scispace - formally typeset
Search or ask a question
Author

Xiangzhan Yu

Bio: Xiangzhan Yu is an academic researcher. The author has contributed to research in topics: Computer science & Porous medium. The author has an hindex of 1, co-authored 1 publications receiving 233 citations.

Papers
More filters
Journal ArticleDOI
TL;DR: In this article, the authors derived a relation for the fluid motion through thin porous structures in addition to the conventional governing equation and boundary conditions for small-amplitude waves in ideal fluids.
Abstract: Diffraction of water waves by porous breakwaters is studied based on the linear potential wave theory. The formulation of the problem includes a newly derived relation for the fluid motion through thin porous structures in addition to the conventional governing equation and boundary conditions for small-amplitude waves in ideal fluids. The porous boundary condition, indirectly verified by collected experimental data, is obtained by assuming that the flow within the porous medium is governed by a convection-neglected and porous-effect-modeled Euler equation. A vertically two-dimensional problem with long-crested waves propagating in the normal direction of an infinite porous wall is first solved and the solution is compared with available experimental data. The wave diffraction by a semiinfinite porous wall is then studied by the boundary-layer method, in which the outer approximation is formulated by virtue of the reduced two-dimensional solution. It is demonstrated that neglect of the inertial effect of the porous medium leads to an overestimate of the functional performance of a porous breakwater.

280 citations

Journal ArticleDOI
TL;DR: In this article , a double-layer positional encoding based transformer model (DP-Transformer) is proposed to solve the out of vocabulary problem in binary function similarity detection, which is more suitable for the embedding of assembly instructions.
Abstract: The similarity detection between two cross-platform binary functions has been applied in many fields, such as vulnerability detection, software copyright protection or malware classification. Current advanced methods for binary function similarity detection usually use semantic features, but have certain limitations. For example, practical applications may encounter instructions that have not been seen in training, which may easily cause the out of vocabulary (OOV) problem. In addition, the generalization of the extracted binary semantic features may be poor, resulting in a lower accuracy of the trained model in practical applications. To overcome these limitations, we propose a double-layer positional encoding based transformer model (DP-Transformer). The DP-Transformer's encoder is used to extract the semantic features of the source instruction set architecture (ISA), which is called the source ISA encoder. Then, the source ISA encoder is fine-tuned by the triplet loss while the target ISA encoder is trained. This process is called DP-MIRROR. When facing the same semantic basic block, the embedding vectors of the source and target ISA encoders are similar. Different from the traditional transformer which uses single-layer positional encoding, the double-layer positional encoding embedding can solve the OOV problem while ensuring the separation between instructions, so it is more suitable for the embedding of assembly instructions. Our comparative experiment results show that DP-MIRROR outperforms the state-of-the-art approach, MIRROR, by about 35% in terms of precision at 1.

Cited by
More filters
Journal ArticleDOI
TL;DR: In this article, the authors reviewed recent progress in the study of perforated/slotted breakwaters, with an emphasis on two main groups of such breakwaters: (1) perforators with impermeable back walls, and (2) breakwaters without a back-wall.

189 citations

Journal ArticleDOI
TL;DR: In this article, the authors presented a numerical model of wave interactions with a thin vertical slotted barrier extending from the water surface to some distance above the seabed, and described laboratory tests undertaken to assess the numerical model.
Abstract: The present paper outlines the numerical calculation of wave interactions with a thin vertical slotted barrier extending from the water surface to some distance above the seabed, and describes laboratory tests undertaken to assess the numerical model. The numerical model is based on an eigenfunction expansion method and utilizes a boundary condition at the barrier surface that accounts for energy dissipation within the barrier. Numerical results compare well with previous predictions for the limiting cases of an impermeable barrier and a permeable barrier extending down to the seabed. Comparisons with experimental measurements of the transmission, reflection, and energy dissipation coefficients for a partially submerged slotted barrier show good agreement provided certain empirical coefficients of the model are suitably chosen, and indicate that the numerical method is able to account adequately for the energy dissipation by the barrier. The effects of porosity, relative wave length, wave steepness, and irregular waves are discussed and the choice of suitable parameters needed to model the permeability of the breakwater is described.

163 citations

Journal ArticleDOI
TL;DR: In this paper, the authors proposed a simple, inexpensive, and effective type of floating breakwater for deep-sea aquaculture, which can effectively protect fish and fish cages.

114 citations

Journal ArticleDOI
TL;DR: In this article, the reflection and transmission coefficients of a thin vertical porous wall with different porous shapes with different shapes have been analyzed, and the porous effect parameter G has been obtained.
Abstract: The present paper aims at getting the porous effect parameter G of a thin permeable wall. The reflection and transmission coefficients of a thin vertical porous wall with different porous shapes an...

112 citations

Journal ArticleDOI
TL;DR: In this article, the authors presented the numerical calculation of wave interactions with a pair of thin vertical slotted barriers extending from the water surface to some distance above the seabed, and described laboratory tests undertaken to assess the numerical model.

101 citations