• Design & Manufacturing
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• v.12 no.2
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• pp.40-45
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• 2018

Recently, in construction equipment machinery production, development has focused on environmentally-friendly functions to improve existing production capacity. For excavators as well, emphasis has been placed on response to environmental regulations, miniaturization, and noise reduction, while technology is being developed considering cost reduction and safety.Accordingly, the front support, an inner reinforcement part of the excavator, as well as high-strength steel plates to improve safety and reduce weight, are being applied.However, in the case of high-strength materials, Springback occurs in the final formed part due to high residual stress during product forming. Derivation of a forming or product shaping process to reduce springback is needed. Accordingly, regarding the front support, an inner reinforcement part of the excavator, this study derived a method to improve springback and secure shape stiffness through analysis of the springback occurrence rate and springback causes through a forming analysis.As for the results of analyzing the springback occurrence rate of existing products through forming analysis, springback of -22.6 mm < z < 27.35 mm occurred on the z-axis, and it was confirmed that springback occurred due to the stiffness reinforcing bead of the upper and middle parts of the product.To control product residual stress and springback, we confirmed a tendency of springback reduction through local pre-cutting and stiffness reinforcement bead relocation.In the local pre-cutting model, springback was slightly reduced by 5.3% compared with the existing model, an insignificant reduction effect. In the stiffness reinforcement bead relocation model, when an X-shaped stiffness reinforcement bead was added to each corner portion of the product, springback was reduced by at least 80%.The X-shaped bead addition model was selected as the springback reduction model, and the level of stiffness compared to the existing model was confirmed through a structural analysis.The X-shaped bead additional model showed a stress springback of 90% and springback reduction of 7.4% compared with the existing model, indicating that springback and stiffness will be reinforced.

• The Journal of the Convergence on Culture Technology
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• v.6 no.4
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• pp.677-684
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• 2020

Our country is already in the aging corner and fall down is the elderly personal, social and economic problems are causing. therefore, executed this study for inquiring into an athletic effect for the balance ability increase that was a main variable of an fall down. The purpose of this study, to find the effect of balance training using visual feedback and somatosensory. Experimental group divided the three groups, objects measured balance ability of each experimental groups before experiment, the balance exercise group used visual feedback by Nintendo Wii(company - model), the balance exercise group used visual and TOGU, the balance exercise group used blind and TOGU. 4 experimental of each groups measured MFT and EMG value after training. having rest time, 4 experimental of each groups measured MFT and EMG value after training used balance pad. MFT - visual feedback with somatosensory training is most efficient but, indifferent both balance training with visual feedback and balance training with somatosensory. EMG - training with somatosensory is more efficient than training with visual feedback. Conclusion : in the process of improving equilibrium ability of patient who is lack of balance ability, somatosensory training is effective to correct different of left, right and frequency of left, right. visual feedback is the most effective way to improve dynamic balance sensory, so parallel of these two practice is thought to be the most effective.

• Journal of Digital Contents Society
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• v.4 no.2
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• pp.211-221
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• 2003

The objective of this paper is performance analysis of the digital document image decimation algorithm which generates a value of decimated element by an average of a target pixel value and a value of neighbor intelligible element to adaptively reflect the merits of ZOD method and FOD method on the decimated image. First, a target pixel located at the center of sliding window is selected, then the gradient amplitudes of its right neighbor pixel and its lower neighbor pixel are calculated using first order derivative operator respectively. Secondly, each gradient amplitude is divided by the summation result of two gradient amplitudes to generate each local intelligible weight. Next, a value of neighbor intelligible element is obtained by adding a value of the right neighbor pixel times its local intelligible weight to a value of the lower neighbor pixel times its intelligible weight. The decimated image can be acquired by applying the process repetitively to all pixels in input image which generates the value of decimated element by calculating the average of the target pixel value and the value of neighbor intelligible element. In this paper, the performance comparison of proposed method and conventional methods in terms of subjective performance and hardware complexity is analyzed and the preferable approach for developing the decimation algorithm of the digital document image on the basis of this analysis result has been reviewed.

• Journal of the HCI Society of Korea
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• v.13 no.3
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• pp.17-33
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• 2018

Humans process aesthetic functions of objects such as form, size, color, and texture through vision, while at the same time observe them with a symbolic function by a new psychological interpretation based on their past experience. Therefore, it is more important to study and understand the thoughts and psychological influences of how humans perceive with their eyes than what humans simply look with them. With this research purpose in the background, this study will demonstrate in detail the cognitive characteristics of analog and digital images as a symbolic function with a "formative" point of view. Five hypotheses were established, which were proven through the following tests: smartphone, most frequently used in our daily lives, is simplified to a two-dimensional line drawing form, which is set to instances where the R(radius) is applied to the horizontal line of the two-dimensional form of smartphone, where Run-in-R(radius) is applied, and R(radius) rounding is applied to the edges of those shapes. The shapes were combined to form 12 pairs, which was used in a test to the test subjects. As a result, some human characteristics were observed; in specific, some helped prove objectively how humans perceived analog and digital images as psychologically stronger as a symbolic function. If people's thoughts and feelings gained through such study could be stored in database as one value and be provided to product designers, I believe it could be developed into design form as a basic emotional design that consumers desire.

• Journal of the Institute of Convergence Signal Processing
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• v.10 no.4
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• pp.274-279
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• 2009

The flow of a universal system-level design methodology consists of system specification, system-level hardware/software partitioning, co-design, co-verification using virtual or physical prototype, and system integration. In this paper, verification environments based-on SystemVerilog and SystemC, one is native-code co-verification environment which makes prompt functional verification possible and another is SystemVerilog layered testbench which makes clock-level verification possible, are implemented. In native-code co-verification, HW and SW parts of SoC are respectively designed with SystemVerilog and SystemC after HW/SW partitioning using SystemC, then the functional interaction between HW and SW parts is carried out as one simulation process. SystemVerilog layered testbench is a verification environment including corner case test of DUT through the randomly generated test-vector. We adopt SystemC to design a component of verification environment which has multiple inheritance, and we combine SystemC design unit with the SystemVerilog layered testbench using SystemVerilog DPI and ModelSim macro. As multiple inheritance is useful for creating class types that combine the properties of two or more class types, the design of verification environment adopting SystemC in this paper can increase the code reusability.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.12 no.4
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• pp.425-433
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• 2019

In this paper, the RCS analysis of the 10m unmanned surface vehicles was performed, and the factors of RCS increase were analyzed. Modeling techniques by transforming a geometric shape can reduce the RCS area, which can be used to develop stealth unmanned surface vehicles. In order to reduce the RCS, the existing Top Mast part was moved 1m to the tail part, the 5 degree tilt angle was moved below 0.5 m, and additional guided walls were installed to minimize the influence on the center and surrounding corner reflecting structures. As a result of comparing and analyzing the RCS analysis value with the existing model, it can be seen that the reduced countermeasure model is -3.79 dB lower than the existing model for all elevations. In particular, it can be seen that the strong scattering phenomenon is substantially removed in the region except the sacrificial angle region. In addition, it can be seen that in the case of -5m to 2m where the guide wall is added, the reflected signal is improved up to 20 to 40 dB or more, so that it does not appear on the 2D ISAR image. RCS analysis of unmanned surface vehicles explained the process of analyzing and identifying problem location through distance profile analysis and ISAR image analysis.

• Journal of IKEEE
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• v.23 no.1
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• pp.193-199
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• 2019

In this study, we have proposed a floating metal guard ring structure based on TCAD simulation in order to enhance the breakdown voltage characteristics of gallium oxide ($Ga_2O_3$) vertical high voltage switching Schottky barrier diode. Unlike conventional guard ring structures, the floating metal guard rings do not require an ion implantation process. The locally enhanced high electric field at the anode corner was successfully suppressed by the metal guard rings, resulting in breakdown voltage enhancement. The number of guard rings and their width and spacing were varied for structural optimization during which the current-voltage characteristics and internal electric field and potential distributions were carefully investigated. For an n-type drift layer with a doping concentration of $5{\times}10^{16}cm^{-3}$ and a thickness of $5{\mu}m$, the optimum guard ring structure had 5 guard rings with an individual ring width of $1.5{\mu}m$ and a spacing of $0.2{\mu}m$ between rings. The breakdown voltage was increased from 940 V to 2000 V without degradation of on-resistance by employing the optimum guard ring structure. The proposed floating metal guard ring structure can improve the device performance without requiring an additional fabrication step.

• International conference on construction engineering and project management
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• 2022.06a
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• pp.1250-1251
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• 2022

Measuring management is an important part of preventing the collapse of retaining walls in advance by evaluating their stability with a variety of measuring instruments. The current work of measuring management requires considerable human and material resources since measurement companies need to install measuring instruments at various places on the retaining wall and visit the construction site to collect measurement data and evaluate the stability of the retaining wall. It was investigated that the applicability of the current work of measuring management is poor at small and medium-sized urban construction sites(excavation depth<10m) where measuring management is not essential. Therefore, the purpose of this study is to develop a laser sensor-based hardware to support the wall displacement measurements and their control software applicable to small and medium-sized urban construction sites. The 2D lidar sensor, which is more economical than a 3D laser scanner, is applied as element technology. Additionally, the hardware is mounted on the corner strut of the retaining wall, and it collects point cloud data of the retaining wall by rotating the 2D lidar sensor 360° through a servo motor. Point cloud data collected from the hardware can be transmitted through Wi-Fi to a displacement analysis device (notebook). The hardware control software is designed to control the 2D lidar sensor and servo motor in the displacement analysis device by remote access. The process of analyzing the displacement of a retaining wall using the developed hardware and software is as follows: the construction site manager uses the displacement analysis device to 1)collect the initial point cloud data, and after a certain period 2)comparative point cloud data is collected, and 3)the distance between the initial point and comparison point cloud data is calculated in order. As a result of performing an indoor experiment, the analyses show that a displacement of approximately 15 mm can be identified. In the future, the integrated system of the hardware designed here, and the displacement analysis software to be developed can be applied to small and medium-sized urban construction sites through several field experiments. Therefore, effective management of the displacement of the retaining wall is possible in comparison with the current measuring management work in terms of ease of installation, dismantlement, displacement measurement, and economic feasibility.

• Journal of the Korea Society of Computer and Information
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• v.29 no.9
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• pp.137-144
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• 2024

Digital advertising, both indoors and outdoors, is evolving from traditional 2D formats to more immersive 3D forms. 3D advertising involves creating 3D content and displaying it through large LED installations on two sides of a building's corner, or using 3D hologram projectors indoors. This study examines the production process of 3D hologram projectors used indoors and LED-based 3D content used outdoors, analyzing potential issues and considerations when creating 3D digital advertising content. The findings reveal that while indoor hologram projector content provides 3D effects, the low resolution of the devices makes it challenging to implement complex content. However, they are cost-effective and easy to operate. On the other hand, LED-based 3D advertising content, produced in high resolution, requires more time for content creation and incurs higher hardware installation costs. Despite this, it effectively represents complex content and maximizes visibility due to its enhanced 3D effects. In conclusion, it is crucial to create tailored content that matches the resolution of the display device to maximize 3D effects in advertising. Specifically, when producing 3D billboard-style outdoor advertising content, the structure of the building on which it will be installed must be carefully considered.