57 research outputs found
Experimental evaluation of long term evolution-based NC OFDM secondary-to-secondary interference
No full textScarcity of spectrum resources, inefficient spectrum usage and the inflexibility of the current spectrum assignment are few of the major roadblocks in the development of new wireless communication standards. Secondary spectrum sharing has become a viable solution to alleviate this problem. Secondary users are unlicensed devices that use opportunistic spectrum access to identify vacant frequency bins and thereby utilize the spectrum. For advanced wireless communication standards like the Long Term Evolution (LTE) which primarily calls for higher data rates, evaluation of design parameters for ensuring efficient coexistence of heterogeneous secondary users and guaranteeing acceptable minimum level of performance becomes essential. Additionally, the understanding of the interference between secondary users occupying adjacent frequency bands for their transmission is imperative. This thesis focuses on the coexistence of secondary users in the same band assuming that the primary spectrum is found available. By Implementing two Non Contiguous Orthogonal Frequency Division Multiplexing ( NC-OFDM) based secondary transmitters on a real time platform, the design parameters that need to be considered to ensure efficient coexistence have been identified and investigated. The performance degradations observed at a particular secondary link due to presence of another interfering secondary link occupying adjacent frequency bands for its transmission have also been studied. This thesis also focuses on implementation of algorithms to modify the existing NC-OFDM transmission at the secondary transmitter end to reduce its Interference effects on the other secondary links operating within the same band. The focus is on an LTE-based Secondary Non Contiguous Orthogonal Frequency Division Multiplexing Transceiver on a Real Time Platform developed by National Instruments. The various blocks needed to design a real time LTE based communications links are discussed. An experimental LTE-to-LTE interference analysis based on the Real Time Platform and the designed system is presented.M.S.Includes bibliographical referencesby Ajay Ramkumar Iye
Regulation of senescence in cancer and aging
No full textCo-author Charusheila Ramkumar is a student in the Cell Biology program in the Graduate School of Biomedical Sciences (GSBS) at UMass Medical School.Senescence is regarded as a physiological response of cells to stress, including telomere dysfunction, aberrant oncogenic activation, DNA damage, and oxidative stress. This stress response has an antagonistically pleiotropic effect to organisms: beneficial as a tumor suppressor, but detrimental by contributing to aging. The emergence of senescence as an effective tumor suppression mechanism is highlighted by recent demonstration that senescence prevents proliferation of cells at risk of neoplastic transformation. Consequently, induction of senescence is recognized as a potential treatment of cancer. Substantial evidence also suggests that senescence plays an important role in aging, particularly in aging of stem cells. In this paper, we will discuss the molecular regulation of senescence its role in cancer and aging. The potential utility of senescence in cancer therapeutics will also be discussed
RAMKUMAR MUKHAPADHYAYER ‘DHANAPATIR SINHALYATRA’ : NABARUPE CHANDIMANGAL/ রামকুমার মুখোপাধ্যায়ের ‘ধনপতির সিংহলযাত্রা’ : নবরূপে চন্ডীমঙ্গল
No full textoai:ojs2.tirj.org.in:article/2Ramkumar Mukherjee\u27s novel \u27Dhanpati\u27s Sinhala Yatra\u27 is also medieval in terms of language. The novel has been reimagined by Chandimangal. Ramkumar Mukherjee has adopted the first part of the narrative of the merchant section in his novel. From Dhanpati\u27s Sinhala Yatra to captivity. Here, the novelist has looked back at medieval Bengal and Bengalis from a distance of several centuries, keeping Mukund\u27s poetry in front of him. He has made no attempt to drag the past into the present. Nor has he taken the present into the past and placed it there. In this book, the past cannot be seen in the present and the present in the past. A pure historical setting has been created where there is no shadow of the twenty-first century. Chapters such as the lifting of the Saptadinga, Dhanpati\u27s journey to the Dingaghata, Ajay Yatra, Muktabeni, and the journey of rivers and streams describe extinct rivers, towns, etc. The novel contains themes such as mythological consciousness, religious ideals, and a reevaluation of divine consciousness. Dhanpati traveled to the southern country in the hope of prosperity. However, his fate and destiny were determined by the hideous plots and cruelty of two goddesses. Ignoring many ominous signs and the desperate pleas of Khulna, Dhanpati has to travel helplessly towards the inevitable end. This is his destiny. Ramkumar Mukherjee has presented the novel \u27Dhanpati\u27s Singhal Yatra\u27 in a magical bond of intense fascination with the tradition of Bengali cultural heritage. The novel has a unique and modern reconstruction of the well-known Afghan poem of the medieval \u27Chandimangal\u27. The novelist has kept the basic structure of the story intact here, but has analyzed the psychological depth of the characters and the socio-economic context of the time from a modern perspective. As a result, it emerges as a picture of the conflict between man and time instead of the story of the greatness of the Goddess. In the novel, Dhanpati is a prosperous merchant of Ujjainnagar, but he has endless questions and doubts about the social system of the time. He wants to magnify the efforts and logic of man instead of the miracles of the conventional gods and goddesses. This rational mind has taken him against the conventional beliefs and conventional customs. And later it has become the main reason for the conflict in his life. On the king\u27s orders, Dhanpati has to undertake a journey to Sinhala despite his reluctance. Before the journey, the wish of his husband for his well-being did not open, so when the puja of Goddess Chandi was organized, the rational, confident, and realistic leader trampled the auspicious place of the Goddess with contempt. To him, the greatness of the Goddess is irrational and miraculous. However, the author portrays this insult not only as an insult, but as a clash between traditional beliefs and modern logic. The novel is not just a religious story, but also a story of human survival in the face of adversity. Overall, the novel has become a reinterpretation of the medieval \u27Chandimangal\u27 poem
HCI in interactive segmentation: Human-computer interaction in interactive segmentation of CT images for radiotherapy
No full textMechatronic Desig
Ekaler konthe, sekaler kothon : ramkumar mukhopadhyayer ‘Dhonopotir singhol jatra’/ একালের কণ্ঠে, সেকালের কথন : রামকুমার মুখোপাধ্যায়ের ধনপতির সিংহল যাত্রা
No full textThe trend of reconstruction or renewal in literature and art is something new. No It is possible to break the boundaries of any subject through innovation. This is a natural tendency of any culture. This trend has started in Bengali literature long ago. An attempt has been made to break the conventional meditation concept and tradition of \u27Charyagiti\u27 or \u27Mangalkabhya\u27 and show it in a new light. Which has been reflected in various branches of literature. For example, drama, poetry, novels, short stories. The style or form of literature has been written in new ways. In keeping with the times, people have tried to grasp tradition in the light of thought and consciousness. The trend of innovation is flowing in Bengali literature from natural interest, desire and the need for pleasure. After the 19th century, the 20th century and even after the 21st century, that trend has not stopped. Keeping the literary elements of ancient and medieval times in front, he analyzed and explored the individual\u27s own thoughts. One such novelist in 21st century Bengali literature is \u27Ramkumar Mukhopadhyay\u27.
He has made the elements of past history special by breaking them up with his artistic vision. He has written novels like \u27Dhanpati\u27s Singhal Yatra\u27 and \u27Har-Parvati Katha\u27, focusing on the medieval theme, \u27Mangalkavya\u27, which is ingrained in the Bengali consciousness and mind two. We will shed light on these characteristics of the author\u27s innovation and modern thinking in the article \u27In the Voice of a Time, When in Ramkumar Mukherjee\u27s Novels of a Time Selected\u27. 
Smurf2 suppresses B-cell proliferation and lymphomagenesis by mediating ubiquitination and degradation of YY1
No full textFirst author Charusheila Ramkumar is a student in the Cell Biology program in the Graduate School of Biomedical Sciences (GSBS) at UMass Medical School.About half of patients with diffuse large B-cell lymphoma (DLBCL) do not respond to or relapse soon after the standard chemotherapy, indicating a critical need to better understand the specific pathways perturbed in DLBCL for developing effective therapeutic approaches. Mice deficient in the E3 ubiquitin ligase Smurf2 spontaneously develop B-cell lymphomas that resemble human DLBCL with molecular features of germinal centre or post-germinal centre B cells. Here we show that Smurf2 mediates ubiquitination and degradation of YY1, a key germinal centre transcription factor. Smurf2 deficiency enhances YY1-mediated transactivation of c-Myc and B-cell proliferation. Furthermore, Smurf2 expression is significantly decreased in primary human DLBCL samples, and low levels of Smurf2 expression correlate with inferior survival in DLBCL patients. The Smurf2-YY1-c-Myc regulatory axis represents a novel pathway perturbed in DLBCL that suppresses B-cell proliferation and lymphomagenesis, suggesting pharmaceutical targeting of Smurf2 as a new therapeutic paradigm for DLBCL
Smurf2 regulates the senescence response and suppresses tumorigenesis in mice
No full textFirst author Charusheila Ramkumar is a student in the Cell Biology program in the Graduate School of Biomedical Sciences (GSBS) at UMass Medical School.The E3 ubiquitin ligase Smurf2 mediates ubiquitination and degradation of several protein targets involved in tumorigenesis and induces senescence in human cells. However, the functional role of Smurf2 in tumorigenesis has not been fully evaluated. In this study, we generated a mouse model of Smurf2 deficiency to characterize the function of this E3 ligase in tumorigenesis. Smurf2 deficiency attenuated p16 expression and impaired the senescence response of primary mouse embryonic fibroblasts. In support of a functional role in controlling cancer, Smurf2 deficiency increased the susceptibility of mice to spontaneous tumorigenesis, most notably B cell lymphoma. At a premalignant stage of tumorigenesis, we documented a defective senescence response in the spleens of Smurf2-deficient mice, consistent with a mechanistic link between impaired senescence regulation and increased tumorigenesis. Taken together, our findings offer the genetic evidence of an important tumor suppressor function for Smurf2
Towards Real-Time Human Pose Estimation For Mobile Device
No full textHuman pose estimation, a challenging computer vision task of estimating various human body joints' locations, has a wide range of applications such as pedestrian tracking for autonomous cars, baby monitoring, video surveillance, human action recognition, virtual reality, gaming, gait analysis, etc. A majority of the research on the development of models for the task of human pose estimation has been focused on improving the accuracy of the task which also increases the complexity of the models. These models demand devices with high computational power to be deployed for real-world applications. Even though a lot of research has been focused on estimating the human pose from monocular images taken from cameras, the complexity of the models makes them impossible to be implemented on edge devices and embedded devices like mobile phones that have built-in cameras. This reduces the scope of applications where human pose estimation can be used. To address the issue, the research focuses on improving the performance of a baseline human pose estimation architecture by reducing the model size(number of parameters) and thereby its inference time without a significant loss in the accuracy. To improve the performance of the model, a structured Bayesian compression algorithm is used and the network is compressed by engineering the model based on the uncertainty of the parameters. The results show that the Bayesian compression method reduces the model size by around 65 percent with only a very little drop in the model accuracy. Also, the comparison of the inference time of the original baseline and the compressed model in an android device shows that the inference time is reduced by around 50 percent because of the reduction in the number of operations in the compressed model architecture.Mechanical Engineering | Vehicle Engineerin
Transmitter measurements and analysis of frame synchronization of an Impulse Radio Ultra-wideband system
No full textUltra-wideband (UWB) is a promising radio technology which is well suited to low power short-range wireless applications. At Holst Centre/imec, there is a research program on the design and implementation of ultra low power, Impulse Radio-UWB (IR-UWB) wireless systems suitable for audio streaming and real time localization systems. Some key technology challenges for IR-UWB systems are Direct Current (DC) power consumption, Link-budget and Quality of Service (QoS). The first part of this thesis focuses on measurement of DC power consumption; transmit output power and spectrum using the IR-UWB transmitter. As the hardware supports several modes, an automated measurement setup with programmable parameters has been created. In the second part, a mathematical model for the preamble and Start of Frame Delimiter (SFD) detection stages of the receiver operation is provided. This part of the receiver is a critical one and is challenging for IR-UWB type of signals due to the low transmit power. A method to estimate the signal to noise ratio (SNR) per pulse from the output of the preamble detection block is proposed. A theoretical approach for setting the threshold for SFD detection is described. It is shown through simulations that this method of threshold setting provides a significant improvement in receiver performance.Electrical EngineeringTelecommunicationsElectrical Engineering, Mathematics and Computer Scienc
Investigation of resin and steel reinforced resin behaviour under quasi-static and cyclic loading in oversized IBCs
No full textInjection Bolted Connections (IBC) are connections in which the cavity between the bolts and the plates (hole clearance) is filled with two-component epoxy resin. The oversized hole clearances allow for the reuse of all the structural elements in composite structures. Due to larger hole clearance, the possibility of slip occurrence in the connection is higher and hence there is a need to study the behaviour of resin and steel-reinforced resin (SRR) under cyclic loading. A custom made setup with 3 and 6 mm oversize that replicates the nominal bearing stress experienced by the resin in a double lap shear joint was used to study the behaviour of the resin/SRR under cyclic loading. The slip obtained from cyclic loading is extrapolated for 5 million cycles to check if maximum slip exceeds the failure criterion of 0.3 mm and slip range exceeds the failure criterion of 0.1 mm over 5 million cycles. Numerical modelling was done to see if the results (initial stiffness) obtained from the experiments can be replicated by the material models for static and one cycle loading with the help of a reasonable friction coefficient between the steel and resin surfaces. Good sets of results were obtained for all the tested stress ranges. On extrapolating to 5 million cycles, resin specimens with 3 mm hole clearance failed at a stress range of 200 MPa and resin specimens with 6 mm hole clearance failed at a stress range of 150 MPa. SRR specimens with 6 mm hole clearance failed at a stress range of 200 MPa. From numerical modelling, a good correlation was found between the force vs displacement curve obtained from the experiments to the curve obtained from the numerical model.Civil Engineering | Structural Engineering | Steel and Timber Constructio
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