Preserving Randomness for Adaptive Algorithms

Suppose Est is a randomized estimation algorithm that uses n random bits and outputs values in R^d. We show how to execute Est on k adaptively chosen inputs using only n + O(k log(d + 1)) random bits instead of the trivial nk (at the cost of mild increases in the error and failure probability). Our algorithm combines a variant of the INW pseudorandom generator [Impagliazzo et al., 1994] with a new scheme for shifting and rounding the outputs of Est. We prove that modifying the outputs of Est is necessary in this setting, and furthermore, our algorithm\u27s randomness complexity is near-optimal in the case d {-1, 1} using O(n log n) * poly(1/theta) queries to F and O(n) random bits (independent of theta), improving previous work by Bshouty et al. [Bshouty et al., 2004]

On the Quantum Computational Complexity of the Ising Spin Glass Partition Function and of Knot Invariants

It is shown that the canonical problem of classical statistical thermodynamics, the computation of the partition function, is in the case of +/-J Ising spin glasses a particular instance of certain simple sums known as quadratically signed weight enumerators (QWGTs). On the other hand it is known that quantum computing is polynomially equivalent to classical probabilistic computing with an oracle for estimating QWGTs. This suggests a connection between the partition function estimation problem for spin glasses and quantum computation. This connection extends to knots and graph theory via the equivalence of the Kauffman polynomial and the partition function for the Potts model.Comment: 8 pages, incl. 2 figures. v2: Substantially rewritte

Climate change burden sharing: capacity, responsibility, and the distinctive wrong of noncompliance

This thesis provides an account of climate change burden sharing. I reject the view, known as integrationism, which holds that principles of burden sharing should be regulated solely by a general theory of distributive justice. I argue, positively, that two capacity-based principles ought to play the dominant role in burden sharing. The first, The Exemption, justifies subsistence emissions in a scarce carbon budget. I claim that the second, The Ability to Pay Principle (APP), is plausible in its own right and can also act as a proxy for historical responsibility for climate change, which I argue must be construed in terms of the overuse of the global emissions sink. I further develop a set of parameters of responsibility, which justify departures from the APP in special cases. The first two parameters allow us to move away from the APP in certain cases where it produces unfairness. l also add a harm avoidance constraint to these parameters, in order to guard against the possibility that they produce a shortfall in the net contribution to burden sharing. My final parameter holds developed states responsible for wrongful noncompliance. I claim that the noncompliance of these states with their obligations towards climate change burden sharing constitutes an additional and distinctly relational injustice. More specifically, I argue that it expresses a message of disrespect to particular agents in the present who are connected to those most vulnerable to climate impacts in a number of morally important ways

Side-Information For Steganography Design And Detection

Today, the most secure steganographic schemes for digital images embed secret messages while minimizing a distortion function that describes the local complexity of the content. Distortion functions are heuristically designed to predict the modeling error, or in other words, how difficult it would be to detect a single change to the original image in any given area. This dissertation investigates how both the design and detection of such content-adaptive schemes can be improved with the use of side-information. We distinguish two types of side-information, public and private: Public side-information is available to the sender and at least in part also to anybody else who can observe the communication. Content complexity is a typical example of public side-information. While it is commonly used for steganography, it can also be used for detection. In this work, we propose a modification to the rich-model style feature sets in both spatial and JPEG domain to inform such feature sets of the content complexity. Private side-information is available only to the sender. The previous use of private side-information in steganography was very successful but limited to steganography in JPEG images. Also, the constructions were based on heuristic with little theoretical foundations. This work tries to remedy this deficiency by introducing a scheme that generalizes the previous approach to an arbitrary domain. We also put forward a theoretical investigation of how to incorporate side-information based on a model of images. Third, we propose to use a novel type of side-information in the form of multiple exposures for JPEG steganography

Learning Practically Feasible Policies for Online 3D Bin Packing

We tackle the Online 3D Bin Packing Problem, a challenging yet practically useful variant of the classical Bin Packing Problem. In this problem, the items are delivered to the agent without informing the full sequence information. Agent must directly pack these items into the target bin stably without changing their arrival order, and no further adjustment is permitted. Online 3D-BPP can be naturally formulated as Markov Decision Process (MDP). We adopt deep reinforcement learning, in particular, the on-policy actor-critic framework, to solve this MDP with constrained action space. To learn a practically feasible packing policy, we propose three critical designs. First, we propose an online analysis of packing stability based on a novel stacking tree. It attains a high analysis accuracy while reducing the computational complexity from $O(N^2)$ to $O(N \log N)$, making it especially suited for RL training. Second, we propose a decoupled packing policy learning for different dimensions of placement which enables high-resolution spatial discretization and hence high packing precision. Third, we introduce a reward function that dictates the robot to place items in a far-to-near order and therefore simplifies the collision avoidance in movement planning of the robotic arm. Furthermore, we provide a comprehensive discussion on several key implemental issues. The extensive evaluation demonstrates that our learned policy outperforms the state-of-the-art methods significantly and is practically usable for real-world applications.Comment: Science China Information Science

The Path to Full Reparations: A Community-Driven Model of Education Reparations for Black Youth in Los Angeles County, Phase I (Early Learners)

The unresolved long-term effects of slavery and past and ongoing systemic racism directed toward Black Americans can be seen in the devaluing and aggressively racist treatment of Black students in Los Angeles County schools. Through qualitative interviews with Black education community members in Los Angeles County, this study collected Black education community members’ perspectives on the need for a multiphase education reparations system for Black youth, beginning with early learners (ages 0 to 8), and what components such a system should include. Participants overwhelmingly supported an education reparations system due to the over-policing and criminalization of Black students and the history of racist and unjust policies and inequitable education; participants suggested multiple components of a potential education reparations system that can be grouped as student supports, family supports, educational resources, and societal and policy reforms. The study concludes with a proposal for introducing an education reparations system in Los Angeles County led by Black community leaders and grounded in community outreach and ongoing organizing

Data compression techniques applied to high resolution high frame rate video technology

An investigation is presented of video data compression applied to microgravity space experiments using High Resolution High Frame Rate Video Technology (HHVT). An extensive survey of methods of video data compression, described in the open literature, was conducted. The survey examines compression methods employing digital computing. The results of the survey are presented. They include a description of each method and assessment of image degradation and video data parameters. An assessment is made of present and near term future technology for implementation of video data compression in high speed imaging system. Results of the assessment are discussed and summarized. The results of a study of a baseline HHVT video system, and approaches for implementation of video data compression, are presented. Case studies of three microgravity experiments are presented and specific compression techniques and implementations are recommended