• Korea Trade Review
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• v.42 no.6
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• pp.131-154
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• 2017

In international trade, transportation generally has the largest and direct impact on freight costs. However, it is also sensitive to external factors such as global economic conditions, global trade volume and exchange rate. Therefore, it is necessary to examine the relationship and influence of international trade in terms of external factors that affect the change of imports and exports by marine and air transportation through empirical analysis. In particular, the analysis of the impact of these external factors on marine and air transportation is an important topic when recent exchange rate changes are significant, and it is also necessary to analyze what transportation means are more sensitive to exchange rate changes. In this study, we use the Vector Error Correction Model to analyze the dynamic effects of changes in exchange rate and domestic and international economic conditions on marine and air transportation from January 2000 to March 2017. Respectively. Alos, Impulse response function and variance decomposition were examined.

• Journal of Korean Academy of Nursing Administration
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• v.16 no.3
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• pp.295-305
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• 2010

Purpose: This study was conducted to evaluate the economic efficiency of a community-based nursing care center to help policy makers determine whether or not to invest in similar facilities. Methods: The subjects were 101 elderly people over 65 years who participated in a health management program from February 1 to July 31, 2007. Direct cost was estimated with center operations cost, medical cost for out-patients and pharmacy cost. Indirect cost was measured by transportation cost. Direct benefit was calculated by saved medical cost for out-patients, saved pharmacy cost, saved transportation cost, and reducing hospital charges. Indirect benefit was estimated with prevention of severe complications. Economic efficiency was evaluated by cost-benefit ratio and net benefit. Results: Operating a community-based nursing care center was found to be cost-effective. Specifically, the cost of operating the center evaluated here was estimated at 135 million won while the benefit was estimated at 187 million won. Benefit-cost ratio was 1.38. Conclusion: The Community-based nursing care center that was described here could be a useful health care delivery system for reducing medical expenditures.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.34 no.3
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• pp.999-1006
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• 2014

$CO_2$ emission factor for earthwork equipment was made based on fuel consumption quantity using IPCC carbon emission factor. This is presented through the carbon emission estimating guideline each facilities by the Ministry of Land, Infrastructure and Transportation in 2011. However, this method has the defect which don't apply the various condition of site. Therefor it needs the new emission factor supplemented these defects. This study will tries to estimate $CO_2$ emission with the direct measurement method using concentration flow velocity measurement (C-FVM) for earth work equipment and present the new $CO_2$ emission factor for earth work equipment after compare with emission factor of the Ministry of Land, Infrastructure and Transportation.

• Journal of the Korean Geotechnical Society
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• v.24 no.1
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• pp.5-13
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• 2008

The coefficient of permeability for a soil can be determined by the direct or the indirect method. The direct method of permeability can be performed either in the laboratory or in the field. The indirect method can be predicted from the soil-water characteristic curve. In this study, the coefficient of permeability for an unsaturated soil was determined by the modified apparatus of steady-state method (Klute, 1972) and was predicted from the equations of Brooks & Corey (1964) and van Genuchten (1980). The experimental results were compared with predicted coefficient of permeability and the applicability of the two equations (from Brooks & Corey, van Genuchten) was reviewed.

• Journal of Korean Society of Transportation
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• v.7 no.1
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• pp.19-34
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• 1989

In general, Shopping centers are located in the center of transportation, which induce more traffic concentration than other facilities. As a result, it becomes to one of the aggravating factors of urban ＆ transportation problem such as traffic conjestion, parking problems. Thus, in planning shopping-center, it is desirable that consumer\`s trip pattern is should lie more carefully analyzed in order to alleviate the above problems. This study is aimed at finding the characteristics of shopping tripes and analyzing the choice behavior of shopping center and mode-to-shop. This study has developed a nested logit model in which consumers choose shopping center and mode-to-shop with a sequential structure. The model was estimated using household data from the 1989 May, Seoul metropolitan area and the 18 alternatives of shopping center and 5 mode alternatives. The estimated model have been evaluated and it may be concluded that this model for shopping trips is effective and fesible. The conclusion of this study are as fellows. 1. Out-of-vehicle travel time is more important factor affecting behavior of mode choice than in-vehicle travel time. 2. All of direct-elasticities for mode with respect to the travel time is more elastic than travel cost. 3. Accessibility to shop is more important factor affecting the choice of shopping center than parking space. 4. The value of out-of-vehicle travel time exceeds the value of in-vesicle travel time by 1.64 times.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.23 no.1
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• pp.27-30
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• 2013

Catalyst-free graphene nano-sheets without substrates have been synthesized using fullerene and a high direct current (dc) pulse in the spark plasma sintering (SPS) process. Graphene nano-sheets were synthesized directly in the gas phase of carbon atoms which are generated from fullerene at a temperature of $600^{\circ}C$. Characterization has been carried out by scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HR-TEM), Raman spectroscopy (Raman), X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD).

• Journal of Welding and Joining
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• v.34 no.3
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• pp.31-39
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• 2016

The joining technology of the metal and engineering plastic is rising lately as the important issue in concerning with the method of reducing the weight and air pollution of the transportation structure such as automotive and vehicles. The metal/ plastic joining technology has been developed in 2 types of adhesively bonding and direct joining without adhesives. Moreover, in the direct joining method, there are 2 kinds of mechanical joining and welding. This review paper presents the present world wide status and tendency of the development of metal/plastic joining technology. This article intends to offer the materials for development and raising of the domestic metal/plastic joining technology.

• Membrane Journal
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• v.14 no.1
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• pp.53-56
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• 2004

Direct Methanol Fuel Cell (DMFC) is considered as a candidate technology for applications in stationary, transportation as well as electronic power generation purposes. To develop a high performance direct methanol fuel cell(DMFC), a competent electrolyte membrane is needed. The electrolyte membrane should be durable and methanol crossover must be low. One of the approaches to increase the stability of generally used polymer electrolyte membranes such as Nafion against swelling or thermal degradation is to bond it with an inorganic material physically or chemically. In Noritake Company, we have developed a novel method of reinforcing the polymer electrolyte matrix with inorganic fibers. Methanol crossover values measured were significantly lower than the original polymer electrolyte membranes. These fiber reinforced electrolyte membranes (FREM) were used for DMFC study and stable power output values as high 160 mW/$\textrm{cm}^2$ were measured. The details of the characteristics of the membranes as well as I-V data of fuel cell stacks are detailed in the paper.

• Journal of Institute of Convergence Technology
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• v.13 no.1
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• pp.13-17
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• 2023

Direct air capture (DAC) refers to the process of permanently removing CO₂ from the atmosphere by capturing CO₂ that has been emitted into the atmosphere from the past to the present directly from the atmosphere. DAC is a process that captures CO₂ that exists at 400 ppm in the atmosphere, so it has the problem of requiring a significant amount of air and high energy compared to CO₂ capture from a point source such as exhaust gas from a coal-fired power plant. In this study, we aim to introduce the performance, characteristics, and processes of absorbents that can be applied to DAC, focusing on the DAC process using absorbents developed to date, and present challenges that must be overcome in future DAC technology development.

• The Korean Journal of Emergency Medical Services
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• v.23 no.1
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• pp.87-99
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• 2019

Purpose: The aim of this study was conducted to assess the proficiency of both direct laryngoscopy and video laryngoscopy and the usefulness of each laryngoscope, thereby provide basic data for further education using video laryngoscopy. Methods: Forty one paramedic subjects participated in this study. Usability was measured with the System usability scale. The Macintosh direct laryngoscope and $C-MAC^{(R)}$ video laryngoscope were two instruments evaluated in the study. Results: Training with video laryngoscopy showed significantly better results within the categories of dental injury (p=.004), esophageal intubation (p=.001), and proper depth placement of intubation tubes (p=.019). The results of the System usability scale questionnaire and the degrees of visibility based on the Cormack & Lehane classification were also found to be better achieved with the video laryngoscopy (p=.000). Conclusion: This study suggests enhancing education with video laryngoscopy, which could reduce the risk of complications and duration of intubation while increasing the success rate among students and emergency medical technicians with little experience, rather than the existing method of only using direct laryngoscope, which requires considerable experience and skills.