• Journal of the Korean Institute of Intelligent Systems
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• v.22 no.4
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• pp.429-434
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• 2012

This paper presents a technology for manipulating external devices by Brain Computer Interface (BCI) system. Recently, BCI based rehabilitation and assistance system for disabled people, such as patient of Spinal Cord Injury (SCI), general paralysis, and so on, is attracting tremendous interest. Especially, electroencephalogram (EEG) signal is used to organize the BCI system by analyzing the signals, such as evoked potential. The general findings of neurophysiology support an availability of the EEG-based BCI system. We concentrate on the event-related synchronization of motor imagery EEG signal, which have an affinity with an intention for moving control of external device. To analyze the brain activity, short-time Fourier transform and particle swarm optimization are used to optimal feature selection from the preprocessed EEG signals. In our experiment, we can verify that the power spectral density correspond to range mu-rhythm(${\mu}8$~12Hz) have maximum amplitude among the raw signals and most of particles are concentrated in the corresponding region. Result shows accuracy of subject left hand 40% and right hand 38%.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.49 no.3
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• pp.38-46
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• 2012

Atrial fibrillation is needed to be detected at paroxysmal stage and to be treated. But, paroxysmal atrial fibrillation ECG is hardly obtained with 12-lead electrocardiographs but Holter systems. Presently, the averaged beat subtraction(ABS) method is solely used to estimate atrial fibrillatory waves even with somewhat large residual error. As an alternative, in this study, we suggested an ESAF(event-synchronous adaptive filter) based algorithm, in which the AF ECG was treated as a primary input and event-synchronous impulse train(ESIT) as a reference. And, ESIT was generated so to be synchronized with the ventricular activity by detecting QRS complex. We tested proposed algorithm with simulated AF ECGs and real AF ECGs. As results, even with low computational cost, this ESAF based algorithm showed better performance than the ABS method and comparable performance to algorithm based on PCA(principal component analysis) or SVD(singular value decomposition). We also proposed an expanded version of ESAF for some AF ECGs with multi-morphologic ventricular activities and this also showed reasonable performance. Ultimately, with Holter systems including our proposed algorithm, atrial activity signal can be precisely estimated in real-time so that it will be possible to calculate atrial fibrillatory rate and to evaluate the effect of anti-arrhythmic drugs.

• Journal of the Korea Society of Computer and Information
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• v.18 no.1
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• pp.137-147
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• 2013

The RFID(Radio Frequency Identification) and the WSN(Wireless Sensor Network) have technical similarities and mutual effects, they have been recognized to be studied separately, and sufficient studies have not been conducted on the technical integration of the RFID and the WSN. Therefore, EPC global which realized the issue proposed the EPC(Electronic Produce Code) Sensor Network to efficiently integrate and interoperate the RFID and WSN technologies based on the international standard EPC global network. The proposed EPC Sensor Network technology uses the Complex Event Processing method in the middleware to integrate data occurring through the RFID and the WSN in a single environment and to interoperate the events based on the EPC global network. However, as the EPC Sensor Network technology continuously performs its operation even in the case that the minimum conditions are not to be met to find complex events in the middleware, its operation cost rises. Therefore, to address the problems of the existing system, we defined the minimum conditions of the complex events to detect unnecessary complex events in the middleware, and proposed an algorithm that can extract complex events only when the minimum conditions are to be met. To examine the minimum conditions, a index and a query index are used to extract complex events. To evaluate the performance of the proposed methods, In the case of the method of extracting complex events based on a bitmap index, we used the existing extraction method and NS2 simulation to evaluate its performance and thus to show its good performance in terms of the number of operation and the processing time for the complex events.

• Journal of KIISE:Computing Practices and Letters
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• v.16 no.12
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• pp.1244-1248
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• 2010

The previous study of Digital Broadcasting Recommendation system is based on user explicit profiling information. But user profile is always changing and the exact extraction of user profile is very important in recommendation system like Digital TV using many user interactions. This paper is studied of realtime user profiles aggregation through user remote controller input and matching this profiles with contents meta-data like contents genre information, event information, content viewing time. It is not used commercial database system and network communication solution considering embedded system hardware restriction. And it is considered people want different content genre based on watching time. From the results of this paper, there are improvement of user satisfaction of contents recommendation.

• The Journal of Society for e-Business Studies
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• v.9 no.2
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• pp.109-121
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• 2004

In this paper, we propose a system that generates a new customizing information for customer with classification and analysis in detail and provides customized information to individual customers automatically. A proposed system generate preference information and preference e-mail format as analysis and calculate that e-mail open rate and mouse event information. Using generated interesting information and preference e-mail format, individual customer's interest information according to e-mail standard and format that customer prefers through agent automatically recompose and push to customer. From experiment, the designed and implemented system showed high e-mail open ratio and user's satisfaction in performance assessment.

• Journal of Information Technology Services
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• v.6 no.3
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• pp.163-177
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• 2007

This research is the concept of a game addiction absorbed in the game based on the review and analysis of factors that affect the characteristics of game addiction, it is appropriate to extract the purpose of factors. Game addiction factor is composed of a total of 32 questions, and a total of 356 people, to collect data through surveys. Factor analysis of the collected data to the target as a result of physical and mental problems, loss of control, tolerance, and avoidance of real world consists of three sub-factors. Factors that affect flow of tolerance and loss of control, and avoid the real world, including two sub-factors that could determine. Diagnostic game addiction factor in the reliability coefficients (Cronbach alpha) is a robust .966 aspects in the event. The game addiction scale score of 90-game addiction by category 'regular user', 90 points and 114 between the terms 'potentially dangerous user' and 13 percent of the overall. Finally, more than 115 points in the 'high-risk user' has been classified as 5% of the overall distribution of the notice that. Such factors extract game is a game addict, addicted users of the game and tend to properly evaluate and navigate game addiction-related problems early in the game addiction and found it could be used properly.

• Journal of Korean Society of Water and Wastewater
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• v.28 no.6
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• pp.635-645
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• 2014

The changes of rainfall pattern and impervious covers have increased disaster risks in urbanized areas. Impervious covers such as roads and building roofs have been dramatically increased. So, it is falling the ability safety of flood defense equipments to exist. Runoff coefficient means ratio of runoff by whole rainfall which is able to directly contribute at surface runoff during rainfall event. The application of accurate runoff coefficients is very important in sewer pipelines design. This study has been performed to estimate runoff characteristics change which are applicable to the process of sewer pipelines design or various public facilities design. It has used the SHER model, a long-term runoff model, to analyze the impact of a rising impervious covers on runoff coefficient change. It thus analyzed the long-term runoff to analyze rainfall basins extraction. Consequently, it was found that impervious surfaces could be a important factor for urban flood control. We could suggest the application of accurate runoff coefficients in accordance to the land Impervious covers. The average increase rates of runoff coefficients increased 0.011 for 1% increase of impervious covers. By having the application of the results, we could improve plans for facilities design.

• Journal of Korea Foundry Society
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• v.17 no.3
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• pp.276-285
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• 1997

The effect of wheel surface condition on solidification behavior of Al-Cu ribbon was investigated in order to establish extreme levels of heat extraction. The condition of wheel surface was changed either by heating the wheel surface up to $200^{\circ}C$ or by coating boron nitride(BN) onto the the rim of a wheel. Heating the wheel surface up to $200^{\circ}C$ improved the wetting behavior between the molten metal and the rotating wheel, leading to an increase in the ratio of columnar structure to the entire thickness of Al-4.3wt%Cu and Al-33.2wt%Cu ribbons. For Al-4.3wt%Cu ribbon, assuming one grain as a single heterogeneous nucleation event at the contact point, the nucleation density with the wheel surface heated to $200^{\circ}C$, was $4{\times}10^6/mm^2$, and in the cases of BN coating with thin and thick layers, $10^5/mm^2$ and $5{\times}10^4/mm^2$, respectively. The largest cooling capacity of the wheel corresponded to the heated wheel surface, and as the thickness of BN coating layer increased, the cooling capacity of the wheel gradually decreased.

• Annual Conference on Human and Language Technology
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• 2009.10a
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• pp.130-135
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• 2009

정보추출(information extraction), 질의-응답 시스템(Question-Answering system) 등의 자연언어처리 응용분야에서 시간과 사건에 관련한 정보를 추출하는 것은 중요한 부분이다. 그럼에도 불구하고, 한국어의 자연언어처리 응용분야에서는 아직까지 이 연구가 본격화되지 않았다. 미국 TARSQI 프로젝트의 연구결과를 바탕으로 하여 한국어 텍스트에서 시간 및 사건 표현의 주석, 추출, 추론을 위한 명세 언어(KTimeML), 주석 말뭉치(KTimeBank), 자동 태깅 시스템(KTarsqi Toolkit: KTTK)의 개발을 목표로 2008년 KTARSQI 프로젝트가 시작되었다. 이 논문에서는 KTARSQI 프로젝트의 목표와 과제에 대한 전반적인 소개와 함께, 현재까지 진행된 작업의 결과로서 사건 태그의 명세와 주석에 관한 논의를 덧붙인다.

• Journal of the Korean Society of Hazard Mitigation
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• v.8 no.2
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• pp.149-158
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• 2008

The parameters of each basin, required for the accurate analysis of flood runoff using Storage Function Model, are estimated. Prior to the estimation, sensitivity analysis and extraction of new regional topographic factors for Han River basin are conducted. Based on the result, the outflow constant of basin model is calculated through regression analysis in relation with pre-flood runoff depth. The storage constant of basin model is derived by the optimum storage constant equation, according to the flood event of each basin. The model using the mentioned parameters was compared with K-Water model of Korea Water Resources Corporation and the model of Han River Flood Control Office, and proved to correspond to the observed hydrograph more.