• 제어로봇시스템학회:학술대회논문집
• /
• 제어로봇시스템학회 2004년도 ICCAS
• /
• pp.110-115
• /
• 2004

The hybrid fault diagnosis method based on a combination of the signed digraph (SDG) and the partial least-squares (PLS) has the advantage of improving the diagnosis resolution, accuracy and reliability, compared to those of previous qualitative methods, and of enhancing the ability to diagnose multiple fault. In this study, the method is applied for the multiple fault diagnosis of the Tennessee Eastman challenge process, which is a realistic industrial process for evaluating process contol and monitoring methods. The process is decomposed using the local qualitative relationships of each measured variable. Dynamic PLS (DPLS) model is built to estimate each measured variable, which is then compared with the estimated value in order to diagnose the fault. Through case studies of 15 single faults and 44 double faults, the proposed method demonstrated a good diagnosis capability compared with previous statistical methods.

• 한국소음진동공학회:학술대회논문집
• /
• 한국소음진동공학회 2005년도 추계학술대회논문집
• /
• pp.279-284
• /
• 2005

Knowledge based fault diagnosis has a limitation in determining the cause and scheme for the fault, because it detects faults from signal pattern only Therefore, model-based fault diagnosis is requested to determine the fault by analyzing output of the equipment from its dynamic model. This research shows a method how to devise the automaton of system as a model for normal and faulty condition through the reduction of handling data by quantization of vibration signals and the example which is concerning to the bearing of ATM. The developed model based fault diagnosis was applied to detect the faulty bearing of ATM, which results.

• 대한방사선기술학회지:방사선기술과학
• /
• 제39권3호
• /
• pp.369-376
• /
• 2016

양전자방출단영상(Positron Emission Tomography, PET)은 여러 화합물과 방사성 동위원소를 결합하여 인체 내에 주입하여 인체 내의 대사율을 정량적으로 측정할 수 있는 핵의학적 검사이다. 특히, 암 조직에서 포도당 대사가 증가되는 현상을 $^{18}F$-FDG(Fluorodeoxyglucose)를 사용하여 널리 암 진단에 활용하며, 현대에서 발병 빈도가 높은 뇌질환 중 치매 및 파킨슨 진단에도 높은 유용성을 보인다는 연구가 다수 진행되었다. 이러한 현재의 정적 정보에 시간의 동적 정보를 포함하는 동적 양전자방출단층영상(dynamic PET, dPET)을 이용할 경우, 진단을 위한 추가적인 정보가 제공되므로 진단의 정확도 향상에 기여할 수 있다. 이러한 이유로 임상 연구자 및 방사선사의 큰 관심을 받고 있으나 연구를 진행하기 위해 손쉽게 사용 가능한 도구가 부족한 실정이며, 다양하고 복잡한 수학적 알고리즘(algorithm)이나 프로그래밍(programming) 기술이 부족할 경우 연구의 활성화를 방해하는 높은 진입장벽으로 존재하게 되므로, 본 연구에서는 dPET 연구의 활성화와 손쉬운 사용을 위해서 MATLAB을 이용하여 그래픽 유저(GUI) 기반으로 하여 무료 소프트웨어를 개발하였으며, 개발된 소프트웨어인 DIA-Tool(Dynamic Image analysis-Tool)은 복잡한 수학적 영상 분석 알고리즘을 누구나 손쉽게 사용할 수 있도록 설계되었다. 향후, 많은 임상 연구자들이 DIA-Tool을 이용하여 국내의 dPET 연구 발전에 큰 도움이 될 것이라 기대된다.

• 한국컴퓨터정보학회논문지
• /
• 제16권3호
• /
• pp.141-147
• /
• 2011

본 논문은 유도전동기의 고장검출 및 진단을 위한 효율적인 2-단계 고장예측 알고리즘을 제안한다. 첫 번째 단계에서는 고장 패턴 추출을 위해 선형 예측 부호화 (Linear Predictive Coding: LPC) 기법을 사용하고, 두 번째 단계에서는 고장 패턴 매칭을 위해 동적시간교정법 (Dynamic Time Warping: DTW)을 사용한다. 유도전동기에서 정상 및 각종 이상 상태의 조건을 발생시켜 추출한 샘플링 주파수 8kHz, 샘플링 시간 2.2초의 정상상태 및 비정상 상태의 진동데이터 8개를 사용하여 모의 실험한 결과, 제안한 고장예측 알고리즘은 기존의 고장진단 알고리즘보다 약 45%의 정확도 향상을 보였다. 또한 TI사의 TMS320F2812 DSP를 내장한 테스트베드 시스템을 제작하여 제안한 고장예측 알고리즘을 구현하고 검증하였다.

• 핵의학기술
• /
• 제19권1호
• /
• pp.67-71
• /
• 2015

Purpose At recently, we enter into the aging society and a age-related disease is increasing. Among that, prevalence of degenerative brain disease like Parkin's disease will be increased. So, many radiopharmaceuticals is developed to diagnosis early and to evaluate the performance of therapeutic drugs. Especially $^{18}F-DOPA$ which involved at dopamine synthesis and function of storage is widely used to the diagnosis of Parkinson's disease as well as brain tumors. in the study, we will evaluate the distribution pattern of $^{18}F-DOPA$ at the striatum by using dynamic study. Materials and Methods We used Biograph Truepoint(Siemens, Germany) as PET/CT scanner, injected a $^{18}F-DOPA$ ($600{\pm}30MBq$) to patient (4men, 6women. $67{\pm}11age$) who visited our hospital from June to September, started 95min dynamic study at same time. after finishing acquisition, we reconstructed PET data with 19 frame every 5 minutes, analysed a average counts at ROI's where set at both striatums, anterior putamen, posterior putamen Results Counts in the cerebellum as the background formed a plateau after 90 minutes from the highest out rapidly reduced to 15 minutes. Counts of anterior putamen and posterior gradually increased but formed a plateau after 60min. A count ratio of Striatum to cerebellum was continuously increased up to more than 95 minutes, A count ratios of an anterior putamen to posterior one formed a plateau after 85 minutes. Conclusion The dynamic acquisition can be possible to evaluate a distribution of the $^{18}F-DOPA$ in the striatum and the VOI analysis through a dynamic acquisition and a variety of patterns. Futhermore, to make a uniformed distribution and count ratio of striatum to cerebellum, a static acquisition will have to start 90minutes later after injection.

• 대한전기학회논문지:시스템및제어부문D
• /
• 제49권12호
• /
• pp.643-650
• /
• 2000

Using neural network approach, the diagnosis of faults in industrial process that requires observing multiple data simultaneously are studied. Two-stage diagnosis is proposed to analyze system faults. By using neural network, the first stage detects the dynamic trend of each normalized date patterns by comparing a proposed pattern. Instead of using neural network, the difference between stored fault pattern and real time data is used for fault diagnosis in the second stage. This method reduces the amount of calculation and saves storing space. Also, we dealt with unknown faults by normalizing the data and calculating the difference between the value of steady state and the data in case of fault. A model of tank reactor is given to verify that the proposed method is useful and effective to noise.

• 한국공작기계학회논문집
• /
• 제12권6호
• /
• pp.22-28
• /
• 2003

We should maintain the maximum operation capacity for production facilities and find properly out the fault of each equipment rapidly in order to decrease a loss caused by its failure. The acoustic signals of a machine always carry the dynamic information of the machine. These signals are very useful for the feature extraction and fault diagnosis. We performed a fundamental study which develops a system of fault diagnosis for a pump. We obtained noises by a microphone, analysed and compared the signals converted to Sequency range for normal products, artificially deformed products. We tried to search a change of noise signals according to machine malfunctions and analyse the type of deformation or failure. The results showed that acoustic signals as well as vibration signals can be used as a simple method for a detection of machine malfunction or fault diagnosis.

• 한국공작기계학회:학술대회논문집
• /
• 한국공작기계학회 2003년도 춘계학술대회 논문집
• /
• pp.99-104
• /
• 2003

We should maintain the minimum operation capacity for production facilities and find properly out the fault of each equipment rapidly in order to decrease a loss caused by its failure. The acoustic signals of a machine always carry the dynamic information of the machine. These signals are very useful for the feature extraction and fault diagnosis. We performed a fundamental study which develops a system of fault diagnosis for a pump. We obtained noises by a microphone, analysed and compared the signals converted to frequency range for normal products, artificially deformed products. We tried to search a change of noise signals according to machine malfunctions and analyse the type of deformation or failure. The results showed that acoustic signals as well as vibration signals can be used as a simple method for a detection of machine malfunction or fault diagnosis.

• 대한한의학원전학회지
• /
• 제27권1호
• /
• pp.111-122
• /
• 2014

Objective : The region, observation period, figuration of pulse, pulse frequency, process of diagnosis and related diagnostic methods in traditional pediatric pulse diagnosis were studied in this article. Method : The articles related to traditional pediatric pulse diagnosis in Traditional medical classics, and analysis to the characteristics of it was done, then lastly, the principle of pulse manifestation and the meaning of application to modern times were considered. Result & Conclusion : It is difficult to catch the figuration of pediatric pulse because of dynamic change of body conditions, fast heartbeat and narrow region of pulse. Therefore, the pulse diagnosis appropriated for children have been developed and combined with the special diagnosis methods, for example, palpation of forehead and observation of index finger. The traditional pediatric pulse diagnosis is done with just one finger palpation in the period of 3 to 5 years old to identify the speed, length, size and height of pulse. The standard average of pulse frequency is 7~8 par breath in the period of 3 to 5 years old according to traditional medical classic.

• 대한두개안면성형외과학회지
• /
• 제25권1호
• /
• pp.22-26
• /
• 2024

Background: This study analyzed the demographic characteristics of patients with facial palsy who were treated using either dynamic or static procedures. This study aimed to compare the frequency of procedure implementation and age distribution between the two groups. Methods: This study retrospectively analyzed the medical records of patients treated for facial palsy at a single institution from 2014 to 2022. Among cases included in our study, dynamic procedures involved cross-facial nerve graft and latissimus dorsi or gracilis muscle flap transfer. Static procedures included gold weight insertion, canthopexy, browlift, and thread lift/static slings. Results: Among the 31 patients included in our study, eight (25.8%) incorporated dynamic techniques, and the average age of patients was 44.75 years (range, 24-68 years) with a male to female ratio of 1:4. The remaining 23 patients (74.2%) underwent a static procedure, of which the average age was 59.17 years (range, 23-81 years) which was statistically significantly higher than the average age of 44.75 of dynamic patients (p= 0.013). Regarding the timing of treatment after diagnosis, no patient underwent dynamic procedures more than 20 years after initial diagnosis. A greater diversity in the timing of treatment was observed in the static group. All patients who underwent dynamic procedures were treated using static procedures during the study period. Conclusion: Because aesthetics-based static techniques are typically quick outpatient procedures that can be performed under local anesthesia, our study shows that these are often preferred treatments for all age groups, especially for debilitated or older patients. Further research is required to investigate the long-term functional outcomes of these surgical techniques in a wider population of patients.