Industrial Workers Research Articles

Radios y Cacerolas

This article elaborates a feminist digital activist perspective on the Colombian national strike of 2021 through the work of two women-led collectives (colectivas) in which I participated from afar, as part of the Colombian diaspora. Radio Lila is a collective of women living in Cali’s oriente, and Cacerola Collective is formed by Colombians in the diaspora, mostly people working in the creative industries. Through the study of these colectivas’s praxis, this article argues that women-led collectives use digital tools and the internet not only to set up political actions but also to create online places for care and mourning. This argument makes conspicuous how there is a gap in the research on digital activism, concerning the emotional tools activists seek to transit political uprisals and their aftermaths. In other words, we see here how feminist research on social media can also focus on retreating, going offline, as a way of personal and communal care.

Adopting prospective antimicrobial stewardship (AMS) practice in high-risk immunosuppressed groups: an urgent call to action in the era of antimicrobial resistance (AMR).

Life-saving immunosuppressive treatments including intensive chemotherapy and bone marrow transplantation expose patients to a considerable risk of death from infection globally. With evolving AMR and transmission, this could spell disaster for patients across the world and society at large. Antimicrobial stewardship (AMS) and prompt appropriate management of potentially fatal, emergent infections are essential. It is now apparent that antibacterial prophylaxis in patients with haematological cancer may not provide survival benefit while simultaneously increasing risks for AMR carriage. With evolving AMR and increasing immunosuppressed populations across the world, we must institute robust AMS practices. Significant resources are used to combat the impact of AMR on immunosuppressed patients. For lower-middle income countries (LMICs) these resources may not be available and as such the impact caused by AMR is greater. By considering the patient journey holistically we consider risk of infection presented to patients temporally and geographically. A short-term and easy to implement approach of multi-disciplinary team (MDT)-style advance care planning for infection is advocated. Antimicrobials, when used appropriately, enable healthcare procedures to occur and exist. Indeed, the very future of clinical medicine will rely on this yet to be realized value of enablement. Proactive effort and change must occur across all sectors with holism; hence our impetus for convening a joint industry and clinical working group. With at-risk immunosuppressed groups being a sentinel for change, awareness and implementation of patient-centric actions for infection are essential and our recommendations serve as an urgent call to action.

Dynamics of atmospheric emissions and meteorological variables in Bangladesh from pre-to post-COVID-19 lockdown

Following the COVID-19 restrictions, there was a sharp decline in global air quality and related environmental metrics. Due to the limited availability of in situ atmospheric data in Bangladesh, this study collected data on various air pollutants (NO2, SO2, CO, and PM2.5), greenhouse gases (CO2, CH4, and O3), as well as meteorological variables like Land Surface Temperature (LST), Relative Humidity (RH), Precipitation, surface albedo and Aerosol Optical Depth (AOD) from different datasets by Google Earth Engine (GEE), the International Energy Agency (IEA), NASA Giovanni, and NASA Power Access Viewer, covering periods before (2019), during (2020), and after (2021–2023) the COVID-19 lockdown in Bangladesh. GIS-based assessment alongside Principal Component Analysis (PCA) has been performed to explore the patterns, trends and correlations among the observed variables. Results showed in 2020 compared to 2019, NO2, SO2, CO, PM2.5, and CO2 concentrations decreases by 1.94, 16.67, 1.95, 2.08, and 6 %, respectively, while CH4 and O3 continued to rise. Meteorological variables exhibited a 0.16 °C decreases in LST, 6.4 % increases in RH, a 6 % reduction in AOD, and 6.36 % declines in surface albedo. Post-lockdown in 2021, air pollutants surged (NO2, SO2, CO, and PM2.5 increases by 17.3, 23.6, 0.6, and 8.3 %, respectively), with CO2, LST, and AOD rising by 8.5 %, 0.13 °C, and 8.3 %, and a slight 0.46 % decrease in RH compared to 2019 due to resuming more economic activities, transportation and industrial production works. The years 2022–2023 saw slight improvements in most variables except CH4, though concentrations did not revert to those of 2019. The findings of correlation coefficients revealed that pollutants and GHG are highly correlated with the meteorological variables specially with RH. This study underscores the substantial shifts in atmospheric variables from pre-to post-lockdown periods, offering valuable insights for more effective management of the greenhouse effect and air pollution control strategies.

A Comparative Study of Different Unorganized Sectors’ Workers in India to Identify Musculoskeletal Disorder Prevalence through Empirical Survey and Deep Learning Methods

Background:: Musculoskeletal disorders (MSDs) are a group of non-fatal injuries that can occur as a result of various repetitive workplace activities, mainly in unorganized sectors. Workers who engage in highly repetitive activities involving constant hand effort, localized mechanical pressure, and vibration are more prone to developing these disorders. Objective:: The objective of this research was to determine the prevalence of MSDs among workers in various unorganized sectors in India who perform hand-intensive occupations. Method:: A cross-sectional study was conducted, involving 340 workers from diverse groups such as sugarcane farmers, footwear industry workers, and tarpaulin weavers, to accomplish this goal. Data for the survey was collected using a questionnaire. Additionally, a comprehensive time study and a deep learning-based posture detection study were conducted on the different activities performed during the workers' occupational tasks. The chi-square test was used to assess the relationship between discomfort and work repetitiveness. Result:: The data analysis revealed that the working activities (especially cutting/harvesting, rubber cutting, etc.) of unorganized sector workers were repetitive, with more than half of each activity’s work cycle involving a similar usage pattern. Furthermore, a significant association was observed between the level of discomfort and work repetitiveness among workers in different sectors (sugarcane farmers: p < 0.01, footwear industry workers: p < 0.05, tarpaulin weavers: p < 0.05). Consequently, it can be concluded that prolonged occupational activities involving repetitive and prolonged standing may contribute to the occurrence of MSDs. Conclusion:: Ergonomic interventions/modifications in the form of patent work will be necessary to prevent these issues in the near future.

To study the influence of shift working of IT Workers based on Occupational health effects & compare with health effects of Industrial workers”

To study the influence of shift working of IT Workers based on Occupational health effects & compare with health effects of Industrial workers”

Effect of vitamin supplementation and exposure-free break on hematological, Biochemical, and pathological parameters in male Wistar rats exposed to quinalphos

ABSTRACT Background: India is a land of agriculture, where the economy is based on cash crop cultivation. The wide and chronic use of pesticides for agriculture, domestic, and industrial purposes without protective measures has led to subsequent adverse health effects and further evaluation. It has become a major concern of public health due to its usage throughout the year among pesticide industrial workers, distributors and retail shopkeepers, agricultural field workers, and sprayers. Among the different types of pesticides (organochlorines, organophosphorus, carbamates, and pyrethroid compounds) used, quinalphos is the most common organophosphorus compound used in South India. These compounds were known to produce oxidative damage in the liver, kidney, bone marrow, brain, and intestine. Nonenzymatic antioxidants like vitamin C and E were found to alleviate the oxidative damage imposed by these pesticides. Thus, the present study aims to evaluate the effect of oral supplementation of vitamin E and vitamin C in comparison to exposure-free days on complete blood count, antioxidant enzymes, liver enzymes, and histopathological changes in the liver following exposure of male Wistar rats to quinalphos. Materials and Methods: This experimental study was done at XXXX after getting scientific and ethical committee clearance. A total of 24 adult male Wistar rats were divided randomly into four groups, with six in each group. Group A consists of animals not exposed to quinalphos for 60 days (control group), group B exposed to quinalphos for 60 days, group C exposed to quinalphos orally only for the first 30 days with exposure-free days for the next 30 days, and group D exposed to quinalphos orally for 60 days along with vitamin E and vitamin C oral supplementation. During exposure, quinalphos was administered at the dose of 3 mg/kg/day mixed with drinking water through oral gavage. Animals were sacrificed at the end of 60 days. Blood was collected by direct cardiac puncture, and the liver tissue was used for histopathological investigation. Data were analyzed with one-way ANOVA and post hoc Turkey’s test for intergroup comparison using SPSS 21.0 software. Results: RBC count (P = 0.011), Hb % (P = 0.000), and hematocrit (P = 0.000) were significantly reduced, whereas WBC count (P = 0.005) and neutrophil % (P = 0.001) significantly increased in the quinalphos-exposed group (group B) compared to other three groups. Liver enzymes, SGPT (P = 0.028) and SGOT (P = 0.343), were elevated, and the antioxidants catalase (P = 0.000) and glutathione peroxidase (P = 0.000) were significantly reduced in the quinalphos-exposed group when compared to the control and exposure free group. Histopathology of the liver showed diffuse necrosis of the hepatocytes with central venous congestion in quinalphos-exposed (group B) compared to the other three groups. The exposure-free group (group C) has shown better histopathological changes when compared to quinalphos exposure with (group D) and without (group B) vitamin C and E supplementation group. Conclusion: Quinalphos exposure orally results in anemia, leucocytosis with neutrophilia, liver damage, and oxidative stress. As evidenced by liver histopathology and altered antioxidant enzymes in the supplementation group compared to the group with exposure-free days, the toxic effects of quinalphos were less during exposure-free days. Thus, people occupationally exposed to quinalphos can alleviate the ill effects by having exposure-free days as interval breaks to remove the toxic accumulation of organophosphorus compounds.

An initial approach to industry 5.0

Industry 5.0 focuses on human-system collaboration and a more integrated approach to manufacturing and services. Digital twin is a technological advancement positioned to propel Industry 5.0 by making way for newer implementations and greater cyber-physical connections within a system. Digital twins will lead the way as Industry 5.0 encourages a closer integration of digital and physical systems. They will act as a link between the digital and physical worlds, giving each, real-time information and insights. Within Industry 5.0, digital twins are essential for establishing communication between the digital and physical realms as well as for facilitating human-autonomous system cooperation and cohabitation. Industry 5.0 highlights the requirement for adaptable manufacturing to satisfy specific client needs. Manufacturing processes can be swiftly and effectively adjusted with the use of digital twins. Industry 5.0 relies heavily on digital twins to help businesses adapt to the changing manufacturing environment and use data-driven insights to increase productivity, flexibility, and human-robot collaboration. The aspects of industry such as the commissioning and the automation of the Industrial Work floor processes are to be integrated with the digital twin. The digital twin allows for the virtual commissioning and integration of humans through interactive mixed reality that transcends the user experience making the process of integration and data (instruction) transfer seamless. The main focus of the paper was on utilizing the digital twin for the connection of various aspects of an industrial factory to establish control and real time monitoring for a Cyber-physical system. The digital Twin of a material handling system was developed and used for virtual commissioning and Mixed Reality integration and exploration.

Electromyographic analysis of bilateral upper trapezius muscles at different levels of work-pace among sewing machine operators

Workers are driven to work faster in the industrial work environment to meet high productivity targets. An increased work pace leads to increased muscle activation. However, the effect of work pace on bilateral upper trapezius muscles during sewing machine operation in an industrial work environment has not been thoroughly investigated in experimental studies. Therefore, this research aims to conduct an experimental study to analyze the bilateral upper trapezius muscle activity of industrial sewing machine operators at different levels of work pace. Thirty subjects (15 males, and 15 females) continuously performed the sewing operation for two hours in an industrial work environment. Experiments were conducted for two levels of work pace i.e. low pace (100% of standard cycle time) and high pace (120% of standard cycle time). Electromyographic signals were recorded from the bilateral upper trapezius muscles. The EMG amplitude (RMS) among the muscles was computed. A statistically significant (p < 0.05) increase in muscle activity was observed with an increased work pace. In this study, right upper trapezius muscle activity increased by 30.4% during high work pace tasks compared to low pace, while the left upper trapezius showed a 24.12% increase. The right upper trapezius showed a mean difference of 0.696 (%MVC), and the left upper trapezius showed 0.399 (%MVC), both indicating greater activity during high-pace tasks. The increase in muscle activity with time indicated the presence of muscle fatigue among sewing machine operators. Furthermore, higher muscular activity was observed among females than males. This research highlights the critical need to balance productivity goals with the health and safety of workers, reducing the risk of muscle fatigue and associated work-related musculoskeletal disorders.

МЕТОДИ І ПРАКТИКИ ВПРОВАДЖЕННЯ ТА ЗАСТОСУВАННЯ РІЗНИХ ТИПІВ ШТУЧНОГО ІНТЕЛЕКТУ І НАУКИ ПРО ДАНІ ДЛЯ РІШЕННЯ ПРОБЛЕМ У ВОДНІЙ ІНФРАСТРУКТУРІ

The subject of the study in this article was the practice of implementing and applying various types of artificial intelligence and data science to detect leaks from water supply networks, to monitor freshwater conditions and to detect pollution, clean freshwater bodies from waste from industrial and mining enterprises, control freshwater flow and develop more efficient water filtration methods. The article identifies the advantages and disadvantages of the practice of introducing and applying various types of artificial intelligence and data science technologies to automate traditional methods of monitoring, control and related work in the water industry. The article addresses the following objectives: to substantiate the effectiveness of implementation of various types of artificial intelligence technologies and data science methods and their practical application with software and hardware technologies to automate traditional methods of performing work in the water industry. To solve the tasks set, the methodology used was based on general scientific and special research methods, such as theoretical methods (analysis, explanation, generalisation, comparison). The use of this approach allowed us to obtain the following results: the features that affect the accuracy of the analysis of collected data used by technologies of various types of artificial intelligence and data science methods were identified. Practices and methods for more efficient and accurate application of this technology are reflected. Scientific data are analysed. The study allowed identifying the practical opportunities and problems of this technology. Recommendations for the effective use of this technology have been developed. The factors that influence the effective use of this technology in industry are identified.

Art healing practice program for rail worker mental health

At present, China's rail transportation industry is in a rapid development stage, and the work pressure of rail transportation workers is increasing, and mental health problems are becoming more and more prominent. This study adopts the questionnaire research method to investigate the main factors affecting the mental health of the employees of five rail transit enterprises in Guangdong Province, China and their attitudes towards art healing, and constructs a factor model to conduct a comprehensive analysis by using the SPSS software, which reveals that the work intensity, work pressure and life pressure are the main factors affecting the mental health of the rail transit employees, and that most of the rail transit employees are willing to accept the art healing and believe that art healing is a positive and effective way to solve the mental health problems. Most of the rail transit workers are willing to accept art healing and believe that art healing is a positive and effective way to solve mental health problems. When designing art healing programs, it is necessary to give full consideration to the high work intensity of rail transit workers, and in the case of fewer art healing programs in the existing rail transit industry, it is necessary to actively explore leisure and relaxing art healing programs for the workers in the rail transit industry in order to alleviate and heal the psychological problems of rail transit workers, and to assist in the healthy development of the rail transit industry. The healthy development of rail transportation industry.

Design of an Advanced Optimal Fuzzy Controller For a Binary Distillation Column

The most common control philosophy followed in the chemical process industries is the SISO system using the conventional PID controller algorithms. One drawback is relying on models for both control and design work in Chemical process industries (CPI) is that many problems are very complex and accurate models are difficult, if not impossible to obtain. To overcome these problems, it will be helpful to apply techniques that use human judgment and experience rather than precise mathematical models, which in the major cases deduced from the linearization of the system and simplification hypothesis. The fuzzy logic systems are capable of handling complex, nonlinear systems using simple solutions. However, obtaining an optimal set of fuzzy membership functions is not an easy task. In this chapter a solution based on artificial intelligence is proposed to improve the control of a binary distillation column. The solution is based on the use of the advantages of both fuzzy logic and genetic algorithms. The fuzzy logic is used as a supervisory PI controller that is a simple PI controller that generally used in controlling distillation columns with parameters deduced from the fuzzy supervisor. The membership functions shape is deduced by using research algorithms based on hierarchical genetic algorithms. The results show that the Fuzzy supervisory PI controller provide an excellent tracking toward set point change.

은행업 종사자의 직무수행능력이 잡크래프팅에 미치는 영향 : 자기개발욕구의 매개효과를 중심으로

This study aims to provide a direction for human resource management as part of the crisis response plan for the Korean banking industry in response to the rapidly changing industrial structure. The study aimed to verify the causal relationship between interpersonal skills and problem-solving skills among job performance abilities and job crafting among banking industry workers, and to examine the mediating effect of self-development desire between job performance abilities and job crafting. For this study, a questionnaire was administered to 260 employees of domestic commercial banks, and the collected survey data was analyzed using SPSS (Ver. 24.0). As a result of this analysis, first, the interpersonal skills of banking workers were found to have a positive (+) effect on job crafting, second, the problem-solving skills of banking workers were found to have a positive (+) effect on job crafting, third, the desire for self-development was found to have a significant complete mediating effect between interpersonal skills and job crafting, and fourth, the desire for self-development was found to have a significant partial mediating effect between problem-solving skills and job crafting. The implications of this study are as follows: First, it is necessary to enhance interpersonal skills and problem-solving skills, which are sub-components of the job performance ability of banking workers, and to promote job crafting to improve innovation and efficiency in the banking industry; second, it is necessary to strengthen the human resource capacity of the organization by providing self-development programs that improve interpersonal skills and problem-solving skills; and third, it is necessary to create an organizational culture that encourages employees to activate job crafting by enhancing the desire for voluntary self-development among banking workers, as job crafting can contribute not only to individual growth but also to innovation and performance improvement of the organization. This study has academic distinction in that it conducted research on job crafting by limiting the research subjects to banking workers, clarified the causal relationship between the research subjects’ job performance ability and job crafting, and verified the mediating effect of the desire for self-development between job performance ability and job crafting, thereby providing implications.

Effect of Sound Absorption on Noise Reduction in the Automotive Industry

Industrial noise is one of the most common physical factors that cause annoyance and damage to workers' health in the long term. Precautions should be taken to reduce noise and to improve acoustic performance in industrial working environments. This paper aims to analyze the acoustic performance of the automotive industry contributes to the global outcomes of sustainability and develop strategies for improving the quality of the working environment through improvement scenarios. For this purpose, the automotive industry in Türkiye was examined as a case study. In-situ acoustic measurements were made in the seat manufacturing unit of an automotive factory, and the current situation was transferred to the simulation program. The effects of acoustic improvements on A-weighted sound pressure level and reverberation time at mid-frequencies (500, 1000, 2000 Hz) were investigated through three scenarios. In the investigations, noise distributions were carried out through noise mapping. The A-weighted sound pressure levels in the automotive industry were reduced by approximately 15 dB. As a result of the study, suggestions for noise control precautions and their effects on the automotive industry seat manufacturing unit are presented.

Strategies for mitigating challenges facing the effective collaboration between technical colleges and industries for skill acquisition in motor vehicle mechanic works in Edo state, Nigeria

This study investigated the strategies for mitigating challenges facing collaboration between technical colleges and industries for skill acquisition in motor vehicle mechanic works in Edo State. Three research questions and one hypothesis tested at 0.05 level of significance were used. The study adopted a descriptive survey research design with a population of 80 respondents, which comprised technical teachers and managers of automobile industries in Edo State. The entire population was adopted as the sample because it is of manageable size. A structured questionnaire with 17 items arranged in clusters was used as instrument for data collection. The instrument was validated by three experts. Cronbach alpha coefficient formula was used test the reliability of the instrument and it yielded an overall coefficient of 0.85. The findings of the study revealed that collaboration between technical colleges and industries for skill acquisition is facing a lot of challenges, such as industry’s unwillingness to support students’ industrial work experience scheme, amongst others. Based on the findings, it was recommended, amongst others, that industries should establish school-based workshop as a strategies for improving collaboration between technical colleges and industries for skills acquisition.

Prevalence of Pulmonary Disorders in Sanitizer Industrial Workers

Prevalence of Pulmonary Disorders in Sanitizer Industrial Workers

A new approach to assessing the consequences of radiation on the eye

The authors propose a new approach to assessing the consequences of exposure to ionizing radiation on the structures of the eye. The approach is based on the results recently obtained by the authors together with employees of the Joint Institute for Nuclear Research in Dubna, according to which radiation exposure causes oxidation of the bisretinoids contained in the structures of the eye - the retina and retinal pigment epithelium. As a result of this oxidation, the fluorescence spectrum of bisretinoids shifts to the blue region of the visible spectrum. The shift in the fluorescence spectrum can be recorded non-invasively using the method of recording fundus autofluorescence, which is currently generally accepted in ophthalmology. Since the oxidation of bisretinoids occurs during radiation exposure, it becomes possible almost immediately after irradiation to assess the degree of impact of ionizing radiation on both the structures of the eye and the body as a whole. There is no analogue to such a non-invasive assessment of the effects of radiation on the body. The proposed approach may become important for assessing the radiation safety of nuclear industry workers, astronauts, and patients undergoing proton or gamma therapy.

Wearable Sensors for Healthcare of Industrial Workers: A Scoping Review

Background and Objectives: This scoping review evaluates the use of wearable sensor technologies for workplace safety and health monitoring in industrial settings. The aim is to synthesize evidence on the impact of these sensors and their application in high-risk environments. Materials and Methods: Following the PRISMA guidelines, a systematic search across four international electronic databases yielded 59 studies, of which 17 were included in the final review. The selection criteria involved studies that specifically utilized wearable sensors to monitor various health and environmental parameters relevant to industrial workers. Results: The analysis categorizes wearable technologies into five distinct groups based on their function: gas monitoring technologies, heart rate and physiological data collection, fatigue and activity monitoring, comprehensive environmental and physiological monitoring, and advanced sensing and data collection systems. These devices demonstrated substantial benefits in terms of early detection of health risks and enhancement of safety protocols. Conclusions: The review concludes that wearable sensor technologies significantly contribute to workplace safety by providing real-time, data-driven insights into environmental hazards and workers’ physiological status, thus supporting proactive health management practices in industrial settings. Further research is recommended to address the challenges of data privacy, sensor reliability, and cost-effective integration to maximize their potential in occupational health safety.

The prevalence of occupational injuries and associated risk factors among workers in iron and steel industries: a systematic review and meta-analysis

BackgroundThe iron and steel industries are among the most dangerous workplaces in the world compared to other manufacturing industries. Workers are exposed to multiple occupational hazards, which predispose them to high risks of both fatal and non-fatal injuries. Currently, the data on the global prevalence and associated risk factors for occupational injuries in the iron and steel industries is fragmented and incomplete. This study was undertaken to address this issue by pooling data relating to the prevalence of occupational injuries and its associated factors among workers in iron and steel industries studies around the world.MethodsThe search was conducted systematically using PubMed, HINARI, EMBASE and Google Scholar for published studies in English that reported on occupational injuries and associated risk factors among workers in iron and steel industries. MetaXL version 5.3 software was used in the meta-analysis to estimate the pooled prevalence of occupational injuries and associated risk factors among workers in the iron and steel industries. The study protocol has been registered with PROSPERO, number CRD42022344258.ResultsOf the 447 articles identified, 15 studies from 9 countries met the inclusion criteria. The pooled prevalence estimate of occupational injury was 0.55 (95% CI: 0.15, 0.93). The pooled results indicated that the odds of having an occupational injury were 4.06 times higher among workers who did not use personal protective equipment compared to those who used such equipment. Likewise the odds of occupational injuries was increased by 1.65 among night shift workers compared to the counterpart.ConclusionsThe global prevalence of occupational injuries in iron and steel industries was 55%. The results indicate that night work shift and the lack of use of personal protective equipment has a higher impact than other factors in the occurrence of occupational injuries in the iron and steel industries.

Clustering Profiles of Domestic Seasonal Workers in the Hospitality Industry Based on Quality of Working Conditions and Return Intentions

ABSTRACT This study aims to examine the perception of work-related attitudes and behavioral outcomes among domestic seasonal hospitality workers, categorized based on their cluster distribution. The research identifies two distinct profiles of domestic seasonal workers (satisfied – SAT, and dissatisfied – DISAT), revealing significant differences in their perceptions of both attitudinal and behavioral outcomes within the hospitality industry. This finding challenges the existing knowledge by highlighting the limitations of a one-size-fits-all approach to managing seasonal workers. The study underscores the necessity for tailored strategies that recognize and cater to the specific needs of different worker profiles. By addressing these distinct needs, HR managers can significantly enhance the likelihood of seasonal domestic workers returning for subsequent seasons or opting for permanent positions within the hospitality industry.

Operational research in seven decades

This paper is an account and reflection on the author’s engagement with operational research (OR) starting in the 1960s with work in the glass industry coinciding with a PhD at Lancaster and a first encounter with the professional membership debate. The 1970s included a brief encounter with stochastic programming, soft OR which recurred throughout the decades, and the start of research into strategy support. The latter continued in the 80s and beyond and work on data envelopment analysis (DEA) began. In the 1990s, a strong DEA team was built at Warwick, and the author led the development of the OR Society’s fellowship scheme. In the 2000s a group met regularly at Warwick focussing on strategic development and leading to a book on strategy support and editing of the European Journal of Operational Research (EJOR) began. In the 2010s editing continued and work began on the contribution of the founders of OR to soft OR and practice. Editing wound down in the 2020s and the founders paper was published in the journal Operations Research.