• 한국콘텐츠학회:학술대회논문집
• /
• 한국콘텐츠학회 2015년도 춘계 종합학술대회 논문집
• /
• pp.33-34
• /
• 2015

Continuous improvements of network infrastructures and mobile data offloading strategies are among the solutions of cellular providers to cope with the increase in mobile data demand. These options requires a lot of cost and time to implement. Few researches have been conducted to assess the applicability of Pocket Switched Network (PSN) to support mobile data offloading. In this paper, we present a PSN mobile data-offloading scheme that utilizes mobile users with available connectivity to deliver content-aware data to other mobile users. This paper also aims to evaluate the applicability and feasibility of PSN routing schemes to improve the current strategies in mobile data offloading. The simulation results show admirable results in terms of message delivery and latency.

• 정보처리학회논문지:컴퓨터 및 통신 시스템
• /
• 제2권6호
• /
• pp.253-256
• /
• 2013

VANET에서는 차량 안전 관련 정보가 차량들 간에 안정적으로 전달될 수 있도록 해주는 라우팅 프로토콜이 요구된다. 본 논문에서는 도시기반의 VANET 환경에서 차량 간의 빠르고 안정적인 통신을 위하여 차량 밀도 정보를 이용한 라우팅 기법을 제안한다. 제안 기법에서 각 차량은 비콘 메시지와 도로 정보을 이용해서 도로의 차량 밀도를 계산한다. 차량들은 이 정보를 이용해서 패킷을 전송할 안정적인 경로를 설정한다. NS-2 시뮬레이션을 통해 제안 기법과 GPSR의 성능을 비교했으며, 그 결과 제안 기법이 패킷 전송 성공률 측면에서 우수한 성능을 보임을 알 수 있었다.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• 제9권9호
• /
• pp.3594-3610
• /
• 2015

Recent advancements in broadband wireless communication technologies enable mobile users to receive video streaming services with various smart devices. The long term evolution (LTE) network provides high bandwidth and low latency for several emerging mobile applications. This paper proposes the buffer aware scheduling (BAS) approach to schedule the downlink video traffic in LTE network. The proposed BAS scheme applies the weighting function to heuristically adjust the scheduling priority by considering the buffer status and channel condition of UE so as to reduce the time that UE stays in the connected state without receiving data. Both of 1080P and 2160P resolution video streaming sources were applied for exhaustive simulations to examine the performance of the proposed scheme by comparing to that of the fair bandwidth (FB) and the best channel quality indicator (CQI) schemes. The simulation results indicate that the proposed BAS scheme not only achieves better performance in power saving, streaming delivery time, and throughput than the FB scheme while maintaining the similar performance as the best CQI scheme in light traffic load. Specifically, the proposed scheme reduces streaming delivery time and generates less signaling overhead than the best CQI scheme when the traffic load is heavy.

• 대한전자공학회:학술대회논문집
• /
• 대한전자공학회 2002년도 하계종합학술대회 논문집(1)
• /
• pp.157-160
• /
• 2002

For a company operating lots of vehicle, such as taxi companies or delivery company, a system telling the position of each vehicle is essential. Conventional methods are based on personal communication between a operator in head-office and driver at the car. Since driver cannot respond to the communication while he drives or when lie is out of car. the communication often fails. So, a system identifying and reporting the vehicle position offers groat help to those kind of company.

• 한국도서관정보학회지
• /
• 제26권
• /
• pp.441-478
• /
• 1997

This paper surveyed the development and future of electronic journals. The growing and impact of electronic publishing, developments and access of electronic journals, and the future of electronic journals were examined in detail, and remaining problems were analyzed. The findings of the study can be summarized as follows : 1. The future of electronic journals is not an issue of technology it is an issue of economics and social policy. And, the cost of delivering an electronic version to end-users were more expensive. 2. More sophisticated markup software and display software system are needed for fully structured text versions of articles. 3. Coordination of effort is essential in order that we maximize the end-users access requirements against resonable protection for the intellecture effort of the scholarly writer. 4. The success of an electronic journals will depend on the improved communication and cooperation between libraries, users, author, publishers, and information technology specialists. The advent of electronic information delivery has brought with it these issues to be solved. And development in the delivery of scholarly information by electronic means will accelerate.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• 제9권10호
• /
• pp.3851-3866
• /
• 2015

The dynamic nature of opportunistic networks results in long delays, low rates of success for deliveries, etc. As such user experience is limited, and the further development of opportunistic networks is constrained. This paper proposes a prediction-based routing method for opportunistic networks (PB-OppNet). Firstly, using an ARIMA model, PB-OppNet describes the historical contact information between a node pair as a time series to predict the average encounter time interval of the node pair. Secondly, using an optimal stopping rule, PB-OppNet obtains a threshold for encounter time intervals as forwarding utility. Based on this threshold, a node can easily make decisions of stopping observing, or delivering messages when potential forwarding nodes enter its communication range. It can also report different encounter time intervals to the destination node. With the threshold, PB-OppNet can achieve a better compromise of forwarding utility and waiting delay, so that delivery delay is minimized. The simulation experiment result presented here shows that PB-OppNet is better than existing methods in prediction accuracy for links, delivery delays, delivery success rates, etc.

• 한국위성정보통신학회논문지
• /
• 제7권3호
• /
• pp.75-77
• /
• 2012

최근 들어 다양한 이동 수단의 발전과 함께 철도 또한 많은 발전을 이루었다. 이렇게 발전된 철도 시스템과 더불어 정확한 철도 시스템 정보 전달을 위한 효율적인 통신시스템이 요구되었고, 이에 따라 철도 통신 시스템 또한 다양한 방식으로 발전했다. 철도 무선통신에서 페이딩의 영향을 최소화 하고 보다 효율적인 통신을 하기위해, 협력 통신방식이 제기되었다. 본 논문에서는 다양한 방식의 무선 통신방법 중 협력 전송 기법에 대해 소개하고, 이에 따른 채널 특성과 통신 예시 등을 소개할 것이다.

• 한국콘텐츠학회논문지
• /
• 제7권4호
• /
• pp.250-258
• /
• 2007

타이포그래피는 언어와 조형의 결합이다. 언어의 이해와 조형적 가치를 통한 인간 커뮤니케이션의 핵심적인 수단인 것이다. 가장 기본적인 역할인 정보의 전달과 공유에서 장애요소로 나타나는 '언어의 반작용' 현상을 극복하고자 여러 가지 기법을 도입한 연구가 시작되었고, 보다 가독성 있고 의미전달력에 있어서도 효과적인 움직이는 활자를 개발하여 보편화되기에 이르렀다. 그러나 그것은 컴퓨터 모니터나 영상화면, 그리고 휴대전화 액정 등의 영상 디지털 미디어에서는 실현이 용이하나, 전통적 정보전달 매체인 인쇄지면이나 주변 환경에서 흔히 접할 수 있는 빌보드, 사인보드 등에서는 사실상 표현이 어렵다. 이를 위한 하나의 해결 방법으로 메시지 전달력이나 가독성에서 기존의 정적인 타이포그래피보다 훨씬 강력한 소구력을 가지는 동적타이포그래피에서 표현의 핵심요소인 시 공간적 표현효과에 대응하는 시각적 의미전달 체계를 색채의 본질과 특성에서 접근하여 동적표현에 근접한 커뮤니케이션 효과를 창출하고자 한다.

• Journal of information and communication convergence engineering
• /
• 제3권1호
• /
• pp.56-61
• /
• 2005

In this paper, we present a video rate control scheme for storage and delivery in which the time-varying viewing interests are controlled by human gaze. To track the gaze, the pupil's movement is detected using the three-step process : detecting face region, eye region, and pupil point. To control bit rates, the quantization parameter (QP) is changed by considering the static parameters, the video object priority derived from the pupil tracking, the target PSNR, and the weighted distortion value of the coder. As results, we achieved human interfaced visual model and corresponding region-of-interest rate control system.

• 대한전자공학회:학술대회논문집
• /
• 대한전자공학회 1998년도 하계종합학술대회논문집
• /
• pp.557-560
• /
• 1998

In this paper, we presetn the WWW (world-wide-web) base dtelePACS, which uses the communication network as asymmetric satellite data communication system (ASDCS). Web-based telePACS is imple-mented with JAVA language. Through the internet, web-based TelePACS can make it possible for remote hospital or doctor to access PACS data and information easily and cheaply. The ASDCS uses receive-only satellite links for data delivery and PSTN (Public switched telephone Network) modem or N-ISDN (narrow band integrate services digital network) for communication. The satellite communication linking shows the very high-seed performance such as 10-30 times faster than the modem linking.To solve the speed limits of internet, JPEG and wavelet compression methods were adapted in WWW-based TelePACS and were evaluated by PSNR (peak signal-to-noise ratio) and by radiological experts that 10:1 or less JPEG and wavelet compression may be acceptable for diagnostic purposes. Consequently, we get the conslusion that our system is suitable for tele-radiology and telemedicine world widely.