• Tribology and Lubricants
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• v.30 no.1
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• pp.52-58
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• 2014

Because food crops serve as the raw materials for biodiesel, the increasing use of biodiesel as an alternative fuel can lead to adverse effects such as food price inflation and may contribute to global starvation. To solve these problems, efforts are being made to explore various nonedible raw materials for producing biodiesel. Different raw materials impart different fuel characteristics to biodiesel. In this study, we synthesized pure fatty acid methyl ester (FAME), which is a biodiesel component, and then analyzed its fuel properties. The fuel properties of pure FAME would be useful in producing biodiesel from various new raw materials.

• Proceedings of The Korean Society of Agricultural and Forest Meteorology Conference
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• 2016.09a
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• pp.41-43
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• 2016

• Journal of Advanced Navigation Technology
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• v.20 no.4
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• pp.305-313
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• 2016

International Civil Aviation Organization (ICAO) has recommended the adoption of performance-based navigation (PBN), which utilizes global navigation satellite system (GNSS). As a part of efforts to adopt PBN in South Korea, preparations have been made to implement GNSS. In Oct. 2014, Korea augmentation satellite system (KASS) was officially launched for development. A set of navigation devices need to be on-board for an airplane to utilize GNSS. GNSS navigation devices are used for different phases of flights through en-route, terminal, departure, approach and a wide variety of specification standards have been proposed for GNSS navigation. In this paper, we investigate the many proposed standards for GNSS navigation devices and their interfaces. This paper can be useful for designing procedures and flight test used in KASS implementation.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.19 no.5
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• pp.1235-1242
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• 2015

In global shipping logistics, it is important for users to keep track of the location of their continuously moving cargos. Analyzing the GPS data stream coming from the tag which is attached to the cargo, we are able to keep track of the cargo location in terms of going into or out of a certain logistics area using the information of the spatial relationship change between the tag and the logistics area. In this paper, we propose a simulation system for measuring the precision and false alarm rate of the cargo location tracking algorithm which generates spatial events over the global logistics areas. Due to the difficulty of experiment with a real tag, we developed a tag emulator to create a virtual tag which operates exactly like a real tag. We show the cargo location tracking system works correctly with the tag emulator which communicates with it using the same protocol as the real tag.

• Asian Journal of Innovation and Policy
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• v.9 no.3
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• pp.281-307
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• 2020

A variety of approaches are being applied to improve the existing ex-ante evaluation by expert panels in publicly funded R&D. While the objective evaluation criteria are constantly being improved to screen and select the superior projects, alternative approaches such as random prioritization and logical modeling are also underway to overcome the conservative bias of reviewers and to secure disruptive innovation. This study intends to find critical implications for ex-ante evaluation of public R&D system from the comparison of Indonesia and Korea. For the comparative analysis, literature review and expert in-depth interviews are conducted on the national R&D system and the selection evaluation process. In Korea, the selection criteria of projects are legally promulgated for establishing an objective evaluation system, and at the program level, the major considerations in the planning process are specified by Presidential Decree. On the other hand, while Indonesia conducts R&D in 47 strategic fields largely by public research institutes (PRI) based on the non-competitive government contributions. This study draws out implications of institutionalizing the planning process at the level of program, and of increasing the ratio of contract-based competitive funding at the level of project in the national R&D portfolio.

• Journal of Electrochemical Science and Technology
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• v.13 no.4
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• pp.438-452
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• 2022

For cuboid and ellipsoid crystallites of LiFePO₄ powders, by X-ray diffraction (XRD) and microscopic (TEM) studies, it is possible to determine the anisotropic parameters of the crystallite size distribution functions. These parameters were used to describe the cathode rate capability within the model of averaging the diffusion coefficient D over the length of the crystallite columns along the [010] direction. A LiFePO₄ powder was chosen for testing the developed model, consisting of big cuboid and small ellipsoid crystallites (close to them). When analyzing the parts of big and small rate capabilities, the fitting values D = 2.1 and 0.3 nm²/s were obtained for cuboids and ellipsoids, respectively. When analyzing the results of cyclic voltammetry using the Randles-Sevcik equation and the total area of projections of electrode crystallites on their (010) plane, slightly different values were obtained, D = 0.9 ± 0.15 and 0.5 ± 0.15 nm²/s, respectively. We believe that these inconsistencies can be considered quite acceptable, since both methods of determining D have obvious sources of error. However, the developed method has a clearly lower systematic error due to the ability to actually take into account the shape and statistics of crystallites, and it is also useful for improving the accuracy of the Randles-Sevcik equation. It has also been demonstrated that the shape engineering of crystallites, among other tasks, can increase the cathode capacity by 15% by increasing their size correlation coefficients.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.10 no.5
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• pp.356-361
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• 2000

The radial position of OiSF-ring has been meaningful data in industry. Thus it's position was calculated by application of (V/G)/sub crit/ = 0.138 ㎟/minK and point defect dynamics for industrial scale grower with various pull rates. After the calculation, compared with experimental result. OiSF-ring diameters expected with calculation were good agreement with experimental results. In order to show validity of the predicted temperature distribution using STHAMAS which is one of the global simulator for Cz crystal growing, temperature was measured along the axis of crystal using thermocouples, and compared with the calculated temperature. We found the effective thermal conductivity K/sub m/ (r) which gives in accordance with the temperature distribution at the axis of crystal and crystal/melt interface shape between experimental and computational results. Therefore, effective thermal conductivity K/sub m/ (r) was applied instead of solving melt convection problem.

• Interaction and multiscale mechanics
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• v.4 no.1
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• pp.35-47
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• 2011

A global-local finite element modeling technique is employed in this paper to predict the fatigue life of radial truck tires. This paper assumes that a flaw exists inside the tire, in the local model. The local model uses an FEM fracture analysis in conjunction with a global-local technique in ABAQUS. A 3D finite element local model calculates the energy release rate at the belt edge. Using the analysis of the local model, a study of the energy release rate is performed in the crack region and used to determine the crack growth rate analysis. The result considers how different driving conditions contribute to the detrimental effects of belt separation in truck tire failure. The calculation of the total mileage on four sizes of radial truck tires has performed on the belt edge separation. The effect of the change of belt width design on the fatigue lifetime of tire belt separation is discussed.

• 한국전산유체공학회:학술대회논문집
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• 2003.10a
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• pp.224-224
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• 2003

• Food preservation and processing industry
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• v.14 no.2
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• pp.10-17
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• 2015