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.     

Undergraduate students' use of information elicited during e-mail “tutorials”

This study considers those questions posed by students during e-mail “tutorials” to elicit information from “guest lecturers” and the use of that information by students in their essays. The “tutorials” were conducted for students in the U.K. by a “guest lecturer” in France. The “guest lecturer” was accredited as a tutor on the module for which the students were enrolled, and participated in the module by the provision of lecture notes prior to the e-mail tutorials. Data for the study, drawn from a comparative education assignment set for undergraduate students enrolled on the module, comprised surveys of students' perceived IT capabilities and attitudes towards IT, analyses of students' questions and analyses of students' essays. The findings of the study indicate (1) that tutees tend to pose questions to elicit information or clarification rather than to elicit the viewpoint or opinions of the “guest lecturer” and (2) that two-thirds of tutees' essays cited information elicited from the “guest lecturer”.     

“Graphical” Jogthrough: expert based methodology for user interface evaluation, applied in the case of an educational simulation interface

“Walkthrough” and “Jogthrough” techniques are well known expert based methodologies for the evaluation of user interface design. In this paper we describe the use of “Graphical” Jogthrough method for evaluating the interface design of the Network Simulator, an educational simulation program that enables users to virtually build a computer network, install hardware and software components, make the necessary settings and test the functionality of the network. Graphical Jogthrough is a further modification of a typical Jogthrough method, where evaluators' ratings produce evidence in the form of a graph, presenting estimated proportion of users who effectively use the interface versus the time they had to work with it in order to succeed effectiveness. We comment on the question: “What are the possible benefits and limitations of the Graphical Jogthrough method when applied in the case of educational software interface design?” We present the results of the evaluation session, and concluding from our experience we argue that the method could offer designers quantitative and qualitative data for formulating a useful (though rough in some aspects) estimation about the novice–becoming–expert pace that end users might follow when working with the evaluated interface.     

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.     

Information retrieval expert system “matchmaker”

This paper describes the information system used to search for a potential matrimonial partner. The search is based on comparison of the subject's record, which consists of his/her answers to about 400 items of a specially designed questionnaire, to the records of the potential partners. The basic principle of the system is representation of the set of candidates for the client with psychological warnings about potential “conflict zones” in relationships between client and candidate rather than a ranking of candidates based on hypothetical “psychological compatibility” indices.     

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.     

“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.     

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.     

The identification of nonlinear models for process control using tailored “plant-friendly” input sequences

This paper considers certain practical aspects of the identification of nonlinear empirical models for chemical process dynamics. The primary focus is the identification of second-order Volterra models using input sequences that offer the following three advantages: (1) they are “plant friendly;” (2) they simplify the required computations; (3) they can emphasize certain model parameters over others. To provide a quantitative basis for discussing the first of these advantages, this paper defines a friendliness index f that relates to the number of changes that occur in the sequence. For convenience, this paper also considers an additional nonlinear model structure: the Volterra–Laguerre model. To illustrate the practical utility of the input sequences considered here, second-order Volterra and Volterra–Laguerre models are developed that approximate the dynamics of a first-principles model of methyl methacrylate polymerization.     

The characteristics of a “stop–flow” mode of sensor array operation using data with the best classification performance

The paper presents an approach to characterizing a “stop–flow” mode of sensor array operation. The considered operation mode involves three successive phases of sensors exposure: flow (in a stream of measured gas), stop (in zero flow conditions) and recovery (in a stream of pure air). The mode was characterized by describing the distribution of information, which is relevant for classification of measured gases in the response of sensor array. The input data for classifier were the sets of sensors output values, acquired in discrete time moments of the measurement. Discriminant Function Analysis was used for data analysis. Organic vapours of ethanol, acetic acid and ethyl acetate in air were measured and classified. Our attention was focused on data sets which allowed for 100% efficient recognition of analytes. The number, size and composition of those data sets were examined versus time of sensor array response. This methodology allowed to observe the distribution of classification-relevant information in the response of sensor array obtained in “stop–flow” mode. Hence, it provided for the characterization of this mode.     

Factor structure for Young’s Internet Addiction Test: A confirmatory study

A number of diagnostic scales have been developed in recent years to assess Internet addiction. To better understand the structure, validity, and reliability of such assessment instruments, Young’s Internet Addiction Test (IAT) was evaluated using a confirmatory approach.Data collected through a survey of 410 Hong Kong university undergraduates was subjected to exploratory factor analysis and data from a hold-out sample was analyzed using confirmatory factor analysis in order to assess the psychometric properties and factor structure of the IAT scale. Three dimensions, namely, “Withdrawal and Social Problems”, “Time Management and Performance”, and “Reality Substitute” were extracted.These dimensions were then correlated with a number of criterion variables, including academic performance, online activities, gender, and Internet usage. The results show that academic performance was negatively correlated with the Internet addiction scores. The degree of Internet addiction was also found to vary across different types of online activity, with people engaged in cyberrelationships and online gambling having higher Internet addiction scores.     

Comments on: “Efficient robust constrained model predictive control with a time varying terminal constraint set” by Wan and Kothare

We present an algorithm that modifies the original formulation proposed in Wan and Kothare [Efficient robust constrained model predictive control with a time-varying terminal constraint set, Systems Control Lett. 48 (2003) 375–383]. The modified algorithm can be proved to be robustly stabilizing and preserves all the advantages of the original algorithm, thereby overcoming the limitation pointed out recently by Pluymers et al. [Min–max feedback MPC using a time-varying terminal constraint set and comments on “Efficient robust constrained model predictive control with a time-varying terminal constraint set”, Systems Control Lett. 54 (2005) 1143–1148].     

“Tryin to make a dolla outa fifteen cent”: Teaching composition with the Internet at an HBCU

Drawing upon nearly a decade of experience, I describe the challenges and advantages of teaching composition with the Internet at Howard University; I also explore the implications for other historically Black colleges and universities (HBCUs). First, I discuss the digital divide that has made it so difficult for many HBCU faculty members and students to access the Internet for composition courses. Next, I describe how students and I succeeded in harnessing the Internet not only to practice high-level writing skills but to “do cultural work”: to establish online “safe houses” for African American English, to collaborate with White North Americans and Black South Africans, and to publish Afrocentric material on the Web. In closing, I identify the pedagogical strategies that turned the Internet into a productive tool for the students in my writing courses.     

How Healthcare Professionals “Make Sense” of an Electronic Patient Record Adoption

This article examines how healthcare professionals experience an Electronic Patient Record (EPR) adoption process. Based on a case study from two surgical wards in Danish hospitals, we analyze the healthcare professionals' conceptions of the technology, how it relates to their professional roles, and aspects of the implementation process from a “sensemaking” perspective.     

Computational modeling issues and methods for the “regulatory problem” in engineering – Solutions to the structural dynamics and static frame problems

Many of the problems addressed through engineering analysis include a set of regulatory (or other) probabilistic requirements that must be demonstrated with some degree of confidence through the analysis. Problems cast in this environment can pose new challenges for computational analyses in both model validation and model-based prediction. The “regulatory problems” given for the “Sandia challenge problems exercise”, while relatively simple, provide an opportunity to demonstrate methods that address these challenges. This paper describes and illustrates methods that can be useful in analysis of the regulatory problem. Specifically, we discuss:

(1) an approach for quantifying variability and uncertainty separately to assess the regulatory requirements and provide a statement of confidence; and

(2) a general validation metric to focus the validation process on a specific range of the predictive distribution (the predictions near the regulatory threshold).

These methods are illustrated using the challenge problems. Solutions are provided for both the static frame and structural dynamics problems.

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.     

MCLP-based methods for improving “Bad” catching rate in credit cardholder behavior analysis

Cardholders’ behavior prediction is an important issue in credit card portfolio management. As a promising data mining approach, multiple criteria programming (MCLP) has been successfully applied to classify credit cardholders’ behavior into two groups. In order to better control credit risk for financial institutes, this paper proposes three methods based on MCLP to improve the “Bad” catching accuracy rate. One is called MCLP with unbalanced training set selection, the second is called fuzzy linear programming (FLP) method with moving boundary, and the third is called penalized multi criteria linear programming (PMCLP). The experimental examples demonstrate the promising performance of these methods.     

What is a “Good” Encoding of Guarded Choice?

The π-calculus with synchronous output and mixed-guarded choices is strictly more expressive than the π-calculus with asynchronous output and no choice. This result was recently proved by C. Palamidessi and, as a corollary, she showed that there is no fully compositional encoding from the former into the latter that preserves divergence-freedom and symmetries. This paper argues that there are nevertheless “good” encodings between these calculi. In detail, we present a series of encodings for languages with (1) input-guarded choice, (2) both input- and output-guarded choice, and (3) mixed-guarded choice, and investigate them with respect to compositionality and divergence-freedom. The first and second encoding satisfy all of the above criteria, but various “good” candidates for the third encoding—inspired by an existing distributed implementation—invalidate one or the other criterion. While essentially confirming Palamidessi's result, our study suggests that the combination of strong compositionality and divergence-freedom is too strong for more practical purposes.     

‘Because it’s boring, irrelevant and I don’t like computers’: Why high school girls avoid professionally-oriented ICT subjects

The current paper details results from the Girls and ICT survey phase of a three year study investigating factors associated with low participation rates by females in education pathways leading to professional level information and communications technology (ICT) professions. The study is funded through the Australian Research Council’s (ARC) Linkage Grants Scheme. It involves a research partnership between Education Queensland (EQ), industry partner Technology One and academic researchers at (affiliation removed for review purposes). Respondents to the survey were 1453 senior high school girls. Comparisons were drawn between Takers (n = 131) and Non Takers (n = 1322) of advanced level computing subjects. Significant differences between the groups were found on four questions: “The subjects are interesting”; “I am very interested in computers”; “The subject will be helpful to me in my chosen career path after school”; and “It suited my timetable”. The research has demonstrated that senior high school girls tend to perceive advanced computing subjects as boring and they express a strong aversion to computers.