Fresh Water Studies Commons^™

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, 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, 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, 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, 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, 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, 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, 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 …

Path Planning Of Uav Navigation Mark Inspection Using A K-Means Clustering Aca, Jiaqi Li, Weifeng Li, Wenting Zhang

Journal of Marine Science and Technology–Taiwan

With increasing speeds and application of artificial intelligence in the shipping industry, unmanned aerial vehicle (UAV) technology has been applied to navigation mark inspections to improve the inspection efficiency and safety. Aimed at the UAV path planning problem of navigation mark inspection, this paper proposes an improved K-means clustering ant colony algorithm (KCACA) to design the shortest route for UAV navigation mark inspections. First, the K-means algorithm and the UAV maximum flight distance were used to cluster the navigation marks, which were then split into several secondary clusters. Each cluster was regarded as an independent traveling salesman problem to be …

Coastal Traffic Safety Index Based On Marine Accident And Traffic Records, Joohwan Kim, Sang-Lok Yoo

Journal of Marine Science and Technology–Taiwan

In this study, a comprehensive index for evaluating the degree of coastal traffic safety by simultaneously considering marine accident frequency, severity, and traffic volume was considered. To do so, the concept of Equivalent Property Damage Only (EPDO), which is widely used in the road transportation industry, was benchmarked to assess both frequency and severity of accidents. In addition, the total sailing distance of ships was chosen as a variable to explain traffic volume. Finally, a composite performance indicator called "M-EPDO per nautical mile" was built up, enabling the safety performance score for each type of ships in three criteria: on-board …

Inventory Management In Supply Chains With Consideration Of Transportation And Green Technology Cost Under Progressive Carbon Taxation, Ming-Feng Yang, Min-Der Ko, Hung-Jen Tu, Mengru Tu, Jun-Yuan Kuo, Yen-Ting Chao, Shang-Wei Shih

Journal of Marine Science and Technology–Taiwan

Reducing carbon emissions is an important issue in the global supply chain. Governments have formulated different carbon policies to achieve carbon neutrality or emission reduction, in particular, the carbon tax as a policy provides greater certainty about the potential cost to emitters. The Taiwan government is expected to implement the carbon tax policy in 2024 and does not rule out the inclusion of a progressive mechanism which is more effective than a single carbon tax in curbing high carbon emissions Recent studies have also confirmed that a high level and complete carbon tax could encourage companies to invest in green …

Geohash-Based Arrangement Of Live-Fire Exercise Areas Using Ais, Sang-Lok Yoo, Cho-Young Jung

Journal of Marine Science and Technology–Taiwan

Live-fire exercise (LFX) areas at sea threaten the safety of ships, whereas, and indiscriminately abandoned unexploded bombs threaten the lives of fishermen. No statistical or scientific research has been conducted on the appropriate locations for LFX areas. Therefore, this study proposes a method for effectively arranging the LFX areas at sea that considers the safety of passing ships and national security. First, the proposed method classifies ship tracking data collected in the daytime based on the dawn and dusk times of the civil twilight phase. Second, the method uses a Geohash geocoding process to identify whether an LFX area coincides …

Assessing Hierarchical Corporate Sustainability Transition Practices Under Uncertainty: An Approach In The Port And Shipping Industry In Southeast Asia, Mei-Train Yeh, Feng-Ming Tsai, Taufik Kurrahman

Journal of Marine Science and Technology–Taiwan

The port and shipping industry in Southeast Asia has experienced significant development in response to the increasing demand for maritime logistics and transportation services. However, this expansion has resulted in notable social and environmental impacts. Consequently, it is imperative for both scholars and practitioners to comprehend the concept of corporate sustainability transition (CST), which entails the establishment of shipping operations that effectively balance environmental, social, and economic considerations. Additionally, technologies that are used to facilitate the transition process must be investigated. Several studies have been undertaken to ascertain the attributes pertaining to sustainability transition. Nevertheless, there has been a lack …

Research On Risk Assessment Of Container Operation Process In Ports Considering Functional Areas, Chen-Yu Lin, Ming-Jiu Hwang, Tzu-Heng Yen

Journal of Marine Science and Technology–Taiwan

The risk management of container ports has drawn significant attention recently in part because of recent high-profile accidents in global container ports and in part due to the increasing focus on port safety as a key element in sustainable maritime transportation. This research presented a novel, two-layer container port risk assessment model by partitioning the container port into four areas based on the process of container transportation: loading and unloading, in-port container transportation, storage, and gate areas. Failure mode and effects analysis (FMEA) and quantitative risk analysis modeling were combined for each part of the process to evaluate the risk …

Artificial Intelligence In Prediction Of The Remaining Useful Life Of Wind Turbine Shaft Bearings, Jinsiang Shaw, B.J. Wu

Journal of Marine Science and Technology–Taiwan

Long-term periodic rotation and unstable load changes in wind turbines can cause unexpected damage to high-speed shaft bearings (HSSBs). In this study, after preprocessing of the HSSB vibration signal, four different models for predicting bearing degradation in terms of remaining useful life (RUL) in days were investigated: support vector regression (SVR), convolutional neural networks (CNN), long short-term memory (LSTM), and CNN-LSTM. The experimental results revealed that the CNN achieved the best mean absolute error (MAE), at 0.44 days, based on frequency response plot using the fast Fourier transform (FFT), while that of the CNN-LSTM model predicted using the amplitude profile …

Impact Of Multiple Water Temperature Structures On The Behavioral Pattern Of Chum Salmon (Oncorhynchus Keta) On The Coast Of The Shiretoko Peninsula, Xinyi Li, Hiroshi Yamaguchi, Hokuto Shirakawa, Kenji Minami, Nobuhiko Sato, Yanhui Zhu, Yasuyuki Miyakoshi, Kazushi Miyashita

Journal of Marine Science and Technology–Taiwan

During the migration of chum salmon (Oncorhynchus keta) towards the Shiretoko Peninsula in Hokkaido, Japan, the convergence of coastal currents results in the formation of intricate water temperature structures. However, the impact of this phenomenon on the behavioral tendencies of chum salmon remains largely unexplored. In 2012 and 2013, we conducted a study to document the vertical water temperature profiles and uninterrupted swimming patterns of homing chum salmon in the coastal waters surrounding the Shiretoko Peninsula. The results indicated that chum salmon exhibited a preference for avoiding thermoclines characterized by rapidly decreasing water temperatures. They were predominantly observed swimming either …

Research On The Collision Risk Of Ships Off Keelung Based On Ais Data, Shih-Tzung Chen, Ming-Feng Yang, Sheng-Long Kao, Mengru Tu, Jun-Yuan Kuo, Yen-Ting Chao, Huang-Kai Hsu

Journal of Marine Science and Technology–Taiwan

In previous literature, several computational methods have been proposed to analyze collision risks for vessels navigating at sea, most of which rely on the calculation of DCPA and TCPA between two vessels. However, this study adopts an enhanced version of the Vessel Conflict Ranking Operator (VCRO) to assess vessel collision risks. This approach not only considers the relative distance and relative velocity between two vessels but also takes their relative aspect into account. This methodology was applied to real-world vessels’ dynamic data collected through AIS. From a near-collision perspective, it identifies high-risk areas near Keelung water where commercial vessels and …

Cooling Performance Analysis For Mobile Vehicles By Thermal Resistance Network, Chia-An Yang, Jung-Chang Wang, Pi-Hsia Yen

Journal of Marine Science and Technology–Taiwan

This paper used CFD software to simulate the cooling situation of the engine space of a mobile vehicle. We used thermal resistance network diagram to calculate the heat flux at each position of the power system, and discussed the CFD simulation results. The error between the simulation results and the experiment was 10.07%. The thermal resistance network diagram proposed in this paper can reduce the time for numerical simulation by evaluate the heat flux at each position of the power system.

Microbial Community And Genome Structure In Coastal Seawater From A Commercial Port And Nearby Offshore Island In Northern Taiwan, Chi-Yu Shih, Ching-Hsiang Chin, Shiow-Yi Chen, Chun-Ru Hsu, Lee-Kuo Kan, Wen-Shyong Tzou

Journal of Marine Science and Technology–Taiwan

The pollution stemming from the use of petroleum by boats, the presence of deceased marine life, hazardous chemicals, and wastewater is a major issue in human-made commercial ports. This pollution poses a considerable challenge to the diverse organisms inhabiting the seawater. To comprehend the impact of this pollution on the microbiome, we conducted a study in which we collected surface water samples from a commercial port called Keelung Port, as well as a nearby offshore island known as Keelung Islet. These locations are situated in northern Taiwan, along the Northwestern Pacific Ocean. Through the use of whole-metagenome shotgun sequencing, we …

Performance Analysis: Using The Northern Sea Route As An Alternative To Traditional Routes, Liangkun Xu, Qing Yu

Journal of Marine Science and Technology–Taiwan

The grounding accident of M/V EVER GIVEN in the Suez Canal causes a catastrophic loss on shipping companies. Alternatively, previous studies have presented encouraging findings of the remarkable benefits of time and cost saving in the Northern sea route (NSR) due to extend the ice-free time and shorten the distance. Ships using the NSR could shorten as much as 40% of the sailing distance from China (Shanghai) to Europe (Rotterdam) compared with the traditional route via the Suez Canal. This paper investigates the economic potential of using the NSR as a cost-effective route in comparison with Suez Canal Route (SCR) …

Numerical And Approximate Analytic Solutions Of Second- Order Nonlinear Boundary Value Problems, Chein-Shan Liu, Jian-Hung Shen, Yung-Wei Chen

Journal of Marine Science and Technology–Taiwan

The shooting method consists of guessing unknown initial values, transforming a second-order nonlinear boundary value problem (BVP) to an initial value problem and integrating it to obtain the values at the right end to match the specified boundary condition, which acts as a target equation. In the shooting method, the key issue is accurately solving the target equation to obtain highly precise initial values. Due to the implicit and nonlinear property, we develop a generalized derivative-free Newton method (GDFNM) to solve the target equation, which offers very accurate initial values. Numerical examples are examined to show that the shooting method …

Optimization Of Circular Silencers Internally Hybridized With Multiple Reverse Chambers Using The Ga Method, Min-Chie Chiu, Ying-Chun Chang, Tian-Syung Lan, Ho-Sheng Chen

Journal of Marine Science and Technology–Taiwan

A noise abatement method using an eigen function in conjunction with an optimizer (Genetic Algorithm) under a space-constrain situation is proposed in this study concerning a high order wave propagation effect. An eigen function is used to describe an acoustical field and shorten the acoustical model in a four-pole transfer matrix form. The system’s four-pole matrix estimates the Transmission Loss (TL) for the silencers by multiplying individual four-pole matrices.

Additionally, a case study of an air compressor’s broadband noise elimination is introduced. Three types of circular reverse silencers (silencers A-C) internally hybridized with multiple straight chambers are adopted to efficiently …

Numerical Investigation Of The Uncertainty Of Typhoon Wave Parameters Retrieval Using Hf Radar, Toan Duy Dao, Hwa Chien

Journal of Marine Science and Technology–Taiwan

The aim of this study was to identify the sources of uncertainties of typhoon wave field monitoring using HF radar and to quantitatively assess the bias of the wave parameters, such as significant wave height and mean period, retrieved under various conditions. The strategy was to apply a purely numerical simulation of the Doppler-range spectra and then compare the estimation results to the target. For the quantitative investigation, a numerical test-bed was established. The test-bed was used to simulate the Doppler spectra based on Barrick’s (1972) theory by using the input of the directional wave spectra. The typhoon wave spectra …

A Fused Data Based Real-Time Collision Warning System For Ferries In The Yangtze River, Xiaojia Liu, Ke Zhang, Han Xue, Yingtang Li

Journal of Marine Science and Technology–Taiwan

The risks for ferries in the Yangtze River are relatively high, as they frequently cross the main traffic flows, leading to more intersections with other upwards and downwards ships. Although some studies have developed many models to assess collision risks in the Yangtze River, collision warning studies on ferries are scant. Meanwhile, most of the current collision studies evaluate risk based on AIS data, which are incapable of providing real-time ship information as they are discrete-time series data. In this work, fused data combining radar and AIS data are applied in a real-time ship collision warning model to assess the …

Experimental Study Of The Effect Of A Solid Wing Conveyor On Marine Debris Collection, Erik Sugianto, Jeng-Horng Chen

Journal of Marine Science and Technology–Taiwan

Marine debris is a global problem that has not been resolved. This has encouraged the emergence of marine debris cleaning technologies, one of which is a conveyor ship. However, how effective conveyors are in collecting waste has not been studied. In this paper, experimental research on conveyors as marine debris collectors is investigated. The capability of catamarans with or without solid wing conveyors to collect marine debris is explored. Three kinds of marine debris collection models are used: no-wing conveyor, a 12.5-cm-long wing conveyor, and an 18.75-cm-long wing conveyor. Artificial marine debris (AMD) is spread on the water surface in …

Solving Nonlinear Boundary Value Problems With Nonlinear Integral Boundary Conditions By Local And Nonlocal Boundary Shape Functions Methods, Chein-Shan Liu, Yung-Wei Chen, Jian-Hung Shen

Journal of Marine Science and Technology–Taiwan

The paper considers the second-order nonlinear boundary value problem (NBVP), which is equipped with nonlinear integral boundary conditions (BCs). Two novel iterative algorithms are developed to overcome the difficulty of NBVP with double nonlinearities involved. In the first iterative algorithm, two nonlocal shape functions incorporating the linear integral terms are derived, and a nonlocal boundary shape function (NBSF) is formulated to assist the solution. Let the solution be the NBSF so that the NBVP can be exactly transformed into an initial value problem. The new variable is a free function in the NBSF, and its initial values are given. For …

Key To The Species Of Tortanidae Tortanus Occurring In The China Seas, Chang-Tai Shih, Qing-Chao Chen, Yang-Chi Lan, Shih-Hui Hsiao, Chi-Yu Weng

Journal of Marine Science and Technology–Taiwan

No abstract provided.

Key To The Species Of Tharybidae Neoscolecithrix Occurring In The China Seas, Chang-Tai Shih, Qing-Chao Chen, Yang-Chi Lan, Shih-Hui Hsiao, Chi-Yu Weng

Journal of Marine Science and Technology–Taiwan

No abstract provided.

Key To The Species Of Temoridae Temora Occurring In The China Seas, Chang-Tai Shih, Qing-Chao Chen, Yang-Chi Lan, Shih-Hui Hsiao, Chi-Yu Weng

Journal of Marine Science and Technology–Taiwan

No abstract provided.

Key To The Species Of Subeucalanidae Subeucalanus Occurring In The China Seas, Chang-Tai Shih, Qing-Chao Chen, Yang-Chi Lan, Shih-Hui Hsiao, Chi-Yu Weng

Journal of Marine Science and Technology–Taiwan

No abstract provided.