Statistical static timing analysis considering process variations and crosstalk

Increasing relative semiconductor process variations are making the prediction of realistic worst-case integrated circuit delay or sign-off yield more difficult. As process geometries shrink, intra-die variations have become dominant and it is imperative to model them to obtain accurate timing analysis results. In addition, intra-die process variations are spatially correlated due to pattern dependencies in the manufacturing process. Any statistical static timing analysis (SSTA) tool is incomplete without a model for signal crosstalk, as critical path delays can increase or decrease depending on the switching of capacitively coupled nets. The coupled signal timing in turn depends on the process variations. This work describes an SSTA tool that models signal crosstalk and spatial correlation in intra-die process variations, along with gradients and inter-die variations

Accelerated Neural Network Training with Rooted Logistic Objectives

Many neural networks deployed in the real world scenarios are trained using cross entropy based loss functions. From the optimization perspective, it is known that the behavior of first order methods such as gradient descent crucially depend on the separability of datasets. In fact, even in the most simplest case of binary classification, the rate of convergence depends on two factors: (1) condition number of data matrix, and (2) separability of the dataset. With no further pre-processing techniques such as over-parametrization, data augmentation etc., separability is an intrinsic quantity of the data distribution under consideration. We focus on the landscape design of the logistic function and derive a novel sequence of {\em strictly} convex functions that are at least as strict as logistic loss. The minimizers of these functions coincide with those of the minimum norm solution wherever possible. The strict convexity of the derived function can be extended to finetune state-of-the-art models and applications. In empirical experimental analysis, we apply our proposed rooted logistic objective to multiple deep models, e.g., fully-connected neural networks and transformers, on various of classification benchmarks. Our results illustrate that training with rooted loss function is converged faster and gains performance improvements. Furthermore, we illustrate applications of our novel rooted loss function in generative modeling based downstream applications, such as finetuning StyleGAN model with the rooted loss. The code implementing our losses and models can be found here for open source software development purposes: https://anonymous.4open.science/r/rooted_loss

A comprehensive survey of the analytical, numerical and experimental methodologies for dynamics of multibody mechanical systems with clearance or imperfect joints

"Available online 19 December 2017"A comprehensive survey of the literature of the most relevant analytical, numerical, and experimental approaches for the kinematic and dynamic analyses of multibody mechanical systems with clearance joints is presented in this review. Both dry and lubricated clearance joints are addressed here, and an effort is made to include a large number of research works in this particular field, which have been published since the 1960′s. First, the most frequently utilized methods for modeling planar and spatial multibody mechanical systems with clearance joints are analyzed, and compared. Other important phenomena commonly associated with clearance joint models, such as wear, non-smooth behavior, optimization and control, chaos, and uncertainty and links’ flexibility, are then discussed. The main assumptions procedures and conclusions for the different methodologies are also examined and compared. Finally, future developments and new applications of clearance joint modeling and analysis are highlighted.This research was supported in part by the China 111 Project (B16003) and the National Natural Science Foundation of China under Grants 11290151, 11472042 and 11221202. The work was also supported by the Portuguese Foundation for Science and Technology with the reference project UID/EEA/04436/2013, by FEDER funds through the COMPETE 2020 – Programa Operacional Competitividade e Internacionalização (POCI) with the reference project POCI-01-0145-FEDER-006941.info:eu-repo/semantics/publishedVersio

INTEGRATED WATER RESOURCE MANAGEMENT: Actors and Rules Negotiating Water Management in Indian Himalayas

World wide integrated water resource management (IWRM) has gained prominence as a community-based approach for poverty alleviation and environmental management. However, its practical application, its precise meaning and its implication for policy practice has come under increased scrutiny. The thesis makes a proposition that the best way to understand IWRM in practice was to examine the interactive nature of actors and rules influencing water resource management. This proposition is examined to a core water-related issue applicable in four socioeconomically and hydrologically distinct hamlets from two watersheds in India. The thesis draws on new institutionalism from social sciences to evolve an analytical framework that was empirically applied using diverse research methods to unravel the complex interaction. The information (qualitative and quantitative) collected was collapsed in the Bayesian Belief Network model to identify the actors and rules, understand their influence network, and to determine the probability of decisions influencing water management. The study reveals a notable trend on the role of actors and rules in the comparative watersheds. In Khairi-Ka-Kala watershed that was well connected and located in lower hills, statutory actors play a prominent role in providing boundary, position and authority rules for policy making and water allocation. In contrast, in the remote Rajana watershed it was the socially embedded actors. Interestingly, the households capabilities were influenced by socially embedded actors that enabled them to access water in both the watersheds. The differential capabilities enabled households to evolve diverse actions that were facilitated by diverse agents of institutional change. Absence of information and scope rules was a major constraining factor for actors towards making informed water related decisions. The study reveals the role of diverse actors and rules negotiating water at various levels in space and time in the watersheds. In this contested regime, the thesis calls for building better infrastructure facilities to facilitate communication among actors, to monitor and evaluate water resource programmes by sectoral actors, facilitate endowments of actors for managing water and to remain adaptive to the diverse roles of agents for institutional innovation. This provides an enabling institutional environment for actors to exercise and negotiate their differential rules to manage water. The thesis concludes by drawing implications for water management, institutional analysis and by identifying area for future research to understand water resources management

NON-TREE REDUCTION TO CALCULATE SECOND ORDER DELAY

The computation of second order delay for non-tree circuits has been necessitated by the thirst for accuracy in estimation of delay and also the increasing use of non-tree type circuits in modern chip design. The calculation of first order moments in tree type circuits is straightforward and can be repeated iteratively to obtain higher order moments. The objective is to develop a closed-formula to convert a non-tree circuit to tree circuit so that it will be easier to obtain second order delay. The reduction technique is based on moment matching. Partial results have been obtained and are described in the later sections. PSPICE simulations were carried out to validate the obtained results

Health Risk in Urbanizing Regions: Examining the Nexus of Infrastructure, Hygiene and Health in Tashkent Province, Uzbekistan

Worldwide, development agencies have increased their investments in water supply and sanitation as a “powerful preventive medicine„ to address infectious diseases. These interventions have focused on on-site technical interventions or social engineering approaches, emulating the result-based targets of the development goals. Against this backdrop, the study examines the following research question: What is the role of socio-cultural backgrounds, housing characteristics, and environmental hygiene practices in addressing water-transmitted diseases in the Tashkent province of Uzbekistan. In a country where public statistics and official maps are rarely accessible, and research is restrictive, the study carried out a household survey using open data kit (ODK) between July and October 2015 in Olmalik, an industrial district, and the Kibray urbanizing district in the province. The findings reveal that demographic factors, poor sanitation practices, housing characteristics, and social behaviors are key predictors of water-transmitted diseases in the two districts. In the industrial township, poor housing, larger household size, and poor excreta disposal habits increased the occurrence of diseases, while in urbanizing districts, higher household size, frequently eating out, and access to public taps significantly increased the occurrence of water-transmitted diseases. The study, which was carried out in a challenging institutional environment, highlights the need for Uzbekistan to focus their policies on environmental hygiene, demographic factors and social behavior as key interventions rather than merely on on-site drinking water and sanitation interventions