• Title, Summary, Keyword: consensus model

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A Consensus Technique for Tropical Cyclone Intensity Prediction over the Western North Pacific (북서태평양 태풍 강도 예측 컨센서스 기법)

  • Oh, Youjung;Moon, Il-Ju;Lee, Woojeong
    • Atmosphere
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    • v.28 no.3
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    • pp.291-303
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    • 2018
  • In this study, a new consensus technique for predicting tropical cyclone (TC) intensity in the western North Pacific was developed. The most important feature of the present consensus model is to select and combine the guidance numerical models with the best performance in the previous years based on various evaluation criteria and averaging methods. Specifically, the performance of the guidance models was evaluated using both the mean absolute error and the correlation coefficient for each forecast lead time, and the number of the numerical models used for the consensus model was not fixed. In averaging multiple models, both simple and weighted methods are used. These approaches are important because that the performance of the available guidance models differs according to forecast lead time and is changing every year. In particular, this study develops both a multi-consensus model (M-CON), which constructs the best consensus models with the lowest error for each forecast lead time, and a single best consensus model (S-CON) having the lowest 72-hour cumulative mean error, through on training process. The evaluation results of the selected consensus models for the training and forecast periods reveal that the M-CON and S-CON outperform the individual best-performance guidance models. In particular, the M-CON showed the best overall performance, having advantages in the early stages of prediction. This study finally suggests that forecaster needs to use the latest evaluation results of the guidance models every year rather than rely on the well-known accuracy of models for a long time to reduce prediction error.

Discrete-Time State Feedback Algorithm for State Consensus of Uncertain Homogeneous Multi-Agent Systems (불확실성을 포함한 다 개체 시스템의 상태 일치를 위한 이산 시간 출력 궤환 협조 제어 알고리즘)

  • Yoon, Moon-Chae;Kim, Jung-Su;Back, Juhoon
    • Journal of Institute of Control, Robotics and Systems
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    • v.19 no.5
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    • pp.390-397
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    • 2013
  • This paper presents a consensus algorithm for uMAS (uncertain Multi-Agent Systems). Unlike previous results in which only nominal models for agents are considered, it is assumed that the uncertain agent model belongs to a known polytope set. In the middle of deriving the proposed algorithm, a convex set is found which includes all uncertainties in the problem using convexity of the polytope set. This set plays an important role in designing the consensus algorithm for uMAS. Based on the set, a consensus condition for uMAS is proposed and the corresponding consensus design problem is solved using LMI (Linear Matrix Inequality). Simulation result shows that the proposed consensus algorithm successfully leads to consensus of the state of uMAS.

MMOG User Participation Based Decentralized Consensus Scheme and Proof of Participation Analysis on the Bryllite Blockchain System

  • Yun, Jusik;Goh, Yunyeong;Chung, Jong-Moon;Kim, OkSeok;Shin, SangWoo;Choi, Jin;Kim, Yoora
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.13 no.8
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    • pp.4093-4107
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    • 2019
  • Proof of Work (PoW) based blockchains have limitations in throughput, time consumption, and energy efficiency. In these systems, a miner will consume significant time and resources to obtain a reward for contributing to the blockchain. To overcome these limitations, recent research on blockchains are focused on accelerating the speed, scalability, and enhancing the security level. By enhancing specific procedures of blockchain system, the level of data integrity supported by the blockchain can become more robust, and efficient. In this paper, a new blockchain consensus model based on the Bryllite Consensus Protocol (BCP) is proposed to support a hyper-connected massively multiplayer online game (MMOG) ecosystem. The BCP scheme enables users to participate directly in new consensus processes through a Proof of Participation (PoP) algorithm. In this model, the consensus algorithm has a simpler form while maintaining high security level. In addition, because the BCP scheme gives users an equal chance to make a contribution to the blockchain, rewards are distributed in an equal fashion, which motivates user participation. The analysis of the proposed scheme is applied to the Bryllite consortium blockchain system (homed in Hong Kong), which is a new blockchain network developed for international game industries, gamers, and game events.

Effects of Interaction Range on the Behavior of Opinion Consensus

  • Lee, Seungjae;Cho, Young Sul;Hong, Hyunsuk
    • Journal of the Korean Physical Society
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    • v.73 no.10
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    • pp.1406-1409
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    • 2018
  • We have frequently encountered the rapid changes that prevalent opinion of the social community is toppled by a new and opposite opinion against the pre-exiting one. To understand this interesting process, mean-field model with infinite-interaction range has been mostly considered in previous studies S. A. Marvel et al., Phys. Rev. Lett. 110, 118702 (2012). However, the mean-field interaction range is lack of reality in the sense that any individual cannot interact with all of the others in the community. Based on it, in the present work, we consider a simple model of opinion consensus so-called basic model on the low-dimensional lattices (d = 1, 2) with finite interaction range. The model consists of four types of subpopulations with different opinions: A, B, AB, and the zealot of A denoted by $A_c$, following the basic model shown in the work by S. A. Marvel et al.. Comparing with their work, we consider the finite range of the interaction, and particularly reconstruct the lattice structure by adding new links when the two individuals have the distance < ${\sigma}$. We explore how the interaction range ${\sigma}$ affects the opinion consensus process on the reconstructed lattice structure. We find that the critical fraction of population for $A_c$ required for the opinion consensus on A shows different behaviors in the small and large interaction ranges. Especially, the critical fraction for $A_c$ increases with the size of ${\sigma}$ in the region of small interaction range, which is counter-intuitive: When the interaction range is increased, not only the number of nodes affected by $A_c$ but also that affected by B grows, which is believed to cause the increasing behavior of the critical fraction for $A_c$. We also present the difference of dynamic process to the opinion consensus between the regions of small and large interaction ranges.

Output Consensus of Non-identical and Stabilizable Linear Systems Having the Same Transfer Matrix (동일한 전달 행렬을 가지는 안정화 가능한 이종 시스템들의 출력 일치)

  • Kim, Ji-Su;Kim, Hong-Keun;Shim, Hyung-Bo;Back, Ju-Hoon
    • Journal of Institute of Control, Robotics and Systems
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    • v.17 no.9
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    • pp.857-862
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    • 2011
  • This paper studies the output consensus problem for a class of heterogeneous linear multi-agent systems under a fixed directed communication network. The dynamics, as well as its dimension, of each agent can widely differ from the others, but all the agents are assumed to have the same transfer matrix. In addition, only the system outputs are constrained to be delivered through the network. Under these conditions, we show that the output consensus is reached by a group of identical controllers, which is designed to achieve the state consensus for the homogeneous multi-agent system obtained from the minimal realization of the transfer matrix. Finally, an example is given to demonstrate the proposed result.

A Study on Curriculum Development for Fundamentals of Nursing at the Graduate Level (대학원 기본간호학 전공 교육과정 개발을 위한 연구)

  • Chang Sung-Ok
    • Journal of Korean Academy of Fundamentals of Nursing
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    • v.12 no.2
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    • pp.162-170
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    • 2005
  • Purpose: This study was conducted to develop a curriculum model for fundamentals of nursing at the graduate level which reflects a consensus of educators and the students in Korean nursing society. Method: A survey was used with three groups to identify consensus on a curriculum model for fundamentals of nursing at the graduate level; 42 educators in fundamentals of nursing, 11 nurse educators whose major was not fundamentals of nursing and 70 nurses with a bachelor degree in nursing. Results: Consensus on a curriculum model at the graduate level were delineated from analysis of the survey, Based on these results, a curriculum model fur fundamentals of nursing at the graduate level is outlined: As one major area of nursing, fundamentals of nursing focuses on nursing practice based on basic human needs. Thus main focus of the curriculum for fundamentals of nursing at the graduate level is research performance and theory development on nursing interventions to meet basic human needs in clinical settings. Conclusions: A curriculum model for fundamentals of nursing at the graduate level suggests that its application may have a positive impact on development of distinct knowledge body for fundamentals of nursing that will differentiate the content of education for undergraduate and graduate levels of nursing. However, the suggestion for the curriculum model needs to be refined and developed for application.

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Quorum Consensus Method based on Ghost using Simplified Metadata (단순화된 메타데이타를 이용한 고스트 기반 정족수 동의 기법의 개선)

  • Cho, Song-Yean;Kim, Tai-Yun
    • Journal of KIISE:Computer Systems and Theory
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    • v.27 no.1
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    • pp.34-43
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    • 2000
  • Replicated data that is used for fault tolerant distributed system requires replica control protocol to maintain data consistency. The one of replica control protocols is quorum consensus method which accesses replicated data by getting majority approval. If site failure or communication link failure occurs and any one can't get quorum consensus, it degrades the availability of data managed by quorum consensus protocol. So it needs for ghost to replace the failed site. Because ghost is not full replica but process which has state information using meta data, it is important to simplify meta data. In order to maintain availability and simplify meta data, we propose a method to use cohort set as ghost's meta data. The proposed method makes it possible to organize meta data in 2N+logN bits and to have higher availability than quorum consensus only with cohort set and dynamic linear voting protocol. Using Markov model we calculate proposed method's availability to analyze availability and compare it with existing protocols.

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Social Consensus among Two sides of Industry and the Government and its Implication for Disability Policy (노.사.정 사회적 합의가 장애인 복지정책에 주는 함의)

  • Lee, Seong-Gyu
    • Korean Journal of Social Welfare
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    • v.36
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    • pp.259-283
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    • 1998
  • This research is based on the assumption that Korea's social consensus among two sides of industry and government on Feb. 2 '98 was not just temporary response to the economic crisis caused by International Monetary Fund financial fund. Some arguments on the applicability of social democracy and corporatism and D. Donnison's perspective on Democratic Socialism are employed in search of an appropriate social consensus model for Korean situation. In the process of analyzing Korean situation in historical context it becomes apparent that there is embryo of stable social consensus beyond the level of tentative social cooperation to overcome the economic crisis. The next step applying the social consensus model to the employment policy for people with disability levels up empirical and theoretical validity of this research. It casts some implications for disability labour market which demands another kind of social consensus among people with disability, employers and the government. These implications include a desirable solution for hard lives of unemployed people with disability in economic difficulties and current policy issues facing Korean government.

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Development of the Selected Multi-model Consensus Technique for the Tropical Cyclone Track Forecast in the Western North Pacific (태풍 진로예측을 위한 다중모델 선택 컨센서스 기법 개발)

  • Jun, Sanghee;Lee, Woojeong;Kang, KiRyong;Yun, Won-Tae
    • Atmosphere
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    • v.25 no.2
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    • pp.375-387
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    • 2015
  • A Selected Multi-model CONsensus (SMCON) technique was developed and verified for the tropical cyclone track forecast in the western North Pacific. The SMCON forecasts were produced by averaging numerical model forecasts showing low 70% latest 6 h prediction errors among 21 models. In the homogeneous comparison for 54 tropical cyclones in 2013 and 2014, the SMCON improvement rate was higher than the other forecasts such as the Non-Selected Multi-model CONsensus (NSMCON) and other numerical models (i.e., GDAPS, GEPS, GFS, HWRF, ECMWF, ECMWF_H, ECMWF_EPS, JGSM, TEPS). However, the SMCON showed lower or similar improvement rate than a few forecasts including ECMWF_EPS forecasts at 96 h in 2013 and at 72 h in 2014 and the TEPS forecast at 120 h in 2013. Mean track errors of the SMCON for two year were smaller than the NSMCON and these differences were 0.4, 1.2, 5.9, 12.9, 8.2 km at 24-, 48-, 72-, 96-, 120-h respectively. The SMCON error distributions showed smaller central tendency than the NSMCON's except 72-, 96-h forecasts in 2013. Similarly, the density for smaller track errors of the SMCON was higher than the NSMCON's except at 72-, 96-h forecast in 2013 in the kernel density estimation analysis. In addition, the NSMCON has lager range of errors above the third quantile and larger standard deviation than the SMCON's at 72-, 96-h forecasts in 2013. Also, the SMCON showed smaller bias than ECMWF_H for the cross track bias. Thus, we concluded that the SMCON could provide more reliable information on the tropical cyclone track forecast by reflecting the real-time performance of the numerical models.

Harmony through Holistic Engagement: An Emic Model of Greater East Asian Regionalism

  • von Feigenblatt, Otto F.
    • Journal of Contemporary Eastern Asia
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    • v.12 no.2
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    • pp.61-87
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    • 2013
  • This study applies grounded theory to develop an emic substantive theory of regional integration in Greater East Asia. The role of norms and policies is explored through discursive content analysis of a wide theoretical sample of official elite policy statements dealing with regionalism and related policy areas. A resulting model of regional integration titled "Harmony through Holistic Engagement" is then discussed in relation to the etic consensus on the phenomenon. The study concludes that the etic consensus on the nature of regional integration in Greater East Asia greatly differs from the results of an emic approach and thus reflects a normative consensus rather than a descriptive reality.