Biplots of fuzzy coded data

A biplot, which is the multivariate generalization of the two-variable scatterplot, can be used to visualize the results of many multivariate techniques, especially those that are based on the singular value decomposition. We consider data sets consisting of continuous-scale measurements, their fuzzy coding and the biplots that visualize them, using a fuzzy version of multiple correspondence analysis. Of special interest is the way quality of fit of the biplot is measured, since it is well-known that regular (i.e., crisp) multiple correspondence analysis seriously under-estimates this measure. We show how the results of fuzzy multiple correspondence analysis can be defuzzified to obtain estimated values of the original data, and prove that this implies an orthogonal decomposition of variance. This permits a measure of fit to be calculated in the familiar form of a percentage of explained variance, which is directly comparable to the corresponding fit measure used in principal component analysis of the original data. The approach is motivated initially by its application to a simulated data set, showing how the fuzzy approach can lead to diagnosing nonlinear relationships, and finally it is applied to a real set of meteorological data.defuzzification, fuzzy coding, indicator matrix, measure of fit, multivariate data, multiple correspondence analysis, principal component analysis.

Learning by doing as a human capital factor: Case of Eskisehir furniture manufacturing sector

This study seeks to determine the impacts of learning by doing, human capital and R&D factors on firm’s output by using simultaneous equations system. In this study, medium and large-sized companies from furniture manufacturing sector in Eskisehir, Turkey are selected as the research domain and a database is generated based on the information collected through face-to-face interviews with company executives (or with officials designated by them), the financial statements of researched companies, and the records of Eskisehir Chamber of Industry. According to the estimation results obtained, the human capital stock, learning by practice phenomenon and the research and development expenditures have a linear impact on the company's total output. It is understood that, fixed capital stock and size of company become prominent in terms of their impact on the human capital, and the mentioned variables demonstrate a positive relation with the output. Likewise, the linear relationship between learning by practice and company size as well as wage level; and between research & development expenditures and company size are the factors that come forth in the explanation of the dependent variables

Biplots of fuzzy coded data

A biplot, which is the multivariate generalization of the two-variable scatterplot, can be used to visualize the results of many multivariate techniques, especially those that are based on the singular value decomposition. We consider data sets consisting of continuous-scale measurements, their fuzzy coding and the biplots that visualize them, using a fuzzy version of multiple correspondence analysis. Of special interest is the way quality of fit of the biplot is measured, since it is well-known that regular (i.e., crisp) multiple correspondence analysis seriously under-estimates this measure. We show how the results of fuzzy multiple correspondence analysis can be defuzzified to obtain estimated values of the original data, and prove that this implies an orthogonal decomposition of variance. This permits a measure of fit to be calculated in the familiar form of a percentage of explained variance, which is directly comparable to the corresponding fit measure used in principal component analysis of the original data. The approach is motivated initially by its application to a simulated data set, showing how the fuzzy approach can lead to diagnosing nonlinear relationships, and finally it is applied to a real set of meteorological data

_

A biplot, which is the multivariate generalization of the two-variable scatterplot, can be used to visualize the results of many multivariate techniques, especially those that are based on the singular value decomposition. We consider data sets consisting of continuous-scale measurements, their fuzzy coding and the biplots that visualize them, using a fuzzy version of multiple correspondence analysis. Of special interest is the way quality of fit of the biplot is measured, since it is well-known that regular (i.e., crisp) multiple correspondence analysis seriously under-estimates this measure. We show how the results of fuzzy multiple correspondence analysis can be defuzzified to obtain estimated values of the original data, and prove that this implies an orthogonal decomposition of variance. This permits a measure of fit to be calculated in the familiar form of a percentage of explained variance, which is directly comparable to the corresponding fit measure used in principal component analysis of the original data. The approach is motivated initially by its application to a simulated data set, showing how the fuzzy approach can lead to diagnosing nonlinear relationships, and finally it is applied to a real set of meteorological data

Sampling frame coverage and domain adjustment procedures for internet surveys

The objective of this paper is to define and compare alternative sampling frames for the representative population coverage as a basis for sample selection in internet surveys. The study aims to provide a methodology for domain weighting and adjustment procedures for free access web surveys that are based on the restricted access surveys. Some basic variables can be proposed for the data adjustment, namely gender breakdown, age groups, and education groups. The application of our work consists of a first stage based on a web survey by an e-mail invitation (restricted access) and a second stage based on a voluntary participation web survey (free access). An advertising company's registered customer list was taken as the sampling frame population for the first stage. This frame was an electronic e-mail list of the population of registered customers. Two different types of questionnaire were loaded on the company's internet web site for a month each, for two independent rounds, for testing the visual aspects of the questionnaire design. The restricted access internet survey design relies on probability selection procedures in this study. These results are used with the provided algorithms for the adjustment procedures of free access web surveys. A new methodology is also proposed for the estimation and allocation of the population frame characteristics of adult internet users by gender and age groups. The proposed alternative methodologies will be beneficial tools for future web survey users

COMPARASION OF TWO DIFFERENT RESPONDENT GROUPS WITH WEB QUESTIONNAIRE SURVEY BASED ON WEB

Studies about Web surveys are carried on computers by visitors surfing web page and e-mail addresses. In this study, a web site with a membership service is determined and a survey form with two different designs is planned to carry, as a pilot survey, on anonymous visitors and members using their e-mail addresses of this web site. Responses of two different respondent groups for the same topic in same survey form are statistically compared. The survey is carried on each one of anonymous visitors and members of this web site by their e-mail addresses for one month. 102 anonymous visitors and 100 members by e-mail participated in the survey. In the survey, altitude questions about update level of the web site and personal questions are asked to respondents. In the conducted survey, it is seen that generally responds of the each of the respondent groups to altitude questions are determined as statistically different, but both of the respondent groups are pleased with usage of relevant web site and design of the survey form. According to the result of conducting the same survey study on the same web site, it can be said that visitors of the relevant web site and with known e-mails group determined by using probability sampling are really different. However, repetition of this study according to time which may increase the sample sizes, affect on the results.Web Questionnaire, e-mail Questionnaire

Adrenocortical hormone profiles do not predict the molecular etiology in non-CAH primary adrenal insufficiency

Background: Primary adrenal insufficiency other than congenital adrenal hyperplasia (non-CAH PAI) is very uncommon in children but associated with a variety of molecular defects. Biosynthesis of adrenocortical hormones is reduced although the relation of steroid profiles with underlying molecular etiology is not yet studied. Objective: Investigation of clinical and steroid hormone profiles of a multicenter cohort of children with non-CAH PAI. Design: Patients with CAH, adrenoleukodystrophy, autoimmune adrenal insufficiency or obvious syndromic PAI on clinical and biochemical assessment were excluded. Genetic analysis was performed using either targeted gene panel or whole-exome sequencing. Plasma adrenal steroids were quantified by liquid chromatography-mass spectrometry and compared to that of controls. Setting: Sixteen tertiary pediatric endocrinology clinics. Patients: Forty-one children (19 females, median age: 3 months, range: 0-8 years) with non-CAH PAI of unknown etiology. Results: A genetic diagnosis was obtained in 29 (68%) patients by targeted gene panel. Further molecular diagnosis could not be achieved by WES. The range of etiologies was: MC2R (n = 6), StAR (n = 6), NNT (n = 3), NR0B1 (n = 3), CYP11A1 (n = 2), MRAP (n = 2), SGPL1 (n = 2), ABCD1 (n = 1), AIRE (n = 1), AAAS (n = 1), HSD3B2 (n = 1). Steroid profiling demonstrated low levels in all adrenocortical steroid hormones irrespective of age and not varied among the genetic etiologies except two patients with new-onset symptoms of PAI due to homozygous c.518T>A(p.Leu173Gln) SGPL1, and hemizygous c.1772G>T(p.Arg591Leu) ABCD1 defects, and another patient with non-classic non-CAH PAI due to homozygous c.1351C>T (p.Arg451Trp) variant in CYP11A1. Compared to age-matched healthy control group in whom steroid hormone concentrations are physiologically low, the patient group had even lower steroid concentrations, most significantly in cortisone, cortisol, and corticosterone (P 95% specificity to segregate non-CAH PAI patients compared to control groups. Conclusion: Adrenocortical hormone profiles are highly sensitive for the diagnosis of non-CAH PAI, while, in contrast to CAH, they are unlikely to point out a specific molecular diagnosis. Targeted gene panel sequencing is an undisputed optimal approach in the molecular diagnosis of non-CAH PAI with low cost and high efficacy, while little additional benefit is expected from whole-exome sequencing. Further progress can be made, mainly by more collaboration and exchanging knowledge for delineation of rare causes of primary adrenal insufficiency

Steroid hormone profiles and molecular diagnostic tools in pediatric patients with non-CAH primary adrenal insufficiency

CONTEXT: There is a significant challenge of attributing specific diagnoses to patients with primary adrenal insufficiency of unknown etiology other than congenital adrenal hyperplasia (non-CAH PAI). Specific diagnoses per se may guide personalized treatment or may illuminate pathophysiology. OBJECTIVE: This work aimed to investigate the efficacy of steroid hormone profiles and high-throughput sequencing methods in establishing the etiology in non-CAH PAI of unknown origin. METHODS: Pediatric patients with non-CAH PAI whose etiology could not be established by clinical and biochemical characteristics were enrolled. Genetic analysis was performed using targeted-gene panel sequencing (TPS) and whole-exome sequencing (WES). Plasma adrenal steroids were quantified by liquid chromatography-mass spectrometry and compared to that of controls. This study comprised 18 pediatric endocrinology clinics with 41 patients (17 girls, median age: 3 mo, range: 0-8 y) with non-CAH PAI of unknown etiology. RESULTS: A genetic diagnosis was obtained in 29 (70.7%) patients by TPS. Further molecular diagnosis could not be achieved by WES. Compared to a healthy control group, patients showed lower steroid concentrations, most statistically significantly in cortisone, cortisol, and corticosterone (P < .0001, area under the receiver operating characteristic curve: .96, .88, and .87, respectively). Plasma cortisol of less than 4 ng/mL, cortisone of less than 11 ng/mL, and corticosterone of less than 0.11 ng/mL had a greater than 95% specificity to ensure the diagnosis of non-CAH PAI of unknown etiology. CONCLUSION: Steroid hormone profiles are highly sensitive for the diagnosis of non-CAH PAI of unknown etiology, but they are unlikely to point to a specific molecular diagnosis. TPS is an optimal approach in the molecular diagnosis of these patients with high efficacy, whereas little additional benefit is expected from WES