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Recently, decentralized file systems are widely used to overcome centralized file systems' load asymmetry between nodes and the scalability problem. Due to the lack of a metadata server, decentralized systems require more RPC requests to control metadata processing between clients and servers, which adversely impacts the I/O performance and traffic imbalance by increasing RPC latency. In this paper, we propose an efficient I/O scheme to reduce the RPC overhead in decentralized file systems. Instead of sending a single RPC request at a time, we enqueued the RPCs in the global queue and merged them into larger RPC requests, thus avoiding excessive RPC latency overheads. The experimental results showed that our scheme improves write and read performance by up to 13% and 16%, respectively, compared with those of the original. [ABSTRACT FROM AUTHOR]

Existing nonvolatile memory (NVM)-based file systems can fully leverage the characteristics of NVM to obtain better performance than traditional disk-based file systems. It has the potential capacity to efficiently manage metadata and perform fast metadata operations. However, most NVM-based file systems mainly focus on managing file metadata (inode), while pay little attention to directory metadata (dentry), which also has a noticeable impact on the file system performance. Besides, the traditional journaling technique that guarantees metadata consistency may not yield satisfactory performance on NVM-based file systems. To solve these problems, in this article we propose a fast and low overhead metadata operation mechanism, called FLOMO. It first adopts a novel slotted-paging structure in NVM to reorganize dentry for efficiently performing dentry operations, and utilizes the red–black tree in DRAM to accelerate dentry lookup and the search process of dentry deletion. Moreover, FLOMO presents a selective journaling scheme for metadata updates, which partially logs the changes related to dentry in the proposed slotted page, thereby, mitigating the redundant journaling overhead. To verify FLOMO, we implement it in a typical NVM-based file system, the persistent memory file system (PMFS). Experimental results show that FLOMO accelerates the metadata operations in PMFS by 34.4% $\sim 59$ %, and notably reduces the journaling overhead for metadata, shortening the latency by 59% on average. For real-world applications, FLOMO has higher throughput compared with PMFS, PMFS without journal, and NOVA, achieving up to $2.1\times $ , $1.1\times $ , and $1.3\times $ performance improvement, respectively. [ABSTRACT FROM AUTHOR]

Sharing scientific data is an effective means to rationally exploit scientific data and is vital to promote the development of the industrial chain and improve the level of science and technology. In recent years, the popularity of the open data platform has increased, but problems remain, including imperfect system architecture, unsound privacy and security, and non-standardized interaction data. To address these problems, the blockchain's decentralization, smart contracts, distributed storage, and other features can be used as the core technology for open data systems. This paper addresses the problems of opening, allocation-right confirmation, sharing, and rational use of wild-bird data from Yunnan Province, China. A data storage model is proposed based on the blockchain and interstellar file system and is applied to wild-bird data to overcome the mutual distrust between ornithology institutions in the collaborative processing and data storage of bird data. The model provides secure storage and secure access control of bird data in the cloud, thereby ensuring the decentralized and secure storage of wild-bird data for multiple research institutions. [ABSTRACT FROM AUTHOR]

In this article, the author offers suggestions for writing a cover letter for an academic position. It mentions cover letter as a genre of academic writing means recognizing that it presents an opportunity to make an argument and cover letters show that the applicant has considered the needs of the hiring institution. It also mentions tempting to take a cover letter off the shelf and out of the electronic files.

Cloud computing plays a significant role in effective data handling based on the increase in data usage in various realtime applications. Data auditing is performed on certain files and the authenticator with deduplication. It addresses the problem of key management to deduce the file content based on the malicious activities performed on the cloud. So, based on effective auditing of the integrity of the data and authenticator, the data is checked properly and minimizes the overhead of cloud storage overhead. In this work, the cloud audit and authenticator approach is proposed based on a certain file system, which makes the malicious user get authenticate the data auditing verification as the existing algorithm has low security based on entropy. They propose a data auditing approach that integrates with file management and the authenticator of data deduplication. The proposed approach performs the authenticator process and new form of file tag, which helps guarantee effective security based on the random generation of message key. The proposed approach achieves minimum computational overhead based on the authenticator and data block generation in the performance analysis. Then the security verification is performed on various attacks, such as brute force attack, a man-in-the-middle attack, etc., to check whether the approach is safe or unsafe against the attacks. [ABSTRACT FROM AUTHOR]

In file systems, a single write system call can make multiple modifications to data and metadata, but such changes are not flushed in an atomic way. To retain the consistency of file systems, conventional approaches guarantee crash consistency in exchange for sacrificing system performance. To mitigate the performance penalty, non-volatile memory (NVM) technologies are believed to be a good candidate for this purpose owing to their low latency and byte-addressibility. However, none of the prior proposals that exploit NVM provide both scalability and strict ordering of modifications. In this article, we propose montage, a crash consistency framework for file systems that consists of two parts. First, montage splits NVM space into multiple staging areas and synchronizes the flushing of modifications these to the storage device. Second, montage uses the pipelined architecture to speed up data flushing to storage. We apply montage to two journaling file systems (ext4 and JFS) and evaluate them on a multicore server with high-performance storage. The evaluation results demonstrate that our design exhibits better performance by a wide margin than recent NVM-based journaling file systems. [ABSTRACT FROM AUTHOR]

Throughout the ages, safely preserving and transmitting data that have extraordinary importance for humanity has increased its importance with rapid advances in computer technology. Steganography stores hidden data within the files, which are unnoticed by third parties, so it provides secure transmission of data to the receiver. In this study, a steganography-based GUI design has been carried out, which ensures that the agricultural data is safely stored and communicated to the other party. We used LSB one-bit, two-bit, three-bit substitution and PVD algorithms with GUI for stages of agricultural data hiding and extracting at cover images. We also provided extra security using the embedded key and shifting operations on the hidden data before hiding data the cover image. In short, we confused the hidden data in the cover image so that malicious people can't understand. In experimental studies, performance analysis was evaluated by comparing various criteria as similarity ratio (Structural Similarity Index Measure, SSIM), stego image quality (Peak Signal-to-Noise Ratio, PSNR) and data hiding capacity (Payload). [ABSTRACT FROM AUTHOR]

The IEEE P2731 working group is in the process of developing a functional model so that virtually any BCI system could be described according to it. In this paper, we want to stimulate the discussion for the definition and selection of the information that should be stored in a file for effectively allowing the sharing of BCI data and tools amongst researchers. Establishing these requirements and procedures will accelerate BCI development and lay the foundation for accessible and scalable BCI technology as well as provide the foundations for the definition of a standard file format. [ABSTRACT FROM AUTHOR]

HDFS is a popular open-source system for scalable and reliable file management, which is designed as a general-purpose solution for distributed file storage. While it works well for medium or large files, it will suffer heavy performance degradations in case of lots of small files. To overcome this drawback, we propose here a system to enhance HDFS with a distributed true full-text search system SAES of 100% recall and precision ratios. By indexing the meta data of each file, e.g., name, size, date and description, files can be quickly accessed by efficient searches over metadata. Moreover, by merging many small files into a large file to be stored with better space and I/O efficiencies, the negative performance impacts caused by directly storing each small file individually are avoided. An experimental study is conducted for function and performance tests on both realistic and artificial data. The experimental results show that the system works well for file operations such as uploading, downloading and deleting. Moreover, the RAM consumption for managing massive small files is dramatically reduced, which is critical for good system performance. The proposed system could be a potential storage solution for massive small files. [ABSTRACT FROM AUTHOR]

Existing implementations of file systems often seem to be made on an ad hoc and implicit basis. This paper aims to enhance the organization of files and retrieval of files by modifying the traditional hierarchical file system to improve built-in query support and bulk metadata updates supported at the file system level. We introduce tags in a hierarchy of file collections and use links to allow file retrieval from multiple paths as files exist in multiple directories simultaneously. By using a series of modest changes to the hierarchical file system, we propose a novel Linked Tree Tags (LTTs) model. These changes include using multiple tags instead of names, collections instead of directories, exposing a query language at the Application Programming Interface (API) level, and allowing controlled file links. We assess our model's expressive capability and demonstrate that LTTs overcome traditional file systems' limits and provide users with the to manage their files easily. [ABSTRACT FROM AUTHOR]

Reverse engineering of file systems is indispensable for tool testing, accurate evidence acquisition, and correct interpretation of data structures by law enforcement in criminal investigations. This position paper examines emerging techno-legal challenges from the practice of reverse engineering for law enforcement purposes. We demonstrate that this new context creates uncertainties about the legality of tools and methods used for evidence acquisition and the compliance of law enforcement with obligations to protect intellectual property and confidential information. Further identified are gaps between legal provisions and practice related to disclosure and peer-review of sensitive digital forensic methodology, trade secrets in investigations, and governmental vulnerability disclosure. It is demonstrated that reverse engineering of file systems is insufficiently addressed by legislators, which results in a lack of file system interpretation and validation information for law enforcement and their dependence on tools. Outlined are recommendations for further developments of digital forensic regulation. [ABSTRACT FROM AUTHOR]

The Hashing process is an effective tool for handling large-scale data (for example, images, videos, or multi-model data) retrieval problems. To get better retrieval accuracy, hashing models usually are imposed with three rigorous constraints, i.e., discrete binary constraint, uncorrelated condition, and the balanced constraint, which will lead to being 'NP-hard'. In this study, we divide the whole constraints set into the uncorrelated (orthogonality) constraint and the binary discrete balance constraint and propose a fast and accurate penalty function semi-continuous thresholding (PFSCT) hash coding algorithm based on forward–backward algorithms. In addition, we theoretically analyze the equivalence between the relaxed model and the original problems. Extensive numerical experiments on diverse large-scale benchmark datasets demonstrate comparable performance and effectiveness of the proposed method. • A fast and accurate penalty function semi-continuous thresholding (PFSCT) hash coding algorithm based on forward–backward algorithms is established in the work, by dividing the whole constraints set into the uncorrelated (orthogonality) constraint and the binary discrete balance constraint. • We theoretically analyze the equivalence between the relaxed model and the original problems. • Extensive numerical experiments on diverse large-scale benchmark datasets, including Cifar10, NUS-WIDE and SUN397, demonstrate comparable performance and effectiveness of the proposed method. [ABSTRACT FROM AUTHOR]

Reverse engineering of file systems is indispensable for tool testing, accurate evidence acquisition, and correct interpretation of data structures by law enforcement in criminal investigations. This position paper examines emerging techno-legal challenges from the practice of reverse engineering for law enforcement purposes. We demonstrate that this new context creates uncertainties about the legality of tools and methods used for evidence acquisition and the compliance of law enforcement with obligations to protect intellectual property and confidential information. Further identified are gaps between legal provisions and practice related to disclosure and peer-review of sensitive digital forensic methodology, trade secrets in investigations, and governmental vulnerability disclosure. It is demonstrated that reverse engineering of file systems is insufficiently addressed by legislators, which results in a lack of file system interpretation and validation information for law enforcement and their dependence on tools. Outlined are recommendations for further developments of digital forensic regulation. [ABSTRACT FROM AUTHOR]