<p> Software Architecture is a concept that arose during the last two decades as a consequence of the need for a structured design at an early stage. Software Architecture is defined as a pattern of interconnected components satisfying some structural rule. Software architectures are widely used in many types of systems; Multi-Agent Systems should not be an exception. Multi-Agent Systems have emerged as a design paradigm for large and distributed systems. They are composed of autonomous elements that work together in order to pursue a common goal. They are mostly used in Electronic Commerce, Human-Computer Interfaces, and so on.</p> <p> In this research, we investigate the state of the art of Software Architectures in the Multi-Agent Systems field, showing that, generally Multi-Agent Systems do no use the software architecture concept properly and, when they do, they do not show specific architectures for Multi-Agent Systems. The approach followed is based on the analysis of six case studies, which are implemented applications that have been published in some of the most important conferences in the area. Additionally we show that, based on the initial design of each case and existing architectural patterns, it is possible to impose a software architecture on each case.</p> <p> Furthermore, we analyze the way that the term "software architecture" is used in the Multi-Agent Systems literature, showing that, usually, it refers to abstract architectures proposed in standards and frameworks or to an initial design in a system. In addition we clarify related concepts, such as reference architecture, reference models, architectural patterns and design patterns. Finally, we do an exhaustive comparison of the case studies, which aims to highlight commonalities and differences. The objective of this comparison is to analyze if they share a similar architecture that can be reused in more cases and to show how specific properties of Multi-Agent Systems affect in the design of an architecture.</p> / Thesis / Master of Science (MSc)

A user-centered approach to interactive system development requires a way to represent the behavior of a user interacting with an interface. While a number of behavioral representation techniques exist, not all provide the capabilities necessary to support the interaction development process. The original goal of this research was to modify and extend the User Action Notation (UAN), a user- and task-centered behavioral representation technique. In order to facilitate and evaluate the improvement in the UAN, we developed and evaluated a taxonomic model of behavioral representation techniques. The development and evaluation of our model followed the epistemological cycle of observation, theorization, and evaluation. The model provides a framework for discussing, analyzing, extending, and comparing existing behavioral representation techniques, as well as being a springboard for developing and evaluating new techniques. / Ph. D.

see document / Master of Science

This thesis discusses the use of genetic algorithms as a global search technique to solve three optimization problems: a sixth-order polynomial problem, a single-degree-of-freedom spring-mass-damper (SDOF SMD) system problem, and a loading bridge regulator problem. Genetic algorithms are iterative global search techniques based on the principles of natural selection and population genetics. The theory, design and implementation of the algorithm is discussed in detail. The Simple Genetic Algorithm (SGA) is presented to solve a sixth-order polynomial optimization problem. Results from two traditional numerical techniques will be compared with the SGA results as well as the analytical calculus solution. In addition, the effect of different parametric sizes of the genetic operators are investigated. In the second problem, genetic algorithms are used to design a two-state feedback optimal gain set for a SDOF SMD model with a given initial condition. An improved selection scheme called the stochastic remainder selection without replacement is introduced. An improved GA-based (IGA) feedback controller is designed to control the system. Lastly, a regulator control problem is presented using advanced genetic algorithms (AGA). Two-point crossover and inversion operators are employed. A loading bridge is chosen as the control model. An advanced GA-based full-state feedback controller is designed to control the loading bridge with the given reference input voltage. The conclusions show that SGA is more robust than traditional numerical techniques to solve multi-modal functions. Among the three GA approaches considered, AGA is the most robust one for the design of adaptive feedback controllers. / Master of Science

For the implementation of the NASA EOS testbed programmable operations, a control/data acquisition system has been designed, implemented, and tested. The work is focused mainly on the hardware design/build of the custom interface board and software development for real-time control and data acquisition of the testbed. Also, an application program was designed to control, collect, and display the data and parameters of the testbed elements, and troubleshoot the hardware. An algorithm was chosen and applied to the battery simulator control after computer simulations. The final experiment results were obtained successfully, which proved the design to be correct, as the testbed could be operated under computer control. / Master of Science

The user interface development process occurs in a behavioral domain and in a constructional domain. The development process in the behavioral domain focuses on the "look and feel" of the user interface and its behavior in response to user actions. The development process in the constructional domain focuses on developing software to implement the user interface. Although one may attempt to design a user interface from a constructional view, it is important to concentrate design efforts in the behavioral domain to improve software usability. User Action Notation (UAN) is a useful technique for representing user interaction designs in the behavioral domain. Primary abstractions in UAN-expressed designs are user tasks. Information about interface objects is encapsulated in user task descriptions and scenarios. Primary abstractions in a GUI such as Motif™ are interface objects. Motif implements objects' behavior and appearance using system functions that are encapsulated within pre-defined object classes. Therefore, user interaction developers and software developers must communicate well to translate UAN-expressed interaction designs into Motif-based software designs. Translation is not trivial since it is a translation between two significantly different domains. This thesis contributes to understanding of the user interface development process by developing a foundation to assist translation of user interaction designs into Motif-based software designs. This thesis develops the foundation as follows: 1. Adapt UAN for use with Motif. 2. Summarize Motif concepts about objects and object relationships. 3. Develop new approaches for discussing objects and object relationships. 4. Develop a partial translation guide containing VAN descriptions of selected Motif abstractions. / Master of Science

The explosive growth in networked systems and applications and the increase in device capabilities (as evidenced by the availability of inexpensive multimedia devices) enable novel complex distributed applications, including video conferencing, on-demand computing services, and virtual environments. These applications' need for high performance, real-time, or reliability requires the provision of Quality of Service (QoS) guarantees along the path of information exchange between two or more communicating systems. Execution environments that are prone to dynamic variability and uncertainty make QoS provision a challenging task, e.g., changes in user behavior, resource requirements, resource availabilities, or system failures are difficult or even impossible to predict. Further, with the coexistence of multiple adaptation techniques and resource management mechanisms, it becomes increasingly important to provide an integrated or cooperative approach to distributed QoS management. This work's goals are the provision of system-level tools needed for the efficient integration of multiple adaptation approaches available at different layers of a system (e.g., application-level, operating system, or network) and the use of these tools such that distributed QoS management is performed efficiently with predictable results. These goals are addressed constructively and experimentally with the Q-Fabric architecture, which provides the required system-level mechanisms to efficiently integrate multiple adaptation techniques. The foundation of this integration is the event-based communication implemented by it, realizing a loosely-coupled group communication approach frequently found in multi-peer applications. Experimental evaluations are performed in the context of a mobile multimedia application, where the focus is directed toward efficient energy consumption on battery-operated devices. Here, integration is particularly important to prevent multiple energy management techniques found on modern mobile devices to negate the energy savings of each other.

We have investigated, in various multiple senses, the “capacity” of several models of erasure networks. The defining characteristic of a memoryless erasure network is that each channel between any two nodes is an independent erasure channel. The models that we explore differ in the absence or presence of interference at either the transmitters, the receivers, or both; and in the availability of feedback at the transmitters. The crux of this work involves the investigation and analysis of several different performance measures for these networks: traditional information capacity (including multicast capacity and feeback capacity), secrecy capacity, and transport capacity. / text

With the world amidst globalization and economic flux affecting business, industry, and communities the need to work together becomes increasingly important. Higher education serves an important role in developing the individual teaming capabilities of the workforce. This environment is the time and place - opportunity for student personnel to develop these capabilities. This multiple case study utilized the analysis phase (learner, setting and job) of an instructional design model to analyze learner characteristics, the higher education environment/undergraduate experience, and the job/skills associated with individual teamwork knowledge, skills, and abilities of students from a senior cohort of the TRiO - SSS Project at a public student-centered research institution. The results yielded themes to promote the development of target populations individual teamwork KSAs which should increase their readiness to meet the teaming demands of today's employers. With an engaging undergraduate experience, inclusive of interaction with faculty members and collaborative learning with their peers, structured opportunities to practice individual teamwork KSAs in a work setting or internship, these underrepresented students may be an asset that is needed to meet the global workforce needs and fill civic capacities in their home communities.

The purpose of this project is to develop a website that helps left handed students, their parents, and teachers to help left-handers, whether they are left-or-right-brain dominant, succeed. This website will be a tool to get to know their children and students better. The project consists of a paper and a website to educate about left-handed people.