Search results

1 – 10 of 72
Per page
102050
Citations:
Loading...
Access Restricted. View access options
Book part
Publication date: 4 November 2021

Vasileios Vlachos and Aristidis Bitzenis

Greece's slow recovery from the severe economic depression caused by the great global financial and economic crisis that erupted in late 2000s was interrupted by the effects of…

Abstract

Greece's slow recovery from the severe economic depression caused by the great global financial and economic crisis that erupted in late 2000s was interrupted by the effects of COVID-19 pandemic on economic activity. This chapter looks into the factors shaping Greece's competitive position and discusses the potential to achieve a V-shaped recovery at the end of the pandemic.

Details

Modeling Economic Growth in Contemporary Greece
Type: Book
ISBN: 978-1-80071-123-5

Keywords

Access Restricted. View access options
Article
Publication date: 1 April 2008

M. Grujicic, G. Arakere, P. Pisu, B. Ayalew, Norbert Seyr, Marc Erdmann and Jochen Holzleitner

Application of the engineering design optimization methods and tools to the design of automotive body‐in‐white (BIW) structural components made of polymer metal hybrid (PMH…

577

Abstract

Application of the engineering design optimization methods and tools to the design of automotive body‐in‐white (BIW) structural components made of polymer metal hybrid (PMH) materials is considered. Specifically, the use of topology optimization in identifying the optimal initial designs and the use of size and shape optimization techniques in defining the final designs is discussed. The optimization analyses employed were required to account for the fact that the BIW structural PMH component in question may be subjected to different in‐service loads be designed for stiffness, strength or buckling resistance and that it must be manufacturable using conventional injection over‐molding. The paper demonstrates the use of various engineering tools, i.e. a CAD program to create the solid model of the PMH component, a meshing program to ensure mesh matching across the polymer/metal interfaces, a linear‐static analysis based topology optimization tool to generate an initial design, a nonlinear statics‐based size and shape optimization program to obtained the final design and a mold‐filling simulation tool to validate manufacturability of the PMH component.

Details

Multidiscipline Modeling in Materials and Structures, vol. 4 no. 4
Type: Research Article
ISSN: 1573-6105

Keywords

Access Restricted. View access options
Book part
Publication date: 11 August 2017

Maria Adelaide Pedrosa da Silva Duarte and Marta Cristina Nunes Simões

European Union (EU) central and eastern economies have gone through a process of structural change since 1989, when the post-communist transition started. This process was…

Abstract

European Union (EU) central and eastern economies have gone through a process of structural change since 1989, when the post-communist transition started. This process was afterwards reinforced by the three EU enlargement waves that took place in 2004, 2007 and 2013. Though exhibiting low levels of aggregate productivity, this group of countries joined the EU with higher levels of human capital than the southern member states, an advantage that should have accelerated real convergence towards the EU15. However, evidence to date suggests that the convergence process came to a halt in 2007–2008 when massive capital inflows stopped, highlighting the fragilities of the growth strategies implemented so far. In these peripheral countries, structural change has been characterised by an expanding services sector alongside growing income inequality. The two strands of literature on these issues highlight that: (a) an expanding services sector may not be detrimental for growth, quite the opposite, depending on services composition and on the capacity of services sub-sectors to incorporate information and communication technologies (ICTs); and (b) inequality is negatively related to growth through the fiscal policy, socio-political instability, borrowing constraints to investment in education and endogenous fertility channels and positively through the savings channel and incentives. We analyse the nexus between structural change, inequality and growth in this group of countries highlighting income inequality as a potential mechanism that connects the other two variables. We provide a descriptive quantitative analysis of the profiles of structural change and income inequality in our sample and apply dynamic panel methods to investigate the existence of causality among services sector expansion, inequality and aggregate productivity considering a maximum period between 1980 and 2010.

Details

Core-Periphery Patterns Across the European Union
Type: Book
ISBN: 978-1-78714-495-8

Keywords

Access Restricted. View access options
Article
Publication date: 1 January 2009

M. Grujicic, G. Arakere, V. Sellappan, J.C. Ziegert and D. Schmueser

Among various efforts pursued to produce fuel efficient vehicles, light weight engineering (i.e. the use of low‐density structurally‐efficient materials, the application of…

729

Abstract

Among various efforts pursued to produce fuel efficient vehicles, light weight engineering (i.e. the use of low‐density structurally‐efficient materials, the application of advanced manufacturing and joining technologies and the design of highly‐integrated, multi‐functional components/sub‐assemblies) plays a prominent role. In the present work, a multi‐disciplinary design optimization methodology has been presented and subsequently applied to the development of a light composite vehicle door (more specifically, to an inner door panel). The door design has been optimized with respect to its weight while meeting the requirements /constraints pertaining to the structural and NVH performances, crashworthiness, durability and manufacturability. In the optimization procedure, the number and orientation of the composite plies, the local laminate thickness and the shape of different door panel segments (each characterized by a given composite‐lay‐up architecture and uniform ply thicknesses) are used as design variables. The methodology developed in the present work is subsequently used to carry out weight optimization of the front door on Ford Taurus, model year 2001. The emphasis in the present work is placed on highlighting the scientific and engineering issues accompanying multidisciplinary design optimization and less on the outcome of the optimization analysis and the computational resources/architecture needed to support such activity.

Details

Multidiscipline Modeling in Materials and Structures, vol. 5 no. 1
Type: Research Article
ISSN: 1573-6105

Keywords

Access Restricted. View access options
Article
Publication date: 29 January 2018

John David McEwen Arnold and Don Lafreniere

The purpose of this paper is to create a longitudinal data-driven model of change over time in a postindustrial landscape, using the “Copper Country” of Michigan’s Upper Peninsula…

450

Abstract

Purpose

The purpose of this paper is to create a longitudinal data-driven model of change over time in a postindustrial landscape, using the “Copper Country” of Michigan’s Upper Peninsula as a case study. The models resulting from this project will support the heritage management and public education goals of the contemporary communities and Keweenaw National Historical Park that administer this nationally significant mining region through accessible, engaging, and interpretable digital heritage.

Design/methodology/approach

The paper applies Esri’s CityEngine procedural modeling software to an existing historical big data set. The Copper Country Historical Spatial Data Infrastructure, previously created by the HESA lab, contains over 120,000 spatiotemporally specific building footprints and other built environment variables. This project constructed a pair of 3D digital landscapes comparing the built environments of 1917 and 1949, reflecting the formal and functional evolution of several of the most important copper mining, milling, and smelting districts of Michigan’s Keweenaw Peninsula.

Findings

This research discovered that CityEngine, while intended for rapid 3D modeling of the contemporary urban landscape, was sufficiently robust and flexible to be applied to modeling serial historic industrial landscapes. While this novel application required some additional coding and finish work, by harnessing this software to existing big data sets, 48,000 individual buildings were rapidly visualized using several key variables.

Originality/value

This paper presents a new and useful application of an existing 3D modeling software, helping to further illuminate and inform the management and conservation of the rich heritage of this still-evolving postindustrial landscape.

Details

Journal of Cultural Heritage Management and Sustainable Development, vol. 8 no. 4
Type: Research Article
ISSN: 2044-1266

Keywords

Access Restricted. View access options
Article
Publication date: 14 October 2020

Xianliang Zhang, Weibing Zhu, Xiande Wu, Ting Song, Yaen Xie and Han Zhao

The purpose of this paper is to propose a pre-defined performance robust control method for pre-assembly configuration establishment of in-space assembly missions, and collision…

170

Abstract

Purpose

The purpose of this paper is to propose a pre-defined performance robust control method for pre-assembly configuration establishment of in-space assembly missions, and collision avoidance is considered during the configuration establishment process.

Design/methodology/approach

First, six-degrees-of-freedom error kinematic and dynamic models of relative translational and rotational motion between transportation systems are developed. Second, the prescribed transient-state performance bounds of tracking errors are designed. In addition, based on the backstepping, combining the pre-defined performance control method with a robust control method, a pre-defined performance robust controller is designed.

Findings

By designing prescribed transient-state performance bounds of tracking errors to guarantee that there is no overshoot, collision-avoidance can be achieved. Combining the pre-defined performance control method with a robust control method, robustness to disturbance is guaranteed.

Originality/value

This paper proposed a pre-defined performance robust control method. Simulation results demonstrate that the proposed controller can achieve a pre-assembly configuration establishment with collision avoidance in the existence of external disturbances.

Details

Aircraft Engineering and Aerospace Technology, vol. 93 no. 1
Type: Research Article
ISSN: 1748-8842

Keywords

Access Restricted. View access options
Article
Publication date: 19 April 2022

Fatemeh Aamazadeh, Mohammad Alizadeh, Alireza Farsad-Naeimi and Zahra Tofighi

Food insecurity exists when access to nutritionally sufficient and secure foods or the ability to obtain admissible foods in socially acceptable ways is limited or uncertain. Food…

143

Abstract

Purpose

Food insecurity exists when access to nutritionally sufficient and secure foods or the ability to obtain admissible foods in socially acceptable ways is limited or uncertain. Food insecurity is most likely associated with chronic disease. However, research into the possible relationship between food insecurity and cancer, the world’s second leading cause of death, is limited. The purpose of this study was to determine the level of food insecurity as well as the associated socioeconomic characteristics among cancer patients.

Design/methodology/approach

A cross-sectional study was conducted on 240 cancer patients in Iran. The socioeconomic and 18-item U.S. Department of Agriculture (USDA) Food Security Questionnaires were used to measure general and socioeconomic characteristics, as well as food security status.

Findings

The prevalence of food insecurity was 25.4% in the form of hunger and 52.5% in the form of hidden hunger. Only 22.1% of the patients were food secure. The results of the logistic regression analysis revealed that having children under 18 years old (P = 0.035), economic status (P < 0.001), age of the patient (P = 0.001), educational level of household’s head and his spouse (P = 0.044 and P = 0.045, respectively, had statistically significant relationships with food insecurity.

Originality/value

Cancer patients have a high rate of food insecurity. Considering the importance of food security for effective cancer treatment, the health system’s attention to this issue, particularly by policymakers, appears to be required.

Details

Nutrition & Food Science , vol. 53 no. 1
Type: Research Article
ISSN: 0034-6659

Keywords

Access Restricted. View access options
Article
Publication date: 8 May 2023

Lucas Willian Aguiar Mattias and Leilson Joaquim Araujo

This study aims to optimize the structural design of reinforced concrete columns with variable hollow circular sections.

49

Abstract

Purpose

This study aims to optimize the structural design of reinforced concrete columns with variable hollow circular sections.

Design/methodology/approach

The columns were optimized according to the criteria of instability (buckling) and mechanical strength (compression and/or tensile strength). To perform the optimizations, routines are developed in Python using the penalty and sequential linearization programming (SLP) function methods to optimize the elements satisfying the buckling and stress criteria.

Findings

At the end of the optimization process, the optimal section is obtained for the example of a circular column with a variable section, this section has an average radius of 5% smaller than that initially defined.

Originality/value

The theoretical basis for column optimization and the structuring of an algorithm in Python language for the computational resolution of these problems are presented in a didactic way, as well as the comparative efficiency of the methods.

Details

Multidiscipline Modeling in Materials and Structures, vol. 19 no. 4
Type: Research Article
ISSN: 1573-6105

Keywords

Available. Open Access. Open Access
Article
Publication date: 2 June 2022

Hanyu Yang, Jing Zhao and Meng Wang

This study aims to propose a centralized optimal control model for automated left-turn platoon at contraflow left-turn lane (CLL) intersections.

605

Abstract

Purpose

This study aims to propose a centralized optimal control model for automated left-turn platoon at contraflow left-turn lane (CLL) intersections.

Design/methodology/approach

The lateral lane change control and the longitudinal acceleration in the control horizon are optimized simultaneously with the objective of maximizing traffic efficiency and smoothness. The proposed model is cast into a mixed-integer linear programming problem and then solved by the branch-and-bound technique.

Findings

The proposed model has a promising control effect under different geometric controlled conditions. Moreover, the proposed model performs robustly under various safety time headways, lengths of the CLL and green times of the main signal.

Originality/value

This study proposed a centralized optimal control model for automated left-turn platoon at CLL intersections. The lateral lane change control and the longitudinal acceleration in the control horizon are optimized simultaneously with the objective of maximizing traffic efficiency and smoothness

Access Restricted. View access options
Article
Publication date: 5 August 2021

Farzad Kiani, Amir Seyyedabbasi and Sajjad Nematzadeh

Efficient resource utilization in wireless sensor networks is an important issue. Clustering structure has an important effect on the efficient use of energy, which is one of the…

186

Abstract

Purpose

Efficient resource utilization in wireless sensor networks is an important issue. Clustering structure has an important effect on the efficient use of energy, which is one of the most critical resources. However, it is extremely vital to choose efficient and suitable cluster head (CH) elements in these structures to harness their benefits. Selecting appropriate CHs and finding optimal coefficients for each parameter of a relevant fitness function in CHs election is a non-deterministic polynomial-time (NP-hard) problem that requires additional processing. Therefore, the purpose of this paper is to propose efficient solutions to achieve the main goal by addressing the related issues.

Design/methodology/approach

This paper draws inspiration from three metaheuristic-based algorithms; gray wolf optimizer (GWO), incremental GWO and expanded GWO. These methods perform various complex processes very efficiently and much faster. They consist of cluster setup and data transmission phases. The first phase focuses on clusters formation and CHs election, and the second phase tries to find routes for data transmission. The CH selection is obtained using a new fitness function. This function focuses on four parameters, i.e. energy of each node, energy of its neighbors, number of neighbors and its distance from the base station.

Findings

The results obtained from the proposed methods have been compared with HEEL, EESTDC, iABC and NR-LEACH algorithms and are found to be successful using various analysis parameters. Particularly, I-HEELEx-GWO method has provided the best results.

Originality/value

This paper proposes three new methods to elect optimal CH that prolong the networks lifetime, save energy, improve overhead along with packet delivery ratio.

Details

Sensor Review, vol. 41 no. 4
Type: Research Article
ISSN: 0260-2288

Keywords

1 – 10 of 72
Per page
102050