• The Journal of Korean Institute of Communications and Information Sciences
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• v.39C no.3
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• pp.282-288
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• 2014

Recently there have been much interest in the GPS antenna performance improvement. In this paper, we propose very small patch antenna for GPS band. The proposed antenna resonance frequency was adjusted using the ground plane and variable capacitor connected the frame. The fabricated antenna was used a FR4 substrate by considering the difficulty and economical efficiency. Antenna measurement results was obtained good characteristics of VSWR 1.2, the passive antenna gain -0.60 dBi, the active antenna gain of 29 dB in center frequency of 1575.42 MHz GPS band.

• Social Workers
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• no.7 s.51
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• pp.38-41
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• 2006

이번 두 기관 방문은 ‘SK와 함께하는 행복한 일자리지원센터’의 영국 국제연수의 일환으로 이루어졌다. 연수팀은(사) 부스러기사랑나눔회 행복한 일자리지원센터와 SK 사회공헌팀으로 구성되어 있었으며, 허인영 사무국장 외 8인으로 이루어져 있었다. 이번 연수는 영굴에서 학령기 아동에 대한 지역사회 아동보호 및 방과 후 보호. 교육을 탐방하고 우리나라 상황에 적용 가능한 사회적 기업 모델을 모색하는 데 그 목적을 두고 있었다. 필자는 이번 연수팀의 두 기관 방문에 동행하며 통역과 소개를 하는 역할을 맡게 되었다. 연수팀이 방문하기 전 이미 방문할 기관에 대한 사전접촉은 마쳐있는 상태였다. 우선 BAND(Bistol Association for Neighbourhood Daycare Ltd)라는 곳을 먼저 접촉한 후 그 기관을 통하여 CCK 방과후클럽(Cabet Cool Kics After School Club)을 소개받게 되었다. 두 기관이 가까운 거리에 위치해 있는 관계로 하루에 두 기관 모두 방문할 수 있었으며 방문은 지난 4월 26일에 이루어졌다.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.40 no.2
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• pp.369-371
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• 2015

In this letter, we analyze the outage performance of the signal-to-noise ratio (SNR)-based selective relaying in a relay network, where the relay terminal may retransmit the received signal or remain silent based on the received SNR of the link from the source to the relay. For the proposed relaying scheme, we derive the exact outage probability.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.41 no.6
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• pp.628-630
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• 2016

Compressive sensing can recover an original sparse signal from a few measurements. Its performance is affected by the number of non-zero elements in the signal. The knowledge of partial locations of non-zero elements can improve the recovery performance. In this paper, we apply the partial location knowledge to the multipath matching pursuit. The numerical results show it improves the signal recovery performance and the channel estimation performance in the ITU-VB channel.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.40 no.1
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• pp.16-22
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• 2015

This paper proposes a power allocation method for multiple node beamforming with uniform circular array antennas to increase SIR of nodes in wireless mesh network. The proposed method calculates beamforming power allocation vectors that maximizes SIR satisfied with power constraint of HPA. The simulation results demonstrate the proposed method achieves the enhanced SIR of nodes than that of beamforming method.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.40 no.2
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• pp.310-312
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• 2015

In this paper, we propose an SIM/SM system with a square-law combining. In an outdoor environment, the performance of SIM/SM deteriorates due to an atmospheric turbulence. The square-law combining technique can enhance the performance of the SIM/SM by employing square-and-integrate operation at the receiver side. For various spectral efficiencies, the performance gain increases as the number of photodetectors increases. Furthermore, as the turbulence strength increases, the performance gain also increases.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.40 no.2
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• pp.307-309
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• 2015

In this letter, a DFT-based channel estimator is proposed for the uplink of LTE-A systems to solve the leakage and enhance the spectral efficiency. It is confirmed that the proposed estimator can significantly improve user and cell spectral efficiencies compared to conventional estimators.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.40 no.1
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• pp.132-141
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• 2015

There might have been weakness in securing user authentication or verification with real time service approach, while existing unimodal biometric authentication has been used mainly for user identification and recognition. Accordingly, it is essential to research and develop ways that upgrade security performance with multi biometric based real time authentication and verification technology. This paper focused to suggest binding assignment and strategy for developing multi biometric authentication technology through investigation of advanced study and patents. Description includes introduction, technology outline, technology trend, patent analysis, and conclusion.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.40 no.2
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• pp.408-418
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• 2015

Virtualizing The Physical Devices And Resources As Well As Conceptual Entities Would Form Vos And Cvos, Which Provides Dynamicity And Intelligence Through Composition And Collaboration For Emergency Services In WoO Based Smart Shopping Mall (WSSM). Semantic Ontology In WoO Platform Supports Dynamic Composition And Collaboration Among Objects, VOs And CVOs To Provide Intelligent Services. This Paper Proposes An Architectural Model Of WoO Platform To Support The Smart Emergency Services In Shopping Mall. A Semantic Ontology Model For Wssm, And Information Reusability And Interoperability Among The Vos And Their Functional Models Have Been Presented.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.40 no.1
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• pp.58-60
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• 2015

In this letter, an open-loop precoding is proposed to enhance the performance of SM in transmit correlated MIMO channels. The proposed method is derived by observing the effect of feedback error on the minimum distance precoder, and can mitigate the performance degradation without any feedback information.