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Frontiers of Chemical Science and Engineering 2023年第5期17卷 536-547页

作者： Trisita Ghosh Rajkumar Sahoo Suman Kumar Ghosh Pallab Banerji Narayan Ch.Das Rubber Technology Centre Indian Institute of Technology KharagpurKharagpur 721302India Department of Chemistry Indian Institute of Technology KharagpurKharagpur 721302India Materials Science Centre Indian Institute of Technology KharagpurKharagpur 721302India

The past decade has witnessed a variety of members of the carbon family along with exposure of carbon dots due to their magnificent properties in sensing,bioimaging,catalytic applications,biomedical fields,and so ***,we report the simple hydrothermal method to fabricate photoluminescent doped carbon quantum dots for the detection of noxious lead(II)***(II)ion is very venomous for both the environment and human health for which its detection is demanded area in the research *** as-prepared carbon dots show excellent photostability,low toxicity and significant photoluminescence properties along with good water *** with these properties,carbon dots have a quantum yield of approximately 15%.In the practical field of application,these carbon dots have been used as sensing probes for the detection of lead(II)ions with a detection limit of 60 nmol·L^(–1).The fluorescence intensity of carbon dots was remarkably quenched in the presence of the lead(II)ion selectively among all the tested metal ***,we have studied the Stern–Volmer relationship for lead(II)quenching along with the explanation of the probable quenching *** of the doped carbon dots in heavy metal ions sensing in an environmental sample was demonstrated.

关键词： carbon dots fluorescence heavy metal sensing practical application photoluminescence

Seismic behavior of cantilever wall embedded in dry and saturated sand

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Frontiers of Structural and Civil Engineering 2020年第3期14卷 690-705页

作者： Sanku KONAI Aniruddha SENGUPTA Kousik DEB Department of Civil Engineering Indian Institute of Technology KharagpurKharagpur 721302India

The embedded cantilever retaining walls are often required for excavation to construct the undergroundfacilities. Significant numbers of numerical and experimental studies have been performed to understand the behavior ofembedded cantilever retaining walls under static condition. However, very limited studies have been conducted on thebehavior of embedded retaining walls under seismic condition. In this paper, the behavior of a small scale modelembedded cantilever retaining wall in dry and saturated sand under seismic loading condition is investigated by shaketable tests in the laboratory and numerically using software FLAC2D. The embedded cantilever walls are subjected tosinusoidal dynamic motions. The behaviors of the cantilever walls in terms of lateral displacement and bending momentare studied with the variation of the two important design parameters, peak amplitude of the base motions and excavationdepth. The variation of the pore water pressures within the sand is also observed in the cases of saturated sand. Themaximum lateral displacement of a cantilever wall due to seismic loading is below 1% of the total height of the wall in drysand, but in case of saturated sand, it can go up to 12.75% of the total height of the wall.

关键词： embedded cantilever wall shake table test FLAC2D seismic loading,saturated and dry sand

Effect of a less permeable stronger soil layer on the stability of non-homogeneous unsaturated slopes

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Frontiers of Structural and Civil Engineering 2020年第6期14卷 1462-1475页

作者： Nabarun DEY Aniruddha SENGUPTA Department of Civil Engineering Indian Institute of Technology KharagpurKharagpur 721302India

Slope failure occurs due to an increase in the saturation level and a subsequent decrease in matric suction in unsaturated *** paper presents the results of a series of centrifuge experiments and numerical analyses on a 55°inclined unsaturated sandy slope with less permeable,stronger silty sand layer inclusion within *** is observed that a less permeable,stronger silty sand layer in an otherwise homogeneous sandy soil slope hinders the infiltration of *** water content of the slope just above the stronger layer increases significantly,compared to *** shear band is found to initiate in a homogeneous sandy soil slope,whereas for a non-homogeneous slope,they initiate just above the less pervious,stronger layer.A discontinuity of the shear zone is also observed for the case of a non-homogeneous soil *** factor of safety of a non-homogeneous,unsaturated soil slope decreases because of the less permeable,stronger *** decreases significantly if this less permeable,stronger soil layer is located near the toe of the slope.

关键词： non-homogeneous slope stronger soil layer factor of safety centrifuge model test unsaturated soils

Behavior of braced wall embedded in saturated liquefiable sand under seismic loading

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Earthquake Engineering and Engineering Vibration 2021年第2期20卷 361-375页

作者： Sanku Konai Aniruddha Sengupta Kousik Deb Department of Civil Engineering Indian Institute of Technology KharagpurKharagpur 721302India

It is well known that the generation of excess pore water pressure and/or liquefaction in foundation soils during an earthquake often cause structural *** paper describes the behavior of a small-scale braced wall embedded in saturated liquefiable sand under dynamic *** table tests are performed in the laboratory on embedded retaining walls with single *** tests are conducted for different excavation depths and base *** influences of the peak magnitude of the ground motions and the excavation depth on the axial forces in the bracing,the lateral displacement and the bending moments in the braced walls are *** shake table tests are simulated numerically using FLAC 2D and the results are compared with the corresponding experimental *** pore water pressures developed in the soil are found to influence the behavior of the braced wall structures during a dynamic *** is found that the excess pore water pressure development in the soil below the excavation is higher compared to the soil beside the ***,the soil below the excavation level is more susceptible to the liquefaction compared to the soil beside the walls.

关键词： braced wall FLAC 2D liquefaction seismic analysis shake table test

Bearing and uplift capacities of under-reamed piles in soft clay underlaid by stiff clay using lower-bound finite element limit analysis

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Frontiers of Structural and Civil Engineering 2021年第2期15卷 537-551页

作者： Mantu MAJUMDER Debarghya CHAKRABORTY Department of Civil Engineering Indian Institute of Technology KharagpurKharagpur 721302India

Ensuring a safe foundation design in soft clay is always a challenging task to *** the present study,the effectiveness of under-reamed piles in soft clay underlaid by stiff clay is numerically studied using the lower-bound finite element limit analysis(LB FELA).The bearing and uplift capacities of under-reamed piles are estimated through non-dimensional factors N_(cul)and Fcul,*** factors increased remarkably and marginally compared to N_(cul)and Fcul of the piles without bulbs when the bulb is placed in stiff and soft clay,*** a given ratio of undrained cohesion of stiff to soft clay(c_(2)/c_(1)),the factors N_(cul)and Fcul moderately increased with the increase in the length-to-shaft-diameter ratio(Lu/D)and adhesion factors in soft clay(α_(s1))and stiff clay(αs2).The variation of radial stress along the pile-soil interface,distribution of axial force in the under-reamed piles,and state of plastic shear failure in the soil are also studied under axial compression and *** results of this study are expected to be useful for the estimation of the bearing and uplift capacities of under-reamed piles in uniform clay and soft clay underlaid by stiff clay.

关键词： bearing capacity uplift capacity under-reamed pile clay limit analysis

Lightweight convolutional neural network models for semanticsegmentation of in-field cotton bolls

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Artificial Intelligence in Agriculture 2023年第2期8卷 1-19页

作者： Naseeb Singh V.K.Tewari P.K.Biswas L.K.Dhruw Department of Agricultural and Food Engineering IIT KharagpurKharagpur 721302India Department of Electronics and Electrical Communication Engineering IIT KharagpurKharagpur 721302India

Robotic harvesting of cotton bolls will incorporate the benefits of manual picking as well as mechanical harvesting. For robotic harvesting, in-field cotton segmentation with minimal errors is desirable which is a challengingtask. In the present study, three lightweight fully convolutional neural network models were developed for thesemantic segmentation of in-field cotton bolls. Model 1 does not include any residual or skip connections,while model 2 consists of residual connections to tackle the vanishing gradient problem and skip connectionsfor feature concatenation. Model 3 along with residual and skip connections, consists of filters of multiplesizes. The effects of filter size and the dropout rate were studied. All proposed models segment the cotton bollssuccessfully with the cotton-IoU (intersection-over-union) value of above 88.0%. The highest cotton-IoU of91.03% was achieved by model 2. The proposed models achieved F1-score and pixel accuracy values greaterthan 95.0% and 98.0%, respectively. The developed models were compared with existing state-of-the-art networks namely VGG19, ResNet18, EfficientNet-B1, and InceptionV3. Despite having a limited number of trainableparameters, the proposed models achieved mean-IoU (mean intersection-over-union) of 93.84%, 94.15%, and94.65% against the mean-IoU values of 95.39%, 96.54%, 96.40%, and 96.37% obtained using state-of-the-art networks. The segmentation time for the developed models was reduced up to 52.0% compared to state-of-theart networks. The developed lightweight models segmented the in-field cotton bolls comparatively faster andwith greater accuracy. Hence, developed models can be deployed to cotton harvesting robots for real-time recognition of in-field cotton bolls for harvesting.

关键词： Cotton Semantic segmentation Convolutional neural network Robotic harvesting Image segmentation Deep learning

Effect of interface adhesion factor on the bearing capacity of strip footing placed on cohesive soil overlying rock mass

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Frontiers of Structural and Civil Engineering 2021年第6期15卷 1494-1503页

作者： Shuvankar DAS Debarghya CHAKRABORTY Department of Civil Engineering Indian Institute of Technology KharagpurKharagpur 721302India

The problem related to bearing capacity of footing either on pure soil or on pure rock mass has been investigated over the ***,no study deals with the bearing capacity of strip footing on a cohesive soil layer overlying rock ***,by implementing the lower bound finite element limit analysis in conjunction with the second-order cone programming and the power cone programming,the ultimate bearing capacity of a strip footing located on a cohesive soil overlying rock mass is determined in this *** considering the different values of interface adhesion factor(α_(cr))between the cohesive soil and rock mass,the ultimate bearing capacity of strip footing is expressed in terms of influence factor(I _(f))for different values of cohesive soil layer cover ratio(T_(cs)/B).The failure of cohesive soil is modeled by using Mohr−Coulomb yield criterion,whereas Generalized Hoek−Brown yield criterion is utilized to model the rock mass at *** variations of I_(f) with different magnitudes of α_(cr) are studied by considering the influence of the rock mass strength parameters of beneath rock mass *** examine stress distribution at different depths,failure patterns are also plotted.

关键词： bearing capacity soil-rock interface Hoek−Brown yield criterion plasticity limit analysis

Reliability assessment of three-dimensional bearing capacity of shallow foundation using fuzzy set theory

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Frontiers of Structural and Civil Engineering 2021年第2期15卷 478-489页

作者： Rajarshi PRAMANIK Dilip Kumar BAIDYA Nirjhar DHANG Department of Civil Engineering Indian Institute of Technology KharagpurKharagpur 721302India

The aim of this study is to investigate the applicability of reliability theory on surface square/rectangular footing against bearing capacity failure using fuzzy set theory in conjunction with the finite element *** is modeled as a three-dimensional spatially varying medium,where its parameters(cohesion,friction angle,unit weight,etc.)are considered as fuzzy variables that maintain some membership *** is idealized as an elastic-perfectly plastic material obeying the Mohr-Coulomb failure criterion,where both associated and non-associated flow rules are considered in estimating the ultimate bearing capacity of the *** spatial variability of the soil is incorporated for both isotropic and anisotropic fields,which are determined by the values of scales of fluctuation in both the horizontal and vertical directions.A new parameter namely,limiting applied pressure at zero failure probability is proposed,and it indirectly predicts the failure probability of the *** effect of the coefficient of variation of the friction angle of the soil on the probability of failure is analyzed,and it is observed that the effect is ***,the effect of the scale of fluctuation on the probability of failure is investigated,and the necessity for considering spatial variability in the reliability analysis is well proven.

关键词： finite element method square footing reliability analysis fuzzy set theory coefficient of variation spatial variability

Continuously non-malleable codes from block ciphers in split-state model

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Cybersecurity 2024年第2期7卷 68-80页

作者： Anit Kumar Ghosal Dipanwita Roychowdhury Department of Computer Science and Engineering I KharagpurKharagpurWest BengalIndia

Non-malleable code is an encoding scheme that is useful in situations where traditional error correction or detection is impossible to *** ensures with high probability that decoded message is either completely unrelated or the original one,when tampering has no ***,standard version of non-malleable codes provide security against one time tampering *** ciphers are successfully employed in the construction of non-malleable *** construction fails to provide security when an adversary tampers the codeword more than *** non-malleable codes further allow an attacker to tamper the message for polynomial number of *** this work,we propose continuous version of non-malleable codes from block ciphers in split-state *** construction provides security against polynomial number of tampering attacks and it preserves *** the tam-pering experiment triggers self-destruct,the security of continuously non-malleable code reduces to security of the underlying leakage resilient storage.

关键词： Block cipher Non-malleable code Split-state model Tamper-resilient cryptography

Image processing algorithms for in-field cotton boll detection in natural lighting conditions

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Artificial Intelligence in Agriculture 2021年第1期5卷 142-156页

作者： Naseeb Singh V.K.Tewari P.K.Biswas C.M.Pareek L.K.Dhruwa Department of Agricultural and Food Engineering IIT KharagpurKharagpur 721302India Department of Electronics and Electrical Communication Engineering IIT KharagpurKharagpur 721302India

In developing countries,the cotton harvesting operation is currently being performed *** to the monotonous nature of this task and the involvement of a considerable amount of labor,this operation becomes very tedious and *** harvesting robots can be a good alternative for the selective picking of cotton bolls from the *** this study,an attempt has been made to develop the image processing algorithms for in-field cotton boll detection in natural lighting conditions for the cotton harvesting *** image processing algorithms namely color difference,band ratio,YCbCr method,and chromatic aberration were proposed for the real-time segmentation of cotton bolls under natural outdoor light *** performance of developed image processing algorithms was evaluated and the experimental results revealed that the chromatic aberration method outperforms as compared to other developed *** chromatic aberration method showed the highest identification rate of 91.05%with false positive and false negative rates of 6.99%and 4.88%respectively,among all the proposed *** highest sensitivity and specificitywere found to be 81.31%and 97.53%,respectively,using the chromatic aberration ***,the chromatic aberration approach demonstrated a very promising performance for in-field cotton bolls detection under natural lighting conditions which confirms its applicability for the robotic cotton harvesters.

关键词： Cotton recognition Image segmentation Color models Color thresholding