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In an experiment on the emergence of communication networks, 48 groups, each consisting of 4 or 5 members, were randomly assigned to the cells of a 2 (high vs. low time pressure) 2 (high vs. low task complexity) factorial design and completed a decision-making task. The interpersonal dominance of each member was measured via the Dominance scale of the Personality Research Form (PRF). Results showed that members higher in dominance emerged as more central in the group communication network, both sending and receiving more messages than members lower in dominance. Group members correctly perceived that those higher in dominance participated more in discussion. Communication was more centralized in groups that worked on the low complexity task than in groups that worked on the high complexity task. Members correctly perceived that participation was more unequally distributed in more centralized groups. An anticipated interaction effect, with time pressure moderating the effect of task complexity, was not supported.

verthepastseveralyears,� muchhasbeenpresentedand� publishedabouttheenabling� relationshipthatmultivariate� modelling,� or�"chemometrics",� technologies� hashadwithNIRanalysis.�Manyofthese� worksdemonstratethefeasibilityof,�orlay� thefoundationfor,�variouspracticalapplica- tionsthatcouldprovidesubstantialbenefits� withrespecttocostsavings,�productqual- ity,�improvedsafetyandsecurity,�avoided� capitalexpenditureorenvironmentalim- pact. Inalltheeuphoriaof�"whatcouldbe",� what� oftengetsforgottenisthedifficultjourneyof� suchapplicationsfromacademicfeasibility� toeffectivedeployment.� Anoptimistwould� saythattherelativelackofpublicdisclosure� ofsuchdeploymentsisduetotheirpropri- etarynature,�especiallyinhighlycompetitive� industriesinwhichdisclosurecouldresult� inlossofcompetitiveadvantage.�Apessi- mistmightsaythatitisduetothepaucityof� actualNIR/chemometricsdeploymentsthat� areprovidingrealbenefits.� Inanycase,�itis� unfortunatethatmanyofthesestoriesare� nottold,�becauseeachofthemislikelyto� havetheirownspecialandentertainingmix� oftechnology,�politicsand�(yes)�drama. Thepurposeofthiscolumnistotellthe� storyofaspecificapplicationusingNIRand� chemometricstechnologythathasnotonly� beengoingonformorethan�14�years,�but� isalsostill�"aliveandwell". 1 �Thisstorywillbe� toldfromtheperspectiveofoneofthemain� characterswhotrulystruggledthroughit,� anditwillbecompletewithsuccesses,�fail- ures,�embarrassmentsandmistakes.� This� willhopefullyallowacandiddiscussionof� someofthetechnical,� socialandpolitical� issuesthat,�Ifeel,�standinthewayoffurther� advancementofthesetechnologiesbeyond� theircurrentscope. BeforeIsetthestage,� thereareseveral�

Robert Jacobs and Donald Campbell's generational paradigm was used to examine the effects of group decision rule and performance feedback on the extent to which use of the decision rule was maintained as groups underwent turnover in membership. Confederates initially established a norm regarding rule use: Half the groups began with a majority rule and half with a seniority-based dictatorial rule. Groups made decisions about hiring (fictitious) job applicants. Half the groups in each decision rule condition received feedback that their decisions were correct and half that their decisions were incorrect. Groups that began with majority rule continued to use the rule. Groups that began with seniority rule always changed the rule and always changed it to majority rule. Performance feedback had no effect on maintenance of the decision rule, although it influenced group members' perceptions of the decision process and feelings toward the senior member under seniority rule.

A new approach for collection of infrared spectral data from optically opaque materials is explored. This approach has previously been introduced in the literature and is known as transient infrared transmission spectroscopy (TIRTS). The front surface of a hot sample is transiently cooled with a jet of cold gas, and the ratio of the spectrum measured after cooling to that measured before cooling is shown to closely resemble a transmission spectrum. This report provides for a more theoretical understanding of the experiments than provided by previous workers, making use of unsteady-state heat flow calculations, harmonic oscillator modeling, and radiation transfer theory. Experimental data are collected from a solid polymer sample and two viscous liquid samples. The position of the spectral features for the emission measurements corresponds with transmission measurements, with some saturation of the more intense spectral features noted. Faster scanning instrumentation, proper pulse scan synchronization, or rotation of solid samples, as demonstrated by previous workers, may resolve the saturation problem.

The ability of near-infrared (NIR) spectroscopy, combined with principal component regression (PCR), to nondestructively determine the blend ratio of high-density polyethylene (HDPE) and low-density polyethylene (LDPE) in extruded films is demonstrated. Results indicate that the NIR spectrum in the region 2100 to 2500 nm can be used to determine the HDPE mass percentage of 60–80- μm-thick film samples to within 2.5%, over a range of 0 to 100%. NIR spectral effects from scattering are important for the determination of the HDPE % for HDPE contents above 50%, and spectral effects from changes in the methyl group concentration and perhaps the PE crystallinity are important for the determination of the HDPE % for HDPE contents below 50%. In addition, a large variation between the spectra of replicate samples, probably caused by variations in the degree or direction of molecular orientation in the samples, was observed.

This paper is about the use of artificial neural networks for multivariate calibration. We discuss network architecture and estimation as well as the relationship between neural networks and related linear and non-linear techniques. A feed-forward network is tested on two applications of near infrared spectroscopy, both of which have been treated previously and which have indicated non-linear features. In both cases, the network gives more precise prediction results than the linear calibration method of PCR.

In this work, the abilities of near-infrared diffuse reflectance (NIR) and transmittance (NIT) spectroscopy to noninvasively determine the protein, fat, and water contents of plastic-wrapped homogenized meat are evaluated. One hundred homogenized beef samples, ranging from 1 to 23% fat, wrapped in polyamide/polyethylene laminates, were used. Results of multivariate calibration and prediction for protein, fat, and water contents are presented. The optimal test set prediction errors (root mean square error of prediction, RMSEP), obtained with the use of the principal component regression method with NIR data, were 0.45, 0.29 and 0.50 weight % for protein, fat, and water, respectively, for plastic-wrapped meat (compared to 0.40, 0.28 and 0.45 wt % for unwrapped meat). The optimal prediction errors for the NIT method were 0.31, 0.52 and 0.42 wt % for protein, fat, and water, respectively, for plastic-wrapped meat samples (compared to 0.27, 0.38, and 0.37 wt % for unwrapped meat). We can conclude that the addition of the laminate only slightly reduced the abilities of the NIR and NIT method to predict protein, fat, and water contents in homogenized meat.

Near-infrared-FT-Raman spectroscopy can be used to nondestructively analyze reaction-injection-molded (RIM) Polyurethane elastomers. Unlike conventional 514.5-nm excitation, the 1064.1-nm excitation of NIR-FT-Raman spectroscopy does not produce significant sample fluorescence. In this work, the ability of NIR-FT-Raman spectroscopy to determine flex moduli of Polyurethane elastomers is evaluated. Comparisons are made between NIR-FT-Raman, dispersive Raman with 514.5-nm and 752-nm excitation, and NIR diffuse reflectance spectroscopy for Polyurethane analysis.

A method for correction of pathlength effects in near-infrared (NIR) spectra is presented. This method, called Pathlength Correction with Chemical Modeling (PLC-MC), requires the use of standards in which the chemistry varies but the pathlength remains constant. Principal Components Analysis (PCA) is used to model the chemical variations in the spectra of the standards. The PCA model can then be used to estimate the pathlength of a future sample from the spectrum of the sample. Theoretical and experimental comparisons of the PLC-MC correction method with the Multiplicative Scatter Correction (MSC) method indicate that the PLC-MC method is more accurate than the MSC method if spectral variability from chemical variations is large.

The ability of near-infrared (NIR) diffuse reflectance spectroscopy to perform rapid bulk composition analyses of poly(ether urethane urea) (PEUU) block copolymers is demonstrated. Six polymer samples with known elemental compositions were used to construct calibration models using the method of classical least-squares (CLS). Results indicate that NIR diffuse reflectance spectroscopy can determine hard-segment and soft-segment contents of the bulk polymers within 2.6% mass over a range of 31% mass. Errors in the calibrations were caused by nonrepresentative NIR sampling of the polymers and by the presence of side products in the polymers. NIR spectra of model hard- and soft-segment materials are used to assign NIR bands to specific functional groups in the polymers.

Second-overtone carbonyl bands at 1918 and 2036 nm in the near-infrared (NIR) spectrum are used to monitor the phase separation of poly(ether urethane urea) (PEUU) block copolymers at 100°C. Exact positions of urea and urethane carbonyl bands are determined by NIR spectroscopic analyses of model compounds in bulk and in dilute solution. Results indicate that the carbonyl groups in the copolymers are affected by two different structural processes that occur with annealing. A faster process causes an increase in the number of free urethane groups, and a slower process causes a decrease in the number of free urea and urethane carbonyl groups. Although several structural mechanisms can be used to describe these trends, more information is necessary to identify exact structural changes that occur with annealing.

Diffuse reflectance spectroscopy in the near-infrared (NIR) region (1100-2400 nm) was used to characterize the morphology of fibrous and bulk Polyethylene terephthalate) (PET). The method of Partial Least-Squares (PLS) was used to correlate NIR spectra of PET yarns with percent crystallinity. Standard error of prediction values for percent crystallinity in PET yarns are in the range of 2–3.5% crystallinity, and depended on the specific NIR spectral region used for analysis. Principal Components Analysis (PCA) was used to study the differences in NIR spectra of bulk PET samples that were crystallized at different temperatures. It was observed that NIR spectroscopy can detect changes in both intermolecular and intramolecular interactions in PET. The observed effect of crystallization temperature on the morphology of bulk PET is very similar to effects observed in earlier IR and thermal analyses. In addition, detection of moisture in bulk PET is demonstrated.

A commercial near-infrared (near-IR) Fourier transform (FT) spectrometer was modified to make remote reflectance measurements over a single optical fiber or pair of optical fibers. With the use of two low-hydroxyl fused-silica optical fibers and an InSb detector, the near-IR region from 0.92 to 2.15 μm was measurable. An InGaAs detector was used to obtain reflectance spectra over the region from 0.92 to 1.56 μm. With this detector, single-fiber reflectance and transmission measurements were possible and a variety of dual-fiber probe geometries could be easily employed. Dual-fiber geometries were used to enhance pathlength, to perform depth discrimination, and to make measurements without physical contact between the probe and the specimen. Potential applications and improvements are discussed.

Each of 48 subjects was presented with four hypothetical situations involving two persons, P and 0, and an impersonal attitude object, X, and asked to make up stories about them. Each situation described P and 0 as either liking or disliking one another and as having either positive or negative attitudes toward X. The stories that subjects made up revealed that they sometimes "misconstrued" the situations. In particular, their stories about situations involving agreement between P and 0 in their attitudes toward X often depicted P and 0 as being in disagreement or conflict with one another, especially when the situations also involved disliking between P and 0. These "misconstruals" represent a discrepancy between the way in which subjects actually interpret hypothetical P-O-X situations of the kind frequently used in studies of balance, and the way in which researchers intend for subjects to interpret the situations. When such misconstruals occur, it is difficult to make sense of the results of research on balance.

Near-infrared spectroscopy in the combination, first overtone, and second overtone regions is combined with the multivariate methods of Partial-Least-Squares (PLS) and Classical-Least-Squares (CLS) to provide calibrations for chemical components in ethylene-propylene-diene monomer (EPDM) terpolymers. EPDM samples with 1,4-hexadiene (HD) and ethylidene norbornene (ENB) diene monomers were used for this study. Because unknown interaction effects are present in the spectra of these materials, the PLS calibration method gives more accurate calibrations than the CLS method. PLS coefficient spectra and CLS reconstructed spectra obtained from the calibrations are used to determine the sources of the unknown spectral effects. Results indicate that the combination, first overtone, and second overtone regions of the spectrum can be used to determine ethylene and propylene concentrations in the terpolymers, and the combination region can be used to determine diene concentrations. The presence of intrachain and interchain interactions in the terpolymers is indicated by observation of CLS reconstructed spectra.

An index of wishful thinking—the tendency for a person's belief about a particular proposition or issue to accord with his or her feeling about the desirability of the issue-used inappropriately in previous studies is empirically compared with a seemingly more plausible but also inappropriate index, and with a more appropriate index derived from an approach suggested by Norman (1967). Results indicate that previous studies may have overestimated the extent of wishful thinking by individuals or even reported its existence when it did not, infact, occur.

Triads composed of subjects who were previously unacquainted with one another played a coalition game under one of three conditions. In the Liking Only condition, liking among the triad members was manipulated so that some members liked each other more than others, but each member had the same resources in the coalition game. In the Resources Only, condition, the triad members had different resources, but liking was not manipulated. In the Liking and Resources condition, liking was manipulated so that there were differences in the triad members' liking for one another, and the members had different resources in the coalition game. Liking had a significant effect on coalition formation when there were no differences in resources (Liking Only), and resources had a significant effect when there were no differences in liking (Resources Only). But when there were differences in both liking and resources, the effect of liking was overwhelmed and only resources had a significant effect on coalition formation.

The near-infrared spectra of complex molecules, especially those containing oxygen or nitrogen, are normally characterized by regions of broad absorption with no sharp features. This arises from the multitude of absorptions which will occur in a complex molecule and because of the peak-broadening effect of hydrogen bond formation. Sucrose is unusual in this respect, because the spectrum (Fig. 1) exhibits a narrow peak at 1440 nm. While the phenomenon has been known for some time, its identity has been a mystery to near-infrared spectroscopists.

Etude de la distribution des decisions de groupe en fonction de l'information recue sur la position des autres membres du groupe et de la regle adoptee: majorite ou unanimite. Quatre-vingt groupes de trois personnes ont pris trois decisions impliquant un choix parmi un certain nombre de solutions formant un continuum. La moitie des groupes devait prendre les decisions suivant la regle de la majorite, l'autre moitie suivant la regle de l'unanimite. Dans la moitie des groupes, les membres etaient informes des preferences de chacun; dans l'autre, ce n'etait pas le cas