• Proceedings of the KIEE Conference
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• 2008.07a
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• pp.1519-1520
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• 2008

이 논문에서는 이동로봇의 경로추적문제를 다항 퍼지 모델로 나타내고 SOSTOOL을 이용하여 해결하고자 한다. 제안하는 방법은 기존의 LMI을 사용한 방법과 비교하여 작은 제어입력과 이동로봇이 주어진 경로를 쫓아감에 있어 매끄러운 결과를 나타냄을 알 수 있다. 본 논문에서는 이동로봇 기구학을 시스템의 안정성 문제로 변형하고 이를 퍼지모델로 구성하여 SOSTOOL을 사용하여 제어입력을 구하고 모의실험을 통해 그 결과를 검증하도록 한다.

• Proceedings of KOSOMES biannual meeting
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• 2017.11a
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• pp.90-90
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• 2017

• Proceedings of the Korea Information Processing Society Conference
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• 2018.10a
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• pp.1018-1019
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• 2018

본 논문에서는 오픈 하드웨어 플랫폼인 라즈베리파이를 활용하여 IoT 디바이스-클라우드 간 발생 가능한 상호운용성 문제를 해결할 수 있는 EdgeX Open Framework 기반 IoT Edge Gateway 개발 과정을 기술하고 이를 검증하였다.

• Proceedings of the KIPE Conference
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• 2020.08a
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• pp.318-319
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• 2020

본 논문에서는 직류 시스템에 적용된 퓨즈를 수 ms 내에 용단시키기 위해 대전류를 주입하여 퓨즈의 I²t에 빠르게 도달시키는 방법을 제시한다. 대전류 주입을 목적으로 상시 충전된 커패시터를 퓨즈에 병렬 연결하여 과전류가 감지되면 방전시킨다. 커패시터에서 방전된 퓨즈에 흐르는 대전류는 I²t에 빠르게 도달시켜 수 ms내에 퓨즈를 용단시킨다. 제안하는 보호회로를 제작하고, 실험을 통해 성능을 검증하였다.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2022.06a
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• pp.408-409
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• 2022

슬릿을 통한 표면파 통신 가능성을 시험 검증하고 이를 통한 선박 밀폐구역에서의 선박 IoT 무선통신 시스템 구현 방안을 고찰하기 위해 선박 밀폐구역에서의 표면파 통신 환경을 구현하였고, 슬릿의 크기, 모양, 재질 변화 조건에 따라 표면파 통신 가능 여부와 전송속도 변화를 확인하였다.

• Journal of Internet of Things and Convergence
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• v.7 no.1
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• pp.1-7
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• 2021

The IoT market continues to expand and grow, but the security threat to IoT devices is also increasing. However, it is difficult to apply the security technology applied to the existing system to IoT devices that have a problem of resource limitation. Therefore, in this paper, we present a service that can improve the security of IoT devices by presenting authentication and lightweight cryptographic algorithms that can reduce the overhead of applying security features, taking into account the nature of resource limitations of IoT devices. We want to apply these service to home network IoT equipment to provide security. The authentication and lightweight cryptographic algorithm application protocols presented in this paper have secured the safety of the service through the use of LEA encryption algorithms and secret key generation by users, IoT devices and server in the IoT environment. Although there is no difference in speed from randomly generating secret keys in experiments, we verify that the problem of resource limitation of IoT devices can be solved by additionally not applying logic for secret key sharing to IoT devices.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.15 no.4
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• pp.649-659
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• 2002

For a variety of elastic-plastic stress fields of plane strain specimens, many research works verified the validity of J-T approach. To generalize the validity of J-T method, however, further investigations are needed for more practical 3D structures than the idealized geometries as plane strain specimens. In this work, selecting two main types of structures such as plate and straight pipe, we perform 3D finite element(FE) modeling, and accompanying elastic, elastic-plastic FE analyses. We then study the validity of J-T application to 3D structures, and present some useful informations for the design or assessment of pipe welds by comparing the stress fields from the detailed 3D FE analyses to those predicted with J-T two parameters.

• Journal of the Korean Institute of Intelligent Systems
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• v.27 no.1
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• pp.59-64
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• 2017

In this paper, a controller for discrete Takagi-Sugeno(T-S) fuzzy model under imperfect premise matching is proposed. Most of previous papers have obtained the stabilization condition using common quadratic Lyapunov function. However, the stabilization condition may be conservative due to the typical disadvantage of the common quadratic Lyapunov function. Hence, in order to solve this problem, we propose the stabilization condition of discrete T-S fuzzy model using fuzzy Lyapunov function. Finally, the proposed approach is verified by the simulation experiments.

• Korean Journal of Remote Sensing
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• v.36 no.6_1
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• pp.1323-1337
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• 2020

GEO-KOMPSAT-2A AMI (Advanced Meteorological Imager) radiometric calibration evaluation is an essential element not only for functional and performance verification of the payload but for the quality of the sensor data. AMI instrument consists of six reflective channels and ten thermal infrared ones. One of the key parameters representing radiometric properties of the sensor is a SNR (Signal-to-Noise Ratio) for the reflective channels and a NEdT (Noise Equivalent delta Temperature) for the IR ones respectively. Other important radiometric calibration parameters are a dynamic range and a gain value related with the responsivity of detectors. To verify major radiometric calibration performance of AMI, an offline radiometric evaluation tool was developed separately with a real-time AMI data processing system. Using the evaluation tool, validation activities were carried out during the GEO-KOMPSAT-2A In-Orbit Test period. The results from the evaluation tool were cross checked with those of the HARRIS, which is the AMI payload vendor. AMI radiometric evaluation activities were conducted through three phases for both sides (Side 1 and Side 2) of AMI payload. Results showed that performances of the key radiometric properties were outstanding with respect to the radiometric requirements of the payload. The effectiveness of the evaluation tool was verified as well.

• Progress in Medical Physics
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• v.21 no.2
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• pp.201-208
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• 2010

Recently, along with technology development of endoscopic equipment, a stent has been developed for the convenience of operation, shortening of recovery times, and reduction of patient's pain. To this end, optimal factors are simulated for the stent structure and mechanical reaction and verified using finite element analysis. In order to compare to present commercialized product such as Zilver (Cook, Bloomington, Indiana, USA) and S.M.A.R.T (Cordis, Bridgewater Towsnhip, New Jersey, USA), mechanical impact factors were determined through Taguchi factor analysis, and flexibility and expandability of all the products including ours were tested using finite element analysis. Also, important factors were sought that fulfill the optimal condition using central composition method of response surface analysis, and optimal design were carried out based on the important factors. From the centra composition method of Response surface analysis, it is found that importat factors for flexibility is stent thickness (T) and unit area (W) and those for expandability is stent thickness (T). In results, important factors for optimum condition are 0.17 mm for stent thickness (T) and $0.09\;mm^2$ for unit area (W). Determined and verified by finite element analysis in out research institute, a stent was manufactured and tested with the results of better flexibility and expandability in optimal condition compared to other products. Recently, As Finite element analysis stent mechanical property assessment for research much proceed. But time and reduce expenses research rarely stent of optimum coditions. In this research, Important factor as mechanical impact factor stent Taguchi factor analysis arrangement to find flexibility with expansibility as Finite element analysis. Also, Using to Center composition method of Response surface method appropriate optimized condition searching for important factor, these considering had design optimized. Production stent time and reduce expenses was able to do the more coincide with optimum conditions. These kind of things as application plan industry of stent development period of time and reduce expenses etc. be of help to many economic development.