• Title/Summary/Keyword: Randomness

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Probabilistic capacity spectrum method considering soil-structure interaction effects (지반-구조물 상호작용 효과를 고려한 확률론적 역량스펙트럼법)

  • Nocete, Chari Fe M.;Kim, Doo-Kie;Kim, Dong-Hyawn;Cho, Sung-Gook
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 2008.04a
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    • pp.65-70
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    • 2008
  • The capacity spectrum method (CSM) is a deterministic seismic analysis approach wherein the expected seismic response of a structure is established as the intersection of the demand and capacity curves. Recently, there are a few studies about a probabilistic CSM where uncertainties in design factors such as material properties, loads, and ground motion are being considered. However, researches show that soil-structure interaction also affects the seismic responses of structures. Thus, their uncertainties should also be taken into account. Therefore, this paper presents a probabilistic approach of using the CSM for seismic analysis considering uncertainties in soil properties. For application, a reinforced concrete bridge column structure is employed as a test model. Considering the randomness of the various design parameters, the structure's probability of failure is obtained. Monte Carlo importance sampling is used as the tool to assess the structure's reliability when subjected to earthquakes. In this study, probabilistic CSM with and without consideration of soil uncertainties are compared and analyzed. Results show that the analysis considering soil structure interaction yields to a greater probability of failure, and thus can lead to a more conservative structural design.

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A Study on Improvement of Halftoning using Random Space Filling Curve (무작위 공간 채움 곡선을 이용한 하프토닝의 개선 방안)

  • Jho, Cheung-Wonn
    • Journal of Digital Convergence
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    • v.12 no.1
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    • pp.415-421
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    • 2014
  • In this paper, we proposed problem and improvement of halftoning using random space filling curve. Random space filling curve is developed as a solution for shortcoming which space filling curve has self-similarity. It is used to reduce regular pattern can be occurred in constant brightness area in order that randomness apply to scanning path. But there is a problem that some area along scanning path can show too bright result in halftoning using random space filling curve. In this paper, we analyzed cause of problem and proposed single pixel error diffusion as a solution method. This method can avoid over-accumulated error and show better result in halftoning.

Design of ceramics powder compaction process parameters (Part Ⅰ : Finite element analysis) (세라믹스 분말 가압 성형 공정 변수 설계(1부: 유한요소 해석))

  • Jung S. C.;Keum Y. T.
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.15 no.1
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    • pp.21-26
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    • 2005
  • In order to simulate the powder compaction process and to assess the effects of packing randomness and particle arrangement 2-dimensional model of rod array compaction using quasi-random multiparticle array is introduced. The elastic modulus of porous ceramics is computed by the homogenization method. With 3 Al₂O₃ and 3 Al particles the compaction processes associated with the porosities are simulated by the explicit finite element method, based on the elastic modulus found by the homogenization method. The simulation results are compared with both previous analytical ones and experimental measurements. Finally, in order to find the relationship between the friction coefficient of powder particles and the relative density, the sensitivity analysis is performed.

Closed-form fragility analysis of the steel moment resisting frames

  • Kia, M.;Banazadeh, M.
    • Steel and Composite Structures
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    • v.21 no.1
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    • pp.93-107
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    • 2016
  • Seismic fragility analysis is a probabilistic decision-making framework which is widely implemented for evaluating vulnerability of a building under earthquake loading. It requires ingredient named probabilistic model and commonly developed using statistics requiring collecting data in large quantities. Preparation of such a data-base is often costly and time-consuming. Therefore, in this paper, by developing generic seismic drift demand model for regular-multi-story steel moment resisting frames is tried to present a novel application of the probabilistic decision-making analysis to practical purposes. To this end, a demand model which is a linear function of intensity measure in logarithmic space is developed to predict overall maximum inter-story drift. Next, the model is coupled with a set of regression-based equations which are capable of directly estimating unknown statistical characteristics of the model parameters.To explicitly address uncertainties arise from randomness and lack of knowledge, the Bayesian regression inference is employed, when these relations are developed. The developed demand model is then employed in a Seismic Fragility Analysis (SFA) for two designed building. The accuracy of the results is also assessed by comparison with the results directly obtained from Incremental Dynamic analysis.

Reducing Test Power and Improving Test Effectiveness for Logic BIST

  • Wang, Weizheng;Cai, Shuo;Xiang, Lingyun
    • JSTS:Journal of Semiconductor Technology and Science
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    • v.14 no.5
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    • pp.640-648
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    • 2014
  • Excessive power dissipation is one of the major issues in the testing of VLSI systems. Many techniques are proposed for scan test, but there are not so many for logic BIST because of its unmanageable randomness. This paper presents a novel low switching activity BIST scheme that reduces toggle frequency in the majority of scan chain inputs while allowing a small portion of scan chains to receive pseudorandom test data. Reducing toggle frequency in the scan chain inputs can reduce test power but may result in fault coverage loss. Allowing a small portion of scan chains to receive pseudorandom test data can make better uniform distribution of 0 and 1 and improve test effectiveness significantly. When compared with existing methods, experimental results on larger benchmark circuits of ISCAS'89 show that the proposed strategy can not only reduce significantly switching activity in circuits under test but also achieve high fault coverage.

A many-objective optimization WSN energy balance model

  • Wu, Di;Geng, Shaojin;Cai, Xingjuan;Zhang, Guoyou;Xue, Fei
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.14 no.2
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    • pp.514-537
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    • 2020
  • Wireless sensor network (WSN) is a distributed network composed of many sensory nodes. It is precisely due to the clustering unevenness and cluster head election randomness that the energy consumption of WSN is excessive. Therefore, a many-objective optimization WSN energy balance model is proposed for the first time in the clustering stage of LEACH protocol. The four objective is considered that the cluster distance, the sink node distance, the overall energy consumption of the network and the network energy consumption balance to select the cluster head, which to better balance the energy consumption of the WSN network and extend the network lifetime. A many-objective optimization algorithm to optimize the model (LEACH-ABF) is designed, which combines adaptive balanced function strategy with penalty-based boundary selection intersection strategy to optimize the clustering method of LEACH. The experimental results show that LEACH-ABF can balance network energy consumption effectively and extend the network lifetime when compared with other algorithms.

A Study on Generation and Types of Mandelbrot Fractal Images (만델브로 프랙탈 이미지의 생성 및 형태 연구)

  • Lim, Mi-Jeong;Cho, Hyong-Je
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.15 no.1
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    • pp.217-222
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    • 2015
  • As a Creative Director one is always looking forward to formative elements of new design. The fractal image that is generated by a computer program instead of by hand suggests a geometric pattern that can grafted into a new design for each field. In this paper we look for information about the creation of a Mandelbrot fractal image that is being utilized in the design of various sectors like textile design, architectural design, exhibition design from pure painting by convergence of both technology and art composites. And it analyses about forms based on the formative principle of creation images.

A Study on Game Dynamics of Battle Royale Genre (배틀로얄 장르의 게임 다이나믹 고찰 -<배틀그라운드>를 중심으로-)

  • Ahn, Jin-kyoung
    • Journal of Korea Game Society
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    • v.17 no.5
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    • pp.27-38
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    • 2017
  • The purpose of this study is to analyze the game dynamics of 'Battle Royale' genre and how these dynamics create dramatic tension, focused on . Battle Royale games maintain the dramatic tension through the intersection of uncertainty and inevitability. Uncertainty is reinforced by randomness of the game world and hidden information of player statement. Inevitability is emerged from the level design with choke point, and restriction of playable field over time. From this mechanism, Battle Royale genre establishes the gameness which derives player's meaningful choice and maintains player's tension until the end of the game.

Reversible Watermarking with Adaptive Embedding Threshold Matrix

  • Gao, Guangyong;Shi, Yun-Qing;Sun, Xingming;Zhou, Caixue;Cui, Zongmin;Xu, Liya
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.10 no.9
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    • pp.4603-4624
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    • 2016
  • In this paper, a new reversible watermarking algorithm with adaptive embedding threshold matrix is proposed. Firstly, to avoid the overflow and underflow, two flexible thresholds, TL and TR, are applied to preprocess the image histogram with least histogram shift cost. Secondly, for achieving an optimal or near optimal tradeoff between the embedding capacity and imperceptibility, the embedding threshold matrix, composed of the embedding thresholds of all blocks, is determined adaptively by the combination between the composite chaos and the average energy of Integer Wavelet Transform (IWT) block. As a non-liner system with good randomness, the composite chaos is suitable to search the optimal embedding thresholds. Meanwhile, the average energy of IWT block is calculated to adjust the block embedding capacity, and more data are embedded into those IWT blocks with larger average energy. The experimental results demonstrate that compared with the state-of-the-art reversible watermarking schemes, the proposed scheme has better performance for the tradeoff between the embedding capacity and imperceptibility.

Fatigue Life Prediction for Automotive Vibroisolating Rubber Component Using Tearing Energy (찢김에너지를 이용한 자동차용 방진 부품의 내구수명 예측)

  • Moon, Hyung-Il;Kim, Ho;Woo, Chang-Soo;Kim, Heon-Young
    • Transactions of the Korean Society of Automotive Engineers
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    • v.20 no.6
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    • pp.100-106
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    • 2012
  • Recently, the demand to acquire and improve durability performance has steadily risen in rubber components design. In design process of a rubber component, an analytical prediction is the most effective way to improve fatigue life. Existing methods of analytical estimation have mainly used an equation for fatigue life obtained from fatigue test data. However, such formula is rarely used due to costs and time required for fatigue testing, as well as randomness of rubber materials. In this paper, we describe fatigue life estimation of rubber component using only the results from a relatively simple tearing test. We estimated fatigue life of the Janggu type fatigue specimen and the automotive motor mount, and evaluated reliability of the proposed method by comparing the estimated values with actual test results.