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      • KCI등재

        Board Governance and Bank’s Performance: Does Size Matter?

        Atia ALAM,Syeda Fizza ABBAS,Ameena HAFEEZ 한국유통과학회 2020 The Journal of Asian Finance, Economics and Busine Vol.7 No.11

        Over the last few decades, corporate frauds have highlighted the significance of corporate governance in deriving firm performance. By using different sample data, extensive research has examined how corporate governance structure influences firm’s profitability, but limited research was undertaken on the banking sector of Pakistan. This research adds to the literature by testing how board structure derives bank’s performance by using sample data of 19 banks for the period from 2010 to 2017. In addition, the study analyzes the controlling part of size on the link between board governance and bank performance. Findings reveal that banks having small board size, fewer non-executive directors and minimum activity level perform better. Analysis related to bank size illustrates that board size has value in increasing benefits in large size banks in contrast to small size one, while higher participation by board members enhances performance of small size banks more. The correlation results and findings showed that there existed no multicollinearity issue between independent variables. Board size showed positive correlation with the market variable, while board activity tended to correlated negatively with the market performance. Inverse correlation between board size and independent directors indicated that Pakistani banks with greater board size had fewer independent directors.

      • KCI등재

        Determinants and Outcomes of Financial Derivatives: Empirical Evidence from Pakistani Banks

        Atia ALAM,Syeda Fizza ABBAS,Anam ZAHID,Syeda Irtiqa BATOOL,Misbah KHAN 한국유통과학회 2021 The Journal of Asian Finance, Economics and Busine Vol.8 No.4

        The increased risk in financial firms, due to Global Financial Crises and high international trade activities, has encouraged banks to use derivatives for both managing their financial risk and earning non-operating income simultaneously. The present study brings new evidence in the existing literature by determining the drivers behind financial derivative usage in Pakistani banks for 2011 till 2016. Moreover, the paper examines how risk plays a moderating role in determining the relationship between derivative usage and bank value. While assessing the determinants, a two-stage test has conducted, first, the logit regression was used to test the drivers behind the derivative usage in banks. Second, Tobit regression was run to analyze the factors leading to determine the extent of derivative usage. The findings demonstrate that Pakistani banks are using derivatives for both risk management and speculative motive as they are customers and users of derivatives at the same time. Empirical results, regarding moderating role of risk on the value implications of derivative usage, provide mixed findings as derivative usage gives value premium in case of non-systematic risk and foreign exchange risk. Whereas value discounts have been observed for cases where systematic risk is high and managers try to earn non-operating income from speculative activities.

      • SCIESCOPUSKCI등재

        Torque Ripple Minimization for Induction Motor Driven by a Photovoltaic Inverter

        Atia, Yousry The Korean Institute of Power Electronics 2009 JOURNAL OF POWER ELECTRONICS Vol.9 No.5

        The paper presents a new photovoltaic inverter for stand-alone induction motor application. The proposed system is composed of two stages. First stage is for the photovoltaic dc power feeding and second stage is dedicated to the motor-inverter subsystem and control technique. A direct torque control (DTC) with a novel switching strategy for motor torque ripple minimization is introduced. The novel DTC strategy is based on selecting a suitable voltage vector group for motor torque ripple minimization. A three-level voltage source inverter (VSI) is used instead of a two level inverter because the first has more available vectors and lower ripples in the output current and flux than the second, thus it has lower torque ripples. The photovoltaic array and battery bank are sized and the configuration is indicated based on sun-hour methodology. Simulation results show a comparison between three systems; two level VSI with conventional DTC strategy, three level VSI with conventional DTC, and the proposed system that has a novel DTC switching strategy applied to three level VSI. The results show that the proposed system has lower ripples in the current, flux and torque of the motor.

      • SCIESCOPUSKCI등재

        Microcontroller-Based Improved Predictive Current Controlled VSI for Single-Phase Grid-Connected Systems

        Atia, Yousry,Salem, Mahmoud The Korean Institute of Power Electronics 2013 JOURNAL OF POWER ELECTRONICS Vol.13 No.6

        Predictive current control offers the potential for achieving more precise current control with a minimum of distortion and harmonic noise. However, the predictive method is difficult to implement and has a greater computational burden. This paper introduces a theoretical analysis and experimental verification for an improved predictive current control technique applied to single phase grid connected voltage source inverters (VSI). The proposed technique has simple calculations. An ATmega1280 microcontroller board is used to implement the proposed technique for a simpler and cheaper control system. To enhance the current performance and to obtain a minimum of current THD, an improved tri-level PWM switching strategy is proposed. The proposed switching strategy uses six operation modes instead of four as in the traditional strategy. Simulation results are presented to demonstrate the system performance with the improved switching strategy and its effect on current performance. The presented experimental results verify that the proposed technique can be implemented using fixed point 8-bit microcontroller to obtain excellent results.

      • KCI등재

        Green gold@chitosan nanocomposite via solid-state synthesis; a separable catalyst for reduction of Cr(IV)

        Ahmed Atia,Yasser K. Abdel-Monem,A.H. Salama,Salah M. El-kousy,Wael H. Eisa 한국공업화학회 2023 Journal of Industrial and Engineering Chemistry Vol.117 No.-

        A clean and high-throughput synthesis of gold@chitosan nanocomposite using nontoxic oxalic acid as areducing agent was developed. The synthetic route was carried out in completely dry conditions, i.e. solid-state reaction. The gold nanoparticles were bound with chitosan through the hydroxyl and aminogroups, as confirmed by Fourier transform infrared spectroscopic analysis. Scanning and transmissionelectron microscopy imaging confirmed the formation of semi-spherical gold particles with an averagesize of 8–15 nm. The catalytic performance of the synthesized gold nanoparticles for the reduction ofchromium(IV) in the presence of formic acid was evaluated. The film-forming ability of chitosan enabledthe design of separable/reusable heterogeneous catalyst which is convenient for real industrial applications. The proposed solid-state synthetic route could be adapted to produce a wide variety of nanostructuredmaterials that are characterized by high-yield, greenness, and low cost in very simple steps.

      • KCI등재

        Histochemical Localization of Essential Oils and Bioactive Substances in the Seed Coat of the Halophyte Crithmum maritimum L. (Apiaceae)

        Abdallah Atia,Ahmed Debez,Zouhaier Barhoumi,Chedly Abdelly,Abderrazak Smaoui 한국식물학회 2009 Journal of Plant Biology Vol.52 No.5

        Despite seeds and fruits of several halophytes being rich in essential oils and other bioactive substances, the histochemical characterization of these compounds has not received much attention. The aims of the present investigation were to localize the essential oils and the bioactive substances in the seed coat of the oilseed halophyte Crithmum maritimum L. Fruits were collected from the rocky coasts of Tabarka (NW of Tunisia, 36°57′ 12″ N, 08°45′18″ E). C. maritimum L. seed is shown to be surrounded by two envelopes: The first structure is a secretory envelope, consisting in about 20 canals. The second layer represents the endocarp. As revealed by fluorescence and light microscopy, the essential oils, O-dihydroxyphenols and flavonoids, known as bioactive compounds, were accumulated in the canals. The endocarp layer accumulated polysaccharides, O-dihydroxyphenols, and flavonoids. As a whole, these findings highlight the histochemical features and confirm the valuable quality of C. maritimum L. seeds.

      • KCI등재

        Microcontroller-Based Improved Predictive Current Controlled VSI for Single-Phase Grid-Connected Systems

        Yousry Atia,Mahmoud Salem 전력전자학회 2013 JOURNAL OF POWER ELECTRONICS Vol.13 No.6

        Predictive current control offers the potential for achieving more precise current control with a minimum of distortion and harmonic noise. However, the predictive method is difficult to implement and has a greater computational burden. This paper introduces a theoretical analysis and experimental verification for an improved predictive current control technique applied to single phase grid connected voltage source inverters (VSI). The proposed technique has simple calculations. An ATmega1280 microcontroller board is used to implement the proposed technique for a simpler and cheaper control system. To enhance the current performance and to obtain a minimum of current THD, an improved tri-level PWM switching strategy is proposed. The proposed switching strategy uses six operation modes instead of four as in the traditional strategy. Simulation results are presented to demonstrate the system performance with the improved switching strategy and its effect on current performance. The presented experimental results verify that the proposed technique can be implemented using fixed point 8-bit microcontroller to obtain excellent results.

      • KCI등재

        Torque Ripple Minimization for Induction Motor Driven by a Photovoltaic Inverter

        Yousry Atia 전력전자학회 2009 JOURNAL OF POWER ELECTRONICS Vol.9 No.5

        The paper presents a new photovoltaic inverter for stand-alone induction motor application. The proposed system is composed of two stages. First stage is for the photovoltaic dc power feeding and second stage is dedicated to the motor-inverter subsystem and control technique. A direct torque control (DTC) with a novel switching strategy for motor torque ripple minimization is introduced. The novel DTC strategy is based on selecting a suitable voltage vector group for motor torque ripple minimization. A three-level voltage source inverter (VSI) is used instead of a two level inverter because the first has more available vectors and lower ripples in the output current and flux than the second, thus it has lower torque ripples. The photovoltaic array and battery bank are sized and the configuration is indicated based on sun-hour methodology. Simulation results show a comparison between three systems; two level VSI with conventional DTC strategy, three level VSI with conventional DTC, and the proposed system that has a novel DTC switching strategy applied to three level VSI. The results show that the proposed system has lower ripples in the current, flux and torque of the motor.

      • KCI등재

        Perianal Actinomycosis: A Surgeon’s Perspective and Review of Literature

        Alexios Dosis,Atia Khan,Henrietta Leslie,Sahar Musaad,Adrian Smith 대한대장항문학회 2021 Annals of Coloproctolgy Vol.37 No.5

        Actinomycosis is a serious suppurative, bacterial infection caused by the gram-positive anaerobic Actinomyces species. Primary perianal actinomycosis is rare and challenging for the colorectal surgeon. We aimed to present our experience and compare this with available literature. All patients with isolated Actinomyces on microbiology reports, between January 2013 and February 2021, were identified and reviewed. Data collection was retrospective based on electronic patient records. The site of infection and treatment strategy were examined. Perianal cases were evaluated in depth. All publications available in the literature were interrogated. Fifty-nine cases of positive actinomycosis cultures were reviewed. Six cases of colonization were excluded. Actinomyces turicensis was the most common organism isolated. Five cases of perianal actinomycosis were identified requiring prolonged antibiotic and surgical therapy. Twenty-one studies, most case reports, published since 1951 were also reviewed. Diagnosis of perianal actinomycosis may be challenging but should be suspected particularly in recurrent cases. Prolonged bacterial cultures in anaerobic conditions are necessary to identify the bacterium. An extended course of antibiotic therapy (months) is required for eradication in certain cases.

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