Estimating willingness to pay for motorcycle helmet and its determinants through contingent valuation method.

Background: Helmet use has been introduced as one of the most highlighted strategies for preventing death and injury in motorcyclists. On the other hand, the cost of the helmet was introduced as a barrier to use. This study aimed at estimating the willingness to pay (WTP) of motorcyclists in Saqqez to buy and use safety helmets through the contingent valuation method (CVM).

Control of Uncertain High-Order Fully Actuated Strict-Feedback Systems: A Backstepping Approach With High-Gain Observer-Based Derivative Approximation.

In this article, a high-gain observer (HGO)-based differentiator is proposed to approximate the derivatives of the virtual control to ease the "explosion of complexity" problem in backstepping for the second-order strict-feedback systems (SOSFSs) and high-order strict-feedback systems (HOSFSs). Unlike the existing high-order command-filtered backstepping or extended dynamic surface control that needs to tune a large number of parameters, this proposed high-order HGO-based backstepping (HOHGOB) scheme can improve the derivative approximation performance by only tuning a single parameter, i.e.

The competence of nurses caring for COVID-19 patients regarding disaster management: Structural equation modeling of knowledge, attitude, and performance.

Background: The outbreak of COVID-19 as a global disaster has required nurses, as front-line providers of safe and quality care to patients with this disease, for proper disaster management to have a high level of competence, which demands an acceptable level of knowledge, attitude, and performance. Therefore, this study was conducted to model the relationship between knowledge, attitude, and performance with the competence of nurses caring for patients with COVID-19 regarding disaster management.

Methods: This descriptive-correlational study was conducted on 291 hospital nurses using the structural equation modeling approach in three provinces of Iran, including Kerman, Hormozgan, and Fars, from June to December 2021.

The Factor Structure and Generalizability of the Iranian Socioeconomic Status (SES) Questionnaire Administered in a Nationally Divergent Population.

Background: Measuring socioeconomic status (SES) as an independent variable is challenging, especially in epidemiological and social studies. This issue is more critical in large-scale studies on the national level. The present study aimed to extensively evaluate the validity and reliability of the Iranian SES questionnaire.

Adaptive Tracking Control for Underactuated Double Pendulum Overhead Cranes With Variable Cable Length.

Although the literature on control of overhead crane systems is extensive and relatively mature, there is still a need to develop strategies that can simultaneously handle factors such as the double pendulum effect, variable cable length, input saturation, input dead zones, and external disturbances. This article is concerned with adaptive tracking control for underactuated overhead cranes in the presence of the above-mentioned challenging effects. The proposed controller is composed of the following two components.