The Role of Odour Quality in the Perception of Binary and Higher-Order Mixtures

Perception ◽  
10.1068/p7267 ◽  
2012 ◽  
Vol 41 (11) ◽  
pp. 1373-1391 ◽  
Author(s):  
Anna Lindqvist ◽  
Anders Höglund ◽  
Birgitta Berglund
Keyword(s):  
Principal Components Analysis ◽  
Binary Mixtures ◽  
Principal Components ◽  
Degradation Products ◽  
Higher Order ◽  
Pentanoic Acid ◽  
Components Analysis ◽  
Polyamide 6.6

Twenty participants scaled similarities in odour quality, odour intensity and pleasantness/unpleasantness of 10 binary and 5 higher-order mixtures of 5 odorous degradation products from the polymer Polyamide 6.6. The perceived odour qualities of all binary mixtures were represented well as intermediary vectors relative to their component-odour vectors in a three-component principal components analysis. The odour qualities of the “floral/fruity” 2-pentylcyclopentan-1-one and the “sharp/cheese-like” pentanoic acid contributed profoundly to their binary mixtures, as did the “minty” cyclopentanone, but in fewer cases. Conversely, the “ether-like” 2-methyl pyridine and “nutty” butanamide did not contribute much. Odour similarity was shown to be caused by odour quality, rather than odour intensity. Three out of five degradation products formed distinct clusters of odours and were therefore interpreted to be profound contributors to the odour quality of the binary mixtures. The higher-order mixtures created new odour qualities which were completely different and untraceable to their various parts as perceived alone. These results demonstrate that it is critical to research the perception of natural mixtures in order to be able to understand the human olfactory code.

scholarly journals Actividades de Cálculo Diferencial con Computadora: Estudio de Habilidades Matemáticas Desarrolladas

2013 ◽  
Vol 13 (2) ◽  
Author(s):  
Marcela Falsetti ◽  
Adriana Favieri ◽  
Roxana Scorzo ◽  
Betina Williner
Keyword(s):  
Principal Components Analysis ◽  
Principal Components ◽  
Differential Calculus ◽  
Teaching And Learning ◽  
Math Skills ◽  
Specific Content ◽  
Palabras Clave ◽  
Design Activities ◽  
Components Analysis

<p class="p1"><span class="s1"><strong> Resumen</strong>. </span>El presente artículo reporta un estudio transeccional descriptivo sobre el desarrollo de habilidades matemáticas así como la relación de éstas con actividades matemáticas y contenidos específicos. Analizamos producciones escritas de estudiantes de carreras de ingeniería que realizan su primer curso de Cálculo Diferencial. Para esta experiencia han trabajado en un taller usando el software Mathematica®. Describimos los criterios considerados para la clasificación de las actividades y habilidades, los instrumentos para la evaluación y el procesamiento de los datos. En las conclusiones establecemos relaciones entre tipos de actividades y habilidades promovidas y nos referimos al rol del software en la enseñanza y en el aprendizaje de la introducción al Cálculo Diferencial. Finalmente mediante el análisis estadístico descriptivo y el de componentes principales reforzamos la hipótesis de que una habilidad debe medirse en estrecha dependencia con el contenido y la tarea realizada.</p> <p class="p1"><span class="s2"><strong>Palabras clave</strong>: </span>Habilidades matemáticas, diseño de actividades, software matemático de cálculo simbólico y numérico, cálculo diferencial, análisis estadístico por componentes principales.</p> <p class="p1"><span class="s1"><strong> Abstract</strong>. </span>This paper reports a transactional descriptive study on math skills, as part of mathematical competence, and its relationship with math activities and specific content. We analyze written productions of students, from Engineering careers, of the their first-Calculus course. For this experience, they have worked in a workshop using Mathematica ®software. We describe here the criteria used for the classification of activities and skills, the tools for evaluation and processing of the data. In the conclusions we establish relationships between types of activities and skills promoted and we refer to the role of software in teaching and learning in the introductory Differential Calculus course. Finally through descriptive statistical analysis and principal components analysis we also reinforce the hypothesis that a skill should be measured in close dependence on the content and the task.</p> <p class="p1"><span class="s2"><strong>KeyWords</strong>: </span>Math Skills, design activities, mathematical calculus software, Differential Calculus, principal components analysis.</p>

Singapore's Online Retail Deviants

2014 ◽  
pp. 449-470
Author(s):  
Ronan de Kervenoael ◽  
Alan Hallsworth ◽  
David Tng
Keyword(s):  
Principal Components Analysis ◽  
Principal Components ◽  
Mass Production ◽  
Online Shopping ◽  
Theoretical Frameworks ◽  
Online Retail ◽  
Institutional Entrepreneurs ◽  
Components Analysis ◽  
Media Practices

Geography, retailing, and power are institutionally bound up together. Within these, the authors situate their research in Clegg's work on power. Online shopping offers a growing challenge to the apparent hegemony of traditional physical retail stores' format. While novel e-formats appear regularly, blogshops in Singapore are enjoying astonishing success that has taken the large retailers by surprise. Even though there are well-developed theoretical frameworks for understanding the role of institutional entrepreneurs and other major stakeholders in bringing about change and innovation, much less attention has been paid to the role of unorganized, nonstrategic actors—such as blogshops—in catalyzing retail change. The authors explore how blogshops are perceived by consumers and how they challenge the power of other shopping formats. They use Principal Components Analysis to analyze results from a survey of 349 blogshops users. While the results show that blogshops stay true to traditional online shopping attributes, deviations occur on the concept of value. Furthermore, consumer power is counter intuitively found to be strongly present in the areas related to cultural ties, excitement, and search for individualist novelty (as opposed to mass-production), thereby encouraging researchers to think critically about emerging power behavior in media practices.

Construct Validity and Reliability of Scores on Scales to Measure the Impairment of Health-Related Quality of Life in Persons With Asthma

2004 ◽  
Vol 12 (1) ◽  
pp. 21-31 ◽  
Author(s):  
Heibatollah Baghi ◽  
Martin Atherton
Keyword(s):  
Quality Of Life ◽  
Construct Validity ◽  
Principal Components Analysis ◽  
Principal Components ◽  
Primary Care Physicians ◽  
Health Related Quality ◽  
Related Quality ◽  
Health Related ◽  
Components Analysis

The purpose of this study was to test the reliability, validity, and effectiveness of a health-related quality of life (HRQOL) instrument—the MiniAQLQ—among persons with asthma who were using a web-based intervention for guided self-management (www.MyAsthma.com). The MiniAQLQ was completed online in 1999 by 307 participants referred to www.MyAsthma.com by their primary care physicians. Construct validity of the MiniAQLQ was assessed by principal components analysis; reliability was estimated using Cronbach’s alpha coefficient; and differences in means between pretest and posttest were analyzed using paired t test. The analysis produced four empirically meaningful factors with reliability of scores ranging from 0.65 to 0.94. Participants reported significant improvement in HRQOL after participating in this intervention. The four factors (activities, symptoms, emotions, and environment) generated by the principal components analysis empirically supported the four domains used in the development of the MiniAQLQ. Scores for the four factors were internally consistent and assessed the distinct domains. The MiniAQLQ appears to be a psychometrically sound instrument for measuring HRQOL online among asthma patients who are participating in online interventions.

The Reliability and Validity of a Lithic Debitage Typology: Implications for Archaeological Interpretation

1998 ◽  
Vol 63 (4) ◽  
pp. 635-650 ◽  
Author(s):  
William C. Prentiss
Keyword(s):  
Principal Components Analysis ◽  
Principal Components ◽  
Raw Materials ◽  
Experimental Studies ◽  
Reliability And Validity ◽  
Reduction Behavior ◽  
Reduction Techniques ◽  
Lithic Reduction ◽  
Components Analysis

Sullivan and Rozen's (1985) debitage typology has been proposed as a method for measuring the effects of variation in lithic reduction by describing “distinctive assemblages.” This is in contrast to many traditional analytical methods oriented toward identifying the effects of lithic reduction techniques on individual flakes. Debate over the use of the typology has focused primarily on the ability of the typology to accurately measure variation in lithic reduction behavior, and secondarily on the role of experimental studies in archaeology. In this paper I present an analysis designed to estimate the reliability and validity of the typology. An experimental design is developed to permit data collection with minimal analyst induced random or systematic error. Principal components analysis and the coefficient theta demonstrate that the typology provides reliable or replicable results when applied to debitage assemblages of similar technological origin. Further principal components analysis suggests that the instrument is of limited utility in recognizing effects of variation in reduction activities associated with highly vitreous lithic raw materials. A means of expanding the typology and increasing its accuracy in archaeological pattern recognition is presented.

scholarly journals New Role of Thermal Mapping in Winter Maintenance with Principal Components Analysis

2014 ◽  
Vol 2014 ◽  
pp. 1-11 ◽  
Author(s):  
Mario Marchetti ◽  
Lee Chapman ◽  
Abderrahmen Khalifa ◽  
Michel Buès
Keyword(s):  
Principal Components Analysis ◽  
Principal Components ◽  
Numerical Models ◽  
Full Range ◽  
Climatic Conditions ◽  
Atmospheric Conditions ◽  
Verification Method ◽  
Thermal Mapping ◽  
Components Analysis

Thermal mapping uses IR thermometry to measure road pavement temperature at a high resolution to identify and to map sections of the road network prone to ice occurrence. However, measurements are time-consuming and ultimately only provide a snapshot of road conditions at the time of the survey. As such, there is a need for surveys to be restricted to a series of specific climatic conditions during winter. Typically, five to six surveys are used, but it is questionable whether the full range of atmospheric conditions is adequately covered. This work investigates the role of statistics in adding value to thermal mapping data. Principal components analysis is used to interpolate between individual thermal mapping surveys to build a thermal map (or even a road surface temperature forecast), for a wider range of climatic conditions than that permitted by traditional surveys. The results indicate that when this approach is used, fewer thermal mapping surveys are actually required. Furthermore, comparisons with numerical models indicate that this approach could yield a suitable verification method for the spatial component of road weather forecasts—a key issue currently in winter road maintenance.

Patterns of change in maternal–child discourse behaviors across repeated storybook readings

2003 ◽  
Vol 24 (3) ◽  
pp. 323-341 ◽  
Author(s):  
SUSAN A. MCDONNELL ◽  
SANDY FRIEL–PATTI ◽  
PAMELA ROSENTHAL ROLLINS
Keyword(s):  
Principal Components Analysis ◽  
Principal Components ◽  
Child Participation ◽  
Composite Variable ◽  
Rates Of Change ◽  
Maternal Scaffolding ◽  
Mother And Child ◽  
Components Analysis ◽  
Reading Session

Fourteen mother–child dyads were videotaped four times over 16 days as they repeatedly read an initially unfamiliar storybook. Videotapes were transcribed and a variety of discourse measures were coded for both mother and child. Principal components analysis was used to combine three maternal and three child variables into a single composite variable, engagement, which described levels and quality of maternal and child participation in extratextual interactions during the first reading session. Dyads with the highest levels of engagement during the first session showed the greatest rates of change for a number of discourse measures. Results are discussed in terms of maternal scaffolding approaches, child participation, the importance of context and the nature of the task, and implications for intervention.

scholarly journals PENGARUH KONFLIK KEAGENAN TERHADAP CORPORATE GOVERNANCE DAN KINERJA PERUSAHAAN

MAKSIMUM ◽  
2012 ◽  
Vol 1 (2) ◽  
pp. 109
Author(s):  
Wahyu Manuhara Putra
Keyword(s):  
Corporate Governance ◽  
Principal Components Analysis ◽  
Principal Components ◽  
Ownership Structure ◽  
Agency Conflicts ◽  
Agency Conflict ◽  
Corporate Governance Mechanisms ◽  
Different Dimensions ◽  
Components Analysis

Abstract This study aimed to test whether the Corporate Governance associated the Agent- Conflicts This research Used exploratory principal components analysis and kanonikal analysis on 6 individual governance variables to get the 5 factors representing different dimensions of corporate governance and treasures the agent, conflict firms based on 7 agency conflict proxies used in the literature. Results of analysis found that Companies with greater agency conflict has a mechanism for better corporate governance, in particular that the low ownership structure has a high impact on institutional ownership. Overall the result support the theory that the existence and role of corporate governance mechanisms on firm is a function of agency Conflict in the company. Keyword : Agency Conflicts, Corporate Governance, exploratory principal components analysis, kanonikal analysis

How distinct is ‘distinct quality’ of mood?

1997 ◽  
Vol 27 (2) ◽  
pp. 445-453 ◽  
Author(s):  
G. PARKER ◽  
J. ROUSSOS ◽  
K. EYERS ◽  
K. WILHELM ◽  
P. MITCHELL ◽  
...  
Keyword(s):  
Principal Components Analysis ◽  
Principal Components ◽  
Mood State ◽  
Quality Criterion ◽  
The Other ◽  
Clinical Feature ◽  
Melancholic Depression ◽  
Dsm Iv ◽  
Components Analysis

Background. The DSM-IV criteria for melancholia include the clinical feature ‘distinct quality’, defined as a mood state differing from that experienced in bereavement. Both propositions – its specificity to melancholia and its definition – remain problematical.Methods. We examine both propositions by analysing an adjective checklist completed by melancholic and non-melancholic depressed subjects, as well as by a bereaved sample. The checklist was refined by a principal components analysis to four scales – one assessing a general ‘mood’ severity or dysphoric dimension, and the other three assessing dimensions of ‘fatigue’, ‘numbness’ and ‘guilt’.Results. If the concept of ‘distinct quality’ has validity, we would require specificity of the refined qualitative constructs to melancholic depression. The ‘numbness’ component met that requirement, but only to a degree. While bereaved subjects did differ from those with melancholic depression on a number of our refined qualitative mood domains, such differences appeared more related to lower levels of depression in the bereaved sample.Conclusions. We argue for deleting the ‘distinct quality’ criterion from diagnostic checklists of melancholia until its definition has been improved, its utility demonstrated and its specificity to any depressive subtype established as having clinical significance.

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