Vessel-shaped fish cages are promising large aquaculture structures developed in recent years,with an overall length of nearly 400 m.In this paper,a coupled hydroelasticity model of a vessel-shaped fish cage is used t...Vessel-shaped fish cages are promising large aquaculture structures developed in recent years,with an overall length of nearly 400 m.In this paper,a coupled hydroelasticity model of a vessel-shaped fish cage is used to calculate the motion and structural response in the time domain.First,the floating body of the cage is discretized into a multimodule system to calculate the frequency-domain hydrodynamic loads.Then,the multimodule system is connected by equivalent elastic beams to consider the hydroelastic be-havior in the time domain.The hydrodynamic loads of the multimodule system are transformed from the frequency-domain loads.Moreover,based on the velocity field transfer functions and the motion of the multimodule system,coupling wave fields considering incident,diffraction and radiation waves are built and used to calculate the loads on the net and steel frame.By iterating the motion response of the multi-module system and the hydrodynamic loads on the net and steel frame in the time domain,the balanced hydroelasticity response of the whole cage is finally obtained.The results show that the hydroelasticity effects have a significant influence on the vertical displacement and cross-sectional load effects of the vessel-shaped fish cage.展开更多
For block ciphers,Bogdanov et al.found that there are some linear approximations satisfying that their biases are deterministically invariant under key difference.This property is called key difference invariant bias....For block ciphers,Bogdanov et al.found that there are some linear approximations satisfying that their biases are deterministically invariant under key difference.This property is called key difference invariant bias.Based on this property,Bogdanov et al.proposed a related-key statistical distinguisher and turned it into key-recovery attacks on LBlock and TWINE-128.In this paper,we propose a new related-key model by combining multidimensional linear cryptanalysis with key difference invariant bias.The main theoretical advantage is that our new model does not depend on statistical independence of linear approximations.We demonstrate our cryptanalysis technique by performing key recovery attacks on LBlock and TWINE-128.By using the relations of the involved round keys to reduce the number of guessed subkey bits.Moreover,the partial-compression technique is used to reduce the time complexity.We can recover the master key of LBlock up to 25 rounds with about 260.4 distinct known plaintexts,278.85 time complexity and 261 bytes of memory requirements.Our attack can recover the master key of TWINE-128 up to 28 rounds with about 261.5 distinct known plaintexts,2126.15 time complexity and 261 bytes of memory requirements.The results are the currently best ones on cryptanalysis of LBlock and TWINE-128.展开更多
For block ciphers,Bogdanov et al.found that there are some linear approximations satisfying that their biases are deterministically invariant under key difference.This property is called key difference invariant bias....For block ciphers,Bogdanov et al.found that there are some linear approximations satisfying that their biases are deterministically invariant under key difference.This property is called key difference invariant bias.Based on this property,Bogdanov et al.proposed a related-key statistical distinguisher and turned it into key-recovery attacks on LBlock and TWINE-128.In this paper,we propose a new related-key model by combining multidimensional linear cryptanalysis with key difference invariant bias.The main theoretical advantage is that our new model does not depend on statistical independence of linear approximations.We demonstrate our cryptanalysis technique by performing key recovery attacks on LBlock and TWINE-128.By using the relations of the involved round keys to reduce the number of guessed subkey bits.Moreover,the partial-compression technique is used to reduce the time complexity.We can recover the master key of LBlock up to 25 rounds with about 2^(60.4)distinct known plaintexts,2^(78.85)time complexity and 2^(61)bytes of memory requirements.Our attack can recover the master key of TWINE-128 up to 28 rounds with about 2^(61.5)distinct known plaintexts,2^(126.15)time complexity and 261 bytes of memory requirements.The results are the currently best ones on cryptanalysis of LBlock and TWINE-128.展开更多
In order to determine the effect of twine thickness on the size-selectivity of the driftnet used for the yellow croaker, size-selectivity tests were conducted with three different twine thicknesses(monofi lament diame...In order to determine the effect of twine thickness on the size-selectivity of the driftnet used for the yellow croaker, size-selectivity tests were conducted with three different twine thicknesses(monofi lament diameters of 0.279 mm(number's method; No. 3), 0.321 mm(No. 4), and 0.360 mm(No. 5)) of driftnets for the yellow croaker in the seas around Chooja-do, Jeju Islands. The selectivity curve was estimated by using Kitahara's method. In order to determine the physical properties of the twine used in the experimental fi shing nets, we measured the breaking load, elongation, and stiffness under both dry and wet conditions. In terms of physical properties, the thinnest twine(No. 3) had the strongest breaking strength per unit cross-sectional area, along with good elongation and excellent fl exibility. The thickest twine(No. 5) had the lowest fl exibility. In terms of selectivity, the net of No. 3 twine showed the broadest selection range and, thus, a relatively low selectivity compared with the other nets, while the less fl exible net of No. 5 twine showed the narrowest selectivity range and high selectivity. In addition, it was found that a thicker twine resulted in a smaller haul of small fi sh. Therefore, it can be inferred that the thickness of the twine affects the size of the catch and selectivity, and thus the size composition of the catch as well.展开更多
基金National Natural Sci-ence Foundation of China (Grant No.52088102)National Sci-ence Fund for Distinguished Young Scholars (Grant No.51825903)+4 种基金the Fundamental Research Funds for the Central Universities,Key R&D program of Shandong Province (Grant No.2021SFGC0701)National Natural Science Foundation of China (Grant No.52271283 and Grant No.52111530135)State Key Labo-ratory of Ocean Engineering (Shanghai Jiao Tong University) (Grant No.GKZD010081)Shenlan Project (Grant No.SL2021MS018 and Grant No.SL2022ZD201)the Research Council of Norway through the centre of Excellence Funding Scheme (Grant No.223254).
文摘Vessel-shaped fish cages are promising large aquaculture structures developed in recent years,with an overall length of nearly 400 m.In this paper,a coupled hydroelasticity model of a vessel-shaped fish cage is used to calculate the motion and structural response in the time domain.First,the floating body of the cage is discretized into a multimodule system to calculate the frequency-domain hydrodynamic loads.Then,the multimodule system is connected by equivalent elastic beams to consider the hydroelastic be-havior in the time domain.The hydrodynamic loads of the multimodule system are transformed from the frequency-domain loads.Moreover,based on the velocity field transfer functions and the motion of the multimodule system,coupling wave fields considering incident,diffraction and radiation waves are built and used to calculate the loads on the net and steel frame.By iterating the motion response of the multi-module system and the hydrodynamic loads on the net and steel frame in the time domain,the balanced hydroelasticity response of the whole cage is finally obtained.The results show that the hydroelasticity effects have a significant influence on the vertical displacement and cross-sectional load effects of the vessel-shaped fish cage.
基金the National Natural Science Foundation of China(Grant No.61379138).
文摘For block ciphers,Bogdanov et al.found that there are some linear approximations satisfying that their biases are deterministically invariant under key difference.This property is called key difference invariant bias.Based on this property,Bogdanov et al.proposed a related-key statistical distinguisher and turned it into key-recovery attacks on LBlock and TWINE-128.In this paper,we propose a new related-key model by combining multidimensional linear cryptanalysis with key difference invariant bias.The main theoretical advantage is that our new model does not depend on statistical independence of linear approximations.We demonstrate our cryptanalysis technique by performing key recovery attacks on LBlock and TWINE-128.By using the relations of the involved round keys to reduce the number of guessed subkey bits.Moreover,the partial-compression technique is used to reduce the time complexity.We can recover the master key of LBlock up to 25 rounds with about 260.4 distinct known plaintexts,278.85 time complexity and 261 bytes of memory requirements.Our attack can recover the master key of TWINE-128 up to 28 rounds with about 261.5 distinct known plaintexts,2126.15 time complexity and 261 bytes of memory requirements.The results are the currently best ones on cryptanalysis of LBlock and TWINE-128.
基金supported by the National Natural Science Foundation of China(Grant No.61379138).
文摘For block ciphers,Bogdanov et al.found that there are some linear approximations satisfying that their biases are deterministically invariant under key difference.This property is called key difference invariant bias.Based on this property,Bogdanov et al.proposed a related-key statistical distinguisher and turned it into key-recovery attacks on LBlock and TWINE-128.In this paper,we propose a new related-key model by combining multidimensional linear cryptanalysis with key difference invariant bias.The main theoretical advantage is that our new model does not depend on statistical independence of linear approximations.We demonstrate our cryptanalysis technique by performing key recovery attacks on LBlock and TWINE-128.By using the relations of the involved round keys to reduce the number of guessed subkey bits.Moreover,the partial-compression technique is used to reduce the time complexity.We can recover the master key of LBlock up to 25 rounds with about 2^(60.4)distinct known plaintexts,2^(78.85)time complexity and 2^(61)bytes of memory requirements.Our attack can recover the master key of TWINE-128 up to 28 rounds with about 2^(61.5)distinct known plaintexts,2^(126.15)time complexity and 261 bytes of memory requirements.The results are the currently best ones on cryptanalysis of LBlock and TWINE-128.
基金Supported by the National Institute of Fisheries Science(No.R2015041)
文摘In order to determine the effect of twine thickness on the size-selectivity of the driftnet used for the yellow croaker, size-selectivity tests were conducted with three different twine thicknesses(monofi lament diameters of 0.279 mm(number's method; No. 3), 0.321 mm(No. 4), and 0.360 mm(No. 5)) of driftnets for the yellow croaker in the seas around Chooja-do, Jeju Islands. The selectivity curve was estimated by using Kitahara's method. In order to determine the physical properties of the twine used in the experimental fi shing nets, we measured the breaking load, elongation, and stiffness under both dry and wet conditions. In terms of physical properties, the thinnest twine(No. 3) had the strongest breaking strength per unit cross-sectional area, along with good elongation and excellent fl exibility. The thickest twine(No. 5) had the lowest fl exibility. In terms of selectivity, the net of No. 3 twine showed the broadest selection range and, thus, a relatively low selectivity compared with the other nets, while the less fl exible net of No. 5 twine showed the narrowest selectivity range and high selectivity. In addition, it was found that a thicker twine resulted in a smaller haul of small fi sh. Therefore, it can be inferred that the thickness of the twine affects the size of the catch and selectivity, and thus the size composition of the catch as well.
