• The Transactions of the Korean Institute of Electrical Engineers D
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• v.55 no.4
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• pp.161-164
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• 2006

In this thesis we designed the vision system to inspect the defect of a back light unit of plat panel display device. The vision system is divided into hardware and inspection algorithm of defect. Hardware components consist of illumination part, robot-arm controller part and image-acquisition part. Illumination part is made of acrylic panel for light diffusion and five 36W FPL's(Fluorescent Parallel Lamp) and electronic ballast with low frequency harmonics. The CCD(Charge-Coupled Device) camera of image-acquisition part is able to acquire the bright image by the light coming from lamp. The image-acquisition part is composed of CCD camera and frame grabber. The robot-arm controller part has a role to let the CCD camera move to the desired position. To take inspections of surface images of a flat panel display it can be controlled and located every nook and comer. Images obtained by robot-arm and image-acquisition board are saved on the hard-disk through windows programming and are tested whether there are defects by using the image processing algorithms.

• Journal of Korea Multimedia Society
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• v.7 no.8
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• pp.1058-1065
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• 2004

Embedded system is widely used in various applications from simple monitor to a set-top box with CPU, memory and hard disk drives. Specially, embedded OS is ported in moveable or small machinery since it ordinarily transmits multimedia data. In this paper, we propose Null copy scheme on the embedded linux system for multimedia service, which can reduce memory copy overhead from user address space to kernel one, and vice versa. Since embedded system for networked multimedia service has low level computing power as well as memory, the Null copy scheme can provide more improved QoS. Our image transmission experiment results on embedded linux target board(CPU utilization an Deadline miss rates) installed a web camera have shown that the proposed scheme can increase fast response and lower CPU overhead.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.27 no.11
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• pp.1637-1644
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• 2003

Stereoscopic particle image velocimetry is a measurement technique to acquire three dimensional velocity field by two cameras. With a laser sheet illumination, the third velocity component can be deduced from out-of$.$plane velocity components using a stereoscopic matching method. Most industrial fluid flows are three dimensional turbulent flows, so it is necessary to use the stereoscopic PIV measurement method. However the existing stereoscopic PIV system seems hard to use since it is very expensive and complex. In this study we have developed a Miniature Stereo-PIV(MSPIV) system based on the concept of the Miniature PIV system which we have already developed. In this paper, we address the design and some primitive experimental results of the Miniature Stereo-PIV system. The Miniature Stereo-PIV system features relatively modest performances, but is considerably smaller, cheaper and easy to handle. The proposed Miniature Stereo-PIV system uses two one-chip-only CMOS cameras with digital output. Only two other chips are needed, one for a buffer memory and one for an interfacing logic that controls the system. Images are transferred to a personal computer (PC) via its standard parallel port. No extra hardware is required (in particular, no frame grabber board is needed).

• The Journal of the Korea Contents Association
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• v.9 no.2
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• pp.453-461
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• 2009

In this paper, we design and implement a web-based courseware where learners can do self-directed learning to study Web programming languages such as Html, CSS, JavaScript and Dhtml. Each section consists of text class, movie class, practice class, formative assessment, laboratory and bulletin board. And our courseware makes teachers to teach, assess and give scores to learners on Web. In our Web courseware, learners can play a movie class and practice Web programming codes in one screen simultaneously, and execute codes and confirm a results in the same screen also. Therefore, learners can understand Web programming languages efficiently, which are hard to understand immediately by text.

• Proceedings of the KSME Conference
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• 2002.08a
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• pp.517-520
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• 2002

Stereoscopic particle image velocimetry is a measurement technique to acquire of three dimensional velocity field by two cameras. With a laser sheet illumination, the third velocity component can be deduced by out-of-plane velocity components using a stereoscopic matching method. Industrial fluid flows are almost three dimensional turbulent flows, so it is necessary to use the stereoscopic PIV measurement method. However the existing stereoscopic PIV system seems hard to use since it is very expensive and complex. In this study we have developed a Stereoscopic Miniature PIV(MPIV) system based on the concept of the Miniature PIV system which we have already developed. In this paper, we address the design and some first experimental results of the stereoscopic PIV system. The Stereoscopic MPIV system features relatively modest performances, but is considerably smaller, cheaper and easy to handle. The proposed Stereoscopic MPIV system uses two one-chip-only CMOS cameras with digital output. Only two other chips are needed, one for a buffer memory and one for an interfacing logic that controls the system. Images are transferred to a personal computer (PC) via its standard parallel port. No extra hardware is required (in particular, no frame grabber board is needed).

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.11 no.6
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• pp.261-266
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• 2011

Recently, Internet web services including bulletin board of companies, public intuitions, or governments became the main ways of personal information leakage. However, it is hard to succeed to detect personal information and protect it from leakage manually by system administrators, because the number of web boards and attached files is so huge. Therefore, automatic scanning and filtering methods are needed to protect personal information like resident registration numbers from unexpected exposure. To do this, we developed a novel and advanced web security system for automatic personal information scanning and filtering.

• Journal of the Korean Society for Railway
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• v.3 no.3
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• pp.147-153
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• 2000

The train control and monitoring system (TCMS) is an on board computer system in railway vehicles performing the control, supervisory and diagnostic functions of the complete train system. This system replaces a lot of hard-wired relays and minimizes the necessary vehicle wiring thus increasing the reliability of the train. It is also one of more important equipment on vehicle to implement much higher safety and reliability train system. We studied a software design technique of TCMS using a CASE tool that is a kind of safety critical software engineering tool (SCADE). This tool has mainly four functions such as the graphical editor, the document maker, tile automatically code generator, and the test simulator. The several functions of TCMS are implemented in this software easily programmed using a functional block diagram and a graphic programming language. We applied to automatically generated TCMS modules on the SCADE each functional block for the Standard type EMU in Korea. We performed the combination test using TCMS simulator and the running test in Seoul subway 7 Line. We proved that this technique is more useful for the software design of TCMS in urban transit

• Journal of Sensor Science and Technology
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• v.17 no.1
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• pp.15-22
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• 2008

When designing image sensors including a CMOS vision chip for edge detection, resolution is a significant factor to evaluate the performance. It is hard to improve the resolution of a bio-inspired CMOS vision using a resistive network because the vision chip contains many circuits such as a resistive network and several signal processing circuits as well as photocircuits of general image sensors such as CMOS image sensor (CIS). Low resolution restricts the use of the application systems. In this paper, we improve the resolution through layout and circuit optimization. Furthermore, we have designed a printed circuit board using FPGA which controls the vision chip. The vision chip for edge detection has been designed and fabricated by using $0.35{\mu}m$ double-poly four-metal CMOS technology, and its output characteristics have been investigated.

• Journal of Biomedical Engineering Research
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• v.35 no.2
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• pp.26-34
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• 2014

Little information is available about the characteristics in revolution gait of hemiplegic elderly, which is frequently represented in daily life. It is also hard to elucidate purely the characteristics due to hemiplegia because of no consideration of aging factors. The aim of study is to identify the alteration characteristics of lower extremity joint angles in both straight and revolution gaits together due to hemiplegia through comparing healthy with hemiplegic elderly. Following Institutional Review Board approval, twelve healthy and hemiplegic elderly were participated and the center of body mass (COM) and lower extremity joint angles were measured during straight and revolution gaits using a computer-aided video motion capture system. The results showed that the gait characteristics were generally altered in both straight and revolution gaits due to hemiplegia (p < 0.05). The gait characteristics were then different between the straight and revolution gaits each other. This study may be valuable by identifying for the first time the alterations of the lower extremity joint angles in both straight and revolution gaits due to pure hemiplegia through comparing healthy elderly with hemiplegic elderly.

• IE interfaces
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• v.10 no.3
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• pp.75-93
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• 1997

Unlike individual applications, it is extremely hard to obtain user requirements for group systems, since there exists very complicated dynamics in group. This may result in spreading a great amount of products with a broad range of contents. Thus, this study presents a comparative analysis of groupware products. As a result, these products have been categorized into three areas which include cooperation/document management systems, collaborative writing systems, and decision-making/meeting systems. While the systems reviewed here focus on the cooperation/document management systems, the other two areas will be dealt in details in part Ⅱ. The first area ends up with two large categories such as proprietary groupware products and intranet groupware products. However, it has been observed that there is a natural convergence between these two categories. Consequently, the comparative analysis has been performed in terms of functions provided on the two categories and a combined category. Each group of the functions has been divided into three parts which consist of basic functions, quasi-basic functions, and others. Such a decision has been made based on the frequency rate of the functions provided in the products. With a more strict rule, the basic functions comprise electronic mail, sanction, bulletin board, document management, scheduling, security, Web browser, and Internet connectivity. This study also provides a framework for integrated functional model of groupware systems. The basic functions are merged into the model. However, the model is so flexible that it can partially include the quasi-functions in addition to the basic functions. In the future, it is expected that a large number of products will stem from the modification of the functional model.