6292073
Real-time pose estimation for outdoor mobile robots using range data
Pose estimation is a key issue in mobile robots and important to moving object tracking. In this paper, we present a tangent based hybrid pose estimation algorithm with real-time performance using range data from laser radar, which consists of Iterative Tangent weighted Closest Point (ITCP) and Hough transform based Tangent Angle Histogram (HTAH) algorithms to overcome problems with past methods, such as local minimum, aperture-like, and high computation problems. The algorithm has been tested on both synthetic and real range data in outdoor environments. Experimental results demonstrate its high accuracy, low computation, wide applicability and high robustness to aperture-like problems, occlusion and noise.
2699916
Deception Detection Via Blob Motion Pattern Analysis
Deception dectection is one of the most difficult problems in affect recognition and expression research area. Recently, non-verbal methods of detecting deception have appeared to be promising. Thomas[1] presented a proof-of-concept study based on the blob analysis of some suspects' interviews and mock experiments video clips. In this paper, we present our recent research work in the direction of developing an automated deception detection system. We propose a blob motion pattern analysis approach to solve this problem.
9404376
An XML-Based Implementation of Multimodal Affective Annotation
In simple cases, affective computing is a computational device recognizing and acting upon the emotions of its user or having (or simulating having) emotions of its own in complex cases. Multimodal technology is currently one of the hottest focuses in affective computing research. However, the lack of a large-scale multimodal database limits the research to some respective and scattered fields, such as affective recognition by video or by audio. This paper describes the development and implementation of an XML-based multimodal affective annotation system which is called MAAS (Multimodal Affective Annotation System). MAAS contains a hierarchical affective annotation model based on the 3-dimensional affect space derived from Mehrabian’s PAD temperament scale. The final annotation file is formed in XML format in order to interchange the resources with other research groups conveniently.
11690974
Inferno: a functional simulation infrastructure for modeling microarchitectural data speculations
This paper presents key insights and design rationales behind Inferno, a functional simulation construction framework developed at Intel to support execution-driven cycle-accurate performance modeling and simulation of advanced microarchitectural data speculation techniques for future processor designs and explorations. Inferno divides the task of functional simulation into three essential components, namely: (1) context manager of in-flight speculatively executed instructions, (2) stateless emulator of instruction semantics, and (3) a high speed functional simulator capable of booting OS and running large-scale system workloads. These building block components work together in concert via a set of well-architected functional model convergence APIs. With a novel abstraction called speculative domain, the context manager serves effectively as a relational database about the in-flight instructions and on-going speculations. Through a set of functional model usage APIs, the context manager enables performance models to express arbitrary microarchitectural data speculation scenarios. The contribution of this paper is to demonstrate the importance of providing a functional model with modular construction, proper abstraction and expressive APIs for speculative state management. Inferno is such a functional model construction framework and has significantly improved productivity in modeling a variety of sophisticated data speculation microarchitecture techniques.
12650891
PID controller design for output PDFs of stochastic systems using linear matrix inequalities
This paper presents a pseudo proportional-integral-derivative (PID) tracking control strategy for general non-Gaussian stochastic systems based on a linear B-spline model for the output probability density functions (PDFs). The objective is to control the conditional PDFs of the system output to follow a given target function. Different from existing methods, the control structure (i.e., the PID) is imposed before the output PDF controller design. Following the linear B-spline approximation on the measured output PDFs, the concerned problem is transferred into the tracking of given weights which correspond to the desired PDF. For systems with or without model uncertainties, it is shown that the solvability can be casted into a group of matrix inequalities. Furthermore, an improved controller design procedure based on the convex optimization is proposed which can guarantee the required tracking convergence with an enhanced robustness. Simulations are given to demonstrate the efficiency of the proposed approach and encouraging results have been obtained.
2365549
A framework for modeling and optimization of prescient instruction prefetch
This paper describes a framework for modeling macroscopic program behavior and applies it to optimizing prescient instruction prefetch -- novel technique that uses helper threads to improve single-threaded application performance by performing judicious and timely instruction prefetch. A helper thread is initiated when the main thread encounters a spawn point, and prefetches instructions starting at a distant target point. The target identifies a code region tending to incur I-cache misses that the main thread is likely to execute soon, even though intervening control flow may be unpredictable. The optimization of spawn-target pair selections is formulated by modeling program behavior as a Markov chain based on profile statistics. Execution paths are considered stochastic outcomes, and aspects of program behavior are summarized via path expression mappings. Mappings for computing reaching, and posteriori probability; path length mean, and variance; and expected path footprint are presented. These are used with Tarjan's fast path algorithm to efficiently estimate the benefit of spawn-target pair selections. Using this framework we propose a spawn-target pair selection algorithm for prescient instruction prefetch. This algorithm has been implemented, and evaluated for the Itanium Processor Family architecture. A limit study finds 4.8%to 17% speedups on an in-order simultaneous multithreading processor with eight contexts, over nextline and streaming I-prefetch for a set of benchmarks with high I-cache miss rates. The framework in this paper is potentially applicable to other thread speculation techniques.
781332
Minimum entropy control of nonlinear ARMA systems over a communication network
In this paper, the entropy concept has been utilized to characterize the uncertainty of the tracking error for nonlinear ARMA stochastic systems over a communication network, where time delays in the communication channels are of random nature. A recursive optimization solution has been developed. In addition, an alternative algorithm is also proposed based on the probability density function of the tracking error, which is estimated by a neural network. Finally, a simulation example is given to illustrate the efficiency and feasibility of the proposed approach.
661328
Physical experimentation with prefetching helper threads on Intel's hyper-threaded processors
Pre-execution techniques have received much attention as an effective way of prefetching cache blocks to tolerate the ever-increasing memory latency. A number of pre-execution techniques based on hardware, compiler, or both have been proposed and studied extensively by researchers. They report promising results on simulators that model a simultaneous multithreading (SMT) processor. We apply the helper threading idea on a real multithreaded machine, i.e., Intel Pentium 4 processor with hyper-threading technology, and show that indeed it can provide wall-clock speedup on real silicon. To achieve further performance improvements via helper threads, we investigate three helper threading scenarios that are driven by automated compiler infrastructure, and identify several key challenges and opportunities for novel hardware and software optimizations. Our study shows a program behavior changes dynamically during execution. In addition, the organizations of certain critical hardware structures in the hyper-threaded processors are either shared or partitioned in the multithreading mode and thus, the tradeoffs regarding resource contention can be intricate. Therefore, it is essential to judiciously invoke helper threads by adapting to the dynamic program behavior so that we can alleviate potential performance degradation due to resource contention. Moreover, since adapting to the dynamic behavior requires frequent thread synchronization, having light-weight thread synchronization mechanisms is important.