• Advances in robotics research
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• v.2 no.3
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• pp.183-199
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• 2018

This paper presents the development of a 3D printed humanoid robotic hands of SignBot, which can perform Malaysian Sign Language (MSL). The study is considered as the first attempt to ease the means of communication between the general community and the hearing-impaired individuals in Malaysia. The signed motions performed by the developed robot in this work can be done by two hands. The designed system, unlike previously conducted work, includes a speech recognition system that can feasibly integrate with the controlling platform of the robot. Furthermore, the design of the system takes into account the grammar of the MSL which differs from that of Malay spoken language. This reduces the redundancy and makes the design more efficient and effective. The robot hands are built with detailed finger joints. Micro servo motors, controlled by Arduino Mega, are also loaded to actuate the relevant joints of selected alphabetical and numerical signs as well as phrases for emergency contexts from MSL. A database for the selected signs is developed wherein the sequential movements of the servo motor arrays are stored. The results showed that the system performed well as the selected signs can be understood by hearing-impaired individuals.

• Korean Journal of Optics and Photonics
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• v.30 no.2
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• pp.67-73
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• 2019

In this paper, we investigated the sensing ability of an extraordinary optical transmission sensor, which is based on the diverse configurations of highly ordered structures. The diverse nanostructures of subwavelength hole array were designed to have different periods and lattice configurations of the array. To verify the sensing ability of the sensor, we measured the transmittance spectra of samples (n = 1.333, 1.363) for diverse configurations of substrates. The measured transmittance spectra of diverse materials with different refractive indices show that the sensitivity increased as the period of the structures increased. Also, improved sensing performance of the sensor was achieved for the square array, compared to the hexagonal array.

• Journal of the Semiconductor & Display Technology
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• v.20 no.3
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• pp.140-145
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• 2021

This paper deals with the development of a deep-learning-based runway cleaning robot using an optical camera. A suitable model to realize real-time object detection was investigated, and the differences between the selected YOLOv3 and other deep learning models were analyzed. In order to check whether the proposed system is applicable to the actual runway, an experiment was conducted by making a prototype of the robot and a runway model. As a result, it was confirmed that the robot was well developed because the detection rate of FOD (Foreign Object Debris) and cracks was high, and the collection of foreign substances was carried out smoothly.

• Journal of the Korean Society for Heat Treatment
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• v.35 no.1
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• pp.20-26
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• 2022

This paper was designed to prevent intervertebral disc escape and treatment. we produced downsized lumbar traction bed at home and automated system depending on weight and muscle mass by using 3D print and Arduino to confirm the possibility of prototyping. Hence, we checked muscle mass 10 males in their 20s with different exercise conditions, and it shows that average muscle mass of group who exercised was 56.63kg, and non-exercise group was 50.8 kg. this is shows lumbar repetitive exercise can show the traction therapy effect can be seen traction therapy effect. In addition, we installed wooden doll substitute people with spring and test changing of length. Traction bed has the steps ranging from 1 to 4, in which the motor with torque and rpm, ranging from 4.7 to 5.5 kgf and from 4.5 to 5.3 rpm, respectively. The motor controlled with the voltage of Arduino was operated for the length of the spine to be stretched to 4-5 mm. As increasing the weight of the wooden doll by 10g, it was confirmed that the spring increased by 4-5 mm from the first step to the fourth step.

• Ocean Systems Engineering
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• v.12 no.4
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• pp.461-477
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• 2022

Dynamic Positioning (DP) is a system that uses computer-controlled thrusters, propellers, and other propulsion devices to automatically maintain a vessel's position and heading. In this study, a wind turbine installation vessel with DP capabilities was proposed for use in mild environmental conditions in the Yellow Sea. The thruster arrangements of the vessel were analyzed in relation to wind and current loads, and it was found that a four-corner arrangement of thrusters provided the best position-keeping performance. The vessel's DP control performance was also analyzed in relation to the increased environmental load caused by the presence of a wind turbine, using a capability plot. The vessel's performance was evaluated in three different states: floating with no load, during the loading of a wind turbine and suction buckets, and after the wind turbine has been installed. The use of 750 kW and 1,000 kW thrusters was also considered, and the environmental loads in the Saemangeum coastal area and the environmental load when a 5-Megawatt wind turbine is on board were assessed. The study concluded that at least four thrusters should be used for DP to safely manage the installation process of wind turbines.

• Journal of Sensor Science and Technology
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• v.30 no.6
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• pp.456-460
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• 2021

In this study, a Non-Dispersive Infrared (NDIR) Carbon Dioxide (CO₂) sensor with an externally exposed optical cavity is proposed for improving sensitivity. NDIR CO₂ sensors with high performance must use a lamp-type infrared (IR) source with a strong IR intensity. However, a lamp-type IR source generates high thermal energy that induces thermal noise, interfering with the accuracy of the CO₂ concentration measure. To solve this problem, the optical cavity of the NDIR CO₂ sensor is exposed to quickly dissipate heat. As a result, the proposed NDIR CO₂ sensor has a shorter warm-up time and a higher sensitivity compared to the conventional NDIR CO₂ sensor.

• Journal of Sensor Science and Technology
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• v.32 no.4
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• pp.207-212
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• 2023

H₂S is a toxic and harmful gas, even at concentrations as low as hundreds of parts per million; thus, developing an H₂S sensor with excellent performance in terms of high response, good selectivity, and fast response time is important. In this study, an H₂S sensor with a high response and fast response time, consisting of a sensing material (SnO₂), an electrode, a temperature sensor, and a micro-heater, was developed using micro-electro-mechanical system technology. The developed H₂S sensor with a micro-heater (circular type) has excellent H₂S detection performance at low H₂S concentrations (0-10 ppm), with quick response time (<16 s) and recovery time (<65 s). Therefore, we expect that the developed H₂S sensor will be considered a promising candidate for protecting workers and the general population and for responding to tightened regulations.

• Proceedings of the Korea Information Processing Society Conference
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• 2023.11a
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• pp.957-958
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• 2023

본 연구에서는 공정 내 인체 끼임 사고 및 저출산 고령화 시대 등의 문제들로 인한 인력 감소 문제들을 해결하기 위하여 인공지능 기반의 모빌리티 플랫폼을 개발하였다. 본 플랫폼은 yolo-v4 기반으로 로봇이 공정 내부를 이동하면서 공정 내 불량 와이어를 검출하여 공정 유지보수 관리자에게 알려 주고 실시간으로 공정 내부 상황을 무선으로 모니터링할 수 있는 기술을 연구하였다. 또한, 로봇에는 무선 충전 기능을 갖추고 있어 추가적인 공정 내 인체 끼임 사고 등을 예방할 수 있도록 하였다. 본 연구 결과에서는 불량 와이어 검출 시, 평균 92.1%의 정확도를 보였으며, 공정 제품에 대한 양품, 불량품의 검출은 평균 98%의 정확도를 보였다. 또한, 실시간 무선 영상 모니터링는 24fps로 전송되어 공정 내부를 살피는 것에 유의미한 결과를 보였다.

• Journal of the Korean Society for Precision Engineering
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• v.29 no.12
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• pp.1279-1284
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• 2012

Micro structures which are widely used at various fields are commonly fabricated by lithograph, etching and laser methods. Recently, with the emergence of micro tools and ultra-precision machine tools, fabrication of the micro structures obtained using end-milling are studied. However, there are some problems due to the diameter of the micro end-mill getting smaller below $100{\mu}m$. The micro run-out resulted from miniaturization of end-mills have influence seriously on accuracy of micro structures. The error of run-out with a tooling jig showed a decrease of about $9.3{\mu}m$. Furthermore, micro structures with width of $30{\mu}m$ could be applied through experiments of slot machining obtained using 30 and $50{\mu}m$ end-mill. Also, narrow angle structures with $30^{\circ}$ angle could be applied through analysis of machining acute angle structures. Based on basic experiments, micro fluidics channels and spiral patterns for air bearing were machined.

• 한국HCI학회:학술대회논문집
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• 2006.02a
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• pp.210-218
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• 2006

본 논문은 광주과학기술원(GIST)에서 개발하고 있는 전남지역 '운주사'의 천불천탑 설화를 근간으로 한 반응형 가상 문화 체험 시스템(Responsive Multimedia System for virtual storytelling)의 햅틱 변형 상호작용에 관한 것이다. 기존의 디지털 문화재 체험 시스템은 사실적인 체험을 제공하기 위해 시각 및 청각 기술 개발에 많은 연구 및 노력이 이루어져왔다. 그러나 최근 인간의 인지 체계의 중요 요소인 촉감 상호작용의 중요성이 증대 됨에 따라, 본 논문에서는 가상 문화재 체험을 위한 햅틱 변형 알고리즘 및 상호작용 시스템을 개발하여 가상 불상을 만져보고 그 표면을 변형시키게 함으로써 몰입감을 증대하고 재미를 주는 시스템을 제공하였다. 아울러 체험의 몰입감 증대를 위해 본 시스템은 시/청각과 더불어 청각 효과를 가미하여 체험 시 발생되는 주변 환경의 소리(새, 물, 바람소리)를 제공하고, 기존의 문화체험 시스템과의 차별성을 위해 3 차원 입력장치를 이용하여 체험자가 직접 가상 불상을 변형시키면서 체험자 고유의 작품을 만들어낼 수 있는 상호작용을 제공한다. 따라서 제안된 햅틱 변형 상호작용 시스템은 체험자의 능동적 참여 및 흥미 유발을 통하여 문화 유산에 대한 교육적 효과 및 관심 증대에 기여할 수 있을 것이라 여겨진다.