• Journal of Biosystems Engineering
• /
• 제43권2호
• /
• pp.103-109
• /
• 2018

Purpose: This study has been conducted to develop a potato yield monitoring system, consisting of a segmentation algorithm to detect potatoes scattered on a soil surface and a counting system to count the number of potatoes and convert the data from two-dimensional images to masses. Methods: First, a segmentation algorithm was developed using top-hat filtering and processing a series of images, and its performance was evaluated in a stationary condition. Second, a counting system was developed to count the number of potatoes in a moving condition and calculate the mass of each using a mass estimation equation, where the volume of a potato was obtained from its two-dimensional image, and the potato density and a correction factor were obtained experimentally. Experiments were conducted to segment potatoes on a soil surface for different potato sizes. The counting system was tested 10 times for 20 randomly selected potatoes in a simulated field condition. Furthermore, the estimated total mass of the potatoes was compared with their actual mass. Results: For a $640{\times}480$ image size, it took 0.04 s for the segmentation algorithm to process one frame. The root mean squared deviation (RMSD) and average percentage error for the measured mass of potatoes using this counting system were 12.65 g and 7.13%, respectively, when the camera was stationary. The system performance while moving was the best in L1 (0.313 m/s), where the RMSD and percentage error were 6.92 g and 7.79%, respectively. For 20 newly prepared potatoes and 10 replication measurements, the counting system exhibited a percentage error in the mass estimation ranging from 10.17-13.24%. Conclusions: At a travel speed of 0.313 m/s, the average percentage error and standard deviation of the mass measurement using the counting system were 12.03% and 1.04%, respectively.

• 한국산학기술학회논문지
• /
• 제10권12호
• /
• pp.3863-3869
• /
• 2009

최근 자동차산업에서의 시장의 세계화와 증가하는 고객의 까다로운 욕구는 다양한 제품의 증가와 제조업체가 공급해야 하는 생산라인의 다양한 방식의 증가로 이어지게 되었다. 또한, 자동차 생산시스템의 모듈화는 자동차부품 공급업체들의 생산시스템에도 많은 영향을 미치고 있다. 이러한 변화는 혼합형 모델 조립라인이라 불리는 비용 효율적이고 유연한 생산시스템의 구현을 요구하고 있다. 본 논문에서는 이러한 혼합형 모델 조립에서 발생하는 여러 문제점들과 이러한 조립오류를 방지할 수 있는 기술에 대해 살펴보고, 혼합형 모델 자동차부품 조립라인에서 RFID를 이용한 오류방지 모니터링시스템을 개발하였다. 특히, 자동차부품 조립현장에서 일어나는 부품의 잘못된 설치와 누락과 같은 문제점들을 최소화하기 위하여 RFID를 이용한 모니터링시스템을 개발함으로써 문제점을 해결하고 조립오류를 예방하여 기존의 시스템을 보완하고자 하였다.

• 제어로봇시스템학회:학술대회논문집
• /
• 제어로봇시스템학회 2003년도 ICCAS
• /
• pp.1196-1200
• /
• 2003

The degree of supersaturation is an important measure for the operation of crystallization processes, because it is directly related to the control of crystal size distribution and shape. A conventional technique utilizing solution composition and temperature has a variety of problems caused from the measurement error and the handling of analyzing samples. A monitoring system of the supersaturation using a quartz crystal sensor is proposed here, and its performance is examined applying different manipulations of coolant temperature. The experimental outcome and photographic examination indicate that the measurements of resonant frequency and resistance of the sensor can be used for the prediction of the formation and growth of solid crystal from the crystallization process. The monitoring system eliminates the intrinsic error source of the conventional system to give the improved measurement and on-line application availability.

• Journal of Biosystems Engineering
• /
• 제25권3호
• /
• pp.233-240
• /
• 2000

A commercially available Doppler radar was modified and evaluated for on-board monitoring of ground speed. The radar output was corrected for pitch angle of aircraft based on the output of an electrolytic tilt sensor. The effects of aircraft speed, height and mounting angle on error in the ground speed were evaluated. The speed error decreased with an increase of the mounting angle since the radar contact angle with respect to the ground approached to the mounting angle. The error increased with an increase of the nominal aircraft speed. The altitude insignificantly affected the speed error. The Doppler radar provided acceptable percent errors within 5% in most measurements. The error can be reduced within ${\pm}$1.5% by increasing the mounting angle ($43^{\circ}$). The error of -3.8% at the mounting angle of $29^{\circ}$could be reduced by adjusting the mounting angle with respect to the radar contact angle.

• 한국컴퓨터정보학회논문지
• /
• 제15권8호
• /
• pp.41-49
• /
• 2010

디지털 방송의 경우 아날로그 방송과 달리 다양한 변수를 포함하고 있으며 디지털의 특성상 에러가 발생할 경우 수신이 전혀 되지 않을 수 있다. 그래서 디지털 방송에는 다양한 변수들을 고려하여 에러에 대응할 수 있도록 모니터링 시스템을 운영하고 있다. ATSC Mobile DTV는 기존의 주파수를 그대로 사용하면서 Mobile 방송을 함께 제공하는 시스템으로, 기존의 시스템과의 간섭이나 영향이 발생 할 수 있기 때문에 실시간 방송상황을 모니터링 하고 에러 발생 시 이를 관리자에게 알려줄 수 있는 모니터링 프로그램이 요구된다. 이에 본 논문에서는 ATSC Mobile DTV 실시간 방송 상태를 감시하고, 수신감도가 좋지 않거나 동영상 스트림 오류등과 같은 문제가 발생 했을 시 이를 관리자에게 알려 안정된 디지털 방송시스템을 유지할 수 있는 효율적인 모니터링 시스템을 제안한다.

• 전기학회논문지P
• /
• 제60권2호
• /
• pp.99-104
• /
• 2011

In this paper, the intelligent landscape lighting power control and monitoring system with solar sell generator equipment is proposed. The first, the intelligent landscape lighting power controller is designed using the fuzzy logic control method. And the fuzzy logic controller is used to save power consumption for various reference intensity of the illumination. The second, the GUI monitoring system is presented. It has control and display faculty. And the practical experiment device is used to evaluate the performance criteria of the proposed intelligent landscape lighting power control system with the solar cell power generation equipment. From the experiment results, we present the property of proposed fuzzy controller such as steady state error, the tracking and power consumption characteristic for the reference intensity of illumination. And also we show the superiority of power control as well as the characteristic of GUI monitoring system in the proposed system.

• 한국안광학회지
• /
• 제16권2호
• /
• pp.159-165
• /
• 2011

목적: 광학적 모니터링 장비를 이용한 안경렌즈의 무반사 코팅의 신뢰성과 재현성을 연구하였다. 방법: 광학적 모니터링 장비를 이용한 무반사 코팅의 수행 가능성을 확인하기 위해서 Essential Macleod 프로그램을 이용하여 RunSheet 실행과 랜덤 에러 전산시늉을 실시하였다. 전산 시늉 후에 AR coating의 재현성 확인을 위해서 19 배치의 코팅 프로세스를 실시하였다. 결과: 19 배치의 코팅 프로세스 반사율 결과는 약 0.5%의 에러 내에서의 좋은 재현성을 보였다. 결론: 결과들로부터 우리는 광학적 모니터링 법을 이용한 무반사 코팅의 가능성과 우수한 재현성을 확인하였다.

• 대한산업공학회지
• /
• 제36권4호
• /
• pp.230-242
• /
• 2010

In this paper, an environmental monitoring and diagnosis system based on ubiquitous computing technology, shortly u-Eco Monitoring System, is proposed. u-Eco Monitoring System is designed to: 1) Collect information from the manufacturing processes via ubiquitous computing technology, 2) Analyze the current status, 3) Identify the cause of problem if detected by rule-based and case-based reasoning, and 4) Provide the results to the operator for proper decision making. Based on functional modeling, a generic architecture is derived, followed by application to a manufacturing system in iron and steel making industry. Finally, to show the validity of the proposed method, a prototype is developed and tested. The developed methods can be used as a conceptual framework for designing environmental monitoring and diagnosis system for industrial practices by which monitoring accuracy and response time for abnormal status can be significantly enhanced, and relieving operator pressure from manual monitoring and error-prone decision making.

• Nuclear Engineering and Technology
• /
• 제49권7호
• /
• pp.1555-1562
• /
• 2017

A loose part monitoring system is used to identify unexpected loose parts in a nuclear reactor vessel or steam generator. It is still necessary for the mass estimation of loose parts, one function of a loose part monitoring system, to develop a new method due to the high estimation error of conventional methods such as Hertz's impact theory and the frequency ratio method. The purpose of this study is to propose a mass estimation method using a Markov decision process and compare its performance with a method using an artificial neural network model proposed in a previous study. First, how to extract feature vectors using discrete cosine transform was explained. Second, Markov chains were designed with codebooks obtained from the feature vector. A 1/8-scaled mockup of the reactor vessel for OPR1000 was employed, and all used signals were obtained by impacting its surface with several solid spherical masses. Next, the performance of mass estimation by the proposed Markov model was compared with that of the artificial neural network model. Finally, it was investigated that the proposed Markov model had matching error below 20% in mass estimation. That was a similar performance to the method using an artificial neural network model and considerably improved in comparison with the conventional methods.

• 한국전산구조공학회:학술대회논문집
• /
• 한국전산구조공학회 1994년도 가을 학술발표회 논문집
• /
• pp.95-102
• /
• 1994

This paper presents a Cable Stayed Bridge Construction Management System, which consists of Structural System Identification Method (SSIM), Error Sensitivity Analysis and Optimum Error Adjustment & Prediction System. The 1st System Identification Method builds an error influence matrix using the linear superposition of each error modes. The 2nd SSIM also considers the second error mode term, which shows good error factor estimation. The optimal cable adjustment can be accomplished within the allowable range of both cable tension and camber. The Post processor, constituted with Motif and GL library on SGI platform, is useful for monitoring construction stage management by displaying construction data, adjustment and prediction results at each construction step.