• 한국지역지리학회지
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• 제21권1호
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• pp.39-61
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• 2015

이 논문은 도시 연계성에 관한 문헌들을 검토한 후 다중심도시지역의 개념과 분석기법을 제시하고, 이를 활용하여 영남권 도시들 간 화물통행량을 분석하여 도시 연계성과 다중심성을 고찰하고자 한다. 분석 결과, 영남권의 도시 네트워크는 흐름의 대칭성(즉 유입과 유출 통행량의 차이)에 있어 도시별로 상당한 차이를 보이지만, 엔트로피 지수로 보면 상대적으로 분산적인 흐름을 나타내고 있다. 또한 지배력 지수로 보면, 영남권 도시네트워크는 수도권에 비해 훨씬 다중심적(즉 비계층적) 특성을 보인다. 그러나 부산과 울산은 상대적으로 지배력 지수가 높고 이 도시들에 의존하는 연계도시들이 많은 반면, 대구는 지배력 지수가 상대적으로 낮고, 의존적 연계도시들의 수도 적게 나타난다. 결론적으로 제조업 부문별 화물 네트워크는 1위 도시인 부산을 중심으로 흐름이 집중하는 양상을 보이지만, 전반적으로 영남권 도시지역은 다중심도시지역의 특성을 상당히 보인다는 점에서, 다중심적 지역발전 정책이 권장될 수 있다.

• 한국공간정보시스템학회 논문지
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• 제8권3호
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• pp.105-115
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• 2006

데이타 중심 저장(Data-Centric Storage: DCS) 방식의 센서 네트워크는 같은 값의 데이타를 같은 노드에 저장하기 때문에 센서 네트워크가 확장되거나 같은 값의 데이타가 빈번하게 발생하면 특정 센서 노드에 저장 부하가 집중되어 에너지 효율성이 나빠지는 문제가 발생한다. 기존의 데이타 중심 저장 방식에 대한 연구들은 저장 데이타의 효율적인 관리에만 치우쳐 센서 네트워크의 확장에 따른 에너지 효율성 문제를 고려하지 않았다. 본 논문에서는 다차원 센서 데이타 저장의 효율적인 확장성(Scalability)을 지원하는 비균등 영역 분할(Non-Equal Region Spilt) 기법을 제안한다. 제안한 기법은 센서 네트워크를 센서 노드의 분포에 따라 같은 센서 노드 개수를 갖도록 서로 다른 크기의 영역으로 분할하고 분할된 각 영역 내에서 측정된 데이타를 해당 영역에서 저장 및 관리함으로써 센서 네트워크의 확장에 따른 저장 비용을 줄였다. 또한 분할 영역 개수를 센서 네트워크의 크기와 센서 노드 개수, 센서 데이타 발생량에 비례하게 증가시켜 센서 노드의 에너지 소모를 분산시킴으로써 센서 네트워크의 수명 연장과 확장성을 높였다.

• Smart Structures and Systems
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• 제32권1호
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• pp.49-59
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• 2023

A bridge transportation network supplies products from various source nodes to destination nodes through bridge structures in a target region. However, recent frequent earthquakes have caused damage to bridge structures, resulting in extreme direct damage to the target area as well as indirect damage to other lifeline structures. Therefore, in this study, a surrogate model-based comprehensive framework to estimate the seismic resilience of bridge transportation networks is proposed. For this purpose, total system travel time (TSTT) is introduced for accurate performance indicator of the bridge transportation network, and an artificial neural network (ANN)-based surrogate model is constructed to reduce traffic analysis time for high-dimensional TSTT computation. The proposed framework includes procedures for constructing an ANN-based surrogate model to accelerate network performance computation, as well as conventional procedures such as direct Monte Carlo simulation (MCS) calculation and bridge restoration calculation. To demonstrate the proposed framework, Pohang bridge transportation network is reconstructed based on geographic information system (GIS) data, and an ANN model is constructed with the damage states of the transportation network and TSTT using the representative earthquake epicenter in the target area. For obtaining the seismic resilience curve of the Pohang region, five epicenters are considered, with earthquake magnitudes 6.0 to 8.0, and the direct and indirect damages of the bridge transportation network are evaluated. Thus, it is concluded that the proposed surrogate model-based framework can efficiently evaluate the seismic resilience of a high-dimensional bridge transportation network, and also it can be used for decision-making to minimize damage.

• 제어로봇시스템학회논문지
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• 제9권5호
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• pp.361-367
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• 2003

We propose an algorithm to detect the face region using a variable ellipsoidal mask and a neural network. Since outlines of human faces are similar to ellipsoid, the ellipsoidal mask that has the fixed ratio of major and minor axis can be used to detect the candidate area. The positions of eyes and lips are extracted in this candidate area, and then the morphological analysis is applied to make features which are consist of six parameters, such as the geometrical ratio of eyes and lips. A back-propagation neural network is used as a classifier to determine the most possible face region. The experimental result is conducted to verify its efficiency compared with those of previous works.

• Journal of Ecology and Environment
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• 제30권4호
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• pp.331-340
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• 2007

We examined the evolutionary and ecological processes shaping current geographical distributions of a Korean wood-eating cockroach species, Cryptocercus kyebangensis. Our research aims were to understand evolutionary pattern of DNA sequences, to construct genetic network of Cryptocercus kyebangensis local populations and to understand evolutionary and ecological processes shaping their current geographical distribution patterns via DNA sequence information and genetic networks, using sequence data of two genes (ITS-2 and AT region) from local populations of C. kyebangensis. The results suggest that the ITS-2 and AT region are appropriate molecular markers for elucidating C. kyebangensis geographic patterns at the population level. The MSN-A based on the ITS-2 showed two possible routes, the Hwaak-san and Myeongji-san route and the Seorak-san and Gyebang-san route, for migration of ancestral C. kyebangensis into South Korea. The MSNs (MSN-A and -B) elucidate migration routes well within South Korea, especially the route of Group I and Group II.

• 한국정보과학회:학술대회논문집
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• 한국정보과학회 2011년도 한국컴퓨터종합학술대회논문집 Vol.38 No.1(A)
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• pp.491-493
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• 2011

Traffic sign detection is the domain of automatic driver assistant systems. There are literatures for traffic sign detection using color information, however, color-based method contains ill-posed condition and to extract the region of interest is difficult. In our work, we propose a method for traffic sign detection using k-means clustering method, back-propagation neural network, and projection histogram features that yields the robustness for ill-posed condition. Using the color information of traffic signs enables k-means algorithm to cluster the region of interest for the detection efficiently. In each step of clustering, a cluster is verified by the neural network so that the cluster exactly represents the location of a traffic sign. Proposed method is practical, and yields robustness for the unexpected region of interest or for multiple detections.

• 농촌지도와개발
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• 제23권3호
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• pp.309-320
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• 2016

This study has systematically classified established the agricultural management risks from the agricultural company's position and analyzed their counterplan situation in order to seek measures to counteract this. The AHP & IPA technique were used as an analysis method concerning the evaluation results. The counterplan situation was deduced through an interview investigation of 112 farmers who produce cabbage, white radish, onion, garlic, chili, and 6 other such items in order to stereotype the risks. If the agricultural companies' management capacity is raised in accordance to the risk counterplan deduced from this study, and the risks of agricultural management activity are avoided ahead of time or counter means are activated, we can anticipate the stabilization of agricultural management.

• ETRI Journal
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• 제36권4호
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• pp.625-634
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• 2014

This paper studies a dual-hop multiple-access relay network where two independent source nodes transmit information to a common destination node with the aid of multiple single-antenna amplify-and-forward relays. Each relay node is subject to an individual power constraint. We focus on the design of distributed beamforming schemes for the relays to support the transmission rate requirements of the two sources. To this end, we first characterize the achievable rate region for this network via solving a sequence of corner point optimization problems proposed in this paper. We also develop several low-complexity suboptimal schemes in closed form. Two inner bounds of the achievable rate region are theoretically shown to be approximately optimal in two special scenarios. Finally, numerical results demonstrate the effectiveness of our proposed approaches.

• 전자공학회논문지B
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• 제30B권10호
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• pp.86-94
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• 1993

This paper presents the two-stage neural network method for efficient channel assignment of cellular mobile radio network. The first stage decomposes the region into non-adjacent groups of cells and the second stage assigns channels to the decomposed groups. The neural network model is tested with an experimental system of eighteen channels dedicated for nineteen hexagonal-cell region. When radom call requests of average density of 2 Erl/Cell to 8 Erl/Cell are presented, the real-time channel assignment method reduces the call-blocking rate up to 16% against the existing SCA(Static Channel Assignment) method.

• Journal of Ecology and Environment
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• 제30권1호
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• pp.87-96
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• 2007

After introducing various aspects of the National Ecological Observatory Network (NEON) being planned and established in the US, the author tries to suggest the future direction for the development of similar activities of the NEON to be carried out in the region of East Asia including Korea. A review was carried out in terms of the challenges, major questions, missions, developmental history, and some other specifics of the NEON design. It was further extended to the discussion of the issues for the regional construction of the Ecological Observatory Network (EON) in East Asia. The author hopes that this review could be used as a preliminary guide in ultimately promoting and advancing research, science and technology in conservation and preservation of ecosystems being degraded due to anthropogenic disturbances in the region of East Asia.