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1.
Mohamed-Chahir Fitouhi Mustapha Nourelfath 《International Journal of Production Economics》2012,136(2):344-351
This paper deals with the problem of integrating noncyclical preventive maintenance and tactical production planning for a single machine. We are given a set of products that must be produced in lots during a specified finite planning horizon. The maintenance policy suggests possible preventive replacements at the beginning of each production planning period, and minimal repair at machine failure. The proposed model determines simultaneously the optimal production plan and the instants of preventive maintenance actions. The objective is to minimize the sum of preventive and corrective maintenance costs, setup costs, holding costs, backorder costs and production costs, while satisfying the demand for all products over the entire horizon. The problem is solved by comparing the results of several multi-product capacitated lot-sizing problems. The value of the integration and that of using noncyclical preventive maintenance when the demand varies from one period to another are illustrated through a numerical example and validated by a design of experiment. The later has shown that the integration of maintenance and production planning can reduce the total maintenance and production cost and the removal of periodicity constraint is directly affected by the demand fluctuation and can also reduce the total maintenance and production cost. 相似文献
2.
Hakim Ben Hammouda Stephen N. Karingi Nassim Oulmane Mustapha Sadni Jallab 《Oxford Development Studies》2013,41(2):187-208
This paper proposes an extensive data simulation exercise on the likely impact of non-agricultural market access liberalization. The paper analyses real options for tariff cut reduction, special and differential treatment and the treatment of unbound tariffs. This paper also gives indications concerning the likely economic impact of this trade round of industrial market access negotiations on African economies. It shows that an ambitious tariff cut reduction formula would provide greater access to developed country markets for African producers. However, this kind of formula has a major drawback for African countries in the sense that it could accelerate the de-industrialization of African countries and limit incentives to diversify their economies. 相似文献
3.
Ahmet Faruk AYSAN Mustapha Kamel NABLI Marie‐Ange VGANZONS‐VAROUDAKIS 《The Developing economies》2007,45(3):339-377
This paper addresses the issue of the low level of private investment in the Middle East and North Africa (MENA) region, with special emphasis on the role of governance. Based on the existing published reports, we categorize what types of governance institutions are more detrimental to entrepreneurial investments. We then estimate a simultaneous model of private investment and governance quality where economic policies concurrently explain both variables. Our empirical results show that governance plays a significant role in private investment decisions. This result is particularly true in the case of “administrative quality” in the form of control of corruption, bureaucratic quality, investment‐friendly profile of administration, law and order, as well as for “political stability.” Evidence in favor of “public accountability” is also found. Our estimations also stress that structural reforms like financial development, trade openness, and human development affect private‐investment decisions directly, and/or through their positive effect on governance. 相似文献
4.
The effect of the regularity of the error process on the performance of kernel regression estimators
This article considers estimation of regression function $f$ in the fixed design model $Y(x_i)=f(x_i)+ \epsilon (x_i), i=1,\ldots ,n$ , by use of the Gasser and Müller kernel estimator. The point set $\{ x_i\}_{i=1}^{n}\subset [0,1]$ constitutes the sampling design points, and $\epsilon (x_i)$ are correlated errors. The error process $\epsilon $ is assumed to satisfy certain regularity conditions, namely, it has exactly $k$ ( $=\!0, 1, 2, \ldots $ ) quadratic mean derivatives (q.m.d.). The quality of the estimation is measured by the mean squared error (MSE). Here the asymptotic results of the mean squared error are established. We found that the optimal bandwidth depends on the $(2k+1)$ th mixed partial derivatives of the autocovariance function along the diagonal of the unit square. Simulation results for the model of $k$ th order integrated Brownian motion error are given in order to assess the effect of the regularity of this error process on the performance of the kernel estimator. 相似文献
5.
This article argues that the traditional belief that “consumer ethnocentrism is a phenomenon of the developed countries only” is no longer true. To establish this argument, this study assesses the applicability of the Consumer Ethnocentric Tendencies Scale (CETSCALE) to a developing country Bangladesh. The methodology is based on 788 samples collected from 27 districts of Bangladesh. Results show that for three chosen sociodemographic groups namely, students, job holders, and businessmen, the CETSCALE is to a much extent applicable as the groups have shown positive attitudes in retaining 12 to 14 items out of the 17 items of the original scale. 相似文献
6.
Abdul Raufu Mustapha 《Oxford Development Studies》2013,41(4):405-425
Concern about the environment in colonial northern Nigeria developed out of a series of controversies and practices, particularly those relating to agriculture. Increasingly, local practices that have sustained the population and the environment for centuries are subjected to “scientific” scrutiny. Though many of these practices were either misunderstood or not understood at all, this did not stop the subjugation of local practices to “science”. However, this “scientific” enterprise was often conflict-ridden, with important questions being resolved only after the intervention of political authorities. The resulting colonial practices in the fields of irrigation, forest management and the application of chemical fertilizer continue to dominate the thinking of state officials in post-colonial Nigeria, leading to unsustainable policies. An earlier colonial tradition of investigating the practices of local farmers and the constraints therein would have been a more appropriate basis for post-colonial policy. 相似文献
7.
This paper, using multi‐level modelling, sought to highlight student‐level and school‐level characteristics that differentiate the academic performance in mathematics from a sample of 6080 Moroccan secondary students who participated in the 2011 Trends in International Mathematics and Science Study (TIMSS) test. The results indicated little evidence to support the Heyneman–Loxley effect, as they showed that individual and family characteristics were the strongest determinants of achievement compared to the schools’ factors. Students scored higher when they were boys, were younger, were more self‐confident, were more ambitious, and felt secure in school. They also scored higher when they came from families with a higher socioeconomic status, particularly when their parents were able to ensure the availability of learning resources, and were of a higher level of education. Finally, schools were matter for their pupil achievement mainly through the location channel, as urban pupils outperformed rural ones. However, the other school characteristics, including those related to teachers, played a negative, or at best neutral, role in pupil outcomes. These findings have important public policy implications. Redesigning education policy towards improving the school's environment and fostering inclusivity would be needed to enhance learning performance of Moroccan students. 相似文献
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9.
Mustapha K. Nabli 《Open Economies Review》1990,1(2):111-145
The paper addresses the issue of trade liberalization in developing countries from a political economy perspective using the theory of collective action. The role of collective action and interest group behavior is analysed critically both with respect to the initiation of attemps at liberalization and its outcome in terms of success or failure. A probit model is then used to test empirically the various hypotheses as to the determinants of likelihood of success of liberalization attempts. A sample of 51 liberalization episodes relating to 24 countries and spanning the period 1950–80 is used. Five factors are found to be critical in the process of liberalization: the strength of exporters groups as represented by the diversification and importance of manufactures and traditional exports, the strength of import-competing sector's opposition as measured by the share of manufacturing in GDP, the time elapsed since the beginning of import substitution, the size of country and the leadership committment and role. 相似文献
10.
Nicholas Addai Boamah 《Journal Of African Business》2017,18(2):238-256
The Capital Asset Pricing Model (CAPM), and the Fama-French and Carhart models have been widely applied in the developed and most emerging markets; however, there is scant evidence of the viability of the models on the African Frontier Stock Markets (AFSMs). This study examines the viability of the models for a sample that pools securities across nine AFSMs, and whether or not the risk factors of these models command risk premium on the AFSMs. The paper provides evidence of the existence of the size, value and momentum effects on the AFSMs. In addition, the models only partly capture the returns to size and book-to-market sorted portfolios on the AFSMs. Also, the risk factors of these models generally, command marginally significant premium on the AFSMs. Caution should in general be exercised when applying these models on the AFSMs. 相似文献