• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.50 no.1
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• pp.13-20
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• 2022

Aircraft weight is an important factor affecting performance and fuel efficiency. In the conceptual design stage of the aircraft, the process of balancing cost and weight is performed using empirical formulas such as fuel consumption cost per weight in estimating element weight. In addition, when an airline operates an aircraft, it promotes fuel efficiency improvement, fuel saving and carbon reduction through weight management activities. The relationship between changes in aircraft weight and changes in fuel consumption is called the cost of weight, and the cost of weight is used to evaluate the effect of adding or reducing weight to an aircraft on fuel consumption. In this study, the problems of the existing cost of weight calculation method are identified, and a new cost of weight calculation method is introduced to solve the problem. Using Breguet's Range Formula and actual flight data of the A350-900 aircraft, two weight costs are calculated based on take-off weight and landing weight. In conclusion, it was suggested that it is reasonable to use the cost of weight based on the take-off weight and the landing weight for other purposes. In particular, the cost of weight based on the landing weight can be used as an empirical formula for estimating element weight and optimizing cost and weight in the conceptual design stage of similar aircraft.

• Herbal Formula Science
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• v.15 no.1
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• pp.137-144
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• 2007

Background and Objectives : There are three kinds of formulas for purging the spleen to cure its sthenic syndrome based on the types of preparation formulas : Sabeetang, Sabeehwan, Sabeesan and Sabeeeum. Another formulas called Sahwangtang, Sahwangsan. Sahwangeum is to purge the yellow colour of spleen. There are 8 kinds of Sabeetang, 3 kinds of Sabeehwan, 3 kinds of Sabeesan, 1 kind of Sabeeeum, 4 kinds of Sahwangtang, 7 kinds of Sahwangsan, and 1 kind of Sahwangeum. Combination of herbal medicines, carried out in formulas for purging the spleen, consists of various kinds depending on medical scientists' personal experience in medical treatment without any general principles, which makes it difficult to apply it to clinical use. The objectives of this study lie in theoretical establishment of Sabeetang for curing the sthenic syndrome of spleen through analyzing the component medicines and combination principles of Hyeongok's Sabeetang, and furthermore, maximizing the clinical use of Sabeetang. Methods : This study analyzed the component medicines and combination principles of Hyeongok's Sabeetang based on the theory for properties and tastes of herbal medicines from the ${\ulcorner}$Yellow Emperor's Canon of Internal Medicine${\lrcorner}$ , the theory for principal herbal medicine, assistant herbal medicine, adjuvant herbal medicine, dispatcher herbal medicine, and the five elements doctrine. Hyeongok's Sabeetang is an odd prescription, composed of 7 kinds of ingredients : No.1 Rhizoma Coptidis (2don;7.5g), No.2 Fructus Gardeniae (1don;3.75g), No.3 Ramulus Cinnamomi (1don), No.4 Gypsum Fibrosum (1don), No.5 Fructus Aurantii Immaturus (1don), No.6 Cortex Magnoliae Omcinalis (1don), and No.7 Radix Et Rhizoma Rhei (1don) Results : There are three methods for curing the sthenic syndrome of spleen according to the five elements doctrine : purging the spleen, purging the lung and invigorating the liver. First, if you suffer from the sthenic syndrome of the spleen, you need to purge your spleen. There are two available methods, including taste and property purgation according to the theory for properties and tastes of herbal medicines. They each imply the bitter taste and the cool property purge the spleen. In the case of taste purgation, two herbal medicines with bitter taste. Rhizoma Coptidis and Fructus Gardeniae, are combined into the principal and assistant herbal medicine, respectively. For property purgation, three herbal medicines with the cool property, Gypsum Fibrosum, Fructus Aurantii Immaturus and Radix Et Rhizoma Rhei, are combined into adjuvant herbal medicines. Secondly, if you suffer from the sthenic syndrome of the spleen, you need to purge your lung which is child in the mother-child relationship in inter-promotion among the five elements. There are two methods to purge the lung, including taste and property purgation according to the theory for properties and tastes of herbal medicines. They each mean the pungent taste and the warm property purge the lung. Therefore, it is important to use pungent herbal medicines for taste purgation and warm ones for property purgation. Both pungent and warm herb and property invigoration to invigorate the liver with warm property. Therefore, it is important to use pungent herbal medicines for taste invigoration and warm ones for property invigoration. Both pungent and warm herbal medicines, Ramulus Cinnamomi and Cortex Magnoliae Officinalis, were combined to invigorate the liver and purge the lung. In addition, Gypsum Fibrosum are combined as dispatcher herbal medicine, leading all the herbal medicines composing the formula to the spleen. Conclusions : First, to cure the sthenic syndrome of the spleen, the methods of purging the spleen and the lung, and invigorating the liver should be used according to the five elements doctrine. Secondly, herbal medicines appropriate for those treatment methods should be chosen according to the theory for properties and tastes of herbal medicine and thirdly, the combination of those herbal medicines should be carried out according to the theory for principal herbal medicine, assistant herbal medicine, adjuvant herbal medicine, dispatcher herbal medicine. As a good example, Hyeongok's Sabeetang is combined according to the above theories. In conclusion, this formula was created by applying to the theory for properties and tastes of herbal medicines.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.37 no.2
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• pp.303-310
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• 2017

Evapotranspiration is a significant hydrologic quantity for understanding the amount of available water resource evaluation, water balance analysis, water circulation and energy circulation. Various methods have been developed for estimating the evapotranspiration using data observed at meteorological observatories. Especially, the focus of methods has been on the complementary relationship that the actual evapotranspiration is equal to the difference between the twice of evapotranspiration in the wet condition and the potential evapotranspiration. The Granger and Gary (GG) method is an empirical formula that can be used to estimate the evapotranspiration using only empirical parameters based on the complementary relationship and using only the net radiation and temperature of the region. In this study, we compared the evapotranspiration data observed at 10 sites in Asia within the dataset of FLUXNET2015, with the evapotranspiration calculated by GG method. The evapotranspiration in inland area was estimated more accurately than that of coastal area. Simulated Annealing (SA) was used for the coastal area to modify the parameters. Using the modified GG method, we could improve the statistics such as root mean square error, the coefficient of determination ($R^2$), and the mean absolute ${\mid}BIAS{\mid}$ of the evapotranspiration estimation in coastal area.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.48 no.1
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• pp.51-58
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• 2012

As a basic study to improve hooking ability of long line fishing gear, which is widely used around Jeju-do coast, the researcher performed hooking experiment of parrot fish by manufacturing and installing 7 kinds of model long line fishing gears, whose thickness of branch line are different and 8 kinds of model long line fishing gear, whose length of branch line are different, in indoor circular aquarium, which is installed for the model experiment of thickness and length of branch line that are various by fishing implement and improper. The hooking rate depending on thickness and length of branch line was calculated and the effect of thickness and length of branch line on hooking rate was analyzed. Its results are as follows. When branch line was thin and long, high hooking rate appeared. In the scope of value setting, the relationship between thickness ($B_t$) of branch line and total hooking rate ($Th_r$) can be shown as following formula as. In the scope of value setting, the relationship between length ($B_t$) of branch line and total hooking rate ($B_t$) can be shown as $Th_r=-20.83B_t+26.04$. Through Pearson correlation analysis, the coefficient of correlation between thickness of branch line and hooking rate was -0.718. Therefore it showed significance in 0.01 significance level. Through Pearson correlation analysis, the coefficient of correlation between length of branch line and hooking rate was 0.431. Therefore it showed significance in 0.01 significance level.

• Journal of Korean Medical classics
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• v.30 no.1
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• pp.87-110
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• 2017

Objectives : The purpose of this paper is to study the form, contents and special features found in Qianhuang's life, books, his relationship with his disciples and Shanghansuyuanji's edition and its pass-ons. Methods : The best version among Shanghansuyuanji's copies was selected. Based on this, Qianhuang's life, books and his relationship with his disciples were studied, and Shanghansuyuanji's edition and its pass-ons, form and contents were analyzed. Results & Conclusions: Through study, first I see that Qianhuang was born in the early period of Qing Dynasty and died after the publication of Shanghansuyuanji, Suwen's annotation book probably had not been published yet, his mentor were Fangyouzhi and Yujiayan. Second, I see that he organized Shanghanlun sentences from his own perspective of cause of a disease and cure method. Third, I see that he viewed the diseases of six meridians with the perspective of yinyang and explained the concept of three yins and three yangs in relation to yinyang's ups and downs, and his Yuggyeongjasu theory made possible various interpretations of disease mechanism. Fourth, I see that he held critical views towards the Shanghanlun sentences through the Error Discrimination. Fifth, I see that he viewed disease mechaniam in interdependent relationships or from the point of view of the School of Warming and Tonifying through the Meaning of Herbal Formula. Sixth, I see that he sometimes quoted Neijing in proper ways that fit the disease mechanism in Shanghanlun. On the other hand, he quoted Neijing solely for the reason that identical words are used, but some of these were not proper. Additionally, he criticized the aforementioned annotators for improper quoting Neijing. Consequentially, for reasons mentioned above Qianhuang's Shanghansuyuanji has great importance as a Shanghanlun annotation book.

• Journal of Korea Water Resources Association
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• v.43 no.6
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• pp.525-531
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• 2010

In this study, the effects of upstream Froude number ($Fr_1$), weir height (h), weir length (L), weir width (W) and main channel width (B) on the discharge coefficient of broad crested side-weirs in a relatively wide rectangular open channel were investigated experimentally. Furthermore the relationship between discharge coefficients of sharp crested side weir and broad crested side weir was studied using the concept of De Marchi discharge coefficient. The effect of $Fr_1$ on the relationship between discharge coefficients of sharp crested side weir and broad crested side weir is decreased in wide open channel and the relative importance of other influential parameters like h/$y_1$, L/B, and W/($y_1-h$) are increased. New estimated equations for the discharge coefficients of broad crested side weir are suggested from regression analysis with the experiment data sets.

• Journal of the East Asian Society of Dietary Life
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• v.4 no.3
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• pp.21-30
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• 1994

The relationship between bone mineral density and the environmental factors were investigated from the view point of preventing osteoporosis in Korean pubescent girls. The effects of calcium, nutrient intake, physical activity on total bone mineral density, lumbar spine and femoral bone mineral density and total bone mineral content were evaluated 33 healthy pubescent girls aged 14∼16y. A convenient method was used to assess nutritional and energy intake and calcium index was used together. Calcium intake in childhood was estimated by asking whether subjects usually drank milk as children. Eating habits data and history of menstruation were obtained by questionnaire and interview. Average energy expenditure was calculated. Bone mineral density and content were measured by dual energy x-ray absorptiometry using a Lunar DPX＋Scanner (Lunar, Madison, WI). The lumbar spine(L2∼L4) and three sites in the proximal femur (femoral neck, trochanteric region, and Ward's triangle)were measured. Height and weight were measured, and the body mass index(BMI) was derived from the formula : BMI=kg/㎡ Statistical analysis was performed by simple correlation using the SAS package. The mean calcium intake (736mg) was below the RDA of 800mg/d. Twelve percent of the total subjects did not drink milk at all because they did not like the taste. Skipping meals, low calcium intake and low energy intake were significantly correlated with the low BMD. Also the data indicate that girls who reported drinking milk with every meal during childhood had significantly higher bone densities than girls who reported drinking milk less frequently. The results suggest that milk consumption in childhood appears to be needed not only for growth and development, but possibly also to assure an optimal peak of bone mass and thus greater latitude for the maintenance or skeletal integrity in the face of bone losses. There was a highly significant correlation between the total BMD and overall level of physical activity. Body weight was a better predictor of total BMD than was and other factor. Simple mechanical loading may explain why body weight, but total BMC was positively relatd to height. Conclusively, increasing calcium intake and physical activity in the pubescent girls could influence BMD.

• Journal of the Korean Geotechnical Society
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• v.20 no.6
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• pp.109-118
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• 2004

The consolidation of clay occurs with time lag, and this kind of lag can be separated into plastic lag and hydraulic lag. In this study, CRS tests were performed to research the effect of original secondary consolidation of the clay with respect to the characteristics of consolidation. Test results showed that plastic time lag was one of the key factors to get the preconsolidation pressure, and suggested the formula of the Quasi-preconsolidation pressure obtained from the relationship between consolidation time lag and consolidation pressures. In addition though the characteristics of coefficient of consolidation show a wide range of values, after passing the double preconsolidation point, it showed the tendency to converge into the constant value. The coefficient of permeability in normally consolidated state is related to its void ratio, and the permeability variables, n and $C_1$ were determined by the test results using the equation suggested by Samarasinghe. et. al. And then the equation was compared with the Kozeny-Carman's equation. Because of delayed compression caused by consolidation time lag, aging effect could be also found in the relationship between coefficient of permeability and void ratio.

• Transactions of the Korean Society of Mechanical Engineers
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• v.10 no.6
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• pp.916-922
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• 1986

This paper presents the preliminary results of an experimental study on surface crack growth under fatigue loadings. The objective of this paper is to assess the effect of the initial crack size on crack propagation behaviors. Transparent PMMA plate speciments with shallow circular arc notch were used. Crack growth behaviors were observed and measured in two directions by travelling microscopes. The fatigue crack initiated at the deepest part on the initial arc shaped notch and then propagated to depth direction as well as spreading gradually along the notch tip. A considerable number of cycles was needed until the depth crack spreaded to the surface notch tip. When the fatigue crack reached the surface notch tip the crack front became an approximate semi-ellipse, primary semi-elliptical crack. Test results suggest that the relationships between fatigue crack growth rate and stress intensity factor range in both directions can be expressed by power law (Paris) and that relationship in width direction depends upon the crack ratios a$_{1}$/b$_{1}$, of the primary semi-elliptical crack. The relationship between the nondimensional crack lengths in both directions can be represented as the formula: (a/t)$^{n}$ =B(2b/W+A) where n and A are constants and B is seems to be depended upon the crack ratio a$_{1}$/b$_{1}$.

• Journal of the Korean institute of surface engineering
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• v.51 no.3
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• pp.157-163
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• 2018

The anodic $TiO_2$ layers which are prepared in various anodization conditions exhibit their specific color depending on the thickness of $TiO_2$. In this study, the relationship between the color of $TiO_2$ layer, which is grown by PEO (Plasma electrolytic oxidation), and the thickness of the $TiO_2$ layer is investigated. To evaluate the color change of the $TiO_2$ layer, the value of color ($dE^*ab$) is measured and calculated by spectrophotometer and chromameter. As a result, it is found that $dE^*ab$ values and thickness of $TiO_2$ layers form a linear relationship with meaningful formular. This formula can be helpful to quantify the thickness of the $TiO_2$ layer by the numerical $dE^*ab$ values. In this process, the spectrophotometer shows more precise results than the chromameter dose. If fluoride ions ($F^-$) are included in the electrolyte, it will affect the $dE^*ab$ values of the $TiO_2$. layer. This is against the propensity, which is analyzed by XRD (X-ray diffraction) and XPS (X-ray photoelectron spectroscopy). It is important that the formular suggested in this study provides other metals which can be also anodized with the possibility of quantifying the thickness of the $TiO_2$ layer by the $dE^*ab$ values.