• Title/Summary/Keyword: 모델 매개변수

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Fast Bayesian Inversion of Geophysical Data (지구물리 자료의 고속 베이지안 역산)

  • Oh, Seok-Hoon;Kwon, Byung-Doo;Nam, Jae-Cheol;Kee, Duk-Kee
    • Journal of the Korean Geophysical Society
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    • v.3 no.3
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    • pp.161-174
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    • 2000
  • Bayesian inversion is a stable approach to infer the subsurface structure with the limited data from geophysical explorations. In geophysical inverse process, due to the finite and discrete characteristics of field data and modeling process, some uncertainties are inherent and therefore probabilistic approach to the geophysical inversion is required. Bayesian framework provides theoretical base for the confidency and uncertainty analysis for the inference. However, most of the Bayesian inversion require the integration process of high dimension, so massive calculations like a Monte Carlo integration is demanded to solve it. This method, though, seemed suitable to apply to the geophysical problems which have the characteristics of highly non-linearity, we are faced to meet the promptness and convenience in field process. In this study, by the Gaussian approximation for the observed data and a priori information, fast Bayesian inversion scheme is developed and applied to the model problem with electric well logging and dipole-dipole resistivity data. Each covariance matrices are induced by geostatistical method and optimization technique resulted in maximum a posteriori information. Especially a priori information is evaluated by the cross-validation technique. And the uncertainty analysis was performed to interpret the resistivity structure by simulation of a posteriori covariance matrix.

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A Pathway Analysis on Determination of Nursery Teachers' Reporting Intention for Child Abuse: Focused on Planned Behavior Theory (보육교사의 아동학대 신고의도 결정 경로 분석 -계획행동이론 중심-)

  • Kim, Ji-Woon;Kim, Yong-Duck
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.20 no.12
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    • pp.425-436
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    • 2019
  • This study constructs independent potential variables that are variables expected to affect child abuse reporting intention of child care teachers. In addition, this study establishes a research model based on the relationships between potential variables according to the results of previous studies and planning behavior theory. The purpose of this study was to examine what factors affect and how reporting intention is determined. The subjects of this study included a convenience sample of nursery teachers working in 67 daycare centers in the C region. The following results were obtained. First, the research model proposed in this study was found to be a suitable model to explain the child abuse teacher's intention to report child abuse through the analysis of the measurement and structural models. Second, the child abuse teacher's knowledge of child abuse is an important factor explaining the reporting intention and has an indirect effect through the mediation. Third, attitudes toward reporting of child care teachers were found to be the most direct factor that predicts reporting intentions. Fourth, subjective norms and reporting intentions of child care teachers were not statistically significant. Bsead on these results, basic data for improving child abuse reporting rate of childcare teachers were presented.

An Overrun Control Method and its Synthesis Method for Real-Time Systems with Probabilistic Timing Constraints (확률적인 시간 제약 조건을 갖는 실시간 시스템을 위한 과실행 제어 및 합성 기법)

  • Kim, Kang-Hee;Hwang, Ho-Young
    • Journal of KIISE:Computer Systems and Theory
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    • v.32 no.5
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    • pp.243-254
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    • 2005
  • Soft real-time applications such as multimedia feature highly variable processor requirements and probabilistic guarantees on deadline misses, meaning that each task in the application meets its deadline with a given probability. Thus, for such soft real-time applications, a system designer may want to improve the system utilization by allocating to each task a processor time less than its worst-case requirement, as long as the imposed probabilistic timing constraint is met. In this case, however, we have to address how to schedule jobs of a task that require more than (or, overrun) the allocated processor time to the task. In this paper, to address the overrun problem, we propose an overrun control method, which probabilistically controls the execution of overrunning jobs. The proposed overrun control method probabilistically allows overrunning jobs to complete for better system utilization, and also probabilistically prevents the overrunning jobs from completing so that the required probabilistic timing constraint for each task can be met. In the paper, we show that the proposed method outperforms previous methods proposed in the literature in terms of the overall deadline miss ratio, and that it is possible to synthesize the scheduling parameters of our method so that all tasks can meet the given probabilistic timing constraints.

Evaluation of the Response of BRM Analysis with Spring-Damper Absorbing Boundary Condition according to Modeling Extent of FE Region for the Nonlinear SSI Analysis (비선형 SSI 해석을 위해 Spring-Damper 에너지 흡수경계조건을 적용한 BRM의 유한요소 모델링 범위에 따른 응답평가)

  • Lee, Eun-Haeng;Kim, Jae-Min;Jung, Du-Ri;Joo, Kwang-Ho
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.29 no.6
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    • pp.499-512
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    • 2016
  • The boundary reaction method(BRM) is a substructure time domain method, it removes global iterations between frequency and time domain analyses commonly required in the hybrid approaches, so that it operates as a two-step uncoupled method. The BRM offers a two-step method as follows: (1) the calculation of boundary reaction forces in the frequency domain on an interface of linear and nonlinear regions, (2) solving the wave radiation problem subjected to the boundary reaction forces in the time domain. In the time domain analysis, the near-field soil is modeled to simulate the wave radiation problem. This paper evaluates the performance of the BRM according to modeling extent of near-field soil for the nonlinear SSI analysis of base-isolated NPP structure. For this purpose, parametric studies are performed using equivalent linear SSI problems. The accuracy of the BRM solution is evaluated by comparing the BRM solution with that of conventional SSI seismic technique. The numerical results show that the soil condition affects the modeling range of near-field soil for the BRM analysis as well as the size of the basemat. Finally, the BRM is applied for the nonlinear SSI analysis of a base-isolated NPP structure to demonstrate the accuracy and effectiveness of the method.

Seismic Traveltime Tomography in Inhomogeneous Tilted Transversely Isotropic Media (불균질 횡등방성 매질에서의 탄성파 주시토모그래피)

  • Jeong, Chang-Ho;Suh, Jung-Hee
    • Geophysics and Geophysical Exploration
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    • v.10 no.4
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    • pp.229-240
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    • 2007
  • In this study, seismic anisotropic tomography algorithm was developed for imaging the seismic velocity anisotropy of the subsurface. This algorithm includes several inversion schemes in order to make the inversion process stable and robust. First of all, the set of the inversion parameters is limited to one slowness, two ratios of slowness and one direction of the anisotropy symmetric axis. The ranges of the inversion parameters are localized by the pseudobeta transform to obtain the reasonable inversion results and the inversion constraints are controlled efficiently by ACB(Active Constraint Balancing) method. Especially, the inversion using the Fresnel volume is applied to the anisotropic tomography and it can make the anisotropic tomography more stable than ray tomography as it widens the propagation angle coverage. The algorithm of anisotropic tomography is verified through the numerical experiments. And, it is applied to the real field data measured at limestone region and the results are discussed with the drill log and geological survey data. The anisotropic tomography algorithm will be able to provide the useful tool to evaluate and understand the geological structure of the subsurface more reasonably with the anisotropic characteristics.

Software Package for Pipe Hydraulics Calculation for Single and Two Phase Flow (배관 유동의 주요 변수계산을 위한 소프트웨어 시스템의 개발)

  • Chang, Jaehun;Lee, Gunhee;Jung, Minyoung;Baek, Heumkyung;Lee, Changha;Oh, Min
    • Korean Chemical Engineering Research
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    • v.57 no.5
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    • pp.628-636
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    • 2019
  • In various industrial processes, piping serves as a link between unit processes and is an essential installation for internal flow. Therefore, the optimum design of the piping system is very important in terms of safety and cost, which requires the estimation of the pressure drop, flow rate, pipe size, etc. in the piping system. In this study, we developed a software that determines pressure drop, flow rate, and pipe size when any two of these design variables are known. We categorized the flows into single phase, homogeneous two phase, and separated two phase flows, and applied suitable calculation models accordingly. We also constructed a system library for the calculation of the pipe material, relative roughness, fluid property, and friction coefficients to minimize user input. We further created a costing library according to the piping material for the calculation of the investment cost of the pipe per unit length. We implemented all these functions in an integrated environment using a graphical user interface for user convenience, and C # programming language. Finally, we verified the accuracy of the software using literature data and examples from an industrial process with obtained deviations of 1% and 8.8% for the single phase and two-phase models.

Seismic Response Analysis of a Two-Mass Rack System Considering Frictional Behavior (마찰거동을 고려한 이중질량시스템의 지진응답해석)

  • Park, Kwan-Soon;Ok, Seung-Yong;Lee, Jeeho
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.31 no.6
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    • pp.347-352
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    • 2018
  • This study proposes seismic response analysis technique of a two-mass rack system which sustains heavy loads with frictional behavioral characteristics. In order to deal with the nonlinear frictional characteristics of the mass on the rack system, the equations of motion of the system has been derived and the appropriate numerical simulation technique has been developed. In order to examine the seismic performance of the proposed system, we consider two parameters that are expected to have great influence on the seismic performance of the system. One is the ratio of the two masses of the load and the rack structure, and the other is the friction coefficient between rack and loaded mass. A number of numerical simulations of the seismic response of structures with various natural frequencies for both parameters have been performed in order to investigate the seismic safety of the rack structures. From the simulated results. it is observed that the maximum displacement of the rack system tends to decrease drastically as the natural frequency of the structure increases regardless of the two parameters of mass ratio and friction coefficient. The proposed study provides important reference data to guarantee the seismic safety of the rack system by considering nonlinear frictional behavior of the loaded mass.

Sound Visualization based on Emotional Analysis of Musical Parameters (음악 구성요소의 감정 구조 분석에 기반 한 시각화 연구)

  • Kim, Hey-Ran;Song, Eun-Sung
    • The Journal of the Korea Contents Association
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    • v.21 no.6
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    • pp.104-112
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    • 2021
  • In this study, emotional analysis was conducted based on the basic attribute data of music and the emotional model in psychology, and the result was applied to the visualization rules in the formative arts. In the existing studies using musical parameter, there were many cases with more practical purposes to classify, search, and recommend music for people. In this study, the focus was on enabling sound data to be used as a material for creating artworks and used for aesthetic expression. In order to study the music visualization as an art form, a method that can include human emotions should be designed, which is the characteristics of the arts itself. Therefore, a well-structured basic classification of musical attributes and a classification system on emotions were provided. Also, through the shape, color, and animation of the visual elements, the visualization of the musical elements was performed by reflecting the subdivided input parameters based on emotions. This study can be used as basic data for artists who explore a field of music visualization, and the analysis method and work results for matching emotion-based music components and visualizations will be the basis for automated visualization by artificial intelligence in the future.

Exploring the Perception Change of the Consumers for the Cultural Heritage Values in the Cultural Heritage Yahaeng (문화재야행 사업에서 소비자의 문화재 가치 인식 변화 요인에 관한 연구)

  • Yim, Haksoon
    • Korean Association of Arts Management
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    • no.52
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    • pp.107-133
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    • 2019
  • This article is aimed at exploring what factors influence the perception change of the consumers for the cultural heritage values in the case of the cultural heritage policy program entitled with the cultural heritage Yahaeng. The consumers is considered as a key factor in the value creation system of the cultural heritage Yahaeng. It is necessary that the priority of the cultural heritage Yahaeng should be shifted from the supplies to the consumers. The consumer-based model of cultural heritage utilization is used as a theoretical framework. This study examines the influence of cultural heritage authenticity, cultural motivation, management system, loyalty on the perception change of the consumers for the cultural heritage values. This study is empirically examined by the means of a survey conducted on 205 visitors in the case of the Suncheon Yahaeng. The results indicate that the cultural heritage Yahaeng positively influences the perception change of the consumers for the cultural heritage values. In addition, the results indicate that cultural heritage authenticity is the most important factor which positively influences the perception change of the consumers for the cultural heritage values. In addition, the results indicate that cultural motivation positively influences on the perception change of the consumer for the cultural heritage values through the mediating variable of the loyalty. In line with its results, the article recommends that the significance based management system, evaluation system focused on the perception of the consumers for the cultural heritage should be established in the future. The article concludes that the local residents should be importantly considered as consumers and the collaborative partners in the cultural heritage Yahaeng.

AI-Based Object Recognition Research for Augmented Reality Character Implementation (증강현실 캐릭터 구현을 위한 AI기반 객체인식 연구)

  • Seok-Hwan Lee;Jung-Keum Lee;Hyun Sim
    • The Journal of the Korea institute of electronic communication sciences
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    • v.18 no.6
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    • pp.1321-1330
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    • 2023
  • This study attempts to address the problem of 3D pose estimation for multiple human objects through a single image generated during the character development process that can be used in augmented reality. In the existing top-down method, all objects in the image are first detected, and then each is reconstructed independently. The problem is that inconsistent results may occur due to overlap or depth order mismatch between the reconstructed objects. The goal of this study is to solve these problems and develop a single network that provides consistent 3D reconstruction of all humans in a scene. Integrating a human body model based on the SMPL parametric system into a top-down framework became an important choice. Through this, two types of collision loss based on distance field and loss that considers depth order were introduced. The first loss prevents overlap between reconstructed people, and the second loss adjusts the depth ordering of people to render occlusion inference and annotated instance segmentation consistently. This method allows depth information to be provided to the network without explicit 3D annotation of the image. Experimental results show that this study's methodology performs better than existing methods on standard 3D pose benchmarks, and the proposed losses enable more consistent reconstruction from natural images.