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Full-Text Articles in Other Oceanography and Atmospheric Sciences and Meteorology

A Novel Identity Authentication Mechanism For Unmanned Maritime Vessels Communication Based On Mitre Att&Ck Framework, Junxian He, Shih-Hao Chang Jan 2024

A Novel Identity Authentication Mechanism For Unmanned Maritime Vessels Communication Based On Mitre Att&Ck Framework, Junxian He, Shih-Hao Chang

Journal of Marine Science and Technology–Taiwan

With the development of the smart shipping industry, unmanned vessel technology is rapidly evolving, accompanied by a demand for robust Internet of Things (IoT) communication security practices. Key communication technologies for the operation of unmanned vessels include external vessel communication. One crucial aspect is the verification of the identities of the parties involved in these communication systems, as this ensures secure and trusted interactions between unmanned vessels and port management authorities. Identity authentication plays a vital role in ensuring the secure communication of unmanned vessels.This paper aims to analyze potential risks related to identity authentication technology in unmanned vessel communication …


Corrigendum To “Applicability Of Reducing Valve Timing Overlap For Diesel Engines Under High Exhaust Back Pressure” Jan 2024

Corrigendum To “Applicability Of Reducing Valve Timing Overlap For Diesel Engines Under High Exhaust Back Pressure”

Journal of Marine Science and Technology–Taiwan

No abstract provided.


Distribution And Population Structure Of Corallivorous Drupella Snails In The Coral Reefs Of Kenting In Taiwan, Chih-Jui Tan, Dun-Ru Kang, Li-Lian Liu Jan 2024

Distribution And Population Structure Of Corallivorous Drupella Snails In The Coral Reefs Of Kenting In Taiwan, Chih-Jui Tan, Dun-Ru Kang, Li-Lian Liu

Journal of Marine Science and Technology–Taiwan

The corallivorous Drupella snails are common predators of living hard corals in the Indo-Pacific Ocean, and they can significantly threaten coral reef ecosystems when outbreaks occur. In Taiwan, a Drupella outbreak, which resulted in the dramatic decline of Acropora and Montipora corals, was reported in Penghu in 2002 – 2009. However, the Drupella species involved was not identified, and no further research has been conducted. To obtain current knowledge on the predation pressure of corallivorous snails on hard corals, we investigated benthic communities and the distribution and population structure of Drupella snails in the coral reefs of Kenting, Taiwan. The …


Evaluating The Connectivity Reliability Of The Seaborne Transportation Network Using Uncertainty Theory, Tianshou Liu, Haiyang Bian, Lin Feng, Chenyang Fan, Chaojun Ding, Grifoll Manel, Hongxiang Feng Jan 2024

Evaluating The Connectivity Reliability Of The Seaborne Transportation Network Using Uncertainty Theory, Tianshou Liu, Haiyang Bian, Lin Feng, Chenyang Fan, Chaojun Ding, Grifoll Manel, Hongxiang Feng

Journal of Marine Science and Technology–Taiwan

The shipping network serves as the backbone of international trade. However, due to unstable geopolitical conditions, unexpected events have occurred frequently in recent years that have impacted the global shipping supply chain, and this has placed enormous pressure and had adverse effects on seaborne transportation. To measure the reliability of the global shipping network under unexpected events, we abstract the global shipping network into a small world network using uncertainty theory. A method is proposed for selecting (i) the optimal reliable path and (ii) the optimal reliable path with a maximum measurement under different confidence intervals. Our approach is then …


Mechanical Property Analysis And Three-Dimensional Reverse Reconstruction Based On Corrosion Pit Characteristics Of Strong Corrosion Steel Plate, Qiujun Ning, Xiaosong Lu, Jiawei Lu Jan 2024

Mechanical Property Analysis And Three-Dimensional Reverse Reconstruction Based On Corrosion Pit Characteristics Of Strong Corrosion Steel Plate, Qiujun Ning, Xiaosong Lu, Jiawei Lu

Journal of Marine Science and Technology–Taiwan

To investigate the strong corrosion effect of 36% industrial hydrochloric acid on Q370 steel for bridges at room temperature. The surface morphology variations of the Q370 steel for bridges with corrosion time were measured and analyzed using a three-dimensional non-contact scanning profilometer. Subsequently, the standard monotonic tensile test was carried out to obtain the load-displacement curve and analyze the mechanical properties of the heavily corroded steel. Moreover, the constitutive model parameters of the heavily corroded steel were optimized. Furthermore, the heavily corroded steel model base on the actual corroded surface morphology was established, employing three-dimensional reverse reconstruction technology and finite …


Sea Ice Identification And Risk Assessment For Navigation In Ice Regions Based On Shipboard Camera Images, Tsung-Hsuan Hsieh, Xuan Lu, Shengzheng Wang, Wei Liu, Jianan Luo Jan 2024

Sea Ice Identification And Risk Assessment For Navigation In Ice Regions Based On Shipboard Camera Images, Tsung-Hsuan Hsieh, Xuan Lu, Shengzheng Wang, Wei Liu, Jianan Luo

Journal of Marine Science and Technology–Taiwan

In order to guarantee the safe navigation of vessels in icy regions and effectively capture sea ice risk information surrounding ships, this study introduces a sea ice identification and risk assessment process utilizing shipboard camera images. Firstly, based on the distribution characteristics of sea area, a hierarchical region segmentation algorithm is proposed to precisely remove interference factors and extract the region of interest. Then, a multivariate K-means clustering algorithm is proposed to classify sea ice classes based on various characteristics, including spatial similarity, sea ice area, sea ice thickness, gray scale, and other multivariate information. Finally, a method for small …


Optimization On Container Drayage Scheduling In Stochastic Time-Dependent Network, Qi Xu, Jie Huang, Xingyue Chen, Rui Cheng, Xiangyu Yin, Zhongzhen Yang Jan 2024

Optimization On Container Drayage Scheduling In Stochastic Time-Dependent Network, Qi Xu, Jie Huang, Xingyue Chen, Rui Cheng, Xiangyu Yin, Zhongzhen Yang

Journal of Marine Science and Technology–Taiwan

To ensure a reliable operation of container drayage transport system, this paper investigates the drayage scheduling problem in a stochastic time-dependent network. Based on the theory of the robust optimization, a mathematical model considering the attributes of “synchronized operation of multi machines” is built with the aim of minimization of the schedule delay in the whole system. A Simulated Annealing algorithm with Embedded Heuristics (SAEH) is designed for model solution. Comparisons between the results from the robust optimization and traditional expected value approach, and the results from the SAEH and CPLEX are conducted. Based on that, the effectiveness of our …


Offshore Vertical Axis Wind-Photovoltaic Power Plants: Development And Case Study, Victor V. Cheboxarov, Pavel N. Kuznetsov, Shun-Han Yang, Shiu-Wu Chau Jan 2024

Offshore Vertical Axis Wind-Photovoltaic Power Plants: Development And Case Study, Victor V. Cheboxarov, Pavel N. Kuznetsov, Shun-Han Yang, Shiu-Wu Chau

Journal of Marine Science and Technology–Taiwan

This paper examines the potential for the development and implementation of hybrid wind-solar power plants utilizing large-scale offshore vertical-axis wind turbines. The proposed solution aims to increase energy production and reliability through the integration of photovoltaic modules directly into the wind turbine structure. Schematics of photovoltaic modules on the upper annular surface of the respective wind turbine are considered. The operation of the hybrid power plant is described. Equations to estimate the power characteristics of the plant are given. The case study analyzes the potential energy production of a hybrid marine power plant with a diameter of 200 m at …


Harvest By Autoflocculation, Biomass, And Carotenoid Production In Sequential Batch Culture Of Haematococcus Pluvialis Under High Ionic Strength And Macroelements Content, J. Galán-González, I. Quintero-Zapata, M Elías-Santos, L.J. Galán-Wong, U.J. López-Chuken, C Guajardo-Barbosa, J.C Beltrán-Rocha Jan 2024

Harvest By Autoflocculation, Biomass, And Carotenoid Production In Sequential Batch Culture Of Haematococcus Pluvialis Under High Ionic Strength And Macroelements Content, J. Galán-González, I. Quintero-Zapata, M Elías-Santos, L.J. Galán-Wong, U.J. López-Chuken, C Guajardo-Barbosa, J.C Beltrán-Rocha

Journal of Marine Science and Technology–Taiwan

Haematococcus pluvialis is a microalga with significant potential due to its capacity to produce carotenoids with antioxidant and nutraceutical benefits. However, the cost of harvesting this microalga, constituting over 30% of total expenses in large-scale production, is a major concern. Efficient flocculation, aiding in cell separation from the culture medium, is crucial to address this issue. The study contrasted Bold’s Basal Medium (BBM) with Lopez-Chuken & Young nutrient solution (LC-Y). The heightened salt content in LC-Y plays a crucial role in fostering saline stress, which is essential for evaluating H. pluvialis flocculation, biomass yield, and carotenoid production. To assess stability …


Research Progress On Ship Trajectory Prediction In Marine Transportation, Xiangen Bai, Kai Ye, Xiaofeng Xu Jan 2024

Research Progress On Ship Trajectory Prediction In Marine Transportation, Xiangen Bai, Kai Ye, Xiaofeng Xu

Journal of Marine Science and Technology–Taiwan

The prediction of ship navigation trajectories is crucial for ensuring maritime navigation safety and forecasting risk. In recent years, extensive research has been conducted on the prediction of ship navigation trajectories at home and abroad, and some results have been achieved. At present, most research on ship navigation trajectory prediction relies heavily on automatic identification system (AIS) data and the historical trajectories of ships. This study first reviews the research background and current situation of ship navigation trajectory prediction. Second, it provides an overview of ship navigation trajectory prediction, with an emphasis on sorting out and elaborating on artificial intelligence …


Numerical Investigations On Particle Collection And Discharge Of Rounded Rectangle Aquaculture Tank In Dual-Diagonal-Inlet Layout, Xiaozhong Ren, Shupeng Du, Hangfei Liu, Xianying Shi, Meng Li, Xian Wang, Suping Liu Jan 2024

Numerical Investigations On Particle Collection And Discharge Of Rounded Rectangle Aquaculture Tank In Dual-Diagonal-Inlet Layout, Xiaozhong Ren, Shupeng Du, Hangfei Liu, Xianying Shi, Meng Li, Xian Wang, Suping Liu

Journal of Marine Science and Technology–Taiwan

To improve the space utilization rate of aquaculture tanks in aquaculture facilities and investigate the effect of the length-width ratio parameter (abbr. L/W, with L being the length of the tank and W being its width) on the particle collection and discharge characteristics of the rounded rectangle aquaculture tank with diagonal double inlet pipes. The study simulates the particle discharge procedure of the tank using a solidliquid two-phase numerical model (discrete phase model and RNG k-ε turbulence model adopted). The validity of the numerical model was confirmed through physical experiments. The simulation results for two jet condition indicate that when …


A Preliminary Study On Floating Flexible Otec Cold Water Pipe, Nai Kuang Liang, Hai Kuan Peng Dec 2023

A Preliminary Study On Floating Flexible Otec Cold Water Pipe, Nai Kuang Liang, Hai Kuan Peng

Journal of Marine Science and Technology–Taiwan

Ocean Thermal Energy Conversion (OTEC) requires a large amount of cold seawater. The traditional rigid pipe, semi-rigidly fixed onto the ship bottom is not easy to install and disassemble, so the Floating Flexible Cold Water Pipe (FFCWP) flexibly connected to the ship is proposed. A small FFCWP was designed, fabricated, and successfully installed and recovered in the sea. The flexible pipe adopts commercially available fire ventilation snake pipe. The pipe wall material strength must be improved in the future. Assuming that the drag coefficient Cd value is 1.5, a numerical calculation is employed to simulate the FFCWP attitude from the …


Machine Learning With Multi-Source Data To Predict And Explain Marine Pilot Occupational Accidents, Gokhan Camliyurt, Youngsoo Park, Daewon Kim, Won Sik Kang, Sangwon Park Dec 2023

Machine Learning With Multi-Source Data To Predict And Explain Marine Pilot Occupational Accidents, Gokhan Camliyurt, Youngsoo Park, Daewon Kim, Won Sik Kang, Sangwon Park

Journal of Marine Science and Technology–Taiwan

Marine pilot occupational accidents during transfer to/from ships are the primary concern of the International Marine Pilots’ Association (IMPA) and industry professionals. There are multiple transfer methods for marine pilots, with the most common being the pilot boat. To reach the mother ship bridge, the following stages must be safely completed: car transfer, walking on the pier, pier to pilot boat, pilot transfer by boat, cutter to pilot ladder, mother ship freeboard climbing, and ship deck to the bridge. Each stage has its own risk. Previous accident records and expert opinions are commonly used to conduct a risk analysis and …


Evaluation Of Operational Performance Of Wusongkou Cruise Port Through Network Data Envelopment Analysis, Qian-Feng Wang, Guo-Ya Gan, Xin-Liang Ye, Hsuan-Shih Lee Dec 2023

Evaluation Of Operational Performance Of Wusongkou Cruise Port Through Network Data Envelopment Analysis, Qian-Feng Wang, Guo-Ya Gan, Xin-Liang Ye, Hsuan-Shih Lee

Journal of Marine Science and Technology–Taiwan

As major hubs for cruise berthing and passenger transfers, cruise ports in China were developing rapidly in the years before the COVID-19 pandemic because of an ever-growing regional market. Wusongkou Cruise Port is the most important port for cruise ships in China, and this study evaluated the operational performance of this port during 2011–2020. To this end, two-stage network data envelopment analysis was conducted to evaluate the port’s operation performance; subsequently, the change trajectory of the port’s operational efficiency during 2011–2020 was determined, and the potential reasons for the identified changes are discussed. Finally, suggestions for improving the operational performance …


Smart Sounding Table Using Adaptive Neuro-Fuzzy Inference System, Osman Ünal, Nuri Akkaş Oct 2023

Smart Sounding Table Using Adaptive Neuro-Fuzzy Inference System, Osman Ünal, Nuri Akkaş

Journal of Marine Science and Technology–Taiwan

Marine engineers measure the liquid level (sounding depth) to calculate the volumetric content of a ship's tank. The sounding depth is determined using an ullage pipe located at specific points on the tanks. To estimate the accurate volume of liquid, considering the ship's trim and heel conditions, engineers use a tank table (sounding table) consisting of hundreds of pages. However, this method is time-consuming and lacks intermediate values for sounding depth, trim, and heel. Ship designers recommend to use linear interpolation for intermediate values, yet this process is also time-consuming. This paper proposes the implementation of an Adaptive Neuro-Fuzzy Inference …


Case Study Of Coastal Erosion And Measures At Kezailiao Coast, Taiwan, Tai-Wen Hsu, Yi-Tse Tu, Jen-Yi Chang Oct 2023

Case Study Of Coastal Erosion And Measures At Kezailiao Coast, Taiwan, Tai-Wen Hsu, Yi-Tse Tu, Jen-Yi Chang

Journal of Marine Science and Technology–Taiwan

This paper examines major factors of coastal erosion and measures against beach erosion at Kezailiao Coast, Taiwan. Typical examples of coastal erosion due to natural or man-made factors are reviewed. Case studies of countermeasure for beach erosion are addressed. We further analyze and discuss historical shoreline and coastal cliff recession as a result of the attack of storm surges and waves. The coastline mainly made up of cliffs (2-3m high), made of soft, easily eroded boulder sand and clay. In total, 3km of land have been lost since 1951, including villages and farm buildings. The most important impacts of beach …


Wearable Sensor-Based Walkability Assessment At Ferry Terminal Using Machine Learning: A Case Study Of Mokpo, Korea, Jungyeon Choi, Hwayoung Kim Oct 2023

Wearable Sensor-Based Walkability Assessment At Ferry Terminal Using Machine Learning: A Case Study Of Mokpo, Korea, Jungyeon Choi, Hwayoung Kim

Journal of Marine Science and Technology–Taiwan

Walkability assessments are becoming more popular, as walking offers numerous health, environmental, and economic benefits to communities. However, previous studies on ferry terminal walkability assessment have been inadequate. This study aimed to develop a wearable sensor system to automatically assess walkability at ferry terminals without conducting surveys. We applied seven machine learning (ML) classifiers to detect different walking environments, including flat ground (FG), downhill slope (DS), uphill slope (US), and uneven surface (UE). The ML models were evaluated across different combinations of classes: 2-class (FG vs. UE), 3-class (U) (FG vs. US vs. UE), 3-class (D) (FG vs. DS vs. …


Application Of Blockchain Technology In Aquaculture Management, Yu-Jen Pan, Hsin-Pei Shieh Oct 2023

Application Of Blockchain Technology In Aquaculture Management, Yu-Jen Pan, Hsin-Pei Shieh

Journal of Marine Science and Technology–Taiwan

In recent years, food safety has become a growing concern in Taiwanese society. To ensure efficient management of the supply chain within the L Aquatic Products company, it is imperative to employ reliable technical support in establishing an effective traceability management system. The traceability of products can provide managers with valuable insight into the intricacies of the supply chain. By establishing a dependable food traceability system, brand trust can be strengthened, and consumers can inquire about the movement of aquatic products within the supply chain. Blockchain technology offers features such as traceability, accountability, transparency, reliability, trust, privacy, and security, making …


Production Of Ground Granulated Blast-Furnace Slag Cement: Energy And Carbon Reduction Efficiency Of Cement-Grinding System, Kuan-Hung Lin, Chung-Chia Yang Oct 2023

Production Of Ground Granulated Blast-Furnace Slag Cement: Energy And Carbon Reduction Efficiency Of Cement-Grinding System, Kuan-Hung Lin, Chung-Chia Yang

Journal of Marine Science and Technology–Taiwan

This study used clinker, ground granulated blast-furnace slag (GGBS), and gypsum in a cement-grinding system to produce GGBS cement (GCE). Gypsum was used as the alkaline activator to modify the surface area of GCE and increase its compressive strength. The results revealed that the use of the gypsum activator and the modification of the surface area of GCE effectively increased the formerly inadequate compressive strength of GCE (GGBS > 60%) in the early stage. In addition, energy consumption data were obtained during the production of GCE and Portland cement (PCE) by the cement-grinding system. The calculations concerning the production proportions indicated …


Three-Dimensional Higher-Order Compressive Sensing For Raypath Separation In An Acoustic Waveguide, Fengyan Zhong Jun 2023

Three-Dimensional Higher-Order Compressive Sensing For Raypath Separation In An Acoustic Waveguide, Fengyan Zhong

Journal of Marine Science and Technology–Taiwan

In an acoustic waveguide, the separation of multiple raypaths, especially close raypaths, is a challenging task in the presence of colored noise due to interference in the acoustic eld. In this paper, a three-dimensional higher-order compressive sensing method for raypath separation is proposed. The method is applied on an array-to-array experimental conguration where both emitter and reception arrays are used. With the array-to-array conguration, the raypaths are characterized by three parameters including arrival direction, departure direction, and arrival time. Furthermore, the performance of the proposed algorithm is illustrated by simulations and experiments. The numerical results based on simulation illustrate that …


Projection Of Sea Surface Temperature Based On Empirical Mode Decomposition And Its Application In Typhoon Number Forecast, Wen-Cheng Huang, Jung-Chen Lee Jun 2023

Projection Of Sea Surface Temperature Based On Empirical Mode Decomposition And Its Application In Typhoon Number Forecast, Wen-Cheng Huang, Jung-Chen Lee

Journal of Marine Science and Technology–Taiwan

The primary objective of this paper is to demonstrate the applicability of empirical mode decomposition (EMD) in projecting non-stationary daily sea surface temperature (SST) series, and the other is to apply the projected series of SST to estimate the number of typhoons. The study focuses on an area ranging from 5°N~25°N and 110°E~170°E, collecting daily sea temperature data and typhoons records within this region. The findings conclusively indicate that the EMD-based data generation method proposed in this paper can effectively addresses the limitations of previous hydrological models in generating non-stationary series, signifying a significant advancement in hydrological time series modeling …


Effects Of Various Dietary Carbohydrate Sources On The Growth Performance And Body Composition Of The Dog Conch, Laevistrombus Canarium, Jen-Hong Chu Mar 2023

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, Tai Hui-Huang, Chang Chin-Wei Mar 2023

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, Chih-Yen Lin, Chun-Fu Chang, Chung-Chia Yang Mar 2023

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, Min-Chie Chiu, Ho-Chih Cheng Mar 2023

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, Liu Lin, Li Wanwu, Li Hang, Sun Yi Mar 2023

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, Hsing-Yu Wang, Hui-Ming Fang, Yun-Chih Chiang Mar 2023

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 …


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 Jan 2023

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 …


Genetic Algorithm For Solving A Just-In-Time Inventory Model With Imperfect Rework Implemented In A Serial Multi-Echelon System, Hsien-Chung Tsao, Cheng-Chi Chung, Hsuan-Shih Lee, Chih-Ping Lin, Yan-Yun Tu, Ssu-Chi Lin Jan 2023

Genetic Algorithm For Solving A Just-In-Time Inventory Model With Imperfect Rework Implemented In A Serial Multi-Echelon System, Hsien-Chung Tsao, Cheng-Chi Chung, Hsuan-Shih Lee, Chih-Ping Lin, Yan-Yun Tu, Ssu-Chi Lin

Journal of Marine Science and Technology–Taiwan

As global industrial competition intensifies, enterprises can achieve substantial competitive advantages in the supply chain management environment by promptly meeting customer demands and efficiently reducing both supply and demand costs. This paper proposes an inventory model for supply chain optimization that considers uncertain delivery lead times and defective products. Solving the model requires solving a nonlinear mixed-integer problem, which traditionally requires considerable time. Solutions to nondeterministic polynomial-time hard problems with high complexity and difficulty are often obtained using heuristic algorithms. Among these algorithms, genetic algorithms have high efficiency and quality. Therefore, we employed a genetic algorithm to solve the proposed …


An Mrf Model-Based Study On The Effect Of Fishes Upon The Characteristics Of Flow Field Of An Aquaculture Tank, Xian-Ying Shi, Zheng-Zheng Huang, Meng Li, Yinxin Zhou, Xiao-Zhong Ren, Hang-Fei Liu, Shu-Peng Du Jan 2023

An Mrf Model-Based Study On The Effect Of Fishes Upon The Characteristics Of Flow Field Of An Aquaculture Tank, Xian-Ying Shi, Zheng-Zheng Huang, Meng Li, Yinxin Zhou, Xiao-Zhong Ren, Hang-Fei Liu, Shu-Peng Du

Journal of Marine Science and Technology–Taiwan

The study aims to investigate the effect of fish movement on the flow field in the aquaculture tank of a recirculating water aquaculture system. Herein, based on the Navier-Stokes equations and the RNG k-ε turbulence model, the flow field in the aquaculture tank with fish movement was numerically simulated using the multiple reference frame (MRF) model and compared with the numerical simulation results of the fishless aquaculture tank. The results revealed that the overall mean flow velocity in the tank decreased significantly when the fish swam counter-currently with a fixed trajectory, and the overall mean flow velocity increased slightly when …