Deep Intellectual Property: A Survey

With the widespread application in industrial manufacturing and commercial services, well-trained deep neural networks (DNNs) are becoming increasingly valuable and crucial assets due to the tremendous training cost and excellent generalization performance. These trained models can be utilized by users without much expert knowledge benefiting from the emerging ''Machine Learning as a Service'' (MLaaS) paradigm. However, this paradigm also exposes the expensive models to various potential threats like model stealing and abuse. As an urgent requirement to defend against these threats, Deep Intellectual Property (DeepIP), to protect private training data, painstakingly-tuned hyperparameters, or costly learned model weights, has been the consensus of both industry and academia. To this end, numerous approaches have been proposed to achieve this goal in recent years, especially to prevent or discover model stealing and unauthorized redistribution. Given this period of rapid evolution, the goal of this paper is to provide a comprehensive survey of the recent achievements in this field. More than 190 research contributions are included in this survey, covering many aspects of Deep IP Protection: challenges/threats, invasive solutions (watermarking), non-invasive solutions (fingerprinting), evaluation metrics, and performance. We finish the survey by identifying promising directions for future research.Comment: 38 pages, 12 figure

Study on Thermal Properties and Mechanical Properties of Short-cut Polyimide-Fiber Reinforced Polyphenyl Sulfone Composites

In order to increase the thermal stability and mechanical property of PPSU, two different polyimide (PI) short cut fibers reinforced polyphenyl sulfone (PPSU) composites were prepared by melt extrusion using a threescrew extruder. In addition, the effects of fiber lengths on thermal stability, heat resistance and mechanical properties of the composites was studied. The results indicate that the addition of polyimide chopped fiber can greatly improve the heat resistance of the composites. Comparing with PPSU, with the increasing of fiber content, the heat deformation temperature (HDT) of composites increased from 205 °C to 229 °C, but the addition of polyimide fiber has limited effect on the thermal stability of the composites. Meanwhile, the addition of polyimide chopped fiber can also improve the mechanical properties of the composites. Compared with PPSU, the tensile strength of composites can be increased by 102%, and the bending strength can be raised by 117%

Chaperone Spy Protects Outer Membrane Proteins from Folding Stress via Dynamic Complex Formation

Gram-negative bacteria have a multicomponent and constitutively active periplasmic chaperone system to ensure the quality control of their outer membrane proteins (OMPs). Recently, OMPs have been identified as a new class of vulnerable targets for antibiotic development, and therefore a comprehensive understanding of OMP quality control network components will be critical for discovering antimicrobials. Here, we demonstrate that the periplasmic chaperone Spy protects certain OMPs against protein-unfolding stress and can functionally compensate for other periplasmic chaperones, namely Skp and FkpA, in the Escherichia coli K-12 MG1655 strain. After extensive; in vivo; genetic experiments for functional characterization of Spy, we use nuclear magnetic resonance and circular dichroism spectroscopy to elucidate the mechanism by which Spy binds and folds two different OMPs. Along with holding OMP substrates in a dynamic conformational ensemble, Spy binding enables OmpX to form a partially folded β-strand secondary structure. The bound OMP experiences temperature-dependent conformational exchange within the chaperone, pointing to a multitude of local dynamics. Our findings thus deepen the understanding of functional compensation among periplasmic chaperones during OMP biogenesis and will promote the development of innovative antimicrobials against pathogenic Gram-negative bacteria.; IMPORTANCE; Outer membrane proteins (OMPs) play critical roles in bacterial pathogenicity and provide a new niche for antibiotic development. A comprehensive understanding of the OMP quality control network will strongly impact antimicrobial discovery. Here, we systematically demonstrate that the periplasmic chaperone Spy has a role in maintaining the homeostasis of certain OMPs. Remarkably, Spy utilizes a unique chaperone mechanism to bind OmpX and allows it to form a partially folded β-strand secondary structure in a dynamic exchange of conformations. This mechanism differs from that of other E. coli periplasmic chaperones such as Skp and SurA, both of which maintain OMPs in disordered conformations. Our study thus deepens the understanding of the complex OMP quality control system and highlights the differences in the mechanisms of ATP-independent chaperones

Baichuan 2: Open Large-scale Language Models

Large language models (LLMs) have demonstrated remarkable performance on a variety of natural language tasks based on just a few examples of natural language instructions, reducing the need for extensive feature engineering. However, most powerful LLMs are closed-source or limited in their capability for languages other than English. In this technical report, we present Baichuan 2, a series of large-scale multilingual language models containing 7 billion and 13 billion parameters, trained from scratch, on 2.6 trillion tokens. Baichuan 2 matches or outperforms other open-source models of similar size on public benchmarks like MMLU, CMMLU, GSM8K, and HumanEval. Furthermore, Baichuan 2 excels in vertical domains such as medicine and law. We will release all pre-training model checkpoints to benefit the research community in better understanding the training dynamics of Baichuan 2.Comment: Baichuan 2 technical report. Github: https://github.com/baichuan-inc/Baichuan

Crack Group Effect Analysis of the Stress-Release Boot of Solid Rocket Motor Based on Numerical Simulation

Due to the complex process of the insulation layer patch in solid rocket motor (SRM), only manual patch could be used. Sometimes weak bonding or debonding in each joint surface was inevitable. This study is aimed at determining the crack group effect of insulation and interfacial debonded crack in the wide-temperature SRM. The crack group appeared in the front area of the ahead stress-release boot and was induced by low temperature, axial overload, or interface bonding failure. Based on the viscoelastic finite element method, singular crack elements and singular interfacial crack elements at the tips of crack group were established to calculate J-integral. Varying according to the length and position of cracks, the J-integral of crack tips was, respectively, calculated to prejudge their stability and the crack group effect. The results showed that collinear crack group appeared in the front stress-release boot layer, and the crack group had a certain shielding effect on the main crack when the SRM was launched at low temperature. When noncollinear crack group appeared in the front stress-release boot layer, the crack group effect changed with the length of the main crack. The crack group first had a shielding effect on the main crack and then had a strong strengthening effect. The experimental test of the simulated specimen revealed that numerical simulation results matched the experimental test results

The Numerical Simulation Method of the Slot Crack Groups’ Effect Analysis for Solid Rocket Motor Grain

This study is aimed at the stability and effect of the crack groups in the solid rocket motor (SRM) grain when it was launched at normal temperature. Based on the nearly incompressible viscoelastic finite element method, several cracks were preset in a critical location along with the dangerous point of the back slot. The singular crack elements at the tips of crack groups were established to calculate the J-integral. With the position of the cracks, the J-integral of the various crack tips was, respectively, calculated to prejudge its stability and the group effect. Finally, the experimental measured critical J-integral JIC was compared with the numerical simulation result. The results showed that in the collinear crack groups, the enhancement effect of the main crack was caused by the nearest second crack, and the significant shielding effect of the main crack was occurred in the noncollinear crack groups. Moreover, the experimental result showed that the numerical method had high accuracy

Research on the Numerical Simulation of Aircraft Cabin Smoke

AbstractThe aircraft cabin environment smoke accident can threaten the flight safety seriously. According to the incomplete statistics, the cabin smoke accident happens one time in every 5,000 flights. As a result, more attention is paid on the airworthiness validation of the cabin smoke to ensure the aircraft safety. However, lacking the knowledge of the diffusion law of cabin smoke sometimes makes the validation experiment of the cabin smoke dangerous and expensive. With the rapid progress of computer technology, computational fluid dynamics (CFD) is widely used. In addition, utilizing computer modeling and simulation before the validation experiment can significantly improve the operability and feasibility of the experiment. This paper analyzes the flow regularity of smoke in the aircraft cabin and the influence of ventilation on cabin smoke diffusion by Fluent, which could prove analysis/calculation to be one of airworthiness compliance validation methods and decrease the costs of ground test and flight test which is able to reduce cost and increase efficiency

ZnO interconnected network nanostructures grown on cracked GaN by the aqueous solution method

ZnO interconnected network nanostructures are grown on cracked GaN substrate using aqueous solution method in this paper. ZnO nanostructures nucleate in the sidewall of crack and selectively grow along the crack direction on the GaN substrate. Due to the diversity of the crack, the nanostructures show interconnected network structures. Time-dependent of ZnO nanostructure morphology evolution shows the network nanostructures are formed by self-organized growth by interconnection of nanorods. The average diameter of the nanorods is around 500-600 nm. Micro-Raman spectroscopy shows the nanostructures are under tensile stress. Meanwhile, the nanostructures also show good optical quality. The interconnecting structure characteristics, high degree of networking make them potential applications in ultra-sensitive gas sensing, exciton based photonic devices. (C) 2010 Elsevier B.V. All rights reserved

Study on Thermal Properties and Mechanical Properties of Short-cut Polyimide-Fiber Reinforced Polyphenyl Sulfone Composites

In order to increase the thermal stability and mechanical property of PPSU, two different polyimide (PI) short cut fibers reinforced polyphenyl sulfone (PPSU) composites were prepared by melt extrusion using a threescrew extruder. In addition, the effects of fiber lengths on thermal stability, heat resistance and mechanical properties of the composites was studied. The results indicate that the addition of polyimide chopped fiber can greatly improve the heat resistance of the composites. Comparing with PPSU, with the increasing of fiber content, the heat deformation temperature (HDT) of composites increased from 205 °C to 229 °C, but the addition of polyimide fiber has limited effect on the thermal stability of the composites. Meanwhile, the addition of polyimide chopped fiber can also improve the mechanical properties of the composites. Compared with PPSU, the tensile strength of composites can be increased by 102%, and the bending strength can be raised by 117%

Fabrication of ZrO2(MgO)/CaAl2O4+CaAl4O7 Bilayer Structure Used for Sulfur Sensor by Laser Cladding

The ZrO2(MgO)/CaAl2O4+CaAl4O7 bilayer structure used for sulfur sensor was fabricated by the laser powder cladding (LPC) method using the MgO partially stabilized zirconia (2.7 wt% MgO-PSZ) as the substrate and the CaAl2O4 + CaAl4O7 composites as the coating material. The microstructure, phase composition and ionic conductivity of this bilayer structure were investigated for better application in the sulfur determination. The results indicated that the structure of the coating was dense and well-distributed with a thickness of 100 μm. The ionic conductivity of the ZrO2(MgO)/CaAl2O4+CaAl4O7 bilayer structure was up to 2.06 × 10−3 S·cm−1 at 850 °C that met the required ionic conductivity of ionic conductor for solid electrolyte sulfur sensor. Furthermore, the sulfur sensor Mo|Cr+Cr2O3| ZrO2(MgO)| CaAl2O4+CaAl4O7|[S]Fe| Mo was assembled used this bilayer structure and tested in carbon-saturated liquid iron at 1773 K and 1823 K. The stability and reproducibility of the sulfur sensor were satisfactory and could be used for sulfur determination in the liquid iron