• Title/Summary/Keyword: formalism

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Current Calculation Simulation Model for Smartgrid-based Energy Distribution System Operation (스마트 그리드 기반 에너지 시스템 운영을 위한 배전계통 조류계산 시뮬레이션 모델 개발)

  • Bae, HeeSun;Shin, Seungjae;Moon, Il-Chul;Bae, Jang Won
    • Journal of the Korea Society for Simulation
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    • v.30 no.1
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    • pp.113-126
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    • 2021
  • The future energy consumption pattern will show a very different pattern from the present due to the increase of distributed power sources such as renewable energy and the birth of the concept of prosumers, etc. Accordingly, it can be predicted that the direction of establishment of an appropriate production and supply plan considering the stability and consumption efficiency of the entire power grid will also be different from now. This paper proposes a simulation model that can test a new operational strategy when faced with a number of possible future environments. Through the proposed model, it is possible to simulate and analyze power consumed and supplied in a future Smart Grid environment, in which a large amount of new concepts including energy storage service (ESS) and distributed energy resources (DER) will be added. In particular, it is possible to model complex systems structurally by using DEVS formalism among the ABM (Agent-Based Model) methodologies that can model decision-making for each agent existing in the grid, and several factors can be easily added to the grid. The simulation model was verified using given dataset in the current situation, and scenario analysis was performed by simply adding an ESS, one of the main elements of the smart grid, to the model.

A Study on Floral Art Exhibition Applying Storytelling (스토리텔링을 적용한 화예전시에 관한 연구)

  • Ahn, Hyun Jung
    • Journal of the Korean Society of Floral Art and Design
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    • no.43
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    • pp.19-37
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    • 2020
  • The purpose of this paper is to seek for a new exhibition form of floral art design that deviates from formalism by suggesting a planning exhibition with storytelling away from the unilinear exhibition composition method of floral art design currently being held in Korea. Storytelling in flower art exhibition is to construct an easy-to-understand exhibition through the use of the four-step construction method of introduction-development-turn-conclusion, or the three-step construction method of intro-body-conclusion. It is intended to efficiently propose interaction between creators and viewers. In order to seek for diversification of floral art design, it is necessary to secure a convergent view that has been blowing since the Millennial, collaborate with other fields, or attempt exhibition planning that reflects storytelling. The main function of the exhibition is to meet and communicate directly with the public. This study intends to propose the exhibition structure and implementation direction of floral art exhibition through the case of 'Hwawanggye' held at the Sungkyunkwan University Museum in 2017, focusing on the exhibition where storytelling is applied. Through this study, it is expected that the discourse in the field of floral art will be expanded, and various networks of aesthetic suggestions and floral art design with storytelling will be boosted.

Modeling and Simulation for Effectiveness Analysis of Anti-Ballistic Warfare in Naval Vessels (함정의 대탄도탄전 효과도 분석을 위한 모델링 및 시뮬레이션)

  • Jang Won Bae;GuenHo Lee ;Hyungho Na ;Il-Chul Moon
    • Journal of the Korea Society for Simulation
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    • v.32 no.3
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    • pp.55-66
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    • 2023
  • In recent years, naval vessels have been developed to fulfill a variety of missions by being equipped with various cutting-edge equipment and ICT technologies. One of the main missions of Korean naval vessels is anti-ballistic missile warfare to defend key units and areas against the growing threat of ballistic missiles. Because the process of detection and interception is too complex and the cost of failure is much high, a lot of preparation is required to effectively conduct anti-ballistic missile warfare. This paper describes the development of a simulation model of anti-ballistic missile warfare with combat systems and equipment to be installed on future naval vessels. In particular, the DEVS formalism providing a modular and hierarchical modeling manner was applied to the simulation model, which can be utilized to efficiently represent various anti-ballistic missile warfare situations. In the simulation results presented, experiments were conducted to analyze the effectiveness of the model for effective detection resource management in anti-ballistic missile warfare. This study is expected to be utilized as a variety of analysis tools necessary to determine the optimal deployment and configuration of combat resources and operational tactics required for effective anti-ballistic missile warfare of ships in the future.

Evaluation of Factors Used in AAPM TG-43 Formalism Using Segmented Sources Integration Method and Monte Carlo Simulation: Implementation of microSelectron HDR Ir-192 Source (미소선원 적분법과 몬테칼로 방법을 이용한 AAPM TG-43 선량계산 인자 평가: microSelectron HDR Ir-192 선원에 대한 적용)

  • Ahn, Woo-Sang;Jang, Won-Woo;Park, Sung-Ho;Jung, Sang-Hoon;Cho, Woon-Kap;Kim, Young-Seok;Ahn, Seung-Do
    • Progress in Medical Physics
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    • v.22 no.4
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    • pp.190-197
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    • 2011
  • Currently, the dose distribution calculation used by commercial treatment planning systems (TPSs) for high-dose rate (HDR) brachytherapy is derived from point and line source approximation method recommended by AAPM Task Group 43 (TG-43). However, the study of Monte Carlo (MC) simulation is required in order to assess the accuracy of dose calculation around three-dimensional Ir-192 source. In this study, geometry factor was calculated using segmented sources integration method by dividing microSelectron HDR Ir-192 source into smaller parts. The Monte Carlo code (MCNPX 2.5.0) was used to calculate the dose rate $\dot{D}(r,\theta)$ at a point ($r,\theta$) away from a HDR Ir-192 source in spherical water phantom with 30 cm diameter. Finally, anisotropy function and radial dose function were calculated from obtained results. The obtained geometry factor was compared with that calculated from line source approximation. Similarly, obtained anisotropy function and radial dose function were compared with those derived from MCPT results by Williamson. The geometry factor calculated from segmented sources integration method and line source approximation was within 0.2% for $r{\geq}0.5$ cm and 1.33% for r=0.1 cm, respectively. The relative-root mean square error (R-RMSE) of anisotropy function obtained by this study and Williamson was 2.33% for r=0.25 cm and within 1% for r>0.5 cm, respectively. The R-RMSE of radial dose function was 0.46% at radial distance from 0.1 to 14.0 cm. The geometry factor acquired from segmented sources integration method and line source approximation was in good agreement for $r{\geq}0.1$ cm. However, application of segmented sources integration method seems to be valid, since this method using three-dimensional Ir-192 source provides more realistic geometry factor. The anisotropy function and radial dose function estimated from MCNPX in this study and MCPT by Williamson are in good agreement within uncertainty of Monte Carlo codes except at radial distance of r=0.25 cm. It is expected that Monte Carlo code used in this study could be applied to other sources utilized for brachytherapy.

Independent Verification Program for High-Dose-Rate Brachytherapy Treatment Plans (고선량률 근접치료계획의 정도보증 프로그램)

  • Han Youngyih;Chu Sung Sil;Huh Seung Jae;Suh Chang-Ok
    • Radiation Oncology Journal
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    • v.21 no.3
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    • pp.238-244
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    • 2003
  • Purpose: The Planning of High-Dose-Rate (HDR) brachytherapy treatments are becoming individualized and more dependent on the treatment planning system. Therefore, computer software has been developed to perform independent point dose calculations with the integration of an isodose distribution curve display into the patient anatomy images. Meterials and Methods: As primary input data, the program takes patients'planning data including the source dwell positions, dwell times and the doses at reference points, computed by an HDR treatment planning system (TPS). Dosimetric calculations were peformed in a $10\times12\times10\;Cm^3$ grid space using the Interstitial Collaborative Working Group (ICWG) formalism and an anisotropy table for the HDR Iridium-192 source. The computed doses at the reference points were automatically compared with the relevant results of the TPS. The MR and simulation film images were then imported and the isodose distributions on the axial, sagittal and coronal planes intersecting the point selected by a user were superimposed on the imported images and then displayed. The accuracy of the software was tested in three benchmark plans peformed by Gamma-Med 12i TPS (MDS Nordion, Germany). Nine patients'plans generated by Plato (Nucletron Corporation, The Netherlands) were verified by the developed software. Results: The absolute doses computed by the developed software agreed with the commercial TPS results within an accuracy of $2.8\%$ in the benchmark plans. The isodose distribution plots showed excellent agreements with the exception of the tip legion of the source's longitudinal axis where a slight deviation was observed. In clinical plans, the secondary dose calculations had, on average, about a $3.4\%$ deviation from the TPS plans. Conclusion: The accurate validation of complicate treatment plans is possible with the developed software and the qualify of the HDR treatment plan can be improved with the isodose display integrated into the patient anatomy information.

Dose Verification Study of Brachytherapy Plans Using Monte Carlo Methods and CT Images (CT 영상 및 몬테칼로 계산에 기반한 근접 방사선치료계획의 선량분포 평가 방법 연구)

  • Cheong, Kwang-Ho;Lee, Me-Yeon;Kang, Sei-Kwon;Bae, Hoon-Sik;Park, So-Ah;Kim, Kyoung-Joo;Hwang, Tae-Jin;Oh, Do-Hoon
    • Progress in Medical Physics
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    • v.21 no.3
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    • pp.253-260
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    • 2010
  • Most brachytherapy treatment planning systems employ a dosimetry formalism based on the AAPM TG-43 report which does not appropriately consider tissue heterogeneity. In this study we aimed to set up a simple Monte Carlo-based intracavitary high-dose-rate brachytherapy (IC-HDRB) plan verification platform, focusing particularly on the robustness of the direct Monte Carlo dose calculation using material and density information derived from CT images. CT images of slab phantoms and a uterine cervical cancer patient were used for brachytherapy plans based on the Plato (Nucletron, Netherlands) brachytherapy planning system. Monte Carlo simulations were implemented using the parameters from the Plato system and compared with the EBT film dosimetry and conventional dose computations. EGSnrc based DOSXYZnrc code was used for Monte Carlo simulations. Each $^{192}Ir$ source of the afterloader was approximately modeled as a parallel-piped shape inside the converted CT data set whose voxel size was $2{\times}2{\times}2\;mm^3$. Bracytherapy dose calculations based on the TG-43 showed good agreement with the Monte Carlo results in a homogeneous media whose density was close to water, but there were significant errors in high-density materials. For a patient case, A and B point dose differences were less than 3%, while the mean dose discrepancy was as much as 5%. Conventional dose computation methods might underdose the targets by not accounting for the effects of high-density materials. The proposed platform was shown to be feasible and to have good dose calculation accuracy. One should be careful when confirming the plan using a conventional brachytherapy dose computation method, and moreover, an independent dose verification system as developed in this study might be helpful.

Quantitative Analysis of Magnetization Transfer by Phase Sensitive Method in Knee Disorder (무릎 이상에 대한 자화전이 위상감각에 의한 정량분석법)

  • Yoon, Moon-Hyun;Sung, Mi-Sook;Yin, Chang-Sik;Lee, Heung-Kyu;Choe, Bo-Young
    • Investigative Magnetic Resonance Imaging
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    • v.10 no.2
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    • pp.98-107
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    • 2006
  • Magnetization Transfer (MT) imaging generates contrast dependent on the phenomenon of magnetization exchange between free water proton and restricted proton in macromolecules. In biological materials in knee, MT or cross-relaxation is commonly modeled using two spin pools identified by their different T2 relaxation times. Two models for cross-relaxation emphasize the role of proton chemical exchange between protons of water and exchangeable protons on macromolecules, as well as through dipole-dipole interaction between the water and macromolecule protons. The most essential tool in medical image manipulation is the ability to adjust the contrast and intensity. Thus, it is desirable to adjust the contrast and intensity of an image interactively in the real time. The proton density (PD) and T2-weighted SE MR images allow the depiction of knee structures and can demonstrate defects and gross morphologic changes. The PD- and T2-weighted images also show the cartilage internal pathology due to the more intermediate signal of the knee joint in these sequences. Suppression of fat extends the dynamic range of tissue contrast, removes chemical shift artifacts, and decreases motion-related ghost artifacts. Like fat saturation, phase sensitive methods are also based on the difference in precession frequencies of water and fat. In this study, phase sensitive methods look at the phase difference that is accumulated in time as a result of Larmor frequency differences rather than using this difference directly. Although how MT work was given with clinical evidence that leads to quantitative model for MT in tissues, the mathematical formalism used to describe the MT effect applies to explaining to evaluate knee disorder, such as anterior cruciate ligament (ACL) tear and meniscal tear. Calculation of the effect of the effect of the MT saturation is given in the magnetization transfer ratio (MTR) which is a quantitative measure of the relative decrease in signal intensity due to the MT pulse.

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The Development of Air-kerma Strength Calculation Algorithm in Terms of the Absorbed Dose to Water for HDR Ir-192 Source (기준점에서의 물 흡수선량을 이용한 Ir-192 선원의 공기커마 세기 계산을 위한 알고리즘 개발)

  • Huh, Hyun-Do;Kim, Woo-Chul;Loh, John-Jk;Lee, Suk;Lee, Sang-Hoon;Cho, Sam-Ju;Shin, Dong-Oh;Choi, Jin-Ho;Kwon, Soo-Il;Kim, Seong-Hoon
    • Progress in Medical Physics
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    • v.17 no.4
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    • pp.232-237
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    • 2006
  • The aim of this study was to develop the calculation algorithm of source strength of Ir-192 source In terms of the absorbed dose to water instead of an apparent activity (Ci). For this work the Multi Purpose Brachytherapy Phantom(MPBP) was developed, which was designed to locate the source and the chamber precisely at a specific position Inside the water phantom. The reference point of measurement was set at the 5 cm distance along the transverse axis of the source. For a brachytherapy source calibration, the absorbed dose to water calibration factor ($N_{D.W.Q}$) of an lonization chamber were determined and then apply standard protocols of absorbed dose to water. The calibration factor ($N_{D.W.Q}$) of the ion chamber (TM30013, PTW, Germany) was determined using the EGSnrcCPP Monte Carlo Code. The calculated calibration factor ($N_{D.W.Q}$) was 5.28 cGy/nC. The calculated factor was then used to determine the absorbed dose to water from which the air kerma strength for an Ir-192 source can be easily derived at the reference point (5 cm). The calculated air kerma strength showed discrepancies of -0.6% to +1.8% relative to the air kerma strength provided by the vendor, In this work we demonstrated that the air kerma strength ($S_k$) could be determined from the absorbed dose to water calibration factor for Ir-192 source. In audition, this source calibration method could be applied directly to the dose Calculation formalism of AAPM report TG-43.

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Closed Integral Form Expansion for the Highly Efficient Analysis of Fiber Raman Amplifier (라만증폭기의 효율적인 성능분석을 위한 라만방정식의 적분형 전개와 수치해석 알고리즘)

  • Choi, Lark-Kwon;Park, Jae-Hyoung;Kim, Pil-Han;Park, Jong-Han;Park, Nam-Kyoo
    • Korean Journal of Optics and Photonics
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    • v.16 no.3
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    • pp.182-190
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    • 2005
  • The fiber Raman amplifier(FRA) is a distinctly advantageous technology. Due to its wider, flexible gain bandwidth, and intrinsically lower noise characteristics, FRA has become an indispensable technology of today. Various FRA modeling methods, with different levels of convergence speed and accuracy, have been proposed in order to gain valuable insights for the FRA dynamics and optimum design before real implementation. Still, all these approaches share the common platform of coupled ordinary differential equations(ODE) for the Raman equation set that must be solved along the long length of fiber propagation axis. The ODE platform has classically set the bar for achievable convergence speed, resulting exhaustive calculation efforts. In this work, we propose an alternative, highly efficient framework for FRA analysis. In treating the Raman gain as the perturbation factor in an adiabatic process, we achieved implementation of the algorithm by deriving a recursive relation for the integrals of power inside fiber with the effective length and by constructing a matrix formalism for the solution of the given FRA problem. Finally, by adiabatically turning on the Raman process in the fiber as increasing the order of iterations, the FRA solution can be obtained along the iteration axis for the whole length of fiber rather than along the fiber propagation axis, enabling faster convergence speed, at the equivalent accuracy achievable with the methods based on coupled ODEs. Performance comparison in all co-, counter-, bi-directionally pumped multi-channel FRA shows more than 102 times faster with the convergence speed of the Average power method at the same level of accuracy(relative deviation < 0.03dB).

Quest of Wang Yak-heo(王若虚)'s Theories of Poetry - With a focus on Three Volumes of 「Talks on Chinses Poetry」 among "the Collected Writings of Wang Yak-heo"(滹南遺老集) (王若虚的詩論探究(왕약허의 시론 탐구) - 以《滹南遺老集》中的《詩話》三卷爲主(『호남유로집』 중 「시화」 3권을 중심으로) -)

  • Jang, Yung-Ki
    • (The)Study of the Eastern Classic
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    • no.34
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    • pp.207-224
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    • 2009
  • This research is a quest of theories of poetry of Wang Yak-heo who was a literary critic during Chin(金) dynasty in ancient China. Wang Yak-heo left a fine piece of work, dubbed ${\ll}$Honam Yuro Jib${\gg}$ and, in this paper, the author closely reviewed the theories of poetry that is appeared, especially, in the three volumes of ${\ll}$Talks on Chinese Poetry${\gg}$ among the collections of Wang's poetry criticism. In particular, the author investigated the positive and negative aspects of Honam's commentaries on the works by Chinese poets, including his principles of poetics, creative skills, and practical criticism, etc. Wang Yak-heo has not been known much in the history of Chinese literary thoughts, however, his theory of criticism, especially, among the talks on Chinese the works by Chinese poets, his literature criticisms establish unique and distinctive point of views. Wang Yak-heo's poetics, more than anything else, valued nature, meanings, truth, and contents therein. He exhibited realistic view of literature. Meanwhile, he analyzed the methods of expression by Du Bo(杜甫, pronounced, "Du Fu" in Chinese), So Sik, also known as So Dong Pa (蘇軾, Su Shi or 蘇東坡, Su Dong Po in Chinese), and Hwang Jeong-gyeon(黃庭堅, Huang T'ing-chien), and highly evaluated the realistic poems written by Du Bo, Baek Geo-I (白居易, pronounced, "Bai Juyi" in Chinese), and So Sik. Also, he opposed to formalism or externality, however, he never made light of formality of poetry. In his comments on the works by Chinese poets, he highly evaluated the poems sung by So Sik and Beek Geo-I, in the mean time, however, he criticized their works without hesitation. Having set up his own unique criteria for critique, Wang didn't accept other opinions in a seemingly illogical manner, and he presented what he thoughts and other different points of view from others. Specifically, he attached great importance to whether or not modification of words and phrases, grammar, and whole context were congruent to one another and had been well harmonized. However, in his poetics, Wang was so wrapped himself in reasonableness or rationality, he analyzed each and every word in great detailed manner, as the result, he sometimes didn't read the sentiment or mood that the writers intended to express through poems. He excessively restricted himself to the words and phrases, so that he was not able to realize natural emotions and joy of imagination that were presented in the poems, and, in the end, this brought about adverse effects to the poet's thought.