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Article
Publication date: 5 July 2021

Wang Jianhong

The purpose of this paper is to derive the output predictor for a stationary normal process with rational spectral density and linear stochastic discrete-time state-space model…

Abstract

Purpose

The purpose of this paper is to derive the output predictor for a stationary normal process with rational spectral density and linear stochastic discrete-time state-space model, respectively, as the output predictor is very important in model predictive control. The derivations are only dependent on matrix operations. Based on the output predictor, one quadratic programming problem is constructed to achieve the goal of subspace predictive control. Then an improved ellipsoid optimization algorithm is proposed to solve the optimal control input and the complexity analysis of this improved ellipsoid optimization algorithm is also given to complete the previous work. Finally, by the example of the helicopter, the efficiency of the proposed control strategy can be easily realized.

Design/methodology/approach

First, a stationary normal process with rational spectral density and one stochastic discrete-time state-space model is described. Second, the output predictors for these two forms are derived, respectively, and the derivation processes are dependent on the Diophantine equation and some basic matrix operations. Third, after inserting these two output predictors into the cost function of predictive control, the control input can be solved by using the improved ellipsoid optimization algorithm and the complexity analysis corresponding to this improved ellipsoid optimization algorithm is also provided.

Findings

Subspace predictive control can not only enable automatically tune the parameters in predictive control but also avoids many steps in classical linear Gaussian control. It means that subspace predictive control is independent of any prior knowledge of the controller. An improved ellipsoid optimization algorithm is used to solve the optimal control input and the complexity analysis of this algorithm is also given.

Originality/value

To the best knowledge of the authors, this is the first attempt at deriving the output predictors for stationary normal processes with rational spectral density and one stochastic discrete-time state-space model. Then, the derivation processes are dependent on the Diophantine equation and some basic matrix operations. The complexity analysis corresponding to this improved ellipsoid optimization algorithm is analyzed.

Details

Aircraft Engineering and Aerospace Technology, vol. 93 no. 5
Type: Research Article
ISSN: 1748-8842

Keywords

Article
Publication date: 5 October 2012

Assefa Semegn and Eamonn Murphy

The purpose of this paper is to introduce a novel approach of designing, specifying, and describing the behavior of software systems in a way that helps to predict their…

Abstract

Purpose

The purpose of this paper is to introduce a novel approach of designing, specifying, and describing the behavior of software systems in a way that helps to predict their reliability from the reliability of the components and their interactions.

Design/methodology/approach

Design imperatives and relevant mathematical documentation techniques for improved reliability predictability of software systems are identified.

Findings

The design approach, which is named design for reliability predictability (DRP), integrates design for change, precise behavioral documentation and structure based reliability prediction to achieve improved reliability predictability of software systems. The specification and documentation approach builds upon precise behavioral specification of interfaces using the trace function method (TFM) and introduces a number of structure functions or connection documents. These functions capture both the static and dynamic behavior of component‐based software systems and are used as a basis for a novel document driven structure based reliability predication model.

Originality/value

Decades of research effort have been spent in software design, mathematical/formal specification and description and reliability prediction of software systems. However, there has been little convergence among these three areas. This paper brings a new direction where the three research areas are unified to create a new design paradigm.

Details

International Journal of Quality & Reliability Management, vol. 29 no. 9
Type: Research Article
ISSN: 0265-671X

Keywords

Book part
Publication date: 1 December 2016

Yuxue Sheng and James P. LeSage

We are interested in modeling the impact of spatial and interindustry dependence on firm-level innovation of Chinese firms The existence of network ties between cities imply that…

Abstract

We are interested in modeling the impact of spatial and interindustry dependence on firm-level innovation of Chinese firms The existence of network ties between cities imply that changes taking place in one city could influence innovation by firms in nearby cities (local spatial spillovers), or set in motion a series of spatial diffusion and feedback impacts across multiple cities (global spatial spillovers). We use the term local spatial spillovers to reflect a scenario where only immediately neighboring cities are impacted, whereas the term global spatial spillovers represent a situation where impacts fall on neighboring cities, as well as higher order neighbors (neighbors to the neighboring cities, neighbors to the neighbors of the neighbors, and so on). Global spatial spillovers also involve feedback impacts from neighboring cities, and imply the existence of a wider diffusion of impacts over space (higher order neighbors).

Similarly, the existence of national interindustry input-output ties implies that changes occurring in one industry could influence innovation by firms operating in directly related industries (local interindustry spillovers), or set in motion a series of in interindustry diffusion and feedback impacts across multiple industries (global interindustry spillovers).

Typical linear models of firm-level innovation based on knowledge production functions would rely on city- and industry-specific fixed effects to allow for differences in the level of innovation by firms located in different cities and operating in different industries. This approach however ignores the fact that, spatial dependence between cities and interindustry dependence arising from input-output relationships, may imply interaction, not simply heterogeneity across cities and industries.

We construct a Bayesian hierarchical model that allows for both city- and industry-level interaction (global spillovers) and subsumes other innovation scenarios such as: (1) heterogeneity that implies level differences (fixed effects) and (2) contextual effects that imply local spillovers as special cases.

Details

Spatial Econometrics: Qualitative and Limited Dependent Variables
Type: Book
ISBN: 978-1-78560-986-2

Keywords

Article
Publication date: 1 December 2001

Graham J. Treloar, Peter E.D. Love and Olusegun O. Faniran

Embodied energy is the total amount of energy required to produce a product, and is significant because it occurs immediately and can be equal over the life cycle of a building to…

1698

Abstract

Embodied energy is the total amount of energy required to produce a product, and is significant because it occurs immediately and can be equal over the life cycle of a building to the transient requirements for operational energy. Methods for embodied energy analysis include process analysis, inputoutput analysis and hybrid analysis. Proposes to improve the reliability of estimating embodied energy based on inputoutput models by using an algorithm to extract systematically the most important energy paths for the “other construction” sector from an Australian inputoutput model. Demonstrates the application of these energy paths to the embodied energy analysis of an individual commercial building, highlighting improvements in reliability due to the modification of energy paths with process analysis data. Compares materials and elements for the building, and estimates likely ranges of error.

Details

Logistics Information Management, vol. 14 no. 5/6
Type: Research Article
ISSN: 0957-6053

Keywords

Article
Publication date: 1 January 1978

VICTOR BULMER‐THOMAS

There has been very little written discussion of how transactions should be valued in an inputoutput table. Conventional wisdom, however, prefers the use of ‘basic’ prices (in…

Abstract

There has been very little written discussion of how transactions should be valued in an inputoutput table. Conventional wisdom, however, prefers the use of ‘basic’ prices (in which flows are valued net of distributive margins and net indirect taxes) and the first part of this paper explores the reasoning behind this approach.

Details

Journal of Economic Studies, vol. 5 no. 1
Type: Research Article
ISSN: 0144-3585

Article
Publication date: 6 June 2016

J.M. Albala-Bertrand

The aim of this paper is to learn about some patterns of sectoral and industrial structural change of the Chinese economy over the 1995-2010 period, which also complements a…

Abstract

Purpose

The aim of this paper is to learn about some patterns of sectoral and industrial structural change of the Chinese economy over the 1995-2010 period, which also complements a previous paper of the author. The chosen period is about (and conveniently) bounded by two international crises: the Southeast Asian crisis of 1997 and the world crisis that started in 2007/2008.

Design/methodology/approach

To such a purpose, this paper set up a quantitative methodology via input-output modelling, which allows us to decompose gross output into some key demand sources or contributions. These are then analyzed over the full period.

Findings

It can be shown that the trajectory of the main structural patterns over the period was not smooth and was pretty unbalanced and that they generally responded to both domestic policy and international shocks. Export demand and heavy industry appeared to be the main engines of the economy, which showed massive increases in their share of output, at the expense of domestic demand, services and agriculture. Despite the high growth rates over this period, the Chinese economy seemed to be in need of rebalancing, which seems to have started toward the end of the authors’ period.

Originality/value

The decomposition method has been applied before by the author and others, but the variations in this paper are original, just as original is the application to China (never been done before), which in addition is not confined to two or so snapshots separated by many years, as is the usual use, but to the full year-after-year change of the sectoral and industrial structure over this study’s focus period.

Details

Journal of Chinese Economic and Foreign Trade Studies, vol. 9 no. 2
Type: Research Article
ISSN: 1754-4408

Keywords

Article
Publication date: 16 October 2009

Manuel De la Sen

The purpose of this paper is to discuss the properties of transparency and excitability of positive linear time‐invariant systems under internal point delays.

Abstract

Purpose

The purpose of this paper is to discuss the properties of transparency and excitability of positive linear time‐invariant systems under internal point delays.

Design/methodology/approach

The problem is solved by combining the algebraic conditions for positivity, excitability, and transparency for the case of linear and time‐invariant dynamic systems in the presence of discrete lags.

Findings

It is shown that the excitability independent of delay is guaranteed if an auxiliary delay‐free system is excitable. Necessary and sufficient conditions for excitability and transparency are formulated in terms of the parameterization of the dynamics and control matrices, and equivalently, in terms of strict positivity of a matrix of an associate system obtained from the influence graph of the original system. Such conditions are testable through simple algebraic tests involving moderate computational effort.

Practical implications

The practical implications mainly rely on some biological and medical problems where delays are present by nature, excitability means the activation of all the state components under positive controls after a short time in the sense that it cannot remain identically zero. In the same way, it relays on the activation of all the output components under zero controls and non‐negative initial conditions.

Originality/value

The paper extends the concepts of excitability and transparency to dynamic systems with point time‐lags which are very common in nature and some practical problems.

Details

Kybernetes, vol. 38 no. 9
Type: Research Article
ISSN: 0368-492X

Keywords

Article
Publication date: 8 July 2014

Eduardo A. Haddad, Weslem R. Faria and Joaquim J.M. Guilhoto

– The purpose of this paper is to look at the interplay of technology and social preferences in different stages of economic development.

291

Abstract

Purpose

The purpose of this paper is to look at the interplay of technology and social preferences in different stages of economic development.

Design/methodology/approach

The authors use a set of input-output tables for 32 different countries, published by OECD. The tables refer to the period 1996-2001 and were consolidated in 48 sectors so that structural comparisons were possible through the use of techniques of decomposition used for comparing different economic structures in the context of partitioned input-output systems.

Findings

The authors confirm that, for different levels of per capita GDP, technological change is an important element to drive growth. However, as an economy evolves, the data set also confirm that the composition of final demand, which reveals social preferences in a static way, moves away from agricultural and manufacturing to services activities. Such structural changes favor sectors with stronger value added multipliers, and stronger complexity found in higher income countries generates a force that helps driving income divergence.

Research limitations/implications

Given the chosen methodological approach, the structural features revealed in this study remain to be empirically tested in growth models.

Practical implications

The paper includes implications for the testing of growth models, suggesting there may be an association between movement into service sectors and higher growth, as modern service sectors have important spillovers on and from the manufacturing. Moreover, the way countries engage in global value changes may affect growth.

Originality/value

Using a unique data set, this paper adds to the empirical literature on economic growth that looks closer at the distinction between the role of structural change and changes in composition ode demand.

Details

Journal of Economic Studies, vol. 41 no. 4
Type: Research Article
ISSN: 0144-3585

Keywords

Open Access
Article
Publication date: 30 June 2008

Young Yoon Choi, Hun-Koo Ha and Minions Park

The maritime freight transportation industry has played an important role in the Korean economy. The Korean maritime freight transportation industry is faced with a period of…

Abstract

The maritime freight transportation industry has played an important role in the Korean economy. The Korean maritime freight transportation industry is faced with a period of transforming it competitively and efficiently in this global age. This paper, therefore, aims to identify the impact of the maritime freight transportation industry in the Korean national economy. Hence, this paper provides policy-makers with accessible and reliable information regarding the role of the Korean maritime freight transportation industry. This study employs input-output (I-O) analysis to examine the role of the maritime freight transportation industry in the national economy for the period 1995-2003, with specific application to Korea. This study pays particular attention to the maritime freight transportation industry by taking the industry as exogenous variable and then investigates its economic impacts. We identify inter-industry linkage effects in 20 sectors, production-inducing effects, added value-inducing effects, and supply-shortage effects of the maritime freight transportation industry.

Details

Journal of International Logistics and Trade, vol. 6 no. 1
Type: Research Article
ISSN: 1738-2122

Keywords

Article
Publication date: 19 April 2013

Štefan Bojnec

The purpose of this paper is to introduce cybernetic systems in defence management applications, to meet new challenges of the information society and use of system modelling for…

704

Abstract

Purpose

The purpose of this paper is to introduce cybernetic systems in defence management applications, to meet new challenges of the information society and use of system modelling for decision making.

Design/methodology/approach

The paper defines basic terms for understanding the complexity of the defence management applications, which is simplified using inputoutput modelling.

Findings

The paper illustrates the interdisciplinary nature of cybernetics, systems and management sciences. The defence system is analysed and a general inputoutput model for defence system development recommended.

Research limitations/implications

New data technology and data availability provide perspective for applied research using scientific approach.

Practical implications

Cybernetic systems for defence provide analytical modelling for management applications.

Originality/value

The paper presents a concept and empirical evidence for defence system analysis and a new way of thinking that affects defence planning and defence management. A cybernetic, systemic and inputoutput methodology provides solutions for defence management applications.

Details

Kybernetes, vol. 42 no. 4
Type: Research Article
ISSN: 0368-492X

Keywords

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