• Title/Summary/Keyword: system uncertainty

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A Study on the Comparison Between China's Anti-Dumping System and WTO Agreement (중국 반덤핑 법규와 WTO 규범과의 적합성 비교 연구)

  • Shin, Sung-Shik;Choi, Hae-Bum
    • International Commerce and Information Review
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    • v.13 no.4
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    • pp.323-349
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    • 2011
  • As China is one of WTO member nations, It has an obligation to have to certainly keep a standard regarding anti-dumping systems deciding in WTO agreements. Nonetheless the Chinese anti-dumping laws is causing legal uncertainty because of insufficient details regulations about the account of dumping margins, the termination of an investigation in case of negligible imports, and sunset review And a part of regulations are disagreed with WTO anti-dumping agreement about price undertakings. Therefore, South Korea should indicate them and urge the Chinese government to revise them so that its anti-dumping Law is agreed with WTO agreement. Aside from this, if the anti-dumping investigation is initiated, South Korea government must observe how the Chinese authorities operates its anti-dumping law that do not agree with WTO agreement, and should prepare the countermeasure accordingly. The analysis of this study is concentrated on the compatibility of the WTO anti-dumping agreement with China's interpretation of the antidumping policy and public law. Also, Including our export company, government agencies, academic circles being related, and international trade advisory agencies must expand opportunity of information sharing.

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A Comparison Study of Model Parameter Estimation Methods for Prognostics (건전성 예측을 위한 모델변수 추정방법의 비교)

  • An, Dawn;Kim, Nam Ho;Choi, Joo Ho
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.25 no.4
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    • pp.355-362
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    • 2012
  • Remaining useful life(RUL) prediction of a system is important in the prognostics field since it is directly linked with safety and maintenance scheduling. In the physics-based prognostics, accurately estimated model parameters can predict the remaining useful life exactly. It, however, is not a simple task to estimate the model parameters because most real system have multivariate model parameters, also they are correlated each other. This paper presents representative methods to estimate model parameters in the physics-based prognostics and discusses the difference between three methods; the particle filter method(PF), the overall Bayesian method(OBM), and the sequential Bayesian method(SBM). The three methods are based on the same theoretical background, the Bayesian estimation technique, but the methods are distinguished from each other in the sampling methods or uncertainty analysis process. Therefore, a simple physical model as an easy task and the Paris model for crack growth problem are used to discuss the difference between the three methods, and the performance of each method evaluated by using established prognostics metrics is compared.

Distributed GIS-Based Watershed Rainfall-Runoff Model Development and Its Calibration using Weather Radar (기상레이더와 지형정보시스템을 이용한 분포형 강우-유출 유역모형의 개발과 검정)

  • Skahill, Brian E.;Choi, Woo-Hee;Kim, Min-Hwan;Kim, Sung-Kyun;Johnson, Lynn E.
    • Journal of Korea Water Resources Association
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    • v.36 no.2
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    • pp.285-300
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    • 2003
  • An event-based, kinematic, infiltration-excess, and distributed rainfall-runoff model using weather radar and Geographic Information System(GIS) was developed to acknowledge and account lot the spatial variability and uncertainty of several parameters relevant to storm surface runoff and surface flow The developed model is compatible with raster GIS and spatially and temporally varied rainfall data. To calibrate the model, Monte Carlo simulation and a likelihood measure are utilized; allowing for a range of possible system responses from the calibrated model. Using rain gauge adjusted radar-rainfall estimates, the developed model was applied and evaluated to a limited number of historical events for the Ralston Creek and Goldsmith Gulch basins within the Denver Urban Drainage and Flood Control District (UDFCD) that contain mixed land use classifications. While based on a limited number of Monte Carlo simulations and considered flood events, Nash and Sutcliffe efficiency score ranges of -0.19∼0.95 / -0.75∼0.81 were obtained from the calibrated models for the Ralston Creek and Goldsmith Gulch basins, based on a comparison of observed and simulated hydrographs. For the Ralston Creek and Goldsmith Gulch basins, Nash and Sutcliffe efficiency scores of 0.88/0.10, 0.14/0.71, and 0.99/0.95 for runoff volume, peak discharge, and time to peak, respectively, were obtained from the model.

Some Thoughts on Direction to Cope with the Sea level Rise in Korea (우리나라 해수면 상승 대응방향에 관한 소고)

  • Cho, Kwang-Woo;Maeng, Jun-Ho
    • Journal of the Korean Society for Marine Environment & Energy
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    • v.10 no.4
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    • pp.227-234
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    • 2007
  • The present study attempts to provide basic directions to respond to sea-level rise effectively based on the status of sea-level rise and its impact. The impact of the sea-level rise will be one of the most adverse component among climate change due to global warming. The basic approach to deal with sea level rise requires both mitigation and adaptation. Though the emission reduction can reduce a portion of sea level rise, the rising trend cannot be avoided due to the difficulty of the emission reduction and a strong inertia of the ocean. Therefore an effective corresponding direction has to focus on the development of appropriate adaptation strategies. Because sea level rise problem has scientific uncertainty, the corresponding system has to be designed to deal with the processes of information and awareness, planning and design, implementation, and monitoring and evaluation in continuous and long-term process. The future task to correspond effectively to the issue in Korea includes the improvement of scientific information, the development of adaptative measures, the enhancement of people awareness, the consensus of corresponding necessity, and formation of integrated corresponding system.

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Development of the Korean Film Industry and Its Spatial Characteristics: Gangnam Region of Seoul as A New Cluster in A New Renaissance? (한국 영화산업의 발전과 공간적 집적 특성: 새로운 부흥의 중심지로서 서울 강남지역의 등장 ?)

  • Choo Sung-Jae
    • Journal of the Korean Geographical Society
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    • v.41 no.3 s.114
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    • pp.245-266
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    • 2006
  • This study aims to explain the emergence of Gangnam Region of Seoul as a new cluster of the Korean film industry in the context of its history of growth, recent development characteristics, and its production system. Statistical analyses of Korean industries and in-depth interview surveys to film producers were conducted. The results of the analyses show that there has been obvious tendency of film makers' move from Chungmuro, a traditional cluster of the Korean film industry, to Gangnam and many births of new film makers in Gangnam. This new cluster, however, is operating on informal networking between film makers and related personnel, not on formalized production system composed of specialized functions and labor market. Therefore, it can be called as loosely-articulated cluster. This form of cluster has much to do with production milieu of Gangnam, such as advantages of obtaining information and consumer trend, diverse atmosphere which makes it easier to meet diverse people, favorable environment to embed creativity and fresh idea, etc. This trend of the film industry to orient a specific area can be explained in conjunction with the uniqueness of the film industry, such as uncertainty, project-based work, generation gap between film makers, participation of large companies or increasing size of investment.

Parameter Decision of Muskingum Channel Routing Method Based on the Linear System Assumption (선형시스템가정에 근거한 Muskingum 하도추적방법의 매개변수 결정)

  • Yoo, Chulsang;Sin, Jiye;Jun, Chang Hyun
    • Journal of Korea Water Resources Association
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    • v.46 no.5
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    • pp.449-463
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    • 2013
  • This study proposes the method for determining the Muskingum channel routing model parameters based on the assumption of linear system. The proposed method was applied to the Chungju dam basin for the evaluation. Additionally, the rainfall-runoff was repeated for the Yeongchun-Chungju dam reach using seven rainfall events observed. Summarizing the results is as follows. First, the concentration time and storage coefficient of a channel reach formed by the subdivision can be expressed as the difference between the concentration times and storage coefficients of upstream and downstream basins. The storage coefficients of the channel reach estimated is equal to the storage coefficient of the Muskingum channel routing model and the weight factor can be simply estimated using the ratio between the concentration time and storage coefficient. Second, the weight factor of the Muskingum model is in inverse proportion to the Russel coefficient, which is in between 0.4166 and 0.625 when considering the Russel coefficients generally applied. Finally the application to the Yeongchun-Chungju dam reach showed that the proposed method is still valid regardless of the limitations such as the uncertainty of the observed data.

Balancing Water Supply Reliability, Flood Hazard Mitigation and Environmental Resilience in Large River Systems

  • Goodwin, Peter
    • Proceedings of the Korea Water Resources Association Conference
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    • 2016.05a
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    • pp.1-1
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    • 2016
  • Many of the world's large ecosystems are severely stressed due to population growth, water quality and quantity problems, vulnerability to flood and drought, and the loss of native species and cultural resources. Consequences of climate change further increase uncertainties about the future. These major societal challenges must be addressed through innovations in governance, policy, and ways of implementing management strategies. Science and engineering play a critical role in helping define possible alternative futures that could be achieved and the possible consequences to economic development, quality of life, and sustainability of ecosystem services. Science has advanced rapidly during the past decade with the emergence of science communities coalescing around 'Grand Challenges' and the maturation of how these communities function has resulted in large interdisciplinary research networks. An example is the River Experiment Center of KICT that engages researchers from throughout Korea and the world. This trend has been complemented by major advances in sensor technologies and data synthesis to accelerate knowledge discovery. These factors combine to allow scientific debate to occur in a more open and transparent manner. The availability of information and improved communication of scientific and engineering issues is raising the level of dialogue at the science-policy interface. However, severe challenges persist since scientific discovery does not occur on the same timeframe as management actions, policy decisions or at the pace sometimes expected by elected officials. Common challenges include the need to make decisions in the face of considerable uncertainty, ensuring research results are actionable and preventing science being used by special interests to delay or obsfucate decisions. These challenges are explored in the context of examples from the United States, including the California Bay-Delta system. California transfers water from the wetter northern part of the state to the drier southern part of the state through the Central Valley Project since 1940 and this was supplemented by the State Water Project in 1973. The scale of these activities is remarkable: approximately two thirds of the population of Californians rely on water from the Delta, these waters also irrigate up to 45% of the fruits & vegetables produced in the US, and about 80% of California's commercial fishery species live in or migrate through the Bay-Delta. This Delta region is a global hotspot for biodiversity that provides habitat for over 700 species, but is also a hotspot for the loss of biodiversity with more than 25 species currently listed by the Endangered Species Act. Understanding the decline of the fragile ecosystem of the Bay-Delta system and the potential consequences to economic growth if water transfers are reduced for the environment, the California State Legislature passed landmark legislation in 2009 (CA Water Code SS 85054) that established "Coequal goals of providing a more reliable water supply for California and protecting, restoring, and enhancing the Delta ecosystem". The legislation also stated that "The coequal goals shall be achieved in a manner that protects and enhances the unique cultural, recreational, natural resource, and agricultural values of the Delta as an evolving place." The challenges of integrating policy, management and scientific research will be described through this and other international examples.

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Model-Based Design and Enhancement of Operational Procedure for Guided Missile Flight Test System (유도무기 비행시험 시스템을 위한 모델 기반 운용절차의 설계 및 개선)

  • Park, Woong;Lee, Jae-Chon
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.20 no.4
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    • pp.479-488
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    • 2019
  • The flight test operational procedure artifact includes mission planning, execution methods, and safety measures for each step of test progress. As the development of guided missiles has become more advanced and strategic, flight test has become increasingly complex and broadened. Therefore, increased reliability of the flight test operation procedures was required to ensure test safety. Particularly, the design of the flight test operational procedures required verification through M&S to predict and prepare for the uncertainty in a new test. The relevant studies have published the optimal framework development for flight tests and the model-based improvements of flight test processes, but they lacked the specificity to be applied directly to the flight test operational procedures. In addition, the flight test operational procedures, which consist of document bases, have caused problems such as limitations of analysis capabilities, insensitive expressions, and lack of scalability for the behavior and performance analysis of test resources. To improve these problems, this paper proposes how to design operational procedure of guided missile flight test system by applying MBSE(Model-based Systems Engineering). This research has improved reliability by increasing the ability to analyze the behavior and performance of test resources, and increased efficiency with the scalability applicable to multiple flight tests. That can be also used continuously for the guided missile flight tests that will be developed in the future.

A Comparison of Pan-sharpening Algorithms for GK-2A Satellite Imagery (천리안위성 2A호 위성영상을 위한 영상융합기법의 비교평가)

  • Lee, Soobong;Choi, Jaewan
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.40 no.4
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    • pp.275-292
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    • 2022
  • In order to detect climate changes using satellite imagery, the GCOS (Global Climate Observing System) defines requirements such as spatio-temporal resolution, stability by the time change, and uncertainty. Due to limitation of GK-2A sensor performance, the level-2 products can not satisfy the requirement, especially for spatial resolution. In this paper, we found the optimal pan-sharpening algorithm for GK-2A products. The six pan-sharpening methods included in CS (Component Substitution), MRA (Multi-Resolution Analysis), VO (Variational Optimization), and DL (Deep Learning) were used. In the case of DL, the synthesis property based method was used to generate training dataset. The process of synthesis property is that pan-sharpening model is applied with Pan (Panchromatic) and MS (Multispectral) images with reduced spatial resolution, and fused image is compared with the original MS image. In the synthesis property based method, fused image with desire level for user can be produced only when the geometric characteristics between the PAN with reduced spatial resolution and MS image are similar. However, since the dissimilarity exists, RD (Random Down-sampling) was additionally used as a way to minimize it. Among the pan-sharpening methods, PSGAN was applied with RD (PSGAN_RD). The fused images are qualitatively and quantitatively validated with consistency property and the synthesis property. As validation result, the GSA algorithm performs well in the evaluation index representing spatial characteristics. In the case of spectral characteristics, the PSGAN_RD has the best accuracy with the original MS image. Therefore, in consideration of spatial and spectral characteristics of fused image, we found that PSGAN_RD is suitable for GK-2A products.

Rock Mechanics Site Characterization for HLW Disposal Facilities (고준위방사성폐기물 처분시설 부지에 대한 암반역학 부지특성화)

  • Um, Jeong-Gi;Hyun, Seung Gyu
    • Economic and Environmental Geology
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    • v.55 no.1
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    • pp.1-17
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    • 2022
  • The mechanical and thermal properties of the rock masses can affect the performance associated with both the isolating and retarding capacities of radioactive materials within the deep geological disposal system for High-Level Radioactive Waste (HLW). In this study, the essential parameters for the site descriptive model (SDM) related to the rock mechanics and thermal properties of the HLW disposal facilities site were reviewed, and the technical background was explored through the cases of the preceding site descriptive models developed by SKB (Swedish Nuclear and Fuel Management Company), Sweden and Posiva, Finland. SKB and Posiva studied parameters essential for the investigation and evaluation of mechanical and thermal properties, and derived a rock mechanics site descriptive model for safety evaluation and construction of the HLW disposal facilities. The rock mechanics SDM includes the results obtained from investigation and evaluation of the strength and deformability of intact rocks, fractures, and fractured rock masses, as well as the geometry of large-scaled deformation zones, the small-scaled fracture network system, thermal properties of rocks, and the in situ stress distribution of the disposal site. In addition, the site descriptive model should provide the sensitivity analysis results for the input parameters, and present the results obtained from evaluation of uncertainty.