• Title/Summary/Keyword: Local and global approach

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The Fuzzy Modeling by Virus-messy Genetic Algorithm (바이러스-메시 유전 알고리즘에 의한 퍼지 모델링)

  • 최종일;이연우;주영훈;박진배
    • Proceedings of the Korean Institute of Intelligent Systems Conference
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    • 2000.11a
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    • pp.157-160
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    • 2000
  • This paper deals with the fuzzy modeling for the complex and uncertain system in which conventional and mathematical models may fail to give satisfactory results. mGA(messy Genetic Algorithm) has more effective and adaptive structure than sGA with respect to using changeable-length string and VEGA(Virus Evolution Genetic) Algorithm) can search the global and local optimal solution simultaneously with reverse transcription operator and transduction operator. Therefore in this paper, the optimal fuzzy model is obtained using Virus-messy Genetic Algorithm(Virus-mGA). In this method local information is exchanged in population so that population may sustain genetic divergence. To prove the surperioty of the proposed approach, we provide the numerical example.

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Design and Implementation of Rule-based Mask Layout Transformation System (규칙에 기초한 마스크 레이아웃 변환 시스템의 설계 및 구현)

  • 이재황;전주식
    • Journal of the Korean Institute of Telematics and Electronics A
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    • v.30A no.9
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    • pp.46-58
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    • 1993
  • Owing to the nature of locality in mask layouts, it appears that most mask layout problems can be solved by transforming a part of the given mask layout into a better layout segment continuously toward a global suboptimal solution. This notion of local transformation addresses major weak points of existing mask layout processing systems, which lack both extensibility and unifiability. This paper attempts to elaborate upon developing a new rule-based mask layout transformation system wherein most of the mask layout problems can be solved under the unified framework of local mask layout transformation. The rule-based mask layout transformation system is applicable to various mask layout problems such as net extraction, mask layout compaction, mask layout editing, and design rule checking. The experimental results show that the rule-based expert system approach is an efficient means of solving those mask layout problems, and thus confronting major drawbacks of existing layout processing systems.

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A Study on Damage Process Analysis for Steel Pier Subjected to Seismic Excitation (강한 지진 하중하에서 강재 교각의 손상 거동 연구)

  • Park, Yeon Soo;Park, Keun Koo;Park, Sun Joon
    • Journal of Korean Society of Steel Construction
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    • v.12 no.3 s.46
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    • pp.251-258
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    • 2000
  • Based on the numerical investigations using steel bridge pier subjected to strong seismic excitations a new approach to seismic damage assessment for steel structures and their members has been proposed in conjunction with the suggested definition of failure state. The relevant failure form of the steel pier is evaluated. It is revealed that when a seismic load has a short period, the failure of global buckling beyond the allowable displacement is more dominant than that by that of the local buckling caused by the accumulation of plastic strain. When a seismic load is not beyond this certain part, but repeats within the range of where a plastic deformation occurs, the plastic strain is accumulated on the partial element of bottom edge of steel pier and the failure occurs by the local buckling from the accumulated plastic local strain.

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Long-term and multidisciplinary research networks on biodiversity and terrestrial ecosystems: findings and insights from Takayama super-site, central Japan

  • Hiroyuki Muraoka;Taku M. Saitoh;Shohei Murayama
    • Journal of Ecology and Environment
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    • v.47 no.4
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    • pp.228-240
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    • 2023
  • Growing complexity in ecosystem structure and functions, under impacts of climate and land-use changes, requires interdisciplinary understandings of processes and the whole-system, and accurate estimates of the changing functions. In the last three decades, observation networks for biodiversity, ecosystems, and ecosystem functions under climate change, have been developed by interested scientists, research institutions and universities. In this paper we will review (1) the development and on-going activities of those observation networks, (2) some outcomes from forest carbon cycle studies at our super-site "Takayama site" in Japan, and (3) a few ideas how we connect in-situ and satellite observations as well as fill observation gaps in the Asia-Oceania region. There have been many intensive research and networking efforts to promote investigations for ecosystem change and functions (e.g., Long-Term Ecological Research Network), measurements of greenhouse gas, heat, and water fluxes (flux network), and biodiversity from genetic to ecosystem level (Biodiversity Observation Network). Combining those in-situ field research data with modeling analysis and satellite remote sensing allows the research communities to up-scale spatially from local to global, and temporally from the past to future. These observation networks oftern use different methodologies and target different scientific disciplines. However growing needs for comprehensive observations to understand the response of biodiversity and ecosystem functions to climate and societal changes at local, national, regional, and global scales are providing opportunities and expectations to network these networks. Among the challenges to produce and share integrated knowledge on climate, ecosystem functions and biodiversity, filling scale-gaps in space and time among the phenomena is crucial. To showcase such efforts, interdisciplinary research at 'Takayama super-site' was reviewed by focusing on studies on forest carbon cycle and phenology. A key approach to respond to multidisciplinary questions is to integrate in-situ field research, ecosystem modeling, and satellite remote sensing by developing cross-scale methodologies at long-term observation field sites called "super-sites". The research approach at 'Takayama site' in Japan showcases this response to the needs of multidisciplinary questions and further development of terrestrial ecosystem research to address environmental change issues from local to national, regional and global scales.

A Framework for Cognitive Agents

  • Petitt, Joshua D.;Braunl, Thomas
    • International Journal of Control, Automation, and Systems
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    • v.1 no.2
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    • pp.229-235
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    • 2003
  • We designed a family of completely autonomous mobile robots with local intelligence. Each robot has a number of on-board sensors, including vision, and does not rely on global positioning systems The on-board embedded controller is sufficient to analyze several low-resolution color images per second. This enables our robots to perform several complex tasks such as navigation, map generation, or providing intelligent group behavior. Not being limited to playing the game of soccer and being completely autonomous, we are also looking at a number of other interesting scenarios. The robots can communicate with each other, e.g. for exchanging positions, information about objects or just the local states they are currently in (e.g. sharing their current objectives with other robots in the group). We are particularly interested in the differences between a behavior-based approach versus a traditional control algorithm at this still very low level of action.

A Co-Evolutionary Computing for Statistical Learning Theory

  • Jun Sung-Hae
    • International Journal of Fuzzy Logic and Intelligent Systems
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    • v.5 no.4
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    • pp.281-285
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    • 2005
  • Learning and evolving are two basics for data mining. As compared with classical learning theory based on objective function with minimizing training errors, the recently evolutionary computing has had an efficient approach for constructing optimal model without the minimizing training errors. The global search of evolutionary computing in solution space can settle the local optima problems of learning models. In this research, combining co-evolving algorithm into statistical learning theory, we propose an co-evolutionary computing for statistical learning theory for overcoming local optima problems of statistical learning theory. We apply proposed model to classification and prediction problems of the learning. In the experimental results, we verify the improved performance of our model using the data sets from UCI machine learning repository and KDD Cup 2000.

Palmprint Verification Using Multi-scale Gradient Orientation Maps

  • Kim, Min-Ki
    • Journal of the Optical Society of Korea
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    • v.15 no.1
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    • pp.15-21
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    • 2011
  • This paper proposes a new approach to palmprint verification based on the gradient, in which a palm image is considered to be a three-dimensional terrain. Principal lines and wrinkles make deep and shallow valleys on a palm landscape. Then the steepest slope direction in each local area is first computed using the Kirsch operator, after which an orientation map is created that represents the dominant slope direction of each pixel. In this study, three orientation maps were made with different scales to represent local and global gradient information. Next, feature matching based on pixel-unit comparison was performed. The experimental results showed that the proposed method is superior to several state-of-the-art methods. In addition, the verification could be greatly improved by fusing orientation maps with different scales.

Two-dimensional rod theory for approximate analysis of building structures

  • Takabatake, Hideo
    • Earthquakes and Structures
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    • v.1 no.1
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    • pp.1-19
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    • 2010
  • It has been known that one-dimensional rod theory is very effective as a simplified analytical approach to large scale or complicated structures such as high-rise buildings, in preliminary design stages. It replaces an original structure by a one-dimensional rod which has an equivalent stiffness in terms of global properties. If the structure is composed of distinct constituents of different stiffness such as coupled walls with opening, structural behavior is significantly governed by the local variation of stiffness. This paper proposes an extended version of the rod theory which accounts for the two-dimensional local variation of structural stiffness; viz, variation in the transverse direction as well as longitudinal stiffness distribution. The governing equation for the two-dimensional rod theory is formulated from Hamilton's principle by making use of a displacement function which satisfies continuity conditions across the boundary between the distinct structural components in the transverse direction. Validity of the proposed theory is confirmed by comparison with numerical results of computational tools in the cases of static, free vibration and forced vibration problems for various structures.

A decentralized approach to damage localization through smart wireless sensors

  • Jeong, Min-Joong;Koh, Bong-Hwan
    • Smart Structures and Systems
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    • v.5 no.1
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    • pp.43-54
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    • 2009
  • This study introduces a novel approach for locating damage in a structure using wireless sensor system with local level computational capability to alleviate data traffic load on the centralized computation. Smart wireless sensor systems, capable of iterative damage-searching, mimic an optimization process in a decentralized way. The proposed algorithm tries to detect damage in a structure by monitoring abnormal increases in strain measurements from a group of wireless sensors. Initially, this clustering technique provides a reasonably effective sensor placement within a structure. Sensor clustering also assigns a certain number of master sensors in each cluster so that they can constantly monitor the structural health of a structure. By adopting a voting system, a group of wireless sensors iteratively forages for a damage location as they can be activated as needed. Since all of the damage searching process occurs within a small group of wireless sensors, no global control or data traffic to a central system is required. Numerical simulation demonstrates that the newly developed searching algorithm implemented on wireless sensors successfully localizes stiffness damage in a plate through the local level reconfigurable function of smart sensors.

The Multi-Scalar Practices of the Labour and Economic Geography of TNCs: A Study on the Labour Geography of Nestlé Korea (노동자들의 다중스케일적 실천과 초국적 기업의 경제지리: 한국네슬레노동조합의 노동지리를 사례로)

  • Hwang, Jin-Tae
    • Journal of the Economic Geographical Society of Korea
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    • v.24 no.1
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    • pp.52-75
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    • 2021
  • The current Korean labour movement is at an impasse that is partly sustained by the idea of "strong" transnational corporations (TNCs) versus "weak" labour, and this perception is based on the "global-local dichotomy," wherein TNCs are depicted as abstract and structured entities operating at the global scale and workers are represented as having a concrete and weak presence within the local sphere. As an alternative perspective to break this "global" capital vs. "local" labour dichotomy, I focus on labour geography, which assumes that labour is not simply a factor of production but a sentient spatial actor that (un-)intentionally produces the landscape of capitalism. Borrowing insights from the multi-scalar perspective, this paper aims to understand the actual methods in which workers utilize spatial strategies through an empirical case study of the Nestlé Korea labour union strike in 2003. Based on this case study, this paper claims that workers are both capable of employing coordinated multi-scalar practices and can be more influential to the economic geographies of TNCs. Additionally, it suggests that workers' scalar practices are actually more complicated and multi-directional as a result of their complex and dynamic interactions with political, economic and cultural forces and actors at diverse geographical scales.