@conference {
	title = {Finite-Dimensional Methods for Computing the Information State in Nonlinear Robust Control},
	author = {Baras, John S., Darling, RWR.},
	year = {1998},
	month = {12/1998},
	abstract = {In nonlinear output robust control and in nonlinear risk sensitive partially observed stochastic control, the optimal control is a memoryless function of the information state. The information state dynamics are directly influenced by the control performance metric, thus displaying a direct linkage between control objectives and sufficient statistics for control. It has been observed in several examples that by modifying the control performance metric one can render the dynamics of the information state finite dimensional. In linear robust control, it is well known that the information state can be computed by a simple finite-dimensional formula. Using the Lie theory for transformations of this basic solution, we show how the information state for certain nonlinear control problems can also be obtained using finite-dimensional calculations, e.g.. via the solution of systems of ODEs. This is explained using fundamental results on the invariance groups of the equations involved. An intuitive interpretation of the significance of the result is also provided.},
	address = {Tampa, Florida},
	booktitle = {37th IEEE Conference on Decision and Control}
}
@conference {
	title = {University-Industry Collaboration},
	author = {Baras, John S.},
	year = {1998},
	month = {12/1998},
	address = {Washington DC},
	booktitle = {Workshop on Enhancing Academic Research Contributions to the Aerospace Industry},
	organization = {National Academy of Engineering }
}
@conference {
	title = {Information Based Complex Systems Design},
	author = {Baras, John S.},
	year = {1998},
	month = {11/1998},
	address = {Link{\"o}ping, Sweden},
	booktitle = {Annual Review Workshop, ISIS Competence Center},
	organization = {Link{\"o}ping University}
}
@conference {
	title = {A Distributed Shared Key Generation Procedure Using Fractional Keys},
	author = {Poovendran, Radha., Corson, Scott M., Baras, John S.},
	year = {1998},
	month = {10/1998},
	abstract = {We present a new class of distributed key generation and recovery algorithms suitable for group communication systems where the group membership is either static or slowly time-varying, and must be tightly controlled. The proposed key generation approach allows entities which may have only partial trust in each other to jointly generate a shared key without the aid of an external third party. The group collectively generates and maintains a dynamic group parameter, and the shared key is generated using a pseudo random function using this parameter as a seed. The validity of key generation can be checked using veriable secret sharing techniques. The key retrieval method does not require the keys to be stored in an external retrieval center. We note that many Internet-based applications may have these requirements. Fulllment of these requirements is realized through the use of fractional keys-a distributed technique recently developed to enhance the security of distributed systems in a non-cryptographic manner.},
	address = {Bedford, MA},
	booktitle = {MILCOM\&rsquo;98},
	pages = {pp. 1-6}
}
@conference {
	title = {Group Invariance and Symmetries in Control Systems and Mathematical Physics},
	author = {Baras, John S.},
	year = {1998},
	month = {10/1998},
	address = {Cambridge, Massachusetts},
	booktitle = {Perspectives in Control, honoring Professor Roger W. Brockett on his 60th birthday}
}
@conference {
	title = {Systems and Control Education as Foundation of Systems Engineering Education},
	author = {Baras, John S.},
	year = {1998},
	month = {10/1998},
	address = {Champaign, IL},
	booktitle = {NSF Workshop on New Directions in Control Engineering Educatio},
	organization = {University of Illinois at Urbana-Champaign}
}
@conference {
	title = {Web-it-Man: A Web-based Integrated Tool for Manufacturing Environment},
	author = {Karne, Ramesh K., Baras, John S., Nau, Dana S., Ball, Michael O., Lin, Edward., Trichur, Vinai., Dandekar, Swati V., Poluri, Sridhar., Williams, James T.},
	year = {1998},
	month = {09/1998},
	abstract = {Exponential growth in Internet applications and a need for a global access for future manufacturing demands web-based tools that operate seamlessly in heterogeneous environments. We present a Web-based Integrated Tool for Manufacturing that assists designers with a variety of CAD/CAM tools through a unified user interface. Web enabled system architecture is proposed for the future development of manufacturing tools. Design issues and research topics pertinent to this architecture are described. A prototype implementation based on this architecture and its current status is outlined. Finally, our research efforts in the development of this tool and some future research areas are identified.},
	address = {Atlanta, GA},
	booktitle = {1998 ASME Design Technical Conferences, ASME Computers in Engineering Conference},
	pages = {pp. 1-12}
}
@conference {
	title = {Process Planning in Microwave Module Production},
	author = {Meyer, Jeff., Ball, Mike., Baras, John S., Chowdhury, Abdur., Lin, Edward., Nau, Dana S., Rajamani, Ravi., Trichur, Vinai.},
	year = {1998},
	month = {08/1998},
	abstract = {This paper describes the development of a process planning module for an integrated production and process design (IPPD) tool which automates the design and manufacture of microwaves modules. Specifically, this paper presents a process template that is used to interface with multiobjective optimization techniques to create a planner that can consider alternative designs based on process yields, cost, and manufacturing and purchasing lead tiems. The integrations of the planner and the tradeoff optimization modules provides the designer immediate feedback on cost and productivity through generation and evaluation of alternative designs early in the design state.},
	address = {Albuquerque, New Mexico},
	booktitle = {SIGMAN: Artificial Intelligence and Manufacturing: State of the Art and State of Practice},
	pages = {pp. 120-126}
}
@conference {
	title = {Flow Control and Dynamic Service Allocation in DBS-Based Internet},
	author = {Baras, John S., Olariu, Gabriel L. },
	year = {1998},
	month = {06/1998},
	abstract = {This paper describes the development of a process planning module for an integrated product and process design (IPPD) tool which automates the design and manufacture of microwave modules. Specifically, this paper presents a process template that is used to interface with multi-objective optimization techniques to create a planner that can consider alternative designs based in process yields, cost, and manufacturing and purchasing lead times. The integration of the planner and the tradeoff optimization modules provides the designer immediate feedback on cost and productivity through generation and evaluation of alternative designs early in the design stage.},
	address = {Cleveland, Ohio},
	booktitle = {Satellite Networks: Architectures, Applications and Technologies Workshop},
	pages = {pp. 489-498},
	organization = {NASA Lewis Research Center}
}
@conference {
	title = {Scalable Coding of Video Objects},
	author = {Haridasan, Radhakrishnan., Baras, John S.},
	year = {1998},
	month = {05/1998},
	abstract = {This paper provides a methodology to encode video objects in a scalable manner with regard to both content and quality. Content scalability and quality scalability have been identified as required features in order to support video coding across different environments. Following the object-based approach to coding video, we extend our previous work on motion-based segmentation by using a time recursive approach to segmenting image sequences and decomposing a video "shot" into its constituent objects. Our formulation of the segmentation problem enables us to design a codec in which the information (shape, texture and motion) pertaining to each video object is encoded independently of the other. The multiresolution wavelet decomposition used in encoding texture information is shown to be helpful in providing spatial scalability. Our codec design is also shown to be temporally scalable.},
	address = {Monterey, CA},
	booktitle = {IEEE International Symposium on Circuits and Systems 1998 (ISCAS\&rsquo;98)},
	pages = {pp. 289-292}
}
@conference {
	title = {Hybrid Communication Networks: Modeling, Performance Evaluation and Broadband Data Services},
	author = {Baras, John S.},
	year = {1998},
	month = {04/1998},
	booktitle = {ARL Federated Lab Distinguished Lecture},
	organization = {ARL}
}
@conference {
	title = {Hybrid Communication Networks: The Last Mile and Efficient Broadband Service Provision},
	author = {Baras, John S.},
	year = {1998},
	month = {04/1998},
	address = {Boston, Massachusetts},
	booktitle = {AA/EECS Departments seminar on Innovative Directions in Communications},
	organization = {MIT}
}
@conference {
	title = {Wavelet-Based Hierarchical Organization of Large Image Databases:~ ISAR and Face Recognition},
	author = {Baras, John S., Wolk, Sheldon I.},
	year = {1998},
	month = {04/1998},
	abstract = {We present a method for constructing efficient hierarchical organization of image databases for fast recognition and classification. The method combines a wavelet preprocessor with a Tree-Structured-Vector-Quantization for clustering. We show results of application of the method to ISAR data from ships and to face recognition based on photograph databases. In the ISAR case we show how the method constructs a multi-resolution aspect graph for each target.},
	address = {Orlando, Florida},
	booktitle = {SPIE 12th International Symposium on Aerospace, Defense Sensing, Simulation and Control},
	pages = {pp. 546-558}
}
@conference {
	title = {Integrated Product and Process Design for Electromechanical Products},
	author = {Baras, John S.},
	year = {1998},
	month = {04/1998},
	address = {Boston, Massachusetts},
	booktitle = {Lean Manufacturing Program},
	organization = {MIT}
}
@conference {
	title = {Fast Internet Services via Direct Broadcast Satellites},
	author = {Baras, John S., Kenyon, J.},
	year = {1998},
	month = {03/1998},
	address = {College Park, MD},
	booktitle = {Three-Presidents Summit, A Industry-University collaboration},
	organization = {University of Maryland}
}
@conference {
	title = {Progressive Classification: Universal Algorithms and Applications},
	author = {Baras, John S.},
	year = {1998},
	month = {03/1998},
	address = {Boston, Massachusetts},
	booktitle = {Laboratory for Information and Decision Systems Colloquium},
	organization = {MIT}
}
@conference {
	title = {High Performance IP Multicasting Over Wireless Satellite-Terrestrial Networks},
	author = {Baras, John S., Secka, Isatou.},
	year = {1998},
	month = {02/1998},
	abstract = {We describe our work on IP multicast extensions to the wireless hybrid network described. We describe effective extensions of IGMP, and asymmetric multicast algorithms that exploit the asymmetry to increase the number of users, scale-up and improve the loading of the terrestrial components. This requires an asymmetric multicast routing mechanism. We describe enhancements to existing multicast routing protocols such as CBT to the hybrid environment described here. We provide results on performance of our proposed hybrid multicast algorithms with respect to the following performance metrics: time to join a group; time for a packet to reach every member of the multicast group; performance with large multicast groups.},
	booktitle = {17th AIAA International Communications Satellite Systems Conference and Exhibit}
}
@conference {
	title = {Linking Satellites and Terrestrial Networks for Digital Connectivity},
	author = {Baras, John S.},
	year = {1998},
	month = {02/1998},
	address = {Boston, Massachusetts},
	booktitle = {EECS Department Colloquium},
	organization = {MIT}
}
@conference {
	title = {Performance Evaluation in Multi-Rate, Multi-Hop Communication Networks with Adaptive Routing},
	author = {Liu, Mingyan., Baras, John S., Misra, Archan.},
	year = {1998},
	month = {02/1998},
	abstract = {Accurate performance evaluation has always been an important issue in network design and analysis. Discrete event simulation has been known to be accurate but very time consuming. Thus analytical methods/approximation is necessary for real time estimation, large scale network optimization and sensitivity analysis. In a circuit-switched loss network, a~particular performance metric of interest is the end-to-end blocking probability. Various analytical approaches and approximation schemes have been suggested for this problem and among them, the fixed-point method, or reduced load method, has ~received~much attention. However, most of these schemes either consider only single traffic rate situations or multi-rate traffic under fixed routing. We develop an approximation scheme to estimate end-to-end blocking probability in a multi-rate multi-hop network with an adaptive routing scheme. The approximation results are compared with that of discrete event simulation. An example of application is also provided in which the proposed scheme is linked to the optimization tool CONSOL-OPTCAD to get network design trade-offs. The method described here is readily applicable to accurate performance evaluation of military networks which are often large and hybrid.},
	address = {College Park, Maryland},
	booktitle = {ARL Federated Laboratory 2nd Annual Conference},
	pages = {pp. 136-140},
	organization = {University of Maryland}
}
@conference {
	title = {A Scalable Extension of Group Key Management Protocol},
	author = {Poovendran, Radha., Ahmed, S., Corson, Scott M., Baras, John S.},
	year = {1998},
	month = {02/1998},
	abstract = {This paper presents a robust, scalable extension to the recently proposed multicast Group Key Management Protocol (GKMP) ([1], [2]), in terms of security administration. The GKMP has two major security related problems: (a) lack of any mechanism to remove a compromised group administrator, and (b) lack of scalability. We are able to remove a compromised single panel member from generating the group keys by setting the panel members with shared authority to generate the group keys. We then introduce the sub-controllers who have all the functionalities of the group control panel except the authority to generate the group keys. The sub-control panel helps scalability of the network in terms of the security operations. The sub-controllers are chosen using a threshold-based clustering algorithm.},
	address = {College Park, Maryland},
	booktitle = {ARL Federated Laboratory 2nd Annual Conference},
	pages = {pp. 187-191},
	organization = {University of Maryland}
}
@conference {
	title = {Accurate Segmentation and Estimation of Parametric Motion Fields for Object-Based Video Coding Using Mean Field Theory},
	author = {Haridasan, Radhakrishnan., Baras, John S.},
	year = {1998},
	month = {01/1998},
	abstract = {We formulate the problem of decomposing a scene into its constituent objects as one of partitioning the current frame into objects comprising it. The motion parameter is modeled as a nonrandom but unknown quantity and the problem is posed as one of Maximum Likelihood (ML) estimation. The MRF potentials which characterize the underlying segmentation field are defined in a way that the spatio-temporal segmentation is constrained by the static image segmentation of the current frame. To compute the motion parameter vector and the segmentation simultaneously we use the Expectation Maximization (EM) algorithm. The E-step of the EM algorithm, which computes the conditional expectation of the segmentation field, now reflects interdependencies more accurately because of neighborhood interactions. We take recourse to Mean Field theory to compute the expected value of the conditional MRF. Robust M-estimation methods are used in the M- step. To allow for motions of large magnitudes image frames at various scales and the EM procedure is embedded in a hierarchical coarse-to-fine framework. Our formulation results in a highly parallel algorithm that computes robust and accurate segmentations as well as motion vectors for use in low bit rate video coding.},
	address = {San Jose, CA},
	booktitle = {SPIE 10th Annual Symposium on Visual Communications and Image Processing 1998 (VICP \&rsquo;98)},
	pages = {pp. 361-369}
}
@conference {
	title = {Internet Service via Broadband Satellite Networks},
	author = {Butts, Norman P., Bharadwaj, Vijay G., Baras, John S.},
	year = {1998},
	month = {01/1998},
	abstract = {The demand for Internet bandwidth has grown rapidly in the past few years. A new generation of broadband satellite constellations promise to provide high speed Internet connectivity to areas not served by optical fiber, cable, or other high speed terrestrial connections. However, using satellite links to supply high bandwidth has been difficult due to problems with inefficient performance of the Internet{\textquoteright}s TCP/IP protocol suite over satellite. We describe an architecture for improving the performance of TCP/IP protocols over heterogeneous network environments, especially networks containing satellite links. The end-to-end connection is split into segments, and the protocol in the satellite segment is optimized for the satellite link characteristics. TCP congestion control mechanisms are maintained on each segment, with some coupling between the segments to produce the effect of end-to-end TCP flow control. We have implemented this design and present results showing that using such gateways can improve throughput for individual connections by a large factor over paths containing a satellite link.},
	address = {Boston, Massachusetts},
	booktitle = {SPIE Voice, Video and Data Communications Symposium}
}
