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您的检索式：作者名="Azmat Ullah"
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| 1 | Meteorological impacts on evapotranspiration in different climatic zones of Pakistan显示文摘Arid regions are highly vulnerable and sensitive to drought. The crops cultivated in arid zones are at high risk due to the high evapotranspiration and water demands. This study analyzed the changes in seasonal and annual evapotranspiration(ET) during 1951–2016 at 50 meteorological stations located in the extremely arid, arid, and semi-arid zones of Pakistan using the Penman Monteith(PM) method. The results show that ET is highly sensitive and positively correlated to temperature, solar radiation, and wind speed whereas vapor pressure is negatively correlated to ET. The study also identifies the relationship of ET with the meteorological parameters in different climatic zones of Pakistan. The significant trend analysis of precipitation and temperature(maximum and minimum) are conducted at 95% confidence level to determine the behaviors of these parameters in the extremely arid, arid, and semi-arid zones. The mean annual precipitation and annual mean maximum temperature significantly increased by 0.828 mm/a and 0.014℃/a in the arid and extremely arid zones, respectively. The annual mean minimum temperature increased by 0.017℃/a in the extremely arid zone and 0.019℃/a in the arid zone, whereas a significant decrease of 0.007℃/a was observed in the semi-arid zone. This study provides probabilistic future scenarios that would be helpful for policy-makers, agriculturists to plan effective irrigation measures towards the sustainable development in Pakistan. | Shahzada ADNAN Kalim ULLAH Azmat H KHAN GAO Shouting | 2017 | Journal of Arid Land2017，9，6： | 2 |
| 2 | Optimal periodic replacement policy for a warranted product subject to multi modes failure process显示文摘A complex product subjects to multiple failure modes such as minor and catastrophic failure with some probability.This paper investigates the effects of minor failure and catastrophic failure on the periodic replacement policy for a complex product supported by a warranty period.Cost models are developed and the expected optimal replacement policies are developed analytically such that long run expected life-cycle cost rate is minimized.Structural properties of the optimal replacement policies are derived for a product which fails with multiple failure modes and the failure rate is an increasing function of time.Finally,a numerical experiment is performed to show the important features of our study. | Azmat Ullah Wei Jiang | 2019 | Journal of Management Analytics2019，6，2： | 1 |
| 3 | Benchmarking Performance of Document Level Classification and Topic Modeling显示文摘Text classification of low resource language is always a trivial and challenging problem.This paper discusses the process of Urdu news classification and Urdu documents similarity.Urdu is one of the most famous spoken languages in Asia.The implementation of computational methodologies for text classification has increased over time.However,Urdu language has not much experimented with research,it does not have readily available datasets,which turn out to be the primary reason behind limited research and applying the latest methodologies to the Urdu.To overcome these obstacles,a mediumsized dataset having six categories is collected from authentic Pakistani news sources.Urdu is a rich but complex language.Text processing can be challenging for Urdu due to its complex features as compared to other languages.Term frequency-inverse document frequency(TFIDF)based term weighting scheme for extracting features,chi-2 for selecting essential features,and Linear discriminant analysis(LDA)for dimensionality reduction have been used.TFIDF matrix and cosine similarity measure have been used to identify similar documents in a collection and find the semantic meaning of words in a document FastText model has been applied.The training-test split evaluation methodology is used for this experimentation,which includes 70%for training data and 30%for testing data.State-of-the-art machine learning and deep dense neural network approaches for Urdu news classification have been used.Finally,we trained Multinomial Naïve Bayes,XGBoost,Bagging,and Deep dense neural network.Bagging and deep dense neural network outperformed the other algorithms.The experimental results show that deep dense achieves 92.0%mean f1 score,and Bagging 95.0%f1 score. | Muhammad Shahid Bhatti Azmat Ullah Rohaya Latip Abid Sohail Anum Riaz Rohail Hassan | 2022 | Computers, Materials & Continua2022，，4： | 1 |
| 4 | Individual and combination approaches to forecasting hierarchical time series with correlated data:an empirical study显示文摘Hierarchical time series arise in manufacturing and service industries when the products or services have the hierarchical structure,and top-down and bottomup methods are commonly used to forecast the hierarchical time series.One of the critical factors that affect the performance of the two methods is the correlation between the data series.This study attempts to resolve the problem and shows that the top-down method performs better when data have high positive correlation compared to high negative correlation and combination of forecasting methods may be the best solution when there is no evidence of the correlationship.We conduct the computational experiments using 240 monthly data series from the‘Industrial’category of the M3-Competition and test twelve combination methods for the hierarchical data series.The results show that the regression-based,VAR-COV and the Rank-based methods perform better compared to the other methods. | Hakeem-Ur Rehman Guohua Wan Azmat Ullah Badiea Shaukat Antai | 2019 | Journal of Management Analytics2019，6，3： | 0 |
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