• Composites Research
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• v.27 no.6
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• pp.248-253
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• 2014

In this study, tapered double cantilever beam specimens are designed with the variable of angle to investigate the fracture property at the bonded surface of adjoint structure. These specimens are made with four kinds of models as the length of 200 mm and the slanted angles of bonded surfaces on specimens of $6^{\circ}$, $8^{\circ}$, $10^{\circ}$ and $12^{\circ}$. By investigating experiment and analysis result of these specimens, the maximum loads are happened at 120 N, 137 N, 154 N and 171 N respectively in cases of the specimens with slanted angles of $6^{\circ}$, $8^{\circ}$, $10^{\circ}$ and $12^{\circ}$. As the analysis result approach the experimental value, it is confirmed to have no much difference with the values of experiment and analysis. It is thought that the material property can be investigated effectively on shear behavior of the material composed of aluminum foam bonded with adhesive through simulation instead of experiment by applying this study method.

• Journal of Korean Society for Atmospheric Environment
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• v.25 no.4
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• pp.275-288
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• 2009

The Korean government strengthened the environmental polices to manage and enhance Metropolitan Area air quality, and also has enforced "Special Act on Seoul Metropolitan Air Quality Improvement (SASMAQI)" issued in Dec. 2004. Recently government expanded the Seoul Metropolitan Air Quality Management District (SMAQMD) to the outskirts satellite cities of Seoul area through the "Revised Law Draft of SASMAQI". The SMAQMD has been alloted the allowable emission loads to the local governments on the basis of the carrying $PM_{10}$ capacity. However, in order to establish the effective air quality control strategy for $PM_{10}$, it is necessary to understand the corresponding sources which have a potential to directly impact ambient $PM_{10}$ concentration. To deal with the situations, many receptor methodologies have been developed to identify the origins of pollutants and to determine the contributions of sources of interests. The objective of this study was to extensively identify $PM_{10}$ sources and to estimate their contributions at the metropolitan area. $PM_{10}$ samples were simultaneously collected at the 3 semi-industrialized local cities in the Seoul metropolitan area such as Hwasung-si, Paju-si, and Icheon-si sites from April 15 to May 31, 2007. The samples collected on the teflon membrane filter by one $PM_{10}$ cyclone sampler were analyzed for trace metals and soluble ions and samples on the quartz fiber filter by another sampler were analyzed for OC and EC. Source apportionment study was then performed by using a positive matrix factorization (PMF) receptor model. A total of 6 sources were identified and their contributions were estimated in each monitoring site. Contribution results on Hwasung, Paju, and Icheon sites were as follows: 33%, 27%, and 27% from soil source, 26%, 26%, and 21% from secondary aerosol source, 11%, 11%, and 12% from biomass burning, 12%, 6%, and 5% from sea salt, 7%, 15%, and 19% from industrial related source, and finally 11%, 15%, and 16% from mobile and oil complex source, respectively. This study provides information on the major sources affecting air quality in the receptor sites and thus it will help to manage the ambient air quality in the metropolitan area by establishing reasonable control strategies, especially for the anthropogenic emission sources.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.2
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• pp.610-619
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• 2016

Digital manufacturing (DM) technology helps engineers design products promptly and reliably at low production cost by simulating a manufacturing process and the material behavior of a product in use, based on three-dimensional digital modeling. The computing infrastructure for digital manufacturing, however, is usually expensive and, at present, the number of professional design engineers who can take advantage of this technology to a product design accurately is insufficient, particularly in small and medium manufacturing companies. Considering this, the Korea Institute of Science and Technology Information (KISTI) and H University is operating a DM track in the form of Industry-University-Research Institute collaboration to train high-performance-computing-based DM professionals. In this paper, a series of courses to train students to work directly into DM practice in industry after graduation is reported. The operating cases of the DM track for two years since 2013 are presented by focusing on the progress in establishment, lecture and practice contents, evaluation of students, and course quality improvement. Overall, the track management, curriculum management, learning achievement of students have been successful. By expediting more active participation of the students in the track and providing more internship and job offers in the participating companies in addition to collaborative capstone design projects, the track can be expanded by fostering a nationwide training network.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.9
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• pp.82-91
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• 2020

Recently, the research and development of weapon systems have expanded from ILS centered on acquisition costs to LCS, including operating maintenance costs. Regulations define the provision and formula of operating maintenance costs, but this does not consider the characteristics of the design and operation/maintenance of real weapon systems based on engineering calculations. Therefore, this study suggests a simulation design method to complement these areas and produce more accurate operating maintenance costs. The research procedures are as follows. First, the provision and formula of operating maintenance costs were defined to make the simulation results applicable. Second, a simulation model was developed by reviewing design considerations so that the simulation results reflect reality more accurately. The design considerations include the PBS of weapon systems, operation schedules, specifications for operation/maintenance/warehouse facilities, and basic cost information (personnel expense and spare part/equipment cost). This study is expected to be effective in calculating the operating maintenance costs more easily and accurately.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.9
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• pp.518-527
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• 2020

The establishment of a green remodeling strategy is focused on technology, so the necessity of establishing a customized strategy considering the field situation has emerged. This paper examined the technology strategy through sensitivity analysis as a methodology for guiding strategy. For a 90-square-meter detached house, nine models of the construction standards of pre-1980s, 1984, and 2010 in Seoul, Daejeon, and Busan were assessed using the optimization method that combines the energy plus engine and the ModeFrontier. Sensitivity analysis was performed, and the remodeling strategy priority was derived. For pre-1980 models, the strategy for enhancing the roof insulation performance had a significant priority. The SHGC values of the windows were found to have the next highest priority regardless of the region and the time of completion, showing that the performance standard, including the SHGC, needs to be expanded. The possibility of remodeling while maintaining the existing geometry was confirmed because the adjustment of the window wall ratio accompanying large-scale demolition works has low priority. The priorities of technology strategies in each case showed very different patterns, suggesting the possibility of establishing a remodeling strategy by a comprehensive evaluation along with economics and constructability analysis.

• Cartoon and Animation Studies
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• s.49
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• pp.1-23
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• 2017

3D animation production has had a pivotal position in current animation industry and the necessity of professional management tool for 3D animation production has claimed due to its sophisticated pipeline from advance of technology and global production partnership trend. Shotgun and Ftrack are providing the most appropriate management toolset for 3D animation management among the extant management tools and the efficiency of Shotgun & Ftrack is identified compared with the traditional document oriented management style. The biggest strength of production management using Shotgun is that all of the production staff can directly participate in the communication on the tools therefore they can share the information on Shotgun & Ftrack in real time without constraint of time and location. Moreover, all the process of the production and the history of the discussion on certain production issues are systematically accrue on the tool so that the production history can be easily tracked. Finally, the production management using tools contributes collecting and analysing the production information for the production management team in studios. However, Shotgun & Ftrack has metadata based retrieval method which cost huge amount of effort by human's manual annotation and it also has the limitation of accuracy. In addition, the fact that studios has to have technical professionals first in order to institute the tools into their studios is the actual difficulty of Korean studios when they want to use management tools for their project. Thus, this paper suggests adopting the content-based retrieval system on the tools and tools' expanded technical service for the studios as the solution of the identified issues.

• Korean Journal of Remote Sensing
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• v.33 no.5_3
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• pp.763-771
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• 2017

The purpose of this paper is to review the background and purpose of the special issue on Theory of Environment Geospatial Information and Its Applications in Korean Journal of Remote Sensing. The significance of the paper was also discussed. Environmental information refers to environment related information (literature, statistics, images, etc.) in a comprehensive manner. Such environmental information as a local change or issue of the environment is defined as environmental spatial information by developing in a spatial form. Remote sensing data is very useful as direct or indirect data including environmental spatial information on wide-area and local environment. Various applications will be possible not only in the environmental field through several improvements. For this purpose, first, refining and scientificization of technology to build environmental spatial information could be performed. Second, the application field can be expanded by developing the concept and contents of existing environmental spatial information. The third method is continuous increase of the application of existing environmental spatial information. In this paper, the direction of development was examined that reflects recent changes of environmental spatial information such as conversion of data formats and integration with ICT (Information and Communications Technologies). In particular, the basic technology for the construction of environmental spatial information was reviewed through various papers. Through the studies related to the above, utilization of domestic environmental spatial information would be diversified. Also, the development of environment policy and efficient management of environmental factors could be possible.

• Korean Journal of Food Science and Technology
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• v.41 no.3
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• pp.258-264
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• 2009

The principal objective of this study was to estimate the measurement uncertainty associated with determination of deoxynivalenol (DON), a mycotoxin generated by Fusarium strain, in food. In service of this goal, wheat as a food matrix was analyzed via high performance liquid chromatography-ultraviolet (HPLC-UV) detection using an immunoaffinity column for clean-up. The uncertainty sources in the measurement process were identified by sample weight, final volume, and sample concentration in extraction volume with components including standard stock solution, working standard solution, 5 standard solutions, calibration curve, matrix, and instrument. The expanded uncertainty for DON at a concentration of 300 ${\mu}g/kg$ was estimated as 71.62 ${\mu}g/kg$ using a coverage factor of two, which provides a confidence level of approximately 95%. The most influential component in the uncertainty sources was the recovery of the wheat matrix, followed by the calibration curve. These results indicate that all efforts may be directed toward reducing the uncertainties of the recovery of the wheat matrix and the calibration curve to obtain a reliable HPLC-UV method for DON analysis in wheat.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.28 no.6
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• pp.332-349
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• 2016

OLAFOAM is the powerful CFD code and is an expanded version of $OpenFOAM^{(R)}$, for wave mechanics simulation. The $OpenFOAM^{(R)}$ does provide many solvers to correspond to each object of the numerical calculation in a variety of fields. OLAFOAM's governing equation bases on VARANS (Volume-Averaged Reynolds-Averaged Navier-Stokes) equation, and the finite volume method is applied to numerical techniques. The program is coded in C++ and run on the Linux operating system. First of all, in this study, OLAFOAM was validated for 1) wave transformation inside porous structure under bore and regular wave conditions, 2) wave transformation by submerged breakwater under regular wave condition, and 3) regular wave transformation and resultant vertical velocity distribution under current by comparison with existing laboratory measurements. Hereafter, this study, which is almost no examination carried out until now, analyzed closely variation characteristics of water surface level, wave height, frequency spectrum, breaking waves, averaged velocity and turbulent kinetic energy around porous submerged breakwater in the wave and current coexisting field for the case of permeable or impermeable rear beach. It was revealed that the wave height fluctuation according to current direction(following or opposing) was closely related to the turbulent kinetic energy, and others.

• Journal of Educational Research in Mathematics
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• v.27 no.4
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• pp.833-855
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• 2017

This study aims to reinvestigate the reason for introducing radian as a new unit to express the size of angles, what is the meaning of radian measures to use arc lengths as angle measures, and why is the domain of trigonometric functions expanded to real numbers for expressing general angles. For this purpose, it was conducted historical, mathematical and applied mathematical analyzes in order to research at multidisciplinary analysis of the radian concept. As a result, the following were revealed. First, radian measure is intrinsic essence in angle measure. The radian is itself, and theoretical absolute unit. The radian makes trigonometric functions as real functions. Second, radians should be aware of invariance through covariance of ratios and proportions in concentric circles. The orthogonality between cosine and sine gives a crucial inevitability to the radian. It should be aware that radian is the simplest standards for measuring the length of arcs by the length of radius. It can find the connection with sexadecimal method using the division strategy. Third, I revealed the necessity by distinction between angle and angle measure. It needs justification for omission of radians and multiplication relationship strategy between arc and radius. The didactical suggestions derived by these can reveal the usefulness and value of the radian concept and can contribute to the substantive teaching of radian measure.