• Smart Structures and Systems
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• v.25 no.6
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• pp.679-691
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• 2020

To identify the bridge information from the response of test vehicles passing on it (also known as the indirect approach) has aroused the interest of many researchers thanks to its economy, easy implementation and less disruption to traffic. The surface roughness of bridge remains an obstacle for such method as it contaminates the vehicle response severely and thereby renders many vehicle-response-based bridge identification methods ineffective. This study aims to eliminate such effect with the responses of two different test vehicles. The proposed method can estimate the surface profile of a bridge based on the acceleration data of the vehicles running on the bridge successively, and obtain the normalized contact point response, which proves to be relatively immune to surface roughness. The frequencies and mode shapes of bridge can be further extracted from the normalized contact point acceleration with spectral analysis and Hilbert transform. The effectiveness of the proposed method is verified numerically with a three-span continuous bridge. The influence of measurement noise is also examined.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2011.10a
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• pp.593-596
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• 2011

본 논문에서는 안테나 주변 지형 및 장애물들이 전계강도에 미치는 영향을 알아보기 위하여 두가지 주변 지형을 고려한 전계강도 변화를 살펴보았다. 먼저 안테나 주변 지형의 봉우리 유무에 따른 전계강도 변화는 봉우리가 안테나로부터 200m 떨어진 지점에 높이가 40m, 너비가 30m, $60^{\circ}$의 경사를 갖는 지형이고, 다음으로 봉우리 높이에 따른 전계강도 변화는 경사가 $85^{\circ}$이고, 높이가 h 인 봉우리 지형을 갖는 형태로 구현방법으로는 MWS 시뮬레이터를 이용하여 구현하였다.

• Proceedings of the KIEE Conference
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• 2003.07d
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• pp.2588-2590
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• 2003

The part of manipulators is normally studied with regularized environmental conditions. however, it is the most difficult that the part of AMR must be studied with uncertainty in the environmental conditions. The part of AMR has skelton, sensor fusion, path planning etc. This paper is the research of the local pass planning that gathers information about external environment using neural network from each sensors and designs the algorithm which can determine which correct direction the robot can find. As the result of the research, AMR has been able to drive similarly as if the expert does and has been able to observe it acting without any control.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2006.05a
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• pp.701-705
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• 2006

This paper propose a method of mobile robot path planning for prevention of slip using potential field. The path planning minimizes robot slip for the potential field method to smooth a potential barrier. In order to verify the effectiveness of the proposed method, we performed simulations on path planning with C-obstacles in the workspace. The results show that the proposed method considerably improves on the performance of the general potential field method.

• Proceedings of the Korea Information Processing Society Conference
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• 2018.10a
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• pp.715-718
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• 2018

최근 다층의 인공신경망 모델이 수많은 분야에 대한 해결 방안으로 제시되고 있으며 2015년 Mnih이 고안한 DQN(Deep Q Network)는 Atari game에서 인간 수준의 성능을 보여주며 많은 이들에게 놀라움을 자아냈다. 본 논문에서는 Atari DQN Model을 실내 자율주행 모바일 로봇에 적용하여 신경망 모델이 최단 경로를 추종하며 장애물 회피를 위한 행동을 학습시키기 위해 로봇이 가지는 상태 정보들을 84*84 Mat로 가공하였고 15가지의 행동을 정의하였다. 또한 Virtual world에서 신경망 모델이 실제와 유사한 현재 상태를 입력받아 가장 최적의 정책을 학습하고 Real World에 적용하는 방법을 연구하였다.

• Proceedings of the Korea Information Processing Society Conference
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• 2015.04a
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• pp.822-823
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• 2015

본 논문에서는 휴머노이드 로봇이 더욱 지능적으로 보행할 수 있도록 강화학습을 적용하는 방법을 제안한다. 강화학습을 활용하면 로봇의 이동 경로에 동적으로 이동하는 장애물이 있을 경우 이를 인지하고 회피하여 목적지까지 문제 없이 이동할 수 있다. 실제 환경에서의 실험에 앞서 Unity3D를 활용한 가상 환경에서 이를 구현하여 실험해보았다.

• Psychiatry investigation
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• v.15 no.11
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• pp.1011-1018
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• 2018

The analysis of extracellular vesicles has been accelerated because of the technological advancements in omics methods in recent decades. Extracellular vesicles provide multifaceted information regarding the functional status of the cells. This information would be critical in case of central nervous system cells, which are confined in a relatively sealed biological compartment. This obstacle is more dramatic in psychiatric disorders since their diagnosis primarily depend on the symptoms and signs of the patients. In this paper, we reviewed this rapidly advancing field by discussing definition of extracellular vesicles, their biogenesis and potential use as clinical biomarkers. Then we focused on their potential use in psychiatric disorders in the context of diagnosis and treatment of these disorders. Finally, we tried to combine the RDoC (Research Domain Criteria) with the use of extracellular vesicles in psychiatry research and practice. This review may offer new insights in both basic and translational research focusing on psychiatric disorders.

• Korea Trade Review
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• v.44 no.2
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• pp.37-49
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• 2019

This paper determines if mandated alcohol health information labelling could be an obstacle to international trade by discussing international trade rules affecting member nations. WTO members could use alcohol labelling rules to protect human health, reduce the consumption of alcohol and provide product information. When a member uses alcohol labelling as a technical regulation or standard, it should comply with TBT Articles 2.2 and 2.4. If a member uses some specific warning messages for their objectives, it should be considered the contribution of the measure, trade restrictiveness, and alternatives. If WTO members want to employ their own alcohol labelling schemes for addressing carcinogenicity, intoxicating effects, dependence potential, effects on children, adolescents and pregnancy, it could be a technical barrier and also create adverse effects on international trade. Therefore, the harms of alcohol are supported by scientific evidence, and for this reason, the international harmonization for alcohol labelling should be discussed openly to prevent negative effects on trade.

• Proceedings of the Korea Information Processing Society Conference
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• 2013.05a
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• pp.501-503
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• 2013

This project presents a concept of mobile robots using prototypes, computing proposal oriented to embedded systems implementation. We implement our system using GPS module, Ultrasonic sensor(range sensors), H-bridge dual stepper control, DTMF(Dual-tone Multi-Frequency ) and LCD module. In this paper we construct a mechanical simple mobile robot model, which can measure the distance from obstacle with the aid of sensor and should able to control the speed of motor accordingly. Modules were interfaced with FPGA(Field Programmable Gate Array) controller for hardware implementation.

• Journal of information and communication convergence engineering
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• v.20 no.1
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• pp.31-40
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• 2022

Coronary heart disease (CHD) is a comorbidity of COVID-19; therefore, routine early diagnosis is crucial. A large number of examination attributes in the context of diagnosing CHD is a distinct obstacle during the pandemic when the number of health service users is significant. The development of a precise machine learning model for diagnosis with a minimum number of examination attributes can allow examinations and healthcare actions to be undertaken quickly. This study proposes a CHD diagnosis model based on feature selection, data balancing, and ensemble-based classification methods. In the feature selection stage, a hybrid SVM-GA combined with fast correlation-based filter (FCBF) is used. The proposed system achieved an accuracy of 94.60% and area under the curve (AUC) of 97.5% when tested on the z-Alizadeh Sani dataset and used only 8 of 54 inspection attributes. In terms of performance, the proposed model can be placed in the very good category.