Solving Target Coverage Problem in Wireless Sensor Network Using Genetic Algorithm

The past few years have seen tremendous increase of interest in the field of wireless sensor network. These wireless sensor network comprise numerous small sensor nodes distributed in an area and collect specific data from that area. The nodes comprising a network are mostly battery driven and hence have a limited amount of energy. The target coverage deals with the surveillance of the area under consideration taking into account the energy constraint associated with nodes. In nutshell, the lifetime of the network is to be maximized while ensuring that all the targets are monitored. The approach of segregating the nodes into various covers is used such that each cover can monitor all the targets while other nodes in remaining covers are in sleep state. The covers are scheduled to operate in turn thereby ensuring that the targets are monitored all the time and the lifetime of the network is also maximized. The segregation method is based on Maximum Set Cover (MSC) problem which is transformed into Maximum Disjoint Set Cover problem (MDSC). This problem of finding Maximum Disjoint Set Cover falls under the category of NP-Complete problem. Hence, two heuristics based approach are discussed in this work; first Greedy Heuristic is implemented to be used as baseline. Then a Genetic Algorithm based approach is proposed that can solve this problem by evolutionary global search technique. The existing and proposed algorithms are coded and functionality verified using MATLAB R2010b and performance evaluation and comparisons are made in terms of number of sensors and sensing range

Giant-cell tumour of proximal radius in a 50-year-old female with wrist drop: a rare case report

Abstract Giant-cell tumour is a locally aggressive tumour of long bones of epiphyseal region commonly occurring in adults aged 20–40 years. Most common location is distal femur, proximal tibia, and distal radius. Different treatment options being used are curettage with bone graft or bone cement, resection with arthrodesis, reconstruction, radiation, and chemotherapy. We are reporting a case of giant-cell tumour of right proximal radius in a 50-year-old female with posterior interosseous nerve palsy. It is very rare, and only four cases have been reported in the literature. It was treated by wide margin resection with fibular grafting, titanium elastic nail system along with cancellous bone graft reconstruction

NUMERICAL AND EXPERIMENTAL INVESTIGATION OF WALL SHEAR STRESS GENERATED BY A BERNOULLI PAD

Thesis (Ph.D.)--Michigan State University. Mechanical Engineering - Doctor of Philosophy, 2024Bernoulli pads can create a significant normal force on an object without contact, which allows them to be traditionally used for non-contact pick-and-place operations in industry. In addition to the normal force, the pad produces shear forces, which can be utilized in cleaning a workpiece without contact. The motivation for the present work has been to understand the flow physics of the Bernoulli pad such that they can be employed for non-contact biofouling mitigation of ship hulls. Numerical investigations have shown that the shear stress distribution generated by the action of the Bernoulli pad on the workpiece is concentrated and results in maximum shear stress very close to the neck of the pad. The maximum value of wall shear stress is an important metric for determining the cleaning efficacy of the Bernoulli pad. We use numerical simulations over a range of parameter space to develop a relationship between the inlet fluid power and the maximum shear stress obtained on the workpiece. To increase the shear force distribution, we explore the possibility of adding mechanical power to the system in addition to the fluid power. The flow field between the Bernoulli pad and the workpiece typically involves a recirculation region and transition between laminar and turbulent flow. The maximum shear stress occurs in the vicinity of the recirculation region and to gain confidence in the numerical solver's ability to estimate these stresses accurately, experiments were conducted with a hot-film sensor.The main contributions of this work are as follows: a direct relationship is obtained between the maximum shear stress on the workpiece and inlet fluid power using dimensional analysis. A relationship between the maximum shear stress and the inlet Reynolds number is also obtained, and implications of these scaling relationships are studied. A direct relationship between the inlet fluid power and the shear losses motivates us to explore other methods of providing power to the system with the objective of increasing shear forces and thereby improving cleaning efficacy. We numerically investigate a Bernoulli pad in which additional mechanical power is added by rotating the pad. This additional power increases both the normal and shear forces on the workpiece for the same inlet fluid power. In the context of the rotating Bernoulli pad, it is found that for a given normal attractive force, a stable equilibrium configuration can exist for two different mass flow rates, with the higher mass flow rate resulting in a higher stiffness of the flow field. This phenomenon has not been reported in the literature. The wall shear stress distribution, obtained using numerical simulations, is validated using experiments for the first time. A constant temperature anemometer is used with a hot-film sensor and water as the working fluid; the sensor is calibrated using a fully developed channel flow. An experimental setup is designed to calibrate and later measure the wall shear stress in a Bernoulli pad assembly. The maximum wall shear stress is observed very close to the neck of the pad due to flow constriction and separation; the hot-film experiments accurately capture the magnitude of the maximum shear stress and its location. This provides us with confidence in the numerical solver, which can be used to optimize the Bernoulli pad design to improve its cleaning efficacy.Description based on online resource. Title from PDF t.p. (Michigan State University Fedora Repository, viewed ).Includes bibliographical references

Laser In-Situ Combinatorial Carbide Coating on Steel

The potential for synthesizing an in-situ grown ultra-fine carbide composite coating on the surface of steel during laser surface engineering was investigated. A 2.5 KW Nd:YAG laser was employed to modify the surface of a AISI 1010 steel deposited with a precursor powder mixture of Fe, Ti, Cr and C. With the help of laser surface engineering, carbide composite coating on the surface of plain C steel was achieved. It is envisioned that such a coating will offer superior tribological properties. Energy Dispersive Spectroscopy in supplement with X-ray Diffractometery indicated the evolution of TiC, Fe-Cr, and M7C3 as major phases in the coating. An oscillatory pattern for evolution of M7C3 was observed with respect to the laser power over the range of 900-2100 watts during processing. Although TiC was present in all the samples, the chromium carbides were absent in samples processed at certain laser powers. Corresponding to this behavior, variation in mechanical properties of the coating was observed. The hardness and wear properties of the samples without chromium carbides was inferior in comparison to samples with both TiC and chromium carbides. The roles of in-situ growth, refractory nature of the carbide particles, the non-equilibrium nature of the process and their contribution in successfully forming a composite coating have been described. Computational techniques were employed with the aim of studying possible reasons for phase evolution, stability of phases and solidification path and thus optimize parameters to tailor properties according to requirement. The temperature range of thermal transitions within the quaternary system (Fe, Ti, Cr and C) and the thermal stability of the evolved phases were studied with the help of differential scanning calorimetry (DSC). DSC studies indicated that the major exothermic reactions (formation of carbides) take place within 850-1150oC. Temperature ranges for individual reactions were investigated. The evolved phases (TiC, M7C3, Fe-Cr and Fe3C) were characterized using X-ray diffraction (XRD). This multicomponent powder mixture, which was used as a precursor for synthesizing a composite coating on the surface of steel via laser surface engineering (LSE), was computationally investigated for thermal stability. The intended wear applications of the coating made thermal stability investigations imperative, as there is a localized heat buildup during wear, because of the contact between rubbing surfaces. Experimental evaluation (DSC) of thermal stability of the phases formed was done to supplement the computational investigations. The degradation of the coating due to prolonged stay at elevated temperatures (in oxidizing environments such as air) could lead to degradation in the properties of the coating. High temperature oxidation studies were done to investigate the oxidation kinetics of the composite coating

PublishInCovid19 at WNUT 2020 Shared Task-1: Entity Recognition in Wet Lab Protocols using Structured Learning Ensemble and Contextualised Embeddings

In this paper, we describe the approach that we employed to address the task of Entity Recognition over Wet Lab Protocols -- a shared task in EMNLP WNUT-2020 Workshop. Our approach is composed of two phases. In the first phase, we experiment with various contextualised word embeddings (like Flair, BERT-based) and a BiLSTM-CRF model to arrive at the best-performing architecture. In the second phase, we create an ensemble composed of eleven BiLSTM-CRF models. The individual models are trained on random train-validation splits of the complete dataset. Here, we also experiment with different output merging schemes, including Majority Voting and Structured Learning Ensembling (SLE). Our final submission achieved a micro F1-score of 0.8175 and 0.7757 for the partial and exact match of the entity spans, respectively. We were ranked first and second, in terms of partial and exact match, respectively

Biasing & Debiasing based Approach Towards Fair Knowledge Transfer for Equitable Skin Analysis

Deep learning models, particularly Convolutional Neural Networks (CNNs), have demonstrated exceptional performance in diagnosing skin diseases, often outperforming dermatologists. However, they have also unveiled biases linked to specific demographic traits, notably concerning diverse skin tones or gender, prompting concerns regarding fairness and limiting their widespread deployment. Researchers are actively working to ensure fairness in AI-based solutions, but existing methods incur an accuracy loss when striving for fairness. To solve this issue, we propose a `two-biased teachers' (i.e., biased on different sensitive attributes) based approach to transfer fair knowledge into the student network. Our approach mitigates biases present in the student network without harming its predictive accuracy. In fact, in most cases, our approach improves the accuracy of the baseline model. To achieve this goal, we developed a weighted loss function comprising biasing and debiasing loss terms. We surpassed available state-of-the-art approaches to attain fairness and also improved the accuracy at the same time. The proposed approach has been evaluated and validated on two dermatology datasets using standard accuracy and fairness evaluation measures. We will make source code publicly available to foster reproducibility and future research

Posterior reversible encephalopathy syndrome in dengue: a rare manifestation

Dengue is an important arthropod born disease with its cases spiking every 2-3 years and spectrum of disease ranging from mild febrile illness to severe illness with multiple systemic complications including rare neurological manifestation. We hereby presented a case report of rare presentation of posterior reversible encephalopathy syndrome (PRES) in an eight year old child suffering from dengue

Do the FDI, Economic growth and Trade affect each other for India: An ARDL Approach

This paper examines the dynamic causal relationships between foreign direct investment (FDI), trade and economic growth in India by applying the bounds testing (ARDL) approach to cointegration for the period from 1970 to 2012. The bounds tests suggest that the variables of interest are bound together in the long-run when GDP per capita is the dependent variable. The empirical findings confirm that there is bi-directional Granger causality between FDI and trade, unidirectional Granger causality running from FDI to economic growth and from economic growth to capital investment but there is no Granger causality from economic growth to FDI and capital investment to per capita GDP

Pure cartilaginous choristoma on the ventral surface of tongue: A double rarity

Choristomas are tumor like mass that are aggregates of microscopically normal tissue in an abnormal location. Commonly reported choristomas are of Osseous, Cartilaginous, Glandular and Glial types. The oral cavity is an unusual site of presentation where the most common site is dorsum of the tongue. Ventral aspect is an extremely rare site with only four cases reported till date. We report here a case of a 24-year-old male who presented with a small swelling on the ventral surface of the tongue. The histopathological examination revealed features of a well-circumscribed mass composed of exclusively mature cartilage encased within a dense fibrous connective tissue. The case is presented for its double rarity of site which is a ventral surface of the tongue and the histopathology which revealed a pure form of cartilaginous choristoma

Referrals revisited: a clinical audit

Background: Pregnancy and childbirth are physiological processes; however, severe maternal morbidity can complicate certain pregnancies, deliveries and puerperium. To prevent maternal/ neonatal morbidity and mortality, the high-risk category needs timely identification and intervention and if required, prompt referral to higher centres where HDU/ICU level of care is provided. The present study was a clinical audit of obstetric referrals.Methods: A clinical audit of all obstetrics referrals done at BJRM (secondary level facility) from 1st May to 31st October 2016. The cases were analysed with respect to demographics, indications for referral and barrier to services.Results: Referral rate of our hospital was 6.52%. Mean age of women referred was 24.16 years. The associated risk factors were PIH in 36.17%, anaemia in 34.04%, followed by thrombocytopenia and diabetes in pregnancy. Majority of referrals were done in women during labour 93.94% while only 3.03% referrals during post-partum period. Most common indication was MSL with foetal distress 20.96%, followed by hypertensive disorders in pregnancy 16.93%. Other indications were APH, malpresentation, 2nd stage arrest and cord prolapse. The main barriers to providing services at our institute were unavailability of 24 hours OT services, blood bank and ICU care.Conclusions: Standard referral protocol and well-defined linkages need to be established so as to have better co-ordination between the referral units and tertiary centres