6,049 research outputs found
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Optimizing Radiant Systems for Energy Efficiency and Comfort
Radiant cooling and heating systems provide an opportunity to achieve significant energy savings, peak demand reduction, load shifting, and thermal comfort improvements compared to conventional all-air systems. As a result, application of these systems has increased in recent years, particularly in zero-net-energy (ZNE) and other advanced low-energy buildings. Despite this growth, completed installations to date have demonstrated that controls and operation of radiant systems can be challenging due to a lack of familiarity within the heating, ventilation, and air-conditioning (HVAC) design and operations professions, often involving new concepts (particularly related to the slow response in high thermal mass radiant systems). To achieve the significant reductions in building energy use proposed by California Public Utilities Commission’s (CPUC’s) Energy Efficiency Strategic Plan that all new non-residential buildings be ZNE by 2030, it is critical that new technologies that will play a major role in reaching this goal be applied in an effective manner. This final report describes the results of a comprehensive multi-faceted research project that was undertaken to address these needed enhancements to radiant technology by developing the following: (1) sizing and operation tools (currently unavailable on the market) to provide reliable methods to take full advantage of the radiant systems to provide improved energy performance while maintaining comfortable conditions, (2) energy, cost, and occupant comfort data to provide real world examples of energy efficient, affordable, and comfortable buildings using radiant systems, and (3) Title-24 and ASHRAE Standards advancements to enhance the building industry’s ability to achieve significant energy efficiency goals in California with radiant systems. The research team used a combination of full-scale fundamental laboratory experiments, whole-building energy simulations and simplified tool development, and detailed field studies and control demonstrations to assemble the new information, guidance and tools necessary to help the building industry achieve significant energy efficiency goals for radiant systems in California
Changes in the McGurk Effect across Phonetic Contexts. I. Fusions
The McGurk effect has generally been studied within a limited range of phonetic contexts. With the goal of characterizing the McGurk effect through a wider range of contexts, a parametric investigation across three different vowel contexts, /i/, /α/, and /u/, and two different syllable types, consonant-vowel (CV) and vowel-consonant (VC), was conducted.
This paper discusses context-dependent changes found specifically in the McGurk fusion phenomenon (Part II addresses changes found in combination percepts). After normalizing for differences in the magnitude of the McGurk effect in different contexts, a large qualitative change in the effect across vowel contexts became apparent. In particular, the frequency of illusory /g/ percepts increased relative to the frequency of illusory /d/ percepts as vowel context was shifted from /i/ to /α/ to /u/. This trend was seen in both syllable sets, and held regardless of whether the visual stimulus used was a /g/ or /d/ articulation.
This qualitative change in the McGurk fusion effect across vowel environments corresponded systematically with changes in the typical second formant frequency patterns of the syllables presented. The findings are therefore consistent with sensory-based theories of speech perception which emphasize the importance of second formant patterns as cues in multimodal speech perception.National Institue on Deafness and other Communication Disorders (R29 02852); Alfred P. Sloan Foundation and National Institute on Deafness and other Communication Disorders (R29 02852
Changes in the McGurk Effect Across Phonetic Contexts
To investigate the process underlying audiovisual speech perception, the McGurk illusion was examined across a range of phonetic contexts. Two major changes were found. First, the frequency of illusory /g/ fusion percepts increased relative to the frequency of illusory /d/ fusion percepts as vowel context was shifted from /i/ to /a/ to /u/. This trend could not be explained by biases present in perception of the unimodal visual stimuli. However, the change found in the McGurk fusion effect across vowel environments did correspond systematically with changes in second format frequency patterns across contexts. Second, the order of consonants in illusory combination percepts was found to depend on syllable type. This may be due to differences occuring across syllable contexts in the timecourses of inputs from the two modalities as delaying the auditory track of a vowel-consonant stimulus resulted in a change in the order of consonants perceived. Taken together, these results suggest that the speech perception system either fuses audiovisual inputs into a visually compatible percept with a similar second formant pattern to that of the acoustic stimulus or interleaves the information from different modalities, at a phonemic or subphonemic level, based on their relative arrival times.National Institutes of Health (R01 DC02852
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A Prototype Toolkit For Evaluating Indoor Environmental Quality In Commercial Buildings
Measurement of building environmental parameters is often complex, expensive, and not easily proceduralized in a manner that covers all commercial buildings. Evaluating building indoor environmental quality performance is therefore not standard practice. This project developed a prototype toolkit that addressed existing barriers to widespread indoor environmental quality performance evaluation. A toolkit with both hardware and software elements was designed for practitioners around the indoor environmental quality requirements of the American Society of Heating, Refrigeration and Air Conditioning Engineers / Chartered Institution of Building Services / United States Green Building Council Performance Measurement Protocols. This unique toolkit was built on a wireless mesh network with a web-based data collection, analysis, and reporting application. The toolkit provided a fast, robust deployment of sensors, real-time data analysis, Performance Measurement Protocol-based analysis methods and a scorecard and report generation tools. A web-enabled Geographic Information System-based metadata collection system also reduced field-study deployment time. The toolkit was evaluated through three case studies, which were discussed in this report
Dynamics of modulated and composite aperiodic crystals: the signature of the inner polarization in the neutron coherent inelastic scattering
We compare within an unifying formalism the dynamical properties of modulated
and composite aperiodic (incommensurate) crystals. We discuss the concept of
inner polarization and we define an inner polarization parameter beta that
distinguishes between different acoustic modes of aperiodic crystals. Although
this concept has its limitations, we show that it can be used to extract
valuable information from neutron coherent inelastic scattering experiments.
Within certain conditions, the ratio between the dynamic and the static
structure factors at various Bragg peaks depends on beta. We show how the
knowledge of beta for modes of an unknown structure can be used to decide
whether the structure is composite or modulated. Furthermore, the same
information can be used to predict scattered intensity within unexplored
regions of the reciprocal space, being thus a guide for experiment
The phonological status of English oral stops after tautosyllabic /s/ : evidence from speakers' classificatory behaviour
The classification of oral stops after tautosyllabic /s/ in English is an old phonological problem to which different solutions have been proposed. In an attempt to provide experimental evidence on the classification of oral bilabial stops after tautosyllabic /s/ by native speakers of English, a concept formation experiment was conducted. The results showed that out of the four main phonological theoretical views on the classification of oral stops after tautosyllabic /s/, the solution which treats those speech segments as allophones of the phonemes /p, t, k/ is the most plausible from the point of view of language users' classificatory behaviour
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