• International journal of advanced smart convergence
• /
• 제4권1호
• /
• pp.31-34
• /
• 2015

Recently, the various types of data are began to increase. In order to manage the data efficiently, a variety of cloud services are being made. However, while providing a cloud service, the problem is the cost and waste a lot of human power to manage the data that is generated and managed by the server. To solve this problem, it is build the cloud environment using a single board computer with Raspberry pi. In this paper, we used Raspberry pi as a cloud server to provide services for the users. And we construct a Total Server to manage the generated data. It can separate the processing of data and the provision of services. We ensure the efficient operation by building a cloud environment with Raspberry pi and by managing the data which generated in cloud environment with the total server.

• 한국정보처리학회논문지
• /
• 제6권11S호
• /
• pp.3379-3389
• /
• 1999

Important network application services have been rapidly increased along with the growth of the Internet. So, it is desirable for such applications to serve transparently, continuously and safely even if the network is temporally disconnected or certain hosts running those services are crashed down. To satisfy such requirementes, many group communication systems have been developed; but, those systems restrict its range within a single LAN or directly interconnected LAN environments since the communication through the Internet is too slow and too unreliable to support group communication. As of now, it is expected the Internet is going to e sufficiently fast and reliable in the near communication system, named FACE(Java Advanced Communication Environment), supporting Extended Virtual which is a basic communication layer, RPGS(Reliable Process Group Service) which manages application process groups, and JACE API for developing Java application services and clients programs. In addition, an experimental replicated object space is developed as an application of the JACE system.

• Asia pacific journal of information systems
• /
• 제12권3호
• /
• pp.169-189
• /
• 2002

In this study, we newly classify services and service products in EC into Mass Service, Interactive Service, Ordering Service, and Professional Service. For classification, five selected variables and two factorized dimensions such as 1) ease of on-line interaction and 2) needs of on-line interactions are used. On the result of classification, we investigate the relationships with customer purchase intentions in EC. For this purpose, customer surveys were conducted on the respondent groups who are known to be frequent purchasers in EC and have advanced knowledge on services and service products. The survey is analyzed by statistical methods such as factor score plot, cluster analysis, analysis of variance, etc.

• The Journal of the Acoustical Society of Korea
• /
• 제23권3E호
• /
• pp.74-78
• /
• 2004

As analog audio systems are changing to digital systems, the DAB (Digital Audio Broadcasting) is expected to provide CD quality audio, various data services with interactiveness and excellent mobile reception ability. The DMB (Digital Multimedia Broadcasting), as more advanced successor of the DAB, adds video capability on the audio and data services. The DAB system assures high quality audio services even when the reception is through portable and mobile receivers. In this paper, USB-DAB receiver and PCI-DMB receiver are designed and implemented. The DAB receiver and the DMB receiver incorporate with PC to make use of computational power and application software of Pc. This enables the developed system to be more flexible and to meet various applications easier.

• 한국정보통신설비학회:학술대회논문집
• /
• 한국정보통신설비학회 2008년도 정보통신설비 학술대회
• /
• pp.447-453
• /
• 2008

It is decidedly important to ensure QoS(Quality of Service) in order to make it possible a variety of multi-media services and realtime contents services in Wireless networks. One of methods to offer these services is the advanced prediction of Handoff through terminal's directional. In this paper, it is applied that the AP weight for the ground information of peripheral cell and the weight value of history table for the cell frequently visited. Also, it is expected that will be guarant QoS of substantial data in the case of Handoff through exact directional prediction of the next cell by using Kalman Filter algorithm applied GPS coordinates value.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• 제6권10호
• /
• pp.2455-2472
• /
• 2012

Although underlay spectrum sharing has been shown as a promising technique to promote the spectrum utilization in cognitive radio networks (CRNs), it may suffer bad secondary performance due to the strict power constraints imposed at secondary systems and the interference from primary systems. In this paper, we propose a two-phase based cooperative transmission protocol with the interference cancellation (IC) and best-relay selection to improve the secondary performance in underlay models under stringent power constraints while ensuring the primary quality-of-service (QoS). In the proposed protocol, IC is employed at both the secondary relays and the secondary destination, where the IC-based best-relay selection and cooperative relaying schemes are well developed to reduce the interference from primary systems. The closed-form expression of secondary outage probability is derived for the proposed protocol over Rayleigh fading channels. Simulation results show that, with a guaranteed primary outage probability, the proposed protocol can achieve not only lower secondary outage probability but also higher secondary diversity order than the traditional underlay case.

• 한국정보과학회:학술대회논문집
• /
• 한국정보과학회 2006년도 한국컴퓨터종합학술대회 논문집 Vol.33 No.1 (D)
• /
• pp.217-219
• /
• 2006

4G mobile networks are expected to support various multimedia services over IP networks and also satisfy high spectral efficiency requirement. In cellular systems including 4G networks, hotspot cells can occur when available wireless resources at some location are not enough to sustain the needs of users. The hotspot cell can potentially lead to blocked and dropped calls, which can deteriorate the service quality for users. In a 4G mobile network, a band of users enjoying multimedia services can move around, which may generate heavy flows of traffic load. This situation can generate the hotspot cell which has a short life span of only a few minutes. In this paper, we propose a handover-based scheme which can effectively manage hotspot cells in 4G mobile networks. With the scheme, the current serving cell can recognize the load status of the target cell in advance before handover execution. Adaptive handover time control according to the amount of traffic load of cells can effectively and flexibly manage the hotspot cell in the network. And, through our hotspot cell management scheme, acceptable service quality can be supported as users continuously maintain connections with the network. In the simulation results, we find that our scheme generates smaller number of hotspot cells and supports higher service quality than the compared schemes.

• 한국콘텐츠학회논문지
• /
• 제11권5호
• /
• pp.57-66
• /
• 2011

최근 인구 고령화와 만성질환자의 증가로 건강에 대한 관심이 높아지고, IT기술의 선진적인 발달로 인하여 건강관리에 대한 서비스가 증가하고 있다. 이로 인하여 병원뿐만 아니라 가정에서도 자신의 건강상태를 모니터링하고 특화된 건강관리 서비스의 제공이 요구된다. 본 논문은 사용자의 생체 신호 데이터를 통해 상황정보와 연계된 측정 및 특이환자 알림 서비스를 제공하며, 지수에 따른 알림 서비스를 제공하는 고혈압 모니터링 및 알림 서비스 시스템을 제안한다. 본 시스템은 기존의 모니터링 서비스와 차별화되어 사용자의 상황을 고려하므로 좀 더 정확한 측정값을 얻을 수 있으며, 특이환자의 관리와 생활과 연관된 지수를 통하여 사용자의 건강위험을 줄일 수 있다. 또한 사용자에게는 정확하고 세분화된 서비스가 가능하고 더욱 맞춤화된 서비스를 제공할 수 있을 것으로 기대된다.

• 한국인터넷방송통신학회논문지
• /
• 제11권2호
• /
• pp.171-179
• /
• 2011

오늘날 발달된 무선 네트워크 통신의 기술로 인해 많은 데이터를 빠르게 전송할 수가 있으며, 또한 더 좋은 단말기의 등장으로 멀티미디어 정보를 보여줄 수 있기 때문에 다양한 무선 인터넷 서비스가 가능하게 되었다. 따라서 SKT나 LGT와 같은 통신업체는 2.5세대 무선 기술과 스마트카드를 이용하여 온라인 쇼핑, 모바일뱅킹 등 많은 서비스를 제공하고 있다. 핸드폰을 대부분 사람들이 소유하고 있기 때문에 교통 시스템에 유용한 지불시스템으로 사용할 수 있는데, 모바일 지불 시스템이 무선 온라인 서비스로 이미 개발되어져 있기 때문이다. 본 논문에서는 모바일 교통 지불 시스템이 소개되고 있다. 운전자는 고속도로를 이용할 때 통행료를 지불해야한다. 최근에 하이패스 시스템이 개발되어 자동차는 요금을 지불하기 위해 정지하지 않고 톨게이트를 지나가면서 자동적으로 지불이 가능하다. 이러한 지불은 장착된 지불 시스템으로 인해 가능하다. 우리는 좀 더 발전된 형태로 스마트카드를 장착한 핸드폰을 지불 기기로 사용할 수 있는 시스템을 개발하였다. 개인과 금전 정보는 스마트카드에 저장되고 단말기와 OBU와의 통신은 불루투스 방식을 사용한다.

• 한국정보통신학회:학술대회논문집
• /
• 한국해양정보통신학회 2007년도 추계종합학술대회
• /
• pp.113-116
• /
• 2007

현재 국내에서는 지상파-DMB(T-DMB)가 거의 모든 대도시를 중심으로 서비스가 되고 있으나, 한정된 대역폭으로 인하여 최대 CIF급 화면 해상도까지 서비스가 가능하다. 고품질의 이동 멀티미디어 서비스에 대한 사용자의 요구가 증대되고, 계층 변조 전송 기법을 통하여 추가적인 전송 대역폭을 확보할 수 있게 됨에 따라, 고품질-DMB(Advanced Terrestrial-DMB) 서비스를 SVC(Scalable Video Coding) 기법으로 제공하기 위한 연구가 활발히 진행되고 있다. 본 논문에 서비스를 제공하기 위한 대역할당 크기에 따른 품질 특성을 조사 분석한다. 또한, T-DMB와 AT-DMB간의 동적인 대역 할당 방식에 따른 각 계층 간 성능 변화를 영상 시퀀스별로 조사 분석한다.