• KSII Transactions on Internet and Information Systems (TIIS)
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• 제14권4호
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• pp.1624-1647
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• 2020

Vehicular network is one of the most important subjects for researchers in recent years. Anycast routing protocols have many applications in vehicular ad hoc networks. The aim of an anycast protocol is sending packets to at least one of the receivers among candidate receivers. Studies done on anycast protocols over vehicular networks, however, have capability of implementation on some applications; they are partial, and application specific. No need to say that the lack of a comprehensive study, having a strong analytical background, is felt. Mathematical modeling in vehicular networks is difficult because the topology of these networks is dynamic. In this paper, it has been demonstrated that vehicular networks can be modeled based on time-expanded networks. The focus of this article is on geographical anycast. Three different scenarios were proposed including sending geographic anycast packet to exactly-one-destination, to at-least-one-destination, and to K-anycast destination, which can cover important applications of geographical anycast routing protocols. As the proposed model is of MILP type, a decentralized heuristic algorithm was presented. The evaluation process of this study includes the production of numerical results by Branch and Bound algorithm in general algebraic modeling system (GAMS) software and simulation of the proposed protocol in OMNET++ simulator. The comprehension of the result of proposed protocol and model shows that the applicability of this proposed protocol and its reactive conformity with the presented models based on presented metrics.

• 정보처리학회논문지:컴퓨터 및 통신 시스템
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• 제2권5호
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• pp.209-216
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• 2013

전통적인 사회관계망 분석에 있어서 각 노드의 매개 중심도는 메시지 전달 측면에서의 각 노드들의 상대적인 중요도를 파악하는 척도로 오랫동안 사용되어 왔다. 하지만, 매개 중심도를 산출하기 위한 계산 복잡도가 높기 때문에 노드의 수와 간선의 수가 매우 많은 대규모 사회관계망에서는 각 노드의 매개 중심도를 산출하기가 어렵다. 본 논문에서는 각 노드들마다 자신의 지역정보, 즉 이웃노드들이 지닌 각각의 이웃노드 정보를 활용하여 구성가능한 확장 자아 네트워크(Expanded Ego Network)를 새롭게 정의하고 이러한 네트워크를 기반으로 확장 자아 매개 중심도(Expanded Ego Betweenness Centrality)를 정의한다. 일반적인 사회관계망의 특성인 척도 없는 네트워크(Scale-free Network)를 생성할 수 있는 Barab$\acute{a}$si-Albert 네트워크 모델을 사용한 실험을 통하여 제안한 확장 자아 매개 중심도의 각 노드별 순위는 기존의 전통적인 방식으로 산출한 매개 중심도의 각 노드별 순위와 거의 일치함을 보인다.

• 한국IT서비스학회지
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• 제19권1호
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• pp.1-16
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• 2020

Suncheon City Regeneration Project is known as the concept of cultural residents. Through the previous projects, the residents' capabilities have been improved, and the projects have been carried out according to their strategies. For this reason, participants in urban regeneration projects are important. The purpose of this study is to actually identify the 'rescue center' and 'direct relationship' with the analysis utilizing the characteristics of social networks NetMiner solution of the participants, who led the project, Suncheon. Surveys and interviews were conducted for participants, and the characteristics of social networks were analyzed in time series to quantify and visualize the results. As a result of the analysis, social networks were changed among the participants before and after the urban regeneration project. Initially, loose networks were denser over time, and initially networks formed only around participants were expanded over time. Network analysis has revealed that the system is strengthening with urban regeneration projects in the form of public and public-private cooperation. This highlights the need for a city-centered urban regeneration strategy centered on people and shows that a dense network of participants can be a success factor.

• 한국수소및신에너지학회논문집
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• 제33권4호
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• pp.318-329
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• 2022

This study analyzed keyword networks and Author's Affiliation networks of hydrogen-related papers published in Korea Citation Index (KCI) journals from 2016 to 2020. The study investigated co-occurrence patterns of institutions over time to examine collaboration trends of hydrogen scholars. The study also conducted frequency analysis of keyword networks to identify key topics and visualized keyword networks to explore topic trends. The result showed Collaborative research between institutions has not yet been extensively expanded. However, collaboration trends were much more pronounced with local universities. Keyword network analysis exhibited continuing diversification of topics in hydrogen research of Korea. In addition centrality analysis found hydrogen research mostly deals with multi-disciplinary and complex aspects like hydrogen production, transportation, and public policy.

• 제어로봇시스템학회논문지
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• 제6권12호
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• pp.1113-1119
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• 2000

To operate a process plant safely and economically, process monitoring is very important. Process monitoring is the task to identify the state of the system from sensor data. Process monitoring includes data acquisition, regulatory control, data reconciliation, fault detection, etc. This research focuses on the data recon-ciliation using scale-space filtering and fault detection using functional-link associative neural networks. Scale-space filtering is a multi-resolution signal analysis method. Scale-space filtering can extract highest frequency factors(noise) effectively. But scale-space filtering has too large calculation costs and end effect problems. This research reduces the calculation cost of scale-space filtering by applying the minimum limit to the gaussian kernel. And the end-effect that occurs at the end of the signal of the scale-space filtering is overcome by using extrapolation related with the clustering change detection method. Nonlinear principal component analysis methods using neural network have been reviewed and the separately expanded functional-link associative neural network is proposed for chemical process monitoring. The separately expanded functional-link associative neural network has better learning capabilities, generalization abilities and short learning time than the exiting-neural networks. Separately expanded functional-link associative neural network can express a statistical model similar to real process by expanding the input data separately. Combining the proposed methods-modified scale-space filtering and fault detection method using the separately expanded functional-link associative neural network-a process monitoring system is proposed in this research. the usefulness of the proposed method is proven by its application a boiler water supply unit.

• International Journal of Advanced Culture Technology
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• 제8권3호
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• pp.325-333
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• 2020

In the past, eating outside was usually the purpose of eating. However, it has recently expanded into a restaurant culture market. In particular, a dessert culture is being established where people can talk and enjoy. Each consumer has a different tendency to buy chocolate such as health, taste, and atmosphere. Therefore, it is time to recommend chocolate according to consumers' tendency to eat out. In this paper, we propose a chocolate recommendation application based on the tendency to eat out using data on social networks. To collect keyword-based chocolate information, Textom is used as a text mining big data analysis solution.Text mining analysis and related topics are extracted and modeled. Because to shorten the time to recommend chocolate to users. In addition, research on the propensity of eating out is based on prior research. Finally, it implements hybrid app base.

• 대한기계학회논문집
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• 제16권7호
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• pp.1322-1331
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• 1992

본 연구에서는 Fig.3과 같은 다층 퍼셉트론을 사용하기로 한다. 그리고 위 에서 언급한 세가지점에서 다층퍼셉트론을 다시 살펴보아 해결하고자 하는 문제에 맞 도록 다층퍼셉트론을 개선시켜 보기로 한다. 따라서 본 연구의 목적은 제한조건을 갖는 문제를 풀기위한 새로운 형태의 다층퍼셉트론 설계 및 이에 적합한 학습규칙을 적용하여 보다 간단한 구조와 빠른 학습시간을 갖는 신경망을 구성하는데 있다.

• Earthquakes and Structures
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• 제26권2호
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• pp.87-96
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• 2024

This paper proposes a logistic multinomial regression approach to model the spatial cross-correlation of damage probabilities among different damage states in an expanded transportation network. Utilizing Bayesian theory and the multinomial logistic model, we analyze the damage states and probabilities of bridges while incorporating damage correlation. This correlation is considered both between bridges in a network and within each bridge's damage states. The correlation model of damage probabilities is applied to the seismic assessment of a portion of Tehran's transportation network, encompassing 26 bridges. Additionally, we introduce extra daily traffic time (EDTT) as an operational parameter of the transportation network and employ the shortest path algorithm to determine the path between two nodes. Our results demonstrate that incorporating the correlation of damage probabilities reduces the travel time of the selected network. The average decrease in travel time for the correlated case compared to the uncorrelated case, using two selected EDTT models, is 53% and 71%, respectively.

• 정보처리학회논문지:소프트웨어 및 데이터공학
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• 제4권1호
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• pp.37-44
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• 2015

사회관계망 분석에 있어서 매개 중심도(Betweenness Centrality)는 네트워크를 구성하는 노드들의 상대적인 중요도를 파악하기 위한 척도로서 주로 사용되어 왔다. 그러나 매개 중심도를 측정하기 위한 시간 복잡도가 높기 때문에 대규모의 온라인 사회관계망 서비스에서 각 노드의 매개 중심도를 산출하는 것은 쉽지 않은 문제이다. 그래서 본 연구팀에서는 과거에 네트워크를 구성하는 각각의 노드들마다 자신의 지역 정보를 활용하여 확장 자아 네트워크(Expanded Ego Network)를 정의하고 그 네트워크에서 확장 자아 매개 중심도(Expanded Ego Betweenness)를 산출하여 기존의 매개 중심도를 대체하려는 시도를 하였다. 본 논문에서는 지역정보 기반의 확장 자아 네트워크의 특징을 분석하여 확장 자아 매개 중심도를 빠르게 산출할 수 있는 알고리즘을 제안한다. 그리고 일반적인 사회관계망의 특성을 대표하는 Barab$\acute{a}$si-Albert 네트워크 모델을 사용한 가상 네트워크와 실제 사회관계망을 대표하는 페이스북 친구 관계 네트워크에서의 실험을 통하여 확장 자아 매개 중심도의 중요도 순위가 기존 매개 중심도의 중요도 순위와 거의 일치함을 보인다. 또한 제안하는 알고리즘이 기존 알고리즘에 비해 확장 자아 네트워크에서의 확장 자아 매개 중심도를 더 빠르게 산출함을 보인다.

• 대한전자공학회논문지TC
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• 제47권2호
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• pp.95-102
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• 2010

본 논문에서는 실시간 동작 환경인 VoIP에 적용 가능한 SPIT 대응 기법으로서 확장 화이트리스트 기법과 이를 적용한 SPIT 대응 프레임워크를 제안한다. SPIT을 차단하기 위한 연구가 다양하게 진행되고 있지만, SPIT 대응을 위한 기존 기법들은 스패머가 자신의 ID를 바꿔가면서 지속적으로 SPIT을 전송하는 공격에 취약하다. 또한 기존 SPIT 대응 프레임워크들은 프레임워크를 구성하고 있는 모든 SPIT 대응 기법들이 실시간으로 수행되어야 하기 때문에 콜 세션 설립 시간에 지연이 발생한다. 제안 기법은 화이트리스트를 이용한 사회망을 형성하여 화이트리스트의 범위를 확장하지만 전체 데이터베이스를 검색하지 않고 빠르게 그 통과 여부를 결정하는 방법이다. 제안하는 SPIT 대응 프레임워크는 3 단계 구성과 Fast Scoring 시스템을 이용하여 사용자의 직접적인 개입으로 인한 사용자의 불편성과 세션 설립 시간 지연을 최소화한다. 따라서 제안 기법 및 프레임워크는 실시간 동작을 요구하는 VoIP 환경에서 SPIT에 효과적으로 대응할 수 있다.