Search Results (97)

Business model adjustment is a critical capability for microenterprises operating in import-dependent industries within emerging markets, and is increasingly recognised in the sustainable business model literature as a mechanism through which firms build economic resilience under resource constraints and volatile operating conditions. This paper examines how a specialty coffee microenterprise in Almaty, Kazakhstan, has adjusted its business model to create, deliver and capture value in a non-producing, landlocked economy characterised by rapid demand growth, currency volatility and high import dependency. The study answers two research questions regarding this case using Osterwalder and Pigneur’s business model canvas as the main analytical framework: (1) How did the case company set up its business model to create, deliver, and capture value? (2) In the context of Kazakhstani specialty coffee roasting, what possibilities and challenges influenced this business model? The analysis combines secondary market data with qualitative evidence from a semi-structured interview conducted in autumn 2025 with the founder of a nine-employee microenterprise that has evolved from a mobile coffee bar into a hybrid B2B–B2C roaster, café operator and e-commerce subscription service. Although Kazakhstan is not a coffee-producing country, its retail coffee market expanded from USD 326.71 million in 2019 to an estimated USD 554.5 million in 2025, with the fresh-coffee share rising from approximately 30% to 37%. The interview account describes a business model centred on locally roasted, traceable specialty coffee delivered fresh to a young, urban customer base, supported by educational and community-building activities. As reported by the founder, the enterprise faces structural challenges including exposure to international green-coffee price spikes—such as the record nominal highs of 354.32 US cents/lb reached in February 2025—currency-related cost volatility, logistical complexity across Eurasian transit routes and constrained access to growth-stage financing. Because the evidence base is a single founder interview combined with secondary market data, the paper does not independently verify the firm’s resilience, viability or financial outcomes. The findings are presented in the form of analytical generalisations—that is, generalisations relating to theoretical conclusions drawn from this specific case, rather than from a broader set of companies—which illustrate, based on the founder’s own account, how this micro-enterprise pursued a targeted, phased adaptation of its business model rather than a radical overhaul; the study does not independently verify resulting sustainability or resilience outcomes. As this is a case study, the present analysis does not allow us to determine the extent to which this model is representative of other micro-enterprises involved in coffee production, or of other non-manufacturing sectors in developing economies; the contribution of this study is empirical and contextual rather than theoretical: it extends the scope of business model analysis to under-researched geographical and institutional contexts and lays the groundwork for future comparative studies. Full article

This study examines whether the diffusion of financial technology expands or constrains private-sector credit across OECD economies, and whether regulatory quality conditions that relationship. Fintech diffusion is operationalized through a composite index of general digital-infrastructure indicators (internet use, mobile subscriptions, and ICT-service exports); this index proxies the broader digitalization environment rather than measuring payment-platform use, embedded credit, or digital lending directly. It conceptualizes digital payment ecosystems as complex financial systems in which technological diffusion, regulatory capacity, and credit dynamics co-evolve through feedback mechanisms. The policy discourse often assumes that digital financial inclusion automatically enhances resilience, yet evidence on credit expansion and systemic exposure remains contested. Using an unbalanced panel of 37 OECD economies from 2015 to 2024, comprising 356 observations, the analysis employs Driscoll–Kraay standard errors to address cross-sectional dependence within a common-slope two-way fixed-effects framework, along with panel quantile regression at the 10th, 50th, and 90th percentiles and Dumitrescu–Hurlin causality testing. Fintech diffusion is positively and statistically significantly associated with private-sector credit exposure, and this association is robust to a two-way fixed-effects specification. The quantile estimates show that the association is present at these selected points of the conditional distribution and strongest at its lower and upper tails, a pattern consistent with complex-adaptive-system dynamics in which effects vary across system states. Contrary to the negative-feedback expectation, the interaction between fintech diffusion and regulatory quality is positive, consistent with high-quality institutions enabling rather than restraining the translation of fintech into credit, though the observational design identifies this interaction rather than the mechanism producing it. The findings therefore shift the discussion from fintech as a stand-alone inclusion tool to fintech as a system-shaping force with implications for institutional resilience, macroprudential supervision, and systemic credit exposure. Because domestic credit to the private sector aggregates household and corporate lending, the policy implication below is framed at this aggregate level: digital payment infrastructure should be governed jointly with consumer protection, credit reporting, and financial-resilience mechanisms rather than promoted as a neutral technological upgrade. Full article

Freely accessible weather APIs are an attractive input for photovoltaic (PV) power prediction, yet how their reference-based error carries through—under temporal aggregation—into day-ahead PV energy is rarely quantified before model development. This study audits eight freely accessible weather-data services—seven forecast services and the Meteostat observational archive—and finds that, for the endpoints, subscription tiers, and collection period evaluated here, only two of the forecast services expose hourly global horizontal irradiance (GHI), while a third advertised irradiance field returns empty—itself a material result for municipal integrators. The two irradiance-capable services are propagated through a common physical PV model of the 548 kWp east–west rooftop plant being built on a university campus in Bratislava, Slovakia, against independent references (CAMS irradiance; NASA POWER temperature and wind). Throughout, “error” denotes discrepancy against the reference, not measurement truth. Over a common 62-day spring–summer window, the day-ahead daily-energy mean absolute error (MAE, relative to mean reference daily energy) is 10–11% for both sources; Open-Meteo’s winter-inclusive own window raises its value to about 13%. On the matched window, Open-Meteo has the lower hourly GHI RMSE (121 vs. 128 W·m⁻²), yet this advantage does not carry through to day-ahead energy—the point-estimate ordering even changes—and neither matched-window difference is statistically resolved. Because daily aggregation rewards low bias over low scatter, this ordering change is already present in daily GHI energy—before the PV conversion—so hourly irradiance accuracy alone does not determine day-ahead energy. Propagated input-data auditing is therefore an advisable step before ML-based PV forecasting and day-ahead scheduling of urban distributed PV. Full article

MQTT is widely used in Internet of Things (IoT) systems because of its lightweight publish–subscribe architecture and efficient support for resource-constrained devices. Although wildcard subscriptions simplify topic management, their impact on broker performance, stability, and security under authenticated high-load conditions has not been comprehensively investigated. Existing studies typically evaluate routing performance, security mechanisms, or broker scalability independently, leaving a limited understanding of their combined effects. This paper presents a systematic experimental evaluation of wildcard subscription behavior in an authenticated MQTT v5 environment. A controlled testbed employing TLS-based authentication and role-based access control was used to compare exact-topic subscriptions with single-level (+) and multi-level (#) wildcard subscriptions under progressively increasing workloads. Performance was evaluated using end-to-end latency, CPU utilization, throughput, delivery success rate, broker stability, and authorization exposure. The experimental results demonstrate that increasing wildcard-subscription complexity significantly increases routing overhead, resulting in higher latency and CPU utilization while reducing throughput and broker service capacity. Multi-level wildcard subscriptions consistently exhibited the greatest performance degradation and reached broker saturation at lower workload levels than exact-topic subscriptions, demonstrating that wildcard density compresses the broker’s operational stability region. The experiments also show that broad wildcard-based access control policies increase the risk of authorization leakage when improperly configured. These findings demonstrate that wildcard-subscription complexity is a critical determinant of MQTT scalability, broker stability, and security, and provide practical guidance for designing efficient and secure IoT messaging infrastructures. Full article

We develop a stochastic Stackelberg model of a subscription market with cancellation costs. A representative consumer chooses when to subscribe to and cancel a service as the utility derived from the subscription evolves according to a diffusion process, while the firm selects the subscription fee and cancellation cost to maximize its expected payoff. The consumer’s problem is equivalent to the classical real-options model of entry and exit under uncertainty with adjustment costs and exhibits a two-threshold policy with an inaction band and hysteresis. Unlike the standard formulation, in which the optimal thresholds are characterized implicitly through a system of nonlinear equations, we derive an explicit parametric solution in closed form. This solution reduces the firm’s optimization problem to a two-dimensional unconstrained problem and yields a detailed characterization of the optimal pricing policy. We show that the firm’s strategy exhibits three qualitatively distinct regimes depending on the initial utility level. For small utility levels, the optimal cancellation cost is zero. In an intermediate regime, the firm’s optimal policy induces the consumer to set the entry threshold equal to the initial utility level, resulting in immediate subscription. For sufficiently large utility levels, the firm induces permanent lock-in by setting a high cancellation cost and a low subscription fee: the consumer subscribes immediately and never subsequently unsubscribes. The transition between the latter two regimes is discontinuous and results from competition between two local maxima of the firm’s payoff function. We then extend the model to a heterogeneous population of consumers. The superposition of individual two-threshold subscription strategies generates a Preisach hysteresis operator describing the aggregate dependence of the firm’s revenue on the utility dynamics. The discontinuous regime transition persists under heterogeneity, demonstrating the robustness of the underlying mechanism. The Preisach representation predicts complex history dependence and long-term effects of temporary utility shocks. For a gamma distribution of consumer preferences, the firm’s expected payoff is obtained in closed form in terms of incomplete gamma functions. Full article

This study examines the risk of accidental subscription among elderly consumers in micro-drama platforms, addressing a critical gap in digital consumer behavior research as aging populations increasingly engage with subscription-based digital services. Using a quantitative approach, data were collected from 780 Thai respondents aged 60 and above through a structured online questionnaire. The data were analyzed using binary logistic regression to assess the effects of demographic factors (age, gender, education, and income) and behavioral factors (platform usage frequency, time spent per session, prior subscription experience, and impulse clicking behavior) on the likelihood of accidental subscription. The findings reveal that age, gender, platform usage frequency, time spent per session, and prior subscription experience significantly influence accidental subscription, while education, income, and impulse clicking behavior do not. Notably, frequent platform use and prior experience increase risk, whereas longer session duration reduces it, suggesting nuanced engagement effects. These results confirm that accidental subscription is a systematic and predictable outcome shaped by user characteristics and interaction patterns. The study contributes by extending consumer behavior research to unintended outcomes and offers practical implications for user-centered platform design, consumer protection policies, and targeted digital literacy initiatives, particularly in emerging digital economies. Full article

This research examines the transformation of film and TV series consumption within the contemporary media landscape, characterized by digital plenitude and Over-the-Top (OTT) dominance. The study investigates how users navigate the transition from linear broadcasting toward on-demand, platform-centric environments. Through an exploratory qualitative approach as the initial phase of a broader study, 18 semi-structured interviews were conducted with a demographically diverse group of Hungarian participants whose primary commonality is active film and TV series consumption. The findings highlight a rejection of traditional linear television, driven by an aversion to intrusive advertising and a demand for temporal autonomy. While mobile devices, particularly smartphones, are central to this shift, consumption remains predominantly stationary; users prioritize the flexibility of cross-device access within the domestic environment over mobile viewing during transit. Furthermore, the study identifies a growing friction caused by content fragmentation between different OTT platforms and rising subscription costs, while digital piracy persists as a marginal alternative. Ultimately, the study concludes that the modern audience acts as a strategic user navigating a complex ecosystem of excess. This underscores a fundamental shift where the cultural value of content is increasingly defined by the tension between individual agency and the systemic constraints of competing services. Full article

As mobility and transport activities declined during the COVID-19 lockdowns, transactions and operations became increasingly dependent on digitalisation. This shift reduced the need for carbon-emissions-intensive fossil-fuel-based transportation. Using a panel of thirteen (13) Southern African Development Community (SADC) countries over the period 2002–2021, the analysis captures financial inclusion through indicators of ATM density and commercial bank accessibility, while digital inclusion is measured using mobile phone subscriptions and internet penetration. On this basis, it investigates the effects of (a) financial and (b) digital inclusion, and (c) the moderation of financial and digital inclusion on transport-related carbon emissions. Employing the Panel Two-Stage Estimated Generalised Least Square (EGLS) analysis on data obtained from the World Bank database and Our World in Data, the findings reveal statistically significant outcomes. Increasing ATM accessibility, commercial bank branch accessibility and mobile phone subscription rates are associated with reduced transport-related emissions. In contrast, enhanced internet access does not contribute to transport-related carbon emissions. Moderation analyses further indicate that the interaction of the accessibility of ATMs or commercial bank branches with internet access do not lead to a further reduction in carbon emissions than the individual ones but might have a slightly opposing direction (that still do not annihilate the individual effects). Findings show that only the moderation of ATM accessibility and mobile subscriptions reduce transport-related carbon emissions further than the individual effects. Taking the economic development of most SADC countries in the last 20 years into account, the study recommends strategic investment in advanced digital innovations, particularly linked with mobile devices, to strengthen digital banking efficiency and improve customer service while supporting emission-reducing pathways. Full article

Server-side capacity dimensioning in operator-managed Over-The-Top (OTT) and Internet Protocol Television (IPTV) systems requires analytical methods that can account for heterogeneous traffic classes, differentiated subscription tiers, and strict grade-of-service (GoS) constraints. This paper proposes a capacity-planning framework based on a full-availability group (FAG) model and the Kaufman–Roberts recursion for evaluating class-specific blocking probabilities in multi-class OTT/IPTV delivery systems. The framework combines recursive occupancy-distribution computation with an incremental capacity search procedure to determine the minimum server-side delivery capacity satisfying differentiated blocking targets for free, standard, and premium subscription tiers. Three provisioning strategies are analysed within a unified model: dedicated server pools, a shared non-prioritised resource pool, and a shared prioritised resource pool. The analytical results are validated by discrete-event simulation and then used to compare the required capacities under the considered strategies. For the analysed six-class scenario, the shared server configuration reduces the required capacity by 3.82% compared with the dedicated architecture, while the prioritised shared configuration reduces it by 12.44%, while preserving stricter GoS protection for higher-priority traffic. The proposed framework provides network operators with a reproducible analytical tool for translating blocking-probability constraints into concrete server-capacity requirements and infrastructure-planning decisions. Full article

Streaming services have gained popularity due to their vast content library and convenience. To ensure continued patronage, service quality measurement is important. In this study, we ranked and determined how to maintain the competitiveness of streaming services using the analytic hierarchy process. Using focus group discussions and questionnaire administration, Netflix was found to have the highest perceived service quality, as measured by the consistency ratio and rating scales. Content library, quality of experience, and system availability were the top three service quality dimensions, while the top three sub-dimensions were quality of content, frequency of video freezing, and picture quality. These results allow companies to adjust their service strategies to suit the Philippine market. Full article

This paper empirically investigates the influence of specific direct sales approaches in attracting visitors to an agritourism operation and its profitability using survey data from the U.S. This study further examines the mediating role of the number of visits to a farm in the relationships between specific direct sales approaches and profitability. Agritourism operations enhance economic viability and sustain the business by opening farms to visitors for education, recreation, entertainment, and direct sales of farm products and services. The goal is to invite visitors to a farm and enhance income. Previous studies in the U.S. show that on-farm direct sales, in general, show a positive association, whereas off-farm direct sales show a negative association with the profitability of agritourism operations, along with many other factors. Farmers consider U-pick, sales through a farm stand/store, and subscription farming or community-supported agriculture (CSA) (on-farm pick-up) as on-farm, and CSA (off-farm delivery) and selling at a farmers’ market as off-farm direct sales approaches. However, which specific approach attracts visitors to a farm and generates profitability is not known. Multivariate analysis using the recently collected data from a U.S. national survey of operators reveals that on-farm direct sales such as a U-pick and a farm stand/store attracted significantly more visits to an agritourism operation, which ultimately yielded higher profitability. In contrast, the selling of produce at farmers’ markets attracted significantly fewer visits to the farm and reportedly reduced profitability. These results are adjusted for other factors including various agritourism experiences offered to the visitors. Moreover, as theoretically expected, the number of visits mediated the effects of specific direct sales (particularly a U-pick and farm stand sales) on profitability. This evidence has implications for agritourism operators, policymakers, and extension educators engaged in starting, expanding, and promoting direct sales via agritourism operations for their economic viability and sustainability. Full article

5G systems have delivered on their promise of seamless connectivity and efficiency improvements since their global rollout began in 2020. However, maintaining subscriber identity privacy on the network remains a critical challenge. The 3GPP specifications define numerous identifiers associated with the subscriber and their activity, all of which are critical to the operations of cellular networks. While the introduction of the Subscription Concealed Identifier (SUCI) protects users across the air interface, the 5G Core Network (CN) continues to operate largely on the basis of the Subscription Permanent Identifier (SUPI)—the 5G-equivalent to the IMSI from prior generations—for functions such as authentication, billing, session management, emergency services, and lawful interception. Furthermore, the SUPI relies solely on the transport layer’s encryption for protection from malicious observation and tracking of the SUPI across activities. The crucial role of the largely unprotected SUPI and other closely related identifiers creates a high-value target for insider threats, malware campaigns, and data exfiltration, effectively rendering the Mobile Network Operator (MNO) a single point of failure for identity privacy. In this paper, we analyze the architectural vulnerabilities of identity persistence within the CN, challenging the legacy “honest-but-curious” trust model. To quantify the extent of subscriber identities being utilized and exchange within various API calls in the CN, we conducted a study of the occurrence of SUPI as a parameter throughout the collection of 5G SBI (Service-Based Interface) Core VNF (Virtual Network Function) API (Application Programming Interface) schemas. Our extensive analysis of the 3GPP specifications for 3GPP Release 18 revealed a total of 4284 distinct parameter names being used across all API calls, with a total of 171,466 occurrences across the API schema. More importantly, it revealed a highly skewed distribution in which subscriber identity plays a pivotal role. Specifically, the “supi” parameter ranks 57th with 397 occurrences. We found that SUPI occurs both as a direct parameter (“supi”) and within 72 other parameter names that contain subscriber identifiers as defined in 3GPP TS 23.003. For these 73 parameter names, we identified a total of 8757 occurrences. At over 5.11% of all parameter occurrences, this constitutes a disproportionately large share of total references. We also detail scenarios where subscriber privacy can be compromised by internal actors and review future privacy-preserving frameworks that aim to decouple subscriber identity from network operations. By suggesting a shift towards a zero-trust model for CN architecture and providing subscribers with greater control over their identity management, this work also offers a potential roadmap for mitigating insider threats in current deployments and influencing specific standardization and regulatory requirements for future 6G and Beyond-6G networks. Full article

Entities using business models that integrate sustainability principles into business practice are gaining popularity through innovative measures. One such model is the subscription economy, in which customers pay regularly for access to products or services rather than purchasing them once. The study aims to present the subscription economy as a model that can help promote sustainable consumption. The paper uses a diagnostic survey method and a literature analysis and critique. Based on the literature on sustainable business models, the authors have shown that subscription economics, meeting the conditions of a sustainable model, can play an important role in promoting sustainable consumption (in terms of economic, social, and environmental rationality). The authors’ own research showed that Poles are very interested in the subscription model and its greatest importance in terms of economic rationality, which is the most important element of sustainable consumption. This also applies to the younger generation, which, despite being characterized by a high awareness of growing social and environmental problems, identifies sustainability as a secondary motivation to personal benefits such as financial security. Full article

This study examines the psychological mechanisms underlying service stickiness during the mature phase of the AI subscription economy, with particular attention to the paradox of subscription fatigue. To enhance conceptual clarity, AI-driven stimuli—specifically Algorithmic Curation and Technological Fluidity—are defined as perceived attributes at the individual level. Employing the Stimulus–Organism–Response (S-O-R) framework, the research explores how these perceived stimuli influence consumers’ internal states (Cognitive Efficiency and Serendipity) and subsequent behavioral responses (Service Stickiness). Empirical analysis using partial least squares structural equation modeling (PLS-SEM) on data from U.S. subscription service users yields several theoretical insights. Cognitive Efficiency is identified as the primary driver of stickiness, indicating that, in the context of subscription fatigue, the utilitarian benefit of reduced cognitive effort surpasses hedonic enjoyment. Additionally, the study identifies a “Frictionless Trap,” in which excessive Technological Fluidity negatively affects Serendipity (β = −0.195), suggesting that an entirely seamless experience may create a filter bubble that limits unexpected discovery. As a result, Serendipity does not significantly affect stickiness in the aggregate model. However, post hoc analysis demonstrates that Serendipity remains significant for high-income users, while Cognitive Efficiency is most influential in high-frequency utilitarian contexts, such as food services. These findings indicate that sustainable retention depends on reducing cognitive load while intentionally introducing friction to preserve opportunities for discovery. Full article

This study investigates performance overheads and security threats in 6th Generation Mobile Communication (6G) roaming environments, which are expected to enable services such as autonomous driving, smart cities, and remote healthcare that demand ultra-low latency and high reliability. To bridge the gap between standardization and real-world deployment, we built a realistic roaming testbed by separating the home and visited public land mobile networks (H-PLMN and V-PLMN) and simulating user equipment (UE) interactions. In this environment, we defined and measured roaming cost by comparing non-roaming and roaming procedures, and reproduced two Subscription Concealed Identifier (SUCI)-based denial-of-service (DoS) attacks: random generation and replay. Our experiments showed that intermediary functions such as the Security Edge Protection Proxy (SEPP) and Service Communication Proxy (SCP) introduced CPU/memory overhead and latency, highlighting performance degradation unique to roaming. Moreover, random SUCI generation concentrated load on the Authentication Server Function (AUSF) in the H-PLMN, whereas replay attacks distributed it across both the H-PLMN and the V-PLMN, consistently identifying the AUSF as a bottleneck. These findings demonstrate that roaming enlarges the attack surface and exposes vulnerabilities not fully addressed in current standards. We conclude that secure and reliable 6G roaming requires multi-layered defense strategies with inter-operator cooperation, providing empirical evidence to guide standardization and operational practice. Full article