920 resultados para Markov chains
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Date of Acceptance: 16/10/2015
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Service supply chain (SSC) has attracted more and more attention from academia and industry. Although there exists extensive product-based supply chain management models and methods, they are not applicable to the SSC as the differences between service and product. Besides, the existing supply chain management models and methods possess some common deficiencies. Because of the above reasons, this paper develops a novel value-oriented model for the management of SSC using the modeling methods of E3-value and Use Case Maps (UCMs). This model can not only resolve the problems of applicability and effectiveness of the existing supply chain management models and methods, but also answer the questions of ‘why the management model is this?’ and ‘how to quantify the potential profitability of the supply chains?’. Meanwhile, the service business processes of SSC system can be established using its logic procedure. In addition, the model can also determine the value and benefits distribution of the entire service value chain and optimize the operations management performance of the service supply.
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This research paper focuses on the self-declared initiatives of the four largest chocolate companies to tackle social problems within the context of establishing a sustainable supply chain. After the literature review of sustainability, supply chain management, and cocoa farming, this paper gives an assessment of the extant practices of the chocolatiers and makes a comparative analysis based on Corporate Social Responsibility (CSR) and Sustainability Reports. This paper uses a case study approach based on secondary-data. A roadmap and benchmarking of social sustainability initiatives were conducted for the supply chain management activities of the world's four largest chocolatiers. This paper analyses the extant sustainability practices of the chocolatiers and offers a model framework for comparison of the measures taken. This paper is based on self-declared secondary data. There is a chance that some practices were not documented by the case companies; or that companies claim what they don't actually do. This paper provides a framework for agricultural businesses to compare their sustainability efforts and improve the performance of their supply chains. Originality and value of this research reside in terms of both literature and methodology. The framework for analysing the social sustainability aspects of agricultural supply chains is original and gives an up-to-date view of sustainability practices. The use of secondary data to compare self-declared initiatives is also a novel approach to business sustainability research.
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Within 10 years, there could be a severe global shortage in the supply of cocoa, according to industry practitioners and other experts. Due to global population growth and the emergence of a growing global middle class, by 2025 the cocoa crop would need to increase by nearly 50 per cent to keep up with projected demand. A potential shortage of supply is a direct threat to the business model of lead firms – including cocoa grinders and processors, chocolate confectioners, and retail distributors. But these international firms – the ones that will suffer the most if there is a shortage of cocoa supply – are helping create the market failure that is stifling sustainability. Functioning as a two-tiered consolidated oligopoly with a combined market share of approximately 89%, these firms enjoy the largest portion of value capture in the cocoa-chocolate global value chain (GVC). The smallholder cocoa producers, conversely, are trapped in low value-add segments of the GVC. In fact, most smallholder farmers survive on less than $1.00 per day per capita, on average in many cocoa exporting countries. In Ghana - the second largest producer of cocoa in the world - the government has accomplished little to help these smallholders upgrade and make cocoa an attractive sector for the next generation to inherit. The result – both in Ghana and around the world – is a lack of sustainability of the supply of cocoa. Demand is already beginning to outstrip supply. As a result of these underlying circumstances, the United States Agency for International Development (USAID) has posed the following policy question: "Under what conditions could USAID, as a development agency, support and enhance potential public-private partnerships in order to improve the bargaining power (and financial wherewithal) of smallholder organizations and farmers in the context of the global value chain for cocoa in Ghana?"
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This article examines the structure and health implications of two industries, chicken and tomatoes, that play prominent roles in US food and agricultural competitiveness. Both industries have become more concentrated over time, with powerful "lead firms" driving geographical, technological, and marketing changes. Overall, a processed food revolution has taken place in agricultural products that transforms the types of food and dietary options available to consumers. The nature of contemporary food and agricultural value chains affects the strategies and policies that can be effectively employed to address major health goals such as improved nutrition, food safety, and food security.
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The report is based on a desk-based review, drawing upon existing studies of global supply chains (GSCs) to examine their impacts and implications for the development of domestic firms, their contribution to productive transformation and structural change and their impacts on the quantity and quality of jobs in the LAC region. It situates the expansion of GSCs in the region within an analytical framework that recognizes both the economic and social upgrading dimensions and the impacts on firms and workers. Special attention is given to the mechanisms for governing the terms and conditions of engagement between firms and between firms and workers in GSCs, with the aim of identifying ways to jointly pursue the goals of raising competitiveness and of promoting productive employment and decent work.
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This research adds to a body of work exploring the role of Social Network Analysis (SNA) in the study of both relational and structural characteristics of supply chain networks. Two contrasting network cases (food enterprises and digital-based enterprises) are chosen in order to elicit structural differences in business networks subject to divergences in local embeddedness and the relative materiality of the goods and services produced. Our analysis and findings draw out differences in network structure as evidenced by metrics of network centralization and cohesion, the presence of components and other sub-groupings, and the position of central actors. We relate these structural features both to the nature of the networks and to the (qualitative) experiences of the actors themselves. We find, in particular, the role of customers as co-creators of knowledge (for the Food network), the central role of infrastructure and services (for the Digital network), the importance of ICT as a source of codified knowledge inputs, along with the continuing importance of geographical proximity for the development and transfer of tacit knowledge and for incremental learning.
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Rapid technological advances and liberal trade regimes permit functional reintegration of dispersed activities into new border-spanning business networks variously referred to as global value chains (GVCs). Given that the gains of a country from GVCs depend on the activities taking place in its jurisdiction and their linkages to global markets, this study starts by providing a descriptive overview of China’s economic structure and trade profile. The first two chapters of this paper demonstrate what significant role GVCs have played in China’s economic growth, evident in enhanced productivity, diversification, and sophistication of China’s exports, and how these economic benefits have propelled China’s emergence as the world’s manufacturing hub in the past two decades. However, benefits from GVC participation – in particular technological learning, knowledge building, and industrial upgrading – are not automatic. What strategies would help Chinese industries engage with GVCs in ways that are deemed sustainable in the long run? What challenges and related opportunities China would face throughout the implementation process? The last two chapters of this paper focus on implications of GVCs for China’s industrial policy and development. Chapter Three examines how China is reorienting its manufacturing sector toward the production of higher value-added goods and expanding its service sector, both domestically and internationally; while Chapter Four provides illustrative policy recommendations on dealing with the positive and negative outcomes triggered by GVCs, within China and beyond the country’s borders. To the end, this study also hopes to shed some light on the lessons and complexities that arise from GVC participation for other developing countries.
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The design of reverse logistics networks has now emerged as a major issue for manufacturers, not only in developed countries where legislation and societal pressures are strong, but also in developing countries where the adoption of reverse logistics practices may offer a competitive advantage. This paper presents a new model for partner selection for reverse logistic centres in green supply chains. The model offers three advantages. Firstly, it enables economic, environment, and social factors to be considered simultaneously. Secondly, by integrating fuzzy set theory and artificial immune optimization technology, it enables both quantitative and qualitative criteria to be considered simultaneously throughout the whole decision-making process. Thirdly, it extends the flat criteria structure for partner selection evaluation for reverse logistics centres to the more suitable hierarchy structure. The applicability of the model is demonstrated by means of an empirical application based on data from a Chinese electronic equipment and instruments manufacturing company.
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We study the nonequilibrium dynamics of the linear to zigzag structural phase transition exhibited by an ion chain confined in a trap with periodic boundary conditions. The transition is driven by reducing the transverse confinement at a finite quench rate, which can be accurately controlled. This results in the formation of zigzag domains oriented along different transverse planes. The twists between different domains can be stabilized by the topology of the trap and under laser cooling the system has a chance to relax to a helical chain with nonzero winding number. Molecular dynamics simulations are used to obtain a large sample of possible trajectories for different quench rates. The scaling of the average winding number with different quench rates is compared to the prediction of the Kibble-Zurek theory, and a good quantitative agreement is found.
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We numerically analyse the behavior of the full distribution of collective observables in quantum spin chains. While most of previous studies of quantum critical phenomena are limited to the first moments, here we demonstrate how quantum fluctuations at criticality lead to highly non-Gaussian distributions. Interestingly, we show that the distributions for different system sizes collapse on thesame curve after scaling for a wide range of transitions: first and second order quantum transitions and transitions of the Berezinskii–Kosterlitz–Thouless type. We propose and analyse the feasibility of an experimental reconstruction of the distribution using light–matter interfaces for atoms in optical lattices or in optical resonators.