arXiv subjects

Fang Yu

Publications and source records attributed to Fang Yu.

33 records · Page 2Linked to original sources

arXiv2023

Sign changing bubble tower solutions to a slightly subcritical elliptic problem with non-power nonlinearity

We study the following elliptic problem involving slightly subcritical non-power nonlinearity $$\left\{\begin{array}{lll} -Δu =\frac{|u|^{2^*-2}u}{[\ln(e+|u|)]^ε}\ \ &{\rm in}\ Ω, \\[2mm] u= 0 \ \ & {\rm on}\ \partialΩ, \end{array} \right.$$ where $Ω$ is a bounded smooth domain in $\mathbb{R}^n$, $n\geq 3$, $2^*=\frac{2n}{n-2}$ is the critical Sobolev exponent, $ε>0$ is a small parameter. By the finite dimensional Lyapunov-Schmidt reduction method, we construct a sign changing bubble tower solution with the shape of a tower of bubbles as $ε$ goes to zero.

math.AP↗

arXiv2022

Generalized end-product feedback circuit senses high dimensional environmental fluctuations

Understanding computational capabilities of simple biological circuits, such as the regulatory circuits of single-cell organisms, remains an active area of research. Recent theoretical work has shown that a simple regulatory architecture based on end-product inhibition can exhibit predictive behavior by learning fluctuation statistics of one or two environmental parameters. Here we extend this analysis to higher dimensions. We show that as the number of inputs increases, a generalized version of the circuit can learn not only the dominant direction of fluctuations, as shown previously, but also the subdominant fluctuation modes.

physics.bio-ph↗

arXiv2021

Blind quantum computation for a user who only performs single-qubit gates

Blind quantum computation (BQC) allows a user who has limited quantum capability to complete a quantum computational task with the aid of a remote quantum server, such that the user's input, output, and even the algorithm can be kept hidden from the server. Up to now, there are mainly two models of BQC. One is that the client just needs the ability to prepare single qubits initiated by Broadbent, Fitzsimons, and Kashefi, and the other is that the client only needs perform single-qubit measurements first given by Morimae. In this paper, we put forward a new model of BQC in which a user only requires implementing a few single-qubit gates. We also propose a specific BQC protocol where a user only needs to implement two kinds of single-qubit gates to show the feasibility of the presented model. This circuit model is quite flexible since various users with the ability to perform different single-qubit gates may all have the chance to achieve BQC. Furthermore, compared with the other two models, it may be more suitable for practical implementation in some experimental setups such as trapped ions and superconducting systems since the single-qubit gates are the most exact operations in such systems.

quant-ph↗

arXiv2021

Extracting Lifestyle Factors for Alzheimer's Disease from Clinical Notes Using Deep Learning with Weak Supervision

Since no effective therapies exist for Alzheimer's disease (AD), prevention has become more critical through lifestyle factor changes and interventions. Analyzing electronic health records (EHR) of patients with AD can help us better understand lifestyle's effect on AD. However, lifestyle information is typically stored in clinical narratives. Thus, the objective of the study was to demonstrate the feasibility of natural language processing (NLP) models to classify lifestyle factors (e.g., physical activity and excessive diet) from clinical texts. We automatically generated labels for the training data by using a rule-based NLP algorithm. We conducted weak supervision for pre-trained Bidirectional Encoder Representations from Transformers (BERT) models on the weakly labeled training corpus. These models include the BERT base model, PubMedBERT(abstracts + full text), PubMedBERT(only abstracts), Unified Medical Language System (UMLS) BERT, Bio BERT, and Bio-clinical BERT. We performed two case studies: physical activity and excessive diet, in order to validate the effectiveness of BERT models in classifying lifestyle factors for AD. These models were compared on the developed Gold Standard Corpus (GSC) on the two case studies. The PubmedBERT(Abs) model achieved the best performance for physical activity, with its precision, recall, and F-1 scores of 0.96, 0.96, and 0.96, respectively. Regarding classifying excessive diet, the Bio BERT model showed the highest performance with perfect precision, recall, and F-1 scores. The proposed approach leveraging weak supervision could significantly increase the sample size, which is required for training the deep learning models. The study also demonstrates the effectiveness of BERT models for extracting lifestyle factors for Alzheimer's disease from clinical notes.

cs.CL↗

arXiv2021

Cryptanalysis and improvement of a semi-quantum private comparison protocol based on Bell states

Semi-quantum private comparison (SQPC) allows two participants with limited quantum ability to securely compare the equality of their secrets with the help of a semi-dishonest third party (TP). Recently, Jiang proposed a SQPC protocol based on Bell states (Quantum Inf Process 19(6): 180, 2020) and claimed it is secure. In this paper, we present two types of attack on Jiang's SQPC protocol. In the first type of attack, an outside eavesdropper will make participants accept a wrong result. In the second type of attack, a malicious participant will not only make the other participant accept a wrong result, but also learn the secret of the honest participant. Neither type of attack will be detected. In addition, we propose an improved SQPC protocol that can resist these two types of attack.

quant-ph↗

arXiv2020

Security Improvements of Several Basic Quantum Private Query Protocols with O(log N) Communication Complexity

New quantum private database (with N elements) query protocols are presented and analyzed. Protocols preserve O(logN) communication complexity of known protocols for the same task, but achieve several significant improvements in security, especially concerning user privacy. For example, the randomized form of our protocol has a cheat-sensitive property - it allows the user to detect a dishonest database with a nonzero probability, while the phase-encoded private query protocols for the same task do not have such a property. Moreover, when the database performs the computational basis measurement, a particular projective measurement which can cause a significant loss of user privacy in the previous private query protocols with O(logN) communication complexity, at most half of the user privacy could leak to such a database in our protocol, while in the QPQ protocol, the entire user privacy could leak out. In addition, it is proved here that for large N, the user could detect a cheating via the computational basis measurement, with a probability close to 1/2 using O(\sqrt{N}) special queries. Finally, it is shown here, for both forms of our protocol, basic and randomized, how a dishonest database has to act in case it could not learn user's queries.

cs.CR↗

arXiv2016

Generation and Detection of Surface Plasmon Polaritons by Transition Metal Dichalcogenides for Chip-level Electronic-Photonic Integrated Circuits

The monolithic integration of electronics and photonics has attracted enormous attention due to its potential applications. However, the realization of such hybrid circuits has remained a challenge because it requires optical communication at nanometer scales. A major challenge to this integration is the identification of a suitable material. After discussing the material aspect of the challenge, we identified atomically thin transition metal dichalcogenides (TMDs) as a perfect material platform to implement the circuit. The selection of TMDs is based on their very distinct property: monolayer TMDs are able to emit and absorb light at the same wavelength determined by direct exciton transitions. To prove the concept, we fabricated simple devices consisting of silver nanowires as plasmonic waveguides and monolayer TMDs as active optoelectronic media. Using photoexcitation, direct optical imaging and spectral analysis, we demonstrated generation and detection of surface plasmon polaritons by monolayer TMDs. Regarded as novel materials for electronics and photonics, transition metal dichalcogenides are expected to find new applications in next generation integrated circuits.

cond-mat.mes-hall↗

arXiv2016

Quantum advice enhances social optimality in three-party conflicting interest games

Quantum pseudo-telepathy games are good examples of explaining the strangeness of quantum mechanics and demonstrating the advantage of quantum resources over classical resources. Most of the quantum pseudo-telepathy games are common interest games, nevertheless conflicting interest games are more widely used to model real world situations. Recently Pappa et al. (Phys. Rev. Lett. 114, 020401, 2015) proposed the first two-party conflicting interest game where quantum advice enhances social optimality. In the present paper we give two new three-party conflicting interest games and show that quantum advice can enhance social optimality in a three-party setting. The first game we propose is based on the famous GHZ game which is a common interest game. The second game we propose is related to the Svetlichny inequality which demonstrates quantum mechanics cannot be explained by the local hidden variable model in a three-party setting.

quant-ph↗

arXiv2015

Structurally Stable Singularities for a Nonlinear Wave Equation

For the nonlinear wave equation $u_{tt} - c(u)\big(c(u) u_x\big)_x~=~0$, it is well known that solutions can develop singularities in finite time. For an open dense set of initial data, the present paper provides a detailed asymptotic description of the solution in a neighborhood of each singular point, where $|u_x|\to\infty$. The different structure of conservative and dissipative solutions is analyzed.

math.AP↗

arXiv2014

Total dose radiation and annealing responses of the back transistor of Silicon-On-Insulator pMOSFETs

The total dose radiation and annealing responses of the back transistor of Silicon-On-Insulator (SOI) pMOSFETs have been studied by comparing with those of the back transistor of SOI nMOSFETs fabricated on the same wafer. The transistors were irradiated by 60Co γ-rays with various doses, and the front transistors are biased in a Float-State and Off-State, respectively, during irradiation. The total dose radiation responses of the back transistors are characterized by their threshold voltage shifts. The results show that the total dose radiation response of the back transistor of SOI pMOSFETs, similar to that of SOI nMOSFETs, depends greatly on their bias conditions during irradiation. However, with the Float-State bias, rather than the Off-State bias, the back transistors of SOI pMOSFETs reveal a much higher sensitivity to total dose radiation, which is contrary to those of SOI nMOSFETs. In addition, it is also found that the total dose radiation effect of the back transistor of SOI pMOSFETs irradiated with Off-State bias, as well as that of the SOI nMOSFETs, exhibits an increasing trend as the channel length decreases. The annealing response of the back transistors after irradiation at room temperature without bias, characterized by their threshold voltage shifts, indicates that there is a relatively complex annealing mechanism associated with channel length and type, bias condition during irradiation. In particular, for all the transistors irradiated with Off-State bias, their back transistors show an abnormal annealing effect during early annealing. All the results have been discussed and analyzed in detail by the aid of simulation.

physics.ins-det↗

arXiv2014

A holographic p-wave superfluid

In the probe limit, we numerically construct a holographic p-wave superfluid model in the 4D and 5D AdS black holes coupled to a Maxwell-complex vector field. We find that, for the condensate with the fixed superfluid velocity, the results are similar to the s-wave cases in both 4D and 5D spacetimes. In particular, "The Cave of Winds" and the phase transition always being the second order take place in the 5D case. Moreover, we find the second-first order translating point $\frac{S_y}μ$ increases with the mass squared. Furthermore, for the supercurrent with the fixed temperature, the results agree with the GL prediction near the critical temperature. In addition, this complex vector superfluid model is still a generalization of the SU(2) superfluid model, and also provides a holographic realization of the $He_3$ superfluid system.

hep-th↗

arXiv2014

Structural Stability of Supersonic Contact Discontinuities in Three-Dimensional Compressible Steady Flows

In this paper, we study the structurally nonlinear stability of supersonic contact discontinuities in three-dimensional compressible isentropic steady flows. Based on the weakly linear stability result and the $L^2$-estimates obtained by the authors in J. Diff. Equ. 255(2013), for the linearized problems of three-dimensional compressible isentropic steady equations at a supersonic contact discontinuity satisfying certain stability conditions, we first derive tame estimates of solutions to the linearized problem in higher order norms by exploring the behavior of vorticities. Since the supersonic contact discontinuities are only weakly linearly stable, so the tame estimates of solutions to the linearized problems have loss of regularity with respect to both of background states and initial data, so to use the tame estimates to study the nonlinear problem we adapt the Nash-Moser-Hörmander iteration scheme to conclude that weakly linearly stable supersonic contact discontinuities in three-dimensional compressible steady flows are also structurally nonlinearly stable.

math.AP↗

arXiv2011

Proceedings 13th International Workshop on Verification of Infinite-State Systems

This volume contains the proceedings of the 13th International Workshop on Verification of Infinite-State Systems (INFINITY 2011). The workshop was held in Taipei, Taiwan on October 10, 2011, as a satellite event to the 9th International Symposium on Automated Technology for Verification and Analysis (ATVA). The INFINITY workshop aims at providing a forum for researchers who are interested in the development of formal methods and algorithmic techniques for the analysis of systems with infinitely many states, and their application in automated verification of complex software and hardware systems.

cs.LO↗

arXiv2003

TCTL Inevitability Analysis of Dense-time Systems

Inevitability properties in branching temporal logics are of the syntax forall eventually ϕ, where ϕis an arbitrary (timed) CTL formula. In the sense that "good things will happen", they are parallel to the "liveness" properties in linear temporal logics. Such inevitability properties in dense-time logics can be analyzed with greatest fixpoint calculation. We present algorithms to model-check inevitability properties both with and without requirement of non-Zeno computations. We discuss a technique for early decision on greatest fixpoints in the temporal logics, and experiment with the effect of non-Zeno computations on the evaluation of greatest fixpoints. We also discuss the TCTL subclass with only universal path quantifiers which allows for the safe abstraction analysis of inevitability properties. Finally, we report our implementation and experiments to show the plausibility of our ideas.

cs.SC↗

arXiv2003

Numerical Coverage Estimation for the Symbolic Simulation of Real-Time Systems

Three numerical coverage metrics for the symbolic simulation of dense-time systems and their estimation methods are presented. Special techniques to derive numerical estimations of dense-time state-spaces have also been developed. Properties of the metrics are also discussed with respect to four criteria. Implementation and experiments are then reported.

cs.SE↗