Reputation-Based Dynamic Contract Incentive Mechanism in Mobile Crowdsourcing Network

Abstract Mobile crowdsourcing network is a promising technology utilizing the mobile ter- minal’s sensing and computing capabilities to collect and process data. However, because the mobile users (MUs) have selfish characteristics, the MUs only aim at maximizing their benefits. Therefore, how to design an appropriate long-term incentive mechanism for the service provider (SP) in dynamic environments is an urgent problem. In this work, we investigate the reputation-based dynamic contract for mobile crowdsourcing network. A two-period dynamic contract is first investi- gated to deal with the asymmetric information problem in the long-term crowd- sourcing tasks. Reputation strategy is introduced to attract the MUs to complete the long-term tasks. The incentives of the contract and the implicit incentives of the reputation strategy are used together to encourage MUs to complete the long-term crowdsourcing tasks. The optimization strategy is formulated by adjust- ing the reputation coefficient to maximize the SP’s utility. The impact of MUs’ risk attitude and reputation impact factors on the incentive mechanism is studied through experiments. Numerical simulation results demonstrate that the optimal reputation-based contract design scheme is efficient in the Mobile crowdsourcing networks.

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Multistrategy Repeated Game-Based Mobile Crowdsourcing Incentive Mechanism for Mobile Edge Computing in Internet of Things

Wireless Communications and Mobile Computing ◽

10.1155/2021/6695696 ◽

2021 ◽

Vol 2021 ◽

pp. 1-18

Author(s):

Chuanxiu Chi ◽

Yingjie Wang ◽

Yingshu Li ◽

Xiangrong Tong

Keyword(s):

Game Theory ◽

Internet Of Things ◽

Incentive Mechanism ◽

Repeated Game ◽

Edge Computing ◽

Quality Data ◽

Mobile Edge Computing ◽

High Quality ◽

Mobile Crowdsourcing

With the advent of the Internet of Things (IoT) era, various application requirements have put forward higher requirements for data transmission bandwidth and real-time data processing. Mobile edge computing (MEC) can greatly alleviate the pressure on network bandwidth and improve the response speed by effectively using the device resources of mobile edge. Research on mobile crowdsourcing in edge computing has become a hot spot. Hence, we studied resource utilization issues between edge mobile devices, namely, crowdsourcing scenarios in mobile edge computing. We aimed to design an incentive mechanism to ensure the long-term participation of users and high quality of tasks. This paper designs a long-term incentive mechanism based on game theory. The long-term incentive mechanism is to encourage participants to provide long-term and continuous quality data for mobile crowdsourcing systems. The multistrategy repeated game-based incentive mechanism (MSRG incentive mechanism) is proposed to guide participants to provide long-term participation and high-quality data. The proposed mechanism regards the interaction between the worker and the requester as a repeated game and obtains a long-term incentive based on the historical information and discount factor. In addition, the evolutionary game theory and the Wright-Fisher model in biology are used to analyze the evolution of participants’ strategies. The optimal discount factor is found within the range of discount factors based on repeated games. Finally, simulation experiments verify the existing crowdsourcing dilemma and the effectiveness of the incentive mechanism. The results show that the proposed MSRG incentive mechanism has a long-term incentive effect for participants in mobile crowdsourcing systems.

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Assessment of the impact of traffic volume on NO2 levels in Munich during the lock-down periods

10.5194/dach2022-161 ◽

2021 ◽

Author(s):

Sheng Ye ◽

Ka Lok Chan ◽

Tamara Brunner ◽

Hanlin Zhang ◽

Alexander Geiß ◽

...

Keyword(s):

Meteorological Parameters ◽

Early Stage ◽

Measurement Techniques ◽

Absolute Humidity ◽

Ground Level ◽

Traffic Volume ◽

Impact Factors ◽

Long Term Study ◽

The Impact

The global pandemic has many negative economic, social and health impacts, but the lock-downs also led to a reduction of traffic volume which resulted in lower NO2 levels in some areas. Our study made use of different air quality measurement techniques (in-situ, on-road, satellite remote sensing) to monitor long-term NO2 levels in Munich. While comparing NO2 levels associate with traffic volume before and after a lock-down, other influences based on meteorological parameters should be considered as well. In addition to traffic data we used records of wind, mixing layer height, temperature, humidity and other meteorological parameters to analyze the impact on measured pollution levels using a Generalized Additive Model (GAM) regression. Our long-term study using data between 2018 and 2021 shows that the dominating factor is wind speed, followed by traffic volume as the main factors for impacting NO2 levels, while absolute humidity and wind direction show less effects. We utilized those findings to find best suited time periods comparable to the lockdown time in terms of meteorological conditions. In order to focus on the traffic volume factor, we applied these findings to minimize other impact factors to evaluate the NO2 variability of different years comparing to the data from the lockdown periods. A significant reduction of the ground level NO2 concentrations in Munich during the early stage of the lockdown period in March 2020 could clearly be associated with a significant reduction of traffic volume.

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Long-Term Atmospheric Visibility Trends and Their Relations to Socioeconomic Factors in Xiamen City, China

International Journal of Environmental Research and Public Health ◽

10.3390/ijerph15102239 ◽

2018 ◽

Vol 15 (10) ◽

pp. 2239 ◽

Cited By ~ 4

Author(s):

Weicong Fu ◽

Qunyue Liu ◽

Cecil Konijnendijk van den Bosch ◽

Ziru Chen ◽

Zhipeng Zhu ◽

...

Keyword(s):

Socioeconomic Factors ◽

Negative Impact ◽

Impact Factors ◽

Urban Greening ◽

Industrial Activities ◽

Atmospheric Visibility ◽

Xiamen City ◽

Urban Size ◽

The Impact

Atmospheric visibility (AV), one of the most concerning environmental issues, has shown a continuous decline in China’s urban areas, especially in Southeastern China. Existing studies have shown that AV is affected by air pollutants and climate change, which are always caused by human activities that are linked to socioeconomic factors, such as urban size, residents’ activities, industrial activities, and urban greening. However, the contribution of socioeconomic factors to AV is still not well understood, especially from a long-term perspective, which sometimes leads to ineffective policies. In this study, we used the structural equation model (SEM) in order to quantify the contribution of socioeconomic factors on AV change in Xiamen City, China, between 1987–2016. The results showed that the annual average AV of Xiamen between 1987–2016 was 12.00 km, with a change rate of −0.315 km/year. Urban size, industrial activities, and residents’ activities were found to have a negative impact on AV, while the impact of urban greening on the AV was modest. Among all of the indicators, the number of resident’s vehicles, total retail sales of consumer goods, and household electricity consumption were found to have the highest negative direct impact on the AV. The resident population, urban built-up area, and secondary industry gross domestic product (GDP) were the most important indirect impact factors. Based on our results, we evaluated the existing environmental regulations and policies of Xiamen City.

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High-level resistance to oxidative stress in Lactococcus lactis conferred by Bacillus subtilis catalase KatE

Microbiology ◽

10.1099/mic.0.27861-0 ◽

2005 ◽

Vol 151 (9) ◽

pp. 3011-3018 ◽

Cited By ~ 43

Author(s):

T. Rochat ◽

A. Miyoshi ◽

J. J. Gratadoux ◽

P. Duwat ◽

S. Sourice ◽

...

Keyword(s):

Oxidative Stress ◽

Bacillus Subtilis ◽

Lactococcus Lactis ◽

Fold Increase ◽

Inducible Promoter ◽

Optimization Strategy ◽

High Level ◽

The Impact ◽

Level Resistance

Lactococcus lactis, a lactic acid bacterium widely used for food fermentations, is often exposed to damaging stress conditions. In particular, oxidative stress leads to DNA, protein and membrane damages that can be lethal. As L. lactis has no catalase, the impact of production of the Bacillus subtilis haem catalase KatE on its oxidative stress resistance was tested. This cytoplasmic catalase was engineered for extracellular expression in L. lactis with an optimization strategy based on fusion to the nisin-inducible promoter and a lactococcal signal peptide (SPUsp45). The production of KatE by L. lactis conferred an 800-fold increase in survival after 1 h exposure to 4 mM hydrogen peroxide, and a 160-fold greater survival in long-term (3 days) survival of aerated cultures in a cydA mutant, which is unable to respire. The presence of KatE protected DNA from oxidative damage and limited its degradation after long-term aeration in a cydA/recA mutant, defective in DNA repair. L. lactis is thus able to produce active catalase that can provide efficient antioxidant activity.

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Suppressed, but Not Forgotten

Swiss Journal of Psychology ◽

10.1024/1421-0185/a000033 ◽

2011 ◽

Vol 70 (1) ◽

pp. 5-11 ◽

Cited By ~ 8

Author(s):

Beat Meier ◽

Anja König ◽

Samuel Parak ◽

Katharina Henke

Keyword(s):

Memory Trace ◽

Thought Suppression ◽

Test Phase ◽

Indirect Test ◽

Final Test ◽

Test Experiment ◽

And Control ◽

Cue Words ◽

The Impact

This study investigates the impact of thought suppression over a 1-week interval. In two experiments with 80 university students each, we used the think/no-think paradigm in which participants initially learn a list of word pairs (cue-target associations). Then they were presented with some of the cue words again and should either respond with the target word or avoid thinking about it. In the final test phase, their memory for the initially learned cue-target pairs was tested. In Experiment 1, type of memory test was manipulated (i.e., direct vs. indirect). In Experiment 2, type of no-think instructions was manipulated (i.e., suppress vs. substitute). Overall, our results showed poorer memory for no-think and control items compared to think items across all experiments and conditions. Critically, however, more no-think than control items were remembered after the 1-week interval in the direct, but not in the indirect test (Experiment 1) and with thought suppression, but not thought substitution instructions (Experiment 2). We suggest that during thought suppression a brief reactivation of the learned association may lead to reconsolidation of the memory trace and hence to better retrieval of suppressed than control items in the long term.

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The Impact of Anglicizing Former German-Language Psychology Journals on Authorship and Citation Frequencies

European Psychologist ◽

10.1027/1016-9040/a000074 ◽

2012 ◽

Vol 17 (3) ◽

pp. 190-198 ◽

Cited By ~ 2

Author(s):

Günter Krampen ◽

Thomas Huckert ◽

Gabriel Schui

Keyword(s):

Side Effects ◽

English Language ◽

General Trend ◽

Native Language ◽

Impact Factors ◽

German Language ◽

Journal Articles ◽

Number Of Citations ◽

The Impact ◽

Number Of Authors

Exemplary for other than English-language psychology journals, the impact of recent Anglicization of five former German-language psychology journals on (1) authorship (nationality, i.e., native language, and number of authors, i.e., single or multiple authorships), (2) formal characteristics of the journal (number of articles per volume and length of articles), and (3) number of citations of the articles in other journal articles, the language of the citing publications, and the impact factors (IF) is analyzed. Scientometric data on these variables are gathered for all articles published in the four years before anglicizing and in the four years after anglicizing the same journal. Results reveal rather quick changes: Citations per year since original articles’ publication increase significantly, and the IF of the journals go up markedly. Frequencies of citing in German-language journals decrease, citing in English-language journals increase significantly after the Anglicization of former German-language psychology journals, and there is a general trend of increasing citations in other languages as well. Side effects of anglicizing former German-language psychology journals include the publication of shorter papers, their availability to a more international authorship, and a slight, but significant increase in multiple authorships.

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