4,220 research outputs found
Multi-mode Tracking of a Group of Mobile Agents
We consider the problem of tracking a group of mobile nodes with limited
available computational and energy resources given noisy RSSI measurements and
position estimates from group members. The multilateration solutions are known
for energy efficiency. However, these solutions are not directly applicable to
dynamic grouping scenarios where neighbourhoods and resource availability may
frequently change. Existing algorithms such as cluster-based GPS duty-cycling,
individual-based tracking, and multilateration-based tracking can only
partially deal with the challenges of dynamic grouping scenarios. To cope with
these challenges in an effective manner, we propose a new group-based
multi-mode tracking algorithm. The proposed algorithm takes the topological
structure of the group as well as the availability of the resources into
consideration and decides the best solution at any particular time instance. We
consider a clustering approach where a cluster head coordinates the usage of
resources among the cluster members. We evaluate the energy-accuracy trade-off
of the proposed algorithm for various fixed sampling intervals. The evaluation
is based on the 2D position tracks of 40 nodes generated using Reynolds'
flocking model. For a given energy budget, the proposed algorithm reduces the
mean tracking error by up to in comparison to the existing
energy-efficient cooperative algorithms. Moreover, the proposed algorithm is as
accurate as the individual-based tracking while using almost half the energy.Comment: Accepted for publication in the 20th international symposium on
wireless personal multimedia communications (WPMC-2017
RSSI-Based Self-Localization with Perturbed Anchor Positions
We consider the problem of self-localization by a resource-constrained mobile
node given perturbed anchor position information and distance estimates from
the anchor nodes. We consider normally-distributed noise in anchor position
information. The distance estimates are based on the log-normal shadowing
path-loss model for the RSSI measurements. The available solutions to this
problem are based on complex and iterative optimization techniques such as
semidefinite programming or second-order cone programming, which are not
suitable for resource-constrained environments. In this paper, we propose a
closed-form weighted least-squares solution. We calculate the weights by taking
into account the statistical properties of the perturbations in both RSSI and
anchor position information. We also estimate the bias of the proposed solution
and subtract it from the proposed solution. We evaluate the performance of the
proposed algorithm considering a set of arbitrary network topologies in
comparison to an existing algorithm that is based on a similar approach but
only accounts for perturbations in the RSSI measurements. We also compare the
results with the corresponding Cramer-Rao lower bound. Our experimental
evaluation shows that the proposed algorithm can substantially improve the
localization performance in terms of both root mean square error and bias.Comment: Accepted for publication in 28th Annual IEEE International Symposium
on Personal, Indoor and Mobile Radio Communications (IEEE PIMRC 2017
Pengawasan Dinas Cipta Karya dan Tata Ruang Kabupaten Rokan Hilir terhadap Pembangunan Fisik (Study Kasus Pembangunan Kantor Camat Kubu Babussalam Tahun 2014 )
The results showed that there are some things that impede the supervision of physical development that have an impact on the failure of the project to construct offices, the writers observation of the surveillance of physical development can be categorized still very poor, because still lacking maximum performance of officers of Settlements and Spatial Rokan Downstream in carrying out surveillance in the physical development Babussalam Kubu district, and there are still factors - factors inhibiting the supervision of the physical development of the district office Babussalam camp, which is still a lack of human resources, funding / costs and infrastructure facilities.In the process Supervision which sets standards, action judgments, take corrective action, and regular reports, based on the writers observation, the authors assess is still not good, which is the case according to the authors present a problem in conducting surveillance measures or monitoring physical development in Kecamtan stronghold Babussalam rokan downstream district is only done once a month, and the absence of regular reports prepared by the department of copyrighted works and the district spatial rokan downstream towards the execution of physical development projects. So the impact on the failure of the project to construct offices Babussalam camp. Inside factors - factors inhibiting the supervision of the Department of Human Settlements and Spatial districts rokan downstream to the physical development, the constraints in terms of human resources are categorized still lack quality inspectors agency copyrighted works and spatial planning, in terms of salaries inspectors also minimal, and not the facility or vehicle completeness Department in monitoring the physical project to construct offices Babussalam stronghold Rokan Hilir.Keywords: Surveillance Office of Human Settlements and Physical Developmen
Stacked optical antennas for plasmon propagation in a 5 nm-confined cavity
The sub-wavelength concentration and propagation of electromagnetic energy are two complementary aspects of plasmonics that are not necessarily co-present in a single nanosystem. Here we exploit the strong nanofocusing properties of stacked optical antennas in order to highly concentrate the electromagnetic energy into a 5 nm metal-insulator-metal (MIM) cavity and convert free radiation into guided modes. The proposed nano-architecture combines the concentration properties of optical nanoantennas with the propagation capability of MIM systems, paving the way to highly miniaturized on-chip plasmonic waveguiding
Prospective randomized controlled pilot study on the effects of almond consumption on skin lipids and wrinkles.
ObjectiveAlmonds are a rich source of fatty acids and antioxidants, and their supplementation is known to significantly modulate serum lipids. The effects of almond on the skin's lipid barrier and the appearance of wrinkles have not yet been elucidated. The aim of this study was to investigate the effects of almond consumption on facial sebum production and wrinkles.MethodsThis was a prospective, investigator-blinded, randomized controlled trial in which subjects consumed 20% of their daily energy consumption in either almonds or a calorie-matched snack for 16 weeks. This study was completed at the UC Davis Dermatology clinic. Participants were a volunteer sample of generally healthy postmenopausal females with Fitzpatrick skin types 1 and 2. A facial photograph and image analysis system was used to obtain standardized photographs and information on wrinkle width and severity at 0, 8, and 16 weeks. Measurements of transepidermal water loss and sebum production were also completed at 0, 8, and 16 weeks.ResultsFifty healthy postmenopausal females were recruited, 31 participants were enrolled, and 28 completed the study. Under photographic analysis, the almond group had significantly decreased wrinkle severity and width compared with the control group at 16 weeks (p < .02). Changes in skin barrier function were nonsignificant, measured by the transepidermal water loss (p = .65) between the almond and control groups relative to baseline after 16 weeks. No adverse effects were reported.ConclusionOur study demonstrates that daily almond consumption may reduce wrinkle severity in postmenopausal females to potentially have natural antiaging benefits
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