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1 – 10 of over 3000Satish Kumar, Tushar Kolekar, Ketan Kotecha, Shruti Patil and Arunkumar Bongale
Excessive tool wear is responsible for damage or breakage of the tool, workpiece, or machining center. Thus, it is crucial to examine tool conditions during the machining process…
Abstract
Purpose
Excessive tool wear is responsible for damage or breakage of the tool, workpiece, or machining center. Thus, it is crucial to examine tool conditions during the machining process to improve its useful functional life and the surface quality of the final product. AI-based tool wear prediction techniques have proven to be effective in estimating the Remaining Useful Life (RUL) of the cutting tool. However, the model prediction needs improvement in terms of accuracy.
Design/methodology/approach
This paper represents a methodology of fusing a feature selection technique along with state-of-the-art deep learning models. The authors have used NASA milling data sets along with vibration signals for tool wear prediction and performance analysis in 15 different fault scenarios. Multiple steps are used for the feature selection and ranking. Different Long Short-Term Memory (LSTM) approaches are used to improve the overall prediction accuracy of the model for tool wear prediction. LSTM models' performance is evaluated using R-square, Mean Absolute Error (MAE), Root Mean Square Error (RMSE) and Mean Absolute Percentage Error (MAPE) parameters.
Findings
The R-square accuracy of the hybrid model is consistently high and has low MAE, MAPE and RMSE values. The average R-square score values for LSTM, Bidirection, Encoder–Decoder and Hybrid LSTM are 80.43, 84.74, 94.20 and 97.85%, respectively, and corresponding average MAPE values are 23.46, 22.200, 9.5739 and 6.2124%. The hybrid model shows high accuracy as compared to the remaining LSTM models.
Originality/value
The low variance, Spearman Correlation Coefficient and Random Forest Regression methods are used to select the most significant feature vectors for training the miscellaneous LSTM model versions and highlight the best approach. The selected features pass to different LSTM models like Bidirectional, Encoder–Decoder and Hybrid LSTM for tool wear prediction. The Hybrid LSTM approach shows a significant improvement in tool wear prediction.
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Dehui Li, Libo Fan and Zhenning Yang
Although the importance of network embeddedness attracted much attention in recent years, the interpretations of the underlying mechanism almost focus on the positive effects and…
Abstract
Purpose
Although the importance of network embeddedness attracted much attention in recent years, the interpretations of the underlying mechanism almost focus on the positive effects and neglect the potential negative aspects. This paper aims to use Chinese listed manufacturing enterprises, in the perspective of network embeddedness, to analyze whether resource curse effects exist in strategic networks of enterprises.
Design/methodology/approach
This paper examines the resource curse effect that exists in enterprise networks through analysis of enterprise’s total factors productivity compared with those of its industry peers with different degrees of embeddedness. This paper then uses several different methods, such as clustered fixed and random effect model, core and peripheral model, and generalized method of moments estimation in endogenous checks, to detect network curse effects and reveal three potential mechanisms, including overinvestment, extra maintaining cost and innovation extrusion.
Findings
This paper finds that excessive network embeddedness hinders continuous improvement of productivity, which is derived from three mechanisms: excessive network embeddedness makes information redundancy among enterprises, and the imitate-follow effect makes excessive investment seriously; enterprises have to encounter more problems and difficulties, such as information coordination and benefit negotiation, to maintain network relationship, which leads to extra cost; enterprises with abundant network resources may tend to more emphasis on marketable operational abilities, resulting in resource decentralization and less investment on innovation, which is finally not beneficial to productivity improvement in the long run.
Originality/value
Compared with previous literatures, this paper not only enriches the understanding of negative mechanisms in enterprise`s network embeddedness, but also unfolds the inconsistency of network embeddedness effects in practice and finds new evidence that the two types of network embeddedness are consistent in certain circumstances.
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The purpose of this paper is to investigate the resource rents–quality-adjusted human capital nexus and the impact of quality of institutions.
Abstract
Purpose
The purpose of this paper is to investigate the resource rents–quality-adjusted human capital nexus and the impact of quality of institutions.
Design/methodology/approach
For a large data set of 161 countries for the period 1996–2018 (yearly and 4-year periods), fixed effect estimation method is applied to investigate the impact of resource rents on quality-adjusted human capital and the role of quality of institutions on this relationship.
Findings
The paper found little evidence on the negative, significant and direct impact of total resource rents on quality-adjusted human capital. However, the results show that the negative effect of resource rents can be mediated by the quality of institutions. This result is robust to a long list of controls, different specifications and estimation techniques, as well as several robustness checks. Therefore, institutional quality seems to play a critical role in determining the indirect impact of natural resources on human capital. Moreover, the obtained results demonstrate that this resource adverse effect depends on the type of resource rents; in particular, high dependency on oil rents in developing countries appears to harm human capital.
Research limitations/implications
The paper shows that it is not obvious that total resource rents decrease human capital and found that the coefficient is no longer significant in the two-way fixed effects model. However, the analysis has emphasized the crucial role of political institutions in this relationship and has shown that countries with higher quality of institutions make the most of their resource rents transiting to a better human capital environment. This result is found to be robust to a list of controls, different specifications and estimation techniques, as well as several robustness checks. In addition, we demonstrate that not all resources affect human capital in the same way and found that oil rents have a significant negative effect on human capital. This is an important distinction since several countries are blessing from oil rents. From this we conclude that the effect of natural resources on human capital varies across different types of commodities. On the other hand, the interaction between institutions and the sub-categories of resource rents shows that oil rents can increase human capital only in developing countries with higher quality of institutions (above the threshold). This result is also still hold while using alternative measures of political institutions.
Practical implications
The results in this paper have important policy implications. In particular, results highlight important heterogeneities in the role resource rents to the economy. As international commodity prices have shown high volatility in recent years, it is important for policy makers to understand the rents. Rents which are the difference between the price of a commodity and the average cost of producing it can have different effects in the economy, including the human capital. It is shown that in countries with low-quality institutions, natural resource rents negatively affect institutional quality, leading to conflicts, corruption and fostering rent-seeking activities. Overall, this reinforces the elite at the power that, obviously, is interested in preserving the status quo. In other words, there is a vicious circle between resource rents and low-quality institutions that impedes institutional change. How to regulate this in the best possible way requires a good understanding of how resource rents are generated and appropriated for different sectors, their different effects and how people react to these rents. The evidence suggests the policy toward better political institutions may help countries to improve social outcomes such as health and education which offer high social returns.
Originality/value
The paper is part of the author's PhD research and is an original contribution.
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Tania El Kallab and Cristina Terra
This paper explores the role of colonial heritage on long-term economic development from a resource-curse perspective. The authors investigate the impact of colonial exports on…
Abstract
Purpose
This paper explores the role of colonial heritage on long-term economic development from a resource-curse perspective. The authors investigate the impact of colonial exports on long-term economic development through two channels: (1) a direct impact of the economic dependency on natural resources and (2) an indirect impact via its effect on colonial institutions, which persisted over time and influenced current economic development.
Design/methodology/approach
To address this issue, the authors use an original data set on French bilateral trade from 1880 to 1912. The authors use partial least square structural equation modeling (PLS-SEM) in the empirical analysis, so that the authors are able to construct latent variables (LVs) for variables that are not directly observable, such as the quality of institutions.
Findings
The authors find that exports of primary goods to France had a negative impact on colonial institutions and that for French colonies, this impact was driven by minerals exports. Despite its impact on colonial institutions, exports of French colonies had no significant indirect impact on their current institutions. The authors find no significant direct impact of colonial trade on current development for French colonies. Finally, colonial exports of manufactured products had no significant impact on colonial institutions among French colonies and a positive impact among non-French ones.
Research limitations/implications
Research implications regarding the findings of this paper are, namely, that the relative poor performance within French colonies today cannot be attributed to the extraction of raw materials a century ago. However, human capital and institutional development, instead of exports, are more relatively important for long-term growth. Some limitations in trying to determine the simultaneous relationship among colonial trade, institutions and economic performance are the relation between colonial trade and the extent of extraction from the colonizer, which is hard to quantify, as well as its precise mechanism.
Practical implications
Since the initial institutions set in those former colonies presented a strong persistence in the long run, their governments should focus now on building sound and inclusive political and economic institutions, as well as on investing in human capital in order to foster long-term growth. Once a comprehensive set of institutional and human resources are put in place, the quality and quantity of exports might create a positive spillover on the short-run growth.
Social implications
One social implication that can be retrieved from this study is the ever-lasting effect of both human capital investment and introduction of inclusive political and economic institutions on the long-run impact of growth.
Originality/value
The paper uses an original primary data set from archival sources to explore the role of colonial heritage on long-term economic development from a resource-curse perspective. It applies a relatively new model partial least squares path modeling (PLS-PM) that allows the construction of LVs for variables that are not directly observable, as well as channeling the impact on growth through both direct and indirect channels. Finally, it allows for the simultaneous multigroup analysis across different colonial groups.
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This chapter analyzes the aggregate performance of Home Run Derby competitors’ performance both before and after the Home Run Derby for the time period 1999–2013. Regression to…
Abstract
This chapter analyzes the aggregate performance of Home Run Derby competitors’ performance both before and after the Home Run Derby for the time period 1999–2013. Regression to the mean suggests that in general, those players with outstanding performances in the first half of the season will regress to the mean. The findings here are consistent with regression to the mean, and the mean performance along four key analytics is statistically significantly worse for the competitors. However, the winners’ mean performance both before and after the Home Run Derby are not statistically significantly different. Thus, the results are consistent with previous research, but the results also find so-called “winner and loser” effects in Major League Baseball.
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David Pick, Kandy Dayaram and Bella Butler
This paper aims to present the case of the Pilbara as an illustration of how neo‐liberalism and globalisation affect a natural resource region.
Abstract
Purpose
This paper aims to present the case of the Pilbara as an illustration of how neo‐liberalism and globalisation affect a natural resource region.
Design/methodology/approach
A primary data set was collected by interviewing 21 people who had an interest in the development of the Pilbara. Secondary data was collected from relevant government policy documents and media reports relating to the region. Qualitative analysis techniques were used to analyse the data.
Findings
It is found that neo‐liberal policy has had a profound and largely negative effect on Pilbara communities. Rather than reaping the benefits of the wealth being generated in the region, participants in this research experience social breakdown and unmet social needs, and the local democratic institutions are weak and ineffective. Research limitations/implications – This paper reports on a single case and is limited in terms of its generalisability. However, it does illustrate the value of the “Resource Curse Thesis” and the concept of “risk” in illuminating the issues associated with neo‐liberalism.
Practical implications
This research has practical implications in that it provides an example of the problems associated with neo‐liberal perspectives when they are used as a framework for developing and implementing regional policy.
Originality/value
The resource curse thesis tends to be used in analysing developing nations and risk has so far been applied in limited areas of researching the effects of neo‐liberal policy trajectories. This paper employs these concepts to provide a critical examination of regional development policy in a way that can be used in other national contexts.
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This paper aims to explore the impact of domestic market fragmentation on the innovation performance of enterprises and its mechanism from the perspective of market segmentation…
Abstract
Purpose
This paper aims to explore the impact of domestic market fragmentation on the innovation performance of enterprises and its mechanism from the perspective of market segmentation, a government behavior with Chinese characteristics.
Design/methodology/approach
In order to verify the theoretical hypothesis proposed in the previous article, that is, whether domestic market fragmentation can effectively improve the innovation performance of enterprises, this paper bases on the data of listed companies from 2010 to 2016, empirically testing the theoretical hypothesis by constructing a measurement model.
Findings
Domestic market fragmentation has a significant inhibitory effect on enterprise innovation performance. Domestic market fragmentation has heterogeneous effects on innovation performance of enterprises and regions. It is undeniable that domestic market fragmentation does have a certain support effect on state-owned enterprises but the support effect is achieved by distorting regional resource allocation and creating an unfair market environment.
Originality/value
Firstly, this paper explores the impact mechanism of domestic market fragmentation on corporate innovation performance from the perspective of market segmentation, a government behavior with Chinese characteristics, so as to expand and enrich the relevant research on enterprise innovation. Secondly, from the perspective of corporate innovation performance, this paper provides new evidence for the “curse effect” of domestic market fragmentation. Thirdly, this paper tries to shake the domestic market fragmentation support theory from the perspective of distortion effect brought by the “hand of support” of domestic market fragmentation.
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The purpose of this paper is to examine the underpricing effect in Treasury auctions.
Abstract
Purpose
The purpose of this paper is to examine the underpricing effect in Treasury auctions.
Design/methodology/approach
The paper compares two winner's curse models using a dataset on multi‐unit auctions. The dataset is from Swedish Treasury auctions, which is under a discriminatory auction mechanism. One model is a single‐unit equilibrium model assuming that each bidder bids for 100 percent of the auctioned securities, which is described by Wilson and solved by Levin and Smith. The other model is a multi‐unit model calibrated by Goldreich using the US Treasury auctions data and assumes that each bidder bids for one unit of the auctioned securities.
Findings
The empirical results show that, although both models work well in predicting the bid‐shading, the multi‐unit model fits the Swedish Treasury auctions data better than the single‐unit model.
Research limitations/implications
The evidence implies that bidders rationally adjust their bids due to the winner's curse/champion's plague.
Originality/value
This study provides close quantitative predictions of the amount of bid‐shading using both single‐unit model of Wilson and multi‐unit model of Goldreich, and indicates that winner's curse or champion's plague worries bidders in countries other than the USA.
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Opoku Adabor, Emmanuel Buabeng and Juliet Fosua Dunyo
While the relationship between natural resource rent and economic growth is well documented in the literature, not much robust analysis has been done to estimate the causative…
Abstract
Purpose
While the relationship between natural resource rent and economic growth is well documented in the literature, not much robust analysis has been done to estimate the causative relationship between oil resource rent and economic growth in Ghana. This might be due to the fact that commercial production of crude oil started not long ago in Ghana. This paper aims to examine the causal relationship between oil resource rent and economic growth for the period of 2011 to 2020 in Ghana.
Design/methodology/approach
The study incorporates economic growth as a function of oil resource rent, non-oil revenue, foreign direct investment, capital and interest rate in a Cobb–Douglass production function/model. The study used four different estimation strategies including the autoregressive distributed lags model, Toda–Yamamoto test approach, nonlinear autoregressive distributed lags model and nonlinear Granger causality.
Findings
The main finding revealed that 1% increase in oil resource rent generates 0.84% increase in economic growth of Ghana in the long run. Contrary, the authors find an insignificant positive effect of oil resource rent on economic growth of Ghana in the short run for the period under study. The result from the Toda–Yamamoto test approach also showed a unidirectional causality running from oil resource rent to economic growth of Ghana, providing evidence in support of the resource blessing hypothesis in Ghana. The results are robust to two different alternative estimation strategies.
Originality/value
The causal relationship between crude oil resource rent and economic growth is examined.
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Shinaj Valangattil Shamsudheen, Mudeer Ahmed Khattak, Aishath Muneeza and Makeen Huda
This study aims to investigate the reaction (in terms of returns and volatility) of Gulf Cooperation Council (GCC) country-wise stock markets (both conventional and Islamic) in…
Abstract
Purpose
This study aims to investigate the reaction (in terms of returns and volatility) of Gulf Cooperation Council (GCC) country-wise stock markets (both conventional and Islamic) in response to the surge of COVID-19 cases, with special reference to the announcement of financial stimulus packages in each country and the recent global oil price plunge. Further, the study also examines the impact of COVID-19 cases on the stock market returns of each GCC country and the continuous dynamics of correlation between COVID-19 cases and GCC stock markets.
Design/methodology/approach
This study uses an exponential generalized auto regressive conditional heteroskedasticity model and continuous wavelet coherence to estimate the stock market volatility and co-movement between COVID-19 cases and stock returns.
Findings
Empirical findings indicate an adverse reaction (negative returns and high volatility) during the period examined, with the stimulus package resulting in a positive transformation of returns in each country-level stock market as well as the regional stock index. Further, no evidence of an adverse effect of the oil price plunge is identified. All findings are identical between both conventional and Islamic stock indices.
Originality/value
While ample research has been conducted on the impact and dynamics of the pandemic on stock markets, little has addressed the areas of financial stimulus packages and the oil price plunge. The findings of this study show that further research needs to be conducted to elucidate the ways in which effective financial stimulus packages can be formulated in the GCC region to mitigate the adverse effects of COVID-19 for economies without causing major financial deficits, as well as to find strategies to diversify economies away from the oil curse.
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