HAZARD IDENTIFICATION AND PROBABLISTIC SCENARIO SELECTION FOR SHIP- SHIP COLLISION ACCIDENTS

2021 ◽  
Vol 156 (A1) ◽  
Author(s):  
S. A. M. Youssef ◽  
Y. S. Kim ◽  
J. K. Paik ◽  
F. Cheng ◽  
M. S. Kim
Keyword(s):  
Sampling Technique ◽  
Hazard Identification ◽  
Probability Density Distribution ◽  
Collision Risk ◽  
Near Misses ◽  
Different Types ◽  
Design Loads ◽  
Ship Collision ◽  
Selection For ◽  
Accident Scenarios

In collision risk-based design frameworks it is necessary to accurately define and select a set of credible scenarios to be used in the quantitative assessment and management of the collision risk between two ships. Prescriptive solutions and empirical knowledge are commonly used in current maritime industries, but are often insufficient for innovation because they can result in unfavourable design loads and may not address all circumstances of accidents involved. In this study, an innovative method using probabilistic approaches is proposed to identify relevant groups of ship-ship collision accident scenarios that collectively represent all possible scenarios. Ship-ship collision accidents and near-misses recently occurred worldwide are collated for the period of 21 years during 1991 to 2012. Collision scenarios are then described using a set of parameters that are treated individually as random variables and analysed by statistical methods to define the ranges and variability to formulate the probability density distribution for each scenario. As the consideration of all scenarios would not be practical, a sampling technique is applied to select a certain number of prospective collision scenarios. Applied examples for different types of vessels are presented to demonstrate the applicability of the method.

Hazard Identification and Probablistic Scenario Selection for Shipship Collision Accidents

2014 ◽  
Vol 156 (A1) ◽  
Keyword(s):  
Sampling Technique ◽  
Hazard Identification ◽  
Probability Density Distribution ◽  
Collision Risk ◽  
Near Misses ◽  
Different Types ◽  
Design Loads ◽  
Ship Collision ◽  
Selection For ◽  
Accident Scenarios

In collision risk-based design frameworks it is necessary to accurately define and select a set of credible scenarios to be used in the quantitative assessment and management of the collision risk between two ships. Prescriptive solutions and empirical knowledge are commonly used in current maritime industries, but are often insufficient for innovation because they can result in unfavourable design loads and may not address all circumstances of accidents involved. In this study, an innovative method using probabilistic approaches is proposed to identify relevant groups of ship-ship collision accident scenarios that collectively represent all possible scenarios. Ship-ship collision accidents and near-misses recently occurred worldwide are collated for the period of 21 years during 1991 to 2012. Collision scenarios are then described using a set of parameters that are treated individually as random variables and analysed by statistical methods to define the ranges and variability to formulate the probability density distribution for each scenario. As the consideration of all scenarios would not be practical, a sampling technique is applied to select a certain number of prospective collision scenarios. Applied examples for different types of vessels are presented to demonstrate the applicability of the method.

Probabilistic Selection of Ship-Ship Collision Scenarios

2013 ◽  
Author(s):  
Samy A. M. Youssef ◽  
Jeom K. Paik ◽  
Yang Seop Kim ◽  
Min Soo Kim ◽  
Fai Cheng
Keyword(s):  
Sampling Technique ◽  
Random Variable ◽  
Quantitative Risk Assessment ◽  
Design Stage ◽  
Density Distributions ◽  
Design Loads ◽  
Ship Collision ◽  
Accident Scenarios ◽  
Probability Density Distributions ◽  
Double Hull

Within the framework of quantitative risk assessment and management in the design stage, it is essential to select relevant sets of accidental scenarios, while a huge number of possible scenarios are obvious. The current industry practices are likely based on prescriptive approaches for the most unfavorable accidental scenarios. However, these approaches are often inadequate for obvious reasons because they may result in too large values of design loads in some cases but they may underestimate design loads in other cases. In the present study, an innovative method using probabilistic approaches is suggested to select relevant sets of ship-ship collision accident scenarios which represent all possible ones. Historical database for each of individual collision parameters which is dealt with as a random variable have been collated and are analyzed by statistical methods to characterize the probability density distributions. A sampling technique is then applied to select collision scenarios. Applied examples to a double hull oil tanker are presented to demonstrate the applicability of the developed method.

scholarly journals A Spatiotemporal Statistical Method of Ship Domain in the Inland Waters Driven by Trajectory Data

2021 ◽  
Vol 9 (4) ◽  
pp. 410
Author(s):  
Fan Zhang ◽  
Xin Peng ◽  
Liang Huang ◽  
Man Zhu ◽  
Yuanqiao Wen ◽  
...  
Keyword(s):  
Statistical Method ◽  
Yangtze River ◽  
Domain Size ◽  
Inland Waters ◽  
The Yangtze River ◽  
Trajectory Data ◽  
Different Types ◽  
Dry Seasons ◽  
Ship Collision ◽  
Shape And Size

In this study, a method for dynamically establishing ship domain in inland waters is proposed to help make decisions about ship collision avoidance. The surrounding waters of the target ship are divided to grids and then calculating the grid densities of ships in each moment to determine the shape and size of ship domain of different types of ships. At last, based on the spatiotemporal statistical method, the characteristics of ship domains of different types of ship in different navigational environments were analyzed. The proposed method is applied to establish ship domains of different types of ship in Wuhan section of the Yangtze River in January, February, July, and August in 2014. The results show that the size of ship domain increases as the ship size increases in each month. The domain size is significantly influenced by the water level, and the ship domain size in dry seasons is larger than in the wet seasons of inland waters.

scholarly journals An Estimation of Ship Collision Risk Based on Relevance Vector Machine

2021 ◽  
Vol 9 (5) ◽  
pp. 538
Author(s):  
Jinwan Park ◽  
Jung-Sik Jeong
Keyword(s):  
Machine Learning ◽  
Decision Making ◽  
Risk Estimation ◽  
Good Method ◽  
Relevance Vector Machine ◽  
Machine Learning Algorithms ◽  
Support Vector ◽  
Collision Risk ◽  
Estimation Model ◽  
Ship Collision

According to the statistics of maritime collision accidents over the last five years (2016–2020), 95% of the total maritime collision accidents are caused by human factors. Machine learning algorithms are an emerging approach in judging the risk of collision among vessels and supporting reliable decision-making prior to any behaviors for collision avoidance. As the result, it can be a good method to reduce errors caused by navigators’ carelessness. This article aims to propose an enhanced machine learning method to estimate ship collision risk and to support more reliable decision-making for ship collision risk. In order to estimate the ship collision risk, the conventional support vector machine (SVM) was applied. Regardless of the advantage of the SVM to resolve the uncertainty problem by using the collected ships’ parameters, it has inherent weak points. In this study, the relevance vector machine (RVM), which can present reliable probabilistic results based on Bayesian theory, was applied to estimate the collision risk. The proposed method was compared with the results of applying the SVM. It showed that the estimation model using RVM is more accurate and efficient than the model using SVM. We expect to support the reasonable decision-making of the navigator through more accurate risk estimation, thus allowing early evasive actions.

scholarly journals Improving Near Miss Detection in Maritime Traffic in the Northern Baltic Sea from AIS Data

2021 ◽  
Vol 9 (2) ◽  
pp. 180
Author(s):  
Lei Du ◽  
Osiris A. Valdez Banda ◽  
Floris Goerlandt ◽  
Pentti Kujala ◽  
Weibin Zhang
Keyword(s):  
Baltic Sea ◽  
Perceived Risk ◽  
Maritime Transportation ◽  
Near Miss ◽  
Automatic Identification ◽  
Identification System ◽  
Collision Risk ◽  
Ship Collision ◽  
The Impact ◽  
Ship Behavior

Ship collision is the most common type of accident in the Northern Baltic Sea, posing a risk to the safety of maritime transportation. Near miss detection from automatic identification system (AIS) data provides insight into maritime transportation safety. Collision risk always triggers a ship to maneuver for safe passing. Some frenetic rudder actions occur at the last moment before ship collision. However, the relationship between ship behavior and collision risk is not fully clarified. Therefore, this work proposes a novel method to improve near miss detection by analyzing ship behavior characteristic during the encounter process. The impact from the ship attributes (including ship size, type, and maneuverability), perceived risk of a navigator, traffic complexity, and traffic rule are considered to obtain insights into the ship behavior. The risk severity of the detected near miss is further quantified into four levels. This proposed method is then applied to traffic data from the Northern Baltic Sea. The promising results of near miss detection and the model validity test suggest that this work contributes to the development of preventive measures in maritime management to enhance to navigational safety, such as setting a precautionary area in the hotspot areas. Several advantages and limitations of the presented method for near miss detection are discussed.

scholarly journals Pengaruh Substitusi Tepung Kedelai terhadap Kualitas Biskuit

Media Wisata ◽  
2021 ◽  
Vol 16 (2) ◽  
Author(s):  
Heni Susilowati ◽  
Adi Prabowo
Keyword(s):  
Sampling Technique ◽  
Subjective Assessment ◽  
Soy Flour ◽  
P Value ◽  
Homogeneity Test ◽  
Soybean Flour ◽  
Normality Test ◽  
Significant Difference ◽  
Different Types ◽  
Sensory Tests

The research entitled The Effect of Substitution of Soybean Flour on Biscuit Quality is a type of research using a quantitative approach with an experimental method. The purpose is to know the effect of quality biscuits with soybean flour substitution with a different percentage that is equal to 50%, 25% and 10% viewed from the aspect of colour, flavour, aroma and texture. The experiments used 3 different types of treatment on the percentage of soy flour used ie, biscuit A with 50% soy flour, biscuit B with 25% soy flour, and C biscuits with 10% soy flour. Methods of data collection using subjective assessment of sensory tests taken from the results of a panellist assessment that includes assessment of colour, aroma, taste and texture on biscuits. The panel of researchers was 30 people taken by random sampling technique with considerations that included panellist knowledge about the sensory properties of biscuits in general. Methods of data analysis to test the hypothesis using the analysis of single classification variables and Tukey test, previously conducted precariat test that is homogeneity test and normality test. The result of the research with Anova test seen from the color aspect shows that (significant value (p-value) <0,05 = 0,000 <0,05) shows that there is significant difference from three substitution biscuit substitution biscuit, while from aroma aspect shows significant (p-value) <0,05 = 0,008 <0,05) indicated that there were significant differences from the three soybean substitution biscuit samples. Seen from the texture aspect showed (significant value (p-value) <0,05 = 0,000 <0,05) indicated that there was significant difference from three sample of soybean substitution biscuit. In terms of taste taste (significant value (p-value) <0.05 = 0.005 <0.05) indicates that there are significant differences from the three soybean substitution biscuit samples.

scholarly journals Parental effects and the evolution of phenotypic memory

2015 ◽  
Author(s):  
Bram Kuijper ◽  
Rufus A Johnstone
Keyword(s):  
Local Environment ◽  
Parental Effects ◽  
Bet Hedging ◽  
Changing Environments ◽  
Structured Population ◽  
Different Types ◽  
Parental Phenotype ◽  
Selection For ◽  
Nongenetic Inheritance

Abstract Despite growing evidence for nongenetic inheritance, the ecological conditions that favor the evolution of heritable parental or grandparental effects remain poorly understood. Here, we systematically explore the evolution of parental effects in a patch-structured population with locally changing environments. When selection favors the production of a mix of offspring types, this mix differs according to the parental phenotype, implying that parental effects are favored over selection for bet-hedging in which the mixture of offspring phenotypes produced does not depend on the parental phenotype. Positive parental effects (generating a positive correlation between parental and offspring phenotype) are favored in relatively stable habitats and when different types of local environment are roughly equally abundant, and can give rise to long-term parental inheritance of phenotypes. By contrast, unstable habitats can favor negative parental effects (generating a negative correlation between parental and offspring phenotype), and under these circumstances even slight asymmetries in the abundance of local environmental states select for marked asymmetries in transmission fidelity.

scholarly journals Influence Assessment of the Information Concerning the Bearing Type of Axle Box of Cars on the Automatic Classification Accuracy of Heated Boxes

2021 ◽  
pp. 5-14
Author(s):  
V. V Burchenkov
Keyword(s):  
Density Distribution ◽  
Probability Density ◽  
Heating Temperature ◽  
Threshold Value ◽  
Probability Density Distribution ◽  
Practical Implementation ◽  
System Of Equations ◽  
Average Value ◽  
Optimal Thresholds ◽  
Different Types

Purpose. The main purpose of the work is to determine and classify the heated cars’ boxes based on the probability of appearance of roller and cassette type boxes in the classes of heated and overheated boxes, as well as the laws of probability density distribution of the recognition signs of normally heated and overheated roller and cassette type boxes. Methodology. The operation features of freight cars with cassette type axle boxes with increased operating heating have been investigated. The methodology of assessing the probability of recognition errors was proposed, which takes into account the fact that sets of normally heated and overheated boxes consist of subsets of boxes with different types of bearings. A system of equations is obtained, the roots of which represent еру values that minimize the recognition probability of the errors of the heated boxes. Findings. It was found out that with some methods of determining the bearing type, for example, by the average value of the ranges of thermal image for each car, the probability of erroneous selection may depend on the probability density distribution of the sign for bearings of different types and the threshold value of this sign. The optimal thresholds for detecting the overheated roller boxes in comparison with the optimal thresholds for detecting overheated cassette boxes were determined. It has been established that the pass of an overheated cassette bearing, provided that the type of bearing is determined correctly, is less likely to lead to an accident than if the cassette box is classified as a roller box. The rejection criteria of axle boxes according to their heating temperature difference on one of the wheel set axis for three variants of settings of the alarm system according to an arrangement of multipurpose complexes of technical means (CTM) were formulated. The practical implementation of this method of adjusting the CTM settings for the Minsk branch of the Belarusian Railways was demonstrated. Originality. A system of equations is obtained, which allows finding the optimal values of temperature thresholds for the detection of overheated roller and cassette boxes under the assumption that the error probabilities in the selection of boxes by their types are known and constant. Practical value. The developed method of adjusting the alarm settings of CTM makes it possible to significantly reduce unjustified train delays and the number of car uncouplings.

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