Alias types for “environment-aware” computations

In previous work with Bono we introduced a calculus for modelling “environment-aware” computations, that is computations that adapt their behavior according to the capabilities of the environment. The calculus is an imperative, object-based language (with extensible objects and primitives for discriminating the presence or absence of attributes of objects) equipped with a small-step operational semantics.In this paper we define a type and effect system for the calculus. The typing judgements specify, via constraints, the shape of environments which guarantees the correct execution of expressions and the typing rules track the effect of expression evaluation on the environment. The type and effect system is sound w.r.t. the operational semantics of the language.     

Transformation ratio of “ring-dot” planar piezoelectric transformer

A piezoelectric transformer (PT) is a device, which can be used for transforming an ac voltage via ultrasonic vibrations. The best characteristics are achieved in the vicinity of mechanical vibration resonance. “Ring-dot” type design of homogeneously poled disk PT was originally proposed by Berlincourt. Only experimental data were published in preceding studies. An analytical continuum model is presented in this work. The effects of dimensions, material properties and electrical load on the voltage gain as well as on the efficiency are calculated. Hard lead zirconate titanate ceramics (PZT, APC841 type) was used for sample fabrication. Studied PTs typically attain transformation ratio equal 20 without load. For load impedance around 5 kΩ, the observed efficiency was above 90%, whereas the transformation ratio dropped down to the values around 2. The model correspondence with experiment is limited by employed approximations. Model limitations are discussed with respect to experimental data.     

No-Longer-Foreign: Teaching an ML compiler to speak C “natively”

We present a new foreign-function interface for SML/NJ. It is based on the idea of data-level interoperability—the ability of ML programs to inspect as well as manipulate C data structures directly.The core component of this work is an encoding of the almost² complete C type system in ML types. The encoding makes extensive use of a “folklore” typing trick, taking advantage of ML's polymorphism, its type constructors, its abstraction mechanisms, and even functors. A small low-level component which deals with C struct and union declarations as well as program linkage is hidden from the programmer's eye by a simple program-generator tool that translates C declarations to corresponding ML glue code.     

Corrections to “Basins of Attraction in Fully Asynchronous Discrete-Time Discrete-State Dynamic Networks” [Mar 06 397-408]

This paper brings a correction to the formulation of the basins of fixed-point states of fully asynchronous discrete-time discrete-state dynamic networks presented in the above titled paper (ibid., vol. 17, no. 2, pp. 397-408, Mar 06). In our subsequent works on totally asynchronous systems, we have discovered that the formulation given in that previous paper lacks an additional condition. We present in this paper why the previous formulation is incomplete and give the correct formulation.     

“Communication to: A Closed-Form Expression for the Uncertainty in Odometry Position Estimate of an Autonomous Vehicle”

The uncertainty of the odometry position estimate for a given vehicle can be obtained from the definition of the covariance matrix by using its kinematic model as well as its sensory system data. This communication item extends a previous work in by giving the appropriate guidelines so as to compute the cross-covariance terms between the previous position estimate and the actual increments of position. This is necessary in general because the orientation errors on the robot's previous position will affect the calculation of the actual increments of position.      

Comment and Further Result on “Fault Detection and Isolation Method Based on H−/H∞ Unknown Input Observer Design in Finite Frequency Domain”

This paper considers the work entitled “Fault detection and isolation method based on H_?/H_∞ unknown input observer design in finite frequency domain”, published previously in the Asian Journal of Control. We point out that some design matrices in the above mentioned article have no effect on the design result. Furthermore, we show that the conditions proposed therein for H_∞ design are conservative and propose an improved design method.     

Error estimates for least squares finite element methods

A least squares finite element scheme for a boundary value problem associated with a second-order partial differential equation is considered. Previous work on this subject is generalized and improved by considering a larger class of equations, by working in the natural context, without additional smoothness conditions, and by deriving error estimates, not only in the H¹-norm and the H_div-norm, but also in the L₂-norm. Some of these estimates are sharpened by using finite element spaces with the grid decomposition property. The error estimates are supported by numerical results which extend previous numerical work.     

Nonlinear state feedback for ℓ optimal control

This paper considers ℓ¹ optimal control problems with full state feedback. In contrast to ^∞ optimal control, previous work has shown that linear ℓ¹ optimal controllers can be dynamic and arbitrarily high order. However, this paper shows that continuous memoryless nonlinear state feedback perform as well as dynamic linear state feedback. The derivation, which is nonconstructive, relies on concepts from viability theory.     

Expert system for problem solving in distance university education: The successful case of the subject “operations management”

Acquiring the skills needed to solve certain types of problems is one of the main challenges of distance university education, demanding extra motivation from students to tackle it. New technology should be one of our great allies in addressing these problems. This article proposes an expert system with a web‐based problem‐solving simulator for a multidevice environment in order to allow students to access an unlimited number of problems with their corresponding solutions, immediately, anytime and anywhere. The types of problems that can be used are those based on quantitative methods with a fixed methodology to be followed. A successful case study was carried out for the subject Operations Management at the Distance University of Madrid (UDIMA), with three different problem simulators having been developed. The results were very satisfactory compared with previous academic years in terms of motivation. A decrease in students that did not sit the final examination was observed, as was an increase in the number of visits to the Moodle classroom. Students also responded positively in their assessments of the initiative.     

High‐resolution and high‐brightness full‐colour “Silicon Display” for augmented and mixed reality

High‐brightness micro‐LED display bonded onto silicon backplane has been successfully demonstrated. The 0.38‐inch full‐colour active matrix LED microdisplay system consists of 352 × 198 pixels. Each pixel is 24 μm square composed of red, green, and blue (RGB) subpixels corresponding to a pixel resolution of 1053 ppi. Quantum‐dot materials are formed on III‐nitride blue micro‐LED array to convert blue light into red and green for full‐colour operation. We have confirmed that this microdisplay, which we call “Silicon Display” has wide colour gamut exceeding 120% of sRGB. We describe the advantage of this colour‐converting approach for the full‐colour micro‐LEDs. Progress toward higher resolution is also described. Brightness of more than 30 000 cd/m² has been confirmed at a driving current density of 4 A/cm² for 3000 ppi blue monochrome micro‐LED prepared for full‐colour Silicon Display. We believe our “Silicon Display” is ideally suited for near‐to‐eye displays for augmented and mixed reality.     

Remarks on “Measuring Ambiguity in the Evidence Theory”

In a recent paper, a functional AM (ambiguity measure) is introduced and an attempt is made to show that this functional qualifies as a measure of total aggregated uncertainty in the Dempster-Shafer theory. We show that this attempt fails due to a particular error in the proof of one of the principal theorems in the paper. Some additional remarks are made regarding recent research pertaining to the subject of the discussed paper.     

Comments on “self-tuning adaptive control of cement raw material blending”

In a recent paper Keviczky and co-workers (1978) use results of previous papers (Keviczky and Hetthessy, 1977; Hetthessy, Haber and Keviczky (1975) to present the MIMO-ST-MV and the MIMO-ST-MV-RAFT used in cement industries. In this correspondence an algebraic mistake is shown to have taken place in Keviczky and Hetthessy (1977). Accordingly, the representation in Keviczky and co-workers (1978) of the regulator parameter matrix is not of the minimum variance type.     

“Vague-to-Crisp” Neural Mechanism of Perception

This brief describes neural modeling fields (NMFs) for object perception, a bio-inspired paradigm. We discuss previous difficulties in object perception algorithms encountered since the 1950s, and describe how NMF overcomes these difficulties. NMF mechanisms are compared to recent experimental neuroimaging observations, which have demonstrated that initial top-down signals are vague and during perception they evolve into crisp representations matching the bottom-up signals from observed objects. Neural and mathematical mechanisms are described and future research directions outlined.      

CORRECTION TO “SINGULARITY COMPUTATION FOR ITERATIVE CONTROL OF NONLINEAR AFFINE SYSTEMS”

The ball‐on‐plate example in the above paper by the authors [3] contains a mistake in the vector field. This note presents the singularity result of the corrected vector field.     

Comments on “Discrete-Time Adaptive Backstepping Nonlinear Control via High-Order Neural Networks”

The purpose of this comment is to point out some mistakes in the above paper. It is shown that the main results of the paper cannot stand in general. Also, it is pointed out that after some corrections, the proposed control algorithm is still applicable to a more simple system. For simplicity, all the symbols in this comment are the same as those in the above paper.     

Comments on “A class of proportional-integral sliding mode control with application to active suspension system”

In this note, we first show that Theorem 2 in the above paper is incorrect. Then, we also show that Theorem 1 is not enough to support the claim in the above paper that the proportional-integral sliding mode control method is more robust than the linear quadratic regulator method when applying on the active suspension system with mismatched uncertainties.     

Comments on “Generalized Lyapunov Equation Approach to State-Dependent Stochastic Stabilization/ Detectability Criterion”

This note gives a correct proof for the first part of Theorem 3.2 in the above paper, which is an important theorem of the above paper.      

Who are “stinkybug” and “Packerfan4”? Email Pseudonyms and Participants’ Perceptions of Demography,Productivity, and Personality

This study explores whether in the absence of face‐to‐face interaction individuals rely on mediated “clues” for constructing their perceptions of other individuals. Specifically, we assess whether individuals use the information in email usernames to create basic assumptions about the sender of a message. Ninety‐four male and 206 female participants completed self‐report surveys asking their perceptions of an instructor‐assigned, fictional group member including sex, age, race, and work productivity. A majority of participants assigned biological sex, ethnicity, and age to the fictional member. Participants often identified the creative emails as belonging to Caucasian males, while plain usernames were unknown and perceived as significantly more productive. The majority of participants chose to delete the message, listing lack of recognition as a reason for avoidance. These results suggest that email usernames may shape perceptions when other, nonverbal cues are absent.     

Visualizing “typical” and “exotic” Internet traffic data

The threat of cyber attacks motivates the need to monitor Internet traffic data for potentially abnormal behavior. Due to the enormous volumes of such data, statistical process monitoring tools, such as those traditionally used on data in the product manufacturing arena, are inadequate. “Exotic” data may indicate a potential attack; detecting such data requires a characterization of “typical” data. We devise some new graphical displays, including a “skyline plot,” that permit ready visual identification of unusual Internet traffic patterns in “streaming” data, and use appropriate statistical measures to help identify potential cyberattacks. These methods are illustrated on a moderate-sized data set (135,605 records) collected at George Mason University.     

Comments and improvement on “Robust control of state delayed systems with polytopic type uncertainties via parameter-dependent Lyapunov functionals”

The errors are pointed out in the above paper. And then, a new delay-dependent condition is presented for the robust stability of uncertain time-delay systems, which is an improvement on the corresponding results in the above paper.