• Journal of the Korean Society for Precision Engineering
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• v.15 no.5
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• pp.65-71
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• 1998

This paper presents in-process compensation methodology to eliminate cutter runout and improve machined surface quality. The cutter runout compensation system consists of the micro-positioning mechanism with the PZT (piezo-electric translator) which is embeded in the sliding table to manipulate the radial depth of cut in real time. For the implementation of cutter runout compensation methodology. cutting force adaptive control was proposed in the angle domain based upon PI (proportional-integral) control strategy to eliminate chip-load change in end milling process. Micro-positioning control due to adaptive acuation force response improves the machined surface quality by compensation or elimination of cutter runout induced cutting force variation. This results will provide lots of information to build-up the precision machining technology.

• The Journal of the Korea institute of electronic communication sciences
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• v.12 no.4
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• pp.691-700
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• 2017

This paper describes the design and implementation of automatic braille converter based on image processing for a person who is visually impaired. The conversion algorithm based on the image processing converts the input image obtained by the web-cam to binary image, and then calculates the cross-correlation with the stored character pattern image by labeling the character area and converts the character pattern image into the corresponding braille. The computer simulations showed that the proposed algorithm showed 95% and 91% conversion success rates for numerals and alphabets printed on A5 paper. The prototype test implemented by the servo motor using Arduino confirmed 89%, conversion performance. Therefore, we confirmed the feasibility of the automatic braille transducer.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.9 no.4
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• pp.170-178
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• 1984

For the reduction of the 12-channel TDM/FDM translation time the 14-point fast DCT algorithm is used and the polyphase network which translates the prototype filter into the channel filters required in each channel is designed. For the prototype filter the degree of the numerator is 168 and the coefficients have symmetry values, the degree of the numerator is 6. Such a prototype filter is consistant with the CCITT requirements. In this case the required multiplication rate is CCITT requirements. In this case the required multiplication rate is $0.12267{\times}10^2$ multiplications/sec. channel and reduces to about 15-40% of the rate required in the exising systems. The proposed 12-channel TDM/FDM translation system is simulated using a demodulation system with a computer (PRIME 750) and the results show that the proposed conversion method is valid.

• Journal of The Korean Association of Information Education
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• v.5 no.2
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• pp.230-239
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• 2001

Programming education is an important part of the ICT education field, and helps to increase the ability of analyzing, logical thinking, and solving procedural problems. Unfortunately, there is very little chance to learn computer programming nowadays. In addition, students have to install the translating program of the programming language they wish to study. In this paper, we describe the system we designed and implemented on the Internet, which can offer the setting to make programs to run on the WWW. Students can make, edit and run programs on the WWW though they did not set up the language translator program on their local computers.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.7 no.5
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• pp.993-1001
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• 2003

A RDB Storage Model based on the Edge-Labeled Graph is suggested for store the XML instance in Relational Databases(RDB). The XML instance being stored is represented by Data Graph based on the Edge-Labeled Graph. Data Path Table, Element, Attribute, and Table Index Table values are extracted. Then Database Schema is defined, and the extracted values are stored using the Mapper. In order to support querry, Repository Model offers the translator translating XQL which is used as query language under XPATH, into SQL. In addition, it creates DBtoXML generator restoring the stored XML instance. As a result, storage relationship between the XML instance and proposed model structure can be expressed in terms of Graph-based Path, and it shows the possibility of easy search of random Element and Attribute information.

• Journal of Power Electronics
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• v.17 no.1
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• pp.242-252
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• 2017

This paper deals with the blocking of DC-fault current during DC cable short-circuit conditions in HVDC (High-Voltage DC) transmission systems utilizing Modular Multilevel Converters (MMCs), where a new SubModule (SM) topology circuit for the MMC is proposed. In this SM circuit, an additional Insulated-Gate Bipolar Translator (IGBT) is required to be connected at the output terminal of a conventional SM with a half-bridge structure, hereafter referred to as HBSM, where the anti-parallel diodes of additional IGBTs are used to block current from the grid to the DC-link side. Compared with the existing MMCs based on full-bridge (FB) SMs, the hybrid topologies of HBSM and FBSM, and the clamp-double SMs, the proposed topology offers a lower cost and lower power loss while the fault current blocking capability in the DC short-circuit conditions is still provided. The effectiveness of the proposed topology has been validated by simulation results obtained from a 300-kV 300-MW HVDC transmission system and experimental results from a down-scaled HVDC system in the laboratory.

• 제어로봇시스템학회:학술대회논문집
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• 1988.10b
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• pp.794-797
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• 1988

G. Binnig and H. Rohrer introduced the Scanning Tunneling Microscope (STM) in 1982 and developed it into a powerful and not to be missed physical tool. Scanning tunneling Microscopy is a real space surface imaging method with the atomic or subatomic resolution in all three dimensions. The tip is scanned over the surface by two piezo translators mounted parallel (X-piezo and Y-piezo) to the surface and perpendicular to each other. The voltage applied to the third piezo (Z-piezo) translator mounted perpendicular to the surface to maintain the tunneling current through the gap at a constant level reflects then the topography of the surface. The feed back control loop for the constant gap current is designed using the automatic control technique. In the designing process of the feed back loop, the identification of the gap dynamics is very complex and has difficulty. In this research, using some suitable test signals, the system dynamics of the gap including the Z-piezo are investigated. Especially, in this paper, a system model is proposed for the gap and Z-piezo series system. Indicial response is used to find out the model. The driving voltage of the Z-piezo and the tunneling current are considered as input and output signals respectively.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.16 no.5
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• pp.211-217
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• 2007

A nano-imprinting stage has been widely used in various fields of nanotechnology. In this study, an analysis method of a nano-imprinting stage machine using FEM and flexible multi-body kinematics and dynamics has been presented. We have developed a virtual imprinting machine to evaluate the prototype design in the early design stage. The simulation using CAE for the imprinting machine is not only to analyze static and dynamic characteristics of the machine but also to determine design parameters of the components for the imprinting machine, such as dimensions and specifications of actuators and sensors. Structural components as the upper plate, the rotator, the shaft and the translator have been modeled with finite elements to analyze flexibility effects during the precision stage motion. In this paper flexible multi-body dynamic simulation is executed to support robust design of the precision stage mechanism. In addition, we made the 4-axis stage model to compare the dynamic behavior with that of 3-axis stage model.

• JSTS:Journal of Semiconductor Technology and Science
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• v.3 no.4
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• pp.167-174
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• 2003

This paper proposes a network processor especially optimized for content switching. With 2Gbps port capability, it integrates packet processor cluster, content-based classification engine and traffic manager on a single chip. A switch fabric architecture is also designed for scale-up of the network processor's capability over hundreds gigabit bandwidth. Applied in real network systems, the network processor shows wire-speed network address translator (NAT) and content-based switching performance.

• Journal of the Korea Society of Computer and Information
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• v.8 no.4
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• pp.28-34
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• 2003

ASN.1 is the most fundamental technology in network management. The develoment of ASN.1 environment requires three steps : compiler work to parse ASN.1 languages, updating database with the parsing results, and pretty-printing work for data in the database. This paper presents the design and implementation of the translator which automatically translates the specification of ASN.1 to the object-oriented language C++. This system provides a total environment including for various graphic user interface, DB interface, browser to develop ASN.1 for development environment of ASN.1 For the implementation, Objectivity DB is used for database, flex and yacc for compiling, and Tcl/Tk for user interface.