• Journal of Fisheries and Marine Sciences Education
• /
• v.26 no.4
• /
• pp.749-759
• /
• 2014

With the rapid development of global economic and trade, the ports in the North-east Asia region have developed rapidly. Ocean shipping plays an irreplaceable role in China's foreign trade. Improvement of China's economy and continuous increase of trade in North-East Asia have made China as the number one in the world in container transport. Tianjin port which is the biggest international trade port in North-east China. Tianjin Binhai New District has incorporated in (CPC Central Committee on the outline of the Eleventh Five-Year Plan for national economic and social development proposals) which had adopted by The Fifth Plenary Session of the 16th CPC Central Committee. However, the competitions between ports are getting intense, the construction of Northeast Asia shipping center is in the ascendant, which bring new opportunity and challenge to the development of Tianjin port logistics. Therefore, Tianjin should according to its characteristics, integrating port resources, exert great efforts in developing port logistics, thus promoting regional economic development. Therefore, it is necessary to make the main study on the development strategy of Tianjin port logistics.

• Journal of the Korean earth science society
• /
• v.40 no.5
• /
• pp.502-517
• /
• 2019

Global warming and rapid climate change have long affected the characteristics of typhoons in the Northwest Pacific, which has induced increasing devastating disasters along the coastal regions of the Korean peninsula. Synthetic Aperature Radar (SAR), as one of the microwave sensors, makes it possible to produce high-resolution sea surface wind field around the typhoon under cloudy atmospheric conditions, which has been impossible to obtain the winds from satellite optical and infrared sensors. The Geophysical Model Functions (GMFs) for sea surface wind retrieval from SAR data requires the input of wind direction, which should be based on the accurate estimation of the center of the typhoon. This study estimated the typhoon centers using Sentinel-1A images to improve the problem of typhoon center detection method and to reflect it in retrieving the sea surface wind. The results were validated by comparing with the typhoon best track data provided by the Korea Meteorological Administration (KMA) and Japan Meteorological Agency (JMA), and also by using infrared images of Himawari-8 satellite. The initial center position of the typhoon was determined by using VH polarization, thereby reducing the possibility of error. The detected center showed a difference of 23.76 km on average with the best track data of the four typhoons provided by the KMA and JMA. Compared to the typhoon center estimated by Himawari-8 satellite, the results showed an average spatial variation of 11.80 km except one typhoon located near land with a large difference of 58.73 km. This result suggests that high-resolution SAR images can be used to estimate the center and retrieve sea surface wind around typhoons.

• Journal of Engineering Education Research
• /
• v.13 no.5
• /
• pp.66-71
• /
• 2010

Recently, engineering work become very important for the leaders of the information society for the future knowledge in the 21st century and the goal of engineering education is to prepare people to practice engineering as a profession and also to spread technological literacy, increase student interest in technical careers through science and math education. The College of Engineering (COE) of Korea Maritime University (KMU) aims to be the center of both IT-related high industrial technology and the industries related to port, shipbuilding and the ocean. Especially COE focuses on the educational principles to contribute to the development of the country and the regional communities by educating specialists that have international competitiveness. With the need to expand international collaboration in terms of engineering work, it is proposed to initiate a new state of the Asian-Pacific body of engineering conference. To the extent possible the basic discussion was made to expose elements and supports as full-scale illustration of the engineering conference. The result is a body that evokes multi agreement and joint declaration among members.

• Ocean and Polar Research
• /
• v.37 no.2
• /
• pp.149-159
• /
• 2015

The Southern Ocean (SO) plays a primary role in global climate by storing and transporting anthropogenic carbon dioxide through the meridional overturning circulation and the biological pumping process. In this study, we aim to investigate interannual variability of summer chlorophyll concentration in the SO and its relation with the El $Ni{\tilde{n}}o$ Southern Oscillation (ENSO), using satellite ocean color data covering 16 years from 1997 to 2012. During El $Ni{\tilde{n}}o$ periods, chlorophyll concentration tends to increase in the subtropics (north of the subantarctic front). This chlorophyll increase is likely linked to El $Ni{\tilde{n}}o$-induced surface cooling that increases nutrient supply through enhanced vertical mixing in the subtropics. On the other hand, the subpolar gyres show localized chlorophyll changes in response to the ENSO. The localized response seems to be primarily attributed to changes in sea-ice concentrations. Our findings suggest that ENSO contributes interannual variability of chlorophyll in the SO through different mechanisms depending on regions.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.53 no.5
• /
• pp.707-716
• /
• 2020

Red sea cucumber Stichopus japonicus, was dried using three methods-far-infrared ray, vacuum, and freeze drying and then enzymatically hydrolyzed using nine proteases: Alcalase, Flavourzyme, Kojizyme, Neutrase, Protamex, trypsin, α-chymotrypsin, and papain. In addition, the potential ability of hydrolysates to inhibit lipid accumulation in 3T3-L1 adipocytes was evaluated. The yield of hydrolysates from red sea cucumbers dried using each method was higher than that of the distilled water extract, and protein contents were either similar or higher. The hydrolysates that exhibited inhibitory effects on lipid accumulation, as demonstrated via Oil red O staining, were those obtained by far-infrared ray drying coupled with Alcalase, Flavourzyme, Kojizyme, or Neutrase treatment. In addition to the advantages of far-infrared drying and the characteristics of Flavourzyme, the Flavourzyme hydrolysate of far-infrared-dried red sea cucumber showed the highest inhibitory effect on lipid accumulation. In addition, this hydrolysate significantly decreased the expression of the protein factor fatty acid-binding protein 4, which is related to the late differentiation of 3T3-L1 adipocytes. Taken together, these results suggest that Flavourzyme hydrolysates from farinfrared-dried red sea cucumber may be used as a functional food and/or a pharmaceutical ingredient for the inhibition of lipid accumulation.

• Journal of Ocean Engineering and Technology
• /
• v.23 no.1
• /
• pp.67-73
• /
• 2009

This study presents the results of a slamming experiment using a pneumatic cylinder. The employment of the pneumatic cylinder showed a relatively good repeatability when the results were compared with those of other slamming devices. The experiment was done for various incident angles. An air pocket was believed to cause a reduction in the magnitude of the impact pressure with an incident angle of $0^{\circ}$ for the water entry. A high speed camera was used in an attempt to locate the time of the contact between the bottom of the specimen and the free surface. It seemed that the maximum pressure occurred before the water contacted the bottom of the specimen.

• Membrane and Water Treatment
• /
• v.14 no.3
• /
• pp.107-114
• /
• 2023

Graphene oxide (GO) membranes have attracted extensive attention in water treatment and related fields. However, GO films are unstable and have low permeability, which have hindered their further development. In this paper, a simple and effective method was used in which GO and single-layer graphene (GN) were mixed, and the layer spacing was effectively controlled by accurately controlling the ratio of GO to GN. GO-GN composite membranes have excellent stability, salt rejection (95.4%), and water flux (26 L m^-2 h^-1 bar^-1). This unique design structure can be used for precise and effective regulation of the layer spacing in GO, improving the rejection rate, and increasing water flux via the enhancement of low-friction capillary action. The rational development and use of this unique composite membrane provides a reference for the water treatment field.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.54 no.1
• /
• pp.73-79
• /
• 2021

The feeding habits of Chub mackerel Scomber japonicus were investigated using 329 specimens collected from coastal waters of the South Sea of Korea. S. japonicus is mainly a piscivore, consuming small fish such as Engraulis japonicus (%RI: 81.0 %). The diet of Chub mackerel also includes small quantities of thaliaceans, euphausiids, and amphipods. We calculated the trophic level as 3.92 for S. japonicus. The dietary composition of S. japonicus did not show significant differences with size, but differed with season. As the body size of S. japonicus increased, the mean weight of prey within the stomach (mW/ST) increased (One-way ANOVA, P<0.05).

• Journal of Engineering Education Research
• /
• v.26 no.4
• /
• pp.11-21
• /
• 2023

In engineering education, stimulating students' questions and encouraging learning participation are crucial for achieving higher-order thinking abilities. This study aims to investigate the use and effect of an online communication channel in fostering engineering students' questioning abilities. Consequently, in this research, we gauged students' satisfaction with an engineering class that implemented a communication channel, and scrutinized the changes in their perceptions regarding the significance of questions, their engagement in learning, and their academic self-efficacy. In addition, we interviewed the students who participated in the class. The outcomes are as follows: Firstly, student satisfaction improved compared to the previous semester's class where the communication channel was not utilized. Secondly, learners' understanding of the importance of asking questions positively escalated, alongside their actual frequency of posing questions. Thirdly, there was an improvement in learners' active engagement in their studies and their academic self-confidence. The findings of this research suggest that communication channels should be employed to motivate learners to pose questions and involve students in effective learning.

• Fisheries and Aquatic Sciences
• /
• v.25 no.11
• /
• pp.549-558
• /
• 2022

The Indonesian Archipelago has a very complex geological history, along with equatorial warm sea temperature, resulting in diverse types of coral reefs and high diversity of coral reef fish. Many livelihoods of the coastal community are dependent on coral reef fisheries. The present study aimed to determine which region and location in the Indonesian Archipelago has the most diverse and abundant coral reef fish. The archipelago was divided into four regions: the Indian Ocean, Sunda Shelf, Wallacea, and the Pacific Ocean. Data were obtained from a national coral reef monitoring program of the Indonesian Research Center for Oceanography (RCO)-the National Board for Research and Innovation (BRIN). The reef fish data were collected using the underwater visual census method, from 321 belt transects on 24 locations (districts) across the archipelago. The results show that coral reef fish diversity of the Pacific region was the highest across the archipelago for all three trophic levels, i.e., corallivore, herbivore, and carnivore fish. The Pacific Ocean region also had the highest fish abundance for the three trophic levels. Comparison among locations revealed that the best ten locations in reef fish diversity and abundance were Sabang, Mentawai, Makassar, Selayar, Buton, Luwuk, Ternate, Raja Ampat, Biak, and Wakatobi. Wakatobi reefs showed their supremacy in carnivore fish diversity and abundance, while Biak reefs were the best in herbivore fish. The abundance of corallivore fish was also considerably high in Sabang reefs, but it is still lower than in Raja Ampat, Biak, and Wakatobi reefs. These results provide empirical evidence that the coral reefs of Wakatobi and Biak are the hottest hotspots of coral reef fish diversity and abundance in the Indonesian Archipelago.