Predicting Near-Bed Sediment Transport Through Particle Image Velocimetry,
2023
Florida Institute of Technology
Predicting Near-Bed Sediment Transport Through Particle Image Velocimetry, Caroline Hoch
Theses and Dissertations
Erosion and accretion are coastal processes that directly affect the safety of coastal communities. Dimensionless parameters, such as the Shields and Ursell number, have historically been used to predict sediment motion in the nearshore region based on shear stress and wave linearity. This study uses particle image velocimetry to measure the velocity field of sediment within a wave flume and calculate these parameters for various wave profiles. Five regular wave trials and five irregular wave trials were run within the wave flume at varying depths to model how net transport changes as waves approach the shoreline. An instantaneous Shields number …
Energy-Specific Greenhouse Gas Emissions Measurements From 2-Stroke Marine Diesel Engine Using Liquefied Natural Gas,
2023
AVL List GmbH
Energy-Specific Greenhouse Gas Emissions Measurements From 2-Stroke Marine Diesel Engine Using Liquefied Natural Gas, Kang-Ki Lee, Wilfried Hochegger, Alessandro Schonborn
Articles
This study reports the energy specific air emissions from a diesel-cycle high pressure injection dual fuel engine for operation on liquefied natural gas and heavy fuel oil. An experiment at sea was performed onboard a bulk carrier during commercial voyages, to measure the efficiency of the engine and to measure air emissions relevant to air pollution and climate impact for operation on both fuels. The measurements showed that the energy conversion efficiency of the engine was higher for operation on liquefied natural gas because its lower NOx emissions permitted the use of a higher effective compression ratio whilst meeting the …
Assessing High Dynamic Range Imagery Performance For Object Detection In Maritime Environments,
2023
Embry-Riddle Aeronautical University
Assessing High Dynamic Range Imagery Performance For Object Detection In Maritime Environments, Erasmo Landaeta
Doctoral Dissertations and Master's Theses
The field of autonomous robotics has benefited from the implementation of convolutional neural networks in vision-based situational awareness. These strategies help identify surface obstacles and nearby vessels. This study proposes the introduction of high dynamic range cameras on autonomous surface vessels because these cameras capture images at different levels of exposure revealing more detail than fixed exposure cameras. To see if this introduction will be beneficial for autonomous vessels this research will create a dataset of labeled high dynamic range images and single exposure images, then train object detection networks with these datasets to compare the performance of these networks. …
Effects Of Various Dietary Carbohydrate Sources On The Growth Performance And Body Composition Of The Dog Conch, Laevistrombus Canarium,
2023
Department of Aquatic Biosciences, National Chiayi University, Chiayi, 600, Taiwan
Effects Of Various Dietary Carbohydrate Sources On The Growth Performance And Body Composition Of The Dog Conch, Laevistrombus Canarium, Jen-Hong Chu
Journal of Marine Science and Technology–Taiwan
This study investigates the effects of dietary supplementation with various carbohydrate sources on the growth and dietary nutrient utilization efficiency of a 0.72-g dog conch, Laevistrombus canarium. Five treatment diets had supplementation with alpha-starch (Sta), dextrin (Dex), pullulan gum (Pg), xanthan gum (Xg), and carboxymethyl cellulose (CMC). At the end of the feeding trial, the best growth performance (weight gain, 442.23%) and diet efficiency (protein efficiency ratio, 1.25, and feed conversion ratio [FCR], 2.04) were exhibited by the dog conch fed the Sta diet, whereas the lowest growth performance was observed in the dog conch fed the Xg and CMC …
Cost Advantages Of Far East/Europe Trunk Route Deployment With Port Selection In East Asia,
2023
Department of Shipping and Transportation Management, Dean of Marine Science and Technology, National Kaohsiung University of Science and Technology, Taiwan
Cost Advantages Of Far East/Europe Trunk Route Deployment With Port Selection In East Asia, Tai Hui-Huang, Chang Chin-Wei
Journal of Marine Science and Technology–Taiwan
To cater to the gradually increasing sizes of ships, several traditional container ports in East Asia built deep-water wharves to attract shipping carriers to berth, a decision that is considered highly reasonable because it allows for shipping carriers to gain a cost advantage. For traditional Far East/Europe (F/E) trunk routes, shipping carriers must deploy vessels that are large enough at hub ports to maintain low transshipment costs. However, for a port to attract shipping carriers, it should be able to first meet the cargo demand of these carriers. The port would also need to improve the loading ratio to enjoy …
Influence Of Vacuum Condition On Rapid Chloride Migration (Rcm) Test For Chloride Penetration Resistance Of Concrete,
2023
Department of Harbor and River Engineering, National Taiwan Ocean University, 2 Pei-Ning Road, Keelung 20224, Taiwan
Influence Of Vacuum Condition On Rapid Chloride Migration (Rcm) Test For Chloride Penetration Resistance Of Concrete, Chih-Yen Lin, Chun-Fu Chang, Chung-Chia Yang
Journal of Marine Science and Technology–Taiwan
NT Build 492 regulates that the pressure be set at 7.5–37.5 torr and be maintained for 3 h for vacuum processing. This large range of acceptable vacuum pressure is awkward for research, and 3 h of pump-down time may be excessive. In this study, vacuum conditions were divided into vacuum pressure and pump-down time groups: various vacuum pressures and pump-down times were used to preprocess specimens to explore the effect of vacuum conditions on the RCM test. The salt ponding test was also conducted to identify the optimal vacuum conditions. It is shown that the relationship between vacuum pressure and …
Exhaust Noise Elimination Using Silencers Fortified With Perforated Tubes, Extended Tubes, Penetrable Resin Inlet And Orifice Plate,
2023
Department of Mechanical and Materials Engineering, Tatung University, ROC
Exhaust Noise Elimination Using Silencers Fortified With Perforated Tubes, Extended Tubes, Penetrable Resin Inlet And Orifice Plate, Min-Chie Chiu, Ho-Chih Cheng
Journal of Marine Science and Technology–Taiwan
Pneumatic equipment in marine diesel engine and associated piping system often emit extremely high level of noises when releasing pressure. Concerning the crew’s hearing health, discovering an efficient noise silencing device becomes essential. A silencer fortified with extended tubes, perforated tubes, orifice plate, and penetrable resin inlet is presented in order to competently dampen the blown-up noises. A simplified objective function by means of FEM, Artificial Neural Networks (ANNs), and a Genetic Algorithm (GA) is established to enable the numerical calculation when using a finite element method. Three silencer designs, silencer A (with element A, a penetrable resin inlet), B …
Deep Learning–Based, Oceantdlx Sea Ice Detection Model For Sar Image,
2023
Shandong University of Science and Technology, Qingdao, China.
Deep Learning–Based, Oceantdlx Sea Ice Detection Model For Sar Image, Liu Lin, Li Wanwu, Li Hang, Sun Yi
Journal of Marine Science and Technology–Taiwan
This study constructs four deep-learning OceanTDLx series models and uses a WinR-AdaGrad gradient descent algorithm to train and optimize the constructed models. Through an analysis of the loss, accuracy, and time consumption of the four models (i.e., OceanTDL2, OceanTDL3, OceanTDL5 and OceanTDL8), we reveal that the models’ performance does not improve when the number of layers is increased and that OceanTDL5 provides the optimal performance. OceanTDL5 is compared with OceanTDA9 (a model that we previously constructed), and the curves for training loss_batch and training accuracy_batch indicate that OceanTDL5 is more suitable than OceanTDA9 for detecting distributed targets, particularly semi-melted sea …
Application Of Unmanned Aerial Vehicle–Based Infrared Images In Determining Characteristics Of Sea Surface Temperature Distribution,
2023
Assistant Professor, Department of Shipping Technology, College of Maritime, National Kaohsiung University of Science and Technology
Application Of Unmanned Aerial Vehicle–Based Infrared Images In Determining Characteristics Of Sea Surface Temperature Distribution, Hsing-Yu Wang, Hui-Ming Fang, Yun-Chih Chiang
Journal of Marine Science and Technology–Taiwan
This study investigated the temperature field of a body of water by using rotary-wing unmanned aerial vehicles (DJI Mavic 2 Enterprise Dual) comprising visible light and infrared cameras to determine sea temperature distribution. With a flight height of 150 m, image overlap of 80%, and image resolution of 4.75 cm/pixel, the proposed method was more effective than the conventional portable conductivity–temperature–depth device in rapidly measuring sea surface temperature and determining sea temperature distribution. The discharged heated water of the Hoping Power Plant traveled 100–330 m from the wastewater outfall and then gradually diffused in the range of 100–490 m before …
Combustion Of Scrap Waste Tires Of A Cogeneration Plant,
2023
Department of Marine Engineering, National Kaohsiung University of Science and Technology, Taiwan, R.O.C
Combustion Of Scrap Waste Tires Of A Cogeneration Plant, Chin-Ko Yeh, Rong-Hua Yeh
Journal of Marine Science and Technology–Taiwan
Various fuels can be used in circulating fluidized bed (CFB) boilers. In this study, the thermal and economic performance was investigated for three CFB fuels—heavy fuel oil, coal, and waste tire scraps—used in a cogeneration plant. The plant comprised a CFB boiler, a single-cylinder steam-extraction turbine, and a generator. Tire scrap combustion generated the most power per ton during peak hours: approximately 27.5% more than that generated using heavy oil and 42.3% more than when coal was employed; it also resulted in higher boiler efficiency during peak operation than coal (1.2% higher) or heavy oil (12.6% higher). The net plant …
Freespan Analysis For Subsea Pipeline Integrity Management Strategy,
2023
Universitas Indonesia
Freespan Analysis For Subsea Pipeline Integrity Management Strategy, Nurul Hadi, Muhammad Helmi, Edo Cathaputra, Dedi Priadi, Donanta Dhaneswara
Journal of Materials Exploration and Findings
Abstract. Over a rough seabed or on seabed subject to scour, freespans can occur when contact between a subsea pipeline and the seabed is lost over an acceptable distance. When this exceeds the allowable freespan length, design stresses can be exceeded, and a vortex induced vibration (VIV) response can be initiated, resulting in the risk of fatigue failure. If this is not predicted and controlled properly, it will affect pipeline integrity, leading to expensive rectification and intervention work. Freespan analysis consisted primarily of a screening check in which the as-found freespans from Remotely Operated Vehicle (ROV) or multibeam Side …
A Methodology For Statistical Mean Wave Climate Regime Characterisation In Oceanic Islands: The Case Of The Southern Coast Of Tenerife,
2023
School of Doctoral and Postgraduate Programs, University of La Laguna, La Laguna, S/C Tenerife, Canary Island, 38200, Spain.
A Methodology For Statistical Mean Wave Climate Regime Characterisation In Oceanic Islands: The Case Of The Southern Coast Of Tenerife, Emilio Megías, Manuel García-Román
Journal of Marine Science and Technology–Taiwan
Oceanic islands of volcanic origin tend to have peculiar characteristics, such as: exposure to many wave directions; grouping in archipelagos; steep coastal slopes; and small coastal shelves. All these features require certain considerations in wave climate studies. These types of studies, when wave spectra are not available and have to be performed with parametric data, can be unreliable without an adequate systematic treatment. In this work we propose a methodology consisting of pre-classification according to the peak period and subsequent separation into different sectors according to the geographical fetch. The island of Tenerife is the case study, and in particular …
Context-Dependent Data-Envelopment-Analysis-Based Efficiency Evaluation Of Coastal Ports In China Based On Social Network Analysis,
2023
School of Business, Nanjing Audit University, Nanjing 211815, Nanjing, P.R. China
Context-Dependent Data-Envelopment-Analysis-Based Efficiency Evaluation Of Coastal Ports In China Based On Social Network Analysis, Yu Yu, Dai-Peng Ma, Guo-Ya Gan
Journal of Marine Science and Technology–Taiwan
An emerging trend in performance evaluation is combining social network analysis methods with data envelopment analysis (DEA) models and using network centrality methods to distinguish DEA results. One study employed an input-oriented variable-returns-to-scale DEA model to address referent decision-making units and the corresponding lambda values to construct a network. This study referenced the literature and improved on the use of DEA weight sets to construct a network. We employed a context-dependent DEA model to delineate multiple effective frontier planes, aggregate the reference set relationships on each frontier plane to construct a network relationship matrix, and assess the influences of the …
Research On Improving The Salary Structure Of Port State Control Officers In Taiwan,
2023
North Taiwan Maritime Affairs Center, Maritime and Port Bureau, Ministry of Transportation and Communications, Keelung 200202, Taiwan
Research On Improving The Salary Structure Of Port State Control Officers In Taiwan, Te-Yi Chang, Wen-Chih Ho, Chung-Ping Liu, Yung-Wei Chen
Journal of Marine Science and Technology–Taiwan
The implementation of port state control (PSC) has been challenging in Taiwan due to the lack of port state control officers (PSCOs), and foreign ships berthing at ports in Taiwan that cannot be effectively inspected. PSCOs of Taiwan are subordinate to the public service system and restrained by the number of personnel by the Executive Yuan. Compared with similar professions, their salaries are significantly different from those of the industry, making recruiting and retaining PSCOs a difficult task. Accordingly, this study improved the salary structure of PSCOs by conducting field interviews with existing PSCOs in Taiwan and applying the Fuzzy-AHP …
Numerical Analysis Of Silencer With A Coiled Tube And Straight Perforated Tube Using Fem,
2023
Department of Mechanicaland Materials Engineering, Tatung University, ROC.
Numerical Analysis Of Silencer With A Coiled Tube And Straight Perforated Tube Using Fem, Min-Chie Chiu, Ho-Chih Cheng
Journal of Marine Science and Technology–Taiwan
Marine diesel engine is essential on a ship, but emits extremely loud noise harmful to human hearing. Therefore, it is mandatory to use silencers to reduce the venting noise of the marine diesel engine. An advanced silencer with a new acoustical element of a curved tube, along with perforated holes, is presented to suppress the noise wave. To predict the silencer's acoustical performance for high-order waves, a finite element model was built using COMSOL. The influence of the silencer's noise reduction ability was investigated by exploring sensitivity using acoustical simulations on COMSOL, regarding the silencer's geometric factors. The results proved …
Abundance And Distribution Of Fish Larvae In The Central Coast Of The Algerian Sea,
2023
National Center for Research and Development of Fisheries and Aquaculture (CNRDPA)
Abundance And Distribution Of Fish Larvae In The Central Coast Of The Algerian Sea, Etsouri Mohamed, Khames Ghollame Ellah Yacine, Seridji Rabea
Journal of Marine Science and Technology–Taiwan
This study was conducted on a seasonal basis in five (5) stations along the central Algerian coast between April 2013 and April 2014 aboard professional fishing boats. Horizontal plankton tows with a WP2-type net were used to collect ichthyoplankton samples. At each station, temperature, salinity, and chlorophyll-a levels were measured. We identified the larvae of 18 species from 11 different families by sorting ichthyoplankton (Clupeidae, Engraulidae, Gobidae, Gonostomatidae, Mugilidae, Myctophidae, Scombridae, Sparidae, Carangidae, Labridae, Blennidae). Redundancy analysis (RDA) was used to determine the relationship between the abundance of harvested larvae and environmental variables. The results show a clear dominance of …
Effects Of Direct Water Injection On The Nitrogen Oxide Emission Characteristics Of Marine Diesel Engines,
2023
Department of Naval Architecture and Marine Engineering, Faculty of Engineering, Alexandria University, Alexandria 21544, Egypt
Effects Of Direct Water Injection On The Nitrogen Oxide Emission Characteristics Of Marine Diesel Engines, Mahmoud Abdelnaser Saadeldin, M. M. Elgoharya, Maged Abdelnaby, Mohamed R. Shouman
Journal of Marine Science and Technology–Taiwan
This study examines the issue of diesel emissions from vehicles and vessels and their impact on environmental degradation with a focus on nitrogen oxide (NOx) emissions and their contribution to air pollution-related deaths worldwide. The novelty of this work is the use of computational fluid dynamics simulations to investigate the effectiveness of water addition for reducing NOx emissions. This study considers two methods of water addition, i.e., injection of water and air into a combustion chamber and mixing of water with fuel before injection. Adding water to air systems at 10% and 20% ratios reduces NOx emissions by 5% and …
Predefined-Time Neural Sliding Mode Control Based Trajectory Tracking Of Autonomous Surface Vehicle,
2023
College of Navigation, Jimei University, Xiamen 361021, Fujian,China
Predefined-Time Neural Sliding Mode Control Based Trajectory Tracking Of Autonomous Surface Vehicle, Han Xue, Shulin Li
Journal of Marine Science and Technology–Taiwan
With the progress and development of modern industry, it is urgent to develop a more general and mature predefined time control theory system for uncertain nonlinear systems and apply it to practical engineering systems. Therefore, a novel predefined-time sliding mode control is designed to improve the slow convergence speed of asymptotically convergent controllers and finite-time convergent controllers affected by the initial state of the system. The proposed control approach is proved to converge from the initial value to the balance position using Jensen's inequality and Liapunov theorem. The proposed control method can deal with the ship motion system having six …
Methanol As An Eco-Environmental Alternative Fuel For Ships: A Case Study,
2023
Department of Naval Architecture and Marine Engineering, Faculty of Engineering, Alexandria University, Egypt
Methanol As An Eco-Environmental Alternative Fuel For Ships: A Case Study, Samar K. Sallam, Mohamed M. Elgohary, Ibrahim S. Seddiek
Journal of Marine Science and Technology–Taiwan
Global emissions of Green House Gases and air pollutants are significantly influenced by shipping. Diesel fuel use for energy production is primarily responsible for these emissions. The substitution of traditional marine diesel oil with methanol as a marine fuel is recommended in this study. Moreover, the methanol-diesel dual-fuel engine's environmental and financial benefits are investigated numerically. A cruise passenger ship named Costa Toscana has been evaluated as a case study. Based on the data, the suggested dual-fuel engine reduces emissions of CO2, NOx, SOx, and PM by 25.7%, 38.46%, 45%, and 45%, respectively, with a cost-effectiveness of 286.5, 6645, 268403.4, …
Collision Risk Prediction For Small Ships In South Korea Via Optimization Of Wireless Communication Period,
2023
Ocean Science and Technology School, Korea Maritime and Ocean University, Busan, South Korea, and Korea Institute of Ocean Science and Technology,, Busan, South Korea
Collision Risk Prediction For Small Ships In South Korea Via Optimization Of Wireless Communication Period, So-Ra Kim, Myoung-Ki Lee, Sangwon Park, Dae-Won Kim, Young-Soo Park
Journal of Marine Science and Technology–Taiwan
Since the emergence of COVID-19, there has been a global surge in demand for marine leisure activities. In Korea, the population using marine leisure has risen approximately 192% to 20,406 people, compared to 6,966 people in the year 2000, indicating a continuous growth over the past two decades.. Maritime transportation has become increasingly intricate worldwide due to the development of increasingly autonomous, larger, and faster ships. To effectively address potential hazards in such complex traffic environments, it is imperative to anticipate future scenarios and respond rapidly. However, small vessels account for the highest proportion of marine accidents, exhibit movements that …
