A Survey on Content Aware Image Resizing Methods

( Ankit Garg ),( Ashish Negi ) 한국인터넷정보학회 2020 KSII Transactions on Internet and Information Syst Vol.14 No.7

With the advancement in the field of image processing, images are being processed using various image processing algorithms. Nowadays, many efficient content-aware image resizing techniques are being used to safeguard the prominent regions and to generate better results that are visually appealing and pleasing while resizing. Advancements in the new display device with varying screen size demands the development of efficient image resizing algorithm. This paper presents a survey on various image retargeting methods, comparison of image retargeting results based on performance, and also exposes the main challenges in image retargeting such as content preservation of important regions, distortion minimization, and improving the efficiency of image retargeting methods. After reviewing literature from researchers it is suggested that the use of the single operator in image retargeting such as scaling, cropping, seam carving, and warping is not sufficient for obtaining satisfactory results, hence it is essential to combine multiple image retargeting operators. This survey is useful for the researchers interested in content-aware image retargeting.

Simple Model on Water Retention and Permeability in Soil Mixed with Lignocellulose Fibres

Ni Junjun,Bordoloi Sanandam,Garg Ankit,Shao Wei,Sreedeep S 대한토목학회 2019 KSCE JOURNAL OF CIVIL ENGINEERING Vol.23 No.1

Natural or lignocellulose fibres have been widely used for reinforcing soils in geotechnical infrastructures by using their mechanical reinforcement. However, less attention has been taken to the hydraulic properties of soil-lignocellulose fibre composites, namely Soil Water Retention Curve (SWRC) and soil water permeability. These hydraulic properties are the key parameters when conducting transient seepage analysis in reinforced slope stability calculation. Till now, there is no model yet that can capture SWRC and water permeability of soil-lignocellulose fibre composite. This technical note aims to develop a new and simple model for predicting the SWRC and water permeability of soils mixed with lignocellulose fibres. The model considers the void ratio change by incorporating the air void from fibres. The void ratio function is then fed into a void-ratio-dependent SWRC model. SWRCs and water permeability of soils mixed with two lignocellulose fibres (jute and coir) were measured systematically to provide high quality data to validate the proposed model. There were three replicates for each case. It shows that the presence of pore structures in natural fibres reduced air entry value of soils from 8 kPa to 2-3 kPa, while it had no effects on desorption rates. Moreover, those pores in lignocellulose fibres increased the water flow path, resulting in increased water permeability. As demonstrated by dye tracer experiments, the increased water flow was along the cellulose, hemicellulose fibrils inside the fibre and soil-fibre interface. The comparisons between experimental measurements and model predictions indicate that the proposed simple model can capture the effects of natural fibres on soil hydraulic properties quite well, with the maximum discrepancy less than 15% and 28% for SWRC and water permeability, respectively.

Experimental study on water exchange between crack and clay matrix

Song, Lei,Li, Jinhui,Garg, Ankit,Mei, Guoxiong Techno-Press 2018 Geomechanics & engineering Vol.14 No.3

Cracks in soil provide significant preferential pathways for contaminant transport and rainfall infiltration. Water exchange between the soil matrix and crack is crucial to characterize the preferential flow, which is often quantitatively described by a water exchange ratio. The water exchange ratio is defined as the amount of water flowing from the crack into the clay matrix per unit time. Most of the previous studies on the water exchange ratio mainly focused on cracked sandy soils. The water exchange between cracks and clay matrix were rarely studied mainly due to two reasons: (1) Cracks open upon drying and close upon wetting. The deformable cracks lead to a dynamic change in the water exchange ratio. (2) The aperture of desiccation crack in clay is narrow (generally 0.5 mm to 5 mm) which is difficult to model in experiments. This study will investigate the water exchange between a deformable crack and the clay matrix using a newly developed experimental apparatus. An artificial crack with small aperture was first fabricated in clay without disturbing the clay matrix. Water content sensors and suction sensors were instrumented at different places of the cracked clay to monitor the water content and suction changes. Results showed that the water exchange ratio was relatively large at the initial stage and decreased with the increasing water content in clay matrix. The water exchange ratio increased with increasing crack apertures and approached the largest value when the clay was compacted at the water content to the optimal water content. The effective hydraulic conductivity of the crack-clay matrix interface was about one order of magnitude larger than that of saturated soil matrix.

Influence of Soil Type on Single and Competitive Retention Behavior of Inorganic Macro Cations in Binary as well as Ternary Solution

Poly Buragohain,Peng Lin,Ankit Garg,Sreedeep S,David Hui 대한토목학회 2019 KSCE JOURNAL OF CIVIL ENGINEERING Vol.23 No.12

Inorganic macro cations (Na+, K+ and Ca+) co-exist in agricultural and municipal landfill sites. The retention behavior of these ions in different soils and combinations (binary and ternary system) has not been fully understood by previous studies. This study seeks to probe into the retention behavior of macro cations (Na+, K+, Ca+2) in six different soils under multiple combinations of ions solution. The retention of common ions was quantified by using Freundlich and Langmuir isotherms. Na+ (single) pollutant-soil interaction was desorbed in most of the soils. The retention of K+ and Ca+2 was much greater than that of Na+. There is no definite trend for retention of Na+ in the presence of K+. For all soils, the retention results of K+ in the presence of Na+ decreased. Affinity for K+ was greater than that for Ca+2 in most of the soils. This study also demonstrated the affinity sequence of the ion retention for each soil and the percentage reduction of ions in competition with respect to single ions. Anomalous trends of the isotherm parameter fitting suggested the limitation of the mathematical models in predicting the experimental data. These results can be helpful in improving accuracy of fate prediction of pollutant fate and thus, design of waste containment facilities for various wastes that contains inorganic ions.

Combination coefficient of ESWLs of a high-rise building with an elliptical cross-section

Qinhua Wang,Shuzhi Yu,Chiujen Ku,Ankit Garg 한국풍공학회 2020 Wind and Structures, An International Journal (WAS Vol.31 No.6

As the height and flexibility of high-rise buildings increase, the wind loads become more dominant and the combination coefficient of Equivalent Static Wind Loads (ESWLs) should be considered when they are used in the structural design. In the first phase of the study, a brief introduction to the theory on the combination coefficient for high-rise buildings was given and then the time history of wind-induced responses of a 208-meter high-rise building with an elliptical cross-section was presented based on the wind tunnel test results for pressure measurement. The correlation between wind-induced responses was analyzed and the combination coefficients of ESWLs of the high-rise buildings using Turkstra’s rule, and Asami’s method, were calculated and compared with related design codes, e.g., AIJ-RLB, ASCE 7-10, and China Load Code for structural design. The results of the study showed that the combination coefficients from Asami’s method are conservative compared with the other three methods. The results of this paper would be helpful to the wind-resistant design of high-rise buildings with elliptical cross-section.

Long-term health monitoring for deteriorated bridge structures based on Copula theory

Zhang, Yi,Kim, Chul-Woo,Tee, Kong Fah,Garg, Akhil,Garg, Ankit Techno-Press 2018 Smart Structures and Systems, An International Jou Vol.21 No.2

Maintenance of deteriorated bridge structures has always been one of the challenging issues in developing countries as it is directly related to daily life of people including trade and economy. An effective maintenance strategy is highly dependent on timely inspections on the bridge health condition. This study is intended to investigate an approach for detecting bridge damage for the long-term health monitoring by use of copula theory. Long-term measured data for the seven-span plate-Gerber bridge is investigated. Autoregressive time series models constructed for the observed accelerations taken from the bridge are utilized for the computation of damage indicator for the bridge. The copula model is used to analyze the statistical changes associated with the modal parameters. The changes in the modal parameters with the time are identified by the copula statistical properties. Applicability of the proposed method is also discussed based on a comparison study among other approaches.

Assessment of flexural and splitting strength of steel fiber reinforced concrete using automated neural network search

Zhang, Zhenhao,Paul, Suvash C.,Panda, Biranchi,Huang, Yuhao,Garg, Ankit,Zhang, Yi,Garg, Akhil,Zhang, Wengang Techno-Press 2020 Advances in concrete construction Vol.10 No.1

Flexural and splitting strength behavior of conventional concrete can significantly be improved by incorporating the fibers in it. A significant number of research studies have been conducted on various types of fibers and their influence on the tensile capacity of concrete. However, as an important property, tensile capacity of fiber reinforced concrete (FRC) is not modelled properly. Therefore, this paper intends to formulate a model based on experiments that show the relationship between the fiber properties such as the aspect ratio (length/diameter), fiber content, compressive strength, flexural strength and splitting strength of FRC. For the purpose of modeling, various FRC mixes only with steel fiber are adopted from the existing research papers. Automated neural network search (ANS) is then developed and used to investigate the effect of input parameters such as fiber content, aspect ratio and compressive strength to the output parameters of flexural and splitting strength of FRC. It is found that the ANS model can be used to predict the flexural and splitting strength of FRC in a sensible precision.

Long-term health monitoring for deteriorated bridge structures based on Copula theory

Yi Zhang,Chul-Woo Kim,Kong Fah Tee,Akhil Garg,Ankit Garg 국제구조공학회 2018 Smart Structures and Systems, An International Jou Vol.21 No.2

Maintenance of deteriorated bridge structures has always been one of the challenging issues in developing countries as it is directly related to daily life of people including trade and economy. An effective maintenance strategy is highly dependent on timely inspections on the bridge health condition. This study is intended to investigate an approach for detecting bridge damage for the long-term health monitoring by use of copula theory. Long-term measured data for the seven-span plate-Gerber bridge is investigated. Autoregressive time series models constructed for the observed accelerations taken from the bridge are utilized for the computation of damage indicator for the bridge. The copula model is used to analyze the statistical changes associated with the modal parameters. The changes in the modal parameters with the time are identified by the copula statistical properties. Applicability of the proposed method is also discussed based on a comparison study among other approaches.