User interface design affects security: patterns in click-based graphical passwords

Design of the user interface for authentication systems influences users and may encourage either secure or insecure behaviour. Using data from four different but closely related click-based graphical password studies, we show that user-selected passwords vary considerably in their predictability. Our post-hoc analysis looks at click-point patterns within passwords and shows that PassPoints passwords follow distinct patterns. Our analysis shows that many patterns appear across a range of images, thus motivating attacks which are independent of specific background images. Conversely, Cued Click-Points (CCP) and Persuasive Cued Click-Points (PCCP) passwords are nearly indistinguishable from those of a randomly generated simulated dataset. These results provide insight on modeling effective password spaces and on how user interface characteristics lead to more (or less) security resulting from user behaviour.     

Layout design in dynamic environments: analytical issues

The paper discusses the layout problem for a productive environment affected by variability of demand (dynamic environment). A conceptual framework of the layout flexibility is discussed, according to the concept of layout robustness. An analytical approach extends the technique adopted for the optimal layout determination from the static to the dynamic context. For an assigned layout problem, an example shows how the analytical approach may be applied to the calculation of the probability distribution of the cost function. From this basis, a measure of the layout robustness is proposed and commented on, in order to give useful advice to those in charge of layout planning and control and to highlight the potential use of the theoretical issues discussed.     

An example is worth a thousand words: Creating graphical modelling environments by example

Software and Systems Modeling - Domain-specific languages (DSLs) are heavily used in model-driven and end-user development approaches. Compared to general-purpose languages, DSLs present numerous...     

Introducing prototype interactive evolutionary systems for ill-defined,multi-objective design environments

The paper introduces experimental prototype software that represents a number of modules within a proposed interactive evolutionary design system (IEDS). The purpose and structure of each module is briefly described and graphical user interfaces are introduced to illustrate the manner in which the prototypes may be utilised both as stand-alone modules and as linked co-operative elements. Results are presented and discussed in the light of perceived practical potential and mode of utilisation. The system under development specifically aims at the support of decision-making processes during the conceptual stages of multi-disciplinary design where the main characteristics relate to uncertainty, ill-definition and multiple objectives. Although co-evolutionary processes provide a search and exploration core, other deterministic and adaptive processes are introduced to support the requirements of the user. These include linguistic preferences, multi-agent approaches and data extraction techniques.     

AEthereal network on chip: concepts, architectures, and implementations

The continuous advances in semiconductor technology enable the integration of increasing numbers of IP blocks in a single SoC. Interconnect infrastructures, such as buses, switches, and networks on chips (NoCs), combine the IPs into a working SoC. Moreover, the industry expects platform-based SoC design to evolve to communication-centric design, with NoCs as a central enabling technology. In this article, we introduce the AEthereal NoC. The tenet of the AEthereal NoC is that guaranteed services (GSs) - such as uncorrupted, lossless, ordered data delivery; guaranteed throughput; and bounded latency - are essential for the efficient construction of robust SoCs. To exploit the NoC capacity unused by the GS traffic, we provide best-effort services.     

Adaptive dynamic collision checking for single and multiple articulated robots in complex environments

Static collision checking amounts to testing a given configuration of objects for overlaps. In contrast, the goal of dynamic checking is to determine whether all configurations along a continuous path are collision-free. While there exist effective methods for static collision detection, dynamic checking still lacks methods that are both reliable and efficient. A common approach is to sample paths at some fixed, prespecified resolution and statically test each sampled configuration. But this approach is not guaranteed to detect collision whenever one occurs, and trying to increase its reliability by refining the sampling resolution along the entire path results in slow checking. This paper introduces a new method for testing path segments in c-space or collections of such segments, that is both reliable and efficient. This method locally adjusts the sampling resolution by comparing lower bounds on distances between objects in relative motion with upper bounds on lengths of curves traced by points of these moving objects. Several additional techniques and heuristics increase the checker's efficiency in scenarios with many moving objects (e.g., articulated arms and/or multiple robots) and high geometric complexity. The new method is general, but particularly well suited for use in probabilistic roadmap (PRM) planners, where it is critical to determine as quickly as possible whether given path segments collide, or not. Extensive tests, in particular on randomly generated path segments and on multisegment paths produced by PRM planners, show that the new method compares favorably with a fixed-resolution approach at "suitable" resolution, with the enormous advantage that it never fails to detect collision.     

Collaborative distributed environments for learning design tasks by means of modelling and simulation

The Simulation discipline has to face new challenges such as the incorporation of Collaborative Technologies for professional use as well as for teaching purposes. This integration permits the creation of new kinds of support for collaborative learning processes. In this paper, we explore the potential of this synergy with DomoSim-TPC, a synchronous distributed collaborative environment for the teaching and learning of Domotics. The system supports an active, simulation-based and problem-based approach for learning house automation design. Using this learning environment, teachers propose and organize problem solving activities and the students carry out, in a collaborative way, the construction of artefacts (designs) using modelling and simulation tools.     

Optimal self-explanation prompt design in dynamic multi-representational learning environments

Self-explanation prompts are considered to be an important form of scaffolding in the comprehension of complex multimedia materials. However, there is little theoretical understanding to date of self-explaining prompt formats tailored to different expertise levels of learners to help them fully exploit the advantages of dynamic multi-representational materials. To address this issue, this study designed two types of self-explaining prompts: the reasoning-based prompts asked the learners to reason the action run of the animation; the predicting-based prompts asked the learners to predict the upcoming action of the animation, and then asked for reasoning if they made a wrong prediction. Furthermore, multiple indicators including learning outcome, cognitive load demand, learning time, and learning efficiency were used to interpret the prompts’ effects on different expertise levels of learners. A total of 244 undergraduate students were randomly assigned to one of the three conditions: a control and two different self-explaining prompt conditions. The results indicate that the learning effects of self-explaining prompts depend on levels of learner expertise. Based on the results, this study makes recommendations for adaptive self-explaining prompt design.     

Underwater glider design based on dynamic model analysis and prototype development

Underwater gliders are efficient mobile sensor platforms that can be deployed for months at a time, traveling thousands of kilometers. Here, we describe our development of a coastal 200 m deep underwater glider, which can serve as an ocean observatory platform operating in the East China Sea. Our glider is developed based on dynamic model analysis: steady flight equilibrium analysis gives the varied range of moving mass location for pitch control and the varied vehicle volume for buoyancy control; a stability analysis is made to discuss the relationship between the stability of glider motion and the location of glider wings and rudder by root locus investigation of glider longitudinal- and lateral-directional dynamics, respectively. There is a tradeoff between glider motion stability and control authority according to the specific glider mission requirements. The theoretical analysis provides guidelines for vehicle design, based on which we present the development progress of the Zhejiang University (ZJU) glider. The mechanical, electrical, and software design of the glider is discussed in detail. The performances of glider key functional modules are validated by pressure tests individually; preliminary pool trials of the ZJU glider are also introduced, indicating that our glider functions well in water and can serve as a sensor platform for ocean sampling.     

AIR-MODELLING: A tool for gesture-based solid modelling in context during early design stages in AR environments

Augmented reality (AR) technologies are just being used as interface in CAD tools allowing the user to perceive 3D models over a real environment. The influence of the use of AR in the conceptualization of products whose configuration, shape and dimensions depend mainly on the context remains unexplored. We aimed to prove that modelling in AR environments allows to use the context in real-time as an information input for making the iterative design process more efficient. In order to prove that, we developed a tool called AIR-MODELLING in which the designer is able to create virtual conceptual products by hand gestures meanwhile he/she is interacting directly with the real scenario. We conducted a test for comparing designers’ performance using AIR-MODELLING and a traditional CAD system. We obtained an average reduction of 44% on the modeling time in 76% of the cases. We found that modelling in AR environments using the hands as interface allows the designer to quickly and efficiently conceptualize potential solutions using the spatial restrictions of the context as an information input in real-time. Additionally, modelling in a natural scale, directly over the real scene, prevents the designer from drawing his/her attention on dimensional details and allows him/her to focus on the product itself and its relation with the environment.     

User resistance determinants and the psychological contract in enterprise system implementations

User resistance is an important issue in the implementation of enterprise systems (ES). However, despite a large body of user acceptance literature, there is far less literature addressing user resistance. This study seeks to better understand the development of user resistance. Information is obtained and triangulated in this study from a focus group and semi-structured user interviews from three organizations. Through the lens of the psychological contract employees have with their organization, user resistance is investigated. Twelve determinants were found that upset the psychological contract and affect the level of user resistance. These determinants have been classified into four key categories which expand on previous literature: individual, system, organizational, and process issues. The relationships among these concepts and both the theoretical and practical contributions of this study are discussed.     

Developing alternative design concepts in VR environments using volumetric self-organizing feature maps

The conceptual design process has not benefited from conventional computer-aided design (CAD) technology to the same degree as embodiment design because the creative activities associated with developing and communicating alternative solutions, with minimal detail, is far less formulaic in its implementation. Any CAD system that seeks to support and enhance conceptual design must, therefore, enable natural and haptic modes of human–computer interaction. A computational framework for economically representing deformable solid objects for conceptual design is described in this paper. The physics-based deformation model consists of a set of point masses, connected by a series of springs and dampers, which undergo movement through the influence of external and internal forces. The location of each mass point corresponds to a node on a 3D mesh defined by a volumetric self-organizing feature map (VSOFM). A reference mesh is first created by fitting the exterior nodes of the VSOFM to sampled data from the surface of a primitive shape, such as a cube, and then redistributing the interior nodes to reflect evenly spaced hexahedral elements. Material properties are introduced to the mesh by assigning a mass value to individual nodes and spring coefficients to the nodal connections. Several illustrations involving the redesign of an ergonomic writing pen is used to demonstrate how the proposed virtual reality-based modeling system will permit the industrial designer to interactively change the shape and function of a design concept.     

Use of dynamic modelling and plant historian data for improved control design

Problems associated with process control equipment, such as valves, can be very subtle and difficult to detect. However, the impact that these problems can have on the performance of a process control system can be significant. This paper explores the use of dynamic, mechanistic modelling as a tool for detecting problems associated with process control equipment and as a technique for validating that corrective action which will solve these problems before such action is applied to the plant. The paper describes a case-study application at an INEOS ChlorVinyls site in Runcorn. In this case study, a dynamic model was able to identify the cause of a serious plant problem and determine the necessary re-configuration of the plant control systems, such that plant operations were improved.     

Drafting ER and OO schemas in prototype environments

The system Q_ueer is a prototype of an information system design tool which directly supports an extended Entity-Relationship model on its front-end and uses a semantically well-founded query and manipulation language based on an Entity-Relationship calculus. The system basically consists of a set of compilers written in P_rolog which translate data specifications, schema definitions, queries, integrity constraints and data-manipulation statements into P_rolog programs. All features mentioned are implemented in form and extent as described here.     

Reconfigurable natural interaction in smart environments: approach and prototype implementation

The vision of sensor-driven applications that adapt to the environment hold great promise, but it is difficult to turn these applications into reality because device and space heterogeneity is an obstacle to interoperability and mutual understanding of the smart devices and spaces involved. Smart Spaces provide shared knowledge about physical domains and they inherently enable cooperative and adaptable applications by keeping track of the semantic relations between objects in the environment. In this paper, the interplay between sensor-driven objects and Smart Spaces is investigated and a device with a tangible interface demonstrates the potential of the ${\sl smart{\text -}space{\text -}based}$ and ${\sl sensor{\text -}driven}$ computing paradigm. The proposed device is named REGALS (Reconfigurable Gesture based Actuator and Low Range Smartifier). We show how, starting from an interaction model proposed by Niezen, REGALS can reconfigure itself to support different functions like Smart Space creation (also called ${\sl environment\,smartification}$ ), interaction with heterogeneous devices and handling of semantic connections between gestures, actions, devices, and objects. This reconfiguration ability is based on the context received from the Smart Space. The paper also shows how tagged objects and natural gestures are recognized to improve the user experience reporting a use case and the performance evaluation of REGALS’ gesture classifier.     

XSDyM: An XML graphical conceptual model for static and dynamic constraints

Data modelling is not only important to visualise the structural schema of data, but also to show the intended integrity constraints. In this paper, we propose a modelling approach called XML Static Dynamic Modelling (XSDyM). While a text-based schema definition is often the most common method used to describe XML, graphical modelling is more accepted as it is capable of visualising the schema definition more effectively for the reader. Conveying the dynamic constraints on XML graphical model requires a special treatment as the constraints basically comprehend the state transitions. It is important for an XML modelling to keep the basis as precise as possible to satisfy the nature of XML and at the same time be able to represent the constraints in an effective way. Using the XML tree-based modelling as the basis of the work, we proposed our own approach to convey the state transitions of the constraints, where it is inspired from the well-known state diagram and adopt some useful features of ORM modelling. We evaluate the correctness of our proposed modelling using a model which involves the checking of model transformations between the modelling and the equivalent XML schema languages.     

Protein folding: a prototype for control of complex systems

One of the basic problems of the theory of control in complex systems involves determining the circumstances under which a set of control parameters can effectively manipulate a much larger number of degrees of freedom in the controlled system. Such a control capability obviously requires the presence of additional constraints relating the quantities to be controlled. We explore this general question in the context of a specific situation; namely, in terms of an algorithm recently proposed to compute the three-dimensional structures of folded polypeptides from their amino acid sequences. In this algorithm, a small number of average geometric properties (the control parameters) are utilized to determine a much larger set of inter-residue distances in the folded structure. We derive the specific condition which assures that the algorithm converges pointwise to the correct structure, which in this case turns out to involve relating rates of change of coordinates to increments in the distances consistent with a particular set of values for the control parameters. Some further implications of this kind of result are briefly discussed.     

RTTES: Real-time search in dynamic environments

In this paper we propose a real-time search algorithm called Real-Time Target Evaluation Search (RTTES) for the problem of searching a route in grid worlds from a starting point to a static or dynamic target point in real-time. The algorithm makes use of a new effective heuristic method which utilizes environmental information to successfully find solution paths to the target in dynamic and partially observable environments. The method requires analysis of nearby obstacles to determine closed directions and estimate the goal relevance of open directions in order to identify the most beneficial move. We compared RTTES with other competing real-time search algorithms and observed a significant improvement on solution quality.