56 resultados para Texas Instruments TMS320C80 DSP
Resumo:
The emergence of programmable logic devices as processing platforms for digital signal processing applications poses challenges concerning rapid implementation and high level optimization of algorithms on these platforms. This paper describes Abhainn, a rapid implementation methodology and toolsuite for translating an algorithmic expression of the system to a working implementation on a heterogeneous multiprocessor/field programmable gate array platform, or a standalone system on programmable chip solution. Two particular focuses for Abhainn are the automated but configurable realisation of inter-processor communuication fabrics, and the establishment of novel dedicated hardware component design methodologies allowing algorithm level transformation for system optimization. This paper outlines the approaches employed in both these particular instances.
Resumo:
To develop real-time simulations of wind instruments, digital waveguides filters can be used as an efficient representation of the air column. Many aerophones are shaped as horns which can be approximated using conical sections. Therefore the derivation of conical waveguide filters is of special interest. When these filters are used in combination with a generalized reed excitation, several classes of wind instruments can be simulated. In this paper we present the methods for transforming a continuous description of conical tube segments to a discrete filter representation. The coupling of the reed model with the conical waveguide and a simplified model of the termination at the open end are described in the same way. It turns out that the complete lossless conical waveguide requires only one type of filter.Furthermore, we developed a digital reed excitation model, which is purely based on numerical integration methods, i.e., without the use of a look-up table.
Resumo:
Capillary-based systems for measuring the input impedance of musical wind instruments were first developed in the mid-20th century and remain in widespread use today. In this paper, the basic principles and assumptions underpinning the design of such systems are examined. Inexpensive modifications to a capillary-based impedance measurement set-up made possible due to advances in computing and data acquisition technology are discussed. The modified set-up is able to measure both impedance magnitude and impedance phase even though it only contains one microphone. In addition, a method of calibration is described that results in a significant improvement in accuracy when measuring high impedance objects on the modified capillary-based system. The method involves carrying out calibration measurements on two different objects whose impedances are well-known theoretically. The benefits of performing two calibration measurements (as opposed to the one calibration measurement that has been traditionally used) are demonstrated experimentally through input impedance measurements on two test objects and a Boosey and Hawkes oboe. © S. Hirzel Verlag · EAA.
Resumo:
Methods are presented for the rapid design of DSP ASICs based on the use of hierarchical VHDL libraries. These are portable across many silicon foundries and allow complex DSP silicon systems to be developed in a fraction of the time normally required. Resulting designs are highly competitive with ones created using conventional methods. The approach is illustrated by its application to ADPCM codec and DCT cores.
Resumo:
Details are presented of the DAC (DSP ASIC Compiler) silicon compiler framework. DAC allows a non-specialist to automatically design DSP ASICs and DSP ASIC cores directly form a high level specification. Typical designs take only several minutes and the resulting layouts are comparable in area and performance to handcrafted designs.
Resumo:
Methods are presented for the rapid design of DSP ASICs based on the use of a series of hierarchical VHDL libraries which are portable across many silicon foundries. These allows complex DSP silicon systems to be developed in a small fraction of the time normally required. Resulting designs are highly competitive with those developed using more conventional methods. The approach is illustrated using several examples. These include ADPCM codecs, as well as DCT and FFT cores.
Resumo:
Data obtained with any research tool must be reproducible, a concept referred to as reliability. Three techniques are often used to evaluate reliability of tools using continuous data in aging research: intraclass correlation coefficients (ICC), Pearson correlations, and paired t tests. These are often construed as equivalent when applied to reliability. This is not correct, and may lead researchers to select instruments based on statistics that may not reflect actual reliability. The purpose of this paper is to compare the reliability estimates produced by these three techniques and determine the preferable technique. A hypothetical dataset was produced to evaluate the reliability estimates obtained with ICC, Pearson correlations, and paired t tests in three different situations. For each situation two sets of 20 observations were created to simulate an intrarater or inter-rater paradigm, based on 20 participants with two observations per participant. Situations were designed to demonstrate good agreement, systematic bias, or substantial random measurement error. In the situation demonstrating good agreement, all three techniques supported the conclusion that the data were reliable. In the situation demonstrating systematic bias, the ICC and t test suggested the data were not reliable, whereas the Pearson correlation suggested high reliability despite the systematic discrepancy. In the situation representing substantial random measurement error where low reliability was expected, the ICC and Pearson coefficient accurately illustrated this. The t test suggested the data were reliable. The ICC is the preferred technique to measure reliability. Although there are some limitations associated with the use of this technique, they can be overcome.
Resumo:
Researchers and clinicians have experienced substantial difficulties locating measures that are suitable for use within palliative care settings. This article details the psychometric properties of nine instruments designed to assess the following psychosocial characteristics of family caregivers: competence, mastery, self-efficacy, burden, optimism, preparedness, social support, rewards, and mutuality. Results are based on the responses of 106 primary family caregivers caring for relatives dying of cancer. Principal components extraction with varimax rotation was used to explore the underlying structure of each measure. Following the exclusion of complex variables, suggested components for most measures comprised relatively homogenous items, which were good to excellent measures of each component. Some components comprised only two items; however, Cronbach's alphas typically indicated moderate to high levels of internal consistency. Overall, the results of this study suggest that most of the measures analyzed, excepting the mastery and mutuality scales, can be recommended to examine the family caregiver experience and test supportive interventions.
Resumo:
PURPOSE: To identify vision Patient-Reported Outcomes instruments relevant to glaucoma and assess their content validity.
METHODS: MEDLINE, MEDLINE in Process, EMBASE and SCOPUS (to January 2009) were systematically searched. Observational studies or randomised controlled trials, published in English, reporting use of vision instruments in glaucoma studies involving adults were included. In addition, reference lists were scanned to identify additional studies describing development and/or validation to ascertain the final version of the instruments. Instruments' content was then mapped onto a theoretical framework, the World Health Organization International Classification of Functioning, Disability and Health. Two reviewers independently evaluated studies for inclusion and quality assessed instrument content.
RESULTS: Thirty-three instruments were identified. Instruments were categorised into thirteen vision status, two vision disability, one vision satisfaction, five glaucoma status, one glaucoma medication related to health status, five glaucoma medication side effects and six glaucoma medication satisfaction measures according to each instruments' content. The National Eye Institute Visual Function Questionnaire-25, Impact of Vision Impairment and Treatment Satisfaction Survey-Intraocular Pressure had the highest number of positive ratings in the content validity assessment.
CONCLUSION: This study provides a descriptive catalogue of vision-specific PRO instruments, to inform the choice of an appropriate measure of patient-reported outcomes in a glaucoma context.
Resumo:
This paper introduces a series of new musical instruments that have been designed to
address questions relating to performative virtuosity in the area of ensemble-based
improvisation. The intentionally exploited inconsistent nature of these instruments
raises questions around traditional notions of instrument mastery and opens up
possible methods of recon?guring the performer-instrument relationship.
Resumo:
Objective: Cancer may impact negatively on an informal caregiver's health long after treatment has ended. This review identifies the self-report measures currently in use to measure caregivers need for support and determines their scientific soundness and clinical utility.
Method: A systematic electronic database search of Medline, CINAHL, PsychINFO, BNI ProQuest was conducted. The psychometric properties and clinical utility of needs assessment tools for caregivers of cancer survivors (excluding advanced disease) were extracted and summarised.
Results: Seven cancer survivor caregiver needs assessment tools were identified. Data on instrument development was well reported, although variability was noted in their structure and content. The majority demonstrated some degree of reliability and validity; only two were evaluated for test–retest reliability (CaSPUN and SPUNS) with only the SPUNS showing a high degree of reliability over time. The Health Care Needs Survey (HCNS), Needs Assessment of Family Caregivers-Cancer (NAFC-C) and Cancer Caregiving Tasks Consequences and Needs Questionnaire (CaTCoN) have been validated at various stages of the cancer continuum. Minimal data was available on responsiveness.
Conclusion: All assessment tools identified require further psychometric analysis. For research purposes, the use of the SPUNS (with its acceptable test–retest reliability) appears most appropriate; although its length may be of concern for clinical use; therefore, the shorter SCNS-P&C is likely to be more suitable for use clinically. At present, the NAFC-C demonstrates a great potential in both the research and clinical environments; however, it requires further psychometric testing before it can be fully recommended. Further analysis is necessary on ideal response formats and the meaning of a total needs score.