• Transactions of the Korean Society for Noise and Vibration Engineering
• /
• v.15 no.11 s.104
• /
• pp.1241-1247
• /
• 2005

An automation of primary vibration calibration system was developed and tested. Using GPIB interface, the console PC make the control of equipments, signal collecting and save measuring results automatically by the instructions in the program by Visual Basic. Several trials of automatic calibration for the accelerometer(ENDEVCO 2270) using this developed system give the reliable results.

• Journal of the Korean Society for Railway
• /
• v.14 no.5
• /
• pp.404-410
• /
• 2011

In AC feeding system, the fault location is calculated by using ratio of current absorbed in the neutral point of AT(Automatic Transformer) or by measuring reactance. In this way, however, an estimation error can be happened due to the many reasons. In addition, for measuring currents in the neutral point of AT, other measuring devices and communication equipments are additionally required. In order to solve the disadvantages, this paper suggests a novel technique using the distribution ratio of catenary current. The proposed technique uses existing protective relays and measures catenary current. With the measured data, we can calculate the distribution ratio of catenary current and determine fault location. Through the simulated results, we derived the correlation between current ratio and fault location. Using this technique, additional equipments and expenses can be reduced. Besides, fault location can be determined more correctly.

• Transactions of the Korean Society of Mechanical Engineers B
• /
• v.34 no.3
• /
• pp.325-331
• /
• 2010

Three-cup anemometers are popular devices for measuring wind speeds in automated weather stations, environmental monitoring systems, and wind turbines. Cup anemometers usually suffer from lack of long-term stability owing to the wear of the bearing systems that support the rotational parts. The bearing systems are susceptible to external pollutants, vibrations, and gusts. Therefore, these anemometers have to be calibrated regularly to maintain the desired characteristics for measuring wind speed. In the present study, a new in-situ calibration system to help reduce cost and save time by calibrating the cup anemometers at the installation site is proposed. A portable in-situ calibrator was fabricated. After the characteristics of this calibrator were verified, it was used to calibrate cup anemometers. Some of the calibration results were compared with the data obtained by wind tunnel testing.

• Journal of the Korean Geosynthetics Society
• /
• v.17 no.4
• /
• pp.11-19
• /
• 2018

Although many researches related to monitoring and automatic measuring devices for early warning system during slope failure have been carried out in Korea and aboard, most of the researches have installed measuring devices on the slope surface, and there are only few researches about warning systems that can detect and warn before slope failure and disaster occurs. In this study, slope failure simulation experiment was performed by attaching sensors to rock bolts, and initial slope behavior characteristics during slope failure were analyzed. Also, the experiment results were compared and reviewed with varied slope conditions, i.e. shotcrete slope and natural slope, and varied material conditions, i.e. GFRP and steel rock bolt. This study can be used as a basic data in development of warning and alarm system for early evacuation through early detection and warning before slope failure occurs in steep slopes and slope failure vulnerable areas.

• Journal of the Institute of Electronics Engineers of Korea SC
• /
• v.49 no.1
• /
• pp.80-87
• /
• 2012

We have developed the ATE(Automatic Test Equipment) system for the performance test of pre-amplifier of thermal imaging devices. The device regenerates the electronic signals of photon detection module which is normally in weak energy, for the image signals processing. Previous ATE system was primarily and actively developed in the field of semiconductor devices quality parts inspection. Recently, it has been studied in the field of performance testing of equipment. In the field of thermal performance test equipment, however, it lacks the study of ATE compared to other areas, which causes the maintenance related to the core of military thermal imaging system maintenance to be limited. In this paper, a new study of ATE in the field of thermal imaging system is done. It is designed to be used universally for the ATE system with different types of circuit card of thermal imaging system by adopting matrix relays. Using the developed ATE measuring the pre-amplifier amplitude, an average amplified amplitude of 2.71Vpp was measured which confirms that it is within the range of theoretical analysis and also verifies the good performance of the developed ATE.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.16 no.12
• /
• pp.8927-8932
• /
• 2015

A directional feeding method at the railway transformer is applied for supplying the power to the electric railway substations, and the pre-installed facilities with common feeder are utilized in preparation for the failure of feeding system and in finding a fault location in case that the catenary failure occurs. However, it is some difficulty in finding the fault location since there is an interface problem with the facilities when the supplying power system operates. In this paper, Auto Fault Locator Transfer Drive System (ALTDS) is designed to search for the fault location efficiently, and the measuring data are obtained and compared with the KORAIL standards. Further, the ground connection test is accomplished 24 times as the verification method, and it is shown that the methodology provides better performance than the existing traditional one.

• The KIPS Transactions:PartB
• /
• v.9B no.6
• /
• pp.727-734
• /
• 2002

Currently. people become interested in the development of measuring instrument related to eyesight. In this study, we developed software of electronic part in automatic refracto-keratometer. If an automatic system, which uses images from an optical instrument, can inform the in-spector of an accurate eyesight measured value after the internal process, the frequency of mistakenly observed value will be reduced considerably. This software is using morphological filtering and gray-level signal enhancing techniques. The morphological filtering is the first process, from images of the optical instrument, to transform an original image which is hard to process into manageable one. The second process is a signal enhancing technique to the first processed image using gray -level thresholding technique and is used to reduce an error caused by the variety in distribution of the gray value of image. Therefore, this software system in electronic part will make more effective eyesight measurement by reducing the error effectively when applied to the optical image which is difficult to get accurate measurement value.

• Korean Journal of Radiology
• /
• v.22 no.11
• /
• pp.1764-1776
• /
• 2021

Objective: This study aimed to validate a deep learning-based fully automatic calcium scoring (coronary artery calcium [CAC]_auto) system using previously published cardiac computed tomography (CT) cohort data with the manually segmented coronary calcium scoring (CAC_hand) system as the reference standard. Materials and Methods: We developed the CAC_auto system using 100 co-registered, non-enhanced and contrast-enhanced CT scans. For the validation of the CAC_auto system, three previously published CT cohorts (n = 2985) were chosen to represent different clinical scenarios (i.e., 2647 asymptomatic, 220 symptomatic, 118 valve disease) and four CT models. The performance of the CAC_auto system in detecting coronary calcium was determined. The reliability of the system in measuring the Agatston score as compared with CAC_hand was also evaluated per vessel and per patient using intraclass correlation coefficients (ICCs) and Bland-Altman analysis. The agreement between CAC_auto and CAC_hand based on the cardiovascular risk stratification categories (Agatston score: 0, 1-10, 11-100, 101-400, > 400) was evaluated. Results: In 2985 patients, 6218 coronary calcium lesions were identified using CAC_hand. The per-lesion sensitivity and false-positive rate of the CAC_auto system in detecting coronary calcium were 93.3% (5800 of 6218) and 0.11 false-positive lesions per patient, respectively. The CAC_auto system, in measuring the Agatston score, yielded ICCs of 0.99 for all the vessels (left main 0.91, left anterior descending 0.99, left circumflex 0.96, right coronary 0.99). The limits of agreement between CAC_auto and CAC_hand were 1.6 ± 52.2. The linearly weighted kappa value for the Agatston score categorization was 0.94. The main causes of false-positive results were image noise (29.1%, 97/333 lesions), aortic wall calcification (25.5%, 85/333 lesions), and pericardial calcification (24.3%, 81/333 lesions). Conclusion: The atlas-based CAC_auto empowered by deep learning provided accurate calcium score measurement as compared with manual method and risk category classification, which could potentially streamline CAC imaging workflows.

• Resources Recycling
• /
• v.17 no.6
• /
• pp.43-49
• /
• 2008

In this study, a scrap sorting system using a color recognition method has been developed to automatically sort out specified materials from a mixture, and its application as been examined in the separation of Cu and other non-ferrous metal parts from a mixture of iron scraps. The system is composed of three parts; measuring, conveying and ejecting parts. The color of scrap surface is recognized by the measuring part consisting of a line-scan camera, light sources and a frame grabber. The recognition is program-controlled by a image processing algorithms, and thus only the scrap part of designated color is separated by the use of air nozzles. In addition, the light system is designed to meet a high speed of sorting process with a frequency-variable inverter and the air nozzled ejectors are to be operated by an I/O interface communication with a hardware controller. In the functional tests of the system, its efficiency in the recognition of Cu scraps from its mixture with Fe ones reaches to more than 90%, and that in the separation more than 80% at a conveying speed of 25 m/min. Therefore, it is expected that the system can be commercialized in the industry of shredder makers if a high efficiency ejecting system is realized.

• Journal of the Korean Society of Manufacturing Technology Engineers
• /
• v.7 no.6
• /
• pp.72-79
• /
• 1998

In this paper, image processing algorithm is studied to enhance the preciseness of the geometry while converting captured images to CAD data. A program is developed as a result. The code, in the image processing, utilizes outline trace, point data smoothing algorithm. It is capable of automatically generating design data by converting input image data to the CAD data. The output can be made in DXF, IGES formats. The current research can be utilized as a base data for the development of factory automation or flexible manufacturing system which adopt image processing based automatic inspection and measuring system.