Key Constraints Research Articles

Beyond geopolitics: Agency and modularity in mobile telecommunications in Kazakhstan

Much of the discourse on U.S.-China tech decoupling has centered on trade and geopolitics, often overlooking the ground-level realities of developing countries and their strategic digital choices. The telecommunication industry, with its international supply chain and long-term orientation, is a particularly interesting locus to explore distributed and ground-up agency in countries that depend on Western and Chinese tech giants. In this article, we draw on fieldwork in Kazakhstan conducted in 2022 and 2023, primary and secondary sources, to describe the decision-making process in building and maintaining mobile telecom infrastructure. We identify three key constraints shaping this process - market and network structures, distribution and procurement process, and (geo)political and security considerations. Within these constraints, we uncover spaces for agency at different levels and highlight the ability of different actors – from engineers to telecom companies' management - to influence choices in hardware, software and financing. We argue that the strategic role of telecom firms in national economies, the industry's long-term orientation and modularity, and the firms' ownership structures serve as important counterbalances to sudden disruptions caused by international politics. In a digital world increasingly shaped by competition between U.S. and Chinese tech giants, findings from Kazakhstan highlight the potential for developing countries to carve their own digital trajectories and offer a framework for future research to extend this analysis to other sectors and regions.

Study on Optimizing Inventory to Minimize Waste in the Fresh Produce Supply Chain

Abstract: The increasing demand for fresh produce, particularly greens, presents unique challenges in inventory management due to their short shelf life and susceptibility to spoilage. Inefficient management often results in significant waste, leading to financial losses for retailers and increased environmental burdens from the disposal of spoiled goods. Despite various strategies being employed in the agri-food sector, gaps remain in understanding how to optimize inventory levels to minimize waste at the retails level while maintaining high service levels for customers. This research aims to develop an inventory management model tailored to fresh produce that can mitigate these issues by balancing stock availability and minimizing wastage, particularly in large retail shops. To address the research problem, a mixed-integer linear programming (MILP) model was developed, focusing on three service levels—90%, 92%, and 95%—to evaluate the trade-offs between customer satisfaction and total inventory costs. The model incorporates key constraints, including stock balance, shelf-life limitations, and demand satisfaction. The model was validated using actual data, including stock, sales, and wastage records for the month of August, 2024. The objective function aimed to minimize total costs, encompassing holding costs, wastage, and lost revenue. The findings indicate that higher service levels, while reducing stockouts, significantly increase costs due to excess inventory and waste. The most cost-effective solution was observed at the 90% service level, which balanced waste reduction and customer satisfaction. The study also emphasizes the importance of integrating total cost reduction and minimize wastage. Future work should focus on incorporating consumer behavior patterns and extending the model to multi-echelon inventory systems, which include both distribution centers and retail outlets, to capture a more holistic view of the supply chain.

Perception and Attitude of Consumer Patronage of Ghana-Grown Rice: Evidence from Kumasi, Ghana

Increasing human population, urbanization, and changing consumer trends have contributed to the emergence of rice as the leading staple food in Ghana. Despite its importance in the Ghanaian diet, patronage and consumption of locally grown rice are not yet widespread. This study investigates consumer patronage of locally grown rice in the Kumasi Metropolis, Ghana, and fills a critical gap in understanding the specific factors that influence consumer preferences in urban settings. Data were collected through a cross-sectional survey of 120 respondents across different income categories using a multistage sampling technique and analyzed using descriptive statistics, a Probit model, and Kendall's coefficient of concordance. The study found that cooking quality, palatability, colour, and fragrance were the primary attributes that influenced consumer preferences. Probit analysis revealed that income and the frequency of rice consumption significantly influenced the likelihood of purchasing locally grown rice. Specifically, a higher income decreases, while frequent rice consumption increases the likelihood of choosing local rice. Key constraints identified include perceived high cost, limited availability, and concerns about the quality of rice. This study recommends that local rice producers, agricultural organizations, and government bodies should make efforts to improve the sensory and culinary qualities of locally grown rice through improved processing techniques, increased promotion, and campaigns to ensure the commodity is readily available to consumers. These strategies aim to boost local rice consumption and support agricultural sustainability and food security in Ghana.

Rapid remote volcanic ashfall impact assessment for the 2022 eruption of Hunga volcano, Tonga: a bespoke approach and lessons identified

When disasters occur, rapid impact assessments are required to prioritise response actions, support in-country efforts and inform the mobilisation of aid. The 15 January 2022 eruption of Hunga volcano, Tonga, and the resulting atmospheric shockwave, ashfall, underwater mass disturbance and tsunami, caused substantial impacts across the Kingdom of Tonga. Volcanic impacts on the scale observed after the eruption are rare, necessitating a reliance on international advice and assistance. The situation was complicated by the loss of Tonga’s international submarine fibreoptic cable (causing a complete loss of communications for approximately 20 days) along with border closures due to the COVID-19 pandemic. A need emerged for a rapid remote volcanic impact assessment and provision of specialist advice to help inform the response of international partners. Here we present a novel methodology for conducting rapid remote volcanic ashfall impact assessments, conducted over a 10-day period following the eruption. We used three different hazard models for ashfall thickness across the main island of Tongatapu and available asset information and vulnerability functions for buildings, agriculture, electricity networks, water supply and roads, to provide initial estimates of losses due to ashfall from the 15 January eruption. For buildings, we estimated losses both as total losses and as percentages of the total replacement cost of buildings on Tongatapu. For agriculture, we made probabilistic estimates of production losses for three different crop classes. For ashfall clean-up, we estimated ranges of ashfall volumes requiring clean-up from road surfaces and roofs. For water supply, electricity networks and roads, our analysis was limited to assessing the exposure of important assets to ashfall, as we had insufficient information on system configurations to take the analysis further. Key constraints on our analysis were the limited nature of critical infrastructure asset inventories and the lack of volcanic vulnerability models for tropical regions including Pacific Island nations. Key steps towards iteratively improving rapid remote impact assessments will include developing vulnerability functions for tropical environments as well as ground-truthing estimated losses from remote approaches against in-person impact assessment campaigns.

Cannabis Licensing and Municipal Revenues

Municipal license policy has shaped the early roll-out and business outcomes of Proposition 64. Several stakeholders identify license availability as a key constraint to future cannabis market growth in California. Recent studies explore local cannabis licensing policy; however, key questions remain around municipal revenues, business location, and the role of supporting cannabis business ownership. Our paper explores the impacts of cannabis licensing on business locations and municipal taxable revenues. We use publicly-available Department of Cannabis Control licensing data to examine business locations using GIS analysis, conduct a regression analysis of city-level licenses and Department of Tax and Fee Administration revenues across California, and forecast potential municipal taxable revenues in South Bay Los Angeles. We find that licensed cannabis businesses appear to develop in Los Angeles County and are located close to borders of cities not issuing licenses, in areas of favorable zoning, in densely populated locations, and areas with higher poverty and minority populations. Our regression analysis suggests that city population drives municipal taxable revenue, indicating that business follows demand.

From Field to Market: The Challenges Faced by Onion Growers in Chitradurga, Karnataka, India

Horticultural crops are integral to the Indian economy, serving as a major source of employment, and supplying vital raw materials to the food processing sector. Their cultivation leads to enhanced farm profitability, driven by increased yields and improved market opportunities. Moreover, the export of horticultural produce significantly contributes to foreign exchange earnings, further strengthening India's economic framework. Onion grows extensively across the nation in a variety of climates. India is the world's second-largest producer of onions. It ranks first in terms of acreage, third in terms of exports, and contributes roughly 22.83% to global production. The present study was conducted in 2023 in the Chitradurga district of Karnataka, aimed to identify the challenges faced by onion growers and gather their recommendations for addressing these issues. A total of 120 farmers were selected for the study, comprising sixty small and sixty big farmers. Utilizing an ex post facto research design, data were collected through a pre-tested, structured interview method. The findings highlighted several key constraints in onion cultivation, including limited awareness of nutrient management, price fluctuations in the market, and inadequate access to credit. The majority of farmers recommended the implementation of a minimum support price for onions and timely provision of credit at low-interest rate to mitigate these challenges.

Analysis of the Spatial Constraints of Urban Underpass Channels Based on BIM

The construction of urban underpasses faces various spatial constraints, which will lead to deformation or failure of the structures if not satisfied. The introduction of BIM (Building Information Modeling) and other modern information technology to achieve rapid and accurate spatial constraint analysis of the design scheme is of great significance to ensure the quality and safety of the underpass and adjacent structures. Firstly, through extensive literature collection and survey, the key spatial constraint indicators of underpasses in dense urban spaces and the evaluation rules of each indicator are determined. Then, an SQL (Structured Query Language)-based database of spatial constraint rules for underpasses in dense urban space areas is constructed, and the spatial constraint analysis process for underpasses in dense urban space areas is proposed. Finally, based on Building Information Modeling, programming support, and a development environment provided by C# and Visual Studio, a spatial constraint analysis system for underpasses in dense urban space areas is developed to realize complex spatial constraint analysis functions. The application practice of the system is carried out by taking a city underpass project as an example. The results show that in the design of urban underpass engineering, the spatial constraint analysis system designed in this paper and the calculation method adopted can simplify the model transmission process, save on labor costs, and reduce the error of the calculation results.

Assessing Key Constraints in Cashew Production: Insights from Kerala and Tamil Nadu, India

India ranks among the world’s top cashew producers, with Kerala and Tamil Nadu serving as key contributors to the country's cashew production. Among the Plantation sector, specifically cashew cultivation plays a pivotal role in boosting farm economy in India. This particular study explores field constraints experienced by cashew growers in Kerala and Tamil Nadu, which significantly impacts cashew cultivation. The key objective is to compare field challenges experienced by cashew growers among major producers in southern regions of India. The methodology involves a purposive multi-stage sampling approach to select regions, with an equal proportion of 80 respondents from each state selected through simple random sampling. Totally, 160 cashew growers were investigated for data collection through pre-tested structured interview schedule. The data sets were analysed using SPSS software, with frequency and percentage analysis employed to rank the identified constraints. The significant findings were pest and disease infestations, labour scarcity, unstable market price, lack of technical know-how and inadequate processing facilities. Notably, 100 per cent of growers reported that, Cashew Stem and Root Borer (CSRB) infestation as a most critical issue in both states. This paper highlights, region-specific and timely technical interventions, commodity-specific assured markets, proper pricing system and infrastructure development. The study's interpretation highlights the need to address high-priority and specialized constraints through targeted policy reforms and technical support systems, aiming to enhance the productivity and sustainability of cashew farming in India. These findings also provide valuable insights that can be applied to other cashew-producing regions and contribute to shaping national agricultural policies.

Telemedicine and time management in primary care.

Information and communication technologies (ICTs) can enable workers to structure work in novel ways, allow for better time management, and increase work scheduling autonomy. Time management and work scheduling are important factors in the field of clinical practice in primary care. Time limits on consultation are a key constraint on the delivery of good care since the length of patient-physician consultation impacts its quality. This research aimed to examine the experiences of primary care physicians (PCPs) when using telemedicine technologies (TTs), a type of ICT, in their communication with patients. During 2023 in-depth interviews were conducted with 20 Israeli PCPs: family physicians and pediatricians. Perception and management of time emerged as a focal subject in the interviews. The PCPs interviewed described several effects of TTs on time management in primary care. They portrayed TTs as saving time for patients and having a mixed effect on the healthcare organization: both saving and wasting their work time. TTs were described as impacting their time management in the context of work-life balance, allowing them to manage their time during and between appointments. For PCPs, TTs can be beneficial for managing time in the clinic, which can contribute to better healthcare. This article, concerning TTs as a type of ICT, contributes to the existing literature which suggests that ICTs can allow for better time management and increase work scheduling autonomy. It also presents several recommendations for better implementation of TTs in healthcare organizations.

Understanding Crop Diversification Among Smallholder Farmers: Socioeconomic Insights from Central Malawi

In Eastern and Southern Africa (ESA), smallholder rain-fed systems are vital, yet they are challenged by land degradation, soil fertility decline, and climate risks. To address these challenges, crop diversification has been promoted as a potential pathway to enhance productivity, improve nutritional security, and offer a viable pathway out of poverty and hunger. This study explores crop diversification among 150 smallholder households in the Kasungu, Mchinji, and Lilongwe districts of Malawi, where the project Sustainable Intensification of Maize Legume Systems in East and Southern Africa (SIMLESA) has engaged the smallholder farmers in conservation agriculture (CA)-based sustainable intensification participatory research and development for seven years since 2010. This study used Simpson’s diversity index (SDI) to estimate crop diversification, and a multiple linear regression model (MLRM) to analyze how smallholder farmers’ socio-economic characteristics influence adoption. The findings show a prevalence of small farms of less than 1.5 hectares, with most farmers perceiving crop diversification as beneficial for soil fertility. Key adoption constraints include labor shortages and a lack of legume seeds. SIMLESA participants lead in crop rotations, with a 63% higher adoption rate, and show the highest crop diversity, with a 99% increase in farmers growing three crops and a 74% increase in those growing four crops compared to non-SIMLESA farmers. The SDI values were 0.39 for non-SIMLESA, 0.48 for SIMLESA neighbors, and 0.57 for SIMLESA participants. Access to NGO inputs, larger farm sizes, and participation in research programs were positively associated with diversification, while food insufficiency was negatively associated with its adoption. The study highlights the importance of integrating participatory research methods to promote development initiatives effectively.

The effective elastic thickness along the Emperor Seamount Chain and its tectonic implications

Summary The Hawaiian-Emperor Seamount Chain, a pre-eminent example of a hotspot-generated intraplate seamount chain, provides key constraints not only on the kinematics of plates but also on their rigidity. Previous studies have shown that the effective elastic thickness, Te, a proxy for the long-term strength of the lithosphere, changes abruptly at the Hawaiian-Emperor ‘bend’ from low values (∼16 km) at the Emperor Seamounts to high values (∼27 km) at the Hawaiian Ridge. To better constrain Te along the poorly explored Emperor Seamounts we have used a free-air gravity anomaly and bathymetry gridded data set, together with fully 3-dimensional elastic plate (flexure) models, to estimate the continuity of Te and volcano load and infill densities along 1000 profiles spaced 2 km apart of the chain. Results show that Te generally decreases northward along the chain. The decrease is most systematic between Ojin and Jimmu guyots where Te depends on the age of the lithosphere at the time of volcano loading and is controlled by the 340°C and 400°C oceanic isotherms. The largest variation from these isotherms occurs at the northern and southern ends of the chain where Te is smaller than expected suggesting the influence of pre-existing, older, loads. We use these results to constrain the subsidence, flexural tilt, rheological properties, and tectonic setting along the seamount chain. We found an excess subsidence in the range 1.2-2.4 km, a tilt as large as 2-3°, oceanic lithosphere that is weaker than it is seaward of the weak zone at subduction zones, and a tectonic setting at Detroit and Koko seamounts that, despite their forming an integral part of the hotspot generated seamount chain, retains a memory of their proximity to earlier loads associated with plume influenced mid-oceanic ridges.

Enhancing Agro Morphological Traits of three Unique Traditional Rice Landraces of Chhattisgarh through Gamma Ray-Irradiation

Mutation breeding is a simple and effective technique for generating genetic variation within crops. Mutagens such as Gamma radiation induce changes in their DNA that could lead to the development of new traits, such as improved yield or disease resistance. In the present study, Gamma ray mutagenesis was performed on three traditional rice varieties (Gudma dhan, Dawar dhan, and Lohandi dhan) to identify potentially beneficial mutants with desirable agro-morphological agricultural characteristics. The major constraints to address were their tall statures and weak culms, fewer panicles and tillers, and late maturity. Using a fixed dose of 300 Gy, 35 mutants were identified in Dawar dhan, 33 in Gudma dhan, and 21 in Lohandi dhan. The selected mutants showed an average reduction in plant height that ranged from 42.69% to 33.11%, as compared to their respective landraces. Also, a substantial reduction (ranging from 3.08%-10.55%) in days to 50% flowering was observed. Importantly, these mutants showed an increase in yield of 38.11% (Dawar dhan), 32.63% (Gudma dhan), and 7.0% (Lohandi dhan). These findings demonstrate the utility of mutation breeding through Gamma radiation in alleviating the key constraints inherent to traditional rice landraces.

Research on the prediction method for fluvial-phase sandbody connectivity based on big data analysis--a case study of Bohai a oilfield

The connectivity of sandbodies is a key constraint to the exploration effectiveness of Bohai A Oilfield. Conventional connectivity studies often use methods such as seismic attribute fusion, while the development of contiguous composite sandbodies in this area makes it challenging to characterize connectivity changes with conventional seismic attributes. Aiming at the above problem in the Bohai A Oilfield, this study proposes a big data analysis method based on the Deep Forest algorithm to predict the sandbody connectivity. Firstly, by compiling the abundant exploration and development sandbodies data in the study area, typical sandbodies with reliable connectivity were selected. Then, sensitive seismic attribute were extracted to obtain training samples. Finally, based on the Deep Forest algorithm, mapping model between attribute combinations and sandbody connectivity was established through machine learning. This method achieves the first quantitative determination of the connectivity for continuous composite sandbodies in the Bohai Oilfield. Compared with conventional connectivity discrimination methods such as high-resolution processing and seismic attribute analysis, this method can combine the sandbody characteristics of the study area in the process of machine learning, and jointly judge connectivity by combining multiple seismic attributes. The study results show that this method has high accuracy and timeliness in predicting connectivity for continuous composite sandbodies. Applied to the Bohai A Oilfield, it successfully identified multiple sandbody connectivity relationships and provided strong support for the subsequent exploration potential assessment and well placement optimization. This method also provides a new idea and method for studying sandbody connectivity under similar complex geological conditions.

Study on the complex relationship of tourism-economy-ecological environment in arid zones: the case of Xinjiang, China

The synergistic integration of tourism, the economy, and the ecological environment within a region is crucial for promoting its sustainable development. Tourism acts as a catalyst for green economic growth, yet varying levels of tourism development can intensify the strain on the ecological environment. Thus, achieving a Pareto optimal balance among the benefits of these three entities holds significant theoretical and practical relevance. This research utilizes statistical data spanning from 2000 to 2021 to devise a tourism-economy-ecological environment (TEE) indicator system for Xinjiang. The study employs a coupled coordination model to analyze the spatial and temporal coupling dynamics between subsystems and to classify the types of coupled coordination. The analysis also identifies obstacles that impede the degree of coordination. The findings indicate that during the period under investigation, the TEE system in Xinjiang experienced consistent growth. However, the tourism subsystem exhibited disparate development and pronounced resource monopolization, which stimulated the economic subsystem’s growth, albeit with noticeable developmental lags in the latter stages. Spatially, economic performance demonstrated a declining trend from core urban centers like Urumqi City and Karamay City towards peripheral areas. From an ecological perspective, the distribution of resources exhibited a heterogeneous “M-V-W” pattern, characterized by significant disparities in the availability of natural resources and the occurrence of localized ecological deterioration. There is a notable and increasing degree of coupled coordination in regional synergistic development, which is primarily manifested in the delayed development of tourism. The combined development of the three subsystems is influenced by some factors, including environmental pollution, resources, economic quality, and industrial structure. Soot emissions, green space per capita in parks, and sulfur dioxide emissions are identified as key constraints. This study provides theoretical backing and empirical evidence for economic growth, the optimization of industrial structure, and the preservation of the ecological environment in arid and semi-arid regions globally.

The hotter the better: high mean annual temperature, not seed predation, hastens the decline of invasive Bromus tectorum

AbstractBromus tectorum invasion degrades biodiversity and ecosystem functioning in the Great Basin Desert. To explain, predict, and manage B. tectorum invasion, we must understand the biotic and abiotic factors that influence its establishment and persistence. We explored interactions between two key constraints for invaders in general and B. tectorum in particular: post-dispersal seed predation and climate, including mean annual temperature, rainfall, snowfall, and aridity. At six study sites in undisturbed, climax Artemisia tridentata communities across northern Nevada and Utah, we performed one-time additions of 100 B. tectorum seeds to microsites outfitted with either a dummy (“open”) cage that exposed seeds to rodent foraging, or a functional (“closed”) cage that protected them from rodent foraging. Living Bromus tectorum plants within experimental cages were censused one and 5 years after seed additions. At both 1- and 5-years censuses, and regardless of climate, B. tectorum densities were similar in open and closed microsites, suggesting that rodent foraging did not affect B. tectorum establishment or persistence. Compared to 1-year censuses, B. tectorum counts declined by 47% across all sites after 5 years, but declines were sharpest at sites with the highest mean annual temperatures. Taken together, our findings suggest that undisturbed, climax A. tridentata communities can resist B. tectorum expansion, and this resistance increases with mean annual temperature, not rodent foraging. We suggest that controlling nascent populations of B. tectorum may be particularly urgent in intact climax A. tridentata communities in relatively cool climates, where community-level resistance against B. tectorum persistence is lowest.

Assessment, Characterization, Identification and Prioritization of Major Constraints and Potentials of Three Selected Community Watersheds of Agarfa District, Bale Zone, Oromia, Ethiopia

The severity of land degradation due to different socioeconomic and biophysical pressures is a key problem encountered in watersheds. In addition, the lack of research-based references to a given community watershed, particularly with regard to socioeconomic and biophysical aspects, leads to the failure of the interventions. This study aimed to assess and characterize the socioeconomic and biophysical conditions of three selected (Oda Chefo, Wabe Seada, and Oda Nagelle) Community Watersheds of the Agarfa District of Bale Zone, Oromia, Ethiopia. Furthermore, it identifies and prioritizes constraints and opportunities for scientists, planners, intervention, impact analysis, and project performance evaluation. Communities' watersheds were selected and delineated, followed by household interviews, focus group discussions, and biophysical characterization to generate data. The study used a random sampling technique and a total of 121 sample sizes for socioeconomic data, watershed delineation, slope classification, soil type, and LULC classification map developed based on the preliminary outlet identified with the help of GPS reading and ArcGIS 10.5 software. The socioeconomic parameters were analyzed using SPSS version 20 software. The result of the baseline survey identified key constraints such as soil erosion, soil fertility decline, deforestation and climate change, feed and fodder shortage, livestock disease, human disease, unemployment, food insecurity, water shortage, lack of credit access, market, road, cooperatives, high input price, pest and disease, yield decline and lack of irrigation access. The results revealed that the availability of the labor force, local market accessibility, transport services, informal farmer cooperatives, livestock clinics, youth and women associations, and informal intuitions are the main opportunities in selected community watersheds. In conclusion, baseline surveying before any watershed management practice intervention plays ....

Transforming Locust Bean Processing: A Path to Profit for Elderly Women's Microbusiness in Sokoto, Nigeria

This study investigates the value addition potential of African locust beans (Parkia biglobosa) in Sokoto Metropolis, Nigeria, emphasizing the socio-economic characteristics of processors, cost-benefit analysis, and strategies for enhancing the value chain. Despite the nutritional and economic significance of locust beans, their market utilization remains constrained by traditional processing methods, inadequate packaging, and a lack of modern branding. Utilizing a multi-stage sampling technique, data was collected from 60 respondents, revealing that the locust bean processing industry is predominantly elderly female-driven, with limited modern educational and high family sizes. The total variable costs for processing were computed at ₦1,6888.49 revenue of ₦2,473 thus realizing a gross margin of ₦873.2. However, upon value addition of grinding and branded packaging, the variable cost rose to ₦7,220, with revenue from packaged Daddawa reaching ₦12,000, resulting in a Gross margin of ₦4,780. This underscores the financial viability of value addition through improved packaging and branding. The study further identifies key constraints including market disorganization and the need for better processing technologies. The findings advocate for strategic interventions to enhance the economic value of locust beans, promoting broader consumer acceptance and contributing to food security and economic development in the region.

Beyond hedging: China’s strategic ‘outbidding’ strategy in the semi-hierarchical Gulf region

The prevailing analytical approach within international relations scholarship has primarily framed China’s growing involvement in the Gulf region through a hedging strategy. Although this framework offers explanatory value, it misses the impact of China’s search for international hierarchy and Sino-US rivalry for subordinates in shaping China’s strategic policy choices in the Gulf. This article, anchored in hierarchy studies in international relations, posits that the intensifying global competition between the United States and China for influence over subordinate states has driven China to pursue an ‘outbidding’ strategy. In applying this approach, China provides Gulf states with more appealing economic, military, and technological incentives than the United States. Since Xi Jinping’s ascension to power in 2013, China has considerably expanded its regional influence by investing heavily in this strategy. However, the long-term effectiveness of this strategy hinges on overcoming two key constraints inherent to the semi-hierarchical order of the Gulf: the distinct strategic considerations of US allies and non-allies and the balancing dilemma that China confronts. This article substantiates its claims by analyzing official statements, policy documents, and academic literature on China’s Gulf policy.

Variable Stars in M31 Stellar Clusters from the Panchromatic Hubble Andromeda Treasury

Variable stars in stellar clusters can offer key constraints on stellar evolution and pulsation models, utilizing estimates of host cluster properties to constrain stellar physical parameters. We present a catalog of 86 luminous (F814W < 19) variable stars in M31 clusters identified by mining the archival Panchromatic Hubble Andromeda Treasury (PHAT) survey using a combination of statistical analysis of sparse PHAT light curves and difference imaging. We determine the evolutionary phases and initial masses of these variable stars by matching them with theoretical isochrones generated using host cluster properties from the literature. We calculate the probability of PHAT photometry being blended due to the highly crowded nature of cluster environments for each cluster-variable star, using these probabilities to inform our level of confidence in the derived properties of each star. Our 86 cluster-variable stars have initial masses between 0.8 and 67 M ⊙. Their evolutionary phases span the main sequence, more evolved hydrogen- and helium-burning phases, and the post–asymptotic giant branch. We identify numerous candidate variable star types: RV Tauri variables, red supergiants, and slowly pulsating B-type supergiants, along with Wolf–Rayet stars, α Cygni and Mira variables, a classical Cepheid, and a possible superasymptotic giant. We characterize 12 cluster-variable stars at higher confidence based on their difference image quality and lower blending probability. Ours is the first systematic study of variable stars in extragalactic stellar clusters leveraging the superior resolution of the Hubble Space Telescope and demonstrating the unique power of stellar clusters in constraining the fundamental properties of variable stars.

국제개발협력에서 디지털 공공재의 역할과 과제에 관한 연구

Purpose: This study examines the role and challenges of Digital Public Goods (DPGs) in international development cooperation. Emphasizing openness, it analyzes the socio-technical dimensions of DPGs, identifying key considerations and constraints for their development and application. Originality: DPGs are emerging as a strategic tool to achieve Sustainable Development Goals (SDGs) and address digital inequality. However, questions persist about whether technical openness alone can ensure successful development outcomes, suggesting the need for a broader analysis. Methodology: Using a socio-technical systems approach, this study reviews scholarly work on open-source software and open data in the Digital for Development (D4D) field over the past 15 years. Result: The findings show that DPGs enhance public service efficiency, support service expansion, and foster innovation through open access to data and knowledge. Despite these benefits, challenges such as technological complexity, infrastructure limitations, gaps in stakeholder awareness, capabilities, and trust, and hierarchical governance structures reveal tensions between technical and social dimensions. Conclusion and Implication: For effective implementation, DPGs require not only technical openness but also open governance structures, sustainable financial and technical capacities, and context-specific strategies. Governments and international organizations play a critical role as coordinators, while the formation of intermediaries and tailored strategies is crucial. This study contributes to the growing body of DPG research by offering a comprehensive analysis through a socio-technical lens.