• Journal of the Korean Society of Marine Environment & Safety
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• v.23 no.7
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• pp.941-947
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• 2017

Increasing marine transportation of dangerous goods using containers causes fire accidents on ships due to leakage of dangerous materials. In IMO (MSC.93), all vessels that are to be loaded five or more containers on weather deck area after 1 January 2016 are required to have a fire extinguishing system called Water Mist Lance (WML) on board. In this study, numerical analysis is performed to design WML with optimal edge radius of curvature using LS-DYNA. The analysis results for the three models with 10 mm, 15 mm and 20 mm lengths of the edge part showed that the only model with 15 mm length penetrated the wall of the container and did not cause damage to the edge of the WML. In the future, based on the results of this study, we will make a WML of prototype and conduct a performance test. And we will continue to improve the problems.

• The Korean Journal of Mycology
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• v.3 no.2
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• pp.19-23
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• 1975

A study on the variation of the air temperature in the pine mushroom box containing dry ice for the preservation of the freshness of the pine mushroom, Tricholoma matsutake (Ito et Imai) Sing. produced in Korea was made in Seoul, Korea during the period of August 1 to 30, 1975. A safe shipment of 5 kg (net weight) of fresh mushrooms with freshness preserved for 24 hours in August required the placement of 4.5 kg of dry ice-a half in the upper portion and the other half in the middle portion-in an airtight container (mushroom box). The container used for the shipment test, made of 3mm-thick double-layer cardboard, was of the dimensions : $0.33{\times}0.4{\times}0.5=0.066(m^3)$. As the temperature fell, decreased amounts of dry ice were needed : 3 to 2 kg in September and 1.5 to 0.3 kg in October. With this preservation method, large quantities of fresh mushrooms were exported to Tokyo ana Osaka, Japan without damage in the process of transportation.

• Journal of Korean Society of Transportation
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• v.23 no.3 s.81
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• pp.85-94
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• 2005

The scale and operating conditions of logistical systems very sensitively varies according to the variation of traffic intensity that is affected by the arrival characteristics of trucks and the attributes of loading/unloading services in logistics facilities. More exactly, logistics costs are incurred according to variations of traffic intensity. which are intimately linked with in a given time period. Also. although traffic intensity changes minutely, the range of cost variation is wide. Nevertheless, with regard to operating logistics systems, the existing studies make no attempt to analyze these factors. Therefore, it was the purpose of this study to determine the optimal traffic intensity to minimize excessive logistics costs resulting from the generation of unnecessary costs such as waiting costs and overcosts in operating a facility. For the purposes of this analysis. a determination model of optimal traffic intensity was constructed according to queuing theory. The inflow/outflow conditions of trucks and the terminal operational conditions were collected from an off-dock container terminal in Busan. On the basis of this data. the optimal traffic intensity that could off-set excessive waiting and operating costs was determined quantitatively. Also. using the optimal traffic intensity to be determined. we consider the improvements of operating system in the logistics facilities.

• Journal of Digital Convergence
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• v.16 no.9
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• pp.1-10
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• 2018

As the growth of warehouse stores has been accelerated, the importance of logistics for warehouse stores has been also increasing. In this respect, this study analyzed the transportation efficiency after the integrated operation of depots by C Company using GIS. According to the results of analysis of changes in container shipment cargo volumes, in terms of delivery distances, a total of 1,028,699 km of delivery car driving was shown to be necessary when one depot was operated, while a total of 2,866,604km of car driving was shown to be necessary so that 1,028,699km of car driving was reduced per year. In terms of delivery time too, 62 hours of time was saved per day and a total of 36% reduction in time could be expected. This study presented the effects of depot integration and delivery changes to improve operation processes and reduce delivery time and distances using GIS OD Matrix. The results of this study can be used as an important indicator for judgment that can affect the delivery process of other warehouse discount stores.

• Journal of Digital Convergence
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• v.15 no.12
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• pp.273-282
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• 2017

The purpose of this study is to investigate the changes in the recovery of equipment using full containers loaded with freight instead of direct container transportation according to the sales policy considering the cost of transporting the containers. The EMU operation case was analyzed. The policies implemented by Company A to provide EMU credits depended only on the relative accountability contribution margin per box (RA CMPB) for the profitability of backhaul full freight. Therefore, these policies resulted in limitations in sales based on profitable accountability (PA) CMPB, which is more profitable. Moreover, while some Asian regions have surplus equipment, many Asian destinations to which their freight is exported have equipment shortages. Thus, in some cases, service sales to the regions with surplus equipment generated greater company-wide profits when compared with the return of empty containers or sales to the regions with insufficient equipment. In other words, the conditions for providing EMU credits should be changed, and even the full freight between regions with surplus equipment should be provided with credit amounts in which potential factory and transport costs in a destination are pre-reflected.

• Journal of Korea Port Economic Association
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• v.32 no.2
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• pp.105-122
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• 2016

Numerous studies have evaluated the status of seaports. However, the majority of the research has approached this topic from the view-point of port capabilities, including locational advantage, infrastructure, productivity, and competitiveness. The position and/or role of a port can be understood more precisely and comprehensively by considering the interconnectivity among ports making up enormous global transportation networks. The main objective of this study is to compare the status of 82 container ports on the trunk shipping routes between Asia and Europe by applying the concepts of structural equivalence and role equivalence proposed by the social network analysis method. Network similarities and differences among competing ports in the regions are assessed by analysing their structural equivalence. Furthermore, the hierarchical structures of the ports located on the trunks between Asia and Northwest Europe and between Asia and the Mediterranean are constructed by evaluating their role equivalence. The results of this empirical research shows that Singapore and Rotterdam possess the most significant positions on the ocean corridors between Asia and Northwest Europe. Singapore also holds a leading position on the Asia-Mediterranean shipping route. Lastly, no ports located in the Middle East or Mediterranean regions have an equivalent weight to those of Rotterdam, Hamburg, Antwerp on the Asia-Northwest Europe route.

• Journal of Navigation and Port Research
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• v.46 no.1
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• pp.42-56
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• 2022

Due to the 4th Industrial Revolution announced at the Davos Forum, the World Economic Forum, in 2016, industrial trends around the world are changing rapidly and intelligently. Among them, the digital twin is drawing attention from all industries as a groundbreaking technology that reduces unnecessary costs and trial and error by implementing real objects, systems, and environments in the same way in the real virtual world and using them to perform simulation analysis. In particular, there is a lot of interest in the application of digital twin technology in solving ports safety and efficiency challenges at once. However, there is a lack of in-depth research for the application of digital twin technology in the port, and in particular, there is a lack of research on measurable data for the implementation of the digital twin in ports. The purpose of this study was to increase granularity and connectivity through measurable data investigation for the application of digital twin technology at container ports. Based on the study results, data factors for container port application were classified into crane data, operational data, physical data, and transportation data, and factor composition, correlation with factors, and fitness were confirmed through confirmatory factor analysis.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2022.06a
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• pp.391-393
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• 2022

In recent years, technologies forecasting demand based on deep learning and big data have accelerated the smartification of the field of e-commerce, logistics and distribution areas. In particular, ports, which are the center of global transportation networks and modern intelligent logistics, are rapidly responding to changes in the global economy and port environment caused by the 4th industrial revolution. Port traffic forecasting will have an important impact in various fields such as new port construction, port expansion, and terminal operation. Therefore, the purpose of this study is to compare the time series analysis and deep learning analysis, which are often used for port traffic prediction, and to derive a prediction model suitable for the future container prediction of Busan Port. In addition, external variables related to trade volume changes were selected as correlations and applied to the multivariate deep learning prediction model. As a result, it was found that the LSTM error was low in the single-variable prediction model using only Busan Port container freight volume, and the LSTM error was also low in the multivariate prediction model using external variables.

• Journal of Biosystems Engineering
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• v.37 no.1
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• pp.44-50
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• 2012

Purpose: The characteristics of in-transit vibration stress and possible damage to packaged apples were examined. Methods: A simulated transportation environment with a specific power density profile was used for vibration impact experiments to determine the resulting decrease in packaged apple quality. Apples with or without vibration stress were stored at low temperature ($5{\pm}0.8^{\circ}C$, 75-85% relative humidity) for 30 days. Statistically significant differences (p ${\leq}$ 0.05) were found between apples with and without vibration stress for concentration of oxygen ($O_2$; 11.2% and 14.1%, respectively; initially $29{\pm}0.4%$), carbon dioxide ($CO_2$; 26.4% and 21.8%; initially $1{\pm}0.2%$), and ethylene (79.4 ${\mu}LL^{-1}$ and 55.6 ${\mu}LL^{-1}$; initially $14.1{\pm}0.6{\mu}LL^{-1}$) in the headspace of a gas-collecting container after 30 days of storage. Results: Significant differences were also measured for apples with and without vibration stress with respect to soluble solid content (15.4% and 14.9%, respectively; initially $12.9{\pm}0.8%$ and $13.1{\pm}1.1%$), weight loss (10.1% and 8.2%), and firmness (139.7 kPa and 163.3 kPa; initially $213.8{\pm}6.2$ kPa and $209.1{\pm}7.9$ kPa) after 30 days of storage. Conclusions: The vibration stress clearly accelerated the degradation of apple quality during storage, resulting in increased weight loss, soluble solid content, and headspace $CO_2$ and ethylene production, and decreased firmness and headspace $O_2$.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.21 no.3
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• pp.91-96
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• 2015

Fruit and vegetables are subjected to complex dynamic stresses in the transportation environment. During a long journey from the production area to customers using parcel delivery service, there is always some degree of vibration present. Vibration inputs are transmitted from the vehicle through the packaging to the fruit. Inside, these cause sustained bouncing of fruits against each other and container wall. These steady state vibration input may cause serous fruit injury, and this damage is particularly severe whenever the fruit inside the package is free to bounce, and is vibrated at its resonance frequency. The determination of the resonance frequencies of the fruit and vegetables may help the packaging designer to determine the proper packaging system providing adequate protection for the fruit, and to understand the complex interaction between the components of fruit when they relate to expected transportation vibration inputs. Instrumentation and technologies are described for determining the vibration response characteristics of the fruits with frequency range 3 to 150 Hz. The resonance frequency of the pear ranged from 53 to 102 Hz and the amplitude at resonance was between 1.08 and 2.48 G. The resonance frequency and amplitude at resonance decreased with the increase of the sample mass, and they were slightly affected by mechanical properties such as bioyield deformation and rupture deformation. Regression analysis was performed among the relatively high correlated parameters from the results of correlation coefficient analysis.