Variability in wrist-tilt accelerometer based gesture interfaces

In this paper we describe a study that examines human performance in a tilt control targeting task on a PDA. A three-degree of freedom accelerometer attached to the base of the PDA allows users to navigate to the targets by tilting their wrist in different directions. Post hoc analysis of performance data has been used to classify the ease of targeting and variability of movement in the different directions. The results show that there is an increase in variability of motions upwards from the centre, compared to downwards motions. Also the variability in the x axis component of the motion was greater than that in the y axis. This information can be used to guide designers as to the ease of various relative motions, and can be used to reshape the dynamics of the interaction to make each direction equally easy to achieve

Leading Practices: Agency Acquisition Policies Could Better Implement Key Product Development Principles

Excerpt from the Proceedings of the Nineteenth Annual Acquisition Research SymposiumEach year, the Department of Defense (DoD), the Department of Homeland Security (DHS), and the National Aeronautics and Space Administration (NASA) together invest billions of dollars to acquire complex, hardware- and software-centric systems to provide critical defense, security, and space capabilities. Given the amount of federal funds spent and the critical missions these agencies support, Congress and agencies have consistently underscored the importance of achieving efficiencies and effectiveness across these acquisition activities. The GAO has also contributed to these efforts, and agencies and Congress have acted on many of the GAO's recommendations, including taking steps toward implementing knowledge-based acquisition frameworks, which the GAO's prior work found is essential to improving performance. Nonetheless, the GAO's annual assessments of major acquisition programs at each agency continue to find that programs often take significantly longer, cost more than initially estimated, and in some cases deliver final products with less capability than anticipated. Leading companies would not be able to sustain such outcomes without potentially going out of business. This dynamic correspondingly drives leading companies to undertake a disciplined approach to product development—one that is instructive to government acquisition, despite environmental differences. Throughout an individual product’s development, leading companies often confront difficult tradeoff decisions, such as options about design requirements, technical solutions, and where and when to launch a promised solution. These decisions are largely informed by the incentive to be first to market within a globalized marketplace and win enduring customer support.Approved for public release; distribution is unlimited

Leading Practices: Agency Acquisition Policies Could Better Implement Key Product Development Principles

Excerpt from the Proceedings of the Nineteenth Annual Acquisition Research SymposiumEach year, the Department of Defense (DoD), the Department of Homeland Security (DHS), and the National Aeronautics and Space Administration (NASA) together invest billions of dollars to acquire complex, hardware- and software-centric systems to provide critical defense, security, and space capabilities. Given the amount of federal funds spent and the critical missions these agencies support, Congress and agencies have consistently underscored the importance of achieving efficiencies and effectiveness across these acquisition activities. The GAO has also contributed to these efforts, and agencies and Congress have acted on many of the GAO's recommendations, including taking steps toward implementing knowledge-based acquisition frameworks, which the GAO's prior work found is essential to improving performance. Nonetheless, the GAO's annual assessments of major acquisition programs at each agency continue to find that programs often take significantly longer, cost more than initially estimated, and in some cases deliver final products with less capability than anticipated. Leading companies would not be able to sustain such outcomes without potentially going out of business. This dynamic correspondingly drives leading companies to undertake a disciplined approach to product development—one that is instructive to government acquisition, despite environmental differences. Throughout an individual product’s development, leading companies often confront difficult tradeoff decisions, such as options about design requirements, technical solutions, and where and when to launch a promised solution. These decisions are largely informed by the incentive to be first to market within a globalized marketplace and win enduring customer support.Approved for public release; distribution is unlimited

Progress Toward Demonstrating a High Performance Optical Tape Recording Technology

This paper discusses the technology developments achieved during the first year of a program to develop a high performance digital optical tape recording device using a solid state, diode pumped, frequency doubled green laser source. The goal is to demonstrate, within two years, useful read/write data transfer rates to at least 100 megabytes per second and a user capacity of up to one terabyte per cartridge implemented in a system using a '3480' style mono-reel tape cartridge

Application of co-operative agents in handling fluctuations in a pull production system

This paper presents the general details of the structure and strategy of a multi-agent system that is being developed to improve the performance of pull (kanban) production control to handle large fluctuations in product demand. Employing a set of generic, heterarchial agents each controlling a single product and co-operating together to ensure that all components, regardless of demand fluctuation, are manufactured on time as per basic kanban principles. Preliminary results indicate that the basic kanban model does not cater for large demand fluctuations and the application of this multi-agent strategy may be beneficial to improving the overall system performance and increase the likelihood that all products will be manufactured on time.<br /

First-Principles Study of Adsorption of Actinide Complexes on Borophene

Two- and three-dimensional materials can be used for the sensitive detection of adsorbates through charge-transfer mechanisms. Recently, a two-dimensional borophene material was synthesized in two distinct phases: line-defected planar and buckled. Here, we determine whether borophene can act as a competitive radioactive material sensor by using first-principles calculations to simulate the adsorption of actinide (uranium─U, neptunium─Np, and plutonium─Pu) complexes. Specific ligands are used (OH–, NO3–, CO32–) to generate model actinide complexes representing realistic environmental conditions. Various adsorption configurations are studied for each phase, and the corresponding adsorption energies, charge transfer, and electronic properties are reported. The calculated results reveal the presence of strong interactions due to the formation of a chemical bond between borophene and the oxo ligand of the adsorbate. Periodic trends are established, which indicate the strong affinity to Pu complexes in comparison to Np and U and that complexes containing carbonate bind more strongly overall. We find that the buckled phase engages in stronger adsorption than the planar phase; thus, in comparison to other 2D materials (silicene and germanene) and planar borophene, buckled borophene is a highly suitable candidate as a sensor for actinide complexes

Vibration Isolation Design for the Micro-X Rocket Payload

Micro-X is a NASA-funded, sounding rocket-borne X-ray imaging spectrometer that will allow high precision measurements of velocity structure, ionization state and elemental composition of extended astrophysical systems. One of the biggest challenges in payload design is to maintain the temperature of the detectors during launch. There are several vibration damping stages to prevent energy transmission from the rocket skin to the detector stage, which causes heating during launch. Each stage should be more rigid than the outer stages to achieve vibrational isolation. We describe a major design effort to tune the resonance frequencies of these vibration isolation stages to reduce heating problems prior to the projected launch in the summer of 2014.Comment: 6 pages, 7 figures, LTD15 Conference Proceeding

HypTrails: A Bayesian Approach for Comparing Hypotheses About Human Trails on the Web

When users interact with the Web today, they leave sequential digital trails on a massive scale. Examples of such human trails include Web navigation, sequences of online restaurant reviews, or online music play lists. Understanding the factors that drive the production of these trails can be useful for e.g., improving underlying network structures, predicting user clicks or enhancing recommendations. In this work, we present a general approach called HypTrails for comparing a set of hypotheses about human trails on the Web, where hypotheses represent beliefs about transitions between states. Our approach utilizes Markov chain models with Bayesian inference. The main idea is to incorporate hypotheses as informative Dirichlet priors and to leverage the sensitivity of Bayes factors on the prior for comparing hypotheses with each other. For eliciting Dirichlet priors from hypotheses, we present an adaption of the so-called (trial) roulette method. We demonstrate the general mechanics and applicability of HypTrails by performing experiments with (i) synthetic trails for which we control the mechanisms that have produced them and (ii) empirical trails stemming from different domains including website navigation, business reviews and online music played. Our work expands the repertoire of methods available for studying human trails on the Web.Comment: Published in the proceedings of WWW'1