This research aims to build an appropriate leadership model for regional heads in mitigating disasters due to climate change that is occurring in Papua. Papua Island is one of the islands that is included in disaster-prone areas, namely earthquakes, flash floods, tidal floods and landslides. This disaster occurred due to Papua’s geological conditions in the form of activity on the Indo-Australian plate (southern part) and the Pacific plate (north-eastern part). Exploitation of nature carried out by companies and communities themselves in a particular area has an impact on the balance of the natural ecosystem. So far, disaster management has only focused on emergency response. Aid movements coordinated by ordinary people also focus more on raising aid for emergency situations. In fact, comprehensive disaster management includes before, during and after a disaster occurs. So a combination of leadership styles is needed that must be carried out at each phase of a disaster so that the right model can be produced. The results of this research found that the leadership model of regional heads in mitigating climate change in Papua is in accordance with the disaster management cycle with leadership styles, and traditional Papuan leadership styles. This combination is called a collaborative leadership model for disaster management in Papua. It is hoped that by implementing this model, climate change disaster mitigation can be effective.

ESG (environmental, social and governance, a framework used to assess an organisation’s business practices and performance on various sustainability and ethical issues) and Digital Transformation (the process of using digital technologies to change a business’s operations, products and services by integrating digital solutions into all areas of the business, which can lead to cultural and technological changes) are emerging issues across different industries, including the banking field. There has been limited research focusing on exploring the linkages between ESG, Digital Transformation and Customer Behaviour in the banking area, especially within developing countries such as Vietnam. Based on this gap, this study analyses and assesses the role of Digital Transformation and ESG on customer behaviour towards brands in the banking sector in Ho Chi Minh City. The research employed the quantitative research methods with the combination of fundamental analytical methods such as statistics, Cronbach’s alpha reliability, Exploratory Factor Analysis (EFA), measurement models and Partial Least Squares Structural Equation Modelling (PLS-SEM). The analysis was based on survey data from 550 customers who are the commercial banks’ current customers and live in Ho Chi Minh City, yielding 514 valid responses. Using SPSS and SMART PLS software, the study provided notable results. Specifically: (1) The component factors of ESG, including Environmental Issues (EN), Social Issues (SO), Government Issues (GO) and Digital Transformation (DT), positively influence Customer Behaviour (CB); (2) The component factors of ESG, including Environmental Issues (EN), Social Issues (SO) and Government Issues (GO), play a mediating role in the relationship between Digital Transformation (DT) and Customer Behaviour (CB).

Effective harvesting strategies are crucial for maximizing annual catch and ensuring the sustainability of lobster (Homarus americanus) farming. This paper presents a nonlinear objective programming model to optimize harvesting intensity based on lobster life cycle dynamics and harvesting characteristics. We model the population dynamics of 1-4 year-old lobsters using differential equations to account for natural mortality, spawning, and harvesting effects. Solving the model with LINGO 12.0, we determine that the optimal harvesting intensity coefficient is 17.36, which maximizes annual catch to 3.88 × 10¹⁰ grams. Results indicate that maintaining harvesting intensity around this optimal value balances economic benefits and population stability, ensuring sustainable farm operations.