## 4 User-Centric Multiple Incentive Mechanism
### Design of Multiple Incentive Mechanism  
For OSM, the extent of users' active participation is a crucial determinant of a community's success [43]. The more positive feedback users receive from the system, the more likely they are to continue participating actively [44]. Therefore, the user participation assessment algorithm, based on users' participatory behaviors within the NexoNet, assesses their level of participation to the blockchain and quantifies this into PV recorded on the blockchain system.  
Blockchain system often combine economic incentives with consensus mechanism to attract more user participation [38]. For example, the Bitcoin system, as the first to use the issuance of cryptocurrency as an incentive mechanism, attracted a vast number of users to join mining activities due to its high value. However, this cryptocurrency-based economic incentive also sparked a vicious competition for computational power, running counter to the blockchain's original intention of decentralization.  
The incentive mechanism in NexoNet offers several functional advantages by utilizing blockchain technology. First, the decentralized nature of the blockchain ensures that PV are stored and managed transparently, preventing any central authority from manipulating the system. Unlike traditional centralized platforms, where the allocation of rewards might be controlled by the platform operator, NexoNet provides a fair and transparent reward distribution based on users' actual contributions. The immutability of blockchain records guarantees that users' earned incentives cannot be altered or disputed after they are recorded. Furthermore, blockchain automates the reward distribution process, ensuring that users are fairly compensated without the need for intermediaries. In the NexoNet proposed in this paper, a multiple incentive mechanism is employed to motivate users in four main aspects without the use of token or cryptocurrency:  
* Content revenue incentive: Upon publishing content, creators set a price for their work, allowing other users to purchase it. All earnings from the content, including purchases and rewards from other users, are maintained in a content reward pool. A portion of this reward pool becomes the original author's income, while the rest supports system maintenance.
* PV incentive: Users earn PV rewards both by publishing content as creators or by engaging as readers through purchasing and evaluating content. This serves as proof of active participation within the system. Authors of high-quality works can receive additional PV rewards.
* Blockchain system incentive: Users partake in the blockchain consensus mechanism by voting for blockchain maintainers. Upon the successful generating of a block by the voted maintainer, voters can receive a portion of the transaction fee from the block as a reward.
* Other value incentives: Generating high-quality content increases users' exposure, enhancing their personal value. Highly active users in the NexoNet gain greater voting rights, participating in governance to decide the system's development direction. Furthermore, user-generated content receives social value feedback from other users, such as appreciations and rewards.  
In the context of OSM applications, the content produced by users constitutes the core value of the entire blockchain system. To encourage active user participation, this paper proposes user participation assessment algorithm. This algorithm encompasses generating content, purchasing content, and content quality assessment, rewarding users directly in the form of PV.