Cooperative Counterpart Research Articles

Function Approximation for Solving Stackelberg Equilibrium in Large Perfect Information Games

Function approximation (FA) has been a critical component in solving large zero-sum games. Yet, little attention has been given towards FA in solving general-sum extensive-form games, despite them being widely regarded as being computationally more challenging than their fully competitive or cooperative counterparts. A key challenge is that for many equilibria in general-sum games, no simple analogue to the state value function used in Markov Decision Processes and zero-sum games exists. In this paper, we propose learning the Enforceable Payoff Frontier (EPF)---a generalization of the state value function for general-sum games. We approximate the optimal Stackelberg extensive-form correlated equilibrium by representing EPFs with neural networks and training them by using appropriate backup operations and loss functions. This is the first method that applies FA to the Stackelberg setting, allowing us to scale to much larger games while still enjoying performance guarantees based on FA error. Additionally, our proposed method guarantees incentive compatibility and is easy to evaluate without having to depend on self-play or approximate best-response oracles.

(Don’t) bite the hand that feeds you: do critical interest organizations gain less funding in the EU?

AbstractIn this study we test whether interest organizations that are confrontational towards EU institutions are less successful than their more cooperative counterparts in obtaining funding from the European Commission (EC). The transfer of public funds to interest organizations is a key dynamic in state-civil society relationships. Research shows that organizations, especially public groups, often heavily rely on public funds to the point that, without funds, many would cease to exist. ‘Don’t bite the hand that feeds you’ is thus a popular expression among leaders of organizations who apply for funds. Scholars document a widespread perception among group leaders that a confrontational attitude towards the state can lead to curtail of public funds. This perception is based on the assumption that state institutions use public funding to discipline confrontational interest organizations. We test this assumption using quantitative and qualitative data collected from a survey of 270 interest organizations who applied for EC funding between 2015 and 2018. Our findings suggest that, while almost half of our survey respondents feel that critical attitudes towards the EU would have negative consequences for their funding applications, empirically, confrontational and cooperative organizations have the same chances of obtaining EC grants. This finding is robust across different interest organization categories, including when non-applicants and mortality anxiety are considered in the analysis. The results add a new layer to resource dependency theory pointing at the incongruence between an organization’s perception of its relationship with public institutions and the observation of that relationship.

Sixty-seven years of the Nash program: time for retirement?

The Nash program is an important research agenda initiated in Nash (Econometrica 21:128–140, 1953) in order to bridge the gap between the noncooperative and cooperative counterparts of game theory. The program is thus turning sixty-seven years old, but I will argue it is not ready for retirement, as it is full of energy and one can still propose important directions to be explored. This paper completes and updates previous surveys, and suggests several directions for future research.

Sixty-Seven Years of the Nash Program: Time for Retirement?

The Nash program is an important research agenda initiated in Nash (1953) in order to bridge the gap between the noncooperative and cooperative counterparts of game theory. The program is thus turning sixty-seven years old, but I will argue it is not ready for retirement, as it is full of energy and one can still propose important directions to be explored. This paper completes and updates previous surveys, and suggests several directions for future research.

QoS-Aware Buffer-Aided Relaying Implant WBAN for Healthcare IoT: Opportunities and Challenges

Internet of Things (IoT) have motivated a paradigm shift in the development of various applications such as mobile health. Wireless body area network (WBAN) comprises many low-power devices in, on, or around the human body, which offers a desirable solution to monitor physiological signals for mobile-health applications. In the implant WBAN, an implant medical device transmits its measured biological parameters to a target hub with the help of at least one on-body device(s) to satisfy its strict requirements on size, quality of service (QoS, e.g., reliability), and power consumption. In this article, we first review the recent advances of conventional cooperative WBAN. Afterwards, to address the drawbacks of the conventional cooperative WBAN, a QoS-aware buffer-aided relaying framework is proposed for the implant WBAN. In the proposed framework, hierarchical modulations are considered to fulfill the different QoS requirements of different sensor data from an implant medical device. We further conceive some new transmission strategies for the buffer-aided signal-relay and multi-relay implant WBANs. Simulation results show that the proposed cooperative WBAN provides better performance than the conventional cooperative counterparts. Finally, some open research challenges regarding the buffer-aided multi-relay implant WBAN are pointed out to inspire more research activities.

Synthetic transcriptional synergy.

Synthetic transcription factors can mimic their naturally cooperative counterparts

Kernel Flows: From learning kernels from data into the abyss

Learning can be seen as approximating an unknown function by interpolating the training data. Although Kriging offers a solution to this problem, it requires the prior specification of a kernel and it is not scalable to large datasets. We explore a numerical approximation approach to kernel selection/construction based on the simple premise that a kernel must be good if the number of interpolation points can be halved without significant loss in accuracy (measured using the intrinsic RKHS norm ‖⋅‖ associated with the kernel). We first test and motivate this idea on a simple problem of recovering the Green's function of an elliptic PDE (with inhomogeneous coefficients) from the sparse observation of one of its solutions. Next we consider the problem of learning non-parametric families of deep kernels of the form K1(Fn(x),Fn(x′)) with Fn+1=(Id+ϵGn+1)∘Fn and Gn+1∈span{K1(Fn(xi),⋅)}. With the proposed approach constructing the kernel becomes equivalent to integrating a stochastic data driven dynamical system, which allows for the training of very deep (bottomless) networks and the exploration of their properties. These networks learn by constructing flow maps in the kernel and input spaces via incremental data-dependent deformations/perturbations (appearing as the cooperative counterpart of adversarial examples) and, at profound depths, they (1) can achieve accurate classification from only one data point per class (2) appear to learn archetypes of each class (3) expand distances between points that are in different classes and contract distances between points in the same class. For kernels parameterized by the weights of Convolutional Neural Networks, minimizing approximation errors incurred by halving random subsets of interpolation points, appears to outperform training (the same CNN architecture) with relative entropy and dropout.

On Stability and Trajectory Boundedness of Lotka–Volterra Systems With Polytopic Uncertainty

A new approach is proposed to study the stability property of the feasible equilibrium point and the trajectory boundedness of the Lotka-Volterra (LV) dynamics in the presence of polytopic uncertainties. Stability analysis of general LV systems is not straightforward in comparison with its cooperative counterpart. It is shown that, under specific conditions, the trajectory of the cooperative counterpart of the LV system can be considered as an upper bound for the trajectory of the corresponding dynamics. Consequently, the stability of the cooperative counterpart of the LV system leads to boundedness of the trajectory. The obtained results are extended for the LV systems with polytopic uncertainties. It is shown that under specific conditions, there is a region which the trajectory of the system belongs to it as time tends to infinity. Also, the stability of LV systems with polytopic uncertainty is investigated. The obtained results are confirmed through some numerical/application-based examples.

Cooperative Detection-Assisted Localization in Wireless Networks in the Presence of Ranging Outliers

Location-aware wireless networks can provide precise location information in harsh environments, however, which is only possible when all nodes are well-functioning. In this paper, we propose algorithms and analyze the performance limits for both non-cooperative and cooperative localization networks in the presence of ranging outliers. Especially, we show that the localization performance can be boosted by using the cooperative outlier detection scheme. An algorithm based on expectation-maximization is proposed for non-cooperative localization networks, while a variational message passing-based algorithm is proposed for the cooperative counterparts. Performance limits are investigated using Cramer–Rao lower bound. Further inspection on the performance limits confirms the performance gain from the cooperative detection scheme. Stochastic geometric analysis is also carried out to account for the stochastic nature of wireless networks, as well as to provide simpler expressions and additional insights. Simulation results corroborate the analytical results, and show that both of the proposed algorithms are capable of attaining the corresponding performance limits at a significantly reduced computational cost compared with existing algorithms.

On the connection between Nash equilibria and social optima in electric vehicle charging control games

We consider the problem of optimal charging of heterogeneous plug-in electric vehicles (PEVs). We approach the problem as a multi-agent game in the presence of constraints and formulate an auxiliary minimization program whose solution is shown to be the unique Nash equilibrium of the PEV charging control game, for any finite number of possibly heterogeneous agents. Assuming that the parameters defining the constraints of each vehicle are drawn randomly from a given distribution, we show that, as the number of agents tends to infinity, the value of the game achieved by the Nash equilibrium and the social optimum of the cooperative counterpart of the problem under study coincide for almost any choice of the random heterogeneity parameters. To the best of our knowledge, this result quantifies for the first time the asymptotic behaviour of the price of anarchy for this class of games. A numerical investigation to support our result is also provided.

Aggression as a Motive for Gossip During Conflict: The Role of Power, Social Value Orientation, and Counterpart's Behavior

AbstractNot much is known about the motives behind the use of gossip in conflict situations. We report a laboratory experiment that examined the influence of social value orientation, counterpart's behavior, and power on the motive to use gossip for indirect aggression in a conflict situation. Results showed that when participants had high power, their social value orientation determined whether they were motivated to gossip to indirectly aggress toward their counterpart: Proself participants showed a higher motivation to do so than prosocial participants. In contrast, when participants had low power, the motive to engage in indirect aggression through gossip was influenced by the counterpart's behavior: Participants who encountered a competitive counterpart showed a higher motivation to aggress through gossip than participants who encountered a cooperative counterpart.

Spatial arrangement and acid strength effects on acid–base cooperatively catalyzed aldol condensation on aminosilica materials

Weak acids are known to enhance the activity of amines in aldol condensation reactions on silica-based catalysts. The effects of acid strength and arrangement of the promoting site with respect to a secondary amine have been investigated in the aldol condensation of 4-nitrobenzaldehyde with acetone. Changing the substituent of this secondary amine from a methyl to an ethyl group decreases the activity. An intramolecular OH function provided by a primary alcohol incorporated on the β-carbon of the amine substituent exhibits a similar cooperativity as an intermolecular OH function provided by neighboring surface silanols. A maximum activity was achieved when the secondary amine with the same primary alcohol-containing substituent was surrounded by surface silanols, indicating the potential advantage of simultaneously activating both reactants by the formation of a hydrogen bond in contrast to the consecutive activation when there is only one promoting site in the vicinity of the amine. Changing the alcohol to stronger acids resulted in a reduced cooperativity with increasing acid strength. After removing the silanols from the surface, the activity of the catalysts which exhibit an intramolecular cooperativity retained about 68–83% of their activities while the activity of the conventional secondary amine was reduced by a factor of four compared to its intermolecularly cooperative counterpart.

Reduced brain reward response during cooperation in first-degree relatives of patients with psychosis: an fMRI study.

Psychosis is characterized by a profound lack of trust and disturbed social interactions. Investigating the neural basis of these deficits is difficult because of medication effects but first-degree relatives show qualitatively similar abnormalities to patients with psychosis on various tasks. This study aimed to investigate neural activation in siblings of patients in response to an interactive task. We hypothesized that, compared to controls, siblings would show (i) less basic trust at the beginning of the task and (ii) reduced activation of the brain reward and mentalizing systems. Functional magnetic resonance imaging (fMRI) data were acquired on 50 healthy siblings of patients with psychosis and 33 healthy controls during a multi-round trust game with a cooperative counterpart. An a priori region-of-interest (ROI) analysis of the caudate, temporoparietal junction (TPJ), superior temporal sulcus (STS), insula and medial prefrontal cortex (mPFC) was performed focusing on the investment and repayment phases. An exploratory whole-brain analysis was run to test for group-wise differences outside these ROIs. The siblings' behaviour during the trust game did not differ significantly from that of the controls. At the neural level, siblings showed reduced activation of the right caudate during investments, and the left insula during repayments. In addition, the whole-brain analysis revealed reduced putamen activation in siblings during investments. The findings suggest that siblings show aberrant functioning of regions traditionally involved in reward processing in response to cooperation, which may be associated with the social reward deficits observed in psychosis.

Reputational Priors Magnify Striatal Responses to Violations of Trust

Humans learn to trust each other by evaluating the outcomes of repeated interpersonal interactions. However, available prior information on the reputation of traders may alter the way outcomes affect learning. Our functional magnetic resonance imaging study is the first to allow the direct comparison of interaction-based and prior-based learning. Twenty participants played repeated trust games with anonymous counterparts. We manipulated two experimental conditions: whether or not reputational priors were provided, and whether counterparts were generally trustworthy or untrustworthy. When no prior information is available our results are consistent with previous studies in showing that striatal activation patterns correlate with behaviorally estimated reinforcement learning measures. However, our study additionally shows that this correlation is disrupted when reputational priors on counterparts are provided. Indeed participants continue to rely on priors even when experience sheds doubt on their accuracy. Notably, violations of trust from a cooperative counterpart elicited stronger caudate deactivations when priors were available than when they were not. However, tolerance to such violations appeared to be mediated by prior-enhanced connectivity between the caudate nucleus and ventrolateral prefrontal cortex, which anticorrelated with retaliation rates. Moreover, on top of affecting learning mechanisms, priors also clearly oriented initial decisions to trust, reflected in medial prefrontal cortex activity.

Flattening the carbon extraction path in unilateral cost-effective action

Internalizing the global negative externality of carbon emissions requires the flattening of the extraction path of world fossil energy resources (=world carbon emissions). We consider governments with sign-unconstrained emission taxes at their disposal and seeking to prevent world emissions from exceeding some binding aggregate emission ceiling in the medium term. Such a ceiling policy can be carried out either in full cooperation or by a sub-global climate coalition. Unilateral action has to cope with carbon leakage and high costs, which makes a strong case for choosing a policy that implements the ceiling in a cost-effective way. In a two-country, two-period general equilibrium model with a non-renewable fossil-energy resource, we characterize the unilateral cost-effective ceiling policy and compare it with its fully cooperative counterpart. We show that with full cooperation there exists a cost-effective ceiling policy in which only first-period emissions are taxed at a rate that is uniform across countries. In contrast, the cost-effective ceiling policy of a sub-global climate coalition is characterized by emission regulation in both periods. The share of the total stock of energy resources owned by the sub-global climate coalition turns out to be a decisive determinant of the sign and magnitude of unilateral cost-effective taxes.

The Effect of Negotiators’ Own Social Motives and Their Counterparts’ Social Motives on Trust

Although much is known about the effect of negotiators’ social motives on trust, little is known about how negotiators’ own social motives interact with their counterparts’ social motives. Based on false consensus effect, expectancy disconfirmation and negativity bias, we propose and test two sets of alternative hypotheses on the effects of negotiators’ own social motives and their counterpart’s social motives in a negotiation experiment. We predict that negotiating with an individualistic counterpart leads to lower trust than negotiating with a cooperative counterpart (H1a), especially for cooperators (H2a). Results of our study (N= 76) provided stronger support for H2a: Cooperative negotiators had lower trust when they negotiated with individualistic counterparts than when they negotiated with cooperative counterparts whereas individualistic negotiators were not influenced by their counterparts’ social motivation. Our mediation analysis showed that this happened because cooperators expected more coopera...

Flattening the Carbon Extraction Path in Unilateral Cost-Effective Action

Internalizing the global negative externality of carbon emissions requires flattening the extraction path of world fossil energy resources (= world carbon emissions). We consider governments having sign-unconstrained emission taxes at their disposal and seeking to prevent world emissions from exceeding some binding aggregate emission ceiling in the medium term. Such a ceiling policy can be carried out either in full cooperation of all (major) carbon emitting countries or by a sub-global climate coalition. Unilateral action has to cope with carbon leakage and high costs which makes a strong case for choosing a policy that implements the ceiling in a cost-effective way. In a two-country two-period general equilibrium model with a non-renewable fossil-energy resource we characterize the unilateral cost-effective ceiling policy and compare it with its fully cooperative counterpart. We show that with full cooperation there exists a cost-effective ceiling policy in which only first-period emissions are taxed at a rate that is uniform across countries. In contrast, the cost-effective ceiling policy of a sub-global climate coalition is characterized by emission regulation in both periods. That policy may consist either of positive tax rates in both periods or of negative tax rates (= subsidies) in both periods or of a positive rate in the first and a negative rate in the second period. The share of the total stock of energy resources owned by the sub-global climate coalition turns out to be a decisive determinant of the sign and magnitude of unilateral cost-effective taxes.

Competition and Risk in Japanese Banking

We investigate whether the relationship between competition and risk varies across different types of Japanese banks over the period 2000-2009. The results of our empirical investigation show that risk varies across bank types. Specifically, nationwide (City and Trust) banks are riskier on average than their counterparts (Regional, Tier 2 Regional, Shinkin and Credit Cooperative banks) with a regional focus The relationship between competition and risk also varies across bank types based on different initial levels of risk. Iincreasing competition appears to reduce the risk of (City) banks with higher initial levels of risk, but increase the risk of their (Regional, Tier 2 Regional, Shinkin and Credit Cooperative) counterparts with lower initial levels of risk.

To Assess the Rise of China

Fei-Ling Wang • http://asiapolicy.nbr.org • asia policy, number 8 (july 2009), 151–59 Robert S. Ross and Zhu Feng, eds. China’s Ascent: Power, Security, and the Future of International Politics Ithaca, NY: Cornell University Press, 2008 • 336 pp. C. Fred Bergsten, Charles Freeman, Nicholas R. Lardy, and Derek J. Mitchell China’s Rise: Challenges and Opportunities Washington, D.C.: Peterson Institute for International Economics, 2008 • 256 pp. David M. Lampton The Three Faces of Chinese Power: Might, Money, and Minds Berkeley: University of California Press, 2008 • 361 pp. review essay To Assess the Rise of China Fei-Ling Wang© The National Bureau of Asian Research, Seattle, Washington [ 152 ] asia policy China’s Ascent: Power, Security, and the Future of International Politics Robert S. Ross and Zhu Feng, eds. Ithaca, NY: Cornell University Press, 2008 • 336 pp. editors’ executive summary Thisvolumeisacollaborativeeffortinapplyinginternationalrelationstheories to the dynamics brought on by the rise of China and the resulting U.S.-China power transition. main argument Past examples of great-power transitions help explain the changes being brought about by China’s ascent. Though conflicts of interest between the U.S. and China will continue, the intensity and direction of the transition will be determined by four main factors: (1) structural variables that influence the transition, with specific importance on the polarity of the modernday international system, the geographical characteristics of great-power placement,andweapontechnologies,(2)China’sparticipationininternational politics and ability to create and influence international institutions, (3) Chinese state-level variables that operate within the context of international and regional structures, and within the context of international institutions, and (4) the influence of Chinese decisionmaking on the behavior of other countries and vice versa. policy implications • The particular global and regional structural context of U.S.-China competition, though increasingly strained due to growing conflicts of interest, has the potential to facilitate a peaceful power transition. • China has become an engaged beneficiary of the contemporary international institutional order and possesses an interest in maintaining and consolidating this order. • The combined effects of Chinese and U.S. participation in global institutions and Chinese involvement in regional institutions can mitigate the competition inherent in the U.S.-China power transition. [ 153 ] review essay • to assess the rise of china China’s Rise: Challenges and Opportunities C. Fred Bergsten, Charles Freeman, Nicholas R. Lardy, and Derek J. Mitchell Washington, D.C.: Peterson Institute for International Economics, 2008 • 256 pp. authors’ executive summary This book examines the dynamics underpinning China’s rise and suggests U.S. policy responses to further encourage China’s constructive integration into the international community. main argument China poses enormous challenges and opportunities to the U.S. and the world. As China continues to evolve and debate its future course, U.S. interests can be best protected by engaging China actively during this formative period, and by helping the country develop the tools, infrastructure, and policies that will enable Beijing to become a cooperative counterpart to Washington in global affairs. The U.S. should support reconfiguration of the global architecture to incorporateChinaintothediscussionbothofthedevelopmentofinternational rules and of what it means to be a “responsible stakeholder.” policy implications • Given that China faces significant domestic challenges—which include developing democracy with Chinese characteristics and handling relations between the central and local governments—U.S. policy goals would benefit by enhancing exchanges among officials, politicians, academics, and business groups that help China manage these challenges. • China’sunbalancedeconomicdevelopment,especiallyitsenergy‑intensive heavy industry and investment-led growth, has aggravated income inequality, heightened trade tensions, and contributed to serious environmental problems. More vigorous Chinese policy action is needed in the fiscal, financial, exchange rate, and pricing domains. The U.S. can work with China on climate change through a multilateral framework. • The U.S. must ensure that China enhances PLA transparency and understands continued U.S. regional commitments and capabilities, all the while seeking to work with China where there are mutual interests. • As China has the potential to contribute to the resolution of a broad range of global issues, its expanding engagement with the world, channeled constructively, should be welcomed. [ 154 ] asia policy T h e Three Faces of Chinese Power: Might, Money, and Minds David M. Lampton Berkeley...

Cooperative Relay Broadcast Channels

The capacity regions are investigated for two relay broadcast channels (RBCs), where relay links are incorporated into two-user broadcast channels to support user cooperation. In the first channel, the partially cooperative RBC, only one user in the system acts as a relay. An achievable rate region is derived based on the relay using the decode-and-forward scheme. An outer bound on the capacity region is derived and is shown to be tighter than the cut-set bound. For the special case where the partially cooperative RBC is degraded, the achievable rate region is shown to be the capacity region. Two Gaussian cases of the partially cooperative RBC are studied. For the system where the additive white Gaussian noise (AWGN) term at one receiver is a degraded version of the other, which we refer to as the D-AWGN partially cooperative RBC, the capacity region is established. For the system where the AWGN term at one receiver is independent of the other, which we refer to as the AWGN partially cooperative RBC, inner and outer bounds on the capacity region are derived and are shown to be close. Furthermore, it is shown that feedback does not increase the capacity region for the degraded partially cooperative RBC, but that it improves the capacity region for the nondegraded version. In particular, feedback improves the capacity region for the AWGN partially cooperative RBC. In the second channel model being studied in the paper, the fully cooperative RBC, both users can act as relay nodes. All the results for the partially cooperative RBC are correspondingly generalized to the fully cooperative RBC. In particular, capacity regions are established for the degraded and D-AWGN fully cooperative RBCs. The capacity region is also established for the fully cooperative RBC with feedback. It is further shown that the AWGN fully cooperative RBC has a larger achievable rate region than its partially cooperative counterpart. The results illustrate that relaying and user cooperation are powerful techniques for improving the capacity of broadcast channels