共查询到20条相似文献,搜索用时 31 毫秒
1.
Margarita Guenther Gerald Gerlach Thomas Wallmersperger 《Microsystem Technologies》2010,16(5):703-715
Already 8 years ago, the usage of piezoresistive sensors for chemical measurands was proposed at the Solid State Electronics
Laboratory of the Dresden University of Technology. Adding functionalised polymer coating which shows swelling due to chemical
or biological values leads to a similar deflection of the thin silicon bending plate like for pressure sensors. The application
of “stimuli-responsive” or “smart” cross-linked gels in chemical sensors is based on their ability to a phase transition under
the influence of external excitations (pH, concentration of additives in water, temperature). Combining a “smart” hydrogel
and a micro fabricated pressure sensor chip allows to continuously monitor the analyte-dependent swelling of a hydrogel and
hence the analyte concentration in ambient aqueous solutions. The sensitivity of hydrogels with regard to the concentration
of such additives as H+-ions (pH sensor), transition-metal ions, salts, organic solvents and proteins in water was investigated. 相似文献
2.
Christian Bassac Bruno Mery Christian Retoré 《Journal of Logic, Language and Information》2010,19(2):229-245
After a quick overview of the field of study known as “Lexical Semantics”, where we advocate the need of accessing additional
information besides syntax and Montague-style semantics at the lexical level in order to complete the full analysis of an
utterance, we summarize the current formulations of a well-known theory of that field. We then propose and justify our own
model of the Generative Lexicon Theory, based upon a variation of classical compositional semantics, and outline its formalization.
Additionally, we discuss the theoretical place of informational, knowledge-related data supposed to exist within the lexicon
as well as within discourse and other linguistic constructs. The formalization of the structure of natural language utterances
around a surface form (phenogrammatics), a deep structure (tectogrammatics) and the meaning thereof as a logical form (semantics)
has developed from the original theories of Curry and Montague to form coherent, type-driven models. Most of these new theories
rely upon variations of the compositional analysis of the sentence: from pheno to tectogrammatics, and then to semantics.
Our contribution to this work aims at giving such a model a means to overcome the problems posed by polysemous lexical units
during the semantical analysis of the tectogrammatical form. Building upon an assumed “deep structure”, we formalize parts
of Pustejovsky’s Generative Lexicon Theory, linguistically motivated in Pustejovsky (The generative lexicon, MIT Press, Cambridge,
MA, 1995), in a pre-processing of the semantics of the sentence. The mechanisms of Lexical Semantics we propose are an additional
layer of classical Montague compositional semantics, and, as such, integrate smoothly within such an analysis; we proceed
by converting the lexical data to modifiers of the logical form. This treatment of Lexical Semantics furthermore induces us
to think that some sort of non-evident background knowledge of the common use of words is necessary to perform a correct semantic
analysis of an utterance. This “commonsense metaphysics” would therefore not be strictly confined to pragmatics, as is often
assumed. 相似文献
3.
In this paper, a facial animation system is proposed for capturing both geometrical information and illumination changes of surface details, called expression details, from video clips simultaneously, and the capture ddata can be widely applied to different 2D face images and 3D face models. While tracking the geometric data, we record the expression details by ratio images. For 2D facial animation synthesis, these ratio images are used to generate dynamic textures. Because a ratio image is obtained via dividing colors of an expressive face by those of a neutral face, pixels with ratio value smaller than one are where a wrinkle or crease appears. The refore, thegradients of the ratio value at each pixel in ratio images are regarded as changes of a face surface, and original normals on the surface can be adjusted according to these gradients. Based on this idea, we can convert the ratio images into a sequence of normal maps and then apply them to animated 3D model rendering. With the expression detail mapping, the resulted facial animations are more life-like and more expressive. 相似文献
4.
The Requirements-to-Design-to-Code (R2D2C) project of NASA’s Software Engineering Laboratory is based on inferring a formal
specification expressed in Communicating Sequential Processes (CSP) from system requirements supplied in the form of CSP traces.
The traces, in turn, are to be derived from scenarios, a user-friendly medium used to describe the required behavior of computer
systems under development. An extensive survey of the “scenario” concept and an overview of scenario-based approaches to system
engineering are presented. This work, called Mise en Scene, defines a new scenario medium (scenario notation language, SNL)
suitable for control-dominated systems, coupled with a two-stage process for automatic translation of scenarios to a new trace
medium (trace notation language, TNL), which encompasses CSP traces. Notes on progress toward a “smart” scenario authoring
tool are provided, as well as a detailed case study.
This work was originally presented at the Software Engineering Workshop (SEW-31) in March 2007. It was supported by research
grants from Canada’s Natural Sciences and Engineering Research Council (NSERC). 相似文献
5.
Tomoko Itao Satoshi Tanaka Tatsuya Suda Atsushi Yamamoto 《International Journal on Digital Libraries》2006,6(3):270-279
We describe a mechanism called SpaceGlue for adaptively locating services based on the preferences and locations of users
in a distributed and dynamic network environment. In SpaceGlue, services are bound to physical locations, and a mobile user
accesses local services depending on the current space he/she is visiting. SpaceGlue dynamically identifies the relationships
between different spaces and links or “glues” spaces together depending on how previous users moved among them and used those
services. Once spaces have been glued, users receive a recommendation of remote services (i.e., services provided in a remote
space) reflecting the preferences of the crowd of users visiting the area. The strengths of bonds are implicitly evaluated
by users and adjusted by the system on the basis of their evaluation. SpaceGlue is an alternative to existing schemes such
as data mining and recommendation systems and it is suitable for distributed and dynamic environments. The bonding algorithm
for SpaceGlue incrementally computes the relationships or “bonds” between different spaces in a distributed way. We implemented
SpaceGlue using a distributed network application platform Ja-Net and evaluated it by simulation to show that it adaptively
locates services reflecting trends in user preferences. By using “Mutual Information (MI)” and “F-measure” as measures to indicate the level of such trends and the accuracy of service recommendation, the simulation results
showed that (1) in SpaceGlue, the F-measure increases depending on the level of MI (i.e., the more significant the trends, the greater the F-measure values), (2) SpaceGlue achives better precision and F-measure than “Flooding case (i.e., every service information is broadcast to everybody)” and “No glue case” by narrowing
appropriate partners to send recommendations based on bonds, and (3) SpaceGlue achieves better F-measure with large number of spaces and users than other cases (i.e., “flooding” and “no glue”).
Tomoko Itao is an alumna of NTT Network Innovation Laboratories 相似文献
6.
A general formal model for trust in dynamic networks is presented. The model is based on the trust structures of Carbone,
Nielsen and Sassone: a domain theoretic generalisation of Weeks’ framework for credential based trust management systems,
e.g., KeyNote and SPKI. Collections of mutually referring trust policies (so-called “webs” of trust) are given a precise meaning
in terms of an abstract domain-theoretic semantics. A complementary concrete operational semantics is provided using the well-known
I/O-automaton model. The operational semantics is proved to adhere to the abstract semantics, effectively providing a distributed
algorithm allowing principals to compute the meaning of a “web” of trust policies. Several techniques allowing sound and efficient
distributed approximation of the abstract semantics are presented and proved correct.
BRICS: Basic Research in Computer Science (www.brics.dk) funded by the Panish National Research Foundation. 相似文献
7.
Much of the ongoing research in ubiquitous computing has concentrated on providing context information, e.g. location information,
to the level of services and applications. Typically, mobile clients obtain location information from their environment which
is used to provide “locally optimal” services. In contrast, it may be of interest to obtain information about the current
context a mobile user or device is in, from a client somewhere on the Web, i.e. to use the mobile device as an information
provider for Internet clients.
As an instance of such services we propose the metaphor of a “location-aware” Web homepage of mobile users providing information
about, e.g. the current location a mobile user is at. Requesting this homepage can be as easy as typing a URL containing the
mobile user's phone number such ashttp://mhp.net/+49123456789 in an off-the-shelf browser. The homepage is dynamically constructed as Web users access it and it can be configured in various
ways that are controlled by the mobile user. We present the architecture and implementation and discuss issues around this
example of “inverse” ubiquitous computing. 相似文献
8.
Current investigations on visual information retrieval are generally content-based methods. The significant difference between similarity in low-level features and similarity in high-level semantic meanings is still a major challenge in the area of image retrieval. In this work, a scheme for constructing visual ontology to retrieve art images is proposed. The proposed ontology describes images in various aspects, including type & style, objects and global perceptual effects. Concepts in the ontology could be automatically derived. Various art image classification methods are employed based on low-level image features. Non-objective semantics are introduced, and how to express these semantics is given. The proposed ontology scheme could make users more naturally find visual information and thus narrows the “semantic gap”. Experimental implementation demonstrates its good potential for retrieving art images in a human-centered manner. 相似文献
9.
Handling message semantics with Generic Broadcast protocols 总被引:1,自引:0,他引:1
Summary. Message ordering is a fundamental abstraction in distributed systems. However, ordering guarantees are usually purely “syntactic,”
that is, message “semantics” is not taken into consideration despite the fact that in several cases semantic information about
messages could be exploited to avoid ordering messages unnecessarily. In this paper we define the Generic Broadcast problem, which orders messages only if needed, based on the semantics of the messages. The semantic information about messages
is introduced by conflict relations. We show that Reliable Broadcast and Atomic Broadcast are special instances of Generic
Broadcast. The paper also presents two algorithms that solve Generic Broadcast.
Received: August 2000 / Accepted: August 2001 相似文献
10.
A. F. Newell P. Gregor M. Morgan G. Pullin C. Macaulay 《Universal Access in the Information Society》2011,10(3):235-243
Although “User-Centred”, “Participatory”, and other similar design approaches have proved to be very valuable for mainstream
design, their principles are more difficult to apply successfully when the user group contains, or is composed of, older and/or
disabled users. In the field of design for older and disabled people, the “Universal Design”, “Inclusive Design” and “Design
for All” movements have encouraged designers to extend their design briefs to include older and disabled people. The downside
of these approaches is that they can tend to encourage designers to follow a traditional design path to produce a prototype
design, and only then investigate how to modify their interfaces and systems to cope with older and/or disabled users. This
can lead to an inefficient design process and sometimes an inappropriate design, which may be “accessible” to people with
disabilities, but in practice unusable. This paper reviews the concept that the authors have called “User-Sensitive Inclusive
Design”, which suggests a different approach to designing for marginalised groups of people. Rather than suggesting that designers
rely on standards and guidelines, it is suggested that designers need to develop a real empathy with their user groups. A
number of ways to achieve this are recommended, including the use of ethnography and techniques derived from professional
theatre both for requirements gathering and for improving designers’ empathy for marginalised groups of users, such as older
and disabled people. 相似文献
11.
V. Loia S. Senatore M. I. Sessa 《Soft Computing - A Fusion of Foundations, Methodologies and Applications》2002,6(5):348-356
Bots, or software agents are programs designed to perform tasks autonomously. Mailbots attempt to provide useful functions
about electronic mail (E-mail) service such as filtering information, gathering information, and scheduling. With Internet
use continuing to explode, the information overload is growing so fast that the same virtues that made E-mail so popular are
now becoming a negative technologic “boomerang” (see the volume of junk or spam mail). Industrial as well as academic research
has faced this problem in terms of automated filtering methods in order to distinguish legtimate E-mail from spamming. Here
we describe an alternative approach: our mailbot is skilled to find “appropriate” destination of the message triggering a
spidering process on an Intranet-based network. The spidering performs a distributed, mobile computation via pervasive agents:
by applying a similarity-based reasoning on designed users resources the agents are able to deduct if the contacted user may
be interested or not in receiving the E-mail. The overall architecture is implemented in Java using the basic issues of Internet
protocol. 相似文献
12.
It is argued that “human-centredness” will be an important characteristic of systems that learn tasks from human users, as
the difficulties in inductive inference rule out learning without human assistance. The aim of “programming by example” is
to create systems that learn how to perform tasks from their human users by being shown examples of what is to be done. Just
as the user creates a learning environment for the system, so the system provides a teaching opportunity for the user, and
emphasis is placed as much on facilitating successful teaching as on incorporating techniques of machine learning. If systems
can “learn” repetitive tasks, their users will have the power to decide for themselves which parts of their jobs should be
automated, and teach the system how to do them — reducing their dependence on intermediaries such as system designers and
programmers.
This paper presents principles for programming by example derived from experience in creating four prototype learners: for
technical drawing, text editing, office tasks, and robot assembly. A teaching metaphor (a) enables the user to demonstrate
a task by performing it manually, (b) helps to explain the learner's limited capabilities in terms of a persona, and (c) allows
users to attribute intentionality. Tasks are represented procedurally, and augmented with constraints. Suitable mechanisms
for attention focusing are necessary in order to control inductive search. Hidden features of a task should be made explicit
so that the learner need not embark on the huge search entailed by hypothesizing missing steps. 相似文献
13.
G. G. Byelonogov R. S. Gilyarevskii 《Automatic Documentation and Mathematical Linguistics》2010,44(1):38-43
This paper addresses the epistemological status of the concept of “information,” the central concept in the discipline of
informatics. Emphasis is made of its “human” origin. The viewpoint of some researchers that information is an attribute of
matter ad initium that is contained in all objects of both living and inanimate nature is dismissed. 相似文献
14.
Gary Demos 《The Visual computer》2005,21(12):961-978
Gary Demos discovered computer graphics while hearing a computer-generated film presentation at CalTech in 1970 by John Whitney
Sr. Gary then began working under the direction of Ivan Sutherland in Utah to develop early computer graphics hardware and
software. In 1974 Gary and John Whitney Jr. started the “Motion Picture Project” at Information International to produce computer
generated simulated scenes for movies (Futureworld, Looker, and Tron) and commercials. These early computer-generated visuals
were quite challenging given the level of software and hardware technology available in the 1970’s. In 1981 Gary and John
left Information International to form Digital Productions, where they produced effects for the movies Last Starfighter and
“2010”, which were both released in 1984. Digital Productions used the Cray XMP computer, together with the Digital Film Printer
that they had developed at Information International. Following a hostile takeover by Omibus of Digital Productions in 1986,
Whitney/Demos Productions was formed, using a Thinking Machine parallel computer. This paper describes the technical challenges
and achievements of this early visual computing. 相似文献
15.
Giuseppe Riva 《Virtual Reality》2009,13(3):159-169
The International Society of Presence Research, defines “presence” (a shortened version of the term “telepresence”) as a “psychological
state in which even though part or all of an individual’s current experience is generated by and/or filtered through human-made
technology, part or all of the individual’s perception fails to accurately acknowledge the role of the technology in the experience”
(ISPR 2000, The concept of presence: explication statement. Accessed 15 Jan 2009). In this article, we will draw on the recent outcomes of cognitive sciences to offer a broader definition
of presence, not related to technology only. Specifically, presence is described here as a core neuropsychological phenomenon
whose goal is to produce a sense of agency and control: subjects are “present” if they are able to enact in an external world
their intentions. This framework suggests that any environment, virtual or real, does not provide undifferentiated information,
ready-made objects equal for everyone. It offers different opportunities and produces presence according to its ability in
supporting the users and their intentions. The possible consequences of this approach for the development of presence-inducing
virtual environments are also discussed. 相似文献
16.
Aliaksandr Birukou Enrico Blanzieri Paolo Giorgini 《Autonomous Agents and Multi-Agent Systems》2012,24(1):141-174
For people with non-ordinary interests, it is hard to search for information on the Internet because search engines are impersonalized
and are more focused on “average” individuals with “standard” preferences. In order to improve web search for a community
of people with similar but specific interests, we propose to use the implicit knowledge contained in the search behavior of
groups of users. We developed a multi-agent recommendation system called Implicit, which supports web search for groups or
communities of people. In Implicit, agents observe behavior of their users to learn about the “culture” of the community with
specific interests. They facilitate sharing of knowledge about relevant links within the community by means of recommendations.
The agents also recommend contacts, i.e., who in the community is the right person to ask for a specific topic. Experimental
evaluation shows that Implicit improves the quality of the web search in terms of precision and recall. 相似文献
17.
This paper discusses a study on the mechanism of self-organization. A global order is organized by the simple and locally
coordinated actions of autonomous agents using only local information, so complex or globally coordinated actions which use
global communication and high-level strategies are not necessary. The fundamental factors for establishing a global order
using self-organization are a “dissipative structure,” an “autocatalysis mechanism,” and “intentional fluctuations.” If an
environment where there are agents has a dissipative structure and those agents have some sort of autocatalysis and intentional
fluctuation mechanisms within themselves, it is possible to form a global order for them using only their simple and locally
coordinated actions. “The blind-hunger dilemma” is used as an example to simulate the self-organization and coordinated actions
of agents. In this simulation environment, there are many ant-like agents which must get energy. However, there is only one
small energy supply base, so either an efficient method or the coordinated actions of agents is needed. As a result, the agents
using our approach could move and get energy more efficiently than agents using conventional coordination mechanisms involving
global communication and high-level strategies.
Real World Computing Partnership
This work was presented, in part, at the Second International Symposium on Artificial Life and Robotics, Oita, Japan, February
18–20, 1997 相似文献
18.
Logic knowledge based systems (LKBS) containing at most one form of default negation and explicit (or “classical”) negation
have been studied in the literature. In this paper we describe a class of LKBS containing multiple forms of default negation
in addition to explicit negation. We define a semantics for these systems in terms of the well‐founded semantics defined by
Van Gelder et al. (1988) and the stable semantics introduced by Gelfond and Lifschitz (1988) and later extended to the 3‐valued
case by Przymusinski (1991). We investigate properties of the new combined semantics and calculate the computational complexity
of three main reasoning tasks for this semantics, namely existence of models, skeptical and credulous reasoning. An effective
procedure to construct the collection of models characterizing the semantics of such a system is given. Applications to knowledge
representation and knowledge base merging are presented.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
19.
Damien Palacio Guillaume Cabanac Christian Sallaberry Gilles Hubert 《International Journal on Digital Libraries》2010,11(2):91-109
Search engines for Digital Libraries allow users to retrieve documents according to their contents. They process documents
without differentiating the manifold aspects of information. Spatial and temporal dimensions are particularly dismissed. These
dimensions are, however, of great interest for users of search engines targeting either the Web or specialized Digital Libraries.
Recent studies reported that nearly 20% queries convey spatial and temporal information in addition to topical information.
These three dimensions were referred to as parts of “geographic information.” In the literature, search engines handling those
dimensions are called “Geographic Information Retrieval (GIR) systems.” Although several initiatives for evaluating GIR systems
were undertaken, none was concerned with evaluating these three dimensions altogether. In this article, we address this issue
by designing an evaluation framework, usefulness of which is highlighted through a case study involving a test collection
and a GIR system. This framework allowed the comparison of our GIR system to state-of-the-art topical approaches. We also
performed experiments for measuring performance improvement stemming from each dimension or their combination. We show that
combining the three dimensions yields improvement in effectiveness (+73.9%) over a common topical baseline. Moreover, rather
than conveying redundancy, the three dimensions complement each other. 相似文献
20.
Design and analysis of a video-on-demand server 总被引:6,自引:0,他引:6
The availability of high-speed networks, fast computers and improved storage technology is stimulating interest in the development
of video on-demand services that provide facilities similar to a video cassette player (VCP). In this paper, we present a
design of a video-on-demand (VOD) server, capable of supporting a large number of video requests with complete functionality
of a remote control (as used in VCPs), for each request. In the proposed design, we have used an interleaved storage method
with constrained allocation of video and audio blocks on the disk to provide continuous retrieval. Our storage scheme interleaves
a movie with itself (while satisfying the constraints on video and audio block allocation. This approach minimizes the starting delay and the
buffer requirement at the user end, while ensuring a jitter-free display for every request. In order to minimize the starting
delay and to support more non-concurrent requests, we have proposed the use of multiple disks for the same movie. Since a
disk needs to hold only one movie, an array of inexpensive disks can be used, which reduces the overall cost of the proposed
system. A scheme supported by our disk storage method to provide all the functions of a remote control such as “fast-forwarding”,
“rewinding” (with play “on” or “off”), “pause” and “play” has also been discussed. This scheme handles a user request independent
of others and satisfies it without degrading the quality of service to other users. The server design presented in this paper
achieves the multiple goals of high disk utilization, global buffer optimization, cost-effectiveness and high-quality service
to the users. 相似文献