• Title/Summary/Keyword: $P_{max}$

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SERKOWSKI'S EMPIRICAL RELATION FOR INTERSTELLAR LINEAR POLARIZATION VIEWED FROM DAVIS-GREENSTEIN ALIGNMENT MECHANISM

  • Hong, Seung-Soo;Lee, Hyung-Mok
    • Journal of The Korean Astronomical Society
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    • v.11 no.1
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    • pp.31-36
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    • 1978
  • Although Serkowski used a single value K=1.15 in representing all the observed interstellar linear polarization curves by his empirical relation $p({\lambda})/P_{max}$=exp (-K $1n^2({\lambda}_{max}/{\lambda})$), where $p_{max}$ is the maximum polarization at wavelength ${\lambda}_{max}$, we have noticed a meaningful variation in K from observations of 72 stars. By comparing K's with $P_{max}/E_{B-V}\;and\;with\;{\lambda}_{max}$, we have examined how the shape of the polarization curve is related with the degree of grain alignment on one hand, and with grain sizes on the other. We have shown that correlations between K, $P_{max}/E_{B-V}\;and\;with\;{\lambda}_{max}$, are consistent with the idea of Davis-Greenstein mechanism for grain alignment.

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Oxidation Stability Model of Fish Oil (어유의 산화안정성 예측)

  • Jeong-Hwa Hong;Jin-Woo Kim;Dae-Seok Byun
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.24 no.3
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    • pp.384-388
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    • 1995
  • High content of polyunsaturated fatty acid in fish oil makes it very susceptible to oxidation, which prevent fish oil from successful application to food processing or functional foods. To resolve this problem, oxidation stability model of fish oil was developed using the following differential equation : $dp/dt=k{\cdot}p(t){\cdot}[P_{max}\;-\;p(t)]$. This differential equation can be intergrated using analytical techniques to give : $p(t)=P_{max}/[1\;+\;[(P_{max}/P_{(0)})\;-\;-1]{\cdot}EXP(-K_p{\cdot}t)]$. At 50, 60, 70 and $80^{\circ}C,\;K_p$ were 0.00535, 0.01345, 0.02516 and 0.04675, respectively. The proposed model was well agreed with the measured data except for some minor deviations. In addition, $K_p$ was expressed as a function of temperature : $K_p=(1/P_{max})EXP\;[1\;-\;(8148/T)+20.1]$. Where T is absolute temperature($^{o}K$).

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The Usefulness of Dyspnea Rating in Evaluation for Pulmonary Impairment/Disability in Patients with Chronic Pulmonary Disease (만성폐질환자의 폐기능손상 및 장애 평가에 있어서 호흡곤란정도의 유용성)

  • Park, Jae-Min;Lee, Jun-Gu;Kim, Young-Sam;Chang, Yoon-Soo;Ahn, Kang-Hyun;Cho, Hyun-Myung;Kim, Se-Kyu;Chang, Joon;Kim, Sung-Kyu;Lee, Won-Young
    • Tuberculosis and Respiratory Diseases
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    • v.46 no.2
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    • pp.204-214
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    • 1999
  • Background: Resting pulmonary function tests(PFTs) are routinely used in the evaluation of pulmonary impairment/disability. But the significance of the cardiopulmonary exercise test(CPX) in the evaluation of pulmonary impairment is controvertible. Many experts believe that dyspnea, though a necessary part of the assessment, is not a reliable predictor of impairment. Nevertheless, oxygen requirements of an organism at rest are different from at activity or exercising, and a clear relationship between resting PFTs and exercise tolerance has not been established in patients with chronic pulmonary disease. As well, the relationship between resting PFTs and dyspnea is complex. To investigate the relationship of dyspnea, resting PFTs, and CPX, we evaluated the patients of stabilized chronic pulmonary disease with clinical dyspnea rating(baseline dyspnea index, BDI), resting PFTs, and CPX. Method: The 50 patients were divided into two groups: non-severe and severe group on basis of results of resting PFTs(by criteria of ATS), CPX(by criteria of ATS or Ortega), and dyspnea rating(by focal score of BDI). Groups were compared with respect to pulmonary function, indices of CPX, and dyspnea rating. Results: 1. According to the criteria of pulmonary impairment with resting PFTs, $VO_2$max, and focal score of BDI were significantly low in the severe group(p<0.01). According to the criteria of $VO_2$max(ml/kg/min) and $VO_2$max(%), the parameters of resting PFTs, except $FEV_1$ were not significantly different between non-severe and severe(p>0.05). According to focal score($FEV_1$(%), FVC(%), MW(%), $FEV_1/FVC$, and $VO_2$max were significantly lower in the severe group(p<0.01). However, in the more severe dyspneic group(focal score<5), only $VO_2$max(ml/kg/min) and $VO_2$max(%) were low(p<0.01). $FEV_1$(%) was correlated with $VO_2$max(%)(r=0.52;p<0.01), but not predictive of exercise performance. The focal score had the correlation with max WR(%) (r=0.55;p<0.01). Sensitivity and specificity analysis were utilized to compare the different criteria used to evaluate the severity of pulmonary impairment, revealed that the classification would be different according to the criteria used. And focal score for dyspnea showed similar sensitivity and specificity. Conclusion : According to these result, resting PFTs were not superior to rating of dyspnea in prediction of exercise performance in patients with chronic pulmonary diseases and less correlative with focal score for dyspnea than $VO_2$max and max WR. Therefore, if not contraindicated, CPX would be considered to evaluate the severity of pulmonary impairment in patients with chronic pulmonary diseases, including with severe resting PFTs. Current criteria used to evaluate the severity of impairment were insufficient in considering the degree of dyspnea, so new criteria, including the severity of dyspnea, may be necessary.

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Dynamic Economic Load Dispatch Problem Applying Valve-Point Balance and Swap Optimization Method (밸브지점 균형과 교환 최적화 방법을 적용한 동적경제급전문제)

  • Lee, Sang-Un
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.16 no.1
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    • pp.253-262
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    • 2016
  • This paper proposes a balance-swap method for the dynamic economic load dispatch problem. Based on the premise that all generators shall be operated at valve-points, the proposed algorithm initially sets the maximum generation power at $P_i{\leftarrow}P_i^{max}$. As for generator i with $_{max}c_i$, which is the maximum operating cost $c_i=\frac{F(P_i)-F(P_{iv_k})}{(P_i-P_{iv_k})}$ produced when the generation power of each generator is reduced to the valve-point $v_k$, the algorithm reduces i's generation power down to $P_{iv_k}$, the valve-point operating cost. When ${\Sigma}P_i-P_d$ > 0, it reduces the generation power of a generator with $_{max}c_i$ of $c_i=F(P_i)-F(P_i-1)$ to $P_i{\leftarrow}P_i-1$ so as to restore the equilibrium ${\Sigma}P_i=P_d$. The algorithm subsequently optimizes by employing an adult-step method in which power in the range of $_{min}\{_{max}(P_i-P_i^{min}),\;_{max}(P_i^{max}-P_i)\}$>${\alpha}{\geq}10$ is reduced by 10; a baby step method in which power in the range of 10>${\alpha}{\geq}1$ is reduced by 1; and a swap method for $_{max}[F(P_i)-F(P_i-{\alpha})]$>$_{min}[F(P_j+{\alpha})-F(P_j)]$, $i{\neq}j$ of $P_i=P_i{\pm}{\alpha}$, in which power is swapped to $P_i=P_i-{\alpha}$, $P_j=P_j+{\alpha}$. It finally executes minute swap process for ${\alpha}=\text{0.1, 0.01, 0.001, 0.0001}$. When applied to various experimental cases of the dynamic economic load dispatch problems, the proposed algorithm has proved to maximize economic benefits by significantly reducing the optimal operating cost of the extant Heuristic algorithm.

ON THE LEET INVERSIVE SEMIRING CONGRUENCES ON ADDITIVB REGULAR SEMIRINGS

  • SEN M. K.;BHUNIYA A. K.
    • The Pure and Applied Mathematics
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    • v.12 no.4 s.30
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    • pp.253-274
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    • 2005
  • An additive regular Semiring S is left inversive if the Set E+ (S) of all additive idempotents is left regular. The set LC(S) of all left inversive semiring congruences on an additive regular semiring S is a lattice. The relations $\theta$ and k (resp.), induced by tr. and ker (resp.), are congruences on LC(S) and each $\theta$-class p$\theta$ (resp. each k-class pk) is a complete modular sublattice with $p_{min}$ and $p_{max}$ (resp. With $p^{min}$ and $p^{max}$), as the least and greatest elements. $p_{min},\;p_{max},\;p^{min}$ and $p^{max}$, in particular ${\epsilon}_{max}$, the maximum additive idempotent separating congruence has been characterized explicitly. A semiring is quasi-inversive if and only if it is a subdirect product of a left inversive and a right inversive semiring.

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Physicochemical Characteristics for the Transformation of Blue Pigments from Genipin of Gardenia jasminoides with Amino Acids (치자 Genipin과 아미노산의 청색소변환반응에 관한 물리화학적 연구)

  • Lee, Jae-Youn;Hahn, Tae-Ryong;Paik, Young-Sook
    • Applied Biological Chemistry
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    • v.41 no.5
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    • pp.399-404
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    • 1998
  • Genipin was obtained from hydrolysis of geniposide isolated from gardenia fruits with ${\beta}-glucosidase$. Reaction of genipin with glycine, alanine, histidine, lysine, phenylalanine and glutamate in aqueous buffer solution converted colorless starting materials to blue pigments. Effect of pH for the formation of blue pigments was tested using UV/Vis spectrophotometer. The optimum pH for the formation of blue pigments was 7.0. No pigment and trace amounts were formed at acidic (pH 3.0) and alkaline (pH 12.0) conditions, respectively. The amount and tincture of blue color were distinct with different amino acids. In contrast with lysine $({\lambda}_{max}=573\;nm)$, glycine $({\lambda}_{max}=595\;nm)$, phenylalanine $({\lambda}_{max}=602\;nm)$ and alanine $({\lambda}_{max}=595\;nm)$, the reaction of genipin with histidine $({\lambda}_{max}=601\;nm)$ and glutamate $({\lambda}_{max}=601\;nm)$ produced relatively small amounts of blue pigments. Rate constants for the formation of blue pigments from genipin with amino acids at various temperatures $(60,\;70,\;80,\;90^{\circ}C,\;pH\;7.0\;phosphate\;buffer)$ were obtained. Rate constants of genipin with basic amino acids were larger than neutral or acidic amino acids. Arrhenius activation energies of the formation of blue pigments indicated that activation energy of glycine $(E_A=9.8\;kcal/mol)$ was especially lower than those of other amino acids $(E_A=13.3{\sim}15.4\;kcal/mol)$.

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Seasonal Photosynthetic Performance of Laminaria japonica sporophytes on the Southeastern Coast of Korea (한국 동남해안에서 다시마(Laminaria japonica) 포자체의 광합성의 계절변화)

  • Kang, Rae-Seon;Koh, Chul-Hwan
    • The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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    • v.4 no.3
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    • pp.237-245
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    • 1999
  • Rates of photosynthesis and respiration of Laminaria japonica sporophytes cultivated on the southeastern coast of Korea were monthly measured in situ and under constant temperature and nitrogen concentration in laboratory from February to July 1996 in order to understand the seasonal photosynthetic performance of this alga. P-I (the relationship between photosynthsis and irradiance) parameters measured in situ varied seasonally. Photosynthetic capacity ($P_{max}$) reached its maximum in March (6.64 mg $O_2{\cdot}gdw^{-1}{\cdot}h^{-1}$) and gradually decreased thereafter. Photosynthetic efficiency (${\alpha}$), which ranged from 0.026 to 0.106, generally showed a similar pattern with the $P_{max}$, curve. Correlation between respiration and $P_{max}$, was not significant (Spearman's rank correlation, p>0.05); respiration rate, which varied between 0.25 and 0.83 mg $O_2{\cdot}gdw^{-1}{\cdot}h^{-1}$, showed no gradual decline from March. $P_{max}$ in situ significantly correlated with the relative growth rate of frond weight (Spearman's rank correlation, p<0.01) and this result means that the amount of accumulated materials in body increased with the increment of $P_{max}$. Compared $P_{max}$, in situ with that in the laboratory. The lower $P_{max}$ in February was probably caused by the effect of lower seawater temperature at this time. The decrease in $P_{max}$ after March, however, was primarily attributable to the thickness of blade as the plants got old. Comparison of P-I parameters measured for different size groups in April, explained the negative relationship between $P_{max}$ and frond thickness.

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A Swap Optimization for Dynamic Economic Dispatch Problem with Non-smooth Function (비평활 발전비용함수를 가진 동적 경제급전문제의 교환 최적화)

  • Lee, Sang-Un
    • Journal of the Korea Society of Computer and Information
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    • v.17 no.11
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    • pp.189-196
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    • 2012
  • This paper proposes Swap algorithm for solving Dynamic Economic Dispatch (DED) problem. The proposed algorithm initially balances total load demand $P_d$ with total generation ${\Sigma}P_i$ by deactivating a generator with the highest unit generation cost $C_i^{max}/P_i^{max}$. It then swaps generation level $P_i=P_i{\pm}{\Delta}$, (${\Delta}$=1.0, 0.1, 0.01, 0.001) for $P_i=P_i-{\Delta}$, $P_j=P_j+{\Delta}$ provided that $_{max}[F(P_i)-F(P_i-{\Delta})]$ > $_{min}[F(P_j+{\Delta})-F(P_j)]$, $i{\neq}j$. This new algorithm is applied and tested to the experimental data of Dynamic Economic Dispatch problem, demonstrating a considerable reduction in the prevalent heuristic algorithm's optimal generation cost and in the maximization of economic profit.

Balance-Swap Optimization of Economic Load Dispatch Problem using Quadratic Fuel Cost Function (이차 발전비용함수를 사용한 경제급전문제의 균형-교환 최적화)

  • Lee, Sang-Un
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.14 no.4
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    • pp.243-250
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    • 2014
  • In this paper, I devise a balance-swap optimization (BSO) algorithm to solve economic load dispatch with a quadratic fuel cost function. This algorithm firstly sets initial values to $P_i{\leftarrow}P_i^{max}$, (${\Sigma}P_i^{max}$ > $P_d$) and subsequently entails two major processes: a balance process whereby a generator's power i of $_{max}\{F(P_i)-F(P_i-{\alpha})\}$, ${\alpha}=_{min}(P_i-P_i^{min})$ is balanced by $P_i{\leftarrow}P_i-{\alpha}$ until ${\Sigma}P_i=P_d$; and a swap process whereby $_{max}\{F(P_i)-F(P_i-{\beta})\}$ > $_{min}\{F(P_i+{{\beta})-F(P_j)\}$, $i{\neq}j$, ${\beta}$ = 1.0, 0.1, 0.1, 0.01, 0.001 is set at $P_i{\leftarrow}P_i-{\beta}$, $P_j{\leftarrow}P_j+{\beta}$. When applied to 15, 20, and 38-generators benchmark data, this simple algorithm has proven to consistently yield the best possible results. Moreover, this algorithm has dramatically reduced the costs for a centralized operation of 73-generators - a sum of the three benchmark cases - which could otherwise have been impossible for independent operations.