Multi-type, multi-sensor placement optimization for structural health monitoring of long span bridges

Soman, Rohan N.,Onoufrioua, Toula,Kyriakidesb, Marios A.,Votsisc, Renos A.,Chrysostomou, Christis Z. Techno-Press 2014 Smart Structures and Systems, An International Jou Vol.14 No.1

The paper presents a multi-objective optimization strategy for a multi-type sensor placement for Structural Health Monitoring (SHM) of long span bridges. The problem is formulated for simultaneous placement of strain sensors and accelerometers (heterogeneous network) based on application demands for SHM system. Modal Identification (MI) and Accurate Mode Shape Expansion (AMSE) were chosen as the application demands for SHM. The optimization problem is solved through the use of integer Genetic Algorithm (GA) to maximize a common metric to ensure adequate MI and AMSE. The performance of the joint optimization problem solved by GA is compared with other established methods for homogenous sensor placement. The results indicate that the use of a multi-type sensor system can improve the quality of SHM. It has also been demonstrated that use of GA improves the overall quality of the sensor placement compared to other methods for optimization of sensor placement.

Realtime 환경 내 Serial 통신장비 연동방안 연구

손소만(Soman Son),홍인표(Inpyo Hong) 한국항공우주학회 2020 한국항공우주학회 학술발표회 논문집 Vol.2020 No.11

Multi-type, multi-sensor placement optimization for structural health monitoring of long span bridges

Rohan N. Soman,Toula Onoufriou,Marios A. Kyriakides,Renos A. Votsis,Christis Z. Chrysostomou 국제구조공학회 2014 Smart Structures and Systems, An International Jou Vol.14 No.1

The paper presents a multi-objective optimization strategy for a multi-type sensor placement for Structural Health Monitoring (SHM) of long span bridges. The problem is formulated for simultaneous placement of strain sensors and accelerometers (heterogeneous network) based on application demands for SHM system. Modal Identification (MI) and Accurate Mode Shape Expansion (AMSE) were chosen as the application demands for SHM. The optimization problem is solved through the use of integer Genetic Algorithm (GA) to maximize a common metric to ensure adequate MI and AMSE. The performance of the joint optimization problem solved by GA is compared with other established methods for homogenous sensor placement. The results indicate that the use of a multi-type sensor system can improve the quality of SHM. It has also been demonstrated that use of GA improves the overall quality of the sensor placement compared to other methods for optimization of sensor placement.

Qualitative Grading as a Tool in the Management of Multilevel Lumbar Spine Stenosis

Shardul Madhav Soman,Jimmy Chokshi,Naitik Chhatrala,Gulam Haider Tharadara,Mukund Prabhakar 대한척추외과학회 2017 Asian Spine Journal Vol.11 No.2

Study Design: This is a prospective study that was undertaken at a single centre and involved 80 consecutive patients diagnosed with lumbar spinal stenosis (LSS). Purpose: The aim of the study was to assess the efficacy of a qualitative grading system as seen on magnetic resonance imaging (MRI) as a tool in the management of multilevel LSS. Overview of Literature: LSS diagnosis is clinical but is usually radiologically supplemented. However, there are often multilevel radiological findings with non-specific or atypical clinical features. We used a qualitative grading system to help in the decision-making process of the management of patients with multilevel LSS. Methods: 80 patients with LSS were treated with decompression and prospectively followed-up for a minimum of 12 months. All had failed conservative treatment. Qualitative grading of LSS severity was based on the dural sac in T2 weighted axial MRI images at all disc levels and was done from L1–2 to L5–S1 (n=400). Functional outcome was assessed using the Oswestry disability index (ODI). Results: The mean patient age was 56.6 years, with a gender ratio of 0.6:1. Forty patients had degenerative LSS and 40 had degenerative spondylolysthesis. A total of 178 levels were decompressed, the majority of which were L4–L5 (43.82%), followed by L5–S1 (41.57%). According to our qualitative grading system, grade D stenosis (53.93%) was decompressed most frequently, followed by grade C stenosis (41.57%). The average preoperative ODI score was 58.55%, which later reduced to 19.15%. Seventy percent of patients achieved excellent results, whereas 30% achieved good results. Conclusions: Morphological grading is a useful tool in decision making in surgery for multilevel LSS. Grade C and D stenosis should be decompressed, whereas A and B should not be, unless clinically justified.

Siamese neural network architecture for homoglyph attacks detection

Vinayakumar R.,Soman K.P. 한국통신학회 2020 ICT Express Vol.6 No.1

Primarily an adversary uses homoglyph or spoofing attack approach to obfuscate domain name, file name or process names. This approach facilitates to create domain name, file name or process names which look visually homogeneous to legitimate domain name, file name or process names. This paper introduces Siamese neural network architecture which uses the application of recurrent structures with Keras character level embedding to learn the optimal features by considering an input in the form of raw strings. For comparative study, various recurrent structures are used. The performances obtained by recurrent structures are almost closer. However, the proposed method performed well in comparison to the existing methods such as Edit Distance, Visual Edit Distance and Siamese convolutional neural networks.

Structural Reinforcement of Cell-Laden Hydrogels with Microfabricated Three Dimensional Scaffolds.

Cha, Chaenyung,Soman, Pranav,Zhu, Wei,Nikkhah, Mehdi,Camci-Unal, Gulden,Chen, Shaochen,Khademhosseini, Ali Royal Society of Chemistry 2014 Biomaterials Science Vol.2 No.5

<P>Hydrogels commonly used in tissue engineering are mechanically soft, thus often display structural weakness. Herein, we introduce a strategy for enhancing the structural integrity and fracture toughness of cell-laden hydrogels by incorporating a three-dimensional (3D) microfabricated scaffold as a structural element. A digital micromirror device projection printing (DMD-PP) system, a rapid prototyping technology which employs a layer-by-layer stereolithographic approach, was utilized to efficiently fabricate 3D scaffolds made from photocrosslinkable poly(ethylene glycol) diacrylate (PEGDA). The scaffold was incorporated into a photocrosslinkable gelatin hydrogel by placing it in a pre-gel solution, and inducing in situ hydrogel formation. The resulting scaffold-reinforced hydrogels demonstrated significant increase in ultimate stress and provided structural support for weak hydrogels. In addition, the scaffold did not affect the rigidity of hydrogels, as it was not involved in the crosslinking reaction to form the hydrogel. Therefore, the presented approach could avoid inadvertent and undesired changes in the hydrogel rigidity which is a known regulator of cellular activities. Furthermore, the biocompatibility of scaffold-reinforced hydrogels was confirmed by evaluating the viability and proliferation of encapsulated fibroblasts. Overall, the strategy of incorporating 3D scaffolds into hydrogels as structural reinforcements presented in this study will be highly useful for enhancing the mechanical toughness of hydrogels for various tissue engineering applications.</P>

DeepMalNet: Evaluating Shallow and Deep networks for Static PE Malware Detection

Vinayakumar R.,Soman K.P. 한국통신학회 2018 ICT Express Vol.4 No.4

This paper primarily evaluates the efficacy of shallow and deep networks to statically detect malicious windows portable executable (PE) files. This uses recently released, labeled and benchmark data set, EMBER malware benchmark data set. As deep networks are parameterized, the parameters are chosen based on comparing the performance of various network parameters and network topologies over various trials of experiments. The experiments of such chosen efficient configurations of deep models are run up to 1000 epochs with varying learning rates between 0.01 and 0.5. The observed results of deep networks are high compared to the shallow networks.

Using Minute Papers to Improve Lecture Demonstrations

Hurh, Eunyoung,Soman, Sherril A.,Robinson, William R. 한국과학교육학회 2005 한국과학교육학회지 Vol.25 No.1

Minute papers are brief papers written at the end of a lecture in response to one or two questions posed by the instructor. The answers are discussed briefly at the beginning of the next lecture. We used minute papers to follow students' understanding and response to lecture demonstrations in an introductory general chemistry course. An analysis of these minute papers suggest that the following characteristics are important, when using demonstrations as teaching aids. 1) The purpose of a demonstration should be stated as explicitly as possible. 2) Instructors should be explicit about what is happening and what students should be looking for .3) Demonstrations should be kept as simple as possible, perhaps illustrating one concept. Finally, we note that students believe that the visual component of demonstrations enhances their comprehension of chemistry concepts.

Differential Mast Cell Response to Different Bacteria

Jugmin Kim,Soman N. Abraham 대한미생물학회 2004 Journal of Bacteriology and Virology Vol.34 No.4

Spatiotemporal analysis of environmental and physiographic factors related to malaria in Bareilly district, India

Shikhar Chaudhary,Biju Soman 질병관리본부 2022 Osong Public Health and Research Persptectives Vol.13 No.2

Objectives: The aim of this study was to explore the spatiotemporal clustering of reported malaria cases and to study the effects of various environmental and physiographic factors on malaria incidence in Bareilly district, Uttar Pradesh, India. Methods: Malaria surveillance data were collected from the state health department and cleaned into an analyzable format. These data were analyzed along with meteorological, physiographic, and 2019 population data, which were obtained from the Indian Meteorological Department, National Aeronautics and Space Administration web portal, the Bhuvan platform of the Indian Space Research Organization, and the 2011 Census of India. Results: In total, 46,717 malaria cases were reported in Bareilly district in 2019, of which 25.99% were Plasmodium vivax cases and 74.01% were P. falciparum cases. The reported malaria cases in the district showed clustering, with significant spatial autocorrelation (Moran’s I value=0.63), and space-time clustering (p<0.01). A significant positive correlation was found between monthly malaria incidence and the monthly mean temperature (with a lag of 1−2 months) and rainfall (with a lag of 1 month). A significant negative correlation was detected between the elevation of blocks (i.e., intermediate-level administrative districts) and annual malaria reporting. Conclusion: The presence of space-time clustering of malaria cases and its correlation with meteorological and physiographic factors indicate that routine spatial analysis of the surveillance data could help control and manage malaria outbreaks in the district.