• Title/Summary/Keyword: Complex network theory

Search Result 99, Processing Time 0.03 seconds

Efficient Decision Making Support System by Rough-Neural Network and $\chi$2 (러프-신경망과 $\chi$2 검정에 의한 효율적인 의사결정지원 시스템)

  • Jeong, Hwan-Muk;Pi, Su-Yeong;Choe, Gyeong-Ok
    • The Transactions of the Korea Information Processing Society
    • /
    • v.6 no.8
    • /
    • pp.2106-2112
    • /
    • 1999
  • In decision-making, information is the thing manufactured as the useful type for decision -making. We can improve the efficiency of decision-making by elimination of unnecessary information. Rough set is the theory that can classify and reduce the unnecessary. But the reduction process of rough set becomes more complex according to the number of attribute and tuple. After eliminating of the dispensable attributes using $\chi$2 and rough set, the indispensable attributes are used for the units of input layers in neural network. This rough-neural network can support more correct decision-making of neural network.

  • PDF

Applying Connectivity Analysis for Prioritizing Unexecuted Urban Parks in Sungnam (연결성 분석을 통한 성남시 미집행 공원의 조성 우선순위 선정)

  • Ahn, Yoonjung;Lee, Dong-Kun;Kim, Hogul;Mo, Yongwon
    • Journal of the Korean Society of Environmental Restoration Technology
    • /
    • v.17 no.3
    • /
    • pp.75-86
    • /
    • 2014
  • An urban ecosystem is a complex system that includes social, economic and ecosystems. Therefore, it is important to consider its environmental capacity while developing a city plan. Most of the plans, however, consider only the social aspects, which fragments the green spaces and disturbs the movement of species. Sungnam has approximately 100 parks with unexecuted development plans and with great potential to contribute towards urban ecosystem enhancement. Therefore, this study applied network analysis to prioritize the development of city parks and contribute towards improving the green network, with Parus spp. as the target species. To compensate for the drawbacks of binary and possibility-based network analysis, this study included two indices, namely $BC^{PC}_K$, $BC^{IIC}_K$, $dPCconnector_k$ and $dIICconnector_k$. These indices make it possible to find patches that could play an important role in green network enhancement. The urban park with greater value gets a higher priority to be transformed into a park. Thus, our methodology could prove to be very useful in prioritizing the undeveloped parks, thereby supporting decision-making.

Computational electroencephalography analysis for characterizing brain networks

  • Sunwoo, Jun-Sang;Cha, Kwang Su;Jung, Ki-Young
    • Annals of Clinical Neurophysiology
    • /
    • v.22 no.2
    • /
    • pp.82-91
    • /
    • 2020
  • Electroencephalography (EEG) produces time-series data of neural oscillations in the brain, and is one of the most commonly used methods for investigating both normal brain functions and brain disorders. Quantitative EEG analysis enables identification of frequencies and brain activity that are activated or impaired. With studies on the structural and functional networks of the brain, the concept of the brain as a complex network has been fundamental to understand normal brain functions and the pathophysiology of various neurological disorders. Functional connectivity is a measure of neural synchrony in the brain network that refers to the statistical interdependency between neural oscillations over time. In this review, we first discuss the basic methods of EEG analysis, including preprocessing, spectral analysis, and functional-connectivity and graph-theory measures. We then review previous EEG studies of brain network characterization in several neurological disorders, including epilepsy, Alzheimer's disease, dementia with Lewy bodies, and idiopathic rapid eye movement sleep behavior disorder. Identifying the EEG-based network characteristics might improve the understanding of disease processes and aid the development of novel therapeutic approaches for various neurological disorders.

A Study on I-PID-Based 2-DOF Snake Robot Head Control Scheme Using RBF Neural Network and Robust Term (RBF 신경망과 강인 항을 적용한 I-PID 기반 2 자유도 뱀 로봇 머리 제어에 관한 연구)

  • Sung-Jae Kim;Jin-Ho Suh
    • The Journal of Korea Robotics Society
    • /
    • v.19 no.2
    • /
    • pp.139-148
    • /
    • 2024
  • In this paper, we propose a two-degree-of-freedom snake robot head system and an I-PID (Intelligent Proportional-Integral-Derivative)-based controller utilizing RBF (Radial Basis Function) neural network and adaptive robust terms as a control strategy to reduce rotation occurring in the snake robot head. This study proposes a two-degree-of-freedom snake robot head system to avoid complex snake robot dynamics. This system has a control system independent of the snake robot. Subsequently, it utilizes an I-PID controller to implement a control system that can effectively manage rotation at the snake robot head, the robot's nonlinearity, and disturbances. To compensate for the time delay estimation errors occurring in the I-PID control system, an RBF neural network is integrated. Additionally, an adaptive robust term is designed and integrated into the control system to enhance robustness and generate control inputs responsive to signal changes. The proposed controller satisfies stability according to Lyapunov's theory. The proposed control strategy was tested using a 9-degreeof-freedom snake robot. It demonstrates the capability to reduce rotation in Lateral undulation, Rectilinear, and Sidewinding locomotion.

A Study on the Interactions between the Actors of the 3D Broadcasting Standardization Process (3DTV방송기술 표준화과정의 참여자간 상호작용 : 행위자 네트워크 이론기반 사례연구)

  • Song, Kyung Hee;Kwak, Kyu Tae;Park, Soo Kyung;Lee, Bong Gyou
    • Journal of Internet Computing and Services
    • /
    • v.15 no.2
    • /
    • pp.109-127
    • /
    • 2014
  • This study is devised out of the recognition that the existing standardization-related research has not sufficiently examined the overall social environment where a standard is actually made and diffused and the roles of the actors and the changes in them in the complex social system where multiple stakeholders exist. Against this backdrop, this study purports to reconstruct the dynamic process of developing and standardizing an innovative technology through a socio-technical approach involved by multiple stakeholders with different interests in the context of a socio-technical institutional environment. The specific goals to achieve the purpose include first, inspecting the characteristics of the interactions between the human actors and between the human and non-human actors in the socio-technical network surrounding a standardization process. Second, the study aimed to observe the activities of the focal actor who led the standardization process and its changing role. To that end, it analyzed the dynamic features of the process of standardizing a HD 3DTV broadcasting technology that took place in South Korea based on the actor network theory. As for the analysis method, the researchers personally took part in the actor network involving the new technology to analyze the dynamic characteristics of the network, applying the qualitative research method of survey and in-depth interviews and exploring the overall dynamics of environment, behavior and technology observed over the course of the entire standardization process.

LoRa Network based Parking Dispatching System : Queuing Theory and Q-learning Approach (LoRa 망 기반의 주차 지명 시스템 : 큐잉 이론과 큐러닝 접근)

  • Cho, Youngho;Seo, Yeong Geon;Jeong, Dae-Yul
    • Journal of Digital Contents Society
    • /
    • v.18 no.7
    • /
    • pp.1443-1450
    • /
    • 2017
  • The purpose of this study is to develop an intelligent parking dispatching system based on LoRa network technology. During the local festival, many tourists come into the festival site simultaneously after sunset. To handle the traffic jam and parking dispatching, many traffic management staffs are engaged in the main road to guide the cars to available parking lots. Nevertheless, the traffic problems are more serious at the peak time of festival. Such parking dispatching problems are complex and real-time traffic information dependent. We used Queuing theory to predict inbound traffics and to measure parking service performance. Q-learning algorithm is used to find fastest routes and dispatch the vehicles efficiently to the available parking lots.

Analysis of Social Network According to The Distance of Characters Statements (소설 등장인물의 텍스트 거리를 이용한 사회 구성망 분석)

  • Park, Gyeong-Mi;Kim, Sung-Hwan;Cho, Hwan-Gue
    • The Journal of the Korea Contents Association
    • /
    • v.13 no.4
    • /
    • pp.427-439
    • /
    • 2013
  • With the fast development of complex science, lots of social networks are studied. We know that the social network is widely applied in analyzing issues in human culture, economics and web sciences. Recently we witness that some researchers began to compare the social network constructed from fiction literatures(literature social network) and the real social network obtained from practice. But we point that previous approaches for literature social network have some drawbacks since they completely depend on the biographical dictionary constructed for a designated literature. So since the previous approach focus on the few important characters and peoples around them, we can not understand the global structure of all characters appeared in the literature at least once. We propose one method to extract all characters appeared in the literature and how to make the social network from that information. Also we newly propose K-critical network by applying frequency of the named characters and the strength of relationship among all textual characters. Our experiment shows that the K-critical measure could be one crucial quantitative measure to compute the relationship strength among characters appeared in the object literature.

A Studying on Gap Sensing using Fuzzy Filter and ART2 (퍼지필터와 ART2를 이용한 선박용 용접기술개발)

  • 김관형;이재현;이상배
    • Journal of Korean Port Research
    • /
    • v.14 no.3
    • /
    • pp.321-329
    • /
    • 2000
  • Welding is essential for the manufacture of a range of engineering components which may vary from very large structures such as ships and bridges to very complex structures such as aircraft engines, or miniature components for microelectronic applications. Especially, a domestic situation of the welding automation is still depend on the arc sensing system in comparison to the vision sensing system. Specially, the gap-detecting of workpiece using conventional arc sensor is proposed in this study. As a same principle, a welding current varies with the size of a welding gap. This study introduce to the fuzzy membership filter to cancel a high frequency noise of welding current, and ART2 which has the competitive learning network classifies the signal patterns the filtered welding signal. A welding current possesses a specific pattern according to the existence or the size of a welding gap. These specific patterns result in different classification in comparison with an occasion for no welding gap. The patterns in each case of 1mm, 2mm, 3mm and no welding gap are identified by the artificial neural network.

  • PDF

A Two-dimensional Supramolecular Network Built through Unique π-πStacking: Synthesis and Characterization of [Cu(phen)2(μ-ID A)Cu(phen)·(NO3)](NO3)·4(H2O)

  • Lin, Jian-Guo;Qiu, Ling Qiu;Xu, Yan-Yan
    • Bulletin of the Korean Chemical Society
    • /
    • v.30 no.5
    • /
    • pp.1021-1025
    • /
    • 2009
  • A novel supramolecular network containing binuclear copper unit $[Cu(phen)_{2}({\mu}-ID\;A)Cu(phen){\cdot}(NO_{3})](NO_{3}){\cdot}4(H_{2}O)$ (1) was synthesized through the self-assembly of iminodiacetic acid ($H_2IDA$) and 1,10-phenanthroline (phen) in the condition of pH = 6. It has been characterized by the infrared (IR) spectroscopy, elemental analysis, single crystal X-ray diffraction, and thermogravimetric analysis (TGA). 1 shows a 2-D supramolecular structure assembled through strong and unique $\pi-\pi$ packing interactions. Density functional theory (DFT) calculations show that theoretical optimized structures can well reproduce the experimental structure. The TGA and powder X-ray diffraction (PXRD) curves indicate that the complex 1 can maintain the structural integrity even at the loss of free water molecules. The magnetic property is also reported in this paper.

Analysis of a Large-scale Protein Structural Interactome: Ageing Protein structures and the most important protein domain

  • Bolser, Dan;Dafas, Panos;Harrington, Richard;Schroeder, Michael;Park, Jong
    • Proceedings of the Korean Society for Bioinformatics Conference
    • /
    • 2003.10a
    • /
    • pp.26-51
    • /
    • 2003
  • Large scale protein interaction maps provide a new, global perspective with which to analyse protein function. PSIMAP, the Protein Structural Interactome Map, is a database of all the structurally observed interactions between superfamilies of protein domains with known three-dimensional structure in thePDB. PSIMAP incorporates both functional and evolutionary information into a single network. It makes it possible to age protein domains in terms of taxonomic diversity, interaction and function. One consequence of it is to predict the most important protein domain structure in evolution. We present a global analysis of PSIMAP using several distinct network measures relating to centrality, interactivity, fault-tolerance, and taxonomic diversity. We found the following results: ${\bullet}$ Centrality: we show that the center and barycenter of PSIMAP do not coincide, and that the superfamilies forming the barycenter relate to very general functions, while those constituting the center relate to enzymatic activity. ${\bullet}$ Interactivity: we identify the P-loop and immunoglobulin superfamilies as the most highly interactive. We successfully use connectivity and cluster index, which characterise the connectivity of a superfamily's neighbourhood, to discover superfamilies of complex I and II. This is particularly significant as the structure of complex I is not yet solved. ${\bullet}$ Taxonomic diversity: we found that highly interactive superfamilies are in general taxonomically very diverse and are thus amongst the oldest. This led to the prediction of the oldest and most important protein domain in evolution of lift. ${\bullet}$ Fault-tolerance: we found that the network is very robust as for the majority of superfamilies removal from the network will not break up the network. Overall, we can single out the P-loop containing nucleotide triphosphate hydrolases superfamily as it is the most highly connected and has the highest taxonomic diversity. In addition, this superfamily has the highest interaction rank, is the barycenter of the network (it has the shortest average path to every other superfamily in the network), and is an articulation vertex, whose removal will disconnect the network. More generally, we conclude that the graph-theoretic and taxonomic analysis of PSIMAP is an important step towards the understanding of protein function and could be an important tool for tracing the evolution of life at the molecular level.

  • PDF