Scalable Video Coding

International audienceWith the evolution of Internet to heterogeneous networks both in terms of processing power and network bandwidth, different users demand the different versions of the same content. This has given birth to the scalable era of video content where a single bitstream contains multiple versions of the same video content which can be different in terms of resolutions, frame rates or quality. Several early standards, like MPEG2 video, H.263, and MPEG4 part II already include tools to provide different modalities of scalability. However, the scalable profiles of these standards are seldom used. This is because the scalability comes with significant loss in coding efficiency and the Internet was at its early stage. Scalable extension of H.264/AVC is named scalable video coding and is published in July 2007. It has several new coding techniques developed and it reduces the gap of coding efficiency with state-of-the-art non-scalable codec while keeping a reasonable complexity increase. After an introduction to scalable video coding, we present a proposition regarding the scalable functionality of H.264/AVC, which is the improvement of the compression ratio in enhancement layers (ELs) of subband/wavelet based scalable bitstream. A new adaptive scanning methodology for intra frame scalable coding framework based on subband/wavelet coding approach is presented for H.264/AVC scalable video coding. It takes advantage of the prior knowledge of the frequencies which are present in different higher frequency subbands. Thus, by just modification of the scan order of the intra frame scalable coding framework of H.264/AVC, we can get better compression, without any compromise on PSNR

Real-time edge analytics and concept drift computation for efficient deep learning from spectrum data

Cloud managed wireless network resource configuration platforms are being developed for efficient network utilization. These platforms can improve their performance by utilizing real-time edge analytics of key wireless metrics, such as wireless channel utilization (CU). This paper demonstrates a real-time spectrum edge analytics system which utilizes field programmable gate array (FPGA) to process in real-time hundreds of millions of streaming inphase and quadrature (IQ) samples per second. It computes not only mean and maximum values of CU but also computes histograms to obtain probability distribution of CU values. It sends in real-time these descriptive statistics to an entity which collects these statistics and utilises them to train a deep learning model for prediction of future CU values. Even though utilization in a wireless channel can often exhibit stable seasonal patterns, they can be affected by uncertain usage events, such as sudden increase/decrease in channel usage within a certain time period. Such changes can unpredictably drift concept of CU data (underlying distribution of incoming CU data) over time. In general, concept drift can deteriorate the prediction performance of deep learning models which in turn can impact the performance of cloud managed resource allocation solution. This paper also demonstrates a real-time concept drift computation method which measures the changes in the probability distribution of CU data. Our implemented demonstration includes: 1) spectrum analytics and concept drift computation device which is realized in practical implementation by prototyping it on a low-cost ZedBoard with AD9361 RF transceiver attached to it. ZedBoard is equipped with a Xilinx Zynq-7000 system on chip; 2) a laptop which is connected to the Zedboard and it provides graphical real-time displays of computed CU values, CU histograms, and concept drift computation values. A laptop is also used to develop a deep learning based model for prediction of future CU values. For the INFOCOM we will show a live demonstration of the complete prototyped system in which the device performs real-time computations in an unlicensed frequency channel following the implemented algorithms on the FPGA of a Zedboard

Synthesis, spectral analysis and pharmacological study of N'- substituted-2-(5-((2,4-dimethylphenoxy)methyl)-1,3,4-oxadiazol-2-ylthio)acetohydrazides

A series of molecules bearing multiple functional groups were synthesized to study their antibiotic effect against Gram-positive and Gram-negative bacteria and lipoxygenase activity as well. 2,4-Dimethylcarbolic acid (1) was refluxed with ethyl 2-bromoacetate to synthesize ethyl 2-(2,4-dimethylphenoxy)acetate (2). Compound 2 was converted to the corresponding hydrazide 3, again on refluxing with hydrazine. The compound 5-((2,4-dimethylphenoxy)methyl)-1,3,4-oxadiazol-2-thiol (4) was synthesized by the reaction of 3 and CS2 in the presence of KOH. Compound 4 was further converted to the corresponding ester 5 and then 2-(5-((2,4-dimethylphenoxy)methyl)-1,3,4-oxadiazol-2-ylthio)acetohydrazide (6). The final molecules N'-substituted-2-(5-((2,4-dimethylphenoxy)methyl)-1,3,4-oxadiazol-2-ylthio)acetohydrazide, 8a-m, bearing ether, 1,3,4-oxadiazole, thioether, hydrazone and azomethine functional groups were synthesized by stirring the aryl carboxaldehydes 7a-m with 6 in methanol at room temperature. The depicted structures of all synthesized molecules were corroborated by IR, 1H-NMR and EIMS spectral data analysis. 8m and 8i showed substantial antibacterial activity and lipoxygenase inhibitory activity, respectively

Flow cytometric analysis of childhood leukemias

Objective: To collect demographic data for childhood (less than 15 years) leukemias in Karachi, describe the accuracy of the cell surface markers routinely used in the flow cytometric analysis of leukemic cells and arrive at an ideal panel of antibodies for analyzing leukemic samiples. Materials and Methods: Data from 62 consecutive cases of childhood leukemias referred to the Department of Pathology, Aga Khan University Hospital. (AKUH) between January 1995 and December 1998 was analyzed using Epi Info Version 6. Flow cytometry on all samples was performed using standard protocols. Results: The mean age of patients was 8.2 years and 49 (79%) were males. Fifty (81%) had acute lymphoblastic leukemias of which 50% were CD1O positive and 24% CD10 negative Pre-B cell leukemias. Among all Pre B cell All 98% were positive for CD19, 96% for CD22, 89% for HLA-DR and 67% for CD10. Of the 10 AML cases, 100% were positive for CD33, 90% for CD13, 80% for CD19 and 70% for HLA-DR. Conclusion: The mean age in this study population was significantly higher and percentage of CD10 positive Pre-B All is lower than that in the West. Both these factors might be responsible for the poorer prognosis of these patients. It is not possible to specify a minimum or maximum panel of antibodies that should be used for phenotyping all cases of childhood leukemias. A certain degree or redundancy is essential in any panel of antibodies used for flow cytometry of leukemias

Diagnostic Surgical Pathology: the importance of Second Opinion in a Developing Country

Objective: To review the cases sent to the section of histopathology, Aga Khan Universty (AKU) for second opinion and see whether there are significant differences in the original outside diagnosis and the subsequent diagnosis submitted by us. Methods: A retrospective study of all consecutive cases for second opinion in the form of paraffin blocks from 1st Novemver 2001 to 31st July 2002. The primary submitted diagnosis in each case was compared with the subsequent AKU diagnosis. Results: The study included a total of 381 cases. However, in 45 cases (11.81%), initial histopathological diagnosis was not provided. Out of the remaining 336 cases, there were differences between the original diagnosis and the subsequent AKU diagnosis in 120 cases (35.71%). Out of these 120 cases, immunohistochemistry was performed in 65 cases (54.16%) only. Conclusion: In a developing country like Pakistan, where few laboratories are equipped to function as modern histopathology units, second opinion on difficult cases is very important. Worldwide, the concept of second opinion in surgical pathology is well established

Histological pattern of central nervous system neoplasms

Objective: To see in a large series of patients the histological pattern of CNS neoplasms and to provide a comprehensive data about the frequency of CNS neoplasms in Pakistani patients and to give a clearer idea about their prevalence. Method: Retrospective study of all consecutive cases of CNS neoplasms diagnosed at The Aga Khan University Hospital (AKUH) between 1st January 1994 and 31st December, 1999. Setting: The section of Histopathology, AKUH, Karachi. Observation: Our series included a large number of cases i.e., 1110 . There are very few local studies on CNS tumours and none so large . Our data was correlated with published Western and Pakistani data . Glial tumours were the commonest primary CNS neoplasms followed by meningiomas . Among glial tumours , astrocytomas comprised the largest group and the majority were high grade (Ill and IV ) astrocytomas. Percentages of anaplastic oligodendrogliomas and ependymomas were also significant. Male to female ratio was 1.6:1. However, meningiomas were more common in females. Almost half of the CNS tumours in patients 15 years or younger were in the posterior cranial fossa . Metastatic tumours were much lower as compared to the West. Conclusion: Except for the high percentages of anaplastic oligodendrogliomas and ependymomas and the low percentage of metastatic tumours, most of our findings roughly correspond with the published data

Transitional cell carcinomas of the urinary bladder. A histopathological study

Objective: To determine the histological grading and muscle invasion in Transitional Cell Carcinomas of the Urinary Bladder; and to evaluate whether any correlation exists between tumour grade and muscle invasion. Method: A Retrospective study of all consecutive cases of Transitional Cell Carcinomas of the Urinary Bladder diagnosed at Aga Khan University Hospital between 1st Jan 1997 and 31st Dec 2000. Results: This study included 495 cases of Transitional Cell Carcinoma of the Urinary Bladder. M: F ratio was 4:1. Ages of patients ranged from 30 years to 87 years. Mean age in males was 59.1 years and in females 58.8 years. Forty four percent cases were Grade II, and 29.5% Grade Ill. None of the Grade I lesions were invasive, 10% Grade II tumours, 61 .41% of Grade Ill and all Grade IV tumours were invasive. Conclusion: There is a definite correlation between advancing tumour grade and muscle invasion

Breast Diseases: a histopathological analysis of 3279 Cases at a Tertiary Care Center in Pakistan

Objective: To know the frequency of breast diseases in Pakistani females. Methods: A retrospective analysis of 3279 breast specimens received over a period of 4 years (1 993-1996) at the department of pathology, the Aga Khan University Hospital. Results: Out of a total of 3279 breast specimens, common breast lesions included infiltrating duct carcinoma 37%, followed by fibro adenoma 16.95%, fibrocystic change13.96%, mastitis 6.83% and duct ectasia 5.33%. Majority of the cases of infiltrating duct carcinoma were encountered in the 5th and 6th decades of life. Tumour size was 2 or \u3e2 cms. in 93% of cases and 40% of them showed 3 or \u3e3 positive lymph nodes. Grade I tumours were 11.38%, grade 11 59.17% and grade Ill tumours 29.47%. Correlation of grade with lymph node metastases (3 or \u3e3+ve nodes) showed 15 cases (1.53%) of grade 1, 178 cases (18.25%) of grade II and 68(6.97%) cases of grade Ill tumours. Conclusion: This study shows that in Pakistani females, the most commonly encountered lesion in carcinoma of the breast followed by the benign lesions such as fibro adenoma, fibrocystic disease & others. Breast carcinoma occurs at a younger age group with predominance of high-grade lesions and with frequent lymph node metastasis