• Title/Summary/Keyword: Feature-based Modeling

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Regional Realtime Ocean Tide and Storm-surge Simulation for the South China Sea (남중국해 지역 실시간 해양 조석 및 폭풍해일 시뮬레이션)

  • Kim, Kyeong Ok;Choi, Byung Ho;Lee, Han Soo;Yuk, Jin-Hee
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.30 no.2
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    • pp.69-83
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    • 2018
  • The South China Sea (SCS) is a typical marginal sea characterized with the deep basin, shelf break, shallow shelf, many straits, and complex bathymetry. This study investigated the tidal characteristics and propagation, and reproduced typhoon-induced storm surge in this region using the regional real-time tide-surge model, which was based on the unstructured grid, resolving in detail the region of interest and forced by tide at the open boundary and by wind and air pressure at the surface. Typhoon Haiyan, which occurred in 2013 and caused great damage in the Philippines, was chosen as a case study to simulate typhoon's impact. Amplitudes and phases of four major constituents were reproduced reasonably in general, and the tidal distributions of four constituents were similar to the previous studies. The modelled tide seemed to be within the acceptable levels, considering it was difficult to reproduce the tide in this region based on the previous studies. The free oscillation experiment results described well the feature of tide that the diurnal tide is prevailing in the SCS. The tidal residual current and total energy dissipation were discussed to understand the tidal and sedimentary environments. The storm-surge caused by typhoon Haiyan was reasonably simulated using this modeling system. This study established the regional real-time barotropic tide/water level prediction system for the South China Sea including the seas around the Philippines through the validation of the model and the understanding of tidal characteristics.

Analyzing the Effect of Characteristics of Dictionary on the Accuracy of Document Classifiers (용어 사전의 특성이 문서 분류 정확도에 미치는 영향 연구)

  • Jung, Haegang;Kim, Namgyu
    • Management & Information Systems Review
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    • v.37 no.4
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    • pp.41-62
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    • 2018
  • As the volume of unstructured data increases through various social media, Internet news articles, and blogs, the importance of text analysis and the studies are increasing. Since text analysis is mostly performed on a specific domain or topic, the importance of constructing and applying a domain-specific dictionary has been increased. The quality of dictionary has a direct impact on the results of the unstructured data analysis and it is much more important since it present a perspective of analysis. In the literature, most studies on text analysis has emphasized the importance of dictionaries to acquire clean and high quality results. However, unfortunately, a rigorous verification of the effects of dictionaries has not been studied, even if it is already known as the most essential factor of text analysis. In this paper, we generate three dictionaries in various ways from 39,800 news articles and analyze and verify the effect each dictionary on the accuracy of document classification by defining the concept of Intrinsic Rate. 1) A batch construction method which is building a dictionary based on the frequency of terms in the entire documents 2) A method of extracting the terms by category and integrating the terms 3) A method of extracting the features according to each category and integrating them. We compared accuracy of three artificial neural network-based document classifiers to evaluate the quality of dictionaries. As a result of the experiment, the accuracy tend to increase when the "Intrinsic Rate" is high and we found the possibility to improve accuracy of document classification by increasing the intrinsic rate of the dictionary.

Improvement of crossflow model of MULTID component in MARS-KS with inter-channel mixing model for enhancing analysis performance in rod bundle

  • Yunseok Lee;Taewan Kim
    • Nuclear Engineering and Technology
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    • v.55 no.12
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    • pp.4357-4366
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    • 2023
  • MARS-KS, a domestic regulatory confirmatory code of Republic of Korea, had been developed by integrating RELAP5/MOD2 and COBRA-TF. The integration of COBRA-TF allowed to extend the capability of MARS-KS, limited to one-dimensional analysis, to multi-dimensional analysis. The use of COBRA-TF was mainly focused on subchannel analyses for simulating multi-dimensional behavior within the reactor core. However, this feature has been remained as a legacy without ongoing maintenance. Meanwhile, MARS-KS also includes its own multidimensional component, namely MULTID, which is also feasible to simulate three-dimensional convection and diffusion. The MULTID is capable of modeling the turbulent diffusion using simple mixing length model. The implementation of the turbulent mixing is of importance for analyzing the reactor core where a disturbing cross-sectional structure of rod bundle makes the flow perturbation and corresponding mixing stronger. In addition, the presence of this turbulent behavior allows the secondary transports with net mass exchange between subchannels. However, a series of assessments performed in previous studies revealed that the turbulence model of the MULTID could not simulate the aforementioned effective mixing occurred in the subchannel-scale problems. This is obvious consequence since the physical models of the MULTID neglect the effect of mass transport and thereby, it cannot model the void drift effect and resulting phasic distribution within a bundle. Thus, in this study, the turbulence mixing model of the MULTID has been improved by means of the inter-channel mixing model, widely utilized in subchannel analysis, in order to extend the application of the MULTID to small-scale problems. A series of assessments has been performed against rod bundle experiments, namely GE 3X3 and PSBT, to evaluate the performance of the introduced mixing model. The assessment results revealed that the application of the inter-channel mixing model allowed to enhance the prediction of the MULTID in subchannel scale problems. In addition, it was indicated that the code could not predict appropriate phasic distribution in the rod bundle without the model. Considering that the proper prediction of the phasic distribution is important when considering pin-based and/or assembly-based expressions of the reactor core, the results of this study clearly indicate that the inter-channel mixing model is required for analyzing the rod bundle, appropriately.

Origin and Evolution of Leucogranite of NE Yeongnam Massif from Samcheok Area, Korea (삼척지역 북동 영남 육괴에 분포하는 우백질 화강암의 기원 및 진화)

  • Cheong, Won-Seok;Na, Ki-Chang
    • The Journal of the Petrological Society of Korea
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    • v.17 no.1
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    • pp.16-35
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    • 2008
  • We study metamorphism of metasedimetary rocks and origin and evolution of leucogranite form Samcheok area, northeastern Yeongnam massif, South Korea. Metamorphic rocks in this area are composed of metasedimentary migmatite, biotite granitic gneiss and leucogranite. Metasedimentary rocks, which refer to major element feature of siliclastic sediment, are divided into two metamorphic zones based on mineral assemblages, garnet and sillimanite zones. According to petrogenetic grid of mineral assemblages, metamorhpic P-T conditions are $740{\sim}800^{\circ}C$ at $4.8{\sim}5.8\;kbar$ in the garnet zone and $640-760^{\circ}C$ at 2.5-4.5kbar in sillimanite zone. The leucogranite (Imwon leucogranite) is peraluminous granite which has high alumina index (A/CNK=1.31-1.93) and positive discriminant factor value (DF > 0). Thus, leucogranite is S-type granite generated from metasedimentary rocks. Major and trace element diagram ($R_1-R_2$ diagram and Rb vs. Y+Nb etc.) show collisional environment such as syn-collisional or volcanic arc granite. Because Rb/sr ratio (1.8-22.9) of leucogranites is higher than Sr/Ba ratio (0.21-0.79), leucogranite would be derived from muscovite dehydrate melting in metasedimentary rocks. Leucogranites have lower concentration of LREE and Eu and similar that of HREE relative to metasedimentary rocks. To examine difference of REEs between leucogranites and metasedimentary rocks, we perform modeling using volume percentage of a leucogranite and a metasedimenatry rock from study area and REE data of minerals from rhyolite (Nash and Crecraft, 1985) and melanosome of migmatite (Bea et al., 1994). Resultants of modeling indicate that LREE and HREE are controlled by monazites and garnet, respectively, although zircon is estimated HREE dominant in some leucogranite without garnet. Because there are many inclusions of accessary phases such as monazite and zircon in biotites from metasedimentary rocks. leucogranitic magma was mainly derived from muscovite-breakdown in metasedimenary rocks. Leucogranites can be subdivided into two types in compliance with Eu anomaly of chondrite nomalized REE pattern; the one of negative Eu anomaly is type I and the other is type II. Leucogranites have lower Eu concetnrations than that of metasedimenary rocks and similar that of both type. REE modeling suggest that this difference of Eu value is due to that of components of feldspars in both leucogranite and metasedimentary rock. The tendency of major ($K_2O$ and $Na_2O$) and face elements (Eu, Rb, Sr and Ba) of leucogranites also indicate that source magma of these two types was developed by anatexis experienced strong fractionation of alkali-feldspar. Conclusionally, leucogranites in this area are products of melts which was generated by muscovite-breakdown of metasedimenary rock in environment of continetal collision during high temperature/pressure metamorphism and then was fractionated and crystallized after extraction from source rock.

A Study on the 3D Measurement Data Application: The Detailed Restoration Modeling of Mireuksajiseoktap (미륵사지석탑 정밀복원모형 제작을 중심으로 한 3차원 실측데이터의 활용 연구)

  • Moon, Seang Hyen
    • Korean Journal of Heritage: History & Science
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    • v.44 no.2
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    • pp.76-95
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    • 2011
  • After dismantled, Mireuksajiseoktap(Stone pagoda of Mireuksa Templesite) is being in the stage of restoration design. Now, different ways - producing restoration model, a 3 dimension simulation - have been requested to make more detailed and clearer restoration design prior to confirmation of its restoration design and actual restoration carry-out. This thesis proposes the way to build the detailed model for better restoration plan using extensively-used Reverse Engineering technique and Rapid Prototyping. It also introduces each stage such as a 3-dimension actual measurement, building database, a 3-dimension simulation etc., to build a desirable model. On the top of that, this thesis reveals that after dismantled, MIruksaji stone pagoda's interior and exterior were not constructed into pieces but wholeness, so that its looks can be grasped in more virtually and clearly. Secondly, this thesis makes a 3-dimension study on the 2-dimension design possible by acquiring basic materials about a 3-dimension design. Thirdly, the individual feature of each member like the change of member location can be comprehended, considering comparing analysis and joint condition of member. Lastly, in the structural perspective this thesis can be used as reference materials for structure reinforcement design by grasping destructed aspects of stone pagoda and weak points of the structure. In dismantlement-repair and restoration work of cultural properties that require delicate attention and exactness, there may be evitable errors on time and space in building reinforcement and restoration design based on a 2-dimension plan. Especially, the more complicate and bigger the subject is, the more difficult an analysis about the status quo and its delicate design are. A series of pre-review, based on the 3-dimension data according to actual measurement, can be one of the effective way to minimize the possibility that errors about time - space happen by building more delicate plan and resolving difficulties.

Performance Evaluation of Workstation System within ATM Integrated Service Switching System using Mean Value Analysis Algorithm (MVA 알고리즘을 이용한 ATM 기반 통합 서비스 교환기 내 워크스테이션의 성능 평가)

  • Jang, Seung-Ju;Kim, Gil-Yong;Lee, Jae-Hum;Park, Ho-Jin
    • Journal of KIISE:Computing Practices and Letters
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    • v.6 no.4
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    • pp.421-429
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    • 2000
  • In present, ATM integrated switching system has been developed to a mixed modules that complexed switching system including maintenance, operation based on B-ISDN/LAN service and plug-in module, , which runs on workstation computer system. Meanwhile, workstation has HMI operation system feature including file system management, time management, graphic processing, TMN agent function. The workstation has communicated with between ATM switching module and clients. This computer system architecture has much burden messages communication among processes or processor. These messages communication consume system resources which are socket, message queue, IO device files, regular files, and so on. Therefore, in this paper we proposed new performance modeling with this system architecture. We will analyze the system bottleneck and improve system performance. In addition, in the future, the system has many additional features should be migrated to workstation system, we need previously to evaluate system bottleneck and redesign it. In performance model, we use queueing network model and the simulation package is used PDQ and C-program.

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Aesthetic Characteristics of Hanae Mori's Apparel (하나에 모리(Hanae Mori) 의상에 나타난 미적 특성)

  • Choi, Young-Ok
    • Fashion & Textile Research Journal
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    • v.9 no.6
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    • pp.613-625
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    • 2007
  • Globalizing the Japanese fashion successfully, Hanae Mori's work awoke the western fashion world's nostalgia towards the East. Analyzing the aesthetic characteristics of Hanae Mori's clothes what kinds of aesthetic characteristic that her work had and what kinds of influences that she made in the modern fashion would provide substantial contribution of the world's modern fashion. This study provided forms and remarkable features of Japanese traditional custom, revealed Hanae Mori's life and her philosophies of fashion, and defined Hanae Mori's aesthetic characteristics by analyzing her work from 1970's until the retirement, July 2004. Methods of this study are completed by documentary records of Hanae Mori, research papers and fashion magazines that are published domestically and internationally, and collected materials from internet. The results of analysis are epitomized as below. Hanae Mori was the first Japanese fashion designer who expressed the characteristics of traditional Japanese custom with modernity sprit. In the 60's and 70's, especially in the U.S. and European fashion market, she inspired western fashion designers by her original sprit of art: combining Japanese tradition which showed distinctive color and spirit of nature and the western beauty. Hanae Mori created new dress molding from the Kimono's unstructured feature. Her layered look dressing, oblique adjustment and Obi, and others all enabled Mori to express Japanese image into modern fashion. Additionally, in terms of traditional Japanese image being acknowledged world-widely, she played a major contribution in world fashion by suggesting a new vision and raised several sensations in fashion artistry and modeling. Amongst her various patterns, Hanae Mori had butterfly patterns in most of her works, which was her representative symbol. This spoke for her strong will and senses of duty that wanting to inform beauty of Japanese women who were reflected in modern and graceful butterfly patterns. Flowers were another element that symbolized Mori. Using various flower motifs that bloomed in every different four seasons, she connected two images into her fashion; beauty of the nature and enlightening image of vibrating life. The aesthetic characteristics of Hanae Mori's clothes were defined as five: Japonism, naturalism, feminism, eroticism, and modernism. Japonism which is the spirit of Japanese, Mori used the concept to connect the East and the West. Naturalism represented harmony of the nature and the human. Feminism highlighted Eastern women's beauty. Eroticism emitted feminine attraction. Modernism represented simplicity and sophistication. Such aesthetic character illustrated Mori's original emotion that was based on Japanese spirit and she combined it with values of the East and the West. From the analysis of Mori's aesthetic characteristics, it is clearly recognizable her feministic beauty is emanated by her original emotion and sensibility.

Light-Ontology Classification for Efficient Object Detection using a Hierarchical Tree Structure (효과적인 객체 검출을 위한 계층적 트리 구조를 이용한 조명 온톨로지 분류)

  • Kang, Sung-Kwan;Lee, Jung-Hyun
    • Journal of Digital Convergence
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    • v.10 no.10
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    • pp.215-220
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    • 2012
  • This paper proposes a ontology of tree structure approach for adaptive object recognition in a situation-variant environment. In this paper, we introduce a new concept, ontology of tree structure ontology, for context sensitivity, as we found that many developed systems work in a context-invariant environment. Due to the effects of illumination on a supreme obstinate designing context-sensitive recognition system, we have focused on designing such a context-variant system using ontology of tree structure. Ontology can be defined as an explicit specification of conceptualization of a domain typically captured in an abstract model of how people think about things in the domain. People produce ontologies to understand and explain underlying principles and environmental factors. In this research, we have proposed context ontology, context modeling, context adaptation, and context categorization to design ontology of tree structure based on illumination criteria. After selecting the proper light-ontology domain, we benefit from selecting a set of actions that produces better performance on that domain. We have carried out extensive experiments on these concepts in the area of object recognition in a dynamic changing environment, and we have achieved enormous success, which will enable us to proceed on our basic concepts.

RBM-based distributed representation of language (RBM을 이용한 언어의 분산 표상화)

  • You, Heejo;Nam, Kichun;Nam, Hosung
    • Korean Journal of Cognitive Science
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    • v.28 no.2
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    • pp.111-131
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    • 2017
  • The connectionist model is one approach to studying language processing from a computational perspective. And building a representation in the connectionist model study is just as important as making the structure of the model in that it determines the level of learning and performance of the model. The connectionist model has been constructed in two different ways: localist representation and distributed representation. However, the localist representation used in the previous studies had limitations in that the unit of the output layer having a rare target activation value is inactivated, and the past distributed representation has the limitation of difficulty in confirming the result by the opacity of the displayed information. This has been a limitation of the overall connection model study. In this paper, we present a new method to induce distributed representation with local representation using abstraction of information, which is a feature of restricted Boltzmann machine, with respect to the limitation of such representation of the past. As a result, our proposed method effectively solves the problem of conventional representation by using the method of information compression and inverse transformation of distributed representation into local representation.

An experimental study on the smoke-spread region before reaching the critical velocity for the case of fires in tunnels employing longitudinal ventilation system (종류식 환기 시스템에서 임계속도 도달 전 스모크 확산 영역에 관한 실험적 연구)

  • Ki, Young-Min;Yoon, Sung-Wook;Yoon, Chan-Hoon;Kim, Jin
    • Tunnel and Underground Space
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    • v.16 no.6 s.65
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    • pp.526-535
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    • 2006
  • An experimental study was carried out on a reduced scale tunnel model to grasp the behavioral feature of fire-induced smoke in the long tunnels. Based on Froude modeling, the 1/50 scaled tunnel model (20 m long) was constructed by acrylic tubes and paraffin gas was released inside the tunnel to simulate the 20 MW fire-induced smoke. me test results show, that after approximately 2 minutes of fire generation, was descended from the tunnel ceiling through the decrease of buoyancy, then it was symmetrically propagated about 90 meters for 4 minutes before jet fans were operated. The smoke was effectively controlled when the jet fans were operated and an air stream velocity was getting closed to reach a critical velocity (the minimum air velocity that requires to suppress the smoke spreading against the longitudinal ventilation flow during the tunnel fire situations). It was also found out that a range of smoke was spreaded about 3 meters from the origin of fire but the range was not propagated to the escape direction anymore. The early stage of the In operation, however, showed that the smoke was hardly controlled. It means that the operation of emergency ventilation system has many dangerous factors such as an intercepting breathing zone.