• 제목/요약/키워드: R-square

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2/2 트윌 직물의 크림프와 곡률(I) -Square cloth의 변형 모델링에 의한 이론적 고찰- (Crimp and Curvature in the 2/2 Twill Fabrics(I) -Theoretical Considerations for the Modified Square Cloth Models-)

  • 이춘길;박진석
    • 한국의류산업학회지
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    • 제1권4호
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    • pp.387-392
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    • 1999
  • The effects of the ratio of warp diameter to filling diameter (${\beta}$-ratio) and warp thread crash on the crimp factor and the yarn curvature were studied theoretically in this paper. The models of 2/2 twill fabric derived square cloth and sinusoidal curved cloth were used for the theoretical analysis. The crimp factors (C) for the models were given theoretically as follows; (1) Derived square cloth(general equation for b) $$C=\frac{(1+{\beta})({\theta}-sin{\theta})}{(1+{\beta})sin{\theta}+{\alpha}}$$ (2) Sihusoidal curved cloth $$C=\frac{(1+{\beta})sin{\theta}\[1+\{\frac{{\pi}(1-cos{\theta})}{4sin{\theta}}\}^2\]+{\alpha}}{(1+{\beta})sin{\theta}+{\alpha}}-1$$ The curvatures(${\kappa}$) for the models were given theoretically as follows; (1) Derived square cloth $${\kappa}=\frac{2}{d_w+d_f}$$ (2) Sinusoidal curved cloth $${\kappa}=\|{^{\;\;\prime\prime} \atop r}(s)\| \\ where \;s=\frac{p^'}{{\pi}}\(u+\frac{k^2u}{4}+\frac{k^2}{8}sin2u\)$$.

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Buckling analysis of nanocomposite cut out plate using domain decomposition method and orthogonal polynomials

  • Jamali, M.;Shojaee, T.;Kolahchi, R.;Mohammadi, B.
    • Steel and Composite Structures
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    • 제22권3호
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    • pp.691-712
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    • 2016
  • In this editorial, buckling analytical investigation of the nanocomposite plate with square cut out reinforced by carbon nanotubes (CNTs) surrounded by Pasternak foundation is considered. The plate is presumed has square cut out in center and resting on Pasternak foundation. CNTs are used as amplifier in plate for diverse distribution, such as uniform distribution (UD) and three patterns of functionally graded (FG) distribution types of CNTs (FG-X, FG-A and FG-O). Moreover, the effective mechanical properties of nanocomposite plate are calculated from the rule of mixture. Domain decomposition method and orthogonal polynomials are applied in order to define the shape function of nanocomposite plate with square cut out. Finally, Rayleigh-Ritz energy method is used to obtain critical buckling load of system. A detailed parametric study is conducted to explicit the effects of the dimensions of plate, length of square cut out, different distribution of CNTs, elastic medium and volume fraction of CNTs. It is found from results that increase the dimensions of plate and length of square cut out have negative impact on buckling behavior of system but considering CNTs in plate has positive influence.

GLM에서 제약과 비제약 혼합모형의 고찰 및 확장 (Extension and Review of Restricted and Unrestricted Mixed Models in the Generalized Linear Models)

  • 최성운
    • 대한안전경영과학회:학술대회논문집
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    • 대한안전경영과학회 2009년도 춘계학술대회
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    • pp.185-192
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    • 2009
  • The research contributes extending and reviewing of restricted (constrained) and unrestricted (unconstrained) models in GLM(Generalized Linear Models). The paper includes the methodology for finding EMS(Expected Mean Square) and $F_0$ ratio. The results can be applied to the gauge R&R(Reproducibility and Repeatability) in MSA(Measurement System Analysis).

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측정 정밀도 추정을 위한 게이지 실험계획 프로세스 개발 및 적용 (Development and Implementation of Experimental Design Process for Estimating the Measurement Precisions)

  • 최성운
    • 대한안전경영과학회:학술대회논문집
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    • 대한안전경영과학회 2009년도 추계학술대회
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    • pp.557-563
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    • 2009
  • The research develops measurement processes for estimating and evaluating the gauge R&R(Reproducibility & Repeatability) using ANOVA(Analysis of Variance) of experimental design tools. The ten-step processes developed include experimental goal setting, the selection of characteristics(factors, levels), data model, ANOVA, EMS(Expected Mean Square), estimation of gauge precisions, and evaluation indexes. The three-factor combined measurement models are presented to show the processes developed in this paper.

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연구단계와 분야에 따른 한의약 R&D 투자 동향 (The Recent Trend of R&D Investment in Korean Medicine by Research Steps and Fields)

  • 권수현;김동수;안미영;임병묵
    • 대한예방한의학회지
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    • 제21권2호
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    • pp.69-78
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    • 2017
  • Objectives : This study aims to analyze the public investment for Korean Medicine R&D to facilitate the future strategic planning. Methods : All government supported research projects for Korean Medicine that were invested in 2009, 2012, 2015 were searched in the NTIS (National Science & Technology Information Service) Database. Research budgets were analyzed by government departments, R&D agents, R&D steps, and research fields. CAGR (Compound Annual Growth Rate) was derived from each Korean Medicine research field. Differences of research budgets among research fields were tested using Chi square analysis. Results : A total of 891 projects supported in 2009, 2012, and 2015 was analyzed. The amount of research budgets has increased, from 49,839 million won in 2009 to 106,536 million won in 2015 showing 13.5% of CAGR. Ministry of Science, ICT, and Future Planning, and Ministry of Health and Welfare were the biggest sponsors in Korean Medicine R&D. Chi square analysis showed that, in this period, there were statistically significant differences of research budgets in Korean Medicine technology equipment field and infrastructure field. Conclusions : To diversify the Korean Medicine R&D, unequal research funding among government departments should be relieved, and virtuous cycle of Industry-University-Institute Collaboration in Korean Medicine need to be built.

Development of a Predictive Mathematical Model for the Growth Kinetics of Listeria monocytogenes in Sesame Leaves

  • Park, Shin-Young;Choi, Jin-Won;Chung, Duck-Hwa;Kim, Min-Gon;Lee, Kyu-Ho;Kim, Keun-Sung;Bahk, Gyung-Jin;Bae, Dong-Ho;Park, Sang-Kyu;Kim, Kwang-Yup;Kim, Cheorl-Ho;Ha, Sang-Do
    • Food Science and Biotechnology
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    • 제16권2호
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    • pp.238-242
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    • 2007
  • Square root models were developed for predicting the kinetics of growth of Listeria monocytogenes in sesame leaves as a function of temperature (4, 10, or $25^{\circ}C$). At these storage temperatures, the primary growth curves fit well ($R^2=0.898$ to 0.980) to a Gompertz equation to obtain lag time (LT) and specific growth rate (SGR). The square root models for natural logarithm transformations of the LT and SGR as a function of temperature were obtained by SAS's regression analysis. As storage temperature ($4-25^{\circ}C$) decreased, LT increased and SGR decreased, respectively. Square root models were identified as appropriate secondary models for LT and SGR on the basis of most statistical indices such as coefficient determination ($R^2=0.961$ for LT, 0.988 for SGR), mean square error (MSE=0.l97 for LT, 0.005 for SGR), and accuracy factor ($A_f=1.356$ for LT, 1.251 for SGR) although the model for LT was partially not appropriate as a secondary model due to the high value of bias factor ($B_f=1.572$). In general, our secondary model supported predictions of the effects of temperature on both LT and SGR for L. monocytogenes in sesame leaves.

Correlation between the Pressure Pain Threshold and Sonography and Spontaneous Electrical Activity in Myofascial Trigger Points

  • Kim, Hyun-Jin;Kim, Myung-Hoon;Kim, Su-Hyon;Oh, Seok;Choi, Ji-Ho;Kim, Tae-Youl
    • The Journal of Korean Physical Therapy
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    • 제22권3호
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    • pp.17-21
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    • 2010
  • Purpose: This study was designed to investigate possibilities for quantitative analysis using the electromyography and sonography. For better understanding, we evaluated the correlation between the pressure pain threshold and sonography, spontaneous electrical activity in trigger points located in the upper trapezius muscle. Methods: Thirty three active subjects volunteered to participate in this study (n=33). They had a palpable taut band, exquisite spot tenderness of a nodule in a taut band, spontaneous pain, referred pain, jump sign, local twitch response, and a painful limit to full stretch range of motion. We measured Pressure pain threshold, density, white area index, root mean square, and reaction. Pearson’s correlation coefficient was calculated to estimate the relationship between the pressure pain threshold and other variables including density, white area index, root mean square, and reaction time. Results: There were significant correlations between pressure pain threshold and density (r=-0.75, p<0.01), and between pressure pain threshold and white area index (r=-0.74, p<0.01). A significant correlations between pressure pain threshold and root mean square (r=-0.59, p<0.01). The significant correlation was found between pressure pain threshold and reaction time (r=-0.64, p<0.01). Conclusion: These should indicate whether quantitative analysis can be done using the characteristics of electromyography and sonography.

수중 음향 환경에 따른 CDMA와 OFDM 성능 분석 (Performance Analysis of CDMA and OFDM on Underwater Acoustic Environments)

  • 이호준;정재학
    • 한국ITS학회 논문지
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    • 제17권5호
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    • pp.135-142
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    • 2018
  • 본 논문은 수중 음향 채널 환경에 따른 CDMA(code division multiple access)와 OFDM(orthogonal frequency division multiplexing) 전송기법의 장단점을 비교 분석한다. 이를 위해서 r.m.s.(root mean square) 지연시간과 도플러 주파수 그리고 다중 경로의 수를 변화시켜가며 다양한 수중 음향 채널에서 전산 모의실험을 수행하였다. r.m.s. 지연시간과 도플러 주파수가 각 전송기법의 설계치 내의 수치이며 동일한 전송률을 갖는 경우 CDMA가 OFDM에 비해 우수한 성능을 갖는 것을 보였다. 그러나 도플러가 설계치보다 큰 경우에는 CDMA의 성능이 저하되어 OFDM이 CDMA보다 우수한 것을 보였다.

모서리 경계조건을 만족하는 접지된 유전체평면위의 저항띠 격자구조에 의한 TE 산란의 해 (Solution of the TE Scattering by a Resistive Strip Grating Over Grounded Dielectric Plane with Edge Boundary Condition)

  • 윤의중
    • 한국항행학회논문지
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    • 제11권2호
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    • pp.196-202
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    • 2007
  • 본 논문에서는 모서리 경계조건을 만족하는 접지된 유전체층 위의 저항띠 격자구조에 의한 TE(transverse electric)산란 문제를 수치해석 방법인 FGMM(Fourier-Galerkin Moment Method)를 이용하여 해석하였다. TE 산란에 대하여 유도되는 표면 전류밀도는 스트립 양 끝에서 0의 값이 기대되며, 이때 저항띠에 유도되는 표면 전류밀도는 차수가 1인 Gegenbauer (Ultraspherical) 다항식과 적절한 모서리 경계조건을 만족하는 함수의 곱의 급수로 전개하였다. 제안된 방법의 검증을 위하여 기존의 R = 100 ohms/square 및 완전도체 경우인 균일 저항율 R = 0에 대한 정규화된 반사전력의 수치결과는 기존의 논문들과 일치하였다.

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