Agent-based hybrid framework for decision making on complex problems

Electronic commerce and the Internet have created demand for automated systems that can make complex decisions utilizing information from multiple sources. Because the information is uncertain, dynamic, distributed, and heterogeneous in nature, these systems require a great diversity of intelligent techniques including expert systems, fuzzy logic, neural networks, and genetic algorithms. However, in complex decision making, many different components or sub-tasks are involved, each of which requires different types of processing. Thus multiple such techniques are required resulting in systems called hybrid intelligent systems. That is, hybrid solutions are crucial for complex problem solving and decision making. There is a growing demand for these systems in many areas including financial investment planning, engineering design, medical diagnosis, and cognitive simulation. However, the design and development of these systems is difficult because they have a large number of parts or components that have many interactions. From a multi-agent perspective, agents in multi-agent systems (MAS) are autonomous and can engage in flexible, high-level interactions. MASs are good at complex, dynamic interactions. Thus a multi-agent perspective is suitable for modeling, design, and construction of hybrid intelligent systems. The aim of this thesis is to develop an agent-based framework for constructing hybrid intelligent systems which are mainly used for complex problem solving and decision making. Existing software development techniques (typically, object-oriented) are inadequate for modeling agent-based hybrid intelligent systems. There is a fundamental mismatch between the concepts used by object-oriented developers and the agent-oriented view. Although there are some agent-oriented methodologies such as the Gaia methodology, there is still no specifically tailored methodology available for analyzing and designing agent-based hybrid intelligent systems. To this end, a methodology is proposed, which is specifically tailored to the analysis and design of agent-based hybrid intelligent systems. The methodology consists of six models - role model, interaction model, agent model, skill model, knowledge model, and organizational model. This methodology differs from other agent-oriented methodologies in its skill and knowledge models. As good decisions and problem solutions are mainly based on adequate information, rich knowledge, and appropriate skills to use knowledge and information, these two models are of paramount importance in modeling complex problem solving and decision making. Follow the methodology, an agent-based framework for hybrid intelligent system construction used in complex problem solving and decision making was developed. The framework has several crucial characteristics that differentiate this research from others. Four important issues relating to the framework are also investigated. These cover the building of an ontology for financial investment, matchmaking in middle agents, reasoning in problem solving and decision making, and decision aggregation in MASs. The thesis demonstrates how to build a domain-specific ontology and how to access it in a MAS by building a financial ontology. It is argued that the practical performance of service provider agents has a significant impact on the matchmaking outcomes of middle agents. It is proposed to consider service provider agents' track records in matchmaking. A way to provide initial values for the track records of service provider agents is also suggested. The concept of ‘reasoning with multimedia information’ is introduced, and reasoning with still image information using symbolic projection theory is proposed. How to choose suitable aggregation operations is demonstrated through financial investment application and three approaches are proposed - the stationary agent approach, the token-passing approach, and the mobile agent approach to implementing decision aggregation in MASs. Based on the framework, a prototype was built and applied to financial investment planning. This prototype consists of one serving agent, one interface agent, one decision aggregation agent, one planning agent, four decision making agents, and five service provider agents. Experiments were conducted on the prototype. The experimental results show the framework is flexible, robust, and fully workable. All agents derived from the methodology exhibit their behaviors correctly as specified.

Autonomous underwater vehicles in a hazardous non-deterministic environment

This research investigated the cooperation of multi underwater robots to perform a task. This combined engineering design, electronics and consensus control to create systems capable of achieving the task. Challenges such as underwater radio communications were researched and a simulation framework was created and tested on virtual and real systems.

Using the psychrometric chart in building measurements

This paper centres around the presentation of multiple measured results on a psychrometric chart. The psychrometric chart was programmed in Microsoft Office Excel to accommodate measured results. It was written because existing programs appear not to cater for the researcher wishing to enter results electronically onto the chart. Furthermore, many existing charts are complex and cluttered displaying up to ten attributes, being intended for engineering design, whereas presenting the behaviour of living and working environments is focused on wet and dry bulb temperature and relative humidity. As well as results, users would also like to specify and adjust the ‘comfort zone’ (a shaded area on the chart) for different ‘adaptive’ or ‘seasonal’ conditions. The comfort zone is bounded by lines of constant heat loss from the skin, relative humidity and wet-bulb temperature. The paper presents various applications of the psychrometric chart for the analysis and reporting of research and discusses the programming of Microsoft Office Excel to generate the chart and display user data.

Effect of strain ageing on the mechanical properties of partially damaged structural mild steel

ABSTRACT
This paper addresses the strain ageing effects on the mechanical properties of the partially damaged structural mild steel. Since repairing partly damaged structures may not occur immediately, the strain ageing effect can significantly influence the structural behaviour. The changes due to this effect have not so far been considered in the civil engineering design guidelines. In order to investigate strain ageing effects, two-stage experimental tests are carried out on the mild-steel specimens. In the first stage, partial damage is made using quasi-static loading. During the second stage, the strength and ductility of the specimens are examined after 2 and 7 days ‘ageing’ at room temperature and the results are compared with the corresponding no-age samples. The microstructure of the specimens is examined using scanning electron microscopy (SEM). To illustrate the effect of strain ageing on the global behaviour of steel structures, a numerical example is provided in which strain ageing impacts on loading capacity and deflection of a steel beam. Finally, the stress–strain relation of partially damaged mild-steel material incorporating strain ageing effects is expressed by calibrating the parameters of Ramberg–Osgood model.

Microstructure and mechanical properties of wrought and additive manufactured Ti-6Al-4V cylindrical bars

Titanium alloys are widely used in various engineering design application due to its superior material properties. The traditional manufacturing of titanium products is always difficult, time consuming, high material wastage and manufacturing costs. Selective laser melting (SLM), an additive manufacturing technology has widely gained attention due to its capability to produce near net shape components with less production time. In this technical paper,microstructure,chemical composition,tensile properties and hardness are studied for the wrought and additive manufactured SLM cylindrical bar. Microstructure,mechanical properties and hardness were studied in both the longitudinal and transverse directions of the bar to study the effect of orientation. It was found that additive manufactured bar have higher yield strength, ultimate tensile strength and hardness than the wrought bar. For both conventional and SLM test samples, the yield strength, ultimate tensile strength and hardness was found to be high in the transverse direction. The difference in the properties can be attributed to the difference in microstructure as a result of processing conditions. The tensile fracture area was quantified by careful examination of the fracture surfaces in the scanning electron microscope.

A taxonomy and mapping of computer-based critiquing tools

Critics have emerged in recent times as a specific tool feature to support users in computer-mediated tasks. These computer-supported critics provide proactive guidelines or suggestions for improvement to designs, code, and other digital artifacts. The concept of a critic has been adopted in various domains, including medical, programming, software engineering, design sketching, and others. Critics have been shown to be an effective mechanism for providing feedback to users. We propose a new critic taxonomy based on extensive review of the critic literature. The groups and elements of our critic taxonomy are presented and explained collectively with examples, including the mapping of 13 existing critic tools, predominantly for software engineering and programming education tasks to the taxonomy. We believe this critic taxonomy will assist others in identifying, categorizing, developing, and deploying computer-supported critics in a range of domains.

Subsídios para o projeto de estruturas sismo resistentes

Through this research is detailed the Brazilian seismic code focused on concrete projects design related to seismic engineering. At the beginning of the research is debated the fundaments of the seismic effects, the influence factors to the development of seismic effects and also relates the main data registration happened in Brazil. The second step is study the Brazilian seismic code explaining all the concepts related to it and does a compilation to the most important international seismic code. At this research is developed the designing of a building submitted to horizontal equivalent seismic forces and the modal process based on the answer spectrum based on the brazilin seismic code. It was also developed the design of a commercial building submitted to seismic loads based on the Brazilian code answer spectrum and compared to the same building submitted to wind loads.The research also focus on projects conception and detailing of seismic engineering Project design. At the study of seismic engineering it was concluded that seismic effects require special focus on concrete structures design, proving that is the essential consider the seismic effects

Production of active recombinant eIF5A: reconstitution in E.coli of eukaryotic hypusine modification of eIF5A by its coexpression with modifying enzymes

Eukaryotic translation initiation factor 5A (eIF5A) is the only cellular protein that contains the polyamine-modified lysine, hypusine [N(epsilon)-(4-amino-2-hydroxybutyl)lysine]. Hypusine occurs only in eukaryotes and certain archaea, but not in eubacteria. It is formed post-translationally by two consecutive enzymatic reactions catalyzed by deoxyhypusine synthase (DHS) and deoxyhypusine hydroxylase (DOHH). Hypusine modification is essential for the activity of eIF5A and for eukaryotic cell proliferation. eIF5A binds to the ribosome and stimulates translation in a hypusine-dependent manner, but its mode of action in translation is not well understood. Since quantities of highly pure hypusine-modified eIF5A is desired for structural studies as well as for determination of its binding sites on the ribosome, we have used a polycistronic vector, pST39, to express eIF5A alone, or to co-express human eIF5A-1 with DHS or with both DHS and DOHH in Escherichia coli cells, to engineer recombinant proteins, unmodified eIF5A, deoxyhypusine- or hypusine-modified eIF5A. We have accomplished production of three different forms of recombinant eIF5A in high quantity and purity. The recombinant hypusine-modified eIF5A was as active in methionyl-puromycin synthesis as the native, eIF5A (hypusine form) purified from mammalian tissue. The recombinant eIF5A proteins will be useful tools in future structure/function and the mechanism studies in translation.

Validation of a mutant of the pore-forming toxin sticholysin-I for the construction of proteinase-activated immunotoxins

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

The influence of the region between residues 220 and 344 and beyond in Phrixotrix railroad worm luciferases green and red bioluminescence

To find the regions having a major influence on the bioluminescence spectra of railroad worm luciferases, we constructed new chimeric luciferases switching the fragments from residues 1-219 and from 220-545 between Phrixotrix viviani (PxvGR; λmax = 548 nm) green light-emitting luciferase and Phrixothrix hirtus (PxhRE; λmax = 623 nm) red light-emitting luciferases. The emission spectrum (λmax = 571 nm) and KM for luciferin in the chimera PxRE220GR (1-219, PxhRE; 220-545, PxvGR) suggested that the region above residue 220 of PxvGR had a major effect on the active site. However, switching the sequence between the residues 226-344 from PxvGR luciferase into PxhRE (PxREGRRE) luciferase resulted in red light emission (λmax = 603 nm), indicating that the region 220-344 by itself does not determine the emission spectrum. Furthermore, the sequence before residue 220 of the green-emitting luciferase is incompatible for light emission with the sequence above residue 220 of PxhRE. These results suggest that the fragments before and after residue 220, which correspond to distinct subdomains, may fold differently in the green- and red-emitting luciferases, affecting the active site conformation.

Detecção e localização de danos em materiais compósitos aplicado em aeronaves utilizando redes neurais artificiais

Pós-graduação em Engenharia Mecânica - FEIS

Production of active recombinant eIF5A: reconstitution in E. coli of eukaryotic hypusine modification of eIF5A by its coexpression with modifying enzymes

Eukaryotic translation initiation factor 5A (eIF5A) is the only cellular protein that contains the polyamine-modified lysine, hypusine [Nε-(4-amino-2-hydroxybutyl)lysine]. Hypusine occurs only in eukaryotes and certain archaea, but not in eubacteria. It is formed post-translationally by two consecutive enzymatic reactions catalyzed by deoxyhypusine synthase (DHS) and deoxyhypusine hydroxylase (DOHH). Hypusine modification is essential for the activity of eIF5A and for eukaryotic cell proliferation. eIF5A binds to the ribosome and stimulates translation in a hypusine-dependent manner, but its mode of action in translation is not well understood. Since quantities of highly pure hypusine-modified eIF5A is desired for structural studies as well as for determination of its binding sites on the ribosome, we have used a polycistronic vector, pST39, to express eIF5A alone, or to co-express human eIF5A-1 with DHS or with both DHS and DOHH in Escherichia coli cells, to engineer recombinant proteins, unmodified eIF5A, deoxyhypusine- or hypusine-modified eIF5A. We have accomplished production of three different forms of recombinant eIF5A in high quantity and purity. The recombinant hypusine-modified eIF5A was as active in methionyl-puromycin synthesis as the native, eIF5A (hypusine form) purified from mammalian tissue. The recombinant eIF5A proteins will be useful tools in future structure/function and the mechanism studies in translation.

Interpretação racional do ensaio DPL

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

A new method for decision making in multi-objective optimization problems

Many engineering sectors are challenged by multi-objective optimization problems. Even if the idea behind these problems is simple and well established, the implementation of any procedure to solve them is not a trivial task. The use of evolutionary algorithms to find candidate solutions is widespread. Usually they supply a discrete picture of the non-dominated solutions, a Pareto set. Although it is very interesting to know the non-dominated solutions, an additional criterion is needed to select one solution to be deployed. To better support the design process, this paper presents a new method of solving non-linear multi-objective optimization problems by adding a control function that will guide the optimization process over the Pareto set that does not need to be found explicitly. The proposed methodology differs from the classical methods that combine the objective functions in a single scale, and is based on a unique run of non-linear single-objective optimizers.

Development of parallelizable flood inundation models for large scale analysis

Flood disasters are a major cause of fatalities and economic losses, and several studies indicate that global flood risk is currently increasing. In order to reduce and mitigate the impact of river flood disasters, the current trend is to integrate existing structural defences with non structural measures. This calls for a wider application of advanced hydraulic models for flood hazard and risk mapping, engineering design, and flood forecasting systems. Within this framework, two different hydraulic models for large scale analysis of flood events have been developed. The two models, named CA2D and IFD-GGA, adopt an integrated approach based on the diffusive shallow water equations and a simplified finite volume scheme. The models are also designed for massive code parallelization, which has a key importance in reducing run times in large scale and high-detail applications. The two models were first applied to several numerical cases, to test the reliability and accuracy of different model versions. Then, the most effective versions were applied to different real flood events and flood scenarios. The IFD-GGA model showed serious problems that prevented further applications. On the contrary, the CA2D model proved to be fast and robust, and able to reproduce 1D and 2D flow processes in terms of water depth and velocity. In most applications the accuracy of model results was good and adequate to large scale analysis. Where complex flow processes occurred local errors were observed, due to the model approximations. However, they did not compromise the correct representation of overall flow processes. In conclusion, the CA model can be a valuable tool for the simulation of a wide range of flood event types, including lowland and flash flood events.