• 한국대기환경학회:학술대회논문집
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• 한국대기환경학회 2003년도 춘계학술대회 논문집
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• pp.283-284
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• 2003

Cirrus cloud는 항상 지구대기의 20%정도를 덮고 있으며, 지구 복사수지와 기후변화에 영향을 미치며 그들의 미세물리학적이고 광학적인 특성에 따라 대기온도의 상승이나 냉각효과를 나타낸다. 일반적으로 적도지방에서는 가열효과를 지니고 중위도지방에서는 냉각효과를 지닌다(F.Nicolas et al, 1997). 이러한 중요성으로 외국에서는 Cirrus cloud에 대한 많은 연구(K. Sassen et al, 2001, C. M. R. Platt et al, 1998)가 이루어졌으나 국내에서는 관측 대상의 시간적ㆍ공간적 제약으로 연구가 거의 이루어지지 않고 있다. (중략)

• ETRI Journal
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• 제45권5호
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• pp.836-846
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• 2023

Mobile robots are used in modern life; however, object recognition is still insufficient to realize robot navigation in crowded environments. Mobile robots must rapidly and accurately recognize the movements and shapes of pedestrians to navigate safely in pedestrian-rich spaces. This study proposes real-time, accurate, three-dimensional (3D) multi-pedestrian detection and tracking using a 3D light detection and ranging (LiDAR) point cloud in crowded environments. The pedestrian detection quickly segments a sparse 3D point cloud into individual pedestrians using a lightweight convolutional autoencoder and connected-component algorithm. The multi-pedestrian tracking identifies the same pedestrians considering motion and appearance cues in continuing frames. In addition, it estimates pedestrians' dynamic movements with various patterns by adaptively mixing heterogeneous motion models. We evaluate the computational speed and accuracy of each module using the KITTI dataset. We demonstrate that our integrated system, which rapidly and accurately recognizes pedestrian movement and appearance using a sparse 3D LiDAR, is applicable for robot navigation in crowded spaces.

• 디지털융복합연구
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• 제10권10호
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• pp.465-473
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• 2012

모바일 기기와 클라우드 컴퓨팅 기술의 도입은 N 스크린 서비스와 같은 새로운 콘텐츠 서비스를 가능하게 하였다. 새로운 콘텐츠 서비스 환경을 위하여 상호운용성과 다중 플랫폼(multi-platform)을 지원하는 DRM(digital rights management) 기술들이 개발되고 있으나 아직까지 콘텐츠 서비스 가입 변경에 의한 콘텐츠의 이동이나 지원 단말의 구매 등 여러 면에서 사용자에게 불편함을 초래하고 있다. 본 논문에서는 가입 서비스와 상관없이 콘텐츠의 자유로운 이동을 지원하고 사용자가 소유한 다양한 스마트 기기에서 DRM이 적용된 콘텐츠를 자유롭게 사용할 수 있도록 클라우드 컴퓨팅 기반의 DRM 서비스 모델로써 DRMaaS(DRM-as-a-Service) 모델을 제안한다.

• 제어로봇시스템학회논문지
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• 제21권10호
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• pp.958-964
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• 2015

In this paper, an object recognition method based on the depth information from the RGB-D camera, Xtion, is proposed for an indoor mobile robot. First, the RANdom SAmple Consensus (RANSAC) algorithm is applied to the point cloud obtained from the RGB-D camera to detect and remove the floor points. Next, the removed point cloud is classified by the k-means clustering method as each object's point cloud, and the normal vector of each point is obtained by using the k-d tree search. The obtained normal vectors are classified by the trained multi-layer perceptron as 18 classes and used as features for object recognition. To distinguish an object from another object, the similarity between them is measured by using Levenshtein distance. To verify the effectiveness and feasibility of the proposed object recognition method, the experiments are carried out with several similar boxes.

• Journal of Multimedia Information System
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• 제7권2호
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• pp.125-136
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• 2020

Nowadays, cloud computing is becoming more popular among companies. However, the characteristics of cloud computing such as a virtualized environment, constantly changing, possible to modify easily and multi-tenancy with a distributed nature, it is difficult to perform attack detection with traditional tools. This work proposes a solution which aims to collect traffic packets data by using Flume and filter them with Spark Streaming so it is possible to only consider suspicious data related to HTTP Slow Rate Denial-of-Service attacks and reduce the data that will be stored in Hadoop Distributed File System for analysis with the FP-Growth algorithm. With the proposed system, we also aim to address the difficulties in attack detection in cloud environment, facilitating the data collection, reducing detection time and enabling an almost real-time attack detection.

• 대기
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• 제16권4호
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• pp.371-378
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• 2006

The surface observation probability system (SOPS) of the Korea Multi-Purpose Satellite (KOMPSAT) has been developed based on the climatological distribution of cloud coverage and the expected passage of satellite orbit. While the optical camera loaded on KOMPSAT series has been operated with the purpose of observing earth's surface, it cannot see the surface when an obstacle (i.e., cloud) exists between them. In the present study, cloud information of International Satellite Cloud Climatology Project incorporates into high resolution grid of the KOMPSAT-3 orbit. The characteristics of the KOMPSAT SOPS are discussed.

• Journal of Communications and Networks
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• 제15권4호
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• pp.398-406
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• 2013

In this paper, we investigate two types of in-phase and quadrature-phase (IQ) data transfer methods for cloud multiple-input multiple-output (MIMO) network operation. They are termed "after-precoding" and "before-precoding". We formulate a cloud massive MIMO operation problem that aims at selecting the best IQ data transfer method and transmission strategy (beamforming technique, the number of concurrently receiving users, the number of used antennas for transmission) to maximize the ergodic sum-rate under a limited capacity of the digital unit-radio unit link. Based on our proposed solution, the optimal numbers of users and antennas are simultaneously chosen. Numerical results confirm that the sum-rate gain is greater when adaptive "after/before-precoding" method is available than when only conventional "after-precoding" IQ-data transfer is available.

• Journal of Information Processing Systems
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• 제17권4호
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• pp.675-689
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• 2021

Nowadays, cloud computing is being adopted for more organizations. However, since cloud computing has a virtualized, volatile, scalable and multi-tenancy distributed nature, it is challenging task to perform attack detection in the cloud following conventional processes. This work proposes a solution which aims to collect web server logs by using Flume and filter them through Spark Streaming in order to only consider suspicious data or data related to denial-of-service attacks and reduce the data that will be stored in Hadoop Distributed File System for posterior analysis with the frequent pattern (FP)-Growth algorithm. With the proposed system, we can address some of the difficulties in security for cloud environment, facilitating the data collection, reducing detection time and consequently enabling an almost real-time attack detection.

• 한국멀티미디어학회논문지
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• 제24권8호
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• pp.1090-1100
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• 2021

Recently, as indoor activities increase due to the spread of infectious diseases, the metaverse is attracting attention. Metaverse refers to content in which the virtual world and the real world are closely related, and its representative platform technology is VR(Virtual Reality). However, since VR hardware is difficult to access in terms of cost, the concept of streaming-based cloud VR has emerged. This study proposes a server configuration and deployment method in an edge network when metaverse content involving multiple users operates based on cloud VR. The proposed algorithm deploys the edge server in consideration of the network and computing resources and client location for cloud VR, which requires a high level of computing resources while at the same time is very sensitive to latency. Based on simulation, it is confirmed that the proposed algorithm can effectively reduce the total network traffic load regardless of the number of applications or the number of users through comparison with the existing deployment method.

• 전자공학회논문지CI
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• 제47권6호
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• pp.19-27
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• 2010

클라우드 컴퓨팅 서비스 환경에서 인증 및 접근 제어와 같은 여러 보안 이슈가 발생하고 있다. 특히, 클라우드 컴퓨팅 환경에서 다양한 자원에 접속을 할 경우, 통합적으로 관리 및 제어가 가능한 인증 및 접근제어 모델이 필요하다. 이를 해결하기 위해서, 본 논문에서는 클라우드 컴퓨팅 환경에서 상황인식 기술과 통합인증 기술, 접근제어 기술, OSGi 서비스 플랫폼 기술을 접목하여, 상황인식 기반의 통합 인증(SSO) 및 접근제어 시스템을 제안한다. 또한 제안 시스템을 설계 및 구현함으로써, 클라우드 컴퓨팅 환경에서 상황에 따른 다양한 Multi Fact기반의 통합인증을 통하여 유연하고, 편리한 보안 시스템을 검증하였다. 이를 통하여 클라우드 컴퓨팅 환경에서 사용자 상황에 따라, 유연하고, 안전한 무중단 보안 서비스를 제공할 수 있음을 확인할 수 있었다.