Does Okun’s Law and its Coefficient value, β exist? Evidence from Sixteenth South and Southeast Asian Countries during 1991-2020

Abdus Samad(Abdus Samad ) People&Global Business Association 2023 Global Business and Finance Review Vol.28 No.1

Purpose: This paper retested the Okun’s Law established in the 1960s and the subsequent research on Okun’s findings that a 1% increase in unemployment would lead to a 3 % decrease in GDP), i.e. Okun’s coefficient (β)=-3 in diverse economies of sixteen South and Southeast Asia, sixteen countries. Design/methodology/approach: Using panel data in two models, the first difference model: (Yt -Yt-1) = α - β(Ut-Ut-1) and the gap model: (Yt -Y,) = α - β(Ut -U)were estimated. Findings: Results of pool ordinary least square (POLS), Fixed Effect Model (FEM), and Random Effects Model(REM) supports Okun’s Law and shows that the coefficient, β, is (-4.4) suggesting that every 1 percent unemployment rate leads to 4.4 decrease in GDP. The Okun’s coefficient varies with country. The validity of Okun’ coefficient, β= -2 percent, is found only in four. Findings of negative coefficient and its significance provides important policy prescriptions for nine countries. Research limitations/implications: This paper suffers from limitations. First data limitation. This paper used annual data of 30 years. Future research may include quarterly data or annual data with more observations. Second, as Hodrick and Prescott [1997] filtering approach suffers from criticism, Cobb-Douglas production function estimate may be applied for estimating full-employment GDP and natural rate of unemployment. Originality/value: All studies of Okun’s law studies derived its coefficient focused on the economically developed countries, this study is an exception. The survey of literature shows that there is no research of Okun’s for sixteen South and Southeast Asian countries with diverse level of economic growth. So, the result of this study is an important contribution in the literature of Okun’s law. Second, as the policy makers of these countries are facing mounting pressure of unemployment, finding the value of Okun’s coefficient is a contribution of this paper for them.

Diversity of Micro-algae and Cyanobacteria on Building Facades and Monuments in India

Samad, Lakshmi Kumari,Adhikary, Siba Prasad The Korean Society of Phycology 2008 ALGAE Vol.23 No.2

Fifty seven taxa of Cyanobacteria and 15 taxa of Chlorophyta were recorded from the exterior of buildings and rock surfaces of monuments in different regions in India. Four cyanobacteria, e.g. Chroococcidiopsis kashayi, Pseudophormidium indicum, Plectonema puteale and Scytonema geitleri, and the green alga Trentepholia abietina var. tenue occur on the sub-aerial habitats throughout the year. In addition, five other green algae: Chlorococcum infusionum, Scenedesmus arcuatus, Trentepholia aurea, Gloeocystis polydermatica and Printzina effusa, and 18 other cyanobacteria taxa of the genera Chroococcus (5), Asterocapsa (1), Cyanosarcina (2), Gloeocapsa (7), Gloeothece (2) and Scytonema (1) occur on the sub-aerial surfaces enduring extreme temperature and desiccation during summer months of the tropics. During the rainy season, the warm and humid climatic regime coupled with availability of moisture supported an additional ten green algae and 29 cyanobacteria in eight and 17 genera, respectively. The green algal genera Klebsormidium, Stichococcus and Trebouxia, which are dominant in temperate regions, did not occur on the sub-aerial habitats in India, however, species of Gloeocapsa, Chroococcus, Chroococcidiopsis, Phormidium, Leptolyngbya, Nostoc, Scytonema, Chlorella and Trentepholia showed global occurrence in similar habitats.

Surrogate Modeling for Optimization of Dimpled Channel to Enhance Heat Transfer Performance

Samad, A.,Shin, D.-Y.,Kim, K.-Y.,Goel, T.,Haftka, R. T. American Institute of Aeronautics and Astronautics 2007 Journal of thermophysics and heat transfer Vol.21 No.3

A Novel One-Pot Synthesis of Quinoxaline Derivatives in Fluorinated Alcohols

Samad Khaksar,Fariba Rostamnezhad 대한화학회 2012 Bulletin of the Korean Chemical Society Vol.33 No.8

Hexafluoroisopropanol (HFIP) is explored as an effective medium for the synthesis of quinoxaline derivatives in high yields at room temperature. The solvent (HFIP) can be readily separated from reaction products and recovered in excellent purity for direct reuse.

Flow Analyses Inside Jet Pumps Used for Oil Wells

Samad, Abdus,Nizamuddin, Mohammad Korean Society for Fluid machinery 2013 International journal of fluid machinery and syste Vol.6 No.1

Jet pump is one type of artificial lifts and is used when depth and deviation of producing wells increases and pressure depletion occurs. In the present study, numerical analysis has been carried out to analyze the flow behavior and find the performance of the jet pump. Reynolds-averaged Navier Stokes equations were solved and k-${\varepsilon}$ turbulence model was used for simulations. Water and light oil as primary fluids were used to pump water, light oil and heavy oil. The ratios of area and length to diameter of the mixing tube were considered as design parameters. The pump efficiency was considered to maximize for the downhole conditions. It was found that the increase in viscosity and density of the secondary fluid reduced efficiency of the system. Water as primary fluid produced better efficiency than the light oil. It was also found that the longer throat length increased efficiency upto 40% if light oil was used as primary fluid and secondary fluid viscosity was 350 cSt.

Progressive Collapse Resistance of Bolted Extended End-Plate Moment Connections

Samad Barmaki,Mohammad R. Sheidaii,Omid Azizpour 한국강구조학회 2020 International Journal of Steel Structures Vol.20 No.4

When a progressive collapse occurs due to sudden column removal, the moment connections must have adequate strength and be able to bridge over the damaged element. The present study comprehensively investigates the behavior of eight diff erent types of extended end-plate beam-to-column connections against progressive collapse. The proper fi nite element models have been extended to assess the behavior of these bolted connections under a sudden column removal scenario. Specimens were checked by nonlinear analysis method. The fracture modes, Von-Mises stresses, vertical load–displacement and load factor–displacement curves, load transferal mechanisms, and other analytical results comparative were reported in detail and discussed for various investigated beam-to-column connections. The analysis results revealed that the overall failure of the samples occurred in the connection region under the catenary action mode at large displacements. Also, the results were verifi ed with available experimental data. Among all investigated connections, the highest stresses could be applied to the sixteen-bolt stiff ened connection, and this sample had the most excellent behavior. In the design of buildings exposed to unusual loads due to progressive collapse, the signifi cant axial force created in the connections should be considered in the design stages of these elements. Also, it is recommended that at least three rows of bolts are embedded in the bottom area of end-plate connections when the structure is at the risk of progressive collapse.

Computed tomographic assessment of the lacrimal sac fossa in southwest population of Iran

Samad Shahryari,Mohammad Ghasem Hanafi,Rouhangiz Kamankesh,Atefeh Mahdianrad,Ali Reza Eftekhari Moghadam 대한해부학회 2022 Anatomy & Cell Biology Vol.55 No.3

To determine the morphology of the lacrimal sac fossa and bony nasolacrimal duct using computed tomography for obtaining detailed anatomical understanding of the drainage system and utilizing these measurements in planning for dacryocystorhinostomy (DCR) and nasolacrimal duct (NLD) obstruction in normal southwest (SW) population of Iran. One-hundred-sixty-five cases referred for the diagnosis of neuro-ophthalmic conditions were retrospectively studied. Measurements of lacrimal sac fossa were taken on three anatomical sections (upper, middle, and lower planes) utilizing a digital caliper/protractor instrument. Lacrimal thickness and two measurements of maxillary bone thickness were taken at each plane—namely, the “midpoint thickness” and the “maximum thickness.” The anterior extent of the nasal mucosa and NLD width was also evaluated. The mean maximum thickness of the maxillary bone at the three anatomical planes of the lacrimal sac fossa was 4.07 mm, 4.78 mm, and 5.60 mm, respectively. The midpoint thickness of the maxillary bone at each plane was 2.38 mm, 1.99 mm, and 1.68 mm, respectively, in both sexs. The lacrimal bone thickness at each level was 0.76 mm, 0.69 mm, and 0.67 mm, respectively. The proportion of the lacrimal sac fossa comprising the lacrimal bone at lower plane was 43.57% and showed a positive correlation with age (P=0.01). The mean anteroposterior bony nasolacrimal diameter was 5.94 mm with no significant difference between patient sex and age. According to the results, its indicate that performing an osteotomy during DCR could be easier in the Iranian SW population compared to other ethnics.

Superionic and electronic conductivity in monolayer W2C: ab initio predictions

Samad, Abdus,Shafique, Aamir,Kim, Hye Jung,Shin, Young-Han Royal Society of Chemistry 2017 Journal of Materials Chemistry A Vol.5 No.22

<P>Using density functional theory calculations, a freestanding monolayer of W2C in the 2H phase is explored to find its stability in terms of formation energy and phonon vibrations. In addition, the monolayer has a high in-plane stiffness of 278 N m<SUP>−1</SUP>. Its intrinsic metallic nature, high mechanical stability, and high adsorption capability for Li/Na ions make it an appealing anode material for rechargeable Li/Na ion batteries. The anode open circuit voltages of 0.84-0.55 V for Li and 0.88-0.38 V for Na are within the voltage range of commercial anode materials. The low diffusion energy barrier for a Li (0.035 eV) or Na (0.019 eV) ion leads to superionic mobility, which causes ultrafast charge/discharge cycles. The area expansion of the fully loaded anode is negligible. Its high mechanical stiffness, superb ionic and electronic conductivity, and suitable charging voltage range are the indications of a long-life anode having a high recyclability with full recovery and fast charge/discharge processes.</P>

Adsorption and diffusion of mono, di, and trivalent ions on two-dimensional TiS₂

Samad, Abdus,Shafique, Aamir,Shin, Young-Han IOP Pub 2017 Nanotechnology Vol.28 No.17

<P>A comparative study of the monovalent (Li, Na, and K) and multivalent (Be, Mg, Ca, and Al) metal ion adsorption and diffusion on an electronically semi-metallic two-dimensional nanosheet of 1T structured TiS<SUB>2</SUB> is presented here to contribute to the search for abundant, cheap, and nontoxic ingredients for efficient rechargeable metal ion batteries. The total formation energy of the metal ion adsorption and the Bader charge analysis show that the divalent Mg and Ca ions can have a charge storage density double that of the monovalent Li, Na, and K ions, while the Be and Al ions form metallic clusters even at a low adsorption density because of their high bulk energies. The adsorption of Mg ions shows the lowest averaged open circuit voltage (0.13 V). The activation energy barriers for the diffusion of metal ions on the surface of the monolayer successively decrease from Li to K and Be to Ca. Mg and Ca, being divalent, are capable of storing a higher power density than Li while K and Na have a higher rate capability than the Li ions. Therefore, rechargeable Li ion batteries can be totally or partially replaceable by Mg ion batteries, where high power density and high cell voltage are required, while the abundant, cheap, and fast Na ions can be used for green grid applications.</P>

Application of Surrogate Modeling to Design of A Compressor Blade to Optimize Stacking and Thickness

Samad, Abdus,Kim, Kwang-Yong Korean Society for Fluid machinery 2009 International journal of fluid machinery and syste Vol.2 No.1

Surrogate modeling is applied to a compressor blade shape optimization to modify its stacking line and thickness to enhance adiabatic efficiency and total pressure ratio. Six design variables are defined by parametric curves and three objectives; efficiency, total pressure and a combined objective of efficiency and total pressure are considered to enhance the performance of compressor blade. Latin hypercube sampling of design of experiments is used to generate 55 designs within design space constituted by the lower and upper limits of variables. Optimum designs are found by formulating a PRESS (predicted error sum of squares) based averaging (PBA) surrogate model with the help of a gradient based optimization algorithm. The optimum designs using the current variables show that, to optimize the performance of turbomachinery blade, the adiabatic efficiency objective is improved substantially while total pressure ratio objective is increased a very small amount. The multi-objective optimization shows that the efficiency can be increased with the less compensation of total pressure reduction or both objectives can be increased simultaneously.