... Lancet 370, 15601567. 3. Foresight (2007) Tackling Obesity: Future Choices. London: Governme... more ... Lancet 370, 15601567. 3. Foresight (2007) Tackling Obesity: Future Choices. London: Government Office for Science. 4. Balding J (2001) Food choices and weight control. In Young People in 2000, pp. 112 [J Balding, editor]. Exeter: Schools Health Education Unit. ...
Hybrid search heuristics are known to be valuable in generating better and/or faster solutions to... more Hybrid search heuristics are known to be valuable in generating better and/or faster solutions to computational hard search problems than evolutionary techniques in isolation. Inspired by the idea of nest building, we introduce a new hybrid approach to network planning that uses a nest builder to follow a given movement sequence and decide whether to place nesting material; this corresponds to visiting candidate base station sites and configuring transmission powers. A genetic algorithm then evolves better search patterns for subsequent generations to simulate learning. The goal of this paper is to investigate the usefulness of this notion during the bi-objective optimization of a wireless network to find the best site locations and starting powers for use in subsequent site dimensioning. The model, algorithms, test, and results are fully delineated with respect to two real-world network planning scenarios.
An electronic market platform usually requires buyers and sellers to exchange offers-to-buy and o... more An electronic market platform usually requires buyers and sellers to exchange offers-to-buy and offers-to-sell. The goal of this exchange is to reach an agreement on the suitability of closing transactions between buyers and sellers. In this paper we use multilateral and integrative e-negotiations to investigate our approach which attempts to find the best buyer-seller pairs, for an equal number of buyers and seller, using either matchmaking or a well-tested genetic algorithm: NSGA-II. The goal is to match as many buyers and sellers as closely as possible on five objectives (i.e., quality, quantity, price, delivery and payment) that vary randomly between a given range for buyers and are fixed for sellers. Experiments are performed and results are discussed for both approaches. The main finding is that there is a trade-off between solution quality and execution time: The genetic algorithm is capable of finding higher quality solutions than matchmaking when a suitable population size ...
Providing downlink wireless coverage is expensive and represents a dominant variable cost for mob... more Providing downlink wireless coverage is expensive and represents a dominant variable cost for mobile communication operators. It is vital that operators select base station locations so that efficiency is achieved, with high coverage relative to total cost of the selected operational ...
Trauma exposure and posttraumatic stress disorder (PTSD) are common among individuals with a ment... more Trauma exposure and posttraumatic stress disorder (PTSD) are common among individuals with a mental disorder, but symptoms often go undetected and untreated. The aim of this study was to determine the prevalence of PTSD among a large sample of adults with psychiatric diagnoses and to establish factors associated with symptoms going undetected. Participants were 1,946 adults recruited by the National Centre for Mental Health. Structured interviews and validated self-report questionnaires were used to ascertain clinical and demographic information for analysis. The prevalence of participants screening positive for PTSD that had not been detected by clinical services was 13.9% [12.4-15.5%, 95% confidence interval]). Factors associated with undetected PTSD were female gender, younger age of first contact with psychiatric services, and lower household income. Especially, poor rates of detection were observed after traumatic events, such as child abuse and sexual assault. Our findings dem...
To examine school-level relationships between deprivation and breakfast eating behaviours (breakf... more To examine school-level relationships between deprivation and breakfast eating behaviours (breakfast skipping and the healthfulness of foods consumed) in 9-11-year-old schoolchildren and to examine whether attitudes towards eating breakfast mediated these relationships. Cross-sectional survey. One hundred and eleven primary schools in Wales. Year 5 and 6 pupils within the 111 primary schools. Measures were completed by 4314 children. Analysis was conducted at the group (school) level, with each school representing one group. Deprivation was positively associated with breakfast skipping and consumption of 'unhealthy' items (i.e. sweet snacks, crisps) for breakfast. A significant negative association was found between deprivation and consumption of 'healthy' items (i.e. fruit, bread, cereal, milk). Deprivation was significantly inversely associated with attitudes towards eating breakfast. The relationships between deprivation and (1) breakfast skipping and (2) consumpt...
Ahstract-Providing downlink received signal strength in volves balancing trade-offs between servi... more Ahstract-Providing downlink received signal strength in volves balancing trade-offs between service coverage objectives and cost minimisation, while taking into account radio engineer ing constraints concerning interference, cell overlap for call han dover and traffic capacity. ...
... Lancet 370, 15601567. 3. Foresight (2007) Tackling Obesity: Future Choices. London: Governme... more ... Lancet 370, 15601567. 3. Foresight (2007) Tackling Obesity: Future Choices. London: Government Office for Science. 4. Balding J (2001) Food choices and weight control. In Young People in 2000, pp. 112 [J Balding, editor]. Exeter: Schools Health Education Unit. ...
Hybrid search heuristics are known to be valuable in generating better and/or faster solutions to... more Hybrid search heuristics are known to be valuable in generating better and/or faster solutions to computational hard search problems than evolutionary techniques in isolation. Inspired by the idea of nest building, we introduce a new hybrid approach to network planning that uses a nest builder to follow a given movement sequence and decide whether to place nesting material; this corresponds to visiting candidate base station sites and configuring transmission powers. A genetic algorithm then evolves better search patterns for subsequent generations to simulate learning. The goal of this paper is to investigate the usefulness of this notion during the bi-objective optimization of a wireless network to find the best site locations and starting powers for use in subsequent site dimensioning. The model, algorithms, test, and results are fully delineated with respect to two real-world network planning scenarios.
An electronic market platform usually requires buyers and sellers to exchange offers-to-buy and o... more An electronic market platform usually requires buyers and sellers to exchange offers-to-buy and offers-to-sell. The goal of this exchange is to reach an agreement on the suitability of closing transactions between buyers and sellers. In this paper we use multilateral and integrative e-negotiations to investigate our approach which attempts to find the best buyer-seller pairs, for an equal number of buyers and seller, using either matchmaking or a well-tested genetic algorithm: NSGA-II. The goal is to match as many buyers and sellers as closely as possible on five objectives (i.e., quality, quantity, price, delivery and payment) that vary randomly between a given range for buyers and are fixed for sellers. Experiments are performed and results are discussed for both approaches. The main finding is that there is a trade-off between solution quality and execution time: The genetic algorithm is capable of finding higher quality solutions than matchmaking when a suitable population size ...
Providing downlink wireless coverage is expensive and represents a dominant variable cost for mob... more Providing downlink wireless coverage is expensive and represents a dominant variable cost for mobile communication operators. It is vital that operators select base station locations so that efficiency is achieved, with high coverage relative to total cost of the selected operational ...
Trauma exposure and posttraumatic stress disorder (PTSD) are common among individuals with a ment... more Trauma exposure and posttraumatic stress disorder (PTSD) are common among individuals with a mental disorder, but symptoms often go undetected and untreated. The aim of this study was to determine the prevalence of PTSD among a large sample of adults with psychiatric diagnoses and to establish factors associated with symptoms going undetected. Participants were 1,946 adults recruited by the National Centre for Mental Health. Structured interviews and validated self-report questionnaires were used to ascertain clinical and demographic information for analysis. The prevalence of participants screening positive for PTSD that had not been detected by clinical services was 13.9% [12.4-15.5%, 95% confidence interval]). Factors associated with undetected PTSD were female gender, younger age of first contact with psychiatric services, and lower household income. Especially, poor rates of detection were observed after traumatic events, such as child abuse and sexual assault. Our findings dem...
To examine school-level relationships between deprivation and breakfast eating behaviours (breakf... more To examine school-level relationships between deprivation and breakfast eating behaviours (breakfast skipping and the healthfulness of foods consumed) in 9-11-year-old schoolchildren and to examine whether attitudes towards eating breakfast mediated these relationships. Cross-sectional survey. One hundred and eleven primary schools in Wales. Year 5 and 6 pupils within the 111 primary schools. Measures were completed by 4314 children. Analysis was conducted at the group (school) level, with each school representing one group. Deprivation was positively associated with breakfast skipping and consumption of 'unhealthy' items (i.e. sweet snacks, crisps) for breakfast. A significant negative association was found between deprivation and consumption of 'healthy' items (i.e. fruit, bread, cereal, milk). Deprivation was significantly inversely associated with attitudes towards eating breakfast. The relationships between deprivation and (1) breakfast skipping and (2) consumpt...
Ahstract-Providing downlink received signal strength in volves balancing trade-offs between servi... more Ahstract-Providing downlink received signal strength in volves balancing trade-offs between service coverage objectives and cost minimisation, while taking into account radio engineer ing constraints concerning interference, cell overlap for call han dover and traffic capacity. ...
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Papers by Lawrence Raisanen