• Composites Research
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• v.20 no.5
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• pp.49-55
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• 2007

Nanocomposite blade for dicing semiconductor wafer is investigated for micro/nano-device and micro/nano-fabrication. While metal blade has been used for dicing of silicon wafer, polymer composite blades are used for machining of quartz wafer in semiconductor and cellular phone industry in these days. Organic-inorganic material selection is important to provide the blade with machinability, electrical conductivity, strength, ductility and wear resistance. Maintaining constant thickness with micro-dimension during shaping is one of the important technologies fer machining micro/nano fabrication. In this study the fabrication of blade by wet processing of mixing conducting nano ceramic powder, abrasive powder phenol resin and polyimide has been investigated using an experimental approach in which the thickness differential as the primary design criterion. The effect of drying conduction and post pressure are investigated. As a result wet processing techniques reveal that reliable results are achievable with improved dimension tolerance.

• Journal of Korea Game Society
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• v.16 no.3
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• pp.27-34
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• 2016

New game systems have emerged with the rapid growth of Korea smartphone game industry. Especially auto battle system introduced in RPG which is the most popular genre, which has brought a significant change in the understanding of the computer games. To understand this change, it is necessary to look at what circumstances did emerge auto battle system. What is important here is the smart phone as the technical apparatus which defines the presence of a smart phone game, and the use pattern of the smart phone. the technical device and Its use pattern are affecting the activity of the user how to play the game, game developers are to create the game system according to this play style. By examining the appearance and growth of this auto battle system, we can confirm that the micro changes in the game system, reflect changes in the present form of a computer game. This fact will widen the understanding of the history of computer games.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.06a
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• pp.577-580
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• 2005

Surface quality of a micro-processed sample with laser has been investigated by using of scanning confocal microscope(SCM) and atomic force microscope(AFM). Samples are bump electrodes and ITO glass of LCD module used in a mobile phone and a wafer surface scribed by UV laser. A image of $140\times120{\mu}m^2$ is obtained within 1 second by SCM because scan speed of a x-axis and y-axis are 1kHz and 1Hz, respectively. AFM is able to measure correctly hight and width of ITO and scribing depth and width of a wafer with a resolution less than 300 . However, the scan speed is slow and it is difficult to distinguish a surface composed of different nm kinds of materials. Results show that SCM is preferable to obtain a image of a sample composed of different kinds of material than AFM because the intensity of a reflected light from surface is different from each material.

• Journal of the Korea Society of Computer and Information
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• v.13 no.6
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• pp.211-216
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• 2008

Gap fillar antennas are needed for serving the high quality of DMB through the cellular phone by eliminating the shadow regions among buildings or underground. We implement Quadrifilar Helical Antenna using phase difference with PCB feeding lines without coaxial cables and four impedance matching circuits. It is shown that the antenna characteristics is affected by the size and diameter through the simulation process using MicroWave Studio and it is applied for implementing QHA. Experiment results confirm that the performance can be gained as same as the simulation data by using the phase difference with PCB feeding lines without additional impedance matching circuits.

• Spatial Information Research
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• v.20 no.2
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• pp.129-136
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• 2012

Recently international organizations such as ISO/TC211, OGC, INSPIRE (Infrastructure for Spatial Information in Europe) make an effort to share geospatial data using semantic web technologies. In addition, smart phone and social networking services enable community-based opportunities for participants to share issues of a social phenomenon based on geographic area, and many researchers try to find a method of extracting issues from that. However, serviceable spatial ontologies are still insufficient at application level, and studies of spatial information extraction from SNS were focused on user's location finding or geocoding by text mining. Therefore, a study of extracting spatial phenomenon from social media information and converting it into geosemantic knowledge is very usable. In this paper, we propose a framework for extracting keywords from micro-blog, one of the social media services, finding their relationships using data mining technique, and converting it into spatiotemopral knowledge. The result of this study could be used for implementing a related system as a procedure and ontology model for constructing geoseem antic issue. And from this, it is expected to improve the effectiveness of finding, publishing and analysing spatial issues.

• Journal of the Microelectronics and Packaging Society
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• v.18 no.3
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• pp.59-65
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• 2011

According to the trends of electronic package to be smaller, thinner and more integrative, Flip Chip Ball Grid Array (FCBGA) become more used for mobile phone. However, the flip chip necessarily generate the heat by the electrical resistance and generated heat is increased due to reduced distribution area of the heat in accordance with the miniaturization trend of the package. Thermal issues can result in problems of devices that are sensitive to temperature and stress. Then the heat can generate problems to the system. In this paper, in order to improve the thermal issues of FCBGA, thermal characteristics of FCBGA was analyzed qualitatively by using the general heat transfer module of Comsol 3.5a and In order to solve thermal issues, flip chip with new micro structure is proposed by the simulation. and also by comparing existing model and analyzing variables such as pitch, height of the pattern and shape of the heat spreader, the improvement of heat dissipation characteristics about 18% was confirmed.

• The Journal of the Korea institute of electronic communication sciences
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• v.10 no.5
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• pp.607-614
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• 2015

In this paper, we propose about NFC-based mobile Easy Payment System. Already announced about kind of similar payment system by use smart phone NFC function. However this proposition system will uses an encrypted token and user indirect authentication. This feature makes through to simplify payment without other input necessary information. Also my proposition system has easy security certification process. This mean my system does not adequately to use payment of a large amount. But in retail payment will be very useful payment system.

• Journal of Multimedia Information System
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• v.5 no.3
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• pp.215-220
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• 2018

This work presents a smart water quality sensor for hydroponic plant growing applications. The proposed sensor can effectively measure pH level and electrical conductivity of the water solution. The micro-controller incorporated in the sensor processes the raw sensor data, and converts it into a readable format. In addition, through the mobile interface realized using a WiFi module, the sensor can send data to the web server database that collects and stores the data. The data stored in the web server can be accessed by a personal computer or smart phone. The prototype sensor has been implemented, and the operations have been verified under an actual hydroponic plant growing application.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.6 no.2
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• pp.214-220
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• 2002

If neither a map, nor geographic-information processing equipment or a micro browser was prepared in a move terminal in the case of the old system, traffic guidance processing was not able to be carried out. Even if this system was required and did not carry out above -mentioned equipment or an above-mentioned system with a move terminal or a cellular phone, it could be made to do it. Traffic information guidance processing is possible to be completed only by the general telephone or electronic mail transmission.

• Speech Sciences
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• v.7 no.1
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• pp.217-232
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• 2000

In this study, I investigate the role of post-consonantal fundamental frequency (F0) as a cue for automatic distinction of types of Korean stops and affricates. Rather than examining data obtained by restricting contexts to a minimum to prevent the interference of irrelevant factors, a relatively natural speaker independent speech corpus is analysed. Automatic and statistical approaches are adopted to annotate data, to minimise speaker variability, and to evaluate the results. In spite of possible loss of information during those automatic analyses, statistics obtained suggest that vowel F0 is a useful cue for distinguishing manners of articulation of Korean non-continuant obstruents having the same place of articulation, especially of lax and aspirated stops and affricates. On the basis of the statistics, automatic classification is attempted over the relevant consonants in a specific context where the micro-prosodic effects appear to be maximised. The results confirm the usefulness of this effect in application for Korean phone recognition.