Ocean surface current retrieval and imaging with a new shore-based X-band radar based on time-shifted up-and-down linear frequency modulated signal

This paper proposes a multifunction radar that can not only measure sea currents but also perform sea-surface imaging.The fundamental aspect of the proposed radar comprises transmitting time-shifted up-and-down continuous wave linear frequency modulated signals that allow for the offset of two one-dimensional range images of the sea surface that respectively correspond to the upward linear frequency modulated(LFM)signal and the downward LFM signal.Owing to the Doppler frequency shift from the sea surface,a range offset,which is proportional to the radial velocity of the sea surface,occurs between the upward and downward LFM signals.By using the least-squares linear fitting method in the transformed domain,the range offset can be measured and the current velocity can be retrieved.Finally,we verify the accuracy of current measurement with simulation results.

A supplier evaluation model based on customer demand in blockchain tracing anti-counterfeiting platform project management

This study assesses supplier selection at the beginning of project management to establish an evaluation system corresponding to blockchain tracing anti-counterfeiting platforms(BTAP).First,this paper determines 20 evaluation criteria from the four dimensions of platform overview,core technology,application support,and operations management.On this basis,multi-criteria decision making(MCDM)based on customer needs is proposed,which consists of three main steps.First,quality function deployment(QFD)and the best and worst method(BWM)are used to evaluate the four dimensions of the BTAP and specific evaluation criteria from the perspective of customers to obtain the criteria weight.Then,this method uses the extended Vlse Kriterjumska Optimizacija I Kompromisno Resenje(VIKOR)approach to sort the alternatives.Finally,the improved decision making trial and evaluation laboratory(DEMATEL)method is used to analyse the relationships between the 20 criteria in the four dimensions.The feasibility and effectiveness of this method are verified by an example.According to the sensitivity analysis and comparative analysis,the results show that this method can evaluate blockchain anti-counterfeiting enterprises.The main conclusions are as follows:the core technology is the most impor-tant factor influencing the choice of a BTAP project,and the role of application support in evaluation cannot be ignored.