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  • 1
    Online Resource
    Online Resource
    Institute for Operations Research and the Management Sciences (INFORMS) ; 2024
    In:  Manufacturing & Service Operations Management Vol. 26, No. 2 ( 2024-03), p. 447-464
    In: Manufacturing & Service Operations Management, Institute for Operations Research and the Management Sciences (INFORMS), Vol. 26, No. 2 ( 2024-03), p. 447-464
    Abstract: Problem definition: Uncrewed aerial vehicles (UAVs) are transforming emergency service logistics applications across sectors, offering easy deployment and rapid response. In the context of emergency medical services (EMS), UAVs have the potential to augment ambulances by leveraging bystander assistance, thereby reducing response times for delivering urgent medical interventions and improving EMS outcomes. Notably, the use of UAVs for opioid overdose cases is particularly promising as it addresses the challenges faced by ambulances in delivering timely medication. This study aims to optimize the integration of UAVs and bystanders into EMS in order to minimize average response times for overdose interventions. Methodology/results: We formulate the joint operation of UAVs with ambulances through a Markov decision process that captures random emergency vehicle travel times and bystander availability. We apply an approximate dynamic programming approach to mitigate the solution challenges from high-dimensional state variables and complex decisions through a neural network-based approximation of the value functions (NN-API). To design the approximation, we construct a set of basis functions based on queueing and geographic properties of the UAV-augmented EMS system. Managerial implications: The simulation results suggest that our NN-API policy tends to outperform several noteworthy rule- and optimization-based benchmark policies in terms of accumulated rewards, particularly for situations that are primarily characterized by high request arrival rates and a limited number of available ambulances and UAVs. The results also demonstrate the benefits of incorporating UAVs into the EMS system and the effectiveness of an intelligent real-time operations strategy in addressing capacity shortages, which are often a problem in rural areas of the United States. Additionally, the results provide insights into specific contributions of each dispatching or redeployment strategy to overall performance improvement. Funding: This work was supported by the National Science [Grant 1761022]. Supplemental Material: The online appendix is available at https://doi.org/10.1287/msom.2022.0166
    Type of Medium: Online Resource
    ISSN: 1523-4614 , 1526-5498
    RVK:
    Language: English
    Publisher: Institute for Operations Research and the Management Sciences (INFORMS)
    Publication Date: 2024
    detail.hit.zdb_id: 2021015-2
    detail.hit.zdb_id: 2023273-1
    SSG: 3,2
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  • 2
    Online Resource
    Online Resource
    SAGE Publications ; 2007
    In:  Journal of International Marketing Vol. 15, No. 4 ( 2007-12), p. 41-62
    In: Journal of International Marketing, SAGE Publications, Vol. 15, No. 4 ( 2007-12), p. 41-62
    Abstract: In response to numerous calls for the cross-cultural validation of measures used in international research, the authors assess measurement invariance of the export market orientation (EMO) and export performance (EP) constructs using 491 Chinese and non-Chinese export ventures in China. The results show that both the EMO and the EP scales are invariant between Chinese and non-Chinese export ventures. In addition, different EMO components have differential effects on EP for Chinese versus non-Chinese firms. To achieve higher EP, Chinese firms should focus on export intelligence responsiveness, and non-Chinese firms should concentrate their efforts on export intelligence generation. The authors discuss implications and suggest directions for further research.
    Type of Medium: Online Resource
    ISSN: 1069-031X , 1547-7215
    RVK:
    Language: English
    Publisher: SAGE Publications
    Publication Date: 2007
    detail.hit.zdb_id: 915508-9
    detail.hit.zdb_id: 2070132-9
    SSG: 3,2
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  • 3
    Online Resource
    Online Resource
    SAGE Publications ; 2017
    In:  Production and Operations Management Vol. 26, No. 7 ( 2017-07), p. 1399-1415
    In: Production and Operations Management, SAGE Publications, Vol. 26, No. 7 ( 2017-07), p. 1399-1415
    Abstract: We examine the critical role of advance supply signals—such as suppliers’ financial health and production viability—in dynamic supply risk management. The firm operates an inventory system with multiple demand classes and multiple suppliers. The sales are discretionary and the suppliers are susceptible to both systematic and operational risks. We develop a hierarchical Markov model that captures the essential features of advance supply signals, and integrate it with procurement and selling decisions. We characterize the optimal procurement and selling policy, and the strategic relationship between signal‐based forecast, multi‐sourcing, and discretionary selling. We show that higher demand heterogeneity may reduce the value of discretionary selling, and that the mean value‐based forecast may outperform the stationary distribution‐based forecast. This work advances our understanding on when and how to use advance supply signals in dynamic risk management. Future supply risk erodes profitability but enhances the marginal value of current inventory. A signal of future supply shortage raises both base stock and demand rationing levels, thereby boosting the current production and tightening the current sales. Signal‐based dynamic forecast effectively guides the firm's procurement and selling decisions. Its value critically depends on supply volatility and scarcity. Ignoring advance supply signals can result in misleading recommendations and severe losses. Signal‐based dynamic supply forecast should be used when: (a) supply uncertainty is substantial, (b) supply‐demand ratio is moderate, (c) forecast precision is high, and (d) supplier heterogeneity is high.
    Type of Medium: Online Resource
    ISSN: 1059-1478 , 1937-5956
    RVK:
    Language: English
    Publisher: SAGE Publications
    Publication Date: 2017
    detail.hit.zdb_id: 2151364-8
    detail.hit.zdb_id: 1108460-1
    SSG: 3,2
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  • 4
    Online Resource
    Online Resource
    Wiley ; 2022
    In:  Mobile Information Systems Vol. 2022 ( 2022-3-31), p. 1-11
    In: Mobile Information Systems, Wiley, Vol. 2022 ( 2022-3-31), p. 1-11
    Abstract: Due to the characteristics of sensor networks, wireless sensor networks (WSN) have a series of security threats in their applications. For example, wireless sensor networks are vulnerable to attacks such as eavesdropping, data tampering, and jamming. The processing capacity of sensor nodes is limited, and its integrity and confidentiality are greatly threatened. Nodes are easily captured or counterfeited; control of the energy of nodes; encryption and decryption of data depends on the distribution and management of keys; how to ensure the legal networking and access of nodes, etc. With the deepening and gradual promotion of WSN research, these security threats have become an urgent problem to be solved. In the context of multisensor fusion, this research realized the construction of a security perception model of emergency wireless communication based on the Bicycle data symmetric encryption algorithm and the use of secret sharing technology. The 16 bit Bicycle encryption and decryption time is about 1/40 of the encryption time, and the 32 bit Bicycle decryption time is about 1/30 of the encryption time, 16 bit encryption is slower than 32 bit encryption and faster decryption.
    Type of Medium: Online Resource
    ISSN: 1875-905X , 1574-017X
    RVK:
    Language: English
    Publisher: Wiley
    Publication Date: 2022
    detail.hit.zdb_id: 2249294-X
    detail.hit.zdb_id: 2187808-0
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