• Journal of Communications and Networks
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• v.14 no.5
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• pp.540-545
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• 2012

In this paper, the lagged cross-correlation of two probability density functions constructed by kernel density estimation is proposed, and by maximizing the proposed function, adaptive filtering algorithms for supervised and unsupervised training are also introduced. From the results of simulation for blind equalization applications in multipath channels with impulsive and slowly varying direct current (DC) bias noise, it is observed that Gaussian kernel of the proposed algorithm cuts out the large errors due to impulsive noise, and the output affected by the DC bias noise can be effectively controlled by the lag ${\tau}$ intrinsically embedded in the proposed function.

• Journal of Communications and Networks
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• v.14 no.5
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• pp.495-500
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• 2012

A standard paradigm for the allocation of wireless resources in communication demands symmetry, whereby all users are assumed to be on equal footing and hence get equal shares of communication capabilities. However, there are situations in which "prime users" should be given higher priority, as for example in the transmission of emergency messages. In this paper, we examine a prioritization policy that can be implemented at the physical layer. In particular, we evaluate the performance of a prioritized transmission scheme based on spectrum pooling and on the assignment of higher signal-to-noise ratio channels to higher-priority users. This performance is compared to that of unprioritized (or "symmetric") schemes, and the impact of prioritization on the unprioritized users is discussed.

• Journal of Communications and Networks
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• v.14 no.5
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• pp.487-494
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• 2012

A standard paradigm for the allocation of wireless resources in communication demands symmetry, that is, all users are assumed to be on equal footing and hence get equal shares of the system's communication capabilities. However, there are situations in which "prime users" should be given priority, as for example in the transmission of emergency messages. We examine prioritization policies that could be implemented at the physical layer and propose a new one, termed interference priority (IP), which is shown to have excellent performance. We evaluate the performance of these prioritization techniques both in controlled settings and within the context of a full cellular system and discuss the impact of prioritized use of resources on the unprioritized users.

• Proceedings of the Korean Information Science Society Conference
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• 2005.07b
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• pp.856-858
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• 2005

음성인식 시스템에서 입력된 음성 데이터에 대해 비인식 대상을 거부하는 기능은 신뢰도 보장 측면에 있어서 상당히 중요하며, 신뢰도를 높이기 위해서는 단순한 인식기능 외에 부적절한 입력 패턴의 거부 기능이 필요하다. 본 논문에서는 이러한 신뢰성 문제를 해결하기 위하여 음소기반 인식 네트워크에서 필러 모델 방법과 단어 검출률 방법을 사용하여 실험하였고, 문장의 단어 수에 따른 두 방법의 문장 거부 성능을 FAR과 FRR의 평균을 최소화 하는 값을 각각 구함으로써 비교${\cdot}$분석 하였다. 그 결과 필러모델 방법이 좀 더 나은 거부 성능을 보였고, 단어 검출률을 이용하는 방법이 인식 네트워크를 전부 거치지 않아도 되므로 실행속도와 메모리 절약에서 효과적이었다.

• Proceedings of the Korean Information Science Society Conference
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• 2005.07a
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• pp.262-264
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• 2005

Radio Frequency Identification(RFID)시스템은 객체에 부착된 RFID 태그를 리더로 읽어 들여 정확하게 객체를 인식할 수 있어 상황 인지를 위한 중요한 정보를 제공할 수 있다. 그러나 태그와 리더간의 통신이 단일 홉으로 구성되어 있기 때문에 대상 지역의 전체를 인식하지 못하여, 상황인지를 위한 총체적 정보를 제공할 수 없는 문제를 가지고 있다. 본 논문에서는 최근 제안되고 있는 무선 센서 네트워크와 RFID 시스템의 결함을 통하여 RFID시스템이 대상 지역 전체를 인식할 수 있게 하고, 이 정보를 센서 네트워크의 센싱 정보와 함께 활용하여 지능적인 상황 인지가 가능한 RFID 기반 우선 센서네트워크의 지능적 상황 인지 지원 시스템을 제안한다. 제안된 시스템에서는 RFID 시스템의 객체 인지 능력을 활용할 수 있을 뿐만 아니라, RFID 시스템에 네트워킹 기능을 제공하여 지능적 상황인지를 가능하게 한다.

• Journal of Electrical Engineering and Technology
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• v.9 no.3
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• pp.1043-1050
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• 2014

Obsolescent control systems for power systems are evolving into intelligent systems and connecting with smart devices to give intelligence to the power systems. As networks of the control system are growing, vulnerability is also increasing. The communication network of distribution areas in the power system connects closely to vulnerable environments. Many cyber-attacks have been founded in the power system, and they could be more critical as the power system becomes more intelligent. From these environment, new communication network architecture and mitigation method against cyber-attacks are needed. Availability and Fault Tree analysis used to show that the proposed system enhances performance of current control systems.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.1 no.3
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• pp.119-125
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• 2008

This work involves analyzing partial discharge (PD), which has estimated the detected signal accumulation based on Labview, and analyzing by Fuzzy algorithm. In algorithm, we developed system configuration that detected accumulating PD signal. With practical PD logic implementation of theoretical detected system and hardware implementation, the device for 50kV setup has generated and then has applied with 15k~17kV with 1:1 time probe. Our new class of PD detected algorithm has also compared with PRPDA or Fuzzy algorithm, which has diagnose more conveniently by adding numerical values.

• Proceedings of the Korean Society for Quality Management Conference
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• 2006.04a
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• pp.114-119
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• 2006

Brand placement, or product placement(PPL) is one of alternative promotion means of the traditional advertising communication type, and its effectiveness is getting begger because of the increase of movies, video media, and TV networks. The product placement is a new type of advertising communication means that pays the price in the movies definitely. This study is a research on the effect of the product placement on the consumption behavior and brand image.

• Annual Conference of KIPS
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• 2018.05a
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• pp.57-59
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• 2018

무선 네트워크에서 토폴로지의 빈번한 변화로 노드 간 링크 단절과 경로재설정이 발생하여 네트워크 내에 제어메시지 과부하와 같은 문제점들이 발생한다. 본 연구에서는 링크 단절과 제어 메시지 과부하와 같은 문제점을 해결하기 위하여 무선 네트워크 환경에서 주변 노드 탐색과정, 경로 탐색과정, 경로관리과정의 3단계를 수행할 때 안정적인 전력, 높은 컴퓨팅 능력과 무선 신호 조절 능력이 있는 존 마스터(Zone Master)를 기반으로 하는 링크안정성 기법을 제안하였다. 제안한 기법은 다양한 무선 환경에서 기존의 OLSR라우팅 프로토콜보다 우수한 성능을 보임을 확인하였다.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.12 no.6
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• pp.1082-1086
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• 2008

Multiple-input multiple-output (MIMO) is an efficient technology to increase data rate in wireless networks due to bandwidth and power limitations. Data transmission rate between transmitter and receiver is determined by channel capacity. MIMO has an advantage of reliable communication over wireless channel because of utilizing the channel capacity properly. In this letter, we drive a new formula, closed form capacity formula, using confluent hypergeometric function.