• The Research Journal of the Costume Culture
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• v.32 no.3
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• pp.438-451
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• 2024

The interlacing technique has a long history of use as a means of creative expression and persists in modern society to satisfy the individual pursuit of pastimes. This method has the developmental potential to create new trends in the future. Interlacing techniques (e.g., basketry, plaiting, braiding, and knotting) are closely related to plastic arts fields, architecture, art, and industrial design where the various interlacing practices are applied. This research uses case analysis to study the types of expression found in the formative art field wherein the interlacing technique is applied. Results reveal several expressions, including optical illusion visual type, relief surface type, porous perspective type, and object borrowing type, all of which appeared in fashion bags. The aesthetic formativeness, which appeared in the fashion bags that applied interlacing techniques, was then classified according to geometric formative beauty in a process based on rules and order. Nature-friendly formative beauty reflecting handicraft locality and omnidirectional formative beauty by disordered deconstruction and heterogeneous combination were determined. The use of interlacing techniques that show creative, unique combinations and variations is expected to inspire the development and application of bag design that suits individual and original modern fashion trends. One limitation of this thesis is that it only studied cases appearing in modern fashion bags.

• Journal of the Korean Society of Industry Convergence
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• v.27 no.4_2
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• pp.825-832
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• 2024

Traditional cars have a structure that steers the front wheels to change their direction so they have difficulties in performing parking motion, especially in a narrow space. As electric vehicles developed, robotics technology especially omni-directional mobile robot technology began to be incorporated into the automobile field. Omni-directional mobility and special turning movements are particularly useful for parking cars. In this paper, we propose a four-wheeled mobile robot. The proposed robot has a structure that can combine or separate robot body and robot wheel parts by using electric brakes. The proposed robot has omni-directional mobility and has the ability to rotate around an arbitrary point. Due to these omnidirectional and rotational characteristics, the proposed robot allows for various types of movements when applied to a car. In particular, parking is performed in a simple and intuitive manner that does not require complicated path planning. We implemented the proposed four-wheeled robot and showed its effectiveness by conducting several parking experiments.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.36 no.3
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• pp.289-295
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• 2012

In recent years, an increased amount of research has been carried out on mobile robots to improve the performance of service robots. Mobile robots maximize the mobility of service robots, thus allowing them to work in different areas. However, conventional service robots have their center of mass placed high above the ground, which may cause them to fall when moving at high speed. Furthermore, hub-type actuators, which are often used for mobile robots, are large and expensive. In this study, we propose a mobile robot with a hub-type actuator unit and a variable footprint mechanism. The proposed variable footprint mechanism greatly improves the stability and mobility of the robot, allowing it to move freely in a narrow space and carry out various tasks. The performance of the proposed robot is verified experimentally.

• The Journal of the Acoustical Society of Korea
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• v.10 no.2
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• pp.52-60
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• 1991

Sound propagation in a sloping sea bed ocean environment demonstrates ray curvature in a direction parallel to the shoreline. The theoretical analysis of this shows that an ensonified region and a shadow region are formed, and their spatial extents depend on the spatial coordinates of source and receiver, a sloping angle and sourece frequency. The purpose of this experimental study using a sloping sea bed model is to check the theoretical prediction as a part of an ongoing investigation in the ocean environment. The sloping sea bed model used in this experiment had an ideal pressure-release boundaries and a sloping angle of $220.5{\circ}$ A single frequency signal and an impulsive signal were used as omnidirectional point sources. The spatial acoustic field characteristics in the across slope direction were measured using the former and the frequency dependent field characteristics in a specific point were obtained using the latter. It has been found that the analysis for the spatial extent of shadow zone and the frequency dependent field characteristics in the across slope direction, has a good agreement with the theoretical solution.

• Journal of Advanced Navigation Technology
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• v.24 no.3
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• pp.232-237
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• 2020

In this paper, a compact microstrip-fed dual-band planar antenna for global positioning system (GPS) and mobile handset applications is presented. Dual operating frequency bands are achieved by an open end L-shaped slot and a bent rectangular slot. The proposed antenna is designed and fabricated on the FR4 substrate with dielectric constant of 4.3, thickness of 1.6 mm and size of 57 × 57 ㎟. The measured impedance bandwidth (|S₁₁|≤ -10dB) of the fabricated antenna is 60 MHz(1550 ~ 1610 MHz) in the GPS band and 670 MHz (1690 ~ 2360 MHz) in the DCS / IMT-2000 band, covering the required bandwidths for GPS(1570 ~ 1580 MHz) and DCS / IMT-2000 (1710 ~ 2200 MHz) bands. In particular, it has been observed that antenna has a good omnidirectional radiation patterns as well as high gain of 2.36 dBi and its efficiency is more than 90 % over the entire frequency band of interest.

• Journal of Advanced Navigation Technology
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• v.21 no.4
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• pp.353-358
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• 2017

In order to reduce the size of the previous stepped slot antenna for UWB applications(3.1 ~ 10.6 GHz) to half, an open ended stepped slot antenna is proposed. The proposed antenna consists of a stepped slot etched on the ground plane as radiation part and a microstrip feed-line with rectangular patch on the top plane for wideband impedance matching. The proposed antenna is designed and fabricated on the FR4 substrate with dielectric constant of 4.3, thickness of 1.6 mm and size of $28.5{\times}32mm^2$. The measured impedance bandwidth (${\mid}S_{11}{\mid}{\leq}-10dB$) of the fabricated antenna is 7.99 GHz(3.01~11 GHz) which is sufficient to cover UWB band (3.1 ~ 10.6 GHz). In particular, it has been observed that antenna has a good omnidirectional radiation patterns and high gain over the entire frequency band of interest even though the size of the proposed antenna is reduced to half when compared with the previous antenna.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.21 no.6
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• pp.698-705
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• 2010

A vehicle antenna for AM, FM, TDMB, GPS systems was designed and implemented. Omnidirectional AM antenna was designed by ferrite turn style antenna. For the FM and TDMB antenna, folded monopole antenna which helical is folded was applied. GPS antenna for the bandwidth achievement was designed by trapezoidal microstrip patch that has air substrate. Receiving signal strengths by the measurement were presented for the AM, FM and TDMB antenna. AM signal strength was -65.7 dBm, this strength is almost as same conventional pole antenna as -63.4 dBm. It can be replaced conventional pole or glass antenna by the studied antenna. Signal strengths for FM and TDMB were -55.66 and -43.50 dBm at center frequency, they are 5~10 dB higher than conventional antenna. Measurements of bandwidth and gain for the GPS antenna showed 135 MHz under VSWR 2 : 1 and 4.31 dBi, gains over GPS band were 3~5 dB higher than ceramic patch antenna.

• The Journal of the Korea institute of electronic communication sciences
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• v.10 no.9
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• pp.987-992
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• 2015

In this paper, neutralization line structure have been employed to improve the isolation between the MIMO antenna system. The proposed MIMO antenna size is $116mm{\times}64mm{\times}5mm$ and designed on FR-4(${\varepsilon}r=4.4$) ground substrate. Neutralization line was applied to enhance isolation between the each antenna elements. The fabricated antenna satisfied a VSWR below 3 in LTE band B13 and the isolation between the MIMO antenna system is presented below -15dB. On the H-plane, antenna shows an omnidirectional pattern. In LTE band B13, the antenna presents a gain of a -2.6dBi ~-1.18dBi and radiation efficiency of 33.49% ~ 46.45%. Comparing measurement result with the outcome of simulation, the proposed MIMO antenna is expected to be applied for mobile application.

• Journal of Broadcast Engineering
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• v.22 no.6
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• pp.850-853
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• 2017

In this paper, we propose an image analysis system based on omnidirectional image and object tracking image display using super wide angle camera. In order to generate spherical images, the projection process of converting from two wide-angle images to the equirectangular panoramic image was performed and the spherical image was expressed by converting rectangular to spherical coordinate system. Object tracking was performed by selecting the desired object initially, and KCF(Kernelized Correlation Filter) algorithm was used so that robust object tracking can be performed even when the object's shape is changed. In the initial dialog, the file and mode are selected, and then the result is displayed in the new dialog. If the object tracking mode is selected, the ROI is set by dragging the desired area in the new window.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.24 no.2
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• pp.123-130
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• 2014

An ultrasonic magnetostrictive transducer-based phased-array system for imaging defects in plate structures is newly proposed. In that most ultrasonic phased array systems rely on piezoelectric transducers or electromagnetic acoustic transducers, this system has its own unique feature of employing magnetostrictive transducers. Interest in using a phased array system using magnetostrictive transducers has been recently reported for pipe inspection but no such system has been developed for plate inspection. In this investigation, we aim to propose a phased array system using OL-MPTs (Omnidirectional Lamb wave Magnetostrictive Patch Transducers) for plate inspection. The developed system consists of a multi-channel function generator, power amplifiers, preamplifiers and a data acquisition unit. In the process of its development, each of the units must be checked and in doing so, we suggest types of ultrasonic wave experiments that should be carried out. Finally, the phased system using a transducer array composed of eight OL-MPTs is newly configured and is applied for actual crack detection experiments.