• Transactions of the Korean Society of Mechanical Engineers A
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• v.41 no.3
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• pp.213-218
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• 2017

In this study, a reverse design of the F-theta lens was proposed for a 2D scanner in remote welding applications. The curvature and distance of the lens were set as variables, and the focal length of the lens was set as the marginal ray height. The ZEMAX commercial software was used to perform a simulation with unlimited iterations for the optimization process. The target value was optimized using the internal Merit function with the weight factors of focal length and spot diameter. The number of lenses was four, and the focal length obtained from the results was 135mm that is slightly less than that of the commercial lens, which is set with a focal length of 185 mm. The calculated spot diameters are $1.3{\mu}m$, $6.2{\mu}m$, and $16.1{\mu}m$ for $0^{\circ}$, $12.5^{\circ}$ and $23^{\circ}$ of incident laser beam, respectively. It is expected that an optimized lens design is possible by performing the reverse design of a lens by the ray tracing method.

• The Journal of the Korea Contents Association
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• v.15 no.11
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• pp.83-92
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• 2015

This study identifies problems of the administrative legislation (or the delegated legislation) by analyzing articles of laws, orders, and ordinances regarding the sinking of Sewol. According to the result, both of Rescue and Aid at Sea and in the River Act and Marine Transportation Act require to be complemented by additional administration legislations. Therefore bureaucrats enacted defective orders and ordinances, which became an institutional background of the sinking of Sewol. In other words, excessive administrative legislations enabled the Marine Rescue and Savage Association to exert exclusive authorities and caused insufficiencies of supervision over the Association and management for safe navigations. They resulted in corrupt relationships between bureaucrats and businesses and eventually brought citizens' lifes in mortal danger. Consequently, specialty of congressmen should be improved to avoid these excessive administration legislations. At the same time, autonomous control of the administration itself should get enhanced to regulate them. The theoretical implication of this study is that problems of the administrative legislation and necessity of the control by the National Assembly, which have been discussed abstractly and normatively, are clarified empirically, and the practical implication is that the institutional background of the sinking of Sewol is clarified and solutions to improve the institutions are proposed.

• Environmental and Resource Economics Review
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• v.19 no.2
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• pp.341-360
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• 2010

The goal of this study is to forecast the scales of seaborne trade of iron ore and coal. It is assumed that the seaborne trade of iron ore is the function of two independent variables(crude steel production, world GDP) and the seaborne trade of coal is the function of two independent variables(crude steel production, world electricity generation). The result shows that the regressions of two functions are statistically significant respectively. As the results of forecasting, the seaborne trade of iron ore in 2010 may be 892 million tons which is increased 5.1% compare to the level of 2009. Also the seaborne trade of coal in 2010 may be 827 million tons which is increased 6.1% compare to the level of 2009. In terms of the compound annual growth rate, it is forecasted that the iron ore may show 4.7% of increasing rate from 2009 to 2015 and the seaborne trade of coal may be increased 6.1% annually for the same period.

• Journal of the Korean Geographical Society
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• v.44 no.6
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• pp.723-744
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• 2009

The purpose of this paper is to clarify the prospects and problems in the study of geography related to the concept of commodity, transport, and supply chains. The geography studies related to commodity chains are expanded to each field of industry focusing on the subjects and economic difference which lead the commodity chain in core and periphery regions. These vertical connection are studied with the political economy approach that gives attention to geographical pattern of agricultural products and foods. But in viewpoint of commodity circuit and commodity network, the culture or subjects of micro regions and interaction are also studied. The contents of these study are to clarify the importance of cultural turn and local. And the study of chain standpoint appears that the series of transport process by transportation modes can be understood by transport chains and the physical distribution process of sea freight is to be grasped by supply chains.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.35 no.9
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• pp.1035-1040
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• 2011

This research was performed on a microfilter made of a hybrid material (ceramic + metal) that was coated with ceramics on the metal-filter surface by using the thermal spray method. The ceramic powders used were $Al_2O_3+40TiO_2$ powder with a particle size of $20{\mu}m$ and $Al_2O_3$ (98%+)powder with a particle size of $45{\mu}m$. The metal filters were filter-grade $20{\mu}m$, $30{\mu}m$, and $50{\mu}m$ sintered metal powder filters (SIKA-R 20 IS, 30 IS, 50 IS; Sinter Metals Filters) and filter-grade $75{\mu}m$ sintered mesh filter with five layers. Ceramic-coated filters that were coated using the thermal spray method had a great influence on powder material, particle size, and coating thickness. However, these filters showed a fine performance when used as micro-filters.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• v.9 no.1
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• pp.511-514
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• 2005

The application service to use recently an electronic tag have been activated. Therefore research about a data processing of an electronic tag have been processed widely. Therefore, object information to be collected efficiently from various former tag for requesting a data processing of XML based on used widely in Web. For this EPCIS defined the standard interface to share EPC relation data. Currently, Core Event Type of EPCIS defined the Core Type to need in EPC network currently and Types about a business context do not define according to Apply field. We apply to EPC network to a specific business We need the type about the information which defines with Core Event Type. in this paper. We are defining an reusable object type which is used often in a business area. in this way design the schema based to an object information data model of a marine logistics apply to the object type to define in this way and Core Event Type to define EPCIS Specnt.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2006.06b
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• pp.405-410
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• 2006

World port and shipping market are changing dynamically, now 9,000TEU vessel made a maiden voyage and served liner service. So world ports try to occupy leading position and they are changing their regulations and law. Because port logistics industry's importance is bigger than before and when shipping companies select port, it is related with improvement of service quality. Tally is indispensable element in port logistics industry but overlooking its importance. Also, now we can't find any papers or reports about tally, so this paper suggests the direction that go forward about domestic tally guideline through present condition through investigation and question's analysis.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2009.06a
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• pp.194-195
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• 2009

According to the issue "global warming", many regulations and agreements with countries in the world are becoming set and it is being fulfill now. Under the progress of Post Kyoto Protocol agreement, It will be sure that Korea rave a duty to reduce $CO_2$ emission from 2013. For them, Korea have to make a strategies about the Climatic Change Convention for all industries. Recently, a great attention about $CO_2$ emission in the world is focused on port, shipping line and airline. Most countries are establishing policies to prevent environment from these industry fields, but Korea has not yet made for them. Thus, Korea need to collect $CO_2$ emission data not only the routes of container from port but also activities in the port. In this paper, an estimation of $CO_2$ emission under the route of container transportation at Korea by using O/D analysis will be addressed. And then, it will be used to make a optimal routes of container transportation which can reduce $CO_2$ emission in future.

• Journal of Korea Port Economic Association
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• v.22 no.3
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• pp.79-96
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• 2006

In this paper, using the gravity model, I examined that the port traffic in the port of Pusan have been influenced by GDP of South Korea, GDP of trading countries, an agreement on maritime transport, maritime transport charge and the local economic integration, etc. In view of the policy implication based on the result of analysis by the gravity model, the port traffic and the transshipment in the port of Pusan is positively influenced by GDP of South Korea, GDP of trading countries and countries on the way of main sea route(LINE). But it is negatively influenced by maritime transport charge. Especially, when a maritime transport charge goes up 1 percentage point, it is estimated that a transshipment decreases about 0.586-0.895 percentage point. So, a maritime transport charge was found to have more effect on a transshipment than a port traffic(except transshipment).

• Journal of the Korean Society of Marine Environment & Safety
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• v.27 no.6
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• pp.754-762
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• 2021

Students at Maritime University can expect to improve their understanding of the jobs they will perform in the future through long-term boarding in a one-year boarding practice that allows them to understand necessary work practices. Satisfaction with attending maritime college can also affect the job satisfaction and turnover intention of shipping industry workers after graduation. Therefore, by checking job satisfaction for each year of study, we intend to analyze and improve the curriculum or factors necessary for their future career choice. Based on previous studies, this study attempted to determine the effects of self-efficacy, teamwork, and self-leadership of maritime college students on job satisfaction through career planning, .analyze the factors that affect job satisfaction by year of study, and empirically confirm the factors students need in each year. The analysis, found that self-efficacy had the greatest influence on job satisfaction, and the effects of teamwork and self-leadership were similar in size.