• Title/Summary/Keyword: Complexity Analysis

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Implemention of the System-Level Multidisciplinary Design Optimization Using the Process Integration and Design Optimization Framework (PIDO 프레임워크를 이용한 시스템 레벨의 선박 최적설계 구현)

  • Park, Jin-Won
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.21 no.5
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    • pp.93-102
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    • 2020
  • The design of large complex mechanical systems, such as automobile, aircraft, and ship, is a kind of Multidisciplinary Design Optimization (MDO) because it requires both experience and expertise in many areas. With the rapid development of technology and the demand to improve human convenience, the complexity of these systems is increasing further. The design of such a complex system requires an integrated system design, i.e., MDO, which can fuse not only domain-specific knowledge but also knowledge, experience, and perspectives in various fields. In the past, the MDO relied heavily on the designer's intuition and experience, making it less efficient in terms of accuracy and time efficiency. Process integration and the design optimization framework mainly support MDO owing to the evolution of IT technology. This paper examined the procedure and methods to implement an efficient MDO with reasonable effort and time using RCE, an open-source PIDO framework. As a benchmarking example, the authors applied the proposed MDO methodology to a bulk carrier's conceptual design synthesis model. The validity of this proposed MDO methodology was determined by visual analysis of the Pareto optimal solutions.

DDC문학류의 조합식 분류시스템 분석 - 20판을 중심으로

  • 윤희윤
    • Journal of Korean Library and Information Science Society
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    • v.20
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    • pp.351-381
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    • 1993
  • The purpose of this study is to analyze the various processes and patterns to build or synthesize class numbers in the 800 class of the Dewey Decimal Classification, Edition 20(1989). The results of the analysis are as follows: 1. The 800(Literature and rhetoric) class in the DDC system is the main class added analytico-synthetic principle positively to an enumerative scheme. 2. The facets to be a n.0, pplied in literature are language literary form literary period ; kind, scope, or medium ; notation 08(collection) or 09(criticism) literary feature, subject, author, etc. 3. In the 800 class, there are the five tables of precedence for literary forms aspects ; specific kinds of persons ; literary, period in relation to the aspects for works treating more than one literary form subforms, aspects and literary periods in the works treating a specific literary form. 4. The basic number synthesis of literary works proceeds through the various facets in the following sequence, as far as necessary for the item : base no. + literary form + literary time or period + kind, scope, or medium + notation 08 or 09 + subform + additional notation from T3C and other tables. 5. In view of the multiplicity of facets, their synthesis formulas take the following order : (1) Works about the literature : base no.(schedule) + language(T6) or form(T3B) (2) Works by or about individual author : base no.(schedule) + form (T3A) + period(schedule) + subform(T3A) (3) Works by or about more than one author, not restricted by language facet : base no.(schedule) + period(T1) ; base no.(schedule) + kind, scope, medium(T3B), or feature(T3C), or person(T5). (4) Works by or about more than one author, restricted by language facet : base no.(schedule) + form (T3B) + period(schedule) + subform(T3B) + notation 08 or 09(T3B) ; base no.(schedule) + notation 08 or 09(T3B) + 9(T3C) + area notation(T2) : base no.(schedule) + form (T3B) + notation 008 or 009(T3B) : base no.(schedule) + form (T3B) + kind, scope, medium(T3B) + notation 08 or 09(T3B) + period(schedule). (5) Affiliated literatures for which period numbers are not us base no.(schedule) + form (T3A or T3B), or notation 08 or 09(T3B) : base no.(schedule) + kind, scope, medium(T3B), feature(T3C), or person(T5) 6. The problems in the number building of the 800 class are the complexity and difficulty of number synthesis, the intrinsic weakness of from distinction and the inconvenience of retrieval inherent in the form class. In order to solve these problems, therefore, the citation orders and methods of DDC should be improved and synthesis patterns simplified from the point of view of its applicability and its usefulness in the "literature class".

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Study of the Process Model through a Case Study of the EU FP 7th International Technological Cooperation - Focusing on the Sub Processes in the Evaluation Process - (EU FP 7차 사례분석을 통해서 살펴본 국제기술협력 프로세스 모형에 관한 연구 -평가단계 하부프로세스를 중심으로-)

  • Kim, Jin Suk
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.15 no.12
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    • pp.7012-7017
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    • 2014
  • The process of international technical cooperation is quite complex. If the complexity is reduced and mirrored as a simple model, it could be of great assistance to government agencies and staff to support international technical cooperation. The purpose of this paper was to develop the underlying process model in international technical cooperation in the evaluation phase. The paper provides in the second chapter the theoretical background for developing a process model. In the third chapter, the features and the practical model of the evaluation phase are presented. Chapter four presents a case with substantial empirical analysis of the development model. EU FP7th as a case study was examined in the hindsight of international technical cooperation in the evaluation process. The concluding, chapter five, presents the limitations and future research directions. The results show that a new phase can be analyzed on the level of the evaluation step. The limitation of this study was that the empirical study consists of a single case study only. In the future, it will be necessary to study the sub stages of other steps in international technological cooperation.

A Multipurpose Design Framework for Hardware-Software Cosimulation of System-on-Chip (시스템-온-칩의 하드웨어-소프트웨어 통합 시뮬레이션을 위한 다목적 설계 프레임워크)

  • Joo, Young-Pyo;Yun, Duk-Young;Kim, Sung-Chan;Ha, Soon-Hoi
    • Journal of KIISE:Computer Systems and Theory
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    • v.35 no.9_10
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    • pp.485-496
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    • 2008
  • As the complexity of SoC (System-on-Chip) design increases dramatically. traditional system performance analysis and verification methods based on RTL (Register Transfer Level) are no more valid for increasing time-to-market pressure. Therefore a new design methodology is desperately required for system verification in early design stages. and hardware software (HW-SW) cosimulation at TLM (Transaction Level Modeling) level has been researched widely for solving this problem. However, most of HW-SW cosimulators support few restricted ion levels only, which makes it difficult to integrate HW-SW cosimulators with different ion levels. To overcome this difficulty, this paper proposes a multipurpose framework for HW SW cosimulation to provide systematic SoC design flow starting from software application design. It supports various design techniques flexibly for each design step, and various HW-SW cosimulators. Since a platform design is possible independently of ion levels and description languages, it allows us to generate simulation models with various ion levels. We verified the proposed framework to model a commercial SoC platform based on an ARM9 processor. It was also proved that this framework could be used for the performance optimization of an MJPEG example up to 44% successfully.

On Enhancing Safety of Train-Centric Train Control System using Model-Based Development (차상중심 열차제어시스템 개발에서 모델기반 접근을 통한 안전성 향상에 관한 연구)

  • Choi, Myung-Sung;Kim, Joo-Uk;Han, Seok-Youn;Oh, Se-Chan;Sim, Sang-Hyun;Lee, Jae-Chon
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.17 no.7
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    • pp.573-584
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    • 2016
  • The train control system is a facility to ensure model-based design and safe train operation, and its safety is the most important factor for system introduction, complexity of the design information and traceability etc. Therefore, the model-based design and safety activities regarding the way-side equipment of a train control system is also highlighted. To solve this problem, In this paper, model-based design was carried out first to develop an effective train control system, which is represented by SysML(System Modeling Language). The test scenarios that can take advantage of the design model were created to improve the train safety control system. Case studies of a model-based design of a train-centric train control system were applied to the test scenarios; the results demonstrated its usability. The improved activity over the test highlighted the safety improvement approach, and it is expected to reduce the cost and time in the conceptual design of a future development model-based train control system.

A Study on the Energy Efficient Data Aggregation Method for the Customized Application of Underwater Wireless Sensor Networks (특정 응용을 위한 수중센서네트워크에서 에너지 효율적인 데이터통합 방법 연구)

  • Kim, Sung-Un;Park, Seon-Yeong;Yu, Hyung-Cik
    • Journal of Korea Multimedia Society
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    • v.14 no.11
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    • pp.1438-1449
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    • 2011
  • UWSNs(Underwater Wireless Sensor Networks) need effective modeling fitted to the customized type of application and its covering area. In particular it requires an energy efficient data aggregation method for such customized application. In this paper, we envisage the application oriented model for monitoring the pollution or intrusion detection over a given underwater area. The suggested model is based on the honeycomb array of hexagonal prisms. In this model, the purpose of data aggregation is that the head node of each layer(cluster) receives just one event data arrived firstly and transfer this and its position data to the base station effectively in the manner of energy efficiency and simplicity without duplication. Here if we apply the existent data aggregation methods to this kind of application, the result is far from energy efficiency due to the complexity of the data aggregation process based on the shortest path or multicast tree. In this paper we propose three energy efficient and simple data aggregation methods in the domain of cluster and three in the domain of inter-cluster respectively. Based on the comparative performance analysis of the possible combination pairs in the two domains, we derive the best energy efficient data aggregation method for the suggested application.

Comparison of Newton's and Euler's Algorithm in a Compound Pendulum (복합진자 모형의 뉴튼.오일러 알고리즘 비교)

  • Hah, Chong-Ku
    • Korean Journal of Applied Biomechanics
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    • v.16 no.3
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    • pp.1-7
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    • 2006
  • The Primary type of swinging motion in human movement is that which is characteristic of a pendulum. The two types of pendulums are identified as simple and compound. A simple pendulum consist of a small body suspended by a relatively long cord. Its total mass is contained within the bob. The cord is not considered to have mass. A compound pendulum, on the other hand, is any pendulum such as the human body swinging by hands from a horizontal bar. Therefore a compound pendulum depicts important motions that are harmonic, periodic, and oscillatory. In this paper one discusses and compares two algorithms of Newton's method(F = m a) and Euler's method (M = $I{\times}{\alpha}$) in compound pendulum. Through exercise model such as human body with weight(m = 50 kg), body length(L = 1.5m), and center of gravity ($L_c$ = 0.4119L) from proximal end swinging by hands from a horizontal bar, one finds kinematic variables(angle displacement / velocity / acceleration), and simulates kinematic variables by changing body lengths and body mass. BSP by Clauser et al.(1969) & Chandler et al.(1975) is used to find moment of inertia of the compound pendulum. The radius of gyration about center of gravity (CoG) is $k_c\;=\;K_c{\times}L$ (단, k= radius of gyration, K= radius of gyration /segment length), and then moment of inertia about center of gravity(CoG) becomes $I_c\;=\;m\;k_c^2$. Finally, moment of inertia about Z-axis by parallel theorem becomes $I_o\;=\;I_c\;+\;m\;k^2$. The two-order ordinary differential equations of models are solved by ND function of numeric analysis method in Mathematica5.1. The results are as follows; First, The complexity of Newton's method is much more complex than that of Euler's method Second, one could be find kinematic variables according to changing body lengths(L = 1.3 / 1.7 m) and periods are increased by body length increment(L = 1.3 / 1.5 / 1.7 m). Third, one could be find that periods are not changing by means of changing mass(m = 50 / 55 / 60 kg). Conclusively, one is intended to meditate the possibility of applying a compound pendulum to sports(balling, golf, gymnastics and so on) necessary swinging motions. Further improvements to the study could be to apply Euler's method to real motions and one would be able to develop the simulator.

Factors Influencing the Introduction of Mobile Security Technology (기업 모바일 보안기술 도입에 영향을 미치는 특성요인)

  • Choi, Woong-Gyu;Lee, Young-Jai
    • The Journal of Society for e-Business Studies
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    • v.18 no.4
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    • pp.215-240
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    • 2013
  • This research has reviewed the major composition concepts and the positive research results in the selected studies which were theoretically based on IDT (Innovation Diffusion Theory), IRM (Model of Innovation Resistance), TAM(Technology Acceptance Model), and IAPA(Information Asset Protection Activity) in order to improve the theoretical explanation of major characterized factors influencing on the introduction of MST (Mobile Security Technology). The characterized factors for the adaptation of MST and 17 hypotheses on the MST study models in order to test the effects on the intention to use are empirically verified by utilizing the analysis method of structure equation model. As a result of a study, First, the most influential characterized factors of IRM are shown as compatibility, complexity, relative advantage, information asset protection in order. Second, the characterized factors affecting intention to use are shown as relative advantage, compatibility, innovation resistance, performance expectancy. The results of this study are relevantly significant to establish the theoretical foundation of the study on the adaptation of MST and The verification of the characterized factors provide strategic implication for the introduction of MST and policy direction which alleviates informational gap between new MST and previous Security Technology to diffusion agency.

Digital Creative Labour -A Perspective of the Ethics of Labour and Subjectivity of the Younger Generation in Korea (디지털 창의노동 -젊은 세대의 노동 윤리와 주체성에 관한 한 시각)

  • Kim, Yeran
    • Korean journal of communication and information
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    • v.69
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    • pp.71-110
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    • 2015
  • Beyond the technological behaviorism-oriented notion of prosumers, the current study explores the question of digital creative labour of the youth in the interrelated context of post-capitalist crisis and neoliberal ethos of selfhood. This analysis is situated particularly in the social conflicts and struggles in Korea, where the problems related to the precarization of the younger generation have been increasingly aggravated (in the realm of embodied reality) whereas their digital activities have been highly expressive (in the realm of mediated reality). The contradictions embedded in the question of the labour of the youth are delineated in the respect of the subjectivities of young free labour, or 'digital creative labour' in proposed terms: the precarious young free labour in Korea is the compound of social fragmentation, economic polarization, expansion of cognitive and emotion labour, boom of hedonistic consumerism, economic-cultural celebration of creativity and self-entrepreneurship, technological saturation of digital media, subjective/collective affects around excitement and ambition but also of anxiety and fear. The ambivalence and complexity of the young free labour is converged at the emergence of homo-economicus (Michel Foucault) through the subjectivation of the social (con)fusion of post-capitalist crisis and neoliberal governmentality of selfhood.

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Distributed Alamouti Space Time Block Coding Based On Cooperative Relay System (협동 중계 시스템을 이용한 분산 Alamouti 시공간 블록 부호)

  • Song, Wei;Cho, Kye-Mun;Lee, Moon-Ho
    • Journal of the Institute of Electronics Engineers of Korea TC
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    • v.46 no.9
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    • pp.16-23
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    • 2009
  • In this paper, we propose a new distributed Alamouti space-time block coding scheme using cooperative relay system composed of one source node, three relay nodes and one destination node. The source node is assumed to be equipped with two antennas which respectively use a 2-beam array to communicate with two nodes selected from the three relay nodes. During the first time slot, the two signals which respectively were transmitted by one antenna at the source, are selected by one relay node, added, amplified, and forwarded to the destination. During the second time slot, the other two relay nodes implement the conjugate and minusconjugate operations to the two received signals, respectively, each in turn is amplified and forwarded to the destination node. This transmission scheme represents a new distributed Alamouti space-time block code that can be constructed at the relay-destination channel. Through an equivalent matrix expression of symbols, we analyze the performance of this proposed space-time block code in terms of the chernoff upper bound pairwise error probability (PEP). In addition, we evaluate the effect of the coefficient $\alpha$ ($0{\leq}{\alpha}{\leq}1$) determined by power allocation between the two antennas at the source on the received signal performance. Through computer simulation, we show that the received signals at the three relays have same variance only when the value of $\alpha$ is equal to $\frac{2}{3}$, as a consequence, a better performance is obtained at the destination. These analysis results show that the proposed scheme outperforms conventional proposed schemes in terms of diversity gain, PEP and the complexity of relay nodes.