• Journal of Korean Society of Coastal and Ocean Engineers
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• v.20 no.6
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• pp.540-552
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• 2008

We predicted to seasonal sediment transport pathway of the estuary area of the Nakdong river using the STA method. The eCSedtrend model was used to flexible application of the previous STA methods. The analysis of the seasonal interpretation of sediment transport pathway showed that the most dominant trend in the Nakdong estuary was CB+ and CB-. In case of CB+, it was identified around the area where the mud sediment was distributed and formed transport vector toward the north. Also, in case of CB-, it was identified mostly around the sand bar where the sand sediment was distributed and generally showed transport vector toward the north even though there was seasonal difference.

• Journal of Broadcast Engineering
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• v.26 no.2
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• pp.197-207
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• 2021

The emergency alert broadcast service based on cellular communications is defined as CBS. However, the CBS just supports a limited text message, which might be unavailable to foreigners, who are unfamiliar with local characters. The CBS protocol relies on a broadcast mechanism. Such a broadcast technology exhibits that the number of outage users significantly increases under poor channel conditions. In this paper, we present a supplementary service technology for 5G CBS, which considerably enhances the accessibility of foreigners and illiterate persons, and the receiver performance. For the enhanced receiver performance, the proposed supplementary service approach effectively exploits the device-based geo-targeting capability that the 5G CBS can afford to offer.

• Proceedings of the Korea Information Processing Society Conference
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• 2016.10a
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• pp.363-366
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• 2016

추천 기법은 개인의 관심사와 상황을 고려한 개인화된 아이템을 제공함으로써 아이템의 소비과정에서 발생하는 부하를 줄여주고 정보 소비의 효율성을 증대시키는데 중요한 역할을 한다. 본 연구에서는 전통적인 추천 기법인 Content-Based(CB)기법과 최근 온라인 소셜 네트워크의 경향을 반영한 Social Network-based(SN)기법을 접목하여 새로운 복합방식의 정보 추천 기법을 제시한다. CB 기법의 대표적인 한계점인 cold start problem과 SN 기법의 추천 아이템의 전문성 문제를 상호 보완하며, 특히 최근 소셜 네트워크의 특징인 비신뢰 (non-trust) 기반의 영향력 있는 정보 확산자가 존재하는 환경에서 기법을 적용할 수 있도록 하였다. 또한 대부분 사람 추천 중심인 기존의 SN 기법들과는 달리 사람에게 제공할 정보의 추천에 초점을 두며, 정보 선정과정에서 개인의 온라인과 현실(real world)에서의 사회 활동 정보를 모두 활용하여 더육 더 개인화된 가치 정보를 제공하고자 한다.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2002.11a
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• pp.156-160
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• 2002

In this paper, we have estimated by means of the theoretical analysis and the simulation of FCA(Fixed Channel Assignment) and CB(Channel Borrowing) in order to consider the CB as a technique to meet ducting interference from adjacent countries. Also, we assumed that the receiving power level of ducting interference with time rate can be characterized by the normal distribution due to the previous measured results, and the ducting interferences which are exceeding the reference power level can be regarded as calls. These calls can be processed by CR assignment and by which sharing channels between cells brings to us the method of meeting the ducting interference to use spectrum resources effectively. However, the spectrum frequency reusing and the interference effects between channels should be considered in CB simulation in the future.

• Journal of the Korea Society for Simulation
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• v.30 no.2
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• pp.49-64
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• 2021

M&S techniques are widely used as scientific means to systematically develop response plans to chemical and biological (CB) hazards. However, while the theoretical area of hazard dispersion modeling has achieved remarkable practical results, the operational analysis area to simulate CB hazard response plans is still in an early stage. This paper presents a model to simulate CB hazard response plans such as detection, protection, and decontamination. First, we present a possible way to display high-fidelity hazard dispersion in a combat simulation model, taking into account weather and terrain conditions. We then develop an improved vulnerability model of the combat simulation model, in order to simulate CB damage of combat simulation entities based on other casualty prediction techniques. In addition, we implement tactical behavior task models that simulate CB hazard response plans such as detection, reconnaissance, protection, and decontamination. Finally, we explore its feasibility by analyzing contamination detection effects by distributed CB detectors and decontamination effects according to the size of the {contaminated, decontamination} unit. We expect that the proposed model will be partially utilized in disaster prevention and simulation training area as well as analysis of combat effectiveness analysis of CB protection system and its operational concepts in the military area.

• Journal of the Korea Institute of Military Science and Technology
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• v.14 no.5
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• pp.880-887
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• 2011

The Wireless Mesh Network(WMN) technology is able to provide an infrastructure for isolated islands, in which it is difficult to install cables or wide area such as battlefield. Therefore, WMN is frequently used to satisfy needs for internet connection and active studies and research on them are in progress. However, as a result of increase in number of hops under hop-by-hop communication environment has caused a significant decrease in throughput and an increase in delay. Considering the heavy traffic of real-time data, such as voice or moving pictures to adaptive WMN, in a military environment. Such phenomenon might cause an issue in fairness index. In order to resolve this issue, we proposed a Cluster Based Multi-channel Assignment Scheme(CB-MAS) for adaptive tactical wireless mesh network. In the CB-MAS, the communication between the Cluster-Head(CH) and cluster number nodes uses a channel has no effect on channels being used by the inter-CH links. Therefore, the CB-MAS can minimize the interference within multi-channel environments. Our Simulation results showed that CB-MAS achieves improved the throughput and fairness index in WMN.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.36 no.9A
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• pp.784-789
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• 2011

In this paper, a precoder based on limited phase feedback is proposed to maximize user's receive signal-to-interference-plus-noise ratio (SINR) in coordinated multi-point (CoMP) coordinated scheduling / coordinated beamforming (CS/CB) precoding matrix indicator (PMI) scenario. Most conventional precoding techniques based on limited phase feedback have been considered in a single-cell environment. However, considering neighboring cells in a multi-cell environment, we enhance the conventional preocoding. method. First, to maximize receive SINR, precoding matrices are designed to maximize the serving cell's signal and to minimize the coordinated cells' signal. Also, a precoder which can be used in a limited bit feedback condition is suggested. Finally, the proposed precoder's performance is evaluated and compared with some other precoding techniques by using simulation under the CoMP CS/CB PMI scenario.

• KIISE Transactions on Computing Practices
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• v.21 no.1
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• pp.82-87
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• 2015

There are many current researches that are looking to improve the quality of HTTP adaptive streaming services. However, the existing schemes have a serious problem of QoE (Quality of Experience) degradation because few consider VBR video transmission. To cope with this problem, in this paper, we proposed a novel media quality adaptation scheme called CB-DASH (Content and Buffer-aware DASH). The proposed scheme controlled the video quality considering the VBR characteristics of video and the client's buffer state. Through the simulation, we proved that our scheme accomplished a more accurate estimated bandwidth than the conventional DASH and improved the QoE of streaming service.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.37A no.12
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• pp.1076-1084
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• 2012

In the CS/CB(Coordinated Scheduling/Beamforming) scheme, the cell edge user throughput is increased by selecting MIMO (Multiple Input Multiple Output) precoders which can minimize the interferences from adjacent base stations (BSs). However, in current LTE(Long Term Evolution) systems, the serving cell is selected in the initialization stage by using the synchronization signals and cell specific reference signals transmitted by adjacent BSs with a single antenna. The selected BS in the initialization stage may not be the best one since the MIMO precoding gain has not been considered in the cell selection stage. In this paper, a new cell selection technique is proposed for LTE systems with MIMO precoder by taking into account the effect of the precoder in the initialization stage. The proposed technique enables a user equipment (UE) in the cell boundary to select the serving BS by using the information (channel rank, effective channel capacity, and effective SINR(Signal to Interference plus Noise Ratio)) acquired from cell specific reference signals of candidate BSs. It is verified by computer simulation that the proposed technique can increase the channel capacity significantly in the multi-cell environments, compared with the conventional CS/CB scheme.

• Journal of Broadcast Engineering
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• v.26 no.5
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• pp.592-598
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• 2021

Current cellular systems rely on a CBS protocol for emergency alert broadcast services. However, the CBS protocol just specifies the delivery of a limited text message. Therefore, foreigners, who are unfamiliar with local characters, may have some difficulties in understanding the received CBS text message. The CBS protocol also reveals a distinct restriction in delivering abundant information because of a limited number of text characters. In order to overcome the weak points of the current CBS protocol, we propose a display method of image information and URL on the screens of mobile terminals for the received CBS text message in this paper. The presented approach effectively utilizes the message structure of CBS for 5G cellular systems.