A new method for predicting the uncertainty in a nonlinear dynamical system is developed and analyzed in the context of uncertainty evolution for resident space objects (RSOs) in the near-geosynchronous orbit regime under the influence of central body gravitational acceleration, third body perturbations, and attitude-dependent solar radiation pressure (SRP) accelerations and torques. The new method, termed the splitting Gaussian mixture unscented Kalman filter (SGMUKF), exploits properties of the differential entropy or Renyi entropy for a linearized dynamical system to determine when a higher-order prediction of uncertainty reaches a level of disagreement with a first-order prediction, and then applies a multivariate Gaussian splitting algorithm to reduce the impact of induced nonlinearity. In order to address the relative accuracy of the new method with respect to the more traditional approaches of the extended Kalman filter (EKF) and unscented Kalman filter (UKF), several concepts regarding the comparison of probability density functions (pdfs) are introduced and utilized in the analysis. The research also describes high-fidelity modeling of the nonlinear dynamical system which drives the motion of an RSO, and includes models for evaluation of the central body gravitational acceleration, the gravitational acceleration due to other celestial bodies, and attitude-dependent SRP accelerations and torques when employing a macro plate model of an RSO. Furthermore, a high-fidelity model of the measurement of the line-of-sight of a spacecraft from a ground station is presented, which applies light-time and stellar aberration corrections, and accounts for observer and target lighting conditions, as well as for the sensor field of view. The developed algorithms are applied to the problem of forward predicting the time evolution of the region of uncertainty for RSO tracking, and uncertainty rectification via the fusion of incoming measurement data with prior knowledge. It is demonstrated that the SGMUKF method is significantly better able to forward predict the region of uncertainty and is subsequently better able to utilize new measurement data. / text

Organizational environment (broadly conceptualized) has been shown to have an important influence on job choice (Chapman, Uggerslev, Carroll, Piasentin & Jones, 2005). Controversy exists, however, regarding how to operationalize organizational environment in a way that is both useful and parsimonious. Consistent with the perspective that situational strength meets these criteria (Meyer & Dalal, 2009), the present study found that participants were attracted to hypothetical organizations that were strong with respect to clarity, consistency, and consequences, but weak with respect to constraints. Further, individual differences in various psychological needs were shown to influence the strength of the relationship between situational strength and organizational attraction; for example, those with a high need for achievement were particularly attracted to organizations that were high with respect to consequences. These results not only contribute to the job choice literature, but also suggest that situational strength is more than just a moderator of personality-outcome relationships – it is an important psychological construct in and of itself, with its own nomological network that is worthy of continued research attention.

This thesis explores how Natural User Interface (NUI) interaction and Multiple Display Technology (MDT) can be applied to an existing Freight Management System (FMS), to improve the command and control interface of the dispatch operators. Situational Awareness (SA) and Task Efficiency (TE) are identified as being the main requirements for dispatchers. Based on studies that have been performed on SA and TE in other time critical occupations such as Emergency Medical Dispatch (EMD) and Air Traffic Control (ATC), a substitute dispatch display system was designed with focus on courier driver and freight management systems and monitoring. This system aims to alleviate cognitive overheads without disrupting the flow of the existing CFMS by providing extended screen area matched with a natural input mechanism for command and control functionality. This Master’s thesis investigates which of commercial state-of-the-art interface tools is best to use in a wide Field-of-View (FOV) multiple screen display and to dicern if there is any practical impact that a proposed NUI system will have to courier dispatching. To assess the efficacy of such a hypothetical system the author has developed an experimental prototype that combines a set of three monitors in a Multi-Monitor System to create the overall display system, accompanied with two traditional and two advanced NUI direct and indirect interaction techniques (mouse, trackpad, touch screen and gesture controller). Experiments using the prototype were conducted to determine the optimum configuration for control/display interface based upon task effectiveness, bandwidth and overall user desirability of these methods in supporting behavioural requirements of dispatch workstation task handling. The author use the well-studied and robust Fitts' Law for measuring and analysing user behaviour with NUIs. Evaluation of the prototype system finds that the multi-touch system paired with the multi-monitor system was the most responsive of the interaction techniques, direct or indirect. Based on these findings, employing such an interaction system is a viable option for deployment in FMS's. However for optimal efficiency, the firmware that supports the interactivity dynamics should be re-designed so it is optimized to touch interaction. This will allow the multi-touch system to be used effectively as an affordance technology. Although the gesture interaction approach has a lot of potential as an alternative NUI device, the performance of gesture input in this experimental setting had the worst performance of all conditions. This finding was largely a result of the interface device limitation within the wide FOV display range of the multi-monitor system. Further design improvements and experimentation are proposed to alleviate this problem for the gesture tracking and for the touchscreen modalities of interaction.

Software practitioners make technical and business decisions based on the understanding they have of their software systems. This understanding is grounded in their own experiences, but can be augmented by studying various kinds of development artifacts, including source code, bug reports, version control meta-data, test cases, usage logs, etc. Unfortunately, the information contained in these artifacts is typically not organized in the way that is immediately useful to developers’ everyday decision making needs. To handle the large volumes of data, many practitioners and researchers have turned to analytics — that is, the use of analysis, data, and systematic reasoning for making decisions. The thesis of this dissertation is that by employing software analytics to various development tasks and activities, we can provide software practitioners better insights into their processes, systems, products, and users, to help them make more informed data-driven decisions. While quantitative analytics can help project managers understand the big picture of their systems, plan for its future, and monitor trends, qualitative analytics can enable developers to perform their daily tasks and activities more quickly by helping them better manage high volumes of information. To support this thesis, we provide three different examples of employing software analytics. First, we show how analysis of real-world usage data can be used to assess user dynamic behaviour and adoption trends of a software system by revealing valuable information on how software systems are used in practice. Second, we have created a lifecycle model that synthesizes knowledge from software development artifacts, such as reported issues, source code, discussions, community contributions, etc. Lifecycle models capture the dynamic nature of how various development artifacts change over time in an annotated graphical form that can be easily understood and communicated. We demonstrate how lifecycle models can be generated and present industrial case studies where we apply these models to assess the code review process of three different projects. Third, we present a developer-centric approach to issue tracking that aims to reduce information overload and improve developers’ situational awareness. Our approach is motivated by a grounded theory study of developer interviews, which suggests that customized views of a project’s repositories that are tailored to developer-specific tasks can help developers better track their progress and understand the surrounding technical context of their working environments. We have created a model of the kinds of information elements that developers feel are essential in completing their daily tasks, and from this model we have developed a prototype tool organized around developer-specific customized dashboards. The results of these three studies show that software analytics can inform evidence-based decisions related to user adoption of a software project, code review processes, and improved developers’ awareness on their daily tasks and activities.

Sett utifrån ett historiskt perspektiv har utvecklingen av soldatens utrustning skett relativt långsamt. Dock har utvecklingen under det senaste decenniet gått fort framåt. I början på 2000-talet konfronterades flera länder av behovet av att utveckla soldaten och dennes personliga utrustning. Därför startade många länder egna framtida soldatsystemsprojekt. Tillgången till ett C4I-system är något som alla framtida soldatsystemsprojekt har gemensamt. Ett av C4I-systemets syfte är att underlätta för soldatens lägesuppfattning om egen position, egen enhets position och motståndarens position, samt den omgivande terrängen.Arbetets syfte är att ta reda på den militära nyttan av ett C4I-system vid bevakningstjänst. Två slutsatser som arbetet visar är att C4I-systemet bidrar till att öka soldatens förmåga för lägesuppfattning och orientering i terrängen. Tillgången till en digitalkarta underlättar orientering vid svåra förhållanden som i okänd terräng, nedsatt sikt och mörker. Den ökade lägesuppfattningsförmågan ger soldaten möjlighet att kunna skapa sig en överblick över och förståelse om den aktuella situationen, vilket leder till ökad effektivitet vid bevakningstjänst. / Seen from a historical perspective, the development of soldiers’ equipment has been relatively slow. However, developments this past decade have been faster. In the early 2000s several countries needed to develop soldiers’ personal equipment. Therefore, several countries have launched their own future soldier system project. The availability of a C4I system is something that all soldier modernization programmes have in common. One of the purposes of the C4I system is to provide the soldier situational awareness of his own position, the location of enemy and friendly forces, and the surrounding terrain. This study aims to investigate the military benefits of a C41 system for guard duty. Two conclusions of this study show that the C4I system helps enhance the soldier's situational awareness and orientation in the terrain. Access to a digital map facilitates orientation in difficult conditions in unknown terrain, poor visibility and darkness. The increased situational awareness capability gives the soldier the ability to get an overview and general knowledge about the current situation, which leads to greater efficiency during guard duty.

Research has suggested that affective states have critical effects on various cognitive processes and performance. Evidence from driving studies has also emphasized the importance of driver situation awareness (Endsley, 1995b) for driving performance and safety. However, to date, no research has investigated the relationship between affective effects and driver situation awareness. Two studies examined the relationship between a driver's affective states and situation awareness. In Experiment 1, 30 undergraduates drove in a simulator after either anger or neutral affect induction. Results suggested that an induced angry state can degrade driver situation awareness and driving performance more than the neutral state. Interestingly, the angry state did not influence participants' perceived workload. Experiment 2 explored the possibilities of using an "attention deployment" emotion regulation strategy as an intervention for mitigating angry effects on driving, via an adaptive speech-based system. 60 undergraduates drove the same scenario as in Experiment 1 after affect induction with different intervention conditions: anger with no sound; anger with the ER system: directive/ command style emotion regulation messages; anger with the SA system: suggestive/ notification style situation awareness prompts; or neutral with no sound. Results showed that both speech-based systems can not only enhance driver situation awareness and driving performance, but also reduce the anger level and perceived workload. Participants rated the ER system as more effective, but they rated the SA system as less annoying and less authoritative than the ER system. Based on the results of Experiment 2, regression models were constructed between a driver's affective states and driving performance, being mediated by situation awareness (full mediation for speeding and partial mediation for collision). These results allow researchers to construct a more detailed driver behavior model by showing how an affective state can influence driver situation awareness and performance. The practical implications of this research include the use of situation awareness prompts as a possible strategy for mitigating affective effects, for the design of an affect detection and mitigation system for drivers.

"Strong situations" have been shown to decrease behavioral variability, thereby attenuating the criterion-related validity of non-ability individual differences for criteria such as job performance (Barrick&Mount, 1993; Meyer, Dalal,&Bonaccio, 2009). However, it has been suggested that individuals, based on individual differences in implicit motives, may impute discrepant psychological meaning to social stimuli like situational strength--a process sometimes known as differential framing (James&McIntyre, 1996). If different psychological interpretations are attached to strong situation stimuli (e.g., Meyer, Dalal,&Hermida, 2010), an interesting behavioral "double-edged sword" is possible. On the one hand, behaviors pertinent to "primary criteria" (i.e., criteria for which external situational influences and pressures lead to targeted behavioral homogeneity) may occur among those who would not normally engage in them. But, at the same time, behaviors pertinent to "secondary criteria" (i.e., unintended, unforeseen, and potentially reactionary behaviors and/or attitudes) might also increase for some individuals (i.e., those with certain implicit motive characteristics). In other words, high situational strength may simultaneously constrain behavioral variability in primary criteria while serving as a stimulus for differential framing, thereby expanding variability on secondary criteria. The purpose of the present dissertation was twofold: 1) to explore the degree to which situational strength is differentially framed, and 2) to ascertain how the differential framing of situational strength may lead to unintended secondary outcomes. Study 1 findings indicate that, to a partial extent, situational strength is differentially framed by individuals with different implicit motives. Study 2 findings are largely consistent with extant situational strength theory, though partially inconsistent with study predictions.

Thesis (M.I.T.)--The Evergreen State College, 2009. / Title from title screen (viewed 7/30/2009). Includes bibliographical references (leaves 115-119).

In Space Situational Awareness (SSA), it is crucial to assess the uncertainty related to thestate vector of resident space objects (RSO). This uncertainty plays a fundamental role in, forexample, collision risk assessment and re-entry predictions. A realistic characterization of thisuncertainty is, therefore, necessary.The most common representation of orbital uncertainty is through a Gaussian (or normal)distribution. However, in the absence of new observations, the uncertainty grows over timeand the Gaussian representation is no longer valid under nonlinear dynamics like spacemechanics. This study evaluates the time when the uncertainty starts becoming non-Gaussianin nature. Different algorithms for evaluating the normality of a distribution were implemented andMonte Carlo tests were performed on them to assess their performance. Also, the distancesbetween distributions when they are propagated under linear and nonlinear algorithms werecomputed and compared to the results from the Monte Carlo statistics tests in order to predictthe time when the Gaussianity of the distribution breaks. Uncertainty propagation using StateTransition Tensors and Unscented Transform methods were also studied. Among theimplemented algorithms for evaluating the normality of a distribution, it was found thatRoyston’s method gives the best performance. It was also found that if the Normalized L 2distance between the linear and non-linear propagated distributions is greater than 95%, thenuncertainty starts to become non-Gaussian. In the best case scenario of unperturbed two-bodymotion, it is observed that the Gaussianity is preserved for at least three orbital periods in thecase of Low-Earth and Geostationary orbits when initial uncertainty corresponds to the meanprecision of the space debris catalog. If the initial variances are reduced, then Gaussianity ispreserved for a longer period of time. Time for which Gaussian assumption is valid on orbitaluncertainty is also dependent on the initial mean anomaly. Effect of coordinatestransformation on Gaussianity validity time is also analyzed by considering uncertainty inCartesian, Keplerian and Poincaré coordinate systems. This study can therefore be used to improve space debris cataloguing.

There is an emerging field in the design and development of complex systems, where systems are built upon components which in themselves are large scale systems – system of systems. Among other things, the system of systems viewpoint emphasises on open complex systems. In this thesis, the model of open computational systems is used to convey the constituents, dependencies, and interactions of such complex distributed systems. These open complex systems are exposed to critical events, occurring in the systems execution environment. Moreover, these events may have negative effects on the system at hand, resulting in system behaviour diverging from intended. Also, to take all possible affecting events in consideration when designing the system is impossible. By being able to instrument the system at hand in real time, i.e. online, one may be able to compensate the effects caused by critical events. However, to enable online instrumentation, one needs a supporting methodology which handles issues of an online nature and supporting technologies. In this thesis, this support is enabled by the methodology of online engineering and the technology of visualization. Furthermore, these instrumentations can be performed by cognitive agents – both human and software – which may explore and refine a specific system in conformance with their own, or cooperative, agendas and qualitative goals. To be able to perform the instrumentation, the cognitive agents need to be able to observe the phenomenon at hand to gain situation awareness, which in itself lies as a foundation for the decision process, carried out during the instrumentation phase. With this in mind, one quickly realizes the importance of enabling observation of open computational systems for both human and software cognitive agents. If human cognitive agents are involved in applying the methodology; the requirements on how the system is represented for the observing human agent – how the system is visualized – grows even more important. In this thesis, we emphasise visualization technology as a supporting technology for human cognitive agents in their observation process. By providing human cognitive agents with visualization technology, we may enhance the result of their observation process and thereby also increase the possibility to reach their qualitative goals. Hence, visualization of open computational systems affects a human cognitive agent’s situation awareness, which in itself lies as the foundation for the decision making process on instrumentation of the specific system at hand in conformance with the agent’s qualitative goals. This thesis will present an evaluation of a supporting tool for visualization of systemic qualities in open computational systems. Such tool must supply functions which convey the set of requirements put forward by the selected model, method, and technology. Moreover, the evaluation will be accompanied by appropriate recommendations for improvement of such a tool.