Oxford Avenue Sewer Extension Project in the City of Portsmouth

Financial support provided by the New Hampshire Estuaries Project (NHEP) to the City of Portsmouth helped with the cost of installing a new sewer line at Oxford Avenue that replaced the on-site subsurface disposal systems (septic systems) for fourteen homes. The homes border the Great Bog and Pickering Creek watersheds. The construction occurred during the autumn of 2004

Compressing networks with super nodes

Community detection is a commonly used technique for identifying groups in a network based on similarities in connectivity patterns. To facilitate community detection in large networks, we recast the network to be partitioned into a smaller network of 'super nodes', each super node comprising one or more nodes in the original network. To define the seeds of our super nodes, we apply the 'CoreHD' ranking from dismantling and decycling. We test our approach through the analysis of two common methods for community detection: modularity maximization with the Louvain algorithm and maximum likelihood optimization for fitting a stochastic block model. Our results highlight that applying community detection to the compressed network of super nodes is significantly faster while successfully producing partitions that are more aligned with the local network connectivity, more stable across multiple (stochastic) runs within and between community detection algorithms, and overlap well with the results obtained using the full network

Enhanced detectability of community structure in multilayer networks through layer aggregation

Many systems are naturally represented by a multilayer network in which edges exist in multiple layers that encode different, but potentially related, types of interactions, and it is important to understand limitations on the detectability of community structure in these networks. Using random matrix theory, we analyze detectability limitations for multilayer (specifically, multiplex) stochastic block models (SBMs) in which L layers are derived from a common SBM. We study the effect of layer aggregation on detectability for several aggregation methods, including summation of the layers' adjacency matrices for which we show the detectability limit vanishes as O(L^{-1/2}) with increasing number of layers, L. Importantly, we find a similar scaling behavior when the summation is thresholded at an optimal value, providing insight into the common - but not well understood - practice of thresholding pairwise-interaction data to obtain sparse network representations.Comment: 7 pages, 4 figure

Optimal quantum control of atomic wave packets in optical lattices

In this work, I investigate the motional control and the transport of single neutral atoms trapped in an optical conveyor belt. The main goal is to prepare the atoms in the vibrational ground state of the trapping potential with high efficiency and keep the atoms in this state after fast non-adiabatic transport. In this group, the conveyor belt is used in two systems: (i) In an atom-cavity system, the three-dimensional ground state is prepared by means of carrier-free Raman sideband cooling for the first time. (ii) I use one-dimensional microwave sideband cooling in a state-dependent optical lattice and analyze with a new temperature model the influence of the anharmonic shape of the trapping potential. In the next step, I present a numerical simulation of atom transport. Optimal quantum control theory is used to find transport sequences for different durations without heating atoms out of the ground state. The measurements with these new sequences demonstrate that atoms can be transported by a factor two faster, with higher fidelity and robustness against experimental imperfections. Additionally, I analyze the dynamics of atom transport for sequences of multiple transport steps, which are required for quantum walk experiments. A proof-of-principle measurement demonstrates open-loop live feedback optimization of transport sequences with the experiment. This technique can further compensate experimental imperfections that are not taken into account in the numerical calculation. In the last part, I examine the fundamental limit of fast atom transport, the so-called quantum speed limit. It is defined as the minimum time that a quantum state requires to evolve into an orthogonal one. I investigate the dependencies of this boundary on different trap depths and the finite radial temperature

'Don’t have time to drain the swamp; too busy dealing with alligators’: defining the governance skills sets that enhance volunteer retention and recruitment in small arts and cultural organisations

Small arts and cultural organisations are facing a number of significant challenges through the ongoing austerity programmes impacting on their funding and practices. These challenges are made more complex and problematic through the isolation and time poverty they experience as a result of small budgets, less paid staff and through primarily volunteer run governance. There is a contradiction in inherent in the importance of recruiting and retaining volunteers and the on-going capacity of volunteer governance. This paper seeks to identify and explore these tensions and contradictions by identifying governance skills sets that can support the volunteer function, and inform a training process that is practice-based and overcomes the limitations of isolation, funding and time

Beetle II: an adaptable tutorial dialogue system

We present BEETLE II, a tutorial dialogue system which accepts unrestricted language input and supports experimentation with different dialogue strategies. Our first system evaluation compared two dialogue policies. The resulting corpus was used to study the impact of different tutoring and error recovery strategies on user satisfaction and student interaction style. It can also be used in the future to study a wide range of research issues in dialogue systems.