## 5 Implementation
### Results  
As blockchain data are difficult for users to view, an explorer tool is needed to query block information, transaction information, network node information, chaincode, and information stored in the ledger. Hyperledger Fabric utilizes the PostgreSQL database to provide users with the blockchain information as visualized data using the explorer. Therefore, the Hyperledger Explorer was used to read recorded data in the blockchain instead of code. Figure 7 shows the block information of the result data presented in Figure 6.  
Figure 7 provides the basic blockchain network-related information and transaction information. Peer information provide the list of network participants. One peer of Org, which corresponds to the IoT, contractor, inspection agency, and civic group, participates in the blockchain network. In addition, the MSP is activated to confirm the access authority of participants to the channel Xsite. Transaction information provides fine dust management information uploaded by each participant to the channel's blockchain. It shows that Xsite information was generated by the IoT, inspection agency, contractor, and system. Transaction information includes details, and the transaction detail (key value) from each workflow is shown in Figure 8.  
In the transaction details, input data are recorded in a key-value format. The key is a fixed value as specified in Section 4.2, and the value changes as the participants input it. According to Figure 8, the government inspection agency inputted 300 \(\upmu\)g/m\({}^{3}\) as a regulation value. When the IoT sensor received a value exceeding 300 \(\upmu\)g/m\({}^{3}\) on 2 July 2021/18:01:04, the system automatically sent an alarm message to the contractor. The alarm content contained information on who received the data and why the alarm message was sent. When the contractor uploads picture for dust reduction, the hash value and image Url of the picture are recorded.  
Figure 7: Peer and transaction information.  
Fine dust at construction sites must be measured in real time through IoT for immediate reduction, and information must be shared in real time for remote monitoring. Although the current system utilizes IoT, it is not an open system. There are many manual tasks, such as sending a message to reduce fine dust or on-site inspection by the government agency. However, this study automated a significant task, and all information recorded in the blockchain network is disclosed to participants. Table 3 shows a comparison between the existing system and the proposed system. The results are the average values of 15 experiments. As the aim of this study is reliability, rather than improving the accuracy of the IoT sensor for the measurement of fine dust concentration at the construction site, it verifies the speed of the work process that can be implemented in real time for data sharing. Similar to the current system, the fine dust IoT measurement system of the local government of Seoul, South Korea, is an object of comparison. According to Table 3, the proposed system reduces the time required for work through automation, and the required time is reasonable. In addition, it enhances reliability through the photo upload function and photo forgery detection. As shown in Figure 8, the data can be shared through transaction details in real time.  
Table 4 shows the qualitative comparison evaluation results of the proposed system and the existing system. In terms of reliability, the proposed system provides decentralization based on blockchain. blockchain Information cannot be falsified through HMac or a distributed ledger, so network participants can trust and share information. In addition, human intervention was minimized through chaincode. In terms of efficiency, the work process was automated. In addition, new construction sites and participants can easily participate in the network by using the provided chaincode, multi-channel, and MSP.  
Figure 8: Transaction details for key-value data.