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.     

Where does model-driven engineering help? Experiences from three industrial cases

There have been few experience reports from industry on how Model-Driven Engineering (MDE) is applied and what the benefits are. This paper summarizes the experiences of three large industrial participants in a European research project with the objective of developing techniques and tools for applying MDE on the development of large and complex software systems. The participants had varying degrees of previous experience with MDE. They found MDE to be particularly useful for providing abstractions of complex systems at multiple levels or from different viewpoints, for the development of domain-specific models that facilitate communication with non-technical experts, for the purposes of simulation and testing, and for the consumption of models for analysis, such as performance-related decision support and system design improvements. From the industrial perspective, a methodology is considered to be useful and cost-efficient if it is possible to reuse solutions in multiple projects or products. However, developing reusable solutions required extra effort and sometimes had a negative impact on the performance of tools. While the companies identified several benefits of MDE, merging different tools with one another in a seamless development environment required several transformations, which increased the required implementation effort and complexity. Additionally, user-friendliness of tools and the provision of features for managing models of complex systems were identified as crucial for a wider industrial adoption of MDE.     

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.     

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.

     

When do extra majority gates help? Polylog (N) majority gates are equivalent to one

Suppose that a Boolean functionf is computed by a constant depth circuit with 2 ^m AND-, OR-, and NOT-gates—andm majority-gates. We prove thatf is computed by a constant depth circuit with AND-, OR-, and NOT-gates—and a single majority-gate, which is at the root.One consequence is that if a Boolean functionf is computed by an AC⁰ circuit plus polylog majority-gates, thenf is computed by a probabilistic perceptron having polylog order. Another consequence is that iff agrees with the parity function on three-fourths of all inputs, thenf cannot be computed by a constant depth circuit with AND-, OR-, and NOT-gates, and majority-gates.     

When does web-based personalization really work? The distinction between actual personalization and perceived personalization

A number of prior studies have suggested that personalization is more efficacious than non-personalization. However, the existing literature is somewhat ambiguous on whether the test of personalization effects should be based on a message sender's actual personalization process or a message recipient's perception of the message. It is argued in this article that an actual personalization process does not automatically yield more favorable effects because people's perceptions of personalized messages tend to be biased. Through three experiments, it is demonstrated that testing personalization effects based on a message sender's actual personalization process can be problematic and produce misleading results. Specifically, a personalized message can be perceived as non-personalized and a non-personalized message can be perceived as personalized. The key finding is that perceived personalization, instead of actual personalization, is the underlying psychological mechanism of message effectiveness. A message will show superior effects when it is perceived to be personalized by a message recipient, regardless of whether it is actually personalized or not.     

When is play productive?

Play at work is not a contradiction in terms. Rather, distinctions between work and play are becoming less clear, as more jobs involve expertise and microcomputers. This paper starts by describing play, its motives, and its consequences. Then the paper focuses on computer-based activities and suggests guidelines for activities and situations where play can enhance productivity. These guidelines should interest both software designers and those who choose software. The guidelines also generalize to work without computers.     

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.     

Does syntax highlighting help programming novices?

Program comprehension is an important skill for programmers – extending and debugging existing source code is part of the daily routine. Syntax highlighting is one of the most common tools used to support developers in understanding algorithms. However, most research in this area originates from a time when programmers used a completely different tool chain. We examined the influence of syntax highlighting on novices’ ability to comprehend source code. Additional analyses cover the influence of task type and programming experience on the code comprehension ability itself and its relation to syntax highlighting. We conducted a controlled experiment with 390 undergraduate students in an introductory Java programming course. We measured the correctness with which they solved small coding tasks. Each test subject received some tasks with syntax highlighting and some without. The data provided no evidence that syntax highlighting improves novices’ ability to comprehend source code. There are very few similar experiments and it is unclear as of yet which factors impact the effectiveness of syntax highlighting. One major limitation may be the types of tasks chosen for this experiment. The results suggest that syntax highlighting squanders a feedback channel from the IDE to the programmer that can be used more effectively.     

Idea generation and open innovation in SMEs: When does market‐based collaboration pay off most?

Small‐ and medium‐sized enterprises (SMEs) largely depend on proficient idea generation activities to improve their front‐end innovation performance, yet the liabilities of newness and smallness often hamper SMEs' ability to benefit from systematic idea generation. To compensate for these liabilities, many SMEs adopt an open innovation approach by collaborating with market‐based partners such as customers and suppliers. This study investigates the relationship between SMEs' systematic idea generation and front‐end performance and investigates the moderating role of market‐based partnership for SMEs. Drawing on a survey of 146 Swedish manufacturing SMEs, this study provides two key contributions. First, the systematic idea generation and front‐end performance relationship in SMEs is non‐linear. Accordingly, higher levels of front‐end performance are achieved when idea generation activities are highly systematic. Second, the returns from higher levels of systematic idea generation are positively moderated by market‐based partnerships. Thus, external cooperation with customers and suppliers pays off most toward front‐end performance when SMEs have highly systematic idea generation processes. These results indicate a contingency perspective on the role of external partnerships. They also have implications for research into the front‐end of innovation and open innovation in the context of SMEs.     

When does an easy task become hard? A systematic review of human task-evoked pupillary dynamics versus cognitive efforts

The amount of working memory recourses available (or required) to process a cognitive task (easy or hard) represents human cognitive effort. Working memory resources (visual or auditory) and cognitive efforts are interconnected with visual or auditory pathways. In this review, various facets of pupillary dynamics literature are compared in order to determine an optimal method of cognitive effort assessment. Some key categorical areas of interest are identified including the presented stimulus, observed response, comparisons and different methods of analysis. In details review, a set of predetermined evaluation criteria were used and a decision matrix is developed to outline the best practice in papillary dynamics. Based on the summery table in the form of the decision matrix, a quantitative model with artificial neural network (ANN) is selected for a best practice of cognitive effort estimation. The mental multiplication task is found an effective stimulus (cognitive task) to evoke the pupillary response for various level of task difficulty. In most cases, aural and visual are considered as two presentation modes, two sensory inputs, and two mental resources and greatly imparts in cognitive workload. Through this review, it is also explored that, linking together by transfer and error functions, a combination of an ANN and a multinomial processing tree can used in cognitive effort analysis. This research direction can further explored to estimate the relationship between cognitive task and cognitive effort, to facilitate in technology development for neurological disorders, such as narcolepsy, on the neural pathways involved in cognitive processing.

     

485 1170 — Can I help you?

The ergonomics aspects of the design of a domestic telephone are outlined as a case study. The main usage points investigated were: handset relationship to ear and mouth together with adequate finger clearance at the cheek; general comfort when picking up and holding the handset; replacing the handset correctly in order to operate the hook-switch; establishing an acceptable compromise for dial and keypad angle at 15 degrees ; and devising a wall mounted unit.