Search results

Contact problems are among the most difficult ones in mechanics. Due to its practical importance, the problem has been receiving extensive research work over the years. The finite element method has been widely used to solve contact problems with various grades of complexity. Great progress has been made on both theoretical studies and engineering applications. This paper reviews some of the main developments in contact theories and finite element solution techniques for static contact problems. Classical and variational formulations of the problem are first given and then finite element solution techniques are reviewed. Available constraint methods, friction laws and contact searching algorithms are also briefly described. At the end of the paper, a bibliography is included, listing about seven hundred papers which are related to static contact problems and have been published in various journals and conference proceedings from 1976.

Contract incompleteness with deficiency, inconsistency, defectiveness, and ambiguity in contract clauses, which can cause misunderstandings and misinterpretations, may result with disputes in projects. This study aims to investigate contract incompleteness factors with a hybrid fuzzy multi-criteria decision approach.

Contract incompleteness factors were ranked by fuzzy VIKOR (Visekriterijumska Optimizacija I Kompromisno Resenje) method, and the most significant factors were subjected to fuzzy decision-making trial and evaluation laboratory (DEMATEL) to examine their causal relationships. The study is not limited to ranking the identified factors solely, since their cause-effect interactions are also essential for proper risk management in construction projects.

Hybrid use of multi-criteria analysis reveals that ambiguity in enforceability including excessive demands and significant amendments in the scope of works are the top two causal contract incompleteness factors, while lack of implementation details and focus of focal point, and insufficient supporting and technical documents are the most affected ones.

Contractual causes of disputes due to contract incompleteness factors other than requirements of the contracts have been rarely investigated in the literature. The research is one of the first studies in the literature investigating the causal relationship among factors in construction contracts, which might lead to project disputes. Findings are expected to improve contract drafting, eventually contributing to effective risk management in construction projects.

The utilisation of market-based approaches (MBAs) than command-control approaches (CCAs) is still at the embryonic stage to stimulate the green behaviour of small and medium-sized enterprises (SMEs) in developing economies. The study aims to elucidate the association between environmental incentives (EIs), green responsiveness (GR) and environmental performance (EP).

A quantitative dominant research design is adopted with qualitative support. The study model is developed by integrating legitimacy theory (LT) and the natural resource-based view (NRBV). The cross-sectional data were gathered from the upper echelon of 395 SMEs in Sri Lanka, and 10 subsequent interviews were conducted. The partial least squares approach of structural equation modelling (PLS-SEM) was used to evaluate the hypothesised relationships.

The results found evidence to demonstrate that EIs positively link with GR and EP and GR mediates this association. Further, the study revealed that although MBAs are established, the SME sector is less aware of EIs such as tax concessions, tax reliefs, low interest, soft loans and discounts on eco-materials.

The results provide valuable insights to enhance environmental sustainability. The owners of SMEs should strategically use environmental inducements to overcome resource poverty to engage in green practices. The regulators and policymakers should develop the incentive policies and provide the mechanisms to disseminate the required skills and technologies to SMEs.

According to the authors' best knowledge, this is one of the pioneering empirical studies on EIs, GR and EP with mediating effects in Sri Lanka.

The purpose of this paper is to explore the challenges and influential factors experienced in the development of public sector accounting reforms in the emerging economy of Sri Lanka. The reforms aim to improve public governance and transparency while reducing corruption and dishonesty.

Qualitative (thematic) analysis has been employed by using both primary and secondary data. Primary data was obtained by interviewing selected respondents from public sector organisations in Sri Lanka. The respondents were selected by using an expert purposive sampling technique. Apart from the primary data, secondary data such as government reports, relevant literature and paper articles was also analysed in order to produce more robust findings.

The findings indicate that technological and cultural factors have influenced accounting reforms in the public sector in Sri Lanka. In addition, the politicisation and bureaucracy of the public sector as well as sluggish attitudes towards costs have served as prominent barriers to efficient implementation of the reforms.

This study was limited in terms of generalisation because of relatively small sample sizes. A larger sample with more diversity could have enhanced the generalisation of the results which could serve as direction for further research.

This paper is intended to fill a gap in the existing literature on public sector accounting reforms in the context of less developed or emerging countries. It is hopefully valuable for both policy makers and practitioners by allowing them to view the development, challenges and influential aspects of the implementation of New Public Management (NPM) in Sri Lanka in order that they will be able to make informed decisions about adopting more efficient NPM practices to enhance the country’s competitive advantages.

The purpose of this study is to find the optimum design of Reinforced Concrete (RC) pile foundation to enable efficient use of structural concrete with greater consequences for global environment and economy.

A non-linear optimisation technique based on the Generalised Reduced Gradient (GRG) algorithm was implemented to find the minimum cost of RC pile foundation in frictional soil. This was achieved by obtaining the optimum pile satisfying the serviceability and ultimate limit state requirements of BS 8004 and EC 7. The formulated structural optimisation procedure was applied to a case study project to assess the efficiency of the proposed design formulation.

The results prove that the GRG method in Excel solver is an active, fast, accurate and efficient computer programme to obtain optimum pile design. The application of the optimisation for the case study project shows up to 26% cost reduction compared to the conventional design.

The design and formulation of design constraints will be limited to provisions of BS 8004 and EC 7.

Since the minimum quantity of concrete was attained through optimisation, then minimum cement will be used and thus result in minimum CO₂ emission. Therefore, the optimum design of concrete structures is a vital solution to limit the damage to the Earth's climate and the physical environment resulting from high carbon emissions.

The current study considers the incorporation of different soil ground parameters in the optimisation process rather than assuming any pile capacity value for the optimisation process.

A newly developed frequency-independent lumped parameter model (LPM) is the purpose of the present paper. This new model’s direct outcome ensures high efficiency and a straightforward calculation of foundations’ vertical vibrations. A rigid circular foundation shape resting on a nonhomogeneous half-space subjected to a vertical time-harmonic excitation is considered.

A simple model representing the soil–foundation system consists of a single degree of freedom (SDOF) system incorporating a lumped mass linked to a frequency-independent spring and dashpot. Besides that, an additional fictitious mass is incorporated into the SDOF system. Several numerical methods and mathematical techniques are used to identify each SDOF’s parameter: (1) the vertical component of the static and dynamic foundation impedance function is calculated. This dynamic interaction problem is solved by using a formulation combining the boundary element method and the thin layer method, which allows the simulation of any complex nonhomogeneous half-space configuration. After, one determines the static stiffness’s expression of the circular foundation resting on a nonhomogeneous half-space. (2) The system’s parameters (dashpot coefficient and fictitious mass) are calculated at the resonance frequency; and (3) using a curve fitting technique, the general formulas of the frequency-independent dashpot coefficients and additional fictitious mass are established.

Comparisons with other results from a rigorous formulation were made to verify the developed model’s accuracy; these are exceptional cases of the more general problems that can be addressed (problems like shallow or embedded foundations of arbitrary shape, other vibration modes, etc.).

In this new LPM, the impedance functions will no longer be needed. The engineer only needs a limited number of input parameters (geometrical and mechanical characteristics of the foundation and the soil). Moreover, a simple calculator is required (i.e. we do not need any sophisticated software).

The economic literature on labor migration has incorporated insights from various disciplines with regard to content and method, although the representation of migrants has not fully moved away from the neoliberal, market-dominated framework. This paper addresses the issue of women migrant workers using the particular example of Sri Lankan migrant women workers to the Middle East. It aims to highlight the need for more diversity in economic research without which conceptual representation, as well as empirical reach, is limited.

After a brief overview of the representation of migrants in economic literature, I develop the concept of vulnerability. I refer to qualitative and quantitative analyses on Sri Lankan migrant women workers to the Middle East from a variety of disciplines in order to differentiate the “vulnerable,” that is, the workers in need of protection, from the “vulnerabilities.” The latter concept refers to the debilitating effects on workers, produced by market forces, which are often perpetuated by underlying assumptions, as well as policies. A broader, inter-disciplinary perspective, which considers the agency of women, can go a long way toward removing some of the limitations and preconceptions ingrained in most economic representation. This in turn could help to improve the protection of the vulnerable and empower them to better face market forces.

This paper aims to report how one can assess the transient stability of a power system by using stacked auto-encoders.

The proposed algorithm works in a power system equipped with the wide area measurement system. To be more exact, it needs pre- and post-disturbance values of frequency sent from phasor measurement units.

The authors have investigated the performance of the proposed method. Going through details, the authors have simulated many contingencies, and then have predicted the transient stability in each of which by using the proposed algorithm.

The results demonstrate that the algorithm is fast, and it has acceptable performance under different circumstances including the change of system topology and failures of telecommunication channels.

This paper aims to examine the association between green innovation and the cost of equity in China. This study relies on the investors’ base perspective and shareholders’ perceived risk perspective to investigate the relation between green innovation and the cost of equity in China.

The paper uses firm-fixed effect regression for a sample of Chinese public companies for the period 2008–2018.

The authors find a negative relationship between green innovation and the cost of equity capital. This negative association is found to be more pronounced for less financially constrained firms, during periods of high economic policy uncertainty, and for firms with a strong internal control environment. Finally, the paper shows that the negative association became more pronounced after the passage of the Environmental Protection Law of China in 2012. The results remain robust to possible endogeneity concerns.

This study contributes to the green innovation literature by documenting that shareholders favorably view firms implementing green innovation policies. The study also has policy implications for Chinese regulators in improving the green credit policy.

Conflicts, claims and disputes are inherent in most construction projects. Acceptable degree of commonality in the interpretation of contract provisions is critical in effective contract administration. This study aims to assess the effects of contract ambiguity factors on construction conflicts, highlighting the causes of divergent interpretations using fuzzy technique for order of preference by the similarity-to-ideal-solution (TOPSIS) method.

Fuzzy TOPSIS framework with 27 ambiguity factors is constructed by conducting a comprehensive literature review, accompanied by a pilot study. Questionnaire survey is formed, and one-to-one interviews are arranged with 35 contract administration experts.

The findings indicate that (1) ambiguity due to excessive changes in the bill of quantity (BOQ) (including ambiguous provisions related to BOQ changes), (2) incomplete clauses that do not describe the scope of the intended work purely, (3) ambiguity due to excessive amendments in the scope of works (including ambiguous provisions related to scope changes), (4) ambiguous enforceability including excessive demands and (5) ambiguous goal and performance requirements are the top five ambiguity factors affecting construction conflicts.

Presented framework is performed referring to ambiguity factors in all type of construction contracts in the general sense. However, the identified factors may vary depending on the project type, contract type, procurement method or use of standard contract forms (such as NEC, FIDIC).

The literature lacks the investigation of ambiguity factors in construction contracts, yet the assessment of the effects of contract ambiguity is essential to minimize conflicts.