Search results for "multiple regression"
showing 10 items of 12 documents
Plant structure as a determinant of coriander (Coriandrum sativum L.) seed and straw yield
2020
Abstract Coriander (Coriandrum sativum L., Apiaceae) is a Mediterranean aromatic plant that is mainly cultivated for its fruits. Understanding the association between various vegetative and reproductive structures as they pertain to yield can help addressing efforts for achieving the highest productivity levels, by improving both cropping techniques and breeding. Multiple Regression (MR) analysis is a suitable tool to understand this association; notwithstanding, due to the plant’s inherent “weedy” growth, the interpretation of MR results in coriander is often difficult. Therefore, in our analysis we also calculated additional indicators of variable contribution to the model and to one anot…
Factors associated with efficacy of an ibuprofen/pseudoephedrine combination drug in pharmacy customers with common cold symptoms
2016
SummaryAim The aim of this study was to explore factors affecting efficacy of treatment of common cold symptoms with an over-the-counter ibuprofen/pseudoephedrine combination product. Methods Data from an anonymous survey among 1770 pharmacy customers purchasing the combination product for treatment of own common cold symptoms underwent post-hoc descriptive analysis. Scores of symptoms typically responsive to ibuprofen (headache, pharyngeal pain, joint pain and fever), typically responsive to pseudoephedrine (congested nose, congested sinus and runny nose), considered non-specific (sneezing, fatigue, dry cough, cough with expectoration) and comprising all 11 symptoms were analysed. Multiple…
Foreign Direct Investment Drivers in Romania
2013
Foreign Direct Investment (FDI) represents a condition sine qua non for a sustainable development of Romania, taking into consideration the fact that the domestic capital is not enough to assure a positive and significant growth. The present study uses the multiple linear regression to determine the main factors which influence FDI level in Romania. The international reserve and the capital market index BET have a direct and positive impact on the foreign investment flow, while the short, medium and long private and public external debt proved to influence direct, but in a negative way, the FDI.
Factors Influencing Soil Organic Carbon Stock Variations in Italy During the Last Three Decades
2010
Soils contain about three times the amount of carbon globally available in vegetation, and about twice the amount in the atmosphere. However, soil organic carbon (SOC) has been reduced in many areas, while an increase in atmospheric CO2 has been detected. Recent research works have shown that it is likely that past changes in land use history and land management were the main reasons for the loss of carbon rather than higher temperatures and changes of precipitation resulting from climate change. The primary scope of this work was to estimate soil organic carbon stock (CS) variations in Italy during the last three decades and to relate them to land use changes. The study was also aimed at f…
An integrated analysis of land market in an inland area of Sicily
2013
In this study a land market analysis of the 22,000 hectares covered by Corleone town area for the 2007-2012 period was carried out. Data on 372 sales agreements concerning agricultural and building land were directly collected from notaries' offices. Over 50% of land sales concerned land areas below 0.50 hectares, whereas just 1% of the overall land sold was larger than 10 hectares. Nearly 75% of sample observations were represented by land sales smaller than 1 hectare. The average land area per purchase was just over 1 hectare. The overall money exchanged in the whole period amounted to nearly 6 million euro, with an average price per sale equal to 16,339.45 (sic), and an average unitary p…
THE USE OF REGRESSION ANALYSIS IN MARKETING RESEARCH
2012
The purpose of the paper is to illustrate the applicability of the linear multiple regression model within a marketing research based on primary, quantitative data. The theoretical background of the developed regression model is the value-chain concept of relationship marketing. In this sense, the authors presume that the outcome variable of the model, the monetary value of one purchase, depends on the clients’ expectations regarding seven dimensions of the company’s offer. The paper is structured in two parts. In the first part, a brief literature review enumerates the main multivariate data analysis methods used in marketing research and describes the general linear multiple regression mo…
Validation of bioelectrical impedance analysis for estimating limb lean mass in free-living Caucasian elderly people
2017
Background & aims Aging is characterized by a loss of limb lean mass (LLM) that can lead to physical disability and death. Regional bioelectrical impedance analysis (BIA) may be a reliable method for estimating LLM, but no prediction equations are available for elderly Caucasian subjects. The aim of this study was to develop and validate a BIA-based equation for predicting LLM in healthy elderly Caucasians, taking dual X-ray absorptiometry (DXA) as the reference method. Methods Using a cross-sectional design, 244 free-living healthy Caucasian subjects (117 men, 179 women) over 60 years of age were enrolled. LLM was measured with DXA (LLMDXA), and the resistance (Rz) and reactance (Xc) o…
Assessing appendicular skeletal muscle mass with bioelectrical impedance analysis in free-living Caucasian older adults
2015
Background & aims: Aging is characterized by a loss of appendicular skeletal muscle mass (ASMM) leading to physical disability and death. Bioelectrical impedance analysis (BIA) is reliable in estimating ASMM but no prediction equations are available for elderly Caucasian subjects. The aim of the study was to develop and validate an equation derived from bioelectrical impedance analysis (BIA) to predict appendicular skeletal muscle mass (ASMM) in healthy Caucasian elderly subjects, taking dual X-ray absorptiometry (DXA) as the reference method, and comparing the reliability of the new equation with another BIA-based model developed by Kyle etal. (Kyle UG, Genton L, Hans D, Pichard C, 200…
Clinical and biochemical determinants of the extent of liver steatosis in type 2 diabetes mellitus
2015
Objective Nonalcoholic fatty liver disease is very frequent in both type 2 diabetes mellitus (T2DM) and the metabolic syndrome (MS), which share clinical and metabolic characteristics. Whether and to which extent these characteristics can predict the degree of liver steatosis are not entirely clear. Patients and methods We determined liver fat (divided into four classes) by standard sonographic images, and clinical and biochemical variables, in 60 consecutive patients with T2DM and with features of the MS. We examined both simple and multiple correlations between the degree of liver steatosis and the variables measured. Results Increased liver fat (defined as >5% of liver mass) was detec…
On the sign recovery by LASSO, thresholded LASSO and thresholded Basis Pursuit Denoising
2020
Basis Pursuit (BP), Basis Pursuit DeNoising (BPDN), and LASSO are popular methods for identifyingimportant predictors in the high-dimensional linear regression model Y = Xβ + ε. By definition, whenε = 0, BP uniquely recovers β when Xβ = Xb and β different than b implies L1 norm of β is smaller than the L1 norm of b (identifiability condition). Furthermore, LASSO can recover the sign of β only under a much stronger irrepresentability condition. Meanwhile, it is known that the model selection properties of LASSO can be improved by hard-thresholdingits estimates. This article supports these findings by proving that thresholded LASSO, thresholded BPDNand thresholded BP recover the sign of β in …