Dynamic Modeling and Adaptive Fast Nonsingular Terminal Sliding Mode Control for Satellite with Double Rotary Payloads

A robust attitude control methodology is proposed for satellite system with double rotary payloads.The dynamic model is built by the Newton-Euler method and then the dynamic interconnection between satellite′s main body and payloads is described precisely.A nonlinear disturbance observer is designed for satellite′s main body to estimate disturbance torque acted by motion of payloads.Meanwhile,the adaptive fast nonsingular terminal sliding-mode attitude stabilization controller is proposed for satellite′s main body to quicken convergence speed of state variables.Similarly,the adaptive fast nonsingular terminal sliding-mode attitude maneuver controller is designed for each payload to weaken the disturbance effect of motion of satellite′s main body.Simulation results verify the effectiveness of the proposed method.

Development Progress of China’s First Mars Exploration Mission:Its Scientific Objectives and Payloads

China’s first Mars exploration mission is scheduled to be launched in 2020.It aims not only to conduct global and comprehensive exploration of Mars by use of an orbiter but also to carry out in situ observation of key sites on Mars with a rover.This mission focuses on the following studies:topography,geomorphology,geological structure,soil characteristics,water-ice distribution,material composition,atmosphere and ionosphere,surface climate,environmental characteristics,Mars internal structure,and Martian magnetic field.It is comprised of an orbiter,a lander,and a rover equipped with 13 scientific payloads.This article will give an introduction to the mission including mission plan,scientific objectives,scientific payloads,and its recent development progress.

Predictive Control of Quad-Rotor Delivering Unknown Time-Varying Payloads Based upon Extended State Observer

In this paper, robust control problem is addressed for quad-rotor delivering unknown time-varying payloads. Firstly, the model of a quad-rotor carrying payloads is built. Dynamics of the payloads are treated as disturbances and added into the model of the quad-rotor. Secondly, to enhance system robust-ness, the extended state observer (ESO) is applied to estimate the disturbances from the payloads for feedback compensation. Then a type of predictive controller targeting multiple-input-multiple-output (MIMO) system is developed to degrade the influences caused by sudden changes from load-ing/dropping of the payloads. Finally, by making comparison with the con-ventional cascade proportional-integral-derivative (CPID) and the sliding mode control (SMC) approaches, superiority of the scheme developed is va-lidated. The simulation results indicate that the CPID method shows poor performance on attitude stabilization and the SMC shows input chattering phenomenon even it can achieve satisfied control performances.

The payloads of planetary physics research onboard China’s First Mars Mission (Tianwen-1)

Mars is not only our nearby but also the most Earth-like planetary neighbor.Scientific exploration of Mars is thus of crucial value to our understanding of the solar system.The existence of abundant evidence for the former presence of water on Mars demands further exploration for signs of life on our sister planet,and investigations that could shed light on conditions favorable to the origin of life.For nearly 60 years,humans have conducted orbitally-based remote sensing and in-situ surface exploration of Mars,leading to many significant scientific discoveries.But much remains to be done before we can be sure that we truly and fully understand Mars.Key research topics include the history of water on Mars and how that history relates to the planet’s habitable environment-past,present,and future;the distribution and evolution of waterbearing and evaporative salt minerals on the planet’s surface;the history of volcanic activity on Mars;the Martian magnetic field and its effect on the escape of water and atmosphere from the planet;interactions between the solar wind and the Martian atmosphere and ionosphere;atmospheric characteristics and climate change on Mars;and so on(Li CL et al.,2018;Liu JJ et al.,2018).Based on the above scientific questions about life,climate,and geology on Mars,the international planetary science community has formulated ambitious Mars exploration programs.

Antibody-drug conjugates:Recent advances in payloads

Antibody-drug conjugates(ADCs),which combine the advantages of monoclonal antibodies with precise targeting and payloads with efficient killing,show great clinical therapeutic value.The ADCs’payloads play a key role in determining the efficacy of ADC drugs and thus have attracted great attention in the field.An ideal ADC payload should possess sufficient toxicity,low immunogenicity,high stability,and modifiable functional groups.Common ADC payloads include tubulin inhibitors and DNA damaging agents,with tubulin inhibitors accounting for more than half of the ADC drugs in clinical development.However,due to clinical limitations of traditional ADC payloads,such as inadequate efficacy and the development of acquired drug resistance,novel highly efficient payloads with diverse targets and reduced side effects are being developed.This perspective summarizes the recent research advances of traditional and novel ADC payloads with main focuses on the structure-activity relationship studies,co-crystal structures,and designing strategies,and further discusses the future research directions of ADC payloads.This review also aims to provide valuable references and future directions for the development of novel ADC payloads that will have high efficacy,low toxicity,adequate stability,and abilities to overcome drug resistance.

AppChainer:investigating the chainability among payloads in android applications

Statistics show that more than 80 applications are installed on each android smartphone.Vulnerability research on Android applications is of critical importance.Recently,academic researchers mainly focus on single bug patterns,while few of them investigate the relations between multiple bugs.Industrial researchers proposed a series of logic exploit chains leveraging multiple logic bugs.However,there is no general model to evaluate the chaining abilities between bugs.This paper presents a formal model to elucidate the relations between multiple bugs in Android applications.To prove the effectiveness of the model,we design and implement a prototype system named AppChainer.AppChainer automatically identifies attack surfaces of Android applications and investigates whether the payloads entering these attack surfaces are“chainable”.Experimental results on 2138 popular Android applications show that AppChainer is effective in identifying and chaining attacker-controllable payloads.It identifies 14467 chainable payloads and constructs 5458 chains both inside a single application and among various applications.The time cost and resource consumption of AppChainer are also acceptable.For each application,the average analysis time is 317 s,and the average memory consumed is 2368 MB.Compared with the most relevant work Jandroid,the experiment results on our custom DroidChainBench show that AppChainer outperforms Jandroid at the precision rate and performs equally with Jandroid at the recall rate.

Geoengineering Research Moves from Laboratory to Field

In March 2023,a converted bomber took off from Eielson Air Force Base in Alaska,USA,carrying a payload of delicate scientific instruments(Fig.1).Operated by the US National Oceanic and Atmospheric Administration(NOAA),the flight aimed to collect a plethora of information about the Earth’s stratosphere.Such exploration sounds routine,but the mission’s goal is unusual for a government entity:to inform policy decisions surrounding large-scale,deliberate interventions to alter the stratosphere for climate change mitigation[1].The approach of deflecting sunlight to cool the planet,called solar radiation management or solar geoengineering,was long considered a fringe idea.But with recent funding and attention from government agencies like NOAA,the approach is moving mainstream.

基于eBPF的云环境下payload进程检测方法

针对目前云环境下攻击载荷(payload)所体现出的新特征以及目前检测方法性能损耗较高的问题,提出了一种利用eBPF技术在内核态检测反向连接类payload进程从而定位被入侵容器的方法。该方法在内核态对服务端TCP连接进行监控,通过筛选TCP标志位定位疑似反向连接类payload进程所在容器,并对该容器进程组后续访问文件行为进行追踪以控制损害。实验证明,该方法可以有效检测出并定位被入侵容器,且其性能消耗极低,多线程性能Unixbench分数损耗仅为0.53%。

A Recursive High Payload Reversible Data Hiding Using Integer Wavelet and Arnold Transform

Reversible data hiding is an information hiding technique that requires the retrieval of the error free cover image after the extraction of the secret image.We suggested a technique in this research that uses a recursive embedding method to increase capacity substantially using the Integer wavelet transform and the Arnold transform.The notion of Integer wavelet transforms is to ensure that all coefficients of the cover images are used during embedding with an increase in payload.By scrambling the cover image,Arnold transform adds security to the information that gets embedded and also allows embedding more information in each iteration.The hybrid combination of Integer wavelet transform and Arnold transform results to build a more efficient and secure system.The proposed method employs a set of keys to ensure that information cannot be decoded by an attacker.The experimental results show that it aids in the development of a more secure storage system and withstand few tampering attacks The suggested technique is tested on many image formats,including medical images.Various performance metrics proves that the retrieved cover image and hidden image are both intact.This System is proven to withstand rotation attack as well.

Antibody-Drug Conjugates (ADCs): Navigating Four Pillars of Safety, Development, Supply Chain and Manufacturing Excellence

Antibody-drug conjugates (ADCs) are pioneering biologics that merge antibodies’ specificity with small molecules’ potency. With a handful of FDA-approved ADCs in the market and many under development, ADCs are poised to revolutionize therapeutics. This paper examines the complexities of ADC production, emphasizing the importance of process characterization and the pivotal role of supply chain characteristics, safety requirements, and Contract Manufacturing Organizations (CMOs) with proficiency. The swift transition of antibody-drug conjugate (ADC) programs from early to advanced clinical stages underscores the urgency for quick and efficient commercial launch preparation. This article delves into strategies to hasten commercial readiness, supply chain strategy, the significance of partnering with adept contract development and manufacturing organizations (CDMOs), and the challenges of ADC production.

The ABC of ADCs (Antibody-Drug Conjugates): A Comprehensive Review of Technical, Regulatory, and Clinical Challenges

Over the past several decades, there has been a significant surge in the development of Antibody-Drug Conjugates (ADCs). Designing an ideal ADC presents a multifaceted challenge, requiring the precise orchestration of various elements such as antigens, antibodies, linkers, and payloads. While ADCs aim to target tumor cells specifically, several antigens can also be found in regular tissues, potentially compromising the specificity of ADCs in therapeutic applications. The complexity extends to antibody selection, necessitating effective targeting of the desired antigen and ensuring compatibility with linkers for effective payload delivery. Additionally, the linker and payload combination are critical for the ADC’s therapeutic efficiency, balancing stability in circulation and timely payload release upon target binding. ADC doses must be safe for normal tissues while ensuring the released payloads are effective. The success of ADCs is attributed to their unmatched efficacy compared to traditional chemotherapy agents. The current research article aims to provide a technical review of Antibody-Drug Conjugates (ADCs) for cancer therapies. A brief discussion on the basics of ADCs, regulatory approach, overview, and technical complexities for quantification is presented. This review also summarizes recently approved ADCs and introduces the concepts of antibodies, linkers, and payloads. The article also outlines cancer-specific ADCs currently in late-stage clinical trials for cancer treatment.

SDI信号中Payload ID的解析与应用

广电进入超高清时代以后,作为SDI信号中视频元数据的Payload ID得到了广泛的使用,它所包含的亮度曲线和色域范围等信息为准确处理和还原信号提供了对应的坐标系,是正确进行信号处理的关键因素。本文对SDI信号中Payload ID进行了解析,分析了目前Payload ID在写入、读取、识别和应用的过程中会遇到的问题,并提出了解决方案。

基于nRF24L01和Actel FPGA的智能探测系统设计

设计了基于nRF24L01无线数据传输芯片和Fusion StartKit开发板的智能探测系统。通过开启nRF24L01的ACK PAYLOAD功能实现车载系统与上位机之间的双向通信,采用Actel公司带有APB3总线的8051S软核在Fusion StartKit开发板上构建片上系统,使用MFC编写Windows环境下的人机交互界面,实现了具有实时数据传送、自动避障、远程操控等功能的智能探测系统。

Data Analysis of Chang'E-1 Gamma-Ray Spectrometer and Global Distribution of U,K,and Th Elemental Abundances

Gamma-ray spectrometer （GRS） is one of the main payloads on the Chang＇E-1 （CE-1） lunar probe, mainly aimed to detect the elemental abundances and distributions on the lunar surface. At 03：58 on 28 November 2007, it performed the first observation of the lunar gamma rays. As of 24 October 2008, 2105 h of effective gamma rays spectra had been acquired by CE-1 GRS, which covers the whole surface of the moon. This paper mainly describes the data processing procedures and methods of deriving the elemental abundances by using the CE-1 GRS time series corrected spectra： first, to bin data into pixels for mapping; then, to perform a background deduction of the cumulative spectra and obtain a peak area of the elements; and finally, to use the elemental abundances inversion model to produce the elemental abundances. Based on these processing methods, the global abundance maps of U, K, and Th at a 5°×5° equal-area pixel are acquired by CE-1 GRS data. The paper gives a preliminary analysis of the uncertainties of the elemental abundances.

Overview of the Latest Scientific Results of China’s Lunar Exploration Program

China’s Chang’E-4 probe successfully landed on 3 January 2019 in Von Kármán crater within the South Pole-Aitken(SPA)basin on the lunar far side.Based on the data acquired by the scientific payloads onboard the lander and the rover,the researchers obtained the related information such as the geologic and tectonic setting of the landing area,compositional characteristics of the landing surface materials,dielectric permittivity and density of the lunar soil.The experiments confirmed the existence of materials dominated by olivine and low-calcium pyroxene in the SPA basin on the lunar far side,which preliminary revealed the geological evolution history of the SPA basin and even that of the early time lunar crust,as well as the tectonic setting and formation mechanism of the materials in the lunar interior.The researchers also investigated the particle radiation,Linear Energy Transaction(LET)spectrum,and so forth on the lunar surface.The low-frequency radio observations were carried out on the lunar far side for the first time as well.This article summarizes the latest scientific results in the past years,focusing on the Chang’E-4 mission.

基于PayLoad特征的P2P IPTV应用识别

近年来,基于P2P流媒体技术的网络电视已经成为网络舆论传播的重要手段之一,而P2P技术的无中心和自组织特性将大大增加对网络电视服务进行识别和监管的难度。本文首先通过对不同IPTV的payload数据分析,发现P2PIPTV系统通信过程中均存在访问地址特征、协议定义特征以及数据传输特征,然后提出了基于以上三种特征相结合的识别方法,并设计实现了实时识别系统,最后利用统计实验验证了系统的识别精度并对实验进行了分析。

基于IP网络MPEG-4视频优化打包模型的研究

在当前网络是尽力而为的模式下,最终用户得到的视频质量是不好的。文章提出了一个基于IP网络上的MPEG-4视频包优化(Packetization)方案。所设计的算法是考虑SL分组的大小,对一个或多个SL流复用,所形成的FlexMux流完整的作为RTP包荷载。仿真结果表明,该算法所产生的包数量相对较少,降低了包之间的互关联性,体现了网络对视频传输的要求。

LinuxBIOS在嵌入式x86系统中的配置

基于x86平台的嵌入式计算机还依赖于传统的BIOS,给开发者灵活开发嵌入式计算机软硬件带来困难;LinuxBIOS是能够取代传统BIOS的开源解决方案。本文对LinuxBIOS的基本结构、运行过程以及配置ROM映像进行了研究,并给出在基于Geode LX处理器的x86嵌入式平台上LinuxBIOS映像配置的方法,对嵌入式开发人员具有一定的借鉴意义。

Current Status and Main Scientific Outcomes of the CSES Mission

This report briefly introduces the current status of the CSES(China Seismo-Electromagnetic Satellite)mission which includes the first satellite CSES 01 in-orbit(launched in February 2018),and the second satellite CSES 02(will be launched in 2023)under development.The CSES 01 has been steadily operating in orbit for over four years,providing abundant global geophysical field data,including the background geomagnetic field,the electromagnetic field and wave,the plasma(in-situ and profile data),and the energetic particles in the ionosphere.The CSES 01 platform and the scientific instruments generally perform well.The data validation and calibration are vital for CSES 01,for it aims to monitor earthquakes by extracting the very weak seismic precursors from a relatively disturbing space electromagnetic environment.For this purpose,we are paying specific efforts to validate data quality comprehensively.From the CSES 01 observations,we have obtained many scientific results on the ionosphere electromagnetic environment,the seismo-ionospheric disturbance phenomena,the space weather process,and the Lithosphere-Atmosphere-Ionosphere coupling mechanism.

Multiple Images Steganography of JPEG Images Based on Optimal Payload Distribution

Multiple images steganography refers to hiding secret messages in multiple natural images to minimize the leakage of secret messages during transmission.Currently,the main multiple images steganography algorithms mainly distribute the payloads as sparsely as possible inmultiple cover images to improve the detection error rate of stego images.In order to enable the payloads to be accurately and efficiently distributed in each cover image,this paper proposes a multiple images steganography for JPEG images based on optimal payload redistribution.Firstly,the algorithm uses the principle of dynamic programming to redistribute the payloads of the cover images to reduce the time required in the process of payloads distribution.Then,by reducing the difference between the features of the cover images and the stego images to increase the detection error rate of the stego images.Secondly,this paper uses a data decomposition mechanism based on Vandermonde matrix.Even if part of the data is lost during the transmission of the secret messages,as long as the data loss rate is less than the data redundancy rate,the original secret messages can be recovered.Experimental results show that the method proposed in this paper improves the efficiency of payloads distribution compared with existing multiple images steganography.At the same time,the algorithm can achieve the optimal payload distribution of multiple images steganography to improve the anti-statistical detection performance of stego images.