• 제목/요약/키워드: ${\pi}$ formula

검색결과 63건 처리시간 0.024초

THE CAPABILITY OF PERIODIC NEURAL NETWORK APPROXIMATION

  • Hahm, Nahmwoo;Hong, Bum Il
    • Korean Journal of Mathematics
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    • 제18권2호
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    • pp.167-174
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    • 2010
  • In this paper, we investigate the possibility of $2{\pi}$-periodic continuous function approximation by periodic neural networks. Using the Riemann sum and the quadrature formula, we show the capability of a periodic neural network approximation.

버블자성재료의 제조 및 자기 특성에 관한 연구 (A Study on the Fabrication Process and Magnetic Properties of Buble Magnetic Materials.)

  • 박용두;김종오
    • 한국재료학회지
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    • 제5권8호
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    • pp.1040-1044
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    • 1995
  • Sm의 농도가 각각 0.3, 0.4, 0.6인 세종류인(YSmLuCa)$_3$(FeGe)$_{5}$ $O_{12}$ 가넷트 박막을 LPE법으로 비자성재료인 Gd$_3$Ga$_{5}$ $O_{12}$(GGG)기판상에 성장시켜, 버블 자성재료의 자기적 성질을 조사하였다. 공명폭 ΔH는 4$\pi$Ms의 증가에 따라 증가하였고 Sm 농도의 감소에 따라 감소한다. 수직 자기 이방성에너지 Ku는 Sm증가에 따라 증가하며 같은 Sm농도에서는 4$\pi$Ms의 증가에 따라 증가한다. 자벽 이동도는 4$\pi$Ms의 증가에 따라 증가하며 Sm의 증가에 따라 감소한다. Ms.ΔH의 곱이 일정한 사실로 부터 새로운 자기손실인자 Eι을 구할 수 있으며 이는 Sm의 농도에 의존한다.ι을 구할 수 있으며 이는 Sm의 농도에 의존한다.

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중국 논문에 나타난 건선의 변증 분석 및 변증체계에 대한 고찰 (A Review on Patterns and Classification Criteria of Psoriasis by analyzing Chinese Theses)

  • 조은채;김규석
    • 한방안이비인후피부과학회지
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    • 제33권2호
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    • pp.112-129
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    • 2020
  • Objectives : The aim of this study is to explore the types of pattern identification (PI, 辨證) and the differential points of PI used for the treatment of psoriasis in Traditional Chinese Medicine (TCM) based on the Chinese references and to provide the evidences applying PI for the treatment of psoriasis in clinical practice. Methods : This study extracted patterns of psoriasis through database CNKI (China National Knowledge Infrastructure) and analysis the patterns and classification criteria of the patterns. Those examined in the study are dermal symptoms, general symptoms, formula and herbs which are different depending on the patterns. Results : Total 60 studies were selected and 44 pattern types were extracted from them. We categorized the main pattern types on psoriasis used in TCM as 'blood-heat syndrome(BHS, 血熱證)', blood-stasis syndrome(BSS, 血瘀證), and 'blood-dryness syndrome(BDS, 血燥證)', 'dampness-heat syndrome(DHS, 濕熱證)' and 'yang-deficiency syndrome(YDS, 陽虛證)'. Among these patterns, BHS was the most common. In TCM, the pattern of BHS tended to have skin symptoms and signs related to inflammatory erythema and heat. Both BSS and BDS were characterized by long disease duration and poor healing. In addition, DHS tended to have the skin symptoms and signs such as oozing and severe itching. The symptoms and signs related to coldness mainly showed in YDS. For PI criteria, 'qi-blood-essence criteria(氣血津液辨證)' and 'eight-doctrine criteria(八鋼辨證) are commonly used. Conclusions : Our findings show that each PI on psoriasis in TCM has different characteristics related to dermal and general symptoms or signs. Further studies are needed to develop the diagnostic tool of PI on psoriasis reflecting on clinical practices in Korean Medicine by referring to the findings of this study about PI on psoriasis in TCM.

지글러-니콜스 제어파라미터 조정법(1),(2)의 상호 연관성에 대한 해석적 연구 (An Analytic Study On the Mutual Relation between Method(1) and (2) of ZIEGLER-NICHOLS Control Parameter Tuning)

  • 강인철;최순만;최재성
    • 한국마린엔지니어링학회:학술대회논문집
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    • 한국마린엔지니어링학회 2001년도 추계학술대회 논문집(Proceeding of the KOSME 2001 Autumn Annual Meeting)
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    • pp.112-119
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    • 2001
  • Parameter tuning methods by Ziegler-Nickels for control systems are generally classified into Z-N(1) and Z-N(2). The purpose of this paper is to describe what relations exist between methods of Z-N(1) and Z-N(2), or how Z-N(1) method can be originated from Z-N(2) method by analyzing one loop control system of P or PI controller and time delay process. The formulas of Z-N(1) consist of process parameters, L(time delay), $K_m$(gain) and $T_m$(time constant), but Z-N(2) method is based only on the ultimate gain $K_u$ and the ultimate period $T_u$ acquired normally by practical trial without any parameters of Z-N(1). In this paper, for the first step to seek mutual relations, the simple formulas of Z-N(2) are transformed into the formulas composed of the same parameters as Z-N(1) which is derived from the analysis of frequency characteristics. Then, the approximation of the actual ultimate frequency is proposed as important premise in the translation between Z-N(1) and (2). Such equalization and approximation brings a simple approximated formula which can explain how Z-N(1) is originated from the Z-N(2) in the form of formula. And a model system is adopted to compare the approximated formula to Z-N(1) and Z-N(2) methods, the results of which show the effectiveness of the proposals.

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대구지방의 증발량에 대한 통계학적 연구 (A Statistical Study Evaporation tn DAEGU Area)

  • 김영기
    • 한국농공학회지
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    • 제15권4호
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    • pp.3160-3169
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    • 1973
  • Rainfall, evaporation, and permeability of water are the most important factors in determining the demand of water. The Daegu area has only a meteorologi observatory and there is not sufficient data for adapting the advanced method for derivation of the estimated of evaporation in the Daegu area. However, by using available data, the writer devoted his great effort in deriving the most reasonable formula applicable to the Daegu area and it is adaptable for various purposes such as industry and estimation of groundwater etc. The data used in this study was the monthly amount of evaporation of the Daegu area for the past 13 years(1960 to 1970). A year can be divided into two groups by relative degrees of evaporation in this area: the first group (less evaporation) is January, February, March, October, November, and December, and the second (more evaporation) is April, May, June, July, August, and September. The amount of evaporation of the two groups were statistically treated by the theory of probability for derivation of estimated formula of evaporation. The formula derved is believed to fully consider. The characteristic hydrological environment of this area as the following shows: log(x+3)=0.8963+0.1125$\xi$..........(4, 5, 6, 7, 8, 9 month) log(x-0.7)=0.2051+0.3023$\xi$..........(1, 2, 3, 10, 11, 12 month) This study obtained the above formula of probability of the monthly evaporation of this area by using the relation: $F_(x)=\frac{1}{{\surd}{\pi}}\int\limits_{-\infty}^{\xi}e^{-\xi2}d{\xi}\;{\xi}=alog_{\alpha}({\frac{x_0+b'}{x_0+b})\;(-b<x<{\infty})$ $$log(x_0+b)=0.80961$ $$\frac{1}{a}=\sqrt{\frac{2N}{N-1}}\;Sx=0.1125$$ $$b=\frac{1}{m}\sum\limits_{i-I}^{m}b_s=3.14$$ $$S_x=\sqrt{\frac{1}{N}\sum\limits_{i-I}^{N}\{log(x_i+b)\}^2-\{log(x_i+b)\}^2}=0.0791$$ (4, 5, 6, 7, 8, 9 month) This formula may be advantageously applied to estimation of evaporation in the Daegu area. Notation for general terms has been denoted by following: $W_(x)$: probability of occurance. $$W_(x)=\int_x^{\infty}f(x)dx$$ P : probability $$P=\frac{N!}{t!(N-t)}{F_i^{N-{\pi}}(1-F_i)^l$$ $$F_{\eta}:\; Thomas\;plot\;F_{\eta}=(1-\frac{n}{N+1})$$ $X_l\;X_i$: maximun, minimum value of total number of sample size(other notation for general terms was used as needed)

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Simple Two-Degree of Freedom PID Controllers Tuning Table Based on CDM

  • Benjanarasuth, Taworn;Ngamwiwit, Jongkol;Komine, Noriyuki
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 2004년도 ICCAS
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    • pp.256-261
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    • 2004
  • This paper presents a simple two-degree of freedom PID tuning table based on the CDM design method. The structure of the control system will be composed of plant, P or PI or PID controller and a pre-filter. The finalized formula can be used based on the experimental test of the plant in the same manner as the Ziegler-Nichols' second method. That is; users just need to find the critical gain and critical period experimentally and the parameters of the P, PI or PID controller with the pre-filter can be obtained by substituting the values of critical gain and critical period in the tuning table. The simulation results of the control systems utilizing the proposed controllers compared with those using the Ziegler-Nichols' second method will also be demonstrated.

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잰킷 행렬을 이용한 저밀도 부호의 구성 (Low Density Codes Construction using Jacket Matrices)

  • 문명룡;이광재;;황기연;이문호
    • 대한전자공학회논문지TC
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    • 제42권8호
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    • pp.1-10
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    • 2005
  • 본 논문에서는 대수 이론과 관련된 일반화된 치환 행렬로부터 저밀도 부호의 명시적 구성을 고찰하였으며, 순환공식과 치환행렬에 관한 재킷 역 블록 행렬을 설계하였다. 설계 결과로부터 제안 기법은 저밀도 부호를 얻기 위한 간단하며, 고속화된 기법임을 알 수 있다. 또한, $\pi$-회전 LDPC(low density parity check) 부호와 같은 구조화 LDPC 부호 역시 저밀도 재킷 역 블록 행렬임을 증명하였다.

Oral Delivery of Probiotics Using pH-Sensitive Phthalyl Inulin Tablets

  • Kim, Whee-Soo;Cho, Chong-Su;Hong, Liang;Han, Geon Goo;Kil, Bum Ju;Kang, Sang-Kee;Kim, Dae-Duk;Choi, Yun-Jaie;Huh, Chul Sung
    • Journal of Microbiology and Biotechnology
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    • 제29권2호
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    • pp.200-208
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    • 2019
  • Probiotics show low cell viability after oral administration because they have difficulty surviving in the stomach due to low pH and enzymes. For the oral delivery of probiotics, developing a formula that protects the probiotic bacteria from gastric acidity while providing living cells is mandatory. In this study, we developed tablets using a new pH-sensitive phthalyl inulin (PI) to protect probiotics from gastric conditions and investigated the effects of different compression forces on cell survival. We made three different tablets under different compression forces and measured survivability, disintegration time, and kinetics in simulated gastric-intestinal fluid. During tableting, there were no significant differences in probiotic viability among the different compression forces although disintegration time was affected by the compression force. A higher compression force resulted in higher viability in simulated gastric fluid. The swelling degree of the PI tablets in simulated intestinal fluid was higher than that of the tablets in simulated gastric fluid due to the pH sensitivity of the PI. The probiotic viability formulated in the tablets was also higher in acidic gastric conditions than that for probiotics in solution. Rapid release of the probiotics from the tablet occurred in the simulated intestinal fluid due to the pH sensitivity. After 6 months of refrigeration, the viability of the PI probiotics was kept. Overall, this is the first study to show the pH-sensitive properties of PI and one that may be useful for oral delivery of the probiotics.

H형(形) 강(鋼) 보의 횡좌굴(橫挫屈)에 관(關)한 연구(硏究) (A Study On Lateral Buckling Of H-Section Steel Beams)

  • 김석중
    • 산업기술연구
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    • 제4권
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    • pp.29-35
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    • 1984
  • Buckling is a significant behavior to be considered whenever we design steel structures. In the case of H-shape beams, the lateral buckling occured by bending moment must be considered. Because of the lateral buckling of H-shape beams, the bending strength of the beams are determined by the lateral buckling stress instead of the allowable bending stress. Lateral buckling stress equation, consisting of two terms, i. e. ${\sigma}_{cr}({\nu},{\omega})={\sqrt{[{\sigma}_{cr}({\nu})]^2+[{\sigma}_{cr}({\omega})]^2}}$ has been using, but for the practical purpose of use the following equations are using two, i. e. ${\sigma}_{cr}({\nu})={\frac{0.65E}{{\ell}_h/A_f}}$, ${\sigma}_{cr}({\omega})={\frac{{\pi}^2E}{({\ell}_b/i_b)^2}}$. When we use the above equations, the results are different according to the shape of beam section, and they a re rather complex. In this study lateral buckling stress equation is derived, and the proposed formula$({\sigma}_{cr}(t))$ is compared with above mentioned two basic and practical equations. To verify the proposed formula experimentaly, 16H-shape beams which have different slender ratios arc tested by applying pure bending momet. Through the experiments the buckling behavior of H-shape beams is clarified, and the results shows that the proposed formula$({\sigma}_{cr}(t))$ is accurate enough for practical purpose.

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Flexural performance of composite beams with open-web π-shaped steel partially-encased by concrete

  • Liusheng Chu;Yunhui Chen;Jie Li;Yukun Yang;Danda Li;Xing Ma
    • Steel and Composite Structures
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    • 제50권4호
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    • pp.419-428
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    • 2024
  • Prefabricated partially-encased composite (PEC) structural component is widely used in construction industry due to its superior structural performance and easy assembly characteristic. However, the solid web in traditional PEC components tends to split concrete into two halves, thus potentially reduces structural integrity and requires double concrete pouring. To overcome the above disadvantages, a new PEC beam with open-web π-shaped steel is proposed in this paper. Four open-web PEC beams with varying sectional height, flange thickness and web void rate were constructed and tested under flexural loads. During experimental tests, all beams exhibited typical flexural failure modes with strong moment capacities and excellent ductility. Owing to the unique construction form of web opening, steel-concrete bonding properties were enhanced and very small relative steel-concrete slips were observed. Experimental results also showed that the flexural capacity of such PEC beams increased with the increase of the sectional height and flange thickness, while was not affected by the web void rate. At last, a flexural capacity formula of the open-web PEC beam was proposed based on the whole section plastic rule. The formula results agreed well with experimental results.