China’s economic statecraft at the contemporary stage and its role in national security

This thesis explores China’s economic statecraft in the 20 years since the Tiananmen crisis and its role in China’s approach to national security. It examines the intertwined relations between the strategy of economic statecraft and the service of this strategy in China’s national security interests. It takes a regional focus of this relationship, using China–Africa and China–ASEAN as comparative examples. The thesis is structured in three parts. Part I first presents the theory of national security (Chapter Two) and the study of economic statecraft (Chapter Three). On the basis of the theoretical frameworks it raises two hypotheses respectively: first, for a rapidly-growing economy, like China, the focus on economic development affects its security concept, which makes China pursue national security by means of economic security; and second, on the pursuit of security interests, the strategy of peaceful rising leads to the preference on economic diplomacy, instead of military instrument, though the specific approach of economic diplomacy may vary by region. To verify these hypotheses, Part II starts with the analysis on China’s security concept (Chapter Four) and its mode of economic statecraft in diplomacy (Chapter Five). The scenario of the security situation in China indicates the importance of economic security due to the significant relevance of China’s political security and social stability – supporting the first hypothesis (Hypothesis I) – but military security in the neighbouring area is still prominent. The arguments on the role of economic statecraft in China’s diplomatic history since its founding in 1949 lead to the conclusion that, since the Chinese government largely defines its security concept as economic security with regional diplomacy predominating, the model of economic statecraft has shifted towards pragmatic security concerns and away from the ideologically based strategy of the past. Part III further demonstrates the inter-linkage between security interests and economic statecraft in China’s external relations, by exploring the strategic relations between China and Africa and between China and ASEAN. Chapter Six on China–Africa engagement identifies that the significance of Africa for Chinese security rests in the continent’s increasing role in resources supply to Chinese economy. The primary motivation behind the Forum on China–Africa Cooperation is to foster economic exchanges in resources through massive incentive strategies, foreign aid in particular. In comparison, Chapter Seven on China–ASEAN engagement argues that the relations with ASEAN are crucial for Chinese economic security and regional security especially. The China–ASEAN Free Trade Agreement is an approach of economic statecraft that seeks to minimise the negative effects of the South China Sea dispute with the maritime ASEAN states and to produce a transportation corridor for energy supplies through the continental members, bypassing the ‘Malacca Dilemma’ of the sea lanes. These arguments entirely support the second hypothesis. The thesis concludes that economic statecraft, being the strategy of economic diplomacy, has been playing an impressive role in service for China’s national security interests, illustrated in safeguarding regional security in the Southeast Asian area and economic security in the far African continent. However, China’s economic diplomacy towards the two areas is debatable: the aid policy towards Africa needs to be improved and the free trade agreement with ASEAN may not be effective in solving the disputes on the South China Sea

Linear-quadratic Mean Field Control with Non-convex Data

In this manuscript, we study a class of linear-quadratic (LQ) mean field control problems with a common noise and their corresponding $N$-particle systems. The mean field control problems considered are not standard LQ mean field control problems in the sense that their dependence on the mean field terms can be non-linear and non-convex. Therefore, all the existing methods to deal with LQ mean field control problems fail. The key idea to solve our LQ mean field control problem is to utilize the common noise. We first prove the global well-posedness of the corresponding Hamilton-Jacobi equations via the non-degeneracy of the common noise. In contrast to the LQ mean field games master equations, the Hamilton-Jacobi equations for the LQ mean field control problems can not be reduced to finite-dimensional PDEs. We then globally solve the Hamilton-Jacobi equations for $N$-particle systems. As byproducts, we derive the optimal quantitative convergence results from the $N$-particle systems to the mean field control problem and the propagation of chaos property for the related optimal trajectories. This paper extends the results in [{\sc M. Li, C. Mou, Z. Wu and C. Zhou}, \emph{Trans. Amer. Math. Soc.}, 376(06) (2023), pp.~4105--4143] to the LQ mean field control problems.Comment: 35 page

Scenario Analyses of Land Use Conversion in the North China Plain: An Econometric Approach

Scenario analysis and dynamic prediction of land use structure which involve many driving factors are helpful to investigate the mechanism of land use changes and even to optimize land use allocation for sustainable development. In this study, land use structure changes during 1988–2010 in North China Plain were discerned and the effects of various natural and socioeconomic driving factors on land use structure changes were quantitatively analyzed based on an econometric model. The key drivers of land use structure changes in the model are county-level net returns of land resource. In this research, we modified the net returns of each land use type for three scenarios, including business as usual (BAU) scenario, rapid economic growth (REG) scenario, and coordinated environmental sustainability (CES) scenario. The simulation results showed that, under different scenarios, future land use structures were different due to the competition among various land use types. The land use structure changes in North China Plain in the 40-year future will experience a transfer from cultivated land to built-up area, an increase of forestry, and decrease of grassland. The research will provide some significant references for land use management and planning in the study area

Context-aware Event Forecasting via Graph Disentanglement

Event forecasting has been a demanding and challenging task throughout the entire human history. It plays a pivotal role in crisis alarming and disaster prevention in various aspects of the whole society. The task of event forecasting aims to model the relational and temporal patterns based on historical events and makes forecasting to what will happen in the future. Most existing studies on event forecasting formulate it as a problem of link prediction on temporal event graphs. However, such pure structured formulation suffers from two main limitations: 1) most events fall into general and high-level types in the event ontology, and therefore they tend to be coarse-grained and offers little utility which inevitably harms the forecasting accuracy; and 2) the events defined by a fixed ontology are unable to retain the out-of-ontology contextual information. To address these limitations, we propose a novel task of context-aware event forecasting which incorporates auxiliary contextual information. First, the categorical context provides supplementary fine-grained information to the coarse-grained events. Second and more importantly, the context provides additional information towards specific situation and condition, which is crucial or even determinant to what will happen next. However, it is challenging to properly integrate context into the event forecasting framework, considering the complex patterns in the multi-context scenario. Towards this end, we design a novel framework named Separation and Collaboration Graph Disentanglement (short as SeCoGD) for context-aware event forecasting. Since there is no available dataset for this novel task, we construct three large-scale datasets based on GDELT. Experimental results demonstrate that our model outperforms a list of SOTA methods.Comment: KDD 2023, 9 pages, 7 figures, 4 table

Direct fiber comb stabilization to a gas-filled hollow-core photonic crystal fiber

We have isolated a single tooth from a fiber laser-based optical frequency comb for nonlinear spectroscopy and thereby directly referenced the comb. An 89 MHz erbium fiber laser frequency comb is directly stabilized to the P(23) (1539.43 nm) overtone transition of [superscript]12C[subscript]2H[subscript]2 inside a hollow-core photonic crystal fiber. To do this, a single comb tooth is isolated and amplified from 20 nW to 40 mW with sufficient fidelity to perform saturated absorption spectroscopy. The fractional stability of the comb, ~7 nm away from the stabilized tooth, is shown to be 6 × 10[superscript]−12 at 100 ms gate time, which is over an order of magnitude better than that of a comb referenced to a GPS-disciplined Rb oscillator