• Title/Summary/Keyword: GMF

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Deflection of Ultra-high Energy Cosmic Rays by the Galactic Magnetic Field

  • Kim, Jihyun;Kim, Hang Bae;Ryu, Dongsu
    • The Bulletin of The Korean Astronomical Society
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    • v.39 no.2
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    • pp.73.1-73.1
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    • 2014
  • We investigate the influence of the galactic magnetic field (GMF) on the arrival direction (AD) of ultra-high energy cosmic rays (UHECRs) by searching the correlation with the large-scale structure (LSS) of the universe. The deflection angle of UHECRs from sources by the GMF is reflected in a source model by introducing the Gaussian smearing angle as a free parameter. Assuming the deflections by the GMF are mainly dependent on the galactic latitude, b, we divide the regions of sky by b and analyze the correlation between the AD of UHECRs and the LSS of the universe in each region varying the smearing angle. We find the deflection is strongly dependent on the galactic latitude by the maximum likelihood estimation. Specifically, the best-fit smearing angles are $9^{\circ}$ and $84^{\circ}$ in the high galactic latitude (HGL), $-90^{\circ}$ < b < $-60^{\circ}$, and in the low galactic latitude (LGL), $-30^{\circ}$ < b < $30^{\circ}$, respectively. The strength of GMF becomes stronger from the HGL to the LGL. From the results, we can estimate the strength of GMF in each region. In the LGL, for example, if we assume UHECRs are protons, we have the order of $100{\mu}G$ GMF, which is much stronger than the expected value of conventional GMF model. However, if the primaries are heavy nuclei, which is consistent with the observational result of mass composition analysis, the order of GMF strength is a few ${\mu}G$. More data from the future experiments make it possible to study the GMF between the source of UHECRs and Earth more accurately.

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Influence of the Galactic Magnetic Field on the Distribution of Ultra-high-Energy Cosmic Rays

  • Kim, Jihyun;Kim, Hang Bae;Ryu, Dongsu
    • The Bulletin of The Korean Astronomical Society
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    • v.40 no.2
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    • pp.38.3-38.3
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    • 2015
  • Recently, the Pierre Auger Observatory (PAO), the largest ground-based project for detecting ultra-high-energy cosmic rays (UHECRs), published their 10-year data. We can access an unprecedented number of UHECR data observed by the project, which give us a possibility to get an accurate statistical test result. In this work, we investigate the influence of the galactic magnetic field (GMF) on the distribution of UHECRs by searching the correlation with the large-scale structure (LSS) of the universe. We simulate the mock UHECR events whose trajectories from the sources would be deflected by the Gaussian smearing angle which reflects the influence by the GMF. By the statistical test, we compare the correlation between the expected/observed distribution of UHECRs and the LSS of the universe in the regions of sky divided by the galactic latitude, varying the smearing angle. Here, we assume the deflections by the GMF are mainly dependent on the galactic latitude. Using the maximum likelihood estimation, we find the best-fit smearing angle in each region. If we get a trend that best-fit smearing angles differ from each region, the influence of GMF may be stronger than that of intergalactic magnetic fields (IGMF) because it is known that the distribution of IGMF follows the LSS of the universe. Also, we can estimate the strength of the GMF using the best-fit parameter by the maximum likelihood.

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UML Diagram Simulation Design based on Eclipse UML and GMF (이클립스 UML 과 GMF 기반 UML 다이어그램 시뮬레이션 프레임워크 설계)

  • Maeng, Hanmin;Shin, Youngsul;Lee, Woo Jin
    • Proceedings of the Korea Information Processing Society Conference
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    • 2007.11a
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    • pp.357-359
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    • 2007
  • 이클립스의 UML2 와 GMF 프로젝트는 UML 다이어그램 편집기를 개발하는데 있어서 기본적인 프레임워크를 지원한다. 일반적으로 UML 을 이용하여 시스템을 설계할 때에는 여러 가지의 다이어 그램을 제작하게 되는데, 이때 각 다이어그램간의 일관성을 유지시키는 것과 설계된 모델에 대한 시뮬레이션은 아주 중요한 기능요소이다. 이 논문에서는 이클립스의 UML2 와 GMF 를 기반으로 한 UML 다이어그램 시뮬레이션 프레임워크를 제안한다.

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Effects of Tropospheric Mapping Functions on GPS Data Processing

  • Won, Ji-Hye;Park, Kwan-Dong;Ha, Ji-Hyun;Cho, Jung-Ho
    • Journal of Astronomy and Space Sciences
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    • v.27 no.1
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    • pp.21-30
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    • 2010
  • In processing space geodetic data, mapping functions are used to convert the tropospheric signal delay along the zenith direction to the line of sight direction. In this study, we compared three mapping functions by evaluating their effects on the tropospheric signal delay and position estimates in GPS data processing. The three mapping functions tested are Niell Mapping Function (NMF), Vienna Mapping Function 1 (VMF1), and Global Mapping Function (GMF). The tropospheric delay and height estimates from VMF1 and GMF are compared with the ones obtained with NMF. The differences among mapping functions show annual signals with the maximum occurring in February or August. To quantitatively estimate the discrepancies among mapping functions, we calculated the maximum difference and the amplitude using a curve fitting technique. Both the maximum difference and amplitude have high correlations with the latitude of the site. Also, the smallest difference was found around $30^{\circ}N$ and the amplitudes increase toward higher latitudes. In the height estimates, the choice of mapping function did not significantly affect the vertical velocity estimate, and the precision of height estimates was improved at most of the sites when VMF1 or GMF was used instead of NMF.

A Meshfree procedure for the microscopic analysis of particle-reinforced rubber compounds

  • Wu, C.T.;Koishi, M.
    • Interaction and multiscale mechanics
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    • v.2 no.2
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    • pp.129-151
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    • 2009
  • This paper presents a meshfree procedure using a convex generalized meshfree (GMF) approximation for the large deformation analysis of particle-reinforced rubber compounds on microscopic level. The convex GMF approximation possesses the weak-Kronecker-delta property that guarantees the continuity of displacement across the material interface in the rubber compounds. The convex approximation also ensures the positive mass in the discrete system and is less sensitive to the meshfree nodal support size and integration order effects. In this study, the convex approximation is generated in the GMF method by choosing the positive and monotonic increasing basis function. In order to impose the periodic boundary condition in the unit cell method for the microscopic analysis, a singular kernel is introduced on the periodic boundary nodes in the construction of GMF approximation. The periodic boundary condition is solved by the transformation method in both explicit and implicit analyses. To simulate the interface de-bonding phenomena in the rubber compound, the cohesive interface element method is employed in corporation with meshfree method in this study. Several numerical examples are presented to demonstrate the effectiveness of the proposed numerical procedure in the large deformation analysis.

Development of the Media Art Contents Authoring Tool Using Eclipse-based GMF Technique (Eclipse기반 GMF 기법을 이용한 미디어 아트 콘텐츠 저작도구 개발)

  • Kwak, Jae-Ho;Piao, Songlin;Kim, Whoi-Yul
    • The Journal of the Korea Contents Association
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    • v.11 no.2
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    • pp.113-125
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    • 2011
  • We introduce a media art contents authoring tool called ECAS(Exhibition Contents Authoring System), and methodology employed in its development. ECAS was developed using the graphical user interface to overcome difficulties with existing authoring tools that are text-based. For efficient implementation of graphical user interface, GMF(Graphical Modeling Framework) technique by Eclipse was used. SWT(Standard Widget Toolkit) and JIT(Just-In-Time) were used to improve speed and performance of ECAS. We show convenience and efficiency of ECAS by comparing with existing media art contents authoring tools.

A Component Modeling Tool based on AUTOSAR for Automotive Software (AUTOSAR 기반 차량용 소프트웨어의 컴포넌트 모델링 도구)

  • Park, In-Su;Lee, Jung-Sun;Cho, Sung-Rae;Jung, Woo-Young;Lee, Woo-Jin
    • The KIPS Transactions:PartA
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    • v.17A no.4
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    • pp.203-212
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    • 2010
  • Recently, in automotive industry, there have been many researches related with hardware components and embedded software which controls hardware components. Since most of embedded software is tightly dependent on car manufacturers, there were some problems in reusability and interoperability of automotive software. In order to solve these problems, AUTOSAR standardized the component-based software architecture of automotive software. In AUTOSAR, several modeling diagrams should be described and their dependencies are also checked. Currently, a few company developed the prototypes of tools supporting AUTOSAR. In this paper, a component modeling tool based on AUTOSAR 3.0 is developed for enhancing the usability of existing tools using Eclipse GMF. The tool is composed of a graphical component modeling tool and a graphical network topology tool. Since these tools are generated based on GMF without hard coding, it is relatively easy to customize the tools for adopting company‘s needs and easy to follow the improvement of the standard and development environments.

Deep Neural Network-Based Beauty Product Recommender (심층신경망 기반의 뷰티제품 추천시스템)

  • Song, Hee Seok
    • Journal of Information Technology Applications and Management
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    • v.26 no.6
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    • pp.89-101
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    • 2019
  • Many researchers have been focused on designing beauty product recommendation system for a long time because of increased need of customers for personalized and customized recommendation in beauty product domain. In addition, as the application of the deep neural network technique becomes active recently, various collaborative filtering techniques based on the deep neural network have been introduced. In this context, this study proposes a deep neural network model suitable for beauty product recommendation by applying Neural Collaborative Filtering and Generalized Matrix Factorization (NCF + GMF) to beauty product recommendation. This study also provides an implementation of web API system to commercialize the proposed recommendation model. The overall performance of the NCF + GMF model was the best when the beauty product recommendation problem was defined as the estimation rating score problem and the binary classification problem. The NCF + GMF model showed also high performance in the top N recommendation.

Simulating Rotation Measure toward High Galactic Latitude

  • Akahori, Takuya;Ryu, Dong-Su;Kim, Jong-Soo;Gaensler, Bryan
    • The Bulletin of The Korean Astronomical Society
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    • v.36 no.2
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    • pp.116.2-116.2
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    • 2011
  • We investigate Faraday rotation measure (RM) toward high Galactic latitudes due to the Galactic magnetic field (GMF). The Galactic contribution to RM comes from the global component and the turbulent component of the GMF, and we newly model the latter by incorporating data of MHD turbulence simulations. We find that for the turbulent velocity of ~50 km/s, the standard deviation of the RM due to the GMF toward high Galactic latitudes is close to the observed value, several rad m^{-2}. Yet, the predicted second-order structure function (SF) has values substantially smaller than the observed ones at separation angles of <~ several degree. This suggests that the intergalactic magnetic field (IGMF) significantly contributes to RM toward high Galactic latitudes, particularly at small angular scales. Our work proposes a strategy for surveys to explore the IGMF with LOFAR, ASKAP, MeerKAT, and SKA.

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Development of AUTOSAR Conformance Test Architecture Modeling Tool using Eclipse GMF (Eclipse GMF를 이용한 AUTOSAR 적합성 테스트 아키텍처 설계 도구 개발)

  • Cho, Na-Yun;Kyung, Min-Gi;Min, Dug-Ki
    • Proceedings of the Korean Information Science Society Conference
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    • 2010.06b
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    • pp.337-340
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    • 2010
  • 최근 개발하는 소프트웨어의 복잡도 증가로 소프트웨어 및 전체 시스템에 대한 테스팅 기술의 중요성이 커지고 있는 추세에 맞춰 임베디드 소프트웨어에 대한 테스팅 기술의 활발한 연구가 진행되고 있다. 임베디드 소프트웨어 테스트는 개발하는 소프트웨어의 결함 발견을 통해 그 기능과 품질에서 더욱 완전한 소프트웨어 개발을 할 수 있다는 장점을 가지고 현재 차량전장용 표준 플랫폼인 AUTOSAR(AUTomotive Open System ARchitecture) 소프트웨어의 표준 준수여부를 테스트하는 AUTOSAR 적합성 테스트에 적용되고 있다. 본 논문에서는 AUTOSAR 적합성 테스트 프로세스 중 디자인 단계의 테스트 아키텍처를 Eclipse GMF에 기반을 둔 설계 도구 개발을 소개한다. 본 논문의 AUTOSAR 적합성 테스트를 위한 테스트 아키텍처 설계 도구를 통해 설계된 테스트 시스템 결과물의 재사용성을 제공할 것이라 예상한다.

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