On Multi Query Optimization Algorithms Problem

Muhammad, L. J.,Yahaya Bala Zakariyau,Abdullahi Garba Ali,Abba Garba 보안공학연구지원센터 2014 International Journal of Database Theory and Appli Vol.7 No.6

Without multi query optimization, Relational Database Management System for online and analytical decision support systems would have been inefficient and hence unpractical. It is an expensive process because it relies at a great extent on evaluating the different plans (access paths) and choosing an optimal one among them. In Multi Query Optimization, queries are executed in batches and there were many different algorithms acted in such way that, in case some queries have a common sub-expression such a sub- expression is executed once and the output shared. We studied the basic multi query optimization algorithms including Basic Volcano, Volcano-SH and Volcano RU, identified their strengths and weaknesses and recommend strategies for developing new improved multi query optimization algorithm so as to reduce weaknesses and integrate strengths of the different basic multi query algorithms into one efficient algorithm.

Efficient Algorithm for Multi Query Optimization

L. J. Muhammad,Yahaya Bala Zakariyau,Abdullahi Garba Ali 보안공학연구지원센터 2015 International Journal of Database Theory and Appli Vol.8 No.6

Multi Query Optimization is an important process in database and it becomes the commonplace due to the frequent usage of decision support systems in almost all the multinational enterprises. The multiple queries from different users that have been addressed to one schema often have a lot of common sub-expressions and it is the function of the multi query optimization algorithms such as Basic Volcano, Volcano RU and Volcano SH algorithms to optimize such multiple queries together and executes the common operation once and share the output among the queries. In this work, a multi query shareability algorithm which can efficiently detect the common sub- expressions among the multiple queries and share the output among those queries was proposed and algorithm for optimal order of those queries was also proposed. The Algorithm has a time complexity of O(n2 + 9n +6) while the most recent basic algorithm thus Volcano RU Algorithm has O(2n2 +20n +12), both the algorithms have O(n2) time complexity which is quadratic in nature. However, the Proposed Algorithm is more efficient and better than Volcano RU algorithm even if n approach to infinity.

Multi Query Optimization Algorithm Using Semantic and Heuristic Approaches

L. J. Muhammad,Abdullahi Garba Ali,Yahaya Bala Zakariyau,Ibrahim A. Mohammed 보안공학연구지원센터 2016 International Journal of Database Theory and Appli Vol.9 No.6

Multi Query Optimization is one of the most important tasks in Relational Database Management System (RBMS) and it becomes common due to high usage of online decision support management systems in every industry nowadays. In multi query optimization, queries are optimized and executed in batches. However, there are many algorithms use to detect and unified common sub-expressions among multiple queries and unified them so that the more encompassing sub- expression is executed and the other sub-expressions are derived from. In this work, multi-query optimization algorithm using heuristics and semantic approaches was proposed and encoded on SQL Server version 10.0.1600 and three queries were used for the experiment between the proposed algorithm and most recent basic Multi Query Optimization Algorithm (Volcano RU). The result of experiment showed that, Proposed Algorithm gave the best plans compared Volcano RU Algorithm, across all three queries and was best for all queries in terms of execution time and CPU time.

Leadership as a Driver of Employees’ Innovation Performance: The Mediating Effect of Cultural Diversity in UAE Universities

Tariq Humaid ALMASKARI,Effendi MOHAMAD,Siti Norbaya YAHAYA,Muhammad Farhan JALIL 한국유통과학회 2021 The Journal of Asian Finance, Economics and Busine Vol.8 No.8

The aim of this research was to look into the relationship between leadership; transformational leadership, transactional leadership, and employee innovation, as well as the mediating impact of cultural diversity between leadership and employee innovation. Structured questionnaire was used to collect the data from 633 public and private universities’ employees in the United Arab Emirates (UAE) with the help of the stratified sampling technique, and hypothesis verified through structural equations modelling (AMOS-21). Findings of the study shows that leadership has positive impact on employee innovation and cultural diversity partially mediates the relationship between leadership and innovative performance of UAE universities’ employees. Practical implication of the study is to understand how universities can enhance their employees’ innovation which is crucial for their competitiveness and survival. Moreover, the increasing prevalence of cultural diversity, as work arrangements in universities, raises the question of how to successfully manage employees. Although few studies have looked into how transformational and transactional leadership styles affect employees’ innovation performance, this study expands on the topic by concentrating on sub-dimensions of leadership that foster innovation through idea generation and execution at the United Arab Emirates universities. This study offers valuable insights for educational leaders and throws light on the main characteristics of leadership which helps the employees to perform better in terms of innovation.

The Influence of Transformational Leadership on Employees’ Innovation in Universities of UAE: Mediating Effect of Technological Diversity

Tariq Humaid ALMASKARI,Effendi MOHAMAD,Siti Norbaya YAHAYA,Muhammad Farhan JALIL 한국유통과학회 2021 The Journal of Asian Finance, Economics and Busine Vol.8 No.7

This study seeks to empirically investigate the impact of transformational leadership on employees’ innovation with the mediating effect of technological diversity. Employees have evolved into leaders in organizing work within institutions over the last few decades. This shift presents new demands for leaders, who are forced to reinvent individual workers while also improving workplace innovation. This research proposes a conceptual model for considering transformational leadership and the impact of technological diversity on innovation. Structured questionnaire is used in the study and the analysis of the data from 633 employees of universities in the United Arab Emirates uses stratified sampling technique and hypotheses verified through Structural Equations Modelling (AMOS-21). According to the results, transformational leadership has a big effect on employees’ innovation. Furthermore, in the relationship between transformational leadership and workforce innovation, technological diversity has a partial mediation impact. This research adds to the growing body of knowledge about how transformational leadership influences employees’ innovation and how it affects employees’ success, especially in the context of UAE-based universities. Overall, this research contributes to the previous studies wherein transformational leadership plays a critical role in influencing the innovative performance of employees and that, in turn, will promote diversification of technology in the organization.

Intravenous Leiomyomatosis Extending from the Uterus to the Heart

Mohd Yusof Mubarak,Awang Ramli Kama Azira,Yahaya Zainab,Ghapar Abd Kahar,Mohamed Dani Noordini,Ismail Hamidah,Muhammad Nor Mohamad Arif,Leman Hamdan,Mohammed Yusri 아시아심장혈관영상의학회 2019 Cardiovascular Imaging Asia Vol.3 No.2

We report a case of intravenous leiomyomatosis with right atrium extension through the left gonadal vein, left renal vein and inferior vena cava. The tumor moved in and out of the right ventricle via the tricuspid valve, which could lead to valve obstruction and sudden death. We illustrate the importance of multimodality cardiac imaging to diagnose this condition by performing echocardiography, cardiac magnetic resonance imaging and computed tomography.

Optical gas sensing selectivity property of ruthenium (II)-metalloporphyrins Langmuir?Blodgett films

Akrajas Ali Umar,Muhamad Mat Salleh,Muhammad Yahaya 한국물리학회 2008 Current Applied Physics Vol.8 No.1

This paper reports the study of the selectivity property of a metalloporphyrins derivative LangmuirBlodgett thin lm,n-octaethylporphine ruthenium (II) carbonyl (RuOEPCO), to several organic gas samples, namely the saturated vapor of acetone, 2-propanol, eth-anol and cyclohexane. The sensing sensitivity was based on the change in the optical property of the lm upon exposure to the gas sam-k = 514 nm, of the light source. It was observed that the thin lm exhibited excellentselectivity property to the gas samples by presenting clear dierences amongst its responses. The selectivity property of the thin lm wasfound to depend on the structure of the gaseous molecules of which the highest sensitivity was shown for the gaseous molecules withplanar structure, such as cyclohexane. The mechanism for the thin lms-gas interaction that promotes the selectivity characteristic is proposed.

Controlled Release Electrochemical Synthesis and Cytotoxicity Study of Copper(II) Nanoparticles in Copper(II) Decanoate Complex

Norazzizi Nordin,Wan Zurina Samad,Egi Kardia,Badrul Hisham Yahaya,Muhammad Rahimi Yusop,Mohamed Rozali Othman 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2018 NANO Vol.13 No.5

In the present study, a controlled release electrochemical (CRE) technique based on the controlled release of Cu2+ ion from Cu anode in the presence of decanoic acid (HDe) has been used to synthesize Cu(II) decanoate (CuDe2) complex. The effect of applied voltages (1–10 V) and electrolyte concentrations (0.1–2.0M CH3COONH4) during the electrolysis on the nanoparticles obtained was studied using TEM. The results reveal that small-sized nanoparticles (2ffi1 nm) were obtained by using lowest applied voltage and CH3COONH4 concentration (1V and 0.1M, respectively). The smallest nanoparticle obtained was then used in the cytotoxicity study against A549 and HeLa cells. The synthesized complex gives moderate cytotoxic effect on the selected cells (IC50 = 15.85 μM and 20.89 μM, respectively) and low cytotoxic effect on normal cells (IMR90). Apoptosis is the mode of cell death based on the apoptosis assay that has been conducted.

Dengue Virus is Hyperendemic in Nigeria from 2009 to 2020: A Contemporary Systematic Review

Anthony Uchenna Emeribe,Idris Nasir Abdullahi,Idongesit Kokoabasi Isong,Anthony Ogbonna Emeribe,Justin Onyebuchi Nwofe,Buhari Isa Shuaib,Abubakar Muhammad Gwarzo,Yahaya Usman,Madjid Sadi,Chikodi Modes 대한감염학회 2021 Infection and Chemotherapy Vol.53 No.2

Backround: Data on Dengue virus (DENV) infection prevalence, geographic distribution and risk factors are necessary to direct appropriate utilization of existing and emerging control strategies. This study aimed to determine the pooled prevalence, risk factors of DENV infection and the circulating serotypes within Nigeria from January 1, 2009 to December 31, 2020. Materials and methods: Twenty-one studies out of 2,215 available articles were eligible and included for this systematic review. Relevant articles were searched, screened and included in this study according to the Preferred Reporting Items for Systematic reviews and MetaAnalyses (PRISMA) criteria. The risk of bias in primary studies was assessed by Cochrane's method. Heterogeneity of pooled prevalence was calculated using the chi-square test on Cochrane's Q statistic, which was quantified by I-square values. The random-effects analyses of proportions were used to determine the pooled prevalence of DENV antibodies, antigen and RNA from eligible studies. Results: Of these, 3 studies reported co-circulation of all the 4 serotypes, while 2 separately reported co-circulation of DENV-1 &2 and DENV-1 to -3. All the antibody-based studies had significantly high heterogeneity (I2 >90%, P <0.05), while the NS1 and PCR-based studies had low heterogeneity (I2 <25%, P >0.05). The pooled prevalence of DENV IgM, IgG, RNA, NS1 and neutralizing antibodies were 16.8%, 34.7%, 7.7%, 7.7% and 0.7%, respectively. Southeast Nigeria had the highest pooled DENV-IgG seropositivity, 77.1%. Marital status, gender, educational level and occupation status, the proximity of residence to refuse dumpsite, frequent use of trousers and long sleeve shirts were significantly associated with DENV IgG seropositivity (P <0.05). Conclusion: Based on these findings, it can be inferred that Nigeria is hyperendemic for Dengue fever and needs concerted efforts to control its spread within and outside the country.

A Simple Approach Low-Temperature Solution Process for Preparation of Bismuth-Doped ZnO Nanorods and Its Application in Hybrid Solar Cells

Ginting, Riski Titian,Lee, Hock Beng,Tan, Sin Tee,Tan, Chun Hui,Jumali, Mohd. Hafizuddin Hj.,Yap, Chi Chin,Kang, Jae-Wook,Yahaya, Muhammad American Chemical Society 2016 The Journal of Physical Chemistry Part C Vol.120 No.1

<P>A simple low-temperature solution processed bismuth-doped ZnO nanorods (NRs) and poly(3-hexylthiophene) (P3HT) were used as electron acceptor and donor, respectively, in a hybrid inorganic-organic photovoltaic system. Controlling Bi precursor concentration via solution processing (hydrothermal method) plays an important role in altering the morphology, structure, and intrinsic defects of ZnO NRs. Interstitial doping of BiBi2O3 into ZnO (BiZO) NRs results in simultaneous improvement of the open circuit voltage and short circuit current density primarily due to prolonged charge carrier recombination lifetime, increased donor-acceptor interfacial areas with efficient exciton dissociation, and charge carrier mobility. As a result, the power conversion efficiency of the 2 wt % BiZO NRs-P3HT device was significantly enhanced by 55% compared with that of the pristine device. Overall, our study highlighted the immense potential of BiZO NRs as an excellent electron acceptor for fabrication of hybrid optoelectronic devices.</P>