• Journal of the Institute of Electronics Engineers of Korea TC
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• v.41 no.11
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• pp.9-15
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• 2004

We propose optimal interference rejection weight for multistage parallel nulling (MPN) partial parallel interference cancellation (PPIC) receiver previously proposed to enhance the performance of V-BLAST for downlink multiple-input multiple-output (MIMO) multicarrier (MC)-code division multiple access (CDMA) systems. MPN-PPIC method proposed in [1] was based on the parallel interference cancellation (PIC) with fixed interference rejection weight obtained experimentally. However, the fixed weight can not be adapted to various systems efficiently, thus we proposed method for the optimal interference rejection weight based on the received signal to interference and noise ratio (SINR), and the performance of the proposed method was evaluated through computer simulation comparing with the previous method. We obtained performance gains of 2.5 dB ~ 5 dB for BER of 10$^{-3}$ .

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.14 no.5
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• pp.489-498
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• 2003

Recently to introduce new services of ultra-high speed wireless access and systems beyond the 3rd generation mobile communication, 5 GHz band has been highly interested. As a way of getting the required frequency, it is considered that microwave relay bands below 6 GHz, which shows a slow decrease in demand and less cost-effectiveness, should be moved to other bands above 6 GHz. In this paper, as a tool for analyzing microwave link design and its service quality, the outage prediction based upon Vigants & Barnett＇s model is reviewed. To show outage and availability calculation, simulations are performed for the operating 4 GHz radio sites, and some results and features regarding frequency movement to 6.7 as well as 8 GHz are also discussed in terms of diversity techniques, bit error rate, and availability As the results, it is confirmed that only the diversity techniques of space or space and frequency can satisfy the annual objective of availability irrespective of frequency movement.

• Journal of the Institute of Convergence Signal Processing
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• v.11 no.4
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• pp.332-337
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• 2010

In this paper, we propose G-Robot framework implemented with the fusion technology called RITS(Robot Technology & Information Technology System) for robot control and remote monitoring using the mobile phone. In our implemented system, the mobile phone mounted on the robot controls the robot and sends the images to the mobile phone of the user. We can monitor surrounding area of the robot with mobile phone and control the movement of the robot by sending the data between mobile-phones. Also, if the predefined situation occurs to the robot, the mobile phone on the robot sends the data to the mobile-phone of the user. From the experimental result, we can conclude that it's possible to control the robot and monitor surrounding area of the robot in real time in the region where the 3G(Generation) communication is possible. In addition, we can control the robot using the bluetooth instead of the mobile phone communication if the robot is in visual range.

• The KIPS Transactions:PartB
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• v.13B no.5 s.108
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• pp.561-568
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• 2006

WPS(Wearable Personal Station) for next generation PC can define as a core terminal of 'Ubiquitous Computing' that include information processing and network function and overcome spatial limitation in acquisition of new information. As a way to acquire significant dynamic gesture data of user from haptic devices, traditional gesture recognizer based on desktop-PC using wire communication module has several restrictions such as conditionality on space, complexity between transmission mediums(cable elements), limitation of motion and incommodiousness on use. Accordingly, in this paper, in order to overcome these problems, we implement hand gesture recognition system using fuzzy algorithm and neural network for Post PC(the embedded-ubiquitous environment using blue-tooth module and WPS). Also, we propose most efficient and reasonable hand gesture recognition interface for Post PC through evaluation and analysis of performance about each gesture recognition system. The proposed gesture recognition system consists of three modules: 1) gesture input module that processes motion of dynamic hand to input data 2) Relational Database Management System(hereafter, RDBMS) module to segment significant gestures from input data and 3) 2 each different recognition modulo: fuzzy max-min and neural network recognition module to recognize significant gesture of continuous / dynamic gestures. Experimental result shows the average recognition rate of 98.8% in fuzzy min-nin module and 96.7% in neural network recognition module about significantly dynamic gestures.

• Convergence Security Journal
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• v.13 no.3
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• pp.25-31
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• 2013

Looking at the recent value change of users and the usage pattern of network users, it is changing from simple web information, one-way information acquisition and data transmission to increase of usage of multimedia, increasing demand for security and customization, and increasing demands for free mobility. Due to this change of demand, the services which were provided individually, developed into a form which is merged, the network also seems to develop into the combined network from the individual network for individual service, and the communication network control technology which is the core technology is also rapidly developing. To reflect the users' demands, the next generation network created the multi-layer network which is based on the WDM/IP transmission system and added the to make it easy to restructure. P-OTS (Packet-Optical Transport System) can be defined as a platform that combines SONET/SDH, Ethernet, DWDM, optical transport network (OTN) switching and reconfigurable optical add-drop multiplexers (ROADMs). In this paper, we suggested that the optimum path choice be performed through diversification of the PCE-based path selection using the information of various layers altogether in the multi-layer environment, compared with the established path selection method when the path was selected using the information of each layers.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.39 no.8
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• pp.14-25
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• 2002

In this paper, we propose a modified AFC algorithm which is suitable for the implementation of WCDMA reverse link receiver modem. To reduce the complexity, the modified CP-FDD algorithm named 'Normalized CP-FDD' is applied to the AFC loop. The proposed FDD algorithm overcomes the conventional CP-FDD's sensitivity to the variance of input signal amplitude and increases the linear range of S -curve. Therefore, offset frequency estimation using the proposed scheme can be more stable than the conventional method. Unlike IS-95, since pilot symbol in WCDMA is not transmitted continuously, we introduce a moving average filter at the FDD input to increase the number of cross-product. So, tracking speed and stability are improved. For more rapid frequency acquisition and tracking, we adopt a multi-stage tracking mode. Using NCO having ROM table structure, the frequency offset is compensated. We applied the proposed algorithm in the implementation of WCDMA base station modem successfully.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.11 no.2
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• pp.422-429
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• 2007

Location awareness is one of the key functionalities to build an U-city. Recently, many of works of the location-aware systems are emerging to commercially apply to on-going large-scale apartment complex based on U-city. As dwellers or cars being attached with active tags are moving in the U-city complex, the active tags periodically broadcast their own identifiers and receivers fixed along the street or in building use those information to calculate location of them. There are several issues to be considered for such an environment. The first is that the number of active tags operating in the same region are large as much as tens of thousands, and the second is that the active tags should be alive without change of batteries more than a year, hence low power consumption is very important. In this paper we propose i) a new architecture for location-aware system considering such issues, ii) technical issues to implement it using active tags, and iii) a mathematical analytic model to investigate overall performance and verify it by comparing with actual experimental results. Through the analysis we can show the theoretical boundary of the lowest packet loss rate and the maximum number of tags with acceptable performance for the systems based on active tags. The results can be applied to practical design of location-based systems of U-City projects.

• Journal of the Institute of Electronics and Information Engineers
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• v.53 no.5
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• pp.3-12
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• 2016

Recently, the study on 5G mobile communication systems using the millimeter-wave frequency band have been actively promoted and the importance of compensation of the nonlinearity of power amplifier caused by the characteristics of millimeter-wave frequency propagation attenuation is increasing. In the paper, we propose a piecewise polynomial model based on subdivision coefficient which are characteristics of power amplifier separated linear section and a non-linear section. In addition, the structure of digital predistortion based on the proposed model and direct learning method are proposed to implement a digital predistortion. To verify the proposed model, digital predistortion based on the proposed model and direct learning method for 60 GHz power amplifier using LTE signal implemented in the FPGA. And the hardware test bench measured performance and complexity. The proposed model achieves 3.3 dB gain over the single polynomial model in terms of the ACLR and reduces 7.5 percent in terms of the complexity.

• 한국공간정보시스템학회:학술대회논문집
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• 2002.03a
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• pp.83-88
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• 2002

최근 들어 무선인터넷 및 모바일 컴퓨팅 기술의 급속한 발전과 함께 향후 그 수요가 증대될 것으로 예상되는 분야가 위치기반 서비스(LBS: Location Based Service) 기술이다. 위치기반 서비스는 이동 통신을 통하여 사람 및 사물의 위치를 파악하고 이를 활용한 부가 응용 서비스로 국가 정보기술 인프라의 주요 영역을 점유하고 있는 GIS의 차세대 핵심 기술로 발전이 예상되는 분야이다[3][4]. 현재 3GPP나 3GPP2, OGC, LIF와 같은 여러 표준화 기구 및 산업체에서 위치기반 서비스와 이를 위한 시스템에 대한 연구가 진행중이며 위치기반 서비스를 위한 데이터 모델 표준화 연구는 거의 이루어지지 않고 있는 상황이다. 위치기반 서비스를 위한 데이터 표준화 모델은 이미 구축된 공간 데이터베이스의 재사용과 위치기반 서비스들간의 상호 운용성을 지원할 수 있어야 한다. 본 연구에서는 위치기반 서비스들 간의 상호 호환 및 통합을 가능하게 하고, 기존 공간데이터베이스와 연계하여 이 데이터를 위치기반 서비스에 활용하기 위한 공간 데이터 표준화 모델을 제안하고자 한다. 이를 위해 위치기반 서비스 표준화 사례를 조사하고, 위치기반 서비스를 위한 공간 데이터 모델을 제시하였다. 본 연구에서는 OpenLS의 위치기반 서비스를 기본서비스로 하고, OpenGIS의 공간 데이터 모델을 기반으로 네 가지 기본 위치 데이터 타입과 모델의 요구 사항을 포함하는 공간 데이터 표준모델을 개발하였다. 위치기반 공간 데이터 표준 모델은 위치기반 서비스와 데이터들과의 연계를 쉽게 하고, 위치기반 서비스들 간의 상호 운용성을 높이며, 기존 사용자 시스템의 수정 없이 인터페이스만을 추가함으로써 표준을 수용할 수 있다.\pm}153.2,\;116.1{\pm}94,\;29.4{\pm}30.3,\;45.1{\pm}44$로 Mel 10군과 Mel 30군이 유의적인 감소를 보였으나(p<0.05) 이들 두 군 간의 차이는 나타나지 않았다. 이상의 결과로, 랫트에서 복강수술 후 melatonin 10mg/kg투여가 복강 내 유착 방지에 효과적이라고 생각된다.-1}{\cdot}yr^{-1}$로서 두 생태계에 축적되었다.여한 3,5,7군에서 PUFA 함량이 증가한 반면, SFA 함량은 감소하여 P/S 비율, n-3P/n-6P 비율은 증가하는 경향이었으며 이는 간장의 인지질, 콜레스테롤 에스테르, 총 지질의 지방산조성에서도 같은 경향을 볼 수 있었다.X>$(C_{18:2})$와 n-3계 linolenic acid$(C_{18:3})$가 대부분을 차지하였다. 야생 돌복숭아 과육 중의 지방산 조성은 포화지방산이 16.74%, 단불포화지방산 17.51% 및 다불포화지방산이 65.73%의 함유 비율을 보였는데, 이 중 다불포화지방산인 n-6계 linoleic acid$(C_{18:2})$와 n-3계 linolenic acid$(C_{18:3})$가 지질 구성 총 지방산의 대부분을 차지하는 함유 비율을 나타내었다.했다. 하강하는 약 4일간의 기상변화가 자발성 기흉 발생에 영향을 미친다고 추론할 수 있었다. 향후 본 연구에서 추론된 기상변화와 기흉 발생과의 인과관계를 확인하고 좀 더 구체화하기 위한 연구가 필요할 것이다.게 이루어질 수 있을 것으로 기대된다.는 초과수익률이 상승하지만, 이후로는 감소하므로, 반전거래전략을 활용하는 경우 주식투자기간은 24개월

• Journal of Broadcast Engineering
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• v.22 no.6
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• pp.829-849
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• 2017

Due to the large-scale TV display, the convergence of broadcasting and broadband, and the advancement of signal compression and transmission technology, terrestrial digital broadcasting has evolved into UHD broadcasting capable of providing simultaneous broadcasting of fixed UHD and mobile HD. The Korean standard for terrestrial UHDTV broadcasting is based on ATSC 3.0, the broadcasting standard of North America. The terrestrial UHDTV broadcasting standard chose that as a new AV codec standard, HEVC video codec which can compress with higher efficiency compared to AVC, and MPEG-H 3D audio codec for realistic audio. Also, DASH and MMT are adopted as transmission format instead of MPEG-2 TS to support broadband as well as broadcasting network, and in order to provide 4K UHD/mobile HD service simultaneously ROUTE multiplexing technology is applied. In this paper, we propose an audio/video encoder, which is required to provide HDR/WCG supported high quality video service, 10.2 channel/4 object supporting stereo sound service, fixed UHD and mobile HD simultaneous broadcasting service based on ATSC3.0, also we implemented the ATSC 3.0 LDM system for ROUTE/DASH packager, multiplexing system and physical layer transmission/reception, and verified the service ability by applying it to real time broadcast environment.