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Awareness of Operational Research in a Developing Country : Focus on Bangladesh
Rahman, Shams-ur,Smith, David K. 한국경영과학회 1990 經營 科學 Vol.7 No.2
Operational Research(OR) is little known in Bangladesh in either the academic or the business areas. However, some OR studies have been carried out in Bangladesh. These studies are scattered in various journals and documents and are not all easily accessible. In this paper an attempt has been made to bring together some of them.
Risk-Informed Design of Hybrid I&C Architectures for Research Reactors
Rahman, Khalil Ur,Kyungho Jin,Gyunyoung Heo IEEE 2016 IEEE transactions on nuclear science Vol.63 No.1
<P>The risk-informed probabilistic design approach toward the hybridized instrumentation and control (I&C) systems of research reactors based on sensitivity and availability criteria has been applied in this paper. An optimized hybrid I&C architecture is worthwhile and emphasized because of low budget for I&C and simple functionality of research reactors. Hybridization in input/output modules using analog and digital components has been introduced to enhance diversity and provide resistance to common mode failures. Based on the approach, two hybrid (named I and II) architecture configurations of reactor protection systems have been formulated from a reference architecture with an analysis performed on their reliability features; availability and sensitivity assessments were performed using Bayesian network models. International Electrotechnical Commission and American Society of Mechanical Engineers criteria have been applied for an evaluation of the architecture reliability features. A novel concept for assessing the sensitivity and risk impact of components based on single and multiple component risk reduction indices have been introduced and used for sensitivity evaluations. It was determined that hybrid-II architectures yielded good reliability features compared to hybrid-I and the reference architecture because the unavailability of hybrid-II architecture decreases by one or two orders of magnitude by just adding one more bi-stable processor based on the risk feedback of hybrid-I architecture. It was concluded that architecture designs based on hybrid and risk-informed design approaches have the ability to maintain high levels of safety and availability through cost-savings.</P>
Fibrin-Enhanced Canonical Wnt Signaling Directs Plasminogen Expression in Cementoblasts
Rahman, Saeed Ur,Park, Chan Ho,Baek, Jeong-Hwa,Ryoo, Hyun-Mo,Woo, Kyung Mi MDPI AG 2017 INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES Vol.18 No.11
<P>Cementum is a mineralized layer on the tooth’s root surface and facilitates the biomechanical anchoring of fibrous connective tissues as a part of tooth-supportive complexes. Previously, we observed that OCCM30 cementoblasts cultured on fibrin matrices underwent apoptosis due to fibrin degradation through the expression of proteases. Here, we demonstrated that OCCM30 on fibrin matrices (OCCM30-fibrin) enhanced canonical Wnt signaling, which directed to plasminogen expression. The OCCM30-fibrin showed higher levels of Wnt3a expression, nuclear translocation of β-catenin, and T-cell factor (TCF) optimal motif (TOP) reporter activity than the cells on tissue culture dishes (OCCM30-TCD), indicating that the OCCM30-fibrin enhanced canonical Wnt/β-catenin signaling. Also, OCCM30-fibrin expressed biomineralization-associated markers at higher levels than OCCM30-TCD, of which levels were further increased with LiCl, a Wnt signaling activator. The OCCM30 cementoblasts simultaneously showed that high levels of plasminogen, a critical component of fibrinolysis, were expressed in the OCCM30-fibrin. Activation of canonical Wnt signaling with LiCl treatment or with forced lymphoid enhancer factor 1 (LEF1)-expression increased the expression of plasminogen. On the contrary, the inhibition of canonical Wnt signaling with siRNAs against Wnt3a or β-catenin abrogated fibrin-enhanced plasminogen expression. Furthermore, there are three conserved putative response elements for the LEF1/β-catenin complex in the plasminogen proximal promoter regions (−900 to +54). Site-directed mutations and chromatin immunoprecipitation indicated that canonical Wnt signaling directed plasminogen expression. Taken together, this study suggests that fibrin-based materials can modulate functional periodontal formations in controlling cementoblast differentiation and fibrin degradation.</P>
Do Roads Enhance Regional Trade? Evidence Based on China's Provincial Data
RAHMAN, Imran Ur,SHARMA, Buddhi Prasad,FETUU, Enitilina,YOUSAF, Muhammad Korea Distribution Science Association 2020 The Journal of Asian Finance, Economics and Busine Vol.7 No.12
We investigate the impact of roads and highways within the provinces on the regional trade of China using the augmented Gravity Model and theory of modeling trade. We take a panel data covering 31 provinces of China over 20 years period (1998-2017) for the estimations. We apply ARMA-OLS model, fixed and random effects, and robust findings by Hausman test. The results imply that road and highway lengths within the provinces have a significantly positive impact on the value of the province-wise exports. The positive impact is due to the fact the increased coverage of roads and highways increase accessibility to resources and mobility of goods and services within the regions. Moreover, employment in the transportation sector, per capita GDP and population of the provinces also illustrate positive and significant influence on regional exports and trade. The impact of China's WTO accession on regional exports has been positive, while the financial crisis has had a negative impact. The year dummies show that, in the years following the financial crisis, China was able to regress from the external shock as trade within the provinces increased. The increase in exports after financial crisis is mainly due to the government policies and support to every province.
Awareness of Operational Research in a Developing Coountry : Focus on Bangladesh
Rahman, Shams-ur,Smith, David K. The Korean Operations Research and Management Scie 1990 經營 科學 Vol.7 No.2
Operational Research (OR) is little in Bangladesh in either the academic or the business areas. However, some OR studies have been carried out in Bangladesh. These studies are scattered in various journals and documents and are not all easily accessible. In this paper an attempt has been made to bring together some of them.
Review of Types, Properties, and Importance of Ferrous Based Shape Memory Alloys
Rahman, Rana Atta Ur,Juhre, Daniel,Halle, Thorsten Materials Research Society of Korea 2018 한국재료학회지 Vol.28 No.7
Shape memory alloys(SMAs) have revolutionized the material engineering sciences as they exhibit exclusive features i.e. shape memory effect(SME) and super-elasticity. SMAs are those alloys that when deform return to their predeformed shape upon heating, they also restore their original shape by removing the load. Research on properties of newly advent of several types of ferrous based shape memory alloys(Fe-SMAs), shows that they have immense potential to be the counterpart of Nitinol(NiTi-SMA). These Fe-SMAs have been used and found to be effective because of their low cost, high cold workability, good weldability & excellent characteristics comparing with Nitinol(high processing cost and low cold workability) SMAs. Some of the Fe-SMAs show super-elasticity. Fe-SMAs, especially Fe-Mn-Si alloys have an immense potential for civil engineering structures because of its unique properties e.g. two-way shape memory effect, super elasticity and shape memory effect as well as due to its low cost, high elastic stiffness and wide transformation hysteresis comparative to Nitinol. Further research is being conducted on SMAs to improve and impinge better attributes by improving the material compositions, quantifying the SMA phase transition temperature etc. In this research pre-existing Fe-SMAs are categorised and collected in a tabulated form. An analysis is performed that which category is mostly available. Last 50 years data of Fe-SMA publications and US Patents is collected to show its importance in terms of increasing research on such type of alloys to invent different compositions and applications. This data is analysed as per different year groups during last 50 years and it was analysed as per whether the keywords exist in title of an article or anywhere in the article. It was found that different keywords related to Fe-SMAs/categories of Fe-SMAs, almost don't exist in the title of articles. However, these keywords related to Fe-SMAs/categories of Fe-SMAs, exist inside the article but still there are not too many publications related to Fe-SMAs/categories of Fe-SMAs.