A Legal Study on Adaptation of the ISM Code to Maritime Autonomous Surface Ships (MASS)

김건 Graduate School of Korea Maritime & Ocean Universi 2021 국내석사

Assessment of container handling system for an under developed container port

Abakah, Peter Kwodwo Graduate School of Korea Maritime & Ocean Universi 2015 국내석사

Effect of Lycopus lucidus Turcz. leaves on matrix metalloproteinase activity and antioxidant

CHEN JINGWEN Graduate school of Korea Maritime & Ocean Universi 2021 국내석사

Lycopus lucidus Turcz. from Lamiaceae family, is a traditional eastern Asian medicinal plant, which is abundant in natural bioactive flavonoids, coumarins, terpenoids and tannins with potential antioxidant activity. In the present study, L. Turcz. leaves were extracted with acetone/methylene chloride and methanol solution, then sequentially partitioned with solvents (n-Hexane, 85% aqueous methanol, and water) in different polarities. Thus, two crude extracts (A+M and MeOH), as well as resulting four fractions (n-Hex, 85% aq. MeOH, n-BuOH and Water) was prepared to investigate the biological activities of L. Turcz. leaves. The effect of six samples on H2O2-induced injury in SH-SY5Y human neuroblastoma cells were evaluated by MTT assay at different doses (0.025 mg/L-0.25 mg/L). To study antioxidant effects of the crude extracts and fractions, reactive oxygen species (ROS) on SH-SY5Y human neuroblastoma cells and changes on intracellular glutathione (GSH) production were determined. In addition, nitric oxide (NO) as a mediator involved in the inflammation reaction, the inhibitory effects of NO production from samples were measured by using the in vitro lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophage cell line. Western blotting experiment was performed to compare the expression level of matrix metalloproteinases-2 and -9 (MMP-2 and MMP-9) in the phorbol 12-myristate 13-acetate (PMA)-induced HT-1080 cells. Finally, radical mediated DNA damage in HT-1080 cells were performed to investigate the protection ability from L. lucidus Turcz. leaves on DNA oxidative damage. In MTT assay, the pretreatment of MeOH extracts and four fractions from L. lucidus Turcz. leaves significantly increased the viability of H2O2 induced SH-SY5Y cells (p<0.05). But there was not any positive effect on SH-SY5Y cell viability after the treatment of A+M sample, which may be explained by the high cytotoxic effect from A+M sample. In western blotting experiment, these extracts and fractions led to a reduction of the secretion levels of MMP-2 and MMP-9 in HT-1080 cells. Due to the cell cytotoxicity of A+M extract, MMP-2 cannot be detected in this group, and only MMP-9 bands were found in control and Water fractions groups. In DNA oxidation analysis, the maximum inhibition of the genomic DNA damage caused by excessive oxidative stress was 80.89%, which is due to the present of A+M extracts. In antioxidant activity, intracellular ROS generation was significantly attenuated in two cells after treatment of crude extracts and fractions (p<0.05), 85% aq. MeOH and n-BuOH fractions showed a better scavenging ability than others. As for the effect of GSH production, A+M extract showed a more powerful ability in enhancing the GSH production by 15.81% than MeOH extract (13.53%) at the concentration of 1 mg/mL; meanwhile, among the fractions at the concentration of 0.5 mg/mL, 85% aq. MeOH fraction increased the GSH level most by 15.30% and followed by the n-BuOH fraction (11.80%). In regard to the effect of production of NO in RAW 264.7 cells, groups of treatment with samples all showed a significant decrease of NO level in comparison with control group (p<0.05). Both extracts efficiently decreased the NO production of cells at the inhibition of more than 80%. However, among the fractions, Water and n-Hex fractions showed better inhibitory effects in NO production than those of 85% aq. MeOH and n-BuOH fractions. Results obtained collectively indicate that the good biological activities from L. lucidus Turcz. leaves, which can be exploited for plant based anticancer and antioxidant agents in the pharmaceutical, cosmetic, nutraceutical and food industries.

Exploring Random Forest and Multilayer Perceptron for Container Throughput Forecasting: The Case of the Port of Douala, Cameroon

PENN COLLINS AWAH Graduate School of Korea Maritime & Ocean Universi 2021 국내석사

An accurate container throughput forecast is vital for any port. Since overall improvements in port performance and competitiveness can be derailed by port bottlenecks, ports need to find leverage to identify and prioritize measures to improve weak key performance indicators (KPI) to attain growth opportunities. Prior studies had modeled container throughput from socioeconomic and growth projection factors. This study aims to provide a practical method for forecasting the optimal container throughput a port can physically handle/attract given a certain level of terminal operation efficiency through random forest (RF) and multilayer perceptron (MLP) models. The study variables are derived from the port operations dimension and include ship turnaround time, vessel draft, container dwell time, berth productivity, container storage capacity, and customs declaration time. Evaluations are made based on the R-squared, NRMSE, MAE & MAPE. Model comparison is deduced with seven competing models in container throughput forecasting. The findings indicate that the RF model is a potential candidate for forecasting the engineering optimal throughput of the Douala port. Model interpretation is provided through feature importance and partial dependence plots. The findings from this study will help reduce uncertainty and provide leverage for port management to spot bottlenecks and engage in better port planning and development projects which will strengthen their international competitive advantage.

An approach of hull form variation based on arbitrary curve-on-surface constraint

Luong Quang Phap Graduate School of Korea Maritime & Ocean Universi 2021 국내석사

Because of the direct relation to every design phase of a ship, ship hull form is frequently designed by varying a well-made parent ship to avoid new design risks. In hull form variation, geometric satisfactory and good performance preservation of the parent ship are considered as the competing requirements. In order to perform the variation effectively, an appropriate compromise between these requirements should be accomplished. Instead of altering hull form parameters, we propose a flexible and intuitive approach to interactively vary hull surface with an arbitrary curve constraint and focus on preserving good properties of the original hull surface. The advantages of superposition of curve and surface is utilized to modify the hull shape. An intermediate surface, which satisfies an intermediate curve constraint and has a smooth shape, is conducted and superimposed on to the top of the original surface to yield the desired surface. A shape control mechanism using shape function simplifies control the surface modification with a curve constraint in a linear fashion way. The developed method is applied to modify a characteristic curve and a section line lying on the stern part of a container hull form. The changes of geometric shape and hydrodynamic performance due to the curve-constraint variation are assessed to demonstrate the practicality and efficiency of the proposed method.

Study on Design and Performance Evaluation of a Cross Flow Turbine to be utilized in a Floating OWC wave energy converter

ABEYSINGHA HETTIGE SAMITHA WEERAKOON Graduate School of Korea Maritime & Ocean Universi 2021 국내석사

In the modern era the adverse effects of human activities has imparted a major threat on the earth’s habitable environment. With the cast technological advancements taken place in the past century led new doors open to global warming and environmental pollution. The carbon emission and other greenhouse gases emissions are the major reason for climate change as well as ozone layer depletion. In addition the rising demand for energy hassled many countries due to exponential decay of fossil fuel resource, the consequences made the man kind look for new, renewable and environmental friendly energy sources. Wave energy offers such a solution to the energy need. Wave energy is the most consistent of all intermittent renewable energy sources. The present study focuses on harnessing offshore wave energy resource by utilizing a direct drive cross flow turbine and also design of a novel floating structure as a supporting fixture for the designed CFT (Cross Flow Turbine) to work. The wave energy resource site selected estimating the annual mean wave power density. The 3.0m significant wave height at 9.0s wave period yields the highest energy bins which occur at the highest number of times per year. The CFT was designed to match these wave conditions. CFT design was based on original preliminary design criterion. Turbine has a 2.0 m diameter and 1.36 m internal diameter, runner has 18 blades and rotates at 35 rev/min. The turbine nozzle was designed to enhance the efficiency of the turbine. Four nozzle shapes are designed varying the nozzle entry arc angle by 20 deg. In each step. To analyze the performance of turbine ANSYS CFX 17.6 commercial code used to simulate the turbine. Turbine width wise 1/15th scale strip of 0.5m used in the numerical simulations to reduce the computational effort, cost and time. Steady state simulations carried out for geometric optimization, the nozzle entry arc angle having 150 deg. preforms best of out of other three nozzle angles. The base model in steady state reached a maximum of 54.33% With 33.366 kW of power output at 35 rev/min with a 3.0m of head. The base model was then analyzed under bi-directional flow simulation with time averaging (Transient) calculation method. Under the effect of bi-directional flow with 3.m of head two rotational speeds were analyzed. The peak cyclic efficiency recorded at 35 rev/min of 56.83% and lowest of 11.55% the average cyclic efficiency was 36.52% with a 36.4 kW of average power output. The flow behavior through the runner and nozzle was analyzed under steady state condition (Numerical calculation computes the fully developed solution that does not change with time, such that the mean values are computed) The 2nd study of design and simulation of a floating structure was carried out. The initial weight estimation was 1200 Tons, and dimensions selection. The initial stability calculation carried out. The model was then taken to ANSYS AQUA 17.6 foe hydrostatic stability parameters to obtain. The COG 9.34m, COB 5.018 m, the Metacentric height (GM) recorded as 4.33m. The intact stability and dynamic stability criterion was satisfied. The model was then taken to SIMEMNS Star CCM+ CFD platform for hydrodynamic behavior calculation. The wave generation with 3.0m height with 9.0s period and the simulated water depth 100m. The model uses options in the simulation physics such as VOF (Volume Of Fluid) waves for generation of waves, Elulerian multiphase for air and water, also Dynamic Fluid Body Interaction (DFBI) model for floating structure to couple with environment and floating body kept in station keeping by four body couplings of catenary mooring type with specified cable stiffness. The Structure and the Turbine was complex to simulate in a single domain, in which an orifice plate was designed to match the turbine pressure and mass flow damping effect to match. The floating structure was then fixed with the orifice plate was simulated. The Floating body damping coefficient was also found by carrying out the free decay test by using numerical method to enhance the stability and power extraction capability. The orifice inside the floating body was examined at 9.0s wave period having a significant wave height of 3.0m, and the orifice potential power and efficiency was calculated based on wave energy availability. The simulations were run on two conditions as the floating structure was inserted with and without the viscous damping coefficient to analyze and compare the dynamics stability and the orifice performance. The damped structure placing the orifice plate performed with a higher potential power of 29MW’s with an orifice efficiency of 21%. The undammed system performed with a lower power potential of 18.4MW at an efficiency of 13.26%. And the system was then simulated Floating body was stable in both hydrostatic and hydrodynamics conditions satisfying the requirement to utilize as a floating type OWC (Oscillating Water Column) WEC (Wave Energy Convertor) to house the designed CFT for the specified wave recourse location.

An Exploratory Study on the Antioxidant, NO Inhibitory and Antiproliferative Activities of Crude Extract and Its Solvent Fractions of the Halophyte, Angelica japonica, Growing in Korean Coastal Area

HETTIARACHCHIGE PRIYANGA Graduate School of Korea Maritime & Ocean Universi 2021 국내석사

The Halophyte, Angelica japonica is an edible, perennial plant and traditionally has been used for several medicinal purposes. Crude extract and its solvent fractions of A. japonica were investigated for antioxidizing ability, cancer cell anti-proliferation, and inhibition of NO production. Antioxidant activity screening was performed by measuring scavenging effect of DPPH radical, peroxynitrite (ONOO) and intracellular ROS (reactive oxygen species), genomic DNA damage, and ferric-reducing power. Also these antioxidant results were confirmed by polyphenol and flavonoid contents analysis. NO inhibitory effect was evaluated by measurement of nitric oxide production in macrophage Raw 264.7 cells. Antiproliferative activity screening was run by measuring cell viability of human fibrosacoma (HT-1080), human gastric adenocarcinoma (AGS), human colon tumor (HT-29), human breast cancer (MCF-7) cell lines using MTT assay. Also Western blot MMP-2 and MMP-9, and cell migration assays for HT 1080 cells have done. Plant materials of A. japonica were collected by hand at Jeju Island and air-dried in shade. The dried plant of A. japonica was extracted twice with methyl chloride and twice with methanol in turn and then crude extract obtained after removal of extract solvent was fractionated into n-hexane, 85% aqeous methanol (85% aq.MeOH), n-butanol, and water. Overall, significant antioxidant effects were successfully observed in crude extract and its solvent fractions (n-BuOH and 85% aq.MeOH fractions). For DPPH radical scavenging activity, crude extract and n-BuOH fraction showed a slight scavenging effect, compared to other fractions but didn’t show a significant scavenging effect, compared to BHA, BHT and vitamin C. For peroxynitrite, crude extract, and n-BuOH and 85% aq.MeOH fractions showed high scavenging effects in a concentration-dependent manner. In an experiment to measure effect of scavenging ROS generated in Raw 264-7 cells, crude extract, and 85% aq.MeOH and n-BuOH fractions exhibited high scavenging ability. In case of NO production, crude extract showed an inhibitory effect against nitrite oxide (NO) produced in Raw 264.7 cells stimulated with lipopolysaccharide (LPS) in a dose-dependent way. But all solvent fractions didn’t show the significant inhibitory effect against NO generation. In proliferation inhibition test for cancer cells, all solvent fractions showed concentration-dependently good antiproliferative effects on all human cancer cell lines used (HT -1080, AGS, HT-29 & MCF-7), especially the effect was high in MCF-7 cell line, and the 85% aq. MeOH fraction revealed relatively the high effect. n-BuOH fraction showed good inhibitory effect against HT-1080 cell line. In addition, inhibitory effect of crude extract and its solvent fractions on MMP-9 and MMP-2 was evaluated in human fibrosarcoma cell line (HT-1080). The n-hexane and 85% aq.MeOH fractions remarkably reduced expression levels on MMP-9 and MMP-2. Examining antioxidant and antiproliferative activities mention above, all the activities were observed in a concentration-dependent manner, and n-BuOH and 85% aq.MeOH fractions showed the best activity among solvent fractions. However, the crude extract and the solvent fractions did not show significant activity for NO production inhibition. Since polyphenol content analysis showed that the n-BuOH and 85% aq.MeOH fractions contained high polyphenol content, the antioxidant and antiproliferative effects of these solvent fractions may be partially due to polyphenols. Therefore, these results suggest that A. japonica may be a good source for development of antioxidants and anticancer drugs.

A study of Bangladesh income inequality and regional development policy : 방글라데시 소득불평등과 지역발전정책 연구

PRINCESS SHAHIDA HAQUE Graduate school of Korea Maritime & Ocean Universi 2023 국내석사

Bangladesh's incredible accomplishments in both its economy and society have propelled the country to heights previously unimaginable. Using newly harmonized satellite income data from 2001 to 2020, we examine economic convergence across 63 districts in Bangladesh. Income growth, as a proxy for regional economic activity, demonstrates overwhelming evidence of absolute convergence. Estimating methods founded on the basic neoclassical model of economic convergence and built to account for the effects of catastrophic events reveal virtually no evidence of progress. Based on panel data collected between 2001 and 2020, this study examines the evolution, shifting trend, and level of income inequality in the various regions (provinces) of Bangladesh. The second section of this essay examines the development of Bangladesh's regional development policies since the country's creation. This essay's third section examines the issues and solutions brought about by recent research and em-pirical research on the effects of income inequality that occurs between the eight major areas of Bang-ladesh. The fourth section of this essay recommended some regional policies based on the previous analysis. In order to stop the income inequality between the various regions of Bangladesh from in-creasing, this article suggesting certain countermeasures. Lastly, the conclusions drawn in the preceding sections, the fifth section of this essay attempts to explain the overall change that occurs in relation to regional income inequality. The Bangladeshi government's regional policy has had an enormous effect on this transformation.