• Journal of Information Processing Systems
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• 제8권4호
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• pp.589-602
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• 2012

With the increasing demand for real time applications in the Wireless Senor Network (WSN), real time critical events anticipate an efficient quality-of-service (QoS) based routing for data delivery from the network infrastructure. Designing such QoS based routing protocol to meet the reliability and delay guarantee of critical events while preserving the energy efficiency is a challenging task. Considerable research has been focused on developing robust energy efficient QoS based routing protocols. In this paper, we present the state of the research by summarizing the work on QoS based routing protocols that has already been published and by highlighting the QoS issues that are being addressed. The performance comparison of QoS based routing protocols such as SAR, MMSPEED, MCMP, MCBR, and EQSR has also been analyzed using ns-2 for various parameters.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2004년도 춘계종합학술대회
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• pp.408-411
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• 2004

In this paper, we evalvated two main QoS supporting routing protorol on wireless ad hoc network. At Presence wireless mobile communication focuses on how to efficiently support mobility of users more than QoS guarantee. However, in order to satisfy requirement of various applications which have been or will be served, QoS support service between source and destination becoming a very important issue. Of all routing protocols, DSR and AOUV are very improtant routing protocol in MANET. So we simulated DSR and AODV QoS Routing Protocol Through simulation evaluation tool NS(Network Simulation) based on various environments.

• 한국정보처리학회논문지
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• 제6권2호
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• pp.396-407
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• 1999

A Multicast transfer is a critical delivery method to provide a transport service to multipeer applications, the various problems on the multicast transfer environments have been occurred from the results of current research. One of these problems is the multicast transport service issue to guarantee reliability and scalability. First, this paper presents the related research of the reliable multicast transport methods, and then proposes a new transfer architecture using the Agent Sender and Receiver Concept(ASRC) to solve a reliable multicast transfer issue. we also propose a method to apply the proposed architecture(ASRC) to the well-known sender-initiated and receiver-initiated transport protocol. In order 새 validate the proposed ASRC architecture, t도 applied sender and receiver system si compared and analyzed over the processing requirement and maximum throughput.

• 한국시뮬레이션학회:학술대회논문집
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• 한국시뮬레이션학회 2003년도 추계학술대회 및 정기총회
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• pp.139-144
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• 2003

Mobile Node has to maintain communication as they move form place to place, so it doesn't guarantee Quality of Service(QoS). Fast Handoff is important to provide multimedia and real-time applications services in mobile, and it is closely related to handoff delay. Therefore, handoff delay problem is actively studied to quarantee QoS as a main issue in mobile IP research area. Next generation Mobile IPv6 resolve this problem somewhat, triangle problem for first packet and handoff delay still remain. In this paper, we suggest SNMP Information-based routing that adds keyword management method to Information-based routing in active network in order to resolve such a problem, and then suggest QoS controlled handoff based on SNMP Information-Based routing. After modeling of suggested method and existing handoff method, simulations are carried out with NS-2 for performance evaluation. The results of simulations show the some improvement on handoff delay, and therefore on QoS improvement.

• 전자통신동향분석
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• 제36권4호
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• pp.1-12
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• 2021

The competition to lead the next generation of mobile technologies, 6G, is underway while the deployment of 5G has not been implemented worldwide. ITU-R plans to develop technical requirements and standards after completing the 6G Vision by 2023. It can be considered too early to have a concrete view of the 6G core network architecture from this timeline. However, major stakeholders have started making their presence felt by publishing their views. From updated analysis on the technology and service trends proposed, we present a list of research directions on 6G core network from several perspectives: distribution of network functions to nearer edge locations; future fixed-mobile convergence, including low earth orbit satellites; highly-precise QoS guarantee; supporting an extremely wide variety of service requirements; AI-native automation and intelligence; and aligning with the evolution of radio access network.

• 무역상무연구
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• 제52권
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• pp.25-44
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• 2011

Possibility of credit risk, foreign exchange risk and interest rate risk of exporter increases in the recent international Commercial transactions, due to financial crisis of Europe and liberalization of Middle East. Under this circumstance, Forfaiting is trade finance that forfaiter purchase negotiable debt instrument without recourse from exporter, which occurred related with international commercial transactions, and credit risk, contingency risk, foreign exchange risk and interest rate risk of exporter can be transferred to forfaiter. Forfaiting is typically medium-term finance(three to five years) concluded at fixed interest rate, although it can also arranged on a floating interest-bearing basis for periods from six months to ten years or more. But Forfaiting service of Korea has limitation as follows. First, forfaiting in Korea deals with unrestricted irrevocable documentary credit as debt instruments. Period that forfaiting is provided is short and amount of money is limited, compared with advanced forfaiting. But forfaiting provided in advanced countries deals with various methods such as guarantee for bill, payment guarantee, and can be resold in financial market. Recently importance of forfaiting is increasing in international commercial transactions. Therefore profound study on forfaiting is required. The study will examine the risk that happens to the concerned parties in forfaiting, and its management measures. The study adopted literature review method such as local and foreign books and papers about trade finance, internet information about forfaiting, and professional journal related with international finance.

• 한국산업융합학회 논문집
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• 제3권2호
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• pp.167-178
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• 2000

Software RAID(Redundant Arrays of Inexpensive Disks) is defined as a storage system that provides capabilities of hardware RAID, and guarantees high reliability as well as high performance. In this paper, we propose an enhanced disk scheduling algorithm and a scheme to guarantee reliability of data. We also design and implement software RAID by utilizing these mechanism to develop a storage system for multimedia applications. Because the proposed algorithm improves a defect of traditional GSS algorithm that disk I/O requests arc served in a fixed order, it minimizes buffer consumption and reduces the number of deadline miss through service group exchange. Software RAID also alleviates data copy overhead during disk services by sharing kernel memory. Even though the implemented software RAID uses the parity approach to guarantee reliability of data, it adopts different data allocation scheme. Therefore, we reduce disk accesses in logical XOR operations to compute the new parity data on all write operations. In the performance evaluation experiments, we found that if we apply the proposed schemes to implement the Software RAID, it can be used as a storage system for small-sized video-on-demand servers.

• 한국정보과학회논문지:컴퓨팅의 실제 및 레터
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• 제14권2호
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• pp.206-210
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• 2008

프로그레시브 스트리밍의 가장 큰 특징은 TCP를 통해 전송된 미디어 데이타가 수신 단말기로 다운로드 됨과 동시에 미디어의 재생이 실행되는 것이다. 프로그레시브 스트리밍에서는 TCP의 순서번호(sequence number)나 검사합(checksum) 기능 등을 통하여 손실된 패킷을 검출하여 재전송을 통해 복원이 가능하다. 그러나, 재전송에 소요되는 시간 동안 재생될 수 있는 충분한 량의 미디어 데이타가 수신 단말기 버퍼에 남아 있어야만 미디어의 끊김 없는 서비스가 가능하다. 본 논문에서는 이러한 끊김 없는 서비스가 가능하도록 수신 단말기의 버퍼 고갈 확률을 고려하여 실시간으로 초기 버퍼링 시간을 결정하는 방법을 제안하고 실험을 통해 제안된 방법의 효과를 검증한다.

• 한국콘텐츠학회논문지
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• 제5권5호
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• pp.248-254
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• 2005

기존의 버퍼 관리 방법은 TCP 트래픽의 "burstness" 특성으로 인해 손실 없는 전송만으로는 GFR이 요구하는 최소 전송률 보장과 공평성을 제공하기 어렵다. 본 논문에서는 GFR이 요구하는 최소 전송률 보장과 높은 공평성을 제공하기 위하여 기존의 버퍼관리 기법에 퍼지 이론을 적용한 버퍼관리 알고리즘을 제안하였다. 제안된 알고리즘은 태깅정보, 버퍼 점유량, VC의 부하정도로 구성된 세 개의 파라미터를 이용하여 패킷 폐기를 결정한다. 시뮬레이션 결과 MCR의 크기가 커질수록 제안된 알고리즘의 수율과 공평성이 우수하였으며, 스위치에서 버퍼의 크기 변화에서도 Double-EPD나 DFBA는 비슷한 성능을 보였고, 제안된 알고리즘은 좋은 수율과 공평성을 제공한다.

• 한국멀티미디어학회논문지
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• 제20권9호
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• pp.1559-1566
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• 2017

Recently in the IoT(Internet of Things) environment, a data collection in real-time through device's sensor has increased with an emergence of various devices. Collected data from IoT environment shows a large scale, non-uniform generation cycle and atypical. For this reason, the distributed processing technique is required to analyze the IoT sensor data. However if you do not consider the optimal scheduling for data and the processor of IoT in a distributed processing environment complexity increase the amount in assigning a task, the user is difficult to guarantee the QoS(Quality of Service) for the sensor data. In this paper, we propose APQTA(Adaptive Priority Queue-driven Task Allocation method for sensor data processing) to efficiently process the sensor data generated by the IoT environment. APQTA is to separate the data into job and by applying the priority allocation scheduling based on the deadline to ensure that guarantee the QoS at the same time increasing the efficiency of the data processing.