Simulation of tree-ring widths with a model for primary production, carbon allocation, and growth

We present a simple, generic model of annual tree growth, called "T". This model accepts input from a first-principles light-use efficiency model (the "P" model). The P model provides values for gross primary production (GPP) per unit of absorbed photosynthetically active radiation (PAR). Absorbed PAR is estimated from the current leaf area. GPP is allocated to foliage, transport tissue, and fine-root production and respiration in such a way as to satisfy well-understood dimensional and functional relationships. Our approach thereby integrates two modelling approaches separately developed in the global carbon-cycle and forest-science literature. The T model can represent both ontogenetic effects (the impact of ageing) and the effects of environmental variations and trends (climate and CO2) on growth. Driven by local climate records, the model was applied to simulate ring widths during the period 1958–2006 for multiple trees of Pinus koraiensis from the Changbai Mountains in northeastern China. Each tree was initialised at its actual diameter at the time when local climate records started. The model produces realistic simulations of the interannual variability in ring width for different age cohorts (young, mature, and old). Both the simulations and observations show a significant positive response of tree-ring width to growing-season total photosynthetically active radiation (PAR0) and the ratio of actual to potential evapotranspiration (α), and a significant negative response to mean annual temperature (MAT). The slopes of the simulated and observed relationships with PAR0 and α are similar; the negative response to MAT is underestimated by the model. Comparison of simulations with fixed and changing atmospheric CO2 concentration shows that CO2 fertilisation over the past 50 years is too small to be distinguished in the ring-width data, given ontogenetic trends and interannual variability in climate.

Interactive sensory objects for and by people with learning disabilities

This project engages people with learning disabilities as co-researchers and co-designers in the development of multisensory interactive artworks, with the aim of making museums or heritage sites more interesting, meaningful, and fun. This article describes our explorations, within this context, of a range of technologies including squishy circuits, littleBits, and easy-build websites, and presents examples of objects created by the co-researchers such as “sensory boxes” and interactive buckets, baskets, and boots. Public engagement is an important part of the project and includes an annual public event and seminar day, a blog rich with photos and videos of the workshops, and an activities book to give people ideas for creating their own sensory explorations of museums and heritage sites.

Energy-efficient resource allocation in OFDM systems with distributed antennas

In this paper, we develop an energy-efficient resource-allocation scheme with proportional fairness for downlink multiuser orthogonal frequency-division multiplexing (OFDM) systems with distributed antennas. Our aim is to maximize energy efficiency (EE) under the constraints of the overall transmit power of each remote access unit (RAU), proportional fairness data rates, and bit error rates (BERs). Because of the nonconvex nature of the optimization problem, obtaining the optimal solution is extremely computationally complex. Therefore, we develop a low-complexity suboptimal algorithm, which separates subcarrier allocation and power allocation. For the low-complexity algorithm, we first allocate subcarriers by assuming equal power distribution. Then, by exploiting the properties of fractional programming, we transform the nonconvex optimization problem in fractional form into an equivalent optimization problem in subtractive form, which includes a tractable solution. Next, an optimal energy-efficient power-allocation algorithm is developed to maximize EE while maintaining proportional fairness. Through computer simulation, we demonstrate the effectiveness of the proposed low-complexity algorithm and illustrate the fundamental trade off between energy and spectral-efficient transmission designs.

Simultaneous mobile sink allocation in home environments with applications in mobile consumer robotics

This paper presents a novel mobile sink area allocation scheme for consumer based mobile robotic devices with a proven application to robotic vacuum cleaners. In the home or office environment, rooms are physically separated by walls and an automated robotic cleaner cannot make a decision about which room to move to and perform the cleaning task. Likewise, state of the art cleaning robots do not move to other rooms without direct human interference. In a smart home monitoring system, sensor nodes may be deployed to monitor each separate room. In this work, a quad tree based data gathering scheme is proposed whereby the mobile sink physically moves through every room and logically links all separated sub-networks together. The proposed scheme sequentially collects data from the monitoring environment and transmits the information back to a base station. According to the sensor nodes information, the base station can command a cleaning robot to move to a specific location in the home environment. The quad tree based data gathering scheme minimizes the data gathering tour length and time through the efficient allocation of data gathering areas. A calculated shortest path data gathering tour can efficiently be allocated to the robotic cleaner to complete the cleaning task within a minimum time period. Simulation results show that the proposed scheme can effectively allocate and control the cleaning area to the robot vacuum cleaner without any direct interference from the consumer. The performance of the proposed scheme is then validated with a set of practical sequential data gathering tours in a typical office/home environment.

What you see is what you want to see: motivationally relevant stimuli can interrupt current resource allocation

Arousing stimuli, either threat-related or pleasant, may be selected for priority at different stages within the processing stream. Here we examine the pattern of processing for non-task-relevant threatening (spiders: arousing to some) and pleasant stimuli (babies or chocolate: arousing to all) by recording the gaze of a spider Fearful and Non-fearful group while they performed a simple “follow the cross” task. There was no difference in first saccade latencies. Saccade trajectories showed a general hypervigilance for all stimuli in the Fearful group. Saccade landing positions corresponded to what each group would find arousing, such that the Fearful group deviated towards both types of images whereas the Non-fearful group deviated towards pleasant images. Secondary corrective saccade latencies away from threat-related stimuli were longer for the Fearful group (difficulty in disengaging) compared with the Non-fearful group. These results suggest that attentional biases towards arousing stimuli may occur at different processing stages.

A herald and his objects in exile: Roger Machado and his memorandum book, 1484-1485

A re-examination of the herald Roger Machado's extant memorandum book, which contains an inventory and mercantile accounts amongst its contents. It is argued that this little-studied source provides evidence for an otherwise undocumented period in Machado's life - when he fled into exile to join Henry Tudor.

Human resource allocation management in multiple projects using sociometric techniques

This article describes a new application of key psychological concepts in the area of Sociometry for the selection of workers within organizations in which projects are developed. The project manager can use a new procedure to determine which individuals should be chosen from a given pool of resources and how to combine them into one or several simultaneous groups/projects in order to assure the highest possible overall work efficiency from the standpoint of social interaction. The optimization process was carried out by means of matrix calculations performed using a computer or even manually, and based on a number of new ratios generated ad-hoc and composed on the basis of indices frequently used in Sociometry.

Seminar: sensory objects in progress

Researchers and Co-researchers present talks and demonstrations about the Sensory Objects project to 65 people on Tuesday 10th of June, the Seminar is part of Universities Week.

Interactive sensory objects for and by people with learning disabilities

This project engages people with learning disabilities to participate as co-researchers and explore museum interpretation through multisensory workshops using microcontrollers and sensors to enable alternative interactive visitor experiences in museums and heritage sites. This article describes how the project brings together artists, engineers, and experts in multimedia advocacy, as well as people with learning disabilities in the co-design of interactive multisensory objects that replicate or respond to objects of cultural significance in our national collections. Through a series of staged multi-sensory art and electronics workshops, people with learning disabilities explore how the different senses could be utilised to augment existing artefacts or create entirely new ones. The co-researchers employ multimedia advocacy tools to reflect on and to communicate their experiences and findings.

Sensory objects at the British Museum

The Sensory Objects project creates multisensory interactive artworks that respond to museum collections and generate alternative ideas for museum interpretation.

Seminar: sensory objects

Seminar exploring the Sensory Objects Project at the British Museum for 65 delegates.

Workshop: sensory objects

The Sensory Objects project was represented by co-researchers Judith Appiah and Tim Elson supported by Beverley Agard from the Tower Project, who co-presented with Nic and Kate at ENGAGE 2014 conference in Bristol.