이질적 경관에서의 연결성 측정: 리뷰 및 적용

송원경 ( Won Kyong Song ),김은영 ( Eun Young Kim ),이동근 ( Dong Keun Lee ) 한국환경영향평가학회 2012 환경영향평가 Vol.21 No.3

The loss of connectivity and fragmentation of forest landscapes are seriously hindering dispersal of many forest-dwelling species, which may be critical for their viability and conservation by decreasing habitat area and increasing distance among habitats. For understanding their environmental impacts, numerous spatial models exist to measure landscape connectivity. However, general relationships between functional connectivity and landscape structure are lacking, there is a need to develop landscape metrics that more accurately measure landscape connectivity in whole landscape and individual patches. We reviewed functional and structural definition of landscape connectivity, explained their mathematical connotations, and applied representative 13 indices in 3 districts of Seoul having fragmented forest patches with tits, the threshold distance was applied 500m by considering the dispersal of tits. Results of correlation and principal component analysis showed that connectivity indices could be divided by measurement methods whether they contain the area attribute with distance or not. Betweenness centrality (BC), a representative index measuring distance and distribution among patches, appreciated highly stepping stone forest patches, and difference of probability of connectivity (dPC), an index measuring including area information, estimated integrated connectivity of patches, Therefore, for evaluating landscape connectivity, it is need to consider not only general information of a region and species` characteristics but also various measuring methods of landscape connectivity.

안정기 뇌파를 이용한 기능적 연결성 분석

김헌민(Hunmin Kim),황희(Hee Hwang) 대한소아신경학회 2018 대한소아신경학회지 Vol.26 No.3

Advances in network science and computer engineering have enabled brain connectivity analysis using clinical big data such as brain magnetic resonance imaging (MRI), electroencephalography (EEG), or magnetoencephalography (MEG). Resting-state functional connectivity analysis aims to reveal the characteristics of functional brain network in various diseases and normal brain maturation using resting-state EEG. Simplified sequence of resting-state functional connectivity analysis methods will be reviewed in this article. The outcomes from EEG resting-state connectivity analysis are comprised of connectivity itself of the specific condition and the network topology measure which describe the characteristics of specific connectivity. An increasing number of studies report the differences in the functional connection itself, global network measures including segregation (connectedness), integration (efficiency), and importance of specific nodes (centrality or node degree). Several issues that are relevant in the resting-state connectivity analysis are obtaining good quality EEG for analysis, consideration of particular features of EEG signal, understanding different types of association measures, and statistics for comparison of connectivities. Well-designed and carefully analyzed EEG resting-state connectivity analysis can provide useful information for patient care in pediatric neurology.

국내 7대 광역시 산림 연결성 비교 분석

강완모 ( Wanmo Kang ),김지원 ( Jiwon Kim ),박찬열 ( Chan Ryul Park ),성주한 ( Joo Han Sung ) 한국농림기상학회 2014 한국농림기상학회지 Vol.16 No.2

This quantitative research aims to examine the connectivity of forest networks in seven metropolitancities of South Korea using a graph-theoretical approach. We first estimated an overall networkconnectivity at multi-scales (i.e., dispersal distances), ranging from 100 m to 20 km, and quantified thecontribution of small forest patches (less than 10 ha) to the overall network connectivity by comparingnetworks according to the presence and absence of small ones. As a result, the cities were divided intotwo groups depending on the network connectivity; one group of cities with high connectivity such asDaegu, Daejeon, and Ulsan and the other group of cities with low connectivity including Gwangju, Busan, Seoul, and Incheon. The result showed that small forest patches, especially in the cities withlow connectivity, played a key role as stepping stones that connect large forested patches, therebycontributing to maintaining connectivity. This study also suggests that large and well-connected forestareas may be the key factor to preserve the connectivity in the cities with high connectivity, while thecites with low connectivity are in need of some complementary strategies. Through the study, wesuggest that the creation of new forest patches in the areas where a gap in connectivity presents isneeded in order to improve connectivity; and that the conservation of the existing small forest patchesis essential in order to maintain the current connectivity level.

교통물류거점의 네트워크 연계성 개선효과 분석 방법론

박준식,강성철,김거중 대한교통학회 2010 대한교통학회지 Vol.28 No.6

This study proposes a methodology for assessing the improvement of network connectivity of transport hubs. Extending a previously developed model that measures the connectivity of a node in transportation networks, we define two quantities called the supplied connectivity and the experienced connectivity. Using these quantities, we provide a systematic procedure for analyzing the network connectivity of a transport hub and also suggest criteria for determining whether a given project is effective in improving the network connectivity of the transport hub. The application of the methodology to a test site produces reasonable results, and as such it is expected that the methodology can be used for various transport hubs in the national road network. Once enough data from the application of the methodology are accumulated, a further study on the level of service in terms of network connectivity needs to be followed. 본 연구에서는 교통물류거점의 네트워크 연계성 개선효과를 분석하기 위한 방법론을 제시하였다. 기존에 개발된 노드의 연계성 산출 모형을 사용하여 공급 연계성과 체감 연계성을 정의하였고, 교통물류거점의 네트워크 연계성 분석 범위와 분석 대상 노드 설정 알고리즘을 제시하였다. 또한 교통물류거점의 네트워크 연계성 개선효과 분석 과정을 체계화하였으며, 연계성 개선사업의 효과평가 방법 및 기준을 제시하였다. 방법론을 사례 연구에 적용한 결과 적절한 결과를 도출하였으며 전국 도로 네트워크에 실제 적용 가능하다고 판단된다. 교통물류거점의 네트워크 연계성 분석 결과 값들이 어느 정도 축적된 이후에는 네트워크 연계성의 서비스수준을 판단하기 위한 추가 연구가 필요하다.

Factors Affecting Infrastructure Connectivity: An Indian and Vietnamese Perspective

Thuy T.Dang,Nguyen Le Thy Thuong,Pham Thuy Nguyen 한국외국어대학교 인도연구소 2021 남아시아연구 Vol.27 No.3

Infrastructure connectivity plays an important role in Vietnam and India’s trade promotion, and international economic development and cooperation. Vietnam and India have become comprehensive strategic partners since 2016. In its “Act East” Policy, India considered Vietnam as a crucial destination for infrastructure development, trading and investment projects as well as a bridge to connect India with the Southeast Asia region. The article presents direct factors affecting infrastructure connectivity between India and Vietnam, in different aspects including geography and nature; politics and diplomacy; finance and economics; institutional policies and regulations; society and people; and infrastructure. From analyzing these factors, it can be seen that the harmonious diplomatic relations, stable internal politics and the increase in cooperation between Vietnam and India in various fields contribute to ensuring Vietnam - India infrastructure connectivity cooperation. A young, highly skilled workforce and a strong culture of integration also create favorable conditions for infrastructure connectivity between the two countries. However, the remote geographical distance, the limited economic resources, the relative disparity in the level of development of hard and soft infrastructure as well as the limited institutional capacity of each country create certain barriers. Due to the delay in decision-making and planning between the two countries, no direct projects between the two countries have been implemented so far. Currently, it is only possible to place the Vietnam - India infrastructure connectivity projects in the ASEAN - India infrastructure connectivity network, but most of these projects also stop at drafting and planning phase. Therefore, the infrastructure connectivity between Vietnam and India needs to overcome many barriers to achieve certain results.

인천국제공항의 환적화물에 대한 연계성 분석 연구

김중엽,박용화 대한교통학회 2008 대한교통학회지 Vol.26 No.5

After the deregulation of the aviation market in the United States in 1978, airlines took advantage of the possibilities of the liberalized market and reorganized their networks. Then, the hub-and-spoke networks became widely used in the aviation market. The framework of hub-and-spoke network made it feasible to amplify flight networks. Thus, a number of airlines were able to fly to more destinations than ever before through the networks. Amplification of networks can be implementing through the transfer of passengers, transshipment of cargo, or both most researches have been concentrated on the passenger aspect at airports worldwide. Air cargo, however, has become one of the most significant areas at hub airports to keep their leading position in terms of the provision of services and handling volumes. This paper investigates the connectivity of airfreight networks as the temporal concentrations in current network at Incheon International Airport. In order to evaluate airline flight schedule effects to stimulate hubbing at an airport, the indirect connectivity can be considered to be the number of direct frequencies, the minimum connecting times and the quality of the connection determine indirect connectivity. Therefore, the connectivity of freight transshipment depends on both the quality of the connection at the hub airport and the quality of the indirect flight compared to the direct flight. In addressing these issues, this paper analyzes the connectivity of flight schedules using a temporal wave-system structure and estimates the degree of connectivity and quality of connectivity applying the NETSCAN model. 1978년 미국 내 항공시장의 규제완화와 함께 항공은 허브-앤-스포크 시스템(hub-and-spoke system)의 형태로 재구성되었다. 항공의 확장성을 중점적으로 고려할 때, 허브-앤-스포크의 활용은 여객의 환승이나 화물의 환적에 있어서 어느 정도의 이점이 존재한다는 것이 일반적인 견해이다. 또한 국가 차원으로 볼 때, 허브-앤-스포크를 통해 공항의 활성화 및 노선에 따른 밀도의 경제를 실현하도록 허브공항을 개발하는 정책적 지원의 동기가 될 수도 있다. 기존 선행연구들은 대다수 항공여객에 대한 연구들로 집중되어 왔으나 항공환적화물에 대한 연구는 그 수가 상대적으로 적게 나타났다. 이에 본 연구에서는 인천국제공항을 대상으로 하여 항공화물의 환적연계성에 대한 분석을 통해 허브-앤-스포크 상에서 과연 허브공항으로서의 기능과 성과를 수행하고 있는지를 측정코자 하였다. 이를 위한 연구의 범위는 인천국제공항을 통해 환적 되는 항공화물을 대상으로 하며, 개설 가능한 환적노선인 직항연결 및 우회연결(Direct and Indirect Connection)로 한정하였다. 인천국제공항을 기반으로 한 항공화물의 환적연계성을 분석하기 위해 인천국제공항과 연결된 공항들의 노선 수나 연결시간 등을 기준으로 하여 직항연결과 우회연결의 품질을 평가하는 방식으로 취하였다. 이를 위해 공항의 웨이브-시스템 구조를 분석하여 활용하는 NETSCAN 모델을 적용하였다.

도시철도역의 네트워크 연계성 분석

박준식,강성철 한국교통연구원 2011 交通硏究 Vol.18 No.1

The service level of the transit supply can be evaluated in several ways. In this study, the network connectivity of urban metro stations is analyzed as a measure to reflect their service level. The previously suggested connectivity analysis model for multimodal transit networks is employed to calculate the network connectivity of urban metro stations in Korea. The results show that the difference in the network connectivity between lines is large, while the network connectivity of individual stations within a line is similar. While the network connectivity of Seoul metropolitan line 1 is the highest without considering transfer, if transfer is considered, the network connectivity of Seoul metropolitan line 2 shows the highest value. This is because there exist many transfer stations in Seoul metropolitan line 2 compared to other lines. While Seoul metropolitan line 6, line 8, line 9, and Jungang line have small network connectivity, they are connected to the lines with high network connectivity. These lines serve a role of connecting main lines in the network. 대중교통 서비스의 공급수준은 여러 가지 관점에서 평가할 수 있는데, 본 연구에서는 네트워크 연계성의 관점에서 도시철도역의 서비스 공급수준을 분석하였다. 기존에 제시된 복합수단 대중교통 네트워크 연계성 분석모형을 활용하여 도시철도역의 네트워크 연계성을 산출하였다. 역별로 산출된 네트워크 연계성을 분석한 결과 노선별로 연계성의 차이가 두드러진 반면, 노선 내의 역별로는 차이가 크지 않음을 확인하였다. 환승을 고려하지 않을 경우 수도권 1호선의 연계성이 가장 높게 나타나는 반면, 환승을 고려할 경우에는 수도권 2호선의 연계성이 가장 높게 나타나, 수도권 2호선에 환승역이 많고 그로 인한 연계성의 증가가 큰 것을 알 수 있었다. 또한 환승으로 인한 연계성 증가비율을 분석한 결과 수도권 6호선, 8호선, 9호선, 중앙선은 노선 자체의 연계성은 크지 않으나 연계성이 높은 노선과 잘 연계되어 있어, 이들 노선은 네트워크 차원에서 주요 노선들을 연계하는 기능이 큰 것을 알 수 있었다.

과학적 가설평가 과정의 뇌 과학적 분석방법 고찰-Effective connectivity 중심으로-

이일선,권용주 한국교원대학교 뇌기반교육연구소 2011 Brain & Learning Vol.1 No.1

이 연구의 목적은 과학적 가설평가 과정의 뇌 과학적 분석 방법을 effective connectivity 분석 방법 중심으로 고찰해보는 것이다. 분석 방법을 고찰해보기 위해, 이 연구는 두뇌 네트워크 분석 방법과 관련된 선행연구들로부터 effective conncectivity의 3가지 분석방법을 확인하였다: PPI, SEM, DCM. 첫 번째로, 각 항목에 관련된 분석 방법을 파악하기 위하여 connectivity 분석 방법에 대한 15편의 뇌과학 문헌들을 분석하였다. 두 번째로, 과학적 가설평가 과정의 하위 요소들과 관련된 연구들 중 effective connectivity 분석 방법을 사용한 30편의 뇌과학 문헌들을 분석하였다. 그 결과, 과학적 가설평가 과정의 뇌과학적 연구에는 functional connectivity 분석보다 effective connectivity분석이 보다 적절한 것으로 나타났다. 또한 가설평가 과정의 하위 인지요소별 실험결과는 PPI분석을 통해 ROIs를 구성하고 구성된 ROIs들을 SEM을 이용하여 경로 모델을 도출하는 것이 최적의 분석 방법임을 확인하였다. 이러한 분석 방법들은 과학탐구의 다른 하위 과정들의 분석에도 활용 가능할 것으로 전망된다. The purpose of this study was to review how the brain scientific analysis in scientific hypothesis evaluation with a focus on the effective connectivity. To review how the brain scientific analysis, we have found 3 methods of effective conncectivity from previous studies: PPI, SEM, DCM. Firstly, Fifty literatures on the brain network associated connectivity analysis were analyzed to know the characteristic which is related to three methods. Secondly, thirty literatures associated with the sub-element of the hypothesis evaluation process using effecitve connecitivity analysis methods were evaluated. As a result, effective connectivity analysis showed that a more appropriate analysis of functional connectivity. In addition, the PPI analysis consist of ROIs, to derive SEM model using ROIs was the best analysis method. These analysis methods are expected to be utilized in other scientific inquiry process.

An Inquiry into Synergies and Tensions between the EU Connectivity Strategy for Asia and China’s Belt and Road Initiative

Constantin Holzer,Eun-Hye Lee 동아시아무역학회 2021 Journal of East Asian Trade(JEAT) Vol.3 No.2

Purpose – The purpose of this paper is to offer a systematic comparison between the EU Connectivity Strategy and China’s Belt-and-Road Initiative (BRI), the world’s two most significant connectivity plans for economic development. Design/Methodology/Approach – Based on a comparative approach, the paper delves into geopolitical factors shaping both initiatives, the tension between a unilateral and a rules-based system of Asia-Europe connectivity and explores opportunities of enhanced connectivity cooperation between China and the EU. Findings – This paper identifies both key differences as well as synergies between the BRI and the EU Connectivity Strategy. The EU Connectivity Strategy for Asia and China’s Belt and Road Initiative (BRI) share similar goals in boosting sustainable growth and trade across the continents through investments in critical infrastructure. A sense of competition between the BRI and the Connectivity Strategy has the potential to change both initiatives for the better, however stronger commitment from the part of the EU will be necessary if it wants to be able to provide an alternative to China’s development model in third countries and sustain its privileged position as the world’s largest trading block. Research Implications – This article wants to foster pragmatic and goal-oriented dialogue between the EU and China that can lead to shared principles of connectivity. The key question is to what extent will the EU be able to respond to geopolitical realities and craft a rules-based alternative to China’s state-led economic development plan.

Triple-Network Dysconnectivity in Patients With First-Episode Psychosis and Individuals at Clinical High Risk for Psychosis

Ahra Kim,Minji Ha,Taekwan Kim,Sunghyun Park,Silvia Kyungjin Lho,Sun-Young Moon,김민아,Jun Soo Kwon 대한신경정신의학회 2022 PSYCHIATRY INVESTIGATION Vol.19 No.12

Objective In the triple-network model, the salience network (SN) plays a crucial role in switching between the default-mode network (DMN) and the central executive network (CEN). Aberrant patterns of triple-network connectivity have been reported in schizophrenia patients, while findings have been less consistent for patients in the early stages of psychotic disorders. Thus, the present study examined the connectivity among the SN, DMN, and CEN in first-episode psychosis (FEP) patients and individuals at clinical high risk (CHR) for psychosis. Methods Thirty-nine patients with FEP, 78 patients with CHR for psychosis, and 110 healthy controls (HCs) underwent resting-state functional magnetic resonance imaging. We compared the SN, DMN, and CEN connectivity patterns of the three groups. The role of the SN in networks with significant connectivity differences was examined by mediation analysis. Results FEP patients showed lower SN-DMN and SN-CEN (cluster-level F=5.83, false discovery rate [FDR] corrected-p=0.001) connectivity than HCs. There was lower SN-DMN connectivity (cluster-level F=3.06, FDR corrected-p=0.053) at a trend level in CHR subjects compared to HCs. Between HCs and FEP patients, mediation analysis showed that SN-DMN connectivity was a mediator between group and SN-CEN connectivity. Additionally, SN-CEN connectivity functioned as a mediator between group and SN-DMN connectivity. Conclusion Aberrant connectivity between the SN and DMN/CEN suggests disrupted network switching in FEP patients, although CHR subjects showed trend-level SN-DMN dysconnectivity. Our findings suggest that dysfunctional triple-network dynamics centered on the SN can appear in patients in the early stages of psychotic disorders.