This paper designs distributed Nash equilibrium seeking strategies for heterogeneous dynamic cyber-physical systems.In particular, we are concerned with parametric uncertainties in the control channel of the players. ...This paper designs distributed Nash equilibrium seeking strategies for heterogeneous dynamic cyber-physical systems.In particular, we are concerned with parametric uncertainties in the control channel of the players. Moreover, the weights on communication links can be compromised by time-varying uncertainties, which can result from possibly malicious attacks,faults and disturbances. To deal with the unavailability of measurement of optimization errors, an output observer is constructed,based on which adaptive laws are designed to compensate for physical uncertainties. With adaptive laws, a new distributed Nash equilibrium seeking strategy is designed by further integrating consensus protocols and gradient search algorithms.Moreover, to further accommodate compromised communication weights resulting from cyber-uncertainties, the coupling strengths of the consensus module are designed to be adaptive. As a byproduct, the coupling strengths are independent of any global information. With theoretical investigations, it is proven that the proposed strategies are resilient to these uncertainties and players' actions are convergent to the Nash equilibrium. Simulation examples are given to numerically validate the effectiveness of the proposed strategies.展开更多
Starting as a maxim for academicians in ancient China,“seeking truth from facts”has evolved into a fundamental guiding principle of the Communist Party of China.THE adage“实事求是(shi shi qiu shi),”which means“se...Starting as a maxim for academicians in ancient China,“seeking truth from facts”has evolved into a fundamental guiding principle of the Communist Party of China.THE adage“实事求是(shi shi qiu shi),”which means“seeking truth from facts,”can be traced back to a chapter about Liu De,son of Western Han(206 B.C.-24 A.D.)Emperor Liu Qi,in the first-century classic the Book of Han.展开更多
This study investigated the relationship between social anxiety and problematic Internet use in college students,and how it is moderated by attitudes toward seeking professional psychological help.Participants were 14...This study investigated the relationship between social anxiety and problematic Internet use in college students,and how it is moderated by attitudes toward seeking professional psychological help.Participants were 1451 Chinese college students(female=60.2%;mean age=19.85 years,SD=1.89 years).They completed the Interaction Anxiousness Scale,the Attitudes Toward Seeking Professional Psychological Help Scale-Short Form,and the Problematic Internet Use Scale.The results revealed that college students with higher social anxiety reported greater severity of problematic Internet use.Moreover,students with negative attitudes toward seeking professional psychological help also reported greater severity of problematic Internet use.Notably,attitudes toward seeking professional psychological help moderated the relationship between social anxiety and problematic Internet use in college student,such that the relationship was weakened when attitudes toward seeking professional psychological help was positive.These findings suggest a need for student development and support programs for promoting openness to seeking professional psychological help if with problematic Internet use from social anxiety.展开更多
This paper is concerned with distributed Nash equi librium seeking strategies under quantized communication. In the proposed seeking strategy, a projection operator is synthesized with a gradient search method to achi...This paper is concerned with distributed Nash equi librium seeking strategies under quantized communication. In the proposed seeking strategy, a projection operator is synthesized with a gradient search method to achieve the optimization o players' objective functions while restricting their actions within required non-empty, convex and compact domains. In addition, a leader-following consensus protocol, in which quantized informa tion flows are utilized, is employed for information sharing among players. More specifically, logarithmic quantizers and uniform quantizers are investigated under both undirected and connected communication graphs and strongly connected digraphs, respec tively. Through Lyapunov stability analysis, it is shown that play ers' actions can be steered to a neighborhood of the Nash equilib rium with logarithmic and uniform quantizers, and the quanti fied convergence error depends on the parameter of the quan tizer for both undirected and directed cases. A numerical exam ple is given to verify the theoretical results.展开更多
Dear Editor,The distributed generalized-Nash-equilibrium(GNE)seeking in noncooperative games with nonconvexity is the topic of this letter.Inspired by the sequential quadratic programming(SQP)method,a multi-timescale ...Dear Editor,The distributed generalized-Nash-equilibrium(GNE)seeking in noncooperative games with nonconvexity is the topic of this letter.Inspired by the sequential quadratic programming(SQP)method,a multi-timescale multi-agent system(MAS)is developed,and its convergence to a critical point of the game is proven.To illustrate the qualities and efficacy of the theoretical findings,a numerical example is elaborated.展开更多
Dear Editor,This letter is concerned with prescribed-time Nash equilibrium(PTNE)seeking problem in a pursuit-evasion game(PEG)involving agents with second-order dynamics.In order to achieve the prior-given and user-de...Dear Editor,This letter is concerned with prescribed-time Nash equilibrium(PTNE)seeking problem in a pursuit-evasion game(PEG)involving agents with second-order dynamics.In order to achieve the prior-given and user-defined convergence time for the PEG,a PTNE seeking algorithm has been developed to facilitate collaboration among multiple pursuers for capturing the evader without the need for any global information.Then,it is theoretically proved that the prescribedtime convergence of the designed algorithm for achieving Nash equilibrium of PEG.Eventually,the effectiveness of the PTNE method was validated by numerical simulation results.A PEG consists of two groups of agents:evaders and pursuers.The pursuers aim to capture the evaders through cooperative efforts,while the evaders strive to evade capture.PEG is a classic noncooperative game.It has attracted plenty of attention due to its wide application scenarios,such as smart grids[1],formation control[2],[3],and spacecraft rendezvous[4].It is noteworthy that most previous research on seeking the Nash equilibrium of the game,where no agent has an incentive to change its actions,has focused on asymptotic and exponential convergence[5]-[7].展开更多
Dear Editor,This letter examines the fixed-time stability of the Nash equilibrium(NE)in non-cooperative games.We propose a consensus-based NE seeking algorithm for situations where players do not have perfect informat...Dear Editor,This letter examines the fixed-time stability of the Nash equilibrium(NE)in non-cooperative games.We propose a consensus-based NE seeking algorithm for situations where players do not have perfect information and communicate via a topology graph.The proposed algorithm can achieve NE in a fixed time that does not depend on initial conditions and can be adjusted in advance.展开更多
Dear Editor, This letter is concerned with prescribed-time fully distributed Nash equilibrium seeking for networked games under directed graphs. An adaptive algorithm is proposed to ensure the convergence of all playe...Dear Editor, This letter is concerned with prescribed-time fully distributed Nash equilibrium seeking for networked games under directed graphs. An adaptive algorithm is proposed to ensure the convergence of all players to the Nash equilibrium without requiring any knowledge of global parameters. Moreover, it is theoretically proved that the convergence time of the proposed seeking strategy can be predefined based on practical requirements. Finally, a numerical example is presented to validate the effectiveness of the proposed method.展开更多
As the EU gears up to vote on proposed tariffs on Chinese electric vehicles(EVs),former European Central Bank chief Mario Draghi has a different perspective.Relying on China for green products might be the EU’s cheap...As the EU gears up to vote on proposed tariffs on Chinese electric vehicles(EVs),former European Central Bank chief Mario Draghi has a different perspective.Relying on China for green products might be the EU’s cheapest path to meet its climate ambitions,he told European Parliament members on September 17.Some EU members are rethinking their China strategy,seeking feasible solutions for their differences with China and more cooperation,as indicated by Spanish Prime Minister Pedro Sanchez during his visit to China.展开更多
A brand new method of automatic north seeking/sight stabilizing is introduced for usage in land fighting vehicles such as tank, etc. Some inertial devices are installed additionally on the platform along with relat...A brand new method of automatic north seeking/sight stabilizing is introduced for usage in land fighting vehicles such as tank, etc. Some inertial devices are installed additionally on the platform along with relative control circuits to make its function of North seeking possible. Double position calculation is adopted in this method, and by alignment at two sites the azimuth angle can be figured out. Also the orientation and the horizontal shifts of the gyro are simultaneously measured and compensated so as to improve the accuracy of north seeking. The system can automatically seek north when the vehicle is immobile. And the time consumption is no more than 5.5 min. Besides, the system can keep azimuth angle and provide tilt angle and pitch angle of the vehicle.展开更多
Purpose： This article reports on an experiment that tested community members＇ collaborative information seeking （CIS） behavior, with an emphasis on how community type and task difficulty can affect user behavior a...Purpose： This article reports on an experiment that tested community members＇ collaborative information seeking （CIS） behavior, with an emphasis on how community type and task difficulty can affect user behavior and user awareness in collaboration.Design/methodology/approach： We carried out a laboratory study with 18 participants in 9 pairs using an experimental CIS system. Data were collected from questionnaires, Web logs and semi-structured interviews. Descriptive statistics and two-way analysis of variance （ANOVA） were used for data analysis. Findings： Compared with non-community members, community participants had a better understanding of search tasks and were aware of the ways of completing tasks successfully. They did not depend on the information retrieval system when constructing search queries and would adopt diversified cooperation strategies. They were more likely to recommend information to their partners. However, no significant difference was found between subject- based community and interest-based community in CIS practices and user awareness in collaboration. In addition, task difficulty only influenced user preference of issuing queries and confidence of completing search tasks. Research limitations： Our work was limited by the community type we chose and the small group size, which could affect the generalizability of our findings and should be addressed in future studies. Practical implications： The study results will help inform information system designers as they design collaborative systems to facilitate social communication in the information seeking process. Originality/value： Few studies have investigated community participants＇ information seeking practices. This study provides insights into community-based CIS behavior. The findings will help us understand social interactions among community members during their information seeking process.展开更多
AIM To analyze predictors of healthcare-seeking behavior among Chinese patients with irritable bowel syndrome(IBS) and their satisfaction with medical care.METHODS Participating patients met IBS Rome Ⅲ criteria(exclu...AIM To analyze predictors of healthcare-seeking behavior among Chinese patients with irritable bowel syndrome(IBS) and their satisfaction with medical care.METHODS Participating patients met IBS Rome Ⅲ criteria(excluding those with organic diseases) and were enrolled in an IBS database in a tertiary university hospital. Participants completed IBS questionnaires in face-to-face interviews. The questionnaires covered intestinal and extra-intestinal symptoms, medical consultations, colonoscopy,medications, and self-reported response to medications during the whole disease course and in the past year. Univariate associations and multivariate logistic regression were used to identify predictors for frequent healthcareseeking behavior(≥ 3 times/year), frequent colonoscopies(≥ 2 times/year), long-term medications, and poor satisfaction with medical care.RESULTS In total, 516 patients(293 males, 223 females) were included. Participants' average age was 43.2 ± 11.8 years. Before study enrollment, 55.2% had received medical consultations for IBS symptoms. Ordinary abdominal pain/discomfort(non-defecation) was an independent predictor for healthcare-seeking behavior(OR = 2.07, 95%CI: 1.31-3.27). Frequent colonoscopies were reported by 14.7% of patients(3.1 ± 1.4 times per year). Sensation of incomplete evacuation was an independent predictor for frequent colonoscopies(OR = 2.76, 95%CI: 1.35-5.67). During the whole disease course, 89% of patients took medications for IBS symptoms, and 14.7% reported they were satisfied with medical care. Patients with anxiety were more likely to report dissatisfaction with medical care(OR = 2.08, 95%CI: 1.20-3.59). In the past year, patients with severe(OR = 1.74, 95%CI: 1.06-2.82) and persistent(OR = 1.66, 95%CI: 1.01-2.72) IBS symptoms sought medical care more frequently.CONCLUSION Chinese patients with IBS present high rates of frequent healthcare-seeking behavior, colonoscopies, and medications, and low satisfaction with medical care. Intestinal symptoms are major predictors for healthcare-seeking behavior.展开更多
Previous reports showed that decreased histone deacetylase activity significantly potentiated the rewarding effects of psychostimulants, and that encoding of the 5-HT3 receptor by the htr3a gene was related to ethanol...Previous reports showed that decreased histone deacetylase activity significantly potentiated the rewarding effects of psychostimulants, and that encoding of the 5-HT3 receptor by the htr3a gene was related to ethanol-seeking behavior. However, the effects of a histone deacetylase inhibitor on ethanol-seeking behavior and epigenetic regulation of htr3a mRNA expression after chronic ethanol exposure are not fully understood. Using quantitative reverse transcription-polymerase chain reaction and chromatin immunoprecipitation analysis, we investigated the effects of chronic ethanol exposure and its interaction with a histone deacetylase inhibitor on histone-acetylation-mediated changes in htr3a mRNA expression in the htr3a promoter region. The conditioned place preference procedure was used to evaluate ethanol-seeking behavior. Chronic exposure to ethanol effectively elicited place conditioning. In the prefrontal cortex, the acetylation of H3K9 and htr3a mRNA expression in the htr3a promoter region were significantly higher in the ethanol group than in the saline group. The histone deacetylase inhibitor sodium butyrate potentiated the effects of ethanol on htr3a mRNA expression and enhanced ethanol-induced conditioned place preferences. These results suggest that ethanol upregulates htr3a levels through mechanisms involving H3K9 acetylation, and that histone acetylation may be a therapeutic target for treating ethanol abuse.展开更多
In this paper,we consider distributed Nash equilibrium(NE)seeking in potential games over a multi-agent network,where each agent can not observe the actions of all its rivals.Based on the best response dynamics,we des...In this paper,we consider distributed Nash equilibrium(NE)seeking in potential games over a multi-agent network,where each agent can not observe the actions of all its rivals.Based on the best response dynamics,we design a distributed NE seeking algorithm by incorporating the non-smooth finite-time average tracking dynamics,where each agent only needs to know its own action and exchange information with its neighbours through a communication graph.We give a sufficient condition for the Lipschitz continuity of the best response mapping for potential games,and then prove the convergence of the proposed algorithm based on the Lyapunov theory.Numerical simulations are given to verify the resultandillustrate the effectiveness of the algorithm.展开更多
Objective:To compare perceived ill-health and health seeking behavior between two communities affected by the large Nam Theun 2 hydroelectric project in central Lao People’s Democratic Republic(PDR).Methods: Two diff...Objective:To compare perceived ill-health and health seeking behavior between two communities affected by the large Nam Theun 2 hydroelectric project in central Lao People’s Democratic Republic(PDR).Methods: Two different affected areas;Nakai plateaubeing remote,sparcely populated and mountainous,and Xe Bang Fai lowland plains,more densely populated and comparatively affluent were included.Data were obtained from two cross-sectional household-based health and socio-economic surveys.Results:We found pronounced differences in the frequency of self-reported fever,cough,headache and myalgia according to location.On the Nakai plateau,45.1%of the individuals with ill-health report(recall period;2 weeks) went to a local health volunteer compared to only 7.2%in the Xe Bang Fai area(P 【 0.001 ).In Nakai,there were disproportionately more illiterates seeking help from local health volunteers when compared to those who attended at least primary schooling(49.2%versus 17.5%,P 【0.01 ).Self-medication with antimalarials was more common in Xe Bang Fai than on Nakai(32.3%versus 7.0%,P 【 0.001).The mean amount of money spent per health consultation was US $ 1.7 in Nakai and US $ 7.2 in Xe Bang Fai.Conclusion:The observed differences in self-reported ill-health and health seeking behavior among these two Lao communities need to be considered when implementing setting-specific mitigation measures as part of the public health action plan of the Nam Theun 2 hydroelectric project.展开更多
Cervical cancer is a curable disease if diagnosed early. However, many women in Malawi seek treatment when the disease has reached inoperable stage. This study was conducted to explore factors that contribute to delay...Cervical cancer is a curable disease if diagnosed early. However, many women in Malawi seek treatment when the disease has reached inoperable stage. This study was conducted to explore factors that contribute to delay in seeking early diagnosis and treatment of cervical cancer among women in Malawi. The study was exploratory and utilized qualitative data collection and analysis method. In-depth interviews were conducted using a semi-structured interview guide on a purposive sample of 24 women who were diagnosed of cervical cancer at the gynaecological wards of Zomba and Queen Elizabeth Central Hospitals in Malawi between July and September, 2011. Thematic content analysis was used to analyze the qualitative data. Two major themes (individual and health facility) emerged from the participants’ narratives as factors that contributed to their delay in seeking early diagnosis and treatment. The individual factors included;limited knowledge on symptoms and signs and limited financial resources. The health facilities factors included;limited accessibility and unavailability of cancer screening facilities in the health centres. Results show that there is a need to strengthen the screening of cervical cancer among women in the country. In addition, there is a need to create community awareness on the signs and symptoms of cervical cancer and the merits of seeking early diagnosis and treatment.展开更多
In this work,we study a Nash equilibrium(NE)seeking problem for strongly monotone non-cooperative games with prescribed performance.Unlike general NE seeking algorithms,the proposed prescribed-performance NE seeking l...In this work,we study a Nash equilibrium(NE)seeking problem for strongly monotone non-cooperative games with prescribed performance.Unlike general NE seeking algorithms,the proposed prescribed-performance NE seeking laws ensure that the convergence error evolves within a predefined region.Thus,the settling time,convergence rate,and maximum overshoot of the algorithm can be guaranteed.First,we develop a second-order Newton-like algorithm that can guarantee prescribed performance and asymptotically converge to the NE of the game.Then,we develop a first-order gradient-based algorithm.To remove some restrictions on this first-order algorithm,we propose two discontinuous dynamical system-based algorithms using tools from non-smooth analysis and adaptive control.We study the special case in optimization problems.Then,we investigate the robustness of the algorithms.It can be proven that the proposed algorithms can guarantee asymptotic convergence to the Nash equilibrium with prescribed performance in the presence of bounded disturbances.Furthermore,we consider a second-order dynamical system solution.The simulation results verify the effectiveness and efficiency of the algorithms,in terms of their convergence rate and disturbance rejection ability.展开更多
Purpose： This study investigates how online user intention in searching health information is affected by problematic situations.Design/methodology/approach： Based on the Theory of Reasoned Action, the Technology Ac...Purpose： This study investigates how online user intention in searching health information is affected by problematic situations.Design/methodology/approach： Based on the Theory of Reasoned Action, the Technology Acceptance Model, and Sense-making theory, we propose two dimensions of problematic situations： urgency and severity of health issues being searched online. Data were collected through a questionnaire survey among 214 Wuhan University students and analyzed using hierarchical regression analysis.Findings： Perceived usefulness, perceived ease of use, and subjective norm can influence user intention to seek health information online. The urgency of problematic situations has a negative moderating effect on the relationship between perceived ease of use and user intention and the relationship between subjective norm and user intention. The severity of problematic situations has a negative moderating effect on the relationship between subjective norm and user intention.Research limitations： The respondents of the survey are limited to students in one Chinese university, so whether this study＇s results can be applied to another population or not remains to be verified. In addition, only two dimensions of problematic situations are considered in this study. Practical implications： The paper puts forward the moderating effect of problematic situations and verifies it, which is the compensation for online health information-seeking behavior research. Besides, our analyses have implications for professional design of health care systems and related consumer information searches, and improve their performance. Originality/value： Previous work has reported the effects of problematic situation on user intention to seek health information online, ignoring its influence on other factors. This empirical study extends that work to identify the influence of problematic situation when seeking intention-behavior data in two dimensions, urgency and severity.展开更多
There has been an increasing research interest in modeling,optimization and control of various multi-agent networks that have wide applications in industry,defense,security,and social areas,such as computing clusters,...There has been an increasing research interest in modeling,optimization and control of various multi-agent networks that have wide applications in industry,defense,security,and social areas,such as computing clusters,interconnected micro-grid systems,unmanned vessel swarms[1],power systems[2],multiple UAV systems[3]and sensor networks[4].For non-cooperative agents that only concern selfish profit-maximizing,the decision making problem can be modelled and solved with the help of game theory,while Nash equilibrium(NE)seeking is at the core to solve the non-cooperative multi-agent games[5-7].Distributed NE seeking methods are appealing compared with the center-based methods in large-scale networks due to its scalability,privacy protection,and adaptability.Recently,monotone operator theory is explored for distributed NE seeking,which is shown to provide an uniform framework for various algorithms in different scenarios.It has been gradually developing into a cutting-edge research field,with the prospect and necessity of future in-depth research.展开更多
AIM To investigate the effects of direct to colonoscopy pathways on information seeking behaviors and anxiety among colonoscopy-na?ve patients.METHODS Colonoscopy-na?ve patients at two tertiary care hospitals complete...AIM To investigate the effects of direct to colonoscopy pathways on information seeking behaviors and anxiety among colonoscopy-na?ve patients.METHODS Colonoscopy-na?ve patients at two tertiary care hospitals completed a survey immediately prior to their scheduled outpatient procedure and before receiving sedation.Survey items included clinical pathway(direct or consult),procedure indication(cancer screening or symptom investigation),telephone and written contact from the physician endoscopist office,information sources,and pre-procedure anxiety.Participants reported pre-procedure anxiety using a 10 point scale anchored by "very relaxed"(1) and "very nervous"(10).At least three months following the procedure,patient medical records were reviewed to determine sedative dose,procedure indications and any adverse events.The primary comparison was between the direct and consult pathways.Given the very different implications,a secondary analysis considering the patient-reported indication for the procedure(symptoms or screening).Effects of pathway(direct vs consult) were compared both within and between the screening and symptom subgroups.RESULTS Of 409 patients who completed the survey,34% followed a direct pathway.Indications for colonoscopy were similar in each group.The majority of the participants were women(58%),married(61%),and internet users(81%).The most important information source was family physicians(Direct) and specialist physicians(Consult).Use of other information sources,including the internet(20% vs 18%) and Direct family and friends(64% vs 53%),was similar in the Direct and Consult groups,respectively.Only 31% of the 81% who were internet users accessed internet health information.Most sought fundamental information such as what a colonoscopy is or why it is done.Pre-procedure anxiety did not differ between care pathways.Those undergoing colonoscopy for symptoms reported greater anxiety [mean 5.3,95%CI: 5.0-5.7(10 point Likert scale)] than those for screening colonoscopy(4.3,95%CI: 3.9-4.7).CONCLUSION Procedure indication(cancer screening or symptom investigation) was more closely associated with information seeking behaviors and pre-procedure anxiety than care pathway.展开更多
基金supported by the National Key R&D Program of China(2022ZD0119604)the National Natural Science Foundation of China(NSFC)(62173181,62222308,62221004)the Natural Science Foundation of Jiangsu Province(BK20220139)
文摘This paper designs distributed Nash equilibrium seeking strategies for heterogeneous dynamic cyber-physical systems.In particular, we are concerned with parametric uncertainties in the control channel of the players. Moreover, the weights on communication links can be compromised by time-varying uncertainties, which can result from possibly malicious attacks,faults and disturbances. To deal with the unavailability of measurement of optimization errors, an output observer is constructed,based on which adaptive laws are designed to compensate for physical uncertainties. With adaptive laws, a new distributed Nash equilibrium seeking strategy is designed by further integrating consensus protocols and gradient search algorithms.Moreover, to further accommodate compromised communication weights resulting from cyber-uncertainties, the coupling strengths of the consensus module are designed to be adaptive. As a byproduct, the coupling strengths are independent of any global information. With theoretical investigations, it is proven that the proposed strategies are resilient to these uncertainties and players' actions are convergent to the Nash equilibrium. Simulation examples are given to numerically validate the effectiveness of the proposed strategies.
文摘Starting as a maxim for academicians in ancient China,“seeking truth from facts”has evolved into a fundamental guiding principle of the Communist Party of China.THE adage“实事求是(shi shi qiu shi),”which means“seeking truth from facts,”can be traced back to a chapter about Liu De,son of Western Han(206 B.C.-24 A.D.)Emperor Liu Qi,in the first-century classic the Book of Han.
基金funded by Science and Technology Research Project of Jiangxi’Department of Education(GJJ2200929)Key Project of Guangzhou Psychological Society(2023GZPS05).
文摘This study investigated the relationship between social anxiety and problematic Internet use in college students,and how it is moderated by attitudes toward seeking professional psychological help.Participants were 1451 Chinese college students(female=60.2%;mean age=19.85 years,SD=1.89 years).They completed the Interaction Anxiousness Scale,the Attitudes Toward Seeking Professional Psychological Help Scale-Short Form,and the Problematic Internet Use Scale.The results revealed that college students with higher social anxiety reported greater severity of problematic Internet use.Moreover,students with negative attitudes toward seeking professional psychological help also reported greater severity of problematic Internet use.Notably,attitudes toward seeking professional psychological help moderated the relationship between social anxiety and problematic Internet use in college student,such that the relationship was weakened when attitudes toward seeking professional psychological help was positive.These findings suggest a need for student development and support programs for promoting openness to seeking professional psychological help if with problematic Internet use from social anxiety.
基金supported by the National Natural Science Foundation of China (NSFC)(62222308, 62173181, 62073171, 62221004)the Natural Science Foundation of Jiangsu Province (BK20200744, BK20220139)+3 种基金Jiangsu Specially-Appointed Professor (RK043STP19001)the Young Elite Scientists Sponsorship Program by CAST (2021QNRC001)1311 Talent Plan of Nanjing University of Posts and Telecommunicationsthe Fundamental Research Funds for the Central Universities (30920032203)。
文摘This paper is concerned with distributed Nash equi librium seeking strategies under quantized communication. In the proposed seeking strategy, a projection operator is synthesized with a gradient search method to achieve the optimization o players' objective functions while restricting their actions within required non-empty, convex and compact domains. In addition, a leader-following consensus protocol, in which quantized informa tion flows are utilized, is employed for information sharing among players. More specifically, logarithmic quantizers and uniform quantizers are investigated under both undirected and connected communication graphs and strongly connected digraphs, respec tively. Through Lyapunov stability analysis, it is shown that play ers' actions can be steered to a neighborhood of the Nash equilib rium with logarithmic and uniform quantizers, and the quanti fied convergence error depends on the parameter of the quan tizer for both undirected and directed cases. A numerical exam ple is given to verify the theoretical results.
基金partially supported by the National Natural Science Foundation of China(62173308)the Natural Science Foundation of Zhejiang Province of China(LR20F030001)+3 种基金the Jinhua Science and Technology Project(2022-1-042)University of Macao(MYRG2022-00108-FST,MYRG-CRG202200010-ICMS)the Science and Technology Development Fund,Macao S.A.R(0036/2021/AGJ)Chinese Guangdong’s S&T project(2022A0505020028)。
文摘Dear Editor,The distributed generalized-Nash-equilibrium(GNE)seeking in noncooperative games with nonconvexity is the topic of this letter.Inspired by the sequential quadratic programming(SQP)method,a multi-timescale multi-agent system(MAS)is developed,and its convergence to a critical point of the game is proven.To illustrate the qualities and efficacy of the theoretical findings,a numerical example is elaborated.
基金supported in part by the Natural Science Foundation of Jiangsu Province of China(BK20231417,BK20210214)the National Natural Science Foundation of China(62273094,62203114)the“Zhishan”Scholars Programs of Southeast University.
文摘Dear Editor,This letter is concerned with prescribed-time Nash equilibrium(PTNE)seeking problem in a pursuit-evasion game(PEG)involving agents with second-order dynamics.In order to achieve the prior-given and user-defined convergence time for the PEG,a PTNE seeking algorithm has been developed to facilitate collaboration among multiple pursuers for capturing the evader without the need for any global information.Then,it is theoretically proved that the prescribedtime convergence of the designed algorithm for achieving Nash equilibrium of PEG.Eventually,the effectiveness of the PTNE method was validated by numerical simulation results.A PEG consists of two groups of agents:evaders and pursuers.The pursuers aim to capture the evaders through cooperative efforts,while the evaders strive to evade capture.PEG is a classic noncooperative game.It has attracted plenty of attention due to its wide application scenarios,such as smart grids[1],formation control[2],[3],and spacecraft rendezvous[4].It is noteworthy that most previous research on seeking the Nash equilibrium of the game,where no agent has an incentive to change its actions,has focused on asymptotic and exponential convergence[5]-[7].
基金supported by the National Natural Science Foundation of China(62373107,61921004,62303009)the Natural Science Foundation of Jiangsu Province of China(BK20202006)the“Zhishan”Scholars Programs of Southeast University。
文摘Dear Editor,This letter examines the fixed-time stability of the Nash equilibrium(NE)in non-cooperative games.We propose a consensus-based NE seeking algorithm for situations where players do not have perfect information and communicate via a topology graph.The proposed algorithm can achieve NE in a fixed time that does not depend on initial conditions and can be adjusted in advance.
基金supported by the National Natural Science Foundation of China (NSFC) (62073171)the Natural Science Foundation of Jiangsu Province (BK20200744)。
文摘Dear Editor, This letter is concerned with prescribed-time fully distributed Nash equilibrium seeking for networked games under directed graphs. An adaptive algorithm is proposed to ensure the convergence of all players to the Nash equilibrium without requiring any knowledge of global parameters. Moreover, it is theoretically proved that the convergence time of the proposed seeking strategy can be predefined based on practical requirements. Finally, a numerical example is presented to validate the effectiveness of the proposed method.
文摘As the EU gears up to vote on proposed tariffs on Chinese electric vehicles(EVs),former European Central Bank chief Mario Draghi has a different perspective.Relying on China for green products might be the EU’s cheapest path to meet its climate ambitions,he told European Parliament members on September 17.Some EU members are rethinking their China strategy,seeking feasible solutions for their differences with China and more cooperation,as indicated by Spanish Prime Minister Pedro Sanchez during his visit to China.
文摘A brand new method of automatic north seeking/sight stabilizing is introduced for usage in land fighting vehicles such as tank, etc. Some inertial devices are installed additionally on the platform along with relative control circuits to make its function of North seeking possible. Double position calculation is adopted in this method, and by alignment at two sites the azimuth angle can be figured out. Also the orientation and the horizontal shifts of the gyro are simultaneously measured and compensated so as to improve the accuracy of north seeking. The system can automatically seek north when the vehicle is immobile. And the time consumption is no more than 5.5 min. Besides, the system can keep azimuth angle and provide tilt angle and pitch angle of the vehicle.
基金supported by the National Program for Support of Top-notch Young Professionals
文摘Purpose： This article reports on an experiment that tested community members＇ collaborative information seeking （CIS） behavior, with an emphasis on how community type and task difficulty can affect user behavior and user awareness in collaboration.Design/methodology/approach： We carried out a laboratory study with 18 participants in 9 pairs using an experimental CIS system. Data were collected from questionnaires, Web logs and semi-structured interviews. Descriptive statistics and two-way analysis of variance （ANOVA） were used for data analysis. Findings： Compared with non-community members, community participants had a better understanding of search tasks and were aware of the ways of completing tasks successfully. They did not depend on the information retrieval system when constructing search queries and would adopt diversified cooperation strategies. They were more likely to recommend information to their partners. However, no significant difference was found between subject- based community and interest-based community in CIS practices and user awareness in collaboration. In addition, task difficulty only influenced user preference of issuing queries and confidence of completing search tasks. Research limitations： Our work was limited by the community type we chose and the small group size, which could affect the generalizability of our findings and should be addressed in future studies. Practical implications： The study results will help inform information system designers as they design collaborative systems to facilitate social communication in the information seeking process. Originality/value： Few studies have investigated community participants＇ information seeking practices. This study provides insights into community-based CIS behavior. The findings will help us understand social interactions among community members during their information seeking process.
基金Supported by the Program of International S&T Cooperation,No.2014DFA31850Project of the National Key Technologies R&D Program in the 11th Five Year Plan period,No.2007BAI04B01National High-tech R&D Program("863"Program,2010AA023007),China
文摘AIM To analyze predictors of healthcare-seeking behavior among Chinese patients with irritable bowel syndrome(IBS) and their satisfaction with medical care.METHODS Participating patients met IBS Rome Ⅲ criteria(excluding those with organic diseases) and were enrolled in an IBS database in a tertiary university hospital. Participants completed IBS questionnaires in face-to-face interviews. The questionnaires covered intestinal and extra-intestinal symptoms, medical consultations, colonoscopy,medications, and self-reported response to medications during the whole disease course and in the past year. Univariate associations and multivariate logistic regression were used to identify predictors for frequent healthcareseeking behavior(≥ 3 times/year), frequent colonoscopies(≥ 2 times/year), long-term medications, and poor satisfaction with medical care.RESULTS In total, 516 patients(293 males, 223 females) were included. Participants' average age was 43.2 ± 11.8 years. Before study enrollment, 55.2% had received medical consultations for IBS symptoms. Ordinary abdominal pain/discomfort(non-defecation) was an independent predictor for healthcare-seeking behavior(OR = 2.07, 95%CI: 1.31-3.27). Frequent colonoscopies were reported by 14.7% of patients(3.1 ± 1.4 times per year). Sensation of incomplete evacuation was an independent predictor for frequent colonoscopies(OR = 2.76, 95%CI: 1.35-5.67). During the whole disease course, 89% of patients took medications for IBS symptoms, and 14.7% reported they were satisfied with medical care. Patients with anxiety were more likely to report dissatisfaction with medical care(OR = 2.08, 95%CI: 1.20-3.59). In the past year, patients with severe(OR = 1.74, 95%CI: 1.06-2.82) and persistent(OR = 1.66, 95%CI: 1.01-2.72) IBS symptoms sought medical care more frequently.CONCLUSION Chinese patients with IBS present high rates of frequent healthcare-seeking behavior, colonoscopies, and medications, and low satisfaction with medical care. Intestinal symptoms are major predictors for healthcare-seeking behavior.
基金supported by the National Key Basic Research and Development Program(NKBRDP)of China(No.2009CB522000)the National Natural Science Foundation of China(No.30971050)+1 种基金the State Key Program of the National Natural Science of China(No.81130020)the Key Program on Basic Science of Henan Science and Technology Department(No.094200510005)
文摘Previous reports showed that decreased histone deacetylase activity significantly potentiated the rewarding effects of psychostimulants, and that encoding of the 5-HT3 receptor by the htr3a gene was related to ethanol-seeking behavior. However, the effects of a histone deacetylase inhibitor on ethanol-seeking behavior and epigenetic regulation of htr3a mRNA expression after chronic ethanol exposure are not fully understood. Using quantitative reverse transcription-polymerase chain reaction and chromatin immunoprecipitation analysis, we investigated the effects of chronic ethanol exposure and its interaction with a histone deacetylase inhibitor on histone-acetylation-mediated changes in htr3a mRNA expression in the htr3a promoter region. The conditioned place preference procedure was used to evaluate ethanol-seeking behavior. Chronic exposure to ethanol effectively elicited place conditioning. In the prefrontal cortex, the acetylation of H3K9 and htr3a mRNA expression in the htr3a promoter region were significantly higher in the ethanol group than in the saline group. The histone deacetylase inhibitor sodium butyrate potentiated the effects of ethanol on htr3a mRNA expression and enhanced ethanol-induced conditioned place preferences. These results suggest that ethanol upregulates htr3a levels through mechanisms involving H3K9 acetylation, and that histone acetylation may be a therapeutic target for treating ethanol abuse.
基金This work was supported by the Shanghai Sailing Program(No.20YF1453000)the Fundamental Research Funds for the Central Universities(No.22120200048).
文摘In this paper,we consider distributed Nash equilibrium(NE)seeking in potential games over a multi-agent network,where each agent can not observe the actions of all its rivals.Based on the best response dynamics,we design a distributed NE seeking algorithm by incorporating the non-smooth finite-time average tracking dynamics,where each agent only needs to know its own action and exchange information with its neighbours through a communication graph.We give a sufficient condition for the Lipschitz continuity of the best response mapping for potential games,and then prove the convergence of the proposed algorithm based on the Lyapunov theory.Numerical simulations are given to verify the resultandillustrate the effectiveness of the algorithm.
基金financial support was granted by the Swiss National Science Foundationthe Swiss Agency for Development and Cooperation(projects no.3270B0 - 110020 to SS and PO and no.PPOOB - 102883 to TEE and JU)
文摘Objective:To compare perceived ill-health and health seeking behavior between two communities affected by the large Nam Theun 2 hydroelectric project in central Lao People’s Democratic Republic(PDR).Methods: Two different affected areas;Nakai plateaubeing remote,sparcely populated and mountainous,and Xe Bang Fai lowland plains,more densely populated and comparatively affluent were included.Data were obtained from two cross-sectional household-based health and socio-economic surveys.Results:We found pronounced differences in the frequency of self-reported fever,cough,headache and myalgia according to location.On the Nakai plateau,45.1%of the individuals with ill-health report(recall period;2 weeks) went to a local health volunteer compared to only 7.2%in the Xe Bang Fai area(P 【 0.001 ).In Nakai,there were disproportionately more illiterates seeking help from local health volunteers when compared to those who attended at least primary schooling(49.2%versus 17.5%,P 【0.01 ).Self-medication with antimalarials was more common in Xe Bang Fai than on Nakai(32.3%versus 7.0%,P 【 0.001).The mean amount of money spent per health consultation was US $ 1.7 in Nakai and US $ 7.2 in Xe Bang Fai.Conclusion:The observed differences in self-reported ill-health and health seeking behavior among these two Lao communities need to be considered when implementing setting-specific mitigation measures as part of the public health action plan of the Nam Theun 2 hydroelectric project.
文摘Cervical cancer is a curable disease if diagnosed early. However, many women in Malawi seek treatment when the disease has reached inoperable stage. This study was conducted to explore factors that contribute to delay in seeking early diagnosis and treatment of cervical cancer among women in Malawi. The study was exploratory and utilized qualitative data collection and analysis method. In-depth interviews were conducted using a semi-structured interview guide on a purposive sample of 24 women who were diagnosed of cervical cancer at the gynaecological wards of Zomba and Queen Elizabeth Central Hospitals in Malawi between July and September, 2011. Thematic content analysis was used to analyze the qualitative data. Two major themes (individual and health facility) emerged from the participants’ narratives as factors that contributed to their delay in seeking early diagnosis and treatment. The individual factors included;limited knowledge on symptoms and signs and limited financial resources. The health facilities factors included;limited accessibility and unavailability of cancer screening facilities in the health centres. Results show that there is a need to strengthen the screening of cervical cancer among women in the country. In addition, there is a need to create community awareness on the signs and symptoms of cervical cancer and the merits of seeking early diagnosis and treatment.
基金supported by the RIE2020 Industry Alignment Fund-Industry Collaboration Projects(IAF-ICP)Funding Initiative,as well as cash and in-kind contribution from the industry partner(s).
文摘In this work,we study a Nash equilibrium(NE)seeking problem for strongly monotone non-cooperative games with prescribed performance.Unlike general NE seeking algorithms,the proposed prescribed-performance NE seeking laws ensure that the convergence error evolves within a predefined region.Thus,the settling time,convergence rate,and maximum overshoot of the algorithm can be guaranteed.First,we develop a second-order Newton-like algorithm that can guarantee prescribed performance and asymptotically converge to the NE of the game.Then,we develop a first-order gradient-based algorithm.To remove some restrictions on this first-order algorithm,we propose two discontinuous dynamical system-based algorithms using tools from non-smooth analysis and adaptive control.We study the special case in optimization problems.Then,we investigate the robustness of the algorithms.It can be proven that the proposed algorithms can guarantee asymptotic convergence to the Nash equilibrium with prescribed performance in the presence of bounded disturbances.Furthermore,we consider a second-order dynamical system solution.The simulation results verify the effectiveness and efficiency of the algorithms,in terms of their convergence rate and disturbance rejection ability.
基金supported in part by the Key Projects of Philosophy and Social Sciences Research supported by the Ministry of Education of the People’s Republic of China(Grant No.:15JJD870001)Luo Jia Youth Scholar of Wuhan University
文摘Purpose： This study investigates how online user intention in searching health information is affected by problematic situations.Design/methodology/approach： Based on the Theory of Reasoned Action, the Technology Acceptance Model, and Sense-making theory, we propose two dimensions of problematic situations： urgency and severity of health issues being searched online. Data were collected through a questionnaire survey among 214 Wuhan University students and analyzed using hierarchical regression analysis.Findings： Perceived usefulness, perceived ease of use, and subjective norm can influence user intention to seek health information online. The urgency of problematic situations has a negative moderating effect on the relationship between perceived ease of use and user intention and the relationship between subjective norm and user intention. The severity of problematic situations has a negative moderating effect on the relationship between subjective norm and user intention.Research limitations： The respondents of the survey are limited to students in one Chinese university, so whether this study＇s results can be applied to another population or not remains to be verified. In addition, only two dimensions of problematic situations are considered in this study. Practical implications： The paper puts forward the moderating effect of problematic situations and verifies it, which is the compensation for online health information-seeking behavior research. Besides, our analyses have implications for professional design of health care systems and related consumer information searches, and improve their performance. Originality/value： Previous work has reported the effects of problematic situation on user intention to seek health information online, ignoring its influence on other factors. This empirical study extends that work to identify the influence of problematic situation when seeking intention-behavior data in two dimensions, urgency and severity.
基金This work was supported by the Shanghai Sailing Program(No.20YF1453000)the Fundamental Research Funds for the Central Universities(No.22120200048).
文摘There has been an increasing research interest in modeling,optimization and control of various multi-agent networks that have wide applications in industry,defense,security,and social areas,such as computing clusters,interconnected micro-grid systems,unmanned vessel swarms[1],power systems[2],multiple UAV systems[3]and sensor networks[4].For non-cooperative agents that only concern selfish profit-maximizing,the decision making problem can be modelled and solved with the help of game theory,while Nash equilibrium(NE)seeking is at the core to solve the non-cooperative multi-agent games[5-7].Distributed NE seeking methods are appealing compared with the center-based methods in large-scale networks due to its scalability,privacy protection,and adaptability.Recently,monotone operator theory is explored for distributed NE seeking,which is shown to provide an uniform framework for various algorithms in different scenarios.It has been gradually developing into a cutting-edge research field,with the prospect and necessity of future in-depth research.
基金Health Sciences Centre Medical Staff Council Resident Research Award
文摘AIM To investigate the effects of direct to colonoscopy pathways on information seeking behaviors and anxiety among colonoscopy-na?ve patients.METHODS Colonoscopy-na?ve patients at two tertiary care hospitals completed a survey immediately prior to their scheduled outpatient procedure and before receiving sedation.Survey items included clinical pathway(direct or consult),procedure indication(cancer screening or symptom investigation),telephone and written contact from the physician endoscopist office,information sources,and pre-procedure anxiety.Participants reported pre-procedure anxiety using a 10 point scale anchored by "very relaxed"(1) and "very nervous"(10).At least three months following the procedure,patient medical records were reviewed to determine sedative dose,procedure indications and any adverse events.The primary comparison was between the direct and consult pathways.Given the very different implications,a secondary analysis considering the patient-reported indication for the procedure(symptoms or screening).Effects of pathway(direct vs consult) were compared both within and between the screening and symptom subgroups.RESULTS Of 409 patients who completed the survey,34% followed a direct pathway.Indications for colonoscopy were similar in each group.The majority of the participants were women(58%),married(61%),and internet users(81%).The most important information source was family physicians(Direct) and specialist physicians(Consult).Use of other information sources,including the internet(20% vs 18%) and Direct family and friends(64% vs 53%),was similar in the Direct and Consult groups,respectively.Only 31% of the 81% who were internet users accessed internet health information.Most sought fundamental information such as what a colonoscopy is or why it is done.Pre-procedure anxiety did not differ between care pathways.Those undergoing colonoscopy for symptoms reported greater anxiety [mean 5.3,95%CI: 5.0-5.7(10 point Likert scale)] than those for screening colonoscopy(4.3,95%CI: 3.9-4.7).CONCLUSION Procedure indication(cancer screening or symptom investigation) was more closely associated with information seeking behaviors and pre-procedure anxiety than care pathway.
