• 한국정보통신설비학회:학술대회논문집
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• 한국정보통신설비학회 2006년도 하계학술대회
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• pp.47-52
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• 2006

In this paper, we suggested new network architecture to provide seamless service between the cellular system and new wireless broadband network such as IEEE 802.16e, called WiBro. The interworking technologies are very important issue because mobile operator should provide service connectivity between various wireless networks based on different access technologies. Moreover a change and modification on legacy network should be minimized for providing interworking with new wireless broad-band network. We implemented proposed interworking architecture between 3G cellular network and 802.16e network to provide seamless service including interworking unit in real test environment. Also, we performed performance evaluation in hybrid network environments.

• International Journal of Computer Science & Network Security
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• 제22권2호
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• pp.290-296
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• 2022

Big Data is a data analysis technology empowered by late advances in innovations and engineering. In any case, big data involves a colossal responsibility of equipment and handling assets, making reception expenses of big data innovation restrictive to little and medium estimated organizations. Cloud computing offers the guarantee of big data execution to little and medium measured organizations. Big Data preparing is performed through a programming worldview known as MapReduce. Normally, execution of the MapReduce worldview requires organized joined stockpiling and equal preparing. The computing needs of MapReduce writing computer programs are frequently past what little and medium measured business can submit. Cloud computing is on-request network admittance to computing assets, given by an external element. Normal arrangement models for cloud computing incorporate platform as a service (PaaS), software as a service (SaaS), framework as a service (IaaS), and equipment as a service (HaaS).

• 한국콘텐츠학회:학술대회논문집
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• 한국콘텐츠학회 2014년도 춘계 종합학술대회 논문집
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• pp.353-354
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• 2014

• 식물분류학회지
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• 제53권2호
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• pp.126-147
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• 2023

녹보리똥나무와 큰보리장나무는 형태적 특성에 기반하여 잡종 분류군으로 제안된 바 있으나, 이에 대한 분류학적 실체가 불명확하다. 본 연구에서는 녹보리똥나무와 큰보리장나무의 잡종 기원을 밝히기 위하여 현장 조사와 표본관에 소장된 표본을 검토하여 형태적 특징을 관찰하였으며, 핵리보솜 구간(internal transcribed spacer, 5S non-transcribed spacer)과 엽록체 구간(matK)의 염기서열을 비교·분석하였다. 형태적 특징을 관찰한 결과, 녹보리똥나무는 보리장나무와, 큰보리똥나무는 통영볼레나무와 형태적으로 유사성을 보였으나, 분자 분석 결과, 녹보리똥나무는 핵리보솜 구간에서 보리장나무와 보리밥나무의 서열의 혼성화가 관찰되었다. 큰보리장나무는 다양한 양상이 관찰되었는데, 일부 개체는 핵리보솜 구간에서 통영볼레나무와 보리밥나무의 서열의 혼성화가, 엽록체 구간에서는 보리밥나무 서열이 관찰되었다. 다른 개체는 핵리보솜 구간에서는 보리밥나무의 서열을 보였으나, 엽록체 구간에서는 통영볼레나무의 서열이 관찰되어 핵과 엽록체간 불일치를 보였다. 일부 개체는 통영볼레나무와 보리밥나무의 중간형을 보였으나, 핵리보솜과 엽록체 구간 모두 보리밥나무 서열이 관찰되었다. 이러한 결과는 두 종이 잡종기원이며, 부모종 또는 잡종 개체간 교배가 빈번히 일어나는 것을 시사한다.

• ETRI Journal
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• 제38권3호
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• pp.579-588
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• 2016

To improve the ability to determine a vehicle's movement information even in a challenging environment, a hybrid approach called non-Gaussian square rootunscented particle filtering (nGSR-UPF) is presented. This approach combines a square root-unscented Kalman filter (SR-UKF) and a particle filter (PF) to determinate the vehicle state where measurement noises are taken as a finite Gaussian kernel mixture and are approximated using a sparse Gaussian kernel density estimation method. During an outage-free GPS period, the updated mean and covariance, computed using SR-UKF, are estimated based on a GPS observation update. During a complete GPS outage, nGSR-UPF operates in prediction mode. Indeed, because the inertial sensors used suffer from a large drift in this case, SR-UKF-based importance density is then responsible for shifting the weighted particles toward the high-likelihood regions to improve the accuracy of the vehicle state. The proposed method is compared with some existing estimation methods and the experiment results prove that nGSR-UPF is the most accurate during both outage-free and complete-outage GPS periods.

• 한국통신학회논문지
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• 제33권7B호
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• pp.592-600
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• 2008

In this paper, a Hybrid Scaling based DTW (HS-DTW) mechanism is proposed for detection of periodic shrew TCP attacks. A low-rate TCP attack which is a type of shrew DoS (Denial of Service) attacks, was reported recently, but it is difficult to detect the attack using previous flooding DoS detection mechanisms. A pattern matching method with DTW (Dynamic Time Warping) as a type of defense mechanisms was shown to be reasonable method of detecting and defending against a periodic low-rate TCP attack in an input traffic link. This method, however, has the problem that a legitimate link may be misidentified as an attack link, if the threshold of the DTW value is not reasonable. In order to effectively discriminate between attack traffic and legitimate traffic, the difference between their DTW values should be large as possible. To increase the difference, we analyze a critical problem with a previous algorithm and introduce a scaling method that increases the difference between DTW values. Four kinds of scaling methods are considered and the standard deviation of the sampling data is adopted. We can select an appropriate scaling scheme according to the standard deviation of an input signal. This is why the HS-DTW increases the difference between DTW values of legitimate and attack traffic. The result is that the determination of the threshold value for discrimination is easier and the probability of mistaking legitimate traffic for an attack is dramatically reduced.

• 한국방송∙미디어공학회:학술대회논문집
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• 한국방송∙미디어공학회 2016년도 추계학술대회
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• pp.31-32
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• 2016

본 논문은 ATSC2.0 기반 8-VSB/MH 융합형 3DTV (A/104 Part 5 Service Compatible 3DTV using Main and Mobile Hybrid Delivery, A/104 part 5) 방식의 서비스 커버리지 및 음영지역을 예측할 수 있는 측정 및 분석시스템 개발에 대하여 기술 한다. ATSC2.0 기반 고정/이동 방송시스템은 8-VSB 로 전송되는 고정 TV 방송서비스(좌영상 전송)와 ATSC-MH 로 전송되는 in-band 모바일 방송서비스(우영상 전송)를 모두 수신하여 좌/우영상의 재생 및 동기화를 통해 융합형 3D 영상을 복원하게 된다. 따라서 융합형 3DTV 수신기는 고정 및 모바일 방송신호를 모두 수신하여야 융합형 3D 영상복원을 할 수 있으며, 방송사 입장에서 서비스 커버리지 측정을 하기위해서는 8-VSB 및 ATSC-MH 신호의 수신여부를 모두 측정하여야 한다. 본 논문에서는 이와 같은 RF 수신전계강도 파라미터 및 GPS 정보등을 실시간으로 모니터링하여, 시스템 사용자에가 융합형 3DTV 서비스 커버리지 측정 및 분석을 통해 서비스를 위한 RF 방송망 셀 구성 및 음영지역을 예측할 수 있는 ATSC2.0 융합형 3DTV 서비스 커버리지 분석기 구현에 대한 내용을 기술한다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제15권7호
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• pp.2399-2413
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• 2021

A recommendation system is an information filter tool, which uses the ratings and reviews of users to generate a personalized recommendation service for users. However, the cold-start problem of users and items is still a major research hotspot on service recommendations. To address this challenge, this paper proposes a high-efficient hybrid recommendation system based on Fuzzy C-Means (FCM) clustering and supervised learning models. The proposed recommendation method includes two aspects: on the one hand, FCM clustering technique has been applied to the item-based collaborative filtering framework to solve the cold start problem; on the other hand, the content information is integrated into the collaborative filtering. The algorithm constructs the user and item membership degree feature vector, and adopts the data representation form of the scoring matrix to the supervised learning algorithm, as well as by combining the subjective membership degree feature vector and the objective membership degree feature vector in a linear combination, the prediction accuracy is significantly improved on the public datasets with different sparsity. The efficiency of the proposed system is illustrated by conducting several experiments on MovieLens dataset.

• 한국컴퓨터정보학회논문지
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• 제14권6호
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• pp.125-134
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• 2009

웹을 통한 생물 데이터 접근 방식은 많은 과학자들에게 대화식으로 서로 다른 형식의 생물 데이터베이스 내용을 검색할 뿐만 아니라, 한 데이터베이스에서 다른 분자생물 데이터베이스로의 연결을 위한 강력한 도구를 제공한다. 본 논문에서의 생물 개념 모델은 생물 데이터 제어를 위한 4가지 통합 레이어를 기반으로 각 생물 데이터 소스 간의 연관성에 따른 규칙 속성을 적용하고 데이터 소스 중에 관심 대상이 되는 개체를 표현하여 하이브리드 생물 데이터 모델을 구성하였다. 특정 사용자의 응용 서비스 요구가 발생하면 해당 생물 데이터베이스와 웹 서비스를 통한 데이터 소스로부터 정보를 획득한다. 본 논문에서는 통합 레이어를 기반으로 웹 데이터 소스 상에서 정보를 탐색하기 위해 메타 규칙을 적용한 질의어 처리 모형과 수행구조를 정형화하였다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제12권11호
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• pp.5269-5286
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• 2018

Task scheduling is one of the key issues in improving system performance and optimizing resource management in cloud computing environment. In order to provide appropriate services for heterogeneous users, we propose a novel task scheduling strategy with service differentiation, in which the delay sensitive tasks are assigned to the rapid cloud with high-speed processing, whereas the fault sensitive tasks are assigned to the reliable cloud with service restoration. Considering that a user can receive service from either local SaaS (Software as a Service) servers or public IaaS (Infrastructure as a Service) cloud, we establish a hybrid queueing network based system model. With the assumption of Poisson arriving process, we analyze the system model in steady state. Moreover, we derive the performance measures in terms of average response time of the delay sensitive tasks and utilization of VMs (Virtual Machines) in reliable cloud. We provide experimental results to validate the proposed strategy and the system model. Furthermore, we investigate the Nash equilibrium behavior and the social optimization behavior of the delay sensitive tasks. Finally, we carry out an improved intelligent searching algorithm to obtain the optimal arrival rate of total tasks and present a pricing policy for the delay sensitive tasks.