• Journal of Korean Port Research
• /
• v.11 no.2
• /
• pp.305-320
• /
• 1997

The objective of this paper is to analysis & forecast on the change in spatial structures of southeast region by development of the Seoul-Pusan high-speed Rail. To measure the spatial structures, it was used the method of mean center and standard distance among of centrographic measures as analytical tools. The changes of spatial structures patten over time and space in the southeast region were surveyed using population and employment data of 57 zones. And also, to forecast the spatial structures of the southeast region after opening of the Seoul-Pusan high-speed rail, it was supposed three(3) scenarios which designed using influential area with centering around of the proposed high-speed rail stations. Therefore, the results of this research indicate as follows; 1) The spatial structures of population is showed a trend of continual concentration toward Ulsan city area, and also the spatial structures of employment is showed a trend of continual dispersion over time. 2) The forecast of three93) scenarios supposed after opening of the Seoul-Pusan high-speed rail in 2006 show a change of the spatial structures with both population concentration and employment dispersion. In the meantime, the rapid increase of population and wide dispersion of employment is reform with centering around HSR stations which builted in the southeast region after opening of high-speed rail. 3) It shall furnish valuable data to establish the development strategy of urban and local region, and also forecast the change of spatial structures about population and employment in influential area which passed on high-speed rail line & stations by method of mean center and standard distance among of centrographic measures as analytical tools.

• Journal of Digital Convergence
• /
• v.18 no.7
• /
• pp.37-46
• /
• 2020

The aim of this research is to analyze the concentration and deconcentration development of cruise ports in the Mediterranean area by utilizing the concentration ratio (CR), the Herfindahl-Hirschman Index (HHI), the Gini coefficient, and shift share analysis (SSA). The results of analysis indicated a concentration trend in the West Mediterranean. The cruise ports located in Venice, Piraeus, Naples and Livrno in Adriatic and East Med region lost cruise passengers, while the those in West Mediterranean gained the passengers and showed the trend of concentration. This paper providing the shifting passengers among cruise ports that indicates the competitiveness of cruise ports for industrial stake holders to better understand the cruise ports such as tourist boards, ship agents, and port agents.

• Journal of Environmental Science International
• /
• v.31 no.6
• /
• pp.503-513
• /
• 2022

This research investigated the effect of the eruption of Japan Sakurajima volcano on the concentration of ultrafine particle when the north Pacific high pressure exists in the Busan in summer. As a result of analyzing the forward trajectory using the HYSPLIT model, the air parcel from Sakurajima volcano passed through the sea in front of Busan at 1500 LST on July 17, 24 hours after the volcanic eruption. As a result of analyzing the PM₁₀ and PM_2.5 concentrations in the Busan for two days from July 16 to 17, 2018, the Sakurajima eruption in Japan, it can be seen that there was a high increase in PM₁₀ and PM_2.5 concentrations compared to the previous day. As a result of analyzing the backward trajectory, the air mass that reached Busan at 1300 LST on July 17, 2018 has moved near the Sakurajima volcano at 1,500 m, 2,000 m, and 3,000 m. The concentration of SO₄^2- in PM_2.5, the concentration of all three stations in Busan showed a sharp increase from 1000 LST on July 17th. Looking at the NH₄⁺ concentration in PM_2.5, it shows a very similar variation trend to SO₄^2-, and the correlation coefficient between the two components is 0.96 for Jangrimdong and Yeonsandong, and 0.85 for Busan New Port. Looking at the NO₃^- concentration in PM_2.5, the same high concentrations as SO₄² and NH₄⁺ were not observed in the afternoon of July 17th.

• Journal of Korean Society of Water and Wastewater
• /
• v.22 no.3
• /
• pp.389-396
• /
• 2008

The hybrid model can be used to predict the initial near field mixing and the far field transport of the buoyant jets, which are discharged from the submerged wastewater ocean outfall. In the near field, the jet integral model can be used for single port diffusers while the ${\sigma}$ transformed particle tracking model was used in the far field. In this study, the experimental study was performed to verify the developed hybrid model in the previous research. The developed hybrid model properly predict the surface and vertical concentration distribution of the single buoyant jets with various effluent and ambient conditions. The hybrid model can also simulate the surface concentration distribution of the rosette diffuser except for the parallel diffuser with the higher densimetric Froude number due to the assumption that dynamic effects of the effluent plumes are negligible in the far field. The application of the hybrid model to rosette diffusers can predict the concentration near the diffuser more accurately when the line-plume approximation is used.

• Journal of Environmental Science International
• /
• v.24 no.8
• /
• pp.1075-1084
• /
• 2015

This study was conducted to investigated the changes in the nutrient components ($NO_3{^-}-N$, $NH_4{^+}-N$, $PO_4{^{3-}}P$, $K^+$, $Ca^{2+}$, and $Mg^{2+}$) and environmental parameters (electrical conductivity, total dissolved solids and pH) on the leaf lettuce (Lactuca sativa L.) grown with hydroponics. Recirculating hydroponic cultivation system was consisted of planting port, LED lamp, water tank, and circulating pump for hydroponic. Nutrient solution was used in the standard solution for Japan vegetables experimental station and commercial hydroponic. The result showed that electrical conductivity (EC), total dissolved solids (TDS) and pH, depending on the growth of lettuce decreased continuously. With the growth of the lettuce, nitrate nitrogen, ammonia nitrogen, phosphate phosphorus were required for periodic replacement. The number of pH compensation due to the growth of lettuce are the most high. The concentration of $Ca^{2+}$ and $Mg^{2+}$ during the lettuce growth showed no significant change. However, $K^+$ concentration increased due to the replacement with nitrogen and phosphorus. Electric conductivity and total dissolved solids with total nutrient concentration showed the linear relationship and the correlation coefficient $R^2$ were 0.8601 and the 0.827, respectively.

• Journal of Environmental Science International
• /
• v.28 no.5
• /
• pp.495-502
• /
• 2019

This study was conducted to investigated the possibility of inactivating wilt germs (Fusarium oxysporum f. sp. radicis lycopersici) using Dielectric Barrier Discharge (DBD) plasma in a hydroponic system. Recirculating hydroponic cultivation system for inactivation was consisted of planting port, LED lamp, water tank, and circulating pump for hydroponic and DBD plasma reactor. Two experiments were conducted: batch and intermittent continuous process. The effect of plasma treatment on Total Residual Oxidants (TRO) concentration change, Fusarium inactivation and growth of lettuce were investigated. In the batch experiment, most of the Fusarium was inactivated at a TRO concentration of 0.15 mg/L or more at four-day intervals. There was no change in lettuce growth after two times of plasma treatment for one week. The intermittent continuous experiment consisted of 30-minute, 60-minute, and 90-minute plasma treatment in 2 day intervals and 30-minute treatment a one-day; most of the Fusarium was inactivated only by treatment for 30-minute every two days. However, if inactivation under $10^1CFU/mL$ is required, it will be necessary to treat for 60 minutes in 2 day intervals. The plasma treatment caused no damage to the lettuce, except the 30 min plasma treatment ay the one-day interval. It was considered that the residual TRO concentration was higher than that of the other treatments.

• Journal of Korea Port Economic Association
• /
• v.33 no.3
• /
• pp.105-120
• /
• 2017

This study analyzed changes in the competitive structure of the global shipping container market and the appropriate capacity of the container fleet in Korea from three perspectives. The competitive market analysis applied the market concentration ratio and Hirschman-Herfindahl index, while the appropriate capacity analysis was based on the following three aspects: (1) Fleet capacity to secure competitiveness in the global shipping alliance; (2) Fleet capacity to increase national fleet coverage of domestic import and export container cargo; and (3) Fleet capacity analysis through the panel model considering the characteristics of the major shipping countries. Analysis of the global shipping container market reveals an oligopoly industry, and Korea's container fleet capacity is insufficient across all three analyses.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
• /
• 2010.04a
• /
• pp.59-60
• /
• 2010

Unlike cases of fire on land where experienced fireman and various fire fighting equipment are present, onboard fires need to be independently extinguished, making it a complex process. The primal objective of getting quick control of a fire is to prevent casualties which generally occur from inhalation of toxic fumes rather than the fire itself. However, if for some inevitable reason the fire cannot be contained, everyone in that particular area must evacuate to avoid any possible casualties. In this research, through a simulation of the CFD, we will observe the soot density concentration which affects evacuation within an onboard fire in relation to the possible evacuation time to conclude a time zone for a safe exit.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
• /
• 2004.04a
• /
• pp.241-246
• /
• 2004

We studied field observation and countermeasure about the effluent of sediment and nutrient materials on the Okinawa Ishigaki Coast according rainy season. though this observation, we found out the analysis of outflow topography, intensity of rainfall and effects on the tide, the property of effluent materials etc. The sediment and nutrient concentration of the Okinawa Ishigaki coast are different on the regional sites according to vary with time variation of intensity of rainfall and the ebb and flow. We could confirm to vary with utilized waterways land area and distribution of surrounding vegetation.

• Journal of Korea Port Economic Association
• /
• v.22 no.4
• /
• pp.39-58
• /
• 2006

This case study for a homeshopping company shows that the management of returned apparels by the partnership system increases the velocity of the returned goods, which not only minimizes the products' value loss but also improves the company's management performance. By incorporating the partnership system, following significant performance improvements have been identified: First, decrease in transaction cost and time between the homeshopping company and the partnering companies. Second, concentration of production line, accurate schedule management of receipt/delivery as well as collection of goods. Third, improvement of efficiency in procedures of returned goods and quality improvement of product provided by the partner.