Context for goal-level product line derivation

Product line engineering aims at developing a family of products and facilitating the derivation of product variants from it. Context can be a main factor in determining what products to derive. Yet, there is gap in incorporating context with variability models. We advocate that, in the first place, variability originates from human intentions and choices even before software systems are constructed, and context influences variability at this intentional level before the functional one. Thus, we propose to analyze variability at an early phase of analysis adopting the intentional ontology of goal models, and studying how context can influence such variability. Below we present a classification of variation points on goal models, analyze their relation with context, and show the process of constructing and maintaining the models. Our approach is illustrated with an example of a smarthome for people with dementia problems. 1

Towards a Simpler Selection Process for Maintenance Strategies

Recent research at four large manufacturing sites in the North East of England showed that maintenance organisations were failing because they were locked in a cycle of quick fix and mend despite deploying extensive planned maintenance policies. Consequently they were unable to plan and formulate strategies because they did not have the time. Simple and quick tools were needed to select the best maintenance approach for the machines and the plant. Two possible selection tools were developed. Firstly a truth table was produced based on the key characteristics of each maintenance approach and these mapped against simplified failure mode combinations. This offered a quick and easy selection method for machines, based on failure mode patterns. Secondly, the macro level was addressed using a conceptual model employing a 2x2 matrix. This consisted of two axes, the level of machine failures and the level of improvement activity. The resulting framework was used to predict how maintenance organisations would progress from a state of reactive maintenance towards world class. Then informed by the truth table it was possible to select an appropriate maintenance approach which was most suitable for each stage. It is suggested that these two methods offer simple and quick approaches to guide vital maintenance decision making at plants in difficulty. This of course does not preclude the need to develop maintenance strategies but rather facilitates this process by freeing up time and resources

Chicano/Mexican Culture as a Rational Instrument in the Human Sciences

The use of culture as an analytical category by social scientists presents an opportunity to examine how professional discursive formations are used to make empirical assertions. The social fact of culture is neither uniform nor unitary. Traditionally, culture has been thought of as a product of disciplinary research, not necessarily a variable for empirical study. When culture is used as a tool or instrument of scientific methodology, it loses its fluid nature as a disciplinary discourse. In this essay, I examine the specific discussion of the epidemiologic health paradox that states that the Chicano/Mexican immigrant culture serves as a protective factor against many maladies that afflict other U.S. populations. Since the 1970s, this discussion of culture as a protective factor provides an interesting exposition of the uses of culture by empirical scholars

Delusion, Proper Function, and Justification

Among psychiatric conditions, delusions have received significant attention in the philosophical literature. This is partly due to the fact that many delusions are bizarre, and their contents interesting in and of themselves. But the disproportionate attention is also due to the notion that by studying what happens when perception, cognition, and belief go wrong, we can better understand what happens when these go right. In this paper, I attend to delusions for the second reason—by evaluating the epistemology of delusions, we can better understand the epistemology of ordinary belief. More specifically, given recent advancements in our understanding of how delusions are formed, the epistemology of delusions motivates a proper functionalist account of the justification of belief. Proper functionalist accounts of the justification of belief hold that whether a belief is justified is partly determined by whether the system that produces the belief is functioning properly. Whatever pathology is responsible for delusion formation, restoring it to its proper function resolves the epistemic condition, an effect which motivates proper functionalism

Analysis of navigation performance for the Earth Observing System (EOS) using the TDRSS Onboard Navigation System (TONS)

Use of the Tracking and Data Relay Satellite System (TDRSS) Onboard Navigation System (TONS) was proposed as an alternative to the Global Positioning System (GPS) for supporting the Earth Observing System (EOS) mission. The results are presented of EOS navigation performance evaluation with respect to TONS based orbit, time, and frequency determination (OD/TD/FD). Two TONS modes are considered: one uses scheduled TDRSS forward link service to derive one way Doppler tracking data for OD/FD support (TONS-I); the other uses an unscheduled navigation beacon service (proposed for Advanced TDRSS) to obtain pseudorange and Doppler data for OD/TD/FD support (TONS-II). Key objectives of the analysis were to evaluate nominal performance and potential sensitivities, such as suboptimal tracking geometry, tracking contact scheduling, and modeling parameter selection. OD/TD/FD performance predictions are presented based on covariance and simulation analyses. EOS navigation scenarios and the contributions of principal error sources impacting performance are also described. The results indicate that a TONS mode can be configured to meet current and proposed EOS position accuracy requirements of 100 and 50 m, respectively