• 제목/요약/키워드: complex system theory

검색결과 418건 처리시간 0.023초

A Study on Socio-technical System for Sustainability of the 4th Industrial Revolution: Machine Learning-based Analysis

  • Lee, Jee Young
    • International Journal of Internet, Broadcasting and Communication
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    • 제12권4호
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    • pp.204-211
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    • 2020
  • The era of the 4th industrial revolution is a complex environment in which the cyber world and the physical world are integrated and interacted. In order to successfully implement and be sustainable the 4th industrial revolution of hyper-connectivity, hyper-convergence, and hyper-intelligence, not only the technological aspects that implemented digitalization but also the social aspects must be recognized and dealt with as important. There are socio-technical systems and socio-technical systems theory as concepts that describe systems involving complex interactions between the environmental aspects of human, mechanical and tissue systems. This study confirmed how the Socio-technical System was applied in the research literature for the last 10 years through machine learning-based analysis. Eight clusters were derived by performing co-occurrence keywords network analysis, and 13 research topics were derived and analyzed by performing a structural topic model. This study provides consensus and insight on the social and technological perspectives necessary for the sustainability of the 4th industrial revolution.

Interval finite element method for complex eigenvalues of closed-loop systems with uncertain parameters

  • Zhang, XiaoMing;Ding, Han
    • Structural Engineering and Mechanics
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    • 제26권2호
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    • pp.163-178
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    • 2007
  • In practical engineering, the uncertain concept plays an important role in the control problems of the vibration structures. In this paper, based on matrix perturbation theory and interval finite element method, the closed-loop vibration control system with uncertain parameters is discussed. A new method is presented to develop an algorithm to estimate the upper and lower bounds of the real parts and imaginary parts of the complex eigenvalues of vibration control systems. The results are derived in terms of physical parameters. The present method is implemented for a vibration control system of the frame structure. To show the validity and effectiveness, we compare the numerical results obtained by the present method with those obtained by the classical random perturbation.

Dynamic characteristics of a CSTR with MMA polymerization

  • Ahn, Jong-Pil;Rhee, Hyun-Ku
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 1992년도 한국자동제어학술회의논문집(국제학술편); KOEX, Seoul; 19-21 Oct. 1992
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    • pp.100-105
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    • 1992
  • A mathematical model is developed for a CSTR in which free radical solution polymerization of methyl methacrylate(MMA) takes place. It turns out that five ordinary differential equations are to be treated simultaneously in order to predict the reactor performance. Although the reaction proceeds under the conditions of relatively low temperature and pressure, the system shows very complex bifurcation features due to the diffusion limitation (gel effect) and the temperature dependence of the kinetic parameters and physical properties. The effects of various system parameters on the reactor performance as well as on the polymer properties are investigated by using the bifurcation analysis. The application of the singularity theory enables us to divide the parameter space into several different regions, in each of which the system takes a unique steady state structure. Under certain circumstances, complex dynamic features such as HB points and limit cycles are observed and these should be taken into consideration in the reactor design.

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의과대학생을 위한 체제적 진로상담 모델과 전략 (A Systematic Career Advising Model and Strategies for Medical Students)

  • 이영희
    • 의학교육논단
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    • 제24권3호
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    • pp.193-204
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    • 2022
  • One of the important roles of medical schools is to support medical students in deciding upon their future career path or choosing their specialty. The purpose of this study is to suggest a career advising model and strategies for medical students through a systematic approach. This study consists of three parts. The first part introduces some main career theories: super's career development theory, career decision-making theory, social cognitive career theory, and ecosystem theory. The second part proposes a systematic career advising model using the results acquired from previous studies and theories. This model considers a medical school as a social system that consists of two domains (internal and external). This social system is considered as a complex where various factors interact with each other: students' individual characteristics, institutional policies and culture, curriculum and learning experience, students' perceived specialty characteristics, and aspects of the external environment such as healthcare systems. The third part suggests some career advising strategies based on a systematic approach that medical schools can apply. These research results can be used for designing career advising courses for medical students, integrating various career advising programs and resources of medical schools, and evaluating the outcomes of career advising programs at an institutional level.

복잡계 패러다임의 특성과 전망 (Nature and Prospect of Complexity Paradigm)

  • 김문조
    • 과학기술학연구
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    • 제3권2호
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    • pp.1-27
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    • 2003
  • 이 논문은 최근 자연과학 분야에서는 물론이요 사회과학과 더불어 인문예술 영역에 이르는 방대한 학문 영역에서 영향력을 행사하고 있는 복잡계 패러다임의 특성과 전망을 고찰하고자 한 것이다. 흔히 '전체론적 세계관'이라든가 '심층생태학적 관점' 등으로 대변되는 복잡성 패러다임은 개방체계적 사고의 연장선상에 위치한 것으로서, 일차적으로는 개방성, 성장성, 가형성, 否(부)의 엔트로피, 적극적 환류, 자기규제성, 자기목적성, 등종착성과 같은 개방체계적 속성을 함유한다. 그러나 지난 20여 년간 학제적 경계를 초월해 활발히 진전된 복잡계론은 종전의 개방체계론적 논의 수준을 넘어서는 새로운 착상이나 증거를 지속적으로 축적해 온 바, 여기서는 (1) 복잡계 이론이 형성되고 발전되어온 전개과정을 간략히 개관하고, (2) 비평형성, 비선형성, 소산구조 자기조직성, 프랙탈 기하학, 자동생산성 및 공진화와 같은 복잡계의 주요 특성들을 논의하며, (3) 니클라스 루만의 체계이론을 사례로 복잡계 패러다임의 사회과학적 적용을 검토한 후, (4) 복잡계 패러다임의 함의와 전망을 진단해 보고자 한다.

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Ductile fracture simulation using phase field approach under higher order regime

  • Nitin Khandelwal;Ramachandra A. Murthy
    • Structural Engineering and Mechanics
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    • 제89권2호
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    • pp.199-211
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    • 2024
  • The loading capacity of engineering structures/components reduces after the initiation and propagation of crack eventually leads to the final failure. Hence, it becomes essential to deal with the crack and its effects at the design and simulation stages itself, by detecting the prone area of the fracture. The phase-field (PF) method has been accepted widely in simulating fracture problems in complex geometries. However, most of the PF methods are formulated with second order continuity theoryinvolving C0 continuity. In the present study, PF method based on fourth-order (i.e., higher order) theory, maintaining C1 continuity has been proposed for ductile fracture simulation. The formulation includes fourth-order derivative terms of phase field variable, varying between 0 and 1. Applications of fourth-order PF theory to ductile fracture simulation resulted in novelty in this area. The proposed formulation is numerically solved using a two-dimensional finite element (FE) framework in 3-layered manner system. The solutions thus obtained from the proposed fourth order theory for different benchmark problems portray the improvement in the accuracy of the numerical results and are well matched with experimental results available in the literature. These results are also compared with second-order PF theory and a comparison study demonstrated the robustness of the proposed model in capturing ductile behaviour close to experimental observations.

퍼지이론을 응용한 조리법에 관한 연구 -비빔밥을 중심으로- (Study on the Recipe Using Fuzzy Theory)

  • 권경순
    • 한국식품영양학회지
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    • 제13권4호
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    • pp.353-359
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    • 2000
  • 본 논문은 퍼지이론을 조리법에 적용함으로써 지금까지 자료조사를 근거로 하여 관능검사를 토대로 제시된 한국요리의 표준화 방법을 체계화하고 쉽게 응용할 수 있도록 하는 방법을 제시하였다. 본 논문에서는 비빔밥을 중심으로 퍼지 이론을 적용하였으며 식품 조리법의 판정기준인 관능지수를 퍼지 이론에 적용하여 추론하는 방법을 제시하였다. 이 방법은 재료의 분량에 따른 관능지수의 변화에 대한 매우 제한적인 경우에 대해서 제시를 했지만 더 많은 재료의 분량 및 조리방법 등을 고려하면 더욱 정확하고 보편적인 관능지수를 직접 조리를 하지 않고 시뮬레이션에 의하여 추론할 수 있다. 본 논문에서는 그 기초적인 연구로 퍼지 이론을 소개하고 비빔밥을 중심으로 기본적인 방법을 제시하였는데 이 퍼지이론의 도입은 조리법의 과학화 및 전산화를 용이하게 하며, 환자의 체계적인 영양관리와 어린이, 노약자 등 식이요법이 필요한 사람들과 조리법이 한정적인 특정지역에 적용하여 다양한 방법을 모색할 수 있을 것으로 생각된다.

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자세와 균형 조절에 관한 연구 (A Study on Control of Posture and Balance)

  • 정동훈;권혁철
    • The Journal of Korean Physical Therapy
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    • 제11권3호
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    • pp.23-36
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    • 1999
  • The very definitions of posture and balance have changed, as has our understanding of the underlying neural mechanisms, In rehabilitation science, there awe at least two different conceptual theories to describe the neural control of posture and balance : the reflex/hierarchical theory and system theory. A reflex/hierarchical theory suggests the posture and balance result from hierarchically organized reflex responses triggered by independent sensory systems. The systems approach suggests that action emerges from an interaction of the individual with the task and environment. That is to say, the systems approach implies that the ability to control our body's position in space emerges from a complex interaction of musculoskeletal and neural systems, collectively referred to as the postural control system. The specific organization of postural systems determined both by the functional task and the environment in which it is being performed, The postural control system is divided into three basic functional components for assessment : 1) musculoskeletal components, 2) motor coordination components, and 3) sensory organization components. It is proposed that a systemic functional understanding of human balance is critical to effective programs for balance rehabilitation. Thus, this article briefly reviews the basic functional components to consider in designing treatment plan and for the benefit of the balance assessment.

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An M/G/1 queue under the $P_{\lambda,\tau}^M$ service policy

  • Kim, Jong-Woo;Lee, Ji-Yeon
    • 한국데이터정보과학회:학술대회논문집
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    • 한국데이터정보과학회 2005년도 춘계학술대회
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    • pp.25-29
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    • 2005
  • We analyze an M/G/1 queueing system under $P_{\lambda,\tau}^M$ service policy. By using the level crossing theory and solving the corresponding integral equations, we obtain the stationary distribution of the workload in the system explicitly.

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정보기술동화의 결정요인 및 기업성과에 미치는 영향 : 혁신확산이론의 관점 (The Determinants of IT Assimilation and Its Effect on Organizational Performance : An Innovation Diffusion Theory Perspective)

  • 곽기영;임소연
    • 한국경영과학회지
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    • 제33권1호
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    • pp.149-168
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    • 2008
  • Many organizations have introduced information technology (IT) as an innovation to gain competitive advantages as business environments have become increasingly complex and rapidly changing. Despite the large investment of IT, there have been mixed results about whether IT creates business values. Considering that IT assimilation may play an important role in explaining IT productivity paradox, this study examines the formation of IT assimilation and its effect on the organizational performance. To do so, this study suggests a research model based on Innovation Diffusion Theory by incorporating organization system, communication channel, change acceptability, and innovation factors, and then attempts to empirically explore the role of IT assimilation for enhanced organizational performance using data collected at the organizational level. Structural equation analysis using AMOS provides significant support for part of proposed relationships. Specifically, we have found encouraging results on the role of IT assimilation by identifying its mediating effect on the organizational performance. Theoretical and practical implications of the findings are discussed accordingly.