The cause of human fatigue and scenario analysisin the process of marine transportation

The framework of fatigue factors is constructed to reduce the number of maritime accidents caused by human fatigue.Based on the study of maritime human fatigue,by screening and classifying it,there are 15 fatigue factors,which can be classified into 4 types:sleep,rest and rhythm;work factors;personal conditions;environmental factors.These factors are regarded as the variables for constructing scenarios.The importance,uncertainty,influence and dependence of variables and variable pairs were assessed by using morphological analysis,quantitative scales and correlation matrices.Ship movement and workload are selected as the two key variables,which are regarded as the axes of generating scenarios.One of the scenarios is selected as the typical scenario to illustrate the relationship between the causes of fatigue.Then,the analysis framework is constructed according to the fatigue factors relationship,and several potential solutions are proposed,which include the development of foresighted and flexible work plans,and the application of wearable facilities to improve monitoring and assessment systems.The proposed framework lays a theoretical foundation for studying maritime human fatigue,and scenario analysis can provide an effective strategy for reducing crews'fatigue.

The Impact of Privatization on Terminal Efficiency: A Case Study of Tema Port

Port and terminal efficiency are of utmost importance to the container shipping industry due to their significance in enhancing the competitive advantage of ports within a region. Consequently, there have always been notable variations of studies around it. This paper analyzes the impact of privatization on terminal efficiency using the Port of Tema as a Case Study. The main objective of this paper is to analyze the efficiency trends of the public and private terminals in the port over the years. To achieve this objective, DEA-CCR methodology was employed to calculate the annual technical efficiency trends of the private and public terminals using four input variables and three output variables. The main results of the paper indicated that the public and private terminals were efficient for multiple years. However, the efficiency scores over the years demonstrated inconsistency, exhibiting notable fluctuations. The findings of this study will aid policymakers across the region on policies relating to the efficiency and ownership structure of ports and terminals.

Neutrosophic Adaptive Clustering Optimization in Genetic Algorithm and Its Application in Cubic Assignment Problem

In optimization theory,the adaptive control of the optimization process is an important goal that people pursue.To solve this problem,this study introduces the idea of neutrosophic decision-making into classical heuristic algorithm,and proposes a novel neutrosophic adaptive clustering optimization thought,which is applied in a novel neutrosophic genetic algorithm(NGA),for example.The main feature of NGA is that the NGA treats the crossover effect as a neutrosophic fuzzy set,the variation ratio as a structural parameter,the crossover effect as a benefit parameter and the variation effect as a cost parameter,and then a neutrosophic fitness function value is created.Finally,a high order assignment problem in warehousemanagement is taken to illustrate the effectiveness of NGA.

Novel Distance Measures on Hesitant Fuzzy Sets Based on Equal-Probability Transformation and Their Application in Decision Making on Intersection Traffic Control

The purpose of this study is to reduce the uncertainty in the calculation process on hesitant fuzzy sets(HFSs).The innovation of this study is to unify the cardinal numbers of hesitant fuzzy elements(HFEs)in a special way.Firstly,a probability density function is assigned for any given HFE.Thereafter,equal-probability transformation is introduced to transform HFEs with different cardinal numbers on the condition into the same probability density function.The characteristic of this transformation is that the higher the consistency of the membership degrees in HFEs,the higher the credibility of the mentioned membership degrees is,then,the bigger the probability density values for them are.According to this transformation technique,a set of novel distance measures on HFSs is provided.Finally,an illustrative example of intersection traffic control is introduced to show the usefulness of the given distance measures.The example also shows that this study is a good complement to operation theories on HFSs.

Efficiency of Moroccan Seaports: Application of DEA Using Window Analysis

The efficiency of 8 seaports in the Kingdom of Morocco region was evaluated. Two associated studies were conducted based on data collected for 4 years (2014-2017), Standard Data Envelopment Analysis (DEA) method was used in the first analysis through CCR and BCC models, and thus a scale of efficiency analysis was used in a second analysis. By using both methods, enhanced insight into the efficiency situation is collected, proving subsequently that a majority of the container ports and terminals in the Kingdom of Morocco are found to be technically inefficient. The research concludes through returns to scale method how port resources should be utilized in the aim to impulse inefficient ports perform better.

Adaptive sampling and reconstruction for gradient-domain rendering

Gradient-domain rendering estimates finite difference gradients of image intensities and reconstructs the final result by solving a screened Poisson problem,which shows improvements over merely sampling pixel intensities.Adaptive sampling is another orthogonal research area that focuses on distributing samples adaptively in the primal domain.However,adaptive sampling in the gradient domain with low sampling budget has been less explored.Our idea is based on the observation that signals in the gradient domain are sparse,which provides more flexibility for adaptive sampling.We propose a deep-learning-based end-to-end sampling and reconstruction framework in gradient-domain rendering,enabling adaptive sampling gradient and the primal maps simultaneously.We conducted extensive experiments for evaluation and showed that our method produces better reconstruction quality than other methods in the test dataset.

TESTS AND APPLICATIONS OF A BOUSSINESQ MODEL WITH AMBIENT CURRENT

A new type Boussinesq model is proposed and applied for wave propagation in a wave flume of uniform depth and over a submerged bar with current present or absent,respectively.Firstly,for the propagation of monochromatic incident wave with current absent,the Boussinesq model is tested in its complete form,and in a form without the introduction of utility velocity variables.It is validated that the introduction of utility velocity variables can improve the characteristics of velocity field,dispersion and nonlinearity.Both versions of the Boussinesq models are of higher accuracy than the fully-nonlinear fourth-order model,which is one of the best forms among the existing traditional Boussinesq models that do not incorporate breaking mechanism in one dimension.Secondly,the Boussinesq model in its complete form is applied to simulating the propagation of bichromatic incident waves with current present or absent,respectively,and the modeled results are compared to the analytical ones or the experimental ones.The modeled results are reasonable in the case of inputting bichromatic incident waves with the strong opposing current present.

A multi-objective model for cordon-based congestion pricing schemes with nonlinear distance tolls

Congestion pricing is an important component of urban intelligent transport system.The efficiency,equity and the environmental impacts associated with road pricing schemes are key issues that should be considered before such schemes are implemented.This paper focuses on the cordon-based pricing with distance tolls,where the tolls are determined by a nonlinear function of a vehicles' travel distance within a cordon,termed as toll charge function.The optimal tolls can give rise to:1) higher total social benefits,2) better levels of equity,and 3) reduced environmental impacts(e.g.,less emission).Firstly,a deterministic equilibrium(DUE) model with elastic demand is presented to evaluate any given toll charge function.The distance tolls are non-additive,thus a modified path-based gradient projection algorithm is developed to solve the DUE model.Then,to quantitatively measure the equity level of each toll charge function,the Gini coefficient is adopted to measure the equity level of the flows in the entire transport network based on equilibrium flows.The total emission level is used to reflect the impacts of distance tolls on the environment.With these two indexes/measurements for the efficiency,equity and environmental issues as well as the DUE model,a multi-objective bi-level programming model is then developed to determine optimal distance tolls.The multi-objective model is converted to a single level model using the goal programming.A genetic algorithm(GA) is adopted to determine solutions.Finally,a numerical example is presented to verify the methodology.

Real-time routing control design for traffic networks with multi-route choices

This work considers those road networks in which there are multi-route choices for bifurcation-destination(or origin-destination) pairs, and designs a real-time variable message sign(VMS)-based routing control strategy in the model predictive control(MPC) framework. The VMS route recommendation provided by the traffic management authority is directly considered as the control variable, and the routing control model is established, in which a multi-dimensional control vector is introduced to describe the influence of route recommendations on flow distribution. In the MPC framework, a system optimum routing strategy with the constraints regarding drivers' acceptability with recommended routes is designed, which can not only meet the traffic management authority's control requirement but also improve drivers' satisfaction with the route guidance system. The simulation carried out shows that the proposed routing control can effectively mitigate traffic congestion, reduces followers' time delay, and improves drivers' satisfaction with routing control in road networks.

Scaling Behavior of Bulk Freight Rate Volatility Before and After Noise Reduction

Analysis of freight rate volatility characteristics is a hot topic after year 2008 due to the effect of financial crisis in marine transportation.In this paper,we analyze the bulk freight rate index by detrended fluctuation analysis(DFA) method and discover the scaling behavior.Switching points(SPs),as the indicators of scaling behavior,can be eliminated after Vondr′ak noise reduction technique.Therefore,we conclude that highfrequency noise is the cause of SP.

An intermodal transportation geospatial network modeling for containerized soybean shipping

Containerized shipping is a growing market for agricultural exports,particularly soybeans.In order to understand the optimal strategies for improving the United States’economic competitiveness in this emerging market,this research develops an intermodal transportation network modeling framework,focusing on U.S.soybean container shipments.Built upon detailed modal cost analyses,a Geospatial Intermodal Freight Transportation(GIFT)model has been developed to understand the optimal network design for U.S.soybean exports.Based on market demand and domestic supply figures,the model is able to determine which domestically produced soybeans should go to which foreign markets,and by which transport modes.This research and its continual studies,will provide insights into future policies and practices that can improve the transportation efficiency of soybean logistics.

Zero-Inflated Exponential Distribution of Casualty Rate in Ship Collision

There are two weaknesses in current researches into human casualty of ship collision.One is that the range of injuries or fatalities is restricted to the maximum number of casualties in a particular sample,which may not cover all the possible numbers of casualties in the future.International Maritime Organization(IMO)employed the injured or dead percentage of all the persons on board to represent casualties,but it only provided several discrete values to quantify human losses in different scenarios.The other is that the assumption that the distributions of the injuries or fatalities follow certain distribution,such as negative binomial and Poisson distributions is left to be statistically tested.Firstly,this study considers casualty rate,including injury and fatality rates,as random variables;the interval of the variables are from 0 to 1.Then,the distributions of the variables are investigated using historical data.From historical data,we can find that there are many zeros.Zeroinflated models are proved to be effective in processing data with inflated zeros.Furthermore,the probability density of the variables decreases rapidly as the casualty rate becomes larger.Thus,zero-inflated exponential distribution is assumed to fit the data.The parameters of zero-inflated exponential distribution are calibrated by maximum likelihood estimation(MLE)method.Finally,the assumption is tested by chi-square test.The zeroinflated exponential distribution can be used to generate human losses as a part of consequences in the simulation of ship collision risk.

A Stackelberg game model with tax for regional air pollution control

The command-and-control regulation is likely inefficient and costly.This study investigates a regional pollution control scheme with tax(RPCST)under which the central government sets the tax rate under a given pollutant reduction quota and local governments determine their pollution removal rates based on the central government’s policy.First,a one-leader-multi-follower(OLMF)Stackelberg game model is formulated,in which the central government is the leader and the local governments are the followers.Then,a procedure based on bilevel programming and relaxation method is applied to solve the OLMF model.Finally,a case study analyzing the SO2 reduction of the Yangtze River Delta in China is conducted to demonstrate the effectiveness of the RPCST.The results show that RPCST works better than the current command-andcontrol scheme.Our analysis provides a guideline for governments to design optimal tax schemes to effectively solve the regional air pollution crisis.