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.     

The formation of learners’ semiosphere by authentic inquiry with an integrated learning object “Young Scientist”

An integrated learning object, a web-based inquiry environment “Young Scientist” for basic school level is introduced by applying the semiosphere conception for explaining learning processes. The study focused on the development of students’ (n = 30) awareness of the affordances of learning objects (LO) during the 3 inquiry tasks, and their ability of dynamically reconstructing meanings in the inquiry subtasks through exploiting these LO affordances in “Young Scientist”. The problem-solving data recorded by the inquiry system and the awareness questionnaire served as the data-collection methods.It was demonstrated that learners obtain complete awareness of the LO affordances in an integrated learning environment only after several problem-solving tasks. It was assumed that the perceived task-related properties and functions of LOs depend on students’ interrelations with LOs in specific learning contexts. Learners’ overall awareness of certain LO affordances, available in the inquiry system “Young Scientist”, developed with three kinds of patterns, describing the hierarchical development of the semiosphere model for learners. The better understanding of the LO affordances, characteristic to the formation of the functioning semiosphere, was significantly related to the advanced knowledge construction during these inquiry subtasks that presumed translation of information from one semiotic system to another. The implications of the research are discussed in the frames of the development of new contextual gateways for learning with virtual objects. It is assumed that effective LO-based learning has to be organized through pedagogically constrained gateways by manifesting certain LO affordances in the context in order to build up the dynamic semiosphere model for learners.     

“Chaotic relaxation” in concurrently asynchronous neural networks

In this paper we analyze a fundamental issue which directly impacts the scalability of current theoretical neural network models to applicative embodiments, in both software as well as hardware. This pertains to the inherent and unavoidable concurrent asynchronicity of emerging fine-grained computational ensembles and the consequent chaotic manifestations in the absence of proper conditioning. The latter concern is particularly significant since the computational inertia of neural networks in general and our dynamical learning formalisms manifests itself substantially, only in massively parallel hardward—optical, VLSI or opto-electronic. We introduce a mathematical framework for systematically reconditioning additive-type models and derive a neuro-operator, based on the chaotic relaxation paradigm whose resulting dynamics are neither “concurrently” synchronous nor “sequentially” asynchronous. Necessary and sufficient conditions guaranteeing concurrent asynchronous convergence are established in terms of contracting operators. Lyapunov exponents are also computed to characterize the network dynamics and to ensure that throughput-limiting “emergent computational chaos” behavior in models reconditioned with concurrently asynchronous algorithms was eliminated.     

Code Annotation for Safe and Efficient Dynamic Object Resolution

The execution time of object oriented programs can be drastically reduced by transforming “non escaping” objects into a collection of its component scalar data fields. But for languages that support dynamic linking, this kind of optimization (which we call “object resolution”) can usually only be performed at runtime, when the entire program is available for analysis. In such cases, the resulting performance increases will be offset by the additional costs that arise during the analysis and restructuring phases.In this paper, we describe work in progress, which provides an annotation technique that reduces the runtime overhead required for performing object resolutions. Our method performs a partial static escape analysis of each class at compile-time and then annotates the intermediate representation of that class with information which the just-in-time (JIT) compiler can use for object resolution. We apply this technique to the safe TSA intermediate representation, producing a simple extension to safe TSA's type system that guarantees a safe and verifiable transmission of the annotated program.     

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.     

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.     

Analysis of “Salary man” motivation and the will to work (YARUKI)

The Inner Graphic Formula Method (IGF) which was originally conceived by Professor Ishiketa and further developed by him and his associates was used to investigate the motivation of new company employees.

Japanese companies traditionally recruit new employees from senior classes and notify successful candidates of their intention to employ them around the first of January. Since graduation is in March, April first is, then, the first day of work for almost all of these graduates in their new companies.

The investigation period for this study covers the eleven months from January until the middle of November, and therefore includes the three month period after notification but prior to actual work, from January first until March thirty-first, and the first eight month of actual work, from April first to the middle of November. The subjects fell, naturally, into two groups; a “Blue Collar” group and a “White Collar” group.

This paper deals with the motivation of these newly employed workers in general and, specifically, with the difference in motivational tendencies between “Blue Collar” and “White Collar” workers. As expected analysis showed that clear motivational differences appeared.

Motivation in the white collar workers tended to raise after an initial downturn, while a general downward trend was detected for the blue collar workers. White collar worker's attitudes toward themselves and toward their work seemed to change for the better as a result of having the chance to become introspective while plotting the graph and writing the anecdotal responses needed to complete the investigative sheet for this study.     

The “burning ship” and its quasi-Julia sets

By manipulating the imaginary part of the complex-analytic quadratic equation, we obtain, by iteration, a set that we call the “burning ship” because of its appearance. It is an analogue to the Mandelbrot set (M-set). Its nonanalytic “quasi”-Julia sets yield surprizing graphical shapes.     

“Electric” Zip Tips™, Preliminary Results

Induction based fluidics (IBF), a new, simple patented approach for transporting liquids in the micro and the macro world, is discussed. Electric fields are shown to energize liquid/s in a container/s to execute an array of purposes. IBF is shown uniquely to energize N liquids in simple off the shelf devices, inductively. We discuss calibration and other issues, as we demonstrate how simple devices can dispense nanoliters and microliters with high precision and accuracy. Furthermore, we show preliminary single and eight channel data for the Zip Tip™ made by Millipore where the device transports liquids “electrically.” We briefly consider how such new devices, “electric” Zip Tips™, might automate desalting and the placement of digests for MALDI TOF analysis.     

“Pay bursts only once” does not hold for non-FIFO guaranteed rate nodes

We consider end-to-end delay bounds in a network of guaranteed rate (GR) nodes. We demonstrate that, contrary to what is generally believed, the existing end-to-end delay bounds apply only to GR nodes that are FIFO per flow. We show this by exhibiting a counter example. Then, we show that the proof of the existing bounds has a subtle, but important, dependency on the FIFO assumption, which was never noticed before. Finally, we give a tight delay bound that is valid in the non-FIFO case; it is noticeably higher that the existing one. In particular, the phenomenon known as “pay bursts only once” does not apply to non-FIFO nodes. These findings are important in the context of differentiated services. Indeed the existing bounds have been applied to cases where a flow (in the sense of the GR definition) is an aggregate of end-user microflows, and it is not generally true that a router is FIFO per aggregate; thus, the GR node model of a differentiated services router cannot always be assumed to be FIFO per flow.     

Suppression of “salt and pepper” noise based on Youden designs

This paper presents a new class of algorithms based on Youden designs to detect and restore edges present in an image imbedded by mixture or “salt and pepper” noise. The mixture noise consists of a uncorrelated or correlated noisy background plus uncorrelated impulsive noise. The objective is to restore pixels affected by the impulsive part of the mixture noise. The approach is to consider that these pixels have lost their true value and their estimate is obtained via the normal equation that yields the least sum of square error (LSSE). This procedure is known in the literature as “The Missing Value Approach Problem”. The estimates are introduced into the image data and an ANOVA technique based on Youden design is carried out. We introduce Youden designs which are special Symmetric Balanced Incomplete block (SBIB) designs, the pertinent statistical tests and estimates of the factor effects. We derive the estimate of the missing value for the uncorrelated noise environment as well as for the correlated one. The high level of performance of these algorithms can be evaluated visually via the input/output images and objectively via the input/output signal-to-noise ratio (SNR).     

Rush Hour is PSPACE-complete, or “Why you should generously tip parking lot attendants”

Rush Hour is a children's game that consists of a grid board, several cars that are restricted to move either vertically or horizontally (but not both), a special target car, and a single exit on the perimeter of the grid. The goal of the game is to find a sequence of legal moves that allows the target car to exit the grid. We consider a slightly generalized version of the game that uses an n×n grid and assume that we can place the single exit and target car at any location we choose on initialization of the game.

In this work, we show that deciding if the target car can legally exit the grid is PSPACE-complete. Our constructive proof uses a lazy form of dual-rail reversible logic such that movement of “output” cars can only occur if logical combinations of “input” cars can also move. Emulating this logic only requires three types of devices (two switches and one crossover); thus, our proof technique can be easily generalized to other games and planning problems in which the same three primitive devices can be constructed.     

Construction of a hermite rational “Wachspress type” finite element

This paper concerns the construction of a quadrilateral finite element whose interpolation space admits of rational fractions for basis functions of “Wachspress type” [1, 2]. The construction of this finite element, which is in a way the “rational” equivalent of the ADINI finite element[3, 4], is founded on a method analogous to the one used for Serendip degree-two finite element construction in[2]. The study of interpolation error is dealt with in a paper by Apprato, Arcangeli and Gout in this journal “Rational interpolation of Wachspress error estimates”.     

A “mixed” small gain and passivity theorem in the frequency domain

We show that the negative feedback interconnection of two causal, stable, linear time-invariant systems, with a “mixed” small gain and passivity property, is guaranteed to be finite-gain stable. This “mixed” small gain and passivity property refers to the characteristic that, at a particular frequency, systems in the feedback interconnection are either both “input and output strictly passive”; or both have “gain less than one”; or are both “input and output strictly passive” and simultaneously both have “gain less than one”. The “mixed” small gain and passivity property is described mathematically using the notion of dissipativity of systems, and finite-gain stability of the interconnection is proven via a stability result for dissipative interconnected systems.     

Non-linear mechanic and electric behavior of a robot axis with a “harmonic-drive” gear

This paper presents a study of a complete robot axis including the electrical and the mechanical parts. The motorization of the robot arm presented here has been carried out using a DC motor, a “harmonic-drive” type gear system and three control loops (current, speed and position). Each component is studied and modeled taking into account non-linearities such as current limitation, backlash, low rigidity and non-linear friction. The results obtained through computation of the model are compared with measurements on the real arm (motor current and speed) using speed and position loops.     

“To be recorded” analysis in reverse-mode automatic differentiation

The automatic generation of adjoints of mathematical models that are implemented as computer programs is receiving increased attention in the scientific and engineering communities. Reverse-mode automatic differentiation is of particular interest for large-scale optimization problems. It allows the computation of gradients at a small constant multiple of the cost for evaluating the objective function itself, independent of the number of input parameters. Source-to-source transformation tools apply simple differentiation rules to generate adjoint codes based on the adjoint version of every statement. In order to guarantee correctness, certain values that are computed and overwritten in the original program must be made available in the adjoint program. For their determination we introduce a static data-flow analysis called “to be recorded” analysis. Possible overestimation of this set must be kept minimal to get efficient adjoint codes. This efficiency is essential for the applicability of source-to-source transformation tools to real-world applications.     

Justification of new technologies through the use of “cause and effect” analysis: Case of tile replacement at Kennedy space center

This paper presents a case of introducing new technology to a single stage in a maintenance operation composed of sequence of stages. The process - Thermal tile replacement - is a low volume, high value operation. A method for data collection at each stage, to estimate the variability in process quality, cost and duration is presented. The method involves: Identifying key product features, accuracy measure for each, rate of product rejection by feature and the associated probability density functions at each stage. The method relates accuracy variability by feature, “effect” to the contributing stage in the process “cause”. Simulation is used to justify the introduction of a new technology and to predict the percentage of product conformity in a “before” and “after” scenarios for the implementation of the new technology. The simulation model enables the quantification of technology impact on the product quality, overall productivity and the associated cost savings.     

A Calculus for “environment-aware” computation

We present a calculus for modelling “environment-aware” computations, that is computations that adapt their behaviour according to the capabilities of the environment. The calculus is an imperative, object-based language with extensible objects, equipped with a labelled transition semantics. A notion of bisimulation, lifting to computations a correspondence between the capabilities of different environments, is provided. Bisimulation can be used to prove that a program is “cross-environment”, i.e., it has the same behaviour when run in different environments.     

A nexus of Cyber-Geography and Cyber-Psychology: Topos/“Notopia” and identity in hacking

This paper explores the Cyber-Psychological and Cyber-Geographic aspects of hacking and hacktivism. An examination of the literature related to hackers and hacking reveals a complex nexus of spatial (including cyber-spatial such as “Notopia”) and psychological aspects of hacking, from which emerges a central question of how humans perceive and manipulate their cyber-identities. Concealing (real and cyber) identities is typical in hacking. With our progressive acculturation with identity-less and place-less modes of existence, our cyber-identities through time may be studied from within John Locke’s criterion of “memory” and the spatial-geographical criterion of identity.