Output Feedback Control for Couple-Group Consensus of Multiagent Systems

This paper deals with the couple-group consensus problem for multiagent systems via output feedback control. Both continuous- and discrete-time cases are considered. The consensus problems are converted into the stability problem of the error systems by the system transformation. We obtain two necessary and sufficient conditions of couple-group consensus in different forms for each case. Two different algorithms are used to design the control gains for continuous- and discrete-time case, respectively. Finally, simulation examples are given to show the effectiveness of the proposed results

Trustnet: a Trust and Reputation Management System in Distributed Environments

With emerging Internet-scale open content and resource sharing, social networks, and complex cyber-physical systems, trust issues become prominent. Despite their rigorous foundations, conventional network security theories and mechanisms are inadequate at addressing such loosely-defined security issues in decentralized open environments.In this dissertation, we propose a trust and reputation management system architecture and protocols (TrustNet), aimed to define and promote trust as a first-class system parameter on par with communication, computation, and storage performance metrics. To achieve such a breakthrough, we need a fundamentally new design paradigm to seamlessly integrate trust into system design. Our TrustNet initiative represents a bold effort to approach this ultimate goal. TrustNet is built on the top of underlying P2P and mobile ad hoc network layer and provides trust services to higher level applications and middleware. Following the TrustNet architecture, we design, implement, and analyze trust rating, trust aggregation, and trust management strategies. Especially, we propose three trust dissemination protocols and algorithms to meet the urgent needs and explicitly define and formulate end-to-end trust. We formulate trust management problems and propose the H-Trust, VectorTrust, and cTrust scheme to handle trust establishment and aggregation issues. We model trust relations as a trust graph in distributed environment to enhance accuracy and efficiency of trust establishment among peers. Leveraging the distributed Bellman-Ford algorithm, stochastic Markov chain process and H-Index algorithm for fast and lightweight aggregation of trust scores, our scheme are decentralized and self-configurable trust aggregation schemes.To evaluate TrustNet management strategies, we simulated our proposed protocols in both unstructured P2P network and mobile ad hoc network to analyze and simulate trust relationships. We use software generated data as well as real world data sets. Particularly, the student contact patterns on the NUS campus is used as our trust communication model. The simulation results demonstrate the features of trust relationship dissemination in real environments and the efficiency, accuracy, scalability and robustness of the TrustNet system.Computer Science Departmen

Research on dynamic behaviors of wheel loaders with different layout of hydropneumatic suspension

The traditional wheel loader is built without any axle suspension and experiences severe vibration. Three different layouts of hydropneumatic suspension, namely, unconnected strut (UCS), interconnected in roll plane (IC-R) and interconnected in roll and pitch plane (IC-RP), are installed on the wheel loader to improve ride comfort. This study mainly focuses on the damping effect of different layouts of suspensions and investigates whether the suspensions will affect the driving and operation stability of the wheel loader. The multibody model of the wheel loader with hydropneumatic suspension is developed by RecurDyn in co-simulation with MATLAB/Simulink. Detailed analysis was performed as the wheel loader was traveling on a C-class road, turning on a flat road, and scooping and unloading crushed rocks. Results showed that (1) the three layouts of suspensions can greatly reduce the vector sum of weighted acceleration; (2) the UCS suspension affects both the driving and operation stability of the wheel loader, and the IC-R suspension affects the operation stability when the wheel loader scoops and unloads crushed rocks, (3) the IC-RP suspension with anti-roll and anti-pitch functions has little effect on the driving and operation stability of the wheel loader

Crowdsourcing contests to facilitate community engagement in HIV cure research: a qualitative evaluation of facilitators and barriers of participation.

BACKGROUND: As HIV cure research advances, there is an increasing need for community engagement in health research, especially in low- and middle-income countries with ongoing clinical trials. Crowdsourcing contests provide an innovative bottom-up way to solicit community feedback on clinical trials in order to enhance community engagement. The objective of this study was to identify facilitators and barriers to participating in crowdsourcing contests about HIV cure research in a city with ongoing HIV cure clinical trials. METHODS: We conducted in-depth interviews to evaluate facilitators and barriers to participating in crowdsourcing contests in Guangzhou, China. Contests included the following activities: organizing a call for entries, promoting the call, evaluating entries, celebrating exceptional entries, and sharing entries. We interviewed 31 individuals, including nine HIV cure clinical trial participants, 17 contest participants, and five contest organizers. Our sample included men who have sex with men (20), people living with HIV (14), and people who inject drugs (5). We audio-recorded, transcribed, and thematically analyzed the data using inductive and deductive coding techniques. RESULTS: Facilitators of crowdsourcing contest participation included responsiveness to lived experiences, strong community interest in HIV research, and community trust in medical professionals and related groups. Contests had more participants if they responded to the lived experiences, challenges, and opportunities of living with HIV in China. Strong community interest in HIV research helped to drive the formulation and execution of HIV cure contests, building support and momentum for these activities. Finally, participant trust in medical professionals and related groups (community-based organizations and contest organizers) further strengthened the ties between community members and researchers. Barriers to participating in crowdsourcing contests included persistent HIV stigma and myths about HIV. Stigma associated with discussing HIV made promotion difficult in certain contexts (e.g., city squares and schools). Myths and misperceptions about HIV science confused participants. CONCLUSIONS: Our data identified facilitators and barriers of participation in HIV cure crowdsourcing contests in China. Our findings could complement existing HIV community engagement strategies and help to design HIV contests for community engagement in other settings, particularly in low- and middle-income countries

A large aperture reflective wave-plate for high-intensity short-pulse laser experiments

We report on a reflective wave-plate system utilizing phase-shifting mirrors (PSM) for a continuous variation of elliptical polarization without changing the beam position and direction. The scalability of multilayer optics to large apertures and the suitability for high-intensity broad-bandwidth laser beams make reflective wave-plates an ideal tool for experiments on relativistic laser-plasma interaction. Our measurements confirm the preservation of the pulse duration and spectrum when a 30-fs Ti:Sapphire laser beam passes the system

Nivolumab in Advanced Hepatocellular Carcinoma: Safety Profile and Select Treatment-Related Adverse Events From the CheckMate 040 Study.

BACKGROUND: CheckMate 040 assessed the efficacy and safety of nivolumab in patients with advanced hepatocellular carcinoma (HCC). Understanding the safety profile of nivolumab is needed to support the management of treatment-related adverse events (TRAEs). This analysis assessed the safety of nivolumab monotherapy in the phase I/II, open-label CheckMate 040 study. MATERIALS AND METHODS: Select TRAEs (sTRAEs; TRAEs with potential immunologic etiology requiring more frequent monitoring) occurring between first dose and 30 days after last dose were analyzed in patients in the dose-escalation and -expansion phases. Time to onset (TTO), time to resolution (TTR), and recurrence of sTRAEs were assessed, and the outcome of treatment with immune-modulating medication (IMM) was evaluated. RESULTS: The analysis included 262 patients. The most common sTRAE was skin (35.5%), followed by gastrointestinal (14.5%) and hepatic (14.1%) events; the majority were grade 1/2, with 10.7% of patients experiencing grade 3/4 events. One patient had grade 5 pneumonitis. Median (range) TTO ranged from 3.6 (0.1-59.9) weeks for skin sTRAEs to 47.6 (47.1-48.0) weeks for renal sTRAEs. Overall, 68% of sTRAEs resolved, with median (range) TTR ranging from 3.7 (0.1-123.3+) weeks for gastrointestinal sTRAEs to 28.4 (0.1-79.1) weeks for endocrine sTRAEs. Most gastrointestinal and all hepatic events resolved with treatment in accordance with established toxicity management algorithms. In 57 patients (40%), sTRAEs were managed with IMM. Reoccurrence of sTRAEs was uncommon following rechallenge with nivolumab. CONCLUSION: Nivolumab demonstrated a manageable safety profile in this analysis of patients with advanced HCC. A majority of sTRAEs resolved with treatment. IMPLICATIONS FOR PRACTICE: Nivolumab is a viable treatment option for patients with previously treated advanced hepatocellular carcinoma as it has demonstrated durable tumor responses and promising survival. Nivolumab has a manageable safety profile. The most common select treatment-related adverse events (sTRAEs) in this analysis were skin related (35%). Gastrointestinal and hepatic sTRAEs were observed in approximately 14% of patients. The majority of sTRAEs resolved (68%). Safety events are easier to manage if addressed early. Patient education on signs and symptoms to watch out for and the importance of early reporting and consultation should be emphasized