http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Haemin Jeon,Hyuntae Bang,Byeongjun Yu 국제구조공학회 2023 Smart Structures and Systems, An International Jou Vol.32 No.2
This study proposes an automated assembly performance evaluation method for prefabricated steel structures (PSSs) using machine learning methods. Assembly component images were segmented using a modified version of the receptive field pyramid. By factorizing channel modulation and the receptive field exploration layers of the convolution pyramid, highly accurate segmentation results were obtained. After completing segmentation, the positions of the bolt holes were calculated using various image processing techniques, such as fuzzy-based edge detection, Hough's line detection, and image perspective transformation. By calculating the distance ratio between bolt holes, the assembly performance of the PSS was estimated using the k-nearest neighbors (kNN) algorithm. The effectiveness of the proposed framework was validated using a 3D PSS printing model and a field test. The results indicated that this approach could recognize assembly components with an intersection over union (IoU) of 95% and evaluate assembly performance with an error of less than 5%.
Haemin Jeon,Wancheol Myeong,Jae-Uk Shin,Jong-Woong Park,Hyung-Jo Jung,Hyun Myung IEEE 2014 IEEE/ASME transactions on mechatronics Vol.19 No.5
<P>Structural displacement is considered an important indicator to assess structural conditions. To directly measure the displacement in the time domain, a visually servoed paired structured light system was proposed. The system is composed of two sides facing each other, each with one or two lasers that are controlled by a visually servoed two-DOF manipulator, a camera, and a screen. The relative six-DOF displacement between the two sides can be estimated by calculating the positions of the projected laser beams on the screens and the rotation angles of manipulators. To verify the performance of the proposed system, two kinds of field tests were carried out. A prototype of the system was built and installed on a steel frame building structure and a railway bridge, respectively. The estimated displacements were compared with the reconstructed displacement from an accelerometer. The test results verify the performance of the system and its applicability to real structures.</P>
( Haemin Kim ),( Kuijae Lee ),( Jongchan Chae ) 한국미생물 · 생명공학회 2015 Journal of microbiology and biotechnology Vol.25 No.11
Bacillus subtilis HM1 was isolated from the rhizosphere region of halophytes for its antifungal activity against Colletotrichum acutatum, the causative agent of anthracnose. Treatment of postharvest apples with the cell culture or with a cell-free culture supernatant reduced disease severity 80.7% and 69.4%, respectively. Both treatments also exhibited antifungal activity against various phytopathogenic fungi in vitro. The antifungal substances were purified and analyzed by acid precipitation, gel filtration, high-performance liquid chromatography, and matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS). Three compounds were identified as fengycin, iturin, and surfactin. The MALDI-TOF/ TOF mass spectrum revealed the presence of cyclized fengycin homologs A and B, which were distinguishable on the basis of the presence of either alanine or valine, respectively, at position 6 of the peptide sequence. In addition, the cyclized structure of fengycin was shown to play a critical role in antifungal activity.
Incremental Displacement Estimation (IDE) for Structural Health Monitoring Robot
Haemin Jeon,Jae-Uk Shin,Wancheol Myeong,Hyun Myung 제어로봇시스템학회 2012 제어로봇시스템학회 국제학술대회 논문집 Vol.2012 No.10
To measure 6-DOF displacement, a visually servoed paired structured light system (ViSP) has been introduced which is composed of two sides facing with each other, each with one or two lasers, a camera, a screen, and a 2-DOF manipulator. In the system, the lasers on both two sides project their parallel beams to the screen on the opposite side and 6-DOF relative displacement between two sides can be calculated using the positions of the three projected laser beams and the rotation angles of the manipulators. In the estimation process, extended Kalman filter (EKF) or Newton-Raphson method have been used. However, these aforementioned iterative methods have a drawback that the computation time is relatively long due to the multiple iterations. Therefore, in this paper, incremental displacement estimation (IDE) algorithm which updates the previously estimated displacement using the difference of the previous and the current observed data is introduced. To validate the performance of the newly proposed algorithm, various experimental tests have been performed. The results show that the ViSP with the IDE algorithm estimates the 6-DOF relative displacement between two sides with the same level of accuracy of EKF with multiple iterations in significantly reduced time.
Degree of Disturbance Rejection Capability for Linear Marginally Stable Systems
Haemin Lee,Youngjin Park 제어로봇시스템학회 2015 제어로봇시스템학회 국제학술대회 논문집 Vol.2015 No.10
Controllability is a structural property that carries information useful for control system design such as actuator placement. There are several measures to determine the locations and types of actuators, and one of them is degree of disturbance rejection capability (DODR) which is a quantitative measure representing how controllable the system is under the presence of persistent disturbance. However, it is hard to obtain the steady-state solution of DODR if the system is marginally stable because of several problems such as singularity and intensiveness of computation to obtain the Gramians. Thus, this problem to apply the measure to marginally system still remains. In this paper, therefore, the way to apply DODR to marginally systems with simple calculation is proposed. The definition of the measure is same with existing measure of DODR. We used a novel concept of time averaged gradient of Gramians to calculate the steady-state solution of DODR.