• Journal of the Korea Society of Computer and Information
• /
• v.11 no.4 s.42
• /
• pp.299-304
• /
• 2006

This paper is for the on-line monitoring and controlling system in which remote central processor execute commands based on data transmitted via radio or cable captured from the industrial or marine environments. By executing the appropriate system commands, many mechanical parts in industrial environments and natural factors such as temperature and humidity are to be under control in the way of normal system condition. In this research, we control the temperature of a hydrochloric acid tank to be within the predetermined range by executing temperature controlling commands issued by remote central computer which decides the appropriate action for the total system based on the received sensor data transmitted via radio and cable media. This type of monitoring and controlling system has the various applications such as the disaster prevention system, ubiquitous embedded system, alarm system, and the USN systems.

• Proceedings of the Korean Society for Agricultural Machinery Conference
• /
• 2017.04a
• /
• pp.155-155
• /
• 2017

최근 애플망고 스마트 농가에 에너지 사용량이 증가됨에 따라 에너지 절감을 위한 대책들과 화석연료를 대체하는 다양한 신재생에너지 도입에 대한 요구들이 늘고있다. 본 연구에서는 애플망고 스마트 농가에 여러 에너지원들을 혼합하여 사용할 수 있도록 실증시험 모델을 구축하고 운영함으로써 그 효용성을 검토하고자 하였다. 우선 애플망고 특성을 고려한 비닐온실의 최대 냉난방부하량과 에너지모델을 분석하여 신재생 에너지원들의 혼합 및 기존 공조설비와의 연계를 계산하였다. 애플망고 시험 농지로는 재배에 적합한 제주도 서귀포를 선정하였으며, 기존의 경유 난방기를 사용하는 비교시험 하우스, 기존의 경유와 태양광, 지하 공기 히트펌프 난방기를 혼합하여 사용하는 실증시험 하우스, 경유와 지하공기 히트펌프 난방기를 사용하는 대조시험 하우스를 10~11월 두 달간 운영하여 그 결과들을 평가하였다. 온실 내외부에 온도, 습도, CO2를 측정할 수 있는 6점의 센서부들을 설치하였고, 적산 전력계와 유량계를 설치하여 데이터를 수집하였으며, 모든 시험 데이터는 모바일 원격으로 제어 및 모니터링이 가능하도록 구성하였다. 시험 결과, 각 하우스들에서 수확한 과실의 수량과 품질은 유사하게 평가되었지만, 실증시험 하우스의 난방비가 비교시험 하우스보다 절감되었다. 하지만 실증시험 하우스의 경우 높은 시설유지비로 인해 이를 고려한 사용료는 비교시험 하우스보다 더 비싸게 평가되었다. 본 연구를 통해 생산된 잉여전력을 매전할 때 이로 인한 이용비는 비교시험 하우스보다 더 경제적임을 확인할 수 있었다. 또한 기존의 경유와 지하공기 히트펌프 난방기를 혼합한 대조시험 하우스의 난방비용이 경제성에서 더 유리함을 알 수 있었다. 따라서 본 연구를 통해 애플망고 스마트 농가에 적합한 에너지-믹스 모델을 구축할 수 있었으며, 다양한 신재생에너지들의 효용성들을 검토할 수 있었다.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.34 no.10
• /
• pp.1513-1519
• /
• 2010

Recently, on-line process monitoring systems using sensors are being extensively used to produce highquality products. However, the difficulty in installing the sensors within the mold in the cases of micro-molds, optical molds, and molds with complex structures is a serious disadvantage of such process monitoring systems. In this study, the quantitative index of a process monitoring system was evaluated with the mold cavity pressure and the nozzle pressure for the injection molding machine. In order to evaluate the effect of the nozzle pressure, we performed correlation analysis for the weight of the molded product. We also examined the control characteristics of the injection molding machine by analyzing the effect of multistage injection speed, holding pressure, and injection pressure limit on the process monitoring data.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.37 no.9
• /
• pp.1109-1116
• /
• 2013

This study aims to investigate the spatial randomness of fatigue crack growth rate for the friction stir welded (FSWed) 7075-T651 aluminum alloy joints. Our previous fatigue crack growth test data are adopted in this investigation. To clearly understand the spatial randomness of fatigue crack growth rate, fatigue crack growth tests were conducted under constant stress intensity factor range (SIFR) control testing. The experimental data were analyzed for two different materials-base metal (BM) and weld metal (WM)-to investigate the effects of spatial randomness of fatigue crack growth rate and material properties, the friction stir welded (FSWed) 7075-T651 aluminum alloy joints, namely weld metal (WM) and base metal (BM). The results showed that the variability, as evaluated by Weibull statistical analysis, of the WM is higher than that of the BM.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.37 no.3
• /
• pp.365-372
• /
• 2013

In this study, a statistical method for evaluating the fatigue life of a vehicle muffler was used to obtain reliable fatigue data using a limited number of specimens. Cyclic bending tests were conducted using specimens manufactured to be exactly the same as the mufflers installed in cars that are currently in use. To estimate the fatigue life by comparing the data obtained during the fatigue tests, the most suitable probability density function for the normal, lognormal, and Weibull distributions was selected. A goodness-of-fit test was performed on the probability distributions, and then a Weibull distribution using the least square method was selected. By using the selected Weibull distribution, the probability-moment-life curves (P-M-N curve) reflecting the fatigue characteristics were suggested as the data for the reliable design of a muffler.

• 한국방재학회:학술대회논문집
• /
• 2011.02a
• /
• pp.166-166
• /
• 2011

한국건설기술연구원내에 세계 최초로 UHPC(초고성능 콘크리트)를 활용한 보도사장교를 설계 및 시공하여 공용중이다. 초고성능 콘크리트(UHPC, Ultra High Performance Concrete)는 기존의 콘크리트의 단점을 극복하기 위하여 강섬유 및 혼화재료를 사용하여 고강도화와 더불어 인장강도, 휨강도, 균열에 대한 저항성, 전단강도 및 내충격성을 대폭 개선시켜서 구조부재의 연성 및 강도를 확보하기 위해 개발된 것으로서 한국건설기술연구원이 독자적 연구를 바탕으로 UHPC를 개발하였고, KICT-UHPC의 특성을 충분히 반영한 보도사장교를 한국건설기술원내에 실구조물로 시공하였다. 한국건설기술연구원내 본관 1, 2동 연결 보도사장교(SUPER BRIDGE 1)의 진동실험을 통해 UHPC 보도사장교의 동특성(고유진동수 및 모드형상)을 평가하였다. 대상교량에는 보도사장교의 캔틸레버 구조 특성에 의해 발생하는 진동을 제어하기 위한 질량 264kg의 난간형 수직진동제어장치(TMD) 4대가 설치되어 있으며, 부가질량의 운동을 기계적으로 구속하거나 구속을 해제하여 TMD의 작동을 켜거나 끌 수 있도록 되어있다. TMD의 가동 및 정지시 동특성을 비교하는 정밀한 검증 실험을 통하여 TMD 설치에 의한 동특성의 변화도 평가하였다. 가진망치에 의한 충격실험으로부터 획득한 가속도 시간이력 데이터와 가진망치의 가진력 시간이력 데이터를 사용하여 주파수응답함수(FRF, frequency response function)를 계산하고, 이로부터 Super Bridge I의 동적모드형상과 고유진동수를 추출하였다. 1차 모드의 고유진동수는 TMD 정지시 2.2949 Hz, TMD 작동시 2.0996 Hz로서 8%정도 감소하였다. 충격해머에 의한 가진 실험을 통해 세계 최초로 시공한 UHPC 보도사장교의 진동특성과 관련한 신뢰성 있는 자료를 확보할 수 있었다.

• Journal of the Korean Institute of Intelligent Systems
• /
• v.25 no.2
• /
• pp.174-179
• /
• 2015

Failure Mode and Effects Analysis (FMEA) has been used by Dynamic Positioning (DP) system for risk and reliability analysis. However, there are limitations associated with its implementation in offshore project. 1) since the failure data measured from the SCADA system is missing or unreliable, assessments of Severity, Occurrence, Detection are based on expert's knowledge; 2) it is not easy for experts to precisely evaluate the three risk factors. The risk factors are often expressed in a linguistic way. 3) the relative importance among three risk factors are rarely even considered. To solve these problems and improve the effectiveness of the traditional FMEA, we suggest a Fuzzy-FMEA method for risk and failure mode analysis in Dynamic Positioning System of offshore. The information gathered from DP FMEA report and DP FMEA Proving Trials is expressed using fuzzy linguistic terms. The proposed method is applied to an offshore Dynamic Positioning system, and the results are compared with traditional FMEA.

• Journal of Convergence for Information Technology
• /
• v.8 no.6
• /
• pp.217-223
• /
• 2018

Real-time controllability has been a major challenge that should be addressed to ascertain the practical usage of the management systems. In this regards, for the first time, we proposed and implemented an IoT(Internet of Things)-based water tank system to improve convenience and efficiency. The reservoir can be effectively controlled by notifying the user if the condition of the reservoir is unstable. The proposed system consists of embedded H/W unit for sensor data measuring and controling, application S/W for deployment of management server via web and mobile app, and efficient database structure for managing and monitoring statistics. And machine learning algorithms can be applied for further improvements of efficiency in practice.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2022.05a
• /
• pp.27-30
• /
• 2022

The plasma process, which has many advantages in terms of efficiency and environment compared to conventional process methods, is widely used in semiconductor manufacturing. Plasma Sheath is a dark region observed between the plasma bulk and the chamber wall surrounding it or the electrode. The Plasma Sheath Monitoring Sensor (PSMS) measures the difference in voltage between the plasma and the electrode and the RF power applied to the electrode in real time. The PSMS data, therefore, are expected to have a high correlation with the state of plasma in the plasma chamber. In this study, a model for predicting the state of nitrogen ions in the plasma chamber is training by a deep learning machine learning techniques using PSMS data. For the data used in the study, PSMS data measured in an experiment with different power and pressure settings were used as training data, and the ratio, flux, and density of nitrogen ions measured in plasma bulk and Si substrate were used as labels. The results of this study are expected to be the basis of artificial intelligence technology for the optimization of plasma processes and real-time precise control in the future.

• Proceedings of the Korean Information Science Society Conference
• /
• 2010.11a
• /
• pp.21-22
• /
• 2010

Brain-Computer Interface (BCI) 는 뇌 신호를 이용하여 생각으로 기계 및 컴퓨터를 제어 할 수 있는 기술이다. 뇌전도(Electroencephalography, EEG) 를 이용한 본 연구는 왼쪽/오른쪽 손 상상 움직임 실험에 대해서 특징 추출 (feature extraction)에 관�� 연구로 총 9명의 피험자로부터 얻어진 뇌 전도 데이터를 이용하여 전통적인 방법 (Common Spatial Pattern, CSP 및 Fisher Linear Discriminant, FLDA)을 이용해 구한 분류 정확도와 본 논문에서 사용 된 Symbolic transfer entropy (STE)을 통해 얻어진 특징에 대한 결과를 보여 준다. 본 연구를 통하여 STE를 통한 특징 추출 방법이 의미가 있다고 생각한다.