Why Gabor Frames? Two Fundamental Measures of Coherence and Their Role in Model Selection

Bajwa, Waheed U.,Calderbank, Robert,Jafarpour, Sina The Korea Institute of Information and Commucation 2010 Journal of communications and networks Vol.12 No.4

The problem of model selection arises in a number of contexts, such as subset selection in linear regression, estimation of structures in graphical models, and signal denoising. This paper studies non-asymptotic model selection for the general case of arbitrary (random or deterministic) design matrices and arbitrary nonzero entries of the signal. In this regard, it generalizes the notion of incoherence in the existing literature on model selection and introduces two fundamental measures of coherence-termed as the worst-case coherence and the average coherence-among the columns of a design matrix. It utilizes these two measures of coherence to provide an in-depth analysis of a simple, model-order agnostic one-step thresholding (OST) algorithm for model selection and proves that OST is feasible for exact as well as partial model selection as long as the design matrix obeys an easily verifiable property, which is termed as the coherence property. One of the key insights offered by the ensuing analysis in this regard is that OST can successfully carry out model selection even when methods based on convex optimization such as the lasso fail due to the rank deficiency of the submatrices of the design matrix. In addition, the paper establishes that if the design matrix has reasonably small worst-case and average coherence then OST performs near-optimally when either (i) the energy of any nonzero entry of the signal is close to the average signal energy per nonzero entry or (ii) the signal-to-noise ratio in the measurement system is not too high. Finally, two other key contributions of the paper are that (i) it provides bounds on the average coherence of Gaussian matrices and Gabor frames, and (ii) it extends the results on model selection using OST to low-complexity, model-order agnostic recovery of sparse signals with arbitrary nonzero entries. In particular, this part of the analysis in the paper implies that an Alltop Gabor frame together with OST can successfully carry out model selection and recovery of sparse signals irrespective of the phases of the nonzero entries even if the number of nonzero entries scales almost linearly with the number of rows of the Alltop Gabor frame.

Sequence Analysis of E2 Glycoprotein from Indian Isolate of Classical Swine Fever Virus (CSFV)

Bajwa, Mehak,Verma, Ramneek,Deka, Dipak,Dhol, Gagandeep Singh,Barman, Nagendra Nath The Korean Society for Microbiology and Biotechnol 2015 한국미생물·생명공학회지 Vol.43 No.1

CSF is a major concern for the swine industry, representing currently the most epizootically dangerous disease to the species. Numerous CSFV isolates with various degrees of virulence have already been isolated worldwide, ranging from low virulent strains that do not result in any apparent clinical signs to highly virulent strains that cause a severe per acute hemorrhagic fever with very high mortality. The molecular epidemiology of CSFVs has proven to be an essential tool for effective disease control and the development of safe and effective vaccines. Therefore, this study cloned and sequenced local CSFV isolates, and conducted a phylogenetic analysis based on the E2 glycoprotein encoding sequences.The RNA was extracted from PK15 cell culture passaged CSFV isolates, the cDNA prepared, and the complete E2 gene amplified with a product size of 1186 bp. The gelpurified PCR product was cloned into a pGEMT easy vector and the positive clone commercially sequenced. Aligning the nucleotide (1119 bp) and amino acid (373) sequences with 29 reference strains revealed nucleotide and amino acid sequence identities of 82.60-97.80% and 88.70-98.70%, respectively, indicating a higher mutation rate of the field CSFV strains. The phylogenetic analysis based on the complete E2 amino acid sequences also revealed a reliable differentiation of all the analyzed strains into specific genetic groups and subgroups, plus the local isolate (CSFV-E2) was found to cluster with the CSFV subgroup 2.2. Thus, the full-length E2 cds proved to be most suitable for a reliable and statistically significant phylogenetic analysis of CSFV isolates.

Sequence Analysis of E2 Glycoprotein from Indian Isolate of Classical Swine Fever Virus (CSFV)

( Mehak Bajwa ),( Ramneek Verma ),( Dipak Deka ),( Gagandeep Singh Dhol ),( Nagendra Nath Barman ) 한국미생물생명공학회(구 한국산업미생물학회) 2015 한국미생물·생명공학회지 Vol.43 No.1

CSF is a major concern for the swine industry, representing currently the most epizootically dangerous disease to the species. Numerous CSFV isolates with various degrees of virulence have already been isolated worldwide, ranging from low virulent strains that do not result in any apparent clinical signs to highly virulent strains that cause a severe per acute hemorrhagic fever with very high mortality. The molecular epidemiology of CSFVs has proven to be an essential tool for effective disease control and the development of safe and effective vaccines. Therefore, this study cloned and sequenced local CSFV isolates, and conducted a phylogenetic analysis based on the E2 glycoprotein encoding sequences.The RNA was extracted from PK15 cell culture passaged CSFV isolates, the cDNA prepared, and the complete E2 gene amplified with a product size of 1186 bp. The gelpurified PCR product was cloned into a pGEMT easy vector and the positive clone commercially sequenced. Aligning the nucleotide (1119 bp) and amino acid (373) sequences with 29 reference strains revealed nucleotide and amino acid sequence identities of 82.60-97.80% and 88.70-98.70%, respectively, indicating a higher mutation rate of the field CSFV strains. The phylogenetic analysis based on the complete E2 amino acid sequences also revealed a reliable differentiation of all the analyzed strains into specific genetic groups and subgroups, plus the local isolate (CSFV-E2) was found to cluster with the CSFV subgroup 2.2. Thus, the full-length E2 cds proved to be most suitable for a reliable and statistically significant phylogenetic analysis of CSFV isolates.

Awake Surgery for Lesional Epilepsy in Resource-Limited Settings: Case Report and Review of Literature

( Mohammad Hamza Bajwa ),( Syeda Amrah Hashmi ),( Abdullah Nisar ),( Muhammad Waqas Baqai ),( Saqib Kamran Bakhshi ),( Muskaan Abdul Qadir ),( Faraz Shafiq ),( Syed Ather Enam ) 대한뇌종양학회·대한신경종양학회·대한소아뇌종양학회 2023 Brain Tumor Research and Treatment Vol.11 No.4

Epilepsy surgery is a well-established treatment for drug-resistant epilepsy, with awake craniotomy being used in certain cases to remove epileptogenic foci while preserving crucial brain functions. We are presenting the first reported case from Pakistan of a 19-year-old woman who underwent awake epilepsy surgery to treat cortical dysplasia. She had a history of generalized tonic-clonic seizures since her childhood and was referred to our clinic due to an increase in seizure frequency. EEG and MRI identified the epileptogenic focus in the right parieto-temporal region. The patient underwent a neuro-navigation guided awake craniotomy and an excision of the epileptogenic focus in the right parieto-temporal region. The procedure was carried out using a scalp block and dexmedetomidine for conscious sedation, enabling the patient to remain awake throughout the surgery. Intraoperative mapping and electrocorticography were used for complex multidisciplinary care. Post-resection corticography showed no spikes along the resected margins. The patient was discharged without any complications and remained free of symptoms a year after the surgery. Awake epilepsy surgery is a viable option for removing epileptogenic foci while preserving vital cognitive functions. However, it is seldom used in low- and middle-income countries such as Pakistan. The successful outcome of this case underscores the need for greater awareness and availability of epilepsy surgery in resource-limited settings. Cost-effective measures, such as using small subdural strips for intraoperative localization, can be implemented.

Why Gabor Frames? Two Fundamental Measures of Coherence and Their Role in Model Selection (Invited Paper)

Waheed U. Bajwa,Robert Calderbank,Sina Jafarpour 한국통신학회 2010 Journal of communications and networks Vol.12 No.4

The problem of model selection arises in a number of contexts, such as subset selection in linear regression, estimation of structures in graphical models, and signal denoising. This paper studies non-asymptotic model selection for the general case of arbitrary (random or deterministic) design matrices and arbitrary nonzero entries of the signal. In this regard, it generalizes the notion of incoherence in the existing literature on model selection and introduces two fundamental measures of coherence—termed as the worst-case coherence and the average coherence—among the columns of a design matrix. It utilizes these two measures of coherence to provide an in-depth analysis of a simple, model-order agnostic one-step thresholding (OST) algorithm for model selection and proves that OST is feasible for exact as well as partial model selection as long as the design matrix obeys an easily verifiable property, which is termed as the coherence property. One of the key insights offered by the ensuing analysis in this regard is that OST can successfully carry out model selection even when methods based on convex optimization such as the lasso fail due to the rank deficiency of the submatrices of the design matrix. In addition, the paper establishes that if the design matrix has reasonably small worst-case and average coherence then OST performs near-optimally when either (i) the energy of any nonzero entry of the signal is close to the average signal energy per nonzero entry or (ii) the signal-to-noise ratio in the measurement system is not too high. Finally, two other key contributions of the paper are that (i)it provides bounds on the average coherence of Gaussian matrices and Gabor frames, and (ii) it extends the results on model selection using OST to low-complexity, model-order agnostic recovery of sparse signals with arbitrary nonzero entries. In particular, this part of the analysis in the paper implies that an AlltopGabor frame together with OST can successfully carry out model selection and recovery of sparse signals irrespective of the phases of the nonzero entries even if the number of nonzero entries scales almost linearly with the number of rows of the Alltop Gabor frame.

A Framework for Automated Object Oriented Analysis of Natural Language Software Specifications

Hina Afreen,Imran Sarwar Bajwa 보안공학연구지원센터 2012 International Journal of Software Engineering and Vol.6 No.2

IoT Enabled Intelligent System for Radiation Monitoring and Warning Approach using Machine Learning

Muhammad Saifullah,Imran Sarwar Bajwa,Muhammad Ibrahim,Mutyyba Asgher International Journal of Computer ScienceNetwork S 2023 International journal of computer science and netw Vol.23 No.5

Internet of things has revolutionaries every field of life due to the use of artificial intelligence within Machine Learning. It is successfully being used for the study of Radiation monitoring, prediction of Ultraviolet and Electromagnetic rays. However, there is no particular system available that can monitor and detect waves. Therefore, the present study designed in which IOT enables intelligence system based on machine learning was developed for the prediction of the radiation and their effects of human beings. Moreover, a sensor based system was installed in order to detect harmful radiation present in the environment and this system has the ability to alert the humans within the range of danger zone with a buzz, so that humans can move to a safer place. Along with this automatic sensor system; a self-created dataset was also created in which sensor values were recorded. Furthermore, in order to study the outcomes of the effect of these rays researchers used Support Vector Machine, Gaussian Naïve Bayes, Decision Trees, Extra Trees, Bagging Classifier, Random Forests, Logistic Regression and Adaptive Boosting Classifier were used. To sum up the whole discussion it is stated the results give high accuracy and prove that the proposed system is reliable and accurate for the detection and monitoring of waves. Furthermore, for the prediction of outcome, Adaptive Boosting Classifier has shown the best accuracy of 81.77% as compared with other classifiers.

(Zn/Co)-zeolitic imidazolate frameworks: Room temperature synthesis and application as promising U(VI) scavengers — A comparative study

Satvir Singh,B.S. Bajwa,Inderpreet Kaur 한국공업화학회 2021 Journal of Industrial and Engineering Chemistry Vol.93 No.-

Uranium prevalence in water beyond WHO limit (30 mg/l) may pose potential chemical and radiologicaltoxicity which can cause severe health problems associated with kidney, brain, liver, heart, etc. Therefore,regular monitoring of uranium content and development of efficient remediation strategies for itsremoval from water resources has gained immense attention at global level. In the present work, zeoliticimidazolate frameworks (ZIFs) based on zinc (ZIF-8), cobalt (ZIF-67) and bimetallic zinc & cobalt (Zn,Co-ZIF) using 2-methylimidazole as organic linker, were developed following a rapid room temperaturesynthesis, characterised for their surface and functional features using X-ray diffraction, SEM-EDX, BETand FT-IR followed by their application as adsorbents for uranium extraction. ZIFs were found to performbest at optimum adsorption parameters: pH (5.0), adsorbent dose (0.4 g/l) and contact time (120 min). The maximum Langmuir adsorption capacity (mg/g) of three ZIFs follows the order as: ZIF-8 (781.0) > Zn,Co-ZIF (564.7) > ZIF-67 (409.1). Thermodynamic parameters confirmed the spontaneous and endother-mic nature of adsorption process. Three ZIFs exhibit high adsorption efficiency and regeneration abilitywere explored for their practical application as packing material in the columns used in water purifiersand found to serve as competent adsorbents for treatment of uranium contaminated groundwatersamples.

Surgical Outcomes of Endoscopic Endonasal Versus Transcranial Resections of Adult Craniopharyngioma: A Meta-Analysis

Wardah Rafaqat,Mohammad Hamza Bajwa,Meher Angez,Syed Ather Enam 대한뇌종양학회 2022 Brain Tumor Research and Treatment Vol.10 No.4

Background : The endoscopic endonasal approach (EEA) has been gaining popularity for resection of adult craniopharyngiomas. However, the safety and effectiveness of the procedure in comparison to the traditional transcranial approach (TCA) remains unestablished as previous reviews are outdated. Methouds: A literature search without language restriction was conducted in PubMed, Cochrane database, and Web of Science from conception to July 9, 2021. Cohort studies and case series that compared EEA with TCA and assessed postoperative complications, recurrence, and 30-day mortality were included. Articles, where data for adult populations could not be extracted or calculated, were excluded. Article selection and data extraction in a predesigned data extraction form were conducted in duplicate. Pooled participant data were included in a random-effects model. Results: The search yielded 227 articles, from which eight cohort studies containing 11,395 patients were included (EEA: 6,614 patients, TCA: 4,781 patients). Six studies were good quality and two were fair quality according to the Newcastle Ottawa Scale. There were significantly higher rates of cerebrospinal fluid leak (risk ratio [RR]=0.23, 95% confidence interval [CI] 0.17–0.32, p<0.00001, I 2=0%) and lower rates of postoperative hypopituitarism (RR=1.40, 95% CI 1.30–1.51, p<0.00001, I 2=0%), hydrocephalus (RR=6.95, 95% CI 5.78–8.36, p<0.00001, I2=0%), visual impairment (RR=1.52, 95% CI 1.34–1.73, p<0.00001, I2=0%), and 30-day mortality (RR=5.63, 95% CI 3.87–8.19, p<0.00001, I 2=0%) after EEA. Non-significant lower rates of postoperative diabetes insipidus (RR=1.12, 95% CI 0.78–1.61, p=0.53, I2=85%) and recurrence of tumor (RR=2.69, 95% CI 0.35–20.81, p=0.34, I2=47%) were seen after EEA. Concliusion: EEA may be associated with reduced postoperative hypopituitarism, hydrocephalus, visual impairment, and 30-day mortality and higher rates of cerebrospinal fluid leak. These findings do not account for differences in tumor size and extension between the EEA and TCA cohorts. Further re- search on patients with comparable tumor characteristics is required to fully assess outcomes.

Formulation evaluation and optimization of fast disintegrating tablets of ketorolac tromethamine

Binu Raina,Abhimanyu Sharma,Prabhjot Singh Bajwa 한국약제학회 2018 Journal of Pharmaceutical Investigation Vol.48 No.6

In this study, we aimed to design fast disintegrating tablets (FDT) of ketorolac tromethamine (KT) to reduce gastric side effects of KT by physically associating it with phospholipon 80H (PL) by wet granulation. First preliminary batches were formulated to determine the effect of PL on tablet characteristics and to select best superdisintegrant among sodium starch glycolate and crospovidone. The effect of PL and maltodextrin (MD) concentrations on hardness, disintegration time and % drug release at 4 min was studied for the optimization of FDT. Optimization of FDT was done by employing 32 full factorial design using Design expert 10.1 software. The optimized batch of FDT showed disintegration time and percent release value of 37.33 ± 1.47 s and 42.74 ± 1.53% respectively. It was also found that 91.87% of drug was released within 10 min. Thus, by an appropriate combination of excipients, it was possible to formulate FDT capable of undergoing fast disintegration and having optimum hardness using simple and conventional techniques.