• Journal of the Institute of Electronics Engineers of Korea CI
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• v.40 no.4
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• pp.193-205
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• 2003

There has been so many research activities about robot soccer system in the many research fields, for example, intelligent control, communication, computer technology, sensor technology, image processing, mechatronics. Especially researchers research strategy for attacking in the field of strategy, and develop intelligent strategy. Then, soccer robots cannot defense completely and efficiently by using simple defense strategy. Therefore, intention extraction of attacker is needed for efficient defense. In this thesis, intention extractor of soccer robots is designed and developed based on FMMNN(Fuzzy Min-Max Neural networks ). First, intention for soccer robot system is defined, and intention extraction for soccer robot system is explained.. Next, FMMNN based intention extractor for soccer robot system is determined. FMMNN is one of the pattern classification method and have several advantages: on-line adaptation, short training time, soft decision. Therefore, FMMNN is suitable for soccer robot system having dynamic environment. Observer extracts attack intention of opponents by using this intention exactor, and this intention extractor is also used for analyzing strategy of opponent team. The capability of developed intention extractor is verified by simulation of 3 vs. 3 robot succor simulator. It was confirmed that the rates of intention extraction each experiment increase.

• Proceedings of the Korea Society for Energy Engineering kosee Conference
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• 2006.05a
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• pp.412-419
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• 2006

An Experimental study was conducted on $CO_{2}$ recycle combustion heating system using pure oxygen instead of conventional air as an oxidant, which is thereby producing a flue gas of mostly $CO_{2}$ and water vapor($H_{2}O$ and water vapor($H_{2}O$) and resulting in higher $CO_{2}$ concentration. The advantages of the system are not only the ability to control high temperatures characteristic of oxygen combustion with recycling $CO_{2}$ but also the possibility to reduce NOx emission in the flue gas. A small scale industrial reheating furnace simulator and specially designed variable flame burner were used to characterize the $CO_{2}$ recycle oxy-fuel combustion, such as the variations of furnace pressure, temperature and composition in the flue gas during recycle. It was found that $CO_{2}$ concentration in the flue gas was about 80% without $CO_{2}$recycle. The furnace temperature and pressure and pressure were decreased due to recycle and the NOx emission was also reduced to maintain under 100ppm.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.47 no.1
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• pp.20-27
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• 2010

This paper describes a design of 5-stage pipelined de-blocking filter with power reduction scheme and proposes a efficient memory architecture and filter order for high performance H.264/AVC Decoder. Generally the de-blocking filter removes block boundary artifacts and enhances image quality. Nevertheless filter has a few disadvantage that it requires a number of memory access and iterated operations because of filter operation for 4 time to one edge. So this paper proposes a optimized filter ordering and efficient hardware architecture for the reduction of memory access and total filter cycles. In proposed filter parallel processing is available because of structured 5-stage pipeline consisted of memory read, threshold decider, pre-calculation, filter operation and write back. Also it can reduce power consumption because it uses a clock gating scheme which disable unnecessary clock switching. Besides total number of filtering cycle is decreased by new filter order. The proposed filter is designed with Verilog-HDL and functionally verified with the whole H.264/AVC decoder using the Modelsim 6.2g simulator. Input vectors are QCIF images generated by JM9.4 standard encoder software. As a result of experiment, it shows that the filter can make about 20% total filter cycles reduction and it requires small transposition buffer size.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.38 no.12
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• pp.1223-1231
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• 2010

The design is presented for a SATCOM antenna capable of simultaneous multi-band (X/Ku/Ka-Band) communications without replacement of feed horns or change of other parts in the application as a ground satellite terminal for large data transfer. The antenna is the offset configuration and consists of a dual-band(X/Ka-band) feed horn, a single-band(Ku-band) feed horn, a frequency selective surface(FSS) sub-reflector and a parabolic main-reflector. The antenna has a main reflector defining a prime focus and a frequency selective surface sub-reflector defining an image focus. A dual-band feed and a single-band feed are provided at each of the prime focus and image focus. The antenna is designed using 3D EM simulator and the gains measured in X/Ku/Ka-band of the complete antenna assembly is more than 31.6dBi, 36.8dBi, 40.8dBi, and the cross polarization is 21.7dB, 26.6dB, 25.2dB, respectively.

• The KIPS Transactions:PartB
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• v.12B no.3 s.99
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• pp.349-356
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• 2005

Artificial Organism-used application areas are expanding at a break-neck speed with a view to getting things done in a dynamic and Informal environment. A use of general programming or traditional hi methods as the representation of Artificial Organism behavior knowledge in these areas can cause problems related to frequent modifications and bad response in an unpredictable situation. Strategies aimed at solving these problems in a machine-learning fashion includes Genetic Programming and Evolving Neural Networks. But the learning method of Artificial-Organism is not good yet, and can't represent life in the environment. With this in mind, this research is designed to come up with a new behavior evolution model. The model represents behavior knowledge with Classification Rules and Enhanced Backpropation Neural Networks and discriminate the denomination. To evaluate the model, the researcher applied it to problems with the competition of Artificial-Organism in the Simulator and compared with other system. The survey shows that the model prevails in terms of the speed and Qualify of learning. The model is characterized by the simultaneous learning of classification rules and neural networks represented on chromosomes with the help of Genetic Algorithm and the consolidation of learning ability caused by the hybrid processing of the classification rules and Enhanced Backpropagation Neural Network.

• Journal of KIISE:Information Networking
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• v.32 no.1
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• pp.20-28
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• 2005

TCP(Transmission Control Protocol) is one of the most important Internet protocols, which is widely used in wireless networks as well as wired networks. However, when TCP is deployed for wireless networks, it takes severe performance degradation because TCP was designed for wired network. To overcome this drawback, a number of TCP variants have been proposed in the literature. However, most previous schemes did not consider TCP enhancement over heterogeneous networks. In heterogeneous networks, an mobile node (MN) may move from one access network to another(i.e., vertical handover). In the case of vertical handover, an MN experiences a TCP performance degradation caused by the packet loss and the sudden change of link characteristics between two different access networks. In this work, we investigate the TCP performance degradation occurred in vortical handover across heterogeneous networks. First, we have conducted the measurement study over GPRS-WLAN testbed. In the measurement study. we observed the TCP performance degradation in the case of handover from WLAN to GPRS. In order to study more different TCP behaviors during vertical handover, we performed comprehensive simulations using a network simulator 2(ns-2). Based on measurement and simulation results, we investigated how to improve TCP performance in vertical handover and we concluded that the existing mechanisms cannot be perfect solutions and new mechanisms are strongly required.

• Journal of radiological science and technology
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• v.42 no.6
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• pp.447-454
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• 2019

In order to improve and supplement the shielding method for electron beam treatment, we designed a patient-specific shielding method using a 3D printer, and evaluated the usefulness by comparing and analyzing the distribution of electron beam doses to adjacent organs. In order to treat 5 cm sized superficial tumors around the lens, a CT Simulator was used to scan the Alderson Rando phantom and the DICOM file was converted into an STL file. The converted STL file was used to design a patient-specific shield and mold that matched the body surface contour of the treatment site. The thickness of the shield was 1 cm and 1.5 cm, and the mold was printed using a 3D printer, and the patient customized shielding block (PCSB) was fabricated with a cerrobend alloy with a thickness of 1 cm and 1.5 cm. The dosimetry was performed by attaching an EBT3 film on the surface of the Alderson Rando phantom eyelid and measuring the dose of 6, 9, and 12 MeV electron beams on the film using four shielding methods. Shielding rates were 83.89%, 87.14%, 87.39% at 6, 9, and 12 MeV without shielding, 1 cm (92.04%, 87.48%, 86.49%), 1.5 cm (91.13%, 91.88% with PSCB), 92.66%) The shielding rate was measured as 1 cm (90.7%, 92.23%, 88.08%) and 1.5 cm (88.31%, 90.66%, 91.81%) when the shielding block and the patient-specific shield were used together. PCSB fabrication improves shielding efficiency over conventional shielding methods. Therefore, PSCB may be useful for clinical application.

• Korean Journal of Optics and Photonics
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• v.22 no.4
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• pp.191-197
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• 2011

In this paper, we have designed an integrated triplexer which is the basic component for a FTTH(Fiber To The Home) system which can transmit CATV and voice/data at the same time in a single fiber. The integrated triplexer can be fabricated with a novel technique of "Micro-Block Stacking (MBS)" method which automatically aligns the optical components in the optical beam pass using accurate ceramic holders. We analyze the displacement of the optical focus according to the tolerances of the component dimensions and the assembly process using code V simulator. For the transmitter, the most serious shift of the focal points is caused by the displacements of the LD spot. So the focal point moves up to $72{\mu}m$ from the center point for ${\pm}25{\mu}m$, ${\pm}25{\mu}m$, ${\pm}30{\mu}m$ displacements. For the receiver the most serious shift of the focal points is caused by the displacements of a 0.8mm ball lens (for the analog receiving part) and a micro ball lens (for the digital receiving part), and the focal point moves up to $55{\mu}$ for ${\pm}55{\mu}m$, ${\pm}5{\mu}m$, ${\pm}55{\mu}m$ micro ball lens displacements.

• Journal of Korean Ophthalmic Optics Society
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• v.13 no.2
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• pp.43-50
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• 2008

Purpose: The purpose of this study is to evaluate the effect of a VR (Virtual Refractor), which is a simulator for a PR (Practical Refraction), as an educational tool. Methods: Twenty four third year students enrolled in the department of visual optics volunteered for VR education. Each student attended a VR training course and practiced with the VR by themselves. One month later, each student tested three virtual subjects on the VR and one real subject on the PR and were given a performance score for each refraction. And the scores for the virtual and practical refractions were compared. In addition, a self-report questionnaire based on a five point Likert-scale was designed, consisting of domains such as spontaneous participation, contribution for the refraction, confirmity of the VR and PR, and necessity of the VR. Results: The Spearman's correlation coefficient between the testing score of the practical and virtual refractions indicated a significantly correlation (R=0.71, p<0.001). In the questionnaire, the mean score of the domains was 3.67${\pm}$0.96 and it indicated that students expressed that using the VR was beneficial. The correlation value among these domains was a high significant level, 0.91~0.68 (p<0.001). Conclusions: Although the VR required certain improvements in its concentration and systematic approaches for practical situations, it showed a high correlation between the VR and the PR and represented a positive evaluation in the PR.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2017.05a
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• pp.559-562
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• 2017

In city, tracing of power transmission lines is difficult due to compound installation of overhead and underground lines, transposition, bad view caused by trees or big buildings. It is hard problem for electrical technician on site to trace power transformers or power lines to serve customers in 3 phase -4 wires power distribution systems. It is necessary that the correct and fast tracing method is required for load balancing among distribution lines. Old technology use to trace off-lines with high power impulse injection. Our proposed method use to trace live lines with very small power high frequency signal injection. Typical power transformers in the distribution system prevent propagating the higher frequency carrier signal. The proposed method uses the limited propagation ability to identify the power transformer to serve customers. Two end communication terminals are required to be synchronized between them for determination on electrically same phases. Challenging issue is to achieve synchronization without GPS providing synchronizing time. A novel power transformer and wire identification system is designed and implemented. The system consists of a transmitter and a receiver with power-line communication module. Some experiments are conducted to verify the theoretical concepts in a big commercial building. Also some simulations are done to help and understand the concepts by using MATLAB Simulink simulator.