• Journal of the Korean Society for Railway
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• v.19 no.5
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• pp.656-662
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• 2016

Based on time dependent location data of mobile phone users, users' ODs were produced after tracing their travel route and inducing their origins and destinations. System considered average signalizing frequency, which means that the longer the travel length is the more frequent the signal is. This is a home-based OD and is limited to the Seoul Metropolitan area. The OD matrix from the mobile phone data which was aggregated to the cell and transformed to the 'Dong' area, was compared to the KTDB OD. The results can be analyzed and it was determined that they are highly correlated because individual coefficients are 0.98 and 0.85, the former between the OD of this study and the KTDB Si/Gun/Gu unit area OD and the latter between the OD of this study and the Dong unit area KTDB OD.

• Journal of Digital Convergence
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• v.13 no.9
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• pp.115-128
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• 2015

As generation of Web 2.0 comes in, enormous information of corporation from various platform are being produced. However, corporations should understand features of each platform and appropriate strategies in order to attract the public in the midst of such flood of information. Numerous studies have been conducted regarding SNS which has grown rapidly in recent but a study relating a specific medium is relatively in short. So this study analyzed how information of Instagram bulletin board is accepted in perspective of consumer in Korean and America, We examined the relationship between intention of acceptance and Word Of Mouth effect through meditating effect of information usefulness. To answer the research question, we conducted online survey with Korean and USA college students. The result showed that usefulness of the information was shown to the major intermediary variable between the information characteristics of bulletin board and the intention of acceptance intention and Word Of Mouth(WOM).

• Spatial Information Research
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• v.9 no.2
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• pp.227-238
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• 2001

As society progresses and becomes more complicated, improvements and demanded in the quality of life according to various interest groups. In relation to environment concerns, waste landfill sites in particular have been of concern. Conflicts involving treatment of such sites and decision making policies have been a point of contention between local governments, residents, and concerned organizations. To resolve these conflicts, this study developed the Multi-Criteria Spatial Decision Support System (MC-SDSS). The results of the case study revealed several conclusions; first, the approach used in this study can help to yield a better consensus for deciding upon waste landfill sites; next, by conducing sensitivity analysis, technical errors which can occur during the decision making process can be minimized; and finally, resistance from specific opposition groups can be effectively dealt with by using MC-SDSS.

• Journal of the Korea Convergence Society
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• v.10 no.4
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• pp.139-145
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• 2019

This paper investigated the strength and stiffness of composite truss unit structures. The model used is a core-filled model combining the Kagome model and the cube truss model. The material properties used for the analysis are 304 stainless steel with elastic modulus of 193 GPa and yield stress of 215 MPa. The theoretical equation is derived from the relative elasticity relation of Gibson - Ashby ratio, the analysis was performed using Deform 3D, a commercial tool. In conclusion, the relative elasticity for this unit model correlates with 1.25 times the relative density and constant coefficient, elasticity is inversely proportional to pore size. The relative compressive strength has a correlation with relative density of 1.25 times. Proof of this is a real experiment, the derived theoretical relationship should further consider mechanical behavior such as bending and buckling. In the future, it is hoped that the research on the elasticity and the stress according to the structure of the three-dimensional space will be continued.

• Journal of Sensor Science and Technology
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• v.30 no.6
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• pp.388-394
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• 2021

The conventional microelectromechanical system (MEMS) process has been used to fabricate sensors with high costs and high-volume productions. Emerging 3D printing can utilize various materials and quickly fabricate a product using low-cost equipment rather than traditional manufacturing processes. 3D printing also can produce the sensor using various materials and design its sensing structure with freely optimized shapes. Hence, 3D printing is expected to be a new technology that can produce sensors on-site and respond to on-demand demand by combining it with open platform technology. Therefore, this paper reviews three standard 3D printing technologies, such as Fused Deposition Modeling (FDM), Direct Ink Writing (DIW), and Digital Light Processing (DLP), which can apply to the sensor fabrication process. The review focuses on strain/load sensors having both sensing material features and structural features as well. NCPC (Nano Carbon Piezoresistive Composite) is also introduced as a promising 3D material due to its favorable sensing characteristics.

• Journal of Appropriate Technology
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• v.6 no.2
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• pp.146-150
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• 2020

Assistive technologies for people with disabilities are often marginalized in the Fourth Industrial Revolution. In this paper, we intend to present the possibility of acquiring tactile information through the tactile display adapting an electromagnetic actuator. The multi-layered display designed for tactile communication has innovatively narrowed the size and spacing of cells in order to express pictures, maps, and graphics. This display has enabled the visually impaired to touch two-dimensional information combining with other assistive technologies so that. It would also provide a technical source of access to STEM education (Science, Technology, Engineering, and Mathematics) so that students will perform better and be better prepared for advanced education. Moreover, it can be applied to public infrastructure and transportation in smart-city projects on the globe. Hence, this paper introduces the principle of Electromagnetic-actuator and how it can be utilized in many diverse areas.

• Cartoon and Animation Studies
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• s.40
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• pp.139-155
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• 2015

Animation is completed in accordance with the original planning of visual direction in the process of post-production. Especially, a variety of visualization skills to meet the planning idea are directed in editing and compositing processes such as rendering and shading in the production of 3D animation. Therefore, the studies how to implement these visual effects have been conducted since the emergence of the animation. The rendering method which appears in the recent animations so often is the effect of 2D animation style although it is applied by 3D technique. 3D animation can be classified as two types including photo realistic and non-photo realistic renderings. The former is to render the images realistically while the latter is to highlight the formative effect with analogue style free from the realism of the photographs. Visual effect of 2D animation is non-realistic, that is, non-photo realistic rendering. The animations produced by this method have the depth of 3D animation expression in terms of space and animating, and can direct the viewer-friendly analogue style visuals, which are widely used as a post-production effect. Hence in this study, we selected a short animation, 'Paperman,' one of Disney's animations, produced by cartoon rendering method which belongs to the class of non-photo rendering technique in 3D graphics, as our subject. We analyzed their techniques and visual effects of the scenes expressed by cartoon rendering method so as to understand whether they meet the original direction idea with the composition work. In addition, we expect further developments of post-production methods, exceeding the limit of graphic expression in alignment with the trend that has become more various in the types and genres of non-photo rendering.

• Journal of the Institute of Electronics and Information Engineers
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• v.51 no.10
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• pp.96-106
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• 2014

Previous academic research on FPGA tools has relied on simple imaginary models for the targeting architecture. As the first step to overcome such restriction, the issues on analytic placement and legalization which are applied to commercial FPGAs have been brought up, and several techniques to remedy them are presented, and evaluated. First of all, the center of gravity of the placed cells may be far displaced from the center of the chip during analytic placement. A function is proposed to be added to the objective function for minimizing this displacement. And then, the density map is expanded into multiple layers to accurately calculate the density distribution for each of the cell types. Early fixation is also proposed for the memory blocks which can be placed at limited sites in small numbers. Since two flip-flops share control pins in a slice, a compatibility constraint is introduced during legalization. Pre-packing compatible flip-flops is proposed as a proactive step. The proposed techniques are implemented on the K-FPGA fabric evaluation framework in which commercial architectures can be precisely modeled, and modified for enhancement, and validated on twelve industrial strength examples. The placement results show that the proposed techniques have reduced the wire length by 22%, and the slice usage by 5% on average. This research is expected to be a development basis of the optimization CAD tools for new as well as the state-of-the-art FPGA architectures.

• Economic and Environmental Geology
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• v.45 no.6
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• pp.661-672
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• 2012

Lab scale experiments to investigate the dissolution reaction among supercritical $CO_2$-sandstone-groundwater by using sandstones from Gyeongsang basin were performed. High pressurized cell system (100 bar and $50^{\circ}C$) was designed to create supercritical $CO_2$ in the cell, simulating the sub-surface $CO_2$ storage site. The first-order dissolution coefficient ($k_d$) of the sandstone was calculated by measuring the change of the weight of thin section or the concentration of ions dissolved in groundwater at the reaction time intervals. For 30 days of the supercritical $CO_2$-sandstone-groundwater reaction, physical properties of sandstone cores in Gyeongsang basin were measured to investigate the effect of supercritical $CO_2$ on the sandstone. The weight change of sandstone cores was also measured to calculate the dissolution coefficient and the dissolution time of 1 g per unit area (1 $cm^2$) of each sandstone was quantitatively predicted. For the experiment using thin sections, mass of $Ca^{2+}$ and $Na^+$ dissolved in groundwater increased, suggesting that plagioclase and calcite of the sandstone would be significantly dissolved when it contacts with supercritical $CO_2$ and groundwater at $CO_2$ sequestration sites. 0.66% of the original thin sec-tion mass for the sandstone were dissolved after 30 days reaction. The average porosity for C sandstones was 8.183% and it increased to 8.789% after 30 days of the reaction. The average dry density, seismic velocity, and 1-D compression strength of sandstones decreased and these results were dependent on the porosity increase by the dissolution during the reaction. By using the first-order dissolution coefficient, the average time to dissolve 1 g of B and C sandstones per unit area (1 $cm^2$) was calculated as 1,532 years and 329 years, respectively. From results, it was investigated that the physical property change of sandstones at Gyeongsang basin would rapidly occur when the supercritical $CO_2$ was injected into $CO_2$ sequestration sites.

• Journal of Bio-Environment Control
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• v.4 no.1
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• pp.50-58
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• 1995

These studies were carried out to develop a system for non -destructive and continuous measurement of fresh weight and to analyse the growth response of leaf lettuce under the different nutrient solution and light condition with this system. The developed measurement system was consisted of four load cells and a microcomputer. The output from the system was highly positive correlation with the plant fresh weight above the surface of the hydroponic solution. The top fresh weight of plant could be measured within the error $\pm$ 1.0g in the range of 0 - 2000g. The top fresh weight of leaf lettuce increased 44 times at 18th day after transferring to the nutrient solution, and the maximum growth rate was observed at 13th day after transferring. The growth rate was 10.7- 29.6% per day during 18 days. Optimum concentration of the nutrient solution for the growth of lettuce was 1.4 - 2.2 mS/cm of EC level. When the light condition was changed from dark to light, the fresh weight was temporarily decreased, but the fresh weight increased under the opposite condition. Top fresh weight of leaf lettuce in the darkness normally increased within 12 hours after darkness treatment, and then slowly increased until 78 hours under continuous dark condition. After that times, the fresh weight began to decrease.