• Title/Summary/Keyword: accumulation model

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Coupling effects between wind and train transit induced fatigue damage in suspension bridges

  • Petrini, Francesco;Olmati, Pierluigi;Bontempi, Franco
    • Structural Engineering and Mechanics
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    • v.70 no.3
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    • pp.311-324
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    • 2019
  • Long-span steel suspension bridges develop significant vibrations under the effect of external time-variable loadings because their slenderness. This causes significant stresses variations that could induce fatigue problems in critical components of the bridge. The research outcome presented in this paper includes a fatigue analysis of a long suspension bridge with 3300 meters central suspended span under wind action and train transit. Special focus is made on the counterintuitive interaction effects between train and wind loads in terms of fatigue damage accumulation in the hanger ropes. In fact the coupling of the two actions is shown to have positive effects for some hangers in terms of damage accumulation. Fatigue damage is evaluated using a linear accumulation model (Palmgren-Miner rule), analyses are carried out in time domain by a three-dimensional non-linear finite element model of the bridge. Rational explanation regarding the above-mentioned counterintuitive behavior is given on the basis of the stress time histories obtained for pertinent hangers under the effects of wind and train as acting separately or simultaneously. The interaction between wind and train traffic loads can be critical for a some hanger ropes therefore interaction phenomena within loads should be considered in the design.

Analysis of fatigue crack growth using fictitious crack model (가상균열 모델을 이용한 피로균열 진전 해석)

  • Yang Seung-Yong;Goo Byeong-choon
    • Proceedings of the KSR Conference
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    • 2003.10c
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    • pp.79-84
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    • 2003
  • A fictitious crack model was used to analyze fatigue crack growth under the influence of residual stress. In the fictitious crack model, crack is represented in terms of the separation of two adjacent interfaces and the constitutive equation between the separation and traction is assumed. The effect of fatigue loading was included in the constitutive equation by considering damage accumulation in the cohesive zone. To investigate the effect of the residual stress on the fatigue crack growth, we calculated the residual stress distribution due to transient heat flux to the specimen by finite element method. Fatigue crack growth was simulated by the fictitious crack model with repeated loading. The mode-I crack growth rates were compared for the cases with and without the compressive residual stress around the crack tip. It was observed that the mode-I crack growth can be suppressed by compressive residual stress.

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Virtual Fitting System Using Deep Learning Methodology: HR-VITON Based on Weight Sharing, Mixed Precison & Gradient Accumulation (딥러닝 의류 가상 합성 모델 연구: 가중치 공유 & 학습 최적화 기반 HR-VITON 기법 활용)

  • Lee, Hyun Sang;Oh, Se Hwan;Ha, Sung Ho
    • The Journal of Information Systems
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    • v.31 no.4
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    • pp.145-160
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    • 2022
  • Purpose The purpose of this study is to develop a virtual try-on deep learning model that can efficiently learn front and back clothes images. It is expected that the application of virtual try-on clothing service in the fashion and textile industry field will be vitalization. Design/methodology/approach The data used in this study used 232,355 clothes and product images. The image data input to the model is divided into 5 categories: original clothing image and wearer image, clothing segmentation, wearer's body Densepose heatmap, wearer's clothing-agnosting. We advanced the HR-VITON model in the way of Mixed-Precison, Gradient Accumulation, and sharing model weights. Findings As a result of this study, we demonstrated that the weight-shared MP-GA HR-VITON model can efficiently learn front and back fashion images. As a result, this proposed model quantitatively improves the quality of the generated image compared to the existing technique, and natural fitting is possible in both front and back images. SSIM was 0.8385 and 0.9204 in CP-VTON and the proposed model, LPIPS 0.2133 and 0.0642, FID 74.5421 and 11.8463, and KID 0.064 and 0.006. Using the deep learning model of this study, it is possible to naturally fit one color clothes, but when there are complex pictures and logos as shown in <Figure 6>, an unnatural pattern occurred in the generated image. If it is advanced based on the transformer, this problem may also be improved.

The Human Capital Accumulation Effect of New and Renewable Energy Human Resource Development Programs (신재생에너지 인력양성의 인적자본 축적 효과)

  • Lee, You-Ah;Kim, Jin-Soo;Heo, Eun-Nyeong
    • New & Renewable Energy
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    • v.5 no.3
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    • pp.49-55
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    • 2009
  • Human resource for the new and renewable energy technology is an important factor in the respect of the sustainable growth and energy security. In this paper, we focused on measuring the economic effect of human resource development on new and renewable energy development programs. The human capital accumulation model developed by Mincer (1974) was modified in terms of the rate of the researchers' investment in human capital. As a result of a empirical case study, the value of human capital was estimated by 102 million Korean won per year worth 18% of the project labor cost. In case of the assumption of 100% participation of researchers, the level of human capital accumulation increased to 914 million Korean won per year. These results imply that the new and renewable energy development programs has been successful, on the concept of learning by doing, in terms of providing the researchers with opportunities to accumulate human capital.

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EMG Pattern Recognition based on Evidence Accumulation for Prosthesis Control

  • Lee, Seok-Pil;Park, Sand-Hui
    • Journal of Electrical Engineering and information Science
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    • v.2 no.6
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    • pp.20-27
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    • 1997
  • We present a method of electromyographic(EMG) pattern recognition to identify motion commands for the control of a prosthetic arm by evidence accumulation with multiple parameters. Integral absolute value, variance, autoregressive(AR) model coefficients, linear cepstrum coefficients, and adaptive cepstrum vector are extracted as feature parameters from several time segments of the EMG signals. Pattern recognition is carried out through the evidence accumulation procedure using the distances measured with reference parameters. A fuzzy mapping function is designed to transform the distances for the application of the evidence accumulation method. Results are presented to support the feasibility of the suggested approach for EMG pattern recognition.

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Estimation of Nutrients Transport in Kamak Bay using the Eco-hydrodynamic Model (생태계모델을 이용한 가막만의 영양염 거동 특성 평가)

  • 김동명
    • Journal of Environmental Science International
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    • v.12 no.7
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    • pp.745-751
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    • 2003
  • The three-dimensional eco-hydrodynamic model was applied to estimate the physical process in terms of nutrients and net uptake(or regeneration) rate of nutrients in Kamak Bay for scenario analysis to find proper management plan. The estimation results of the physical process in terms of nutrients shelved that transportation of nutrients is dominant in surface level while accumulation of nutrients is dominant in bottom level. In the case of dissolved inorganic nitrogen, the results showed that the net uptake rate was 0∼60 mg/㎡/day in surface level(0∼3m), and the net regeneration rate was 0.0∼10.0 mg/㎡/day in middle level(3∼6m) and above 10mg/㎡/day in bottom level(6m∼below). In the case of dissolved inorganic phosphorus, the net uptake rate was 0.0∼3.0 mg/㎡/day in surface level, and the net regeneration rate was 0.5∼1.5 mg/㎡/day in middle level and 1.0∼3.0 mg/㎡/day in bottom level. These results indicates that net uptake and transport of nutrients are occurred predominantly at the surface level and the net generation and accumulation are dominant at bottom level. Therefore, it is important to consider the re-supplement of nutrients due to regeneration of bottom water.

A Study on the Accumulation Phenomena of Oxidized Starch in White Water in Closed Fine Papermaking Process (Part 1) -Effect of Papermaking system closure- (백상지 공정 폐쇄화에 따른 백수 내 산화전분의 축적 현상에 관한 연구 (제1보) -공정 폐쇄화의 영향-)

  • Ahn, Hyun-Kyun;Lee, Hak-Lae
    • Journal of Korea Technical Association of The Pulp and Paper Industry
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    • v.36 no.3
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    • pp.15-34
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    • 2004
  • Diverse benefits such as reduction of fresh water consumption and effluent discharge, efficient use of raw materials and energy savings can be obtained by papermaking system closure. Closure of papermaking processes, however, causes many problems including reduction of the efficiency of additives, decrease of retention and dewatering, felt plugging, poor Paper quality, generation of slime and odor, poor vacuum efficiency, etc, and it has been recognized that accumulation of Inorganic and organic substances in the process white water is the prime cause of these problems. Therefore, technological developments for preventing accumulation of these detrimental substances are urgently required for Implementing papermaking system closure. Understanding of the accumulation phenomena of the inorganic and organic substances in the papermaking process white water is prerequisite for papermaking system closure. In this study a process simulation method was used to analyze the accumulation phenomena of anionic starch In the process white water as the closure level of a fine paper making process is increased. A pilot paper machine was used as a model process. Starch adsorption and desorption models were developed based on the concept of starch adsorption ratio, which was not considered in previous studies. Steady state simulation studies were carried out based on this model using a commercial simulator. In steady state simulation, the variation of dissolved starch concentration in each process unit was monitored as a function of white water usage for wire shower. The result of the steady state simulation showed that dissolved starch concentration and its increase ratio in Process units increased as white water usage ratio for wire shower increased.

Fermented Soymilk Alleviates Lipid Accumulation by Inhibition of SREBP-1 and Activation of NRF-2 in the Hepatocellular Steatosis Model

  • Ahn, Sang Bong;Wu, Wen Hao;Lee, Jong Hun;Jun, Dae Won;Kim, Jihyun;Kim, Riji;Lee, Tae-bok;Jun, Jin Hyun
    • Journal of Microbiology and Biotechnology
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    • v.28 no.2
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    • pp.236-245
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    • 2018
  • Ingredients of soy and fermented soy products have been widely utilized as food supplements for health-enhancing properties. The aim of this study was to evaluate the effects of fermented soymilk (FSM) and soymilk (SM) on free fatty acid-induced lipogenesis in the hepatocellular steatosis model. HepG2 cells were incubated with palmitic acid (PA) for 24 h to induce lipogenesis and accumulation of intracellular lipid contents. The PA-treated cells were co-incubated with FSM, SM, genistein, and estrogen, respectively. Lipid accumulation in the PA-treated HpG2 cells was significantly decreased by co-incubation with FSM. Treatment of HepG2 cells with PA combined with genistein or estrogen significantly increased the expression of SREBP-1. However, FSM co-incubation significantly attenuated SREBP-1 expression in the PA-treated HepG2 cells; in addition, expression of NRF-2 and phosphorylation of ERK were significantly increased in the PA and FSM co-incubated cells. PA-induced ROS production was significantly reduced by FSM and SM. Our results suggested that the bioactive components of FSM could protect hepatocytes against the lipid accumulation and ROS production induced by free fatty acids. These effects may be mediated by the inhibition of SREBP-1 and the activation of NRF-2 via the ERK pathway in HepG2 cells.

Repair Accumulation Cost for the Long-Term Repair Plan in Multifamily Housing Using the Forecasting Model of the Repair Cost (공종별 수선비용 추계모델을 활용한 공동주택 장기수선충당금 적립금액 산정)

  • Lee, Kang-Hee;Chae, Chang-U
    • KIEAE Journal
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    • v.16 no.3
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    • pp.137-143
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    • 2016
  • Purpose: Apartment housing should conduct a cyclic repair to keep and maintain the building performance since they are constructed. Therefore, the repair plan would be provided for long term period which explains the repair time, items and repair cost. Residents of apartment housing are responsible to pay for the repair activities. For repair cost, residents would reserve the money for repair little by little continuously until the required repair time because the repair cost takes a big burden for residents and lots of money a time. But, there is no systematic approach to provide the long term repair cost because it is no proper forecast of the repair cost to the upcoming repair time. In this study, it aimed at providing the monthly accumulation of the long term repair cost with the survey data in Seoul. Method: For these, the surveyed data are classified into 6 categories and number of data are 1,918. In addition, it developed the repair cost model for the 24 repair works and the cumulation function which is reflected with the each cost model. Result: This study are shown as follows : First, among the various estimation for the repair cost, the power function has a goodness of fit in statistics. Second, the monthly accumulation would be 12,840 won/household in size of $100,000m^2$ management area and $81.7won/m^2$ in size of the 1,000 household number during 40 years.

Feasible monitoring of the inhibitory effects of free NH3 on NO2- oxidation

  • Yoo, Byeong-Hak;Lee, Sang-hun
    • Geosystem Engineering
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    • v.21 no.5
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    • pp.243-250
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    • 2018
  • This study investigated nitrite ($NO_2{^-}$) accumulation due to FA (Free Ammonia: $NH_3$) inhibition in an anaerobic-aerobic-anoxic (AOA) process reactor to mainly treat wastewater containing 302-610 mg/L of $NH_3/NH_4{^+}-N$. Based on an experimental operation focusing on the nitrification, it was observed that $NO_2{^-}$ was accumulated in the aerobic nitrification zone as pH increased, due to inhibition of $NO_2{^-}$ conversion to $NO_3{^-}$ by FA. This result implied FA inhibition to NOB ($NO_2{^-}$-Oxidizing Bacteria) for converting $NO_2{^-}$ to $NO_3{^-}$. The objective of this study is to develop a feasible monitoring procedure for early detection of the FA inhibition toward $NO_2{^-}$ accumulation and poor nitrification. Thus, in order to rapidly assess FA concentrations, an $NH_3$ probe was utilized to measure $NH_3$ concentrations together with applying a simple model prediction using the measured $NH_4{^+}$ concentrations, the Henry's law constant of $NH_3$ and measured pH. The predictive model $NH_3$ levels were verified by a good correlation (89%) with the corresponding measured data, but the model prediction underestimated FA concentrations at less than 7.4 and a little overestimated at pH above 7.5. Interestingly, accumulated $NO_2{^-}$ levels were roughly correlated with FA levels that were observed at delayed time points. This reflects the detected FA levels can be good indicators of $NO_2{^-}$ levels with some delayed time. $NO_2{^-}$ accumulation started at measured FA concentrations of higher than approximately 3 mg/L and ceased below that FA level.