Search results for "SAMPLE"

Evaluation of the use of wavefront encoding to reduce depth-induced aberration in structured-illumination microscopy

2018

Three-dimensional imaging is affected by depth-induced spherical aberration (SA) when imaging deep into an optically thick sample. In this work, we evaluate the impact of SA on the performance of incoherent grating-projection structured illumination microscopy (SIM). In particular, we analyze the reduction of the contrast in the structured pattern and compare the reconstructed SIM images for different amounts of SA. In order to mitigate the impact of SA, we implement and evaluate in SIM a wavefront encoded imaging system using a square cubic (SQUBIC) phase mask, an approach shown previously to be successful in conventional microscopy.

What are the relationships among Web 2.0, market orientation and innovativeness?

2013

PurposeFirms are adopting Web 2.0 technologies to improve collaboration, participation and communication; however there are few empirical studies testing the impact of this adoption. The purpose of this article is to analyze if there is a linkage amongst market orientation, Web 2.0 adoption and innovativeness.Design/methodology/approachStructural equation modeling was used to test the relationships amongst the variables. A sample of 244 firms of the hospitality industry was used. The theoretical approach is based on the market orientation and innovativeness, concepts, which have been studied by various authors in the literature.FindingsA positive relationship was found between market orient…

COMPARISON OF EXPERIMENTS WITH WEIGHTED DISTRIBUTIONS

1989

In this paper the standard statistical experiment in which a random sample is drawn from some distribution involving an unknown parameter θ is compared with experiments in which samples are obtained from different weighted versions of that distribution, so that the underlying probability of entering the sample is multiplied by some weight function. This comparison is carried out by means of the concepts of sufficiency and pairwise sufficiency as developed in Blackwell's theory of the comparison of statistical experiments. Many examples are presented which illustrate the wide variety of effects that weight functions can have on the information about θ.

Restricted Decontamination for the Imbalanced Training Sample Problem

2003

The problem of imbalanced training data in supervised methods is currently receiving growing attention. Imbalanced data means that one class is much more represented than the others in the training sample. It has been observed that this situation, which arises in several practical domains, may produce an important deterioration of the classification accuracy, in particular with patterns belonging to the less represented classes. In the present paper, we report experimental results that point at the convenience of correctly downsizing the majority class while simultaneously increasing the size of the minority one in order to balance both classes. This is obtained by applying a modification o…

High Performance Liquid Chromatography Analysis of Grape and Wine Polyphenols

2008

Wine list engineering: categorization of food and beverage outlets

2009

PurposeThe purpose of the paper is to identify and measure the main standards of the wine lists of upscale restaurants.Design/methodology/approachWine lists of a sample of 50 upscale restaurants were analyzed. A cluster analysis was performed.FindingsThree differentiated profiles of restaurants are identified according to their wine list management: selection, specialization and complementarity.Research limitations/implicationsThis study was exploratory and similar studies need to be performed covering more geographic locations.Practical implicationsRestaurants differ in their current practices and key standards of their wine lists according to their positioning strategy. Upscale restaurant…

Comparison of different sample treatments for the analysis of ochratoxin A in must, wine and beer by liquid chromatography.

2004

Abstract Ochratoxin A (OTA) is a mycotoxin produced by some species of Aspergillus and Penicillium verrucosum. It has been found in foods and feed all over the world. There is a great concern about OTA because it is nephrotoxic and probably, carcinogenic to humans. Most of analytical methods developed for OTA in wine, beer and other products are based on LC with fluorescence detection (LC–FLD). In the present work, various procedures for extraction and/or clean-up for determination of OTA in musts, wine and beer by LC–FLD were compared: (1) dilution with polyethylen glycol 8000 and NaHCO3 solution and clean-up an on immunoaffinity column (IAC); (2) extraction with chloroform and IAC clean-u…

Searching the most appropriate sample pretreatment for the elemental analysis of wines by inductively coupled plasma-based techniques.

2008

Different sample preparation methods were evaluated for the simultaneous multielement analysis of wine samples by inductively coupled plasma optical emission spectrometry (ICP-OES) and inductively coupled plasma mass spectrometry (ICP-MS). Microwave-assisted digestion in closed vessel, thermal digestion in open reactor, and direct sample dilution were considered for the determination of Li, Be, Na, Mg, Al, K, Ca, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Se, Sr, Y, Mo, Cd, Ba, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Tl, Pb, and Bi in 12 samples of red wine from Valencia and Utiel-Requena protected designation of origin. ICP-MS allows the determination of 17 elements in most…

Overdispersion tests in count-data analysis.

2008

Count data are commonly assumed to have a Poisson distribution, especially when there is no diagnostic procedure for checking this assumption. However, count data rarely fit the restrictive assumptions of the Poisson distribution. The violation of much of such assumptions commonly results in overdispersion, which invalidates the Poisson distribution. Undetected overdispersion may entail important misleading inferences, so its detection is essential. In this study, different overdispersion diagnostic tests are evaluated through two simulation studies. In Exp. 1, the nominal error rate is compared under different sample sizes and Λ conditions. Analysis shows a remarkable performance of the χ…

Influence of Social Networks from Cellphones to Choose Restaurants, Salinas – 2016

2018

Inclusion of technology as part of business strategies has made consumers have other tools that help them to find information and making consumer decisions. It is here the importance of knowing influence of comments have in social networks in taking decisions of visits to restaurants. For this work, a qualitative method (focal group) was used in the first part and then a quantitative method was used (off line and online survey). The sample for focal group was made up by Equinoctial Technological University’s students in Santa Elena, the same ones belonged to the careers of Finance and Audit (7 students), Business and Business (1 student) and 2 graduates of the Finance and Audit. An experime…