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Earthquake Engineering and Engineering Vibration 2023年第1期22卷 135-156页

作者： Swagata DebRoy rajib saha Civil Engineering Department National Institute of Technology AgartalaJirania-799046Tripura(West)India

Seismic failure of structures supported on pile foundation has revealed the importance of seismic soil-foundation-structure interaction(SSFSI)for ensuring safe *** uncertainties in subsoil properties and seismic loading may lead the problem to be more *** this context,the present study attempts to assess the seismic reliability of pile foundation-supported building structure embedded in inhomogeneous clay layer considering inertial *** strength of clay and earthquake loading is considered as spatially variable uncertain parameters.A non-linear soil-pile-structure system was assumed,and Monte Carlo simulation(MCS)was adopted to obtain probabilistic response of the ***-order reliability method(FORM)is used for reliability *** study indicates significant influence of uncertain parameters on the seismic response of building ***,the influence of material and load uncertainty parameters on the probabilistic seismic response of structure designed following older version of code is higher than counterpart structure designed following recent *** based reliability analysis infers thatserviceability criterion may be the governing parameter for pile foundation ***,the study also indicates that the curvature ductility demand of pile may be considered another crucial design parameter to assess the reliability of pile foundation.

关键词： seismic soil-foundation-structure interaction pile foundation soft clay Monte Carlo simulation FORM OPENSees

Influence of dynamic soil-pile raft-structure interaction:an experimental approach

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Earthquake Engineering and Engineering Vibration 2015年第4期14卷 625-645页

作者： rajib saha Sumanta Haldar Sekhar Chandra Dutta Civil Engineering Department National Institute of Technology Agartala School of Infrastructure Indian Institute of Technolgy Bhubaneswar Department of Civil Engineering Indian School of Mines

Traditionally seismic design of structures supported on piled raft foundation is performed by considering fixed base conditions, while the pile head is also considered to be fixed for the design of the pile foundation. Major drawback of this assumption is that it cannot capture soil-foundation-structure interaction due to flexibility of soil or the inertial interaction involving heavy foundation masses. Previous studies on this subject addressed mainly the intricacy in modelling of dynamic soil structure interaction (DSSI) but not the implication of such interaction on the distribution of forces at various elements of the pile foundation and supported structure. A recent numerical study by the authors showed significant change in response at different elements of the piled raft supported structure when DSSI effects are considered. The present study is a limited attempt in this direction, and it examines such observations through shake table tests. The effect of DSSI is examined by comparing dynamic responses from fixed base scaled down model structures and the overall systems. This study indicates the possibility of significant underestimation in design forces for both the column and pile if designed under fixed base assumption. Such underestimation in the design forces may have serious implication in the design of a foundation or structural element.

关键词： soil-foundation-structure interaction piled raft foundation base shear pile head shear model test

Gender Disparity in Second Language Learning： Reality or Illusion？

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Sino-US English Teaching 2016年第11期13卷 860-868页

作者： Syed Md Golam Faruk rajib saha Directorate of Secondary and Higher Education Chittagong Bangladesh Chittagong City Corporation Premier College Chittagong Bangladesh

The paper draws a comparison between female and male students＇ language learning capabilities in the backdrop of age-old idea that males are better than females in language learning on the one hand, and some recent study findings indicating females＇ superiority over males on the other. To this end, 43 female and 80 male higher secondary students＇ 468 answer scripts of their regular English exams were collected. For the traditional question pattern, the collected data could measure only ＂remembering＂ and ＂understanding＂ of the examinees. Therefore, the students were compared only on the basis of these two lowest levels of Bloom＇s taxonomy. The participants were of same age, studying at the same level （Grade 11）, and were taught by the same teacher. The study finds that if other variables remain the same, there is no essential difference between male and female regarding learning English as a second language.

关键词： female students male students learning English as a second language Bloom's taxonomy Bangladesh

采用二冷轧及退火工艺获得深冲无皱耳的Ti＋Nb无间隙原子钢

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现代冶金（内蒙古） 2013年第2期 51-53页

作者： rajib saha[印度] 冯岩青(译) 安琪(校)

冷轧及退火后的Ti＋Nb无间隙原子钢经二次冷轧及退火后γ-纤维强度及γ-纤维一致性明显提高。γ-纤维中的两个主要成分{111}〈112〉和{111}〈110〉晶粒尺寸一致数量相当，使得该材料得到高深冲性能和无起皱现象。

关键词：无间隙原子钢(IF) 织构显微组织晶界特征分布二次冷轧及退火(DRDA)

Thirty Years of Science,Technology,and Academia in Disaster Risk Reduction and Emerging Responsibilities

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International Journal of Disaster Risk Science 2020年第4期11卷 414-425页

作者： rajib Shaw Graduate School of Media and Governance Keio UniversityFujisawa 252-0882Japan

The 1990 initiation of the International Decade for Natural Disaster Reduction marked its 30th year in *** three decades since then have seen significant developments in science and technology and their incorporation into the decision making in the field of disaster risk *** disasters that have occurred during that time have enhanced the importance of the field,and new research and innovations have *** article summarizes this evolution through the review of specific *** the Sendai Framework for Disaster Risk Reduction 2015–2030 provides opportunities for synergies with the sustainable development agenda,the science and technology communities have also changed their roles from advisory to co-designing and co-delivering *** education plays an important role in developing new generations of professionals,and the role of thematic incubation in higher education institutions is highlighted along with the development of the professional society in disaster risk *** evolution from Society 4.0(information age)to Society 5.0 will see an enhanced role of the technology-driven approach in disaster risk reduction,while traditional knowledge and indigenous technologies still remain valid for *** and science communities need to be more sensitive to changing the“last mile”concept to“first mile”thinking with respect to the users’needs and perspectives.

关键词： Co-design solutions in disaster risk reduction Professional society Science and technology in disaster risk reduction Society 5.0

Enhancing modelling accuracy of cascaded spline adaptive filters using the remora optimisation algorithm: application to real-time systems

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Frontiers of Information Technology & Electronic Engineering 2024年第11期25卷 1515-1535页

作者： Janjanam, Lakshminarayana saha, Suman Kumar Kar, rajib JNTUK Recognized Research Center Department of Electronics & Communication Engineering Sasi Institute of Technology & Engineering Tadepalligudem India Department of Electronics & Communication Engineering National Institute of Technology Raipur India Department of Electronics & Communication Engineering National Institute of Technology Durgapur India

We first introduce a new approach for optimising a cascaded spline adaptive filter (CSAF) to identify unknown nonlinear systems by using a meta-heuristic optimisation algorithm (MOA). The CSAF architecture combines Hammerstein and Wiener systems, where the nonlinear blocks are implemented with the spline network. The algorithms used optimise the weights of the spline interpolation function and linear filter by using an adequately weighted cost function, leading to improved filter stability, steady state performance, and guaranteed convergence to globally optimal solutions. We investigate two CSAF architectures: Hammerstein–Wiener SAF (HW-SAF) and Wiener–Hammerstein SAF (WH-SAF) structures. These architectures have been designed using gradient-based approaches which are inefficient due to poor convergence speed, and produce suboptimal solutions in a Gaussian noise environment. To avert these difficulties, we estimate the design parameters of the CSAF architecture using four independent MOAs: differential evolution (DE), brainstorm optimisation (BSO), multi-verse optimiser (MVO), and a recently proposed remora optimisation algorithm (ROA). In ROA, the remora factor’s control parameters produce near-global optimal parameters with a higher convergence speed. ROA also ensures the most balanced exploration and exploitation phases compared to DE-, BSO-, and MVO-based design approaches. Finally, the identification results of three numerical and industry-specific benchmark systems, including coupled electric drives, a thermic wall, and a continuous stirred tank reactor, are presented to emphasise the effectiveness of the ROA-based CSAF design.

关键词： Cascaded spline adaptive filter Nonlinear system identification Remora optimisation algorithm

Seismic bearing capacity of strip footing on partially saturated soil using modal response analysis

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Earthquake Engineering and Engineering Vibration 2022年第3期21卷 641-662页

作者： Abhijit Anand rajib Sarkar Department of Civil Engineering IIT(ISM)DhanbadDhanbad 826004India

The present study proposes a novel and simplified methodology to assess the seismic bearing capacity(SBC) of a shallow strip footing by incorporating strength non-linearity arising due to partial saturation of a soil matrix. Furthermore, developed methodology incorporates the modal response analysis of soil layers to assess SBC. A constant matric suction distribution profile has been considered throughout the depth of the soil. The Van Genuchten equation and corresponding fitting parameters have been considered to quantify matric suction in the analysis. SBC has been obtained for three different geomaterials;viz. sand, fly ash and clay, based on their predominant grain size and diverse soil water characteristics curve(SWCC) attributes. Variation of SBC with different modes of vibration and damping ratio are reported for ranges of matric suction pertinent to the geomaterials considered in the study. The relative significance of matric suction on SBC has been reported for suction values within the transition zone of each geomaterial. It is observed that the SBC of sand is drastically reduced, with matric suction reaching beyond the residual suction value. The SBC of fly ash remains constant beyond the residual suction value, whereas the SBC of clay shows an increasing trend toward the practical range of matric suction values.

关键词： seismic bearing capacity modal analysis matric suction

Seismic behavior of batter pile groups embedded in liquefiable soil

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Earthquake Engineering and Engineering Vibration 2021年第3期20卷 583-604页

作者： J.S.Rajeswari rajib Sarkar Department of Civil Engineering Indian Institute of Technology(ISM)DhanbadDhanbad 826004India

A comparative study of the seismic performance of 2×1 pile groups considering different degrees of batter(0°for vertical,10°and 20°)embedded in single homogeneous liquefiable sand through fully coupled three-dimensional dynamic analyses is *** effects of inertial interaction are considered with structures having two different *** performance of pile groups is investigated for the fixed and pinned pile to cap connections for both floating and end bearing types of pile *** ratios of piles were also varied to enable a comprehensive *** have been carried out for three earthquake motions having varied dominant *** is observed that batter pile groups in liquefiable soils provide beneficial effects on piles and superstructure responses for both fixed and pinned head pile to cap connections for long period ***,for short period structures,a beneficial effect is most evident for fixed head connection.

关键词： batter pile liquefaction period of structure pile to cap connection slenderness ratio

ON SOLUTION TO THE NAVIER-STOKES EQUATIONS WITH NAVIER SLIP BOUNDARY CONDITION FOR THREE DIMENSIONAL INCOMPRESSIBLE FLUID

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Acta Mathematica Scientia 2019年第6期39卷 1628-1638页

作者： Subha PAL rajib HALOI Department of Mathematical Sciences Tezpur University

In this article, we prove the existence and uniqueness of solutions of the NavierStokes equations with Navier slip boundary condition for incompressible fluid in a bounded domain of R^3. The results are established by... 详细信息

关键词： Navier-Stokes equations Galerkin method Navier slip boundary condition strain tensor

Perceptive insight into incentive design and sustainability of participatory mangrove management: a case study from the Indian Sundarbans

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Journal of Forestry Research 2017年第4期28卷 815-829页

作者： Rajarshi DasGupta rajib Shaw International Environment & Disaster Management Research Group Graduate School of Global Environmental StudiesKyoto UniversityYoshida HonmachiSakyo-kuKyoto 606-8501Japan

Incentive design is among the decisive factors behind active community participation and long-term sustainability of participatory forest management. Especially in case of mangroves, where multiple interests apply, it requires a careful integration of several ecological, economic and institutional factors. The primary objective of this paper is to understand the basis of incentive design and make a comprehensive inquiry into the existing incentive mechanism of participatory mangrove management in Indian Sundarbans. The qualitative and in-depth assessment was derived against a conceptual framework that contains three main determinants: (1) resources availability, (2) control mechanism, and (3) perception of end-users. The study deploys the results of various participatory exercises such as structured interviews with forest officials, focus group discussions with 10 Joint Forest Management Committees and semi-structured interviews with 119 mangrove users. In general, we observed an over-cautious, hierarchical and safety-margin-based incentive design with distinct bifurcation of communities over the adequacy and effectiveness of derived benefits. Although, the incentives are diverse and align well with the overall conservation of mangroves, they are considered to be insufficient by nearly half of the mangrove users. The main issues that were observed to hinder effective community participation can be summarized as (1) serious restrictions on access to economically exploitable mangrove products, (2) passive involvement of vulnerable occupational groups, and (3) lack of trust and conflicting interests between the officials and the communities. Although the existing preventive management of mangroves can be justified considering the magnanimity of the Indian Sundarbans, it can severely impair community participation and emerge as a clear threat to future sustainability. To secure greater participation of the communities, we propose small scale, innovative developmental in

关键词： Mangrove conservation Community based mangrove management Joint forest management Community perception