• 제목/요약/키워드: Uncertainty Process

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Some Properties of Complex Uncertain Process

  • You, Cuilian;Xiang, Na
    • Industrial Engineering and Management Systems
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    • v.15 no.2
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    • pp.143-147
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    • 2016
  • Uncertainty appears not only in real quantities but also in complex quantities. Complex uncertain process is essentially a sequence of complex uncertain variables indexed by time. In order to describe complex uncertain process, a formal definition of complex uncertain distribution is given in this paper, as well as the concepts of independence and variance. In addition, some properties of complex uncertain integral are presented.

A fuzzy SOC based pressure tracking controller design for hydroforming process (Fuzzy SOC를 이용한 하이드로 포밍 고정의 압력제어기 설계)

  • 김문종;박희재;조형석
    • 제어로봇시스템학회:학술대회논문집
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    • 1990.10a
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    • pp.350-355
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    • 1990
  • A pressure tracking of hydroforming process is considered in this paper. To account for nonlinearities and uncertainty of the process. A fuzzy SOC based iterative learning control algorithm is proposed. A series of experimentals were performed for the pressure tracking control of the process. The experimental results show that regardless of inherent nonlinearties and uncertainties associated with hydraulic system. A good pressure tracking control performance is obtained using the proposed fuzzy learning control algorithm.

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The Relationship between Intolerance of Uncertainty and Relationship Addiction: The Mediating Effect of Experiential Avoidance (미혼남녀의 불확실성에 대한 인내력 부족과 관계중독의 관계에 관한 연구: 경험회피의 매개효과)

  • Gayeon Kim;Jeoungyun Park
    • Korean Journal of Culture and Social Issue
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    • v.30 no.2
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    • pp.221-238
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    • 2024
  • The purpose of this study was to explore the effects of intolerance of uncertainty and experiential avoidance on relationship addiction and to investigate the mediating effect of experiential avoidance in the relationship between intolerance of uncertainty and relationship addiction among unmarried adults. For this purpose, an online survey was conducted on unmarried adults aged 20 to 29 who are currently engaged in opposite-sex romantic relationships, and a total of 302 data were used for analysis.. The collected data were analyzed using SPSS 29.0 and PROCESS MACRO v4.2. The main results of this study are as follows. First, intolerance of uncertainty and experiential avoidance had significant effects on relationship addiction. Second, experiential avoidance had a significant mediating effect between intolerance of uncertainty and relationship addiction tendencies. This study identified individual psychological factors that induce relationship addiction. Based on the research results, this study suggests directions for counseling interventions to reduce relationship addiction tendencies and promote healthier relationship patterns among unmarried adults.

Development of Technology Roadmaps under Uncertainty (불확실한 환경에서의 효과적 기획을 위한 시나리오 기반 기술로드맵 프로세스의 개발)

  • Jeon, Jeongwhan;Geum, Youngjung
    • Journal of Korea Technology Innovation Society
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    • v.18 no.3
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    • pp.492-515
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    • 2015
  • Consideration of uncertainty has been considered to be an important factor in technology planning due to the fast changes of technologies and customer needs. Therefore, how to consider uncertainty has been a promising issue in developing and utilizing the technology roadmap, a prominent tool for the technology planning. However, previous studies regarding technology roadmaps are based on practical case studies for specific certain industries, which are of course useful but sometimes lack systematic frameworks and methodologies. In response, this study suggests a framework to identify possible scenario elements, analyze the impact of each scenario element and reflect the results to the technology roadmapping process. For this purpose, this study suggests a QFD-based framework that evaluates the relationship between scenario elements and the planning elements, and proposes a basic structure of scenario-based technology roadmaps to reflect the evaluation results to the technology roadmapping process.

A Method to Predict the Feasible Region of Geometric Centroid for Closed Hull Form Area Using Regression Analysis (회귀분석을 통한 선형 단면의 변환가능 중점영역 예측)

  • Nguyen, Si Bang;Nam, Jong-Ho;Lee, Minkyu
    • Journal of the Society of Naval Architects of Korea
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    • v.54 no.5
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    • pp.387-392
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    • 2017
  • There is a constant demand for hull variation related to ship design. Various input variables are generally given to achieve the objective functions assigned by each variation process. When dealing with geometric shapes accompanied by nonlinear operations during the variation process, vague relationships or uncertainties among input variables are commonly observed. Therefore, it is strongly recommended to identify those uncertainty factors in advance. A method to modify the shape of a closed hull form with a new area and a centroid had been introduced as a new process of hull variation. Since uncertainty between input variables still existed in the method, however, it was not easy for the user to enter the area and the corresponding centroid. To overcome this problem, a method is presented in this paper to provide the feasible region of centroids for a given area. By utilizing the concept and techniques used in the statistics such as the number of samples, probability, margin error, and level of confidence, this method generates the distribution of possible centroids along the regression curve. The result shows that the method helps the user to choose an appropriate input value following his or her design intention.

Cloud Removal Using Gaussian Process Regression for Optical Image Reconstruction

  • Park, Soyeon;Park, No-Wook
    • Korean Journal of Remote Sensing
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    • v.38 no.4
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    • pp.327-341
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    • 2022
  • Cloud removal is often required to construct time-series sets of optical images for environmental monitoring. In regression-based cloud removal, the selection of an appropriate regression model and the impact analysis of the input images significantly affect the prediction performance. This study evaluates the potential of Gaussian process (GP) regression for cloud removal and also analyzes the effects of cloud-free optical images and spectral bands on prediction performance. Unlike other machine learning-based regression models, GP regression provides uncertainty information and automatically optimizes hyperparameters. An experiment using Sentinel-2 multi-spectral images was conducted for cloud removal in the two agricultural regions. The prediction performance of GP regression was compared with that of random forest (RF) regression. Various combinations of input images and multi-spectral bands were considered for quantitative evaluations. The experimental results showed that using multi-temporal images with multi-spectral bands as inputs achieved the best prediction accuracy. Highly correlated adjacent multi-spectral bands and temporally correlated multi-temporal images resulted in an improved prediction accuracy. The prediction performance of GP regression was significantly improved in predicting the near-infrared band compared to that of RF regression. Estimating the distribution function of input data in GP regression could reflect the variations in the considered spectral band with a broader range. In particular, GP regression was superior to RF regression for reproducing structural patterns at both sites in terms of structural similarity. In addition, uncertainty information provided by GP regression showed a reasonable similarity to prediction errors for some sub-areas, indicating that uncertainty estimates may be used to measure the prediction result quality. These findings suggest that GP regression could be beneficial for cloud removal and optical image reconstruction. In addition, the impact analysis results of the input images provide guidelines for selecting optimal images for regression-based cloud removal.

A Study on the Effect of Experience-specificity and Uncertainty on Choice in Experiential Products -From Transaction Cost Perspective- (경험재 거래의 경험특유성, 불확실성이 선택에 주는 영향에 관한 연구 -거래비용적 관점에서-)

  • Jeong, Yun-Hee;Park, JI-Yeon
    • Journal of Convergence for Information Technology
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    • v.9 no.4
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    • pp.152-159
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    • 2019
  • The purpose of this study is to investigate the effect of transaction characteristics on transaction cost and choice intention by applying transaction cost theory to experiential product. Experience-specificity, transaction uncertainty, and personal uncertainty are proposed to reflect the characteristics of experiential products, and the effects of these variables on transaction costs and transaction costs are assumed to have an influence on the choice intention. The results of this study are summarized as follows. First, experience-specificity(site, physical equipment, knowledge skill, temporal), transactional uncertainty(product-, process-), personal uncertainty (preference-, and situation-) have a significant positive effect on transaction cost. Second, transaction costs (search, comparison, examination, negotiation, payment, delivery) have a significant negative effect on the choice intention of the experiential product. The results of this study show that the increase of transaction costs can reduce the choice of experiential products and the strategic consideration of experience specificity, transaction uncertainty and individual uncertainty are required to reduce transaction costs. In addition, experiential products lacked access from a transactional and cost-based point of view, and this study contributes theoretically by compensating for the lack.

Identification of Uncertainty on the Reduction of Dead Storage in Soyang Dam Using Bayesian Stochastic Reliability Analysis (Bayesian 추계학적 신뢰도 기법을 이용한 소양강댐 퇴사용량 감소의 불확실성 분석)

  • Lee, Cheol-Eung;Kim, Sang Ug
    • Journal of Korea Water Resources Association
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    • v.46 no.3
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    • pp.315-326
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    • 2013
  • Despite of the importance on the maintenance of a reservoir storage, relatively few studies have addressed the stochastic reliability analysis including uncertainty on the decrease of the reservoir storage by the sedimentation. Therefore, the stochastic gamma process under the reliability framework is developed and applied to estimate the reduction of the Soyang Dam reservoir storage in this paper. Especially, in the estimation of parameters of the stochastic gamma process, the Bayesian MCMC scheme using informative prior distribution is used to incorporate a wide variety of information related with the sedimentation. The results show that the selected informative prior distribution is reasonable because the uncertainty of the posterior distribution is reduced considerably compared to that of the prior distribution. Also, the range of the expected life time of the dead storage in Soyang Dam reservoir including uncertainty is estimated from 119.3 years to 183.5 years at 5% significance level. Finally, it is suggested that the improvement of the assessment strategy in this study can provide the valuable information to the decision makers who are in charge of the maintenance of a reservoir.

A Moderating Role of Personal Need for Structure on the Effects of Process versus Outcome Simulations on the Evaluation of Really New Products

  • Kim, Jun San;Hahn, Minhi;Yoon, Yeosun
    • Asia Marketing Journal
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    • v.14 no.4
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    • pp.77-94
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    • 2013
  • Really new products (RNPs) provide novel benefits yet many consumers are reluctant to accept these highly innovative new products. Previous literature has shown that mental simulation is an effective method for enhancing the evaluation of RNPs. However, Castano et al. (2008) and Zhao, Hoeffler, and Zauberman (2011) demonstrate conflicting results as to which type of mental simulation (i.e., process versus outcome) is more effective for the enhancement of RNP evaluation. The authors try to reconcile these results by incorporating a moderating variable which is personal need for structure (PNS). PNS is an individual difference variable that taps the differences in people's propensity to cognitively structure and simplify their environment (Neuberg and Newsom 1993). From the analysis of the previous two works, the authors point out that consumers' susceptibility to uncertainty may contribute to the different results, and suggest that this susceptibility is dependent on consumers' PNS. To test the hypotheses established, an experiment was conducted. Waterless washing machine was presented as a RNP and PNS was measured by using the 12-item PNS Scale (Thompson et al. 2001). The results of the study show that for high-PNS consumers, process simulation is more effective than outcome simulation for enhancing the evaluation of a RNP, whereas for low-PNS consumers, outcome simulation is more effective than process simulation. This research contributes to the mental simulation and new product literature by suggesting and verifying that PNS moderates the effects of process versus outcome simulations for enhancing the evaluation of RNPs. This research provides important managerial implications for marketing managers of RNPs, indicating that they should take account of the target consumers' PNS in planning marketing communications. Specifically, when targeting high-PNS consumers, marketing communications that encourage process simulation may be more effective than those that encourage outcome simulation. In contrast, when targeting low-PNS consumers, marketing communications that encourage outcome simulation may be more effective than those that encourage process simulation.

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A Study on Logistics Integration and Logistics Performance of Shipping Firms in International Logistics (국제물류에서 해운기업의 물류통합과 물류성과에 관한 연구)

  • Yun, Kwang-Woon;Ha, Myung-Shin;Bae, Hee-Sung
    • THE INTERNATIONAL COMMERCE & LAW REVIEW
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    • v.26
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    • pp.143-172
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    • 2005
  • The biggest exchange of international environment of shipping logistics in 21 century should appear ultra-mega container ships on the shipping market. The competitive trend of large size container ship was based on economics of scale among the international shipping business. In the environment, shipping firms consider the integration of freight forwarder and shipper in the international logistics process. The aims of this research analyse a relation between the environment uncertainty and logistics information system(LIS) and the integration and resolve the integration and its impact on logistics performance. The research methodology of this research analyse structural equation modeling on the relation of variables. The results of research are as follows. First, Environmental uncertainty significantly influences the internal integration and the external integration. Second, LIS has an influence on the logistics integration by providing the foundation for LIS utilization in international logistics process. Third, the internal integration significantly influences a logistics performance, which implies that firms should promote interaction and collaboration through internal process integration to achieve logistics performance as the logistical cost and service. But the external integration is not significantly a logistics performance.

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