Investigation of air transportation technology at the Massachusetts Institute of Technology, 1988-1989

There are four areas of research being pursued in 1988 under sponsorship of the FAA/NASA Joint University Research Program, and one area which has been completed. The four active areas were: (1) Automatic Speech Recognition (ASR) in Air Traffic Control. The purpose of this research effort is to demonstrate the feasibility of using ASR technology within the ATC environment and to address the problems involved, especially the relevant human factors issues. (2) A Rule-Based Planning and Scheduling System. Planning denotes the formulation of a detailed scheme, program, or method worked out beforehand for the accomplishment of a goal. It involves the analysis of the desired goal and its division into sub-goals which are subsequently treated in the same way until a set of primitive objectives is obtained. (3) Modeling of Ice Accretion on Aircraft in Glaze Icing Conditions. The work in aircraft icing over the past year has focused on the fundamental aspects of glaze ice accretion, with the goal of improving analytical ice accretion models. Over the past year, studies have been conducted on the generation of surface roughness on accreting ice surfaces with the goal of providing a deterministic surface roughness in the ice accretion models. (4) Cockpit Display of Hazardous Weather Information. Information transfer and display issues associated with the dissemination of hazardous weather warnings are studied in the context of windshear alerts

Research in structures, structural dynamics and materials, 1989

Topics addressed include: composite plates; buckling predictions; missile launch tube modeling; structural/control systems design; optimization of nonlinear R/C frames; error analysis for semi-analytic displacement; crack acoustic emission; and structural dynamics

On the management and performance of a class of local area networks

This dissertation is concerned with the management and performance issues of those register-insertion (R-I) ring type local area networks (LANs) which employ the message removal by destination node protocol. A typical example of such a network is the Distributed Loop Computer Network (DLCN). developed by Liu et al for fundamental research in the field of distributed computing. After considering the management issues of low cost R-J LANs. the research deals with performance analysis of the dynamically reconfigurable register-insertion (DRR) network. In the first part of this research. a set of management functions is identified which are desirable and can be provided economically by a low cost LAN. A unique feature of the DLCN is that messages are removed from the network by the destination node. that is. messages do not travel whole of the loop. Therefore. it is not possible for a special control node to monitor the data traffic on the network without providing support functionality in each network access unit (NAU). The minimum functionality which must be provided in each NAU is identified in the thesis. A skeleton network was implemented to verify the feasibility of the proposed scheme. A paper describing the findings of this research was published and is reproduced as appendix A. In the second part of this research. a new feature of the DLCN network is introduced. namely. that the performance of a network employing removal by destination protocol can be improved by reconfiguring the network in a particular way. A methodology to find the optimal configuration is developed and is shown. by worked examples. to lead to improved performance. The findings of this research are particularly applicable to the dynamically reconfigurable register-insertion (DRR) network. A paper dealing with the optimisation of a hypothetical fully connected DRR network has been accepted for publication. Another paper. which considers the general case of less than fully connected DRR networks. is to be published. Both papers are reproduced as append ices Band C. Finally. a performance study of the ORR network is undertaken. As there seems to be no published attempt at formal analysis or simulation of a ORR network. a survey of literature dealing with performance study of the basic OLeN is performed. A simulation model of the DRR was then developed and implemented to verify the results arrived at in the previous section. Later. a queueing model of the DRR network. based on the work of Bux and Schlatter [7] is developed and analysed. Both simulation and analysis support the claim that the performance of a DRR network can be improved by adopting the configuration strategy developed in this thesis

LTE Optimization and Resource Management in Wireless Heterogeneous Networks

Mobile communication technology is evolving with a great pace. The development of the Long Term Evolution (LTE) mobile system by 3GPP is one of the milestones in this direction. This work highlights a few areas in the LTE radio access network where the proposed innovative mechanisms can substantially improve overall LTE system performance. In order to further extend the capacity of LTE networks, an integration with the non-3GPP networks (e.g., WLAN, WiMAX etc.) is also proposed in this work. Moreover, it is discussed how bandwidth resources should be managed in such heterogeneous networks. The work has purposed a comprehensive system architecture as an overlay of the 3GPP defined SAE architecture, effective resource management mechanisms as well as a Linear Programming based analytical solution for the optimal network resource allocation problem. In addition, alternative computationally efficient heuristic based algorithms have also been designed to achieve near-optimal performance

Measurements, Models, Systems and Design

531 s.