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Article
Publication date: 1 March 2013

Shahadat Khan

This paper presents the outcome of research related to application of formal rules and standard procedures in EAsʼ procurement of goods and services for foreign aid-funded…

186

Abstract

This paper presents the outcome of research related to application of formal rules and standard procedures in EAsʼ procurement of goods and services for foreign aid-funded projects. Executing agencies are entrusted to implement foreign aid-funded projects on behalf of respective governments and they are required to satisfy a combination of rules of their multiple principals, mainly donor organizations and respective government ministries. The theoretical framework of this study is guided by agency theory. The findings indicate that the processing of procurement related information and awarding contracts by the executing agencies in the context of Bangladesh is heavily dependent on the informal working systems or “unwritten ground rules”. These are driven by downward hierarchical verbal and non-verbal instructions. The study has adopted a qualitative method following a grounded theory approach.

Details

Journal of Public Procurement, vol. 13 no. 2
Type: Research Article
ISSN: 1535-0118

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Article
Publication date: 7 September 2015

Qing Wang, Yadong Dou, Jiangxiong Li and Yinglin Ke

The purpose of this paper is to design a reasonable joining path and achieve assembly automation for multiple arc-shaped panels. A fuselage panel is primarily composed of skins…

352

Abstract

Purpose

The purpose of this paper is to design a reasonable joining path and achieve assembly automation for multiple arc-shaped panels. A fuselage panel is primarily composed of skins, stringers, frames and clips. Both inserted and nested structures are adopted in the panels to improve the strength and hermeticity of the fuselage. Due to the complex structures and relationships, it is a challenge to coordinate the arc-shaped panels in the assembly process.

Design/methodology/approach

A motion sequence model which achieves arc approximation based on the relative motion of multiple panels is established. The initial position of the panels is obtained by decomposing the computer-aided design model of the panels. Two translation rules, i.e. progressively decreasing translation and limited deformation translation, are applied to determine the moving path of the panels. If a panel is not at its path node, a search algorithm is used to find the nearest path node. Finally, the key algorithms are implemented in an integration system to promote joining automation of multiple panels.

Findings

The zigzag path is effective for the joining of multiple panels with complex mating relationships. The automation of the join–separate–rejoin operations is time-saving and safety-assuring. The proposed method is demonstrated in practical engineering and a good efficiency is obtained.

Practical implications

This method has been used in a middle fuselage assembly project. The practical results show that the zigzag path is convenient to be stored and reused, and the synchronous movements of multiple curved panels are precisely realized. Additionally, the posture accuracy of panels is significantly improved, and the operating time is reduced considerably.

Originality/value

This paper gives a solution including path planning and process integration to solve the joining problem of multiple panels. The research will promote the automation of fuselage assembly.

Details

Assembly Automation, vol. 35 no. 4
Type: Research Article
ISSN: 0144-5154

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Article
Publication date: 28 January 2014

Hong Xiao, Yuan Li, Jian-Feng Yu and Hui Cheng

Virtual assembly process plays an important role in assembly design of complex product and is typically time- and resource-intensive. This paper aims to investigate a dynamic…

582

Abstract

Purpose

Virtual assembly process plays an important role in assembly design of complex product and is typically time- and resource-intensive. This paper aims to investigate a dynamic assembly simplification approach in order to demonstrate and interact with virtual assembly process of complex product in real time.

Design/methodology/approach

The proposed approach regards the virtual assembly process of complex product as an incremental growth process of dynamic assembly. During the growth process, the current-assembled-state assembly model is simplified with appearance preserved by detecting and removing its invisible features, and the to-be-assembled components are simplified with assembly features preserved using conjugated subgraphs matching method based on an improved subgraph isomorphism algorithm.

Findings

The dynamic assembly simplification approach is applied successfully to reduce the complexity of computer aided design models during the virtual assembly process and it is proved by several cases.

Originality/value

A new assembly features definition is proposed based on the notion of “conjugation” to assist the assembly features recognition, which is a main step of the dynamic assembly simplification and has been translated into conjugated subgraphs matching problem. And an improved subgraph isomorphism algorithm is presented to address this problem.

Details

Assembly Automation, vol. 34 no. 1
Type: Research Article
ISSN: 0144-5154

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Article
Publication date: 2 November 2020

Vishal R. Mehta and Mayur P. Sutaria

The purpose of this paper is to evaluate the influence of temperature, load and sliding speed on wear and friction behavior of LM25/SiC composites in as-cast and heat-treated…

69

Abstract

Purpose

The purpose of this paper is to evaluate the influence of temperature, load and sliding speed on wear and friction behavior of LM25/SiC composites in as-cast and heat-treated conditions.

Design/methodology/approach

The LM25/SiC aluminum matrix composites (AMCs) were prepared using the stir casting process. The wear tests were carried out using a pin-on-disc setup in dry condition. The three levels of each parameter, i.e. 100, 150 and 200°C operating temperature; 15, 25 and 35 N load; 0.8, 1.6 and 2.4 m/sec sliding speed, were considered for the investigation. ANOVA has been carried out to evaluate the percentage contribution of parameters. Scanning electron microscope analysis of worn surfaces has been carried out to understand the wear mechanism.

Findings

The wear and coefficient of friction (COF) increase with the increase in the temperature, load and sliding speed within a selected range for as-cast as well as heat-treated LM25/SiC AMCs. The mean values of wear and COF in heat-treated samples were found to be lower than as-cast samples for all cases. It was observed that the percentage wear increases significantly as temperature increases in as-cast AMCS. Mild to severe wear transition was observed at 150°C. In heat-treated AMCs, mild wear was observed irrespective of temperature. It was also observed that as the temperature increases, transition of wear mechanism from abrasive to adhesive (including delamination) occurs earlier in as-cast samples as compared to heat-treated samples.

Originality/value

There is a lack of data on combined effect of temperature, load and sliding speed on tribological aspects of as-cast and heat-treated LM25/SiC AMCs, limiting its applications. The present research work has addressed this gap.

Details

World Journal of Engineering, vol. 18 no. 2
Type: Research Article
ISSN: 1708-5284

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Article
Publication date: 25 July 2019

Zhoupeng Han, Rong Mo, Haicheng Yang and Li Hao

Three-dimensional computer-aided design (CAD) assembly model has become important resource for design reuse in enterprises, which implicates plenty of design intent, assembly…

254

Abstract

Purpose

Three-dimensional computer-aided design (CAD) assembly model has become important resource for design reuse in enterprises, which implicates plenty of design intent, assembly intent, design experience knowledge and functional structures. To acquire quickly CAD assembly models associated with specific functions by using product function requirement information in the product conceptual design phase for model reuse, this paper aims to find an approach for structure-function correlations analysis and functional semantic annotation of mechanical CAD assembly model before functional semantic-based assembly retrieval.

Design/methodology/approach

An approach for structure-function correlations analysis and functional semantic annotation of CAD assembly model is proposed. First, the product knowledge model is constructed based on ontology including design knowledge and function knowledge. Then, CAD assembly model is represented by part attributed adjacency graph and partitioned into multiple functional regions. Assembly region and flow-activity region are defined for structure-function correlations analysis of CAD assembly model. Meanwhile, the extraction process of assembly region and flow-activity region is given in detail. Furthermore, structure-function correlations analysis and functional semantic annotation are achieved by considering comprehensively assembly structure and assembled part shape structure in CAD assembly model. After that, a structure-function relation model is established based on polychromatic sets for expressing explicitly and formally relationships between functional structures, assembled parts and functional semantics.

Findings

The correlation between structure and function is analyzed effectively, and functional semantics corresponding to structures in CAD assembly model are labeled. Additionally, the relationships between functional structures, assembled parts and functional semantics can be described explicitly and formally.

Practical implications

The approach can be used to help designers accomplish functional semantic annotation of CAD assembly models in model repository, which provides support for functional semantic-based CAD assembly retrieval in the product conceptual design phase. These assembly models can be reused for product structure design and assembly process design.

Originality/value

The paper proposes a novel approach for structure-function correlations analysis and functional semantic annotation of mechanical CAD assembly model. Functional structures in assembly model are extracted and analyzed from the point of view of assembly structure and function part structure. Furthermore, the correlation relation between structures, assembled parts and functional semantics is expressed explicitly and formally based on polychromatic sets.

Details

Assembly Automation, vol. 39 no. 4
Type: Research Article
ISSN: 0144-5154

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Book part
Publication date: 29 September 2023

Torben Juul Andersen

The global environments that surround contemporary business activities are uncertain, fast-changing, and frequently exposed to abrupt unexpected events with the potential to…

Abstract

The global environments that surround contemporary business activities are uncertain, fast-changing, and frequently exposed to abrupt unexpected events with the potential to inflict extreme impacts where the ability to respond and adapt the organization effectively becomes a primary strategic concern. However, various firms that operate across diverse industry contexts approach this adaptive challenge in distinct ways that lead to quite diverse outcomes with many negative performers and some high performers with positive risk features. The heterogeneous approaches appear to consistently form extreme left-tailed performance distributions with inverse risk-return features but we are not really able to explain why and how these regularly observed phenomena come about. Hence, we want to study these organizational artifacts by collecting an extensive updated dataset to test the proposed relationships, explore alternative explanations, and learn from the extreme exemplars often referred to as outliers. There are extensive literatures in (strategic) management and finance that have dealt with the distribution of firm returns from slightly different angles but with some emerging commonalities that can inspire further analyses of the performance data. As a precursor for this, we discuss the odds of effective strategic adaptation in complex dynamic environments and introduce resilience as a proper outcome when simple solutions are scarce, and consider conditions that may facilitate these aims. The premises for the ensuing analyses are laid out and the main contents of the following chapters are presented.

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A Study of Risky Business Outcomes: Adapting to Strategic Disruption
Type: Book
ISBN: 978-1-83797-074-2

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Book part
Publication date: 23 August 2011

Sascha Raithel, Sebastian Scharf, Charles R. Taylor, Manfred Schwaiger and Lorenz Zimmermann

Purpose – Marketers are under increasing pressure to demonstrate the financial return associated with marketing expenditures. Concurrently, more attempts at measuring return on…

Abstract

Purpose – Marketers are under increasing pressure to demonstrate the financial return associated with marketing expenditures. Concurrently, more attempts at measuring return on investment from marketing as well as achieving other long-term goals such as building brand equity and increasing shareholder value have been made. As a result of this emphasis, the degree to which advertising budgets are spent efficiently and the impact of these expenditures on the bottom line are an important topic to study.

Methodology/approach – This study applies data envelopment analysis (DEA) to a group of large firms to assess the degree to which companies spend advertising dollars efficiently and to examine the impact of advertising efficiency on investor behavior and, ultimately, stock prices.

Findings – The analysis reveals that firms that advertise more efficiently are rewarded by investors by positive stock returns.

Research limitations/implications (if applicable) – The study is limited to large enterprises with strong brands within a time frame of only four years.

Practical implications (if applicable) – The results imply that it is advisable for marketing managers not to limit their focus to increasing market-based assets at any cost. The efficiency of their efforts can send a positive signal to investors and contribute to shareholder value enhancement.

Originality/value of the chapter – The chapter finds investors to pay attention not only to the effectiveness of advertising activities but also to their efficiency. The study also demonstrates how DEA and stock return response modeling can be combined to investigate the link between advertising efficiency and investor behavior.

Details

Measurement and Research Methods in International Marketing
Type: Book
ISBN: 978-1-78052-095-7

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Article
Publication date: 6 August 2018

Remigiusz Romuald Iwańkowicz and Michał Taraska

The purpose of the paper is to develop a method of automatic classification of the components of the assembly units. The method is crucial for developing an automatic ship…

325

Abstract

Purpose

The purpose of the paper is to develop a method of automatic classification of the components of the assembly units. The method is crucial for developing an automatic ship assembly planning tools. The proposed method takes into account the assumptions specific for shipbuilding technology processes: high complexity of structures, difficult expert-based classification of components, fixed priority relations between connections resulting from geometrical constraints and demands of welding processes.

Design/methodology/approach

The set of ex post determined liaisons and assembly sequences constitutes the database of structures which have been made-up earlier. The components classification problem is solved using matrix coding of graphs. Information in such form is stored in the database. The minimization of number of cycles in the graph of classes sequence and minimization of diversity of classes within all constructions has been proposed as criteria of optimization. The genetic algorithm has been proposed as a solution method.

Findings

The proposed method solves the problem of components’ classifications. It allows setting the pattern of priorities between classes of various connections. This gives a chance to determine the relationship constraints between the connections of new structures for which assembly sequences are not established.

Research limitations/implications

Mathematical formulation of the database is quite laborious. The possibility of partial automation of this process should be considered. Owing to the complexity of the problem, a relatively simple objective function has been proposed. During a ship hull assembly, additional criteria should be taken into account, what will be the direction of further research.

Practical implications

Automatic classification of components is dedicated for implementation in shipyards and similar assembly systems. Tests performed by the authors confirm efficiency of presented method in supporting management of the database and assembly of new structures planning. Suggested activity-oriented approach allows for easy conversion of any assembly unit structure to the form of a matrix.

Originality/value

The new approach for components classification according to its assembly features distinguishes the proposed method from others. The use of nilpotent matrix theory in an acyclicity of graphs analysis is also a unique achievement. Original crossover and mutation operators for assembly sequence were proposed in the article.

Details

Assembly Automation, vol. 38 no. 3
Type: Research Article
ISSN: 0144-5154

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Book part
Publication date: 21 July 2020

Torben Juul Andersen

The environmental exposures to humankind have increased in number and intensity over past decades introducing the possibility of extreme incidents with irreversible impacts on…

Abstract

The environmental exposures to humankind have increased in number and intensity over past decades introducing the possibility of extreme incidents with irreversible impacts on business and society. The global integration of business and cross-border financial flows supported by digital technology increase the complexity and uncertainty of the business environment. In this context, the behaviors of individual players are interdependent with potentially nonlinear and unpredictable outcomes ascribed to complex wicked problems. As a consequence, organizational decision-makers may pursue false objectives from misinformed causation where stringent score-card controls will exacerbate the problems. The resolution to wicked problems requires cross-functional and collective interactions supported by a collaborative corporate mindset. The conventional control-based management practices fall short in dealing with disruptive developments where value-based stakeholder collaboration can provide resilient responses to unexpected abrupt events.

Details

Adapting to Environmental Challenges: New Research in Strategy and International Business
Type: Book
ISBN: 978-1-83982-477-7

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Article
Publication date: 27 December 2022

Eswara Krishna Mussada

The purpose of the study is to establish a predictive model for sustainable wire electrical discharge machining (WEDM) by using adaptive neuro fuzzy interface system (ANFIS)…

41

Abstract

Purpose

The purpose of the study is to establish a predictive model for sustainable wire electrical discharge machining (WEDM) by using adaptive neuro fuzzy interface system (ANFIS). Machining was done on Titanium grade 2 alloy, which is also nicknamed as workhorse of commercially pure titanium industry. ANFIS, being a state-of-the-art technology, is a highly sophisticated and reliable technique used for the prediction and decision-making.

Design/methodology/approach

Keeping in the mind the complex nature of WEDM along with the goal of sustainable manufacturing process, ANFIS was chosen to construct predictive models for the material removal rate (MRR) and power consumption (Pc), which reflect environmental and economic aspects. The machining parameters chosen for the machining process are pulse on-time, wire feed, wire tension, servo voltage, servo feed and peak current.

Findings

The ANFIS predicted values were verified experimentally, which gave a root mean squared error (RMSE) of 0.329 for MRR and 0.805 for Pc. The significantly low RMSE verifies the accuracy of the process.

Originality/value

ANFIS has been there for quite a time, but it has not been used yet for its possible application in the field of sustainable WEDM of titanium grade-2 alloy with emphasis on MRR and Pc. The novelty of the work is that a predictive model for sustainable machining of titanium grade-2 alloy has been successfully developed using ANFIS, thereby showing the reliability of this technique for the development of predictive models and decision-making for sustainable manufacturing.

Details

World Journal of Engineering, vol. 21 no. 2
Type: Research Article
ISSN: 1708-5284

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