Sistemas de posicionamento baseados em comunicação por luz para ambientes interiores

The demand for highly precise indoor positioning systems (IPSs) is growing rapidly due to its potential in the increasingly popular techniques of the Internet of Things, smart mobile devices, and artificial intelligence. IPS becomes a promising research domain that is getting wide attention due to its benefits in several working scenarios, such as, industries, indoor public locations, and autonomous navigation. Moreover, IPS has a prominent contribution in day-to-day activities in organizations such as health care centers, airports, shopping malls, manufacturing, underground locations, etc., for safe operating environments. In indoor environments, both radio frequency (RF) and optical wireless communication (OWC) based technologies could be adopted for localization. Although the RF-based global positioning system, such as, Global positioning system offers higher penetration rates with reduced accuracy (i.e., in the range of a few meters), it does not work well in indoor environments (and not at all in certain cases such as tunnels, mines, etc.) due to the very weak signal and no direct access to the satellites. On the other hand, the light-based system known as a visible light positioning (VLP) system, as part of the OWC systems, uses the pre-existing light-emitting diodes (LEDs)-based lighting infrastructure, could be used at low cost and high accuracy compared with the RF-based systems. VLP is an emerging technology promising high accuracy, high security, low deployment cost, shorter time response, and low relative complexity when compared with RFbased positioning. However, in indoor VLP systems, there are some concerns such as, multipath reflection, transmitter tilting, transmitter’s position, and orientation uncertainty, human shadowing/blocking, and noise causing the increase in the positioning error, thereby reducing the positioning accuracy of the system. Therefore, it is imperative to capture the characteristics of different VLP channel and properly model them for the dual purpose of illumination and localization. In this thesis, firstly, the impact of transmitter tilting angles and multipath reflections are studied and for the first time, it is demonstrated that tilting the transmitter can be beneficial in VLP systems considering both line of sight (LOS) and non-line of sight transmission paths. With the transmitters oriented towards the center of the receiving plane, the received power level is maximized due to the LOS components. It is also shown that the proposed scheme offers a significant accuracy improvement of up to ~66% compared with a typical non-tilted transmitter VLP. The effect of tilting the transmitter on the lighting uniformity is also investigated and results proved that the uniformity achieved complies with the European Standard EN 12464-1. After that, the impact of transmitter position and orientation uncertainty on the accuracy of the VLP system based on the received signal strength (RSS) is investigated. Simulation results show that the transmitter uncertainties have a severe impact on the positioning error, which can be leveraged through the usage of more transmitters. Concerning a smaller transmitter’s position epochs, and the size of the training set. It is shown that, the ANN with Bayesian regularization outperforms the traditional RSS technique using the non-linear least square estimation for all values of signal to noise ratio. Furthermore, a novel indoor VLP system is proposed based on support vector machines and polynomial regression considering two different multipath environments of an empty room and a furnished room. The results show that, in an empty room, the positioning accuracy improvement for the positioning error of 2.5 cm are 36.1, 58.3, and 72.2 % for three different scenarios according to the regions’ distribution in the room. For the furnished room, a positioning relative accuracy improvement of 214, 170, and 100 % is observed for positioning error of 0.1, 0.2, and 0.3 m, respectively. Ultimately, an indoor VLP system based on convolutional neural networks (CNN) is proposed and demonstrated experimentally in which LEDs are used as transmitters and a rolling shutter camera is used as receiver. A detection algorithm named single shot detector (SSD) is used which relies on CNN (i.e., MobileNet or ResNet) for classification as well as position estimation of each LED in the image. The system is validated using a real-world size test setup containing eight LED luminaries. The obtained results show that the maximum average root mean square positioning error achieved is 4.67 and 5.27 cm with SSD MobileNet and SSD ResNet models, respectively. The validation results show that the system can process 67 images per second, allowing real-time positioning.A procura por sistemas de posicionamento interior (IPSs) de alta precisão tem crescido rapidamente devido ao seu interesse nas técnicas cada vez mais populares da Internet das Coisas, dispositivos móveis inteligentes e inteligência artificial. O IPS tornou-se um domínio de pesquisa promissor que tem atraído grande atenção devido aos seus benefícios em vários cenários de trabalho, como indústrias, locais públicos e navegação autónoma. Além disso, o IPS tem uma contribuição destacada no dia a dia de organizações, como, centros de saúde, aeroportos, supermercados, fábricas, locais subterrâneos, etc. As tecnologias baseadas em radiofrequência (RF) e comunicação óptica sem fio (OWC) podem ser adotadas para localização em ambientes interiores. Embora o sistema de posicionamento global (GPS) baseado em RF ofereça taxas de penetração mais altas com precisão reduzida (ou seja, na faixa de alguns metros), não funciona bem em ambientes interiores (e não funciona bem em certos casos como túneis, minas, etc.) devido ao sinal muito fraco e falta de acesso direto aos satélites. Por outro lado, o sistema baseado em luz conhecido como sistema de posicionamento de luz visível (VLP), como parte dos sistemas OWC, usa a infraestrutura de iluminação baseada em díodos emissores de luz (LEDs) pré-existentes, é um sistemas de baixo custo e alta precisão quando comprado com os sistemas baseados em RF. O VLP é uma tecnologia emergente que promete alta precisão, alta segurança, baixo custo de implantação, menor tempo de resposta e baixa complexidade relativa quando comparado ao posicionamento baseado em RF. No entanto, os sistemas VLP interiores, exibem algumas limitações, como, a reflexão multicaminho, inclinação do transmissor, posição do transmissor e incerteza de orientação, sombra/bloqueio humano e ruído, que têm como consequência o aumento do erro de posicionamento, e consequente redução da precisão do sistema. Portanto, é imperativo estudar as características dos diferentes canais VLP e modelá-los adequadamente para o duplo propósito de iluminação e localização. Esta tesa aborda, primeiramente, o impacto dos ângulos de inclinação do transmissor e reflexões multipercurso no desempenho do sistema de posicionamento. Demonstra-se que a inclinação do transmissor pode ser benéfica em sistemas VLP considerando tanto a linha de vista (LOS) como as reflexões. Com os transmissores orientados para o centro do plano recetor, o nível de potência recebido é maximizado devido aos componentes LOS. Também é mostrado que o esquema proposto oferece uma melhoria significativa de precisão de até ~66% em comparação com um sistema VLP de transmissor não inclinado típico. O efeito da inclinação do transmissor na uniformidade da iluminação também é investigado e os resultados comprovam que a uniformidade alcançada está de acordo com a Norma Europeia EN 12464-1. O impacto da posição do transmissor e incerteza de orientação na precisão do sistema VLP com base na intensidade do sinal recebido (RSS) foi também investigado. Os resultados da simulação mostram que as incertezas do transmissor têm um impacto severo no erro de posicionamento, que pode ser atenuado com o uso de mais transmissores. Para incertezas de posicionamento dos transmissores menores que 5 cm, os erros médios de posicionamento são 23.3, 15.1 e 13.2 cm para conjuntos de 4, 9 e 16 transmissores, respetivamente. Enquanto que, para a incerteza de orientação de um transmissor menor de 5°, os erros médios de posicionamento são 31.9, 20.6 e 17 cm para conjuntos de 4, 9 e 16 transmissores, respetivamente. O trabalho da tese abordou a investigação dos aspetos de projeto de um sistema VLP indoor no qual uma rede neuronal artificial (ANN) é utilizada para estimativa de posicionamento considerando um canal multipercurso. O estudo considerou a influência do ruído como indicador de desempenho para a comparação entre diferentes abordagens de projeto. Três algoritmos de treino de ANNs diferentes foram considerados, a saber, Levenberg-Marquardt, regularização Bayesiana e algoritmos de gradiente conjugado escalonado, para minimizar o erro de posicionamento no sistema VLP. O projeto da ANN foi otimizado com base no número de neurónios nas camadas ocultas, no número de épocas de treino e no tamanho do conjunto de treino. Mostrou-se que, a ANN com regularização Bayesiana superou a técnica RSS tradicional usando a estimação não linear dos mínimos quadrados para todos os valores da relação sinal-ruído. Foi proposto um novo sistema VLP indoor baseado em máquinas de vetores de suporte (SVM) e regressão polinomial considerando dois ambientes interiores diferentes: uma sala vazia e uma sala mobiliada. Os resultados mostraram que, numa sala vazia, a melhoria da precisão de posicionamento para o erro de posicionamento de 2.5 cm são 36.1, 58.3 e 72.2% para três cenários diferentes de acordo com a distribuição das regiões na sala. Para a sala mobiliada, uma melhoria de precisão relativa de posicionamento de 214, 170 e 100% é observada para erro de posicionamento de 0.1, 0.2 e 0.3 m, respetivamente. Finalmente, foi proposto um sistema VLP indoor baseado em redes neurais convolucionais (CNN). O sistema foi demonstrado experimentalmente usando luminárias LED como transmissores e uma camara com obturador rotativo como recetor. O algoritmo de detecção usou um detector de disparo único (SSD) baseado numa CNN pré configurada (ou seja, MobileNet ou ResNet) para classificação. O sistema foi validado usando uma configuração de teste de tamanho real contendo oito luminárias LED. Os resultados obtidos mostraram que o erro de posicionamento quadrático médio alcançado é de 4.67 e 5.27 cm com os modelos SSD MobileNet e SSD ResNet, respetivamente. Os resultados da validação mostram que o sistema pode processar 67 imagens por segundo, permitindo o posicionamento em tempo real.Programa Doutoral em Engenharia Eletrotécnic

A rare case on ovarian hyperstimulation syndrome in a spontaneous singleton pregnancy

Spontaneous form of ovarian hyperstimulation syndrome in pregnancy (OHSS) is extremely rare and characterized by gastro-intestinal symptoms and complication of shift of fluid in the third space. It is often associated with multiple gestations, hypothyroidism, polycystic ovarian syndrome and molar pregnancy. Treatment depends on the patient’s clinical condition. The aim of this case report is to bring into light a case of spontaneous OHSS in a healthy Indian pregnant woman that presented with pain abdomen, abdominal distension and vomiting at 14 weeks of gestation without any of the above-mentioned risk factors. Ultrasonography showed a single viable intrauterine pregnancy along with bilateral enlarged cystic ovaries, ascites and raised CA-125 levels. There was no history of ovulation induction in present and previous pregnancy. We successfully managed the patient conservatively with Dopamine agonist Cabergoline and she delivered a healthy baby at 33 weeks. Although spontaneous OHSS is a rare entity, it should be included in differential diagnosis of acute abdomen in pregnant women. OHSS can lead to life threatening complications, early diagnosis is required for proper management.  

PIERS calculator- predicting adverse maternal outcome in preeclampsia

Background: Preeclampsia is a multisystem, highly variable disorder unique to pregnancy. For preeclampsia arising remote from term, supportive and temporizing measures are used to improve perinatal outcome. However, the magnitude of the maternal risks associated with expectant management is unclear. The PIER (preeclampsia integrated estimate of risk) score is a recently designed tool which assesses maternal signs, symptoms, and laboratory findings to generate a valid and reliable algorithm for predicting maternal and perinatal outcome in patients with preeclampsia.Methods: The present study was a prospective hospital based observational study carried out in Department of Obstetrics and Gynecology, Sultania Zanana Hospital, Gandhi Medical College, Bhopal. A total of 125 women with preeclampsia who fulfilled the inclusion criteria were included in the study. Along with history and examination, all relevant and required investigations were done. The fullPIERS calculator was used to calculate the risk of adverse maternal outcome.Results: In the present study, 82(65.6%) women were in the low risk category and only 4 (4.87%) had adverse maternal outcome. High risk patients were 6 (4.8%) and amongst them 5 (83.33%) women had adverse maternal outcome (p-value <0.00001). The result was statistically significant in identifying high risk cases in our study.Conclusions: The fullPIERS calculator gave good results in prediction of adverse maternal outcome according to risk score in women with preeclampsia in our study. It will help the clinicians better manage the patients with preeclampsia specially remote from term and also help health workers in primary and secondary care centres to identify women who are or may become severely ill and who need specialist care and prevent delays in transporting these women to facilities where they can receive appropriate care

Ruptured caesarean scar ectopic pregnancy: a rare case report

Caesarean scar pregnancy is a rare type of ectopic pregnancy. Little is known about its incidence and natural history. With increasing incidence of caesarean section worldwide, more and more cases are diagnosed and reported.  We report a case of caesarean scar site ruptured ectopic pregnancy presented to emergency department with hypovolemic shock. Decision for emergency laparotomy was taken on the basis of clinical findings and ultrasonography. Hemoperitoneum of 2 litres with scar site rupture ectopic was seen. Evacuation of products along with repair of uterus in 2 layers with bilateral tubal ligation was done. It is the rarest kind of ectopic pregnancy and may lead to severe life threatening complications such as uterine rupture and severe hemorrhage or may have adverse effect on future fertility.

Transformation of Images Using Wavelet Transform For Image Watermarking of Text in Binary Images

DWT and DCT compress the image and generates a decomposed image use of those decomposed band has been demonstrated in this paper of watermarking. Image watermarking is important for transmition of secret data over communication channel.DWT ensures the security, however text hiding is slightly different and uses the transformation the other way round and hence enhances the complexity and also the dissolving capacity of the cover image as now the text data range gets equivalent to the image data range hence it gets settle down easily, on the other hand the secrete image still uses the dwt technique to get its range altered and hence the images gets settled down easily without revealing any information

Assessment of genetic diversity in pigeon pea (Cajanus cajan) using micro satellite markers

An effective way to use germplasm for genetic improvement is to be aware of the genetic variation among crop genotypes. The objective of the present study was to assess the genetic diversity and population structure of 30 genotypes of pigeonpea from populations that were collected from various sources. In order to show a new structure within the pigeonpea genetic pool and to give crucial information for pigeonpea breeding operations, the predetermined study's goal was to define pigeonpea genotypes using a microsatellite marker technique. The genomic DNA of 30 pigeon pea genotypes were amplified with 20 SSR primers that produced 46 amplified bands, out of which 30 band were polymorphic (65.21%) and 16 bands were monomorphic (34.82%). Primer CcM 2977 generated a maximum number of amplified bands, of which 2 bands were polymorphic. Among 20 primers, only 8 primers showed the highest polymorphism (100%) and 5 primers were monomorphic in nature. Average of 2.30 bands per primer was amplified. The dendrogram constructed from the pooled data revealed six distinct clusters of which five were solitary.  Cluster analysis of pigeon pea genotypes was based on Unweighted Pair Group Method with the Arithmetic average (UPGMA) method and the 30 pigeon pea genotypes were classified into six main groups. The present study indicated that the performance of SSR markers for the evaluation of genetic diversity could be beneficial for pigeon pea breeding. They could additionally be useful in genomic mapping research, developing pigeon pea cultivars with various genetics and reaping advanced crop productivity.

A prospective clinical trial to evaluate the role of very low dose mifepristone 10 mg in medical management of uterine leiomyoma in tertiary care hospital from North West India

Background: Uterine leiomyomas are the most common benign tumours of the uterus and also the most common benign solid tumor in female. It arises from the uterine smooth muscles (myometrium) but contain varying amount of fibrous connective tissue. Aim of study was to evaluate the efficacy of very low dose Mifepristone (10 mg) on leiomyoma volume and its related symptoms.Methods: This was a prospective clinical study. 30 women met with the inclusion criteria and giving informed consent for the study.Results: Mean myoma volume was 60.32±51.89 at initial visit and 36.13±48.54 at 3 months follow up visit with 40.1% reduction which was statistically significant difference (p < 0.001). Mean PBAC score in Group I was 155.53±21.70 at initial visit and 0.97±2.97 at 3 months follow up visit with 99.3% reduction which was statistically significant (p < 0.001).Conclusions: Mifepristone 10 mg is efficacious in term of control of bleeding, alleviation of pain related symptoms with few side effects. So low dose mifepristone can be used as a suitable option for women with symptomatic fibroids in perimenopausal periods or patients not willing or fit for surgery

A study of prevalence of tobacco use and related factors among medical students as per the Global Health Professions Student Survey protocol

Background: Physicians who smoke are less likely to ask patients about their smoking and initiate cessation interventions. Hence it is important to study the prevalence of tobacco use, attitude and training of health professional students. Objectives were to study prevalence and attitudes towards tobacco use and training related to tobacco cessation.Methods: Armed Forces Medical college-based cross-sectional survey by anonymous, self-administered questionnaire as per Global Health Professions Student Survey (GHPSS) was conducted. Data was compiled and analyzed for various variables as per the GHPSS questionnaire.Results: Forty-two percent of the students had ever smoked cigarettes and 24% were current smokers. Nearly one in five had tried their first cigarette before 20 years of age. Male gender was associated with smoking. There is a significant association between not smoking and support for smoking ban in public places. Almost all the respondents (98.1%) thought smoking should be banned in all enclosed public places. In light of 20.6% of all respondents who smoked in college buildings during past this year indicated a gap between their knowledge, attitude and behavior. There was a strong desire to quit smoking but only 42% reported receiving help/ advice to stop smoking. Only one in ten reported receiving formal training in smoking cessation techniques.Conclusions: The fight against tobacco can get a boost through interventions aimed at health care professional students. Active Interventions should be made to address smoking issues among medical students. Skill based medical school curriculum should incorporate and emphasize on acquiring effective smoking cessation skills

EFFECT ON MENTAL HEALTH AMONG UNDERGRADUATE COLLEGE STUDENTS OF INDIA DURING THE COVID-19 PANDEMIC: A CROSS-SECTIONAL MULTICENTRIC STUDY

Background: College students show higher prevalence of mental health issues as compared to the general population. Unfortunately, this year, students all over the world have to face, added pressure due to COVID-19. This study aimed to estimate the effect of COVID-19 pandemic and lockdown on the mental health of Medical and Engineering Students. Subjects and methods: The study was carried out at different medical and engineering colleges in Bihar, Delhi and Maharashtra, and Tamil Nadu. 699 responses were collected and analyzed during the study period. Data was collected by email/ online platform through Google form via non- probability Sampling Technique. Mental health status was determined by using Corona virus anxiety screening (CAS), GHQ (General Health Questionnaire)-12, GAD (General Anxiety Disorder)-7 scale and PHQ (Patient Health Questionnaire)-9 scales.369 (53%) MBBS and 330 (47%) Engineering students participated in the study. Results: Maximum participants in both groups did not have anxiety related to COVID-19 (MBBS (96.8%) and Engineering (95.2%). About two-third participants secured above cut off score i.e., MBBS (62.3%) and Engineering (64.8%) in GHQ-12. Approximately comparable proportion in both groups were found to have severe anxiety and depression (16% vs 20%), when applied GAD-7 and PHQ-9. Uncertainty in the timing of the exams/ Academic delay was found to be the most worrying factor (MBBS, 41.19% vs Engineering 31.82%). Conclusions: About two-thirds of medical and engineering students psychologically equally affected by current pandemic in our study. A student wellness clinic is the need of hour in current scenario, which is supported by mental health experts (Psychiatrists, Clinical Psychologists) and residents on rotation basiswhere all psychological problem including Stress, Anxiety, Interpersonal crisis, Relationship issues and Personality problems of the students are dealt effectively in institute campus near to student residential area