On the Role of Exports in the Economic Growth of Malaysia : A Multivariate Analysis

Al-Yousif, Yousif. K. 한국국제경제학회 1999 International Economic Journal Vol.13 No.3

합성, 2,4-Diaryl-1,3-selenazoles의 항바이러스 활성도와 반응

Al-Rubaie, Ali Z.,Al-Masoudi, Wasfi A.,Hameed, Ali Jameel,Yousif, Lina Z.,Graia, Mohsen 대한화학회 2008 대한화학회지 Vol.52 No.1

가진 1차 arylselenocarboxylic amide의 고리화는 여러가지 새로운 2,4-diaryl-1,3-selenazoles에 사용되었다. 염소, 브롬, 요오드를 사용한 2,4-diaryl-1,3-selenazoles의 할로겐화는 좋은 수율의 새로운 1,1-dihalo-2,4-diaryl-1,3-selenazoles를 준다. AIDS virus(HIV-1 and HIV-2)에 대하여 몇몇의 1,1-dihalo-2,4-diaryl-1,3-selenazoles의 항바이러스 활성도를 검사하였다. 그것들은 HIV-1에 대한 약간의 대생물활성을 보였다. 모든 화합물은 원소분석, 1H NMR 그리고 질량 분광분석 정보로 구조분석 하였다. 2-(3,4-dimethoxyphenyl)-4-(4-bromophenyl)-1,3-selenazole의 결정구조도 보였다. cyclization of primary arylselenocarboxylic amides with a-bromoketones afforded a variety of new 2,4-diaryl-1,3-selenazoles. Halogenation of the 2,4-diaryl-1,3-selenazoles with chlorine, bromine and iodine gave the new 1,1-dihalo-2,4-diaryl-1,3-selenazoles in good yields. Antiviral activity of some 1,1-dihalo-2,4-diaryl-1,3-selenazoles has been tested against AIDS virus (HIV-1 and HIV-2). They showed some bioactivity against HIV-1. All compounds were characterized by their elemental analysis, 1H NMR and mass spectroscopic data. The crystal structure of 2-(3,4-dimethoxyphenyl)-4-(4-bromophenyl)-1,3-selenazole displays the molecular configuration.

Statistical Analysis of the Anticipated Risks of the Iraqi Stock Market

Yousif Abdullah Abed Al- Ani,Falih Nghaimesh Mutar Zubaidi 대한산업공학회 2021 Industrial Engineeering & Management Systems Vol.20 No.4

This paper analysis the limited effectiveness of the economic role of the Iraqi money market Statistically. There are international challenges and risks that may limit future market activity and cause problems and crises. The research hypothesis was launched from the necessity of interaction between the activity of the Iraqi market for securities and the local financial and economic institutions. Hypothesis has been verified accordingly using Kolmogorov-Smirnov Test, normality test and Heteroscedasticity Test. The statical analysis were based on the three mathematical models to expected the return and risk values of Iraqi money market. The potential exposure to negative effects that could be produced by international crises because of the expected openness. The research reached several conclusions, the most prominent of which is the limited economic role of the Iraqi market for securities. The difficulty of implementing monetary and financial policies, due to vulnerability to international challenges.

Investigating the Effect of Priority in Customer Service in Optimizing the Hierarchical Location-Allocation of Crowded Facilities in the Framework of Queuing Systems

Alim Al Ayub Ahmed,Mohammed Yousif Oudah Al-Muttar,Gunawan Widjaja,Bulatenko Mariya Andreyevna,Trias Mahmudiono,Aditya Halim Perdana Kusuma Putra,Muneam Hussein Ali,A. Heri Iswanto,Skm Mars,Irman Suhe 대한산업공학회 2022 Industrial Engineeering & Management Systems Vol.21 No.2

In this research, the problem of location-hierarchical allocation of crowded facilities has been investigated by consid-ering customers’ priority in serving within the framework of queuing systems. The objective functions of the problem are focused on minimizing the total waiting time of customers and minimizing the maximum unemployment of each facility. The problem model is a multi-objective nonlinear programming model, and to evaluate the efficiency of the model, examples in different dimensions have been solved by a multi-objective genetic algorithm (NSGA-II) based on minimal sorting. Since the performance of meta-heuristic algorithms is highly dependent on their parameters, the parameters of this algorithm are adjusted using the Taguchi design. The results show that the establishment of the priority system has reduced the average waiting time of all customers compared to the shift system, so it can be concluded that if in designing hierarchical facilities, the goal is to reduce the waiting time of a particular class of customers, they should Prioritize.

A Comparative Performance Study of an Ejector-Expansion Refrigeration Cycle Using R134a and its Alternatives: Application of Automobile Air Conditioning

Al-Chlaihawi Kadhim K. Idan,Kadhim Hakim T.,Yousif Ahmad Hashim 대한설비공학회 2021 International Journal Of Air-Conditioning and Refr Vol.29 No.4

In this study, the performance of ejector-expansion refrigeration cycle (EERC) with R134a alternative refrigerants (R152a, R1234yf, R404A, R407C, R507A and R600a) for automobile air-conditioning application is investigated numerically. The ejector is modeled with a constant mixing-pressure assumption taking into consideration the friction effect in the ejector mixing section. The studied refrigerants are compared based on the optimum area ratio, discharge temperature, compressor input power, volumetric cooling capacity, exergy destruction, COP, exergy efficiency and COP improvement. The results show that R152a and R1234yf have the closest performance to R134a and can be considered the most suitable alternative refrigerants for R134a. The COP and exergy efficiency are improved by 2.26% and 2.27%, respectively, using R152a compared to the use of R134a, whereas they are reduced by 2.89% and 2.88% using R1234yf. The volumetric cooling capacity is reduced for both R152a and R1234yf by 6.14% and 6.8%, respectively. In addition, the effect of compressor rotational speed on the performances is reported.

Grant management procedure for energy saving TDM-PONs

Alaelddin, Fuad Yousif Mohammed,Newaz, S.H. Shah,AL-Hazemi, Fawaz,Choi, Jun Kyun Elsevier 2018 Optical fiber technology Vol.40 No.-

<P><B>Abstract</B></P> <P>In order to minimize energy consumption in Time Division Multiplexing-Passive Optical Network (TDM-PON), IEEE and ITU-T have mandated sleep mode mechanism for Optical Network Units (ONUs) in the latest TDM-PON standards (e.g. IEEE P1904.1 SIEPON, ITU-T G.sup45). The sleep mode mechanism is a promising mean for maximizing energy saving in an ONU. An ONU in sleep mode flips between <I>sleep</I> and <I>active state</I> depending on the presence or absent of upstream and downstream frames. To ensure Quality of Service (QoS) of upstream frames, the recent TDM-PON standards introduced an early wake-up mechanism, in which an ONU is forced to leave the <I>sleep state</I> on upstream frame arrival. When the Optical Line Terminal (OLT) of a TDM-PON allows early wake-up of its connected ONUs, it allocates gratuitous grants for the sleeping ONUs along with allocating upstream grants for the ONUs in <I>active state</I>. Note that, the gratuitous grants control message sent periodically by the OLT on Inter-Gratuitous grant Interval (IGI) time. After leaving <I>sleep state</I> due to the arrival of upstream frame, the ONU uses its allocated gratuitous grant to send a control message mentioning the amount of upstream bandwidth (upstream grant) required in order to forward the remaining frames in its buffer. However, the existing early wake-up process of ONU can lead to increase the energy consumption of an ONU. It is because of the ONU wakes-up immediately from the <I>sleep state</I> on arrival of the upstream frame, but even so, it needs to wait for forwarding the frame until its allocated gratuitous grant period, resulting in spending energy unnecessarily. In addition, current energy saving solution for TDM-PONs do not provide a clear solution on how to manage different types of grants (e.g. listening grant, upstream transmission grant) within a Dynamic Bandwidth Allocation (DBA) polling cycle. To address this problem, we propose a state-of-art Grant Management Procedure (GMP) in order to maximize energy saving in a TDM-PON with sleep mode enabled ONUs. GMP contributes in defining the location of the different types of grants during a DBA polling cycle. Furthermore, GMP devises a mechanism so as to allow an ONU to predict its assigned gratuitous grant control message arrival time, thereby allowing an ONU to remain its transceiver unit powered off until the arrival period of the next gratuitous grant control message, increasing the energy saving of the ONU. Results show that, with the increment of IGI, the energy saving performance of an ONU with GMP increases noticeably in compare to a conventional ONU (an ONU that does not use GMP) without imposing any additional upstream frame delay.</P> <P><B>Highlights</B></P> <P> <UL> <LI> First effort dedicated to arrange different types of grants during a DBA cycle. </LI> <LI> We proposed a state-of-art Grant Management Procedure (GMP). </LI> <LI> GMP maximizes the energy saving in TDM-PONs with sleep mode enabled ONUs. </LI> <LI> ONUs utilizing GMP can predict gratuitous grant control message arrival time. </LI> </UL> </P>

A review on the advancements in the development of vaccines to combat coronavirus disease 2019

Helen Onyeaka,Zainab T. Al-Sharify,Maryam Yousif Ghadhban,Shahad Z. Al-Najjar 대한백신학회 2021 Clinical and Experimental Vaccine Research Vol.10 No.1

Coronavirus disease 2019 (COVID-19), the deadly disease caused by SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2) is a global pandemic that has severely affected lives and economies around the globe. The spread of this virus will be very difficult to contain if no vaccine is ready for implementation. This is because of the high human-to-human transmission rate of this virus and the fact that the virus is in the community spread stage. As of 31st August 2020, 25.3 million individuals have been affected by this deadly virus resulting in about 850,673 deaths. To combat the spread of COVID-19, more than 100 applicant immunizations are being developed around the world. Among them, eight have begun or will be soon beginning preliminary clinical trials. This paper provides a review of the current developments of potential COVID-19 vaccines around the world. It specifically discusses the recombinant vaccine produced by the University of Oxford and AstraZeneca (Cambridge, UK), the use of novel self-amplifying RNA technique to create a vaccine and the progress made by UNAID (US National Institute of Allergy and Infectious Diseases) and World Health Organization (WHO). Furthermore, this review demonstrates the pharmaceutical prophylaxis and treatment protocols for COVID-19 by analysing the documentation set up by the WHO for up to date data with respect to the novel coronavirus of 2019–2020.

Filter orthogonal frequency-division multiplexing scheme based on polar code in underwater acoustic communication with non-Gaussian distribution noise

Ahmed, Mustafa Sami,Shah, Nor Shahida Mohd,Al-Aboosi, Yasin Yousif,Gismalla, Mohammed S.M.,Abdullah, Mohammad F.L.,Jawhar, Yasir Amer,Balfaqih, Mohammed Electronics and Telecommunications Research Instit 2021 ETRI Journal Vol.43 No.2

The research domain of underwater communication has garnered much interest among researchers exploring underwater activities. The underwater environment differs from the terrestrial setting. Some of the main challenges in underwater communication are limited bandwidth, low data rate, propagation delay, and high bit error rate (BER). As such, this study assessed the underwater acoustic (UWA) aspect and explored the expression of error performance based on t-distribution noise. Filter orthogonal frequency-division multiplexing refers to a new waveform candidate that has been adopted in UWA, along with turbo and polar codes. The empirical outcomes demonstrated that the noise did not adhere to Gaussian distribution, whereas the simulation results revealed that the filter applied in orthogonal frequency-division multiplexing could significantly suppress out-of-band emission. Additionally, the performance of the turbo code was superior to that of the polar code by 2 dB at BER 10-3.

Dynamic response of reinforced concrete members incorporating steel fibers with different aspect ratios

Haido, James H.,Abdul-Razzak, Ayad A.,Al-Tayeb, Mustafa M.,Bakar, B.H. Abu,Yousif, Salim T.,Tayeh, Bassam A. Techno-Press 2021 Advances in concrete construction Vol.11 No.2

Investigations on the dynamic behavior of concrete members, incorporating steel fibers with different aspect ratios, are limited so far and do not covered comprehensively in prior studies. Present endeavor is devoted to examine the dynamic response of the steel fibrous concrete beams and slabs under the influence of impact loading. These members were reinforced with steel fibers in different length of 25 mm and 50 mm. Four concrete mixes were designed and used based on the proportion of long and short fibers. Twenty-four slabs and beams were fabricated with respect to the concrete mix and these specimens were tested in impact load experiment. Testing observations revealed that the maximum dynamic deflection or ductility of the member can be achieved with increasing the fiber length. Structural behavior of the tested structures was predicted using nonlinear finite element analysis with specific material constitutive relationships. Eight nodes plate elements have been considered in the present dynamic analysis. Dynamic fracture energy of the members was calculated and agreement ratio, of more than 70%, was noticed between the experimental and analysis outcomes.

Effect of pile group geometry on bearing capacity of piled raft foundations

Mohammed Y. Fattah,Mustafa A. Yousif,Sarmad M.K. Al-Tameemi 국제구조공학회 2015 Structural Engineering and Mechanics, An Int'l Jou Vol.54 No.5

This is an experimental study to investigate the behaviour of piled raft system in different types of sandy soil. A small scale “prototype” model was tested in a sand box with load applied to the foundation through a compression jack and measured by means of load cell. The settlement was measured at the raft by means of dial gauges, three strain gauges were attached on piles to measure the strains and calculate the load carried by each pile in the group. Nine configurations of group (1×2, 1×3, 1×4, 2×2, 2×3, 2×4, 3×3, 3×4 and 4×4) were tested in the laboratory as a free standing pile group (the raft not in contact with the soil) and as a piled raft (the raft in contact with the soil), in addition to tests for raft (unpiled) with different sizes. It is found that when the number of piles within the group is small (less than 4), there is no evident contribution of the raft to the load carrying capacity. The failure load for a piled raft consisting of 9 piles is approximately 100% greater than free standing pile group containing the same number of piles. This difference increases to about 4 times for 16 pile group. The piles work as settlement reducers effectively when the number of piles is greater than 6 than when the number of piles is less than 6. The settlement can be increased by about 8 times in (1×2) free standing pile group compared to the piled raft of the same size. The effect of piled raft in reducing the settlement vanishes when the number of piles exceeds 6.