• Journal of the Institute of Electronics Engineers of Korea SP
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• v.41 no.6
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• pp.19-24
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• 2004

A novel fast parallel NTGST is proposed for high resolution computer vision inspection of the BLUs in a LCD production line. The conventional computation- intensive NTGST algorithm is modified and its C codes are optimized into fast NTGST to be adapted to the SIMD parallel architecture. And then, the input inspection image is partitioned and allocated to each of the P processors in multi-threaded implementation, and the NTGST is executed on SIMD architecture of N data items simultaneously in each thread. Thus, the proposed inspection system can achieve the speedup of O(NP). Experiments using Dual-Pentium III processor with its MMX and extended MMX SIMD technology show that the proposed parallel NTGST is about Sp=8 times faster than the conventional NTGST, which shows the scalability of the proposed system implementation for the fast, high resolution computer vision inspection of the various sized BLUs in LCD production lines.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2012.05a
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• pp.884-886
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• 2012

As the existing radiation Scanning systems use 2-dimensional radiation scanned images, the low accuracy has been pointed out as a problem of it. Two-dimensional radiation images which have different disparity values are acquired from a newly designed stereo image acquisition system which has one additional line sensor to the conventional system. In this paper, we enhanced the scanning efficiency of the stereo X-ray inspection system using the precision control module.

• Journal of Biosystems Engineering
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• v.30 no.3 s.110
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• pp.172-178
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• 2005

Grading and sorting an indeterminate form of agricultural products such as sweet potatoes and potatoes are a labor intensive job because its shape and size are various and complicate. It costs a great deal to sort sweet potato in an indeterminate forms. There is a great need for an automatic grader fur the potatoes. Machine vision is the promising solution for this purpose. The optical indices for qualifying weight and appearance quality such as shape, color, defects, etc. were obtained and an on-line sorting system was developed. The results are summarized as follows. Sorting system combined with an on-line inspection device was composed of 5 sections, human inspection, feeding, illumination chamber, image processing & control, and grading & discharging. The algorithms to compute geometrical parameters related to the external guality were developed and implemented for sorting the deformed sweet potatoes. Grading accuracy by image processing was $96.4\%$ and the processing capacity was 10,800 pieces per hour.

• Journal of the Korea institute for structural maintenance and inspection
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• v.7 no.3
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• pp.133-138
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• 2003

As concrete structures are heated, thermal strain can be developed. Because of the boundary conditions, the thermal stress may be arisen. Thermal strain and temperature were measured simultaneously using an optical fiber sensor. Fiber Bragg Grating Sensor(FBG sensor) was used in the measurement. Because it can measure the strains more than two points with one line, it was possible to measure both thermal strain and temperature with one line. To compare data measured by FBG sensor, strain and temperature were measured using strain gauge and thermocouple. The FBG sensor could measure the strain under the temperature greater than $60^{\circ}C$ but strain gauge couldn't. Both the FBG temperature sensor and thermocouple could measure the temperature and the results are related each other linearly.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.06a
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• pp.1079-1082
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• 2005

This paper deals with the algorithm development that inspects defects such as Lens Focus, Focus check, Black Defect, Dark Defect, Dim Defect, Color Defect, and Line Defect, Angle Defect, IrisAgc Defect caused by the process of 2M Class Compact Camera Module (CCM). Domestic market was majorly comprised of VGA(0.3 million pixel) market. But in the middle of year 2004, camera phone with Mega Pixel has appeared, and it is estimated that the camera phone with Mega Pixel will take up to 28% of total phone sales if it is released in the end of year 2004. Since the inspection of finished products is done manually, it is major obstacle in production increment In this paper, to solve these problems, we developed the imaging processing algorithm to inspect the defects in captured image of assembled CCM. The performances of the developed inspection system and we can recognize various types of defect of CCM modules with good accuracy and high speed

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.22 no.5
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• pp.545-551
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• 2011

In this paper, we described a measurement method of an EIRP(Effective Isotropic Radiated Power) of a WCDMA base station using a pilot channel in line-of-sight environments. Especially we measured it in real base station environments in order to apply this method to domestic base station inspection test. Estimated EIRP results from measured value is -2 dB lower than theoretical values, which is calculated by the data of transmit antenna. The deviation of -2 dB is verified as a polarization mismatch between the base station antenna and a receiver antenna, and it can be calibrated. Therefore, we verified that our measurement method could be an effective tool to measure an EIRP in WCDMA base station inspection test.

• The Transactions of the Korea Information Processing Society
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• v.7 no.6
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• pp.1973-1979
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• 2000

Driving the need for machine vision system is growing consumer demand for quality and defect-free products. Especially it is the most important in tarpaulin's manufacturing process achieves automatically by machine vision instead of by man vision. In this paper pinholes detection is performed by using morphology algorithms. Top hat transform is one of morphology applications. This transform take high performance of defect detection in the case that unexpected changes occur in some non-uniform background. For pinholes defect, automatic visual inspection system has been developed, which was composed by a line-scan camera, illumination, a frame grabber, a motor driver and control units. This system has excellent capacity to defect pinholes to the 0.1 mm by 0.5 mm in size and to work in moving objects by maximum 20 m/min in speed.

• Journal of the Korean Society for Nondestructive Testing
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• v.31 no.4
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• pp.367-373
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• 2011

Guided waves inspection techniques that are different with inspection technique by bulk waves are widely used in pipe line evaluation due to advantages of long distance inspection. However, most of pipe lines at industrial fields are buried and/or coated. In this case, due to the attenuation effect from soil and/or coating material, there are a lot of difficulty on inspection by conventional ultrasonic technique. In this paper, guided waves propagating patterns are calculated with respect to excitation mode by Normal Mode Expansion(NME). Guided waves patterns based on excited by single transducer and guided wave focusing technique have employed to analyze focusing pattern on a pipe. A longitudinal mode and high order flexural modes are used with various number of transducers to determine sensitivity. Guided waves energy excited by multi transducer with focusing algorithm was successfully focused at a desired point.

• Nuclear Engineering and Technology
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• v.32 no.2
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• pp.180-190
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• 2000

In this study, nonlinear analyses of prestressed concrete(PSC) test beams for inservice inspection of prestressed concrete containments for CANDU nuclear power plants are presented. In the analysis the material nonlinearities of concrete, rebar and prestressing steel are used. To reduce the numerical instability with respect to the used finite element mesh size, the tension stiffening effect has been considered. For concrete, the tensile stress-strain relationship derived from tests is modified and the stress-strain curve of rebar is assumed as a simple bilinear model. The stress-strain curve of prestressing steel is applied as a multilineal curve with the first straight line up to 0.8fpu. To prove the validity of the applied material models, the behavior and strength of the PSC test specimens tested to failure have been evaluated. A reasonable agreement between the experimental results and the predictions is obtained. Parametric studies on the tension stiffening effects, the impact of prestressing losses with time, and the compressive strength of concrete have been conducted.

• Proceedings of the KSR Conference
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• 2007.05a
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• pp.893-898
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• 2007

At present, one of the big characteristics in electric power market in korea is unique seller but in the near future competitions are expected in the market. so additional service for the electric power are expected. Also with development of IT technology, remote inspection for power usage are possible so as consumption pattern analysis. KORAIL is one of the biggest consumer in electric power market so it is necessary to investigate power consumption pattern. This paper presents electric load consumption pattern for representative substation like urban subway, high-speed train, industrial line and simulation program for electric power rate definition program based on billing system database. Base on the substation annual power usage DB data, the characteristic of the substation power consumption are investigated and effective electrical billing system are compared each other. Through this program it is verified that we can save more then several hundred million won for a year.