A Parallel Architecture for Constructing the Minimal Spanning Tree in the Euclidean Space

Sabyasachy Choudhury,M. Narasimha Murty 대한전자공학회 1997 TENCON 87 - Computers and Communications Technolog Vol.- No.-

Preparation and characterization of ibuprofen-loaded alginate microspheresusing ethylenediamine as a crosslinker

Sabyasachi Maiti,Biswanath Sa 경희대학교 융합한의과학연구소 2008 Oriental Pharmacy and Experimental Medicine Vol.8 No.2

In this study, ionotropic gelation method was used for the preparation of ibuprofen-loaded calcium alginate (CALG) and ethylenediamine (EDA) treated calcium alginate (EDA-CALG) microspheres. The effect of EDA-treatment on drug entrapment efficiency, particle size, morphology, swelling behavior and in vitro release characteristics of the microspheres was investigated by varying its concentration from 0.5 to 2% (v/v). The reduction in drug entrapment efficiency by a maximum of 44.60% was noted for EDA-CALG microspheres compared to untreated CALG microspheres. The particle size and swelling index of EDA-CALG microspheres were reduced with increasing EDA concentration. All the microspheres were observed to retain their spherical shapes with rough surfaces. EDA-CALG microspheres prepared using 1% and 2% v/v EDA, released almost all of its content within 7 h in pH 6.8 phosphate buffer, however, CALG microspheres were found to release the same within 3 h. The intensity of melting endothermic peak of ibuprofen reduced significantly at lower drug load as experienced from DSC thermograms. The FT-IR spectrum of pure ibuprofen, ibuprofen-loaded CALG and EDA-CALG microspheres showed the characteristic band of C = O stretching vibration of ibuprofen. Hence, this study revealed that EDA can be employed for the preparation of ibuprofen-loaded CALG microspheres to retard the drug release to some extent. In this study, ionotropic gelation method was used for the preparation of ibuprofen-loaded calcium alginate (CALG) and ethylenediamine (EDA) treated calcium alginate (EDA-CALG) microspheres. The effect of EDA-treatment on drug entrapment efficiency, particle size, morphology, swelling behavior and in vitro release characteristics of the microspheres was investigated by varying its concentration from 0.5 to 2% (v/v). The reduction in drug entrapment efficiency by a maximum of 44.60% was noted for EDA-CALG microspheres compared to untreated CALG microspheres. The particle size and swelling index of EDA-CALG microspheres were reduced with increasing EDA concentration. All the microspheres were observed to retain their spherical shapes with rough surfaces. EDA-CALG microspheres prepared using 1% and 2% v/v EDA, released almost all of its content within 7 h in pH 6.8 phosphate buffer, however, CALG microspheres were found to release the same within 3 h. The intensity of melting endothermic peak of ibuprofen reduced significantly at lower drug load as experienced from DSC thermograms. The FT-IR spectrum of pure ibuprofen, ibuprofen-loaded CALG and EDA-CALG microspheres showed the characteristic band of C = O stretching vibration of ibuprofen. Hence, this study revealed that EDA can be employed for the preparation of ibuprofen-loaded CALG microspheres to retard the drug release to some extent.

Damage assessment of frame structure using quadratic time-frequency distributions

Sabyasachi Chandra,S.V. Barai 국제구조공학회 2014 Structural Engineering and Mechanics, An Int'l Jou Vol.49 No.3

This paper presents the processing of nonlinear features associated with a damage event by quadratic time-frequency distributions for damage identification in a frame structure. A time-frequency distribution is a function which distributes the total energy of a signal at a particular time and frequency point. As the occurrence of damage often gives rise to non-stationary, nonlinear structural behavior, simultaneous representation of the dynamic response in the time-frequency plane offers valuable insight fordamage detection. The applicability of the bilinear time-frequency distributions of the Cohen class is examined for the damage assessment of a frame structure from the simulated acceleration data. It is shown that the changes in instantaneous energy of the dynamic response could be a good damage indicator. Presence and location of damage can be identified using Choi-Williams distribution when damping is ignored. However, in the presence of damping the Page distribution is more effective and offers better readability for structural damage detection.

Carbon Nanostructures Based Mechanically Robust Conducting Cotton Fabric for Improved Electromagnetic Interference Shielding

Sabyasachi Ghosh,Subhadip Mondal,Sayan Ganguly,Sanjay Remanan,Nikhil Singha,Narayan Ch. Das 한국섬유공학회 2018 Fibers and polymers Vol.19 No.5

Herein, an intelligent cotton fabric was fabricated using a non-ionic surfactant based macro structured carbonaceous coating through the ‘knife-over-roll’ technique. The developed novel fabric was tested as flexible, mechanically robust with prolonged chemical/moisture resistance. Various characterization techniques were thoroughly used to analyze the fabric. The as-prepared fabric shows an outstanding electromagnetic interference (EMI) shielding efficiency (SE) of about 21.5 dB even at the lowest possible coating thickness (0.20 mm) where the highest EMI SE of 30.8 dB is obtained at only 0.30 mm coating thickness over the X-band frequency range (8.2-12.4 GHz), possibly due to the threedimensionally interconnected network structure of conducting carbon particles. The micro-computed tomography disclosed the porous architecture and “void-filler” arrangement within the fabrics. For the betterment of serviceability and practicability of the coated fabric, the water tolerance and contact angle studies were conducted. The relatively high contact angle than pure cotton fabric, and excellent water resistance after coating ensure improved endurance for external or industrial uses. Therefore, this proof-of-construct manifests commercialization of the developed fabric for multipurpose applications in a facile, less-hazardous and economical way.

Modeling of the Drivers’ Decision-Making Behavior During Yellow Phase

Sabyasachi Biswas,Indrajit Ghosh 대한토목학회 2018 KSCE JOURNAL OF CIVIL ENGINEERING Vol.22 No.11

Stop and go modeling at signalized intersections under heterogeneous traffic conditions has remained one of the most sought-after fields. Drivers are often caught up in the dilemma zone and unable to take quick decisions whether to stop or cross the intersection. This hampers the traffic movement and may lead to accidents. These variables include distance-to-stop line, time-to-stop line, approach speed, acceleration/deceleration and category of the vehicle. Further, using external validation, the overall accuracy levels of the drivers' decision models based on Logistic regression (81.5 percent), Fuzzy Logic (86.98 percent) and ANN (88.67 percent) were compared. Further, a hybrid surrogate model, incorporating the ‘Weighted Average’ technique was developed so that the individual disparities were diminished and the overall accuracy for both stopping and crossing vehicles was improved. This Weighted Average Hybrid Model (WAHM), formulated by coupling Fuzzy Logic and ANN, yielded a highly accurate result (96.15 percent) and outperformed both ANN and Fuzzy Logic.

Detection of Parkinson’s Disease using 3D Convolutional Neural Networks

Sabyasachi Chakraborty,김범수,김희철 한국정보통신학회 2020 한국정보통신학회 종합학술대회 논문집 Vol.24 No.1

Detection of Pneumonia from Chest X-Rays using a Convolutional Neural Network Architecture.

Sabyasachi Chakraborty,Satyabrata Aich,Jong Seong Sim,Hee-Cheol Kim 한국정보통신학회 2019 2016 INTERNATIONAL CONFERENCE Vol.11 No.1

Seamless and efficient diagnosis of pneumonia in children and adults is predominantly very important for the physicians. As pneumonia is a disease which kills around 50000 people each year globally therefore adequate treatment and adequate cure of the particular disease must be made essential for the prevention of the unnecessary deaths. Conventionally for the detection and diagnosis of pneumonia physicians often use X-rays of chest to promptly and economically diagnose the disease The architecture of convolutional neural network devised in the work performs a thorough analysis on the chest x-rays by identifying the spatial placement of the activations that led to the detection of pneumonia in a chest x-ray. The model developed in the work posed an accuracy of 95.62% with an average precision and recall of 96% and 95% respectively.

Fabrication of Reduced Graphene Oxide/Silver Nanoparticles Decorated Conductive Cotton Fabric for High Performing Electromagnetic Interference Shielding and Antibacterial Application

Sabyasachi Ghosh,Sayan Ganguly,Poushali Das,Tushar Kanti Das,Madhuparna Bose,Nikhil K. Singha,Amit Kumar Das,Narayan Ch. Das 한국섬유공학회 2019 Fibers and polymers Vol.20 No.6

Conductive filler loading in the polymer matrix is a common practice to transform insulative polymers toconducting composites. In case of textiles, the highly promising approach has been coined by virtue of fabricating withconductive adhesive homogeneous coating. The present fabrication approach has been developed by two-stage wet mixingtechnique including synthesis of silver nanoparticles decorated graphene sheets (rGO/Ag), followed by the preparation ofconducting coating by non-ionic polymer adhesive. The novelty lies in the choice of conductive material and coating strategyto make lightweight and flexible smart electronic fabric. In order to protect the radiation pollution from the immense use ofelectronic devices and gadgets, the coated textiles can be an excellent replacement of other commercially available polymercoatings. The electromagnetic interference (EMI) shielding effectiveness of the prepared coated textile was 27.36 dB in the Xband (8.2-12.4 GHz). Besides this it is worth mentioning that our developed coated fabric was enough conductive to light upa series of 57 LEDs with high intensity. Last but not the least this work also reconnoitres bactericidal feature against E. coli.

Adult Stem Cells: Beyond Regenerative Tool, More as a Bio-Marker in Obesity and Diabetes

Sabyasachi Sen 대한당뇨병학회 2019 Diabetes and Metabolism Journal Vol.43 No.6

Obesity, diabetes, and cardiovascular diseases are increasing rapidly worldwide and it is therefore important to know the effect of exercise and medications for diabetes and obesity on adult stem cells. Adult stem cells play a major role in remodeling and tissue regeneration. In this review we will focus mainly on two adult stem/progenitor cells such as endothelial progenitor cells and mesenchymal stromal cells in relation to aerobic exercise and diabetes medications, both of which can alter the course of regeneration and tissue remodelling. These two adult precursor and stem cells are easily obtained from peripheral blood or adipose tissue depots, as the case may be and are precursors to endothelium and mesenchymal tissue (fat, bone, muscle, and cartilage). They both are key players in maintenance of cardiovascular and metabolic homeostasis and can act also as useful biomarkers.

The impact of agricultural activities on urbanization: evidence and implications for India

Sabyasachi Tripathi,Chetana Rani 서울시립대학교 도시과학연구원 2018 도시과학국제저널 Vol.22 No.1

As a part of the development process, India is currently going through a transformation from agriculture based economy to industry and service lead urbanized economy. However, no formal quantitative research has been done on this phenomenon. In this perspective, based on Matsuyama’s (1992. Agricultural productivity, comparative advantage and economic growth. Journal of Economic Theory, 58(2), 317–334. doi:10.1016/0022-0531(92)90057-O) theoretical framework and using panel data model, the impact of agricultural activities on urbanization in India is analyzed in this paper. For the analysis 15 major agricultural states of India are considered for the period of 1981–2015 by sourcing data from mainly Census of India and Ministry of agriculture, government of India. The results indicates that overall agricultural activities measured by share, growth rate and total agricultural production, amount of cultivated land area, amount of rainfall and rural male employment have a negative effect on urbanization. However, some specific agricultural activities such as higher consumption of fertilizer, state government expenditure on agriculture, production of major crops (wheat, bajra and pulses), rural female employment in agriculture, and rural literacy rate have had a positive impact on urbanization. The results also show that the effect of agriculture productivity is positive on urbanization for a less trade open economy like India. Finally, it is suggested that there is need of higher agricultural development in order to achieve a higher level of urbanization in India. For this purpose use of technology in agriculture sector along with higher level rural education is required. Finally, we need to have balanced rural and urban policy for a smooth rural- urban transformation in India.