Empirical studies of structural phenomena using a curated corpus of Java code

Contrary to 50 years\u27 worth of advice in the instructional literature on software design, long cyclic dependencies are found to be widespread in sizeable, curated corpus of real Java software. Among their causes may be overuse of static members, underuse of dependency injection and poor tool support for avoiding them.<br /

Genetic heterogeneity analysis using genetic algorithm and network science

Through genome-wide association studies (GWAS), disease susceptible genetic variables can be identified by comparing the genetic data of individuals with and without a specific disease. However, the discovery of these associations poses a significant challenge due to genetic heterogeneity and feature interactions. Genetic variables intertwined with these effects often exhibit lower effect-size, and thus can be difficult to be detected using machine learning feature selection methods. To address these challenges, this paper introduces a novel feature selection mechanism for GWAS, named Feature Co-selection Network (FCSNet). FCS-Net is designed to extract heterogeneous subsets of genetic variables from a network constructed from multiple independent feature selection runs based on a genetic algorithm (GA), an evolutionary learning algorithm. We employ a non-linear machine learning algorithm to detect feature interaction. We introduce the Community Risk Score (CRS), a synthetic feature designed to quantify the collective disease association of each variable subset. Our experiment showcases the effectiveness of the utilized GA-based feature selection method in identifying feature interactions through synthetic data analysis. Furthermore, we apply our novel approach to a case-control colorectal cancer GWAS dataset. The resulting synthetic features are then used to explain the genetic heterogeneity in an additional case-only GWAS dataset

Proceedings of 11th Symposium on Programming Languages and Software Tools and 7th Nordic Workshop on Model Driven Software Engineering

Robert C. Martin presented a software metric for a set of classes i.e. a package. The objective of the package level metric is to identify poorly designed packages. The Martin's metric actually consists of eight metrics which measure a few different characteristics of packages. The metric is widely known, but there is lack of theoretical and empirical evaluation of the Martin’s metric. This paper evaluates the theoretical background of the metric against an evaluation framework and presents an experimental evaluation of five open-source software applications. The theoretical validation reveals a weakness in Martin's definition for cohesion. We propose a modification which is valid according to the evaluation framework.  </div

SkipConvGAN: Monaural Speech Dereverberation using Generative Adversarial Networks via Complex Time-Frequency Masking

With the advancements in deep learning approaches, the performance of speech enhancing systems in the presence of background noise have shown significant improvements. However, improving the system's robustness against reverberation is still a work in progress, as reverberation tends to cause loss of formant structure due to smearing effects in time and frequency. A wide range of deep learning-based systems either enhance the magnitude response and reuse the distorted phase or enhance complex spectrogram using a complex time-frequency mask. Though these approaches have demonstrated satisfactory performance, they do not directly address the lost formant structure caused by reverberation. We believe that retrieving the formant structure can help improve the efficiency of existing systems. In this study, we propose SkipConvGAN - an extension of our prior work SkipConvNet. The proposed system's generator network tries to estimate an efficient complex time-frequency mask, while the discriminator network aids in driving the generator to restore the lost formant structure. We evaluate the performance of our proposed system on simulated and real recordings of reverberant speech from the single-channel task of the REVERB challenge corpus. The proposed system shows a consistent improvement across multiple room configurations over other deep learning-based generative adversarial frameworks.Comment: Published in: IEEE/ACM Transactions on Audio, Speech, and Language Processing ( Volume: 30

Design And Analysis Of A Fast Transient Voltage Regulator With All Ceramic Output Capacitors For Mobile Microprocessors

Keperluan untuk mereka bentuk pengatur voltan yang mempunyai tindak balas transien yang cepat didorong oleh kadar transien yang semakin meningkat daripada mikropemproses mudah alih. Oleh itu, mengoptimumkan frekuensi pensuisan pengatur voltan menjadi langkah penting untuk mencapai keseimbangan antara mengekalkan kecekapan pengatur voltan dan meningkatkan tindak balas transien. Kapasitor seramik berlapis telah menjadi lebih popular sebagai kapasitor output pengantara voltan disebabkan oleh saiznya yang kecil dan kos murah. Walaupun topologi penukar buck kekal tidak berubah betahun-tahun, terdapat banyak inovasi dan kejayaan cemerlang dalam peringkat kuasa pengatur voltan dan teknologi kawalan. Selain itu, reka bentuk yang berorientasikan galangan keluaran dan AVP (Penempatan Voltan Automatik) telah diperkenalkan untuk menangani keperluan transien. Banyak kajian juga memberi tumpuan untuk meningkatkan kecekapan pegantara voltage terutama untuk system yang beroperasi dengan bateri. Sebuah pengatur voltan bertindak balas laju yang mempunyai hanya kapasitor output seramik untuk mikropemproses mudah alih dicadangkan dalam kajian ini. Hasil kajian ini menunjukkan bahawa pengatur voltan yang direka adalah stabil dengan jenis dan bilangan kapasitor seramik berlapisan yang dicadangkan. Lebih penting lagi, keputusan transien juga adalah sehampir dengan keputusan simulasi di mana output pengantara voltan tidak mengalami kelanjakan dan kejatuhan voltan semasa dimuatkan dengan arus dinamik yang bermaknitud 10.5A dalam 1μs. Kesimpulannya, sebuah pengatur voltan dengan tindak balas laju yang mempunyai hanya kapasitor output seramik telah direka dan dianalisis and ia mempunyai tindak balas transien yang lebih baik berbanding dengan reka bentuk asal. Keperluan untuk mereka bentuk pengatur voltan yang mempunyai tindak balas transien yang cepat didorong oleh kadar transien yang semakin meningkat daripada mikropemproses mudah alih. Oleh itu, mengoptimumkan frekuensi pensuisan pengatur voltan menjadi langkah penting untuk mencapai keseimbangan antara mengekalkan kecekapan pengatur voltan dan meningkatkan tindak balas transien. Kapasitor seramik berlapis telah menjadi lebih popular sebagai kapasitor output pengantara voltan disebabkan oleh saiznya yang kecil dan kos murah. Walaupun topologi penukar buck kekal tidak berubah betahun-tahun, terdapat banyak inovasi dan kejayaan cemerlang dalam peringkat kuasa pengatur voltan dan teknologi kawalan. Selain itu, reka bentuk yang berorientasikan galangan keluaran dan AVP (Penempatan Voltan Automatik) telah diperkenalkan untuk menangani keperluan transien. Banyak kajian juga memberi tumpuan untuk meningkatkan kecekapan pegantara voltage terutama untuk system yang beroperasi dengan bateri. Sebuah pengatur voltan bertindak balas laju yang mempunyai hanya kapasitor output seramik untuk mikropemproses mudah alih dicadangkan dalam kajian ini. Hasil kajian ini menunjukkan bahawa pengatur voltan yang direka adalah stabil dengan jenis dan bilangan kapasitor seramik berlapisan yang dicadangkan. Lebih penting lagi, keputusan transien juga adalah sehampir dengan keputusan simulasi di mana output pengantara voltan tidak mengalami kelanjakan dan kejatuhan voltan semasa dimuatkan dengan arus dinamik yang bermaknitud 10.5A dalam 1μs. Kesimpulannya, sebuah pengatur voltan dengan tindak balas laju yang mempunyai hanya kapasitor output seramik telah direka dan dianalisis and ia mempunyai tindak balas transien yang lebih baik berbanding dengan reka bentuk asal. ________________________________________________________________________________________________________________________ The need to have fast transient response of the voltage regulator is driven by the increasing current slew rate of the mobile microprocessor. Hence, optimizing the switching frequency of the voltage regulator becomes an important step to achieve a balance between preserving the efficiency of the voltage regulator and improving the transient response. Besides, output capacitor solution with multilayer ceramic capacitor has also become more popular due to its small size and cheap cost. Over the years, even though the topology of the buck converter remains unchanged, there are plenty of innovations and breakthroughs in the power stage of the voltage regulator and controller technology. In addition, output impedance oriented design and adaptive voltage positioning (AVP) feature are also introduced to address the transient requirements. Apart from improving the dynamic response of the voltage regulator, many research works also focus on improving the efficiency of the voltage regulator, especially for battery-powered systems. A fast transient voltage regulator with all ceramic output capacitors for mobile microprocessor is proposed in this study. The outcome of the study shows that the voltage regulator designed is stable with the proposed type and number of multilayer ceramic capacitors. More importantly, the actual transient results correlate well with the simulation results where minimal transient droop and overshoot are observed with a dynamic current load step with a slew rate of 10.5A per 1 μs. In conclusion, a fast transient voltage regulator with all ceramic output capacitors is designed and analyzed which proven to have better transient performance compared to the original design on the test boar

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Siirretty Doriast

Practices in the Squale Quality Model (Squale Deliverable 1.3)

This document presents the Squale Software Quality Model as defined by Qualixo. It first reviews existing quality models and presents the Squale model with its particular- ity, namely a practice layer. Then it reviews in details an instance of this Squale Model with its Factors, Criteria and Practices, giving precise definitions and description1. Fi- nally, it discusses possible future enhancements of this model like new practices or its agreement with the program life-cycle and the change of needs during this life cycle

Iterative Machine Learning of a Cis-Regulatory Grammar

Gene regulation allows for the quantitative control of gene expression. Gene regulation is a complex process encoded through cis-regulatory sequences, short DNA sequences containing clusters of transcription factor binding sites. Each binding site can occur millions of times in multicellular genomes, and seemingly similar collections of binding sites can have very different activities. A leading model to explain these degeneracies is that cis-regulatory sequences follow a “grammar” defined by the number, identity, strength, arrangement, and/or context of the underlying binding sites. Understanding cis-regulatory grammar requires high-throughput technology, quantitative measurements, and computational modeling. This thesis describes an iterative machine learning approach to study cis-regulatory grammar using mouse photoreceptors as a model system. First, I characterized sequence features associated with enhancer and silencer activity in sequences bound by the transcription factor CRX. I showed that both enhancers and silencers are highly occupied by CRX compared to inactive sequences, and enhancers are uniquely enriched for a diverse but degenerate collection of eight motifs. I demonstrated that this information captures a majority of the available signal in genomic sequences and developed an information content metric that summarizes the effects of motif number and diversity. Second, I developed an active machine learning framework that iteratively samples informative perturbations to address the limitations of training quantitative models on genomic sequences alone. I showed that this approach, when complemented with human decision-making, effectively guides machine learning models towards a biologically relevant representation of cis-regulatory grammar. I also highlighted how perturbations selected with active learning are more informative than other perturbations generated by the same procedure. The final machine learning model can capture global and local context-dependencies of transcription factor binding motifs. Using this model, I found that the same motifs can produce the same activity in multiple arrangements. Thus, active machine learning is an effective way to sample perturbations that improve quantitative models of cis-regulatory grammar. Collectively, these results provide an iterative framework to design and sample perturbations that reveal the complexities of cis-regulatory grammar underlying gene regulation

Characterisation of the cascode gate drive of power MOSFETs in clamped inductive switching applications

This thesis proposes a novel gate drive circuit to improve the switching performance of MOSFET power switches in power electronic converters. The proposed topology exploits the cascode configuration, allowing the minimisation of switching losses in the presence of practical circuit constraints, which enables efficiency and power density improvements. Switching characteristics of the new topology are investigated and key mechanisms that control the switching process are identified. Unique analysis tools and techniques are also developed to demonstrate the application of the cascode gate drive circuit for switching performance optimisation