Applying random stream theory to the group target detection problem

The detection problem for a group of moving targets is a generalization of the classical detection problem for a single still target. Synthesis methods for joint detection and phase coordinate measurement for objects in the group are being developed in the theory of random streams of events. In this work, we propose a Poisson approximation for a Bernoullian stream of signals generated by a group target and observed in noises for small signal/noise ratios. Using this approximation, we can significantly simplify optimal detection and parameter estimation for a group target which are hard to implement exactly. Developing suboptimal algorithms is an important problem for a number of technical applications, including, in particular, radioand hydrolocation.     

Local path planning using a new artificial potential function composition and its analytical design guidelines

This paper presents a new framework for path planning based on artificial potential functions (APFs). In this scheme, the APFs for path planning have a multiplicative and additive composition between APFs for goal destination and APFs for obstacle avoidance, unlike conventional composition where the APF for obstacle avoidance is added to the APF for goal destination. In particular, this paper presents a set of analytical guidelines for designing potential functions to avoid local minima for a number of representative scenarios based on the proposed framework for path planning. Specifically the following cases are addressed: (i) a non-reachable goal problem (a case in which the potential of the goal is overwhelmed by the potential of an obstacle), (ii) an obstacle collision problem (a case in which the potential of the obstacle is overwhelmed by the potential of the goal) and (iii) a narrow passage problem (a case in which the potential of the goal is overwhelmed by the potential of two obstacles). The example results for each case show that the proposed scheme can effectively construct a path-planning system with the capability of reaching a goal and avoiding obstacles despite possible local minima.     

A binary modal logic for the intersection types of lambda-calculus

Intersection types discipline allows to define a wide variety of models for the type free lambda-calculus, but the Curry–Howard isomorphism breaks down for this kind of type systems. In this paper we show that the correspondence between types and suitable logical formulas can still be recovered appealing to the fact that there is a strict connection between the semantics for lambda-calculus induced by the intersection types and a Kripke-style semantics for modal and relevant logics. Indeed, we present a modal logic hinted by the analysis of the sub-typing relation for intersection types, and we show that the deduction relation for such a modal system is a conservative extension of the relation of sub-typing. Then, we define a Kripke-style semantics for the formulas of such a system, present suitable sequential calculi, prove a completeness theorem and give a syntactical proof of the cut elimination property. Finally, we define a decision procedure for theorem-hood and we show that it yields the finite model property and cut-redundancy.     

Detection of a brain aneurysm and a way to search for a brain aneurysm aimed at the development of a system to simulate an operation

In this article, a system is proposed for a simulated operation which would help a trainee surgeon to perform a medical operation to ensure that a cerebral aneurysm does not burst. The physician will have acquired empirical medical technologies from operations in traditional clinical teaching. However, there is a problem with safety and the burden to the patient. Therefore, recently a new training approach for a simulated medical operation using virtual reality has been explored. With the aim of developing a simulated system for a medical operation for a cerebral aneurysm, we considered the necessary functions such as detecting the brain aneurysm that is the target of the operation, and searching for a suitable blood vessel to make a plan for the operation.     

The Control Problem for Stage-by-Stage Changing Linear Systems of Loaded Differential Equations

We consider the control problem for stage-by-stage changing linear differential equations and the optimal control problem with a quality criterion defined for the entire time interval. We formulate necessary and sufficient conditions for complete controllability and the existence of a program control and motion. We construct an explicit form of the control action for the control problem and propose a method for solving the optimal control problem. We give a solution of the control problem for a specific loaded system.     

Constructive Lyapunov stabilization of nonlinear cascade systems

We present a global stabilization procedure for nonlinear cascade and feedforward systems which extends the existing stabilization results. Our main tool is the construction of a Lyapunov function for a class of (globally stable) uncontrolled cascade systems. This construction serves as a basis for a recursive controller design for cascade and feedforward systems. We give conditions for continuous differentiability of the Lyapunov function and the resulting control law and propose methods for their exact and approximate computation     

A methodology for designing toolkits for specification level verification of interval-constrained information systems requirements

In developing automated tools for verification for an Information systems (IS), there exists a need for a methodology for the development of information requirements maintenance toolkits which will maintain IS with unconstrained and constrained requirements. In this paper, we present a methodology for building generalized designs of IS maintenance toolkits that maintain the requirements specification of IS. Our methodology will decrease the effort in building and increase the structural quality of IS maintenance toolkits that are used for verification of an IS in areas such as command, control, communication, computer, intelligence, surveillance, and reconnaissance (C⁴ISR) organizations. The methodology represents a reuse-oriented Unified Modeling Process (UMP) and consists of a method for developing an enterprise model, a method for developing use cases of the toolkit services, a method for developing logic designs and a method for developing the component view of the software.     

A hierarchically structured and constraint-based data model for intuitive and precise solid modeling in a virtual reality environment

This article proposes a hierarchically structured and constraint-based data model for intuitive and precise solid modeling in a virtual reality (VR) environment. The data model integrates a high level constraint-based model for intuitive and precise manipulation, a middle level solid model for complete and precise representation and a low-level polygon mesh model for real-time interactions and visualization in a VR environment. The solid model is based on a hybrid B-rep/CSG data structure. Constraints are embedded in the solid model and are organized at hierarchical levels as feature constraints among internal feature elements, part constraints among internal features and assembly constraints between individual parts. In addition to providing a complete and precise model representation and the support for real-time visualization, the proposed data model permits intuitive and precise interaction through constraint-based manipulations for solid modeling in a VR environment. This is a critical issue for product design in a VR environment due to the limited resolutions of today's VR input and output devices.     

Trust management and trust theory revision

A theory of trust for a given system consists of a set of rules that describe trust of agents in the system. In a certain logical framework, the theory is generally established based on the initial trust of agents in the security mechanisms of the system. Such a theory provides a foundation for reasoning about agent beliefs as well as security properties that the system may satisfy. However, trust changes dynamically. When agents lose their trust or gain new trust in a dynamic environment, the theory established based on the initial trust of agents in the system must be revised, otherwise it can no longer be used for any security purpose. This paper investigates the factors influencing trust of agents and discusses how to revise theories of trust in dynamic environments. A methodology for revising and managing theories of trust for multiagent systems is proposed. This methodology includes a method for modeling trust changes, a method for expressing theory changes, and a technique for obtaining a new theory based on a given trust change. The proposed approach is very general and can be applied to obtain an evolving theory of trust for agent-based systems.     

Limits of generalized state space systems under proportional and derivative feedback

In this paper we study the high-gain feedback classification problem for generalized state space systems. We solve this problem for proportional and derivative feedback transformations of regularizable systems, i.e., we give necessary and sufficient conditions for a regularizable system to be a limit of a given system under high-gain proportional and derivative feedback. We also derive a new complete set of invariants for proportional feedback equivalence and specify a set of necessary conditions for a system to be the limit of another system under these feedback transformations. The necessary conditions are sufficient for arbitrary state space systems and for controllable singular systems.     

Robust image registration by increment sign correlation

A novel and robust statistic as a similarity measure for robust image registration is proposed. The statistic is named as increment sign correlation because it is based on the average evaluation of incremental tendency of brightness in adjacent pixels. It is formalized to be a binary distribution or a Gaussian distribution for a large image size through statistical analysis and modeling. By utilizing the proposed statistical model, for example, we can theoretically determine a reasonable value of threshold for verification of matching. This sign correlation can also be proved to expectedly have the constant value 0.5 for any uncorrelated images to a template image, and then the property of the constancy can be utilized to analyze the high robustness for occlusion. The good performance for the case of saturation or highlight can also be proved through theoretical analysis and fundamental experiments. A basic algorithm for image scanning, search and registration over a large scene is represented with a technique for a fast version by the branch-and-bound approach. Many experimental evidences with real images are provided and discussed.     

Finding a suitable checkpoint and recovery protocol for a distributed application

Checkpoint and recovery protocols are commonly used in distributed applications for providing fault tolerance. The performance of a checkpoint and recovery protocol is judged by the amount of computation it can save against the amount of overhead it incurs. This performance depends on different system and application characteristics, as well as protocol specific parameters. Hence, no single checkpoint and recovery protocol works equally well for all applications, and given a distributed application and a system it will run on, it is important to choose a protocol that will give the best performance for that system and application. In this paper, we present a scheme to automatically identify a suitable checkpoint and recovery protocol for a given distributed application running on a given system. The scheme involves a novel technique for finding the similarity between the communication pattern of two distributed applications that is of independent interest also. The similarity measure is based on a graph similarity problem. We present a heuristic for the graph similarity problem. Extensive experimental results are shown both for the graph similarity heuristic and the automatic identification scheme to show that an appropriate checkpoint and recovery protocol can be chosen automatically for a given application.     

On segmenting logistical zones for servicing continuously developed consumers

We study the optimal placement problem for several logistical objects. A characteristic feature of this problem is the need for sequential segmentation into servicing zones and accounting for population distributed continuously across the entire region. We reduce this problem to a variational calculus problem in a special form. To study this problem, we develop numerical algorithms that are able to determine the optimal placement of a logistical object inside a given segment. The algorithms are based on constructing wavefronts for a light wave emitted from the boundary of the chosen region. The wave moves inside the region, which lets us account for all inhabitants in this region. In constructing the solution, we have accounted for the loss of smoothness in the wavefront, have developed a software implementation for the computational algorithms, and have conducted a numerical experiment for a number of model problems.     

A Knowledge-Based System for Designing Testable VLSI Chips

The complexity of VLSI circuits has increased the need for design for testability (DFT). Numerous techniques for designing more easily tested circuits have evolved over the years, with particular emphasis on built-in testing approaches. What has not evolved is a design methodology for evaluating and making choices among the numerous existing approaches. This article describes efforts to build a knowledge-based expert system for designing testable VLSI chips. A framework for a methodology incorporating structural, behavioral, qualitative, and quantitative aspects of known DFT techniques is introduced. This methodology provides a designer with a systematic DFT synthesis approach. The process of partitioning a design into subcircuits for individual processing is described and a new concept?I-path?is used to transfer data from one place in the circult to another. Rules for applying testable design methodologies to circuit partitions and for evaluating the various solutions obtained are also presented. Finally, a case study using a prototype system is described.     

Power and sample size requirements for non-inferiority in studies comparing two matched proportions where the events are correlated

Consider clustered matched-pair studies for non-inferiority where clusters are independent but units in a cluster are correlated. An inexpensive new procedure and the expensive standard one are applied to each unit and outcomes are binary responses. Appropriate statistics testing non-inferiority of a new procedure have been developed recently by several investigators. In this paper, we investigate power and sample size requirement of the clustered matched-pair study for non-inferiority. Power of a test is related primarily to the number of clusters. The effect of a cluster size on power is secondary. The efficiency of a clustered matched-pair design is inversely related to the intra-class correlation coefficient within a cluster. We present an explicit formula for obtaining the number of clusters for a given cluster size and the cluster size for a given number of clusters for a specific power. We also provide alternative sample size calculations when available information regarding parameters are limited. The formulas can be useful in designing a clustered matched-pair study for non-inferiority. An example for determining sample size to establish non-inferiority for a clustered matched-pair study is illustrated.     

Static Analysis of Object References in RMI-Based Java Software

Distributed applications provide numerous advantages related to software performance, reliability, interoperability, and extensibility. This paper focuses on distributed Java programs built with the help of the remote method invocation (RMI) mechanism. We consider points-to analysis for such applications. Points-to analysis determines the objects pointed to by a reference variable or a reference object field. Such information plays a fundamental role as a prerequisite for many other static analyses. We present the first theoretical definition of points-to analysis for RMI-based Java applications, and we present an algorithm for implementing a flow- and context-insensitive points-to analysis for such applications. We also discuss the use of points-to information for corrupting call graph information, for understanding data dependencies due to remote memory locations, and for identifying opportunities for improving the performance of object serialization at remote calls. The work described in this paper solves one key problem for static analysis of RMI programs and provides a starting point for future work on improving the understanding, testing, verification, and performance of RMI-based software     

SYSTAT: Leland Wilkinson. Evanston,IL: SYSTAT,Inc., 1984. Documentation and Five Diskettes, $595.00 (IBM Version Reviewed)

SYSTAT appears to be a flexible microcomputer statistics system for professional statisticians. It is fast, provides clear output, and has routines for completing most common analytic procedures. In addition, the cost, although changing frequently, always seems reasonable for such a powerful package, and availability of support seems to be adequate. I would not recommend it as a teaching tool, but it could be used in a statistics course as a good example of the power of the microcomputer for statistical analysis; for most courses, it could be used in lieu of a mainframe package. I recommend it for those looking for a general purpose statistical package for most common brands of microcomputers.     

RÉSUMÉ: A Temporal-Abstraction System for Patient Monitoring

RÉSUMÉ is a system that performs temporal abstraction of time-stamped data. The temporal-abstraction task is crucial for planning treatment, for executing treatment plans, for identifying clinical problems, and for revising treatment plans. The RÉSUMÉ system is based on a model of three basic temporal-abstraction mechanisms: point temporal abstraction, a mechanism for abstracting the values of several parameters into a value of another parameter; temporal inference, a mechanism for inferring sound logical conclusions over a single interval or two meeting intervals; and temporal interpolation, a mechanism for bridging nonmeeting temporal intervals. Making explicit the knowledge required for temporal abstraction supports the acquisition and the sharing of that knowledge. We have implemented the RESUME system using the CLIPS knowledge-representation shell. The RÉSUMÉ system emphasizes the need for explicit representation of temporal-abstraction knowledge, and the advantages of modular, task-specific but domain-independent architectures for building medical knowledge-based systems.