The escalating costs of research and development, coupled with the influx of researchers, have led to a surge in published articles across scientific disciplines. However, concerns have arisen regarding the accuracy, ...The escalating costs of research and development, coupled with the influx of researchers, have led to a surge in published articles across scientific disciplines. However, concerns have arisen regarding the accuracy, validity, and reproducibility of reported findings. Issues such as replication problems, fraudulent practices, and a lack of expertise in measurement theory and uncertainty analysis have raised doubts about the reliability and credibility of scientific research. Rigorous assessment practices in certain fields highlight the importance of identifying potential errors and understanding the relationship between technical parameters and research outcomes. To address these concerns, a universally applicable criterion called comparative certainty is urgently needed. This criterion, grounded in an analysis of the modeling process and information transmission, accumulation, and transformation in both theoretical and applied research, aims to evaluate the acceptable deviation between a model and the observed phenomenon. It provides a theoretically grounded framework applicable to all scientific disciplines adhering to the International System of Units (SI). Objective evaluations based on this criterion can enhance the reproducibility and reliability of scientific investigations, instilling greater confidence in published findings. Establishing this criterion would be a significant stride towards ensuring the robustness and credibility of scientific research across disciplines.展开更多
This paper presents a systematic model test program to assess the uncertainty of the ship-bank interaction forces,using the planar motion mechanism(PMM)system in a circulating water channel(CWC).Therefore,the uncertai...This paper presents a systematic model test program to assess the uncertainty of the ship-bank interaction forces,using the planar motion mechanism(PMM)system in a circulating water channel(CWC).Therefore,the uncertainties due to ship-bank distance and water depth are considered,and they are calculated via the partial differentials of the regression formulae based on the test data.The general part of the uncertainty analysis(UA)is performed according to the ITTC recommended procedure 7.5-02-06.04,while the uncertainty of speed is identified as the bias limit due to the flow velocity maldistribution in the CWC.In each example test for the UA of ship-bank interaction forces,12 repeated measurements were conducted.Results from the UA show that the contribution of water depth error and flow velocity maldistribution to the total uncertainty is noticeable,and the paper explains how they increase with the change of the test conditions.The present study will be useful in understanding the uncertainty regarding the ship-bank interaction force measurement in a CWC.展开更多
This paper considers a hotel supply chain consisting of a hotel and an online travel agent （OTA） for the distribution of a limited number of rooms through both offline and online channels. Under the merchant coopera...This paper considers a hotel supply chain consisting of a hotel and an online travel agent （OTA） for the distribution of a limited number of rooms through both offline and online channels. Under the merchant cooperation assumption, to overcome the disadvantages of the decentralized decision model and demand uncertainty, two collaboration mechanisms, namely a two-stage ordering contract and an option contract, are introduced to increase the profit in the hotel supply chain. This paper investigates the optimal decisions of the hotel and the OTA under different contract models. Moreover, the authors analyze the effect of demand uncertainty and the interaction of demand variability and the hotel＇s capacity on the profits of the hotel and the OTA under different models. The results show that both the two-stage ordering contract and the option contract can increase the profits of the entire supply chain and the hotel; however, the profit of the OTA can be increased through the two-stage ordering contract and option contract only when the hotel＇s capacity is relatively small and the demand variability is big; otherwise, the two collaboration mechanisms cannot increase the OTA＇s profit.展开更多
Physical layer security is an emerging technique for improving wireless communication security, which is widely regarded as a complement to cryptographic technologies. To design physical layer security techniques for ...Physical layer security is an emerging technique for improving wireless communication security, which is widely regarded as a complement to cryptographic technologies. To design physical layer security techniques for practical scenarios, uncertainty and imperfections in the channel knowledge need to be taken into account. This paper is a survey of recent research on physical layer security that considers imperfect channel state information （CSI） at communication nodes. We first give an overview of the main information-theoretic measures of secrecy performance with imperfect CSI. Then, we describe several signal processing enhancements in secure transmission designs. These enhancements include secure on-off transmission, beamforming with artificial noise, and secure communication assisted by relay nodes or in cognitive radio systems. Recent studies of physical layer security in large-scale decentralized wireless networks are also summarized. Finally, open problems for on-going and future research are discussed.展开更多
文摘The escalating costs of research and development, coupled with the influx of researchers, have led to a surge in published articles across scientific disciplines. However, concerns have arisen regarding the accuracy, validity, and reproducibility of reported findings. Issues such as replication problems, fraudulent practices, and a lack of expertise in measurement theory and uncertainty analysis have raised doubts about the reliability and credibility of scientific research. Rigorous assessment practices in certain fields highlight the importance of identifying potential errors and understanding the relationship between technical parameters and research outcomes. To address these concerns, a universally applicable criterion called comparative certainty is urgently needed. This criterion, grounded in an analysis of the modeling process and information transmission, accumulation, and transformation in both theoretical and applied research, aims to evaluate the acceptable deviation between a model and the observed phenomenon. It provides a theoretically grounded framework applicable to all scientific disciplines adhering to the International System of Units (SI). Objective evaluations based on this criterion can enhance the reproducibility and reliability of scientific investigations, instilling greater confidence in published findings. Establishing this criterion would be a significant stride towards ensuring the robustness and credibility of scientific research across disciplines.
基金This study is financially supported by the China Ministry of Education Key Research Project“KSHIP-II Project”(Grant No.GKZY010004).
文摘This paper presents a systematic model test program to assess the uncertainty of the ship-bank interaction forces,using the planar motion mechanism(PMM)system in a circulating water channel(CWC).Therefore,the uncertainties due to ship-bank distance and water depth are considered,and they are calculated via the partial differentials of the regression formulae based on the test data.The general part of the uncertainty analysis(UA)is performed according to the ITTC recommended procedure 7.5-02-06.04,while the uncertainty of speed is identified as the bias limit due to the flow velocity maldistribution in the CWC.In each example test for the UA of ship-bank interaction forces,12 repeated measurements were conducted.Results from the UA show that the contribution of water depth error and flow velocity maldistribution to the total uncertainty is noticeable,and the paper explains how they increase with the change of the test conditions.The present study will be useful in understanding the uncertainty regarding the ship-bank interaction force measurement in a CWC.
基金supported by the National Natural Science Foundation of China under Grant Nos.71471066,71371006,71090403Program for New Century Excellent Talents in University(NCET-13-0219)Research Fund for the Doctoral Program of Higher Education of China under Grant No.20130172110029
文摘This paper considers a hotel supply chain consisting of a hotel and an online travel agent （OTA） for the distribution of a limited number of rooms through both offline and online channels. Under the merchant cooperation assumption, to overcome the disadvantages of the decentralized decision model and demand uncertainty, two collaboration mechanisms, namely a two-stage ordering contract and an option contract, are introduced to increase the profit in the hotel supply chain. This paper investigates the optimal decisions of the hotel and the OTA under different contract models. Moreover, the authors analyze the effect of demand uncertainty and the interaction of demand variability and the hotel＇s capacity on the profits of the hotel and the OTA under different models. The results show that both the two-stage ordering contract and the option contract can increase the profits of the entire supply chain and the hotel; however, the profit of the OTA can be increased through the two-stage ordering contract and option contract only when the hotel＇s capacity is relatively small and the demand variability is big; otherwise, the two collaboration mechanisms cannot increase the OTA＇s profit.
文摘Physical layer security is an emerging technique for improving wireless communication security, which is widely regarded as a complement to cryptographic technologies. To design physical layer security techniques for practical scenarios, uncertainty and imperfections in the channel knowledge need to be taken into account. This paper is a survey of recent research on physical layer security that considers imperfect channel state information （CSI） at communication nodes. We first give an overview of the main information-theoretic measures of secrecy performance with imperfect CSI. Then, we describe several signal processing enhancements in secure transmission designs. These enhancements include secure on-off transmission, beamforming with artificial noise, and secure communication assisted by relay nodes or in cognitive radio systems. Recent studies of physical layer security in large-scale decentralized wireless networks are also summarized. Finally, open problems for on-going and future research are discussed.
