Objective: As the scale and importance of official development assistance (ODA) continue to grow, the need to enhance the effectiveness of ODA policies has become more critical than ever before. In this context, it is essential to systematically classify recipient countries and establish tailored ODA policies based on these classifications. The objective of this study is to identify an appropriate methodology for categorizing developing countries using specific criteria, and to apply it to actual data, providing valuable insights for donor countries in formulating future ODA policies. Design/Methodology/Approach: The data used in this study are the basic statistics on the Sustainable Development Goals (SDGs) published annually in the SDGs Report. The analytical method employed is decision tree analysis. Results: The results indicate that the 167 countries analyzed were classified into 10 distinct nodes. The study further limited the scope to the five nodes representing the most disadvantaged developing countries and suggested future directions for aid policies for each of these nodes.

Fujian Tubao, a defensive residential structure predominantly found in central Fujian, represents a significant cultural heritage of the region. However, with the rapid urbanization underway, Fujian Tubao faces the threat of extinction, presenting severe challenges to its survival and development. Identifying a sustainable development path for Fujian Tubao is crucial for preserving regional culture. This study uses Fuxing Bao, a quintessential example of Fujian Tubao, as a case study to explore conservation methods based on adaptive reuse. Through field surveys, questionnaires, in-depth interviews, and case studies, we analyze the historical background of the building, focusing on the current physical and social environment of Fuxing Bao. Our findings indicate that the current state of preservation of Fuxing Bao can meet the requirements for adaptive reuse. By integrating results from surveys and interviews with local villagers, we propose sustainable development strategies and conservation methods. This research offers a sustainable development model for Fujian Tubao and other traditional regional dwellings. By adopting an adaptive reuse perspective, it aims to better address the conflict between modern living and traditional architectural preservation, ensuring that these architectural spaces are properly protected and continue to play a unique role in contemporary society.