http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Estimating Indoor Radio Environment Maps with Mobile Robots and Machine Learning
황태웅,Mario R. Camana Acosta,Carla E. Garcia Moreta,구인수 한국인터넷방송통신학회 2023 International journal of advanced smart convergenc Vol.12 No.1
Wireless communication technology is becoming increasingly prevalent in smart factories, but the rise in the number of wireless devices can lead to interference in the ISM band and obstacles like metal blocks within the factory can weaken communication signals, creating radio shadow areas that impede information exchange. Consequently, accurately determining the radio communication coverage range is crucial. To address this issue, a Radio Environment Map (REM) can be used to provide information about the radio environment in a specific area. In this paper, a technique for estimating an indoor REM using a mobile robot and machine learning methods is introduced. The mobile robot first collects and processes data, including the Received Signal Strength Indicator (RSSI) and location estimation. This data is then used to implement the REM through machine learning regression algorithms such as Extra Tree Regressor, Random Forest Regressor, and Decision Tree Regressor. Furthermore, the numerical and visual performance of REM for each model can be assessed in terms of R2 and Root Mean Square Error (RMSE).
황태웅,김성욱,김문선,장소익,김성호,이상윤,최은영,박수진,권혜원,임효빈 대한심장학회 2017 Korean Circulation Journal Vol.47 No.2
Background and Objectives: The aim of this study was to investigate the effect of pulmonary valve replacement (PVR) on exercise capacity and determine cardiopulmonary exercise (CPEX) parameters associated with improvement in right ventricle (RV) function. Subjects and Methods: We retrospectively analyzed CPEX and magnetic resonance imaging parameters in a total of 245 patients who underwent PVR from January 1998 to October 2015. In addition, we analyzed the characteristics of the patients who showed improved exercise capacity after PVR. Results: Twenty-eight patients met the inclusion criteria for the study. CPEX parameters after PVR showed no significant changes in all patients. However, baseline predicted peak oxygen uptake (VO2peak) (%) value was significantly lower in patients with significant improvement in exercise capacity after PVR, as compared to patients who showed decreased exercise capacity after PVR (60.83±10.28 vs. 75.81±13.83) (p=0.003). In addition, patients with improved exercise capacity showed a positive correlation between the change of right ventricular ejection fraction (RVEF) (%) and the change of anaerobic threshold (r=0.733, p=0.007); whereas, patients with decreased exercise capacity showed a negative correlation between the change of RVEF (%) and the change of predicted VO2peak (%) (r=-0.575, p=0.020). Conclusion: The importance of predicted VO2peak (%) in evaluating exercise capacity differentiated from other CPEX variables. The change of anaerobic threshold and predicted VO2peak (%) might be a useful predictor of the change in RV function after PVR.
전력선 통신과 비컨을 활용한 선박 건조 현장의 작업자 위치 추적 시스템
황태웅,이영두,박기웅,구인수,Taewoong Hwnag,Young-Doo Lee,Ki-Woong Park,In-Soo Koo 한국인터넷방송통신학회 2024 한국인터넷방송통신학회 논문지 Vol.24 No.2
This paper discusses the modeling and implementation of a worker location system at a shipbuilding site. The importance of worker location in an industrial environment is highlighted as a critical element in the prevention of industrial accidents. The paper presents a worker tracking system that integrates power line and beacon communication to accurately track worker position. Through experiments, the paper demonstrates how to monitor the changes in worker location based on different scenarios and how to access the status of worker location using the manager's web service. The paper can be used for the design of a system that will provide real-time location information to safety managers for the improvement of worker safety management.
운항 해역별 자율운항선박 원격운항 상황 발생 확률 추산 시뮬레이션 모델
황태웅,황태민,이다인,박혜인,윤익현 해양환경안전학회 2023 해양환경안전학회지 Vol.29 No.7
With the technological innovation owing to the 4th industrial revolution, the maritime transportation is rapidly being developed with autonomous ships and systems. Particularly, autonomous ships will partially replace the manned ships and navigation among them remotely upon the degree of autonomy suggested by IMO. Accordingly, the remote operator and related research have increased as well. However, the data on the minimum required manpower for remote operators are lacking such as considering engage required situations and their co-occurrence probability. Therefore, this study proposes a simulation model that calculates the number of remote engage required situations by defining restricted water area and remote engage required situation as close-quarter situations based on accumulated trajectory data of actual ships. The findings are expected to be used as background materials to establish the appropriate manpower distribution of remote operators in remote operation centers. 4차 산업혁명의 도래로 인한 기술혁신은 자율운항선박을 중심으로 해상 운송분야까지 활발한 발전을 불러왔다. 특히, 현재의 선원이 직접 운항하는 방식인 유인선박 사이에서 운항하게 될 자율운항선박은 자율도에 따라 원격제어를 통해 운항을 수행하며, 육상에서 이를 제어할 원격운항자에 대한 관심 또한 늘어나고 있다. 하지만 아직 원격운항자가 개입이 필요한 상황이 동시에 발생하는 등을 고려한 원격운항자 최소 인력 요구사항에 대한 연구는 부족한 상황이다. 본 연구는 특정 해역 구간의 누적된 항적데이터를 활용하여 선박 간에 발생할 수 있는 조우상황에서 원격운항자의 개입이 필요한 상황을 정의하고, 해당 구간을 특정 규모의 자율운항선박 선대로 운항하였을 때, 원격운항자의 개입이 동시에 필요한 상황이 얼마나 발생하는지를 시뮬레이션을 통해 확인하였다. 연구의 결과는 향후 실제 자율운항선박 선대를 운행할 원격운항센터의 원격운항자의 적정인력 배치 등의 계획 또는 정책 수립에 활용될 기초 자료로 활용될 것으로 기대한다.