• 제목/요약/키워드: Taylor model

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A Study on Statistical Parameters for the Evaluation of Regional Air Quality Modeling Results - Focused on Fine Dust Modeling - (지역규모 대기질 모델 결과 평가를 위한 통계 검증지표 활용 - 미세먼지 모델링을 중심으로 -)

  • Kim, Cheol-Hee;Lee, Sang-Hyun;Jang, Min;Chun, Sungnam;Kang, Suji;Ko, Kwang-Kun;Lee, Jong-Jae;Lee, Hyo-Jung
    • Journal of Environmental Impact Assessment
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    • v.29 no.4
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    • pp.272-285
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    • 2020
  • We investigated statistical evaluation parameters for 3D meteorological and air quality models and selected several quantitative indicator references, and summarized the reference values of the statistical parameters for domestic air quality modeling researcher. The finally selected 9 statistical parameters are MB (Mean Bias), ME (Mean Error), MNB (Mean Normalized Bias Error), MNE (Mean Absolute Gross Error), RMSE (Root Mean Square Error), IOA (Index of Agreement), R (Correlation Coefficient), FE (Fractional Error), FB (Fractional Bias), and the associated reference values are summarized. The results showed that MB and ME have been widely used in evaluating the meteorological model output, and NMB and NME are most frequently used for air quality model results. In addition, discussed are the presentation diagrams such as Soccer Plot, Taylor diagram, and Q-Q (Quantile-Quantile) diagram. The current results from our study is expected to be effectively used as the statistical evaluation parameters suitable for situation in Korea considering various characteristics such as including the mountainous surface areas.

Spin and shape analysis for the Mars-crossing asteroid 2078 Nanking

  • Choi, Jung-Yong;Kim, Myung-Jin;Choi, Young-Jun;Yoon, Tae Seog
    • The Bulletin of The Korean Astronomical Society
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    • v.40 no.1
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    • pp.85.2-86
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    • 2015
  • The YORP effect is non-gravitational force that changes the spin-status of asteroid. So far this effect has been directly detected only from the Near-Earth asteroids (Taylor et al. 2007; Lowry et al. 2007, 2014; Breiter et al. 2011; Durech et al. 2008, 2012). Pravec at el. 2008 found the evidences for changing spin rate of small asteroids (3 - 15 km) by the YORP effect in the Main-Belt and Mars-crossing asteroids. The Mars-crossing asteroids (1.3 < q < 1.66 AU) are objects that cross orbit of the Mars. The Mars-crossing asteroids are regarded as one of the main sources for the Near-Earth asteroids. We expect that rotation of Mars-crossing asteroids would be influenced by the YORP effect. We try to search observational evidence of the YORP effect for the Mars-crossing asteroid. Our target 2078 Nanking is a population of the Mars-crossing asteroid. First light-curve of 2078 Nanking was obtained from Mohamed et al. 1994, and Warner et al. 2015 recently published new observational data. We observed this asteroid on 26th Nov. 2014 and 17th Jan. 2015 using SOAO (Sobaeksan Optical Astronomy Observatory) 0.61 m telescope with 4K CCD. Using light-curve inversion method (Kaasalainen & Torppa 2001; Kaasalainen et al. 2001), we try to determine the pole orientation and shape model of this asteroid based on the combination of our light-curve and literature photometric data. Knowing spin parameters, such as rotational period and spin axis, are essential for studying the YORP effect. In this presentation, we provide some preliminary results of our recent study: light-curve and processing of shape modeling of 2078 Nanking. We plan to find observational clue for the YORP effect on the Mars-crossing asteroids.

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Effect of Cross Rolling on the Development of Textures in Tantalum (탄탈륨 집합조직 발달에 대한 교차압연의 영향)

  • Kang, Jun-Yun;Park, Seongwon;Park, Jun Young;Park, Seong-Jun;Song, Yi-Hwa;Park, Sung-Taek;Kim, Gwang-Lyeon;Oh, Kyeong-Won
    • Journal of the Korean Society for Heat Treatment
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    • v.31 no.6
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    • pp.275-282
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    • 2018
  • Two different modes of rolling were applied to control the texture development in tantalum sheet. In the conventional uni-directional rolling, the typical rolling textures of a body-centered cubic metal which was primarily composed of <110>//(rolling direction) was developed. In a cross rolling where the specimen was rotated by $90^{\circ}$ between each pass, the rotated cube components, i.e. {100}<011> were greatly reinforced. The prediction of lattice rotation by the full-constraint Taylor model showed that the high stability and the symmetry of the rotated cube components caused their strengthening in cross-rolling. The two specimens were heated to $1,100^{\circ}C$ at $9^{\circ}C/min$and held for 1 hour for annealing, then cooled to room temperature in atmosphere. In spite of the significant difference in the deformation textures, the annealing textures were very similar. They developed strong <111>//(plane normal) components with negligible intensity at the rotated cube components, which was attributed to the negligible capability of the latter components to provide effective recrystallized grains.

Trends in Treatment with and Mechanism of Moxibustion in Cancer Patients: A Review (암 환자에 대한 구법의 치료와 메커니즘에 대한 최신 국내외 연구 현황)

  • Yoon, Hae-chang;Kang, Ji-young;Kim, Jun-young;Joung, Jin-yong;Son, Chang-gue;Lee, Nam-heon;Cho, Jung-hyo
    • The Journal of Internal Korean Medicine
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    • v.36 no.3
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    • pp.361-379
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    • 2015
  • Objectives This study aims to review and summarize existing evidence on moxibustion treatment for cancer patients. Methods Literature published until May 2015 in international journals were searched on PubMed, CAJ (CNKI-Medicine), NDSL (National discovery for science leaders), Sage Journal, ScienceDirect, Taylor&Francis Online (HSS), and Wiley Interscience (including Blackwell); and articles in Korean journals were searched on Korean Studies Information Service System (KISS), DBPIA, E-Article, KSI e-book, New article, Korea Institute of Science and Technology Information (KISTI), and Kyobo scholar. Results We analyzed 65 relevant studies. The number of studies conducted annually has increased and most are conducted in Korea and China. Moxibustion decreases the side effects of palliative treatment, thereby synergizing with anticancer treatment; it also improves the immune system, reduces tumor factors, and relieves symptoms. The mechanism of moxibustion is multi-fold: thermo, chemo, aero and kinetic. Only the kinetic effect is not significant. It also needs a complement to moxibustion because of harmful smoke. Conclusions Thus, the effect and mechanism of moxibustion in cancer patients was reviewed. There is an unmet need to develop a model of moxibustion and test it based on Korean medicine.

Quality of Life of Older Cancer Patients in Comparison with Older Chronic Disease Patients and Middle-Aged Cancer Patients (노인 암환자를 중심으로 노인 만성질환자 및 중년 암환자 간의 삶의 질과 그 영향 요인 비교)

  • Lim, Yeonok;Kim, Yojin;Yoon, Hyunsook
    • Korean Journal of Social Welfare
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    • v.65 no.4
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    • pp.367-393
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    • 2013
  • Quality of life(QoL) of older cancer patients have not gained enough attention from researchers even when cancer is the number one cause of death of Korean elderly. Therefore, this study aims at understanding the QoL of older cancer patients and factors related to it, applying Taylor(2012)'s Stress-Coping Process model, and by comparing with older chronic disease patients and middle-aged cancer patients. Results indicated that physical health QoL of older cancer patients was the worst and their mental health QoL was similar with middle aged cancer patients. Multi-group analysis of Structural Equation Modeling indicated that the relation between QoL and the stress coping resources was not statistically different from older cancer patients and older chronic disease group, as well older cancer patients and middle-aged cancer patients. Implications of results to improve the QoL of older cancer patients are discussed.

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Modeling of Size-Dependent Strengthening in Particle-Reinforced Aluminum Composites with Strain Gradient Plasticity (변형률 구배 소성을 고려한 입자 강화 알루미늄 복합재의 크기 종속 강화 모델링)

  • Suh, Yeong-Sung;Park, Moon-Shik;Song, Seung
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.35 no.7
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    • pp.745-751
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    • 2011
  • This study proposes finite element modeling of dislocation punching at cooling after consolidation in order to calculate the strength of particle-reinforced aluminum composites. The Taylor dislocation model combined with strain gradient plasticity around the reinforced particle is adopted to take into account the size-dependency of different volume fractions of the particle. The strain gradients were obtained from the equivalent plastic strain calculated during the cooling of the spherical unit cell, when the dislocation punching due to CTE (Coefficient of Thermal Expansion) mismatch is activated. The enhanced yield stress was observed by including the strain gradients, in an average sense, over the punched zone. The tensile strength of the SiCp/Al 356-T6 composite was predicted through the finite element analysis of an axisymmetric unit cell for various sizes and volume fractions of the particle. The predicted strengths were found to be in good agreement with the experimental data. Further, the particle-size dependency was clearly established.

Theoretically Informed Correlates of Hepatitis B Knowledge among Four Asian Groups: The Health Behavior Framework

  • Maxwell, Annette E.;Stewart, Susan L.;Glenn, Beth A.;Wong, Weng Kee;Yasui, Yutaka;Chang, L. Cindy;Taylor, Victoria M.;Nguyen, Tung T.;Chen, Moon S.;Bastani, Roshan
    • Asian Pacific Journal of Cancer Prevention
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    • v.13 no.4
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    • pp.1687-1692
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    • 2012
  • Background: Few studies have examined theoretically informed constructs related to hepatitis B (HBV) testing, and comparisons across studies are challenging due to lack of uniformity in constructs assessed. The present analysis examined relationships among Health Behavior Framework factors across four Asian American groups to advance the development of theory-based interventions for HBV testing in at-risk populations. Methods: Data were collected from 2007-2010 as part of baseline surveys during four intervention trials promoting HBV testing among Vietnamese-, Hmong-, Korean- and Cambodian-Americans (n = 1,735). Health Behavior Framework constructs assessed included: awareness of HBV, knowledge of transmission routes, perceived susceptibility, perceived severity, doctor recommendation, stigma of HBV infection, and perceived efficacy of testing. Within each group we assessed associations between our intermediate outcome of knowledge of HBV transmission and other constructs, to assess the concurrent validity of our model and instruments. Results: While the absolute levels for Health Behavior Framework factors varied across groups, relationships between knowledge and other factors were generally consistent. This suggests similarities rather than differences with respect to posited drivers of HBV-related behavior. Discussion: Our findings indicate that Health Behavior Framework constructs are applicable to diverse ethnic groups and provide preliminary evidence for the construct validity of the Health Behavior Framework.

Nonlinear Dynamic Analysis of Reinforced Concrete Shells Using Layered Elements with Drilling DOF (회전자유도를 갖는 층상화 요소를 이용한 철근콘크리트 쉘구조의 비선형 동적해석)

  • 김태훈;이상국;신현목
    • Journal of the Earthquake Engineering Society of Korea
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    • v.5 no.6
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    • pp.21-27
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    • 2001
  • In this paper, a nonlinear finite element procedure is presented for the dynamic analysis of reinforced concrete shells. A computer program, named RCAHEST(reinforced concrete analysis in higher evaluation system technology), for the analysis of reinforced concrete structures was used. A 4-node flat shell element will drilling rotational stiffness is used for spatial discretization. The layered approach is used to discretize behavior of concrete and reinforcement through the thickness. Material nonlinearity is taken into account by comprising tensile, compressive and shear models of cracked concrete and a model of reinforcing steel. The smeared crack approach is incorporated. Solution of the equations of motion is obtained by numerical integration using Hilber-Hughes-Taylor(HHT) algorithm. The proposed numerical method for the nonlinear dynamic analysis of reinforced concrete shells is verified by comparison with reliable analytical results.

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The State Estimation by Unknown Disturbance Observer of Underwater Vehicle System for Robust Control (강인한 제어를 위한 수중이동시스템의 상태추정에 대한 연구)

  • Lee, Jin-Woo;Kim, Hwan-Seong;An, Young-Joo
    • Journal of the Korean Society of Safety
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    • v.18 no.4
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    • pp.169-175
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    • 2003
  • In this paper, and estimation method for estimating the states of underwater vehicle systems with external unknown disturbance is proposed. First, the dynamics of underwater vehicle are induced by Taylor series expansion in the vertical plane and horizontal plane, respectively. For constructing the system model, the external efforts, i.e., the sea surface disturbances, the current, wave and etc., are regarded as external unknown disturbances. Thus the disturbance is added as external input into state-space form of underwater vehicle system. To estimate the state of systems with unknown disturbance, a disturbance observer which does not effected the external unknown input is proposed, and the existence condition for the observer is given. Finally, the effectiveness of the proposed disturbance observer for robust control of underwater vehicle systems is verified by using numerical simulation.

Sensitivity Analysis for Tank Model's Parameters by Applying Potential Evapotranspiration Equations (잠재증발산식 적용에 따른 Tank 모형 매개변수 민감도분석)

  • Rim, Chang-Soo;Lim, Ga-Hui;Lee, Won;Kim, Jung-Soo
    • Proceedings of the Korea Water Resources Association Conference
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    • 2012.05a
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    • pp.358-358
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    • 2012
  • 최근 기후변화의 영향에 따라 강수량과 증발산량이 변하는 경향을 보이고 있으며, 그에 따라 유출량도 변하고 있다. 따라서 기후변화가 수자원에 미치는 영향도 커지고 있으며, 댐 유역의 유출량 산정은 홍수나 용수의 확보측면에서 중요시 되고 있다. 탱크모형은 일본의 Sugawara가 1961년 처음 개발한 모형으로 유역을 오리피스 유출공을 가진 저류형 수조의 조합으로 가정하여 유량을 산정하는 유출모형으로 매개변수가 많고, 이들을 시행착오로 결정해야 하기 때문에 숙련된 경험이 요구되는 단점이 있으나 계산법이 명확하고 수문현상을 잘 재현한다는 장점이 있다. 탱크에는 강수량, 유출량, 그리고 증발량과 같은 입력 자료가 필요하며, 정확한 실제 증발산량 값을 알기는 어렵기 때문에 물수지를 이용해 증발산량을 계산하여 사용하고 있지만 유출량 미계측 지역에서는 사용이 어렵다. 그러므로 태양복사에너지, 온도, 바람, 기압, 습도와 같은 기상학적 인자에 따라서 잠재증발량을 산정하여 탱크 모형의 입력 자료로 사용한다면, 유출량자료가 없는 유역에서도 탱크모형을 사용하여 유출량을 산정할 수 있을 것으로 사료된다. 본 연구에서는 섬진강댐유역과 합천댐유역의 유출량 산정을 위해 잠재 증발산량 산정식(Penman, FAO P-M, Makkink, Preistley-Taylor, Hargreaves)을 적용하여 Tank 모형 매개변수들의 민감도분석을 수행하였다. 섬진강댐은 전북 임실군 강진면 옥정리와 정읍시 산내면 종성리 사이에 있으며, 유역면적은 $763km^2$, 댐 높이는 64m, 제방길이 344.2m 댐으로 매개변수 민감도 분석 적용기간은 1975년~1992년이다. 합천댐은 경상남도 합천군 대병면 회양리에 있는 댐으로 높이 96m, 길이 472m, 유역면적 $925km^2$의 다목적 댐이며, 매개변수 민감도 분석 적용기간은 1989년~1999년이다.

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