Abstract

Around 40% of global energy produced is consumed by buildings. By using renewable energy resources we can alleviate the dependence on electrical grids. Recent trends focus on incentivizing consumers to reduce their demand consumption during peak hours for sustainable demand response. To minimize the loss, the distributor companies should target the right set of consumers and demand the right amount of electricity reductions.This paper proposes a novel bounded integer min-knapsack algorithm and shows that the algorithm, while allowing for multiple unit reduction, also optimizes the loss to the distributor company within a factor of two (multiplicative) and a problem dependent additive constant. Existing CMAB algorithms fail to work in this setting due to nonmonotonicity of reward function and time varying optimal sets. We propose a novel algorithm (TwinMinKPDR-CB) to learn these compliance probabilities efficiently. Twin-MinKPDR-CB works for non-monotone reward functions, bounded minknapsack constraints, and time-varying optimal sets. We find that Twin-MinKPDR-CB achieves sub-linear regret of O(log T) with T being the number of rounds demand response is run.

Abstract

Several optimization scenarios involve multiple agents that desire to protect the privacy of their preferences. There are distributed algorithms for constraint optimization that provide improved privacy protection through secure multiparty computation. However, it comes at the expense of high computational complexity and does not constitute a rigorous privacy guarantee for optimization outcomes, as the result of the computation itself may compromise agents’ preferences. In this work, we show how to achieve privacy, specifically differential privacy, through the randomization of the solving process. In particular, we present P-Gibbs, which adapts the SD-Gibbs algorithm to obtain differential privacy guarantees with much higher computational efficiency. Experiments on graph coloring and meeting scheduling show the algorithm’s privacy-performance trade-off for varying privacy budgets, and the SD-Gibbs algorithm.

Abstract

We introduce MeronymNet, a novel hierarchical approach for con- trollable, part-based generation of multi-category objects using a single unified model. We adopt a guided coarse-to-fine strategy involving semantically conditioned generation of bounding box layouts, pixel-level part layouts and ultimately, the object depic- tions themselves. We use Graph Convolutional Networks, Deep Recurrent Networks along with custom-designed Conditional Vari- ational Autoencoders to enable flexible, diverse and category-aware generation of 2-D objects in a controlled manner. The performance scores for generated objects reflect MeronymNet’s superior perfor- mance compared to multiple strong baselines and ablative variants.

Abstract

The current study aims to analyse VR measures in correspondence with 360° virtual affective experiences to understand the underlying spatio-temporal attention processes. We selected extreme pleasant and extreme unpleasant emotional videos from the Stanford affective database and displayed to participants on HMD VR. The participants’ task was to explore the video and report their affective experience using the Self- Assessment Manikin (SAM) scale. The exploration behaviour was analysed using head-tracking parameters, such as standard deviation of all the three head-rotation axes (yaw, pitch and roll), angular speed and region-wise analysis. We observed a positive correlation between standard deviation of yaw and valence, and angular speed and valence. The result suggests that affective experience not only increases the scope of attention spatially (wide scanning), it also motivates to seek more information that leads to more head-movement during exploration. In region- wise analysis, we observed front field-of-view was primarily explored, and rear field-of-view was least explored, showing natural responses similar to real environments. In addition, we used Beck Depression Inventory-II (BDI) to assess participants’ emotional state, specifically depression symptoms. The relation between virtual affective experience and 360° exploration be- haviour is discussed in light of the BDI categories. The study findings broaden the scope for VR affective research by enabling psychomotor assessment in more ecologically valid settings. Index Terms—Emotion, Depression, Affective State, 360° Ex- ploration, Head-Tracking

Abstract

Control systems operate industrial plants to accomplish stakeholder objectives like achieving production targets, complying with environmental ordinances, handling faults, etc. Such stakeholder objectives get realised by identifying and executing valid control actions on the plant’s control system. E.g., to achieve fault management a command is fired to place machines in a fault mode when the plant is under an error state. Arriving at such control actions is a non-trivial task demanding a detailed understanding of the plant’s structure and behaviour. Besides, it is also essential to verify the consequences of such control actions relative to other cross-cutting objectives and plant behaviour. E.g., to fulfil fault management objectives, the action to set machines in fault mode may affect production goals due to the machine unavailability. Hence, validation of control actions is vital before executing them using the actual plant’s control system. With digital twin technologies (DT), it is now possible to verify the implications of such control actions against a plant’s behaviour and objectives in a simulated environment without affecting the actual plant operations. DTs get developed autonomously as one-off solutions to simulate and validate plant control actions in the current state of practice, demanding high efforts and domain expertise. Our paper proposes a knowledge-driven approach enabling automation in DT development. The result of our approach is an auto-generated digital twin that pro-actively mimics the plant’s control system behaviour and helps with the validation of control actions before their execution. We use this approach to build three fault management DTs in a power plant. The application of our approach significantly reduces the manual efforts and development time to build such DTs.

Abstract

Handwritten documents are often characterized by dense and uneven layout. Despite advances, standard deep network based approaches for semantic layout segmentation are not robust to complex deformations seen across semantic regions. This phenomenon is especially pronounced for the low-resource Indic palm-leaf manuscript domain. To address the issue, we first introduce Indiscapes2, a new large-scale diverse dataset of Indic manuscripts with semantic layout annotations. Indiscapes2 contains documents from four different historical collections and is 150% larger than its predecessor, Indiscapes. We also propose a novel deep network Palmira for robust, deformation-aware instance segmentation of regions in handwritten manuscripts. We also report Hausdorff distance and its variants as a boundary-aware performance measure. Our experiments demonstrate that Palmira provides robust layouts, outperforms strong baseline approaches and ablative variants. We also include qualitative results on Arabic, South-East Asian and Hebrew historical manuscripts to showcase the generalization capability of Palmira. Keywords: instance segmentation · deformable convolutional network · historical document analysis · document image segmentation · datase

Abstract

We introduce MeronymNet, a novel hierarchical approach for controllable, part-based generation of multi-category objects using a single unified model. We adopt a guided coarse-to-fine strategy involving semantically conditioned generation of bounding box layouts, pixel-level part layouts and ultimately, the object depictions themselves. We use Graph Convolutional Networks, Deep Recurrent Networks along with custom-designed Conditional Variational Autoencoders to enable flexible, diverse and category-aware generation of 2-D objects in a controlled manner. The performance scores for generated objects reflect MeronymNet’s superior performance compared to multiple strong baselines and ablative variants.

Abstract

Control barrier function (CBF) constraints provide a rigorous characterization of the space of control inputs that ensure the satisfaction of state constraints, such as collision avoidance, at all time instants. However, CBFs are highly nonlinear and non-convex and thus, when incorporated within an optimization-based algorithm such as Model Predictive Control (MPC), leads to a computationally challenging problem. Existing works by-pass the computational intractability by collapsing the horizon of the MPC to a single step, although this comes at the cost of severe degradation of performance. In this paper, we present two contributions to ensure the real-time performance of CBFs based MPC over long horizons in the context of multi-robot collision avoidance. First, we propose a customized Project Gradient Descent Method that incurs minimal computational overhead over existing one-step approaches but leads to a substantial improvement in trajectory smoothness, time to reach the goal, etc. Our second contribution lies in applying the proposed MPC to both quadrotors and fixed-wing aerial aircrafts (FWA). In particular, we show that the formulation for the quadrotors can be readily extended to the latter by deriving additional CBFs for the curvature and forward velocity constraints. We validate our algorithm with an extensive simulation of up to 10 robots in challenging benchmark scenarios.

Abstract

This paper presents an ultra-low power CMOS voltage reference (CVR) which is free of amplifier and resistor. A current generator circuit is used to generate a supply independent current to bias the active load in the temperature compensation circuit. Drain-source voltage of two critical MOSFETs is made equal in the current generator circuit by using a feedback arrangement to ensure a high PSRR of -75dB for the reference voltage. Temperature compensation is achieved by using the complementary to absolute temperature (CTAT) nature of gatesource of a MOSFET operating in the subthreshold region and proportional to absolute temperature (PTAT) nature of conventional composite pair architecture. The proposed CVR is designed in TSMC 180nm technology. The circuit works desirably for a supply range of 0.85V to 2.3V while generating a reference voltage of around 0.68V. Maximum temperature coefficient (TC) of 184 ppm/˚C and minimum TC of 69 ppm/˚C are noted for mismatch and process variations in the Monte-Carlo simulation for 1000 samples. The circuit consumes only 46nW of power, which makes it suitable for ultra-low power applications. Keywords— CMOS voltage reference, Line sensitivity, Subthreshold region, Temperature compensation.

Abstract

In this paper, we study FPGA based pipelined and superscalar design of two variants of conjugate gradient methods for solving Laplacian equation on a discrete grid; the first version corresponds to the original conjugate gradient algorithm, and the second version corresponds to a slightly modified version of the same. In conjugate gradient method to solve partial differential equations, matrix vector operations are required in each iteration; these operations can be implemented as 5 point stencil operations on the grid without explicitely constructing the matrix. We show that a pipelined and superscalar design using high level synthesis written in C language leads to a significant reduction in latencies for both methods. When comparing these two, we show that the later has roughly two times lower latency than the former given the same degree of superscalarity. These reductions in latencies for the newer variant of CG is due to parallel implementations of stencil operation on subdomains of the grid, and dut to overlap of these stencil operations with dot product operations. In a superscalar design, domain needs to be partitioned, and boundary data needs to be copied, which requires padding. In 1D partition, the padding latency increases as the number of partitions increase. For a streaming data flow model, we propose a novel traversal of the grid for 2D domain decomposition that leads to 2 times reduction in latency cost involved with padding compared to 1D partitions. Our implementation is roughly 10 times faster than software implementation for linear system of dimension 10000 × 10000. Index Terms—FPGA, High Level Synthesis, Conjugate Gradient, Laplace System, Pipelining, Superscalarity.