When does abstraction help?

Abstraction is a leading technique for coping with large state spaces. Abstraction over-approximates the transitions of the original system or the automaton that models it and may introduce nondeterminism. In applications where determinism is essential, we say that an abstraction function is helpful if, after determining and minimizing the abstract automaton, we end up with fewer states than the original automaton. We show that abstraction functions are not always helpful; in fact, they may introduce an exponential blow-up. We study the problem of deciding whether a given abstraction function is helpful for a given deterministic automaton and show that it is PSPACE-complete.     

When does a workflow complete?

Workflow Management Systems (WFMS) coordinate execution of logically related multiple tasks in an organization. Each workflow that is executed on such a system is an instance of some workflow schema. A workflow schema is defined using a set of tasks that are coordinated using dependencies. Workflows generated from the same schema may differ with respect to the tasks executed. An important issue that must be addressed while designing a workflow is to decide what tasks are needed for the workflow to complete — we refer to this set of tasks as the completion set. Since different tasks are executed in different workflow instances, a workflow schema may be associated with multiple completion sets. Incorrect specification of completion sets may prohibit some workflow from completing. This, in turn, will cause the workflow to hold on to the resources and raise availability problems. Manually generating these sets for large workflow schemas can be an error-prone and tedious process.Our goal is to automate this process. We investigate the factors that affect the completion of a workflow. Specifically, we study the impact of control-flow dependencies on completion sets and show how this knowledge can be used for automatically generating these sets. We provide an algorithm that can be used by application developers to generate the completion sets associated with a workflow schema. Generating all possible completion sets for a large workflow is computationally intensive. Towards this end, we show how to approximately estimate the number of completion sets. If this number exceeds some threshold specified by the user, then we do not generate all completion sets.     

Robotic assistants in therapy and education of children with autism: can a small humanoid robot help encourage social interaction skills?

This article presents a longitudinal study with four children with autism, who were exposed to a humanoid robot over a period of several months. The longitudinal approach allowed the children time to explore the space of robot–human, as well as human–human interaction. Based on the video material documenting the interactions, a quantitative and qualitative analysis was conducted. The quantitative analysis showed an increase in duration of pre-defined behaviours towards the later trials. A qualitative analysis of the video data, observing the childrens activities in their interactional context, revealed further aspects of social interaction skills (imitation, turn-taking and role-switch) and communicative competence that the children showed. The results clearly demonstrate the need for, and benefits of, long-term studies in order to reveal the full potential of robots in the therapy and education of children with autism.

When does personalization work on social media? a posteriori segmentation of consumers

The aim of this research is to find a segment of consumers of fashion products based on their personal visions of personalization of shoppable ads on mobile social media. To meet this objective, three operational objectives are defined. First, a theoretical model is evaluated based on the stimulus-organism-response framework (S–O–R). This examines, with a PLS-SEM approach, how the stimulation of personalization will affect consumers' internal cognitive state (perceived usefulness) and consequently generates a behavioral response (intention to buy). Second, we look for fashion consumer segments based on their perception of personalization through prediction-oriented segmentation (PLS-POS). Third, the segments are explained based on three constructs that were considered important in fashion consumption through mobile social networks: purchase intention, concern for privacy, and perception of trend. The inclusion of personalization and the perception of usefulness of advertisements can greatly help the intention to purchase clothing to be understood. The application of a posterior segmentation helps to better understand the different types of users exposed to shoppable ads on mobile social networks and their relationship with the purchase intention, concern for privacy and trend. While the measures and scales were tested in a context of mobile clothing trade, the methodology can be applied to other types of products or services.

     

Bursting without slow kinetics: a role for a small world?

Bursting, a dynamical phenomenon whereby episodes of neural action potentials are punctuated by periodic episodes of inactivity, is ubiquitous in neural systems. Examples include components of the respiratory rhythm generating circuitry in the brain stem, spontaneous activity in the neonatal rat spinal cord, and developing neural networks in the retina of the immature ferret. Bursting can also manifest itself in single neurons. Bursting dynamics require one or more kinetic processes slower than the timescale of the action potentials. Such processes usually manifest themselves in intrinsic ion channel properties, such as slow voltage-dependent gating or calcium-dependent processes, or synaptic mechanisms, such as synaptic depression. In this note, we show rhythmic bursting in a simulated neural network where no such slow processes exist at the cellular or synaptic level. Rather, the existence of rhythmic bursting is critically dependent on the connectivity of the network and manifests itself only when connectivity is characterized as small world. The slow process underlying the timescale of bursting manifests itself as a progressive synchronization of the network within each burst.     

Workplace assessment: a tool for occupational health and safety management in small firms?

This paper discusses the capability of small firms to comply with legislative demands on risk assessment. The results of a national survey show that only a minor fraction of small firms comply. Two case studies demonstrate that small firms are able to meet the demands. An analysis of these cases leads to some hypotheses on the preconditions for compliance. Many firms need a person to mediate legislative demands. The demands for qualifications to fulfil this role are discussed. The conclusion is that it is possible to qualify persons as mediators. Therefore, to stimulate ergonomic activities in small firms resources for such mediators are required. The occupational health services are able to train a staff to undertake the task.     

How does a backrest work?

After discussing the distribution of forces in the stable upright posture and illustrating the importance of the lumbar lordosis for minimising muscular effort in this position, the loadings on the spine and muscles of the back are outlined during upright sitting. It is shown that the backrest locates the lumbar spine so that the CG of the superincumbent body parts can be positioned above the vertebrae, permitting the gravity load to be transmitted to the seat without the counteracting torques which muscles would have to provide if this position was not adopted. The forces arising from other sitting positions are then discussed, and some conclusions drawn for seat design.     

Can feature information interaction help for information fusion in multimedia problems?

This article presents the information-theoretic based feature information interaction, a measure that can describe complex feature dependencies in multivariate settings. According to the theoretical development, feature interactions are more accurate than current, bivariate dependence measures due to their stable and unambiguous definition. In experiments with artificial and real data we compare first the empirical dependency estimates of correlation, mutual information and 3-way feature interaction. Then, we present feature selection and classification experiments that show superior performance of interactions over bivariate dependence measures for the artificial data, for real world data this goal is not achieved yet.

When does QP yield the exact solution to constrained NMPC?

It is well known that the optimal control sequence for a linear system with a quadratic cost and linear inequality constraints over a finite optimisation horizon can be computed by means of a quadratic programme (QP). The aim of this article is to investigate when the optimal control sequence for a non-linear single-input single-output system also can be computed via QP. Our main contribution is to show that the optimal control sequence for non-linear systems, with a quadratic cost and linear inequality constraints can be computed in exact form via QP provided the optimisation horizon is no larger than a critical quantity that we name the ‘input–output linear horizon’. The results do not require any linearisation technique and are applicable to general non-linear systems, provided their input–output linear horizon is larger than their relative degree.     

What a machine should know about philosophical problems?

This paper maps out some of the few remaining challenges to artificial intelligence from the point of view of philosophy and fuzzy logic. Certain key ideas of Lotfi Zadeh are used as a point of reference. Human reasoning is a complex procedure which is able to handle such problems as the counterfactual truth and the supervenience relation, which are difficult to explain in terms of the classical logical theory. To achieve this, one needs to understand them in a more natural manner than the standard positivistic logic is able to do. Next some examples taken from ethical theory are discussed, such as the fact/value-distinction and supererogation. These provide typically hard cases to the positivist methodology, as its representatives have always admitted. The results are applied to the philosophical problems of robotics, especially to the notion of a Cyborg on the information web. A Cyborg on the Web should be able to combine human-like reasoning with unlimited information processing.     

How does Internet information seeking help academic performance? – The moderating and mediating roles of academic self-efficacy

Although researchers tend to agree that Internet is a good source for learning and research, little empirical data has substantiated this claim by specifically linking time and effort spent on the Internet for school related information seeking to academic performances. This research investigates the relationship between vocational high school students’ information seeking activities on the Internet, academic self-efficacy, and academic performance. We propose that academic self-efficacy both mediates and moderates the relationship between Internet information seeking and academic performance. Using survey data from 295 vocational high school students in Taiwan, we found that the positive effect of Internet information seeking to students’ academic performance is mediated through academic self-efficacy. Academic self-efficacy, at the same time, moderates the relationship between Internet information seeking to academic performance such that students’ with low academic self-efficacy benefit more from Internet information seeking in regard to their academic performance. We discussed the implications of our findings and provided future directions for research.     

Incorporating domain knowledge and spatial relationships into land cover classifications: a rule‐based approach

For some tropical regions, remote sensing of land cover yields unacceptable results, particularly as the number of land cover classes increases. This research explores the utility of incorporating domain knowledge and multiple algorithms into land cover classifications via a rule‐based algorithm for a series of satellite images. The proposed technique integrates the fundamental, knowledge‐based interpretation elements of remote sensing without sacrificing the ease and consistency of automated, algorithm‐based processing. Compared with results from a traditional maximum likelihood algorithm, classification accuracy was improved substantially for each of the six land cover classes and all three years in the image series. Use of domain knowledge proved effective in accurately classifying problematic tropical land covers, such as tropical deciduous forest and seasonal wetlands. Results also suggest that ancillary data may be most useful in the classification of historic images, where the greatest improvement was observed relative to results from maximum likelihood. The cost of incorporating contextual knowledge and extensive spatial data sets may be justified, since results from the proposed technique suggest a considerable improvement in accuracy may be achieved.     

Algorithms or advocacy: does the legal profession have a future in a digital world?

Much of the focus on the impact of new technology on employment has been on work which is regarded as repetitive and requiring minimal skills. For the most part it seems that professional occupations have been assumed to be relatively immune to the effects of ‘digital disruption’. However, there are now suggestions that this is altering as new software programs have been developed that can undertake at least some of the functions of various professions, including the legal profession. This article seeks to add to the evolving conversation of how new technologies might transform the legal profession as we know it. Beyond this, it also seeks to ask how the content of the law and legal education might also be affected by ‘digital disruption’, and explore the opportunities such unravelling of the legal profession might present.     

“It is what one does”: why people participate and help others in electronic communities of practice

Advances in information and communication technologies have fundamentally heightened organizational interest in knowledge as a critical strategic resource. However, organizations are finding that members are often reluctant to exchange knowledge with others in the organization. This paper examines why. We review current knowledge management practices and find that organizations are treating knowledge as a private good, owned either by the organization or by organization members. We propose that knowledge can also be considered a public good, owned and maintained by a community. When knowledge is considered a public good, knowledge exchange is motivated by moral obligation and community interest rather than by narrow self-interest. We provide support for the public good perspective by providing results from a survey examining why people participate and share knowledge in three electronic communities of practice. The results indicate that people participate primarily out of community interest, generalized reciprocity and pro-social behavior.     

On the applicability of capability models for small software organizations: does the use of standard processes lead to a better achievement of business goals?

The ISO/IEC 15504 standard implies that the use of its level-based capability model for software process development leads to a better business performance. At capability level 3, this would mean that there is not only a positive correlation but also a causal relation from the use of standard processes to better achievement of business goals. In this paper, we make this claim explicit and challenge it with a counterargument in the context of small software organizations. We argue that in most part, the way the software is designed is what determines the business success in software development, and when application domains are complex socio-technical systems, relying on a standard process instead of human expertise not only fails to answer the promise of process stability but also presents business risks related to poor design, a loss of diversity, and reduced adaptability. With reasons to believe that the standard’s claim is weak in this context, we come up with alternative explanations for why some small software organizations nevertheless use standard processes. Through these hypotheses, we argue that the reasons are not necessarily process-related. In closing, we suggest further studies on how the standard’s notion of process capability and business goals relate to each other when the application domain is not just complicated but complex.     

Graphing small data sets: Should we bother?

While display designers tend to agree that the communication of large amounts of quantitative information calls for the use of graphs, there is less consensus about whether graphs should be used for small, summarized data sets. In the present study, three groups of 16 subjects viewed 11 sets of time series data presented as tables, bar charts, or line graphs. Data sets varied in size (4, 7, or 13 values) and complexity (number and type of departures from linearity). Subjects provided written interpretations of each of the data sets, and these interpretations were scored for (1) overall number of propositions pertaining to the data set as a whole (global content), (2) number of propositions describing relations within a subset of the data (local content), and (3) number of references to specific data values (numeric content). For the larger (7- and 13-point) data sets, interpretations based on bar charts included the greatest overall global content, but line graph interpretations proved to be most sensitive to the actual information content (complexity) of the data sets. The greater sensitivity of the line graphs was still obtained with four-point data sets; however, this advantage was greater for men than for women. For data sets of all sizes, but especially for the smallest sets, gender differences in interpretation content were obtained. These differences are discussed within the context of more general individual differences presumed to exist in graphreading strategies.