• Journal of the Korean Society of Environmental Restoration Technology
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• v.13 no.5
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• pp.135-145
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• 2010

This study was carried out to investigate the current urban forest network and future plan of forest framework using nearest features program where stepping stones within 5km from the core forest were selected in the program. We found several conclusions as follows: First, we found that cities in inland area including Daegu, Dajeon and Gwangju have quite different types of forest network with comparing to the cities nearby coastline including Busan, Incheon and Ulsan. The cities in inland area have large mountain patch around each city. However they have small and lower number of island forests within their urban area. Otherwise, cities nearby coastline have more forest patches than in the cities in inland area, and Busan and Incheon especially have strong forest network using various size of forest patches. Second, Daegu and Daejeon have much smaller forest patches distributed in each urban area. So additional forest patches should be added to have highly strong forest network within urban area. Third, Ulsan and Gwangju have most stepping-stone forests close to the large mountain patches in suburban area, which are not able to connect to the forest patches in the central area of each city So additional forest patches are needed to be added in the central area of each city for reinforcing the effect of stepping stone in the central area. Though there should be an addition approach except for forest size and its isolation to construct the ecological network in an urban area, this indices can be a good method to check an environmental and ecological status in an urban area.

• Journal of Korean Society on Water Environment
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• v.32 no.5
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• pp.475-491
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• 2016

The Changwon and Nam streams that run through the Changwon city were evaluated based on longitudinal and horizontal configurations and vegetation state in order to prepare a restoration plan. Riparian vegetation of the Changwon and Nam streams are normally dominated by herbaceous plants. However, the woody plants, Salix pseudolasiogyne, Rubus parvifolius, Salix koreensis, Robinia pseudoacacia, and Amorpha fruticosa have appeared. Planting to introduce various types of plants for landscape architecture has also been observed. Evaluation of naturalness based on the vegetation state of both Changwon and Nam streams showed very low naturalness of degree 1 or 2, with the exception of a few reaches of the upstream sector. In these few reaches of the upstream sector, Salix koreensis and Salix chaenomeloides showed heights at the subtree level, however, they were located at the position of shrubland close to the waterway. These reaches were, therefore, evaluated as degree 3 rather than degree 4 in naturalness. The result of diagnostic evaluation classified by reach indicated the requirement for active restoration, such as transformation of the channelized stream into a meandering one and a step-type cross section into a pool-type one, introduction of vegetation suitable to the region and site, and creation of an ecological network between the stream and the surrounding terrestrial ecosystems.

• Journal of Electrical Engineering and Technology
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• v.1 no.4
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• pp.435-447
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• 2006

This paper presents an application of the parallel Adaptive Evolutionary Algorithm (AEA) to search an optimal solution of the service restoration in electric power distribution systems, which is a discrete optimization problem. The main objective of service restoration is, when a fault or overload occurs, to restore as much load as possible by transferring the de-energized load in the out of service area via network reconfiguration to the appropriate adjacent feeders at minimum operational cost without violating operating constraints. This problem has many constraints and it is very difficult to find the optimal solution because of its numerous local minima. In this investigation, a parallel AEA was developed for the service restoration of the distribution systems. In parallel AEA, a genetic algorithm (GA) and an evolution strategy (ES) in an adaptive manner are used in order to combine the merits of two different evolutionary algorithms: the global search capability of the GA and the local search capability of the ES. In the reproduction procedure, proportions of the population by GA and ES are adaptively modulated according to the fitness. After AEA operations, the best solutions of AEA processors are transferred to the neighboring processors. For parallel computing, a PC cluster system consisting of 8 PCs was developed. Each PC employs the 2 GHz Pentium IV CPU and is connected with others through switch based fast Ethernet. To show the validity of the proposed method, the developed algorithm has been tested with a practical distribution system in Korea. From the simulation results, the proposed method found the optimal service restoration strategy. The obtained results were the same as that of the explicit exhaustive search method. Also, it is found that the proposed algorithm is efficient and robust for service restoration of distribution systems in terms of solution quality, speedup, efficiency, and computation time.

• ETRI Journal
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• v.24 no.2
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• pp.69-81
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• 2002

This paper reviews the existing research activities on signaling and control procedures for IP over optical networks. We focus on the IP-centric signaling and control architecture based on the generalized multi-protocol label switching (GMPLS) protocol and analyze various scenarios and technical issues for deploying the IP over an optical network. We analyze the signaling and operations and administration and maintenance requirements for integrating an IP network and an optical network in order to cope with the high bandwidth and poor resource granularity of the optical network, including the optical cross-connect system. On the basis of network architecture and a reference configuration model, we investigate the GMPLS-based control architecture and interconnection model appropriate for controlling IP bandwidth and optical lambda resources. The signaling and control procedure based on GMPLS on optical user-network interface and network-network interface are comparatively investigated to provide the optical lightpath. We also study protection and restoration procedures to protect link failure when it applies to generalized MPLS signaling.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.10 no.6
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• pp.70-80
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• 2007

This study was surveyed from January to september, 2007 in order to evaluate the function of coastal wetland as a ecological axis in korea peninsula. Assessment was done by RAM (Rapid Assessment Method). RAM is consisted of total 8 contents and divided into high, moderate, low. The preservation grade of RAM is divided into 4 grades; absolute preservation, preservation, improvement and improvement or restoration. Throughout survey on total 14 wetlands of marine, estuary wetland and back marsh which are distributed in west coast in chung-nam province, their function was assessed. As result, total all the 14 wetlands were judged as preservation grade by assessment of 8 functional contents. The function of wetlands assessed as preservation grade showed high in water quality protection and improvement. Also, showed high in vegetation diversity, wildlife habitat and aesthetic recreation. Meanwhile, showed low in ground water recharge, Shoreline/Stream Bank Protection, Flood/Stormwater storage and Flood flow alteration. Of wetlands evaluated as preservation grade, Dae-ho, Sinduri, Bu-Nam lake, Sowhang dune and keum river estuary were assessed as absolute preservative area owing to habitation of international protection species and endangered species. These wetlands are essential to be managed continuously as a area having high ecological value. Farther, this wetlands will be done as a axis of ecological network related to land ecosystem.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.24 no.5
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• pp.25-34
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• 2021

Increase in avian species richness is one of the important issues of urban biodiversity policies, since it can promote diverse ecosystem services such as seed dispersal, education, and pollination. However, though human disturbance can significantly affect avian species richness, there are limited studies on the way to reflect the dynamics of floating population. Therefore, this study analyzed the spatial relationship between avian species richness, floating population, and vegetation cover using telecommunications information to identify the areas that requiring targeted monitoring and restoration action. Bivariate Local Moran's I was applied to identify LISA cluster map that showing representative biotopes, which reflect significant spatial relationship between species richness and population distribution. Edge density and distribution of ndvi were identified for evaluating relative adequacy of selected biotopes to strengthen the robust biodiversity network. This study offers insight to consider human disturbance in spatial context using innovative big data to increase the effectiveness of urban biodiversity measures.

• Journal of Information Processing Systems
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• v.19 no.6
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• pp.858-869
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• 2023

As one of the pivotal techniques of image restoration, single-channel blind source separation (SCBSS) is capable of converting a visual-only image into multi-source images. However, image degradation often results from multiple mixing methods. Therefore, this paper introduces an innovative SCBSS algorithm to effectively separate source images from a composite image in various mixed modes. The cornerstone of this approach is a novel triple generative adversarial network (TriGAN), designed based on dual learning principles. The TriGAN redefines the discriminator's function to optimize the separation process. Extensive experiments have demonstrated the algorithm's capability to distinctly separate source images from a composite image in diverse mixed modes and to facilitate effective image restoration. The effectiveness of the proposed method is quantitatively supported by achieving an average peak signal-to-noise ratio exceeding 30 dB, and the average structural similarity index surpassing 0.95 across multiple datasets.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.56 no.3
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• pp.443-450
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• 2007

We overview the current distribution automation system in Korea and point out the limitations of the distribution services which can be provided by the current system. In this paper we propose a new distribution system architecture which is based on the peer-to-peer communication model. In this decentralized architecture the intelligent FRTUS can initiate data transmission without any interruption of a central server, and can exchange data with other FRTUS as peers. In order to support the peer-based distribution system, we specify the requirements for new communication network and suggest a way of improving the current distribution network where we adapt an intelligent module for protection and restoration, called MASX, and utilize the open communication network protocols. We also show how the new architecture can enhance major distribution services such as protection, automatic restoration, and equipment management.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.62 no.7
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• pp.913-917
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• 2013

During the restoration process of primary restorative transmission system, some over voltages may happen due to nonlinear interaction between unloaded transformers and transmission systems. These over voltages caused by harmonic resonance can be suppressed by inserting damping loads before energizing transformers. But it is very difficult to predict the occurrence possibility of harmonic resonance and complex simulation must be repeated to estimate the sufficient damping loads. This paper presents a damping loads prediction system to prevent harmonic resonance. Detailed analysis of the relationship between harmonic resonance and the amount of damping loads is discussed. The prediction system is developed using a curve fitting and a neural network based on this relationship. A curve fitting used a Gaussian function based on non-linear least square method and multi-layer back-propagation neural network is applied. The system is applied to primary restorative transmission lines in korean power system and the result showed satisfactory performance.

• Proceedings of the Korea Information Processing Society Conference
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• 2002.11b
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• pp.1595-1598
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• 2002

네트워크 장애로 인한 인터넷 서비스 품질의 저하는 사용자와 서비스 제공자에게 여러 가지 형태로 손실을 가져오므로 망의 우회경로 설정 및 복구방안은 중요한 요소가 되고 있다. 망 복구에 있어서 중요한 과제는 작업 경로(working path)에 대한 복구 경로(restoration path)를 설정하는 것이다. 장애가 발생하더라도 서비스의 중단이 없도록 하기 위해서는 복구 경로를 설정할 때 작업 경로의 대역을 보장할 수 있는 복구 경로를 실정해야 한다. 이를 위해 MPLS망에서는 명시적 Routing기법에 기반을 둔 Constraint-based routing이 제안되었고 또한 망의 경로 복구를 위해 정적 및 동적설정기법이 제안되고 있다. 본 논문에서 제안된 방식은 확장된 OSPF 프로토콜의 TE-LSAs를 이용하여 또 다른 virtual 망을 구성하고 기본경로 중간의 TE-LSR을 새로운 PIL로 설정하여 빠른 대체 LSP를 설정 및 복구하는 기법을 성능 비교를 통해 망 자원의 효율적 사용을 보고자 한다.