arXiv subjects

Haoyang Wu

Publications and source records attributed to Haoyang Wu.

36 records · Page 2Linked to original sources

arXiv2023

Constructing a type-adjustable mechanism to yield Pareto-optimal outcomes

In mechanism design theory, agents' types are described as their private information, and the designer may reveal some public information to affect agents' types in order to obtain more payoffs. Traditionally, each agent's private type and the public information are represented as a random variable respectively. In this paper, we propose a type-adjustable mechanism where each agent's private type is represented as a function of two parameters, \emph{i.e.}, his intrinsic factor and an external factor. Each agent's intrinsic factor is modeled as a private random variable, and the external factor is modeled as a solution of the designer's optimization problem. If the designer chooses an optimal value of external factor as public information, the type-adjustable mechanism may yield Pareto-optimal outcomes, which let the designer and each agent obtain more expected payoffs than what they would obtain at most in the traditional optimal mechanisms. As a comparison, in an auction with interdependent values, only the seller will benefit from public information which is represented as a random variable. We propose a revised version of revelation principle for type-adjustable Bayesian equilibrium. In the end, we compare the type-adjustable mechanism with other relevant models.

econ.TH↗

arXiv2023

Scaling and mechanism of the propagation speed of the upstream turbulent front in pipe flow

Scaling and mechanism of the propagation speed of turbulent fronts in pipe flow with the Reynolds number has been a long-standing problem in the past decades. Here, we derive an explicit scaling law of the upstream front speed, which approaches to a power-law scaling at high Reynolds numbers and explain the underlying mechanism. Our data show that the average wall distance of low-speed streaks at the tip of the upstream front, where transition occurs, appears to be constant in local wall units in the wide bulk-Reynolds-number range investigated, between 5000 and 60000. By further assuming that the axial propagation of velocity fluctuations at the front tip, resulting from streak instabilities, is dominated by the advection of the local mean flow, the front speed can be derived as an explicit function of the Reynolds number. The derived formula agrees well with the measured speed by front tracking. Our finding reveals the relationship between the structure and speed of a front, which enables to obtain a close approximation of the front speed based on a single velocity field without having to track the front over time.

physics.flu-dyn↗

arXiv2022

mm-Wave Radar Hand Shape Classification Using Deformable Transformers

A novel, real-time, mm-Wave radar-based static hand shape classification algorithm and implementation are proposed. The method finds several applications in low cost and privacy sensitive touchless control technology using 60 Ghz radar as the sensor input. As opposed to prior Range-Doppler image based 2D classification solutions, our method converts raw radar data to 3D sparse cartesian point clouds.The demonstrated 3D radar neural network model using deformable transformers significantly surpasses the performance results set by prior methods which either utilize custom signal processing or apply generic convolutional techniques on Range-Doppler FFT images. Experiments are performed on an internally collected dataset using an off-the-shelf radar sensor.

cs.CV↗

arXiv2022

A numerical study of the side-wall effects on turbulent bands in channel flow at transitional Reynolds numbers

We investigated the side-wall effects on turbulent bands in channel flow at transitional Reynolds numbers by direct numerical simulations using the open source spectral-element code Nektar++. The width-to-height aspect ratio of 50:1 is considered for this study. Our study shows that turbulent bands can survive the collision with the side wall above bulk Reynolds number of Re around 1000 but decay below Re around 975, i.e. the critical Reynolds number should be approximately between the two Reynolds numbers. We also discussed about the underlying mechanism for the decay of the band at low Reynolds numbers and potential effects of larger spanwise channel widths than that considered in our study. The results are informative for experimental studies of channel flow turbulence at transitional Reynolds numbers.

physics.flu-dyn↗

arXiv2020

The revelation principle fails when the format of each agent's strategy is an action

In mechanism design theory, a designer would like to implement a social choice function which specifies her favorite outcome for each possible profile of agents' private types. The revelation principle asserts that if a social choice function can be implemented by a mechanism in equilibrium, then there exists a direct mechanism that can truthfully implement it. This paper aims to propose a failure of the revelation principle. We point out that in any game the format of each agent's strategy is either an informational message or a realistic action, and the action format is very common in many practical cases. The main result is that: For any given social choice function, if the mechanism which implements it has action-format strategies, then "\emph{honest and obedient}" will no longer be the Bayesian Nash equilibrium of the direct mechanism, actually the social choice function can only be implemented "\emph{dishonestly and disobediently}" in Bayesian Nash equilibrium by the direct mechanism. Consequently, the revelation principle fails when the format of each agent's strategy is an action.

cs.GT↗

arXiv2020

On the nonlinearity of a tuning fork

Tuning fork experiments at the undergraduate level usually only demonstrate a tuning fork's linear resonance. In this paper, we introduce an experiment that can be used to measure the nonlinear tuning curve of a regular tuning fork. Using double-grating Doppler interferometry, we achieve measurement accuracy within ten microns. With this experiment setup, we observe typical nonlinear behaviors of the tuning fork such as the softening tuning curve and jump phenomena. Our experiment is inexpensive and easy to operate. It provides an integrated experiment for intermediate-level students and a basis for senior research projects.

physics.app-ph↗

arXiv2019

Profitable Bayesian implementation in one-shot mechanism settings

In the mechanism design theory, a designer would like to implement a desired social choice function which specifies her favorite outcome for each possible profile of all agents' types. Traditionally, the designer may be in a dilemma in the sense that even if she is not satisfied with some outcome with low profit, she has to announce it because she must obey the mechanism designed by herself. In this paper, we investigate a case where the designer can induce each agent to adjust his type in a one-shot mechanism. We propose that for a profitable Bayesian implementable social choice function, the designer may escape from the above-mentioned dilemma by spending the optimal adjustment cost and obtain a higher profit. Finally, we construct an example to show that the designer can breakthrough the limit of expected profit which she can obtain at most in the traditional optimal auction model.

cs.GT↗

arXiv2019

A note on the definition of Bayesian Nash equilibrium of a mechanism when strategies of agents are costly actions

In mechanism design theory, a designer would like to implement a desired social choice function which specifies her favorite outcome for each possible profile of agents' types. To do so, the designer constructs a mechanism which describes each agent's feasible strategy set and the outcome function. Generally speaking, each agent's strategy in a mechanism has two possible formats: an action, or a message. In this paper, we focus on the former format and claim that the notion of Bayesian Nash equilibrium of a mechanism should be based on a profit function instead of the conventional utility function when strategies of agents are costly actions. Next, we derive the main result: Given a social choice function which can be implemented by an indirect mechanism in Bayesian Nash equilibrium, if all strategies of agents are costly actions, then it cannot be inferred that there exists a direct mechanism that can truthfully implement the social choice function in Bayesian Nash equilibrium.

cs.GT↗

arXiv2015

A note on revelation principle from an energy perspective

The revelation principle has been known in the economics society for decades. In this paper, I will investigate it from an energy perspective, i.e., considering the energy consumed by agents and the designer in participating a mechanism. The main result is that when the strategies of agents are actions rather than messages, an additional energy condition should be added to make the revelation principle hold in the real world.

cs.GT↗

arXiv2012

Traditional sufficient conditions for Nash implementation may fail on Internet

The Maskin's theorem is a fundamental work in the theory of mechanism design. In this paper, we propose that if agents report messages to the designer through channels (e.g., Internet), agents can construct a self-enforcing agreement such that any Pareto-inefficient social choice rule satisfying monotonicity and no-veto will not be Nash implementable when an additional condition is satisfied. The key points are: 1) The agreement is unobservable to the designer, and the designer cannot prevent the agents from constructing such agreement; 2) The agents act non-cooperatively, and the Maskin mechanism remain unchanged from the designer's perspective.

cs.GT↗

arXiv2012

On amending the Maskin's sufficiency theorem by using complex numbers

The Maskin's theorem is a fundamental work in the theory of mechanism design. In this paper, we will propose a self-enforcing agreement by which agents can fight a bad social choice rule which satisfies monotonicity and no-veto if an additional condition is satisfied. The agreement is based on complex numbers and is justified if the designer receives messages from the agents through some communication channels (e.g., Internet). Under the assumption of complete information among agents, the designer cannot prevent the agents from signing such agreement. Thereby, the Maskin's sufficiency theorem is amended.

physics.soc-ph↗

arXiv2011

Quantum Bayesian implementation

Bayesian implementation concerns decision making problems when agents have incomplete information. This paper proposes that the traditional sufficient conditions for Bayesian implementation shall be amended by virtue of a quantum Bayesian mechanism. In addition, by using an algorithmic Bayesian mechanism, this amendment holds in the macro world.

physics.data-an↗

arXiv2011

A non-cooperative Pareto-efficient solution to a one-shot Prisoner's Dilemma

The Prisoner's Dilemma is a simple model that captures the essential contradiction between individual rationality and global rationality. Although the one-shot Prisoner's Dilemma is usually viewed simple, in this paper we will categorize it into five different types. For the type-4 Prisoner's Dilemma game, we will propose a self-enforcing algorithmic model to help non-cooperative agents obtain Pareto-efficient payoffs. The algorithmic model is based on an algorithm using complex numbers and can work in macro applications.

cs.GT↗

arXiv2011

Quantum mechanism helps agents combat "bad" social choice rules

Quantum strategies have been successfully applied to game theory for years. However, as a reverse problem of game theory, the theory of mechanism design is ignored by physicists. In this paper, the theory of mechanism design is generalized to a quantum domain. The main result is that by virtue of a quantum mechanism, agents who satisfy a certain condition can combat "bad" social choice rules instead of being restricted by the traditional mechanism design theory.

physics.soc-ph↗

arXiv2011

Two-agent Nash implementation: A new result

[J. Moore and R. Repullo, \emph{Econometrica} \textbf{58} (1990) 1083-1099] and [B. Dutta and A. Sen, \emph{Rev. Econom. Stud.} \textbf{58} (1991) 121-128] are two important papers on two-agent Nash implementation. Recently, [H. Wu, Quantum mechanism helps agents combat "bad" social choice rules. \emph{International Journal of Quantum Information}, 2010 (accepted). abs/1002.4294 ] broke through traditional results on Nash implementation with three or more agents. In this paper, we will investigate two-agent Nash implementation by virtue of Wu's quantum mechanism. The main result is: A two-agent social choice rule that satisfies Condition $\mu2$ will no longer be Nash implementable if an additional Condition $λ'$ is satisfied. Moreover, according to a classical two-agent algorithm, this result holds not only in the quantum world, but also in the macro world.

cs.GT↗

arXiv2011

Subgame perfect implementation: A new result

This paper concerns what will happen if quantum mechanics is concerned in subgame perfect implementation. The main result is: When additional conditions are satisfied, the traditional characterization on subgame perfect implementation shall be amended by virtue of a quantum stage mechanism. Furthermore, by using an algorithmic stage mechanism, this amendment holds in the macro world too.

physics.data-an↗

arXiv2010

On the justification of applying quantum strategies to the Prisoners' Dilemma and mechanism design

The Prisoners' Dilemma is perhaps the most famous model in the field of game theory. Consequently, it is natural to investigate its quantum version when one considers to apply quantum strategies to game theory. There are two main results in this paper: 1) The well-known Prisoners' Dilemma can be categorized into three types and only the third type is adaptable for quantum strategies. 2) As a reverse problem of game theory, mechanism design provides a better circumstance for quantum strategies than game theory does.

quant-ph↗

arXiv2010

Signaling games with pattern recognition

The classical model of signaling games assumes that the receiver exactly know the type space (private information) of the sender and be able to discriminate each type of the sender distinctly. However, the justification of this assumption is questionable. It is more reasonable to let the receiver recognize the pattern of the sender. In this paper, we investigate what happens if the assumption is relaxed. A framework of signaling games with pattern recognition and an example are given.

cs.GT↗