• Journal of Navigation and Port Research
• /
• v.47 no.4
• /
• pp.191-201
• /
• 2023

The provision of onboard Internet services is recognized as one of the measures to enhance the appeal of seafarers and improve seafarer welfare. This study aims to investigate the influence of seafarers' leisure activities using the Internet on shipboard culture. Shipboard culture was examined using Hofstede's cultural dimensions theory. An empirical analysis was conducted on crewmembers regarding their Internet-based leisure activities and the shipboard culture. As a result, it was observed that sociability activities through the Internet while onboard significantly influenced power distance, uncertainty avoidance, and long-term orientation. The investigation of shipboard culture revealed uncertainty avoidance, masculinity, and long-term orientation, along with low power distance and individualism cultures. In addition, an analysis of shipboard culture according to seafarers' characteristics showed significant differences in certain shipboard cultures based on seafarers' attributes.

• The Journal of Korean Association of Computer Education
• /
• v.14 no.3
• /
• pp.51-62
• /
• 2011

Navigability refers to how easy a user can find desired information in a web site and is influenced by the structure of a web site. In this paper, we created three types of Web sites, that is a Web site whose structure forms a small world, a Web site whose structure forms a semi-matroid, and a Web site based on an ontology and measured the navigability of each Web site based on two criteria (the number of hyperlinks clicked by users to find the desired information and the elapsed time for finding the desired information). The reason that we selected three structures is because hyperlinks can be created in a way that helps a user find desired information in each site. From the experiments, we found that the average number of hyperlinks which a user clicked to find out the desired information was as follows: a Web site that had semi-matroid property (100.37 hyperlinks) < a Web site that was created based on an ontology (117.63 hyperlinks) < a Web site that had small-world property (236.17 hyperlinks). In addition, we found that the average elapsed time during which a user found out the desired information was as follows: a Web site that was created based on an ontology (20 min 26 sec) < a Web site that had semi-matroid property (23 min 6 sec) < a Web site that had small-world property (30 min 47 sec). Therefore, we can consider a Web site that is created based on a semi-matroid or an ontology is relatively more navigable than a Web site that has small-world property. In this paper, we also propose a way by which our experimental results can be reflected in designing an educational Web site.

• Journal of Power System Engineering
• /
• v.13 no.2
• /
• pp.63-70
• /
• 2009

This paper discusses the influence on long-tenn predictions of the ship response in ocean by using the Global Wave Statistics data, GWS, and wave information from the remote sensing satellites. GWS's standard scatter diagrams of significant wave height and zero-crossing wave period are suggested to be corrected to a round number of 0.01/1000 fitted with a statistical analytic model of the conditional lognormal distribution for zero-crossing wave period. The GEOSAT satellite data are utilized which presented by I. R. Young and G. J. Holland (1996, named as GEOSAT data). At first, qualities of this data are investigated, and statistical characteristic trends are studied by means of applying known probability distribution functions. The wave height data of GEOSAT are compared to the data observed onboard merchant ships, the data observed by measure instrument installed on the ocean-going container ship and so on. To execute a long-tenn prediction of ship response, joint probability functions between wave height and wave period are introduced, therefore long-term statistical predictions are executed by using the functions.

• Journal of Navigation and Port Research
• /
• v.44 no.1
• /
• pp.44-52
• /
• 2020

More accurate forecasting of port cargo in the global long-term recession is critical for the implementation of port policy. In this study, the Busan Port container volume (export cargo and transshipment cargo) was estimated using the Vector Autoregressive (VAR) model and the vector error correction (VEC) model considering the causal relationship between the economic scale (GDP) of Korea, China, and the U.S. as well as ARIMA, a single volume model. The measurement data was the monthly volume of container shipments at the Busan port J anuary 2014-August 2019. According to the analysis, the time series of import and export volume was estimated by VAR because it was relatively stable, and transshipment cargo was non-stationary, but it has cointegration relationship (long-term equilibrium) with economic scale, interest rate, and economic fluctuation, so estimated by the VEC model. The estimation results show that ARIMA is superior in the stationary time-series data (local cargo) and transshipment cargo with a trend are more predictable in estimating by the multivariate model, the VEC model. Import-export cargo, in particular, is closely related to the size of our country's economy, and transshipment cargo is closely related to the size of the Chinese and American economies. It also suggests a strategy to increase transshipment cargo as the size of China's economy appears to be closer than that of the U.S.

• Journal of Navigation and Port Research
• /
• v.46 no.3
• /
• pp.251-258
• /
• 2022

Donghae Port is adjacently located to a residential area wherein 26,933 generations are creating a living environment. The areas comprise Song-jeong village (5,754 generations) and Bukp-yeong village (21,179 generations). Major cargoes handled in Donghae Port are dusty limestone, cement, anthracite, and bituminous coal, etc. In the process of handling such cargoes, air pollutants including oxide dust and fine dust which adversely impact the living conditions and health of residents are generated, causing air pollution in the vicinity of the port. Currently, Donghae Port is making an effort to improve the operation environment of the infrastructure and equipment in stages, for the purpose of reducing air pollutant emissions caused by the port industries in a long-term perspective. In this study, the sphere of influence of fine dust exposure and the degree of air pollution in the surrounding area were analyzed such as the state of fine dust concentration and diffusion in the vicinity of Donghae Port, fine dust diffusion pattern and spatial distribution of high-concentration considering wind direction and speed characteristics during the day and seasonal cycles. A more effective plan to reduce the concentration of fine dust in nearby areas by combining reduction plan, is being developed in terms of improvement regarding port infrastructure and equipment, and reduction measures considering the characteristics of the atmosphere environment according to the daytime, nighttime and season.

• Journal of Navigation and Port Research
• /
• v.32 no.1
• /
• pp.1-7
• /
• 2008

Since the shipbuilding industry is at its peak to assimilate the large volume of orders in recent years, the Floating Dock has been an alternative to the dry dock which takes a certain period of time to build. Hence the use of Floating Dock is steadily increasing. Since the Skid Launching System(SLS) is used in Floating Dock, the balancing of the ship while launching is important and achieved by adjusting the Ballast tank of the Floating Dock. In this paper a Floating Dock Control Simulator for SLS is developed through the on-line interface of VRC(Valve Remote Control), Tank Level & Draft Measuring System and Valve Control algorithm on Simulation Tank Plan.

• Journal of Navigation and Port Research
• /
• v.29 no.3 s.99
• /
• pp.257-262
• /
• 2005

Environmental problems and safety problems in coastal area is one of the most important factors for designing coastal structures and maintaining facilities in coastal zone. And thus study on Wave transformation around coastal area is very important to develope a new port or on industrial area. Delft 3D-WAVE is applied to Ulsan new port area and the culculated results are analysed and compared with measured data Delft 3D-wave module is based on SWAN model which considers wave shoaling and refraction for irregular wave. This module also covers wind effect, bottom friction. white-capping and wave breaking effect. The results of this study show a good agreement with measured data and thus Delft 3D-WAVE module can be applied to simulate irregular wave transformation in coastal area.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
• /
• 2007.12a
• /
• pp.198-199
• /
• 2007

Relation between SSTs(Sea Surface Temperatures) in the South Sea and intensity of typhoons which passed through the South Sea was analyzed for 36 years from 1970 to 2005. The SSTs in the South Sea show the rising trends continuously. The mean SST of the last 6 years(2000-2005) is higher 1.21$^{circ}C$ than the mean SST during 10 years(1970-1979). The rising trends are especially strong after 1994. The intensity of typhoon am be seen by the central pressure. The minimum central pressures of typhoons which passed through the South Sea show the descending trends. The mean minimum central pressure of the last 6 years(2000-2005) is lower 9hPa than t1m during 10 years(1970-1979). The correlation analysis shows that the rising of SSTs in the South Sea has relations with the strengthening of intensity of typhoons.

• Journal of Navigation and Port Research
• /
• v.32 no.5
• /
• pp.403-407
• /
• 2008

Relations between variation of SSTs(sea surface temperatures) in the South Sea of Korea and intensity of typhoons which passed through the South Sea of Korea was analyzed for 36 years from 1970 to 2005. The SSTs in the South Sea show the rising trends continuously. The mean SST of the last 10 years(1996-2005) is higher $1.03^{\circ}C$ than the mean SST during 10 years(1970-1979). The rising trends are especially strong after 1994. The intensity of typhoon can be shown by the minimum sea level pressure. The minimum sea level pressures of typhoons which passed through the South Sea show the descending trends. The mean minimum sea level pressure of the last 10 years(1996-2005) is lower 10.1hPa than that during 10 years(1970-1979). The correlation analysis shows that the rising of SSTs in the South Sea has relations with the strengthening of intensity of typhoons.

• Journal of Navigation and Port Research
• /
• v.30 no.6 s.112
• /
• pp.433-438
• /
• 2006

Recently, the earth scale disaster is occurring frequently. Under the effects of global warming, the weather has become unseasonable worldwide. Hence, the earth is experiencing unstable condition with many disasters such as storms and flood damages as well as earthquake. Therefore, it is necessary to consider what we am do to prevent disasters. Consequently, recent warnings indicate that there is a potential risk of massive earthquakes. Consideration of the effects of tsunami to the moored ship is very important. Operational problems such as moored ship motions sometimes become remarkable with large amplitude and long periods in harbor. Moored ship motions may cause the breakage of mooring systems such as mooring lines, fenders or quay. Large and long period moored ship motions are caused by resonant effects. In this paper, the moored ship motions within a harbor by the large-scale tsunami and the effects on the motions and mooring loads with resonant effects are investigated by numerical simulations.