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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
71

SHORT TERM AUDITORY STORAGE CAPACITY OF SKILLED SIGNERS FOR LINGUISTIC INFORMATION.

VALLANDINGHAM, RICHARD ROBERT. January 1982 (has links)
The principle purpose of this study was to investigate the short term auditory storage and retrieval abilities of skilled interpreters for the deaf. Secondary attention was given to age, sex, and educational level variables related to recall abilities. It was assumed that the task of interpreting spoken English to ASL involved short term auditory storage, the efficacy of which was related to chunking abilities of the listener. Measures of short term storage for familiar and novel information (sentences) were employed by estimates of chunking efficiency. Three groups of ten subjects each made up the sample population. Group A was composed of individuals with interest in but limited knowledge of sign language. Group B was composed of individuals with no knowledge of sign language. Group C was composed of individuals holding the Comprehensive Skills Certificate from the National Registry of Interpreters for the Deaf. Free-recall short term storage tasks were utilized to evaluate recall efficiency of the sample groups for familiar and unfamiliar information. English proverbs were used for the familiar stimuli and novel sentences generated from the proverbs were used for the unfamiliar stimuli. Results indicate that skilled interpreters perform extremely efficiently on recall tasks involving conceptually accurate recall of novel sentences. No significant relationship was noted between age, sex, and educational level factors and recall scores. The results were interpreted as supporting the hypothesis that skilled interpreters for the hearing impaired are efficient chunkers of linguistic information. A discussion of the results and needs for further research are presented.
72

The role of memory, phonological awareness and syntactic awareness in reading

Leather, Cathy V. January 1994 (has links)
No description available.
73

Short term memory

Thomson, Neil January 1979 (has links)
The eight experiments reported in this thesis are designed to investigate the idea that in verbal short-term memory (STM) material decays over time and this decay is prevented by rehearsal. It follows that the capacity of STM when measured in words should be inversely proportional to the time taken to rehearse the words. Consequently, subjects should be able to recall more short duration words than long duration words. In contrast to this hypothesis is the idea that the capacity of STM is a fixed number of chunks, where chunks are a structural characteristic of the material. The first four experiments are designed so that these alternative hypotheses produce conflicting predictions and, in all cases, the hypotheses derived from decay theory are supported. It is shown that serial recall performance is very well predicted by the time taken to say the words and that the relationship between word duration and recall is of the type predicted by decay theory. The second set of experiments are based on the assumption that both STM and long-term memory (LTM) contribute to performance in serial recall tasks. The purpose of the experiments is to determine whether it is the STM or LTM component that is sensitive to word duration. It is predicted, in line with a decay theory of forgetting in STM, that the STM component is sensitive to word duration. The experiments are designed to produce sizable contributions from both stores in order to test this hypothesis. The results support the hypothesis in showing that variables known to affect STM, such as acoustic similarity, interact with word duration, while variables known to affect LTM, such as repeated presentations of the same list, show no such interaction. The results are interpreted in terms of decay theory and the different versions of this theory that have been proposed are considered. It is concluded that while no version of the theory is completely adequate, there is no evidence that invalidates the central assumptions, viz. that in STM items are forgotten by decay and that one of the functions of rehearsal is to prevent this decay.
74

Application of Mathematical Programming to Short-Term Operation Planning of Hydrothermal Power System

Habibollahzadeh, Hooshang January 1984 (has links)
The thesis contains the results of a reseach project on application of mathematical programming methods to short-term operation planning of large hydrothermal power systems. The project was aimed at devoeloping efficient solution techniques that are practially applicable to large systems. The problem is modeled as a large mixed integer program. / This thesis contains the results of a research project on application of mathematical programming methods to short-term operation planning of large hydrothermal power systems. The work was carried out at the Department of Electric Power System Engineering of the Royal Institute of Technology, Stockholm, Sweden.   The project was aimed at developing efficient solution techniques that are practically applicable to large scale power systems. The thesis consists of seven chap­ters and four appendices.   The increasing importance and the magnitude of the expenditures associated with it have created an urgent necessity to operate the electric energy systems in an optimal economic manner. The optimal operation planning, as explained in chapter 1, can be divided into several subproblems which are more computationally manageable. The short-term operation planning contains two of these subproblems, namely; weekly and daily operation planning.   The problem, as modeled in chapter 2 for systems with a considerable amount of hydro, is a large mixed integer program. The objective for this problem is the produc­tion cost of the thermal plants. The optimization hori­zon varies from one week to one day, and the discretiza­tion intervals are normally chosen between one to several hours.   In chapter 3, Lagrangian relaxation technique and Benders' method are introduced to decompose the problem with re­spect to hydro and thermal systems. This makes it poss­ible to exploit the special characteristics of each system.   The hydro problem is a large linear program with embedded network structure. In chapter 4, several solution techniques are introduced that exploit this special structure of the large number of constraints involved. The small nonlinearities of hydro problem and· head variation are also treated in this chapter.   The thermal problem involves integer variables. In cha­ter 5, the special structure of this problem is consider­ed, which results in a considerable amount of reductions. Branch and bound, shortest path, and discrete dynamic programming methods are considered for solution of thermal system. This chapter is extended to consider hydro­thermal power system with low amounts of hydro.   Chapter 6 concerns network labeling system, network flow algorithms, and sparsity techniques, which were considered in the implementation of the algorithms.   Finally, the test results and conclusions from application of different techniques are considered and discussed in chapter 7. The Swedish System has been used to prove the applicability and efficiency of the developed techniques. The short-term model can be used in operation, as an engineering tool for decision making, and in planning, to analyze alternative planning schemes. / <p>QC 20161206</p>
75

The Effects of Anxiety on the Short-term Memory Proficiency of College Students

Payne, Terry D. 06 1900 (has links)
Based on the review of literature, it has been demonstrated that anxiety has some detrimental effects on the short-term memory functions of the college student. In order to improve the experimental methodology, the present study combined Type I and Type II studies of short-term memory as a function of anxiety. The two were combined so that the major criticisms in each study were controlled.
76

Investigating the short term memory visual binding impairment in Alzheimer's Disease

Killin, Lewis Oliver Jack January 2015 (has links)
Patients with Alzheimer’s Disease (AD) demonstrate a sensitive and specific short-term memory impairment for visual bindings (e.g. the combination of shapes and colours) that is absent in healthy ageing (Parra et al., 2009) and other dementias (Della Sala et al., 2012). This impairment is also seen in cases of asymptomatic, familial AD (Parra et al., 2010). The visual short term memory binding (VSTMB) impairment in AD has clear clinical and neuropsychological implications which are investigated in this thesis. Firstly, the utility of the VSTMB paradigm was contrasted with the Free and Cued Selective Reminding Task with Immediate Recall (FCSRT-IR) – which has recently been posited as a useful diagnostic marker of AD pathology (Dubois et al., 2014). The results indicated that the former is not affected by age, where the latter is, suggesting that the VSTMB paradigm provides a suitable baseline to measure cognitive decline associated with AD. The development of a parallel version of the FCSRT-IR is also reported. Secondly, a 24-week longitudinal study of patients receiving treatment for AD (donepezil hydrochloride) revealed that patients who respond to this treatment on cognitive scales also experience change in VSTMB performance. These responders, however, did not significantly improve on the FCSRT-IR during the study. This suggests that anticholinergic treatment may have an effect on VSTMB performance. Additionally, a meta-analysis that investigates the effect of a study’s funding on donepezil RCT outcome showed that industry-funded studies report larger changes in cognition than independent studies. Lastly, an auditory binding experimental paradigm was developed, with a view to reveal a non-visual binding impairment in AD, investigating whether the binding impairment reflects a general or modality-specific memory impairment. The overall conclusions of this thesis confirm that the VSTMB impairment has significant promise as an index of AD. The auditory binding paradigm, by contrast, shares conceptual similarity with the VSTMB paradigm, but may have restricted clinical use within the AD patient population.
77

The Nature of Working Memory: Separate, Flexible Resources for Location- vs. Feature-based Representations in Visual Short-term Memory

Adamo, Maha 06 December 2012 (has links)
Working memory, or the ability to maintain and manipulate information in mind when it is no longer physically present, is a pervasive yet severely capacity-limited component of cognition. Visual working memory, also known as visual short-term memory (VSTM), is limited to three or four items on average, with individual differences that range from roughly two to up to six items. Despite agreement that capacity is functionally limited, the current literature is split with respect to the nature of VSTM representations on two key questions: (1) What information is maintained in VSTM? (2) How is information stored in VSTM? The studies presented here address these questions using an event-related potential (ERP) task and a series of behavioural experiments that incorporate attentional selection via retrospective cueing (retro-cues). Experiment 1 manipulated both the number of features and the number of locations to be remembered in a lateralized change-detection task, with differences in the amplitude and topography of the resulting contralateral delay activity (CDA) indicating separate stores for features and locations. Experiments 2a-c established the basic effects of retro-cues on change-detection tasks, showing that attentional selection operated on one system at a time, with overall shorter response times and increased capacity estimates once baseline capacity was exceeded. Experiments 3a-b demonstrated that retro-cues biased VSTM resources to the cued item at the expense of representational strength of the other, non-cued items, showing flexible reallocation of resources. Experiments 4a-b presented multiple retro-cues to further examine the flexible reallocation of resources in VSTM, showing that capacity benefits depended on spatial specificity of retro-cues and that VSTM weights could be reallocated multiple times before probe comparison. Experiment 5 discounted the potential role of a general alerting mechanism in boosting capacity estimates, showing again that the retro-cue benefit required specificity of the cue. Experiment 6 showed that flexible reallocation of resources within one system did not change the online maintenance of representations within the other system. Thus, the studies collectively address the questions of (1) what and (2) how information is stored by supporting a two-system model of VSTM in which (1) locations and features are stored (2) independently via flexibly allocated resources.
78

Development of efficient encoding in visual working memory

Kibbe, Melissa M., January 2009 (has links)
Thesis (M.S.)--Rutgers University, 2009. / "Graduate Program in Psychology." Includes bibliographical references (p. 32-34).
79

Addressing confounding factors in the study of working memory in aphasia : empirical evaluation of modified tasks and measures /

Ivanova, Maria V. January 2009 (has links)
Thesis (Ph.D.)--Ohio University, June, 2009. / Release of full electronic text on OhioLINK has been delayed until June 1, 2011 Includes bibliographical references (leaves 165-181)
80

Addressing confounding factors in the study of working memory in aphasia empirical evaluation of modified tasks and measures /

Ivanova, Maria V. January 2009 (has links)
Thesis (Ph.D.)--Ohio University, June, 2009. / Title from PDF t.p. Release of full electronic text on OhioLINK has been delayed until June 1, 2011 Includes bibliographical references (leaves 165-181)

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