Evaluation of boolean formulas with restricted inputs

Thesis (S.B.)--Massachusetts Institute of Technology, Dept. of Physics, 2010.Cataloged from PDF version of thesis.Includes bibliographical references (p. 61).In this thesis, I will investigate the running time of quantum algorithms for evaluating boolean functions when the input is promised to satisfy certain conditions. The two quantum algorithms considered in this paper are the quantum walk algorithm for NAND trees given by Farhi and Gutmann [2], and an algorithm for more general boolean formulas based on span programs, given by Reichardt and Spalek [6]. I will show that these algorithms can run much faster on a certain set of inputs, and that there is a super-polynomial separation between the quantum algorithm and the classical lower bound on this problem. I will apply this analysis to quantum walks on decision trees, as described in [3], giving a class of decision trees that can be penetrated quickly by quantum walk but may not be efficiently searchable by classical algorithms.by Bohua Zhan.S.B

A Generalized Hybrid Hoare Logic

Deductive verification of hybrid systems (HSs) increasingly attracts more attention in recent years because of its power and scalability, where a powerful specification logic for HSs is the cornerstone. Often, HSs are naturally modelled by concurrent processes that communicate with each other. However, existing specification logics cannot easily handle such models. In this paper, we present a specification logic and proof system for Hybrid Communicating Sequential Processes (HCSP), that extends CSP with ordinary differential equations (ODE) and interrupts to model interactions between continuous and discrete evolution. Because it includes a rich set of algebraic operators, complicated hybrid systems can be easily modelled in an algebra-like compositional way in HCSP. Our logic can be seen as a generalization and simplification of existing hybrid Hoare logics (HHL) based on duration calculus (DC), as well as a conservative extension of existing Hoare logics for concurrent programs. Its assertion logic is the first-order theory of differential equations (FOD), together with assertions about traces recording communications, readiness, and continuous evolution. We prove continuous relative completeness of the logic w.r.t. FOD, as well as discrete relative completeness in the sense that continuous behaviour can be arbitrarily approximated by discretization. Besides, we discuss how to simplify proofs using the logic by providing a simplified assertion language and a set of sound and complete rules for differential invariants for ODEs. Finally, we implement a proof assistant for the logic in Isabelle/HOL, and apply it to verify two case studies to illustrate the power and scalability of our logic

Virulence of H5N1 virus in mice attenuates after in vitro serial passages

The virulence of A/Vietnam/1194/2004 (VN1194) in mice attenuated after serial passages in MDCK cells and chicken embryos, because the enriched large-plaque variants of the virus had significantly reduced virulence. In contrast, the small-plaque variants of the virus and the variants isolated from the brain of mice that were infected with the parental virus VN1194 had much higher virulence in mice. The virulence attenuation of serially propagated virus may be caused by the reduced neurotropism in mice. Our whole genome sequence analysis revealed substitutions of a total of two amino acids in PB1, three in PB2, two in PA common for virulence attenuated variants, all or part of which may be correlated with the virulence attenuation and reduced neurotropism of the serially propagated VN1194 in mice. Our study indicates that serial passages of VN1194 in vitro lead to adaptation and selection of variants that have markedly decreased virulence and neurotropism, which emphasizes the importance of direct analysis of original or less propagated virus samples

OmniForce: On Human-Centered, Large Model Empowered and Cloud-Edge Collaborative AutoML System

Automated machine learning (AutoML) seeks to build ML models with minimal human effort. While considerable research has been conducted in the area of AutoML in general, aiming to take humans out of the loop when building artificial intelligence (AI) applications, scant literature has focused on how AutoML works well in open-environment scenarios such as the process of training and updating large models, industrial supply chains or the industrial metaverse, where people often face open-loop problems during the search process: they must continuously collect data, update data and models, satisfy the requirements of the development and deployment environment, support massive devices, modify evaluation metrics, etc. Addressing the open-environment issue with pure data-driven approaches requires considerable data, computing resources, and effort from dedicated data engineers, making current AutoML systems and platforms inefficient and computationally intractable. Human-computer interaction is a practical and feasible way to tackle the problem of open-environment AI. In this paper, we introduce OmniForce, a human-centered AutoML (HAML) system that yields both human-assisted ML and ML-assisted human techniques, to put an AutoML system into practice and build adaptive AI in open-environment scenarios. Specifically, we present OmniForce in terms of ML version management; pipeline-driven development and deployment collaborations; a flexible search strategy framework; and widely provisioned and crowdsourced application algorithms, including large models. Furthermore, the (large) models constructed by OmniForce can be automatically turned into remote services in a few minutes; this process is dubbed model as a service (MaaS). Experimental results obtained in multiple search spaces and real-world use cases demonstrate the efficacy and efficiency of OmniForce

H5N1 avian influenza re-emergence of Lake Qinghai: phylogenetic and antigenic analyses of the newly isolated viruses and roles of migratory birds in virus circulation

Highly pathogenic avian influenza H5N1 virus has swept west across the globe and caused serious debates on the roles of migratory birds in virus circulation since the first large-scale outbreak in migratory birds of Lake Qinghai, 2005. In May 2006, another outbreak struck Lake Qinghai and six novel strains were isolated. To elucidate these QH06 viruses, the six isolates were subjected to whole-genome sequencing. Phylogenetic analyses show that QH06 viruses are derived from the lineages of Lake Qinghai, 2005. Five of the six novel isolates are adjacent to the strain A/Cygnus olor/Croatia/1/05, and the last one is related to the strain A/duck/Novosibirsk/02/05, an isolate of the flyway. Antigenic analyses suggest that QH06 and QH05 viruses are similar to each other. These findings implicate that QH06 viruses of Lake Qinghai may travel back via migratory birds, though not ruling out the possibility of local circulation of viruses of Lake Qinghai

User Interface Design in the HolPy Theorem Prover (Invited Talk)

HolPy is a new interactive theorem prover implemented in Python. It is designed to achieve a small trusted-code-base with externally checkable proofs, writing proof automation using a Python API, and permit a wide variety of user interfaces for different application scenarios. In this talk, I will focus on the design of user interfaces in HolPy. While most interactive theorem provers today use text-based user interfaces, there have been several existing work aiming to build point-and-click interfaces where the user perform actions by clicking on part of the goal or choosing from a menu. In our work, we incorporate into the design extensive proof automation and heuristic suggestion mechanisms, allowing construction of proofs on a large scale using this method. We demonstrate the approach in two common scenarios: general-purpose theorem proving and symbolic computation in mathematics

Combinatorial Methods in Bordered Heegaard Floer Homology

In this thesis we give several combinatorial constructions and proofs in bordered Heegaard Floer homology. In the first part, we give an explicit description of a rank-1 model of CFAA(I), the type AA invariant associated to the identity diffeomorphism. This leads to a combinatorial proof of the quasi-invertibility of CFDD(I). In the second part, we use the newly constructed CFAA(I) to describe the type DA invariant CFDA(\tau) for any arcslide \tau. Using this, we give a combinatorial construction of HF(Y) for any 3-manifold Y, and prove that it is a 3-manifold invariant. Along the way, we prove combinatorially that bordered Floer theory gives a linear-categorical representation of the (strongly-based) mapping class groupoid. In the third part, we develop the theory of local type DA bimodules and extension by identity, and use it to give another construction of CFDA(\tau) for arcslides, which leads to a faster algorithm to compute HF for an arbitrary 3-manifold

Mechanizing the CMP Abstraction for Parameterized Verification

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