A Novel Robust Mel-Energy Based Voice Activity Detector for Nonstationary Noise and Its Application for Speech Waveform Compression

The voice activity detection (VAD) is crucial in all kinds of speech applications. However, almost all existing VAD algorithms suffer from the nonstationarity of both speech and noise. To combat this difficulty, we propose a new voice activity detector, which is based on the Mel-energy features and an adaptive threshold related to the signal-to-noise ratio (SNR) estimates. In this thesis, we first justify the robustness of the Bayes classifier using the Mel-energy features over that using the Fourier spectral features in various noise environments. Then, we design an algorithm using the dynamic Mel-energy estimator and the adaptive threshold which depends on the SNR estimates. In addition, a realignment scheme is incorporated to correct the sparse-and-spurious noise estimates. Numerous simulations are carried out to evaluate the performance of our proposed VAD method and the comparisons are made with a couple existing representative schemes, namely the VAD using the likelihood ratio test with Fourier spectral energy features and that based on the enhanced time-frequency parameters. Three types of noise, namely white noise (stationary), babble noise (nonstationary) and vehicular noise (nonstationary) were artificially added by the computer for our experiments. As a result, our proposed VAD algorithm significantly outperforms other existing methods as illustrated by the corresponding receiver operating curves (ROCs). Finally, we demonstrate one of the major applications, namely speech waveform compression, associated with our new robust VAD scheme and quantify the effectiveness in terms of compression efficiency

The Hiring Entity’s Usual Course of Business

The ABC test has increasingly become a tool to differentiate employees from independent contractors. Companies and counsel throughout the nation have grappled with Part B of this test, which requires a determination of the hiring entity’s “usual course of business.” Adjudicators have provided little guidance on how to conduct this analysis and are admittedly frustrated with this “elusive concept.” Yet a thorough treatment of the analytical framework and guiding principles of Part B of the ABC Test has not been put forth. This article fills this void in scholarship. By tracing the relevant concepts to the common law control test, and more importantly, a lesserknown framework analyzing skill and integration to determine liability, in addition to articulating the genesis and proliferation of the ABC Test within unemployment insurance legislation, this article answers a call from the judiciary to locate the origins of the ABC Test. Assessing decisions from state supreme courts and intermediate appellate bodies, this article then examines three methods courts use to determine whether work was done outside the usual course of the hiring entity’s business. The principal insight of this article is that work which is in the hiring entity’s usual course of business is work which provides regular aid to the business. This article concludes by analyzing two related questions within the Part B framework: (1) whether the Part B test is work-specific or worker-specific, a question of salience given the use of class actions, and (2) how to describe the hiring entity’s business, a question of import due to the rise of the gig economy

Two Level Disambiguation Model for Query Translation

Selection of the most suitable translation among all translation candidates returned by bilingual dictionary has always been quiet challenging task for any cross language query translation. Researchers have frequently tried to use word co-occurrence statistics to determine the most probable translation for user query. Algorithms using such statistics have certain shortcomings, which are focused in this paper. We propose a novel method for ambiguity resolution, named ‘two level disambiguation model’. At first level disambiguation, the model properly weighs the importance of translation alternatives of query terms obtained from the dictionary. The importance factor measures the probability of a translation candidate of being selected as the final translation of a query term. This removes the problem of taking binary decision for translation candidates. At second level disambiguation, the model targets the user query as a single concept and deduces the translation of all query terms simultaneously, taking into account the weights of translation alternatives also. This is contrary to previous researches which select translation for each word in source language query independently. The experimental result with English-Hindi cross language information retrieval shows that the proposed two level disambiguation model achieved 79.53% and 83.50% of monolingual translation and 21.11% and 17.36% improvement compared to greedy disambiguation strategies in terms of MAP for short and long queries respectively

Traveling-wave Thomson scattering for electron-beam spectroscopy

We propose a method to use traveling-wave Thomson scattering for spatiotemporally-resolved electron spectroscopy. This can enable ultrafast time-resolved measurements of the dynamics of relativistic electrons in the presence of extremely intense light fields, either in vacuum or in plasma, such as in laser wakefield accelerators. We demonstrate, with test-particle simulation and analysis, the capability of this technique for measurements of various high field phenomena: radiation reaction of electrons due to scattering, dephasing of a laser wakefield accelerator, and acceleration of electrons in multiple buckets by a laser wakefield. We propose a method to use traveling-wave Thomson scattering for spatiotemporally-resolved electron spectroscopy. This can enable ultrafast time-resolved measurements of the dynamics of relativistic electrons in the presence of extremely intense light fields, either in vacuum or in plasma, such as in laser wakefield accelerators. We demonstrate, with test-particle simulation and analysis, the capability of this technique for measurements of various high field phenomena: radiation reaction of electrons due to scattering, dephasing of a laser wakefield accelerator, and acceleration of electrons in multiple buckets by a laser wakefield

Search for magnetoelectric monopole response in Cr2_2O3_3 powder

Powder samples have been suggested as a pathway to fabricate isotropic magnetoelectric (ME) materials which effectively only have a pseudoscalar or monopole ME response. We demonstrate that random distribution of ME grains alone does not warrant isotropic ME response because the activation of a non-vanishing ME response requires a ME field cooling protocol which tends to induce preferred axes. We investigate the evolution of ME susceptibility in powder chromia samples for various ME field cooling protocols both theoretically and experimentally. In particular, we work out the theoretical expressions for ME susceptibility for powder Chromia in the framework of statistical mechanics where Boltzmann factors weigh the orientation of the N\'eel vector relative to the local orientation of the c-axis of a grain. Previous approximations oversimplified the thermodynamic nature of the annealing process giving rise to misleading conclusions on the role of the magnitude of the applied product of electric and magnetic fields on the ME response. In accordance with our refined theory, a strong dependence of the functional form of $\alpha$ vs. $T$ of Chromia powders on the ME field cooling protocol is observed. It shows that Chromia powder is not generically an isotropic ME effective medium but provides a pathway to realize the elusive isotropic ME response.Comment: Submitted to Physical Review

On the metric dimension of rotationally-symmetric convex polytopes

Metric dimension is a~generalization of affine dimension to arbitrary metric spaces (provided a resolving set exists). Let $\mathcal{F}$ be a family of connected graphs $G_{n}$ : $\mathcal{F} = (G_{n})_{n}\geq 1$ depending on $n$ as follows: the order $|V(G)| = \varphi(n)$ and $\lim\limits_{n\rightarrow \infty}\varphi(n)=\infty$. If there exists a constant C > 0 such that $dim(G_{n}) \leq C$ for every $n \geq 1$ then we shall say that $\mathcal{F}$ has bounded metric dimension, otherwise $\mathcal{F}$ has unbounded metric dimension. If all graphs in $\mathcal{F}$ have the same metric dimension, then $\mathcal{F}$ is called a family of graphs with constant metric dimension.\\ In this paper, we study the metric dimension of some classes of convex polytopes which are rotationally-symmetric. It is shown that these classes of convex polytoes have the constant metric dimension and only three vertices chosen appropriately suffice to resolve all the vertices of these classes of convex polytopes. It is natural to ask for the characterization of classes of convex polytopes with constant metric dimension

Pancreatic cysts suspected to be branch duct intraductal papillary mucinous neoplasm without concerning features have low risk for development of pancreatic cancer.

BackgroundThe risk of developing pancreatic cancer is uncertain in patients with clinically suspected branch duct intraductal papillary mucinous neoplasm (BD-IPMN) based on the "high-risk stigmata" or "worrisome features" criteria proposed in the 2012 international consensus guidelines ("Fukuoka criteria").MethodsRetrospective case series involving patients referred for endoscopic ultrasound (EUS) of indeterminate pancreatic cysts with clinical and EUS features consistent with BD-IPMN. Rates of pancreatic cancer occurring at any location in the pancreas were compared between groups of patients with one or more Fukuoka criteria ("Highest-Risk Group", HRG) and those without these criteria ("Lowest-Risk Group", LRG).ResultsAfter exclusions, 661 patients comprised the final cohort (250 HRG and 411 LRG patients), 62% female with an average age of 67 years and 4 years of follow up. Pancreatic cancer, primarily adenocarcinoma, occurred in 60 patients (59 HRG, 1 LRG). Prevalent cancers diagnosed during EUS, immediate surgery, or first year of follow up were found in 48/661 (7.3%) of cohort and exclusively in HRG (33/77, 42.3%). Using Kaplan-Meier method, the cumulative incidence of cancer at 7 years was 28% in HRG and 1.2% in LRG patients (P<0.001).ConclusionsThis study supports using Fukuoka criteria to stratify the immediate and long-term risks of pancreatic cancer in presumptive BD-IPMN. The risk of pancreatic cancer was highest during the first year and occurred exclusively in those with "high-risk stigmata" or "worrisome features" criteria. After the first year all BD-IPMN continued to have a low but persistent cancer risk

SHORT TERM OUTCOME OF PATIENTS WITH HEPATOPANCREATOBILIARY MALIGNANCIES TREATED IN A MULTIDISCIPLINARY HEPATOBILIARY UNIT IN A TERTIARY REFERRAL CENTER

Purpose: Specialisation in hepatopancreatobiliary (HPB) surgery has evolved over the past few decades based on better understanding of the biology and the behaviour of the diseases. In this review from a specialised HPB service, we aim to provide an overview of the HPB oncological cases managed in a tertiary care cancer hospital. Methods: All cases of HPB malignancies treated in our hospital between October 2014 and September 2015 were included in the study. Clinical findings, operative details and short-term post-operative outcomes were assessed from a prospectively managed database. Results: A total of 65 oncological procedures were performed over 1 year. These included 23 hepatic resections, 27 pancreaticoduodenectomies, 5 radical surgeries for gallbladder cancer, 2 distal pancreatectomy and 8 nephrectomies with exploration of the inferior vena cava. One patient successfully underwent Associated Liver Partition with Portal vein ligation and staged hepatectomy (ALPPS Procedure), which to our knowledge was the rst ALPPS procedure carried out in Pakistan. Conclusion: The short-term experience of patients managed in specialised HPB unit has shown good outcomes.There is a need for establishing HPB units in most tertiary care hospitals in the country. Key words: Associated liver partition with portal vein ligation and staged hepatectomy procedure, hepatic resections, hepatopancreatobiliary surgery, pancreaticoduodenectomy

Digital Forensic Examination of Mobile phone Data

Mobile phones are an integral part of our lives since they have played a vital role in bringing people closer together. They have abundantly been used by people all across the globe as they keep them up-to-date about the happenings in the world. However, these mobile phones have also been used in carrying out various criminal activities for the past few decades, therefore, a new discipline of Mobile Phone Forensics has been introduced which will help a lot in curbing the menace of these crimes by locating the whereabouts of the criminals. This research paper deals with the introduction of this innovative discipline of mobile phone forensics by throwing light on the importance of this discipline. It also deals with the detailed procedure of conducting a formal forensics analysis with the help of these mobile phones

New Roles for Old Glue: Astrocyte Function in Synaptic Plasticity and Neurological Disorders

Previously believed to solely play a supportive role in the central nervous system, astrocytes are now considered active players in normal brain function. Evidence in recent decades extends their contributions beyond the classically held brain glue role; it’s now known that astrocytes act as a unique excitable component with functions extending into local network modulation, synaptic plasticity, and memory formation, and postinjury repair. In this review article, we highlight our growing understanding of astrocyte function and physiology, the increasing role of gliotransmitters in neuron-glia communication, and the role of astrocytes in modulating synaptic plasticity and cognitive function. Owing to the duality of both beneficial and deleterious roles attributed to astrocytes, we also discuss the implications of this new knowledge as it applies to neurological disorders including Alzheimer disease, epilepsy, and schizophrenia