• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.5
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• pp.2113-2120
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• 2013

In this study, an efficient machine vision based inspection system is developed for the in-line measurement of phosphor resin dispensing shapes on LED chip package. Since the phosphor resin (target material) has semitransparent characteristics, illuminated light beam is reflected from the bottom of the chip as well as from the surface. Since such phenomenon can deteriorate inspection reliability, a white LED and a 635nm laser slit beams are experimentally tested to decide suitable illumination optics. Also, specular and diffuse reflection methods are tested to decide suitable optical triangulation. As a result, it can be known that the combination of a white slit beam source and specular reflection method show the best inspection results. The Catmull-Rom spline interpolation is applied to the obtained data to form smoother surface. From the results, it can be conclude that the developed system can be sucessfully applied to the in-line inspection of LED chip packaging process.

• 한국환경농학회:학술대회논문집
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• 2009.07a
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• pp.119-126
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• 2009

In recent years, research at the Environmental Microbial and Food Safety Laboratory (EMFSL), Agricultural Research Service (ARS) has focused on the development of novel image-based sensing technologies to address agro-food safety concerns, and transformation of these novel technologies into practical instrumentation for industrial implementations. The line-scan-based hyperspectral imaging techniques have often served as a research tool to develop rapid multispectral methods based on only a few spectral bands for rapid online applications. We developed a newer line-scan hyperspectral imaging platform for high-speed inspection on high-throughput processing lines, capable of simultaneous multiple inspection algorithms for different agro-food safety problems such as poultry carcass inspection for wholesomeness and apple inspection for fecal contamination and defect detection. In addition, portable imaging devices were developed for in situ identification of contamination sites and for use by agrofood producer and processor operations for cleaning and sanitation inspection of food processing surfaces. The aim of this presentation is to illustrate recent advances in the above agro.food safety sensing technologies.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2011.06a
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• pp.309-310
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• 2011

• Journal of Sensor Science and Technology
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• v.15 no.5
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• pp.328-333
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• 2006

Magnetic Flux Leakage (MFL) methods are widely employed for the nondestructive evaluation (NDE) of gas pipelines. In the application of MFL pipeline inspection technology, corrosion anomalies are detected and identified via their leakage filed due to changes in wall thickness. The gas industry is keenly interested in automating the interpretation process, because a large amount of data to be analyzed is generated for in-line inspection. This paper presents a novel approach to the tasks of data segmentation, feature extraction and depth estimation from gas pipelines. Also, we will show that the proposed method successfully identifying artificial defects.

• Journal of the Korea Safety Management & Science
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• v.10 no.3
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• pp.253-265
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• 2008

In this paper, we developed a heuristic algorithm to assign job to workers in parallel line inspection process without sequence. Objective of assigning job in inspection process is only to assign job to workers evenly. But this objective needs much time and effort since there are many cases in assigning job and cases increase geometrically if the number of job and worker increases. In order to solve this problem, we proposed heuristic algorithm to assign job to workers evenly. Experiments of assigning job are performed to evaluate performance of this heuristic algorithm. The result shows that heuristic algorithm can find the optimal solution to assign job to workers evenly in many type of cases. Especially, in case there are more than two optimal solutions, this heuristic algorithm can find the optimal solution with 98% accuracy.

• Proceedings of the KIEE Conference
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• 2005.10b
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• pp.421-423
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• 2005

Power transmission lines have been playing a key role as the mainstay of national industry. When a power failure occurs, it can have severe effects on national security as well as national industry and economy. In this paper, we consider an insulator failure, which is one of the main causes of such a power failure. In spite of its importance, however, a shortage of manpower in the insulator maintenance field is getting more serious due to working environments with a high voltage and a high place. For this reason, a new active maintenance technique using a robot system is required to prevent such an insulator failure. In this paper, a new robot mechanism for insulator cleaning and inspection was developed. We confirmed its effectiveness through experiments.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1994.10a
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• pp.748-754
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• 1994

This paper deals with a geometric error simulator, measurement and inspection of workpiece errors on the machine tools, and identification and compensation methodology of thermal errors in machining centers. In order to raise the machining accuracy of workpieces a measurement and inspection system on the machine tool is developed. By using MPPGT module Manual and CNC type CMMs are realized on the machining centers. To compensate for geometric and thermal deformation errors of machining centers, a real time and an off line geometric adaptive control system were developed on the machining centers. A vertical and a horizontal machining center equipped with FANUC 0MC were used for experiments. Performance of the systems were confirmed with a large amount of experiment.

• Proceedings of the KIEE Conference
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• 1997.07b
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• pp.406-408
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• 1997

This paper presents the new method of a nondestructive spot welding state inspection system using neural networks. The learning process of neural networks makes the inspection system to adapt the variable welding parameters. The inspecting process is working with on-line real-time after off-line learning process. This neural network based inspection system shows reliable results through the field test for variations of applied voltages, currents, and contact area of the welding electrode.

• Journal of the Korea Safety Management & Science
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• v.14 no.1
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• pp.167-177
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• 2012

In this paper, we raised the performance of heuristic algorithm to assign job to workers in parallel line inspection process without sequence. In previous research, we developed the heuristic algorithm. But the heuristic algorithm can't find optimal solution perfectly. In order to solve this problem, we proposed new method to make initial solution called FN(First Next) method and combined the new FN method and old FE method using previous heuristic algorithm. Experiments of assigning job are performed to evaluate performance of this FE+FN heuristic algorithm. The result shows that the FE+FN heuristic algorithm can find the optimal solution to assign job to workers evenly in many type of cases. Especially, in case there are optimal solutions, this heuristic algorithm can find the optimal solution perfectly.

• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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• 2006.11a
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• pp.281-284
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• 2006

After building a ship in a shipyard, there are so many repeated inspection of welding seam defects and painting status before delivering to the ship's owner. An inspection on the bottom part of a ship in commercial service should be done in every two years for the purpose of safety and for the prevention of ship speed deterioration. conventional welding seam inspection systems are rely on the visual inspection by human or the ultrasonic inspection for the selective part of a ship. This paper suggests a remote controlled inspection system for the examination of large ships or steel structures. The proposed system moves in contact with the ship under inspection and have a CCD camera to provide visual-guidance information to a remotely located human worker. Additionally this system utilizes a weld line tracking algorithm for an optimal position control. We verified the effectiveness of the inspection system by experimental data.