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Hashing Schemes
Published in Weidong Wu, Packet Forwarding Technologies, 2007
There are at most O(log W) markers to insert for each real prefix, and each prefix and marker need a rope, which can be calculated from the SLS in O(log W). Thus, the overall work is O(N max(W, log2W)). We are working on a faster and more elegant algorithm to build the rope search data structure in time O(N log2W) (that also does not require building a trie).
Mental wellbeing; Human reliability assessment of seafarers during the COVID-19 era
Published in Journal of International Maritime Safety, Environmental Affairs, and Shipping, 2023
Desmond Onakpojeruo, Byongug Jeong, Chybyung Park
To illustrate the events conducted leading to mooring rope failure, an event tree analysis is used. For the credibility of this analysis and to align it to the previous assessment carried out using the HEART methodology, the total HEP value of both scenarios was integrated into the event tree as the initiating frequency to further show its impact on the probability of occurrences and the outcomes. Also as seen in the analysis, the probability of occurrences for each failure of safety conditions leading to the failure of the system increases for an identical system because of the HEP value that points to the impact of lockdown on the operation. Due to a lack of data for each event, expert judgment was implemented to weigh each subsequent event on success (YES) or failure (NO). From the analysis, three outcomes lead to system failure in both scenarios but the probability of occurrences increased when the impact of COVID-19 was factored into the second scenario using the HEP value. Furthermore, the research shows the PLL as a support to the event tree analysis calculated. Using the probability frequency of the event that cut across all the safety conditions but also resulted in system failure before and during COVID-19 as 1.8231E–4 and 1.5304E–3 respectively.
Modelling and passive control of flexible guiding hoisting system with time-varying length
Published in Mathematical and Computer Modelling of Dynamical Systems, 2020
Naige Wang, Guohua Cao, Lu Yan, Lei Wang
The constraint of the hoisting conveyance and the guiding rope is time-varying, which has a certain influence on each transverse natural frequency of the guiding rope. Since the pretensions of the two guiding ropes are different, the transverse natural frequencies of the corresponding orders are separated from each other as shown in Figure 6(c). It can be seen that the j-th natural frequency of the guiding rope with is similar to the -th mode of the tension string fixed at both ends. When the hoisting conveyance is close to the wellhead or the bottom, the first natural frequency of the guiding rope can be verified by the empirical formula of the frequency of the tension string fixed at both ends as followed:
Dynamic modelling and analysis of 3-axis motion compensated offshore cranes
Published in Ships and Offshore Structures, 2018
Shenghai Wang, Yuqing Sun, Haiquan Chen, Jialu Du
As mentioned before, the rope tension is the external force of the back recursion of the dynamic equations of the ship–crane–crane tip system, and it has to be expressed in x6y6z6. Also, xQyQzQ has the same orientation as x0y0z0, thus we know where 60R is given by Equation (5).