• 한국정보통신설비학회:학술대회논문집
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• 2003.08a
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• pp.112-114
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• 2003

MPLS/VPN서비스는 MPLS망의 인프라를 이용하여 사설망을 제공하는 서비스로 각 VPN사이트사이를 고속의 LSP를 이용하여 연결한다. MPLS/VPN서비스는 차별적인 다양한 서비스 품질을 지원하는 것이 용이하며, 또한 서비스 도입과 운용 및 관리가 용이하여 저비용으로 VPN서비스를 제공할 수 있는 장점을 가지고 있다. 본 논문에서는 초고속 국가망에 도입될 예정인 ATM/MPLS MSR40시스템을 이용하여 MPLS/VPN망을 구축하기 위해 요구되는 라우팅 프로토콜상에서의 설정 및 고려사항을 설명한다. 현재 시험서비스중인 MPLS네트워크 구축 사례를 바탕으로 하여 MPLS 도메인 내부 라우팅 설정 절차 및 가입자측 라우팅 설정 절차에 대해 설명하고 또한 MPLS망의 특성상 요구되는 몇가지 라우팅 이슈에 대해 설명한다.

• Journal of the Korean Institute of Telematics and Electronics
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• v.21 no.1
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• pp.13-24
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• 1984

This paper presents the measurements and analyses of transmission qualities of the existing urban and toll public switching telephone network (PSTN) for the purllose of opening it to data transmission. In the tests, random noise and impulsive noise occuring on the telephone network are investigated and bit error rate and block error rate representing the transmission qualities on the existing telephone network are measured. We recommend the fastest practical data transmission speed on the network and investigate a possibility of opening the public switching telephone network (PSIN) to the data transmission based on the above measurements.

• Journal of the Korean Geotechnical Society
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• v.21 no.8
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• pp.73-84
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• 2005

A three layered neural network model was developed using back propagation algorithm to estimate the UU undrained shear strength of Korean soft soil based on the database of actual undrained shear strengths and piezocone measurements compiled from 8 sites over the Korea. The developed model was validated by comparing model predictions with measured values about new piezocone data, which were not previously employed during development of model. Performance of the neural network model was also compared with conventional empirical methods. It was found that the number of neuron in hidden layer is different for the different combination of transfer functions of neural network models. However, all piezocone neural network models are successful in inferring a complex relationship between piezocone measurements and the undrained shear strength of Korean soft soils, which give relatively high coefficients of determination ranging from 0.69 to 0.72. Since neural network model has been generalized by self-learning from database of piezocone measurements and undrained shear strength over the various sites, the developed neural network models give more precise and generally reliable undrained shear strengths than empirical approaches which still need site specific calibration.

• The Korean Journal of Malacology
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• v.24 no.2
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• pp.131-136
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• 2008

Growth and survival of the spat of arkshell, Scapharca broughtonii were investigated for the improvement of survival in intermediate culture with different shape of protective net and type of preventive net of spat loss. The growth performance of the spat of arkshell was observed for 60 days by using different forms of protective net, as the exposure form with an average shell length of $12.8{\pm}3.2$ mm(P<0.05), the fish pot form with $12.2{\pm}3.5$ mm, the cylinder form with $11.9{\pm}3.8$ mm and the last one is the rectangular form with $10.9{\pm}3.7$ mm. Their numerical value did not show any marked difference with each other. But in case of survival rate, the fish pot form showed highest survival rate which is 43.7% and the significantly lowest was showed by the exposure form, which is 5.4%(P<0.05). The cylinder form and rectangular form showed 41.2 and 31.6% respectively. And then the growth of the spat of arkshell was observed for 163 days by rearing in a sort of preventive net, the first group was in a blackout curtain with average shell length of $13.9{\pm}3.1$ mm, the next group was in a balsam pear net with $12.9{\pm}3.0$ mm, in a polyethylene net with $11.8{\pm}3.1$ mm and the control with $12.6{\pm}3.3$ mm which was not installed by preventive net of spat loss. The survival rate was 91.5% in a blackout curtain, 90.1% in a polyethylene net, 88.5% in a balsam pear net and 61.5% in a controlled group. It is seen that the highest growth and survival rate were observed in a fish pot form and cylinder form. These results were a little bit difference from those of the spat of arkshell cultured in the form of different preventive nets. There was no significant difference in survival rate in relation to the sorts of preventive net against carrying-away, but there was a difference in survival rate by more than 30% as against the non-installed controlled group. We expect that survival rate would be highly improved in intermediate culture carried out with fish pot form and cylinder form of protective net and preventive net of spat loss.

• Proceedings of the Korean Information Science Society Conference
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• 2001.10c
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• pp.169-171
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• 2001

38GHz 밀리미터파의 국내 적용을 위한 서울지역의 전파환경시험을 통한 적정거리 도출을 위한 기초 Data를 수집하여 전파환경시험을 수행함으로써 기후 및 적응거리등에 따른 기술자료 확보 및 적정거리 도출을 통하여 전송망 구축 설계시 반영하고자 한다.

• Digital Contents
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• no.5 s.132
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• pp.74-74
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• 2004

한국소프트웨어진흥원(KIPA)은 지난달 13일 유렵형 국제표준 상용 무선통신(GSM,GPRS)시험망을 갖춘 모바일테스트베드 개통식을 가졌다. 이날 개통식에는 최재유 정보통신부 지식정보산업과정, 서병문 한국문화콘텐츠진흥원장, 고시연 한국중소벤처기업연합회장을 비롯해 노세용 LG텔레콤 상무, 박성찬 다날 사장, 최충엽 신지소프트 사장 등 관련인사 70명이 참석 자리를 빛냈다.

• Information and Communications Magazine
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• v.12 no.12
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• pp.114-131
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• 1995

본 고에서는 B-ISDN망을 구성하는 요소로서의 ATM 교환기의 역할에 대하여 논하였다. 또 이를 위한 ATM 교환기의 구조, 동작, QoS 등에 대하여 기술하였으며, HAN/B-ISDN 프로젝트의 일환으로 ETRI에서 개발 중인 ATM 교환기의 품질, 성능 및 운용 예에 대하여 논하였다. 시험 결과에 의하면 개발된 ATM 교환기는 정상 상태하에서 고품질을 유지하고 안정되게 동작함을 알 수 있다.

• Journal of Bio-Environment Control
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• v.29 no.4
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• pp.448-455
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• 2020

This study was carried out to investigate reduction of the frost damage using the mesh net used for the purpose of non-bagged cultivation. A device measuring the weight of frost was developed and installed in both the control and the experimental, and the effect of frost reduction was evaluated with their weights. As a result, weight of frost in the control was reduced from 37% to 59% with mesh net on the day the frost was observed. In addition, the device for automatically observing the amount of frost was developed and the height of the windbreak of the frost measuring device was determined to be 30 cm through wind tunnel experiment. The results of this study are expected to reduce frost damage during the flowering season of fruit trees by installing mesh net and it is expected to be used as basic data for agricultural use of mesh net.

• Magazine of the Korea Concrete Institute
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• v.9 no.2
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• pp.145-151
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• 1997

In concrete mix design we need the informations of the codes, the specifications, and the experiences of experts. However we can't consider all factors regarding concrete mix design. The final acceptance depends on concrete quality control test results. In this process we meet the uncertainties of materials. temperature, site environmental situations, personal skillfulness. and errors in calculations and testing process. Then the mix design adjustments must be made. Concrete mix design and adjustments arc somewhat complicated, time-consuming. and uncertain tasks. In this paper, as a tool to minimize the uncertainties and errors the neural network is applied to the concrete mix design. Input data to train and test the neural network are obtained numerically from the results of design following the concrete standard specifications of Korea. The 28-days compressive strengths which are variate according to the uncertainties and errors are considered. The results show that neural networks have a strong potential as a tool for concrete mix design.

• Journal of the Korea institute for structural maintenance and inspection
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• v.24 no.3
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• pp.18-25
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• 2020

The unconfined compressive strength of lightweight treated soils strongly depends on mixing ratio. To characterize the relation between various LTS components and the unconfined compressive strength of LTS, extensive studies have been conducted, proposing normalized factor using regression models based on their experimental results. However, these results obtained from laboratory experiments do not expect consistent prediction accuracy due to complicated relation between materials and mix proportions. In this study, deep neural network model(Deep-LTS), which was based on experimental test results performed on various mixing conditions, was applied to predict the unconfined compressive strength. It was found that the unconfined compressive strength LTS at a given mixing ratio could be resonable estimated using proposed Deep-LTS.