TY - CONF
AB - Fixed-point arithmetic is a popular alternative to floating-point arithmetic on embedded systems. Existing work on the verification of fixed-point programs relies on custom formalizations of fixed-point arithmetic, which makes it hard to compare the described techniques or reuse the implementations. In this paper, we address this issue by proposing and formalizing an SMT theory of fixed-point arithmetic. We present an intuitive yet comprehensive syntax of the fixed-point theory, and provide formal semantics for it based on rational arithmetic. We also describe two decision procedures for this theory: one based on the theory of bit-vectors and the other on the theory of reals. We implement the two decision procedures, and evaluate our implementations using existing mature SMT solvers on a benchmark suite we created. Finally, we perform a case study of using the theory we propose to verify properties of quantized neural networks.
AU - Baranowski, Marek
AU - He, Shaobo
AU - Lechner, Mathias
AU - Nguyen, Thanh Son
AU - Rakamarić, Zvonimir
ID - 8194
SN - 03029743
T2 - Automated Reasoning
TI - An SMT theory of fixed-point arithmetic
VL - 12166
ER -
TY - CONF
AB - This paper presents a foundation for refining concurrent programs with structured control flow. The verification problem is decomposed into subproblems that aid interactive program development, proof reuse, and automation. The formalization in this paper is the basis of a new design and implementation of the Civl verifier.
AU - Kragl, Bernhard
AU - Qadeer, Shaz
AU - Henzinger, Thomas A
ID - 8195
SN - 0302-9743
T2 - Computer Aided Verification
TI - Refinement for structured concurrent programs
VL - 12224
ER -
TY - JOUR
AB - This paper aims to obtain a strong convergence result for a Douglas–Rachford splitting method with inertial extrapolation step for finding a zero of the sum of two set-valued maximal monotone operators without any further assumption of uniform monotonicity on any of the involved maximal monotone operators. Furthermore, our proposed method is easy to implement and the inertial factor in our proposed method is a natural choice. Our method of proof is of independent interest. Finally, some numerical implementations are given to confirm the theoretical analysis.
AU - Shehu, Yekini
AU - Dong, Qiao-Li
AU - Liu, Lu-Lu
AU - Yao, Jen-Chih
ID - 8196
JF - Optimization and Engineering
SN - 1389-4420
TI - New strong convergence method for the sum of two maximal monotone operators
ER -
TY - GEN
AB - In this work, we investigate how the critical driving amplitude at the Floquet MBL-to-ergodic phase transition differs between smooth and non-smooth driving over a wide range of driving frequencies. To this end, we study numerically a disordered spin-1/2 chain which is periodically driven by a sine or a square-wave drive, respectively. In both cases, the critical driving amplitude increases monotonically with the frequency, and at large frequencies, it is identical for the two drives in the appropriate normalization. However, at low and intermediate frequencies the critical amplitude of the square-wave drive depends strongly on the frequency, while the one of the cosine drive is almost constant in a wide frequency range. By analyzing the density of drive-induced resonance in a Fourier space perspective, we conclude that this difference is due to resonances induced by the higher harmonics which are present (absent) in the Fourier spectrum of the square-wave (sine) drive. Furthermore, we suggest a numerically efficient method to estimate the frequency dependence of the critical driving amplitudes for different drives, based on measuring the density of drive-induced resonances.
AU - Diringer, Asaf A.
AU - Gulden, Tobias
ID - 8198
T2 - arXiv:2007.14879
TI - Robustness of the Floquet many-body localized phase in the presence of a smooth and a non-smooth drive
ER -
TY - JOUR
AB - Using inelastic cotunneling spectroscopy we observe a zero field splitting within the spin triplet manifold of Ge hut wire quantum dots. The states with spin ±1 in the confinement direction are energetically favored by up to 55 μeV compared to the spin 0 triplet state because of the strong spin–orbit coupling. The reported effect should be observable in a broad class of strongly confined hole quantum-dot systems and might need to be considered when operating hole spin qubits.
AU - Katsaros, Georgios
AU - Kukucka, Josip
AU - Vukušić, Lada
AU - Watzinger, Hannes
AU - Gao, Fei
AU - Wang, Ting
AU - Zhang, Jian-Jun
AU - Held, Karsten
ID - 8203
IS - 7
JF - Nano Letters
SN - 1530-6984
TI - Zero field splitting of heavy-hole states in quantum dots
VL - 20
ER -
TY - JOUR
AB - We consider the following setting: suppose that we are given a manifold M in Rd with positive reach. Moreover assume that we have an embedded simplical complex A without boundary, whose vertex set lies on the manifold, is sufficiently dense and such that all simplices in A have sufficient quality. We prove that if, locally, interiors of the projection of the simplices onto the tangent space do not intersect, then A is a triangulation of the manifold, that is, they are homeomorphic.
AU - Boissonnat, Jean-Daniel
AU - Dyer, Ramsay
AU - Ghosh, Arijit
AU - Lieutier, Andre
AU - Wintraecken, Mathijs
ID - 8248
JF - Discrete & Computational Geometry
SN - 0179-5376
TI - Local conditions for triangulating submanifolds of Euclidean space
ER -
TY - DATA
AB - Here are the research data underlying the publication "Estimating inbreeding and its effects in a long-term study of snapdragons (Antirrhinum majus)". Further information are summed up in the README document.
AU - Arathoon, Louise S
ID - 8254
TI - Estimating inbreeding and its effects in a long-term study of snapdragons (Antirrhinum majus)
ER -
TY - JOUR
AB - Modern scientific instruments produce vast amounts of data, which can overwhelm the processing ability of computer systems. Lossy compression of data is an intriguing solution, but comes with its own drawbacks, such as potential signal loss, and the need for careful optimization of the compression ratio. In this work, we focus on a setting where this problem is especially acute: compressive sensing frameworks for interferometry and medical imaging. We ask the following question: can the precision of the data representation be lowered for all inputs, with recovery guarantees and practical performance Our first contribution is a theoretical analysis of the normalized Iterative Hard Thresholding (IHT) algorithm when all input data, meaning both the measurement matrix and the observation vector are quantized aggressively. We present a variant of low precision normalized IHT that, under mild conditions, can still provide recovery guarantees. The second contribution is the application of our quantization framework to radio astronomy and magnetic resonance imaging. We show that lowering the precision of the data can significantly accelerate image recovery. We evaluate our approach on telescope data and samples of brain images using CPU and FPGA implementations achieving up to a 9x speedup with negligible loss of recovery quality.
AU - Gurel, Nezihe Merve
AU - Kara, Kaan
AU - Stojanov, Alen
AU - Smith, Tyler
AU - Lemmin, Thomas
AU - Alistarh, Dan-Adrian
AU - Puschel, Markus
AU - Zhang, Ce
ID - 8268
JF - IEEE Transactions on Signal Processing
SN - 1053587X
TI - Compressive sensing using iterative hard thresholding with low precision data representation: Theory and applications
ER -
TY - JOUR
AU - He, Peng
AU - Zhang, Yuzhou
AU - Xiao, Guanghui
ID - 8271
JF - Molecular Plant
SN - 16742052
TI - Origin of a subgenome and genome evolution of allotetraploid cotton species
ER -
TY - CONF
AB - We study turn-based stochastic zero-sum games with lexicographic preferences over reachability and safety objectives. Stochastic games are standard models in control, verification, and synthesis of stochastic reactive systems that exhibit both randomness as well as angelic and demonic non-determinism. Lexicographic order allows to consider multiple objectives with a strict preference order over the satisfaction of the objectives. To the best of our knowledge, stochastic games with lexicographic objectives have not been studied before. We establish determinacy of such games and present strategy and computational complexity results. For strategy complexity, we show that lexicographically optimal strategies exist that are deterministic and memory is only required to remember the already satisfied and violated objectives. For a constant number of objectives, we show that the relevant decision problem is in NP∩coNP , matching the current known bound for single objectives; and in general the decision problem is PSPACE -hard and can be solved in NEXPTIME∩coNEXPTIME . We present an algorithm that computes the lexicographically optimal strategies via a reduction to computation of optimal strategies in a sequence of single-objectives games. We have implemented our algorithm and report experimental results on various case studies.
AU - Chatterjee, Krishnendu
AU - Katoen, Joost P
AU - Weininger, Maximilian
AU - Winkler, Tobias
ID - 8272
SN - 03029743
T2 - International Conference on Computer Aided Verification
TI - Stochastic games with lexicographic reachability-safety objectives
VL - 12225
ER -
TY - JOUR
AB - Drought and salt stress are the main environmental cues affecting the survival, development, distribution, and yield of crops worldwide. MYB transcription factors play a crucial role in plants’ biological processes, but the function of pineapple MYB genes is still obscure. In this study, one of the pineapple MYB transcription factors, AcoMYB4, was isolated and characterized. The results showed that AcoMYB4 is localized in the cell nucleus, and its expression is induced by low temperature, drought, salt stress, and hormonal stimulation, especially by abscisic acid (ABA). Overexpression of AcoMYB4 in rice and Arabidopsis enhanced plant sensitivity to osmotic stress; it led to an increase in the number stomata on leaf surfaces and lower germination rate under salt and drought stress. Furthermore, in AcoMYB4 OE lines, the membrane oxidation index, free proline, and soluble sugar contents were decreased. In contrast, electrolyte leakage and malondialdehyde (MDA) content increased significantly due to membrane injury, indicating higher sensitivity to drought and salinity stresses. Besides the above, both the expression level and activities of several antioxidant enzymes were decreased, indicating lower antioxidant activity in AcoMYB4 transgenic plants. Moreover, under osmotic stress, overexpression of AcoMYB4 inhibited ABA biosynthesis through a decrease in the transcription of genes responsible for ABA synthesis (ABA1 and ABA2) and ABA signal transduction factor ABI5. These results suggest that AcoMYB4 negatively regulates osmotic stress by attenuating cellular ABA biosynthesis and signal transduction pathways.
AU - Chen, Huihuang
AU - Lai, Linyi
AU - Li, Lanxin
AU - Liu, Liping
AU - Jakada, Bello Hassan
AU - Huang, Youmei
AU - He, Qing
AU - Chai, Mengnan
AU - Niu, Xiaoping
AU - Qin, Yuan
ID - 8283
IS - 16
JF - International Journal of Molecular Sciences
SN - 16616596
TI - AcoMYB4, an Ananas comosus L. MYB transcription factor, functions in osmotic stress through negative regulation of ABA signaling
VL - 21
ER -
TY - JOUR
AB - We demonstrate the utility of optical cavity generated spin-squeezed states in free space atomic fountain clocks in ensembles of 390 000 87Rb atoms. Fluorescence imaging, correlated to an initial quantum nondemolition measurement, is used for population spectroscopy after the atoms are released from a confining lattice. For a free fall time of 4 milliseconds, we resolve a single-shot phase sensitivity of 814(61) microradians, which is 5.8(0.6) decibels (dB) below the quantum projection limit. We observe that this squeezing is preserved as the cloud expands to a roughly 200 μm radius and falls roughly 300 μm in free space. Ramsey spectroscopy with 240 000 atoms at a 3.6 ms Ramsey time results in a single-shot fractional frequency stability of 8.4(0.2)×10−12, 3.8(0.2) dB below the quantum projection limit. The sensitivity and stability are limited by the technical noise in the fluorescence detection protocol and the microwave system, respectively.
AU - Malia, Benjamin K.
AU - Martínez-Rincón, Julián
AU - Wu, Yunfan
AU - Hosten, Onur
AU - Kasevich, Mark A.
ID - 8285
IS - 4
JF - Physical Review Letters
SN - 00319007
TI - Free space Ramsey spectroscopy in rubidium with noise below the quantum projection limit
VL - 125
ER -
TY - CONF
AB - We consider the following dynamic load-balancing process: given an underlying graph G with n nodes, in each step t≥ 0, one unit of load is created, and placed at a randomly chosen graph node. In the same step, the chosen node picks a random neighbor, and the two nodes balance their loads by averaging them. We are interested in the expected gap between the minimum and maximum loads at nodes as the process progresses, and its dependence on n and on the graph structure. Variants of the above graphical balanced allocation process have been studied previously by Peres, Talwar, and Wieder [Peres et al., 2015], and by Sauerwald and Sun [Sauerwald and Sun, 2015]. These authors left as open the question of characterizing the gap in the case of cycle graphs in the dynamic case, where weights are created during the algorithm’s execution. For this case, the only known upper bound is of 𝒪(n log n), following from a majorization argument due to [Peres et al., 2015], which analyzes a related graphical allocation process. In this paper, we provide an upper bound of 𝒪 (√n log n) on the expected gap of the above process for cycles of length n. We introduce a new potential analysis technique, which enables us to bound the difference in load between k-hop neighbors on the cycle, for any k ≤ n/2. We complement this with a "gap covering" argument, which bounds the maximum value of the gap by bounding its value across all possible subsets of a certain structure, and recursively bounding the gaps within each subset. We provide analytical and experimental evidence that our upper bound on the gap is tight up to a logarithmic factor.
AU - Alistarh, Dan-Adrian
AU - Nadiradze, Giorgi
AU - Sabour, Amirmojtaba
ID - 8286
SN - 18688969
T2 - Leibniz International Proceedings in Informatics
TI - Dynamic averaging load balancing on cycles
VL - 168
ER -
TY - CONF
AB - Reachability analysis aims at identifying states reachable by a system within a given time horizon. This task is known to be computationally expensive for linear hybrid systems. Reachability analysis works by iteratively applying continuous and discrete post operators to compute states reachable according to continuous and discrete dynamics, respectively. In this paper, we enhance both of these operators and make sure that most of the involved computations are performed in low-dimensional state space. In particular, we improve the continuous-post operator by performing computations in high-dimensional state space only for time intervals relevant for the subsequent application of the discrete-post operator. Furthermore, the new discrete-post operator performs low-dimensional computations by leveraging the structure of the guard and assignment of a considered transition. We illustrate the potential of our approach on a number of challenging benchmarks.
AU - Bogomolov, Sergiy
AU - Forets, Marcelo
AU - Frehse, Goran
AU - Potomkin, Kostiantyn
AU - Schilling, Christian
ID - 8287
KW - Reachability
KW - Hybrid systems
KW - Decomposition
T2 - Proceedings of the International Conference on Embedded Software
TI - Reachability analysis of linear hybrid systems via block decomposition
ER -
TY - JOUR
AB - When can a polyomino piece of paper be folded into a unit cube? Prior work studied tree-like polyominoes, but polyominoes with holes remain an intriguing open problem. We present sufficient conditions for a polyomino with one or several holes to fold into a cube, and conditions under which cube folding is impossible. In particular, we show that all but five special “basic” holes guarantee foldability.
AU - Aichholzer, Oswin
AU - Akitaya, Hugo A.
AU - Cheung, Kenneth C.
AU - Demaine, Erik D.
AU - Demaine, Martin L.
AU - Fekete, Sándor P.
AU - Kleist, Linda
AU - Kostitsyna, Irina
AU - Löffler, Maarten
AU - Masárová, Zuzana
AU - Mundilova, Klara
AU - Schmidt, Christiane
ID - 8317
JF - Computational Geometry: Theory and Applications
SN - 09257721
TI - Folding polyominoes with holes into a cube
VL - 93
ER -
TY - JOUR
AB - We demonstrate that releasing atoms into free space from an optical lattice does not deteriorate cavity-generated spin squeezing for metrological purposes. In this work, an ensemble of 500000 spin-squeezed atoms in a high-finesse optical cavity with near-uniform atom-cavity coupling is prepared, released into free space, recaptured in the cavity, and probed. Up to ∼10 dB of metrologically relevant squeezing is retrieved for 700μs free-fall times, and decaying levels of squeezing are realized for up to 3 ms free-fall times. The degradation of squeezing results from loss of atom-cavity coupling homogeneity between the initial squeezed state generation and final collective state readout. A theoretical model is developed to quantify this degradation and this model is experimentally validated.
AU - Wu, Yunfan
AU - Krishnakumar, Rajiv
AU - Martínez-Rincón, Julián
AU - Malia, Benjamin K.
AU - Hosten, Onur
AU - Kasevich, Mark A.
ID - 8319
IS - 1
JF - Physical Review A
SN - 24699926
TI - Retrieval of cavity-generated atomic spin squeezing after free-space release
VL - 102
ER -
TY - JOUR
AB - The genetic code is considered to use five nucleic bases (adenine, guanine, cytosine, thymine and uracil), which form two pairs for encoding information in DNA and two pairs for encoding information in RNA. Nevertheless, in recent years several artificial base pairs have been developed in attempts to expand the genetic code. Employment of these additional base pairs increases the information capacity and variety of DNA sequences, and provides a platform for the site-specific, enzymatic incorporation of extra functional components into DNA and RNA. As a result, of the development of such expanded systems, many artificial base pairs have been synthesized and tested under various conditions. Following many stages of enhancement, unnatural base pairs have been modified to eliminate their weak points, qualifying them for specific research needs. Moreover, the first attempts to create a semi-synthetic organism containing DNA with unnatural base pairs seem to have been successful. This further extends the possible applications of these kinds of pairs. Herein, we describe the most significant qualities of unnatural base pairs and their actual applications.
AU - Mukba, S. A.
AU - Vlasov, Petr
AU - Kolosov, P. M.
AU - Shuvalova, E. Y.
AU - Egorova, T. V.
AU - Alkalaeva, E. Z.
ID - 8320
IS - 4
JF - Molecular Biology
SN - 00268933
TI - Expanding the genetic code: Unnatural base pairs in biological systems
VL - 54
ER -
TY - JOUR
AB - The genetic code is considered to use five nucleic bases (adenine, guanine, cytosine, thymine and uracil), which form two pairs for encoding information in DNA and two pairs for encoding information in RNA. Nevertheless, in recent years several artificial base pairs have been developed in attempts to expand the genetic code. Employment of these additional base pairs increases the information capacity and variety of DNA sequences, and provides a platform for the site-specific, enzymatic incorporation of extra functional components into DNA and RNA. As a result, of the development of such expanded systems, many artificial base pairs have been synthesized and tested under various conditions. Following many stages of enhancement, unnatural base pairs have been modified to eliminate their weak points, qualifying them for specific research needs. Moreover, the first attempts to create a semi-synthetic organism containing DNA with unnatural base pairs seem to have been successful. This further extends the possible applications of these kinds of pairs. Herein, we describe the most significant qualities of unnatural base pairs and their actual applications.
AU - Mukba, S. A.
AU - Vlasov, Petr
AU - Kolosov, P. M.
AU - Shuvalova, E. Y.
AU - Egorova, T. V.
AU - Alkalaeva, E. Z.
ID - 8321
IS - 4
JF - Molekuliarnaia biologiia
SN - 00268984
TI - Expanding the genetic code: Unnatural base pairs in biological systems
VL - 54
ER -
TY - JOUR
AU - Pach, János
ID - 8323
JF - Discrete and Computational Geometry
SN - 01795376
TI - A farewell to Ricky Pollack
ER -
TY - JOUR
AB - Let 𝐹:ℤ2→ℤ be the pointwise minimum of several linear functions. The theory of smoothing allows us to prove that under certain conditions there exists the pointwise minimal function among all integer-valued superharmonic functions coinciding with F “at infinity”. We develop such a theory to prove existence of so-called solitons (or strings) in a sandpile model, studied by S. Caracciolo, G. Paoletti, and A. Sportiello. Thus we made a step towards understanding the phenomena of the identity in the sandpile group for planar domains where solitons appear according to experiments. We prove that sandpile states, defined using our smoothing procedure, move changeless when we apply the wave operator (that is why we call them solitons), and can interact, forming triads and nodes.
AU - Kalinin, Nikita
AU - Shkolnikov, Mikhail
ID - 8325
JF - Communications in Mathematical Physics
SN - 00103616
TI - Sandpile solitons via smoothing of superharmonic functions
ER -