1,913 research outputs found

    A general framework for handling commitment in online throughput maximization

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    We study a fundamental online job admission problem where jobs with deadlines arrive online over time at their release dates, and the task is to determine a preemptive single-server schedule which maximizes the number of jobs that complete on time. To circumvent known impossibility results, we make a standard slackness assumption by which the feasible time window for scheduling a job is at least 1+ε1+\varepsilon times its processing time, for some ε>0\varepsilon>0. We quantify the impact that different provider commitment requirements have on the performance of online algorithms. Our main contribution is one universal algorithmic framework for online job admission both with and without commitments. Without commitment, our algorithm with a competitive ratio of O(1/ε)O(1/\varepsilon) is the best possible (deterministic) for this problem. For commitment models, we give the first non-trivial performance bounds. If the commitment decisions must be made before a job's slack becomes less than a δ\delta-fraction of its size, we prove a competitive ratio of O(ε/((ε−δ)δ2))O(\varepsilon/((\varepsilon-\delta)\delta^2)), for 0<δ<ε0<\delta<\varepsilon. When a provider must commit upon starting a job, our bound is O(1/ε2)O(1/\varepsilon^2). Finally, we observe that for scheduling with commitment the restriction to the `unweighted' throughput model is essential; if jobs have individual weights, we rule out competitive deterministic algorithms

    Optimally Handling Commitment Issues in Online Throughput Maximization

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    A Lightweight, Non-intrusive Approach for Orchestrating Autonomously-managed Network Elements

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    Software-Defined Networking enables the centralized orchestration of data traffic within a network. However, proposed solutions require a high degree of architectural penetration. The present study targets the orchestration of network elements that do not wish to yield much of their internal operations to an external controller. Backpressure routing principles are used for deriving flow routing rules that optimally stabilize a network, while maximizing its throughput. The elements can then accept in full, partially or reject the proposed routing rule-set. The proposed scheme requires minimal, relatively infrequent interaction with a controller, limiting its imposed workload, promoting scalability. The proposed scheme exhibits attracting network performance gains, as demonstrated by extensive simulations and proven via mathematical analysis.Comment: 6 pages 7, figures, IEEE ISCC'1

    Sustainable Living Factories for Next Generation Manufacturing

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    To be profitable and to generate sustainable value for all stakeholders, next generation manufacturers must develop capabilities to rapidly and economically respond to changing market needs while at the same time minimizing adverse impacts on the environment and benefiting society. 6R-based (Reduce, Reuse, Recycle, Recover, Redesign and Remanufacturing) sustainable manufacturing practices enable closed-loop and multi-life cycle material flow; they facilitate producing more sustainable products using manufacturing processes and systems that are more sustainable. Reconfigurable Manufacturing Systems (RMS) and its characteristics of scalability, convertibility, diagnosability, customization, modularity and integrability have emerged as a basis for living factories for next generation manufacturing that can significantly enhance the system sustainability by quickly adjusting system configuration and production processes to meet the market needs, and maintain the system values for generations of products. This paper examines the significance of developing such next generation manufacturing systems as the basis for futuristic sustainable living factories by adapting, integrating and implementing the RMS characteristics with the principles of sustainable manufacturing to achieve value creation for all stakeholders

    E-Fulfillment and Multi-Channel Distribution – A Review

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    This review addresses the specific supply chain management issues of Internet fulfillment in a multi-channel environment. It provides a systematic overview of managerial planning tasks and reviews corresponding quantitative models. In this way, we aim to enhance the understanding of multi-channel e-fulfillment and to identify gaps between relevant managerial issues and academic literature, thereby indicating directions for future research. One of the recurrent patterns in today’s e-commerce operations is the combination of ‘bricks-and-clicks’, the integration of e-fulfillment into a portfolio of multiple alternative distribution channels. From a supply chain management perspective, multi-channel distribution provides opportunities for serving different customer segments, creating synergies, and exploiting economies of scale. However, in order to successfully exploit these opportunities companies need to master novel challenges. In particular, the design of a multi-channel distribution system requires a constant trade-off between process integration and separation across multiple channels. In addition, sales and operations decisions are ever more tightly intertwined as delivery and after-sales services are becoming key components of the product offering.Distribution;E-fulfillment;Literature Review;Online Retailing

    A value-based corporate leadership in the areas of conflit between profit maximization and business ethics

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    A corporate leadership aims at maximizing profits in order to secure long-term existence. The concept of a value-based corporate leadership includes a concept of increasing value, which refers to the enhancement of shareholder value. Leadership behavior and value-based leadership is primarily based on the profit interests of a firm’s shareholders. Investments in the firm are mainly focused on increasing shareholder value. This monistic focus on maximizing profits contrasts with economic ethical guidelines, which evolves in the context of sustainable responsibility and business ethics, since these two concepts diverge due to their different objectives. To practice ethics in the capital market, it requires renunciation and long-term rethinking. Economize cost-effectively and gaining profits is the first objective of any firm. However, it is an inherent ambivalence of a mutual condition of the economy and morale, which is reflected in the market economy and in the economic middle class. Nowadays, more and more firms get involved with regard to social responsibility and corporate leadership. Monetary and material donations for public facilities are provided, volunteering or free services are offered. This selfevident, social engagement is receiving increased appeal and hearing in public. As a result, firms not only demonstrate their social responsibility, but at the same time improve their image. But is this sufficient to withstand a value-based corporate leadership in the areas of conflict between profit maximization and business ethics? A value-based corporate leadership has to succeed in connecting the responsibility of the firm and its entrepreneurial and ethical perspectives, so that it serves in a supportive way and pursues a common goal. This attitude is justified in arguing that firms are not only necessarily dependent on operating profitably, but also on gaining social acceptance, which legitimize its economic actions. A successful corporate leadership has to go hand in hand with the concepts of profit maximization and the moral commitment of a firm. Moral commitment strengthens the foundation of legitimacy of entrepreneurial actions. The later presented Holistic Value Driver Scorecard is the main content of this work and the author´s contribution to science. The aim of this work is to provide firms a managerial tool to improve their business processes and detect value drivers as well as destroyers

    ARPA Whitepaper

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    We propose a secure computation solution for blockchain networks. The correctness of computation is verifiable even under malicious majority condition using information-theoretic Message Authentication Code (MAC), and the privacy is preserved using Secret-Sharing. With state-of-the-art multiparty computation protocol and a layer2 solution, our privacy-preserving computation guarantees data security on blockchain, cryptographically, while reducing the heavy-lifting computation job to a few nodes. This breakthrough has several implications on the future of decentralized networks. First, secure computation can be used to support Private Smart Contracts, where consensus is reached without exposing the information in the public contract. Second, it enables data to be shared and used in trustless network, without disclosing the raw data during data-at-use, where data ownership and data usage is safely separated. Last but not least, computation and verification processes are separated, which can be perceived as computational sharding, this effectively makes the transaction processing speed linear to the number of participating nodes. Our objective is to deploy our secure computation network as an layer2 solution to any blockchain system. Smart Contracts\cite{smartcontract} will be used as bridge to link the blockchain and computation networks. Additionally, they will be used as verifier to ensure that outsourced computation is completed correctly. In order to achieve this, we first develop a general MPC network with advanced features, such as: 1) Secure Computation, 2) Off-chain Computation, 3) Verifiable Computation, and 4)Support dApps' needs like privacy-preserving data exchange

    Port capacity expansion under real options approach: a case study in Brazil

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    Investments in port container terminals are sensitive to uncertainties. Public investments in infrastructure have been significantly reduced in the last decade in developing countries. The Brazilian government infrastructure investment was only 1.85 % of GDP in 2019, representing the lowest level in the last fifty years. Nonetheless, the regulatory framework of the port sector in Brazil has undergone significant changes over time, increasing the number of private port container terminal leases. The expansion capacity of the private port facilities is strongly linked to the demand uncertainty, which impacts the financial return to the long run. In this scenario, the uncertainty of global cargo transportation can discourage infrastructure investments in this class of project in Brazil. To overcome these issues, the financial modelling applying real options approach is better suited than the traditional valuation methods based on Discounted Cash Flow (DCF) analysis. The present study aims to value flexibilities of anticipating, or postponing, or interrupting investments of an existing operational port terminal in Brazil with expansion capacity under the demand uncertainty. The financial decision to invest in a port expansion is modeled by an American option. The results demonstrate that the investor adds significant value to the project by having the possibility to postpone investments. The proposed model presents the contribution of optimizing the decision of sequential expansions of capacity in port terminals, at any time and according to scenarios' revelation. In addition, the model allows the government authorities to review lease contracts, considering the relevance of timing to invest in project expansion decisions. The proposed model can also be extended to other infrastructure projects in emerging economies

    A Metric for Measuring Customer Turnover Prediction Models

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    The interest for data mining techniques has increased tremendously during the past decades, and numerous classification techniques have been applied in a wide range of business applications. Hence, the need for adequate performance measures has become more important than ever. In this application, a cost-benefit analysis framework is formalized in order to define performance measures which are aligned with the main objectives of the end users, i.e., profit maximization. A new performance measure is defined, the expected maximum profit criterion. This general framework is then applied to the customer churn problem with its particular cost-benefit structure. The advantage of this approach is that it assists companies with selecting the classifier which maximizes the profit. Moreover, it aids with the practical implementation in the sense that it provides guidance about the fraction of the customer base to be included in the retention campaign
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