Analog-to-digital conversion using custom CMOS analog memory for the EOS time projection chamber

International Nuclear Information System (INIS)

Lee, K.L.; Arthur, A.A.; Jones, R.W.; Matis, H.S.; Nakamura, M.; Kleinfelder, S.A.; Ritter, H.G.; Wienman, H.H.

1990-01-01

This paper describes the multiplexing scheme of custom CMOS analog memory integrated circuits, 16 channels x 256 cells, into analog to digital converters (ADC's) to handle 15,360 signal channels of a time projection, chamber detector system. Primary requirements of this system are high density, low power and large dynamic range. The analog memory device multiplexing scheme was designed to digitize the information stored in the memory cells. The digitization time of the ADC's and the settling times for the memory unit were carefully interleaved to optimize the performance and timing during the multiplexing operation. This kept the total number of ADC's, a costly and power dissipative component, to an acceptable minimum

Analog and digital signal analysis from basics to applications

CERN Document Server

Cohen Tenoudji, Frédéric

2016-01-01

This book provides comprehensive, graduate-level treatment of analog and digital signal analysis suitable for course use and self-guided learning. This expert text guides the reader from the basics of signal theory through a range of application tools for use in acoustic analysis, geophysics, and data compression. Each concept is introduced and explained step by step, and the necessary mathematical formulae are integrated in an accessible and intuitive way. The first part of the book explores how analog systems and signals form the basics of signal analysis. This section covers Fourier series and integral transforms of analog signals, Laplace and Hilbert transforms, the main analog filter classes, and signal modulations. Part II covers digital signals, demonstrating their key advantages. It presents z and Fourier transforms, digital filtering, inverse filters, deconvolution, and parametric modeling for deterministic signals. Wavelet decomposition and reconstruction of non-stationary signals are also discussed...

Teleseism-based Relative Time Corrections for Modern Analyses of Digitized Analog Seismograms

Science.gov (United States)

Lee, T. A.; Ishii, M.

2017-12-01

With modern-day instruments and seismic networks timed by GPS systems, synchronization of data streams is all but a forgone conclusion. However, during the analog era, when each station had its own clock, comparing data timing from different stations was a far more daunting prospect. Today, with recently developed methods by which analog data can be digitized, having the ability to accurately reconcile the timings of two separate stations would open decades worth of data to modern analyses. For example, one possible and exciting application would be using noise interferometry with digitized analog data in order to investigate changing structural features (on a volcano for example) over a much longer timescale than was previously possible. With this in mind, we introduce a new approach to sync time between stations based on teleseismic arrivals. P-wave arrivals are identified at stations for pairs of earthquakes from the digital and analog eras that have nearly identical distances, locations, and depths. Assuming accurate timing of the modern data, relative time corrections between a pair of stations can then be inferred for the analog data. This method for time correction depends upon the analog stations having modern equivalents, and both having sufficiently long durations of operation to allow for recording of usable teleseismic events. The Hawaii Volcano Observatory (HVO) network is an especially ideal environment for this, as it not only has a large and well-preserved collection of analog seismograms, but also has a long operating history (1912 - present) with many of the older stations having modern equivalents. As such, the scope of this project is to calculate and apply relative time corrections to analog data from two HVO stations, HILB (1919-present) and UWE (1928-present)(HILB now part of Pacific Tsunami network). Further application of this method could be for investigation of the effects of relative clock-drift, that is, the determining factor for how

A simple method of digitizing analog scintigrams for quantification and digital archiving

International Nuclear Information System (INIS)

Schramm, M.; Kaempfer, B.; Wolf, H.; Clausen, M.; Wendhausen, H.; Henze, E.

1993-01-01

This study was undertaken to evaluate a quick, reliable and cheap method of digitizing analog scintigrams. 40 whole-body bone scintigrams were obtained simultaneously in analog and genuine digital format. The analog scans on X-ray film were then digitized seecondarily by three different methods: 300 dpi flatbed scanning, high-resolution camera scanning and camcorder recording. A simple exposure approach using a light box, a cheap camcorder, a PC and image grabber hard- and software proved to be optimal. Visual interpretation showed no differences in clinical findings when comparing the analog images with their secondarily digitized counterparts. To test the possibility of quantification, 126 equivalent ROIs were drawn both in the genuine digital and the secondarily digitized images. Comparing the ROI count to whole-body count percentage of the corresponding ROIs showed the correlation to be linear. The evaluation of phantom studies showed the linear correlation to be true within a wide activity range. Thus, secondary digitalization of analog scintigrams is an easy, cheap and reliable method of archiving images and allows secondary digital quantification. (orig.) [de

[A simple method of digitizing analog scintigrams for quantification and digital archiving].

Science.gov (United States)

Schramm, M; Kämpfer, B; Wolf, H; Clausen, M; Wendhausen, H; Henze, E

1993-02-01

This study was undertaken to evaluate a quick, reliable and cheap method of digitizing analog scintigrams. 40 whole-body bone scintigrams were obtained simultaneously in analog and genuine digital format. The analog scans on x-ray film were then digitized secondarily by three different methods: 300 dpi flat-bed scanning, high-resolution camera scanning and camcorder recording. A simple exposure approach using a light box, a cheap camcorder, a PC and image grabber hard- and software proved to be optimal. Visual interpretation showed no differences in clinical findings when comparing the analog images with their secondarily digitized counterparts. To test the possibility of quantification, 126 equivalent ROIs were drawn both in the genuine digital and the secondarily digitized images. Comparing the ROI count to whole-body count percentage of the corresponding ROIs showed the correlation to be linear. The evaluation of phantom studies showed the linear correlation to be true within a wide activity range. Thus, secondary digitalization of analog scintigrams is an easy, cheap and reliable method of archiving images and allows secondary digital quantification.

Benefit of Analog, Programmable and Digital Hearing Aids

Directory of Open Access Journals (Sweden)

Jamileh Fatahi

2006-12-01

Full Text Available Background and Aims: As the hearing aid technology progressively promotes toward replacing analog hearing aids with digital and programmable ones, comparison of the patient satisfaction of those kinds of hearing aids by means of a valuable tool seems so necessary. So, the aim of this study was to compare self-reported benefit of analog, digitally controlled programmable and digital hearing aids for reducing disability caused by hearing impairment in mild to severe sensorineural hearing impaired persons. Materials and Methods: This cross-sectional study was performed on 90 persons with mild to severe sensorineural hearing loss dividing into three groups: 43 subjects were fitted with digital, 15 with programmable, 32 with analog hearing aids. After pure tone audiometry, Abbreviated profile of hearing aid benefit (APHAB was completed before and one month after using hearing aids to determine the benefit of them. Results: Global APHAB mean scores for digital, programmable and analog hearing aids were 49.05, 33.19 and 39.53, respectively. Ease of Communication subscale mean scores were 53.46 for digitals, 37.66 for programmables and 39.09 for analogs. Background noise subscale mean scores for digital programmable and analog hearing aids were 46.36, 25.53 and 35.31, respectively. Global and also both subscale mean scores showed significant difference between digital hearing aids and programmable and analog ones. There was no significant difference between reverberation subscale mean scores of three groups. Conclusion: It seems digital hearing aids may be more beneficial to reduce disability caused by hearing loss than analog and programmable hearing aids are.

Combined analog-to-digital converter

International Nuclear Information System (INIS)

Zhukov, A.V.; Rzhendinskaya, S.N.

1983-01-01

A 10-bit analog-to-digital converter (ADC) designed for operating in spectrometers with time-dependent filters is described. The ADC operation is based on combining the parallel reading and sequential counting methods. At maximum conversion time of 12 μs, timing series frequency of 25 MHz and foUr reference levels the differential nonlinearity withoUt statistical smoothing (maximum relative channel width deviation from average value) is not more than 4%

Ultra-Low-Power Analog-to-Digital Converters for Medical Applications

OpenAIRE

Zhang, Dai

2014-01-01

Biomedical systems are commonly attached to or implanted into human bodies, and powered by harvested energy or small batteries. In these systems, analog-to-digital converters (ADCs) are key components as the interface between the analog world and the digital domain. Conversion of the low frequency bioelectric signals does not require high speed, but ultralow- power operation. This combined with the required conversion accuracy makes the design of such ADCs a major challenge. Among prevalent A...

As Film Goes Byte: The Change From Analog to Digital Film Perception

OpenAIRE

Loertscher, Miriam Laura; Weibel, David; Spiegel, Simon; Flueckiger, Barbara; Mennel, Pierre; Mast, Fred; Iseli, Christian

2016-01-01

The digital revolution changed film production in many ways. Until the end of the 20th century, most film professionals and critics preferred celluloid film. However, no previous empirical study compared complete narrative films recorded with analog and digital cinematography. Three short narrative films were produced with an analog and a digital camera attached to a 3D rig in order to control all optical parameters. In postproduction, a third version of a digital film was created to mimic th...

As Film Goes Byte: The Change From Analog to Digital Film Perception.

OpenAIRE

Loertscher M. L. Weibel D. Spiegel S. Flueckiger B. Mennel P. Mast F. W. & Iseli C.

2016-01-01

The digital revolution changed film production in many ways. Until the end of the 20th century most film professionals and critics preferred celluloid film. However no previous empirical study compared complete narrative films recorded with analog and digital cinematography. Three short narrative films were produced with an analog and a digital camera attached to a 3D rig in order to control all optical parameters. In postproduction a third version of a digital film was created to mimic the a...

Digital-Analog Hybrid Scheme and Its Application to Chaotic Random Number Generators

Science.gov (United States)

Yuan, Zeshi; Li, Hongtao; Miao, Yunchi; Hu, Wen; Zhu, Xiaohua

2017-12-01

Practical random number generation (RNG) circuits are typically achieved with analog devices or digital approaches. Digital-based techniques, which use field programmable gate array (FPGA) and graphics processing units (GPU) etc. usually have better performances than analog methods as they are programmable, efficient and robust. However, digital realizations suffer from the effect of finite precision. Accordingly, the generated random numbers (RNs) are actually periodic instead of being real random. To tackle this limitation, in this paper we propose a novel digital-analog hybrid scheme that employs the digital unit as the main body, and minimum analog devices to generate physical RNs. Moreover, the possibility of realizing the proposed scheme with only one memory element is discussed. Without loss of generality, we use the capacitor and the memristor along with FPGA to construct the proposed hybrid system, and a chaotic true random number generator (TRNG) circuit is realized, producing physical RNs at a throughput of Gbit/s scale. These RNs successfully pass all the tests in the NIST SP800-22 package, confirming the significance of the scheme in practical applications. In addition, the use of this new scheme is not restricted to RNGs, and it also provides a strategy to solve the effect of finite precision in other digital systems.

VHDL Implementation of Sigma-Delta Analog To Digital Converter

Science.gov (United States)

Chavan, R. N.; Chougule, D. G.

2010-11-01

Sigma-Delta modulation techniques provide a range of opportunities in a signal processing system for both increasing performance and data path optimization along the silicon area axis in the design space. One of the most challenging tasks in Analog to Digital Converter (ADC) design is to adapt the circuitry to ever new CMOS process technology. For digital circuits the number of gates per square mm app. doubles per chip generation. Integration of analog parts in newer deep submicron technologies is much more tough and additionally complicated because the usable voltage ranges are decreasing with every new integration step. This paper shows an approach which only uses 2 resistors and 1 capacitor which are located outside a pure digital chip. So all integration advantages of pure digital chips are preserved, there is no design effort for a new chip generation and the ADC also can be used for FPGAs. Resolutions of up to 16 bit are achievable. Sample rates in the 1 MHz region are feasible so that the approach is also useful for ADCs for xDSL technologies.

Energy savings assessment for digital-to-analog converter boxes

International Nuclear Information System (INIS)

Cheung, Hoi Ying; Meier, Alan; Brown, Richard

2011-01-01

The Digital Television (DTV) Converter Box Coupon Program was administered by the U.S. government to subsidize purchases of digital-to-analog converter boxes, with up to two $40 coupons for each eligible household. In order to qualify as Coupon Eligible Converter Boxes (CECBs), these devices had to meet a number of minimum performance specifications, including energy efficiency standards. The Energy Star Program also established voluntary energy efficiency specifications that are more stringent than the CECB requirements. In this study, we measured the power and energy consumptions for a sample of 12 CECBs (including 6 Energy Star labeled models) in-use in homes and estimated aggregate energy savings produced by the energy efficiency policies. Based on the 35 million coupons redeemed through the end of the program, our analysis indicates that between 2500 and 3700 GWh per year are saved as a result of the energy efficiency policies implemented on digital-to-analog converter boxes. The energy savings generated are equivalent to the annual electricity use of 280,000 average US homes. - Research highlights: → We examined energy efficiency policies on digital-to-analog converter boxes in US. → The government assistance program resulted in high participation. → 35 million coupons were redeemed for the purchases of energy efficient DTAs. → Between 2500 and 3700 GWh per year are saved as a result of the policies. → Savings are equivalent to the annual electricity use of 280,000 average US homes.

Analog-to-digital clinical data collection on networked workstations with graphic user interface.

Science.gov (United States)

Lunt, D

1991-02-01

An innovative respiratory examination system has been developed that combines physiological response measurement, real-time graphic displays, user-driven operating sequences, and networked file archiving and review into a scientific research and clinical diagnosis tool. This newly constructed computer network is being used to enhance the research center's ability to perform patient pulmonary function examinations. Respiratory data are simultaneously acquired and graphically presented during patient breathing maneuvers and rapidly transformed into graphic and numeric reports, suitable for statistical analysis or database access. The environment consists of the hardware (Macintosh computer, MacADIOS converters, analog amplifiers), the software (HyperCard v2.0, HyperTalk, XCMDs), and the network (AppleTalk, fileservers, printers) as building blocks for data acquisition, analysis, editing, and storage. System operation modules include: Calibration, Examination, Reports, On-line Help Library, Graphic/Data Editing, and Network Storage.

A study of analog-to digital sliding scale. Converter utilization

Energy Technology Data Exchange (ETDEWEB)

Maddaleno, F; Rossi, M

1996-12-31

The well-known Sliding Scale technique provides a statistical linearization of the Analog to Digital Converter, obtaining a high differential linearity. This technique sums at each conversion a known and uncorrelated variable signal (offset) to the analog input signal, and then subs tract numerically the offset from the conversion result. 2 refs.

Global orbit feedback utilizing analog and digital technologies

International Nuclear Information System (INIS)

Singh, O.; Tang, Y.; Ramamoorthy, S.; Krinsky, S.; Yu, L.H.

1997-01-01

At the NSLS, an analog global orbit feedback system is used in regular operations, and a digital global orbit feedback system is available in machine physics studies on the X-Ray Ring. Here, the authors discuss the relative merits of utilizing analog and digital technology in orbit feedback. Results of experiments are reported characterizing the performance of the analog and digital systems when operated individually or together. They give their thoughts on plans for future development of the orbit feedback systems at the NSLS

Total cost of performing analog-to-digital upgrades

International Nuclear Information System (INIS)

Albrigo, T.

1993-01-01

The financial well-being of nuclear power plants in the United States is dependent on reducing costs. Rapid advances in industrial technology have created a conundrum for utility executives and their engineering staffs. Digital technology is being touted as beneficial in many ways; however, a number of significant issues have been raised regarding the adequacy and financial viability of digital systems in nuclear power plants. Actual or perceived problems with digital system design, development, and installation have caused significant financial losses for nuclear utilities. This paper provides a list of problems that must be considered in performing an analog-to-digital conversion or for doing a large digital upgrade. It is desirable that the full financial risks associated with these types of upgrades are considered. Specific problems encountered at Palo Verde nuclear generating station are reviewed to emphasize some of the problem areas

PG&E's Seismic Network Goes Digital With Strong Motion: Successes and Challenges

Science.gov (United States)

Stanton, M. A.; Cullen, J.; McLaren, M. K.

2008-12-01

Pacific Gas and Electric Company (PG&E) is in year 3 of a 5-year project to upgrade the Central Coast Seismic Network (CCSN) from analog to digital. Located along the south-central California coast, the CCSN began operation in 1987, with 20 analog stations; 15 vertical component and 5 dual gain 3-component S-13 sensors. The analog signals travel over FM radio telemetry links and voice channels via PG&E's microwave network to our facility in San Francisco (SF), where the A/D conversion is performed on a computer running Earthworm v7.1, which also transmits the data to the USGS in Menlo Park. At the conversion point the dynamic ranges of the vertical and dual-gain sensors are 40-50dB and 60-70dB, respectively. Dynamic range exceedance (data clipping) generally occurs for a M2.5 or greater event within about 40 km of a station. The motivations to upgrade the seismic network were the need for higher dynamic range and to retire obsolete analog transmission equipment. The upgraded digital stations consist of the existing velocity sensors, a 131A-02/3 accelerometer and a Reftek 130-01 Broadband Seismic Recorder for digital data recording and transmission to SF. Vertical only stations have one component of velocity and 3 components of acceleration. Dual gain sites have 3 components of velocity and 3 of acceleration. To date we have successfully upgraded 6 sites; 3 more will be installed by the end of 2008. Some of the advantages of going digital are 1) data is recorded at each site and in SF, 2) substantially increased dynamic range of the velocity sensors to 120dB, as observed by on scale, close-by recordings from a M3.9 San Simeon aftershock on 04/29/2008, 3) accelerometers for on scale recording of large earthquakes, and 4) ability to contribute our strong motion data to USGS ShakeMaps. A significant challenge has been consistent radio communications. To resolve this issue we are installing point-to-multipoint Motorola Canopy spread spectrum radios at the stations and

Digitizing high frequency signals using serial analog memories

International Nuclear Information System (INIS)

Coonrod, J.W.

1975-10-01

An online computer system has been developed as a replacement for oscilloscopes and cameras on the Tormac project. Up to 32 simultaneous waveforms are recorded at up to 2 MHz in analog shift registers, then digitized sequentially after the event into a small PDP-11 computer. Data and functions of data may be displayed or plotted locally, and then forwarded for storage at a larger, remote computer via a network arrangement. Advantages over scopes have been lower incremental cost (approximately $200/channel), less noise pickup, better resolution (less than 1%), and immediate presentation of data

An introduction to analog and digital communications

CERN Document Server

Haykin, Simon

2012-01-01

The second edition of this accessible book provides readers with an introductory treatment of communication theory as applied to the transmission of information-bearing signals. While it covers analog communications, the emphasis is placed on digital technology. It begins by presenting the functional blocks that constitute the transmitter and receiver of a communication system. Readers will next learn about electrical noise and then progress to multiplexing and multiple access techniques.

Digital redesign of anti-wind-up controller for cascaded analog system.

Science.gov (United States)

Chen, Y S; Tsai, J S H; Shieh, L S; Moussighi, M M

2003-01-01

The cascaded conventional anti-wind-up (CAW) design method for integral controller is discussed. Then, the prediction-based digital redesign methodology is utilized to find the new pulse amplitude modulated (PAM) digital controller for effective digital control of the analog plant with input saturation constraint. The desired digital controller is determined from existing or pre-designed CAW analog controller. The proposed method provides a novel methodology for indirect digital design of a continuous-time unity output-feedback system with a cascaded analog controller as in the case of PID controllers for industrial control processes with the presence of actuator saturations. It enables us to implement an existing or pre-designed cascaded CAW analog controller via a digital controller effectively.

New system for digital to analog transformation and reconstruction of 12-lead ECGs.

Science.gov (United States)

Kothadia, Roshni; Kulecz, Walter B; Kofman, Igor S; Black, Adam J; Grier, James W; Schlegel, Todd T

2013-01-01

We describe initial validation of a new system for digital to analog conversion (DAC) and reconstruction of 12-lead ECGs. The system utilizes an open and optimized software format with a commensurately optimized DAC hardware configuration to accurately reproduce, from digital files, the original analog electrocardiographic signals of previously instrumented patients. By doing so, the system also ultimately allows for transmission of data collected on one manufacturer's 12-lead ECG hardware/software into that of any other. To initially validate the system, we compared original and post-DAC re-digitized 12-lead ECG data files (∼5-minutes long) in two types of validation studies in 10 patients. The first type quantitatively compared the total waveform voltage differences between the original and re-digitized data while the second type qualitatively compared the automated electrocardiographic diagnostic statements generated by the original versus re-digitized data. The grand-averaged difference in root mean squared voltage between the original and re-digitized data was 20.8 µV per channel when re-digitization involved the same manufacturer's analog to digital converter (ADC) as the original digitization, and 28.4 µV per channel when it involved a different manufacturer's ADC. Automated diagnostic statements generated by the original versus reconstructed data did not differ when using the diagnostic algorithm from the same manufacturer on whose device the original data were collected, and differed only slightly for just 1 of 10 patients when using a third-party diagnostic algorithm throughout. Original analog 12-lead ECG signals can be reconstructed from digital data files with accuracy sufficient for clinical use. Such reconstructions can readily enable automated second opinions for difficult-to-interpret 12-lead ECGs, either locally or remotely through the use of dedicated or cloud-based servers.

New system for digital to analog transformation and reconstruction of 12-lead ECGs.

Directory of Open Access Journals (Sweden)

Roshni Kothadia

Full Text Available INTRODUCTION: We describe initial validation of a new system for digital to analog conversion (DAC and reconstruction of 12-lead ECGs. The system utilizes an open and optimized software format with a commensurately optimized DAC hardware configuration to accurately reproduce, from digital files, the original analog electrocardiographic signals of previously instrumented patients. By doing so, the system also ultimately allows for transmission of data collected on one manufacturer's 12-lead ECG hardware/software into that of any other. MATERIALS AND METHODS: To initially validate the system, we compared original and post-DAC re-digitized 12-lead ECG data files (∼5-minutes long in two types of validation studies in 10 patients. The first type quantitatively compared the total waveform voltage differences between the original and re-digitized data while the second type qualitatively compared the automated electrocardiographic diagnostic statements generated by the original versus re-digitized data. RESULTS: The grand-averaged difference in root mean squared voltage between the original and re-digitized data was 20.8 µV per channel when re-digitization involved the same manufacturer's analog to digital converter (ADC as the original digitization, and 28.4 µV per channel when it involved a different manufacturer's ADC. Automated diagnostic statements generated by the original versus reconstructed data did not differ when using the diagnostic algorithm from the same manufacturer on whose device the original data were collected, and differed only slightly for just 1 of 10 patients when using a third-party diagnostic algorithm throughout. CONCLUSION: Original analog 12-lead ECG signals can be reconstructed from digital data files with accuracy sufficient for clinical use. Such reconstructions can readily enable automated second opinions for difficult-to-interpret 12-lead ECGs, either locally or remotely through the use of dedicated or cloud

A Novel Analog-to-digital conversion Technique using nonlinear duty-cycle modulation

OpenAIRE

Jean Mbihi; François Ndjali Beng; Martin Kom; Léandre Nneme Nneme

2012-01-01

A new type of analog-to-digital conversion technique is presented in this paper. The interfacing hardware is a very simple nonlinear circuit with 1-bit modulated output. As a implication, behind the hardware simplicity retained is hidden a dreadful nonlinear duty-cycle modulation ratio. However, the overall nonlinear behavior embeds a sufficiently wide linear range, for a rigorous digital reconstitution of the analog input signal using a standard linear filter. Simulation and experimental r...

Design of analog-type high-speed SerDes using digital components for optical chip-to-chip link

Science.gov (United States)

Sangirov, Jamshid; Nguyen, Nga T. H.; Ngo, Trong-Hieu; Im, Dong-min; Ukaegbu, Augustine I.; Lee, Tae-Woo; Cho, Mu Hee; Park, Hyo-Hoon

2010-02-01

An analog-type high-speed serializer/deserializer (SerDes) has been designed for optical links especially between CPU and memory. The circuit uses a system clock and its phases to multiplex data to the serial link which avoids the need for a PLL-based high frequency clock generation used in serializing parallel data as in conventional SerDes design. The multiplexed link combined with the de-serializing clock is used as a reference signal for de-serialization. The SerDes is being designed in a 0.13 μm Si-CMOS technology. The fabricated serializer has a core chip size of 360 x750 μm2. Power dissipation for the SerDes is 71.4 mW operating up to 6.5 Gbps.

Analog-to-digital conversion of spectrometric data in information-control systems of activation analysis

Energy Technology Data Exchange (ETDEWEB)

Mamonov, E I

1972-01-01

Analog-digital conversion (ADC) techniques in nuclear radiation spectrometer channels is a most important link of information control systems in activation analysis. For the development of the ADC of spectrometer channels logico-structural methods of increasing the capacity, procedures for boosting frequency modes and improving the accuracy are promising. Procedures are suggested for increasing the ADC capacity. Insufficient stability and noticeable non-linearity of the spectrometer channel can be corrected at the information processing stage if their regularities are known. Capacity limitations make the development of ADC featuring high stability, capacity and linearity quite urgent.

A 16 b 2 GHz digital-to-analog converter in 0.18 μm CMOS with digital calibration technology

International Nuclear Information System (INIS)

Yang Weidong; Pu Jie; Zhang Ruitao; Chen Chao; Zang Jiandong; Li Tiehu; Luo Pu

2015-01-01

This paper presents a 16-bit 2 GSPS digital-to-analog converter (DAC) in 0.18 μm CMOS technology. This DAC is implemented using time division multiplex access system architecture in the digital domain. The input data is received with a two-channel LVDS interface. The DLL technology is introduced to meet the timing requirements between phases of the LVDS data and the data sampling clock. A FIFO is designed to absorb the phase difference between the data clock and DAC system clock. A delay controller is integrated to adjust the phase relationship between the high speed digital clock and analog clock, obtaining a sampling rate of 2 GSPS. The current source mismatch at higher bits is calibrated in the digital domain. Test results show that the DAC achieves 74.02 dBC SFDR at analog output of 36 MHz, and DNL less than ±2.1 LSB and INL less than ±4.3 LSB after the chip is calibrated. (paper)

From Analog to Digital Medias in Early Childhood Education

DEFF Research Database (Denmark)

Brandt, Erika Zimmer

2015-01-01

Research aims: The aim of the study is to explore how the encounters between children and their educators alter when the media changes from analog to digital. Relationship to previous research works Tablets and other handheld, electronic devices has become part of everyday life in kindergartens....... Research shows that there are both potential pedagogical difficulties and possibilities connected to using digital media (ex. Thestrup 2015, Tække and Paulsen 2014) Theoretical and conceptual framework: The study is a single case study of an educational experiment (Flyvbjerg 2006). It is carried out...

High quality digital holographic reconstruction on analog film

Science.gov (United States)

Nelsen, B.; Hartmann, P.

2017-05-01

High quality real-time digital holographic reconstruction, i.e. at 30 Hz frame rates, has been at the forefront of research and has been hailed as the holy grail of display systems. While these efforts have produced a fascinating array of computer algorithms and technology, many applications of reconstructing high quality digital holograms do not require such high frame rates. In fact, applications such as 3D holographic lithography even require a stationary mask. Typical devices used for digital hologram reconstruction are based on spatial-light-modulator technology and this technology is great for reconstructing arbitrary holograms on the fly; however, it lacks the high spatial resolution achievable by its analog counterpart, holographic film. Analog holographic film is therefore the method of choice for reconstructing highquality static holograms. The challenge lies in taking a static, high-quality digitally calculated hologram and effectively writing it to holographic film. We have developed a theoretical system based on a tunable phase plate, an intensity adjustable high-coherence laser and a slip-stick based piezo rotation stage to effectively produce a digitally calculated hologram on analog film. The configuration reproduces the individual components, both the amplitude and phase, of the hologram in the Fourier domain. These Fourier components are then individually written on the holographic film after interfering with a reference beam. The system is analogous to writing angularly multiplexed plane waves with individual component phase control.

Diamond-Shaped Semiconductor Ring Lasers for Analog to Digital Photonic Converters

National Research Council Canada - National Science Library

Green, Malcolm

2004-01-01

Photonic/ optoelectronic analog to digital converters (ADCs) have advantages in areas such as precise sampling times, narrow sampling apertures, and the ability to sample without contaminating the incident signal...

Emergent Explorations: Analog and Digital Scripting

OpenAIRE

Worden, Alexander

2011-01-01

This book documents an exploration of emergent and linear modes of defining space, form, and structure. The thesis highlights a dialog between analog and digital modeling techniques, in concept and project development. It identifies that analog modeling techniques, coupled with judgment, can be used to develop complex forms. The thesis project employs critical judgment and the textile techniques of crochet as a vehicle generate form. Crochet lends itself to this investigation because it ...

Digital Ecology: Coexistence and Domination among Interacting Networks

Science.gov (United States)

Kleineberg, Kaj-Kolja; Boguñá, Marián

2015-05-01

The overwhelming success of Web 2.0, within which online social networks are key actors, has induced a paradigm shift in the nature of human interactions. The user-driven character of Web 2.0 services has allowed researchers to quantify large-scale social patterns for the first time. However, the mechanisms that determine the fate of networks at the system level are still poorly understood. For instance, the simultaneous existence of multiple digital services naturally raises questions concerning which conditions these services can coexist under. Analogously to the case of population dynamics, the digital world forms a complex ecosystem of interacting networks. The fitness of each network depends on its capacity to attract and maintain users’ attention, which constitutes a limited resource. In this paper, we introduce an ecological theory of the digital world which exhibits stable coexistence of several networks as well as the dominance of an individual one, in contrast to the competitive exclusion principle. Interestingly, our theory also predicts that the most probable outcome is the coexistence of a moderate number of services, in agreement with empirical observations.

All-optical analog-to-digital converter based on Kerr effect in photonic crystal

Science.gov (United States)

Jafari, Dariush; Nurmohammadi, Tofiq; Asadi, Mohammad Javad; Abbasian, Karim

2018-05-01

In this paper, a novel all-optical analog-to-digital converter (AOADC) is proposed and simulated for proof of principle. This AOADC is designed to operate in the range of telecom wavelength (1550 nm). A cavity made of nonlinear Kerr material in photonic crystal (PhC), is designed to achieve an optical analog-to-digital conversion with 1 Tera sample per second (TS/s) and the total footprint of 42 μm2 . The simulation is done using finite-difference time domain (FDTD) method.

Digital circuit for the introduction and later removal of dither from an analog signal

Science.gov (United States)

Borgen, Gary S.

1994-05-01

An electronics circuit is presented for accurately digitizing an analog audio or like data signal into a digital equivalent signal by introducing dither into the analog signal and then subsequently removing the dither from the digitized signal prior to its conversion to an analog signal which is a substantial replica of the incoming analog audio or like data signal. The electronics circuit of the present invention is characterized by a first pseudo-random number generator which generates digital random noise signals or dither for addition to the digital equivalent signal and a second pseudo-random number generator which generates subtractive digital random noise signals for the subsequent removal of dither from the digital equivalent signal prior its conversion to the analog replica signal.

Analog to digital conversion for nuclear spectrometry

International Nuclear Information System (INIS)

Carvalho, P.V.R. de.

1982-04-01

A study of the analog to digital conversion techniques for nuclear spectrometry is presented and the main design philosophies of nuclear ADC's are compared. Among them, the most suitable for the current Brazilian conditions, concerning the specifications and components avaiability is the one that employs a statistical correction of successive approximation converters. This technique is described in full detail. A prototype has been developed an tested for the practical demonstration of the theoretical conclusions. These tests was carried on nuclear spectrometry data aquisition system whose implementation is also described. (Author) [pt

Risk assessment of safety data link and network communication in digital safety feature control system of nuclear power plant

International Nuclear Information System (INIS)

Lee, Sang Hun; Son, Kwang Seop; Jung, Wondea; Kang, Hyun Gook

2017-01-01

Highlights: • Safety data communication risk assessment framework and quantitative scheme were proposed. • Fault-tree model of ESFAS unavailability due to safety data communication failure was developed. • Safety data link and network risk were assessed based on various ESF-CCS design specifications. • The effect of fault-tolerant algorithm reliability of safety data network on ESFAS unavailability was assessed. - Abstract: As one of the safety-critical systems in nuclear power plants (NPPs), the Engineered Safety Feature-Component Control System (ESF-CCS) employs safety data link and network communication for the transmission of safety component actuation signals from the group controllers to loop controllers to effectively accommodate various safety-critical field controllers. Since data communication failure risk in the ESF-CCS has yet to be fully quantified, the ESF-CCS employing data communication systems have not been applied in NPPs. This study therefore developed a fault tree model to assess the data link and data network failure-induced unavailability of a system function used to generate an automated control signal for accident mitigation equipment. The current aim is to provide risk information regarding data communication failure in a digital safety feature control system in consideration of interconnection between controllers and the fault-tolerant algorithm implemented in the target system. Based on the developed fault tree model, case studies were performed to quantitatively assess the unavailability of ESF-CCS signal generation due to data link and network failure and its risk effect on safety signal generation failure. This study is expected to provide insight into the risk assessment of safety-critical data communication in a digitalized NPP instrumentation and control system.

Analysis and characterization of cyclic-scale compensated analog-to-digital converters

International Nuclear Information System (INIS)

Gatti, E.; Manfredi, P.F.; Marino, D.

1979-01-01

The authors discuss characteristics and limitations of cyclic-scale compensated analog-to-digital converters. After summarizing the behaviour of the method implemented in an ideal way, they show how the inaccuracies in the auxillary analog levels affect the real design. Having stated under what approximations and with what cares a cyclic-scale compensated converter approaches the ideal case of channels having equal profiles, the consequences of this property, are studied. (Auth.)

Broadband analog to digital conversion with spatial-spectral holography

International Nuclear Information System (INIS)

Babbitt, W. Randall; Neifeld, Mark A.; Merkel, Kristian D.

2007-01-01

A new approach to broadband photonic-assisted analog-to-digital converter (ADC) technology is proposed and analyzed. The core of the device is a spatial spectral holographic (SSH) material, which can directly record the signals of interest in the frequency domain. An SSH-ADC acts as a frequency-domain stretch processor, which leverages the high performance of conventional ADCs by converting high bandwidth input signals to low bandwidth output signals without loss of information. Analysis of a 10 GHz bandwidth SSH-ADC predicts that 10-bit performance can be achieved with currently available materials and components. SSH-ADC technology is scalable to bandwidths over 100 GHz with recently developed SSH materials. While the SSH-ADC is a transient digitizer, the spatial parallelism of SSH materials can be utilized to enable continuous digitization

Broadband analog to digital conversion with spatial-spectral holography

Energy Technology Data Exchange (ETDEWEB)

Babbitt, W. Randall [Spectrum Lab, Montana State University, Bozeman, MT 59717-3510 (United States)]. E-mail: babbitt@physics.montana.edu; Neifeld, Mark A. [Spectrum Lab, Montana State University, Bozeman, MT 59717-3510 (United States); Merkel, Kristian D. [Spectrum Lab, Montana State University, Bozeman, MT 59717-3510 (United States)

2007-11-15

A new approach to broadband photonic-assisted analog-to-digital converter (ADC) technology is proposed and analyzed. The core of the device is a spatial spectral holographic (SSH) material, which can directly record the signals of interest in the frequency domain. An SSH-ADC acts as a frequency-domain stretch processor, which leverages the high performance of conventional ADCs by converting high bandwidth input signals to low bandwidth output signals without loss of information. Analysis of a 10 GHz bandwidth SSH-ADC predicts that 10-bit performance can be achieved with currently available materials and components. SSH-ADC technology is scalable to bandwidths over 100 GHz with recently developed SSH materials. While the SSH-ADC is a transient digitizer, the spatial parallelism of SSH materials can be utilized to enable continuous digitization.

Quality assessment of the digitalization process of analog x-ray images

International Nuclear Information System (INIS)

Georgieva, D.

2014-01-01

Computer-assisted diagnosis enabled doctors for a second point-of-view on the test results. This improves the diseases' early detection and significantly reduces the chance of errors. These methods very nicely complemented the possibilities of digital medical imaging apparatus, but in analog images their applicability and results entirely depend on the quality of analog images digitalisation. Today many standards and remarks for good practices discuss the digital apparatus image quality but the digitalisation process of analog medical images is not a part of them. Medical imaging apparatus have become digital, but within an entirely digital medical environment is necessary for their ability to blend with the old analog medical imaging carriers. The life of patients doesn't start with the beginning of digital era and for the aim of tracking diseases it is necessary to use the new digital images as well as older analog ones. For the generation of 40-50 years a large archive of images is piled up, which should be accounted of in the diagnosis process. This article is the author's study of the digitalized image quality problem. It offers a new approach to the x-ray image digitalisation - getting the HDR-image by optical sensor. After the HDR-image generation method offers to be used a digital signal processing to improve the quality of the final 16 bit gray scale medical image. The new method for medical image enhancement is proposed - it improves the image contrast, it increases or preserves the dynamic range and it doesn't lead to the loss of small low contrast structures in the image. Key words: Quality of Digital X-Rays Images

Ping-Pong Beam Training with Hybrid Digital-Analog Antenna Arrays

DEFF Research Database (Denmark)

Manchón, Carles Navarro; Carvalho, Elisabeth De; Andersen, Jørgen Bach

2017-01-01

In this article we propose an iterative training scheme that approximates optimal beamforming between two transceivers equipped with hybrid digital-analog antenna arrays. Inspired by methods proposed for digital arrays that exploit algebraic power iterations, the proposed training procedure...... is based on a series of alternate (ping-pong) transmissions between the two devices over a reciprocal channel. During the transmissions, the devices updates their digital beamformers by conjugation and normalization operations on the received digital signal, while the analog beamformers are progressively...

Design rules for superconducting analog-digital transducers; Entwurfsregeln fuer Supraleitende Analog-Digital-Wandler

Energy Technology Data Exchange (ETDEWEB)

Haddad, Taghrid

2015-05-29

This Thesis is a contribution for dimensioning aspects of circuits designs in superconductor electronics. Mainly superconductor comparators inclusive Josephson comparators as well as QOJS-Comparators are investigated. Both types were investigated in terms of speed and sensitivity. The influence of the thermal noise on the decision process of the comparators represent in so called gray zone, which is analysed in this thesis. Thereby, different relations between design parameters were derived. A circuit model of the Josephson comparator was verified by experiments. Concepts of superconductor analog-to-digital converters, which are based on above called comparators, were investigated in detail. From the comparator design rules, new rules for AD-converters were derived. Because of the reduced switching energy, the signal to noise ratio (SNR) of the circuits is affected and therefore the reliability of the decision-process is affected. For special applications with very demanding requirements in terms of the speed and accuracy superconductor analog-to-digital converters offer an excellent performance. This thesis provides relations between different design paramenters and shows resulting trade-offs, This method is transparent and easy to transfer to other circuit topologies. As a main result, a highly predictive tool for dimensioning of superconducting ADC's is proved.

Multiple-Ring Digital Communication Network

Science.gov (United States)

Kirkham, Harold

1992-01-01

Optical-fiber digital communication network to support data-acquisition and control functions of electric-power-distribution networks. Optical-fiber links of communication network follow power-distribution routes. Since fiber crosses open power switches, communication network includes multiple interconnected loops with occasional spurs. At each intersection node is needed. Nodes of communication network include power-distribution substations and power-controlling units. In addition to serving data acquisition and control functions, each node acts as repeater, passing on messages to next node(s). Multiple-ring communication network operates on new AbNET protocol and features fiber-optic communication.

Comparing Analog and Digital Hearing Aids in Reducing Hearing Disability

Directory of Open Access Journals (Sweden)

Ghassem Mohammad Khani

2004-06-01

Full Text Available Objective: Comparing analog and digital hearing aids reducing disability caused by hearing deficiency among moderate to severe sensorineural hearing-impaired persons. Method and Material: This descriptive-analytic study was carried out on two groups of subjects participated in this study in some audiology clinics of hearing aid since May 2002 to October 2003. Twenty subjects wore analog hearing aids and twenty one subjects wore digital hearing aids. In this study , no subject had previous middle ear or psychological problems. APHAB questionnaire was completed before using hearing aid and 2 months after to determine benefit of hearing aid use. Results: Total score mean of APHAB inventory before and after use of analoge hearing aids were 52.215+6.420 and 32.300+3.443 respectively. Also total score mean of APHAB inventory before and after use of digital hearing aids were 54.9252+9.028 and 26.321+10.916 respectively. There was no significant difference between total mean score of APHAB inventory before and after using analog and digital hearing aids (P=0.058.While there was significant difference between total mean score of APHAB questionnaire before and after use of analog hearing aids (P<0.001 and also before and after use of digital hearing aids (P<0.001. Moreover age, gender , litracy level , occupation , degree of hearing loss and manner of hearing aid usage did not have significant effect on APHAB results. Configuration of loss had siginficant effect on aversiveness subscale before and after use of analog hearing aids (P=0.008. Previous experience and duration of hearing aid usage had significant effect on aversiveness subscale before and after use of digital hearing aids (P=0.043 and (P=0.024, respectively , while all of these three items did not have significant effect on total mean score of APHAB inventory and also total mean scores of three subscales of ease of communication , reverberation and background noise. Conclusion: Comparing to

Regulatory requirements for replacement of analog systems with digital upgrades

International Nuclear Information System (INIS)

Loeser, P.J.

1993-01-01

This paper reviews briefly the regulatory guidelines which must be met in order to replace analog systems in nuclear power plants with digital systems. There is a move to do such replacements for a number of reasons: analog systems are aging, and showing considerable drift; few vendors manufacture analog systems today; support and parts are hard to get; digital systems provide flexibility. There is a safety concern however about undesirable and unpredictable effects to digital safety equipment due to plant transients, accidents, post-accident condition, and EMI/RF environmental interferences. License holders must comply with the requirements of 10 C.F.R. 50.59, which deals with safety concerns with respect to any changes to operating plants which may have an impact on the safety of the plant. NRC staff is taking the position that all digital upgrades will require an evaluation under this regulation

Congested Link Inference Algorithms in Dynamic Routing IP Network

Directory of Open Access Journals (Sweden)

Yu Chen

2017-01-01

Full Text Available The performance descending of current congested link inference algorithms is obviously in dynamic routing IP network, such as the most classical algorithm CLINK. To overcome this problem, based on the assumptions of Markov property and time homogeneity, we build a kind of Variable Structure Discrete Dynamic Bayesian (VSDDB network simplified model of dynamic routing IP network. Under the simplified VSDDB model, based on the Bayesian Maximum A Posteriori (BMAP and Rest Bayesian Network Model (RBNM, we proposed an Improved CLINK (ICLINK algorithm. Considering the concurrent phenomenon of multiple link congestion usually happens, we also proposed algorithm CLILRS (Congested Link Inference algorithm based on Lagrangian Relaxation Subgradient to infer the set of congested links. We validated our results by the experiments of analogy, simulation, and actual Internet.

Principles of digital and analog communications

CERN Document Server

Gibson, Jerry D

1993-01-01

This textbook for the first course in communications covers analog and digital systems and emphasizes digital communications. It covers data transmission, signal space, optimal receivers, and pulse code modulation, and includes readable treatments of coded modulation and continuous phase modulation. Advanced mathematics is kept to a minimum-Fourier series, Fourier transforms, linear systems, random variables, and stochastic process are described thoroughly. It includes data compression of speech and images and a full chapter coverage of information theory, rate distortion theory and coded modulation. It relates digital communications theory to current practice and covers digital communications over band-width constrained channels, including pulse shaping and equilization. -- Dieser Text bezieht sich auf eine vergriffene oder nicht verfügbare Ausgabe dieses Titels.

Bandwidth tunable microwave photonic filter based on digital and analog modulation

Science.gov (United States)

Zhang, Qi; Zhang, Jie; Li, Qiang; Wang, Yubing; Sun, Xian; Dong, Wei; Zhang, Xindong

2018-05-01

A bandwidth tunable microwave photonic filter based on digital and analog modulation is proposed and experimentally demonstrated. The digital modulation is used to broaden the effective gain spectrum and the analog modulation is to get optical lines. By changing the symbol rate of data pattern, the bandwidth is tunable from 50 MHz to 700 MHz. The interval of optical lines is set according to the bandwidth of gain spectrum which is related to the symbol rate. Several times of bandwidth increase are achieved compared to a single analog modulation and the selectivity of the response is increased by 3.7 dB compared to a single digital modulation.

Online Activities, Digital Media Literacy, and Networked Individualism of Korean Youth

Science.gov (United States)

Park, Sora; Kim, Eun-mee; Na, Eun-Yeong

2015-01-01

Networked individualism enables Internet users to connect and socialize via their loose and transient multiple networks, whereas digital media literacy is a precondition of effective Internet use. In this study, an attempt has been made to find the link between networked individualism, digital media literacy, and young people's perception of their…

New technologies for radiation-hardening analog to digital converters

International Nuclear Information System (INIS)

Gauthier, M.K.

1982-12-01

Surveys of available Analog to Digital Converters (ADC) suitable for precision applications showed that none have the proper combination of accuracy and radiation hardness to meet space and/or strategic weapon requirements. A development program which will result in an ADC device which will serve a number of space and strategic applications. Emphasis was placed on approaches that could be integrated onto a single chip within three to five years

New technologies for radiation-hardening analog to digital converters

Science.gov (United States)

Gauthier, M. K.

1982-01-01

Surveys of available Analog to Digital Converters (ADC) suitable for precision applications showed that none have the proper combination of accuracy and radiation hardness to meet space and/or strategic weapon requirements. A development program which will result in an ADC device which will serve a number of space and strategic applications. Emphasis was placed on approaches that could be integrated onto a single chip within three to five years.

Memristor-Based Analog Computation and Neural Network Classification with a Dot Product Engine.

Science.gov (United States)

Hu, Miao; Graves, Catherine E; Li, Can; Li, Yunning; Ge, Ning; Montgomery, Eric; Davila, Noraica; Jiang, Hao; Williams, R Stanley; Yang, J Joshua; Xia, Qiangfei; Strachan, John Paul

2018-03-01

Using memristor crossbar arrays to accelerate computations is a promising approach to efficiently implement algorithms in deep neural networks. Early demonstrations, however, are limited to simulations or small-scale problems primarily due to materials and device challenges that limit the size of the memristor crossbar arrays that can be reliably programmed to stable and analog values, which is the focus of the current work. High-precision analog tuning and control of memristor cells across a 128 × 64 array is demonstrated, and the resulting vector matrix multiplication (VMM) computing precision is evaluated. Single-layer neural network inference is performed in these arrays, and the performance compared to a digital approach is assessed. Memristor computing system used here reaches a VMM accuracy equivalent of 6 bits, and an 89.9% recognition accuracy is achieved for the 10k MNIST handwritten digit test set. Forecasts show that with integrated (on chip) and scaled memristors, a computational efficiency greater than 100 trillion operations per second per Watt is possible. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

An integrated analog O/E/O link for multi-channel laser neurons

Energy Technology Data Exchange (ETDEWEB)

Nahmias, Mitchell A., E-mail: mnahmias@princeton.edu; Tait, Alexander N.; Tolias, Leonidas; Chang, Matthew P.; Ferreira de Lima, Thomas; Shastri, Bhavin J.; Prucnal, Paul R. [Electrical Engineering Department, Princeton University, 41 Olden St, Princeton, New Jersey 08540 (United States)

2016-04-11

We demonstrate an analog O/E/O electronic link to allow integrated laser neurons to accept many distinguishable, high bandwidth input signals simultaneously. This device utilizes wavelength division multiplexing to achieve multi-channel fan-in, a photodetector to sum signals together, and a laser cavity to perform a nonlinear operation. Its speed outpaces accelerated-time neuromorphic electronics, and it represents a viable direction towards scalable networking approaches.

Mismatch-Shaping Serial Digital-to-Analog Converter

DEFF Research Database (Denmark)

Steensgaard-Madsen, Jesper; Moon, Un-Ku; Temes, Gabor C.

1999-01-01

A simple but accurate pseudo-passive mismatch-shaping D/A converter is described. A digital state machine is used to control the switching sequence of a symmetric two-capacitor network that performs the D/A conversion. The error caused by capacitor mismatch is uncorrelated with the input signal...

A 13-Bits wilkinson analog-digital converter for NIM acquisition system

International Nuclear Information System (INIS)

Acosta Toledo, R.; Osorio Deliz, J.; Arista Romeu, E.; Fernandez, J.

1994-01-01

A new 13-bits Wilkinson analog-digital converter is described. The aim of this work is to describe the circuits of sample and hold, memory condensator loading and releasing PROM based control memory logic, zero level detection and correction. The converter is designed for the digital measurement of the peak amplitudes of pulses with statistical or periodical time distribution. The analog-digital converter may be used in spectrometric systems, multi-channel analysers or any similar PC based system

Epistemic Function and Ontology of Analog and Digital Images

Directory of Open Access Journals (Sweden)

Aleksandra Łukaszewicz Alcaraz

2016-01-01

Full Text Available The important epistemic function of photographic images is their active role in construction and reconstruction of our beliefs concerning the world and human identity, since we often consider photographs as presenting reality or even the Real itself. Because photography can convince people of how different social and ethnic groups and even they themselves look, documentary projects and the dissemination of photographic practices supported the transition from disciplinary society to the present-day society of control. While both analog and digital images are formed from the same basic materia, the ways in which this matter appears are distinctive. In the case of analog photography, we deal with physical and chemical matter, whereas with digital images we face electronic matter. Because digital photography allows endless modification of the image, we can no longer believe in the truthfulness of digital images.

Optical Injection Locking of Vertical Cavity Surface-Emitting Lasers: Digital and Analog Applications

Science.gov (United States)

Parekh, Devang

With the rise of mobile (cellphones, tablets, notebooks, etc.) and broadband wireline communications (Fiber to the Home), there are increasing demands being placed on transmitters for moving data from device to device and around the world. Digital and analog fiber-optic communications have been the key technology to meet this challenge, ushering in ubiquitous Internet and cable TV over the past 20 years. At the physical layer, high-volume low-cost manufacturing of semiconductor optoelectronic devices has played an integral role in allowing for deployment of high-speed communication links. In particular, vertical cavity surface emitting lasers (VCSEL) have revolutionized short reach communications and are poised to enter more markets due to their low cost, small size, and performance. However, VCSELs have disadvantages such as limited modulation performance and large frequency chirp which limits fiber transmission speed and distance, key parameters for many fiber-optic communication systems. Optical injection locking is one method to overcome these limitations without re-engineering the VCSEL at the device level. By locking the frequency and phase of the VCSEL by the direct injection of light from another laser oscillator, improved device performance is achieved in a post-fabrication method. In this dissertation, optical injection locking of VCSELs is investigated from an applications perspective. Optical injection locking of VCSELs can be used as a pathway to reduce complexity, cost, and size of both digital and analog fiber-optic communications. On the digital front, reduction of frequency chirp via bit pattern inversion for large-signal modulation is experimentally demonstrated showing up to 10 times reduction in frequency chirp and over 90 times increase in fiber transmission distance. Based on these results, a new reflection-based interferometric model for optical injection locking was established to explain this phenomenon. On the analog side, the resonance

Phase-locked loops. [in analog and digital circuits communication system

Science.gov (United States)

Gupta, S. C.

1975-01-01

An attempt to systematically outline the work done in the area of phase-locked loops which are now used in modern communication system design is presented. The analog phase-locked loops are well documented in several books but discrete, analog-digital, and digital phase-locked loop work is scattered. Apart from discussing the various analysis, design, and application aspects of phase-locked loops, a number of references are given in the bibliography.

Analog and digital dividers for mass spectrometers

International Nuclear Information System (INIS)

Osipov, A.K.

1980-01-01

Errors of four different types of stress dividers used in statical mass-spectrometers for determination of mass number by accelerating stress are analyzed. The simplest flowsheet of the analog divider comprises operation amplifier, in the chain of the negative feedback of which a multiplication device on differential cascade is switched- in. This analog divider has high sensitivity to temperature and high error approximately 5%. Application of the multiplier on differential cascade with normalization permits to increase temperature stability and decrease the error up to 1%. Another type of the analog divider is a logarithmic divider the error of which is constant within the whole operation range and it constitutes 1-5%. The digital divider with a digital-analog transformer (DAT) has the error of +-0.015% which is determined by the error of detectors and resistance of keys in the locked state. Considered is the design of a divider based on transformation of the inlet stress into the time period. The error of the divider is determined in this case mainly by stress of the zero shift of the operation amplifier (it should be compensated) and relative threshold stability of the comparator triggering which equals (2-3)x10 -4 . It is noted that the divider with DAT application and the divider with the use of stress transformation within the time period are most perspective ones for statical mass-spectrometers [ru

Analog and digital appliance technology for the control and monitoring of space HVAC systems

Energy Technology Data Exchange (ETDEWEB)

Gyoeri, M

1987-01-01

Both analog and digital devices are expected to meet the required control functions. The analog control device meets this function by way of a complicated circuitry and wiring technology of varying sophistication. In the digital control by a preprogrammed microprocessor. Digital technology allows to use the copied programme in different devices. Any change in the control of a system can be implemented and met by a programme change in digital technology. In analog technology, this change involves a change in wiring. (orig./HW).

Analysis of Recurrent Analog Neural Networks

Directory of Open Access Journals (Sweden)

Z. Raida

1998-06-01

Full Text Available In this paper, an original rigorous analysis of recurrent analog neural networks, which are built from opamp neurons, is presented. The analysis, which comes from the approximate model of the operational amplifier, reveals causes of possible non-stable states and enables to determine convergence properties of the network. Results of the analysis are discussed in order to enable development of original robust and fast analog networks. In the analysis, the special attention is turned to the examination of the influence of real circuit elements and of the statistical parameters of processed signals to the parameters of the network.

Networked Airborne Communications Using Adaptive Multi Beam Directional Links

Science.gov (United States)

2016-03-05

Networked Airborne Communications Using Adaptive Multi-Beam Directional Links R. Bruce MacLeod Member, IEEE, and Adam Margetts Member, IEEE MIT...provide new techniques for increasing throughput in airborne adaptive directional net- works. By adaptive directional linking, we mean systems that can...techniques can dramatically increase the capacity in airborne networks. Advances in digital array technology are beginning to put these gains within reach

Doubling-resolution analog-to-digital conversion based on PIC18F45K80

Directory of Open Access Journals (Sweden)

Yueyang Yuan

2014-08-01

Full Text Available Aiming at the analog signal being converted into the digital with a higher precision, a method to improve the analog-to-digital converter (ADC resolution is proposed and described. Based on the microcomputer PIC18F45K80 in which the internal ADC modules are embedded, a circuit is designed for doubling the resolution of ADC. According to the circuit diagram, the mathematical formula for calculating this resolution is derived. The corresponding software and print circuit board assembly is also prepared. With the experiment, a 13 bit ADC is achieved based on the 12 bit ADC module predesigned in the PIC18F45K80.

Very High-Performance Advanced Filter Bank Analog-to-Digital Converter (AFB ADC) Project

National Research Council Canada - National Science Library

Velazquez, Scott

1999-01-01

... of the art by using a parallel array of individual commercial off the shelf converters. The significant performance improvements afforded by the Advanced Filter Bank Analog to Digital Converter (AFB ADC...

On automatic synthesis of analog/digital circuits

Energy Technology Data Exchange (ETDEWEB)

Beiu, V.

1998-12-31

The paper builds on a recent explicit numerical algorithm for Kolmogorov`s superpositions, and will show that in order to synthesize minimum size (i.e., size-optimal) circuits for implementing any Boolean function, the nonlinear activation function of the gates has to be the identity function. Because classical and--or implementations, as well as threshold gate implementations require exponential size, it follows that size-optimal solutions for implementing arbitrary Boolean functions can be obtained using analog (or mixed analog/digital) circuits. Conclusions and several comments are ending the paper.

Methodology for the digital calibration of analog circuits and systems with case studies

CERN Document Server

Pastre, Marc

2006-01-01

Methodology for the Digital Calibration of Analog Circuits and Systems shows how to relax the extreme design constraints in analog circuits, allowing the realization of high-precision systems even with low-performance components. A complete methodology is proposed, and three applications are detailed. To start with, an in-depth analysis of existing compensation techniques for analog circuit imperfections is carried out. The M/2+M sub-binary digital-to-analog converter is thoroughly studied, and the use of this very low-area circuit in conjunction with a successive approximations algorithm for digital compensation is described. A complete methodology based on this compensation circuit and algorithm is then proposed. The detection and correction of analog circuit imperfections is studied, and a simulation tool allowing the transparent simulation of analog circuits with automatic compensation blocks is introduced. The first application shows how the sub-binary M/2+M structure can be employed as a conventional di...

Large-scale digitizer system, analog converters

International Nuclear Information System (INIS)

Althaus, R.F.; Lee, K.L.; Kirsten, F.A.; Wagner, L.J.

1976-10-01

Analog to digital converter circuits that are based on the sharing of common resources, including those which are critical to the linearity and stability of the individual channels, are described. Simplicity of circuit composition is valued over other more costly approaches. These are intended to be applied in a large-scale processing and digitizing system for use with high-energy physics detectors such as drift-chambers or phototube-scintillator arrays. Signal distribution techniques are of paramount importance in maintaining adequate signal-to-noise ratio. Noise in both amplitude and time-jitter senses is held sufficiently low so that conversions with 10-bit charge resolution and 12-bit time resolution are achieved

Simulation of Controller Pilot Data Link Communications over VHF Digital Link Mode 3

Science.gov (United States)

Bretmersky, Steven C.; Murawski, Robert; Nguyen, Thanh C.; Raghavan, Rajesh S.

2004-01-01

The Federal Aviation Administration (FAA) has established an operational plan for the future Air Traffic Management (ATM) system, in which the Controller Pilot Data Link Communications (CPDLC) is envisioned to evolve into digital messaging that will take on an ever increasing role in controller to pilot communications, significantly changing the way the National Airspace System (NAS) is operating. According to FAA, CPDLC represents the first phase of the transition from the current analog voice system to an International Civil Aviation Organization (ICAO) compliant system in which digital communication becomes the alternate and perhaps primary method of routine communication. The CPDLC application is an Air Traffic Service (ATS) application in which pilots and controllers exchange messages via an addressed data link. CPDLC includes a set of clearance, information, and request message elements that correspond to existing phraseology employed by current Air Traffic Control (ATC) procedures. These message elements encompass altitude assignments, crossing constraints, lateral deviations, route changes and clearances, speed assignments, radio frequency assignments, and various requests for information. The pilot is provided with the capability to respond to messages, to request clearances and information, to report information, and to declare/rescind an emergency. A 'free text' capability is also provided to exchange information not conforming to defined formats. This paper presents simulated results of the aeronautical telecommunication application Controller Pilot Data Link Communications over VHF Digital Link Mode 3 (VDL Mode 3). The objective of this simulation study was to determine the impact of CPDLC traffic loads, in terms of timely message delivery and capacity of the VDL Mode 3 subnetwork. The traffic model is based on and is used for generating air/ground messages with different priorities. Communication is modeled for the en route domain of the Cleveland

A simple method of digitizing analog scintigrams for quantification and digital archiving. Eine einfache Methode der Digitalisierung von Analogszintigrammen zur Quantifizierung und digitalen Archivierung

Energy Technology Data Exchange (ETDEWEB)

Schramm, M. (Klinik fuer Nuklearmedizin, Kiel Univ. (Germany)); Kaempfer, B. (Klinik fuer Nuklearmedizin, Kiel Univ. (Germany)); Wolf, H. (Klinik fuer Nuklearmedizin, Kiel Univ. (Germany)); Clausen, M. (Klinik fuer Nuklearmedizin, Kiel Univ. (Germany)); Wendhausen, H. (Klinik fuer Nuklearmedizin, Kiel Univ. (Germany)); Henze, E. (Klinik fuer Nuklearmedizin, Kiel Univ. (Germany))

1993-02-01

This study was undertaken to evaluate a quick, reliable and cheap method of digitizing analog scintigrams. 40 whole-body bone scintigrams were obtained simultaneously in analog and genuine digital format. The analog scans on X-ray film were then digitized seecondarily by three different methods: 300 dpi flatbed scanning, high-resolution camera scanning and camcorder recording. A simple exposure approach using a light box, a cheap camcorder, a PC and image grabber hard- and software proved to be optimal. Visual interpretation showed no differences in clinical findings when comparing the analog images with their secondarily digitized counterparts. To test the possibility of quantification, 126 equivalent ROIs were drawn both in the genuine digital and the secondarily digitized images. Comparing the ROI count to whole-body count percentage of the corresponding ROIs showed the correlation to be linear. The evaluation of phantom studies showed the linear correlation to be true within a wide activity range. Thus, secondary digitalization of analog scintigrams is an easy, cheap and reliable method of archiving images and allows secondary digital quantification. (orig.)

Development of reconfigurable analog and digital circuits for plasma diagnostics measurement systems

International Nuclear Information System (INIS)

Srivastava, Amit Kumar; Sharma, Atish; Raval, Tushar

2009-01-01

In long pulse discharge tokamak, a large number of diagnostic channels are being used to understand the complex behavior of plasma. Different diagnostics demand different types of analog and digital processing for plasma parameters measurement. This leads to variable requirements of signal processing for diagnostic measurement. For such types of requirements, we have developed hardware with reconfigurable electronic devices, which provide flexible solution for rapid development of measurement system. Here the analog processing is achieved by Field Programmable Analog Array (FPAA) integrated circuit while reconfigurable digital devices (CPLD/FPGA) achieve digital processing. FPAA's provide an ideal integrated platform for implementing low to medium complexity analog signal processing. With dynamic reconfigurability, the functionality of the FPAA can be reconfigured in-system by the designer or on the fly by a microprocessor. This feature is quite useful to manipulate the tuning or the construction of any part of the analog circuit without interrupting operation of the FPAA, thus maintaining system integrity. The hardware operation control logic circuits are configured in the reconfigurable digital devices (CPLD/FPGA) to control proper hardware functioning. These reconfigurable devices provide the design flexibility and save the component space on the board. It also provides the flexibility for various setting through software. The circuit controlling commands are either issued by computer/processor or generated by circuit itself. (author)

Environmental testing of an experimental digital safety channel

International Nuclear Information System (INIS)

Korsah, K.; Tanaka, T.J.; Wilson, T.L. Jr.; Wood, R.T.

1996-09-01

This document presents the results of environmental stress tests performed on an experimental digital safety channel (EDSC) assembled at the Oak Ridge National Laboratory (ORNL) as part of the NRC-sponsored Qualification of Advanced Instrumentation and Controls (W) System program. The objective of this study is to investigate failure modes and vulnerabilities of microprocessor-based technologies when subjected to environmental stressors. The study contributes to the technical basis for environmental qualification of safety-related digital I ampersand C systems. The EDSC employs technologies and digital subsystems representative of those proposed for use in advanced light-water reactors (ALWRs) or for retrofits in existing plants. Subsystems include computers, electrical and optical serial communication links, fiber-optic network links, analog-to-digital and digital-to-analog converters, and multiplexers. The EDSC was subjected to selected stressors that are a potential risk to digital equipment in a mild environment. The selected stressors were electromagnetic and radio-frequency interference (EMYRFI), temperature, humidity, and smoke exposure. The stressors were applied over ranges that were considerably higher than what the channel is likely to experience in a normal nuclear power plant environment. Ranges of stress were selected at a sufficiently high level to induce errors so that failure modes that are characteristic of the technologies employed could be identified

The RHIC general purpose multiplexed analog to digital converter system

International Nuclear Information System (INIS)

Michnoff, R.

1995-01-01

A general purpose multiplexed analog to digital converter system is currently under development to support acquisition of analog signals for the Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory. The system consists of a custom intelligent VME based controller module (V113) and a 14-bit 64 channel multiplexed A/D converter module (V114). The design features two independent scan groups, where one scan group is capable of acquiring 64 channels at 60 Hz, concurrently with the second scan group acquiring data at an aggregate rate of up to 80 k samples/second. An interface to the RHIC serially encoded event line is used to synchronize acquisition. Data is stored in a circular static RAM buffer on the controller module, then transferred to a commercial VMEbus CPU board and higher level workstations for plotting, report Generation, analysis and storage

Hybrid digital-analog coding with bandwidth expansion for correlated Gaussian sources under Rayleigh fading

Science.gov (United States)

Yahampath, Pradeepa

2017-12-01

Consider communicating a correlated Gaussian source over a Rayleigh fading channel with no knowledge of the channel signal-to-noise ratio (CSNR) at the transmitter. In this case, a digital system cannot be optimal for a range of CSNRs. Analog transmission however is optimal at all CSNRs, if the source and channel are memoryless and bandwidth matched. This paper presents new hybrid digital-analog (HDA) systems for sources with memory and channels with bandwidth expansion, which outperform both digital-only and analog-only systems over a wide range of CSNRs. The digital part is either a predictive quantizer or a transform code, used to achieve a coding gain. Analog part uses linear encoding to transmit the quantization error which improves the performance under CSNR variations. The hybrid encoder is optimized to achieve the minimum AMMSE (average minimum mean square error) over the CSNR distribution. To this end, analytical expressions are derived for the AMMSE of asymptotically optimal systems. It is shown that the outage CSNR of the channel code and the analog-digital power allocation must be jointly optimized to achieve the minimum AMMSE. In the case of HDA predictive quantization, a simple algorithm is presented to solve the optimization problem. Experimental results are presented for both Gauss-Markov sources and speech signals.

Performance Effects of Display Incogruity in a Digital and Analog Clock Reading Task

Science.gov (United States)

Comstock, J. Raymond, Jr.; Derks, Peter L.

2004-01-01

In an era of increasing automation, it is important to design displays and input devices that minimize human error. In this context, information concerning the human response to the detection of incongruous information is important. Such incongruous information can be operationalized as unexpected (perhaps erroneous) information on which a decision by the human or operation by an automated system is based. In the aviation environment, decision making when faced with inadequate, incomplete, or incongruous information may occur in a failure scenario. An additional challenge facing the human operator in automated environments is maintaining alertness or vigilance. The vigilance issue is of particular concern as a factor that may interact with performance when faced with inadequate, incomplete, or incongruous information. From the literature on eye-scan behavior we know that the time spent looking at a particular display or indicator is a function of the type of information one is trying to discern from the display. For example, quick glances are all it takes for confirming that an indicator is in a normal position or range, whereas a continuous look of several seconds may be required for confirmation that a complex control input is having the desired effect. Important to consider is that while an extended look takes place, visual input from other sources may be missed. Much like an extended look, the interpretation of incongruous information may require extra time. The present experiment was designed to explore the performance consequences of a decision making task when incongruous information was presented. For this experiment a display incongruity was created on a subset of trials of a clock reading laboratory task. Display incongruity was made possible through presentation of 'impossible' times (e.g. 1:65 or 11:90). Subjects made 'same' 'different' decisions and keyboard responses to pairings of Analog-Analog (AA), Digital-Digital (DD), and Analog- Digital (AD

Signal-to-noise ratio estimation in digital computer simulation of lowpass and bandpass systems with applications to analog and digital communications, volume 3

Science.gov (United States)

Tranter, W. H.; Turner, M. D.

1977-01-01

Techniques are developed to estimate power gain, delay, signal-to-noise ratio, and mean square error in digital computer simulations of lowpass and bandpass systems. The techniques are applied to analog and digital communications. The signal-to-noise ratio estimates are shown to be maximum likelihood estimates in additive white Gaussian noise. The methods are seen to be especially useful for digital communication systems where the mapping from the signal-to-noise ratio to the error probability can be obtained. Simulation results show the techniques developed to be accurate and quite versatile in evaluating the performance of many systems through digital computer simulation.

Digital to analog resistive switching transition induced by graphene buffer layer in strontium titanate based devices.

Science.gov (United States)

Wan, Tao; Qu, Bo; Du, Haiwei; Lin, Xi; Lin, Qianru; Wang, Da-Wei; Cazorla, Claudio; Li, Sean; Liu, Sidong; Chu, Dewei

2018-02-15

Resistive switching behaviour can be classified into digital and analog switching based on its abrupt and gradual resistance change characteristics. Realizing the transition from digital to analog switching in the same device is essential for understanding and controlling the performance of the devices with various switching mechanisms. Here, we investigate the resistive switching in a device made with strontium titanate (SrTiO 3 ) nanoparticles using X-ray diffractometry, scanning electron microscopy, Raman spectroscopy, and direct electrical measurements. It is found that the well-known rupture/formation of Ag filaments is responsible for the digital switching in the device with Ag as the top electrode. To modulate the switching performance, we insert a reduced graphene oxide layer between SrTiO 3 and the bottom FTO electrode owing to its good barrier property for the diffusion of Ag ions and high out-of-plane resistance. In this case, resistive switching is changed from digital to analog as determined by the modulation of interfacial resistance under applied voltage. Based on that controllable resistance, potentiation and depression behaviours are implemented as well. This study opens up new ways for the design of multifunctional devices which are promising for memory and neuromorphic computing applications. Copyright © 2017 Elsevier Inc. All rights reserved.

Comparison of digital selenium radiography with an analog screen-film system in the diagnostic process of pneumoconiosis according to ILO classification

International Nuclear Information System (INIS)

Zaehringer, M.; Winnekendonk, G.; Gossmann, A.; Krueger, K.; Krug, B.

2001-01-01

Purpose: The aim of the study was to determine the diagnostic value of digital selenium radiography in patients with pneumoconiosis. For this purpose chest X-rays by digital selenium radiography and analog screen-film system were compared according to the ILO classification of pneumoconiosis. Method: After approval of the study by the local ethic commission and the Federal German Office for Radiation Protection 50 patients were subjected to X-rays by digital selenium radiography (Thoravision; Philips Medical Systems, Hamburg, Germany) and analog screen-film system of the same day within the scope of an industrial medicine preventive checkup. Four investigators rated the chest X-rays according to the ILO classification of pneumoconiosis. Results: The findings demonstrated by chest X-rays according to ILO classification were rated similar by digital selenium radiography and analog screen film systems. Image quality of the digital pictures was rated significantly better. Conclusion: The use of digital selenium radiography in evaluating chest X-rays according to the ILO classification does not result in over- or underestimation of pulmonary pathologies. Hence, in the diagnosis of pneumoconiosis, digital selenium radiography can replace the tested analog screen-film system. (orig.) [de

A digital calibration technique for an ultra high-speed wide-bandwidth folding and interpolating analog-to-digital converter in 0.18-{mu}m CMOS technology

Energy Technology Data Exchange (ETDEWEB)

Yu Jinshan; Zhang Ruitao; Zhang Zhengping; Wang Yonglu; Zhu Can; Zhang Lei; Yu Zhou; Han Yong, E-mail: yujinshan@yeah.net [National Laboratory of Analog IC' s, Chongqing 400060 (China)

2011-01-15

A digital calibration technique for an ultra high-speed folding and interpolating analog-to-digital converter in 0.18-{mu}m CMOS technology is presented. The similar digital calibration techniques are taken for high 3-bit flash converter and low 5-bit folding and interpolating converter, which are based on well-designed calibration reference, calibration DAC and comparators. The spice simulation and the measured results show the ADC produces 5.9 ENOB with calibration disabled and 7.2 ENOB with calibration enabled for high-frequency wide-bandwidth analog input. (semiconductor integrated circuits)

Comparative study of digital laser film and analog paper image recordings

International Nuclear Information System (INIS)

Lee, K.R.; Cox, G.G.; Templeton, A.W.; Preston, D.F.; Anderson, W.H.; Hensley, K.S.; Dwyer, S.J.

1987-01-01

The increase in the use of various imaging modalities demands higher quality and more efficacious analog image recordings. Laser electronic recordings with digital array prints of 4,000 x 5,000 x 12 bits obtained using laser-sensitive film or paper are being evaluated. Dry silver paper recordings are being improved and evaluated. High-resolution paper dot printers are being studied to determine their gray-scale capabilities. The authors evaluated the image quality, costs, clinical utilization, and acceptability of CT scans, MR images, digital subtraction angiograms, digital radiographs, and radionuclide scans recorded by seven different printers (three laser, three silver paper, and one dot) and compared the same features in conventional film recording. This exhibit outlines the technical developments and instrumentation of digital laser film and analog paper recorders and presents the results of the study

Design of a 12-bit 80MS/s pipeline analog-to-digital converter for PLC-VDSL applications

Science.gov (United States)

Ruiz-Amaya, Jesus; Delgado-Restituto, Manuel; Fernandez-Bootello, Juan F.; de la Rosa, Jose M.

2005-06-01

This paper describes the design of a 12-bit 80MS/s pipeline Analog-to-Digital converter implemented in 0.13mm CMOS logic technology. The design has been computer-aided by a developed toolbox for the simulation, synthesis and verification of Nyquist-Rate Analog-to-Digital and Digital-to-Analog Converters in MATLAB. The embedded simulator uses SIMULINK C-coded S-functions to model all required subcircuits including their main error mechanisms. This approach allows to drastically speed up the simulation CPU-time and makes the proposed tool an advantageous alternative for fast exploration of requirements and as a design validation tool. The converter is based on a 10-stage pipeline preceded by a sample/hold with bootstrapping technique. Each stage gives 1.5 effective bits, except for the first one which provides 2.5 effective bits to improve linearity. The Analog-to-Digital architecture uses redundant bits for digital correction, it is planned to be implemented without using calibration and employs a subranging pipeline look-ahead technique to increase speed. Substrate biased MOSFETs in the depletion region are used as capacitors, linearized by a series compensation. Simulation results show that the Multi-Tone Power Ratio is higher than 56dB for several DMT test signals and the estimated Signal-to-Noise Ratio yield is supposed to be better than 62 dB from DC to Nyquist frequency. The converter dissipates less than 150mW from a 3.3V supply and occupies less than 4 mm2 die area. The results have been checked with all process corners from -40° to 85° and power supply from 3V to 3.6V.

Digitally assisted analog beamforming for millimeter-wave communication

NARCIS (Netherlands)

Kokkeler, Andre B.J.; Smit, Gerardus Johannes Maria

2015-01-01

The paper addresses the research question on how digital beamsteering algorithms can be combined with analog beamforming in the context of millimeter-wave communication for next generation (5G) cellular systems. Key is the use of coarse quantisation of the individual antenna signals next to the

Radiation-hard analog-to-digital converters for space and strategic applications

Science.gov (United States)

Gauthier, M. K.; Dantas, A. R. V.

1985-01-01

During the course of the Jet Propulsion Laboratory's program to study radiation-hardened analog-to-digital converters (ADCs), numerous milestones have been reached in manufacturers' awareness and technology development and transfer, as well as in user awareness of these developments. The testing of ADCs has also continued with twenty different ADCs from seven manufacturers, all tested for total radiation dose and three tested for neutron effects. Results from these tests are reported.

Sampled data CT system including analog filter and compensating digital filter

International Nuclear Information System (INIS)

Glover, G. H.; DallaPiazza, D. G.; Pelc, N. J.

1985-01-01

A CT scanner in which the amount of x-ray information acquired per unit time is substantially increased by using a continuous-on x-ray source and a sampled data system with the detector. An analog filter is used in the sampling system for band limiting the detector signal below the highest frequency of interest, but is a practically realizable filter and is therefore non-ideal. A digital filter is applied to the detector data after digitization to compensate for the characteristics of the analog filter, and to provide an overall filter characteristic more nearly like the ideal

Associative memory in an analog iterated-map neural network

Science.gov (United States)

Marcus, C. M.; Waugh, F. R.; Westervelt, R. M.

1990-03-01

The behavior of an analog neural network with parallel dynamics is studied analytically and numerically for two associative-memory learning algorithms, the Hebb rule and the pseudoinverse rule. Phase diagrams in the parameter space of analog gain β and storage ratio α are presented. For both learning rules, the networks have large ``recall'' phases in which retrieval states exist and convergence to a fixed point is guaranteed by a global stability criterion. We also demonstrate numerically that using a reduced analog gain increases the probability of recall starting from a random initial state. This phenomenon is comparable to thermal annealing used to escape local minima but has the advantage of being deterministic, and therefore easily implemented in electronic hardware. Similarities and differences between analog neural networks and networks with two-state neurons at finite temperature are also discussed.

The application of high voltage digital and analogue unit protections to utility telecommunications systems

Energy Technology Data Exchange (ETDEWEB)

Farthing, H. [SNC Group, Montreal, PQ (Canada); Verzosa, Q.R.; Care, J.M. [SNC Group, Montreal, PQ (Canada)

1996-08-01

The use of fibre optic and digital microwave systems, both within and without utility communications networks was discussed. Their availability has led to the development of phase comparison and differential current relaying systems which provide enhanced protective features for transmission circuits. The application of fibre optic cable or microwave radio data links overcomes problems caused by ground potential rise and transferred potential damage in metallic pilot wire schemes. Some problems were encountered when installing digital differential current and analogue phase comparison relaying systems to a 220 kV power transmission system where a mix of analog microwave, digital microwave radio and multiplexed fibre optic channels were available. However, the relays were successfully installed with the application of digital pilot differential relays to the power system which enabled fast fault clearance to be achieved. 7 refs., 1 tab., 1 fig.

An Open-Source Tool Set Enabling Analog-Digital-Software Co-Design

Directory of Open Access Journals (Sweden)

Michelle Collins

2016-02-01

Full Text Available This paper presents an analog-digital hardware-software co-design environment for simulating and programming reconfigurable systems. The tool simulates, designs, as well as enables experimental measurements after compiling to configurable systems in the same integrated design tool framework. High level software in Scilab/Xcos (open-source programs similar to MATLAB/Simulink that converts the high-level block description by the user to blif format (sci2blif, which acts as an input to the modified VPR tool, including the code v p r 2 s w c s , encoding the specific platform through specific architecture files, resulting in a targetable switch list on the resulting configurable analog–digital system. The resulting tool uses an analog and mixed-signal library of components, enabling users and future researchers access to the basic analog operations/computations that are possible.

Iterative Signal Processing for Mitigation of Analog-to-Digital Converter Clipping Distortion in Multiband OFDMA Receivers

Directory of Open Access Journals (Sweden)

Markus Allén

2012-01-01

Full Text Available In modern wideband communication receivers, the large input-signal dynamics is a fundamental problem. Unintentional signal clipping occurs, if the receiver front-end with the analog-to-digital interface cannot respond to rapidly varying conditions. This paper discusses digital postprocessing compensation of such unintentional clipping in multiband OFDMA receivers. The proposed method iteratively mitigates the clipping distortion by exploiting the symbol decisions. The performance of the proposed method is illustrated with various computer simulations and also verified by concrete laboratory measurements with commercially available analog-to-digital hardware. It is shown that the clipping compensation algorithm implemented in a turbo decoding OFDM receiver is able to remove almost all the clipping distortion even under significant clipping in fading channel circumstances. That is to say, it is possible to nearly recover the receiver performance to the level, which would be achieved in the equivalent nonclipped situation.

Building the digital enterprise a guide to constructing monetization models using digital technologies

CERN Document Server

Skilton, Mark

2016-01-01

The digital economy is at a tipping point. This practical book defines digital ecosystems, discusses digital design using converging technologies of social networking, mobility, big data and cloud computing, and provides a methods for linking digital technologies together to meet the challenges of building a digital enterprise in the new economy.

Project Birdseye Aerial Photograph Collection: Digital and Analog Materials

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — This collection consists of both analog and digital aerial photographs from Arctic areas in and around Baffin Bay, the Labrador Sea, the Arctic Ocean, the Beaufort...

Digitally controlled analog proportional-integral-derivative (PID) controller for high-speed scanning probe microscopy

Science.gov (United States)

Dukic, Maja; Todorov, Vencislav; Andany, Santiago; Nievergelt, Adrian P.; Yang, Chen; Hosseini, Nahid; Fantner, Georg E.

2017-12-01

Nearly all scanning probe microscopes (SPMs) contain a feedback controller, which is used to move the scanner in the direction of the z-axis in order to maintain a constant setpoint based on the tip-sample interaction. The most frequently used feedback controller in SPMs is the proportional-integral (PI) controller. The bandwidth of the PI controller presents one of the speed limiting factors in high-speed SPMs, where higher bandwidths enable faster scanning speeds and higher imaging resolution. Most SPM systems use digital signal processor-based PI feedback controllers, which require analog-to-digital and digital-to-analog converters. These converters introduce additional feedback delays which limit the achievable imaging speed and resolution. In this paper, we present a digitally controlled analog proportional-integral-derivative (PID) controller. The controller implementation allows tunability of the PID gains over a large amplification and frequency range, while also providing precise control of the system and reproducibility of the gain parameters. By using the analog PID controller, we were able to perform successful atomic force microscopy imaging of a standard silicon calibration grating at line rates up to several kHz.

Design rules for superconducting analog-digital transducers

International Nuclear Information System (INIS)

Haddad, Taghrid

2015-01-01

This Thesis is a contribution for dimensioning aspects of circuits designs in superconductor electronics. Mainly superconductor comparators inclusive Josephson comparators as well as QOJS-Comparators are investigated. Both types were investigated in terms of speed and sensitivity. The influence of the thermal noise on the decision process of the comparators represent in so called gray zone, which is analysed in this thesis. Thereby, different relations between design parameters were derived. A circuit model of the Josephson comparator was verified by experiments. Concepts of superconductor analog-to-digital converters, which are based on above called comparators, were investigated in detail. From the comparator design rules, new rules for AD-converters were derived. Because of the reduced switching energy, the signal to noise ratio (SNR) of the circuits is affected and therefore the reliability of the decision-process is affected. For special applications with very demanding requirements in terms of the speed and accuracy superconductor analog-to-digital converters offer an excellent performance. This thesis provides relations between different design paramenters and shows resulting trade-offs, This method is transparent and easy to transfer to other circuit topologies. As a main result, a highly predictive tool for dimensioning of superconducting ADC's is proved.

Effects of Analog-to-Digital Converter Nonlinearities on Radar Range-Doppler Maps

Energy Technology Data Exchange (ETDEWEB)

Doerry, Armin Walter [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Dubbert, Dale F. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Tise, Bertice L. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

2014-07-01

Radar operation, particularly Ground Moving Target Indicator (GMTI) radar modes, are very sensitive to anomalous effects of system nonlinearities. These throw off harmonic spurs that are sometimes detected as false alarms. One significant source of nonlinear behavior is the Analog to Digital Converter (ADC). One measure of its undesired nonlinearity is its Integral Nonlinearity (INL) specification. We examine in this report the relationship of INL to GMTI performance.

High-speed multiple-channel analog to digital data-acquisition module for microprocessor systems

International Nuclear Information System (INIS)

Ethridge, C.D.

1977-01-01

Intelligent data acquisition and instrumentation systems established by the incorporation of microprocessor technology require high-speed analog to digital conversion of multiple-channel input signals. Sophisticated data systems or subsystems are enabled by the microprocessor software flexibility to establish adaptive input data procedures. These adaptive procedures are enhanced by versatile interface circuitry which is software controlled

Resonant Tunneling Analog-To-Digital Converter

Science.gov (United States)

Broekaert, T. P. E.; Seabaugh, A. C.; Hellums, J.; Taddiken, A.; Tang, H.; Teng, J.; vanderWagt, J. P. A.

1995-01-01

As sampling rates continue to increase, current analog-to-digital converter (ADC) device technologies will soon reach a practical resolution limit. This limit will most profoundly effect satellite and military systems used, for example, for electronic countermeasures, electronic and signal intelligence, and phased array radar. New device and circuit concepts will be essential for continued progress. We describe a novel, folded architecture ADC which could enable a technological discontinuity in ADC performance. The converter technology is based on the integration of multiple resonant tunneling diodes (RTD) and hetero-junction transistors on an indium phosphide substrate. The RTD consists of a layered semiconductor hetero-structure AlAs/InGaAs/AlAs(2/4/2 nm) clad on either side by heavily doped InGaAs contact layers. Compact quantizers based around the RTD offer a reduction in the number of components and a reduction in the input capacitance Because the component count and capacitance scale with the number of bits N, rather than by 2 (exp n) as in the flash ADC, speed can be significantly increased, A 4-bit 2-GSps quantizer circuit is under development to evaluate the performance potential. Circuit designs for ADC conversion with a resolution of 6-bits at 25GSps may be enabled by the resonant tunneling approach.

Digital optical feeder links system for broadband geostationary satellite

Science.gov (United States)

Poulenard, Sylvain; Mège, Alexandre; Fuchs, Christian; Perlot, Nicolas; Riedi, Jerome; Perdigues, Josep

2017-02-01

An optical link based on a multiplex of wavelengths at 1.55μm is foreseen to be a valuable solution for the feeder link of the next generation of high-throughput geostationary satellite. The main satellite operator specifications for such link are an availability of 99.9% over the year, a capacity around 500Gbit/s and to be bent-pipe. Optical ground station networks connected to Terabit/s terrestrial fibers are proposed. The availability of the optical feeder link is simulated over 5 years based on a state-of-the-art cloud mask data bank and an atmospheric turbulence strength model. Yearly and seasonal optical feeder link availabilities are derived and discussed. On-ground and on-board terminals are designed to be compliant with 10Gbit/s per optical channel data rate taking into account adaptive optic systems to mitigate the impact of atmospheric turbulences on single-mode optical fiber receivers. The forward and return transmission chains, concept and implementation, are described. These are based on a digital transparent on-off keying optical link with digitalization of the DVB-S2 and DVB-RCS signals prior to the transmission, and a forward error correcting code. In addition, the satellite architecture is described taking into account optical and radiofrequency payloads as well as their interfaces.

Digital versus analog complete-arch impressions for single-unit premolar implant crowns: Operating time and patient preference.

Science.gov (United States)

Schepke, Ulf; Meijer, Henny J A; Kerdijk, Wouter; Cune, Marco S

2015-09-01

Digital impression-making techniques are supposedly more patient friendly and less time-consuming than analog techniques, but evidence is lacking to substantiate this assumption. The purpose of this in vivo within-subject comparison study was to examine patient perception and time consumption for 2 complete-arch impression-making methods: a digital and an analog technique. Fifty participants with a single missing premolar were included. Treatment consisted of implant therapy. Three months after implant placement, complete-arch digital (Cerec Omnicam; Sirona) and analog impressions (semi-individual tray, Impregum; 3M ESPE) were made, and the participant's opinion was evaluated with a standard questionnaire addressing several domains (inconvenience, shortness of breath, fear of repeating the impression, and feelings of helplessness during the procedure) with the visual analog scale. All participants were asked which procedure they preferred. Operating time was measured with a stopwatch. The differences between impressions made for maxillary and mandibular implants were also compared. The data were analyzed with paired and independent sample t tests, and effect sizes were calculated. Statistically significant differences were found in favor of the digital procedure regarding all subjective domains (P<.001), with medium to large effect sizes. Of all the participants, over 80% preferred the digital procedure to the analog procedure. The mean duration of digital impression making was 6 minutes and 39 seconds (SD=1:51) versus 12 minutes and 13 seconds (SD=1:24) for the analog impression (P<.001, effect size=2.7). Digital impression making for the restoration of a single implant crown takes less time than analog impression making. Furthermore, participants preferred the digital scan and reported less inconvenience, less shortness of breath, less fear of repeating the impression, and fewer feelings of helplessness during the procedure. Copyright © 2015 Editorial Council

8-bit serial-parallel analog-to-digital converter for fast transient recorder

International Nuclear Information System (INIS)

Kulka, Z.; Nadachowski, M.; Zimek, Z.

1990-08-01

An 8-bit serial-parallel analog-to-digital converter with a sampling frequency 5 MHz is described. The most important circuits of the device are described and parameters are given. The converter is a central part of a transient recorder type TR-1 designed for recording pulse waveforms in measurements of the kinetics of chemical reactions which are radiation-induced using an electron linear accelerator. 9 refs., 9 figs. (author)

RANKING RELATIONS USING ANALOGIES IN BIOLOGICAL AND INFORMATION NETWORKS1

Science.gov (United States)

Silva, Ricardo; Heller, Katherine; Ghahramani, Zoubin; Airoldi, Edoardo M.

2013-01-01

Analogical reasoning depends fundamentally on the ability to learn and generalize about relations between objects. We develop an approach to relational learning which, given a set of pairs of objects S = {A(1) : B(1), A(2) : B(2), …, A(N) : B(N)}, measures how well other pairs A : B fit in with the set S. Our work addresses the following question: is the relation between objects A and B analogous to those relations found in S? Such questions are particularly relevant in information retrieval, where an investigator might want to search for analogous pairs of objects that match the query set of interest. There are many ways in which objects can be related, making the task of measuring analogies very challenging. Our approach combines a similarity measure on function spaces with Bayesian analysis to produce a ranking. It requires data containing features of the objects of interest and a link matrix specifying which relationships exist; no further attributes of such relationships are necessary. We illustrate the potential of our method on text analysis and information networks. An application on discovering functional interactions between pairs of proteins is discussed in detail, where we show that our approach can work in practice even if a small set of protein pairs is provided. PMID:24587838

Method and apparatus for analog signal conditioner for high speed, digital x-ray spectrometer

International Nuclear Information System (INIS)

Warburton, W.K.; Hubbard, B.

1999-01-01

A signal processing system which accepts input from an x-ray detector-preamplifier and produces a signal of reduced dynamic range for subsequent analog-to-digital conversion is disclosed. The system conditions the input signal to reduce the number of bits required in the analog-to-digital converter by removing that part of the input signal which varies only slowly in time and retaining the amplitude of the pulses which carry information about the x-rays absorbed by the detector. The parameters controlling the signal conditioner's operation can be readily supplied in digital form, allowing it to be integrated into a feedback loop as part of a larger digital x-ray spectroscopy system. 13 figs

Pulse shape analysis based on similarity and neural network with digital-analog fusion method

International Nuclear Information System (INIS)

Mardiyanto, M.P.; Uritani, A.; Sakai, H.; Kawarabayashi, J.; Iguchi, T.

2000-01-01

Through the measurement of 22 Na γ-rays, it has been demonstrated that the correction process was well done by fusing the similarity values with the pulse heights measured by the analog system, where at least four improvements in the energy spectrum characteristics were recognized, i.e., the increase of the peak-to-valley ratio, the photopeak area, the photopeak sharpness without discarding any events, and the 1,275 keV γ-ray photopeak was seen. The use of a slow digitizer was the main problem for this method. However, it can be solved easily using a faster digitizer. The fusion method was also applied for the beta-gamma mixed spectra separation. Mixed spectra of beta-gamma of the 137 Cs- 90 Sr mixed source could be separated well. We made a comparison between the energy spectrum of 137 Cs as a result of independent measurement with the result of the separation. After being compared, both FWHM agreed quite well. However, there was a slight difference between the two spectra on the peak-to-valley ratio. This separation method is simple and useful so that it can be applied for many other similar applications. (S.Y.)

Cross-Domain Analogies as Relating Derived Relations among Two Separate Relational Networks

Science.gov (United States)

Ruiz, Francisco J; Luciano, Carmen

2011-01-01

Contemporary behavior analytic research is making headway in analyzing analogy as the establishment of a relation of coordination among common types of trained or derived relations. Previous studies have been focused on within-domain analogy. The current study expands previous research by analyzing cross-domain analogy as relating relations among separate relational networks and by correlating participants' performance with a standard measure of analogical reasoning. In two experiments, adult participants first completed general intelligence and analogical reasoning tests. Subsequently, they were exposed to a computerized conditional discrimination training procedure designed to create two relational networks, each consisting of two 3-member equivalence classes. The critical test was a two-part analogical test in which participants had to relate combinatorial relations of coordination and distinction between the two relational networks. In Experiment 1, combinatorial relations for each network were individually tested prior to analogical testing, but in Experiment 2 they were not. Across both experiments, 65% of participants passed the analogical test on the first attempt. Moreover, results from the training procedure were strongly correlated with the standard measure of analogical reasoning. PMID:21547072

Programmable electronic system for analog and digital gamma cameras modernization

International Nuclear Information System (INIS)

Osorio Deliz, J. F.; Diaz Garcia, A.; Arista Omeu, E. J.

2013-01-01

At present the use of analog and digital gamma cameras is continuously increasing in developing countries. Many of them still largely rely in old hardware electronics, which in many cases limits their use in actual nuclear medicine diagnostic studies. For this reason worldwide there are different medical equipment manufacturing companies engaged into partial or total Gamma Cameras modernization. Nevertheless in several occasions acquisition prices are not affordable for developing countries. This work describes the basic features of a programmable electronic system that allows improving acquisitions functions and processing of analog and digital gamma cameras. This system is based on an electronic board for the acquisition and digitization of nuclear pulses which have been generated by gamma camera detector. It comprises a hardware interface with PC and the associated software to fully signal processing. Signal shaping and image processing are included. The extensive use of reference tables in the processing and signal imaging software allowed the optimization of the processing speed. Time design and system cost were also decreased. (Author)

A digital-type fluxgate magnetometer using a sigma-delta digital-to-analog converter for a sounding rocket experiment

International Nuclear Information System (INIS)

Iguchi, Kyosuke; Matsuoka, Ayako

2014-01-01

One of the design challenges for future magnetospheric satellite missions is optimizing the mass, size, and power consumption of the instruments to meet the mission requirements. We have developed a digital-type fluxgate (DFG) magnetometer that is anticipated to have significantly less mass and volume than the conventional analog-type. Hitherto, the lack of a space-grade digital-to-analog converter (DAC) with good accuracy has prevented the development of a high-performance DFG. To solve this problem, we developed a high-resolution DAC using parts whose performance was equivalent to existing space-grade parts. The developed DAC consists of a 1-bit second-order sigma-delta modulator and a fourth-order analog low-pass filter. We tested the performance of the DAC experimentally and found that it had better than 17-bits resolution in 80% of the measurement range, and the linearity error was 2 −13.3  of the measurement range. We built a DFG flight model (in which this DAC was embedded) for a sounding rocket experiment as an interim step in the development of a future satellite mission. The noise of this DFG was 0.79 nT rms  at 0.1–10 Hz, which corresponds to a roughly 17-bit resolution. The results show that the sigma-delta DAC and the DFG had a performance that is consistent with our optimized design, and the noise was as expected from the noise simulation. Finally, we have confirmed that the DFG worked successfully during the flight of the sounding rocket. (paper)

A digital-type fluxgate magnetometer using a sigma-delta digital-to-analog converter for a sounding rocket experiment

Science.gov (United States)

Iguchi, Kyosuke; Matsuoka, Ayako

2014-07-01

One of the design challenges for future magnetospheric satellite missions is optimizing the mass, size, and power consumption of the instruments to meet the mission requirements. We have developed a digital-type fluxgate (DFG) magnetometer that is anticipated to have significantly less mass and volume than the conventional analog-type. Hitherto, the lack of a space-grade digital-to-analog converter (DAC) with good accuracy has prevented the development of a high-performance DFG. To solve this problem, we developed a high-resolution DAC using parts whose performance was equivalent to existing space-grade parts. The developed DAC consists of a 1-bit second-order sigma-delta modulator and a fourth-order analog low-pass filter. We tested the performance of the DAC experimentally and found that it had better than 17-bits resolution in 80% of the measurement range, and the linearity error was 2-13.3 of the measurement range. We built a DFG flight model (in which this DAC was embedded) for a sounding rocket experiment as an interim step in the development of a future satellite mission. The noise of this DFG was 0.79 nTrms at 0.1-10 Hz, which corresponds to a roughly 17-bit resolution. The results show that the sigma-delta DAC and the DFG had a performance that is consistent with our optimized design, and the noise was as expected from the noise simulation. Finally, we have confirmed that the DFG worked successfully during the flight of the sounding rocket.

Energy Efficient Digital Networks

Energy Technology Data Exchange (ETDEWEB)

Lanzisera, Steven [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Brown, Richard [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

2013-01-01

Digital networks are the foundation of the information services, and play an expanding and indispensable role in our lives, via the Internet, email, mobile phones, etc. However, these networks consume energy, both through the direct energy use of the network interfaces and equipment that comprise the network, and in the effect they have on the operating patterns of devices connected to the network. The purpose of this research was to investigate a variety of technology and policy issues related to the energy use caused by digital networks, and to further develop several energy-efficiency technologies targeted at networks.

High-speed photonically assisted analog-to-digital conversion using a continuous wave multiwavelength source and phase modulation.

Science.gov (United States)

Bortnik, Bartosz J; Fetterman, Harold R

2008-10-01

A more simple photonically assisted analog-to-digital conversion system utilizing a cw multiwavelength source and phase modulation instead of a mode-locked laser is presented. The output of the cw multiwavelength source is launched into a dispersive device (such as a single-mode fiber). This fiber creates a pulse train, where the central wavelength of each pulse corresponds to a spectral line of the optical source. The pulses can then be either dispersed again to perform discrete wavelength time stretching or demultiplexed for continuous time analog-to-digital conversion. We experimentally demonstrate the operation of both time stretched and interleaved systems at 38 GHz. The potential of integrating this type of system on a monolithic chip is discussed.

An Experimentation Platform for On-Chip Integration of Analog Neural Networks: A Pathway to Trusted and Robust Analog/RF ICs.

Science.gov (United States)

Maliuk, Dzmitry; Makris, Yiorgos

2015-08-01

We discuss the design of an experimentation platform intended for prototyping low-cost analog neural networks for on-chip integration with analog/RF circuits. The objective of such integration is to support various tasks, such as self-test, self-tuning, and trust/aging monitoring, which require classification of analog measurements obtained from on-chip sensors. Particular emphasis is given to cost-efficient implementation reflected in: 1) low energy and area budgets of circuits dedicated to neural networks; 2) robust learning in presence of analog inaccuracies; and 3) long-term retention of learned functionality. Our chip consists of a reconfigurable array of synapses and neurons operating below threshold and featuring sub-μW power consumption. The synapse circuits employ dual-mode weight storage: 1) a dynamic mode, for fast bidirectional weight updates during training and 2) a nonvolatile mode, for permanent storage of learned functionality. We discuss a robust learning strategy, and we evaluate the system performance on several benchmark problems, such as the XOR2-6 and two-spirals classification tasks.

The Security Research of Digital Library Network

Science.gov (United States)

Zhang, Xin; Song, Ding-Li; Yan, Shu

Digital library is a self-development needs for the modern library to meet the development requirements of the times, changing the way services and so on. digital library from the hardware, technology, management and other aspects to objective analysis of the factors of threats to digital library network security. We should face up the problems of digital library network security: digital library network hardware are "not hard", the technology of digital library is relatively lag, digital library management system is imperfect and other problems; the government should take active measures to ensure that the library funding, to enhance the level of network hardware, to upgrade LAN and prevention technology, to improve network control technology, network monitoring technology; to strengthen safety management concepts, to prefect the safety management system; and to improve the level of security management modernization for digital library.

Analog Fiber Optic Link with DC-100 MHz Bandwidth

National Research Council Canada - National Science Library

Sullivan, C. A; Girardi, P. G; Lohrmann, Dieter R

2008-01-01

An analog fiber optic link covering the frequency range from DC to 100 MHz was designed, constructed, and tested, in order to connect a 10 kA pulse current probe to oscilloscopes for oscillographing...

Assessment of wireless Sensor Networks for Digital Instrument and Control System at Nuclear Facilities

International Nuclear Information System (INIS)

Gomma, R.I.M.

2015-01-01

Instrumentation and Control (I and C) systems play a crucial role in the operation of Nuclear Power Plants (NPPs). The most important task of I and C systems is to ensure safety, availability, and performance of the plant. The advanced generation of NPP design is expected to have the higher degree of automation; consequently, it requires new solutions in both sensing technologies and digital control. In general, the world’s nuclear power fleet is relying on the progress of digital electronics and information technology, to create incentives for integrated replacement of traditional analog electronics with novel digital I and C systems that rely on wireless technology. Moreover, as the domain of Wireless Sensor Networks (WSN) increases its market share in many industrial, health, and critical applications, it has matured significantly. As a result, the barriers to the nuclear industry entry will surely continue to decrease further. Nowadays, several WSN deployments for on-line monitoring of the nuclear environment have been recently addressed by incremental and experimental networks. Furthermore, upon tightening new regulations, the demand for using smart wireless sensing for safety, and surveillance applications of nuclear installations are growing rapidly. The first part of this thesis describes the design of a practical small-scale WSN that allows smart real-time monitoring of radiation levels at nuclear facilities. A wireless system combined with a radiation sensor and associated peripherals been developed and implemented on ZigBee technology using the TI CC2530 chip. The radiation sensor uses a Geiger Muller Tube (GMT) as a reliable detector for the radioactive particulates in the gaseous effluent vented from nuclear facilities. The WSN allows the operators to record and control the radiation levels emitted into the environment, and it is supported by a warning system, for the early detection of radiation release. We evaluated the performance of the radiation

Sensor Interfaces for Private Home Automation: From Analog to Digital, Wireless and Autonomous

Directory of Open Access Journals (Sweden)

Erich Leder

2007-08-01

Full Text Available In this paper a flexible and reliable system for smart home automation is presented. It is based on standardized hardware and open source communication protocols. Firstly, a special sensor interface has been developed, which allows the measurement of (slow analog signals to be determined by inexpensive digital PLC input terminals. Right now, up to eleven different modules have been implemented and the system is being tested in several configurations. In a second step, the communication is digitized. With the digitalization of the sensor modules, based on the implementation of a PIC Microcontroller, more intelligence is provided to the module, which increases the power and flexibility of the whole system. Thirdly, a wireless sensor-system consisting of a base station and of a mobile measuring unit is developed. The autonomous mobile unit is realized by using solar powering, gold cap energy storage, low-power circuits and a radio communication interface.

The Transition from Analog to Digital Mammography: Overall Considerations

OpenAIRE

A. Sardo

2007-01-01

In the last decades a continuous growth of the infor-matics process around the world has been observed: paper documents, data, images…, converted into a “digital format” allow an easier and safer manage-ment, making possible its compatibility and access to internet networking. This migration confirms the huge technology progresses made especially in the image capture ways: from photography to graphic arts, from movie to healthcare imaging, where the end user/radiologist requires, at least, a ...

Fast collimated neutron flux measurement using stilbene scintillator and flashy analog-to-digital converter in JT-60U

International Nuclear Information System (INIS)

Ishikawa, M.; Itoga, T.; Okuji, T.; Nakhostin, M.; Shinohara, K.; Hayashi, T.; Sukegawa, A.; Baba, M.; Nishitani, T.

2006-01-01

A line-integrated neutron emission profile is routinely measured using the radial neutron collimator system in JT-60U tokamak. Stilbene neuron detectors (SNDs), which combine a stilbene organic crystal scintillation detector (SD) with an analog neutron-gamma pulse shape discrimination (PSD) circuit, have been used to measure collimated neutron flux. Although the SND has many advantages as a neutron detector, the maximum count rate is limited up to ∼1x10 5 counts/s due to the analog PSD circuit. To overcome this issue, a digital signal processing system (DSPS) using a flash analog-to-digital converter (Acqiris DC252, 8 GHz, 10 bits) has been developed at Cyclotron and Radioisotope Center in Tohoku University. In this system anode signals from photomultiplier of the SD are directory stored and digitized. Then, the PSD between neutrons and gamma rays is performed using software. The DSPS has been installed in the vertical neutron collimator system in JT-60U and applied to deuterium experiments. It is confirmed that the PSD is sufficiently performed and collimated neutron flux is successfully measured with count rate up to ∼5x10 5 counts/s without the effect of pileup of detected pulses. The performance of the DSPS as a neutron detector, which supersedes the SND, is demonstrated

Digital to Analog Converter Description

NARCIS (Netherlands)

van Tuijl, Adrianus Johannes Maria

2002-01-01

A circuit for analogue to digital or digital to analogue conversion comprising at least 2n matched current sources (40-1, 40-2, 40-n), where n is the resolution required of the conversion. Preferably more than 2n current sources (40-1, 40-2, 40-n) are used. The order in which the sources (40-1,

Digital Native and Digital Immigrant Use of Scholarly Network for Doctoral Learners

Directory of Open Access Journals (Sweden)

Ronald Berman

2014-01-01

Full Text Available The Doctoral Community Network (DC is a learner driven, scholarly community designed to help online doctoral learners successfully complete their dissertation and program of study. While digital natives grew up in an environment immersed in technology, digital immigrants adapted to this environment through their ability to learn and adjust to new technologies. With several thousand Doctoral Community Network users, it was not known to what extent digital immigrants had embraced the technology. A study of 988 users determined that digital immigrants used the Doctoral Community Network more often and for a larger variety of purposes than digital natives did. Specifically, digital immigrants log-on more frequently, view leadership content at higher rates, read more blogs, use more doctoral community network research resources, and send and receive more peer messages than digital natives do. This research supports existing literature that found that digital immigrants possess higher levels of social reliance than digital natives while contradicting other literature that found that digital natives tend to use the internet for social networking and blog diaries at higher rates.

Bulgarian National Digital Seismological Network

Science.gov (United States)

Dimitrova, L.; Solakov, D.; Nikolova, S.; Stoyanov, S.; Simeonova, S.; Zimakov, L. G.; Khaikin, L.

2011-12-01

The Bulgarian National Digital Seismological Network (BNDSN) consists of a National Data Center (NDC), 13 stations equipped with RefTek High Resolution Broadband Seismic Recorders - model DAS 130-01/3, 1 station equipped with Quanterra 680 and broadband sensors and accelerometers. Real-time data transfer from seismic stations to NDC is realized via Virtual Private Network of the Bulgarian Telecommunication Company. The communication interruptions don't cause any data loss at the NDC. The data are backed up in the field station recorder's 4Mb RAM memory and are retransmitted to the NDC immediately after the communication link is re-established. The recorders are equipped with 2 compact flash disks able to save more than 1 month long data. The data from the flash disks can be downloaded remotely using FTP. The data acquisition and processing hardware redundancy at the NDC is achieved by two clustered SUN servers and two Blade Workstations. To secure the acquisition, processing and data storage processes a three layer local network is designed at the NDC. Real-time data acquisition is performed using REFTEK's full duplex error-correction protocol RTPD. Data from the Quanterra recorder and foreign stations are fed into RTPD in real-time via SeisComP/SeedLink protocol. Using SeisComP/SeedLink software the NDC transfers real-time data to INGV-Roma, NEIC-USA, ORFEUS Data Center. Regional real-time data exchange with Romania, Macedonia, Serbia and Greece is established at the NDC also. Data processing is performed by the Seismic Network Data Processor (SNDP) software package running on the both Servers. SNDP includes subsystems: Real-time subsystem (RTS_SNDP) - for signal detection; evaluation of the signal parameters; phase identification and association; source estimation; Seismic analysis subsystem (SAS_SNDP) - for interactive data processing; Early warning subsystem (EWS_SNDP) - based on the first arrived P-phases. The signal detection process is performed by

Effectiveness of link prediction for face-to-face behavioral networks.

Science.gov (United States)

Tsugawa, Sho; Ohsaki, Hiroyuki

2013-01-01

Research on link prediction for social networks has been actively pursued. In link prediction for a given social network obtained from time-windowed observation, new link formation in the network is predicted from the topology of the obtained network. In contrast, recent advances in sensing technology have made it possible to obtain face-to-face behavioral networks, which are social networks representing face-to-face interactions among people. However, the effectiveness of link prediction techniques for face-to-face behavioral networks has not yet been explored in depth. To clarify this point, here we investigate the accuracy of conventional link prediction techniques for networks obtained from the history of face-to-face interactions among participants at an academic conference. Our findings were (1) that conventional link prediction techniques predict new link formation with a precision of 0.30-0.45 and a recall of 0.10-0.20, (2) that prolonged observation of social networks often degrades the prediction accuracy, (3) that the proposed decaying weight method leads to higher prediction accuracy than can be achieved by observing all records of communication and simply using them unmodified, and (4) that the prediction accuracy for face-to-face behavioral networks is relatively high compared to that for non-social networks, but not as high as for other types of social networks.

A precise time synchronization method for 5G based on radio-over-fiber network with SDN controller

Science.gov (United States)

He, Linkuan; Wei, Baoguo; Yang, Hui; Yu, Ao; Wang, Zhengyong; Zhang, Jie

2018-02-01

There is an increasing demand on accurate time synchronization with the growing bandwidth of network service for 5G. In 5G network, it's necessary for base station to achieve accurate time synchronization to guarantee the quality of communication. In order to keep accuracy time for 5G network, we propose a time synchronization system for satellite ground station based on radio-over-fiber network (RoFN) with software defined optical network (SDON) controller. The advantage of this method is to improve the accuracy of time synchronization of ground station. The IEEE 1588 time synchronization protocol can solve the problems of high cost and lack of precision. However, in the process of time synchronization, distortion exists during the transmission of digital time signal. RoF uses analog optical transmission links and therefore analog transmission can be implemented among ground stations instead of digital transmission, which means distortion and bandwidth waste in the process of digital synchronization can be avoided. Additionally, the thought of SDN, software defined network, can optimize RoFN with centralized control and simplifying base station. Related simulation had been carried out to prove its superiority.

PIC microcontroller based external fast analog to digital converter to acquire wide-lined solid NMR spectra by BRUKER DRX and Avance-I spectrometers.

Science.gov (United States)

Koczor, Bálint; Rohonczy, János

2015-01-01

Concerning many former liquid or hybrid liquid/solid NMR consoles, the built in Analog-to-Digital Converters (ADCs) are incapable of digitizing the fids at sampling rates in the MHz range. Regarding both strong anisotropic interactions in the solid state and wide chemical shift dispersion nuclei in solution phase such as (195)Pt, (119)Sn, (207)Pb etc., the spectrum range of interest might be in the MHz range. As determining the informative tensor components of anisotropic NMR interactions requires nonlinear fitting over the whole spectrum including the asymptotic baseline, it is prohibited by low sampling rates of the ADCs. Wide spectrum width is also useful in solution NMR, since windowing of wide chemical shift ranges is avoidable. We built an external analog to digital converter with 10 MHz maximal sampling rate, which can work simultaneously with the built in ADC of the spectrometer. The ADC was tested on both Bruker DRX and Avance-I NMR consoles. In addition to the analog channels it only requires three external digital lines of the NMR console. The ADC sends data to PC via USB. The whole process is controlled by software written in JAVA which is implemented under TopSpin. Copyright © 2015 Elsevier Inc. All rights reserved.

Analysis of several digital network technologies for hard real-time communications in nuclear plant

International Nuclear Information System (INIS)

Song, Ki Sang; No, Hee Chun

1999-01-01

Applying digital network technology for advanced nuclear plant requires deterministic communication for tight safety requirements, timely and reliable data delivery for operation critical and mission-critical characteristics of nuclear plant. Communication protocols, such as IEEE 802/4 Tiken Bus, IEEE 802/5 Token Ring, FDDI, and ARCnet, which have deterministic communication capability are partially applied to several nuclear power plants. Although digital communication technologies have many advantages, it is necessary to consider the noise immunity form electromagnetic interference (EMI), electrical interference, impulse noise, and heat noise before selecting specific digital network technology for nuclear plant. In this paper, we consider the token frame loss and data frame loss rate due to the link error event, frame size, and link data rate in different protocols, and evaluate the possibility of failure to meet the hard real-time requirement in nuclear plant. (author). 11 refs., 3 figs., 4 tabs

Network device interface for digitally interfacing data channels to a controller via a network

Science.gov (United States)

Ellerbrock, Philip J. (Inventor); Grant, Robert L. (Inventor); Konz, Daniel W. (Inventor); Winkelmann, Joseph P. (Inventor)

2009-01-01

A communications system and method are provided for digitally connecting a plurality of data channels, such as sensors, actuators, and subsystems, to a controller using a network bus. The network device interface interprets commands and data received from the controller and polls the data channels in accordance with these commands. Specifically, the network device interface receives digital commands and data from the controller, and based on these commands and data, communicates with the data channels to either retrieve data in the case of a sensor or send data to activate an actuator. Data retrieved from the sensor is converted into digital signals and transmitted to the controller. Network device interfaces associated with different data channels can coordinate communications with the other interfaces based on either a transition in a command message sent by the bus controller or a synchronous clock signal.

A bilateral frontoparietal network underlies visuospatial analogical reasoning.

Science.gov (United States)

Watson, Christine E; Chatterjee, Anjan

2012-02-01

Our ability to reason by analogy facilitates problem solving and allows us to communicate ideas efficiently. In this study, we examined the neural correlates of analogical reasoning and, more specifically, the contribution of rostrolateral prefrontal cortex (RLPFC) to reasoning. This area of the brain has been hypothesized to integrate relational information, as in analogy, or the outcomes of subgoals, as in multi-tasking and complex problem solving. Using fMRI, we compared visuospatial analogical reasoning to a control task that was as complex and difficult as the analogies and required the coordination of subgoals but not the integration of relations. We found that analogical reasoning more strongly activated bilateral RLPFC, suggesting that anterior prefrontal cortex is preferentially recruited by the integration of relational knowledge. Consistent with the need for inhibition during analogy, bilateral, and particularly right, inferior frontal gyri were also more active during analogy. Finally, greater activity in bilateral inferior parietal cortex during the analogy task is consistent with recent evidence for the neural basis of spatial relation knowledge. Together, these findings indicate that a network of frontoparietal areas underlies analogical reasoning; we also suggest that hemispheric differences may emerge depending on the visuospatial or verbal/semantic nature of the analogies. Copyright © 2011 Elsevier Inc. All rights reserved.

A novel analog/digital reconfigurable automatic gain control with a novel DC offset cancellation circuit

Energy Technology Data Exchange (ETDEWEB)

He Xiaofeng; Ye Tianchun [Institute of Microelectronics, Chinese Academy of Science, Beijing 100029 (China); Mo Taishan; Ma Chengyan, E-mail: hexiaofeng@casic.ac.cn [Hangzhou Zhongke Microelectronics Co, Ltd, Hangzhou 310053 (China)

2011-02-15

An analog/digital reconfigurable automatic gain control (AGC) circuit with a novel DC offset cancellation circuit for a direct-conversion receiver is presented. The AGC is analog/digital reconfigurable in order to be compatible with different baseband chips. What's more, a novel DC offset cancellation (DCOC) circuit with an HPCF (high pass cutoff frequency) less than 10 kHz is proposed. The AGC is fabricated by a 0.18 {mu}m CMOS process. Under analog control mode, the AGC achieves a 70 dB dynamic range with a 3 dB-bandwidth larger than 60 MHz. Under digital control mode, through a 5-bit digital control word, the AGC shows a 64 dB gain control range by 2 dB each step with a gain error of less than 0.3 dB. The DC offset cancellation circuits can suppress the output DC offset voltage to be less than 1.5 mV, while the offset voltage of 40 mV is introduced into the input. The overall power consumption is less than 3.5 mA, and the die area is 800 x 300 {mu}m{sup 2}. (semiconductor integrated circuits)

Analog-to-digital conversion to accommodate the dynamics of live music in hearing instruments.

Science.gov (United States)

Hockley, Neil S; Bahlmann, Frauke; Fulton, Bernadette

2012-09-01

Hearing instrument design focuses on the amplification of speech to reduce the negative effects of hearing loss. Many amateur and professional musicians, along with music enthusiasts, also require their hearing instruments to perform well when listening to the frequent, high amplitude peaks of live music. One limitation, in most current digital hearing instruments with 16-bit analog-to-digital (A/D) converters, is that the compressor before the A/D conversion is limited to 95 dB (SPL) or less at the input. This is more than adequate for the dynamic range of speech; however, this does not accommodate the amplitude peaks present in live music. The hearing instrument input compression system can be adjusted to accommodate for the amplitudes present in music that would otherwise be compressed before the A/D converter in the hearing instrument. The methodology behind this technological approach will be presented along with measurements to demonstrate its effectiveness.

Analisis Migrasi Radio Trunking Analog ke Radio Trunking Digital di Indonesia

Directory of Open Access Journals (Sweden)

Riza Azmi

2013-09-01

Full Text Available Dalam Tabel Alokasi Spektrum Frekuensi di Indonesia pada catatan kaki INS9 dan INS13 disebutkan bahwa alokasi pada pita-pita frekuensi yang digunakan untuk teknologi trunking direncanakan dimigrasi ke sistem komunikasi trunking digital pada waktu yang akan ditentukan oleh pemerintah. Terkait dengan hal itu, studi ini bertujuan untuk mengkaji bagaimana kelayakan migrasi dari sistem trunking analog ke sistem trunking digital dan hal-hal yang terkait dengannya. Dengan menggunakan analisis biaya dan manfaat (Cost-Benefit Analysis studi ini melihat bahwa migrasi hanya dapat dilakukan jika umur masing-masing lisensi dari operator telah berakhir, atau dengan kata lain pemerintah dapat mendorong transisi ke digital dengan menerbitkan lisensi baru yaitu lisensi trunking digital.

Telling time from analog and digital clocks: A multiple-route account

NARCIS (Netherlands)

Korvorst, M.H.W.; Roelofs, A.P.A.; Levelt, W.J.M.

2007-01-01

Does the naming of clocks always require conceptual preparation? To examine this question, speakers were presented with analog and digital clocks that had to be named in Dutch using either a relative (e.g., "quarter to four") or an absolute (e.g., "three forty-five") clock time expression format.

To trade or not to trade: Link prediction in the virtual water network

Science.gov (United States)

Tuninetti, Marta; Tamea, Stefania; Laio, Francesco; Ridolfi, Luca

2017-12-01

In the international trade network, links express the (temporary) presence of a commercial exchange of goods between any two countries. Given the dynamical behaviour of the trade network, where links are created and dismissed every year, predicting the link activation/deactivation is an open research question. Through the international trade network of agricultural goods, water resources are 'virtually' transferred from the country of production to the country of consumption. We propose a novel methodology for link prediction applied to the network of virtual water trade. Starting from the assumption of having links between any two countries, we estimate the associated virtual water flows by means of a gravity-law model using country and link characteristics as drivers. We consider the links with estimated flows higher than 1000 m3/year as active links, while the others as non-active links. Flows traded along estimated active links are then re-estimated using a similar but differently-calibrated gravity-law model. We were able to correctly model 84% of the existing links and 93% of the non-existing links in year 2011. It is worth to note that the predicted active links carry 99% of the global virtual water flow; hence, missed links are mainly those where a minimum volume of virtual water is exchanged. Results indicate that, over the period from 1986 to 2011, population, geographical distances between countries, and agricultural efficiency (through fertilizers use) are the major factors driving the link activation and deactivation. As opposed to other (network-based) models for link prediction, the proposed method is able to reconstruct the network architecture without any prior knowledge of the network topology, using only the nodes and links attributes; it thus represents a general method that can be applied to other networks such as food or value trade networks.

Opportunistic beam training with hybrid analog/digital codebooks for mmWave systems

KAUST Repository

Eltayeb, Mohammed E.

2016-02-25

© 2015 IEEE. Millimeter wave (mmWave) communication is one solution to provide more spectrum than available at lower carrier frequencies. To provide sufficient link budget, mmWave systems will use beamforming with large antenna arrays at both the transmitter and receiver. Training these large arrays using conventional approaches taken at lower carrier frequencies, however, results in high overhead. In this paper, we propose a beam training algorithm that efficiently designs the beamforming vectors with low training overhead. Exploiting mmWave channel reciprocity, the proposed algorithm relaxes the need for an explicit feedback channel, and opportunistically terminates the training process when a desired quality of service is achieved. To construct the training beamforming vectors, a new multi-resolution codebook is developed for hybrid analog/digital architectures. Simulation results show that the proposed algorithm achieves a comparable rate to that obtained by exhaustive search solutions while requiring lower training overhead when compared to prior work.

Opportunistic beam training with hybrid analog/digital codebooks for mmWave systems

KAUST Repository

Eltayeb, Mohammed E.; Alkhateeb, Ahmed; Heath, Robert W.; Al-Naffouri, Tareq Y.

2016-01-01

© 2015 IEEE. Millimeter wave (mmWave) communication is one solution to provide more spectrum than available at lower carrier frequencies. To provide sufficient link budget, mmWave systems will use beamforming with large antenna arrays at both the transmitter and receiver. Training these large arrays using conventional approaches taken at lower carrier frequencies, however, results in high overhead. In this paper, we propose a beam training algorithm that efficiently designs the beamforming vectors with low training overhead. Exploiting mmWave channel reciprocity, the proposed algorithm relaxes the need for an explicit feedback channel, and opportunistically terminates the training process when a desired quality of service is achieved. To construct the training beamforming vectors, a new multi-resolution codebook is developed for hybrid analog/digital architectures. Simulation results show that the proposed algorithm achieves a comparable rate to that obtained by exhaustive search solutions while requiring lower training overhead when compared to prior work.

A Calibration Method for Nonlinear Mismatches in M-Channel Time-Interleaved Analog-to-Digital Converters Based on Hadamard Sequences

Directory of Open Access Journals (Sweden)

Husheng Liu

2016-11-01

Full Text Available The time-interleaved analog-to-digital converter (TIADC is an architecture used to achieve a high sampling rate and high dynamic performance. However, estimation and compensation methods are required to maintain the dynamic performance of the constituent analog-to-digital converters (ADCs due to channel mismatches. This paper proposes a blind adaptive method to calibrate the nonlinear mismatches in M-channel TIADCs (M-TIADCs. The nonlinearity-induced error signal is reconstructed by the proposed multiplier Hadamard transform (MHT structure, and the nonlinear parameters are estimated by the filtered-X least-mean square (FxLMS algorithm. The performance of cascade calibration is also analyzed. The numerical simulation results show that the proposed method consumes much less hardware resources while maintaining the calibration performance.

Proposition of a scheme for adaptive/intelligent analog-to-digital converters

International Nuclear Information System (INIS)

Vaidya, P.P.; Kataria, S.K.

2001-01-01

The paper proposes design of a new class of Analog to Digital Converters (ADC's) which we call as Intelligent ADC's with moving resolution. Unlike presently available ADC's which are designed for specific range of applications and give fixed resolution and conversion time, the intelligent ADC's described here can adjust their resolution during the process of conversion, depending upon nature of input signal to make optimum use of the hard-ware. It is possible to use an intelligent ADC to give resolution ranging from 8 bit to 16 bit and conversion time ranging from few nano sec. to few micro secs. These ADC's have significant advantages over conventional ones when used for nuclear pulse spectroscopy as well as for process control applications. (author)

Analog synthetic biology.

Science.gov (United States)

Sarpeshkar, R

2014-03-28

We analyse the pros and cons of analog versus digital computation in living cells. Our analysis is based on fundamental laws of noise in gene and protein expression, which set limits on the energy, time, space, molecular count and part-count resources needed to compute at a given level of precision. We conclude that analog computation is significantly more efficient in its use of resources than deterministic digital computation even at relatively high levels of precision in the cell. Based on this analysis, we conclude that synthetic biology must use analog, collective analog, probabilistic and hybrid analog-digital computational approaches; otherwise, even relatively simple synthetic computations in cells such as addition will exceed energy and molecular-count budgets. We present schematics for efficiently representing analog DNA-protein computation in cells. Analog electronic flow in subthreshold transistors and analog molecular flux in chemical reactions obey Boltzmann exponential laws of thermodynamics and are described by astoundingly similar logarithmic electrochemical potentials. Therefore, cytomorphic circuits can help to map circuit designs between electronic and biochemical domains. We review recent work that uses positive-feedback linearization circuits to architect wide-dynamic-range logarithmic analog computation in Escherichia coli using three transcription factors, nearly two orders of magnitude more efficient in parts than prior digital implementations.

Integrated electrofluidic circuits: pressure sensing with analog and digital operation functionalities for microfluidics.

Science.gov (United States)

Wu, Chueh-Yu; Lu, Jau-Ching; Liu, Man-Chi; Tung, Yi-Chung

2012-10-21

Microfluidic technology plays an essential role in various lab on a chip devices due to its desired advantages. An automated microfluidic system integrated with actuators and sensors can further achieve better controllability. A number of microfluidic actuation schemes have been well developed. In contrast, most of the existing sensing methods still heavily rely on optical observations and external transducers, which have drawbacks including: costly instrumentation, professional operation, tedious interfacing, and difficulties of scaling up and further signal processing. This paper reports the concept of electrofluidic circuits - electrical circuits which are constructed using ionic liquid (IL)-filled fluidic channels. The developed electrofluidic circuits can be fabricated using a well-developed multi-layer soft lithography (MSL) process with polydimethylsiloxane (PDMS) microfluidic channels. Electrofluidic circuits allow seamless integration of pressure sensors with analog and digital operation functions into microfluidic systems and provide electrical readouts for further signal processing. In the experiments, the analog operation device is constructed based on electrofluidic Wheatstone bridge circuits with electrical outputs of the addition and subtraction results of the applied pressures. The digital operation (AND, OR, and XOR) devices are constructed using the electrofluidic pressure controlled switches, and output electrical signals of digital operations of the applied pressures. The experimental results demonstrate the designed functions for analog and digital operations of applied pressures are successfully achieved using the developed electrofluidic circuits, making them promising to develop integrated microfluidic systems with capabilities of precise pressure monitoring and further feedback control for advanced lab on a chip applications.

SEM analysis of ionizing radiation effects in an analog to digital converter /AD571/

Science.gov (United States)

Gauthier, M. K.; Perret, J.; Evans, K. C.

1981-01-01

The considered investigation is concerned with the study of the total-dose degradation mechanisms in an IIL analog to digital (A/D) converter. The A/D converter is a 10 digit device having nine separate functional units on the chip which encompass several hundred transistors and circuit elements. It was the objective of the described research to find the radiation sensitive elements by a systematic search of the devices on the LSI chip. The employed technique using a scanning electron microscope to determine the functional blocks of an integrated circuit which are sensitive to ionizing radiation and then progressively zeroing in on the soft components within those blocks, proved extremely successful on the AD571. Four functional blocks were found to be sensitive to radiation, including the Voltage Reference, DAC, IIL Clock, and IIL SAR.

Optimal neural computations require analog processors

Energy Technology Data Exchange (ETDEWEB)

Beiu, V.

1998-12-31

This paper discusses some of the limitations of hardware implementations of neural networks. The authors start by presenting neural structures and their biological inspirations, while mentioning the simplifications leading to artificial neural networks. Further, the focus will be on hardware imposed constraints. They will present recent results for three different alternatives of parallel implementations of neural networks: digital circuits, threshold gate circuits, and analog circuits. The area and the delay will be related to the neurons` fan-in and to the precision of their synaptic weights. The main conclusion is that hardware-efficient solutions require analog computations, and suggests the following two alternatives: (i) cope with the limitations imposed by silicon, by speeding up the computation of the elementary silicon neurons; (2) investigate solutions which would allow the use of the third dimension (e.g. using optical interconnections).

The Conceptualization of Digitally Networked Participation

Directory of Open Access Journals (Sweden)

Yannis Theocharis

2015-10-01

Full Text Available The conceptualization and measurement of political participation has been an issue vibrantly debated for more than 50 years. The arrival of digital media came to add important parameters to the debate complicating matters further. Digital media have added inexhaustive creative and nonpolitical ways to engage in social and political life that not only often appear to form the basis of political participation but also, in a plethora of everyday contexts, seem to become embedded into what eventually evolves to become a politically meaningful act. This article argues that digitally networked participation—and its manifestations—is a form of political participation and should be conceptualized, identified, and measured as one. Relying on recent conceptual and empirical work, it shows how various common manifestations of digitally networked participation conform to minimalist, targeted, and motivational definitions of political participation. Finally, tackling common misconceptions about the value of such acts, this article argues that nonpolitical forms of digitally networked participation can occasionally be far more impactful than forms of participation commonly accepted as political. This article concludes by recommending the systematic development of measures for digitally networked participation and its formal integration in the study of political participation.

CASTOR a VLSI CMOS mixed analog-digital circuit for low noise multichannel counting applications

International Nuclear Information System (INIS)

Comes, G.; Loddo, F.; Hu, Y.; Kaplon, J.; Ly, F.; Turchetta, R.; Bonvicini, V.; Vacchi, A.

1996-01-01

In this paper we present the design and first experimental results of a VLSI mixed analog-digital 1.2 microns CMOS circuit (CASTOR) for multichannel radiation detectors applications demanding low noise amplification and counting of radiation pulses. This circuit is meant to be connected to pixel-like detectors. Imaging can be obtained by counting the number of hits in each pixel during a user-controlled exposure time. Each channel of the circuit features an analog and a digital part. In the former one, a charge preamplifier is followed by a CR-RC shaper with an output buffer and a threshold discriminator. In the digital part, a 16-bit counter is present together with some control logic. The readout of the counters is done serially on a common tri-state output. Daisy-chaining is possible. A 4-channel prototype has been built. This prototype has been optimised for use in the digital radiography Syrmep experiment at the Elettra synchrotron machine in Trieste (Italy): its main design parameters are: shaping time of about 850 ns, gain of 190 mV/fC and ENC (e - rms)=60+17 C (pF). The counting rate per channel, limited by the analog part, can be as high as about 200 kHz. Characterisation of the circuit and first tests with silicon microstrip detectors are presented. They show the circuit works according to design specification and can be used for imaging applications. (orig.)

Partnering for Discoverability: Knitting Archival Finding Aids to Digitized Material Using a Low Tech Digital Content Linking Process

Directory of Open Access Journals (Sweden)

Liz Woolcott

2016-10-01

Full Text Available As libraries continue to ramp up digitization efforts for unique archival and special collections material, the segregation of archival finding aids from their digitized counterparts presents an accumulating discoverability problem for both patrons and library staff. For Utah State University (USU Libraries, it became evident that a system was necessary to connect both new and legacy finding aids with their digitized content to improve use and discoverability. Following a cross-departmental workflow analysis involving the Special Collections, Cataloging and Metadata, and Digital Initiatives departments, a process was created for semi-automating the batch linking of item and folder level entries in EAD finding aids to the corresponding digitized material in CONTENTdm. In addition to the obvious benefit of linking content, this cross-departmental process also allowed for the implementation of persistent identifiers and the enhancement of finding aids using the more robust metadata that accompanies digitized material. This article will provide a detailed overview of the process, as well as describe how the three departments at USU have worked together to identify key stakeholders, develop the procedures, and address future developments.

Adaptive Reference Levels in a Level-Crossing Analog-to-Digital Converter

Directory of Open Access Journals (Sweden)

Andrew C. Singer

2008-11-01

Full Text Available Level-crossing analog-to-digital converters (LC ADCs have been considered in the literature and have been shown to efficiently sample certain classes of signals. One important aspect of their implementation is the placement of reference levels in the converter. The levels need to be appropriately located within the input dynamic range, in order to obtain samples efficiently. In this paper, we study optimization of the performance of such an LC ADC by providing several sequential algorithms that adaptively update the ADC reference levels. The accompanying performance analysis and simulation results show that as the signal length grows, the performance of the sequential algorithms asymptotically approaches that of the best choice that could only have been chosen in hindsight within a family of possible schemes.

Broadband nanophotonic wireless links and networks using on-chip integrated plasmonic antennas.

Science.gov (United States)

Yang, Yuanqing; Li, Qiang; Qiu, Min

2016-01-19

Owing to their high capacity and flexibility, broadband wireless communications have been widely employed in radio and microwave regimes, playing indispensable roles in our daily life. Their optical analogs, however, have not been demonstrated at the nanoscale. In this paper, by exploiting plasmonic nanoantennas, we demonstrate the complete design of broadband wireless links and networks in the realm of nanophotonics. With a 100-fold enhancement in power transfer superior to previous designs as well as an ultrawide bandwidth that covers the entire telecommunication wavelength range, such broadband nanolinks and networks are expected to pave the way for future optical integrated nanocircuits.

Data input from an analog-to-digital converter into the M-6000 computer

International Nuclear Information System (INIS)

Kalashnikov, A.M.; Sheremet'ev, A.K.

1978-01-01

A device for spectrometric data input from the ADC-4096 into the M-6000 computer memory operating in the information storage regime is described. The input device made on integrated circuits coordinates signal levels of the fast response analog-to-digital converter and computer with the help of resistors and inverters. Besides, the input forms a strobe to trigger an increment channel used to record information into the computer memory. The use of the input device permits to get rid of the intermediate information storage in the analyzer memory and ensures fast response of the devices

Increasing capacity of baseband digital data communication networks

Science.gov (United States)

Frankel, Robert S.; Herman, Alexander

1985-01-01

This invention provides broadband network capabilities for baseband digital collision detection transceiver equipment for communication between a plurality of data stations by affording simultaneous transmission of multiple channels over a broadband pass transmission link such as a coaxial cable. Thus, a fundamental carrier wave is transmitted on said link, received at local data stations and used to detect signals on different baseband channels for reception. For transmission the carrier wave typically is used for segregating a plurality of at least two transmission channels into typically single sideband upper and lower pass bands of baseband bandwidth capability adequately separated with guard bands to permit simple separation for receiving by means of pass band filters, etc.

Increasing capacity of baseband digital data communication networks

International Nuclear Information System (INIS)

Frankel, R. S.; Herman, A.

1985-01-01

This invention provides broadband network capabilities for baseband digital collision detection transceiver equipment for communication between a plurality of data stations by affording simultaneous transmission of multiple channels over a broadband pass transmission link such as a coaxial cable. Thus, a fundamental carrier wave is transmitted on said link, received at local data stations and used to detect signals on different baseband channels for reception. For transmission the carrier wave typically is used for segregating a plurality of at least two transmission channels into typically single sideband upper and lower pass bands of baseband bandwidth capability adequately separated with guard bands to permit simple separation for receiving by means of pass band filters, etc

Demonstrations of analog-to-digital conversion using a frequency domain stretched processor.

Science.gov (United States)

Reibel, Randy Ray; Harrington, Calvin; Dahl, Jason; Ostrander, Charles; Roos, Peter Aaron; Berg, Trenton; Mohan, R Krishna; Neifeld, Mark A; Babbitt, Wm R

2009-07-06

The first proof-of-concept demonstrations are presented for a broadband photonic-assisted analog-to-digital converter (ADC) based on spatial spectral holography (SSH). The SSH-ADC acts as a frequency-domain stretch processor converting high bandwidth input signals to low bandwidth output signals, allowing the system to take advantage of high performance, low bandwidth electronic ADCs. Demonstrations with 50 MHz effective bandwidth are shown to highlight basic performance with approximately 5 effective bits of vertical resolution. Signal capture with 1600 MHz effective bandwidth is also shown. Because some SSH materials span over 100 GHz and have large time apertures (approximately 10 micros), this technique holds promise as a candidate for the next generation of ADCs.

LinkMind: Link Optimization in Swarming Mobile Sensor Networks

DEFF Research Database (Denmark)

Ngo, Trung Dung

2012-01-01

of the most advantageous properties of the swarming wireless sensor network is that mobile nodes can work cooperatively to organize an ad-hoc network and optimize the network link capacity to maximize the transmission of gathered data from a source to a target. This paper describes a new method of link...... optimization of swarming mobile sensor networks. The new method is based on combination of the artificial potential force guaranteeing connectivities of the mobile sensor nodes and the max-flow min-cut theorem of graph theory ensuring optimization of the network link capacity. The developed algorithm...

FPGA implementation of a single-input fuzzy logic controller for boost converter with the absence of an external analog-to-digital converter

DEFF Research Database (Denmark)

Taeed, Fazel; Salam, Z.; Ayob, S.

2012-01-01

converter (ADC). Instead, a simple analog-to-digital conversion scheme is implemented using the FPGA itself. Due to the simplicity of the SIFLC algorithm and the absence of an external ADC, the overall implementation requires only 408 logic elements and five input-output pins of the FPGA.......) and applied on a 50-W boost converter. The SIFLC is compared to the proportional-integral controller; the simulation and practical results indicate that SIFLC exhibits excellent performance for step load and input reference changes. Another feature of this work is the absence of an external analog-to-digital...

Digital and Analog Electronics for an autonomous, deep-sea, Gamma Ray Burst Neutrino prototype detector

Directory of Open Access Journals (Sweden)

Manolopoulos K.

2016-01-01

Full Text Available GRBNeT is a Gamma Ray Burst Neutrino Telescope made of autonomously operated arrays of deep-sea light detectors, anchored to the sea-bed without any cabled connection to the shore. This paper presents the digital and analog electronics that we have designed and developed for the GRBNeT prototype. We describe the requirements for these electronics and present their design and functionality. We present low-power analog electronics for the PMTs utilized in the GRBNeT prototype and the FPGA based digital system for data selection and storage. We conclude with preliminary performance measurements of the electronics systems for the GRBNeT prototype.

Design of a 12-bit 80-MS/s CMOS digital-to-analog converter for PLC-VDSL applications

Science.gov (United States)

Ruiz-Amaya, Jesus; Delgado-Restituto, Manuel; Fernandez-Bootello, J. Francisco; de la Rosa, Jose M.

2005-06-01

This paper describes the design of a 12-bit 80MS/s Digital-to-Analog converter implemented in 0.13mm CMOS logic technology. The design has been computer-aided by a developed toolbox for the simulation and verification of Nyquist-Rate Analog-to-Digital and Digital-to-Analog converters in MATLAB. The embedded simulator uses SIMULINK C-coded S-functions to model all required subcircuits including their main error mechanisms. This approach allows to drastically speed up the simulation CPU-time and makes the proposed tool an advantageous alternative for fast exploration of requirements and as a design validation tool. The converter is segmented in a unary current-cell matrix for 8 MSB's and a binary-weighted array for 4 LSB's. Current sources of the converter are laid out separately from current-cell switching matrix core block and distribute in double centroid to reduce random errors and transient noise coupling. The linearity errors caused by remaining gradient errors are reduced by a modified Q2 Random-Walk switching sequence. Simulation results show that the Spurious-Free Dynamic-Range is better than 58.5dB up to 80MS/s. The estimated Signal-to-Noise Distortion Ratio yield is 99.7% and it is supposed to be better than 58dB from DC to Nyquist frequency. Multi-Tone Power Ratio is higher 59dB for several DMT test signals. The converter dissipates less than 129mW from a 3.3V supply and occupies less than 1.7mm2 die area. The results have been checked with all process corners from -40° to 85° and power supply from 3V to 3.6V.

A REVIEW OF HUMAN-SYSTEM INTERFACE DESIGN ISSUES OBSERVED DURING ANALOG-TO-DIGITAL AND DIGITAL-TO-DIGITAL MIGRATIONS IN U.S. NUCLEAR POWER PLANTS

Energy Technology Data Exchange (ETDEWEB)

Kovesdi, C.; Joe, J.

2017-05-01

The United States (U.S.) Department of Energy (DOE) Light Water Reactor Sustainability (LWRS) program is developing a scientific basis through targeted research and development (R&D) to support the U.S. nuclear power plant (NPP) fleet in extending their existing licensing period and ensuring their long-term reliability, productivity, safety, and security. Over the last several years, human factors engineering (HFE) professionals at the Idaho National Laboratory (INL) have supported the LWRS Advanced Instrumentation, Information, and Control (II&C) System Technologies pathway across several U.S. commercial NPPs in analog-to-digital migrations (i.e., turbine control systems) and digital-to-digital migrations (i.e., Safety Parameter Display System). These efforts have included in-depth human factors evaluation of proposed human-system interface (HSI) design concepts against established U.S. Nuclear Regulatory Commission (NRC) design guidelines from NUREG-0700, Rev 2 to inform subsequent HSI design prior to transitioning into Verification and Validation. This paper discusses some of the overarching design issues observed from these past HFE evaluations. In addition, this work presents some observed challenges such as common tradeoffs utilities are likely to face when introducing new HSI technologies into NPP hybrid control rooms. The primary purpose of this work is to distill these observed design issues into general HSI design guidance that industry can use in early stages of HSI design.

Software complex for finding the path routings in synchronous digital hierarchy networks

Directory of Open Access Journals (Sweden)

V. A. Bulanov

2014-01-01

Full Text Available Communication network constructions based on the synchronous digital hierarchy (SDH are widely used in design and operation of telephone networks and data transfer ones on the basis of dedicated links. The providing the link for data transmission from one node to another one is a nontrivial objective. The network equipment vendors, as a rule, may provide also a network system control. However, these systems can be used only with the manufacturer's equipment, but are not intended for finding the optimal paths for the current network operation. They serve for examination to choose a network structure at the stage of its development or modernization for the known in advance matrix of connections. From the practice it is seen that the real networks structures use diverse equipment. Therefore to develop a complex to find the paths in SDH-based network is a challenge.Dijkstra algorithm is implemented to find the shortest network path routings in the complex. The use of the classical algorithm is impossible because of the restrictions in providing main and reserve links. There are multiplex sections with no routes to be expected. Such restriction is due to real arrangement of some multiplex sections in the same cables, but in different fibres. When providing the main link, the appropriate structuring sections should be preferable. For example, the link E3 (34 Mbit/s can pass only across the section of relevant configuration. The reserve link cannot pass across those multiplex sections where the main link has passed. This rule is not 'extra' considering the first restriction since the main and reserve link sections cannot crisscross the node. At the dead ends reserving has no sense, and the reserve link has to coincide with the main one to save a multiplex section resource of terminal switching. In implementation all these restrictions have been taken into consideration.In addition to the path routings, complex enables saving information on the network

Development and application of all-digital monitoring system

International Nuclear Information System (INIS)

Xu Tao; Li Jing; Wang Wei

2014-01-01

All digital control system has developed into a mainstream means of monitoring, and achieved information, intelligence, and networking. All-digital control system is characterized by clear image, large transport stream, so the higher the data storage and network bandwidth should be required. Existing analog surveillance system architecture, hardware and software configuration can not meet the requirements of all-digital monitoring system, so how to solve the original analog surveillance system is gradually transformed into fully digital monitoring system, to avoid incompatibility issues in surveillance monitoring system upgrade become a research project. This paper describes the advantages and future direction of megapixels camera and proposes key technologies to solve the resolution and frame rate with the actual project requirements, achieves a core technology of megapixels video surveillance system, and proposes solutions for the actual renovation project problems. (authors)

Analog Readout and Digitizing System for ATLAS TileCal Demonstrator

CERN Document Server

Tang, F; The ATLAS collaboration

2014-01-01

The TileCal Demonstrator is a prototype for a future upgrade to the ATLAS hadron calorimeter when the Large Hadron Collider increases luminosity in year 2023 (HL-LHC). It will be used for functionality and performance tests. The Demonstrator has 48 channels of upgraded readout and digitizing electronics and a new digital trigger capability, but is backwards-compatible with the present detector system insofar as it also provides analog trigger signals. The Demonstrator is comprised of 4 identical mechanical mini-drawers, each equipped with up to 12 photomultipliers (PMTs). The on-detector electronics includes 45 Front-End Boards, each serving an individual PMT; 4 Main Boards, each to control and digitize up to 12 PMT signals, and 4 corresponding high-speed Daughter Boards serving as data hubs between on-detector and off-detector electronics. The Demonstrator is fully compatible with the present system, accepting ATLAS triggers, timing and slow control commands for the data acquisition, detector control, and de...

A Loudness Function for Analog and Digital Sound Systems based on Equal Loudness Level Contours

DEFF Research Database (Denmark)

Nielsen, Sofus Birkedal

2016-01-01

frequency balance will been changed both for LL lower or higher than ML. The differences in ELLC ask for a level based equalization using fractional-order filters. A designing technique for both analog and digital fractional-order filters was developed. The analog solution is based on OPAMs and the digital......A new and better loudness compensation has been designed based on the differences between the Equal Loudness Level Contours (ELLC) in ISO 226:2003. Sound productions are normally being mixed at a high mixing level (ML) but often played at lower listening level (LL) which mean that the perceived...

Simulation of continuously logical base cells (CL BC) with advanced functions for analog-to-digital converters and image processors

Science.gov (United States)

Krasilenko, Vladimir G.; Lazarev, Alexander A.; Nikitovich, Diana V.

2017-10-01

The paper considers results of design and modeling of continuously logical base cells (CL BC) based on current mirrors (CM) with functions of preliminary analogue and subsequent analogue-digital processing for creating sensor multichannel analog-to-digital converters (SMC ADCs) and image processors (IP). For such with vector or matrix parallel inputs-outputs IP and SMC ADCs it is needed active basic photosensitive cells with an extended electronic circuit, which are considered in paper. Such basic cells and ADCs based on them have a number of advantages: high speed and reliability, simplicity, small power consumption, high integration level for linear and matrix structures. We show design of the CL BC and ADC of photocurrents and their various possible implementations and its simulations. We consider CL BC for methods of selection and rank preprocessing and linear array of ADCs with conversion to binary codes and Gray codes. In contrast to our previous works here we will dwell more on analogue preprocessing schemes for signals of neighboring cells. Let us show how the introduction of simple nodes based on current mirrors extends the range of functions performed by the image processor. Each channel of the structure consists of several digital-analog cells (DC) on 15-35 CMOS. The amount of DC does not exceed the number of digits of the formed code, and for an iteration type, only one cell of DC, complemented by the device of selection and holding (SHD), is required. One channel of ADC with iteration is based on one DC-(G) and SHD, and it has only 35 CMOS transistors. In such ADCs easily parallel code can be realized and also serial-parallel output code. The circuits and simulation results of their design with OrCAD are shown. The supply voltage of the DC is 1.8÷3.3V, the range of an input photocurrent is 0.1÷24μA, the transformation time is 20÷30nS at 6-8 bit binary or Gray codes. The general power consumption of the ADC with iteration is only 50÷100μW, if the

Digital Denmark: From Information Society to Network Society

DEFF Research Database (Denmark)

Henten, Anders; Falch, Morten

2000-01-01

for a welfare society. However, globalisation and the spreading use of new information and communication technologies and services challenge this position. This article examines Denmark's performance in implementing its IS 2000 plans, the background to the Digital Denmark report, and its implications......The Danish Government recently issued a new policy report, Digital Denmark, on the "conversion to a network society", as a successor to its Information Society 2000 report (1994). This is part of a new round of information society policy vision statements that are, or will be forthcoming from...... national governments everywhere. Denmark provides an interesting case study because it ranks high in the benchmark indicators of information network society developments. This position has been obtained largely by public sector initiatives and without erosion of the highly reputed Scandinavian model...

Digital Hydrologic Networks Supporting Applications Related to Spatially Referenced Regression Modeling

Science.gov (United States)

Brakebill, J.W.; Wolock, D.M.; Terziotti, S.E.

2011-01-01

Digital hydrologic networks depicting surface-water pathways and their associated drainage catchments provide a key component to hydrologic analysis and modeling. Collectively, they form common spatial units that can be used to frame the descriptions of aquatic and watershed processes. In addition, they provide the ability to simulate and route the movement of water and associated constituents throughout the landscape. Digital hydrologic networks have evolved from derivatives of mapping products to detailed, interconnected, spatially referenced networks of water pathways, drainage areas, and stream and watershed characteristics. These properties are important because they enhance the ability to spatially evaluate factors that affect the sources and transport of water-quality constituents at various scales. SPAtially Referenced Regressions On Watershed attributes (SPARROW), a process-based/statistical model, relies on a digital hydrologic network in order to establish relations between quantities of monitored contaminant flux, contaminant sources, and the associated physical characteristics affecting contaminant transport. Digital hydrologic networks modified from the River Reach File (RF1) and National Hydrography Dataset (NHD) geospatial datasets provided frameworks for SPARROW in six regions of the conterminous United States. In addition, characteristics of the modified RF1 were used to update estimates of mean-annual streamflow. This produced more current flow estimates for use in SPARROW modeling. ?? 2011 American Water Resources Association. This article is a U.S. Government work and is in the public domain in the USA.

Digital intelligent booster for DCC miniature train networks

Science.gov (United States)

Ursu, M. P.; Condruz, D. A.

2017-08-01

Modern miniature trains are now driven by means of the DCC (Digital Command and Control) system, which allows the human operator or a personal computer to launch commands to each individual train or even to control different features of the same train. The digital command station encodes these commands and sends them to the trains by means of electrical pulses via the rails of the railway network. Due to the development of the miniature railway network, it may happen that the power requirement of the increasing number of digital locomotives, carriages and accessories exceeds the nominal output power of the digital command station. This digital intelligent booster relieves the digital command station from powering the entire railway network all by itself, and it automatically handles the multiple powered sections of the network. This electronic device is also able to detect and process short-circuits and overload conditions, without the intervention of the digital command station.

Time-Interleaved Analog to Digital Converters

NARCIS (Netherlands)

Louwsma, S.M.; van Tuijl, Adrianus Johannes Maria; Nauta, Bram

2010-01-01

This book describes the research carried out by our PhD student Simon Louwsma at the University of Twente, The Netherlands in the field of high-speed Analogto- Digital (AD) converters. AD converters are crucial circuits for modern systems where information is stored or processed in digital form. Due

A behavioral simulator for switched-capacitor sigma-delta modulator analog-to-digital converter

International Nuclear Information System (INIS)

San, H. Y.; Rezaul Hasan, S. M.

1998-01-01

In this paper, a PC-based simulator for state of the art oversampled switched-capacitor sigma-delta analog-to-digital converters is presented. The proposed simulator employs behavioral model of switched-capacitor integrator and non-linear quantizer to stimulate the system. The behavioral simulation of the integrator is also verified with SPICE. The simulator is fully integrated and standalone. It integrates an input netlist file interpreter, a behavioral simulator, a generic part library and a powerful post-processor to evaluate the SNR, SDR And TSNR. Both passive and active sensitivities can be investigated by the proposed simulator. The simulator is coded in C++, and is very fast

An Analog-Digital Mixed Measurement Method of Inductive Proximity Sensor

Directory of Open Access Journals (Sweden)

Yi-Xin Guo

2015-12-01

Full Text Available Inductive proximity sensors (IPSs are widely used in position detection given their unique advantages. To address the problem of temperature drift, this paper presents an analog-digital mixed measurement method based on the two-dimensional look-up table. The inductance and resistance components can be separated by processing the measurement data, thus reducing temperature drift and generating quantitative outputs. This study establishes and implements a two-dimensional look-up table that reduces the online computational complexity through structural modeling and by conducting an IPS operating principle analysis. This table is effectively compressed by considering the distribution characteristics of the sample data, thus simplifying the processing circuit. Moreover, power consumption is reduced. A real-time, built-in self-test (BIST function is also designed and achieved by analyzing abnormal sample data. Experiment results show that the proposed method obtains the advantages of both analog and digital measurements, which are stable, reliable, and taken in real time, without the use of floating-point arithmetic and process-control-based components. The quantitative output of displacement measurement accelerates and stabilizes the system control and detection process. The method is particularly suitable for meeting the high-performance requirements of the aviation and aerospace fields.

Digital radiology and digitally formatted image management systems

International Nuclear Information System (INIS)

Cox, G.G.; Dwyer, S.J. III; Templeton, A.W.

1987-01-01

The number of diagnostic examinations performed with digitally formatted imaging equipment is increasing. Digital general-purpose and fluoroscopic radiology systems are being clinically evaluated. Digitizing conventional x-ray films, such as mammograms, frequently improves the diagnostic quality of the images. The digitizing process with laser has also afforded the opportunity to document required spatial resolution for digital imaging and network systems. The use of digitally formatted image instrumentation imposes new requirements on the acquisition, display and manipulation, transmission, hard copy image recording, and archiving of diagnostic data. Networking of digitally formatted image data offers many advantages for managing digital information. This paper identifies and describes digital radiographic systems. Parameters required for designing and implementing a digital image management system are outlined. Spatial and contrast resolution requirements are identified. The key parameters include the amount of image data generated each working day, the retrieval rate of the generated data, the display hardware and software needed for interactive diagnosis display stations, the requirements for analog hard copy generation, and on-line and long-term archiving requirements. These image management systems are often called PACS (Picture Archiving and Communication Systems)

REDEN: Named Entity Linking in Digital Literary Editions Using Linked Data Sets

Directory of Open Access Journals (Sweden)

Carmen Brando

2016-07-01

Full Text Available This paper proposes a graph-based Named Entity Linking (NEL algorithm named REDEN for the disambiguation of authors’ names in French literary criticism texts and scientific essays from the 19th and early 20th centuries. The algorithm is described and evaluated according to the two phases of NEL as reported in current state of the art, namely, candidate retrieval and candidate selection. REDEN leverages knowledge from different Linked Data sources in order to select candidates for each author mention, subsequently crawls data from other Linked Data sets using equivalence links (e.g., owl:sameAs, and, finally, fuses graphs of homologous individuals into a non-redundant graph well-suited for graph centrality calculation; the resulting graph is used for choosing the best referent. The REDEN algorithm is distributed in open-source and follows current standards in digital editions (TEI and semantic Web (RDF. Its integration into an editorial workflow of digital editions in Digital humanities and cultural heritage projects is entirely plausible. Experiments are conducted along with the corresponding error analysis in order to test our approach and to help us to study the weaknesses and strengths of our algorithm, thereby to further improvements of REDEN.

Multisensor transducer based on a parallel fiber optic digital-to-analog converter

Directory of Open Access Journals (Sweden)

Grechishnikov Vladimir

2017-01-01

Full Text Available Considered possibility of creating a multisensory information converter (MSPI based on new fiber-optic functional element-digital-to-analog (DAC fiber optic converter. The use of DAC fiber-optic provides jamming immunity combined with low weight and cost of indicators .Because of that MSPI scheme was developed based on parallel DAC fiber-optic (Russian Federation Patent 157416. We came up with an equation for parallel DAC fiber-optic. An eleborate general mathematical model of the proposed converter. Developed a method for reducing conversion errors by placing the DAC transfer function between i and i + 1 ADC quantization levels. By using this model it allows you to obtain reliable information about the technical capabilities of a converter without the need for costly experiments.

Network worlds : from link analysis to virtual places.

Energy Technology Data Exchange (ETDEWEB)

Joslyn, C. (Cliff)

2002-01-01

Significant progress is being made in knowledge systems through recent advances in the science of very large networks. Attention is now turning in many quarters to the potential impact on counter-terrorism methods. After reviewing some of these advances, we will discuss the difference between such 'network analytic' approaches, which focus on large, homogeneous graph strucures, and what we are calling 'link analytic' approaches, which focus on somewhat smaller graphs with heterogeneous link types. We use this venue to begin the process of rigorously defining link analysis methods, especially the concept of chaining of views of multidimensional databases. We conclude with some speculation on potential connections to virtual world architectures.

Effects of analog and digital filtering on auditory middle latency responses in adults and young children.

Science.gov (United States)

Suzuki, T; Hirabayashi, M; Kobayashi, K

1984-01-01

Effects of analog high pass (HP) filtering were compared with those of zero phase-shift digital filtering on the auditory middle latency responses (MLR) from nine adults and 16 young children with normal hearing. Analog HP filtering exerted several prominent effects on the MLR waveforms in both adults and young children, such as suppression of Po (ABR), enhancement of Nb, enhancement or emergence of Pb, and latency decrements for Pa and the later components. Analog HP filtering at 20 Hz produced more pronounced waveform distortions in the responses from young children than from adults. Much greater latency decrements for Pa and Nb were observed for young children than for adults in the analog HP-filtered responses at 20 Hz. A large positive peak (Pb) emerged at about 65 ms after the stimulus onset. From these results, the use of digital HP filtering at 20 Hz is strongly recommended for obtaining unbiased and stable MLR in young children.

LinkMind: link optimization in swarming mobile sensor networks.

Science.gov (United States)

Ngo, Trung Dung

2011-01-01

A swarming mobile sensor network is comprised of a swarm of wirelessly connected mobile robots equipped with various sensors. Such a network can be applied in an uncertain environment for services such as cooperative navigation and exploration, object identification and information gathering. One of the most advantageous properties of the swarming wireless sensor network is that mobile nodes can work cooperatively to organize an ad-hoc network and optimize the network link capacity to maximize the transmission of gathered data from a source to a target. This paper describes a new method of link optimization of swarming mobile sensor networks. The new method is based on combination of the artificial potential force guaranteeing connectivities of the mobile sensor nodes and the max-flow min-cut theorem of graph theory ensuring optimization of the network link capacity. The developed algorithm is demonstrated and evaluated in simulation.

LinkMind: Link Optimization in Swarming Mobile Sensor Networks

Directory of Open Access Journals (Sweden)

Trung Dung Ngo

2011-08-01

Full Text Available A swarming mobile sensor network is comprised of a swarm of wirelessly connected mobile robots equipped with various sensors. Such a network can be applied in an uncertain environment for services such as cooperative navigation and exploration, object identification and information gathering. One of the most advantageous properties of the swarming wireless sensor network is that mobile nodes can work cooperatively to organize an ad-hoc network and optimize the network link capacity to maximize the transmission of gathered data from a source to a target. This paper describes a new method of link optimization of swarming mobile sensor networks. The new method is based on combination of the artificial potential force guaranteeing connectivities of the mobile sensor nodes and the max-flow min-cut theorem of graph theory ensuring optimization of the network link capacity. The developed algorithm is demonstrated and evaluated in simulation.

[Analog gamma camera digitalization computer system].

Science.gov (United States)

Rojas, G M; Quintana, J C; Jer, J; Astudillo, S; Arenas, L; Araya, H

2004-01-01

Digitalization of analogue gamma cameras systems, using special acquisition boards in microcomputers and appropriate software for acquisition and processing of nuclear medicine images is described in detail. Microcomputer integrated systems interconnected by means of a Local Area Network (LAN) and connected to several gamma cameras have been implemented using specialized acquisition boards. The PIP software (Portable Image Processing) was installed on each microcomputer to acquire and preprocess the nuclear medicine images. A specialized image processing software has been designed and developed for these purposes. This software allows processing of each nuclear medicine exam, in a semiautomatic procedure, and recording of the results on radiological films. . A stable, flexible and inexpensive system which makes it possible to digitize, visualize, process, and print nuclear medicine images obtained from analogue gamma cameras was implemented in the Nuclear Medicine Division. Such a system yields higher quality images than those obtained with analogue cameras while keeping operating costs considerably lower (filming: 24.6%, fixing 48.2% and developing 26%.) Analogue gamma camera systems can be digitalized economically. This system makes it possible to obtain optimal clinical quality nuclear medicine images, to increase the acquisition and processing efficiency, and to reduce the steps involved in each exam.

Design of pressure-driven microfluidic networks using electric circuit analogy.

Science.gov (United States)

Oh, Kwang W; Lee, Kangsun; Ahn, Byungwook; Furlani, Edward P

2012-02-07

This article reviews the application of electric circuit methods for the analysis of pressure-driven microfluidic networks with an emphasis on concentration- and flow-dependent systems. The application of circuit methods to microfluidics is based on the analogous behaviour of hydraulic and electric circuits with correlations of pressure to voltage, volumetric flow rate to current, and hydraulic to electric resistance. Circuit analysis enables rapid predictions of pressure-driven laminar flow in microchannels and is very useful for designing complex microfluidic networks in advance of fabrication. This article provides a comprehensive overview of the physics of pressure-driven laminar flow, the formal analogy between electric and hydraulic circuits, applications of circuit theory to microfluidic network-based devices, recent development and applications of concentration- and flow-dependent microfluidic networks, and promising future applications. The lab-on-a-chip (LOC) and microfluidics community will gain insightful ideas and practical design strategies for developing unique microfluidic network-based devices to address a broad range of biological, chemical, pharmaceutical, and other scientific and technical challenges.

Analog and hybrid computing

CERN Document Server

Hyndman, D E

2013-01-01

Analog and Hybrid Computing focuses on the operations of analog and hybrid computers. The book first outlines the history of computing devices that influenced the creation of analog and digital computers. The types of problems to be solved on computers, computing systems, and digital computers are discussed. The text looks at the theory and operation of electronic analog computers, including linear and non-linear computing units and use of analog computers as operational amplifiers. The monograph examines the preparation of problems to be deciphered on computers. Flow diagrams, methods of ampl

Digital Native and Digital Immigrant Use of Scholarly Network for Doctoral Learners

OpenAIRE

Ronald Berman; Deliesha Hassell

2014-01-01

The Doctoral Community Network (DC) is a learner driven, scholarly community designed to help online doctoral learners successfully complete their dissertation and program of study. While digital natives grew up in an environment immersed in technology, digital immigrants adapted to this environment through their ability to learn and adjust to new technologies. With several thousand Doctoral Community Network users, it was not known to what extent digital immigrants had embraced the technolog...

Diagnostic Neural Network Systems for the Electronic Circuits

International Nuclear Information System (INIS)

Mohamed, A.H.

2014-01-01

Neural Networks is one of the most important artificial intelligent approaches for solving the diagnostic processes. This research concerns with uses the neural networks for diagnosis of the electronic circuits. Modern electronic systems contain both the analog and digital circuits. But, diagnosis of the analog circuits suffers from great complexity due to their nonlinearity. To overcome this problem, the proposed system introduces a diagnostic system that uses the neural network to diagnose both the digital and analog circuits. So, it can face the new requirements for the modern electronic systems. A fault dictionary method was implemented in the system. Experimental results are presented on three electronic systems. They are: artificial kidney, wireless network and personal computer systems. The proposed system has improved the performance of the diagnostic systems when applied for these practical cases

Method and apparatus for clockless analog-to-digital conversion and peak detection

Science.gov (United States)

DeGeronimo, Gianluigi

2007-03-06

An apparatus and method for analog-to-digital conversion and peak detection includes at least one stage, which includes a first switch, second switch, current source or capacitor, and discriminator. The discriminator changes state in response to a current or charge associated with the input signal exceeding a threshold, thereby indicating whether the current or charge associated with the input signal is greater than the threshold. The input signal includes a peak or a charge, and the converter includes a peak or charge detect mode in which a state of the switch is retained in response to a decrease in the current or charge associated with the input signal. The state of the switch represents at least a portion of a value of the peak or of the charge.

Cascade of links in complex networks

Energy Technology Data Exchange (ETDEWEB)

Feng, Yeqian; Sun, Bihui [Department of Management Science, School of Government, Beijing Normal University, 100875 Beijing (China); Zeng, An, E-mail: anzeng@bnu.edu.cn [School of Systems Science, Beijing Normal University, 100875 Beijing (China)

2017-01-30

Cascading failure is an important process which has been widely used to model catastrophic events such as blackouts and financial crisis in real systems. However, so far most of the studies in the literature focus on the cascading process on nodes, leaving the possibility of link cascade overlooked. In many real cases, the catastrophic events are actually formed by the successive disappearance of links. Examples exist in the financial systems where the firms and banks (i.e. nodes) still exist but many financial trades (i.e. links) are gone during the crisis, and the air transportation systems where the airports (i.e. nodes) are still functional but many airlines (i.e. links) stop operating during bad weather. In this letter, we develop a link cascade model in complex networks. With this model, we find that both artificial and real networks tend to collapse even if a few links are initially attacked. However, the link cascading process can be effectively terminated by setting a few strong nodes in the network which do not respond to any link reduction. Finally, a simulated annealing algorithm is used to optimize the location of these strong nodes, which significantly improves the robustness of the networks against the link cascade. - Highlights: • We propose a link cascade model in complex networks. • Both artificial and real networks tend to collapse even if a few links are initially attacked. • The link cascading process can be effectively terminated by setting a few strong nodes. • A simulated annealing algorithm is used to optimize the location of these strong nodes.

Cascade of links in complex networks

International Nuclear Information System (INIS)

Feng, Yeqian; Sun, Bihui; Zeng, An

2017-01-01

Cascading failure is an important process which has been widely used to model catastrophic events such as blackouts and financial crisis in real systems. However, so far most of the studies in the literature focus on the cascading process on nodes, leaving the possibility of link cascade overlooked. In many real cases, the catastrophic events are actually formed by the successive disappearance of links. Examples exist in the financial systems where the firms and banks (i.e. nodes) still exist but many financial trades (i.e. links) are gone during the crisis, and the air transportation systems where the airports (i.e. nodes) are still functional but many airlines (i.e. links) stop operating during bad weather. In this letter, we develop a link cascade model in complex networks. With this model, we find that both artificial and real networks tend to collapse even if a few links are initially attacked. However, the link cascading process can be effectively terminated by setting a few strong nodes in the network which do not respond to any link reduction. Finally, a simulated annealing algorithm is used to optimize the location of these strong nodes, which significantly improves the robustness of the networks against the link cascade. - Highlights: • We propose a link cascade model in complex networks. • Both artificial and real networks tend to collapse even if a few links are initially attacked. • The link cascading process can be effectively terminated by setting a few strong nodes. • A simulated annealing algorithm is used to optimize the location of these strong nodes.

Development and Comparative Study of Effects of Training Algorithms on Performance of Artificial Neural Network Based Analog and Digital Automatic Modulation Recognition

Directory of Open Access Journals (Sweden)

Jide Julius Popoola

2015-11-01

Full Text Available This paper proposes two new classifiers that automatically recognise twelve combined analog and digital modulated signals without any a priori knowledge of the modulation schemes and the modulation parameters. The classifiers are developed using pattern recognition approach. Feature keys extracted from the instantaneous amplitude, instantaneous phase and the spectrum symmetry of the simulated signals are used as inputs to the artificial neural network employed in developing the classifiers. The two developed classifiers are trained using scaled conjugate gradient (SCG and conjugate gradient (CONJGRAD training algorithms. Sample results of the two classifiers show good success recognition performance with an average overall recognition rate above 99.50% at signal-to-noise ratio (SNR value from 0 dB and above with the two training algorithms employed and an average overall recognition rate slightly above 99.00% and 96.40% respectively at - 5 dB SNR value for SCG and CONJGRAD training algorithms. The comparative performance evaluation of the two developed classifiers using the two training algorithms shows that the two training algorithms have different effects on both the response rate and efficiency of the two developed artificial neural networks classifiers. In addition, the result of the performance evaluation carried out on the overall success recognition rates between the two developed classifiers in this study using pattern recognition approach with the two training algorithms and one reported classifier in surveyed literature using decision-theoretic approach shows that the classifiers developed in this study perform favourably with regard to accuracy and performance probability as compared to classifier presented in previous study.

Networked Instrumentation Element

Data.gov (United States)

National Aeronautics and Space Administration — Armstrong researchers have developed a networked instrumentation system that connects modern experimental payloads to existing analog and digital communications...

Digital networks for the image management

International Nuclear Information System (INIS)

Gomez del Campo L, A.

1999-01-01

The digital networks designed specifically for the X-ray departments in the hospitals already were found in open development at beginning the 80's decade. Actually the digital network will be present include the image generation without the necessity to use film in direct form and in its case to print it through a laser ray printers network, an electronic image file, the possibility to integrate the hospitable information system to the electronic expedient which will allow communicate radiograph electronic files and consult by satellite via the problem cases. (Author)

An introduction to computer networks

CERN Document Server

Rizvi, SAM

2011-01-01

AN INTRODUCTION TO COMPUTER NETWORKS is a comprehensive text book which is focused and designed to elaborate the technical contents in the light of TCP/IP reference model exploring both digital and analog data communication. Various communication protocols of different layers are discussed along with their pseudo-code. This book covers the detailed and practical information about the network layer alongwith information about IP including IPV6, OSPF, and internet multicasting. It also covers TCP congestion control and emphasizes on the basic principles of fundamental importance concerning the technology and architecture and provides detailed discussion of leading edge topics of data communication, LAN & Network Layer.

Digital Identity Formation: Socially Being Real and Present on Digital Networks

Science.gov (United States)

Bozkurt, Aras; Tu, Chih-Hsiung

2016-01-01

Social networks have become popular communication and interaction environments recently. As digital environments, so as ecosystems, they have potential in terms of networked learning as they fulfill some roles such as mediating an environment for digital identity formation and providing social and emotional presence. Based on this phenomenon, the…

A study on the digital image transfer application mass chest X-ray system up-grade

International Nuclear Information System (INIS)

Kim, Sun Chil; Park, Jong Sam; Lee, Jon Il

2003-01-01

By converting movable indirect mass chest X-ray devices for vehicles into digital systems and upgrading it to share information with the hospital's medical image information system, excellencies have been confirmed as a result of installing and running this type of system and are listed hereinafter. Upgrading analog systems, such as indirect mass chest X-ray devices dependent on printed film, to digital systems allows them to be run and managed much more efficiently, contributing to the increase in the stability and the efficiency of the system. Unlike existing images, communication based on DICOM standards allow images to be compatible with the hospital's outer and inner network PACS systems, extending the scope of the radiation departments information system. Assuming chest-exclusive indirect mass chest X-rays, a linked development of CAD (Computer Aided Diagnosis, Detector) becomes possible. By applying wireless Internet, Web-PACS for movable indirect mass chest X-ray devices for vehicles will become possible. Research in these fields must continue and if the superior image quality and convenience of digital systems are confirmed, I believe that the conversion of systems still dependent on analog images to modernized digital systems is a must

Proposal for a fast, zero suppressing circuit for the digitization of analog pulses over long memory times

International Nuclear Information System (INIS)

Bourgeois, F.

1984-01-01

This report describes the design principles of a fast (100 MHz) time and pulse height digitizer that can record up to 15 analog pulses over 10-80 μs memory times. Unlike other triggered circuits prepulse samples are recorded without the help of an analog delay line. The low power requirements of the circuit as well as its fast read-out characteristics make it very attractive for detectors with many digitizing channels. Conventional circuits are described as a reference for the evaluation of this new design. An ECL 10 K implementation of the circuit is presented in the third section. (orig.)

Geographical constraints to range-based attacks on links in complex networks

International Nuclear Information System (INIS)

Gong Baihua; Liu Jun; Huang Liang; Yang Kongqing; Yang Lei

2008-01-01

In this paper, we studied range-based attacks on links in geographically constrained scale-free networks and found that there is a continuous switching of roles of short- and long-range attacks on links when tuning the geographical constraint strength. Our results demonstrate that the geography has a significant impact on the network efficiency and security; thus one can adjust the geographical structure to optimize the robustness and the efficiency of the networks. We introduce a measurement of the impact of links on the efficiency of the network, and an effective attacking strategy is suggested

Heterogeneous wireless/wireline optical access networks with the R-EAT as backend component

Science.gov (United States)

Hagedorn, Klaus; Gindera, Ralf; Stohr, Andreas; Jager, Dieter

2004-09-01

A heterogeneous wireless/wireline optical transmission link using a reflection type electroabsorption transceiver (R-EAT) is presented. Simultaneous transmission of full-duplex broadband wireless LAN (WLAN) channels and 1Gb/s base band data is experimentally demonstrated. The system link employs sub-carrier multiplexing (SCM) and two optical channels for full duplex transmission of various analog WLAN channels and downlink digital base band data. The developed link architecture is suitable for simultaneous transmission of broadband wireline and wireless signals, it enables the coexistence and interoperability between wireline and wireless access technologies. The developed R-EAT component employed in this wireline/wireless access system, features "single-chip-component" base stations in access networks with star type topology where only a single optical fiber is used for bidirectional optical transmission. The R-EAT can be used within the optical C-band (1530- 1560nm) and is suitable for (D)WDM networks. Bit error rate measurements demonstrate the capabilities of the R-EAT for 1Gb/s base band transmission. The analog performance for WLAN transmission is characterised by a spurious free dynamic range (SFDR) of more than 75dB and 90dB for uplink and downlink transmission, respectively. The link gain for uplink and downlink transmission is -42dB and -37dB, respectively. The demonstrates the analog performances of the R-EAT for being used in wireless access networks such as W-LAN.

An Evaluation of optional timing/synchronization features to support selection of an optimum design for the DCS digital communication network

Science.gov (United States)

Bradley, D. B.; Cain, J. B., III; Williard, M. W.

1978-01-01

The task was to evaluate the ability of a set of timing/synchronization subsystem features to provide a set of desirable characteristics for the evolving Defense Communications System digital communications network. The set of features related to the approaches by which timing/synchronization information could be disseminated throughout the network and the manner in which this information could be utilized to provide a synchronized network. These features, which could be utilized in a large number of different combinations, included mutual control, directed control, double ended reference links, independence of clock error measurement and correction, phase reference combining, and self organizing.

Cross-linked structure of network evolution

International Nuclear Information System (INIS)

Bassett, Danielle S.; Wymbs, Nicholas F.; Grafton, Scott T.; Porter, Mason A.; Mucha, Peter J.

2014-01-01

We study the temporal co-variation of network co-evolution via the cross-link structure of networks, for which we take advantage of the formalism of hypergraphs to map cross-link structures back to network nodes. We investigate two sets of temporal network data in detail. In a network of coupled nonlinear oscillators, hyperedges that consist of network edges with temporally co-varying weights uncover the driving co-evolution patterns of edge weight dynamics both within and between oscillator communities. In the human brain, networks that represent temporal changes in brain activity during learning exhibit early co-evolution that then settles down with practice. Subsequent decreases in hyperedge size are consistent with emergence of an autonomous subgraph whose dynamics no longer depends on other parts of the network. Our results on real and synthetic networks give a poignant demonstration of the ability of cross-link structure to uncover unexpected co-evolution attributes in both real and synthetic dynamical systems. This, in turn, illustrates the utility of analyzing cross-links for investigating the structure of temporal networks

Cross-linked structure of network evolution

Energy Technology Data Exchange (ETDEWEB)

Bassett, Danielle S., E-mail: dsb@seas.upenn.edu [Department of Bioengineering, University of Pennsylvania, Philadelphia, Pennsylvania 19104 (United States); Department of Physics, University of California, Santa Barbara, California 93106 (United States); Sage Center for the Study of the Mind, University of California, Santa Barbara, California 93106 (United States); Wymbs, Nicholas F.; Grafton, Scott T. [Department of Psychology and UCSB Brain Imaging Center, University of California, Santa Barbara, California 93106 (United States); Porter, Mason A. [Oxford Centre for Industrial and Applied Mathematics, Mathematical Institute, University of Oxford, Oxford OX2 6GG (United Kingdom); CABDyN Complexity Centre, University of Oxford, Oxford, OX1 1HP (United Kingdom); Mucha, Peter J. [Carolina Center for Interdisciplinary Applied Mathematics, Department of Mathematics, University of North Carolina, Chapel Hill, North Carolina 27599 (United States); Department of Applied Physical Sciences, University of North Carolina, Chapel Hill, North Carolina 27599 (United States)

2014-03-15

We study the temporal co-variation of network co-evolution via the cross-link structure of networks, for which we take advantage of the formalism of hypergraphs to map cross-link structures back to network nodes. We investigate two sets of temporal network data in detail. In a network of coupled nonlinear oscillators, hyperedges that consist of network edges with temporally co-varying weights uncover the driving co-evolution patterns of edge weight dynamics both within and between oscillator communities. In the human brain, networks that represent temporal changes in brain activity during learning exhibit early co-evolution that then settles down with practice. Subsequent decreases in hyperedge size are consistent with emergence of an autonomous subgraph whose dynamics no longer depends on other parts of the network. Our results on real and synthetic networks give a poignant demonstration of the ability of cross-link structure to uncover unexpected co-evolution attributes in both real and synthetic dynamical systems. This, in turn, illustrates the utility of analyzing cross-links for investigating the structure of temporal networks.

Digital echocardiography and telemedicine applications in pediatric cardiology.

Science.gov (United States)

Sable, Craig

2002-01-01

Digital echocardiography offers several advantages over videotape, including easy review, comparison, storage, postprocessing, and sharing of studies, quantitative analysis, and superior resolution. Newer echocardiography systems can write digital data to computer hardware, whereas older systems require digitization of analog data. Clinical and digital data compression is required to reduce study size. Clinical compression has been validated in several adult studies and one pediatric study. JPEG and MPEG digital compression ratios of 26:1 and 200:1, respectively, approximate S-videotape quality. JPEG is the DICOM 3.0 standard and is ideal for short loops, serial comparisons, and quantitative analysis. MPEG (the motion picture standard) lends itself to digitization of video streams and may be more attractive to pediatric cardiologists. Options for data storage and transfer range from limited local review to multiple offline review stations linked by a wide-area network. Telemedicine expands the capabilities of digital echocardiography in a "store and forward" or "real-time" format. Real-time neonatal telecardiology is accurate, impacts patient care, is cost-effective, and does not increase utilization. Cost, increased reliance on sonographers' skills, lack of accepted standards, and legal, licensure, and billing issues are obstacles to widespread acceptance of digital echocardiography and telemedicine.

Upgrade Analog Readout and Digitizing System for ATLAS TileCal Demonstrator

CERN Document Server

Tang, F; Anderson, K; Bohm, C; Hildebrand, K; Muschter, S; Oreglia, M

2015-01-01

The TileCal Demonstrator is a prototype for a future upgrade to the ATLAS hadron calorimeter when the Large Hadron Collider increases luminosity in year 2023 (HL-LHC). It will be used for functionality and performance tests. The Demonstrator has 48 channels of upgraded readout and digitizing electronics and a new digital trigger capability, but is backwards-compatible with the present detector system insofar as it also provides analog trigger signals. The Demonstrator is comprised of 4 identical mechanical mini-drawers, each equipped with up to 12 photomultipliers (PMTs). The on-detector electronics includes 45 Front-End Boards, each serving an individual PMT; 4 Main Boards, each to control and digitize up to 12 PMT signals, and 4 corresponding high-speed Daughter Boards serving as data hubs between on-detector and off-detector electronics. The Demonstrator is fully compatible with the present system, accepting ATLAS triggers, timing and slow control commands for the data acquisition, detector control, and de...

HIGH RESOLUTION ANALOG / DIGITAL POWER SUPPLY CONTROLLER

International Nuclear Information System (INIS)

Medvedko, Evgeny A

2003-01-01

Corrector magnets for the SPEAR-3 synchrotron radiation source require precision, high-speed control for use with beam-based orbit feedback. A new Controller Analog/Digital Interface card (CANDI) has been developed for these purposes. The CANDI has a 24-bit DAC for current control and three 24-bit Δ-Σ ADCs to monitor current and voltages. The ADCs can be read and the DAC updated at the 4 kHz rate needed for feedback control. A precision 16-bit DAC provides on-board calibration. Programmable multiplexers control internal signal routing for calibration, testing, and measurement. Feedback can be closed internally on current setpoint, externally on supply current, or beam position. Prototype and production tests are reported in this paper. Noise is better than 17 effective bits in a 10 mHz to 2 kHz bandwidth. Linearity and temperature stability are excellent

A new 12-bit spectroscopy analog-to-digital converter type SAA intended for CAMAC acquisition systems

International Nuclear Information System (INIS)

Borsuk, S.; Kulka, Z.

1989-12-01

A new 12-bit spectroscopy analog-to-digital converter (ADC) type SAA (Successive Approximation type with channel width Averaging) intended for CAMAC acquisition systems is decsribed. ADC type SAA initiates new series of spectroscopy ADC's based on a binary-approximation method in which differential nonlinearity is corrected by a statistical channel width averaging method. The structure and principle of operation, as well as some circuit realizations and specifications of the new converter are described. 41 refs., 5 figs. (author)

Design and characterization of a mixed-signal PCB for digital-to-analog conversion in a modular and scalable infrared scene projector

Science.gov (United States)

Benedict, Jacob

Infra-red (IR) sensors have proven instrumental in a wide variety of fields from military to industrial applications. The proliferation of IR sensors has spawned an intense push for technologies that can test and calibrate the multitudes of IR sensors. One such technology, IR scene projection (IRSP), provides an inexpensive and safe method for the testing of IR sensor devices. Previous efforts have been conducted to develop IRSPs based on super-lattice light emitting diodes (SLEDS). A single-color 512x512 SLEDs system has been developed, produced, and tested as documented in Corey Lange's Master's thesis, and a GOMAC paper by Rodney McGee [1][2]. Current efforts are being undergone to develop a two-color 512x512 SLEDs system designated (TCSA). The following thesis discusses the design and implementation of a custom printed circuit board (PCB), known as the FMC 4DAC, that contains both analog and digital signals. Utilizing two 16-bit digital-to-analog converters (DAC) the purpose of the board is to provide four analog current output channels for driving the TCSA system to a maximum frame rate of 1 kHz. In addition, the board supports a scalable TCSA system architecture. Several copies of the board can be run in parallel to achieve a range of analog channels between 4 and 32.

Mixed Linear/Square-Root Encoded Single Slope Ramp Provides a Fast, Low Noise Analog to Digital Converter with Very High Linearity for Focal Plane Arrays

Science.gov (United States)

Wrigley, Christopher James (Inventor); Hancock, Bruce R. (Inventor); Newton, Kenneth W. (Inventor); Cunningham, Thomas J. (Inventor)

2014-01-01

An analog-to-digital converter (ADC) converts pixel voltages from a CMOS image into a digital output. A voltage ramp generator generates a voltage ramp that has a linear first portion and a non-linear second portion. A digital output generator generates a digital output based on the voltage ramp, the pixel voltages, and comparator output from an array of comparators that compare the voltage ramp to the pixel voltages. A return lookup table linearizes the digital output values.

African American Social Networking Online: Applying a Digital Practice Approach to Understanding Digital Inequalities

Directory of Open Access Journals (Sweden)

Danielle Taana Smith

2013-06-01

Full Text Available This study develops a framework for systematic examination of information and communication technologies (ICTs usage differences within a group. This framework situates the digital divide and digital inequalities model within a broader conceptual model of digital practice, exemplified by how groups of people use ICTs. I use nationally representative data to examine online activities on social networking sites (SNS for African Americans and other ethnoracial groups. The data for this research comes from the Pew Internet and American Life’s “Spring Tracking Survey 2008”. The results from regression analyses support the digital practice framework which moves discussions of ICT usage beyond social and economic advantages or disadvantages, and addresses individual and group needs in using these technologies.

Digital security technology simplified.

Science.gov (United States)

Scaglione, Bernard J

2007-01-01

Digital security technology is making great strides in replacing analog and other traditional security systems including CCTV card access, personal identification and alarm monitoring applications. Like any new technology, the author says, it is important to understand its benefits and limitations before purchasing and installing, to ensure its proper operation and effectiveness. This article is a primer for security directors on how digital technology works. It provides an understanding of the key components which make up the foundation for digital security systems, focusing on three key aspects of the digital security world: the security network, IP cameras and IP recorders.

A Mixed Analog-Digital Radiation Hard Technology for High Energy Physics Electronics: DMILL~(Durci~Mixte~sur~Isolant~Logico-Lineaire)

CERN Multimedia

Lugiez, F; Leray, J; Rouger, M; Fourches, N T; Musseau, O; Potheau, R

2002-01-01

%RD29 %title\\\\ \\\\Physics experiments under preparation with the future LHC require a fast, low noise, very rad-hard (>10 Mrad and >10$^{14}$ neutron/cm$^{2}$), mixed analog-digital microelectronics VLSI technology.\\\\ \\\\The DMILL microelectronics technology (RD29) was developed between 1990 and 1995 by a Consortium gathering the CEA and the firm Thomson-TCS, with the collaboration of IN2P3. The goal of the DMILL program, which is now completed, was to provide the High Energy Physics community, space industry, nuclear industry, and other applications, with an industrial very rad-hard mixed analog-digital microelectronics technology.\\\\ \\\\DMILL integrates mixed analog-digital very rad-hard (>10 Mrad and >10$^{14}$ neutron/cm$^{2}$) vertical bipolar, 0.8 $\\mu$m CMOS and 1.2 $\\mu$m PJFET transistors. Its SOI substrate and its dielectric trenches strongly reduce SEU sensitivity and completely eliminate any possibility of latch-up. Its four transistors are optimized to obtain low-noise features. DMILL also integrates...

Programs for control of an analog-signal switching network

International Nuclear Information System (INIS)

D'Ottavio, T.; Enriquez, R.; Katz, R.; Skelly, J.

1989-01-01

A suite of programs has been developed to control the network of analog-signal switching multiplexers in the AGS complex. The software is driven by a relational database which describes the architecture of the multiplexer tree and the set of available analog signals. Signals are routed through a three-layer multiplexer tree, to be made available at four consoles each with three 4-trace oscilloscopes. A menu-structured operator interface program is available at each console, to accept requests to route any available analog signal to any of that console's 12 oscilloscope traces. A common routing-server program provides automatic routing-server program provides automatic routing of requested signals through the layers of multiplexers, maintaining a reservation database to denote free and in-use trunks. Expansion of the analog signal system is easily accommodated in software by adding new signals, trunks, multiplexers, or consoles to the database. Programmatic control of the triggering signals for each of the oscilloscopes is also provided. 3 refs., 4 figs., 3 tabs

Multi-scale entropy analysis of VR-based analog-digital system of the operator mental workload

International Nuclear Information System (INIS)

Lee Chunyi; Hung Tamin; Sun Tienlung; Yang Chihwei; Cheng Tsungchieh; Yang Lichen

2011-01-01

In the past, serious accidents of nuclear power plant usually had relation with the negligence, error handling and wrong decisions of operators. Therefore, to understand and be able to measure mental workload levels of operators are significant for safety issues in the nuclear power plant, especially when operators face emergency conditions. Therefore, this study is to determine the physiological indicators to measure the operator in the task of mental workload. This paper was to use electrocardiogram (ECG) measurements, to collect the RR-Interval data; heart rate variability (HRV) to analysis the complexity of the operator. After importing the data to calculate heart rate variability of complexity analysis, it can help us to understand the operator for the analog-digital platform adaptation. The virtual analog-digital nuclear plant control room is built using a 3D game development tool called Unity3D. (author)

Eksplorasi Desain Dasar (Nirmana melalui Kombinasi Media Grafis Analog dan Digital: Suatu Penelitian Kelas/Studio

Directory of Open Access Journals (Sweden)

Anita Rahardja

2013-10-01

Full Text Available This article is based on a research aiming to contextualize the fundamental principles of art and design to current setting in which analog media are no longer chosen as the ultimate hardware/tools. It is important considering digital hardware becomes more and more prevalent even preferred by students, whereas analog tools are getting harder to obtain, expensive and less ecological friendly. The goal of this research is to produce method analysis and the creation of two-dimensional basic design through digital media (Camera followed by conventional drawing tools, documented and conducted by the lecturers and the students. So far, almost 100% of the studies concerning basic design could only be found in foreign publications, with visual work examples that cannot be used freely in Indonesian local education due to copyright issue. Therefore, a literature study is conducted to examine the formal objects of this research which are the elements and fundamental principles in design, followed by ideation and visualization processes carried by the students in basic design classes through the semester. The visualization itself will integrate analog and digital media to generate the material objects of the research, which is a series of two dimensional design compositions. These compositions are then analyzed and classified to taxonomic category of fundamental principles of two-dimensional design as an integral part of teaching-learning process (self-evaluation class for future improvement. 

Efficiency analysis on platform over the top (OTT) to deploy content and applications (edutainment) in digital television on optical network link

Science.gov (United States)

Puche, William S.; Sierra, Javier E.; Moreno, Gustavo A.

2014-08-01

The convergence of new technologies in the digital world has made devices with internet connectivity such as televisions, smatphone, Tablet, Blu-ray, game consoles, among others, to increase more and more. Therefore the major research centers are in the task of improving the network performance to mitigate the bottle neck phenomenon regarding capacity and high transmission rates in information and data. The implementation of standard HbbTV (Hybrid Broadcast Broadband TV), and technological platforms OTT (Over the Top), capable of distributing video, audio, TV, and other Internet services via devices connected directly to the cloud. Therefore a model to improve the transmission capacity required by content distribution networks (CDN) for online TV, with high-capacity optical networks is proposed.

Analog and mixed-signal electronics

CERN Document Server

Stephan, Karl

2015-01-01

A practical guide to analog and mixed-signal electronics, with an emphasis on design problems and applications This book provides an in-depth coverage of essential analog and mixed-signal topics such as power amplifiers, active filters, noise and dynamic range, analog-to-digital and digital-to-analog conversion techniques, phase-locked loops, and switching power supplies. Readers will learn the basics of linear systems, types of nonlinearities and their effects, op-amp circuits, the high-gain analog filter-amplifier, and signal generation. The author uses system design examples to motivate

Deep Cryogenic Low Power 24 Bits Analog to Digital Converter with Active Reverse Cryostat

Science.gov (United States)

Turqueti, Marcos; Prestemon, Soren; Albright, Robert

LBNL is developing an innovative data acquisition module for superconductive magnets where the front-end electronics and digitizer resides inside the cryostat. This electronic package allows conventional electronic technologies such as enhanced metal-oxide-semiconductor to work inside cryostats at temperatures as low as 4.2 K. This is achieved by careful management of heat inside the module that keeps the electronic envelop at approximately 85 K. This approach avoids all the difficulties that arise from changes in carrier mobility that occur in semiconductors at deep cryogenic temperatures. There are several advantages in utilizing this system. A significant reduction in electrical noise from signals captured inside the cryostat occurs due to the low temperature that the electronics is immersed in, reducing the thermal noise. The shorter distance that signals are transmitted before digitalization reduces pickup and cross-talk between channels. This improved performance in signal-to-noise rate by itself is a significant advantage. Another important advantage is the simplification of the feedthrough interface on the cryostat head. Data coming out of the cryostat is digital and serial, dramatically reducing the number of lines going through the cryostat feedthrough interface. It is important to notice that all lines coming out of the cryostat are digital and low voltage, reducing the possibility of electric breakdown inside the cryostat. This paper will explain in details the architecture and inner workings of this data acquisition system. It will also provide the performance of the analog to digital converter when the system is immersed in liquid helium, and in liquid nitrogen. Parameters such as power dissipation, integral non-linearity, effective number of bits, signal-to-noise and distortion, will be presented for both temperatures.

The mixed analog/digital shaper of the LHCb preshower

CERN Document Server

Lecoq, J; Cornat, R; Perret, P; Trouilleau, C

2001-01-01

The LHCb preshower signals show so many fluctuations at low energy that a classical shaping is not usable at all. Thanks to the fact that the fraction of the collected energy during a whole LHC beam crossing time is 85%, we studied the special solution we presented at Snowmass 1999 workshop. This solution consists of 2 interleaved fast integrators, one being in integrate mode when the other is digitally reset. Two track-and-hold systems and an analog multiplexer are used to give at the output 85% of the signal plus 15% of the previous one. These 15% are digitally computed from the previous sample, and subtracted. A completely new design of this solution had to be made. This new design is described, including new methods to decrease the supply voltage and the noise, as well as to increase the quality of the reset and the linearity. An output stage, consisting of an AB class push-pull using only NPN transistors is also described. Laboratory and beam test results are given. (5 refs).

Predicting cryptic links in host-parasite networks.

Directory of Open Access Journals (Sweden)

Tad Dallas

2017-05-01

Full Text Available Networks are a way to represent interactions among one (e.g., social networks or more (e.g., plant-pollinator networks classes of nodes. The ability to predict likely, but unobserved, interactions has generated a great deal of interest, and is sometimes referred to as the link prediction problem. However, most studies of link prediction have focused on social networks, and have assumed a completely censused network. In biological networks, it is unlikely that all interactions are censused, and ignoring incomplete detection of interactions may lead to biased or incorrect conclusions. Previous attempts to predict network interactions have relied on known properties of network structure, making the approach sensitive to observation errors. This is an obvious shortcoming, as networks are dynamic, and sometimes not well sampled, leading to incomplete detection of links. Here, we develop an algorithm to predict missing links based on conditional probability estimation and associated, node-level features. We validate this algorithm on simulated data, and then apply it to a desert small mammal host-parasite network. Our approach achieves high accuracy on simulated and observed data, providing a simple method to accurately predict missing links in networks without relying on prior knowledge about network structure.

Time-to-digital converters

CERN Document Server

Henzler, Stephan

2010-01-01

This text covers the fundamentals of time-to-digital converters on analog and digital conversion principles. It includes a theoretical investigation into quantization, linearity, noise and variability, and it details a range of advanced TDC architectures.

Reconfigurable signal processor designs for advanced digital array radar systems

Science.gov (United States)

Suarez, Hernan; Zhang, Yan (Rockee); Yu, Xining

2017-05-01

The new challenges originated from Digital Array Radar (DAR) demands a new generation of reconfigurable backend processor in the system. The new FPGA devices can support much higher speed, more bandwidth and processing capabilities for the need of digital Line Replaceable Unit (LRU). This study focuses on using the latest Altera and Xilinx devices in an adaptive beamforming processor. The field reprogrammable RF devices from Analog Devices are used as analog front end transceivers. Different from other existing Software-Defined Radio transceivers on the market, this processor is designed for distributed adaptive beamforming in a networked environment. The following aspects of the novel radar processor will be presented: (1) A new system-on-chip architecture based on Altera's devices and adaptive processing module, especially for the adaptive beamforming and pulse compression, will be introduced, (2) Successful implementation of generation 2 serial RapidIO data links on FPGA, which supports VITA-49 radio packet format for large distributed DAR processing. (3) Demonstration of the feasibility and capabilities of the processor in a Micro-TCA based, SRIO switching backplane to support multichannel beamforming in real-time. (4) Application of this processor in ongoing radar system development projects, including OU's dual-polarized digital array radar, the planned new cylindrical array radars, and future airborne radars.

Comparison of Response Characteristics of High-Purity Germanium Detectors using Analog Versus Digital Processing

International Nuclear Information System (INIS)

Luke, S J; Raschke, K

2004-01-01

In this article we will discuss some of the results of the response characteristics of High Purity germanium detectors using analog versus digital processing of the signals that are outputted from the detector. The discussion will focus on whether or not there is a significant difference in the response of the detector with digital electronics that it limits the ability of the detection system to get reasonable gamma ray spectrometric results. Particularly, whether or not the performance of the analysis code Pu600 is compromised

Cyber Threat and vulnerability Analysis for Digital Assets of NPPs

International Nuclear Information System (INIS)

Oh, Eun Se; Seo, In Yong; Kim, See Hong

2009-01-01

Today's computer and communication technology breakthrough make increase plant floor replacement from analog instrumentation and control systems of nuclear power plants to a full-fledged digital system . The rich functionality and crisp accuracy are one of big advantages of digital technology adaptation, but use of open networks and inherited shared system resources (memory, network, etc.) are well known weak points of digital system. Intended or un-intended cyber attack throughout power plant digital control system's weak point may result to wide area of system failures and that easily defeats system operation and multiple protection safeguards. Well organized cyber security analysis for nuclear plant digital control systems (digital assets) are required

Digital Social Network Mining for Topic Discovery

Science.gov (United States)

Moradianzadeh, Pooya; Mohi, Maryam; Sadighi Moshkenani, Mohsen

Networked computers are expanding more and more around the world, and digital social networks becoming of great importance for many people's work and leisure. This paper mainly focused on discovering the topic of exchanging information in digital social network. In brief, our method is to use a hierarchical dictionary of related topics and words that mapped to a graph. Then, with comparing the extracted keywords from the context of social network with graph nodes, probability of relation between context and desired topics will be computed. This model can be used in many applications such as advertising, viral marketing and high-risk group detection.

Efficiency and hardware comparison of analog control-based and digital control-based 70 W two-stage power factor corrector and DC-DC converters

DEFF Research Database (Denmark)

Török, Lajos; Munk-Nielsen, Stig

2011-01-01

A comparison of an analog and a digital controller driven 70 W two-stage power factor corrector converter is presented. Both controllers are operated in average current-mode-control for the PFC and peak current control for the DC-DC converter. Digital controller design and converter modeling...... is described. Results show that digital control can compete with the analog one in efficiency, PFC and THD....

Active pixel sensor having intra-pixel charge transfer with analog-to-digital converter

Science.gov (United States)

Fossum, Eric R. (Inventor); Mendis, Sunetra K. (Inventor); Pain, Bedabrata (Inventor); Nixon, Robert H. (Inventor); Zhou, Zhimin (Inventor)

2003-01-01

An imaging device formed as a monolithic complementary metal oxide semiconductor integrated circuit in an industry standard complementary metal oxide semiconductor process, the integrated circuit including a focal plane array of pixel cells, each one of the cells including a photogate overlying the substrate for accumulating photo-generated charge in an underlying portion of the substrate, a readout circuit including at least an output field effect transistor formed in the substrate, and a charge coupled device section formed on the substrate adjacent the photogate having a sensing node connected to the output transistor and at least one charge coupled device stage for transferring charge from the underlying portion of the substrate to the sensing node and an analog-to-digital converter formed in the substrate connected to the output of the readout circuit.

Analog Design for Digital Deployment of a Serious Leadership Game

Science.gov (United States)

Maxwell, Nicholas; Lang, Tristan; Herman, Jeffrey L.; Phares, Richard

2012-01-01

This paper presents the design, development, and user testing of a leadership development simulation. The authors share lessons learned from using a design process for a board game to allow for quick and inexpensive revision cycles during the development of a serious leadership development game. The goal of this leadership simulation is to accelerate the development of leadership capacity in high-potential mid-level managers (GS-15 level) in a federal government agency. Simulation design included a mixed-method needs analysis, using both quantitative and qualitative approaches to determine organizational leadership needs. Eight design iterations were conducted, including three user testing phases. Three re-design iterations followed initial development, enabling game testing as part of comprehensive instructional events. Subsequent design, development and testing processes targeted digital application to a computer- and tablet-based environment. Recommendations include pros and cons of development and learner testing of an initial analog simulation prior to full digital simulation development.

Effect of various features on the life cycle cost of the timing/synchronization subsystem of the DCS digital communications network

Science.gov (United States)

Kimsey, D. B.

1978-01-01

The effect on the life cycle cost of the timing subsystem was examined, when these optional features were included in various combinations. The features included mutual control, directed control, double-ended reference links, independence of clock error measurement and correction, phase reference combining, self-organization, smoothing for link and nodal dropouts, unequal reference weightings, and a master in a mutual control network. An overall design of a microprocessor-based timing subsystem was formulated. The microprocessor (8080) implements the digital filter portion of a digital phase locked loop, as well as other control functions such as organization of the network through communication with processors at neighboring nodes.

10-bit rapid single flux quantum digital-to-analog converter for ac voltage standard

International Nuclear Information System (INIS)

Maezawa, M; Hirayama, F

2008-01-01

Digital-to-analog (D/A) converters based on rapid single flux quantum (RSFQ) technology are under development for ac voltage standard applications. We present design and test results on a prototype 10-bit version integrated on a single chip. The 10-bit chip includes over 6000 Josephson junctions and consumes a bias current exceeding 1 A. To reduce the effects of the high bias current on circuit operation, a custom design method was employed in part and large circuit blocks were divided into smaller ones. The 10-bit chips were fabricated and tested at low speed. The test results suggested that our design approach could manage large bias currents on the order of 1 A per chip

Is the link from working memory to analogy causal? No analogy improvements following working memory training gains.

Directory of Open Access Journals (Sweden)

J Elizabeth Richey

Full Text Available Analogical reasoning has been hypothesized to critically depend upon working memory through correlational data, but less work has tested this relationship through experimental manipulation. An opportunity for examining the connection between working memory and analogical reasoning has emerged from the growing, although somewhat controversial, body of literature suggests complex working memory training can sometimes lead to working memory improvements that transfer to novel working memory tasks. This study investigated whether working memory improvements, if replicated, would increase analogical reasoning ability. We assessed participants' performance on verbal and visual analogy tasks after a complex working memory training program incorporating verbal and spatial tasks. Participants' improvements on the working memory training tasks transferred to other short-term and working memory tasks, supporting the possibility of broad effects of working memory training. However, we found no effects on analogical reasoning. We propose several possible explanations for the lack of an impact of working memory improvements on analogical reasoning.

Is the link from working memory to analogy causal? No analogy improvements following working memory training gains.

Science.gov (United States)

Richey, J Elizabeth; Phillips, Jeffrey S; Schunn, Christian D; Schneider, Walter

2014-01-01

Analogical reasoning has been hypothesized to critically depend upon working memory through correlational data, but less work has tested this relationship through experimental manipulation. An opportunity for examining the connection between working memory and analogical reasoning has emerged from the growing, although somewhat controversial, body of literature suggests complex working memory training can sometimes lead to working memory improvements that transfer to novel working memory tasks. This study investigated whether working memory improvements, if replicated, would increase analogical reasoning ability. We assessed participants' performance on verbal and visual analogy tasks after a complex working memory training program incorporating verbal and spatial tasks. Participants' improvements on the working memory training tasks transferred to other short-term and working memory tasks, supporting the possibility of broad effects of working memory training. However, we found no effects on analogical reasoning. We propose several possible explanations for the lack of an impact of working memory improvements on analogical reasoning.

Is the Link from Working Memory to Analogy Causal? No Analogy Improvements following Working Memory Training Gains

Science.gov (United States)

Richey, J. Elizabeth; Phillips, Jeffrey S.; Schunn, Christian D.; Schneider, Walter

2014-01-01

Analogical reasoning has been hypothesized to critically depend upon working memory through correlational data [1], but less work has tested this relationship through experimental manipulation [2]. An opportunity for examining the connection between working memory and analogical reasoning has emerged from the growing, although somewhat controversial, body of literature suggests complex working memory training can sometimes lead to working memory improvements that transfer to novel working memory tasks. This study investigated whether working memory improvements, if replicated, would increase analogical reasoning ability. We assessed participants’ performance on verbal and visual analogy tasks after a complex working memory training program incorporating verbal and spatial tasks [3], [4]. Participants’ improvements on the working memory training tasks transferred to other short-term and working memory tasks, supporting the possibility of broad effects of working memory training. However, we found no effects on analogical reasoning. We propose several possible explanations for the lack of an impact of working memory improvements on analogical reasoning. PMID:25188356

PHOTO ENCODING OF ANALOG WATER METER FOR USER ACCESS AND PAYMENT SYSTEM

OpenAIRE

GODFREY A. MILLS; MOSES A. ACQUAH; APPAH BREMANG

2012-01-01

This paper presents design reconfiguration of analog water meter to provide remote access to user water consumption and billing records, payments, and meter device monitoring using photo-encoding as the detecting method for water consumption, a PIC18F2423 microcontroller for data processing, and SMS (short message service) technology for data transportation. To validate the system design, an analog water meter was converted into a digital equivalent and interfaced to the cellular network to t...

Applications of deep convolutional neural networks to digitized natural history collections

Directory of Open Access Journals (Sweden)

Eric Schuettpelz

2017-11-01

Full Text Available Natural history collections contain data that are critical for many scientific endeavors. Recent efforts in mass digitization are generating large datasets from these collections that can provide unprecedented insight. Here, we present examples of how deep convolutional neural networks can be applied in analyses of imaged herbarium specimens. We first demonstrate that a convolutional neural network can detect mercury-stained specimens across a collection with 90% accuracy. We then show that such a network can correctly distinguish two morphologically similar plant families 96% of the time. Discarding the most challenging specimen images increases accuracy to 94% and 99%, respectively. These results highlight the importance of mass digitization and deep learning approaches and reveal how they can together deliver powerful new investigative tools.

Applications of deep convolutional neural networks to digitized natural history collections.

Science.gov (United States)

Schuettpelz, Eric; Frandsen, Paul B; Dikow, Rebecca B; Brown, Abel; Orli, Sylvia; Peters, Melinda; Metallo, Adam; Funk, Vicki A; Dorr, Laurence J

2017-01-01

Natural history collections contain data that are critical for many scientific endeavors. Recent efforts in mass digitization are generating large datasets from these collections that can provide unprecedented insight. Here, we present examples of how deep convolutional neural networks can be applied in analyses of imaged herbarium specimens. We first demonstrate that a convolutional neural network can detect mercury-stained specimens across a collection with 90% accuracy. We then show that such a network can correctly distinguish two morphologically similar plant families 96% of the time. Discarding the most challenging specimen images increases accuracy to 94% and 99%, respectively. These results highlight the importance of mass digitization and deep learning approaches and reveal how they can together deliver powerful new investigative tools.

Porous Cross-Linked Polyimide-Urea Networks

Science.gov (United States)

Meador, Mary Ann B. (Inventor); Nguyen, Baochau N. (Inventor)

2015-01-01

Porous cross-linked polyimide-urea networks are provided. The networks comprise a subunit comprising two anhydride end-capped polyamic acid oligomers in direct connection via a urea linkage. The oligomers (a) each comprise a repeating unit of a dianhydride and a diamine and a terminal anhydride group and (b) are formulated with 2 to 15 of the repeating units. The subunit was formed by reaction of the diamine and a diisocyanate to form a diamine-urea linkage-diamine group, followed by reaction of the diamine-urea linkage-diamine group with the dianhydride and the diamine to form the subunit. The subunit has been cross-linked via a cross-linking agent, comprising three or more amine groups, at a balanced stoichiometry of the amine groups to the terminal anhydride groups. The subunit has been chemically imidized to yield the porous cross-linked polyimide-urea network. Also provided are wet gels, aerogels, and thin films comprising the networks, and methods of making the networks.

Chronopolis Digital Preservation Network

Directory of Open Access Journals (Sweden)

David Minor

2010-07-01

Full Text Available The Chronopolis Digital Preservation Initiative, one of the Library of Congress’ latest efforts to collect and preserve at-risk digital information, has completed its first year of service as a multi-member partnership to meet the archival needs of a wide range of domains.Chronopolis is a digital preservation data grid framework developed by the San Diego Supercomputer Center (SDSC at UC San Diego, the UC San Diego Libraries (UCSDL, and their partners at the National Center for Atmospheric Research (NCAR in Colorado and the University of Maryland's Institute for Advanced Computer Studies (UMIACS.Chronopolis addresses a critical problem by providing a comprehensive model for the cyberinfrastructure of collection management, in which preserved intellectual capital is easily accessible, and research results, education material, and new knowledge can be incorporated smoothly over the long term. Integrating digital library, data grid, and persistent archive technologies, Chronopolis has created trusted environments that span academic institutions and research projects, with the goal of long-term digital preservation.A key goal of the Chronopolis project is to provide cross-domain collection sharing for long-term preservation. Using existing high-speed educational and research networks and mass-scale storage infrastructure investments, the partnership is leveraging the data storage capabilities at SDSC, NCAR, and UMIACS to provide a preservation data grid that emphasizes heterogeneous and highly redundant data storage systems.In this paper we will explore the major themes within Chronopolis, including:a The philosophy and theory behind a nationally federated data grid for preservation. b The core tools and technologies used in Chronopolis. c The metadata schema that is being developed within Chronopolis for all of the data elements. d Lessons learned from the first year of the project.e Next steps in digital preservation using Chronopolis: how we

A comprehensive comparison of network similarities for link prediction and spurious link elimination

Science.gov (United States)

Zhang, Peng; Qiu, Dan; Zeng, An; Xiao, Jinghua

2018-06-01

Identifying missing interactions in complex networks, known as link prediction, is realized by estimating the likelihood of the existence of a link between two nodes according to the observed links and nodes' attributes. Similar approaches have also been employed to identify and remove spurious links in networks which is crucial for improving the reliability of network data. In network science, the likelihood for two nodes having a connection strongly depends on their structural similarity. The key to address these two problems thus becomes how to objectively measure the similarity between nodes in networks. In the literature, numerous network similarity metrics have been proposed and their accuracy has been discussed independently in previous works. In this paper, we systematically compare the accuracy of 18 similarity metrics in both link prediction and spurious link elimination when the observed networks are very sparse or consist of inaccurate linking information. Interestingly, some methods have high prediction accuracy, they tend to perform low accuracy in identification spurious interaction. We further find that methods can be classified into several cluster according to their behaviors. This work is useful for guiding future use of these similarity metrics for different purposes.

On the comparison of analog and digital SiPM readout in terms of expected timing performance

International Nuclear Information System (INIS)

Gundacker, S.; Auffray, E.; Jarron, P.; Meyer, T.; Lecoq, P.

2015-01-01

In time of flight positron emission tomography (TOF-PET) and in particular for the EndoTOFPET-US Project (Frisch, 2013 [1]), and other applications for high energy physics, the multi-digital silicon photomultiplier (MD-SiPM) was recently proposed (Mandai and Charbon, 2012 [2]), in which the time of every single photoelectron is being recorded. If such a photodetector is coupled to a scintillator, the largest and most accurate timing information can be extracted from the cascade of the scintillation photons, and the most probable time of positron emission determined. The readout concept of the MD-SiPM is very different from that of the analog SiPM, where the individual photoelectrons are merely summed up and the output signal fed into the readout electronics. We have developed a comprehensive Monte Carlo (MC) simulation tool that describes the timing properties of the photodetector and electronics, the scintillation properties of the crystal and the light transfer within the crystal. In previous studies we have compared MC simulations with coincidence time resolution (CTR) measurements and found good agreement within less than 10% for crystals of different lengths (from 3 mm to 20 mm) coupled to SiPMs from Hamamatsu. In this work we will use the developed MC tool to directly compare the highest possible time resolution for both the analog and digital readout of SiPMs with different scintillator lengths. The presented studies reveal that the analog readout of SiPMs with microcell signal pile-up and leading edge discrimination can lead to nearly the same time resolution as compared to the maximum likelihood time estimation applied to MD-SiPMs. Consequently there is no real preference for either a digital or analog SiPM for the sake of achieving highest time resolution. However, the best CTR in the analog SiPM is observed for a rather small range of optimal threshold values, whereas the MD-SiPM provides stable CTR after roughly 20 registered photoelectron timestamps in

Connect high speed analog-digital converter with EPICS based on LabVIEW

International Nuclear Information System (INIS)

Wang Wei; Chi Yunlong

2008-01-01

This paper introduce a method to connect high speed analog-digital converter (ADC212/100) with EPICS on Windows platform using LabVIEW. We use labVIEW to communicate with the converter, then use interface sub-VIs between LabVIEW and EPICS to access the EPICS IOC by Channel Access (CA). For the easy use graph programming language of LabVIEW, this method could shorten the develop period and reduce manpower cost. (authors)

Rational design of functional and tunable oscillating enzymatic networks

Science.gov (United States)

Semenov, Sergey N.; Wong, Albert S. Y.; van der Made, R. Martijn; Postma, Sjoerd G. J.; Groen, Joost; van Roekel, Hendrik W. H.; de Greef, Tom F. A.; Huck, Wilhelm T. S.

2015-02-01

Life is sustained by complex systems operating far from equilibrium and consisting of a multitude of enzymatic reaction networks. The operating principles of biology's regulatory networks are known, but the in vitro assembly of out-of-equilibrium enzymatic reaction networks has proved challenging, limiting the development of synthetic systems showing autonomous behaviour. Here, we present a strategy for the rational design of programmable functional reaction networks that exhibit dynamic behaviour. We demonstrate that a network built around autoactivation and delayed negative feedback of the enzyme trypsin is capable of producing sustained oscillating concentrations of active trypsin for over 65 h. Other functions, such as amplification, analog-to-digital conversion and periodic control over equilibrium systems, are obtained by linking multiple network modules in microfluidic flow reactors. The methodology developed here provides a general framework to construct dissipative, tunable and robust (bio)chemical reaction networks.

Miniaturized wireless sensor network

OpenAIRE

Lecointre , Aubin; Dragomirescu , Daniela; Dubuc , David; Grenier , Katia; Pons , Patrick; Aubert , Hervé; Müller , A.; Berthou , Pascal; Gayraud , Thierry; Plana , Robert

2006-01-01

This paper addresses an overview of the wireless sensor networks. It is shown that MEMS/NEMS technologies and SIP concept are well suited for advanced architectures. It is also shown analog architectures have to be compatible with digital signal techniques to develop smart network of microsystem.

A full digital approach to the TDCR method

International Nuclear Information System (INIS)

Mini, Giuliano; Pepe, Francesco; Tintori, Carlo; Capogni, Marco

2014-01-01

Current state of the art solutions based on the Triple to Double Coincidence Ratio method are generally large size, heavy-weight and not transportable systems. This is due, on one side, to large detectors and scintillation chambers and, on the other, to bulky analog electronics for data acquisition. CAEN developed a new, full digital approach to TDCR technique based on a portable, stand-alone, high-speed multichannel digitizer, on-board Digital Pulse Processing and dedicated DAQ software that emulates the well-known MAC3 analog board. - Highlights: • CAEN Desktop Digitizers used to emulate the MAC3 analog board in TDCR acquisition. • Spectroscopic application of the CAEN digitizers to the TDCR for charge spectra. • Development of two different softwares by CAEN and ENEA-INMRI for TDCR analysis. • Single electron peak obtained by CAEN digitizer and ENEA-INMRI portable TDCR. • Measurements of 90 Sr/ 90 Y by the new TDCR device equipped with CAEN digitizers

Optoelectronic link for analog signals from solid state detectors in high energy physics

International Nuclear Information System (INIS)

Manfredi, P.F.; Speziali, V.

1983-01-01

An optoelectric link has been made to transmit analog signals over a long distance between the beam area and the remote-end data acquisition instrumentation in high energy experiments. The optoelectronic link is intended for silicon target applications and it is designed to work on the signals at the output of a low noise amplifier system. Its advantages over a conventional galvanic connection as well as its limitations are discussed. (orig.)

Design of integrated all optical digital to analog converter (DAC) using 2D photonic crystals

Science.gov (United States)

Moniem, Tamer A.; El-Din, Eman S.

2017-11-01

A novel design of all optical 3 bit digital to analog (DAC) converter will be presented in this paper based on 2 Dimension photonic crystals (PhC). The proposed structure is based on the photonic crystal ring resonators (PCRR) with combining the nonlinear Kerr effect on the PCRR. The total size of the proposed optical 3 bit DAC is equal to 44 μm × 37 μm of 2D square lattice photonic crystals of silicon rods with refractive index equal to 3.4. The finite different time domain (FDTD) and Plane Wave Expansion (PWE) methods are used to back the overall operation of the proposed optical DAC.

A novel modulation scheme for noise reduction in analog fiber optic links

NARCIS (Netherlands)

Marpaung, D.A.I.; Roeloffzen, C.G.H.; van Etten, Wim; Megret, P.; Wuilpart, M.; Bette, S.; Staquet, N.

2005-01-01

A novel balanced modulation and detection scheme for analog fiber optic links is proposed to overcome the limitations in signal-to-noise ratio (SNR) and dynamic range (DR).In this scheme, the modulating signal is split into positive and negative halves and applied to a pair of laser diodes. Both

Cheating and Feeling Honest: Committing and Punishing Analog versus Digital Academic Dishonesty Behaviors in Higher Education

Directory of Open Access Journals (Sweden)

Adi Friedman

2016-12-01

Full Text Available This study examined the phenomenon of academic dishonesty among university students. It was based on Pavela’s (1997 framework of types of academic dishonesty (cheating, plagiarism, fabrication, and facilitation and distinguished between digital and “traditional”- analog dishonesty. The study analyzed cases of academic dishonesty offenses committed by students, as well as the reasons for academic dishonesty behaviors, and the severity of penalties for violations of academic integrity. The motivational framework for committing an act of academic dishonesty (Murdock & Anderman, 2006 and the Self-Concept Maintenance model (Mazar, Amir, & Ariely, 2008 were employed to analyze the reasons for students’ dishonest behaviors. We analyzed 315 protocols of the Disciplinary Committee, at The Open University of Israel, from 2012-2013 that represent all of the offenses examined by the Committee during one and a half years. The findings showed that analog dishonesty was more prevalent than digital dishonesty. According to the students, the most prevalent reason for their academic dishonesty was the need to maintain a positive view of self as an honest person despite violating ethical codes. Interestingly, penalties for analog dishonesty were found to be more severe than those imposed for digital dishonesty. Surprisingly, women were penalized more severely than men, despite no significant gender differences in dishonesty types or in any other parameter explored in the study. Findings of this study shed light on the scope and roots of academic dishonesty and may assist institutions in coping effectively with this phenomenon.

Cyber Threat and vulnerability Analysis for Digital Assets of NPPs

Energy Technology Data Exchange (ETDEWEB)

Oh, Eun Se; Seo, In Yong [Korea Electric Power research Institute, Daejeon (Korea, Republic of); Kim, See Hong [Korea Hydro and Nuclear Power Co., Seoul (Korea, Republic of)

2009-10-15

Today's computer and communication technology breakthrough make increase plant floor replacement from analog instrumentation and control systems of nuclear power plants to a full-fledged digital system . The rich functionality and crisp accuracy are one of big advantages of digital technology adaptation, but use of open networks and inherited shared system resources (memory, network, etc.) are well known weak points of digital system. Intended or un-intended cyber attack throughout power plant digital control system's weak point may result to wide area of system failures and that easily defeats system operation and multiple protection safeguards. Well organized cyber security analysis for nuclear plant digital control systems (digital assets) are required.

Documentary Realism, Sampling Theory and Peircean Semiotics: electronic audiovisual signs (analog or digital as indexes of reality

Directory of Open Access Journals (Sweden)

Hélio Godoy

2007-07-01

Full Text Available This paper addresses Documentary Realism, focusing on thephysical phenomena of transduction that take place in analog and digital audiovisual systems, herein analyzed in the light of the Sampling Theory, within the framework of Shannon and Weaver’s Information Theory. Transduction is a process by which one type of energy is transformed into another, or by which information is transcodified. Within the scope of Documentary Realism, it cannotbe claimed that electronic audiovisual signs, because of their technical digital features lead to a rupture with reality. Rather, the digital documentary, based on electronic digital cinematography, is still an index of reality.

A link prediction method for heterogeneous networks based on BP neural network

Science.gov (United States)

Li, Ji-chao; Zhao, Dan-ling; Ge, Bing-Feng; Yang, Ke-Wei; Chen, Ying-Wu

2018-04-01

Most real-world systems, composed of different types of objects connected via many interconnections, can be abstracted as various complex heterogeneous networks. Link prediction for heterogeneous networks is of great significance for mining missing links and reconfiguring networks according to observed information, with considerable applications in, for example, friend and location recommendations and disease-gene candidate detection. In this paper, we put forward a novel integrated framework, called MPBP (Meta-Path feature-based BP neural network model), to predict multiple types of links for heterogeneous networks. More specifically, the concept of meta-path is introduced, followed by the extraction of meta-path features for heterogeneous networks. Next, based on the extracted meta-path features, a supervised link prediction model is built with a three-layer BP neural network. Then, the solution algorithm of the proposed link prediction model is put forward to obtain predicted results by iteratively training the network. Last, numerical experiments on the dataset of examples of a gene-disease network and a combat network are conducted to verify the effectiveness and feasibility of the proposed MPBP. It shows that the MPBP with very good performance is superior to the baseline methods.

Investigations of Polarization Dependent Loss in Polarization Modulated Analog Optical Links

Science.gov (United States)

2015-12-29

performance analog optical links for military applications primarily rely on the most common link architecture employing intensity modulation with...axis as bisector of DD and Ss•) PP = fl i p ( rr, PPO] ; (• flip the P vector imaqe on the PA •) PPh a t = unit[PP ) ; PHI = ArcCos [ PPha t .unit...DD ) ); AA = ((Cos ( PHI / 2])𔃼 • t p (Sin [ PHI / 2 ])𔃼 ) PP • tpDDhat / 2 ; CC2 =- ( MM · AA . SS • (AA . I!M) (I!M. SS)) ; CC3 = AA . SS; ln

A Survey of Congestion Control Techniques and Data Link Protocols in Satellite Networks

OpenAIRE

Fahmy, Sonia; Jain, Raj; Lu, Fang; Kalyanaraman, Shivkumar

1998-01-01

Satellite communication systems are the means of realizing a global broadband integrated services digital network. Due to the statistical nature of the integrated services traffic, the resulting rate fluctuations and burstiness render congestion control a complicated, yet indispensable function. The long propagation delay of the earth-satellite link further imposes severe demands and constraints on the congestion control schemes, as well as the media access control techniques and retransmissi...

Linking Environmental Orientation to Start-ups’ Networking Activities

DEFF Research Database (Denmark)

Dickel, Petra; Ritter, Thomas

Besides for-profit start-ups, an increasing number of firms start their existence with the purpose to “do good” for society – mirrored in an increasing academic discussion of sustainable firms. Yet, there is little research on the networking activities of start-ups that do not have profit...... generation as their primary focus. Addressing this research gap, we develop hypotheses on the different networking activities of environmentally oriented start-ups arguing that their societal focus has a positive impact on the frequency of their networking and the size of their network. For empirically...... investigating such networking differences, we use data from 179 technology-based start-ups and show that start-ups with a strong external environmental orientation have significantly higher networking frequency and build larger networks. On the contrary, strong internal environmental orientation is linked...

Environmental tests of a digital safety channel: An investigation of stress-related vulnerabilities of computer-based safety system

International Nuclear Information System (INIS)

Korsah, K.; Wilson, T.L.; Wood, R.; Tanaka, T.

1997-01-01

This article presents the results of environmental stress tests performed on an experimental digital safety channel (EDSC) assembled at the Oak Ridge National Laboratory as part of the Qualification of Advanced Instrumentation and Controls Systems Research program, which was sponsored by the US Nuclear Regulatory Commission. The program is expected to provide recommendations for environmental qualification of digital safety systems. The purpose of the study was to investigate potential vulnerabilities of distributed computer systems used in safety applications when subjected to environmental stressors. The EDSC assembled for the tests employs technologies and digital subsystems representative of those proposed for use in advanced light-water reactors or as retrofits in existing plants. Subsystems include computers, electrical and optical serial communication links, fiber-optic network links, analog-to-digital and digital-to-analog converters, and multiplexers. The EDSC was subjected to selected stressors that are a potential risk to digital equipment in a mild environment. The selected stressors were electromagnetic and radiofrequency interferences (EMI-RFI), temperature, humidity, and smoke exposure. The stressors were applied at levels of intensity considerably higher than the safety channel is likely to experience in a normal nuclear power plant environment. Ranges of stress were selected at a sufficiently high level to induce errors so that failure modes that are characteristic of the technologies employed could be identified. On the basis of the incidence of functional errors observed during testing, EMI-RFI, smoke exposure, and high temperature coupled with high relative humidity, in that order, were found to have the greatest impact of the stressors investigated. The most prevalent stressor-induced upsets, as well as the most severe, were found to occur during the EMI-RFI tests

Analog lightwave links for detector front-ends at the LHC

International Nuclear Information System (INIS)

Baird, A.; Dowell, J.; Duthie, P.

1995-01-01

Lightwave links are being developed for volume application in the transfer of analog signals from the tracking detector front-ends to the readout electronics. The links are based on electro-optic intensity modulators which are mounted on detectors and connected by optical fibers to remotely located transceivers (lasers and photoreceivers). The modulators are 3--5 semiconductor reflective devices based on multi-quantum well structures. The transceivers will be integrated devices of a novel design. Modulator prototypes have been fabricated and tested. Neutron and γ-ray irradiation studies have been performed on modulators and fibers. The main results achieved so far are reported and key system issues are reviewed. This work is part of the CERN DRDC project RD23 project RD23

Using Visual Analogies To Teach Introductory Statistical Concepts

Directory of Open Access Journals (Sweden)

Jessica S. Ancker

2017-07-01

Full Text Available Introductory statistical concepts are some of the most challenging to convey in quantitative literacy courses. Analogies supplemented by visual illustrations can be highly effective teaching tools. This literature review shows that to exploit the power of analogies, teachers must select analogies familiar to the audience, explicitly link the analog with the target concept, and avert misconceptions by explaining where the analogy fails. We provide guidance for instructors and a series of visual analogies for use in teaching medical and health statistics.

LDRD final report: photonic analog-to-digital converter (ADC) technology; TOPICAL

International Nuclear Information System (INIS)

Bowers, M; Deri, B; Haigh, R; Lowry, M; Sargis, P; Stafford, R; Tong, T

1999-01-01

We report on an LDRD seed program of novel technology development (started by an FY98 Engineering Tech-base project) that will enable extremely high-fidelity analog-to-digital converters for a variety of national security missions. High speed (l0+ GS/s ), high precision (l0+ bits) ADC technology requires extremely short aperture times ((approx)1ps ) with very low jitter requirements (sub 10fs ). These fundamental requirements, along with other technological barriers, are difficult to realize with electronics: However, we outline here, a way to achieve these timing apertures using a novel multi-wavelength optoelectronic short-pulse optical source. Our approach uses an optoelectronic feedback scheme with high optical Q to produce an optical pulse train with ultra-low jitter ( sub 5fs) and high amplitude stability ( and lt;10(sup 10)). This approach requires low power and can be integrated into an optoelectronic integrated circuit to minimize the size. Under this seed program we have demonstrated that the optical feedback mechanism can be used to generate a high Q resonator. This has reduced the technical risk for further development, making it an attractive candidate for outside funding

Link prediction in multiplex online social networks

Science.gov (United States)

Jalili, Mahdi; Orouskhani, Yasin; Asgari, Milad; Alipourfard, Nazanin; Perc, Matjaž

2017-02-01

Online social networks play a major role in modern societies, and they have shaped the way social relationships evolve. Link prediction in social networks has many potential applications such as recommending new items to users, friendship suggestion and discovering spurious connections. Many real social networks evolve the connections in multiple layers (e.g. multiple social networking platforms). In this article, we study the link prediction problem in multiplex networks. As an example, we consider a multiplex network of Twitter (as a microblogging service) and Foursquare (as a location-based social network). We consider social networks of the same users in these two platforms and develop a meta-path-based algorithm for predicting the links. The connectivity information of the two layers is used to predict the links in Foursquare network. Three classical classifiers (naive Bayes, support vector machines (SVM) and K-nearest neighbour) are used for the classification task. Although the networks are not highly correlated in the layers, our experiments show that including the cross-layer information significantly improves the prediction performance. The SVM classifier results in the best performance with an average accuracy of 89%.

Experimental investigation of analog and digital dimming techniques on photometric performance of an indoor Visible Light Communication (VLC) system

Science.gov (United States)

Zafar, Fahad; Kalavally, Vineetha; Bakaul, Masuduzzaman; Parthiban, R.

2015-09-01

For making commercial implementation of light emitting diode (LED) based visible light communication (VLC) systems feasible, it is necessary to incorporate it with dimming schemes which will provide energy savings, moods and increase the aesthetic value of the places using this technology. There are two general methods which are used to dim LEDs commonly categorized as analog and digital dimming. Incorporating fast data transmission with these techniques is a key challenge in VLC. In this paper, digital and analog dimming for a 10 Mb/s non return to zero on-off keying (NRZ-OOK) based VLC system is experimentally investigated considering both photometric and communicative parameters. A spectrophotometer was used for photometric analysis and a line of sight (LOS) configuration in the presence of ambient light was used for analyzing communication parameters. Based on the experimental results, it was determined that digital dimming scheme is preferable for use in indoor VLC systems requiring high dimming precision and data transmission at lower brightness levels. On the other hand, analog dimming scheme is a cost effective solution for high speed systems where dimming precision is insignificant.

Analog neural networks in an upgraded muon trigger for the DZero detector

International Nuclear Information System (INIS)

Fortner, M.R.

1992-04-01

The use of analog neural networks as part of the DZero muon detector is considered. A study was made of tracking through a single muon chamber using neural network techniques. A hardware application based on Intel's ETANN ship was designed and used in a test beam at Fermi National Accelerator Laboratory. Plans to implement a neural network trigger in DZero are also discussed

Design and Simulation of Seido Buffer for Analog to Digital Converter (ADC) on Multichannel Analyzer (MCA) Application

International Nuclear Information System (INIS)

Harzawadi Hasim; Maslina Ibrahim; Nolida Yusop; Mohd Ashhar Khalid

2011-01-01

Most of our electronic equipment has buffer, thus this make buffer as one of importance in electronic gadget. This paper introduced Single Ended Input Differential Output (SEIDO) buffer to predict the bias at approximately 2.5 V. For this purpose, the input range between -1 mV to 4 V was implemented. The software used to cascade SEIDO buffer is called LTspice IV; an open source software developed by Linear Technology Incorporation. The component involve in this development was Operational Amplifier (OP AMP) AD826 from Analog Devices Incorporation, capacitor and resistor. Kirchhoffs Current Law and Kirchhoffs Voltage Law was applied to calculated voltage gain and biasing voltage. All design has been verified by LTspice IV. The result produced from simulation was between -0.3 V to 6.3 V with bias roughly at 2.5 V. These results prove that it was capable to drive Analog Digital Converter (ADC) that can subsequently apply for Multichannel Analyzer (MCA). (author)

Utility-Based Link Recommendation in Social Networks

Science.gov (United States)

Li, Zhepeng

2013-01-01

Link recommendation, which suggests links to connect currently unlinked users, is a key functionality offered by major online social networking platforms. Salient examples of link recommendation include "people you may know"' on Facebook and "who to follow" on Twitter. A social networking platform has two types of stakeholder:…

Time concurrency/phase-time synchronization in digital communications networks

Science.gov (United States)

Kihara, Masami; Imaoka, Atsushi

1990-01-01

Digital communications networks have the intrinsic capability of time synchronization which makes it possible for networks to supply time signals to some applications and services. A practical estimation method for the time concurrency on terrestrial networks is presented. By using this method, time concurrency capability of the Nippon Telegraph and Telephone Corporation (NTT) digital communications network is estimated to be better than 300 ns rms at an advanced level, and 20 ns rms at final level.

Embedded calibration system for the DIII-D Langmuir probe analog fiber optic links

International Nuclear Information System (INIS)

Watkins, J. G.; Rajpal, R.; Mandaliya, H.; Watkins, M.; Boivin, R. L.

2012-01-01

This paper describes a generally applicable technique for simultaneously measuring offset and gain of 64 analog fiber optic data links used for the DIII-D fixed Langmuir probes by embedding a reference voltage waveform in the optical transmitted signal before every tokamak shot. The calibrated data channels allow calibration of the power supply control fiber optic links as well. The array of fiber optic links and the embedded calibration system described here makes possible the use of superior modern data acquisition electronics in the control room.

An Interfacing System for Radiation Surveillance Using a Radio Communication Network

International Nuclear Information System (INIS)

Arunsiri, T.; Punnachaiya, S.; Pattarasumun, A.

1998-01-01

The development of an interfacing system for environmental radiation surveillance using radio communication network is aimed to improve a way by which environmental radiation measurement is transmitted and reported from the regional area monitoring station network. This also includes an automatic warning of beacon status via the radio link network to the center of environmental radiation control when an abnormal radiation level is detected. The interfacing system was developed by simulating the EGAT radio link network, the NT 2612, and can be separated into two parts. The first part was for a mobile station which can manage the output data from the radiation measurement system in the standard form of RS-232, IEEE-488, BCD and analog signal. This was accomplished by modulating the signal in selected baud rates ranging from 150 to 9600 bps using an economical radio packet capable of identifying and recalling the station code number. The other part is the linking system between the output data and the microcomputer equipped with a software to manage and evaluate the data from 10 surveillance stations for convenient handing of data output, statistical analysis and transmitting warning signal. Data transmission was tested using a baud rate of 1200 bps and was found to contain no detectable error when digital signal was transmitted while analog signal transmission resulted in deviations of less than ± 0.003%. The development of this radio link system provides a future trend for the environmental radiation monitoring network for countries with nuclear power plants or neighboring countries needed to continuously monitor for any abnormal radiation level in the environment. In case that the radiation surveillance system detects a high level of radiation, a warning signal will be transmitted and appropriate actions may be immediately exercised to control impacts of radiation on environment and living things according to international guidelines

Planning the electron traffic in semiconductor networks: A mesoscopic analog of the Braess paradox encountered in road networks

International Nuclear Information System (INIS)

Huant, S.; Liu, P.; Sellier, H.; Baltazar, S.; Hackens, B.; Martins, F.; Bayot, V.; Wallart, X.; Desplanque, L.; Pala, M. G.

2013-01-01

By combining quantum simulations of electron transport and scanning-gate microscopy, we have shown that the current transmitted through a semiconductor two-path rectangular network in the ballistic and coherent regimes of transport can be paradoxically degraded by adding a third path to the network. This is analogous to the Braess paradox occurring in classical networks. Simulations reported here enlighten the role played by congestion in the network

Digital services using quadrature amplitude modulation (QAM) over CATV analog DWDM system

Science.gov (United States)

Yeh, JengRong; Selker, Mark D.; Trail, J.; Piehler, David; Levi, Israel

2000-04-01

Dense Wavelength Division Multiplexing (DWDM) has recently gained great popularity as it provides a cost effective way to increase the transmission capacity of the existing fiber cable plant. For a long time, Dense WDM was exclusively used for baseband digital applications, predominantly in terrestrial long haul networks and in some cases in metropolitan and enterprise networks. Recently, the performance of DWDM components and frequency-stabilized lasers has substantially improved while the costs have down significantly. This makes a variety of new optical network architectures economically viable. The first commercial 8- wavelength DWDM system designed for Hybrid Fiber Coax networks was reported in 1998. This type of DWDM system utilizes Sub-Carrier Multiplexing (SCM) of Quadrature Amplitude Modulated (QAM) signals to transport IP data digital video broadcast and Video on Demand on ITU grid lightwave carriers. The ability of DWDM to provide scalable transmission capacity in the optical layer with SCM granularity is now considered by many to be the most promising technology for future transport and distribution of broadband multimedia services.

Analog voicing detector responds to pitch

Science.gov (United States)

Abel, R. S.; Watkins, H. E.

1967-01-01

Modified electronic voice encoder /Vocoder/ includes an independent analog mode of operation in addition to the conventional digital mode. The Vocoder is a bandwidth compression equipment that permits voice transmission over channels, having only a fraction of the bandwidth required for conventional telephone-quality speech transmission.

Flexible Data Link

Science.gov (United States)

2015-04-01

DDC ) results in more complicated digital (FPGA) processing, yet simplifies the analog design significantly while improving the quality of the...Interleaved CP Cyclic Prefix DAC Digital to Analog Converter DDC Digital Down Converter DDR Double Data Rate DUC Digital Up Converter ENOB Effective

Principles of digital communication and coding

CERN Document Server

Viterbi, Andrew J

2009-01-01

This classic by two digital communications experts is geared toward students of communications theory and to designers of channels, links, terminals, modems, or networks used to transmit and receive digital messages. 1979 edition.

A standardized way to select, evaluate, and test an analog-to-digital converter for ultrawide bandwidth radiofrequency signals based on user's needs, ideal, published,and actual specifications

Science.gov (United States)

Chang, Daniel Y.; Rowe, Neil C.

2012-06-01

The most important adverse impact on the Electronic Warfare (EW) simulation is that the number of signal sources that can be tested simultaneously is relatively small. When the number of signal sources increases, the analog hardware, complexity and costs grow by the order of N2, since the number of connections among N components is O(N*N) and the signal communication is bi-directional. To solve this problem, digitization of the signal is suggested. In digitizing a radiofrequency signal, an Analog-to-Digital Converter (ADC) is widely used. Most research studies on ADCs are conducted from designer/test engineers' perspective. Some research studies are conducted from market's perspective. This paper presents a generic way to select, evaluate and test ultra high bandwidth COTS ADCs and generate requirements for digitizing continuous time signals from the perspective of user's needs. Based on user's needs, as well as vendor's published, ideal and actual specifications, a decision can be made in selecting a proper ADC for an application. To support our arguments and illustrate the methodology, we evaluate a Tektronix TADC-1000, an 8-bit and 12 gigasamples per second ADC. This project is funded by JEWEL lab, NAWCWD at Point Mugu, CA.

Analog and digital image quality:

OpenAIRE

Sardo, Alberto

2004-01-01

Background. Lastly the X ray facilities are moving to a slow, but continuous process of digitalization. The dry laser printers allow hardcopy images with optimum resolution and contrast for all the modalities. In breast imaging, thedelay of digitalization depends to the high cost of digital systems and, attimes, to the doubts of the diagnostic accuracy of reading the breast digital images. Conclusions. The Screen film mammography (SFM) is the most efficient diagnostic modality to detect the b...

Link Prediction in Social Networks: the State-of-the-Art

OpenAIRE

Wang, Peng; Xu, Baowen; Wu, Yurong; Zhou, Xiaoyu

2014-01-01

In social networks, link prediction predicts missing links in current networks and new or dissolution links in future networks, is important for mining and analyzing the evolution of social networks. In the past decade, many works have been done about the link prediction in social networks. The goal of this paper is to comprehensively review, analyze and discuss the state-of-the-art of the link prediction in social networks. A systematical category for link prediction techniques and problems ...

Heuristic Decision Making in Network Linking

NARCIS (Netherlands)

M.J.W. Harmsen - Van Hout (Marjolein); B.G.C. Dellaert (Benedict); P.J.J. Herings (Jean-Jacques)

2015-01-01

textabstractNetwork formation among individuals constitutes an important part of many OR processes, but relatively little is known about how individuals make their linking decisions in networks. This article provides an investigation of heuristic effects in individual linking decisions for

Compliance-Free, Digital SET and Analog RESET Synaptic Characteristics of Sub-Tantalum Oxide Based Neuromorphic Device.

Science.gov (United States)

Abbas, Yawar; Jeon, Yu-Rim; Sokolov, Andrey Sergeevich; Kim, Sohyeon; Ku, Boncheol; Choi, Changhwan

2018-01-19

A two terminal semiconducting device like a memristor is indispensable to emulate the function of synapse in the working memory. The analog switching characteristics of memristor play a vital role in the emulation of biological synapses. The application of consecutive voltage sweeps or pulses (action potentials) changes the conductivity of the memristor which is considered as the fundamental cause of the synaptic plasticity. In this study, a neuromorphic device using an in-situ growth of sub-tantalum oxide switching layer is fabricated, which exhibits the digital SET and analog RESET switching with an electroforming process without any compliance current (compliance free). The process of electroforming and SET is observed at the positive sweeps of +2.4 V and +0.86 V, respectively, while multilevel RESET is observed with the consecutive negative sweeps in the range of 0 V to -1.2 V. The movement of oxygen vacancies and gradual change in the anatomy of the filament is attributed to digital SET and analog RESET switching characteristics. For the Ti/Ta 2 O 3-x /Pt neuromorphic device, the Ti top and Pt bottom electrodes are considered as counterparts of the pre-synaptic input terminal and a post-synaptic output terminal, respectively.

Digital telephony and network integration

CERN Document Server

Keiser, Bernhard E

1995-01-01

What is "digital telephony"? To the authors, the term digital telephony denotes the technology used to provide a completely digital telecommunication system from end-to-end. This implies the use of digital technology from one end instru­ ment through transmission facilities and switching centers to another end instru­ ment. Digital telephony has become possible only because of the recent and on­ going surge of semiconductor developments, allowing microminiaturization and high reliability along with reduced costs. This book deals with both the future and the present. Thus, the first chapter is entitled, "A Network in Transition." As baselines, Chapters 2 and 11 provide the reader with the present status of teler-hone technology in terms of voice digiti­ zation as well as switching principles. The book is an outgrowth of the authors' consulting and teaching experience in the field since the early 1980s. The book has been written to provide both the engineering student and the practicing engineer a working k...

47 CFR 25.212 - Narrowband analog transmissions, digital transmissions, and video transmissions in the GSO Fixed...

Science.gov (United States)

2010-10-01

... 47 Telecommunication 2 2010-10-01 2010-10-01 false Narrowband analog transmissions, digital transmissions, and video transmissions in the GSO Fixed-Satellite Service. 25.212 Section 25.212 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES SATELLITE COMMUNICATIONS...

How to deal with substrate bounce in analog circuits in epi-type CMOS technology

NARCIS (Netherlands)

Nauta, Bram; Hoogzaad, Gian; Hoogzaad, G.; Donnay, S.; Gielen, G.

2003-01-01

Substrate noise is one of the key problems in mixed analog/digital ICs. Although measures are known to reduce substrate noise, the noise will never be completely eliminated since this requires larger chip area or exotic packages and thus higher cost. Analog circuits on digital ICs simply have to be

Fast transient digitizer

International Nuclear Information System (INIS)

Villa, F.

1982-01-01

Method and apparatus for sequentially scanning a plurality of target elements with an electron scanning beam modulated in accordance with variations in a high-frequency analog signal to provide discrete analog signal samples representative of successive portions of the analog signal; coupling the discrete analog signal samples from each of the target elements to a different one of a plurality of high speed storage devices; converting the discrete analog signal samples to equivalent digital signals; and storing the digital signals in a digital memory unit for subsequent measurement or display

Digital Signal Processing and Control for the Study of Gene Networks

Science.gov (United States)

Shin, Yong-Jun

2016-04-01

Thanks to the digital revolution, digital signal processing and control has been widely used in many areas of science and engineering today. It provides practical and powerful tools to model, simulate, analyze, design, measure, and control complex and dynamic systems such as robots and aircrafts. Gene networks are also complex dynamic systems which can be studied via digital signal processing and control. Unlike conventional computational methods, this approach is capable of not only modeling but also controlling gene networks since the experimental environment is mostly digital today. The overall aim of this article is to introduce digital signal processing and control as a useful tool for the study of gene networks.

Multi-digit handwritten sindhi numerals recognition using som neural network

International Nuclear Information System (INIS)

Chandio, A.A.; Jalbani, A.H.; Awan, S.A.

2017-01-01

In this research paper a multi-digit Sindhi handwritten numerals recognition system using SOM Neural Network is presented. Handwritten digits recognition is one of the challenging tasks and a lot of research is being carried out since many years. A remarkable work has been done for recognition of isolated handwritten characters as well as digits in many languages like English, Arabic, Devanagari, Chinese, Urdu and Pashto. However, the literature reviewed does not show any remarkable work done for Sindhi numerals recognition. The recognition of Sindhi digits is a difficult task due to the various writing styles and different font sizes. Therefore, SOM (Self-Organizing Map), a NN (Neural Network) method is used which can recognize digits with various writing styles and different font sizes. Only one sample is required to train the network for each pair of multi-digit numerals. A database consisting of 4000 samples of multi-digits consisting only two digits from 10-50 and other matching numerals have been collected by 50 users and the experimental results of proposed method show that an accuracy of 86.89% is achieved. (author)

Digital Native and Digital Immigrant Use of Scholarly Network for Doctoral Learners

Science.gov (United States)

Berman, Ronald; Hassell, Deliesha

2014-01-01

The Doctoral Community Network (DC) is a learner driven, scholarly community designed to help online doctoral learners successfully complete their dissertation and program of study. While digital natives grew up in an environment immersed in technology, digital immigrants adapted to this environment through their ability to learn and adjust to…

Analog 65/130 nm CMOS 5 GHz Sub-Arrays with ROACH-2 FPGA Beamformers for Hybrid Aperture-Array Receivers

Science.gov (United States)

2017-03-20

factor, where c is the wave speed . Proposed two-level hybrid beamforming architecture consists of an analog sub-array at level-1 (L-element analog...gigabit transceivers, to support 4x10Ge links (SFP+) for high- speed communication. ROACH-2 also supports two ZDOk+ interfaces supporting high speed ADCs...antenna systems with hybrid analog and digital beamforming for millimeter wave 5G ,” IEEE Communications Magazine, vol. 53, no. 1, pp. 186–194, January

Digital approach for the design of statistical analog data acquisition on SoCs

OpenAIRE

Adao Antonio de Souza Junior

2005-01-01

With the current demand for mixed-signal SoCs, an increasing number of designers are looking for ADC architectures that can be easily implemented over digital substrates. Since ADC performance is strongly dependent upon physical and electrical features, it gets more difficult for them to benefit from more recent technologies, where these features are more variable. This way, analog signal acquisition is not allowed to follow an evolutionary trend compatible with Moore’s Law. In fact, such tre...

Digital versus analog complete-arch impressions for single-unit premolar implant crowns : Operating time and patient preference

NARCIS (Netherlands)

Schepke, Ulf; Meijer, Henny J. A.; Kerdijk, Wouter; Cune, Marco S.

Statement of problem. Digital impression-making techniques are supposedly more patient friendly and less time-consuming than analog techniques, but evidence is lacking to substantiate this assumption. Purpose. The purpose of this in vivo within-subject comparison study was to examine patient

Implementing size-optimal discrete neural networks require analog circuitry

Energy Technology Data Exchange (ETDEWEB)

Beiu, V.

1998-12-01

This paper starts by overviewing results dealing with the approximation capabilities of neural networks, as well as bounds on the size of threshold gate circuits. Based on a constructive solution for Kolmogorov`s superpositions the authors show that implementing Boolean functions can be done using neurons having an identity transfer function. Because in this case the size of the network is minimized, it follows that size-optimal solutions for implementing Boolean functions can be obtained using analog circuitry. Conclusions and several comments on the required precision are ending the paper.

Cheating and Feeling Honest: Committing and Punishing Analog versus Digital Academic Dishonesty Behaviors in Higher Education

Science.gov (United States)

Friedman, Adi; Blau,Ina; Eshet-Alkalai, Yoram

2016-01-01

This study examined the phenomenon of academic dishonesty among university students. It was based on Pavela's (1997) framework of types of academic dishonesty (cheating, plagiarism, fabrication, and facilitation) and distinguished between digital and "traditional"- analog dishonesty. The study analyzed cases of academic dishonesty…

Optimalisasi Network Gain Jaringan Digital Melalui Pemanfaatan Kombinasi SFN Dan MFN Di Pulau Jawa Dengan Metode Monte Carlo

Directory of Open Access Journals (Sweden)

Novita Purwaningsih

2015-03-01

Full Text Available Abstrak - Teknologi penyiaran analog saat ini mulai ditinggalkan. Indonesia saat ini sedang melakukan proses transisi untuk berpindah ke tv digital dengan standart DVB-T2 dan merencanakan analog switch off pada tahun 2018. Banyaknya jumlah pemancar, coverage kurang besar, dan persen coverage yang rendah merupakan indikator dari network gain yang kurang optimal. Pada tugas akhir ini dilakukan optimalisasi network gain tujuannya adalah agar coverage pemancar lebih optimal, persen coverage meningkat, dan bisa mengurangi jumlah pemancar sehingga menghemat biaya implementasi. Untuk optimalisasi network gain digunakan metode monte carlo dengan cara melakukan proses selection atau combine pada daerah yang menerima sinyal lebih dari satu. Dari simulasi yang telah dilakukan, optimasi dengan metode monte carlo menunjukkan hasil persentase coverage yang paling bagus yaitu 71.96% dan yang paling buruk zona 7 yaitu 58,81% untuk skala nasional zona 4. Jumlah pemancar dapat dikurangi sebanyak 3 pemancar dari total 33 pemancar yang ada, pemancar yang dapat dihilangkan adalah pemancar di kota Magelang di zona 6 dan Sumedang dan Majalengka di zona 5. Nilai rata-rata persen coverage di seluruh zona adalah 52.7% dan hasil optimalisasi telah melampaui nilai rata-rata yaitu 64.35%.

Fault tolerant digital control systems for boiling water reactors

International Nuclear Information System (INIS)

Chakraborty, S.; Cash, N.R.

1986-01-01

In a Boiling Water Reactor nuclear power plant, the power generation control function is divided into several systems, each system controlling only a part of the total plant. Presently, each system is controlled by conventional analog or digital logic circuits with little interaction for coordinated control. The advent of microprocessors has allowed the development of distributed fault-tolerant digital controls. The objective is to replace these conventional controls with fault-tolerant digital controls connected together with digital communication links to form a fully integrated nuclear power plant control system

The influence of the analog-to-digital conversion error on the JT-60 plasma position/shape feedback control system

International Nuclear Information System (INIS)

Yoshida, Michiharu; Kurihara, Kenichi

1995-12-01

In the plasma feedback control system (PFCS) and the direct digital controller (DDC) for the poloidal field coil power supply in the JT-60 tokamak, it is necessary to observe signals of all the poloidal field coil currents. Each of the signals, originally measured by a single sensor, is distributed to the PFCS and DDC through different cable routes and different analog-to-digital converters from each other. This produces the conversion error to the amount of several bits. Consequently, proper voltage from feedback calculation cannot be applied to the coil, and hence the control performance is possibly supposed to deteriorate to a certain extent. This paper describes how this error makes an influence on the plasma horizontal position control and how to improve the deteriorated control performance. (author)

Effects of multi-state links in network community detection

International Nuclear Information System (INIS)

Rocco, Claudio M.; Moronta, José; Ramirez-Marquez, José E.; Barker, Kash

2017-01-01

A community is defined as a group of nodes of a network that are densely interconnected with each other but only sparsely connected with the rest of the network. The set of communities (i.e., the network partition) and their inter-community links could be derived using special algorithms account for the topology of the network and, in certain cases, the possible weights associated to the links. In general, the set of weights represents some characteristic as capacity, flow and reliability, among others. The effects of considering weights could be translated to obtain a different partition. In many real situations, particularly when modeling infrastructure systems, networks must be modeled as multi-state networks (e.g., electric power networks). In such networks, each link is characterized by a vector of known random capacities (i.e., the weight on each link could vary according to a known probability distribution). In this paper a simple Monte Carlo approach is proposed to evaluate the effects of multi-state links on community detection as well as on the performance of the network. The approach is illustrated with the topology of an electric power system. - Highlights: • Identify network communities when considering multi-state links. • Identified how effects of considering weights translate to different partition. • Identified importance of Inter-Community Links and changes with respect to community. • Preamble to performing a resilience assessment able to mimic the evolution of the state of each community.

Alaska Seismic Network Upgrade and Expansion

Science.gov (United States)

Sandru, J. M.; Hansen, R. A.; Estes, S. A.; Fowler, M.

2009-12-01

AEIC (Alaska Earthquake Information Center) has begun the task of upgrading the older regional seismic monitoring sites that have been in place for a number of years. Many of the original sites (some dating to the 1960's) are still single component analog technology. This was a very reasonable and ultra low power reliable system for its day. However with the advanced needs of today's research community, AEIC has begun upgrading to Broadband and Strong Motion Seismometers, 24 bit digitizers and high-speed two-way communications, while still trying to maintain the utmost reliability and maintaining low power consumption. Many sites have been upgraded or will be upgraded from single component to triaxial broad bands and triaxial accerometers. This provided much greater dynamic range over the older antiquated technology. The challenge is compounded by rapidly changing digital technology. Digitizersand data communications based on analog phone lines utilizing 9600 baud modems and RS232 are becoming increasingly difficult to maintain and increasingly expensive compared to current methods that use Ethernet, TCP/IP and UDP connections. Gaining a reliable Internet connection can be as easy as calling up an ISP and having a DSL connection installed or may require installing our own satellite uplink, where other options don't exist. LANs are accomplished with a variety of communications devices such as spread spectrum 900 MHz radios or VHF radios for long troublesome shots. WANs are accomplished with a much wider variety of equipment. Traditional analog phone lines are being used in some instances, however 56K lines are much more desirable. Cellular data links have become a convenient option in semiurban environments where digital cellular coverage is available. Alaska is slightly behind the curve on cellular technology due to its low population density and vast unpopulated areas but has emerged into this new technology in the last few years. Partnerships with organizations

The Algorithm of Link Prediction on Social Network

Directory of Open Access Journals (Sweden)

Liyan Dong

2013-01-01

Full Text Available At present, most link prediction algorithms are based on the similarity between two entities. Social network topology information is one of the main sources to design the similarity function between entities. But the existing link prediction algorithms do not apply the network topology information sufficiently. For lack of traditional link prediction algorithms, we propose two improved algorithms: CNGF algorithm based on local information and KatzGF algorithm based on global information network. For the defect of the stationary of social network, we also provide the link prediction algorithm based on nodes multiple attributes information. Finally, we verified these algorithms on DBLP data set, and the experimental results show that the performance of the improved algorithm is superior to that of the traditional link prediction algorithm.

Analytic analysis of auxetic metamaterials through analogy with rigid link systems

OpenAIRE

Rayneau-Kirkhope, Daniel; Zhang, Chengzhao; Theran, Louis; Dias, Marcelo A.

2017-01-01

Recent progress in advanced additive manufacturing techniques has stimulated the growth of the field of mechanical metamaterials. One area particular interest in this subject is the creation of auxetic material properties through elastic instability. This paper focuses on a novel methodology in the analysis of auxetic metamaterials through analogy with rigid link lattice systems. Our analytic methodology gives extremely good agreement with finite element simulations for both the onset of elas...

A method for identifying hierarchical sub-networks / modules and weighting network links based on their similarity in sub-network / module affiliation

Directory of Open Access Journals (Sweden)

WenJun Zhang

2016-06-01

Full Text Available Some networks, including biological networks, consist of hierarchical sub-networks / modules. Based on my previous study, in present study a method for both identifying hierarchical sub-networks / modules and weighting network links is proposed. It is based on the cluster analysis in which between-node similarity in sets of adjacency nodes is used. Two matrices, linkWeightMat and linkClusterIDs, are achieved by using the algorithm. Two links with both the same weight in linkWeightMat and the same cluster ID in linkClusterIDs belong to the same sub-network / module. Two links with the same weight in linkWeightMat but different cluster IDs in linkClusterIDs belong to two sub-networks / modules at the same hirarchical level. However, a link with an unique cluster ID in linkClusterIDs does not belong to any sub-networks / modules. A sub-network / module of the greater weight is the more connected sub-network / modules. Matlab codes of the algorithm are presented.

Digitized forensics: retaining a link between physical and digital crime scene traces using QR-codes

Science.gov (United States)

Hildebrandt, Mario; Kiltz, Stefan; Dittmann, Jana

2013-03-01

The digitization of physical traces from crime scenes in forensic investigations in effect creates a digital chain-of-custody and entrains the challenge of creating a link between the two or more representations of the same trace. In order to be forensically sound, especially the two security aspects of integrity and authenticity need to be maintained at all times. Especially the adherence to the authenticity using technical means proves to be a challenge at the boundary between the physical object and its digital representations. In this article we propose a new method of linking physical objects with its digital counterparts using two-dimensional bar codes and additional meta-data accompanying the acquired data for integration in the conventional documentation of collection of items of evidence (bagging and tagging process). Using the exemplary chosen QR-code as particular implementation of a bar code and a model of the forensic process, we also supply a means to integrate our suggested approach into forensically sound proceedings as described by Holder et al.1 We use the example of the digital dactyloscopy as a forensic discipline, where currently progress is being made by digitizing some of the processing steps. We show an exemplary demonstrator of the suggested approach using a smartphone as a mobile device for the verification of the physical trace to extend the chain-of-custody from the physical to the digital domain. Our evaluation of the demonstrator is performed towards the readability and the verification of its contents. We can read the bar code despite its limited size of 42 x 42 mm and rather large amount of embedded data using various devices. Furthermore, the QR-code's error correction features help to recover contents of damaged codes. Subsequently, our appended digital signature allows for detecting malicious manipulations of the embedded data.

Multi-scale location analysis of vulnerabilities and their link to disturbances within digital ecosystems

OpenAIRE

Jackson, Jennifer

2017-01-01

As computer networks evolve, so too does the techniques used by attackers to exploit new vulnerabilities. Natural ecosystems already have resistant and resilient properties that help protect them from unwanted disturbances despite the existence of different vulnerabilities. Computer networks and their environments can be considered as digital ecosystems with different vulnerabilities, and security attacks can be considered as unwanted disturbances. Analysis of vulnerabilities and attacks from...

Information retrieval system with ability of analogical inference using semantic network and function of fuzzification

Energy Technology Data Exchange (ETDEWEB)

Nakamura, K; Iwai, S

1982-01-01

In information retrieval system, it is necessary to grasp user's subject of interest in order to present appropriate documents to the user. In this paper, the authors propose a model of human ability of analogical inference based on association between key words and, using it, construct an information retrieval system in which the computer with the ability learns its user's subject of interest through question-answering with the user. In this system, the association between key words is represented by a semantic network, and a function of fuzzification of input information is introduced in the semantic network to implement the ability of analogical inference based on the association. Finally, the effect of analogical inference on the learning efficiency of the system is investigated. 5 references.

CCTV networking and digital technology

CERN Document Server

Damjanovski, Vlado

2005-01-01

Closed circuit television (CCTV) is experiencing a leap in technology using digital techniques, networking and the Internet. The new edition of this high-level professional reference retains the particulars that made the first edition a success, including the details of CCD cameras, lenses, coaxial cables, fiber-optics, and system design, but it is expanded to cover all video compression techniques used in the ever increasing assortment of digital video recorders (DVRs) available on the market today. This new edition of the book CCTV demystifies DVR technology. It also serves to clarify the te

The vulnerability of the global container shipping network to targeted link disruption

CSIR Research Space (South Africa)

Viljoen, NM

2016-11-01

Full Text Available transport, complex network theory has had limited application in studying the vulnerability of maritime networks. This study uses targeted link disruption to investigate the strategy specific vulnerability of the network. Although nodal infrastructure...

Analog electronics for radiation detection

CERN Document Server

2016-01-01

Analog Electronics for Radiation Detection showcases the latest advances in readout electronics for particle, or radiation, detectors. Featuring chapters written by international experts in their respective fields, this authoritative text: Defines the main design parameters of front-end circuitry developed in microelectronics technologies Explains the basis for the use of complementary metal oxide semiconductor (CMOS) image sensors for the detection of charged particles and other non-consumer applications Delivers an in-depth review of analog-to-digital converters (ADCs), evaluating the pros and cons of ADCs integrated at the pixel, column, and per-chip levels Describes incremental sigma delta ADCs, time-to-digital converter (TDC) architectures, and digital pulse-processing techniques complementary to analog processing Examines the fundamental parameters and front-end types associated with silicon photomultipliers used for single visible-light photon detection Discusses pixel sensors ...

Effect of digital scrambling on satellite communication links

Science.gov (United States)

Dessouky, K.

1985-01-01

Digital data scrambling has been considered for communication systems using NRZ symbol formats. The purpose is to increase the number of transitions in the data to improve the performance of the symbol synchronizer. This is accomplished without expanding the bandwidth but at the expense of increasing the data bit error rate (BER). Models for the scramblers/descramblers of practical interest are presented together with the appropriate link model. The effects of scrambling on the performance of coded and uncoded links are studied. The results are illustrated by application to the Tracking and Data Relay Satellite System (TDRSS) links. Conclusions regarding the usefulness of scrambling are also given.

Fluid intelligence allows flexible recruitment of the parieto-frontal network in analogical reasoning.

Science.gov (United States)

Preusse, Franziska; van der Meer Elke; Deshpande, Gopikrishna; Krueger, Frank; Wartenburger, Isabell

2011-01-01

Fluid intelligence is the ability to think flexibly and to understand abstract relations. People with high fluid intelligence (hi-fluIQ) perform better in analogical reasoning tasks than people with average fluid intelligence (ave-fluIQ). Although previous neuroimaging studies reported involvement of parietal and frontal brain regions in geometric analogical reasoning (which is a prototypical task for fluid intelligence), however, neuroimaging findings on geometric analogical reasoning in hi-fluIQ are sparse. Furthermore, evidence on the relation between brain activation and intelligence while solving cognitive tasks is contradictory. The present study was designed to elucidate the cerebral correlates of geometric analogical reasoning in a sample of hi-fluIQ and ave-fluIQ high school students. We employed a geometric analogical reasoning task with graded levels of task difficulty and confirmed the involvement of the parieto-frontal network in solving this task. In addition to characterizing the brain regions involved in geometric analogical reasoning in hi-fluIQ and ave-fluIQ, we found that blood oxygenation level dependency (BOLD) signal changes were greater for hi-fluIQ than for ave-fluIQ in parietal brain regions. However, ave-fluIQ showed greater BOLD signal changes in the anterior cingulate cortex and medial frontal gyrus than hi-fluIQ. Thus, we showed that a similar network of brain regions is involved in geometric analogical reasoning in both groups. Interestingly, the relation between brain activation and intelligence is not mono-directional, but rather, it is specific for each brain region. The negative brain activation-intelligence relationship in frontal brain regions in hi-fluIQ goes along with a better behavioral performance and reflects a lower demand for executive monitoring compared to ave-fluIQ individuals. In conclusion, our data indicate that flexibly modulating the extent of regional cerebral activity is characteristic for fluid intelligence.

Fluid intelligence allows flexible recruitment of the parieto-frontal network in analogical reasoning.

Directory of Open Access Journals (Sweden)

Franziska ePreusse

2011-03-01

Full Text Available Fluid intelligence is the ability to think flexibly and to understand abstract relations. People with high fluid intelligence (hi-fluIQ perform better in analogical reasoning tasks than people with average fluid intelligence (ave-fluIQ. Although previous neuroimaging studies reported involvement of parietal and frontal brain regions in geometric analogical reasoning (which is a prototypical task for fluid intelligence, however, neuroimaging findings on geometric analogical reasoning in hi-fluIQ are sparse. Furthermore, evidence on the relation between brain activation and intelligence while solving cognitive tasks is contradictory. The present study was designed to elucidate the cerebral correlates of geometric analogical reasoning in a sample of hi-fluIQ and ave-fluIQ high school students. We employed a geometric analogical reasoning task with graded levels of task difficulty and confirmed the involvement of the parieto-frontal network in solving this task. In addition to characterizing the brain regions involved in geometric analogical reasoning in hi-fluIQ and ave-fluIQ, we found that blood oxygenation level dependency (BOLD signal changes were greater for hi-fluIQ than for ave-fluIQ in parietal brain regions. However, ave-fluIQ showed greater BOLD signal changes in the anterior cingulate cortex and medial frontal gyrus than hi-fluIQ. Thus, we showed that a similar network of brain regions is involved in geometric analogical reasoning in both groups. Interestingly, the relation between brain activation and intelligence is not mono-directional, but rather, it is specific for each brain region. The negative brain activation–intelligence relationship in frontal brain regions in hi-fluIQ goes along with a better behavioral performance and reflects a lower demand for executive monitoring compared to ave-fluIQ individuals. In conclusion, our data indicate that flexibly modulating the extent of regional cerebral activity is characteristic for

A COMPARATIVE STUDY OF SYSTEM NETWORK ARCHITECTURE Vs DIGITAL NETWORK ARCHITECTURE

OpenAIRE

Seema; Mukesh Arya

2011-01-01

The efficient managing system of sources is mandatory for the successful running of any network. Here this paper describes the most popular network architectures one of developed by IBM, System Network Architecture (SNA) and other is Digital Network Architecture (DNA). As we know that the network standards and protocols are needed for the network developers as well as users. Some standards are The IEEE 802.3 standards (The Institute of Electrical and Electronics Engineers 1980) (LAN), IBM Sta...

Fermilab accelerator control system: Analog monitoring facilities

International Nuclear Information System (INIS)

Seino, K.; Anderson, L.; Smedinghoff, J.

1987-10-01

Thousands of analog signals are monitored in different areas of the Fermilab accelerator complex. For general purposes, analog signals are sent over coaxial or twinaxial cables with varying lengths, collected at fan-in boxes and digitized with 12 bit multiplexed ADCs. For higher resolution requirements, analog signals are digitized at sources and are serially sent to the control system. This paper surveys ADC subsystems that are used with the accelerator control systems and discusses practical problems and solutions, and it describes how analog data are presented on the console system

Analog memristive synapse in spiking networks implementing unsupervised learning

Directory of Open Access Journals (Sweden)

Erika Covi

2016-10-01

Full Text Available Emerging brain-inspired architectures call for devices that can emulate the functionality of biological synapses in order to implement new efficient computational schemes able to solve ill-posed problems. Various devices and solutions are still under investigation and, in this respect, a challenge is opened to the researchers in the field. Indeed, the optimal candidate is a device able to reproduce the complete functionality of a synapse, i.e. the typical synaptic process underlying learning in biological systems (activity-dependent synaptic plasticity. This implies a device able to change its resistance (synaptic strength, or weight upon proper electrical stimuli (synaptic activity and showing several stable resistive states throughout its dynamic range (analog behavior. Moreover, it should be able to perform spike timing dependent plasticity (STDP, an associative homosynaptic plasticity learning rule based on the delay time between the two firing neurons the synapse is connected to. This rule is a fundamental learning protocol in state-of-art networks, because it allows unsupervised learning. Notwithstanding this fact, STDP-based unsupervised learning has been proposed several times mainly for binary synapses rather than multilevel synapses composed of many binary memristors. This paper proposes an HfO2-based analog memristor as a synaptic element which performs STDP within a small spiking neuromorphic network operating unsupervised learning for character recognition. The trained network is able to recognize five characters even in case incomplete or noisy characters are displayed and it is robust to a device-to-device variability of up to +/-30%.

Analog Memristive Synapse in Spiking Networks Implementing Unsupervised Learning.

Science.gov (United States)

Covi, Erika; Brivio, Stefano; Serb, Alexander; Prodromakis, Themis; Fanciulli, Marco; Spiga, Sabina

2016-01-01

Emerging brain-inspired architectures call for devices that can emulate the functionality of biological synapses in order to implement new efficient computational schemes able to solve ill-posed problems. Various devices and solutions are still under investigation and, in this respect, a challenge is opened to the researchers in the field. Indeed, the optimal candidate is a device able to reproduce the complete functionality of a synapse, i.e., the typical synaptic process underlying learning in biological systems (activity-dependent synaptic plasticity). This implies a device able to change its resistance (synaptic strength, or weight) upon proper electrical stimuli (synaptic activity) and showing several stable resistive states throughout its dynamic range (analog behavior). Moreover, it should be able to perform spike timing dependent plasticity (STDP), an associative homosynaptic plasticity learning rule based on the delay time between the two firing neurons the synapse is connected to. This rule is a fundamental learning protocol in state-of-art networks, because it allows unsupervised learning. Notwithstanding this fact, STDP-based unsupervised learning has been proposed several times mainly for binary synapses rather than multilevel synapses composed of many binary memristors. This paper proposes an HfO 2 -based analog memristor as a synaptic element which performs STDP within a small spiking neuromorphic network operating unsupervised learning for character recognition. The trained network is able to recognize five characters even in case incomplete or noisy images are displayed and it is robust to a device-to-device variability of up to ±30%.

The New Age and Mystical Imaginary of Digital Networks

Directory of Open Access Journals (Sweden)

Carlos AGUIAR

2011-01-01

Full Text Available This article seeks to probe the mystical imaginary present in digital networks from an online participatory study about the presence of the new age movement on the internet, especially the Brazilian context of the movement. The proposal is to experience on internet and through internet a mystical and virtual experience, creating a singular pathway through the network, capable of transmitting qualitative peculiarities of this presence and providing subsidies to the approach of part of the contemporary imaginary in relation to the sacred shared in digital networks.

Manufacture of Platform Prototype for Digital Safety System

International Nuclear Information System (INIS)

Lee, S. Y.; Kim, J. S.; Kim, J. M.

2010-01-01

Unit controller is a basic unit of digital safety system platform prototype. The typical unit controller is comprised of CPB(CPU board), CMB(communication board), AIB(Analog input board), AOB(Analog output board), CIB(contact input board), COB(contact output board), and a subrack. It is developed according to H/W development procedure and S/W development life cycle. A digital safety system(for example, plant protection system) is the assemblies of unit controllers. CPB performs the function of each system. DSP(digital signal processor) is built in CPB. CMB is responsible for communication between unit controllers. NSD(Network Switching Device) exchanges data between the unit controllers. Each unit controller of the platform are connected to NSD through CMB. Reliability analyses on unit controller and NSD are performed. These reliability data are used as input of technical validation

Is the Link from Working Memory to Analogy Causal? No Analogy Improvements following Working Memory Training Gains

OpenAIRE

Richey, J. Elizabeth; Phillips, Jeffrey S.; Schunn, Christian D.; Schneider, Walter

2014-01-01

Analogical reasoning has been hypothesized to critically depend upon working memory through correlational data [1], but less work has tested this relationship through experimental manipulation [2]. An opportunity for examining the connection between working memory and analogical reasoning has emerged from the growing, although somewhat controversial, body of literature suggests complex working memory training can sometimes lead to working memory improvements that transfer to novel working mem...

SOI Fully complementary BI-JFET-MOS technology for analog-digital applications with vertical BJT's

International Nuclear Information System (INIS)

Delevoye, E.; Blanc, J.P.; Bonaime, J.; Pontcharra, J. de; Gautier, J.; Martin, F.; Truche, R.

1993-01-01

A silicon-on-insulator, fully complementary, Bi-JFET-MOS technology has been developed for realizing multi-megarad hardened mixed analog-digital circuits. The six different active components plus resistors and capacitors have been successfully integrated in a 25-mask process using SIMOX substrate and 1 μm thick epitaxial layer. Different constraints such as device compatibility, complexity not higher than BiCMOS technology and breakdown voltages suitable for analog applications have been considered. Several process splits have been realized and all the characteristics presented here have been measured on the same split. P + gate is used for PMOS transistor to get N and PMOST symmetrical characteristics. Both NPN and PNP vertical bipolar transistors with poly-emitters show f T > 5 GHz. 2-separated gate JFET's need no additional mask. (authors). 9 figs., 1 tab

Advances in Analog Circuit Design 2015

CERN Document Server

Baschirotto, Andrea; Harpe, Pieter

2016-01-01

This book is based on the 18 tutorials presented during the 24th workshop on Advances in Analog Circuit Design. Expert designers present readers with information about a variety of topics at the frontier of analog circuit design, including low-power and energy-efficient analog electronics, with specific contributions focusing on the design of efficient sensor interfaces and low-power RF systems. This book serves as a valuable reference to the state-of-the-art, for anyone involved in analog circuit research and development. ·         Provides a state-of-the-art reference in analog circuit design, written by experts from industry and academia; ·         Presents material in a tutorial-based format; ·         Includes coverage of high-performance analog-to-digital and digital to analog converters, integrated circuit design in scaled technologies, and time-domain signal processing.

Analog circuit design

CERN Document Server

Dobkin, Bob

2012-01-01

Analog circuit and system design today is more essential than ever before. With the growth of digital systems, wireless communications, complex industrial and automotive systems, designers are being challenged to develop sophisticated analog solutions. This comprehensive source book of circuit design solutions aids engineers with elegant and practical design techniques that focus on common analog challenges. The book's in-depth application examples provide insight into circuit design and application solutions that you can apply in today's demanding designs. <

Predicting Hidden Links in Supply Networks

Directory of Open Access Journals (Sweden)

A. Brintrup

2018-01-01

Full Text Available Manufacturing companies often lack visibility of the procurement interdependencies between the suppliers within their supply network. However, knowledge of these interdependencies is useful to plan for potential operational disruptions. In this paper, we develop the Supply Network Link Predictor (SNLP method to infer supplier interdependencies using the manufacturer’s incomplete knowledge of the network. SNLP uses topological data to extract relational features from the known network to train a classifier for predicting potential links. Using a test case from the automotive industry, four features are extracted: (i number of existing supplier links, (ii overlaps between supplier product portfolios, (iii product outsourcing associations, and (iv likelihood of buyers purchasing from two suppliers together. Naïve Bayes and Logistic Regression are then employed to predict whether these features can help predict interdependencies between two suppliers. Our results show that these features can indeed be used to predict interdependencies in the network and that predictive accuracy is maximised by (i and (iii. The findings give rise to the exciting possibility of using data analytics for improving supply chain visibility. We then proceed to discuss to what extent such approaches can be adopted and their limitations, highlighting next steps for future work in this area.

A 6 device SOI new technology for mixed analog-digital and rad-hard applications

International Nuclear Information System (INIS)

Blanc, J.P.; Bonaime, J.; Delevoye, E.; Pontcharra, J. de; Gautier, J.; Truche, R.

1993-01-01

DMILL technology is being developed for very rad-hard analog-digital applications, such as space and military circuits or as electronics for the future generation of high energy collider (LHC, CERN, Geneva). Both CMOS and junction (JFET and bipolar) transistors are needed. A new process has been integrated, based on a 1.2μm thick silicon film on insulator (SIMOX plus epitaxy), a complete dielectric isolation and low temperature process. The mean feature is that six different components are fabricated on the same wafer, taking into account the 12 volts supply voltage constraint for some analog applications. The first electrical characteristics are presented in this paper. The optimization capabilities of such a hardened CBi-CJ-CMOS technology are discussed

Comparison of the analog and digital pulse-shaping methods in signal processing in nuclear detections

International Nuclear Information System (INIS)

Golnabi, H.

2002-01-01

The goal of this article is to describe the potential applications of the new improved digital techniques and provide a meaningful figure of merit for the comparison of the analog and digital methods. The experimental operation of a typical digital pulse shaper used in a spectrometer with the 23 Na source and a Ge y-ray detector is discussed. The effect of different imposed dead time on the counted pulses is investigated. It is noticed that nuclear events distribution in all ranges of dead time does not obey Poisson's law and deviation from this distribution depends on the counting rate. For a given dead time, deviation from this distribution increases linearly by increasing imposed dead time. For a fixed dead time, when counting rate increases deviation from Poisson's distribution law increases accordingly, and vice versa. (Author)

Development of Alarm System link Drawing for Operation Support for APR1400 Digital Main Control Room

Energy Technology Data Exchange (ETDEWEB)

Kim, Ki-Hwan [KHNP CRI, Daejeon (Korea, Republic of)

2016-10-15

Digitalized MMI(Man-Machine Interface) including Digital Main Control Room(MCR) and digital I and C system was being applied for SKN 3 and 4 Nuclear Power Plant(NPP) and subsequent APR1400 NPP type. But, operators can not easily find instrument for alarm immediately. Therefore, Alarm system is required to easily find instrument for Alarm. For this implementation, we will plan system design considering design feature without affecting network load and CPU load. We have developed Alarm system link drawing for digital MCR. Operators of the digitalized MCR navigates from their consoles to the drawings related to the plant alarms and their instruments or the operation status. Such method gives cognitive load to the operators having to travel to different locations in finding the related information. Screen Sharing System, which is the fundamental technique for Drawing Interconnection Alarm System is close to completion, and it should be functionally tested and verified by the human factor engineering. For the actual application to the operating plants, the drawings to be interconnected to the alarms and the opinions from the operators/maintenance departments for designating alarm number should be surveyed, Also, another function that allows the access to the alarm related drawings not only from the MCR but also from the other offices.

Development of Alarm System link Drawing for Operation Support for APR1400 Digital Main Control Room

International Nuclear Information System (INIS)

Kim, Ki-Hwan

2016-01-01

Digitalized MMI(Man-Machine Interface) including Digital Main Control Room(MCR) and digital I and C system was being applied for SKN 3 and 4 Nuclear Power Plant(NPP) and subsequent APR1400 NPP type. But, operators can not easily find instrument for alarm immediately. Therefore, Alarm system is required to easily find instrument for Alarm. For this implementation, we will plan system design considering design feature without affecting network load and CPU load. We have developed Alarm system link drawing for digital MCR. Operators of the digitalized MCR navigates from their consoles to the drawings related to the plant alarms and their instruments or the operation status. Such method gives cognitive load to the operators having to travel to different locations in finding the related information. Screen Sharing System, which is the fundamental technique for Drawing Interconnection Alarm System is close to completion, and it should be functionally tested and verified by the human factor engineering. For the actual application to the operating plants, the drawings to be interconnected to the alarms and the opinions from the operators/maintenance departments for designating alarm number should be surveyed, Also, another function that allows the access to the alarm related drawings not only from the MCR but also from the other offices

Digital Networked Information Society and Public Health: Problems and Promises of Networked Health Communication of Lay Publics.

Science.gov (United States)

Kim, Jeong-Nam

2018-01-01

This special issue of Health Communication compiles 10 articles to laud the promise and yet confront the problems in the digital networked information society related to public health. We present this anthology of symphony and cacophony of lay individuals' communicative actions in a digital networked information society. The collection of problems and promise of the new digital world may be a cornerstone joining two worlds-pre- and postdigital network society-and we hope this special issue will help better shape our future states of public health.

4-bit digital to analog converter using R-2R ladder and binary weighted resistors

Science.gov (United States)

Diosanto, J.; Batac, M. L.; Pereda, K. J.; Caldo, R.

2017-06-01

The use of a 4-bit digital-to-analog converter using two methods; Binary Weighted Resistors and R-2R Ladder is designed and presented in this paper. The main components that were used in constructing both circuits were different resistor values, operational amplifier (LM741) and single pole double throw switches. Both circuits were designed using MULTISIM software to be able to test the circuit for its ideal application and FRITZING software for the layout designing and fabrication to the printed circuit board. The implementation of both systems in an actual circuit benefits in determining and comparing the advantages and disadvantages of each. It was realized that the binary weighted circuit is more efficient DAC, having lower percentage error of 0.267% compared to R-2R ladder circuit which has a minimum of percentage error of 4.16%.

From Indymedia to Anonymous: rethinking action and identity in digital cultures

OpenAIRE

McDonald, Kevin

2015-01-01

The period following the social mobilizations of 2011 has seen a renewed focus on the place of communication in collective action, linked to the increasing importance of digital communications. Framed in terms of personalized ‘connective action’ or the social morphology of networks, these analyses have criticized previously dominant models of ‘collective identity’, arguing that collective action needs to be understood as ‘digital networking’. These influential approaches have been significant...

Control theory of digitally networked dynamic systems

CERN Document Server

Lunze, Jan

2013-01-01

The book gives an introduction to networked control systems and describes new modeling paradigms, analysis methods for event-driven, digitally networked systems, and design methods for distributed estimation and control. Networked model predictive control is developed as a means to tolerate time delays and packet loss brought about by the communication network. In event-based control the traditional periodic sampling is replaced by state-dependent triggering schemes. Novel methods for multi-agent systems ensure complete or clustered synchrony of agents with identical or with individual dynamic

Identification of hybrid node and link communities in complex networks.

Science.gov (United States)

He, Dongxiao; Jin, Di; Chen, Zheng; Zhang, Weixiong

2015-03-02

Identifying communities in complex networks is an effective means for analyzing complex systems, with applications in diverse areas such as social science, engineering, biology and medicine. Finding communities of nodes and finding communities of links are two popular schemes for network analysis. These schemes, however, have inherent drawbacks and are inadequate to capture complex organizational structures in real networks. We introduce a new scheme and an effective approach for identifying complex mixture structures of node and link communities, called hybrid node-link communities. A central piece of our approach is a probabilistic model that accommodates node, link and hybrid node-link communities. Our extensive experiments on various real-world networks, including a large protein-protein interaction network and a large network of semantically associated words, illustrated that the scheme for hybrid communities is superior in revealing network characteristics. Moreover, the new approach outperformed the existing methods for finding node or link communities separately.

Identification of hybrid node and link communities in complex networks

Science.gov (United States)

He, Dongxiao; Jin, Di; Chen, Zheng; Zhang, Weixiong

2015-03-01

Identifying communities in complex networks is an effective means for analyzing complex systems, with applications in diverse areas such as social science, engineering, biology and medicine. Finding communities of nodes and finding communities of links are two popular schemes for network analysis. These schemes, however, have inherent drawbacks and are inadequate to capture complex organizational structures in real networks. We introduce a new scheme and an effective approach for identifying complex mixture structures of node and link communities, called hybrid node-link communities. A central piece of our approach is a probabilistic model that accommodates node, link and hybrid node-link communities. Our extensive experiments on various real-world networks, including a large protein-protein interaction network and a large network of semantically associated words, illustrated that the scheme for hybrid communities is superior in revealing network characteristics. Moreover, the new approach outperformed the existing methods for finding node or link communities separately.

Digital implementation of a neural network for imaging

Science.gov (United States)

Wood, Richard; McGlashan, Alex; Yatulis, Jay; Mascher, Peter; Bruce, Ian

2012-10-01

This paper outlines the design and testing of a digital imaging system that utilizes an artificial neural network with unsupervised and supervised learning to convert streaming input (real time) image space into parameter space. The primary objective of this work is to investigate the effectiveness of using a neural network to significantly reduce the information density of streaming images so that objects can be readily identified by a limited set of primary parameters and act as an enhanced human machine interface (HMI). Many applications are envisioned including use in biomedical imaging, anomaly detection and as an assistive device for the visually impaired. A digital circuit was designed and tested using a Field Programmable Gate Array (FPGA) and an off the shelf digital camera. Our results indicate that the networks can be readily trained when subject to limited sets of objects such as the alphabet. We can also separate limited object sets with rotational and positional invariance. The results also show that limited visual fields form with only local connectivity.

Accuracy of Analog Fiber-Optic Links in Pulsed Radiation Environments

International Nuclear Information System (INIS)

E K Miller; G S Macrum; I J McKenna

2007-01-01

second case, we present data using a state-of-the-art fiber-optic link for single-shot transmission and recording, fielded at the OMEGA laser facility on high-yield fusion experiments. Gamma reaction history data are measured with a gas Cherenkov detector (GCD) [4], [5] and transmitted by M-Z link to a 12 GHz digitizer. Since radiation effects on the fibers are not above the noise floor, the error analysis for the unfolded data is dominated by the performance of the fast digitizer, the photoreceiver, and the laser

Computer simulation of randomly cross-linked polymer networks

International Nuclear Information System (INIS)

Williams, Timothy Philip

2002-01-01

In this work, Monte Carlo and Stochastic Dynamics computer simulations of mesoscale model randomly cross-linked networks were undertaken. Task parallel implementations of the lattice Monte Carlo Bond Fluctuation model and Kremer-Grest Stochastic Dynamics bead-spring continuum model were designed and used for this purpose. Lattice and continuum precursor melt systems were prepared and then cross-linked to varying degrees. The resultant networks were used to study structural changes during deformation and relaxation dynamics. The effects of a random network topology featuring a polydisperse distribution of strand lengths and an abundance of pendant chain ends, were qualitatively compared to recent published work. A preliminary investigation into the effects of temperature on the structural and dynamical properties was also undertaken. Structural changes during isotropic swelling and uniaxial deformation, revealed a pronounced non-affine deformation dependant on the degree of cross-linking. Fractal heterogeneities were observed in the swollen model networks and were analysed by considering constituent substructures of varying size. The network connectivity determined the length scales at which the majority of the substructure unfolding process occurred. Simulated stress-strain curves and diffraction patterns for uniaxially deformed swollen networks, were found to be consistent with experimental findings. Analysis of the relaxation dynamics of various network components revealed a dramatic slowdown due to the network connectivity. The cross-link junction spatial fluctuations for networks close to the sol-gel threshold, were observed to be at least comparable with the phantom network prediction. The dangling chain ends were found to display the largest characteristic relaxation time. (author)

Progress on the development of a detector mounted analog and digital readout system for the ATLAS TRT

CERN Document Server

Baxter, C; Dressnandt, N; Gay, C; Lundberg, B; Munar, A; Mayers, G; Newcomer, M; Van Berg, R; Williams, H H

2004-01-01

The 430,000 element ATLAS Transition Radiation straw tube Tracker (TRT) is divided into a central barrel tracker consisting of 104,000 axially mounted straws and two radially arranged end caps on either side of the barrel with 160,000 straws each. To achieve a track position resolution of 140 mu m, the front end electronics must operate at a low (2fC) threshold with a time marking capability of ~1ns. Two ASICs, the ASDBLR and DTMROC provide the complete pipelined readout chain. Custom designed FBGA packages for the ASICs provide a small enough outline to be detector mounted and the extensive use of low level differential signals make mounting the analog packages on printed circuit boards directly opposite the 40 MHz digital chips feasible. The readout electronics for the barrel occupies a potentially important part of the active tracker volume and an aggressive effort has been made to make it as compact as possible. Utilizing a single board for both analog and digital ASICS a 0.1 cm /sup 3/ per channel volume...

Noise and Spurious Tones Management Techniques for Multi-GHz RF-CMOS Frequency Synthesizers Operating in Large Mixed Analog-Digital SOCs

Directory of Open Access Journals (Sweden)

Maxim Adrian

2006-01-01

Full Text Available This paper presents circuit techniques and power supply partitioning, filtering, and regulation methods aimed at reducing the phase noise and spurious tones in frequency synthesizers operating in large mixed analog-digital system-on-chip (SOC. The different noise and spur coupling mechanisms are presented together with solutions to minimize their impact on the overall PLL phase noise performance. Challenges specific to deep-submicron CMOS integration of multi-GHz PLLs are revealed, while new architectures that address these issues are presented. Layout techniques that help reducing the parasitic noise and spur coupling between digital and analog blocks are described. Combining system-level and circuit-level low noise design methods, low phase noise frequency synthesizers were achieved which are compatible with the demanding nowadays wireless communication standards.

Dual adjacency matrix : exploring link groups in dense networks

NARCIS (Netherlands)

Dinkla, K.; Henry Riche, N.; Westenberg, M.A.

2015-01-01

Node grouping is a common way of adding structure and information to networks that aids their interpretation. However, certain networks benefit from the grouping of links instead of nodes. Link communities, for example, are a form of link groups that describe high-quality overlapping node

Converting analog interpretive data to digital formats for use in database and GIS applications

Science.gov (United States)

Flocks, James G.

2004-01-01

There is a growing need by researchers and managers for comprehensive and unified nationwide datasets of scientific data. These datasets must be in a digital format that is easily accessible using database and GIS applications, providing the user with access to a wide variety of current and historical information. Although most data currently being collected by scientists are already in a digital format, there is still a large repository of information in the literature and paper archive. Converting this information into a format accessible by computer applications is typically very difficult and can result in loss of data. However, since scientific data are commonly collected in a repetitious, concise matter (i.e., forms, tables, graphs, etc.), these data can be recovered digitally by using a conversion process that relates the position of an attribute in two-dimensional space to the information that the attribute signifies. For example, if a table contains a certain piece of information in a specific row and column, then the space that the row and column occupies becomes an index of that information. An index key is used to identify the relation between the physical location of the attribute and the information the attribute contains. The conversion process can be achieved rapidly, easily and inexpensively using widely available digitizing and spreadsheet software, and simple programming code. In the geological sciences, sedimentary character is commonly interpreted from geophysical profiles and descriptions of sediment cores. In the field and laboratory, these interpretations were typically transcribed to paper. The information from these paper archives is still relevant and increasingly important to scientists, engineers and managers to understand geologic processes affecting our environment. Direct scanning of this information produces a raster facsimile of the data, which allows it to be linked to the electronic world. But true integration of the content with

Meta-path based heterogeneous combat network link prediction

Science.gov (United States)

Li, Jichao; Ge, Bingfeng; Yang, Kewei; Chen, Yingwu; Tan, Yuejin

2017-09-01

The combat system-of-systems in high-tech informative warfare, composed of many interconnected combat systems of different types, can be regarded as a type of complex heterogeneous network. Link prediction for heterogeneous combat networks (HCNs) is of significant military value, as it facilitates reconfiguring combat networks to represent the complex real-world network topology as appropriate with observed information. This paper proposes a novel integrated methodology framework called HCNMP (HCN link prediction based on meta-path) to predict multiple types of links simultaneously for an HCN. More specifically, the concept of HCN meta-paths is introduced, through which the HCNMP can accumulate information by extracting different features of HCN links for all the six defined types. Next, an HCN link prediction model, based on meta-path features, is built to predict all types of links of the HCN simultaneously. Then, the solution algorithm for the HCN link prediction model is proposed, in which the prediction results are obtained by iteratively updating with the newly predicted results until the results in the HCN converge or reach a certain maximum iteration number. Finally, numerical experiments on the dataset of a real HCN are conducted to demonstrate the feasibility and effectiveness of the proposed HCNMP, in comparison with 30 baseline methods. The results show that the performance of the HCNMP is superior to those of the baseline methods.

Fieldbus: technology application in a 60Co sterilization plant

International Nuclear Information System (INIS)

Karam, D.; Sampa, M.H.O.; Rela, P.R.

2000-01-01

Process instrumentation was made by pressure signals in the 1940s. In the 1960s, 4-20 mA analogue signals were introduced. The development of digital processors in the 1970s sparked the use of computers to monitor and control instruments from a central point. In the 1980s smart sensors were developed and implemented in digital control, microprocessor environments. Fieldbus is a generic-term that describes a new digital communications network. The network is a digital, bi-directional, multidrop, serial-bus, and communications network used to link isolated field devices, such as controllers, transducers, actuators and sensors. Fieldbus technology may improve quality, reduce costs and increase efficiency because information is transmitted digitally without analog to digital or digital to analog converters, which also minimizes hardware errors. Fieldbus communication is based on two-wire communication, interconnecting all the components in the system. This paper introduces Fieldbus technology in a 60 Co sterilization plant

Analytic analysis of auxetic metamaterials through analogy with rigid link systems

Science.gov (United States)

Rayneau-Kirkhope, Daniel; Zhang, Chengzhao; Theran, Louis; Dias, Marcelo A.

2018-02-01

In recent years, many structural motifs have been designed with the aim of creating auxetic metamaterials. One area of particular interest in this subject is the creation of auxetic material properties through elastic instability. Such metamaterials switch from conventional behaviour to an auxetic response for loads greater than some threshold value. This paper develops a novel methodology in the analysis of auxetic metamaterials which exhibit elastic instability through analogy with rigid link lattice systems. The results of our analytic approach are confirmed by finite-element simulations for both the onset of elastic instability and post-buckling behaviour including Poisson's ratio. The method gives insight into the relationships between mechanisms within lattices and their mechanical behaviour; as such, it has the potential to allow existing knowledge of rigid link lattices with auxetic paths to be used in the design of future buckling-induced auxetic metamaterials.

Based on the Network Technology of Digital Campus Design and Analysis

Directory of Open Access Journals (Sweden)

Guo Hongbin

2016-09-01

Full Text Available In recent years, in order to meet the trend of popularization of higher education, expanding the scale of Chinese colleges and universities, and lead to university campuses scattered teaching resources, and information to be slow, poor accuracy and efficiency of the office problems have emerged. The construction of digital campus is not only working for the university scientific research, management provides a fast and convenient information service, and realize the education space and time, teaching contents, means and forms of further opening, largely improves the ability of teaching and scientific research ability and management level. This article through to the digital campus in the process of planning and design requirements, puts forward the conception and design of the construction of the digital campus network, then the digital campus network topology, design of core network, IP address assignment has carried on the discussion a rough. For the design of the digital campus construction provides a draft plan.

Implementation considerations for digital control systems in power plants: Final report

International Nuclear Information System (INIS)

Shah, S.C.; Lehman, L.L.; Sarchet, M.M.

1988-09-01

Conversion of nuclear power plants fron analog to digital control systems will require careful design, testing, and integration of the control algorithms, the software which implements the algorithms, the digital instrumentation, the digital communications network, and analog/digital device interfaces. Digital control systems are more flexible than their analog counterparts, and therefore greater attention must be paid by the customer to all stages of the control system design process. This flexibility also provides the framework for development of significant safety and reliability are inherant aspects of the chosen design processes. Digital control algorithms are capable of improving their performance by on-line self-tuning of the control parameters. It is therefore incumbant on system designers to choose self-tuning algorithms for power plant control. Implementation of these algorithms in software required a careful software design and development process to minimize errors in interpretation of the engineering design and prevent the inclusion of programming errors during software production. Digital control system and communications software must exhibit sufficient ''fault tolerance'' to maintain some level of safe plant operation or execute a safe plant shutdown in the event of both hard equipment failures and the appearance of software design faults. A number of standardized digital communications protocols are available to designers of digital control systems. These standardized digital communications protocols provide reliable fault tolerant communication between all digital elements of the plant control system and can be implemented redundantly to further enhance power plant operational safety. 5 refs., 11 figs., 1 tab

Ionizing secondary radiation generated by analog radiological and digital coronary cine angiographic equipment. Influence of external protection devices

International Nuclear Information System (INIS)

Ramirez N, Alfredo; Farias Ch, Eric; Silva J, Ana Maria; Leyton L, Fernando; Oyarzun C, Carlos; Ugalde P, Hector; Dussaillant, Gaston; Cumsille G, Angel

2000-01-01

Exposure to ionizing radiation is a know hazard of radiological procedures. Aim: to compare the emission of secondary ionizing radiation from two coronary angiographic equipments, one with digital and the other with analog image generation. To evaluate the effectiveness of external radiological protection devices. Material and methods: environmental and fluoroscopy generated radiation in the cephalic region of the patient was measured during diagnostic coronary angiographies. Ionizing radiation generated in anterior left oblique protection (ALO) and anterior right oblique protection (ARO) were measured with and without leaded protections. In 19 patients (group 1), a digital equipment was used and in 21 (group 2), an analog equipment. Results: header radiation for group 1 and 2 was 1194±337 and 364±222 μGray/h respectively (p≤0.001). During fluoroscopy and with leaded protection generated radiation for groups 1 and 2 was 612±947 and 70±61μGray/h respectively (p≤0.001). For ALO projection, generated for groups 1 and 2 was 105±47 and 71±192 μGray/h respectively (p≤0.001). During filming the radiation for ALO projection for groups 1 and 2 was 7252±9569 and 1671±2038 μGray/h respectively (p=0.03). Out of the protection zone, registered radiation during fluoroscopy for groups 1 and 2 was 2800±1741 and 1318±954 μGray/h respectively (p≤0.001); during filming, the figures were 15500±5840 and 18961±10599 μGray/h respectively (NS). Conclusions: digital radiological equipment has a lower level of ionizing radiation emission than the analog equipment

Application of digital sampling techniques to particle identification in scintillation detectors

International Nuclear Information System (INIS)

Bardelli, L.; Bini, M.; Poggi, G.; Taccetti, N.

2002-01-01

In this paper, the use of a fast digitizing system for identification of fast charged particles with scintillation detectors is discussed. The three-layer phoswich detectors developed in the framework of the FIASCO experiment for the detection of light charged particles (LCP) and intermediate mass fragments (IMF) emitted in heavy-ion collisions at Fermi energies are briefly discussed. The standard analog electronics treatment of the signals for particle identification is illustrated. After a description of the digitizer designed to perform a fast digital sampling of the phoswich signals, the feasibility of particle identification on the sampled data is demonstrated. The results obtained with two different pulse shape discrimination analyses based on the digitally sampled data are compared with the standard analog signal treatment. The obtained results suggest, for the present application, the replacement of the analog methods with the digital sampling technique

Fast digital recorders of signal shaping

International Nuclear Information System (INIS)

Meleshko, E.A.

1997-01-01

Methodology of fast digital registration and pulse signals through fast-action analog-to-digital converters is considered. Systems of digital recorders: sampling and storage devices and operational memory units are described. Main attention is paid to developing parallel analog-to-digital converters, making it possible to bring the conversion frequencies up to several gigahertzes are described. Parallel-sequential analog-to-digital converters, combining high action with increased accuracy are also considered. Concrete examples of designing universal and specialized digital signal recorders, applied in experimental physics, are presented. 44 refs., 12 figs

Radiometric calibration of digital cameras using neural networks

Science.gov (United States)

Grunwald, Michael; Laube, Pascal; Schall, Martin; Umlauf, Georg; Franz, Matthias O.

2017-08-01

Digital cameras are used in a large variety of scientific and industrial applications. For most applications, the acquired data should represent the real light intensity per pixel as accurately as possible. However, digital cameras are subject to physical, electronic and optical effects that lead to errors and noise in the raw image. Temperature- dependent dark current, read noise, optical vignetting or different sensitivities of individual pixels are examples of such effects. The purpose of radiometric calibration is to improve the quality of the resulting images by reducing the influence of the various types of errors on the measured data and thus improving the quality of the overall application. In this context, we present a specialized neural network architecture for radiometric calibration of digital cameras. Neural networks are used to learn a temperature- and exposure-dependent mapping from observed gray-scale values to true light intensities for each pixel. In contrast to classical at-fielding, neural networks have the potential to model nonlinear mappings which allows for accurately capturing the temperature dependence of the dark current and for modeling cameras with nonlinear sensitivities. Both scenarios are highly relevant in industrial applications. The experimental comparison of our network approach to classical at-fielding shows a consistently higher reconstruction quality, also for linear cameras. In addition, the calibration is faster than previous machine learning approaches based on Gaussian processes.

A simple structure wavelet transform circuit employing function link neural networks and SI filters

Science.gov (United States)

Mu, Li; Yigang, He

2016-12-01

Signal processing by means of analog circuits offers advantages from a power consumption viewpoint. Implementing wavelet transform (WT) using analog circuits is of great interest when low-power consumption becomes an important issue. In this article, a novel simple structure WT circuit in analog domain is presented by employing functional link neural network (FLNN) and switched-current (SI) filters. First, the wavelet base is approximated using FLNN algorithms for giving a filter transfer function that is suitable for simple structure WT circuit implementation. Next, the WT circuit is constructed with the wavelet filter bank, whose impulse response is the approximated wavelet and its dilations. The filter design that follows is based on a follow-the-leader feedback (FLF) structure with multiple output bilinear SI integrators and current mirrors as the main building blocks. SI filter is well suited for this application since the dilation constant across different scales of the transform can be precisely implemented and controlled by the clock frequency of the circuit with the same system architecture. Finally, to illustrate the design procedure, a seventh-order FLNN-approximated Gaussian wavelet is implemented as an example. Simulations have successfully verified that the designed simple structure WT circuit has low sensitivity, low-power consumption and litter effect to the imperfections.

A new mutually reinforcing network node and link ranking algorithm.

Science.gov (United States)

Wang, Zhenghua; Dueñas-Osorio, Leonardo; Padgett, Jamie E

2015-10-23

This study proposes a novel Normalized Wide network Ranking algorithm (NWRank) that has the advantage of ranking nodes and links of a network simultaneously. This algorithm combines the mutual reinforcement feature of Hypertext Induced Topic Selection (HITS) and the weight normalization feature of PageRank. Relative weights are assigned to links based on the degree of the adjacent neighbors and the Betweenness Centrality instead of assigning the same weight to every link as assumed in PageRank. Numerical experiment results show that NWRank performs consistently better than HITS, PageRank, eigenvector centrality, and edge betweenness from the perspective of network connectivity and approximate network flow, which is also supported by comparisons with the expensive N-1 benchmark removal criteria based on network efficiency. Furthermore, it can avoid some problems, such as the Tightly Knit Community effect, which exists in HITS. NWRank provides a new inexpensive way to rank nodes and links of a network, which has practical applications, particularly to prioritize resource allocation for upgrade of hierarchical and distributed networks, as well as to support decision making in the design of networks, where node and link importance depend on a balance of local and global integrity.

A new mutually reinforcing network node and link ranking algorithm

Science.gov (United States)

Wang, Zhenghua; Dueñas-Osorio, Leonardo; Padgett, Jamie E.

2015-10-01

This study proposes a novel Normalized Wide network Ranking algorithm (NWRank) that has the advantage of ranking nodes and links of a network simultaneously. This algorithm combines the mutual reinforcement feature of Hypertext Induced Topic Selection (HITS) and the weight normalization feature of PageRank. Relative weights are assigned to links based on the degree of the adjacent neighbors and the Betweenness Centrality instead of assigning the same weight to every link as assumed in PageRank. Numerical experiment results show that NWRank performs consistently better than HITS, PageRank, eigenvector centrality, and edge betweenness from the perspective of network connectivity and approximate network flow, which is also supported by comparisons with the expensive N-1 benchmark removal criteria based on network efficiency. Furthermore, it can avoid some problems, such as the Tightly Knit Community effect, which exists in HITS. NWRank provides a new inexpensive way to rank nodes and links of a network, which has practical applications, particularly to prioritize resource allocation for upgrade of hierarchical and distributed networks, as well as to support decision making in the design of networks, where node and link importance depend on a balance of local and global integrity.

A new mutually reinforcing network node and link ranking algorithm

Science.gov (United States)

Wang, Zhenghua; Dueñas-Osorio, Leonardo; Padgett, Jamie E.

2015-01-01

This study proposes a novel Normalized Wide network Ranking algorithm (NWRank) that has the advantage of ranking nodes and links of a network simultaneously. This algorithm combines the mutual reinforcement feature of Hypertext Induced Topic Selection (HITS) and the weight normalization feature of PageRank. Relative weights are assigned to links based on the degree of the adjacent neighbors and the Betweenness Centrality instead of assigning the same weight to every link as assumed in PageRank. Numerical experiment results show that NWRank performs consistently better than HITS, PageRank, eigenvector centrality, and edge betweenness from the perspective of network connectivity and approximate network flow, which is also supported by comparisons with the expensive N-1 benchmark removal criteria based on network efficiency. Furthermore, it can avoid some problems, such as the Tightly Knit Community effect, which exists in HITS. NWRank provides a new inexpensive way to rank nodes and links of a network, which has practical applications, particularly to prioritize resource allocation for upgrade of hierarchical and distributed networks, as well as to support decision making in the design of networks, where node and link importance depend on a balance of local and global integrity. PMID:26492958

23rd workshop on Advances in Analog Circuit Design

CERN Document Server

Baschirotto, Andrea; Makinwa, Kofi

2015-01-01

This book is based on the 18 tutorials presented during the 23rd workshop on Advances in Analog Circuit Design.  Expert designers present readers with information about a variety of topics at the frontier of analog circuit design, serving as a valuable reference to the state-of-the-art, for anyone involved in analog circuit research and development.    • Includes coverage of high-performance analog-to-digital and digital to analog converters, integrated circuit design in scaled technologies, and time-domain signal processing; • Provides a state-of-the-art reference in analog circuit design, written by experts from industry and academia; • Presents material in a tutorial-based format.

Link overlap, viability, and mutual percolation in multiplex networks

International Nuclear Information System (INIS)

Min, Byungjoon; Lee, Sangchul; Lee, Kyu-Min; Goh, K.-I.

2015-01-01

Many real-world complex systems are best modeled by multiplex networks. The multiplexity has proved to have broad impact on the system’s structure and function. Most theoretical studies on multiplex networks to date, however, have largely ignored the effect of the link overlap across layers despite strong empirical evidences for its significance. In this article, we investigate the effect of the link overlap in the viability of multiplex networks, both analytically and numerically. After a short recap of the original multiplex viability study, the distinctive role of overlapping links in viability and mutual connectivity is emphasized and exploited for setting up a proper analytic framework. A rich phase diagram for viability is obtained and greatly diversified patterns of hysteretic behavior in viability are observed in the presence of link overlap. Mutual percolation with link overlap is revisited as a limit of multiplex viability problem, and the controversy between existing results is clarified. The distinctive role of overlapping links is further demonstrated by the different responses of networks under random removals of overlapping and non-overlapping links, respectively, as well as under several link-removal strategies. Our results show that the link overlap facilitates the viability and mutual percolation; at the same time, the presence of link overlap poses a challenge in analytical approaches to the problem

Transitioning from analog to digital communications: An information security perspective

Science.gov (United States)

Dean, Richard A.

1990-01-01

A summary is given of the government's perspective on evolving digital communications as they affect secure voice users and approaches for operating during a transition period to an all digital world. An integrated architecture and a mobile satellite interface are discussed.

A digital silicon photomultiplier with multiple time-to-digital converters

Energy Technology Data Exchange (ETDEWEB)

Garutti, Erika [University Hamburg (Germany); Silenzi, Alessandro [DESY, Hamburg (Germany); Xu, Chen [DESY, Hamburg (Germany); University Hamburg (Germany)

2013-07-01

A silicon photomultiplier (SiPM) with pixel level signal digitization and column-wise connected time-to-digital converters (TDCs) has been developed for an endoscopic Positron Emission Tomography (PET) detector. A digital SiPM has pixels consist of a single photon avalanche diode (SPAD) and circuit elements to optimize overall dark counts and temporal response. Compared with conventional analog SiPM, digital SiPM's direct signal route from SPAD to TDC improves single photon time resolution. In addition, using multiple TDCs can perform the statistical estimation of the time-of-arrival in multiple photon detection case such as readout of scintillation crystals. Characterization measurements of the prototype digital SiPM and a Monte-Carlo simulation to predict the timing performance of the PET detector are shown.

Toward a 62.5 MHz analog virtual pipeline integrated data acquisition system

International Nuclear Information System (INIS)

Kleinfelder, S.A.; Levi, M.; Milgrome, O.

1991-01-01

Requirements of analog pipeline memories at the SSC are reviewed and the concept of virtual pipelines is introduced. Design details and test results of several new custom analog and digital integrated circuits implementing sections of the virtual multiple pipeline (VMP) scheme are provied. These include serial, random access and simultaneous read and write random access analog storage and retrieval circuits, a 100 MHz systolic variable depth digital pipeline, and a prototye 32 μs, 12 bit serial analog to digital converter. (orig.)

Deflating link buffers in a wireless mesh network

KAUST Repository

Jamshaid, Kamran; Shihada, Basem; Showail, Ahmad; Levis, Philip

2014-01-01

We analyze the problem of buffer sizing for backlogged TCP flows in 802.11-based wireless mesh networks. Our objective is to maintain high network utilization while providing low queueing delays. Unlike wired networks where a single link buffer feeds a bottleneck link, the radio spectral resource in a mesh network is shared among a set of contending mesh routers. We account for this by formulating the buffer size problem as sizing a collective buffer distributed over a set of interfering nodes. In this paper we propose mechanisms for sizing and distributing this collective buffer among the mesh nodes constituting the network bottleneck. Our mechanism factors in the network topology and wireless link rates, improving on pre-set buffer allocations that cannot optimally work across the range of configurations achievable with 802.11 radios. We evaluate our mechanisms using simulations as well as experiments on a testbed. Our results show that we can reduce the RTT of a flow by 6× or more, at the cost of less than 10% drop in end-to-end flow throughput.

Deflating link buffers in a wireless mesh network

KAUST Repository

Jamshaid, Kamran

2014-05-01

We analyze the problem of buffer sizing for backlogged TCP flows in 802.11-based wireless mesh networks. Our objective is to maintain high network utilization while providing low queueing delays. Unlike wired networks where a single link buffer feeds a bottleneck link, the radio spectral resource in a mesh network is shared among a set of contending mesh routers. We account for this by formulating the buffer size problem as sizing a collective buffer distributed over a set of interfering nodes. In this paper we propose mechanisms for sizing and distributing this collective buffer among the mesh nodes constituting the network bottleneck. Our mechanism factors in the network topology and wireless link rates, improving on pre-set buffer allocations that cannot optimally work across the range of configurations achievable with 802.11 radios. We evaluate our mechanisms using simulations as well as experiments on a testbed. Our results show that we can reduce the RTT of a flow by 6× or more, at the cost of less than 10% drop in end-to-end flow throughput.