Reading with new tools: An evaluation of Personal Digital Assistants as tools for reading course materials

Lightweight, palmtop devices such as personal digital assistants (PDAs) can now be used for reading electronic text, opening up their potential as learning tools. This paper reports a study that evaluated the use of PDAs for reading course materials by students on an Open University master's course. The research is grounded in activity theory, which provides a useful framework for examining how the introduction of a new tool changes an existing activity. Student perceptions of the possibilities and constraints of the PDA, as determined by questionnaires and interviews, reveal the impact the new tool had upon reading. The PDA constrained reading with limitations such as the small screen size, new requirements for navigating through the text and awkward methods for taking notes. These conditions made it difficult for students to skim‐read the text, to move back and forth within the document and to interact with the text as easily as they could with paper. Nevertheless, students welcomed the opportunity to have the course materials on a portable, lightweight device that could be used at any time and in any place. This made it easier to fit the reading activity around the various other activities in which students were involved In addition, the PDA was used in conjunction with existing tools, such as the printed version of the course materials and the desktop computer. Therefore, it was not seen to replace paper but rather to extend and complement it. The findings are discussed using concepts from activity theory to interpret how the new tool modified the reading activity

Optimized Surface Code Communication in Superconducting Quantum Computers

Quantum computing (QC) is at the cusp of a revolution. Machines with 100 quantum bits (qubits) are anticipated to be operational by 2020 [googlemachine,gambetta2015building], and several-hundred-qubit machines are around the corner. Machines of this scale have the capacity to demonstrate quantum supremacy, the tipping point where QC is faster than the fastest classical alternative for a particular problem. Because error correction techniques will be central to QC and will be the most expensive component of quantum computation, choosing the lowest-overhead error correction scheme is critical to overall QC success. This paper evaluates two established quantum error correction codes---planar and double-defect surface codes---using a set of compilation, scheduling and network simulation tools. In considering scalable methods for optimizing both codes, we do so in the context of a full microarchitectural and compiler analysis. Contrary to previous predictions, we find that the simpler planar codes are sometimes more favorable for implementation on superconducting quantum computers, especially under conditions of high communication congestion.Comment: 14 pages, 9 figures, The 50th Annual IEEE/ACM International Symposium on Microarchitectur

A Conceptual Framework of Reverse Logistics Impact on Firm Performance

This study aims to examine the reverse logistics factors that impact upon firm performance. We review reverse logistics factors under three research streams: (a) resource-based view of the firm, including: Firm strategy, Operations management, and Customer loyalty (b) relational theory, including: Supply chain efficiency, Supply chain collaboration, and institutional theory, including: Government support and Cultural alignment. We measured firm performance with 5 measures: profitability, cost, innovativeness, perceived competitive advantage, and perceived customer satisfaction. We discuss implications for research, policy and practice