Search Results (7)

Additive manufacturing (AM) is revolutionizing industrial production by enabling the fabrication of complex, customized components with reduced material waste. However, the scheduling of AM machines presents significant challenges in terms of optimizing both time-related performance and energy consumption. This paper introduces a novel multi-objective mixed-integer linear programming (MILP) model for scheduling AM machines with the dual objectives of minimizing makespan and energy consumption. We address the single-machine environment with detailed mathematical formulation that accounts for machine-specific parameters such as power consumption rates during different operational states, including printing, setup, and idle modes. Additionally, we consider part-specific characteristics including height, area requirements, and volume, ensuring practical feasibility constraints are met. The proposed model is validated using a comprehensive set of test problems, with optimal solutions reported for small to medium-sized instances. For larger problem instances, where computational complexity prevents finding optimal solutions within reasonable time limits, we report the best solutions obtained under specified time constraints. Computational experiments demonstrate that our approach effectively balances the trade-off between makespan and energy consumption, providing valuable insights for production planning in AM facilities. The results indicate potential energy savings of up to 18% compared to makespan-only optimization approaches, with minimal impact on overall completion times. Full article

Industry 4.0 integrates the intelligent networking of machines and processes through advanced information and communication technologies (ICTs). Despite advancements, small mechanical manufacturing enterprises face significant challenges transitioning to ICT-supported Industry 4.0 models due to a lack of technical expertise and infrastructure. These enterprises commonly encounter variable production volumes, differing priorities in customer orders, and diverse production capacities across low-, medium-, and high-level outputs. Frequent issues with machine health, glitches, and major breakdowns further complicate optimizing production scheduling. This paper presents a novel production management approach that harnesses bio-inspired methods alongside Internet of Things (IoT) technology to address these challenges. This comprehensive approach integrates the real-time monitoring and intelligent production order distribution, leveraging advanced LoRa wireless communication technology. The system ensures efficient and concurrent data acquisition from multiple sensors, facilitating accurate and prompt capture, transmission, and storage of machine status data. The experimental results demonstrate significant improvements in data collection time and system responsiveness, enabling the timely detection and resolution of machine failures. Additionally, an enhanced genetic algorithm dynamically allocates tasks based on machine status, effectively reducing production completion time and machine idle time. Case studies in a screw manufacturing facility validate the practical applicability and effectiveness of the proposed system. The seamless integration of the scheduling algorithm with the real-time monitoring subsystem ensures a coordinated and efficient production process, ultimately enhancing productivity and resource utilization. The proposed system’s robustness and efficiency highlight its potential to revolutionize production management in small-scale manufacturing settings. Full article

The regeneration and utilization of idle, old industrial buildings in urban areas has become a focus of urban development, owing to urban renewal and industrial structural adjustment. At the same time, the increasing demand for sports space has highlighted the insufficient supply of sports facilities in cities. To solve this dilemma, the transformation of old industrial buildings into sports venues has become another mode of recycling and reuse in recent years. Due to the many specialties, complex contents, and numerous influencing factors involved in the transformation process, the suitability of these buildings is uncertain. To ensure the suitability of the transformation project, the theory of old industrial buildings recycling and sports building design specifications was used. An index system was established for the evaluating the suitability of transforming old industrial buildings into stadiums, which included five first-level and twenty second-level indices. Based on the matter–element extension theory, a suitability evaluation model was constructed to transform old industrial buildings into sports venues. The correlation function of each evaluation index was calculated, and the index weight was determined using the entropy weight method to obtain the suitability grade of the renovation project, which was verified by the renovation project case. The research shows that the suitability level of the renovation project is level II, which is consistent with the actual situation, indicating that the evaluation model—based on entropy weight method and matter–element extension method—for the transformation of old industrial buildings and stadiums has high reliability. Full article

This study investigates the sustainable values of cafes established using idle industrial facilities that are a part of the cultural heritage of South Korea in terms of the characteristics of the architectural space and consumers’ space utilization. Twenty regenerative cafes in five regions were selected, and five of them were analyzed by comparing their characteristics with those of the conventional cafes. Unlike conventional cafes, regenerative cafes have architectural spaces that seem to be non-everyday and elicit a feeling of the passage of time. Users utilized these cafes as spaces for activities and experiences for long periods compared to conventional cafes. Consequently, regenerative cafes were found to contain sustainable values as complex networking spaces, as cultural heritage that can be experienced and as independent tourist destinations. Regenerative cafes have become unique differentiated architectural spaces utilized by several users. Full article

As the industrial structure rapidly changed, the buildings and facilities at the helm of the previous industrialization era lost their original functions and became idle. These spaces contain elements of local history, culture, and time and provide the basis for this study. Therefore, it focuses on the role of a city’s sustainable media if they are converted to fit the city’s social and local context. In this study, we examine sustainable regeneration by adopting the methodology of the “new directions in planning theory” method, which means a contradictory approach to the sustainable values of long-standing industrial heritages from both physical and cognitive perspectives. We argue that its physical appearance, landscaping, and tectonic relation, composed of a specific spectrum of time accumulation, help people experience a sense of collective memory. In this way, a sense of time and place are embedded in materiality and are important to consider when moving toward urban sustainability. Our findings have implications for a new perspective on concrete regeneration strategies. Full article

Abandoned industrial facilities have become a nuisance in cities because the needs of society members are continuously changing. Idle industrial facilities might be considered to be merely abandoned and empty spaces, but they are in reality historic sites that illustrate the period of industrialization in the region. They are valuable because they serve to accumulate memories from the past. Recently, with the need for urban regeneration, there have been various discussions on converting the abandoned industrial facilities into cultural art spaces. They are intended to promote the sustainability of communities and cities by vitalizing the area. Considering the social dimensions of urban regeneration, it is necessary to render such a creative space as a ‘Third Place’ to promote the city’s sustainability. Converted industrial facilities, through the medium of ‘Voluntary Arts Activities,’ have many elements that are suitable for the needs of a creative space, and even for a ‘Third Place’. As opposed to the private sector, it is seen that when the public sector regenerates these facilities, they approach this issue in order to lower the cultural arts barrier. The public sector, which is a government-centered first sector, conducts regeneration projects based on the ‘Democratization of Culture’ perspective. However, in order to promote participation in the third sector, which is a community-based, non-profit sector that actually uses the space, it is important to approach the issue from the ‘Cultural Democracy’ perspective. Focusing on this aspect, this study aims to examine cases of public sector-led converted cultural arts spaces by ‘Voluntary Arts Activities’ in France and South Korea, namely ‘Le Centquatre-Paris,’ the ‘Oil Tank Culture Park,’ and the ‘West Seoul Arts Center for Learning’. This will allow us to contemplate the possibility of sustainable spaces, individuals, communities and cities. Full article

Diesel powered tractors are used to shuttle cargo trailers from point to point within the confines of a port facility, terminal or warehouse yard. Such operations are similar to those in ground support applications at airports and in industrial warehouses with lift trucks, in that the vehicles are used as tools to move goods in a semi-regular pattern. Southern California Edison Company (SCE) and the Electric Power Research Institute (EPRI) have partnered to help electrify vehicle operations in both of those venues with great success and see good prospects for the same at port operations. However, current port operations might require large investments in infrastructure and operational changes to implement electric drive all at once. To help demonstrate the benefits of electric drive without requiring large-scale changes, a plug-in hybrid electric vehicle (PHEV) yard tractor design was proposed by EPRI and member utilities as a means to reduce operational emissions and diesel fuel use. Four member utility companies with large port customers in their service area (SCE, Southern Company, CenterPoint Energy, and New York Power Authority) agreed to work with EPRI to study the benefits and impacts of a PHEV yard tractor. In 2007 the Electric Power Research Institute (EPRI) contracted US Hybrid Corporation (USH) to design and construct a unique PHEV yard tractor. SCE agreed to test and evaluate the PHEV yard tractor for EPRI. To properly evaluate the benefits realized by the yard tractor in comparison to unmodified conventional yard tractors as well as other alternative fueled tractors, SCE had to test the tractor in controlled conditions with realistic loads in addition to field testing. SCE developed test procedures for controlled testing and for field evaluation. The field testing was conducted in four ports across the United States, each with different operating conditions and climate: Long Beach, California; Houston, Texas; Savannah, Georgia; and New York City. SCE designed a test procedure that simulates an accelerated duty cycle of cargo operations. The accelerated duty cycle has multiple starts and stops and little idle time. SCE measured the idling fuel consumption separately so it can be inserted to match the duty cycle of any particular port. The test cycle was performed with the vehicle both unloaded and loaded to profile the effects of load on system efficiencies. SCE also tested the battery and charger performance of the PHEV, and as a comparison, tested an unmodified yard tractor. In the accelerated testing, SCE found the PHEV fuel savings were as high as 60% (on a per-cycle basis) when compared to a stock diesel Kalmar tractor, and up to 35% fuel savings versus operating the PHEV tractor as a hybrid (i.e, not charging it), In charge sustaining operation, the fuel savings are as high as 40% compared to the stock vehicle. On a daily-operation basis, the projected fuel savings on a duty cycle similar to the SCE test cycle could be as low as 35% but as high as 60% with significant amounts of idling and low speed operation. The field test results show good fuel economy but are complicated by reliability issues that reduced the operational time of the prototype PHEV vehicle. Also, it was difficult to get fleet fuel use data. It was the intention in the project to compare the test vehicle’s results with the fleet average fuel use per unit time. These results will be discussed in the body of the paper. Port operators, in general, appreciated the engineoff mode’s reduced noise and exhaust. The US Hybrid prototype PHEV yard tractor has the potential to significantly reduce fuel consumption, as demonstrated in the SCE tests. Performance issues with the prototype prevented full duty in the field tests. Further testing, with a more reliable vehicle incorporating the key system improvements learned from this project, is worth pursuing to determine if the potential fuel savings can be fully realized in larger scale. Furthermore, the techniques and testing methods described can be used for other alternatively-fueled yard tractors. Full article