Surapong Siripongdee

This research aims to study the factors influencing the sustainable performance of health food businesses in Thailand and to propose a sustainable performance model for these businesses. The sample group consisted of 260 health food business operators in Thailand. The research instrument was a questionnaire. Data were collected using a questionnaire and analyzed using partial least squares structural equation modeling (PLS-SEM). The findings revealed that innovation, service quality, and competitive advantage had direct effects on sustainability. In addition, innovation was found to have indirect effects on sustainability through service quality and competitive advantage as mediating variables. When innovation, service quality, and competitive advantage were jointly considered, the model explained 60.7% of the variance in sustainability (R² = 0.607). The results indicate that innovation serves as a fundamental driver that enhances service quality and competitive advantage, which subsequently contribute to sustainable performance. This research provides policy and practical implications for enhancing innovation and service quality, enabling businesses to achieve competitive advantage, respond effectively to the diversity of the food business sector, and promote continuous development toward sustainable future operations.

Sustainable rice cultivation requires field-based strategies that reduce environmental impacts while maintaining crop productivity. This study presents an exploratory field evaluation of activated carbon-based soil amendment formulations combined with greenhouse gas monitoring in jasmine rice cultivation in Nakhon Luang District, Phra Nakhon Si Ayutthaya Province, Thailand. Six treatment-level field plots were evaluated using Khao Dawk Mali 105 rice, including a no-amendment control, urea fertilizer 46-0-0, and activated carbon-based amendments containing 2%, 4%, 6%, and 8% activated carbon. Four 2 m × 2 m subplots within each treatment plot were used as within-plot sampling locations and were not treated as independent field replicates. Greenhouse gases were monitored using a closed chamber method coupled with a GASERA ONE gas analyzer, while heavy metals in soil and white rice grain were analyzed using atomic absorption spectrophotometry. The AC-based amendment 6% treatment showed the lowest observed CH₄ response, whereas the AC-based amendment 4% treatment showed the lowest observed N₂O response and lower Pb and Cr concentrations in white rice grain. The AC-based amendment 8% treatment produced the highest yield at 1,582.53 kg ha-1. These findings provide preliminary field evidence and require confirmation through fully replicated field trials.

Thailand's transition to a super-aged society requires innovative management frameworks to support technology-enabled healthcare for older adults. Smartwatches offer significant potential for continuous health monitoring. However, a validated management model suitable for Thailand's healthcare context remains underdeveloped. Therefore, this study developed and validated a second-order confirmatory factor analysis (CFA) of smartwatch innovation management factors for holistic older adult care, grounded in stakeholder perspectives. A cross-sectional survey was conducted with 260 stakeholders involved in a smartwatch-based elderly care pilot project in Thailand's northern Chiang Rai Province. Participants included physicians, nurses, village health volunteers, and caregivers. Data were collected using a five-point Likert-scale questionnaire comprising 13 observed variables across four proposed components. These included Health Data Management (HMS1), Holistic Health Integration (HMS2), Connection with Healthcare Services (HMS3), and Technology Design Suitability for Older Adults (HMS4). LISREL was used to conduct the CFA, which assessed construct validity. The second-order model demonstrated excellent fit (χ² = 2.54, df = 6, p = 0.952, χ²/df = 0.42, RMSEA = 0.00, CFI = 0.99, GFI = 0.98). All first- and second-order factor loadings were statistically significant (p < .01). HMS4 (β = 0.95) and HMS3 (β = 0.94) emerged as the most influential dimensions. Construct reliability and convergent validity were confirmed (CR ≥ 0.75; AVE ≥ 0.50). The findings indicate that effective smartwatch innovation management for older adults must prioritize age-appropriate technology design and integration with formal healthcare systems. The validated framework provides policy and implementation guidance grounded in professional stakeholder assessment.

This study investigates the factors influencing the return willingness (RW) of diners at Michelin-starred restaurants in Thailand. The focus is on understanding how service novelty (SN), new product innovation (NPI), culinary standards (CS), and diner satisfaction (DS) contribute to diners' intentions to return. A quantitative approach was employed using structural equation modeling (SEM) to analyze data collected from a sample of 320 diners. The study examined the direct and total effects of the variables on RW. The analysis revealed that service novelty, new product innovation, culinary standards, and diner satisfaction collectively account for 75% of the variance in return willingness (R² = 0.75). Service novelty, new product innovation, and culinary standards exhibit significant direct effects on return willingness, with total effect (TE) values of 0.87, 0.79, and 0.76, respectively. Diner satisfaction also significantly impacts return willingness, with a TE value of 0.42. All nine proposed hypotheses were supported, confirming the positive influence of SN, NPI, CS, and DS on diners' return willingness. The study underscores the critical role of continuous innovation, high culinary standards, and exceptional diner satisfaction in fostering repeat business. These factors are integral to enhancing customer loyalty at Michelin-starred restaurants in Thailand. The findings offer valuable insights for restaurant managers aiming to boost customer loyalty and sustain long-term success. Emphasizing service innovation, maintaining high culinary standards, and ensuring diner satisfaction can significantly improve diners' return willingness.

The COVID-19 pandemic has heightened the need for 21st century skills, particularly computer and ICT literacy (CICT) in Thailand. This study aimed to develop a TPACK (Technological Pedagogical and Content Knowledge)-based blended learning model (BLM) to enhance CICT skills and academic performance among 179 Business Administration (BA) undergraduates in the 2022 academic year Computer and Information Applications course. Research instruments were designed and evaluated by experts. Over 18 weeks, qualitative and quantitative data were collected, with the qualitative data undergoing content analysis. Descriptive statistics were used to analyze quantitative data, comparing pretests, post-tests, and 2-week retests using a repeated measure ANOVA. One-sample t-tests were used to assess the model’s impact on CICT skills. The results showed a significant score improvement between tests, with the highest mean being seen in the 2-week retest. The BA-TPACK model significantly enhanced CICT skills, exceeding 80%. The students expressed high satisfaction, with the BA-TPACK model effectively enhancing CICT skills and academic achievement, recommending its integration into future computer and information courses. This study’s contribution lies in addressing the pressing need for CICT skills in the ‘new normal’. By developing and implementing a BLM grounded in the TPACK framework, this study not only enhances students’ CICT proficiency but also fills a crucial gap in the literature regarding effective pedagogical approaches to foster 21st century skills.

MULTIPLE-INPUT SINGLE-OUTPUT VOLTAGE-MODE MULTIFUNCTION FILTER BASED ON VDDDAS

An alternative method for synthesising the sinusoidal oscillator based on series negative resistance-capacitance is presented in this paper. The proposed topology is constructed with the series negative resistance-capacitance circuit connected in parallel with a grounded resistor and capacitor. To validate the proposed method, a new grounded series negative resistance-capacitance simulator is also proposed as a subcircuit for synthesising the sinusoidal oscillator. The series negative resistance-capacitance simulator is based on a commercially available integrated circuit (IC), LT1228. The equivalent negative resistance and equivalent negative capacitance can be adjusted electronically using an external DC bias current. The sinusoidal oscillator that is synthesised using the proposed method consists of a single LT1228, two capacitors, and three resistors. The frequency and the condition of the oscillation are orthogonally adjusted. Also, the condition of oscillation is electronically controlled. The amplitude of the sinusoidal waveform is adjustable. In addition, the output voltage node of the proposed oscillator has a low impedance, which allows it to connect to other circuits without using an additional buffer. Both PSPICE simulation and experiment are used to validate the proposed circuits.

In this contribution, the design and analysis of an active multifunction biquad filter that provides five voltage-mode filtering configurations in the same core filtering circuit are presented. The design emphasizes using the commercially available ICs, LT1228, which are easy for off-the-shelf implementation and cheaper compared with the chip implementation. The proposed multifunction filter is realized from two commercial LT1228 ICs as the active function block, combined with five passive elements (three resistors and two capacitors) with three input voltage nodes and a single output voltage node. The following advantages are given for this design: (i) it provides high-pass (HP), low-pass (LP), band-stop (BS), band-pass (BP), and all-pass (AP) filtering functions; (ii) orthogonal and electronic tuning of the natural frequency and bandwidth (the quality factor: Q); (iii) output voltage node of the proposed circuit is low impedance; (iv) passband voltage gain is controllable; and (v) matching condition and extra double gain voltage-mode amplifier are not required. The effect of the parasitic element in LT1228 on the filter performance is analyzed and included to strengthen the design idea. The PSpice simulation results using LT1228 with ±5 V and the experimental results tested from the hardware implementation are given to prove the validity of the designed multifunction filter.

This paper presents the design of a voltage-mode three-input single-output multifunction first-order filter employing commercially available LT1228 IC for easy verification of the proposed circuit by laboratory measurements. The proposed filter is very simple, consisting of a single LT1228 as an active device with two resistors and one capacitor. The output voltage node is low impedance, resulting in an easy cascade-ability with other voltage-mode configurations. The proposed filter provides four filter responses: low-pass filter (LP), high-pass filter (HP), inverting all-pass filter (AP−), and non-inverting all-pass filter (AP+) in the same circuit configuration. The selection of output filter responses can be conducted without additional inverting or double gains, which is easy to be controlled by the digital method. The control of pole frequency and phase response can be conducted electronically through the bias current (I_B). The matching condition during tuning the phase response with constant voltage gain is not required. Moreover, the pass-band voltage gain of the LP and HP functions can be controlled by adjusting the value of resistors without affecting the pole frequency and phase response. Additionally, the phase responses of the AP filters can be selected as both lagging or leading phase responses. The parasitic effects on the filtering performances were also analyzed and studied. The performances of the proposed filter were simulated and experimented with a ±5 V voltage supply. For the AP+ experimental result, the leading phase response for 1 kHz to 1 MHz frequency changed from 180 to 0 degrees. For the AP− experimental result, the lagging phase response for 1 kHz to 1 MHz frequency changed from 0 to −180 degrees. The design of the quadrature oscillator based on the proposed first-order filter is also included as an application example.