Development of a flexible test-bed for robotics, telemanipulation and servicing research

The development of a flexible operation test-bed, based around a commercially available ASEA industrial robot is described. The test-bed was designed to investigate fundamental human factors issues concerned with the unique problems of robotic manipulation in the hostile environment of Space

Transmit Antenna Selection for Physical-Layer Network Coding Based on Euclidean Distance

Physical-layer network coding (PNC) is now well-known as a potential candidate for delay-sensitive and spectrally efficient communication applications, especially in two-way relay channels (TWRCs). In this paper, we present the error performance analysis of a multiple-input single-output (MISO) fixed network coding (FNC) system with two different transmit antenna selection (TAS) schemes. For the first scheme, where the antenna selection is performed based on the strongest channel, we derive a tight closed-form upper bound on the average symbol error rate (SER) with $M$-ary modulation and show that the system achieves a diversity order of 1 for $M > 2$. Next, we propose a Euclidean distance (ED) based antenna selection scheme which outperforms the first scheme in terms of error performance and is shown to achieve a diversity order lower bounded by the minimum of the number of antennas at the two users.Comment: 15 pages, 4 figures, Globecom 2017 (Wireless Communications Symposium

Protocols for distributive scheduling

The increasing complexity of space operations and the inclusion of interorganizational and international groups in the planning and control of space missions lead to requirements for greater communication, coordination, and cooperation among mission schedulers. These schedulers must jointly allocate scarce shared resources among the various operational and mission oriented activities while adhering to all constraints. This scheduling environment is complicated by such factors as the presence of varying perspectives and conflicting objectives among the schedulers, the need for different schedulers to work in parallel, and limited communication among schedulers. Smooth interaction among schedulers requires the use of protocols that govern such issues as resource sharing, authority to update the schedule, and communication of updates. This paper addresses the development and characteristics of such protocols and their use in a distributed scheduling environment that incorporates computer-aided scheduling tools. An example problem is drawn from the domain of space shuttle mission planning

User evaluation outside the lab: the trial of Físchlár-News

A user study of Físchlár-News system was conducted in Spring 2004 with 16 users, each user using the system for a 1-month period. Físchlár-News is an experimental online news archive that incorporates various automatic content-based video indexing techniques and a news story recommender algorithm to process and index the daily 9 o’clock broadcast news from TV and allows its users to browse, search, be recommended, and play news stories on a conventional web browser. Pre and post-trial questionnaires, interaction logging and incident diary methods collected both qualitative and quantitative usage data during the trial period. While the details of the findings from this evaluation is reported elsewhere, in this paper we report the details of the methodology taken and our experience of conducting this evaluation

Pump-probe detuning dependence of four-wave mixing pulse in an SOA

Four-wave mixing (FWM) between 2-ps pulses in a multiquantum-well semiconductor optical amplifier (SOA) is presented. The conjugate pulses are fully characterized using the frequency-resolved optical gating technique. The detuning between the pump and probe is varied, leading to a compression of the FWM signal from 3.71 to 2.77 ps as the detuning is increased from 5 to 25 nm. The output conjugate pulse is always broader than the injected probe signal due to gain saturation effects. A reshaping of the conjugate pulse is also measured. However, large nonlinearities are introduced to the frequency chirp across the pulse for large detunings which may degrade the performance of four-wave-mixing-based all-optical processing applications in SOAs