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Article
Publication date: 4 April 2022

Yuxia Ji, Li Chen, Jun Zhang, Dexin Zhang and Xiaowei Shao

The purpose of this paper is to investigate the pose control of rigid spacecraft subject to dead-zone input, unknown external disturbance and parametric uncertainty in space…

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Abstract

Purpose

The purpose of this paper is to investigate the pose control of rigid spacecraft subject to dead-zone input, unknown external disturbance and parametric uncertainty in space maneuvering mission.

Design/methodology/approach

First, a 6-Degree of Freedom (DOF) dynamic model of rigid spacecraft with dead-zone input, unknown external disturbances and parametric uncertainty is derived. Second, a super-twisting-like fixed-time disturbance observer (FTDO) with strong robustness is developed to estimate the lumped disturbances in fixed time. Based on the proposed observer, a non-singular fixed-time terminal sliding-mode (NFTSM) controller with superior performance is proposed.

Findings

Different from the existing sliding-mode controllers, the proposed control scheme can directly avoid the singularity in the controller design and speed up the convergence rate with improved control accuracy. Moreover, no prior knowledge of lumped disturbances’ upper bound and its first derivatives is required. The fixed-time stability of the entire closed-loop system is rigorously proved in the Lyapunov framework. Finally, the effectiveness and superiority of the proposed control scheme are proved by comparison with existing approaches.

Research limitations/implications

The proposed NFTSM controller can merely be applied to a specific type of spacecrafts, as the relevant system states should be measurable.

Practical implications

A NFTSM controller based on a super-twisting-like FTDO can efficiently deal with dead-zone input, unknown external disturbance and parametric uncertainty for spacecraft pose control.

Originality/value

This investigation uses NFTSM control and super-twisting-like FTDO to achieve spacecraft pose control subject to dead-zone input, unknown external disturbance and parametric uncertainty.

Details

Aircraft Engineering and Aerospace Technology, vol. 94 no. 8
Type: Research Article
ISSN: 1748-8842

Keywords

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Article
Publication date: 1 July 2006

Xuejing Li

This purpose of this paper is to describe the course of information literacy given by the Chongqing University library to cultivate university students' information awareness…

1148

Abstract

Purpose

This purpose of this paper is to describe the course of information literacy given by the Chongqing University library to cultivate university students' information awareness. Up‐to‐date information retrieval skills, comprehensive document skills and innovative thinking are encouraged.

Design/methodology/approach

Adopts a range of innovative teaching/learning methodologies using modern teaching methods and materials; and combines these with scientific and technical consultation and patent agent cases. Describes how this course has been brought into the university undergraduate and graduate teaching plan.

Findings

The utilization rates for documents and resources in the library have improved; and many other social benefits have been achieved.

Originality/value

Will guide others wishing to set up an information literacy education course and enhance the information literacy of university students.

Details

Library Management, vol. 27 no. 6/7
Type: Research Article
ISSN: 0143-5124

Keywords

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Article
Publication date: 7 October 2014

Martin Aruldoss, Miranda Lakshmi Travis and V. Prasanna Venkatesan

Business intelligence (BI) has been applied in various domains to take better decisions and it provides different level of information to its stakeholders according to the…

5781

Abstract

Purpose

Business intelligence (BI) has been applied in various domains to take better decisions and it provides different level of information to its stakeholders according to the information needs. The purpose of this paper is to present a literature review on recent works in BI. The two principal aims in this survey are to identify areas lacking in recent research, thereby offering potential opportunities for investigation.

Design/methodology/approach

To simplify the study on BI literature, it is segregated into seven categories according to the usage. Each category of work is analyzed using parameters such as purpose, domain, problem identified, solution applied, benefit and outcome.

Findings

The BI contribution in various domains, ongoing research in BI, the convergence of BI domains, problems and solutions, results of congregated domains, core problems and key solutions. It also outlines BI and its components composition, widely applied BI solutions such as algorithm-based, architecture-based and model-based solutions. Finally, it discusses BI implementation issues and outlines the security and privacy policies adopted in BI environment.

Research limitations/implications

In this survey BI has been discussed in theoretical perspective whereas practical contribution has been given less attention.

Originality/value

A comprehensive survey on BI which identifies areas lacking in recent research and providing potential opportunities for investigation.

Details

Journal of Enterprise Information Management, vol. 27 no. 6
Type: Research Article
ISSN: 1741-0398

Keywords

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