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Development of stability-preserving time-limited model reduction framework for 2-D and 1-D models with error bound

Control Theory and Technology 2022年第3期20卷 371-381页

作者： muhammad Imran Syeda Hira Ambreen Syed Nooh Hamdani muhammad Imran muhammad ejaz naveed Maria Siddiqui Department of Electrical Engineering Military College of Signals(MCS)National University of Sciences and Technology(NUST)Islamabad43000Pakistan Department of Electrical Engineering Sir Syed(Center For Advanced Studies)Institute of Technology(SSCASE)Islamabad43000Pakistan College of Science and Humanities Rumah Majmaah UniversityRumahKingdom of Saudi Arabia

Due to their complex structure,2-D models are challenging to work with;additionally,simulation,analysis,design,and control get increasingly difficult as the order of the model grows.Moreover,in particular time intervals,Gawronski and Juang’s time-limited model reduction schemes produce an unstable reduced-order model for the 2-D and 1-D models.Researchers revealed some stability preservation solutions to address this key flaw which ensure the stability of 1-D reduced-order systems;nevertheless,these strategies result in large approximation errors.However,to the best of the authors’knowledge,there is no literature available for the stability preserving time-limited-interval Gramian-based model reduction framework for the 2-D discrete-time systems.In this article,2-D models are decomposed into two separate sub-models(i.e.,two cascaded 1-D models)using the condition of minimal rank-decomposition.Model reduction procedures are conducted on these obtained two 1-D sub-models using limited-time Gramian.The suggested methodology works for both 2-D and 1-D models.Moreover,the suggested methodology gives the stability of the reduced model as well as a priori error-bound expressions for the 2-D and 1-D models.Numerical results and comparisons between existing and suggested methodologies are provided to demonstrate the effectiveness of the suggested methodology.

关键词： Model reduction Weighted Gramian Limited interval Gramian Minimal realization Approximation error Error bound

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In Vitro Study of Callogenesis and Regeneration Potential of Elite Wheat (Triticum aestivum L.) Cultivars

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American Journal of Plant Sciences 2016年第17期7卷 2515-2526页

作者： muhammad Iqbal naveed Iqbal Raja Saira Asif Noshin Ilyas Mubashir Hussain Farhat Yasmeen muhammad ejaz muhammad Asim Sultan Sumaira Aslam Hina Javed Department of Botany PMAS-Arid Agriculture University Rawalpindi Pakistan Department of Botany University of Sargodha Sargodha Pakistan

The potential for biotechnological applications in crop improvement programs requires identifying genotypes that allow cell/tissue culture with predictable plant regeneration. In the past, many genotypes of wheat (Triticum aestivum L.) have been examined for potential use in tissue culture studies. The present research work has also been designed to study in vitro callogenesis expression and regeneration potential of wheat cultivars under controlled laboratory conditions. Seeds of four elite commercial high yielding cultivars of wheat namely: NARC-2011, AAS-2011, PAK-2013 and GAL-2013, were collected from the Crop Science Institute National Agricultural Research Center (CSI-NARC) Islamabad, as the source of plant material for in vitro studies. The seeds were surface sterilized in 10% sodium hypochlorite solutions for 10 minutes with continuous shaking under laminar air flow hood. After that seeds were placed on MS (Murashige & Skoog, 1962) based callus induction and regeneration medium with various concentrations of 2, 4-D and BAP in separate test tubes. Maximum callus induction frequency of 90% for Pak-13 and AAS-11, followed by 87% and 83% for Gla-13 and NARC-11, respectively, was recorded at 4 mg/l and 6 mg/l of 2, 4-D. Similarly, maximum regeneration of 90% for AAS-11 and Pak-13, followed by 80% and 87% for NARC-11 and Gla-13 respectively, was recorded on MS basal medium containing 1.5 mg/l of BAP. An increasing trend in regeneration from 0.5 to 1.5 mg/l of BAP was observed but it gradually decreased with increasing concentration of BAP from 1.5 mg/l for all wheat cultivars. The callus formed under light was golden brown, dry nodule and smooth compact and less embryogenic while under dark conditions, it was white to yellowish white, dry nodule and compact and more embryogenic. Best results for callus induction and regeneration were obtained at temperature (24°C ± 1°C) for all wheat cultivars.

关键词： Tissue Culture MS Medium 2 4-D and BAP Callus Induction Regeneration Wheat

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Current Status of <i>Withania somnifera</i>(L.) Dunal: An Endangered Medicinal Plant from Himalaya

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American Journal of Plant Sciences 2017年第5期8卷 1159-1169页

作者： Sumaira Aslam naveed Iqbal Raja Mubashir Hussain muhammad Iqbal muhammad ejaz Danish Ashfaq Hira Fatima muhammad Ali Shah Abd-Ur-Rehman Maria Ehsan Department of Botany PMAS Arid Agriculture University Rawalpindi Pakistan Department of Botany University of Sargodha Sargodha Pakistan Department of Biological Sciences University of Lahore Sargodha Pakistan Department of Biotechnology University of Azad Jammu & Kashmir Muzaffarabad Pakistan

Withania somnifera is highly medicinal plant species of Pakistan floristically placed in the Western Himalayan Province, Himalaya Range of Azad Jammu and Kashmir and in the Soon valley (Salt Range) of Punjab Pakistan. It grows in high altitude of 5500 feet in the Himalayas. Its English name is Winter Cherry and its Urdu name is Asghand/Kutilal. It is the low lying shrub of about 1.50 m in height with erect branching. It grows in dry arid regions of Pakistan, India, China and Bangladesh. Its flowers are bisexual, small, axillary, greenish, solitary and few-flowered cymes. Chemical analysis of Ashwagandha showed that it has alkaloids and steroidal lactones (withanolides) as the main chemical constituent. W. somnifera has not yet been assessed for the IUCN Red List. However, in Pakistan, W. somnifera is falling under criteria A of endangered category. Asghand (W. somnifera) acquires much therapeutic potential which include sedative, narcotic, thyroid stimulation, anti-inflammatory, hypnotic, anti-stress, general tonic, diuretic, antimicrobial, and antitumor activities. There are number of threats responsible for the decrease of W. somnifera number in western Himalayan range and salt range of Punjab Pakistan which may include deforestation over exploitation and climatic changes. Conservation strategies need to be adopted for improving the population pool of W. somnifera. There is also the dire need to conserve this important medicinal plant species with some standard biotechnological approaches and conservation strategies in future.

关键词： Withania somnifera Endangered Antimicrobial Antitumor Conservation

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A probe into the medicinal potential of Viola canescens-A threatened medicinal plant from Himalaya

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Journal of Coastal Life Medicine 2016年第7期4卷 575-579页

作者： Sidra Sabir Abida Akram naveed Iqbal Raja Zia-ur-Rehman Mashwani Sohail Huma Mehreen Sadaf Mubashir Hussain Iqra Riaz Nabeela Ahmad ejaz Ahmed Department of Botany PMAS-Arid Agriculture UniversityRawalpindiPakistan

Viola canescens Wall.ex Roxb.is a perennial herb belonging to family Violaceae,and it is almost cosmopolitan in distribution.This plant is widely used in Ayurveda and Unani medicinal systems for curing various ailments,most commonly for cough and cold.Phytochemical studies releaved that this plant is rich in secondary metabolites.This plant revealed significant antimicrobial,anti-inflamatory,antioxidant,hepatoprotective,laxative,analgesic as well as antitumor activities.Due to all these important pharmacological activities,market demand of Viola canescens is increasing day by day and this plant is facing tremendous over exploitation and becomes a threatened plant according to International Union for Conservation of Nature and Natural Resources.The present review compiles that the ethnobotanical,phytochemical and pharmacological aspects of the plant need to be conserved.

关键词： Viola canescens Medicinal systems Secondary metabolites Pharmacological activities

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