Artículos Ingeniería

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Attitudes towards migration in a COVID-19 context: testing a behavioral immune system hypothesis with Twitter data
(2024) Freire-Vidal, Yerka; Fajardo, Gabriela; Rodriguez-Sickert, Carlos; Graells-Garrido, Eduardo; Muñoz Reyes, José Antonio; Figueroa, Oriana
The COVID-19 outbreak implied many changes in the daily life of most of the world’s population for a long time, prompting severe restrictions on sociality. The Behavioral ImmuneSystem (BIS) suggests that when facing pathogens, a psychological mechanism would be activated that, among other things, would generate an increase in prejudice and discrimination towards marginalized groups, including immigrants. This study aimed to test if people tend to enhance their rejection of minorities and foreign groups under the threat of contagious diseases, using the users’ attitudes towards migrants in Twitter data from Chile, for pre-pandemic and pandemic contexts. Our results appear to be mostly against the BIS hypothesis, with some faint exceptions, since threatened users increased their tweet production in the pandemic period, compared to empathetic users, but the latter grew in number and also increased the reach of their tweets between the two periods. We also found differences in the use of language between these types of users. Alternative explanations for these results may be context-dependent.
Mapping employment dynamics in public agencies with payroll data: A methodological framework with an application to Chile
(2024) Herrera Marín, Mauricio; Brieba, Daniel
This study introduces a novel, replicable methodology for analyzing employment dynamics within public sector agencies, focusing on turnover and staff longevity. The methodology is designed to be generalizable and applicable to diverse national contexts where detailed administrative data is available. Using payroll data from over 325,000 Chilean civil servants (2006—2020), we apply mixed-effects Cox survival models and linear mixed models to examine patterns of employment stability across state agencies. By incorporating Propen sity Score Matching, we further enhance the causal interpretation of turnover changes, especially in post-election years. Finally, we introduce two key metrics—Service Frailty and Relative Turnover Difference—to quantify long-term stability and short-term, post-electoral disruptions. Our findings highlight substantial differences in turnover patterns between regular and post-election years, as well as significant inter-agency heterogeneity in turnover and employee longevity, largely driven by latent agency characteristics. While major covariates like contract type and staff rank account for some variation, much of the disparity stems from agency-specific factors. This framework offers precise, cross-nationally comparable benchmarks for understanding public sector employment dynamics. Additionally, the methodology contributes to the literature by providing transparent and scalable tools for analyzing workforce stability across different contexts.
Condiciones de habitabilidad de viviendas para personas mayores. Revisión de criterios de diseño
(2024) Valderrama-Ulloa, Claudia; Schmitt, Cristian; Ortiz Velosa, Eliana; Marchetti, Juan pablo; Bucarey, Viviana
El articulo problematiza en la necesidad de estándares de diseño y pautas arquitectónicas para adaptaciones de viviendas de perso-nas mayores con y sin discapacidad para disminuir riesgos en las actividades diarias en sus viviendas. Para esto se utiliza el Modelo Clasificación Internacional del Funcionamiento, la Discapacidad y la Salud (CIF) identificando los problemas de funcionalidad y discapacidades que afectan en las actividades domésticas de personas mayores. El objetivo es proponer criterios de diseño que mejoren la calidad de vida de la población mayor al facilitar las actividades básicas e instrumentales de la vida diaria al interior de sus viviendas. Utilizando el análisis de contenido tanto del CIF, como las actividades básicas e instrumentales de la vida diaria, se proponen criterios de diseño para viviendas de personas mayores en general y para personas mayores con discapacidades cognitiva (Alzheimer), sensoriales (visuales y auditivos) y física (usuarios de silla de ruedas)
Game theory in the classroom: low cooperative relationships identify bullying patterns in elementary schools
(2024) Landaeta Torres, Víctor; Candia Vallejos, Cristian; Pulgar, Javier; Fábrega, Jorge; Varela, Jorge; Yaikin, Tamara; Monge, Cecilia; Rodriguez-Sickert, Carlos
Cooperation and bullying have a subtle yet important interaction that influences the social dynamics in elementary school classrooms. We investigate this interplay in a large sample of 1112 students across 47 public primary classrooms in Chile. Using a video game interface to create a dyadic, non-anonymous social dilemma, we map the cooperative social network within each classroom. In addition, we collect peer nomination data and use the Illinois Bullying Scale to categorize students as bullies, victims, or bully victims. Our results indicate that low levels of received cooperation significantly increase the likelihood of students being identified with the dual role of both bully and victim, known as the bully-victim profile. This negative relationship remains robust even after controlling for demographic and classroom context variables using multilevel regression models and is consistent when employing causal inference techniques such as statistical matching. We propose that the relationship between received cooperation and the bully-victim profile stems from the capacity of received cooperation to capture key factors influencing social relationships among students, such as popularity, prosociality, GPA, and aggressiveness. Our study contributes to the understanding of human interaction in educational settings and it offers a new framework for targeted interventions in primary education, providing insights for future educational policies and practices.
Leadership Development in Women STEM Students: The Interplay of Task Behaviors, Self-Efficacy, and University Training
(2024) Coluccio, Giuliani; Muñoz-Herrera, Sebastián; Adriasola, Elisa; Escobar, Elizabeth
This study explores the relationship between task-oriented behaviors, self-efficacy, and leadership emergence in women STEM students, grounded in the context of prototypical leadership theory and self-efficacy theory. Prototypical leadership theory emphasizes the alignment of leadership behaviors with group expectations, which, in STEM fields, are often task-oriented. The research examines how task-oriented behaviors, such as planning, decision-making, and supervision, influence women’s self-perception of leadership ability and their subsequent emergence as leaders. Our results show a positive relationship between task-oriented behaviors and self-efficacy and a positive relationship between self-efficacy with leader emergence, with academic experience further ngthening this link. As students’ progress through their programs, engaging in more teamwork and leadership tasks, their self-efficacy enhances, leading to stronger leadership emergence. Also, we found an indirect effect from task-oriented behavior to leader emergence via self-efficacy. These findings have significant implications for fostering leadership in women, particularly in STEM. The study calls for educational programs to enhance opportunities for women to develop these behaviors early on, ensuring their growth into leadership roles in STEM fields
Study of the Suitability of a Personal Exposure Monitor to Assess Air Quality
(2024) Aljofi, Halah E.; Bannan, Thomas J.; Flynn, Michael; Evans, James; Topping, David; Matthews, Emily; Diez, Sebastian; Edwards, Pete; Coe, Hugh; Brison, Daniel R.; Tongeren, Martie van; Johnstone, Edward D.; Povey, Andrew
Low-cost personal exposure monitors (PEMs) to measure personal exposure to air pollution are potentially promising tools for health research. However, their adoption requires robust validation. This study evaluated the performance of twenty-one Plume Lab Flow2s (PLFs) by comparing its air pollutant measurements, particulate matter with a diameter of 2.5 μm or less (PM2.5), 10 μm or less (PM10), and nitrogen dioxide (NO2), against several high-quality air pollution monitors under field conditions (at indoor, outdoor, and roadside locations). Correlation and regression analysis were used to evaluate measurements obtained by different PLFs against reference instrumentation. For all measured pollutants, the overall correlation coefficient between the PLFs and the reference instruments was often weak (r < 0.4). Moderate correlation was observed for one PLF unit at the indoor location and two units at the roadside location when measuring PM2.5, but not for PM10 and NO2 concentration. During periods of particularly higher pollution, 11 PLF tools showed stronger regression results (R2 values > 0.5) with one-hour and 9 PLF units with one-minute time interval. Results show that the PLF cannot be used robustly to determine high and low exposure to poor air. Therefore, the use of PLFs in research studies should be approached with caution if data quality is important to the research outputs.
Transcriptome Data Analysis Applied to Grapevine Growth Stage Identification
(2024) Altimiras, Francisco; Pavéz, Leonardo; Pourreza, Alireza; Yañez, Osvaldo; González-Rodríguez, Lisdelys; García, José; Galaz, Claudio; Leiva-Araos, Andres; Allende-Cid, Héctor
In agricultural production, it is fundamental to characterize the phenological stage of plants to ensure a good evaluation of the development, growth and health of crops. Phenological characterization allows for the early detection of nutritional deficiencies in plants that diminish the growth and productive yield and drastically affect the quality of their fruits. Currently, the phenological estimation of development in grapevine (Vitis vinifera) is carried out using four different schemes: Baillod and Baggiolini, Extended BBCH, Eichhorn and Lorenz, and Modified E-L. Phenological estimation requires the exhaustive evaluation of crops, which makes it intensive in terms of labor, personnel, and the time required for its application. In this work, we propose a new phenological classification based on transcriptional measures of certain genes to accurately estimate the stage of development of grapevine. There are several genomic information databases for Vitis vinifera, and the function of thousands of their genes has been widely characterized. The application of advanced molecular biology, including the massive parallel sequencing of RNA (RNA-seq), and the handling of large volumes of data provide state-of-the-art tools for the determination of phenological stages, on a global scale, of the molecular functions and processes of plants. With this aim, we applied a bioinformatic pipeline for the high-throughput quantification of RNA-seq datasets and further analysis of gene ontology terms. We identified differentially expressed genes in several datasets, and then, we associated them with the corresponding phenological stage of development. Differentially expressed genes were classified using count-based expression analysis and clustering and annotated using gene ontology data. This work contributes to the use of transcriptome data and gene expression analysis for the classification of development in plants, with a wide range of industrial applications in agriculture.
The Water Management Impacts of Large-Scale Mining Operations: A Social and Environmental Perspective
(2024) Arenas-Collao, Katherine; Valdés-González, Héctor; Reyes-Bozo, Lorenzo; Salazar, José Luis
This study investigates water consumption in two areas with limited water resources—the Salar de Atacama and Salar de Atacama-Vertiente Pacifico basins in Chile’s Antofagasta Region—with the aim of developing strategies that incorporate social and environmental aspects into water management. A qualitative approach was employed that involved a focus group with twelve water management representatives and surveys of the general population (468 responses). Additionally, the current state of water rights in the two basins was examined and the feasibility of the proposed strategies was assessed. The findings reveal that the mining industry’s development approach is mostly viewed as negative, mainly due to inadequate community engagement, confidential consumption data, and limited government oversight. The quantitative findings indicate that 53.8% of respondents see the main obstacle as the lack of a solution satisfying both parties. Additionally, 35.3%, 24.4%, and 22.4% believe transparency, objective information provision, and detailed resource usage disclosure by mining companies would help. Adopting a comprehensive water stewardship approach that considers social and environmental factors would enable a novel contribution to a more effective and sustainable water resource management system in northern Chile, mitigating communities’ negative perceptions of the industry and facilitating the integration of communities and involved agents. Therefore, improved management and transparent collaboration among stakeholders are essential for responsible water resource use in mining.
On a generalization of the Opial inequality
(2024) Bosch, Paul; Portilla, Ana; Rodriguez, Jose M.; Sigarreta, Jose M.
Inequalities are essential in pure and applied mathematics. In particular, Opial’s inequality and its generalizations have been playing an important role in the study of the existence and uniqueness of initial and boundary value problems. In this work, some new Opial-type inequalities are given and applied to generalized Riemann-Liouville-type integral operators.
Some new Milne-type inequalities
(2024) Bosch, Paul; Rodríguez, José M.; Sigarreta, José M.; Tourís, Eva
Inequalities play a main role in pure and applied mathematics. In this paper, we prove a generalization of Milne inequality for any measure space. The argument in the proof of this inequality allows us to obtain other Milne-type inequalities. Also, we improve the discrete version of Milne inequality, which holds for any positive value of the parameter p. Finally, we present a Milne-type inequality in the fractional context.
Inside the Black Box: Uncovering Dynamics and Characteristics of the Chilean Central Government Bureaucracy with a Novel Dataset
(2024) Brieba, Daniel; Herrera-Marín, Mauricio-René; Riffo, Marcelo; Garrido, Danilo
This article examines bureaucracies using a novel dataset of Chilean central government employees from 2006 to 2020. Unlike perception-based sources, this dataset provides objective, disaggregated, and longitudinal insights into bureaucrats’ characteristics and careers. The authors validate it against official employment statistics and conduct an exploratory and descriptive analysis, presenting six descriptive findings about the Chilean bureaucracy that cannot be discovered using available aggregate data. The analysis reveals significant degrees of personnel stability and professionalization in the civil service, but with considerable rigidity in careers and substantial interagency heterogeneity in turnover, wages, and exposure to political cycles. These findings suggest that the Chilean national bureaucracy is mostly well developed along Weberian lines, though not uniformly so. These measurements also serve as a benchmark for comparing other Latin American bureaucracies in the future.
On Shared Leadership Modeling: Contrasting Network and Dyadic Approaches
(2024) Coluccio, Giuliani; Muñoz-Herrera, Sebastián
Shared leadership is a dynamic phenomenon that has gained attention in behavioral science and management research over the last two decades. Network modeling is frequently employed to study this phenomenon, with the recent literature favoring a node-based approach over the traditional dyad-based approach. In this study, we investigate the differential impact of these approaches on shared leadership dynamics in student teams, specifically examining their effects on team task cohesion, team social cohesion, and team performance. We utilized multilevel structural equation modeling to compare node-based and dyad-based approaches in modeling shared leadership networks. Our findings indicate that increased leadership interactions positively influenced team performance and cohesion across both approaches. The dyad-based approach demonstrated a greater effect of leadership interactions on team performance, while leadership centrality significantly impacted performance exclusively in the node-based approach. This research contributes to the field by elucidating the differential impacts of node-based and dyad-based approaches, highlighting their strengths in capturing shared leadership dynamics and centrality effects. Our results underscore the critical importance of aligning theoretical foundations and research objectives with methodological choices in shared leadership studies. These insights enhance our understanding of shared leadership measurement and its implications for team outcomes, offering valuable guidance for future empirical investigations in this domain.
Long-term evaluation of commercial air quality sensors: an overview from the QUANT (Quantification of Utility of Atmospheric Network Technologies) study
(2024) Diez, Sebastian; Lacy, Stuart; Coe, Hugh; Urquiza, Josefina; Priestman, Max; Flynn, Michael; Marsden, Nicholas; Martin, Nicholas A.; Gillott, Stefan; Bannan, Thomas; Edwards, Pete M.
In times of growing concern about the impacts of air pollution across the globe, lower-cost sensor technology is giving the first steps in helping to enhance our understanding and ability to manage air quality issues, particularly in regions without established monitoring networks. While the benefits of greater spatial coverage and real-time measurements that these systems offer are evident, challenges still need to be addressed regarding sensor reliability and data quality. Given the limitations imposed by intellectual property, commercial implementations are often “black boxes”, which represents an extra challenge as it limits end users' understanding of the data production process. In this paper we present an overview of the QUANT (Quantification of Utility of Atmospheric Network Technologies) study, a comprehensive 3-year assessment across a range of urban environments in the United Kingdom, evaluating 43 sensor devices, including 119 gas sensors and 118 particulate matter (PM) sensors, from multiple companies. QUANT stands out as one of the most comprehensive studies of commercial air quality sensor systems carried out to date, encompassing a wide variety of companies in a single evaluation and including two generations of sensor technologies. Integrated into an extensive dataset open to the public, it was designed to provide a long-term evaluation of the precision, accuracy and stability of commercially available sensor systems. To attain a nuanced understanding of sensor performance, we have complemented commonly used single-value metrics (e.g. coefficient of determination, R2; root mean square error, RMSE; mean absolute error, MAE) with visual tools. These include regression plots, relative expanded uncertainty (REU) plots and target plots, enhancing our analysis beyond traditional metrics. This overview discusses the assessment methodology and key findings showcasing the significance of the study. While more comprehensive analyses are reserved for future detailed publications, the results shown here highlight the significant variation between systems, the incidence of corrections made by manufacturers, the effects of relocation to different environments and the long-term behaviour of the systems. Additionally, the importance of accounting for uncertainties associated with reference instruments in sensor evaluations is emphasised. Practical considerations in the application of these sensors in real-world scenarios are also discussed, and potential solutions to end-user data challenges are presented. Offering key information about the sensor systems' capabilities, the QUANT study will serve as a valuable resource for those seeking to implement commercial solutions as complementary tools to tackle air pollution.
QUANT: a long-term multi-city commercial air sensor dataset for performance evaluation
(2024) Diez, Sebastian; Lacy, Stuart; Urquiza, Josefina; Edwards, Pete
the QUaNt study represents the most extensive open-access evaluation of commercial air quality sensor systems to date. This comprehensive study assessed 49 systems from 14 manufacturers across three urban sites in the UK over a three-year period. the resulting open-access dataset captures high time-resolution measurements of a variety of gasses (NO, NO2, O3, CO, CO2), particulate matter (PM1, PM2.5, PM10), and key meteorological parameters (humidity, temperature, atmospheric pressure). The quality and scope of the dataset is enhanced by reference monitors’ data and calibrated products from sensor manufacturers across the three sites. this publicly accessible dataset serves as a robust and transparent resource that details the methods used for data collection and procedures to ensure dataset integrity. It provides a valuable tool for a wide range of stakeholders to analyze the performance of air quality sensors in real-world settings. Policymakers can leverage this data to refine sensor deployment guidelines and develop standardized protocols, while manufacturers can utilize it as a benchmark for technological innovation and product certification. Moreover, the dataset has supported the development of a UK code of practice, and the certification of one of the participating companies, underscoring the dataset’s utility and reliability
The social stratification of internal migration and daily mobility during the COVID-19 pandemic
(2024) Elejalde, Erick; Ferres, Leo; Navarro, Víctor; Bravo, Loreto; Zagheni, Emilio
This study leverages mobile data for 5.4 million users to unveil the complex dynamics of daily mobility and longer-term relocations in and from Santiago, Chile, during the COVID-19 pandemic, focusing on socioeconomic differentials. We estimated a relative increase in daily mobility, in 2020, for lower-income compared to higher-income regions. In contrast, longer-term relocation rose primarily among higher-income groups. These shifts indicate nuanced responses to the pandemic across socioeconomic classes. Compared to 2017, economic factors in 2020 had a stronger influence on the decision to relocate and the selection of destinations, suggesting transformations in mobility behaviors. Contrary to previously held beliefs, there was no evidence supporting a preference for rural over urban destinations, despite the surge in emigration from Santiago during the pandemic. This study enhances our understanding of how varying socioeconomic conditions interact with mobility decisions during crises and provides insights for policymakers aiming to enact fair and evidence-based measures in rapidly changing circumstances.
The Role of River Vigilance Committees to Address New Socio-Climatic Conditions in Chile: Insights from Ostrom’s Design Principles for Common-Pool Resource Institutions
(2024) Julio, Natalia; Álvez, Amaya; Castillo, Rodrigo; Iglesias, Kimberly; Rivera, Diego; Ochoa, Fernando; Figueroa, Ricardo
Chile is currently facing a mega-drought, which is expected to lead to a significant increase in the water stress level. Social conflicts related to water use are linked to the effects of climate change and a governance system marked by the privatization of the natural resources of public interest. This study aims to analyze whether the current Chilean water governance scheme can adapt to the effects of climate change through a critical observation of the role of the River Vigilance Committees (RVCs; private user organizations exercising the public function of water management), from the perspective of Ostrom’s design principles for long-enduring Common-pool Resource (CPR) institutions. We analyze legal approaches, management mechanisms, and decision-making processes under the socio-climatic conditions that the country is currently facing. The results indicate that, with a few exceptions, the Chilean governance system does not allow RVCs to effectively incorporate the design principles—and, therefore, to achieve adaptation—due to dispersed functions, the exclusion of water users, and a lack of planning at different levels. We propose that water governance should consider the creation of River Basin Boards with broader planning powers, as well as the incorporation of different relevant stakeholders.
Decadal Variability of Dry Days in Central Chile
(2024) Latoja, Daniela; Lillo-Saavedra, Mario; Gonzalo-Martin, Consuelo; Godoy-Faúndez, Alex; Somos-Valenzuela, Marcelo; Rivera, Diego
Dry days are crucial in precipitation variability and water scarcity, particularly in Mediterranean regions facing increasing aridity. Despite their importance, most research focuses on precipitation amounts and temporal dynamics. This study addresses this gap by analyzing dry days’ temporal and spatial variability in central Chile (32–40 S), a region experiencing prolonged drought. We examined dry day patterns from 1960 to 2021 using high-resolution gridded precipitation data, defining dry days with five precipitation thresholds (0.10, 1, 2.5, 5, and 10 mm/day). Principal component and trend analyses were employed to characterize spatial and temporal variability. Results reveal a spatial pattern of dry days closely following precipitation patterns, with more dry days in northern and coastal areas. The first principal component explains 70–80% of the variance, and clustering methods allowed the definition of five homogeneous regions with distinct monthly dry-day characteristics. Long-term trends show a significant increase in annual dry days south of 38°S, while trends are weaker and non-significant further north. Notably, trend direction is highly sensitive to the analysis period, with some regions showing opposing trends before and after 1982. The 2010–2019 megadrought is detectable in decadal anomalies. We found links between dry day anomalies and large-scale climate patterns, suggesting modulation by changes in subtropical and extratropical atmospheric circulation. This comprehensive characterization of dry day climatology and variability provides crucial insights for water resource management and climate change adaptation in central Chile and similar Mediterranean regions worldwide. Our findings highlight the importance of considering dry day frequency in drought assessment and water planning, contributing to a more nuanced understanding of precipitation patterns in Mediterranean climates.
Explicit Modeling of Multi-Product Customer Orders in a Multi-Period Production Planning Model
(2024) Palma, Cristian D.; Vergara, Francisco P.; Muñoz-Herrera, Sebastián
In many industries, companies receive customer orders that include multiple products. To simplify the use of optimization models for planning purposes, these orders are broken down, and the quantities of each product are grouped with the same products from other orders to be completed in the same period. Consequently, traditional production planning models enforce minimum demand constraints by product and period rather than by individual orders. An important drawback of this aggregation procedure is that it requires a fixed order fulfillment period, potentially missing opportunities for more efficient resource use through early completion. This paper introduces a novel mathematical formulation that preserves the integrity of customer orders, allowing for early fulfillment when possible. We compare a traditional linear programming model with a new mixed-integer programming approach using a sawmill case study. Although more complex than the traditional model, the proposed formulation reduces costs by approximately 6% by enabling early order completion and offers greater flexibility and control over the production process. This approach leads to better resource utilization and more precise order management, presenting a valuable alternative to conventional production planning models.
Green hydrogen integration in aluminum recycling: Techno-economic analysis towards sustainability transition in the expanding aluminum market
(2024) Reyes-Bozo, Lorenzo; Fúnez-Guerra, Carlos; Salazar, José Luis; Vyhmeister, Eduardo; Valdés-González, Héctor; Jaén Caparrós, María; Clemente-Jul, Carmen; Carro-de Lorenzo, Francisco; Simón-Martín, Miguel de
The use of aluminum-based products is widespread and growing, particularly in industries such as automotive, food packaging, and construction. Obtaining aluminum is expensive and energy-intensive, making the recycling of existing products essential for economic and environmental viability. This work explores the potential of using green hydrogen as a replacement for natural gas in the smelting and refining furnaces in aluminum recycling facilities. The adoption of green hydrogen has the potential to curtail approximately 4.54 ktons/year of CO2 emissions, rendering it a sustainable and economically advantageous solution. The work evaluates the economic viability of a case study through assessing the Net Present Value (NPV) and the Internal Rate of Return (IRR). Furthermore, it is employed single- and multi-parameter sensitivity analyses to obtain insight on the most relevant conditions to achieve economic viability. Results demonstrate that integrating on-site green hydrogen generation yields a favorable NPV of 57,370, an IRR of 9.83%, and a 19.63-year payback period. The primary factors influencing NPV are the initial electricity consumption stack and the H2 price.
Assessing the effectiveness of static heuristics for scheduling lumber orders in the sawmilling production process
(2024) Vergara, Francisco P.; Palma, Cristian D.; Nelson, John D.
Although optimization models can be used to plan the production process, in most cases static heuristics, such as earliest due date (E), longest processing time (L), and shortest processing time (S), are used because of their simplicity. This study aims to analyze the production cost of the static heuristics and to determine how this cost relates to the size of the production orders in the sawmilling industry. We set a planning problem with different orders and due dates and solved it using two cost-minimization models to compare their solutions. The first was a planning model (PL) where orders were split up into products demand by period, and the second, a planning scheduling (PS) where the sequence of processing orders based on static heuristics was assumed as known. In the latter, the minimum production cost for each static heuristic was found. In both models, the same resource constraints were assumed. The costs showed no significant changes based on order sizes. However, 0,5 % of orders were delayed using PS-E, and 17 % of orders were delayed using PL. PL was an efficient solution method when changing the orders´ size and when looking for the best static heuristic to process the orders. However, PS-E showed the ability to reduce the backlog close to zero while the PL backlog ratio was 17 %. No penalties were applied to backlogs due to their subjective nature; however, when shortages occurred, the demand was unmet or backlogged with substantial costs. Thus, in case the proposed method is adopted using a conservative backlog cost, a sawmill producing under the cut-to-order environment that produces 300000 m3 /year would reduce backlogged orders by 51000 m3. If the holding lumber cost is 2 $/m3, annual savings would be $408000.

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