2,461 research outputs found
Integrated sensor and controller framework : a thesis presented in partial fulfilment of the requirements for the degree of Master of Engineering in Information and Telecommunications Engineering at Massey University, Palmerston North, New Zealand
This thesis presents a software platform to integrate sensors, controllers, actuators and instrumentation within a common framework. This provides a flexible, reusable, reconfigurable and sealable system for designers to use as a base for any sensing and control platform. The purpose of the framework is to decrease system development time, and allow more time to be spent on designing the control algorithms, rather than implementing the system. The architecture is generic, and finds application in many areas such as home, office and factory automation, process and environmental monitoring, surveillance and robotics. The framework uses a data driven design, which separates the data storage areas (dataslots) from the components of the framework that process the data (processors). By separating all the components of the framework in this way, it allows a flexible configuration. When a processor places data into a dataslot, the dataslot queues all the processors that use that data to run. A system that is based on this framework is configured by a text file. All the components are defined in the file, with the interactions between them. The system can be thought of as multiple boxes, with the text file defining how these boxes are connected together. This allows rapid configuration of the system, as separate text files can be maintained for different configurations. A text file is used for the configuration instead of a graphical environment to simplify the development process, and to reduce development time. One potential limitation of the approach of separating the computational components is an increased overhead or latency. It is acknowledged that this is an important consideration in many control applications, so the framework is designed to minimise the latency through implementation of prioritized queues and multitasking. This prevents one slow component from degrading the performance of the rest of the system. The operation of the framework is demonstrated through a range of different applications. These show some of the key features including: acquiring data, handling multiple dataslots that a processor reads from or writes to, controlling actuators, how the virtual instrumentation works, network communications, where controllers fit into the framework, data logging, image and video dataslots. timers and dynamically linked libraries. A number of experiments show the framework under real conditions. The framework's data passing mechanisms are demonstrated, a simple control and data logging application is shown and an image processing application is shown to demonstrate the system under load. The latency of the framework is also determined. These illustrate how the framework would operate under different hardware and software applications. Work can still be done on the framework, as extra features can be added to improve the usability. Overall, this thesis presents a flexible system to integrate sensors, actuators, instrumentation and controllers that can be utilised in a wide range of applications
Automaton-based parsing for lexicalized grammars
In wide-coverage lexicalized grammars many of the elementary structures have substructures in common. This means that during parsing some of the computation associated with different structures is duplicated. This paper explores ways in which the grammar can be precompiled into finite state automata so that some of this shared structure results in shared computation at run-time. 1 Introduction This paper investigates grammar precompilation techniques aimed at improving the parsing performance of lexicalized grammars. In a wide-coverage lexicalized grammar, such as the XTAG grammar (XTAG-Group, 1995), many of the elementary structures 1 have substructures in common. If such structures are viewed as independent by a parsing algorithm, the computation associated with their shared structure may be duplicated. This paper explores ways in which the grammar can be precompiled so that some of this shared structure results in shared computation at run-time. We assume as a starting point a co..
A Tractable Extension of Linear Indexed Grammars
It has been shown that Linear Indexed Grammars can be processed in polynomial
time by exploiting constraints which make possible the extensive use of
structure-sharing. This paper describes a formalism that is more powerful than
Linear Indexed Grammar, but which can also be processed in polynomial time
using similar techniques. The formalism, which we refer to as Partially Linear
PATR manipulates feature structures rather than stacks.Comment: 8 pages LaTeX, uses eaclap.sty, to appear in EACL-9
On the quantum stability of Q-balls
We consider the evolution and decay of Q-balls under the influence of quantum
fluctuations. We argue that the most important effect resulting from these
fluctuations is the modification of the effective potential in which the Q-ball
evolves. This is in addition to spontaneous decay into elementary particle
excitations and fission into smaller Q-balls previously considered in the
literature, which -- like most tunnelling processes -- are likely to be
strongly suppressed. We illustrate the effect of quantum fluctuations in a
particular model potential, for which we implement the inhomogeneous
Hartree approximation to quantum dynamics and solve for the evolution of
Q-balls in 3+1 dimensions. We find that the stability range as a function of
(field space) angular velocity is modified significantly compared to
the classical case, so that small- Q-balls are less stable than in the
classical limit, and large- Q-balls are more stable. This can be
understood qualitatively in a simple way.Comment: JHEP format, 17+1 pages, 9 figures; v2: improvements to several
figures, text rewritten to improve legibility, conclusions unchanged,
published in JHE
Personality and Response to the Financial Crisis
In a previous study, we found the family of personality traits known as conscientiousness to be associated in cross-sectional analyses with both lifetime earnings and wealth. In this study, we used data from an Internet survey of HRS respondents in the second quarter of 2009 to test whether conscientiousness and other Big Five factors prospectively predicted responses to the financial crisis of 2008/09. In addition, to improve the targeting and design of behavioral interventions for “at-risk” individuals, we examined two specific facets of conscientiousness (i.e., self-control and perseverance) that may be more highly related to these economic outcomes than other facets. Finally, we used data from the Consumption and Activities Mail Survey (CAMS) to examine whether personality is related to the proportion of income saved vs. spent. Missing data precluded sufficiently powerful prospective analyses of personality and responses to the financial crisis. Likewise, data on self-control and perseverance from the 2010 experimental module were not sufficient at the time of final reporting to come to definitive conclusions about how these facets relate to economic outcomes. We did find that conscientious adults save more and spend less of their incomes, whereas adults who are higher in openness to experience (e.g., adventurous, sophisticated) save less and spend more of their income. The robust associations between conscientiousness and economic outcomes suggests further investigation of interventions that improve conscientiousness as well as policies that specifically target less conscientious individuals (e.g., default choices for retirement savings).
Distributional composition using higher-order dependency vectors
This paper concerns how to apply compositional methods to vectors based on grammatical dependency relation vectors. We demonstrate the potential of a novel approach which uses higher-order grammatical dependency relations as features. We apply the approach to adjective-noun compounds with promising results in the prediction of the vectors for (held-out) observed phrases
Evaluation of LTAG parsing with supertag compaction
One of the biggest concerns that has been raised over the feasibility of using large-scale LTAGs in NLP is the amount of redundancy within a grammar¿s elementary tree set. This has led to various proposals on how best to represent grammars in a way that makes them compact and easily maintained (Vijay-Shanker and Schabes, 1992; Becker, 1993; Becker, 1994; Evans, Gazdar and Weir, 1995; Candito, 1996). Unfortunately, while this work can help to make the storage of grammars more efficient, it does nothing to prevent the problem reappearing when the grammar is processed by a parser and the complete set of trees is reproduced. In this paper we are concerned with an approach that addresses this problem of computational redundancy in the trees, and evaluate its effectiveness
Encoding Lexicalized Tree Adjoining Grammars with a Nonmonotonic Inheritance Hierarchy
This paper shows how DATR, a widely used formal language for lexical
knowledge representation, can be used to define an LTAG lexicon as an
inheritance hierarchy with internal lexical rules. A bottom-up featural
encoding is used for LTAG trees and this allows lexical rules to be implemented
as covariation constraints within feature structures. Such an approach
eliminates the considerable redundancy otherwise associated with an LTAG
lexicon.Comment: Latex source, needs aclap.sty, 8 page
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