• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.22 no.2
• /
• pp.51-56
• /
• 2008

High quality power supplying of high voltage distribution lines electric railway system is the important function, high voltage distribution system is complicated witch is compose with distribution line, circuit break, protection facilities and so on. Among this components, role of substation is most important for elevation of reliability in electric power system. Therefore, the enhanced reliability considering the preventive inspection, repair work replacement is necessary. This paper proposes protection method in railway high voltage distribution lines. we model distribution system using PSCAD/EMTDC(Power System Computer Aided Design/Electro Magnetic Transients DC Analysis Program) and extract various fault data. In conclusion this methods can protection of ground fault.

• Journal of Biosystems Engineering
• /
• v.28 no.1
• /
• pp.45-52
• /
• 2003

Red ginsengs are inspected manually by examining those in the dark room with back light illumination. Manual inspection is often influenced by physical condition of inspectors. Sometimes. the best grade, heaven. has some inner holes though it was inspected by a specialist. In order to resolve this problem, this study was performed to develop image processing algorithm to detect the inner holes in the x-ray image of ginseng. Because of little gray value difference between background and ginseng in the image. simple thresholding method was not appropriate. Modified watershed algorithm was used to differentiate the inner holes from background and normal ginseng body. Inner hole edge region detected by watershed algorithm consists of many number of blobs including normal portions. With line profile analysis with scanning one line at a time beginning the starting point. it shelved two peaks both ends representing extracting each blobs. in which setting threshold value as of lower peak value enabled us to obtain inner hole image. Once this procedure has to be done till the finishing point it is completing inner hole detection for one blob. Thus. conducting ail blobs by this procedure is completing inner detection of one whole ginseng. Detection results of the inner holes fer various size of red ginsengs were good even though there was small detection variation. 6.2%. according to position of x-rat tube.

• The Bulletin of The Korean Astronomical Society
• /
• v.43 no.1
• /
• pp.44.1-44.1
• /
• 2018

We present a spectroscopic study of the Galactic supernova remnant (SNR) Cygnus Loop using the fifth Data Release (DR5) of LAMOST. The LAMOST (Large Sky Area Multi-Object Fiber Spectroscopic Telescope) features both a large field-of-view (about 20 deg2) and a large aperture (~4 m in diameter), which allow us to obtain 4000 spectra simultaneously. Its wavelength coverage ranges from ${\sim}3700{\AA}$ to $9000{\AA}$ with a spectral resolution of $R{\approx}1800$. The Cygnus Loop is a prototype of middle-aged SNRs, which has advantages of being bright, large in angular size (${\sim}3.8^{\circ}{\times}3^{\circ}$), and relatively unobscured by dust. Along the line of sight of the Cygnus Loop, 2747 LAMOST DR5 spectra are found in total, which are spatially distributed over the entire remnant. Among them, 778 spectra are selected based on the presence of emission lines (i.e., [O III]${\lambda}5007$, Ha, and [S II]${\lambda}{\lambda}$ 6717, 6731) for further visual inspection. About half of them (336 spectra) show clear spectral features to confirm their association with the remnant, 370 spectra show stellar features only, and 72 spectra are ambiguous and need further investigation. For those associated with the remnant, we identify emission lines and measure their intensities. Spectral properties considerably vary within the remnant, and we compare them with theoretical models to derive physical properties of the SNR such as electron density and temperature, and shock velocity. While some line ratios are in good agreement with model prediction, others cannot be explained by simple shock models with a range of shock velocities. We discuss these discrepancies between model predictions and the observations and finally highlight the powerfulness of the LAMOST data to investigate spatial variations of physical properties of the Cygnus Loop.

• Journal of the Korean Wood Science and Technology
• /
• v.37 no.1
• /
• pp.37-47
• /
• 2009

For the inspection of wood, machine vision is the most common automated inspection method used at present. It is required to sort wood products by grade and to locate surface defects prior to cut-up. Many different sensing methods have been applied to inspection of wood including optical, ultrasonic, X-ray sensing in the wood industry. Nowadays the scanning system mainly employs CCD line-scan camera to meet the needs of accurate detection of lumber defects and real-time image processing. But this system needs exact feeding system and low deviation of lumber thickness. In this study low cost CCD area sensor was used for the development of image processing system for lumber being fed. When domestic red pine being fed on the conveyer belt, lumber images of irregular term of captured area were acquired because belt conveyor slipped between belt and roller. To overcome incorrect image merging by the unstable feeding speed of belt conveyor, it was applied template matching algorithm which was a measure of the similarity between the pattern of current image and the next one. Feeding the lumber over 13.8 m/min, general area sensor generates unreadable image pattern by the motion blur. The red channel of RGB filter showed a good performance for removing background of the green conveyor belt from merged image. Threshold value reduction method that was a image-based thresholding algorithm performed well for knot detection.

• Journal of the Korean Society for Nondestructive Testing
• /
• v.36 no.3
• /
• pp.195-201
• /
• 2016

Eddy current testing (ECT) is commonly applied for the inspection of automated production lines of metallic products, because it has a high inspection speed and a reasonable price. When ECT is applied for the inspection of a metallic object having an uneven target surface, such as the spline gear of a spline shaft, it is difficult to distinguish between the original signal obtained from the sensor and the signal generated by a defect because of the relatively large surface signals having similar frequency distributions. To facilitate the detection of defect signals from the spline gear, implementation of high-order filters is essential, so that the fault signals can be distinguished from the surrounding noise signals, and simultaneously, the pass-band of the filter can be adjusted according to the status of each production line and the object to be inspected. We will examine the infinite impulse filters (IIR filters) available for implementing an advanced filter for ECT, and attempt to detect the flaw signals through optimization of system design parameters for detecting the signals at the system level.

• Journal of Power System Engineering
• /
• v.12 no.6
• /
• pp.70-77
• /
• 2008

The purpose of this study is to compare the quality of digital radiography image with that of classical film images for welded structure in power plants. The CMOS(Complementary Metal Oxide Semiconductor) flat panel detecter and Agfa D5 film are used to image flaw specimens respectively. In the test, CMOS flat panel detector has been determined to have a better image than that of film image. In the IQI(Image Quality Indicator) transmission test, one or two more line can be seen in digital image than in film image. Digital Radiography Test enabled to successfully detect all defects on the weld specimens fabricated with real reheat stem pipe and boiler tube as well. In the specific comparison test, Digital radiography test detected micro flaws in the size of 0.5 mm in length by 0.5 mm in depth. However, film test has limited it to 1.0 mm in length by 1.0 mm in depth. As a result of this study, digital radiography technology is estimated well enough to perform the inspection in the industry with far more cost effective way, compared to the classical film test.

• Journal of Korea Society of Industrial Information Systems
• /
• v.12 no.1
• /
• pp.95-100
• /
• 2007

In the steel & iron processing line, some characters are marked for the material management in the surface of material. This paper describes about the developed results of vision system for the recognition of material management characters, which was included in the slab image. Our vision system for the character recognition includes that CCD camera system which acquire slab image, optical transmission system which transmit captured image to the long distance, input and output system for the interface with existing system and monitoring system for the checking of recognition results. We have installed our vision system at the continuous casting line and tested. Also, we have performed inspection of durability, reliability and recognition rate. Through the testing, we have confirmed that our system have high recognition rate, 97.4%.

• Journal of the Korean Society of Safety
• /
• v.32 no.3
• /
• pp.15-20
• /
• 2017

This study presented the strength of the materials and parts for smart distribution board fabrication, and developed a work operation process chart for smart distribution board fabrication. This work operation process chart for smart distribution board fabrication complied with SPS-KEMC regulations, and the applicable range and object are less than 1,000 V and 1,000 Hz for the AC distribution board and less than 1,500 V for the DC distribution board. The power supply is 3 phase 4 wires ($3{\Phi}$ 4W), divided into a single phase circuit and a 3 phase circuit. In addition, the circuit was configured so that the leakage current flowing through the distribution line of the load could be monitored in real time by using the sensor module installed at the rear end of the circuit breaker. Therefore, the administrator can easily find the risk factor of the load since engineer can check the leakage current of each distribution line. In addition, if a leakage current greater than standard value flows, it is possible to generate an alarm against a short circuit and cut off the leakage current. The work operation process chart for the smart distribution board fabrication consists of the following steps: raw and subsidiary materials, sheet metal work, tube making, welding, painting, busbar fabrication, assembly and wiring, product inspection, shipment, etc. Moreover, symbols, ${\Delta}$, ${\nabla}$, ${\bigcirc}$, ${\Rightarrow}$, etc. were used according to the type of work and work progress so that workers can easily understand the progress of the work.

• Journal of Arbitration Studies
• /
• v.9 no.1
• /
• pp.291-322
• /
• 1999

The world of today faces a radical change, a new revolution, by the spread of the Internet. It is used not only for advertising but also for the exclusive rights in the field of information and communication, in add to the way of developing everyday our lives with world news, home-shopping, on-line education and so on. Actually, since the Internet Domain's Name(IDN) is unique over the world, the individual and the companies which provide information through the Internet have a keen competition to make a good IDN to memorize and organize all available information provided them. As a result, there are an increasing number of the cases where one company files suit against another for the validity of it's IDN so the policy to arbitrate and solute the cases is required. This paper is going to introduce the structure and the system of management for IDN. It will also discuss the efficient management of IDN, various case analysis of the dispute restraint and solutions, and the movement of improving the management procedure of IDN in WIPO. So we suggest to examine common disputes among IDN uses and solution methods for future problem at EC times. Therefore we have to establish the dispute solution system. Here are the two methods : one is that to establish a dispute solution organization. This organization which can conduct the new dispute solution procedure differs from the existing legislation system. The other is that to establish a dispute solution procedure i.e. the various dispute solution procedure for efficient dispute solution : council, inspection, mediation and arbitration. This procedure is conducted on-line due to features of the IDN disputes, also along with the current legislation system and the International dispute solution procedure. Because there is possibility the IDN disputes usually are connected with other countries. As there is no specific disputes solution procedure so far, we have to wait while development occurs that also striving to be coherent with and between the domestic and International solution procedure by helping to establish the International dispute solution procedure.

• Proceedings of the Korean Geotechical Society Conference
• /
• 2006.03a
• /
• pp.1100-1109
• /
• 2006

In this study, two different technologies which can measure temperature simultaneously at many points are introduced. One is to use a thermal sensor cable that is comprised of addressable thermal sensors connected in parallel within a single cable. The other is to use an optic fiber with Distributed Temperature Sensing (DTS) system. The difference between two technologies can be summarized as follows. A thermal sensor cable has a concept of 'point sensing' that can measure temperature at accurate position of a thermal sensor. So the accuracy and resolution of temperature measurement are up to the ability of the thermal sensor. Whereas optic fiber sensor has a concept of 'distributed sensing' because temperature is measured by ratio of Stokes and anti-Stokes component intensities of Raman backscatter that is generated when laser pulse travels along an optic fiber. It's resolution is determined by measuring distance, measuring time and spatial resolution. The purpose of this study is that application targets of two temperature measurement techniques are checked in technical and economical phases by examining the strength and weakness of them. Considering the functions and characteristics of two techniques, the thermal sensor cable will be suitable to apply to the assessment of groundwater flow, geothermal distribution and grouting efficiency within 300m distance. It is expected that the optic fiber sensor can be widely utilized at various fields (for example: pipe line inspection, tunnel fire detection, power line monitoring etc.) which need an information of temperature distribution over relatively long distance.