Asian Institute of Technology

Onsite sanitation coverage has expanded significantly since 2020, driven by global commitments to eliminate open defecation and the need for adaptable solutions in rapidly urbanising small- and medium-sized cities (<1 million inhabitants) in Low- and Middle-Income Countries. Currently, 53% of individuals with access to a toilet depend on onsite sanitation systems. Despite this prevalence, the contribution of greenhouse gas emissions from household-level excreta storage to climate change remains poorly quantified due to limited empirical evidence. We addressed this gap by conducting direct measurements of methane emissions from 146 onsite sanitation containment units locally referred as pit latrines, holding tanks and septic tanks, across Senegal, Ethiopia, Uganda and Nepal. Methane emission rates exhibited strong skewness with a geometric mean of 7.9 g CH₄ capita⁻¹ day⁻¹, indicating that onsite sanitation containment units alone may account for approximately 3.8% of global anthropogenic CH₄ emissions.

Eutrophication is a pervasive issue in Mediterranean reservoirs, where external nutrient inputs and internal sediment releases interact to impair water quality and ecological stability. This study assessed the trophic condition of the artificial lake Cuga in Sardinia (Italy), mainly used for irrigation and providing potable water, by integrating watershed nutrient load estimates, inter-lake transfers, and internal phosphorus release. Field campaigns between July 2022 and May 2023 provided bi-monthly measurements of physical, chemical, and biological parameters, complemented by GIS-based land cover analysis and export coefficient modeling to quantify spatial nutrient sources. Additional phosphorus inputs from water transfers with a nearby reservoir were calculated, while internal sediment release was estimated using a calibrated mass balance model. Results revealed high nutrient concentrations, with mean total phosphorus of 128 mg P m−3, chlorophyll a averaging 9.9 mg m−3, and Secchi depth below 1 m, classifying the reservoir as eutrophic to hypertrophic under OECD and Carlson indices. Spatial loads were dominated by agricultural areas, while inter-lake transfers and internal sediment release contributed substantially to the overall phosphorus budget. The predictive Vollenweider model closely matched the observed conditions, confirming the robustness of the combined approach. Maintaining good ecological status in Mediterranean reservoirs is essential for safeguarding human well-being, as eutrophication degrades drinking-water quality, increases treatment costs, and can promote toxin-producing algal blooms with direct implications for public health. These findings highlight the need for integrated management strategies addressing both external and internal nutrient sources to mitigate eutrophication in Mediterranean reservoirs, which affects the ecosystem functioning and the related human needs and well-being.

Tuberculosis (TB) incidence remains uneven across ASEAN economies and China, reflecting differences in health-system capacity and broader development conditions. This study examines whether routine immunization performance—treated as a measurable proxy for primary healthcare delivery capacity—is associated with TB incidence over time. Using a balanced country–year panel covering 11 economies from 2000 to 2022 (N = 253), the analysis constructs an Immunization Index as the mean of DPT and measles immunization coverage. The outcome is TB incidence per 100,000 population, estimated in both level and logarithmic forms. The empirical strategy combines descriptive association tests with multivariable panel regressions, including two-way fixed effects (country and year) to account for time-invariant national characteristics and common temporal shocks. In pooled and fixed-effects level models, immunization is negative but not statistically significant. In a two-way fixed-effects log specification, immunization is marginally significant (β = −0.0034, p < .10). The preferred lagged log fixed-effects model indicates a statistically significant delayed association: a one-point increase in the prior-year immunization index is associated with approximately a 0.54% reduction in current-year TB incidence (β = −0.0054, p < .01), implying roughly a 5.26% reduction for a 10-point improvement. Electricity access and internet use are consistently negative and significant in log fixed-effects models, highlighting the role of enabling infrastructure and connectivity. Findings support an interpretation of immunization performance as a system-capacity indicator linked to subsequent reductions in communicable disease burden, while recognizing the observational design and limited number of country clusters.

This study employs a Vissim–Matlab component object model (COM)-based microsimulation model to evaluate the effectiveness of variable speed limit (VSL) strategies during traffic incidents. This study examines two VSL strategies on a 2.7 km section of Thailand’s Motorway No. 7: VSL1 with 1 km spacing and VSL2 with 2 km spacing. Simulation results show that under peak volume conditions, the VSL1 strategy outperforms both the existing scenario and VSL2 in terms of traffic performance and safety. This advantage holds for single-lane closures for both short and long periods. However, for two-lane closures with prolonged incident-clearance times, the VSL system should be temporarily deactivated to prevent increased congestion. Sensitivity analysis results indicate that under mild to moderate traffic volumes, VSL1 and VSL2 perform similarly in both traffic performance and safety across single- and double-lane closures and both closure durations. Both strategies outperform the existing scenario in nearly all cases. The VSL implementation yielded up to an 18% increase in average speed and an 88% reduction in rear-end conflicts. The magnitude of these improvements increased as traffic demand decreased. However, under congested conditions with two-lane closures, the VSL system should remain inactive regardless of the expected incident-clearance time.

ABSTRACT Machine learning in water quality prediction has been a major interest and has achieved satisfactory results in previous research. But there is still a gap in doing the research on the data scarcity environment. The Chao Phraya River is the major river of Thailand, and the PCD has monitored the major rivers' water quality four times per year. There are 19 water quality monitoring stations along the river, including six stations at the lower part of the river. This study investigates two machine learning models' performances on predicting non-optically active water quality parameters, NO3-N and TP, at the lower part of the river by using remote sensing data and ground measurement data. The result indicates that XGBoost outperformed Random Forest in predicting the target variable: NO3-N (R2 = 0.75) and TP (R2 = 0.61) using an 80/20 train-test split. Despite the limited sample size, the models were able to extract meaningful patterns, though performance remained variable across cross-validation folds. These findings highlight the potential of machine learning for water quality prediction in data-scarce environments while emphasizing that more data are required to improve model robustness. This study provides a transferable workflow and contributes an initial step toward water quality prediction in data-limited conditions.

Legacy book and stationery retail remains structurally important in the Philippines because it supports access to learning materials, school supplies, and low-friction educational consumption across socio-economic segments. National Book Store, Inc. (NBS)—a long-established market leader—now operates in a rapidly shifting environment marked by accelerating e-commerce penetration, digital content substitution, platform-based price competition, and heightened consumer expectations for convenience and assortment transparency. This study examines NBS’s strategic positioning and adaptive direction under digital disruption, with particular emphasis on its emerging omnichannel transition. A qualitative case study design is employed using secondary data drawn from government and industry reports, market analyses, academic sources, and credible public-facing materials. The analysis applies a structured strategic-analytics sequence combining PESTEL macroenvironment scanning, market and competitive assessment, and SWOT synthesis to surface capability strengths, structural constraints, and actionable opportunity spaces. Findings indicate that NBS’s enduring advantages—brand salience, nationwide retail access, and a diversified learning-and-lifestyle assortment—continue to anchor its relevance. However, exposure to platform competition, operational frictions in product discovery and inventory experience, and category-level shifts toward digital consumption create vulnerabilities that require deliberate capability upgrading. The findings suggest that NBS’s sustainability will depend on strengthening its digital customer experience, tightening omnichannel integration, and building partnership ecosystems with schools, publishers, and content providers to preserve trust and differentiation in a platform-dominated retail landscape.

This study tests whether women’s empowerment is associated with formal enterprise dynamism in the Philippines using annual World Development Indicators (WDI) data from 2006–2022 (N = 17). Enterprise dynamism is measured by new business density (new limited-liability firm registrations per 1,000 working-age people). Women’s empowerment is operationalized as a composite Women’s Empowerment Index (WEI) built from seven WDI indicators capturing women’s economic participation and job quality, autonomy-related constraints, and institutional inclusion (constraint indicators reverse-coded). Using OLS time-series regression with HAC/Newey–West standard errors, WEI is positively associated with new business density in baseline models (β = 0.061, p < .01) and remains positive after conditioning on log GDP per capita and trade openness (β = 0.159, p < .01). Controlling for pandemic disruption yields a large negative 2020 shock (β = −0.089, p < .01) while the WEI association remains positive (β = 0.132, p < .05). Measurement robustness using a PCA-based WEI preserves a positive coefficient (β = 0.123, p < .10), whereas a one-year lag specification provides no evidence of delayed effects (β = 0.002, p = .962; N = 16). Overall, empowerment conditions co-move positively with formal firm entry in the Philippines, while causal interpretation remains limited by the single-country observational design.

Investment participation in the Philippines remains limited, and decisions to invest are shaped not only by financial capacity but also by evaluative beliefs, risk appraisal, institutional trust, and perceived readiness to engage with capital markets. Guided by an extended Theory of Planned Behavior, this study examined correlates and predictors of investment decision among 483 respondents from Calamba City, Santa Rosa City, and Biñan City, Laguna. A descriptive, cross-sectional design was implemented using an online questionnaire that measured risk tolerance, attitude toward capital markets, knowledge on capital markets (financial literacy), government trust/political climate, attitude toward investment, and self-reported investment decision using a six-point scale. Descriptive results indicated relatively high ratings for risk tolerance (M = 4.81, SD = 1.19) and attitude toward capital markets (M = 4.60, SD = 1.23), moderate capital market knowledge (M = 4.10, SD = 1.32), and comparatively lower government trust (M = 3.85, SD = 1.33). Investment decision differed significantly by sex (p = .002) and by monthly salary bracket (p < .001). Investment decision also showed positive associations with capital market knowledge (r = .210, p = .001) and attitude toward investment (r = .179, p = .003). Stepwise regression identified attitude toward investment (coefficient = 0.345) and monthly salary (coefficient = 0.368) as significant predictors, explaining 16.2% of the variance (R² = 0.162, p < .001). The findings suggest that investment-readiness initiatives should integrate capability-building in capital market knowledge with attitude-focused interventions, while addressing socioeconomic constraints that shape the feasibility of investing.