• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.34 no.5
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• pp.525-534
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• 2016

In South Korea, paddy rice has been consumed over the entire region and it is the main source of income for farmers, thus mathematical model for the estimation of rice yield is required for such decision-making processes in agriculture. The objectives of our study are to: (1) develop rice yield estimation model using Convolutional Neural Networks(CNN), (2) choose hyper-parameters for the model which show the best performance and (3) investigate whether CNN model can effectively predict the rice yield by the comparison with the model using Artificial Neural Networks(ANN). Weather and MODIS(The MOderate Resolution Imaging Spectroradiometer) products from April to September in year 2000~2013 were used for the rice yield estimation models and cross-validation was implemented for the accuracy assessment. The CNN and ANN models showed Root Mean Square Error(RMSE) of 36.10kg/10a, 48.61kg/10a based on rice points, respectively and 31.30kg/10a, 39.31kg/10a based on 'Si-Gun-Gu' districts, respectively. The CNN models outperformed ANN models and its possibility of application for the field of rice yield estimation in South Korea was proved.

• Electronics and Telecommunications Trends
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• v.5 no.4
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• pp.12-41
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• 1990

본고는 자연적인 현상의 번개와 같은 서어지로 인해 야기되는 각종 위해(Harm)로부터 전기통신회선을 보호하기 위해, 세계 각국에서 규정하고 있는 서어지 기술기준의 동향을 분석하여 우리나라가 대처해 나가야 할 방향을 찾고자 한 것이다.

• Electronics and Telecommunications Trends
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• v.7 no.4
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• pp.71-88
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• 1992

전기통신 회선의 2 선 선로 임피던스와 하이브리드 회로의 평형 결선망과의 임피던스 부정합에 의한 반사손실의 영향을 파악하고 과도한 중계기 이득과 이들 임피던스 부정합으로 인한 통신망의 위해요소인 명음의 발생 배경과 명음 발생 방지를 위한 세계 각국의 관련기준 및 측정법을 조사 분석한다.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.11 no.5
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• pp.297-306
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• 1986

This paper surveys circuit switching local area networks(LANs) whit topology of ring, mesh, bus and star. Emphasis of this study is given on the conceptual switching technologies of these LANs.

• Journal of Scientific & Technological Knowledge Infrastructure
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• s.4
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• pp.66-73
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• 2001

본 고에서는 인터넷에서 가장 많이 사용하는 Web을 근거로 하여 웹 사이트를 설계할 때 응답시간과 관련해서 고려되어야 할 요소 중 인터넷 연결 회선의 대역폭 결정에 참조될 수 있는 자료를 제시한다.

• 정보화사회
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• s.38
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• pp.50-56
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• 1991

신부는 최근 민간 VAN업체에 대한 국제 VAN의 조기 허용등 사업영역 확대와 정보통신사업 육성자금의 조기지원, 통신회선의 고속화, 정보통신기술 개발과 표준화의 강화, 통신회선요금의 감면등을 포함한 정보통신육성계획을 발표했다. 체신부가 세계적인 서비스교육의 자유화추세에 대응해 그동안 민간업체들의 요구를 전폭 수용한 동계획 전반을 소개한다.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.38 no.6
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• pp.28-38
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• 2001

In this paper, we propose and analyze a more efficient and flexible dynamic data traffic system for a circuit switched satellite network. Our proposed system is more efficient than existing circuit switched satellite networks and allows for dynamic capacity in each connection without rebuilding or resetting the connection software or algorithms. We also discuss an algorithm for bandwidth allocation that provides deterministic quality of service guarantees. The traffic sources are regulated using standard dual leaky buckets; the system performance is analytically evaluated; and the algorithm is verified through simulation. Our analysis scheme and results should prove useful for the design and implementation of protocols in future circuit-switched satellite networks.

• The KIPS Transactions:PartC
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• v.15C no.5
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• pp.367-374
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• 2008

To realize the voice privacy between CDMA mobile phone and PSTN terminal, the voice frames shall be transmitted transparently between the heterogeneous networks. For satisfying this requirement, we propose the method which transmits voice frames using the CDMA circuit data channel in real time. In this paper we analyze the causes of voice delay which occurs during voice transmission using circuit data channel. And in order to overcome this kind of delay, the technique controlling the TCP control flag and the variable audio block construction algorithm according to the vocoder output rate are proposed. As a result of experimenting by applying the proposed method, we confirmed that the transit delay was improved with about average 70%.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.17 no.5
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• pp.452-459
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• 1992

In this paper, we have estimated voice traffics using Kalman-filtering for upcoming years and evaluated performance of a grid topology circuit switched network using above outcomes. Since measurement errors and modeling errors are considered in Kalman-filtering, the system is estimated more accurately than by using any other estimation methods. A grid topology circuit switched network has alternative routing paths, therefore it is more reliable than any other networks. In this paper, we have calculated the call blocking probabilities, which is the key measuremens of performance evaluation in circuit switched networks. by using estimated voice traffics for upcoming years.

• The Journal of Korean Association of Computer Education
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• v.11 no.5
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• pp.57-66
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• 2008

An adaptive optimization of parametric cubic convolution for image interpolation is derived in this paper. The proposed technique is based on optimizing the standard cubic convolution interpolation formula at each interpolated pixel. Conventional parametric cubic convolution methods use a fixed parameter in an image, so properties of each pixel cannot be incorporated into the interpolation. The proposed method optimizes the interpolation kernel by obtaining parameters adaptively on each pixel. A new cost function is introduced to reflect frequency properties of the original data. The proposed technique produces noticeably sharper edges than traditional techniques and exhibits an average PSNR improvement of traditional techniques.