Programmable Function Research Articles

Design and Evaluation of a Massively Parallel Processor Based on Matrix Architecture

This paper describes the design and evaluation of a massively parallel processor base on Matrix architecture which is suitable for portable multimedia applications. The proposed architecture in this paper achieves 40GOPS of 16-bit fixed-point additions at 200MHz clock frequency and 250 mW power dissipation. In addition, 1 M-bit SRAM for data registers and 2,048 2-bit processing elements connected by a flexible switching network are integrated in 3.1 mm 2 in 90 nm low-power CMOS technology. The energy-efficient Matrix architecture supports 2,048-way parallel operations and the programmable functions required for multimedia SoCs.

Video: From Technology to Medium

In this article I propose to discuss video in two ways. First, I will examine video as an electronic technology of signal processing and transmission that shares these properties with other electronic media, notably television. Second, I understand video as a medium in its own right that—like any other medium—develops step by step from the emergence of a novel technology and through the articulation of a specific media language and semiotic system to successfully establish an aesthetic vocabulary, in this case specific to the videographic capacities of electronic signal processing. Once such a media-specific set of means of expression is achieved, video becomes a medium that can be distinguished from other, already existing media. The development from technology to medium also demonstrates that video has some features of analogue recording in common with film and shares processes of both signal-encoded information and transmission with television, but it also incorporates programmable functions in image processors that closely connect to digital programming in computers. I wish to focus on the matter of specificity from two angles: the first is the development from technology to medium, the second is the position of video in the context of analogue and digital media forms and the conceptual linkage among video, analogue processors, and digital computers.1

Molecular Manipulation Based on Allosteric Crown-Appended Units and Related Systems

Synthesis of many potentially useful molecular units by chemists promotes the development of methods for constructing supramolecular architectures. Indeed, programmed supramolecular interactions play crucial roles in the preparation of well-defined nanoscale assemblies. This review highlights successful approaches in designing for specific functions systematically. The incorporation and synergistic communication of conformation-switchable segments into molecules bears great promise. Allostery, which is often observed in naturally occurring proteins, provides a hint for molecular manipulation. In supramolecular chemistry crown ethers can serve not only as substrate-binding sites but also as function-tuning sites. With the combination of synthetic versatility and well-tailored design, diverse capabilities (molecular recognition, catalytic properties, chirality, actuation, and so on) become possible at the molecular or mesoscopic level. The synthetic preparation of advanced molecular units allows the systems to become smarter, and promise nanosystems with programmable functions. This review considers mainly the use of crown ethers which act as anchoring as well as allosteric sites, from the standpoint of design for molecular manipulation. It also gives a brief discussion of recent progress in molecular manipulation, based on related systems. The "synthetic systems" described in the present review should contribute to not only to more elaborate "chemical systems", but also to the evolving field of "molecular machinery", that can utilize these systems.

Programmable vector point-spread function engineering

We use two nematic liquid crystal spatial light modulators (SLM's) to control the vector point spread function (VPSF) of a 1.3 numerical aperture (NA) microscope objective. This is achieved by controlling the polarization and relative phase of the electric field in the objective's pupil. We measure the resulting VPSF's for several different pupil field polarization states. By using single fluorescent molecules as local field probes, we are able to map out the focal field distributions and polarization purity of the synthesized fields. We report the achieved field purity and address the experimental issues that currently limit it.

CMOS DESIGN OF ANALOG FUZZY SYSTEM

This paper proposes several improved CMOS analog integrated circuits for fuzzy inference system as the general modules, including voltage-mode implementations of minimization circuit, programmable Gaussian-like membership function circuit, and centroid algorithm normalization circuit without using division. A two-input/one-output fuzzy system composed of these circuits is implemented and testified as a nonlinear function approximator. HSPICE simulation results show that the proposed circuits provide characteristics of high operation capacity, simple inference, low power dissipation, and high precision.

Focus on Photonics and Imaging

Focus on Photonics and Imaging

Programmable analogue VLSI implementation for asymmetric sigmoid neural activation function and its derivative

A new CMOS VLSI implementation of an asymmetric programmable sigmoid neural activation function, as well as of its derivative, is presented. It consists of two coupled PMOS and NMOS differential pairs with different programmable bias currents that set the upper and lower limits of the sigmoid. The circuit works in the weak inversion region, for low power consumption and exponential envelope, or in strong inversion to achieve higher speeds. The results obtained from the theoretical transfer function, and from the simulations of the circuit implemented in AMI's 0.35 µm technology, show a very good match.

Unified algorithm to generate Walsh functions in four different orderings and its programmable hardware implementations

This paper presents an algorithm to generate Walsh functions in four different orderings: Hadamard, Harmuth, Paley and strict sequency. By the analysis of the properties and mutual relations among these four orderings, the authors found a unified approach to generate any of the orderings from the primary set of Rademacher functions. By using these properties, the authors developed a programmable Walsh function generator for 64 outputs by both field programmable gate arrays and lookup table cascades to estimate the amount of hardware and performance. Such a programmable Walsh function generator can be used in VLSI testing, CDMA, pattern recognition, as well as image and signal processing.

Using CAVE technology for educating and training residents

Problem: Three-dimensional models are quite common now, but are still restricted to a 2-dimensional view by a screen or beamer. We use CAVE technology for education of complex anatomical findings and for surgical simulation. Methods: We create models by segmentation of datasets using the “3D-Slicer.” For the small structures in the temporal bone we used an experimental cone-beam Volume CT prototype that offers 160 micron isotropic resolutions. The CAVE is a Virtual Reality Center (VRC) which allows real-time visualization of interactive, complex graphical data in a walkable room. The graphical visualization is achieved by rear-panel beamers on 3 walls and a projection surface on the floor. Multiple users can interact in this virtual surrounding with different types of graphical data by rotating, zooming, or performing any programmable function. Results: Teaching pathologic findings or surgical planning in challenging cases are the most common fields of application. We use this technology for students’ and residents’ learning difficult anatomic findings. By simulating different pathways we can experience the changes of the anatomy or pathology, which is presented in its variations to the surgeons’ view. Conclusion: Using CAVE technology for medical imaging is the next step of 3D visualization. Most advantages are in the field of education because of the possibility for several dozen individuals to see 3D models simultaneously and to interact with real patients’ data (in other words, allowing a “hands-on effect”). Significance: By using virtual reality we presume to optimize the learning curve of students and especially residents, who are in the first training stages of acquiring the skill of surgery. Another possibility of training surgeons is to simulate the surgeons’ view through a microscope, which is harder because of the loss of landmarks. Walking around the model helps to train the “mental eye” and improves the surgical skills of young surgeons. Support: None reported.

A Generator for Testing Signals of Electroencephalographs and Electrocardiographs

Testing of electrocardiographic (ECG) and electroencephalographic (EEG) channels of medical devices includes application of: 1) signals of standard (harmonic and meander) waveform used to measure the amplification parameters; 2) simulated electrophysiological signals used to assess the performance of algorithms for recognition and data processing. Standard signals are usually generated using laboratory function generators. Reference ECG and EEG signals can be obtained using programmable function generators (such as GF05), special generators of ECG and EEG signal [5-7], or computer DAC cards with appropriate software. To facilitate testing of ECG and EEG equipment and improve the noise immunity of the signal source, we combined a generator of standard signals and a simulator of electrophysiological signals in the single inexpensive portable device Neirotest7A with self-contained power supply (Fig. 1). The device has the following performance characteristics: − 9 types of test signals (2 standard and 7 special signals); − output signal amplitude, ±1.25, 0.63, or 0.31 V (selected by user); − signal repetition rate is selected by user within a given range (depending on the signal type); − amplitude error, <1.2%; − accuracy of frequency adjustment, ≥99.8%; − output resistance, ≤110 Ω ± 5%; − clock signal output, TTL-compatible; − power supply, AAA galvanic cell; current consumption, ≤14 mA; uninterrupted operation time, ≥100 h; battery discharge indication; automatic switching off; − dimensions, 74 × 49 × 18 mm; − weight (with power supply), ≤50 g. The Neirotest7A device generates the following standard test signals. 1. Harmonic (sinusoidal) signal with a frequency of 0.5 to 99 Hz. This signal is used to determine the degree of nonuniformity of the amplitude–frequency characteristics [4].

Self-tuning of the relationships among rules' components in active databases systems

Active database systems are systems that detect events and trigger actions as a result of this detection. Active capabilities are provided by a set of rules, such that each rule consists of three components (event, condition, and action). A major performance issue in active databases is the issue of relationships among rule components. Current implementations of triggers do not allow flexibility in the selection of transaction policies (partition of rules to transactions); the intertransaction timing policies of rules' components, the intratransaction policies of commit and abort dependencies, and synchronization issues. While these decisions have a substantial impact on the application performance, they are not provided as design primitives; one of the reasons for that is that it is very difficult to manually tune these decisions. In some research prototypes of active databases, these relationships are encapsulated into a set of coupling modes. Each coupling mode represents a combination of decisions about the partition of rule components to transactions, the relative timing within a transaction, and the interrelationships among these transactions. We describe a self-tuning model that operates on a general active database. The optimization model strives to minimize a programmable goal function that reflects the system designer's preferences and the system behavior and the applications' semantics through constraint definitions. The tuning model strives to optimize the mutual relationships among the system rules' components.

A Programmable CMOS Fuzzy Membership Function Generator

This paper presents the architecture and circuit-level details related to hardware implementation of a programmable analog Membership Function Circuit (MFC). Its new architecture and modular approach makes it flexible and easy to expand. The proposed circuit has a wide dynamic input range (3.5 V) and can be modified in a way that the output of the circuit may be in single-ended or differential mode. In addition width, height, position and slope of generated membership functions are easily tunable. Brief tutorials of the circuits introduced by other papers are presented here for comparison. Simulation results are also given using HSPICE software in 0.5μm CMOS technology.

GHz programmable counter with low power consumption

A high-speed programmable counter with a new reloadable D flip-flop which integrates the programmable function to a true-single-phase-clock (TSPC) D flip-flop is presented. The proposed reloadable D flip-flop is able to operate at higher frequencies with lower power consumption compared to the performance of the existing bitcell. The programmable divide-by-N counter implemented with this reloadable D flip-flop using the Chartered 0.18 µm CMOS process is capable of operating up to 2 GHz for a 1.8 V supply voltage with 4.7 mW power consumption.

Poster 201: Stroke rehabilitation in a patient with a cardiac pacemaker for chronic atrial fibrillation: a case report.

Setting: Inpatient stroke rehabilitation hospital. Patient: A 60-year-old man with an artificial pacemaker suffered from cardiogenic cerebral embolism. Case Description: The patient received a pacemaker (ventricular demand inhibited pacemaker with rate-adaptive mode) implantation for chronic bradycardic atrial fibrillation. The pacemaker relieved his congestive heart failure and episodes of Adams-Stokes syndrome. 5 years after the implantation, he suffered a hemorrhagic cerebral embolism, which led to severe disability. He had flaccid left hemiplegia and severe disuse syndrome after prolonged (>4mo) bedrest. He could not sit up and could tilt his head up for less than 2 minutes because of mortal orthostatic intolerance and hypotension and a lack of physiologic Bainbridge reflex. Low endurance of exercise with absolute chronotropic incompetence arrested the rehabilitation. By modulating programmable pacemaker function every 2 weeks, we started to rehabilitate the patient. The programmable function was an optimal or lower rate and a rate-adaptive pacing rate, which included upper sensor rate, activity threshold, reaction time, and recovery time, in response to physical motion and activity. Assessment/Results: Periodic programming of the pacemaker function allowed him to continue rehabilitation. Specifically, we enabled its ability to vary the pacing rate in response to increased physical activity in accordance with progressive rehabilitation programs. After 4 months of rehabilitation, he could sit in a wheelchair for >3 hours without significant orthostatic hypotension and he performed activities of daily living with mild assistance. Discussion: This case emphasizes the importance of examining the function of a previously implanted pacemaker. In accord with varying rehabilitation programs and gradual improvement in physical activities, periodic adjustment of a programmable pacemaker can lead to a better functional outcome. Conclusion: Rate-adaptive pacemaker mode benefited this stroke patient, who had severe orthostatic intolerance and chronotropic incompetence, that is, flaccid hemiplegia and bradycardic atrial fibrillation.

Reasoning about secrecy for active networks

In this paper we develop a language of mobile agents called uPLAN for describing the capabilities of active (programmable) networks. We use a formal semantics for uPLAN to demonstrate how capabilities provided for programming the network can affect the potential flows of information between users. In particular, we formalize a concept of security against attacks on secrecy by an 'outsider' and show how basic protections are preserved in the presence of programmable network functions.

Flicker produced by harmonics modulation

Flicker effect caused by voltage harmonics modulation is discussed. Simple functions are used to show that harmonic components, despite satisfying the specific harmonic limits, may produce flicker due to combined amplitude modulation (AM). Computer simulations, based on the International Electro-technical Commission (IEC) methodology, are numerically validated and then applied to calculate the instantaneous flicker sensation, resulting from different combinations of harmonics modulation. The results are also confirmed in laboratory tests using a flickermeter to measure the flicker levels obtained by synthesizing the same type of signals on a programmable function generator.

A software controlled pulse compression technique applied to ultrasonic non‐destructive testing

The pulse compression technique, which is widely used in Radar systems, has been successfully used in ultrasonic nondestructive testing (NDT) by hardware methods for real time display of the testing result to improve the signal‐to‐noise ratio (SNR). This technique transmits a linear frequency modulated signal and compresses the received signal by time delay of a linear frequency function. Therefore, the energy of the signal can be preserved during compression; the narrow output signal will have a large increase in amplitude. In this study, a programmable and flexible software method controlling a simple signal generation hardware system is proposed for the pulse compression technique in the ultrasonic NDT. A frequency‐swept ultrasonic signal under control of a programmable arbitrary function generator is transmitted to scan the specimen. The received signal is cross‐correlated with the frequency‐swept ultrasonic signal to compress the signal, and the signal buried in the noise can be successfully identified after the cross‐correlation. The methods are illustrated by examples.

Logic synthesis and circuit modeling of a programmable logic gate based on controlled quenching of series-connected negative differential resistance devices

The circuit concept of programmable logic gates based on the controlled quenching of series-connected negative differential resistance (NDR) devices is introduced, along with the detailed logic synthesis and circuit modeling. At the rising edge of a clocked supply voltage, the NDR devices are quenched in the ascending order of peak currents that can be reordered by the control gates and input gates biases, thus, providing programmable logic functions. The simulated results agree well with the experimental demonstration of the programmable logic gate fabricated by a monolithic integrated resonant tunneling diode/high electron mobility transistor technology.

Programmable function generators––I: base five-bar mechanism

The concept of programmable function generator mechanisms is introduced here. A multi-degree of freedom (DOF) closed chain mechanism can be termed a programmable mechanism, if the motion corresponding to at least one DOF is controlled to influence the output motion. The five-bar, two-DOF planar mechanism, which constitutes a base for synthesizing the simplest programmable function generator mechanisms, is studied here. Design considerations, such as determinate kinematics, link dimensions, selection of coupler-point and control-input, are discussed.

Programmable function generators––II: seven-bar translatory-output mechanism

A translating-output programmable function generator, obtained by adding a RPP dyad to the base triple-crank, five-bar mechanism (FBM), is considered here. The FBM is designed for compactness while avoiding mode singularities and the coupler point selection is based on space utilization ratio. Design variables are identified and issues of generating optimal coupler point trajectories are discussed. Simulation results are presented for minimizing the peak servo acceleration, the peak servo torque and the RMS servo torque.