Papers by Babak Mahdavi Ardestani
The Lancet Regional Health - Americas
Computers, Environment and Urban Systems, 2018
AIDS and Behavior, 2020
Interventions that effective strategies for engaging utilize the influence of peer change agents ... more Interventions that effective strategies for engaging utilize the influence of peer change agents (PCAs) have been shown to be key populations in HIV prevention. To date, little is known about the characteristics of PCAs associated with their effectiveness. Drawing on data from a peer leader PrEP intervention for young Black men who have sex with men (YBMSM) (N=423), we evaluated the effects of experiential (i.e., living with HIV, PrEP awareness, PrEP use), psychographic (i.e., self-perceived leadership, innovativeness), and network (i.e., degree centrality, eigenvector centrality, and brokerage) characteristics on three effectiveness outcomes: 1) recruiting peers into the study; 2) completing "booster" sessions; and 3) linking peers to PrEP care. For each outcome, multivariable regressions were performed. On average, PCAs recruited 0.89 peers, completed 1.99 boosters, and had 1.33 network peers linked to PrEP care.
AIDS and Behavior, 2020
This analysis examines how sex behaviors are influenced by a sex partner's network bridging posit... more This analysis examines how sex behaviors are influenced by a sex partner's network bridging position and the residential proximity between the two. The study sample consisted of 437 young black men who have sex with men (YBMSM) in Chicago and their sex partners (2013-2014). Dyadic analyses that clustered on individuals using generalized estimating equations (n=1095 relationships) were conducted to assess the associations between different HIV-related sexual behaviors and the network position of and residential proximity to a partner. The odds of group sex was higher with partners who had high network bridging, regardless of how close they lived to one another. The odds of transactional sex was higher with partners who had high network bridging and lived in a different region of the city. Sex behaviors associated with an increased risk of HIV transmission were associated with the network structural position of and residential proximity to partners among YBMSM.
IET Renewable Power Generation, 2013
The ability to influence electricity demand from domestic and small business consumers so that it... more The ability to influence electricity demand from domestic and small business consumers so that it can be matched to intermittent renewable generation and distribution network constraints is a key capability of a smart grid. This involves signalling to consumers to indicate when electricity use is desirable or undesirable. However simply signalling a time dependent price does not always achieve the required demand response and can result in unstable system behaviour. We propose a demand response scheme in which an aggregator mediates between the consumer and the market and provides a signal to a "smart home" control unit that manages the consumer's appliances using a novel method for reconciliation of the consumer's needs and preferences with the incentives supplied by the signal. This method involves random allocation of demand within timeslots acceptable to the consumer with a bias depending on the signal provided. By simulating a population of domestic consumers using heat pumps and electric vehicles with properties consistent with UK national statistics, we show the method allows total demand to be predicted and shaped in a way that can simultaneously match renewable generation and satisfy network constraints, leading to benefits from reduced use of peaking plant and avoided network reinforcement.
Data memory (heap) management is a particularly important feature of the Java programming environ... more Data memory (heap) management is a particularly important feature of the Java programming environment. The visualization of memory location in form of hot spots can help to see how the data cache is used during the execution of a program. The behavior of ...
8th Symposium on Multidisciplinary Analysis and Optimization, 2000
ABSTRACT The Complex Adaptive Systems, Cognitive Agents and Distributed Energy (CASCADE) project ... more ABSTRACT The Complex Adaptive Systems, Cognitive Agents and Distributed Energy (CASCADE) project is developing a framework based on Agent Based Modelling (ABM). The CASCADE Framework can be used both to gain policy and industry relevant insights into the smart grid concept itself and as a platform to design and test distributed ICT solutions for smart grid based business entities. ABM is used to capture the behaviors of different social, economic and technical actors, which may be defined at various levels of abstraction. It is applied to understanding their interactions and can be adapted to include learning processes and emergent patterns. CASCADE models ‘prosumer’ agents (i.e., producers and/or consumers of energy) and ‘aggregator’ agents (e.g., traders of energy in both wholesale and retail markets) at various scales, from large generators and Energy Service Companies down to individual people and devices. The CASCADE Framework is formed of three main subdivisions that link models of electricity supply and demand, the electricity market and power fl ow. It can also model the variability of renewable energy generation caused by the weather, which is an important issue for grid balancing and the profitability of energy suppliers. The development of CASCADE has already yielded some interesting early findings, demonstrating that it is possible for a mediating agent (aggregator) to achieve stable demand flattening across groups of domestic households fitted with smart energy control and communication devices, where direct wholesale price signals had previously been found to produce characteristic complex system instability. In another example, it has demonstrated how large changes in supply mix can be caused even by small changes in demand profile. Ongoing and planned refinements to the Framework will support investigation of demand response at various scales, the integration of the power sector with transport and heat sectors, novel technology adoption and diffusion work, evolution of new smart grid business models, and complex power grid engineering and market interactions.
The impact of residential segregation on the dynamics of spatial, social and economic spheres of ... more The impact of residential segregation on the dynamics of spatial, social and economic spheres of society is a topic of great interest in geography, sociology and economics. Residential segregation and its spatial separation effects have been acknowledged as having significant impacts on education, healthcare, business as well as social network and social/ urban structures. The complexity and multidimensional nature of the residential segregation phenomenon and the centrality of the individual based decision making process made this topic an ideal case for investigation using a micro/ individual based simulation modelling approach. An example of such an approach is agent?based modelling (ABM) as theorised by Thomas Schelling. However, most Schelling?type models are often too simple and small. This lack of sophistication and ‘small?village’ syndrome remain though among the major weak points of existing models generally. More importantly, the lack of empirical support for informing and...
Mathematical Biosciences and Engineering
22nd International Conference and Exhibition on Electricity Distribution (CIRED 2013), 2013
Emergence: Complexity & Organization
Proceedings of the Sixth International Conference on Computer Supported Cooperative Work in Design (IEEE Cat. No.01EX472), 2001
This work has its interests in the relation between the generation mix within a power system and ... more This work has its interests in the relation between the generation mix within a power system and the elasticity of demand based on the prices emerging from the short term electricity market. The paper starts by describing a new agent-based modelling framework that involves electricity producers, consumers and suppliers as agents participating in a market environment. The framework allows for investigating the effect of demand elasticities on bidding of generators in the short term market and its influence on their revenue in the long term. We focus on the increasingly important issue of renewable technology such as wind generation and the volatility it brings into the electricity market. Specifically we investigate three scenarios with varying mix of generating technologies such as coal, gas and wind turbines and measure the aggregate demand response to signals such as the System Buy Prices (SBP) emerging out of the balancing market.
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Papers by Babak Mahdavi Ardestani