1. Full name: Nguyen Dinh Nghia                                    2. Sex: Male

3. Date of birth: 10/09/1978                                                        4. Place of birth: Bac Ninh

5. Admission decision number: 3205/QĐ-ĐT    Dated: 08/11/2010

6. Changes in academic process:

7. Official thesis title: Research on performance improvement of structured peer-to-peer networks

8. Major: Networking and Data transmission    9. Code: 9480102.01

10. Supervisors: Dr. Nguyen Hoai Son and Assoc. Prof. Dr. Ho Sy Dam

11. Summary of the new findings of the thesis:

- Proposed solutions to improve the load balancing algorithm by the mechanism for storing information about heavy and lightweight nodes at the node as a directory, and to consider load processing for one-node search queries during load balancing.

- Proposed a solution for congestion control during routing the notifications by the distributed hashing algorithm. The proposed solution involves replacing the congestion node in the routing table of the forwarding node to create a new route. to the key management node that is not congested. The proposed solution allows to take advantage of the network resources of non-congested nodes while does not increase the number of hops during the notification routing

- Proposed a data backup solution based on dynamic clustering on the DHT key space to ensure the availability of the data. The thesis proposes a mechanism for updating information between nodes in the cluster to ensure load balancing and data recovery mechanisms when there are nodes leaving the network. In addition, the thesis also proposed a network join mechanism that allows neighboring nodes physically to join the same cluster to reduce cluster update time and cost to maintain data in clusters.

12. Practical applicability, if any:

The solution proposed in the thesis can be used to improve the performance of peer-to-peer file sharing systems and peer information query systems.

13. Further research directions, if any:

- Solve the problem of load balancing for search range queries

- Study the issue of ensuring security for the directory.

- Study the problem of deleting unnecessary files when a node is overloaded.

14. Thesis-related publications:

[V1]. Hoai Son Nguyen, Dinh Nghia Nguyen, Shinji SUGAWARA Senior Member, "A Dynamic-Clustering Backup Scheme for High-Availability Distributed File Sharing Systems". IEICE Transactions on Communications Vol.E102-B, No.3, pp.545-556, Mar.2019. (SCI, impact factor: 1.09).

[V2]. Nguyen Dinh Nghia, Nguyen Hoai Son, "Congestion control algorithm for message routing in Structured Peer-to-peer Networks". Journal of Computer Science and Cybernetics, Vol 34, No 2, 2018, pp.145-159.

[V3]. Dinh Nghia Nguyen, Xuan Hoang Tran, Hoai Son Nguyen, "A Cluster-based File Replication Scheme for DHT-based File Backup System". Proceedings of The 2016 international conference on advanced technologies for communications. pp 204-214.

[V4]. Nguyễn Đình Nghĩa, Nguyễn Hoài Sơn, "Tối ưu hóa sao lưu dữ liệu trong mạng ngang hàng có cấu trúc". Kỷ yếu Hội nghị khoa học công nghệ quốc gia lần thứ VI (Fair 2013), Nxb Khoa học tự nhiên và Công nghệ, Hà Nội 2013. pp563-571.

[V5]. Nguyễn Đình Nghĩa, Đỗ Cao Minh, Nguyễn Hoài Sơn, “Nâng cao hiệu quả của thuật toán cân bằng tải theo ngưỡng trong mạng ngang hàng có cấu trúc”. Kỷ yếu hội thảo quốc gia về CNTT năm 2009, Nxb Khoa học và kỹ thuật. pp 206-280.