Formal Verification Platform as a Service:WebAssembly Vulnerability Detection Application

In order to realize a general-purpose automatic formal verification platform based on WebAssembly technology as a web service(FVPS),which aims to provide an automated report of vulnerability detections,this work builds a Hyperledger Fabric blockchain runtime model.It proposes an optimized methodology of the functional equivalent translation from source program languages to formal languages.This methodology utilizes an external application programming interface(API)table to replace the source codes in compilation,thereby pruning the part of housekeeping codes to ease code inflation.Code inflation is a significant metric in formal language translation.Namely,minor code inflation enhances verification scale and performance efficiency.It determines the efficiency of formal verification,involving launching,running,and memory usage.For instance,path explosion increases exponentially,resulting in out-of-memory.The experimental results conclude that program languages like golang severely impact code inflation.FVPS reduces the wasm code size by over 90%,achieving two orders of optimization magnitude,from 2000 kilobyte(KB)to 90 KB.That means we can cope with golang applications up to 20 times larger than the original in scale.This work eliminates the gap between Hyperledger Fabric smart contracts and WebAssembly.Our approach is pragmatic,adaptable,extendable,and flexible.Nowadays,FVPS is successfully applied in a Railway-Port-Aviation blockchain transportation system.

Laser Powder Bed Fusion Processing of Soft Magnetic Fe–Ni–Si Alloys: Effect of Hot Isostatic Pressing Treatment

Laser powder bed fusion(L-PBF)-processed high-silicon steel has great advantages in freely designed electric engines,and various studies have been conducted in this field.However,the analysis of both the mechanical and magnetic properties,focusing on the multiscale microstructure under as-fabricated and heat-treated conditions,which is indispensable for industrial applications,has not been performed.In this study,an Fe–Ni–Si sample was fabricated using the L-PBF process.Subsequently,the following hot isotropic pressing(HIPing)process was employed as a post heat treatment step for the Fe–Ni–Si alloys.The effects of HIPing on the microstructure were investigated,focusing on the metastable stable phase transformation in the Fe–Ni–Si system.X-ray diffraction results showed single-phase fccγ(Fe,Ni)in the L-PBF-processed samples before and after HIPing.Moreover,the acicular Ni/Si-rich structure(formed in the as-fabricated L-PBF sample because of its high cooling rates)transformed to the equilibrium austenite,Ni3Si,and FeNi3 phases during HIPing.After HIP,the compressive modulus and strength increased from 11 GPa and 650 MPa to approximately 18 GPa and 900 MPa,respectively.The magnetic properties were evaluated via a hysteresis loop,and the coercivity increased from 1.8 kA/m and to 2.9 kA/m after the HIPing process.