University of New Hampshire

About: University of New Hampshire is a education organization based out in Durham, New Hampshire, United States. It is known for research contribution in the topics: Population & Solar wind. The organization has 9379 authors who have published 24025 publications receiving 1020112 citations. The organization is also known as: UNH.

Sensor-based control of robotic manipulators using a general learning algorithm

Abstract: A practical learning control system is described which is applicable to the control of complex robotic systems involving multiple feedback sensors and multiple command variables during both repetitive and nonrepetitive operations. In the controller, a general learning algorithm is used to learn to reproduce the relationship between the sensor outputs and the system command variables over particular regions of the system state space. The learned information is then used to predict the command signals required to produce desired changes in the sensor outputs. The learning controller requires no a priori knowledge of the relationships between the sensor outputs and the command variables, facilitating control system modification for specific applications. The results of two learning experiments using a General Electric P-5 manipulator are presented. The first involved learning to use the video image feedback to position the robot hand accurately relative to stationary objects on a table, assuming no knowledge of the robot kinematics or camera characteristics. The second involved learning to use video image feedback to intercept and track objects moving on a conveyor. In both experiments, control system performance was found to be limited by the resolution of the sensor feedback data, rather than by control structure limitations.

Business models for people, planet (& profits): exploring the phenomena of social business, a market-based approach to social value creation

Abstract: This article explores the hybrid phenomenon of social business, that is, both a form of organization and a practice that deliberately harnesses market dynamics to address deeply rooted social issues through the design and implementation of a core product or service. This new form of hybrid venture melds the social purpose traditionally associated with non-profit organizations with the economic purpose and market-based methods traditionally associated with for-profit firms. This exploratory research inductively explores the process by which social businesses are designed. The result suggests that clear intentionality around social purpose drives the design of these ventures and their associated missions and business models such that they can creatively synthesize competing paradigms (economic and social purpose) within one venture. The tight coupling of mission, method, and operationalization allows for the multi-stakeholder promise of the business model to be fulfilled.

The International Bathymetric Chart of the Southern Ocean (IBCSO) Version 1.0 – A new bathymetric compilation covering circum-Antarctic waters

Abstract: The International Bathymetric Chart of the Southern Ocean (IBCSO) Version 1.0 is a new digital bathymetric model (DBM) portraying the seafloor of the circum-Antarctic waters south of 60 degrees S. ...

Stability of the Larsen B ice shelf on the Antarctic Peninsula during the Holocene epoch

Abstract: The stability of the Antarctic ice shelves in a warming climate has long been discussed, and the recent collapse of a significant part, over 12,500 km2 in area, of the Larsen ice shelf off the Antarctic Peninsula has led to a refocus toward the implications of ice shelf decay for the stability of Antarctica's grounded ice. Some smaller Antarctic ice shelves have undergone periodic growth and decay over the past 11,000 yr (refs 7-11), but these ice shelves are at the climatic limit of ice shelf viability and are therefore expected to respond rapidly to natural climate variability at century to millennial scales. Here we use records of diatoms, detrital material and geochemical parameters from six marine sediment cores in the vicinity of the Larsen ice shelf to demonstrate that the recent collapse of the Larsen B ice shelf is unprecedented during the Holocene. We infer from our oxygen isotope measurements in planktonic foraminifera that the Larsen B ice shelf has been thinning throughout the Holocene, and we suggest that the recent prolonged period of warming in the Antarctic Peninsula region, in combination with the long-term thinning, has led to collapse of the ice shelf.

A general biogeochemical model describing the responses of the C and N cycles in terrestrial ecosystems to changes in CO2, climate, and N deposition

Abstract: A model that simulates carbon (C) and nitrogen (N) cycles in terrestrial ecosystems is developed. The model is based on the principle that the responses of terrestrial ecosystems to changes in CO(2), climate, and N deposition will encompass enzymatic responses, shifts in tissue stoichiometry, changes in biomass allocation among plant tissues, altered rates of soil organic matter turnover and N mineralization, and ultimately a redistribution of C and N between vegetation and soils. The model is a highly aggregated, process-based, biogeochemical model designed to examine changes in the fluxes and allocation of C and N among foliage, fine roots, stems, and soils in response to changes in atmospheric CO(2) concentration, temperature, soil water, irradiance, and inorganic nitrogen inputs. We use the model to explore how changes in CO(2) concentration, temperature, and N inputs affect carbon storage in two ecosystems: arctic tundra and temperate hardwood forest. The qualitative responses of the two ecosystems were similar. Quantitative differences are attributed to the initial distribution of C and N between vegetation and soils, to the amounts of woody tissue in the two ecosystems, and to their relative degree of N limitation. We conclude with a critical analysis of the model's strengths and weaknesses, and discuss possible future directions.