• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.1897_1898
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• 2009

IPTV, 인터넷 전화 등 인터넷 가입자에게 제공되는 서비스가 지속적으로 증가하고 있으며, 서비스 종류의 증가와 동시에 통신 사업자가 제공하는 네트워크 속도의 향상에도 불구하고 서비스 사용자의 불만이 증가하고 있다. 이러한 불만의 원인은 인터넷을 이용하는 모든 서비스가 네트워크 자원을 공유하기 때문에 특정 서비스의 품질을 확보하지 못하는 현상의 발생에 기인한다. 따라서 인터넷 사업자의 입장에서는 인터넷을 이용하여 다양한 서비스가 이루어지지만, 해당 서비스의 품질을 확보하는 것이 중요한 과제로 등장하였다. 본 논문에서는 IPTV 서비스 환경과 유사한 실험망 환경을 구축하고, HD급 영상 데이터를 멀티캐스트스트리밍 방송 서비스를 통해 네트워크상에서 트래픽 부하에 따른 IPTV 수신영상품 질의 변화를 살펴보고, 영상품질에 따른 네트워크 측정요소의 임계치를 도출한다.

• Journal of KIISE:Information Networking
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• v.28 no.1
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• pp.117-125
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• 2001

본 논문은 인터넷상에서 실시간 멀티미디어 서브를 제공하기 위한 분산 멀티미디어 시스템의 설계 및 구현 방안을 제안한다. 제안하는 시스템은 데이터와 제어 채널의 분리를 통하여 다양한 멀티미디어의 효율적인 전송과 기반으로 구성되며 멀티미디어의 효율적인 실시간 전송을 지원한다. 제어 채널은 TCP와 RTCP 패킷 포맷을 기반으로 구성되며 서버와 클라이언트간의 정보교환을 지원함으로써 서비스 환경에 대한 지속적인 모니터링 및 효과적인관리를 지원한다. 특히 제안하는 서비스 품질관리 모델은 전송률에 기반하며 전송률을 협상된 서비스 품질이 보장되는 최대치와 최소치 사이에서 유지함으로써 안정된 서비스 품질을 보장한다. 즉 서비스 환경의 동적인 변화에 대응 하여 적절한 전송률과 누락된 패킷에 대한 재전송 등을 결정한다. 성능분석 결과, 제안하는 모델은 환경변화에 대한 적응성 측면에서 우수성을 나타냈으며 서비스 품질보장이 중요한 서비스에 적합함을 알 수 있었다.

• Proceedings of the Korea Information Processing Society Conference
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• 2003.05b
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• pp.1245-1248
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• 2003

Ad-hoc 네트워크는 유선 인프라의 구성이나 도움 없이 이동 단말기들로만 손쉽게 통신망을 구성하여 긴급구조나 전쟁터 등에서 무선 데이터 서비스를 제공할 수 있는 무선 네트워크를 말한다. 지금까지는 이러한 무선망에서는 품질보다는 연결 자체에 큰 의미를 두어왔으나, 최근에는 Ad-hoc 릴레이 시스템과 같은 확장된 개념의 Ad-hoc 망으로 범위가 넓혀지고 있어 품질에 대한 요구 수준이 증대되고 있다. 기존 Ad-hoc 라우팅 프로토콜들은 고품질의 안정된 멀티미디어 정보 전달과 같은 사용자들의 요구를 충족시킬 수 없으므로, Ad-hoc 네트워크에서도 유선망에서와 같은 QoS 보장을 위한 기술이 부가되어야만 하며, 본 논문에서는 이상과 같은 추세에 맞춰 보다 안정적이고 품질이 보장될 수 있도록 분산형 QoS모니터링 기법이 도입된 DQM-CBRP를 제안한다. 그리고 이 DQM 기반 CBRP 라우팅 프로토콜의 적정한 운용을 위해 시뮬레이션을 수행하고 적정 운용 노드 수나 운용 범위 등을 분석한다.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.12 no.4
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• pp.345-361
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• 2014

The systematic quality assurance activities on documents of the safety assessment are required for the safety case of the low- and intermediate-level radioactive waste disposal facility. In this paper, quality assurance system focused on the input data including the site characterization, groundwater flow, system design and monitoring are prepared and discussed. Rule for the input data selection is suggested and applied for the safety assessment which is based on the in-situ/experiment observations, final facility design and waste pileup plan, engineered barrier, field monitoring, recent biosphere, and radionuclide inventory. The reduction of data uncertainty will be expected to contribute to the safety of disposal facility further.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2006.11a
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• pp.529-532
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• 2006

The application of ubiquitous technology offers many chances for improving construction management technologies. Currently the Construction System Integration Lab (CSIL) at Pusan National University is executing research on applying ubiquitous technology for better communication in the construction process. One of the research area is the implementation of RFID for monitoring the concrete pour process. The objective of this study is to collect data occurring in the process and use the data be properly planning concrete pour activities. Case study has been done on an actual concrete work. For the study a user environment was developed interfacing on internet with RFID devices that were installed in a batch plant and a construction site. The result of the test demonstrated that the RFID-based concrete monitoring can be a feasible approach for improving the communication in the construction process.

• Food Science and Preservation
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• v.10 no.3
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• pp.308-313
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• 2003

In the present study, we investigated the optimum recipe of the pumpkin drink using old pumpkin extract. Response surface methodology (RSM) was applied to optimize and monitor the drink recipe with pumpkin extract. The polynomial equation for color, flavor, taste, mouth feel, overall palatability, pH, brix and viscometer showed 0.7682, 0.9046, 0.9364, 0.9110, 0.8456, 0.9264, 0.7135 and 0.9906 of R$^2$, respectively and flavor, taste, mouth feel, overall palatability, pH and viscometer showed 5～10％ of significance level. The optimum ranges of recipe on organoleptic properties of pumpkin pouch drink were estimated on 86.5～87.5％ of the old pumpkin extract, 0.36～0.42％ of xanthan gum and 9％ of vinegar.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.12
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• pp.6550-6557
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• 2013

The public road construction projects awarded by the regional construction and management office, which is an affiliate of the Ministry of Land, Infrastructure and Transport, are managed by construction supervision officers. These officials frequently visit a large number of construction sites to conduct inspections and supervision tasks. Therefore, the site management efficiency is essential in terms of the time and money spent in travelling to the sites. The introduction of a site monitoring management system is considered necessary to minimize the number of site visits and enable remote monitoring of the construction progress to enhance the business efficiency of the construction supervision officers. In this study, a remote site monitoring system was constructed using web cameras for public road construction works. The trial applications were implemented by selecting ten constructions sites. The effectiveness of the system was analyzed to assess its applicability. In an assessment of the applicability of the verification results, remote site monitoring showed cost savings of approximately 35% compared to the existing site management. The guidelines for applying the site monitoring management system were provided, the introduction plan was investigated, and the improvement method was presented. The results showed that the system is likely to minimize the unnecessary site visits, remove the risk factors at vulnerable areas in the sites beforehand, and prevent a range of disasters and accidents. In addition, the quality of the infrastructures is likely to improve through the prevention of accidents and the elimination of substandard and faulty construction work.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.36 no.2A
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• pp.114-126
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• 2011

Video streaming over wireless multi-hop networks(WMNs) contains the following challenges from channel fading and variable bandwidth of wireless channel, and it cause degradation of video streaming performance. To overcome the challenges, currently, WMNs can use Forward Error Correction (FEC) mechanism. In WMNs, traditional FEC schemes, E2E-FEC and HbH-FEC, for video streaming are applied, but it has long transmission delay, high computational complexity and inefficient usage of resource. Also, to distinguish network status in streaming path, it has limitation. In this paper, we propose monitoring-based coordination of network-adaptive hop-to-end(H2E) FEC scheme. To enable proposed scheme, we apply a centralized coordinator. The coordinator has observing overall monitoring information and coordinating H2E-FEC mechanism. Main points of H2E-FEC is distinguishing operation range as well as selecting FEC starting node and redundancy from monitored results in coordination. To verify the proposed scheme, we perform extensive experiment over the OMF(Orbit Measurement Framework) and IEEE 802.1la-based multi-hop WMN testbed, and we carry out performance improvement, 17%, from performance comparison by existing FEC scheme.

• Journal of Korean Society of Transportation
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• v.30 no.1
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• pp.149-159
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• 2012

The evaluation of public transit service quality is more complicated than evaluating other aspects of transportation service. Although various measures of effectiveness [MOEs] for transit service have been studied and applied, a more comprehensive and accurate MOE is still required. In the past, either data from user surveys or the experience of bus agency administrators and/or engineers used to measure the quality of service. However, recently, with reliable and accurate real time data from BMS(Bus Management System) and BIS(Bus Information System), more reliable and accurate MOEs are available. This study develops a service evaluation model from users' perspectives, which is based on user' cost models that consider passenger access time, riding time, waiting time, and discomfort due to in-vehicle overcrowding, violation of traffic laws, and accident rate. For validating proposed model, data from the BMS and transit-fare cards (T-Money Card) for Seoul's No. 472 main bus line were used. Models developed in this study provided reliable results.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2022.06a
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• pp.88-90
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• 2022

For the quality management of software developed in Marine digital AtoN Information management and service system development project, an international standard-based quality process and a project management system-based communication and information sharing system were established. In addition, high-quality software development is achieved by monitoring the status of project output creation and supporting software quality inspection and verification.