Romeo Negrea

Followers

Following

Public Views

Dr. Sumon Saha

Bangladesh University of Engineering & Technology

Adnene TLILI

ISET Nabeul

Fabio Cuzzolin

Oxford Brookes University

Amir Mosavi

German Research Center for Artificial Intelligence

Florentin Smarandache

University of New Mexico

Vahid Arbabi

University Medical Center Utrecht

Nasreen Kausar

Yildiz Technical University

Hadar Ben-Yoav

Ben Gurion University of the Negev

Marie Husková

Charles University, Prague

Jana Javornik

University of East London

InterestsView All (6)

Uploads

Papers by Romeo Negrea

Studies regarding the behavior of some species of Sedum under the stress conditions induced by roof culture

Lucrări Științifice, Universitatea de Științe Agricole Și Medicină Veterinară "Ion Ionescu de la Brad" Iași, Seria Horticultură, 2015

Testing the Trust Dimensions of Romanian Consumers in E-Commerce for Electronic and Household Appliances

ACTA TECHNICA NAPOCENSIS - Series: APPLIED MATHEMATICS, MECHANICS, and ENGINEERING, Feb 18, 2021

In this paper, we identified and correlated ten factors and five dimensions of Romanian consumer ... more In this paper, we identified and correlated ten factors and five dimensions of Romanian consumer trust in e-commerce platforms from Romania, when purchasing electronic and household appliances. The study carries out an analysis and synthesis of the specialized literature to establish the correct dimensions, in order to test the trust of Romanian consumers in e-commerce platforms, finalizing by designing a dedicated model. To verify this model, a questionnaire was configured, and the data were validated by conceptualizing the nominal logistics model for testing consumers trust, using the nnet package in the "R" software. This study is complementary to four previous models and focuses on identifying the size and dynamics of consumer confidence in e-commerce platforms.

Download

In vivo confocal microscopy quantification of reactive oxygen species: a working model in rat kidney

PubMed, 2017

Oxidative stress is a culprit responsible for the development of acute and chronic kidney disease... more Oxidative stress is a culprit responsible for the development of acute and chronic kidney diseases. We aimed to establish a working model for the dynamic in vivo assessment of reactive oxygen species (ROS) production in rat kidney. A randomized controlled study was performed in 36 adult male Wistar rats subjected to unilateral urinary obstruction (UUO) via ureteral ligation and compared to SHAM controls. Dihydroethidium (DHE) was injected in the femoral vein and in vivo confocal microscopy was performed in the 2nd, 6th and 10th day, respectively after surgery. Maximal ROS levels elicited by UUO were recorded on the 6th day. However, the absolute difference of the means of DHE fluorescence intensity between UUO and SHAM was the highest on the 10th day. Our working model can monitor ROS production at different time frames and our initial findings suggest that the surgery-related ROS levels decline after an initial increase in the first days, whereas the ones elicited by chronic ligation continue to raise.

Download

Using a Refined Attractive Quality Model for Assessing Students’ Requirements for a New University Online Application

INTED proceedings, Mar 1, 2018

Numerical approximation for backward stochastic differential equations

On the extension of Longstaff and Evans-Keef-Okunev models related to the pricing of zero-coupon bonds

Annals of the University of Craiova - Mathematics and Computer Science Series, 2005

Aspects of Forecasting for the European Automotive Industry

Advances in intelligent systems and computing, Nov 3, 2015

The present paper aims to identify specific mathematical models of consumer behavior in the Europ... more The present paper aims to identify specific mathematical models of consumer behavior in the European automotive industry in order to increase the forecast accuracy. Thus, industry specific supply chains can obtain valid information of future demand, in order to better scale their structures of production, thereby reducing costs and thus increasing the value provided to the customer, a beneficial approach for improving the competitiveness level attained on the global market. Using historical data on new car registrations in the EU, appropriate autoregressive models were identified for consumers’ behavior that can be used as real solutions to increase the accuracy of forecasts made in the industry.

Numerical Solutions for a Class of Backward Stochastic Differential Equations

ABSTRACT We propose a method for numerical approximation of the solutions of backward stochastic ... more ABSTRACT We propose a method for numerical approximation of the solutions of backward stochastic differential equations in some non-lipschitz conditions for the coefficient functions and without the condition of the continuity for the final data. Given a simulation-based estimator of the conditional expectation operator, we then suggest a backward simulation scheme. Our explicitly method is simple to implement and it relies on approximation of Brownian motion by simple random walk.

On a Class of Stochastic Integral Operators of McShane Type

Birkhäuser Basel eBooks, 2004

ABSTRACT The aim of this note is to give an extension of a result by McShane to a general stochas... more

On the pathwise uniqueness of solutions to stochastic differential equations

Journal of Differential Equations, May 1, 2023

On a class of nonlinear stochastic integral equations

Nonlinear Analysis-real World Applications, Aug 1, 2020

Abstract We prove some existence and uniqueness results for a nonlinear stochastic integral equat... more

On backward stochastic differential equations and control of electronic circuits

Our goal is to give a continuous model for the control of electronic circuits with stochastic per... more Our goal is to give a continuous model for the control of electronic circuits with stochastic perturbations using the backward stochastic differential equations. Some aspects of the solutions of these equations are studied for general conditions of the coefficient functions and the initial value. The control is on the benefit of stochastic resonance for non-linear circuits, and some numerical examples are presented.

Testing the Trust of Romanian Consumers in E-Commerce

Springer proceedings in business and economics, 2020

On a nonlinear stochastic integral equation

Monatshefte für Mathematik, Jan 17, 2020

We prove some existence and uniqueness results for nonlinear stochastic integral equation of Urys... more We prove some existence and uniqueness results for nonlinear stochastic integral equation of Urysohn type using fixed point theory methods. We also establish the stability of the unique solution with respect to small perturbations of the stochastic free term (Constantin, Qualitative problems for differential equations and control theory, World Scientific Publishing, Singapore, 1995).

Download

A strategic decision making tool for new product and service design

Management Decision, Apr 17, 2020

Purpose-The present study aims to further research the theory of attractive quality for new offer... more Purpose-The present study aims to further research the theory of attractive quality for new offers by analyzing the HWWP (Health, Weapon, Wealth, Prospect) model and testing its uniformity. The purpose is to extend and refine the HWWP model based on meridian elasticity curves with the final scope of building a map for better understanding the potential value of the quality attributes in new product or strategic service design. Design/methodology/approach-After a thorough analysis of the HWWP model for prepurchase value judgment, it has been observed that the classical form often presents a concentration of the quality attributes in its graphic representation, which limits managerial decision making. This paper presents a new methodology for testing the uniformity of the current HWWP model and a generalized approach for understanding the potential lifecycle of the new offer's features. Findings-The results of the presented case study validate the novel tool's applicability and can serve as a reference for managers to adequately classify customer requirements as the first step toward strategic design. Originality/value-The author's main contributions are: to have analyzed the current HWWP model and observed the limitations of this approach; to have proposed a statistical simple method used to test the uniformity of the HWWP model; to have developed a generalized new HWWP model that adequately explores each feature value and potential lifecycle base on meridian slices and elasticity orbits.

Download

Controlling Stochastic Resonance in an Electronic Circuit with non-Gaussian Perturbations

In this paper, we consider a nonlinear electronic circuit which is affected by the general extern... more In this paper, we consider a nonlinear electronic circuit which is affected by the general external noises such as Levy or truncated Levy noises. The problem of the controlling stochastic resonance in this case, can be solves using the approach of state space representation for a time series. A computational algorithm and some numerical examples are presented.

On a class of backward stochastic differential equations and applications to the stochastic resonance

ABSTRACT We establish a new theorem on the existence and uniqueness of the adapted solution to a ... more ABSTRACT We establish a new theorem on the existence and uniqueness of the adapted solution to a backward stochastic differential equation under some weaker conditions than the Lipschitz one. The extension is based on the Athanassov non-Lipschitz condition for ordinary differential equations. Also, some stability properties of the solutions are given.

Customer Perspective of Value for Innovative Products and Services

Procedia - Social and Behavioral Sciences, 2018

Innovation is an important competitive advantage for market success. Faster, cheaper, better are ... more Innovation is an important competitive advantage for market success. Faster, cheaper, better are the keywords of the current competitive environment. For this to occur, products and services need to address customer needs in such a way as to fulfil what they expect but in the same time delight them through unexpected and attractive features. The theory of attractive quality uses the Kano methodology, a value components model, when thinking about product features in this way. Unfortunately, the Kano questionnaire mainly analyses customer satisfaction regarding an existing offer, thus a post purchase evaluation. In the case of new and innovative products or services, we do not have prior consumer value or a "standard" to compare it with. Therefore, we must rely on pre-purchase judgment. But what is desired customer value and with what concepts should it be associated with? The present paper aims to delimit customer value pre-purchase perception from post-purchase perception and determine the terms and key words which best represent the customer's perspective in this situation. The ultimate goal is to present a first conceptual step into the development of an alternative to the Kano model for the design stage of innovative products and services.

Download

An Application of Schauder's Fixed Point Theorem in Stochastic McShane's Modelling

The aim of this work is to establish an existence theorem for solutions of Mc-Shane's stochastic ... more The aim of this work is to establish an existence theorem for solutions of Mc-Shane's stochastic systems, applying Schauder's fixed point theorem. Also, we give new conditions relative to the coefficients for the continuity of solution with respect to the initial condition and respectively, the problem of parametric dependence of the solution process on the coefficients in McShane stochastic integral equations, generalizing the results of [1], [3], [4]. A short comment on continuous dependence of the solution on the disturbance and on modelling problems is given.

Download

Applying Six Sigma Methodology in the Automotive Industry

Springer proceedings in business and economics, 2020

The Six Sigma methodology improved the way in which we think about performance. It represents a s... more The Six Sigma methodology improved the way in which we think about performance. It represents a step forward towards data-driven processes and decision making based on measurement and analysis. It lowers the risk of unintended consequences and the money wrongly spent. The DMAIC model presents a five-phase project layout with a wide range of tools, a simple problem-solving method for improving speed, quality and of course, cost. The present research presents a case study from the automotive industry in which an observed problem is validated as a DMAIC project and taken through the methodology for a steady and well-documented improvement that stays in place due to continuous monitoring.

Studies regarding the behavior of some species of Sedum under the stress conditions induced by roof culture

Lucrări Științifice, Universitatea de Științe Agricole Și Medicină Veterinară "Ion Ionescu de la Brad" Iași, Seria Horticultură, 2015

Testing the Trust Dimensions of Romanian Consumers in E-Commerce for Electronic and Household Appliances

ACTA TECHNICA NAPOCENSIS - Series: APPLIED MATHEMATICS, MECHANICS, and ENGINEERING, Feb 18, 2021

Download

In vivo confocal microscopy quantification of reactive oxygen species: a working model in rat kidney

PubMed, 2017

Download

Using a Refined Attractive Quality Model for Assessing Students’ Requirements for a New University Online Application

INTED proceedings, Mar 1, 2018

Numerical approximation for backward stochastic differential equations

On the extension of Longstaff and Evans-Keef-Okunev models related to the pricing of zero-coupon bonds