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This paper aims to propose an analytical method for designing parametric optimization-based proportional integral (PI) controllers.

In this method, a performance index containing the weighted summation of the integral square of the error and its derivative is minimized. This performance index is analytically calculated in terms of the controller parameters by solving a Lyapunov equation. Then partial derivatives of the performance index with respect to controller parameters are calculated. Equating these partial derivatives to zero gives explicit relations for the PI controller parameters.

The experimental tests on a DC servomotor system are given to demonstrate the efficiency of the proposed method.

This paper proposes an analytical parametric optimization approach for designing PI controllers for the first time. The application of the proposed method in a laboratory experiment is examined.

Tourism industry is a profitable resource for countries and considered one of the main sources of income and job creation for economic development. Among the various types of tourism, medical tourism and its subsets are of great significance owing to their capabilities and competitive advantages. In this regard, the purpose of this research is to provide a framework to categorize customers based on the Zeithaml pyramid and then identify and provide strategies to create loyalty and attract customers of this industry.

This study proposed a framework for medical tourists' satisfaction and loyalty. First, by studying the literature and data gathering from Yazd (one of the cities of Iran), the effective factors on the loyalty and attraction of medical tourists were identified. These factors have been prioritized for the medical tourists who are in the platinum category by the Pareto technique and Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS) method. Next, the strategies provided by experts for loyalty and attraction of medical tourists were examined. Finally, the house of quality (HOQ) as the first matrix in quality functional deployment (QFD) was used to provide operational strategies for medical tourism satisfaction. The statistical population of this research consists of medical tourists, academic experts and active physicians of medical tourism in Yazd, one of the cities of Iran.

The study results indicate the importance of “hospital reputation” in medical tourists' satisfaction. Also, “achieving international standards”, “periodic customer satisfaction assessment” and “paying attention to social responsibilities” are recognized as the most important strategies to achieve the loyalty of the most profitable group of customers, namely platinum.

This study covers both theoretical and practical aspects. Theoretically, this study developed a new framework for medical tourists' satisfaction by the Zeithaml matrix, TOPSIS, Pareto technique and QFD method. Furthermore, practically this study helps practitioners of medical tourism in medical tourists' satisfaction and loyalty.

In this study, in addition to identifying the effective factors on the loyalty and attracting medical tourists, a new framework was developed for medical tourists' satisfaction by segmentation the tourism by the Zeithaml matrix and providing operational strategies by the QFD technique.

The purpose of this paper is to present a two-loop approach for velocity control of a permanent magnet synchronous motor (PMSM) under mechanical uncertainties.

The inner loop calculates the two-axis stator reference voltages through a feedback linearization method. The outer loop employs an RST control structure to compute the q-axis stator reference current. To increase the robustness of the proposed method, the RST controller parameters are adapted through a fractional order model reference adaptive system (FO-MRAS). The fractional order gradient and Lyapunov methods are utilized as adaptation mechanisms.

The effect of the fractional order derivative in the load disturbance rejection, transient response speed and the robustness is verified through computer simulations. The simulation results show the effectiveness of the proposed method against the external torque and mechanical parameters uncertainties.

The proposed FO-MRAS based on Lyapunov adaptation mechanism is proposed for the first time. Moreover, application of the FO-MRAS for velocity control of PMSM is presented for the first time.

The state of the different practices in construction industry determines its performance level. Hence, improving performance of construction industry needs assessing state of the practices in the industry and devising improvement intervention. The purpose of this paper is to measure improvement requirement level of different construction management practice areas and to identify the underlying improvement dimensions in Ethiopian construction industry.

Questionnaire survey was developed for data collection based on a thorough literature review which yielded 28 construction management practice areas. Purposive sampling method was used to select respondents for the survey. Mean score was used to identify the required improvement level, and one sample T-test was carried out to identify significance of improvement requirement. Factor analysis was conducted to identify the underlying dimensions of the construction management practice areas.

Findings indicate 27 areas need significant improvement. This shows the low level of adoption of good construction management practices in Ethiopian construction industry. Factor analysis resulted in the areas being grouped to four broad improvement dimensions, namely, project management, organization management, knowledge and risk management and project development and contract management.

The findings provide information for appropriate action by the stakeholders to raise standards of adopted construction management practices. It also show areas of construction management which require more focused research in the context of Ethiopian construction industry. Considering the similarity of nature of construction industry problems in developing countries, the findings can be extended to similar countries.

The blockchain technology is based on distributed ledger. Many stakeholders, such as developers, entrepreneurs and technology lovers, consider the blockchain as an economic and business re-creation that is faced with numerous challenges in its application. Blockchain technology is the backbone of many digital currencies, i.e. Bitcoin and Ethereum. Although presently digital currencies are recognized as payment and exchange instruments in many countries, the economic sanctions imposed on some countries have restricted the possibility of the trading. So, this study seeks to evaluate the adoption of blockchain for digital currency use in Iran in the shadow of economic sanctions.

The developed value-based technology adoption model and smart PLS software have been used in this research. The statistical population of the study was people active in the Iranian stock market; the purpose for this selection was their familiarity with financial and digital currency issues.

The results show that the terms of sanctions, usage and facilitating conditions are directly related to users' perceived value of digital currency and its use; As a result, in a sanctioned country like Iran, the use of digital currencies is being accepted as a way of rolling out economic sanctions and thus making commercial payments.

As well as the fact that evaluating the adoption of the blockchain technology in a sanctioned country like Iran is considered as the originality aspect of the research, applying an extended model in the technology adoption is also the research innovation.