The purpose of this thesis is to explore how support systems enable human control within normal flight operations. The thesis focuses on the use of memory supports during flight, such as a handheld computing device, memory strategies and checklists. The support systems are studied from the theoretical perspective of Human Factors. In particular, decision making theories have contributed to the thesis. From previous research it is found that feedback to the operator in case of a human error is essential to keep him or her in a safe sequence of decisions and actions. To facilitate the pilots’ tasks in cockpit, computing devices are out on the market. Several of the technical aids are computers installed in cockpit whereas others are smaller, portable devices with hardware not specifically designed for use in cockpit. Jump-seat observations have been performed at an airline company to explore the pilots’ work process in cockpit where a handheld computing device, with hardware not specifically designed for cockpit, is in use. Subsequent semi-structured interviews were conducted to receive the pilots’ experiences of findings from the observations and to receive descriptions of decisions and support systems. The thesis includes a description of flight operations from a pilot perspective. The main focus is on operations in the preflight phase where the new computing device is used. Identified characteristics in flight operations are factors such as cooperation, communication, interruptions. Furthermore, identified factors in the decision making were such as routine, environmental constraints, discrete alternatives and dependency between decisions. Feedback points during the sequence of tasks performed with the handheld computing device were distinguished. These points are moments when feedback is possible. For example, when the pilots cross-check tasks they receive feedback from each other. It was found that the pilots did not use every opportunity to receive feedback on their performance. The reason of the non-used feedback point was that it was not required by the Standard Operating Procedures or by any functions or design of the device. Within flight operations in general, it was found that the most important techniques to detect a human error such as a memory lapse were by pilots’ earlier experiences, the use of checklists and by receiving feedback from the other pilot. / QC 20101109

Decision making in a parallel human/computer system is considered. In this type of system, those tasks for which the computer identical to has the decision making responsibility tasks for which the human are has responsibility. For optimal system performance, it is crucial that the human and computer avoid redundant actions. The traditional method of avoiding redundancies is to have the human engage in an. explicit dialogue with the computer. This method adds an additional task for the human. An alternative method which does not increase workload is to provide the computer with a model of human decision making. If this model is accurate, the computer could predict the actions of the human and avoid those actions which are redundant. The mathematical development of such a predictive model is presented. The model suggested has two stages. The first stage uses discriminant analysis to describe human event detection behavior. The output from the first stage of the model is a vector of "event detected" probabilities, each entry in the vector representing a different system task. The second stage of the model uses dynamic programming to determine the optimal action at a specific point in time. The output from this stage of the model is the appropriate action for the human to take. Two experiments were presented to validate the first and second stage of the model, respectively. The experimental situation depicted a sheet metal plant in which the subjects were to monitor machines for failures. The first stage of the model predicted over 80% of the actions correctly, while the entire model predicted nearly 85% correctly. In the third experiment, the computer was implemented as a parallel decision maker. A significant improvement in performance was observed when the computer based decisions on a model of human decision making vs. when the model was ignored. A modeling approach is suggested as a reasonable alternative to explicit human/computer systems. communication in the design of Further research is suggested to determine the situations in which model based communication would be preferable to dialogue based communication. / Ph. D.

Little research effort has been devoted to human interaction with telephone information systems. This study investigated the effects of system parameters and user characteristics on human behavior in an interactive telephone-based information system. The research method utilized a centraI-composite design to study four variables at five levels each. The four factors manipulated were: synthesized speech rate, time available for user input, subject age, and background music level. Subjects searched a fictitious department store database for 16 specific store items and transcribed 16 information messages which were spoken by a computer speech synthesizer. Subjective ratings of certain features of the system were solicited from the subjects and performance measures were also collected from the subjects on an on-line basis. Performance was evaluated by calculating regression equations relating the dependent measures and the independent variables. A response surface was plotted, and optimal settings for the Information system were also calculated. Two seconds was found to be an optimal time for users to enter their selection. The computer synthesized speech rate should be set close to 120-150 words per minute. Background music or noise level should be kept below 50 dB(A); sound level above 50 dB(A) seriously affected user's ability to understand synthetic speech. Younger subjects (age 14 - 22) performed better in this study than older subjects (age 36- 62). / Master of Science / incomplete_metadata

This study examined the effects of five dichotomous variables on human performance using a computer-based telephone information system. The five variables were: speech rate (120 or 240 words per minute), length of input time-out (two or ten seconds), feedback (available or not available), wallet guide - a graphical representation of the information (available or not available), and the database structure (8x2 or 2x6). The research methodology implemented a one-half fraction of a 2⁵ factorial design, requiring only 16 of the 32 possible treatment combinations. Two tasks were included in this study: a search task and a transcription task. The search task consisted of each subject accessing an information system through a touch-tone telephone. The subject listened to the computer as it used synthesized speech to list available menu options. The search task continued until the subject found the target item. The transcription task consisted of listening to and typing an information message for each target item. The experiment ended when 16 target items were found. Four dependent measures were used to evaluate user performance. The search task was evaluated with three measures: user added time (the amount of additional time the subject required to complete the search in excess of the minimum search time imposed by the system design); invalid key presses (the number of times undefined keys on the touch tone telephone were pressed during the search); and user added key presses (the number of additional, valid key presses the subject required to complete the search in excess of the minimum number of key presses required to complete the search). Only one measure was used to evaluate user performance of the transcription task: transcription accuracy score (the number of words that each subject transcribed correctly). The results show four of the five variables (speech rate, database structure, input time-out, and wallet guide) to have a significant effect on human performance. The following interactions were found to have a significant effect on at least one of the dependent measures: database structure by input timeout, database structure by wallet guide, input timeout by wallet guide, and speech rate by wallet guide. Twelve subjective ratings were also analyzed. The results show at least one of the 12 subjective ratings was significantly affected by speech rate, input time-out, or the database structure. Perhaps the most important finding of this research is that complicated auditory information structures can be accessed easily if a wallet guide is provided. In addition to decreasing search time, a wallet guide reduces the number of search errors users make. / Master of Science

The machines and vehicles of today are very advanced with several electronic controlunits (ECUs) tasked with monitoring and performing various tasks. These ECUs com-municate with each other via the onboard Control Area Network (CAN bus). When anerror occurs or the need for maintenance arises, an external computer needs to be con-nected to the control area network (CAN bus) to enable, among others, troubleshootingand maintenance of the various ECUs connected to the system.The central question we explore in this thesis is whether it’s feasible and practical tomove the service system library for these machines onto an existing resource-constrainedECU with a display already present within the system, thereby eliminating the need foran external computer. This solution streamlines maintenance processes by increasing themaintainability of the machines and vehicles when an external computer is not availableand reduces downtime by lowering the Mean Time To Diagnose (MTTD).In the end, a majority of the main functions of the service library were integrated intoan ECU with a display, only missing the ability to flash new firmware to other deviceswithin the CAN bus system. This proves that the theory behind the project is correct, andwith more time the missing feature could have been implemented.

Thesis: B.S., Massachusetts Institute of Technology, Department of Mechanical Engineering, 1981 / Lacks leaf 38. / by Eric Brian Shain. / B.S. / B.S. Massachusetts Institute of Technology, Department of Mechanical Engineering

The work presented in this thesis provides new perspectives and approaches for problems that arise in the analysis of neural data. Particular emphasis is placed on parameter fitting and automated analysis problems that would arise naturally in closed-loop experiments. Part one focuses on two brain-computer interface problems. First, we provide a framework for understanding co-adaptation, the setting in which decoder updating and user learning occur simultaneously. We also provide a new perspective on intention-based parameter fitting and tools to extend this approach to higher dimensional decoders. Part two focuses on event inference, which refers to the decomposition of observed timeseries data into interpretable events. We present application of event inference methods on voltage-clamp recordings as well as calcium imaging, and describe extensions to allow for combining data across modalities or trials.

Haptic devices allow a human to interact physically with a remote or virtual environment by providing tactile feedback to the user. In general haptic devices can be classified in two groups according to the energetic nature of their actuators. Devices using electric motors, pneumatic or hydraulic cylinders or other similar actuators that can add energy to the system are considered "active." Devices using brakes, clutches or other passive actuators are considered "passive" haptic devices. The research presented here focuses on the use of passive haptic devices used during teleoperation, the remote control of a "slave" device by the haptic "master" device. An actuation scheme as well as three different control methods is developed for providing the user with haptic feedback. As a final step, the effectiveness of the controllers is compared to that of a commercially available active haptic device. Twenty subjects provide data that shows the usefulness of the passive device in three typical teleoperation tasks.

This research explores an approach to learning types of usability concerns considered useful for the management of Web sites and to identifying usability concerns based on these learned models. By having one or more Web site managers rate a subset of pages in a site based on a number of usability criteria, the approach builds models that determine what automatically measurable characteristics are correlated to issues identified. To test this, the approach collected usability assessments from twelve students pursuing advanced degrees in the area of computer-human interaction. These students were divided into two groups and given different scenarios of use of a Web site. They assessed the usability of Web pages from the site, and their data was divided into a training set, used to find models, and a prediction set, used to evaluate the relative quality of models. Results show that the learned models predicted remaining data for one scenario in more categories of usability than did the single model found under the alternate scenario. Results also show how systems may prioritize usability problems for Web site managers by probability of occurrence under context rather than by merely listing pages that break specific rules, as provided by some current tools.

The appearance of the electrical appliances has undergone a dramatic change in many aspects since the 1920&rsquo / s. Throughout years, along with their changed appearance, the way the appliances are perceived has altered. The interface of domestic products is mainly dominated by visual elements. Undoubtedly, the domination of the visual perception in the interfaces of the appliances might cause complications in the interaction between the product and visually impaired users. In this thesis, the interaction between the electrical household appliances and visually impaired user is examined to identify the strong points in the interaction as well as any complications that may occur during the interaction. Observations were conducted with ten users to explore the interaction between the visually impaired users and three electrical domestic appliances: washing machine, vacuum cleaner and iron. The findings of the observations indicate that visually impaired users can operate their appliances, with some limitations. Yet a number of common problematic points related to the interface elements, which hinder from using their electrical appliances with full functionality, were encountered. At the end of the study, a list of design recommendations, some of which offered in the literature previously, are suggested.