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81.
The sensory-motor skills of persons with neuromuscular disabilities have been shown to be enhanced by intensive and repetitive therapeutic interventions. This paper describes a form of low immersion virtual reality and a prototype, open source system that allow a user with significant physical disability to actively interact with computer-generated objects whose behaviors promote a game-like interaction. Unlike fully immersive and haptic virtual reality, this approach frees the user from head-mounted displays and gloves. It extracts the user’s real-time silhouette from the output of a remote video camera and uses that two-dimensional outline to interact with graphical objects on screen. In contrast to video games that have been modified with specialized interfaces, this virtual interaction system promotes the repetitive use of goal directed movements of the arms and body, which are essential to promote cortical reorganization, as well as discourage unwanted changes in muscle tissue that result in contracture. A prototype system demonstrates the potential of low immersion technology to motivate users and encourage participation in therapy. It also offers the potential of accommodating the sensory-motor skills of individuals with very significant impairment. The behaviors of the computer-generated graphics can be altered to allow use by those with very limited range of motion and/or motor control. These behaviors can be adjusted to provide a continuing challenge as the user’s skills improve. This prototype is described in terms of functional capabilities that include a silhouette extraction from a video image, and generation of graphical objects that interact with the silhouette. The work is extended with a discussion of a more sophisticated region of interest detection algorithm that can select specific parts of the body.  相似文献   
82.
We give a direct proof by generic reduction that testing validity of formulas in a decidable rudimentary theory Ω of finite typed sets (Henkin, Fundamenta Mathematicæ 52 (1963) 323–344) requires space and time exceeding infinitely often(1)where n denotes the length of input. This gives the highest currently known lower bound for a decidable logical theory and affirmatively settles Problem 10.13 from (Compton and Henson, Ann. Pure Applied Logic 48 (1990) 1–79):
Is there a “natural” decidable theory with a lower bound of the form exp(f(n)), where f is not linearly bounded?
The highest previously known lower (and upper) bounds for “natural” decidable theories, like WS1S, S2S, are of the form exp(dn), with just linearly growing stacks of twos.Originally, the lower bound (1) for Ω was settled in (12th Annual IEEE Symposium on Logic in Computer Science (LICS’97), 1997, 294–305) using the powerful uniform lower bounds method due to Compton and Henson, and probably would never be discovered otherwise. Although very concise, the original proof has certain gaps, because the method was pushed out of the limits it was originally designed and intended for, and some hidden assumptions were violated. This results in slightly weaker bounds—the stack of twos in (1) grows subexponentially, but superpolynomially, namely, as for formulas with fixed quantifier prefix, or as 2cn/log(n) for formulas with varying prefix. The independent direct proof presented in this paper closes the gaps and settles the originally claimed lower bound (1) for the minimally typed, succinct version of Ω.  相似文献   
83.
This report describes the current state of our central research thrust in the area of natural language generation. We have already reported on our text-level theory of lexical selection in natural language generation ([59, 60]), on a unification-based syntactic processor for syntactic generation ([73]) and designed a relatively flexible blackboard-oriented architecture for integrating these and other types of processing activities in generation ([60]). We have implemented these ideas in our prototype generator, Diogenes — a DIstributed, Opportunistic GENEration System — and tested our lexical selection and syntactic generation modules in a comprehensive natural language processing project — the KBMT-89 machine translation system ([15]). At this stage we are developing a more comprehensive Diogenes system, concentrating on both the theoretical and the system-building aspects of a) formulating a more comprehensive theory of distributed natural language generation; b) extending current theories of text organization as they pertain to the task of planning natural language texts; c) improving and extending the knowledge representation and the actual body of background knowledge (both domain and discourse/pragmatic) required for comprehensive text planning; d) designing and implementing algorithms for dynamic realization of text structure and integrating them into the blackboard style of communication and control; e) designing and implementing control algorithms for distributed text planning and realization. In this document we describe our ideas concerning opportunistic control for a natural language generation planner and present a research and development plan for the Diogenes project.Many people have contributed to the design and development of the Diogenes generation system over the last four years, especially Eric Nyberg, Rita McCardell, Donna Gates, Christine Defrise, John Leavitt, Scott Huffman, Ed Kenschaft and Philip Werner. Eric Nyberg and Masaru Tomita have created genkit, which is used as the syntactic component of Diogenes. A short version of this article appeared in Proceedings of IJCAI-89, co-authored with Victor Lesser and Eric Nyberg. To all the above many thanks. The remaining errors are the responsibility of this author.  相似文献   
84.
 High-power ball mill activation of the mixture of hydrated zirconium and lanthanum salts (oxonitrates, oxochlorides) with ammonium phosphate followed by hydrothermal treatment at temperatures not exceeding 200°C and a nearly neutral pH was found to yield crystalline dispersed phase of a cubic NH4Zr2(PO4)3 type along with admixtures of disordered orthorhombic compounds of a zirconium orthophosphate type. In the same conditions and at the same Zr/P ratio, hydrothermal treatment of gels obtained by reacting mixed zirconium and lanthanum nitrates solutions with ammonium phosphates yields no crystalline products, and only treatment in acid media generates a phase of the α-ZrPO4(OH) type coexisting with the NH4Zr2(PO4)3 phase if polyethylene oxide is present. X-ray powder diffraction, transmission electron microscopy, 31MAS-NMR, FTIRS and thermal analysis were applied to elucidate factors affecting crystallization of complex zirconium phosphates in the hydrothermal conditions. The most essential factor appears to be generation of some nuclei of zirconium phosphates under high pressures developed in the course of mixed solids mechanical activation. These nuclei are embedded into matrix of such well-crystallized solid products as ammonium nitrate or chloride. Hence, metastable cubic or orthorhombic structure of the phases obtained via mechanical activation route can be assigned to the nuclei-matrix orientation relationship. Due to easily scaled-up synthesis procedure, these results appear to be very promising for manufacturing of dispersed framework zirconium phosphates as acid catalysts or fast proton conductors. Received: 18 November 1998 / Reviewed and accepted: 2 December 1998  相似文献   
85.
This paper analyzes the structure and meaning of text elements cross-linguistically and discusses how that information can be elicited from people in a way that is directly useful for NLP applications. We describe a recently developed computer-based linguistic knowledge elicitation system that initiates a new paradigm of knowledge acquisition methodologies for NLP. In particular, we describe the natural language phenomena the system seeks to cover, the approach to knowledge elicitation and its rationale, the elicitation modules themselves, and broader implications of this work.  相似文献   
86.
This article discusses the various aspects of designing a system for eliciting knowledge about language from informants. For each design aspect, various options for implementation are presented, along with their pros, cons, and repercussions for other parts of the knowledge elicitation system. A running example throughout the text is taken from the paradigmatic morphology elicitation module of a system called Boas, which elicits knowledge to support a machine translation system. The main point of the article is an argument about the necessity to analyze the design choice space for complex natural language processing (NLP) systems early, comprehensively, and overtly.  相似文献   
87.
Multiple-scale averaging is applied to the nonlinear Schrödinger equation with rapidly varying coefficients, and use the results to analyze pulse propagation in an optical fiber when a periodic dispersion map is employed. The effects of fiber loss and repeated amplification are taken into account by use of a coordinate transformation to relate the pulse dynamics in lossy fibers to that in equivalent lossless fibers. Second-order averaging leads to a general evolution equation that is applicable to both return-to-zero (soliton) and non-return-to-zero encoding schemes. The resulting equation is then applied to the specific case of solitons, and an asymptotic theory for the pulse dynamics is developed. Based upon the theory, a simple and effective design of two-step dispersion maps that are advantageous for wavelength-division-multiplexed soliton transmission is proposed. Theuse of these specifically designed dispersion maps allows simultaneous minimization of dispersive radiation in several different channels.  相似文献   
88.
This is the first part of a large survey paper in which we analyze recent literature on Formal Concept Analysis (FCA) and some closely related disciplines using FCA. We collected 1072 papers published between 2003 and 2011 mentioning terms related to Formal Concept Analysis in the title, abstract and keywords. We developed a knowledge browsing environment to support our literature analysis process. We use the visualization capabilities of FCA to explore the literature, to discover and conceptually represent the main research topics in the FCA community. In this first part, we zoom in on and give an extensive overview of the papers published between 2003 and 2011 on developing FCA-based methods for knowledge processing. We also give an overview of the literature on FCA extensions such as pattern structures, logical concept analysis, relational concept analysis, power context families, fuzzy FCA, rough FCA, temporal and triadic concept analysis and discuss scalability issues.  相似文献   
89.
One of the main problems to be solved while assisting inter-human conflict resolution is how to reuse the previous experience with similar agents. A machine learning technique for handling scenarios of interaction between conflicting human agents is proposed. Scenarios are represented by directed graphs with labelled vertices (for communicative actions) and arcs (for temporal and causal relationships between these actions and their parameters). For illustrative purposes, classification of a scenario is computed by comparing partial matching of its graph with graphs of positive and negative examples. Nearest Neighbour learning is followed by the JSM-based learning which minimised the number of false negatives and takes advantage of a more accurate way of matching sequences of communicative actions. Developed scenario representation and comparative analysis techniques are applied to the classification of textual customer complaints. It is shown that analysing the structure of communicative actions without context information is frequently sufficient to estimate complaint validity. Therefore, being domain-independent, proposed machine learning technique is a good compliment to a wide range of customer relation management applications where formal treatment of inter-human interactions is required in a decision-support mode.  相似文献   
90.
Experimental and thermodynamic modeling studies have been carried out on the Zn-Fe-Si-O system. This research is part of a wider program to characterize zinc/lead industrial slags and sinters in the PbO-ZnO-SiO2-CaO-FeO-Fe2O3 system. Experimental investigations involve high-temperature equilibration and quenching techniques followed by electron probe X-ray microanalysis (EPMA). Liquidus temperatures and solid solubilities of the crystalline phases were measured in the temperature range from 1200 °C to 1450 °C (1473 to 1723 K) in the zinc ferrite, zincite, willemite, and tridymite primary-phase fields in the Zn-Fe-Si-O system in air. These equilibrium data for the Zn-Fe-Si-O system in air, combined with previously reported data for this system, were used to obtain an optimized self-consistent set of parameters of thermodynamic models for all phases.  相似文献   
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