynamics, which effectively improve incipient sensor faults detectability. Case study of on the traction system in China Railway High-speed is presented to demonstrate the effectiveness of the proposed incipient senor faults detection schemes.

  14. Determination of the geometrical dimensions of the helical gears with addendum modifications based on the specific sliding equalization model

    NASA Astrophysics Data System (ADS)

    Alexandru, Antal Tiberiu; Adalbert, Antal

    The paper gives a new computational method for the determination of the geometrical dimensions of the helical gears with addendum modification based on the model of the sliding equalization at the beginning and at the ending of the meshing. In this model the sliding between the teeth's flanks during the meshing is used to increase the lifetime of the gears by uniformization at the points where the differences are highest. The variations of the addendum modification values, at different axis angles and axis distances, are determined using the MATLAB computing environment.

  15. Analytical validity of a microRNA‐based assay for diagnosing indeterminate thyroid FNA smears from routinely prepared cytology slides

    PubMed Central

    Benjamin, Hila; Schnitzer‐Perlman, Temima; Shtabsky, Alexander; VandenBussche, Christopher J.; Ali, Syed Z.; Kolar, Zdenek; Pagni, Fabio; Bar, Dganit

    2016-01-01

    BACKGROUND The majority of thyroid nodules are diagnosed using fine‐needle aspiration (FNA) biopsies. The authors recently described the clinical validation of a molecular microRNA‐based assay, RosettaGX Reveal, which can diagnose thyroid nodules as benign or suspicious using a single stained FNA smear. This paper describes the analytical validation of the assay. METHODS More than 800 FNA slides were tested, including slides stained with Romanowsky‐type and Papanicolaou stains. The assay was examined for the following features: intranodule concordance, effect of stain type, minimal acceptable RNA amounts, performance on low numbers of thyroid cells, effect of time since sampling, and analytical sensitivity, specificity, and reproducibility. RESULTS The assay can be run on FNA slides for which as little as 1% of the cells are thyroid epithelial cells or from which only 5 ng of RNA have been extracted. Samples composed entirely of blood failed quality control and were not classified. Stain type did not affect performance. All slides were stored at room temperature. However, the length of time between FNA sampling and processing did not affect assay performance. There was a high level of concordance between laboratories (96%), and the concordance for slides created from the same FNA pass was 93%. CONCLUSIONS The microRNA‐based assay was robust to various physical processing conditions and to differing sample characteristics. Given the assay's performance, robustness, and use of routinely prepared FNA slides, it has the potential to provide valuable aid for physicians in the diagnosis of thyroid nodules. Cancer Cytopathol 2016;124:711–21. © 2016 Rosetta Genomics. Cancer Cytopathology published by Wiley Periodicals, Inc. on behalf of American Cancer Society. PMID:27223344

  16. Analytical validity of a microRNA-based assay for diagnosing indeterminate thyroid FNA smears from routinely prepared cytology slides.

    PubMed

    Benjamin, Hila; Schnitzer-Perlman, Temima; Shtabsky, Alexander; VandenBussche, Christopher J; Ali, Syed Z; Kolar, Zdenek; Pagni, Fabio; Bar, Dganit; Meiri, Eti

    2016-10-01

    The majority of thyroid nodules are diagnosed using fine-needle aspiration (FNA) biopsies. The authors recently described the clinical validation of a molecular microRNA-based assay, RosettaGX Reveal, which can diagnose thyroid nodules as benign or suspicious using a single stained FNA smear. This paper describes the analytical validation of the assay. More than 800 FNA slides were tested, including slides stained with Romanowsky-type and Papanicolaou stains. The assay was examined for the following features: intranodule concordance, effect of stain type, minimal acceptable RNA amounts, performance on low numbers of thyroid cells, effect of time since sampling, and analytical sensitivity, specificity, and reproducibility. The assay can be run on FNA slides for which as little as 1% of the cells are thyroid epithelial cells or from which only 5 ng of RNA have been extracted. Samples composed entirely of blood failed quality control and were not classified. Stain type did not affect performance. All slides were stored at room temperature. However, the length of time between FNA sampling and processing did not affect assay performance. There was a high level of concordance between laboratories (96%), and the concordance for slides created from the same FNA pass was 93%. The microRNA-based assay was robust to various physical processing conditions and to differing sample characteristics. Given the assay's performance, robustness, and use of routinely prepared FNA slides, it has the potential to provide valuable aid for physicians in the diagnosis of thyroid nodules. Cancer Cytopathol 2016;124:711-21. © 2016 Rosetta Genomics. Cancer Cytopathology published by Wiley Periodicals, Inc. on behalf of American Cancer Society. © 2016 Rosetta Genomics. Cancer Cytopathology published by Wiley Periodicals, Inc. on behalf of American Cancer Society.

  17. Patch-based Convolutional Neural Network for Whole Slide Tissue Image Classification

    PubMed Central

    Hou, Le; Samaras, Dimitris; Kurc, Tahsin M.; Gao, Yi; Davis, James E.; Saltz, Joel H.

    2016-01-01

    Convolutional Neural Networks (CNN) are state-of-the-art models for many image classification tasks. However, to recognize cancer subtypes automatically, training a CNN on gigapixel resolution Whole Slide Tissue Images (WSI) is currently computationally impossible. The differentiation of cancer subtypes is based on cellular-level visual features observed on image patch scale. Therefore, we argue that in this situation, training a patch-level classifier on image patches will perform better than or similar to an image-level classifier. The challenge becomes how to intelligently combine patch-level classification results and model the fact that not all patches will be discriminative. We propose to train a decision fusion model to aggregate patch-level predictions given by patch-level CNNs, which to the best of our knowledge has not been shown before. Furthermore, we formulate a novel Expectation-Maximization (EM) based method that automatically locates discriminative patches robustly by utilizing the spatial relationships of patches. We apply our method to the classification of glioma and non-small-cell lung carcinoma cases into subtypes. The classification accuracy of our method is similar to the inter-observer agreement between pathologists. Although it is impossible to train CNNs on WSIs, we experimentally demonstrate using a comparable non-cancer dataset of smaller images that a patch-based CNN can outperform an image-based CNN. PMID:27795661

  18. Local anomaly detection algorithm based on sliding windows in spectral space

    NASA Astrophysics Data System (ADS)

    Li, Zhiyong; Zhou, Shilin; Han, Yong; Wang, Liangliang

    2014-11-01

    In this paper, a novel local ways to implement hyperspectral anomaly detector is presented. Usually, the local detectors are implemented in the spatial window of image scene, but the proposed approach is implemented on the windows of spectral space. As a multivariate data, the hyperspectral image datasets can be considered as a low-dimensional manifold embedded in the high-dimensional spectral space. In real environments, nonlinear spectral mixture occurs more frequently. At these situations, whole dataset would be distributed in one or more nonlinear manifolds in high dimensional space, such as a hyper-curve surface or nonlinear hyper-simplex. However, the majority of global and local detectors in hyperspectral image are based on the linear projections. They are established on the assumption that the geometric distribution of datasets is a linear manifold. It is incapable for them to deal with these nonlinear manifold data, even for spatial local data. In this paper, a novel anomaly detection algorithm based on local linear manifold is put forward to handle the nonlinear manifold problems. In the algorithm, the local neighborhood relationships are established in spectral space, and then an anomaly detector based on linear projection is carried out in these local areas. This situation is similar to using sliding windows in the spectral space. The results are compared with classic spatial local algorithm by using real hyperspectral image and demonstrate the effectiveness in improving the weak anomalies detection and decreasing the false alarms.

  19. STS-44 Defense Support Program (DSP) / IUS during preflight operations

    NASA Technical Reports Server (NTRS)

    1991-01-01

    STS-44 Defense Support Program (DSP) satellite atop the inertial upper stage (IUS) is prepared for transfer in a processing facility at Cape Canaveral Air Force Station. Clean-suited technicians overseeing the operation are dwarfed by the size of the 5,200-pound DSP satellite and the IUS. The underside of the IUS (bottom) mounted in the airborne support equipment (ASE) aft frame tilt actuator (AFTA) table and ASE forward frame is visible at the base. The umbilical boom between the two ASE frames and the forward frame keel trunnion are visible. DSP, a surveillance satellite that can detect missle and space launches as well as nuclear detonations will be boosted into geosynchronous Earth orbit by the IUS. View provided by KSC with alternate number KSC-91PC-1749.

  20. Finite-time control for nonlinear spacecraft attitude based on terminal sliding mode technique.

    PubMed

    Song, Zhankui; Li, Hongxing; Sun, Kaibiao

    2014-01-01

    In this paper, a fast terminal sliding mode control (FTSMC) scheme with double closed loops is proposed for the spacecraft attitude control. The FTSMC laws are included both in an inner control loop and an outer control loop. Firstly, a fast terminal sliding surface (FTSS) is constructed, which can drive the inner loop tracking-error and the outer loop tracking-error on the FTSS to converge to zero in finite time. Secondly, FTSMC strategy is designed by using Lyaponov's method for ensuring the occurrence of the sliding motion in finite time, which can hold the character of fast transient response and improve the tracking accuracy. It is proved that FTSMC can guarantee the convergence of tracking-error in both approaching and sliding mode surface. Finally, simulation results demonstrate the effectiveness of the proposed control scheme.

  1. Dry Sliding Wear Behavior of Hafnium-Based Bulk Metallic Glass at Room and Elevated Temperatures

    NASA Astrophysics Data System (ADS)

    Keshri, Anup Kumar; Behl, Lovish; Lahiri, Debrupa; Dulikravich, George S.; Agarwal, Arvind

    2016-09-01

    Dry sliding wear behavior of hafnium-based bulk metallic glass was studied at two loads (5 and 15 N) and two temperatures (298 and 673 K) using aluminum oxide (Al2O3) ball as a wear counterpart. At 5 N load, wear reduced by ~71% on increasing the temperature from 298 to 673 K. At a higher load of 15 N, the weight loss reduction was much lower (45%) on increasing the temperature from 298 to 673 K. Decreased wear weight loss on increasing the temperature was attributed to the increased hardness of the Hf-based metallic glass at high temperatures. Micro-hardness of the alloy at 293 K was found to be 636 Hv, which gradually increased to 655 Hv on annealing at 673 K. Improvement in the hardness at elevated temperature is attributed to: (1) free volume annihilation, (2) surface oxide formation and (3) nano-crystallites precipitation. Reduced wear at elevated temperature resulted in smaller volume of debris generation that restricted three-body wear to obtain lower coefficient of friction (COF) (0.25-0.35) compared to COF (0.65-0.75) at room temperature.

  2. A Double-Wing Chaotic System Based on Ion Migration Memristor and Its Sliding Mode Control

    NASA Astrophysics Data System (ADS)

    Min, Guoqi; Duan, Shukai; Wang, Lidan

    The ion migration memristor is a nonlinear element with memory function and nanoscale size, it is considered as a potential candidate to reduce system power consumption and circuit size. When it works as the nonlinear part of the chaotic system, rich nonlinear curves will be produced, and at the same time, the complexity of chaotic systems and the randomness of signals will be enhanced. So in this paper, by Matlab numerical simulation, a new double-wing chaotic system based on an ion migration memristor is designed. In reality, there are many systems interfered inevitably by random noise, so in this paper the random bounded noises are also considered. The power spectrum, Lyapunov exponent spectrum, Poincaré map and bifurcation diagram are used to investigate its complex dynamic characteristics. Then, a SPICE-based analog circuit is presented to verify the feasibility of the system, for which the simulation results are consistent with the numerical simulation. Finally, the sliding mode variable structure control is applied to overcome the shortcomings of traditional control method, so that the chaotic orbits can be controlled to any fixed points or periodic orbits, and this provides an insight into chaos control in power electronics systems.

  3. Geometric-attributes-based segmentation of cortical bone slides using optimized neural networks.

    PubMed

    Hage, Ilige S; Hamade, Ramsey F

    2016-05-01

    In cortical bone, solid (lamellar and interstitial) matrix occupies space left over by porous microfeatures such as Haversian canals, lacunae, and canaliculi-containing clusters. In this work, pulse-coupled neural networks (PCNN) were used to automatically distinguish the microfeatures present in histology slides of cortical bone. The networks' parameters were optimized using particle swarm optimization (PSO). When forming the fitness functions for the PSO, we considered the microfeatures' geometric attributes-namely, their size (based on measures of elliptical perimeter or area), shape (based on measures of compactness or the ratio of minor axis length to major axis length), and a two-way combination of these two geometric attributes. This hybrid PCNN-PSO method was further enhanced for pulse evaluation by combination with yet another method, adaptive threshold (AT), where the PCNN algorithm is repeated until the best threshold is found corresponding to the maximum variance between two segmented regions. Together, this framework of using PCNN-PSO-AT constitutes, we believe, a novel framework in biomedical imaging. Using this framework and extracting microfeatures from only one training image, we successfully extracted microfeatures from other test images. The high fidelity of all resultant segments was established using quantitative metrics such as precision, specificity, and Dice indices.

  4. The Reloca Slide offshore Central Chile (35.5°S) - a Revision Based on Geotechnical Sliding Plane Characterization and Tsunami Modeling

    NASA Astrophysics Data System (ADS)

    Voelker, D.; Kopf, A.; Ikari, M.; Trütner, S.

    2015-12-01

    Reloca Slide is a submarine failure of ~ 24 km3 volume at the lower slope of the continental margin of Central Chile. The sliding event appears to be of post-Last Glacial Maximum (LGM) age. The evacuation site exhibits a 30° steep and 2000 m high failure plane, the slide deposits in the Chile Trench are preserved as scattered 10-600 m high angular blocks incorporated in a ~60 m high debris fan. The combination of a steep and high failure surface (high velocity) and the apparent cohesiveness of the displaced material (little disintegration) makes Reloca Slide a likely source for a local tsunami. Our numerical simulations show that a comparable event at the lower slope would generate waves of > 8 m offshore amplitude that would impact the Chilean coast within ~25 minutes. Reloca Slide is unique along the Central Chilean margin by its size and particular morphology. Yet, much of the unfailed lower slope along a ~1500 km long stretch shares general morphology, tectonic situation and sedimentary properties with the Reloca Slide source region. It is therefore of high relevance for risk mitigation to understand preconditioning factors and triggering mechanisms of as critical boundary conditions for similar potential future events. Core samples were taken directly from the failure plane, oedometer tests indicate a former burial depth of ~ 500 m. Samples are used to run geotechnical experiments for an improved understanding of the mechanics of the failure process. We are particularly interested in the question of whether the failure of the lowermost slope is a continuing process linked to the subduction of the Nazca Plate (e.g. a process needed to re-establish a critically tapered accretionary wedge), or, alternatively, if it is related to particular local conditions or an exceptional triggering event. We report on results from direct and rotary shear experiments to characterize frictional properties and strength of the materials at the detachment surface of the slide.

  5. Model based design of an intercooled dual stage sliding vane rotary compressor system

    NASA Astrophysics Data System (ADS)

    Cipollone, Roberto; Bianchi, Giuseppe; Di Battista, Davide; Contaldi, Giulio; Murgia, Stefano

    2015-08-01

    Energy saving is currently one of the most important driving factors for innovation all over the world. With reference to global electricity consumptions, electrical energy for compressed air production accounts for 4-5%. Among the rotary compressor technologies, Sliding Vane Rotary Compressors (SVRC) are characterized by noteworthy specific energy consumptions and demonstrated an unforeseen energy saving potential thanks to some intrinsic features specifically related to this kind of machines. The paper presents a further reduction strategy to lower energy consumptions in compressed air systems using SVRCs that relies on the combination of the recent use of a pressure swirled oil injection technology and a dual stage intercooling. The synergy between technologies already mature approaches to the lowest energy consumption and candidates SVRCs as superior machines in the energy context. The saving potential compared to the technology at the state of the art was evaluated thanks to a comprehensive mathematical modeling of the two compressor sections and the intercooling heat exchanger and fan. Results showed a reduction of the electrical power required to drive the compressor system up to 9.5%. The overall approach represents a model-based design for a new machine which is under development.

  6. Confocal epifluorescence sensor with an arc-shaped aperture for slide-based PCR quantification.

    PubMed

    Weng, Jui-Hong; Chen, Lin-Chi

    2017-08-24

    The increasing needs of point-of-care diagnostics, quarantine of epidemic pathogens, and prevention of terrorism's bio-attacks have promised the future of portable real-time quantitative polymerase chain reaction (qPCR) sensors. This work aims at developing a highly sensitive and low-cost light emitting diode (LED)-based epifluorescence sensor module for qPCR sensor development and relevant bioassay applications. Inspired by the light stop design and dark-field detection of microscopes, this paper first reports a compact confocal LED epifluorescence sensor using a light stop with an arc-shaped aperture for enhancing the flexibility of quick DNA and PCR detection. The sensor features the advantages of the dichroic mirror-free and confocal (shared-focus) characteristics, which benefits size reduction and minimal optics used. It also allows extension to integrate with in situ real-time PCR thermal cycling since the sample slide is placed apart from the epi-sensing module. The epifluorescence sensor can detect as low as sub-ng/μL standard DNA and 10(1) copies of Salmonella typhimurium InvA gene sequences (cloned in E. coli and after 30-cycle PCR) with SYBR(®) Green I from non-purified culture samples, having highly sensitive and specific signal responses comparable with that of a commercial qPCR instrument. Copyright © 2017 Elsevier B.V. All rights reserved.

  7. State observer-based sliding mode control for semi-active hydro-pneumatic suspension

    NASA Astrophysics Data System (ADS)

    Ren, Hongbin; Chen, Sizhong; Zhao, Yuzhuang; Liu, Gang; Yang, Lin

    2016-02-01

    This paper proposes an improved virtual reference model for semi-active suspension to coordinate the vehicle ride comfort and handling stability. The reference model combines the virtues of sky-hook with ground-hook control logic, and the hybrid coefficient is tuned according to the longitudinal and lateral acceleration so as to improve the vehicle stability especially in high-speed condition. Suspension state observer based on unscented Kalman filter is designed. A sliding mode controller (SMC) is developed to track the states of the reference model. The stability of the SMC strategy is proven by means of Lyapunov function taking into account the nonlinear damper characteristics and sprung mass variation of the vehicle. Finally, the performance of the controller is demonstrated under three typical working conditions: the random road excitation, speed bump road and sharp acceleration and braking. The simulation results indicated that, compared with the traditional passive suspension, the proposed control algorithm can offer a better coordination between vehicle ride comfort and handling stability. This approach provides a viable alternative to costlier active suspension control systems for commercial vehicles.

  8. Droplet sampling of an oil-based and two water-based antievaporant ultra-low volume insecticide formulations using Teflon- and magnesium oxide-coated slides.

    PubMed

    Chaskopoulou, Alexandra; Latham, Mark D; Pereira, Roberto M; Koehler, Philip G

    2013-06-01

    We estimated the diameters below which 50% and 90% of the volume of droplets exist (Dv50 and Dv90, respectively) of 1 oil-based (Permanone 30-30) and 2 water-based (AquaReslin, Aqua-K-Othrine) antievaporant aerosols (with the Film Forming Aqueous Spray Technology [FFAST]) using Teflon- and magnesium oxide (MgO)-coated slides and determined whether the aging of the droplets on the slides (up to 60 min) exhibited any significant effect on Dv50 and Dv90 calculations. There were no significant differences in either Dv50 or Dv90 estimates on MgO-coated slides at 0 min and 60 min for all 3 products tested. On Teflon-coated slides, the only product that showed significant difference between 0 min and 60 min in both Dv50 and Dv90 estimates was Aqua-K-Othrine, perhaps due to a difference in formulation components. Specifically, both values corresponding to Dv50 and Dv90 at 60 min decreased by approximately 50% when compared to the values at 0 min. For the other 2 products, AquaReslin and Permanone, aging of droplets on Teflon up to 60 min did not have any significant effect on Dv50 and Dv90 values. To further investigate the behavior of Aqua-K-Othrine droplets on Teflon-coated slides we observed the droplets immediately after spraying and at 10-min intervals under different conditions of temperature and humidity. The majority of the shrinkage occurred within the 1st 10 min after impaction on the slides under all conditions tested. So in most field situations where slides are read several hours or days after collection, this shrinkage would not be observed. The MgO-coated slides should be the preferred field method for sampling droplets of Aqua-K-Othirne with the FFAST antievaporant technology.

  9. Differential expression between "DSP-only" and DSP-PP523 transcripts in rat molar teeth.

    PubMed

    Zhu, Ya-Qin; Song, Ryan M; Ritchie, Helena H

    2017-10-01

    To compare the expression patterns of two multiple transcripts derived from DSP-PP gene during tooth development. One is DSP-only transcript (i.e. does not encode PP) and the other is DSP-PP523 transcript, a main DSP-PP transcript. Unique antisense and sense riboprobes were generated from DSP-only and DSPPP523 cDNAs for in situ studies to examine DSP-only and DSP-PP523 transcript expression in developing molars. Paraffin-embedded sections (5-7μ m) from embryonic 20day, postnatal 2, 3 and 6days were deparaffined and hydrated. Tissues were prehybridized, then hybridized with DSP-only and DSP-PP523 anti-sense (AS) or sense (S) Digoxigenin labeled-riboprobes overnight, and washed. Anti-Digoxigenin antibodies conjugated to alkaline phosphatase were used to detect the presence of bound riboprobes by color reaction with NBT/BCIP. Stro-1 antibody was used for immunohistochemical analysis of Stro-1 protein expression in rat molars. We found that unlike the DSP-PP523 transcript, the DSP-only transcript does not express in the entire polarized mature odontoblasts but is expressed in the areas subjacent to the mature odontoblast layer. In addition, DSP-only transcript is expressed in the dental pulp. Interestingly, Stro-1 protein, a stem cell marker, was also identified in the areas subjacentto odontoblasts and in dental pulp. Differential expression of DSP-only and DSP-PP523 transcripts suggest that these two kinds of transcripts may play different roles during dentinogenesis. DSP-PP523 transcript is expressed in mature odontoblasts, which actively participates in dentin formation. DSP-only transcript might have a different function. Copyright © 2017 Elsevier Ltd. All rights reserved.

  10. Evaluation and optimization for liquid-based preparation cytology in whole slide imaging

    PubMed Central

    Lee, Roy E.; McClintock, David S.; Laver, Nora M.; Yagi, Yukako

    2011-01-01

    Background: Cytology poses different obstacles in whole slide imaging compared to surgical pathology slides. A single focal plane suffices for most of the latter, but cytology slides are thicker, potentially requiring multiple focal planes for adequate diagnostic information. Multiple focal planes adversely impact scanning time per slide, evaluation times, and file sizes. In this pilot study, we evaluated and compared the multilayer stack method to the extended focus algorithm as an alternative which collapses multiple focal planes into a single image, retaining only focused areas from each plane. Materials and Methods: 10 SurePath® cervical cytology slides were scanned at three thickness settings: 18, 24, and 30 μm. Three scanners were used: (1) Hamamatsu Nanozoomer 2.0-HT, (2) 3DHISTECH Mirax scan, and (3) Bioimagene iScan Coreo Au. The Nanozoomer and iScan utilized multilayer stacking, while the Mirax files were composited by extended focus. Scan times and file sizes were recorded, and image quality compared. Results: The Nanozoomer stacks averaged 1.58 gb and around 25 min for each slide, while the iScan stacks ranged from 6.23 to 9.3 gb and took 34-50 min to scan. The Mirax images averaged 210 mb and took 13-20 min to scan. Multilayer stack image quality from both Nanozoomer and iScan was fairly comparable. The iScan revealed significant mechanical issues that did not correspond to user settings. The Mirax images showed worrisome loss of crisp focus detail, worsening with increasing focal planes and impacting assessment of nuclear contours and chromatin detail. Conclusions: The optimal number of focal planes remains unknown for cytology. Multilayer stacks require excessive scanning time, network bandwidth, and file storage. Extended focus was evaluated as an alternative, but significant image quality issues were revealed. Further large-scale studies are needed to assess their clinical impact. PMID:22059147

  11. RTDS implementation of an improved sliding mode based inverter controller for PV system.

    PubMed

    Islam, Gazi; Muyeen, S M; Al-Durra, Ahmed; Hasanien, Hany M

    2016-05-01

    This paper proposes a novel approach for testing dynamics and control aspects of a large scale photovoltaic (PV) system in real time along with resolving design hindrances of controller parameters using Real Time Digital Simulator (RTDS). In general, the harmonic profile of a fast controller has wide distribution due to the large bandwidth of the controller. The major contribution of this paper is that the proposed control strategy gives an improved voltage harmonic profile and distribute it more around the switching frequency along with fast transient response; filter design, thus, becomes easier. The implementation of a control strategy with high bandwidth in small time steps of Real Time Digital Simulator (RTDS) is not straight forward. This paper shows a good methodology for the practitioners to implement such control scheme in RTDS. As a part of the industrial process, the controller parameters are optimized using particle swarm optimization (PSO) technique to improve the low voltage ride through (LVRT) performance under network disturbance. The response surface methodology (RSM) is well adapted to build analytical models for recovery time (Rt), maximum percentage overshoot (MPOS), settling time (Ts), and steady state error (Ess) of the voltage profile immediate after inverter under disturbance. A systematic approach of controller parameter optimization is detailed. The transient performance of the PSO based optimization method applied to the proposed sliding mode controlled PV inverter is compared with the results from genetic algorithm (GA) based optimization technique. The reported real time implementation challenges and controller optimization procedure are applicable to other control applications in the field of renewable and distributed generation systems. Copyright © 2015 ISA. Published by Elsevier Ltd. All rights reserved.

  12. DSP-based adaptive backstepping using the tracking errors for high-performance sensorless speed control of induction motor drive.

    PubMed

    Zaafouri, Abderrahmen; Ben Regaya, Chiheb; Ben Azza, Hechmi; Châari, Abdelkader

    2016-01-01

    This paper presents a modified structure of the backstepping nonlinear control of the induction motor (IM) fitted with an adaptive backstepping speed observer. The control design is based on the backstepping technique complemented by the introduction of integral tracking errors action to improve its robustness. Unlike other research performed on backstepping control with integral action, the control law developed in this paper does not propose the increase of the number of system state so as not increase the complexity of differential equations resolution. The digital simulation and experimental results show the effectiveness of the proposed control compared to the conventional PI control. The results analysis shows the characteristic robustness of the adaptive control to disturbances of the load, the speed variation and low speed.

  13. DSP implementation of wavelet image enhancement

    NASA Astrophysics Data System (ADS)

    Bai, Wenruo; Zhang, Baofeng; Bai, Qianqian

    2008-03-01

    The paper presents a new Adaptive Gain calculating approach when using the Adaptive Image Enhancement algorithm based on Wavelet Transform. The basic technique is to select two different thresholds which divide the input into three parts after the wavelet coefficients are normalized. For the wavelet coefficients less than the smaller threshold, just make the output zero. And this provides a de-noise effect. The output remains unchanged when the wavelet coefficients are greater than the larger one. For the last part, find a function to make the output figure S shape. So the algorithm can give a clear contrast and the function is the key. The final goal is to use this method in the process of Online Vision Measure, we have chosen the TI TMS320 DM642 Digital Signal Processor or DSP because of its powerful multimedia processing capability. What's more, the TI corporation has provided a variety of software develop libraries as well as the 3rd party tools. All such tools make the development more rapid and convenient. After the technique this paper provides is implemented on DSP, a series of optimization will be performed to make it suitable for industry real-time usage.

  14. A generic DSP-based real-time simulator with application to hydrogenerator speed controller development. [Digital Signal Processor

    SciTech Connect

    Throckmorton, P.J.; Wozniak, L. . Dept. of General Engineering)

    1994-06-01

    This paper presents the features and evaluation of a digital signal processor/personal computer-based simulator which allows the simultaneous simulation of two linear systems in real time. A desire to gain the ability to evaluate hydrogenerator governors (speed controllers) in forms completely equivalent to that which could be used to control actual hydrogenerators is the primary motivation for this work. The simulator is designed so that one linear system nay be conceptualized as an error controller while the second system may be thought of as a plant under control. The simulator is specialized in that it allows direct entry of the hydrogenerator system parameter values of one of two linearized hydrogenerating system plant models. An option to enter the gains of a generic PID controller also exists. This PID controller may be utilized to simulate a governor for a hydrogenerator, thus allowing the real-time simulation of a closed-loop speed-controlled hydrogenerating system. Simulation accuracy is established by comparing computed results to those computed by an accepted standard'' software package. An IBM-compatible personal computer and a modified Texas Instruments TMS320C30 digital signal processor evaluation module are the primary hardware used.

  15. Use of DNA stains in immunophenotyping by slide-based cytometry

    NASA Astrophysics Data System (ADS)

    Gerstner, Andreas O. H.; Laffers, Wiebke; Bootz, Friedrich; Tarnok, Attila

    2003-06-01

    Immunophenotyping of peripheral blood leukocytes (PBL) is a very well documented application of Slide Based Cytometry (SBC). As for any other assay it is of highest importance to ensure that all cells which are relevant for an analysis are recognized. Unlike assays for cultured cells which have homogenous morphology immunophenotyping of PBLs is performed on cells with heterogeneous size and shape. Therefore, triggering on parameters related to cell morphology might lead to an incomplete analysis of just a subset of cells especially in pathological conditions. Several dyes stain DNA specifically in a wide variety of emission spectra. Many of them show some influence of the chromatin condensation and organization on the staining intensity. DNA dyes therefore can be used to differentiate between cell types having the same ploidy. This can be exploited for immunophenotyping since some dyes therefore can partially replace antibody staining. The concept of using DNA dyes in the setting of immunostaining has the following advantages: (1) nuclear staining provides a stable and easy triggering signal that guarantees both, that neither cells are excluded nor that debris or polluting particles are included into the analysis; (2) some DNA dyes differentiate between mononuclear and polymorphonuclear cells. A disadvantage of DNA dyes is that mostly cells have to be permeabilized. Because of this only one set of immunophenotypic markers can be stained, cells are fixed and permeabilized, and then nuclei are stained with the appropriate DNA dye. In the study we demonstrate the use of the most commonly available DNA dyes (7-AAD, To-Pro, To-To, PI etc.) in their applicability in immunophenotyping. An overview of spectral properties, fluorescence spill-over and optimal combinations with surface antigen staining will be shown. As in general for SBC only very small sample volumes are needed. This allows to serially analyze PBL in clinical settings that up to now could not be studied in

  16. Robust fractional order sliding mode control of doubly-fed induction generator (DFIG)-based wind turbines.

    PubMed

    Ebrahimkhani, Sadegh

    2016-07-01

    Wind power plants have nonlinear dynamics and contain many uncertainties such as unknown nonlinear disturbances and parameter uncertainties. Thus, it is a difficult task to design a robust reliable controller for this system. This paper proposes a novel robust fractional-order sliding mode (FOSM) controller for maximum power point tracking (MPPT) control of doubly fed induction generator (DFIG)-based wind energy conversion system. In order to enhance the robustness of the control system, uncertainties and disturbances are estimated using a fractional order uncertainty estimator. In the proposed method a continuous control strategy is developed to achieve the chattering free fractional order sliding-mode control, and also no knowledge of the uncertainties and disturbances or their bound is assumed. The boundedness and convergence properties of the closed-loop signals are proven using Lyapunov׳s stability theory. Simulation results in the presence of various uncertainties were carried out to evaluate the effectiveness and robustness of the proposed control scheme.

  17. A fault-tolerant attitude control system for a satellite based on fuzzy global sliding mode control algorithm

    NASA Astrophysics Data System (ADS)

    Liang, Jinjin; Dong, Chaoyang; Wang, Qing

    2008-10-01

    The structures and missions of modern satellites are very complicated, so the reliability of satellites is becoming increasingly important. This paper proposed a fault-tolerant attitude control system for a satellite based on Fuzzy Global Sliding Mode Control (FGSMC) algorithm. We designed a controller for the nonlinear model of a satellite. By designing a global sliding surface, this controller can ensure that the response of the system has global robustness against the uncertainties of system and external disturbances. In this paper attitude control is performed by four reaction flywheels. The attitude control system distributed the three control torques to the four reaction flywheels according to the distribution matrix. We deduced the formula to calculate the distribution matrix. Paper proved the stability of the designed control law, and simulated the attitude control system. The simulation results show that the attitude control law has high accuracy and robustness.

  18. Nonlinear Fractional Sliding Mode Controller Based on Reduced Order FNPK Model for Output Power Control of Nuclear Research Reactors

    NASA Astrophysics Data System (ADS)

    Davijani, Nafiseh Zare; Jahanfarnia, Gholamreza; Abharian, Amir Esmaeili

    2017-01-01

    One of the most important issues with respect to nuclear reactors is power control. In this study, we designed a fractional-order sliding mode controller based on a nonlinear fractional-order model of the reactor system in order to track the reference power trajectory and overcome uncertainties and external disturbances. Since not all of the variables in an operating reactor are measurable or specified in the control law, we propose a reduced-order fractional neutron point kinetic (ROFNPK) model based on measurable variables. In the design, we assume the differences between the approximated model and the real system is limited. We use the obtained model in the controller design process and use the Lyapunov method to perform a stability analysis of the closed-loop system. We simulate the proposed reduced-order fractional-order sliding mode controller (ROFOSMC) using Matlab/Simulink, and its performance is compared with that of a reduced order integer-order sliding mode controller (ROIOSMC). Our simulation results indicate an acceptable performance of the proposed approach in tracking the reference power trajectory with respect to ROIOSMC because of faster response of control effort signal and the smaller tracking error. Moreover, the results illustrate the capability of the controller in rejection of the disturbance and the noise signals and the robustness of controller against uncertainty.

  19. STS-44 DSP / IUS spacecraft tilted to predeployment position in OV-104's PLB

    NASA Technical Reports Server (NTRS)

    1991-01-01

    STS-44 Defense Support Program (DSP) / Inertial Upper Stage (IUS) spacecraft, with forward airborne support equipment (ASE) payload retention latch actuator released (foreground), is raised to a 29 degree predeployment position by the ASE aft frame tilt actuator (AFTA) table in the payload bay (PLB) of Atlantis, Orbiter Vehicle (OV) 104. Underneath the DSP / IUS combination, the umbilical boom is connected to the IUS. DSP components include Infrared (IR) sensor (top), AR I, SHF Antenna, EHF Antenna, Link 2 High-Gain Antenna, star sensor, and stowed solar paddles (box-like structure around the base). The Earth's limb and the blackness of space create the backdrop for this deployment scene.

  20. DSPACE: A New Space DSP Development

    NASA Astrophysics Data System (ADS)

    Errico, Walter; Colonna, Annamaria; Piscopiello, Giuseppe; Tosi, Pietro; Bacci, Bruno; Pii, Vincenzo; Fanucci, Luca; Saponara, Sergio; Donati, Massimiliano; Vincenzi, Alessandro; Reiter, Frederic; Nuzzolo, Francesco; Leupers, Rainer; Odendahl, Maximilian; Yakoushkin, Sergey

    2012-08-01

    The need for a next generation of European space- qualified Digital Signal Processors (DSP) is well known to the space community. DSPACE is a research project whose goal is to design and develop a new high- performance floating-point DSP core for space applications. This paper describes the objectives of the DSPACE project, its design approach, and the technical results achieved so far.

  1. Position synchronised control of multiple robotic manipulators based on integral sliding mode

    NASA Astrophysics Data System (ADS)

    Zhao, Dongya; Zhu, Quanmin

    2014-03-01

    In this study, a new position synchronised control algorithm is developed for multiple robotic manipulator systems. In the merit of system synchronisation and integral sliding mode control, the proposed approach can stabilise position tracking of each robotic manipulator while coordinating its motion with the other manipulators. With the integral sliding mode, the proposed approach has insensitiveness against the lumped system uncertainty within the entire process of operation. Further, a perturbation estimator is proposed to reduce chattering effect. The corresponding stability analysis is presented to lay a foundation for theoretical understanding to the underlying issues as well as safely operating real systems. An illustrative example is bench tested to validate the effectiveness of the proposed approach.

  2. Numerical analysis of the transportation characteristics of a self-running sliding stage based on near-field acoustic levitation.

    PubMed

    Feng, Kai; Liu, Yuanyuan; Cheng, Miaomiao

    2015-12-01

    Owing to its distinct non-contact and oil-free characteristics, a self-running sliding stage based on near-field acoustic levitation can be used in an environment, which demands clean rooms and zero noise. This paper presents a numerical analysis on the lifting and transportation capacity of a non-contact transportation system. Two simplified structure models, namely, free vibration and force vibration models, are proposed for the study of the displacement amplitude distribution of two cases using the finite element method. After coupling the stage displacement into the film thickness, the Reynolds equation is solved by the finite difference method to obtain the lifting and thrusting forces. Parametric analyses of the effects of amplitude, frequency, and standing wave ratio (SWR) on the sliding stage dynamic performance are investigated. Numerical results show good agreement with published experimental values. The predictions also reveal that greater transportation capacity of the self-running sliding stage is generally achieved at less SWR and at higher amplitude.

  3. Fast GPU-based segmentation of H&E stained squamous epithelium from multi-gigapixel tiled virtual slides

    NASA Astrophysics Data System (ADS)

    Bryant, Benjamin; Sari-Sarraf, Hamed; Wachtel, Mitchell; Long, Rodney; Antani, Sameer

    2013-03-01

    The processing of multi-gigapixel virtual histology slides presents a computationally intensive and time consuming task. Common tiled TIFF slide formats, such as those used by Aperio [1], contain inherent header information that can be used to rapidly locate tissue regions for cervical intraepithelial neoplasia (CIN) diagnosis. Tiles used in these formats are individually compressed subsections of the virtual slide, whose compression ratio varies based on their individual content. This paper discusses a method that exploits this information to rapidly identify regions of interest in an iterative process to locate epithelial tissue. These regions are decompressed using a multi-core CPU, from which a Compute Unified Device Architecture (CUDA) enabled GPU rapidly generates features and Support Vector Machine (SVM) decisions. SVM classifier results are used in a post-processing scheme to remove apparently spurious misclassifications. The mean overall execution time when using a high-end desktop PC, together with a GTX 560 GPU, is roughly 3 seconds per gigapixel, while maintaining the area under an ROC curve above 0.9 when classifying squamous epithelium versus other tissues.

  4. Lateral-torsional response of base-isolated buildings with curved surface sliding system subjected to near-fault earthquakes

    NASA Astrophysics Data System (ADS)

    Mazza, Fabio

    2017-08-01

    The curved surface sliding (CSS) system is one of the most in-demand techniques for the seismic isolation of buildings; yet there are still important aspects of its behaviour that need further attention. The CSS system presents variation of friction coefficient, depending on the sliding velocity of the CSS bearings, while friction force and lateral stiffness during the sliding phase are proportional to the axial load. Lateral-torsional response needs to be better understood for base-isolated structures located in near-fault areas, where fling-step and forward-directivity effects can produce long-period (horizontal) velocity pulses. To analyse these aspects, a six-storey reinforced concrete (r.c.) office framed building, with an L-shaped plan and setbacks in elevation, is designed assuming three values of the radius of curvature for the CSS system. Seven in-plan distributions of dynamic-fast friction coefficient for the CSS bearings, ranging from a constant value for all isolators to a different value for each, are considered in the case of low- and medium-type friction properties. The seismic analysis of the test structures is carried out considering an elastic-linear behaviour of the superstructure, while a nonlinear force-displacement law of the CSS bearings is considered in the horizontal direction, depending on sliding velocity and axial load. Given the lack of knowledge of the horizontal direction at which near-fault ground motions occur, the maximum torsional effects and residual displacements are evaluated with reference to different incidence angles, while the orientation of the strongest observed pulses is considered to obtain average values.

  5. MCNP-DSP USERS MANUAL

    SciTech Connect

    Valentine, T.E.

    2001-01-19

    The Monte Carlo code MCNP-DSP was developed from the Los Alamos MCNP4a code to calculate the time and frequency response statistics obtained from subcritical measurements. The code can be used to simulate a variety of subcritical measurements including source-driven noise analysis, Rossi-{alpha}, pulsed source, passive frequency analysis, multiplicity, and Feynman variance measurements. This code can be used to validate Monte Carlo methods and cross section data sets with subcritical measurements and replaces the use of point kinetics models for interpreting subcritical measurements.

  6. Sliding mode based fault detection, reconstruction and fault tolerant control scheme for motor systems.

    PubMed

    Mekki, Hemza; Benzineb, Omar; Boukhetala, Djamel; Tadjine, Mohamed; Benbouzid, Mohamed

    2015-07-01

    The fault-tolerant control problem belongs to the domain of complex control systems in which inter-control-disciplinary information and expertise are required. This paper proposes an improved faults detection, reconstruction and fault-tolerant control (FTC) scheme for motor systems (MS) with typical faults. For this purpose, a sliding mode controller (SMC) with an integral sliding surface is adopted. This controller can make the output of system to track the desired position reference signal in finite-time and obtain a better dynamic response and anti-disturbance performance. But this controller cannot deal directly with total system failures. However an appropriate combination of the adopted SMC and sliding mode observer (SMO), later it is designed to on-line detect and reconstruct the faults and also to give a sensorless control strategy which can achieve tolerance to a wide class of total additive failures. The closed-loop stability is proved, using the Lyapunov stability theory. Simulation results in healthy and faulty conditions confirm the reliability of the suggested framework.

  7. Robust fault tolerant control based on sliding mode method for uncertain linear systems with quantization.

    PubMed

    Hao, Li-Ying; Yang, Guang-Hong

    2013-09-01

    This paper is concerned with the problem of robust fault-tolerant compensation control problem for uncertain linear systems subject to both state and input signal quantization. By incorporating novel matrix full-rank factorization technique with sliding surface design successfully, the total failure of certain actuators can be coped with, under a special actuator redundancy assumption. In order to compensate for quantization errors, an adjustment range of quantization sensitivity for a dynamic uniform quantizer is given through the flexible choices of design parameters. Comparing with the existing results, the derived inequality condition leads to the fault tolerance ability stronger and much wider scope of applicability. With a static adjustment policy of quantization sensitivity, an adaptive sliding mode controller is then designed to maintain the sliding mode, where the gain of the nonlinear unit vector term is updated automatically to compensate for the effects of actuator faults, quantization errors, exogenous disturbances and parameter uncertainties without the need for a fault detection and isolation (FDI) mechanism. Finally, the effectiveness of the proposed design method is illustrated via a model of a rocket fairing structural-acoustic.

  8. Robust Sliding Mode Control Based on GA Optimization and CMAC Compensation for Lower Limb Exoskeleton.

    PubMed

    Long, Yi; Du, Zhi-Jiang; Wang, Wei-Dong; Dong, Wei

    2016-01-01

    A lower limb assistive exoskeleton is designed to help operators walk or carry payloads. The exoskeleton is required to shadow human motion intent accurately and compliantly to prevent incoordination. If the user's intention is estimated accurately, a precise position control strategy will improve collaboration between the user and the exoskeleton. In this paper, a hybrid position control scheme, combining sliding mode control (SMC) with a cerebellar model articulation controller (CMAC) neural network, is proposed to control the exoskeleton to react appropriately to human motion intent. A genetic algorithm (GA) is utilized to determine the optimal sliding surface and the sliding control law to improve performance of SMC. The proposed control strategy (SMC_GA_CMAC) is compared with three other types of approaches, that is, conventional SMC without optimization, optimal SMC with GA (SMC_GA), and SMC with CMAC compensation (SMC_CMAC), all of which are employed to track the desired joint angular position which is deduced from Clinical Gait Analysis (CGA) data. Position tracking performance is investigated with cosimulation using ADAMS and MATLAB/SIMULINK in two cases, of which the first case is without disturbances while the second case is with a bounded disturbance. The cosimulation results show the effectiveness of the proposed control strategy which can be employed in similar exoskeleton systems.

  9. Robust Sliding Mode Control Based on GA Optimization and CMAC Compensation for Lower Limb Exoskeleton

    PubMed Central

    Long, Yi; Du, Zhi-jiang; Wang, Wei-dong; Dong, Wei

    2016-01-01

    A lower limb assistive exoskeleton is designed to help operators walk or carry payloads. The exoskeleton is required to shadow human motion intent accurately and compliantly to prevent incoordination. If the user's intention is estimated accurately, a precise position control strategy will improve collaboration between the user and the exoskeleton. In this paper, a hybrid position control scheme, combining sliding mode control (SMC) with a cerebellar model articulation controller (CMAC) neural network, is proposed to control the exoskeleton to react appropriately to human motion intent. A genetic algorithm (GA) is utilized to determine the optimal sliding surface and the sliding control law to improve performance of SMC. The proposed control strategy (SMC_GA_CMAC) is compared with three other types of approaches, that is, conventional SMC without optimization, optimal SMC with GA (SMC_GA), and SMC with CMAC compensation (SMC_CMAC), all of which are employed to track the desired joint angular position which is deduced from Clinical Gait Analysis (CGA) data. Position tracking performance is investigated with cosimulation using ADAMS and MATLAB/SIMULINK in two cases, of which the first case is without disturbances while the second case is with a bounded disturbance. The cosimulation results show the effectiveness of the proposed control strategy which can be employed in similar exoskeleton systems. PMID:27069353

  10. Dry Sliding Wear Behaviour of Flyash Reinforced ZA-27 Alloy Based Metal Matrix Composites

    NASA Astrophysics Data System (ADS)

    Sharma, S. C.; Krishna, M.; Bhattacharyya, D.

    In the present investigation, an attempt has been made to evaluate the wear rate of ZA-27 alloy composites reinforced with fly ash particles from 1 to 3 wt% in steps of 1 wt%. The compo-casting method has been used to fabricate the composites using Raichur fly ash of average size 3-5 microns. The wear specimens are tested under dry conditions using a pin-on-disc sliding wear testing machine with wear loads of 20-120 N in steps of 20 N, and the sliding distances in the range of 0.5 km to 2.5 km. The results indicate that the wear rate of the composites is less than that of the matrix alloy and it further decreases with the increase in fly ash content. However, the material loss in terms of wear rate and wear volume increases with the increase in load and sliding distance, both in the cases of composites and the matrix alloy. An increase in the applied load increases the wear severity by changing the wear mechanism from abrasion to particle-cracking induced delamination wear. It is found that with the increase in fly ash content, the wear resistance increases monotonically. The observations have been explained using scanning electron microscope (SEM) analysis of the worn surfaces of the composites.

  11. Ultrasound phase rotation beamforming on multi-core DSP.

    PubMed

    Ma, Jieming; Karadayi, Kerem; Ali, Murtaza; Kim, Yongmin

    2014-01-01

    Phase rotation beamforming (PRBF) is a commonly-used digital receive beamforming technique. However, due to its high computational requirement, it has traditionally been supported by hardwired architectures, e.g., application-specific integrated circuits (ASICs) or more recently field-programmable gate arrays (FPGAs). In this study, we investigated the feasibility of supporting software-based PRBF on a multi-core DSP. To alleviate the high computing requirement, the analog front-end (AFE) chips integrating quadrature demodulation in addition to analog-to-digital conversion were defined and used. With these new AFE chips, only delay alignment and phase rotation need to be performed by DSP, substantially reducing the computational load. We implemented the delay alignment and phase rotation modules on a Texas Instruments C6678 DSP with 8 cores. We found it takes 200 μs to beamform 2048 samples from 64 channels using 2 cores. With 4 cores, 20 million samples can be beamformed in one second. Therefore, ADC frequencies up to 40 MHz with 2:1 decimation in AFE chips or up to 20 MHz with no decimation can be supported as long as the ADC-to-DSP I/O requirement can be met. The remaining 4 cores can work on back-end processing tasks and applications, e.g., color Doppler or ultrasound elastography. One DSP being able to handle both beamforming and back-end processing could lead to low-power and low-cost ultrasound machines, benefiting ultrasound imaging in general, particularly portable ultrasound machines. Copyright © 2013 Elsevier B.V. All rights reserved.

  12. Observer-based robust finite time H∞ sliding mode control for Markovian switching systems with mode-dependent time-varying delay and incomplete transition rate.

    PubMed

    Gao, Lijun; Jiang, Xiaoxiao; Wang, Dandan

    2016-03-01

    This paper investigates the problem of robust finite time H∞ sliding mode control for a class of Markovian switching systems. The system is subjected to the mode-dependent time-varying delay, partly unknown transition rate and unmeasurable state. The main difficulty is that, a sliding mode surface cannot be designed based on the unknown transition rate and unmeasurable state directly. To overcome this obstacle, the set of modes is firstly divided into two subsets standing for known transition rate subset and unknown one, based on which a state observer is established. A component robust finite-time sliding mode controller is also designed to cope with the effect of partially unknown transition rate. It is illustrated that the reachability, finite-time stability, finite-time boundedness, finite-time H∞ state feedback stabilization of sliding mode dynamics can be ensured despite the unknown transition rate. Finally, the simulation results verify the effectiveness of robust finite time control problem.

  13. A swarm intelligence-based tuning method for the Sliding Mode Generalized Predictive Control.

    PubMed

    Oliveira, J B; Boaventura-Cunha, J; Moura Oliveira, P B; Freire, H

    2014-09-01

    This work presents an automatic tuning method for the discontinuous component of the Sliding Mode Generalized Predictive Controller (SMGPC) subject to constraints. The strategy employs Particle Swarm Optimization (PSO) to minimize a second aggregated cost function. The continuous component is obtained by the standard procedure, by Quadratic Programming (QP), thus yielding an online dual optimization scheme. Simulations and performance indexes for common process models in industry, such as nonminimum phase and time delayed systems, result in a better performance, improving robustness and tracking accuracy.

  14. High-speed and low-power electro-optical DSP coprocessor.

    PubMed

    Tamir, Dan E; Shaked, Natan T; Wilson, Peter J; Dolev, Shlomi

    2009-08-01

    A fast, power-efficient electro-optical vector-by-matrix multiplier (VMM) architecture is presented. Careful design of an electrical unit supporting high-speed data transfer enables this architecture to overcome bottlenecks encountered by previous VMM architectures. Based on the proposed architecture, we present an electro-optical digital signal processing (DSP) coprocessor that can achieve a significant speedup of 2-3 orders of magnitude over existing DSP technologies and execute more than 16 teraflops. We show that it is feasible to implement the system using off-the-shelf components, analyze the performance of the architecture with respect to primitive DSP operations, and detail the use of the new architecture for several DSP applications.

  15. STS-44 DSP satellite and IUS during preflight processing at Cape Canaveral

    NASA Technical Reports Server (NTRS)

    1991-01-01

    Overall view shows the Defense Support Program (DSP) satellite atop an inertial upper stage (IUS) during transfer operations in a processing facility at Cape Canaveral Air Force Station. Clean-suited technicians monitor the operations to prepare the 5,200-pound DSP satellite for transfer to Kennedy Space Center (KSC) Launch Complex (LC) Pad 39A. DSP solar paddles are in stowed position around the base of the satellite with the Infrared (IR) sensor hidden by a protective cover at the top of the satellite. DSP, a surveillance satellite that can detect missle and space launches as well as nuclear detonations will be boosted into geosynchronous orbit by the IUS during the STS-44 mission. View provided by the Kennedy Space Center (KSC) with alternate number KSC-91PC-1747.

  16. Shack-Hartmann sensor based optical quality testing of whole slide imaging systems for digital pathology

    NASA Astrophysics Data System (ADS)

    Shakeri, S. M.; Hulsken, Bas; van Vliet, Lucas J.; Stallinga, Sjoerd

    2015-03-01

    Whole Slide Imaging (WSI) systems are used in the emerging field of digital pathology for capturing high-resolution images of tissue slides at high throughput. We present a technique to measure the optical aberrations of WSI systems using a Shack-Hartmann wavefront sensor as a function of field position. The resulting full-field aberration maps for the lowest order astigmatism and coma are analyzed using nodal aberration theory. According to this theory two coefficients describe the astigmatism and coma inherent to the optical design and another six coefficients are needed to describe the cumulative effects of all possible misalignments on astigmatism and coma. The nodal aberration theory appears to fit well to the experimental data. We have measured and analyzed the full-field aberration maps for two different objective lens-tube lens assemblies and found that only the optical design related astigmatism coefficient differed substantially between the two cases, but in agreement with expectations. We have also studied full-field aberration maps for intentional decenter and tilt and found that these affect the misalignment coefficient for constant coma (decenter) and the misalignment coefficient for linear astigmatism (tilt), while keeping all other nodal aberration theory coefficients constant.

  17. Intermittent chaos and sliding window symbol sequence statistics-based early fault diagnosis for hydraulic pump on hydraulic tube tester

    NASA Astrophysics Data System (ADS)

    Zhao, Zhen; Jia, Mingxing; Wang, Fuli; Wang, Shu

    2009-07-01

    To ensure the safety, continuity of production, make a reasonable maintenance plan, save the cost of maintenance for hydraulic tube tester, it is needed to quickly identify an assignable cause of a fault. This paper is concerned with early fault diagnosis of hydraulic pump which are the heart of hydraulic tube tester. Considering that the signal of the hydraulic pump early fault is a periodic weak signal, an intermittent chaos, sliding window symbol sequence statistics-based method is proposed to detect the early fault of one single piston loose shoes of hydraulic pump on a hydraulic tube tester. The approach presented is based on the insight that the phase transition of chaos oscillator, for example, the Duffing oscillator, is very sensitive to a periodic weak signal having little angular frequency difference with the referential signal of the oscillator. While observing the intermittent chaos phenomenon through figure is not easy for computer, a sliding window symbol sequence statistics is developed to realize real-time computer observation of this phenomenon. Rather more, this paper takes a trick to decreasing the computational complexity of the sliding window symbol sequence statistics method, also analyzes the influences of different window size, depths of the symbol tree on the information entropy. At last, a control limit is introduced to realize automatic early fault alarm. The resultant approach is experimented with data simulated from an AMESim model of hydraulic tube tester. The results indicate that the proposed approach is capable of detecting the signal of hydraulic pump early fault on hydraulic tube tester.

  18. Switching sliding mode force tracking control of piezoelectric-hydraulic pump-based friction element actuation systems for automotive transmissions

    NASA Astrophysics Data System (ADS)

    Kim, Gi-Woo; Wang, K. W.

    2009-08-01

    In this study, a nonlinear sliding-mode controller is designed for force tracking of a piezoelectric-hydraulic pump (PHP)-based actuation system, which is developed to replace the current electro-hydraulic actuation systems for automatic transmission (AT) friction elements, such as band brakes or clutches. By utilizing the PHP, one can eliminate the various hydraulic components (oil pump, regulating valve and control valve) in current ATs and achieve a simpler configuration with more efficient operation. With the derived governing equation of motion of the PHP-based actuation system integrated with the friction element (band brake), a switching control law is synthesized based on the sliding-mode theory. To evaluate the effectiveness of the proposed control law, its force tracking performance for the engagement of a friction element during an AT 1\\to 2 up-shift is examined experimentally. It is shown that one can successfully track the desired force trajectory for AT shift control with small tracking error. This study demonstrates the potential of the PHP as a new controllable actuation system for AT friction elements.

  19. Sliding Wear and Fretting Wear of DLC-Based, Functionally Graded Nanocomposite Coatings

    NASA Technical Reports Server (NTRS)

    Miyoshi, K.; Pohlchuck, B.; Street, Kenneth W.; Zabinski, J. S.; Sanders, J. H.; Voevodin, A. a.; Wu, R. L. C.

    1999-01-01

    Improving the tribological functionality of diamondlike carbon (DLC) films--developing, good wear resistance, low friction, and high load-carrying capacity-was the aim of this investigation. Nanocomposite coatings consisting of an amorphous DLC (a-DLC) top layer and a functionally graded titanium-titanium carbon-diamondlike carbon (Ti-Ti(sub x) C(sub y)-DLC) underlayer were produced on AISI 440C stainless steel substrates by the hybrid technique of magnetron sputtering and pulsed-laser deposition. The resultant DLC films were characterized by Raman spectroscopy, scanning electron microscopy, and surface profilometry. Two types of wear experiment were conducted in this investioation: sliding friction experiments and fretting wear experiments. Unidirectional ball-on-disk sliding friction experiments were conducted to examine the wear behavior of an a-DLC/Ti-Ti(sub x) C(sub y)-DLC-coated AISI 440C stainless steel disk in sliding contact with a 6-mm-diameter AISI 440C stainless steel ball in ultrahigh vacuum, dry nitrogen, and humid air. Although the wear rates for both the coating and ball were low in all three environments, the humid air and dry nitrogen caused mild wear with burnishing, in the a-DLC top layer, and the ultrahigh vacuum caused relatively severe wear with brittle fracture in both the a-DLC top layer and the Ti-Ti(sub x) C(sub y)-DLC underlayer. For reference, amorphous hydrogenated carbon (H-DLC) films produced on a-DLC/Ti-Ti(sub x) C(sub y)-DLC nanocomposite coatings by using an ion beam were also examined in the same manner. The H-DLC films markedly reduced friction even in ultrahigh vacuum without sacrificing wear resistance. The H-DLC films behaved much like the a-DLC/Ti-Ti(sub x) C(sub y)-DLC nanocomposite coating in dry nitrogen and humid air, presenting low friction and low wear. Fretting wear experiments were conducted in humid air (approximately 50% relative humidity) at a frequency of 80 Hz and an amplitude of 75 micron on an a

  20. An energy-efficient SIMD DSP with multiple VLIW configurations and an advanced memory access unit for LTE-A modem LSIs

    NASA Astrophysics Data System (ADS)

    Tomono, Mitsuru; Ito, Makiko; Nomura, Yoshitaka; Mouri, Makoto; Hirose, Yoshio

    2015-12-01

    Energy efficiency is the most important factor in the design of wireless modem LSIs for mobile handset systems. We have developed an energy-efficient SIMD DSP for LTE-A modem LSIs. Our DSP has mainly two hardware features in order to reduce energy consumption. The first one is multiple VLIW configurations to minimize accesses to instruction memories. The second one is an advanced memory access unit to realize complex memory accesses required for wireless baseband processing. With these features, performance of our DSP is about 1.7 times faster than a base DSP on average for standard LTE-A Libraries. Our DSP achieves about 20% improvement in energy efficiency compared to a base DSP for LTE-A modem LSIs.

  1. An improved sliding mode control method for omnidirectional mobile robots based on motion characteristics

    NASA Astrophysics Data System (ADS)

    Leng, Chuntao; Cao, Qixin; Lo, Charles

    2010-01-01

    An improved sliding mode control (SMC) method for omni-directional mobile robots (OMRs) is proposed in this paper. Due to the motion characteristics of OMRs, the driving torque acting on each axis while the robot moves in different directions is distinct. Accordingly, a novel concept of anisotropy characteristics for OMRs is proposed here. In order to achieve a coordinated motion in a multi-axis system such as an OMR, the anisotropy characteristics are introduced into SMC system to coordinate the driving torque. The improved motion control method can guarantee that each driving wheel will reach the target speed with proper driving torque. Owing to the advantage of SMC, the control system of OMRs is insensitive to parametric vibration and external disturbances. To validate the performance of the improved motion control method, experiments have been carried out.

  2. An improved sliding mode control method for omnidirectional mobile robots based on motion characteristics

    NASA Astrophysics Data System (ADS)

    Leng, Chuntao; Cao, Qixin; Lo, Charles

    2009-12-01

    An improved sliding mode control (SMC) method for omni-directional mobile robots (OMRs) is proposed in this paper. Due to the motion characteristics of OMRs, the driving torque acting on each axis while the robot moves in different directions is distinct. Accordingly, a novel concept of anisotropy characteristics for OMRs is proposed here. In order to achieve a coordinated motion in a multi-axis system such as an OMR, the anisotropy characteristics are introduced into SMC system to coordinate the driving torque. The improved motion control method can guarantee that each driving wheel will reach the target speed with proper driving torque. Owing to the advantage of SMC, the control system of OMRs is insensitive to parametric vibration and external disturbances. To validate the performance of the improved motion control method, experiments have been carried out.

  3. A novel approach for state of charge estimation based on adaptive switching gain sliding mode observer in electric vehicles

    NASA Astrophysics Data System (ADS)

    Chen, Xiaopeng; Shen, Weixiang; Cao, Zhenwei; Kapoor, Ajay

    2014-01-01

    In this paper, a novel approach for battery state of charge (SOC) estimation in electric vehicles (EVs) based on an adaptive switching gain sliding mode observer (ASGSMO) has been presented. To design the ASGSMO for the SOC estimation, the state equations based on a battery equivalent circuit model (BECM) are derived to represent dynamic behaviours of a battery. Comparing with a conventional sliding mode observer, the ASGSMO has a capability of minimising chattering levels in the SOC estimation by using the self-adjusted switching gain while maintaining the characteristics of being able to compensate modelling errors caused by the parameter variations of the BECM. Lyapunov stability theory is adopted to prove the error convergence of the ASGSMO for the SOC estimation. The lithium-polymer battery (LiPB) is utilised to conduct experiments for determining the parameters of the BECM and verifying the effectiveness of the proposed ASGSMO in various discharge current profiles including EV driving conditions in both city and suburban.

  4. Speed tracking control of pneumatic motor servo systems using observation-based adaptive dynamic sliding-mode control

    NASA Astrophysics Data System (ADS)

    Chen, Syuan-Yi; Gong, Sheng-Sian

    2017-09-01

    This study aims to develop an adaptive high-precision control system for controlling the speed of a vane-type air motor (VAM) pneumatic servo system. In practice, the rotor speed of a VAM depends on the input mass air flow, which can be controlled by the effective orifice area (EOA) of an electronic throttle valve (ETV). As the control variable of a second-order pneumatic system is the integral of the EOA, an observation-based adaptive dynamic sliding-mode control (ADSMC) system is proposed to derive the differential of the control variable, namely, the EOA control signal. In the ADSMC system, a proportional-integral-derivative fuzzy neural network (PIDFNN) observer is used to achieve an ideal dynamic sliding-mode control (DSMC), and a supervisor compensator is designed to eliminate the approximation error. As a result, the ADSMC incorporates the robustness of a DSMC and the online learning ability of a PIDFNN. To ensure the convergence of the tracking error, a Lyapunov-based analytical method is employed to obtain the adaptive algorithms required to tune the control parameters of the online ADSMC system. Finally, our experimental results demonstrate the precision and robustness of the ADSMC system for highly nonlinear and time-varying VAM pneumatic servo systems.

  5. The Storegga Slide, mid-Norwegian: architecture and slide processes

    NASA Astrophysics Data System (ADS)

    Haflidason, H.; Sejrup, H. P.; Nygaard, A.; Hjelstuen, B. O.; Bryn, P.; Lien, R.; Berg, K.; Masson, D.

    2003-04-01

    The mid-Norwegian continental margin has been exposed to a number of large-scale submarine landslides during the last ca. 1 Ma. The slide activity seems to be contemporaneous with the onset of the large Scandinavian glaciations. The geometry and evolution of the margin have been influenced by long lasting processes creating large-scale morphological forms such as the depression in the Storegga Slide basin, flanked by the highs of the North Sea Fan to the south and the Vøring Plateau to the north. The Storegga Slide/North Sea Fan area is characterized by the largest and most frequent occurring landslides on the Norwegian continental margin. The last mega slide is the exposed Storegga Slide dated to about 7.300 14C yrs BP, or about 8200 cal yrs BP. The total area influenced by this slide event is about 90.000 km^2, and a preliminary estimate of the slide volume is ca. 3.300 km^3. A large amount of acoustic data (TOBI side scan and multibeam echo-sounder), and more than 100 shallow sediment cores have been collected inside the Storegga Slide area to develop a morphological model. Detailed studies on the geometry, chronology and genesis of the sediments deposited during the last glacial-interglacial cycles have been based on a 2D/3D seismic database and 12 shallow borings. The detailed mapping of the slide surface morphology has contributed to a better understanding of the complexity of the processes and development of the Storegga Slide failure. The exposed Storegga Slide is considered to be an excellent analogue to many of the buried large slides identified in this area and the major effort on studying this last large slide failure have contributed to a better understanding of the long-term instability in the area. A summary of the stratigraphical and morphological analyses of the Storegga Slide area and what implication it has on our understanding of the margin instability in this area will be presented.

  6. [Multi-DSP parallel processing technique of hyperspectral RX anomaly detection].

    PubMed

    Guo, Wen-Ji; Zeng, Xiao-Ru; Zhao, Bao-Wei; Ming, Xing; Zhang, Gui-Feng; Lü, Qun-Bo

    2014-05-01

    To satisfy the requirement of high speed, real-time and mass data storage etc. for RX anomaly detection of hyperspectral image data, the present paper proposes a solution of multi-DSP parallel processing system for hyperspectral image based on CPCI Express standard bus architecture. Hardware topological architecture of the system combines the tight coupling of four DSPs sharing data bus and memory unit with the interconnection of Link ports. On this hardware platform, by assigning parallel processing task for each DSP in consideration of the spectrum RX anomaly detection algorithm and the feature of 3D data in the spectral image, a 4DSP parallel processing technique which computes and solves the mean matrix and covariance matrix of the whole image by spatially partitioning the image is proposed. The experiment result shows that, in the case of equivalent detective effect, it can reach the time efficiency 4 times higher than single DSP process with the 4-DSP parallel processing technique of RX anomaly detection algorithm proposed by this paper, which makes a breakthrough in the constraints to the huge data image processing of DSP's internal storage capacity, meanwhile well meeting the demands of the spectral data in real-time processing.

  7. Posture and Vibration Control Based on Virtual Suspension Model Using Sliding Mode Control for Six-Legged Walking Robot

    NASA Astrophysics Data System (ADS)

    Huang, Qingjiu; Fukuhara, Yasuyuki; Chen, Xuedong

    In this paper, we proposed a robust control method based on the virtual suspension model for keeping the posture stability and decreasing the tiny vibration of the robot body when it is walking on irregular terrain. Firstly, we developed a six-legged walking robot for this study based on stable theory of wave gaits and CAD dynamic model. Secondly, in order to keep the posture stability of body when robot walks, we designed a virtual suspension model with one degree of freedom, which has virtual spring and damper, for the direction of the center of gravity, the pitch angle, and the roll angle of body respectively. And then, in order to decrease the tiny vibration of body when robot walks, we proposed an active suspension control by using sliding mode control based on a virtual suspension model. These proposed methods are discussed using the walking experimental results of the developed six-legged walking robot.

  8. Free-flying dynamics and control of an astronaut assistant robot based on fuzzy sliding mode algorithm

    NASA Astrophysics Data System (ADS)

    Gao, Qing; Liu, Jinguo; Tian, Tongtong; Li, Yangmin

    2017-09-01

    Space robots can perform some tasks in harsh environment as assistants of astronauts or substitutions of astronauts. Taking the limited working time and the arduous task of the astronauts in the space station into account, an astronaut assistant robot (AAR-2) applied in the space station is proposed and designed in this paper. The AAR-2 is achieved with some improvements on the basis of AAR-1 which was designed before. It can exploit its position and attitude sensors and control system to free flight or hover in the space cabin. And it also has a definite environmental awareness and artificial intelligence to complete some specified tasks under the control of astronauts or autonomously. In this paper, it mainly analyzes and controls the 6-DOF motion of the AAR-2. Firstly, the system configuration of AAR-2 is specifically described, and the movement principles are analyzed. Secondly, according to the physical model of the AAR-2, the Newton - Euler equation is applied in the preparation of space dynamics model of 6-DOF motion. Then, according to the mathematical model's characteristics which are nonlinear and strong coupling, a dual closed loop position and attitude controller based on fuzzy sliding mode control is proposed and designed. Finally, simulation experiments are appropriate to provide for AAR-2 control system by using Matlab/Simulink. From the simulation results it can be observed that the designed fuzzy sliding mode controller can control the 6-DOF motion of AAR-2 quickly and precisely.

  9. CNN based Malaria Diagnosis from Focus-stack of Blood Smear Images Acquired using Custom-built Slide Scanner.

    PubMed

    Gopakumar, G; Swetha, M; Gorthi, Sai Siva; Sai Subrahmanyam, Gorthi R K

    2017-08-29

    This paper introduces a focus stacking based approach for automated quantitative detection of Plasmodium falciparum malaria from blood smear. For the detection, a custom designed convolutional neural network (CNN) operating on focus stack of images is used. The cell counting problem is addressed as the segmentation problem and we propose a two level segmentation strategy. Use of CNN operating on focus stack for the detection of malaria is first of its kind, and it not only improved the detection accuracy (both in terms of sensitivity (97.06%) and specificity (98.50%)) but also favoured the processing on cell patches and avoided the need for hand-engineered features. The slide images are acquired with a custom-built portable slide scanner made from low-cost, off-the-shelf components and is suitable for Point-of-Care Diagnostics. The proposed approach of employing sophisticated algorithmic processing together with inexpensive instrumentation can potentially benefit clinicians to enable malaria diagnosis. This article is protected by copyright. All rights reserved.

  10. Alcohol-based quorum sensing plays a role in adhesion and sliding motility of the yeast Debaryomyces hansenii.

    PubMed

    Gori, Klaus; Knudsen, Peter B; Nielsen, Kristian F; Arneborg, Nils; Jespersen, Lene

    2011-12-01

    The yeast Debaryomyces hansenii was investigated for its production of alcohol-based quorum sensing (QS) molecules including the aromatic alcohols phenylethanol, tyrosol, tryptophol and the aliphatic alcohol farnesol. Debaryomyces hansenii produced phenylethanol and tyrosol, which were primarily detected from the end of exponential phase indicating that they are potential QS molecules in D. hansenii as previously shown for other yeast species. Yields of phenylethanol and tyrosol produced by D. hansenii were, however, lower than those produced by Candida albicans and Saccharomyces cerevisiae and varied with growth conditions such as the availability of aromatic amino acids, ammonium sulphate, NaCl, pH and temperature. Tryptophol was only produced in the presence of tryptophane, whereas farnesol in general was not detectable. Especially, the type strain of D. hansenii (CBS767) had good adhesion and sliding motility abilities, which seemed to be related to a higher hydrophobicity of the cell surface of D. hansenii (CBS767) rather than the ability to form pseudomycelium. Addition of phenylethanol, tyrosol, tryptophol and farnesol was found to influence both adhesion and sliding motility of D. hansenii. © 2011 Federation of European Microbiological Societies. Published by Blackwell Publishing Ltd. All rights reserved.

  11. Implementation of a sliding-mode-based position sensorless drive for high-speed micro permanent-magnet synchronous motors.

    PubMed

    Chi, Wen-Chun; Cheng, Ming-Yang

    2014-03-01

    Due to issues such as limited space, it is difficult if it is not impossible to employ a position sensor in the drive control of high-speed micro PMSMs. In order to alleviate this problem, this paper analyzes and implements a simple and robust position sensorless field-oriented control method of high-speed micro PMSMs based on the sliding-mode observer. In particular, the angular position and velocity of the rotor of the high-speed micro PMSM are estimated using the sliding-mode observer. This observer is able to accurately estimate rotor position in the low speed region and guarantee fast convergence of the observer in the high speed region. The proposed position sensorless control method is suitable for electric dental handpiece motor drives where a wide speed range operation is essential. The proposed sensorless FOC method is implemented using a cost-effective 16-bit microcontroller and tested in a prototype electric dental handpiece motor. Several experiments are performed to verify the effectiveness of the proposed method.

  12. The Vaiont Slide. A Geotechnical Analysis Based on New Geologic Observations of the Failure Surface. Volume 1. Main Text

    DTIC Science & Technology

    1985-06-01

    alone was approximately 12 percent, while the reduction caused by rainfall or snow- melt ranged from 10 to 18 percent. Correlations made between... rainfall 77 Uniform behavior of the si ide 79 PART IX: KINEMATIC CHARACTERISTICS OF THE VAIONT SLIDE 80 Introduction 80 Mechanisms Investigated... induced fluid pressures 43 Vaiont Slide, results of the heat generation analysis Figures in Appendices* Bl Subdivision of slide into slices B2

  13. Video analysis of sliding chains: A dynamic model based on variable-mass systems

    NASA Astrophysics Data System (ADS)

    Moreno, R.; Page, A.; Riera, J.; Hueso, J. L.

    2015-06-01

    This paper presents an experimental study of the dynamics of a chain sliding off of a table, using video analysis to test a theoretical model. The model consists of two variable-mass subsystems, with friction between the chain and the table and assumes that all links move at the same speed. In order to check the model, the chain position x(t) is obtained using video analysis. The smoothed function x(t) and its derivatives v(t) and a(t) are numerically computed using a local regression algorithm. In this way, the differential equation governing the motion can be directly tested, instead of comparing the position with the solution of the differential equation. Our procedure is very sensitive to deviations between the model and reality, so we can detect the point at which the chain ceases to be in tension and the model is no longer valid. This experiment shows students the limitations of simplified models and offers an opportunity to assess a model's range of validity.

  14. Colorful Superamphiphobic Coatings with Low Sliding Angles and High Durability Based on Natural Nanorods.

    PubMed

    Dong, Jie; Wang, Qin; Zhang, Yujie; Zhu, Zhaoqi; Xu, Xianghong; Zhang, Junping; Wang, Aiqin

    2017-01-18

    Superamphiphobic coatings with low sliding angles (SAs) and high durability are very attractive in academic and industrial areas but are very challenging to invent. Here, inspired by Maya Blue, we report for the first time colorful superamphiphobic coatings with low SAs and high durability by the combination of natural palygorskite (PAL) nanorods and organosilanes. The coatings were characterized using a wide range of electron microscopy and other analytical techniques. Different from the previously reported methods, the micro/nanostructure of the superamphiphobic coatings were constructed by using the abundant natural PAL nanorods as the building blocks. Superamphiphobicity of the coatings depends on surface morphology and chemical composition of the coatings, which can be regulated by the concentrations of PAL and organosilanes. The colorful superamphiphobic coatings feature high contact angles and low SAs for various liquids, including water and n-decane. The coatings also showed high mechanical, environmental, chemical, and thermal durability even under harsh conditions. Moreover, the coatings in different colors with comparable superamphiphobicity and durability can be prepared using different cationic dyes applied onto various substrates via the same approach. The colorful superamphiphobic coatings with low SAs and high durability may be useful in various fields, e.g., anticreeping of oils and restoration of cultural relics.

  15. A pipeline for neuron reconstruction based on spatial sliding volume filter seeding.

    PubMed

    Sui, Dong; Wang, Kuanquan; Chae, Jinseok; Zhang, Yue; Zhang, Henggui

    2014-01-01

    Neuron's shape and dendritic architecture are important for biosignal transduction in neuron networks. And the anatomy architecture reconstruction of neuron cell is one of the foremost challenges and important issues in neuroscience. Accurate reconstruction results can facilitate the subsequent neuron system simulation. With the development of confocal microscopy technology, researchers can scan neurons at submicron resolution for experiments. These make the reconstruction of complex dendritic trees become more feasible; however, it is still a tedious, time consuming, and labor intensity task. For decades, computer aided methods have been playing an important role in this task, but none of the prevalent algorithms can reconstruct full anatomy structure automatically. All of these make it essential for developing new method for reconstruction. This paper proposes a pipeline with a novel seeding method for reconstructing neuron structures from 3D microscopy images stacks. The pipeline is initialized with a set of seeds detected by sliding volume filter (SVF), and then the open curve snake is applied to the detected seeds for reconstructing the full structure of neuron cells. The experimental results demonstrate that the proposed pipeline exhibits excellent performance in terms of accuracy compared with traditional method, which is clearly a benefit for 3D neuron detection and reconstruction.

  16. Sliding window-based region of interest extraction for finger vein images.

    PubMed

    Yang, Lu; Yang, Gongping; Yin, Yilong; Xiao, Rongyang

    2013-03-18

    Region of Interest (ROI) extraction is a crucial step in an automatic finger vein recognition system. The aim of ROI extraction is to decide which part of the image is suitable for finger vein feature extraction. This paper proposes a finger vein ROI extraction method which is robust to finger displacement and rotation. First, we determine the middle line of the finger, which will be used to correct the image skew. Then, a sliding window is used to detect the phalangeal joints and further to ascertain the height of ROI. Last, for the corrective image with certain height, we will obtain the ROI by using the internal tangents of finger edges as the left and right boundary. The experimental results show that the proposed method can extract ROI more accurately and effectively compared with other methods, and thus improve the performance of finger vein identification system. Besides, to acquire the high quality finger vein image during the capture process, we propose eight criteria for finger vein capture from different aspects and these criteria should be helpful to some extent for finger vein capture.

  17. LQ optimal and reaching law-based sliding modes for inventory management systems

    NASA Astrophysics Data System (ADS)

    Ignaciuk, Przemysław; Bartoszewicz, Andrzej

    2012-01-01

    In this article, the theory of discrete sliding-mode control is used to design new supply strategies for periodic-review inventory systems. In the considered systems, the stock used to fulfil an unknown, time-varying demand can be replenished from a single supply source or from multiple suppliers procuring orders with different delays. The proposed strategies guarantee that demand is always entirely satisfied from the on-hand stock (yielding the maximum service level), and the warehouse capacity is not exceeded (which eliminates the cost of emergency storage). In contrast to the classical, stochastic approaches, in this article, we focus on optimising the inventory system dynamics. The parameters of the first control strategy are selected by minimising a quadratic cost functional. Next, it is shown how the system dynamical performance can be improved by applying the concept of a reaching law with the appropriately adjusted reaching phase. The stable, nonoscillatory behaviour of the closed-loop system is demonstrated and the properties of the designed controllers are discussed and strictly proved.

  18. Segmentation of vessel structures in serial whole slide sections using region-based context features

    NASA Astrophysics Data System (ADS)

    Schwier, Michael; Hahn, Horst K.; Dahmen, Uta; Dirsch, Olaf

    2016-03-01

    We present a method for the automatic segmentation of vascular structures in stacks of serial sections. It was initially motivated within the Virtual Liver Network research project that aims at creating a multi-scale virtual model of the liver. For this the vascular systems of several murine livers under different conditions need to be analyzed. To get highly detailed datasets, stacks of serial sections of the whole organs are prepared. Due to the huge amount of image data an automatic approach for segmenting the vessels is required. After registering the slides with an established method we use a set of Random Forest classifiers to distinguish vessels from tissue. Instead of a pixel-wise approach we perform the classification on small regions. This allows us to use more meaningful features. Besides basic intensity and texture features we introduce the concept of context features, which allow the classifiers to also consider the neighborhood of a region. Classification is performed in two stages. In the second stage the previous classification result of a region and its neighbors is used to refine the decision for a particular region. The context features and two stage classification process make our method very successful. It can handle different stainings and also detect vessels in which residue like blood cells remained. The specificity reaches 95%-99% for pure tissue, depending on staining and zoom level. Only in the direct vicinity of vessels the specificity declines to 88%-96%. The sensitivity rates reach between 89% and 98%.

  19. Vision-based stabilization of nonholonomic mobile robots by integrating sliding-mode control and adaptive approach

    NASA Astrophysics Data System (ADS)

    Cao, Zhengcai; Yin, Longjie; Fu, Yili

    2013-01-01

    Vision-based pose stabilization of nonholonomic mobile robots has received extensive attention. At present, most of the solutions of the problem do not take the robot dynamics into account in the controller design, so that these controllers are difficult to realize satisfactory control in practical application. Besides, many of the approaches suffer from the initial speed and torque jump which are not practical in the real world. Considering the kinematics and dynamics, a two-stage visual controller for solving the stabilization problem of a mobile robot is presented, applying the integration of adaptive control, sliding-mode control, and neural dynamics. In the first stage, an adaptive kinematic stabilization controller utilized to generate the command of velocity is developed based on Lyapunov theory. In the second stage, adopting the sliding-mode control approach, a dynamic controller with a variable speed function used to reduce the chattering is designed, which is utilized to generate the command of torque to make the actual velocity of the mobile robot asymptotically reach the desired velocity. Furthermore, to handle the speed and torque jump problems, the neural dynamics model is integrated into the above mentioned controllers. The stability of the proposed control system is analyzed by using Lyapunov theory. Finally, the simulation of the control law is implemented in perturbed case, and the results show that the control scheme can solve the stabilization problem effectively. The proposed control law can solve the speed and torque jump problems, overcome external disturbances, and provide a new solution for the vision-based stabilization of the mobile robot.

  20. Fault-Tolerant, Radiation-Hard DSP

    NASA Technical Reports Server (NTRS)

    Czajkowski, David

    2011-01-01

    Commercial digital signal processors (DSPs) for use in high-speed satellite computers are challenged by the damaging effects of space radiation, mainly single event upsets (SEUs) and single event functional interrupts (SEFIs). Innovations have been developed for mitigating the effects of SEUs and SEFIs, enabling the use of very-highspeed commercial DSPs with improved SEU tolerances. Time-triple modular redundancy (TTMR) is a method of applying traditional triple modular redundancy on a single processor, exploiting the VLIW (very long instruction word) class of parallel processors. TTMR improves SEU rates substantially. SEFIs are solved by a SEFI-hardened core circuit, external to the microprocessor. It monitors the health of the processor, and if a SEFI occurs, forces the processor to return to performance through a series of escalating events. TTMR and hardened-core solutions were developed for both DSPs and reconfigurable field-programmable gate arrays (FPGAs). This includes advancement of TTMR algorithms for DSPs and reconfigurable FPGAs, plus a rad-hard, hardened-core integrated circuit that services both the DSP and FPGA. Additionally, a combined DSP and FPGA board architecture was fully developed into a rad-hard engineering product. This technology enables use of commercial off-the-shelf (COTS) DSPs in computers for satellite and other space applications, allowing rapid deployment at a much lower cost. Traditional rad-hard space computers are very expensive and typically have long lead times. These computers are either based on traditional rad-hard processors, which have extremely low computational performance, or triple modular redundant (TMR) FPGA arrays, which suffer from power and complexity issues. Even more frustrating is that the TMR arrays of FPGAs require a fixed, external rad-hard voting element, thereby causing them to lose much of their reconfiguration capability and in some cases significant speed reduction. The benefits of COTS high

  1. T-Slide Linear Actuators

    NASA Technical Reports Server (NTRS)

    Vranish, John

    2009-01-01

    -the-shelf, electric servomotor, a motor angle resolution sensor (typically an encoder or resolver), and microprocessor-based intelligent software. In applications requiring precision positioning, it may be necessary to add strain gauges to the T-slide housing. Existing sensory- interactive motion control art will work for T slides. For open-loop positioning, a stepping motor emulation technique can be used.

  2. Site Specificity of Cleavage of DSP-PP by BMP1

    PubMed Central

    Yang, Robert T.; Lim, Glendale L.; Yee, Colin T.; Fuller, Robert S.; Ritchie, Helena H.

    2015-01-01

    Bone morphogenic protein 1 (BMP1), a metalloproteinase, is known to cleave a wide variety of extracellular matrix proteins, suggesting that a consensus substrate cleavage amino acid sequence might exist. However, while such a consensus sequence has been proposed based on P4 to P4′ (i.e., the four amino acids flanking either side of the BMP1 cleavage site; P4P3P2P1|P1′P2′P3′P4′) sequence homologies between two BMP1 substrates, dentin matrix protein 1 and dentin sialoprotein phosphophoryn (DSP-PP) (i.e., xMQx | DDP), no direct testing has so far been attempted. Using an Sf9 cell expression system, we have been able to produce large amounts of uncleaved DSP-PP,. Point mutations introduced into this recombinant DSP-PP were then tested for their affects on DSP-PP cleavage by either Sf9 endogenous tolloid-related protein 1 (TLR-1) or by its human homolog, BMP1. Here we have measured DSP-PP cleavage efficiencies after modifications based on P4-P4′ sequence comparisons with dentin matrix protein 1, as well as for prolysyl oxidase and chordin, two other BMP1 substrates. Our results demonstrate that any mutations within or outside of the DSP-PP P4 to P4′ cleavage site can block, impair or accelerate DSP-PP cleavage, and suggest that its BMP1 cleavage site is highly conserved in order to regulate its cleavage efficiency, possibly with additional assistance from its conserved exosites. Thus, BMP1 cleavage cannot be based on a consensus substrate cleavage site. PMID:25158199

  3. Sensorless control of ship propulsion interior permanent magnet synchronous motor based on a new sliding mode observer.

    PubMed

    Ren, Jun-Jie; Liu, Yan-Cheng; Wang, Ning; Liu, Si-Yuan

    2015-01-01

    This paper proposes a sensorless speed control strategy for ship propulsion interior permanent magnet synchronous motor (IPMSM) based on a new sliding-mode observer (SMO). In the SMO the low-pass filter and the method of arc-tangent calculation of extended electromotive force (EMF) or phase-locked loop (PLL) technique are not used. The calculation of the rotor speed is deduced from the Lyapunov function stability analysis. In order to reduce system chattering, sigmoid functions with switching gains being adaptively updated by fuzzy logic systems are innovatively incorporated into the SMO. Finally, simulation results for a 4.088 MW ship propulsion IPMSM and experimental results from a 7.5 kW IPMSM drive are provided to verify the effectiveness of the proposed SMO method.

  4. Implementation of a High-Speed FPGA and DSP Based FFT Processor for Improving Strain Demodulation Performance in a Fiber-Optic-Based Sensing System

    NASA Technical Reports Server (NTRS)

    Farley, Douglas L.

    2005-01-01

    NASA's Aviation Safety and Security Program is pursuing research in on-board Structural Health Management (SHM) technologies for purposes of reducing or eliminating aircraft accidents due to system and component failures. Under this program, NASA Langley Research Center (LaRC) is developing a strain-based structural health-monitoring concept that incorporates a fiber optic-based measuring system for acquiring strain values. This fiber optic-based measuring system provides for the distribution of thousands of strain sensors embedded in a network of fiber optic cables. The resolution of strain value at each discrete sensor point requires a computationally demanding data reduction software process that, when hosted on a conventional processor, is not suitable for near real-time measurement. This report describes the development and integration of an alternative computing environment using dedicated computing hardware for performing the data reduction. Performance comparison between the existing and the hardware-based system is presented.

  5. DSP acceleration using cache logic FPGAs

    NASA Astrophysics Data System (ADS)

    Rosenberg, Joel

    1995-09-01

    Stand-alone digital signal processors (DSPs) support many on-chip functions and are highly optimized for the demands of high-speed computing. The problem associated with this functional optimization is that the increase in performance comes at the expense of flexibility. To make the DSP general purpose enough for a wide variety of applications, a custom ASIC must be used to achieve the desired performance. DSPs and ASICs are not able to easily adapt on-the-fly to different algorithms. Even DSPs that can do this don't match the high level of optimization provided by an ASIC. Recent developments in FPGA design tools enable system designers to develop in-system reconfigurable adaptive DSP hardware. Designed to exploit register rich, dynamically recongigurable field programmable gate arrays, high speed custom DSP functions can be created and implemented, resulting in significantly improved performance for compute-intensive applications, including graphics and image processing, telecommunications, networking and instrumentation.

  6. SPROC: A multiple-processor DSP IC

    NASA Technical Reports Server (NTRS)

    Davis, R.

    1991-01-01

    A large, single-chip, multiple-processor, digital signal processing (DSP) integrated circuit (IC) fabricated in HP-Cmos34 is presented. The innovative architecture is best suited for analog and real-time systems characterized by both parallel signal data flows and concurrent logic processing. The IC is supported by a powerful development system that transforms graphical signal flow graphs into production-ready systems in minutes. Automatic compiler partitioning of tasks among four on-chip processors gives the IC the signal processing power of several conventional DSP chips.

  7. Adaptive Neuro-Fuzzy Control of a Spherical Rolling Robot Using Sliding-Mode-Control-Theory-Based Online Learning Algorithm.

    PubMed

    Kayacan, Erkan; Kayacan, Erdal; Ramon, Herman; Saeys, Wouter

    2013-02-01

    As a model is only an abstraction of the real system, unmodeled dynamics, parameter variations, and disturbances can result in poor performance of a conventional controller based on this model. In such cases, a conventional controller cannot remain well tuned. This paper presents the control of a spherical rolling robot by using an adaptive neuro-fuzzy controller in combination with a sliding-mode control (SMC)-theory-based learning algorithm. The proposed control structure consists of a neuro-fuzzy network and a conventional controller which is used to guarantee the asymptotic stability of the system in a compact space. The parameter updating rules of the neuro-fuzzy system using SMC theory are derived, and the stability of the learning is proven using a Lyapunov function. The simulation results show that the control scheme with the proposed SMC-theory-based learning algorithm is able to not only eliminate the steady-state error but also improve the transient response performance of the spherical rolling robot without knowing its dynamic equations.

  8. Reproducibility of the NEPTUNE descriptor-based scoring system on whole-slide images and histologic and ultrastructural digital images.

    PubMed

    Barisoni, Laura; Troost, Jonathan P; Nast, Cynthia; Bagnasco, Serena; Avila-Casado, Carmen; Hodgin, Jeffrey; Palmer, Matthew; Rosenberg, Avi; Gasim, Adil; Liensziewski, Chrysta; Merlino, Lino; Chien, Hui-Ping; Chang, Anthony; Meehan, Shane M; Gaut, Joseph; Song, Peter; Holzman, Lawrence; Gibson, Debbie; Kretzler, Matthias; Gillespie, Brenda W; Hewitt, Stephen M

    2016-07-01

    The multicenter Nephrotic Syndrome Study Network (NEPTUNE) digital pathology scoring system employs a novel and comprehensive methodology to document pathologic features from whole-slide images, immunofluorescence and ultrastructural digital images. To estimate inter- and intra-reader concordance of this descriptor-based approach, data from 12 pathologists (eight NEPTUNE and four non-NEPTUNE) with experience from training to 30 years were collected. A descriptor reference manual was generated and a webinar-based protocol for consensus/cross-training implemented. Intra-reader concordance for 51 glomerular descriptors was evaluated on jpeg images by seven NEPTUNE pathologists scoring 131 glomeruli three times (Tests I, II, and III), each test following a consensus webinar review. Inter-reader concordance of glomerular descriptors was evaluated in 315 glomeruli by all pathologists; interstitial fibrosis and tubular atrophy (244 cases, whole-slide images) and four ultrastructural podocyte descriptors (178 cases, jpeg images) were evaluated once by six and five pathologists, respectively. Cohen's kappa for inter-reader concordance for 48/51 glomerular descriptors with sufficient observations was moderate (0.40based on similar pathologic features improved concordance. Concordance was independent of years of experience, and increased with webinar cross-training. Excellent concordance was achieved for interstitial fibrosis and tubular atrophy. Moderate-to-excellent concordance was achieved for all ultrastructural podocyte descriptors, with good-to-excellent concordance for descriptors commonly used in clinical practice, foot process effacement, and microvillous transformation. NEPTUNE digital pathology scoring system enables novel morphologic profiling of renal structures. For all histologic and ultrastructural descriptors tested with

  9. Reproducibility of the NEPTUNE descriptor-based scoring system on whole-slide images and histologic and ultrastructural digital images

    PubMed Central

    Barisoni, Laura; Troost, Jonathan P; Nast, Cynthia; Bagnasco, Serena; Avila-Casado, Carmen; Hodgin, Jeffrey; Palmer, Matthew; Rosenberg, Avi; Gasim, Adil; Liensziewski, Chrysta; Merlino, Lino; Chien, Hui-Ping; Chang, Anthony; Meehan, Shane M; Gaut, Joseph; Song, Peter; Holzman, Lawrence; Gibson, Debbie; Kretzler, Matthias; Gillespie, Brenda W; Hewitt, Stephen M

    2017-01-01

    The multicenter Nephrotic Syndrome Study Network (NEPTUNE) digital pathology scoring system employs a novel and comprehensive methodology to document pathologic features from whole-slide images, immunofluorescence and ultrastructural digital images. To estimate inter- and intra-reader concordance of this descriptor-based approach, data from 12 pathologists (eight NEPTUNE and four non-NEPTUNE) with experience from training to 30 years were collected. A descriptor reference manual was generated and a webinar-based protocol for consensus/cross-training implemented. Intra-reader concordance for 51 glomerular descriptors was evaluated on jpeg images by seven NEPTUNE pathologists scoring 131 glomeruli three times (Tests I, II, and III), each test following a consensus webinar review. Inter-reader concordance of glomerular descriptors was evaluated in 315 glomeruli by all pathologists; interstitial fibrosis and tubular atrophy (244 cases, whole-slide images) and four ultrastructural podocyte descriptors (178 cases, jpeg images) were evaluated once by six and five pathologists, respectively. Cohen’s kappa for inter-reader concordance for 48/51 glomerular descriptors with sufficient observations was moderate (0.40based on similar pathologic features improved concordance. Concordance was independent of years of experience, and increased with webinar cross-training. Excellent concordance was achieved for interstitial fibrosis and tubular atrophy. Moderate-to-excellent concordance was achieved for all ultrastructural podocyte descriptors, with good-to-excellent concordance for descriptors commonly used in clinical practice, foot process effacement, and microvillous transformation. NEPTUNE digital pathology scoring system enables novel morphologic profiling of renal structures. For all histologic and ultrastructural descriptors tested with

  10. Comparison of DSP schemes with frequency domain equalization for passive optical networks

    NASA Astrophysics Data System (ADS)

    Yang, Hui; Ye, Jia; Liu, Yanhe; Yan, Lianshan

    2015-08-01

    In recent years, digital signal processing (DSP) has been widely investigated for the applications in future next generation passive optical networks (PONs). In this paper, we compare four transmission technologies based on DSP with frequency domain equalization (FDE) for PON transmission with double-side band (DSB) intensity modulation and direct detection. These schemes include orthogonal frequency division multiplexing (OFDM), single-carrier frequency domain equalization (SCFDE), discrete Fourier transform spread orthogonal frequency division multiplexing (DFT-S-OFDM) and interleaved frequency division multiplexing (IFDM). We analyze their computational complexity and flexibility in PON applications, and compare their transmission performance by experiments. Based on above work, we propose and experimentally demonstrate a hybrid DSP-enhanced PON architecture with downstream OFDM modulation and upstream SCFDE modulation.

  11. A central neuropathic pain model by DSP-4 induced lesion of noradrenergic neurons: preliminary report.

    PubMed

    Kudo, Takashi; Kushikata, Tetsuya; Kudo, Mihoko; Kudo, Tsuyoshi; Hirota, Kazuyoshi

    2010-09-06

    Neuropathic pain models are classified as central and peripheral pain models. Although various peripheral neuropathic pain models are established, central pain models are based only on spinal cord injury. DSP-4 is a competitive inhibitor of norepinephrine uptake that selectively degenerates the locus coeruleus (LC)-noradrenergic neurons projection to the cerebral cortex and hippocampus. In the present study, we have tested whether lesion of LC-noradrenergic neurons by ip DSP-4 (0, 10, 30, 50 mg/kg, n=7 each) could provide a new central neuropathic pain model in rats using a hot-plate and tail-flick tests. DSP-4 significantly reduced the hot-plate latency and norepinephrine contents especially in the coerulean regions. However, DSP-4 did not change tail-flick latency. There are significant correlations of the latency in the hot-plate test with norepinephrine contents in the cerebral cortex (r=0.432, p=0.022), the hippocampus (r=0.465, p=0.013) and the pons (r=0.400, p=0.035) but not with those in the hypothalamus and the spinal cord. As response to hot-plate and tail-flick implies supra-spinal process and spinal reflex, respectively, central neuropathic pain may be facilitated by DSP-4 depleting LC-noradrenergic neurons although the present data are preliminary.

  12. Shuttle orbiter - IUS/DSP satellite interface contamination study

    NASA Technical Reports Server (NTRS)

    Rantanen, R. O.; Strange, D. A.

    1978-01-01

    The results of a contamination analysis on the Defense Support Program (DSP) satellite during launch and deployment by the Space Transportation System (STS) are presented. Predicted contaminant deposition was also included on critical DSP surfaces during the period soon after launch when the DSP is in the shuttle orbiter bay with the doors closed, the bay doors open, and during initial deployment. Additionally, a six sided box was placed at the spacecraft position to obtain directional contaminant flux information for a general payload while in the bay and during deployment. The analysis included contamination sources from the shuttle orbiter, IUS and cradle, the DSP sensor and the DSP support package.

  13. Sliding-mode control of single input multiple output DC-DC converter

    NASA Astrophysics Data System (ADS)

    Zhang, Libo; Sun, Yihan; Luo, Tiejian; Wan, Qiyang

    2016-10-01

    Various voltage levels are required in the vehicle mounted power system. A conventional solution is to utilize an independent multiple output DC-DC converter whose cost is high and control scheme is complicated. In this paper, we design a novel SIMO DC-DC converter with sliding mode controller. The proposed converter can boost the voltage of a low-voltage input power source to a controllable high-voltage DC bus and middle-voltage output terminals, which endow the converter with characteristics of simple structure, low cost, and convenient control. In addition, the sliding mode control (SMC) technique applied in our converter can enhance the performances of a certain SIMO DC-DC converter topology. The high-voltage DC bus can be regarded as the main power source to the high-voltage facility of the vehicle mounted power system, and the middle-voltage output terminals can supply power to the low-voltage equipment on an automobile. In the respect of control algorithm, it is the first time to propose the SMC-PID (Proportion Integration Differentiation) control algorithm, in which the SMC algorithm is utilized and the PID control is attended to the conventional SMC algorithm. The PID control increases the dynamic ability of the SMC algorithm by establishing the corresponding SMC surface and introducing the attached integral of voltage error, which endow the sliding-control system with excellent dynamic performance. At last, we established the MATLAB/SIMULINK simulation model, tested performance of the system, and built the hardware prototype based on Digital Signal Processor (DSP). Results show that the sliding mode control is able to track a required trajectory, which has robustness against the uncertainties and disturbances.

  14. Sliding-mode control of single input multiple output DC-DC converter.

    PubMed

    Zhang, Libo; Sun, Yihan; Luo, Tiejian; Wan, Qiyang

    2016-10-01

    Various voltage levels are required in the vehicle mounted power system. A conventional solution is to utilize an independent multiple output DC-DC converter whose cost is high and control scheme is complicated. In this paper, we design a novel SIMO DC-DC converter with sliding mode controller. The proposed converter can boost the voltage of a low-voltage input power source to a controllable high-voltage DC bus and middle-voltage output terminals, which endow the converter with characteristics of simple structure, low cost, and convenient control. In addition, the sliding mode control (SMC) technique applied in our converter can enhance the performances of a certain SIMO DC-DC converter topology. The high-voltage DC bus can be regarded as the main power source to the high-voltage facility of the vehicle mounted power system, and the middle-voltage output terminals can supply power to the low-voltage equipment on an automobile. In the respect of control algorithm, it is the first time to propose the SMC-PID (Proportion Integration Differentiation) control algorithm, in which the SMC algorithm is utilized and the PID control is attended to the conventional SMC algorithm. The PID control increases the dynamic ability of the SMC algorithm by establishing the corresponding SMC surface and introducing the attached integral of voltage error, which endow the sliding-control system with excellent dynamic performance. At last, we established the MATLAB/SIMULINK simulation model, tested performance of the system, and built the hardware prototype based on Digital Signal Processor (DSP). Results show that the sliding mode control is able to track a required trajectory, which has robustness against the uncertainties and disturbances.

  15. Project of universal DSP platform: cluster of floating point DSP processors

    NASA Astrophysics Data System (ADS)

    Dymanowski, Łukasz; Lewandowski, Kamil; Linczuk, Maciej

    2009-06-01

    In this paper, a project of cluster of DSP is presented. This project is realized as a extended card for PC computers. A block diagram of a board was described. A DSP processor properties for cluster computation was described. A block diagram of the board was discussed. Next, a details of hardware realization of this card was described. The PCB project was discussed. A details of multi-layers board was described.

  16. Adaptive terminal sliding mode control for hypersonic flight vehicles with strictly lower convex function based nonlinear disturbance observer.

    PubMed

    Wu, Yun-Jie; Zuo, Jing-Xing; Sun, Liang-Hua

    2017-08-23

    In this paper, the altitude and velocity tracking control of a generic hypersonic flight vehicle (HFV) is considered. A novel adaptive terminal sliding mode controller (ATSMC) with strictly lower convex function based nonlinear disturbance observer (SDOB) is proposed for the longitudinal dynamics of HFV in presence of both parametric uncertainties and external disturbances. First, for the sake of enhancing the anti-interference capability, SDOB is presented to estimate and compensate the equivalent disturbances by introducing a strictly lower convex function. Next, the SDOB based ATSMC (SDOB-ATSMC) is proposed to guarantee the system outputs track the reference trajectory. Then, stability of the proposed control scheme is analyzed by the Lyapunov function method. Compared with other HFV control approaches, key novelties of SDOB-ATSMC are that a novel SDOB is proposed and drawn into the (virtual) control laws to compensate the disturbances and that several adaptive laws are used to deal with the differential explosion problem. Finally, it is illustrated by the simulation results that the new method exhibits an excellent robustness and a better disturbance rejection performance than the convention approach. Copyright © 2017 ISA. Published by Elsevier Ltd. All rights reserved.

  17. A multi-mode operation control strategy for flexible microgrid based on sliding-mode direct voltage and hierarchical controls.

    PubMed

    Zhang, Qinjin; Liu, Yancheng; Zhao, Youtao; Wang, Ning

    2016-03-01

    Multi-mode operation and transient stability are two problems that significantly affect flexible microgrid (MG). This paper proposes a multi-mode operation control strategy for flexible MG based on a three-layer hierarchical structure. The proposed structure is composed of autonomous, cooperative, and scheduling controllers. Autonomous controller is utilized to control the performance of the single micro-source inverter. An adaptive sliding-mode direct voltage loop and an improved droop power loop based on virtual negative impedance are presented respectively to enhance the system disturbance-rejection performance and the power sharing accuracy. Cooperative controller, which is composed of secondary voltage/frequency control and phase synchronization control, is designed to eliminate the voltage/frequency deviations produced by the autonomous controller and prepare for grid connection. Scheduling controller manages the power flow between the MG and the grid. The MG with the improved hierarchical control scheme can achieve seamless transitions from islanded to grid-connected mode and have a good transient performance. In addition the presented work can also optimize the power quality issues and improve the load power sharing accuracy between parallel VSIs. Finally, the transient performance and effectiveness of the proposed control scheme are evaluated by theoretical analysis and simulation results.

  18. Design of an adaptive fuzzy sliding mode control for uncertain discrete-time nonlinear systems based on noisy measurements

    NASA Astrophysics Data System (ADS)

    Yoshimura, Toshio

    2016-02-01

    This paper presents the design of an adaptive fuzzy sliding mode control (AFSMC) for uncertain discrete-time nonlinear dynamic systems. The dynamic systems are described by a discrete-time state equation with nonlinear uncertainties, and the uncertainties include the modelling errors and the external disturbances to be unknown but nonlinear with the bounded properties. The states are measured by the restriction of measurement sensors and the contamination with independent measurement noises. The nonlinear uncertainties are approximated by using the fuzzy IF-THEN rules based on the universal approximation theorem, and the approximation error is compensated by adding an adaptive complementary term to the proposed AFSMC. The fuzzy inference approach based on the extended single input rule modules is proposed to reduce the number of the fuzzy IF-THEN rules. The estimates for the un-measurable states and the adjustable parameters are obtained by using the weighted least squares estimator and its simplified one. It is proved that under some conditions the estimation errors will remain in the vicinity of zero as time increases, and the states are ultimately bounded subject to the proposed AFSMC. The effectiveness of the proposed method is indicated through the simulation experiment of a simple numerical system.

  19. Tribological evaluation of PS300: A new chrome oxide based solid lubricant coating sliding against Al2O3 From 25 to 650 C

    NASA Technical Reports Server (NTRS)

    DellaCorte, C.; Laskowski, J. A.

    1996-01-01

    This paper presents the tribological characteristics of Al203 sliding against PS300; a chrome oxide based self lubricating coating. Al203 pins were slid against PS300 coated superalloy disks in air, under a 4.9 N load at velocities of 1 to 8 m/s. At a sliding velocity of 1 m/s, friction ranged from 0.6 at 25 C to 0.2 at 650 C. Wear factors for the Al203 pins were in the 10(exp -7) mm(exp 3)/N-m range and for the PS300 coating was in the 10(exp -5) mm(exp 3)/N-m range. The test results suggest that increased surface temperature resulting from either frictional heating, generated by increased sliding velocity, or ambient heating caused a reduction in friction and wear of the sliding couple. Based upon these results, the tested material combination is a promising candidate for high temperature wear applications.

  20. A Novel Dual Separate Paths (DSP) Algorithm Providing Fault-Tolerant Communication for Wireless Sensor Networks.

    PubMed

    Tien, Nguyen Xuan; Kim, Semog; Rhee, Jong Myung; Park, Sang Yoon

    2017-07-25

    Fault tolerance has long been a major concern for sensor communications in fault-tolerant cyber physical systems (CPSs). Network failure problems often occur in wireless sensor networks (WSNs) due to various factors such as the insufficient power of sensor nodes, the dislocation of sensor nodes, the unstable state of wireless links, and unpredictable environmental interference. Fault tolerance is thus one of the key requirements for data communications in WSN applications. This paper proposes a novel path redundancy-based algorithm, called dual separate paths (DSP), that provides fault-tolerant communication with the improvement of the network traffic performance for WSN applications, such as fault-tolerant CPSs. The proposed DSP algorithm establishes two separate paths between a source and a destination in a network based on the network topology information. These paths are node-disjoint paths and have optimal path distances. Unicast frames are delivered from the source to the destination in the network through the dual paths, providing fault-tolerant communication and reducing redundant unicast traffic for the network. The DSP algorithm can be applied to wired and wireless networks, such as WSNs, to provide seamless fault-tolerant communication for mission-critical and life-critical applications such as fault-tolerant CPSs. The analyzed and simulated results show that the DSP-based approach not only provides fault-tolerant communication, but also improves network traffic performance. For the case study in this paper, when the DSP algorithm was applied to high-availability seamless redundancy (HSR) networks, the proposed DSP-based approach reduced the network traffic by 80% to 88% compared with the standard HSR protocol, thus improving network traffic performance.

  1. A Novel Dual Separate Paths (DSP) Algorithm Providing Fault-Tolerant Communication for Wireless Sensor Networks

    PubMed Central

    Tien, Nguyen Xuan; Kim, Semog; Rhee, Jong Myung

    2017-01-01

    Fault tolerance has long been a major concern for sensor communications in fault-tolerant cyber physical systems (CPSs). Network failure problems often occur in wireless sensor networks (WSNs) due to various factors such as the insufficient power of sensor nodes, the dislocation of sensor nodes, the unstable state of wireless links, and unpredictable environmental interference. Fault tolerance is thus one of the key requirements for data communications in WSN applications. This paper proposes a novel path redundancy-based algorithm, called dual separate paths (DSP), that provides fault-tolerant communication with the improvement of the network traffic performance for WSN applications, such as fault-tolerant CPSs. The proposed DSP algorithm establishes two separate paths between a source and a destination in a network based on the network topology information. These paths are node-disjoint paths and have optimal path distances. Unicast frames are delivered from the source to the destination in the network through the dual paths, providing fault-tolerant communication and reducing redundant unicast traffic for the network. The DSP algorithm can be applied to wired and wireless networks, such as WSNs, to provide seamless fault-tolerant communication for mission-critical and life-critical applications such as fault-tolerant CPSs. The analyzed and simulated results show that the DSP-based approach not only provides fault-tolerant communication, but also improves network traffic performance. For the case study in this paper, when the DSP algorithm was applied to high-availability seamless redundancy (HSR) networks, the proposed DSP-based approach reduced the network traffic by 80% to 88% compared with the standard HSR protocol, thus improving network traffic performance. PMID:28757544

  2. Sliding vane geometry turbines

    DOEpatents

    Sun, Harold Huimin; Zhang, Jizhong; Hu, Liangjun; Hanna, Dave R

    2014-12-30

    Various systems and methods are described for a variable geometry turbine. In one example, a turbine nozzle comprises a central axis and a nozzle vane. The nozzle vane includes a stationary vane and a sliding vane. The sliding vane is positioned to slide in a direction substantially tangent to an inner circumference of the turbine nozzle and in contact with the stationary vane.

  3. Active micro-actuators for optical modulation based on a planar sliding triboelectric nanogenerator.

    PubMed

    Zhang, Chi; Tang, Wei; Pang, Yaokun; Han, Changbao; Wang, Zhong Lin

    2015-01-27

    Based on a triboelectric nanogenerator (TENG), the first active micro-actuator for optical modulation driven by mechanical energy without external power or mechanical joint is presented. This demonstrates the enormous potential of TENGs for independent and sustainable self-powered micro/nano electromechanical systems, and opens up new -applications of TENGs in triboelectric-voltage-controlled devices.

  4. Wavelet Kernels on a DSP: A Comparison between Lifting and Filter Banks for Image Coding

    NASA Astrophysics Data System (ADS)

    Gnavi, Stefano; Penna, Barbara; Grangetto, Marco; Magli, Enrico; Olmo, Gabriella

    2002-12-01

    We develop wavelet engines on a digital signal processors (DSP) platform, the target application being image and intraframe video compression by means of the forthcoming JPEG2000 and Motion-JPEG2000 standards. We describe two implementations, based on the lifting scheme and the filter bank scheme, respectively, and we present experimental results on code profiling. In particular, we address the following problems: (1) evaluating the execution speed of a wavelet engine on a modern DSP; (2) comparing the actual execution speed of the lifting scheme and the filter bank scheme with the theoretical results; (3) using the on-board direct memory access (DMA) to possibly optimize the execution speed. The results allow to assess the performance of a modern DSP in the image coding task, as well as to compare the lifting and filter bank performance in a realistic application scenario. Finally, guidelines for optimizing the code efficiency are provided by investigating the possible use of the on-board DMA.

  5. swDMR: A Sliding Window Approach to Identify Differentially Methylated Regions Based on Whole Genome Bisulfite Sequencing

    PubMed Central

    Shao, Qianzhi; Liu, Qi; Chen, BingYu; Huang, Dongsheng

    2015-01-01

    DNA methylation is a widespread epigenetic modification that plays an essential role in gene expression through transcriptional regulation and chromatin remodeling. The emergence of whole genome bisulfite sequencing (WGBS) represents an important milestone in the detection of DNA methylation. Characterization of differential methylated regions (DMRs) is fundamental as well for further functional analysis. In this study, we present swDMR (http://sourceforge.net/projects/swdmr/) for the comprehensive analysis of DMRs from whole genome methylation profiles by a sliding window approach. It is an integrated tool designed for WGBS data, which not only implements accessible statistical methods to perform hypothesis test adapted to two or more samples without replicates, but false discovery rate was also controlled by multiple test correction. Downstream analysis tools were also provided, including cluster, annotation and visualization modules. In summary, based on WGBS data, swDMR can produce abundant information of differential methylated regions. As a convenient and flexible tool, we believe swDMR will bring us closer to unveil the potential functional regions involved in epigenetic regulation. PMID:26176536

  6. A rat 8 kb dentin sialoprotein-phosphophoryn (DSP-PP) promoter directs spatial and temporal LacZ activity in mouse tissues.

    PubMed

    Godovikova, Valentina; Li, Xiu-Rong; Saunders, Thomas L; Ritchie, Helena H

    2006-01-15

    Dentin sialoprotein (DSP) and phosphophoryn (PP) are two major dentin noncollagenous proteins that are encoded on a single DSP-PP transcript whose expression is tightly regulated during tooth dentinogenesis. The recent identification of this gene transcript in other tissues, including inner ear and jaw tissue, suggests that DSP and PP may have pleiotropic effects on other organs besides teeth. To identify candidate regulatory elements that control DSP-PP temporal and spatial expression, we constructed a -5 kb upstream region rat DSP-PP promoter into the beta-galactosidase expression vector pnLacF plasmid and used this construct to prepare DSP-PP-LacZ transgenic mice. Multiple mouse tissues including teeth, bone, and kidney obtained from the six resulting transgenic mouse lines displayed strong LacZ activity. This spatial distribution was confirmed in several of these tissues by in situ hybridization studies. LacZ activity was transiently expressed in preameloblasts and continuously expressed in odontoblasts demonstrating that this -5 kb rat promoter-dependent LacZ expression mimics reported DSP-PP mRNA expression patterns. Interestingly, this -5 kb rat promoter construct drives LacZ expression according to the rat developmental clock. Based on identified transcription factors present in this -5 kb promoter region, we have identified several probable cis-regulatory modules whose interaction with one another could account for the spatial and temporal distribution of DSP-PP transcripts in developing tissues.

  7. Hierarchical patch-based co-registration of differently stained histopathology slides

    NASA Astrophysics Data System (ADS)

    Yigitsoy, Mehmet; Schmidt, Günter

    2017-03-01

    Over the past decades, digital pathology has emerged as an alternative way of looking at the tissue at subcellular level. It enables multiplexed analysis of different cell types at micron level. Information about cell types can be extracted by staining sections of a tissue block using different markers. However, robust fusion of structural and functional information from different stains is necessary for reproducible multiplexed analysis. Such a fusion can be obtained via image co-registration by establishing spatial correspondences between tissue sections. Spatial correspondences can then be used to transfer various statistics about cell types between sections. However, the multi-modal nature of images and sparse distribution of interesting cell types pose several challenges for the registration of differently stained tissue sections. In this work, we propose a co-registration framework that efficiently addresses such challenges. We present a hierarchical patch-based registration of intensity normalized tissue sections. Preliminary experiments demonstrate the potential of the proposed technique for the fusion of multi-modal information from differently stained digital histopathology sections.

  8. High-contrast fluorescence microscopy for a biomolecular analysis based on polarization techniques using an optical interference mirror slide.

    PubMed

    Yasuda, Mitsuru; Akimoto, Takuo

    2014-12-01

    Fluorescence microscopy with an improved contrast for fluorescence images is developed using an optical interference mirror (OIM) slide, which can enhance the fluorescence from a fluorophore as a result of the double interference of the excitation light and emission light. To improve the contrast of a fluorescence image using an OIM slide, a linearly-polarized excitation light was employed, and the fluorescence emission polarized perpendicular to the polarization of the excitation light was detected. The image contrast with this optical system was improved 110-fold for rhodamine B spotted on the OIM, in comparison with a glass slide using a general fluorescence microscopy optical system. Moreover, a 24-fold improvement of the image contrast was achieved for the detection of Cy3-labeled streptavidin bound to immobilize biotin.

  9. On-the-fly selection of cell-specific enhancers, genes, miRNAs and proteins across the human body using SlideBase

    PubMed Central

    Ienasescu, Hans; Li, Kang; Andersson, Robin; Vitezic, Morana; Rennie, Sarah; Chen, Yun; Vitting-Seerup, Kristoffer; Lagoni, Emil; Boyd, Mette; Bornholdt, Jette; de Hoon, Michiel J. L.; Kawaji, Hideya; Lassmann, Timo; Hayashizaki, Yoshihide; Forrest, Alistair R. R.; Carninci, Piero; Sandelin, Albin

    2016-01-01

    Genomics consortia have produced large datasets profiling the expression of genes, micro-RNAs, enhancers and more across human tissues or cells. There is a need for intuitive tools to select subsets of such data that is the most relevant for specific studies. To this end, we present SlideBase, a web tool which offers a new way of selecting genes, promoters, enhancers and microRNAs that are preferentially expressed/used in a specified set of cells/tissues, based on the use of interactive sliders. With the help of sliders, SlideBase enables users to define custom expression thresholds for individual cell types/tissues, producing sets of genes, enhancers etc. which satisfy these constraints. Changes in slider settings result in simultaneous changes in the selected sets, updated in real time. SlideBase is linked to major databases from genomics consortia, including FANTOM, GTEx, The Human Protein Atlas and BioGPS. Database URL: http://slidebase.binf.ku.dk PMID:28025337

  10. On-the-fly selection of cell-specific enhancers, genes, miRNAs and proteins across the human body using SlideBase.

    PubMed

    Ienasescu, Hans; Li, Kang; Andersson, Robin; Vitezic, Morana; Rennie, Sarah; Chen, Yun; Vitting-Seerup, Kristoffer; Lagoni, Emil; Boyd, Mette; Bornholdt, Jette; de Hoon, Michiel J L; Kawaji, Hideya; Lassmann, Timo; Hayashizaki, Yoshihide; Forrest, Alistair R R; Carninci, Piero; Sandelin, Albin

    2016-01-01

    Genomics consortia have produced large datasets profiling the expression of genes, micro-RNAs, enhancers and more across human tissues or cells. There is a need for intuitive tools to select subsets of such data that is the most relevant for specific studies. To this end, we present SlideBase, a web tool which offers a new way of selecting genes, promoters, enhancers and microRNAs that are preferentially expressed/used in a specified set of cells/tissues, based on the use of interactive sliders. With the help of sliders, SlideBase enables users to define custom expression thresholds for individual cell types/tissues, producing sets of genes, enhancers etc. which satisfy these constraints. Changes in slider settings result in simultaneous changes in the selected sets, updated in real time. SlideBase is linked to major databases from genomics consortia, including FANTOM, GTEx, The Human Protein Atlas and BioGPS.Database URL: http://slidebase.binf.ku.dk.

  11. Sliding-mode and proportional-derivative-type motion control with radial basis function neural network based estimators for wheeled vehicles

    NASA Astrophysics Data System (ADS)

    Pamosoaji, Anugrah K.; Thuong Cat, Pham; Hong, Keum-Shik

    2014-12-01

    An obstacle avoidance problem of rear-steered wheeled vehicles in consideration of the presence of uncertainties is addressed. Modelling errors and additional uncertainties are taken into consideration. Controller designs for driving and steering motors are designed. A proportional-derivative-type driving motor controller and a sliding-mode steering controller combined with radial basis function neural network (RBFNN) based estimators are proposed. The convergence properties of the RBFNN-based estimators are proven by the Stone-Weierstrass theorem. The stability of the proposed control law is proven using Lyapunov stability analysis. The obstacle avoidance strategy utilising the sliding surface adjustment to an existing navigation method is presented. It is concluded that the driving velocity and steering-angle performances of the proposed control system are satisfactory.

  12. Mixed H∞ and passive projective synchronization for fractional-order memristor-based neural networks with time delays via adaptive sliding mode control

    NASA Astrophysics Data System (ADS)

    Song, Shuai; Song, Xiaona; Balsera, Ines Tejado

    2017-05-01

    This paper investigates the mixed H∞ and passive projective synchronization problem for fractional-order (FO) memristor-based neural networks with time delays. Our aim is to design a controller such that, though the unavoidable phenomena of time delay and external disturbances is fully considered, the resulting closed-loop system is stable with a mixed H∞ and passive performance level. By combining sliding mode control and adaptive control methods, a novel adaptive sliding mode control strategy is designed for the synchronization of time-delayed FO dynamic networks. Via the application of FO system stability theory, the projective synchronization conditions are addressed in terms of linear matrix inequalities. Based on the conditions, a desired controller which can guarantee the stability of the closed-loop system and also ensure a mixed H∞ and passive performance level is designed. Finally, two simulation examples are given to illustrate the effectiveness of the proposed method.

  13. Sliding mode control based impact angle control guidance considering the seeker׳s field-of-view constraint.

    PubMed

    Wang, Xingliang; Zhang, Youan; Wu, Huali

    2016-03-01

    The problem of impact angle control guidance for a field-of-view constrained missile against non-maneuvering or maneuvering targets is solved by using the sliding mode control theory. The existing impact angle control guidance laws with field-of-view constraint are only applicable against stationary targets and most of them suffer abrupt-jumping of guidance command due to the application of additional guidance mode switching logic. In this paper, the field-of-view constraint is handled without using any additional switching logic. In particular, a novel time-varying sliding surface is first designed to achieve zero miss distance and zero impact angle error without violating the field-of-view constraint during the sliding mode phase. Then a control integral barrier Lyapunov function is used to design the reaching law so that the sliding mode can be reached within finite time and the field-of-view constraint is not violated during the reaching phase as well. A nonlinear extended state observer is constructed to estimate the disturbance caused by unknown target maneuver, and the undesirable chattering is alleviated effectively by using the estimation as a compensation item in the guidance law. The performance of the proposed guidance law is illustrated with simulations.

  14. The Impact of Providing Web-Based PowerPoint Slides as Study Guides in Undergraduate Business Classes

    ERIC Educational Resources Information Center

    Frank, Jonathan; Shaw, Lewis; Wilson, Elizabeth

    2009-01-01

    This study examines undergraduate business students' use of PowerPoint slides provided as a supplement to class attendance, textbook reading, and other traditional course resources. We survey students in 4 diverse (accounting, marketing, management, and information systems) lower-level undergraduate courses in which the instructor provided…

  15. The Impact of Providing Web-Based PowerPoint Slides as Study Guides in Undergraduate Business Classes

    ERIC Educational Resources Information Center

    Frank, Jonathan; Shaw, Lewis; Wilson, Elizabeth

    2009-01-01

    This study examines undergraduate business students' use of PowerPoint slides provided as a supplement to class attendance, textbook reading, and other traditional course resources. We survey students in 4 diverse (accounting, marketing, management, and information systems) lower-level undergraduate courses in which the instructor provided…

  16. Web-based oil immersion whole slide imaging increases efficiency and clinical team satisfaction in hematopathology tumor board

    PubMed Central

    Chen, Zhongchuan Will; Kohan, Jessica; Perkins, Sherrie L.; Hussong, Jerry W.; Salama, Mohamed E.

    2014-01-01

    Background: Whole slide imaging (WSI) is widely used for education and research, but is increasingly being used to streamline clinical workflow. We present our experience with regard to satisfaction and time utilization using oil immersion WSI for presentation of blood/marrow aspirate smears, core biopsies, and tissue sections in hematology/oncology tumor board/treatment planning conferences (TPC). Methods: Lymph nodes and bone marrow core biopsies were scanned at ×20 magnification and blood/marrow smears at 83X under oil immersion and uploaded to an online library with areas of interest to be displayed annotated digitally via web browser. Pathologist time required to prepare slides for scanning was compared to that required to prepare for microscope projection (MP). Time required to present cases during TPC was also compared. A 10-point evaluation survey was used to assess clinician satisfaction with each presentation method. Results: There was no significant difference in hematopathologist preparation time between WSI and MP. However, presentation time was significantly less for WSI compared to MP as selection and annotation of slides was done prior to TPC with WSI, enabling more efficient use of TPC presentation time. Survey results showed a significant increase in satisfaction by clinical attendees with regard to image quality, efficiency of presentation of pertinent findings, aid in clinical decision-making, and overall satisfaction regarding pathology presentation. A majority of respondents also noted decreased motion sickness with WSI. Conclusions: Whole slide imaging, particularly with the ability to use oil scanning, provides higher quality images compared to MP and significantly increases clinician satisfaction. WSI streamlines preparation for TPC by permitting prior slide selection, resulting in greater efficiency during TPC presentation. PMID:25379347

  17. Designing Good Slides. Revised.

    ERIC Educational Resources Information Center

    Center for Disease Control (DHEW/PHS), Atlanta, GA.

    This guide is designed to help those who want to illustrate material in a formal presentation using 35mm double-frame slides, and it is also useful as a guide for teaching students how to work with slides. The guide provides a step-by-step procedure for each format. For instance, those who want to design a slide with copy only would go through a…

  18. DSP accelerator for the wavelet compression/decompression of high- resolution images

    SciTech Connect

    Hunt, M.A.; Gleason, S.S.; Jatko, W.B.

    1993-07-23

    A Texas Instruments (TI) TMS320C30-based S-Bus digital signal processing (DSP) module was used to accelerate a wavelet-based compression and decompression algorithm applied to high-resolution fingerprint images. The law enforcement community, together with the National Institute of Standards and Technology (NISI), is adopting a standard based on the wavelet transform for the compression, transmission, and decompression of scanned fingerprint images. A two-dimensional wavelet transform of the input image is computed. Then spatial/frequency regions are automatically analyzed for information content and quantized for subsequent Huffman encoding. Compression ratios range from 10:1 to 30:1 while maintaining the level of image quality necessary for identification. Several prototype systems were developed using SUN SPARCstation 2 with a 1280 {times} 1024 8-bit display, 64-Mbyte random access memory (RAM), Tiber distributed data interface (FDDI), and Spirit-30 S-Bus DSP-accelerators from Sonitech. The final implementation of the DSP-accelerated algorithm performed the compression or decompression operation in 3.5 s per print. Further increases in system throughput were obtained by adding several DSP accelerators operating in parallel.

  19. Application of DSP Blackfin in data acquisition of high speed

    NASA Astrophysics Data System (ADS)

    Tang, Chao

    2015-12-01

    In the traditional digital collection, the use of FIFO and MCU is usually used. Traditional data acquisition systems are expensive and slow, When the input is a fast changing signal, the output will have a large distortion, which makes the whole system performance degradation, and not suitable for large amounts of data. In this paper, a new method of high speed data acquisition based on Blackfin DSP is presented, The analog signal is processed by the signal processing circuit, so that the amplitude of the signal is limited to the input range of the A/D converter. The whole collection system is determined by the data acquisition and control circuit. In order to further improve the speed of data transmission, DSP Blackfin uses advanced DMA technology. In the algorithm, the system is mainly used in the same sampling points for the average value of the method. Experimental results show, Using the traditional system, it will lose a lot of details, the destruction of the integrity of the signal. Using this system can well reconstruct the analog signal input, Especially in the large amount of data, it shows the incomparable advantages.

  20. Active fault tolerant control based on interval type-2 fuzzy sliding mode controller and non linear adaptive observer for 3-DOF laboratory helicopter.

    PubMed

    Zeghlache, Samir; Benslimane, Tarak; Bouguerra, Abderrahmen

    2017-09-14

    In this paper, a robust controller for a three degree of freedom (3 DOF) helicopter control is proposed in presence of actuator and sensor faults. For this purpose, Interval type-2 fuzzy logic control approach (IT2FLC) and sliding mode control (SMC) technique are used to design a controller, named active fault tolerant interval type-2 Fuzzy Sliding mode controller (AFTIT2FSMC) based on non-linear adaptive observer to estimate and detect the system faults for each subsystem of the 3-DOF helicopter. The proposed control scheme allows avoiding difficult modeling, attenuating the chattering effect of the SMC, reducing the rules number of the fuzzy controller. Exponential stability of the closed loop is guaranteed by using the Lyapunov method. The simulation results show that the AFTIT2FSMC can greatly alleviate the chattering effect, providing good tracking performance, even in presence of actuator and sensor faults. Copyright © 2017 ISA. Published by Elsevier Ltd. All rights reserved.

  1. A vehicle ABS adaptive sliding-mode control algorithm based on the vehicle velocity estimation and tyre/road friction coefficient estimations

    NASA Astrophysics Data System (ADS)

    Zhang, Xiangwen; Xu, Yong; Pan, Ming; Ren, Fenghua

    2014-04-01

    A sliding-mode observer is designed to estimate the vehicle velocity with the measured vehicle acceleration, the wheel speeds and the braking torques. Based on the Burckhardt tyre model, the extended Kalman filter is designed to estimate the parameters of the Burckhardt model with the estimated vehicle velocity, the measured wheel speeds and the vehicle acceleration. According to the estimated parameters of the Burckhardt tyre model, the tyre/road friction coefficients and the optimal slip ratios are calculated. A vehicle adaptive sliding-mode control (SMC) algorithm is presented with the estimated vehicle velocity, the tyre/road friction coefficients and the optimal slip ratios. And the adjustment method of the sliding-mode gain factors is discussed. Based on the adaptive SMC algorithm, a vehicle's antilock braking system (ABS) control system model is built with the Simulink Toolbox. Under the single-road condition as well as the different road conditions, the performance of the vehicle ABS system is simulated with the vehicle velocity observer, the tyre/road friction coefficient estimator and the adaptive SMC algorithm. The results indicate that the estimated errors of the vehicle velocity and the tyre/road friction coefficients are acceptable and the vehicle ABS adaptive SMC algorithm is effective. So the proposed adaptive SMC algorithm can be used to control the vehicle ABS without the information of the vehicle velocity and the road conditions.

  2. Decoupling control based on terminal sliding mode and wavelet network for the speed and tension system of reversible cold strip rolling mill

    NASA Astrophysics Data System (ADS)

    Fang, Yiming; Liu, Le; Li, Jianxiong; Xu, Yanze

    2015-08-01

    To weaken the nonlinear coupling influences among the variables in the speed and tension system of reversible cold strip rolling mill, a novel dynamic decoupling control strategy is proposed based on nonsingular fast terminal sliding mode (NFTSM) and wavelet neural network (WNN). First, nonlinear disturbance observers are developed to counteract the mismatched uncertainties, and then input/output dynamic decoupling and linearisation for the speed and tension nonlinear coupling system are realised by utilising the inverse system theory. Second, nonsingular fast terminal sliding mode controller (NFTSMC) for each pseudo linear subsystem is presented based on backstepping and two-power reaching law, so as to improve the global convergence speed and robust stability of the system. Third, adaptive WNNs are used to approximate the uncertain items of the system, so as to improve the control precision of the speed and tension of reversible cold strip rolling mill. Theoretical analyses show that the NFTSMs satisfy reachability condition, the system error variables can converge to equilibrium point in finite time, and the resulting closed-loop system is globally asymptotically stable. Finally, simulation research is carried out on the speed and tension system of a 1422 mm reversible cold strip rolling mill by using the actual data, and results show the superiority of the proposed control strategy in comparison with the strategies of cascade PI, linear sliding mode control and internal model control.

  3. Optimal second order sliding mode control for nonlinear uncertain systems.

    PubMed

    Das, Madhulika; Mahanta, Chitralekha

    2014-07-01

    In this paper, a chattering free optimal second order sliding mode control (OSOSMC) method is proposed to stabilize nonlinear systems affected by uncertainties. The nonlinear optimal control strategy is based on the control Lyapunov function (CLF). For ensuring robustness of the optimal controller in the presence of parametric uncertainty and external disturbances, a sliding mode control scheme is realized by combining an integral and a terminal sliding surface. The resulting second order sliding mode can effectively reduce chattering in the control input. Simulation results confirm the supremacy of the proposed optimal second order sliding mode control over some existing sliding mode controllers in controlling nonlinear systems affected by uncertainty.

  4. Direct power control of DFIG wind turbine systems based on an intelligent proportional-integral sliding mode control.

    PubMed

    Li, Shanzhi; Wang, Haoping; Tian, Yang; Aitouch, Abdel; Klein, John

    2016-09-01

    This paper presents an intelligent proportional-integral sliding mode control (iPISMC) for direct power control of variable speed-constant frequency wind turbine system. This approach deals with optimal power production (in the maximum power point tracking sense) under several disturbance factors such as turbulent wind. This controller is made of two sub-components: (i) an intelligent proportional-integral module for online disturbance compensation and (ii) a sliding mode module for circumventing disturbance estimation errors. This iPISMC method has been tested on FAST/Simulink platform of a 5MW wind turbine system. The obtained results demonstrate that the proposed iPISMC method outperforms the classical PI and intelligent proportional-integral control (iPI) in terms of both active power and response time. Copyright © 2016 ISA. Published by Elsevier Ltd. All rights reserved.

  5. Prediction of scuffing failure based on competitive kinetics of oxide formation and removal: Application to lubricated sliding of AISI 52100 steel on steel

    NASA Astrophysics Data System (ADS)

    Cutiongco, Eric C.; Chung, Yip-Wah

    1994-07-01

    A method for predicting scuffing failure based on the competitive kinetics of oxide formation and removal has been developed and applied to the sliding of AISI 52100 steel on steel with poly-alpha-olefin as the lubricant. Oxide formation rates were determining using static oxidation tests on coupons of 52100 steel covered with poly-alpha-olefin at temperatures of 140 C to 250 C. Oxide removal rates were determined at different combinations of initial average nominal contact pressures (950 MPa to 1578 MPa) and sliding velocities (0.4 m/s to 1.8 m/s) using a ball-on-disk vacuum tribotester. The nominal asperity flash temperatures generated during the wear tests were calculated and the temperatures corresponding to the intersection of the the Arrhenius plots of oxide formation and removal rates were determined and taken as the critical failure temperatures. The pressure-velocity failure transition diagram was constructed by plotting the critical failure temperatures along isotherms of average nominal asperity flash temperatures calculated at different combinations of contact stress and sliding speed. The predicted failure transition curve agreed well with experimental scuffing data.

  6. Herbaceous Ornamental Plants. Slide Script.

    ERIC Educational Resources Information Center

    Still, Steven

    This slide script, part of a series of slide scripts designed for use in vocational agriculture classes, deals with commercially important herbaceous ornamental plants. Included in the script are narrations for use with a total of 338 slides illustrating 150 different plants. Generally, two slides are used to illustrate each plant: one slide shows…

  7. CT-fluoroscopy in chest interventional radiology: sliding scale of imaging parameters based on radiation exposure dose and factors increasing radiation exposure dose.

    PubMed

    Yamao, Yoshikazu; Yamakado, K; Takaki, H; Yamada, T; Kodama, H; Nagasawa, N; Nakatsuka, A; Uraki, J; Takeda, K

    2013-02-01

    To verify the usefulness of a sliding scale of imaging parameters to reduce radiation exposure during chest interventional radiology (IR), and to identify factors that increase radiation exposure in order to obtain acceptable computed tomography (CT)-fluoroscopy image quality. The institutional review board approved this retrospective study, for which the need for informed consent was waived. Interventional radiologists determined the optimal CT-fluoroscopy imaging parameters using the sliding scale based on the radiation exposure dose. The imaging parameters were changed from those generating low radiation (120 kV/10 mA, 1.2 mGy/s) to others generating higher radiation exposure until acceptable image quality was obtained for each procedure. Validation of the imaging parameter sliding scale was done using regression analysis. Factors that increase radiation exposure were identified using multiple regression analysis. In 125 patients, 217 procedures were performed, of which 72 procedures (33.2%, 72/217) were performed with imaging parameters of minimum radiation exposure, but increased radiation exposure was necessary in 145 (66.8%, 145/217). Significant correlation was found between the radiation exposure dose and the percentage achievement of acceptable image quality (R(2) = 0.98). Multivariate regression analysis showed that high body weight (p < 0.0001), long device passage (p < 0.0001), and lesions above the aortic arch (p = 0.04) were significant independent factors increasing radiation exposure. Although increased radiation exposure dose might be necessary to obtain acceptable chest CT-fluoroscopy images depending on the patient, lesion, and procedure characteristics, a sliding scale of imaging parameters helps to reduce radiation exposure. Copyright © 2012 The Royal College of Radiologists. Published by Elsevier Ltd. All rights reserved.

  8. Mailing microscope slides

    USDA-ARS?s Scientific Manuscript database

    Many insects feed agriculturally important crops, trees, and ornamental plants and cause millions of dollars of damage annually. Identification for some of these require the preparation of a microscope slide for examination. There are times when a microscope slide may need to be sent away to a speci...

  9. Evaluating the visibility of presentation slides

    NASA Astrophysics Data System (ADS)

    Sugawara, Genki; Umezu, Nobuyuki

    2017-03-01

    Presentations using slide software such as PowerPoint are widely performed in offices and schools. The improvement of presentation skills among ordinary people is required because these days such an opportunity of giving presentation is becoming so common. One of the key factors for making successful presentation is the visibility of the slides, as well as the contents themselves. We propose an algorithm to numerically evaluate the visibility of presentation slides. Our method receives a presentation as a set of images and eliminates the background from the slides to extract characters and figures. This algorithm then evaluates the visibility according to the number and size of characters, their colors, and figure layouts. The slide evaluation criteria are based on the series of experiments with 20 participants to parameterize typical values for visual elements in slides. The algorithm is implemented on an iMac and takes 0.5 sec. to evaluate a slide image. The evaluation score is given as a value between 0 and 100 and the users can improve their slide pages with lower scores. Our future work includes a series of experiments with various presentations and extending our method to publish as a web-based rating service for learning presentation skills.

  10. Sliding induced crystallization of metallic glass

    NASA Technical Reports Server (NTRS)

    Miyoshi, K.; Buckley, D. H.

    1983-01-01

    Sliding friction and wear experiments, electron microscopy, and diffraction studies were conducted with an Fe67Co18B14Si1 ferrous-base metallic glass in sliding contact with aluminum oxide at room temperature in air. The results indicate that the amorphous alloy can be crystallized during the sliding process. Crystallization of the wear surface causes high friction. Plastic flow occurred on the amorphous alloy with sliding, and the flow film of the alloy transferred to the aluminum oxide surface. Two distinct types of wear debris were observed as a result of sliding: an alloy wear debris, and powdery and whiskery oxide debris. Generation of oxide wear debris particles on an alloy can cause transitions in friction behavior.

  11. An Audit of Failed Immunohistochemical Slides in a Clinical Laboratory: The Role of On-Slide Controls.

    PubMed

    Cheung, Carol C; Taylor, Clive R; Torlakovic, Emina E

    Appropriate controls are critical for the correct interpretation of immunohistochemistry (IHC) assays and help to detect unsuccessful/suboptimal slides. We performed an audit of slides that were designated as being "failed" by the IHC laboratory (ie, laboratory-failed slides) of a large North American oncology and transplant center. All slides were run with on-slide controls. The study included analysis of only those failed slides where staining of both internal and external controls were unsuccessful/suboptimal in a period of 65 days. Failed slides were categorized based on the reason why the laboratory failed the slides. The study compared frequencies of failed slides across 9 automated stainers from 2 manufacturers and between class 1 and class 2 biomarkers. Distinction between "failed slides" and "false-negative/false-positive tests" is emphasized. The study included 22,234 IHC slides in the study period. Of those, 452 (2%) were designated as "failed" by the laboratory. Class 1 and class 2 tests showed failure rates of 0.8% and 9%, respectively. The most frequent reason for failed slides on one platform related to "no or weak staining," whereas the other had more failed slides due to "high signal-to-noise ratio" (P<0.0001, χ test). Although the slides were run in groups of the same as well as different IHC protocols, unsuccessful/suboptimal testing typically manifested as individual slides (92%) and not as groups of slides; this indicates that so-called "batch controls" are not suitable as controls for automated platforms. We conclude that in the era of automated IHC staining platforms, on-slide controls allow for the proper identification of IHC slides that should be failed by the IHC laboratory and represent a powerful tool for preventing the reporting of false-negative/false-positive tests.

  12. Measuring Luminescence Lifetime With Help of a DSP

    NASA Technical Reports Server (NTRS)

    Danielson, J. D. S.

    2009-01-01

    An instrument for measuring the lifetime of luminescence (fluorescence or phosphorescence) includes a digital signal processor (DSP) as the primary means of control, generation of excitation signals, and analysis of response signals. The DSP hardware in the present instrument makes it possible to switch among a variety of operating modes by making changes in software only.

  13. Active sliding between cytoplasmic microtubules.

    PubMed

    Koonce, M P; Tong, J; Euteneuer, U; Schliwa, M

    Microtubules are versatile cellular polymers that play a role in cell shape determination and mediate various motile processes such as ciliary and flagellar bending, chromosome movements and organelle transport. That a sliding microtubule mechanism can generate force has been demonstrated in highly ordered structures such as axonemes, and microtubule-based force generation almost certainly contributes to the function of mitotic and meiotic spindles. Most cytoplasmic microtubule arrays, however, do not exhibit the structural regularity of axonemes and some spindles, and often appear disorganized. Yet many cellular activities (such as shape changes during morphogenesis, axonal extension and spindle assembly) involve highly coordinated microtubule behaviour and possibly require force generated by an intermicrotubule sliding mechanism, or perhaps use sliding to move microtubules rapidly into a protrusion for stabilization. Here we show that active sliding between cytoplasmic microtubules can occur in microtubule bundles of the amoeba Reticulomyxa. A force-producing mechanism of this sort could be used by this organism to facilitate the extension of cell processes and to generate the dynamic movements of the cytoplasmic network.

  14. Expression of the bacterial type III effector DspA/E in Saccharomyces cerevisiae down-regulates the sphingolipid biosynthetic pathway leading to growth arrest.

    PubMed

    Siamer, Sabrina; Guillas, Isabelle; Shimobayashi, Mitsugu; Kunz, Caroline; Hall, Michael N; Barny, Marie-Anne

    2014-06-27

    Erwinia amylovora, the bacterium responsible for fire blight, relies on a type III secretion system and a single injected effector, DspA/E, to induce disease in host plants. DspA/E belongs to the widespread AvrE family of type III effectors that suppress plant defense responses and promote bacterial growth following infection. Ectopic expression of DspA/E in plant or in Saccharomyces cerevisiae is toxic, indicating that DspA/E likely targets a cellular process conserved between yeast and plant. To unravel the mode of action of DspA/E, we screened the Euroscarf S. cerevisiae library for mutants resistant to DspA/E-induced growth arrest. The most resistant mutants (Δsur4, Δfen1, Δipt1, Δskn1, Δcsg1, Δcsg2, Δorm1, and Δorm2) were impaired in the sphingolipid biosynthetic pathway. Exogenously supplied sphingolipid precursors such as the long chain bases (LCBs) phytosphingosine and dihydrosphingosine also suppressed the DspA/E-induced yeast growth defect. Expression of DspA/E in yeast down-regulated LCB biosynthesis and induced a rapid decrease in LCB levels, indicating that serine palmitoyltransferase (SPT), the first and rate-limiting enzyme of the sphingolipid biosynthetic pathway, was repressed. SPT down-regulation was mediated by dephosphorylation and activation of Orm proteins that negatively regulate SPT. A Δcdc55 mutation affecting Cdc55-PP2A protein phosphatase activity prevented Orm dephosphorylation and suppressed DspA/E-induced growth arrest. © 2014 by The American Society for Biochemistry and Molecular Biology, Inc.

  15. Modular version of SIMCON, FPGA based, DSP integrated, LLRF control system for TESLA FEL part I: SIMCON 3.0 motherboard

    NASA Astrophysics Data System (ADS)

    Pozniak, Krzysztof T.; Romaniuk, Ryszard S.; Kierzkowski, Krzysztof

    2006-03-01

    The paper includes a description of predicted functionalities to be implemented in a universal motherboard (MB) for the next generation of LLRF control system for TESLA. The motherboard bases on a number of quasi-autonomous embedded executive modules. The modules are implemented in a few FPGA chips featured by the MB. The paper presents a practical design of the MB. The initial (basic) solution of the MB has the Cyclone as the chip where the board management is embedded. The board features communication modules - VME and micro, single chip PC with Ethernet. The board provides power supply for the FPGA chips. The board has fast internal communication between particular modules. The described Motherboard serves for experiments with the SIMCON 3.0 system.

  16. WTP Pretreatment Facility Potential Design Deficiencies--Sliding Bed and Sliding Bed Erosion Assessment

    SciTech Connect

    Hansen, E. K.

    2015-05-06

    This assessment is based on readily available literature and discusses both Newtonian and non-Newtonian slurries with respect to sliding beds and erosion due to sliding beds. This report does not quantify the size of the sliding beds or erosion rates due to sliding beds, but only assesses if they could be present. This assessment addresses process pipelines in the Pretreatment (PT) facility and the high level waste (HLW) transfer lines leaving the PT facility to the HLW vitrification facility concentrate receipt vessel.

  17. Design for slides.

    PubMed

    Johns, M

    1995-09-01

    The basic principles of design for projection slides are discussed, with particular reference to the impact of the personal computer and commercial presentation software on the material that is destined to end up on the screen at meetings and in seminar rooms. While modern software can be a boon to the presenter, allowing simple creation of slides, it can also encourage some of the worst excesses. The keynote of the design of slides for educational purposes should be simplicity, and ways of achieving simple but effective results are described.

  18. A comparison between DSP and FPGA platforms for real-time imaging applications

    NASA Astrophysics Data System (ADS)

    Shirvaikar, Mukul; Bushnaq, Tariq

    2009-02-01

    Real-time applications impose serious demands on hardware size, time deadlines, power dissipation, and cost of the solution. A typical system may also require modification of parameters during operation. Digital Signal Processors (DSPs) are a special class of microprocessors designed to specifically address real time implementation issues. As the complexity of real-time systems increases the need to introduce more efficient hardware platforms grows. In recent years Field Programmable Gate Arrays (FPGAs) have gained a lot of traction in the real-time community, as a replacement for the traditional DSP solutions. FPGAs are indeed revolutionizing image and signal processing due to their advanced capabilities such as reconfigurability. The Discrete Wavelet Transform is a classic real-time imaging algorithm that is drawing the attention of engineers in recent years. In this paper, we compare the FPGA implementation of 2-D liftingbased wavelet transform using optimized hand written VHDL code with a DSP implementation of the same algorithm using the C language. The goal of this paper is to compare the development effort and the performance of a traditional DSP processor to a FPGA based implementation of an image real-time application. The results of the experiment proves the superiority of FPGAs over traditional DSP processors in terms of time execution, power dissipation, and hardware utilization, nevertheless this advantage comes at the cost of a higher development effort. The hardware platform used is an Altera DE2 board with a 50MHz Cyclone II FPGA chip and a TI TMS320C6416 DSP Starter Kit (DSK).

  19. Maximum power point tracking algorithm based on sliding mode and fuzzy logic for photovoltaic sources under variable environmental conditions

    NASA Astrophysics Data System (ADS)

    Atik, L.; Petit, P.; Sawicki, J. P.; Ternifi, Z. T.; Bachir, G.; Della, M.; Aillerie, M.

    2017-02-01

    Solar panels have a nonlinear voltage-current characteristic, with a distinct maximum power point (MPP), which depends on the environmental factors, such as temperature and irradiation. In order to continuously harvest maximum power from the solar panels, they have to operate at their MPP despite the inevitable changes in the environment. Various methods for maximum power point tracking (MPPT) were developed and finally implemented in solar power electronic controllers to increase the efficiency in the electricity production originate from renewables. In this paper we compare using Matlab tools Simulink, two different MPP tracking methods, which are, fuzzy logic control (FL) and sliding mode control (SMC), considering their efficiency in solar energy production.

  20. High-contrast fluorescence imaging based on the polarization dependence of the fluorescence enhancement using an optical interference mirror slide.

    PubMed

    Yasuda, Mitsuru; Akimoto, Takuo

    2015-01-01

    High-contrast fluorescence imaging using an optical interference mirror (OIM) slide that enhances the fluorescence from a fluorophore located on top of the OIM surface is reported. To enhance the fluorescence and reduce the background light of the OIM, transverse-electric-polarized excitation light was used as incident light, and the transverse-magnetic-polarized fluorescence signal was detected. As a result, an approximate 100-fold improvement in the signal-to-noise ratio was achieved through a 13-fold enhancement of the fluorescence signal and an 8-fold reduction of the background light.

  1. Systems biology and clinical cytomics: The 10th Leipziger Workshop and the 3rd International Workshop on Slide-Based Cytometry, Leipzig, Germany, April 2005.

    PubMed

    Tárnok, Attila; Valet, Günther K; Emmrich, Frank

    2006-01-01

    Despite very significant technical and software improvements in flow cytometry (FCM) since the 1980's, the demand for a cytometric technology combining both quantitative cell analysis and morphological documentation in Cytomics became evident. Improvements in microtechnology and computing permit nowadays similar quantitative and stoichiometric single cell-based high-throughput analyses by microscopic instruments, like Slide-Based Cytometry (SBC). SBC and related techniques offer unique tools to perform complex immunophenotyping, thereby enabling diagnostic procedures during early disease stages. Multicolor or polychromatic analysis of cells by SBC is of special importance not only as a cytomics technology platform but also because of low quantities of required reagents and biological material. The exact knowledge of the location of each cell on the slide permits repetitive restaining and reanalysis of specimens. Various separate measurements of the same specimen can be ultimately fused to one database increasing the information obtained per cell. Relocation and optical evaluation of cells as typical SBC feature, can be of integral importance for cytometric analysis, since artifacts can be excluded and morphology of measured cells can be documented. Progress in cell analytic: In the SBC, new horizons can be opened by the new techniques of structural and functional analysis with the high resolution from intracellular and membrane (confocal microscopy, nanoscopy, total internal fluorescence microscopy (TIRFM), and tissue level (tissomics), to organ and organism level (in vivo cytometry, optical whole body imaging). Predictive medicine aims at the detection of changes in patient's state prior to the manifestation of the disease or the complication. Such instances concern immune consequences of surgeries or noninfectious posttraumatic shock in intensive care patients or the pretherapeutic identification of high risk patients in cancer cytostatic therapy. Preventive anti

  2. Implementation of aeronautic image compression technology on DSP

    NASA Astrophysics Data System (ADS)

    Wang, Yujing; Gao, Xueqiang; Wang, Mei

    2007-11-01

    According to the designed characteristics and demands of aeronautic image compression system, lifting scheme wavelet and SPIHT algorithm was selected as the key part of software implementation, which was introduced with details. In order to improve execution efficiency, border processing was simplified reasonably and SPIHT (Set Partitioning in Hierarchical Trees) algorithm was also modified partly. The results showed that the selected scheme has a 0.4dB improvement in PSNR(peak-peak-ratio) compared with classical Shaprio's scheme. To improve the operating speed, the hardware system was then designed based on DSP and many optimization measures were then applied successfully. Practical test showed that the system can meet the real-time demand with good quality of reconstruct image, which has been used in an aeronautic image compression system practically.

  3. Slides, Swings and Science.

    ERIC Educational Resources Information Center

    Dreyer, Kay Jardon; Bryte, Janelle

    1990-01-01

    Described are eight science activities that may take place on a school playground using a parachute, balls, swings, slides, and a balance beam. Procedures and questions for each activity are included. (CW)

  4. Fast combinatorial RNS processors for DSP applications

    SciTech Connect

    Di Claudio, E.D.; Piazza, F.; Orlandi, G.

    1995-05-01

    It is known that RNS VLSI processors can parallelize fixed-point addition and multiplication operations by the use of the Chinese Remainder Theorem (CRT). The required modular operations, however, must use specialized hardware whose design and implementation can create several problems. In this paper a modified residue arithmetic, called pseudo-RNS is introduced in order to alleviate some of the RNS problems when Digital Signal Processing (DSP) structures are implemented. Pseudo-RNS requires only the use of modified binary processors and exhibits a speed performance comparable with other RNS traditional approaches. Some applications of the pseudo-RNS to common DSP architectures, such as multipliers and filters, are also presented in this paper. They are compared in terms of the Area-Time Square product versus other RNS and weighted binary structures. It is proven that existing combinatorial or look-up table approaches for RNS are tailored to small designs or special applications, while the pseudo-RNS approach remains competitive also for complex systems. 32 refs.

  5. A new adjustable gains for second order sliding mode control of saturated DFIG-based wind turbine

    NASA Astrophysics Data System (ADS)

    Bounadja, E.; Djahbar, A.; Taleb, R.; Boudjema, Z.

    2017-02-01

    The control of Doubly-Fed induction generator (DFIG), used in wind energy conversion, has been given a great deal of interest. Frequently, this control has been dealt with ignoring the magnetic saturation effect in the DFIG model. The aim of the present work is twofold: firstly, the magnetic saturation effect is accounted in the control design model; secondly, a new second order sliding mode control scheme using adjustable-gains (AG-SOSMC) is proposed to control the DFIG via its rotor side converter. This scheme allows the independent control of the generated active and reactive power. Conventionally, the second order sliding mode control (SOSMC) applied to the DFIG, utilize the super-twisting algorithm with fixed gains. In the proposed AG-SOSMC, a simple means by which the controller can adjust its behavior is used. For that, a linear function is used to represent the variation in gain as a function of the absolute value of the discrepancy between the reference rotor current and its measured value. The transient DFIG speed response using the aforementioned characteristic is compared with the one determined by using the conventional SOSMC controller with fixed gains. Simulation results show, accurate dynamic performances, quicker transient response and more accurate control are achieved for different operating conditions.

  6. Simultaneous ATR-FTIR Based Determination of Malaria Parasitemia, Glucose and Urea in Whole Blood Dried onto a Glass Slide.

    PubMed

    Roy, Supti; Perez-Guaita, David; Andrew, Dean W; Richards, Jack S; McNaughton, Don; Heraud, Philip; Wood, Bayden R

    2017-05-16

    New diagnostic tools that can detect malaria parasites in conjunction with other diagnostic parameters are urgently required. In this study, Attenuated Total Reflection Fourier transform infrared (ATR-FTIR) spectroscopy in combination with Partial Least Square Discriminant Analysis (PLS-DA) and Partial Least Square Regression (PLS-R) have been applied as a point-of-care test for identifying malaria parasites, blood glucose, and urea levels in whole blood samples from thick blood films on glass slides. The specificity for the PLS-DA was found to be 98% for parasitemia levels >0.5%, but a rather low sensitivity of 70% was achieved because of the small number of negative samples in the model. In PLS-R the Root Mean Square Error of Cross Validation (RMSECV) for parasite concentration (0-5%) was 0.58%. Similarly, for glucose (0-400 mg/dL) and urea (0-250 mg/dL) spiked samples, relative RMSECVs were 16% and 17%, respectively. The method reported here is the first example of multianalyte/disease diagnosis using ATR-FTIR spectroscopy, which in this case, enabled the simultaneous quantification of glucose and urea analytes along with malaria parasitemia quantification using one spectrum obtained from a single drop of blood on a glass microscope slide.

  7. Prototype Slide Stainer

    NASA Technical Reports Server (NTRS)

    1971-01-01

    The prototype slide staining system capable of performing both one-component Wright's staining of blood smears and eight-step Gram staining of heat fixed slides of microorganisms is described. Attention was given to liquid containment, waste handling, absence of contamination from previous staining, and stability of the staining reagents. The unit is self-contained, capable of independent operation under one- or zero-g conditions, and compatible with Skylab A.

  8. An updated nuclear criticality slide rule

    SciTech Connect

    Hopper, C.M.; Broadhead, B.L.

    1998-04-01

    This Volume 2 contains the functional version of the updated nuclear criticality slide rule (more accurately, sliding graphs) that is referenced in An Updated Nuclear Criticality Slide Rule: Technical Basis, NUREG/CR-6504, Vol. 1 (ORNL/TM-13322/V1). This functional slide rule provides a readily usable {open_quotes}in-hand{close_quotes} method for estimating pertinent nuclear criticality accident information from sliding graphs, thereby permitting (1) the rapid estimation of pertinent criticality accident information without laborious or sophisticated calculations in a nuclear criticality emergency situation, (2) the appraisal of potential fission yields and external personnel radiation exposures for facility safety analyses, and (3) a technical basis for emergency preparedness and training programs at nonreactor nuclear facilities. The slide rule permits the estimation of neutron and gamma dose rates and integrated doses based upon estimated fission yields, distance from the fission source, and time-after criticality accidents for five different critical systems. Another sliding graph permits the estimation of critical solution fission yields based upon fissile material concentration, critical vessel geometry, and solution addition rate. Another graph provides neutron and gamma dose-reduction factors for water, steel, and concrete. Graphs from historic documents are provided as references for estimating critical parameters of various fissile material systems. Conversion factors for various English and metric units are provided for quick reference.

  9. Modeling of Block-Based DSP Systems

    DTIC Science & Technology

    2006-01-01

    4. 4. EXPERIMENTS We have prototyped a preliminary version of BLDF semantics in Ptolemy II [7], a widely-used tool for developing and integrating...models of computation. 4.1 MPEG2 Video encoder implementation We have implemented an MPEG2 Video encoder under the Ptolemy II environment in three dif...SDF and FSM, in a heterogeneous and hierarchical way, using the heterogeneous modeling capabilities of Ptolemy II. Figure 4 illustrates our

  10. Pullout behavior of steel fibers from cement-based composites

    SciTech Connect

    Shannag, M.J.; Brincker, R.; Hansen, W.

    1997-06-01

    A comprehensive experimental program on pullout tests of steel fibers from cement based matrices is described. A specially designed single fiber pullout apparatus was used to provide a quantitative determination of interfacial properties that are relevant to toughening brittle materials through fiber reinforcement. The parameters investigated included a specially designed high strength cement based matrix called Densified Small Particles system (DSP), a conventional mortar matrix, fiber embedment length, and the fiber volume fraction. The mediums from which the fiber was pulled included a control mortar mix without fibers, a mortar mix with 3, and 6 percent fibers by volume. The results indicate that: (1) the dense DSP matrix has significantly improved interfacial properties as compared to the conventional mortar matrix. (2) Increasing the fiber embedment length and the fiber volume fraction in the cement matrix increase the peak pullout load and the pullout work. (3) The major bond mechanism in both systems is frictional sliding.

  11. Web-Based Virtual Microscopy of Digitized Blood Slides for Malaria Diagnosis: An Effective Tool for Skills Assessment in Different Countries and Environments

    PubMed Central

    Seal, Leonard H; Ainley, Carol; De la Salle, Barbara; Brereton, Michelle; Hyde, Keith; Burthem, John; Gilmore, William Samuel

    2016-01-01

    Background Morphological examination of blood films remains the reference standard for malaria diagnosis. Supporting the skills required to make an accurate morphological diagnosis is therefore essential. However, providing support across different countries and environments is a substantial challenge. Objective This paper reports a scheme supplying digital slides of malaria-infected blood within an Internet-based virtual microscope environment to users with different access to training and computing facilities. The feasibility of the approach was established, allowing users to test, record, and compare their own performance with that of other users. Methods From Giemsa stained thick and thin blood films, 56 large high-resolution digital slides were prepared, using high-quality image capture and 63x oil-immersion objective lens. The individual images were combined using the photomerge function of Adobe Photoshop and then adjusted to ensure resolution and reproduction of essential diagnostic features. Web delivery employed the Digital Slidebox platform allowing digital microscope viewing facilities and image annotation with data gathering from participants. Results Engagement was high with images viewed by 38 participants in five countries in a range of environments and a mean completion rate of 42/56 cases. The rate of parasite detection was 78% and accuracy of species identification was 53%, which was comparable with results of similar studies using glass slides. Data collection allowed users to compare performance with other users over time or for each individual case. Conclusions Overall, these results demonstrate that users worldwide can effectively engage with the system in a range of environments, with the potential to enhance personal performance through education, external quality assessment, and personal professional development, especially in regions where educational resources are difficult to access. PMID:27515009

  12. Web-Based Virtual Microscopy of Digitized Blood Slides for Malaria Diagnosis: An Effective Tool for Skills Assessment in Different Countries and Environments.

    PubMed

    Ahmed, Laura; Seal, Leonard H; Ainley, Carol; De la Salle, Barbara; Brereton, Michelle; Hyde, Keith; Burthem, John; Gilmore, William Samuel

    2016-08-11

    Morphological examination of blood films remains the reference standard for malaria diagnosis. Supporting the skills required to make an accurate morphological diagnosis is therefore essential. However, providing support across different countries and environments is a substantial challenge. This paper reports a scheme supplying digital slides of malaria-infected blood within an Internet-based virtual microscope environment to users with different access to training and computing facilities. The feasibility of the approach was established, allowing users to test, record, and compare their own performance with that of other users. From Giemsa stained thick and thin blood films, 56 large high-resolution digital slides were prepared, using high-quality image capture and 63x oil-immersion objective lens. The individual images were combined using the photomerge function of Adobe Photoshop and then adjusted to ensure resolution and reproduction of essential diagnostic features. Web delivery employed the Digital Slidebox platform allowing digital microscope viewing facilities and image annotation with data gathering from participants. Engagement was high with images viewed by 38 participants in five countries in a range of environments and a mean completion rate of 42/56 cases. The rate of parasite detection was 78% and accuracy of species identification was 53%, which was comparable with results of similar studies using glass slides. Data collection allowed users to compare performance with other users over time or for each individual case. Overall, these results demonstrate that users worldwide can effectively engage with the system in a range of environments, with the potential to enhance personal performance through education, external quality assessment, and personal professional development, especially in regions where educational resources are difficult to access.

  13. Fundamentals of the Slide Library.

    ERIC Educational Resources Information Center

    Boerner, Susan Zee

    This paper is an introduction to the fundamentals of the art (including architecture) slide library, with some emphasis on basic procedures of the science slide library. Information in this paper is particularly relevant to the college, university, and museum slide library. Topics addressed include: (1) history of the slide library; (2) duties of…

  14. Selected Landscape Plants. Slide Script.

    ERIC Educational Resources Information Center

    McCann, Kevin

    This slide script, part of a series of slide scripts designed for use in vocational agriculture classes, deals with commercially important woody ornamental landscape plants. Included in the script are narrations for use with a total of 253 slides illustrating 92 different plants. Several slides are used to illustrate each plant: besides a view of…

  15. Ornamental Landscape Grasses. Slide Script.

    ERIC Educational Resources Information Center

    Still, Steven M.; Adams, Denise W.

    This slide script to accompany the slide series, Ornamental Landscape Grasses, contains photographs of the 167 slides and accompanying narrative text intended for use in the study and identification of commercially important ornamental grasses and grasslike plants. Narrative text is provided for slides of 62 different perennial and annual species…

  16. Ornamental Landscape Grasses. Slide Script.

    ERIC Educational Resources Information Center

    Still, Steven M.; Adams, Denise W.

    This slide script to accompany the slide series, Ornamental Landscape Grasses, contains photographs of the 167 slides and accompanying narrative text intended for use in the study and identification of commercially important ornamental grasses and grasslike plants. Narrative text is provided for slides of 62 different perennial and annual species…

  17. Decentralized Sliding Mode Observer Based Dual Closed-Loop Fault Tolerant Control for Reconfigurable Manipulator against Actuator Failure.

    PubMed

    Zhao, Bo; Li, Chenghao; Liu, Derong; Li, Yuanchun

    2015-01-01

    This paper considers a decentralized fault tolerant control (DFTC) scheme for reconfigurable manipulators. With the appearance of norm-bounded failure, a dual closed-loop trajectory tracking control algorithm is proposed on the basis of the Lyapunov stability theory. Characterized by the modularization property, the actuator failure is estimated by the proposed decentralized sliding mode observer (DSMO). Moreover, the actuator failure can be treated in view of the local joint information, so its control performance degradation is independent of other normal joints. In addition, the presented DFTC scheme is significantly simplified in terms of the structure of the controller due to its dual closed-loop architecture, and its feasibility is highly reflected in the control of reconfigurable manipulators. Finally, the effectiveness of the proposed DFTC scheme is demonstrated using simulations.

  18. Decentralized Sliding Mode Observer Based Dual Closed-Loop Fault Tolerant Control for Reconfigurable Manipulator against Actuator Failure

    PubMed Central

    Zhao, Bo; Li, Yuanchun

    2015-01-01

    This paper considers a decentralized fault tolerant control (DFTC) scheme for reconfigurable manipulators. With the appearance of norm-bounded failure, a dual closed-loop trajectory tracking control algorithm is proposed on the basis of the Lyapunov stability theory. Characterized by the modularization property, the actuator failure is estimated by the proposed decentralized sliding mode observer (DSMO). Moreover, the actuator failure can be treated in view of the local joint information, so its control performance degradation is independent of other normal joints. In addition, the presented DFTC scheme is significantly simplified in terms of the structure of the controller due to its dual closed-loop architecture, and its feasibility is highly reflected in the control of reconfigurable manipulators. Finally, the effectiveness of the proposed DFTC scheme is demonstrated using simulations. PMID:26181826

  19. Full-order sliding mode control of uncertain chaos in a permanent magnet synchronous motor based on a fuzzy extended state observer

    NASA Astrophysics Data System (ADS)

    Chen, Qiang; Nan, Yu-Rong; Zheng, Heng-Huo; Ren, Xue-Mei

    2015-11-01

    A full-order sliding mode control based on a fuzzy extended state observer is proposed to control the uncertain chaos in the permanent magnet synchronous motor. Through a simple coordinate transformation, the chaotic PMSM model is transformed into the Brunovsky canonical form, which is more suitable for the controller design. Based on the fuzzy control theory, a fuzzy extended state observer is developed to estimate the unknown states and uncertainties, and the restriction that all the system states should be completely measurable is avoided. Thereafter, a full-order sliding mode controller is designed to ensure the convergence of all system states without any chattering problem. Comparative simulations show the effectiveness and superior performance of the proposed control method. Project supported by the National Natural Science Foundation of China (Grant Nos. 61403343 and 61433003), the Scientific Research Foundation of Education Department of Zhejiang Province, China (Grant No. Y201329260), and the Natural Science Foundation of Zhejiang University of Technology, China (Grant No. 1301103053408).

  20. Development of New European VLIW Space DSP ASICS, IP Cores and Related Software via ESA Contracts in 2015 and Beyond

    NASA Astrophysics Data System (ADS)

    Trautner, R.

    2015-09-01

    European space industry needs a new generation of payload data processors in order to cope with in-creasing payload data processing requirements. ESA has defined a roadmap for the development of future payload processor hardware which is being implemented. A key part of this roadmap addresses the development of VLIW Digital Signal Processor (DSP) ASICs, IP cores and associated software. In this paper, we first present an overview of the ESA roadmap and the key development routes. We recapitulate the activities that have created the technology base for the ongoing DSP development, and present the ASIC development and several accompanying activities that will lead to the availability of a new space qualified DSP - the Scalable Sensor Data Processor (SSDP) - in the near future. We then present the expected future evolution of this technology area, and summarize the corresponding ESA roadmap part on VLIW DSPs and related IP and software.

  1. Robust motion estimation on a low-power multi-core DSP

    NASA Astrophysics Data System (ADS)

    Igual, Francisco D.; Botella, Guillermo; García, Carlos; Prieto, Manuel; Tirado, Francisco

    2013-12-01

    This paper addresses the efficient implementation of a robust gradient-based optical flow model in a low-power platform based on a multi-core digital signal processor (DSP). The aim of this work was to carry out a feasibility study on the use of these devices in autonomous systems such as robot navigation, biomedical assistance, or tracking, with not only power restrictions but also real-time requirements. We consider the C6678 DSP from Texas Instruments (Dallas, TX, USA) as the target platform of our implementation. The interest of this research is particularly relevant in optical flow scope because this system can be considered as an alternative solution for mid-range video resolutions when a combination of in-processor parallelism with optimizations such as efficient memory-hierarchy exploitation and multi-processor parallelization are applied.

  2. Expression profiling of a diapause-specific peptide (DSP) of the leaf beetle Gastrophysa atrocyanea and silencing of DSP by double-strand RNA.

    PubMed

    Tanaka, Hiromasa; Suzuki, Koichi

    2005-06-01

    A diapause-specific peptide (DSP) composed of 41 amino acid residues including 6 cysteines, has been isolated from diapausing adults of the leaf beetle Gastrophysa atrocyanea. In this study, DSP was found to be expressed primarily in diapausing adults and to a minor extent in pupae, but not in eggs, larvae, or post-diapausing adults. DSP was not induced by bacterial or fungal challenge. DSP-less adults were generated by the injection of double-stranded RNA (dsRNA) corresponding to the dsp gene into pre-diapausing adults. Gene silencing induced by dsRNA was found to be a useful tool for the analysis of DSP in diapausing adults. DSP-less adults showed similar burrowing behavior and oxygen consumption as control insects suggesting that DSP is not essential for the normal onset and maintenance of diapause.

  3. A multi-DSP system for the neutron high resolution Fourier diffractometer

    SciTech Connect

    Drozdov, V.A.; Butenko, V.A.; Prikhodko, V.I.

    1998-08-01

    The multi-DSP data acquisition system for neutron time-of-flight spectrum measurements requiring fast real-time data processing is designed and is operated at the neutron High Resolution Fourier Diffractometer (HRFD). The use of high performance DSPs and front-end electronics based on flexible PLDs allows increasing of the efficiency of neutron diffractometers with a Fourier chopper and a multi-element detector system by the method of electronic time-focusing.

  4. Fuzzy fractional order sliding mode controller for nonlinear systems

    NASA Astrophysics Data System (ADS)

    Delavari, H.; Ghaderi, R.; Ranjbar, A.; Momani, S.

    2010-04-01

    In this paper, an intelligent robust fractional surface sliding mode control for a nonlinear system is studied. At first a sliding PD surface is designed and then, a fractional form of these networks PDα, is proposed. Fast reaching velocity into the switching hyperplane in the hitting phase and little chattering phenomena in the sliding phase is desired. To reduce the chattering phenomenon in sliding mode control (SMC), a fuzzy logic controller is used to replace the discontinuity in the signum function at the reaching phase in the sliding mode control. For the problem of determining and optimizing the parameters of fuzzy sliding mode controller (FSMC), genetic algorithm (GA) is used. Finally, the performance and the significance of the controlled system two case studies (robot manipulator and coupled tanks) are investigated under variation in system parameters and also in presence of an external disturbance. The simulation results signify performance of genetic-based fuzzy fractional sliding mode controller.

  5. Symmetric caging formation for convex polygonal object transportation by multiple mobile robots based on fuzzy sliding mode control.

    PubMed

    Dai, Yanyan; Kim, YoonGu; Wee, SungGil; Lee, DongHa; Lee, SukGyu

    2016-01-01

    In this paper, the problem of object caging and transporting is considered for multiple mobile robots. With the consideration of minimizing the number of robots and decreasing the rotation of the object, the proper points are calculated and assigned to the multiple mobile robots to allow them to form a symmetric caging formation. The caging formation guarantees that all of the Euclidean distances between any two adjacent robots are smaller than the minimal width of the polygonal object so that the object cannot escape. In order to avoid collision among robots, the parameter of the robots radius is utilized to design the caging formation, and the A⁎ algorithm is used so that mobile robots can move to the proper points. In order to avoid obstacles, the robots and the object are regarded as a rigid body to apply artificial potential field method. The fuzzy sliding mode control method is applied for tracking control of the nonholonomic mobile robots. Finally, the simulation and experimental results show that multiple mobile robots are able to cage and transport the polygonal object to the goal position, avoiding obstacles.

  6. Short-term memory of TiO2-based electrochemical capacitors: empirical analysis with adoption of a sliding threshold

    NASA Astrophysics Data System (ADS)

    Lim, Hyungkwang; Kim, Inho; Kim, Jin-Sang; Hwang, Cheol Seong; Jeong, Doo Seok

    2013-09-01

    Chemical synapses are important components of the large-scaled neural network in the hippocampus of the mammalian brain, and a change in their weight is thought to be in charge of learning and memory. Thus, the realization of artificial chemical synapses is of crucial importance in achieving artificial neural networks emulating the brain’s functionalities to some extent. This kind of research is often referred to as neuromorphic engineering. In this study, we report short-term memory behaviours of electrochemical capacitors (ECs) utilizing TiO2 mixed ionic-electronic conductor and various reactive electrode materials e.g. Ti, Ni, and Cr. By experiments, it turned out that the potentiation behaviours did not represent unlimited growth of synaptic weight. Instead, the behaviours exhibited limited synaptic weight growth that can be understood by means of an empirical equation similar to the Bienenstock-Cooper-Munro rule, employing a sliding threshold. The observed potentiation behaviours were analysed using the empirical equation and the differences between the different ECs were parameterized.

  7. Design of miniature hybrid target recognition system with combination of FPGA+DSP

    NASA Astrophysics Data System (ADS)

    Luo, Shishang; Li, Xiujian; Jia, Hui; Hu, Wenhua; Nie, Yongming; Chang, Shengli

    2010-10-01

    With advantages of flexibility, high bandwidth, high spatial resolution and high-speed parallel operation, the opto-electronic hybrid target recognition system can be applied in many civil and military areas, such as video surveillance, intelligent navigation and robot vision. A miniature opto-electronic hybrid target recognition system based on FPGA+DSP is designed, which only employs single Fourier lens and with a focal length. With the precise timing control of the FPGA and images pretreatment of the DSP, the system performs both Fourier transform and inverse Fourier transform with all optical process, which can improve recognition speed and reduce the system volume remarkably. We analyzed the system performance, and a method to achieve scale invariant pattern recognition was proposed on the basis of lots of experiments.

  8. DSP algorithms for recovering single-carrier Alamouti coded signals for PON applications.

    PubMed

    Faruk, Md Saifuddin; Louchet, Hadrien; Erkılınç, M Sezer; Savory, Seb J

    2016-10-17

    Alamouti space-time block code (STBC) combined with a simple heterodyne coherent receiver enables phase diverse coherent detection without any optical polarization tracking. While such a system consisting of only a 3-dB coupler and a single balanced photodiode has been recently demonstrated using orthogonal frequency-division multiplexed (OFDM) signals, herein we report the first application to single-carrier systems. Applicability of such technique for single-carrier systems is not straightforward since specialized digital signal processing (DSP) algorithms are required for data recovery. In this paper, we address the implementing issues and DSP algorithms applicable for single-carrier (SC) Alamouti STBC based simplified heterodyne receivers. Polarization-insensitive operation of the proposed scheme and its performance are verified by means of simulation for a 12-Gbits/s quadrature phase-shift keying (QPSK) transmission system.

  9. A Test of the DSP Sexing Method on CT Images from a Modern French Sample.

    PubMed

    Mestekova, Sarka; Bruzek, Jaroslav; Veleminska, Jana; Chaumoitre, Kathia

    2015-09-01

    The hip bone is considered to be one of the most reliable indicators in sex determination. The aim of this study was to test the reliability of the DSP method for the hip bone proposed by Murail et al. (Bull Mem Soc Anthropol Paris, 17, 2005, 167) on a sample from a present-day population in France (52 males and 54 females). Ten linear measurements were collected from three-dimensional models derived from computed tomography images (CTI). To quantify the proportions of correct sex determinations, a more rigorous posterior probability threshold of 0.95 was applied. Using all 10 measurements, 92.3% of males and 97.2% of females were sexed correctly. The percentage of undetermined specimens varied depending on the used combination of measurements; however, all sexes were assigned with a 100% accuracy. This study proves that DSP is an appropriate and reliable tool for sex determination, based on dimensions obtained from CTI.

  10. Dominant de novo DSP mutations cause erythrokeratodermia-cardiomyopathy syndrome

    PubMed Central

    Boyden, Lynn M.; Kam, Chen Y.; Hernández-Martín, Angela; Zhou, Jing; Craiglow, Brittany G.; Sidbury, Robert; Mathes, Erin F.; Maguiness, Sheilagh M.; Crumrine, Debra A.; Williams, Mary L.; Hu, Ronghua; Lifton, Richard P.; Elias, Peter M.; Green, Kathleen J.; Choate, Keith A.

    2016-01-01

    Disorders of keratinization (DOK) show marked genotypic and phenotypic heterogeneity. In most cases, disease is primarily cutaneous, and further clinical evaluation is therefore rarely pursued. We have identified subjects with a novel DOK featuring erythrokeratodermia and initially-asymptomatic, progressive, potentially fatal cardiomyopathy, a finding not previously associated with erythrokeratodermia. We show that de novo missense mutations clustered tightly within a single spectrin repeat of DSP cause this novel cardio-cutaneous disorder, which we term erythrokeratodermia-cardiomyopathy (EKC) syndrome. We demonstrate that DSP mutations in our EKC syndrome subjects affect localization of desmosomal proteins and connexin 43 in the skin, and result in desmosome aggregation, widening of intercellular spaces, and lipid secretory defects. DSP encodes desmoplakin, a primary component of desmosomes, intercellular adhesion junctions most abundant in the epidermis and heart. Though mutations in DSP are known to cause other disorders, our cohort features the unique clinical finding of severe whole-body erythrokeratodermia, with distinct effects on localization of desmosomal proteins and connexin 43. These findings add a severe, previously undescribed syndrome featuring erythrokeratodermia and cardiomyopathy to the spectrum of disease caused by mutation in DSP, and identify a specific region of the protein critical to the pathobiology of EKC syndrome and to DSP function in the heart and skin. PMID:26604139

  11. Dominant de novo DSP mutations cause erythrokeratodermia-cardiomyopathy syndrome.

    PubMed

    Boyden, Lynn M; Kam, Chen Y; Hernández-Martín, Angela; Zhou, Jing; Craiglow, Brittany G; Sidbury, Robert; Mathes, Erin F; Maguiness, Sheilagh M; Crumrine, Debra A; Williams, Mary L; Hu, Ronghua; Lifton, Richard P; Elias, Peter M; Green, Kathleen J; Choate, Keith A

    2016-01-15

    Disorders of keratinization (DOK) show marked genotypic and phenotypic heterogeneity. In most cases, disease is primarily cutaneous, and further clinical evaluation is therefore rarely pursued. We have identified subjects with a novel DOK featuring erythrokeratodermia and initially-asymptomatic, progressive, potentially fatal cardiomyopathy, a finding not previously associated with erythrokeratodermia. We show that de novo missense mutations clustered tightly within a single spectrin repeat of DSP cause this novel cardio-cutaneous disorder, which we term erythrokeratodermia-cardiomyopathy (EKC) syndrome. We demonstrate that DSP mutations in our EKC syndrome subjects affect localization of desmosomal proteins and connexin 43 in the skin, and result in desmosome aggregation, widening of intercellular spaces, and lipid secretory defects. DSP encodes desmoplakin, a primary component of desmosomes, intercellular adhesion junctions most abundant in the epidermis and heart. Though mutations in DSP are known to cause other disorders, our cohort features the unique clinical finding of severe whole-body erythrokeratodermia, with distinct effects on localization of desmosomal proteins and connexin 43. These findings add a severe, previously undescribed syndrome featuring erythrokeratodermia and cardiomyopathy to the spectrum of disease caused by mutation in DSP, and identify a specific region of the protein critical to the pathobiology of EKC syndrome and to DSP function in the heart and skin.

  12. Slowing the Summer Slide

    ERIC Educational Resources Information Center

    Smith, Lorna

    2012-01-01

    Research shows that summer slide--the loss of learning over the summer break--is a huge contributor to the achievement gap between low-income students and their higher-income peers. In fact, some researchers have concluded that two-thirds of the 9th-grade reading achievement gap can be explained by unequal access to summer learning opportunities…

  13. Black and White Slides.

    ERIC Educational Resources Information Center

    Tanner, Jackie

    1979-01-01

    Outlines procedures for using some photographic techniques to start a black and white slide collection. Instructions are given for: (1) necessary equipment and materials; (2) photographing images such as photos, charts or drawings; (3) developing the film; and (4) setting up the filing system. Photographs and drawings illustrate the process. (AMH)

  14. A magnetorheological damper-based prosthetic knee (MRPK) and sliding mode tracking control method for an MRPK-based lower limb prosthesis

    NASA Astrophysics Data System (ADS)

    Fu, Qiang; Wang, Dai-Hua; Xu, Lei; Yuan, Gang

    2017-04-01

    Based on a two-bar linkage and a magnetorheological damper (MRD) with a double-ended structure and shearing operation mode of the magnetorheological fluid, an MRD-based prosthetic knee (MRPK) is realized. Utilizing the developed MRPK, an MRD-based lower limb prosthesis (MRLLP) is developed, modeled, and simulated in this paper, to analyse the effects of hysteresis of the integrated MRD on the swing angle of the shank of the MRLLP. Based on this, a sliding mode tracking control (SMTC) method for controlling the swing angle of the shank of the MRLLP is proposed to suppress hysteresis, along with a robustness analysis. Utilizing the SMTC method, co-simulations on controlling the swing angle of the shank of the MRLLP are carried out in ADAMS and Simulink. The simulation results show that the root mean square error (RMSE) of the swing angle of the shank of the MRLLP produced by the SMTC method is 80% less than that from the computed torque plus PD (CT+PD) control method. Therefore, the SMTC method is effective in suppressing hysteresis of the MRD. Furthermore, when the MRLLP is disturbed, the RMSE of the swing angle of the shank of the MRLLP produced by the SMTC method is 67% less than that from the CT+PD control method. Therefore, the SMTC method has strong robustness to random disturbance. A rapid control prototype of the MRLLP system and a corresponding experimental test system are established. On the established experimental test system, experiments are carried out on control of the swing angle of the shank of the MRLLP via the SMTC method. The results are compared with those from the ON/OFF and the CT+PD control methods. The experimental results show that the MRPK has controllable joint torque, and can be used to imitate the natural swing of a human knee joint. Additionally, the RMSE of the controlled swing angle of the shank of the MRLLP produced by the SMTC method is 34% less than that produced by the CT+PD control method and is 37% less than that from the ON

  15. The optimization of improved mean shift object tracking in embedded multicore DSP parallel system

    NASA Astrophysics Data System (ADS)

    Tian, Li; Zhou, Fugen; Meng, Cai; Hu, Congliang

    2014-11-01

    This paper proposes a more robust and efficient Mean Shift object tracking algorithm which is optimized for embedded multicore DSP Parallel system. Firstly, the RGB image is transformed into HSV image which is robust in many aspects such as lighting changes. Then, the color histogram model is used in the back projection process to generate the color probability distribution. Secondly, the size and position of search window are initialized in the first frame, and Mean Shift algorithm calculates the center position of the target and adjusts the search window automatically both in size and location, according to the result of the previous frame. Finally, since the multicore DSP system is commonly adopted in the embedded application such as seeker and an optical scout system, we implement the proposed algorithm in the TI multicore DSP system to meet the need of large amount computation. For multicore parallel computing, the explicit IPC based multicore framework is designed which outperforms OpenMP standard. Moreover, the parallelisms of 8 functional units and cross path data fetch capability of C66 core are utilized to accelerate the computation of iteration in Mean Shift algorithm. The experimental results show that the algorithm has good performance in complex scenes such as deformation, scale change and occlusion, simultaneously the proposed optimization method can significantly reduce the computation time.

  16. Implementation Considerations for Automotive Vision Systems on a Fixed-Point DSP

    NASA Astrophysics Data System (ADS)

    Nikolić, Zoran

    In this chapter we evaluate numerical requirements for implementation of camera-based lateral position detection algorithms, such as lane keep assistant (LKA) and lane departure warning (LDW) on a fixed-point DSP. We first present methods that address the challenges and requirements of fixed-point design process. The flow proposed is targeted at converting C/C++ code with floating-point operations into C code with integer operations that can then be fed through the native C compiler for a fixed-point DSP. Advanced code optimization and an implementation by DSP-specific, fixed-point C code generation are introduced. We then demonstrate the conversion flow on tracking example (extended Kalman filter) using synthetically generated data, and we analyze trade-offs for algorithm implementation in fixed-point arithmetic. By using the techniques described in this chapter speed can be increased by a factor of up to 10 compared to floating-point emulation on fixed-point hardware.

  17. Validation of diagnostic accuracy using digital slides in routine histopathology.

    PubMed

    Fónyad, László; Krenács, Tibor; Nagy, Péter; Zalatnai, Attila; Csomor, Judit; Sápi, Zoltán; Pápay, Judit; Schönléber, Júlia; Diczházi, Csaba; Molnár, Béla

    2012-03-31

    Robust hardware and software tools have been developed in digital microscopy during the past years for pathologists. Reports have been advocated the reliability of digital slides in routine diagnostics. We have designed a retrospective, comparative study to evaluate the scanning properties and digital slide based diagnostic accuracy. 8 pathologists reevaluated 306 randomly selected cases from our archives. The slides were scanned with a 20× Plan-Apochromat objective, using a 3-chip Hitachi camera, resulting 0.465 μm/pixel resolution. Slide management was supported with dedicated Data Base and Viewer software tools. Pathologists used their office PCs for evaluation and reached the digital slides via intranet connection. The diagnostic coherency and uncertainty related to digital slides and scanning quality were analyzed. Good to excellent image quality of slides was recorded in 96%. In half of the critical 61 digital slides, poor image quality was related to section folds or floatings. In 88.2% of the studied cases the digital diagnoses were in full agreement with the consensus. Out of the overall 36 incoherent cases, 7 (2.3%) were graded relevant without any recorded uncertainty by the pathologist. Excluding the non-field specific cases from each pathologist's record this ratio was 1.76% of all cases. Our results revealed that: 1) digital slide based histopathological diagnoses can be highly coherent with those using optical microscopy; 2) the competency of pathologists is a factor more important than the quality of digital slide; 3) poor digital slide quality do not endanger patient safety as these errors are recognizable by the pathologist and further actions for correction could be taken. The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/1913324336747310.

  18. Preparing Slide Presentations on Computers.

    ERIC Educational Resources Information Center

    Elberfeld, John K.

    1982-01-01

    Suggest use of well-organized slide presentation as effective way to introduce computers to large audiences and discusses how to get started--state objective, analyze audience, outline presentation, prepare slides--and equipment needed to obtain slides from television screens, miniature components, and book illustrations. References and sources…

  19. Conserved PCR primer set designing for closely-related species to complete mitochondrial genome sequencing using a sliding window-based PSO algorithm.

    PubMed

    Yang, Cheng-Hong; Chang, Hsueh-Wei; Ho, Chang-Hsuan; Chou, Yii-Cheng; Chuang, Li-Yeh

    2011-03-18

    Complete mitochondrial (mt) genome sequencing is becoming increasingly common for phylogenetic reconstruction and as a model for genome evolution. For long template sequencing, i.e., like the entire mtDNA, it is essential to design primers for Polymerase Chain Reaction (PCR) amplicons which are partly overlapping each other. The presented chromosome walking strategy provides the overlapping design to solve the problem for unreliable sequencing data at the 5' end and provides the effective sequencing. However, current algorithms and tools are mostly focused on the primer design for a local region in the genomic sequence. Accordingly, it is still challenging to provide the primer sets for the entire mtDNA. The purpose of this study is to develop an integrated primer design algorithm for entire mt genome in general, and for the common primer sets for closely-related species in particular. We introduce ClustalW to generate the multiple sequence alignment needed to find the conserved sequences in closely-related species. These conserved sequences are suitable for designing the common primers for the entire mtDNA. Using a heuristic algorithm particle swarm optimization (PSO), all the designed primers were computationally validated to fit the common primer design constraints, such as the melting temperature, primer length and GC content, PCR product length, secondary structure, specificity, and terminal limitation. The overlap requirement for PCR amplicons in the entire mtDNA is satisfied by defining the overlapping region with the sliding window technology. Finally, primer sets were designed within the overlapping region. The primer sets for the entire mtDNA sequences were successfully demonstrated in the example of two closely-related fish species. The pseudo code for the primer design algorithm is provided. In conclusion, it can be said that our proposed sliding window-based PSO algorithm provides the necessary primer sets for the entire mt genome amplification and

  20. A vector DSP for digital media processors

    NASA Astrophysics Data System (ADS)

    Bersack, Bret; Redford, John; Moniz, Matt; Goldman, Michael

    2003-05-01

    A new chip using a DSP with a novel vector architecture is described. It uses a Very Dense Instruction Word (rather than a VLIW) and exploits the parallelism and narrow data typical of image processing to gain high performance at low cost and power. It contains eight 32-bit datapaths all working off a single instruction, and can do sixteen 16-bit MACs per cycle or four 32-bit memory accesses per cycle to 128 KB of on-chip memory. It also contains a serial datapath for handling low-performance code and OS functions. The chip includes memory, video and IO interfaces on an industry-standard bus. It also includes camera-specific IO such as videos DACs for NTSC/PAL and analog LCDs, an I2S audio interface, and USB 1.1. It is built in 0.18 um CMOS, runs at 233 MHz, and draws 300 mW. It uses no fixed-function blocks, microcode, or coprocessors, but can capture and compress video at 30 fps at VGA resolution using JPEG, or at CIF resolution using MPEG-4.

  1. Sliding Luttinger liquid phases

    NASA Astrophysics Data System (ADS)

    Mukhopadhyay, Ranjan; Kane, C. L.; Lubensky, T. C.

    2001-07-01

    We study systems of coupled spin-gapped and gapless Luttinger liquids. First, we establish the existence of a sliding Luttinger liquid phase for a system of weakly coupled parallel quantum wires, with and without disorder. It is shown that the coupling can stabilize a Luttinger liquid phase in the presence of disorder. We then extend our analysis to a system of crossed Luttinger liquids and establish the stability of a non-Fermi-liquid state: the crossed sliding Luttinger liquid phase. In this phase the system exhibits a finite-temperature, long-wavelength, isotropic electric conductivity that diverges as a power law in temperature T as T-->0. This two-dimensional system has many properties of a true isotropic Luttinger liquid, though at zero temperature it becomes anisotropic. An extension of this model to a three-dimensional stack exhibits a much higher in-plane conductivity than the conductivity in a perpendicular direction.

  2. Reducing slide sheet injury.

    PubMed

    Varcin-Coad, Lynn

    2008-12-01

    Slide sheets are often stated to be the cause of hand and forearm injuries. While there are many other possible reasons injuries to nursing staff, carer and client occur, the most important linking factors relating to musculoskeletal disorders and manual handling of people is the ongoing inappropriateness or lack of suitably designed and equipped work areas. As physiotherapist Lynn Varcin-Coad writes, staff are bearing the brunt of inefficiencies of design and lack of high order risk control.

  3. Slide system for machine tools

    DOEpatents

    Douglass, S.S.; Green, W.L.

    1980-06-12

    The present invention relates to a machine tool which permits the machining of nonaxisymmetric surfaces on a workpiece while rotating the workpiece about a central axis of rotation. The machine tool comprises a conventional two-slide system (X-Y) with one of these slides being provided with a relatively short travel high-speed auxiliary slide which carries the material-removing tool. The auxiliary slide is synchronized with the spindle speed and the position of the other two slides and provides a high-speed reciprocating motion required for the displacement of the cutting tool for generating a nonaxisymmetric surface at a selected location on the workpiece.

  4. Slide system for machine tools

    DOEpatents

    Douglass, Spivey S.; Green, Walter L.

    1982-01-01

    The present invention relates to a machine tool which permits the machining of nonaxisymmetric surfaces on a workpiece while rotating the workpiece about a central axis of rotation. The machine tool comprises a conventional two-slide system (X-Y) with one of these slides being provided with a relatively short travel high-speed auxiliary slide which carries the material-removing tool. The auxiliary slide is synchronized with the spindle speed and the position of the other two slides and provides a high-speed reciprocating motion required for the displacement of the cutting tool for generating a nonaxisymmetric surface at a selected location on the workpiece.

  5. Chronic administration of DSP-7238, a novel, potent, specific and substrate-selective DPP IV inhibitor, improves glycaemic control and beta-cell damage in diabetic mice.

    PubMed

    Furuta, Y; Horiguchi, M; Sugaru, E; Ono-Kishino, M; Otani, M; Sakai, M; Masui, Y; Tsuchida, A; Sato, Y; Takubo, K; Hochigai, H; Kimura, H; Nakahira, H; Nakagawa, T; Taiji, M

    2010-05-01

    The purpose of this study is to assess the in vitro enzyme inhibition profile of DSP-7238, a novel non-cyanopyrrolidine dipeptidyl peptidase (DPP) IV inhibitor and to evaluate the acute and chronic effects of this compound on glucose metabolism in two different mouse models of type 2 diabetes. The in vitro enzyme inhibition profile of DSP-7238 was assessed using plasma and recombinant enzymes including DPP IV, DPP II, DPP8, DPP9 and fibroblast activation protein alpha (FAPalpha) with fluorogenic substrates. The inhibition type was evaluated based on the Lineweaver-Burk plot. Substrate selectivity of DSP-7238 and comparator DPP IV inhibitors (vildagliptin, sitagliptin, saxagliptin and linagliptin) was evaluated by mass spectrometry based on the changes in molecular weight of peptide substrates caused by release of N-terminal dipeptides. In the in vivo experiments, high-fat diet-induced obese (DIO) mice were subjected to oral glucose tolerance test (OGTT) following a single oral administration of DSP-7238. To assess the chronic effects of DSP-7238 on glycaemic control and pancreatic beta-cell damage, DSP-7238 was administered for 11 weeks to mice made diabetic by a combination of high-fat diet (HFD) and a low-dose of streptozotocin (STZ). After the dosing period, HbA1c was measured and pancreatic damage was evaluated by biological and histological analyses. DSP-7238 and sitagliptin both competitively inhibited recombinant human DPP IV (rhDPP IV) with K(i) values of 0.60 and 2.1 nM respectively. Neither vildagliptin nor saxagliptin exhibited competitive inhibition of rhDPP IV. DSP-7238 did not inhibit DPP IV-related enzymes including DPP8, DPP9, DPP II and FAPalpha, whereas vildagliptin and saxagliptin showed inhibition of DPP8 and DPP9. Inhibition of glucagon-like peptide-1 (GLP-1) degradation by DSP-7238 was apparently more potent than its inhibition of chemokine (C-X-C motif) ligand 10 (IP-10) or chemokine (C-X-C motif) ligand 12 (SDF-1alpha) degradation. In

  6. Teaching Challenge in Hands-on DSP Experiments for Night-School Students

    NASA Astrophysics Data System (ADS)

    Wu, Hsien-Tsai; Kuo, Sen M.

    2008-12-01

    The rapid increase in digital signal processing (DSP) applications has generated a strong demand for electrical engineers with DSP backgrounds; however, the gap between industry needs and university curricula still exists. To answer this challenge, a sequence of innovative DSP courses that emphasize hands-on experiments and practical applications were developed for continuing education in electrical and computer engineering. These courses are taught in the evening for night-school students having at least three years of work experience. These courses enable students to experiment with sophisticated DSP applications to augment the theoretical, conceptual, and analytical materials provided in traditional DSP courses. The inclusion of both software and hardware developments allows students to undertake a wide range of DSP projects for real-world applications. Assessment data concludes that the digital signal processor fundamentals course can increase learning interest and overcome the prerequisite problem of DSP laboratory experiments. This paper also briefly introduces representative examples of some challenging DSP applications.

  7. Theory of sliding-mode triboelectric nanogenerators.

    PubMed

    Niu, Simiao; Liu, Ying; Wang, Sihong; Lin, Long; Zhou, Yu Sheng; Hu, Youfan; Wang, Zhong Lin

    2013-11-20

    The triboelectric nanogenerator (TENG) is a powerful approach toward new energy technology, especially for portable electronics. A theoretical model for the sliding-mode TENG is presented in this work. The finite element method was utilized to characterize the distributions of electric potential, electric field, and charges on the metal electrodes of the TENG. Based on the FEM calculation, the semi-analytical results from the interpolation method and the analytical V-Q-x relationship are built to study the sliding-mode TENG. The analytical V-Q-x equation is validated through comparison with the semi-analytical results. Furthermore, based on the analytical V-Q-x equation, dynamic output performance of sliding-mode TENG is calculated with arbitrary load resistance, and good agreement with experimental data is achieved. The theory presented here is a milestone work for in-depth understanding of the working mechanism of the sliding-mode TENG, and provides a theoretical basis for further enhancement of the sliding-mode TENG for both energy scavenging and self-powered sensor applications.

  8. Optimal second order sliding mode control for linear uncertain systems.

    PubMed

    Das, Madhulika; Mahanta, Chitralekha

    2014-11-01

    In this paper an optimal second order sliding mode controller (OSOSMC) is proposed to track a linear uncertain system. The optimal controller based on the linear quadratic regulator method is designed for the nominal system. An integral sliding mode controller is combined with the optimal controller to ensure robustness of the linear system which is affected by parametric uncertainties and external disturbances. To achieve finite time convergence of the sliding mode, a nonsingular terminal sliding surface is added with the integral sliding surface giving rise to a second order sliding mode controller. The main advantage of the proposed OSOSMC is that the control input is substantially reduced and it becomes chattering free. Simulation results confirm superiority of the proposed OSOSMC over some existing.

  9. Integrated DSP/RF design for an MSAT transmitter

    NASA Technical Reports Server (NTRS)

    Stapleton, S. P.; Cavers, J. K.

    1990-01-01

    In mobile radio systems, the relatively inefficient use of the spectrum by existing Frequency Modulation (FM) techniques is limiting the available channels. Linear modulation methods are thought to provide the necessary push into more efficient usage of the spectrum. The limitation, to date, of the linear modulation techniques is the fact that the nonlinear power amplifier tends to spread the spectrum and thus offset any spectrum efficiency advantage. Linearization techniques are presently being investigated, in the literature, in order to recover some of the lost spectrum, due to spreading. To this end, digital signal processing (DSP) techniques are thought to provide real time predistortion methods. Some of the complex modulation blocks, normally confined to analog circuitry, are being implemented using DSP circuitry. This paper will address the linearization techniques, for mobile satellite (MSAT) transceivers, that use an integrated DSP/radio frequency design.

  10. Adaptive fuzzy sliding-mode controller of uncertain nonlinear systems.

    PubMed

    Wu, Tai-Zu; Juang, Yau-Tarng

    2008-07-01

    This paper deals with the design of adaptive fuzzy sliding-mode controllers for the T-S fuzzy model based on the Lyapunov function. It is shown that the Lyapunov function can be used to establish fuzzy sliding surfaces by solving a set of linear matrix inequalities (LMIs). The design of the fuzzy sliding surfaces and the adaptive fuzzy sliding-mode controllers is proposed. The adaptive mechanism is also used to deal with unknown parameter perturbations and external disturbances. Two examples illustrate the feasibility of the proposed methods.

  11. Real-time parallel implementation of Pulse-Doppler radar signal processing chain on a massively parallel machine based on multi-core DSP and Serial RapidIO interconnect

    NASA Astrophysics Data System (ADS)

    Klilou, Abdessamad; Belkouch, Said; Elleaume, Philippe; Le Gall, Philippe; Bourzeix, François; Hassani, Moha M'Rabet

    2014-12-01

    Pulse-Doppler radars require high-computing power. A massively parallel machine has been developed in this paper to implement a Pulse-Doppler radar signal processing chain in real-time fashion. The proposed machine consists of two C6678 digital signal processors (DSPs), each with eight DSP cores, interconnected with Serial RapidIO (SRIO) bus. In this study, each individual core is considered as the basic processing element; hence, the proposed parallel machine contains 16 processing elements. A straightforward model has been adopted to distribute the Pulse-Doppler radar signal processing chain. This model provides low latency, but communication inefficiency limits system performance. This paper proposes several optimizations that greatly reduce the inter-processor communication in a straightforward model and improves the parallel efficiency of the system. A use case of the Pulse-Doppler radar signal processing chain has been used to illustrate and validate the concept of the proposed mapping model. Experimental results show that the parallel efficiency of the proposed parallel machine is about 90%.

  12. A Parallel Sliding Region Algorithm to Make Agent-Based Modeling Possible for a Large-Scale Simulation: Modeling Hepatitis C Epidemics in Canada.

    PubMed

    Wong, William W L; Feng, Zeny Z; Thein, Hla-Hla

    2016-11-01

    Agent-based models (ABMs) are computer simulation models that define interactions among agents and simulate emergent behaviors that arise from the ensemble of local decisions. ABMs have been increasingly used to examine trends in infectious disease epidemiology. However, the main limitation of ABMs is the high computational cost for a large-scale simulation. To improve the computational efficiency for large-scale ABM simulations, we built a parallelizable sliding region algorithm (SRA) for ABM and compared it to a nonparallelizable ABM. We developed a complex agent network and performed two simulations to model hepatitis C epidemics based on the real demographic data from Saskatchewan, Canada. The first simulation used the SRA that processed on each postal code subregion subsequently. The second simulation processed the entire population simultaneously. It was concluded that the parallelizable SRA showed computational time saving with comparable results in a province-wide simulation. Using the same method, SRA can be generalized for performing a country-wide simulation. Thus, this parallel algorithm enables the possibility of using ABM for large-scale simulation with limited computational resources.

  13. DSP algorithms in FPGA: proposition of a new architecture

    NASA Astrophysics Data System (ADS)

    Kolasinski, Piotr; Zabolotny, Wojciech

    2008-01-01

    This paper presents a new reconfigurable architecture created in FPGA which is optimized for DSP algorithms like digital filters or digital transforms. The architecture tries to combine advantages of typical architectures like DSP processors and datapath architecture, while avoiding their drawbacks. The architecture is built from blocks called Operational Units (OU). Each Operational Unit contains the Control Unit (CU), which controls its operation. The Operational Units may operate in parallel, which shortens the processing time. This structure is also highly flexible, because all OUs may operate independently, executing their own programs. User may customize connections between units and modify architecture by adding new modules.

  14. Real time polarization sensor image processing on an embedded FPGA/multi-core DSP system

    NASA Astrophysics Data System (ADS)

    Bednara, Marcus; Chuchacz-Kowalczyk, Katarzyna

    2015-05-01

    Most embedded image processing SoCs available on the market are highly optimized for typical consumer applications like video encoding/decoding, motion estimation or several image enhancement processes as used in DSLR or digital video cameras. For non-consumer applications, on the other hand, optimized embedded hardware is rarely available, so often PC based image processing systems are used. We show how a real time capable image processing system for a non-consumer application - namely polarization image data processing - can be efficiently implemented on an FPGA and multi-core DSP based embedded hardware platform.

  15. Railgun rail gouging by hypervelocity sliding contact

    SciTech Connect

    Barker, L.M.; Trucano, T.G. ); Susoeff, A.R. )

    1989-01-01

    A description is given of a recently resolved mechanisms of gouging which occurs during hypervelocity sliding contact between two materials. A parameter study based on computer modeling of the gouging mechanism is presented in which gouging velocity thresholds are determined for several combinations of sliding materials. Materials which can gouge each other are found to do so only within a certain range of velocities. Related calculations of gaseous material ahead of railgun projectiles are also presented. Gun bore gouging experience with the Lawrence Livermore National Laboratory railgun project is reviewed.

  16. Railgun rail gouging by hypervelocity sliding contact

    SciTech Connect

    Barker, L.M.; Trucano, T.G.; Susoeff, A.R.

    1988-01-01

    A description is given of a recently resolved mechanism of gouging which occurs during hypervelocity sliding contact between two materials. A parameter study based on computer modelling of the gouging mechanism is presented in which gouging velocity thresholds are determined for several combinations of sliding materials. Materials which can gouge each other are found to do so only within a certain range of velocities. Related calculations of gaseous material ahead of railgun projectiles are also presented. Gun bore gouging experience with the Lawrence Livermore National Laboratory railgun project is reviewed.

  17. Second order sliding mode control for a quadrotor UAV.

    PubMed

    Zheng, En-Hui; Xiong, Jing-Jing; Luo, Ji-Liang

    2014-07-01

    A method based on second order sliding mode control (2-SMC) is proposed to design controllers for a small quadrotor UAV. For the switching sliding manifold design, the selection of the coefficients of the switching sliding manifold is in general a sophisticated issue because the coefficients are nonlinear. In this work, in order to perform the position and attitude tracking control of the quadrotor perfectly, the dynamical model of the quadrotor is divided into two subsystems, i.e., a fully actuated subsystem and an underactuated subsystem. For the former, a sliding manifold is defined by combining the position and velocity tracking errors of one state variable, i.e., the sliding manifold has two coefficients. For the latter, a sliding manifold is constructed via a linear combination of position and velocity tracking errors of two state variables, i.e., the sliding manifold has four coefficients. In order to further obtain the nonlinear coefficients of the sliding manifold, Hurwitz stability analysis is used to the solving process. In addition, the flight controllers are derived by using Lyapunov theory, which guarantees that all system state trajectories reach and stay on the sliding surfaces. Extensive simulation results are given to illustrate the effectiveness of the proposed control method. Copyright © 2014 ISA. Published by Elsevier Ltd. All rights reserved.

  18. Gravity Slides With Magnetic Braking

    NASA Technical Reports Server (NTRS)

    Goodrick, Thomas F.

    1995-01-01

    Slides with magnetic braking enable safe emergency descent from tall buildings, fire-truck ladders, towers, and like. According to concept, slide includes sled that moves along stationary aluminum track tilted against top of building. Sled holds set of permanent magnets at preset small distance from surface of track. Passenger stands on, sits on, or strapped to platform on sled. Release device at top of slide holds sled in place until passenger prepared for descent.

  19. Type-1 and Type-2 Fuzzy Logic and Sliding-Mode Based Speed Control of Direct Torque and Flux Control Induction Motor Drives - A Comparative Study

    NASA Astrophysics Data System (ADS)

    Ramesh, Tejavathu; Panda, A. K.; Kumar, S. Shiva

    2013-08-01

    In this research study, the performance of direct torque and flux control induction motor drive (IMD) is presented using five different speed control techniques. The performance of IMD mainly depends on the design of speed controller. The PI speed controller requires precise mathematical model, continuous and appropriate gain values. Therefore, adaptive control based speed controller is desirable to achieve high-performance drive. The sliding-mode speed controller (SMSC) is developed to achieve continuous control of motor speed and torque. Furthermore, the type-1 fuzzy logic speed controller (T1FLSC), type-1 fuzzy SMSC and a new type-2 fuzzy logic speed controller are designed to obtain high performance, dynamic tracking behaviour, speed accuracy and also robustness to parameter variations. The performance of each control technique has been tested for its robustness to parameter uncertainties and load disturbances. The detailed comparison of different control schemes are carried out in a MATALB/Simulink environment at different speed operating conditions, such as, forward and reversal motoring under no-load, load and sudden change in speed.

  20. Fast image-formation algorithm for ultrahigh-resolution airborne squint spotlight synthetic aperture radar based on adaptive sliding receive-window technique

    NASA Astrophysics Data System (ADS)

    Yang, Wei; Zeng, Hong-cheng; Chen, Jie; Wang, Peng-bo

    2014-01-01

    Adaptive sliding receive-window (ASRW) technique was usually introduced in airborne squint synthetic aperture radar (SAR) systems. Airborne squint spotlight SAR varies its receive-window starting time pulse-by-pulse as a function of range-walk, namely, the linear term of range cell migration (RCM). As a result, a huge data volume of the highly squint spotlight SAR echo signal can be significantly reduced. Because the ASRW technique changes the echo-receive starting time and Doppler history, the conventional image algorithm cannot be employed to directly focus airborne squint spotlight ASRW-SAR data. Therefore, a fast image-formation algorithm, based on the principle of the wave number domain algorithm (WDA) and azimuth deramping processing, was proposed for accurately and efficiently focusing the squint spotlight ASRW-SAR data. Azimuth deramping preprocessing was implemented for eliminating azimuth spectrum aliasing. Moreover, bulk compression and modified Stolt mapping were utilized for high-precision focusing. Additionally, geometric correction was employed for compensating the image distortion resulting from the ASRW technique. The proposed algorithm was verified by evaluating the image performance of point targets in different squint angles. In addition, a detailed analysis of computation loads in the appendix indicates that the processing efficiency can be greatly improved, e.g., the processing efficiency could be improved by 17 times in the 70-deg squint angle by applying the proposed image algorithm to the squint spotlight ASRW-SAR data.

  1. Decentralized adaptive robust control based on sliding mode and nonlinear compensator for the control of ankle movement using functional electrical stimulation of agonist-antagonist muscles

    NASA Astrophysics Data System (ADS)

    Kobravi, Hamid-Reza; Erfanian, Abbas

    2009-08-01

    A decentralized control methodology is designed for the control of ankle dorsiflexion and plantarflexion in paraplegic subjects with electrical stimulation of tibialis anterior and calf muscles. Each muscle joint is considered as a subsystem and individual controllers are designed for each subsystem. Each controller operates solely on its associated subsystem, with no exchange of information between the subsystems. The interactions between the subsystems are taken as external disturbances for each isolated subsystem. In order to achieve robustness with respect to external disturbances, unmodeled dynamics, model uncertainty and time-varying properties of muscle-joint dynamics, a robust control framework is proposed which is based on the synergistic combination of an adaptive nonlinear compensator with a sliding mode control and is referred to as an adaptive robust control. Extensive simulations and experiments on healthy and paraplegic subjects were performed to demonstrate the robustness against the time-varying properties of muscle-joint dynamics, day-to-day variations, subject-to-subject variations, fast convergence, stability and tracking accuracy of the proposed method. The results indicate that the decentralized robust control provides excellent tracking control for different reference trajectories and can generate control signals to compensate the muscle fatigue and reject the external disturbance. Moreover, the controller is able to automatically regulate the interaction between agonist and antagonist muscles under different conditions of operating without any preprogrammed antagonist activities.

  2. Friction and wear of oxide-ceramic sliding against IN-718 nickel base alloy at 25 to 800 C in atmospheric air

    NASA Technical Reports Server (NTRS)

    Sliney, Harold E.; Deadmore, Daniel L.

    1989-01-01

    The friction and wear of oxide-ceramics sliding against the nickel base alloy IN-718 at 25 to 800 C were measured. The oxide materials tested were mullite (3Al2O3.2SiO2); lithium aluminum silicate (LiAlSi(x)O(y)); polycrystalline monolithic alpha alumina (alpha-Al2O3); single crystal alpha-Al2O3 (sapphire); zirconia (ZrO2); and silicon carbide (SiC) whisker-reinforced Al2O3 composites. At 25 C the mullite and zirconia had the lowest friction and the polycrystalline monolithic alumina had the lowest wear. At 800 C the Al2O3-8 vol/percent SiC whisker composite had the lowest friction and the Al2O3-25 vol/percent SiC composite had the lowest wear. The friction of the Al2O3-SiC whisker composites increased with increased whisker content while the wear decreased. In general, the wear-resistance of the ceramics improve with their hardness.

  3. Predicting Debris-Slide Locations in Northwestern California

    Treesearch

    Mark E. Reid; Stephen D. Ellen; Dianne L. Brien; Juan de la Fuente; James N. Falls; Billie G. Hicks; Eric C. Johnson

    2007-01-01

    We tested four topographic models for predicting locations of debris-slide sources: 1) slope; 2) proximity to stream; 3) SHALSTAB with "standard" parameters; and 4) debris-slide-prone landforms, which delineates areas similar to "inner gorge" and "headwall swale" using experience-based rules. These approaches were compared in three diverse...

  4. A Computer System for Making Quick and Economical Color Slides.

    ERIC Educational Resources Information Center

    Pryor, Harold George

    1986-01-01

    A computer-based method for producing 35mm color slides has been used in Ohio State University's College of Dentistry. The method can produce both text and slides in less than two hours, providing substantial flexibility in planning and revising visual presentations. (Author/MLW)

  5. Section 608 Rule Presentation Slides

    EPA Pesticide Factsheets

    This document presents slides informing the public about updates to the Section 608 concerning appliance disposal, refrigerant reclamation, technician certification, refrigerant sales restriction, recordkeeping, and repairing refrigerant leaks.

  6. Numerical Modelling of Tsunami Generated by Deformable Submarine Slides: Parameterisation of Slide Dynamics for Coupling to Tsunami Propagation Model

    NASA Astrophysics Data System (ADS)

    Smith, R. C.; Collins, G. S.; Hill, J.; Piggott, M. D.; Mouradian, S. L.

    2015-12-01

    Numerical modelling informs risk assessment of tsunami generated by submarine slides; however, for large-scale slides modelling can be complex and computationally challenging. Many previous numerical studies have approximated slides as rigid blocks that moved according to prescribed motion. However, wave characteristics are strongly dependent on the motion of the slide and previous work has recommended that more accurate representation of slide dynamics is needed. We have used the finite-element, adaptive-mesh CFD model Fluidity, to perform multi-material simulations of deformable submarine slide-generated waves at real world scales for a 2D scenario in the Gulf of Mexico. Our high-resolution approach represents slide dynamics with good accuracy, compared to other numerical simulations of this scenario, but precludes tracking of wave propagation over large distances. To enable efficient modelling of further propagation of the waves, we investigate an approach to extract information about the slide evolution from our multi-material simulations in order to drive a single-layer wave propagation model, also using Fluidity, which is much less computationally expensive. The extracted submarine slide geometry and position as a function of time are parameterised using simple polynomial functions. The polynomial functions are used to inform a prescribed velocity boundary condition in a single-layer simulation, mimicking the effect the submarine slide motion has on the water column. The approach is verified by successful comparison of wave generation in the single-layer model with that recorded in the multi-material, multi-layer simulations. We then extend this approach to 3D for further validation of this methodology (using the Gulf of Mexico scenario proposed by Horrillo et al., 2013) and to consider the effect of lateral spreading. This methodology is then used to simulate a series of hypothetical submarine slide events in the Arctic Ocean (based on evidence of historic

  7. The Dentin Sialoprotein (DSP) Domain Regulates Dental Mesenchymal Cell Differentiation through a Novel Surface Receptor

    PubMed Central

    Wan, Chunyan; Yuan, Guohua; Luo, Daoshu; Zhang, Lu; Lin, Heng; Liu, Huan; Chen, Lei; Yang, Guobin; Chen, Shuo; Chen, Zhi

    2016-01-01

    Dentin sialophosphoprotein (DSPP) is a dentin extracellular matrix protein that is processed into dentin sialoprotein (DSP), dentin glycoprotein (DGP) and dentin phosphoprotein (DPP). DSP is mainly expressed in odontoblasts. We hypothesized that DSP interacts with cell surface receptors and subsequently activates intracellular signaling. Using DSP as bait for screening a protein library, we demonstrate that DSP acts as a ligand and binds to integrin β6. The 36 amino acid residues of DSP are sufficient to bind to integrin β6. This peptide promoted cell attachment, migration, differentiation and mineralization of dental mesenchymal cells. In addition, DSP aa183-219 stimulated phosphorylation of ERK1/2 and P38 kinases. This activation was inhibited by an anti-integrin β6 antibody and siRNA. Furthermore, we demonstrate that this DSP fragment induces SMAD1/5/8 phosphorylation and nuclear translocation via ERK1/2 and P38 signaling. SMAD1/5/8 binds to SMAD binding elements (SBEs) in the DSPP gene promoter. SBE mutations result in a decrease in DSPP transcriptional activity. Endogenous DSPP expression was up-regulated by DSP aa183-219 in dental mesenchymal cells. The data in the current study demonstrate for the first time that this DSP domain acts as a ligand in a RGD-independent manner and is involved in intracellular signaling via interacting with integrin β6. The DSP domain regulates DSPP expression and odontoblast homeostasis via a positive feedback loop. PMID:27430624

  8. The Dentin Sialoprotein (DSP) Domain Regulates Dental Mesenchymal Cell Differentiation through a Novel Surface Receptor.

    PubMed

    Wan, Chunyan; Yuan, Guohua; Luo, Daoshu; Zhang, Lu; Lin, Heng; Liu, Huan; Chen, Lei; Yang, Guobin; Chen, Shuo; Chen, Zhi

    2016-07-19

    Dentin sialophosphoprotein (DSPP) is a dentin extracellular matrix protein that is processed into dentin sialoprotein (DSP), dentin glycoprotein (DGP) and dentin phosphoprotein (DPP). DSP is mainly expressed in odontoblasts. We hypothesized that DSP interacts with cell surface receptors and subsequently activates intracellular signaling. Using DSP as bait for screening a protein library, we demonstrate that DSP acts as a ligand and binds to integrin β6. The 36 amino acid residues of DSP are sufficient to bind to integrin β6. This peptide promoted cell attachment, migration, differentiation and mineralization of dental mesenchymal cells. In addition, DSP (aa183-219) stimulated phosphorylation of ERK1/2 and P38 kinases. This activation was inhibited by an anti-integrin β6 antibody and siRNA. Furthermore, we demonstrate that this DSP fragment induces SMAD1/5/8 phosphorylation and nuclear translocation via ERK1/2 and P38 signaling. SMAD1/5/8 binds to SMAD binding elements (SBEs) in the DSPP gene promoter. SBE mutations result in a decrease in DSPP transcriptional activity. Endogenous DSPP expression was up-regulated by DSP (aa183-219) in dental mesenchymal cells. The data in the current study demonstrate for the first time that this DSP domain acts as a ligand in a RGD-independent manner and is involved in intracellular signaling via interacting with integrin β6. The DSP domain regulates DSPP expression and odontoblast homeostasis via a positive feedback loop.

  9. Using DSP technology to simplify deep space ranging

    NASA Technical Reports Server (NTRS)

    Bryant, S.

    2000-01-01

    Commercially available Digital Signal Processing (DSP) technology has enabled a new spacecraft ranging design. The new design reduces overall size, parts count, and complexity. The design implementation will also meet the Jet Propulsion Laboratory (JPL) requirements for both near-Earth and deep space ranging.

  10. Investigating the role of sliding friction in rolling motion: a teaching sequence based on experiments and simulations

    NASA Astrophysics Data System (ADS)

    De Ambrosis, Anna; Malgieri, Massimiliano; Mascheretti, Paolo; Onorato, Pasquale

    2015-05-01

    We designed a teaching-learning sequence on rolling motion, rooted in previous research about student conceptions, and proposing an educational reconstruction strongly centred on the role of friction in different cases of rolling. A series of experiments based on video analysis is used to highlight selected key concepts and to motivate students in their exploration of the topic; and interactive simulations, which can be modified on the fly by students to model different physical situations, are used to stimulate autonomous investigation in enquiry activities. The activity sequence was designed for students on introductory physics courses and was tested with a group of student teachers. Comparisons between pre- and post-tests, and between our results and those reported in the literature, indicate that students’ understanding of rolling motion improved markedly and some typical difficulties were overcome.

  11. Simulation of sliding of liquid droplets

    NASA Astrophysics Data System (ADS)

    Alen, Saif Khan; Farhat, Nazia; Rahman, Md. Ashiqur

    2016-07-01

    Numerical simulations of sliding behavior of liquid droplets on flat and periodic microgrooved surfaces with a range of groove geometry are conducted. A numerical model is developed which is capable of predicting the critical sliding angle of the drop by comparing the advancing and the receding angles obtained from numerical and experimental findings. The effect of microgroove topography, droplet size and inclination angle on the droplet sliding characteristics is analysed. Using an open-source platform (Surface Evolver), a 3D drop-shape model is developed to numerically determine the drop stability and contact angle hysteresis on tilted surfaces. In this numerical model, the three phase contact line of the drop is obtained by numerically calculating the vertex force and local contact angle at each vertex of the base contour. Several numerical models are developed based on various assumptions of base contour shape (circular or elliptical) and implementation of gravitational force to the droplet. Droplet shapes and critical sliding angles, obtained from these numerical models, are compared with those of experimental results and are found to be in very good agreement.

  12. Mutants of Myxococcus xanthus dsp defective in fibril binding.

    PubMed Central

    Chang, B Y; Dworkin, M

    1996-01-01

    The dsp mutant of Myxococcus xanthus lacks extracellular fibrils and as a result is unable to undergo cohesion, group motility, or development (J. W. Arnold and L. J. Shimkets, J. Bacteriol. 170:5765-5770, 1983; J. W. Arnold and L. J. Shimkets, J. Bacteriol. 170:5771-5777, 1983; R. M. Behmlander and M. Dworkin, J. Bacteriol. 173:7810-7821, 1991; L. J. Shimkets, J. Bacteriol. 166:837-841, 1986; L. J. Shimkets, J. Bacteriol. 166:842-848, 1986). However, cohesion and development can be phenotypically restored by the addition of isolated fibrils (R. M. Behmlander, Ph.D. thesis, University of Minnesota, Minneapolis, 1994; B.-Y. Chang and M. Dworkin, J. Bacteriol. 176:7190-7196, 1994). As part of our attempts to examine the interaction of fibrils and cells of M. xanthus, we have isolated a series of secondary mutants of M. xanthus dsp in which cohesion, unlike that of the parent strain, could not be rescued by the addition of isolated fibrils. Cells of M. xanthus dsp were mutagenized either by ethyl methanesulfonate or by Tn5 insertions. Mutagenized cultures were enriched by selection of those cells that could not be rescued, i.e., that failed to cohere in the presence of isolated fibrils. Seven mutants of M. xanthus dsp, designated fbd mutants, were isolated from 6,983 colonies; these represent putative fibril receptor-minus mutants. The fbd mutants, like the parent dsp mutant, still lacked fibrils, but displayed a number of unexpected properties. They regained group motility and the ability to aggregate but not the ability to form mature fruiting bodies. In addition, they partially regained the ability to form myxospores. The fbd mutant was backcrossed into the dsp mutant by Mx4 transduction. Three independently isolated transconjugants showed essentially the same properties as the fbd mutants--loss of fibril rescue of cohesion, partial restoration of myxospore morphogenesis, and restoration of group motility. These results suggest that the physical presence of fibrils

  13. Sliding Over a Phase Transition

    NASA Astrophysics Data System (ADS)

    Tosatti, Erio; Benassi, Andrea; Vanossi, Andrea; Santoro, Giuseppe E.

    2011-03-01

    The frictional response experienced by a stick-slip slider when a phase transition occurs in the underlying solid substrate is a potentially exciting, poorly explored problem. We show, based on 2-dimensional simulations modeling the sliding of a nanotip, that indeed friction may be heavily affected by a continuous structural transition. First, friction turns nonmonotonic as temperature crosses the transition, peaking at the critical temperature Tc where fluctuations are strongest. Second, below Tc friction depends upon order parameter directions, and is much larger for those where the frictional slip can cause a local flip. This may open a route towards control of atomic scale friction by switching the order parameter direction by an external field or strain, with possible application to e.g., displacive ferroelectrics such as BaTi O3 , as well as ferro- and antiferro-distortive materials. Supported by project ESF FANAS/AFRI sponsored by the Italian Research Council (CNR).

  14. Holographic sliding stripes

    NASA Astrophysics Data System (ADS)

    Jokela, Niko; Järvinen, Matti; Lippert, Matthew

    2017-04-01

    Holographic models provide unique laboratories to investigate nonlinear physics of transport in inhomogeneous systems. We provide a detailed account of both dc and ac conductivities in a defect conformal field theory with spontaneous stripe order. The spatial symmetry is broken at large chemical potential, and the resulting ground state is a combination of a spin and charge density wave. An infinitesimal applied electric field across the stripes will cause the stripes to slide over the underlying density of smeared impurities, a phenomenon which can be associated with the Goldstone mode for the spontaneously broken translation symmetry. We show that the presence of a spatially modulated background magnetization current thwarts the expression of some dc conductivities in terms of horizon data.

  15. Sliding valve pump

    SciTech Connect

    Rupert, C.L.

    1980-09-09

    A sliding valve pump for oil wells which includes a working barrel having a plurality of apertures located in spaced relationship in the wall thereof and a pair of travelling valves fitted within the working barrel and carried by a plunger rod, the valves also having a plurality of apertures or ports for periodic registration with the ports in the working barrel wall to facilitate pumping of fluid from an oil reservoir or pool to the surface. The pump is designed to pull the oil-gas mixture from the reservoir pool into the lower section of the working barrel on the downward stroke, and to subsequently pump the collected oil through the barrel and tubing upwardly toward the surface on the upward stroke.

  16. Generation of Custom DSP Transform IP Cores: Case Study Walsh-Hadamard Transform

    DTIC Science & Technology

    2002-09-01

    Ø Solution: - Formula representation of DSP transforms - Automated formula manipulation and mapping ( ) ( )( ) PFIIDIFDFT ⋅⊗⊗⋅⋅⊗= L222428Formula...Register routing q Hard to automate the process Ø Our approach: formula-based matrix factorization How to fold these wires? Folded L28 L2N N ports Q...Synthesis Technology Libary Bit-width (8) HF factor (1,2,3,6) VF factor (1,2,4, ... 32) Xilinx FPGA Place&Route Xilinx FPGA Place&Route Performance

  17. DSP implementation of wavelet transform for real time ECG wave forms detection and heart rate analysis.

    PubMed

    Bahoura, M; Hassani, M; Hubin, M

    1997-01-01

    An algorithm based on wavelet transform (WTs) suitable for real time implementation has been developed in order to detect ECG characteristics. In particular, QRS complexes, P and T waves may be distinguished from noise, baseline drift or artefacts. This algorithm is implemented in a DSP (SPROC-1400) with a 50 MHz frequency clock. The performance of this algorithm is discussed, its accuracy is evaluated and a comparison is made with a similar algorithm implemented in C language. For the standard MIT/BIH arrhythmia database, this algorithm correctly detects 99.7% of the QRS complexes.

  18. Implementation of FFT Algorithm using DSP TMS320F28335 for Shunt Active Power Filter

    NASA Astrophysics Data System (ADS)

    Patel, Pinkal Jashvantbhai; Patel, Rajesh M.; Patel, Vinod

    2016-07-01

    This work presents simulation, analysis and experimental verification of Fast Fourier Transform (FFT) algorithm for shunt active power filter based on three-level inverter. Different types of filters can be used for elimination of harmonics in the power system. In this work, FFT algorithm for reference current generation is discussed. FFT control algorithm is verified using PSIM simulation results with DLL block and C-code. Simulation results are compared with experimental results for FFT algorithm using DSP TMS320F28335 for shunt active power filter application.

  19. Implementation of FFT Algorithm using DSP TMS320F28335 for Shunt Active Power Filter

    NASA Astrophysics Data System (ADS)

    Patel, Pinkal Jashvantbhai; Patel, Rajesh M.; Patel, Vinod

    2017-06-01

    This work presents simulation, analysis and experimental verification of Fast Fourier Transform (FFT) algorithm for shunt active power filter based on three-level inverter. Different types of filters can be used for elimination of harmonics in the power system. In this work, FFT algorithm for reference current generation is discussed. FFT control algorithm is verified using PSIM simulation results with DLL block and C-code. Simulation results are compared with experimental results for FFT algorithm using DSP TMS320F28335 for shunt active power filter application.

  20. Application of High Resolution Multispectral Imagery for Levee Slide Detection and Monitoring

    NASA Technical Reports Server (NTRS)

    Hossain, A. K. M. Azad; Easson, Greg

    2007-01-01

    The objective is to develop methods to detect and monitor levee slides using commercially available high resolution multispectral imagery. High resolution multispectral imagery like IKONOS and QuickBird are suitable for detecting and monitoring levee slides. IKONOS is suitable for visual inspection, image classification and Tasseled Cap transform based slide detection. Tasseled Cap based model was found to be the best method for slide detection. QuickBird was suitable for visual inspection and image classification.

  1. An efficient sliding window strategy for accurate location of eukaryotic protein coding regions.

    PubMed

    Rao, Nini; Lei, Xu; Guo, Jianxiu; Huang, Hao; Ren, Zhenglong

    2009-04-01

    The sliding window is one of important factors that seriously affect the accuracy of coding region prediction and location for the methods based on power spectrum technique. It is very difficult to select the appropriate sliding step and the window length for different organisms. In this study, a novel sliding window strategy is proposed on the basis of power spectrum analysis for the accurate location of eukaryotic protein coding regions. The proposed sliding window strategy is very simple and the sliding step of window is changeable. Our tests show that the average location error for the novel method is 12 bases. Compared with the previous location error of 54 bases using the fixed sliding step, the novel sliding window strategy increased the location accuracy greatly. Further, the consumed CPU time to run the novel strategy is much shorter than the strategy of the fixed length sliding step. So, the computational complexity for the novel method is decreased greatly.

  2. Using Scrap Slides for Art.

    ERIC Educational Resources Information Center

    Hanlon, Heather

    1979-01-01

    Using scrap slides for an art lesson can be an exciting, creative experience for people of all ages, and many techniques are applicable in both primary and secondary grades. Scrap slides are an inexpensive means to unique, original, and stimulating discoveries about film as an art form. (Author)

  3. Nucleosome sliding: facts and fiction.

    PubMed

    Becker, Peter B

    2002-09-16

    Nucleosome sliding is a frequent result of energy-dependent nucleosome remodelling in vitro. This review discusses the possible roles for nucleosome sliding in the assembly and maintenance of dynamic chromatin and for the regulation of diverse functions in eukaryotic nuclei.

  4. Robust spatiotemporal matching of electronic slides to presentation videos.

    PubMed

    Fan, Quanfu; Barnard, Kobus; Amir, Arnon; Efrat, Alon

    2011-08-01

    We describe a robust and efficient method for automatically matching and time-aligning electronic slides to videos of corresponding presentations. Matching electronic slides to videos provides new methods for indexing, searching, and browsing videos in distance-learning applications. However, robust automatic matching is challenging due to varied frame composition, slide distortion, camera movement, low-quality video capture, and arbitrary slides sequence. Our fully automatic approach combines image-based matching of slide to video frames with a temporal model for slide changes and camera events. To address these challenges, we begin by extracting scale-invariant feature-transformation (SIFT) keypoints from both slides and video frames, and matching them subject to a consistent projective transformation (homography) by using random sample consensus (RANSAC). We use the initial set of matches to construct a background model and a binary classifier for separating video frames showing slides from those without. We then introduce a new matching scheme for exploiting less distinctive SIFT keypoints that enables us to tackle more difficult images. Finally, we improve upon the matching based on visual information by using estimated matching probabilities as part of a hidden Markov model (HMM) that integrates temporal information and detected camera operations. Detailed quantitative experiments characterize each part of our approach and demonstrate an average accuracy of over 95% in 13 presentation videos.

  5. In situ hybridization freeze-assisted punches (IFAP): technique for liquid-based tissue extraction from thin slide-mounted sections for DNA methylation analysis.

    PubMed

    Own, Lawrence S; Patel, Paresh D

    2014-01-01

    In situ hybridization-assisted punches (IFAP) are a low-cost method for extracting tissue from frozen slide-mounted sections as thin as 12 μm. The method synergizes well with standard histological workflows and uses in situ hybridization to target corresponding slide-mounted cryosections that contain the region of interest. Liquid beads of M-1 embedding matrix are applied and snap frozen, binding the matrix to the underlying tissue. Bead-tissue complexes are removed and DNA extracted using a high-salt method. IFAP-extracted DNA is suitable for downstream DNA methylation analysis.

  6. Screening and dotting virtual slides: A new challenge for cytotechnologists

    PubMed Central

    Khalbuss, Walid E.; Cuda, Jackie; Cucoranu, Ioan C.

    2013-01-01

    Digital images are increasingly being used in cytopathology. Whole-slide imaging (WSI) is a digital imaging modality that uses computerized technology to scan and convert entire cytology glass slides into digital images that can be viewed on a digital display using the image viewer software. Digital image acquisition of cytology glass slides has improved significantly over the years due to the use of liquid-based preparations and advances in WSI scanning technology such as automatic multipoint pre-scan focus technology or z-stack scanning technology. Screening cytotechnologists are responsible for every cell that is present on an imaged slide. One of the challenges users have to overcome is to establish a technique to review systematically the entire imaged slide and to dot selected abnormal or significant findings. The scope of this article is to review the current user interface technology available for virtual slide navigation when screening digital slides in cytology. WSI scanner vendors provide tools, built into the image viewer software that allow for a more systematic navigation of the virtual slides, such as auto-panning, keyboard-controlled slide navigation and track map. Annotation tools can improve communication between the screener and the final reviewer or can be used for education. The tracking functionality allows recording of the WSI navigation process and provides a mechanism for confirmation of slide coverage by the screening cytotechnologist as well as a useful tool for quality assurance. As the WSI technology matures, additional features and tools to support navigation of a cytology virtual slide are anticipated. PMID:24379891

  7. Screening and dotting virtual slides: A new challenge for cytotechnologists.

    PubMed

    Khalbuss, Walid E; Cuda, Jackie; Cucoranu, Ioan C

    2013-01-01

    Digital images are increasingly being used in cytopathology. Whole-slide imaging (WSI) is a digital imaging modality that uses computerized technology to scan and convert entire cytology glass slides into digital images that can be viewed on a digital display using the image viewer software. Digital image acquisition of cytology glass slides has improved significantly over the years due to the use of liquid-based preparations and advances in WSI scanning technology such as automatic multipoint pre-scan focus technology or z-stack scanning technology. Screening cytotechnologists are responsible for every cell that is present on an imaged slide. One of the challenges users have to overcome is to establish a technique to review systematically the entire imaged slide and to dot selected abnormal or significant findings. The scope of this article is to review the current user interface technology available for virtual slide navigation when screening digital slides in cytology. WSI scanner vendors provide tools, built into the image viewer software that allow for a more systematic navigation of the virtual slides, such as auto-panning, keyboard-controlled slide navigation and track map. Annotation tools can improve communication between the screener and the final reviewer or can be used for education. The tracking functionality allows recording of the WSI navigation process and provides a mechanism for confirmation of slide coverage by the screening cytotechnologist as well as a useful tool for quality assurance. As the WSI technology matures, additional features and tools to support navigation of a cytology virtual slide are anticipated.

  8. Digital slide reproduction using densitometry

    NASA Astrophysics Data System (ADS)

    Fornaro, Peter R.; Gschwind, Rudolf; Rosenthaler, Lukas; Laurenson, Pip

    2002-06-01

    Many contemporary art collections contain important art installations where artists have used 35 mm slides as the primary medium. The number of ours these works are on show makes it necessary to regularly change the slides due to light fading. With funding from the Henry Moore Foundation. The conservation department at Tate initiated a project to examine ways in which digital technology could be used to aid the conservation of these works. The aim of the project was to place the original slides in cold storage and explored the possibility of using digital technology to make duplicate sets for display in the gallery. The reproductions needed to be of very high quality both in terms of resolution and color management. This paper discusses the use of densitometry to calibrate both device dependent and device independent systems for digitally reproducing 35 mm slides using a scanner and a film recorder and the effect of metamery when using slide films which employ different dyes.

  9. An Implementation of real-time phased array radar fundamental functions on DSP-focused, high performance embedded computing platform

    NASA Astrophysics Data System (ADS)

    Yu, Xining; Zhang, Yan; Patel, Ankit; Zahrai, Allen; Weber, Mark

    2016-05-01

    This paper investigates the feasibility of real-time, multiple channel processing of a digital phased array system backend design, with focus on high-performance embedded computing (HPEC) platforms constructed based on general purpose digital signal processor (DSP). Serial RapidIO (SRIO) is used as inter-chip connection backend protocol to support the inter-core communications and parallelisms. Performance benchmark was obtained based on a SRIO system chassis and emulated configuration similar to a field scale demonstrator of Multi-functional Phased Array Radar (MPAR). An interesting aspect of this work is comparison between "raw and low-level" DSP processing and emerging tools that systematically take advantages of the parallelism and multi-core capability, such as OpenCL and OpenMP. Comparisons with other backend HPEC solutions, such as FPGA and GPU, are also provided through analysis and experiments.

  10. Web-Based Slide Presentations.

    ERIC Educational Resources Information Center

    Just, Melissa L.

    At the University of Southern California's Norris Medical Library, seminars on World Wide Web topics are given to faculty, staff, students, and to community health care providers at remote sites. The presentations have been given using presentation software such as Microsoft PowerPoint, while running Netscape in the background, switching between…

  11. Analysis of tensioned membrane structures considering cable sliding.

    PubMed

    Song, Chang-yong

    2003-01-01

    In routine design of tensioned membrane structures, the membrane is generally modeled using space membrane elements and the cables by space cable elements, with no sliding allowed between the membrane and the cables. On the other hand, large deflections are expected and sliding between the membrane and the cables is inevitable. In the present paper, the general finite element code ABAQUS was employed to investigate the influence of cable sliding on membrane surface on the structural behavior. Three analysis models were devised to fulfill this purpose: (1) The membrane element shares nodes with the cable element; (2) The cable can slide on the membrane surface freely (without friction) and (3) The cable can slide on the membrane surface, but with friction between the cable and the membrane. The sliding problem is modeled using a surface-based contact algorithm. The results from three analysis models are compared, showing that cable sliding has only little influence on the structure shape and on the stress distributions in the membrane. The main influence of cable sliding may be its effect on the dynamic behavior of tensioned membrane structures.

  12. Line copy presentation slides with Kodalith.

    PubMed

    Kraushar, M F; Bailey, B A

    1978-08-01

    Line copy presentation slides with white letters on a blue background can be produced with a two-step process. The slides are more permanent than diazo slides, and the process is faster and less expensive.

  13. An Airship Slide Rule

    NASA Technical Reports Server (NTRS)

    Weaver, E R; Pickering, S F

    1924-01-01

    This report prepared for the National Advisory Committee for Aeronautics, describes an airship slide rule developed by the Gas-Chemistry Section of the Bureau of Standards, at the request of the Bureau of Engineering of the Navy Department. It is intended primarily to give rapid solutions of a few problems of frequent occurrence in airship navigation, but it can be used to advantage in solving a great variety of problems, involving volumes, lifting powers, temperatures, pressures, altitudes and the purity of the balloon gas. The rule is graduated to read directly in the units actually used in making observations, constants and conversion factors being taken care of by the length and location of the scales. It is thought that with this rule practically any problem likely to arise in this class of work can be readily solved after the user has become familiar with the operation of the rule; and that the solution will, in most cases, be as accurate as the data warrant.

  14. Real-time multi-DSP control of three-phase current-source unity power factor PWM rectifier

    SciTech Connect

    Xiao Wang; Boon-Teck Ooi . Dept. of Electrical Engineering)

    1993-07-01

    The design of a real-time multi-DSP controller for a high-quality six-valve three-phase current-source unity power factor PWM rectifier is discussed in this paper. With the decoupler preprocessor and the dynamic trilogic PWM trigger scheme, each of the three input currents can be controlled independently. Based on the a-b-c frame system model and the fast parallel computer control, the pole-placement control method is implemented successfully to achieve fast response in the ac currents. The low-frequency resonance in the ac filter L-C networks has been damped effectively. The experimental results are obtained from a 1-kVA bipolar transistor current-source PWM rectifier with a real-time controller using three TMS320C25 DSP's.

  15. A new FPGA architecture suitable for DSP applications

    NASA Astrophysics Data System (ADS)

    Liyun, Wang; Jinmei, Lai; Jiarong, Tong; Pushan, Tang; Xing, Chen; Xueyan, Duan; Liguang, Chen; Jian, Wang; Yuan, Wang

    2011-05-01

    A new FPGA architecture suitable for digital signal processing applications is presented. DSP modules can be inserted into FPGA conveniently with the proposed architecture, which is much faster when used in the field of digital signal processing compared with traditional FPGAs. An advanced 2-level MUX (multiplexer) is also proposed. With the added SLEEP MODE PASS to traditional 2-level MUX, static leakage is reduced. Furthermore, buffers are inserted at early returns of long lines. With this kind of buffer, the delay of the long line is improved by 9.8% while the area increases by 4.37%. The layout of this architecture has been taped out in standard 0.13 μm CMOS technology successfully. The die size is 6.3 × 4.5 mm2 with the QFP208 package. Test results show that performances of presented classical DSP cases are improved by 28.6%-302% compared with traditional FPGAs.

  16. DSP Implementation of the Multiscale Retinex Image Enhancement Algorithm

    NASA Technical Reports Server (NTRS)

    Hines, Glenn D.; Rahman, Zia-ur; Jobson, Daniel J.; Woodell, Glenn A.

    2004-01-01

    The Retinex is a general-purpose image enhancement algorithm that is used to produce good visual representations of scenes. It performs a non-linear spatial/ spectral transform that synthesizes strong local contrast enhancement and color constancy. A real-time, video frame rate implementation of the Retinex is required to meet the needs of various potential users. Retinex processing contains a relatively large number of complex computations, thus to achieve real-time performance using current technologies requires specialized hardware and software. In this paper we discuss the design and development of a digital signal processor (DSP) implementation of the Retinex. The target processor is a Texas Instruments TMS320C6711 floating point DSP. NTSC video is captured using a dedicated frame grabber card, Retinex processed, and displayed on a standard monitor. We discuss the optimizations used to achieve real-time performance of the Retinex and also describe our future plans on using alternative architectures.

  17. DSP Implementation of the Multiscale Retinex Image Enhancement Algorithm

    NASA Technical Reports Server (NTRS)

    Hines, Glenn D.; Rahman, Zia-ur; Jobson, Daniel J.; Woodell, Glenn A.

    2004-01-01

    The Retinex is a general-purpose image enhancement algorithm that is used to produce good visual representations of scenes. It performs a non-linear spatial/ spectral transform that synthesizes strong local contrast enhancement and color constancy. A real-time, video frame rate implementation of the Retinex is required to meet the needs of various potential users. Retinex processing contains a relatively large number of complex computations, thus to achieve real-time performance using current technologies requires specialized hardware and software. In this paper we discuss the design and development of a digital signal processor (DSP) implementation of the Retinex. The target processor is a Texas Instruments TMS320C6711 floating point DSP. NTSC video is captured using a dedicated frame grabber card, Retinex processed, and displayed on a standard monitor. We discuss the optimizations used to achieve real-time performance of the Retinex and also describe our future plans on using alternative architectures.

  18. DSP Implementation of the Retinex Image Enhancement Algorithm

    NASA Technical Reports Server (NTRS)

    Hines, Glenn; Rahman, Zia-Ur; Jobson, Daniel; Woodell, Glenn

    2004-01-01

    The Retinex is a general-purpose image enhancement algorithm that is used to produce good visual representations of scenes. It performs a non-linear spatial/spectral transform that synthesizes strong local contrast enhancement and color constancy. A real-time, video frame rate implementation of the Retinex is required to meet the needs of various potential users. Retinex processing contains a relatively large number of complex computations, thus to achieve real-time performance using current technologies requires specialized hardware and software. In this paper we discuss the design and development of a digital signal processor (DSP) implementation of the Retinex. The target processor is a Texas Instruments TMS320C6711 floating point DSP. NTSC video is captured using a dedicated frame-grabber card, Retinex processed, and displayed on a standard monitor. We discuss the optimizations used to achieve real-time performance of the Retinex and also describe our future plans on using alternative architectures.

  19. 25. VIEW SHOWING SLIDE GATE OUTLET TRASH RACK STRUCTURE AT ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    25. VIEW SHOWING SLIDE GATE OUTLET TRASH RACK STRUCTURE AT BASE OF ARCH 8. NOTE TWO SECTIONS OF NEEDLE VALVE TRASH RACKS IN PLACE BETWEEN ARCHES 8 AND 9. December 20, 1938 - Bartlett Dam, Verde River, Phoenix, Maricopa County, AZ

  20. Coating for hot sliding seals

    NASA Technical Reports Server (NTRS)

    Stock, J.

    1979-01-01

    Heat resistant paint is effective surface coating for sliding seals that must operate at elevated temperatures. Economical paint is easy to apply, offers minimal friction, and improves reliability of seals.

  1. DSP Algorithms for Fission Fragment and Prompt Fission Neutron Spectroscopy

    SciTech Connect

    Zeynalova, O.; Zeynalov, Sh.; Hambsch, F.-J.; Oberstedt, S.; Fabry, I.

    2009-10-29

    Digital signal processing (DSP) algorithms are in high demand for modern nuclear fission investigation due to importance of increase the accuracy of fissile nuclear data for new generation of nuclear power stations. DSP algorithms for fission fragment (FF) and prompt fission neutron (PFN) spectroscopy are described in the present work. The twin Frisch-grid ionization chamber (GTIC) is used to measure the kinetic energy-, mass- and angular distributions of the FF in the {sup 252}Cf(SF) reaction. Along with the neutron time-of-flight (TOF) measurement the correlation between neutron emission and FF mass and energy is investigated. The TOF is measured between common cathode of the GTIC and the neutron detector (ND) pulses. Waveform digitizers (WFD) having 12 bit amplitude resolution and 100 MHz sampling frequency are used for the detector pulse sampling. DSP algorithms are developed as recursive procedures to perform the signal processing, similar to those available in various nuclear electronics modules, such as constant fraction discriminator (CFD), pulse shape discriminator (PSD), peak-sensitive analogue-to-digital converter (pADC) and pulse shaping amplifier (PSA). To measure the angle between FF and the cathode plane normal to the GTIC a new algorithm is developed having advantage over the traditional analogue pulse processing schemes. Algorithms are tested by comparing the numerical simulation of the data analysis of the {sup 252}Cf(SF) reaction with data available from literature.

  2. Observer-based higher order sliding mode control of power factor in three-phase AC/DC converter for hybrid electric vehicle applications

    NASA Astrophysics Data System (ADS)

    Liu, Jianxing; Laghrouche, Salah; Wack, Maxime

    2014-06-01

    In this paper, a full-bridge boost power converter topology is studied for power factor control, using output higher order sliding mode control. The AC/DC converters are used for charging the battery and super-capacitor in hybrid electric vehicles from the utility. The proposed control forces the input currents to track the desired values, which can control the output voltage while keeping the power factor close to one. Super-twisting sliding mode observer is employed to estimate the input currents and load resistance only from the measurement of output voltage. Lyapunov analysis shows the asymptotic convergence of the closed-loop system to zero. Multi-rate simulation illustrates the effectiveness and robustness of the proposed controller in the presence of measurement noise.

  3. Adaptive super-twisting sliding mode control for a three-phase single-stage grid-connected differential boost inverter based photovoltaic system.

    PubMed

    Pati, Akshaya K; Sahoo, N C

    2017-07-01

    This paper presents an adaptive super-twisting sliding mode control (STC) along with double-loop control for voltage tracking performance of three-phase differential boost inverter and DC-link capacitor voltage regulation in grid-connected PV system. The effectiveness of the proposed control strategies are demonstrated under realistic scenarios such as variations in solar insolation, load power demand, grid voltage, and transition from grid-connected to standalone mode etc. Additional supplementary power quality control functions such as harmonic compensation, and reactive power management are also investigated with the proposed control strategy. The results are compared with conventional proportional-integral controller, and PWM sliding mode controller. The system performance is evaluated in simulation and in real-time. Copyright © 2017 ISA. Published by Elsevier Ltd. All rights reserved.

  4. Single molecule study of a processivity clamp sliding on DNA

    SciTech Connect

    Laurence, T A; Kwon, Y; Johnson, A; Hollars, C; O?Donnell, M; Camarero, J A; Barsky, D

    2007-07-05

    Using solution based single molecule spectroscopy, we study the motion of the polIII {beta}-subunit DNA sliding clamp ('{beta}-clamp') on DNA. Present in all cellular (and some viral) forms of life, DNA sliding clamps attach to polymerases and allow rapid, processive replication of DNA. In the absence of other proteins, the DNA sliding clamps are thought to 'freely slide' along the DNA; however, the abundance of positively charged residues along the inner surface may create favorable electrostatic contact with the highly negatively charged DNA. We have performed single-molecule measurements on a fluorescently labeled {beta}-clamp loaded onto freely diffusing plasmids annealed with fluorescently labeled primers of up to 90 bases. We find that the diffusion constant for 1D diffusion of the {beta}-clamp on DNA satisfies D {le} 10{sup -14} cm{sup 2}/s, much slower than the frictionless limit of D = 10{sup -10} cm{sup 2}/s. We find that the {beta} clamp remains at the 3-foot end in the presence of E. coli single-stranded binding protein (SSB), which would allow for a sliding clamp to wait for binding of the DNA polymerase. Replacement of SSB with Human RP-A eliminates this interaction; free movement of sliding clamp and poor binding of clamp loader to the junction allows sliding clamp to accumulate on DNA. This result implies that the clamp not only acts as a tether, but also a placeholder.

  5. Real-Time Neural Signals Decoding onto Off-the-Shelf DSP Processors for Neuroprosthetic Applications.

    PubMed

    Pani, Danilo; Barabino, Gianluca; Citi, Luca; Meloni, Paolo; Raspopovic, Stanisa; Micera, Silvestro; Raffo, Luigi

    2016-09-01

    The control of upper limb neuroprostheses through the peripheral nervous system (PNS) can allow restoring motor functions in amputees. At present, the important aspect of the real-time implementation of neural decoding algorithms on embedded systems has been often overlooked, notwithstanding the impact that limited hardware resources have on the efficiency/effectiveness of any given algorithm. Present study is addressing the optimization of a template matching based algorithm for PNS signals decoding that is a milestone for its real-time, full implementation onto a floating-point digital signal processor (DSP). The proposed optimized real-time algorithm achieves up to 96% of correct classification on real PNS signals acquired through LIFE electrodes on animals, and can correctly sort spikes of a synthetic cortical dataset with sufficiently uncorrelated spike morphologies (93% average correct classification) comparably to the results obtained with top spike sorter (94% on average on the same dataset). The power consumption enables more than 24 h processing at the maximum load, and latency model has been derived to enable a fair performance assessment. The final embodiment demonstrates the real-time performance onto a low-power off-the-shelf DSP, opening to experiments exploiting the efferent signals to control a motor neuroprosthesis.

  6. Mapping of Myxococcus xanthus Social Motility dsp Mutations to the dif Genes

    PubMed Central

    Lancero, Hope; Brofft, Jennifer E.; Downard, John; Birren, Bruce W.; Nusbaum, Chad; Naylor, Jerome; Shi, Wenyuan; Shimkets, Lawrence J.

    2002-01-01

    Myxococcus xanthus dsp and dif mutants have similar phenotypes in that they are deficient in social motility and fruiting body development. We compared the two loci by genetic mapping, complementation with a cosmid clone, DNA sequencing, and gene disruption and found that 16 of the 18 dsp alleles map to the dif genes. Another dsp allele contains a mutation in the sglK gene. About 36.6 kb around the dsp-dif locus was sequenced and annotated, and 50% of the genes are novel. PMID:11844780

  7. STS-44 DSP / IUS spacecraft tilted to deployment position in OV-104's PLB

    NASA Technical Reports Server (NTRS)

    1991-01-01

    STS-44 Defense Support Program (DSP) / Inertial Upper Stage (IUS) spacecraft, with forward airborne support equipment (ASE) payload retention latch actuator and umbilical boom released (foreground), is raised to a 58 degree deployment position by the ASE aft frame tilt actuator (AFTA) table in the payload bay (PLB) of Atlantis, Orbiter Vehicle (OV) 104. The IUS is supported in the ASE AFTA table and is inscribed with USAF. Above the IUS is the DSP satellite with stowed solar paddles (box-like structure) visible just above the DSP/IUS interface. Lights illuminate the PLB and highlight the IUS and some DSP components against the blackness of space.

  8. High resolution mapping of Dense spike-ar (dsp.ar) to the genetic centromere of barley chromosome 7H.

    PubMed

    Shahinnia, Fahimeh; Druka, Arnis; Franckowiak, Jerome; Morgante, Michele; Waugh, Robbie; Stein, Nils

    2012-02-01

    Spike density in barley is under the control of several major genes, as documented previously by genetic analysis of a number of morphological mutants. One such class of mutants affects the rachis internode length leading to dense or compact spikes and the underlying genes were designated dense spike (dsp). We previously delimited two introgressed genomic segments on chromosome 3H (21 SNP loci, 35.5 cM) and 7H (17 SNP loci, 20.34 cM) in BW265, a BC(7)F(3) nearly isogenic line (NIL) of cv. Bowman as potentially containing the dense spike mutant locus dsp.ar, by genotyping 1,536 single nucleotide polymorphism (SNP) markers in both BW265 and its recurrent parent. Here, the gene was allocated by high-resolution bi-parental mapping to a 0.37 cM interval between markers SC57808 (Hv_SPL14)-CAPSK06413 residing on the short and long arm at the genetic centromere of chromosome 7H, respectively. This region putatively contains more than 800 genes as deduced by comparison with the collinear regions of barley, rice, sorghum and Brachypodium, Classical map-based isolation of the gene dsp.ar thus will be complicated due to the infavorable relationship of genetic to physical distances at the target locus.

  9. SurfaceSlide: a multitouch digital pathology platform.

    PubMed

    Wang, Yinhai; Williamson, Kate E; Kelly, Paul J; James, Jacqueline A; Hamilton, Peter W

    2012-01-01

    Digital pathology provides a digital environment for the management and interpretation of pathological images and associated data. It is becoming increasing popular to use modern computer based tools and applications in pathological education, tissue based research and clinical diagnosis. Uptake of this new technology is stymied by its single user orientation and its prerequisite and cumbersome combination of mouse and keyboard for navigation and annotation. In this study we developed SurfaceSlide, a dedicated viewing platform which enables the navigation and annotation of gigapixel digitised pathological images using fingertip touch. SurfaceSlide was developed using the Microsoft Surface, a 30 inch multitouch tabletop computing platform. SurfaceSlide users can perform direct panning and zooming operations on digitised slide images. These images are downloaded onto the Microsoft Surface platform from a remote server on-demand. Users can also draw annotations and key in texts using an on-screen virtual keyboard. We also developed a smart caching protocol which caches the surrounding regions of a field of view in multi-resolutions thus providing a smooth and vivid user experience and reducing the delay for image downloading from the internet. We compared the usability of SurfaceSlide against Aperio ImageScope and PathXL online viewer. SurfaceSlide is intuitive, fast and easy to use. SurfaceSlide represents the most direct, effective and intimate human-digital slide interaction experience. It is expected that SurfaceSlide will significantly enhance digital pathology tools and applications in education and clinical practice.

  10. SurfaceSlide: A Multitouch Digital Pathology Platform

    PubMed Central

    Wang, Yinhai; Williamson, Kate E.; Kelly, Paul J.; James, Jacqueline A.; Hamilton, Peter W.

    2012-01-01

    Background Digital pathology provides a digital environment for the management and interpretation of pathological images and associated data. It is becoming increasing popular to use modern computer based tools and applications in pathological education, tissue based research and clinical diagnosis. Uptake of this new technology is stymied by its single user orientation and its prerequisite and cumbersome combination of mouse and keyboard for navigation and annotation. Methodology In this study we developed SurfaceSlide, a dedicated viewing platform which enables the navigation and annotation of gigapixel digitised pathological images using fingertip touch. SurfaceSlide was developed using the Microsoft Surface, a 30 inch multitouch tabletop computing platform. SurfaceSlide users can perform direct panning and zooming operations on digitised slide images. These images are downloaded onto the Microsoft Surface platform from a remote server on-demand. Users can also draw annotations and key in texts using an on-screen virtual keyboard. We also developed a smart caching protocol which caches the surrounding regions of a field of view in multi-resolutions thus providing a smooth and vivid user experience and reducing the delay for image downloading from the internet. We compared the usability of SurfaceSlide against Aperio ImageScope and PathXL online viewer. Conclusion SurfaceSlide is intuitive, fast and easy to use. SurfaceSlide represents the most direct, effective and intimate human–digital slide interaction experience. It is expected that SurfaceSlide will significantly enhance digital pathology tools and applications in education and clinical practice. PMID:22292040

  11. Static and dynamic friction in sliding colloidal monolayers

    NASA Astrophysics Data System (ADS)

    Vanossi, Andrea; Manini, Nicola; Tosatti, Erio

    2013-03-01

    In a recent experimental breakthrough, the controlled sliding of 2D colloidal crystals over perfectly regular, laser generated periodic or quasi-periodic `corrugation` potentials has been realized in Bechinger's group. Based on realistic MD simulations which reproduce the main experimentally observed features, we explore the potential impact of colloid monolayer sliding in nanotribology. The free motion of edge-spawned kinks and antikinks in smooth incommensurate sliding is contrasted with the kink-antikink pair nucleation at the large static friction threshold in the commensurate case. The Aubry pinning/depinning transition is also demonstrated, e.g., as a function of the corrugation amplitude. Simulated sliding data allow the extraction of frictional work directly from particles coordinates and velocities as a function of classic friction parameters, primarily speed, and corrugation strength. Analogies with sliding charge-density waves, driven Josephson systems, sliding of rare gas islands, and other novel features suggest further experiments and insights, which promote colloid sliding to a novel friction study instrument. Research partly sponsored by Sinergia Project CRSII2 136287/1.

  12. Baseball and softball sliding injuries: incidence and correlates during one high school league varsity season.

    PubMed

    Stovak, Mark; Parikh, Amit; Harvey, Anne T

    2012-11-01

    To estimate injury rates associated with sliding in high school baseball and softball. Prospective cohort study. Community high school athletic events. Ten high school varsity baseball and softball teams over 1 season. All sliding attempts were recorded during each game and recorded as headfirst, feetfirst, or diveback. Base type, playing surface, and field conditions were also noted. Injury exposure rates by game exposures and sliding/diveback exposures. Data were collected from 153 baseball games and 166 softball games. A greater proportion of slides were associated with injury in softball than in baseball (42.0 and 4.9 per 1000 slides; P < 0.05). Headfirst slides led to more injuries than feetfirst slides in baseball (16.8 vs 0 per 1000 slides; P < 0.05) but not in softball (55 vs 35 per 1000 slides; P = 0.74). More powerful studies are required to determine whether efforts to prevent baseball sliding injuries at the high school level should focus on better education in sliding technique or changes in equipment. Softball players are vulnerable to injury when wearing inadequate protective sliding apparel.

  13. The sliding-helix voltage sensor

    PubMed Central

    Peyser, Alexander; Nonner, Wolfgang

    2012-01-01

    The voltage sensor (VS) domain of voltage-gated ion channels underlies electrical excitability of living cells. We simulate a mesoscale model of the VS domain to determine the functional consequences of some of its physical elements. Our mesoscale model is based on VS charges, linear dielectrics and whole-body motion, applied to an S4 ‘sliding helix’. The electrostatics under voltage-clamped boundary conditions are solved consistently using a boundary element method. Based on electrostatic configurational energy, statistical-mechanical expectations of the experimentally observable relation between displaced charge and membrane voltage are predicted. Consequences of the model are investigated for variations of: S4 configuration (α- and 310-helical), countercharge alignment with S4 charges, protein polarizability, geometry of the gating canal, screening of S4 charges by the baths, and fixed charges located at the bath interfaces. The sliding helix VS domain has an inherent electrostatic stability in the explored parameter space: countercharges present in the region of weak dielectric always retain an equivalent S4 charge in that region but allow sliding movements displacing 3 to 4 e0. That movement is sensitive to small energy variations (< 2kT) along the path dependent on a number of electrostatic parameters tested in our simulations. These simulations show how the slope of the relation between displaced charge and voltage could be tuned in a channel. PMID:22907204

  14. Introducing Slide Sets for the Introductory Astronomy Instructor

    NASA Astrophysics Data System (ADS)

    Meinke, Bonnie K.; Schneider, Nicholas; Brain, David; Schultz, Gregory; Buxner, Sanlyn; Smith, Denise

    2014-11-01

    The NASA Science Mission Directorate (SMD) Science Education and Public Outreach (E/PO) community and Forums work together to bring the cutting-edge discoveries of NASA Astrophysics and Planetary Science missions to the introductory astronomy college classroom. These mission- and grant-based E/PO programs are uniquely poised to foster collaboration between scientists with content expertise and educators with pedagogy expertise. We present two new opportunities for college instructors to bring the latest NASA discoveries in Space Science into their classrooms.In an effort to keep the astronomy classroom apprised of the fast moving field of planetary science, the Division of Planetary Sciences (DPS) has developed “DPS Discoveries”, which are short, topical presentations that can be incorporated into college lectures. The slide sets are targeted at the Introductory Astronomy undergraduate level. Each slide set consists of three slides that cover a description of the discovery, a discussion of the underlying science, and a presentation of the big picture implications of the discovery, with a fourth slide that includes links to associated press releases, images, and primary sources. Topics span all subdisciplines of planetary science, and sets are available in Farsi and Spanish. The NASA SMD Planetary Science Forum has recently partnered with the DPS to continue producing the Discovery slides and connect them to NASA mission science. http://dps.aas.org/education/dpsdisc Similarly, the NASA SMD Astrophysics Forum is coordinating the development of a series of slide sets to help Astronomy 101 instructors incorporate new discoveries in their classrooms. The “Astro 101 slide sets” are presentations 5-7 slides in length on a new development or discovery from a NASA Astrophysics mission relevant to topics in introductory astronomy courses. We intend for these slide sets to help Astronomy 101 instructors include new developments (not yet in their textbooks) into the

  15. Sliding regimes on slow manifolds of systems with fast actuators

    NASA Technical Reports Server (NTRS)

    Sira-Ramirez, Hebertt; Dwyer, Thomas A. W., III

    1987-01-01

    In this article the slow manifold of a system with actuator parasitics is used as a sliding surface on which a Variable Structure Controller recovers the qualitative properties of the reduced order, closed loop system obtained from an ideal actuator-based feedback controller design. Illustrative examples are presented, where (1) the simplicity of reduced order singular perturbation design methods; and (2) the robustness of Variable Structure sliding modes, are advantageously combined.

  16. Adaptive sliding mode control for a class of chaotic systems

    NASA Astrophysics Data System (ADS)

    Farid, R.; Ibrahim, A.; Zalam, B.

    2015-03-01

    Chaos control here means to design a controller that is able to mitigating or eliminating the chaos behavior of nonlinear systems that experiencing such phenomenon. In this paper, an Adaptive Sliding Mode Controller (ASMC) is presented based on Lyapunov stability theory. The well known Chua's circuit is chosen to be our case study in this paper. The study shows the effectiveness of the proposed adaptive sliding mode controller.

  17. Adaptive sliding mode control for a class of chaotic systems

    SciTech Connect

    Farid, R.; Ibrahim, A.; Zalam, B.

    2015-03-30

    Chaos control here means to design a controller that is able to mitigating or eliminating the chaos behavior of nonlinear systems that experiencing such phenomenon. In this paper, an Adaptive Sliding Mode Controller (ASMC) is presented based on Lyapunov stability theory. The well known Chua's circuit is chosen to be our case study in this paper. The study shows the effectiveness of the proposed adaptive sliding mode controller.

  18. Average contact temperature and morphological details of the worn surface of copper based materials under high current density sliding against steel

    NASA Astrophysics Data System (ADS)

    Fadin, V. V.; Aleutdinova, M. I.; Kulikova, O. A.

    2016-11-01

    Dry sliding of copper and sintered composites of composition Cu-bearing steel against AISI steel 1045 under electric current of high contact density have been carried out. It is shown that the surface layer of copper and composites undergoes structural changes and tribolayer containing iron, copper and FeO oxide is formed. It is noted that the thin contact layer contains about 40 at % of oxygen and 40 at % Fe. Appearance of signs of a liquid phase is morphological feature of worn surface. It is established that contact temperature does not exceed 300°C. It allows claiming that melting of metals in tribolayer does not happen.

  19. Single Event Effects (SEE) Testing of Embedded DSP Cores within Microsemi RTAX4000D Field Programmable Gate Array (FPGA) Devices

    NASA Technical Reports Server (NTRS)

    Perez, Christopher E.; Berg, Melanie D.; Friendlich, Mark R.

    2011-01-01

    Motivation for this work is: (1) Accurately characterize digital signal processor (DSP) core single-event effect (SEE) behavior (2) Test DSP cores across a large frequency range and across various input conditions (3) Isolate SEE analysis to DSP cores alone (4) Interpret SEE analysis in terms of single-event upsets (SEUs) and single-event transients (SETs) (5) Provide flight missions with accurate estimate of DSP core error rates and error signatures.

  20. Multiprocessor DSP for real-time data processing on Earth orbiting scatterometers

    NASA Technical Reports Server (NTRS)

    Bachmann, A.; Clark, D.; Lux, J.; Steffke, R.

    2000-01-01

    The implementation of a Multi DSP radar signal processor for a Ku-Band Earth orbiting scatterometer is discussed. A testbed has been assembled using a combination of commercial DSP hardware and spaceflight components to evaluate the proposed multiprocessing approaches. Test results of real-time radar echo processing are presented, as well as proposed designs for future investigation.

  1. Multiprocessor DSP for real-time data processing on Earth orbiting scatterometers

    NASA Technical Reports Server (NTRS)

    Bachmann, A.; Clark, D.; Lux, J.; Steffke, R.

    2000-01-01

    The implementation of a Multi DSP radar signal processor for a Ku-Band Earth orbiting scatterometer is discussed. A testbed has been assembled using a combination of commercial DSP hardware and spaceflight components to evaluate the proposed multiprocessing approaches. Test results of real-time radar echo processing are presented, as well as proposed designs for future investigation.

  2. The National Project and Task Force on Desegregation Strategies--DSP.

    ERIC Educational Resources Information Center

    Education Commission of the States, Denver, CO. National Project and Task Force on Desegregation Studies.

    This booklet lists and discusses different approaches that States can take in order to provide leadership in school desegregation. Emphasis is placed on the services provided by DSP that can help States assume a major responsibility for achieving school desegregation. Two services provided by DSP are described: a clearinghouse of information on…

  3. The National Project and Task Force on Desegregation Strategies--DSP.

    ERIC Educational Resources Information Center

    Education Commission of the States, Denver, CO. National Project and Task Force on Desegregation Studies.

    This booklet lists and discusses different approaches that States can take in order to provide leadership in school desegregation. Emphasis is placed on the services provided by DSP that can help States assume a major responsibility for achieving school desegregation. Two services provided by DSP are described: a clearinghouse of information on…

  4. A novel glass slide filing system for pathology slides.

    PubMed

    Tsai, Steve; Kartono, Francisca; Shitabata, Paul K

    2007-07-01

    The availability of a collection of microscope glass slides for review is essential in the study and practice of pathology. A common problem facing many pathologists is the lack of a well-organized filing system. We present a novel system that would be easily accessible, informative, protective, and portable.

  5. Hierarchical Fuzzy Feature Similarity Combination for Presentation Slide Retrieval

    NASA Astrophysics Data System (ADS)

    Kushki, A.; Ajmal, M.; Plataniotis, K. N.

    2009-12-01

    This paper proposes a novel XML-based system for retrieval of presentation slides to address the growing data mining needs in presentation archives for educational and scholarly settings. In particular, contextual information, such as structural and formatting features, is extracted from the open format XML representation of presentation slides. In response to a textual user query, each extracted feature is used to compute a fuzzy relevance score for each slide in the database. The fuzzy scores from the various features are then combined through a hierarchical scheme to generate a single relevance score per slide. Various fusion operators and their properties are examined with respect to their effect on retrieval performance. Experimental results indicate a significant increase in retrieval performance measured in terms of precision-recall. The improvements are attributed to both the incorporation of the contextual features and the hierarchical feature combination scheme.

  6. The Diplomate in Safety Pharmacology (DSP) certification scheme.

    PubMed

    Authier, Simon; Curtis, Michael J; Soloviev, Maxim; Redfern, Will S; Kallman, Mary Jeanne; Hamlin, Robert L; Leishman, Derek J; Valentin, Jean-Pierre; Koerner, John E; Vargas, Hugo M; Botchway, Alfred; Correll, Krystle; Pugsley, Michael K

    2015-01-01

    As with other professional disciplines there is a growing need from within industry as well as global regulatory authorities for implementation of a certification process in order to assure that appropriate expertise is developed and quality standards are identified for professionals involved in the practice of Safety Pharmacology (SP). In order to meet this need, the Safety Pharmacology Society (SPS) has developed the Diplomate in Safety Pharmacology (DSP) certification process. There are many benefits to certification including authentication of the discipline within the overall pharmaceutical community and with regulatory authorities. It also encourages participation in SPS activities by other professionals (toxicologists, clinicians, academics) who wish to broaden their professional expertise. It provides an opportunity for candidates to strengthen their fundamental scientific knowledge, and stimulates the sharing of data, methods and model development in the form of publications and presentations on relevant topics in SP. Accreditation in SP occurs after candidates successfully complete a written certification examination conducted at the annual SPS meeting. The DSP exam consists primarily of material pertinent to the conduct of SP vital function core battery studies (i.e., cardiovascular, respiratory and central nervous systems), supplemental SP studies (i.e., renal/urinary, gastrointestinal, immunology, and hematology), Regulatory Guidelines (ICH Guidelines) as well as relevant cross-functional knowledge (e.g., physiology, pharmacology, toxicology, biochemistry, pathology, pharmacokinetics, dosing formulation, analytical methods, and statistics). Maintenance of the DSP certification results from the accrual of credits which are gained from a range of educational and scientific contributions. Eligibility requirements include a combination of at least a bachelor degree in science and two years of relevant professional SP experience and one poster presentation

  7. Relative sliding durability of candidate high temperature fiber seal materials

    NASA Technical Reports Server (NTRS)

    Dellacorte, Christopher; Steinetz, Bruce M.

    1992-01-01

    The relative sliding durability behavior of six candidate ceramic fibers for high temperature sliding seal applications is reviewed and compared. Pin on disk tests were used to evaluate potential seal materials by sliding a tow or bundle of the candidate ceramic fiber against a superalloy test disk. Tests were conducted in air under a 2.65 N load, at a sliding velocity of 0.025 m/sec and at temperatures from 25 to 900 C. Friction was measured during the tests and fiber wear, indicated by the extent of fibers broken in the tow or bundle, was measured at the end of each test. For most of the fibers, friction and wear increase with test temperature. The relative fiber durability ranking correlates with tensile strength, indicating that tensile data, which is more readily available than sliding durability data, may be useful in predicting fiber wear behavior under various conditions. A dimensional analysis of the wear data shows that the fiber durability is related to a dimensionless durability ratio which represents the ratio of the fiber strength to the fiber stresses imposed by sliding. The analysis is applicable to fibers with similar diameters and elastic moduli. Based upon the results of the research program, three fiber candidates are recommended for further study as potential seal materials. They are a silicon based complex carbide-oxide fiber, an alumina-boria-silica and an aluminosilicate fiber.

  8. STS-44 DSP / IUS spacecraft tilted to deployment position in OV-104's PLB

    NASA Technical Reports Server (NTRS)

    1991-01-01

    STS-44 Defense Support Program (DSP) / Inertial Upper Stage (IUS) spacecraft, with forward airborne support equipment (ASE) payload retention latch actuator and umbilical boom released, is raised to a 58 degree deployment position by the ASE aft frame tilt actuator (AFTA) table in the payload bay (PLB) of Atlantis, Orbiter Vehicle (OV) 104. The IUS is supported in the ASE AFTA table and is inscribed with USAF. Above the IUS is the DSP satellite with stowed solar paddles (box-like structure) visible just above the DSP/IUS interface. The cylinder at the very top of the DSP satellite is the Infrared (IR) Sensor. Lights illuminate the PLB and highlight the IUS and some DSP components against the blackness of space.

  9. Defense Standardization Program (DSP): Policies and Procedures

    DTIC Science & Technology

    1993-07-01

    insertion of new technology into systems and equipment. i. Sustain anU improve the industrial and technology base. j. Promote competition. k. Improve...allows the Department of Defense to take advan- tage of proven, current technology ; reduces risks associated with development; and supports our...manage" requirements can constrain or reduce technological innova- tions and cost-effective solutions. Standardization documents shall describe what

  10. Creating Slide Show Book Reports.

    ERIC Educational Resources Information Center

    Taylor, Harriet G.; Stuhlmann, Janice M.

    1995-01-01

    Describes the use of "Kid Pix 2" software by fourth grade students to develop slide-show book reports. Highlights include collaboration with education majors from Louisiana State University, changes in attitudes of the education major students and elementary students, and problems with navigation and disk space. (LRW)

  11. Herbaceous Ornamental Plants. Slide Script.

    ERIC Educational Resources Information Center

    Still, Steven

    This document, which is one in a series of curriculum materials that has been developed for use in Ohio agricultural education programs, contains 338 black-and-white photographs of a set of color slides and an accompanying script that, together, are intended as an aid in the study and identification of 150 different commercially important…

  12. Heavy duty complete extension slides

    NASA Astrophysics Data System (ADS)

    Bueno, José Ignacio; Vázquez, Javier

    2001-09-01

    The selection from available commercial market of a set of slides to be used in an habitable pressurised module in space, to draw a 660 mm box out of a rack, up to a completely extracted position in a safely supported configuration, seems in principle not to be a complicated task. That was the first approach taken in the design process of the telescopic guides of the Crew Work Bench (CWB) included in the Fluid Science Laboratory (FSL), part of "ESA Microgravity Facilities for Columbus" within the Columbus Orbital Facility (COF) of the International Space Station (ISS). Nevertheless, common space compatible requirements such as materials, specific environmental loads, available envelope, total weight, etc., can make the selection of telescopic slides from commercial market unfeasible. A specific development to design space compatible telescopic slides for the CWB was undertaken. A set of heavy duty space compatible telescopic slides were designed, manufactured and tested. They should be operative in both, 1-g environment and in orbit, and additionally should withstand an inadvertent astronaut kick or bump of 556 N in any direction.

  13. Linear Motor With Air Slide

    NASA Technical Reports Server (NTRS)

    Johnson, Bruce G.; Gerver, Michael J.; Hawkey, Timothy J.; Fenn, Ralph C.

    1993-01-01

    Improved linear actuator comprises air slide and linear electric motor. Unit exhibits low friction, low backlash, and more nearly even acceleration. Used in machinery in which positions, velocities, and accelerations must be carefully controlled and/or vibrations must be suppressed.

  14. Linear Motor With Air Slide

    NASA Technical Reports Server (NTRS)

    Johnson, Bruce G.; Gerver, Michael J.; Hawkey, Timothy J.; Fenn, Ralph C.

    1993-01-01

    Improved linear actuator comprises air slide and linear electric motor. Unit exhibits low friction, low backlash, and more nearly even acceleration. Used in machinery in which positions, velocities, and accelerations must be carefully controlled and/or vibrations must be suppressed.

  15. Ambulatory REACT: real-time seizure detection with a DSP microprocessor.

    PubMed

    McEvoy, Robert P; Faul, Stephen; Marnane, William P

    2010-01-01

    REACT (Real-Time EEG Analysis for event deteCTion) is a Support Vector Machine based technology which, in recent years, has been successfully applied to the problem of automated seizure detection in both adults and neonates. This paper describes the implementation of REACT on a commercial DSP microprocessor; the Analog Devices Blackfin®. The primary aim of this work is to develop a prototype system for use in ambulatory or in-ward automated EEG analysis. Furthermore, the complexity of the various stages of the REACT algorithm on the Blackfin processor is analysed; in particular the EEG feature extraction stages. This hardware profile is used to select a reduced, platform-aware feature set, in order to evaluate the seizure classification accuracy of a lower-complexity, lower-power REACT system.

  16. Real-time tracking objects in different scenes on DSP and FPGA platform

    NASA Astrophysics Data System (ADS)

    Wang, Qiang; Gao, Zhanhong; Li, Jiangtao

    2009-10-01

    We propose three adaptive tracking approaches in different environments for our particular application. Poid tracking algorithm with iterative image segmentation and robust threshold is adopted for single object tracking in simple background. Multiple targets are detected and tracked using contour tracking algorithm in simple scenarios. Correlation tracking algorithm is more suitable to track an interesting moving object in complex scenes. Moreover, a programmable hardware based on TMS320DM642 DSP and Spatran3E FPGA is put forward. Then the software design methods and implementation on this platform are simultaneously introduced. The different track mode is selected by instructions from control computer. Experiments show that the three tracking algorithms are implemented in real time.

  17. Optimization technology of 9/7 wavelet lifting scheme on DSP*

    NASA Astrophysics Data System (ADS)

    Chen, Zhengzhang; Yang, Xiaoyuan; Yang, Rui

    2007-12-01

    Nowadays wavelet transform has been one of the most effective transform means in the realm of image processing, especially the biorthogonal 9/7 wavelet filters proposed by Daubechies, which have good performance in image compression. This paper deeply studied the implementation and optimization technologies of 9/7 wavelet lifting scheme based on the DSP platform, including carrying out the fixed-point wavelet lifting steps instead of time-consuming floating-point operation, adopting pipelining technique to improve the iteration procedure, reducing the times of multiplication calculation by simplifying the normalization operation of two-dimension wavelet transform, and improving the storage format and sequence of wavelet coefficients to reduce the memory consumption. Experiment results have shown that these implementation and optimization technologies can improve the wavelet lifting algorithm's efficiency more than 30 times, which establish a technique foundation for successfully developing real-time remote sensing image compression system in future.

  18. Applications and challenges of digital pathology and whole slide imaging.

    PubMed

    Higgins, C

    2015-07-01

    Virtual microscopy is a method for digitizing images of tissue on glass slides and using a computer to view, navigate, change magnification, focus and mark areas of interest. Virtual microscope systems (also called digital pathology or whole slide imaging systems) offer several advantages for biological scientists who use slides as part of their general, pharmaceutical, biotechnology or clinical research. The systems usually are based on one of two methodologies: area scanning or line scanning. Virtual microscope systems enable automatic sample detection, virtual-Z acquisition and creation of focal maps. Virtual slides are layered with multiple resolutions at each location, including the highest resolution needed to allow more detailed review of specific regions of interest. Scans may be acquired at 2, 10, 20, 40, 60 and 100 × or a combination of magnifications to highlight important detail. Digital microscopy starts when a slide collection is put into an automated or manual scanning system. The original slides are archived, then a server allows users to review multilayer digital images of the captured slides either by a closed network or by the internet. One challenge for adopting the technology is the lack of a universally accepted file format for virtual slides. Additional challenges include maintaining focus in an uneven sample, detecting specimens accurately, maximizing color fidelity with optimal brightness and contrast, optimizing resolution and keeping the images artifact-free. There are several manufacturers in the field and each has not only its own approach to these issues, but also its own image analysis software, which provides many options for users to enhance the speed, quality and accuracy of their process through virtual microscopy. Virtual microscope systems are widely used and are trusted to provide high quality solutions for teleconsultation, education, quality control, archiving, veterinary medicine, research and other fields.

  19. Multi-Objective Sliding Mode Control on Vehicle Cornering Stability with Variable Gear Ratio Actuator-Based Active Front Steering Systems.

    PubMed

    Ma, Xinbo; Wong, Pak Kin; Zhao, Jing; Xie, Zhengchao

    2016-12-28

    Active front steering (AFS) is an emerging technology to improve the vehicle cornering stability by introducing an additional small steering angle to the driver's input. This paper proposes an AFS system with a variable gear ratio steering (VGRS) actuator which is controlled by using the sliding mode control (SMC) strategy to improve the cornering stability of vehicles. In the design of an AFS system, different sensors are considered to measure the vehicle state, and the mechanism of the AFS system is also modelled in detail. Moreover, in order to improve the cornering stability of vehicles, two dependent objectives, namely sideslip angle and yaw rate, are considered together in the design of SMC strategy. By evaluating the cornering performance, Sine with Dwell and accident avoidance tests are conducted, and the simulation results indicate that the proposed SMC strategy is capable of improving the cornering stability of vehicles in practice.

  20. Multi-Objective Sliding Mode Control on Vehicle Cornering Stability with Variable Gear Ratio Actuator-Based Active Front Steering Systems

    PubMed Central

    Ma, Xinbo; Wong, Pak Kin; Zhao, Jing; Xie, Zhengchao

    2016-01-01

    Active front steering (AFS) is an emerging technology to improve the vehicle cornering stability by introducing an additional small steering angle to the driver’s input. This paper proposes an AFS system with a variable gear ratio steering (VGRS) actuator which is controlled by using the sliding mode control (SMC) strategy to improve the cornering stability of vehicles. In the design of an AFS system, different sensors are considered to measure the vehicle state, and the mechanism of the AFS system is also modelled in detail. Moreover, in order to improve the cornering stability of vehicles, two dependent objectives, namely sideslip angle and yaw rate, are considered together in the design of SMC strategy. By evaluating the cornering performance, Sine with Dwell and accident avoidance tests are conducted, and the simulation results indicate that the proposed SMC strategy is capable of improving the cornering stability of vehicles in practice. PMID:28036037

  1. Design technologies for DSP algorithm implementation on heterogeneous architectures

    NASA Astrophysics Data System (ADS)

    McAllister, John; Yi, Ying; Woods, Roger F.; Walke, Richard L.; Reilly, Darren; Colgan, Kevin

    2003-12-01

    Computationally intensive digital signal processing (DSP) systems sometimes have real time requirements beyond that which programmable processor platform solutions, consisting of RISC and DSP processors, can achieve. The addition of Field Programmable Gate Array (FPGA) components to these platforms provides a configurable hardware resource where increased parallelism levels allow very large computational rates. Techniques to implement circuit architectures from signal flow graph (SFG) algorithm expression can produce highly efficient processor implementations. Applying folding transformations produces implementations where hardware resource usage is reduced at the possible expense of throughput. In this paper a new development methodology is presented which analyses the SFG algorithm to suggest appropriate folding techniques. By characterizing different folding techniques, a template circuit architecture can be created early in the design process which does not alter throughout the remainder of the implementation process. Retiming techniques applied to the algorithm SFG produces the properly timed implementation from the template. By applying this methodology, architectural exploration can be quickly and efficiently performed to generate a set of implementations (an 'implementation space") to best meet the constraints of the system. When applied to a Normalised Lattice Filter design example, the results demonstrate high savings on FPGA resource usage, with little reduction in real time performance, demonstrating the implementation advantage of employing this methodology.

  2. Digital signal processor-based real-time optical Doppler tomography system.

    PubMed

    Yan, Shikui; Piao, Daqing; Chen, Yueli; Zhu, Quing

    2004-01-01

    We present a real-time data-processing and display unit based on a custom-designed digital signal processor (DSP) module for imaging tissue structure and Doppler blood flow. The DSP module is incorporated into a conventional optical coherence tomography system. We also demonstrate the flexibility of embedding advanced Doppler processing algorithms in the DSP module. Two advanced velocity estimation algorithms previously introduced by us are incorporated in this DSP module. Experiments on Intralipid flow demonstrate that a pulsatile flow of several hundred pulses per minute can be faithfully captured in M-scan mode by this DSP system. In vivo imaging of a rat's abdominal blood flow is also presented.

  3. Linear Classification of Dairy Cattle. Slide Script.

    ERIC Educational Resources Information Center

    Sipiorski, James; Spike, Peter

    This slide script, part of a series of slide scripts designed for use in vocational agriculture classes, deals with principles of the linear classification of dairy cattle. Included in the guide are narrations for use with 63 slides, which illustrate the following areas that are considered in the linear classification system: stature, strength,…

  4. Approved Practices in Dairy Reproduction. Slide Script.

    ERIC Educational Resources Information Center

    Roediger, Roger D.; Barr, Harry L.

    This slide script, part of a series of slide scripts designed for use in vocational agriculture classes, deals with approved practices in dairy reproduction. Included in the guide are narrations for use with 200 slides dealing with the following topics: the importance of good reproduction, the male and female roles in reproduction, selection of…

  5. Diseases of Landscape Ornamentals. Slide Script.

    ERIC Educational Resources Information Center

    Powell, Charles C.; Sydnor, T. Davis

    This slide script, part of a series of slide scripts designed for use in vocational agriculture classes, deals with recognizing and controlling diseases found on ornamental landscape plants. Included in the script are narrations for use with a total of 80 slides illustrating various foliar diseases (anthracnose, black spot, hawthorn leaf blight,…

  6. On-Line Retrieval of Clinical Slides.

    ERIC Educational Resources Information Center

    Milgrom, Linda

    The Physical Diagnosis Slide Bank, a collaborative project of the Universities of Washington, California at San Diego, and Arizona, utilizes an online interactive computer program to access a collection of over 2000 teaching clinical slides. Searchable data elements for each slide in the bank include subject descriptors (MeSH); accession number;…

  7. Techniques for Generating Instructional Slides. Final Report.

    ERIC Educational Resources Information Center

    Smith, Edgar A.; And Others

    Common in briefing presentations and in individualized instruction is the use of slides that present materials prepared on a typewriter (questions, instructions, outlines). To increase the efficiency and effectiveness of producing these kind of slides a procedure was developed to facilitate: (1) formatting copy to be used for slides; (2) using…

  8. Selective Lifelong Destruction of Brain Monoaminergic Nerves Through Perinatal DSP-4 Treatment.

    PubMed

    Nowak, Przemysław

    2016-01-01

    N-(2-chloroethyl)-N-ethyl-2-bromobenzylamine (DSP-4) is a highly selective neurotoxin for noradrenergic projections originating from the locus coeruleus (LC). The outcome of the systemic DSP-4 treatment of newborn rats is an alteration in postnatal development of the noradrenergic system, involving the permanent denervation of distal noradrenergic projection areas (neocortex, hippocampus, spinal cord), accompanied by noradrenergic hyperinnervation in regions proximal to the LC cell bodies (cerebellum, pons-medulla). DSP-4 is well tolerated by developing rats and does not increase the mortality rate. Permanent noradrenergic denervation in the cerebral cortex and spinal cord is present at all developmental stages, although this effect is more pronounced in rats treated with DSP-4 at an early age, i.e., up to postnatal day 5 (PND 5). Notably, regional hyperinnervation is a hallmark of neonatal DSP-4 treatment, which is not observed after either prenatal or adult DSP-4 application. In contrast to robust biochemical changes in the brain, DSP-4 treatment of newborn rats has a marginal effect on arousal and cognition functions assessed in adulthood, and these processes are critically influenced by the action of the noradrenergic neurotransmitter, norepinephrine (NE). Conversely, neonatal DSP-4 does not significantly affect 5-hydroxytryptamine (serotonin; 5-HT), dopamine (DA), gamma-aminobutyric acid (GABA), and histamine levels in brain. However, as a consequence of altering the functional efficacy of 5-HT1A, 5-HT1B, DA, and GABA receptors, these neurotransmitter systems are profoundly affected in adulthood. Thus, the noradrenergic lesion obtained with neonatal DSP-4 treatment represents a unique neurobiological technique for exploring the interplay between various neuronal phenotypes and examining the pathomechanism of neurodevelopmental disorders.

  9. Apparatus Would Stain Microscope Slides

    NASA Technical Reports Server (NTRS)

    Breeding, James D.

    1993-01-01

    Proposed apparatus meters specific amounts of fluid out of containers at specific times to stain microscope slides. Intended specifically for semiautomated staining of microbiological and hematological samples in microgravity, leakproof apparatus used in other environments in which technicians have little time to allocate to staining procedures and/or exposure to toxic staining agents or to micro-organisms to be stained hazardous. Apparatus adapted to perform almost any staining procedure and accommodates multiple staining reagents, useful for small or remote clinical laboratories.

  10. Apparatus Would Stain Microscope Slides

    NASA Technical Reports Server (NTRS)

    Breeding, James D.

    1993-01-01

    Proposed apparatus meters specific amounts of fluid out of containers at specific times to stain microscope slides. Intended specifically for semiautomated staining of microbiological and hematological samples in microgravity, leakproof apparatus used in other environments in which technicians have little time to allocate to staining procedures and/or exposure to toxic staining agents or to micro-organisms to be stained hazardous. Apparatus adapted to perform almost any staining procedure and accommodates multiple staining reagents, useful for small or remote clinical laboratories.

  11. High-speed DSP assembly-language code for processing wavefront sensor pixels

    NASA Astrophysics Data System (ADS)

    Schneider, Thomas G.; Shelton, J. Christopher

    2000-06-01

    For CCD wavefront sensor pixel input and processing the Adoptics software in use at the Mt. Wilson 100-inch Hooker telescope utilizes hand-crafted assembly code to maximize use of the Texas Instruments C40 DSP processor's bandwidth. For flexibility the software is built around a conceptual framework that allows compact implementation of wavefront sensor-specific operations as well as adaptability to different CCD architectures. Designed for use in multi-DSP systems, such as those used at Mt. Wilson, the software framework will support many different DSP network topologies and facilitates distributing pixel-processing operations across the network.

  12. Technicians listen to instructions during STS-44 DSP / IUS transfer operation

    NASA Technical Reports Server (NTRS)

    1991-01-01

    Clean-suited technicians, wearing headsets, listen to instructions during Defense Support Program (DSP) satellite / inertial upper stage (IUS) transfer operations in a processing facility at Cape Canaveral Air Force Station. In the background, the DSP satellite atop an inertial upper stage (IUS) is readied for transfer to a payload canister transporter. DSP, a surveillance satellite that can detect missle and space launches as well as nuclear detonations will be boosted into geosynchronous Earth orbit by the IUS during STS-44 mission. View provided by the Kennedy Space Center (KSC) with alternate number KSC-91PC-1748.

  13. Whole-Slide Imaging Digital Pathology as a Platform for Teleconsultation

    PubMed Central

    Wilbur, David C.; Madi, Kalil; Colvin, Robert B.; Duncan, Lyn M.; Faquin, William C.; Ferry, Judith A.; Frosch, Matthew P.; Houser, Stuart L.; Kradin, Richard L.; Lauwers, Gregory Y.; Louis, David N.; Mark, Eugene J.; Mino-Kenudson, Mari; Misdraji, Joseph; Nielsen, Gunnlauger P.; Pitman, Martha B.; Rosenberg, Andrew E.; Smith, R. Neal; Sohani, Aliyah R.; Stone, James R.; Tambouret, Rosemary H.; Wu, Chin-Lee; Young, Robert H.; Zembowicz, Artur; Klietmann, Wolfgang

    2013-01-01

    Context Whole-slide imaging technology offers promise for rapid, Internet-based telepathology consultations between institutions. Before implementation, technical issues, pathologist adaptability, and morphologic pitfalls must be well characterized. Objective To determine whether interpretation of whole-slide images differed from glass-slide interpretation in difficult surgical pathology cases. Design Diagnostically challenging pathology slides from a variety of anatomic sites from an outside laboratory were scanned into whole digital format. Digital and glass slides were independently diagnosed by 2 subspecialty pathologists. Reference, digital, and glass-slide interpretations were compared. Operator comments on technical issues were gathered. Results Fifty-three case pairs were analyzed. There was agreement among digital, glass, and reference diagnoses in 45 cases (85%) and between digital and glass diagnoses in 48 (91%) cases. There were 5 digital cases (9%) discordant with both reference and glass diagnoses. Further review of each of these cases indicated an incorrect digital whole-slide interpretation. Neoplastic cases showed better correlation (93%) than did cases of nonneoplastic disease (88%). Comments on discordant cases related to digital whole technology focused on issues such as fine resolution and navigating ability at high magnification. Conclusions Overall concordance between digital whole-slide and standard glass-slide interpretations was good at 91%. Adjustments in technology, case selection, and technology familiarization should improve performance, making digital whole-slide review feasible for broader telepathology subspecialty consultation applications. PMID:19961250

  14. A technigue exploitation about anti-slide tire polyploid on ice-snow road in winter

    NASA Astrophysics Data System (ADS)

    Xiaojie, Qi; Qiang, Wang; Zhao, Yang; Yunlong, Wang; Guotian, Wang; Degang, Lv

    2017-04-01

    Present studies focus on improving anti-slide property of tyes on ice-snow road by changing material modification of tyre tread and designing groove. However, the basic reason causing starting slide, long braking distance, turning slide slip and so on of tyres used in winter is that tyre tread materials are unitary and homogenous rubber composite which can’t coordinate driving demands of tyres in winter under muti-work condition, and can’t exert their best property when starting, braking and sliding slip. In order to improve comprehensive anti-slide property of tyres, this paper discusses about changing structure, shape and distribution proportion among haploid materials of tyre tread rubber. Polyploid bubber tyre tread technique based on artificial neural network which is in favor of starting, braking and anti-slide slip is optimized and combined. Friction feature and anti-slide mechanism on ice-snow road of polyploid rubber tyre tread are studied using testing technique of low-temperature cabin and computer simulation. A set high anti-slide theories and realizing method systems of polyploid rubber composite formed from basic theory, models and technique method are developped which will be applied into solving anti-slide problem of winter tyres, provide theory instruction for studies on high anti-slide winter tyres, and promote development of application and usage safety of winter tyres.

  15. The Holocene (7.250 14C yrs BP) Storegga Slide, Mid-Norwegian Margin: The Modern Analogue To Paleo High-Latitude Mega Slides

    NASA Astrophysics Data System (ADS)

    Haflidason, H.; Sejrup, H. P.; Nygaard, A.; Gram, I. H.; Bryn, P.

    2004-12-01

    The frequency and timing of mega scale (> 2000 km3) submarine slides identified on the Mid-Norwegian margin clearly indicate that this downslope process seems to be associated with the frequency and timing of shelf-edge glaciations, inititated at c. 1.1 Ma and repeted shelf edge glaciations from 0.5 Ma. Most of these paleo-slides have been released within the present Storegga Slide depression or in the nearby North Sea Fan area. The Storegga Slide is found to have affected an area of ca. 90.000 km2 and a sediment volume of 2500-3200 km3 have been displaced. The large volume of sediments displaced, or mobilised, created a pattern of morphological and topographical features, reflecting the erosional, compressional and depositional slide processes within the Storegga area. From the seafloor texture it has furthermore been shown that a considerable difference in type of source material, length of transportation and degree of disintegration have taken place. The morphological characteristics and the available chronological data show that the Storegga Slide represent one main retrogressive slide event dated to 7.250+/-250 14C yrs BP (8.100+/-250 cal. yrs BP). Based on the detailed morphological mapping a slide generation map for the Storegga Slide event has been generated. The morphological analysis give furthermore an important contribution to the bulk material properties (rheology) characterising the area. Statistical analyses, which will give a good approach to the rheological parameters of the failed sediments and provide a basis for a more complete failure and flow model of the Storegga Slide, show a regression coefficient as high as 0.9 by correlating the run-out distance and the slide area. As an analogue to the recent Storegga Slide event, two paleo mega slides and their associated escarpment, representing the two most extreme slide escarpment settings found within the Storegga Slide, have been studied in some detail. The stratigraphical setting and the slide

  16. Automated single-slide staining device

    NASA Technical Reports Server (NTRS)

    Wilkins, J. R.; Mills, S. M. (Inventor)

    1977-01-01

    A simple apparatus and method is disclosed for making individual single Gram stains on bacteria inoculated slides to assist in classifying bacteria in the laboratory as Gram-positive or Gram-negative. The apparatus involves positioning a single inoculated slide in a stationary position and thereafter automatically and sequentially flooding the slide with increments of a primary stain, a mordant, a decolorizer, a counterstain and a wash solution in a sequential manner without the individual lab technician touching the slide and with minimum danger of contamination thereof from other slides.

  17. Pressure vessel sliding support unit and system using the sliding support unit

    SciTech Connect

    Breach, Michael R.; Keck, David J.; Deaver, Gerald A.

    2013-01-15

    Provided is a sliding support and a system using the sliding support unit. The sliding support unit may include a fulcrum capture configured to attach to a support flange, a fulcrum support configured to attach to the fulcrum capture, and a baseplate block configured to support the fulcrum support. The system using the sliding support unit may include a pressure vessel, a pedestal bracket, and a plurality of sliding support units.

  18. Microstructure and Dry Sliding Wear Behavior of Fe-Based (Cr, Fe)7C3 Composite Coating Fabricated by PTA Welding Process

    NASA Astrophysics Data System (ADS)

    Yuan, Y. L.; Li, Z. G.

    2013-11-01

    Using Cr3C2 and Fe-CrNiBSi powder blends as raw materials, an α-Fe matrix composite coating reinforced by in situ (Cr, Fe)7C3 rods, with a thickness of about 3.6 mm, was fabricated on the surface of AISI A36 low carbon steel by means of plasma-transferred arc welding. The results of microstructural analysis show that in the coating, a large number of carbides, (Cr, Fe)7C3, in rod shape grow, and radiate around some half-dissolved Cr3C2 particles. The results of dry sliding wear tests at loads 100, 200, and 300 N show that the wear resistances of (Cr, Fe)7C3-reinforced coating, respectively, are about 6.9, 14.9, and 17 times higher than that of nonreinforced pure Fe-CrNiBSi alloy coating; the average value and fluctuation range of friction coefficient (FC) of (Cr, Fe)7C3-reinforced coating are less than those of pure Fe-CrNiBSi alloy coating; the main wear mechanisms of pure Fe-CrNiBSi alloy coating are ploughing, deformation, and adhesive wear, whereas those of (Cr, Fe)7C3-reinforced coating are microcutting, abrasive, and oxidation wear; the cracks on surfaces of (Cr, Fe)7C3 rods increased with the increasing loads; and the matrix α-Fe can prevent them from extending further in the composite coating.

  19. Sliding mode controllers for a tempered glass furnace.

    PubMed

    Almutairi, Naif B; Zribi, Mohamed

    2016-01-01

    This paper investigates the design of two sliding mode controllers (SMCs) applied to a tempered glass furnace system. The main objective of the proposed controllers is to regulate the glass plate temperature, the upper-wall temperature and the lower-wall temperature in the furnace to a common desired temperature. The first controller is a conventional sliding mode controller. The key step in the design of this controller is the introduction of a nonlinear transformation that maps the dynamic model of the tempered glass furnace into the generalized controller canonical form; this step facilitates the design of the sliding mode controller. The second controller is based on a state-dependent coefficient (SDC) factorization of the tempered glass furnace dynamic model. Using an SDC factorization, a simplified sliding mode controller is designed. The simulation results indicate that the two proposed control schemes work very well. Moreover, the robustness of the control schemes to changes in the system's parameters as well as to disturbances is investigated. In addition, a comparison of the proposed control schemes with a fuzzy PID controller is performed; the results show that the proposed SDC-based sliding mode controller gave better results.

  20. RecA filament sliding on DNA facilitates homology search

    PubMed Central

    Ragunathan, Kaushik; Liu, Cheng; Ha, Taekjip

    2012-01-01

    During homologous recombination, RecA forms a helical filament on a single stranded (ss) DNA that searches for a homologous double stranded (ds) DNA and catalyzes the exchange of complementary base pairs to form a new heteroduplex. Using single molecule fluorescence imaging tools with high spatiotemporal resolution we characterized the encounter complex between the RecA filament and dsDNA. We present evidence in support of the ‘sliding model’ wherein a RecA filament diffuses along a dsDNA track. We further show that homology can be detected during sliding. Sliding occurs with a diffusion coefficient of approximately 8000 bp2/s allowing the filament to sample several hundred base pairs before dissociation. Modeling suggests that sliding can accelerate homology search by as much as 200 fold. Homology recognition can occur for as few as 6 nt of complementary basepairs with the recognition efficiency increasing for higher complementarity. Our data represents the first example of a DNA bound multi-protein complex which can slide along another DNA to facilitate target search. DOI: http://dx.doi.org/10.7554/eLife.00067.001 PMID:23240082

  1. A semi-probabilistic assessment method for flow slides

    NASA Astrophysics Data System (ADS)

    van den Ham, G.; Mastbergen, D.; de Groot, M.

    2013-12-01

    Flow slides in submerged slopes in non-lithified sandy and silty sediments form a major threat for flood defences along (estuary) coastlines and riverbanks in the Netherlands. Such flow slides may result in failure of levees and structures, eventually leading to flooding of the hinterland. Flow slide is a complex failure mechanism that includes both soil mechanical and hydraulic features. Two important sub-mechanisms are static liquefaction and breach flow. Static liquefaction entails the sudden loss of strength of loosely packed saturated sand or silt resulting in a collapse of the sand body. Breach flow is a more superficial process, involving the upslope retrogression of a local steep part of the slope which generates a turbulent sand-water mixture flow along the sand surface of the under water slope. Both mechanisms need a trigger, e.g. local steepening of the slope by erosion or slip failure. Although a breach flow slide generally takes more time than a liquefaction flow slide, both mechanisms result in a flowing sand-water mixture, that eventually resedimentates under a very gentle slope. Therefore in the analysis of historical flow slides it is often not clear to what extent static soil liquefaction and/or breach flow has played a role. In the current Dutch practice the prediction of levee failure due to flow sliding is based on either simple but conservative empirical rules based on documented historical flow slides in which distinction between mentioned sub-mechanisms is disregarded, or rather complex physical-based models describing mechanisms such as static liquefaction or breach flow. It will be presented how both approaches can be combined into a practical, probabilistic method for assessing dike failure due to flow sliding, accounting for uncertainties of the main influence factors. The method has recently been implemented in the so-called Dike Analysis Module (DAM). DAM is a platform for performing semi-automatic stability analyses on a large number

  2. Optimal sliding guidance algorithm for Mars powered descent phase

    NASA Astrophysics Data System (ADS)

    Wibben, Daniel R.; Furfaro, Roberto

    2016-02-01

    Landing on large planetary bodies (e.g. Mars) with pinpoint accuracy presents a set of new challenges that must be addressed. One such challenge is the development of new guidance algorithms that exhibit a higher degree of robustness and flexibility. In this paper, the Zero-Effort-Miss/Zero-Effort-Velocity (ZEM/ZEV) optimal sliding guidance (OSG) scheme is applied to the Mars powered descent phase. This guidance algorithm has been specifically designed to combine techniques from both optimal and sliding control theories to generate an acceleration command based purely on the current estimated spacecraft state and desired final target state. Consequently, OSG yields closed-loop trajectories that do not need a reference trajectory. The guidance algorithm has its roots in the generalized ZEM/ZEV feedback guidance and its mathematical equations are naturally derived by defining a non-linear sliding surface as a function of the terms Zero-Effort-Miss and Zero-Effort-Velocity. With the addition of the sliding mode and using Lyapunov theory for non-autonomous systems, one can formally prove that the developed OSG law is globally finite-time stable to unknown but bounded perturbations. Here, the focus is on comparing the generalized ZEM/ZEV feedback guidance with the OSG law to explicitly demonstrate the benefits of the sliding mode augmentation. Results show that the sliding guidance provides a more robust solution in off-nominal scenarios while providing similar fuel consumption when compared to the non-sliding guidance command. Further, a Monte Carlo analysis is performed to examine the performance of the OSG law under perturbed conditions.

  3. Robust sliding mode continuous control of an IM drive

    SciTech Connect

    Jezernik, K.; Hren, A.; Drevensek, D.

    1995-12-31

    A control approach for robust trajectory tracking of IM servodrive based on the variable structure systems (VSS) is described. A new discrete-time control algorithm has been developed by combining VSS and Lyapunov design. It possesses all the good properties of the sliding mode and avoids the unnecessary discontinuity of the control input, thus eliminating chattering which has been considering as serious obstacles for applications of VSS. A unified control approach for current, torque and motion control based on the discrete-time sliding mode for application in indirect vector control of an IM drive is developed. The sliding mode approach can be applied to the control of an Im drive due to the replacement of the hysteresis controller with widely used PWM technique. All the theoretical issues are verified by experiment. The experimental system consists of a transputer and a microcontroller, thus allowing parallel processing.

  4. Nanolubrication of sliding components in adaptive optics used in microprojectors

    NASA Astrophysics Data System (ADS)

    Bhushan, Bharat; Lee, Hyungoo; Chaparala, Satish C.; Bhatia, Vikram

    2010-10-01

    Integrated microprojectors are being developed to project a large image on any surface chosen by the users. For a laser-based microprojector, a piezo-electric based adaptive optics unit is adopted in the green laser architecture. The operation of this unit depends on stick-slip motion between the sliding components. Nanolubrication of adaptive optics sliding components is needed to reduce wear and for smooth operation. In this study, a methodology to measure lubricant thickness distribution with a nanoscale resolution is developed. Friction, adhesion, and wear mechanisms of lubricant on the sliding components are studied. Effect of actual composite components, scan direction, scale effect, temperature, and humidity to correlate AFM data with the microscale device performance is studied.

  5. Hybrid neural network fraction integral terminal sliding mode control of an Inchworm robot manipulator

    NASA Astrophysics Data System (ADS)

    Rahmani, Mehran; Ghanbari, Ahmad; Ettefagh, Mir Mohammad

    2016-12-01

    This paper proposes a control scheme based on the fraction integral terminal sliding mode control and adaptive neural network. It deals with the system model uncertainties and the disturbances to improve the control performance of the Inchworm robot manipulator. A fraction integral terminal sliding mode control applies to the Inchworm robot manipulator to obtain the initial stability. Also, an adaptive neural network is designed to approximate the system uncertainties and unknown disturbances to reduce chattering phenomena. The weight matrix of the proposed adaptive neural network can be updated online, according to the current state error information. The stability of the proposed control method is proved by Lyapunov theory. The performance of the adaptive neural network fraction integral terminal sliding mode control is compared with three other conventional controllers such as sliding mode control, integral terminal sliding mode control and fraction integral terminal sliding mode control. Simulation results show the effectiveness of the proposed control method.

  6. Whole slide images and digital media in pathology education, testing, and practice: the Oklahoma experience.

    PubMed

    Fung, Kar-Ming; Hassell, Lewis A; Talbert, Michael L; Wiechmann, Allan F; Chaser, Brad E; Ramey, Joel

    2012-01-01

    Examination of glass slides is of paramount importance in pathology training. Until the introduction of digitized whole slide images that could be accessed through computer networks, the sharing of pathology slides was a major logistic issue in pathology education and practice. With the help of whole slide images, our department has developed several online pathology education websites. Based on a modular architecture, this program provides online access to whole slide images, still images, case studies, quizzes and didactic text at different levels. Together with traditional lectures and hands-on experiences, it forms the back bone of our histology and pathology education system for residents and medical students. The use of digitized whole slide images has a.lso greatly improved the communication between clinicians and pathologist in our institute.

  7. The role of frictional sliding in transverse failure of a titanium aluminide composite

    SciTech Connect

    Marshall, D.B.; Morris, W.L.; Cox, B.N.; Kouris, D.A.

    1996-12-31

    Circumferential frictional sliding between the matrix and fibers in a titanium aluminide matrix composite has been measured during transverse loading using a displacement mapping method based on differential image analysis. Sliding was detected over all of the interface before initiation of the cracks that eventually caused failure. The results are compared with recent analytical solutions for the interfacial stresses that account for near-neighbor fiber interactions. The location at which sliding initiated coincided with the predicted position of maximum shear stress, while the calculated magnitude of the shear stress when sliding began was equal to the previously measured resistance to frictional sliding in the longitudinal direction. The results indicate that circumferential sliding has a strong influence on the local stress concentrations that lead to failure.

  8. Bioaccumulation of trace metals in mussel (Mytilus galloprovincialis) from Mali Ston Bay during DSP toxicity episodes.

    PubMed

    Ujević, Ivana; Vuletić, Nenad; Lušić, Jelena; Nazlić, Nikša; Kušpilić, Grozdan

    2015-07-17

    The Croatian National Monitoring Program revealed the presence of Diarrhetic Shellfish Poisoning (DSP) toxicity in Mediterranean blue mussel (Mytilus galloprovincialis) from breeding farms in southern Adriatic Sea through January to June 2011. The mouse bioassay tests (MBA; at the time the official method for DSP toxins) were accompanied by atypical symptomatology in the animals and this caused doubts about the assay results. Consequently, in parallel studies reported here, the concentration of Cd, Cr, Cu, Ni, Pb and Zn in soft tissue of DSP positive and negative mussels samples was determined. Cd, Cr, Zn and Ni show higher values in approximately 75% of the DSP positive samples, whereas for Pb and Cr the values were 26% and 34%, respectively. This trend was unchanged during the whole observation period.

  9. Effect of DSP-4 induced central noradrenergic depletion on tactile learning in rat.

    PubMed

    Rajabi, Soodeh; Shamsizadeh, Ali; Amini, Hossein; Shirazi, Mohsen; Allahtavakoli, Mohammad; Abbasnejad, Mehdi; Sheibani, Vahid

    2012-01-01

    There is general agreement that norepinephrine could modulate neuronal responses to non-monoaminergic synaptic inputs in the somatosensory cortex. In the present study, we investigated the effect of central norepinephrine depletion on tactile learning in rats. Central norepinephrine depletion was induced using 50 mg/kg of N-(2-chloroethyl)-N-ethyl-2 bromobenzylamine (DSP-4) and verified by high performance liquid chromatography. Memory performance was assessed 1 and 5 weeks after DSP-4 treatment using novel object recognition test. We observed a learning impairment in both DSP-4 groups, as the preference index was not significantly altered when compared to chance level (50%). These findings suggest that depletion of central norepinephrine by DSP-4 leads to impairment of the tactile learning in rats, which can last at least for 35 days.

  10. Quantitive evaluation of dentin sialoprotein (DSP) using microbeads - a potential early marker of root resorption.

    PubMed

    Lombardo, L; Carinci, F; Martini, M; Gemmati, D; Nardone, M; Siciliani, G

    2016-01-01

    This study had the aim of comparing two different methods of analysing dentin sialoprotein (DSP) in the gingival crevicular fluid (GCF): the conventional eLISA approach and a new method involving the use of magnetic micro-beads coated with an antibody specific for DSP prior to eLISA analysis. GCF was taken from six patients following twelve weeks of orthodontic treatment using paper strips inserted into the mesial and distal sulci of the upper incisors, and analysed using both methods. Statistical analysis of the results using the Mann-Whitney non-parametric test showed that the micro-bead approach conferred more reliability and less variability on the conventional eLISA approach. Furthermore, this method, for the first time, enables the quantification of the DSP in the sample in ng/μl. The innovative micro-bead/eLISA approach proposed provides a reliable means of quantifying the DSP in the GCF.

  11. STS-44 DSP satellite and IUS during preflight processing at Cape Canaveral

    NASA Image and Video Library

    1991-10-19

    S91-50773 (19 Oct 1991) --- At a processing facility on Cape Canaveral Air Force Station, the Defense Support Program (DSP) satellite is being transferred into the payload canister transporter for shipment to Launch Pad 39A at KSC. The DSP will be deployed during Space Shuttle Mission STS-44 later this year. It is a surveillance satellite, developed for the Department of Defense, which can detect missile and space launches, as well as nuclear detonations. The Inertial Upper Stage which will boost the DSP satellite to its proper orbital position is the lower portion of the payload. DSP satellites have comprised the spaceborne segment of NORAD's (North American Air Defense Command) Tactical Warning and Attack Assessment System since 1970. STS- 44, carrying a crew of six, will be a ten-day flight.

  12. Designing for Damage: Robust Flight Control Design using Sliding Mode Techniques

    NASA Technical Reports Server (NTRS)

    Vetter, T. K.; Wells, S. R.; Hess, Ronald A.; Bacon, Barton (Technical Monitor); Davidson, John (Technical Monitor)

    2002-01-01

    A brief review of sliding model control is undertaken, with particular emphasis upon the effects of neglected parasitic dynamics. Sliding model control design is interpreted in the frequency domain. The inclusion of asymptotic observers and control 'hedging' is shown to reduce the effects of neglected parasitic dynamics. An investigation into the application of observer-based sliding mode control to the robust longitudinal control of a highly unstable is described. The sliding mode controller is shown to exhibit stability and performance robustness superior to that of a classical loop-shaped design when significant changes in vehicle and actuator dynamics are employed to model airframe damage.

  13. DPP and DSP are Necessary for Maintaining TGF-β1 Activity in Dentin

    PubMed Central

    Yamakoshi, Y.; Kinoshita, S.; Izuhara, L.; Karakida, T.; Fukae, M.; Oida, S.

    2014-01-01

    Porcine dentin sialophosphoprotein (DSPP) is the most abundant non-collagenous protein in dentin. It is processed by proteases into 3 independent proteins: dentin sialoprotein (DSP), dentin glycoprotein (DGP), and dentin phosphoprotein (DPP). We fractionated DPP and DSP along with TGF-β activity by ion exchange (IE) chromatography from developing pig molars and measured their alkaline phosphatase (ALP)-stimulating activity in human periodontal (HPDL) cells with or without TGF-β receptor inhibitor. We then purified TGF-β-unbound or -bound DPP and DSP by reverse-phase high-performance liquid chromatography (RP-HPLC) using the ALP-HPDL system. The TGF-β isoform bound to DPP and DSP was identified as being TGF-β1 by both ELISA and LC-MS/MS analysis. We incubated carrier-free human recombinant TGF-β1 (CF-hTGF-β1) with TGF-β-unbound DPP or DSP and characterized the binding on IE-HPLC using the ALP-HPDL system. When only CF-hTGF-β1 was incubated, approximately 3.6% of the ALP-stimulating activity remained. DPP and DSP rescued the loss of TGF-β1 activity. Approximately 19% and 10% of the ALP stimulating activities were retained by the binding of TGF-β to DPP and DSP, respectively. The type I collagen infrequently bound to CF-hTGF-β1. We conclude that both DPP and DSP help retain TGF-β1 activity in porcine dentin. PMID:24799420

  14. DPP and DSP are Necessary for Maintaining TGF-β1 Activity in Dentin.

    PubMed

    Yamakoshi, Y; Kinoshita, S; Izuhara, L; Karakida, T; Fukae, M; Oida, S

    2014-07-01

    Porcine dentin sialophosphoprotein (DSPP) is the most abundant non-collagenous protein in dentin. It is processed by proteases into 3 independent proteins: dentin sialoprotein (DSP), dentin glycoprotein (DGP), and dentin phosphoprotein (DPP). We fractionated DPP and DSP along with TGF-β activity by ion exchange (IE) chromatography from developing pig molars and measured their alkaline phosphatase (ALP)-stimulating activity in human periodontal (HPDL) cells with or without TGF-β receptor inhibitor. We then purified TGF-β-unbound or -bound DPP and DSP by reverse-phase high-performance liquid chromatography (RP-HPLC) using the ALP-HPDL system. The TGF-β isoform bound to DPP and DSP was identified as being TGF-β1 by both ELISA and LC-MS/MS analysis. We incubated carrier-free human recombinant TGF-β1 (CF-hTGF-β1) with TGF-β-unbound DPP or DSP and characterized the binding on IE-HPLC using the ALP-HPDL system. When only CF-hTGF-β1 was incubated, approximately 3.6% of the ALP-stimulating activity remained. DPP and DSP rescued the loss of TGF-β1 activity. Approximately 19% and 10% of the ALP stimulating activities were retained by the binding of TGF-β to DPP and DSP, respectively. The type I collagen infrequently bound to CF-hTGF-β1. We conclude that both DPP and DSP help retain TGF-β1 activity in porcine dentin.

  15. The dentin sialoprotein (DSP) expression in rat tooth germs following fluoride treatment: an immunohistochemical study.

    PubMed

    Maciejewska, Izabela; Spodnik, Jan Henryk; Wójcik, Sławomir; Domaradzka-Pytel, Beata; Bereznowski, Zdzisław

    2006-03-01

    Fluoride is known to alter expression of dentin matrix proteins and affect their posttranslational modifications. The objective of our study was to examine dentin sialoprotein (DSP) expression in the early and late bell stages of development of the first molar tooth germs in rats treated with fluoride. Pregnant dumps were divided into three groups. They were fed a standard diet and from the fifth day of pregnancy, each group received either tap water (with trace amounts of fluoride), tap water with a low concentration of fluoride, or tap water with a high concentration of fluoride. Changes in DSP expression and distribution were visualized by immunohistochemistry. Immunoreactivity for DSP was detected in the cervical regions of the early bell stage in tooth germs of the 1-day-old animals. The earliest reaction was visible in the control group and the group supplemented with the low fluoride concentration (F(L)) but not in the group supplemented with the high fluoride concentration (F(H)). In early bell stages across all experimental groups, the immunoreactivity to DSP was observed in the cusp tip regions and was localized to preameloblasts, young and mature odontoblasts, dental pulp cells, predentin, and dentin. Generally, more intense positive staining for DSP was detected in animals supplemented with the high fluoride concentration. In the late bell stage found in the 4-day-old control group and the group supplemented with the low fluoride concentration, immunoreactivity for DSP was less intense compared with younger animals. However, immunoreactivity was greater in the group treated with the high dose of fluoride. In this group, the positive immunostaining for DSP, especially in young ameloblasts, was prolonged and relatively strong. Fluoride supplementation causes changes in the developmental pattern of DSP expression and its distribution in rat tooth germs.

  16. A comparison of the dynamic stiffness of the Goldcrown GC-500 grinding machine for three slide designs

    SciTech Connect

    Bennett, J.G.; Goldman, P.; Williams, D.C.; Farrar, C.R.

    1994-01-01

    This report provides a summary of the results obtained from the calculations that compare the dynamic stiffness of three slide design systems for the Goldcrown GC-500 centerless grinder; it also describes the models and procedures used to develop the calculations, the assumptions made, and the details that went into performing this work. The authors developed analytical models of the three Goldcrown slide designs and performed several computational studies to determine the dynamic stiffness of the designs. The three slide systems are hereafter referred to as the plane slide, the INA slide, and the polymer-coated slide. The plane slide is the dovetail slide and way traditionally used in machine tool designs. The INA slide is a design created by Goldcrown using INA Bearing Company recirculating roller bearings, and dampers on a rail guideway. The polymer-coated slide is a design using a low friction polymer coating for a modified plane slide system. A study of the drawings indicated that a comparison could be made, within a reasonable amount of time and effort, that would be indicative of the dynamic stiffness of the three designs if the machine was modeled as being composed of the following seven structural components: (1) the base, (2) the swivel plate, (3) the lower slide, (4) the upper housing, (5) the regulating wheel housing, (6) the ball screw, and (7) the in-feed body.

  17. [Design and implementation of pulse instrument based on DSP].

    PubMed

    Jiao, Qiyu; Pang, Chunying

    2013-03-01

    The Traditional Chinese Medical Pulse Instrument uses the HKG-07B infrared pulse sensor to get pulse signal from the body. It makes full use of the TMS320VC5402 chip to realize time-frequency domain parameters extracting, classification and identification of the pulse signal. The system can store a plenty of pulse signal and realize data communication with the PC via the USB interface. According to acquisition and classification of pulse signal experiments of 200 subjects, the results show that the recognition rate of pulse signal can reach to 87.4%. It is applicable to the clinical diagnosis and detection of the pulse signal and home healthcare.

  18. Neurotoxic effects of DSP-4 on the central noradrenergic system in male zebra finches.

    PubMed

    Waterman, Susanna A; Harding, Cheryl F

    2008-04-09

    When administered systemically, the noradrenergic neurotoxin N-(2-chloroethyl)-N-ethyl-2-bromobenzylamine (DSP-4) appears to target the noradrenergic innervation originating in the locus coeruleus causing long-term decrements in noradrenergic function. In songbirds, DSP-4-treatment decreased female-directed singing by males and copulation solicitation responses of females to male songs. However, DSP-4 treatment in songbirds did not lower measures of NE function in the brain to the same extent as it does in mammals. The current study had two goals: determining if two DSP-4 treatments 10 days apart would cause significant decrements in noradrenergic function in male zebra finches and determining if, as in other species, the noradrenergic innervation of midbrain and cortical areas would be profoundly affected while hypothalamic areas were spared. Dopamine-beta-hydroxylase immunoreactivity (DBH-ir) was quantified in thirteen brain regions (five vocal control nuclei, one auditory nucleus, two hypothalamic nuclei, and five additional areas that demonstrated high DBH labeling in controls). Within 20 days, DSP-4 treatment profoundly reduced the number of DBH-ir cells in both the locus coeruleus and ventral subcoeruleus. Unlike a previous study, DBH labeling delineated four out of five vocal control nuclei and an auditory nucleus. As expected, DSP-4 treatment significantly decreased DBH labeling in all areas examined in the mesencephalon and telencephalon without significantly affecting DBH-ir in hypothalamic areas. This double treatment regime appears to be much more effective in decreasing noradrenergic function in songbirds than the single treatment typically used.

  19. Neonatal DSP-4 treatment modifies GABAergic neurotransmission in the prefrontal cortex of adult rats.

    PubMed

    Bortel, Aleksandra; Nowak, Przemyslaw; Brus, Ryszard

    2008-01-01

    N-(2-chloroethyl)-N-ethyl-2-bromobenzylamine (DSP-4) is a noradrenergic neurotoxin which selectively damages noradrenergic projections originating from the locus coeruleus (LC). DSP-4 treatment of rats on the first and third days after birth produces a long-lasting lesion of noradrenergic neurons in the prefrontal cortex (PFC). In DSP-4-lesioned rats, studied as adults, we observed a decrease in norepinephrine content, with no significant change in the levels of dopamine, 5-hydroxytryptamine, and gamma-aminobutyric acid (GABA). There is now a well established interaction between noradrenergic and GABAergic systems, whereby the noradrenergic system is involved in the regulation of basal GABA release, while GABAergic neurons simultaneously exert tonic inhibitory regulation of LC norepinephrine neurons. We examined GABAergic neurotransmission in the norepinephrine-denervated PFC for a better appreciation of the interaction between these two systems. Treatment with the GABA transaminase inhibitor vigabatrine (VGB) increased the GABA level of PFC (tissue content) in both intact and lesioned groups. Additionally, VGB increased extracellular GABA concentration in the PFC in both control and DSP-4-lesioned animals, but the elevation of GABA was 2-fold higher in DSP-4 lesioned rats. These findings indicate that neonatal DSP-4 treatment increases GABAergic neurotransmission in the PFC of rats in adulthood, perhaps by decreasing reactivity of central GABA(A) receptors.

  20. A sliding mode controller for vehicular traffic flow

    NASA Astrophysics Data System (ADS)

    Li, Yongfu; Kang, Yuhao; Yang, Bin; Peeta, Srinivas; Zhang, Li; Zheng, Taixong; Li, Yinguo

    2016-11-01

    This study proposes a sliding mode controller for vehicular traffic flow based on a car-following model to enhance the smoothness and stability of traffic flow evolution. In particular, the full velocity difference (FVD) model is used to capture the characteristics of vehicular traffic flow. The proposed sliding mode controller is designed in terms of the error between the desired space headway and the actual space headway. The stability of the controller is guaranteed using the Lyapunov technique. Numerical experiments are used to compare the performance of sliding mode control (SMC) with that of feedback control. The results illustrate the effectiveness of the proposed SMC method in terms of the distribution smoothness and stability of the space headway, velocity, and acceleration profiles. They further illustrate that the SMC strategy is superior to that of the feedback control strategy, while enabling computational efficiency that can aid in practical applications.