Di Zhao
Current Organizations / Institutes
The organizations/institutes from the scholar's latest article
Previous Organizations / Institutes
The organizations / institutes from the scholar's other articles in the past ten years
Di Zhao has a total of 43 co-authors. Here are the top co-authors by number of shared publications:
- Hongyi Li
School of Cyber Science and Technology, Beihang University, Beijing, China
15 shared publications Hongyi Li
School of Mathematical Sciences, Beihang University, Beijing, China
12 shared publications- Chengwei Pan
Institute of Artificial Intelligence, Beihang University, Beijing 100191, China
8 shared publications - Kejia Hu
School of Electronics and Communication Engineering, Sun Yat-sen University, Shenzhen 518107, China
5 shared publications - Yuan Jiang
School of Electronics and Communication Engineering, Sun Yat-sen University, Shenzhen, China
4 shared publications Jiaxin Chen
Department of Electrical and Computer Engineering New York University Abu Dhabi UAE
3 shared publications
Latest Publications
- Open Access
- 30 August 2025
- Published by Springer Nature in Artificial Intelligence Review
- Vol. 58 (11) , 1-37
DAoG: decayed adaptation over gradients for parameter-free step size control
- 30 August 2025
- Published by Springer Nature in Artificial Intelligence Review
- Vol. 58 (11) , 1-37
Open AccessDAoG: decayed adaptation over gradients for parameter-free step size control
- Open Access
- 28 May 2025
- Published by Springer Nature in Neural Processing Letters
- Vol. 57 (3) , 1-25
AdamRAG: Adaptive Algorithm with Ravine Method for Training Deep Neural Networks
- 28 May 2025
- Published by Springer Nature in Neural Processing Letters
- Vol. 57 (3) , 1-25
Open AccessAdamRAG: Adaptive Algorithm with Ravine Method for Training Deep Neural Networks
- Open Access
- 5 April 2025
- Published by MDPI AG in Mathematics
- Vol. 13 (7) , 1200
Geometric Properties of a General Kohn–Nirenberg Domain in ℂn
The Kohn–Nirenberg domains are unbounded domains in . In this article, we modify the Kohn–Nirenberg domain and discuss the existence of supporting surface and peak functions at the origin.- 5 April 2025
- Published by MDPI AG in Mathematics
- Vol. 13 (7) , 1200
Open AccessGeometric Properties of a General Kohn–Nirenberg Domain in ℂn
The Kohn–Nirenberg domains are unbounded domains in . In this article, we modify the Kohn–Nirenberg domain and discuss the existence of supporting surface and peak functions at the origin. - Open Access
- 6 March 2025
- Published by MDPI AG in Preprints.org
Geometric Properties of a General Kohn-Nirenberg Domain in Cn
The Kohn-Nirenberg domains are unbounded domains in $\mathbb{C}^{n}$. In this article, we modify the Kohn-Nirenberg domain $\Omega_{K,L} =\left\{(z_{1},\ldots, z_{n}) \right.\in \mathbb{C}^{n} : Re z_{n} + g \mid z_{n}\mid^{2} + \sum_{j = 1}^{n-1} (\mid z_{j}\mid^{p} +K_{j} \mid z_{j}\mid^{p-q} Re z_{j}^{q} + L_{j} \mid z_{j}\mid^{p-2q} Im z_{j}^{2q}) < 0 \}$ and discuss the existence of supporting surface and peak function at the origin.- 6 March 2025
- Published by MDPI AG in Preprints.org
Open AccessGeometric Properties of a General Kohn-Nirenberg Domain in Cn
The Kohn-Nirenberg domains are unbounded domains in $\mathbb{C}^{n}$. In this article, we modify the Kohn-Nirenberg domain $\Omega_{K,L} =\left\{(z_{1},\ldots, z_{n}) \right.\in \mathbb{C}^{n} : Re z_{n} + g \mid z_{n}\mid^{2} + \sum_{j = 1}^{n-1} (\mid z_{j}\mid^{p} +K_{j} \mid z_{j}\mid^{p-q} Re z_{j}^{q} + L_{j} \mid z_{j}\mid^{p-2q} Im z_{j}^{2q}) < 0 \}$ and discuss the existence of supporting surface and peak function at the origin. - Open Access
- 26 January 2025
- Published by MDPI AG in Mathematics
- Vol. 13 (3) , 414
Golden Angle Modulation in Complex Dimension Two
In this paper, we propose a new geometric-shaping design for golden angle modulation (GAM) based on the complex geometric properties of open symmetrized bidisc, termed Bd-GAM, for future generation wireless communication systems. Inspired from the circular symmetric structure of the GAM, we construct the modulation schemes, Bd-GAM1 and Bd-GAM2. Specifically, we consider MI-optimized probabilistic modulation scheme with the geometrics properties of symmetric bidisc. With minimum SNR and entropy constraint, Bd-GAM1 and Bd-GAM2 can overcome the shaping-loss. Compared with the existed golden angle modulation introduced, the new design improves the mutual information, and the distance between adjacent constellation points.
- 26 January 2025
- Published by MDPI AG in Mathematics
- Vol. 13 (3) , 414
Open AccessGolden Angle Modulation in Complex Dimension Two
In this paper, we propose a new geometric-shaping design for golden angle modulation (GAM) based on the complex geometric properties of open symmetrized bidisc, termed Bd-GAM, for future generation wireless communication systems. Inspired from the circular symmetric structure of the GAM, we construct the modulation schemes, Bd-GAM1 and Bd-GAM2. Specifically, we consider MI-optimized probabilistic modulation scheme with the geometrics properties of symmetric bidisc. With minimum SNR and entropy constraint, Bd-GAM1 and Bd-GAM2 can overcome the shaping-loss. Compared with the existed golden angle modulation introduced, the new design improves the mutual information, and the distance between adjacent constellation points.
- Open Access
- 30 December 2024
- Published by MDPI AG in Preprints.org
Golden Angle Modulation in Complex Dimension Two
In this paper, we propose a new geometric-shaping design for golden angle modulation (GAM) based on the complex geometric properties of open symmetrized bidisc, termed Bd-GAM, for future generation wireless communication systems. Inspired from the circular symmetric structure of the GAM, we construct the modulation schemes, Bd-GAM1 and Bd-GAM2. However, the optimization problem is hard to solve analytically, we consider this problem in the domain of symmetrized bidisc. Specifically, we joint the complex geometrics properties of symmetric bidisc and MI-optimized probabilistic modulation scheme. The symmetric bidisc is a bounded domain on which the Carathe´odory distance and the Kobayashi distance coincide. We can use the pseudo-metric mD in unit disc D to get the Kobayashi pseudo-distance and Carathe´odory pseudo-distance. With minimum SNR and entropy constraint, Bd-GAM1 and Bd-GAM2 can overcome the shaping-loss. This study finds that each constellation point of Bd-GAM has a unique phase and gain. Compared with the existed golden angle modulation introduced, the new design improves the mutual informaiton (MI), and the distance between adjacent constellation points.
- 30 December 2024
- Published by MDPI AG in Preprints.org
Open AccessGolden Angle Modulation in Complex Dimension Two
In this paper, we propose a new geometric-shaping design for golden angle modulation (GAM) based on the complex geometric properties of open symmetrized bidisc, termed Bd-GAM, for future generation wireless communication systems. Inspired from the circular symmetric structure of the GAM, we construct the modulation schemes, Bd-GAM1 and Bd-GAM2. However, the optimization problem is hard to solve analytically, we consider this problem in the domain of symmetrized bidisc. Specifically, we joint the complex geometrics properties of symmetric bidisc and MI-optimized probabilistic modulation scheme. The symmetric bidisc is a bounded domain on which the Carathe´odory distance and the Kobayashi distance coincide. We can use the pseudo-metric mD in unit disc D to get the Kobayashi pseudo-distance and Carathe´odory pseudo-distance. With minimum SNR and entropy constraint, Bd-GAM1 and Bd-GAM2 can overcome the shaping-loss. This study finds that each constellation point of Bd-GAM has a unique phase and gain. Compared with the existed golden angle modulation introduced, the new design improves the mutual informaiton (MI), and the distance between adjacent constellation points.
- Open Access
- 26 November 2024
- Published by Springer Nature in Complex & Intelligent Systems
- Vol. 11 (1) , 1-14
Quality assessment of cyber threat intelligence knowledge graph based on adaptive joining of embedding model
- 26 November 2024
- Published by Springer Nature in Complex & Intelligent Systems
- Vol. 11 (1) , 1-14
Open AccessQuality assessment of cyber threat intelligence knowledge graph based on adaptive joining of embedding model
- Open Access
- 28 July 2024
- Published by MDPI AG in Mathematics
- Vol. 12 (15) , 2355
CPSGD: A Novel Optimization Algorithm and Its Application in Side-Channel Analysis
In recent years, side-channel analysis based on deep learning has garnered significant attention from researchers. A pivotal reason for this lies in the fact that deep learning-based side-channel analysis requires minimal preprocessing of side-channel data. The automatic feature extraction property of deep learning methods drastically reduces the workload for researchers, enabling them to focus more on the core issues of side-channel analysis, namely, extracting sensitive information by attacking devices. However, in prior studies, most scholars have concentrated more on the model construction process, with little research focusing on the choice of optimizers.This paper explores a novel deep learning-based optimization algorithm—CPSGD (combined projection stochastic gradient descent). The algorithm comprises two variants, designed, respectively, for unprotected side-channel analysis (CPSGD1) and desynchronized side-channel analysis (CPSGD2), and their convergence has been theoretically proven. Experimental results demonstrate that, while maintaining the neural network structure unchanged, CPSGD1 exhibits the best performance on unprotected datasets compared to other publicly available optimizers, whereas CPSGD2 performs optimally on desynchronized datasets.
- 28 July 2024
- Published by MDPI AG in Mathematics
- Vol. 12 (15) , 2355
Open AccessCPSGD: A Novel Optimization Algorithm and Its Application in Side-Channel Analysis
In recent years, side-channel analysis based on deep learning has garnered significant attention from researchers. A pivotal reason for this lies in the fact that deep learning-based side-channel analysis requires minimal preprocessing of side-channel data. The automatic feature extraction property of deep learning methods drastically reduces the workload for researchers, enabling them to focus more on the core issues of side-channel analysis, namely, extracting sensitive information by attacking devices. However, in prior studies, most scholars have concentrated more on the model construction process, with little research focusing on the choice of optimizers.This paper explores a novel deep learning-based optimization algorithm—CPSGD (combined projection stochastic gradient descent). The algorithm comprises two variants, designed, respectively, for unprotected side-channel analysis (CPSGD1) and desynchronized side-channel analysis (CPSGD2), and their convergence has been theoretically proven. Experimental results demonstrate that, while maintaining the neural network structure unchanged, CPSGD1 exhibits the best performance on unprotected datasets compared to other publicly available optimizers, whereas CPSGD2 performs optimally on desynchronized datasets.
- Open Access
- 24 August 2023
- Published by Springer Nature in Complex & Intelligent Systems
- Vol. 10 (1) , 1201-1217
Cybersecurity knowledge graphs construction and quality assessment
Cyber-attack activities are complex and ever-changing, posing severe challenges to cybersecurity personnel. Introducing knowledge graphs into the field of cybersecurity helps depict the intricate cybersecurity landscape and provides technical support for threat identification and situational awareness. However, during the process of constructing knowledge graphs, inevitable noise and conflicts may be introduced, leading to misleading inferences and decisions. This paper aims to address the issues of constructing and assessing the quality of cybersecurity knowledge graphs. We manually constructed a dataset of cybersecurity knowledge graphs (CS13K) and expanded the existing cybersecurity ontology, building a more versatile ontology applicable to existing data features. Building upon this, we utilized Neo4j to construct the cybersecurity knowledge graph. Furthermore, we propose an AttTucker model, based on Transformer, for assessing the quality of knowledge graphs. By employing numerous self-attention heads, this model captures latent information among entities and relations. While reducing the dimensionality of knowledge embeddings, the model achieves evaluation results comparable to high-dimensional embeddings. Finally, we incorporate the path-level information between entities in the knowledge graph into the evaluation of knowledge graph quality based on the AttTucker model. Experimental analysis on both generic datasets and cybersecurity datasets demonstrates that our model significantly improves F1 value and accuracy in knowledge graph quality assessment tasks, outperforming other models.
- 24 August 2023
- Published by Springer Nature in Complex & Intelligent Systems
- Vol. 10 (1) , 1201-1217
Open AccessCybersecurity knowledge graphs construction and quality assessment
Cyber-attack activities are complex and ever-changing, posing severe challenges to cybersecurity personnel. Introducing knowledge graphs into the field of cybersecurity helps depict the intricate cybersecurity landscape and provides technical support for threat identification and situational awareness. However, during the process of constructing knowledge graphs, inevitable noise and conflicts may be introduced, leading to misleading inferences and decisions. This paper aims to address the issues of constructing and assessing the quality of cybersecurity knowledge graphs. We manually constructed a dataset of cybersecurity knowledge graphs (CS13K) and expanded the existing cybersecurity ontology, building a more versatile ontology applicable to existing data features. Building upon this, we utilized Neo4j to construct the cybersecurity knowledge graph. Furthermore, we propose an AttTucker model, based on Transformer, for assessing the quality of knowledge graphs. By employing numerous self-attention heads, this model captures latent information among entities and relations. While reducing the dimensionality of knowledge embeddings, the model achieves evaluation results comparable to high-dimensional embeddings. Finally, we incorporate the path-level information between entities in the knowledge graph into the evaluation of knowledge graph quality based on the AttTucker model. Experimental analysis on both generic datasets and cybersecurity datasets demonstrates that our model significantly improves F1 value and accuracy in knowledge graph quality assessment tasks, outperforming other models.
- 17 June 2023
- Published by Springer Nature in Journal of Scientific Computing
- Vol. 96 (2) , 1-35
Fast Gradient Method for Low-Rank Matrix Estimation
- 17 June 2023
- Published by Springer Nature in Journal of Scientific Computing
- Vol. 96 (2) , 1-35
Fast Gradient Method for Low-Rank Matrix Estimation