Coding, analysis, interpretation, and recognition of facialexpressions

We describe a computer vision system for observing facial motion by using an optimal estimation optical flow method coupled with geometric, physical and motion-based dynamic models describing the facial structure. Our method produces a reliable parametric representation of the face's independent muscle action groups, as well as an accurate estimate of facial motion. Previous efforts at analysis of facial expression have been based on the facial action coding system (FACS), a representation developed in order to allow human psychologists to code expression from static pictures. To avoid use of this heuristic coding scheme, we have used our computer vision system to probabilistically characterize facial motion and muscle activation in an experimental population, thus deriving a new, more accurate, representation of human facial expressions that we call FACS+. Finally, we show how this method can be used for coding, analysis, interpretation, and recognition of facial expressions     

Contract signing, optimism, and advantage

A contract signing protocol lets two parties exchange digital signatures on a pre-agreed text. Optimistic contract signing protocols enable the signers to do so without invoking a trusted third party. However, an adjudicating third party remains available should one or both signers seek timely resolution. We analyze optimistic contract signing protocols using a game-theoretic approach and prove a fundamental impossibility result: in any fair, optimistic, timely protocol, an optimistic player yields an advantage to the opponent. The proof relies on a careful characterization of optimistic play that postpones communication to the third party.     

Turing machines, transition systems, and interaction

This paper presents persistent Turing machines (PTMs), a new way of interpreting Turing-machine computation, based on dynamic stream semantics. A PTM is a Turing machine that performs an infinite sequence of “normal” Turing machine computations, where each such computation starts when the PTM reads an input from its input tape and ends when the PTM produces an output on its output tape. The PTM has an additional worktape, which retains its content from one computation to the next; this is what we mean by persistence.A number of results are presented for this model, including a proof that the class of PTMs is isomorphic to a general class of effective transition systems called interactive transition systems; and a proof that PTMs without persistence (amnesic PTMs) are less expressive than PTMs. As an analogue of the Church-Turing hypothesis which relates Turing machines to algorithmic computation, it is hypothesized that PTMs capture the intuitive notion of sequential interactive computation.     

Digital parallelism, perpendicularity, and rectangles

The slope of digital line segments is defined and an algorithm to evaluate it is presented. Parallelism and perpendicularity of two digital line segments are also defined. Finally, rectangular digital regions are defined and characterized, and an algorithm that determines whether or not a given digital region is a digital rectangle is presented.     

Context, situations, and design agents

The terms “context” and “situation” are often used interchangeably or to denote a variety of concepts. This paper aims to show that these are two different but related concepts and it reifies their difference within the framework of design agents. The external world of an agent is described as the aggregation of all entities that the agent could possibly sense or effect, where context is from its external world that an agent interacts with and is aware of. The interpreted world of an agent is described in terms of the experiences of that agent, where situations are processes that direct how interactive experiences proceed. Situations determine what part of the external world are in the current context, and situations influence interaction and so influence what and how common ground is acquired.     

Recipes,Algorithms, and Programs

In the technical literature of computer science, the concept of an effective procedure is closely associated with the notion of an instruction that precisely specifies an action. Turing machine instructions are held up as providing paragons of instructions that "precisely describe" or "well define" the actions they prescribe. Numerical algorithms and computer programs are judged effective just insofar as they are thought to be translatable into Turing machine programs. Nontechnical procedures (e.g., recipes, methods) are summarily dismissed as ineffective on the grounds that their instructions lack the requisite precision. But despite the pivotal role played by the notion of a precisely specified instruction in classifying procedures as effective and ineffective, little attention has been paid to the manner in which instructions "precisely specify" the actions they prescribe. It is the purpose of this paper to remedy this defect. The results are startling. The reputed exemplary precision of Turing machine instructions turns out to be a myth. Indeed, the most precise specifications of action are provided not by the procedures of theoretical computer science and mathematics (algorithms) but rather by the nontechnical procedures of everyday life. I close with a discussion of some of the rumifications of these conclusions for understanding and designing concrete computers and their programming languages.     

Matching, linear systems, and the ball and beam

A recent approach to the control of underactuated systems is to look for control laws which will induce some specified structure on the closed loop system. In this paper, we describe one matching condition and an approach for finding all control laws that fit the condition. After an analysis of the resulting control laws for linear systems, we present the results from an experiment on a nonlinear ball and beam system.     

人工系统中数据–因素–算力–算法作用及相互关系研究

目前的研究认为人工智能的核心是数据、算法和算力,但因素在形成人工智能系统过程中是必不可少的。论文针对人工系统中的数据、算力、算法和因素的各自作用,及其相互关系进行了探讨和论证。从人工系统的内涵出发,描述人工系统的发展过程,认为目前和今后的人工系统必将具有人工智能特征,而实现人工系统要充分考虑上述四方面的相互作用。研究结果表明:数据是人工系统辨识因素的基础,也是形成算法的基础;因素是人工系统控制自然系统的方法及算法所需变量;算法体现了因素与数据关系,可描述人工系统结构;算力是解算算法的能力,也需考虑数据和因素的特征。因此因素在人工系统建立过程中与数据、算法和算力具有相同的重要性。它们具有明显的作用关系,且普遍存在于各个学科,是形成各学科理论基础体系的关键。     

Logical omniscience, semantics, and models of belief

Logical omniscience may be described (roughly) as the state of affairs in which an agent explicitly believes anything which is logically entailed by that agent's beliefs. It is widely agreed that humans are not logically omniscient, and that an adequate formal model of belief, coupled with a correct semantic theory, would not entail logical omniscience. Recently, two prominent models of belief have emerged which purport both to avoid logical omniscience and to provide an intuitively appealing semantics. The first of these models is due to Levesque (1984 b ); the second to Fagin and Halpem (1985). It is argued herein that each of these models faces serious difficulties. Detailed criticisms are presented for each model, and a computationally oriented theory of intensions is presented which provides the foundation for a new formal model of belief. This formal model is presented in a decidable subset of first-order logic and is shown to provide a solution to the general problem of logical omniscience. The model provides for the possibility of belief revision and places no a priori restrictions upon an agent's representation language.     

Mandalas,screws, pears,and Klein bottles

The goal of this article is to present an informal introduction and tutorial on the production of aesthetically pleasing solid models. The article is intended for the nonmathematical reader interested in computer art. Simple generating formulas and recipes are included.     

Sparse Grids, Adaptivity, and Symmetry

Sparse grid methods represent a powerful and efficient technique for the representation and approximation of functions and particularly the solutions of partial differential equations in moderately high space dimensions. To extend the approach to truly high-dimensional problems as they arise in quantum chemistry, an additional property has to be brought into play, the symmetry or antisymmetry of the functions sought there. In the present article, an adaptive sparse grid refinement scheme is developed that takes full advantage of such symmetry properties and for which the amount of work and storage remains strictly proportional to the number of degrees of freedom. To overcome the problems with the approximation of the inherently complex antisymmetric functions, augmented sparse grid spaces are proposed.     

Design, Simulation, Fabrication, and Characterization of a Digital Variable Optical Attenuator

In this paper, we present the design, simulation, fabrication, and some measurement and characterization of a novel 16-bit digital variable optical attenuator (VOA) that attenuates by switching individual mirror of an array as an attempt to achieve input voltage variation independence and output linearization. The design was aided by a simulation package that features coupled electrostatic and mechanical solver. The mirror array spans an area of 1500$,times,$1500$mu m^2$and contains 16 equal-length rectangular micromirrors. Each mirror is suspended by two torsion beams. Experiments on beam design and width variations are conducted. Assuming Gaussian distribution, the mirror widths computed by an iteration algorithm vary from about 40 to 250$mu m$. Based on silicon-on-insulator (SOI) technology, two fabrication schemes to open the backside optical entrance were investigated. A hydrofluoric (HF) acid vapor-phase-etching (VPE) setup built to release the microstructure anhydrously is the key to achieve high yield especially for fragile components. Surface flatness, resonance frequencies, and tilt angles of selected mirrors were characterized. Quartz chips patterned with aluminum electrodes and 10$mu m$-high SU8 spacer columns were fabricated and assembled to corresponding device chips. Optical performance adversely affected by mirror bending is believed to originate from the intrinsic stress of the SOI wafer. 1271     

Actors,actions, and initiative in normative system specification

The logic of norms, called deontic logic, has been used to specify normative constraints for information systems. For example, one can specify in deontic logic the constraints that a book borrowed from a library should be returned within three weeks, and that if it is not returned, the library should send a reminder. Thus, the notion of obligation to perform an action arises naturally in system specification. Intuitively, deontic logic presupposes the concept of anactor who undertakes actions and is responsible for fulfilling obligations. However, the concept of an actor has not been formalized until now in deontic logic. We present a formalization in dynamic logic, which allows us to express the actor who initiates actions or choices. This is then combined with a formalization, presented earlier, of deontic logic in dynamic logic, which allows us to specify obligations, permissions, and prohibitions to perform an action. The addition of actors allows us to expresswho has the responsibility to perform an action. In addition to the application of the concept of an actor in deontic logic, we discuss two other applications of actors. First, we show how to generalize an approach taken up by De Nicola and Hennessy, who eliminate from CCS in favor of internal and external choice. We show that our generalization allows a more accurate specification of system behavior than is possible without it. Second, we show that actors can be used to resolve a long-standing paradox of deontic logic, called the paradox of free-choice permission. Towards the end of the paper, we discuss whether the concept of an actor can be combined with that of an object to formalize the concept of active objects.     

Belief,awareness, and limited reasoning

Several new logics for belief and knowledge are introduced and studied, all of which have the property that agents are not logically omniscient. In particular, in these logics, the set of beliefs of an agent does not necessarily contain all valid formulas. Thus, these logics are more suitable than traditional logics for modelling beliefs of humans (or machines) with limited reasoning capabilities. Our first logic is essentially an extension of Levesque's logic of implicit and explicit belief, where we extend to allow multiple agents and higher-level belief (i.e., beliefs about beliefs). Our second logic deals explicitly with “awareness,” where, roughly speaking, it is necessary to be aware of a concept before one can have beliefs about it. Our third logic gives a model of “local reasoning,” where an agent is viewed as a “society of minds,” each with its own cluster of beliefs, which may contradict each other.     

Microcomputers, Slotcars, and Education

Working models interfaced to microcomputers provide an inexpensive way of simulating real-world situations.     

Requirements engineering for trust management: model, methodology, and reasoning

A number of recent proposals aim to incorporate security engineering into mainstream software engineering. Yet, capturing trust and security requirements at an organizational level, as opposed to an IT system level, and mapping these into security and trust management policies is still an open problem. This paper proposes a set of concepts founded on the notions of ownership, permission, and trust and intended for requirements modeling. It also extends Tropos, an agent-oriented software engineering methodology, to support security requirements engineering. These concepts are formalized and are shown to support the automatic verification of security and trust requirements using Datalog. To make the discussion more concrete, we illustrate the proposal with a Health Care case study.This work is an expanded and revised version of [19,20].     

Fuzzy queries, search, and decision support system

 The process of ranking (scoring) has been used to make billions of financing decisions each year serving an industry worth hundreds of billion of dollars. To a lesser extent, ranking has also been used to process hundreds of millions of applications by U.S. Universities resulting in over 15 million college admissions in the year 2000 for a total revenue of over $250 billion. College admissions are expected to reach over 17 million by the year 2010 for total revenue of over $280 billion. In this paper, we will introduce fuzzy query and fuzzy aggregation as an alternative for ranking and predicting the risk for credit scoring and university admissions, which currently utilize an imprecise and subjective process. In addition we will introduce the BISC Decision Support System. The main key features of the BISC Decision Support System for the internet applications are (1) to use intelligently the vast amounts of important data in organizations in an optimum way as a decision support system and (2) to share intelligently and securely company's data internally and with business partners and customers that can be process quickly by end users.     

Monitoring, Checking, and Steering of Real-Time Systems

The MaC system has been developed to provide assurance that a target program is running correctly with respect to formal requirements specification. This is achieved by monitoring and checking the execution of the target program at run-time. MaC bridges the gap between formal verification, which ensures the correctness of a design rather than an implementation, and testing, which only partially validates an implementation. One weakness of the MaC system is that it can detect property violations but cannot provide any feedback to the running system. To remedy this weakness, the MaC system has been extended with a feedback capability. The resulting system is called MaCS (Monitoring and Checking with Steering). The feedback component uses the information collected during monitoring and checking to steer the application back to a safe state after an error occurs. We present a case study where MaCS is used in a control system that keeps an inverted pendulum upright. MaCS detects faults in controllers and performs dynamic reconfiguration of the control system using steering.     

Data provenance in SOA: security, reliability, and integrity

Due to the dynamic nature, such as services composition and evaluation, it is critical for a Service-Oriented Architecture (SOA) system to consider its data provenance, which concerns security, reliability, and integrity of data as they are being routed in the system. In a traditional software system, one focuses on the software itself to determine the security, reliability, and integrity of the software. In an SOA system, however, one also needs to consider origins and routes of data and their impact, i.e., data provenance. This paper first analyzes the unique nature and characteristics of data provenance in an SOA system, particularly related to data security, reliability, and integrity. Then it proposes a new framework for data provenance analysis in an SOA system. Finally, this paper uses an example which illustrates these techniques.