结构应变的无线监测及融合技术

针对结构应变监测,设计了一类无线应变传感装置,并对该装置采集的数据进行了数据融合处理.,介绍了无线应变传感器的硬件集成;描述了基于算术平均值的无线应变传感器信息融合方法;结合应变的无线测试实验,应用数据融合技术对测量数据加以分析处理.研究表明:所集成的无线应变传感器,安装简单、携带方便;采用了数据融合处理的应变信号更加准确;基于数据融合的无线应变传感器适合在现场测试中应用.     

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     

The who, what, why, where, and when of IT outsourcing

Outsourcing of IT functions has become so pervasive that IT managers and CIOs cannot ignore it. To complicate the matter, outsourcing to other countries has become increasingly popular. The advantages of this type of outsourcing include cost savings, 24/7 operation, and access to highly specialized skills. Yet a strategic alliance with a geographically and culturally remote partner presents its own unique challenges. Thus, IT professionals should not take the strategic questions of whether or not to outsource lightly, or avoid it. Rather, they can make such a decision by analyzing the responses to the following five key questions, what we call the five Ws: Who should outsource? What is outsourcing? Why outsource? Where should you outsource? When should you outsource? This article emerged from a focus group of CIOs conducted by the CIO Institute, a not-for-profit community of practice for CIOs in the Greater Philadelphia region.     

Enthalpies of formation of binary phases in the systems FeTi,FeZr, CoTi,CoZr, NiTi,and NiZr,by direct reaction calorimetry

The enthalpies of formation of the binary compounds in the systems AB where A is taken in the group VIII and B in the group IV A are measured by direct reaction calorimetry at high temperatures. Checks are made to ensure that the stoichiometry and the structure of each phase is obtained.     

Development of a three-dimensional,regional, coupled wave,current, and sediment-transport model

We are developing a three-dimensional numerical model that implements algorithms for sediment transport and evolution of bottom morphology in the coastal-circulation model Regional Ocean Modeling System (ROMS v3.0), and provides a two-way link between ROMS and the wave model Simulating Waves in the Nearshore (SWAN) via the Model-Coupling Toolkit. The coupled model is applicable for fluvial, estuarine, shelf, and nearshore (surfzone) environments. Three-dimensional radiation-stress terms have been included in the momentum equations, along with effects of a surface wave roller model. The sediment-transport algorithms are implemented for an unlimited number of user-defined non-cohesive sediment classes. Each class has attributes of grain diameter, density, settling velocity, critical stress threshold for erosion, and erodibility constant. Suspended-sediment transport in the water column is computed with the same advection–diffusion algorithm used for all passive tracers and an additional algorithm for vertical settling that is not limited by the CFL criterion. Erosion and deposition are based on flux formulations. A multi-level bed framework tracks the distribution of every size class in each layer and stores bulk properties including layer thickness, porosity, and mass, allowing computation of bed morphology and stratigraphy. Also tracked are bed-surface properties including active-layer thickness, ripple geometry, and bed roughness. Bedload transport is calculated for mobile sediment classes in the top layer. Bottom-boundary layer submodels parameterize wave–current interactions that enhance bottom stresses and thereby facilitate sediment transport and increase bottom drag, creating a feedback to the circulation. The model is demonstrated in a series of simple test cases and a realistic application in Massachusetts Bay.     

Coupled Transformation of Schemas, Documents, Queries, and Constraints

Coupled transformation occurs when multiple software artifacts must be transformed in such a way that they remain consistent with each other. For instance, when a database schema is adapted in the context of system maintenance, the persistent data residing in the system's database needs to be migrated to conform to the adapted schema. Also, queries embedded in the application code and any declared referential constraints must be adapted to take the schema changes into account. As another example, in XML-to-relational data mapping, a hierarchical XML Schema is mapped to a relational SQL schema with appropriate referential constraints, and the XML documents and queries are converted into relational data and relational queries. The 2LT project is aimed at providing a formal basis for coupled transformation. This formal basis is found in data refinement theory, point-free program calculation, and strategic term rewriting. We formalize the coupled transformation of a data type by an algebra of information-preserving data refinement steps, each witnessed by appropriate data conversion functions. Refinement steps are modeled by so-called two-level rewrite rules on type expressions that synthesize conversion functions between redex and reduct while rewriting. Strategy combinators are used to composed two-level rewrite rules into complete rewrite systems. Point-free program calculation is applied to optimized synthesize conversion function, to migrate queries, and to normalize data type constraints. In this paper, we provide an overview of the challenges met by the 2LT project and we give a sketch of the solutions offered.     

Quiescence, Fairness, Testing, and the Notion of Implementation

Two formalisms for concurrency, the Input/Output automaton model and the theory of testing, are compared and are shown to have common foundations. The relationship between the fair and quiescent preorders of I/O automata is investigated and the two preorders are shown to coincide subject to some restrictions. I/O automata are encoded into the theory of testing and the reversed preorder is shown to be equivalent to the quiescent preorder for strongly convergent, finitely branching I/O automata up to encoding. Conversely, a theory of testing is defined directly on I/O automata, and the new reversed preorder is shown to coincide with the quiescent preorder on strongly convergent, finitely branching I/O automata.     

3PSK、QPSK与OQPSK、UQPSK调制识别方法初探

近年来，卫星测控链路中大量使用了0QPSK、UQPSK的调制方式。从而，提出了如何区分这两种调制方式与BPSK、QPSK信号的课题。本文借助仿真工具MATIAB分析了这四种信号的二倍频、四倍频频谱特性，并对区分这四种信号的方法进行了初撂。     

BPSK、QPSK与OQPSK、UQPSK调制识别方法初探

近年来,卫星测控链路中大量使用了OQPSK、UQPSK的调制方式。从而,提出了如何区分这两种调制方式与BPSK、QPSK信号的课题。本文借助仿真工具MATLAB分析了这四种信号的二倍频、四倍频频谱特性,并对区分这四种信号的方法进行了初探。     

基于混沌系统的图像隐藏技术

为了在保证隐藏信息不可见性的条件下,尽可能地提高隐藏图像信息的安全性与抗干扰性,提出一种基于混沌系统的图像隐藏技术．先利用Arnold变换与混沌系统产生的混沌序列对待隐藏图像进行加密预处理;然后利用Logistic混沌系统与图像分存技术把结果图像进一步隐藏起来;最后应用评价指标对隐藏效果和安全性进行分析．实验结果表明,该算法具有良好的安全性和隐藏效果．     

User Experience of On-Screen Interaction Techniques: An Experimental Investigation of Clicking,Sliding, Zooming,Hovering, Dragging,and Flipping

From scrolling and clicking to dragging, flipping, sliding, hovering, and zooming, the wide array of interaction techniques has vastly expanded the range of user actions on an interface. Each of these interaction techniques affords a distinct action. But do these techniques differ in their ability to engage users and contribute to their user experience? Furthermore, do they affect how users view the content and how much they learn from it? We address these questions via two between-subjects laboratory experiments. Study 1 (N = 128) investigated the relative effects of six on-screen interaction techniques (click-to-download, drag, mouseover, slide, zoom, and 3D carousel) on users' assessment of—as well as their engagement with—an informational website. The site for each condition was identical in content and design, except for the interaction technique used, so that we could isolate the effects of each technique on various cognitive, attitudinal and behavioral outcomes. Study 2 (N = 127) examined the relative effects of four combinations of interaction techniques (slide+click, slide+mouseover, drag+mouseover, and drag+zoom) on the same dependent variables. Data from Study 1 suggest that although the 3D carousel generates more user action, the slide is better at aiding memory. The zoom-in/out tool was the least favored, whereas the mouseover feature fostered greater engagement among power users. Findings from Study 2, which was conducted with a different content domain, replicated the positive effects of slide and negative effects of drag in influencing user experience. Path analyses, using structural equation modeling, revealed the importance of users' assessment of the interface (perceived levels of natural mapping, intuitiveness, and ease of use), which can have significant consequences for user engagement as well as resulting attitudes and behavioral outcomes. Design insights, theories, and techniques to test and capture user experience are discussed.     

The Influence of the Avatar on Online Perceptions of Anthropomorphism, Androgyny, Credibility, Homophily, and Attraction

It has become increasingly common for Web sites and computer media to provide computer generated visual images, called avatars, to represent users and bots during online interactions. In this study, participants (N = 255) evaluated a series of avatars in a static context in terms of their androgyny, anthropomorphism, credibility, homophily, attraction, and the likelihood they would choose them during an interaction. The responses to the images were consistent with what would be predicted by uncertainty reduction theory. The results show that the masculinity or femininity (lack of androgyny) of an avatar, as well as anthropomorphism, significantly influence perceptions of avatars. Further, more anthropomorphic avatars were perceived to be more attractive and credible, and people were more likely to choose to be represented by them. Participants reported masculine avatars as less attractive than feminine avatars, and most people reported a preference for human avatars that matched their gender. Practical and theoretical implications of these results for users, designers, and researchers of avatars are discussed.     

Four dimensions of significance: Tradition, method, theory, originality

In this article, I reflect on four dimensions of assessing the significance of research in the computers and composition field: tradition, method, theory, and originality. Considering these four key concepts as topoi will help our community define, explain, and predict how future research will significantly contribute to teaching wisely and to writing well with technology.     

Structural synthesis of frame reinforced,submersible, circular,cylindrical hulls

This paper describes a mathematical programming procedure for the automated optimal structural synthesis of frame stiffened, cylindrical shells. For a specified set of design parameters such as external pressure, shell radius and length and material properties, the method generates those values of the design variables that produce a minimum weight design. The skin, frame web and frame flange thicknesses and the flange width are treated as continuous variables. Frame spacing is considered a discrete variable. Constraint equations control local and general shell and frame instability and yield. Limits may be placed on the variable values, and certain geometric or space constraints can be applied. The mixed (continuous and discrete nonlinear programming problem is solved by a combination of a discrete ‘Golden Search’ for the optimal number of frames and the ‘Direct Search Design Algorithm’ which provides the optimum values of the continuous variables.     

A theoretical comparison of batch-mode, on-line, cyclic, andalmost-cyclic learning

We study and compare different neural network learning strategies: batch-mode learning, online learning, cyclic learning, and almost-cyclic learning. Incremental learning strategies require less storage capacity than batch-mode learning. However, due to the arbitrariness in the presentation order of the training patterns, incremental learning is a stochastic process; whereas batch-mode learning is deterministic. In zeroth order, i.e., as the learning parameter eta tends to zero, all learning strategies approximate the same ordinary differential equation for convenience referred to as the "ideal behavior". Using stochastic methods valid for small learning parameters eta, we derive differential equations describing the evolution of the lowest-order deviations from this ideal behavior. We compute how the asymptotic misadjustment, measuring the average asymptotic distance from a stable fixed point of the ideal behavior, scales as a function of the learning parameter and the number of training patterns. Knowing the asymptotic misadjustment, we calculate the typical number of learning steps necessary to generate a weight within order epsilon of this fixed point, both with fixed and time-dependent learning parameters. We conclude that almost-cyclic learning (learning with random cycles) is a better alternative for batch-mode learning than cyclic learning (learning with a fixed cycle).