On-the-go text-editing is difficult, yet frequently done in everyday lives. Using smartphones for editing text forces users into a heads-down posture which can be undesirable and unsafe. We present EYEditor, a heads-up smartglass-based solution that displays the text on a see-through peripheral display and allows text-editing with voice and manual input. The choices of output modality (visual and/or audio) and content presentation were made after a controlled experiment, which showed that sentence-by-sentence visual-only presentation is best for optimizing users' editing and path-navigation capabilities. A second experiment formally evaluated EYEditor against the standard smartphone-based solution for tasks with varied editing complexities and navigation difficulties. The results showed that EYEditor outperformed smartphones as either the path OR the task became more difficult. Yet, the advantage of EYEditor became less salient when both the editing and navigation was difficult. We discuss trade-offs and insights gained for future heads-up text-editing solutions.

Existing voice-based interfaces have limited support for text editing, especially when seeing the text is difficult, e.g., while walking or cooking. This research develops voice interaction techniques for eyes-free text editing. First, with a Wizard-of-Oz study, we identified two primary user strategies: using commands, e.g., “ replace go with goes ” and re-dictating over an erroneous portion, e.g., correcting “he go there” by saying “he goes there.” To support these user strategies with an actual system implementation, we developed two eyes-free voice interaction techniques, Commanding and Re-dictation , and evaluated them with a controlled experiment. Results showed that while Re-dictation performs significantly better for more semantically complex edits, Commanding is more suitable for making one-word edits, especially deletions. We developed VoiceRev to combine both the techniques in the same interface and evaluated it with realistic tasks. Results showed improved usability of the combined techniques over either of the two techniques used individually.

We present EDITalk, a novel voice-based, eyes-free word processing interface. We used a Wizard-of-Oz elicitation study to investigate the viability of eyes-free word processing in the mobile context and to elicit user requirements for such scenarios. Results showed that meta-level operations like highlight and comment, and core operations like insert, delete and replace are desired by users. However, users were challenged by the lack of visual feedback and the cognitive load of remembering text while editing it. We then studied a commercial-grade dictation application and discovered serious limitations that preclude comfortable speak-to-edit interactions. We address these limitations through EDITalk's closed-loop interaction design, enabling eyes-free operation of both meta-level and core word processing operations in the mobile context. Finally, we discuss implications for the design of future mobile, voice-based, eyes-free word processing interface.

We propose a delay fault testing methodology using on-chip delay measurement hardware. We have designed a process-tolerant, low-overhead delay measurement hardware and developed an algorithm to judiciously insert the hardware at internal nodes of logic blocks. Experimental results for a set of ISCAS89 benchmarks show up to 16.9% improvement in transition fault coverage and up to 10.5% increase in the number of detected faults for segment delay fault model, with fixed test length. The reduction in test length is up to 59% for transition fault, with fixed target coverage. The delay and area overhead due to additional DFT logic is limited to 2% and 4% respectively.

Reduction in test power is important to improve battery lifetime in portable electronic devices employing periodic self-test, to increase reliability of testing, and to reduce test cost. In scan-based testing, a significant fraction of total test power is dissipated in the combinational block. In this paper, we present a novel circuit technique to virtually eliminate test power dissipation in combinational logic by masking signal transitions at the logic inputs during scan shifting. We implement the masking effect by inserting an extra supply gating transistor in the supply to ground path for the first-level gates at the outputs of the scan flip-flops. The supply gating transistor is turned off in the scan-in mode, essentially gating the supply. Adding an extra transistor in only one logic level renders significant advantages with respect to area, delay, and power overhead compared to existing methods, which use gating logic at the output of scan flip-flops. Moreover, the proposed gating technique allows a reduction in leakage power by input vector control during scan shifting. Simulation results on ISCAS89 benchmarks show an average improvement of 62% in area overhead, 101% in power overhead (in normal mode), and 94% in delay overhead, compared to the lowest cost existing method.

Reduction in test power is important to improve battery life in portable devices employing periodic self-test, to increase reliability of testing and to reduce test-cost. In scan-based testing, about 80% of total test power is dissipated in the combinational block. In this paper, we present a novel circuit technique to virtually eliminate test power dissipation in combinational logic by masking signal transition at the logic inputs during scan shifting. We realize the masking effect by inserting an extra supply gating transistor in the VDD to GND path for the first level cells at output of the scan flops. The supply gating transistor is turned off in the scan-in mode, essentially gating the supply. Adding an extra transistor in only one logic level renders significant advantage with respect to area, delay and power (in normal mode of operation) overhead compared to existing methods, which use gating logic at the output of scan flops. Simulation results on ISCAS89 benchmarks show up to 79% improvement in area, up to 32% in power (in normal mode) and up to 7% in delay compared to lowest-cost known alternative.