• Title/Summary/Keyword: M&S

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Flow Analysis indoor Coal Storage Shed due to Wind Velocity and Wind Direction of Ambient Air (외기의 풍속 및 풍향에 따른 옥내저탄장 내부 유동 해석)

  • Kim, Tae-Kwon;Cho, Mok-Lyang;Bae, Young-Wan;Kim, Ji-Won
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.21 no.1
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    • pp.538-545
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    • 2020
  • The outdoor coal storage sheds of thermal power plants are being converted to indoor coal storage sheds worldwide because of the environmental pollution problems in the surrounding areas. On the other hand, indoor coal storage sheds are causing problems, such as indoor coal scattering and harmful gas generation. In this study, the ventilation method of indoor coal storage sheds was analyzed in terms of the internal flow characteristics and ventilation according to the outside wind velocity and direction. CFD analysis was performed based on the actual flow measurement information inside the indoor coal storage sheds. A comparison of the wind speed of 6 m/s and 2 m/s when the outside wind direction was easterly showed that the stream velocity to the monitor louver was faster and the recirculation area was clearer at 6 m/s than at 2 m/s. In addition, the trend of a westerly wind was similar to that of the easterly wind. The ventilation rate according to the wind speed was 13.1 times and 4.4 times for a wind speed of 6 m/s and 2 m/s, respectively. If the wind speed is 2 m/s, the situation does not meet the required number of ventilations per hour in a general plant, and needs to be improved.

Changes in Salinity, Hydraulic Conductivity and Penetration Resistance of a Silt Loam Soil in a Reclaimed Tidal Land (미사질 양토인 간척지 토양에서의 염류도와 수리전도도 및 관입 저항의 변화)

  • Jung, Yeong-Sang;Yoo, Sun-Ho;An, Yeol;Joo, Jin-Ho;Yu, Il-Ho
    • Korean Journal of Soil Science and Fertilizer
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    • v.35 no.4
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    • pp.207-215
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    • 2002
  • Changes in salinity, hydraulic conductivity and penetration resistance in a reclaimed tidal land reclaimed in 1986 were studied. The salinity monitoring based on electrical conductivity of saturated extract, ECe, was conducted from 1994, when the land use for experimental crop production started after tile drainage. The site was abandoned since 1999. The hydraulic conductivity was measured by a sand fill auger hole method, and the resistance was measured with a dynamic penetrometer in situ. The averaged ECe in 1994 was $33.7dS\;m^{-1}$ ranging from 25.5 to $44.8dS\;m^{-1}$, and was decreased to $25.7dS\;m^{-1}$ with large range from 0.8 to $70.3dS\;m^{-1}$ before experiment was $1.89{\times}10^{-7}m\;s^{-1}$. It increased to $1.32{\times}10^6m\;s^{-1}$ in the top 20-cm soil with large variability, while it showed $3.44{\times}10^7m\;s^{-1}$ beneath the 20-cm soil depth with less variability. The penetration resistance of the soil ranged from 0.05 to 9.99MPa. The vertical distribution of penetration resistance indicated the hardened layer was developed at the depth of 20~40 cm where the hydraulic conductivity was sharply decreased.

A Study on the V&V Process of M&S for the Test and Evaluation (시험평가용 M&S에 대한 V&V 프로세스 연구)

  • Park, Ju-Hye
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.20 no.9
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    • pp.397-404
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    • 2019
  • When developing a weapon system, a T&E(Test and Evaluation) can be performed using M&S for the test items that cannot be evaluated in the real world. In this case, the VV&A activities are required to prove the credibility of M&S for the T&E. Recently, the use of M&S has been increasing as the R&D trends of weapon systems are becoming more advanced. Therefore, the VV&A activities are also increasing. The VV&A activities aim to verify, validate, and accredit that the simulation can represent a real system and ensure credibility regarding its purpose and intention of use. VV&A activities are divided into V&V and Accreditation. When performing VV&A in the ADD (Agency for Defense Development), the V&V activities are performed by a separate department of the ADD and the accreditation activities are performed in the DTAQ (Defense Agency for Technology and Quality). This paper proposes a V&V process for a T&E of M&S that has been performed in ADD. The process is used to verify and validate the documents and data generated during the development process according to the accreditation criteria, and provides objective data that can be used to judge whether the accreditation decision and acceptance criteria are met.

Co-Infection with Cytomegalovirus and Helicobacter pylori in a Child with $M\acute{e}n\acute{e}$trier's Disease

  • Yoo, Yangho;Lee, Yoon;Lee, Yoo Min;Choe, Yon Ho
    • Pediatric Gastroenterology, Hepatology & Nutrition
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    • v.16 no.2
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    • pp.123-126
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    • 2013
  • $M\acute{e}n\acute{e}$trier's disease is a rare protein-losing gastropathy characterized by hypertrophic gastric fold, foveolar hyperplasia, and hypoproteinemia with resulting peripheral edema. It is clinically evident as nonspecific gastrointestinal symptoms, including abdominal discomfort, nausea and vomiting, abdominal pain, weight loss, diarrhea, and edema. Pediatric $M\acute{e}n\acute{e}$trier's disease usually has an insidious onset and progressive, chronic clinical course and it spontaneously resolves in weeks or months. The pathogenesis of $M\acute{e}n\acute{e}$trier's disease is not clearly understood. $M\acute{e}n\acute{e}$trier's disease is thought to be associated with some gastric infections. But the cause of $M\acute{e}n\acute{e}$trier's disease is unknown, an association with cytomegalovirus (CMV) and Helicobacter pylori has been suggested. In Korea, We present the first a case of pediatric $M\acute{e}n\acute{e}$trier's disease with positive evidence of CMV and H. pylori.

M&S PlugIn-Based Architecture Framework Development (M&S PlugIn-Based Architecture Framework 개발)

  • Won, Garng-Yun;Choi, Sang-Yeong
    • Journal of KIISE:Computer Systems and Theory
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    • v.36 no.2
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    • pp.53-59
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    • 2009
  • Simulation Based Acquisition(SBA) which pursues to use M&S in manner of integrated collaboration is being applied in defense acquisition. To accomplish SBA efficiently, reusability, reconfiguration and scalability of M&S components are important factors. To avoid constraints caused by coupling of components, PBA is designed to add and configure components easily by enabling independent interface and interaction among the components and provides common development infrastructure also. And PBA framework is implemented to support the development of a simulator which uses the PBA. It is expected that deployment of PBA framework as common development infrastructure can raise efficiency of M&S works.

A Study on the Deformation and Perforation Problem for Steel Plates Subjected to High-Speed Collision and Superhigh-Speed Collision (고속충돌 및 초고속충돌 강판구조물의 대변형 관통문제에 관한 연구)

  • 원석희;이경언;고재용;이계희;이제명;백점기;이성로
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • 2004.04a
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    • pp.95-99
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    • 2004
  • This paper describe inner-collision-characteristics of the ship structural plates when the projectile collides with plate-material using LS-DYNA3D which is general and useful finite element analysis tool in collision problem fields. The series analyses were carried out from high speed(41.56m/s-118.9m/s) to ultrahigh speed(544.05m/s-800m/s). Through these analyses we can approach empirical formula to estimate penetration limit of the ship structural plates with which the projectile of various speed collides.

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A Study of the Chemical Components of the Halophyte Suaeda asparagoides $M_{IQ}$ (염생식물 나문재(Suaeda asparagoides $M_{IQ}$)의 이화학적 성분 조성)

  • Lee, Young-Keun;Lee, Yoon-Shin;Jung, Eun-Kyung
    • Journal of the East Asian Society of Dietary Life
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    • v.20 no.3
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    • pp.452-457
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    • 2010
  • To obtain basic information on the utilization of Suaeda (S.) asparagoides $M_{IQ}$ as a raw material in food, it's chemical components of were investigated. S. asparagoides $M_{IQ}$ from the Hwaseong-si in Korea was used after drying and grinding with powder. The total dietary fiber, insoluble dietary fiber and soluble dietary fiber contents of S. asparagoides $M_{IQ}$ were found to be 39.41%, 37.63% and 1.78%, respectively. Macromineral components of S. asparagoides $M_{IQ}$ were Na (7.6%), K (2.4%) and Mg (0.6%). High contents of microminerals such as Cu, Mn and Zn were also found. Lysine and methionine which are essential amino acids were detected with the value of 215 mg/100 g and 23.2 mg/100 g, respectively. S. asparagoides $M_{IQ}$ that was harvested in May was higher in crude protein than that harvested in September but the crude fat content of that which was harvested in September was twice as high as that harvested in May.

The Study on CGF Behavior Modeling Methodologies for Defense M&S: Focusing on Survey and Future Direction (국방 M&S의 가상군 행위 모델링 방법론 연구: 조사와 미래방향을 중심으로)

  • Cho, Namsuk;Moon, Hoseok;Pyun, Jai Jeong
    • Journal of the Korea Society for Simulation
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    • v.29 no.2
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    • pp.35-47
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    • 2020
  • Immediate and serious attention on CGF(computer generated forces) behavior modeling for defense M&S (modeling & simulation) is required in response to the reduction in the number of troops and development of 4th industrial technologies. It is crucial for both military person and engineer to understand such technologies. The research aims to provide guidelines for establishment of research direction on CGF behavior modeling. We investigate traditional and/or novel methodologies such as rule-based, agent-based, and learning-based method. Discussions on future direction of applicable area and strategies are followed. We expect that the research plays a key role for understanding CGF behavior modeling.

The Formation of Rope- and Pebbles-Type Aggregation from the Micro-End-to-End and -Side-by-Side Aggregates in Poly(L-proline) Solutions

  • 김현돈
    • Bulletin of the Korean Chemical Society
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    • v.18 no.9
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    • pp.929-933
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    • 1997
  • Morphological studies in the micro-end-to-end (m-E-E) and micro-side-by-side (m-S-S) aggregations were conducted by using of scanning electron microscope (SEM) for the samples precipitated by heating of the end-products of the transition of FormⅡ (left-handed helix, three peptides per turn, 31) Form Ⅰ (right-handed helix, 3.3 peptides per turn, 103) in poly(L-proline) (PLP) in acetic acid(water)-propanol (1:9 v/v) solvent. The observed morphology for the solide state shows a rope (or super helical) type and pebbles type aggregate for the (m-E-E) and (m-S-S) aggregate respectively. The viscosities were also measured during the heat-precipitation in order to elucidate the process of formation of the rope- and pebbles-type aggregates. The result for the (m-E-E) aggregations exhibit two steps, i.e., at first, the viscosity increases with time (step 1), thereafter it decrease until attain the last value (step 2). But the (m-S-S) aggregations show only one step in the decreases in viscosity. On the bases of all experimental results it is possible to propose a reasonable mechanism for the formation of the two types of aggregates of the (m-E-E) and (m-S-S).

A Study on the Comparison of the Vibration Data in Cast Resin Transformer According to the Load Type (부하 형태에 따른 몰드변압기에서의 진동데이터 비교에 관한 연구)

  • Shong, Kil-Mok;Choi, Myung-Il;Kim, Young-Seog;Bang, Sun-Bae;Kim, Chong-Min
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.26 no.4
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    • pp.75-81
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    • 2012
  • In this study, vibration characteristics in according to the load type of cast resin transformer using vibration measurement device were compared. Measurement conditions are the same installation and operation of the three-phase cast resin transformer. If the load increases in transformer using the rotating machinery, the frequency is growing. In the transformer using the lighting and heating loads, it's detected the 55 [${\mu}m/s$] in or outside and 120 [${\mu}m/s$] or more at 60[Hz], the 30 [${\mu}m/s$] in or outside at 120[Hz], and the 70 [${\mu}m/s$] in or outside at 420[Hz]. When increases the loads, it's appeared the 60 [${\mu}m/s$] or less at 450[Hz] or more in rotating machinery, but the velocity of lighting and lighting loads are appeared from 5[${\mu}m/s$] to 115[${\mu}m/s$] inside the 420[Hz] in the same load condition of 20[%]. Through this study, it's verified that there are differences the internal vibration in according to the type of load in cast resin transformer.