493 research outputs found
COURSE-KEEPING CONTROL FOR DIRECTIONALLY UNSTABLE LARGE TANKERS USING THE MIRROR-MAPPING TECHNIQUE
This study examines the course-keeping control of directionally unstable large oil tankers involving a pole in the right half plane. Treated as an unstable plant in control engineering, tankers are theoretically and experimentally investigated during the controller design process. First, the unstable plant is mirror-mapped to its corresponding stable minimum phase plant using the mirror-mapping technique, which enables an easy controller design. Then, a linear proportional-differential and a first-order filter controller is designed based on the closed-loop gain shaping algorithm, which requires only one controller parameter to be properly selected based on the system’s characteristics. Numerical simulation results confirmed that the designed controller can successfully stabilise an unstable plant subjected to external wind and wave disturbances. The controller designed with the proposed method is suitable for course-keeping control of directionally unstable large tankers. The controller design method is simple with an uncomplicated structure that can easily be implemented in engineering endeavours. Moreover, the rudder motion is small and soft
Personal Involvement Moderates Message Framing Effects on Food Safety Education among Medical University Students in Chongqing, China.
This study explored whether the efficacy of food safety education interventions can be increased by message framing among medical university students, and demonstrated the role of personal involvement within the message recipient in moderating framed effects. A cross-sectional study of food safety message framing was conducted among medical university students (randomly selected 1353 participants). An online self-administered questionnaire was used to collect information. Wilcoxon rank-sum test and Ordered multivariate logistic regression were utilised in the data analyses. The present study showed significant differences in acceptance between the gain- and loss-framed groups ( < 0.001). Participants with higher personal involvement had higher acceptance than those with low personal involvement in gain- and loss-framed message models ( < 0.001). The acceptance of participants who were concerned about their health condition was higher than those who were neutral regarding their health condition ( < 0.001) and participants who suffered a food safety incident had higher acceptance than those who did not ( < 0.05). This study portrayed the selection preference of message framing on food safety education among medical university students in southwest China. Participants exposed to loss-framed messages had higher message acceptance than those exposed to gain-framed messages. Personal involvement may affect the food safety message framing. Public health advocates and professionals can use framed messages as a strategy to enhance intervention efficacy in the process of food safety education
Learning from supervisor negative gossip: the reflective learning process and performance outcome of employee receivers
Workplace gossip is generally viewed as a deviant behavior that negatively affects the work outcomes of employees. However, we argue that this negative view is incomplete. Drawing on the cultural learning perspective of gossip and social learning theory, we examine how the job performance of employee receivers benefits from supervisor negative gossip through reflective learning. On the basis of multi-source, cross-sectional designs, Studies 1 and 2 consistently find that supervisor negative gossip facilitates employee receiver reflective learning and subsequent job performance when controlling for two sets of theory-relevant variables. Study 3, which has a multi-source, cross-lagged panel design, provides further evidence of the directional relationship from supervisor negative gossip to employee receiver job performance through reflective learning. The findings of the three separate field studies support the positive effect of supervisor negative gossip on employee receivers from a learning perspective. We discuss the theoretical and practical implications of these findings in terms of how employee receiver job performance can benefit from workplace negative gossip
Effects of Goal-Framed Messages on Mental Health Education Among Medical University Students: Moderating Role of Personal Involvement.
Mental health problem among university students is an emerging public health issue, and mental health education has always been the focus of attention for universities. However, limited attention has been paid to the effect of students' acceptance of health messages. Previous studies have found that message framing plays a key role in the process of responding to health-promoting messages. In this backdrop, the study aimed to examine the effects of goal-framed messages on mental health education among medical university students and investigate the moderating role of personal involvement. A cross-sectional study was conducted on medical university students. An online self-administered questionnaire was used to collect data. Wilcoxon rank-sum test and ordinal logistic regression were used for data analysis. Results showed significant differences in message acceptance between the gain- and loss-framed groups ( < 0.001). Participants with high personal involvement had higher message acceptance than those with low personal involvement in gain- and loss-framed message models ( < 0.05). Specifically, participants who related to roommates with high intimacy had higher message acceptance than those who related to roommates generally ( < 0.05). Participants who were concerned about their health condition had higher message acceptance than those who were neutral about their health condition ( < 0.001). Evidence of advantages of gain- over loss-framed messages on mental health among medical university students was found. The hypothesis that personal involvement with a health issue affects the acceptance of message framing was supported. Public health advocates can use framed message as a strategy to improve the efficacy of intervention in mental health education
Diffusion-based 3D Object Detection with Random Boxes
3D object detection is an essential task for achieving autonomous driving.
Existing anchor-based detection methods rely on empirical heuristics setting of
anchors, which makes the algorithms lack elegance. In recent years, we have
witnessed the rise of several generative models, among which diffusion models
show great potential for learning the transformation of two distributions. Our
proposed Diff3Det migrates the diffusion model to proposal generation for 3D
object detection by considering the detection boxes as generative targets.
During training, the object boxes diffuse from the ground truth boxes to the
Gaussian distribution, and the decoder learns to reverse this noise process. In
the inference stage, the model progressively refines a set of random boxes to
the prediction results. We provide detailed experiments on the KITTI benchmark
and achieve promising performance compared to classical anchor-based 3D
detection methods.Comment: Accepted by PRCV 202
Numerical predictions of wind induced buffeting vibration for structures by a developed pseudo excitation method
A numerical analysis method for wind-induced response of structures is presented which is based on the pseudo-excitation method to significantly reduce the computational complexity while preserving accuracy. Original pseudo-excitation method was developed suitable for adoption by combining an effective computational fluid dynamic method which can be used to replace wind tunnel tests when finding important aerodynamic parameters. Two problems investigated are gust responses of a composite wing and buffeting vibration responses of the Tsing Ma Bridge. Atmospheric turbulence effects are modeled by either k–ω shear stress transport or detached eddy simulation. The power spectral responses and variances of the wing are computed by employing the Dryden atmospheric turbulence spectrum and the computed values of the local stress standard deviation of the Tsing Ma Bridge are compared with experimental values. The simulation results demonstrate that the proposed method can provide highly efficient numerical analysis of two kinds of wind-induced responses of structures and hence has significant benefits for wind-induced vibration engineering
A Cost-Effectiveness Analysis of Comprehensive Smoking-Cessation Interventions Based on the Community and Hospital Collaboration
BackgroundThe prevalence of cigarette smoking in China is high and the utilization of smoking cessation clinics is very low. Multicomponent smoking cessation interventions involving community and hospital collaboration have the potential to increase the smoking cessation rate. However, the cost-effectiveness of this intervention model is unknown.MethodsWe conducted a smoking cessation intervention trial in 19 community health service centers in Beijing, China. A cost-effectiveness analysis was performed from a societal perspective to compare three strategies of smoking cessation: no intervention (NI), pharmacological intervention (PI), and comprehensive intervention (CI) (PI plus online health promotion). A Markov model, with a time horizon of 20 years, was used to simulate the natural progression of estimated 10,000 male smokers. A cross-sectional survey was conducted to obtain data on costs and quality-adjusted life years (QALYs) by using the five-level EuroQol-5-dimension (EQ-5D-5L) questionnaire. Probabilistic sensitivity analysis was performed to explore parameters of uncertainty in the model.ResultsA total of 680 participants were included in this study, including 283 in the PI group and 397 in the CI group. After 6 months of follow-up, the smoking cessation rate reached 30.0% in the CI group and 21.2% in the PI group. Using the Markov model, compared with the NI group, the intervention strategies of the PI group and the CI group were found to be cost-effective, with an incremental cost-effectiveness ratio (ICER) of 366.19/QALY, respectively. The probabilistic sensitivity analysis indicated that the CI strategy was always the most cost-effective intervention.ConclusionCI for smoking cessation, based in hospital and community in China, is more cost-effective than PI alone. Therefore, this smoking cessation model should be considered to be implemented in healthcare settings
Exploring the allelopathic autotoxicity mechanism of ginsenosides accumulation under ginseng decomposition based on integrated analysis of transcriptomics and metabolomics
Continuous cropping obstacles seriously constrained the sustainable development of the ginseng industry. The allelopathic autotoxicity of ginsenosides is the key “trigger” of continuous cropping obstacles in ginseng. During harvest, the ginseng plants could be broken and remain in the soil. The decomposition of ginseng residue in soil is one of the important release ways of ginsenosides. Therefore, the allelopathic mechanism of ginsenosides through the decomposed release pathway needs an in-depth study. To investigate this allelopathic regulation mechanism, the integrated analysis of transcriptomics and metabolomics was applied. The prototype ginsenosides in ginseng were detected converse to rare ginsenosides during decomposition. The rare ginsenosides caused more serious damage to ginseng hairy root cells and inhibited the growth of ginseng hairy roots more significantly. By high-throughput RNA sequencing gene transcriptomics study, the significantly differential expressed genes (DEGs) were obtained under prototype and rare ginsenoside interventions. These DEGs were mainly enriched in the biosynthesis of secondary metabolites and metabolic pathways, phytohormone signal transduction, and protein processing in endoplasmic reticulum pathways. Based on the functional enrichment of DEGs, the targeted metabolomics analysis based on UPLC-MS/MS determination was applied to screen endogenous differential metabolized phytohormones (DMPs). The influence of prototype and rare ginsenosides on the accumulation of endogenous phytohormones was studied. These were mainly involved in the biosynthesis of diterpenoid, zeatin, and secondary metabolites, phytohormone signal transduction, and metabolic pathways. After integrating the transcriptomics and metabolomics analysis, ginsenosides could regulate the genes in phytohormone signaling pathways to influence the accumulation of JA, ABA, and SA. The conclusion was that the prototype ginsenosides were converted into rare ginsenosides by ginseng decomposition and released into the soil, which aggravated its allelopathic autotoxicity. The allelopathic mechanism was to intervene in the response regulation of genes related to the metabolic accumulation of endogenous phytohormones in ginseng. This result provides a reference for the in-depth study of continuous cropping obstacles of ginseng
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