Health monitoring of multistoreyed shear building using parametric state space modeling

Medhi, Manab,Dutta, Anjan,Deb, S.K. Techno-Press 2008 Smart Structures and Systems, An International Jou Vol.4 No.1

The present work utilizes system identification technique for health monitoring of shear building, wherein Parametric State Space modeling has been adopted. The method requires input excitation to the structure and also output acceleration responses of both undamaged and damaged structure obtained from numerically simulated model. Modal parameters like eigen frequencies and eigen vectors have been extracted from the State Space model after introducing appropriate transformation. Least square technique has been utilized for the evaluation of the stiffness matrix after having obtained the modal matrix for the entire structure. Highly accurate values of stiffness of the structure could be evaluated corresponding to both the undamaged as well as damaged state of a structure, while considering noise in the simulated output response analogous to real time scenario. The damaged floor could also be located very conveniently and accurately by this adopted strategy. This method of damage detection can be applied in case of output acceleration responses recorded by sensors from the actual structure. Further, in case of even limited availability of sensors along the height of a multi-storeyed building, the methodology could yield very accurate information related to structural stiffness.

Health monitoring of multistoreyed shear building using parametric state space modeling

Manab Medhi,Anjan Dutta,S. K. Deb 국제구조공학회 2008 Smart Structures and Systems, An International Jou Vol.4 No.1

The present work utilizes system identification technique for health monitoring of shear building, wherein Parametric State Space modeling has been adopted. The method requires input excitation to the structure and also output acceleration responses of both undamaged and damaged structure obtained from numerically simulated model. Modal parameters like eigen frequencies and eigen vectors have been extracted from the State Space model after introducing appropriate transformation. Least square technique has been utilized for the evaluation of the stiffness matrix after having obtained the modal matrix for the entire structure. Highly accurate values of stiffness of the structure could be evaluated corresponding to both the undamaged as well as damaged state of a structure, while considering noise in the simulated output response analogous to real time scenario. The damaged floor could also be located very conveniently and accurately by this adopted strategy. This method of damage detection can be applied in case of output acceleration responses recorded by sensors from the actual structure. Further, in case of even limited availability of sensors along the height of a multi-storeyed building, the methodology could yield very accurate information related to structural stiffness.

Draft for discussion only CORRUPTION AND THE PEOPLE`S RIGHTS: HOW THE THAIS PERCEIVE AND DEAL WITH THEIR PUBLIC-SECTOR CORRUPTION

( By Medhi Krongkaew ) 한국행정학회 2013 한국행정학회 학술발표논문집 Vol.2013 No.-

Dew-based offline computing architecture for healthcare IoT

Kishore Medhi,Nurzaman Ahmed,Md. Iftekhar Hussain 한국통신학회 2022 ICT Express Vol.8 No.3

Due to the resource-constraint nature and lack of lightweight computing solutions for diagnostic devices in healthcare IoT, provisioning time-critical responses is still challenging. In this paper, we propose DC-Health, a Dew Computing enabled IoT healthcare solution for offline and ultra-low latency decisions. The proposed solution connects a large number of healthcare devices and provisions user-specific services even when Internet connectivity is not available. The computation module is placed at the extreme edge rather than the cloud to reduce the complexity and to improve the user-specific services. In addition to the other computing facilities provided by the cloud, fog, and edge, our solution performs with a negligible dependency on the Internet.We develop a prototype of DC-Health, which monitors the heart condition using the ECG sensors with end-mile services, flexibility in terms of user-control, and mobility feature. The experimental implementations show that the proposed architecture minimizes the network response time by at least 92% and 98%, compared to the fog and cloud-based approaches, respectively. Along with this, the proposed technique also reduces the CPU and memory usages, and response time by around 30% compared to the conventional method.

Experimental and computational study on flow over stepped spillway

Bhaskar Jyoti Medhi,Anugrah Singh,Ashish Kumar Thokchom,Sadhan Mahapatra 대한기계학회 2019 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.33 No.5

The flow over a stepped spillway has complex nature, and its characteristics are remarkably different from other kinds of spillways. This study conducts experimental investigations and numerical simulations on the flow behavior (velocity, concentration profile) and macroscopic features (interface position and self-aeration) of water and neutrally buoyant suspension of non-colloidal particles in a stepped spillway with uniform steps. The development of nappe, transition, and skimming flow regimes is experimentally investigated by using a flow visualization technique. The inception point related to air entrainments is identified in the experimental study. The inception point usually moves downstream and increases the length of the non-aerated region with the increase of flow rate. Results of numerical and experimental studies indicate that a vortex is formed in the triangular cavity below the pseudo-bottom line (imaginary line joining two adjacent step edges) in the stepped channel. This vortex rotates in a clockwise direction for a short time period and returns to the main flow to move downward in the channel. The velocity vector map from numerical simulation predicts the maximum velocity in the middle portion of the spillway, that is, near the pseudo-bottom line. A volume of fluid model coupled with a standard k–e turbulence model is used in the CFD simulations to predict the location of the air–water air-suspension interface. The results are compared with experimental measurements. The calculated interface position agrees well with the experimental measurements. The migration and transport of particles are evaluated based on a diffusive flux model of shear induced particle migration. The contour map for velocity and particle concentration shows a remarkable increase in particle concentration near the air-suspension interface.

Toxicological evaluation and life cycle assessment of pyrene biodegradation

Rashmi Rathour,Kristina Medhi,Indu Shekhar Thakur 대한환경공학회 2019 대한환경공학회 학술발표논문집 Vol.2019 No.-

Factors Associated With Neurocognitive Impairment Following Chemoradiotherapy in Patients With High-Grade Glioma: Results of a Prospective Trial

( Prashasti Sharma ),( Partha Pratim Medhi ),( Apurba Kumar Kalita ),( Mouchumee Bhattacharyya ),( Jyotiman Nath ),( Gautam Sarma ),( Yanpothung Yanthan ) 대한뇌종양학회·대한신경종양학회·대한소아뇌종양학회 2023 Brain Tumor Research and Treatment Vol.11 No.3

Background High-grade gliomas (HGG) are highly fatal tumors despite advanced multimodality management. They are also associated with neurocognitive impairment, both due to disease pathology and treatment. We aimed to assess various risk factors responsible for neurocognitive decline in HGG patients undergoing adjuvant chemoradiation. Methods Newly diagnosed HGG patients who underwent maximal safe resection were included. Patients received volumetric modulated arc therapy to a dose of 60 Gy in 30 fractions, along with concurrent temozolomide (TMZ) at a dose of 75 mg/m²/day orally; thereafter adjuvant TMZ (150-200 mg/m² for 5 days), given every 28 days for 6 to 8 cycles. The Mini-Mental State Examination questionnaire was used to measure cognitive impairment of each study patient at various time points. Cox regression model was used for univariate and multivariable analysis of data to establish possible risk factors. Results Fifty-three patients were enrolled and analyzed. At a median follow-up of 15 months, 30 patients (56.6%) developed cognitive impairment, and 23 patients (43.4%) did not. On univariate analysis, HGG with WHO grade 4, glioblastoma and diffuse midline glioma histology, IDH-wild type, recursive partitioning analysis class IV/V, and only biopsy of primary tumor were significantly associated with neurocognitive impairment, but none of them were independent risk factors on multivariable analysis. Planning target volume and dose received by ipsilateral hippocampus were also significantly correlated with cognitive decline in HGG patients. Conclusion Decline in neurocognitive functions in HGG patients is multifactorial and can be attributed to an amalgam of various tumor, patient, and treatment-related factors.

A Methodological Comparison on Spatiotemporal Prediction of Criteria Air Pollutants

Pankaj Singh,Rakesh Chandra Vaishya,Pramod Soni,Hemanta Medhi 한국대기환경학회 2022 Asian Journal of Atmospheric Environment (AJAE) Vol.16 No.1

Air pollution monitoring devices are widely used to quantify at-site air pollution. However, such monitoring sites represent pollution of a limited area, and installing multiple devices for a vast area is costly. This limitation of unavailability of data at non-monitoring sites has necessitated the Spatio-temporal analysis of air pollution and its prediction. Few commonly used methods for Spatio-temporal prediction of pollutants include - ‘Averaging’; ‘Best correlation coefficient method’; ‘Inverse distance weighting method’ and ‘Grid interpolation method.’ Apart from these conventional methods, a new methodology, ‘Weighted average method,’ is proposed and compared for air pollution prediction at non-monitoring sites. The weights in this method are calculated based on both on the distance and directional basis. To compare the proposed method with the existing ones, the air pollution levels of NO2 (Nitrogen dioxide), O3 (Ozone), PM10 (Particulate matter of 10 microns or smaller), PM2.5 (Particulate matter of 2.5 microns or smaller), and SO2 (Sulphur dioxide) were predicted at the non-monitoring site (test stations) by utilizing the available data at monitoring sites in Delhi, India. Preliminary correlation analysis showed that NO2, PM2.5, and SO2 have a directional dependency between different stations. The ‘average’ method performed best with the mode RMSE of 18.85 μg/m3 and R2 value 0.7454 when compared with all the methods. The RMSE value of the new proposed method ‘weighted average method’ was 21.25 μg/m3, resulting in the second-best prediction for the study area. The inverse distance weighting method and the Grid interpolation method were third and fourth, respectively, while the ‘best correlation coefficient’ was the worst with an RMSE value of 41.60 μg/m3. Results also showed that the methods that used dependent stations had performed better when compared to methods that used all station data.

Expression of Epstein Barr Virus Encoded EBNA1 and LMP1 Oncoproteins in Nasopharyngeal Carcinomas from Northeast India

Borthakur, Parikhit,Kataki, Kangkana,Keppen, Chenole,Khamo, V.,Medhi, Subhash,Deka, Manab Asian Pacific Journal of Cancer Prevention 2016 Asian Pacific journal of cancer prevention Vol.17 No.7

Background: Nasopharyngeal carcinoma (NPC), a malignancy arising from the epithelial lining of the nasopharynx, is distinct from others cancers in terms of its epidemiologic features. It is rare in most parts of the world except for a few regions with populations of Mongoloid origin. Objectives: To study the expression pattern of Epstein Barr virus (EBV) encoded oncoproteins EBNA1 and LMP1 in different histological types of NPC and to correlate expression patterns with sex, age and histological types. Materials and Methods: A total of 40 formalin-fixed, paraffin-embedded NPC biopsy samples and tissues from 20 healthy controls were collected to study the expression level of EBNA1 and LMP1 using immunohistochemistry. Results: EBNA1 and LMP1 expression was found in 92.5% and 90% respectively, of the cases and none of the control specimens. The expression patterns of EBNA1 and LMP1 were determined to be statistically significant (p<0.05) when correlated with sex, age and histological distributions. Also immunohistochemistry was found to be a sensitive technique in the detection of EBV. Conclusions: The study reveals that the potent oncoproteins EBNA1 and LMP1 were over expressed in our population cohort. Our findings are to some extent inconsistent with earlier reports as our population showed a higher expression of both EBNA1 and LMP1 compared to other studies.

Polymorphisms in Heat Shock Proteins A1B and A1L (HOM) as Risk Factors for Oesophageal Carcinoma in Northeast India

Saikia, Snigdha,Barooah, Prajjalendra,Bhattacharyya, Mallika,Deka, Manab,Goswami, Bhabadev,Sarma, Manash P,Medhi, Subhash Asian Pacific Journal of Cancer Prevention 2015 Asian Pacific journal of cancer prevention Vol.16 No.18

Background: To investigate polymorphisms in heat shock proteins A1B and A1L (HOM) and associated risk of oesophageal carcinoma in Northeast India. Materials and Methods: The study includes oesophageal cancer (ECA) patients attending general outpatient department (OPD) and endoscopic unit of Gauhati Medical College. Patients were diagnosed based on endoscopic and histopathological findings. Genomic DNA was typed for HSPA1B1267 and HSPA1L2437 SNPs using the polymerase chain reaction with restriction fragment length polymorphisms. Results: A total of 78 cases and 100 age-sex matched healthy controls were included in the study with a male: female ratio of 5:3 and a mean age of $61.4{\pm}8.5years$. Clinico-pathological evaluation showed 84% had squamous cell carcinoma and 16% were adenocarcinoma. Dysphagia grades 4 (43.5%) and 5 (37.1%) were observed by endoscopic and hispathological evaluation. The frequency of genomic variation of A1B from wild type A/A to heterozygous A/G and mutant G/G showed a positive association [chi sq=19.9, p=<0.05] and the allelic frequency also showed a significant correlation [chi sq=10.3, with cases vs. controls, OR=0.32, $p{\leq}0.05$]. The genomic variation of A1L from wild T/T to heterozygous T/C and mutant C/C were found positively associated [chi sq=7.02, p<0.05] with development of ECA. While analyzing the allelic frequency, there was no significant association [chi sq=3.19, OR=0.49, p=0.07]. Among all the risk factors, betel quid [OR=9.79, Chi square=35.0, p<0.05], tobacco [OR=2.95, chi square=10.6, p<0.05], smoking [OR=3.23, chi square=10.1, p<0.05] demonstrated significant differences between consumers vs. non consumers regarding EC development. Alcohol did not show any significant association [OR=1.34, chi square=0.69, p=0.4] independently. Conclusions: It can be concluded that the present study provides marked evidence that polymorphisms of HSP70 A1B and HSP70 A1L genes are associated with the development of ECA in a population in Northeast India, A1B having a stronger influence. Betel quid consumption was found to be a highly significant risk factor, followed by smoking and tobacco chewing. Although alcohol was not a potent risk factor independently, alcohol consumption along with tobacco, smoking and betel nut was found to contribute to development of ECA.