• Title/Summary/Keyword: Formulas

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An Analysis of the Contents and Expression Methods of Jeong Yag-yong's 『Gugo Wonlyu』 (정약용의 『구고원류』의 내용과 표현방법 분석)

  • Lee, Kyung Eon
    • Journal for History of Mathematics
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    • v.29 no.1
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    • pp.1-16
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    • 2016
  • This study analyzes the contents and expression methods of Jeong Yag-yong's "Gugo Wonlyu". The 530-page long "Gugo Wonlyu" discusses 1541 formulas about Gu, Go, Hyun, Hwa, Gyo; however, it has only the results of formulas and no explanations about their inducement method. Therefore we do not know how he derives and verifies the formulas. In addition, it did not follow the basic form of oriental mathematics textbooks: problem-answer-solution, and presented all the formulas only with characters without using numbers. This is a very distinctive aspect compared to other mathematical textbooks. In addition, the formulas about 5-Hwa and 5-Gyo are addressed exactly in fixed order and covers a formula in various directions. This is a clear evidence that Jeong Yag-yong analyzed and studied the Gugosul thoroughly.

Experimental investigation of characteristics of torsional wind loads on rectangular tall buildings

  • Li, Yi;Zhang, J.W.;Li, Q.S.
    • Structural Engineering and Mechanics
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    • v.49 no.1
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    • pp.129-145
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    • 2014
  • In order to investigate the characteristics of torsional wind loads on rectangular tall buildings, five models with different rectangular cross-sections were tested in a boundary wind tunnel. Based on the test results, the RMS force coefficients, power spectrum densities as well as vertical correlation functions of torsional wind loads were analyzed. Formulas that took the side ratio as parameters were proposed to fit the test results above. Comparisons between the results calculated by the formulas and the wind tunnel measurements were made to verify the reliability of the proposed formulas. An simplified expression to evaluate the dynamic torsional wind loads on rectangular tall buildings in urban terrain is presented on basis of the above formulas and has been proved by a practical project. The simplified expressions as well as the proposed formulas can be applied to estimate wind-induce torsional response on rectangular tall buildings in the frequency domain.

A recursive approach for mechanical system design sensitivity analysis

  • Daesung Bae
    • Transactions of the Korean Society of Machine Tool Engineers
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    • v.10 no.1
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    • pp.101-111
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    • 2001
  • Recursive formulas have been effective in solving the equations of motion for large scale constratined mechanical sys-tems. However, derivation of the formulas has been limited to individual terms in the equations of motion, such as veloci-ty, acceleration. and generalized forces. The recursive formulas are generalized in this paper. The velocity transformation method is employed to transform the equations of motion from Cartesian to the joint spaces. Computational structure of the equations of motion in the joint space is carefully examined to classify all necessary computational operations into sev-eral categories. The generalized recursive formula for each category is then developed and applied whenever such a cate-gory of computation is encountered. Since the velocity transformation method yields the equations of motion in a compact form and computational efficiency is achieved by generalized recursive formulas, the proposed method is not only easy to implement but is also efficient. A library of generalized recursive formulas is developed to implement a dynamic analysis algorithm using backward difference.

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A Study on the Distribution of Temperature by Moving Heat Source during Welding (용접중 이동하는 열원에 의한 온도분포에 관한 연구)

  • 왕지석
    • Journal of Advanced Marine Engineering and Technology
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    • v.6 no.2
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    • pp.51-68
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    • 1982
  • A method of calculation of temperature distribution during welding was studied and compared with the existing formulas and experimental results. In contrast to the existing formulas which are founded on the suppositions that the heat source is a point and that the dimensions of welded pieces are infinite, we tried to make the distribution of calorific density of heat source approach reality more closely, so we considered it as a normal distribution of Gauss, and we presented the formulas for calculation of temperature during welding. We also used the principle of superposition for the temperature calculations of finite welded pieces. We compared the formulas presented in this paper with the existing formulas by calculations for the welding of various materials, and considerable differences around the heat source were convinced. The thermal cycles of various points were traced through the welding experiments for the mild steel, and they were compared with the results of calculations.

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A Study on Routine Formulas and Downgraders of Request Act in High School English Textbooks

  • Yang, Eun-Mi
    • English Language & Literature Teaching
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    • v.11 no.2
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    • pp.111-134
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    • 2005
  • This paper examines high school English textbooks to ascertain if they appropriately reflect the kinds and frequencies of routine formulas and downgraders of request act used by English native speakers. It is important to present authentic routine formulas in textbooks for students to acquire proper, efficient and safe communication strategies to communicate with other English speakers. For the analysis, currently available 7 series of 21 high school English textbooks under the $7^{th}$ National Curriculum were selected. Each series of textbooks contains 3 school grade textbooks as High School English, High School English I, and High School English II. The results show that the high school English textbooks generally demonstrate a secund reflection of the English native speakers' use of request strategies and downgraders. That is, the textbooks were found to have presented mostly casual forms of routine formulas while they have not presented sufficient coverage of elaborated polite routine formulas for requesting which English native speakers frequently use. The presence of some kinds of the frequently used downgraders was also very small in proportion in the textbooks. More effort should be given to complement the deficiency in this area by teachers and researchers.

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A STUDY ON THE SEDIMENT AND THE RIVER BED VARIATION (하천의 유사량과 하상변동에 관한 연구)

  • 남선우
    • Water for future
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    • v.11 no.1
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    • pp.47-58
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    • 1978
  • This study is concerned with the analysis of the formulas which give both the quantity of the total, suspended and bed loads as functions of stream and sediment characteristics. The numerical analysis of sediment discharge formulas is described and the computer program for the following 4 formulas are developed; (1) Einstein's Formula (2) Toffaleti's Formula (3) Brown's Formula (4) Kikkawa's Formula In the analysis of these formulas, the hydraulic data of the river in the downstream of the Han River are used, and these formulas have been tested by application and comparison with observed data and the results computed by the computer. In these methods and procedures, the most satisfactory and convenient formula is selected. The design and planning of the river channel regulation works are determined by computing the river bed variation by using the sediment discharge computed from the selected formula.

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Development of Audible Noise Prediction Formulas Applied to HVAC Transmission Lines Design by Using Genetic Programming (유전프로그래밍에 의한 초고압 송전선로 환경설계용 코로나 소음 예측계산식 개발)

  • Yang, Kwang-Ho;Hwang, Gi-Hyun;Park, June-Ho;Park, Jong-Keun
    • The Transactions of the Korean Institute of Electrical Engineers A
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    • v.50 no.5
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    • pp.234-240
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    • 2001
  • Audible noise (AN) produced by corona discharges from high voltage transmission lines is one of the more important considerations in line design. Therefore, line designers must pre-determine the AN using prediction formulas. This paper presents the results of applying evolutionary computation techniques using AN data from lines throughout the world to develop new, highly accurate formulas for predicting a A-weighted AN during heavy rain and stable rain from overhead ac lines. Calculated ANs using these new formulas and existing formulas are compared with measured data.

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Evaluation and Adjustment of Dynamic Pile-Driving Formulas (말뚝 지지력 산정을 위한 동역학적 공식의 정확도 분석 및 수정)

  • Chung, Choong Ki;Kim, Myoung Mo
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.5 no.4
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    • pp.23-30
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    • 1985
  • Dynamic pile-driving formulas are widely used in predicting the load capacity of piles in cohesionless soils. However, the accuracy of the formulas has been questioned for a long time due to their oversimplified assumptions and empirical parameters involved in the formulas. The allowable pile capacities calculated by 6 different dynamic pile-driving formulas are compared statistically with the capacities measured in the field, in this paper, to find out the correlations between the calculated capacities and the measured values. The statistical data are then used to evaluate and to adjust the formulas to improve their accuracy. For the greatest accuracy and simplicity of use, it is recommended that the adjusted form of Gates formula be used. When the result of this recommended formula is compared with that of the existing Olson's modified formula, the former is found to be conservative by more than 10 percents.

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Anti-atherosclerotic Effects of Herbal Formulas for Sasang Constitutional Medicine (사상 체질 처방의 항동맥경화 효능 비교 연구 -열다한소탕, 양격산화탕, 청심연자탕, 태음조위탕-)

  • Kim, Ohn-Soon;Kim, Ye-Ji;Shin, Hyeun-Kyoo
    • Journal of Sasang Constitutional Medicine
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    • v.24 no.4
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    • pp.51-61
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    • 2012
  • Objectives : The purpose of this study was to investigate the anti-atherosclerotic effects of 4 herbal formulas for Sasang constitutional medicine (Yeoldahanso-tang: YDHST, Yanggyeoksanhwa-tang: YGSHT, Cheongsimyeonja-tang: CSYJT and Taeeumjowi-tang: TEJWT). Methods : The antioxidant activities of herbal formulas were studied by measuring free radical scavenging activities on ABTS and DPPH. The inhibitory effects on LDL oxidation was evaluated by the formation of TBARS, REM and fragmentation of apolipoprotein B-100 (ApoB). Effects of herbal formulas on macrophage lipid accumulation were determined in native LDL and LPS co-incubated macrophages using Oil Red O staining. Results : The scavenging activities on ABTS and DPPH of herbal formulas were increased in dose-dependent manner (YDHST>YGSHT>CSYJT>TEJWT). Herbal formulas reduced the oxidation properties of LDL induced by $CuSO_4$. YDHST, YGSHT and CSYJT showed strong suppressive effect on LDL oxidation than TEJWT. In addition, YDHST, YGSHT and CSYJT significantly inhibited foam cell formation in LDL/LPS stimulated RAW 264.7 cells. Conclusions : These results demonstrate that YDHST, YGSHT and CSYJT have potentials on anti-atherosclerosis by antioxidative effect and suppressive effect on LDL oxidation.

Hepatoprotective Effects of 25 Herbal Formulas in Primary Rat Hepatocytes (한약 처방 25종에 대한 간 보호 효과 비교 연구)

  • Jin, Seong Eun;Jeong, Soo-Jin;Shin, Hyeun-Kyoo;Ha, Hyekyung
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.27 no.5
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    • pp.617-624
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    • 2013
  • The purpose of this study is to investigate the protective effects of 25 herbal formulas on acetaminophen (APAP) or D-galactosamine (D-GalN)-induced hepatotoxicity in primary rat hepatocytes. Cell viability was measured using by Cell Counting Kit-8. 15 kinds of herbal formulas significantly reversed the cell viabilities of D-GalN-treated rat hepatocytes compared with D-GalN alone (p<0.05). In particular, 9 herbal formulas (Bangpungtongseong-san, Bojungikgi-tang, Galgeun-tang, Gumiganghwal-tang, Guibi-tang, Sagunja-tang, Samsoeum, Pyeongwi-san and Yijin-tang) showed the potent protective effects. However, 8 herbal formula exerted weak protective effects and 2 herbal formula did not exert effects on hepatotoxicity by D-GalN. On APAP-induced hepatotoxicity, 7 kinds of herbal formulas increased the viabilities of hepatocytes compare with APAP alone (p<0.05). These results could be provide a valuable information for the future in vivo or clinical studies to predict the hepatoprotective effects of herbal formulas.