How do Geohazards Affect Household Consumption: Evidence From China

Geohazards trigger well-documented adverse effects on human health and economic development. However, previous studies mostly focused on the impact of one specific geohazard on consumption and discussed the impact mechanism from a limited perspective. In this paper, we focus on the consequences of generalized geohazards on household consumption in China and investigate the mechanisms of the impact of geohazards on consumption from three perspectives by using the China Household Finance Survey 2017 microdata and National Bureau of Statistics provincial-level data. The study finds that, firstly, household consumption is significantly higher in areas with more geohazards and the effect is found to be long-term. This finding passes a series of robust tests. Secondly, heterogeneity analysis reveals that the consumption structure of families is changed by geohazards. Moreover, the frequency of geohazards affects the consumption of households at different income-level to different degrees. Thirdly, among three possible impact mechanisms, the main mechanism of the impact of geohazards on household consumption is through the increasing of individuals’ impatience

A Thrust Allocation Method for Efficient Dynamic Positioning of a Semisubmersible Drilling Rig Based on the Hybrid Optimization Algorithm

A thrust allocation method was proposed based on a hybrid optimization algorithm to efficiently and dynamically position a semisubmersible drilling rig. That is, the thrust allocation was optimized to produce the generalized forces and moment required while at the same time minimizing the total power consumption under the premise that forbidden zones should be taken into account. An optimization problem was mathematically formulated to provide the optimal thrust allocation by introducing the corresponding design variables, objective function, and constraints. A hybrid optimization algorithm consisting of a genetic algorithm and a sequential quadratic programming (SQP) algorithm was selected and used to solve this problem. The proposed method was evaluated by applying it to a thrust allocation problem for a semisubmersible drilling rig. The results indicate that the proposed method can be used as part of a cost-effective strategy for thrust allocation of the rig

Multi-ship collision avoidance control strategy in close-quarters situations: a case study of Dover Strait ferry maneuvering

Multi-ship collision avoidance is challenging in busy waters like the Dover Strait. Usually, ships follow the rules for avoiding collisions which are given by the Convention on the International Regulations for Preventing Collisions at Sea (COLREGS), by the International Maritime Organization (IMO). However, COLREGS can be ambiguous to follow in the close-quarters situations due to the complex crossing scenarios. In that situations, multiple ship avoid collisions with each other is highly dependent upon seamanship and crew’s experience. In this study, we propose a COLREGS-compliant decision making strategy that integrates the human expertise with the artificial intelligent method. A simulation scenario was utilized to validate the effectiveness and feasibility of the proposed method

Does the Aging of the Chinese Population Have an Impact on Outward Foreign Direct Investment?

Given the progression of population aging in China, does the diminishing demographic dividend boost the promotion of investment abroad in the form of outward foreign direct investment (OFDI)? This empirical study focused on the influence of population aging on outward foreign direct investment (OFDI) decisions and its underlying mechanisms. The research found that population aging has a significant positive effect on the level of OFDI. This effect is particularly pronounced in the eastern and central regions, while not statistically significant in the western region. Furthermore, population aging has a significant impact on the factor cost effect and the technological progress effect. The former is characterized by increased labor costs, while the latter is associated with technological advancements. The study confirmed that population aging positively influences OFDI changes through these two mechanisms. The empirical results hold statistically significant after multiple robustness checks. This study holds a significant reference value in advancing the facilitation of high-level opening-up polices and policy coordination to effectively address the challenges posed by population aging

Development of Onboard Decision Supporting System for Ship Docking Operations

Maritime operations inevitably influenced by the wind, wave, sea currents, or other perturbations at sea. Providing decision support for these operations based on historical and real-time data of ship status is thus of great concern in terms of ship safety. However, it is challenging for collecting and analysis large quantities of ship data in real operations. Moreover, the development of an onboard decision support system (DSS) will be a gradual and iterative process subject to extensive testing and simulation. Consequently, the paper presents an integrated simulation framework which provides testing and simulation environment for the DSS development. The system enables navigation data transmission from a well-designed simulator and automatic determining of the safe maneuver of a ship within the framework. The development of DSS is divided into three steps. Firstly, we collect the ship maneuvering data from the simulator and classify them; Then we implement an imitation learning (IL) algorithm to learn an initial policy from the data; Finally, based on the policy, the reinforcement learning (RL) algorithm is used to determine the safe decision for operations. In this way, it could speed up the learning efficiency by extracting more information from available experience. To verify the effectiveness of the proposed integrated simulation framework, in this study, we implemented the proposed DSS in ship docking operation under various environmental disturbances. It is interacted with the simulator to obtain data. By processing these data, it provides the shipmaster with the information about the consequences of the ship maneuvering decisions. The simulation results demonstrate that the proposed DSS could assist the shipmaster in deciding policies and increase the efficiency of decision making

A human-expertise based statistical method for analysis of log data from a commuter ferry

The proposed method in this paper aims to better understand the log data from the commuter ferry. By the method, the mechanism of how the human expertise operates the ferry can be found, and thus help to establish ship intelligence for the autonomous commuting sailing. The log data of sailings with the same departure and arrival ports is of interest in this respect. The method defines different phases of a sailing as different scenarios in terms of the features contained in the collected data. The features are reflected by the ship behavior/response and the ship machinery/actuators. Compared to the typical sailing phases which are distinct to each other, the features can be uncertain when the ferry transfers from the current phase to the sequential. The concept of the transition time window is thus raised to interpret the uncertainty between adjacent phases. Based on the collected data, the human expertise is involved to summarize features and generate empirical criteria for the decomposition. After the whole sailing being split into a sequential-scenario series, statistical heat maps are drawn to illustrate the likelihood site with respect to the collected log data. In practice, log data collected from a customized commuting route in Trondheim are analyzed by the proposed method