• Journal of the Microelectronics and Packaging Society
• /
• v.22 no.1
• /
• pp.15-19
• /
• 2015

We demonstrated an inspection system for detecting discoloration of PCB Cu ball pad with an OSP surface finish. Though the OSP surface finish has many advantages such as eco-friendly and low cost, however, it often shows a discoloration phenomenon due to a heating process. In this study, the discoloration was analyzed with device-independent CIELAB color space. First of all, the PCB samples were inspected with standard lamps and CCD camera. The measured data was processed with Labview program for detecting discoloration of Cu ball pad. From the original PCB sample image, the localized Cu ball pad image was selected to reduce the image size by the binarization and edge detection processes and it was also converted to device-independent CIELAB color space using $3{\times}3$ conversion matrix. Both acquisition time and false acceptance rate were significantly reduced with this proposed inspection system. In addition, $L^*$ and $b^*$ values of CIELAB color space were suitable for inspection of discoloration of Cu ball pad.

• Smart Structures and Systems
• /
• v.11 no.5
• /
• pp.511-531
• /
• 2013

Recent advances in low-cost remote monitoring systems have made it possible and practical to perform structural health monitoring (SHM) on a large scale. However, it is difficult for a single remote monitoring system to cover a wide range of SHM applications due to the amount of specialization required. For the remote monitoring system to be flexible, sustainable, and robust, this article introduces a new cost-effective, advanced remote monitoring and inspection system named DuraMote that can serve as a next generation supervisory control and data acquisition (SCADA) system for civil infrastructure systems. To evaluate the performance of DuraMote, we conduct experiments at two representative counterpart sites: a bridge and water pipelines. The objectives of this article are to improve upon the existing SCADA by integrating the remote monitoring system (i.e., DuraMote), to describe a prototype SCADA for civil engineering structures, and to validate its effectiveness with long-term field deployment results.

• Transactions of the Korean Society of Pressure Vessels and Piping
• /
• v.6 no.1
• /
• pp.9-15
• /
• 2010

This paper describes the Visual Tool for automatic ultrasonic examination that is under developing as a part of the project for development of automatic ultrasonic wave acquisition and analysis program. This tool that is supported by various image processing techniques will be adopted to detect the flaws in the component and piping welds in NPP. Visual Tool will enhance the integrity of nuclear power plant. The object of this paper is to address the Visual Tool which is developing for automatic ultrasonic inspection of welds in NPP.

• Proceedings of the KIEE Conference
• /
• 2004.11c
• /
• pp.385-387
• /
• 2004

In this paper, we have designed a fingerprint cognition system based on the embedded Linux. The proposed algorithm in this paper use the wavelet transform to derive the special feature vector from the captured fingerprint and a probabilistic neural network is used to compare the feature vectors for the fingerprints. The system consists of server PC based on the Linux and the client based on the embedded Linux. The client is a Tynux box-x board using the PXA-255 CPU. For the acquisition of the fingerprint image, we use d the AS-S2 semiconductor sensor. The system is likely to be used to develop a police inspection system.

• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.63 no.3
• /
• pp.418-424
• /
• 2014

A large number of wire rope has been used in various industries such as cranes and elevators. When wire used for a long time, wire defects occur such as disconnection and wear. It leads to an accident and damage to life and property. To prevent this accident, we proposed a wire rope fault detection system in this paper. We constructed the whole system choosing the leakage fault detection method using hall sensors and the method is simple and easy maintenance characteristics. Fault diagnosis and analysis were available through analog filter and amplification process. The amplified signal is transmitted to the computer through the data acquisition system. This signal could be obtained improved results through the digital filter process.

• The Transactions of the Korean Institute of Electrical Engineers P
• /
• v.51 no.2
• /
• pp.87-93
• /
• 2002

Accurate acquisition of surface geometries such as machined surfaces, biological surfaces, and deformed parts have been very important technique in scientific study and engineering, especially for system design, manufacturing and inspection. Two-camera method keeps accuracy more than double than mechanical method. In this paper, a new method is studied to acquire 3D geometric data of the small object such as a die in stone model. When the devices, cameras, laser beam and object are in a perfect plane, the calculation is measured by position error 0.025[mm] within. But this paper shows that arbitrarily positioned system can also be used to obtain 3D data. Also, this paper present a method to generate coping surface data with which CAM system can do for milling work.

• Proceedings of the KIEE Conference
• /
• 2003.07e
• /
• pp.120-123
• /
• 2003

Accurate acquisition of surface geometries such as machined surfaces, biological surfaces, and deformed parts have been very important technique in scientific study and engineering, expecially for system design, manufacturing and inspection. Two camera method keeps accuracy more than double than mechanical method. In this paper, we describe the processes surface data of teeth for automatic processing, transformation that changes to coping data of possible numeric data form, and processed inlay teeth. As the result of the Inlay manufacture, which can process with high resolution, therefore we construct the automatic processing system that depends on manual.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
• /
• 2001.04a
• /
• pp.137-142
• /
• 2001

Since recent production system becomes that of the small quantity, large volume with high quality production, accurate and high speed inspection system is required. In such situation, noncontact 3D measurement system which utilized CCD cameras is useful technique in terms of system cost, speed of data acquisition, measuring accuracy and application. However, it has low accuracy compared with contact 3D measurement system because of the camera distortion, non uniformity of laser distribution and so on. For those reasons, in this paper precision enhancement method is studied considering radial camera distortion, and laser distribution. A distortion correction method is applied even to the standard lens. The laser slit beam trajectory is determined by 3 method: based of the Gaussian function signal approximation, the median method, the center of gravity method and the peak point of the Gaussian function method.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 1997.04a
• /
• pp.56-60
• /
• 1997

The compressor is one of important elements in refrigeration cycle and play an important role of refrigeration efficiency and quality. This paper analyzes slides in rotary compressors for room air conditioners, monitoring using Acoustic Emission(AE) technique. Reliability of rotary compressors which are factory-tested has been evaluated through visual inspection on taking them apart after long term test, which is life test. This paper describes methods for acquisition and processing of Acoustic Emission(AE) raw signal to monitor state of rotary compressor in Life Test.

• Transactions of the Korean Society of Machine Tool Engineers
• /
• v.13 no.5
• /
• pp.118-123
• /
• 2004

The compressor has one of important roles in refrigeration cycle and it determines refrigeration efficiency and quality This paper aims to monitor rotary compressors for room air conditioners by using Acoustic Emission(AE) technique. The reliability of rotary compressors has been evaluated through visual inspection on them after long term test. This paper describes methods for acquisition and processing AE raw signal to monitor the state of rotary compressor. A detecting method of abnormal compressor in real time is suggested and special-purpose monitoring system which can be applied to automatic manufacturing line is developed using one-chip microprocessor at low cost.