Siam University (SU, Thai: มหาวิทยาลัยสยาม) is a university located on Phet Kasem Road in Phasi Charoen District, Bangkok. Siam University was founded by the late Narong Mongkhonvanit as a three-year private engineering school in 1965.In 1973, Siam University, then known as Siam Technical College, was formally established as a higher education institution with authorization to grant degrees. Later in 1986, Siam Technical College became Siam Technical University, a full-fledged private, non-profit university. Three years later, the name was changed again to Siam University to reflect the diversity in the fields of study offered.In 1995, the international college was established. Currently, over 400 international students from more than 15 countries are enrolled in the international college of Siam University.The governing body of Siam University is the university council led by Kasem Wattanachai, councilor of the Privy Council of Thailand.
PurposeThe implementation and test of electronic circuit able to operate with significant negative delay remain an open challenge for design engineers. This study aims to design an innovative multistage low-pass (LP) type negative group delay (NGD) active circuit. The considered LP-NGD topology is constituted by RC-network. After the proof-of-concept (POC) design and simulation, a printed circuit board (PCB) of LP-NGD active topology prototype was fabricated. The LP-NGD PCB was tested to confirm the possibility to propagate arbitrary waveform signal. The time-advance measurement result enables to verify the simulation one.Design/methodology/approachAfter the NGD value, bandwidth choice and number of cells, this innovative design method of multi-stage LP-NGD circuit is established under the following phases: the first phase is the calculation of resistors and capacitors constituting the considered topology. The second phase is the schematic simulation of the LP-NGD POC in the frequency domain. In the third phase, the obtained LP-NGD POC must be optimized. In the fourth phase, the available R, C and operational amplifier are chosen the PCB prototype. In the last phase, the test signal must be chosen to demonstrate the output in time-advance.FindingsAn innovative design theory, including the analytical and algorithm, to determine the multistage RC-circuit parameters is established in function of targeted LP-NGD specifications. The validity of the multistage RC-circuit design theory is verified by the PCB prototype experimentation showing measurement of -0.3 s signal advance.Originality/valueThis research work originality is the analytical and routine algorithm design methodology of multistage LP-NGD electronic circuit. The transient result obtained by considering arbitrary waveform signal tested with a PCB prototype confirm the relevance of the developed multistage LP-NGD RC-circuit design.
This paper studies second α -order dynamical systems within the framework of fractal calculus and examines their behavior under fractal proportional–derivative (FPD) and fractal proportional–integral–derivative (FPID) controllers. A brief overview of fractal calculus is provided, and fractal initial value and final value theorems are formulated. The structure of FPID control for second α -order systems is presented, and the stability conditions are analyzed within the fractal setting. The response of FPD controllers is also investigated through analytical expressions and numerical simulations for selected values of the fractal order α . As an illustrative example, a series RLC circuit is modeled using fractal derivatives to demonstrate how fractal-order dynamics influence the controlled system response. The results emphasize the role of the fractal order α in shaping transient behavior and steady-state characteristics.
This research introduces a novel approach by applying the effective nonlocal parameter (ENP) through the third-order shear deformation theory (TSDT) for investigating the free vibration of a functionally graded material sandwich (FGM-SW) nanoplate embedded in a Kerr elastic foundation under heat conduction, solved numerically using Navier's closed-form solution. In this study, an analytical model incorporates temperature-dependent (TD) material properties and nonlinear temperature distribution (NTD), which are formulated using the temperature functions and polynomial power series, respectively. The governing equations are derived using Hamilton's principle for the FGM-SW nanoplate. The impact of different ENP, power-law index, temperature rise, elastic foundation, and the nonlocal parameter ratio on both low- and high-order frequency parameters is demonstrated. The results reveal that variations in the ENP significantly influence the frequency of the FGM-SW nanoplate model, with a more pronounced impact observed for ceramic-based ENP than for metal-based ENP. This distinction arises from the composition of the FGM-SW nanoplate, which comprises FGM skins and a ceramic core. Notably, the trends vary when the constant nonlocal parameter (CNP) is assumed for ceramic versus metal.
This study investigates how generative artificial intelligence (AI) facilitates ethical and sustainable travel behaviour in AI-enabled smart urban tourism destinations within the context of urban tourism and smart tourism cities. The study highlights how AI reshapes tourist experiences, decision-making, and ethical engagement in complex, high-density urban environments where digital infrastructures are deeply embedded. The analysis employed an Integrated Generalised Structured Component Analysis to examine structural relationships, which was complemented by a Necessary Condition Analysis in order to identify indispensable prerequisites for behavioural transformation. The results show that perceived AI transparency strongly predicts digital reflexivity, which in turn influences AI-induced place reinterpretation and AI-enabled experience co-creation. Co-creation exerts a stronger effect on ethical travel citizenship than place reinterpretation does, whereas ethical citizenship strongly predicts post-travel AI engagement. The necessary condition analysis results confirm that all constructs function as necessary conditions along the cognitive - affective-behavioural sequence. This study contributes to urban tourism research by offering a novel theoretical integration of the cognitive - affective-behavioural model, the transformative learning theory to explain how AI-mediated interactions in smart tourism cities can transform tourists' ethical orientations and long-term engagement. It also offers practical guidance for tourism practitioners, AI developers, and policymakers in regards to designing transparent and value-sensitive AI tools that promote lasting sustainable travel engagement.
Background Improper storage and disposal of unused and expired medicines at home have become a global challenge, creating significant hazards to public health and the environment. This systematic review aimed to explore the prevalence of proper storage and disposal of medicines and to examine factors influencing these proper behaviours.Method We searched PubMed, Scopus, Springer Link, Science Direct, and EBSCO for articles published between 1 January 1990, and 31 May 2023. Inclusion criteria included studies conducted about medicines in a household setting, articles written in the English language, and full text that could be retrieved. Exclusion criteria included pilot studies, editorials, or opinions. The QualSyst assessment tool was applied to evaluate the quality of the included studies. This systematic review was conducted and reported in accordance with the PRISMA 2020 (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. The prevalence of proper storage and disposal, determinants of proper and improper storage, and proper disposal of medicines were elaborated using both quantitative and qualitative methods.Results The search found 822 articles and included 61 eligible studies from 27 countries. The overall prevalence of proper medicine storage was only 45%. The proper disposal rates were only 13% for unused medicines and 8% for expired medicines. Proper storage was positively associated with knowledge, education, storage counselling, presence of chronic illness, household size, and the number of children in the household; and negatively associated with age and male gender. Proper disposal was positively associated with awareness, peer influence, knowledge, education, and having family members who are incapable of independently managing their medicine.Conclusion Proper storage guidance should be included on a medicine label for every medicine dispensed by pharmacists. The take-back programmes campaign and public education related to proper disposal of medicine were recommended to save the environment and public health.
