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This study aims to examine the influence of ownership structure and board composition on the probability and intensity of stock repurchases. The study’s sample comprises 3,744 firm-year observations, consisting of 53 repurchasing firms with 96 firm-year observations from 2008 to 2019.

Probit and fixed-effects regression models are used to obtain empirical results. Moreover, a probit model with a continuous endogenous regressor (IV-probit) and an instrumental variable method with two-stage least squares (IV-2SLS) estimation are used to address endogeneity.

Corporations with high family or state ownership tend to inhibit stock repurchases to hoard excess free cash flow, supporting agency theory. Conversely, firms with high board independence tend to repurchase their stocks at least once to distribute free cash flows to shareholders, confirming agency theory. Nonetheless, corporations with more female directors on the board or CEO duality tend to conduct stock repurchases at least once but do not repurchase stocks with high values. Interestingly, more female directors on the board may send false signals about undervalued stocks.

This is the first study to reveal that firms with CEO duality repurchase their stocks at least once but avoid repurchasing shares with high values. It is also the first study to explore whether women on a board may cause false signaling about undervalued stocks. Furthermore, this study reveals that family and state ownership are potential determinants of stock repurchases in countries with high ownership concentration. This is the first study to address this issue in Thailand.

The purpose of this study is to provide the enhancement of power quality of a high power-rated voltage source inverter driven induction motor with a three-phase, three-level neutral point clamped converter placed at the front end, while a passive power filter is connected in shunt with it. The improvement in power quality can be achieved by reducing the total harmonic distortion in source current. The controllers were designed for the linearization of the high-power induction motor drive. A control method is presented for the regulation of the common DC-link voltage.

The induction motor is modeled using its dynamic equations, and a decoupling controller is designed to linearize the nonlinear dynamics of the drive through feedback. The common DC-link voltage of the proposed front-end connected converter is monitored and controlled through a control method which feeds the pulse width modulated inverter that drives the induction motor. A passive power filter is designed to meet the reactive power requirement of the system in addition to improve the power quality.

Simulations were carried out for the proposed topology of the drive mechanism, and the outcomes were analyzed by a comparative analysis of the drive system both in the presence of the passive filter as well as in the absence of the filter. The total harmonic distortion is found to be reduced enough to meet the standards with the designed filter, and the reactive power is also compensated considerably. The input power factor at the supply side is maintained almost to unity, and the DC-link voltage of the proposed circuit topology is maintained at the desired level. The overall performance of the drive system was found to be useful and economical.

A new topology of a front-end connected three-level neutral point clamped converter to a high power-rated induction motor drive is proposed. The drive is fed by a pulse width modulated inverter with a common DC-link with the front end connected converter. A passive filter is designed with respect to the reactive power requirement of the system and connected in shunt to the converter at the supply side. Control schemes are designed and used for the drive system and also for the regulation of the common DC-link voltage of the proposed front end connected converter.

The purpose of this study was to improve the overall equipment effectiveness (OEE) of the production process of the shredder operation of ABC company, an industrial waste management company which supplies pre-processed industrial waste as alternative fuel to a cement plant.

This case study investigated all possible availability and performance losses that caused the shredder system’s OEE and various problem-solving techniques, such as root cause analysis and Pareto analysis, were used to find the root cause of the reduced OEE.

After analysing this case study, three significant loss factors were identified from all the availability and performance losses, which caused the shredder system’s OEE losses. Practical solutions were found for the effect of those loss factors to improve the machine’s OEE and productivity.

This case study has been concentrated on only analysing of losses and improvement of OEE in the production process and not about cost analysis between loss and improvements.

This paper shows how to improve the OEE of a production process through various problem-solving techniques by identifying its losses and how to achieve the best solutions for those losses in a practical manner.