Blockchain, the foundation of Bitcoin, has received extensive attentions recently. Blockchain serves as an immutable ledger which allows transactions take place in a decentralized manner. Blockchain-based applications are springing up, covering numerous fields including financial services, reputation system and Internet of Things (IoT), and so on. However, there are still many challenges of blockchain technology such as scalability and security problems waiting to be overcome. This paper presents a comprehensive overview on blockchain technology. We provide an overview of blockchain architechture firstly and compare some typical consensus algorithms used in different blockchains. Furthermore, technical challenges and recent advances are briefly listed. We also lay out possible future trends for blockchain.

An Overview of Blockchain Technology: Architecture, Consensus, and Future Trends

The rate-distortion efficiency of video compression schemes is based on a sophisticated interaction between various motion representation possibilities, waveform coding of differences, and waveform coding of various refreshed regions. Hence, a key problem in high-compression video coding is the operational control of the encoder. This problem is compounded by the widely varying content and motion found in typical video sequences, necessitating the selection between different representation possibilities with varying rate-distortion efficiency. This article addresses the problem of video encoder optimization and discusses its consequences on the compression architecture of the overall coding system. Based on the well-known hybrid video coding structure, Lagrangian optimization techniques are presented that try to answer the question: what part of the video signal should be coded using what method and parameter settings?.

Rate-distortion optimization for video compression

Blockchain has numerous benefits such as decentralisation, persistency, anonymity and auditability. There is a wide spectrum of blockchain applications ranging from cryptocurrency, financial services, risk management, internet of things (IoT) to public and social services. Although a number of studies focus on using the blockchain technology in various application aspects, there is no comprehensive survey on the blockchain technology in both technological and application perspectives. To fill this gap, we conduct a comprehensive survey on the blockchain technology. In particular, this paper gives the blockchain taxonomy, introduces typical blockchain consensus algorithms, reviews blockchain applications and discusses technical challenges as well as recent advances in tackling the challenges. Moreover, this paper also points out the future directions in the blockchain technology.

Blockchain challenges and opportunities: a survey

IoT security: Review, blockchain solutions, and open challenges

Blockchain is a decentralized transaction and data management technology developed first for Bitcoin cryptocurrency. The interest in Blockchain technology has been increasing since the idea was coined in 2008. The reason for the interest in Blockchain is its central attributes that provide security, anonymity and data integrity without any third party organization in control of the transactions, and therefore it creates interesting research areas, especially from the perspective of technical challenges and limitations. In this research, we have conducted a systematic mapping study with the goal of collecting all relevant research on Blockchain technology. Our objective is to understand the current research topics, challenges and future directions regarding Blockchain technology from the technical perspective. We have extracted 41 primary papers from scientific databases. The results show that focus in over 80% of the papers is on Bitcoin system and less than 20% deals with other Blockchain applications including e.g. smart contracts and licensing. The majority of research is focusing on revealing and improving limitations of Blockchain from privacy and security perspectives, but many of the proposed solutions lack concrete evaluation on their effectiveness. Many other Blockchain scalability related challenges including throughput and latency have been left unstudied. On the basis of this study, recommendations on future research directions are provided for researchers.

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Where Is Current Research on Blockchain Technology?-A Systematic Review.

Nowadays, the development of traditional business models become more and more mature that people use them to guide various kinds of E-business activities. Internet of things (IoT), being an innovative revolution over the Internet, becomes a new platform for E-business. However, old business models could hardly fit for the E-business on the IoT. In this article, we 1) propose an IoT E-business model, which is specially designed for the IoT E-business; 2) redesign many elements in traditional E-business models; 3) realize the transaction of smart property and paid data on the IoT with the help of P2P trade based on the Blockchain and smart contract. We also experiment our design and make a comprehensive discuss.

The IoT electric business model: Using blockchain technology for the internet of things

We describe a novel and effective video enhancement algorithm for low lighting video. The algorithm works by first inverting an input low-lighting video and then applying an optimized image de-haze algorithm on the inverted video. To facilitate faster computation, temporal correlations between subsequent frames are utilized to expedite the calculation of key algorithm parameters. Simulation results show excellent enhancement results and 4x speed up as compared with the frame-wise enhancement algorithms.

Fast efficient algorithm for enhancement of low lighting video

We introduce new methods of performing selective encryption and spatial/frequency shuffling of compressed digital content that maintain syntax compliance after content has been secured. The tools described have been proposed to the MPEG-4 Intellectual Property Management and Protection (IPMP) standardization group and have been adopted into the MPEG-4 IPMP Final Proposed Draft Amendment (FPDAM). We describe the application of the new methods to the protection of MPEG-4 video content in the wireless environment, and illustrate how they are used to leverage established encryption algorithms for the protection of only the information fields in the bitstream that are critical to the reconstructed video quality, while maintaining compliance to the syntax of MPEG-4 video, and thereby reduces the amount of data to be encrypted and guarantees the inheritance of many of the good properties of the unprotected bitstreams that have been carefully studied and built, such as error resiliency and network friendliness. The encrypted content bitstream works with many existing random access, network bandwidth adaptation, and error control techniques that have been developed for standard-compliant compressed video, thus making it especially suitable for wireless multimedia applications. Standard compliance also allows subsequent signal processing techniques to be applied to the encrypted bitstream.

A format-compliant configurable encryption framework for access control of video

Nowadays, the development of traditional business models become more and more mature that people use them to guide various kinds of E-business activities. Internet of things(IoT), being an innovative revolution over the Internet, becomes a new platform for E-business. However, old business models could hardly fit for the E-business on the IoT. In this article, we 1) propose an IoT E-business model, which is specially designed for the IoT E-business; 2) redesign many elements in traditional E-business models; 3) realize the transaction of smart property and paid data on the IoT with the help of P2P trade based on the Blockchain and smart contract. We also experiment our design and make a comprehensive discuss.

An IoT electric business model based on the protocol of bitcoin

We describe a novel and effective video enhancement algorithm for low lighting video. The algorithm works by first inverting the input low-lighting video and then applying an image de-haze algorithm on the inverted input. To facilitate faster computation and improve temporal consistency, correlations between temporally neighboring frames are utilized. Simulations using naive implementations of the algorithm show good enhancement results and 2x speed-up as compared with frame-wise enhancement algorithms, with further improvements in both quality and speed possible.

http://media.cs.tsinghua.edu.cn/~luyao/papers/icme.pdf

Jiangtao Wen

Papers

The IoT electric business model: Using blockchain technology for the internet of things

Fast efficient algorithm for enhancement of low lighting video

A format-compliant configurable encryption framework for access control of video

An IoT electric business model based on the protocol of bitcoin

Fast efficient algorithm for enhancement of low lighting video