Linear Supply Research Articles

Cambuci Festival as an Attraction for Cultural Tourism From the Perspective of the Sustainable Supply Chain

Objective: To characterize the use of cambuci, a native Brazilian fruit, during the Festival in the village of Paranapiacaba, Santo André-SP, as a circular chain supply. Theoretical Framework: Supply chains are configured in linear or circular. Linear chain is an open system that ignores the extraction environment, resource yield, waste, assimilative capacity, and recycling. A circular chain is a closed system where the environment is part of the system, as it considers extraction, resource yield, waste, assimilative capacity and recycling. Gastronomic tourism was considered as a segment of cultural tourism. Method: A qualitative study was carried out through testimonies as a methodological approach proposed by Meksenas (2002). For analysis, testimonies from 2023-2013 were selected, from electronic addresses. The categorization of testimonies transcribed from the corpus allowed the thematic analysis according to Jovchelovitch and Bauer, (2002). Results and Discussion: The community works in the extraction of cambuci, in the elaboration of derivatives, in the organization of the event, in the commercialization, but there are no testimonies about the destination of waste. Thus, cambuci is an open-system linear chain supply with no mention of waste. Gastronomic tourism requires proper planning to mitigate impacts on the destination. Research Implications: Interviews coincided with the pandemic period. Originality/Value: Gastronomy fosters cultural tourism. The participation of the community in the collection, elaboration, and organization of the event made it possible to describe the trajectory of cambuci as a supply of an open system production chain due to the disposal of waste. The methodological approach of testimonies optimized the study during the pandemic.

Design of Nanosecond Pulse Laser Diode Array Driver Circuit for LiDAR

The pulse laser emission circuit plays a crucial role as the emission unit of time-of-flight (TOF) LiDAR. This paper proposes a nanosecond-level pulse laser diode array drive circuit for LiDAR, primarily aimed at addressing the issue of high-speed scanning drive for the laser diode array at the emission end of solid-state LiDAR. Based on the single pulse laser diode drive circuit, this paper innovatively designs a circuit that includes modules such as a boost circuit, linear power supply, high-speed gate driver, GaN field-effect transistor, and pulse narrowing circuit, realizing an 8-channel laser diode array drive circuit. This circuit can achieve a pulse laser array drive with a single channel operating frequency of greater than 100 kHz, an output pulse width of less than 5 ns, a peak power greater than 75 W, and a channel switching time that does not exceed 1 μs. A field programmable gate array (FPGA) is used to control the operation of this circuit and perform a series of performance tests. Experimental results show that this circuit has a high repetition rate, large output power, a narrow pulse width, and fast switching speeds, making it highly suitable for use in the optical emission module of solid-state LiDAR.

An Integrated Circular Supply Chain Framework to Enhance Malaysian Business Performance

Businesses rely on supply chain management to suit the needs of global and multigenerational consumers. However, the current linear manufacturing and distribution supply chain strategy has been regarded as the source of dangerous waste generation, environmental deterioration, and the global warming phenomenon. In mitigating this issue, circular supply chain management, a practical integration model, is seen as the solution as it helps to reduce material flows and supply chain waste. Unfortunately, the fundamental mechanisms that can support its effective execution have not been comprehensively examined, hindering its complete incorporation into company strategy. Thus, to overcome this knowledge gap and improve organizational understanding, this study uses the systematic reviews and meta-analyses extension for scoping reviews (PRISMA-ScR) procedure to investigate the characteristics, enablers, and barriers of circular supply chain management. The study found five interconnected key structures: government, industry stakeholders, corporate management, end users, and financial institutions, all of which play important roles in the successful implementation of a circular supply chain strategy. As a result, close collaboration across the five identified stakeholders is essential to enable successful implementation. This study's objective is to the United Nations Sustainable Development Goals (SDGs) 8, 9, and 12, which aim to promote peace and prosperity for people and the planet both now and in the future.

A semi-analytical approach for thermoelastic wave propagation in infinite solids subject to linear heat supply using two-phase lag theory

A semi-analytical approach for thermoelastic wave propagation in infinite solids subject to linear heat supply using two-phase lag theory

Circular supply chains as complex adaptive ecosystems: A simulation-based approach

Circular Supply Chains (CSCs) are self-sustained ecosystems designed to pursue Circular Economy principles. Compared to linear supply chains, they involve new classes of stakeholders performing circular activities and multiple resource streams (e.g. virgin materials, by-products, end-of-life products, waste) moving forward and back the original and different supply chains. Therefore, CSCs are characterized by increasing complexity that call for proper coordination mechanisms. In this regard, we propose a theoretical framework, based on the theory of Complex Adaptive Systems, capturing the static and dynamic dimensions of CSC complexity which characterize the archetype of a CSC and then we develop a novel agent-based model to simulate the effect of competition and collaboration mechanisms on CSC performance across different CSC archetypes. The results of numerical simulations suggest which mechanism to adopt for the coordination of certain CSC archetypes: while competition is always detrimental, local collaboration is effective for CSCs with closed loop structures, and global collaboration is instead required in presence of open and hybrid loop structures.

Design of a Portable Emergency DC Power Supply

Abstract In recent years, wireless or handheld devices have become increasingly widely used, especially in areas such as environmental monitoring and the Internet of Things. However, due to environmental conditions, they cannot rely on the power grid to provide electricity, and energy supply has become a key issue that restricts the deployment and operation of such devices. This article introduces the method and principle of applying a microcontroller control system to a portable emergency DC power supply, and proposes a method for a portable emergency DC power supply with adjustable and stable output. The output voltage can be adjusted in steps of 0.1-15V. This adjustable portable emergency DC power supply not only has the advantages of small volume and low loss of switch mode power supply, but also has the advantages of small output voltage ripple and good output characteristics of linear power supply. It has certain research significance and practical value.

Representative days and hours with piecewise linear transitions for power system planning

Electric demand and renewable power are highly variable, and the solution of a planning model relies on capturing this variability. This paper proposes a hybrid multi-area method that effectively captures both the intraday and interday chronology of real data considering extreme values, using a limited number of representative days, and time points within each day. An optimization-based representative extraction method is proposed to improve intraday chronology capturing. It ensures higher precision in preserving data chronology and extreme values than hierarchical clustering methods. The proposed method is based on a piecewise linear demand and supply representation, which reduces approximation errors compared to the traditional piecewise constant formulation. Additionally, sequentially linked day blocks with identical representatives, created through a mapping process, are employed for interday chronology capturing. To evaluate the efficiency of the proposed method, a comprehensive expansion co-planning model is developed, including transmission lines, energy storage systems, and wind farms.

Complex Network-Based Resilience Assessment of the Integrated Circuit Industry Chain

With the improvement of social production efficiency and the enhancement of the supply chain system, the traditional linear supply chain model is gradually evolving into a more complex and dynamic industrial chain network. This article uses complex network theory combined with the basic attributes of the industrial chain and supply chain to conduct a comprehensive and in-depth analysis of the integrated circuit industry chain. Firstly, a cooperative network model of the integrated circuit industry chain in Shaanxi Province is established based on the supply chain relationships of enterprises. Secondly, the study analyzes the basic characteristics of the collaborative network model. Thirdly, this study explores the efficiency, resilience, and innovation capacity of industrial chains using a novel set of indexes: the industry chain efficiency index (ICEI), the industry chain resilience index (ICRI), and the industry chain innovation capability index (ICICI). By employing principal component analysis (PCA), the study provides a comprehensive evaluation of industrial chain performance. The findings reveal that the ICEI highlights the critical importance of average path length and network density, showing that shorter paths and higher density are associated with greater efficiency. The ICRI emphasizes the roles of average degree and standard deviation, indicating that higher connectivity and lower variability contribute to resilience. The ICICI identifies the clustering coefficient and network density as key factors, suggesting that tight-knit networks foster innovation. These results offer significant insights into the dynamics of industrial chain collaboration and provide practical recommendations for enhancing supply chain management. Finally, the effectiveness of the proposed method is demonstrated through a case study. The results of the case study indicate the following: (1) Key Enterprises’ Identification: The analysis identified key enterprises like Samsung Semiconductor and HT-tech with the highest betweenness centrality, highlighting their crucial intermediary roles within the network; (2) Efficiency and Innovation Assessment: Compared with foreign-owned and other immigrant businesses, local businesses generally perform below average in terms of efficiency and resilience, indicating that there is room for improvement in technology adoption and innovation capabilities.

A dynamic model of resource extraction and intensity of competition

AbstractThis paper represents a significant extension of the traditional Cournot extraction game, by introducing the linear supply function strategy space in a novel, dynamic way. A variety of asymmetric cases are considered, including the new firm‐specific competitive strategies. The results highlight the importance of competition in accelerating the supply of critical minerals, which is vital to mitigate climate change, but also present a new sustainability challenge.

A five-phase combinatorial approach for solving a fuzzy linear programming supply chain production planning problem

A five-phase combinatorial approach for solving a fuzzy linear programming supply chain production planning problem

A Study on Enhancing Sustainability in Circular Supply Chains through Green Innovations

Redefining product and service lifecycles with eco-friendly and sustainable processes, circular supply chains are green breakthroughs. Minimising waste, environmental effect, and resource efficiency are its goals. In a circular supply chain, green innovations can include product design that facilitates recycling or reuse, process improvements that reduce energy consumption and emissions, logistics solutions that optimise transportation for lower carbon footprints, and service innovations that promote sustainability. These green ideas improve supply chain efficiency and competitiveness while helping the environment. Businesses may reconcile economic growth and environmental stewardship by rethinking and rebuilding linear supply models into circular and sustainable ones, paving the way for a more sustainable future. This study examines how green innovations affect circular supply chains in Andhra Pradesh's durable goods industry. It analyses how product, process, logistical, and service green innovation improves supply chain efficiency. The quantitative research uses structured surveys to obtain data from 150 industry professionals and customers. Convenience sampling was used to acquire varied supply chain performance metrics responses. SPSS is used for rigorous regression analysis in the study. This method lets you study how green innovation affects circular supply chain performance. All green innovations improve supply chain efficiency, but green service innovation has the greatest benefit. This research provides strong evidence for green innovations in durable goods industry circular supply networks. The study emphasises ecologically friendly product creation, logistics, service delivery, and process management.

Circular supply chains theoretical gaps and practical barriers: A model to support approaching firms in the era of industry 4.0

Unlike linear supply chains, Circular Supply Chains (CSCs) require return flows able to capture additional value and involving different stakeholders. The successful interaction of Circular Economy and Industry 4.0 (I4.0) towards a circular, efficient, and competitive transition of current supply chains is unveiled by both current state of theory and practice. Notwithstanding literature’s multiple attempts to flank supply chains in this complex shift, the several theoretical frameworks proposed by academics are still not fully capable of bridging linear supply chains to their transitions towards circularity due to a lack of systemic, company-specific, and practical approaches. In addition, practical impediments, risks and treats hindering CSCs development are still under-investigated and, therefore, further research is required in this domain. To address these gaps, this paper aims to develop and propose a model able to support companies in approaching the transition towards CSCs, also embedding guidelines and recommendations in the different steps of this path. The model has been conceptualized based on five I4.0-driven CSCs categories recently proposed through a systematization of the knowledge extant in literature (I4.0 enabling technologies, performance tools and indicators, challenges and barriers, business models and strategies, best practices) and on a gap analysis performed in literature to unveil theoretical gaps and practical barriers in the CSC domain. Finally, the model has been refined and validated by ten selected academic experts through an online asynchronous survey, leading to the detection of seven recurrent practical barriers (lack of tax policies and incentives, weak environmental laws and regulations, limited financial resources and support, high investments and implementation costs, lack of coordination and collaboration among the SC members, lack of technological resources and infrastructures, lack of compatibility and integration of technical platforms) as the most critical in the CSC transition. The model, structured in four main phases (conceptualization, design, implementation and measurement) and grounded on the five categories derived from the literature, addresses each of the steps of the CSC transition according to circular strategies and optimal digital technologies. Managerial implications emerge from the systematization and categorization of methods, approaches and warnings operated in the model proposed. The model turns to be capable of enhancing the realization of the entire CSC process in a digital context, acting against the CSC theoretical gaps and practical barriers detected in the gap analysis conducted in this research.

Inquiry-based learning: a student-centric approach to engaging students in sustainability and life cycle thinking

The increasingly volatile, complex, ambiguous and uncertain (VUCA) nature of the world has been recognized by business leaders and others. Experiential learning offers multiple opportunities for students to actively engage in their learning and spark their interest and motivation to address complex societal problems. Inquiry-Based Learning (IBL) is a student-centric experiential learning method. This paper describes a proposed application of IBL based on a past incident, the collapse of a garment factory in 2013. In this proposed application, students will formulate and refine an inquiry question, and collect and analyze information focusing on the role, responsibilities and decisions made by the various stakeholders. Students will also reflect on the life cycle of a consumer product and the implications of a linear economy and supply chain perspective and their social dimensions. This analysis will be guided by the five phases of IBL. Such an approach is suitable for all types of engineering disciplines and levels.

Taking firms' margin targets seriously in a model of competition in supply functions

AbstractThis article deals with the integration of industry‐level markup targets into oligopoly theory. It proposes a behavioral competition model in which firms use the average cost‐plus price to determine their supplies. Specifically, firms are assumed to increase (resp., decrease) their supplies as the market price rises over (resp., falls below) this reference price. The equilibrium market outcome lies between those corresponding to Bertrand and Cournot competition. It depends on the industry's margin target, which determines the slope of firms' supply functions. The more significant the markup target is, the lower are the firms' equilibrium supplies at any price level and the higher is the equilibrium market price. An industry‐wide commitment to targeting a markup thus reduces competition in equilibrium. The reduction in competition is more pronounced than when firms commit to linear supply functions.

Development of the LNG market in the European Union in the context of war Russia-Ukraine

According to the latest data from the International Energy Agency, global LNG trade increased by almost 6% year-on-year between January and August 2022. It was dominated by rising demand for the commodity in the European Union. This was driven by sharp cuts in linear gas supplies from Russia, which are linked to the EU's stance of abandoning Russian supplies due to Russia's war with Ukraine, and the subsequent imposition of sanctions by the European Union on Russia. In January-August 2022 alone, LNG imports into the EU increased by as much as 65% (43 bcm) compared to the same period in 2021. Such a significant increase in the supply of LNG to European countries was also made possible by a decline in demand for LNG in the Asia-Pacific region, due to the mild winter, high price levels, and disruptions related to Covid-19 and the aftermath of lockdowns in China. The cut-off of gas supplies from Russia has shown that the LNG market in the EU can play an important role in both the region's energy security and energy transition. In fact, the European Commission treats gas as a blue fuel, much less carbon-intensive than other conventional energy sources such as coal or oil. An additional advantage of LNG is the possibility to transport this fuel from various locations, rapid change of supply directions, and the more extensive possibilities for its storage. For an EU struggling for a stable supply of raw material, pursuing the Green Deal and carrying out an energy transition, this is an option that could become a strategic element in the long term. The research objective of this article is to investigate and analyze how the share of LNG in the EU's energy mix has changed and in what direction it is affecting EU energy security after Russia's aggression in Ukraine.

Development of linear power operational amplifier power supply with pre-regulated voltage controller for TPS correction magnets

The Taiwan Photon Source (TPS) is a renowned 3 GeV synchrotron accelerator light source. Over the past decade of successful operation, it has demonstrated outstanding performance, notably in average beam trip downtime, meeting international standards. A continuous regimen of scheduled equipment upgrades has been maintained across all subsystems to ensure ongoing improvement and the preservation of an optimal research facility environment. The central focus of this study revolves around the design and realization of a TPS correction magnet power supply employing Linear Power Operational Amplifiers (LPOA) in conjunction with a pre-regulated voltage controller. The power source predominantly features APEX Corporation's PA05 LPOA, characterized by bipolar output, high internal power dissipation, and wide bandwidth. Additionally, a DC Current Transducer (DCCT) was employed as the current feedback element, integrated with the pre-regulator voltage controller to form a closed-loop current modulation circuit, providing the variable voltage required by the LPOA. Through these measures, we have successfully developed an LPOA power supply unit equipped with a pre-regulated voltage controller for TPS correction magnets. The prototype device boasts a maximum output current of ±10 A, operating at 24 V. Validation through control loop design has led to rapid and stable output current performance. The output current ripple is maintained within 100 μA, with a rise time of 75 μs during step response. During frequency response testing utilizing a 0.1 V disturbance signal, the gain margin resides within -3 dB at an 11.2 kHz bandwidth and the phase margin within -45∘ at a 5.1 kHz range. Long-term output current stability is sustained within ten ppm. Finally, a hardware prototype circuit has been constructed in the power supply laboratory, featuring a ±24 V input voltage and ±10 A output current, achieving a maximum rated power of 240 W.

Circular economy in winter road maintenance: Analysis of contract models for deploying a closed-loop supply chain

In winter road maintenance, abrasives are spread on roads to ensure user safety. These abrasives must be swept in the spring and often end up in landfills. To reduce landfilling and the consumption of non-renewable resources, previous work has demonstrated the potential of reusing collected street sweepings for the production of abrasives. However, the current contractual approach of the linear supply chain requires revision to enable the sharing of financial gains between the road authority and the service provider to achieve a win–win situation, primarily considering the uncertainty in the quantity of abrasives spread, which directly impacts the service provider’s profit. This study proposes two closed-loop supply chain structures and analyzes three contract models. Results from a case study in a highway context in Quebec, Canada reveal that transitioning from a linear supply chain to a closed-loop supply chain generates an average systemic financial gain of 9%. Furthermore, a sensitivity analysis on the average quantity of abrasive spread demonstrates that when the road authority buys back reusable sweepings from the service provider at market value, it enables the sharing of a portion of the gain. Consequently, compared to a linear approach, adopting circular economy strategies in the winter road maintenance supply chain mitigates the potential profit loss of the service provider caused by uncertainty.

Competitive Strategy to Collaborative Strategy: Tale of organic food firms from an emerging economy

The socioeconomic changes in emerging economies shifted the market power from suppliers to customers. This compelled the firms to adopt a customer-centric approach, i.e., a differentiation strategy, to attain competitive advantage. The effective implementation of a differentiation strategy necessitates the adoption of value-chain thinking. The study aims to understand the transformation of linear supply chains to networked value chains as a firm moves toward differentiation. This study adopts a qualitative approach to understand the value chain of two Indian organic food firms, as organic foods are highly differentiated and customer-valued. Using the theoretical lens of transaction cost theory, evolution theory, and systems theory, this study attempts to highlight the business environment of organic foods. The study finds that as the stakeholder dependence is higher in the organic food sector, so does the need for cooperation and collaboration, thereby leading to network structure.

Understanding the relationship between institutional pressures, supply chain integration and the adoption of circular economy practices

This paper explores the role of institutional pressures and supply chain integration in the adoption of Circular Economy practices. Using a Delphi-like approach and leveraging on a panel of 30 experts in the field of Circular Economy, this study aims to gain additional insights into how coercive, normative, and mimetic pressures can drive the implementation of circular supply chains. The findings reveal a hierarchy of institutional pressures, with coercive market and regulatory pressures having a greater impact compared to normative and mimetic pressures. Additionally, the study identifies various responses to these pressures, illustrating different trajectories towards the implementation of Circular Economy practices. Furthermore, the research investigates the role of supply chain integration. Generally, a higher level of supply chain integration can amplify the effect of institutional pressures, promoting the adoption of incremental Circular Economy practices. However, it is noteworthy to mention that supply chain integration may also hinder the adoption of more radical Circular Economy approaches, favouring the retention of linear supply chains.

Shift or Pivot? Market Entry and Exit With Linear Supply and Demand Curves

Textbooks commonly misrepresent the effects of market entry and exit by consumers and producers as parallel shifts of linear market demand and supply curves. Such portrayals are inconsistent with the underlying premise that a market-level curve is the horizontal summation of individual-level curves. A more accurate depiction is a pivot: entry flattens (and exit steepens) a market-level curve. Reconceiving the effects of entry and exit as pivoting, rather than shifting, the curve has important implications for own-price elasticities, consumer surplus, producer surplus, the incidence of taxation, and the competitive market adjustment to a long run equilibrium. JEL codes: A22, B40, D01