• Journal of Power Electronics
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• v.11 no.4
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• pp.576-582
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• 2011

This paper presents a novel control strategy for selective compensation of power quality (PQ) problems, depending upon the limited rating of voltage source inverters (VSIs), through a unified power quality conditioner (UPQC) in a three-phase four-wire distribution system. The UPQC is realized by the integration of series and shunt active power filters (APFs) sharing a common dc bus capacitor. The shunt APF is realized using a three-phase, four-leg voltage source inverter (VSI), while a three-leg VSI is employed for the series APF of the three-phase four-wire UPQC. The proposed control scheme for the shunt APF, decomposes the load current into harmonic components generated by consumer and distorted utility. In addition to this, the positive and negative sequence fundamental frequency active components, the reactive components and harmonic components of load currents are decomposed in synchronous reference frame (SRF). The control scheme of the shunt APF performs with priority based schemes, which respects the limited rating of the VSI. For voltage harmonic mitigation, a control scheme based on SRF theory is employed for the series APF of the UPQC. The performance of the proposed control scheme of the UPQC is validated through simulations using MATLAB software with its Simulink and Power System Block set toolboxes.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.28 no.3A
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• pp.140-150
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• 2003

In this paper, we propose a novel code sharing method for downlink transmission of mobile satellite communication systems using a multibeam geosynchronous-orbit satellite. In the proposed system, spreading codes are shared among downlink beams in order to increase the system capacity. We also propose efficient radio resource and transmit power allocation schemes for the proposed system. Simplified analysis and simulation results on the system capacity show the capacity improvement by the proposed scheme. The simulation results show that the capacity of the proposed system is more than 2 times as large as that of a conventional multibeam satellite system. In the frequency-selective fading channel, the capacity improvement increases as the interference between orthogonal spreading codes decrease.

• International journal of advanced smart convergence
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• v.10 no.4
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• pp.66-71
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• 2021

In this paper, we sought ways to accept and reject advertisements using the function of a smartphone gyro sensor to enable selective transmission and reception of YouTube advertisements by linking the gyro function of mobile phones. In the case of YouTube advertisements, the skip button is activated after the advertisement is played for a certain period of time (about 5 seconds) before and after the video is played. During the time the advertisement is maintained, it can be used to achieve various goals such as increased website traffic, brand awareness, and sales induction. Since this type of advertisement is not a setting in which the transition takes place immediately, it can be seen as the most suitable setting to strengthen brand awareness. However, due to the nature of the YouTube advertising system, it is often discarded through users' skipping behavior in the process of sharing and reproducing information. Therefore, in this paper, we implemented an optional advertisement transmission system that applies the principle of gyroscope to minimize wasted advertisements and selectively maintain desired advertisements in consideration of the transmission and reception aspects of advertisement broadcasts. It measures rotational repulsive force with directional stability and car wash characteristics, and uses algorithms to identify the slope and angular speed of mobile phones to ensure that advertisements are transmitted and received. Through this, it is expected that advertisement transmission can be performed on the side of an advertisement provider, and selective advertisement reception can be performed on the side of a user.

• International journal of advanced smart convergence
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• v.9 no.3
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• pp.141-144
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• 2020

Iterative decision feedback equalizer (IDFE) is a recursive equalization technique that can help to achieve an additional performance gain for the system by combining iterative channel decoding and interference cancellation. In a single carrier-based system, the intersymbol interference (ISI) is a critical problem that must be resolved since it causes frequency selective fading. Based on the idea of sharing the estimated information in the process of iteration, IDFE is considered as an efficient solution to improve the robustness of the system performance on the ISI channel. In this paper, the IDFE is applied on single carrier FDMA (SC-FDMA) system to evaluate the performance under ISI channel. The simulation results illustrate that IDFE helps to improve the performance of the SC-FDMA system, especially with long delay spread channels.

• 한국HCI학회:학술대회논문집
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• 2007.02a
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• pp.598-605
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• 2007

본 논문에서는 지능형 정보 공간에서의 모바일 증강 현실 기반 환경 제어, u-콘텐츠의 개인화, 선택적 공유 및 협업의 개념을 포함하는 맥락 인식 모바일 증강 현실 (Context-aware Mobile AR) 시스템을 제안한다. 유비쿼터스 컴퓨팅 인프라의 발전으로 눈에 보이지 않는 컴퓨팅 리소스들로부터 획득되는 환경 및 개인의 맥락정보와 u-콘텐츠 활용의 용이성이 증가하고 있다. 하지만 사용자들이 눈에 보이지 않는 수많은 스마트 오브젝트들을 인지하기가 어려우며, 인터페이스의 복잡성으로 인하여 스마트 오브젝트들을 제어하는 것 역시 쉽지 않다. 또한, 다양한 u-콘텐츠의 획일적인 증강은 사용자에게 혼란만을 가중시키는 문제를 유발한다. 따라서, 제안된 시스템은 맥락 인지 기술과 모바일 증강 현실 기술을 접목하여 개인화된 스마트 오브젝트 컨트롤과 개인화된 u-콘텐츠의 증강 및 선택적인 공유를 가능하게 하고자 한다.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2022.06a
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• pp.197-198
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• 2022

Versatile Video Coding (VVC)는 차세대 동영상 압축 표준화 과정에서 다수의 부호화 기술을 새롭게 채택하였는데, 이중 Multiple Reference Lines (MRL)을 포함한 일부 기술은 휘도 채널에만 적용될 수 있으며 색차 성분에 대해서는 적용이 고려되지 않는다. 본 논문은 VVC 에서 휘도 채널에만 적용되는 MRL 기술을 색차 채널로 확장하기 위하여, DM(Derived Mode)을 사용하는 색차 블록의 대응 휘도 블록이 MRL 을 사용하는 경우에 해당 참조 라인을 선택적으로 공유하여 색차 블록이 화면 내 예측에 복수개의 참조 라인을 고려하여 선택할 수 있도록 하는 방법을 제안한다. 실험 결과, VVC Test Model (VTM) 15.0 대비 Cb, Cr 성분 각각 -0.09%, -0.05%의 성능 향상을 보인다.

• Composites Research
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• v.19 no.3
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• pp.23-28
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• 2006

Carbon nanotubes reinforced copper matrix laminated nanocomposites were developed and the mechanical properties were evaluated by using micro-tensile testing system. Sandwich-type laminated structure constituted with carbon nanotube layers as a reinforcement and electroplated copper matrix were fabricated by a new processing approach based on selective dip-coating of carbon nanotubes. The mechanical properties of nanocomposites were improved due to an enhanced load sharing capacity of carbon nanotubes homogeneously distributed within the in-plane direction, as well as a bridging effect of carbon nanotubes along the out-of-plane direction between the upper and lower matrices. The universality of the layering approach is applicable to a wide range of functional materials, and here we demonstrate its potential use in reinforcing composite materials.

• Journal of the Korean Society for information Management
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• v.33 no.1
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• pp.293-316
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• 2016

This study aims to improve bibliographic data of public libraries by linking service data, which are produced out of library service programs. Service data collected from the seven award-winning public libraries were selected and analyzed. A Bibliographic Framework is used for linking bibliographic data and service data. Interfaces are also suggested for the two-way data linking. The results can be used to obtain 1) selective and value-added bibliographic data, 2) bibliographic data updated continuously throughout the lifecycle, 3) structured service data for preservation and sharing, and 4) bibliographic data linked to the additional external linked data.

• The Journal of Korean Academic Society of Nursing Education
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• v.7 no.2
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• pp.207-216
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• 2001

To understand the types of interactions between the nurses' college students and patients, this research used Spradley's Cultural Description Method to carry out his eleven- stage research conduct process : participatory observation, cultural description recording, descriptive observation, category analysis, focus observation, classification analysis, selective observation, components analysis, cultural themes, cultural discovery, and cultural description writing. The research participants were 7 nurses' college students practising at the hospital affiliated to E university, and data were collected from May 2000 through primary and secondary in-depth interviews and observations. The cultural characteristics of the subjects extracted from these results were as follows : 1. The students learned through contacts with patients. 2. The students experienced "Sharing" through interactions with patients. 3. The students showed evasive behaviors in difficult situations. 4. The students paltered when faced with difficult situations. 5. The students did not surrender to the refusals of patients. 6. The students identified their studentship. 7. The students regarded human interaction as 'contact'.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.47 no.12
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• pp.1-7
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• 2010

In this paper, the technique for obtaining diversity gain without increasing the antenna is proposed using symbol share in the OFDM systems. Proposed technique groups symbols which are mapped into different sub-carriers and these symbols are modulated by proposed constellation. Proposed constellation has the identical minimum distance with QPSK modulation constellation and obtain more frequency diversity gain. Also, proposed modulation scheme make it possible to increase data rate using subcarriers allocated symbols.