United States Department of Agriculture
Purdue University
Virginia Institute of Marine Science
A Case Study Using 2019 Pre-Monsoon Snow And Stream Chemistry In The Khumbu Region, Nepal,
2021
University of Maine
A Case Study Using 2019 Pre-Monsoon Snow And Stream Chemistry In The Khumbu Region, Nepal, Heather M. Clifford, Mariusz Potocki, Inka Koch, Tenzing Sherpa, Mike Handley, Elena Korotkikh, Douglas Introne, Susan Kaspari, Kimberley Miner, Tom Matthews, Baker Perry, Heather Guy, Ananta Gajurel, Praveen Kumar Singh, Sandra Elvin, Aurora C. Elmore, Alex Tait, Paul A. Mayewski
Geological Sciences Faculty Scholarship
This case study provides a framework for future monitoring and evidence for human source pollution in the Khumbu region, Nepal. We analyzed the chemical composition (major ions, major/trace elements, black carbon, and stable water isotopes) of pre-monsoon stream water (4300–5250 m) and snow (5200–6665 m) samples collected from Mt. Everest, Mt. Lobuche, and the Imja Valley during the 2019 pre-monsoon season, in addition to a shallow ice core recovered from the Khumbu Glacier (5300 m). In agreement with previous work, pre-monsoon aerosol deposition is dominated by dust originating from western sources and less frequently by transport from ...
Simulating Cambrian Climate: The Significance Of Atmospheric Co2 Concentration And Continental Position,
2021
University of Northern Colorado
Simulating Cambrian Climate: The Significance Of Atmospheric Co2 Concentration And Continental Position, Grace Cutting
Ursidae: The Undergraduate Research Journal at the University of Northern Colorado
The Cambrian Period began approximately 541 million years ago, and is known for the “Cambrian Explosion”, a time when multicellular life began to rapidly diversify. There is natural historic evidence (isotopes, rock formations, and fossils) that suggests the Cambrian Period experienced a warm climate. However, there is also conflicting evidence that the Cambrian climate may have undergone freezing and thawing cycles, with ice possibly present near the equator. It is critical to understand how ecosystems were able to adapt to past climate changes, especially when analyzing the impacts of modern human activity on climate. Climate model simulations were run to ...
Liner Sailing Speed Optimization Considering Wind And Waves,
2021
College of Transportation, Shandong University of Science and Technology, Qingdao, China
Liner Sailing Speed Optimization Considering Wind And Waves, Zhaokun Wei, Xinlian Xie, Tiantian Bao
Journal of Marine Science and Technology
This paper proposes a new sailing speed optimization problem considering sea conditions such as wind and waves for a container shipping company. Since wind and waves, as exterior factors, can reduce speed, more power is employed as compensation to maintain regular service frequency and avoid delay, resulting in additional bunker consumption and higher cost. Hence, it is necessary to optimize the sailing speed according to the wind and waves. A power model was built to determine the reduced speed caused by the wind and waves for quantifying the speed reduction. On the basis of the proposed model, we developed a ...
A Bilevel Mathematical Approach For The Empty Container Repositioning Proble With A Sharing And Exchanging Strategy In Liner Shipping,
2021
Department of Industrial Engineering and Engineering Management, National Tsing Hua University, Hsinchu City, Taiwan
A Bilevel Mathematical Approach For The Empty Container Repositioning Proble With A Sharing And Exchanging Strategy In Liner Shipping, Dung-Ying Lin, Chieh-Ju Juan
Journal of Marine Science and Technology
In the maritime industry, the management of empty containers is a significant issue whose costs account for a large proportion of the total world fleet running costs. To reduce repositioning activities and increase cost effectiveness, this paper proposes a solution framework considering empty container sharing and exchanging strategies to coordinate the shipping lines in a maritime transportation network. The proposed solution framework considers an empty container matching platform company and a group of shipping lines in a given shipping network. Because of the interactive relationship between the two parties, the proposed problem is formulated as a bilevel programming problem, and ...
Investigating Model Solution Correctness For Parameter Uncertainty In Both Objective Function And Constraints,
2021
Department of Civil Engineering, National Central University, Taoyuan, Taiwan, R.O.C.
Investigating Model Solution Correctness For Parameter Uncertainty In Both Objective Function And Constraints, Shangyao Yan, Sin-Siang Wang, Chun-Yi Wang
Journal of Marine Science and Technology
To resolve engineering management problems encountered in the real world, optimization models are usually formulated with some parameter assumptions. Parameter uncertainty, which may arise due to changes in the environment or human error, may thus be incorporated into the objective function and the constraints. However, to simplify the modeling, the values of these parameters are usually set or projected as deterministic values. It is no wonder that the modelling results based on these inaccurate parameters are neither correct nor reliable. Thus, it is important to examine the correctness of the model results in relation to parameter uncertainty. This study aims ...
Modular Design And Implementation Of An Automatic Power Factor Regulator For Energy Savings On Fishing Vessels,
2021
Department of Systems and Naval Mechatronic Engineering, National Cheng Kung University, Tainan, Taiwan
Modular Design And Implementation Of An Automatic Power Factor Regulator For Energy Savings On Fishing Vessels, Chien-Hsing Lee, Shih-Hsien Hsu, Joe-Air Jiang
Journal of Marine Science and Technology
This study describes the experiences of modular design and implementation of an automatic power factor regulator for improving energy efficiency on Taiwanese longline fishing vessels. The load capacities of such vessels are typically divided into three categories, depending on the gross tonnage or fish carrying capacity: less than 100 kW, from 100 kW to less than 250 kW, and larger than 250 kW. For attaining proper power factor improvement, a compensation unit with a total of 30 kVar, 60 kVar and 90 kVar was sized and assembled with capacitors of 10, 15 and 20 kVar to enable control within 12 ...
Key Risk Factors Influencing Harbor Tugboat Operations For Kaohsiung Port,
2021
Department of Shipping and Transportation Management, National Kaohsiung University of Science and Technology, Kaohsiung, Taiwan, R.O.C.
Key Risk Factors Influencing Harbor Tugboat Operations For Kaohsiung Port, Wen-Jui Tseng, Ji-Feng Ding, Chia-Ming Liu, Liou-Yuan Li
Journal of Marine Science and Technology
The harbor tugboat operation is a very important business and process of Kaohsiung port. To ensure the safety of harbor tugboat operations and to reduce the occurrence of accidents, it is an important issue to conduct a risk assessment of tugboat operations for Kaohsiung port. Hence, the main purpose of this paper is employ the analytic hierarchy process (AHP) method to evaluate key risk factors influencing the harbor tugboat operations for Kaohsiung port. At first, a total of three evalu-ation dimensions with 14 preliminary risk factors are gener-ated from literature and interviews of tugboat captains. We then applied the steps ...
Free Vibration Analysis Of A Free-Free Single-Tapered Beam Carrying Arbitrary Concentrated Elements Using Modified Mode-Superposition Method (Mmsm),
2021
Department of Mechanical and Energy Engineering, National Chia-Yi University, Chia-Yi, Taiwan
Free Vibration Analysis Of A Free-Free Single-Tapered Beam Carrying Arbitrary Concentrated Elements Using Modified Mode-Superposition Method (Mmsm), Chia-Chin Wu
Journal of Marine Science and Technology
The literature contains scant information on the free vibration analyses of the loaded single-tapered beams (STBs) (i.e., STBs carrying concentrated elements (CEs)) Furthermore, even when such studies have been performed, they generally only consider the case of constrained (e.g., free-clamped (F-C)) beams. In other words, the problem of unconstrained (e.g., free-free (F-F)) loaded STBs has not yet to be addressed. Thus, the present study employs the modified mode-superposition method (MMSM) to investigate the free vibration characteristics of the F-F loaded STB carrying arbitrary various CEs. The investigation focuses particularly on the natural frequencies and mode shapes of ...
Optimum Design Of The Underwater Discharge System Based On Surrogate Modeling,
2021
Department of Naval Architecture and Ocean Engineering, Seoul National University, Seoul, Republic of Korea
Optimum Design Of The Underwater Discharge System Based On Surrogate Modeling, Jisang Ha, Myung-Il Roh, Seung-Ho Ham, Sung-Jun Lee
Journal of Marine Science and Technology
Underwater vehicles are equipped with a device for discharging projectiles, called the underwater discharge system. Because these vehicles have limited space, many studies have attempted to reduce the volume of the underwater discharge system while improving its performance. However, owing to the characteristics of the system, the occupied volume and performance conflict with each other. Therefore, minimizing the occupied volume while satisfying the required performance criteria is the most significant requirement in the design stage. To address this, an optimization problem for the underwater discharge system was mathematically formulated and solved using multi-objective genetic algorithms. Additionally, we proposed a method ...
An Analysis Of Key Influencing Factors On Island Tourism Revisit Intentions – Evidence From The Matsu Islands,
2021
Dept. of Shipping and Transportation Management, National Taiwan Ocean University, Taiwan
An Analysis Of Key Influencing Factors On Island Tourism Revisit Intentions – Evidence From The Matsu Islands, Chun-Chieh Wang, Hsiao-Chuan Liu, Hsuan-Shih Lee, Cheng-Chi Chung
Journal of Marine Science and Technology
Sightseeing and tourism not only brings economic benefits to the local community but also drive the development of related industries. In 1992, when the Matsu’s battlefield mission was dissolved, tourism became one of the key development strategies to boom the region. Although the number of visitors to Matsu Islands has risen significantly in recent years, how to increase the island’s willingness to revisit the island has been an important issue. Since local tourism has its own characteristics, island tourism marketing strategies should be different. Many previous studies have quantified the relationship between tourism area satisfaction and willingness to ...
3d Numerical Simulation Of Kuroshio-Induced Wake Near Green Island, Taiwan,
2021
epartment of Marine Environmental Engineering, National Kaohsiung University of Science and Technology, Kaohsiung City, Taiwan
3d Numerical Simulation Of Kuroshio-Induced Wake Near Green Island, Taiwan, Tien-Hung Hou, Jen-Yi Chang, Chia-Cheng Tsai, Tai-Wen Hsu
Journal of Marine Science and Technology
In this research, Kuroshio-induced vortex shedding in the lee of Green Island was numerically studied using the three-dimensional Princeton Ocean Model. The temporal and spatial characteristics of the vortex street were analyzed at different tidal levels, wind fields and water depths. The nu-merical results were validated by comparing with in-situ measurements from the Green Island tidal station, shipboard acoustic doppler current profiler (ADCP), conductivi-ty-temperature-depth (CTD) profiler, and moderate resolution imaging spectroradiometer (MODIS) satellite image datasets. Also, the three-dimensional results of velocity, temperature, and salinity fields were compared well with observational data. Furthermore, the influence depths of the wind effect and ...
Intelligent Fuzzy Control With State-Derivative Feedback For Takagi-Sugeno Fuzzy Stochastic Singular Systems,
2021
Department of Marine Engineering, National Taiwan Ocean University, Keelung, Taiwan, R. O. C.
Intelligent Fuzzy Control With State-Derivative Feedback For Takagi-Sugeno Fuzzy Stochastic Singular Systems, Wen-Jer Chang, Kuang-Yow Lian, Cheung-Chieh Ku, Che-Lun Su
Journal of Marine Science and Technology
This document deals with the problem of passive fuzzy controller design with the state-derivative feedback approach for the nonlinear stochastic singular systems. Recently, the singular systems have a greater focus on literature because they can keep more physical system characteristics than conventional systems. At first, the Takagi-Sugeno fuzzy stochastic singular models are used to represent the nonlinear stochastic singular systems. Then, the state-derivative feedback approach and parallel distributed compensation method are employed to design the passive fuzzy controllers. In the design process, the Lyapunov stability conditions are developed subject to multiple performance constraints, including the passivity constraint and decay rate ...
Sea Ice Warning Visualization And Path Planning For Ice Navigation Based On Radar Image Recognition,
2021
Merchant Marine College, Shanghai Maritime University, Shanghai, China
Sea Ice Warning Visualization And Path Planning For Ice Navigation Based On Radar Image Recognition, Tsung-Hsuan Hsieh, Shengzheng Wang, Huijia Gong, Wei Liu, Ning Xu
Journal of Marine Science and Technology
Ice navigation is currently one of the important issues in path planning studies. Most studies are using sea ice models or ice charts for large-scale path planning, but the weather and ice conditions in the polar waters usually change quickly and are not easy to predict. Under these conditions, small-scale path planning that can be adjusted in time for sea ice collision avoidance is needed. This study uses marine radar imaging to reconstruct the ice navigation scene, and establishes a visual-ization function of sea ice warning on the radar image. We combine the bidirectional rapidly-exploring random tree (B-RRT) algorithm and ...
Enhancing Marine Administrative Management Based On Human Factor Through Safety Criteria,
2021
Department of Business Administration, National Taipei University of Business
Enhancing Marine Administrative Management Based On Human Factor Through Safety Criteria, Wen-Cheng Lin, Hsin-Hung Cheng
Journal of Marine Science and Technology
This study aims to improve maritime safety by enhancing administrative management based on human factors. This study used Fuzzy analytic hierarchy process to analyze the risks and threats regarding safety maritime criteria. Establishing administrative reform is given the highest priority. First, the current model for crew training system is explored. Second, the marine surveyor is examined to determine if it is professional enough for inspection work. Third, the investigation system used by maritime safety investigators should be inspected. The suggestions mentioned expect to establish a maritime administrative reform that could pave the way for the application of maritime safety around ...
Experimental Study On Treatment Of Ballast Water By Inert Flue Gas Deoxidation,
2021
School of Energy and Power, Jiangsu University of Science and Technology, Zhenjiang, China
Experimental Study On Treatment Of Ballast Water By Inert Flue Gas Deoxidation, Guozhi Bao, Peng Yang, Rui Da, Junxia Li, Guanghui Zhao, Ning Chen
Journal of Marine Science and Technology
In this paper, the antimicrobial effect of inert flue gas on indicator microorganisms in ballast water was investigated based on a 265h test. The inert flue gas consists of nitrogen (N2) and carbon dioxide (CO2) the microorganisms include Chlorella and Escherichia coli. Within the scope of the test, the killing effect of the microbes treated by combining N2 and CO2 was higher than that of using only either N2 or CO2. When the dissolved oxygen concentration in the ballast water was 0.5 mg/L and the pH value was 6, the killing effect was the highest. At this time ...
Auroral Heating Of Plasma Patches Due To High-Latitude Reconnection,
2021
Boston University
Auroral Heating Of Plasma Patches Due To High-Latitude Reconnection, Joaquin Diaz Pena, Matthew Zettergren, Joshua Semeter, Yukitoshi Nishimura, Roger Varney, Ashton Reimer, Marc Hairston, Michael Hirsch, Olga Verkhoglyadova, Keisuke Hosokawa, Kazuo Shiokawa
Publications
This study exploits the volumetric sampling capabilities of the Resolute Bay Incoherent Scatter Radar (RISR-N) in collaboration with all-sky imagery and in-situ measurements (DMSP) to examine the interplay between cold plasma transport and auroral precipitation during a high-latitude lobe reconnection event on the dawn side. The IMF had an impulsive negative excursion in B$_z$ embedded within a prolonged period of B$_z>0$ and B$_y
Do Secondary Cyclones Increase The Category Scale Of Atmospheric Rivers?,
2021
Portland State University
Do Secondary Cyclones Increase The Category Scale Of Atmospheric Rivers?, Edgar Sanchez Fausto
University Honors Theses
Atmospheric rivers (ARs) play a crucial role in delivering precipitation worldwide. This makes them an important phenomenon for water resource specialists to study. One such interest is to understand what mechanisms make ARs produce significant rainfall and associated hazards such as flooding. One possible mechanism is that AR duration or intensity may increase when it interacts with a secondary cyclone, either of which can increase the AR category scale. The purpose of this study is to determine whether AR and secondary cyclone interactions increase the category scale ARs. Out of 52 AR events analyzed, 32 events contained at least one ...
Tisher Hopes Climate Timeline Provides Perspective, Serves As A Springboard For Action,
2021
Division of Marketing and Communications
Tisher Hopes Climate Timeline Provides Perspective, Serves As A Springboard For Action, Beth Staples
General University of Maine Publications
For more than a decade, Sharon Tisher, a lecturer in the School of Economics and Honors College, has been researching and writing, "A Climate Chronology" which serves as a record of events in climate science, U.S. policy, and international policy that spans from 1824 to early 2021.
Clayoquot Sound Harmful Algal Blooms Investigation Of Warn Bay To Tranquil Inlet – 2019,
2021
University of Washington Tacoma
Clayoquot Sound Harmful Algal Blooms Investigation Of Warn Bay To Tranquil Inlet – 2019, Katja Whelan
Environmental Science Undergraduate Theses
A large and successful shellfish and fish industry resides in the northeastern Pacific, so when a heat anomaly now known as the “Blob” was discovered in the area there was concern about its impacts. Since many harmful algal blooms (HABs) thrive in higher temperatures, it was important to determine if the “Blob” caused more favorable environmental conditions to support increased amounts of algae in the water. Measurements were taken in 2019 for essential nutrients such as nitrates, phosphates, and silicates, as well as water properties including temperature, salinity, density, dissolved oxygen, transmissivity, and fluorescence. These were then compared to data ...
The Development And Evaluation Of The Atlantic Tropical Cyclone Intensification Regression Model (Atcirm),
2021
Embry-Riddle Aeronautical University
The Development And Evaluation Of The Atlantic Tropical Cyclone Intensification Regression Model (Atcirm), Bruno Platero Huarcaya, Lexi Cruz
Beyond: Undergraduate Research Journal
Operational track forecasts of Tropical Cyclones (TCs) have been improved substantially in recent years and nowadays are sufficiently accurate. However, intensity forecasts have not shown similar improvements, especially for rapidly intensifying storms. The improvement of intensity forecast accuracy can help authorities in risk management and decision making to prevent loss of life and property. The purpose of our project is to develop a statistical linear regression model that provides better predictions for TC intensification over the ocean. Here, different predictor variables are studied, and 2011-2017 Atlantic basin storms are investigated. The final set of predictor variables selected for the model ...
