Using Acceptors as Transducers

We wish to use a given nondeterministic two-way multi-tape acceptor as a transducer by supplying the contents for only some of its input tapes, and asking it to generate the missing contents for the other tapes. We provide here an algorithm for assuring beforehand that this transduction always results in a finite set of answers. We also develop an algorithm for evaluating these answers whenever the previous algorithm indicated their finiteness. Furthermore, our algorithms can be used for speeding up the simulation of these acceptors even when not used as transducers

Concept-Based Partitioning for Large Multidomain Multifunctional Embedded Systems

Hardware-software partitioning is an important phase in embedded systems. Decisions made during this phase impact the quality, cost, performance, and the delivery date of the final product. Over the past decade or more, various partitioning approaches have been proposed. A majority operate at a relatively fine granularity and use a low-level executable specification as the starting point. This presents problems if the context is families of industrial products with frequent release of upgraded or new members. Managing complexity using a low-level specification is extremely challenging and impacts developer productivity. Designing using a high-level specification and component-based development, although a better option, imposes component integration and replacement problems during system evolution and new product release. A new approach termed Concept-Based Partitioning is presented that focuses on system evolution, product lines, and large-scale reuse when partitioning. Beginning with information from UML 2.0 sequence diagrams and a concept repository concepts are identified and used as the unit of partitioning within a specification. A methodology for the refinement of interpart communication in the system specification using sequence diagrams is also presented. Change localization during system evolution, composability during large-scale reuse, and provision for configurable feature variations for a product line are facilitated by a Generic Adaptive Layer (GAL) around selected concepts. The methodology was applied on a subsystem of an Unmanned Aerial Vehicle (UAV) using various concepts which improved the composability of concepts while keeping performance and size overhead within the 2% range

A Matter of Balance: Specialization, Task Variety, and Individual Learning in a Software Maintenance Environment

Specialization at work has been recognized as a key driver of learning and productivity since the days of Adam Smith. More recently, researchers have noted that exposure to task variety can enhance learning. We examine how exposure to specialization and variety jointly drive employee productivity in a real-life setting. We analyze a data set covering 88 individuals who worked on 5,711 maintenance tasks in an offshore software support services operation. We find that, as expected, specialization enhances productivity. However, exposure to variety has a nonlinear influence on productivity; i.e., "too much variety" can impede learning. We also find that achieving a proper balance between specialization and exposure to a variety leads to the highest productivity. We capture this balance using an adaptation of the Herfindahl-Hirschman Index from the economics literature. In addition, we examine how the productivity of individuals in a workgroup is affected by member entry and exit, with the latter specified in terms of the degree of specialized experience and the degree of variety experience lost from the workgroup when a member exits. Our analysis reveals that the degree of variety experience lost has a greater impact on productivity than the degree of specialized experience that is lost.project management, organizational studies, productivity, effectiveness-performance, information systems, IT policy and management, outsourcing, learning and productivity