399 research outputs found
An Analysis of Heterogeneity in Futuristic Unmanned Vehicle Systems
Recent studies have shown that with appropriate operator decision support and with enough automation aboard
unmanned vehicles, inverting the multiple operators to single-vehicle control paradigm is possible. These studies,
however, have generally focused on homogeneous teams of vehicles, and have not completely addressed either the
manifestation of heterogeneity in vehicle teams, or the effects of heterogeneity on operator capacity. An important
implication of heterogeneity in unmanned vehicle teams is an increase in the diversity of possible team
configurations available for each operator, as well as an increase in the diversity of possible attention allocation
schemes that can be utilized by operators. To this end, this paper introduces a resource allocation framework that
defines the strategies and processes that lead to alternate team configurations. The framework also highlights the
sub-components of operator attention allocation schemes that can impact overall performance when supervising
heterogeneous unmanned vehicle teams. A subsequent discrete event simulation model of a single operator
supervising multiple heterogeneous vehicles and tasks explores operator performance under different heterogeneous
team compositions and varying attention allocation strategies. Results from the discrete event simulation model
show that the change in performance when switching from a homogeneous team to a heterogeneous one is highly
dependent on the change in operator utilization. Heterogeneous teams that result in lower operator utilization can
lead to improved performance under certain operator strategies.Prepared for Charles River Analytic
Audio Decision Support for Supervisory Control of Unmanned Vehicles : Literature Review
Purpose of this literature review:
To survey scholarly articles, books and other sources (dissertations, conference
proceedings) relevant to the use of the audio
supervisory control of unmanned vehicles.Prepared for Charles River Analytic
How ‘Zerodha’ Used Technology to Disrupt the Indian Stock Trading Industry?
In this practitioner-oriented research, we describe how “Zerodha” entered and disrupted the Indian stock trading industry through the use of technology by overcoming the challenges of (1) developing a new business offering that is accessible to all, (2) gaining trust across the community, and (3) fostering and growing their business ecosystem. Our case-based research illustrates how an organization can enter a well-established business area and create value by (1) rethinking the business model, (2) treating technology as a business enabler, (3) empowering the end user, and (4) proactively investing in the business and community. Based on Zerodha’s experiences, we provide guidelines and recommendations for other businesses contemplating to enter and disrupt an established industry by leveraging technology
A UAV Mission Hierarchy
In the following sections, each of the primary missions are decomposed into mission planning, management, and replanning segments in order to identify
what the primary functions a human operator will need to perform. The goal is to understand what tasks/functions are common across different UAV
missions and platforms in order to map the generalizability of any particular research project.Prepared for Charles River Analytic
Information Requirements for MCM and ISR Missions : PUMA Phase II
This document contains display requirements for Littoral Combat Ship (LCS) control
station displays to be used by unmanned vehicle units in support of heterogeneous
unmanned vehicle missions (such as Special Operations Force (SOF) insertion). The
method used for generating the requirements was that of a Hybrid Cognitive Task
Analysis (CTA)1 which entails describing a scenario overview of a representative
mission, generating event flow diagrams, and depicting decision ladders for the key
decisions identified in the event flow diagrams. These steps are then used together to
generate an informational requirements summary which includes the situational
awareness requirements that are derived from the event flow and display requirements of
the decision ladders. This method was developed in Phase I of the PUMA (Plan
Understanding for Mixed-initiative control of Autonomous systems) project2. In PUMA
I, the mission scenario primarily consisted of Intelligence, Surveillance and
Reconnaissance (ISR) tasks. For PUMA II, the scenario has been expanded to include
Mine Counter Measures (MCM), Harbor Bottom Image-Mapping (HBI), and Anti-
Terrorism / Force Protection (AT/FP) mission types. There is a specific emphasis on the
MCM and ISR missions to highlight the informational requirement differences between
the two task types. This document incorporates the expanded vehicle and mission type
heterogeneities that are present in PUMA II in order to develop a cohesive set of
informational requirements necessary for such a complex mission.Prepared for Charles River Analytic
The Impact of Heterogeneity on Operator Performance in Future Unmanned Vehicle Systems
Recent studies have shown that with appropriate operator decision support
and with sufficient automation, inverting the multiple operators to
single-unmanned vehicle control paradigm is possible. These studies,
however, have generally focused on homogeneous teams of vehicles, and
have not completely addressed either the manifestation of heterogeneity
in vehicle teams, or the effects of heterogeneity on operator capacity.
An important implication of heterogeneity in unmanned vehicle teams
is an increase in the diversity of possible team configurations available
for each operator, as well as an increase in the diversity of possible attention
allocation schemes that can be utilized by operators. To this end, this
paper introduces a discrete event simulation (DES) model as a means to
model a single operator supervising multiple heterogeneous unmanned
vehicles. The DES model can be used to understand the impact of varying
both vehicle team design variables (such as team composition) and
operator design variables (including attention allocation strategies). The
model also highlights the sub-components of operator attention allocation
schemes that can impact overall performance when supervising heterogeneous unmanned vehicle teams. Results from an experimental case study are then used to validate the model, and make predictions about operator performance for various heterogeneous team configurations.The research was supported by Charles River Analytics, the Office of Naval Research (ONR), and MIT Lincoln Laboratory
Randomised study of the effects of fluoride and time on in situ remineralisation of acid-softened enamel
Objectives
This single-centre, randomised, crossover study used a short-term in situ dental erosion remineralisation model to explore the remineralisation of acid-softened enamel in the 4-h period immediately following brushing with an anti-erosion, dentin hypersensitivity test dentifrice containing 1150 ppm fluoride (as sodium fluoride [NaF]) or a placebo dentifrice with no fluoride.
Materials and methods
Fifty participants wearing a palatal appliance holding surface-softened bovine enamel specimens brushed their natural teeth with their assigned dentifrice. Specimens were removed at 5-, 10-, 15-, 30-, 60-, 120- and 240-min post brushing. Enamel remineralisation effect was evaluated at each timepoint by percent surface microhardness recovery (%SMHR) and enamel fluoride uptake (EFU). After a second in vitro erosive challenge, the percent relative erosion resistance (%RER) was calculated.
Results
Statistically significant differences in %SMHR were observed for the test dentifrice compared with the placebo dentifrice from the 60-min timepoint onwards (all p < 0.02; mean difference of 8.66 [95% CI 3.46, 13.87] at 60 min). At each specimen removal time, %RER and EFU were statistically significantly higher for the test dentifrice compared with the placebo dentifrice (p < 0.0001 for all). No treatment-related or serious adverse events were reported.
Conclusions
The NaF-containing anti-erosion, dentin hypersensitivity dentifrice improved remineralisation of acid-softened enamel starting at 60 min of intra-oral exposure. It also improved enamel erosion resistance and fluoride uptake as early as 5 min after exposure to fluoridated dentifrice slurry
A note on the determination of light quark masses
We provide a model-independent determination of the quantity B_0(m_d-m_u).
Our approach rests only on chiral symmetry and data from the decay of the eta
into three neutral pions. Since the low-energy prediction at next-to-leading
order fails to reproduce the experimental results, we keep the strong
interaction correction as an unknown parameter. As a first step, we relate this
parameter to the quark mass difference using data from the Dalitz plot. A
similar relation is obtained using data from the decay width. Combining both
relations we obtain B_0(m_d-m_u)=(4495+/-440) MeV^2. The preceding value,
combined with lattice determinations, leads to the values m_u(2
GeV)=(2.9+/-0.8) MeV and m_d(2 GeV)=(4.7+/-0.8) MeV.Comment: 8 pages, 1 figure, updated version with all detailed formulas, title
slighly change
One Work Analysis, Two Domains: A Display Information Requirements Case Study
Work domain analyses can be time consuming, requiring extensive interviews, documentation review, and observations, among other techniques. Given the time and resources required, we examine how to generalize a work domain analysis technique, namely the hybrid Cognitive Task Analysis (hCTA) method across two domains in order to generate a common set of display information requirements. The two domains of interest are field workers troubleshooting low voltage distribution networks and telecommunication problems. Results show that there is a high degree of similarity between the two domains due to their service call nature, particularly in tasking and decision-making. While the primary differences were due to communication protocols and equipment requirements, the basic overall mission goals, functions, phases of operation, decision processes, and situation requirements were very similar. A final design for both domains is proposed based on the joint requirements
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