• Title/Summary/Keyword: Short-term behavior

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Implementation of an Operator Model with Error Mechanisms for Nuclear Power Plant Control Room Operation

  • Suh, Sang-Moon;Cheon, Se-Woo;Lee, Yong-Hee;Lee, Jung-Woon;Park, Young-Taek
    • Proceedings of the Korean Nuclear Society Conference
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    • 1996.05a
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    • pp.349-354
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    • 1996
  • SACOM(Simulation Analyser with Cognitive Operator Model) is being developed at Korea Atomic Energy Research Institute to simulate human operator's cognitive characteristics during the emergency situations of nuclear power plans. An operator model with error mechanisms has been developed and combined into SACOM to simulate human operator's cognitive information process based on the Rasmussen's decision ladder model. The operational logic for five different cognitive activities (Agents), operator's attentional control (Controller), short-term memory (Blackboard), and long-term memory (Knowledge Base) have been developed and implemented on blackboard architecture. A trial simulation with a scenario for emergency operation has been performed to verify the operational logic. It was found that the operator model with error mechanisms is suitable for the simulation of operator's cognitive behavior in emergency situation.

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Prediction of Long-term Behavior of Ground Anchor Based on the Field Monitoring Load Data Analysis (현장 하중계 계측자료 분석을 통한 그라운드 앵커의 장기거동 예측)

  • Park, Seong-yeol;Hwang, Bumsik;Lee, Sangrae;Cho, Wanjei
    • Journal of the Korean Geotechnical Society
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    • v.37 no.8
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    • pp.25-35
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    • 2021
  • Recently, the ground anchor method is commonly applied with nail and rock bolt to secure the stability of slopes and structures in Korea. Among them, permanent anchor which is used for long-term stability should secure bearing capacity and durability during the period of use. However, according to recent studies, phenomenon such as deformation to slope and the reduction of residual tensile load over time have been reported along the long-term behavior of the anchors. These problems of reducing residual tensile load are expected to increase in the future, which will inevitably lead to problems such as increasing maintenance costs. In this study, we identified the factors that affect the tensile load of permanent anchor from a literature study on the domestic and foreign, and investigated the prior studies that analyzed previously conducted load cell monitoring data. Afterwards, using this as basic data, the load cell measurement data collected at the actual site were analyzed to identify the tensile load reduction status of anchors, and the long-term load reduction characteristics were analyzed. Finally, by aggregating the preceding results, proposed a technique to predict the long-term load reduction characteristics of permanent anchors through short-term data to around 100 days after installation.

How Do International Students Idealize Beauty Standards? A Study of Vietnamese Students Living in Korea

  • Woo Bin Kim;Ha Kyung Lee;Yeonghoon Kang
    • Journal of the Korean Society of Clothing and Textiles
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    • v.48 no.2
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    • pp.328-349
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    • 2024
  • In the last decade, Korean culture has progressively facilitated the assimilation of appearance-related norms established by modern Korean society among young generations in Vietnam. Of note, Vietnamese consumers residing in Korea, under the influence of diverse sociocultural factors, are aligning themselves with an ideal standard of Korean beauty through cultural adaptation. This study explores how Vietnamese students internalize Korean beauty standards and the resultant negative behavioral reactions. We investigated the effects of sociocultural pressures (media, in-group, and out-group pressure) on risky appearance management and irrational purchase behavior by mediating sociocultural internalization toward appearance. We tested how the mechanism underlying these variables differs based on how long one has resided in Korea. A total of 213 female participants were surveyed online. The research model was tested using structural equation modeling through AMOS 22.0. The findings show that media and out-group pressure significantly increased sociocultural internalization, which led to consumer behavior in the form of risky appearance management and irrational purchases. The influence of internalization on consumption behavior was stronger for short-term residents of Korea. This study contributes to the literature on acculturation by investigating how foreign consumers accept the host country's ideal beauty standards.

A Study on Brand Identity Revitalization for Aging Brand (노후화된 브랜드의 브랜드 아이덴티티 재활성화(Revitalization)를 위한 연구)

  • Koo, Yoo-Ri
    • Archives of design research
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    • v.19 no.5 s.67
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    • pp.335-350
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    • 2006
  • Due to the development in industrial technology, changes in consumer behavior and aggravating competition within the industry, it is growing only harder every day to build up a strong brand power. Besides, a brand is supposed to age as time goes by, following a brand life cycle, as it is not a solid, immutable asset but something of a living creature. Therefore, self-renovation and revitalization efforts are needed, in order to incessantly confirm the self existence through the relationship with the consumer. In sum, revitalization operation is needed to renew a brand that has grown trite in the passage of time or due to the change in market condition, so as to bring it back anew to the consumers. This study did not stop at measuring the effect of a design renewal as a short-term assignment, but focused on the long-term brand management following the brand life cycle and aimed to define the effective timing and method of revitalization by comprehending the analysis results of consumer consciousness by analyzing the successful cases of brand revitalization and selecting the research analysis targets. As a result, this study proved that a properly-timed brand revitalization efforts in order to cope in advance with predictable changes in environment, can significantly prevent any drop of brand equity from occurring and then extend the brand life cycle. Also, this study could find that a brand revitalization is not a mere concept of a strategy for a short-term sales increase, but should be a long-term strategy to manage a brand, which must be practiced continuously in the time when the brand life cycle curve starts to fall. This research could also confirm that a superficial design renewal, which changes only the packaging of a brand, peformed in short-term haste, is not of help at all.

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A Study on the Dynamic Characteristics of Center Pivot Rocker Arm Type OHC Valve Trains with Hydraulic Lash Adjuster (유압식 밸브 간극 조정장치를 가진 중심지지 로커암형 OHC 밸브기구의 동특성에 관한 연구)

  • 김도중;신병현
    • Transactions of the Korean Society of Automotive Engineers
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    • v.4 no.6
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    • pp.97-108
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    • 1996
  • A modeling technique is proposed for dynamic simulations of OHC valve trains with HLA(hydraulic lash adiuster). HLA is expressed by an air-oil mixture model considering HLA leak-down and aeraton effects. A compact nonlinear equation is derived which describe the short term dynamic behavior of the HLA. Valve spring is analyzed by a distributed parameter model including nonlinear characteristics in the spring surge phenomena. Global behavior of the remaining valve train is expressed by a lumped mass model. The experiental results prove that the simulation model developed here is accurate and useful for the dynamic simulations of OHC valve trains with HLA.

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Two-Dimensional Elasto-Viscoplastic Finite Element Analysis Considering Shield Tunneling Construction Stages (실드터널 시공단계를 고려한 2차원 탄.점소성 유한요소해석)

  • 진치섭;노경배;한상중
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 1996.10a
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    • pp.89-94
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    • 1996
  • The use of shield is increasing day by day, because it's method is advantageous tunneling method to soft and collapsible ground. In case of analyzing shield tunnel by FEM, short term behavior of ground by initial heaving and tail void closure and long terms of it because of consolidation by changes of pore pressures in clay must be considered. In this paper, the shield tunneling construction stages was analyzed from 2 dimensional elasto - viscoplastic finite element program used Mohr - Coulomb yield criterion but not considered the changes of pore pressures. The object of investigation was N - 2 Tunnel. Since the good results of analysis compared to the measured behavior of ground for heaving, tail void closure and liner installation, this results can be applied to design and construction of shield tunneling for the subways, sewage lines etc.

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A Study on Risk Selection Behavior of Japanese Households: Focusing on the relationship between income level and hyperbolic discount (日本家計のリスク選択行動に関する研究 - 所得水準と双曲性の関係を中心に -)

  • Yeom, Dong-ho
    • Analyses & Alternatives
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    • v.4 no.1
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    • pp.105-123
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    • 2020
  • This study analyzes the risk selection behavior of Japanese households. The study approaches the view of 'the hyperbolic discount' which is used in behavioral economics based on the rise in mortgage lending by low-income households in the late 2000s. The study focuses on how households risk preferences vary by income levels. The study analyzes the relationship of attitude of household interest rate risk using Binomial Logistic and Heckman two-step estimation method assuming that there are only two types of Adjustable-Rate Mortgage and Fixed-Rate Mortgage. As a result of the empirical analysis, low-income households annual income tend to have a higher proportion of housing debt as same as higher interest rate risk preferences households in proportion to income growth and interest rate risk preferences. Those results indicate that there is possibility of a hyperbolic discount on low-income households in Japan, and support the hypothesis that low-income households are relatively higher household debt ratio because of high utility due to home purchase in the near future (short-term).

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A Study on Rheological Behavior of Korean Straight Asphalts (국내 스트레이트 아스팔트의 거동 특성 연구)

  • Kim, Nam-Ho;Hwang, Sung-Do;Park, Young-Cheol
    • International Journal of Highway Engineering
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    • v.1 no.2
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    • pp.121-133
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    • 1999
  • This study was based on the evaluation of 9 asphalts that were produced in five major Korean refineries. The study was concentrated to identify the problems of the current asphalt specification (KS M 2201) and to determine the ranges of visco-elastic asphalt behavior. As a conventional asphalt property. asphalt penetration, ring and ball(R&B) softening point, asphalt viscosity, and flash point of asphalt were measured. Also Dynamic Shear Rheometer (DSR) were used to evaluate visco-elastic properties of asphalts in the $-20^{\circ}C$ through $30^{\circ}C$ temperature range. These properties before and after the short-term (RTFO) and long-term (PAV) aging were compared and analyzed to achieve the research objectives. The conclusion from this study can be summarized by the followings. The low temperature rheological behavior of all the straight asphalt from five major Korean refineries is similar regardless of asphalt grade. In the mean while, the rheological behavior at high and intermediate temperature of Korean straight asphalt varies depending on asphalt grade.

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Modified 𝜃 projection model-based constant-stress creep curve for alloy 690 steam generator tube material

  • Moon, Seongin;Kim, Jong-Min;Kwon, Joon-Yeop;Lee, Bong-Sang;Choi, Kwon-Jae;Kim, Min-Chul;Han, Sangbae
    • Nuclear Engineering and Technology
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    • v.54 no.3
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    • pp.917-925
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    • 2022
  • Steam generator (SG) tubes in a nuclear power plant can undergo rapid changes in pressure and temperature during an accident; thus, an accurate model to predict short-term creep damage is essential. The theta (𝜃) projection method has been widely used for modeling creep-strain behavior under constant stress. However, many creep test data are obtained under constant load, so creep rupture behavior under a constant load cannot be accurately simulated due to the different stress conditions. This paper proposes a novel methodology to obtain the creep curve under constant stress using a modified 𝜃 projection method that considers the increase in true stress during creep deformation in a constant-load creep test. The methodology is validated using finite element analysis, and the limitations of the methodology are also discussed. The paper also proposes a creep-strain model for alloy 690 as an SG material and a novel creep hardening rule we call the damage-fraction hardening rule. The creep hardening rule is applied to evaluate the creep rupture behavior of SG tubes. The results of this study show its great potential to evaluate the rupture behavior of an SG tube governed by creep deformation.

Prediction of Reservoir Water Level using CAT (CAT을 이용한 저수지 수위 예측)

  • Jang, Cheol-Hee;Kim, Hyeon-Jun;Kim, Jin-Taek
    • Journal of The Korean Society of Agricultural Engineers
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    • v.54 no.1
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    • pp.27-38
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    • 2012
  • This study is to analyse the hydrological behavior of agricultural reservoir using CAT (Catchment hydrologic cycle Assessment Tool). The CAT is a water cycle analysis model in order to quantitatively assess the characteristics of the short/long-term changes in watershed. It supports the effective design of water cycle improvement facilities by supplementing the strengths and weaknesses of existing conceptual parameter-based lumped hydrologic models and physical parameter-based distributed hydrologic models. The CAT especially supports the analysis of runoff processes in paddy fields and reservoirs. To evaluate the impact of agricultural reservoir operation and irrigation water supply on long-term rainfall-runoff process, the CAT was applied to Idong experimental catchment, operated for research on the rural catchment characteristics and accumulated long term data by hydrological observation equipments since 2000. From the results of the main control points, Idong, Yongdeok and Misan reservoirs, the daily water levels of those points are consistent well with observed water levels, and the Nash-Sutcliffe model efficiencies were 0.32~0.89 (2001~2007) and correlation coefficients were 0.73~0.98.