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Aquifer and Tracer Tests
Published in William C. Walton, Principles of GROUNDWATER ENGINEERING, 2020
Data manipulation including drawdown adjustment may be facilitated with a microcomputer general purpose database management system such as REFLEX (trademark of Borland International, Inc.). This software allows users to view data in several ways: in single record form, in lists, in graphs, and in cross tabulations. REFLEX provides an unusually large area to design a form on the screen and offers convenient editing commands including the ability to move the cursor left or right five characters at a time. Records may be statistically analyzed, sorted, and filtered. For example, fields (water level data and adjustments) may be added or subtracted to determine record (time) drawdown totals (Ericson and Moskol, 1986). REFLEX sorts up to five fields at once and provides a large number of arithmetic, date, and logic functions. The software groups and subtotals information and displays a graph next to a database list. REFLEX permits 250 fields, allows 254 characters per field and supports an IBM PC, XT, AT, or compatible, a variety of dot matrix printers, and plotters.
Design
Published in Miroslav Popovic, Communication Protocol Engineering, 2018
Obviously, a test case running on a test system must be able to communicate with a SUT in order to test it. Generally, TTCN-3 supports two types of communication among test cases and SUTs, namely message-based communication and procedure-based communication. Since message-based communication is still dominantly used, we focus on it in this book. Normally, we use the TTCN-3 type record to define needed message types. A record is an ordered structured type, which is a collection of basic type elements (such as integer and charstring) and other structured type elements that correspond to individual message fields. Many message types comprise a field that defines the kind of the message, and such a field is typically defined using the TTCN-3 type enumerated.
The central processing unit
Published in D.A. Bradley, N.C. Burd, D. Dawson, A.J. Loader, Mechatronics, 2018
D.A. Bradley, N.C. Burd, D. Dawson, A.J. Loader
Information is often stored and processed as tables or records of data. For example, a two-dimensional matrix would have to be stored as a linear array of numbers within the memory of a microprocessor system, with each row or column stored consecutively. Any processing performed on the matrix would then need to take account of this linearization. A convenient way of addressing individual elements within the matrix is to have a pointer to the start of the row or column together with an offset to address the element within the row or column. The required memory address is the sum of the start or base address and the offset. This technique of addressing a memory location according to a start or base address plus an offset is called indexed addressing.
Template-based knowledge reuse method for generating high-speed railway virtual construction scenes
Published in International Journal of Digital Earth, 2023
Heng Zhang, Wen Zhao, Zujie Han, Jun Zhu, Qing Zhu, Xinwen Ning, Dengke Fan, Hua Wang, Fengpin Jia, Wei Fang, Bin Yang, Weilian Li
Both the construction process knowledge base and the construction method knowledge base store knowledge in the form of frame animation. The frame animation is parsed, and the state of each feature in the 3D scene is changed according to a time sequence so that virtual construction is visualized. First, a mapping is established between the actual construction duration and the play duration of the frame animation. The frame animation is divided into multiple tracks, including a camera track, a model track, an annotation track, and an audio track. The camera track records the position, attitude, viewport, and orientation of a camera in the 3D scene. The model track records model growth actions, model skeleton joint actions, and model colors. The annotation track records information such as POIs by using text and images. The audio track records sound transformed from text by using an intelligent sound library. Finally, information fusion is performed between the four tracks so that a virtual construction animation is generated, as shown in Figure 8.
Evolutionary game analysis of collaborative transportation of emergency materials based on blockchain
Published in International Journal of Logistics Research and Applications, 2023
Blockchain technology is composed of a variety of technologies. Time-stamp technology records data storage time in detail, and asymmetric encryption technology ensures data storage is not tampered with. Smart contract technology ensures the spontaneous operation of the programme, and decentralisation technology ensures multi-party participation. Timely and efficient exchange of information among all participants in the materials transportation process can improve the efficiency of transportation and reduce the risk of virus infection. Logistics enterprises and charities participate in the alliance chain, and donors and materials-receiving centres participate in the public chain; thus, cross-chain access and fund flow can be realised between different participants. To protect privacy and information security, donors can donate funds directly to the blockchain platform. The materials management system based on the blockchain platform is illustrated in Figure 2.
Blockchain-based anonymous authentication for traffic reporting in VANETs
Published in Connection Science, 2022
Blockchain technology originated from a paper about bitcoin published by Nakamoto in 2009. Blockchain is a decentralised technology, which is essentially a type of special data structure. It can record and track transactions. As a distributed ledger, it packs all transactions into data blocks and combines blocks into a chronological chain. Each data block is mainly composed of block head and block body. The block header is used to record the metadata of the current block, which mainly encapsulates the current version number, the previous block hash, the target hash value and Merkle root of the current block, etc. The address of the previous block is used to connect the current block with the previous block to form a chain. The target hash value, random number and timestamp are used for consensus mechanism. The block body records data in the form of Merkle tree, the concrete data is recorded in the leaf nodes, non-leaf nodes storage the hash value of sub-nodes instead of specific data, which reduces the block capacity and facilitates synchronisation and backup. The Merkle root save the ultimate hash value of all records in the block body. A slight modification of a record in leaf node would lead to the complete change of hash value in the root node. This data storage mechanism achieves the fast query and verification on records. The application of cryptographic method in chain structure ensures that the data in the blockchain cannot be tampered under the public and fully open environment.