• Journal of Computing Science and Engineering
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• 제7권3호
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• pp.168-176
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• 2013

Long-term evolution (LTE) is emerging as a major candidate for 4G cellular networks to satisfy the increasing demands for mobile broadband services, particularly multimedia delivery. Multiple-input multiple-output (MIMO) technology combined with orthogonal frequency division multiple access and more efficient modulation/coding schemes (MCS) are key physical layer technologies in LTE networks. However, in order to fully utilize the benefits of the advances in physical layer technologies, the MIMO configuration and MCS need to be dynamically adjusted to derive the promised gains of 4G at the application level. This paper provides a performance evaluation of video traffic with variations in the physical layer transmission parameters to suit the varying channel conditions. A quantitative analysis is provided using the perceived video quality as a video quality measure (evaluated using no-reference blocking and blurring metrics), as well as transmission delay. Experiments are performed to measure the performance with changes in modulation and code rates in poor and good channel conditions. We discuss how an adaptive scheme can optimize the performance over a varying channel.

• Animal Systematics, Evolution and Diversity
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• 제17권2호
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• pp.245-250
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• 2001

한국 가거도에서 채집된 모래해면속(망각해면목: 가는실해면과)의 2 신종, 버키스트모래해면(Psammocinis bergquisti n. sp.) 과 가거모래해면(P. gageoensis n. sp.)을 기색한다. 버키스트모래해면은 외형이 엄지손가락 모양이며 지금까지 알려진 모래해면 속의 종들은 좁고 단순한 형태의 2차섬유를 갖는 반면 본 신종은 2차섬유가 얇은 판 모양이거나 넓은 망구조이다. 가거모래해면은 모슬모래해면(P. mosulpia Sim. 1998) 과 외형에서 매우 유사하지만, 1차섬유가 복잡한 총생모양으로 섬유 내부에 있는 모래와 골편들의 겉으로 잘 보이지 않은 점이 특징이다. 가거모래해면의 1차섬유 속에는 모슬모래해면의 1차섬유 속의 모래보다 작은 모래들이 있다.

• 천문학회지
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• 제40권4호
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• pp.165-169
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• 2007

The numerical simulations associated with the interaction of High Velocity Clouds (HVC) with the Magnetized Galactic Interstellar Medium (ISM) are a powerful tool to describe the evolution of the interaction of these objects in our Galaxy. In this work we present a new project referred to as Theoretical Virtual i Observatories. It is oriented toward to perform numerical simulations in real time through a Web page. This is a powerful astrophysical computational tool that consists of an intuitive graphical user interface (GUI) and a database produced by numerical calculations. In this Website the user can make use of the existing numerical simulations from the database or run a new simulation introducing initial conditions such as temperatures, densities, velocities, and magnetic field intensities for both the ISM and HVC. The prototype is programmed using Linux, Apache, MySQL, and PHP (LAMP), based on the open source philosophy. All simulations were performed with the MHD code ZEUS-3D, which solves the ideal MHD equations by finite differences on a fixed Eulerian mesh. Finally, we present typical results that can be obtained with this tool.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제14권7호
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• pp.2815-2839
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• 2020

In a cloud computing paradigm, allocation of various virtualized ICT resources is a complex problem due to the presence of heterogeneous application (MapReduce, content delivery and networks web applications) workloads having contentious allocation requirements in terms of ICT resource capacities (resource utilization, execution time, response time, etc.). This task of resource allocation becomes more challenging due to finite available resources and increasing consumer demands. Therefore, many unique models and techniques have been proposed to allocate resources efficiently. However, there is no published research available in this domain that clearly address this research problem and provides research taxonomy for classification of resource allocation techniques including strategic, target resources, optimization, scheduling and power. Hence, the main aim of this paper is to identify open challenges faced by the cloud service provider related to allocation of resource such as servers, storage and networks in cloud computing. More than 70 articles, between year 2007 and 2020, related to resource allocation in cloud computing have been shortlisted through a structured mechanism and are reviewed under clearly defined objectives. Lastly, the evolution of research in resource allocation techniques has also been discussed along with salient future directions in this area.

• 방송공학회논문지
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• 제13권5호
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• pp.752-759
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• 2008

최근 방송과 통신의 융합은 미디어와 미디어 사이의 영역의 한계를 모호하게 하고 있다. 매체의 진화에 따른 디지털 기술의 발전에 따라 사용자는 상호작용성을 경험하였다. 특히 불특정 다수의 참가자가 실시간 환경 속에서 동일한 목표를 가지고 몰입 하거나 경쟁 하면서 만족을 추구하는 MMORPG(Massively Multi-player On line Role Play Game)는 사용자에게 새로운 형태의 문화와 만족감을 주고 있다. ARG(Alternative Reality Game)는 미디어의 융합에 의해 새로이 탄생한 대체현실게임으로, ARS, SMS, BLOG, Cafe, Message 등을 통해 사용자와 사용자간에 보다 더 현실적인 상호작용을 수행한다. 본 논문에서는 ARG를 소개하고, ARG의 구현, 설계, 구축의 방법을 인간의 사고와 미디어 측면에서 분석하였으며, ARG 활성화를 통해 방송의 새로운 방향을 제언한다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제12권8호
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• pp.3606-3629
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• 2018

The discovered high potential utility itemsets (HPUIs) have significant influence on a variety of areas, such as retail marketing, web click analysis, and biological gene analysis. Thus, in this paper, we propose an algorithm called HPUIM-QGA (Mining high potential utility itemsets based on a quantum genetic algorithm) to mine HPUIs over uncertain datasets based on a quantum genetic algorithm (QGA). The proposed algorithm not only can handle the problem of the non-downward closure property by developing an upper bound of the potential utility (UBPU) (which prunes the unpromising itemsets in the early stage) but can also handle the problem of combinatorial explosion by introducing a QGA, which finds optimal solutions quickly and needs to set only very few parameters. Furthermore, a pruning strategy has been designed to avoid the meaningless and redundant itemsets that are generated in the evolution process of the QGA. As proof of the HPUIM-QGA, a substantial number of experiments are performed on the runtime, memory usage, analysis of the discovered itemsets and the convergence on real-life and synthetic datasets. The results show that our proposed algorithm is reasonable and acceptable for mining meaningful HPUIs from uncertain datasets.

• 한국콘텐츠학회논문지
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• 제10권12호
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• pp.77-83
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• 2010

최근, IT 기반의 환경은 웹서비스의 플랫폼의 변화, 클라우딩 컴퓨팅환경으로의 진화, 스마트 시장의 저변확대로 급속히 변화되고 있는 실정이다. 이와 함께 모니터링 개발 환경도 급속히 변화되고 있다. 이에, 사용자 정의가 가능한 SaaS기반의 모니터링 제공 서비스가 요구된다. 다양한 모니터링 환경을 지원하고 관리자가 요구한 자원 정보를 사용하고 있는 향상된 모니터링 프레임워크로써 클라우딩 컴퓨팅 환경의 SaaS 플랫폼의 고성능 저비용 클러스터 관리 시스템이 가능한 클라우딩 컴퓨팅 시스템이 요구된다. 그리하여 본 연구의 목표는 클라우딩 컴퓨팅 환경의 SaaS 기반 플랫폼의 효율적이고 사용자 정의 가능한 모바일 인터페이스를 가진 3D 뷰어가 제공되는 모니터링 시스템을 제공하는 것이다.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2015년도 추계학술대회
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• pp.149-150
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• 2015

오늘날 현재 우리나라의 정보통신의 급속한 발전은 우리의 일상생활에 광범위한 영역에 영향을 미치고 있으며, 사용자 경험에 대한 인식이 높아지고 있다. 인터넷 쇼핑몰, 포탈 웹 사이트, 기업 웹 사이트 등 인터넷에 연결된 정보시스템의 이용이 활발하게 이루어지면서 발생하고 있는 문제 중 하나는 정보프라이버시 염려 관련되어 있다. 국내외 정보시스템, 마케팅, 기타 분야의 주요저널을 중심으로 프라이버시 관련 연구를 분석하였다. 본 연구의 목적은 정보프라이버시 염려 관련 국내외 연구의 리뷰를 통하여 연구경향과 앞으로 연구방향을 제공하는 것이다. 따라서 전자상거래 환경에서 프라이버시 염려가 사용의도에 미치는 영향을 알아보고자 한다. 분석결과를 바탕으로 이론적 실무적 시사점을 제시하고 논의하고자 한다.

• 한국IT서비스학회지
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• 제15권4호
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• pp.41-62
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• 2016

In Internet of Things (IoT) era, more diverse types of information are collected and the environment of information usage, distribution, and processing is changing. Recently, there have been a growing number of cases involving breach and infringement of personal information in IoT services, for examples, including data breach incidents of Web cam service or drone and hacking cases of smart connected car or individual monitoring service. With the evolution of IoT, concerns on personal information protection has become a crucial issue and thus the risk analysis and management method of personal information should be systematically prepared. This study shows risk factors in IoT regarding possible breach of personal information and infringement of privacy. We propose "a risk analysis framework of protecting personal information in IoT environments" consisting of asset (personal information-type and sensitivity) subject to risk, threats of infringement (device, network, and server points), and social impact caused from the privacy incident. To verify this proposed framework, we conducted risk analysis of IoT services (smart communication device, connected car, smart healthcare, smart home, and smart infra) using this framework. Based on the analysis results, we identified the level of risk to personal information in IoT services and suggested measures to protect personal information and appropriately use it.

• Genomics & Informatics
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• 제16권4호
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• pp.28.1-28.6
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• 2018

Due to the increasing interest in synonymous codons, several codon bias-related terms were introduced. As one measure of them, the tRNA adaptation index (tAI) was invented about a decade ago. The tAI is a measure of translational efficiency for a gene and is calculated based on the abundance of intracellular tRNA and the binding strength between a codon and a tRNA. The index has been widely used in various fields of molecular evolution, genetics, and pharmacology. Afterwards, an improved version of the index, named specific tRNA adaptation index (stAI), was developed by adapting tRNA copy numbers in species. Although a subsequently developed webserver (stAIcalc) provided tools that calculated stAI values, it was not available to access pre-calculated values. In addition to about 100 species in stAIcalc, we calculated stAI values for whole coding sequences in 148 species. To enable easy access to this index, we constructed a novel web database, named STADIUM (Species-specific tRNA adaptive index compendium). STADIUM provides not only the stAI value of each gene but also statistics based on pathway-based classification. The database is expected to help researchers who have interests in codon optimality and the role of synonymous codons. STADIUM is freely available at http://stadium.pmrc.re.kr.