Bistatic SAR data acquisition and processing using SABRINA-X, with TerraSAR-X as the opportunity transmitter

This thesis investigates the acquisition and processing of Bistatic SAR data using SABRINA-X, and with TerraSAR-X as the transmitter of opportunity. SABRINA-X is an X-band receiver system that has been recently designed at the UPC Remote-Sensing Laboratory, while TerraSARX is a German satellite for SAR-based active remote-sensing. Prior to the particular case of acquiring TerraSAR-X signals, the hardware aspects of SABRINAX have been investigated further, and improved as necessary (or suggested for up-gradation in future). Two successful data acquisitions have been carried out, to obtain bistatic SAR images of the Barcelona harbor, with the receiver set-up at the close-by Montjuïc hill. Each acquisition campaign necessitated an accurate prediction of the satellite overpass time and precise orientation of the antennas to acquire the direct signal from the satellite and the backscattered signals off the viewed terrain. The thesis also investigates the characteristics of the acquired signals, which is critical as regards the subsequent processing for imaging and interferometric applications. The hardware limitations, combined with ‘off-nominal’ transmissions of the satellite, necessitate improved range processing of the acquired signals. The thesis expounds the possible range compression techniques, and suggests ways for improved compression, thereby improving the quality of the subsequently processed images

Role of Human Capital in Market Orientation – Innovation Relationship

Academics and practitioners have considered and regarded innovation as a  source to gain sustainable competitive advantage (SCA) over rival firms. Although market orientation (MO) and innovation have been studied and found to impact a firm’s ability to innovate separately, how they interact with each other has not been studied before. Drawing from the theory of organizational learning, this study proposes that human capital (HC) mediates the relationship between MO and innovation. The proposed relationship was empirically tested using data collected from managers of the textile sector of Pakistan. The results reveal that human capital and market orientation separately affect innovation while HC partially mediates MO and innovation relationship. Practical and future research implications of the study have also been discussed

Bistatic SAR data acquisition and processing using SABRINA-X, with TerraSAR-X as the opportunity transmitter

This thesis investigates the acquisition and processing of Bistatic SAR data using SABRINA-X, and with TerraSAR-X as the transmitter of opportunity. SABRINA-X is an X-band receiver system that has been recently designed at the UPC Remote-Sensing Laboratory, while TerraSARX is a German satellite for SAR-based active remote-sensing. Prior to the particular case of acquiring TerraSAR-X signals, the hardware aspects of SABRINAX have been investigated further, and improved as necessary (or suggested for up-gradation in future). Two successful data acquisitions have been carried out, to obtain bistatic SAR images of the Barcelona harbor, with the receiver set-up at the close-by Montjuïc hill. Each acquisition campaign necessitated an accurate prediction of the satellite overpass time and precise orientation of the antennas to acquire the direct signal from the satellite and the backscattered signals off the viewed terrain. The thesis also investigates the characteristics of the acquired signals, which is critical as regards the subsequent processing for imaging and interferometric applications. The hardware limitations, combined with ‘off-nominal’ transmissions of the satellite, necessitate improved range processing of the acquired signals. The thesis expounds the possible range compression techniques, and suggests ways for improved compression, thereby improving the quality of the subsequently processed images

Comparison of CNNs and Vision Transformers-Based Hybrid Models Using Gradient Profile Loss for Classification of Oil Spills in SAR Images

Oil spillage over a sea or ocean surface is a threat to marine and coastal ecosystems. Spaceborne synthetic aperture radar (SAR) data have been used efficiently for the detection of oil spills due to their operational capability in all-day all-weather conditions. The problem is often modeled as a semantic segmentation task. The images need to be segmented into multiple regions of interest such as sea surface, oil spill, lookalikes, ships, and land. Training of a classifier for this task is particularly challenging since there is an inherent class imbalance. In this work, we train a convolutional neural network (CNN) with multiple feature extractors for pixel-wise classification and introduce a new loss function, namely, “gradient profile” (GP) loss, which is in fact the constituent of the more generic spatial profile loss proposed for image translation problems. For the purpose of training, testing, and performance evaluation, we use a publicly available dataset with selected oil spill events verified by the European Maritime Safety Agency (EMSA). The results obtained show that the proposed CNN trained with a combination of GP, Jaccard, and focal loss functions can detect oil spills with an intersection over union (IoU) value of 63.95%. The IoU value for sea surface, lookalikes, ships, and land class is 96.00%, 60.87%, 74.61%, and 96.80%, respectively. The mean intersection over union (mIoU) value for all the classes is 78.45%, which accounts for a 13% improvement over the state of the art for this dataset. Moreover, we provide extensive ablation on different convolutional neural networks (CNNs) and vision transformers (ViTs)-based hybrid models to demonstrate the effectiveness of adding GP loss as an additional loss function for training. Results show that GP loss significantly improves the mIoU and F$_1$ scores for CNNs as well as ViTs-based hybrid models. GP loss turns out to be a promising loss function in the context of deep learning with SAR images

Caveat Emptor:The Risks of Using Big Data for Human Development

"Big Data" has the potential to facilitate sustainable development in many sectors of life such as education, health, agriculture, and in combating humanitarian crises and violent conflicts. However, lurking beneath the immense promises of Big Data are some significant risks such as 1) the potential use of Big Data for unethical ends; 2) its ability to mislead through reliance on unrepresentative and biased data; and 3) the various privacy and security challenges associated with data (including the danger of an adversary tampering with the data to harm people). These risks can have severe consequences and a better understanding of these risks is the first step towards their mitigation of these risks. In this article, we highlight the potential dangers associated with using Big Data, particularly for human development

Mechanical Performance of Polymeric ARGF-Based Fly Ash-Concrete Composites: A Study for Eco-Friendly Circular Economy Application

At present, low tensile mechanical properties and a high carbon footprint are considered the chief drawbacks of plain cement concrete (PCC). At the same time, the combination of supplementary cementitious material (SCM) and reinforcement of fiber filaments is an innovative and eco-friendly approach to overcome the tensile and environmental drawbacks of plain cement concrete (PCC). The combined and individual effect of fly ash (FA) and Alkali resistance glass fiber (ARGF) with several contents on the mechanical characteristics of M20 grade plain cement concrete was investigated in this study. A total of 20 concrete mix proportions were prepared with numerous contents of FA (i.e., 0, 10, 20, 30 and 40%) and ARGF (i.e., 0, 0.5, 1 and 1.5%). The curing of these concrete specimens was carried out for 7 and 28 days. For the analysis of concrete mechanical characteristics, the following flexural, split tensile, and compressive strength tests were applied to these casted specimens. The outcomes reveal that the mechanical properties increase with the addition of fibers and decrease at 30 and 40% replacement of cement with fly ash. Replacement of cement at higher percentages (i.e., 30 and 40) negatively affects the mechanical properties of concrete. On the other hand, the addition of fibers positively enhanced the flexural and tensile strength of concrete mixes with and without FA in contrast to compressive strength. In the end, it was concluded that the combined addition of these two materials enhances the strength and toughness of plain cement concrete, supportive of the application of an eco-friendly circular economy. The relationship among the mechanical properties of fiber-reinforced concrete was successfully generated at each percentage of fly ash. The R-square for general relationships varied from (0.48–0.90) to (0.68–0.96) for each percentage of FA fiber reinforced concrete. Additionally, the accumulation of fibers effectively boosts the mechanical properties of all concrete mixes.publishedVersio

Advances in Diagnosis and Treatment for SARS-CoV-2 Variants

The COVID-19 pandemic’s epidemiological and clinical characteristics have been affected in recent months by the introduction of SARS-CoV-2 variants with unique spikes of protein alterations. These variations can lessen the protection provided by suppressing monoclonal antibodies and vaccines, as well as enhance the frequencies of transmission of the virus and/or the risk of contracting the disease. Due to these mutations, SARS-CoV-2 may be able to proliferate despite increasing levels of vaccination coverage while preserving and enhancing its reproduction efficiency. This is one of the main strategies in tackling the COVID-19 epidemics, the accessibility of precise and trustworthy biomarkers for the SARS-CoV-2 genetic material and also its nucleic acids is important to investigate the disease in suspect communities, start making diagnoses and management in symptomatic or asymptomatic persons, and evaluate authorization of the pathogen after infection. Quantitative reverse transcriptase polymerase chain reaction (qRT-PCR) for virus nucleic acid identification is still the most effective method for such uses due to its sensitivity, quickness, high-throughput sequencing capacity, and trustworthiness. It is essential to update the primer and probe sequences to maintain the recognition of recently emerging variations. Concerning viral variations could develop that are dangerously resistant to the immunization induced by the present vaccinations in coronavirus disease 2019. Additionally, the significance of effective public health interventions and vaccination programs will grow if some variations of concern exhibit an increased risk of transmission or toxicity. The international reaction must’ve been immediate and established in science. These results supported ongoing efforts to prevent and identify infection, as well as to describe mutations in vaccine recipients, and they suggest a potential risk of illness following effective immunization and transmission of pathogens with a mutant viral

Polycystic Ovary Syndrome: It’s Not Just Infertility

Polycystic ovary syndrome (PCOS) is a heterogeneous endocrine issue described by unpredictable menses, hyperandrogenism, and polycystic ovaries (PCO). The commonness of PCOS changes relying upon which measures are utilized to conclude yet is just about as high as 15–20% when the European culture for human propagation and embryology/American culture for regenerative medication rules are utilized. Clinical signs incorporated grown-ups incorporate sort 1 diabetes, type 2 diabetes, and gestational diabetes. Insulin opposition influences half 70% of ladies with PCOS prompting a few comorbidities including metabolic condition, hypertension, dyslipidemia, glucose narrow-mindedness, and diabetes. Studies show that ladies with PCOS are bound to have expanded coronary corridor calcium scores and expanded carotid intima-media thickness. Psychological wellness problems including despondency, uneasiness, bipolar turmoil, and voraciously consuming food issues additionally happen all the more habitually in ladies with PCOS. Weight reduction works on feminine abnormalities, indications of androgen abundance, and barrenness the board of clinical appearances of PCOS incorporates oral contraceptives for feminine inconsistencies and hirsutism. Spironolactone and finasteride are utilized to treat indications of androgen overabundance

SuprasellarArachnoid Cyst as a Cause of Triventricular Hydrocephalus, Found Incidentally During Endoscopic Third Ventriculostomy

Background: Arachniod cyst is a rare congenital disorder of the brain accounting 1% of all intracranial masses. They may also be acquired following head trauma, meningitis, tumors or surgery. They may be the cause of triventricular hydrocephalus (TVH). It occupies the third ventricle so flow of CSF is obstructed at aqueduct of Sylvius. Per operatively, it differs from colloid cyst in consistency, its capsule is transparent and blood vessels are visible. Objectives: To determine the frequency of suprasellar arachnoid cyst as cause of triventricular hydrocephalus and outcome of ventriculocystocisternotomy performed for these cysts at Lady Reading Hospital, Peshawar. Materials and Methods: A retrospective study of 18 cases who undergone ETV for congenital TVH from January, 2013 to December 2015 at Neurosurgery department LRH was performed. On pre operative CT scan brain they were having triventricular hydrocephalus. Ventriculocysto-cisternotomy was performed in all these cases. Biopsy was taken in all cases. Results: Out of these 18 cases, 11 (61%) were males. The presenting symptoms in our study were that infants presented with increased head circumference (n = 3) 16.6%. In pediatric and middle age group the symptoms were those of elevated ICP (n = 13) 72.22%. No endoscopic complication occurred during the procedure except for clinically non-significant bleeds. We followed all cases for a period of 6 months. Clinical and radiological improvement occurred in all cases. Conclusion: Arachnoid cyst should also be considered as a differential for congenital TVH. Endoscopic Ventriculocystocisternotomy is the treatment option of choice forsuprasellararachnoid cyst.  Abbreviations: TVH: Triventricular Hydrocephalus. CSF: Cerebral Scleral Fluid. ICP: Intracranial Pressure. AC: Arachnoid Cyst. SSCs: Suprasellar arachnoid cysts. VC: Ventriculocystostomy. VCC: Ventriculocystocisternotomy. CT: Computer Tomography