The sea has been manifested to cause the emotion of fear to people when it comes to a very depth, especially to those who have thalassophobia. Many people have to work in the sea while nearly no research on influence of fear of the sea to cognition has been carried out. This study explores the impact of fear of the sea induced by immersive virtual reality on working memory which is a cognitive system with a limited capacity. Participants were required to complete n-back working memory task of three difficulty levels in the non-emotional environment and the undersea environment respectively by means of virtual reality. Pupil diameter changes were recorded along with the task performance. In addition to reaction times and accuracy (correctly press a button in response to targets) as two task performance indices used in most researches, the commission errors (incorrectly press a button in response to non-targets) and omission errors (incorrectly do not press a button in response to targets) were also differentiated herein. The results of the study indicated that the virtual undersea environment did induce the emotion of fear. As for the task performance, except that the performance of low-level task did not differ much between the two environments, the fear of the sea increased the accuracy of the medium level n-back task but decreased it of high-level n-back task. Result of omission errors was just the opposite and commission errors were increased in both levels of task. The findings, including the positive role of a moderate level of fear of the sea in the performance of working memory task, make a lot of sense for future cognitive work in the sea.

Blockchain has attracted great attention as the basis of cryptocurrencies such as Bitcoin, but its capabilities extend far beyond that. Blockchain has the potential to revolutionize applications because it provides a transparent, immutable, and append-only ledger that can be used to build new decentralized applications. However, it is hard to implement changes to Bitcoin without forking blockchain. As a result, Bitcoin has difficulty in adapting to new demands and extending new functionality. The traditional way to introduce new functionality is to modify Bitcoin's code base, but which will lead to some problems such as (a) the security of blockchains, (b) the allocation of currency, and (c) the waste of resources. We present a novel design, statechain, which uses Bitcoin blockchain to propagate application log. It can add new functionality without requiring blockchain fork changes from Bitcoin. Statechain enables application nodes to efficiently query the log as well as transfer log between blockchains. We detail how the application nodes achieve application-level consensus at each block. As far as we know, this technology has not been exploited. However, it has a great practical significance that enables the introduction of new functionality safer and makes the development of blockchain-based applications easier. We have used statechain to explore the field of transferring bitcoins and other cryptocurrencies directly between multiple blockchains.

Lists are one of the most fundamental and ubiquitous data structures. A self-organizing list can adjust the structure according to the request sequence to improve average access time. However, it is a challenge to obtain a practical concurrent self-organizing linked-list with lock-free property, which guarantees that some operation finishes when any thread executes a finite number of steps. This paper implements a novel lock-free self-organizing list whose items are moved to the front when being requested. The implementation uses a new log method and a new help mechanism. The log consists of operation nodes which record the execution history. Friend chains are formed during list traversal to help related operations. This paper also introduces a speed-up variation which is more pragmatic. Furthermore, this paper presents a comprehensive evaluation in experiments on non-uniform data set. Experiment demonstrates the advantages of the new linked-lists among other algorithms in throughput and scalability. On requests derived from real workloads, it achieves 22% to 184% speedup than the existing concurrent lists.

This paper presents nonblocking hash table algorithms that support resizing in both directions: shrinking and growing. The heart of the table is a freezable set abstraction, which greatly simplifies the task of moving elements among buckets during a resize. Furthermore, the freezable set abstraction makes possible the use of highly optimized implementations of individual buckets, including implementations in which a single flat array is used for each bucket, which improves cache locality.

Self-organizing linked lists perform well for handling requests with strong locality. Non-blocking shared data structures are robust and reliable. We present the first non-blocking self-organizing linked list algorithm which supports linearizable search, insert and remove operations. The experimental results show that our algorithm performs well for long linked lists with high percentages of search operations.